drivers/acpi/device

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This source file includes following definitions.
acpi_power_state_string
acpi_dev_pm_explicit_get
acpi_device_get_power
acpi_dev_pm_explicit_set
acpi_device_set_power
acpi_bus_set_power
acpi_bus_init_power
acpi_device_fix_up_power
acpi_device_update_power
acpi_bus_update_power
acpi_bus_power_manageable
acpi_pm_wakeup_event
acpi_pm_notify_handler
acpi_add_pm_notifier
acpi_remove_pm_notifier
acpi_bus_can_wakeup
acpi_pm_device_can_wakeup
acpi_dev_pm_get_state
acpi_pm_device_sleep_state
acpi_pm_notify_work_func
__acpi_device_wakeup_enable
acpi_device_wakeup_enable
acpi_device_wakeup_disable
__acpi_pm_set_device_wakeup
acpi_pm_set_device_wakeup
acpi_pm_set_bridge_wakeup
acpi_dev_pm_low_power
acpi_dev_pm_full_power
acpi_dev_suspend
acpi_dev_resume
acpi_subsys_runtime_suspend
acpi_subsys_runtime_resume
acpi_dev_needs_resume
acpi_subsys_prepare
acpi_subsys_complete
acpi_subsys_suspend
acpi_subsys_suspend_late
acpi_subsys_suspend_noirq
acpi_subsys_resume_noirq
acpi_subsys_resume_early
acpi_subsys_freeze
acpi_subsys_restore_early
acpi_subsys_poweroff
acpi_subsys_poweroff_late
acpi_subsys_poweroff_noirq
acpi_dev_pm_detach
acpi_dev_pm_attach
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * drivers/acpi/device_pm.c - ACPI device power management routines.
   4  *
   5  * Copyright (C) 2012, Intel Corp.
   6  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  */
  12 
  13 #include <linux/acpi.h>
  14 #include <linux/export.h>
  15 #include <linux/mutex.h>
  16 #include <linux/pm_qos.h>
  17 #include <linux/pm_domain.h>
  18 #include <linux/pm_runtime.h>
  19 #include <linux/suspend.h>
  20 
  21 #include "internal.h"
  22 
  23 #define _COMPONENT      ACPI_POWER_COMPONENT
  24 ACPI_MODULE_NAME("device_pm");
  25 
  26 /**
  27  * acpi_power_state_string - String representation of ACPI device power state.
  28  * @state: ACPI device power state to return the string representation of.
  29  */
  30 const char *acpi_power_state_string(int state)
  31 {
  32         switch (state) {
  33         case ACPI_STATE_D0:
  34                 return "D0";
  35         case ACPI_STATE_D1:
  36                 return "D1";
  37         case ACPI_STATE_D2:
  38                 return "D2";
  39         case ACPI_STATE_D3_HOT:
  40                 return "D3hot";
  41         case ACPI_STATE_D3_COLD:
  42                 return "D3cold";
  43         default:
  44                 return "(unknown)";
  45         }
  46 }
  47 
  48 static int acpi_dev_pm_explicit_get(struct acpi_device *device, int *state)
  49 {
  50         unsigned long long psc;
  51         acpi_status status;
  52 
  53         status = acpi_evaluate_integer(device->handle, "_PSC", NULL, &psc);
  54         if (ACPI_FAILURE(status))
  55                 return -ENODEV;
  56 
  57         *state = psc;
  58         return 0;
  59 }
  60 
  61 /**
  62  * acpi_device_get_power - Get power state of an ACPI device.
  63  * @device: Device to get the power state of.
  64  * @state: Place to store the power state of the device.
  65  *
  66  * This function does not update the device's power.state field, but it may
  67  * update its parent's power.state field (when the parent's power state is
  68  * unknown and the device's power state turns out to be D0).
  69  *
  70  * Also, it does not update power resource reference counters to ensure that
  71  * the power state returned by it will be persistent and it may return a power
  72  * state shallower than previously set by acpi_device_set_power() for @device
  73  * (if that power state depends on any power resources).
  74  */
  75 int acpi_device_get_power(struct acpi_device *device, int *state)
  76 {
  77         int result = ACPI_STATE_UNKNOWN;
  78         int error;
  79 
  80         if (!device || !state)
  81                 return -EINVAL;
  82 
  83         if (!device->flags.power_manageable) {
  84                 /* TBD: Non-recursive algorithm for walking up hierarchy. */
  85                 *state = device->parent ?
  86                         device->parent->power.state : ACPI_STATE_D0;
  87                 goto out;
  88         }
  89 
  90         /*
  91          * Get the device's power state from power resources settings and _PSC,
  92          * if available.
  93          */
  94         if (device->power.flags.power_resources) {
  95                 error = acpi_power_get_inferred_state(device, &result);
  96                 if (error)
  97                         return error;
  98         }
  99         if (device->power.flags.explicit_get) {
 100                 int psc;
 101 
 102                 error = acpi_dev_pm_explicit_get(device, &psc);
 103                 if (error)
 104                         return error;
 105 
 106                 /*
 107                  * The power resources settings may indicate a power state
 108                  * shallower than the actual power state of the device, because
 109                  * the same power resources may be referenced by other devices.
 110                  *
 111                  * For systems predating ACPI 4.0 we assume that D3hot is the
 112                  * deepest state that can be supported.
 113                  */
 114                 if (psc > result && psc < ACPI_STATE_D3_COLD)
 115                         result = psc;
 116                 else if (result == ACPI_STATE_UNKNOWN)
 117                         result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc;
 118         }
 119 
 120         /*
 121          * If we were unsure about the device parent's power state up to this
 122          * point, the fact that the device is in D0 implies that the parent has
 123          * to be in D0 too, except if ignore_parent is set.
 124          */
 125         if (!device->power.flags.ignore_parent && device->parent
 126             && device->parent->power.state == ACPI_STATE_UNKNOWN
 127             && result == ACPI_STATE_D0)
 128                 device->parent->power.state = ACPI_STATE_D0;
 129 
 130         *state = result;
 131 
 132  out:
 133         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n",
 134                           device->pnp.bus_id, acpi_power_state_string(*state)));
 135 
 136         return 0;
 137 }
 138 
 139 static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state)
 140 {
 141         if (adev->power.states[state].flags.explicit_set) {
 142                 char method[5] = { '_', 'P', 'S', '0' + state, '\0' };
 143                 acpi_status status;
 144 
 145                 status = acpi_evaluate_object(adev->handle, method, NULL, NULL);
 146                 if (ACPI_FAILURE(status))
 147                         return -ENODEV;
 148         }
 149         return 0;
 150 }
 151 
 152 /**
 153  * acpi_device_set_power - Set power state of an ACPI device.
