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/of_platform.h> 22 #include <linux/usb/of.h> 23 24 /** 25 * usb_of_get_child_node - Find the device node match port number 26 * @parent: the parent device node 27 * @portnum: the port number which device is connecting 28 * 29 * Find the node from device tree according to its port number. 30 * 31 * Return: On success, a pointer to the device node, %NULL on failure. 32 */ 33 struct device_node *usb_of_get_child_node(struct device_node *parent, 34 int portnum) 35 { 36 struct device_node *node; 37 u32 port; 38 39 for_each_child_of_node(parent, node) { 40 if (!of_property_read_u32(node, "reg", &port)) { 41 if (port == portnum) 42 return node; 43 } 44 } 45 46 return NULL; 47 } 48 EXPORT_SYMBOL_GPL(usb_of_get_child_node); 49 50 /** 51 * usb_of_get_companion_dev - Find the companion device 52 * @dev: the device pointer to find a companion 53 * 54 * Find the companion device from platform bus. 55 * 56 * Takes a reference to the returned struct device which needs to be dropped 57 * after use. 58 * 59 * Return: On success, a pointer to the companion device, %NULL on failure. 60 */ 61 struct device *usb_of_get_companion_dev(struct device *dev) 62 { 63 struct device_node *node; 64 struct platform_device *pdev = NULL; 65 66 node = of_parse_phandle(dev->of_node, "companion", 0); 67 if (node) 68 pdev = of_find_device_by_node(node); 69 70 of_node_put(node); 71 72 return pdev ? &pdev->dev : NULL; 73 } 74 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev); 75