diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 8049e7656daa..deb824bef6e2 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -580,6 +580,79 @@ struct backlight_device *of_find_backlight_by_node(struct device_node *node) EXPORT_SYMBOL(of_find_backlight_by_node); #endif +/** + * of_find_backlight - Get backlight device + * @dev: Device + * + * This function looks for a property named 'backlight' on the DT node + * connected to @dev and looks up the backlight device. + * + * Call backlight_put() to drop the reference on the backlight device. + * + * Returns: + * A pointer to the backlight device if found. + * Error pointer -EPROBE_DEFER if the DT property is set, but no backlight + * device is found. + * NULL if there's no backlight property. + */ +struct backlight_device *of_find_backlight(struct device *dev) +{ + struct backlight_device *bd = NULL; + struct device_node *np; + + if (!dev) + return NULL; + + if (IS_ENABLED(CONFIG_OF) && dev->of_node) { + np = of_parse_phandle(dev->of_node, "backlight", 0); + if (np) { + bd = of_find_backlight_by_node(np); + of_node_put(np); + if (!bd) + return ERR_PTR(-EPROBE_DEFER); + /* + * Note: gpio_backlight uses brightness as + * power state during probe + */ + if (!bd->props.brightness) + bd->props.brightness = bd->props.max_brightness; + } + } + + return bd; +} +EXPORT_SYMBOL(of_find_backlight); + +static void devm_backlight_release(void *data) +{ + backlight_put(data); +} + +/** + * devm_of_find_backlight - Resource-managed of_find_backlight() + * @dev: Device + * + * Device managed version of of_find_backlight(). + * The reference on the backlight device is automatically + * dropped on driver detach. + */ +struct backlight_device *devm_of_find_backlight(struct device *dev) +{ + struct backlight_device *bd; + int ret; + + bd = of_find_backlight(dev); + if (IS_ERR_OR_NULL(bd)) + return bd; + ret = devm_add_action(dev, devm_backlight_release, bd); + if (ret) { + backlight_put(bd); + return ERR_PTR(ret); + } + return bd; +} +EXPORT_SYMBOL(devm_of_find_backlight); + static void __exit backlight_class_exit(void) { class_destroy(backlight_class); diff --git a/include/linux/backlight.h b/include/linux/backlight.h index af7003548593..2baab6f3861d 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -130,6 +130,48 @@ static inline int backlight_update_status(struct backlight_device *bd) return ret; } +/** + * backlight_enable - Enable backlight + * @bd: the backlight device to enable + */ +static inline int backlight_enable(struct backlight_device *bd) +{ + if (!bd) + return 0; + + bd->props.power = FB_BLANK_UNBLANK; + bd->props.fb_blank = FB_BLANK_UNBLANK; + bd->props.state &= ~BL_CORE_FBBLANK; + + return backlight_update_status(bd); +} + +/** + * backlight_disable - Disable backlight + * @bd: the backlight device to disable + */ +static inline int backlight_disable(struct backlight_device *bd) +{ + if (!bd) + return 0; + + bd->props.power = FB_BLANK_POWERDOWN; + bd->props.fb_blank = FB_BLANK_POWERDOWN; + bd->props.state |= BL_CORE_FBBLANK; + + return backlight_update_status(bd); +} + +/** + * backlight_put - Drop backlight reference + * @bd: the backlight device to put + */ +static inline void backlight_put(struct backlight_device *bd) +{ + if (bd) + put_device(&bd->dev); +} + extern struct backlight_device *backlight_device_register(const char *name, struct device *dev, void *devdata, const struct backlight_ops *ops, const struct backlight_properties *props); @@ -173,4 +215,20 @@ of_find_backlight_by_node(struct device_node *node) } #endif +#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE) +struct backlight_device *of_find_backlight(struct device *dev); +struct backlight_device *devm_of_find_backlight(struct device *dev); +#else +static inline struct backlight_device *of_find_backlight(struct device *dev) +{ + return NULL; +} + +static inline struct backlight_device * +devm_of_find_backlight(struct device *dev) +{ + return NULL; +} +#endif + #endif