 154  * @device: Device to set the power state of.
 155  * @state: New power state to set.
 156  *
 157  * Callers must ensure that the device is power manageable before using this
 158  * function.
 159  */
 160 int acpi_device_set_power(struct acpi_device *device, int state)
 161 {
 162         int target_state = state;
 163         int result = 0;
 164 
 165         if (!device || !device->flags.power_manageable
 166             || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
 167                 return -EINVAL;
 168 
 169         acpi_handle_debug(device->handle, "Power state change: %s -> %s\n",
 170                           acpi_power_state_string(device->power.state),
 171                           acpi_power_state_string(state));
 172 
 173         /* Make sure this is a valid target state */
 174 
 175         /* There is a special case for D0 addressed below. */
 176         if (state > ACPI_STATE_D0 && state == device->power.state) {
 177                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n",
 178                                   device->pnp.bus_id,
 179                                   acpi_power_state_string(state)));
 180                 return 0;
 181         }
 182 
 183         if (state == ACPI_STATE_D3_COLD) {
 184                 /*
 185                  * For transitions to D3cold we need to execute _PS3 and then
 186                  * possibly drop references to the power resources in use.
 187                  */
 188                 state = ACPI_STATE_D3_HOT;
 189                 /* If D3cold is not supported, use D3hot as the target state. */
 190                 if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid)
 191                         target_state = state;
 192         } else if (!device->power.states[state].flags.valid) {
 193                 dev_warn(&device->dev, "Power state %s not supported\n",
 194                          acpi_power_state_string(state));
 195                 return -ENODEV;
 196         }
 197 
 198         if (!device->power.flags.ignore_parent &&
 199             device->parent && (state < device->parent->power.state)) {
 200                 dev_warn(&device->dev,
 201                          "Cannot transition to power state %s for parent in %s\n",
 202                          acpi_power_state_string(state),
 203                          acpi_power_state_string(device->parent->power.state));
 204                 return -ENODEV;
 205         }
 206 
 207         /*
 208          * Transition Power
 209          * ----------------
 210          * In accordance with ACPI 6, _PSx is executed before manipulating power
 211          * resources, unless the target state is D0, in which case _PS0 is
 212          * supposed to be executed after turning the power resources on.
 213          */
 214         if (state > ACPI_STATE_D0) {
 215                 /*
 216                  * According to ACPI 6, devices cannot go from lower-power
 217                  * (deeper) states to higher-power (shallower) states.
 218                  */
 219                 if (state < device->power.state) {
 220                         dev_warn(&device->dev, "Cannot transition from %s to %s\n",
 221                                  acpi_power_state_string(device->power.state),
 222                                  acpi_power_state_string(state));
 223                         return -ENODEV;
 224                 }
 225 
 226                 /*
 227                  * If the device goes from D3hot to D3cold, _PS3 has been
 228                  * evaluated for it already, so skip it in that case.
 229                  */
 230                 if (device->power.state < ACPI_STATE_D3_HOT) {
 231                         result = acpi_dev_pm_explicit_set(device, state);
 232                         if (result)
 233                                 goto end;
 234                 }
 235 
 236                 if (device->power.flags.power_resources)
 237                         result = acpi_power_transition(device, target_state);
 238         } else {
 239                 int cur_state = device->power.state;
 240 
 241                 if (device->power.flags.power_resources) {
 242                         result = acpi_power_transition(device, ACPI_STATE_D0);
 243                         if (result)
 244                                 goto end;
 245                 }
 246 
 247                 if (cur_state == ACPI_STATE_D0) {
 248                         int psc;
 249 
 250                         /* Nothing to do here if _PSC is not present. */
 251                         if (!device->power.flags.explicit_get)
 252                                 return 0;
 253 
 254                         /*
 255                          * The power state of the device was set to D0 last
 256                          * time, but that might have happened before a
 257                          * system-wide transition involving the platform
 258                          * firmware, so it may be necessary to evaluate _PS0
 259                          * for the device here.  However, use extra care here
 260                          * and evaluate _PSC to check the device's current power
 261                          * state, and only invoke _PS0 if the evaluation of _PSC
 262                          * is successful and it returns a power state different
 263                          * from D0.
 264                          */
 265                         result = acpi_dev_pm_explicit_get(device, &psc);
 266                         if (result || psc == ACPI_STATE_D0)
 267                                 return 0;
 268                 }
 269 
 270                 result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
 271         }
 272 
 273  end:
 274         if (result) {
 275                 dev_warn(&device->dev, "Failed to change power state to %s\n",
 276                          acpi_power_state_string(target_state));
 277         } else {
 278                 device->power.state = target_state;
 279                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 280                                   "Device [%s] transitioned to %s\n",
 281                                   device->pnp.bus_id,
 282                                   acpi_power_state_string(target_state)));
 283         }
 284 
 285         return result;
 286 }
 287 EXPORT_SYMBOL(acpi_device_set_power);
 288 
 289 int acpi_bus_set_power(acpi_handle handle, int state)
 290 {
 291         struct acpi_device *device;
 292         int result;
 293 
 294         result = acpi_bus_get_device(handle, &device);
 295         if (result)
 296                 return result;
 297 
 298         return acpi_device_set_power(device, state);
 299 }
 300 EXPORT_SYMBOL(acpi_bus_set_power);
 301 
 302 int acpi_bus_init_power(struct acpi_device *device)
 303 {
 304         int state;
 305         int result;
 306 
 307         if (!device)
 308                 return -EINVAL;
 309 
 310         device->power.state = ACPI_STATE_UNKNOWN;
 311         if (!acpi_device_is_present(device)) {
 312                 device->flags.initialized = false;
 313                 return -ENXIO;
 314         }
 315 
 316         result = acpi_device_get_power(device, &state);
 317         if (result)
 318                 return result;
 319 
 320         if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) {
 321                 /* Reference count the power resources. */
 322                 result = acpi_power_on_resources(device, state);
 323                 if (result)
 324                         return result;
 325 
 326                 if (state == ACPI_STATE_D0) {
 327                         /*
 328                          * If _PSC is not present and the state inferred from
 329                          * power resources appears to be D0, it still may be
 330                          * necessary to execute _PS0 at this point, because
 331                          * another device using the same power resources may
 332                          * have been put into D0 previously and that's why we
 333                          * see D0 here.
