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>

1 files changed, 230 insertions, 0 deletions

diff --git a/kernel/drivers/video/backlight/wm831x_bl.c b/kernel/drivers/video/backlight/wm831x_bl.c
new file mode 100644
index 000000000..6eab0d6c2
--- /dev/null
+++ b/kernel/drivers/video/backlight/wm831x_bl.c
@@ -0,0 +1,230 @@
+/*
+ * Backlight driver for Wolfson Microelectronics WM831x PMICs
+ *
+ * Copyright 2009 Wolfson Microelectonics plc
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/slab.h>
+
+#include <linux/mfd/wm831x/core.h>
+#include <linux/mfd/wm831x/pdata.h>
+#include <linux/mfd/wm831x/regulator.h>
+
+struct wm831x_backlight_data {
+	struct wm831x *wm831x;
+	int isink_reg;
+	int current_brightness;
+};
+
+static int wm831x_backlight_set(struct backlight_device *bl, int brightness)
+{
+	struct wm831x_backlight_data *data = bl_get_data(bl);
+	struct wm831x *wm831x = data->wm831x;
+	int power_up = !data->current_brightness && brightness;
+	int power_down = data->current_brightness && !brightness;
+	int ret;
+
+	if (power_up) {
+		/* Enable the ISINK */
+		ret = wm831x_set_bits(wm831x, data->isink_reg,
+				      WM831X_CS1_ENA, WM831X_CS1_ENA);
+		if (ret < 0)
+			goto err;
+
+		/* Enable the DC-DC */
+		ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
+				      WM831X_DC4_ENA, WM831X_DC4_ENA);
+		if (ret < 0)
+			goto err;
+	}
+
+	if (power_down) {
+		/* DCDC first */
+		ret = wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE,
+				      WM831X_DC4_ENA, 0);
+		if (ret < 0)
+			goto err;
+
+		/* ISINK */
+		ret = wm831x_set_bits(wm831x, data->isink_reg,
+				      WM831X_CS1_DRIVE | WM831X_CS1_ENA, 0);
+		if (ret < 0)
+			goto err;
+	}
+
+	/* Set the new brightness */
+	ret = wm831x_set_bits(wm831x, data->isink_reg,
+			      WM831X_CS1_ISEL_MASK, brightness);
+	if (ret < 0)
+		goto err;
+
+	if (power_up) {
+		/* Drive current through the ISINK */
+		ret = wm831x_set_bits(wm831x, data->isink_reg,
+				      WM831X_CS1_DRIVE, WM831X_CS1_DRIVE);
+		if (ret < 0)
+			return ret;
+	}
+
+	data->current_brightness = brightness;
+
+	return 0;
+
+err:
+	/* If we were in the middle of a power transition always shut down
+	 * for safety.
+	 */
+	if (power_up || power_down) {
+		wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
+		wm831x_set_bits(wm831x, data->isink_reg, WM831X_CS1_ENA, 0);
+	}
+
+	return ret;
+}
+
+static int wm831x_backlight_update_status(struct backlight_device *bl)
+{
+	int brightness = bl->props.brightness;
+
+	if (bl->props.power != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	if (bl->props.state & BL_CORE_SUSPENDED)
+		brightness = 0;
+
+	return wm831x_backlight_set(bl, brightness);
+}
+
+static int wm831x_backlight_get_brightness(struct backlight_device *bl)
+{
+	struct wm831x_backlight_data *data = bl_get_data(bl);
+
+	return data->current_brightness;
+}
+
+static const struct backlight_ops wm831x_backlight_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.update_status	= wm831x_backlight_update_status,
+	.get_brightness	= wm831x_backlight_get_brightness,
+};
+
+static int wm831x_backlight_probe(struct platform_device *pdev)
+{
+	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+	struct wm831x_pdata *wm831x_pdata = dev_get_platdata(pdev->dev.parent);
+	struct wm831x_backlight_pdata *pdata;
+	struct wm831x_backlight_data *data;
+	struct backlight_device *bl;
+	struct backlight_properties props;
+	int ret, i, max_isel, isink_reg, dcdc_cfg;
+
+	/* We need platform data */
+	if (wm831x_pdata)
+		pdata = wm831x_pdata->backlight;
+	else
+		pdata = NULL;
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "No platform data supplied\n");
+		return -EINVAL;
+	}
+
+	/* Figure out the maximum current we can use */
+	for (i = 0; i < WM831X_ISINK_MAX_ISEL; i++) {
+		if (wm831x_isinkv_values[i] > pdata->max_uA)
+			break;
+	}
+
+	if (i == 0) {
+		dev_err(&pdev->dev, "Invalid max_uA: %duA\n", pdata->max_uA);
+		return -EINVAL;
+	}
+	max_isel = i - 1;
+
+	if (pdata->max_uA != wm831x_isinkv_values[max_isel])
+		dev_warn(&pdev->dev,
+			 "Maximum current is %duA not %duA as requested\n",
+			 wm831x_isinkv_values[max_isel], pdata->max_uA);
+
+	switch (pdata->isink) {
+	case 1:
+		isink_reg = WM831X_CURRENT_SINK_1;
+		dcdc_cfg = 0;
+		break;
+	case 2:
+		isink_reg = WM831X_CURRENT_SINK_2;
+		dcdc_cfg = WM831X_DC4_FBSRC;
+		break;
+	default:
+		dev_err(&pdev->dev, "Invalid ISINK %d\n", pdata->isink);
+		return -EINVAL;
+	}
+
+	/* Configure the ISINK to use for feedback */
+	ret = wm831x_reg_unlock(wm831x);
+	if (ret < 0)
+		return ret;
+
+	ret = wm831x_set_bits(wm831x, WM831X_DC4_CONTROL, WM831X_DC4_FBSRC,
+			      dcdc_cfg);
+
+	wm831x_reg_lock(wm831x);
+	if (ret < 0)
+		return ret;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	data->wm831x = wm831x;
+	data->current_brightness = 0;
+	data->isink_reg = isink_reg;
+
+	memset(&props, 0, sizeof(props));
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = max_isel;
+	bl = devm_backlight_device_register(&pdev->dev, "wm831x", &pdev->dev,
+					data, &wm831x_backlight_ops, &props);
+	if (IS_ERR(bl)) {
+		dev_err(&pdev->dev, "failed to register backlight\n");
+		return PTR_ERR(bl);
+	}
+
+	bl->props.brightness = max_isel;
+
+	platform_set_drvdata(pdev, bl);
+
+	/* Disable the DCDC if it was started so we can bootstrap */
+	wm831x_set_bits(wm831x, WM831X_DCDC_ENABLE, WM831X_DC4_ENA, 0);
+
+	backlight_update_status(bl);
+
+	return 0;
+}
+
+static struct platform_driver wm831x_backlight_driver = {
+	.driver		= {
+		.name	= "wm831x-backlight",
+	},
+	.probe		= wm831x_backlight_probe,
+};
+
+module_platform_driver(wm831x_backlight_driver);
+
+MODULE_DESCRIPTION("Backlight Driver for WM831x PMICs");
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm831x-backlight");