1 files changed, 151 insertions, 0 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 1b95a405628f..5f81bfea5246 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -21,6 +21,7 @@
 #include <linux/cpu.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_graph.h>
 #include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <linux/proc_fs.h>
@@ -2014,3 +2015,153 @@ struct device_node *of_find_next_cache_node(const struct device_node *np)
 
 	return NULL;
 }
+
+/**
+ * of_graph_parse_endpoint() - parse common endpoint node properties
+ * @node: pointer to endpoint device_node
+ * @endpoint: pointer to the OF endpoint data structure
+ *
+ * The caller should hold a reference to @node.
+ */
+int of_graph_parse_endpoint(const struct device_node *node,
+			    struct of_endpoint *endpoint)
+{
+	struct device_node *port_node = of_get_parent(node);
+
+	WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
+		  __func__, node->full_name);
+
+	memset(endpoint, 0, sizeof(*endpoint));
+
+	endpoint->local_node = node;
+	/*
+	 * It doesn't matter whether the two calls below succeed.
+	 * If they don't then the default value 0 is used.
+	 */
+	of_property_read_u32(port_node, "reg", &endpoint->port);
+	of_property_read_u32(node, "reg", &endpoint->id);
+
+	of_node_put(port_node);
+
+	return 0;
+}
+EXPORT_SYMBOL(of_graph_parse_endpoint);
+
+/**
+ * of_graph_get_next_endpoint() - get next endpoint node
+ * @parent: pointer to the parent device node
+ * @prev: previous endpoint node, or NULL to get first
+ *
+ * Return: An 'endpoint' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is not decremented, the caller have to use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
+					struct device_node *prev)
+{
+	struct device_node *endpoint;
+	struct device_node *port = NULL;
+
+	if (!parent)
+		return NULL;
+
+	if (!prev) {
+		struct device_node *node;
+		/*
+		 * It's the first call, we have to find a port subnode
+		 * within this node or within an optional 'ports' node.
+		 */
+		node = of_get_child_by_name(parent, "ports");
+		if (node)
+			parent = node;
+
+		port = of_get_child_by_name(parent, "port");
+
+		if (port) {
+			/* Found a port, get an endpoint. */
+			endpoint = of_get_next_child(port, NULL);
+			of_node_put(port);
+		} else {
+			endpoint = NULL;
+		}
+
+		if (!endpoint)
+			pr_err("%s(): no endpoint nodes specified for %s\n",
+			       __func__, parent->full_name);
+		of_node_put(node);
+
+		return endpoint;
+	}
+
+	port = of_get_parent(prev);
+	if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
+		      __func__, prev->full_name))
+		return NULL;
+
+	/* Avoid dropping prev node refcount to 0. */
+	of_node_get(prev);
+	endpoint = of_get_next_child(port, prev);
+	if (endpoint) {
+		of_node_put(port);
+		return endpoint;
+	}
+
+	/* No more endpoints under this port, try the next one. */
+	do {
+		port = of_get_next_child(parent, port);
+		if (!port)
+			return NULL;
+	} while (of_node_cmp(port->name, "port"));
+
+	/* Pick up the first endpoint in this port. */
+	endpoint = of_get_next_child(port, NULL);
+	of_node_put(port);
+
+	return endpoint;
+}
+EXPORT_SYMBOL(of_graph_get_next_endpoint);
+
+/**
+ * of_graph_get_remote_port_parent() - get remote port's parent node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote device node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port_parent(
+			       const struct device_node *node)
+{
+	struct device_node *np;
+	unsigned int depth;
+
+	/* Get remote endpoint node. */
+	np = of_parse_phandle(node, "remote-endpoint", 0);
+
+	/* Walk 3 levels up only if there is 'ports' node. */
+	for (depth = 3; depth && np; depth--) {
+		np = of_get_next_parent(np);
+		if (depth == 2 && of_node_cmp(np->name, "ports"))
+			break;
+	}
+	return np;
+}
+EXPORT_SYMBOL(of_graph_get_remote_port_parent);
+
+/**
+ * of_graph_get_remote_port() - get remote port node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote port node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port(const struct device_node *node)
+{
+	struct device_node *np;
+
+	/* Get remote endpoint node. */
+	np = of_parse_phandle(node, "remote-endpoint", 0);
+	if (!np)
+		return NULL;
+	return of_get_next_parent(np);
+}
+EXPORT_SYMBOL(of_graph_get_remote_port);