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

From: Meghana Madhyastha
Date: Tue Jan 16 2018 - 05:34:46 EST


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