drivers/base/power/domain.c

   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/kernel.h>
  10 #include <linux/io.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/pm_runtime.h>
  13 #include <linux/pm_domain.h>
  14 #include <linux/pm_qos.h>
  15 #include <linux/pm_clock.h>
  16 #include <linux/slab.h>
  17 #include <linux/err.h>
  18 #include <linux/sched.h>
  19 #include <linux/suspend.h>
  20 #include <linux/export.h>
  21
  22 #define GENPD_DEV_CALLBACK(genpd, type, callback, dev)          \
  23 ({                                                              \
  24         type (*__routine)(struct device *__d);                  \
  25         type __ret = (type)0;                                   \
  26                                                                 \
  27         __routine = genpd->dev_ops.callback;                    \
  28         if (__routine) {                                        \
  29                 __ret = __routine(dev);                         \
  30         }                                                       \
  31         __ret;                                                  \
  32 })
  33
  34 #define GENPD_DEV_TIMED_CALLBACK(genpd, type, callback, dev, field, name)       \
  35 ({                                                                              \
  36         ktime_t __start = ktime_get();                                          \
  37         type __retval = GENPD_DEV_CALLBACK(genpd, type, callback, dev);         \
  38         s64 __elapsed = ktime_to_ns(ktime_sub(ktime_get(), __start));           \
  39         struct gpd_timing_data *__td = &dev_gpd_data(dev)->td;                  \
  40         if (!__retval && __elapsed > __td->field) {                             \
  41                 __td->field = __elapsed;                                        \
  42                 dev_dbg(dev, name " latency exceeded, new value %lld ns\n",     \
  43                         __elapsed);                                             \
  44                 genpd->max_off_time_changed = true;                             \
  45                 __td->constraint_changed = true;                                \
  46         }                                                                       \
  47         __retval;                                                               \
  48 })
  49
  50 static LIST_HEAD(gpd_list);
  51 static DEFINE_MUTEX(gpd_list_lock);
  52
  53 static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
  54 {
  55         struct generic_pm_domain *genpd = NULL, *gpd;
  56
  57         if (IS_ERR_OR_NULL(domain_name))
  58                 return NULL;
  59
  60         mutex_lock(&gpd_list_lock);
  61         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
  62                 if (!strcmp(gpd->name, domain_name)) {
  63                         genpd = gpd;
  64                         break;
  65                 }
  66         }
  67         mutex_unlock(&gpd_list_lock);
  68         return genpd;
  69 }
  70
  71 struct generic_pm_domain *dev_to_genpd(struct device *dev)
  72 {
  73         if (IS_ERR_OR_NULL(dev->pm_domain))
  74                 return ERR_PTR(-EINVAL);
  75
  76         return pd_to_genpd(dev->pm_domain);
  77 }
  78
  79 static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev)
  80 {
  81         return GENPD_DEV_TIMED_CALLBACK(genpd, int, stop, dev,
  82                                         stop_latency_ns, "stop");
  83 }
  84
  85 static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev)
  86 {
  87         return GENPD_DEV_TIMED_CALLBACK(genpd, int, start, dev,
  88                                         start_latency_ns, "start");
  89 }
  90
  91 static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
  92 {
  93         bool ret = false;
  94
  95         if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
  96                 ret = !!atomic_dec_and_test(&genpd->sd_count);
  97
  98         return ret;
  99 }
 100
 101 static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
 102 {
 103         atomic_inc(&genpd->sd_count);
 104         smp_mb__after_atomic();
 105 }
 106
 107 static void genpd_acquire_lock(struct generic_pm_domain *genpd)
 108 {
 109         DEFINE_WAIT(wait);
 110
 111         mutex_lock(&genpd->lock);
 112         /*
 113          * Wait for the domain to transition into either the active,
 114          * or the power off state.
