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/delay.h> 10 #include <linux/kernel.h> 11 #include <linux/io.h> 12 #include <linux/platform_device.h> 13 #include <linux/pm_runtime.h> 14 #include <linux/pm_domain.h> 15 #include <linux/pm_qos.h> 16 #include <linux/pm_clock.h> 17 #include <linux/slab.h> 18 #include <linux/err.h> 19 #include <linux/sched.h> 20 #include <linux/suspend.h> 21 #include <linux/export.h> 22 23 #include "power.h" 24 25 #define GENPD_RETRY_MAX_MS 250 /* Approximate */ 26 27 #define GENPD_DEV_CALLBACK(genpd, type, callback, dev) \ 28 ({ \ 29 type (*__routine)(struct device *__d); \ 30 type __ret = (type)0; \ 31 \ 32 __routine = genpd->dev_ops.callback; \ 33 if (__routine) { \ 34 __ret = __routine(dev); \ 35 } \ 36 __ret; \ 37 }) 38 39 static LIST_HEAD(gpd_list); 40 static DEFINE_MUTEX(gpd_list_lock); 41 42 struct genpd_lock_ops { 43 void (*lock)(struct generic_pm_domain *genpd); 44 void (*lock_nested)(struct generic_pm_domain *genpd, int depth); 45 int (*lock_interruptible)(struct generic_pm_domain *genpd); 46 void (*unlock)(struct generic_pm_domain *genpd); 47 }; 48 49 static void genpd_lock_mtx(struct generic_pm_domain *genpd) 50 { 51 mutex_lock(&genpd->mlock); 52 } 53 54 static void genpd_lock_nested_mtx(struct generic_pm_domain *genpd, 55 int depth) 56 { 57 mutex_lock_nested(&genpd->mlock, depth); 58 } 59 60 static int genpd_lock_interruptible_mtx(struct generic_pm_domain *genpd) 61 { 62 return mutex_lock_interruptible(&genpd->mlock); 63 } 64 65 static void genpd_unlock_mtx(struct generic_pm_domain *genpd) 66 { 67 return mutex_unlock(&genpd->mlock); 68 } 69 70 static const struct genpd_lock_ops genpd_mtx_ops = { 71 .lock = genpd_lock_mtx, 72 .lock_nested = genpd_lock_nested_mtx, 73 .lock_interruptible = genpd_lock_interruptible_mtx, 74 .unlock = genpd_unlock_mtx, 75 }; 76 77 static void genpd_lock_spin(struct generic_pm_domain *genpd) 78 __acquires(&genpd->slock) 79 { 80 unsigned long flags; 81 82 spin_lock_irqsave(&genpd->slock, flags); 83 genpd->lock_flags = flags; 84 } 85 86 static void genpd_lock_nested_spin(struct generic_pm_domain *genpd, 87 int depth) 88 __acquires(&genpd->slock) 89 { 90 unsigned long flags; 91 92 spin_lock_irqsave_nested(&genpd->slock, flags, depth); 93 genpd->lock_flags = flags; 94 } 95 96 static int genpd_lock_interruptible_spin(struct generic_pm_domain *genpd) 97 __acquires(&genpd->slock) 98 { 99 unsigned long flags; 100 101 spin_lock_irqsave(&genpd->slock, flags); 102 genpd->lock_flags = flags; 103 return 0; 104 } 105 106 static void genpd_unlock_spin(struct generic_pm_domain *genpd) 107 __releases(&genpd->slock) 108 { 109 spin_unlock_irqrestore(&genpd->slock, genpd->lock_flags); 110 } 111 112 static const struct genpd_lock_ops genpd_spin_ops = { 113 .lock = genpd_lock_spin, 114 .lock_nested = genpd_lock_nested_spin, 115 .lock_interruptible = genpd_lock_interruptible_spin, 116 .unlock = genpd_unlock_spin, 117 }; 118 119 #define genpd_lock(p) p->lock_ops->lock(p) 120 #define genpd_lock_nested(p, d) p->lock_ops->lock_nested(p, d) 121 #define genpd_lock_interruptible(p) p->lock_ops->lock_interruptible(p) 122 #define genpd_unlock(p) p->lock_ops->unlock(p) 123 124 #define genpd_is_irq_safe(genpd) (genpd->flags & GENPD_FLAG_IRQ_SAFE) 125 126 static inline bool irq_safe_dev_in_no_sleep_domain(struct device *dev, 127 struct generic_pm_domain *genpd) 128 { 129 bool ret; 130 131 ret = pm_runtime_is_irq_safe(dev) && !genpd_is_irq_safe(genpd); 132 133 /* Warn once for each IRQ safe dev in no sleep domain */ 134 if (ret) 135 dev_warn_once(dev, "PM domain %s will not be powered off\n", 136 genpd->name); 137 138 return ret; 139 } 140 141 /* 142 * Get the generic PM domain for a particular struct device. 143 * This validates the struct device pointer, the PM domain pointer, 144 * and checks that the PM domain pointer is a real generic PM domain. 145 * Any failure results in NULL being returned. 146 */ 147 static struct generic_pm_domain *genpd_lookup_dev(struct device *dev) 148 { 149 struct generic_pm_domain *genpd = NULL, *gpd; 150 151 if (IS_ERR_OR_NULL(dev) || IS_ERR_OR_NULL(dev->pm_domain)) 152 return NULL; 153 154 mutex_lock(&gpd_list_lock); 155 list_for_each_entry(gpd, &gpd_list, gpd_list_node) { 156 if (&gpd->domain == dev->pm_domain) { 157 genpd = gpd; 158 break; 159 } 160 } 161 mutex_unlock(&gpd_list_lock); 162 163 return genpd; 164 } 165 166 /* 167 * This should only be used where we are certain that the pm_domain 168 * attached to the device is a genpd domain. 169 */ 170 static struct generic_pm_domain *dev_to_genpd(struct device *dev) 171 { 172 if (IS_ERR_OR_NULL(dev->pm_domain)) 173 return ERR_PTR(-EINVAL); 174 175 return pd_to_genpd(dev->pm_domain); 176 } 177 178 static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev) 179 { 180 return GENPD_DEV_CALLBACK(genpd, int, stop, dev); 181 } 182 183 static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev) 184 { 185 return GENPD_DEV_CALLBACK(genpd, int, start, dev); 186 } 187 188 static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd) 189 { 190 bool ret = false; 191 192 if (!WARN_ON(atomic_read(&genpd->sd_count) == 0)) 193 ret = !!atomic_dec_and_test(&genpd->sd_count); 194 195 return ret; 196 } 197 198 static void genpd_sd_counter_inc(struct generic_pm_domain *genpd) 199 { 200 atomic_inc(&genpd->sd_count); 201 smp_mb__after_atomic(); 202 } 203 204 static int genpd_power_on(struct generic_pm_domain *genpd, bool timed) 205 { 206 unsigned int state_idx = genpd->state_idx; 207 ktime_t time_start; 208 s64 elapsed_ns; 209 int ret; 210 211 if (!genpd->power_on) 212 return 0; 213 214 if (!timed) 215 return genpd->power_on(genpd); 216 217 time_start = ktime_get(); 218 ret = genpd->power_on(genpd); 219 if (ret) 220 return ret; 221 222 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); 223 if (elapsed_ns <= genpd->states[state_idx].power_on_latency_ns) 224 return ret; 225 226 genpd->states[state_idx].power_on_latency_ns = elapsed_ns; 227 genpd->max_off_time_changed = true; 228 pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n", 229 genpd->name, "on", elapsed_ns); 230 231 return ret; 232 } 233 234 static int genpd_power_off(struct generic_pm_domain *genpd, bool timed) 235 { 236 unsigned int state_idx = genpd->state_idx; 237 ktime_t time_start; 238 s64 elapsed_ns; 239 int ret; 240 241 if (!genpd->power_off) 242 return 0; 243 244 if (!timed) 245 return genpd->power_off(genpd); 246 247 time_start = ktime_get(); 248 ret = genpd->power_off(genpd); 249 if (ret == -EBUSY) 250 return ret; 251 252 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); 253 if (elapsed_ns <= genpd->states[state_idx].power_off_latency_ns) 254 return ret; 255 256 genpd->states[state_idx].power_off_latency_ns = elapsed_ns; 257 genpd->max_off_time_changed = true; 258 pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n", 259 genpd->name, "off", elapsed_ns); 260 261 return ret; 262 } 263 264 /** 265 * genpd_queue_power_off_work - Queue up the execution of genpd_poweroff(). 266 * @genpd: PM domain to power off. 267 * 268 * Queue up the execution of genpd_poweroff() unless it's already been done 269 * before. 270 */ 271 static void genpd_queue_power_off_work(struct generic_pm_domain *genpd) 272 { 273 queue_work(pm_wq, &genpd->power_off_work); 274 } 275 276 /** 277 * genpd_poweron - Restore power to a given PM domain and its masters. 278 * @genpd: PM domain to power up. 279 * @depth: nesting count for lockdep. 