dm: core: Add device children and sibling functions

Add some utility functions to check for children and for the last sibling in
a device's parent.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Marek Vasut <marex@denx.de>

drivers/core/device.c

@@ -490,3 +490,31 @@ fdt_addr_t dev_get_addr(struct udevice *dev)
 	return FDT_ADDR_T_NONE;
 }
 #endif
+
+bool device_has_children(struct udevice *dev)
+{
+	return !list_empty(&dev->child_head);
+}
+
+bool device_has_active_children(struct udevice *dev)
+{
+	struct udevice *child;
+
+	for (device_find_first_child(dev, &child);
+	     child;
+	     device_find_next_child(&child)) {
+		if (device_active(child))
+			return true;
+	}
+
+	return false;
+}
+
+bool device_is_last_sibling(struct udevice *dev)
+{
+	struct udevice *parent = dev->parent;
+
+	if (!parent)
+		return false;
+	return list_is_last(&dev->sibling_node, &parent->child_head);
+}

include/dm/device.h

@@ -380,4 +380,34 @@ int device_find_next_child(struct udevice **devp);
  */
 fdt_addr_t dev_get_addr(struct udevice *dev);
 
+/**
+ * device_has_children() - check if a device has any children
+ *
+ * @dev:	Device to check
+ * @return true if the device has one or more children
+ */
+bool device_has_children(struct udevice *dev);
+
+/**
+ * device_has_active_children() - check if a device has any active children
+ *
+ * @dev:	Device to check
+ * @return true if the device has one or more children and at least one of
+ * them is active (probed).
+ */
+bool device_has_active_children(struct udevice *dev);
+
+/**
+ * device_is_last_sibling() - check if a device is the last sibling
+ *
+ * This function can be useful for display purposes, when special action needs
+ * to be taken when displaying the last sibling. This can happen when a tree
+ * view of devices is being displayed.
+ *
+ * @dev:	Device to check
+ * @return true if there are no more siblings after this one - i.e. is it
+ * last in the list.
+ */
+bool device_is_last_sibling(struct udevice *dev);
+
 #endif