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 #define UUID_USB_CONTROLLER_DSM "ce2ee385-00e6-48cb-9f05-2edb927c4899"
  41 #define USB_DSM_DISABLE_U1_U2_FOR_PORT  5
  42
  43 /**
  44  * usb_acpi_port_lpm_incapable - check if lpm should be disabled for a port.
  45  * @hdev: USB device belonging to the usb hub
  46  * @index: zero based port index
  47  *
  48  * Some USB3 ports may not support USB3 link power management U1/U2 states
  49  * due to different retimer setup. ACPI provides _DSM method which returns 0x01
  50  * if U1 and U2 states should be disabled. Evaluate _DSM with:
  51  * Arg0: UUID = ce2ee385-00e6-48cb-9f05-2edb927c4899
  52  * Arg1: Revision ID = 0
  53  * Arg2: Function Index = 5
  54  * Arg3: (empty)
  55  *
  56  * Return 1 if USB3 port is LPM incapable, negative on error, otherwise 0
  57  */
  58
  59 int usb_acpi_port_lpm_incapable(struct usb_device *hdev, int index)
  60 {
  61         union acpi_object *obj;
  62         acpi_handle port_handle;
  63         int port1 = index + 1;
  64         guid_t guid;
  65         int ret;
  66
  67         ret = guid_parse(UUID_USB_CONTROLLER_DSM, &guid);
  68         if (ret)
  69                 return ret;
  70
  71         port_handle = usb_get_hub_port_acpi_handle(hdev, port1);
  72         if (!port_handle) {
  73                 dev_dbg(&hdev->dev, "port-%d no acpi handle\n", port1);
  74                 return -ENODEV;
  75         }
  76
  77         if (!acpi_check_dsm(port_handle, &guid, 0,
  78                             BIT(USB_DSM_DISABLE_U1_U2_FOR_PORT))) {
  79                 dev_dbg(&hdev->dev, "port-%d no _DSM function %d\n",
  80                         port1, USB_DSM_DISABLE_U1_U2_FOR_PORT);
  81                 return -ENODEV;
  82         }
  83
  84         obj = acpi_evaluate_dsm_typed(port_handle, &guid, 0,
  85                                       USB_DSM_DISABLE_U1_U2_FOR_PORT, NULL,
  86                                       ACPI_TYPE_INTEGER);
  87         if (!obj) {
  88                 dev_dbg(&hdev->dev, "evaluate port-%d _DSM failed\n", port1);
  89                 return -EINVAL;
  90         }
  91
  92         if (obj->integer.value == 0x01)
  93                 ret = 1;
  94
  95         ACPI_FREE(obj);
  96
  97         return ret;
  98 }
  99 EXPORT_SYMBOL_GPL(usb_acpi_port_lpm_incapable);
 100
 101 /**
 102  * usb_acpi_set_power_state - control usb port's power via acpi power
 103  * resource
 104  * @hdev: USB device belonging to the usb hub
 105  * @index: port index based zero
 106  * @enable: power state expected to be set
 107  *
 108  * Notice to use usb_acpi_power_manageable() to check whether the usb port
 109  * has acpi power resource before invoking this function.
 110  *
 111  * Returns 0 on success, else negative errno.
 112  */
 113 int usb_acpi_set_power_state(struct usb_device *hdev, int index, bool enable)
 114 {
 115         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
 116         struct usb_port *port_dev;
 117         acpi_handle port_handle;
 118         unsigned char state;
 119         int port1 = index + 1;
 120         int error = -EINVAL;
 121
 122         if (!hub)
 123                 return -ENODEV;
 124         port_dev = hub->ports[port1 - 1];
 125
 126         port_handle = (acpi_handle) usb_get_hub_port_acpi_handle(hdev, port1);
 127         if (!port_handle)
 128                 return error;
 129
 130         if (enable)
 131                 state = ACPI_STATE_D0;
 132         else
 133                 state = ACPI_STATE_D3_COLD;
 134
 135         error = acpi_bus_set_power(port_handle, state);
 136         if (!error)
 137                 dev_dbg(&port_dev->dev, "acpi: power was set to %d\n", enable);
 138         else
 139                 dev_dbg(&port_dev->dev, "acpi: power failed to be set\n");
 140
 141         return error;
 142 }
 143 EXPORT_SYMBOL_GPL(usb_acpi_set_power_state);
 144
 145 /**
 146  * usb_acpi_add_usb4_devlink - add device link to USB4 Host Interface for tunneled USB3 devices
 147  *
 148  * @udev: Tunneled USB3 device connected to a roothub.
