[PATCH v2 5/8] of: Add of_graph_get_port_by_id function

Philipp Zabel
2014-09-10T10:58:42Z

This patch adds a function to get a port device tree node by port id,
or reg property value.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
Changes since v1:
- Fixed whitespace in comment
- Changed id parameter to of_graph_get_port_by_id to u32
- Simplified of_graph_get_port_by_id as suggested by Laurent,
making use of port id defaulting to 0 if no "reg" property is given.
---
drivers/of/base.c | 26 ++++++++++++++++++++++++++
include/linux/of_graph.h | 7 +++++++
2 files changed, 33 insertions(+)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index a49b5628..b282474 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2053,6 +2053,32 @@ int of_graph_parse_endpoint(const struct device_node *node,
EXPORT_SYMBOL(of_graph_parse_endpoint);

/**
+ * of_graph_get_port_by_id() - get the port matching a given id
+ * @parent: pointer to the parent device node
+ * @id: id of the port
+ *
+ * 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_port_by_id(struct device_node *node, u32 id)
+{
+ struct device_node *port = NULL;
+ u32 port_id = 0;
+
+ while (true) {
+ port = of_get_next_child(node, port);
+ if (!port)
+ return NULL;
+ if (of_node_cmp(port->name, "port") != 0)
+ continue;
+ of_property_read_u32(port, "reg", &port_id);
+ if (id == port_id)
+ return port;
+ }
+}
+EXPORT_SYMBOL(of_graph_get_port_by_id);
+
+/**
* 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 e43442e..e028e49 100644
--- a/include/linux/of_graph.h
+++ b/include/linux/of_graph.h
@@ -40,6 +40,7 @@ struct of_endpoint {
#ifdef CONFIG_OF
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_next_endpoint(const struct device_node *parent,
struct device_node *previous);
struct device_node *of_graph_get_remote_port_parent(
@@ -53,6 +54,12 @@ static inline int of_graph_parse_endpoint(const struct device_node *node,
return -ENOSYS;
}

+static inline struct device_node *of_graph_get_port_by_id(
+ struct device_node *node, int id)
+{
+ return NULL;
+}
+
static inline struct device_node *of_graph_get_next_endpoint(
const struct device_node *parent,
struct device_node *previous)
--
2.1.0