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 * You should have received a copy of the GNU General Public License along 19 * with this program; if not, write to the Free Software Foundation, Inc., 20 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 21 * 22 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 23 */ 24 25 #include <linux/acpi.h> 26 #include <linux/export.h> 27 #include <linux/mutex.h> 28 #include <linux/pm_qos.h> 29 #include <linux/pm_runtime.h> 30 31 #include "internal.h" 32 33 #define _COMPONENT ACPI_POWER_COMPONENT 34 ACPI_MODULE_NAME("device_pm"); 35 36 /** 37 * acpi_power_state_string - String representation of ACPI device power state. 38 * @state: ACPI device power state to return the string representation of. 39 */ 40 const char *acpi_power_state_string(int state) 41 { 42 switch (state) { 43 case ACPI_STATE_D0: 44 return "D0"; 45 case ACPI_STATE_D1: 46 return "D1"; 47 case ACPI_STATE_D2: 48 return "D2"; 49 case ACPI_STATE_D3_HOT: 50 return "D3hot"; 51 case ACPI_STATE_D3_COLD: 52 return "D3cold"; 53 default: 54 return "(unknown)"; 55 } 56 } 57 58 /** 59 * acpi_device_get_power - Get power state of an ACPI device. 60 * @device: Device to get the power state of. 61 * @state: Place to store the power state of the device. 62 * 63 * This function does not update the device's power.state field, but it may 64 * update its parent's power.state field (when the parent's power state is 65 * unknown and the device's power state turns out to be D0). 66 */ 67 int acpi_device_get_power(struct acpi_device *device, int *state) 68 { 69 int result = ACPI_STATE_UNKNOWN; 70 71 if (!device || !state) 72 return -EINVAL; 73 74 if (!device->flags.power_manageable) { 75 /* TBD: Non-recursive algorithm for walking up hierarchy. */ 76 *state = device->parent ? 77 device->parent->power.state : ACPI_STATE_D0; 78 goto out; 79 } 80 81 /* 82 * Get the device's power state from power resources settings and _PSC, 83 * if available. 84 */ 85 if (device->power.flags.power_resources) { 86 int error = acpi_power_get_inferred_state(device, &result); 87 if (error) 88 return error; 89 } 90 if (device->power.flags.explicit_get) { 91 acpi_handle handle = device->handle; 92 unsigned long long psc; 93 acpi_status status; 94 95 status = acpi_evaluate_integer(handle, "_PSC", NULL, &psc); 96 if (ACPI_FAILURE(status)) 97 return -ENODEV; 98 99 /* 100 * The power resources settings may indicate a power state 101 * shallower than the actual power state of the device. 102 * 103 * Moreover, on systems predating ACPI 4.0, if the device 104 * doesn't depend on any power resources and _PSC returns 3, 105 * that means "power off". We need to maintain compatibility 106 * with those systems. 107 */ 108 if (psc > result && psc < ACPI_STATE_D3_COLD) 109 result = psc; 110 else if (result == ACPI_STATE_UNKNOWN) 111 result = psc > ACPI_STATE_D2 ? ACPI_STATE_D3_COLD : psc; 112 } 113 114 /* 115 * If we were unsure about the device parent's power state up to this 116 * point, the fact that the device is in D0 implies that the parent has 117 * to be in D0 too, except if ignore_parent is set. 118 */ 119 if (!device->power.flags.ignore_parent && device->parent 120 && device->parent->power.state == ACPI_STATE_UNKNOWN 121 && result == ACPI_STATE_D0) 122 device->parent->power.state = ACPI_STATE_D0; 123 124 *state = result; 125 126 out: 127 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] power state is %s\n", 128 device->pnp.bus_id, acpi_power_state_string(*state))); 129 130 return 0; 131 } 132 133 static int acpi_dev_pm_explicit_set(struct acpi_device *adev, int state) 134 { 135 if (adev->power.states[state].flags.explicit_set) { 136 char method[5] = { '_', 'P', 'S', '0' + state, '\0' }; 137 acpi_status status; 138 139 status = acpi_evaluate_object(adev->handle, method, NULL, NULL); 140 if (ACPI_FAILURE(status)) 141 return -ENODEV; 142 } 143 return 0; 144 } 145 146 /** 147 * acpi_device_set_power - Set power state of an ACPI device. 