 115          */
 116         for (;;) {
 117                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 118                                 TASK_UNINTERRUPTIBLE);
 119                 if (genpd->status == GPD_STATE_ACTIVE
 120                     || genpd->status == GPD_STATE_POWER_OFF)
 121                         break;
 122                 mutex_unlock(&genpd->lock);
 123
 124                 schedule();
 125
 126                 mutex_lock(&genpd->lock);
 127         }
 128         finish_wait(&genpd->status_wait_queue, &wait);
 129 }
 130
 131 static void genpd_release_lock(struct generic_pm_domain *genpd)
 132 {
 133         mutex_unlock(&genpd->lock);
 134 }
 135
 136 static void genpd_set_active(struct generic_pm_domain *genpd)
 137 {
 138         if (genpd->resume_count == 0)
 139                 genpd->status = GPD_STATE_ACTIVE;
 140 }
 141
 142 static void genpd_recalc_cpu_exit_latency(struct generic_pm_domain *genpd)
 143 {
 144         s64 usecs64;
 145
 146         if (!genpd->cpuidle_data)
 147                 return;
 148
 149         usecs64 = genpd->power_on_latency_ns;
 150         do_div(usecs64, NSEC_PER_USEC);
 151         usecs64 += genpd->cpuidle_data->saved_exit_latency;
 152         genpd->cpuidle_data->idle_state->exit_latency = usecs64;
 153 }
 154
 155 static int genpd_power_on(struct generic_pm_domain *genpd)
 156 {
 157         ktime_t time_start;
 158         s64 elapsed_ns;
 159         int ret;
 160
 161         if (!genpd->power_on)
 162                 return 0;
 163
 164         time_start = ktime_get();
 165         ret = genpd->power_on(genpd);
 166         if (ret)
 167                 return ret;
 168
 169         elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 170         if (elapsed_ns <= genpd->power_on_latency_ns)
 171                 return ret;
 172
 173         genpd->power_on_latency_ns = elapsed_ns;
 174         genpd->max_off_time_changed = true;
 175         genpd_recalc_cpu_exit_latency(genpd);
 176         pr_warn("%s: Power-%s latency exceeded, new value %lld ns\n",
 177                 genpd->name, "on", elapsed_ns);
 178
 179         return ret;
 180 }
 181
 182 static int genpd_power_off(struct generic_pm_domain *genpd)
 183 {
 184         ktime_t time_start;
 185         s64 elapsed_ns;
 186         int ret;
 187
 188         if (!genpd->power_off)
 189                 return 0;
 190
 191         time_start = ktime_get();
 192         ret = genpd->power_off(genpd);
 193         if (ret == -EBUSY)
 194                 return ret;
 195
 196         elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 197         if (elapsed_ns <= genpd->power_off_latency_ns)
 198                 return ret;
 199
 200         genpd->power_off_latency_ns = elapsed_ns;
 201         genpd->max_off_time_changed = true;
 202         pr_warn("%s: Power-%s latency exceeded, new value %lld ns\n",
 203                 genpd->name, "off", elapsed_ns);
 204
 205         return ret;
 206 }
 207
 208 /**
 209  * __pm_genpd_poweron - Restore power to a given PM domain and its masters.
 210  * @genpd: PM domain to power up.
 211  *
 212  * Restore power to @genpd and all of its masters so that it is possible to
 213  * resume a device belonging to it.
 214  */
 215 static int __pm_genpd_poweron(struct generic_pm_domain *genpd)
 216         __releases(&genpd->lock) __acquires(&genpd->lock)
 217 {
 218         struct gpd_link *link;
 219         DEFINE_WAIT(wait);
 220         int ret = 0;
 221
 222         /* If the domain's master is being waited for, we have to wait too. */
 223         for (;;) {
 224                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 225                                 TASK_UNINTERRUPTIBLE);
 226                 if (genpd->status != GPD_STATE_WAIT_MASTER)
 227                         break;
 228                 mutex_unlock(&genpd->lock);
 229
 230                 schedule();
 231
 232                 mutex_lock(&genpd->lock);
 233         }
 234         finish_wait(&genpd->status_wait_queue, &wait);
 235
 236         if (genpd->status == GPD_STATE_ACTIVE
 237             || (genpd->prepared_count > 0 && genpd->suspend_power_off))
 238                 return 0;
 239
 240         if (genpd->status != GPD_STATE_POWER_OFF) {
 241                 genpd_set_active(genpd);
 242                 return 0;
 243         }
 244
 245         if (genpd->cpuidle_data) {
 246                 cpuidle_pause_and_lock();
 247                 genpd->cpuidle_data->idle_state->disabled = true;
 248                 cpuidle_resume_and_unlock();
 249                 goto out;
 250         }
 251
 252         /*
 253          * The list is guaranteed not to change while the loop below is being
 254          * executed, unless one of the masters' .power_on() callbacks fiddles
 255          * with it.
 256          */
 257         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 258                 genpd_sd_counter_inc(link->master);
 259                 genpd->status = GPD_STATE_WAIT_MASTER;
 260
 261                 mutex_unlock(&genpd->lock);
 262
 263                 ret = pm_genpd_poweron(link->master);
 264
 265                 mutex_lock(&genpd->lock);
 266
 267                 /*
 268                  * The "wait for parent" status is guaranteed not to change
 269                  * while the master is powering on.
 270                  */
 271                 genpd->status = GPD_STATE_POWER_OFF;
 272                 wake_up_all(&genpd->status_wait_queue);
 273                 if (ret) {
 274                         genpd_sd_counter_dec(link->master);
 275                         goto err;
 276                 }
 277         }
 278
 279         ret = genpd_power_on(genpd);
 280         if (ret)
 281                 goto err;
 282
 283  out:
 284         genpd_set_active(genpd);
 285
 286         return 0;
 287
 288  err:
 289         list_for_each_entry_continue_reverse(link, &genpd->slave_links, slave_node)
 290                 genpd_sd_counter_dec(link->master);
 291
 292         return ret;
 293 }
 294
 295 /**
 296  * pm_genpd_poweron - Restore power to a given PM domain and its masters.
