1/*
 2 * of.c		The helpers for hcd device tree support
 3 *
 4 * Copyright (C) 2016 Freescale Semiconductor, Inc.
 5 * Author: Peter Chen <peter.chen@freescale.com>
 6 *
 7 * This program is free software: you can redistribute it and/or modify
 8 * it under the terms of the GNU General Public License version 2  of
 9 * the License as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/of.h>
21
22/**
23 * usb_of_get_child_node - Find the device node match port number
24 * @parent: the parent device node
25 * @portnum: the port number which device is connecting
26 *
27 * Find the node from device tree according to its port number.
28 *
29 * Return: On success, a pointer to the device node, %NULL on failure.
30 */
31struct device_node *usb_of_get_child_node(struct device_node *parent,
32					int portnum)
33{
34	struct device_node *node;
35	u32 port;
36
37	for_each_child_of_node(parent, node) {
38		if (!of_property_read_u32(node, "reg", &port)) {
39			if (port == portnum)
40				return node;
41		}
42	}
43
44	return NULL;
45}
46EXPORT_SYMBOL_GPL(usb_of_get_child_node);
47