280 * 281 * Restore power to @genpd and all of its masters so that it is possible to 282 * resume a device belonging to it. 283 */ 284 static int genpd_poweron(struct generic_pm_domain *genpd, unsigned int depth) 285 { 286 struct gpd_link *link; 287 int ret = 0; 288 289 if (genpd->status == GPD_STATE_ACTIVE) 290 return 0; 291 292 /* 293 * The list is guaranteed not to change while the loop below is being 294 * executed, unless one of the masters' .power_on() callbacks fiddles 295 * with it. 296 */ 297 list_for_each_entry(link, &genpd->slave_links, slave_node) { 298 struct generic_pm_domain *master = link->master; 299 300 genpd_sd_counter_inc(master); 301 302 genpd_lock_nested(master, depth + 1); 303 ret = genpd_poweron(master, depth + 1); 304 genpd_unlock(master); 305 306 if (ret) { 307 genpd_sd_counter_dec(master); 308 goto err; 309 } 310 } 311 312 ret = genpd_power_on(genpd, true); 313 if (ret) 314 goto err; 315 316 genpd->status = GPD_STATE_ACTIVE; 317 return 0; 318 319 err: 320 list_for_each_entry_continue_reverse(link, 321 &genpd->slave_links, 322 slave_node) { 323 genpd_sd_counter_dec(link->master); 324 genpd_queue_power_off_work(link->master); 325 } 326 327 return ret; 328 } 329 330 static int genpd_dev_pm_qos_notifier(struct notifier_block *nb, 331 unsigned long val, void *ptr) 332 { 333 struct generic_pm_domain_data *gpd_data; 334 struct device *dev; 335 336 gpd_data = container_of(nb, struct generic_pm_domain_data, nb); 337 dev = gpd_data->base.dev; 338 339 for (;;) { 340 struct generic_pm_domain *genpd; 341 struct pm_domain_data *pdd; 342 343 spin_lock_irq(&dev->power.lock); 344 345 pdd = dev->power.subsys_data ? 346 dev->power.subsys_data->domain_data : NULL; 347 if (pdd && pdd->dev) { 348 to_gpd_data(pdd)->td.constraint_changed = true; 349 genpd = dev_to_genpd(dev); 350 } else { 351 genpd = ERR_PTR(-ENODATA); 352 } 353 354 spin_unlock_irq(&dev->power.lock); 355 356 if (!IS_ERR(genpd)) { 357 genpd_lock(genpd); 358 genpd->max_off_time_changed = true; 359 genpd_unlock(genpd); 360 } 361 362 dev = dev->parent; 363 if (!dev || dev->power.ignore_children) 364 break; 365 } 366 367 return NOTIFY_DONE; 368 } 369 370 /** 371 * genpd_poweroff - Remove power from a given PM domain. 372 * @genpd: PM domain to power down. 373 * @is_async: PM domain is powered down from a scheduled work 374 * 375 * If all of the @genpd's devices have been suspended and all of its subdomains 376 * have been powered down, remove power from @genpd. 377 */ 378 static int genpd_poweroff(struct generic_pm_domain *genpd, bool is_async) 379 { 380 struct pm_domain_data *pdd; 381 struct gpd_link *link; 382 unsigned int not_suspended = 0; 383 384 /* 385 * Do not try to power off the domain in the following situations: 386 * (1) The domain is already in the "power off" state. 387 * (2) System suspend is in progress. 388 */ 389 if (genpd->status == GPD_STATE_POWER_OFF 390 || genpd->prepared_count > 0) 391 return 0; 392 393 if (atomic_read(&genpd->sd_count) > 0) 394 return -EBUSY; 395 396 list_for_each_entry(pdd, &genpd->dev_list, list_node) { 397 enum pm_qos_flags_status stat; 398 399 stat = dev_pm_qos_flags(pdd->dev, 400 PM_QOS_FLAG_NO_POWER_OFF 401 | PM_QOS_FLAG_REMOTE_WAKEUP); 402 if (stat > PM_QOS_FLAGS_NONE) 403 return -EBUSY; 404 405 /* 406 * Do not allow PM domain to be powered off, when an IRQ safe 407 * device is part of a non-IRQ safe domain. 408 */ 409 if (!pm_runtime_suspended(pdd->dev) || 410 irq_safe_dev_in_no_sleep_domain(pdd->dev, genpd)) 411 not_suspended++; 412 } 413 414 if (not_suspended > 1 || (not_suspended == 1 && is_async)) 415 return -EBUSY; 416 417 if (genpd->gov && genpd->gov->power_down_ok) { 418 if (!genpd->gov->power_down_ok(&genpd->domain)) 419 return -EAGAIN; 420 } 421 422 if (genpd->power_off) { 423 int ret; 424 425 if (atomic_read(&genpd->sd_count) > 0) 426 return -EBUSY; 427 428 /* 429 * If sd_count > 0 at this point, one of the subdomains hasn't 430 * managed to call genpd_poweron() for the master yet after 431 * incrementing it. In that case genpd_poweron() will wait 432 * for us to drop the lock, so we can call .power_off() and let 433 * the genpd_poweron() restore power for us (this shouldn't 434 * happen very often). 435 */ 436 ret = genpd_power_off(genpd, true); 437 if (ret) 438 return ret; 439 } 440 441 genpd->status = GPD_STATE_POWER_OFF; 442 443 list_for_each_entry(link, &genpd->slave_links, slave_node) { 444 genpd_sd_counter_dec(link->master); 445 genpd_queue_power_off_work(link->master); 446 } 447 448 return 0; 449 } 450 451 /** 452 * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0. 453 * @work: Work structure used for scheduling the execution of this function. 454 */ 455 static void genpd_power_off_work_fn(struct work_struct *work) 456 { 457 struct generic_pm_domain *genpd; 458 459 genpd = container_of(work, struct generic_pm_domain, power_off_work); 460 461 genpd_lock(genpd); 462 genpd_poweroff(genpd, true); 463 genpd_unlock(genpd); 464 } 465 466 /** 467 * __genpd_runtime_suspend - walk the hierarchy of ->runtime_suspend() callbacks 468 * @dev: Device to handle. 469 */ 470 static int __genpd_runtime_suspend(struct device *dev) 471 { 472 int (*cb)(struct device *__dev); 473 474 if (dev->type && dev->type->pm) 475 cb = dev->type->pm->runtime_suspend; 476 else if (dev->class && dev->class->pm) 477 cb = dev->class->pm->runtime_suspend; 478 else if (dev->bus && dev->bus->pm) 479 cb = dev->bus->pm->runtime_suspend; 480 else 481 cb = NULL; 482 483 if (!cb && dev->driver && dev->driver->pm) 484 cb = dev->driver->pm->runtime_suspend; 485 486 return cb ? cb(dev) : 0; 487 } 488 489 /** 490 * __genpd_runtime_resume - walk the hierarchy of ->runtime_resume() callbacks 491 * @dev: Device to handle. 492 */ 493 static int __genpd_runtime_resume(struct device *dev) 494 { 495 int (*cb)(struct device *__dev); 496 497 if (dev->type && dev->type->pm) 498 cb = dev->type->pm->runtime_resume; 499 else if (dev->class && dev->class->pm) 500 cb = dev->class->pm->runtime_resume; 501 else if (dev->bus && dev->bus->pm) 502 cb = dev->bus->pm->runtime_resume; 503 else 504 cb = NULL; 505 506 if (!cb && dev->driver && dev->driver->pm) 507 cb = dev->driver->pm->runtime_resume; 508 509 return cb ? cb(dev) : 0; 510 } 511 512 /** 513 * genpd_runtime_suspend - Suspend a device belonging to I/O PM domain. 514 * @dev: Device to suspend. 515 * 516 * Carry out a runtime suspend of a device under the assumption that its 517 * pm_domain field points to the domain member of an object of type 518 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 519 */ 520 static int genpd_runtime_suspend(struct device *dev) 521 { 522 struct generic_pm_domain *genpd; 523 bool (*suspend_ok)(struct device *__dev); 524 struct gpd_timing_data *td = &dev_gpd_data(dev)->td; 525 bool runtime_pm = pm_runtime_enabled(dev); 526 ktime_t time_start; 527 s64 elapsed_ns; 528 int ret; 529 530 dev_dbg(dev, "%s()\n", __func__); 531 532 genpd = dev_to_genpd(dev); 533 if (IS_ERR(genpd)) 534 return -EINVAL; 535 536 /* 537 * A runtime PM centric subsystem/driver may re-use the runtime PM 538 * callbacks for other purposes than runtime PM. In those scenarios 539 * runtime PM is disabled. Under these circumstances, we shall skip 540 * validating/measuring the PM QoS latency. 541 */ 542 suspend_ok = genpd->gov ? genpd->gov->suspend_ok : NULL; 543 if (runtime_pm && suspend_ok && !suspend_ok(dev)) 544 return -EBUSY; 545 546 /* Measure suspend latency. */ 547 time_start = 0; 548 if (runtime_pm) 549 time_start = ktime_get(); 550 551 ret = __genpd_runtime_suspend(dev); 552 if (ret) 553 return ret; 554 555 ret = genpd_stop_dev(genpd, dev); 556 if (ret) { 557 __genpd_runtime_resume(dev); 558 return ret; 559 } 560 561 /* Update suspend latency value if the measured time exceeds it. */ 562 if (runtime_pm) { 563 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); 564 if (elapsed_ns > td->suspend_latency_ns) { 565 td->suspend_latency_ns = elapsed_ns; 566 dev_dbg(dev, "suspend latency exceeded, %lld ns\n", 567 elapsed_ns); 568 genpd->max_off_time_changed = true; 569 td->constraint_changed = true; 570 } 571 } 572 573 /* 574 * If power.irq_safe is set, this routine may be run with 575 * IRQs disabled, so suspend only if the PM domain also is irq_safe. 576 */ 577 if (irq_safe_dev_in_no_sleep_domain(dev, genpd)) 578 return 0; 579 580 genpd_lock(genpd); 581 genpd_poweroff(genpd, false); 582 genpd_unlock(genpd); 583 584 return 0; 585 } 586 587 /** 588 * genpd_runtime_resume - Resume a device belonging to I/O PM domain. 589 * @dev: Device to resume. 590 * 591 * Carry out a runtime resume of a device under the assumption that its 592 * pm_domain field points to the domain member of an object of type 593 * struct generic_pm_domain representing a PM domain consisting of I/O devices. 