drivers/usb/core/usb-acpi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * USB-ACPI glue code
   4  *
   5  * Copyright 2012 Red Hat <mjg@redhat.com>
   6  */
   7 #include <linux/module.h>
   8 #include <linux/usb.h>
   9 #include <linux/device.h>
  10 #include <linux/errno.h>
  11 #include <linux/kernel.h>
  12 #include <linux/acpi.h>
  13 #include <linux/pci.h>
  14 #include <linux/usb/hcd.h>
  15
  16 #include "hub.h"
  17
  18 /**
  19  * usb_acpi_power_manageable - check whether usb port has
  20  * acpi power resource.
  21  * @hdev: USB device belonging to the usb hub
  22  * @index: port index based zero
  23  *
  24  * Return true if the port has acpi power resource and false if no.
  25  */
  26 bool usb_acpi_power_manageable(struct usb_device *hdev, int index)
  27 {
  28         acpi_handle port_handle;
  29         int port1 = index + 1;
  30
  31         port_handle = usb_get_hub_port_acpi_handle(hdev,
  32                 port1);
  33         if (port_handle)
  34                 return acpi_bus_power_manageable(port_handle);
  35         else
  36                 return false;
  37 }
  38 EXPORT_SYMBOL_GPL(usb_acpi_power_manageable);
  39
  40 /**
  41  * usb_acpi_set_power_state - control usb port's power via acpi power
  42  * resource
  43  * @hdev: USB device belonging to the usb hub
  44  * @index: port index based zero
  45  * @enable: power state expected to be set
  46  *
  47  * Notice to use usb_acpi_power_manageable() to check whether the usb port
  48  * has acpi power resource before invoking this function.
  49  *
  50  * Returns 0 on success, else negative errno.
  51  */
  52 int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
  53 {
  54         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
  55         struct usb_port *port_dev;
  56         acpi_handle port_handle;
  57         unsigned char state;
  58         int port1 = index + 1;
  59         int error = -EINVAL;
  60
  61         if (!hub)
  62                 return -ENODEV;
  63         port_dev = hub->ports[port1 - 1];
  64
  65         port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, 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(&port_dev->dev, "acpi: power was set to %d\n", enable);
  77         else
  78                 dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
  79
  80         return error;
  81 }
  82 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
  83
  84 static enum usb_port_connect_type usb_acpi_get_connect_type(acpi_handle handle,
  85                 struct acpi_pld_info *pld)
  86 {
  87         enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
  88         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  89         union acpi_object *upc = NULL;
  90         acpi_status status;
  91
  92         /*
  93          * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
  94          * is user visible and _UPC indicates whether it is connectable. If
  95          * the port was visible and connectable, it could be freely connected
  96          * and disconnected with USB devices. If no visible and connectable,
  97          * a usb device is directly hard-wired to the port. If no visible and
  98          * no connectable, the port would be not used.
  99          */
 100         status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
 101         if (ACPI_FAILURE(status))
 102                 goto out;
 103
 104         upc = buffer.pointer;
 105         if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
 106                 goto out;
 107
 108         if (upc->package.elements[0].integer.value)
 109                 if (pld->user_visible)
 110                         connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
 111                 else
 112                         connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
 113         else if (!pld->user_visible)
 114                 connect_type = USB_PORT_NOT_USED;
 115 out:
 116         kfree(upc);
 117         return connect_type;
 118 }
 119
 120
 121 /*
 122  * Private to usb-acpi, all the core needs to know is that
 123  * port_dev->location is non-zero when it has been set by the firmware.
 124  */
 125 #define USB_ACPI_LOCATION_VALID (1 << 31)
 126
 127 static struct acpi_device *usb_acpi_find_port(struct acpi_device *parent,
 128                                               int raw)
 129 {
 130         struct acpi_device *adev;
 131
 132         if (!parent)
 133                 return NULL;
 134
 135         list_for_each_entry(adev, &parent->children, node) {
 136                 if (acpi_device_adr(adev) == raw)
 137                         return adev;
 138         }
 139
 140         return acpi_find_child_device(parent, raw, false);
 141 }
 142
 143 static struct acpi_device *
 144 usb_acpi_get_companion_for_port(struct usb_port *port_dev)
 145 {
 146         struct usb_device *udev;
 147         struct acpi_device *adev;
 148         acpi_handle *parent_handle;
 149         int port1;
 150
 151         /* Get the struct usb_device point of port's hub */
 152         udev = to_usb_device(port_dev->dev.parent->parent);
 153
 154         /*
 155          * The root hub ports' parent is the root hub. The non-root-hub
 156          * ports' parent is the parent hub port which the hub is
 157          * connected to.