 149  *
 150  * Adds a device link between a tunneled USB3 device and the USB4 Host Interface
 151  * device to ensure correct runtime PM suspend and resume order. This function
 152  * should only be called for tunneled USB3 devices.
 153  * The USB4 Host Interface this tunneled device depends on is found from the roothub
 154  * port ACPI device specific data _DSD entry.
 155  *
 156  * Return: negative error code on failure, 0 otherwise
 157  */
 158 static int usb_acpi_add_usb4_devlink(struct usb_device *udev)
 159 {
 160         const struct device_link *link;
 161         struct usb_port *port_dev;
 162         struct usb_hub *hub;
 163
 164         if (!udev->parent || udev->parent->parent)
 165                 return 0;
 166
 167         hub = usb_hub_to_struct_hub(udev->parent);
 168         port_dev = hub->ports[udev->portnum - 1];
 169
 170         struct fwnode_handle *nhi_fwnode __free(fwnode_handle) =
 171                 fwnode_find_reference(dev_fwnode(&port_dev->dev), "usb4-host-interface", 0);
 172
 173         if (IS_ERR(nhi_fwnode) || !nhi_fwnode->dev)
 174                 return 0;
 175
 176         link = device_link_add(&port_dev->child->dev, nhi_fwnode->dev,
 177                                DL_FLAG_STATELESS |
 178                                DL_FLAG_RPM_ACTIVE |
 179                                DL_FLAG_PM_RUNTIME);
 180         if (!link) {
 181                 dev_err(&port_dev->dev, "Failed to created device link from %s to %s\n",
 182                         dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));
 183                 return -EINVAL;
 184         }
 185
 186         dev_dbg(&port_dev->dev, "Created device link from %s to %s\n",
 187                 dev_name(&port_dev->child->dev), dev_name(nhi_fwnode->dev));
 188
 189         return 0;
 190 }
 191
 192 /*
 193  * Private to usb-acpi, all the core needs to know is that
 194  * port_dev->location is non-zero when it has been set by the firmware.
 195  */
 196 #define USB_ACPI_LOCATION_VALID (1 << 31)
 197
 198 static void
 199 usb_acpi_get_connect_type(struct usb_port *port_dev, acpi_handle *handle)
 200 {
 201         enum usb_port_connect_type connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
 202         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 203         union acpi_object *upc = NULL;
 204         struct acpi_pld_info *pld = NULL;
 205         acpi_status status;
 206
 207         /*
 208          * According to 9.14 in ACPI Spec 6.2. _PLD indicates whether usb port
 209          * is user visible and _UPC indicates whether it is connectable. If
 210          * the port was visible and connectable, it could be freely connected
 211          * and disconnected with USB devices. If no visible and connectable,
 212          * a usb device is directly hard-wired to the port. If no visible and
 213          * no connectable, the port would be not used.
 214          */
 215
 216         status = acpi_get_physical_device_location(handle, &pld);
 217         if (ACPI_SUCCESS(status) && pld)
 218                 port_dev->location = USB_ACPI_LOCATION_VALID |
 219                         pld->group_token << 8 | pld->group_position;
 220
 221         status = acpi_evaluate_object(handle, "_UPC", NULL, &buffer);
 222         if (ACPI_FAILURE(status))
 223                 goto out;
 224
 225         upc = buffer.pointer;
 226         if (!upc || (upc->type != ACPI_TYPE_PACKAGE) || upc->package.count != 4)
 227                 goto out;
 228
 229         /* UPC states port is connectable */
 230         if (upc->package.elements[0].integer.value)
 231                 if (!pld)
 232                         ; /* keep connect_type as unknown */
 233                 else if (pld->user_visible)
 234                         connect_type = USB_PORT_CONNECT_TYPE_HOT_PLUG;
 235                 else
 236                         connect_type = USB_PORT_CONNECT_TYPE_HARD_WIRED;
 237         else
 238                 connect_type = USB_PORT_NOT_USED;
 239 out:
 240         port_dev->connect_type = connect_type;
 241         kfree(upc);
 242         ACPI_FREE(pld);
 243 }
 244
 245 static struct acpi_device *
 246 usb_acpi_get_companion_for_port(struct usb_port *port_dev)
 247 {
 248         struct usb_device *udev;
 249         struct acpi_device *adev;
 250         acpi_handle *parent_handle;
 251         int port1;
 252
 253         /* Get the struct usb_device point of port's hub */
 254         udev = to_usb_device(port_dev->dev.parent->parent);
 255
 256         /*
 257          * The root hub ports' parent is the root hub. The non-root-hub
 258          * ports' parent is the parent hub port which the hub is
 259          * connected to.