594 */ 595 static int genpd_runtime_resume(struct device *dev) 596 { 597 struct generic_pm_domain *genpd; 598 struct gpd_timing_data *td = &dev_gpd_data(dev)->td; 599 bool runtime_pm = pm_runtime_enabled(dev); 600 ktime_t time_start; 601 s64 elapsed_ns; 602 int ret; 603 bool timed = true; 604 605 dev_dbg(dev, "%s()\n", __func__); 606 607 genpd = dev_to_genpd(dev); 608 if (IS_ERR(genpd)) 609 return -EINVAL; 610 611 /* 612 * As we don't power off a non IRQ safe domain, which holds 613 * an IRQ safe device, we don't need to restore power to it. 614 */ 615 if (irq_safe_dev_in_no_sleep_domain(dev, genpd)) { 616 timed = false; 617 goto out; 618 } 619 620 genpd_lock(genpd); 621 ret = genpd_poweron(genpd, 0); 622 genpd_unlock(genpd); 623 624 if (ret) 625 return ret; 626 627 out: 628 /* Measure resume latency. */ 629 if (timed && runtime_pm) 630 time_start = ktime_get(); 631 632 ret = genpd_start_dev(genpd, dev); 633 if (ret) 634 goto err_poweroff; 635 636 ret = __genpd_runtime_resume(dev); 637 if (ret) 638 goto err_stop; 639 640 /* Update resume latency value if the measured time exceeds it. */ 641 if (timed && runtime_pm) { 642 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start)); 643 if (elapsed_ns > td->resume_latency_ns) { 644 td->resume_latency_ns = elapsed_ns; 645 dev_dbg(dev, "resume latency exceeded, %lld ns\n", 646 elapsed_ns); 647 genpd->max_off_time_changed = true; 648 td->constraint_changed = true; 649 } 650 } 651 652 return 0; 653 654 err_stop: 655 genpd_stop_dev(genpd, dev); 656 err_poweroff: 657 if (!pm_runtime_is_irq_safe(dev) || 658 (pm_runtime_is_irq_safe(dev) && genpd_is_irq_safe(genpd))) { 659 genpd_lock(genpd); 660 genpd_poweroff(genpd, 0); 661 genpd_unlock(genpd); 662 } 663 664 return ret; 665 } 666 667 static bool pd_ignore_unused; 668 static int __init pd_ignore_unused_setup(char *__unused) 669 { 670 pd_ignore_unused = true; 671 return 1; 672 } 673 __setup("pd_ignore_unused", pd_ignore_unused_setup); 674 675 /** 676 * genpd_poweroff_unused - Power off all PM domains with no devices in use. 677 */ 678 static int __init genpd_poweroff_unused(void) 679 { 680 struct generic_pm_domain *genpd; 681 682 if (pd_ignore_unused) { 683 pr_warn("genpd: Not disabling unused power domains\n"); 684 return 0; 685 } 686 687 mutex_lock(&gpd_list_lock); 688 689 list_for_each_entry(genpd, &gpd_list, gpd_list_node) 690 genpd_queue_power_off_work(genpd); 691 692 mutex_unlock(&gpd_list_lock); 693 694 return 0; 695 } 696 late_initcall(genpd_poweroff_unused); 697 698 #if defined(CONFIG_PM_SLEEP) || defined(CONFIG_PM_GENERIC_DOMAINS_OF) 699 700 /** 701 * pm_genpd_present - Check if the given PM domain has been initialized. 702 * @genpd: PM domain to check. 703 */ 704 static bool pm_genpd_present(const struct generic_pm_domain *genpd) 705 { 706 const struct generic_pm_domain *gpd; 707 708 if (IS_ERR_OR_NULL(genpd)) 709 return false; 710 711 list_for_each_entry(gpd, &gpd_list, gpd_list_node) 712 if (gpd == genpd) 713 return true; 714 715 return false; 716 } 717 718 #endif 719 720 #ifdef CONFIG_PM_SLEEP 721 722 static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd, 723 struct device *dev) 724 { 725 return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev); 726 } 727 728 /** 729 * genpd_sync_poweroff - Synchronously power off a PM domain and its masters. 730 * @genpd: PM domain to power off, if possible. 731 * 732 * Check if the given PM domain can be powered off (during system suspend or 733 * hibernation) and do that if so. Also, in that case propagate to its masters. 734 * 735 * This function is only called in "noirq" and "syscore" stages of system power 736 * transitions, so it need not acquire locks (all of the "noirq" callbacks are 737 * executed sequentially, so it is guaranteed that it will never run twice in 738 * parallel). 739 */ 740 static void genpd_sync_poweroff(struct generic_pm_domain *genpd) 741 { 742 struct gpd_link *link; 743 744 if (genpd->status == GPD_STATE_POWER_OFF) 745 return; 746 747 if (genpd->suspended_count != genpd->device_count 748 || atomic_read(&genpd->sd_count) > 0) 749 return; 750 751 /* Choose the deepest state when suspending */ 752 genpd->state_idx = genpd->state_count - 1; 753 genpd_power_off(genpd, false); 754 755 genpd->status = GPD_STATE_POWER_OFF; 756 757 list_for_each_entry(link, &genpd->slave_links, slave_node) { 758 genpd_sd_counter_dec(link->master); 759 genpd_sync_poweroff(link->master); 760 } 761 } 762 763 /** 764 * genpd_sync_poweron - Synchronously power on a PM domain and its masters. 765 * @genpd: PM domain to power on. 766 * 767 * This function is only called in "noirq" and "syscore" stages of system power 768 * transitions, so it need not acquire locks (all of the "noirq" callbacks are 769 * executed sequentially, so it is guaranteed that it will never run twice in 770 * parallel). 771 */ 772 static void genpd_sync_poweron(struct generic_pm_domain *genpd) 773 { 774 struct gpd_link *link; 775 776 if (genpd->status == GPD_STATE_ACTIVE) 777 return; 778 779 list_for_each_entry(link, &genpd->slave_links, slave_node) { 780 genpd_sync_poweron(link->master); 781 genpd_sd_counter_inc(link->master); 782 } 783 784 genpd_power_on(genpd, false); 785 786 genpd->status = GPD_STATE_ACTIVE; 787 } 788 789 /** 790 * resume_needed - Check whether to resume a device before system suspend. 791 * @dev: Device to check. 792 * @genpd: PM domain the device belongs to. 793 * 794 * There are two cases in which a device that can wake up the system from sleep 795 * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled 796 * to wake up the system and it has to remain active for this purpose while the 797 * system is in the sleep state and (2) if the device is not enabled to wake up 798 * the system from sleep states and it generally doesn't generate wakeup signals 799 * by itself (those signals are generated on its behalf by other parts of the 800 * system). In the latter case it may be necessary to reconfigure the device's 801 * wakeup settings during system suspend, because it may have been set up to 802 * signal remote wakeup from the system's working state as needed by runtime PM. 803 * Return 'true' in either of the above cases. 804 */ 805 static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd) 806 { 807 bool active_wakeup; 808 809 if (!device_can_wakeup(dev)) 810 return false; 811 812 active_wakeup = genpd_dev_active_wakeup(genpd, dev); 813 return device_may_wakeup(dev) ? active_wakeup : !active_wakeup; 814 } 815 816 /** 817 * pm_genpd_prepare - Start power transition of a device in a PM domain. 818 * @dev: Device to start the transition of. 819 * 820 * Start a power transition of a device (during a system-wide power transition) 821 * under the assumption that its pm_domain field points to the domain member of 822 * an object of type struct generic_pm_domain representing a PM domain 823 * consisting of I/O devices. 824 */ 825 static int pm_genpd_prepare(struct device *dev) 826 { 827 struct generic_pm_domain *genpd; 828 int ret; 829 830 dev_dbg(dev, "%s()\n", __func__); 831 832 genpd = dev_to_genpd(dev); 833 if (IS_ERR(genpd)) 834 return -EINVAL; 835 836 /* 837 * If a wakeup request is pending for the device, it should be woken up 838 * at this point and a system wakeup event should be reported if it's 839 * set up to wake up the system from sleep states. 840 */ 841 if (resume_needed(dev, genpd)) 842 pm_runtime_resume(dev); 843 844 genpd_lock(genpd); 845 846 if (genpd->prepared_count++ == 0) 847 genpd->suspended_count = 0; 848 849 genpd_unlock(genpd); 850 851 ret = pm_generic_prepare(dev); 852 if (ret) { 853 genpd_lock(genpd); 854 855 genpd->prepared_count--; 856 857 genpd_unlock(genpd); 858 } 859 860 return ret; 861 } 862 863 /** 864 * pm_genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain. 865 * @dev: Device to suspend. 866 * 867 * Stop the device and remove power from the domain if all devices in it have 868 * been stopped. 