media: video-mux: Create media links in bound notifier

Implement a notifier bound op to register media links from the remote
sub-device's source pad(s) to the video-mux sink pad(s).
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/video-mux.c

@@ -17,6 +17,7 @@
 #include <media/v4l2-async.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-fwnode.h>
+#include <media/v4l2-mc.h>
 #include <media/v4l2-subdev.h>
 
 struct video_mux {
@@ -36,6 +37,12 @@ static const struct v4l2_mbus_framefmt video_mux_format_mbus_default = {
 	.field = V4L2_FIELD_NONE,
 };
 
+static inline struct video_mux *
+notifier_to_video_mux(struct v4l2_async_notifier *n)
+{
+	return container_of(n, struct video_mux, notifier);
+}
+
 static inline struct video_mux *v4l2_subdev_to_video_mux(struct v4l2_subdev *sd)
 {
 	return container_of(sd, struct video_mux, subdev);
@@ -332,6 +339,19 @@ static const struct v4l2_subdev_ops video_mux_subdev_ops = {
 	.video = &video_mux_subdev_video_ops,
 };
 
+static int video_mux_notify_bound(struct v4l2_async_notifier *notifier,
+				  struct v4l2_subdev *sd,
+				  struct v4l2_async_subdev *asd)
+{
+	struct video_mux *vmux = notifier_to_video_mux(notifier);
+
+	return v4l2_create_fwnode_links(sd, &vmux->subdev);
+}
+
+static const struct v4l2_async_notifier_operations video_mux_notify_ops = {
+	.bound = video_mux_notify_bound,
+};
+
 static int video_mux_async_register(struct video_mux *vmux,
 				    unsigned int num_input_pads)
 {
@@ -369,6 +389,8 @@ static int video_mux_async_register(struct video_mux *vmux,
 		}
 	}
 
+	vmux->notifier.ops = &video_mux_notify_ops;
+
 	ret = v4l2_async_subdev_notifier_register(&vmux->subdev,
 						  &vmux->notifier);
 	if (ret)