drivers/usb/core/of.c

   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  * Return: On success, a pointer to the companion device, %NULL on failure.
  57  */
  58 struct device *usb_of_get_companion_dev(struct device *dev)
  59 {
  60         struct device_node *node;
  61         struct platform_device *pdev = NULL;
  62
  63         node = of_parse_phandle(dev->of_node, "companion", 0);
  64         if (node)
  65                 pdev = of_find_device_by_node(node);
  66
  67         of_node_put(node);
  68
  69         return pdev ? &pdev->dev : NULL;
  70 }
  71 EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);