1 /* 2 * drivers/base/power/domain.c - Common code related to device power domains. 3 * 4 * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp. 5 * 6 * This file is released under the GPLv2. 7 */ 8 9 #include <linux/init.h> 10 #include <linux/kernel.h> 11 #include <linux/io.h> 12 #include <linux/pm_runtime.h> 13 #include <linux/pm_domain.h> 14 #include <linux/slab.h> 15 #include <linux/err.h> 16 #include <linux/sched.h> 17 #include <linux/suspend.h> 18 19 static LIST_HEAD(gpd_list); 20 static DEFINE_MUTEX(gpd_list_lock); 21 22 #ifdef CONFIG_PM 23 24 static struct generic_pm_domain *dev_to_genpd(struct device *dev) 25 { 26 if (IS_ERR_OR_NULL(dev->pm_domain)) 27 return ERR_PTR(-EINVAL); 28 29 return pd_to_genpd(dev->pm_domain); 30 } 31 32 static void genpd_sd_counter_dec(struct generic_pm_domain *genpd) 33 { 34 if (!WARN_ON(genpd->sd_count == 0)) 35 genpd->sd_count--; 36 } 37 38 static void genpd_acquire_lock(struct generic_pm_domain *genpd) 39 { 40 DEFINE_WAIT(wait); 41 42 mutex_lock(&genpd->lock); 43 /* 44 * Wait for the domain to transition into either the active, 45 * or the power off state. 46 */ 47 for (;;) { 48 prepare_to_wait(&genpd->status_wait_queue, &wait, 49 TASK_UNINTERRUPTIBLE); 50 if (genpd->status == GPD_STATE_ACTIVE 51 || genpd->status == GPD_STATE_POWER_OFF) 52 break; 53 mutex_unlock(&genpd->lock); 54 55 schedule(); 56 57 mutex_lock(&genpd->lock); 58 } 59 finish_wait(&genpd->status_wait_queue, &wait); 60 } 61 62 static void genpd_release_lock(struct generic_pm_domain *genpd) 63 { 64 mutex_unlock(&genpd->lock); 65 } 66 67 static void genpd_set_active(struct generic_pm_domain *genpd) 68 { 69 if (genpd->resume_count == 0) 70 genpd->status = GPD_STATE_ACTIVE; 71 } 72 73 /** 74 * pm_genpd_poweron - Restore power to a given PM domain and its parents. 75 * @genpd: PM domain to power up. 76 * 77 * Restore power to @genpd and all of its parents so that it is possible to 78 * resume a device belonging to it. 79 */ 80 int pm_genpd_poweron(struct generic_pm_domain *genpd) 81 { 82 struct generic_pm_domain *parent = genpd->parent; 83 int ret = 0; 84 85 start: 86 if (parent) { 87 genpd_acquire_lock(parent); 88 mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); 89 } else { 90 mutex_lock(&genpd->lock); 91 } 92 93 if (genpd->status == GPD_STATE_ACTIVE 94 || (genpd->prepared_count > 0 && genpd->suspend_power_off)) 95 goto out; 96 97 if (genpd->status != GPD_STATE_POWER_OFF) { 98 genpd_set_active(genpd); 99 goto out; 100 } 101 102 if (parent && parent->status != GPD_STATE_ACTIVE) { 103 mutex_unlock(&genpd->lock); 104 genpd_release_lock(parent); 105 106 ret = pm_genpd_poweron(parent); 107 if (ret) 108 return ret; 109 110 goto start; 111 } 112 113 if (genpd->power_on) { 114 ret = genpd->power_on(genpd); 115 if (ret) 116 goto out; 117 } 118 119 genpd_set_active(genpd); 120 if (parent) 121 parent->sd_count++; 122 123 out: 124 mutex_unlock(&genpd->lock); 125 if (parent) 126 genpd_release_lock(parent); 127 128 return ret; 129 } 130 131 #endif /* CONFIG_PM */ 132 133 #ifdef CONFIG_PM_RUNTIME 134 135 /** 136 * __pm_genpd_save_device - Save the pre-suspend state of a device. 137 * @dle: Device list entry of the device to save the state of. 138 * @genpd: PM domain the device belongs to. 139 */ 140 static int __pm_genpd_save_device(struct dev_list_entry *dle, 141 struct generic_pm_domain *genpd) 142 __releases(&genpd->lock) __acquires(&genpd->lock) 143 { 144 struct device *dev = dle->dev; 145 struct device_driver *drv = dev->driver; 146 int ret = 0; 147 148 if (dle->need_restore) 149 return 0; 150 151 mutex_unlock(&genpd->lock); 152 153 if (drv && drv->pm && drv->pm->runtime_suspend) { 154 if (genpd->start_device) 155 genpd->start_device(dev); 156 157 ret = drv->pm->runtime_suspend(dev); 158 159 if (genpd->stop_device) 160 genpd->stop_device(dev); 161 } 162 163 mutex_lock(&genpd->lock); 164 165 if (!ret) 166 dle->need_restore = true; 167 168 return ret; 169 } 170 171 /** 172 * __pm_genpd_restore_device - Restore the pre-suspend state of a device. 