media: platform: Switch to v4l2_async_notifier_add_subdev

Switch all media platform drivers to call v4l2_async_notifier_add_subdev()
to add asd's to a notifier, in place of referencing the notifier->subdevs[]
array. These drivers also must now call v4l2_async_notifier_init() before
adding asd's to their notifiers.

There may still be cases where a platform driver maintains a list of
asd's that is a duplicate of the notifier asd_list, in which case its
possible the platform driver list can be removed, and can reference the
notifier asd_list instead. One example of where a duplicate list has
been removed in this patch is xilinx-vipp.c. If there are such cases
remaining, those drivers should be optimized to remove the duplicate
platform driver asd lists.

None of the changes to the platform drivers in this patch have been
tested. Verify that the async subdevices needed by the platform are
bound at load time, and that the driver unloads and reloads correctly
with no memory leaking of asd objects.

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

2 files changed, 80 insertions, 97 deletions

diff --git a/drivers/media/platform/xilinx/xilinx-vipp.c b/drivers/media/platform/xilinx/xilinx-vipp.c
index 5148df007c6e..99e016d35d91 100644
--- a/drivers/media/platform/xilinx/xilinx-vipp.c
+++ b/drivers/media/platform/xilinx/xilinx-vipp.c
@@ -32,33 +32,36 @@
 
 /**
  * struct xvip_graph_entity - Entity in the video graph
- * @list: list entry in a graph entities list
- * @node: the entity's DT node
- * @entity: media entity, from the corresponding V4L2 subdev
  * @asd: subdev asynchronous registration information
+ * @entity: media entity, from the corresponding V4L2 subdev
  * @subdev: V4L2 subdev
  */
 struct xvip_graph_entity {
-	struct list_head list;
-	struct device_node *node;
+	struct v4l2_async_subdev asd; /* must be first */
 	struct media_entity *entity;
-
-	struct v4l2_async_subdev asd;
 	struct v4l2_subdev *subdev;
 };
 
+static inline struct xvip_graph_entity *
+to_xvip_entity(struct v4l2_async_subdev *asd)
+{
+	return container_of(asd, struct xvip_graph_entity, asd);
+}
+
 /* -----------------------------------------------------------------------------
  * Graph Management
  */
 
 static struct xvip_graph_entity *
 xvip_graph_find_entity(struct xvip_composite_device *xdev,
-		       const struct device_node *node)
+		       const struct fwnode_handle *fwnode)
 {
 	struct xvip_graph_entity *entity;
+	struct v4l2_async_subdev *asd;
 
-	list_for_each_entry(entity, &xdev->entities, list) {
-		if (entity->node == node)
+	list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
+		entity = to_xvip_entity(asd);
+		if (entity->asd.match.fwnode == fwnode)
 			return entity;
 	}
 
@@ -75,22 +78,23 @@ static int xvip_graph_build_one(struct xvip_composite_device *xdev,
 	struct media_pad *remote_pad;
 	struct xvip_graph_entity *ent;
 	struct v4l2_fwnode_link link;
-	struct device_node *ep = NULL;
+	struct fwnode_handle *ep = NULL;
 	int ret = 0;
 
 	dev_dbg(xdev->dev, "creating links for entity %s\n", local->name);
 
 	while (1) {
 		/* Get the next endpoint and parse its link. */
-		ep = of_graph_get_next_endpoint(entity->node, ep);
+		ep = fwnode_graph_get_next_endpoint(entity->asd.match.fwnode,
+						    ep);
 		if (ep == NULL)
 			break;
 
-		dev_dbg(xdev->dev, "processing endpoint %pOF\n", ep);
+		dev_dbg(xdev->dev, "processing endpoint %p\n", ep);
 
