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 */ 32 struct 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 } 47 EXPORT_SYMBOL_GPL(usb_of_get_child_node); 48 49