1 /* 2 * drivers/acpi/device_pm.c - ACPI device power management routines. 3 * 4 * Copyright (C) 2012, Intel Corp. 5 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 6 * 7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License version 2 as published 11 * by the Free Software Foundation. 12 * 13 * This program is distributed in the hope that it will be useful, but 14 * WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * General Public License for more details. 17 * 18 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 19 */ 20 21 #include <linux/acpi.h> 22 #include <linux/export.h> 23 #include <linux/mutex.h> 24 #include <linux/pm_qos.h> 25 #include <linux/pm_domain.h> 26 #include <linux/pm_runtime.h> 27 #include <linux/suspend.h> 28 29 #include "internal.h" 30 31 #define _COMPONENT ACPI_POWER_COMPONENT 32 ACPI_MODULE_NAME("device_pm"); 33 34 /** 35 * acpi_power_state_string - String representation of ACPI device power state. 36 * @state: ACPI device power state to return the string representation of. 37 */ 38 const char *acpi_power_state_string(int state) 39 { 40 switch (state) { 41 case ACPI_STATE_D0: 42 return "D0"; 43 case ACPI_STATE_D1: 44 return "D1"; 45 case ACPI_STATE_D2: 46 return "D2"; 47 case ACPI_STATE_D3_HOT: 48 return "D3hot"; 49 case ACPI_STATE_D3_COLD: 50 return "D3cold"; 51 default: 52 return "(unknown)"; 53 } 54 } 55 56 /** 57 * acpi_device_get_power - Get power state of an ACPI device. 58 * @device: Device to get the power state of. 59 * @state: Place to store the power state of the device. 60 * 61 * This function does not update the device's power.state field, but it may 62 * update its parent's power.state field (when the parent's power state is 63 * unknown and the device's power state turns out to be D0). 64 */ 65 int acpi_device_get_power(struct acpi_device *device, int *state) 66 { 67 int result = ACPI_STATE_UNKNOWN; 68 69 if (!device || !state) 70 return -EINVAL; 71 72 if (!device->flags.power_manageable) { 73 /* TBD: Non-recursive algorithm for walking up hierarchy. */ 74 *state = device->parent ? 75 device->parent->power.state : ACPI_STATE_D0; 76 goto out; 77 } 78 79 /* 80 * Get the device's power state from power resources settings and _PSC, 81 * if available. 82 */ 83 if (device->power.flags.power_resources) { 84 int error = acpi_power_get_inferred_state(device, &result); 85 if (error) 86 return error; 87 } 88 if (device->power.flags.explicit_get) { 89 acpi_handle handle = device->handle; 90 unsigned long long psc; 91 acpi_status status; 92 93 status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc); 94 if (ACPI_FAILURE(status)) 95 return -ENODEV; 96 97 /* 98 * The power resources settings may indicate a power state 99 * shallower than the actual power state of the device, because 100 * the same power resources may be referenced by other devices. 101 * 102 * For systems predating ACPI 4.0 we assume that D3hot is the 103 * deepest state that can be supported. 104 */ 105 if (psc > result && psc < ACPI_STATE_D3_COLD) 106 result = psc; 107 else if (result == ACPI_STATE_UNKNOWN) 108 result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_HOT : psc; 109 } 110 111 /* 112 * If we were unsure about the device parent's power state up to this 113 * point, the fact that the device is in D0 implies that the parent has 114 * to be in D0 too, except if ignore_parent is set. 115 */ 116 if (!device->power.flags.ignore_parent && device->parent 117 && device->parent->power.state == ACPI_STATE_UNKNOWN 118 && result == ACPI_STATE_D0) 119 device->parent->power.state = ACPI_STATE_D0; 120 121 *state = result; 122 123 out: 124 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n", 125 device->pnp.bus_id, acpi_power_state_string(*state))); 126 127 return 0; 128 } 129 EXPORT_SYMBOL(acpi_device_get_power); 130 131 static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state) 132 { 133 if (adev->power.states[state].flags.explicit_set) { 134 char method[5] = { '_', 'P', 'S', '0' + state, '\0' }; 135 acpi_status status; 136 137 status = acpi_evaluate_object(adev->handle, method, NULL, NULL); 138 if (ACPI_FAILURE(status)) 139 return -ENODEV; 140 } 141 return 0; 142 } 143 144 /** 145 * acpi_device_set_power - Set power state of an ACPI device. 146 * @device: Device to set the power state of. 147 * @state: New power state to set. 148 * 149 * Callers must ensure that the device is power manageable before using this 150 * function. 