diff options
| -rw-r--r-- | drivers/video/backlight/backlight.c | 31 | ||||
| -rw-r--r-- | include/linux/backlight.h | 4 |
2 files changed, 35 insertions, 0 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 94a403a9717a..5d05555fe841 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -21,6 +21,9 @@ #include <asm/backlight.h> #endif +static struct list_head backlight_dev_list; +static struct mutex backlight_dev_list_mutex; + static const char *const backlight_types[] = { [BACKLIGHT_RAW] = "raw", [BACKLIGHT_PLATFORM] = "platform", @@ -349,10 +352,32 @@ struct backlight_device *backlight_device_register(const char *name, mutex_unlock(&pmac_backlight_mutex); #endif + mutex_lock(&backlight_dev_list_mutex); + list_add(&new_bd->entry, &backlight_dev_list); + mutex_unlock(&backlight_dev_list_mutex); + return new_bd; } EXPORT_SYMBOL(backlight_device_register); +bool backlight_device_registered(enum backlight_type type) +{ + bool found = false; + struct backlight_device *bd; + + mutex_lock(&backlight_dev_list_mutex); + list_for_each_entry(bd, &backlight_dev_list, entry) { + if (bd->props.type == type) { + found = true; + break; + } + } + mutex_unlock(&backlight_dev_list_mutex); + + return found; +} +EXPORT_SYMBOL(backlight_device_registered); + /** * backlight_device_unregister - unregisters a backlight device object. * @bd: the backlight device object to be unregistered and freed. @@ -364,6 +389,10 @@ void backlight_device_unregister(struct backlight_device *bd) if (!bd) return; + mutex_lock(&backlight_dev_list_mutex); + list_del(&bd->entry); + mutex_unlock(&backlight_dev_list_mutex); + #ifdef CONFIG_PMAC_BACKLIGHT mutex_lock(&pmac_backlight_mutex); if (pmac_backlight == bd) @@ -499,6 +528,8 @@ static int __init backlight_class_init(void) backlight_class->dev_groups = bl_device_groups; backlight_class->pm = &backlight_class_dev_pm_ops; + INIT_LIST_HEAD(&backlight_dev_list); + mutex_init(&backlight_dev_list_mutex); return 0; } diff --git a/include/linux/backlight.h b/include/linux/backlight.h index 53b77949c79d..5f9cd963213d 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -100,6 +100,9 @@ struct backlight_device { /* The framebuffer notifier block */ struct notifier_block fb_notif; + /* list entry of all registered backlight devices */ + struct list_head entry; + struct device dev; }; @@ -123,6 +126,7 @@ extern void devm_backlight_device_unregister(struct device *dev, struct backlight_device *bd); extern void backlight_force_update(struct backlight_device *bd, enum backlight_update_reason reason); +extern bool backlight_device_registered(enum backlight_type type); #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev) |