Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

12 files changed, 10041 insertions, 0 deletions

diff --git a/kernel/drivers/media/usb/uvc/Kconfig b/kernel/drivers/media/usb/uvc/Kconfig
new file mode 100644
index 000000000..6ed85efab
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/Kconfig
@@ -0,0 +1,20 @@
+config USB_VIDEO_CLASS
+	tristate "USB Video Class (UVC)"
+	depends on VIDEO_V4L2
+	select VIDEOBUF2_VMALLOC
+	---help---
+	  Support for the USB Video Class (UVC).  Currently only video
+	  input devices, such as webcams, are supported.
+
+	  For more information see: <http://linux-uvc.berlios.de/>
+
+config USB_VIDEO_CLASS_INPUT_EVDEV
+	bool "UVC input events device support"
+	default y
+	depends on USB_VIDEO_CLASS
+	depends on USB_VIDEO_CLASS=INPUT || INPUT=y
+	---help---
+	  This option makes USB Video Class devices register an input device
+	  to report button events.
+
+	  If you are in doubt, say Y.
diff --git a/kernel/drivers/media/usb/uvc/Makefile b/kernel/drivers/media/usb/uvc/Makefile
new file mode 100644
index 000000000..c26d12fdb
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/Makefile
@@ -0,0 +1,6 @@
+uvcvideo-objs  := uvc_driver.o uvc_queue.o uvc_v4l2.o uvc_video.o uvc_ctrl.o \
+		  uvc_status.o uvc_isight.o uvc_debugfs.o
+ifeq ($(CONFIG_MEDIA_CONTROLLER),y)
+uvcvideo-objs  += uvc_entity.o
+endif
+obj-$(CONFIG_USB_VIDEO_CLASS) += uvcvideo.o
diff --git a/kernel/drivers/media/usb/uvc/uvc_ctrl.c b/kernel/drivers/media/usb/uvc/uvc_ctrl.c
new file mode 100644
index 000000000..3e59b288b
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_ctrl.c
@@ -0,0 +1,2223 @@
+/*
+ *      uvc_ctrl.c  --  USB Video Class driver - Controls
+ *
+ *      Copyright (C) 2005-2010
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <linux/atomic.h>
+#include <media/v4l2-ctrls.h>
+
+#include "uvcvideo.h"
+
+#define UVC_CTRL_DATA_CURRENT	0
+#define UVC_CTRL_DATA_BACKUP	1
+#define UVC_CTRL_DATA_MIN	2
+#define UVC_CTRL_DATA_MAX	3
+#define UVC_CTRL_DATA_RES	4
+#define UVC_CTRL_DATA_DEF	5
+#define UVC_CTRL_DATA_LAST	6
+
+/* ------------------------------------------------------------------------
+ * Controls
+ */
+
+static struct uvc_control_info uvc_ctrls[] = {
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_BRIGHTNESS_CONTROL,
+		.index		= 0,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_CONTRAST_CONTROL,
+		.index		= 1,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_HUE_CONTROL,
+		.index		= 2,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_SATURATION_CONTROL,
+		.index		= 3,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_SHARPNESS_CONTROL,
+		.index		= 4,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_GAMMA_CONTROL,
+		.index		= 5,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_WHITE_BALANCE_TEMPERATURE_CONTROL,
+		.index		= 6,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_CONTROL,
+		.index		= 7,
+		.size		= 4,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_BACKLIGHT_COMPENSATION_CONTROL,
+		.index		= 8,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_GAIN_CONTROL,
+		.index		= 9,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
+		.index		= 10,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
+				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_HUE_AUTO_CONTROL,
+		.index		= 11,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
+				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_WHITE_BALANCE_TEMPERATURE_AUTO_CONTROL,
+		.index		= 12,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
+				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_AUTO_CONTROL,
+		.index		= 13,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
+				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_DIGITAL_MULTIPLIER_CONTROL,
+		.index		= 14,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_DIGITAL_MULTIPLIER_LIMIT_CONTROL,
+		.index		= 15,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_ANALOG_VIDEO_STANDARD_CONTROL,
+		.index		= 16,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_GET_CUR,
+	},
+	{
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_ANALOG_LOCK_STATUS_CONTROL,
+		.index		= 17,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_GET_CUR,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_SCANNING_MODE_CONTROL,
+		.index		= 0,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_AE_MODE_CONTROL,
+		.index		= 1,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
+				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_GET_RES
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_AE_PRIORITY_CONTROL,
+		.index		= 2,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_EXPOSURE_TIME_ABSOLUTE_CONTROL,
+		.index		= 3,
+		.size		= 4,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_EXPOSURE_TIME_RELATIVE_CONTROL,
+		.index		= 4,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_FOCUS_ABSOLUTE_CONTROL,
+		.index		= 5,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_FOCUS_RELATIVE_CONTROL,
+		.index		= 6,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_MIN
+				| UVC_CTRL_FLAG_GET_MAX | UVC_CTRL_FLAG_GET_RES
+				| UVC_CTRL_FLAG_GET_DEF
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_IRIS_ABSOLUTE_CONTROL,
+		.index		= 7,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_IRIS_RELATIVE_CONTROL,
+		.index		= 8,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_ZOOM_ABSOLUTE_CONTROL,
+		.index		= 9,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_ZOOM_RELATIVE_CONTROL,
+		.index		= 10,
+		.size		= 3,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_MIN
+				| UVC_CTRL_FLAG_GET_MAX | UVC_CTRL_FLAG_GET_RES
+				| UVC_CTRL_FLAG_GET_DEF
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_PANTILT_ABSOLUTE_CONTROL,
+		.index		= 11,
+		.size		= 8,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_PANTILT_RELATIVE_CONTROL,
+		.index		= 12,
+		.size		= 4,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_ROLL_ABSOLUTE_CONTROL,
+		.index		= 13,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR
+				| UVC_CTRL_FLAG_GET_RANGE
+				| UVC_CTRL_FLAG_RESTORE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_ROLL_RELATIVE_CONTROL,
+		.index		= 14,
+		.size		= 2,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_MIN
+				| UVC_CTRL_FLAG_GET_MAX | UVC_CTRL_FLAG_GET_RES
+				| UVC_CTRL_FLAG_GET_DEF
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_FOCUS_AUTO_CONTROL,
+		.index		= 17,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
+				| UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_RESTORE,
+	},
+	{
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_PRIVACY_CONTROL,
+		.index		= 18,
+		.size		= 1,
+		.flags		= UVC_CTRL_FLAG_SET_CUR | UVC_CTRL_FLAG_GET_CUR
+				| UVC_CTRL_FLAG_RESTORE
+				| UVC_CTRL_FLAG_AUTO_UPDATE,
+	},
+};
+
+static struct uvc_menu_info power_line_frequency_controls[] = {
+	{ 0, "Disabled" },
+	{ 1, "50 Hz" },
+	{ 2, "60 Hz" },
+};
+
+static struct uvc_menu_info exposure_auto_controls[] = {
+	{ 2, "Auto Mode" },
+	{ 1, "Manual Mode" },
+	{ 4, "Shutter Priority Mode" },
+	{ 8, "Aperture Priority Mode" },
+};
+
+static __s32 uvc_ctrl_get_zoom(struct uvc_control_mapping *mapping,
+	__u8 query, const __u8 *data)
+{
+	__s8 zoom = (__s8)data[0];
+
+	switch (query) {
+	case UVC_GET_CUR:
+		return (zoom == 0) ? 0 : (zoom > 0 ? data[2] : -data[2]);
+
+	case UVC_GET_MIN:
+	case UVC_GET_MAX:
+	case UVC_GET_RES:
+	case UVC_GET_DEF:
+	default:
+		return data[2];
+	}
+}
+
+static void uvc_ctrl_set_zoom(struct uvc_control_mapping *mapping,
+	__s32 value, __u8 *data)
+{
+	data[0] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
+	data[2] = min((int)abs(value), 0xff);
+}
+
+static __s32 uvc_ctrl_get_rel_speed(struct uvc_control_mapping *mapping,
+	__u8 query, const __u8 *data)
+{
+	unsigned int first = mapping->offset / 8;
+	__s8 rel = (__s8)data[first];
+
+	switch (query) {
+	case UVC_GET_CUR:
+		return (rel == 0) ? 0 : (rel > 0 ? data[first+1]
+						 : -data[first+1]);
+	case UVC_GET_MIN:
+		return -data[first+1];
+	case UVC_GET_MAX:
+	case UVC_GET_RES:
+	case UVC_GET_DEF:
+	default:
+		return data[first+1];
+	}
+}
+
+static void uvc_ctrl_set_rel_speed(struct uvc_control_mapping *mapping,
+	__s32 value, __u8 *data)
+{
+	unsigned int first = mapping->offset / 8;
+
+	data[first] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
+	data[first+1] = min_t(int, abs(value), 0xff);
+}
+
+static struct uvc_control_mapping uvc_ctrl_mappings[] = {
+	{
+		.id		= V4L2_CID_BRIGHTNESS,
+		.name		= "Brightness",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_BRIGHTNESS_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+	},
+	{
+		.id		= V4L2_CID_CONTRAST,
+		.name		= "Contrast",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_CONTRAST_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+	},
+	{
+		.id		= V4L2_CID_HUE,
+		.name		= "Hue",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_HUE_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+		.master_id	= V4L2_CID_HUE_AUTO,
+		.master_manual	= 0,
+	},
+	{
+		.id		= V4L2_CID_SATURATION,
+		.name		= "Saturation",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_SATURATION_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+	},
+	{
+		.id		= V4L2_CID_SHARPNESS,
+		.name		= "Sharpness",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_SHARPNESS_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+	},
+	{
+		.id		= V4L2_CID_GAMMA,
+		.name		= "Gamma",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_GAMMA_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+	},
+	{
+		.id		= V4L2_CID_BACKLIGHT_COMPENSATION,
+		.name		= "Backlight Compensation",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_BACKLIGHT_COMPENSATION_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+	},
+	{
+		.id		= V4L2_CID_GAIN,
+		.name		= "Gain",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_GAIN_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+	},
+	{
+		.id		= V4L2_CID_POWER_LINE_FREQUENCY,
+		.name		= "Power Line Frequency",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_POWER_LINE_FREQUENCY_CONTROL,
+		.size		= 2,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_MENU,
+		.data_type	= UVC_CTRL_DATA_TYPE_ENUM,
+		.menu_info	= power_line_frequency_controls,
+		.menu_count	= ARRAY_SIZE(power_line_frequency_controls),
+	},
+	{
+		.id		= V4L2_CID_HUE_AUTO,
+		.name		= "Hue, Auto",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_HUE_AUTO_CONTROL,
+		.size		= 1,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
+		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
+		.slave_ids	= { V4L2_CID_HUE, },
+	},
+	{
+		.id		= V4L2_CID_EXPOSURE_AUTO,
+		.name		= "Exposure, Auto",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_AE_MODE_CONTROL,
+		.size		= 4,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_MENU,
+		.data_type	= UVC_CTRL_DATA_TYPE_BITMASK,
+		.menu_info	= exposure_auto_controls,
+		.menu_count	= ARRAY_SIZE(exposure_auto_controls),
+		.slave_ids	= { V4L2_CID_EXPOSURE_ABSOLUTE, },
+	},
+	{
+		.id		= V4L2_CID_EXPOSURE_AUTO_PRIORITY,
+		.name		= "Exposure, Auto Priority",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_AE_PRIORITY_CONTROL,
+		.size		= 1,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
+		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
+	},
+	{
+		.id		= V4L2_CID_EXPOSURE_ABSOLUTE,
+		.name		= "Exposure (Absolute)",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_EXPOSURE_TIME_ABSOLUTE_CONTROL,
+		.size		= 32,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+		.master_id	= V4L2_CID_EXPOSURE_AUTO,
+		.master_manual	= V4L2_EXPOSURE_MANUAL,
+	},
+	{
+		.id		= V4L2_CID_AUTO_WHITE_BALANCE,
+		.name		= "White Balance Temperature, Auto",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_WHITE_BALANCE_TEMPERATURE_AUTO_CONTROL,
+		.size		= 1,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
+		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
+		.slave_ids	= { V4L2_CID_WHITE_BALANCE_TEMPERATURE, },
+	},
+	{
+		.id		= V4L2_CID_WHITE_BALANCE_TEMPERATURE,
+		.name		= "White Balance Temperature",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_WHITE_BALANCE_TEMPERATURE_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+		.master_id	= V4L2_CID_AUTO_WHITE_BALANCE,
+		.master_manual	= 0,
+	},
+	{
+		.id		= V4L2_CID_AUTO_WHITE_BALANCE,
+		.name		= "White Balance Component, Auto",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_AUTO_CONTROL,
+		.size		= 1,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
+		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
+		.slave_ids	= { V4L2_CID_BLUE_BALANCE,
+				    V4L2_CID_RED_BALANCE },
+	},
+	{
+		.id		= V4L2_CID_BLUE_BALANCE,
+		.name		= "White Balance Blue Component",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+		.master_id	= V4L2_CID_AUTO_WHITE_BALANCE,
+		.master_manual	= 0,
+	},
+	{
+		.id		= V4L2_CID_RED_BALANCE,
+		.name		= "White Balance Red Component",
+		.entity		= UVC_GUID_UVC_PROCESSING,
+		.selector	= UVC_PU_WHITE_BALANCE_COMPONENT_CONTROL,
+		.size		= 16,
+		.offset		= 16,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+		.master_id	= V4L2_CID_AUTO_WHITE_BALANCE,
+		.master_manual	= 0,
+	},
+	{
+		.id		= V4L2_CID_FOCUS_ABSOLUTE,
+		.name		= "Focus (absolute)",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_FOCUS_ABSOLUTE_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+		.master_id	= V4L2_CID_FOCUS_AUTO,
+		.master_manual	= 0,
+	},
+	{
+		.id		= V4L2_CID_FOCUS_AUTO,
+		.name		= "Focus, Auto",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_FOCUS_AUTO_CONTROL,
+		.size		= 1,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
+		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
+		.slave_ids	= { V4L2_CID_FOCUS_ABSOLUTE, },
+	},
+	{
+		.id		= V4L2_CID_IRIS_ABSOLUTE,
+		.name		= "Iris, Absolute",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_IRIS_ABSOLUTE_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+	},
+	{
+		.id		= V4L2_CID_IRIS_RELATIVE,
+		.name		= "Iris, Relative",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_IRIS_RELATIVE_CONTROL,
+		.size		= 8,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+	},
+	{
+		.id		= V4L2_CID_ZOOM_ABSOLUTE,
+		.name		= "Zoom, Absolute",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_ZOOM_ABSOLUTE_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+	},
+	{
+		.id		= V4L2_CID_ZOOM_CONTINUOUS,
+		.name		= "Zoom, Continuous",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_ZOOM_RELATIVE_CONTROL,
+		.size		= 0,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+		.get		= uvc_ctrl_get_zoom,
+		.set		= uvc_ctrl_set_zoom,
+	},
+	{
+		.id		= V4L2_CID_PAN_ABSOLUTE,
+		.name		= "Pan (Absolute)",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_PANTILT_ABSOLUTE_CONTROL,
+		.size		= 32,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+	},
+	{
+		.id		= V4L2_CID_TILT_ABSOLUTE,
+		.name		= "Tilt (Absolute)",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_PANTILT_ABSOLUTE_CONTROL,
+		.size		= 32,
+		.offset		= 32,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+	},
+	{
+		.id		= V4L2_CID_PAN_SPEED,
+		.name		= "Pan (Speed)",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_PANTILT_RELATIVE_CONTROL,
+		.size		= 16,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+		.get		= uvc_ctrl_get_rel_speed,
+		.set		= uvc_ctrl_set_rel_speed,
+	},
+	{
+		.id		= V4L2_CID_TILT_SPEED,
+		.name		= "Tilt (Speed)",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_PANTILT_RELATIVE_CONTROL,
+		.size		= 16,
+		.offset		= 16,
+		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
+		.get		= uvc_ctrl_get_rel_speed,
+		.set		= uvc_ctrl_set_rel_speed,
+	},
+	{
+		.id		= V4L2_CID_PRIVACY,
+		.name		= "Privacy",
+		.entity		= UVC_GUID_UVC_CAMERA,
+		.selector	= UVC_CT_PRIVACY_CONTROL,
+		.size		= 1,
+		.offset		= 0,
+		.v4l2_type	= V4L2_CTRL_TYPE_BOOLEAN,
+		.data_type	= UVC_CTRL_DATA_TYPE_BOOLEAN,
+	},
+};
+
+/* ------------------------------------------------------------------------
+ * Utility functions
+ */
+
+static inline __u8 *uvc_ctrl_data(struct uvc_control *ctrl, int id)
+{
+	return ctrl->uvc_data + id * ctrl->info.size;
+}
+
+static inline int uvc_test_bit(const __u8 *data, int bit)
+{
+	return (data[bit >> 3] >> (bit & 7)) & 1;
+}
+
+static inline void uvc_clear_bit(__u8 *data, int bit)
+{
+	data[bit >> 3] &= ~(1 << (bit & 7));
+}
+
+/* Extract the bit string specified by mapping->offset and mapping->size
+ * from the little-endian data stored at 'data' and return the result as
+ * a signed 32bit integer. Sign extension will be performed if the mapping
+ * references a signed data type.
+ */
+static __s32 uvc_get_le_value(struct uvc_control_mapping *mapping,
+	__u8 query, const __u8 *data)
+{
+	int bits = mapping->size;
+	int offset = mapping->offset;
+	__s32 value = 0;
+	__u8 mask;
+
+	data += offset / 8;
+	offset &= 7;
+	mask = ((1LL << bits) - 1) << offset;
+
+	for (; bits > 0; data++) {
+		__u8 byte = *data & mask;
+		value |= offset > 0 ? (byte >> offset) : (byte << (-offset));
+		bits -= 8 - (offset > 0 ? offset : 0);
+		offset -= 8;
+		mask = (1 << bits) - 1;
+	}
+
+	/* Sign-extend the value if needed. */
+	if (mapping->data_type == UVC_CTRL_DATA_TYPE_SIGNED)
+		value |= -(value & (1 << (mapping->size - 1)));
+
+	return value;
+}
+
+/* Set the bit string specified by mapping->offset and mapping->size
+ * in the little-endian data stored at 'data' to the value 'value'.
+ */
+static void uvc_set_le_value(struct uvc_control_mapping *mapping,
+	__s32 value, __u8 *data)
+{
+	int bits = mapping->size;
+	int offset = mapping->offset;
+	__u8 mask;
+
+	/* According to the v4l2 spec, writing any value to a button control
+	 * should result in the action belonging to the button control being
+	 * triggered. UVC devices however want to see a 1 written -> override
+	 * value.
+	 */
+	if (mapping->v4l2_type == V4L2_CTRL_TYPE_BUTTON)
+		value = -1;
+
+	data += offset / 8;
+	offset &= 7;
+
+	for (; bits > 0; data++) {
+		mask = ((1LL << bits) - 1) << offset;
+		*data = (*data & ~mask) | ((value << offset) & mask);
+		value >>= offset ? offset : 8;
+		bits -= 8 - offset;
+		offset = 0;
+	}
+}
+
+/* ------------------------------------------------------------------------
+ * Terminal and unit management
+ */
+
+static const __u8 uvc_processing_guid[16] = UVC_GUID_UVC_PROCESSING;
+static const __u8 uvc_camera_guid[16] = UVC_GUID_UVC_CAMERA;
+static const __u8 uvc_media_transport_input_guid[16] =
+	UVC_GUID_UVC_MEDIA_TRANSPORT_INPUT;
+
+static int uvc_entity_match_guid(const struct uvc_entity *entity,
+	const __u8 guid[16])
+{
+	switch (UVC_ENTITY_TYPE(entity)) {
+	case UVC_ITT_CAMERA:
+		return memcmp(uvc_camera_guid, guid, 16) == 0;
+
+	case UVC_ITT_MEDIA_TRANSPORT_INPUT:
+		return memcmp(uvc_media_transport_input_guid, guid, 16) == 0;
+
+	case UVC_VC_PROCESSING_UNIT:
+		return memcmp(uvc_processing_guid, guid, 16) == 0;
+
+	case UVC_VC_EXTENSION_UNIT:
+		return memcmp(entity->extension.guidExtensionCode,
+			      guid, 16) == 0;
+
+	default:
+		return 0;
+	}
+}
+
+/* ------------------------------------------------------------------------
+ * UVC Controls
+ */
+
+static void __uvc_find_control(struct uvc_entity *entity, __u32 v4l2_id,
+	struct uvc_control_mapping **mapping, struct uvc_control **control,
+	int next)
+{
+	struct uvc_control *ctrl;
+	struct uvc_control_mapping *map;
+	unsigned int i;
+
+	if (entity == NULL)
+		return;
+
+	for (i = 0; i < entity->ncontrols; ++i) {
+		ctrl = &entity->controls[i];
+		if (!ctrl->initialized)
+			continue;
+
+		list_for_each_entry(map, &ctrl->info.mappings, list) {
+			if ((map->id == v4l2_id) && !next) {
+				*control = ctrl;
+				*mapping = map;
+				return;
+			}
+
+			if ((*mapping == NULL || (*mapping)->id > map->id) &&
+			    (map->id > v4l2_id) && next) {
+				*control = ctrl;
+				*mapping = map;
+			}
+		}
+	}
+}
+
+static struct uvc_control *uvc_find_control(struct uvc_video_chain *chain,
+	__u32 v4l2_id, struct uvc_control_mapping **mapping)
+{
+	struct uvc_control *ctrl = NULL;
+	struct uvc_entity *entity;
+	int next = v4l2_id & V4L2_CTRL_FLAG_NEXT_CTRL;
+
+	*mapping = NULL;
+
+	/* Mask the query flags. */
+	v4l2_id &= V4L2_CTRL_ID_MASK;
+
+	/* Find the control. */
+	list_for_each_entry(entity, &chain->entities, chain) {
+		__uvc_find_control(entity, v4l2_id, mapping, &ctrl, next);
+		if (ctrl && !next)
+			return ctrl;
+	}
+
+	if (ctrl == NULL && !next)
+		uvc_trace(UVC_TRACE_CONTROL, "Control 0x%08x not found.\n",
+				v4l2_id);
+
+	return ctrl;
+}
+
+static int uvc_ctrl_populate_cache(struct uvc_video_chain *chain,
+	struct uvc_control *ctrl)
+{
+	int ret;
+
+	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) {
+		ret = uvc_query_ctrl(chain->dev, UVC_GET_DEF, ctrl->entity->id,
+				     chain->dev->intfnum, ctrl->info.selector,
+				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF),
+				     ctrl->info.size);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN) {
+		ret = uvc_query_ctrl(chain->dev, UVC_GET_MIN, ctrl->entity->id,
+				     chain->dev->intfnum, ctrl->info.selector,
+				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN),
+				     ctrl->info.size);
+		if (ret < 0)
+			return ret;
+	}
+	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX) {
+		ret = uvc_query_ctrl(chain->dev, UVC_GET_MAX, ctrl->entity->id,
+				     chain->dev->intfnum, ctrl->info.selector,
+				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX),
+				     ctrl->info.size);
+		if (ret < 0)
+			return ret;
+	}
+	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES) {
+		ret = uvc_query_ctrl(chain->dev, UVC_GET_RES, ctrl->entity->id,
+				     chain->dev->intfnum, ctrl->info.selector,
+				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES),
+				     ctrl->info.size);
+		if (ret < 0) {
+			if (UVC_ENTITY_TYPE(ctrl->entity) !=
+			    UVC_VC_EXTENSION_UNIT)
+				return ret;
+
+			/* GET_RES is mandatory for XU controls, but some
+			 * cameras still choke on it. Ignore errors and set the
+			 * resolution value to zero.
+			 */
+			uvc_warn_once(chain->dev, UVC_WARN_XU_GET_RES,
+				      "UVC non compliance - GET_RES failed on "
+				      "an XU control. Enabling workaround.\n");
+			memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES), 0,
+			       ctrl->info.size);
+		}
+	}
+
+	ctrl->cached = 1;
+	return 0;
+}
+
+static int __uvc_ctrl_get(struct uvc_video_chain *chain,
+	struct uvc_control *ctrl, struct uvc_control_mapping *mapping,
+	s32 *value)
+{
+	struct uvc_menu_info *menu;
+	unsigned int i;
+	int ret;
+
+	if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0)
+		return -EACCES;
+
+	if (!ctrl->loaded) {
+		ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, ctrl->entity->id,
+				chain->dev->intfnum, ctrl->info.selector,
+				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+				ctrl->info.size);
+		if (ret < 0)
+			return ret;
+
+		ctrl->loaded = 1;
+	}
+
+	*value = mapping->get(mapping, UVC_GET_CUR,
+		uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
+
+	if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
+		menu = mapping->menu_info;
+		for (i = 0; i < mapping->menu_count; ++i, ++menu) {
+			if (menu->value == *value) {
+				*value = i;
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
+	struct uvc_control *ctrl,
+	struct uvc_control_mapping *mapping,
+	struct v4l2_queryctrl *v4l2_ctrl)
+{
+	struct uvc_control_mapping *master_map = NULL;
+	struct uvc_control *master_ctrl = NULL;
+	struct uvc_menu_info *menu;
+	unsigned int i;
+
+	memset(v4l2_ctrl, 0, sizeof *v4l2_ctrl);
+	v4l2_ctrl->id = mapping->id;
+	v4l2_ctrl->type = mapping->v4l2_type;
+	strlcpy(v4l2_ctrl->name, mapping->name, sizeof v4l2_ctrl->name);
+	v4l2_ctrl->flags = 0;
+
+	if (!(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR))
+		v4l2_ctrl->flags |= V4L2_CTRL_FLAG_WRITE_ONLY;
+	if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
+		v4l2_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
+	if (mapping->master_id)
+		__uvc_find_control(ctrl->entity, mapping->master_id,
+				   &master_map, &master_ctrl, 0);
+	if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) {
+		s32 val;
+		int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val);
+		if (ret < 0)
+			return ret;
+
+		if (val != mapping->master_manual)
+				v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
+	}
+
+	if (!ctrl->cached) {
+		int ret = uvc_ctrl_populate_cache(chain, ctrl);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_DEF) {
+		v4l2_ctrl->default_value = mapping->get(mapping, UVC_GET_DEF,
+				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_DEF));
+	}
+
+	switch (mapping->v4l2_type) {
+	case V4L2_CTRL_TYPE_MENU:
+		v4l2_ctrl->minimum = 0;
+		v4l2_ctrl->maximum = mapping->menu_count - 1;
+		v4l2_ctrl->step = 1;
+
+		menu = mapping->menu_info;
+		for (i = 0; i < mapping->menu_count; ++i, ++menu) {
+			if (menu->value == v4l2_ctrl->default_value) {
+				v4l2_ctrl->default_value = i;
+				break;
+			}
+		}
+
+		return 0;
+
+	case V4L2_CTRL_TYPE_BOOLEAN:
+		v4l2_ctrl->minimum = 0;
+		v4l2_ctrl->maximum = 1;
+		v4l2_ctrl->step = 1;
+		return 0;
+
+	case V4L2_CTRL_TYPE_BUTTON:
+		v4l2_ctrl->minimum = 0;
+		v4l2_ctrl->maximum = 0;
+		v4l2_ctrl->step = 0;
+		return 0;
+
+	default:
+		break;
+	}
+
+	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MIN)
+		v4l2_ctrl->minimum = mapping->get(mapping, UVC_GET_MIN,
+				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
+
+	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_MAX)
+		v4l2_ctrl->maximum = mapping->get(mapping, UVC_GET_MAX,
+				     uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
+
+	if (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES)
+		v4l2_ctrl->step = mapping->get(mapping, UVC_GET_RES,
+				  uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
+
+	return 0;
+}
+
+int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
+	struct v4l2_queryctrl *v4l2_ctrl)
+{
+	struct uvc_control *ctrl;
+	struct uvc_control_mapping *mapping;
+	int ret;
+
+	ret = mutex_lock_interruptible(&chain->ctrl_mutex);
+	if (ret < 0)
+		return -ERESTARTSYS;
+
+	ctrl = uvc_find_control(chain, v4l2_ctrl->id, &mapping);
+	if (ctrl == NULL) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	ret = __uvc_query_v4l2_ctrl(chain, ctrl, mapping, v4l2_ctrl);
+done:
+	mutex_unlock(&chain->ctrl_mutex);
+	return ret;
+}
+
+/*
+ * Mapping V4L2 controls to UVC controls can be straighforward if done well.
+ * Most of the UVC controls exist in V4L2, and can be mapped directly. Some
+ * must be grouped (for instance the Red Balance, Blue Balance and Do White
+ * Balance V4L2 controls use the White Balance Component UVC control) or
+ * otherwise translated. The approach we take here is to use a translation
+ * table for the controls that can be mapped directly, and handle the others
+ * manually.
+ */
+int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
+	struct v4l2_querymenu *query_menu)
+{
+	struct uvc_menu_info *menu_info;
+	struct uvc_control_mapping *mapping;
+	struct uvc_control *ctrl;
+	u32 index = query_menu->index;
+	u32 id = query_menu->id;
+	int ret;
+
+	memset(query_menu, 0, sizeof(*query_menu));
+	query_menu->id = id;
+	query_menu->index = index;
+
+	ret = mutex_lock_interruptible(&chain->ctrl_mutex);
+	if (ret < 0)
+		return -ERESTARTSYS;
+
+	ctrl = uvc_find_control(chain, query_menu->id, &mapping);
+	if (ctrl == NULL || mapping->v4l2_type != V4L2_CTRL_TYPE_MENU) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	if (query_menu->index >= mapping->menu_count) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	menu_info = &mapping->menu_info[query_menu->index];
+
+	if (mapping->data_type == UVC_CTRL_DATA_TYPE_BITMASK &&
+	    (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES)) {
+		s32 bitmap;
+
+		if (!ctrl->cached) {
+			ret = uvc_ctrl_populate_cache(chain, ctrl);
+			if (ret < 0)
+				goto done;
+		}
+
+		bitmap = mapping->get(mapping, UVC_GET_RES,
+				      uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
+		if (!(bitmap & menu_info->value)) {
+			ret = -EINVAL;
+			goto done;
+		}
+	}
+
+	strlcpy(query_menu->name, menu_info->name, sizeof query_menu->name);
+
+done:
+	mutex_unlock(&chain->ctrl_mutex);
+	return ret;
+}
+
+/* --------------------------------------------------------------------------
+ * Ctrl event handling
+ */
+
+static void uvc_ctrl_fill_event(struct uvc_video_chain *chain,
+	struct v4l2_event *ev,
+	struct uvc_control *ctrl,
+	struct uvc_control_mapping *mapping,
+	s32 value, u32 changes)
+{
+	struct v4l2_queryctrl v4l2_ctrl;
+
+	__uvc_query_v4l2_ctrl(chain, ctrl, mapping, &v4l2_ctrl);
+
+	memset(ev->reserved, 0, sizeof(ev->reserved));
+	ev->type = V4L2_EVENT_CTRL;
+	ev->id = v4l2_ctrl.id;
+	ev->u.ctrl.value = value;
+	ev->u.ctrl.changes = changes;
+	ev->u.ctrl.type = v4l2_ctrl.type;
+	ev->u.ctrl.flags = v4l2_ctrl.flags;
+	ev->u.ctrl.minimum = v4l2_ctrl.minimum;
+	ev->u.ctrl.maximum = v4l2_ctrl.maximum;
+	ev->u.ctrl.step = v4l2_ctrl.step;
+	ev->u.ctrl.default_value = v4l2_ctrl.default_value;
+}
+
+static void uvc_ctrl_send_event(struct uvc_fh *handle,
+	struct uvc_control *ctrl, struct uvc_control_mapping *mapping,
+	s32 value, u32 changes)
+{
+	struct v4l2_subscribed_event *sev;
+	struct v4l2_event ev;
+
+	if (list_empty(&mapping->ev_subs))
+		return;
+
+	uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, value, changes);
+
+	list_for_each_entry(sev, &mapping->ev_subs, node) {
+		if (sev->fh && (sev->fh != &handle->vfh ||
+		    (sev->flags & V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK) ||
+		    (changes & V4L2_EVENT_CTRL_CH_FLAGS)))
+			v4l2_event_queue_fh(sev->fh, &ev);
+	}
+}
+
+static void uvc_ctrl_send_slave_event(struct uvc_fh *handle,
+	struct uvc_control *master, u32 slave_id,
+	const struct v4l2_ext_control *xctrls, unsigned int xctrls_count)
+{
+	struct uvc_control_mapping *mapping = NULL;
+	struct uvc_control *ctrl = NULL;
+	u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
+	unsigned int i;
+	s32 val = 0;
+
+	/*
+	 * We can skip sending an event for the slave if the slave
+	 * is being modified in the same transaction.
+	 */
+	for (i = 0; i < xctrls_count; i++) {
+		if (xctrls[i].id == slave_id)
+			return;
+	}
+
+	__uvc_find_control(master->entity, slave_id, &mapping, &ctrl, 0);
+	if (ctrl == NULL)
+		return;
+
+	if (__uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0)
+		changes |= V4L2_EVENT_CTRL_CH_VALUE;
+
+	uvc_ctrl_send_event(handle, ctrl, mapping, val, changes);
+}
+
+static void uvc_ctrl_send_events(struct uvc_fh *handle,
+	const struct v4l2_ext_control *xctrls, unsigned int xctrls_count)
+{
+	struct uvc_control_mapping *mapping;
+	struct uvc_control *ctrl;
+	u32 changes = V4L2_EVENT_CTRL_CH_VALUE;
+	unsigned int i;
+	unsigned int j;
+
+	for (i = 0; i < xctrls_count; ++i) {
+		ctrl = uvc_find_control(handle->chain, xctrls[i].id, &mapping);
+
+		for (j = 0; j < ARRAY_SIZE(mapping->slave_ids); ++j) {
+			if (!mapping->slave_ids[j])
+				break;
+			uvc_ctrl_send_slave_event(handle, ctrl,
+						  mapping->slave_ids[j],
+						  xctrls, xctrls_count);
+		}
+
+		/*
+		 * If the master is being modified in the same transaction
+		 * flags may change too.
+		 */
+		if (mapping->master_id) {
+			for (j = 0; j < xctrls_count; j++) {
+				if (xctrls[j].id == mapping->master_id) {
+					changes |= V4L2_EVENT_CTRL_CH_FLAGS;
+					break;
+				}
+			}
+		}
+
+		uvc_ctrl_send_event(handle, ctrl, mapping, xctrls[i].value,
+				    changes);
+	}
+}
+
+static int uvc_ctrl_add_event(struct v4l2_subscribed_event *sev, unsigned elems)
+{
+	struct uvc_fh *handle = container_of(sev->fh, struct uvc_fh, vfh);
+	struct uvc_control_mapping *mapping;
+	struct uvc_control *ctrl;
+	int ret;
+
+	ret = mutex_lock_interruptible(&handle->chain->ctrl_mutex);
+	if (ret < 0)
+		return -ERESTARTSYS;
+
+	ctrl = uvc_find_control(handle->chain, sev->id, &mapping);
+	if (ctrl == NULL) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	list_add_tail(&sev->node, &mapping->ev_subs);
+	if (sev->flags & V4L2_EVENT_SUB_FL_SEND_INITIAL) {
+		struct v4l2_event ev;
+		u32 changes = V4L2_EVENT_CTRL_CH_FLAGS;
+		s32 val = 0;
+
+		if (__uvc_ctrl_get(handle->chain, ctrl, mapping, &val) == 0)
+			changes |= V4L2_EVENT_CTRL_CH_VALUE;
+
+		uvc_ctrl_fill_event(handle->chain, &ev, ctrl, mapping, val,
+				    changes);
+		/* Mark the queue as active, allowing this initial
+		   event to be accepted. */
+		sev->elems = elems;
+		v4l2_event_queue_fh(sev->fh, &ev);
+	}
+
+done:
+	mutex_unlock(&handle->chain->ctrl_mutex);
+	return ret;
+}
+
+static void uvc_ctrl_del_event(struct v4l2_subscribed_event *sev)
+{
+	struct uvc_fh *handle = container_of(sev->fh, struct uvc_fh, vfh);
+
+	mutex_lock(&handle->chain->ctrl_mutex);
+	list_del(&sev->node);
+	mutex_unlock(&handle->chain->ctrl_mutex);
+}
+
+const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops = {
+	.add = uvc_ctrl_add_event,
+	.del = uvc_ctrl_del_event,
+	.replace = v4l2_ctrl_replace,
+	.merge = v4l2_ctrl_merge,
+};
+
+/* --------------------------------------------------------------------------
+ * Control transactions
+ *
+ * To make extended set operations as atomic as the hardware allows, controls
+ * are handled using begin/commit/rollback operations.
+ *
+ * At the beginning of a set request, uvc_ctrl_begin should be called to
+ * initialize the request. This function acquires the control lock.
+ *
+ * When setting a control, the new value is stored in the control data field
+ * at position UVC_CTRL_DATA_CURRENT. The control is then marked as dirty for
+ * later processing. If the UVC and V4L2 control sizes differ, the current
+ * value is loaded from the hardware before storing the new value in the data
+ * field.
+ *
+ * After processing all controls in the transaction, uvc_ctrl_commit or
+ * uvc_ctrl_rollback must be called to apply the pending changes to the
+ * hardware or revert them. When applying changes, all controls marked as
+ * dirty will be modified in the UVC device, and the dirty flag will be
+ * cleared. When reverting controls, the control data field
+ * UVC_CTRL_DATA_CURRENT is reverted to its previous value
+ * (UVC_CTRL_DATA_BACKUP) for all dirty controls. Both functions release the
+ * control lock.