173 * @dle: Device list entry of the device to restore the state of. 174 * @genpd: PM domain the device belongs to. 175 */ 176 static void __pm_genpd_restore_device(struct dev_list_entry *dle, 177 struct generic_pm_domain *genpd) 178 __releases(&genpd->lock) __acquires(&genpd->lock) 179 { 180 struct device *dev = dle->dev; 181 struct device_driver *drv = dev->driver; 182 183 if (!dle->need_restore) 184 return; 185 186 mutex_unlock(&genpd->lock); 187 188 if (drv && drv->pm && drv->pm->runtime_resume) { 189 if (genpd->start_device) 190 genpd->start_device(dev); 191 192 drv->pm->runtime_resume(dev); 193 194 if (genpd->stop_device) 195 genpd->stop_device(dev); 196 } 197 198 mutex_lock(&genpd->lock); 199 200 dle->need_restore = false; 201 } 202 203 /** 204 * genpd_abort_poweroff - Check if a PM domain power off should be aborted. 205 * @genpd: PM domain to check. 206 * 207 * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during 208 * a "power off" operation, which means that a "power on" has occured in the 209 * meantime, or if its resume_count field is different from zero, which means 210 * that one of its devices has been resumed in the meantime. 211 */ 212 static bool genpd_abort_poweroff(struct generic_pm_domain *genpd) 213 { 214 return genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0; 215 } 216 217 /** 218 * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff(). 219 * @genpd: PM domait to power off. 220 * 221 * Queue up the execution of pm_genpd_poweroff() unless it's already been done 222 * before. 223 */ 224 void genpd_queue_power_off_work(struct generic_pm_domain *genpd) 225 { 226 if (!work_pending(&genpd->power_off_work)) 227 queue_work(pm_wq, &genpd->power_off_work); 228 } 229 230 /** 231 * pm_genpd_poweroff - Remove power from a given PM domain. 232 * @genpd: PM domain to power down. 233 * 234 * If all of the @genpd's devices have been suspended and all of its subdomains 235 * have been powered down, run the runtime suspend callbacks provided by all of 236 * the @genpd's devices' drivers and remove power from @genpd. 237 */ 238 static int pm_genpd_poweroff(struct generic_pm_domain *genpd) 239 __releases(&genpd->lock) __acquires(&genpd->lock) 240 { 241 struct generic_pm_domain *parent; 242 struct dev_list_entry *dle; 243 unsigned int not_suspended; 244 int ret = 0; 245 246 start: 247 /* 248 * Do not try to power off the domain in the following situations: 249 * (1) The domain is already in the "power off" state. 250 * (2) System suspend is in progress. 251 * (3) One of the domain's devices is being resumed right now. 252 */ 253 if (genpd->status == GPD_STATE_POWER_OFF || genpd->prepared_count > 0 254 || genpd->resume_count > 0) 255 return 0; 256 257 if (genpd->sd_count > 0) 258 return -EBUSY; 259 260 not_suspended = 0; 261 list_for_each_entry(dle, &genpd->dev_list, node) 262 if (dle->dev->driver && !pm_runtime_suspended(dle->dev)) 263 not_suspended++; 264 265 if (not_suspended > genpd->in_progress) 266 return -EBUSY; 267 268 if (genpd->poweroff_task) { 269 /* 270 * Another instance of pm_genpd_poweroff() is executing 271 * callbacks, so tell it to start over and return. 272 */ 273 genpd->status = GPD_STATE_REPEAT; 274 return 0; 275 } 276 277 if (genpd->gov && genpd->gov->power_down_ok) { 278 if (!genpd->gov->power_down_ok(&genpd->domain)) 279 return -EAGAIN; 280 } 281 282 genpd->status = GPD_STATE_BUSY; 283 genpd->poweroff_task = current; 284 285 list_for_each_entry_reverse(dle, &genpd->dev_list, node) { 286 ret = __pm_genpd_save_device(dle, genpd); 287 if (ret) { 288 genpd_set_active(genpd); 289 goto out; 290 } 291 292 if (genpd_abort_poweroff(genpd)) 293 goto out; 294 295 if (genpd->status == GPD_STATE_REPEAT) { 296 genpd->poweroff_task = NULL; 297 goto start; 298 } 299 } 300 301 parent = genpd->parent; 302 if (parent) { 303 mutex_unlock(&genpd->lock); 304 305 genpd_acquire_lock(parent); 306 mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING); 307 308 if (genpd_abort_poweroff(genpd)) { 309 genpd_release_lock(parent); 310 goto out; 311 } 312 } 313 314 if (genpd->power_off) { 315 ret = genpd->power_off(genpd); 316 if (ret == -EBUSY) { 317 genpd_set_active(genpd); 318 if (parent) 319 genpd_release_lock(parent); 320 321 goto out; 322 } 323 } 324 325 genpd->status = GPD_STATE_POWER_OFF; 326 327 if (parent) { 328 genpd_sd_counter_dec(parent); 329 if (parent->sd_count == 0) 330 genpd_queue_power_off_work(parent); 331 332 genpd_release_lock(parent); 333 } 334 335 out: 336 genpd->poweroff_task = NULL; 337 wake_up_all(&genpd->status_wait_queue); 338 return ret; 339 } 340 341 /** 342 * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0. 343 * @work: Work structure used for scheduling the execution of this function. 