[PATCH v4 03/12] of_graph: add of_graph_get_top_port()

[Kuninori Morimoto]

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

driver want to get top level of port[s] node. This patch adds
of_graph_get_top_port() for this purpose

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
---
v3 -> v4

 - care non-OF case

 drivers/of/base.c        | 24 ++++++++++++++++++++++++
 include/linux/of_graph.h |  7 +++++++
 2 files changed, 31 insertions(+)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index fed0b023..e49eb28 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2330,6 +2330,30 @@ 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_top_port() - get the top port node
+ * @dev: pointer to the device
+ *
+ * Return: A 'port' node pointer with refcount incremented. The caller
+ * has to use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_top_port(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct device_node *node;
+
+	node = of_get_child_by_name(np, "ports");
+	if (node)
+		return node;
+
+	node = of_get_child_by_name(np, "port");
+	if (node)
+		return node;
+
+	return NULL;
+}
+EXPORT_SYMBOL(of_graph_get_top_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 80ced0c..23b1c6e 100644
--- a/include/linux/of_graph.h
+++ b/include/linux/of_graph.h
@@ -14,6 +14,7 @@
 #ifndef __LINUX_OF_GRAPH_H
 #define __LINUX_OF_GRAPH_H
 
+#include <linux/device.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 
@@ -44,6 +45,7 @@ struct of_endpoint {
 int of_graph_parse_endpoint(const struct device_node *node,
 				struct of_endpoint *endpoint);
 struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id);
+struct device_node *of_graph_get_top_port(struct device *dev);
 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(
@@ -68,6 +70,11 @@ static inline struct device_node *of_graph_get_port_by_id(
 	return NULL;
 }
 
+static inline struct device_node *of_graph_get_top_port(struct device *dev)
+{
+	return NULL;
+}
+
 static inline struct device_node *of_graph_get_next_endpoint(
 					const struct device_node *parent,
 					struct device_node *previous)
-- 
1.9.1