869 */ 870 static int pm_genpd_suspend_noirq(struct device *dev) 871 { 872 struct generic_pm_domain *genpd; 873 int ret; 874 875 dev_dbg(dev, "%s()\n", __func__); 876 877 genpd = dev_to_genpd(dev); 878 if (IS_ERR(genpd)) 879 return -EINVAL; 880 881 if (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)) 882 return 0; 883 884 if (genpd->dev_ops.stop && genpd->dev_ops.start) { 885 ret = pm_runtime_force_suspend(dev); 886 if (ret) 887 return ret; 888 } 889 890 /* 891 * Since all of the "noirq" callbacks are executed sequentially, it is 892 * guaranteed that this function will never run twice in parallel for 893 * the same PM domain, so it is not necessary to use locking here. 894 */ 895 genpd->suspended_count++; 896 genpd_sync_poweroff(genpd); 897 898 return 0; 899 } 900 901 /** 902 * pm_genpd_resume_noirq - Start of resume of device in an I/O PM domain. 903 * @dev: Device to resume. 904 * 905 * Restore power to the device's PM domain, if necessary, and start the device. 906 */ 907 static int pm_genpd_resume_noirq(struct device *dev) 908 { 909 struct generic_pm_domain *genpd; 910 int ret = 0; 911 912 dev_dbg(dev, "%s()\n", __func__); 913 914 genpd = dev_to_genpd(dev); 915 if (IS_ERR(genpd)) 916 return -EINVAL; 917 918 if (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)) 919 return 0; 920 921 /* 922 * Since all of the "noirq" callbacks are executed sequentially, it is 923 * guaranteed that this function will never run twice in parallel for 924 * the same PM domain, so it is not necessary to use locking here. 925 */ 926 genpd_sync_poweron(genpd); 927 genpd->suspended_count--; 928 929 if (genpd->dev_ops.stop && genpd->dev_ops.start) 930 ret = pm_runtime_force_resume(dev); 931 932 return ret; 933 } 934 935 /** 936 * pm_genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain. 937 * @dev: Device to freeze. 938 * 939 * Carry out a late freeze of a device under the assumption that its 940 * pm_domain field points to the domain member of an object of type 941 * struct generic_pm_domain representing a power domain consisting of I/O 942 * devices. 943 */ 944 static int pm_genpd_freeze_noirq(struct device *dev) 945 { 946 struct generic_pm_domain *genpd; 947 int ret = 0; 948 949 dev_dbg(dev, "%s()\n", __func__); 950 951 genpd = dev_to_genpd(dev); 952 if (IS_ERR(genpd)) 953 return -EINVAL; 954 955 if (genpd->dev_ops.stop && genpd->dev_ops.start) 956 ret = pm_runtime_force_suspend(dev); 957 958 return ret; 959 } 960 961 /** 962 * pm_genpd_thaw_noirq - Early thaw of device in an I/O PM domain. 963 * @dev: Device to thaw. 964 * 965 * Start the device, unless power has been removed from the domain already 966 * before the system transition. 967 */ 968 static int pm_genpd_thaw_noirq(struct device *dev) 969 { 970 struct generic_pm_domain *genpd; 971 int ret = 0; 972 973 dev_dbg(dev, "%s()\n", __func__); 974 975 genpd = dev_to_genpd(dev); 976 if (IS_ERR(genpd)) 977 return -EINVAL; 978 979 if (genpd->dev_ops.stop && genpd->dev_ops.start) 980 ret = pm_runtime_force_resume(dev); 981 982 return ret; 983 } 984 985 /** 986 * pm_genpd_restore_noirq - Start of restore of device in an I/O PM domain. 987 * @dev: Device to resume. 988 * 989 * Make sure the domain will be in the same power state as before the 990 * hibernation the system is resuming from and start the device if necessary. 991 */ 992 static int pm_genpd_restore_noirq(struct device *dev) 993 { 994 struct generic_pm_domain *genpd; 995 int ret = 0; 996 997 dev_dbg(dev, "%s()\n", __func__); 998 999 genpd = dev_to_genpd(dev); 1000 if (IS_ERR(genpd)) 1001 return -EINVAL; 1002 1003 /* 1004 * Since all of the "noirq" callbacks are executed sequentially, it is 1005 * guaranteed that this function will never run twice in parallel for 1006 * the same PM domain, so it is not necessary to use locking here. 1007 * 1008 * At this point suspended_count == 0 means we are being run for the 1009 * first time for the given domain in the present cycle. 1010 */ 1011 if (genpd->suspended_count++ == 0) 1012 /* 1013 * The boot kernel might put the domain into arbitrary state, 1014 * so make it appear as powered off to genpd_sync_poweron(), 1015 * so that it tries to power it on in case it was really off. 1016 */ 1017 genpd->status = GPD_STATE_POWER_OFF; 1018 1019 genpd_sync_poweron(genpd); 1020 1021 if (genpd->dev_ops.stop && genpd->dev_ops.start) 1022 ret = pm_runtime_force_resume(dev); 1023 1024 return ret; 1025 } 1026 1027 /** 1028 * pm_genpd_complete - Complete power transition of a device in a power domain. 1029 * @dev: Device to complete the transition of. 1030 * 1031 * Complete a power transition of a device (during a system-wide power 1032 * transition) under the assumption that its pm_domain field points to the 1033 * domain member of an object of type struct generic_pm_domain representing 1034 * a power domain consisting of I/O devices. 1035 */ 1036 static void pm_genpd_complete(struct device *dev) 1037 { 1038 struct generic_pm_domain *genpd; 1039 1040 dev_dbg(dev, "%s()\n", __func__); 1041 1042 genpd = dev_to_genpd(dev); 1043 if (IS_ERR(genpd)) 1044 return; 1045 1046 pm_generic_complete(dev); 1047 1048 genpd_lock(genpd); 1049 1050 genpd->prepared_count--; 1051 if (!genpd->prepared_count) 1052 genpd_queue_power_off_work(genpd); 1053 1054 genpd_unlock(genpd); 1055 } 1056 1057 /** 1058 * genpd_syscore_switch - Switch power during system core suspend or resume. 1059 * @dev: Device that normally is marked as "always on" to switch power for. 1060 * 1061 * This routine may only be called during the system core (syscore) suspend or 1062 * resume phase for devices whose "always on" flags are set. 1063 */ 1064 static void genpd_syscore_switch(struct device *dev, bool suspend) 1065 { 1066 struct generic_pm_domain *genpd; 1067 1068 genpd = dev_to_genpd(dev); 1069 if (!pm_genpd_present(genpd)) 1070 return; 1071 1072 if (suspend) { 1073 genpd->suspended_count++; 1074 genpd_sync_poweroff(genpd); 1075 } else { 1076 genpd_sync_poweron(genpd); 1077 genpd->suspended_count--; 1078 } 1079 } 1080 1081 void pm_genpd_syscore_poweroff(struct device *dev) 1082 { 1083 genpd_syscore_switch(dev, true); 1084 } 1085 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweroff); 1086 1087 void pm_genpd_syscore_poweron(struct device *dev) 1088 { 1089 genpd_syscore_switch(dev, false); 1090 } 1091 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron); 1092 1093 #else /* !CONFIG_PM_SLEEP */ 1094 1095 #define pm_genpd_prepare NULL 1096 #define pm_genpd_suspend_noirq NULL 1097 #define pm_genpd_resume_noirq NULL 1098 #define pm_genpd_freeze_noirq NULL 1099 #define pm_genpd_thaw_noirq NULL 1100 #define pm_genpd_restore_noirq NULL 1101 #define pm_genpd_complete NULL 1102 1103 #endif /* CONFIG_PM_SLEEP */ 1104 1105 static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev, 1106 struct generic_pm_domain *genpd, 1107 struct gpd_timing_data *td) 1108 { 1109 struct generic_pm_domain_data *gpd_data; 1110 int ret; 1111 1112 ret = dev_pm_get_subsys_data(dev); 1113 if (ret) 1114 return ERR_PTR(ret); 1115 1116 gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL); 1117 if (!gpd_data) { 1118 ret = -ENOMEM; 1119 goto err_put; 1120 } 1121 1122 if (td) 1123 gpd_data->td = *td; 1124 1125 gpd_data->base.dev = dev; 1126 gpd_data->td.constraint_changed = true; 1127 gpd_data->td.effective_constraint_ns = -1; 1128 gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier; 1129 1130 spin_lock_irq(&dev->power.lock); 1131 1132 if (dev->power.subsys_data->domain_data) { 1133 ret = -EINVAL; 1134 goto err_free; 1135 } 1136 1137 dev->power.subsys_data->domain_data = &gpd_data->base; 1138 1139 spin_unlock_irq(&dev->power.lock); 1140 1141 dev_pm_domain_set(dev, &genpd->domain); 1142 1143 return gpd_data; 1144 1145 err_free: 1146 spin_unlock_irq(&dev->power.lock); 1147 kfree(gpd_data); 1148 err_put: 1149 dev_pm_put_subsys_data(dev); 1150 return ERR_PTR(ret); 1151 } 1152 1153 static void genpd_free_dev_data(struct device *dev, 1154 struct generic_pm_domain_data *gpd_data) 1155 { 1156 dev_pm_domain_set(dev, NULL); 1157 1158 spin_lock_irq(&dev->power.lock); 1159 1160 dev->power.subsys_data->domain_data = NULL; 1161 1162 spin_unlock_irq(&dev->power.lock); 1163 1164 kfree(gpd_data); 1165 dev_pm_put_subsys_data(dev); 1166 } 1167 1168 static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, 1169 struct gpd_timing_data *td) 1170 { 1171 struct generic_pm_domain_data *gpd_data; 1172 int ret = 0; 1173 1174 dev_dbg(dev, "%s()\n", __func__); 1175 1176 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)) 1177 return -EINVAL; 1178 1179 gpd_data = genpd_alloc_dev_data(dev, genpd, td); 1180 if (IS_ERR(gpd_data)) 1181 return PTR_ERR(gpd_data); 1182 1183 genpd_lock(genpd); 1184 1185 if (genpd->prepared_count > 0) { 1186 ret = -EAGAIN; 1187 goto out; 1188 } 1189 1190 ret = genpd->attach_dev ? genpd->attach_dev(genpd, dev) : 0; 1191 if (ret) 1192 goto out; 1193 1194 genpd->device_count++; 1195 genpd->max_off_time_changed = true; 1196 1197 list_add_tail(&gpd_data->base.list_node, &genpd->dev_list); 1198 1199 out: 1200 genpd_unlock(genpd); 1201 1202 if (ret) 1203 genpd_free_dev_data(dev, gpd_data); 1204 else 1205 dev_pm_qos_add_notifier(dev, &gpd_data->nb); 1206 1207 return ret; 1208 } 1209 1210 /** 1211 * __pm_genpd_add_device - Add a device to an I/O PM domain. 