diff options
author | Michael Ellerman <michael@ellerman.id.au> | 2007-10-26 16:54:31 +1000 |
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committer | Paul Mackerras <paulus@samba.org> | 2008-02-06 16:29:59 +1100 |
commit | f4eb010706b6c96c136c7aaa9079159743f33fa8 (patch) | |
tree | 53be8d89ad0073f90b2975e780c0426249ee3f3e /drivers/of | |
parent | 58119068cb27ef7513f80aff44b62a3a8f40ef5f (diff) | |
download | kernel_samsung_espresso10-f4eb010706b6c96c136c7aaa9079159743f33fa8.zip kernel_samsung_espresso10-f4eb010706b6c96c136c7aaa9079159743f33fa8.tar.gz kernel_samsung_espresso10-f4eb010706b6c96c136c7aaa9079159743f33fa8.tar.bz2 |
[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);
of_node_put(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: Michael Ellerman <michael@ellerman.id.au>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'drivers/of')
-rw-r--r-- | drivers/of/base.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index b306fef..80c9dec 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -138,6 +138,31 @@ struct device_node *of_get_parent(const struct device_node *node) EXPORT_SYMBOL(of_get_parent); /** + * 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; + + read_lock(&devtree_lock); + parent = of_node_get(node->parent); + of_node_put(node); + read_unlock(&devtree_lock); + return parent; +} + +/** * of_get_next_child - Iterate a node childs * @node: parent node * @prev: previous child of the parent node, or NULL to get first |