1 files changed, 257 insertions, 0 deletions

diff --git a/kernel/drivers/video/backlight/apple_bl.c b/kernel/drivers/video/backlight/apple_bl.c
new file mode 100644
index 000000000..d84329676
--- /dev/null
+++ b/kernel/drivers/video/backlight/apple_bl.c
@@ -0,0 +1,257 @@
+/*
+ *  Backlight Driver for Intel-based Apples
+ *
+ *  Copyright (c) Red Hat <mjg@redhat.com>
+ *  Based on code from Pommed:
+ *  Copyright (C) 2006 Nicolas Boichat <nicolas @boichat.ch>
+ *  Copyright (C) 2006 Felipe Alfaro Solana <felipe_alfaro @linuxmail.org>
+ *  Copyright (C) 2007 Julien BLACHE <jb@jblache.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This driver triggers SMIs which cause the firmware to change the
+ *  backlight brightness. This is icky in many ways, but it's impractical to
+ *  get at the firmware code in order to figure out what it's actually doing.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <linux/atomic.h>
+#include <linux/apple_bl.h>
+
+static struct backlight_device *apple_backlight_device;
+
+struct hw_data {
+	/* I/O resource to allocate. */
+	unsigned long iostart;
+	unsigned long iolen;
+	/* Backlight operations structure. */
+	const struct backlight_ops backlight_ops;
+	void (*set_brightness)(int);
+};
+
+static const struct hw_data *hw_data;
+
+/* Module parameters. */
+static int debug;
+module_param_named(debug, debug, int, 0644);
+MODULE_PARM_DESC(debug, "Set to one to enable debugging messages.");
+
+/*
+ * Implementation for machines with Intel chipset.
+ */
+static void intel_chipset_set_brightness(int intensity)
+{
+	outb(0x04 | (intensity << 4), 0xb3);
+	outb(0xbf, 0xb2);
+}
+
+static int intel_chipset_send_intensity(struct backlight_device *bd)
+{
+	int intensity = bd->props.brightness;
+
+	if (debug)
+		pr_debug("setting brightness to %d\n", intensity);
+
+	intel_chipset_set_brightness(intensity);
+	return 0;
+}
+
+static int intel_chipset_get_intensity(struct backlight_device *bd)
+{
+	int intensity;
+
+	outb(0x03, 0xb3);
+	outb(0xbf, 0xb2);
+	intensity = inb(0xb3) >> 4;
+
+	if (debug)
+		pr_debug("read brightness of %d\n", intensity);
+
+	return intensity;
+}
+
+static const struct hw_data intel_chipset_data = {
+	.iostart = 0xb2,
+	.iolen = 2,
+	.backlight_ops	= {
+		.options	= BL_CORE_SUSPENDRESUME,
+		.get_brightness	= intel_chipset_get_intensity,
+		.update_status	= intel_chipset_send_intensity,
+	},
+	.set_brightness = intel_chipset_set_brightness,
+};
+
+/*
+ * Implementation for machines with Nvidia chipset.
+ */
+static void nvidia_chipset_set_brightness(int intensity)
+{
+	outb(0x04 | (intensity << 4), 0x52f);
+	outb(0xbf, 0x52e);
+}
+
+static int nvidia_chipset_send_intensity(struct backlight_device *bd)
+{
+	int intensity = bd->props.brightness;
+
+	if (debug)
+		pr_debug("setting brightness to %d\n", intensity);
+
+	nvidia_chipset_set_brightness(intensity);
+	return 0;
+}
+
+static int nvidia_chipset_get_intensity(struct backlight_device *bd)
+{
+	int intensity;
+
+	outb(0x03, 0x52f);
+	outb(0xbf, 0x52e);
+	intensity = inb(0x52f) >> 4;
+
+	if (debug)
+		pr_debug("read brightness of %d\n", intensity);
+
+	return intensity;
+}
+
+static const struct hw_data nvidia_chipset_data = {
+	.iostart = 0x52e,
+	.iolen = 2,
+	.backlight_ops		= {
+		.options	= BL_CORE_SUSPENDRESUME,
+		.get_brightness	= nvidia_chipset_get_intensity,
+		.update_status	= nvidia_chipset_send_intensity
+	},
+	.set_brightness = nvidia_chipset_set_brightness,
+};
+
+static int apple_bl_add(struct acpi_device *dev)
+{
+	struct backlight_properties props;
+	struct pci_dev *host;
+	int intensity;
+
+	host = pci_get_bus_and_slot(0, 0);
+
+	if (!host) {
+		pr_err("unable to find PCI host\n");
+		return -ENODEV;
+	}
+
+	if (host->vendor == PCI_VENDOR_ID_INTEL)
+		hw_data = &intel_chipset_data;
+	else if (host->vendor == PCI_VENDOR_ID_NVIDIA)
+		hw_data = &nvidia_chipset_data;
+
+	pci_dev_put(host);
+
+	if (!hw_data) {
+		pr_err("unknown hardware\n");
+		return -ENODEV;
+	}
+
+	/* Check that the hardware responds - this may not work under EFI */
+
+	intensity = hw_data->backlight_ops.get_brightness(NULL);
+
+	if (!intensity) {
+		hw_data->set_brightness(1);
+		if (!hw_data->backlight_ops.get_brightness(NULL))
+			return -ENODEV;
+
+		hw_data->set_brightness(0);
+	}
+
+	if (!request_region(hw_data->iostart, hw_data->iolen,
+			    "Apple backlight"))
+		return -ENXIO;
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_PLATFORM;
+	props.max_brightness = 15;
+	apple_backlight_device = backlight_device_register("apple_backlight",
+				  NULL, NULL, &hw_data->backlight_ops, &props);
+
+	if (IS_ERR(apple_backlight_device)) {
+		release_region(hw_data->iostart, hw_data->iolen);
+		return PTR_ERR(apple_backlight_device);
+	}
+
+	apple_backlight_device->props.brightness =
+		hw_data->backlight_ops.get_brightness(apple_backlight_device);
+	backlight_update_status(apple_backlight_device);
+
+	return 0;
+}
+
+static int apple_bl_remove(struct acpi_device *dev)
+{
+	backlight_device_unregister(apple_backlight_device);
+
+	release_region(hw_data->iostart, hw_data->iolen);
+	hw_data = NULL;
+	return 0;
+}
+
+static const struct acpi_device_id apple_bl_ids[] = {
+	{"APP0002", 0},
+	{"", 0},
+};
+
+static struct acpi_driver apple_bl_driver = {
+	.name = "Apple backlight",
+	.ids = apple_bl_ids,
+	.ops = {
+		.add = apple_bl_add,
+		.remove = apple_bl_remove,
+	},
+};
+
+static atomic_t apple_bl_registered = ATOMIC_INIT(0);
+
+int apple_bl_register(void)
+{
+	if (atomic_xchg(&apple_bl_registered, 1) == 0)
+		return acpi_bus_register_driver(&apple_bl_driver);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(apple_bl_register);
+
+void apple_bl_unregister(void)
+{
+	if (atomic_xchg(&apple_bl_registered, 0) == 1)
+		acpi_bus_unregister_driver(&apple_bl_driver);
+}
+EXPORT_SYMBOL_GPL(apple_bl_unregister);
+
+static int __init apple_bl_init(void)
+{
+	return apple_bl_register();
+}
+
+static void __exit apple_bl_exit(void)
+{
+	apple_bl_unregister();
+}
+
+module_init(apple_bl_init);
+module_exit(apple_bl_exit);
+
+MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
+MODULE_DESCRIPTION("Apple Backlight Driver");
+MODULE_LICENSE("GPL");
+MODULE_DEVICE_TABLE(acpi, apple_bl_ids);
+MODULE_ALIAS("mbp_nvidia_bl");