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authorMichael Ellerman <michael@ellerman.id.au>2008-11-12 18:54:42 +0000
committerPaul Mackerras <paulus@samba.org>2008-11-19 16:05:00 +1100
commit1e291b14c8f1101b9093434489bd4dc0e03f3d0f (patch)
treeea602cce082e847d693b021d83f1314e9494c9a9
parentae564c63b8311fa73c21e456e00dba1f4b1ff6bc (diff)
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 <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
-rw-r--r--drivers/of/base.c35
-rw-r--r--include/linux/of.h6
2 files changed, 41 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 7c79e94a35e..4f884a358a7 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -329,6 +329,41 @@ 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
* @node: the of device structure to match against
diff --git a/include/linux/of.h b/include/linux/of.h
index e2488f5e7cb..6a7efa242f5 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);