151 */ 152 int acpi_device_set_power(struct acpi_device *device, int state) 153 { 154 int target_state = state; 155 int result = 0; 156 157 if (!device || !device->flags.power_manageable 158 || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD)) 159 return -EINVAL; 160 161 /* Make sure this is a valid target state */ 162 163 if (state == device->power.state) { 164 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n", 165 device->pnp.bus_id, 166 acpi_power_state_string(state))); 167 return 0; 168 } 169 170 if (state == ACPI_STATE_D3_COLD) { 171 /* 172 * For transitions to D3cold we need to execute _PS3 and then 173 * possibly drop references to the power resources in use. 174 */ 175 state = ACPI_STATE_D3_HOT; 176 /* If _PR3 is not available, use D3hot as the target state. */ 177 if (!device->power.states[ACPI_STATE_D3_COLD].flags.valid) 178 target_state = state; 179 } else if (!device->power.states[state].flags.valid) { 180 dev_warn(&device->dev, "Power state %s not supported\n", 181 acpi_power_state_string(state)); 182 return -ENODEV; 183 } 184 185 if (!device->power.flags.ignore_parent && 186 device->parent && (state < device->parent->power.state)) { 187 dev_warn(&device->dev, 188 "Cannot transition to power state %s for parent in %s\n", 189 acpi_power_state_string(state), 190 acpi_power_state_string(device->parent->power.state)); 191 return -ENODEV; 192 } 193 194 /* 195 * Transition Power 196 * ---------------- 197 * In accordance with ACPI 6, _PSx is executed before manipulating power 198 * resources, unless the target state is D0, in which case _PS0 is 199 * supposed to be executed after turning the power resources on. 200 */ 201 if (state > ACPI_STATE_D0) { 202 /* 203 * According to ACPI 6, devices cannot go from lower-power 204 * (deeper) states to higher-power (shallower) states. 205 */ 206 if (state < device->power.state) { 207 dev_warn(&device->dev, "Cannot transition from %s to %s\n", 208 acpi_power_state_string(device->power.state), 209 acpi_power_state_string(state)); 210 return -ENODEV; 211 } 212 213 result = acpi_dev_pm_explicit_set(device, state); 214 if (result) 215 goto end; 216 217 if (device->power.flags.power_resources) 218 result = acpi_power_transition(device, target_state); 219 } else { 220 if (device->power.flags.power_resources) { 221 result = acpi_power_transition(device, ACPI_STATE_D0); 222 if (result) 223 goto end; 224 } 225 result = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0); 226 } 227 228 end: 229 if (result) { 230 dev_warn(&device->dev, "Failed to change power state to %s\n", 231 acpi_power_state_string(state)); 232 } else { 233 device->power.state = target_state; 234 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 235 "Device [%s] transitioned to %s\n", 236 device->pnp.bus_id, 237 acpi_power_state_string(state))); 238 } 239 240 return result; 241 } 242 EXPORT_SYMBOL(acpi_device_set_power); 243 244 int acpi_bus_set_power(acpi_handle handle, int state) 245 { 246 struct acpi_device *device; 247 int result; 248 249 result = acpi_bus_get_device(handle, &device); 250 if (result) 251 return result; 252 253 return acpi_device_set_power(device, state); 254 } 255 EXPORT_SYMBOL(acpi_bus_set_power); 256 257 int acpi_bus_init_power(struct acpi_device *device) 258 { 259 int state; 260 int result; 261 262 if (!device) 263 return -EINVAL; 264 265 device->power.state = ACPI_STATE_UNKNOWN; 266 if (!acpi_device_is_present(device)) { 267 device->flags.initialized = false; 268 return -ENXIO; 269 } 270 271 result = acpi_device_get_power(device, &state); 272 if (result) 273 return result; 274 275 if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) { 276 /* Reference count the power resources. */ 277 result = acpi_power_on_resources(device, state); 278 if (result) 279 return result; 280 281 if (state == ACPI_STATE_D0) { 282 /* 283 * If _PSC is not present and the state inferred from 284 * power resources appears to be D0, it still may be 285 * necessary to execute _PS0 at this point, because 286 * another device using the same power resources may 287 * have been put into D0 previously and that's why we 288 * see D0 here. 289 */ 290 result = acpi_dev_pm_explicit_set(device, state); 291 if (result) 292 return result; 293 } 294 } else if (state == ACPI_STATE_UNKNOWN) { 295 /* 296 * No power resources and missing _PSC? Cross fingers and make 297 * it D0 in hope that this is what the BIOS put the device into. 298 * [We tried to force D0 here by executing _PS0, but that broke 299 * Toshiba P870-303 in a nasty way.] 300 */ 301 state = ACPI_STATE_D0; 302 } 303 device->power.state = state; 304 return 0; 305 } 306 307 /** 308 * acpi_device_fix_up_power - Force device with missing _PSC into D0. 309 * @device: Device object whose power state is to be fixed up. 310 * 311 * Devices without power resources and _PSC, but having _PS0 and _PS3 defined, 312 * are assumed to be put into D0 by the BIOS. However, in some cases that may 313 * not be the case and this function should be used then. 314 */ 315 int acpi_device_fix_up_power(struct acpi_device *device) 316 { 317 int ret = 0; 318 319 if (!device->power.flags.power_resources 320 && !device->power.flags.explicit_get 321 && device->power.state == ACPI_STATE_D0) 322 ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0); 323 324 return ret; 325 } 326 EXPORT_SYMBOL_GPL(acpi_device_fix_up_power); 327 328 int acpi_device_update_power(struct acpi_device *device, int *state_p) 329 { 330 int state; 331 int result; 332 333 if (device->power.state == ACPI_STATE_UNKNOWN) { 334 result = acpi_bus_init_power(device); 335 if (!result && state_p) 336 *state_p = device->power.state; 337 338 return result; 339 } 340 341 result = acpi_device_get_power(device, &state); 342 if (result) 343 return result; 344 345 if (state == ACPI_STATE_UNKNOWN) { 346 state = ACPI_STATE_D0; 347 result = acpi_device_set_power(device, state); 348 if (result) 349 return result; 350 } else { 351 if (device->power.flags.power_resources) { 352 /* 353 * We don't need to really switch the state, bu we need 354 * to update the power resources' reference counters. 