 334                          */
 335                         result = acpi_dev_pm_explicit_set(device, state);
 336                         if (result)
 337                                 return result;
 338                 }
 339         } else if (state == ACPI_STATE_UNKNOWN) {
 340                 /*
 341                  * No power resources and missing _PSC?  Cross fingers and make
 342                  * it D0 in hope that this is what the BIOS put the device into.
 343                  * [We tried to force D0 here by executing _PS0, but that broke
 344                  * Toshiba P870-303 in a nasty way.]
 345                  */
 346                 state = ACPI_STATE_D0;
 347         }
 348         device->power.state = state;
 349         return 0;
 350 }
 351 
 352 /**
 353  * acpi_device_fix_up_power - Force device with missing _PSC into D0.
 354  * @device: Device object whose power state is to be fixed up.
 355  *
 356  * Devices without power resources and _PSC, but having _PS0 and _PS3 defined,
 357  * are assumed to be put into D0 by the BIOS.  However, in some cases that may
 358  * not be the case and this function should be used then.
 359  */
 360 int acpi_device_fix_up_power(struct acpi_device *device)
 361 {
 362         int ret = 0;
 363 
 364         if (!device->power.flags.power_resources
 365             && !device->power.flags.explicit_get
 366             && device->power.state == ACPI_STATE_D0)
 367                 ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0);
 368 
 369         return ret;
 370 }
 371 EXPORT_SYMBOL_GPL(acpi_device_fix_up_power);
 372 
 373 int acpi_device_update_power(struct acpi_device *device, int *state_p)
 374 {
 375         int state;
 376         int result;
 377 
 378         if (device->power.state == ACPI_STATE_UNKNOWN) {
 379                 result = acpi_bus_init_power(device);
 380                 if (!result && state_p)
 381                         *state_p = device->power.state;
 382 
 383                 return result;
 384         }
 385 
 386         result = acpi_device_get_power(device, &state);
 387         if (result)
 388                 return result;
 389 
 390         if (state == ACPI_STATE_UNKNOWN) {
 391                 state = ACPI_STATE_D0;
 392                 result = acpi_device_set_power(device, state);
 393                 if (result)
 394                         return result;
 395         } else {
 396                 if (device->power.flags.power_resources) {
 397                         /*
 398                          * We don't need to really switch the state, bu we need
 399                          * to update the power resources' reference counters.
 400                          */
 401                         result = acpi_power_transition(device, state);
 402                         if (result)
 403                                 return result;
 404                 }
 405                 device->power.state = state;
 406         }
 407         if (state_p)
 408                 *state_p = state;
 409 
 410         return 0;
 411 }
 412 EXPORT_SYMBOL_GPL(acpi_device_update_power);
 413 
 414 int acpi_bus_update_power(acpi_handle handle, int *state_p)
 415 {
 416         struct acpi_device *device;
 417         int result;
 418 
 419         result = acpi_bus_get_device(handle, &device);
 420         return result ? result : acpi_device_update_power(device, state_p);
 421 }
 422 EXPORT_SYMBOL_GPL(acpi_bus_update_power);
 423 
 424 bool acpi_bus_power_manageable(acpi_handle handle)
 425 {
 426         struct acpi_device *device;
 427         int result;
 428 
 429         result = acpi_bus_get_device(handle, &device);
 430         return result ? false : device->flags.power_manageable;
 431 }
 432 EXPORT_SYMBOL(acpi_bus_power_manageable);
 433 
 434 #ifdef CONFIG_PM
 435 static DEFINE_MUTEX(acpi_pm_notifier_lock);
 436 static DEFINE_MUTEX(acpi_pm_notifier_install_lock);
 437 
 438 void acpi_pm_wakeup_event(struct device *dev)
 439 {
 440         pm_wakeup_dev_event(dev, 0, acpi_s2idle_wakeup());
 441 }
 442 EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event);
 443 
 444 static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used)
 445 {
 446         struct acpi_device *adev;
 447 
 448         if (val != ACPI_NOTIFY_DEVICE_WAKE)
 449                 return;
 450 
 451         acpi_handle_debug(handle, "Wake notify\n");
 452 
 453         adev = acpi_bus_get_acpi_device(handle);
 454         if (!adev)
 455                 return;
 456 
 457         mutex_lock(&acpi_pm_notifier_lock);
 458 
 459         if (adev->wakeup.flags.notifier_present) {
 460                 pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup());
 461                 if (adev->wakeup.context.func) {
 462                         acpi_handle_debug(handle, "Running %pS for %s\n",
 463                                           adev->wakeup.context.func,
 464                                           dev_name(adev->wakeup.context.dev));
 465                         adev->wakeup.context.func(&adev->wakeup.context);
 466                 }
 467         }
 468 
 469         mutex_unlock(&acpi_pm_notifier_lock);
 470 
 471         acpi_bus_put_acpi_device(adev);
 472 }
 473 
 474 /**
 475  * acpi_add_pm_notifier - Register PM notify handler for given ACPI device.
 476  * @adev: ACPI device to add the notify handler for.
 477  * @dev: Device to generate a wakeup event for while handling the notification.
 478  * @func: Work function to execute when handling the notification.
 479  *
 480  * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of
 481  * PM wakeup events.  For example, wakeup events may be generated for bridges
 482  * if one of the devices below the bridge is signaling wakeup, even if the
 483  * bridge itself doesn't have a wakeup GPE associated with it.