 297  * @genpd: PM domain to power up.
 298  */
 299 int pm_genpd_poweron(struct generic_pm_domain *genpd)
 300 {
 301         int ret;
 302
 303         mutex_lock(&genpd->lock);
 304         ret = __pm_genpd_poweron(genpd);
 305         mutex_unlock(&genpd->lock);
 306         return ret;
 307 }
 308
 309 /**
 310  * pm_genpd_name_poweron - Restore power to a given PM domain and its masters.
 311  * @domain_name: Name of the PM domain to power up.
 312  */
 313 int pm_genpd_name_poweron(const char *domain_name)
 314 {
 315         struct generic_pm_domain *genpd;
 316
 317         genpd = pm_genpd_lookup_name(domain_name);
 318         return genpd ? pm_genpd_poweron(genpd) : -EINVAL;
 319 }
 320
 321 static int genpd_start_dev_no_timing(struct generic_pm_domain *genpd,
 322                                      struct device *dev)
 323 {
 324         return GENPD_DEV_CALLBACK(genpd, int, start, dev);
 325 }
 326
 327 static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev)
 328 {
 329         return GENPD_DEV_TIMED_CALLBACK(genpd, int, save_state, dev,
 330                                         save_state_latency_ns, "state save");
 331 }
 332
 333 static int genpd_restore_dev(struct generic_pm_domain *genpd, struct device *dev)
 334 {
 335         return GENPD_DEV_TIMED_CALLBACK(genpd, int, restore_state, dev,
 336                                         restore_state_latency_ns,
 337                                         "state restore");
 338 }
 339
 340 static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
 341                                      unsigned long val, void *ptr)
 342 {
 343         struct generic_pm_domain_data *gpd_data;
 344         struct device *dev;
 345
 346         gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
 347         dev = gpd_data->base.dev;
 348
 349         for (;;) {
 350                 struct generic_pm_domain *genpd;
 351                 struct pm_domain_data *pdd;
 352
 353                 spin_lock_irq(&dev->power.lock);
 354
 355                 pdd = dev->power.subsys_data ?
 356                                 dev->power.subsys_data->domain_data : NULL;
 357                 if (pdd && pdd->dev) {
 358                         to_gpd_data(pdd)->td.constraint_changed = true;
 359                         genpd = dev_to_genpd(dev);
 360                 } else {
 361                         genpd = ERR_PTR(-ENODATA);
 362                 }
 363
 364                 spin_unlock_irq(&dev->power.lock);
 365
 366                 if (!IS_ERR(genpd)) {
 367                         mutex_lock(&genpd->lock);
 368                         genpd->max_off_time_changed = true;
 369                         mutex_unlock(&genpd->lock);
 370                 }
 371
 372                 dev = dev->parent;
 373                 if (!dev || dev->power.ignore_children)
 374                         break;
 375         }
 376
 377         return NOTIFY_DONE;
 378 }
 379
 380 /**
 381  * __pm_genpd_save_device - Save the pre-suspend state of a device.
 382  * @pdd: Domain data of the device to save the state of.
 383  * @genpd: PM domain the device belongs to.
 384  */
 385 static int __pm_genpd_save_device(struct pm_domain_data *pdd,
 386                                   struct generic_pm_domain *genpd)
 387         __releases(&genpd->lock) __acquires(&genpd->lock)
 388 {
 389         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 390         struct device *dev = pdd->dev;
 391         int ret = 0;
 392
 393         if (gpd_data->need_restore > 0)
 394                 return 0;
 395
 396         /*
 397          * If the value of the need_restore flag is still unknown at this point,
 398          * we trust that pm_genpd_poweroff() has verified that the device is
 399          * already runtime PM suspended.
 400          */
 401         if (gpd_data->need_restore < 0) {
 402                 gpd_data->need_restore = 1;
 403                 return 0;
 404         }
 405
 406         mutex_unlock(&genpd->lock);
 407
 408         genpd_start_dev(genpd, dev);
 409         ret = genpd_save_dev(genpd, dev);
 410         genpd_stop_dev(genpd, dev);
 411
 412         mutex_lock(&genpd->lock);
 413
 414         if (!ret)
 415                 gpd_data->need_restore = 1;
 416
 417         return ret;
 418 }
 419
 420 /**
 421  * __pm_genpd_restore_device - Restore the pre-suspend state of a device.
 422  * @pdd: Domain data of the device to restore the state of.
 423  * @genpd: PM domain the device belongs to.
 424  */
 425 static void __pm_genpd_restore_device(struct pm_domain_data *pdd,
 426                                       struct generic_pm_domain *genpd)
 427         __releases(&genpd->lock) __acquires(&genpd->lock)
 428 {
 429         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 430         struct device *dev = pdd->dev;
 431         int need_restore = gpd_data->need_restore;
 432
 433         gpd_data->need_restore = 0;
 434         mutex_unlock(&genpd->lock);
 435
 436         genpd_start_dev(genpd, dev);
 437
 438         /*
 439          * Call genpd_restore_dev() for recently added devices too (need_restore
 440          * is negative then).