1212 * @genpd: PM domain to add the device to. 1213 * @dev: Device to be added. 1214 * @td: Set of PM QoS timing parameters to attach to the device. 1215 */ 1216 int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev, 1217 struct gpd_timing_data *td) 1218 { 1219 int ret; 1220 1221 mutex_lock(&gpd_list_lock); 1222 ret = genpd_add_device(genpd, dev, td); 1223 mutex_unlock(&gpd_list_lock); 1224 1225 return ret; 1226 } 1227 EXPORT_SYMBOL_GPL(__pm_genpd_add_device); 1228 1229 static int genpd_remove_device(struct generic_pm_domain *genpd, 1230 struct device *dev) 1231 { 1232 struct generic_pm_domain_data *gpd_data; 1233 struct pm_domain_data *pdd; 1234 int ret = 0; 1235 1236 dev_dbg(dev, "%s()\n", __func__); 1237 1238 pdd = dev->power.subsys_data->domain_data; 1239 gpd_data = to_gpd_data(pdd); 1240 dev_pm_qos_remove_notifier(dev, &gpd_data->nb); 1241 1242 genpd_lock(genpd); 1243 1244 if (genpd->prepared_count > 0) { 1245 ret = -EAGAIN; 1246 goto out; 1247 } 1248 1249 genpd->device_count--; 1250 genpd->max_off_time_changed = true; 1251 1252 if (genpd->detach_dev) 1253 genpd->detach_dev(genpd, dev); 1254 1255 list_del_init(&pdd->list_node); 1256 1257 genpd_unlock(genpd); 1258 1259 genpd_free_dev_data(dev, gpd_data); 1260 1261 return 0; 1262 1263 out: 1264 genpd_unlock(genpd); 1265 dev_pm_qos_add_notifier(dev, &gpd_data->nb); 1266 1267 return ret; 1268 } 1269 1270 /** 1271 * pm_genpd_remove_device - Remove a device from an I/O PM domain. 1272 * @genpd: PM domain to remove the device from. 1273 * @dev: Device to be removed. 1274 */ 1275 int pm_genpd_remove_device(struct generic_pm_domain *genpd, 1276 struct device *dev) 1277 { 1278 if (!genpd || genpd != genpd_lookup_dev(dev)) 1279 return -EINVAL; 1280 1281 return genpd_remove_device(genpd, dev); 1282 } 1283 EXPORT_SYMBOL_GPL(pm_genpd_remove_device); 1284 1285 static int genpd_add_subdomain(struct generic_pm_domain *genpd, 1286 struct generic_pm_domain *subdomain) 1287 { 1288 struct gpd_link *link, *itr; 1289 int ret = 0; 1290 1291 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain) 1292 || genpd == subdomain) 1293 return -EINVAL; 1294 1295 /* 1296 * If the domain can be powered on/off in an IRQ safe 1297 * context, ensure that the subdomain can also be 1298 * powered on/off in that context. 1299 */ 1300 if (!genpd_is_irq_safe(genpd) && genpd_is_irq_safe(subdomain)) { 1301 WARN(1, "Parent %s of subdomain %s must be IRQ safe\n", 1302 genpd->name, subdomain->name); 1303 return -EINVAL; 1304 } 1305 1306 link = kzalloc(sizeof(*link), GFP_KERNEL); 1307 if (!link) 1308 return -ENOMEM; 1309 1310 genpd_lock(subdomain); 1311 genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING); 1312 1313 if (genpd->status == GPD_STATE_POWER_OFF 1314 && subdomain->status != GPD_STATE_POWER_OFF) { 1315 ret = -EINVAL; 1316 goto out; 1317 } 1318 1319 list_for_each_entry(itr, &genpd->master_links, master_node) { 1320 if (itr->slave == subdomain && itr->master == genpd) { 1321 ret = -EINVAL; 1322 goto out; 1323 } 1324 } 1325 1326 link->master = genpd; 1327 list_add_tail(&link->master_node, &genpd->master_links); 1328 link->slave = subdomain; 1329 list_add_tail(&link->slave_node, &subdomain->slave_links); 1330 if (subdomain->status != GPD_STATE_POWER_OFF) 1331 genpd_sd_counter_inc(genpd); 1332 1333 out: 1334 genpd_unlock(genpd); 1335 genpd_unlock(subdomain); 1336 if (ret) 1337 kfree(link); 1338 return ret; 1339 } 1340 1341 /** 1342 * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain. 1343 * @genpd: Master PM domain to add the subdomain to. 1344 * @subdomain: Subdomain to be added. 1345 */ 1346 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd, 1347 struct generic_pm_domain *subdomain) 1348 { 1349 int ret; 1350 1351 mutex_lock(&gpd_list_lock); 1352 ret = genpd_add_subdomain(genpd, subdomain); 1353 mutex_unlock(&gpd_list_lock); 1354 1355 return ret; 1356 } 1357 EXPORT_SYMBOL_GPL(pm_genpd_add_subdomain); 1358 1359 /** 1360 * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain. 1361 * @genpd: Master PM domain to remove the subdomain from. 1362 * @subdomain: Subdomain to be removed. 1363 */ 1364 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd, 1365 struct generic_pm_domain *subdomain) 1366 { 1367 struct gpd_link *link; 1368 int ret = -EINVAL; 1369 1370 if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)) 1371 return -EINVAL; 1372 1373 genpd_lock(subdomain); 1374 genpd_lock_nested(genpd, SINGLE_DEPTH_NESTING); 1375 1376 if (!list_empty(&subdomain->master_links) || subdomain->device_count) { 1377 pr_warn("%s: unable to remove subdomain %s\n", genpd->name, 1378 subdomain->name); 1379 ret = -EBUSY; 1380 goto out; 1381 } 1382 1383 list_for_each_entry(link, &genpd->master_links, master_node) { 1384 if (link->slave != subdomain) 1385 continue; 1386 1387 list_del(&link->master_node); 1388 list_del(&link->slave_node); 1389 kfree(link); 1390 if (subdomain->status != GPD_STATE_POWER_OFF) 1391 genpd_sd_counter_dec(genpd); 1392 1393 ret = 0; 1394 break; 1395 } 1396 1397 out: 1398 genpd_unlock(genpd); 1399 genpd_unlock(subdomain); 1400 1401 return ret; 1402 } 1403 EXPORT_SYMBOL_GPL(pm_genpd_remove_subdomain); 1404 1405 static int genpd_set_default_power_state(struct generic_pm_domain *genpd) 1406 { 1407 struct genpd_power_state *state; 1408 1409 state = kzalloc(sizeof(*state), GFP_KERNEL); 1410 if (!state) 1411 return -ENOMEM; 1412 1413 genpd->states = state; 1414 genpd->state_count = 1; 1415 genpd->free = state; 1416 1417 return 0; 1418 } 1419 1420 static void genpd_lock_init(struct generic_pm_domain *genpd) 1421 { 1422 if (genpd->flags & GENPD_FLAG_IRQ_SAFE) { 1423 spin_lock_init(&genpd->slock); 1424 genpd->lock_ops = &genpd_spin_ops; 1425 } else { 1426 mutex_init(&genpd->mlock); 1427 genpd->lock_ops = &genpd_mtx_ops; 1428 } 1429 } 1430 1431 /** 1432 * pm_genpd_init - Initialize a generic I/O PM domain object. 1433 * @genpd: PM domain object to initialize. 1434 * @gov: PM domain governor to associate with the domain (may be NULL). 1435 * @is_off: Initial value of the domain's power_is_off field. 1436 * 1437 * Returns 0 on successful initialization, else a negative error code. 1438 */ 1439 int pm_genpd_init(struct generic_pm_domain *genpd, 1440 struct dev_power_governor *gov, bool is_off) 1441 { 1442 int ret; 1443 1444 if (IS_ERR_OR_NULL(genpd)) 1445 return -EINVAL; 1446 1447 INIT_LIST_HEAD(&genpd->master_links); 1448 INIT_LIST_HEAD(&genpd->slave_links); 1449 INIT_LIST_HEAD(&genpd->dev_list); 1450 genpd_lock_init(genpd); 1451 genpd->gov = gov; 1452 INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn); 1453 atomic_set(&genpd->sd_count, 0); 1454 genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE; 1455 genpd->device_count = 0; 1456 genpd->max_off_time_ns = -1; 1457 genpd->max_off_time_changed = true; 1458 genpd->provider = NULL; 1459 genpd->has_provider = false; 1460 genpd->domain.ops.runtime_suspend = genpd_runtime_suspend; 1461 genpd->domain.ops.runtime_resume = genpd_runtime_resume; 1462 genpd->domain.ops.prepare = pm_genpd_prepare; 1463 genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq; 1464 genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq; 1465 genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq; 1466 genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq; 1467 genpd->domain.ops.poweroff_noirq = pm_genpd_suspend_noirq; 1468 genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq; 1469 