148 * @device: Device to set the power state of. 149 * @state: New power state to set. 150 * 151 * Callers must ensure that the device is power manageable before using this 152 * function. 153 */ 154 int acpi_device_set_power(struct acpi_device *device, int state) 155 { 156 int result = 0; 157 bool cut_power = false; 158 159 if (!device || !device->flags.power_manageable 160 || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD)) 161 return -EINVAL; 162 163 /* Make sure this is a valid target state */ 164 165 if (state == device->power.state) { 166 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device [%s] already in %s\n", 167 device->pnp.bus_id, 168 acpi_power_state_string(state))); 169 return 0; 170 } 171 172 if (!device->power.states[state].flags.valid) { 173 dev_warn(&device->dev, "Power state %s not supported\n", 174 acpi_power_state_string(state)); 175 return -ENODEV; 176 } 177 if (!device->power.flags.ignore_parent && 178 device->parent && (state < device->parent->power.state)) { 179 dev_warn(&device->dev, 180 "Cannot transition to power state %s for parent in %s\n", 181 acpi_power_state_string(state), 182 acpi_power_state_string(device->parent->power.state)); 183 return -ENODEV; 184 } 185 186 /* For D3cold we should first transition into D3hot. */ 187 if (state == ACPI_STATE_D3_COLD 188 && device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible) { 189 state = ACPI_STATE_D3_HOT; 190 cut_power = true; 191 } 192 193 if (state < device->power.state && state != ACPI_STATE_D0 194 && device->power.state >= ACPI_STATE_D3_HOT) { 195 dev_warn(&device->dev, 196 "Cannot transition to non-D0 state from D3\n"); 197 return -ENODEV; 198 } 199 200 /* 201 * Transition Power 202 * ---------------- 203 * In accordance with the ACPI specification first apply power (via 204 * power resources) and then evalute _PSx. 205 */ 206 if (device->power.flags.power_resources) { 207 result = acpi_power_transition(device, state); 208 if (result) 209 goto end; 210 } 211 result = acpi_dev_pm_explicit_set(device, state); 212 if (result) 213 goto end; 214 215 if (cut_power) { 216 device->power.state = state; 217 state = ACPI_STATE_D3_COLD; 218 result = acpi_power_transition(device, state); 219 } 220 221 end: 222 if (result) { 223 dev_warn(&device->dev, "Failed to change power state to %s\n", 224 acpi_power_state_string(state)); 225 } else { 226 device->power.state = state; 227 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 228 "Device [%s] transitioned to %s\n", 229 device->pnp.bus_id, 230 acpi_power_state_string(state))); 231 } 232 233 return result; 234 } 235 EXPORT_SYMBOL(acpi_device_set_power); 236 237 int acpi_bus_set_power(acpi_handle handle, int state) 238 { 239 struct acpi_device *device; 240 int result; 241 242 result = acpi_bus_get_device(handle, &device); 243 if (result) 244 return result; 245 246 return acpi_device_set_power(device, state); 247 } 248 EXPORT_SYMBOL(acpi_bus_set_power); 249 250 int acpi_bus_init_power(struct acpi_device *device) 251 { 252 int state; 253 int result; 254 255 if (!device) 256 return -EINVAL; 257 258 device->power.state = ACPI_STATE_UNKNOWN; 259 if (!acpi_device_is_present(device)) 260 return 0; 261 262 result = acpi_device_get_power(device, &state); 263 if (result) 264 return result; 265 266 if (state < ACPI_STATE_D3_COLD && device->power.flags.power_resources) { 267 result = acpi_power_on_resources(device, state); 268 if (result) 269 return result; 270 271 result = acpi_dev_pm_explicit_set(device, state); 272 if (result) 273 return result; 274 } else if (state == ACPI_STATE_UNKNOWN) { 275 /* 276 * No power resources and missing _PSC? Cross fingers and make 277 * it D0 in hope that this is what the BIOS put the device into. 278 * [We tried to force D0 here by executing _PS0, but that broke 279 * Toshiba P870-303 in a nasty way.] 280 */ 281 state = ACPI_STATE_D0; 282 } 283 device->power.state = state; 284 return 0; 285 } 286 287 /** 288 * acpi_device_fix_up_power - Force device with missing _PSC into D0. 