-		ret = v4l2_fwnode_parse_link(of_fwnode_handle(ep), &link);
+		ret = v4l2_fwnode_parse_link(ep, &link);
 		if (ret < 0) {
-			dev_err(xdev->dev, "failed to parse link for %pOF\n",
+			dev_err(xdev->dev, "failed to parse link for %p\n",
 				ep);
 			continue;
 		}
@@ -99,9 +103,8 @@ static int xvip_graph_build_one(struct xvip_composite_device *xdev,
 		 * the link.
 		 */
 		if (link.local_port >= local->num_pads) {
-			dev_err(xdev->dev, "invalid port number %u for %pOF\n",
-				link.local_port,
-				to_of_node(link.local_node));
+			dev_err(xdev->dev, "invalid port number %u for %p\n",
+				link.local_port, link.local_node);
 			v4l2_fwnode_put_link(&link);
 			ret = -EINVAL;
 			break;
@@ -110,28 +113,25 @@ static int xvip_graph_build_one(struct xvip_composite_device *xdev,
 		local_pad = &local->pads[link.local_port];
 
 		if (local_pad->flags & MEDIA_PAD_FL_SINK) {
-			dev_dbg(xdev->dev, "skipping sink port %pOF:%u\n",
-				to_of_node(link.local_node),
-				link.local_port);
+			dev_dbg(xdev->dev, "skipping sink port %p:%u\n",
+				link.local_node, link.local_port);
 			v4l2_fwnode_put_link(&link);
 			continue;
 		}
 
 		/* Skip DMA engines, they will be processed separately. */
 		if (link.remote_node == of_fwnode_handle(xdev->dev->of_node)) {
-			dev_dbg(xdev->dev, "skipping DMA port %pOF:%u\n",
-				to_of_node(link.local_node),
-				link.local_port);
+			dev_dbg(xdev->dev, "skipping DMA port %p:%u\n",
+				link.local_node, link.local_port);
 			v4l2_fwnode_put_link(&link);
 			continue;
 		}
 
 		/* Find the remote entity. */
-		ent = xvip_graph_find_entity(xdev,
-					     to_of_node(link.remote_node));
+		ent = xvip_graph_find_entity(xdev, link.remote_node);
 		if (ent == NULL) {
-			dev_err(xdev->dev, "no entity found for %pOF\n",
-				to_of_node(link.remote_node));
+			dev_err(xdev->dev, "no entity found for %p\n",
+				link.remote_node);
 			v4l2_fwnode_put_link(&link);
 			ret = -ENODEV;
 			break;
@@ -140,8 +140,8 @@ static int xvip_graph_build_one(struct xvip_composite_device *xdev,
 		remote = ent->entity;
 
 		if (link.remote_port >= remote->num_pads) {
-			dev_err(xdev->dev, "invalid port number %u on %pOF\n",
-				link.remote_port, to_of_node(link.remote_node));
+			dev_err(xdev->dev, "invalid port number %u on %p\n",
+				link.remote_port, link.remote_node);
 			v4l2_fwnode_put_link(&link);
 			ret = -EINVAL;
 			break;
@@ -168,7 +168,7 @@ static int xvip_graph_build_one(struct xvip_composite_device *xdev,
 		}
 	}
 
-	of_node_put(ep);
+	fwnode_handle_put(ep);
 	return ret;
 }
 
@@ -230,8 +230,7 @@ static int xvip_graph_build_dma(struct xvip_composite_device *xdev)
 			dma->video.name);
 
 		/* Find the remote entity. */
-		ent = xvip_graph_find_entity(xdev,
-					     to_of_node(link.remote_node));
+		ent = xvip_graph_find_entity(xdev, link.remote_node);
 		if (ent == NULL) {
 			dev_err(xdev->dev, "no entity found for %pOF\n",
 				to_of_node(link.remote_node));
@@ -289,12 +288,14 @@ static int xvip_graph_notify_complete(struct v4l2_async_notifier *notifier)
 	struct xvip_composite_device *xdev =
 		container_of(notifier, struct xvip_composite_device, notifier);
 	struct xvip_graph_entity *entity;
+	struct v4l2_async_subdev *asd;
 	int ret;
 
 	dev_dbg(xdev->dev, "notify complete, all subdevs registered\n");
 
 	/* Create links for every entity. */
-	list_for_each_entry(entity, &xdev->entities, list) {
+	list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
+		entity = to_xvip_entity(asd);
 		ret = xvip_graph_build_one(xdev, entity);
 		if (ret < 0)
 			return ret;
@@ -314,22 +315,25 @@ static int xvip_graph_notify_complete(struct v4l2_async_notifier *notifier)
 
 static int xvip_graph_notify_bound(struct v4l2_async_notifier *notifier,
 				   struct v4l2_subdev *subdev,
-				   struct v4l2_async_subdev *asd)
+				   struct v4l2_async_subdev *unused)
 {
 	struct xvip_composite_device *xdev =
 		container_of(notifier, struct xvip_composite_device, notifier);
 	struct xvip_graph_entity *entity;
+	struct v4l2_async_subdev *asd;
 
