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