 441          */
 442         if (need_restore)
 443                 genpd_restore_dev(genpd, dev);
 444
 445         mutex_lock(&genpd->lock);
 446 }
 447
 448 /**
 449  * genpd_abort_poweroff - Check if a PM domain power off should be aborted.
 450  * @genpd: PM domain to check.
 451  *
 452  * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during
 453  * a "power off" operation, which means that a "power on" has occured in the
 454  * meantime, or if its resume_count field is different from zero, which means
 455  * that one of its devices has been resumed in the meantime.
 456  */
 457 static bool genpd_abort_poweroff(struct generic_pm_domain *genpd)
 458 {
 459         return genpd->status == GPD_STATE_WAIT_MASTER
 460                 || genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0;
 461 }
 462
 463 /**
 464  * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff().
 465  * @genpd: PM domait to power off.
 466  *
 467  * Queue up the execution of pm_genpd_poweroff() unless it's already been done
 468  * before.
 469  */
 470 static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
 471 {
 472         queue_work(pm_wq, &genpd->power_off_work);
 473 }
 474
 475 /**
 476  * pm_genpd_poweroff - Remove power from a given PM domain.
 477  * @genpd: PM domain to power down.
 478  *
 479  * If all of the @genpd's devices have been suspended and all of its subdomains
 480  * have been powered down, run the runtime suspend callbacks provided by all of
 481  * the @genpd's devices' drivers and remove power from @genpd.
 482  */
 483 static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
 484         __releases(&genpd->lock) __acquires(&genpd->lock)
 485 {
 486         struct pm_domain_data *pdd;
 487         struct gpd_link *link;
 488         unsigned int not_suspended;
 489         int ret = 0;
 490
 491  start:
 492         /*
 493          * Do not try to power off the domain in the following situations:
 494          * (1) The domain is already in the "power off" state.
 495          * (2) The domain is waiting for its master to power up.
 496          * (3) One of the domain's devices is being resumed right now.
 497          * (4) System suspend is in progress.
 498          */
 499         if (genpd->status == GPD_STATE_POWER_OFF
 500             || genpd->status == GPD_STATE_WAIT_MASTER
 501             || genpd->resume_count > 0 || genpd->prepared_count > 0)
 502                 return 0;
 503
 504         if (atomic_read(&genpd->sd_count) > 0)
 505                 return -EBUSY;
 506
 507         not_suspended = 0;
 508         list_for_each_entry(pdd, &genpd->dev_list, list_node) {
 509                 enum pm_qos_flags_status stat;
 510
 511                 stat = dev_pm_qos_flags(pdd->dev,
 512                                         PM_QOS_FLAG_NO_POWER_OFF
 513                                                 | PM_QOS_FLAG_REMOTE_WAKEUP);
 514                 if (stat > PM_QOS_FLAGS_NONE)
 515                         return -EBUSY;
 516
 517                 if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
 518                     || pdd->dev->power.irq_safe))
 519                         not_suspended++;
 520         }
 521
 522         if (not_suspended > genpd->in_progress)
 523                 return -EBUSY;
 524
 525         if (genpd->poweroff_task) {
 526                 /*
 527                  * Another instance of pm_genpd_poweroff() is executing
 528                  * callbacks, so tell it to start over and return.
 529                  */
 530                 genpd->status = GPD_STATE_REPEAT;
 531                 return 0;
 532         }
 533
 534         if (genpd->gov && genpd->gov->power_down_ok) {
 535                 if (!genpd->gov->power_down_ok(&genpd->domain))
 536                         return -EAGAIN;
 537         }
 538
 539         genpd->status = GPD_STATE_BUSY;
 540         genpd->poweroff_task = current;
 541
 542         list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) {
 543                 ret = atomic_read(&genpd->sd_count) == 0 ?
 544                         __pm_genpd_save_device(pdd, genpd) : -EBUSY;
 545
 546                 if (genpd_abort_poweroff(genpd))
 547                         goto out;
 548
 549                 if (ret) {
 550                         genpd_set_active(genpd);
 551                         goto out;
 552                 }
 553
 554                 if (genpd->status == GPD_STATE_REPEAT) {
 555                         genpd->poweroff_task = NULL;
 556                         goto start;
 557                 }
 558         }
 559
 560         if (genpd->cpuidle_data) {
 561                 /*
 562                  * If cpuidle_data is set, cpuidle should turn the domain off
 563                  * when the CPU in it is idle.  In that case we don't decrement
 564                  * the subdomain counts of the master domains, so that power is
 565                  * not removed from the current domain prematurely as a result
 566                  * of cutting off the masters' power.
