4 * Copyright 2012 Red Hat <mjg@redhat.com>
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.
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>
22 static int usb_acpi_check_upc(struct usb_device
*udev
, acpi_handle handle
)
25 struct acpi_buffer buffer
= { ACPI_ALLOCATE_BUFFER
, NULL
};
26 union acpi_object
*upc
;
29 status
= acpi_evaluate_object(handle
, "_UPC", NULL
, &buffer
);
31 if (ACPI_FAILURE(status
))
36 if (!upc
|| (upc
->type
!= ACPI_TYPE_PACKAGE
)
37 || upc
->package
.count
!= 4) {
42 if (upc
->package
.elements
[0].integer
.value
)
43 udev
->removable
= USB_DEVICE_REMOVABLE
;
45 udev
->removable
= USB_DEVICE_FIXED
;
52 static int usb_acpi_check_pld(struct usb_device
*udev
, acpi_handle handle
)
57 status
= acpi_get_physical_device_location(handle
, &pld
);
59 if (ACPI_FAILURE(status
))
63 udev
->removable
= USB_DEVICE_REMOVABLE
;
65 udev
->removable
= USB_DEVICE_FIXED
;
70 static int usb_acpi_find_device(struct device
*dev
, acpi_handle
*handle
)
72 struct usb_device
*udev
;
73 acpi_handle
*parent_handle
;
77 * In the ACPI DSDT table, only usb root hub and usb ports are
78 * acpi device nodes. The hierarchy like following.
86 * So all binding process is divided into two parts. binding
87 * root hub and usb ports.
89 if (is_usb_device(dev
)) {
90 udev
= to_usb_device(dev
);
93 /* root hub's parent is the usb hcd. */
94 parent_handle
= DEVICE_ACPI_HANDLE(dev
->parent
);
95 *handle
= acpi_get_child(parent_handle
, udev
->portnum
);
99 } else if (is_usb_port(dev
)) {
100 sscanf(dev_name(dev
), "port%d", &port_num
);
101 /* Get the struct usb_device point of port's hub */
102 udev
= to_usb_device(dev
->parent
->parent
);
105 * The root hub ports' parent is the root hub. The non-root-hub
106 * ports' parent is the parent hub port which the hub is
110 *handle
= acpi_get_child(DEVICE_ACPI_HANDLE(&udev
->dev
),
116 usb_get_hub_port_acpi_handle(udev
->parent
,
121 *handle
= acpi_get_child(parent_handle
, port_num
);
129 * PLD will tell us whether a port is removable to the user or
130 * not. If we don't get an answer from PLD (it's not present
131 * or it's malformed) then try to infer it from UPC. If a
132 * device isn't connectable then it's probably not removable.
134 if (usb_acpi_check_pld(udev
, *handle
) != 0)
135 usb_acpi_check_upc(udev
, *handle
);
140 static struct acpi_bus_type usb_acpi_bus
= {
141 .bus
= &usb_bus_type
,
142 .find_bridge
= usb_acpi_find_device
,
143 .find_device
= usb_acpi_find_device
,
146 int usb_acpi_register(void)
148 return register_acpi_bus_type(&usb_acpi_bus
);
151 void usb_acpi_unregister(void)
153 unregister_acpi_bus_type(&usb_acpi_bus
);