linux/drivers/usb/core/usb-acpi.c
<<
>>
Prefs
   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 <linux/usb/hcd.h>
  19
  20#include "hub.h"
  21
  22/**
  23 * usb_acpi_power_manageable - check whether usb port has
  24 * acpi power resource.
  25 * @hdev: USB device belonging to the usb hub
  26 * @index: port index based zero
  27 *
  28 * Return true if the port has acpi power resource and false if no.
  29 */
  30bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
  31{
  32        acpi_handle port_handle;
  33        int port1 = index + 1;
  34
  35        port_handle = usb_get_hub_port_acpi_handle(hdev,
  36                port1);
  37        if (port_handle)
  38                return acpi_bus_power_manageable(port_handle);
  39        else
  40                return false;
  41}
  42EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
  43
  44/**
  45 * usb_acpi_set_power_state - control usb port's power via acpi power
  46 * resource
  47 * @hdev: USB device belonging to the usb hub
  48 * @index: port index based zero
  49 * @enable: power state expected to be set
  50 *
  51 * Notice to use usb_acpi_power_manageable() to check whether the usb port
  52 * has acpi power resource before invoking this function.
  53 *
  54 * Returns 0 on success, else negative errno.
  55 */
  56int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
  57{
  58        struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
  59        struct usb_port *port_dev;
  60        acpi_handle port_handle;
  61        unsigned char state;
  62        int port1 = index + 1;
  63        int error = -EINVAL;
  64
  65        if (!hub)
  66                return -ENODEV;
  67        port_dev = hub->ports[port1 - 1];
  68
  69        port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
  70        if (!port_handle)
  71                return error;
  72
  73        if (enable)
  74                state = ACPI_STATE_D0;
  75        else
  76                state = ACPI_STATE_D3_COLD;
  77
  78        error = acpi_bus_set_power(port_handle, state);
  79        if (!error)
  80                dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
  81        else
  82                dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
  83
  84        return error;
  85}
  86EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
  87
  88static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
  89                struct acpi_pld_info *pld)
  90{
  91        enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
  92        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  93        union acpi_object *upc;
  94        acpi_status status;
  95
  96        /*
  97         * According to ACPI Spec 9.13. PLD indicates whether usb port is
  98         * user visible and _UPC indicates whether it is connectable. If
  99         * the port was visible and connectable, it could be freely connected
 100         * and disconnected with USB devices. If no visible and connectable,
 101         * a usb device is directly hard-wired to the port. If no visible and
 102         * no connectable, the port would be not used.
 103         */
 104        status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
 105        upc = buffer.pointer;
 106        if (!upc || (upc->type != ACPI_TYPE_PACKAGE)
 107                || upc->package.count != 4) {
 108                goto out;
 109        }
 110
 111        if (upc->package.elements[0].integer.value)
 112                if (pld->user_visible)
 113                        connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
 114                else
 115                        connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
 116        else if (!pld->user_visible)
 117                connect_type = USB_PORT_NOT_USED;
 118out:
 119        kfree(upc);
 120        return connect_type;
 121}
 122
 123
 124/*
 125 * Private to usb-acpi, all the core needs to know is that
 126 * port_dev->location is non-zero when it has been set by the firmware.
 127 */
 128#define USB_ACPI_LOCATION_VALID (1 << 31)
 129
 130static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
 131                                              int raw)
 132{
 133        struct acpi_device *adev;
 134
 135        if (!parent)
 136                return NULL;
 137
 138        list_for_each_entry(adev, &parent->children, node) {
 139                if (acpi_device_adr(adev) == raw)
 140                        return adev;
 141        }
 142
 143        return acpi_find_child_device(parent, raw, false);
 144}
 145
 146static struct acpi_device *usb_acpi_find_companion(struct device *dev)
 147{
 148        struct usb_device *udev;
 149        struct acpi_device *adev;
 150        acpi_handle *parent_handle;
 151
 152        /*
 153         * In the ACPI DSDT table, only usb root hub and usb ports are
 154         * acpi device nodes. The hierarchy like following.
 155         * Device (EHC1)
 156         *      Device (HUBN)
 157         *              Device (PR01)
 158         *                      Device (PR11)
 159         *                      Device (PR12)
 160         *                      Device (PR13)
 161         *                      ...
 162         * So all binding process is divided into two parts. binding
 163         * root hub and usb ports.
 164         */
 165        if (is_usb_device(dev)) {
 166                udev = to_usb_device(dev);
 167                if (udev->parent)
 168                        return NULL;
 169
 170                /* root hub is only child (_ADR=0) under its parent, the HC */
 171                adev = ACPI_COMPANION(dev->parent);
 172                return acpi_find_child_device(adev, 0, false);
 173        } else if (is_usb_port(dev)) {
 174                struct usb_port *port_dev = to_usb_port(dev);
 175                int port1 = port_dev->portnum;
 176                struct acpi_pld_info *pld;
 177                acpi_handle *handle;
 178                acpi_status status;
 179
 180                /* Get the struct usb_device point of port's hub */
 181                udev = to_usb_device(dev->parent->parent);
 182
 183                /*
 184                 * The root hub ports' parent is the root hub. The non-root-hub
 185                 * ports' parent is the parent hub port which the hub is
 186                 * connected to.
 187                 */
 188                if (!udev->parent) {
 189                        struct usb_hcd *hcd = bus_to_hcd(udev->bus);
 190                        int raw;
 191
 192                        raw = usb_hcd_find_raw_port_number(hcd, port1);
 193
 194                        adev = usb_acpi_find_port(ACPI_COMPANION(&udev->dev),
 195                                                  raw);
 196
 197                        if (!adev)
 198                                return NULL;
 199                } else {
 200                        parent_handle =
 201                                usb_get_hub_port_acpi_handle(udev->parent,
 202                                udev->portnum);
 203                        if (!parent_handle)
 204                                return NULL;
 205
 206                        acpi_bus_get_device(parent_handle, &adev);
 207
 208                        adev = usb_acpi_find_port(adev, port1);
 209
 210                        if (!adev)
 211                                return NULL;
 212                }
 213                handle = adev->handle;
 214                status = acpi_get_physical_device_location(handle, &pld);
 215                if (ACPI_FAILURE(status) || !pld)
 216                        return adev;
 217
 218                port_dev->location = USB_ACPI_LOCATION_VALID
 219                        | pld->group_token << 8 | pld->group_position;
 220                port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
 221                ACPI_FREE(pld);
 222
 223                return adev;
 224        }
 225
 226        return NULL;
 227}
 228
 229static bool usb_acpi_bus_match(struct device *dev)
 230{
 231        return is_usb_device(dev) || is_usb_port(dev);
 232}
 233
 234static struct acpi_bus_type usb_acpi_bus = {
 235        .name = "USB",
 236        .match = usb_acpi_bus_match,
 237        .find_companion = usb_acpi_find_companion,
 238};
 239
 240int usb_acpi_register(void)
 241{
 242        return register_acpi_bus_type(&usb_acpi_bus);
 243}
 244
 245void usb_acpi_unregister(void)
 246{
 247        unregister_acpi_bus_type(&usb_acpi_bus);
 248}
 249