 567                  */
 568                 genpd->status = GPD_STATE_POWER_OFF;
 569                 cpuidle_pause_and_lock();
 570                 genpd->cpuidle_data->idle_state->disabled = false;
 571                 cpuidle_resume_and_unlock();
 572                 goto out;
 573         }
 574
 575         if (genpd->power_off) {
 576                 if (atomic_read(&genpd->sd_count) > 0) {
 577                         ret = -EBUSY;
 578                         goto out;
 579                 }
 580
 581                 /*
 582                  * If sd_count > 0 at this point, one of the subdomains hasn't
 583                  * managed to call pm_genpd_poweron() for the master yet after
 584                  * incrementing it.  In that case pm_genpd_poweron() will wait
 585                  * for us to drop the lock, so we can call .power_off() and let
 586                  * the pm_genpd_poweron() restore power for us (this shouldn't
 587                  * happen very often).
 588                  */
 589                 ret = genpd_power_off(genpd);
 590                 if (ret == -EBUSY) {
 591                         genpd_set_active(genpd);
 592                         goto out;
 593                 }
 594         }
 595
 596         genpd->status = GPD_STATE_POWER_OFF;
 597
 598         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 599                 genpd_sd_counter_dec(link->master);
 600                 genpd_queue_power_off_work(link->master);
 601         }
 602
 603  out:
 604         genpd->poweroff_task = NULL;
 605         wake_up_all(&genpd->status_wait_queue);
 606         return ret;
 607 }
 608
 609 /**
 610  * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
 611  * @work: Work structure used for scheduling the execution of this function.
 612  */
 613 static void genpd_power_off_work_fn(struct work_struct *work)
 614 {
 615         struct generic_pm_domain *genpd;
 616
 617         genpd = container_of(work, struct generic_pm_domain, power_off_work);
 618
 619         genpd_acquire_lock(genpd);
 620         pm_genpd_poweroff(genpd);
 621         genpd_release_lock(genpd);
 622 }
 623
 624 /**
 625  * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
 626  * @dev: Device to suspend.
 627  *
 628  * Carry out a runtime suspend of a device under the assumption that its
 629  * pm_domain field points to the domain member of an object of type
 630  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 631  */
 632 static int pm_genpd_runtime_suspend(struct device *dev)
 633 {
 634         struct generic_pm_domain *genpd;
 635         struct generic_pm_domain_data *gpd_data;
 636         bool (*stop_ok)(struct device *__dev);
 637         int ret;
 638
 639         dev_dbg(dev, "%s()\n", __func__);
 640
 641         genpd = dev_to_genpd(dev);
 642         if (IS_ERR(genpd))
 643                 return -EINVAL;
 644
 645         stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
 646         if (stop_ok && !stop_ok(dev))
 647                 return -EBUSY;
 648
 649         ret = genpd_stop_dev(genpd, dev);
 650         if (ret)
 651                 return ret;
 652
 653         /*
 654          * If power.irq_safe is set, this routine will be run with interrupts
 655          * off, so it can't use mutexes.
 656          */
 657         if (dev->power.irq_safe)
 658                 return 0;
 659
 660         mutex_lock(&genpd->lock);
 661
 662         /*
 663          * If we have an unknown state of the need_restore flag, it means none
 664          * of the runtime PM callbacks has been invoked yet. Let's update the
 665          * flag to reflect that the current state is active.
 666          */
 667         gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
 668         if (gpd_data->need_restore < 0)
 669                 gpd_data->need_restore = 0;
 670
 671         genpd->in_progress++;
 672         pm_genpd_poweroff(genpd);
 673         genpd->in_progress--;
 674         mutex_unlock(&genpd->lock);
 675
 676         return 0;
 677 }
 678
 679 /**
 680  * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
 681  * @dev: Device to resume.
 682  *
 683  * Carry out a runtime resume of a device under the assumption that its
 684  * pm_domain field points to the domain member of an object of type
 685  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 686  */
 687 static int pm_genpd_runtime_resume(struct device *dev)
 688 {
 689         struct generic_pm_domain *genpd;
 690         DEFINE_WAIT(wait);
 691         int ret;
 692
 693         dev_dbg(dev, "%s()\n", __func__);
 694
 695         genpd = dev_to_genpd(dev);
 696         if (IS_ERR(genpd))
 697                 return -EINVAL;
 698
 699         /* If power.irq_safe, the PM domain is never powered off. */
 700         if (dev->power.irq_safe)
 701                 return genpd_start_dev_no_timing(genpd, dev);
 702
 703         mutex_lock(&genpd->lock);
 704         ret = __pm_genpd_poweron(genpd);
 705         if (ret) {
 706                 mutex_unlock(&genpd->lock);
 707                 return ret;
 708         }
 709         genpd->status = GPD_STATE_BUSY;
 710         genpd->resume_count++;
 711         for (;;) {
 712                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 713                                 TASK_UNINTERRUPTIBLE);
 714                 /*
 715                  * If current is the powering off task, we have been called
 716                  * reentrantly from one of the device callbacks, so we should
 717                  * not wait.
