[POWERPC] Add of_find_matching_node() helper function

Similar to of_find_compatible_node(), of_find_matching_node() and
for_each_matching_node() allow you to iterate over the device tree
looking for specific nodes, except that they take of_device_id
tables instead of strings.

This also moves of_match_node() from driver/of/device.c to
driver/of/base.c to colocate it with the of_find_matching_node which
depends on it.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 58 insertions, 0 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 9377f3bc410a..b306fef1ac41 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -273,3 +273,61 @@ struct device_node *of_find_compatible_node(struct device_node *from,
         return np;
 }
 EXPORT_SYMBOL(of_find_compatible_node);
+
+/**
+ * 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
+ *
+ *      Low level utility function used by device matching.
+ */
+const struct of_device_id *of_match_node(const struct of_device_id *matches,
+                                         const struct device_node *node)
+{
+        while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
+                int match = 1;
+                if (matches->name[0])
+                        match &= node->name
+                                && !strcmp(matches->name, node->name);
+                if (matches->type[0])
+                        match &= node->type
+                                && !strcmp(matches->type, node->type);
+                if (matches->compatible[0])
+                        match &= of_device_is_compatible(node,
+                                                matches->compatible);
+                if (match)
+                        return matches;
+                matches++;
+        }
+        return NULL;
+}
+EXPORT_SYMBOL(of_match_node);
+
+/**
+ *      of_find_matching_node - Find a node based on an of_device_id match
+ *                              table.
+ *      @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
+ *      @matches:       array of of device match structures to search in
+ *
+ *      Returns a node pointer with refcount incremented, use
+ *      of_node_put() on it when done.
+ */
+struct device_node *of_find_matching_node(struct device_node *from,
+                                          const struct of_device_id *matches)
+{
+        struct device_node *np;
+
+        read_lock(&devtree_lock);
+        np = from ? from->allnext : allnodes;
+        for (; np; np = np->allnext) {
+                if (of_match_node(matches, np) && of_node_get(np))
+                        break;
+        }
+        of_node_put(from);
+        read_unlock(&devtree_lock);
+        return np;
+}
+EXPORT_SYMBOL(of_find_matching_node);