1 files changed, 266 insertions, 28 deletions

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 4a4b2008fbc2..37179a8b1ceb 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -24,6 +24,7 @@ struct swnode {
 	struct swnode *parent;
 
 	unsigned int allocated:1;
+	unsigned int managed:1;
 };
 
 static DEFINE_IDA(swnode_root_ids);
@@ -48,6 +49,19 @@ EXPORT_SYMBOL_GPL(is_software_node);
 				     struct swnode, fwnode) : NULL;	\
 	})
 
+static inline struct swnode *dev_to_swnode(struct device *dev)
+{
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
+
+	if (!fwnode)
+		return NULL;
+
+	if (!is_software_node(fwnode))
+		fwnode = fwnode->secondary;
+
+	return to_swnode(fwnode);
+}
+
 static struct swnode *
 software_node_to_swnode(const struct software_node *node)
 {
@@ -443,14 +457,18 @@ software_node_get_next_child(const struct fwnode_handle *fwnode,
 	struct swnode *c = to_swnode(child);
 
 	if (!p || list_empty(&p->children) ||
-	    (c && list_is_last(&c->entry, &p->children)))
+	    (c && list_is_last(&c->entry, &p->children))) {
+		fwnode_handle_put(child);
 		return NULL;
+	}
 
 	if (c)
 		c = list_next_entry(c, entry);
 	else
 		c = list_first_entry(&p->children, struct swnode, entry);
-	return &c->fwnode;
+
+	fwnode_handle_put(child);
+	return fwnode_handle_get(&c->fwnode);
 }
 
 static struct fwnode_handle *
@@ -536,6 +554,115 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
 	return 0;
 }
 
+static struct fwnode_handle *
+swnode_graph_find_next_port(const struct fwnode_handle *parent,
+			    struct fwnode_handle *port)
+{
+	struct fwnode_handle *old = port;
+
+	while ((port = software_node_get_next_child(parent, old))) {
+		/*
+		 * fwnode ports have naming style "port@", so we search for any
+		 * children that follow that convention.
+		 */
+		if (!strncmp(to_swnode(port)->node->name, "port@",
+			     strlen("port@")))
+			return port;
+		old = port;
+	}
+
+	return NULL;
+}
+
+static struct fwnode_handle *
+software_node_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
+				      struct fwnode_handle *endpoint)
+{
+	struct swnode *swnode = to_swnode(fwnode);
+	struct fwnode_handle *parent;
+	struct fwnode_handle *port;
+
+	if (!swnode)
+		return NULL;
+
+	if (endpoint) {
+		port = software_node_get_parent(endpoint);
+		parent = software_node_get_parent(port);
+	} else {
+		parent = software_node_get_named_child_node(fwnode, "ports");
+		if (!parent)
+			parent = software_node_get(&swnode->fwnode);
+
+		port = swnode_graph_find_next_port(parent, NULL);
+	}
+
+	for (; port; port = swnode_graph_find_next_port(parent, port)) {
+		endpoint = software_node_get_next_child(port, endpoint);
+		if (endpoint) {
+			fwnode_handle_put(port);
+			break;
+		}
+	}
+
+	fwnode_handle_put(parent);
+
+	return endpoint;
+}
+
+static struct fwnode_handle *
+software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
+{
+	struct swnode *swnode = to_swnode(fwnode);
+	const struct software_node_ref_args *ref;
+	const struct property_entry *prop;
+
+	if (!swnode)
+		return NULL;
+
+	prop = property_entry_get(swnode->node->properties, "remote-endpoint");
+	if (!prop || prop->type != DEV_PROP_REF || prop->is_inline)
+		return NULL;
+
+	ref = prop->pointer;
+
+	return software_node_get(software_node_fwnode(ref[0].node));
+}
+
+static struct fwnode_handle *
+software_node_graph_get_port_parent(struct fwnode_handle *fwnode)
+{
+	struct swnode *swnode = to_swnode(fwnode);
+
+	swnode = swnode->parent;
+	if (swnode && !strcmp(swnode->node->name, "ports"))
+		swnode = swnode->parent;
+
+	return swnode ? software_node_get(&swnode->fwnode) : NULL;
+}
+
+static int
+software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
+				   struct fwnode_endpoint *endpoint)
+{
+	struct swnode *swnode = to_swnode(fwnode);
+	const char *parent_name = swnode->parent->node->name;
+	int ret;
+
+	if (strlen("port@") >= strlen(parent_name) ||
+	    strncmp(parent_name, "port@", strlen("port@")))
+		return -EINVAL;
+
+	/* Ports have naming style "port@n", we need to select the n */
+	ret = kstrtou32(parent_name + strlen("port@"), 10, &endpoint->port);
+	if (ret)
+		return ret;
+
+	endpoint->id = swnode->id;
+	endpoint->local_fwnode = fwnode;
+
+	return 0;
+}
+
 static const struct fwnode_operations software_node_ops = {
 	.get = software_node_get,
 	.put = software_node_put,
@@ -547,7 +674,11 @@ static const struct fwnode_operations software_node_ops = {
 	.get_parent = software_node_get_parent,
 	.get_next_child_node = software_node_get_next_child,
 	.get_named_child_node = software_node_get_named_child_node,
-	.get_reference_args = software_node_get_reference_args
+	.get_reference_args = software_node_get_reference_args,
+	.graph_get_next_endpoint = software_node_graph_get_next_endpoint,
+	.graph_get_remote_endpoint = software_node_graph_get_remote_endpoint,
+	.graph_get_port_parent = software_node_graph_get_port_parent,
+	.graph_parse_endpoint = software_node_graph_parse_endpoint,
 };
 
