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);
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);
}
#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