/*
* 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_check_upc(struct usb_device *udev, acpi_handle handle)
{
acpi_status status;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *upc;
int ret = 0;
status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
if (ACPI_FAILURE(status))
return -ENODEV;
upc = buffer.pointer;
if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
|| upc->package.count != 4) {
ret = -EINVAL;
goto out;
}
if (upc->package.elements[0].integer.value)
udev->removable = USB_DEVICE_REMOVABLE;
else
udev->removable = USB_DEVICE_FIXED;
out:
kfree(upc);
return ret;
}
static int usb_acpi_check_pld(struct usb_device *udev, acpi_handle handle)
{
acpi_status status;
struct acpi_pld pld;
status = acpi_get_physical_device_location(handle, &pld);
if (ACPI_FAILURE(status))
return -ENODEV;
if (pld.user_visible)
udev->removable = USB_DEVICE_REMOVABLE;
else
udev->removable = USB_DEVICE_FIXED;
return 0;
}
static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
{
struct usb_device *udev;
acpi_handle *parent_handle;
int port_num;
/*
* In the ACPI DSDT table, only usb root hub and usb ports are
* acpi device nodes. The hierarchy like following.
* Device (EHC1)
* Device (HUBN)
* Device (PR01)
* Device (PR11)
* Device (PR12)
* Device (PR13)
* ...
* So all binding process is divided into two parts. binding
* root hub and usb ports.
*/
if (is_usb_device(dev)) {
udev = to_usb_device(dev);
if (udev->parent)
return -ENODEV;
/* root hub's parent is the usb hcd. */
parent_handle = DEVICE_ACPI_HANDLE(dev->parent);
*handle = acpi_get_child(parent_handle, udev->portnum);
if (!*handle)
return -ENODEV;
return 0;
} else if (is_usb_port(dev)) {
sscanf(dev_name(dev), "port%d", &port_num);
/* Get the struct usb_device point of port's hub */
udev = to_usb_device(dev->parent->parent);
/*
* The root hub ports' parent is the root hub. The non-root-hub
* ports' parent is the parent hub port which the hub is
* connected to.
*/
if (!udev->parent) {
*handle = acpi_get_child(DEVICE_ACPI_HANDLE(&udev->dev),
port_num);
if (!*handle)
return -ENODEV;
} else {
parent_handle =
usb_get_hub_port_acpi_handle(udev->parent,
udev->portnum);
if (!parent_handle)
return -ENODEV;
*handle = acpi_get_child(parent_handle, port_num);
if (!*handle)
return -ENODEV;
}
} else
return -ENODEV;
/*
* PLD will tell us whether a port is removable to the user or
* not. If we don't get an answer from PLD (it's not present
* or it's malformed) then try to infer it from UPC. If a
* device isn't connectable then it's probably not removable.
*/
if (usb_acpi_check_pld(udev, *handle) != 0)
usb_acpi_check_upc(udev, *handle);
return 0;
}
static struct acpi_bus_type usb_acpi_bus = {
.bus = &usb_bus_type,
.find_bridge = usb_acpi_find_device,
.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);
}