344 */ 345 static void genpd_power_off_work_fn(struct work_struct *work) 346 { 347 struct generic_pm_domain *genpd; 348 349 genpd = container_of(work, struct generic_pm_domain, power_off_work); 350 351 genpd_acquire_lock(genpd); 352 pm_genpd_poweroff(genpd); 353 genpd_release_lock(genpd); 354 } 355 356 /** 357 * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain. 358 * @dev: Device to suspend. 359 * 360 * Carry out a runtime suspend of a device under the assumption that its 361 * pm_domain field points to the domain member of an object of type 362 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 363 */ 364 static int pm_genpd_runtime_suspend(struct device *dev) 365 { 366 struct generic_pm_domain *genpd; 367 368 dev_dbg(dev, "%s()\n", __func__); 369 370 genpd = dev_to_genpd(dev); 371 if (IS_ERR(genpd)) 372 return -EINVAL; 373 374 if (genpd->stop_device) { 375 int ret = genpd->stop_device(dev); 376 if (ret) 377 return ret; 378 } 379 380 mutex_lock(&genpd->lock); 381 genpd->in_progress++; 382 pm_genpd_poweroff(genpd); 383 genpd->in_progress--; 384 mutex_unlock(&genpd->lock); 385 386 return 0; 387 } 388 389 /** 390 * __pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain. 391 * @dev: Device to resume. 392 * @genpd: PM domain the device belongs to. 393 */ 394 static void __pm_genpd_runtime_resume(struct device *dev, 395 struct generic_pm_domain *genpd) 396 { 397 struct dev_list_entry *dle; 398 399 list_for_each_entry(dle, &genpd->dev_list, node) { 400 if (dle->dev == dev) { 401 __pm_genpd_restore_device(dle, genpd); 402 break; 403 } 404 } 405 } 406 407 /** 408 * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain. 409 * @dev: Device to resume. 410 * 411 * Carry out a runtime resume of a device under the assumption that its 412 * pm_domain field points to the domain member of an object of type 413 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 414 */ 415 static int pm_genpd_runtime_resume(struct device *dev) 416 { 417 struct generic_pm_domain *genpd; 418 DEFINE_WAIT(wait); 419 int ret; 420 421 dev_dbg(dev, "%s()\n", __func__); 422 423 genpd = dev_to_genpd(dev); 424 if (IS_ERR(genpd)) 425 return -EINVAL; 426 427 ret = pm_genpd_poweron(genpd); 428 if (ret) 429 return ret; 430 431 mutex_lock(&genpd->lock); 432 genpd->status = GPD_STATE_BUSY; 433 genpd->resume_count++; 434 for (;;) { 435 prepare_to_wait(&genpd->status_wait_queue, &wait, 436 TASK_UNINTERRUPTIBLE); 437 /* 438 * If current is the powering off task, we have been called 439 * reentrantly from one of the device callbacks, so we should 440 * not wait. 441 */ 442 if (!genpd->poweroff_task || genpd->poweroff_task == current) 443 break; 444 mutex_unlock(&genpd->lock); 445 446 schedule(); 447 448 mutex_lock(&genpd->lock); 449 } 450 finish_wait(&genpd->status_wait_queue, &wait); 451 __pm_genpd_runtime_resume(dev, genpd); 452 genpd->resume_count--; 453 genpd_set_active(genpd); 454 wake_up_all(&genpd->status_wait_queue); 455 mutex_unlock(&genpd->lock); 456 457 if (genpd->start_device) 458 genpd->start_device(dev); 459 460 return 0; 461 } 462 463 #else 464 465 static inline void genpd_power_off_work_fn(struct work_struct *work) {} 466 static inline void __pm_genpd_runtime_resume(struct device *dev, 467 struct generic_pm_domain *genpd) {} 468 469 #define pm_genpd_runtime_suspend NULL 470 #define pm_genpd_runtime_resume NULL 471 472 #endif /* CONFIG_PM_RUNTIME */ 473 474 #ifdef CONFIG_PM_SLEEP 475 476 /** 477 * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its parents. 478 * @genpd: PM domain to power off, if possible. 479 * 480 * Check if the given PM domain can be powered off (during system suspend or 481 * hibernation) and do that if so. Also, in that case propagate to its parent. 482 * 483 * This function is only called in "noirq" stages of system power transitions, 484 * so it need not acquire locks (all of the "noirq" callbacks are executed 485 * sequentially, so it is guaranteed that it will never run twice in parallel). 486 */ 487 static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd) 488 { 489 struct generic_pm_domain *parent = genpd->parent; 490 491 if (genpd->status == GPD_STATE_POWER_OFF) 492 return; 493 494 if (genpd->suspended_count != genpd->device_count || genpd->sd_count > 0) 495 return; 496 497 if (genpd->power_off) 498 genpd->power_off(genpd); 499 500 genpd->status = GPD_STATE_POWER_OFF; 501 if (parent) { 502 genpd_sd_counter_dec(parent); 503 pm_genpd_sync_poweroff(parent); 504 } 505 } 506 507 /** 508 * resume_needed - Check whether to resume a device before system suspend. 