cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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of.c (2741B)

      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 * Copyright (C) 2017 Johan Hovold <johan@kernel.org>
      8 */
      9
     10#include <linux/of.h>
     11#include <linux/of_platform.h>
     12#include <linux/usb/of.h>
     13
     14/**
     15 * usb_of_get_device_node() - get a USB device node
     16 * @hub: hub to which device is connected
     17 * @port1: one-based index of port
     18 *
     19 * Look up the node of a USB device given its parent hub device and one-based
     20 * port number.
     21 *
     22 * Return: A pointer to the node with incremented refcount if found, or
     23 * %NULL otherwise.
     24 */
     25struct device_node *usb_of_get_device_node(struct usb_device *hub, int port1)
     26{
     27	struct device_node *node;
     28	u32 reg;
     29
     30	for_each_child_of_node(hub->dev.of_node, node) {
     31		if (of_property_read_u32(node, "reg", &reg))
     32			continue;
     33
     34		if (reg == port1)
     35			return node;
     36	}
     37
     38	return NULL;
     39}
     40EXPORT_SYMBOL_GPL(usb_of_get_device_node);
     41
     42/**
     43 * usb_of_has_combined_node() - determine whether a device has a combined node
     44 * @udev: USB device
     45 *
     46 * Determine whether a USB device has a so called combined node which is
     47 * shared with its sole interface. This is the case if and only if the device
     48 * has a node and its descriptors report the following:
     49 *
     50 *	1) bDeviceClass is 0 or 9, and
     51 *	2) bNumConfigurations is 1, and
     52 *	3) bNumInterfaces is 1.
     53 *
     54 * Return: True iff the device has a device node and its descriptors match the
     55 * criteria for a combined node.
     56 */
     57bool usb_of_has_combined_node(struct usb_device *udev)
     58{
     59	struct usb_device_descriptor *ddesc = &udev->descriptor;
     60	struct usb_config_descriptor *cdesc;
     61
     62	if (!udev->dev.of_node)
     63		return false;
     64
     65	switch (ddesc->bDeviceClass) {
     66	case USB_CLASS_PER_INTERFACE:
     67	case USB_CLASS_HUB:
     68		if (ddesc->bNumConfigurations == 1) {
     69			cdesc = &udev->config->desc;
     70			if (cdesc->bNumInterfaces == 1)
     71				return true;
     72		}
     73	}
     74
     75	return false;
     76}
     77EXPORT_SYMBOL_GPL(usb_of_has_combined_node);
     78
     79/**
     80 * usb_of_get_interface_node() - get a USB interface node
     81 * @udev: USB device of interface
     82 * @config: configuration value
     83 * @ifnum: interface number
     84 *
     85 * Look up the node of a USB interface given its USB device, configuration
     86 * value and interface number.
     87 *
     88 * Return: A pointer to the node with incremented refcount if found, or
     89 * %NULL otherwise.
     90 */
     91struct device_node *
     92usb_of_get_interface_node(struct usb_device *udev, u8 config, u8 ifnum)
     93{
     94	struct device_node *node;
     95	u32 reg[2];
     96
     97	for_each_child_of_node(udev->dev.of_node, node) {
     98		if (of_property_read_u32_array(node, "reg", reg, 2))
     99			continue;
    100
    101		if (reg[0] == ifnum && reg[1] == config)
    102			return node;
    103	}
    104
    105	return NULL;
    106}
    107EXPORT_SYMBOL_GPL(usb_of_get_interface_node);