init android origin source code

1 files changed, 213 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/drivers/video/backlight/pwm_bl.c b/ANDROID_3.4.5/drivers/video/backlight/pwm_bl.c
new file mode 100644
index 00000000..342b7d7c
--- /dev/null
+++ b/ANDROID_3.4.5/drivers/video/backlight/pwm_bl.c
@@ -0,0 +1,213 @@
+/*
+ * linux/drivers/video/backlight/pwm_bl.c
+ *
+ * simple PWM based backlight control, board code has to setup
+ * 1) pin configuration so PWM waveforms can output
+ * 2) platform_data being correctly configured
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/pwm.h>
+#include <linux/pwm_backlight.h>
+#include <linux/slab.h>
+
+struct pwm_bl_data {
+	struct pwm_device	*pwm;
+	struct device		*dev;
+	unsigned int		period;
+	unsigned int		lth_brightness;
+	int			(*notify)(struct device *,
+					  int brightness);
+	void			(*notify_after)(struct device *,
+					int brightness);
+	int			(*check_fb)(struct device *, struct fb_info *);
+};
+
+static int pwm_backlight_update_status(struct backlight_device *bl)
+{
+	struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
+	int brightness = bl->props.brightness;
+	int max = bl->props.max_brightness;
+
+	if (bl->props.power != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
+		brightness = 0;
+
+	if (pb->notify)
+		brightness = pb->notify(pb->dev, brightness);
+
+	if (brightness == 0) {
+		pwm_config(pb->pwm, 0, pb->period);
+		pwm_disable(pb->pwm);
+	} else {
+		brightness = pb->lth_brightness +
+			(brightness * (pb->period - pb->lth_brightness) / max);
+		pwm_config(pb->pwm, brightness, pb->period);
+		pwm_enable(pb->pwm);
+	}
+
+	if (pb->notify_after)
+		pb->notify_after(pb->dev, brightness);
+
+	return 0;
+}
+
+static int pwm_backlight_get_brightness(struct backlight_device *bl)
+{
+	return bl->props.brightness;
+}
+
+static int pwm_backlight_check_fb(struct backlight_device *bl,
+				  struct fb_info *info)
+{
+	struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
+
+	return !pb->check_fb || pb->check_fb(pb->dev, info);
+}
+
+static const struct backlight_ops pwm_backlight_ops = {
+	.update_status	= pwm_backlight_update_status,
+	.get_brightness	= pwm_backlight_get_brightness,
+	.check_fb	= pwm_backlight_check_fb,
+};
+
+static int pwm_backlight_probe(struct platform_device *pdev)
+{
+	struct backlight_properties props;
+	struct platform_pwm_backlight_data *data = pdev->dev.platform_data;
+	struct backlight_device *bl;
+	struct pwm_bl_data *pb;
+	int ret;
+
+	if (!data) {
+		dev_err(&pdev->dev, "failed to find platform data\n");
+		return -EINVAL;
+	}
+
+	if (data->init) {
+		ret = data->init(&pdev->dev);
+		if (ret < 0)
+			return ret;
+	}
+
+	pb = devm_kzalloc(&pdev->dev, sizeof(*pb), GFP_KERNEL);
+	if (!pb) {
+		dev_err(&pdev->dev, "no memory for state\n");
+		ret = -ENOMEM;
+		goto err_alloc;
+	}
+
+	pb->period = data->pwm_period_ns;
+	pb->notify = data->notify;
+	pb->notify_after = data->notify_after;
+	pb->check_fb = data->check_fb;
+	pb->lth_brightness = data->lth_brightness *
+		(data->pwm_period_ns / data->max_brightness);
+	pb->dev = &pdev->dev;
+
+	pb->pwm = pwm_request(data->pwm_id, "backlight");
+	if (IS_ERR(pb->pwm)) {
+		dev_err(&pdev->dev, "unable to request PWM for backlight\n");
+		ret = PTR_ERR(pb->pwm);
+		goto err_alloc;
+	} else
+		dev_dbg(&pdev->dev, "got pwm for backlight\n");
+
+	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = data->max_brightness;
+	bl = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, pb,
+				       &pwm_backlight_ops, &props);
+	if (IS_ERR(bl)) {
+		dev_err(&pdev->dev, "failed to register backlight\n");
+		ret = PTR_ERR(bl);
+		goto err_bl;
+	}
+
+	bl->props.brightness = data->dft_brightness;
+	backlight_update_status(bl);
+
+	platform_set_drvdata(pdev, bl);
+	return 0;
+
+err_bl:
+	pwm_free(pb->pwm);
+err_alloc:
+	if (data->exit)
+		data->exit(&pdev->dev);
+	return ret;
+}
+
+static int pwm_backlight_remove(struct platform_device *pdev)
+{
+	struct platform_pwm_backlight_data *data = pdev->dev.platform_data;
+	struct backlight_device *bl = platform_get_drvdata(pdev);
+	struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
+
+	backlight_device_unregister(bl);
+	pwm_config(pb->pwm, 0, pb->period);
+	pwm_disable(pb->pwm);
+	pwm_free(pb->pwm);
+	if (data->exit)
+		data->exit(&pdev->dev);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int pwm_backlight_suspend(struct device *dev)
+{
+	struct backlight_device *bl = dev_get_drvdata(dev);
+	struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
+
+	if (pb->notify)
+		pb->notify(pb->dev, 0);
+	pwm_config(pb->pwm, 0, pb->period);
+	pwm_disable(pb->pwm);
+	if (pb->notify_after)
+		pb->notify_after(pb->dev, 0);
+	return 0;
+}
+
+static int pwm_backlight_resume(struct device *dev)
+{
+	struct backlight_device *bl = dev_get_drvdata(dev);
+
+	backlight_update_status(bl);
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(pwm_backlight_pm_ops, pwm_backlight_suspend,
+			 pwm_backlight_resume);
+
+#endif
+
+static struct platform_driver pwm_backlight_driver = {
+	.driver		= {
+		.name	= "pwm-backlight",
+		.owner	= THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm	= &pwm_backlight_pm_ops,
+#endif
+	},
+	.probe		= pwm_backlight_probe,
+	.remove		= pwm_backlight_remove,
+};
+
+module_platform_driver(pwm_backlight_driver);
+
+MODULE_DESCRIPTION("PWM based Backlight Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pwm-backlight");
+