+ */
+int uvc_ctrl_begin(struct uvc_video_chain *chain)
+{
+	return mutex_lock_interruptible(&chain->ctrl_mutex) ? -ERESTARTSYS : 0;
+}
+
+static int uvc_ctrl_commit_entity(struct uvc_device *dev,
+	struct uvc_entity *entity, int rollback)
+{
+	struct uvc_control *ctrl;
+	unsigned int i;
+	int ret;
+
+	if (entity == NULL)
+		return 0;
+
+	for (i = 0; i < entity->ncontrols; ++i) {
+		ctrl = &entity->controls[i];
+		if (!ctrl->initialized)
+			continue;
+
+		/* Reset the loaded flag for auto-update controls that were
+		 * marked as loaded in uvc_ctrl_get/uvc_ctrl_set to prevent
+		 * uvc_ctrl_get from using the cached value, and for write-only
+		 * controls to prevent uvc_ctrl_set from setting bits not
+		 * explicitly set by the user.
+		 */
+		if (ctrl->info.flags & UVC_CTRL_FLAG_AUTO_UPDATE ||
+		    !(ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR))
+			ctrl->loaded = 0;
+
+		if (!ctrl->dirty)
+			continue;
+
+		if (!rollback)
+			ret = uvc_query_ctrl(dev, UVC_SET_CUR, ctrl->entity->id,
+				dev->intfnum, ctrl->info.selector,
+				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+				ctrl->info.size);
+		else
+			ret = 0;
+
+		if (rollback || ret < 0)
+			memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+			       uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
+			       ctrl->info.size);
+
+		ctrl->dirty = 0;
+
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
+		      const struct v4l2_ext_control *xctrls,
+		      unsigned int xctrls_count)
+{
+	struct uvc_video_chain *chain = handle->chain;
+	struct uvc_entity *entity;
+	int ret = 0;
+
+	/* Find the control. */
+	list_for_each_entry(entity, &chain->entities, chain) {
+		ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback);
+		if (ret < 0)
+			goto done;
+	}
+
+	if (!rollback)
+		uvc_ctrl_send_events(handle, xctrls, xctrls_count);
+done:
+	mutex_unlock(&chain->ctrl_mutex);
+	return ret;
+}
+
+int uvc_ctrl_get(struct uvc_video_chain *chain,
+	struct v4l2_ext_control *xctrl)
+{
+	struct uvc_control *ctrl;
+	struct uvc_control_mapping *mapping;
+
+	ctrl = uvc_find_control(chain, xctrl->id, &mapping);
+	if (ctrl == NULL)
+		return -EINVAL;
+
+	return __uvc_ctrl_get(chain, ctrl, mapping, &xctrl->value);
+}
+
+int uvc_ctrl_set(struct uvc_video_chain *chain,
+	struct v4l2_ext_control *xctrl)
+{
+	struct uvc_control *ctrl;
+	struct uvc_control_mapping *mapping;
+	s32 value;
+	u32 step;
+	s32 min;
+	s32 max;
+	int ret;
+
+	ctrl = uvc_find_control(chain, xctrl->id, &mapping);
+	if (ctrl == NULL)
+		return -EINVAL;
+	if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
+		return -EACCES;
+
+	/* Clamp out of range values. */
+	switch (mapping->v4l2_type) {
+	case V4L2_CTRL_TYPE_INTEGER:
+		if (!ctrl->cached) {
+			ret = uvc_ctrl_populate_cache(chain, ctrl);
+			if (ret < 0)
+				return ret;
+		}
+
+		min = mapping->get(mapping, UVC_GET_MIN,
+				   uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MIN));
+		max = mapping->get(mapping, UVC_GET_MAX,
+				   uvc_ctrl_data(ctrl, UVC_CTRL_DATA_MAX));
+		step = mapping->get(mapping, UVC_GET_RES,
+				    uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
+		if (step == 0)
+			step = 1;
+
+		xctrl->value = min + ((u32)(xctrl->value - min) + step / 2)
+			     / step * step;
+		if (mapping->data_type == UVC_CTRL_DATA_TYPE_SIGNED)
+			xctrl->value = clamp(xctrl->value, min, max);
+		else
+			xctrl->value = clamp_t(u32, xctrl->value, min, max);
+		value = xctrl->value;
+		break;
+
+	case V4L2_CTRL_TYPE_BOOLEAN:
+		xctrl->value = clamp(xctrl->value, 0, 1);
+		value = xctrl->value;
+		break;
+
+	case V4L2_CTRL_TYPE_MENU:
+		if (xctrl->value < 0 || xctrl->value >= mapping->menu_count)
+			return -ERANGE;
+		value = mapping->menu_info[xctrl->value].value;
+
+		/* Valid menu indices are reported by the GET_RES request for
+		 * UVC controls that support it.
+		 */
+		if (mapping->data_type == UVC_CTRL_DATA_TYPE_BITMASK &&
+		    (ctrl->info.flags & UVC_CTRL_FLAG_GET_RES)) {
+			if (!ctrl->cached) {
+				ret = uvc_ctrl_populate_cache(chain, ctrl);
+				if (ret < 0)
+					return ret;
+			}
+
+			step = mapping->get(mapping, UVC_GET_RES,
+					uvc_ctrl_data(ctrl, UVC_CTRL_DATA_RES));
+			if (!(step & value))
+				return -EINVAL;
+		}
+
+		break;
+
+	default:
+		value = xctrl->value;
+		break;
+	}
+
+	/* If the mapping doesn't span the whole UVC control, the current value
+	 * needs to be loaded from the device to perform the read-modify-write
+	 * operation.
+	 */
+	if (!ctrl->loaded && (ctrl->info.size * 8) != mapping->size) {
+		if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0) {
+			memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+				0, ctrl->info.size);
+		} else {
+			ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR,
+				ctrl->entity->id, chain->dev->intfnum,
+				ctrl->info.selector,
+				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+				ctrl->info.size);
+			if (ret < 0)
+				return ret;
+		}
+
+		ctrl->loaded = 1;
+	}
+
+	/* Backup the current value in case we need to rollback later. */
+	if (!ctrl->dirty) {
+		memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
+		       uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
+		       ctrl->info.size);
+	}
+
+	mapping->set(mapping, value,
+		uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
+
+	ctrl->dirty = 1;
+	ctrl->modified = 1;
+	return 0;
+}
+
+/* --------------------------------------------------------------------------
+ * Dynamic controls
+ */
+
+static void uvc_ctrl_fixup_xu_info(struct uvc_device *dev,
+	const struct uvc_control *ctrl, struct uvc_control_info *info)
+{
+	struct uvc_ctrl_fixup {
+		struct usb_device_id id;
+		u8 entity;
+		u8 selector;
+		u8 flags;
+	};
+
+	static const struct uvc_ctrl_fixup fixups[] = {
+		{ { USB_DEVICE(0x046d, 0x08c2) }, 9, 1,
+			UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX |
+			UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_SET_CUR |
+			UVC_CTRL_FLAG_AUTO_UPDATE },
+		{ { USB_DEVICE(0x046d, 0x08cc) }, 9, 1,
+			UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX |
+			UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_SET_CUR |
+			UVC_CTRL_FLAG_AUTO_UPDATE },
+		{ { USB_DEVICE(0x046d, 0x0994) }, 9, 1,
+			UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX |
+			UVC_CTRL_FLAG_GET_DEF | UVC_CTRL_FLAG_SET_CUR |
+			UVC_CTRL_FLAG_AUTO_UPDATE },
+	};
+
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(fixups); ++i) {
+		if (!usb_match_one_id(dev->intf, &fixups[i].id))
+			continue;
+
+		if (fixups[i].entity == ctrl->entity->id &&
+		    fixups[i].selector == info->selector) {
+			info->flags = fixups[i].flags;
+			return;
+		}
+	}
+}
+
+/*
+ * Query control information (size and flags) for XU controls.
+ */
+static int uvc_ctrl_fill_xu_info(struct uvc_device *dev,
+	const struct uvc_control *ctrl, struct uvc_control_info *info)
+{
+	u8 *data;
+	int ret;
+
+	data = kmalloc(2, GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	memcpy(info->entity, ctrl->entity->extension.guidExtensionCode,
+	       sizeof(info->entity));
+	info->index = ctrl->index;
+	info->selector = ctrl->index + 1;
+
+	/* Query and verify the control length (GET_LEN) */
+	ret = uvc_query_ctrl(dev, UVC_GET_LEN, ctrl->entity->id, dev->intfnum,
+			     info->selector, data, 2);
+	if (ret < 0) {
+		uvc_trace(UVC_TRACE_CONTROL,
+			  "GET_LEN failed on control %pUl/%u (%d).\n",
+			   info->entity, info->selector, ret);
+		goto done;
+	}
+
+	info->size = le16_to_cpup((__le16 *)data);
+
+	/* Query the control information (GET_INFO) */
+	ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum,
+			     info->selector, data, 1);
+	if (ret < 0) {
+		uvc_trace(UVC_TRACE_CONTROL,
+			  "GET_INFO failed on control %pUl/%u (%d).\n",
+			  info->entity, info->selector, ret);
+		goto done;
+	}
+
+	info->flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX
+		    | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF
+		    | (data[0] & UVC_CONTROL_CAP_GET ?
+		       UVC_CTRL_FLAG_GET_CUR : 0)
+		    | (data[0] & UVC_CONTROL_CAP_SET ?
+		       UVC_CTRL_FLAG_SET_CUR : 0)
+		    | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ?
+		       UVC_CTRL_FLAG_AUTO_UPDATE : 0);
+
+	uvc_ctrl_fixup_xu_info(dev, ctrl, info);
+
+	uvc_trace(UVC_TRACE_CONTROL, "XU control %pUl/%u queried: len %u, "
+		  "flags { get %u set %u auto %u }.\n",
+		  info->entity, info->selector, info->size,
+		  (info->flags & UVC_CTRL_FLAG_GET_CUR) ? 1 : 0,
+		  (info->flags & UVC_CTRL_FLAG_SET_CUR) ? 1 : 0,
+		  (info->flags & UVC_CTRL_FLAG_AUTO_UPDATE) ? 1 : 0);
+
+done:
+	kfree(data);
+	return ret;
+}
+
+static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl,
+	const struct uvc_control_info *info);
+
+static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev,
+	struct uvc_control *ctrl)
+{
+	struct uvc_control_info info;
+	int ret;
+
+	if (ctrl->initialized)
+		return 0;
+
+	ret = uvc_ctrl_fill_xu_info(dev, ctrl, &info);
+	if (ret < 0)
+		return ret;
+
+	ret = uvc_ctrl_add_info(dev, ctrl, &info);
+	if (ret < 0)
+		uvc_trace(UVC_TRACE_CONTROL, "Failed to initialize control "
+			  "%pUl/%u on device %s entity %u\n", info.entity,
+			  info.selector, dev->udev->devpath, ctrl->entity->id);
+
+	return ret;
+}
+
+int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
+	struct uvc_xu_control_query *xqry)
+{
+	struct uvc_entity *entity;
+	struct uvc_control *ctrl;
+	unsigned int i, found = 0;
+	__u32 reqflags;
+	__u16 size;
+	__u8 *data = NULL;
+	int ret;
+
+	/* Find the extension unit. */
+	list_for_each_entry(entity, &chain->entities, chain) {
+		if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT &&
+		    entity->id == xqry->unit)
+			break;
+	}
+
+	if (entity->id != xqry->unit) {
+		uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n",
+			xqry->unit);
+		return -ENOENT;
+	}
+
+	/* Find the control and perform delayed initialization if needed. */
+	for (i = 0; i < entity->ncontrols; ++i) {
+		ctrl = &entity->controls[i];
+		if (ctrl->index == xqry->selector - 1) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found) {
+		uvc_trace(UVC_TRACE_CONTROL, "Control %pUl/%u not found.\n",
+			entity->extension.guidExtensionCode, xqry->selector);
+		return -ENOENT;
+	}
+
+	if (mutex_lock_interruptible(&chain->ctrl_mutex))
+		return -ERESTARTSYS;
+
+	ret = uvc_ctrl_init_xu_ctrl(chain->dev, ctrl);
+	if (ret < 0) {
+		ret = -ENOENT;
+		goto done;
+	}
+
+	/* Validate the required buffer size and flags for the request */
+	reqflags = 0;
+	size = ctrl->info.size;
+
+	switch (xqry->query) {
+	case UVC_GET_CUR:
+		reqflags = UVC_CTRL_FLAG_GET_CUR;
+		break;
+	case UVC_GET_MIN:
+		reqflags = UVC_CTRL_FLAG_GET_MIN;
+		break;
+	case UVC_GET_MAX:
+		reqflags = UVC_CTRL_FLAG_GET_MAX;
+		break;
+	case UVC_GET_DEF:
+		reqflags = UVC_CTRL_FLAG_GET_DEF;
+		break;
+	case UVC_GET_RES:
+		reqflags = UVC_CTRL_FLAG_GET_RES;
+		break;
+	case UVC_SET_CUR:
+		reqflags = UVC_CTRL_FLAG_SET_CUR;
+		break;
+	case UVC_GET_LEN:
+		size = 2;
+		break;
+	case UVC_GET_INFO:
+		size = 1;
+		break;
+	default:
+		ret = -EINVAL;
+		goto done;
+	}
+
+	if (size != xqry->size) {
+		ret = -ENOBUFS;
+		goto done;
+	}
+
+	if (reqflags && !(ctrl->info.flags & reqflags)) {
+		ret = -EBADRQC;
+		goto done;
+	}
+
+	data = kmalloc(size, GFP_KERNEL);
+	if (data == NULL) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	if (xqry->query == UVC_SET_CUR &&
+	    copy_from_user(data, xqry->data, size)) {
+		ret = -EFAULT;
+		goto done;
+	}
+
+	ret = uvc_query_ctrl(chain->dev, xqry->query, xqry->unit,
+			     chain->dev->intfnum, xqry->selector, data, size);
+	if (ret < 0)
+		goto done;
+
+	if (xqry->query != UVC_SET_CUR &&
+	    copy_to_user(xqry->data, data, size))
+		ret = -EFAULT;
+done:
+	kfree(data);
+	mutex_unlock(&chain->ctrl_mutex);
+	return ret;
+}
+
+/* --------------------------------------------------------------------------
+ * Suspend/resume
+ */
+
+/*
+ * Restore control values after resume, skipping controls that haven't been
+ * changed.
+ *
+ * TODO
+ * - Don't restore modified controls that are back to their default value.
+ * - Handle restore order (Auto-Exposure Mode should be restored before
+ *   Exposure Time).
+ */
+int uvc_ctrl_restore_values(struct uvc_device *dev)
+{
+	struct uvc_control *ctrl;
+	struct uvc_entity *entity;
+	unsigned int i;
+	int ret;
+
+	/* Walk the entities list and restore controls when possible. */
+	list_for_each_entry(entity, &dev->entities, list) {
+
+		for (i = 0; i < entity->ncontrols; ++i) {
+			ctrl = &entity->controls[i];
+
+			if (!ctrl->initialized || !ctrl->modified ||
+			    (ctrl->info.flags & UVC_CTRL_FLAG_RESTORE) == 0)
+				continue;
+
+			printk(KERN_INFO "restoring control %pUl/%u/%u\n",
+				ctrl->info.entity, ctrl->info.index,
+				ctrl->info.selector);
+			ctrl->dirty = 1;
+		}
+
+		ret = uvc_ctrl_commit_entity(dev, entity, 0);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+/* --------------------------------------------------------------------------
+ * Control and mapping handling
+ */
+
+/*
+ * Add control information to a given control.
+ */
+static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl,
+	const struct uvc_control_info *info)
+{
+	int ret = 0;
+
+	ctrl->info = *info;
+	INIT_LIST_HEAD(&ctrl->info.mappings);
+
+	/* Allocate an array to save control values (cur, def, max, etc.) */
+	ctrl->uvc_data = kzalloc(ctrl->info.size * UVC_CTRL_DATA_LAST + 1,
+				 GFP_KERNEL);
+	if (ctrl->uvc_data == NULL) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	ctrl->initialized = 1;
+
+	uvc_trace(UVC_TRACE_CONTROL, "Added control %pUl/%u to device %s "
+		"entity %u\n", ctrl->info.entity, ctrl->info.selector,
+		dev->udev->devpath, ctrl->entity->id);
+
+done:
+	if (ret < 0)
+		kfree(ctrl->uvc_data);
+	return ret;
+}
+
+/*
+ * Add a control mapping to a given control.
+ */
+static int __uvc_ctrl_add_mapping(struct uvc_device *dev,
+	struct uvc_control *ctrl, const struct uvc_control_mapping *mapping)
+{
+	struct uvc_control_mapping *map;
+	unsigned int size;
+
+	/* Most mappings come from static kernel data and need to be duplicated.
+	 * Mappings that come from userspace will be unnecessarily duplicated,
+	 * this could be optimized.
+	 */
+	map = kmemdup(mapping, sizeof(*mapping), GFP_KERNEL);
+	if (map == NULL)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&map->ev_subs);
+
+	size = sizeof(*mapping->menu_info) * mapping->menu_count;
+	map->menu_info = kmemdup(mapping->menu_info, size, GFP_KERNEL);
+	if (map->menu_info == NULL) {
+		kfree(map);
+		return -ENOMEM;
+	}
+
+	if (map->get == NULL)
+		map->get = uvc_get_le_value;
+	if (map->set == NULL)
+		map->set = uvc_set_le_value;
+
+	list_add_tail(&map->list, &ctrl->info.mappings);
+	uvc_trace(UVC_TRACE_CONTROL,
+		"Adding mapping '%s' to control %pUl/%u.\n",
+		map->name, ctrl->info.entity, ctrl->info.selector);
+
+	return 0;
+}
+
+int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
+	const struct uvc_control_mapping *mapping)
+{
+	struct uvc_device *dev = chain->dev;
+	struct uvc_control_mapping *map;
+	struct uvc_entity *entity;
+	struct uvc_control *ctrl;
+	int found = 0;
+	int ret;
+
+	if (mapping->id & ~V4L2_CTRL_ID_MASK) {
+		uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', control "
+			"id 0x%08x is invalid.\n", mapping->name,
+			mapping->id);
+		return -EINVAL;
+	}
+
+	/* Search for the matching (GUID/CS) control on the current chain */
+	list_for_each_entry(entity, &chain->entities, chain) {
+		unsigned int i;
+
+		if (UVC_ENTITY_TYPE(entity) != UVC_VC_EXTENSION_UNIT ||
+		    !uvc_entity_match_guid(entity, mapping->entity))
+			continue;
+
+		for (i = 0; i < entity->ncontrols; ++i) {
+			ctrl = &entity->controls[i];
+			if (ctrl->index == mapping->selector - 1) {
+				found = 1;
+				break;
+			}
+		}
+
+		if (found)
+			break;
+	}
+	if (!found)
+		return -ENOENT;
+
+	if (mutex_lock_interruptible(&chain->ctrl_mutex))
+		return -ERESTARTSYS;
+
+	/* Perform delayed initialization of XU controls */
+	ret = uvc_ctrl_init_xu_ctrl(dev, ctrl);
+	if (ret < 0) {
+		ret = -ENOENT;
+		goto done;
+	}
+
+	list_for_each_entry(map, &ctrl->info.mappings, list) {
+		if (mapping->id == map->id) {
+			uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', "
+				"control id 0x%08x already exists.\n",
+				mapping->name, mapping->id);
+			ret = -EEXIST;
+			goto done;
+		}
+	}
+
+	/* Prevent excess memory consumption */
+	if (atomic_inc_return(&dev->nmappings) > UVC_MAX_CONTROL_MAPPINGS) {
+		atomic_dec(&dev->nmappings);
+		uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s', maximum "
+			"mappings count (%u) exceeded.\n", mapping->name,
+			UVC_MAX_CONTROL_MAPPINGS);
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	ret = __uvc_ctrl_add_mapping(dev, ctrl, mapping);
+	if (ret < 0)
+		atomic_dec(&dev->nmappings);
+
+done:
+	mutex_unlock(&chain->ctrl_mutex);
+	return ret;
+}
+
+/*
+ * Prune an entity of its bogus controls using a blacklist. Bogus controls
+ * are currently the ones that crash the camera or unconditionally return an
+ * error when queried.
+ */
+static void uvc_ctrl_prune_entity(struct uvc_device *dev,
+	struct uvc_entity *entity)
+{
+	struct uvc_ctrl_blacklist {
+		struct usb_device_id id;
+		u8 index;
+	};
+
+	static const struct uvc_ctrl_blacklist processing_blacklist[] = {
+		{ { USB_DEVICE(0x13d3, 0x509b) }, 9 }, /* Gain */
+		{ { USB_DEVICE(0x1c4f, 0x3000) }, 6 }, /* WB Temperature */
+		{ { USB_DEVICE(0x5986, 0x0241) }, 2 }, /* Hue */
+	};
+	static const struct uvc_ctrl_blacklist camera_blacklist[] = {
+		{ { USB_DEVICE(0x06f8, 0x3005) }, 9 }, /* Zoom, Absolute */
+	};
+
+	const struct uvc_ctrl_blacklist *blacklist;
+	unsigned int size;
+	unsigned int count;
+	unsigned int i;
+	u8 *controls;
+
+	switch (UVC_ENTITY_TYPE(entity)) {
+	case UVC_VC_PROCESSING_UNIT:
+		blacklist = processing_blacklist;
+		count = ARRAY_SIZE(processing_blacklist);
+		controls = entity->processing.bmControls;
+		size = entity->processing.bControlSize;
+		break;
+
+	case UVC_ITT_CAMERA:
+		blacklist = camera_blacklist;
+		count = ARRAY_SIZE(camera_blacklist);
+		controls = entity->camera.bmControls;
+		size = entity->camera.bControlSize;
+		break;
+
+	default:
+		return;
+	}
+
+	for (i = 0; i < count; ++i) {
+		if (!usb_match_one_id(dev->intf, &blacklist[i].id))
+			continue;
+
+		if (blacklist[i].index >= 8 * size ||
+		    !uvc_test_bit(controls, blacklist[i].index))
+			continue;
+
+		uvc_trace(UVC_TRACE_CONTROL, "%u/%u control is black listed, "
+			"removing it.\n", entity->id, blacklist[i].index);
+
+		uvc_clear_bit(controls, blacklist[i].index);
+	}
+}
+
+/*
+ * Add control information and hardcoded stock control mappings to the given
+ * device.
+ */
+static void uvc_ctrl_init_ctrl(struct uvc_device *dev, struct uvc_control *ctrl)
+{
+	const struct uvc_control_info *info = uvc_ctrls;
+	const struct uvc_control_info *iend = info + ARRAY_SIZE(uvc_ctrls);
+	const struct uvc_control_mapping *mapping = uvc_ctrl_mappings;
+	const struct uvc_control_mapping *mend =
+		mapping + ARRAY_SIZE(uvc_ctrl_mappings);
+
+	/* XU controls initialization requires querying the device for control
+	 * information. As some buggy UVC devices will crash when queried
+	 * repeatedly in a tight loop, delay XU controls initialization until
+	 * first use.
+	 */
+	if (UVC_ENTITY_TYPE(ctrl->entity) == UVC_VC_EXTENSION_UNIT)
+		return;
+
+	for (; info < iend; ++info) {
+		if (uvc_entity_match_guid(ctrl->entity, info->entity) &&
+		    ctrl->index == info->index) {
+			uvc_ctrl_add_info(dev, ctrl, info);
+			break;
+		 }
+	}
+
+	if (!ctrl->initialized)
+		return;
+
+	for (; mapping < mend; ++mapping) {
+		if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
+		    ctrl->info.selector == mapping->selector)
+			__uvc_ctrl_add_mapping(dev, ctrl, mapping);
+	}
+}
+
+/*
+ * Initialize device controls.
+ */
+int uvc_ctrl_init_device(struct uvc_device *dev)
+{
+	struct uvc_entity *entity;
+	unsigned int i;
+
+	/* Walk the entities list and instantiate controls */
+	list_for_each_entry(entity, &dev->entities, list) {
+		struct uvc_control *ctrl;
+		unsigned int bControlSize = 0, ncontrols;
+		__u8 *bmControls = NULL;
+
+		if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT) {
+			bmControls = entity->extension.bmControls;
+			bControlSize = entity->extension.bControlSize;
+		} else if (UVC_ENTITY_TYPE(entity) == UVC_VC_PROCESSING_UNIT) {
+			bmControls = entity->processing.bmControls;
+			bControlSize = entity->processing.bControlSize;
+		} else if (UVC_ENTITY_TYPE(entity) == UVC_ITT_CAMERA) {
+			bmControls = entity->camera.bmControls;
+			bControlSize = entity->camera.bControlSize;
+		}
+
+		/* Remove bogus/blacklisted controls */
+		uvc_ctrl_prune_entity(dev, entity);
+
+		/* Count supported controls and allocate the controls array */
+		ncontrols = memweight(bmControls, bControlSize);
+		if (ncontrols == 0)
+			continue;
+
+		entity->controls = kcalloc(ncontrols, sizeof(*ctrl),
+					   GFP_KERNEL);
+		if (entity->controls == NULL)
+			return -ENOMEM;
+		entity->ncontrols = ncontrols;
+
+		/* Initialize all supported controls */
+		ctrl = entity->controls;
+		for (i = 0; i < bControlSize * 8; ++i) {
+			if (uvc_test_bit(bmControls, i) == 0)
+				continue;
+
+			ctrl->entity = entity;
+			ctrl->index = i;
+
+			uvc_ctrl_init_ctrl(dev, ctrl);
+			ctrl++;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Cleanup device controls.
+ */
+static void uvc_ctrl_cleanup_mappings(struct uvc_device *dev,
+	struct uvc_control *ctrl)
+{
+	struct uvc_control_mapping *mapping, *nm;
+
+	list_for_each_entry_safe(mapping, nm, &ctrl->info.mappings, list) {
+		list_del(&mapping->list);
+		kfree(mapping->menu_info);
+		kfree(mapping);
+	}
+}
+
+void uvc_ctrl_cleanup_device(struct uvc_device *dev)
+{
+	struct uvc_entity *entity;
+	unsigned int i;
+
+	/* Free controls and control mappings for all entities. */
+	list_for_each_entry(entity, &dev->entities, list) {
+		for (i = 0; i < entity->ncontrols; ++i) {
+			struct uvc_control *ctrl = &entity->controls[i];
+
+			if (!ctrl->initialized)
+				continue;
+
+			uvc_ctrl_cleanup_mappings(dev, ctrl);
+			kfree(ctrl->uvc_data);
+		}
+
+		kfree(entity->controls);
+	}
+}
diff --git a/kernel/drivers/media/usb/uvc/uvc_debugfs.c b/kernel/drivers/media/usb/uvc/uvc_debugfs.c
new file mode 100644
index 000000000..14561a5ab
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_debugfs.c
@@ -0,0 +1,136 @@
+/*
+ *      uvc_debugfs.c --  USB Video Class driver - Debugging support
+ *
+ *      Copyright (C) 2011
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+#include "uvcvideo.h"
+
+/* -----------------------------------------------------------------------------
+ * Statistics
+ */
+
+#define UVC_DEBUGFS_BUF_SIZE	1024
+
+struct uvc_debugfs_buffer {
+	size_t count;
+	char data[UVC_DEBUGFS_BUF_SIZE];
+};
+
+static int uvc_debugfs_stats_open(struct inode *inode, struct file *file)
+{
+	struct uvc_streaming *stream = inode->i_private;
+	struct uvc_debugfs_buffer *buf;
+
+	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	buf->count = uvc_video_stats_dump(stream, buf->data, sizeof(buf->data));
+
+	file->private_data = buf;
+	return 0;
+}
+
+static ssize_t uvc_debugfs_stats_read(struct file *file, char __user *user_buf,
+				      size_t nbytes, loff_t *ppos)
+{
+	struct uvc_debugfs_buffer *buf = file->private_data;
+
+	return simple_read_from_buffer(user_buf, nbytes, ppos, buf->data,
+				       buf->count);
+}
+
+static int uvc_debugfs_stats_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	file->private_data = NULL;
+
+	return 0;
+}
+
+static const struct file_operations uvc_debugfs_stats_fops = {
+	.owner = THIS_MODULE,
+	.open = uvc_debugfs_stats_open,
+	.llseek = no_llseek,
+	.read = uvc_debugfs_stats_read,
+	.release = uvc_debugfs_stats_release,
+};
+
+/* -----------------------------------------------------------------------------
+ * Global and stream initialization/cleanup
+ */
+
+static struct dentry *uvc_debugfs_root_dir;
+
+int uvc_debugfs_init_stream(struct uvc_streaming *stream)
+{
+	struct usb_device *udev = stream->dev->udev;
+	struct dentry *dent;
+	char dir_name[32];
+
+	if (uvc_debugfs_root_dir == NULL)
+		return -ENODEV;
+
+	sprintf(dir_name, "%u-%u", udev->bus->busnum, udev->devnum);
+
+	dent = debugfs_create_dir(dir_name, uvc_debugfs_root_dir);
+	if (IS_ERR_OR_NULL(dent)) {
+		uvc_printk(KERN_INFO, "Unable to create debugfs %s "
+			   "directory.\n", dir_name);
+		return -ENODEV;
+	}
+
+	stream->debugfs_dir = dent;
+
+	dent = debugfs_create_file("stats", 0444, stream->debugfs_dir,
+				   stream, &uvc_debugfs_stats_fops);
+	if (IS_ERR_OR_NULL(dent)) {
+		uvc_printk(KERN_INFO, "Unable to create debugfs stats file.\n");
+		uvc_debugfs_cleanup_stream(stream);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
+{
+	if (stream->debugfs_dir == NULL)
+		return;
+
+	debugfs_remove_recursive(stream->debugfs_dir);
+	stream->debugfs_dir = NULL;
+}
+
+int uvc_debugfs_init(void)
+{
+	struct dentry *dir;
+
+	dir = debugfs_create_dir("uvcvideo", usb_debug_root);
+	if (IS_ERR_OR_NULL(dir)) {
+		uvc_printk(KERN_INFO, "Unable to create debugfs directory\n");
+		return -ENODATA;
+	}
+
+	uvc_debugfs_root_dir = dir;
+	return 0;
+}
+
+void uvc_debugfs_cleanup(void)
+{
+	if (uvc_debugfs_root_dir != NULL)
+		debugfs_remove_recursive(uvc_debugfs_root_dir);
+}
diff --git a/kernel/drivers/media/usb/uvc/uvc_driver.c b/kernel/drivers/media/usb/uvc/uvc_driver.c
new file mode 100644
index 000000000..5970dd6a1
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_driver.c
@@ -0,0 +1,2590 @@
+/*
+ *      uvc_driver.c  --  USB Video Class driver
+ *
+ *      Copyright (C) 2005-2010
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/atomic.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <linux/version.h>
+#include <asm/unaligned.h>
+
+#include <media/v4l2-common.h>
+
+#include "uvcvideo.h"
+
+#define DRIVER_AUTHOR		"Laurent Pinchart " \
+				"<laurent.pinchart@ideasonboard.com>"
+#define DRIVER_DESC		"USB Video Class driver"
+
+unsigned int uvc_clock_param = CLOCK_MONOTONIC;
+unsigned int uvc_no_drop_param;
+static unsigned int uvc_quirks_param = -1;
+unsigned int uvc_trace_param;
+unsigned int uvc_timeout_param = UVC_CTRL_STREAMING_TIMEOUT;
+
+/* ------------------------------------------------------------------------
+ * Video formats
+ */
+
+static struct uvc_format_desc uvc_fmts[] = {
+	{
+		.name		= "YUV 4:2:2 (YUYV)",
+		.guid		= UVC_GUID_FORMAT_YUY2,
+		.fcc		= V4L2_PIX_FMT_YUYV,
+	},
+	{
+		.name		= "YUV 4:2:2 (YUYV)",
+		.guid		= UVC_GUID_FORMAT_YUY2_ISIGHT,
+		.fcc		= V4L2_PIX_FMT_YUYV,
+	},
+	{
+		.name		= "YUV 4:2:0 (NV12)",
+		.guid		= UVC_GUID_FORMAT_NV12,
+		.fcc		= V4L2_PIX_FMT_NV12,
+	},
+	{
+		.name		= "MJPEG",
+		.guid		= UVC_GUID_FORMAT_MJPEG,
+		.fcc		= V4L2_PIX_FMT_MJPEG,
+	},
+	{
+		.name		= "YVU 4:2:0 (YV12)",
+		.guid		= UVC_GUID_FORMAT_YV12,
+		.fcc		= V4L2_PIX_FMT_YVU420,
+	},
+	{
+		.name		= "YUV 4:2:0 (I420)",
+		.guid		= UVC_GUID_FORMAT_I420,
+		.fcc		= V4L2_PIX_FMT_YUV420,
+	},
+	{
+		.name		= "YUV 4:2:0 (M420)",
+		.guid		= UVC_GUID_FORMAT_M420,
+		.fcc		= V4L2_PIX_FMT_M420,
+	},
+	{
+		.name		= "YUV 4:2:2 (UYVY)",
+		.guid		= UVC_GUID_FORMAT_UYVY,
+		.fcc		= V4L2_PIX_FMT_UYVY,
+	},
+	{
+		.name		= "Greyscale 8-bit (Y800)",
+		.guid		= UVC_GUID_FORMAT_Y800,
+		.fcc		= V4L2_PIX_FMT_GREY,
+	},
+	{
+		.name		= "Greyscale 8-bit (Y8  )",
+		.guid		= UVC_GUID_FORMAT_Y8,
+		.fcc		= V4L2_PIX_FMT_GREY,
+	},
+	{
+		.name		= "Greyscale 10-bit (Y10 )",
+		.guid		= UVC_GUID_FORMAT_Y10,
+		.fcc		= V4L2_PIX_FMT_Y10,
+	},
+	{
+		.name		= "Greyscale 12-bit (Y12 )",
+		.guid		= UVC_GUID_FORMAT_Y12,
+		.fcc		= V4L2_PIX_FMT_Y12,
+	},
+	{
+		.name		= "Greyscale 16-bit (Y16 )",
+		.guid		= UVC_GUID_FORMAT_Y16,
+		.fcc		= V4L2_PIX_FMT_Y16,
+	},
+	{
+		.name		= "BGGR Bayer (BY8 )",
+		.guid		= UVC_GUID_FORMAT_BY8,
+		.fcc		= V4L2_PIX_FMT_SBGGR8,
+	},
+	{
+		.name		= "BGGR Bayer (BA81)",
+		.guid		= UVC_GUID_FORMAT_BA81,
+		.fcc		= V4L2_PIX_FMT_SBGGR8,
+	},
+	{
+		.name		= "GBRG Bayer (GBRG)",
+		.guid		= UVC_GUID_FORMAT_GBRG,
+		.fcc		= V4L2_PIX_FMT_SGBRG8,
+	},
+	{
+		.name		= "GRBG Bayer (GRBG)",
+		.guid		= UVC_GUID_FORMAT_GRBG,
+		.fcc		= V4L2_PIX_FMT_SGRBG8,
+	},
+	{
+		.name		= "RGGB Bayer (RGGB)",
+		.guid		= UVC_GUID_FORMAT_RGGB,
+		.fcc		= V4L2_PIX_FMT_SRGGB8,
+	},
+	{
+		.name		= "RGB565",
+		.guid		= UVC_GUID_FORMAT_RGBP,
+		.fcc		= V4L2_PIX_FMT_RGB565,
+	},
+	{
+		.name		= "BGR 8:8:8 (BGR3)",
+		.guid		= UVC_GUID_FORMAT_BGR3,
+		.fcc		= V4L2_PIX_FMT_BGR24,
+	},
+	{
+		.name		= "H.264",
+		.guid		= UVC_GUID_FORMAT_H264,
+		.fcc		= V4L2_PIX_FMT_H264,
+	},
+};
+
+/* ------------------------------------------------------------------------
+ * Utility functions
+ */
+
+struct usb_host_endpoint *uvc_find_endpoint(struct usb_host_interface *alts,
+		__u8 epaddr)
+{
+	struct usb_host_endpoint *ep;
+	unsigned int i;
+
+	for (i = 0; i < alts->desc.bNumEndpoints; ++i) {
+		ep = &alts->endpoint[i];
+		if (ep->desc.bEndpointAddress == epaddr)
+			return ep;
+	}
+
+	return NULL;
+}
+
+static struct uvc_format_desc *uvc_format_by_guid(const __u8 guid[16])
+{
+	unsigned int len = ARRAY_SIZE(uvc_fmts);
+	unsigned int i;
+
+	for (i = 0; i < len; ++i) {
+		if (memcmp(guid, uvc_fmts[i].guid, 16) == 0)
+			return &uvc_fmts[i];
+	}
+
+	return NULL;
+}
+
+static __u32 uvc_colorspace(const __u8 primaries)
+{
+	static const __u8 colorprimaries[] = {
+		0,
+		V4L2_COLORSPACE_SRGB,
+		V4L2_COLORSPACE_470_SYSTEM_M,
+		V4L2_COLORSPACE_470_SYSTEM_BG,
+		V4L2_COLORSPACE_SMPTE170M,
+		V4L2_COLORSPACE_SMPTE240M,
+	};
+
+	if (primaries < ARRAY_SIZE(colorprimaries))
+		return colorprimaries[primaries];
+
+	return 0;
+}
+
+/* Simplify a fraction using a simple continued fraction decomposition. The
+ * idea here is to convert fractions such as 333333/10000000 to 1/30 using
+ * 32 bit arithmetic only. The algorithm is not perfect and relies upon two
+ * arbitrary parameters to remove non-significative terms from the simple
+ * continued fraction decomposition. Using 8 and 333 for n_terms and threshold
+ * respectively seems to give nice results.
+ */
+void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,
+		unsigned int n_terms, unsigned int threshold)
+{
+	uint32_t *an;
+	uint32_t x, y, r;
+	unsigned int i, n;
+
+	an = kmalloc(n_terms * sizeof *an, GFP_KERNEL);
+	if (an == NULL)
+		return;
+
+	/* Convert the fraction to a simple continued fraction. See
+	 * http://mathforum.org/dr.math/faq/faq.fractions.html
+	 * Stop if the current term is bigger than or equal to the given
+	 * threshold.