 718                  */
 719                 if (!genpd->poweroff_task || genpd->poweroff_task == current)
 720                         break;
 721                 mutex_unlock(&genpd->lock);
 722
 723                 schedule();
 724
 725                 mutex_lock(&genpd->lock);
 726         }
 727         finish_wait(&genpd->status_wait_queue, &wait);
 728         __pm_genpd_restore_device(dev->power.subsys_data->domain_data, genpd);
 729         genpd->resume_count--;
 730         genpd_set_active(genpd);
 731         wake_up_all(&genpd->status_wait_queue);
 732         mutex_unlock(&genpd->lock);
 733
 734         return 0;
 735 }
 736
 737 static bool pd_ignore_unused;
 738 static int __init pd_ignore_unused_setup(char *__unused)
 739 {
 740         pd_ignore_unused = true;
 741         return 1;
 742 }
 743 __setup("pd_ignore_unused", pd_ignore_unused_setup);
 744
 745 /**
 746  * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use.
 747  */
 748 void pm_genpd_poweroff_unused(void)
 749 {
 750         struct generic_pm_domain *genpd;
 751
 752         if (pd_ignore_unused) {
 753                 pr_warn("genpd: Not disabling unused power domains\n");
 754                 return;
 755         }
 756
 757         mutex_lock(&gpd_list_lock);
 758
 759         list_for_each_entry(genpd, &gpd_list, gpd_list_node)
 760                 genpd_queue_power_off_work(genpd);
 761
 762         mutex_unlock(&gpd_list_lock);
 763 }
 764
 765 static int __init genpd_poweroff_unused(void)
 766 {
 767         pm_genpd_poweroff_unused();
 768         return 0;
 769 }
 770 late_initcall(genpd_poweroff_unused);
 771
 772 #ifdef CONFIG_PM_SLEEP
 773
 774 /**
 775  * pm_genpd_present - Check if the given PM domain has been initialized.
 776  * @genpd: PM domain to check.
 777  */
 778 static bool pm_genpd_present(const struct generic_pm_domain *genpd)
 779 {
 780         const struct generic_pm_domain *gpd;
 781
 782         if (IS_ERR_OR_NULL(genpd))
 783                 return false;
 784
 785         list_for_each_entry(gpd, &gpd_list, gpd_list_node)
 786                 if (gpd == genpd)
 787                         return true;
 788
 789         return false;
 790 }
 791
 792 static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
 793                                     struct device *dev)
 794 {
 795         return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev);
 796 }
 797
 798 /**
 799  * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
 800  * @genpd: PM domain to power off, if possible.
 801  *
 802  * Check if the given PM domain can be powered off (during system suspend or
 803  * hibernation) and do that if so.  Also, in that case propagate to its masters.
 804  *
 805  * This function is only called in "noirq" and "syscore" stages of system power
 806  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 807  * executed sequentially, so it is guaranteed that it will never run twice in
 808  * parallel).
 809  */
 810 static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
 811 {
 812         struct gpd_link *link;
 813
 814         if (genpd->status == GPD_STATE_POWER_OFF)
 815                 return;
 816
 817         if (genpd->suspended_count != genpd->device_count
 818             || atomic_read(&genpd->sd_count) > 0)
 819                 return;
 820
 821         genpd_power_off(genpd);
 822
 823         genpd->status = GPD_STATE_POWER_OFF;
 824
 825         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 826                 genpd_sd_counter_dec(link->master);
 827                 pm_genpd_sync_poweroff(link->master);
 828         }
 829 }
 830
 831 /**
 832  * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters.
 833  * @genpd: PM domain to power on.
 834  *
 835  * This function is only called in "noirq" and "syscore" stages of system power
 836  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 837  * executed sequentially, so it is guaranteed that it will never run twice in
 838  * parallel).
 839  */
 840 static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)
 841 {
 842         struct gpd_link *link;
 843
 844         if (genpd->status != GPD_STATE_POWER_OFF)
 845                 return;
 846
 847         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 848                 pm_genpd_sync_poweron(link->master);
 849                 genpd_sd_counter_inc(link->master);
 850         }
 851
 852         genpd_power_on(genpd);
 853
 854         genpd->status = GPD_STATE_ACTIVE;
 855 }
 856
 857 /**
 858  * resume_needed - Check whether to resume a device before system suspend.
 859  * @dev: Device to check.
 860  * @genpd: PM domain the device belongs to.
 861  *
 862  * There are two cases in which a device that can wake up the system from sleep
 863  * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled
 864  * to wake up the system and it has to remain active for this purpose while the
 865  * system is in the sleep state and (2) if the device is not enabled to wake up
 866  * the system from sleep states and it generally doesn't generate wakeup signals
 867  * by itself (those signals are generated on its behalf by other parts of the
 868  * system).  In the latter case it may be necessary to reconfigure the device's
 869  * wakeup settings during system suspend, because it may have been set up to
 870  * signal remote wakeup from the system's working state as needed by runtime PM.
 871  * Return 'true' in either of the above cases.