 /* -------------------------------------------------------------------------- */
@@ -688,7 +819,11 @@ out_err:
  * software_node_register_nodes - Register an array of software nodes
  * @nodes: Zero terminated array of software nodes to be registered
  *
- * Register multiple software nodes at once.
+ * Register multiple software nodes at once. If any node in the array
+ * has its .parent pointer set (which can only be to another software_node),
+ * then its parent **must** have been registered before it is; either outside
+ * of this function or by ordering the array such that parent comes before
+ * child.
  */
 int software_node_register_nodes(const struct software_node *nodes)
 {
@@ -696,14 +831,23 @@ int software_node_register_nodes(const struct software_node *nodes)
 	int i;
 
 	for (i = 0; nodes[i].name; i++) {
-		ret = software_node_register(&nodes[i]);
-		if (ret) {
-			software_node_unregister_nodes(nodes);
-			return ret;
+		const struct software_node *parent = nodes[i].parent;
+
+		if (parent && !software_node_to_swnode(parent)) {
+			ret = -EINVAL;
+			goto err_unregister_nodes;
 		}
+
+		ret = software_node_register(&nodes[i]);
+		if (ret)
+			goto err_unregister_nodes;
 	}
 
 	return 0;
+
+err_unregister_nodes:
+	software_node_unregister_nodes(nodes);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(software_node_register_nodes);
 
@@ -711,18 +855,23 @@ EXPORT_SYMBOL_GPL(software_node_register_nodes);
  * software_node_unregister_nodes - Unregister an array of software nodes
  * @nodes: Zero terminated array of software nodes to be unregistered
  *
- * Unregister multiple software nodes at once.
+ * Unregister multiple software nodes at once. If parent pointers are set up
+ * in any of the software nodes then the array **must** be ordered such that
+ * parents come before their children.
  *
- * NOTE: Be careful using this call if the nodes had parent pointers set up in
- * them before registering.  If so, it is wiser to remove the nodes
- * individually, in the correct order (child before parent) instead of relying
- * on the sequential order of the list of nodes in the array.
+ * NOTE: If you are uncertain whether the array is ordered such that
+ * parents will be unregistered before their children, it is wiser to
+ * remove the nodes individually, in the correct order (child before
+ * parent).
  */
 void software_node_unregister_nodes(const struct software_node *nodes)
 {
-	int i;
+	unsigned int i = 0;
+
+	while (nodes[i].name)
+		i++;
 
-	for (i = 0; nodes[i].name; i++)
+	while (i--)
 		software_node_unregister(&nodes[i]);
 }
 EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
@@ -757,16 +906,23 @@ EXPORT_SYMBOL_GPL(software_node_register_node_group);
  * software_node_unregister_node_group - Unregister a group of software nodes
  * @node_group: NULL terminated array of software node pointers to be unregistered
  *
- * Unregister multiple software nodes at once.
+ * Unregister multiple software nodes at once. The array will be unwound in
+ * reverse order (i.e. last entry first) and thus if any members of the array are
+ * children of another member then the children must appear later in the list such
+ * that they are unregistered first.
  */
-void software_node_unregister_node_group(const struct software_node **node_group)
+void software_node_unregister_node_group(
+		const struct software_node **node_group)
 {
-	unsigned int i;
+	unsigned int i = 0;
 
 	if (!node_group)
 		return;
 