+	 */
+	x = *numerator;
+	y = *denominator;
+
+	for (n = 0; n < n_terms && y != 0; ++n) {
+		an[n] = x / y;
+		if (an[n] >= threshold) {
+			if (n < 2)
+				n++;
+			break;
+		}
+
+		r = x - an[n] * y;
+		x = y;
+		y = r;
+	}
+
+	/* Expand the simple continued fraction back to an integer fraction. */
+	x = 0;
+	y = 1;
+
+	for (i = n; i > 0; --i) {
+		r = y;
+		y = an[i-1] * y + x;
+		x = r;
+	}
+
+	*numerator = y;
+	*denominator = x;
+	kfree(an);
+}
+
+/* Convert a fraction to a frame interval in 100ns multiples. The idea here is
+ * to compute numerator / denominator * 10000000 using 32 bit fixed point
+ * arithmetic only.
+ */
+uint32_t uvc_fraction_to_interval(uint32_t numerator, uint32_t denominator)
+{
+	uint32_t multiplier;
+
+	/* Saturate the result if the operation would overflow. */
+	if (denominator == 0 ||
+	    numerator/denominator >= ((uint32_t)-1)/10000000)
+		return (uint32_t)-1;
+
+	/* Divide both the denominator and the multiplier by two until
+	 * numerator * multiplier doesn't overflow. If anyone knows a better
+	 * algorithm please let me know.
+	 */
+	multiplier = 10000000;
+	while (numerator > ((uint32_t)-1)/multiplier) {
+		multiplier /= 2;
+		denominator /= 2;
+	}
+
+	return denominator ? numerator * multiplier / denominator : 0;
+}
+
+/* ------------------------------------------------------------------------
+ * Terminal and unit management
+ */
+
+struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id)
+{
+	struct uvc_entity *entity;
+
+	list_for_each_entry(entity, &dev->entities, list) {
+		if (entity->id == id)
+			return entity;
+	}
+
+	return NULL;
+}
+
+static struct uvc_entity *uvc_entity_by_reference(struct uvc_device *dev,
+	int id, struct uvc_entity *entity)
+{
+	unsigned int i;
+
+	if (entity == NULL)
+		entity = list_entry(&dev->entities, struct uvc_entity, list);
+
+	list_for_each_entry_continue(entity, &dev->entities, list) {
+		for (i = 0; i < entity->bNrInPins; ++i)
+			if (entity->baSourceID[i] == id)
+				return entity;
+	}
+
+	return NULL;
+}
+
+static struct uvc_streaming *uvc_stream_by_id(struct uvc_device *dev, int id)
+{
+	struct uvc_streaming *stream;
+
+	list_for_each_entry(stream, &dev->streams, list) {
+		if (stream->header.bTerminalLink == id)
+			return stream;
+	}
+
+	return NULL;
+}
+
+/* ------------------------------------------------------------------------
+ * Descriptors parsing
+ */
+
+static int uvc_parse_format(struct uvc_device *dev,
+	struct uvc_streaming *streaming, struct uvc_format *format,
+	__u32 **intervals, unsigned char *buffer, int buflen)
+{
+	struct usb_interface *intf = streaming->intf;
+	struct usb_host_interface *alts = intf->cur_altsetting;
+	struct uvc_format_desc *fmtdesc;
+	struct uvc_frame *frame;
+	const unsigned char *start = buffer;
+	unsigned int width_multiplier = 1;
+	unsigned int interval;
+	unsigned int i, n;
+	__u8 ftype;
+
+	format->type = buffer[2];
+	format->index = buffer[3];
+
+	switch (buffer[2]) {
+	case UVC_VS_FORMAT_UNCOMPRESSED:
+	case UVC_VS_FORMAT_FRAME_BASED:
+		n = buffer[2] == UVC_VS_FORMAT_UNCOMPRESSED ? 27 : 28;
+		if (buflen < n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+			       "interface %d FORMAT error\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		/* Find the format descriptor from its GUID. */
+		fmtdesc = uvc_format_by_guid(&buffer[5]);
+
+		if (fmtdesc != NULL) {
+			strlcpy(format->name, fmtdesc->name,
+				sizeof format->name);
+			format->fcc = fmtdesc->fcc;
+		} else {
+			uvc_printk(KERN_INFO, "Unknown video format %pUl\n",
+				&buffer[5]);
+			snprintf(format->name, sizeof(format->name), "%pUl\n",
+				&buffer[5]);
+			format->fcc = 0;
+		}
+
+		format->bpp = buffer[21];
+
+		/* Some devices report a format that doesn't match what they
+		 * really send.
+		 */
+		if (dev->quirks & UVC_QUIRK_FORCE_Y8) {
+			if (format->fcc == V4L2_PIX_FMT_YUYV) {
+				strlcpy(format->name, "Greyscale 8-bit (Y8  )",
+					sizeof(format->name));
+				format->fcc = V4L2_PIX_FMT_GREY;
+				format->bpp = 8;
+				width_multiplier = 2;
+			}
+		}
+
+		if (buffer[2] == UVC_VS_FORMAT_UNCOMPRESSED) {
+			ftype = UVC_VS_FRAME_UNCOMPRESSED;
+		} else {
+			ftype = UVC_VS_FRAME_FRAME_BASED;
+			if (buffer[27])
+				format->flags = UVC_FMT_FLAG_COMPRESSED;
+		}
+		break;
+
+	case UVC_VS_FORMAT_MJPEG:
+		if (buflen < 11) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+			       "interface %d FORMAT error\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		strlcpy(format->name, "MJPEG", sizeof format->name);
+		format->fcc = V4L2_PIX_FMT_MJPEG;
+		format->flags = UVC_FMT_FLAG_COMPRESSED;
+		format->bpp = 0;
+		ftype = UVC_VS_FRAME_MJPEG;
+		break;
+
+	case UVC_VS_FORMAT_DV:
+		if (buflen < 9) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+			       "interface %d FORMAT error\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		switch (buffer[8] & 0x7f) {
+		case 0:
+			strlcpy(format->name, "SD-DV", sizeof format->name);
+			break;
+		case 1:
+			strlcpy(format->name, "SDL-DV", sizeof format->name);
+			break;
+		case 2:
+			strlcpy(format->name, "HD-DV", sizeof format->name);
+			break;
+		default:
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+			       "interface %d: unknown DV format %u\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber, buffer[8]);
+			return -EINVAL;
+		}
+
+		strlcat(format->name, buffer[8] & (1 << 7) ? " 60Hz" : " 50Hz",
+			sizeof format->name);
+
+		format->fcc = V4L2_PIX_FMT_DV;
+		format->flags = UVC_FMT_FLAG_COMPRESSED | UVC_FMT_FLAG_STREAM;
+		format->bpp = 0;
+		ftype = 0;
+
+		/* Create a dummy frame descriptor. */
+		frame = &format->frame[0];
+		memset(&format->frame[0], 0, sizeof format->frame[0]);
+		frame->bFrameIntervalType = 1;
+		frame->dwDefaultFrameInterval = 1;
+		frame->dwFrameInterval = *intervals;
+		*(*intervals)++ = 1;
+		format->nframes = 1;
+		break;
+
+	case UVC_VS_FORMAT_MPEG2TS:
+	case UVC_VS_FORMAT_STREAM_BASED:
+		/* Not supported yet. */
+	default:
+		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+		       "interface %d unsupported format %u\n",
+		       dev->udev->devnum, alts->desc.bInterfaceNumber,
+		       buffer[2]);
+		return -EINVAL;
+	}
+
+	uvc_trace(UVC_TRACE_DESCR, "Found format %s.\n", format->name);
+
+	buflen -= buffer[0];
+	buffer += buffer[0];
+
+	/* Parse the frame descriptors. Only uncompressed, MJPEG and frame
+	 * based formats have frame descriptors.
+	 */
+	while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
+	       buffer[2] == ftype) {
+		frame = &format->frame[format->nframes];
+		if (ftype != UVC_VS_FRAME_FRAME_BASED)
+			n = buflen > 25 ? buffer[25] : 0;
+		else
+			n = buflen > 21 ? buffer[21] : 0;
+
+		n = n ? n : 3;
+
+		if (buflen < 26 + 4*n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+			       "interface %d FRAME error\n", dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		frame->bFrameIndex = buffer[3];
+		frame->bmCapabilities = buffer[4];
+		frame->wWidth = get_unaligned_le16(&buffer[5])
+			      * width_multiplier;
+		frame->wHeight = get_unaligned_le16(&buffer[7]);
+		frame->dwMinBitRate = get_unaligned_le32(&buffer[9]);
+		frame->dwMaxBitRate = get_unaligned_le32(&buffer[13]);
+		if (ftype != UVC_VS_FRAME_FRAME_BASED) {
+			frame->dwMaxVideoFrameBufferSize =
+				get_unaligned_le32(&buffer[17]);
+			frame->dwDefaultFrameInterval =
+				get_unaligned_le32(&buffer[21]);
+			frame->bFrameIntervalType = buffer[25];
+		} else {
+			frame->dwMaxVideoFrameBufferSize = 0;
+			frame->dwDefaultFrameInterval =
+				get_unaligned_le32(&buffer[17]);
+			frame->bFrameIntervalType = buffer[21];
+		}
+		frame->dwFrameInterval = *intervals;
+
+		/* Several UVC chipsets screw up dwMaxVideoFrameBufferSize
+		 * completely. Observed behaviours range from setting the
+		 * value to 1.1x the actual frame size to hardwiring the
+		 * 16 low bits to 0. This results in a higher than necessary
+		 * memory usage as well as a wrong image size information. For
+		 * uncompressed formats this can be fixed by computing the
+		 * value from the frame size.
+		 */
+		if (!(format->flags & UVC_FMT_FLAG_COMPRESSED))
+			frame->dwMaxVideoFrameBufferSize = format->bpp
+				* frame->wWidth * frame->wHeight / 8;
+
+		/* Some bogus devices report dwMinFrameInterval equal to
+		 * dwMaxFrameInterval and have dwFrameIntervalStep set to
+		 * zero. Setting all null intervals to 1 fixes the problem and
+		 * some other divisions by zero that could happen.
+		 */
+		for (i = 0; i < n; ++i) {
+			interval = get_unaligned_le32(&buffer[26+4*i]);
+			*(*intervals)++ = interval ? interval : 1;
+		}
+
+		/* Make sure that the default frame interval stays between
+		 * the boundaries.
+		 */
+		n -= frame->bFrameIntervalType ? 1 : 2;
+		frame->dwDefaultFrameInterval =
+			min(frame->dwFrameInterval[n],
+			    max(frame->dwFrameInterval[0],
+				frame->dwDefaultFrameInterval));
+
+		if (dev->quirks & UVC_QUIRK_RESTRICT_FRAME_RATE) {
+			frame->bFrameIntervalType = 1;
+			frame->dwFrameInterval[0] =
+				frame->dwDefaultFrameInterval;
+		}
+
+		uvc_trace(UVC_TRACE_DESCR, "- %ux%u (%u.%u fps)\n",
+			frame->wWidth, frame->wHeight,
+			10000000/frame->dwDefaultFrameInterval,
+			(100000000/frame->dwDefaultFrameInterval)%10);
+
+		format->nframes++;
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	if (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
+	    buffer[2] == UVC_VS_STILL_IMAGE_FRAME) {
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	if (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
+	    buffer[2] == UVC_VS_COLORFORMAT) {
+		if (buflen < 6) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+			       "interface %d COLORFORMAT error\n",
+			       dev->udev->devnum,
+			       alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		format->colorspace = uvc_colorspace(buffer[3]);
+
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	return buffer - start;
+}
+
+static int uvc_parse_streaming(struct uvc_device *dev,
+	struct usb_interface *intf)
+{
+	struct uvc_streaming *streaming = NULL;
+	struct uvc_format *format;
+	struct uvc_frame *frame;
+	struct usb_host_interface *alts = &intf->altsetting[0];
+	unsigned char *_buffer, *buffer = alts->extra;
+	int _buflen, buflen = alts->extralen;
+	unsigned int nformats = 0, nframes = 0, nintervals = 0;
+	unsigned int size, i, n, p;
+	__u32 *interval;
+	__u16 psize;
+	int ret = -EINVAL;
+
+	if (intf->cur_altsetting->desc.bInterfaceSubClass
+		!= UVC_SC_VIDEOSTREAMING) {
+		uvc_trace(UVC_TRACE_DESCR, "device %d interface %d isn't a "
+			"video streaming interface\n", dev->udev->devnum,
+			intf->altsetting[0].desc.bInterfaceNumber);
+		return -EINVAL;
+	}
+
+	if (usb_driver_claim_interface(&uvc_driver.driver, intf, dev)) {
+		uvc_trace(UVC_TRACE_DESCR, "device %d interface %d is already "
+			"claimed\n", dev->udev->devnum,
+			intf->altsetting[0].desc.bInterfaceNumber);
+		return -EINVAL;
+	}
+
+	streaming = kzalloc(sizeof *streaming, GFP_KERNEL);
+	if (streaming == NULL) {
+		usb_driver_release_interface(&uvc_driver.driver, intf);
+		return -EINVAL;
+	}
+
+	mutex_init(&streaming->mutex);
+	streaming->dev = dev;
+	streaming->intf = usb_get_intf(intf);
+	streaming->intfnum = intf->cur_altsetting->desc.bInterfaceNumber;
+
+	/* The Pico iMage webcam has its class-specific interface descriptors
+	 * after the endpoint descriptors.
+	 */
+	if (buflen == 0) {
+		for (i = 0; i < alts->desc.bNumEndpoints; ++i) {
+			struct usb_host_endpoint *ep = &alts->endpoint[i];
+
+			if (ep->extralen == 0)
+				continue;
+
+			if (ep->extralen > 2 &&
+			    ep->extra[1] == USB_DT_CS_INTERFACE) {
+				uvc_trace(UVC_TRACE_DESCR, "trying extra data "
+					"from endpoint %u.\n", i);
+				buffer = alts->endpoint[i].extra;
+				buflen = alts->endpoint[i].extralen;
+				break;
+			}
+		}
+	}
+
+	/* Skip the standard interface descriptors. */
+	while (buflen > 2 && buffer[1] != USB_DT_CS_INTERFACE) {
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	if (buflen <= 2) {
+		uvc_trace(UVC_TRACE_DESCR, "no class-specific streaming "
+			"interface descriptors found.\n");
+		goto error;
+	}
+
+	/* Parse the header descriptor. */
+	switch (buffer[2]) {
+	case UVC_VS_OUTPUT_HEADER:
+		streaming->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
+		size = 9;
+		break;
+
+	case UVC_VS_INPUT_HEADER:
+		streaming->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+		size = 13;
+		break;
+
+	default:
+		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming interface "
+			"%d HEADER descriptor not found.\n", dev->udev->devnum,
+			alts->desc.bInterfaceNumber);
+		goto error;
+	}
+
+	p = buflen >= 4 ? buffer[3] : 0;
+	n = buflen >= size ? buffer[size-1] : 0;
+
+	if (buflen < size + p*n) {
+		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+			"interface %d HEADER descriptor is invalid.\n",
+			dev->udev->devnum, alts->desc.bInterfaceNumber);
+		goto error;
+	}
+
+	streaming->header.bNumFormats = p;
+	streaming->header.bEndpointAddress = buffer[6];
+	if (buffer[2] == UVC_VS_INPUT_HEADER) {
+		streaming->header.bmInfo = buffer[7];
+		streaming->header.bTerminalLink = buffer[8];
+		streaming->header.bStillCaptureMethod = buffer[9];
+		streaming->header.bTriggerSupport = buffer[10];
+		streaming->header.bTriggerUsage = buffer[11];
+	} else {
+		streaming->header.bTerminalLink = buffer[7];
+	}
+	streaming->header.bControlSize = n;
+
+	streaming->header.bmaControls = kmemdup(&buffer[size], p * n,
+						GFP_KERNEL);
+	if (streaming->header.bmaControls == NULL) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	buflen -= buffer[0];
+	buffer += buffer[0];
+
+	_buffer = buffer;
+	_buflen = buflen;
+
+	/* Count the format and frame descriptors. */
+	while (_buflen > 2 && _buffer[1] == USB_DT_CS_INTERFACE) {
+		switch (_buffer[2]) {
+		case UVC_VS_FORMAT_UNCOMPRESSED:
+		case UVC_VS_FORMAT_MJPEG:
+		case UVC_VS_FORMAT_FRAME_BASED:
+			nformats++;
+			break;
+
+		case UVC_VS_FORMAT_DV:
+			/* DV format has no frame descriptor. We will create a
+			 * dummy frame descriptor with a dummy frame interval.
+			 */
+			nformats++;
+			nframes++;
+			nintervals++;
+			break;
+
+		case UVC_VS_FORMAT_MPEG2TS:
+		case UVC_VS_FORMAT_STREAM_BASED:
+			uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming "
+				"interface %d FORMAT %u is not supported.\n",
+				dev->udev->devnum,
+				alts->desc.bInterfaceNumber, _buffer[2]);
+			break;
+
+		case UVC_VS_FRAME_UNCOMPRESSED:
+		case UVC_VS_FRAME_MJPEG:
+			nframes++;
+			if (_buflen > 25)
+				nintervals += _buffer[25] ? _buffer[25] : 3;
+			break;
+
+		case UVC_VS_FRAME_FRAME_BASED:
+			nframes++;
+			if (_buflen > 21)
+				nintervals += _buffer[21] ? _buffer[21] : 3;
+			break;
+		}
+
+		_buflen -= _buffer[0];
+		_buffer += _buffer[0];
+	}
+
+	if (nformats == 0) {
+		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming interface "
+			"%d has no supported formats defined.\n",
+			dev->udev->devnum, alts->desc.bInterfaceNumber);
+		goto error;
+	}
+
+	size = nformats * sizeof *format + nframes * sizeof *frame
+	     + nintervals * sizeof *interval;
+	format = kzalloc(size, GFP_KERNEL);
+	if (format == NULL) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	frame = (struct uvc_frame *)&format[nformats];
+	interval = (__u32 *)&frame[nframes];
+
+	streaming->format = format;
+	streaming->nformats = nformats;
+
+	/* Parse the format descriptors. */
+	while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE) {
+		switch (buffer[2]) {
+		case UVC_VS_FORMAT_UNCOMPRESSED:
+		case UVC_VS_FORMAT_MJPEG:
+		case UVC_VS_FORMAT_DV:
+		case UVC_VS_FORMAT_FRAME_BASED:
+			format->frame = frame;
+			ret = uvc_parse_format(dev, streaming, format,
+				&interval, buffer, buflen);
+			if (ret < 0)
+				goto error;
+
+			frame += format->nframes;
+			format++;
+
+			buflen -= ret;
+			buffer += ret;
+			continue;
+
+		default:
+			break;
+		}
+
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	if (buflen)
+		uvc_trace(UVC_TRACE_DESCR, "device %d videostreaming interface "
+			"%d has %u bytes of trailing descriptor garbage.\n",
+			dev->udev->devnum, alts->desc.bInterfaceNumber, buflen);
+
+	/* Parse the alternate settings to find the maximum bandwidth. */
+	for (i = 0; i < intf->num_altsetting; ++i) {
+		struct usb_host_endpoint *ep;
+		alts = &intf->altsetting[i];
+		ep = uvc_find_endpoint(alts,
+				streaming->header.bEndpointAddress);
+		if (ep == NULL)
+			continue;
+
+		psize = le16_to_cpu(ep->desc.wMaxPacketSize);
+		psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
+		if (psize > streaming->maxpsize)
+			streaming->maxpsize = psize;
+	}
+
+	list_add_tail(&streaming->list, &dev->streams);
+	return 0;
+
+error:
+	usb_driver_release_interface(&uvc_driver.driver, intf);
+	usb_put_intf(intf);
+	kfree(streaming->format);
+	kfree(streaming->header.bmaControls);
+	kfree(streaming);
+	return ret;
+}
+
+static struct uvc_entity *uvc_alloc_entity(u16 type, u8 id,
+		unsigned int num_pads, unsigned int extra_size)
+{
+	struct uvc_entity *entity;
+	unsigned int num_inputs;
+	unsigned int size;
+	unsigned int i;
+
+	extra_size = ALIGN(extra_size, sizeof(*entity->pads));
+	num_inputs = (type & UVC_TERM_OUTPUT) ? num_pads : num_pads - 1;
+	size = sizeof(*entity) + extra_size + sizeof(*entity->pads) * num_pads
+	     + num_inputs;
+	entity = kzalloc(size, GFP_KERNEL);
+	if (entity == NULL)
+		return NULL;
+
+	entity->id = id;
+	entity->type = type;
+
+	entity->num_links = 0;
+	entity->num_pads = num_pads;
+	entity->pads = ((void *)(entity + 1)) + extra_size;
+
+	for (i = 0; i < num_inputs; ++i)
+		entity->pads[i].flags = MEDIA_PAD_FL_SINK;
+	if (!UVC_ENTITY_IS_OTERM(entity))
+		entity->pads[num_pads-1].flags = MEDIA_PAD_FL_SOURCE;
+
+	entity->bNrInPins = num_inputs;
+	entity->baSourceID = (__u8 *)(&entity->pads[num_pads]);
+
+	return entity;
+}
+
+/* Parse vendor-specific extensions. */
+static int uvc_parse_vendor_control(struct uvc_device *dev,
+	const unsigned char *buffer, int buflen)
+{
+	struct usb_device *udev = dev->udev;
+	struct usb_host_interface *alts = dev->intf->cur_altsetting;
+	struct uvc_entity *unit;
+	unsigned int n, p;
+	int handled = 0;
+
+	switch (le16_to_cpu(dev->udev->descriptor.idVendor)) {
+	case 0x046d:		/* Logitech */
+		if (buffer[1] != 0x41 || buffer[2] != 0x01)
+			break;
+
+		/* Logitech implements several vendor specific functions
+		 * through vendor specific extension units (LXU).
+		 *
+		 * The LXU descriptors are similar to XU descriptors
+		 * (see "USB Device Video Class for Video Devices", section
+		 * 3.7.2.6 "Extension Unit Descriptor") with the following
+		 * differences:
+		 *
+		 * ----------------------------------------------------------
+		 * 0		bLength		1	 Number
+		 *	Size of this descriptor, in bytes: 24+p+n*2
+		 * ----------------------------------------------------------
+		 * 23+p+n	bmControlsType	N	Bitmap
+		 * 	Individual bits in the set are defined:
+		 * 	0: Absolute
+		 * 	1: Relative
+		 *
+		 * 	This bitset is mapped exactly the same as bmControls.
+		 * ----------------------------------------------------------
+		 * 23+p+n*2	bReserved	1	Boolean
+		 * ----------------------------------------------------------
+		 * 24+p+n*2	iExtension	1	Index
+		 *	Index of a string descriptor that describes this
+		 *	extension unit.
+		 * ----------------------------------------------------------
+		 */
+		p = buflen >= 22 ? buffer[21] : 0;
+		n = buflen >= 25 + p ? buffer[22+p] : 0;
+
+		if (buflen < 25 + p + 2*n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d EXTENSION_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			break;
+		}
+
+		unit = uvc_alloc_entity(UVC_VC_EXTENSION_UNIT, buffer[3],
+					p + 1, 2*n);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
+		unit->extension.bNumControls = buffer[20];
+		memcpy(unit->baSourceID, &buffer[22], p);
+		unit->extension.bControlSize = buffer[22+p];
+		unit->extension.bmControls = (__u8 *)unit + sizeof(*unit);
+		unit->extension.bmControlsType = (__u8 *)unit + sizeof(*unit)
+					       + n;
+		memcpy(unit->extension.bmControls, &buffer[23+p], 2*n);
+
+		if (buffer[24+p+2*n] != 0)
+			usb_string(udev, buffer[24+p+2*n], unit->name,
+				   sizeof unit->name);
+		else
+			sprintf(unit->name, "Extension %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		handled = 1;
+		break;
+	}
+
+	return handled;
+}
+
+static int uvc_parse_standard_control(struct uvc_device *dev,
+	const unsigned char *buffer, int buflen)
+{
+	struct usb_device *udev = dev->udev;
+	struct uvc_entity *unit, *term;
+	struct usb_interface *intf;
+	struct usb_host_interface *alts = dev->intf->cur_altsetting;
+	unsigned int i, n, p, len;
+	__u16 type;
+
+	switch (buffer[2]) {
+	case UVC_VC_HEADER:
+		n = buflen >= 12 ? buffer[11] : 0;
+
+		if (buflen < 12 + n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d HEADER error\n", udev->devnum,
+				alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		dev->uvc_version = get_unaligned_le16(&buffer[3]);
+		dev->clock_frequency = get_unaligned_le32(&buffer[7]);
+
+		/* Parse all USB Video Streaming interfaces. */
+		for (i = 0; i < n; ++i) {
+			intf = usb_ifnum_to_if(udev, buffer[12+i]);
+			if (intf == NULL) {
+				uvc_trace(UVC_TRACE_DESCR, "device %d "
+					"interface %d doesn't exists\n",
+					udev->devnum, i);
+				continue;
+			}
+
+			uvc_parse_streaming(dev, intf);
+		}
+		break;
+
+	case UVC_VC_INPUT_TERMINAL:
+		if (buflen < 8) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d INPUT_TERMINAL error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		/* Make sure the terminal type MSB is not null, otherwise it
+		 * could be confused with a unit.
+		 */
+		type = get_unaligned_le16(&buffer[4]);
+		if ((type & 0xff00) == 0) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d INPUT_TERMINAL %d has invalid "
+				"type 0x%04x, skipping\n", udev->devnum,
+				alts->desc.bInterfaceNumber,
+				buffer[3], type);
+			return 0;
+		}
+
+		n = 0;
+		p = 0;
+		len = 8;
+
+		if (type == UVC_ITT_CAMERA) {
+			n = buflen >= 15 ? buffer[14] : 0;
+			len = 15;
+
+		} else if (type == UVC_ITT_MEDIA_TRANSPORT_INPUT) {
+			n = buflen >= 9 ? buffer[8] : 0;
+			p = buflen >= 10 + n ? buffer[9+n] : 0;
+			len = 10;
+		}
+
+		if (buflen < len + n + p) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d INPUT_TERMINAL error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		term = uvc_alloc_entity(type | UVC_TERM_INPUT, buffer[3],
+					1, n + p);
+		if (term == NULL)
+			return -ENOMEM;
+
+		if (UVC_ENTITY_TYPE(term) == UVC_ITT_CAMERA) {
+			term->camera.bControlSize = n;
+			term->camera.bmControls = (__u8 *)term + sizeof *term;
+			term->camera.wObjectiveFocalLengthMin =
+				get_unaligned_le16(&buffer[8]);
+			term->camera.wObjectiveFocalLengthMax =
+				get_unaligned_le16(&buffer[10]);
+			term->camera.wOcularFocalLength =
+				get_unaligned_le16(&buffer[12]);
+			memcpy(term->camera.bmControls, &buffer[15], n);
+		} else if (UVC_ENTITY_TYPE(term) ==
+			   UVC_ITT_MEDIA_TRANSPORT_INPUT) {
+			term->media.bControlSize = n;
+			term->media.bmControls = (__u8 *)term + sizeof *term;
+			term->media.bTransportModeSize = p;
+			term->media.bmTransportModes = (__u8 *)term
+						     + sizeof *term + n;
+			memcpy(term->media.bmControls, &buffer[9], n);
+			memcpy(term->media.bmTransportModes, &buffer[10+n], p);
+		}
+
+		if (buffer[7] != 0)
+			usb_string(udev, buffer[7], term->name,
+				   sizeof term->name);
+		else if (UVC_ENTITY_TYPE(term) == UVC_ITT_CAMERA)
+			sprintf(term->name, "Camera %u", buffer[3]);
+		else if (UVC_ENTITY_TYPE(term) == UVC_ITT_MEDIA_TRANSPORT_INPUT)
+			sprintf(term->name, "Media %u", buffer[3]);
+		else
+			sprintf(term->name, "Input %u", buffer[3]);
+
+		list_add_tail(&term->list, &dev->entities);
+		break;
+
+	case UVC_VC_OUTPUT_TERMINAL:
+		if (buflen < 9) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d OUTPUT_TERMINAL error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		/* Make sure the terminal type MSB is not null, otherwise it
+		 * could be confused with a unit.
+		 */
+		type = get_unaligned_le16(&buffer[4]);
+		if ((type & 0xff00) == 0) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d OUTPUT_TERMINAL %d has invalid "
+				"type 0x%04x, skipping\n", udev->devnum,
+				alts->desc.bInterfaceNumber, buffer[3], type);
+			return 0;
+		}
+
+		term = uvc_alloc_entity(type | UVC_TERM_OUTPUT, buffer[3],
+					1, 0);
+		if (term == NULL)
+			return -ENOMEM;
+
+		memcpy(term->baSourceID, &buffer[7], 1);
+
+		if (buffer[8] != 0)
+			usb_string(udev, buffer[8], term->name,
+				   sizeof term->name);
+		else
+			sprintf(term->name, "Output %u", buffer[3]);
+
+		list_add_tail(&term->list, &dev->entities);
+		break;
+
+	case UVC_VC_SELECTOR_UNIT:
+		p = buflen >= 5 ? buffer[4] : 0;
+
+		if (buflen < 5 || buflen < 6 + p) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d SELECTOR_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		unit = uvc_alloc_entity(buffer[2], buffer[3], p + 1, 0);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		memcpy(unit->baSourceID, &buffer[5], p);
+
+		if (buffer[5+p] != 0)
+			usb_string(udev, buffer[5+p], unit->name,
+				   sizeof unit->name);
+		else
+			sprintf(unit->name, "Selector %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		break;
+
+	case UVC_VC_PROCESSING_UNIT:
+		n = buflen >= 8 ? buffer[7] : 0;
+		p = dev->uvc_version >= 0x0110 ? 10 : 9;
+
+		if (buflen < p + n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d PROCESSING_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		unit = uvc_alloc_entity(buffer[2], buffer[3], 2, n);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		memcpy(unit->baSourceID, &buffer[4], 1);
+		unit->processing.wMaxMultiplier =
+			get_unaligned_le16(&buffer[5]);
+		unit->processing.bControlSize = buffer[7];
+		unit->processing.bmControls = (__u8 *)unit + sizeof *unit;
+		memcpy(unit->processing.bmControls, &buffer[8], n);
+		if (dev->uvc_version >= 0x0110)
+			unit->processing.bmVideoStandards = buffer[9+n];
+
+		if (buffer[8+n] != 0)
+			usb_string(udev, buffer[8+n], unit->name,
+				   sizeof unit->name);
+		else
+			sprintf(unit->name, "Processing %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		break;
+
+	case UVC_VC_EXTENSION_UNIT:
+		p = buflen >= 22 ? buffer[21] : 0;
+		n = buflen >= 24 + p ? buffer[22+p] : 0;
+
+		if (buflen < 24 + p + n) {
+			uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+				"interface %d EXTENSION_UNIT error\n",
+				udev->devnum, alts->desc.bInterfaceNumber);
+			return -EINVAL;
+		}
+
+		unit = uvc_alloc_entity(buffer[2], buffer[3], p + 1, n);
+		if (unit == NULL)
+			return -ENOMEM;
+
+		memcpy(unit->extension.guidExtensionCode, &buffer[4], 16);
+		unit->extension.bNumControls = buffer[20];
+		memcpy(unit->baSourceID, &buffer[22], p);
+		unit->extension.bControlSize = buffer[22+p];
+		unit->extension.bmControls = (__u8 *)unit + sizeof *unit;
+		memcpy(unit->extension.bmControls, &buffer[23+p], n);
+
+		if (buffer[23+p+n] != 0)
+			usb_string(udev, buffer[23+p+n], unit->name,
+				   sizeof unit->name);
+		else
+			sprintf(unit->name, "Extension %u", buffer[3]);
+
+		list_add_tail(&unit->list, &dev->entities);
+		break;
+
+	default:
+		uvc_trace(UVC_TRACE_DESCR, "Found an unknown CS_INTERFACE "
+			"descriptor (%u)\n", buffer[2]);
+		break;
+	}
+
+	return 0;
+}
+
+static int uvc_parse_control(struct uvc_device *dev)
+{
+	struct usb_host_interface *alts = dev->intf->cur_altsetting;
+	unsigned char *buffer = alts->extra;
+	int buflen = alts->extralen;
+	int ret;
+
+	/* Parse the default alternate setting only, as the UVC specification
+	 * defines a single alternate setting, the default alternate setting
+	 * zero.
+	 */
+
+	while (buflen > 2) {
+		if (uvc_parse_vendor_control(dev, buffer, buflen) ||
+		    buffer[1] != USB_DT_CS_INTERFACE)
+			goto next_descriptor;
+
+		if ((ret = uvc_parse_standard_control(dev, buffer, buflen)) < 0)
+			return ret;
+
+next_descriptor:
+		buflen -= buffer[0];
+		buffer += buffer[0];
+	}
+
+	/* Check if the optional status endpoint is present. Built-in iSight
+	 * webcams have an interrupt endpoint but spit proprietary data that
+	 * don't conform to the UVC status endpoint messages. Don't try to
+	 * handle the interrupt endpoint for those cameras.
+	 */
+	if (alts->desc.bNumEndpoints == 1 &&
+	    !(dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)) {
+		struct usb_host_endpoint *ep = &alts->endpoint[0];
+		struct usb_endpoint_descriptor *desc = &ep->desc;
+
+		if (usb_endpoint_is_int_in(desc) &&
+		    le16_to_cpu(desc->wMaxPacketSize) >= 8 &&
+		    desc->bInterval != 0) {
+			uvc_trace(UVC_TRACE_DESCR, "Found a Status endpoint "
+				"(addr %02x).\n", desc->bEndpointAddress);
+			dev->int_ep = ep;
+		}
+	}
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * UVC device scan
+ */
+
+/*
+ * Scan the UVC descriptors to locate a chain starting at an Output Terminal
+ * and containing the following units:
+ *
+ * - one or more Output Terminals (USB Streaming or Display)
+ * - zero or one Processing Unit
+ * - zero, one or more single-input Selector Units
+ * - zero or one multiple-input Selector Units, provided all inputs are
+ *   connected to input terminals
+ * - zero, one or mode single-input Extension Units
+ * - one or more Input Terminals (Camera, External or USB Streaming)
+ *
+ * The terminal and units must match on of the following structures:
+ *
+ * ITT_*(0) -> +---------+    +---------+    +---------+ -> TT_STREAMING(0)
+ * ...         | SU{0,1} | -> | PU{0,1} | -> | XU{0,n} |    ...
+ * ITT_*(n) -> +---------+    +---------+    +---------+ -> TT_STREAMING(n)
+ *
+ *                 +---------+    +---------+ -> OTT_*(0)
+ * TT_STREAMING -> | PU{0,1} | -> | XU{0,n} |    ...
+ *                 +---------+    +---------+ -> OTT_*(n)
+ *
+ * The Processing Unit and Extension Units can be in any order. Additional
+ * Extension Units connected to the main chain as single-unit branches are
+ * also supported. Single-input Selector Units are ignored.