genpd->domain.ops.complete = pm_genpd_complete; 1470 1471 if (genpd->flags & GENPD_FLAG_PM_CLK) { 1472 genpd->dev_ops.stop = pm_clk_suspend; 1473 genpd->dev_ops.start = pm_clk_resume; 1474 } 1475 1476 /* Use only one "off" state if there were no states declared */ 1477 if (genpd->state_count == 0) { 1478 ret = genpd_set_default_power_state(genpd); 1479 if (ret) 1480 return ret; 1481 } 1482 1483 mutex_lock(&gpd_list_lock); 1484 list_add(&genpd->gpd_list_node, &gpd_list); 1485 mutex_unlock(&gpd_list_lock); 1486 1487 return 0; 1488 } 1489 EXPORT_SYMBOL_GPL(pm_genpd_init); 1490 1491 static int genpd_remove(struct generic_pm_domain *genpd) 1492 { 1493 struct gpd_link *l, *link; 1494 1495 if (IS_ERR_OR_NULL(genpd)) 1496 return -EINVAL; 1497 1498 genpd_lock(genpd); 1499 1500 if (genpd->has_provider) { 1501 genpd_unlock(genpd); 1502 pr_err("Provider present, unable to remove %s\n", genpd->name); 1503 return -EBUSY; 1504 } 1505 1506 if (!list_empty(&genpd->master_links) || genpd->device_count) { 1507 genpd_unlock(genpd); 1508 pr_err("%s: unable to remove %s\n", __func__, genpd->name); 1509 return -EBUSY; 1510 } 1511 1512 list_for_each_entry_safe(link, l, &genpd->slave_links, slave_node) { 1513 list_del(&link->master_node); 1514 list_del(&link->slave_node); 1515 kfree(link); 1516 } 1517 1518 list_del(&genpd->gpd_list_node); 1519 genpd_unlock(genpd); 1520 cancel_work_sync(&genpd->power_off_work); 1521 kfree(genpd->free); 1522 pr_debug("%s: removed %s\n", __func__, genpd->name); 1523 1524 return 0; 1525 } 1526 1527 /** 1528 * pm_genpd_remove - Remove a generic I/O PM domain 1529 * @genpd: Pointer to PM domain that is to be removed. 1530 * 1531 * To remove the PM domain, this function: 1532 * - Removes the PM domain as a subdomain to any parent domains, 1533 * if it was added. 1534 * - Removes the PM domain from the list of registered PM domains. 1535 * 1536 * The PM domain will only be removed, if the associated provider has 1537 * been removed, it is not a parent to any other PM domain and has no 1538 * devices associated with it. 1539 */ 1540 int pm_genpd_remove(struct generic_pm_domain *genpd) 1541 { 1542 int ret; 1543 1544 mutex_lock(&gpd_list_lock); 1545 ret = genpd_remove(genpd); 1546 mutex_unlock(&gpd_list_lock); 1547 1548 return ret; 1549 } 1550 EXPORT_SYMBOL_GPL(pm_genpd_remove); 1551 1552 #ifdef CONFIG_PM_GENERIC_DOMAINS_OF 1553 1554 typedef struct generic_pm_domain *(*genpd_xlate_t)(struct of_phandle_args *args, 1555 void *data); 1556 1557 /* 1558 * Device Tree based PM domain providers. 1559 * 1560 * The code below implements generic device tree based PM domain providers that 1561 * bind device tree nodes with generic PM domains registered in the system. 1562 * 1563 * Any driver that registers generic PM domains and needs to support binding of 1564 * devices to these domains is supposed to register a PM domain provider, which 1565 * maps a PM domain specifier retrieved from the device tree to a PM domain. 1566 * 1567 * Two simple mapping functions have been provided for convenience: 1568 * - genpd_xlate_simple() for 1:1 device tree node to PM domain mapping. 1569 * - genpd_xlate_onecell() for mapping of multiple PM domains per node by 1570 * index. 1571 */ 1572 1573 /** 1574 * struct of_genpd_provider - PM domain provider registration structure 1575 * @link: Entry in global list of PM domain providers 1576 * @node: Pointer to device tree node of PM domain provider 1577 * @xlate: Provider-specific xlate callback mapping a set of specifier cells 1578 * into a PM domain. 1579 * @data: context pointer to be passed into @xlate callback 1580 */ 1581 struct of_genpd_provider { 1582 struct list_head link; 1583 struct device_node *node; 1584 genpd_xlate_t xlate; 1585 void *data; 1586 }; 1587 1588 /* List of registered PM domain providers. */ 1589 static LIST_HEAD(of_genpd_providers); 1590 /* Mutex to protect the list above. */ 1591 static DEFINE_MUTEX(of_genpd_mutex); 1592 1593 /** 1594 * genpd_xlate_simple() - Xlate function for direct node-domain mapping 1595 * @genpdspec: OF phandle args to map into a PM domain 1596 * @data: xlate function private data - pointer to struct generic_pm_domain 1597 * 1598 * This is a generic xlate function that can be used to model PM domains that 1599 * have their own device tree nodes. The private data of xlate function needs 1600 * to be a valid pointer to struct generic_pm_domain. 1601 */ 1602 static struct generic_pm_domain *genpd_xlate_simple( 1603 struct of_phandle_args *genpdspec, 1604 void *data) 1605 { 1606 if (genpdspec->args_count != 0) 1607 return ERR_PTR(-EINVAL); 1608 return data; 1609 } 1610 1611 /** 1612 * genpd_xlate_onecell() - Xlate function using a single index. 1613 * @genpdspec: OF phandle args to map into a PM domain 1614 * @data: xlate function private data - pointer to struct genpd_onecell_data 1615 * 1616 * This is a generic xlate function that can be used to model simple PM domain 1617 * controllers that have one device tree node and provide multiple PM domains. 1618 * A single cell is used as an index into an array of PM domains specified in 1619 * the genpd_onecell_data struct when registering the provider. 1620 */ 1621 static struct generic_pm_domain *genpd_xlate_onecell( 1622 struct of_phandle_args *genpdspec, 1623 void *data) 1624 { 1625 struct genpd_onecell_data *genpd_data = data; 1626 unsigned int idx = genpdspec->args[0]; 1627 1628 if (genpdspec->args_count != 1) 1629 return ERR_PTR(-EINVAL); 1630 1631 if (idx >= genpd_data->num_domains) { 1632 pr_err("%s: invalid domain index %u\n", __func__, idx); 1633 return ERR_PTR(-EINVAL); 1634 } 1635 1636 if (!genpd_data->domains[idx]) 1637 return ERR_PTR(-ENOENT); 1638 1639 return genpd_data->domains[idx]; 1640 } 1641 1642 /** 1643 * genpd_add_provider() - Register a PM domain provider for a node 1644 * @np: Device node pointer associated with the PM domain provider. 1645 * @xlate: Callback for decoding PM domain from phandle arguments. 1646 * @data: Context pointer for @xlate callback. 1647 */ 1648 static int genpd_add_provider(struct device_node *np, genpd_xlate_t xlate, 1649 void *data) 1650 { 1651 struct of_genpd_provider *cp; 1652 1653 cp = kzalloc(sizeof(*cp), GFP_KERNEL); 1654 if (!cp) 1655 return -ENOMEM; 1656 1657 cp->node = of_node_get(np); 1658 cp->data = data; 1659 cp->xlate = xlate; 1660 1661 mutex_lock(&of_genpd_mutex); 1662 list_add(&cp->link, &of_genpd_providers); 1663 mutex_unlock(&of_genpd_mutex); 1664 pr_debug("Added domain provider from %s\n", np->full_name); 1665 1666 return 0; 1667 } 1668 1669 /** 1670 * of_genpd_add_provider_simple() - Register a simple PM domain provider 1671 * @np: Device node pointer associated with the PM domain provider. 1672 * @genpd: Pointer to PM domain associated with the PM domain provider. 1673 */ 1674 int of_genpd_add_provider_simple(struct device_node *np, 1675 struct generic_pm_domain *genpd) 1676 { 1677 int ret = -EINVAL; 1678 1679 if (!np || !genpd) 1680 return -EINVAL; 1681 1682 mutex_lock(&gpd_list_lock); 1683 1684 if (pm_genpd_present(genpd)) 1685 ret = genpd_add_provider(np, genpd_xlate_simple, genpd); 1686 1687 if (!ret) { 1688 genpd->provider = &np->fwnode; 1689 genpd->has_provider = true; 1690 } 1691 1692 mutex_unlock(&gpd_list_lock); 1693 1694 return ret; 1695 } 1696 EXPORT_SYMBOL_GPL(of_genpd_add_provider_simple); 1697 1698 /** 1699 * of_genpd_add_provider_onecell() - Register a onecell PM domain provider 1700 * @np: Device node pointer associated with the PM domain provider. 1701 * @data: Pointer to the data associated with the PM domain provider. 