dt: introduce of_get_child_by_name to get child node by name

This patch introduces of_get_child_by_name function to get a child node
by its name in a given parent node.

Without this patch each driver code has to iterate the parent and do
a string compare, However having of_get_child_by_name libary function would
avoid code duplication, errors and is more convenient.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>

2 files changed, 25 insertions, 0 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index c181b94abc36..e2e813624df5 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -364,6 +364,29 @@ struct device_node *of_get_next_child(const struct device_node *node,
 EXPORT_SYMBOL(of_get_next_child);
 
 /**
+ *      of_get_child_by_name - Find the child node by name for a given parent
+ *      @node:  parent node
+ *      @name:  child name to look for.
+ *
+ *      This function looks for child node for given matching name
+ *
+ *      Returns a node pointer if found, with refcount incremented, use
+ *      of_node_put() on it when done.
+ *      Returns NULL if node is not found.
+ */
+struct device_node *of_get_child_by_name(const struct device_node *node,
+                                const char *name)
+{
+        struct device_node *child;
+
+        for_each_child_of_node(node, child)
+                if (child->name && (of_node_cmp(child->name, name) == 0))
+                        break;
+        return child;
+}
+EXPORT_SYMBOL(of_get_child_by_name);
+
+/**
  *      of_find_node_by_path - Find a node matching a full OF path
  *      @path:  The full path to match
  *
diff --git a/include/linux/of.h b/include/linux/of.h
index 5919ee33f2b7..fabb524d3d75 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -190,6 +190,8 @@ extern struct device_node *of_get_parent(const struct device_node *node);
 extern struct device_node *of_get_next_parent(struct device_node *node);
 extern struct device_node *of_get_next_child(const struct device_node *node,
                                              struct device_node *prev);
+extern struct device_node *of_get_child_by_name(const struct device_node *node,
+                                        const char *name);
 #define for_each_child_of_node(parent, child) \
         for (child = of_get_next_child(parent, NULL); child != NULL; \
              child = of_get_next_child(parent, child))