2 files changed, 14 insertions, 0 deletions

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 2c2a2c703c14..b8f38ec6eb18 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -28,6 +28,7 @@ struct pwm_bl_data {
         unsigned int            lth_brightness;
         int                     (*notify)(struct device *,
                                           int brightness);
+        int                     (*check_fb)(struct device *, struct fb_info *);
 };
 
 static int pwm_backlight_update_status(struct backlight_device *bl)
@@ -62,9 +63,18 @@ 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)
@@ -95,6 +105,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 
         pb->period = data->pwm_period_ns;
         pb->notify = data->notify;
+        pb->check_fb = data->check_fb;
         pb->lth_brightness = data->lth_brightness *
                 (data->pwm_period_ns / data->max_brightness);
         pb->dev = &pdev->dev;
diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h
index e031e1a486d9..5e3e25a3c9c3 100644
--- a/include/linux/pwm_backlight.h
+++ b/include/linux/pwm_backlight.h
@@ -4,6 +4,8 @@
 #ifndef __LINUX_PWM_BACKLIGHT_H
 #define __LINUX_PWM_BACKLIGHT_H
 
+#include <linux/backlight.h>
+
 struct platform_pwm_backlight_data {
         int pwm_id;
         unsigned int max_brightness;
@@ -13,6 +15,7 @@ struct platform_pwm_backlight_data {
         int (*init)(struct device *dev);
         int (*notify)(struct device *dev, int brightness);
         void (*exit)(struct device *dev);
+        int (*check_fb)(struct device *dev, struct fb_info *info);
 };
 
 #endif