 	/* Locate the entity corresponding to the bound subdev and store the
 	 * subdev pointer.
 	 */
-	list_for_each_entry(entity, &xdev->entities, list) {
-		if (entity->node != subdev->dev->of_node)
+	list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
+		entity = to_xvip_entity(asd);
+
+		if (entity->asd.match.fwnode != subdev->fwnode)
 			continue;
 
 		if (entity->subdev) {
-			dev_err(xdev->dev, "duplicate subdev for node %pOF\n",
-				entity->node);
+			dev_err(xdev->dev, "duplicate subdev for node %p\n",
+				entity->asd.match.fwnode);
 			return -EINVAL;
 		}
 
@@ -349,56 +353,60 @@ static const struct v4l2_async_notifier_operations xvip_graph_notify_ops = {
 };
 
 static int xvip_graph_parse_one(struct xvip_composite_device *xdev,
-				struct device_node *node)
+				struct fwnode_handle *fwnode)
 {
-	struct xvip_graph_entity *entity;
-	struct device_node *remote;
-	struct device_node *ep = NULL;
+	struct fwnode_handle *remote;
+	struct fwnode_handle *ep = NULL;
 	int ret = 0;
 
-	dev_dbg(xdev->dev, "parsing node %pOF\n", node);
+	dev_dbg(xdev->dev, "parsing node %p\n", fwnode);
 
 	while (1) {
-		ep = of_graph_get_next_endpoint(node, ep);
+		struct v4l2_async_subdev *asd;
+
+		ep = fwnode_graph_get_next_endpoint(fwnode, ep);
 		if (ep == NULL)
 			break;
 
-		dev_dbg(xdev->dev, "handling endpoint %pOF\n", ep);
+		dev_dbg(xdev->dev, "handling endpoint %p\n", ep);
 
-		remote = of_graph_get_remote_port_parent(ep);
+		remote = fwnode_graph_get_remote_port_parent(ep);
 		if (remote == NULL) {
 			ret = -EINVAL;
-			break;
+			goto err_notifier_cleanup;
 		}
 
+		fwnode_handle_put(ep);
+
 		/* Skip entities that we have already processed. */
-		if (remote == xdev->dev->of_node ||
+		if (remote == of_fwnode_handle(xdev->dev->of_node) ||
 		    xvip_graph_find_entity(xdev, remote)) {
-			of_node_put(remote);
+			fwnode_handle_put(remote);
 			continue;
 		}
 
-		entity = devm_kzalloc(xdev->dev, sizeof(*entity), GFP_KERNEL);
-		if (entity == NULL) {
-			of_node_put(remote);
-			ret = -ENOMEM;
-			break;
+		asd = v4l2_async_notifier_add_fwnode_subdev(
+			&xdev->notifier, remote,
+			sizeof(struct xvip_graph_entity));
+		if (IS_ERR(asd)) {
+			ret = PTR_ERR(asd);
+			fwnode_handle_put(remote);
+			goto err_notifier_cleanup;
 		}
-
-		entity->node = remote;
-		entity->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-		entity->asd.match.fwnode = of_fwnode_handle(remote);
-		list_add_tail(&entity->list, &xdev->entities);
-		xdev->num_subdevs++;
 	}
 
-	of_node_put(ep);
+	return 0;
+
+err_notifier_cleanup:
+	v4l2_async_notifier_cleanup(&xdev->notifier);
+	fwnode_handle_put(ep);
 	return ret;
 }
 
 static int xvip_graph_parse(struct xvip_composite_device *xdev)
 {
 	struct xvip_graph_entity *entity;
+	struct v4l2_async_subdev *asd;
 	int ret;
 
 	/*
@@ -407,14 +415,17 @@ static int xvip_graph_parse(struct xvip_composite_device *xdev)
 	 * loop will handle entities added at the end of the list while walking
 	 * the links.
 	 */
-	ret = xvip_graph_parse_one(xdev, xdev->dev->of_node);
+	ret = xvip_graph_parse_one(xdev, of_fwnode_handle(xdev->dev->of_node));
 	if (ret < 0)
 		return 0;
 
