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#include <linux/usb/of.h>
22
23/**
24 * usb_of_get_child_node - Find the device node match port number
25 * @parent: the parent device node
26 * @portnum: the port number which device is connecting
27 *
28 * Find the node from device tree according to its port number.
29 *
30 * Return: On success, a pointer to the device node, %NULL on failure.
31 */
32struct device_node *usb_of_get_child_node(struct device_node *parent,
33					int portnum)
34{
35	struct device_node *node;
36	u32 port;
37
38	for_each_child_of_node(parent, node) {
39		if (!of_property_read_u32(node, "reg", &port)) {
40			if (port == portnum)
41				return node;
42		}
43	}
44
45	return NULL;
46}
47EXPORT_SYMBOL_GPL(usb_of_get_child_node);
48