[media] v4l: Add source change event

This event indicates that the video device has encountered
a source parameter change during runtime. This can typically be a
resolution change detected by a video decoder OR a format change
detected by an input connector.

This needs to be nofified to the userspace and the application may
be expected to reallocate buffers before proceeding. The application
can subscribe to events on a specific pad or input port which
it is interested in.

Signed-off-by: Arun Kumar K <arun.kk@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h
index be05d01..1ab9045 100644
--- a/include/media/v4l2-event.h
+++ b/include/media/v4l2-event.h
@@ -132,4 +132,8 @@
 void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
 int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd, struct v4l2_fh *fh,
 				  struct v4l2_event_subscription *sub);
+int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
+				const struct v4l2_event_subscription *sub);
+int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
+		struct v4l2_fh *fh, struct v4l2_event_subscription *sub);
 #endif /* V4L2_EVENT_H */