355 */ 356 result = acpi_power_transition(device, state); 357 if (result) 358 return result; 359 } 360 device->power.state = state; 361 } 362 if (state_p) 363 *state_p = state; 364 365 return 0; 366 } 367 EXPORT_SYMBOL_GPL(acpi_device_update_power); 368 369 int acpi_bus_update_power(acpi_handle handle, int *state_p) 370 { 371 struct acpi_device *device; 372 int result; 373 374 result = acpi_bus_get_device(handle, &device); 375 return result ? result : acpi_device_update_power(device, state_p); 376 } 377 EXPORT_SYMBOL_GPL(acpi_bus_update_power); 378 379 bool acpi_bus_power_manageable(acpi_handle handle) 380 { 381 struct acpi_device *device; 382 int result; 383 384 result = acpi_bus_get_device(handle, &device); 385 return result ? false : device->flags.power_manageable; 386 } 387 EXPORT_SYMBOL(acpi_bus_power_manageable); 388 389 #ifdef CONFIG_PM 390 static DEFINE_MUTEX(acpi_pm_notifier_lock); 391 static DEFINE_MUTEX(acpi_pm_notifier_install_lock); 392 393 void acpi_pm_wakeup_event(struct device *dev) 394 { 395 pm_wakeup_dev_event(dev, 0, acpi_s2idle_wakeup()); 396 } 397 EXPORT_SYMBOL_GPL(acpi_pm_wakeup_event); 398 399 static void acpi_pm_notify_handler(acpi_handle handle, u32 val, void *not_used) 400 { 401 struct acpi_device *adev; 402 403 if (val != ACPI_NOTIFY_DEVICE_WAKE) 404 return; 405 406 acpi_handle_debug(handle, "Wake notify\n"); 407 408 adev = acpi_bus_get_acpi_device(handle); 409 if (!adev) 410 return; 411 412 mutex_lock(&acpi_pm_notifier_lock); 413 414 if (adev->wakeup.flags.notifier_present) { 415 pm_wakeup_ws_event(adev->wakeup.ws, 0, acpi_s2idle_wakeup()); 416 if (adev->wakeup.context.func) { 417 acpi_handle_debug(handle, "Running %pS for %s\n", 418 adev->wakeup.context.func, 419 dev_name(adev->wakeup.context.dev)); 420 adev->wakeup.context.func(&adev->wakeup.context); 421 } 422 } 423 424 mutex_unlock(&acpi_pm_notifier_lock); 425 426 acpi_bus_put_acpi_device(adev); 427 } 428 429 /** 430 * acpi_add_pm_notifier - Register PM notify handler for given ACPI device. 431 * @adev: ACPI device to add the notify handler for. 432 * @dev: Device to generate a wakeup event for while handling the notification. 433 * @func: Work function to execute when handling the notification. 434 * 435 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of 436 * PM wakeup events. For example, wakeup events may be generated for bridges 437 * if one of the devices below the bridge is signaling wakeup, even if the 438 * bridge itself doesn't have a wakeup GPE associated with it. 439 */ 440 acpi_status acpi_add_pm_notifier(struct acpi_device *adev, struct device *dev, 441 void (*func)(struct acpi_device_wakeup_context *context)) 442 { 443 acpi_status status = AE_ALREADY_EXISTS; 444 445 if (!dev && !func) 446 return AE_BAD_PARAMETER; 447 448 mutex_lock(&acpi_pm_notifier_install_lock); 449 450 if (adev->wakeup.flags.notifier_present) 451 goto out; 452 453 status = acpi_install_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY, 454 acpi_pm_notify_handler, NULL); 455 if (ACPI_FAILURE(status)) 456 goto out; 457 458 mutex_lock(&acpi_pm_notifier_lock); 459 adev->wakeup.ws = wakeup_source_register(dev_name(&adev->dev)); 460 adev->wakeup.context.dev = dev; 461 adev->wakeup.context.func = func; 462 adev->wakeup.flags.notifier_present = true; 463 mutex_unlock(&acpi_pm_notifier_lock); 464 465 out: 466 mutex_unlock(&acpi_pm_notifier_install_lock); 467 return status; 468 } 469 470 /** 471 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device. 472 * @adev: ACPI device to remove the notifier from. 473 */ 474 acpi_status acpi_remove_pm_notifier(struct acpi_device *adev) 475 { 476 acpi_status status = AE_BAD_PARAMETER; 477 478 mutex_lock(&acpi_pm_notifier_install_lock); 479 480 if (!adev->wakeup.flags.notifier_present) 481 goto out; 482 483 status = acpi_remove_notify_handler(adev->handle, 484 ACPI_SYSTEM_NOTIFY, 485 acpi_pm_notify_handler); 486 if (ACPI_FAILURE(status)) 487 goto out; 488 489 mutex_lock(&acpi_pm_notifier_lock); 490 adev->wakeup.context.func = NULL; 491 adev->wakeup.context.dev = NULL; 492 wakeup_source_unregister(adev->wakeup.ws); 493 adev->wakeup.flags.notifier_present = false; 494 mutex_unlock(&acpi_pm_notifier_lock); 495 496 out: 497 mutex_unlock(&acpi_pm_notifier_install_lock); 498 return status; 499 } 500 501 bool acpi_bus_can_wakeup(acpi_handle handle) 502 { 503 struct acpi_device *device; 504 int result; 505 506 result = acpi_bus_get_device(handle, &device); 507 return result ? false : device->wakeup.flags.valid; 508 } 509 EXPORT_SYMBOL(acpi_bus_can_wakeup); 510 511 bool acpi_pm_device_can_wakeup(struct device *dev) 512 { 513 struct acpi_device *adev = ACPI_COMPANION(dev); 514 515 return adev ? acpi_device_can_wakeup(adev) : false; 516 } 517 518 /** 519 * acpi_dev_pm_get_state - Get preferred power state of ACPI device. 