summaryrefslogtreecommitdiff
path: root/drivers/video/backlight/backlight.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/video/backlight/backlight.c')
-rw-r--r--drivers/video/backlight/backlight.c29
1 files changed, 29 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);