dt: introduce for_each_available_child_of_node, of_get_next_available_child

Macro for_each_child_of_node() makes it easy to iterate over all of the
children for a given device tree node, including those nodes that are
marked as unavailable (i.e. status = "disabled").

Introduce for_each_available_child_of_node(), which is like
for_each_child_of_node(), but it automatically skips unavailable nodes.
This also requires the introduction of helper function
of_get_next_available_child(), which returns the next available child
node.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/of.h b/include/linux/of.h
index 5919ee33f2b7..1b1163225f3b 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -190,10 +190,17 @@ 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_next_available_child(
+        const struct device_node *node, struct device_node *prev);
+
 #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))
 
+#define for_each_available_child_of_node(parent, child) \
+        for (child = of_get_next_available_child(parent, NULL); child != NULL; \
+             child = of_get_next_available_child(parent, child))
+
 static inline int of_get_child_count(const struct device_node *np)
 {
         struct device_node *child;