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