289 * @device: Device object whose power state is to be fixed up. 290 * 291 * Devices without power resources and _PSC, but having _PS0 and _PS3 defined, 292 * are assumed to be put into D0 by the BIOS. However, in some cases that may 293 * not be the case and this function should be used then. 294 */ 295 int acpi_device_fix_up_power(struct acpi_device *device) 296 { 297 int ret = 0; 298 299 if (!device->power.flags.power_resources 300 && !device->power.flags.explicit_get 301 && device->power.state == ACPI_STATE_D0) 302 ret = acpi_dev_pm_explicit_set(device, ACPI_STATE_D0); 303 304 return ret; 305 } 306 307 int acpi_device_update_power(struct acpi_device *device, int *state_p) 308 { 309 int state; 310 int result; 311 312 if (device->power.state == ACPI_STATE_UNKNOWN) { 313 result = acpi_bus_init_power(device); 314 if (!result && state_p) 315 *state_p = device->power.state; 316 317 return result; 318 } 319 320 result = acpi_device_get_power(device, &state); 321 if (result) 322 return result; 323 324 if (state == ACPI_STATE_UNKNOWN) { 325 state = ACPI_STATE_D0; 326 result = acpi_device_set_power(device, state); 327 if (result) 328 return result; 329 } else { 330 if (device->power.flags.power_resources) { 331 /* 332 * We don't need to really switch the state, bu we need 333 * to update the power resources' reference counters. 334 */ 335 result = acpi_power_transition(device, state); 336 if (result) 337 return result; 338 } 339 device->power.state = state; 340 } 341 if (state_p) 342 *state_p = state; 343 344 return 0; 345 } 346 347 int acpi_bus_update_power(acpi_handle handle, int *state_p) 348 { 349 struct acpi_device *device; 350 int result; 351 352 result = acpi_bus_get_device(handle, &device); 353 return result ? result : acpi_device_update_power(device, state_p); 354 } 355 EXPORT_SYMBOL_GPL(acpi_bus_update_power); 356 357 bool acpi_bus_power_manageable(acpi_handle handle) 358 { 359 struct acpi_device *device; 360 int result; 361 362 result = acpi_bus_get_device(handle, &device); 363 return result ? false : device->flags.power_manageable; 364 } 365 EXPORT_SYMBOL(acpi_bus_power_manageable); 366 367 #ifdef CONFIG_PM 368 static DEFINE_MUTEX(acpi_pm_notifier_lock); 369 370 /** 371 * acpi_add_pm_notifier - Register PM notifier for given ACPI device. 372 * @adev: ACPI device to add the notifier for. 373 * @context: Context information to pass to the notifier routine. 374 * 375 * NOTE: @adev need not be a run-wake or wakeup device to be a valid source of 376 * PM wakeup events. For example, wakeup events may be generated for bridges 377 * if one of the devices below the bridge is signaling wakeup, even if the 378 * bridge itself doesn't have a wakeup GPE associated with it. 379 */ 380 acpi_status acpi_add_pm_notifier(struct acpi_device *adev, 381 acpi_notify_handler handler, void *context) 382 { 383 acpi_status status = AE_ALREADY_EXISTS; 384 385 mutex_lock(&acpi_pm_notifier_lock); 386 387 if (adev->wakeup.flags.notifier_present) 388 goto out; 389 390 status = acpi_install_notify_handler(adev->handle, 391 ACPI_SYSTEM_NOTIFY, 392 handler, context); 393 if (ACPI_FAILURE(status)) 394 goto out; 395 396 adev->wakeup.flags.notifier_present = true; 397 398 out: 399 mutex_unlock(&acpi_pm_notifier_lock); 400 return status; 401 } 402 403 /** 404 * acpi_remove_pm_notifier - Unregister PM notifier from given ACPI device. 405 * @adev: ACPI device to remove the notifier from. 406 */ 407 acpi_status acpi_remove_pm_notifier(struct acpi_device *adev, 408 acpi_notify_handler handler) 409 { 410 acpi_status status = AE_BAD_PARAMETER; 411 412 mutex_lock(&acpi_pm_notifier_lock); 413 414 if (!adev->wakeup.flags.notifier_present) 415 goto out; 416 417 status = acpi_remove_notify_handler(adev->handle, 418 ACPI_SYSTEM_NOTIFY, 419 handler); 420 if (ACPI_FAILURE(status)) 421 goto out; 422 423 adev->wakeup.flags.notifier_present = false; 424 425 out: 426 mutex_unlock(&acpi_pm_notifier_lock); 427 return status; 428 } 429 430 bool acpi_bus_can_wakeup(acpi_handle handle) 431 { 432 struct acpi_device *device; 433 int result; 434 435 result = acpi_bus_get_device(handle, &device); 436 return result ? false : device->wakeup.flags.valid; 437 } 438 EXPORT_SYMBOL(acpi_bus_can_wakeup); 439 440 /** 441 * acpi_dev_pm_get_state - Get preferred power state of ACPI device. 