ofnode: add ofnode_by_prop_value()

Adds ofnode_by_prop_value() to search for nodes with a given property
and value, an ofnode version of fdt_node_offset_by_prop_value().

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/core/of_access.c

@@ -376,6 +376,33 @@ struct device_node *of_find_compatible_node(struct device_node *from,
 	return np;
 }
 
+static int of_device_has_prop_value(const struct device_node *device,
+				    const char *propname, const void *propval,
+				    int proplen)
+{
+	struct property *prop = of_find_property(device, propname, NULL);
+
+	if (!prop || !prop->value || prop->length != proplen)
+		return 0;
+	return !memcmp(prop->value, propval, proplen);
+}
+
+struct device_node *of_find_node_by_prop_value(struct device_node *from,
+					       const char *propname,
+					       const void *propval, int proplen)
+{
+	struct device_node *np;
+
+	for_each_of_allnodes_from(from, np) {
+		if (of_device_has_prop_value(np, propname, propval, proplen) &&
+		    of_node_get(np))
+			break;
+	}
+	of_node_put(from);
+
+	return np;
+}
+
 struct device_node *of_find_node_by_phandle(phandle handle)
 {
 	struct device_node *np;

drivers/core/ofnode.c

@@ -777,3 +777,17 @@ ofnode ofnode_by_compatible(ofnode from, const char *compat)
 				gd->fdt_blob, ofnode_to_offset(from), compat));
 	}
 }
+
+ofnode ofnode_by_prop_value(ofnode from, const char *propname,
+			    const void *propval, int proplen)
+{
+	if (of_live_active()) {
+		return np_to_ofnode(of_find_node_by_prop_value(
+			(struct device_node *)ofnode_to_np(from), propname,
+			propval, proplen));
+	} else {
+		return offset_to_ofnode(fdt_node_offset_by_prop_value(
+				gd->fdt_blob, ofnode_to_offset(from),
+				propname, propval, proplen));
+	}
+}

include/dm/of_access.h

@@ -194,6 +194,22 @@ struct device_node *of_find_compatible_node(struct device_node *from,
 				const char *type, const char *compatible);
 
 /**
+ * of_find_node_by_prop_value() - find a node with a given property value
+ *
+ * Find a node based on a property value.
+ * @from: 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.
+ * @propname: property name to check
+ * @propval: property value to search for
+ * @proplen: length of the value in propval
+ * @return node pointer or NULL if not found
+ */
+struct device_node *of_find_node_by_prop_value(struct device_node *from,
+					       const char *propname,
+					       const void *propval,
+					       int proplen);
+/**
  * of_find_node_by_phandle() - Find a node given a phandle
  *
  * @handle:	phandle of the node to find

include/dm/ofnode.h

@@ -703,6 +703,20 @@ int ofnode_read_resource_byname(ofnode node, const char *name,
 ofnode ofnode_by_compatible(ofnode from, const char *compat);
 
 /**
+ * ofnode_by_prop_value() - Find the next node with given property value
+ *
+ * Find the next node after @from that has a @propname with a value
+ * @propval and a length @proplen.
+ *
+ * @from: ofnode to start from (use ofnode_null() to start at the
+ * beginning) @propname: property name to check @propval: property value to
+ * search for @proplen: length of the value in propval @return ofnode
+ * found, or ofnode_null() if none
+ */
+ofnode ofnode_by_prop_value(ofnode from, const char *propname,
+			    const void *propval, int proplen);
+
+/**
  * ofnode_for_each_subnode() - iterate over all subnodes of a parent
  *
  * @node:       child node (ofnode, lvalue)