diff options
| -rw-r--r-- | drivers/video/backlight/backlight.c | 29 | ||||
| -rw-r--r-- | include/linux/backlight.h | 10 |
2 files changed, 39 insertions, 0 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 297db2fa91f5..345f6660d4b3 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -370,6 +370,35 @@ void backlight_device_unregister(struct backlight_device *bd) } EXPORT_SYMBOL(backlight_device_unregister); +#ifdef CONFIG_OF +static int of_parent_match(struct device *dev, void *data) +{ + return dev->parent && dev->parent->of_node == data; +} + +/** + * of_find_backlight_by_node() - find backlight device by device-tree node + * @node: device-tree node of the backlight device + * + * Returns a pointer to the backlight device corresponding to the given DT + * node or NULL if no such backlight device exists or if the device hasn't + * been probed yet. + * + * This function obtains a reference on the backlight device and it is the + * caller's responsibility to drop the reference by calling put_device() on + * the backlight device's .dev field. + */ +struct backlight_device *of_find_backlight_by_node(struct device_node *node) +{ + struct device *dev; + + dev = class_find_device(backlight_class, NULL, node, of_parent_match); + + return dev ? to_backlight_device(dev) : NULL; +} +EXPORT_SYMBOL(of_find_backlight_by_node); +#endif + static void __exit backlight_class_exit(void) { class_destroy(backlight_class); diff --git a/include/linux/backlight.h b/include/linux/backlight.h index 5ffc6dda4675..da9a0825e007 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -134,4 +134,14 @@ struct generic_bl_info { void (*kick_battery)(void); }; +#ifdef CONFIG_OF +struct backlight_device *of_find_backlight_by_node(struct device_node *node); +#else +static inline struct backlight_device * +of_find_backlight_by_node(struct device_node *node) +{ + return NULL; +} +#endif + #endif |