509 * @dev: Device to check. 510 * @genpd: PM domain the device belongs to. 511 * 512 * There are two cases in which a device that can wake up the system from sleep 513 * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled 514 * to wake up the system and it has to remain active for this purpose while the 515 * system is in the sleep state and (2) if the device is not enabled to wake up 516 * the system from sleep states and it generally doesn't generate wakeup signals 517 * by itself (those signals are generated on its behalf by other parts of the 518 * system). In the latter case it may be necessary to reconfigure the device's 519 * wakeup settings during system suspend, because it may have been set up to 520 * signal remote wakeup from the system's working state as needed by runtime PM. 521 * Return 'true' in either of the above cases. 522 */ 523 static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd) 524 { 525 bool active_wakeup; 526 527 if (!device_can_wakeup(dev)) 528 return false; 529 530 active_wakeup = genpd->active_wakeup && genpd->active_wakeup(dev); 531 return device_may_wakeup(dev) ? active_wakeup : !active_wakeup; 532 } 533 534 /** 535 * pm_genpd_prepare - Start power transition of a device in a PM domain. 536 * @dev: Device to start the transition of. 537 * 538 * Start a power transition of a device (during a system-wide power transition) 539 * under the assumption that its pm_domain field points to the domain member of 540 * an object of type struct generic_pm_domain representing a PM domain 541 * consisting of I/O devices. 542 */ 543 static int pm_genpd_prepare(struct device *dev) 544 { 545 struct generic_pm_domain *genpd; 546 int ret; 547 548 dev_dbg(dev, "%s()\n", __func__); 549 550 genpd = dev_to_genpd(dev); 551 if (IS_ERR(genpd)) 552 return -EINVAL; 553 554 /* 555 * If a wakeup request is pending for the device, it should be woken up 556 * at this point and a system wakeup event should be reported if it's 557 * set up to wake up the system from sleep states. 558 */ 559 pm_runtime_get_noresume(dev); 560 if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) 561 pm_wakeup_event(dev, 0); 562 563 if (pm_wakeup_pending()) { 564 pm_runtime_put_sync(dev); 565 return -EBUSY; 566 } 567 568 if (resume_needed(dev, genpd)) 569 pm_runtime_resume(dev); 570 571 genpd_acquire_lock(genpd); 572 573 if (genpd->prepared_count++ == 0) 574 genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF; 575 576 genpd_release_lock(genpd); 577 578 if (genpd->suspend_power_off) { 579 pm_runtime_put_noidle(dev); 580 return 0; 581 } 582 583 /* 584 * The PM domain must be in the GPD_STATE_ACTIVE state at this point, 585 * so pm_genpd_poweron() will return immediately, but if the device 586 * is suspended (e.g. it's been stopped by .stop_device()), we need 587 * to make it operational. 588 */ 589 pm_runtime_resume(dev); 590 __pm_runtime_disable(dev, false); 591 592 ret = pm_generic_prepare(dev); 593 if (ret) { 594 mutex_lock(&genpd->lock); 595 596 if (--genpd->prepared_count == 0) 597 genpd->suspend_power_off = false; 598 599 mutex_unlock(&genpd->lock); 600 pm_runtime_enable(dev); 601 } 602 603 pm_runtime_put_sync(dev); 604 return ret; 605 } 606 607 /** 608 * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain. 609 * @dev: Device to suspend. 610 * 611 * Suspend a device under the assumption that its pm_domain field points to the 612 * domain member of an object of type struct generic_pm_domain representing 613 * a PM domain consisting of I/O devices. 614 */ 615 static int pm_genpd_suspend(struct device *dev) 616 { 617 struct generic_pm_domain *genpd; 618 619 dev_dbg(dev, "%s()\n", __func__); 620 621 genpd = dev_to_genpd(dev); 622 if (IS_ERR(genpd)) 623 return -EINVAL; 624 625 return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev); 626 } 627 628 /** 629 * pm_genpd_suspend_noirq - Late suspend of a device from an I/O PM domain. 630 * @dev: Device to suspend. 