 484  */
 485 acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev,
 486                         void (*func)(struct acpi_device_wakeup_context *context))
 487 {
 488         acpi_status status = AE_ALREADY_EXISTS;
 489 
 490         if (!dev && !func)
 491                 return AE_BAD_PARAMETER;
 492 
 493         mutex_lock(&acpi_pm_notifier_install_lock);
 494 
 495         if (adev->wakeup.flags.notifier_present)
 496                 goto out;
 497 
 498         status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
 499                                              acpi_pm_notify_handler, NULL);
 500         if (ACPI_FAILURE(status))
 501                 goto out;
 502 
 503         mutex_lock(&acpi_pm_notifier_lock);
 504         adev->wakeup.ws = wakeup_source_register(&adev->dev,
 505                                                  dev_name(&adev->dev));
 506         adev->wakeup.context.dev = dev;
 507         adev->wakeup.context.func = func;
 508         adev->wakeup.flags.notifier_present = true;
 509         mutex_unlock(&acpi_pm_notifier_lock);
 510 
 511  out:
 512         mutex_unlock(&acpi_pm_notifier_install_lock);
 513         return status;
 514 }
 515 
 516 /**
 517  * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device.
 518  * @adev: ACPI device to remove the notifier from.
 519  */
 520 acpi_status acpi_remove_pm_notifier(struct acpi_device *adev)
 521 {
 522         acpi_status status = AE_BAD_PARAMETER;
 523 
 524         mutex_lock(&acpi_pm_notifier_install_lock);
 525 
 526         if (!adev->wakeup.flags.notifier_present)
 527                 goto out;
 528 
 529         status = acpi_remove_notify_handler(adev->handle,
 530                                             ACPI_SYSTEM_NOTIFY,
 531                                             acpi_pm_notify_handler);
 532         if (ACPI_FAILURE(status))
 533                 goto out;
 534 
 535         mutex_lock(&acpi_pm_notifier_lock);
 536         adev->wakeup.context.func = NULL;
 537         adev->wakeup.context.dev = NULL;
 538         wakeup_source_unregister(adev->wakeup.ws);
 539         adev->wakeup.flags.notifier_present = false;
 540         mutex_unlock(&acpi_pm_notifier_lock);
 541 
 542  out:
 543         mutex_unlock(&acpi_pm_notifier_install_lock);
 544         return status;
 545 }
 546 
 547 bool acpi_bus_can_wakeup(acpi_handle handle)
 548 {
 549         struct acpi_device *device;
 550         int result;
 551 
 552         result = acpi_bus_get_device(handle, &device);
 553         return result ? false : device->wakeup.flags.valid;
 554 }
 555 EXPORT_SYMBOL(acpi_bus_can_wakeup);
 556 
 557 bool acpi_pm_device_can_wakeup(struct device *dev)
 558 {
 559         struct acpi_device *adev = ACPI_COMPANION(dev);
 560 
 561         return adev ? acpi_device_can_wakeup(adev) : false;
 562 }
 563 
 564 /**
 565  * acpi_dev_pm_get_state - Get preferred power state of ACPI device.
 566  * @dev: Device whose preferred target power state to return.
 567  * @adev: ACPI device node corresponding to @dev.
 568  * @target_state: System state to match the resultant device state.
 569  * @d_min_p: Location to store the highest power state available to the device.
 570  * @d_max_p: Location to store the lowest power state available to the device.
 571  *
 572  * Find the lowest power (highest number) and highest power (lowest number) ACPI
 573  * device power states that the device can be in while the system is in the
 574  * state represented by @target_state.  Store the integer numbers representing
 575  * those stats in the memory locations pointed to by @d_max_p and @d_min_p,
 576  * respectively.
 577  *
 578  * Callers must ensure that @dev and @adev are valid pointers and that @adev
 579  * actually corresponds to @dev before using this function.
 580  *
 581  * Returns 0 on success or -ENODATA when one of the ACPI methods fails or
 582  * returns a value that doesn't make sense.  The memory locations pointed to by
 583  * @d_max_p and @d_min_p are only modified on success.
 584  */
 585 static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev,
 586                                  u32 target_state, int *d_min_p, int *d_max_p)
 587 {
 588         char method[] = { '_', 'S', '0' + target_state, 'D', '\0' };
 589         acpi_handle handle = adev->handle;
 590         unsigned long long ret;
 591         int d_min, d_max;
 592         bool wakeup = false;
 593         bool has_sxd = false;
 594         acpi_status status;
 595 
 596         /*
 597          * If the system state is S0, the lowest power state the device can be
 598          * in is D3cold, unless the device has _S0W and is supposed to signal
 599          * wakeup, in which case the return value of _S0W has to be used as the
 600          * lowest power state available to the device.
 601          */
 602         d_min = ACPI_STATE_D0;
 603         d_max = ACPI_STATE_D3_COLD;
 604 
 605         /*
 606          * If present, _SxD methods return the minimum D-state (highest power
 607          * state) we can use for the corresponding S-states.  Otherwise, the
 608          * minimum D-state is D0 (ACPI 3.x).
 609          */
 610         if (target_state > ACPI_STATE_S0) {
 611                 /*
 612                  * We rely on acpi_evaluate_integer() not clobbering the integer
 613                  * provided if AE_NOT_FOUND is returned.
 614                  */
 615                 ret = d_min;
 616                 status = acpi_evaluate_integer(handle, method, NULL, &ret);
 617                 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND)
 618                     || ret > ACPI_STATE_D3_COLD)
 619                         return -ENODATA;
 620 
 621                 /*
 622                  * We need to handle legacy systems where D3hot and D3cold are
 623                  * the same and 3 is returned in both cases, so fall back to
 624                  * D3cold if D3hot is not a valid state.
 625                  */
 626                 if (!adev->power.states[ret].flags.valid) {
 627                         if (ret == ACPI_STATE_D3_HOT)
 628                                 ret = ACPI_STATE_D3_COLD;
 629                         else
 630                                 return -ENODATA;
 631                 }
 632 
 633                 if (status == AE_OK)
 634                         has_sxd = true;
 635 
 636                 d_min = ret;
 637                 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid
 638                         && adev->wakeup.sleep_state >= target_state;
 639         } else {
 640                 wakeup = adev->wakeup.flags.valid;
 641         }
 642 
 643         /*
 644          * If _PRW says we can wake up the system from the target sleep state,
 645          * the D-state returned by _SxD is sufficient for that (we assume a
 646          * wakeup-aware driver if wake is set).  Still, if _SxW exists
 647          * (ACPI 3.x), it should return the maximum (lowest power) D-state that
 648          * can wake the system.  _S0W may be valid, too.
