backlight: add a callback 'notify_after' for backlight control

We need a callback to do some things after pwm_enable, pwm_disable
and pwm_config.

Signed-off-by: Dilan Lee <dilee@nvidia.com>
Reviewed-by: Robert Morell <rmorell@nvidia.com>
Reviewed-by: Arun Murthy <arun.murthy@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/backlight/pwm_bl.c

@@ -28,6 +28,8 @@ struct pwm_bl_data {
 	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 *);
 };
 
@@ -55,6 +57,10 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
 		pwm_config(pb->pwm, brightness, pb->period);
 		pwm_enable(pb->pwm);
 	}
+
+	if (pb->notify_after)
+		pb->notify_after(pb->dev, brightness);
+
 	return 0;
 }
 
@@ -105,6 +111,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 
 	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);
@@ -172,6 +179,8 @@ static int pwm_backlight_suspend(struct platform_device *pdev,
 		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;
 }
 

include/linux/pwm_backlight.h

@@ -14,6 +14,7 @@ struct platform_pwm_backlight_data {
 	unsigned int pwm_period_ns;
 	int (*init)(struct device *dev);
 	int (*notify)(struct device *dev, int brightness);
+	void (*notify_after)(struct device *dev, int brightness);
 	void (*exit)(struct device *dev);
 	int (*check_fb)(struct device *dev, struct fb_info *info);
 };