+ */
+static int uvc_scan_chain_entity(struct uvc_video_chain *chain,
+	struct uvc_entity *entity)
+{
+	switch (UVC_ENTITY_TYPE(entity)) {
+	case UVC_VC_EXTENSION_UNIT:
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- XU %d", entity->id);
+
+		if (entity->bNrInPins != 1) {
+			uvc_trace(UVC_TRACE_DESCR, "Extension unit %d has more "
+				"than 1 input pin.\n", entity->id);
+			return -1;
+		}
+
+		break;
+
+	case UVC_VC_PROCESSING_UNIT:
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- PU %d", entity->id);
+
+		if (chain->processing != NULL) {
+			uvc_trace(UVC_TRACE_DESCR, "Found multiple "
+				"Processing Units in chain.\n");
+			return -1;
+		}
+
+		chain->processing = entity;
+		break;
+
+	case UVC_VC_SELECTOR_UNIT:
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- SU %d", entity->id);
+
+		/* Single-input selector units are ignored. */
+		if (entity->bNrInPins == 1)
+			break;
+
+		if (chain->selector != NULL) {
+			uvc_trace(UVC_TRACE_DESCR, "Found multiple Selector "
+				"Units in chain.\n");
+			return -1;
+		}
+
+		chain->selector = entity;
+		break;
+
+	case UVC_ITT_VENDOR_SPECIFIC:
+	case UVC_ITT_CAMERA:
+	case UVC_ITT_MEDIA_TRANSPORT_INPUT:
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- IT %d\n", entity->id);
+
+		break;
+
+	case UVC_OTT_VENDOR_SPECIFIC:
+	case UVC_OTT_DISPLAY:
+	case UVC_OTT_MEDIA_TRANSPORT_OUTPUT:
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" OT %d", entity->id);
+
+		break;
+
+	case UVC_TT_STREAMING:
+		if (UVC_ENTITY_IS_ITERM(entity)) {
+			if (uvc_trace_param & UVC_TRACE_PROBE)
+				printk(" <- IT %d\n", entity->id);
+		} else {
+			if (uvc_trace_param & UVC_TRACE_PROBE)
+				printk(" OT %d", entity->id);
+		}
+
+		break;
+
+	default:
+		uvc_trace(UVC_TRACE_DESCR, "Unsupported entity type "
+			"0x%04x found in chain.\n", UVC_ENTITY_TYPE(entity));
+		return -1;
+	}
+
+	list_add_tail(&entity->chain, &chain->entities);
+	return 0;
+}
+
+static int uvc_scan_chain_forward(struct uvc_video_chain *chain,
+	struct uvc_entity *entity, struct uvc_entity *prev)
+{
+	struct uvc_entity *forward;
+	int found;
+
+	/* Forward scan */
+	forward = NULL;
+	found = 0;
+
+	while (1) {
+		forward = uvc_entity_by_reference(chain->dev, entity->id,
+			forward);
+		if (forward == NULL)
+			break;
+		if (forward == prev)
+			continue;
+
+		switch (UVC_ENTITY_TYPE(forward)) {
+		case UVC_VC_EXTENSION_UNIT:
+			if (forward->bNrInPins != 1) {
+				uvc_trace(UVC_TRACE_DESCR, "Extension unit %d "
+					  "has more than 1 input pin.\n",
+					  entity->id);
+				return -EINVAL;
+			}
+
+			list_add_tail(&forward->chain, &chain->entities);
+			if (uvc_trace_param & UVC_TRACE_PROBE) {
+				if (!found)
+					printk(" (->");
+
+				printk(" XU %d", forward->id);
+				found = 1;
+			}
+			break;
+
+		case UVC_OTT_VENDOR_SPECIFIC:
+		case UVC_OTT_DISPLAY:
+		case UVC_OTT_MEDIA_TRANSPORT_OUTPUT:
+		case UVC_TT_STREAMING:
+			if (UVC_ENTITY_IS_ITERM(forward)) {
+				uvc_trace(UVC_TRACE_DESCR, "Unsupported input "
+					"terminal %u.\n", forward->id);
+				return -EINVAL;
+			}
+
+			list_add_tail(&forward->chain, &chain->entities);
+			if (uvc_trace_param & UVC_TRACE_PROBE) {
+				if (!found)
+					printk(" (->");
+
+				printk(" OT %d", forward->id);
+				found = 1;
+			}
+			break;
+		}
+	}
+	if (found)
+		printk(")");
+
+	return 0;
+}
+
+static int uvc_scan_chain_backward(struct uvc_video_chain *chain,
+	struct uvc_entity **_entity)
+{
+	struct uvc_entity *entity = *_entity;
+	struct uvc_entity *term;
+	int id = -EINVAL, i;
+
+	switch (UVC_ENTITY_TYPE(entity)) {
+	case UVC_VC_EXTENSION_UNIT:
+	case UVC_VC_PROCESSING_UNIT:
+		id = entity->baSourceID[0];
+		break;
+
+	case UVC_VC_SELECTOR_UNIT:
+		/* Single-input selector units are ignored. */
+		if (entity->bNrInPins == 1) {
+			id = entity->baSourceID[0];
+			break;
+		}
+
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk(" <- IT");
+
+		chain->selector = entity;
+		for (i = 0; i < entity->bNrInPins; ++i) {
+			id = entity->baSourceID[i];
+			term = uvc_entity_by_id(chain->dev, id);
+			if (term == NULL || !UVC_ENTITY_IS_ITERM(term)) {
+				uvc_trace(UVC_TRACE_DESCR, "Selector unit %d "
+					"input %d isn't connected to an "
+					"input terminal\n", entity->id, i);
+				return -1;
+			}
+
+			if (uvc_trace_param & UVC_TRACE_PROBE)
+				printk(" %d", term->id);
+
+			list_add_tail(&term->chain, &chain->entities);
+			uvc_scan_chain_forward(chain, term, entity);
+		}
+
+		if (uvc_trace_param & UVC_TRACE_PROBE)
+			printk("\n");
+
+		id = 0;
+		break;
+
+	case UVC_ITT_VENDOR_SPECIFIC:
+	case UVC_ITT_CAMERA:
+	case UVC_ITT_MEDIA_TRANSPORT_INPUT:
+	case UVC_OTT_VENDOR_SPECIFIC:
+	case UVC_OTT_DISPLAY:
+	case UVC_OTT_MEDIA_TRANSPORT_OUTPUT:
+	case UVC_TT_STREAMING:
+		id = UVC_ENTITY_IS_OTERM(entity) ? entity->baSourceID[0] : 0;
+		break;
+	}
+
+	if (id <= 0) {
+		*_entity = NULL;
+		return id;
+	}
+
+	entity = uvc_entity_by_id(chain->dev, id);
+	if (entity == NULL) {
+		uvc_trace(UVC_TRACE_DESCR, "Found reference to "
+			"unknown entity %d.\n", id);
+		return -EINVAL;
+	}
+
+	*_entity = entity;
+	return 0;
+}
+
+static int uvc_scan_chain(struct uvc_video_chain *chain,
+			  struct uvc_entity *term)
+{
+	struct uvc_entity *entity, *prev;
+
+	uvc_trace(UVC_TRACE_PROBE, "Scanning UVC chain:");
+
+	entity = term;
+	prev = NULL;
+
+	while (entity != NULL) {
+		/* Entity must not be part of an existing chain */
+		if (entity->chain.next || entity->chain.prev) {
+			uvc_trace(UVC_TRACE_DESCR, "Found reference to "
+				"entity %d already in chain.\n", entity->id);
+			return -EINVAL;
+		}
+
+		/* Process entity */
+		if (uvc_scan_chain_entity(chain, entity) < 0)
+			return -EINVAL;
+
+		/* Forward scan */
+		if (uvc_scan_chain_forward(chain, entity, prev) < 0)
+			return -EINVAL;
+
+		/* Backward scan */
+		prev = entity;
+		if (uvc_scan_chain_backward(chain, &entity) < 0)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static unsigned int uvc_print_terms(struct list_head *terms, u16 dir,
+		char *buffer)
+{
+	struct uvc_entity *term;
+	unsigned int nterms = 0;
+	char *p = buffer;
+
+	list_for_each_entry(term, terms, chain) {
+		if (!UVC_ENTITY_IS_TERM(term) ||
+		    UVC_TERM_DIRECTION(term) != dir)
+			continue;
+
+		if (nterms)
+			p += sprintf(p, ",");
+		if (++nterms >= 4) {
+			p += sprintf(p, "...");
+			break;
+		}
+		p += sprintf(p, "%u", term->id);
+	}
+
+	return p - buffer;
+}
+
+static const char *uvc_print_chain(struct uvc_video_chain *chain)
+{
+	static char buffer[43];
+	char *p = buffer;
+
+	p += uvc_print_terms(&chain->entities, UVC_TERM_INPUT, p);
+	p += sprintf(p, " -> ");
+	uvc_print_terms(&chain->entities, UVC_TERM_OUTPUT, p);
+
+	return buffer;
+}
+
+/*
+ * Scan the device for video chains and register video devices.
+ *
+ * Chains are scanned starting at their output terminals and walked backwards.
+ */
+static int uvc_scan_device(struct uvc_device *dev)
+{
+	struct uvc_video_chain *chain;
+	struct uvc_entity *term;
+
+	list_for_each_entry(term, &dev->entities, list) {
+		if (!UVC_ENTITY_IS_OTERM(term))
+			continue;
+
+		/* If the terminal is already included in a chain, skip it.
+		 * This can happen for chains that have multiple output
+		 * terminals, where all output terminals beside the first one
+		 * will be inserted in the chain in forward scans.
+		 */
+		if (term->chain.next || term->chain.prev)
+			continue;
+
+		chain = kzalloc(sizeof(*chain), GFP_KERNEL);
+		if (chain == NULL)
+			return -ENOMEM;
+
+		INIT_LIST_HEAD(&chain->entities);
+		mutex_init(&chain->ctrl_mutex);
+		chain->dev = dev;
+		v4l2_prio_init(&chain->prio);
+
+		term->flags |= UVC_ENTITY_FLAG_DEFAULT;
+
+		if (uvc_scan_chain(chain, term) < 0) {
+			kfree(chain);
+			continue;
+		}
+
+		uvc_trace(UVC_TRACE_PROBE, "Found a valid video chain (%s).\n",
+			  uvc_print_chain(chain));
+
+		list_add_tail(&chain->list, &dev->chains);
+	}
+
+	if (list_empty(&dev->chains)) {
+		uvc_printk(KERN_INFO, "No valid video chain found.\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * Video device registration and unregistration
+ */
+
+/*
+ * Delete the UVC device.
+ *
+ * Called by the kernel when the last reference to the uvc_device structure
+ * is released.
+ *
+ * As this function is called after or during disconnect(), all URBs have
+ * already been canceled by the USB core. There is no need to kill the
+ * interrupt URB manually.
+ */
+static void uvc_delete(struct uvc_device *dev)
+{
+	struct list_head *p, *n;
+
+	uvc_status_cleanup(dev);
+	uvc_ctrl_cleanup_device(dev);
+
+	usb_put_intf(dev->intf);
+	usb_put_dev(dev->udev);
+
+	if (dev->vdev.dev)
+		v4l2_device_unregister(&dev->vdev);
+#ifdef CONFIG_MEDIA_CONTROLLER
+	if (media_devnode_is_registered(&dev->mdev.devnode))
+		media_device_unregister(&dev->mdev);
+#endif
+
+	list_for_each_safe(p, n, &dev->chains) {
+		struct uvc_video_chain *chain;
+		chain = list_entry(p, struct uvc_video_chain, list);
+		kfree(chain);
+	}
+
+	list_for_each_safe(p, n, &dev->entities) {
+		struct uvc_entity *entity;
+		entity = list_entry(p, struct uvc_entity, list);
+#ifdef CONFIG_MEDIA_CONTROLLER
+		uvc_mc_cleanup_entity(entity);
+#endif
+		kfree(entity);
+	}
+
+	list_for_each_safe(p, n, &dev->streams) {
+		struct uvc_streaming *streaming;
+		streaming = list_entry(p, struct uvc_streaming, list);
+		usb_driver_release_interface(&uvc_driver.driver,
+			streaming->intf);
+		usb_put_intf(streaming->intf);
+		kfree(streaming->format);
+		kfree(streaming->header.bmaControls);
+		kfree(streaming);
+	}
+
+	kfree(dev);
+}
+
+static void uvc_release(struct video_device *vdev)
+{
+	struct uvc_streaming *stream = video_get_drvdata(vdev);
+	struct uvc_device *dev = stream->dev;
+
+	/* Decrement the registered streams count and delete the device when it
+	 * reaches zero.
+	 */
+	if (atomic_dec_and_test(&dev->nstreams))
+		uvc_delete(dev);
+}
+
+/*
+ * Unregister the video devices.
+ */
+static void uvc_unregister_video(struct uvc_device *dev)
+{
+	struct uvc_streaming *stream;
+
+	/* Unregistering all video devices might result in uvc_delete() being
+	 * called from inside the loop if there's no open file handle. To avoid
+	 * that, increment the stream count before iterating over the streams
+	 * and decrement it when done.
+	 */
+	atomic_inc(&dev->nstreams);
+
+	list_for_each_entry(stream, &dev->streams, list) {
+		if (!video_is_registered(&stream->vdev))
+			continue;
+
+		video_unregister_device(&stream->vdev);
+
+		uvc_debugfs_cleanup_stream(stream);
+	}
+
+	/* Decrement the stream count and call uvc_delete explicitly if there
+	 * are no stream left.
+	 */
+	if (atomic_dec_and_test(&dev->nstreams))
+		uvc_delete(dev);
+}
+
+static int uvc_register_video(struct uvc_device *dev,
+		struct uvc_streaming *stream)
+{
+	struct video_device *vdev = &stream->vdev;
+	int ret;
+
+	/* Initialize the video buffers queue. */
+	ret = uvc_queue_init(&stream->queue, stream->type, !uvc_no_drop_param);
+	if (ret)
+		return ret;
+
+	/* Initialize the streaming interface with default streaming
+	 * parameters.
+	 */
+	ret = uvc_video_init(stream);
+	if (ret < 0) {
+		uvc_printk(KERN_ERR, "Failed to initialize the device "
+			"(%d).\n", ret);
+		return ret;
+	}
+
+	uvc_debugfs_init_stream(stream);
+
+	/* Register the device with V4L. */
+
+	/* We already hold a reference to dev->udev. The video device will be
+	 * unregistered before the reference is released, so we don't need to
+	 * get another one.
+	 */
+	vdev->v4l2_dev = &dev->vdev;
+	vdev->fops = &uvc_fops;
+	vdev->ioctl_ops = &uvc_ioctl_ops;
+	vdev->release = uvc_release;
+	vdev->prio = &stream->chain->prio;
+	if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
+		vdev->vfl_dir = VFL_DIR_TX;
+	strlcpy(vdev->name, dev->name, sizeof vdev->name);
+
+	/* Set the driver data before calling video_register_device, otherwise
+	 * uvc_v4l2_open might race us.
+	 */
+	video_set_drvdata(vdev, stream);
+
+	ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
+	if (ret < 0) {
+		uvc_printk(KERN_ERR, "Failed to register video device (%d).\n",
+			   ret);
+		return ret;
+	}
+
+	if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		stream->chain->caps |= V4L2_CAP_VIDEO_CAPTURE;
+	else
+		stream->chain->caps |= V4L2_CAP_VIDEO_OUTPUT;
+
+	atomic_inc(&dev->nstreams);
+	return 0;
+}
+
+/*
+ * Register all video devices in all chains.
+ */
+static int uvc_register_terms(struct uvc_device *dev,
+	struct uvc_video_chain *chain)
+{
+	struct uvc_streaming *stream;
+	struct uvc_entity *term;
+	int ret;
+
+	list_for_each_entry(term, &chain->entities, chain) {
+		if (UVC_ENTITY_TYPE(term) != UVC_TT_STREAMING)
+			continue;
+
+		stream = uvc_stream_by_id(dev, term->id);
+		if (stream == NULL) {
+			uvc_printk(KERN_INFO, "No streaming interface found "
+				   "for terminal %u.", term->id);
+			continue;
+		}
+
+		stream->chain = chain;
+		ret = uvc_register_video(dev, stream);
+		if (ret < 0)
+			return ret;
+
+		term->vdev = &stream->vdev;
+	}
+
+	return 0;
+}
+
+static int uvc_register_chains(struct uvc_device *dev)
+{
+	struct uvc_video_chain *chain;
+	int ret;
+
+	list_for_each_entry(chain, &dev->chains, list) {
+		ret = uvc_register_terms(dev, chain);
+		if (ret < 0)
+			return ret;
+
+#ifdef CONFIG_MEDIA_CONTROLLER
+		ret = uvc_mc_register_entities(chain);
+		if (ret < 0) {
+			uvc_printk(KERN_INFO, "Failed to register entites "
+				"(%d).\n", ret);
+		}
+#endif
+	}
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * USB probe, disconnect, suspend and resume
+ */
+
+static int uvc_probe(struct usb_interface *intf,
+		     const struct usb_device_id *id)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct uvc_device *dev;
+	int ret;
+
+	if (id->idVendor && id->idProduct)
+		uvc_trace(UVC_TRACE_PROBE, "Probing known UVC device %s "
+				"(%04x:%04x)\n", udev->devpath, id->idVendor,
+				id->idProduct);
+	else
+		uvc_trace(UVC_TRACE_PROBE, "Probing generic UVC device %s\n",
+				udev->devpath);
+
+	/* Allocate memory for the device and initialize it. */
+	if ((dev = kzalloc(sizeof *dev, GFP_KERNEL)) == NULL)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&dev->entities);
+	INIT_LIST_HEAD(&dev->chains);
+	INIT_LIST_HEAD(&dev->streams);
+	atomic_set(&dev->nstreams, 0);
+	atomic_set(&dev->nmappings, 0);
+	mutex_init(&dev->lock);
+
+	dev->udev = usb_get_dev(udev);
+	dev->intf = usb_get_intf(intf);
+	dev->intfnum = intf->cur_altsetting->desc.bInterfaceNumber;
+	dev->quirks = (uvc_quirks_param == -1)
+		    ? id->driver_info : uvc_quirks_param;
+
+	if (udev->product != NULL)
+		strlcpy(dev->name, udev->product, sizeof dev->name);
+	else
+		snprintf(dev->name, sizeof dev->name,
+			"UVC Camera (%04x:%04x)",
+			le16_to_cpu(udev->descriptor.idVendor),
+			le16_to_cpu(udev->descriptor.idProduct));
+
+	/* Parse the Video Class control descriptor. */
+	if (uvc_parse_control(dev) < 0) {
+		uvc_trace(UVC_TRACE_PROBE, "Unable to parse UVC "
+			"descriptors.\n");
+		goto error;
+	}
+
+	uvc_printk(KERN_INFO, "Found UVC %u.%02x device %s (%04x:%04x)\n",
+		dev->uvc_version >> 8, dev->uvc_version & 0xff,
+		udev->product ? udev->product : "<unnamed>",
+		le16_to_cpu(udev->descriptor.idVendor),
+		le16_to_cpu(udev->descriptor.idProduct));
+
+	if (dev->quirks != id->driver_info) {
+		uvc_printk(KERN_INFO, "Forcing device quirks to 0x%x by module "
+			"parameter for testing purpose.\n", dev->quirks);
+		uvc_printk(KERN_INFO, "Please report required quirks to the "
+			"linux-uvc-devel mailing list.\n");
+	}
+
+	/* Register the media and V4L2 devices. */
+#ifdef CONFIG_MEDIA_CONTROLLER
+	dev->mdev.dev = &intf->dev;
+	strlcpy(dev->mdev.model, dev->name, sizeof(dev->mdev.model));
+	if (udev->serial)
+		strlcpy(dev->mdev.serial, udev->serial,
+			sizeof(dev->mdev.serial));
+	strcpy(dev->mdev.bus_info, udev->devpath);
+	dev->mdev.hw_revision = le16_to_cpu(udev->descriptor.bcdDevice);
+	dev->mdev.driver_version = LINUX_VERSION_CODE;
+	if (media_device_register(&dev->mdev) < 0)
+		goto error;
+
+	dev->vdev.mdev = &dev->mdev;
+#endif
+	if (v4l2_device_register(&intf->dev, &dev->vdev) < 0)
+		goto error;
+
+	/* Initialize controls. */
+	if (uvc_ctrl_init_device(dev) < 0)
+		goto error;
+
+	/* Scan the device for video chains. */
+	if (uvc_scan_device(dev) < 0)
+		goto error;
+
+	/* Register video device nodes. */
+	if (uvc_register_chains(dev) < 0)
+		goto error;
+
+	/* Save our data pointer in the interface data. */
+	usb_set_intfdata(intf, dev);
+
+	/* Initialize the interrupt URB. */
+	if ((ret = uvc_status_init(dev)) < 0) {
+		uvc_printk(KERN_INFO, "Unable to initialize the status "
+			"endpoint (%d), status interrupt will not be "
+			"supported.\n", ret);
+	}
+
+	uvc_trace(UVC_TRACE_PROBE, "UVC device initialized.\n");
+	usb_enable_autosuspend(udev);
+	return 0;
+
+error:
+	uvc_unregister_video(dev);
+	return -ENODEV;
+}
+
+static void uvc_disconnect(struct usb_interface *intf)
+{
+	struct uvc_device *dev = usb_get_intfdata(intf);
+
+	/* Set the USB interface data to NULL. This can be done outside the
+	 * lock, as there's no other reader.
+	 */
+	usb_set_intfdata(intf, NULL);
+
+	if (intf->cur_altsetting->desc.bInterfaceSubClass ==
+	    UVC_SC_VIDEOSTREAMING)
+		return;
+
+	dev->state |= UVC_DEV_DISCONNECTED;
+
+	uvc_unregister_video(dev);
+}
+
+static int uvc_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct uvc_device *dev = usb_get_intfdata(intf);
+	struct uvc_streaming *stream;
+
+	uvc_trace(UVC_TRACE_SUSPEND, "Suspending interface %u\n",
+		intf->cur_altsetting->desc.bInterfaceNumber);
+
+	/* Controls are cached on the fly so they don't need to be saved. */
+	if (intf->cur_altsetting->desc.bInterfaceSubClass ==
+	    UVC_SC_VIDEOCONTROL) {
+		mutex_lock(&dev->lock);
+		if (dev->users)
+			uvc_status_stop(dev);
+		mutex_unlock(&dev->lock);
+		return 0;
+	}
+
+	list_for_each_entry(stream, &dev->streams, list) {
+		if (stream->intf == intf)
+			return uvc_video_suspend(stream);
+	}
+
+	uvc_trace(UVC_TRACE_SUSPEND, "Suspend: video streaming USB interface "
+			"mismatch.\n");
+	return -EINVAL;
+}
+
+static int __uvc_resume(struct usb_interface *intf, int reset)
+{
+	struct uvc_device *dev = usb_get_intfdata(intf);
+	struct uvc_streaming *stream;
+	int ret = 0;
+
+	uvc_trace(UVC_TRACE_SUSPEND, "Resuming interface %u\n",
+		intf->cur_altsetting->desc.bInterfaceNumber);
+
+	if (intf->cur_altsetting->desc.bInterfaceSubClass ==
+	    UVC_SC_VIDEOCONTROL) {
+		if (reset) {
+			ret = uvc_ctrl_restore_values(dev);
+			if (ret < 0)
+				return ret;
+		}
+
+		mutex_lock(&dev->lock);
+		if (dev->users)
+			ret = uvc_status_start(dev, GFP_NOIO);
+		mutex_unlock(&dev->lock);
+
+		return ret;
+	}
+
+	list_for_each_entry(stream, &dev->streams, list) {
+		if (stream->intf == intf) {
+			ret = uvc_video_resume(stream, reset);
+			if (ret < 0)
+				uvc_queue_streamoff(&stream->queue,
+						    stream->queue.queue.type);
+			return ret;
+		}
+	}
+
+	uvc_trace(UVC_TRACE_SUSPEND, "Resume: video streaming USB interface "
+			"mismatch.\n");
+	return -EINVAL;
+}
+
+static int uvc_resume(struct usb_interface *intf)
+{
+	return __uvc_resume(intf, 0);
+}
+
+static int uvc_reset_resume(struct usb_interface *intf)
+{
+	return __uvc_resume(intf, 1);
+}
+
+/* ------------------------------------------------------------------------
+ * Module parameters
+ */
+
+static int uvc_clock_param_get(char *buffer, struct kernel_param *kp)
+{
+	if (uvc_clock_param == CLOCK_MONOTONIC)
+		return sprintf(buffer, "CLOCK_MONOTONIC");
+	else
+		return sprintf(buffer, "CLOCK_REALTIME");
+}
+
+static int uvc_clock_param_set(const char *val, struct kernel_param *kp)
+{
+	if (strncasecmp(val, "clock_", strlen("clock_")) == 0)
+		val += strlen("clock_");
+
+	if (strcasecmp(val, "monotonic") == 0)
+		uvc_clock_param = CLOCK_MONOTONIC;
+	else if (strcasecmp(val, "realtime") == 0)
+		uvc_clock_param = CLOCK_REALTIME;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+module_param_call(clock, uvc_clock_param_set, uvc_clock_param_get,
+		  &uvc_clock_param, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(clock, "Video buffers timestamp clock");
+module_param_named(nodrop, uvc_no_drop_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(nodrop, "Don't drop incomplete frames");
+module_param_named(quirks, uvc_quirks_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(quirks, "Forced device quirks");
+module_param_named(trace, uvc_trace_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(trace, "Trace level bitmask");
+module_param_named(timeout, uvc_timeout_param, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(timeout, "Streaming control requests timeout");
+
+/* ------------------------------------------------------------------------
+ * Driver initialization and cleanup
+ */
+
+/*
+ * The Logitech cameras listed below have their interface class set to
+ * VENDOR_SPEC because they don't announce themselves as UVC devices, even
+ * though they are compliant.
+ */
+static struct usb_device_id uvc_ids[] = {
+	/* LogiLink Wireless Webcam */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0416,
+	  .idProduct		= 0xa91a,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Genius eFace 2025 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0458,
+	  .idProduct		= 0x706e,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Microsoft Lifecam NX-6000 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x045e,
+	  .idProduct		= 0x00f8,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Microsoft Lifecam NX-3000 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x045e,
+	  .idProduct		= 0x0721,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_DEF },
+	/* Microsoft Lifecam VX-7000 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x045e,
+	  .idProduct		= 0x0723,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Logitech Quickcam Fusion */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c1,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam Orbit MP */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c2,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam Pro for Notebook */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c3,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam Pro 5000 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c5,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam OEM Dell Notebook */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c6,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech Quickcam OEM Cisco VT Camera II */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x08c7,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Logitech HD Pro Webcam C920 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x046d,
+	  .idProduct		= 0x082d,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_RESTORE_CTRLS_ON_INIT },
+	/* Chicony CNF7129 (Asus EEE 100HE) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x04f2,
+	  .idProduct		= 0xb071,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_RESTRICT_FRAME_RATE },
+	/* Alcor Micro AU3820 (Future Boy PC USB Webcam) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x058f,
+	  .idProduct		= 0x3820,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Dell XPS m1530 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x2640,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info 		= UVC_QUIRK_PROBE_DEF },
+	/* Dell SP2008WFP Monitor */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x2641,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info 		= UVC_QUIRK_PROBE_DEF },
+	/* Dell Alienware X51 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x2643,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info	= UVC_QUIRK_PROBE_DEF },
+	/* Dell Studio Hybrid 140g (OmniVision webcam) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x264a,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_DEF },
+	/* Dell XPS M1330 (OmniVision OV7670 webcam) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05a9,
+	  .idProduct		= 0x7670,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_DEF },
+	/* Apple Built-In iSight */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05ac,
+	  .idProduct		= 0x8501,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info 		= UVC_QUIRK_PROBE_MINMAX
+				| UVC_QUIRK_BUILTIN_ISIGHT },
+	/* Foxlink ("HP Webcam" on HP Mini 5103) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05c8,
+	  .idProduct		= 0x0403,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_FIX_BANDWIDTH },
+	/* Genesys Logic USB 2.0 PC Camera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x05e3,
+	  .idProduct		= 0x0505,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Hercules Classic Silver */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x06f8,
+	  .idProduct		= 0x300c,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_FIX_BANDWIDTH },
+	/* ViMicro Vega */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0ac8,
+	  .idProduct		= 0x332d,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_FIX_BANDWIDTH },
+	/* ViMicro - Minoru3D */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0ac8,
+	  .idProduct		= 0x3410,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_FIX_BANDWIDTH },
+	/* ViMicro Venus - Minoru3D */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0ac8,
+	  .idProduct		= 0x3420,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_FIX_BANDWIDTH },
+	/* Ophir Optronics - SPCAM 620U */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0bd3,
+	  .idProduct		= 0x0555,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* MT6227 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x0e8d,
+	  .idProduct		= 0x0004,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX
+				| UVC_QUIRK_PROBE_DEF },
+	/* IMC Networks (Medion Akoya) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x13d3,
+	  .idProduct		= 0x5103,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* JMicron USB2.0 XGA WebCam */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x152d,
+	  .idProduct		= 0x0310,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Syntek (HP Spartan) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x5212,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Syntek (Samsung Q310) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x5931,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Syntek (Packard Bell EasyNote MX52 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x8a12,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Syntek (Asus F9SG) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x8a31,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Syntek (Asus U3S) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x8a33,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Syntek (JAOtech Smart Terminal) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x174f,
+	  .idProduct		= 0x8a34,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Miricle 307K */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x17dc,
+	  .idProduct		= 0x0202,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Lenovo Thinkpad SL400/SL500 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x17ef,
+	  .idProduct		= 0x480b,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STREAM_NO_FID },
+	/* Aveo Technology USB 2.0 Camera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1871,
+	  .idProduct		= 0x0306,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX
+				| UVC_QUIRK_PROBE_EXTRAFIELDS },
+	/* Aveo Technology USB 2.0 Camera (Tasco USB Microscope) */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1871,
+	  .idProduct		= 0x0516,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Ecamm Pico iMage */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x18cd,
+	  .idProduct		= 0xcafe,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_EXTRAFIELDS },
+	/* Manta MM-353 Plako */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x18ec,
+	  .idProduct		= 0x3188,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* FSC WebCam V30S */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x18ec,
+	  .idProduct		= 0x3288,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* Arkmicro unbranded */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x18ec,
+	  .idProduct		= 0x3290,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_DEF },
+	/* The Imaging Source USB CCD cameras */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x199e,
+	  .idProduct		= 0x8102,
+	  .bInterfaceClass	= USB_CLASS_VENDOR_SPEC,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0 },
+	/* Bodelin ProScopeHR */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_DEV_HI
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x19ab,
+	  .idProduct		= 0x1000,
+	  .bcdDevice_hi		= 0x0126,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_STATUS_INTERVAL },
+	/* MSI StarCam 370i */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1b3b,
+	  .idProduct		= 0x2951,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX },
+	/* SiGma Micro USB Web Camera */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x1c4f,
+	  .idProduct		= 0x3000,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_PROBE_MINMAX
+				| UVC_QUIRK_IGNORE_SELECTOR_UNIT },
+	/* Oculus VR Positional Tracker DK2 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x2833,
+	  .idProduct		= 0x0201,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_FORCE_Y8 },
+	/* Generic USB Video Class */
+	{ USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, 0) },
+	{}
+};
+
+MODULE_DEVICE_TABLE(usb, uvc_ids);
+
+struct uvc_driver uvc_driver = {
+	.driver = {
+		.name		= "uvcvideo",
+		.probe		= uvc_probe,
+		.disconnect	= uvc_disconnect,
+		.suspend	= uvc_suspend,
+		.resume		= uvc_resume,
+		.reset_resume	= uvc_reset_resume,
+		.id_table	= uvc_ids,
+		.supports_autosuspend = 1,
+	},
+};
+
+static int __init uvc_init(void)
+{
+	int ret;
+
+	uvc_debugfs_init();
+
+	ret = usb_register(&uvc_driver.driver);
+	if (ret < 0) {
+		uvc_debugfs_cleanup();
+		return ret;
+	}
+
+	printk(KERN_INFO DRIVER_DESC " (" DRIVER_VERSION ")\n");
+	return 0;
+}
+
+static void __exit uvc_cleanup(void)
+{
+	usb_deregister(&uvc_driver.driver);
+	uvc_debugfs_cleanup();
+}
+
+module_init(uvc_init);
+module_exit(uvc_cleanup);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
+
diff --git a/kernel/drivers/media/usb/uvc/uvc_entity.c b/kernel/drivers/media/usb/uvc/uvc_entity.c
new file mode 100644
index 000000000..dc56a59ec
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_entity.c
@@ -0,0 +1,128 @@
+/*
+ *      uvc_entity.c  --  USB Video Class driver
+ *
+ *      Copyright (C) 2005-2011
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/videodev2.h>
+
+#include <media/v4l2-common.h>
+
+#include "uvcvideo.h"
+
+/* ------------------------------------------------------------------------
+ * Video subdevices registration and unregistration
+ */
+
+static int uvc_mc_register_entity(struct uvc_video_chain *chain,
+	struct uvc_entity *entity)
+{
+	const u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
+	struct media_entity *sink;
+	unsigned int i;
+	int ret;
+
+	sink = (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
+	     ? (entity->vdev ? &entity->vdev->entity : NULL)
+	     : &entity->subdev.entity;
+	if (sink == NULL)
+		return 0;
+
+	for (i = 0; i < entity->num_pads; ++i) {
+		struct media_entity *source;
+		struct uvc_entity *remote;
+		u8 remote_pad;
+
+		if (!(entity->pads[i].flags & MEDIA_PAD_FL_SINK))
+			continue;
+
+		remote = uvc_entity_by_id(chain->dev, entity->baSourceID[i]);
+		if (remote == NULL)
+			return -EINVAL;
+
+		source = (UVC_ENTITY_TYPE(remote) == UVC_TT_STREAMING)
+		       ? (remote->vdev ? &remote->vdev->entity : NULL)
+		       : &remote->subdev.entity;
+		if (source == NULL)
+			continue;
+
+		remote_pad = remote->num_pads - 1;
+		ret = media_entity_create_link(source, remote_pad,
+					       sink, i, flags);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
+		return 0;
+
+	return v4l2_device_register_subdev(&chain->dev->vdev, &entity->subdev);
+}
+
+static struct v4l2_subdev_ops uvc_subdev_ops = {
+};
+
+void uvc_mc_cleanup_entity(struct uvc_entity *entity)
+{
+	if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING)
+		media_entity_cleanup(&entity->subdev.entity);
+	else if (entity->vdev != NULL)
+		media_entity_cleanup(&entity->vdev->entity);
+}
+
+static int uvc_mc_init_entity(struct uvc_entity *entity)
+{
+	int ret;
+
+	if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING) {
+		v4l2_subdev_init(&entity->subdev, &uvc_subdev_ops);
+		strlcpy(entity->subdev.name, entity->name,
+			sizeof(entity->subdev.name));
+
+		ret = media_entity_init(&entity->subdev.entity,
+					entity->num_pads, entity->pads, 0);
+	} else if (entity->vdev != NULL) {
+		ret = media_entity_init(&entity->vdev->entity,
+					entity->num_pads, entity->pads, 0);
+		if (entity->flags & UVC_ENTITY_FLAG_DEFAULT)
+			entity->vdev->entity.flags |= MEDIA_ENT_FL_DEFAULT;
+	} else
+		ret = 0;
+
+	return ret;
+}
+
+int uvc_mc_register_entities(struct uvc_video_chain *chain)
+{
+	struct uvc_entity *entity;
+	int ret;
+
+	list_for_each_entry(entity, &chain->entities, chain) {
+		ret = uvc_mc_init_entity(entity);
+		if (ret < 0) {
+			uvc_printk(KERN_INFO, "Failed to initialize entity for "
+				   "entity %u\n", entity->id);
+			return ret;
+		}
+	}
+
+	list_for_each_entry(entity, &chain->entities, chain) {
+		ret = uvc_mc_register_entity(chain, entity);
+		if (ret < 0) {
+			uvc_printk(KERN_INFO, "Failed to register entity for "
+				   "entity %u\n", entity->id);
+			return ret;
+		}
+	}
+
+	return 0;
+}
diff --git a/kernel/drivers/media/usb/uvc/uvc_isight.c b/kernel/drivers/media/usb/uvc/uvc_isight.c
new file mode 100644
index 000000000..8510e7259
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_isight.c
@@ -0,0 +1,137 @@
+/*
+ *      uvc_isight.c  --  USB Video Class driver - iSight support
+ *
+ *	Copyright (C) 2006-2007
+ *		Ivan N. Zlatev <contact@i-nz.net>
+ *	Copyright (C) 2008-2009
+ *		Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/usb.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+
+#include "uvcvideo.h"
+
+/* Built-in iSight webcams implements most of UVC 1.0 except a
+ * different packet format. Instead of sending a header at the
+ * beginning of each isochronous transfer payload, the webcam sends a
+ * single header per image (on its own in a packet), followed by
+ * packets containing data only.
+ *
+ * Offset   Size (bytes)	Description
+ * ------------------------------------------------------------------
+ * 0x00 	1   	Header length
+ * 0x01 	1   	Flags (UVC-compliant)
+ * 0x02 	4   	Always equal to '11223344'
+ * 0x06 	8   	Always equal to 'deadbeefdeadface'
+ * 0x0e 	16  	Unknown
+ *
+ * The header can be prefixed by an optional, unknown-purpose byte.
+ */
+
+static int isight_decode(struct uvc_video_queue *queue, struct uvc_buffer *buf,
+		const __u8 *data, unsigned int len)
+{
+	static const __u8 hdr[] = {
+		0x11, 0x22, 0x33, 0x44,
+		0xde, 0xad, 0xbe, 0xef,
+		0xde, 0xad, 0xfa, 0xce
+	};
+
+	unsigned int maxlen, nbytes;
+	__u8 *mem;
+	int is_header = 0;
+
+	if (buf == NULL)
+		return 0;
+
+	if ((len >= 14 && memcmp(&data[2], hdr, 12) == 0) ||
+	    (len >= 15 && memcmp(&data[3], hdr, 12) == 0)) {
+		uvc_trace(UVC_TRACE_FRAME, "iSight header found\n");
+		is_header = 1;
+	}
+
+	/* Synchronize to the input stream by waiting for a header packet. */
+	if (buf->state != UVC_BUF_STATE_ACTIVE) {
+		if (!is_header) {
+			uvc_trace(UVC_TRACE_FRAME, "Dropping packet (out of "
+				  "sync).\n");
+			return 0;
+		}
+
+		buf->state = UVC_BUF_STATE_ACTIVE;
+	}
+
+	/* Mark the buffer as done if we're at the beginning of a new frame.
+	 *
+	 * Empty buffers (bytesused == 0) don't trigger end of frame detection
+	 * as it doesn't make sense to return an empty buffer.
+	 */
+	if (is_header && buf->bytesused != 0) {
+		buf->state = UVC_BUF_STATE_DONE;
+		return -EAGAIN;
+	}
+
+	/* Copy the video data to the buffer. Skip header packets, as they
+	 * contain no data.
+	 */
+	if (!is_header) {
+		maxlen = buf->length - buf->bytesused;
+		mem = buf->mem + buf->bytesused;
+		nbytes = min(len, maxlen);
+		memcpy(mem, data, nbytes);
+		buf->bytesused += nbytes;
+
+		if (len > maxlen || buf->bytesused == buf->length) {
+			uvc_trace(UVC_TRACE_FRAME, "Frame complete "
+				  "(overflow).\n");
+			buf->state = UVC_BUF_STATE_DONE;
+		}
+	}
+
+	return 0;
+}
+
+void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream,
+		struct uvc_buffer *buf)
+{
+	int ret, i;
+
+	for (i = 0; i < urb->number_of_packets; ++i) {
+		if (urb->iso_frame_desc[i].status < 0) {
+			uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
+				  "lost (%d).\n",
+				  urb->iso_frame_desc[i].status);
+		}
+
+		/* Decode the payload packet.
+		 * uvc_video_decode is entered twice when a frame transition
+		 * has been detected because the end of frame can only be
+		 * reliably detected when the first packet of the new frame
+		 * is processed. The first pass detects the transition and
+		 * closes the previous frame's buffer, the second pass
+		 * processes the data of the first payload of the new frame.
