linux_dsm_epyc7002/drivers/usb/core/usb-acpi.c
Matthew Garrett da0af6e78e usb: Bind devices to ACPI devices when possible
Built-in USB devices will typically have a representation in the system
ACPI tables. Add support for binding the two together so the USB code can
make use of the associated methods.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-11 17:06:13 -07:00

61 lines
1.2 KiB
C

/*
* USB-ACPI glue code
*
* Copyright 2012 Red Hat <mjg@redhat.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation, version 2.
*
*/
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/acpi.h>
#include <linux/pci.h>
#include <acpi/acpi_bus.h>
#include "usb.h"
static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
{
struct usb_device *udev;
struct device *parent;
acpi_handle *parent_handle;
if (!is_usb_device(dev))
return -ENODEV;
udev = to_usb_device(dev);
parent = dev->parent;
parent_handle = DEVICE_ACPI_HANDLE(parent);
if (!parent_handle)
return -ENODEV;
*handle = acpi_get_child(parent_handle, udev->portnum);
if (!*handle)
return -ENODEV;
return 0;
}
static struct acpi_bus_type usb_acpi_bus = {
.bus = &usb_bus_type,
.find_bridge = NULL,
.find_device = usb_acpi_find_device,
};
int usb_acpi_register(void)
{
return register_acpi_bus_type(&usb_acpi_bus);
}
void usb_acpi_unregister(void)
{
unregister_acpi_bus_type(&usb_acpi_bus);
}