 649          */
 650         if (wakeup) {
 651                 method[3] = 'W';
 652                 status = acpi_evaluate_integer(handle, method, NULL, &ret);
 653                 if (status == AE_NOT_FOUND) {
 654                         /* No _SxW. In this case, the ACPI spec says that we
 655                          * must not go into any power state deeper than the
 656                          * value returned from _SxD.
 657                          */
 658                         if (has_sxd && target_state > ACPI_STATE_S0)
 659                                 d_max = d_min;
 660                 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) {
 661                         /* Fall back to D3cold if ret is not a valid state. */
 662                         if (!adev->power.states[ret].flags.valid)
 663                                 ret = ACPI_STATE_D3_COLD;
 664 
 665                         d_max = ret > d_min ? ret : d_min;
 666                 } else {
 667                         return -ENODATA;
 668                 }
 669         }
 670 
 671         if (d_min_p)
 672                 *d_min_p = d_min;
 673 
 674         if (d_max_p)
 675                 *d_max_p = d_max;
 676 
 677         return 0;
 678 }
 679 
 680 /**
 681  * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
 682  * @dev: Device whose preferred target power state to return.
 683  * @d_min_p: Location to store the upper limit of the allowed states range.
 684  * @d_max_in: Deepest low-power state to take into consideration.
 685  * Return value: Preferred power state of the device on success, -ENODEV
 686  * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is
 687  * incorrect, or -ENODATA on ACPI method failure.
 688  *
 689  * The caller must ensure that @dev is valid before using this function.
 690  */
 691 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
 692 {
 693         struct acpi_device *adev;
 694         int ret, d_min, d_max;
 695 
 696         if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD)
 697                 return -EINVAL;
 698 
 699         if (d_max_in > ACPI_STATE_D2) {
 700                 enum pm_qos_flags_status stat;
 701 
 702                 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF);
 703                 if (stat == PM_QOS_FLAGS_ALL)
 704                         d_max_in = ACPI_STATE_D2;
 705         }
 706 
 707         adev = ACPI_COMPANION(dev);
 708         if (!adev) {
 709                 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
 710                 return -ENODEV;
 711         }
 712 
 713         ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(),
 714                                     &d_min, &d_max);
 715         if (ret)
 716                 return ret;
 717 
 718         if (d_max_in < d_min)
 719                 return -EINVAL;
 720 
 721         if (d_max > d_max_in) {
 722                 for (d_max = d_max_in; d_max > d_min; d_max--) {
 723                         if (adev->power.states[d_max].flags.valid)
 724                                 break;
 725                 }
 726         }
 727 
 728         if (d_min_p)
 729                 *d_min_p = d_min;
 730 
 731         return d_max;
 732 }
 733 EXPORT_SYMBOL(acpi_pm_device_sleep_state);
 734 
 735 /**
 736  * acpi_pm_notify_work_func - ACPI devices wakeup notification work function.
 737  * @context: Device wakeup context.
 738  */
 739 static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context)
 740 {
 741         struct device *dev = context->dev;
 742 
 743         if (dev) {
 744                 pm_wakeup_event(dev, 0);
 745                 pm_request_resume(dev);
 746         }
 747 }
 748 
 749 static DEFINE_MUTEX(acpi_wakeup_lock);
 750 
 751 static int __acpi_device_wakeup_enable(struct acpi_device *adev,
 752                                        u32 target_state, int max_count)
 753 {
 754         struct acpi_device_wakeup *wakeup = &adev->wakeup;
 755         acpi_status status;
 756         int error = 0;
 757 
 758         mutex_lock(&acpi_wakeup_lock);
 759 
 760         if (wakeup->enable_count >= max_count)
 761                 goto out;
 762 
 763         if (wakeup->enable_count > 0)
 764                 goto inc;
 765 
 766         error = acpi_enable_wakeup_device_power(adev, target_state);
 767         if (error)
 768                 goto out;
 769 
 770         status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number);
 771         if (ACPI_FAILURE(status)) {
 772                 acpi_disable_wakeup_device_power(adev);
 773                 error = -EIO;
 774                 goto out;
 775         }
 776 
 777         acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",
 778                           (unsigned int)wakeup->gpe_number);
 779 
 780 inc:
 781         wakeup->enable_count++;
 782 
 783 out:
 784         mutex_unlock(&acpi_wakeup_lock);
 785         return error;
 786 }
 787 
 788 /**
 789  * acpi_device_wakeup_enable - Enable wakeup functionality for device.
 790  * @adev: ACPI device to enable wakeup functionality for.
 791  * @target_state: State the system is transitioning into.
 792  *
 793  * Enable the GPE associated with @adev so that it can generate wakeup signals
 794  * for the device in response to external (remote) events and enable wakeup
 795  * power for it.
 796  *
 797  * Callers must ensure that @adev is a valid ACPI device node before executing
 798  * this function.
 799  */
 800 static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state)
 801 {
 802         return __acpi_device_wakeup_enable(adev, target_state, 1);
 803 }
 804 
 805 /**
 806  * acpi_device_wakeup_disable - Disable wakeup functionality for device.
 807  * @adev: ACPI device to disable wakeup functionality for.
 808  *
 809  * Disable the GPE associated with @adev and disable wakeup power for it.
 810  *
 811  * Callers must ensure that @adev is a valid ACPI device node before executing
 812  * this function.
 813  */
 814 static void acpi_device_wakeup_disable(struct acpi_device *adev)
 815 {
 816         struct acpi_device_wakeup *wakeup = &adev->wakeup;
 817 
 818         mutex_lock(&acpi_wakeup_lock);
 819 
 820         if (!wakeup->enable_count)
 821                 goto out;
 822 
 823         acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
 824         acpi_disable_wakeup_device_power(adev);
 825 
 826         wakeup->enable_count--;
 827 
 828 out:
 829         mutex_unlock(&acpi_wakeup_lock);
 830 }
 831 
 832 static int __acpi_pm_set_device_wakeup(struct device *dev, bool enable,
 833                                        int max_count)
 834 {
 835         struct acpi_device *adev;
 836         int error;
 837 
 838         adev = ACPI_COMPANION(dev);
 839         if (!adev) {
 840                 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__);
 841                 return -ENODEV;
 842         }
 843 
 844         if (!acpi_device_can_wakeup(adev))
 845                 return -EINVAL;
 846 
 847         if (!enable) {
 848                 acpi_device_wakeup_disable(adev);
 849                 dev_dbg(dev, "Wakeup disabled by ACPI\n");
 850                 return 0;
 851         }
 852 
 853         error = __acpi_device_wakeup_enable(adev, acpi_target_system_state(),
 854                                             max_count);
 855         if (!error)
 856                 dev_dbg(dev, "Wakeup enabled by ACPI\n");
 857 
 858         return error;
 859 }
 860 
 861 /**
 862  * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device.