+		 */
+		do {
+			ret = isight_decode(&stream->queue, buf,
+					urb->transfer_buffer +
+					urb->iso_frame_desc[i].offset,
+					urb->iso_frame_desc[i].actual_length);
+
+			if (buf == NULL)
+				break;
+
+			if (buf->state == UVC_BUF_STATE_DONE ||
+			    buf->state == UVC_BUF_STATE_ERROR)
+				buf = uvc_queue_next_buffer(&stream->queue,
+							buf);
+		} while (ret == -EAGAIN);
+	}
+}
diff --git a/kernel/drivers/media/usb/uvc/uvc_queue.c b/kernel/drivers/media/usb/uvc/uvc_queue.c
new file mode 100644
index 000000000..87a19f33e
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_queue.c
@@ -0,0 +1,407 @@
+/*
+ *      uvc_queue.c  --  USB Video Class driver - Buffers management
+ *
+ *      Copyright (C) 2005-2010
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/atomic.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <media/videobuf2-vmalloc.h>
+
+#include "uvcvideo.h"
+
+/* ------------------------------------------------------------------------
+ * Video buffers queue management.
+ *
+ * Video queues is initialized by uvc_queue_init(). The function performs
+ * basic initialization of the uvc_video_queue struct and never fails.
+ *
+ * Video buffers are managed by videobuf2. The driver uses a mutex to protect
+ * the videobuf2 queue operations by serializing calls to videobuf2 and a
+ * spinlock to protect the IRQ queue that holds the buffers to be processed by
+ * the driver.
+ */
+
+static inline struct uvc_streaming *
+uvc_queue_to_stream(struct uvc_video_queue *queue)
+{
+	return container_of(queue, struct uvc_streaming, queue);
+}
+
+/*
+ * Return all queued buffers to videobuf2 in the requested state.
+ *
+ * This function must be called with the queue spinlock held.
+ */
+static void uvc_queue_return_buffers(struct uvc_video_queue *queue,
+			       enum uvc_buffer_state state)
+{
+	enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR
+					? VB2_BUF_STATE_ERROR
+					: VB2_BUF_STATE_QUEUED;
+
+	while (!list_empty(&queue->irqqueue)) {
+		struct uvc_buffer *buf = list_first_entry(&queue->irqqueue,
+							  struct uvc_buffer,
+							  queue);
+		list_del(&buf->queue);
+		buf->state = state;
+		vb2_buffer_done(&buf->buf, vb2_state);
+	}
+}
+
+/* -----------------------------------------------------------------------------
+ * videobuf2 queue operations
+ */
+
+static int uvc_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
+			   unsigned int *nbuffers, unsigned int *nplanes,
+			   unsigned int sizes[], void *alloc_ctxs[])
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+
+	/* Make sure the image size is large enough. */
+	if (fmt && fmt->fmt.pix.sizeimage < stream->ctrl.dwMaxVideoFrameSize)
+		return -EINVAL;
+
+	*nplanes = 1;
+
+	sizes[0] = fmt ? fmt->fmt.pix.sizeimage
+		 : stream->ctrl.dwMaxVideoFrameSize;
+
+	return 0;
+}
+
+static int uvc_buffer_prepare(struct vb2_buffer *vb)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+	struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
+
+	if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
+	    vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) {
+		uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n");
+		return -EINVAL;
+	}
+
+	if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED))
+		return -ENODEV;
+
+	buf->state = UVC_BUF_STATE_QUEUED;
+	buf->error = 0;
+	buf->mem = vb2_plane_vaddr(vb, 0);
+	buf->length = vb2_plane_size(vb, 0);
+	if (vb->v4l2_buf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		buf->bytesused = 0;
+	else
+		buf->bytesused = vb2_get_plane_payload(vb, 0);
+
+	return 0;
+}
+
+static void uvc_buffer_queue(struct vb2_buffer *vb)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+	struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+	if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) {
+		list_add_tail(&buf->queue, &queue->irqqueue);
+	} else {
+		/* If the device is disconnected return the buffer to userspace
+		 * directly. The next QBUF call will fail with -ENODEV.
+		 */
+		buf->state = UVC_BUF_STATE_ERROR;
+		vb2_buffer_done(&buf->buf, VB2_BUF_STATE_ERROR);
+	}
+
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+static void uvc_buffer_finish(struct vb2_buffer *vb)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
+	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+	struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
+
+	if (vb->state == VB2_BUF_STATE_DONE)
+		uvc_video_clock_update(stream, &vb->v4l2_buf, buf);
+}
+
+static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+	unsigned long flags;
+	int ret;
+
+	queue->buf_used = 0;
+
+	ret = uvc_video_enable(stream, 1);
+	if (ret == 0)
+		return 0;
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+	uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED);
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+
+	return ret;
+}
+
+static void uvc_stop_streaming(struct vb2_queue *vq)
+{
+	struct uvc_video_queue *queue = vb2_get_drv_priv(vq);
+	struct uvc_streaming *stream = uvc_queue_to_stream(queue);
+	unsigned long flags;
+
+	uvc_video_enable(stream, 0);
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+static struct vb2_ops uvc_queue_qops = {
+	.queue_setup = uvc_queue_setup,
+	.buf_prepare = uvc_buffer_prepare,
+	.buf_queue = uvc_buffer_queue,
+	.buf_finish = uvc_buffer_finish,
+	.wait_prepare = vb2_ops_wait_prepare,
+	.wait_finish = vb2_ops_wait_finish,
+	.start_streaming = uvc_start_streaming,
+	.stop_streaming = uvc_stop_streaming,
+};
+
+int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
+		    int drop_corrupted)
+{
+	int ret;
+
+	queue->queue.type = type;
+	queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
+	queue->queue.drv_priv = queue;
+	queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
+	queue->queue.ops = &uvc_queue_qops;
+	queue->queue.mem_ops = &vb2_vmalloc_memops;
+	queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
+		| V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
+	queue->queue.lock = &queue->mutex;
+	ret = vb2_queue_init(&queue->queue);
+	if (ret)
+		return ret;
+
+	mutex_init(&queue->mutex);
+	spin_lock_init(&queue->irqlock);
+	INIT_LIST_HEAD(&queue->irqqueue);
+	queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0;
+
+	return 0;
+}
+
+void uvc_queue_release(struct uvc_video_queue *queue)
+{
+	mutex_lock(&queue->mutex);
+	vb2_queue_release(&queue->queue);
+	mutex_unlock(&queue->mutex);
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 queue operations
+ */
+
+int uvc_request_buffers(struct uvc_video_queue *queue,
+			struct v4l2_requestbuffers *rb)
+{
+	int ret;
+
+	mutex_lock(&queue->mutex);
+	ret = vb2_reqbufs(&queue->queue, rb);
+	mutex_unlock(&queue->mutex);
+
+	return ret ? ret : rb->count;
+}
+
+int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
+{
+	int ret;
+
+	mutex_lock(&queue->mutex);
+	ret = vb2_querybuf(&queue->queue, buf);
+	mutex_unlock(&queue->mutex);
+
+	return ret;
+}
+
+int uvc_create_buffers(struct uvc_video_queue *queue,
+		       struct v4l2_create_buffers *cb)
+{
+	int ret;
+
+	mutex_lock(&queue->mutex);
+	ret = vb2_create_bufs(&queue->queue, cb);
+	mutex_unlock(&queue->mutex);
+
+	return ret;
+}
+
+int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
+{
+	int ret;
+
+	mutex_lock(&queue->mutex);
+	ret = vb2_qbuf(&queue->queue, buf);
+	mutex_unlock(&queue->mutex);
+
+	return ret;
+}
+
+int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf,
+		       int nonblocking)
+{
+	int ret;
+
+	mutex_lock(&queue->mutex);
+	ret = vb2_dqbuf(&queue->queue, buf, nonblocking);
+	mutex_unlock(&queue->mutex);
+
+	return ret;
+}
+
+int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type)
+{
+	int ret;
+
+	mutex_lock(&queue->mutex);
+	ret = vb2_streamon(&queue->queue, type);
+	mutex_unlock(&queue->mutex);
+
+	return ret;
+}
+
+int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type)
+{
+	int ret;
+
+	mutex_lock(&queue->mutex);
+	ret = vb2_streamoff(&queue->queue, type);
+	mutex_unlock(&queue->mutex);
+
+	return ret;
+}
+
+int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma)
+{
+	return vb2_mmap(&queue->queue, vma);
+}
+
+#ifndef CONFIG_MMU
+unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+		unsigned long pgoff)
+{
+	return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0);
+}
+#endif
+
+unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file,
+			    poll_table *wait)
+{
+	unsigned int ret;
+
+	mutex_lock(&queue->mutex);
+	ret = vb2_poll(&queue->queue, file, wait);
+	mutex_unlock(&queue->mutex);
+
+	return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ *
+ */
+
+/*
+ * Check if buffers have been allocated.
+ */
+int uvc_queue_allocated(struct uvc_video_queue *queue)
+{
+	int allocated;
+
+	mutex_lock(&queue->mutex);
+	allocated = vb2_is_busy(&queue->queue);
+	mutex_unlock(&queue->mutex);
+
+	return allocated;
+}
+
+/*
+ * Cancel the video buffers queue.
+ *
+ * Cancelling the queue marks all buffers on the irq queue as erroneous,
+ * wakes them up and removes them from the queue.
+ *
+ * If the disconnect parameter is set, further calls to uvc_queue_buffer will
+ * fail with -ENODEV.
+ *
+ * This function acquires the irq spinlock and can be called from interrupt
+ * context.
+ */
+void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+	uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR);
+	/* This must be protected by the irqlock spinlock to avoid race
+	 * conditions between uvc_buffer_queue and the disconnection event that
+	 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
+	 * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
+	 * state outside the queue code.
+	 */
+	if (disconnect)
+		queue->flags |= UVC_QUEUE_DISCONNECTED;
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+}
+
+struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
+		struct uvc_buffer *buf)
+{
+	struct uvc_buffer *nextbuf;
+	unsigned long flags;
+
+	if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
+		buf->error = 0;
+		buf->state = UVC_BUF_STATE_QUEUED;
+		buf->bytesused = 0;
+		vb2_set_plane_payload(&buf->buf, 0, 0);
+		return buf;
+	}
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+	list_del(&buf->queue);
+	if (!list_empty(&queue->irqqueue))
+		nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+					   queue);
+	else
+		nextbuf = NULL;
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+
+	buf->state = buf->error ? VB2_BUF_STATE_ERROR : UVC_BUF_STATE_DONE;
+	vb2_set_plane_payload(&buf->buf, 0, buf->bytesused);
+	vb2_buffer_done(&buf->buf, VB2_BUF_STATE_DONE);
+
+	return nextbuf;
+}
diff --git a/kernel/drivers/media/usb/uvc/uvc_status.c b/kernel/drivers/media/usb/uvc/uvc_status.c
new file mode 100644
index 000000000..f552ab997
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_status.c
@@ -0,0 +1,220 @@
+/*
+ *      uvc_status.c  --  USB Video Class driver - Status endpoint
+ *
+ *      Copyright (C) 2005-2009
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/usb/input.h>
+
+#include "uvcvideo.h"
+
+/* --------------------------------------------------------------------------
+ * Input device
+ */
+#ifdef CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV
+static int uvc_input_init(struct uvc_device *dev)
+{
+	struct input_dev *input;
+	int ret;
+
+	input = input_allocate_device();
+	if (input == NULL)
+		return -ENOMEM;
+
+	usb_make_path(dev->udev, dev->input_phys, sizeof(dev->input_phys));
+	strlcat(dev->input_phys, "/button", sizeof(dev->input_phys));
+
+	input->name = dev->name;
+	input->phys = dev->input_phys;
+	usb_to_input_id(dev->udev, &input->id);
+	input->dev.parent = &dev->intf->dev;
+
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(KEY_CAMERA, input->keybit);
+
+	if ((ret = input_register_device(input)) < 0)
+		goto error;
+
+	dev->input = input;
+	return 0;
+
+error:
+	input_free_device(input);
+	return ret;
+}
+
+static void uvc_input_cleanup(struct uvc_device *dev)
+{
+	if (dev->input)
+		input_unregister_device(dev->input);
+}
+
+static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
+	int value)
+{
+	if (dev->input) {
+		input_report_key(dev->input, code, value);
+		input_sync(dev->input);
+	}
+}
+
+#else
+#define uvc_input_init(dev)
+#define uvc_input_cleanup(dev)
+#define uvc_input_report_key(dev, code, value)
+#endif /* CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV */
+
+/* --------------------------------------------------------------------------
+ * Status interrupt endpoint
+ */
+static void uvc_event_streaming(struct uvc_device *dev, __u8 *data, int len)
+{
+	if (len < 3) {
+		uvc_trace(UVC_TRACE_STATUS, "Invalid streaming status event "
+				"received.\n");
+		return;
+	}
+
+	if (data[2] == 0) {
+		if (len < 4)
+			return;
+		uvc_trace(UVC_TRACE_STATUS, "Button (intf %u) %s len %d\n",
+			data[1], data[3] ? "pressed" : "released", len);
+		uvc_input_report_key(dev, KEY_CAMERA, data[3]);
+	} else {
+		uvc_trace(UVC_TRACE_STATUS, "Stream %u error event %02x %02x "
+			"len %d.\n", data[1], data[2], data[3], len);
+	}
+}
+
+static void uvc_event_control(struct uvc_device *dev, __u8 *data, int len)
+{
+	char *attrs[3] = { "value", "info", "failure" };
+
+	if (len < 6 || data[2] != 0 || data[4] > 2) {
+		uvc_trace(UVC_TRACE_STATUS, "Invalid control status event "
+				"received.\n");
+		return;
+	}
+
+	uvc_trace(UVC_TRACE_STATUS, "Control %u/%u %s change len %d.\n",
+		data[1], data[3], attrs[data[4]], len);
+}
+
+static void uvc_status_complete(struct urb *urb)
+{
+	struct uvc_device *dev = urb->context;
+	int len, ret;
+
+	switch (urb->status) {
+	case 0:
+		break;
+
+	case -ENOENT:		/* usb_kill_urb() called. */
+	case -ECONNRESET:	/* usb_unlink_urb() called. */
+	case -ESHUTDOWN:	/* The endpoint is being disabled. */
+	case -EPROTO:		/* Device is disconnected (reported by some
+				 * host controller). */
+		return;
+
+	default:
+		uvc_printk(KERN_WARNING, "Non-zero status (%d) in status "
+			"completion handler.\n", urb->status);
+		return;
+	}
+
+	len = urb->actual_length;
+	if (len > 0) {
+		switch (dev->status[0] & 0x0f) {
+		case UVC_STATUS_TYPE_CONTROL:
+			uvc_event_control(dev, dev->status, len);
+			break;
+
+		case UVC_STATUS_TYPE_STREAMING:
+			uvc_event_streaming(dev, dev->status, len);
+			break;
+
+		default:
+			uvc_trace(UVC_TRACE_STATUS, "Unknown status event "
+				"type %u.\n", dev->status[0]);
+			break;
+		}
+	}
+
+	/* Resubmit the URB. */
+	urb->interval = dev->int_ep->desc.bInterval;
+	if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
+		uvc_printk(KERN_ERR, "Failed to resubmit status URB (%d).\n",
+			ret);
+	}
+}
+
+int uvc_status_init(struct uvc_device *dev)
+{
+	struct usb_host_endpoint *ep = dev->int_ep;
+	unsigned int pipe;
+	int interval;
+
+	if (ep == NULL)
+		return 0;
+
+	uvc_input_init(dev);
+
+	dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL);
+	if (dev->status == NULL)
+		return -ENOMEM;
+
+	dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (dev->int_urb == NULL) {
+		kfree(dev->status);
+		return -ENOMEM;
+	}
+
+	pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
+
+	/* For high-speed interrupt endpoints, the bInterval value is used as
+	 * an exponent of two. Some developers forgot about it.
+	 */
+	interval = ep->desc.bInterval;
+	if (interval > 16 && dev->udev->speed == USB_SPEED_HIGH &&
+	    (dev->quirks & UVC_QUIRK_STATUS_INTERVAL))
+		interval = fls(interval) - 1;
+
+	usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
+		dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete,
+		dev, interval);
+
+	return 0;
+}
+
+void uvc_status_cleanup(struct uvc_device *dev)
+{
+	usb_kill_urb(dev->int_urb);
+	usb_free_urb(dev->int_urb);
+	kfree(dev->status);
+	uvc_input_cleanup(dev);
+}
+
+int uvc_status_start(struct uvc_device *dev, gfp_t flags)
+{
+	if (dev->int_urb == NULL)
+		return 0;
+
+	return usb_submit_urb(dev->int_urb, flags);
+}
+
+void uvc_status_stop(struct uvc_device *dev)
+{
+	usb_kill_urb(dev->int_urb);
+}
diff --git a/kernel/drivers/media/usb/uvc/uvc_v4l2.c b/kernel/drivers/media/usb/uvc/uvc_v4l2.c
new file mode 100644
index 000000000..c4b1ac675
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_v4l2.c
@@ -0,0 +1,1521 @@
+/*
+ *      uvc_v4l2.c  --  USB Video Class driver - V4L2 API
+ *
+ *      Copyright (C) 2005-2010
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/compat.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/wait.h>
+#include <linux/atomic.h>
+
+#include <media/v4l2-common.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-ioctl.h>
+
+#include "uvcvideo.h"
+
+/* ------------------------------------------------------------------------
+ * UVC ioctls
+ */
+static int uvc_ioctl_ctrl_map(struct uvc_video_chain *chain,
+	struct uvc_xu_control_mapping *xmap)
+{
+	struct uvc_control_mapping *map;
+	unsigned int size;
+	int ret;
+
+	map = kzalloc(sizeof *map, GFP_KERNEL);
+	if (map == NULL)
+		return -ENOMEM;
+
+	map->id = xmap->id;
+	memcpy(map->name, xmap->name, sizeof map->name);
+	memcpy(map->entity, xmap->entity, sizeof map->entity);
+	map->selector = xmap->selector;
+	map->size = xmap->size;
+	map->offset = xmap->offset;
+	map->v4l2_type = xmap->v4l2_type;
+	map->data_type = xmap->data_type;
+
+	switch (xmap->v4l2_type) {
+	case V4L2_CTRL_TYPE_INTEGER:
+	case V4L2_CTRL_TYPE_BOOLEAN:
+	case V4L2_CTRL_TYPE_BUTTON:
+		break;
+
+	case V4L2_CTRL_TYPE_MENU:
+		/* Prevent excessive memory consumption, as well as integer
+		 * overflows.
+		 */
+		if (xmap->menu_count == 0 ||
+		    xmap->menu_count > UVC_MAX_CONTROL_MENU_ENTRIES) {
+			ret = -EINVAL;
+			goto done;
+		}
+
+		size = xmap->menu_count * sizeof(*map->menu_info);
+		map->menu_info = kmalloc(size, GFP_KERNEL);
+		if (map->menu_info == NULL) {
+			ret = -ENOMEM;
+			goto done;
+		}
+
+		if (copy_from_user(map->menu_info, xmap->menu_info, size)) {
+			ret = -EFAULT;
+			goto done;
+		}
+
+		map->menu_count = xmap->menu_count;
+		break;
+
+	default:
+		uvc_trace(UVC_TRACE_CONTROL, "Unsupported V4L2 control type "
+			  "%u.\n", xmap->v4l2_type);
+		ret = -ENOTTY;
+		goto done;
+	}
+
+	ret = uvc_ctrl_add_mapping(chain, map);
+
+done:
+	kfree(map->menu_info);
+	kfree(map);
+
+	return ret;
+}
+
+/* ------------------------------------------------------------------------
+ * V4L2 interface
+ */
+
+/*
+ * Find the frame interval closest to the requested frame interval for the
+ * given frame format and size. This should be done by the device as part of
+ * the Video Probe and Commit negotiation, but some hardware don't implement
+ * that feature.
+ */
+static __u32 uvc_try_frame_interval(struct uvc_frame *frame, __u32 interval)
+{
+	unsigned int i;
+
+	if (frame->bFrameIntervalType) {
+		__u32 best = -1, dist;
+
+		for (i = 0; i < frame->bFrameIntervalType; ++i) {
+			dist = interval > frame->dwFrameInterval[i]
+			     ? interval - frame->dwFrameInterval[i]
+			     : frame->dwFrameInterval[i] - interval;
+
+			if (dist > best)
+				break;
+
+			best = dist;
+		}
+
+		interval = frame->dwFrameInterval[i-1];
+	} else {
+		const __u32 min = frame->dwFrameInterval[0];
+		const __u32 max = frame->dwFrameInterval[1];
+		const __u32 step = frame->dwFrameInterval[2];
+
+		interval = min + (interval - min + step/2) / step * step;
+		if (interval > max)
+			interval = max;
+	}
+
+	return interval;
+}
+
+static int uvc_v4l2_try_format(struct uvc_streaming *stream,
+	struct v4l2_format *fmt, struct uvc_streaming_control *probe,
+	struct uvc_format **uvc_format, struct uvc_frame **uvc_frame)
+{
+	struct uvc_format *format = NULL;
+	struct uvc_frame *frame = NULL;
+	__u16 rw, rh;
+	unsigned int d, maxd;
+	unsigned int i;
+	__u32 interval;
+	int ret = 0;
+	__u8 *fcc;
+
+	if (fmt->type != stream->type)
+		return -EINVAL;
+
+	fcc = (__u8 *)&fmt->fmt.pix.pixelformat;
+	uvc_trace(UVC_TRACE_FORMAT, "Trying format 0x%08x (%c%c%c%c): %ux%u.\n",
+			fmt->fmt.pix.pixelformat,
+			fcc[0], fcc[1], fcc[2], fcc[3],
+			fmt->fmt.pix.width, fmt->fmt.pix.height);
+
+	/* Check if the hardware supports the requested format, use the default
+	 * format otherwise.
+	 */
+	for (i = 0; i < stream->nformats; ++i) {
+		format = &stream->format[i];
+		if (format->fcc == fmt->fmt.pix.pixelformat)
+			break;
+	}
+
+	if (i == stream->nformats) {
+		format = stream->def_format;
+		fmt->fmt.pix.pixelformat = format->fcc;
+	}
+
+	/* Find the closest image size. The distance between image sizes is
+	 * the size in pixels of the non-overlapping regions between the
+	 * requested size and the frame-specified size.
+	 */
+	rw = fmt->fmt.pix.width;
+	rh = fmt->fmt.pix.height;
+	maxd = (unsigned int)-1;
+
+	for (i = 0; i < format->nframes; ++i) {
+		__u16 w = format->frame[i].wWidth;
+		__u16 h = format->frame[i].wHeight;
+
+		d = min(w, rw) * min(h, rh);
+		d = w*h + rw*rh - 2*d;
+		if (d < maxd) {
+			maxd = d;
+			frame = &format->frame[i];
+		}
+
+		if (maxd == 0)
+			break;
+	}
+
+	if (frame == NULL) {
+		uvc_trace(UVC_TRACE_FORMAT, "Unsupported size %ux%u.\n",
+				fmt->fmt.pix.width, fmt->fmt.pix.height);
+		return -EINVAL;
+	}
+
+	/* Use the default frame interval. */
+	interval = frame->dwDefaultFrameInterval;
+	uvc_trace(UVC_TRACE_FORMAT, "Using default frame interval %u.%u us "
+		"(%u.%u fps).\n", interval/10, interval%10, 10000000/interval,
+		(100000000/interval)%10);
+
+	/* Set the format index, frame index and frame interval. */
+	memset(probe, 0, sizeof *probe);
+	probe->bmHint = 1;	/* dwFrameInterval */
+	probe->bFormatIndex = format->index;
+	probe->bFrameIndex = frame->bFrameIndex;
+	probe->dwFrameInterval = uvc_try_frame_interval(frame, interval);
+	/* Some webcams stall the probe control set request when the
+	 * dwMaxVideoFrameSize field is set to zero. The UVC specification
+	 * clearly states that the field is read-only from the host, so this
+	 * is a webcam bug. Set dwMaxVideoFrameSize to the value reported by
+	 * the webcam to work around the problem.
+	 *
+	 * The workaround could probably be enabled for all webcams, so the
+	 * quirk can be removed if needed. It's currently useful to detect
+	 * webcam bugs and fix them before they hit the market (providing
+	 * developers test their webcams with the Linux driver as well as with
+	 * the Windows driver).
+	 */
+	mutex_lock(&stream->mutex);
+	if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
+		probe->dwMaxVideoFrameSize =
+			stream->ctrl.dwMaxVideoFrameSize;
+
+	/* Probe the device. */
+	ret = uvc_probe_video(stream, probe);
+	mutex_unlock(&stream->mutex);
+	if (ret < 0)
+		goto done;
+
+	fmt->fmt.pix.width = frame->wWidth;
+	fmt->fmt.pix.height = frame->wHeight;
+	fmt->fmt.pix.field = V4L2_FIELD_NONE;
+	fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
+	fmt->fmt.pix.sizeimage = probe->dwMaxVideoFrameSize;
+	fmt->fmt.pix.colorspace = format->colorspace;
+	fmt->fmt.pix.priv = 0;
+
+	if (uvc_format != NULL)
+		*uvc_format = format;
+	if (uvc_frame != NULL)
+		*uvc_frame = frame;
+
+done:
+	return ret;
+}
+
+static int uvc_v4l2_get_format(struct uvc_streaming *stream,
+	struct v4l2_format *fmt)
+{
+	struct uvc_format *format;
+	struct uvc_frame *frame;
+	int ret = 0;
+
+	if (fmt->type != stream->type)
+		return -EINVAL;
+
+	mutex_lock(&stream->mutex);
+	format = stream->cur_format;
+	frame = stream->cur_frame;
+
+	if (format == NULL || frame == NULL) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	fmt->fmt.pix.pixelformat = format->fcc;
+	fmt->fmt.pix.width = frame->wWidth;
+	fmt->fmt.pix.height = frame->wHeight;
+	fmt->fmt.pix.field = V4L2_FIELD_NONE;
+	fmt->fmt.pix.bytesperline = format->bpp * frame->wWidth / 8;
+	fmt->fmt.pix.sizeimage = stream->ctrl.dwMaxVideoFrameSize;
+	fmt->fmt.pix.colorspace = format->colorspace;
+	fmt->fmt.pix.priv = 0;
+
+done:
+	mutex_unlock(&stream->mutex);
+	return ret;
+}
+
+static int uvc_v4l2_set_format(struct uvc_streaming *stream,
+	struct v4l2_format *fmt)
+{
+	struct uvc_streaming_control probe;
+	struct uvc_format *format;
+	struct uvc_frame *frame;
+	int ret;
+
+	if (fmt->type != stream->type)
+		return -EINVAL;
+
+	ret = uvc_v4l2_try_format(stream, fmt, &probe, &format, &frame);
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&stream->mutex);
+
+	if (uvc_queue_allocated(&stream->queue)) {
+		ret = -EBUSY;
+		goto done;
+	}
+
+	stream->ctrl = probe;
+	stream->cur_format = format;
+	stream->cur_frame = frame;
+
+done:
+	mutex_unlock(&stream->mutex);
+	return ret;
+}
+
+static int uvc_v4l2_get_streamparm(struct uvc_streaming *stream,
+		struct v4l2_streamparm *parm)
+{
+	uint32_t numerator, denominator;
+
+	if (parm->type != stream->type)
+		return -EINVAL;
+
+	mutex_lock(&stream->mutex);
+	numerator = stream->ctrl.dwFrameInterval;
+	mutex_unlock(&stream->mutex);
+
+	denominator = 10000000;
+	uvc_simplify_fraction(&numerator, &denominator, 8, 333);
+
+	memset(parm, 0, sizeof *parm);
+	parm->type = stream->type;
+
+	if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
+		parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
+		parm->parm.capture.capturemode = 0;
+		parm->parm.capture.timeperframe.numerator = numerator;
+		parm->parm.capture.timeperframe.denominator = denominator;
+		parm->parm.capture.extendedmode = 0;
+		parm->parm.capture.readbuffers = 0;
+	} else {
+		parm->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
+		parm->parm.output.outputmode = 0;
+		parm->parm.output.timeperframe.numerator = numerator;
+		parm->parm.output.timeperframe.denominator = denominator;
+	}
+
+	return 0;
+}
+
+static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
+		struct v4l2_streamparm *parm)
+{
+	struct uvc_streaming_control probe;
+	struct v4l2_fract timeperframe;
+	uint32_t interval;
+	int ret;
+
+	if (parm->type != stream->type)
+		return -EINVAL;
+
+	if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		timeperframe = parm->parm.capture.timeperframe;
+	else
+		timeperframe = parm->parm.output.timeperframe;
+
+	interval = uvc_fraction_to_interval(timeperframe.numerator,
+		timeperframe.denominator);
+	uvc_trace(UVC_TRACE_FORMAT, "Setting frame interval to %u/%u (%u).\n",
+		timeperframe.numerator, timeperframe.denominator, interval);
+
+	mutex_lock(&stream->mutex);
+
+	if (uvc_queue_streaming(&stream->queue)) {
+		mutex_unlock(&stream->mutex);
+		return -EBUSY;
+	}
+
+	probe = stream->ctrl;
+	probe.dwFrameInterval =
+		uvc_try_frame_interval(stream->cur_frame, interval);
+
+	/* Probe the device with the new settings. */
+	ret = uvc_probe_video(stream, &probe);
+	if (ret < 0) {
+		mutex_unlock(&stream->mutex);
+		return ret;
+	}
+
+	stream->ctrl = probe;
+	mutex_unlock(&stream->mutex);
+
+	/* Return the actual frame period. */
+	timeperframe.numerator = probe.dwFrameInterval;
+	timeperframe.denominator = 10000000;
+	uvc_simplify_fraction(&timeperframe.numerator,
+		&timeperframe.denominator, 8, 333);
+
+	if (parm->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		parm->parm.capture.timeperframe = timeperframe;
+	else
+		parm->parm.output.timeperframe = timeperframe;
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------
+ * Privilege management
+ */
+
+/*
+ * Privilege management is the multiple-open implementation basis. The current
+ * implementation is completely transparent for the end-user and doesn't
+ * require explicit use of the VIDIOC_G_PRIORITY and VIDIOC_S_PRIORITY ioctls.
+ * Those ioctls enable finer control on the device (by making possible for a
+ * user to request exclusive access to a device), but are not mature yet.
+ * Switching to the V4L2 priority mechanism might be considered in the future
+ * if this situation changes.
+ *
+ * Each open instance of a UVC device can either be in a privileged or
+ * unprivileged state. Only a single instance can be in a privileged state at
+ * a given time. Trying to perform an operation that requires privileges will
+ * automatically acquire the required privileges if possible, or return -EBUSY
+ * otherwise. Privileges are dismissed when closing the instance or when
+ * freeing the video buffers using VIDIOC_REQBUFS.
