Linux kernel mirror (for testing)
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * of.c The helpers for hcd device tree support
4 *
5 * Copyright (C) 2016 Freescale Semiconductor, Inc.
6 * Author: Peter Chen <peter.chen@freescale.com>
7 */
8
9#include <linux/of.h>
10#include <linux/of_platform.h>
11#include <linux/usb/of.h>
12
13/**
14 * usb_of_get_child_node - Find the device node match port number
15 * @parent: the parent device node
16 * @portnum: the port number which device is connecting
17 *
18 * Find the node from device tree according to its port number.
19 *
20 * Return: A pointer to the node with incremented refcount if found, or
21 * %NULL otherwise.
22 */
23struct device_node *usb_of_get_child_node(struct device_node *parent,
24 int portnum)
25{
26 struct device_node *node;
27 u32 port;
28
29 for_each_child_of_node(parent, node) {
30 if (!of_property_read_u32(node, "reg", &port)) {
31 if (port == portnum)
32 return node;
33 }
34 }
35
36 return NULL;
37}
38EXPORT_SYMBOL_GPL(usb_of_get_child_node);
39
40/**
41 * usb_of_get_companion_dev - Find the companion device
42 * @dev: the device pointer to find a companion
43 *
44 * Find the companion device from platform bus.
45 *
46 * Takes a reference to the returned struct device which needs to be dropped
47 * after use.
48 *
49 * Return: On success, a pointer to the companion device, %NULL on failure.
50 */
51struct device *usb_of_get_companion_dev(struct device *dev)
52{
53 struct device_node *node;
54 struct platform_device *pdev = NULL;
55
56 node = of_parse_phandle(dev->of_node, "companion", 0);
57 if (node)
58 pdev = of_find_device_by_node(node);
59
60 of_node_put(node);
61
62 return pdev ? &pdev->dev : NULL;
63}
64EXPORT_SYMBOL_GPL(usb_of_get_companion_dev);