[PATCH v4 08/17] media: imx: Add imx_media_create_fwnode_pad_link()

[Steve Longerbeam <slongerbeam@gmail.com>]

Add functions to create media links between a source and sink subdevice
based on fwnode endpoint connections between them.

Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
---
 drivers/staging/media/imx/imx-media-utils.c | 91 +++++++++++++++++++++
 drivers/staging/media/imx/imx-media.h       |  4 +
 2 files changed, 95 insertions(+)

diff --git a/drivers/staging/media/imx/imx-media-utils.c b/drivers/staging/media/imx/imx-media-utils.c
index 0788a1874557..87152bd9af22 100644
--- a/drivers/staging/media/imx/imx-media-utils.c
+++ b/drivers/staging/media/imx/imx-media-utils.c
@@ -729,6 +729,97 @@ void imx_media_grp_id_to_sd_name(char *sd_name, int sz, u32 grp_id, int ipu_id)
 }
 EXPORT_SYMBOL_GPL(imx_media_grp_id_to_sd_name);
 
+/*
+ * Look for and create a single fwnode link that connects a source
+ * subdevice to a sink pad.
+ */
+int imx_media_create_fwnode_pad_link(struct v4l2_subdev *src_sd,
+				     struct media_pad *sink)
+{
+	struct fwnode_handle *endpoint;
+
+	/* loop thru the source's fwnode endpoints */
+	fwnode_graph_for_each_endpoint(dev_fwnode(src_sd->dev), endpoint) {
+		struct fwnode_handle *remote_ep;
+		int src_idx, sink_idx, ret;
+		struct media_pad *src;
+
+		remote_ep = fwnode_graph_get_remote_endpoint(endpoint);
+		if (!remote_ep)
+			continue;
+
+		/*
+		 * ask the sink entity to verify that this fwnode link
+		 * actually does connect with the entity, and if so that
+		 * it connects to its requested sink pad.
+		 */
+		sink_idx = media_entity_get_fwnode_pad(sink->entity,
+						       remote_ep,
+						       MEDIA_PAD_FL_SINK);
+		fwnode_handle_put(remote_ep);
+
+		if (sink_idx < 0 || sink_idx != sink->index)
+			continue;
+
+		src_idx = media_entity_get_fwnode_pad(&src_sd->entity,
+						      endpoint,
+						      MEDIA_PAD_FL_SOURCE);
+		if (src_idx < 0)
+			continue;
+
+		/*
+		 * found the fwnode link that works, create the media
+		 * link for it.
+		 */
+
+		fwnode_handle_put(endpoint);
+
+		src = &src_sd->entity.pads[src_idx];
+
+		/* success if it already exists */
+		if (media_entity_find_link(src, sink))
+			return 0;
+
+		dev_dbg(src_sd->dev, "%s:%d -> %s:%d\n",
+			src_sd->entity.name, src_idx,
+			sink->entity->name, sink_idx);
+
+		ret = media_create_pad_link(&src_sd->entity, src_idx,
+					    sink->entity, sink_idx, 0);
+		if (ret)
+			dev_err(src_sd->dev,
+				"%s:%d -> %s:%d failed with %d\n",
+				src_sd->entity.name, src_idx,
+				sink->entity->name, sink_idx, ret);
+
+		return ret;
+	}
+
+	return -ENXIO;
+}
+EXPORT_SYMBOL_GPL(imx_media_create_fwnode_pad_link);
+
+int imx_media_create_fwnode_pad_links(struct v4l2_subdev *src_sd,
+				      struct v4l2_subdev *sink_sd)
+{
+	int i;
+
+	for (i = 0; i < sink_sd->entity.num_pads; i++) {
+		struct media_pad *pad = &sink_sd->entity.pads[i];
+		int ret;
+
+		if (!(pad->flags & MEDIA_PAD_FL_SINK))
+			continue;
+
+		ret = imx_media_create_fwnode_pad_link(src_sd, pad);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(imx_media_create_fwnode_pad_links);
+
 struct v4l2_subdev *
 imx_media_find_subdev_by_fwnode(struct imx_media_dev *imxmd,
 				struct fwnode_handle *fwnode)
diff --git a/drivers/staging/media/imx/imx-media.h b/drivers/staging/media/imx/imx-media.h
index 11861191324a..f90a65ba4ced 100644
--- a/drivers/staging/media/imx/imx-media.h
+++ b/drivers/staging/media/imx/imx-media.h
@@ -183,6 +183,10 @@ int imx_media_ipu_image_to_mbus_fmt(struct v4l2_mbus_framefmt *mbus,
 				    struct ipu_image *image);
 void imx_media_grp_id_to_sd_name(char *sd_name, int sz,
 				 u32 grp_id, int ipu_id);
+int imx_media_create_fwnode_pad_link(struct v4l2_subdev *src_sd,
+				     struct media_pad *sink);
+int imx_media_create_fwnode_pad_links(struct v4l2_subdev *src_sd,
+				      struct v4l2_subdev *sink_sd);
 struct v4l2_subdev *
 imx_media_find_subdev_by_fwnode(struct imx_media_dev *imxmd,
 				struct fwnode_handle *fwnode);
-- 
2.17.1