631 * 632 * Carry out a late suspend of a device under the assumption that its 633 * pm_domain field points to the domain member of an object of type 634 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 635 */ 636 static int pm_genpd_suspend_noirq(struct device *dev) 637 { 638 struct generic_pm_domain *genpd; 639 int ret; 640 641 dev_dbg(dev, "%s()\n", __func__); 642 643 genpd = dev_to_genpd(dev); 644 if (IS_ERR(genpd)) 645 return -EINVAL; 646 647 if (genpd->suspend_power_off) 648 return 0; 649 650 ret = pm_generic_suspend_noirq(dev); 651 if (ret) 652 return ret; 653 654 if (device_may_wakeup(dev) 655 && genpd->active_wakeup && genpd->active_wakeup(dev)) 656 return 0; 657 658 if (genpd->stop_device) 659 genpd->stop_device(dev); 660 661 /* 662 * Since all of the "noirq" callbacks are executed sequentially, it is 663 * guaranteed that this function will never run twice in parallel for 664 * the same PM domain, so it is not necessary to use locking here. 665 */ 666 genpd->suspended_count++; 667 pm_genpd_sync_poweroff(genpd); 668 669 return 0; 670 } 671 672 /** 673 * pm_genpd_resume_noirq - Early resume of a device from an I/O power domain. 674 * @dev: Device to resume. 675 * 676 * Carry out an early resume of a device under the assumption that its 677 * pm_domain field points to the domain member of an object of type 678 * struct generic_pm_domain representing a power domain consisting of I/O 679 * devices. 680 */ 681 static int pm_genpd_resume_noirq(struct device *dev) 682 { 683 struct generic_pm_domain *genpd; 684 685 dev_dbg(dev, "%s()\n", __func__); 686 687 genpd = dev_to_genpd(dev); 688 if (IS_ERR(genpd)) 689 return -EINVAL; 690 691 if (genpd->suspend_power_off) 692 return 0; 693 694 /* 695 * Since all of the "noirq" callbacks are executed sequentially, it is 696 * guaranteed that this function will never run twice in parallel for 697 * the same PM domain, so it is not necessary to use locking here. 698 */ 699 pm_genpd_poweron(genpd); 700 genpd->suspended_count--; 701 if (genpd->start_device) 702 genpd->start_device(dev); 703 704 return pm_generic_resume_noirq(dev); 705 } 706 707 /** 708 * pm_genpd_resume - Resume a device belonging to an I/O power domain. 709 * @dev: Device to resume. 710 * 711 * Resume a device under the assumption that its pm_domain field points to the 712 * domain member of an object of type struct generic_pm_domain representing 713 * a power domain consisting of I/O devices. 714 */ 715 static int pm_genpd_resume(struct device *dev) 716 { 717 struct generic_pm_domain *genpd; 718 719 dev_dbg(dev, "%s()\n", __func__); 720 721 genpd = dev_to_genpd(dev); 722 if (IS_ERR(genpd)) 723 return -EINVAL; 724 725 return genpd->suspend_power_off ? 0 : pm_generic_resume(dev); 726 } 727 728 /** 729 * pm_genpd_freeze - Freeze a device belonging to an I/O power domain. 730 * @dev: Device to freeze. 731 * 732 * Freeze a device under the assumption that its pm_domain field points to the 733 * domain member of an object of type struct generic_pm_domain representing 734 * a power domain consisting of I/O devices. 735 */ 736 static int pm_genpd_freeze(struct device *dev) 737 { 738 struct generic_pm_domain *genpd; 739 740 dev_dbg(dev, "%s()\n", __func__); 741 742 genpd = dev_to_genpd(dev); 743 if (IS_ERR(genpd)) 744 return -EINVAL; 745 746 return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev); 747 } 748 749 /** 750 * pm_genpd_freeze_noirq - Late freeze of a device from an I/O power domain. 751 * @dev: Device to freeze. 752 * 753 * Carry out a late freeze of a device under the assumption that its 754 * pm_domain field points to the domain member of an object of type 755 * struct generic_pm_domain representing a power domain consisting of I/O 756 * devices. 757 */ 758 static int pm_genpd_freeze_noirq(struct device *dev) 759 { 760 struct generic_pm_domain *genpd; 761 int ret; 762 763 dev_dbg(dev, "%s()\n", __func__); 764 765 genpd = dev_to_genpd(dev); 766 if (IS_ERR(genpd)) 767 return -EINVAL; 768 769 if (genpd->suspend_power_off) 770 return 0; 771 772 ret = pm_generic_freeze_noirq(dev); 773 if (ret) 774 return ret; 775 776 if (genpd->stop_device) 777 genpd->stop_device(dev); 778 779 return 0; 780 } 781 782 /** 783 * pm_genpd_thaw_noirq - Early thaw of a device from an I/O power domain. 784 * @dev: Device to thaw. 785 * 786 * Carry out an early thaw of a device under the assumption that its 787 * pm_domain field points to the domain member of an object of type 788 * struct generic_pm_domain representing a power domain consisting of I/O 789 * devices. 790 */ 791 static int pm_genpd_thaw_noirq(struct device *dev) 792 { 793 struct generic_pm_domain *genpd; 794 795 dev_dbg(dev, "%s()\n", __func__); 796 797 genpd = dev_to_genpd(dev); 798 if (IS_ERR(genpd)) 799 return -EINVAL; 800 801 if (genpd->suspend_power_off) 802 return 0; 803 804 if (genpd->start_device) 805 genpd->start_device(dev); 806 807 return pm_generic_thaw_noirq(dev); 808 } 809 810 /** 811 * pm_genpd_thaw - Thaw a device belonging to an I/O power domain. 