WSL2-Linux-Kernel/drivers/usb/core/of.c

49 строки
1.4 KiB
C

/*
* of.c The helpers for hcd device tree support
*
* Copyright (C) 2016 Freescale Semiconductor, Inc.
* Author: Peter Chen <peter.chen@freescale.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 of
* the License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/of.h>
#include <linux/usb/of.h>
/**
* usb_of_get_child_node - Find the device node match port number
* @parent: the parent device node
* @portnum: the port number which device is connecting
*
* Find the node from device tree according to its port number.
*
* Return: On success, a pointer to the device node, %NULL on failure.
*/
struct device_node *usb_of_get_child_node(struct device_node *parent,
int portnum)
{
struct device_node *node;
u32 port;
for_each_child_of_node(parent, node) {
if (!of_property_read_u32(node, "reg", &port)) {
if (port == portnum)
return node;
}
}
return NULL;
}
EXPORT_SYMBOL_GPL(usb_of_get_child_node);