[PATCH v16 05/10] video: backlight: Add devres versions of of_find_backlight

[Meghana Madhyastha]

Add devm_of_find_backlight and the corresponding release
function because some drivers use devres versions of functions
for acquiring device resources.

Signed-off-by: Meghana Madhyastha <meghana.madhyastha@xxxxxxxxx>
---
 drivers/video/backlight/backlight.c | 29 +++++++++++++++++++++++++++++
 include/linux/backlight.h           |  7 +++++++
 2 files changed, 36 insertions(+)

diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 7e4a5d77d..b3f76945f 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -620,6 +620,35 @@ struct backlight_device *of_find_backlight(struct device *dev)
 }
 EXPORT_SYMBOL(of_find_backlight);
 
+static void devm_backlight_put(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_put, 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 32ea510da..1d373f5a6 100644
--- a/include/linux/backlight.h
+++ b/include/linux/backlight.h
@@ -215,11 +215,18 @@ of_find_backlight_by_node(struct device_node *node)
 
 #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
-- 
2.11.0