media: imx7: csi: Remove imx7_csi_get_upstream_endpoint()

The function imx7_csi_get_upstream_endpoint() is not necessary for
imx7. First, the imx7 CSI only receives from the CSI mux, so much of
the code in there is pointless. Second, it is only used to determine
whether the CSI mux has selected the CSI-2 input or the parallel input.
This can be accomplished much more simply by getting the function type
of selected input entity to the CSI mux.
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

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

@@ -169,8 +169,6 @@ struct imx7_csi {
 
 	struct media_entity *sink;
 
-	struct v4l2_fwnode_endpoint upstream_ep;
-
 	struct v4l2_mbus_framefmt format_mbus[IMX7_CSI_PADS_NUM];
 	const struct imx_media_pixfmt *cc[IMX7_CSI_PADS_NUM];
 	struct v4l2_fract frame_interval[IMX7_CSI_PADS_NUM];
@@ -435,61 +433,6 @@ static void imx7_csi_deinit(struct imx7_csi *csi)
 	csi->is_init = false;
 }
 
-static int imx7_csi_get_upstream_endpoint(struct imx7_csi *csi,
-					  struct v4l2_fwnode_endpoint *ep,
-					  bool skip_mux)
-{
-	struct device_node *endpoint, *port;
-	struct media_entity *src;
-	struct v4l2_subdev *sd;
-	struct media_pad *pad;
-
-	if (!csi->src_sd)
-		return -EPIPE;
-
-	src = &csi->src_sd->entity;
-
-	/*
-	 * if the source is neither a mux or csi2 get the one directly upstream
-	 * from this csi
-	 */
-	if (src->function != MEDIA_ENT_F_VID_IF_BRIDGE &&
-	    src->function != MEDIA_ENT_F_VID_MUX)
-		src = &csi->sd.entity;
-
-skip_video_mux:
-	/* get source pad of entity directly upstream from src */
-	pad = imx_media_pipeline_pad(src, 0, 0, true);
-	if (!pad)
-		return -ENODEV;
-
-	sd = media_entity_to_v4l2_subdev(pad->entity);
-
-	/* To get bus type we may need to skip video mux */
-	if (skip_mux && src->function == MEDIA_ENT_F_VID_MUX) {
-		src = &sd->entity;
-		goto skip_video_mux;
-	}
-
-	/*
-	 * NOTE: this assumes an OF-graph port id is the same as a
-	 * media pad index.
-	 */
-	port = of_graph_get_port_by_id(sd->dev->of_node, pad->index);
-	if (!port)
-		return -ENODEV;
-
-	endpoint = of_get_next_child(port, NULL);
-	of_node_put(port);
-	if (!endpoint)
-		return -ENODEV;
-
-	v4l2_fwnode_endpoint_parse(of_fwnode_handle(endpoint), ep);
-	of_node_put(endpoint);
-
-	return 0;
-}
-
 static int imx7_csi_link_setup(struct media_entity *entity,
 			       const struct media_pad *local,
 			       const struct media_pad *remote, u32 flags)
@@ -556,23 +499,27 @@ static int imx7_csi_pad_link_validate(struct v4l2_subdev *sd,
 				      struct v4l2_subdev_format *sink_fmt)
 {
 	struct imx7_csi *csi = v4l2_get_subdevdata(sd);
-	struct v4l2_fwnode_endpoint upstream_ep = {};
+	struct media_pad *pad;
 	int ret;
 
 	ret = v4l2_subdev_link_validate_default(sd, link, source_fmt, sink_fmt);
 	if (ret)
 		return ret;
 
-	ret = imx7_csi_get_upstream_endpoint(csi, &upstream_ep, true);
-	if (ret) {
-		v4l2_err(&csi->sd, "failed to find upstream endpoint\n");
-		return ret;
-	}
+	if (!csi->src_sd)
+		return -EPIPE;
+
+	/*
+	 * find the entity that is selected by the CSI mux. This is needed
+	 * to distinguish between a parallel or CSI-2 pipeline.
+	 */
+	pad = imx_media_pipeline_pad(&csi->src_sd->entity, 0, 0, true);
+	if (!pad)
+		return -ENODEV;
 
 	mutex_lock(&csi->lock);
 
-	csi->upstream_ep = upstream_ep;
-	csi->is_csi2 = (upstream_ep.bus_type == V4L2_MBUS_CSI2_DPHY);
+	csi->is_csi2 = (pad->entity->function == MEDIA_ENT_F_VID_IF_BRIDGE);
 
 	mutex_unlock(&csi->lock);