 872  */
 873 static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd)
 874 {
 875         bool active_wakeup;
 876
 877         if (!device_can_wakeup(dev))
 878                 return false;
 879
 880         active_wakeup = genpd_dev_active_wakeup(genpd, dev);
 881         return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
 882 }
 883
 884 /**
 885  * pm_genpd_prepare - Start power transition of a device in a PM domain.
 886  * @dev: Device to start the transition of.
 887  *
 888  * Start a power transition of a device (during a system-wide power transition)
 889  * under the assumption that its pm_domain field points to the domain member of
 890  * an object of type struct generic_pm_domain representing a PM domain
 891  * consisting of I/O devices.
 892  */
 893 static int pm_genpd_prepare(struct device *dev)
 894 {
 895         struct generic_pm_domain *genpd;
 896         int ret;
 897
 898         dev_dbg(dev, "%s()\n", __func__);
 899
 900         genpd = dev_to_genpd(dev);
 901         if (IS_ERR(genpd))
 902                 return -EINVAL;
 903
 904         /*
 905          * If a wakeup request is pending for the device, it should be woken up
 906          * at this point and a system wakeup event should be reported if it's
 907          * set up to wake up the system from sleep states.
 908          */
 909         pm_runtime_get_noresume(dev);
 910         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
 911                 pm_wakeup_event(dev, 0);
 912
 913         if (pm_wakeup_pending()) {
 914                 pm_runtime_put(dev);
 915                 return -EBUSY;
 916         }
 917
 918         if (resume_needed(dev, genpd))
 919                 pm_runtime_resume(dev);
 920
 921         genpd_acquire_lock(genpd);
 922
 923         if (genpd->prepared_count++ == 0) {
 924                 genpd->suspended_count = 0;
 925                 genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF;
 926         }
 927
 928         genpd_release_lock(genpd);
 929
 930         if (genpd->suspend_power_off) {
 931                 pm_runtime_put_noidle(dev);
 932                 return 0;
 933         }
 934
 935         /*
 936          * The PM domain must be in the GPD_STATE_ACTIVE state at this point,
 937          * so pm_genpd_poweron() will return immediately, but if the device
 938          * is suspended (e.g. it's been stopped by genpd_stop_dev()), we need
 939          * to make it operational.
 940          */
 941         pm_runtime_resume(dev);
 942         __pm_runtime_disable(dev, false);
 943
 944         ret = pm_generic_prepare(dev);
 945         if (ret) {
 946                 mutex_lock(&genpd->lock);
 947
 948                 if (--genpd->prepared_count == 0)
 949                         genpd->suspend_power_off = false;
 950
 951                 mutex_unlock(&genpd->lock);
 952                 pm_runtime_enable(dev);
 953         }
 954
 955         pm_runtime_put(dev);
 956         return ret;
 957 }
 958
 959 /**
 960  * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain.
 961  * @dev: Device to suspend.
 962  *
 963  * Suspend a device under the assumption that its pm_domain field points to the
 964  * domain member of an object of type struct generic_pm_domain representing
 965  * a PM domain consisting of I/O devices.
 966  */
 967 static int pm_genpd_suspend(struct device *dev)
 968 {
 969         struct generic_pm_domain *genpd;
 970
 971         dev_dbg(dev, "%s()\n", __func__);
 972
 973         genpd = dev_to_genpd(dev);
 974         if (IS_ERR(genpd))
 975                 return -EINVAL;
 976
 977         return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev);
 978 }
 979
 980 /**
 981  * pm_genpd_suspend_late - Late suspend of a device from an I/O PM domain.
 982  * @dev: Device to suspend.
 983  *
 984  * Carry out a late suspend of a device under the assumption that its
 985  * pm_domain field points to the domain member of an object of type
 986  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 987  */
 988 static int pm_genpd_suspend_late(struct device *dev)
 989 {
 990         struct generic_pm_domain *genpd;
 991
 992         dev_dbg(dev, "%s()\n", __func__);
 993
 994         genpd = dev_to_genpd(dev);
 995         if (IS_ERR(genpd))
 996                 return -EINVAL;
 997
 998         return genpd->suspend_power_off ? 0 : pm_generic_suspend_late(dev);
 999 }
1000
1001 /**
1002  * pm_genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
1003  * @dev: Device to suspend.
1004  *
1005  * Stop the device and remove power from the domain if all devices in it have
1006  * been stopped.
1007  */
1008 static int pm_genpd_suspend_noirq(struct device *dev)
1009 {
1010         struct generic_pm_domain *genpd;
1011
1012         dev_dbg(dev, "%s()\n", __func__);
1013
1014         genpd = dev_to_genpd(dev);
1015         if (IS_ERR(genpd))
1016                 return -EINVAL;
1017
1018         if (genpd->suspend_power_off
1019             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1020                 return 0;
1021
1022         genpd_stop_dev(genpd, dev);
1023
1024         /*
1025          * Since all of the "noirq" callbacks are executed sequentially, it is
1026          * guaranteed that this function will never run twice in parallel for
1027          * the same PM domain, so it is not necessary to use locking here.