 863  * @dev: Device to enable/disable to generate wakeup events.
 864  * @enable: Whether to enable or disable the wakeup functionality.
 865  */
 866 int acpi_pm_set_device_wakeup(struct device *dev, bool enable)
 867 {
 868         return __acpi_pm_set_device_wakeup(dev, enable, 1);
 869 }
 870 EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup);
 871 
 872 /**
 873  * acpi_pm_set_bridge_wakeup - Enable/disable remote wakeup for given bridge.
 874  * @dev: Bridge device to enable/disable to generate wakeup events.
 875  * @enable: Whether to enable or disable the wakeup functionality.
 876  */
 877 int acpi_pm_set_bridge_wakeup(struct device *dev, bool enable)
 878 {
 879         return __acpi_pm_set_device_wakeup(dev, enable, INT_MAX);
 880 }
 881 EXPORT_SYMBOL_GPL(acpi_pm_set_bridge_wakeup);
 882 
 883 /**
 884  * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
 885  * @dev: Device to put into a low-power state.
 886  * @adev: ACPI device node corresponding to @dev.
 887  * @system_state: System state to choose the device state for.
 888  */
 889 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev,
 890                                  u32 system_state)
 891 {
 892         int ret, state;
 893 
 894         if (!acpi_device_power_manageable(adev))
 895                 return 0;
 896 
 897         ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state);
 898         return ret ? ret : acpi_device_set_power(adev, state);
 899 }
 900 
 901 /**
 902  * acpi_dev_pm_full_power - Put ACPI device into the full-power state.
 903  * @adev: ACPI device node to put into the full-power state.
 904  */
 905 static int acpi_dev_pm_full_power(struct acpi_device *adev)
 906 {
 907         return acpi_device_power_manageable(adev) ?
 908                 acpi_device_set_power(adev, ACPI_STATE_D0) : 0;
 909 }
 910 
 911 /**
 912  * acpi_dev_suspend - Put device into a low-power state using ACPI.
 913  * @dev: Device to put into a low-power state.
 914  * @wakeup: Whether or not to enable wakeup for the device.
 915  *
 916  * Put the given device into a low-power state using the standard ACPI
 917  * mechanism.  Set up remote wakeup if desired, choose the state to put the
 918  * device into (this checks if remote wakeup is expected to work too), and set
 919  * the power state of the device.
 920  */
 921 int acpi_dev_suspend(struct device *dev, bool wakeup)
 922 {
 923         struct acpi_device *adev = ACPI_COMPANION(dev);
 924         u32 target_state = acpi_target_system_state();
 925         int error;
 926 
 927         if (!adev)
 928                 return 0;
 929 
 930         if (wakeup && acpi_device_can_wakeup(adev)) {
 931                 error = acpi_device_wakeup_enable(adev, target_state);
 932                 if (error)
 933                         return -EAGAIN;
 934         } else {
 935                 wakeup = false;
 936         }
 937 
 938         error = acpi_dev_pm_low_power(dev, adev, target_state);
 939         if (error && wakeup)
 940                 acpi_device_wakeup_disable(adev);
 941 
 942         return error;
 943 }
 944 EXPORT_SYMBOL_GPL(acpi_dev_suspend);
 945 
 946 /**
 947  * acpi_dev_resume - Put device into the full-power state using ACPI.
 948  * @dev: Device to put into the full-power state.
 949  *
 950  * Put the given device into the full-power state using the standard ACPI
 951  * mechanism.  Set the power state of the device to ACPI D0 and disable wakeup.
 952  */
 953 int acpi_dev_resume(struct device *dev)
 954 {
 955         struct acpi_device *adev = ACPI_COMPANION(dev);
 956         int error;
 957 
 958         if (!adev)
 959                 return 0;
 960 
 961         error = acpi_dev_pm_full_power(adev);
 962         acpi_device_wakeup_disable(adev);
 963         return error;
 964 }
 965 EXPORT_SYMBOL_GPL(acpi_dev_resume);
 966 
 967 /**
 968  * acpi_subsys_runtime_suspend - Suspend device using ACPI.
 969  * @dev: Device to suspend.
 970  *
 971  * Carry out the generic runtime suspend procedure for @dev and use ACPI to put
 972  * it into a runtime low-power state.
 973  */
 974 int acpi_subsys_runtime_suspend(struct device *dev)
 975 {
 976         int ret = pm_generic_runtime_suspend(dev);
 977         return ret ? ret : acpi_dev_suspend(dev, true);
 978 }
 979 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend);
 980 
 981 /**
 982  * acpi_subsys_runtime_resume - Resume device using ACPI.
 983  * @dev: Device to Resume.
 984  *
 985  * Use ACPI to put the given device into the full-power state and carry out the
 986  * generic runtime resume procedure for it.
 987  */
 988 int acpi_subsys_runtime_resume(struct device *dev)
 989 {
 990         int ret = acpi_dev_resume(dev);
 991         return ret ? ret : pm_generic_runtime_resume(dev);
 992 }
 993 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
 994 
 995 #ifdef CONFIG_PM_SLEEP
 996 static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev)
 997 {
 998         u32 sys_target = acpi_target_system_state();
 999         int ret, state;
1000 
1001         if (!pm_runtime_suspended(dev) || !adev || (adev->wakeup.flags.valid &&
1002             device_may_wakeup(dev) != !!adev->wakeup.prepare_count))
1003                 return true;
1004 
1005         if (sys_target == ACPI_STATE_S0)
1006                 return false;
1007 
1008         if (adev->power.flags.dsw_present)
1009                 return true;
1010 
1011         ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state);
1012         if (ret)
1013                 return true;
1014 
1015         return state != adev->power.state;
1016 }
1017 
1018 /**
1019  * acpi_subsys_prepare - Prepare device for system transition to a sleep state.