520 * @dev: Device whose preferred target power state to return. 521 * @adev: ACPI device node corresponding to @dev. 522 * @target_state: System state to match the resultant device state. 523 * @d_min_p: Location to store the highest power state available to the device. 524 * @d_max_p: Location to store the lowest power state available to the device. 525 * 526 * Find the lowest power (highest number) and highest power (lowest number) ACPI 527 * device power states that the device can be in while the system is in the 528 * state represented by @target_state. Store the integer numbers representing 529 * those stats in the memory locations pointed to by @d_max_p and @d_min_p, 530 * respectively. 531 * 532 * Callers must ensure that @dev and @adev are valid pointers and that @adev 533 * actually corresponds to @dev before using this function. 534 * 535 * Returns 0 on success or -ENODATA when one of the ACPI methods fails or 536 * returns a value that doesn't make sense. The memory locations pointed to by 537 * @d_max_p and @d_min_p are only modified on success. 538 */ 539 static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev, 540 u32 target_state, int *d_min_p, int *d_max_p) 541 { 542 char method[] = { '_', 'S', '0' + target_state, 'D', '\0' }; 543 acpi_handle handle = adev->handle; 544 unsigned long long ret; 545 int d_min, d_max; 546 bool wakeup = false; 547 bool has_sxd = false; 548 acpi_status status; 549 550 /* 551 * If the system state is S0, the lowest power state the device can be 552 * in is D3cold, unless the device has _S0W and is supposed to signal 553 * wakeup, in which case the return value of _S0W has to be used as the 554 * lowest power state available to the device. 555 */ 556 d_min = ACPI_STATE_D0; 557 d_max = ACPI_STATE_D3_COLD; 558 559 /* 560 * If present, _SxD methods return the minimum D-state (highest power 561 * state) we can use for the corresponding S-states. Otherwise, the 562 * minimum D-state is D0 (ACPI 3.x). 563 */ 564 if (target_state > ACPI_STATE_S0) { 565 /* 566 * We rely on acpi_evaluate_integer() not clobbering the integer 567 * provided if AE_NOT_FOUND is returned. 568 */ 569 ret = d_min; 570 status = acpi_evaluate_integer(handle, method, NULL, &ret); 571 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND) 572 || ret > ACPI_STATE_D3_COLD) 573 return -ENODATA; 574 575 /* 576 * We need to handle legacy systems where D3hot and D3cold are 577 * the same and 3 is returned in both cases, so fall back to 578 * D3cold if D3hot is not a valid state. 579 */ 580 if (!adev->power.states[ret].flags.valid) { 581 if (ret == ACPI_STATE_D3_HOT) 582 ret = ACPI_STATE_D3_COLD; 583 else 584 return -ENODATA; 585 } 586 587 if (status == AE_OK) 588 has_sxd = true; 589 590 d_min = ret; 591 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid 592 && adev->wakeup.sleep_state >= target_state; 593 } else { 594 wakeup = adev->wakeup.flags.valid; 595 } 596 597 /* 598 * If _PRW says we can wake up the system from the target sleep state, 599 * the D-state returned by _SxD is sufficient for that (we assume a 600 * wakeup-aware driver if wake is set). Still, if _SxW exists 601 * (ACPI 3.x), it should return the maximum (lowest power) D-state that 602 * can wake the system. _S0W may be valid, too. 603 */ 604 if (wakeup) { 605 method[3] = 'W'; 606 status = acpi_evaluate_integer(handle, method, NULL, &ret); 607 if (status == AE_NOT_FOUND) { 608 /* No _SxW. In this case, the ACPI spec says that we 609 * must not go into any power state deeper than the 610 * value returned from _SxD. 611 */ 612 if (has_sxd && target_state > ACPI_STATE_S0) 613 d_max = d_min; 614 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) { 615 /* Fall back to D3cold if ret is not a valid state. */ 616 if (!adev->power.states[ret].flags.valid) 617 ret = ACPI_STATE_D3_COLD; 618 619 d_max = ret > d_min ? ret : d_min; 620 } else { 621 return -ENODATA; 622 } 623 } 624 625 if (d_min_p) 626 *d_min_p = d_min; 627 628 if (d_max_p) 629 *d_max_p = d_max; 630 631 return 0; 632 } 633 634 /** 635 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device. 636 * @dev: Device whose preferred target power state to return. 637 * @d_min_p: Location to store the upper limit of the allowed states range. 638 * @d_max_in: Deepest low-power state to take into consideration. 639 * Return value: Preferred power state of the device on success, -ENODEV 640 * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is 641 * incorrect, or -ENODATA on ACPI method failure. 