drivers/usb/core/usb-acpi.c

   1 /*
   2  * USB-ACPI glue code
   3  *
   4  * Copyright 2012 Red Hat <mjg@redhat.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation, version 2.
   9  *
  10  */
  11 #include <linux/module.h>
  12 #include <linux/usb.h>
  13 #include <linux/device.h>
  14 #include <linux/errno.h>
  15 #include <linux/kernel.h>
  16 #include <linux/acpi.h>
  17 #include <linux/pci.h>
  18 #include <acpi/acpi_bus.h>
  19
  20 #include "usb.h"
  21
  22 static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
  23 {
  24         struct usb_device *udev;
  25         struct device *parent;
  26         acpi_handle *parent_handle;
  27
  28         if (!is_usb_device(dev))
  29                 return -ENODEV;
  30
  31         udev = to_usb_device(dev);
  32         parent = dev->parent;
  33         parent_handle = DEVICE_ACPI_HANDLE(parent);
  34
  35         if (!parent_handle)
  36                 return -ENODEV;
  37
  38         *handle = acpi_get_child(parent_handle, udev->portnum);
  39
  40         if (!*handle)
  41                 return -ENODEV;
  42
  43         return 0;
  44 }
  45
  46 static struct acpi_bus_type usb_acpi_bus = {
  47         .bus = &usb_bus_type,
  48         .find_bridge = NULL,
  49         .find_device = usb_acpi_find_device,
  50 };
  51
  52 int usb_acpi_register(void)
  53 {
  54         return register_acpi_bus_type(&usb_acpi_bus);
  55 }
  56
  57 void usb_acpi_unregister(void)
  58 {
  59         unregister_acpi_bus_type(&usb_acpi_bus);
  60 }