442 * @dev: Device whose preferred target power state to return. 443 * @adev: ACPI device node corresponding to @dev. 444 * @target_state: System state to match the resultant device state. 445 * @d_min_p: Location to store the highest power state available to the device. 446 * @d_max_p: Location to store the lowest power state available to the device. 447 * 448 * Find the lowest power (highest number) and highest power (lowest number) ACPI 449 * device power states that the device can be in while the system is in the 450 * state represented by @target_state. Store the integer numbers representing 451 * those stats in the memory locations pointed to by @d_max_p and @d_min_p, 452 * respectively. 453 * 454 * Callers must ensure that @dev and @adev are valid pointers and that @adev 455 * actually corresponds to @dev before using this function. 456 * 457 * Returns 0 on success or -ENODATA when one of the ACPI methods fails or 458 * returns a value that doesn't make sense. The memory locations pointed to by 459 * @d_max_p and @d_min_p are only modified on success. 460 */ 461 static int acpi_dev_pm_get_state(struct device *dev, struct acpi_device *adev, 462 u32 target_state, int *d_min_p, int *d_max_p) 463 { 464 char method[] = { '_', 'S', '0' + target_state, 'D', '\0' }; 465 acpi_handle handle = adev->handle; 466 unsigned long long ret; 467 int d_min, d_max; 468 bool wakeup = false; 469 acpi_status status; 470 471 /* 472 * If the system state is S0, the lowest power state the device can be 473 * in is D3cold, unless the device has _S0W and is supposed to signal 474 * wakeup, in which case the return value of _S0W has to be used as the 475 * lowest power state available to the device. 476 */ 477 d_min = ACPI_STATE_D0; 478 d_max = ACPI_STATE_D3_COLD; 479 480 /* 481 * If present, _SxD methods return the minimum D-state (highest power 482 * state) we can use for the corresponding S-states. Otherwise, the 483 * minimum D-state is D0 (ACPI 3.x). 484 */ 485 if (target_state > ACPI_STATE_S0) { 486 /* 487 * We rely on acpi_evaluate_integer() not clobbering the integer 488 * provided if AE_NOT_FOUND is returned. 489 */ 490 ret = d_min; 491 status = acpi_evaluate_integer(handle, method, NULL, &ret); 492 if ((ACPI_FAILURE(status) && status != AE_NOT_FOUND) 493 || ret > ACPI_STATE_D3_COLD) 494 return -ENODATA; 495 496 /* 497 * We need to handle legacy systems where D3hot and D3cold are 498 * the same and 3 is returned in both cases, so fall back to 499 * D3cold if D3hot is not a valid state. 500 */ 501 if (!adev->power.states[ret].flags.valid) { 502 if (ret == ACPI_STATE_D3_HOT) 503 ret = ACPI_STATE_D3_COLD; 504 else 505 return -ENODATA; 506 } 507 d_min = ret; 508 wakeup = device_may_wakeup(dev) && adev->wakeup.flags.valid 509 && adev->wakeup.sleep_state >= target_state; 510 } else if (dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) != 511 PM_QOS_FLAGS_NONE) { 512 wakeup = adev->wakeup.flags.valid; 513 } 514 515 /* 516 * If _PRW says we can wake up the system from the target sleep state, 517 * the D-state returned by _SxD is sufficient for that (we assume a 518 * wakeup-aware driver if wake is set). Still, if _SxW exists 519 * (ACPI 3.x), it should return the maximum (lowest power) D-state that 520 * can wake the system. _S0W may be valid, too. 521 */ 522 if (wakeup) { 523 method[3] = 'W'; 524 status = acpi_evaluate_integer(handle, method, NULL, &ret); 525 if (status == AE_NOT_FOUND) { 526 if (target_state > ACPI_STATE_S0) 527 d_max = d_min; 528 } else if (ACPI_SUCCESS(status) && ret <= ACPI_STATE_D3_COLD) { 529 /* Fall back to D3cold if ret is not a valid state. */ 530 if (!adev->power.states[ret].flags.valid) 531 ret = ACPI_STATE_D3_COLD; 532 533 d_max = ret > d_min ? ret : d_min; 534 } else { 535 return -ENODATA; 536 } 537 } 538 539 if (d_min_p) 540 *d_min_p = d_min; 541 542 if (d_max_p) 543 *d_max_p = d_max; 544 545 return 0; 546 } 547 548 /** 549 * acpi_pm_device_sleep_state - Get preferred power state of ACPI device. 