642 * 643 * The caller must ensure that @dev is valid before using this function. 644 */ 645 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in) 646 { 647 struct acpi_device *adev; 648 int ret, d_min, d_max; 649 650 if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD) 651 return -EINVAL; 652 653 if (d_max_in > ACPI_STATE_D2) { 654 enum pm_qos_flags_status stat; 655 656 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF); 657 if (stat == PM_QOS_FLAGS_ALL) 658 d_max_in = ACPI_STATE_D2; 659 } 660 661 adev = ACPI_COMPANION(dev); 662 if (!adev) { 663 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__); 664 return -ENODEV; 665 } 666 667 ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(), 668 &d_min, &d_max); 669 if (ret) 670 return ret; 671 672 if (d_max_in < d_min) 673 return -EINVAL; 674 675 if (d_max > d_max_in) { 676 for (d_max = d_max_in; d_max > d_min; d_max--) { 677 if (adev->power.states[d_max].flags.valid) 678 break; 679 } 680 } 681 682 if (d_min_p) 683 *d_min_p = d_min; 684 685 return d_max; 686 } 687 EXPORT_SYMBOL(acpi_pm_device_sleep_state); 688 689 /** 690 * acpi_pm_notify_work_func - ACPI devices wakeup notification work function. 691 * @context: Device wakeup context. 692 */ 693 static void acpi_pm_notify_work_func(struct acpi_device_wakeup_context *context) 694 { 695 struct device *dev = context->dev; 696 697 if (dev) { 698 pm_wakeup_event(dev, 0); 699 pm_request_resume(dev); 700 } 701 } 702 703 static DEFINE_MUTEX(acpi_wakeup_lock); 704 705 static int __acpi_device_wakeup_enable(struct acpi_device *adev, 706 u32 target_state, int max_count) 707 { 708 struct acpi_device_wakeup *wakeup = &adev->wakeup; 709 acpi_status status; 710 int error = 0; 711 712 mutex_lock(&acpi_wakeup_lock); 713 714 if (wakeup->enable_count >= max_count) 715 goto out; 716 717 if (wakeup->enable_count > 0) 718 goto inc; 719 720 error = acpi_enable_wakeup_device_power(adev, target_state); 721 if (error) 722 goto out; 723 724 status = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number); 725 if (ACPI_FAILURE(status)) { 726 acpi_disable_wakeup_device_power(adev); 727 error = -EIO; 728 goto out; 729 } 730 731 acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n", 732 (unsigned int)wakeup->gpe_number); 733 734 inc: 735 wakeup->enable_count++; 736 737 out: 738 mutex_unlock(&acpi_wakeup_lock); 739 return error; 740 } 741 742 /** 743 * acpi_device_wakeup_enable - Enable wakeup functionality for device. 744 * @adev: ACPI device to enable wakeup functionality for. 745 * @target_state: State the system is transitioning into. 746 * 747 * Enable the GPE associated with @adev so that it can generate wakeup signals 748 * for the device in response to external (remote) events and enable wakeup 749 * power for it. 750 * 751 * Callers must ensure that @adev is a valid ACPI device node before executing 752 * this function. 753 */ 754 static int acpi_device_wakeup_enable(struct acpi_device *adev, u32 target_state) 755 { 756 return __acpi_device_wakeup_enable(adev, target_state, 1); 757 } 758 759 /** 760 * acpi_device_wakeup_disable - Disable wakeup functionality for device. 761 * @adev: ACPI device to disable wakeup functionality for. 762 * 763 * Disable the GPE associated with @adev and disable wakeup power for it. 764 * 765 * Callers must ensure that @adev is a valid ACPI device node before executing 766 * this function. 767 */ 768 static void acpi_device_wakeup_disable(struct acpi_device *adev) 769 { 770 struct acpi_device_wakeup *wakeup = &adev->wakeup; 771 772 mutex_lock(&acpi_wakeup_lock); 773 774 if (!wakeup->enable_count) 775 goto out; 776 777 acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number); 778 acpi_disable_wakeup_device_power(adev); 779 780 wakeup->enable_count--; 781 782 out: 783 mutex_unlock(&acpi_wakeup_lock); 784 } 785 786 static int __acpi_pm_set_device_wakeup(struct device *dev, bool enable, 787 int max_count) 788 { 789 struct acpi_device *adev; 790 int error; 791 792 adev = ACPI_COMPANION(dev); 793 if (!adev) { 794 dev_dbg(dev, "ACPI companion missing in %s!\n", __func__); 795 return -ENODEV; 796 } 797 798 if (!acpi_device_can_wakeup(adev)) 799 return -EINVAL; 800 801 if (!enable) { 802 acpi_device_wakeup_disable(adev); 803 dev_dbg(dev, "Wakeup disabled by ACPI\n"); 804 return 0; 805 } 806 807 error = __acpi_device_wakeup_enable(adev, acpi_target_system_state(), 808 max_count); 809 if (!error) 810 dev_dbg(dev, "Wakeup enabled by ACPI\n"); 811 812 return error; 813 } 814 815 /** 816 * acpi_pm_set_device_wakeup - Enable/disable remote wakeup for given device. 817 * @dev: Device to enable/disable to generate wakeup events. 818 * @enable: Whether to enable or disable the wakeup functionality. 819 */ 820 int acpi_pm_set_device_wakeup(struct device *dev, bool enable) 821 { 822 return __acpi_pm_set_device_wakeup(dev, enable, 1); 823 } 824 EXPORT_SYMBOL_GPL(acpi_pm_set_device_wakeup); 825 826 /** 827 * acpi_pm_set_bridge_wakeup - Enable/disable remote wakeup for given bridge. 