dm: core: Add functions for iterating through device children

Buses need to iterate through their children in some situations. Add a few
functions to make this easy.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/core/device.c b/drivers/core/device.c
index 32e80e8..9538874 100644
--- a/drivers/core/device.c
+++ b/drivers/core/device.c
@@ -514,3 +514,30 @@ int device_get_child_by_of_offset(struct udevice *parent, int seq,
 	ret = device_find_child_by_of_offset(parent, seq, &dev);
 	return device_get_device_tail(dev, ret, devp);
 }
+
+int device_find_first_child(struct udevice *parent, struct udevice **devp)
+{
+	if (list_empty(&parent->child_head)) {
+		*devp = NULL;
+	} else {
+		*devp = list_first_entry(&parent->child_head, struct udevice,
+					 sibling_node);
+	}
+
+	return 0;
+}
+
+int device_find_next_child(struct udevice **devp)
+{
+	struct udevice *dev = *devp;
+	struct udevice *parent = dev->parent;
+
+	if (list_is_last(&dev->sibling_node, &parent->child_head)) {
+		*devp = NULL;
+	} else {
+		*devp = list_entry(dev->sibling_node.next, struct udevice,
+				   sibling_node);
+	}
+
+	return 0;
+}