media: v4l2-mc: Add link flags to v4l2_create_fwnode_links_to_pad()

Add a flags argument to the v4l2_create_fwnode_links_to_pad() function
to specify the link flags. This allows drivers to create immutable links
for instance.
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/media/v4l2-core/v4l2-mc.c

@@ -310,7 +310,7 @@ int v4l_vb2q_enable_media_source(struct vb2_queue *q)
 EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
 
 int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
-				    struct media_pad *sink)
+				    struct media_pad *sink, u32 flags)
 {
 	struct fwnode_handle *endpoint;
 	struct v4l2_subdev *sink_sd;
@@ -367,7 +367,7 @@ int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
 			sink_sd->entity.name, sink_idx);
 
 		ret = media_create_pad_link(&src_sd->entity, src_idx,
-					    &sink_sd->entity, sink_idx, 0);
+					    &sink_sd->entity, sink_idx, flags);
 		if (ret) {
 			dev_err(sink_sd->dev,
 				"link %s:%d -> %s:%d failed with %d\n",
@@ -395,7 +395,7 @@ int v4l2_create_fwnode_links(struct v4l2_subdev *src_sd,
 		if (!(pad->flags & MEDIA_PAD_FL_SINK))
 			continue;
 
-		ret = v4l2_create_fwnode_links_to_pad(src_sd, pad);
+		ret = v4l2_create_fwnode_links_to_pad(src_sd, pad, 0);
 		if (ret)
 			return ret;
 	}

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

@@ -1894,7 +1894,7 @@ static int imx_csi_notify_bound(struct v4l2_async_notifier *notifier,
 	if (sd->entity.function == MEDIA_ENT_F_VID_MUX)
 		sd->grp_id = IMX_MEDIA_GRP_ID_CSI_MUX;
 
-	return v4l2_create_fwnode_links_to_pad(sd, sink);
+	return v4l2_create_fwnode_links_to_pad(sd, sink, 0);
 }
 
 static const struct v4l2_async_notifier_operations csi_notify_ops = {

drivers/staging/media/imx/imx6-mipi-csi2.c

@@ -621,7 +621,7 @@ static int csi2_notify_bound(struct v4l2_async_notifier *notifier,
 
 	dev_dbg(csi2->dev, "Bound %s pad: %d\n", sd->name, pad);
 
-	return v4l2_create_fwnode_links_to_pad(sd, sink);
+	return v4l2_create_fwnode_links_to_pad(sd, sink, 0);
 }
 
 static void csi2_notify_unbind(struct v4l2_async_notifier *notifier,

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

@@ -1128,7 +1128,7 @@ static int imx7_csi_notify_bound(struct v4l2_async_notifier *notifier,
 	if (sd->entity.function == MEDIA_ENT_F_VID_MUX)
 		sd->grp_id = IMX_MEDIA_GRP_ID_CSI_MUX;
 
-	return v4l2_create_fwnode_links_to_pad(sd, sink);
+	return v4l2_create_fwnode_links_to_pad(sd, sink, 0);
 }
 
 static const struct v4l2_async_notifier_operations imx7_csi_notify_ops = {

drivers/staging/media/imx/imx7-mipi-csis.c

@@ -962,7 +962,7 @@ static int mipi_csis_notify_bound(struct v4l2_async_notifier *notifier,
 	struct csi_state *state = mipi_notifier_to_csis_state(notifier);
 	struct media_pad *sink = &state->mipi_sd.entity.pads[CSIS_PAD_SINK];
 
-	return v4l2_create_fwnode_links_to_pad(sd, sink);
+	return v4l2_create_fwnode_links_to_pad(sd, sink, 0);
 }
 
 static const struct v4l2_async_notifier_operations mipi_csis_notify_ops = {

include/media/v4l2-mc.h

@@ -91,6 +91,7 @@ int v4l_vb2q_enable_media_source(struct vb2_queue *q);
  *
  * @src_sd: pointer to a source subdev
  * @sink:  pointer to a subdev sink pad
+ * @flags: the link flags
  *
  * This function searches for fwnode endpoint connections from a source
  * subdevice to a single sink pad, and if suitable connections are found,
@@ -98,6 +99,11 @@ int v4l_vb2q_enable_media_source(struct vb2_queue *q);
  * called by the sink subdevice, in its v4l2-async notifier subdev bound
  * callback, to create links from a bound source subdevice.
  *
+ * The @flags argument specifies the link flags. The caller shall ensure that
+ * the flags are valid regardless of the number of links that may be created.
+ * For instance, setting the MEDIA_LNK_FL_ENABLED flag will cause all created
+ * links to be enabled, which isn't valid if more than one link is created.
+ *
  * .. note::
  *
  *    Any sink subdevice that calls this function must implement the
@@ -107,7 +113,7 @@ int v4l_vb2q_enable_media_source(struct vb2_queue *q);
  * Return 0 on success or a negative error code on failure.
  */
 int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
-				    struct media_pad *sink);
+				    struct media_pad *sink, u32 flags);
 
 /**
  * v4l2_create_fwnode_links - Create fwnode-based links from a source