828 * @dev: Bridge device to enable/disable to generate wakeup events. 829 * @enable: Whether to enable or disable the wakeup functionality. 830 */ 831 int acpi_pm_set_bridge_wakeup(struct device *dev, bool enable) 832 { 833 return __acpi_pm_set_device_wakeup(dev, enable, INT_MAX); 834 } 835 EXPORT_SYMBOL_GPL(acpi_pm_set_bridge_wakeup); 836 837 /** 838 * acpi_dev_pm_low_power - Put ACPI device into a low-power state. 839 * @dev: Device to put into a low-power state. 840 * @adev: ACPI device node corresponding to @dev. 841 * @system_state: System state to choose the device state for. 842 */ 843 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev, 844 u32 system_state) 845 { 846 int ret, state; 847 848 if (!acpi_device_power_manageable(adev)) 849 return 0; 850 851 ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state); 852 return ret ? ret : acpi_device_set_power(adev, state); 853 } 854 855 /** 856 * acpi_dev_pm_full_power - Put ACPI device into the full-power state. 857 * @adev: ACPI device node to put into the full-power state. 858 */ 859 static int acpi_dev_pm_full_power(struct acpi_device *adev) 860 { 861 return acpi_device_power_manageable(adev) ? 862 acpi_device_set_power(adev, ACPI_STATE_D0) : 0; 863 } 864 865 /** 866 * acpi_dev_suspend - Put device into a low-power state using ACPI. 867 * @dev: Device to put into a low-power state. 868 * @wakeup: Whether or not to enable wakeup for the device. 869 * 870 * Put the given device into a low-power state using the standard ACPI 871 * mechanism. Set up remote wakeup if desired, choose the state to put the 872 * device into (this checks if remote wakeup is expected to work too), and set 873 * the power state of the device. 874 */ 875 int acpi_dev_suspend(struct device *dev, bool wakeup) 876 { 877 struct acpi_device *adev = ACPI_COMPANION(dev); 878 u32 target_state = acpi_target_system_state(); 879 int error; 880 881 if (!adev) 882 return 0; 883 884 if (wakeup && acpi_device_can_wakeup(adev)) { 885 error = acpi_device_wakeup_enable(adev, target_state); 886 if (error) 887 return -EAGAIN; 888 } else { 889 wakeup = false; 890 } 891 892 error = acpi_dev_pm_low_power(dev, adev, target_state); 893 if (error && wakeup) 894 acpi_device_wakeup_disable(adev); 895 896 return error; 897 } 898 EXPORT_SYMBOL_GPL(acpi_dev_suspend); 899 900 /** 901 * acpi_dev_resume - Put device into the full-power state using ACPI. 902 * @dev: Device to put into the full-power state. 903 * 904 * Put the given device into the full-power state using the standard ACPI 905 * mechanism. Set the power state of the device to ACPI D0 and disable wakeup. 906 */ 907 int acpi_dev_resume(struct device *dev) 908 { 909 struct acpi_device *adev = ACPI_COMPANION(dev); 910 int error; 911 912 if (!adev) 913 return 0; 914 915 error = acpi_dev_pm_full_power(adev); 916 acpi_device_wakeup_disable(adev); 917 return error; 918 } 919 EXPORT_SYMBOL_GPL(acpi_dev_resume); 920 921 /** 922 * acpi_subsys_runtime_suspend - Suspend device using ACPI. 923 * @dev: Device to suspend. 924 * 925 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put 926 * it into a runtime low-power state. 927 */ 928 int acpi_subsys_runtime_suspend(struct device *dev) 929 { 930 int ret = pm_generic_runtime_suspend(dev); 931 return ret ? ret : acpi_dev_suspend(dev, true); 932 } 933 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend); 934 935 /** 936 * acpi_subsys_runtime_resume - Resume device using ACPI. 937 * @dev: Device to Resume. 938 * 939 * Use ACPI to put the given device into the full-power state and carry out the 940 * generic runtime resume procedure for it. 941 */ 942 int acpi_subsys_runtime_resume(struct device *dev) 943 { 944 int ret = acpi_dev_resume(dev); 945 return ret ? ret : pm_generic_runtime_resume(dev); 946 } 947 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume); 948 949 #ifdef CONFIG_PM_SLEEP 950 static bool acpi_dev_needs_resume(struct device *dev, struct acpi_device *adev) 951 { 952 u32 sys_target = acpi_target_system_state(); 953 int ret, state; 954 955 if (!pm_runtime_suspended(dev) || !adev || 956 device_may_wakeup(dev) != !!adev->wakeup.prepare_count) 957 return true; 958 959 if (sys_target == ACPI_STATE_S0) 960 return false; 961 962 if (adev->power.flags.dsw_present) 963 return true; 964 965 ret = acpi_dev_pm_get_state(dev, adev, sys_target, NULL, &state); 966 if (ret) 967 return true; 968 969 return state != adev->power.state; 970 } 971 972 /** 973 * acpi_subsys_prepare - Prepare device for system transition to a sleep state. 974 * @dev: Device to prepare. 975 */ 976 int acpi_subsys_prepare(struct device *dev) 977 { 978 struct acpi_device *adev = ACPI_COMPANION(dev); 979 980 if (dev->driver && dev->driver->pm && dev->driver->pm->prepare) { 981 int ret = dev->driver->pm->prepare(dev); 982 983 if (ret < 0) 984 return ret; 985 986 if (!ret && dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_PREPARE)) 987 return 0; 988 } 989 990 return !acpi_dev_needs_resume(dev, adev); 991 } 992 EXPORT_SYMBOL_GPL(acpi_subsys_prepare); 993 994 /** 995 * acpi_subsys_complete - Finalize device's resume during system resume. 