812 * @dev: Device to thaw. 813 * 814 * Thaw a device under the assumption that its pm_domain field points to the 815 * domain member of an object of type struct generic_pm_domain representing 816 * a power domain consisting of I/O devices. 817 */ 818 static int pm_genpd_thaw(struct device *dev) 819 { 820 struct generic_pm_domain *genpd; 821 822 dev_dbg(dev, "%s()\n", __func__); 823 824 genpd = dev_to_genpd(dev); 825 if (IS_ERR(genpd)) 826 return -EINVAL; 827 828 return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev); 829 } 830 831 /** 832 * pm_genpd_dev_poweroff - Power off a device belonging to an I/O PM domain. 833 * @dev: Device to suspend. 834 * 835 * Power off a device under the assumption that its pm_domain field points to 836 * the domain member of an object of type struct generic_pm_domain representing 837 * a PM domain consisting of I/O devices. 838 */ 839 static int pm_genpd_dev_poweroff(struct device *dev) 840 { 841 struct generic_pm_domain *genpd; 842 843 dev_dbg(dev, "%s()\n", __func__); 844 845 genpd = dev_to_genpd(dev); 846 if (IS_ERR(genpd)) 847 return -EINVAL; 848 849 return genpd->suspend_power_off ? 0 : pm_generic_poweroff(dev); 850 } 851 852 /** 853 * pm_genpd_dev_poweroff_noirq - Late power off of a device from a PM domain. 854 * @dev: Device to suspend. 855 * 856 * Carry out a late powering off of a device under the assumption that its 857 * pm_domain field points to the domain member of an object of type 858 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 859 */ 860 static int pm_genpd_dev_poweroff_noirq(struct device *dev) 861 { 862 struct generic_pm_domain *genpd; 863 int ret; 864 865 dev_dbg(dev, "%s()\n", __func__); 866 867 genpd = dev_to_genpd(dev); 868 if (IS_ERR(genpd)) 869 return -EINVAL; 870 871 if (genpd->suspend_power_off) 872 return 0; 873 874 ret = pm_generic_poweroff_noirq(dev); 875 if (ret) 876 return ret; 877 878 if (device_may_wakeup(dev) 879 && genpd->active_wakeup && genpd->active_wakeup(dev)) 880 return 0; 881 882 if (genpd->stop_device) 883 genpd->stop_device(dev); 884 885 /* 886 * Since all of the "noirq" callbacks are executed sequentially, it is 887 * guaranteed that this function will never run twice in parallel for 888 * the same PM domain, so it is not necessary to use locking here. 889 */ 890 genpd->suspended_count++; 891 pm_genpd_sync_poweroff(genpd); 892 893 return 0; 894 } 895 896 /** 897 * pm_genpd_restore_noirq - Early restore of a device from an I/O power domain. 898 * @dev: Device to resume. 899 * 900 * Carry out an early restore of a device under the assumption that its 901 * pm_domain field points to the domain member of an object of type 902 * struct generic_pm_domain representing a power domain consisting of I/O 903 * devices. 904 */ 905 static int pm_genpd_restore_noirq(struct device *dev) 906 { 907 struct generic_pm_domain *genpd; 908 909 dev_dbg(dev, "%s()\n", __func__); 910 911 genpd = dev_to_genpd(dev); 912 if (IS_ERR(genpd)) 913 return -EINVAL; 914 915 /* 916 * Since all of the "noirq" callbacks are executed sequentially, it is 917 * guaranteed that this function will never run twice in parallel for 918 * the same PM domain, so it is not necessary to use locking here. 919 */ 920 genpd->status = GPD_STATE_POWER_OFF; 921 if (genpd->suspend_power_off) { 922 /* 923 * The boot kernel might put the domain into the power on state, 924 * so make sure it really is powered off. 925 */ 926 if (genpd->power_off) 927 genpd->power_off(genpd); 928 return 0; 929 } 930 931 pm_genpd_poweron(genpd); 932 genpd->suspended_count--; 933 if (genpd->start_device) 934 genpd->start_device(dev); 935 936 return pm_generic_restore_noirq(dev); 937 } 938 939 /** 940 * pm_genpd_restore - Restore a device belonging to an I/O power domain. 941 * @dev: Device to resume. 942 * 943 * Restore a device under the assumption that its pm_domain field points to the 944 * domain member of an object of type struct generic_pm_domain representing 945 * a power domain consisting of I/O devices. 946 */ 947 static int pm_genpd_restore(struct device *dev) 948 { 949 struct generic_pm_domain *genpd; 950 951 dev_dbg(dev, "%s()\n", __func__); 952 953 genpd = dev_to_genpd(dev); 954 if (IS_ERR(genpd)) 955 return -EINVAL; 956 957 return genpd->suspend_power_off ? 