-	for (i = 0; node_group[i]; i++)
+	while (node_group[i])
+		i++;
+
+	while (i--)
 		software_node_unregister(node_group[i]);
 }
 EXPORT_SYMBOL_GPL(software_node_unregister_node_group);
@@ -843,22 +999,99 @@ void fwnode_remove_software_node(struct fwnode_handle *fwnode)
 }
 EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
 
+/**
+ * device_add_software_node - Assign software node to a device
+ * @dev: The device the software node is meant for.
+ * @swnode: The software node.
+ *
+ * This function will register @swnode and make it the secondary firmware node
+ * pointer of @dev. If @dev has no primary node, then @swnode will become the primary
+ * node.
+ */
+int device_add_software_node(struct device *dev, const struct software_node *swnode)
+{
+	int ret;
+
+	/* Only one software node per device. */
+	if (dev_to_swnode(dev))
+		return -EBUSY;
+
+	ret = software_node_register(swnode);
+	if (ret)
+		return ret;
+
+	set_secondary_fwnode(dev, software_node_fwnode(swnode));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(device_add_software_node);
+
+/**
+ * device_remove_software_node - Remove device's software node
+ * @dev: The device with the software node.
+ *
+ * This function will unregister the software node of @dev.
+ */
+void device_remove_software_node(struct device *dev)
+{
+	struct swnode *swnode;
+
+	swnode = dev_to_swnode(dev);
+	if (!swnode)
+		return;
+
+	software_node_notify(dev, KOBJ_REMOVE);
+	set_secondary_fwnode(dev, NULL);
+	kobject_put(&swnode->kobj);
+}
+EXPORT_SYMBOL_GPL(device_remove_software_node);
+
+/**
+ * device_create_managed_software_node - Create a software node for a device
+ * @dev: The device the software node is assigned to.
+ * @properties: Device properties for the software node.
+ * @parent: Parent of the software node.
+ *
+ * Creates a software node as a managed resource for @dev, which means the
+ * lifetime of the newly created software node is tied to the lifetime of @dev.
+ * Software nodes created with this function should not be reused or shared
+ * because of that. The function takes a deep copy of @properties for the
+ * software node.
+ *
+ * Since the new software node is assigned directly to @dev, and since it should
+ * not be shared, it is not returned to the caller. The function returns 0 on
+ * success, and errno in case of an error.
+ */
+int device_create_managed_software_node(struct device *dev,
+					const struct property_entry *properties,
+					const struct software_node *parent)
+{
+	struct fwnode_handle *p = software_node_fwnode(parent);
+	struct fwnode_handle *fwnode;
+
+	if (parent && !p)
+		return -EINVAL;
+
+	fwnode = fwnode_create_software_node(properties, p);
+	if (IS_ERR(fwnode))
+		return PTR_ERR(fwnode);
+
+	to_swnode(fwnode)->managed = true;
+	set_secondary_fwnode(dev, fwnode);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(device_create_managed_software_node);
+
 int software_node_notify(struct device *dev, unsigned long action)
 {
-	struct fwnode_handle *fwnode = dev_fwnode(dev);
 	struct swnode *swnode;
 	int ret;
 
-	if (!fwnode)
-		return 0;
-
-	if (!is_software_node(fwnode))
-		fwnode = fwnode->secondary;
-	if (!is_software_node(fwnode))
+	swnode = dev_to_swnode(dev);
+	if (!swnode)
 		return 0;
 
-	swnode = to_swnode(fwnode);
-
 	switch (action) {
 	case KOBJ_ADD:
 		ret = sysfs_create_link(&dev->kobj, &swnode->kobj,
@@ -878,6 +1111,11 @@ int software_node_notify(struct device *dev, unsigned long action)
 		sysfs_remove_link(&swnode->kobj, dev_name(dev));
 		sysfs_remove_link(&dev->kobj, "software_node");
 		kobject_put(&swnode->kobj);
+
+		if (swnode->managed) {
+			set_secondary_fwnode(dev, NULL);
+			kobject_put(&swnode->kobj);
+		}
 		break;
 	default:
 		break;