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>
diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h
index 5e3e25a..63d2df4 100644
--- a/include/linux/pwm_backlight.h
+++ b/include/linux/pwm_backlight.h
@@ -14,6 +14,7 @@
 	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);
 };