Commit f4eb0107 authored by Michael Ellerman's avatar Michael Ellerman Committed by Paul Mackerras
Browse files

[POWERPC] Add of_get_next_parent()

Iterating through a device node's parents is simple enough, but dealing
with the refcounts properly is a little ugly, and replicating that logic
is asking for someone to get it wrong or forget it all together, eg:

while (dn != NULL) {
	/* loop body */
	tmp = of_get_parent(dn);
	dn = tmp;

So add of_get_next_parent(), inspired by of_get_next_child().  The
contract is that it returns the parent and drops the reference on the
current node, this makes the loop look like:

while (dn != NULL) {
	/* loop body */
	dn = of_get_next_parent(dn);
Signed-off-by: default avatarMichael Ellerman <>
Acked-by: default avatarDavid S. Miller <>
Signed-off-by: default avatarPaul Mackerras <>
parent 58119068
......@@ -137,6 +137,31 @@ struct device_node *of_get_parent(const struct device_node *node)
* of_get_next_parent - Iterate to a node's parent
* @node: Node to get parent of
* This is like of_get_parent() except that it drops the
* refcount on the passed node, making it suitable for iterating
* through a node's parents.
* Returns a node pointer with refcount incremented, use
* of_node_put() on it when done.
struct device_node *of_get_next_parent(struct device_node *node)
struct device_node *parent;
if (!node)
return NULL;
parent = of_node_get(node->parent);
return parent;
* of_get_next_child - Iterate a node childs
* @node: parent node
......@@ -50,6 +50,7 @@ extern struct device_node *of_find_matching_node(struct device_node *from,
extern struct device_node *of_find_node_by_path(const char *path);
extern struct device_node *of_find_node_by_phandle(phandle handle);
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);
#define for_each_child_of_node(parent, child) \
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment