1 files changed, 382 insertions, 145 deletions

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index e5eb27375416..16a8301c25d6 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -6,16 +6,29 @@
  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
  */
 
+#include <linux/container_of.h>
 #include <linux/device.h>
-#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/kobject.h>
+#include <linux/kstrtox.h>
+#include <linux/list.h>
 #include <linux/property.h>
 #include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include "base.h"
 
 struct swnode {
-	int id;
 	struct kobject kobj;
 	struct fwnode_handle fwnode;
 	const struct software_node *node;
+	int id;
 
 	/* hierarchy */
 	struct ida child_ids;
@@ -24,6 +37,7 @@ struct swnode {
 	struct swnode *parent;
 
 	unsigned int allocated:1;
+	unsigned int managed:1;
 };
 
 static DEFINE_IDA(swnode_root_ids);
@@ -48,6 +62,19 @@ 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)
 {
@@ -397,9 +424,6 @@ software_node_get_name(const struct fwnode_handle *fwnode)
 {
 	const struct swnode *swnode = to_swnode(fwnode);
 
-	if (!swnode)
-		return "(null)";
-
 	return kobject_name(&swnode->kobj);
 }
 
@@ -443,14 +467,18 @@ 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 *
@@ -487,9 +515,6 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
 	int error;
 	int i;
 
-	if (!swnode)
-		return -ENOENT;
-
 	prop = property_entry_get(swnode->node->properties, propname);
 	if (!prop)
 		return -ENOENT;
@@ -504,20 +529,35 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
 	if (prop->is_inline)
 		return -EINVAL;
 
-	if (index * sizeof(*ref) >= prop->length)
+	if ((index + 1) * sizeof(*ref) > prop->length)
 		return -ENOENT;
 
 	ref_array = prop->pointer;
 	ref = &ref_array[index];
 
-	refnode = software_node_fwnode(ref->node);
+	/*
+	 * A software node can reference other software nodes or firmware
+	 * nodes (which are the abstraction layer sitting on top of them).
+	 * This is done to ensure we can create references to static software
+	 * nodes before they're registered with the firmware node framework.
+	 * At the time the reference is being resolved, we expect the swnodes
+	 * in question to already have been registered and to be backed by
+	 * a firmware node. This is why we use the fwnode API below to read the
+	 * relevant properties and bump the reference count.
+	 */
+
+	if (ref->swnode)
+		refnode = software_node_fwnode(ref->swnode);
+	else if (ref->fwnode)
+		refnode = ref->fwnode;
+	else
+		return -EINVAL;
+
 	if (!refnode)
 		return -ENOENT;
 
 	if (nargs_prop) {
-		error = property_entry_read_int_array(swnode->node->properties,
-						      nargs_prop, sizeof(u32),
-						      &nargs_prop_val, 1);
+		error = fwnode_property_read_u32(refnode, nargs_prop, &nargs_prop_val);
 		if (error)
 			return error;
 
@@ -527,7 +567,10 @@ software_node_get_reference_args(const struct fwnode_handle *fwnode,
 	if (nargs > NR_FWNODE_REFERENCE_ARGS)
 		return -EINVAL;
 
-	args->fwnode = software_node_get(refnode);
+	if (!args)
+		return 0;
+
+	args->fwnode = fwnode_handle_get(refnode);
 	args->nargs = nargs;
 
 	for (i = 0; i < nargs; i++)
@@ -536,10 +579,123 @@ 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;
+
+	if (!ref->swnode)
+		return NULL;
+
+	return software_node_get(software_node_fwnode(ref->swnode));
+}
+
+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,
 	.property_present = software_node_property_present,
+	.property_read_bool = software_node_property_present,
 	.property_read_int_array = software_node_read_int_array,
 	.property_read_string_array = software_node_read_string_array,
 	.get_name = software_node_get_name,
@@ -547,7 +703,11 @@ 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,
 };
 
 /* -------------------------------------------------------------------------- */
@@ -589,19 +749,30 @@ software_node_find_by_name(const struct software_node *parent, const char *name)
 }
 EXPORT_SYMBOL_GPL(software_node_find_by_name);
 
-static int
-software_node_register_properties(struct software_node *node,
-				  const struct property_entry *properties)
+static struct software_node *software_node_alloc(const struct property_entry *properties)
 {
 	struct property_entry *props;
+	struct software_node *node;
 
 	props = property_entries_dup(properties);
 	if (IS_ERR(props))
-		return PTR_ERR(props);
+		return ERR_CAST(props);
+
+	node = kzalloc(sizeof(*node), GFP_KERNEL);
+	if (!node) {
+		property_entries_free(props);
+		return ERR_PTR(-ENOMEM);
+	}
 
 	node->properties = props;
 
