dm: core: Add ofnode_for_each_subnode()

Add a convenience macro to iterate over subnodes of a node. Make use of
this where appropriate in the code.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/arm/mach-tegra/xusb-padctl-common.c

@@ -224,9 +224,7 @@ tegra_xusb_padctl_config_parse_dt(struct tegra_xusb_padctl *padctl,
 
 	config->name = ofnode_get_name(node);
 
-	for (subnode = ofnode_first_subnode(node);
-	     ofnode_valid(subnode);
-	     subnode = ofnode_next_subnode(subnode)) {
+	ofnode_for_each_subnode(subnode, node) {
 		struct tegra_xusb_padctl_group *group;
 		int err;
 
@@ -256,9 +254,7 @@ static int tegra_xusb_padctl_parse_dt(struct tegra_xusb_padctl *padctl,
 		return err;
 	}
 
-	for (subnode = ofnode_first_subnode(node);
-	     ofnode_valid(subnode);
-	     subnode = ofnode_next_subnode(subnode)) {
+	ofnode_for_each_subnode(subnode, node) {
 		struct tegra_xusb_padctl_config *config = &padctl->config;
 
 		debug("%s: subnode=%s\n", __func__, ofnode_get_name(subnode));

drivers/core/ofnode.c

@@ -390,10 +390,11 @@ int ofnode_decode_display_timing(ofnode parent, int index,
 	if (!ofnode_valid(timings))
 		return -EINVAL;
 
-	for (i = 0, node = ofnode_first_subnode(timings);
-	     ofnode_valid(node) && i != index;
-	     node = ofnode_first_subnode(node))
-		i++;
+	i = 0;
+	ofnode_for_each_subnode(node, timings) {
+		if (i++ == index)
+			break;
+	}
 
 	if (!ofnode_valid(node))
 		return -EINVAL;

drivers/misc/cros_ec.c

@@ -1038,8 +1038,7 @@ int cros_ec_decode_ec_flash(struct udevice *dev, struct fdt_cros_ec *config)
 
 	config->flash_erase_value = ofnode_read_s32_default(flash_node,
 							    "erase-value", -1);
-	for (node = ofnode_first_subnode(flash_node); ofnode_valid(node);
-	     node = ofnode_next_subnode(node)) {
+	ofnode_for_each_subnode(node, flash_node) {
 		const char *name = ofnode_get_name(node);
 		enum ec_flash_region region;
 

drivers/power/pmic/pmic-uclass.c

@@ -34,9 +34,7 @@ int pmic_bind_children(struct udevice *pmic, ofnode parent,
 	debug("%s for '%s' at node offset: %d\n", __func__, pmic->name,
 	      dev_of_offset(pmic));
 
-	for (node = ofnode_first_subnode(parent);
-	     ofnode_valid(node);
-	     node = ofnode_next_subnode(node)) {
+	ofnode_for_each_subnode(node, parent) {
 		node_name = ofnode_get_name(node);
 
 		debug("* Found child node: '%s'\n", node_name);

include/dm/ofnode.h

@@ -628,4 +628,28 @@ int ofnode_read_resource(ofnode node, uint index, struct resource *res);
 int ofnode_read_resource_byname(ofnode node, const char *name,
 				struct resource *res);
 
+/**
+ * ofnode_for_each_subnode() - iterate over all subnodes of a parent
+ *
+ * @node:       child node (ofnode, lvalue)
+ * @parent:     parent node (ofnode)
+ *
+ * This is a wrapper around a for loop and is used like so:
+ *
+ *	ofnode node;
+ *
+ *	ofnode_for_each_subnode(node, parent) {
+ *		Use node
+ *		...
+ *	}
+ *
+ * Note that this is implemented as a macro and @node is used as
+ * iterator in the loop. The parent variable can be a constant or even a
+ * literal.
+ */
+#define ofnode_for_each_subnode(node, parent) \
+	for (node = ofnode_first_subnode(parent); \
+	     ofnode_valid(node); \
+	     node = ofnode_next_subnode(node))
+
 #endif