diff options
| -rw-r--r-- | drivers/of/base.c | 67 |
1 files changed, 61 insertions, 6 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 9df50c74162c..e67b308819c9 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -783,23 +783,78 @@ struct device_node *of_get_child_by_name(const struct device_node *node, } EXPORT_SYMBOL(of_get_child_by_name); +static struct device_node *__of_find_node_by_path(struct device_node *parent, + const char *path) +{ + struct device_node *child; + int len = strchrnul(path, '/') - path; + + if (!len) + return NULL; + + __for_each_child_of_node(parent, child) { + const char *name = strrchr(child->full_name, '/'); + if (WARN(!name, "malformed device_node %s\n", child->full_name)) + continue; + name++; + if (strncmp(path, name, len) == 0 && (strlen(name) == len)) + return child; + } + return NULL; +} + /** * of_find_node_by_path - Find a node matching a full OF path - * @path: The full path to match + * @path: Either the full path to match, or if the path does not + * start with '/', the name of a property of the /aliases + * node (an alias). In the case of an alias, the node + * matching the alias' value will be returned. + * + * Valid paths: + * /foo/bar Full path + * foo Valid alias + * foo/bar Valid alias + relative path * * Returns a node pointer with refcount incremented, use * of_node_put() on it when done. */ struct device_node *of_find_node_by_path(const char *path) { - struct device_node *np = of_allnodes; + struct device_node *np = NULL; + struct property *pp; unsigned long flags; + if (strcmp(path, "/") == 0) + return of_node_get(of_allnodes); + + /* The path could begin with an alias */ + if (*path != '/') { + char *p = strchrnul(path, '/'); + int len = p - path; + + /* of_aliases must not be NULL */ + if (!of_aliases) + return NULL; + + for_each_property_of_node(of_aliases, pp) { + if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) { + np = of_find_node_by_path(pp->value); + break; + } + } + if (!np) + return NULL; + path = p; + } + + /* Step down the tree matching path components */ raw_spin_lock_irqsave(&devtree_lock, flags); - for (; np; np = np->allnext) { - if (np->full_name && (of_node_cmp(np->full_name, path) == 0) - && of_node_get(np)) - break; + if (!np) + np = of_node_get(of_allnodes); + while (np && *path == '/') { + path++; /* Increment past '/' delimiter */ + np = __of_find_node_by_path(np, path); + path = strchrnul(path, '/'); } raw_spin_unlock_irqrestore(&devtree_lock, flags); return np; |