+ *
+ * Operations that require privileges are:
+ *
+ * - VIDIOC_S_INPUT
+ * - VIDIOC_S_PARM
+ * - VIDIOC_S_FMT
+ * - VIDIOC_REQBUFS
+ */
+static int uvc_acquire_privileges(struct uvc_fh *handle)
+{
+	/* Always succeed if the handle is already privileged. */
+	if (handle->state == UVC_HANDLE_ACTIVE)
+		return 0;
+
+	/* Check if the device already has a privileged handle. */
+	if (atomic_inc_return(&handle->stream->active) != 1) {
+		atomic_dec(&handle->stream->active);
+		return -EBUSY;
+	}
+
+	handle->state = UVC_HANDLE_ACTIVE;
+	return 0;
+}
+
+static void uvc_dismiss_privileges(struct uvc_fh *handle)
+{
+	if (handle->state == UVC_HANDLE_ACTIVE)
+		atomic_dec(&handle->stream->active);
+
+	handle->state = UVC_HANDLE_PASSIVE;
+}
+
+static int uvc_has_privileges(struct uvc_fh *handle)
+{
+	return handle->state == UVC_HANDLE_ACTIVE;
+}
+
+/* ------------------------------------------------------------------------
+ * V4L2 file operations
+ */
+
+static int uvc_v4l2_open(struct file *file)
+{
+	struct uvc_streaming *stream;
+	struct uvc_fh *handle;
+	int ret = 0;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_open\n");
+	stream = video_drvdata(file);
+
+	if (stream->dev->state & UVC_DEV_DISCONNECTED)
+		return -ENODEV;
+
+	ret = usb_autopm_get_interface(stream->dev->intf);
+	if (ret < 0)
+		return ret;
+
+	/* Create the device handle. */
+	handle = kzalloc(sizeof *handle, GFP_KERNEL);
+	if (handle == NULL) {
+		usb_autopm_put_interface(stream->dev->intf);
+		return -ENOMEM;
+	}
+
+	mutex_lock(&stream->dev->lock);
+	if (stream->dev->users == 0) {
+		ret = uvc_status_start(stream->dev, GFP_KERNEL);
+		if (ret < 0) {
+			mutex_unlock(&stream->dev->lock);
+			usb_autopm_put_interface(stream->dev->intf);
+			kfree(handle);
+			return ret;
+		}
+	}
+
+	stream->dev->users++;
+	mutex_unlock(&stream->dev->lock);
+
+	v4l2_fh_init(&handle->vfh, &stream->vdev);
+	v4l2_fh_add(&handle->vfh);
+	handle->chain = stream->chain;
+	handle->stream = stream;
+	handle->state = UVC_HANDLE_PASSIVE;
+	file->private_data = handle;
+
+	return 0;
+}
+
+static int uvc_v4l2_release(struct file *file)
+{
+	struct uvc_fh *handle = file->private_data;
+	struct uvc_streaming *stream = handle->stream;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_release\n");
+
+	/* Only free resources if this is a privileged handle. */
+	if (uvc_has_privileges(handle))
+		uvc_queue_release(&stream->queue);
+
+	/* Release the file handle. */
+	uvc_dismiss_privileges(handle);
+	v4l2_fh_del(&handle->vfh);
+	v4l2_fh_exit(&handle->vfh);
+	kfree(handle);
+	file->private_data = NULL;
+
+	mutex_lock(&stream->dev->lock);
+	if (--stream->dev->users == 0)
+		uvc_status_stop(stream->dev);
+	mutex_unlock(&stream->dev->lock);
+
+	usb_autopm_put_interface(stream->dev->intf);
+	return 0;
+}
+
+static int uvc_ioctl_querycap(struct file *file, void *fh,
+			      struct v4l2_capability *cap)
+{
+	struct video_device *vdev = video_devdata(file);
+	struct uvc_fh *handle = file->private_data;
+	struct uvc_video_chain *chain = handle->chain;
+	struct uvc_streaming *stream = handle->stream;
+
+	strlcpy(cap->driver, "uvcvideo", sizeof(cap->driver));
+	strlcpy(cap->card, vdev->name, sizeof(cap->card));
+	usb_make_path(stream->dev->udev, cap->bus_info, sizeof(cap->bus_info));
+	cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
+			  | chain->caps;
+	if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+		cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
+	else
+		cap->device_caps = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_STREAMING;
+
+	return 0;
+}
+
+static int uvc_ioctl_enum_fmt(struct uvc_streaming *stream,
+			      struct v4l2_fmtdesc *fmt)
+{
+	struct uvc_format *format;
+	enum v4l2_buf_type type = fmt->type;
+	__u32 index = fmt->index;
+
+	if (fmt->type != stream->type || fmt->index >= stream->nformats)
+		return -EINVAL;
+
+	memset(fmt, 0, sizeof(*fmt));
+	fmt->index = index;
+	fmt->type = type;
+
+	format = &stream->format[fmt->index];
+	fmt->flags = 0;
+	if (format->flags & UVC_FMT_FLAG_COMPRESSED)
+		fmt->flags |= V4L2_FMT_FLAG_COMPRESSED;
+	strlcpy(fmt->description, format->name, sizeof(fmt->description));
+	fmt->description[sizeof(fmt->description) - 1] = 0;
+	fmt->pixelformat = format->fcc;
+	return 0;
+}
+
+static int uvc_ioctl_enum_fmt_vid_cap(struct file *file, void *fh,
+				      struct v4l2_fmtdesc *fmt)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	return uvc_ioctl_enum_fmt(stream, fmt);
+}
+
+static int uvc_ioctl_enum_fmt_vid_out(struct file *file, void *fh,
+				      struct v4l2_fmtdesc *fmt)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	return uvc_ioctl_enum_fmt(stream, fmt);
+}
+
+static int uvc_ioctl_g_fmt_vid_cap(struct file *file, void *fh,
+				   struct v4l2_format *fmt)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	return uvc_v4l2_get_format(stream, fmt);
+}
+
+static int uvc_ioctl_g_fmt_vid_out(struct file *file, void *fh,
+				   struct v4l2_format *fmt)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	return uvc_v4l2_get_format(stream, fmt);
+}
+
+static int uvc_ioctl_s_fmt_vid_cap(struct file *file, void *fh,
+				   struct v4l2_format *fmt)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	int ret;
+
+	ret = uvc_acquire_privileges(handle);
+	if (ret < 0)
+		return ret;
+
+	return uvc_v4l2_set_format(stream, fmt);
+}
+
+static int uvc_ioctl_s_fmt_vid_out(struct file *file, void *fh,
+				   struct v4l2_format *fmt)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	int ret;
+
+	ret = uvc_acquire_privileges(handle);
+	if (ret < 0)
+		return ret;
+
+	return uvc_v4l2_set_format(stream, fmt);
+}
+
+static int uvc_ioctl_try_fmt_vid_cap(struct file *file, void *fh,
+				     struct v4l2_format *fmt)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	struct uvc_streaming_control probe;
+
+	return uvc_v4l2_try_format(stream, fmt, &probe, NULL, NULL);
+}
+
+static int uvc_ioctl_try_fmt_vid_out(struct file *file, void *fh,
+				     struct v4l2_format *fmt)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	struct uvc_streaming_control probe;
+
+	return uvc_v4l2_try_format(stream, fmt, &probe, NULL, NULL);
+}
+
+static int uvc_ioctl_reqbufs(struct file *file, void *fh,
+			     struct v4l2_requestbuffers *rb)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	int ret;
+
+	ret = uvc_acquire_privileges(handle);
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&stream->mutex);
+	ret = uvc_request_buffers(&stream->queue, rb);
+	mutex_unlock(&stream->mutex);
+	if (ret < 0)
+		return ret;
+
+	if (ret == 0)
+		uvc_dismiss_privileges(handle);
+
+	return 0;
+}
+
+static int uvc_ioctl_querybuf(struct file *file, void *fh,
+			      struct v4l2_buffer *buf)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	if (!uvc_has_privileges(handle))
+		return -EBUSY;
+
+	return uvc_query_buffer(&stream->queue, buf);
+}
+
+static int uvc_ioctl_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	if (!uvc_has_privileges(handle))
+		return -EBUSY;
+
+	return uvc_queue_buffer(&stream->queue, buf);
+}
+
+static int uvc_ioctl_dqbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	if (!uvc_has_privileges(handle))
+		return -EBUSY;
+
+	return uvc_dequeue_buffer(&stream->queue, buf,
+				  file->f_flags & O_NONBLOCK);
+}
+
+static int uvc_ioctl_create_bufs(struct file *file, void *fh,
+				  struct v4l2_create_buffers *cb)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	int ret;
+
+	ret = uvc_acquire_privileges(handle);
+	if (ret < 0)
+		return ret;
+
+	return uvc_create_buffers(&stream->queue, cb);
+}
+
+static int uvc_ioctl_streamon(struct file *file, void *fh,
+			      enum v4l2_buf_type type)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	int ret;
+
+	if (!uvc_has_privileges(handle))
+		return -EBUSY;
+
+	mutex_lock(&stream->mutex);
+	ret = uvc_queue_streamon(&stream->queue, type);
+	mutex_unlock(&stream->mutex);
+
+	return ret;
+}
+
+static int uvc_ioctl_streamoff(struct file *file, void *fh,
+			       enum v4l2_buf_type type)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	if (!uvc_has_privileges(handle))
+		return -EBUSY;
+
+	mutex_lock(&stream->mutex);
+	uvc_queue_streamoff(&stream->queue, type);
+	mutex_unlock(&stream->mutex);
+
+	return 0;
+}
+
+static int uvc_ioctl_enum_input(struct file *file, void *fh,
+				struct v4l2_input *input)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+	const struct uvc_entity *selector = chain->selector;
+	struct uvc_entity *iterm = NULL;
+	u32 index = input->index;
+	int pin = 0;
+
+	if (selector == NULL ||
+	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
+		if (index != 0)
+			return -EINVAL;
+		list_for_each_entry(iterm, &chain->entities, chain) {
+			if (UVC_ENTITY_IS_ITERM(iterm))
+				break;
+		}
+		pin = iterm->id;
+	} else if (index < selector->bNrInPins) {
+		pin = selector->baSourceID[index];
+		list_for_each_entry(iterm, &chain->entities, chain) {
+			if (!UVC_ENTITY_IS_ITERM(iterm))
+				continue;
+			if (iterm->id == pin)
+				break;
+		}
+	}
+
+	if (iterm == NULL || iterm->id != pin)
+		return -EINVAL;
+
+	memset(input, 0, sizeof(*input));
+	input->index = index;
+	strlcpy(input->name, iterm->name, sizeof(input->name));
+	if (UVC_ENTITY_TYPE(iterm) == UVC_ITT_CAMERA)
+		input->type = V4L2_INPUT_TYPE_CAMERA;
+
+	return 0;
+}
+
+static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+	int ret;
+	u8 i;
+
+	if (chain->selector == NULL ||
+	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
+		*input = 0;
+		return 0;
+	}
+
+	ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id,
+			     chain->dev->intfnum,  UVC_SU_INPUT_SELECT_CONTROL,
+			     &i, 1);
+	if (ret < 0)
+		return ret;
+
+	*input = i - 1;
+	return 0;
+}
+
+static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+	int ret;
+	u32 i;
+
+	ret = uvc_acquire_privileges(handle);
+	if (ret < 0)
+		return ret;
+
+	if (chain->selector == NULL ||
+	    (chain->dev->quirks & UVC_QUIRK_IGNORE_SELECTOR_UNIT)) {
+		if (input)
+			return -EINVAL;
+		return 0;
+	}
+
+	if (input >= chain->selector->bNrInPins)
+		return -EINVAL;
+
+	i = input + 1;
+	return uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id,
+			      chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
+			      &i, 1);
+}
+
+static int uvc_ioctl_queryctrl(struct file *file, void *fh,
+			       struct v4l2_queryctrl *qc)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+
+	return uvc_query_v4l2_ctrl(chain, qc);
+}
+
+static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
+				    struct v4l2_query_ext_ctrl *qec)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+	struct v4l2_queryctrl qc = { qec->id };
+	int ret;
+
+	ret = uvc_query_v4l2_ctrl(chain, &qc);
+	if (ret)
+		return ret;
+
+	qec->id = qc.id;
+	qec->type = qc.type;
+	strlcpy(qec->name, qc.name, sizeof(qec->name));
+	qec->minimum = qc.minimum;
+	qec->maximum = qc.maximum;
+	qec->step = qc.step;
+	qec->default_value = qc.default_value;
+	qec->flags = qc.flags;
+	qec->elem_size = 4;
+	qec->elems = 1;
+	qec->nr_of_dims = 0;
+	memset(qec->dims, 0, sizeof(qec->dims));
+	memset(qec->reserved, 0, sizeof(qec->reserved));
+
+	return 0;
+}
+
+static int uvc_ioctl_g_ctrl(struct file *file, void *fh,
+			    struct v4l2_control *ctrl)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+	struct v4l2_ext_control xctrl;
+	int ret;
+
+	memset(&xctrl, 0, sizeof(xctrl));
+	xctrl.id = ctrl->id;
+
+	ret = uvc_ctrl_begin(chain);
+	if (ret < 0)
+		return ret;
+
+	ret = uvc_ctrl_get(chain, &xctrl);
+	uvc_ctrl_rollback(handle);
+	if (ret < 0)
+		return ret;
+
+	ctrl->value = xctrl.value;
+	return 0;
+}
+
+static int uvc_ioctl_s_ctrl(struct file *file, void *fh,
+			    struct v4l2_control *ctrl)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+	struct v4l2_ext_control xctrl;
+	int ret;
+
+	memset(&xctrl, 0, sizeof(xctrl));
+	xctrl.id = ctrl->id;
+	xctrl.value = ctrl->value;
+
+	ret = uvc_ctrl_begin(chain);
+	if (ret < 0)
+		return ret;
+
+	ret = uvc_ctrl_set(chain, &xctrl);
+	if (ret < 0) {
+		uvc_ctrl_rollback(handle);
+		return ret;
+	}
+
+	ret = uvc_ctrl_commit(handle, &xctrl, 1);
+	if (ret < 0)
+		return ret;
+
+	ctrl->value = xctrl.value;
+	return 0;
+}
+
+static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
+				 struct v4l2_ext_controls *ctrls)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+	struct v4l2_ext_control *ctrl = ctrls->controls;
+	unsigned int i;
+	int ret;
+
+	ret = uvc_ctrl_begin(chain);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ctrls->count; ++ctrl, ++i) {
+		ret = uvc_ctrl_get(chain, ctrl);
+		if (ret < 0) {
+			uvc_ctrl_rollback(handle);
+			ctrls->error_idx = i;
+			return ret;
+		}
+	}
+
+	ctrls->error_idx = 0;
+
+	return uvc_ctrl_rollback(handle);
+}
+
+static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
+				     struct v4l2_ext_controls *ctrls,
+				     bool commit)
+{
+	struct v4l2_ext_control *ctrl = ctrls->controls;
+	struct uvc_video_chain *chain = handle->chain;
+	unsigned int i;
+	int ret;
+
+	ret = uvc_ctrl_begin(chain);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ctrls->count; ++ctrl, ++i) {
+		ret = uvc_ctrl_set(chain, ctrl);
+		if (ret < 0) {
+			uvc_ctrl_rollback(handle);
+			ctrls->error_idx = commit ? ctrls->count : i;
+			return ret;
+		}
+	}
+
+	ctrls->error_idx = 0;
+
+	if (commit)
+		return uvc_ctrl_commit(handle, ctrls->controls, ctrls->count);
+	else
+		return uvc_ctrl_rollback(handle);
+}
+
+static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
+				 struct v4l2_ext_controls *ctrls)
+{
+	struct uvc_fh *handle = fh;
+
+	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, true);
+}
+
+static int uvc_ioctl_try_ext_ctrls(struct file *file, void *fh,
+				   struct v4l2_ext_controls *ctrls)
+{
+	struct uvc_fh *handle = fh;
+
+	return uvc_ioctl_s_try_ext_ctrls(handle, ctrls, false);
+}
+
+static int uvc_ioctl_querymenu(struct file *file, void *fh,
+			       struct v4l2_querymenu *qm)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+
+	return uvc_query_v4l2_menu(chain, qm);
+}
+
+static int uvc_ioctl_g_selection(struct file *file, void *fh,
+				 struct v4l2_selection *sel)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	if (sel->type != stream->type)
+		return -EINVAL;
+
+	switch (sel->target) {
+	case V4L2_SEL_TGT_CROP_DEFAULT:
+	case V4L2_SEL_TGT_CROP_BOUNDS:
+		if (stream->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
+			return -EINVAL;
+		break;
+	case V4L2_SEL_TGT_COMPOSE_DEFAULT:
+	case V4L2_SEL_TGT_COMPOSE_BOUNDS:
+		if (stream->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	sel->r.left = 0;
+	sel->r.top = 0;
+	mutex_lock(&stream->mutex);
+	sel->r.width = stream->cur_frame->wWidth;
+	sel->r.height = stream->cur_frame->wHeight;
+	mutex_unlock(&stream->mutex);
+
+	return 0;
+}
+
+static int uvc_ioctl_g_parm(struct file *file, void *fh,
+			    struct v4l2_streamparm *parm)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+
+	return uvc_v4l2_get_streamparm(stream, parm);
+}
+
+static int uvc_ioctl_s_parm(struct file *file, void *fh,
+			    struct v4l2_streamparm *parm)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	int ret;
+
+	ret = uvc_acquire_privileges(handle);
+	if (ret < 0)
+		return ret;
+
+	return uvc_v4l2_set_streamparm(stream, parm);
+}
+
+static int uvc_ioctl_enum_framesizes(struct file *file, void *fh,
+				     struct v4l2_frmsizeenum *fsize)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	struct uvc_format *format = NULL;
+	struct uvc_frame *frame;
+	int i;
+
+	/* Look for the given pixel format */
+	for (i = 0; i < stream->nformats; i++) {
+		if (stream->format[i].fcc == fsize->pixel_format) {
+			format = &stream->format[i];
+			break;
+		}
+	}
+	if (format == NULL)
+		return -EINVAL;
+
+	if (fsize->index >= format->nframes)
+		return -EINVAL;
+
+	frame = &format->frame[fsize->index];
+	fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
+	fsize->discrete.width = frame->wWidth;
+	fsize->discrete.height = frame->wHeight;
+	return 0;
+}
+
+static int uvc_ioctl_enum_frameintervals(struct file *file, void *fh,
+					 struct v4l2_frmivalenum *fival)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_streaming *stream = handle->stream;
+	struct uvc_format *format = NULL;
+	struct uvc_frame *frame = NULL;
+	int i;
+
+	/* Look for the given pixel format and frame size */
+	for (i = 0; i < stream->nformats; i++) {
+		if (stream->format[i].fcc == fival->pixel_format) {
+			format = &stream->format[i];
+			break;
+		}
+	}
+	if (format == NULL)
+		return -EINVAL;
+
+	for (i = 0; i < format->nframes; i++) {
+		if (format->frame[i].wWidth == fival->width &&
+		    format->frame[i].wHeight == fival->height) {
+			frame = &format->frame[i];
+			break;
+		}
+	}
+	if (frame == NULL)
+		return -EINVAL;
+
+	if (frame->bFrameIntervalType) {
+		if (fival->index >= frame->bFrameIntervalType)
+			return -EINVAL;
+
+		fival->type = V4L2_FRMIVAL_TYPE_DISCRETE;
+		fival->discrete.numerator =
+			frame->dwFrameInterval[fival->index];
+		fival->discrete.denominator = 10000000;
+		uvc_simplify_fraction(&fival->discrete.numerator,
+			&fival->discrete.denominator, 8, 333);
+	} else {
+		if (fival->index)
+			return -EINVAL;
+
+		fival->type = V4L2_FRMIVAL_TYPE_STEPWISE;
+		fival->stepwise.min.numerator = frame->dwFrameInterval[0];
+		fival->stepwise.min.denominator = 10000000;
+		fival->stepwise.max.numerator = frame->dwFrameInterval[1];
+		fival->stepwise.max.denominator = 10000000;
+		fival->stepwise.step.numerator = frame->dwFrameInterval[2];
+		fival->stepwise.step.denominator = 10000000;
+		uvc_simplify_fraction(&fival->stepwise.min.numerator,
+			&fival->stepwise.min.denominator, 8, 333);
+		uvc_simplify_fraction(&fival->stepwise.max.numerator,
+			&fival->stepwise.max.denominator, 8, 333);
+		uvc_simplify_fraction(&fival->stepwise.step.numerator,
+			&fival->stepwise.step.denominator, 8, 333);
+	}
+
+	return 0;
+}
+
+static int uvc_ioctl_subscribe_event(struct v4l2_fh *fh,
+				     const struct v4l2_event_subscription *sub)
+{
+	switch (sub->type) {
+	case V4L2_EVENT_CTRL:
+		return v4l2_event_subscribe(fh, sub, 0, &uvc_ctrl_sub_ev_ops);
+	default:
+		return -EINVAL;
+	}
+}
+
+static long uvc_ioctl_default(struct file *file, void *fh, bool valid_prio,
+			      unsigned int cmd, void *arg)
+{
+	struct uvc_fh *handle = fh;
+	struct uvc_video_chain *chain = handle->chain;
+
+	switch (cmd) {
+	/* Dynamic controls. */
+	case UVCIOC_CTRL_MAP:
+		return uvc_ioctl_ctrl_map(chain, arg);
+
+	case UVCIOC_CTRL_QUERY:
+		return uvc_xu_ctrl_query(chain, arg);
+
+	default:
+		return -ENOTTY;
+	}
+}
+
+#ifdef CONFIG_COMPAT
+struct uvc_xu_control_mapping32 {
+	__u32 id;
+	__u8 name[32];
+	__u8 entity[16];
+	__u8 selector;
+
+	__u8 size;
+	__u8 offset;
+	__u32 v4l2_type;
+	__u32 data_type;
+
+	compat_caddr_t menu_info;
+	__u32 menu_count;
+
+	__u32 reserved[4];
+};
+
+static int uvc_v4l2_get_xu_mapping(struct uvc_xu_control_mapping *kp,
+			const struct uvc_xu_control_mapping32 __user *up)
+{
+	struct uvc_menu_info __user *umenus;
+	struct uvc_menu_info __user *kmenus;
+	compat_caddr_t p;
+
+	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
+	    __copy_from_user(kp, up, offsetof(typeof(*up), menu_info)) ||
+	    __get_user(kp->menu_count, &up->menu_count))
+		return -EFAULT;
+
+	memset(kp->reserved, 0, sizeof(kp->reserved));
+
+	if (kp->menu_count == 0) {
+		kp->menu_info = NULL;
+		return 0;
+	}
+
+	if (__get_user(p, &up->menu_info))
+		return -EFAULT;
+	umenus = compat_ptr(p);
+	if (!access_ok(VERIFY_READ, umenus, kp->menu_count * sizeof(*umenus)))
+		return -EFAULT;
+
+	kmenus = compat_alloc_user_space(kp->menu_count * sizeof(*kmenus));
+	if (kmenus == NULL)
+		return -EFAULT;
+	kp->menu_info = kmenus;
+
+	if (copy_in_user(kmenus, umenus, kp->menu_count * sizeof(*umenus)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int uvc_v4l2_put_xu_mapping(const struct uvc_xu_control_mapping *kp,
+			struct uvc_xu_control_mapping32 __user *up)
+{
+	struct uvc_menu_info __user *umenus;
+	struct uvc_menu_info __user *kmenus = kp->menu_info;
+	compat_caddr_t p;
+
+	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
+	    __copy_to_user(up, kp, offsetof(typeof(*up), menu_info)) ||
+	    __put_user(kp->menu_count, &up->menu_count))
+		return -EFAULT;
+
+	if (__clear_user(up->reserved, sizeof(up->reserved)))
+		return -EFAULT;
+
+	if (kp->menu_count == 0)
+		return 0;
+
+	if (get_user(p, &up->menu_info))
+		return -EFAULT;
+	umenus = compat_ptr(p);
+
+	if (copy_in_user(umenus, kmenus, kp->menu_count * sizeof(*umenus)))
+		return -EFAULT;
+
+	return 0;
+}
+
+struct uvc_xu_control_query32 {
+	__u8 unit;
+	__u8 selector;
+	__u8 query;
+	__u16 size;
+	compat_caddr_t data;
+};
+
+static int uvc_v4l2_get_xu_query(struct uvc_xu_control_query *kp,
+			const struct uvc_xu_control_query32 __user *up)
+{
+	u8 __user *udata;
+	u8 __user *kdata;
+	compat_caddr_t p;
+
+	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
+	    __copy_from_user(kp, up, offsetof(typeof(*up), data)))
+		return -EFAULT;
+
+	if (kp->size == 0) {
+		kp->data = NULL;
+		return 0;
+	}
+
+	if (__get_user(p, &up->data))
+		return -EFAULT;
+	udata = compat_ptr(p);
+	if (!access_ok(VERIFY_READ, udata, kp->size))
+		return -EFAULT;
+
+	kdata = compat_alloc_user_space(kp->size);
+	if (kdata == NULL)
+		return -EFAULT;
+	kp->data = kdata;
+
+	if (copy_in_user(kdata, udata, kp->size))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int uvc_v4l2_put_xu_query(const struct uvc_xu_control_query *kp,
+			struct uvc_xu_control_query32 __user *up)
+{
+	u8 __user *udata;
+	u8 __user *kdata = kp->data;
+	compat_caddr_t p;
+
+	if (!access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
+	    __copy_to_user(up, kp, offsetof(typeof(*up), data)))
+		return -EFAULT;
+
+	if (kp->size == 0)
+		return 0;
+
+	if (get_user(p, &up->data))
+		return -EFAULT;
+	udata = compat_ptr(p);
+	if (!access_ok(VERIFY_READ, udata, kp->size))
+		return -EFAULT;
+
+	if (copy_in_user(udata, kdata, kp->size))
+		return -EFAULT;
+
+	return 0;
+}
+
+#define UVCIOC_CTRL_MAP32	_IOWR('u', 0x20, struct uvc_xu_control_mapping32)
+#define UVCIOC_CTRL_QUERY32	_IOWR('u', 0x21, struct uvc_xu_control_query32)
+
+static long uvc_v4l2_compat_ioctl32(struct file *file,
+		     unsigned int cmd, unsigned long arg)
+{
+	union {
+		struct uvc_xu_control_mapping xmap;
+		struct uvc_xu_control_query xqry;
+	} karg;
+	void __user *up = compat_ptr(arg);
+	mm_segment_t old_fs;
+	long ret;
+
+	switch (cmd) {
+	case UVCIOC_CTRL_MAP32:
+		cmd = UVCIOC_CTRL_MAP;
+		ret = uvc_v4l2_get_xu_mapping(&karg.xmap, up);
+		break;
+
+	case UVCIOC_CTRL_QUERY32:
+		cmd = UVCIOC_CTRL_QUERY;
+		ret = uvc_v4l2_get_xu_query(&karg.xqry, up);
+		break;
+
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	old_fs = get_fs();
+	set_fs(KERNEL_DS);
+	ret = video_ioctl2(file, cmd, (unsigned long)&karg);
+	set_fs(old_fs);
+
+	if (ret < 0)
+		return ret;
+
+	switch (cmd) {
+	case UVCIOC_CTRL_MAP:
+		ret = uvc_v4l2_put_xu_mapping(&karg.xmap, up);
+		break;
+
+	case UVCIOC_CTRL_QUERY:
+		ret = uvc_v4l2_put_xu_query(&karg.xqry, up);
+		break;
+	}
+
+	return ret;
+}
+#endif
+
+static ssize_t uvc_v4l2_read(struct file *file, char __user *data,
+		    size_t count, loff_t *ppos)
+{
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_read: not implemented.\n");
+	return -EINVAL;
+}
+
+static int uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct uvc_fh *handle = file->private_data;
+	struct uvc_streaming *stream = handle->stream;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_mmap\n");
+
+	return uvc_queue_mmap(&stream->queue, vma);
+}
+
+static unsigned int uvc_v4l2_poll(struct file *file, poll_table *wait)
+{
+	struct uvc_fh *handle = file->private_data;
+	struct uvc_streaming *stream = handle->stream;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_poll\n");
+
+	return uvc_queue_poll(&stream->queue, file, wait);
+}
+
+#ifndef CONFIG_MMU
+static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
+		unsigned long addr, unsigned long len, unsigned long pgoff,
+		unsigned long flags)
+{
+	struct uvc_fh *handle = file->private_data;
+	struct uvc_streaming *stream = handle->stream;
+
+	uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_get_unmapped_area\n");
+
+	return uvc_queue_get_unmapped_area(&stream->queue, pgoff);
+}
+#endif
+
+const struct v4l2_ioctl_ops uvc_ioctl_ops = {
+	.vidioc_querycap = uvc_ioctl_querycap,
+	.vidioc_enum_fmt_vid_cap = uvc_ioctl_enum_fmt_vid_cap,
+	.vidioc_enum_fmt_vid_out = uvc_ioctl_enum_fmt_vid_out,
+	.vidioc_g_fmt_vid_cap = uvc_ioctl_g_fmt_vid_cap,
+	.vidioc_g_fmt_vid_out = uvc_ioctl_g_fmt_vid_out,
+	.vidioc_s_fmt_vid_cap = uvc_ioctl_s_fmt_vid_cap,
+	.vidioc_s_fmt_vid_out = uvc_ioctl_s_fmt_vid_out,
+	.vidioc_try_fmt_vid_cap = uvc_ioctl_try_fmt_vid_cap,
+	.vidioc_try_fmt_vid_out = uvc_ioctl_try_fmt_vid_out,
+	.vidioc_reqbufs = uvc_ioctl_reqbufs,
+	.vidioc_querybuf = uvc_ioctl_querybuf,
+	.vidioc_qbuf = uvc_ioctl_qbuf,
+	.vidioc_dqbuf = uvc_ioctl_dqbuf,
+	.vidioc_create_bufs = uvc_ioctl_create_bufs,
+	.vidioc_streamon = uvc_ioctl_streamon,
+	.vidioc_streamoff = uvc_ioctl_streamoff,
+	.vidioc_enum_input = uvc_ioctl_enum_input,
+	.vidioc_g_input = uvc_ioctl_g_input,
+	.vidioc_s_input = uvc_ioctl_s_input,
+	.vidioc_queryctrl = uvc_ioctl_queryctrl,
+	.vidioc_query_ext_ctrl = uvc_ioctl_query_ext_ctrl,
+	.vidioc_g_ctrl = uvc_ioctl_g_ctrl,
+	.vidioc_s_ctrl = uvc_ioctl_s_ctrl,
+	.vidioc_g_ext_ctrls = uvc_ioctl_g_ext_ctrls,
+	.vidioc_s_ext_ctrls = uvc_ioctl_s_ext_ctrls,
+	.vidioc_try_ext_ctrls = uvc_ioctl_try_ext_ctrls,
+	.vidioc_querymenu = uvc_ioctl_querymenu,
+	.vidioc_g_selection = uvc_ioctl_g_selection,
+	.vidioc_g_parm = uvc_ioctl_g_parm,
+	.vidioc_s_parm = uvc_ioctl_s_parm,
+	.vidioc_enum_framesizes = uvc_ioctl_enum_framesizes,
+	.vidioc_enum_frameintervals = uvc_ioctl_enum_frameintervals,
+	.vidioc_subscribe_event = uvc_ioctl_subscribe_event,
+	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
+	.vidioc_default = uvc_ioctl_default,
+};
+
+const struct v4l2_file_operations uvc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= uvc_v4l2_open,
+	.release	= uvc_v4l2_release,
+	.unlocked_ioctl	= video_ioctl2,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl32	= uvc_v4l2_compat_ioctl32,
+#endif
+	.read		= uvc_v4l2_read,
+	.mmap		= uvc_v4l2_mmap,
+	.poll		= uvc_v4l2_poll,
+#ifndef CONFIG_MMU
+	.get_unmapped_area = uvc_v4l2_get_unmapped_area,
+#endif
+};
+
diff --git a/kernel/drivers/media/usb/uvc/uvc_video.c b/kernel/drivers/media/usb/uvc/uvc_video.c
new file mode 100644
index 000000000..20ccc9d31
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_video.c
@@ -0,0 +1,1907 @@
+/*
+ *      uvc_video.c  --  USB Video Class driver - Video handling
+ *
+ *      Copyright (C) 2005-2010
+ *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/videodev2.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <linux/atomic.h>
+#include <asm/unaligned.h>
+
+#include <media/v4l2-common.h>
+
+#include "uvcvideo.h"
+
+/* ------------------------------------------------------------------------
+ * UVC Controls
+ */
+
+static int __uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
+			__u8 intfnum, __u8 cs, void *data, __u16 size,
+			int timeout)
+{
+	__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
+	unsigned int pipe;
+
+	pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
+			      : usb_sndctrlpipe(dev->udev, 0);
+	type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
+
+	return usb_control_msg(dev->udev, pipe, query, type, cs << 8,
+			unit << 8 | intfnum, data, size, timeout);
+}
+
+static const char *uvc_query_name(__u8 query)
+{
+	switch (query) {
+	case UVC_SET_CUR:
+		return "SET_CUR";
+	case UVC_GET_CUR:
+		return "GET_CUR";
+	case UVC_GET_MIN:
+		return "GET_MIN";
+	case UVC_GET_MAX:
+		return "GET_MAX";
+	case UVC_GET_RES:
+		return "GET_RES";
+	case UVC_GET_LEN:
+		return "GET_LEN";
+	case UVC_GET_INFO:
+		return "GET_INFO";
+	case UVC_GET_DEF:
+		return "GET_DEF";
+	default:
+		return "<invalid>";
+	}
+}
+
+int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
+			__u8 intfnum, __u8 cs, void *data, __u16 size)
+{
+	int ret;
+
+	ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
+				UVC_CTRL_CONTROL_TIMEOUT);
+	if (ret != size) {
+		uvc_printk(KERN_ERR, "Failed to query (%s) UVC control %u on "
+			"unit %u: %d (exp. %u).\n", uvc_query_name(query), cs,
+			unit, ret, size);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void uvc_fixup_video_ctrl(struct uvc_streaming *stream,
+	struct uvc_streaming_control *ctrl)
+{
+	struct uvc_format *format = NULL;
+	struct uvc_frame *frame = NULL;
+	unsigned int i;
+
+	for (i = 0; i < stream->nformats; ++i) {
+		if (stream->format[i].index == ctrl->bFormatIndex) {
+			format = &stream->format[i];
+			break;
+		}
+	}
+
+	if (format == NULL)
+		return;
+
+	for (i = 0; i < format->nframes; ++i) {
+		if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) {
+			frame = &format->frame[i];
+			break;
+		}
+	}
+
+	if (frame == NULL)
+		return;
+
+	if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
+	     (ctrl->dwMaxVideoFrameSize == 0 &&
+	      stream->dev->uvc_version < 0x0110))
+		ctrl->dwMaxVideoFrameSize =
+			frame->dwMaxVideoFrameBufferSize;
+
+	if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) &&
+	    stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH &&
+	    stream->intf->num_altsetting > 1) {
+		u32 interval;
+		u32 bandwidth;
+
+		interval = (ctrl->dwFrameInterval > 100000)
+			 ? ctrl->dwFrameInterval
+			 : frame->dwFrameInterval[0];
+
+		/* Compute a bandwidth estimation by multiplying the frame
+		 * size by the number of video frames per second, divide the
+		 * result by the number of USB frames (or micro-frames for
+		 * high-speed devices) per second and add the UVC header size
+		 * (assumed to be 12 bytes long).
+		 */
+		bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp;
+		bandwidth *= 10000000 / interval + 1;
+		bandwidth /= 1000;
+		if (stream->dev->udev->speed == USB_SPEED_HIGH)
+			bandwidth /= 8;
+		bandwidth += 12;
+
+		/* The bandwidth estimate is too low for many cameras. Don't use
+		 * maximum packet sizes lower than 1024 bytes to try and work
+		 * around the problem. According to measurements done on two
+		 * different camera models, the value is high enough to get most
+		 * resolutions working while not preventing two simultaneous
+		 * VGA streams at 15 fps.
+		 */
+		bandwidth = max_t(u32, bandwidth, 1024);
+
+		ctrl->dwMaxPayloadTransferSize = bandwidth;
+	}
+}
+
+static int uvc_get_video_ctrl(struct uvc_streaming *stream,
+	struct uvc_streaming_control *ctrl, int probe, __u8 query)
+{
+	__u8 *data;
+	__u16 size;
+	int ret;
+
+	size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
+	if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
+			query == UVC_GET_DEF)
+		return -EIO;
+
+	data = kmalloc(size, GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
+		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
+		size, uvc_timeout_param);
+
+	if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) {
+		/* Some cameras, mostly based on Bison Electronics chipsets,
+		 * answer a GET_MIN or GET_MAX request with the wCompQuality
+		 * field only.
+		 */
+		uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non "
+			"compliance - GET_MIN/MAX(PROBE) incorrectly "
+			"supported. Enabling workaround.\n");
+		memset(ctrl, 0, sizeof *ctrl);
+		ctrl->wCompQuality = le16_to_cpup((__le16 *)data);
+		ret = 0;
+		goto out;
+	} else if (query == UVC_GET_DEF && probe == 1 && ret != size) {
+		/* Many cameras don't support the GET_DEF request on their
+		 * video probe control. Warn once and return, the caller will
+		 * fall back to GET_CUR.
+		 */
+		uvc_warn_once(stream->dev, UVC_WARN_PROBE_DEF, "UVC non "
+			"compliance - GET_DEF(PROBE) not supported. "
+			"Enabling workaround.\n");
+		ret = -EIO;
+		goto out;
+	} else if (ret != size) {
+		uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : "
+			"%d (exp. %u).\n", query, probe ? "probe" : "commit",
+			ret, size);
+		ret = -EIO;
+		goto out;
+	}
+
+	ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
+	ctrl->bFormatIndex = data[2];
+	ctrl->bFrameIndex = data[3];
+	ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
+	ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
+	ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
+	ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
+	ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
+	ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
+	ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]);
+	ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]);
+
+	if (size == 34) {
+		ctrl->dwClockFrequency = get_unaligned_le32(&data[26]);
+		ctrl->bmFramingInfo = data[30];
+		ctrl->bPreferedVersion = data[31];
+		ctrl->bMinVersion = data[32];
+		ctrl->bMaxVersion = data[33];
+	} else {
+		ctrl->dwClockFrequency = stream->dev->clock_frequency;
+		ctrl->bmFramingInfo = 0;
+		ctrl->bPreferedVersion = 0;
+		ctrl->bMinVersion = 0;
+		ctrl->bMaxVersion = 0;
+	}
+
+	/* Some broken devices return null or wrong dwMaxVideoFrameSize and
+	 * dwMaxPayloadTransferSize fields. Try to get the value from the
+	 * format and frame descriptors.
+	 */
+	uvc_fixup_video_ctrl(stream, ctrl);
+	ret = 0;
+
+out:
+	kfree(data);
+	return ret;
+}
+
+static int uvc_set_video_ctrl(struct uvc_streaming *stream,
+	struct uvc_streaming_control *ctrl, int probe)
+{
+	__u8 *data;
+	__u16 size;
+	int ret;
+
+	size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
+	data = kzalloc(size, GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	*(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
+	data[2] = ctrl->bFormatIndex;
+	data[3] = ctrl->bFrameIndex;
+	*(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
+	*(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
+	*(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
+	*(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
+	*(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
+	*(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
+	put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
+	put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
+
+	if (size == 34) {
+		put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
+		data[30] = ctrl->bmFramingInfo;
+		data[31] = ctrl->bPreferedVersion;
+		data[32] = ctrl->bMinVersion;
+		data[33] = ctrl->bMaxVersion;
+	}
+
+	ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum,
+		probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
+		size, uvc_timeout_param);
+	if (ret != size) {
+		uvc_printk(KERN_ERR, "Failed to set UVC %s control : "
+			"%d (exp. %u).\n", probe ? "probe" : "commit",
+			ret, size);
+		ret = -EIO;
+	}
+
+	kfree(data);
+	return ret;
+}
+
+int uvc_probe_video(struct uvc_streaming *stream,
+	struct uvc_streaming_control *probe)
+{
+	struct uvc_streaming_control probe_min, probe_max;
+	__u16 bandwidth;
+	unsigned int i;
+	int ret;
+
+	/* Perform probing. The device should adjust the requested values
+	 * according to its capabilities. However, some devices, namely the
+	 * first generation UVC Logitech webcams, don't implement the Video
+	 * Probe control properly, and just return the needed bandwidth. For
+	 * that reason, if the needed bandwidth exceeds the maximum available
+	 * bandwidth, try to lower the quality.
+	 */
+	ret = uvc_set_video_ctrl(stream, probe, 1);
+	if (ret < 0)
+		goto done;
+
+	/* Get the minimum and maximum values for compression settings. */
+	if (!(stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) {
+		ret = uvc_get_video_ctrl(stream, &probe_min, 1, UVC_GET_MIN);
+		if (ret < 0)
+			goto done;
+		ret = uvc_get_video_ctrl(stream, &probe_max, 1, UVC_GET_MAX);
+		if (ret < 0)
+			goto done;
+
+		probe->wCompQuality = probe_max.wCompQuality;
+	}
+
+	for (i = 0; i < 2; ++i) {
+		ret = uvc_set_video_ctrl(stream, probe, 1);
+		if (ret < 0)
+			goto done;
+		ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
+		if (ret < 0)
+			goto done;
+
+		if (stream->intf->num_altsetting == 1)
+			break;
+
+		bandwidth = probe->dwMaxPayloadTransferSize;
+		if (bandwidth <= stream->maxpsize)
+			break;
+
+		if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
+			ret = -ENOSPC;
+			goto done;
+		}
+
+		/* TODO: negotiate compression parameters */
+		probe->wKeyFrameRate = probe_min.wKeyFrameRate;
+		probe->wPFrameRate = probe_min.wPFrameRate;
+		probe->wCompQuality = probe_max.wCompQuality;
+		probe->wCompWindowSize = probe_min.wCompWindowSize;
+	}
+
+done:
+	return ret;
+}
+
+static int uvc_commit_video(struct uvc_streaming *stream,
+			    struct uvc_streaming_control *probe)
+{
+	return uvc_set_video_ctrl(stream, probe, 0);
+}
+
+/* -----------------------------------------------------------------------------
+ * Clocks and timestamps
+ */
+
+static inline void uvc_video_get_ts(struct timespec *ts)
+{
+	if (uvc_clock_param == CLOCK_MONOTONIC)
+		ktime_get_ts(ts);
+	else
+		ktime_get_real_ts(ts);
+}
+
+static void
+uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
+		       const __u8 *data, int len)
+{
+	struct uvc_clock_sample *sample;
+	unsigned int header_size;
+	bool has_pts = false;
+	bool has_scr = false;
+	unsigned long flags;
+	struct timespec ts;
+	u16 host_sof;
+	u16 dev_sof;
+
+	switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) {
+	case UVC_STREAM_PTS | UVC_STREAM_SCR:
+		header_size = 12;
+		has_pts = true;
+		has_scr = true;
+		break;
+	case UVC_STREAM_PTS:
+		header_size = 6;
+		has_pts = true;
+		break;
+	case UVC_STREAM_SCR:
+		header_size = 8;
+		has_scr = true;
+		break;
+	default:
+		header_size = 2;
+		break;
+	}
+
+	/* Check for invalid headers. */
+	if (len < header_size)
+		return;
+
+	/* Extract the timestamps:
+	 *
+	 * - store the frame PTS in the buffer structure
+	 * - if the SCR field is present, retrieve the host SOF counter and
+	 *   kernel timestamps and store them with the SCR STC and SOF fields
+	 *   in the ring buffer
+	 */
+	if (has_pts && buf != NULL)
+		buf->pts = get_unaligned_le32(&data[2]);
+
+	if (!has_scr)
+		return;
+
+	/* To limit the amount of data, drop SCRs with an SOF identical to the
+	 * previous one.
+	 */
+	dev_sof = get_unaligned_le16(&data[header_size - 2]);
+	if (dev_sof == stream->clock.last_sof)
+		return;
+
+	stream->clock.last_sof = dev_sof;
+
+	host_sof = usb_get_current_frame_number(stream->dev->udev);
+	uvc_video_get_ts(&ts);
+
+	/* The UVC specification allows device implementations that can't obtain
+	 * the USB frame number to keep their own frame counters as long as they
+	 * match the size and frequency of the frame number associated with USB
+	 * SOF tokens. The SOF values sent by such devices differ from the USB
+	 * SOF tokens by a fixed offset that needs to be estimated and accounted
+	 * for to make timestamp recovery as accurate as possible.
+	 *
+	 * The offset is estimated the first time a device SOF value is received
+	 * as the difference between the host and device SOF values. As the two
+	 * SOF values can differ slightly due to transmission delays, consider
+	 * that the offset is null if the difference is not higher than 10 ms
+	 * (negative differences can not happen and are thus considered as an
+	 * offset). The video commit control wDelay field should be used to
+	 * compute a dynamic threshold instead of using a fixed 10 ms value, but
+	 * devices don't report reliable wDelay values.
+	 *
+	 * See uvc_video_clock_host_sof() for an explanation regarding why only
+	 * the 8 LSBs of the delta are kept.
