[PATCH 2/2] OF: add for_each_port_of_node()

[Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>]

From: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>

We have for_each_endpoint_of_node(), but don't have port version of it.
It is useful if we have it. This patch adds it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
---
 drivers/of/property.c    | 37 +++++++++++++++++++++++++++++++++++++
 include/linux/of_graph.h | 20 ++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/drivers/of/property.c b/drivers/of/property.c
index 3db01ee..2ec4c95 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -585,6 +585,43 @@ struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
 EXPORT_SYMBOL(of_graph_get_port_by_id);
 
 /**
+ * of_graph_get_next_port() - get next port node
+ * @parent: pointer to the parent device node
+ * @prev: previous port node, or NULL to get first
+ *
+ * Return: An 'port' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is decremented.
+ */
+struct device_node *of_graph_get_next_port(const struct device_node *parent,
+					   struct device_node *prev)
+{
+	struct device_node *port;
+
+	if (!parent)
+		return NULL;
+
+	if (!prev) {
+		struct device_node *node;
+
+		node = of_get_child_by_name(parent, "ports");
+		if (node)
+			parent = node;
+		port = NULL;
+	} else {
+		port = prev;
+	}
+
+	do {
+		port = of_get_next_child(parent, port);
+		if (!port)
+			return NULL;
+	} while (of_node_cmp(port->name, "port"));
+
+	return port;
+}
+EXPORT_SYMBOL(of_graph_get_next_port);
+
+/**
  * 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
diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h
index 7fbbf80..d219cc7 100644
--- a/include/linux/of_graph.h
+++ b/include/linux/of_graph.h
@@ -27,6 +27,17 @@ struct of_endpoint {
 };
 
 /**
+ * for_each_port_of_node - iterate over every port in a device node
+ * @parent: parent device node containing ports
+ * @child: loop variable pointing to the current port node
+ *
+ * When breaking out of the loop, of_node_put(child) has to be called manually.
+ */
+#define for_each_port_of_node(parent, child) \
+	for (child = of_graph_get_next_port(parent, NULL); child != NULL; \
+	     child = of_graph_get_next_port(parent, child))
+
+/**
  * for_each_endpoint_of_node - iterate over every endpoint in a device node
  * @parent: parent device node containing ports and endpoints
  * @child: loop variable pointing to the current endpoint node
@@ -44,6 +55,8 @@ int of_graph_parse_endpoint(const struct device_node *node,
 				struct of_endpoint *endpoint);
 int of_graph_get_endpoint_count(const struct device_node *np);
 struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id);
+struct device_node *of_graph_get_next_port(const struct device_node *parent,
+					       struct device_node *previous);
 struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
 					struct device_node *previous);
 struct device_node *of_graph_get_endpoint_by_regs(
@@ -75,6 +88,13 @@ static inline struct device_node *of_graph_get_port_by_id(
 	return NULL;
 }
 
+static inline struct device_node *of_graph_get_next_port(
+					const struct device_node *parent,
+					struct device_node *previous)
+{
+	return NULL;
+}
+
 static inline struct device_node *of_graph_get_next_endpoint(
 					const struct device_node *parent,
 					struct device_node *previous)
-- 
2.7.4