1020  * @dev: Device to prepare.
1021  */
1022 int acpi_subsys_prepare(struct device *dev)
1023 {
1024         struct acpi_device *adev = ACPI_COMPANION(dev);
1025 
1026         if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) {
1027                 int ret = dev->driver->pm->prepare(dev);
1028 
1029                 if (ret < 0)
1030                         return ret;
1031 
1032                 if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE))
1033                         return 0;
1034         }
1035 
1036         return !acpi_dev_needs_resume(dev, adev);
1037 }
1038 EXPORT_SYMBOL_GPL(acpi_subsys_prepare);
1039 
1040 /**
1041  * acpi_subsys_complete - Finalize device's resume during system resume.
1042  * @dev: Device to handle.
1043  */
1044 void acpi_subsys_complete(struct device *dev)
1045 {
1046         pm_generic_complete(dev);
1047         /*
1048          * If the device had been runtime-suspended before the system went into
1049          * the sleep state it is going out of and it has never been resumed till
1050          * now, resume it in case the firmware powered it up.
1051          */
1052         if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
1053                 pm_request_resume(dev);
1054 }
1055 EXPORT_SYMBOL_GPL(acpi_subsys_complete);
1056 
1057 /**
1058  * acpi_subsys_suspend - Run the device driver's suspend callback.
1059  * @dev: Device to handle.
1060  *
1061  * Follow PCI and resume devices from runtime suspend before running their
1062  * system suspend callbacks, unless the driver can cope with runtime-suspended
1063  * devices during system suspend and there are no ACPI-specific reasons for
1064  * resuming them.
1065  */
1066 int acpi_subsys_suspend(struct device *dev)
1067 {
1068         if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1069             acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1070                 pm_runtime_resume(dev);
1071 
1072         return pm_generic_suspend(dev);
1073 }
1074 EXPORT_SYMBOL_GPL(acpi_subsys_suspend);
1075 
1076 /**
1077  * acpi_subsys_suspend_late - Suspend device using ACPI.
1078  * @dev: Device to suspend.
1079  *
1080  * Carry out the generic late suspend procedure for @dev and use ACPI to put
1081  * it into a low-power state during system transition into a sleep state.
1082  */
1083 int acpi_subsys_suspend_late(struct device *dev)
1084 {
1085         int ret;
1086 
1087         if (dev_pm_smart_suspend_and_suspended(dev))
1088                 return 0;
1089 
1090         ret = pm_generic_suspend_late(dev);
1091         return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev));
1092 }
1093 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late);
1094 
1095 /**
1096  * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback.
1097  * @dev: Device to suspend.
1098  */
1099 int acpi_subsys_suspend_noirq(struct device *dev)
1100 {
1101         int ret;
1102 
1103         if (dev_pm_smart_suspend_and_suspended(dev)) {
1104                 dev->power.may_skip_resume = true;
1105                 return 0;
1106         }
1107 
1108         ret = pm_generic_suspend_noirq(dev);
1109         if (ret)
1110                 return ret;
1111 
1112         /*
1113          * If the target system sleep state is suspend-to-idle, it is sufficient
1114          * to check whether or not the device's wakeup settings are good for
1115          * runtime PM.  Otherwise, the pm_resume_via_firmware() check will cause
1116          * acpi_subsys_complete() to take care of fixing up the device's state
1117          * anyway, if need be.
1118          */
1119         dev->power.may_skip_resume = device_may_wakeup(dev) ||
1120                                         !device_can_wakeup(dev);
1121 
1122         return 0;
1123 }
1124 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq);
1125 
1126 /**
1127  * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback.
1128  * @dev: Device to handle.
1129  */
1130 static int acpi_subsys_resume_noirq(struct device *dev)
1131 {
1132         if (dev_pm_may_skip_resume(dev))
1133                 return 0;
1134 
1135         /*
1136          * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend
1137          * during system suspend, so update their runtime PM status to "active"
1138          * as they will be put into D0 going forward.
1139          */
1140         if (dev_pm_smart_suspend_and_suspended(dev))
1141                 pm_runtime_set_active(dev);
1142 
1143         return pm_generic_resume_noirq(dev);
1144 }
1145 
1146 /**
1147  * acpi_subsys_resume_early - Resume device using ACPI.
1148  * @dev: Device to Resume.
1149  *
1150  * Use ACPI to put the given device into the full-power state and carry out the
1151  * generic early resume procedure for it during system transition into the
1152  * working state.
1153  */
1154 static int acpi_subsys_resume_early(struct device *dev)
1155 {
1156         int ret = acpi_dev_resume(dev);
1157         return ret ? ret : pm_generic_resume_early(dev);
1158 }
1159 
1160 /**
1161  * acpi_subsys_freeze - Run the device driver's freeze callback.
1162  * @dev: Device to handle.
1163  */
1164 int acpi_subsys_freeze(struct device *dev)
1165 {
1166         /*
1167          * Resume all runtime-suspended devices before creating a snapshot
1168          * image of system memory, because the restore kernel generally cannot
1169          * be expected to always handle them consistently and they need to be
1170          * put into the runtime-active metastate during system resume anyway,
1171          * so it is better to ensure that the state saved in the image will be
1172          * always consistent with that.
1173          */
1174         pm_runtime_resume(dev);
1175 
1176         return pm_generic_freeze(dev);
1177 }
1178 EXPORT_SYMBOL_GPL(acpi_subsys_freeze);
1179 
1180 /**
1181  * acpi_subsys_restore_early - Restore device using ACPI.
1182  * @dev: Device to restore.
1183  */
1184 int acpi_subsys_restore_early(struct device *dev)
1185 {
1186         int ret = acpi_dev_resume(dev);
1187         return ret ? ret : pm_generic_restore_early(dev);
1188 }
1189 EXPORT_SYMBOL_GPL(acpi_subsys_restore_early);
1190 
1191 /**
1192  * acpi_subsys_poweroff - Run the device driver's poweroff callback.
1193  * @dev: Device to handle.
1194  *
1195  * Follow PCI and resume devices from runtime suspend before running their
1196  * system poweroff callbacks, unless the driver can cope with runtime-suspended
1197  * devices during system suspend and there are no ACPI-specific reasons for
1198  * resuming them.
