From 1e291b14c8f1101b9093434489bd4dc0e03f3d0f Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Wed, 12 Nov 2008 18:54:42 +0000 Subject: [PATCH] of: Add helpers for finding device nodes which have a given property This commit adds a routine for finding a device node which has a certain property. The contents of the property are not taken into account, merely the presence or absence of the property. Based on that routine, we add a for_each_ macro for iterating over all nodes that have a certain property. Signed-off-by: Michael Ellerman Signed-off-by: Paul Mackerras --- drivers/of/base.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/of.h | 6 ++++++ 2 files changed, 41 insertions(+) diff --git a/drivers/of/base.c b/drivers/of/base.c index 7c79e94a35ea..4f884a358a7b 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -328,6 +328,41 @@ struct device_node *of_find_compatible_node(struct device_node *from, } EXPORT_SYMBOL(of_find_compatible_node); +/** + * of_find_node_with_property - Find a node which has a property with + * the given name. + * @from: The node to start searching from or NULL, the node + * you pass will not be searched, only the next one + * will; typically, you pass what the previous call + * returned. of_node_put() will be called on it + * @prop_name: The name of the property to look for. + * + * Returns a node pointer with refcount incremented, use + * of_node_put() on it when done. + */ +struct device_node *of_find_node_with_property(struct device_node *from, + const char *prop_name) +{ + struct device_node *np; + struct property *pp; + + read_lock(&devtree_lock); + np = from ? from->allnext : allnodes; + for (; np; np = np->allnext) { + for (pp = np->properties; pp != 0; pp = pp->next) { + if (of_prop_cmp(pp->name, prop_name) == 0) { + of_node_get(np); + goto out; + } + } + } +out: + of_node_put(from); + read_unlock(&devtree_lock); + return np; +} +EXPORT_SYMBOL(of_find_node_with_property); + /** * of_match_node - Tell if an device_node has a matching of_match structure * @matches: array of of device match structures to search in diff --git a/include/linux/of.h b/include/linux/of.h index e2488f5e7cb2..6a7efa242f5e 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -57,6 +57,12 @@ extern struct device_node *of_get_next_child(const struct device_node *node, for (child = of_get_next_child(parent, NULL); child != NULL; \ child = of_get_next_child(parent, child)) +extern struct device_node *of_find_node_with_property( + struct device_node *from, const char *prop_name); +#define for_each_node_with_property(dn, prop_name) \ + for (dn = of_find_node_with_property(NULL, prop_name); dn; \ + dn = of_find_node_with_property(dn, prop_name)) + extern struct property *of_find_property(const struct device_node *np, const char *name, int *lenp); -- 2.20.1