 260          */
 261         if (!udev->parent) {
 262                 adev = ACPI_COMPANION(&udev->dev);
 263                 port1 = usb_hcd_find_raw_port_number(bus_to_hcd(udev->bus),
 264                                                      port_dev->portnum);
 265         } else {
 266                 parent_handle = usb_get_hub_port_acpi_handle(udev->parent,
 267                                                              udev->portnum);
 268                 if (!parent_handle)
 269                         return NULL;
 270
 271                 adev = acpi_fetch_acpi_dev(parent_handle);
 272                 port1 = port_dev->portnum;
 273         }
 274
 275         return acpi_find_child_by_adr(adev, port1);
 276 }
 277
 278 static struct acpi_device *
 279 usb_acpi_find_companion_for_port(struct usb_port *port_dev)
 280 {
 281         struct acpi_device *adev;
 282
 283         adev = usb_acpi_get_companion_for_port(port_dev);
 284         if (!adev)
 285                 return NULL;
 286
 287         usb_acpi_get_connect_type(port_dev, adev->handle);
 288
 289         return adev;
 290 }
 291
 292 static struct acpi_device *
 293 usb_acpi_find_companion_for_device(struct usb_device *udev)
 294 {
 295         struct acpi_device *adev;
 296         struct usb_port *port_dev;
 297         struct usb_hub *hub;
 298
 299         if (!udev->parent) {
 300                 /*
 301                  * root hub is only child (_ADR=0) under its parent, the HC.
 302                  * sysdev pointer is the HC as seen from firmware.
 303                  */
 304                 adev = ACPI_COMPANION(udev->bus->sysdev);
 305                 return acpi_find_child_device(adev, 0, false);
 306         }
 307
 308         hub = usb_hub_to_struct_hub(udev->parent);
 309         if (!hub)
 310                 return NULL;
 311
 312
 313         /* Tunneled USB3 devices depend on USB4 Host Interface, set device link to it */
 314         if (udev->speed >= USB_SPEED_SUPER &&
 315             udev->tunnel_mode != USB_LINK_NATIVE)
 316                 usb_acpi_add_usb4_devlink(udev);
 317
 318         /*
 319          * This is an embedded USB device connected to a port and such
 320          * devices share port's ACPI companion.
 321          */
 322         port_dev = hub->ports[udev->portnum - 1];
 323         return usb_acpi_get_companion_for_port(port_dev);
 324 }
 325
 326 static struct acpi_device *usb_acpi_find_companion(struct device *dev)
 327 {
 328         /*
 329          * The USB hierarchy like following:
 330          *
 331          * Device (EHC1)
 332          *      Device (HUBN)
 333          *              Device (PR01)
 334          *                      Device (PR11)
 335          *                      Device (PR12)
 336          *                              Device (FN12)
 337          *                              Device (FN13)
 338          *                      Device (PR13)
 339          *                      ...
 340          * where HUBN is root hub, and PRNN are USB ports and devices
 341          * connected to them, and FNNN are individualk functions for
 342          * connected composite USB devices. PRNN and FNNN may contain
 343          * _CRS and other methods describing sideband resources for
 344          * the connected device.
 345          *
 346          * On the kernel side both root hub and embedded USB devices are
 347          * represented as instances of usb_device structure, and ports
 348          * are represented as usb_port structures, so the whole process
 349          * is split into 2 parts: finding companions for devices and
 350          * finding companions for ports.
 351          *
 352          * Note that we do not handle individual functions of composite
 353          * devices yet, for that we would need to assign companions to
 354          * devices corresponding to USB interfaces.
 355          */
 356         if (is_usb_device(dev))
 357                 return usb_acpi_find_companion_for_device(to_usb_device(dev));
 358         else if (is_usb_port(dev))
 359                 return usb_acpi_find_companion_for_port(to_usb_port(dev));
 360
 361         return NULL;
 362 }
 363
 364 static bool usb_acpi_bus_match(struct device *dev)
 365 {
 366         return is_usb_device(dev) || is_usb_port(dev);
 367 }
 368
 369 static struct acpi_bus_type usb_acpi_bus = {
 370         .name = "USB",
 371         .match = usb_acpi_bus_match,
 372         .find_companion = usb_acpi_find_companion,
 373 };
 374
 375 int usb_acpi_register(void)
 376 {
 377         return register_acpi_bus_type(&usb_acpi_bus);
 378 }
 379
 380 void usb_acpi_unregister(void)
 381 {
 382         unregister_acpi_bus_type(&usb_acpi_bus);
 383 }