550 * @dev: Device whose preferred target power state to return. 551 * @d_min_p: Location to store the upper limit of the allowed states range. 552 * @d_max_in: Deepest low-power state to take into consideration. 553 * Return value: Preferred power state of the device on success, -ENODEV 554 * if there's no 'struct acpi_device' for @dev, -EINVAL if @d_max_in is 555 * incorrect, or -ENODATA on ACPI method failure. 556 * 557 * The caller must ensure that @dev is valid before using this function. 558 */ 559 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in) 560 { 561 acpi_handle handle = ACPI_HANDLE(dev); 562 struct acpi_device *adev; 563 int ret, d_min, d_max; 564 565 if (d_max_in < ACPI_STATE_D0 || d_max_in > ACPI_STATE_D3_COLD) 566 return -EINVAL; 567 568 if (d_max_in > ACPI_STATE_D3_HOT) { 569 enum pm_qos_flags_status stat; 570 571 stat = dev_pm_qos_flags(dev, PM_QOS_FLAG_NO_POWER_OFF); 572 if (stat == PM_QOS_FLAGS_ALL) 573 d_max_in = ACPI_STATE_D3_HOT; 574 } 575 576 if (!handle || acpi_bus_get_device(handle, &adev)) { 577 dev_dbg(dev, "ACPI handle without context in %s!\n", __func__); 578 return -ENODEV; 579 } 580 581 ret = acpi_dev_pm_get_state(dev, adev, acpi_target_system_state(), 582 &d_min, &d_max); 583 if (ret) 584 return ret; 585 586 if (d_max_in < d_min) 587 return -EINVAL; 588 589 if (d_max > d_max_in) { 590 for (d_max = d_max_in; d_max > d_min; d_max--) { 591 if (adev->power.states[d_max].flags.valid) 592 break; 593 } 594 } 595 596 if (d_min_p) 597 *d_min_p = d_min; 598 599 return d_max; 600 } 601 EXPORT_SYMBOL(acpi_pm_device_sleep_state); 602 603 #ifdef CONFIG_PM_RUNTIME 604 /** 605 * acpi_wakeup_device - Wakeup notification handler for ACPI devices. 606 * @handle: ACPI handle of the device the notification is for. 607 * @event: Type of the signaled event. 608 * @context: Device corresponding to @handle. 609 */ 610 static void acpi_wakeup_device(acpi_handle handle, u32 event, void *context) 611 { 612 struct device *dev = context; 613 614 if (event == ACPI_NOTIFY_DEVICE_WAKE && dev) { 615 pm_wakeup_event(dev, 0); 616 pm_runtime_resume(dev); 617 } 618 } 619 620 /** 621 * __acpi_device_run_wake - Enable/disable runtime remote wakeup for device. 622 * @adev: ACPI device to enable/disable the remote wakeup for. 623 * @enable: Whether to enable or disable the wakeup functionality. 624 * 625 * Enable/disable the GPE associated with @adev so that it can generate 626 * wakeup signals for the device in response to external (remote) events and 627 * enable/disable device wakeup power. 628 * 629 * Callers must ensure that @adev is a valid ACPI device node before executing 630 * this function. 631 */ 632 int __acpi_device_run_wake(struct acpi_device *adev, bool enable) 633 { 634 struct acpi_device_wakeup *wakeup = &adev->wakeup; 635 636 if (enable) { 637 acpi_status res; 638 int error; 639 640 error = acpi_enable_wakeup_device_power(adev, ACPI_STATE_S0); 641 if (error) 642 return error; 643 644 res = acpi_enable_gpe(wakeup->gpe_device, wakeup->gpe_number); 645 if (ACPI_FAILURE(res)) { 646 acpi_disable_wakeup_device_power(adev); 647 return -EIO; 648 } 649 } else { 650 acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number); 651 acpi_disable_wakeup_device_power(adev); 652 } 653 return 0; 654 } 655 656 /** 657 * acpi_pm_device_run_wake - Enable/disable remote wakeup for given device. 658 * @dev: Device to enable/disable the platform to wake up. 659 * @enable: Whether to enable or disable the wakeup functionality. 