0 : pm_generic_restore(dev); 958 } 959 960 /** 961 * pm_genpd_complete - Complete power transition of a device in a power domain. 962 * @dev: Device to complete the transition of. 963 * 964 * Complete a power transition of a device (during a system-wide power 965 * transition) under the assumption that its pm_domain field points to the 966 * domain member of an object of type struct generic_pm_domain representing 967 * a power domain consisting of I/O devices. 968 */ 969 static void pm_genpd_complete(struct device *dev) 970 { 971 struct generic_pm_domain *genpd; 972 bool run_complete; 973 974 dev_dbg(dev, "%s()\n", __func__); 975 976 genpd = dev_to_genpd(dev); 977 if (IS_ERR(genpd)) 978 return; 979 980 mutex_lock(&genpd->lock); 981 982 run_complete = !genpd->suspend_power_off; 983 if (--genpd->prepared_count == 0) 984 genpd->suspend_power_off = false; 985 986 mutex_unlock(&genpd->lock); 987 988 if (run_complete) { 989 pm_generic_complete(dev); 990 pm_runtime_set_active(dev); 991 pm_runtime_enable(dev); 992 pm_runtime_idle(dev); 993 } 994 } 995 996 #else 997 998 #define pm_genpd_prepare NULL 999 #define pm_genpd_suspend NULL 1000 #define pm_genpd_suspend_noirq NULL 1001 #define pm_genpd_resume_noirq NULL 1002 #define pm_genpd_resume NULL 1003 #define pm_genpd_freeze NULL 1004 #define pm_genpd_freeze_noirq NULL 1005 #define pm_genpd_thaw_noirq NULL 1006 #define pm_genpd_thaw NULL 1007 #define pm_genpd_dev_poweroff_noirq NULL 1008 #define pm_genpd_dev_poweroff NULL 1009 #define pm_genpd_restore_noirq NULL 1010 #define pm_genpd_restore NULL 1011 #define pm_genpd_complete NULL 1012 1013 #endif /* CONFIG_PM_SLEEP */ 1014 1015 /** 1016 * pm_genpd_add_device - Add a device to an I/O PM domain. 1017 * @genpd: PM domain to add the device to. 1018 * @dev: Device to be added. 1019 */ 1020 int pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev) 1021 { 1022 struct dev_list_entry *dle; 1023 int ret = 0; 1024 1025 dev_dbg(dev, "%s()\n", __func__); 1026 1027 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) 1028 return -EINVAL; 1029 1030 genpd_acquire_lock(genpd); 1031 1032 if (genpd->status == GPD_STATE_POWER_OFF) { 1033 ret = -EINVAL; 1034 goto out; 1035 } 1036 1037 if (genpd->prepared_count > 0) { 1038 ret = -EAGAIN; 1039 goto out; 1040 } 1041 1042 list_for_each_entry(dle, &genpd->dev_list, node) 1043 if (dle->dev == dev) { 1044 ret = -EINVAL; 1045 goto out; 1046 } 1047 1048 dle = kzalloc(sizeof(*dle), GFP_KERNEL); 1049 if (!dle) { 1050 ret = -ENOMEM; 1051 goto out; 1052 } 1053 1054 dle->dev = dev; 1055 dle->need_restore = false; 1056 list_add_tail(&dle->node, &genpd->dev_list); 1057 genpd->device_count++; 1058 1059 spin_lock_irq(&dev->power.lock); 1060 dev->pm_domain = &genpd->domain; 1061 spin_unlock_irq(&dev->power.lock); 1062 1063 out: 1064 genpd_release_lock(genpd); 1065 1066 return ret; 1067 } 1068 1069 /** 1070 * pm_genpd_remove_device - Remove a device from an I/O PM domain. 1071 * @genpd: PM domain to remove the device from. 1072 * @dev: Device to be removed. 1073 */ 1074 int pm_genpd_remove_device(struct generic_pm_domain *genpd, 1075 struct device *dev) 1076 { 1077 struct dev_list_entry *dle; 1078 int ret = -EINVAL; 1079 1080 dev_dbg(dev, "%s()\n", __func__); 1081 1082 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) 1083 return -EINVAL; 1084 1085 genpd_acquire_lock(genpd); 1086 1087 if (genpd->prepared_count > 0) { 1088 ret = -EAGAIN; 1089 goto out; 1090 } 1091 1092 list_for_each_entry(dle, &genpd->dev_list, node) { 1093 if (dle->dev != dev) 1094 continue; 1095 1096 spin_lock_irq(&dev->power.lock); 1097 dev->pm_domain = NULL; 1098 spin_unlock_irq(&dev->power.lock); 1099 1100 genpd->device_count--; 1101 list_del(&dle->node); 1102 kfree(dle); 1103 1104 ret = 0; 1105 break; 1106 } 1107 1108 out: 1109 genpd_release_lock(genpd); 1110 1111 return ret; 1112 } 1113 1114 /** 1115 * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain. 1116 * @genpd: Master PM domain to add the subdomain to. 1117 * @new_subdomain: Subdomain to be added. 