media: staging/imx: remove static media link arrays

Remove the static list of media links that were formed at probe time.
These links can instead be created after all registered async subdevices
have been bound in imx_media_probe_complete().

The media links between subdevices that exist in the device tree, can
be created post-async completion by using v4l2_fwnode_parse_link() for
each endpoint node of that subdevice. Note this approach assumes
device-tree ports are equivalent to media pads (pad index equals
port id), and that device-tree endpoints are equivalent to media
links between pads.

Because links are no longer parsed by imx_media_of_parse(), its sole
function is now only to add subdevices that it encounters by walking
the OF graph to the async list, so the function has been renamed
imx_media_add_of_subdevs().

Similarly, the media links between the IPU-internal subdevice pads (the
CSI source pads, and all pads between the vdic, ic-prp, ic-prpenc, and
ic-prpvf subdevices), can be created post-async completion by looping
through the subdevice's media pads and using the const internal_subdev
table.

Because links are no longer parsed by imx_media_add_internal_subdevs(),
this function no longer needs an array of CSI subdevs to form links
from.

In summary, the following functions, which were used to form a list
of media links at probe time, are removed:

imx_media_add_pad_link()
add_internal_links()
of_add_pad_link()

replaced by these functions, called at probe time, which only populate
the async subdev list:

imx_media_add_of_subdevs()
imx_media_add_internal_subdevs()

and these functions, called at async completion, which create the
media links:

imx_media_create_of_links()
imx_media_create_csi_of_links()
imx_media_create_internal_links()

Signed-off-by: Steve Longerbeam <[email protected]>
Signed-off-by: Hans Verkuil <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>

Author: slongerbeam

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

@@ -11,6 +11,7 @@
 #include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/module.h>
+#include <linux/of_graph.h>
 #include <linux/of_platform.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
@@ -127,50 +128,6 @@ imx_media_add_async_subdev(struct imx_media_dev *imxmd,
 	return imxsd;
 }
 
-/*
- * Adds an imx-media link to a subdev pad's link list. This is called
- * during driver load when forming the links between subdevs.
- *
- * @pad: the local pad
- * @remote_node: the device node of the remote subdev
- * @remote_devname: the device name of the remote subdev
- * @local_pad: local pad index
- * @remote_pad: remote pad index
- */
-int imx_media_add_pad_link(struct imx_media_dev *imxmd,
-			   struct imx_media_pad *pad,
-			   struct device_node *remote_node,
-			   const char *remote_devname,
-			   int local_pad, int remote_pad)
-{
-	struct imx_media_link *link;
-	int link_idx, ret = 0;
-
-	mutex_lock(&imxmd->mutex);
-
-	link_idx = pad->num_links;
-	if (link_idx >= IMX_MEDIA_MAX_LINKS) {
-		dev_err(imxmd->md.dev, "%s: too many links!\n", __func__);
-		ret = -ENOSPC;
-		goto out;
-	}
-
-	link = &pad->link[link_idx];
-
-	link->remote_sd_node = remote_node;
-	if (remote_devname)
-		strncpy(link->remote_devname, remote_devname,
-			sizeof(link->remote_devname));
-
-	link->local_pad = local_pad;
-	link->remote_pad = remote_pad;
-
-	pad->num_links++;
-out:
-	mutex_unlock(&imxmd->mutex);
-	return ret;
-}
-
 /*
  * get IPU from this CSI and add it to the list of IPUs
  * the media driver will control.
@@ -240,76 +197,38 @@ static int imx_media_subdev_bound(struct v4l2_async_notifier *notifier,
 }
 