1199  */
1200 int acpi_subsys_poweroff(struct device *dev)
1201 {
1202         if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
1203             acpi_dev_needs_resume(dev, ACPI_COMPANION(dev)))
1204                 pm_runtime_resume(dev);
1205 
1206         return pm_generic_poweroff(dev);
1207 }
1208 EXPORT_SYMBOL_GPL(acpi_subsys_poweroff);
1209 
1210 /**
1211  * acpi_subsys_poweroff_late - Run the device driver's poweroff callback.
1212  * @dev: Device to handle.
1213  *
1214  * Carry out the generic late poweroff procedure for @dev and use ACPI to put
1215  * it into a low-power state during system transition into a sleep state.
1216  */
1217 static int acpi_subsys_poweroff_late(struct device *dev)
1218 {
1219         int ret;
1220 
1221         if (dev_pm_smart_suspend_and_suspended(dev))
1222                 return 0;
1223 
1224         ret = pm_generic_poweroff_late(dev);
1225         if (ret)
1226                 return ret;
1227 
1228         return acpi_dev_suspend(dev, device_may_wakeup(dev));
1229 }
1230 
1231 /**
1232  * acpi_subsys_poweroff_noirq - Run the driver's "noirq" poweroff callback.
1233  * @dev: Device to suspend.
1234  */
1235 static int acpi_subsys_poweroff_noirq(struct device *dev)
1236 {
1237         if (dev_pm_smart_suspend_and_suspended(dev))
1238                 return 0;
1239 
1240         return pm_generic_poweroff_noirq(dev);
1241 }
1242 #endif /* CONFIG_PM_SLEEP */
1243 
1244 static struct dev_pm_domain acpi_general_pm_domain = {
1245         .ops = {
1246                 .runtime_suspend = acpi_subsys_runtime_suspend,
1247                 .runtime_resume = acpi_subsys_runtime_resume,
1248 #ifdef CONFIG_PM_SLEEP
1249                 .prepare = acpi_subsys_prepare,
1250                 .complete = acpi_subsys_complete,
1251                 .suspend = acpi_subsys_suspend,
1252                 .suspend_late = acpi_subsys_suspend_late,
1253                 .suspend_noirq = acpi_subsys_suspend_noirq,
1254                 .resume_noirq = acpi_subsys_resume_noirq,
1255                 .resume_early = acpi_subsys_resume_early,
1256                 .freeze = acpi_subsys_freeze,
1257                 .poweroff = acpi_subsys_poweroff,
1258                 .poweroff_late = acpi_subsys_poweroff_late,
1259                 .poweroff_noirq = acpi_subsys_poweroff_noirq,
1260                 .restore_early = acpi_subsys_restore_early,
1261 #endif
1262         },
1263 };
1264 
1265 /**
1266  * acpi_dev_pm_detach - Remove ACPI power management from the device.
1267  * @dev: Device to take care of.
1268  * @power_off: Whether or not to try to remove power from the device.
1269  *
1270  * Remove the device from the general ACPI PM domain and remove its wakeup
1271  * notifier.  If @power_off is set, additionally remove power from the device if
1272  * possible.
1273  *
1274  * Callers must ensure proper synchronization of this function with power
1275  * management callbacks.
1276  */
1277 static void acpi_dev_pm_detach(struct device *dev, bool power_off)
1278 {
1279         struct acpi_device *adev = ACPI_COMPANION(dev);
1280 
1281         if (adev && dev->pm_domain == &acpi_general_pm_domain) {
1282                 dev_pm_domain_set(dev, NULL);
1283                 acpi_remove_pm_notifier(adev);
1284                 if (power_off) {
1285                         /*
1286                          * If the device's PM QoS resume latency limit or flags
1287                          * have been exposed to user space, they have to be
1288                          * hidden at this point, so that they don't affect the
1289                          * choice of the low-power state to put the device into.
1290                          */
1291                         dev_pm_qos_hide_latency_limit(dev);
1292                         dev_pm_qos_hide_flags(dev);
1293                         acpi_device_wakeup_disable(adev);
1294                         acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0);
1295                 }
1296         }
1297 }
1298 
1299 /**
1300  * acpi_dev_pm_attach - Prepare device for ACPI power management.
1301  * @dev: Device to prepare.
1302  * @power_on: Whether or not to power on the device.
1303  *
1304  * If @dev has a valid ACPI handle that has a valid struct acpi_device object
1305  * attached to it, install a wakeup notification handler for the device and
1306  * add it to the general ACPI PM domain.  If @power_on is set, the device will
1307  * be put into the ACPI D0 state before the function returns.
1308  *
1309  * This assumes that the @dev's bus type uses generic power management callbacks
1310  * (or doesn't use any power management callbacks at all).
1311  *
1312  * Callers must ensure proper synchronization of this function with power
1313  * management callbacks.
1314  */
1315 int acpi_dev_pm_attach(struct device *dev, bool power_on)
1316 {
1317         /*
1318          * Skip devices whose ACPI companions match the device IDs below,
1319          * because they require special power management handling incompatible
1320          * with the generic ACPI PM domain.
1321          */
1322         static const struct acpi_device_id special_pm_ids[] = {
1323                 {"PNP0C0B", }, /* Generic ACPI fan */
1324                 {"INT3404", }, /* Fan */
1325                 {}
1326         };
1327         struct acpi_device *adev = ACPI_COMPANION(dev);
1328 
1329         if (!adev || !acpi_match_device_ids(adev, special_pm_ids))
1330                 return 0;
1331 
1332         /*
1333          * Only attach the power domain to the first device if the
1334          * companion is shared by multiple. This is to prevent doing power
1335          * management twice.
1336          */
1337         if (!acpi_device_is_first_physical_node(adev, dev))
1338                 return 0;
1339 
1340         acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
1341         dev_pm_domain_set(dev, &acpi_general_pm_domain);
1342         if (power_on) {
1343                 acpi_dev_pm_full_power(adev);
1344                 acpi_device_wakeup_disable(adev);
1345         }
1346 
1347         dev->pm_domain->detach = acpi_dev_pm_detach;
1348         return 1;
1349 }
1350 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
1351 #endif /* CONFIG_PM */
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root/drivers/acpi/device_pm.c

DEFINITIONS
