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: A pointer to the node with incremented refcount if found, or 32 * %NULL otherwise. 33 */ 34 struct device_node *usb_of_get_child_node(struct device_node *parent, 35 int portnum) 36 { 37 struct device_node *node; 38 u32 port; 39 40 for_each_child_of_node(parent, node) { 41 if (!of_property_read_u32(node, "reg", &port)) { 42 if (port == portnum) 43 return node; 44 } 45 } 46 47 return NULL; 48 } 49 EXPORT_SYMBOL_GPL(usb_of_get_child_node); 50 51 /** 52 * usb_of_get_companion_dev - Find the companion device 53 * @dev: the device pointer to find a companion 54 * 55 * Find the companion device from platform bus. 56 * 57 * Takes a reference to the returned struct device which needs to be dropped 58 * after use. 59 * 60 * Return: On success, a pointer to the companion device, %NULL on failure. 61 */ 62 struct device *usb_of_get_companion_dev(struct device *dev) 63 { 64 struct device_node *node; 65 struct platform_device *pdev = NULL; 66 67 node = of_parse_phandle(dev->of_node, "companion", 0); 68 if (node) 69 pdev = of_find_device_by_node(node); 70 71 of_node_put(node); 72 73 return pdev ? &pdev->dev : NULL; 74 } 75 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev); 76