660 */ 661 int acpi_pm_device_run_wake(struct device *phys_dev, bool enable) 662 { 663 struct acpi_device *adev; 664 acpi_handle handle; 665 666 if (!device_run_wake(phys_dev)) 667 return -EINVAL; 668 669 handle = ACPI_HANDLE(phys_dev); 670 if (!handle || acpi_bus_get_device(handle, &adev)) { 671 dev_dbg(phys_dev, "ACPI handle without context in %s!\n", 672 __func__); 673 return -ENODEV; 674 } 675 676 return __acpi_device_run_wake(adev, enable); 677 } 678 EXPORT_SYMBOL(acpi_pm_device_run_wake); 679 #else 680 static inline void acpi_wakeup_device(acpi_handle handle, u32 event, 681 void *context) {} 682 #endif /* CONFIG_PM_RUNTIME */ 683 684 #ifdef CONFIG_PM_SLEEP 685 /** 686 * __acpi_device_sleep_wake - Enable or disable device to wake up the system. 687 * @dev: Device to enable/desible to wake up the system. 688 * @target_state: System state the device is supposed to wake up from. 689 * @enable: Whether to enable or disable @dev to wake up the system. 690 */ 691 int __acpi_device_sleep_wake(struct acpi_device *adev, u32 target_state, 692 bool enable) 693 { 694 return enable ? 695 acpi_enable_wakeup_device_power(adev, target_state) : 696 acpi_disable_wakeup_device_power(adev); 697 } 698 699 /** 700 * acpi_pm_device_sleep_wake - Enable or disable device to wake up the system. 701 * @dev: Device to enable/desible to wake up the system from sleep states. 702 * @enable: Whether to enable or disable @dev to wake up the system. 703 */ 704 int acpi_pm_device_sleep_wake(struct device *dev, bool enable) 705 { 706 acpi_handle handle; 707 struct acpi_device *adev; 708 int error; 709 710 if (!device_can_wakeup(dev)) 711 return -EINVAL; 712 713 handle = ACPI_HANDLE(dev); 714 if (!handle || acpi_bus_get_device(handle, &adev)) { 715 dev_dbg(dev, "ACPI handle without context in %s!\n", __func__); 716 return -ENODEV; 717 } 718 719 error = __acpi_device_sleep_wake(adev, acpi_target_system_state(), 720 enable); 721 if (!error) 722 dev_info(dev, "System wakeup %s by ACPI\n", 723 enable ? "enabled" : "disabled"); 724 725 return error; 726 } 727 #endif /* CONFIG_PM_SLEEP */ 728 729 /** 730 * acpi_dev_pm_low_power - Put ACPI device into a low-power state. 731 * @dev: Device to put into a low-power state. 732 * @adev: ACPI device node corresponding to @dev. 733 * @system_state: System state to choose the device state for. 734 */ 735 static int acpi_dev_pm_low_power(struct device *dev, struct acpi_device *adev, 736 u32 system_state) 737 { 738 int ret, state; 739 740 if (!acpi_device_power_manageable(adev)) 741 return 0; 742 743 ret = acpi_dev_pm_get_state(dev, adev, system_state, NULL, &state); 744 return ret ? ret : acpi_device_set_power(adev, state); 745 } 746 747 /** 748 * acpi_dev_pm_full_power - Put ACPI device into the full-power state. 749 * @adev: ACPI device node to put into the full-power state. 750 */ 751 static int acpi_dev_pm_full_power(struct acpi_device *adev) 752 { 753 return acpi_device_power_manageable(adev) ? 754 acpi_device_set_power(adev, ACPI_STATE_D0) : 0; 755 } 756 757 #ifdef CONFIG_PM_RUNTIME 758 /** 759 * acpi_dev_runtime_suspend - Put device into a low-power state using ACPI. 760 * @dev: Device to put into a low-power state. 761 * 762 * Put the given device into a runtime low-power state using the standard ACPI 763 * mechanism. Set up remote wakeup if desired, choose the state to put the 764 * device into (this checks if remote wakeup is expected to work too), and set 765 * the power state of the device. 766 */ 767 int acpi_dev_runtime_suspend(struct device *dev) 768 { 769 struct acpi_device *adev = ACPI_COMPANION(dev); 770 bool remote_wakeup; 771 int error; 772 773 if (!adev) 774 return 0; 775 776 remote_wakeup = dev_pm_qos_flags(dev, PM_QOS_FLAG_REMOTE_WAKEUP) > 777 PM_QOS_FLAGS_NONE; 778 error = __acpi_device_run_wake(adev, remote_wakeup); 779 if (remote_wakeup && error) 780 return -EAGAIN; 781 782 error = acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0); 783 if (error) 784 __acpi_device_run_wake(adev, false); 785 786 return error; 787 } 788 EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend); 789 790 /** 791 * acpi_dev_runtime_resume - Put device into the full-power state using ACPI. 792 * @dev: Device to put into the full-power state. 