996 * @dev: Device to handle. 997 */ 998 void acpi_subsys_complete(struct device *dev) 999 { 1000 pm_generic_complete(dev); 1001 /* 1002 * If the device had been runtime-suspended before the system went into 1003 * the sleep state it is going out of and it has never been resumed till 1004 * now, resume it in case the firmware powered it up. 1005 */ 1006 if (pm_runtime_suspended(dev) && pm_resume_via_firmware()) 1007 pm_request_resume(dev); 1008 } 1009 EXPORT_SYMBOL_GPL(acpi_subsys_complete); 1010 1011 /** 1012 * acpi_subsys_suspend - Run the device driver's suspend callback. 1013 * @dev: Device to handle. 1014 * 1015 * Follow PCI and resume devices from runtime suspend before running their 1016 * system suspend callbacks, unless the driver can cope with runtime-suspended 1017 * devices during system suspend and there are no ACPI-specific reasons for 1018 * resuming them. 1019 */ 1020 int acpi_subsys_suspend(struct device *dev) 1021 { 1022 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) || 1023 acpi_dev_needs_resume(dev, ACPI_COMPANION(dev))) 1024 pm_runtime_resume(dev); 1025 1026 return pm_generic_suspend(dev); 1027 } 1028 EXPORT_SYMBOL_GPL(acpi_subsys_suspend); 1029 1030 /** 1031 * acpi_subsys_suspend_late - Suspend device using ACPI. 1032 * @dev: Device to suspend. 1033 * 1034 * Carry out the generic late suspend procedure for @dev and use ACPI to put 1035 * it into a low-power state during system transition into a sleep state. 1036 */ 1037 int acpi_subsys_suspend_late(struct device *dev) 1038 { 1039 int ret; 1040 1041 if (dev_pm_smart_suspend_and_suspended(dev)) 1042 return 0; 1043 1044 ret = pm_generic_suspend_late(dev); 1045 return ret ? ret : acpi_dev_suspend(dev, device_may_wakeup(dev)); 1046 } 1047 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late); 1048 1049 /** 1050 * acpi_subsys_suspend_noirq - Run the device driver's "noirq" suspend callback. 1051 * @dev: Device to suspend. 1052 */ 1053 int acpi_subsys_suspend_noirq(struct device *dev) 1054 { 1055 int ret; 1056 1057 if (dev_pm_smart_suspend_and_suspended(dev)) { 1058 dev->power.may_skip_resume = true; 1059 return 0; 1060 } 1061 1062 ret = pm_generic_suspend_noirq(dev); 1063 if (ret) 1064 return ret; 1065 1066 /* 1067 * If the target system sleep state is suspend-to-idle, it is sufficient 1068 * to check whether or not the device's wakeup settings are good for 1069 * runtime PM. Otherwise, the pm_resume_via_firmware() check will cause 1070 * acpi_subsys_complete() to take care of fixing up the device's state 1071 * anyway, if need be. 1072 */ 1073 dev->power.may_skip_resume = device_may_wakeup(dev) || 1074 !device_can_wakeup(dev); 1075 1076 return 0; 1077 } 1078 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_noirq); 1079 1080 /** 1081 * acpi_subsys_resume_noirq - Run the device driver's "noirq" resume callback. 1082 * @dev: Device to handle. 1083 */ 1084 int acpi_subsys_resume_noirq(struct device *dev) 1085 { 1086 if (dev_pm_may_skip_resume(dev)) 1087 return 0; 1088 1089 /* 1090 * Devices with DPM_FLAG_SMART_SUSPEND may be left in runtime suspend 1091 * during system suspend, so update their runtime PM status to "active" 1092 * as they will be put into D0 going forward. 1093 */ 1094 if (dev_pm_smart_suspend_and_suspended(dev)) 1095 pm_runtime_set_active(dev); 1096 1097 return pm_generic_resume_noirq(dev); 1098 } 1099 EXPORT_SYMBOL_GPL(acpi_subsys_resume_noirq); 1100 1101 /** 1102 * acpi_subsys_resume_early - Resume device using ACPI. 1103 * @dev: Device to Resume. 1104 * 1105 * Use ACPI to put the given device into the full-power state and carry out the 1106 * generic early resume procedure for it during system transition into the 1107 * working state. 1108 */ 1109 int acpi_subsys_resume_early(struct device *dev) 1110 { 1111 int ret = acpi_dev_resume(dev); 1112 return ret ? ret : pm_generic_resume_early(dev); 1113 } 1114 EXPORT_SYMBOL_GPL(acpi_subsys_resume_early); 1115 1116 /** 1117 * acpi_subsys_freeze - Run the device driver's freeze callback. 1118 * @dev: Device to handle. 1119 */ 1120 int acpi_subsys_freeze(struct device *dev) 1121 { 1122 /* 1123 * This used to be done in acpi_subsys_prepare() for all devices and 1124 * some drivers may depend on it, so do it here. Ideally, however, 1125 * runtime-suspended devices should not be touched during freeze/thaw 1126 * transitions. 1127 */ 1128 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND)) 1129 pm_runtime_resume(dev); 1130 1131 return pm_generic_freeze(dev); 1132 } 1133 EXPORT_SYMBOL_GPL(acpi_subsys_freeze); 1134 1135 /** 1136 * acpi_subsys_freeze_late - Run the device driver's "late" freeze callback. 1137 * @dev: Device to handle. 