tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#include <linux/string.h>
2#include <linux/err.h>
3#include <linux/slab.h>
4#include <linux/of.h>
5
6#include "of_helpers.h"
7
8/**
9 * pseries_of_derive_parent - basically like dirname(1)
10 * @path: the full_name of a node to be added to the tree
11 *
12 * Returns the node which should be the parent of the node
13 * described by path. E.g., for path = "/foo/bar", returns
14 * the node with full_name = "/foo".
15 */
16struct device_node *pseries_of_derive_parent(const char *path)
17{
18 struct device_node *parent;
19 char *parent_path = "/";
20 const char *tail;
21
22 /* We do not want the trailing '/' character */
23 tail = kbasename(path) - 1;
24
25 /* reject if path is "/" */
26 if (!strcmp(path, "/"))
27 return ERR_PTR(-EINVAL);
28
29 if (tail > path) {
30 parent_path = kstrndup(path, tail - path, GFP_KERNEL);
31 if (!parent_path)
32 return ERR_PTR(-ENOMEM);
33 }
34 parent = of_find_node_by_path(parent_path);
35 if (strcmp(parent_path, "/"))
36 kfree(parent_path);
37 return parent ? parent : ERR_PTR(-EINVAL);
38}