+	 */
+	if (stream->clock.sof_offset == (u16)-1) {
+		u16 delta_sof = (host_sof - dev_sof) & 255;
+		if (delta_sof >= 10)
+			stream->clock.sof_offset = delta_sof;
+		else
+			stream->clock.sof_offset = 0;
+	}
+
+	dev_sof = (dev_sof + stream->clock.sof_offset) & 2047;
+
+	spin_lock_irqsave(&stream->clock.lock, flags);
+
+	sample = &stream->clock.samples[stream->clock.head];
+	sample->dev_stc = get_unaligned_le32(&data[header_size - 6]);
+	sample->dev_sof = dev_sof;
+	sample->host_sof = host_sof;
+	sample->host_ts = ts;
+
+	/* Update the sliding window head and count. */
+	stream->clock.head = (stream->clock.head + 1) % stream->clock.size;
+
+	if (stream->clock.count < stream->clock.size)
+		stream->clock.count++;
+
+	spin_unlock_irqrestore(&stream->clock.lock, flags);
+}
+
+static void uvc_video_clock_reset(struct uvc_streaming *stream)
+{
+	struct uvc_clock *clock = &stream->clock;
+
+	clock->head = 0;
+	clock->count = 0;
+	clock->last_sof = -1;
+	clock->sof_offset = -1;
+}
+
+static int uvc_video_clock_init(struct uvc_streaming *stream)
+{
+	struct uvc_clock *clock = &stream->clock;
+
+	spin_lock_init(&clock->lock);
+	clock->size = 32;
+
+	clock->samples = kmalloc(clock->size * sizeof(*clock->samples),
+				 GFP_KERNEL);
+	if (clock->samples == NULL)
+		return -ENOMEM;
+
+	uvc_video_clock_reset(stream);
+
+	return 0;
+}
+
+static void uvc_video_clock_cleanup(struct uvc_streaming *stream)
+{
+	kfree(stream->clock.samples);
+	stream->clock.samples = NULL;
+}
+
+/*
+ * uvc_video_clock_host_sof - Return the host SOF value for a clock sample
+ *
+ * Host SOF counters reported by usb_get_current_frame_number() usually don't
+ * cover the whole 11-bits SOF range (0-2047) but are limited to the HCI frame
+ * schedule window. They can be limited to 8, 9 or 10 bits depending on the host
+ * controller and its configuration.
+ *
+ * We thus need to recover the SOF value corresponding to the host frame number.
+ * As the device and host frame numbers are sampled in a short interval, the
+ * difference between their values should be equal to a small delta plus an
+ * integer multiple of 256 caused by the host frame number limited precision.
+ *
+ * To obtain the recovered host SOF value, compute the small delta by masking
+ * the high bits of the host frame counter and device SOF difference and add it
+ * to the device SOF value.
+ */
+static u16 uvc_video_clock_host_sof(const struct uvc_clock_sample *sample)
+{
+	/* The delta value can be negative. */
+	s8 delta_sof;
+
+	delta_sof = (sample->host_sof - sample->dev_sof) & 255;
+
+	return (sample->dev_sof + delta_sof) & 2047;
+}
+
+/*
+ * uvc_video_clock_update - Update the buffer timestamp
+ *
+ * This function converts the buffer PTS timestamp to the host clock domain by
+ * going through the USB SOF clock domain and stores the result in the V4L2
+ * buffer timestamp field.
+ *
+ * The relationship between the device clock and the host clock isn't known.
+ * However, the device and the host share the common USB SOF clock which can be
+ * used to recover that relationship.
+ *
+ * The relationship between the device clock and the USB SOF clock is considered
+ * to be linear over the clock samples sliding window and is given by
+ *
+ * SOF = m * PTS + p
+ *
+ * Several methods to compute the slope (m) and intercept (p) can be used. As
+ * the clock drift should be small compared to the sliding window size, we
+ * assume that the line that goes through the points at both ends of the window
+ * is a good approximation. Naming those points P1 and P2, we get
+ *
+ * SOF = (SOF2 - SOF1) / (STC2 - STC1) * PTS
+ *     + (SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1)
+ *
+ * or
+ *
+ * SOF = ((SOF2 - SOF1) * PTS + SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1)   (1)
+ *
+ * to avoid losing precision in the division. Similarly, the host timestamp is
+ * computed with
+ *
+ * TS = ((TS2 - TS1) * PTS + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1)	     (2)
+ *
+ * SOF values are coded on 11 bits by USB. We extend their precision with 16
+ * decimal bits, leading to a 11.16 coding.
+ *
+ * TODO: To avoid surprises with device clock values, PTS/STC timestamps should
+ * be normalized using the nominal device clock frequency reported through the
+ * UVC descriptors.
+ *
+ * Both the PTS/STC and SOF counters roll over, after a fixed but device
+ * specific amount of time for PTS/STC and after 2048ms for SOF. As long as the
+ * sliding window size is smaller than the rollover period, differences computed
+ * on unsigned integers will produce the correct result. However, the p term in
+ * the linear relations will be miscomputed.
+ *
+ * To fix the issue, we subtract a constant from the PTS and STC values to bring
+ * PTS to half the 32 bit STC range. The sliding window STC values then fit into
+ * the 32 bit range without any rollover.
+ *
+ * Similarly, we add 2048 to the device SOF values to make sure that the SOF
+ * computed by (1) will never be smaller than 0. This offset is then compensated
+ * by adding 2048 to the SOF values used in (2). However, this doesn't prevent
+ * rollovers between (1) and (2): the SOF value computed by (1) can be slightly
+ * lower than 4096, and the host SOF counters can have rolled over to 2048. This
+ * case is handled by subtracting 2048 from the SOF value if it exceeds the host
+ * SOF value at the end of the sliding window.
+ *
+ * Finally we subtract a constant from the host timestamps to bring the first
+ * timestamp of the sliding window to 1s.
+ */
+void uvc_video_clock_update(struct uvc_streaming *stream,
+			    struct v4l2_buffer *v4l2_buf,
+			    struct uvc_buffer *buf)
+{
+	struct uvc_clock *clock = &stream->clock;
+	struct uvc_clock_sample *first;
+	struct uvc_clock_sample *last;
+	unsigned long flags;
+	struct timespec ts;
+	u32 delta_stc;
+	u32 y1, y2;
+	u32 x1, x2;
+	u32 mean;
+	u32 sof;
+	u32 div;
+	u32 rem;
+	u64 y;
+
+	spin_lock_irqsave(&clock->lock, flags);
+
+	if (clock->count < clock->size)
+		goto done;
+
+	first = &clock->samples[clock->head];
+	last = &clock->samples[(clock->head - 1) % clock->size];
+
+	/* First step, PTS to SOF conversion. */
+	delta_stc = buf->pts - (1UL << 31);
+	x1 = first->dev_stc - delta_stc;
+	x2 = last->dev_stc - delta_stc;
+	if (x1 == x2)
+		goto done;
+
+	y1 = (first->dev_sof + 2048) << 16;
+	y2 = (last->dev_sof + 2048) << 16;
+	if (y2 < y1)
+		y2 += 2048 << 16;
+
+	y = (u64)(y2 - y1) * (1ULL << 31) + (u64)y1 * (u64)x2
+	  - (u64)y2 * (u64)x1;
+	y = div_u64(y, x2 - x1);
+
+	sof = y;
+
+	uvc_trace(UVC_TRACE_CLOCK, "%s: PTS %u y %llu.%06llu SOF %u.%06llu "
+		  "(x1 %u x2 %u y1 %u y2 %u SOF offset %u)\n",
+		  stream->dev->name, buf->pts,
+		  y >> 16, div_u64((y & 0xffff) * 1000000, 65536),
+		  sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),
+		  x1, x2, y1, y2, clock->sof_offset);
+
+	/* Second step, SOF to host clock conversion. */
+	x1 = (uvc_video_clock_host_sof(first) + 2048) << 16;
+	x2 = (uvc_video_clock_host_sof(last) + 2048) << 16;
+	if (x2 < x1)
+		x2 += 2048 << 16;
+	if (x1 == x2)
+		goto done;
+
+	ts = timespec_sub(last->host_ts, first->host_ts);
+	y1 = NSEC_PER_SEC;
+	y2 = (ts.tv_sec + 1) * NSEC_PER_SEC + ts.tv_nsec;
+
+	/* Interpolated and host SOF timestamps can wrap around at slightly
+	 * different times. Handle this by adding or removing 2048 to or from
+	 * the computed SOF value to keep it close to the SOF samples mean
+	 * value.
+	 */
+	mean = (x1 + x2) / 2;
+	if (mean - (1024 << 16) > sof)
+		sof += 2048 << 16;
+	else if (sof > mean + (1024 << 16))
+		sof -= 2048 << 16;
+
+	y = (u64)(y2 - y1) * (u64)sof + (u64)y1 * (u64)x2
+	  - (u64)y2 * (u64)x1;
+	y = div_u64(y, x2 - x1);
+
+	div = div_u64_rem(y, NSEC_PER_SEC, &rem);
+	ts.tv_sec = first->host_ts.tv_sec - 1 + div;
+	ts.tv_nsec = first->host_ts.tv_nsec + rem;
+	if (ts.tv_nsec >= NSEC_PER_SEC) {
+		ts.tv_sec++;
+		ts.tv_nsec -= NSEC_PER_SEC;
+	}
+
+	uvc_trace(UVC_TRACE_CLOCK, "%s: SOF %u.%06llu y %llu ts %lu.%06lu "
+		  "buf ts %lu.%06lu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %u)\n",
+		  stream->dev->name,
+		  sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),
+		  y, ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC,
+		  v4l2_buf->timestamp.tv_sec,
+		  (unsigned long)v4l2_buf->timestamp.tv_usec,
+		  x1, first->host_sof, first->dev_sof,
+		  x2, last->host_sof, last->dev_sof, y1, y2);
+
+	/* Update the V4L2 buffer. */
+	v4l2_buf->timestamp.tv_sec = ts.tv_sec;
+	v4l2_buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
+
+done:
+	spin_unlock_irqrestore(&stream->clock.lock, flags);
+}
+
+/* ------------------------------------------------------------------------
+ * Stream statistics
+ */
+
+static void uvc_video_stats_decode(struct uvc_streaming *stream,
+		const __u8 *data, int len)
+{
+	unsigned int header_size;
+	bool has_pts = false;
+	bool has_scr = false;
+	u16 uninitialized_var(scr_sof);
+	u32 uninitialized_var(scr_stc);
+	u32 uninitialized_var(pts);
+
+	if (stream->stats.stream.nb_frames == 0 &&
+	    stream->stats.frame.nb_packets == 0)
+		ktime_get_ts(&stream->stats.stream.start_ts);
+
+	switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) {
+	case UVC_STREAM_PTS | UVC_STREAM_SCR:
+		header_size = 12;
+		has_pts = true;
+		has_scr = true;
+		break;
+	case UVC_STREAM_PTS:
+		header_size = 6;
+		has_pts = true;
+		break;
+	case UVC_STREAM_SCR:
+		header_size = 8;
+		has_scr = true;
+		break;
+	default:
+		header_size = 2;
+		break;
+	}
+
+	/* Check for invalid headers. */
+	if (len < header_size || data[0] < header_size) {
+		stream->stats.frame.nb_invalid++;
+		return;
+	}
+
+	/* Extract the timestamps. */
+	if (has_pts)
+		pts = get_unaligned_le32(&data[2]);
+
+	if (has_scr) {
+		scr_stc = get_unaligned_le32(&data[header_size - 6]);
+		scr_sof = get_unaligned_le16(&data[header_size - 2]);
+	}
+
+	/* Is PTS constant through the whole frame ? */
+	if (has_pts && stream->stats.frame.nb_pts) {
+		if (stream->stats.frame.pts != pts) {
+			stream->stats.frame.nb_pts_diffs++;
+			stream->stats.frame.last_pts_diff =
+				stream->stats.frame.nb_packets;
+		}
+	}
+
+	if (has_pts) {
+		stream->stats.frame.nb_pts++;
+		stream->stats.frame.pts = pts;
+	}
+
+	/* Do all frames have a PTS in their first non-empty packet, or before
+	 * their first empty packet ?
+	 */
+	if (stream->stats.frame.size == 0) {
+		if (len > header_size)
+			stream->stats.frame.has_initial_pts = has_pts;
+		if (len == header_size && has_pts)
+			stream->stats.frame.has_early_pts = true;
+	}
+
+	/* Do the SCR.STC and SCR.SOF fields vary through the frame ? */
+	if (has_scr && stream->stats.frame.nb_scr) {
+		if (stream->stats.frame.scr_stc != scr_stc)
+			stream->stats.frame.nb_scr_diffs++;
+	}
+
+	if (has_scr) {
+		/* Expand the SOF counter to 32 bits and store its value. */
+		if (stream->stats.stream.nb_frames > 0 ||
+		    stream->stats.frame.nb_scr > 0)
+			stream->stats.stream.scr_sof_count +=
+				(scr_sof - stream->stats.stream.scr_sof) % 2048;
+		stream->stats.stream.scr_sof = scr_sof;
+
+		stream->stats.frame.nb_scr++;
+		stream->stats.frame.scr_stc = scr_stc;
+		stream->stats.frame.scr_sof = scr_sof;
+
+		if (scr_sof < stream->stats.stream.min_sof)
+			stream->stats.stream.min_sof = scr_sof;
+		if (scr_sof > stream->stats.stream.max_sof)
+			stream->stats.stream.max_sof = scr_sof;
+	}
+
+	/* Record the first non-empty packet number. */
+	if (stream->stats.frame.size == 0 && len > header_size)
+		stream->stats.frame.first_data = stream->stats.frame.nb_packets;
+
+	/* Update the frame size. */
+	stream->stats.frame.size += len - header_size;
+
+	/* Update the packets counters. */
+	stream->stats.frame.nb_packets++;
+	if (len > header_size)
+		stream->stats.frame.nb_empty++;
+
+	if (data[1] & UVC_STREAM_ERR)
+		stream->stats.frame.nb_errors++;
+}
+
+static void uvc_video_stats_update(struct uvc_streaming *stream)
+{
+	struct uvc_stats_frame *frame = &stream->stats.frame;
+
+	uvc_trace(UVC_TRACE_STATS, "frame %u stats: %u/%u/%u packets, "
+		  "%u/%u/%u pts (%searly %sinitial), %u/%u scr, "
+		  "last pts/stc/sof %u/%u/%u\n",
+		  stream->sequence, frame->first_data,
+		  frame->nb_packets - frame->nb_empty, frame->nb_packets,
+		  frame->nb_pts_diffs, frame->last_pts_diff, frame->nb_pts,
+		  frame->has_early_pts ? "" : "!",
+		  frame->has_initial_pts ? "" : "!",
+		  frame->nb_scr_diffs, frame->nb_scr,
+		  frame->pts, frame->scr_stc, frame->scr_sof);
+
+	stream->stats.stream.nb_frames++;
+	stream->stats.stream.nb_packets += stream->stats.frame.nb_packets;
+	stream->stats.stream.nb_empty += stream->stats.frame.nb_empty;
+	stream->stats.stream.nb_errors += stream->stats.frame.nb_errors;
+	stream->stats.stream.nb_invalid += stream->stats.frame.nb_invalid;
+
+	if (frame->has_early_pts)
+		stream->stats.stream.nb_pts_early++;
+	if (frame->has_initial_pts)
+		stream->stats.stream.nb_pts_initial++;
+	if (frame->last_pts_diff <= frame->first_data)
+		stream->stats.stream.nb_pts_constant++;
+	if (frame->nb_scr >= frame->nb_packets - frame->nb_empty)
+		stream->stats.stream.nb_scr_count_ok++;
+	if (frame->nb_scr_diffs + 1 == frame->nb_scr)
+		stream->stats.stream.nb_scr_diffs_ok++;
+
+	memset(&stream->stats.frame, 0, sizeof(stream->stats.frame));
+}
+
+size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf,
+			    size_t size)
+{
+	unsigned int scr_sof_freq;
+	unsigned int duration;
+	struct timespec ts;
+	size_t count = 0;
+
+	ts.tv_sec = stream->stats.stream.stop_ts.tv_sec
+		  - stream->stats.stream.start_ts.tv_sec;
+	ts.tv_nsec = stream->stats.stream.stop_ts.tv_nsec
+		   - stream->stats.stream.start_ts.tv_nsec;
+	if (ts.tv_nsec < 0) {
+		ts.tv_sec--;
+		ts.tv_nsec += 1000000000;
+	}
+
+	/* Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF
+	 * frequency this will not overflow before more than 1h.
+	 */
+	duration = ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
+	if (duration != 0)
+		scr_sof_freq = stream->stats.stream.scr_sof_count * 1000
+			     / duration;
+	else
+		scr_sof_freq = 0;
+
+	count += scnprintf(buf + count, size - count,
+			   "frames:  %u\npackets: %u\nempty:   %u\n"
+			   "errors:  %u\ninvalid: %u\n",
+			   stream->stats.stream.nb_frames,
+			   stream->stats.stream.nb_packets,
+			   stream->stats.stream.nb_empty,
+			   stream->stats.stream.nb_errors,
+			   stream->stats.stream.nb_invalid);
+	count += scnprintf(buf + count, size - count,
+			   "pts: %u early, %u initial, %u ok\n",
+			   stream->stats.stream.nb_pts_early,
+			   stream->stats.stream.nb_pts_initial,
+			   stream->stats.stream.nb_pts_constant);
+	count += scnprintf(buf + count, size - count,
+			   "scr: %u count ok, %u diff ok\n",
+			   stream->stats.stream.nb_scr_count_ok,
+			   stream->stats.stream.nb_scr_diffs_ok);
+	count += scnprintf(buf + count, size - count,
+			   "sof: %u <= sof <= %u, freq %u.%03u kHz\n",
+			   stream->stats.stream.min_sof,
+			   stream->stats.stream.max_sof,
+			   scr_sof_freq / 1000, scr_sof_freq % 1000);
+
+	return count;
+}
+
+static void uvc_video_stats_start(struct uvc_streaming *stream)
+{
+	memset(&stream->stats, 0, sizeof(stream->stats));
+	stream->stats.stream.min_sof = 2048;
+}
+
+static void uvc_video_stats_stop(struct uvc_streaming *stream)
+{
+	ktime_get_ts(&stream->stats.stream.stop_ts);
+}
+
+/* ------------------------------------------------------------------------
+ * Video codecs
+ */
+
+/* Video payload decoding is handled by uvc_video_decode_start(),
+ * uvc_video_decode_data() and uvc_video_decode_end().
+ *
+ * uvc_video_decode_start is called with URB data at the start of a bulk or
+ * isochronous payload. It processes header data and returns the header size
+ * in bytes if successful. If an error occurs, it returns a negative error
+ * code. The following error codes have special meanings.
+ *
+ * - EAGAIN informs the caller that the current video buffer should be marked
+ *   as done, and that the function should be called again with the same data
+ *   and a new video buffer. This is used when end of frame conditions can be
+ *   reliably detected at the beginning of the next frame only.
+ *
+ * If an error other than -EAGAIN is returned, the caller will drop the current
+ * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
+ * made until the next payload. -ENODATA can be used to drop the current
+ * payload if no other error code is appropriate.
+ *
+ * uvc_video_decode_data is called for every URB with URB data. It copies the
+ * data to the video buffer.
+ *
+ * uvc_video_decode_end is called with header data at the end of a bulk or
+ * isochronous payload. It performs any additional header data processing and
+ * returns 0 or a negative error code if an error occurred. As header data have
+ * already been processed by uvc_video_decode_start, this functions isn't
+ * required to perform sanity checks a second time.
+ *
+ * For isochronous transfers where a payload is always transferred in a single
+ * URB, the three functions will be called in a row.
+ *
+ * To let the decoder process header data and update its internal state even
+ * when no video buffer is available, uvc_video_decode_start must be prepared
+ * to be called with a NULL buf parameter. uvc_video_decode_data and
+ * uvc_video_decode_end will never be called with a NULL buffer.
+ */
+static int uvc_video_decode_start(struct uvc_streaming *stream,
+		struct uvc_buffer *buf, const __u8 *data, int len)
+{
+	__u8 fid;
+
+	/* Sanity checks:
+	 * - packet must be at least 2 bytes long
+	 * - bHeaderLength value must be at least 2 bytes (see above)
+	 * - bHeaderLength value can't be larger than the packet size.
+	 */
+	if (len < 2 || data[0] < 2 || data[0] > len) {
+		stream->stats.frame.nb_invalid++;
+		return -EINVAL;
+	}
+
+	fid = data[1] & UVC_STREAM_FID;
+
+	/* Increase the sequence number regardless of any buffer states, so
+	 * that discontinuous sequence numbers always indicate lost frames.
+	 */
+	if (stream->last_fid != fid) {
+		stream->sequence++;
+		if (stream->sequence)
+			uvc_video_stats_update(stream);
+	}
+
+	uvc_video_clock_decode(stream, buf, data, len);
+	uvc_video_stats_decode(stream, data, len);
+
+	/* Store the payload FID bit and return immediately when the buffer is
+	 * NULL.
+	 */
+	if (buf == NULL) {
+		stream->last_fid = fid;
+		return -ENODATA;
+	}
+
+	/* Mark the buffer as bad if the error bit is set. */
+	if (data[1] & UVC_STREAM_ERR) {
+		uvc_trace(UVC_TRACE_FRAME, "Marking buffer as bad (error bit "
+			  "set).\n");
+		buf->error = 1;
+	}
+
+	/* Synchronize to the input stream by waiting for the FID bit to be
+	 * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
+	 * stream->last_fid is initialized to -1, so the first isochronous
+	 * frame will always be in sync.
+	 *
+	 * If the device doesn't toggle the FID bit, invert stream->last_fid
+	 * when the EOF bit is set to force synchronisation on the next packet.
+	 */
+	if (buf->state != UVC_BUF_STATE_ACTIVE) {
+		struct timespec ts;
+
+		if (fid == stream->last_fid) {
+			uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
+				"sync).\n");
+			if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&
+			    (data[1] & UVC_STREAM_EOF))
+				stream->last_fid ^= UVC_STREAM_FID;
+			return -ENODATA;
+		}
+
+		uvc_video_get_ts(&ts);
+
+		buf->buf.v4l2_buf.field = V4L2_FIELD_NONE;
+		buf->buf.v4l2_buf.sequence = stream->sequence;
+		buf->buf.v4l2_buf.timestamp.tv_sec = ts.tv_sec;
+		buf->buf.v4l2_buf.timestamp.tv_usec =
+			ts.tv_nsec / NSEC_PER_USEC;
+
+		/* TODO: Handle PTS and SCR. */
+		buf->state = UVC_BUF_STATE_ACTIVE;
+	}
+
+	/* Mark the buffer as done if we're at the beginning of a new frame.
+	 * End of frame detection is better implemented by checking the EOF
+	 * bit (FID bit toggling is delayed by one frame compared to the EOF
+	 * bit), but some devices don't set the bit at end of frame (and the
+	 * last payload can be lost anyway). We thus must check if the FID has
+	 * been toggled.
+	 *
+	 * stream->last_fid is initialized to -1, so the first isochronous
+	 * frame will never trigger an end of frame detection.
+	 *
+	 * Empty buffers (bytesused == 0) don't trigger end of frame detection
+	 * as it doesn't make sense to return an empty buffer. This also
+	 * avoids detecting end of frame conditions at FID toggling if the
+	 * previous payload had the EOF bit set.
+	 */
+	if (fid != stream->last_fid && buf->bytesused != 0) {
+		uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
+				"toggled).\n");
+		buf->state = UVC_BUF_STATE_READY;
+		return -EAGAIN;
+	}
+
+	stream->last_fid = fid;
+
+	return data[0];
+}
+
+static void uvc_video_decode_data(struct uvc_streaming *stream,
+		struct uvc_buffer *buf, const __u8 *data, int len)
+{
+	unsigned int maxlen, nbytes;
+	void *mem;
+
+	if (len <= 0)
+		return;
+
+	/* Copy the video data to the buffer. */
+	maxlen = buf->length - buf->bytesused;
+	mem = buf->mem + buf->bytesused;
+	nbytes = min((unsigned int)len, maxlen);
+	memcpy(mem, data, nbytes);
+	buf->bytesused += nbytes;
+
+	/* Complete the current frame if the buffer size was exceeded. */
+	if (len > maxlen) {
+		uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
+		buf->state = UVC_BUF_STATE_READY;
+	}
+}
+
+static void uvc_video_decode_end(struct uvc_streaming *stream,
+		struct uvc_buffer *buf, const __u8 *data, int len)
+{
+	/* Mark the buffer as done if the EOF marker is set. */
+	if (data[1] & UVC_STREAM_EOF && buf->bytesused != 0) {
+		uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
+		if (data[0] == len)
+			uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
+		buf->state = UVC_BUF_STATE_READY;
+		if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
+			stream->last_fid ^= UVC_STREAM_FID;
+	}
+}
+
+/* Video payload encoding is handled by uvc_video_encode_header() and
+ * uvc_video_encode_data(). Only bulk transfers are currently supported.
+ *
+ * uvc_video_encode_header is called at the start of a payload. It adds header
+ * data to the transfer buffer and returns the header size. As the only known
+ * UVC output device transfers a whole frame in a single payload, the EOF bit
+ * is always set in the header.
+ *
+ * uvc_video_encode_data is called for every URB and copies the data from the
+ * video buffer to the transfer buffer.
+ */
+static int uvc_video_encode_header(struct uvc_streaming *stream,
+		struct uvc_buffer *buf, __u8 *data, int len)
+{
+	data[0] = 2;	/* Header length */
+	data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF
+		| (stream->last_fid & UVC_STREAM_FID);
+	return 2;
+}
+
+static int uvc_video_encode_data(struct uvc_streaming *stream,
+		struct uvc_buffer *buf, __u8 *data, int len)
+{
+	struct uvc_video_queue *queue = &stream->queue;
+	unsigned int nbytes;
+	void *mem;
+
+	/* Copy video data to the URB buffer. */
+	mem = buf->mem + queue->buf_used;
+	nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used);
+	nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size,
+			nbytes);
+	memcpy(data, mem, nbytes);
+
+	queue->buf_used += nbytes;
+
+	return nbytes;
+}
+
+/* ------------------------------------------------------------------------
+ * URB handling
+ */
+
+/*
+ * Set error flag for incomplete buffer.
+ */
+static void uvc_video_validate_buffer(const struct uvc_streaming *stream,
+				      struct uvc_buffer *buf)
+{
+	if (stream->ctrl.dwMaxVideoFrameSize != buf->bytesused &&
+	    !(stream->cur_format->flags & UVC_FMT_FLAG_COMPRESSED))
+		buf->error = 1;
+}
+
+/*
+ * Completion handler for video URBs.
+ */
+static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream,
+	struct uvc_buffer *buf)
+{
+	u8 *mem;
+	int ret, i;
+
+	for (i = 0; i < urb->number_of_packets; ++i) {
+		if (urb->iso_frame_desc[i].status < 0) {
+			uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
+				"lost (%d).\n", urb->iso_frame_desc[i].status);
+			/* Mark the buffer as faulty. */
+			if (buf != NULL)
+				buf->error = 1;
+			continue;
+		}
+
+		/* Decode the payload header. */
+		mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
+		do {
+			ret = uvc_video_decode_start(stream, buf, mem,
+				urb->iso_frame_desc[i].actual_length);
+			if (ret == -EAGAIN) {
+				uvc_video_validate_buffer(stream, buf);
+				buf = uvc_queue_next_buffer(&stream->queue,
+							    buf);
+			}
+		} while (ret == -EAGAIN);
+
+		if (ret < 0)
+			continue;
+
+		/* Decode the payload data. */
+		uvc_video_decode_data(stream, buf, mem + ret,
+			urb->iso_frame_desc[i].actual_length - ret);
+
+		/* Process the header again. */
+		uvc_video_decode_end(stream, buf, mem,
+			urb->iso_frame_desc[i].actual_length);
+
+		if (buf->state == UVC_BUF_STATE_READY) {
+			uvc_video_validate_buffer(stream, buf);
+			buf = uvc_queue_next_buffer(&stream->queue, buf);
+		}
+	}
+}
+
+static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream,
+	struct uvc_buffer *buf)
+{
+	u8 *mem;
+	int len, ret;
+
+	/*
+	 * Ignore ZLPs if they're not part of a frame, otherwise process them
+	 * to trigger the end of payload detection.
+	 */
+	if (urb->actual_length == 0 && stream->bulk.header_size == 0)
+		return;
+
+	mem = urb->transfer_buffer;
+	len = urb->actual_length;
+	stream->bulk.payload_size += len;
+
+	/* If the URB is the first of its payload, decode and save the
+	 * header.
+	 */
+	if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) {
+		do {
+			ret = uvc_video_decode_start(stream, buf, mem, len);
+			if (ret == -EAGAIN)
+				buf = uvc_queue_next_buffer(&stream->queue,
+							    buf);
+		} while (ret == -EAGAIN);
+
+		/* If an error occurred skip the rest of the payload. */
+		if (ret < 0 || buf == NULL) {
+			stream->bulk.skip_payload = 1;
+		} else {
+			memcpy(stream->bulk.header, mem, ret);
+			stream->bulk.header_size = ret;
+
+			mem += ret;
+			len -= ret;
+		}
+	}
+
+	/* The buffer queue might have been cancelled while a bulk transfer
+	 * was in progress, so we can reach here with buf equal to NULL. Make
+	 * sure buf is never dereferenced if NULL.
+	 */
+
+	/* Process video data. */
+	if (!stream->bulk.skip_payload && buf != NULL)
+		uvc_video_decode_data(stream, buf, mem, len);
+
+	/* Detect the payload end by a URB smaller than the maximum size (or
+	 * a payload size equal to the maximum) and process the header again.
+	 */
+	if (urb->actual_length < urb->transfer_buffer_length ||
+	    stream->bulk.payload_size >= stream->bulk.max_payload_size) {
+		if (!stream->bulk.skip_payload && buf != NULL) {
+			uvc_video_decode_end(stream, buf, stream->bulk.header,
+				stream->bulk.payload_size);
+			if (buf->state == UVC_BUF_STATE_READY)
+				buf = uvc_queue_next_buffer(&stream->queue,
+							    buf);
+		}
+
+		stream->bulk.header_size = 0;
+		stream->bulk.skip_payload = 0;
+		stream->bulk.payload_size = 0;
+	}
+}
+
+static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream,
+	struct uvc_buffer *buf)
+{
+	u8 *mem = urb->transfer_buffer;
+	int len = stream->urb_size, ret;
+
+	if (buf == NULL) {
+		urb->transfer_buffer_length = 0;
+		return;
+	}
+
+	/* If the URB is the first of its payload, add the header. */
+	if (stream->bulk.header_size == 0) {
+		ret = uvc_video_encode_header(stream, buf, mem, len);
+		stream->bulk.header_size = ret;
+		stream->bulk.payload_size += ret;
+		mem += ret;
+		len -= ret;
+	}
+
+	/* Process video data. */
+	ret = uvc_video_encode_data(stream, buf, mem, len);
+
+	stream->bulk.payload_size += ret;
+	len -= ret;
+
+	if (buf->bytesused == stream->queue.buf_used ||
+	    stream->bulk.payload_size == stream->bulk.max_payload_size) {
+		if (buf->bytesused == stream->queue.buf_used) {
+			stream->queue.buf_used = 0;
+			buf->state = UVC_BUF_STATE_READY;
+			buf->buf.v4l2_buf.sequence = ++stream->sequence;
+			uvc_queue_next_buffer(&stream->queue, buf);
+			stream->last_fid ^= UVC_STREAM_FID;
+		}
+
+		stream->bulk.header_size = 0;
+		stream->bulk.payload_size = 0;
+	}
+
+	urb->transfer_buffer_length = stream->urb_size - len;
+}
+
+static void uvc_video_complete(struct urb *urb)
+{
+	struct uvc_streaming *stream = urb->context;
+	struct uvc_video_queue *queue = &stream->queue;
+	struct uvc_buffer *buf = NULL;
+	unsigned long flags;
+	int ret;
+
+	switch (urb->status) {
+	case 0:
+		break;
+
+	default:
+		uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
+			"completion handler.\n", urb->status);
+
+	case -ENOENT:		/* usb_kill_urb() called. */
+		if (stream->frozen)
+			return;
+
+	case -ECONNRESET:	/* usb_unlink_urb() called. */
+	case -ESHUTDOWN:	/* The endpoint is being disabled. */
+		uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
+		return;
+	}
+
+	spin_lock_irqsave(&queue->irqlock, flags);
+	if (!list_empty(&queue->irqqueue))
+		buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
+				       queue);
+	spin_unlock_irqrestore(&queue->irqlock, flags);
+
+	stream->decode(urb, stream, buf);
+
+	if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
+		uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
+			ret);
+	}
+}
+
+/*
+ * Free transfer buffers.
+ */
+static void uvc_free_urb_buffers(struct uvc_streaming *stream)
+{
+	unsigned int i;
+
+	for (i = 0; i < UVC_URBS; ++i) {
+		if (stream->urb_buffer[i]) {
+#ifndef CONFIG_DMA_NONCOHERENT
+			usb_free_coherent(stream->dev->udev, stream->urb_size,
+				stream->urb_buffer[i], stream->urb_dma[i]);
+#else
+			kfree(stream->urb_buffer[i]);
+#endif
+			stream->urb_buffer[i] = NULL;
+		}
+	}
+
+	stream->urb_size = 0;
+}
+
+/*
+ * Allocate transfer buffers. This function can be called with buffers
+ * already allocated when resuming from suspend, in which case it will
+ * return without touching the buffers.
+ *
+ * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the
+ * system is too low on memory try successively smaller numbers of packets
+ * until allocation succeeds.
+ *
+ * Return the number of allocated packets on success or 0 when out of memory.
+ */
+static int uvc_alloc_urb_buffers(struct uvc_streaming *stream,
+	unsigned int size, unsigned int psize, gfp_t gfp_flags)
+{
+	unsigned int npackets;
+	unsigned int i;
+
+	/* Buffers are already allocated, bail out. */
+	if (stream->urb_size)
+		return stream->urb_size / psize;
+
+	/* Compute the number of packets. Bulk endpoints might transfer UVC
+	 * payloads across multiple URBs.
+	 */
+	npackets = DIV_ROUND_UP(size, psize);
+	if (npackets > UVC_MAX_PACKETS)
+		npackets = UVC_MAX_PACKETS;
+
+	/* Retry allocations until one succeed. */
+	for (; npackets > 1; npackets /= 2) {
+		for (i = 0; i < UVC_URBS; ++i) {
+			stream->urb_size = psize * npackets;
+#ifndef CONFIG_DMA_NONCOHERENT
+			stream->urb_buffer[i] = usb_alloc_coherent(
+				stream->dev->udev, stream->urb_size,
+				gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]);
+#else
+			stream->urb_buffer[i] =
+			    kmalloc(stream->urb_size, gfp_flags | __GFP_NOWARN);
+#endif
+			if (!stream->urb_buffer[i]) {
+				uvc_free_urb_buffers(stream);
+				break;
+			}
+		}
+
+		if (i == UVC_URBS) {
+			uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB buffers "
+				"of %ux%u bytes each.\n", UVC_URBS, npackets,
+				psize);
+			return npackets;
+		}
+	}
+
+	uvc_trace(UVC_TRACE_VIDEO, "Failed to allocate URB buffers (%u bytes "
+		"per packet).\n", psize);
+	return 0;
+}
+
+/*
+ * Uninitialize isochronous/bulk URBs and free transfer buffers.
+ */
+static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers)
+{
+	struct urb *urb;
+	unsigned int i;
+
+	uvc_video_stats_stop(stream);
+
+	for (i = 0; i < UVC_URBS; ++i) {
+		urb = stream->urb[i];
+		if (urb == NULL)
+			continue;
+
+		usb_kill_urb(urb);
+		usb_free_urb(urb);
+		stream->urb[i] = NULL;
+	}
+
+	if (free_buffers)
+		uvc_free_urb_buffers(stream);
+}
+
+/*
+ * Compute the maximum number of bytes per interval for an endpoint.
+ */
+static unsigned int uvc_endpoint_max_bpi(struct usb_device *dev,
+					 struct usb_host_endpoint *ep)
+{
+	u16 psize;
+
+	switch (dev->speed) {
+	case USB_SPEED_SUPER:
+		return le16_to_cpu(ep->ss_ep_comp.wBytesPerInterval);
+	case USB_SPEED_HIGH:
+		psize = usb_endpoint_maxp(&ep->desc);
+		return (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
+	case USB_SPEED_WIRELESS:
+		psize = usb_endpoint_maxp(&ep->desc);
+		return psize;
+	default:
+		psize = usb_endpoint_maxp(&ep->desc);
+		return psize & 0x07ff;
+	}
+}
+
+/*
+ * Initialize isochronous URBs and allocate transfer buffers. The packet size
+ * is given by the endpoint.
+ */
+static int uvc_init_video_isoc(struct uvc_streaming *stream,
+	struct usb_host_endpoint *ep, gfp_t gfp_flags)
+{
+	struct urb *urb;
+	unsigned int npackets, i, j;
+	u16 psize;
+	u32 size;
+
+	psize = uvc_endpoint_max_bpi(stream->dev->udev, ep);
+	size = stream->ctrl.dwMaxVideoFrameSize;
+
+	npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
+	if (npackets == 0)
+		return -ENOMEM;
+
+	size = npackets * psize;
+
+	for (i = 0; i < UVC_URBS; ++i) {
+		urb = usb_alloc_urb(npackets, gfp_flags);
+		if (urb == NULL) {
+			uvc_uninit_video(stream, 1);
+			return -ENOMEM;
+		}
+
+		urb->dev = stream->dev->udev;
+		urb->context = stream;
+		urb->pipe = usb_rcvisocpipe(stream->dev->udev,
+				ep->desc.bEndpointAddress);
+#ifndef CONFIG_DMA_NONCOHERENT
+		urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
+		urb->transfer_dma = stream->urb_dma[i];
+#else
+		urb->transfer_flags = URB_ISO_ASAP;
+#endif
+		urb->interval = ep->desc.bInterval;
+		urb->transfer_buffer = stream->urb_buffer[i];
+		urb->complete = uvc_video_complete;
+		urb->number_of_packets = npackets;
+		urb->transfer_buffer_length = size;
+
+		for (j = 0; j < npackets; ++j) {
+			urb->iso_frame_desc[j].offset = j * psize;
+			urb->iso_frame_desc[j].length = psize;
+		}
+
+		stream->urb[i] = urb;
+	}
+
+	return 0;
+}
+
+/*
+ * Initialize bulk URBs and allocate transfer buffers. The packet size is
+ * given by the endpoint.
