media: rcar-vin: Route events to correct video device

The event route for VIN running with a media controller (Gen3) is
incorrect as all events are only routed to the video device that are
used to register the async notifier.

Remedy this be examining which subdevice generated the event and route
it to all VIN(s) that are connected to that subdevice.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/rcar-vin/rcar-v4l2.c

@@ -966,12 +966,9 @@ void rvin_v4l2_unregister(struct rvin_dev *vin)
 	video_unregister_device(&vin->vdev);
 }
 
-static void rvin_notify(struct v4l2_subdev *sd,
-			unsigned int notification, void *arg)
+static void rvin_notify_video_device(struct rvin_dev *vin,
+				     unsigned int notification, void *arg)
 {
-	struct rvin_dev *vin =
-		container_of(sd->v4l2_dev, struct rvin_dev, v4l2_dev);
-
 	switch (notification) {
 	case V4L2_DEVICE_NOTIFY_EVENT:
 		v4l2_event_queue(&vin->vdev, arg);
@@ -981,6 +978,41 @@ static void rvin_notify(struct v4l2_subdev *sd,
 	}
 }
 
+static void rvin_notify(struct v4l2_subdev *sd,
+			unsigned int notification, void *arg)
+{
+	struct v4l2_subdev *remote;
+	struct rvin_group *group;
+	struct media_pad *pad;
+	struct rvin_dev *vin =
+		container_of(sd->v4l2_dev, struct rvin_dev, v4l2_dev);
+	unsigned int i;
+
+	/* If no media controller, no need to route the event. */
+	if (!vin->info->use_mc) {
+		rvin_notify_video_device(vin, notification, arg);
+		return;
+	}
+
+	group = vin->group;
+
+	for (i = 0; i < RCAR_VIN_NUM; i++) {
+		vin = group->vin[i];
+		if (!vin)
+			continue;
+
+		pad = media_entity_remote_pad(&vin->pad);
+		if (!pad)
+			continue;
+
+		remote = media_entity_to_v4l2_subdev(pad->entity);
+		if (remote != sd)
+			continue;
+
+		rvin_notify_video_device(vin, notification, arg);
+	}
+}
+
 int rvin_v4l2_register(struct rvin_dev *vin)
 {
 	struct video_device *vdev = &vin->vdev;