[media] V4L: Add v4l2_ctrl_subdev_log_status() helper function

This patch adds a v4l2 core helper function that can be used as
the log_status handler for subdevs that only need to log state
of the v4l2 controls owned by the subdev's control handler.
Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/v4l2-core/v4l2-ctrls.c

@@ -2004,6 +2004,13 @@ void v4l2_ctrl_handler_log_status(struct v4l2_ctrl_handler *hdl,
 }
 EXPORT_SYMBOL(v4l2_ctrl_handler_log_status);
 
+int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd)
+{
+	v4l2_ctrl_handler_log_status(sd->ctrl_handler, sd->name);
+	return 0;
+}
+EXPORT_SYMBOL(v4l2_ctrl_subdev_log_status);
+
 /* Call s_ctrl for all controls owned by the handler */
 int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl)
 {

include/media/v4l2-ctrls.h

@@ -659,4 +659,7 @@ int v4l2_subdev_s_ctrl(struct v4l2_subdev *sd, struct v4l2_control *ctrl);
 int v4l2_ctrl_subdev_subscribe_event(struct v4l2_subdev *sd, struct v4l2_fh *fh,
 				     struct v4l2_event_subscription *sub);
 
+/* Log all controls owned by subdev's control handler. */
+int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
+
 #endif