-	list_for_each_entry(entity, &xdev->entities, list) {
-		ret = xvip_graph_parse_one(xdev, entity->node);
-		if (ret < 0)
+	list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
+		entity = to_xvip_entity(asd);
+		ret = xvip_graph_parse_one(xdev, entity->asd.match.fwnode);
+		if (ret < 0) {
+			v4l2_async_notifier_cleanup(&xdev->notifier);
 			break;
+		}
 	}
 
 	return ret;
@@ -485,17 +496,11 @@ static int xvip_graph_dma_init(struct xvip_composite_device *xdev)
 
 static void xvip_graph_cleanup(struct xvip_composite_device *xdev)
 {
-	struct xvip_graph_entity *entityp;
-	struct xvip_graph_entity *entity;
 	struct xvip_dma *dmap;
 	struct xvip_dma *dma;
 
 	v4l2_async_notifier_unregister(&xdev->notifier);
-
-	list_for_each_entry_safe(entity, entityp, &xdev->entities, list) {
-		of_node_put(entity->node);
-		list_del(&entity->list);
-	}
+	v4l2_async_notifier_cleanup(&xdev->notifier);
 
 	list_for_each_entry_safe(dma, dmap, &xdev->dmas, list) {
 		xvip_dma_cleanup(dma);
@@ -505,10 +510,6 @@ static void xvip_graph_cleanup(struct xvip_composite_device *xdev)
 
 static int xvip_graph_init(struct xvip_composite_device *xdev)
 {
-	struct xvip_graph_entity *entity;
-	struct v4l2_async_subdev **subdevs = NULL;
-	unsigned int num_subdevs;
-	unsigned int i;
 	int ret;
 
 	/* Init the DMA channels. */
@@ -525,26 +526,12 @@ static int xvip_graph_init(struct xvip_composite_device *xdev)
 		goto done;
 	}
 
-	if (!xdev->num_subdevs) {
+	if (list_empty(&xdev->notifier.asd_list)) {
 		dev_err(xdev->dev, "no subdev found in graph\n");
 		goto done;
 	}
 
 	/* Register the subdevices notifier. */
-	num_subdevs = xdev->num_subdevs;
-	subdevs = devm_kcalloc(xdev->dev, num_subdevs, sizeof(*subdevs),
-			       GFP_KERNEL);
-	if (subdevs == NULL) {
-		ret = -ENOMEM;
-		goto done;
-	}
-
-	i = 0;
-	list_for_each_entry(entity, &xdev->entities, list)
-		subdevs[i++] = &entity->asd;
-
-	xdev->notifier.subdevs = subdevs;
-	xdev->notifier.num_subdevs = num_subdevs;
 	xdev->notifier.ops = &xvip_graph_notify_ops;
 
 	ret = v4l2_async_notifier_register(&xdev->v4l2_dev, &xdev->notifier);
@@ -610,8 +597,8 @@ static int xvip_composite_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	xdev->dev = &pdev->dev;
-	INIT_LIST_HEAD(&xdev->entities);
 	INIT_LIST_HEAD(&xdev->dmas);
+	v4l2_async_notifier_init(&xdev->notifier);
 
 	ret = xvip_composite_v4l2_init(xdev);
 	if (ret < 0)
diff --git a/drivers/media/platform/xilinx/xilinx-vipp.h b/drivers/media/platform/xilinx/xilinx-vipp.h
index faf6b6e80b3b..7e9c4cff33b4 100644
--- a/drivers/media/platform/xilinx/xilinx-vipp.h
+++ b/drivers/media/platform/xilinx/xilinx-vipp.h
@@ -28,8 +28,6 @@
  * @media_dev: media device
  * @dev: (OF) device
  * @notifier: V4L2 asynchronous subdevs notifier
- * @entities: entities in the graph as a list of xvip_graph_entity
- * @num_subdevs: number of subdevs in the pipeline
  * @dmas: list of DMA channels at the pipeline output and input
  * @v4l2_caps: V4L2 capabilities of the whole device (see VIDIOC_QUERYCAP)
  */
@@ -39,8 +37,6 @@ struct xvip_composite_device {
 	struct device *dev;
 
 	struct v4l2_async_notifier notifier;
-	struct list_head entities;
-	unsigned int num_subdevs;
 
 	struct list_head dmas;
 	u32 v4l2_caps;