 /*
- * Create a single source->sink media link given a subdev and a single
- * link from one of its source pads. Called after all subdevs have
- * registered.
- */
-static int imx_media_create_link(struct imx_media_dev *imxmd,
-				 struct imx_media_subdev *src,
-				 struct imx_media_link *link)
-{
-	struct imx_media_subdev *sink;
-	u16 source_pad, sink_pad;
-	int ret;
-
-	sink = imx_media_find_async_subdev(imxmd, link->remote_sd_node,
-					   link->remote_devname);
-	if (!sink) {
-		v4l2_warn(&imxmd->v4l2_dev, "%s: no sink for %s:%d\n",
-			  __func__, src->sd->name, link->local_pad);
-		return 0;
-	}
-
-	source_pad = link->local_pad;
-	sink_pad = link->remote_pad;
-
-	v4l2_info(&imxmd->v4l2_dev, "%s: %s:%d -> %s:%d\n", __func__,
-		  src->sd->name, source_pad, sink->sd->name, sink_pad);
-
-	ret = media_create_pad_link(&src->sd->entity, source_pad,
-				    &sink->sd->entity, sink_pad, 0);
-	if (ret)
-		v4l2_err(&imxmd->v4l2_dev,
-			 "create_pad_link failed: %d\n", ret);
-
-	return ret;
-}
-
-/*
- * create the media links from all imx-media pads and their links.
+ * create the media links from all pads and their links.
  * Called after all subdevs have registered.
  */
 static int imx_media_create_links(struct imx_media_dev *imxmd)
 {
 	struct imx_media_subdev *imxsd;
-	struct imx_media_link *link;
-	struct imx_media_pad *pad;
-	int num_pads, i, j, k;
-	int ret = 0;
+	struct v4l2_subdev *sd;
+	int i, ret;
 
 	for (i = 0; i < imxmd->num_subdevs; i++) {
 		imxsd = &imxmd->subdev[i];
-		num_pads = imxsd->num_sink_pads + imxsd->num_src_pads;
-
-		for (j = 0; j < num_pads; j++) {
-			pad = &imxsd->pad[j];
-
-			/* only create the source->sink links */
-			if (!(pad->pad.flags & MEDIA_PAD_FL_SOURCE))
-				continue;
-
-			for (k = 0; k < pad->num_links; k++) {
-				link = &pad->link[k];
+		sd = imxsd->sd;
 
-				ret = imx_media_create_link(imxmd, imxsd, link);
-				if (ret)
-					goto out;
-			}
+		if (((sd->grp_id & IMX_MEDIA_GRP_ID_CSI) || imxsd->pdev)) {
+			/* this is an internal subdev or a CSI */
+			ret = imx_media_create_internal_links(imxmd, imxsd);
+			if (ret)
+				return ret;
+			/*
+			 * the CSIs straddle between the external and the IPU
+			 * internal entities, so create the external links
+			 * to the CSI sink pads.
+			 */
+			if (sd->grp_id & IMX_MEDIA_GRP_ID_CSI)
+				imx_media_create_csi_of_links(imxmd, imxsd);
+		} else {
+			/* this is an external fwnode subdev */
+			imx_media_create_of_links(imxmd, imxsd);
 		}
 	}
 
-out:
-	return ret;
+	return 0;
 }
 
 /*
@@ -550,7 +469,6 @@ static int imx_media_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *node = dev->of_node;
-	struct imx_media_subdev *csi[4] = {0};
 	struct imx_media_dev *imxmd;
 	int ret;
 
@@ -581,14 +499,14 @@ static int imx_media_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(imxmd->v4l2_dev.dev, imxmd);
 
-	ret = imx_media_of_parse(imxmd, &csi, node);
+	ret = imx_media_add_of_subdevs(imxmd, node);
 	if (ret) {
 		v4l2_err(&imxmd->v4l2_dev,
-			 "imx_media_of_parse failed with %d\n", ret);
+			 "add_of_subdevs failed with %d\n", ret);
 		goto unreg_dev;
 	}
 
-	ret = imx_media_add_internal_subdevs(imxmd, csi);
+	ret = imx_media_add_internal_subdevs(imxmd);
 	if (ret) {
 		v4l2_err(&imxmd->v4l2_dev,
 			 "add_internal_subdevs failed with %d\n", ret);