1702 */ 1703 int of_genpd_add_provider_onecell(struct device_node *np, 1704 struct genpd_onecell_data *data) 1705 { 1706 unsigned int i; 1707 int ret = -EINVAL; 1708 1709 if (!np || !data) 1710 return -EINVAL; 1711 1712 mutex_lock(&gpd_list_lock); 1713 1714 for (i = 0; i < data->num_domains; i++) { 1715 if (!data->domains[i]) 1716 continue; 1717 if (!pm_genpd_present(data->domains[i])) 1718 goto error; 1719 1720 data->domains[i]->provider = &np->fwnode; 1721 data->domains[i]->has_provider = true; 1722 } 1723 1724 ret = genpd_add_provider(np, genpd_xlate_onecell, data); 1725 if (ret < 0) 1726 goto error; 1727 1728 mutex_unlock(&gpd_list_lock); 1729 1730 return 0; 1731 1732 error: 1733 while (i--) { 1734 if (!data->domains[i]) 1735 continue; 1736 data->domains[i]->provider = NULL; 1737 data->domains[i]->has_provider = false; 1738 } 1739 1740 mutex_unlock(&gpd_list_lock); 1741 1742 return ret; 1743 } 1744 EXPORT_SYMBOL_GPL(of_genpd_add_provider_onecell); 1745 1746 /** 1747 * of_genpd_del_provider() - Remove a previously registered PM domain provider 1748 * @np: Device node pointer associated with the PM domain provider 1749 */ 1750 void of_genpd_del_provider(struct device_node *np) 1751 { 1752 struct of_genpd_provider *cp; 1753 struct generic_pm_domain *gpd; 1754 1755 mutex_lock(&gpd_list_lock); 1756 mutex_lock(&of_genpd_mutex); 1757 list_for_each_entry(cp, &of_genpd_providers, link) { 1758 if (cp->node == np) { 1759 /* 1760 * For each PM domain associated with the 1761 * provider, set the 'has_provider' to false 1762 * so that the PM domain can be safely removed. 1763 */ 1764 list_for_each_entry(gpd, &gpd_list, gpd_list_node) 1765 if (gpd->provider == &np->fwnode) 1766 gpd->has_provider = false; 1767 1768 list_del(&cp->link); 1769 of_node_put(cp->node); 1770 kfree(cp); 1771 break; 1772 } 1773 } 1774 mutex_unlock(&of_genpd_mutex); 1775 mutex_unlock(&gpd_list_lock); 1776 } 1777 EXPORT_SYMBOL_GPL(of_genpd_del_provider); 1778 1779 /** 1780 * genpd_get_from_provider() - Look-up PM domain 1781 * @genpdspec: OF phandle args to use for look-up 1782 * 1783 * Looks for a PM domain provider under the node specified by @genpdspec and if 1784 * found, uses xlate function of the provider to map phandle args to a PM 1785 * domain. 1786 * 1787 * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR() 1788 * on failure. 1789 */ 1790 static struct generic_pm_domain *genpd_get_from_provider( 1791 struct of_phandle_args *genpdspec) 1792 { 1793 struct generic_pm_domain *genpd = ERR_PTR(-ENOENT); 1794 struct of_genpd_provider *provider; 1795 1796 if (!genpdspec) 1797 return ERR_PTR(-EINVAL); 1798 1799 mutex_lock(&of_genpd_mutex); 1800 1801 /* Check if we have such a provider in our array */ 1802 list_for_each_entry(provider, &of_genpd_providers, link) { 1803 if (provider->node == genpdspec->np) 1804 genpd = provider->xlate(genpdspec, provider->data); 1805 if (!IS_ERR(genpd)) 1806 break; 1807 } 1808 1809 mutex_unlock(&of_genpd_mutex); 1810 1811 return genpd; 1812 } 1813 1814 /** 1815 * of_genpd_add_device() - Add a device to an I/O PM domain 1816 * @genpdspec: OF phandle args to use for look-up PM domain 1817 * @dev: Device to be added. 1818 * 1819 * Looks-up an I/O PM domain based upon phandle args provided and adds 1820 * the device to the PM domain. Returns a negative error code on failure. 1821 */ 1822 int of_genpd_add_device(struct of_phandle_args *genpdspec, struct device *dev) 1823 { 1824 struct generic_pm_domain *genpd; 1825 int ret; 1826 1827 mutex_lock(&gpd_list_lock); 1828 1829 genpd = genpd_get_from_provider(genpdspec); 1830 if (IS_ERR(genpd)) { 1831 ret = PTR_ERR(genpd); 1832 goto out; 1833 } 1834 1835 ret = genpd_add_device(genpd, dev, NULL); 1836 1837 out: 1838 mutex_unlock(&gpd_list_lock); 1839 1840 return ret; 1841 } 1842 EXPORT_SYMBOL_GPL(of_genpd_add_device); 1843 1844 /** 1845 * of_genpd_add_subdomain - Add a subdomain to an I/O PM domain. 1846 * @parent_spec: OF phandle args to use for parent PM domain look-up 1847 * @subdomain_spec: OF phandle args to use for subdomain look-up 1848 * 1849 * Looks-up a parent PM domain and subdomain based upon phandle args 1850 * provided and adds the subdomain to the parent PM domain. Returns a 1851 * negative error code on failure. 1852 */ 1853 int of_genpd_add_subdomain(struct of_phandle_args *parent_spec, 1854 struct of_phandle_args *subdomain_spec) 1855 { 1856 struct generic_pm_domain *parent, *subdomain; 1857 int ret; 1858 1859 mutex_lock(&gpd_list_lock); 1860 1861 parent = genpd_get_from_provider(parent_spec); 1862 if (IS_ERR(parent)) { 1863 ret = PTR_ERR(parent); 1864 goto out; 1865 } 1866 1867 subdomain = genpd_get_from_provider(subdomain_spec); 1868 if (IS_ERR(subdomain)) { 1869 ret = PTR_ERR(subdomain); 1870 goto out; 1871 } 1872 1873 ret = genpd_add_subdomain(parent, subdomain); 1874 1875 out: 1876 mutex_unlock(&gpd_list_lock); 1877 1878 return ret; 1879 } 1880 EXPORT_SYMBOL_GPL(of_genpd_add_subdomain); 1881 1882 /** 1883 * of_genpd_remove_last - Remove the last PM domain registered for a provider 1884 * @provider: Pointer to device structure associated with provider 1885 * 1886 * Find the last PM domain that was added by a particular provider and 1887 * remove this PM domain from the list of PM domains. The provider is 1888 * identified by the 'provider' device structure that is passed. The PM 1889 * domain will only be removed, if the provider associated with domain 1890 * has been removed. 1891 * 1892 * Returns a valid pointer to struct generic_pm_domain on success or 1893 * ERR_PTR() on failure. 1894 */ 1895 struct generic_pm_domain *of_genpd_remove_last(struct device_node *np) 1896 { 1897 struct generic_pm_domain *gpd, *genpd = ERR_PTR(-ENOENT); 1898 int ret; 1899 1900 if (IS_ERR_OR_NULL(np)) 1901 return ERR_PTR(-EINVAL); 1902 1903 mutex_lock(&gpd_list_lock); 1904 list_for_each_entry(gpd, &gpd_list, gpd_list_node) { 1905 if (gpd->provider == &np->fwnode) { 1906 ret = genpd_remove(gpd); 1907 genpd = ret ? ERR_PTR(ret) : gpd; 1908 break; 1909 } 1910 } 1911 mutex_unlock(&gpd_list_lock); 1912 1913 return genpd; 1914 } 1915 EXPORT_SYMBOL_GPL(of_genpd_remove_last); 1916 1917 /** 1918 * genpd_dev_pm_detach - Detach a device from its PM domain. 1919 * @dev: Device to detach. 1920 * @power_off: Currently not used 1921 * 1922 * Try to locate a corresponding generic PM domain, which the device was 1923 * attached to previously. If such is found, the device is detached from it. 1924 */ 1925 static void genpd_dev_pm_detach(struct device *dev, bool power_off) 1926 { 1927 struct generic_pm_domain *pd; 1928 unsigned int i; 1929 int ret = 0; 1930 1931 pd = dev_to_genpd(dev); 1932 if (IS_ERR(pd)) 1933 return; 1934 1935 dev_dbg(dev, "removing from PM domain %s\n", pd->name); 1936 1937 for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) { 1938 ret = genpd_remove_device(pd, dev); 1939 if (ret != -EAGAIN) 1940 break; 1941 1942 mdelay(i); 1943 cond_resched(); 1944 } 1945 1946 if (ret < 0) { 1947 dev_err(dev, "failed to remove from PM domain %s: %d", 1948 pd->name, ret); 1949 return; 1950 } 1951 1952 /* Check if PM domain can be powered off after removing this device. */ 1953 genpd_queue_power_off_work(pd); 1954 } 1955 1956 static void genpd_dev_pm_sync(struct device *dev) 1957 { 1958 struct generic_pm_domain *pd; 1959 1960 pd = dev_to_genpd(dev); 1961 if (IS_ERR(pd)) 1962 return; 1963 1964 genpd_queue_power_off_work(pd); 1965 } 1966 1967 /** 1968 * genpd_dev_pm_attach - Attach a device to its PM domain using DT. 1969 * @dev: Device to attach. 1970 * 1971 * Parse device's OF node to find a PM domain specifier. If such is found, 1972 * attaches the device to retrieved pm_domain ops. 1973 * 1974 * Both generic and legacy Samsung-specific DT bindings are supported to keep 1975 * backwards compatibility with existing DTBs. 1976 * 1977 * Returns 0 on successfully attached PM domain or negative error code. Note 1978 * that if a power-domain exists for the device, but it cannot be found or 1979 * turned on, then return -EPROBE_DEFER to ensure that the device is not 1980 * probed and to re-try again later. 