Merge branch 'akpm' (Andrew's patch-bomb)

Merge misc patches from Andrew Morton:
 "Incoming:

   - lots of misc stuff

   - backlight tree updates

   - lib/ updates

   - Oleg's percpu-rwsem changes

   - checkpatch

   - rtc

   - aoe

   - more checkpoint/restart support

  I still have a pile of MM stuff pending - Pekka should be merging
  later today after which that is good to go.  A number of other things
  are twiddling thumbs awaiting maintainer merges."

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (180 commits)
  scatterlist: don't BUG when we can trivially return a proper error.
  docs: update documentation about /proc/<pid>/fdinfo/<fd> fanotify output
  fs, fanotify: add @mflags field to fanotify output
  docs: add documentation about /proc/<pid>/fdinfo/<fd> output
  fs, notify: add procfs fdinfo helper
  fs, exportfs: add exportfs_encode_inode_fh() helper
  fs, exportfs: escape nil dereference if no s_export_op present
  fs, epoll: add procfs fdinfo helper
  fs, eventfd: add procfs fdinfo helper
  procfs: add ability to plug in auxiliary fdinfo providers
  tools/testing/selftests/kcmp/kcmp_test.c: print reason for failure in kcmp_test
  breakpoint selftests: print failure status instead of cause make error
  kcmp selftests: print fail status instead of cause make error
  kcmp selftests: make run_tests fix
  mem-hotplug selftests: print failure status instead of cause make error
  cpu-hotplug selftests: print failure status instead of cause make error
  mqueue selftests: print failure status instead of cause make error
  vm selftests: print failure status instead of cause make error
  ubifs: use prandom_bytes
  mtd: nandsim: use prandom_bytes
  ...

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);