-	return 0;
+	return node;
+}
+
+static void software_node_free(const struct software_node *node)
+{
+	property_entries_free(node->properties);
+	kfree(node);
 }
 
 static void software_node_release(struct kobject *kobj)
@@ -609,21 +780,20 @@ static void software_node_release(struct kobject *kobj)
 	struct swnode *swnode = kobj_to_swnode(kobj);
 
 	if (swnode->parent) {
-		ida_simple_remove(&swnode->parent->child_ids, swnode->id);
+		ida_free(&swnode->parent->child_ids, swnode->id);
 		list_del(&swnode->entry);
 	} else {
-		ida_simple_remove(&swnode_root_ids, swnode->id);
+		ida_free(&swnode_root_ids, swnode->id);
 	}
 
-	if (swnode->allocated) {
-		property_entries_free(swnode->node->properties);
-		kfree(swnode->node);
-	}
+	if (swnode->allocated)
+		software_node_free(swnode->node);
+
 	ida_destroy(&swnode->child_ids);
 	kfree(swnode);
 }
 
-static struct kobj_type software_node_type = {
+static const struct kobj_type software_node_type = {
 	.release = software_node_release,
 	.sysfs_ops = &kobj_sysfs_ops,
 };
@@ -636,24 +806,21 @@ swnode_register(const struct software_node *node, struct swnode *parent,
 	int ret;
 
 	swnode = kzalloc(sizeof(*swnode), GFP_KERNEL);
-	if (!swnode) {
-		ret = -ENOMEM;
-		goto out_err;
-	}
+	if (!swnode)
+		return ERR_PTR(-ENOMEM);
 
-	ret = ida_simple_get(parent ? &parent->child_ids : &swnode_root_ids,
-			     0, 0, GFP_KERNEL);
+	ret = ida_alloc(parent ? &parent->child_ids : &swnode_root_ids,
+			GFP_KERNEL);
 	if (ret < 0) {
 		kfree(swnode);
-		goto out_err;
+		return ERR_PTR(ret);
 	}
 
 	swnode->id = ret;
 	swnode->node = node;
 	swnode->parent = parent;
-	swnode->allocated = allocated;
 	swnode->kobj.kset = swnode_kset;
-	swnode->fwnode.ops = &software_node_ops;
+	fwnode_init(&swnode->fwnode, &software_node_ops);
 
 	ida_init(&swnode->child_ids);
 	INIT_LIST_HEAD(&swnode->entry);
@@ -672,68 +839,30 @@ swnode_register(const struct software_node *node, struct swnode *parent,
 		return ERR_PTR(ret);
 	}
 
+	/*
+	 * Assign the flag only in the successful case, so
+	 * the above kobject_put() won't mess up with properties.
+	 */
+	swnode->allocated = allocated;
+
 	if (parent)
 		list_add_tail(&swnode->entry, &parent->children);
 
 	kobject_uevent(&swnode->kobj, KOBJ_ADD);
 	return &swnode->fwnode;
-
-out_err:
-	if (allocated)
-		property_entries_free(node->properties);
-	return ERR_PTR(ret);
 }
 
 /**
- * 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.
- */
-int software_node_register_nodes(const struct software_node *nodes)
-{
-	int ret;
-	int i;
-
-	for (i = 0; nodes[i].name; i++) {
-		ret = software_node_register(&nodes[i]);
-		if (ret) {
-			software_node_unregister_nodes(nodes);
-			return ret;
-		}
-	}
-
-	return 0;
-}
-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.
- *
- * 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.
- */
-void software_node_unregister_nodes(const struct software_node *nodes)
-{
-	int i;
-
-	for (i = 0; nodes[i].name; i++)
-		software_node_unregister(&nodes[i]);
-}
-EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
-
-/**
  * software_node_register_node_group - Register a group of software nodes
  * @node_group: NULL terminated array of software node pointers 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_node_group(const struct software_node **node_group)
+int software_node_register_node_group(const struct software_node * const *node_group)
 {
 	unsigned int i;
 	int ret;
@@ -757,21 +886,27 @@ 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. 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: 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_node_group(const struct software_node **node_group)
+void software_node_unregister_node_group(const struct software_node * const *node_group)
 {
-	struct swnode *swnode;
-	unsigned int i;
+	unsigned int i = 0;
 
 	if (!node_group)
 		return;
 
-	for (i = 0; node_group[i]; i++) {
-		swnode = software_node_to_swnode(node_group[i]);
-		if (swnode)
-			fwnode_remove_software_node(&swnode->fwnode);
-	}
+	while (node_group[i])
+		i++;
+
+	while (i--)
+		software_node_unregister(node_group[i]);
 }
 EXPORT_SYMBOL_GPL(software_node_unregister_node_group);
 
@@ -786,6 +921,9 @@ int software_node_register(const struct software_node *node)
 	if (software_node_to_swnode(node))
 		return -EEXIST;
 