1981 */ 1982 int genpd_dev_pm_attach(struct device *dev) 1983 { 1984 struct of_phandle_args pd_args; 1985 struct generic_pm_domain *pd; 1986 unsigned int i; 1987 int ret; 1988 1989 if (!dev->of_node) 1990 return -ENODEV; 1991 1992 if (dev->pm_domain) 1993 return -EEXIST; 1994 1995 ret = of_parse_phandle_with_args(dev->of_node, "power-domains", 1996 "#power-domain-cells", 0, &pd_args); 1997 if (ret < 0) { 1998 if (ret != -ENOENT) 1999 return ret; 2000 2001 /* 2002 * Try legacy Samsung-specific bindings 2003 * (for backwards compatibility of DT ABI) 2004 */ 2005 pd_args.args_count = 0; 2006 pd_args.np = of_parse_phandle(dev->of_node, 2007 "samsung,power-domain", 0); 2008 if (!pd_args.np) 2009 return -ENOENT; 2010 } 2011 2012 mutex_lock(&gpd_list_lock); 2013 pd = genpd_get_from_provider(&pd_args); 2014 of_node_put(pd_args.np); 2015 if (IS_ERR(pd)) { 2016 mutex_unlock(&gpd_list_lock); 2017 dev_dbg(dev, "%s() failed to find PM domain: %ld\n", 2018 __func__, PTR_ERR(pd)); 2019 return -EPROBE_DEFER; 2020 } 2021 2022 dev_dbg(dev, "adding to PM domain %s\n", pd->name); 2023 2024 for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) { 2025 ret = genpd_add_device(pd, dev, NULL); 2026 if (ret != -EAGAIN) 2027 break; 2028 2029 mdelay(i); 2030 cond_resched(); 2031 } 2032 mutex_unlock(&gpd_list_lock); 2033 2034 if (ret < 0) { 2035 if (ret != -EPROBE_DEFER) 2036 dev_err(dev, "failed to add to PM domain %s: %d", 2037 pd->name, ret); 2038 goto out; 2039 } 2040 2041 dev->pm_domain->detach = genpd_dev_pm_detach; 2042 dev->pm_domain->sync = genpd_dev_pm_sync; 2043 2044 genpd_lock(pd); 2045 ret = genpd_poweron(pd, 0); 2046 genpd_unlock(pd); 2047 out: 2048 return ret ? -EPROBE_DEFER : 0; 2049 } 2050 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach); 2051 2052 static const struct of_device_id idle_state_match[] = { 2053 { .compatible = "domain-idle-state", }, 2054 { } 2055 }; 2056 2057 static int genpd_parse_state(struct genpd_power_state *genpd_state, 2058 struct device_node *state_node) 2059 { 2060 int err; 2061 u32 residency; 2062 u32 entry_latency, exit_latency; 2063 const struct of_device_id *match_id; 2064 2065 match_id = of_match_node(idle_state_match, state_node); 2066 if (!match_id) 2067 return -EINVAL; 2068 2069 err = of_property_read_u32(state_node, "entry-latency-us", 2070 &entry_latency); 2071 if (err) { 2072 pr_debug(" * %s missing entry-latency-us property\n", 2073 state_node->full_name); 2074 return -EINVAL; 2075 } 2076 2077 err = of_property_read_u32(state_node, "exit-latency-us", 2078 &exit_latency); 2079 if (err) { 2080 pr_debug(" * %s missing exit-latency-us property\n", 2081 state_node->full_name); 2082 return -EINVAL; 2083 } 2084 2085 err = of_property_read_u32(state_node, "min-residency-us", &residency); 2086 if (!err) 2087 genpd_state->residency_ns = 1000 * residency; 2088 2089 genpd_state->power_on_latency_ns = 1000 * exit_latency; 2090 genpd_state->power_off_latency_ns = 1000 * entry_latency; 2091 genpd_state->fwnode = &state_node->fwnode; 2092 2093 return 0; 2094 } 2095 2096 /** 2097 * of_genpd_parse_idle_states: Return array of idle states for the genpd. 2098 * 2099 * @dn: The genpd device node 2100 * @states: The pointer to which the state array will be saved. 2101 * @n: The count of elements in the array returned from this function. 2102 * 2103 * Returns the device states parsed from the OF node. The memory for the states 2104 * is allocated by this function and is the responsibility of the caller to 2105 * free the memory after use. 2106 */ 2107 int of_genpd_parse_idle_states(struct device_node *dn, 2108 struct genpd_power_state **states, int *n) 2109 { 2110 struct genpd_power_state *st; 2111 struct device_node *np; 2112 int i = 0; 2113 int err, ret; 2114 int count; 2115 struct of_phandle_iterator it; 2116 2117 count = of_count_phandle_with_args(dn, "domain-idle-states", NULL); 2118 if (count <= 0) 2119 return -EINVAL; 2120 2121 st = kcalloc(count, sizeof(*st), GFP_KERNEL); 2122 if (!st) 2123 return -ENOMEM; 2124 2125 /* Loop over the phandles until all the requested entry is found */ 2126 of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) { 2127 np = it.node; 2128 ret = genpd_parse_state(&st[i++], np); 2129 if (ret) { 2130 pr_err 2131 ("Parsing idle state node %s failed with err %d\n", 2132 np->full_name, ret); 2133 of_node_put(np); 2134 kfree(st); 2135 return ret; 2136 } 2137 } 2138 2139 *n = count; 2140 *states = st; 2141 2142 return 0; 2143 } 2144 EXPORT_SYMBOL_GPL(of_genpd_parse_idle_states); 2145 2146 #endif /* CONFIG_PM_GENERIC_DOMAINS_OF */ 2147 2148 2149 /*** debugfs support ***/ 2150 2151 #ifdef CONFIG_DEBUG_FS 2152 #include <linux/pm.h> 2153 #include <linux/device.h> 2154 #include <linux/debugfs.h> 2155 #include <linux/seq_file.h> 2156 #include <linux/init.h> 2157 #include <linux/kobject.h> 2158 static struct dentry *pm_genpd_debugfs_dir; 2159 2160 /* 2161 * TODO: This function is a slightly modified version of rtpm_status_show 2162 * from sysfs.c, so generalize it. 2163 */ 2164 static void rtpm_status_str(struct seq_file *s, struct device *dev) 2165 { 2166 static const char * const status_lookup[] = { 2167 [RPM_ACTIVE] = "active", 2168 [RPM_RESUMING] = "resuming", 2169 [RPM_SUSPENDED] = "suspended", 2170 [RPM_SUSPENDING] = "suspending" 2171 }; 2172 const char *p = ""; 2173 2174 if (dev->power.runtime_error) 2175 p = "error"; 2176 else if (dev->power.disable_depth) 2177 p = "unsupported"; 2178 else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup)) 2179 p = status_lookup[dev->power.runtime_status]; 2180 else 2181 WARN_ON(1); 2182 2183 seq_puts(s, p); 2184 } 2185 2186 static int pm_genpd_summary_one(struct seq_file *s, 2187 struct generic_pm_domain *genpd) 2188 { 2189 static const char * const status_lookup[] = { 2190 [GPD_STATE_ACTIVE] = "on", 2191 [GPD_STATE_POWER_OFF] = "off" 2192 }; 2193 struct pm_domain_data *pm_data; 2194 const char *kobj_path; 2195 struct gpd_link *link; 2196 char state[16]; 2197 int ret; 2198 2199 ret = genpd_lock_interruptible(genpd); 2200 if (ret) 2201 return -ERESTARTSYS; 2202 2203 if (WARN_ON(genpd->status >= ARRAY_SIZE(status_lookup))) 2204 goto exit; 2205 if (genpd->status == GPD_STATE_POWER_OFF) 2206 snprintf(state, sizeof(state), "%s-%u", 2207 status_lookup[genpd->status], genpd->state_idx); 2208 else 2209 snprintf(state, sizeof(state), "%s", 2210 status_lookup[genpd->status]); 2211 seq_printf(s, "%-30s %-15s ", genpd->name, state); 2212 2213 /* 2214 * Modifications on the list require holding locks on both 2215 * master and slave, so we are safe. 2216 * Also genpd->name is immutable. 2217 */ 2218 list_for_each_entry(link, &genpd->master_links, master_node) { 2219 seq_printf(s, "%s", link->slave->name); 2220 if (!list_is_last(&link->master_node, &genpd->master_links)) 2221 seq_puts(s, ", "); 2222 } 2223 2224 list_for_each_entry(pm_data, &genpd->dev_list, list_node) { 2225 kobj_path = kobject_get_path(&pm_data->dev->kobj, 2226 genpd_is_irq_safe(genpd) ? 2227 GFP_ATOMIC : GFP_KERNEL); 2228 if (kobj_path == NULL) 2229 continue; 2230 2231 seq_printf(s, "\n %-50s ", kobj_path); 2232 rtpm_status_str(s, pm_data->dev); 2233 kfree(kobj_path); 2234 } 2235 2236 seq_puts(s, "\n"); 2237 exit: 2238 genpd_unlock(genpd); 2239 2240 return 0; 2241 } 2242 2243 static int pm_genpd_summary_show(struct seq_file *s, void *data) 2244 { 2245 struct generic_pm_domain *genpd; 2246 int ret = 0; 2247 2248 seq_puts(s, "domain status slaves\n"); 2249 seq_puts(s, " /device runtime status\n"); 2250 seq_puts(s, "----------------------------------------------------------------------\n"); 2251 2252 ret = mutex_lock_interruptible(&gpd_list_lock); 2253 if (ret) 2254 return -ERESTARTSYS; 2255 2256 list_for_each_entry(genpd, &gpd_list, gpd_list_node) { 2257 ret = pm_genpd_summary_one(s, genpd); 2258 if (ret) 2259 break; 2260 } 2261 mutex_unlock(&gpd_list_lock); 2262 2263 return ret; 2264 } 2265 2266 static int pm_genpd_summary_open(struct inode *inode, struct file *file) 2267 { 2268 return single_open(file, pm_genpd_summary_show, NULL); 2269 } 2270 2271 static const struct file_operations pm_genpd_summary_fops = { 2272 .open = pm_genpd_summary_open, 2273 .read = seq_read, 2274 .llseek = seq_lseek, 2275 .release = single_release, 2276 }; 2277 2278 static int __init pm_genpd_debug_init(void) 2279 { 2280 struct dentry *d; 2281 2282 pm_genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL); 2283 2284 if (!pm_genpd_debugfs_dir) 2285 return -ENOMEM; 2286 2287 d = debugfs_create_file("pm_genpd_summary", S_IRUGO, 2288 pm_genpd_debugfs_dir, NULL, &pm_genpd_summary_fops); 2289 if (!d) 2290 return -ENOMEM; 2291 2292 return 0; 2293 } 2294 late_initcall(pm_genpd_debug_init); 2295 2296 static void __exit pm_genpd_debug_exit(void) 2297 { 2298 debugfs_remove_recursive(pm_genpd_debugfs_dir); 2299 } 2300 __exitcall(pm_genpd_debug_exit); 2301 #endif /* CONFIG_DEBUG_FS */ 2302