https://github.com/torvalds/linux
Tip revision: 9e98c678c2d6ae3a17cb2de55d17f69dddaa231b authored by Linus Torvalds on 17 March 2019, 21:22:26 UTC
Linux 5.1-rc1
Linux 5.1-rc1
Tip revision: 9e98c67
of.c
// SPDX-License-Identifier: GPL-2.0
/*
* of.c The helpers for hcd device tree support
*
* Copyright (C) 2016 Freescale Semiconductor, Inc.
* Author: Peter Chen <peter.chen@freescale.com>
* Copyright (C) 2017 Johan Hovold <johan@kernel.org>
*/
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/usb/of.h>
/**
* usb_of_get_device_node() - get a USB device node
* @hub: hub to which device is connected
* @port1: one-based index of port
*
* Look up the node of a USB device given its parent hub device and one-based
* port number.
*
* Return: A pointer to the node with incremented refcount if found, or
* %NULL otherwise.
*/
struct device_node *usb_of_get_device_node(struct usb_device *hub, int port1)
{
struct device_node *node;
u32 reg;
for_each_child_of_node(hub->dev.of_node, node) {
if (of_property_read_u32(node, "reg", ®))
continue;
if (reg == port1)
return node;
}
return NULL;
}
EXPORT_SYMBOL_GPL(usb_of_get_device_node);
/**
* usb_of_has_combined_node() - determine whether a device has a combined node
* @udev: USB device
*
* Determine whether a USB device has a so called combined node which is
* shared with its sole interface. This is the case if and only if the device
* has a node and its decriptors report the following:
*
* 1) bDeviceClass is 0 or 9, and
* 2) bNumConfigurations is 1, and
* 3) bNumInterfaces is 1.
*
* Return: True iff the device has a device node and its descriptors match the
* criteria for a combined node.
*/
bool usb_of_has_combined_node(struct usb_device *udev)
{
struct usb_device_descriptor *ddesc = &udev->descriptor;
struct usb_config_descriptor *cdesc;
if (!udev->dev.of_node)
return false;
switch (ddesc->bDeviceClass) {
case USB_CLASS_PER_INTERFACE:
case USB_CLASS_HUB:
if (ddesc->bNumConfigurations == 1) {
cdesc = &udev->config->desc;
if (cdesc->bNumInterfaces == 1)
return true;
}
}
return false;
}
EXPORT_SYMBOL_GPL(usb_of_has_combined_node);
/**
* usb_of_get_interface_node() - get a USB interface node
* @udev: USB device of interface
* @config: configuration value
* @ifnum: interface number
*
* Look up the node of a USB interface given its USB device, configuration
* value and interface number.
*
* Return: A pointer to the node with incremented refcount if found, or
* %NULL otherwise.
*/
struct device_node *
usb_of_get_interface_node(struct usb_device *udev, u8 config, u8 ifnum)
{
struct device_node *node;
u32 reg[2];
for_each_child_of_node(udev->dev.of_node, node) {
if (of_property_read_u32_array(node, "reg", reg, 2))
continue;
if (reg[0] == ifnum && reg[1] == config)
return node;
}
return NULL;
}
EXPORT_SYMBOL_GPL(usb_of_get_interface_node);