793 * 794 * Put the given device into the full-power state using the standard ACPI 795 * mechanism at run time. Set the power state of the device to ACPI D0 and 796 * disable remote wakeup. 797 */ 798 int acpi_dev_runtime_resume(struct device *dev) 799 { 800 struct acpi_device *adev = ACPI_COMPANION(dev); 801 int error; 802 803 if (!adev) 804 return 0; 805 806 error = acpi_dev_pm_full_power(adev); 807 __acpi_device_run_wake(adev, false); 808 return error; 809 } 810 EXPORT_SYMBOL_GPL(acpi_dev_runtime_resume); 811 812 /** 813 * acpi_subsys_runtime_suspend - Suspend device using ACPI. 814 * @dev: Device to suspend. 815 * 816 * Carry out the generic runtime suspend procedure for @dev and use ACPI to put 817 * it into a runtime low-power state. 818 */ 819 int acpi_subsys_runtime_suspend(struct device *dev) 820 { 821 int ret = pm_generic_runtime_suspend(dev); 822 return ret ? ret : acpi_dev_runtime_suspend(dev); 823 } 824 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_suspend); 825 826 /** 827 * acpi_subsys_runtime_resume - Resume device using ACPI. 828 * @dev: Device to Resume. 829 * 830 * Use ACPI to put the given device into the full-power state and carry out the 831 * generic runtime resume procedure for it. 832 */ 833 int acpi_subsys_runtime_resume(struct device *dev) 834 { 835 int ret = acpi_dev_runtime_resume(dev); 836 return ret ? ret : pm_generic_runtime_resume(dev); 837 } 838 EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume); 839 #endif /* CONFIG_PM_RUNTIME */ 840 841 #ifdef CONFIG_PM_SLEEP 842 /** 843 * acpi_dev_suspend_late - Put device into a low-power state using ACPI. 844 * @dev: Device to put into a low-power state. 845 * 846 * Put the given device into a low-power state during system transition to a 847 * sleep state using the standard ACPI mechanism. Set up system wakeup if 848 * desired, choose the state to put the device into (this checks if system 849 * wakeup is expected to work too), and set the power state of the device. 850 */ 851 int acpi_dev_suspend_late(struct device *dev) 852 { 853 struct acpi_device *adev = ACPI_COMPANION(dev); 854 u32 target_state; 855 bool wakeup; 856 int error; 857 858 if (!adev) 859 return 0; 860 861 target_state = acpi_target_system_state(); 862 wakeup = device_may_wakeup(dev); 863 error = __acpi_device_sleep_wake(adev, target_state, wakeup); 864 if (wakeup && error) 865 return error; 866 867 error = acpi_dev_pm_low_power(dev, adev, target_state); 868 if (error) 869 __acpi_device_sleep_wake(adev, ACPI_STATE_UNKNOWN, false); 870 871 return error; 872 } 873 EXPORT_SYMBOL_GPL(acpi_dev_suspend_late); 874 875 /** 876 * acpi_dev_resume_early - Put device into the full-power state using ACPI. 877 * @dev: Device to put into the full-power state. 878 * 879 * Put the given device into the full-power state using the standard ACPI 880 * mechanism during system transition to the working state. Set the power 881 * state of the device to ACPI D0 and disable remote wakeup. 882 */ 883 int acpi_dev_resume_early(struct device *dev) 884 { 885 struct acpi_device *adev = ACPI_COMPANION(dev); 886 int error; 887 888 if (!adev) 889 return 0; 890 891 error = acpi_dev_pm_full_power(adev); 892 __acpi_device_sleep_wake(adev, ACPI_STATE_UNKNOWN, false); 893 return error; 894 } 895 EXPORT_SYMBOL_GPL(acpi_dev_resume_early); 896 897 /** 898 * acpi_subsys_prepare - Prepare device for system transition to a sleep state. 899 * @dev: Device to prepare. 900 */ 901 int acpi_subsys_prepare(struct device *dev) 902 { 903 /* 904 * Follow PCI and resume devices suspended at run time before running 905 * their system suspend callbacks. 906 */ 907 pm_runtime_resume(dev); 908 return pm_generic_prepare(dev); 909 } 910 EXPORT_SYMBOL_GPL(acpi_subsys_prepare); 911 912 /** 913 * acpi_subsys_suspend_late - Suspend device using ACPI. 914 * @dev: Device to suspend. 