 158          */
 159         if (!udev->parent) {
 160                 adev = ACPI_COMPANION(&udev->dev);
 161                 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
 162                                                      port_dev->portnum);
 163         } else {
 164                 parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
 165                                                              udev->portnum);
 166                 if (!parent_handle)
 167                         return NULL;
 168
 169                 acpi_bus_get_device(parent_handle, &adev);
 170                 port1 = port_dev->portnum;
 171         }
 172
 173         return usb_acpi_find_port(adev, port1);
 174 }
 175
 176 static struct acpi_device *
 177 usb_acpi_find_companion_for_port(struct usb_port *port_dev)
 178 {
 179         struct acpi_device *adev;
 180         struct acpi_pld_info *pld;
 181         acpi_handle *handle;
 182         acpi_status status;
 183
 184         adev = usb_acpi_get_companion_for_port(port_dev);
 185         if (!adev)
 186                 return NULL;
 187
 188         handle = adev->handle;
 189         status = acpi_get_physical_device_location(handle, &pld);
 190         if (ACPI_SUCCESS(status) && pld) {
 191                 port_dev->location = USB_ACPI_LOCATION_VALID
 192                         | pld->group_token << 8 | pld->group_position;
 193                 port_dev->connect_type = usb_acpi_get_connect_type(handle, pld);
 194                 ACPI_FREE(pld);
 195         }
 196
 197         return adev;
 198 }
 199
 200 static struct acpi_device *
 201 usb_acpi_find_companion_for_device(struct usb_device *udev)
 202 {
 203         struct acpi_device *adev;
 204         struct usb_port *port_dev;
 205         struct usb_hub *hub;
 206
 207         if (!udev->parent) {
 208                 /* root hub is only child (_ADR=0) under its parent, the HC */
 209                 adev = ACPI_COMPANION(udev->dev.parent);
 210                 return acpi_find_child_device(adev, 0, false);
 211         }
 212
 213         hub = usb_hub_to_struct_hub(udev->parent);
 214         if (!hub)
 215                 return NULL;
 216
 217         /*
 218          * This is an embedded USB device connected to a port and such
 219          * devices share port's ACPI companion.
 220          */
 221         port_dev = hub->ports[udev->portnum - 1];
 222         return usb_acpi_get_companion_for_port(port_dev);
 223 }
 224
 225 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
 226 {
 227         /*
 228          * The USB hierarchy like following:
 229          *
 230          * Device (EHC1)
 231          *      Device (HUBN)
 232          *              Device (PR01)
 233          *                      Device (PR11)
 234          *                      Device (PR12)
 235          *                              Device (FN12)
 236          *                              Device (FN13)
 237          *                      Device (PR13)
 238          *                      ...
 239          * where HUBN is root hub, and PRNN are USB ports and devices
 240          * connected to them, and FNNN are individualk functions for
 241          * connected composite USB devices. PRNN and FNNN may contain
 242          * _CRS and other methods describing sideband resources for
 243          * the connected device.
 244          *
 245          * On the kernel side both root hub and embedded USB devices are
 246          * represented as instances of usb_device structure, and ports
 247          * are represented as usb_port structures, so the whole process
 248          * is split into 2 parts: finding companions for devices and
 249          * finding companions for ports.
 250          *
 251          * Note that we do not handle individual functions of composite
 252          * devices yet, for that we would need to assign companions to
 253          * devices corresponding to USB interfaces.
 254          */
 255         if (is_usb_device(dev))
 256                 return usb_acpi_find_companion_for_device(to_usb_device(dev));
 257         else if (is_usb_port(dev))
 258                 return usb_acpi_find_companion_for_port(to_usb_port(dev));
 259
 260         return NULL;
 261 }
 262
 263 static bool usb_acpi_bus_match(struct device *dev)
 264 {
 265         return is_usb_device(dev) || is_usb_port(dev);
 266 }
 267
 268 static struct acpi_bus_type usb_acpi_bus = {
 269         .name = "USB",
 270         .match = usb_acpi_bus_match,
 271         .find_companion = usb_acpi_find_companion,
 272 };
 273
 274 int usb_acpi_register(void)
 275 {
 276         return register_acpi_bus_type(&usb_acpi_bus);
 277 }
 278
 279 void usb_acpi_unregister(void)
 280 {
 281         unregister_acpi_bus_type(&usb_acpi_bus);
 282 }