backlight: Add suspend/resume support to the backlight core

Add suspend/resume support to the backlight core and enable use of it
by appropriate drivers.

Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index a9c013bb9f2..157057c79ca 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -40,6 +40,10 @@ static int fb_notifier_callback(struct notifier_block *self,
                 if (!bd->ops->check_fb ||
                     bd->ops->check_fb(evdata->info)) {
                         bd->props.fb_blank = *(int *)evdata->data;
+                        if (bd->props.fb_blank == FB_BLANK_UNBLANK)
+                                bd->props.state &= ~BL_CORE_FBBLANK;
+                        else
+                                bd->props.state |= BL_CORE_FBBLANK;
                         backlight_update_status(bd);
                 }
         mutex_unlock(&bd->ops_lock);
@@ -165,6 +169,34 @@ static ssize_t backlight_show_actual_brightness(struct device *dev,
 
 static struct class *backlight_class;
 
+static int backlight_suspend(struct device *dev, pm_message_t state)
+{
+        struct backlight_device *bd = to_backlight_device(dev);
+
+        if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
+                mutex_lock(&bd->ops_lock);
+                bd->props.state |= BL_CORE_SUSPENDED;
+                backlight_update_status(bd);
+                mutex_unlock(&bd->ops_lock);
+        }
+
+        return 0;
+}
+
+static int backlight_resume(struct device *dev)
+{
+        struct backlight_device *bd = to_backlight_device(dev);
+
+        if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
+                mutex_lock(&bd->ops_lock);
+                bd->props.state &= ~BL_CORE_SUSPENDED;
+                backlight_update_status(bd);
+                mutex_unlock(&bd->ops_lock);
+        }
+
+        return 0;
+}
+
 static void bl_device_release(struct device *dev)
 {
         struct backlight_device *bd = to_backlight_device(dev);
@@ -281,6 +313,8 @@ static int __init backlight_class_init(void)
         }
 
         backlight_class->dev_attrs = bl_device_attributes;
+        backlight_class->suspend = backlight_suspend;
+        backlight_class->resume = backlight_resume;
         return 0;
 }