1118 */ 1119 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd, 1120 struct generic_pm_domain *new_subdomain) 1121 { 1122 struct generic_pm_domain *subdomain; 1123 int ret = 0; 1124 1125 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(new_subdomain)) 1126 return -EINVAL; 1127 1128 start: 1129 genpd_acquire_lock(genpd); 1130 mutex_lock_nested(&new_subdomain->lock, SINGLE_DEPTH_NESTING); 1131 1132 if (new_subdomain->status != GPD_STATE_POWER_OFF 1133 && new_subdomain->status != GPD_STATE_ACTIVE) { 1134 mutex_unlock(&new_subdomain->lock); 1135 genpd_release_lock(genpd); 1136 goto start; 1137 } 1138 1139 if (genpd->status == GPD_STATE_POWER_OFF 1140 && new_subdomain->status != GPD_STATE_POWER_OFF) { 1141 ret = -EINVAL; 1142 goto out; 1143 } 1144 1145 list_for_each_entry(subdomain, &genpd->sd_list, sd_node) { 1146 if (subdomain == new_subdomain) { 1147 ret = -EINVAL; 1148 goto out; 1149 } 1150 } 1151 1152 list_add_tail(&new_subdomain->sd_node, &genpd->sd_list); 1153 new_subdomain->parent = genpd; 1154 if (subdomain->status != GPD_STATE_POWER_OFF) 1155 genpd->sd_count++; 1156 1157 out: 1158 mutex_unlock(&new_subdomain->lock); 1159 genpd_release_lock(genpd); 1160 1161 return ret; 1162 } 1163 1164 /** 1165 * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain. 1166 * @genpd: Master PM domain to remove the subdomain from. 1167 * @target: Subdomain to be removed. 1168 */ 1169 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, 1170 struct generic_pm_domain *target) 1171 { 1172 struct generic_pm_domain *subdomain; 1173 int ret = -EINVAL; 1174 1175 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(target)) 1176 return -EINVAL; 1177 1178 start: 1179 genpd_acquire_lock(genpd); 1180 1181 list_for_each_entry(subdomain, &genpd->sd_list, sd_node) { 1182 if (subdomain != target) 1183 continue; 1184 1185 mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING); 1186 1187 if (subdomain->status != GPD_STATE_POWER_OFF 1188 && subdomain->status != GPD_STATE_ACTIVE) { 1189 mutex_unlock(&subdomain->lock); 1190 genpd_release_lock(genpd); 1191 goto start; 1192 } 1193 1194 list_del(&subdomain->sd_node); 1195 subdomain->parent = NULL; 1196 if (subdomain->status != GPD_STATE_POWER_OFF) 1197 genpd_sd_counter_dec(genpd); 1198 1199 mutex_unlock(&subdomain->lock); 1200 1201 ret = 0; 1202 break; 1203 } 1204 1205 genpd_release_lock(genpd); 1206 1207 return ret; 1208 } 1209 1210 /** 1211 * pm_genpd_init - Initialize a generic I/O PM domain object. 1212 * @genpd: PM domain object to initialize. 1213 * @gov: PM domain governor to associate with the domain (may be NULL). 1214 * @is_off: Initial value of the domain's power_is_off field. 1215 */ 1216 void pm_genpd_init(struct generic_pm_domain *genpd, 1217 struct dev_power_governor *gov, bool is_off) 1218 { 1219 if (IS_ERR_OR_NULL(genpd)) 1220 return; 1221 1222 INIT_LIST_HEAD(&genpd->sd_node); 1223 genpd->parent = NULL; 1224 INIT_LIST_HEAD(&genpd->dev_list); 1225 INIT_LIST_HEAD(&genpd->sd_list); 1226 mutex_init(&genpd->lock); 1227 genpd->gov = gov; 1228 INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn); 1229 genpd->in_progress = 0; 1230 genpd->sd_count = 0; 1231 genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE; 1232 init_waitqueue_head(&genpd->status_wait_queue); 1233 genpd->poweroff_task = NULL; 1234 genpd->resume_count = 0; 1235 genpd->device_count = 0; 1236 genpd->suspended_count = 0; 1237 genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend; 1238 genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume; 1239 genpd->domain.ops.runtime_idle = pm_generic_runtime_idle; 1240 genpd->domain.ops.prepare = pm_genpd_prepare; 1241 genpd->domain.ops.suspend = pm_genpd_suspend; 1242 genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq; 1243 genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq; 1244 genpd->domain.ops.resume = pm_genpd_resume; 1245 genpd->domain.ops.freeze = pm_genpd_freeze; 1246 genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq; 1247 genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq; 1248 genpd->domain.ops.thaw = pm_genpd_thaw; 1249 genpd->domain.ops.poweroff = pm_genpd_dev_poweroff; 1250 genpd->domain.ops.poweroff_noirq = pm_genpd_dev_poweroff_noirq; 1251 genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq; 1252 genpd->domain.ops.restore = pm_genpd_restore; 1253 genpd->domain.ops.complete = pm_genpd_complete; 1254 mutex_lock(&gpd_list_lock); 1255 list_add(&genpd->gpd_list_node, &gpd_list); 1256 mutex_unlock(&gpd_list_lock); 1257 } 1258 1259 /** 1260 * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use. 1261 */ 1262 void pm_genpd_poweroff_unused(void) 1263 { 1264 struct generic_pm_domain *genpd; 1265 1266 mutex_lock(&gpd_list_lock); 1267 1268 list_for_each_entry(genpd, &gpd_list, gpd_list_node) 1269 genpd_queue_power_off_work(genpd); 1270 1271 mutex_unlock(&gpd_list_lock); 1272 } 1273