+	if (node->parent && !parent)
+		return -EINVAL;
+
 	return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0));
 }
 EXPORT_SYMBOL_GPL(software_node_register);
@@ -808,31 +946,28 @@ struct fwnode_handle *
 fwnode_create_software_node(const struct property_entry *properties,
 			    const struct fwnode_handle *parent)
 {
+	struct fwnode_handle *fwnode;
 	struct software_node *node;
-	struct swnode *p = NULL;
-	int ret;
+	struct swnode *p;
 
-	if (parent) {
-		if (IS_ERR(parent))
-			return ERR_CAST(parent);
-		if (!is_software_node(parent))
-			return ERR_PTR(-EINVAL);
-		p = to_swnode(parent);
-	}
+	if (IS_ERR(parent))
+		return ERR_CAST(parent);
 
-	node = kzalloc(sizeof(*node), GFP_KERNEL);
-	if (!node)
-		return ERR_PTR(-ENOMEM);
+	p = to_swnode(parent);
+	if (parent && !p)
+		return ERR_PTR(-EINVAL);
 
-	ret = software_node_register_properties(node, properties);
-	if (ret) {
-		kfree(node);
-		return ERR_PTR(ret);
-	}
+	node = software_node_alloc(properties);
+	if (IS_ERR(node))
+		return ERR_CAST(node);
 
 	node->parent = p ? p->node : NULL;
 
-	return swnode_register(node, p, 1);
+	fwnode = swnode_register(node, p, 1);
+	if (IS_ERR(fwnode))
+		software_node_free(node);
+
+	return fwnode;
 }
 EXPORT_SYMBOL_GPL(fwnode_create_software_node);
 
@@ -847,47 +982,149 @@ void fwnode_remove_software_node(struct fwnode_handle *fwnode)
 }
 EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
 
-int software_node_notify(struct device *dev, unsigned long action)
+/**
+ * device_add_software_node - Assign software node to a device
+ * @dev: The device the software node is meant for.
+ * @node: The software node.
+ *
+ * This function will make @node the secondary firmware node pointer of @dev. If
+ * @dev has no primary node, then @node will become the primary node. The
+ * function will register @node automatically if it wasn't already registered.
+ */
+int device_add_software_node(struct device *dev, const struct software_node *node)
 {
-	struct fwnode_handle *fwnode = dev_fwnode(dev);
 	struct swnode *swnode;
 	int ret;
 
-	if (!fwnode)
-		return 0;
+	/* Only one software node per device. */
+	if (dev_to_swnode(dev))
+		return -EBUSY;
 
-	if (!is_software_node(fwnode))
-		fwnode = fwnode->secondary;
-	if (!is_software_node(fwnode))
-		return 0;
+	swnode = software_node_to_swnode(node);
+	if (swnode) {
+		kobject_get(&swnode->kobj);
+	} else {
+		ret = software_node_register(node);
+		if (ret)
+			return ret;
 
-	swnode = to_swnode(fwnode);
+		swnode = software_node_to_swnode(node);
+	}
 
-	switch (action) {
-	case KOBJ_ADD:
-		ret = sysfs_create_link(&dev->kobj, &swnode->kobj,
-					"software_node");
-		if (ret)
-			break;
+	set_secondary_fwnode(dev, &swnode->fwnode);
 
-		ret = sysfs_create_link(&swnode->kobj, &dev->kobj,
-					dev_name(dev));
-		if (ret) {
-			sysfs_remove_link(&dev->kobj, "software_node");
-			break;
-		}
-		kobject_get(&swnode->kobj);
-		break;
-	case KOBJ_REMOVE:
-		sysfs_remove_link(&swnode->kobj, dev_name(dev));
+	/*
+	 * If the device has been fully registered by the time this function is
+	 * called, software_node_notify() must be called separately so that the
+	 * symlinks get created and the reference count of the node is kept in
+	 * balance.
+	 */
+	if (device_is_registered(dev))
+		software_node_notify(dev);
+
+	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;
+
+	if (device_is_registered(dev))
+		software_node_notify_remove(dev);
+
+	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);
+
+	if (device_is_registered(dev))
+		software_node_notify(dev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(device_create_managed_software_node);
+
+void software_node_notify(struct device *dev)
+{
+	struct swnode *swnode;
+	int ret;
+
+	swnode = dev_to_swnode(dev);
+	if (!swnode)
+		return;
+
+	kobject_get(&swnode->kobj);
+	ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node");
+	if (ret)
+		return;
+
+	ret = sysfs_create_link(&swnode->kobj, &dev->kobj, dev_name(dev));
+	if (ret) {
 		sysfs_remove_link(&dev->kobj, "software_node");
-		kobject_put(&swnode->kobj);
-		break;
-	default:
-		break;
+		return;
 	}
+}
 
-	return 0;
+void software_node_notify_remove(struct device *dev)
+{
+	struct swnode *swnode;
+
+	swnode = dev_to_swnode(dev);
+	if (!swnode)
+		return;
+
+	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);
+	}
 }
 
 static int __init software_node_init(void)