+ */
+static int uvc_init_video_bulk(struct uvc_streaming *stream,
+	struct usb_host_endpoint *ep, gfp_t gfp_flags)
+{
+	struct urb *urb;
+	unsigned int npackets, pipe, i;
+	u16 psize;
+	u32 size;
+
+	psize = usb_endpoint_maxp(&ep->desc) & 0x7ff;
+	size = stream->ctrl.dwMaxPayloadTransferSize;
+	stream->bulk.max_payload_size = size;
+
+	npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags);
+	if (npackets == 0)
+		return -ENOMEM;
+
+	size = npackets * psize;
+
+	if (usb_endpoint_dir_in(&ep->desc))
+		pipe = usb_rcvbulkpipe(stream->dev->udev,
+				       ep->desc.bEndpointAddress);
+	else
+		pipe = usb_sndbulkpipe(stream->dev->udev,
+				       ep->desc.bEndpointAddress);
+
+	if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
+		size = 0;
+
+	for (i = 0; i < UVC_URBS; ++i) {
+		urb = usb_alloc_urb(0, gfp_flags);
+		if (urb == NULL) {
+			uvc_uninit_video(stream, 1);
+			return -ENOMEM;
+		}
+
+		usb_fill_bulk_urb(urb, stream->dev->udev, pipe,
+			stream->urb_buffer[i], size, uvc_video_complete,
+			stream);
+#ifndef CONFIG_DMA_NONCOHERENT
+		urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
+		urb->transfer_dma = stream->urb_dma[i];
+#endif
+
+		stream->urb[i] = urb;
+	}
+
+	return 0;
+}
+
+/*
+ * Initialize isochronous/bulk URBs and allocate transfer buffers.
+ */
+static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags)
+{
+	struct usb_interface *intf = stream->intf;
+	struct usb_host_endpoint *ep;
+	unsigned int i;
+	int ret;
+
+	stream->sequence = -1;
+	stream->last_fid = -1;
+	stream->bulk.header_size = 0;
+	stream->bulk.skip_payload = 0;
+	stream->bulk.payload_size = 0;
+
+	uvc_video_stats_start(stream);
+
+	if (intf->num_altsetting > 1) {
+		struct usb_host_endpoint *best_ep = NULL;
+		unsigned int best_psize = UINT_MAX;
+		unsigned int bandwidth;
+		unsigned int uninitialized_var(altsetting);
+		int intfnum = stream->intfnum;
+
+		/* Isochronous endpoint, select the alternate setting. */
+		bandwidth = stream->ctrl.dwMaxPayloadTransferSize;
+
+		if (bandwidth == 0) {
+			uvc_trace(UVC_TRACE_VIDEO, "Device requested null "
+				"bandwidth, defaulting to lowest.\n");
+			bandwidth = 1;
+		} else {
+			uvc_trace(UVC_TRACE_VIDEO, "Device requested %u "
+				"B/frame bandwidth.\n", bandwidth);
+		}
+
+		for (i = 0; i < intf->num_altsetting; ++i) {
+			struct usb_host_interface *alts;
+			unsigned int psize;
+
+			alts = &intf->altsetting[i];
+			ep = uvc_find_endpoint(alts,
+				stream->header.bEndpointAddress);
+			if (ep == NULL)
+				continue;
+
+			/* Check if the bandwidth is high enough. */
+			psize = uvc_endpoint_max_bpi(stream->dev->udev, ep);
+			if (psize >= bandwidth && psize <= best_psize) {
+				altsetting = alts->desc.bAlternateSetting;
+				best_psize = psize;
+				best_ep = ep;
+			}
+		}
+
+		if (best_ep == NULL) {
+			uvc_trace(UVC_TRACE_VIDEO, "No fast enough alt setting "
+				"for requested bandwidth.\n");
+			return -EIO;
+		}
+
+		uvc_trace(UVC_TRACE_VIDEO, "Selecting alternate setting %u "
+			"(%u B/frame bandwidth).\n", altsetting, best_psize);
+
+		ret = usb_set_interface(stream->dev->udev, intfnum, altsetting);
+		if (ret < 0)
+			return ret;
+
+		ret = uvc_init_video_isoc(stream, best_ep, gfp_flags);
+	} else {
+		/* Bulk endpoint, proceed to URB initialization. */
+		ep = uvc_find_endpoint(&intf->altsetting[0],
+				stream->header.bEndpointAddress);
+		if (ep == NULL)
+			return -EIO;
+
+		ret = uvc_init_video_bulk(stream, ep, gfp_flags);
+	}
+
+	if (ret < 0)
+		return ret;
+
+	/* Submit the URBs. */
+	for (i = 0; i < UVC_URBS; ++i) {
+		ret = usb_submit_urb(stream->urb[i], gfp_flags);
+		if (ret < 0) {
+			uvc_printk(KERN_ERR, "Failed to submit URB %u "
+					"(%d).\n", i, ret);
+			uvc_uninit_video(stream, 1);
+			return ret;
+		}
+	}
+
+	/* The Logitech C920 temporarily forgets that it should not be adjusting
+	 * Exposure Absolute during init so restore controls to stored values.
+	 */
+	if (stream->dev->quirks & UVC_QUIRK_RESTORE_CTRLS_ON_INIT)
+		uvc_ctrl_restore_values(stream->dev);
+
+	return 0;
+}
+
+/* --------------------------------------------------------------------------
+ * Suspend/resume
+ */
+
+/*
+ * Stop streaming without disabling the video queue.
+ *
+ * To let userspace applications resume without trouble, we must not touch the
+ * video buffers in any way. We mark the device as frozen to make sure the URB
+ * completion handler won't try to cancel the queue when we kill the URBs.
+ */
+int uvc_video_suspend(struct uvc_streaming *stream)
+{
+	if (!uvc_queue_streaming(&stream->queue))
+		return 0;
+
+	stream->frozen = 1;
+	uvc_uninit_video(stream, 0);
+	usb_set_interface(stream->dev->udev, stream->intfnum, 0);
+	return 0;
+}
+
+/*
+ * Reconfigure the video interface and restart streaming if it was enabled
+ * before suspend.
+ *
+ * If an error occurs, disable the video queue. This will wake all pending
+ * buffers, making sure userspace applications are notified of the problem
+ * instead of waiting forever.
+ */
+int uvc_video_resume(struct uvc_streaming *stream, int reset)
+{
+	int ret;
+
+	/* If the bus has been reset on resume, set the alternate setting to 0.
+	 * This should be the default value, but some devices crash or otherwise
+	 * misbehave if they don't receive a SET_INTERFACE request before any
+	 * other video control request.
+	 */
+	if (reset)
+		usb_set_interface(stream->dev->udev, stream->intfnum, 0);
+
+	stream->frozen = 0;
+
+	uvc_video_clock_reset(stream);
+
+	if (!uvc_queue_streaming(&stream->queue))
+		return 0;
+
+	ret = uvc_commit_video(stream, &stream->ctrl);
+	if (ret < 0)
+		return ret;
+
+	return uvc_init_video(stream, GFP_NOIO);
+}
+
+/* ------------------------------------------------------------------------
+ * Video device
+ */
+
+/*
+ * Initialize the UVC video device by switching to alternate setting 0 and
+ * retrieve the default format.
+ *
+ * Some cameras (namely the Fuji Finepix) set the format and frame
+ * indexes to zero. The UVC standard doesn't clearly make this a spec
+ * violation, so try to silently fix the values if possible.
+ *
+ * This function is called before registering the device with V4L.
+ */
+int uvc_video_init(struct uvc_streaming *stream)
+{
+	struct uvc_streaming_control *probe = &stream->ctrl;
+	struct uvc_format *format = NULL;
+	struct uvc_frame *frame = NULL;
+	unsigned int i;
+	int ret;
+
+	if (stream->nformats == 0) {
+		uvc_printk(KERN_INFO, "No supported video formats found.\n");
+		return -EINVAL;
+	}
+
+	atomic_set(&stream->active, 0);
+
+	/* Alternate setting 0 should be the default, yet the XBox Live Vision
+	 * Cam (and possibly other devices) crash or otherwise misbehave if
+	 * they don't receive a SET_INTERFACE request before any other video
+	 * control request.
+	 */
+	usb_set_interface(stream->dev->udev, stream->intfnum, 0);
+
+	/* Set the streaming probe control with default streaming parameters
+	 * retrieved from the device. Webcams that don't suport GET_DEF
+	 * requests on the probe control will just keep their current streaming
+	 * parameters.
+	 */
+	if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0)
+		uvc_set_video_ctrl(stream, probe, 1);
+
+	/* Initialize the streaming parameters with the probe control current
+	 * value. This makes sure SET_CUR requests on the streaming commit
+	 * control will always use values retrieved from a successful GET_CUR
+	 * request on the probe control, as required by the UVC specification.
+	 */
+	ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR);
+	if (ret < 0)
+		return ret;
+
+	/* Check if the default format descriptor exists. Use the first
+	 * available format otherwise.
+	 */
+	for (i = stream->nformats; i > 0; --i) {
+		format = &stream->format[i-1];
+		if (format->index == probe->bFormatIndex)
+			break;
+	}
+
+	if (format->nframes == 0) {
+		uvc_printk(KERN_INFO, "No frame descriptor found for the "
+			"default format.\n");
+		return -EINVAL;
+	}
+
+	/* Zero bFrameIndex might be correct. Stream-based formats (including
+	 * MPEG-2 TS and DV) do not support frames but have a dummy frame
+	 * descriptor with bFrameIndex set to zero. If the default frame
+	 * descriptor is not found, use the first available frame.
+	 */
+	for (i = format->nframes; i > 0; --i) {
+		frame = &format->frame[i-1];
+		if (frame->bFrameIndex == probe->bFrameIndex)
+			break;
+	}
+
+	probe->bFormatIndex = format->index;
+	probe->bFrameIndex = frame->bFrameIndex;
+
+	stream->def_format = format;
+	stream->cur_format = format;
+	stream->cur_frame = frame;
+
+	/* Select the video decoding function */
+	if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
+		if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
+			stream->decode = uvc_video_decode_isight;
+		else if (stream->intf->num_altsetting > 1)
+			stream->decode = uvc_video_decode_isoc;
+		else
+			stream->decode = uvc_video_decode_bulk;
+	} else {
+		if (stream->intf->num_altsetting == 1)
+			stream->decode = uvc_video_encode_bulk;
+		else {
+			uvc_printk(KERN_INFO, "Isochronous endpoints are not "
+				"supported for video output devices.\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Enable or disable the video stream.
+ */
+int uvc_video_enable(struct uvc_streaming *stream, int enable)
+{
+	int ret;
+
+	if (!enable) {
+		uvc_uninit_video(stream, 1);
+		if (stream->intf->num_altsetting > 1) {
+			usb_set_interface(stream->dev->udev,
+					  stream->intfnum, 0);
+		} else {
+			/* UVC doesn't specify how to inform a bulk-based device
+			 * when the video stream is stopped. Windows sends a
+			 * CLEAR_FEATURE(HALT) request to the video streaming
+			 * bulk endpoint, mimic the same behaviour.
+			 */
+			unsigned int epnum = stream->header.bEndpointAddress
+					   & USB_ENDPOINT_NUMBER_MASK;
+			unsigned int dir = stream->header.bEndpointAddress
+					 & USB_ENDPOINT_DIR_MASK;
+			unsigned int pipe;
+
+			pipe = usb_sndbulkpipe(stream->dev->udev, epnum) | dir;
+			usb_clear_halt(stream->dev->udev, pipe);
+		}
+
+		uvc_video_clock_cleanup(stream);
+		return 0;
+	}
+
+	ret = uvc_video_clock_init(stream);
+	if (ret < 0)
+		return ret;
+
+	/* Commit the streaming parameters. */
+	ret = uvc_commit_video(stream, &stream->ctrl);
+	if (ret < 0)
+		goto error_commit;
+
+	ret = uvc_init_video(stream, GFP_KERNEL);
+	if (ret < 0)
+		goto error_video;
+
+	return 0;
+
+error_video:
+	usb_set_interface(stream->dev->udev, stream->intfnum, 0);
+error_commit:
+	uvc_video_clock_cleanup(stream);
+
+	return ret;
+}
diff --git a/kernel/drivers/media/usb/uvc/uvcvideo.h b/kernel/drivers/media/usb/uvc/uvcvideo.h
new file mode 100644
index 000000000..1b594c203
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvcvideo.h
@@ -0,0 +1,746 @@
+#ifndef _USB_VIDEO_H_
+#define _USB_VIDEO_H_
+
+#ifndef __KERNEL__
+#error "The uvcvideo.h header is deprecated, use linux/uvcvideo.h instead."
+#endif /* __KERNEL__ */
+
+#include <linux/kernel.h>
+#include <linux/poll.h>
+#include <linux/usb.h>
+#include <linux/usb/video.h>
+#include <linux/uvcvideo.h>
+#include <linux/videodev2.h>
+#include <media/media-device.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-fh.h>
+#include <media/videobuf2-core.h>
+
+/* --------------------------------------------------------------------------
+ * UVC constants
+ */
+
+#define UVC_TERM_INPUT			0x0000
+#define UVC_TERM_OUTPUT			0x8000
+#define UVC_TERM_DIRECTION(term)	((term)->type & 0x8000)
+
+#define UVC_ENTITY_TYPE(entity)		((entity)->type & 0x7fff)
+#define UVC_ENTITY_IS_UNIT(entity)	(((entity)->type & 0xff00) == 0)
+#define UVC_ENTITY_IS_TERM(entity)	(((entity)->type & 0xff00) != 0)
+#define UVC_ENTITY_IS_ITERM(entity) \
+	(UVC_ENTITY_IS_TERM(entity) && \
+	((entity)->type & 0x8000) == UVC_TERM_INPUT)
+#define UVC_ENTITY_IS_OTERM(entity) \
+	(UVC_ENTITY_IS_TERM(entity) && \
+	((entity)->type & 0x8000) == UVC_TERM_OUTPUT)
+
+
+/* ------------------------------------------------------------------------
+ * GUIDs
+ */
+#define UVC_GUID_UVC_CAMERA \
+	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01}
+#define UVC_GUID_UVC_OUTPUT \
+	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02}
+#define UVC_GUID_UVC_MEDIA_TRANSPORT_INPUT \
+	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03}
+#define UVC_GUID_UVC_PROCESSING \
+	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01}
+#define UVC_GUID_UVC_SELECTOR \
+	{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
+	 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02}
+
+#define UVC_GUID_FORMAT_MJPEG \
+	{ 'M',  'J',  'P',  'G', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_YUY2 \
+	{ 'Y',  'U',  'Y',  '2', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_YUY2_ISIGHT \
+	{ 'Y',  'U',  'Y',  '2', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0x00, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_NV12 \
+	{ 'N',  'V',  '1',  '2', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_YV12 \
+	{ 'Y',  'V',  '1',  '2', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_I420 \
+	{ 'I',  '4',  '2',  '0', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_UYVY \
+	{ 'U',  'Y',  'V',  'Y', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_Y800 \
+	{ 'Y',  '8',  '0',  '0', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_Y8 \
+	{ 'Y',  '8',  ' ',  ' ', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_Y10 \
+	{ 'Y',  '1',  '0',  ' ', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_Y12 \
+	{ 'Y',  '1',  '2',  ' ', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_Y16 \
+	{ 'Y',  '1',  '6',  ' ', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_BY8 \
+	{ 'B',  'Y',  '8',  ' ', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_BA81 \
+	{ 'B',  'A',  '8',  '1', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_GBRG \
+	{ 'G',  'B',  'R',  'G', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_GRBG \
+	{ 'G',  'R',  'B',  'G', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_RGGB \
+	{ 'R',  'G',  'G',  'B', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_RGBP \
+	{ 'R',  'G',  'B',  'P', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+#define UVC_GUID_FORMAT_BGR3 \
+	{ 0x7d, 0xeb, 0x36, 0xe4, 0x4f, 0x52, 0xce, 0x11, \
+	 0x9f, 0x53, 0x00, 0x20, 0xaf, 0x0b, 0xa7, 0x70}
+#define UVC_GUID_FORMAT_M420 \
+	{ 'M',  '4',  '2',  '0', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+
+#define UVC_GUID_FORMAT_H264 \
+	{ 'H',  '2',  '6',  '4', 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+
+/* ------------------------------------------------------------------------
+ * Driver specific constants.
+ */
+
+#define DRIVER_VERSION		"1.1.1"
+
+/* Number of isochronous URBs. */
+#define UVC_URBS		5
+/* Maximum number of packets per URB. */
+#define UVC_MAX_PACKETS		32
+/* Maximum status buffer size in bytes of interrupt URB. */
+#define UVC_MAX_STATUS_SIZE	16
+
+#define UVC_CTRL_CONTROL_TIMEOUT	300
+#define UVC_CTRL_STREAMING_TIMEOUT	5000
+
+/* Maximum allowed number of control mappings per device */
+#define UVC_MAX_CONTROL_MAPPINGS	1024
+#define UVC_MAX_CONTROL_MENU_ENTRIES	32
+
+/* Devices quirks */
+#define UVC_QUIRK_STATUS_INTERVAL	0x00000001
+#define UVC_QUIRK_PROBE_MINMAX		0x00000002
+#define UVC_QUIRK_PROBE_EXTRAFIELDS	0x00000004
+#define UVC_QUIRK_BUILTIN_ISIGHT	0x00000008
+#define UVC_QUIRK_STREAM_NO_FID		0x00000010
+#define UVC_QUIRK_IGNORE_SELECTOR_UNIT	0x00000020
+#define UVC_QUIRK_FIX_BANDWIDTH		0x00000080
+#define UVC_QUIRK_PROBE_DEF		0x00000100
+#define UVC_QUIRK_RESTRICT_FRAME_RATE	0x00000200
+#define UVC_QUIRK_RESTORE_CTRLS_ON_INIT	0x00000400
+#define UVC_QUIRK_FORCE_Y8		0x00000800
+
+/* Format flags */
+#define UVC_FMT_FLAG_COMPRESSED		0x00000001
+#define UVC_FMT_FLAG_STREAM		0x00000002
+
+/* ------------------------------------------------------------------------
+ * Structures.
+ */
+
+struct uvc_device;
+
+/* TODO: Put the most frequently accessed fields at the beginning of
+ * structures to maximize cache efficiency.
+ */
+struct uvc_control_info {
+	struct list_head mappings;
+
+	__u8 entity[16];
+	__u8 index;	/* Bit index in bmControls */
+	__u8 selector;
+
+	__u16 size;
+	__u32 flags;
+};
+
+struct uvc_control_mapping {
+	struct list_head list;
+	struct list_head ev_subs;
+
+	__u32 id;
+	__u8 name[32];
+	__u8 entity[16];
+	__u8 selector;
+
+	__u8 size;
+	__u8 offset;
+	enum v4l2_ctrl_type v4l2_type;
+	__u32 data_type;
+
+	struct uvc_menu_info *menu_info;
+	__u32 menu_count;
+
+	__u32 master_id;
+	__s32 master_manual;
+	__u32 slave_ids[2];
+
+	__s32 (*get) (struct uvc_control_mapping *mapping, __u8 query,
+		      const __u8 *data);
+	void (*set) (struct uvc_control_mapping *mapping, __s32 value,
+		     __u8 *data);
+};
+
+struct uvc_control {
+	struct uvc_entity *entity;
+	struct uvc_control_info info;
+
+	__u8 index;	/* Used to match the uvc_control entry with a
+			   uvc_control_info. */
+	__u8 dirty:1,
+	     loaded:1,
+	     modified:1,
+	     cached:1,
+	     initialized:1;
+
+	__u8 *uvc_data;
+};
+
+struct uvc_format_desc {
+	char *name;
+	__u8 guid[16];
+	__u32 fcc;
+};
+
+/* The term 'entity' refers to both UVC units and UVC terminals.
+ *
+ * The type field is either the terminal type (wTerminalType in the terminal
+ * descriptor), or the unit type (bDescriptorSubtype in the unit descriptor).
+ * As the bDescriptorSubtype field is one byte long, the type value will
+ * always have a null MSB for units. All terminal types defined by the UVC
+ * specification have a non-null MSB, so it is safe to use the MSB to
+ * differentiate between units and terminals as long as the descriptor parsing
+ * code makes sure terminal types have a non-null MSB.
+ *
+ * For terminals, the type's most significant bit stores the terminal
+ * direction (either UVC_TERM_INPUT or UVC_TERM_OUTPUT). The type field should
+ * always be accessed with the UVC_ENTITY_* macros and never directly.
+ */
+
+#define UVC_ENTITY_FLAG_DEFAULT		(1 << 0)
+
+struct uvc_entity {
+	struct list_head list;		/* Entity as part of a UVC device. */
+	struct list_head chain;		/* Entity as part of a video device
+					 * chain. */
+	unsigned int flags;
+
+	__u8 id;
+	__u16 type;
+	char name[64];
+
+	/* Media controller-related fields. */
+	struct video_device *vdev;
+	struct v4l2_subdev subdev;
+	unsigned int num_pads;
+	unsigned int num_links;
+	struct media_pad *pads;
+
+	union {
+		struct {
+			__u16 wObjectiveFocalLengthMin;
+			__u16 wObjectiveFocalLengthMax;
+			__u16 wOcularFocalLength;
+			__u8  bControlSize;
+			__u8  *bmControls;
+		} camera;
+
+		struct {
+			__u8  bControlSize;
+			__u8  *bmControls;
+			__u8  bTransportModeSize;
+			__u8  *bmTransportModes;
+		} media;
+
+		struct {
+		} output;
+
+		struct {
+			__u16 wMaxMultiplier;
+			__u8  bControlSize;
+			__u8  *bmControls;
+			__u8  bmVideoStandards;
+		} processing;
+
+		struct {
+		} selector;
+
+		struct {
+			__u8  guidExtensionCode[16];
+			__u8  bNumControls;
+			__u8  bControlSize;
+			__u8  *bmControls;
+			__u8  *bmControlsType;
+		} extension;
+	};
+
+	__u8 bNrInPins;
+	__u8 *baSourceID;
+
+	unsigned int ncontrols;
+	struct uvc_control *controls;
+};
+
+struct uvc_frame {
+	__u8  bFrameIndex;
+	__u8  bmCapabilities;
+	__u16 wWidth;
+	__u16 wHeight;
+	__u32 dwMinBitRate;
+	__u32 dwMaxBitRate;
+	__u32 dwMaxVideoFrameBufferSize;
+	__u8  bFrameIntervalType;
+	__u32 dwDefaultFrameInterval;
+	__u32 *dwFrameInterval;
+};
+
+struct uvc_format {
+	__u8 type;
+	__u8 index;
+	__u8 bpp;
+	__u8 colorspace;
+	__u32 fcc;
+	__u32 flags;
+
+	char name[32];
+
+	unsigned int nframes;
+	struct uvc_frame *frame;
+};
+
+struct uvc_streaming_header {
+	__u8 bNumFormats;
+	__u8 bEndpointAddress;
+	__u8 bTerminalLink;
+	__u8 bControlSize;
+	__u8 *bmaControls;
+	/* The following fields are used by input headers only. */
+	__u8 bmInfo;
+	__u8 bStillCaptureMethod;
+	__u8 bTriggerSupport;
+	__u8 bTriggerUsage;
+};
+
+enum uvc_buffer_state {
+	UVC_BUF_STATE_IDLE	= 0,
+	UVC_BUF_STATE_QUEUED	= 1,
+	UVC_BUF_STATE_ACTIVE	= 2,
+	UVC_BUF_STATE_READY	= 3,
+	UVC_BUF_STATE_DONE	= 4,
+	UVC_BUF_STATE_ERROR	= 5,
+};
+
+struct uvc_buffer {
+	struct vb2_buffer buf;
+	struct list_head queue;
+
+	enum uvc_buffer_state state;
+	unsigned int error;
+
+	void *mem;
+	unsigned int length;
+	unsigned int bytesused;
+
+	u32 pts;
+};
+
+#define UVC_QUEUE_DISCONNECTED		(1 << 0)
+#define UVC_QUEUE_DROP_CORRUPTED	(1 << 1)
+
+struct uvc_video_queue {
+	struct vb2_queue queue;
+	struct mutex mutex;			/* Protects queue */
+
+	unsigned int flags;
+	unsigned int buf_used;
+
+	spinlock_t irqlock;			/* Protects irqqueue */
+	struct list_head irqqueue;
+};
+
+struct uvc_video_chain {
+	struct uvc_device *dev;
+	struct list_head list;
+
+	struct list_head entities;		/* All entities */
+	struct uvc_entity *processing;		/* Processing unit */
+	struct uvc_entity *selector;		/* Selector unit */
+
+	struct mutex ctrl_mutex;		/* Protects ctrl.info */
+
+	struct v4l2_prio_state prio;		/* V4L2 priority state */
+	u32 caps;				/* V4L2 chain-wide caps */
+};
+
+struct uvc_stats_frame {
+	unsigned int size;		/* Number of bytes captured */
+	unsigned int first_data;	/* Index of the first non-empty packet */
+
+	unsigned int nb_packets;	/* Number of packets */
+	unsigned int nb_empty;		/* Number of empty packets */
+	unsigned int nb_invalid;	/* Number of packets with an invalid header */
+	unsigned int nb_errors;		/* Number of packets with the error bit set */
+
+	unsigned int nb_pts;		/* Number of packets with a PTS timestamp */
+	unsigned int nb_pts_diffs;	/* Number of PTS differences inside a frame */
+	unsigned int last_pts_diff;	/* Index of the last PTS difference */
+	bool has_initial_pts;		/* Whether the first non-empty packet has a PTS */
+	bool has_early_pts;		/* Whether a PTS is present before the first non-empty packet */
+	u32 pts;			/* PTS of the last packet */
+
+	unsigned int nb_scr;		/* Number of packets with a SCR timestamp */
+	unsigned int nb_scr_diffs;	/* Number of SCR.STC differences inside a frame */
+	u16 scr_sof;			/* SCR.SOF of the last packet */
+	u32 scr_stc;			/* SCR.STC of the last packet */
+};
+
+struct uvc_stats_stream {
+	struct timespec start_ts;	/* Stream start timestamp */
+	struct timespec stop_ts;	/* Stream stop timestamp */
+
+	unsigned int nb_frames;		/* Number of frames */
+
+	unsigned int nb_packets;	/* Number of packets */
+	unsigned int nb_empty;		/* Number of empty packets */
+	unsigned int nb_invalid;	/* Number of packets with an invalid header */
+	unsigned int nb_errors;		/* Number of packets with the error bit set */
+
+	unsigned int nb_pts_constant;	/* Number of frames with constant PTS */
+	unsigned int nb_pts_early;	/* Number of frames with early PTS */
+	unsigned int nb_pts_initial;	/* Number of frames with initial PTS */
+
+	unsigned int nb_scr_count_ok;	/* Number of frames with at least one SCR per non empty packet */
+	unsigned int nb_scr_diffs_ok;	/* Number of frames with varying SCR.STC */
+	unsigned int scr_sof_count;	/* STC.SOF counter accumulated since stream start */
+	unsigned int scr_sof;		/* STC.SOF of the last packet */
+	unsigned int min_sof;		/* Minimum STC.SOF value */
+	unsigned int max_sof;		/* Maximum STC.SOF value */
+};
+
+struct uvc_streaming {
+	struct list_head list;
+	struct uvc_device *dev;
+	struct video_device vdev;
+	struct uvc_video_chain *chain;
+	atomic_t active;
+
+	struct usb_interface *intf;
+	int intfnum;
+	__u16 maxpsize;
+
+	struct uvc_streaming_header header;
+	enum v4l2_buf_type type;
+
+	unsigned int nformats;
+	struct uvc_format *format;
+
+	struct uvc_streaming_control ctrl;
+	struct uvc_format *def_format;
+	struct uvc_format *cur_format;
+	struct uvc_frame *cur_frame;
+
+	/* Protect access to ctrl, cur_format, cur_frame and hardware video
+	 * probe control.
+	 */
+	struct mutex mutex;
+
+	/* Buffers queue. */
+	unsigned int frozen : 1;
+	struct uvc_video_queue queue;
+	void (*decode) (struct urb *urb, struct uvc_streaming *video,
+			struct uvc_buffer *buf);
+
+	/* Context data used by the bulk completion handler. */
+	struct {
+		__u8 header[256];
+		unsigned int header_size;
+		int skip_payload;
+		__u32 payload_size;
+		__u32 max_payload_size;
+	} bulk;
+
+	struct urb *urb[UVC_URBS];
+	char *urb_buffer[UVC_URBS];
+	dma_addr_t urb_dma[UVC_URBS];
+	unsigned int urb_size;
+
+	__u32 sequence;
+	__u8 last_fid;
+
+	/* debugfs */
+	struct dentry *debugfs_dir;
+	struct {
+		struct uvc_stats_frame frame;
+		struct uvc_stats_stream stream;
+	} stats;
+
+	/* Timestamps support. */
+	struct uvc_clock {
+		struct uvc_clock_sample {
+			u32 dev_stc;
+			u16 dev_sof;
+			struct timespec host_ts;
+			u16 host_sof;
+		} *samples;
+
+		unsigned int head;
+		unsigned int count;
+		unsigned int size;
+
+		u16 last_sof;
+		u16 sof_offset;
+
+		spinlock_t lock;
+	} clock;
+};
+
+enum uvc_device_state {
+	UVC_DEV_DISCONNECTED = 1,
+};
+
+struct uvc_device {
+	struct usb_device *udev;
+	struct usb_interface *intf;
+	unsigned long warnings;
+	__u32 quirks;
+	int intfnum;
+	char name[32];
+
+	enum uvc_device_state state;
+	struct mutex lock;		/* Protects users */
+	unsigned int users;
+	atomic_t nmappings;
+
+	/* Video control interface */
+#ifdef CONFIG_MEDIA_CONTROLLER
+	struct media_device mdev;
+#endif
+	struct v4l2_device vdev;
+	__u16 uvc_version;
+	__u32 clock_frequency;
+
+	struct list_head entities;
+	struct list_head chains;
+
+	/* Video Streaming interfaces */
+	struct list_head streams;
+	atomic_t nstreams;
+
+	/* Status Interrupt Endpoint */
+	struct usb_host_endpoint *int_ep;
+	struct urb *int_urb;
+	__u8 *status;
+	struct input_dev *input;
+	char input_phys[64];
+};
+
+enum uvc_handle_state {
+	UVC_HANDLE_PASSIVE	= 0,
+	UVC_HANDLE_ACTIVE	= 1,
+};
+
+struct uvc_fh {
+	struct v4l2_fh vfh;
+	struct uvc_video_chain *chain;
+	struct uvc_streaming *stream;
+	enum uvc_handle_state state;
+};
+
+struct uvc_driver {
+	struct usb_driver driver;
+};
+
+/* ------------------------------------------------------------------------
+ * Debugging, printing and logging
+ */
+
+#define UVC_TRACE_PROBE		(1 << 0)
+#define UVC_TRACE_DESCR		(1 << 1)
+#define UVC_TRACE_CONTROL	(1 << 2)
+#define UVC_TRACE_FORMAT	(1 << 3)
+#define UVC_TRACE_CAPTURE	(1 << 4)
+#define UVC_TRACE_CALLS		(1 << 5)
+#define UVC_TRACE_FRAME		(1 << 7)
+#define UVC_TRACE_SUSPEND	(1 << 8)
+#define UVC_TRACE_STATUS	(1 << 9)
+#define UVC_TRACE_VIDEO		(1 << 10)
+#define UVC_TRACE_STATS		(1 << 11)
+#define UVC_TRACE_CLOCK		(1 << 12)
+
+#define UVC_WARN_MINMAX		0
+#define UVC_WARN_PROBE_DEF	1
+#define UVC_WARN_XU_GET_RES	2
+
+extern unsigned int uvc_clock_param;
+extern unsigned int uvc_no_drop_param;
+extern unsigned int uvc_trace_param;
+extern unsigned int uvc_timeout_param;
+
+#define uvc_trace(flag, msg...) \
+	do { \
+		if (uvc_trace_param & flag) \
+			printk(KERN_DEBUG "uvcvideo: " msg); \
+	} while (0)
+
+#define uvc_warn_once(dev, warn, msg...) \
+	do { \
+		if (!test_and_set_bit(warn, &dev->warnings)) \
+			printk(KERN_INFO "uvcvideo: " msg); \
+	} while (0)
+
+#define uvc_printk(level, msg...) \
+	printk(level "uvcvideo: " msg)
+
+/* --------------------------------------------------------------------------
+ * Internal functions.
+ */
+
+/* Core driver */
+extern struct uvc_driver uvc_driver;
+
+extern struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id);
+
+/* Video buffers queue management. */
+extern int uvc_queue_init(struct uvc_video_queue *queue,
+		enum v4l2_buf_type type, int drop_corrupted);
+extern void uvc_queue_release(struct uvc_video_queue *queue);
+extern int uvc_request_buffers(struct uvc_video_queue *queue,
+		struct v4l2_requestbuffers *rb);
+extern int uvc_query_buffer(struct uvc_video_queue *queue,
+		struct v4l2_buffer *v4l2_buf);
+extern int uvc_create_buffers(struct uvc_video_queue *queue,
+		struct v4l2_create_buffers *v4l2_cb);
+extern int uvc_queue_buffer(struct uvc_video_queue *queue,
+		struct v4l2_buffer *v4l2_buf);
+extern int uvc_dequeue_buffer(struct uvc_video_queue *queue,
+		struct v4l2_buffer *v4l2_buf, int nonblocking);
+extern int uvc_queue_streamon(struct uvc_video_queue *queue,
+			      enum v4l2_buf_type type);
+extern int uvc_queue_streamoff(struct uvc_video_queue *queue,
+			       enum v4l2_buf_type type);
+extern void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect);
+extern struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
+		struct uvc_buffer *buf);
+extern int uvc_queue_mmap(struct uvc_video_queue *queue,
+		struct vm_area_struct *vma);
+extern unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
+		struct file *file, poll_table *wait);
+#ifndef CONFIG_MMU
+extern unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+		unsigned long pgoff);
+#endif
+extern int uvc_queue_allocated(struct uvc_video_queue *queue);
+static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
+{
+	return vb2_is_streaming(&queue->queue);
+}
+
+/* V4L2 interface */
+extern const struct v4l2_ioctl_ops uvc_ioctl_ops;
+extern const struct v4l2_file_operations uvc_fops;
+
+/* Media controller */
+extern int uvc_mc_register_entities(struct uvc_video_chain *chain);
+extern void uvc_mc_cleanup_entity(struct uvc_entity *entity);
+
+/* Video */
+extern int uvc_video_init(struct uvc_streaming *stream);
+extern int uvc_video_suspend(struct uvc_streaming *stream);
+extern int uvc_video_resume(struct uvc_streaming *stream, int reset);
+extern int uvc_video_enable(struct uvc_streaming *stream, int enable);
+extern int uvc_probe_video(struct uvc_streaming *stream,
+		struct uvc_streaming_control *probe);
+extern int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
+		__u8 intfnum, __u8 cs, void *data, __u16 size);
+void uvc_video_clock_update(struct uvc_streaming *stream,
+			    struct v4l2_buffer *v4l2_buf,
+			    struct uvc_buffer *buf);
+
+/* Status */
+extern int uvc_status_init(struct uvc_device *dev);
+extern void uvc_status_cleanup(struct uvc_device *dev);
+extern int uvc_status_start(struct uvc_device *dev, gfp_t flags);
+extern void uvc_status_stop(struct uvc_device *dev);
+
+/* Controls */
+extern const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops;
+
+extern int uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
+		struct v4l2_queryctrl *v4l2_ctrl);
+extern int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
+		struct v4l2_querymenu *query_menu);
+
+extern int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
+		const struct uvc_control_mapping *mapping);
+extern int uvc_ctrl_init_device(struct uvc_device *dev);
+extern void uvc_ctrl_cleanup_device(struct uvc_device *dev);
+extern int uvc_ctrl_restore_values(struct uvc_device *dev);
+
+extern int uvc_ctrl_begin(struct uvc_video_chain *chain);
+extern int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
+			const struct v4l2_ext_control *xctrls,
+			unsigned int xctrls_count);
+static inline int uvc_ctrl_commit(struct uvc_fh *handle,
+			const struct v4l2_ext_control *xctrls,
+			unsigned int xctrls_count)
+{
+	return __uvc_ctrl_commit(handle, 0, xctrls, xctrls_count);
+}
+static inline int uvc_ctrl_rollback(struct uvc_fh *handle)
+{
+	return __uvc_ctrl_commit(handle, 1, NULL, 0);
+}
+
+extern int uvc_ctrl_get(struct uvc_video_chain *chain,
+		struct v4l2_ext_control *xctrl);
+extern int uvc_ctrl_set(struct uvc_video_chain *chain,
+		struct v4l2_ext_control *xctrl);
+
+extern int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
+		struct uvc_xu_control_query *xqry);
+
+/* Utility functions */
+extern void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,
+		unsigned int n_terms, unsigned int threshold);
+extern uint32_t uvc_fraction_to_interval(uint32_t numerator,
+		uint32_t denominator);
+extern struct usb_host_endpoint *uvc_find_endpoint(
+		struct usb_host_interface *alts, __u8 epaddr);
+
+/* Quirks support */
+void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream,
+		struct uvc_buffer *buf);
+
+/* debugfs and statistics */
+int uvc_debugfs_init(void);
+void uvc_debugfs_cleanup(void);
+int uvc_debugfs_init_stream(struct uvc_streaming *stream);
+void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream);
+
+size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf,
+			    size_t size);
+
+#endif