1138 */ 1139 int acpi_subsys_freeze_late(struct device *dev) 1140 { 1141 1142 if (dev_pm_smart_suspend_and_suspended(dev)) 1143 return 0; 1144 1145 return pm_generic_freeze_late(dev); 1146 } 1147 EXPORT_SYMBOL_GPL(acpi_subsys_freeze_late); 1148 1149 /** 1150 * acpi_subsys_freeze_noirq - Run the device driver's "noirq" freeze callback. 1151 * @dev: Device to handle. 1152 */ 1153 int acpi_subsys_freeze_noirq(struct device *dev) 1154 { 1155 1156 if (dev_pm_smart_suspend_and_suspended(dev)) 1157 return 0; 1158 1159 return pm_generic_freeze_noirq(dev); 1160 } 1161 EXPORT_SYMBOL_GPL(acpi_subsys_freeze_noirq); 1162 1163 /** 1164 * acpi_subsys_thaw_noirq - Run the device driver's "noirq" thaw callback. 1165 * @dev: Device to handle. 1166 */ 1167 int acpi_subsys_thaw_noirq(struct device *dev) 1168 { 1169 /* 1170 * If the device is in runtime suspend, the "thaw" code may not work 1171 * correctly with it, so skip the driver callback and make the PM core 1172 * skip all of the subsequent "thaw" callbacks for the device. 1173 */ 1174 if (dev_pm_smart_suspend_and_suspended(dev)) { 1175 dev_pm_skip_next_resume_phases(dev); 1176 return 0; 1177 } 1178 1179 return pm_generic_thaw_noirq(dev); 1180 } 1181 EXPORT_SYMBOL_GPL(acpi_subsys_thaw_noirq); 1182 #endif /* CONFIG_PM_SLEEP */ 1183 1184 static struct dev_pm_domain acpi_general_pm_domain = { 1185 .ops = { 1186 .runtime_suspend = acpi_subsys_runtime_suspend, 1187 .runtime_resume = acpi_subsys_runtime_resume, 1188 #ifdef CONFIG_PM_SLEEP 1189 .prepare = acpi_subsys_prepare, 1190 .complete = acpi_subsys_complete, 1191 .suspend = acpi_subsys_suspend, 1192 .suspend_late = acpi_subsys_suspend_late, 1193 .suspend_noirq = acpi_subsys_suspend_noirq, 1194 .resume_noirq = acpi_subsys_resume_noirq, 1195 .resume_early = acpi_subsys_resume_early, 1196 .freeze = acpi_subsys_freeze, 1197 .freeze_late = acpi_subsys_freeze_late, 1198 .freeze_noirq = acpi_subsys_freeze_noirq, 1199 .thaw_noirq = acpi_subsys_thaw_noirq, 1200 .poweroff = acpi_subsys_suspend, 1201 .poweroff_late = acpi_subsys_suspend_late, 1202 .poweroff_noirq = acpi_subsys_suspend_noirq, 1203 .restore_noirq = acpi_subsys_resume_noirq, 1204 .restore_early = acpi_subsys_resume_early, 1205 #endif 1206 }, 1207 }; 1208 1209 /** 1210 * acpi_dev_pm_detach - Remove ACPI power management from the device. 1211 * @dev: Device to take care of. 1212 * @power_off: Whether or not to try to remove power from the device. 1213 * 1214 * Remove the device from the general ACPI PM domain and remove its wakeup 1215 * notifier. If @power_off is set, additionally remove power from the device if 1216 * possible. 1217 * 1218 * Callers must ensure proper synchronization of this function with power 1219 * management callbacks. 1220 */ 1221 static void acpi_dev_pm_detach(struct device *dev, bool power_off) 1222 { 1223 struct acpi_device *adev = ACPI_COMPANION(dev); 1224 1225 if (adev && dev->pm_domain == &acpi_general_pm_domain) { 1226 dev_pm_domain_set(dev, NULL); 1227 acpi_remove_pm_notifier(adev); 1228 if (power_off) { 1229 /* 1230 * If the device's PM QoS resume latency limit or flags 1231 * have been exposed to user space, they have to be 1232 * hidden at this point, so that they don't affect the 1233 * choice of the low-power state to put the device into. 1234 */ 1235 dev_pm_qos_hide_latency_limit(dev); 1236 dev_pm_qos_hide_flags(dev); 1237 acpi_device_wakeup_disable(adev); 1238 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0); 1239 } 1240 } 1241 } 1242 1243 /** 1244 * acpi_dev_pm_attach - Prepare device for ACPI power management. 1245 * @dev: Device to prepare. 1246 * @power_on: Whether or not to power on the device. 1247 * 1248 * If @dev has a valid ACPI handle that has a valid struct acpi_device object 1249 * attached to it, install a wakeup notification handler for the device and 1250 * add it to the general ACPI PM domain. If @power_on is set, the device will 1251 * be put into the ACPI D0 state before the function returns. 1252 * 1253 * This assumes that the @dev's bus type uses generic power management callbacks 1254 * (or doesn't use any power management callbacks at all). 1255 * 1256 * Callers must ensure proper synchronization of this function with power 1257 * management callbacks. 1258 */ 1259 int acpi_dev_pm_attach(struct device *dev, bool power_on) 1260 { 1261 struct acpi_device *adev = ACPI_COMPANION(dev); 1262 1263 if (!adev) 1264 return 0; 1265 1266 /* 1267 * Only attach the power domain to the first device if the 1268 * companion is shared by multiple. This is to prevent doing power 1269 * management twice. 1270 */ 1271 if (!acpi_device_is_first_physical_node(adev, dev)) 1272 return 0; 1273 1274 acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func); 1275 dev_pm_domain_set(dev, &acpi_general_pm_domain); 1276 if (power_on) { 1277 acpi_dev_pm_full_power(adev); 1278 acpi_device_wakeup_disable(adev); 1279 } 1280 1281 dev->pm_domain->detach = acpi_dev_pm_detach; 1282 return 1; 1283 } 1284 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach); 1285 #endif /* CONFIG_PM */ 1286