media: imx: capture: Support creating immutable link to capture device

When the subdevice connected to the capture device has a single possible
sink, there's no point in making the link mutable. Support creating
immutable links.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/imx/imx-ic-prpencvf.c

@@ -1269,7 +1269,7 @@ static int prp_registered(struct v4l2_subdev *sd)
 	if (IS_ERR(priv->vdev))
 		return PTR_ERR(priv->vdev);
 
-	ret = imx_media_capture_device_register(priv->vdev);
+	ret = imx_media_capture_device_register(priv->vdev, 0);
 	if (ret)
 		goto remove_vdev;
 

drivers/staging/media/imx/imx-media-capture.c

@@ -898,7 +898,8 @@ static int capture_init_format(struct capture_priv *priv)
 	return 0;
 }
 
-int imx_media_capture_device_register(struct imx_media_video_dev *vdev)
+int imx_media_capture_device_register(struct imx_media_video_dev *vdev,
+				      u32 link_flags)
 {
 	struct capture_priv *priv = to_capture_priv(vdev);
 	struct v4l2_subdev *sd = priv->src_sd;
@@ -927,8 +928,10 @@ int imx_media_capture_device_register(struct imx_media_video_dev *vdev)
 		 video_device_node_name(vfd));
 
 	/* Create the link from the src_sd devnode pad to device node. */
+	if (link_flags & MEDIA_LNK_FL_IMMUTABLE)
+		link_flags |= MEDIA_LNK_FL_ENABLED;
 	ret = media_create_pad_link(&sd->entity, priv->src_sd_pad,
-				    &vfd->entity, 0, 0);
+				    &vfd->entity, 0, link_flags);
 	if (ret) {
 		dev_err(priv->dev, "failed to create link to device node\n");
 		video_unregister_device(vfd);

drivers/staging/media/imx/imx-media-csi.c

@@ -1788,7 +1788,7 @@ static int csi_registered(struct v4l2_subdev *sd)
 		goto free_fim;
 	}
 
-	ret = imx_media_capture_device_register(priv->vdev);
+	ret = imx_media_capture_device_register(priv->vdev, 0);
 	if (ret)
 		goto remove_vdev;
 

drivers/staging/media/imx/imx-media.h

@@ -288,7 +288,8 @@ struct imx_media_video_dev *
 imx_media_capture_device_init(struct device *dev, struct v4l2_subdev *src_sd,
 			      int pad, bool legacy_api);
 void imx_media_capture_device_remove(struct imx_media_video_dev *vdev);
-int imx_media_capture_device_register(struct imx_media_video_dev *vdev);
+int imx_media_capture_device_register(struct imx_media_video_dev *vdev,
+				      u32 link_flags);
 void imx_media_capture_device_unregister(struct imx_media_video_dev *vdev);
 struct imx_media_buffer *
 imx_media_capture_device_next_buf(struct imx_media_video_dev *vdev);

drivers/staging/media/imx/imx7-media-csi.c

@@ -1104,7 +1104,7 @@ static int imx7_csi_registered(struct v4l2_subdev *sd)
 	if (IS_ERR(csi->vdev))
 		return PTR_ERR(csi->vdev);
 
-	ret = imx_media_capture_device_register(csi->vdev);
+	ret = imx_media_capture_device_register(csi->vdev, 0);
 	if (ret)
 		imx_media_capture_device_remove(csi->vdev);