915 * 916 * Carry out the generic late suspend procedure for @dev and use ACPI to put 917 * it into a low-power state during system transition into a sleep state. 918 */ 919 int acpi_subsys_suspend_late(struct device *dev) 920 { 921 int ret = pm_generic_suspend_late(dev); 922 return ret ? ret : acpi_dev_suspend_late(dev); 923 } 924 EXPORT_SYMBOL_GPL(acpi_subsys_suspend_late); 925 926 /** 927 * acpi_subsys_resume_early - Resume device using ACPI. 928 * @dev: Device to Resume. 929 * 930 * Use ACPI to put the given device into the full-power state and carry out the 931 * generic early resume procedure for it during system transition into the 932 * working state. 933 */ 934 int acpi_subsys_resume_early(struct device *dev) 935 { 936 int ret = acpi_dev_resume_early(dev); 937 return ret ? ret : pm_generic_resume_early(dev); 938 } 939 EXPORT_SYMBOL_GPL(acpi_subsys_resume_early); 940 #endif /* CONFIG_PM_SLEEP */ 941 942 static struct dev_pm_domain acpi_general_pm_domain = { 943 .ops = { 944 #ifdef CONFIG_PM_RUNTIME 945 .runtime_suspend = acpi_subsys_runtime_suspend, 946 .runtime_resume = acpi_subsys_runtime_resume, 947 #endif 948 #ifdef CONFIG_PM_SLEEP 949 .prepare = acpi_subsys_prepare, 950 .suspend_late = acpi_subsys_suspend_late, 951 .resume_early = acpi_subsys_resume_early, 952 .poweroff_late = acpi_subsys_suspend_late, 953 .restore_early = acpi_subsys_resume_early, 954 #endif 955 }, 956 }; 957 958 /** 959 * acpi_dev_pm_attach - Prepare device for ACPI power management. 960 * @dev: Device to prepare. 961 * @power_on: Whether or not to power on the device. 962 * 963 * If @dev has a valid ACPI handle that has a valid struct acpi_device object 964 * attached to it, install a wakeup notification handler for the device and 965 * add it to the general ACPI PM domain. If @power_on is set, the device will 966 * be put into the ACPI D0 state before the function returns. 967 * 968 * This assumes that the @dev's bus type uses generic power management callbacks 969 * (or doesn't use any power management callbacks at all). 970 * 971 * Callers must ensure proper synchronization of this function with power 972 * management callbacks. 973 */ 974 int acpi_dev_pm_attach(struct device *dev, bool power_on) 975 { 976 struct acpi_device *adev = ACPI_COMPANION(dev); 977 978 if (!adev) 979 return -ENODEV; 980 981 if (dev->pm_domain) 982 return -EEXIST; 983 984 acpi_add_pm_notifier(adev, acpi_wakeup_device, dev); 985 dev->pm_domain = &acpi_general_pm_domain; 986 if (power_on) { 987 acpi_dev_pm_full_power(adev); 988 __acpi_device_run_wake(adev, false); 989 } 990 return 0; 991 } 992 EXPORT_SYMBOL_GPL(acpi_dev_pm_attach); 993 994 /** 995 * acpi_dev_pm_detach - Remove ACPI power management from the device. 996 * @dev: Device to take care of. 997 * @power_off: Whether or not to try to remove power from the device. 998 * 999 * Remove the device from the general ACPI PM domain and remove its wakeup 1000 * notifier. If @power_off is set, additionally remove power from the device if 1001 * possible. 1002 * 1003 * Callers must ensure proper synchronization of this function with power 1004 * management callbacks. 1005 */ 1006 void acpi_dev_pm_detach(struct device *dev, bool power_off) 1007 { 1008 struct acpi_device *adev = ACPI_COMPANION(dev); 1009 1010 if (adev && dev->pm_domain == &acpi_general_pm_domain) { 1011 dev->pm_domain = NULL; 1012 acpi_remove_pm_notifier(adev, acpi_wakeup_device); 1013 if (power_off) { 1014 /* 1015 * If the device's PM QoS resume latency limit or flags 1016 * have been exposed to user space, they have to be 1017 * hidden at this point, so that they don't affect the 1018 * choice of the low-power state to put the device into. 1019 */ 1020 dev_pm_qos_hide_latency_limit(dev); 1021 dev_pm_qos_hide_flags(dev); 1022 __acpi_device_run_wake(adev, false); 1023 acpi_dev_pm_low_power(dev, adev, ACPI_STATE_S0); 1024 } 1025 } 1026 } 1027 EXPORT_SYMBOL_GPL(acpi_dev_pm_detach); 1028 #endif /* CONFIG_PM */ 1029