1028          */
1029         genpd->suspended_count++;
1030         pm_genpd_sync_poweroff(genpd);
1031
1032         return 0;
1033 }
1034
1035 /**
1036  * pm_genpd_resume_noirq - Start of resume of device in an I/O PM domain.
1037  * @dev: Device to resume.
1038  *
1039  * Restore power to the device's PM domain, if necessary, and start the device.
1040  */
1041 static int pm_genpd_resume_noirq(struct device *dev)
1042 {
1043         struct generic_pm_domain *genpd;
1044
1045         dev_dbg(dev, "%s()\n", __func__);
1046
1047         genpd = dev_to_genpd(dev);
1048         if (IS_ERR(genpd))
1049                 return -EINVAL;
1050
1051         if (genpd->suspend_power_off
1052             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1053                 return 0;
1054
1055         /*
1056          * Since all of the "noirq" callbacks are executed sequentially, it is
1057          * guaranteed that this function will never run twice in parallel for
1058          * the same PM domain, so it is not necessary to use locking here.
1059          */
1060         pm_genpd_sync_poweron(genpd);
1061         genpd->suspended_count--;
1062
1063         return genpd_start_dev(genpd, dev);
1064 }
1065
1066 /**
1067  * pm_genpd_resume_early - Early resume of a device in an I/O PM domain.
1068  * @dev: Device to resume.
1069  *
1070  * Carry out an early resume of a device under the assumption that its
1071  * pm_domain field points to the domain member of an object of type
1072  * struct generic_pm_domain representing a power domain consisting of I/O
1073  * devices.
1074  */
1075 static int pm_genpd_resume_early(struct device *dev)
1076 {
1077         struct generic_pm_domain *genpd;
1078
1079         dev_dbg(dev, "%s()\n", __func__);
1080
1081         genpd = dev_to_genpd(dev);
1082         if (IS_ERR(genpd))
1083                 return -EINVAL;
1084
1085         return genpd->suspend_power_off ? 0 : pm_generic_resume_early(dev);
1086 }
1087
1088 /**
1089  * pm_genpd_resume - Resume of device in an I/O PM domain.
1090  * @dev: Device to resume.
1091  *
1092  * Resume a device under the assumption that its pm_domain field points to the
1093  * domain member of an object of type struct generic_pm_domain representing
1094  * a power domain consisting of I/O devices.
1095  */
1096 static int pm_genpd_resume(struct device *dev)
1097 {
1098         struct generic_pm_domain *genpd;
1099
1100         dev_dbg(dev, "%s()\n", __func__);
1101
1102         genpd = dev_to_genpd(dev);
1103         if (IS_ERR(genpd))
1104                 return -EINVAL;
1105
1106         return genpd->suspend_power_off ? 0 : pm_generic_resume(dev);
1107 }
1108
1109 /**
1110  * pm_genpd_freeze - Freezing a device in an I/O PM domain.
1111  * @dev: Device to freeze.
1112  *
1113  * Freeze a device under the assumption that its pm_domain field points to the
1114  * domain member of an object of type struct generic_pm_domain representing
1115  * a power domain consisting of I/O devices.
1116  */
1117 static int pm_genpd_freeze(struct device *dev)
1118 {
1119         struct generic_pm_domain *genpd;
1120
1121         dev_dbg(dev, "%s()\n", __func__);
1122
1123         genpd = dev_to_genpd(dev);
1124         if (IS_ERR(genpd))
1125                 return -EINVAL;
1126
1127         return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev);
1128 }
1129
1130 /**
1131  * pm_genpd_freeze_late - Late freeze of a device in an I/O PM domain.
1132  * @dev: Device to freeze.
1133  *
1134  * Carry out a late freeze of a device under the assumption that its
1135  * pm_domain field points to the domain member of an object of type
1136  * struct generic_pm_domain representing a power domain consisting of I/O
1137  * devices.
1138  */
1139 static int pm_genpd_freeze_late(struct device *dev)
1140 {
1141         struct generic_pm_domain *genpd;
1142
1143         dev_dbg(dev, "%s()\n", __func__);
1144
1145         genpd = dev_to_genpd(dev);
1146         if (IS_ERR(genpd))
1147                 return -EINVAL;
1148
1149         return genpd->suspend_power_off ? 0 : pm_generic_freeze_late(dev);
1150 }
1151
1152 /**
1153  * pm_genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
1154  * @dev: Device to freeze.
1155  *
1156  * Carry out a late freeze of a device under the assumption that its
1157  * pm_domain field points to the domain member of an object of type
1158  * struct generic_pm_domain representing a power domain consisting of I/O
1159  * devices.
1160  */
1161 static int pm_genpd_freeze_noirq(struct device *dev)
1162 {
1163         struct generic_pm_domain *genpd;
1164
1165         dev_dbg(dev, "%s()\n", __func__);
1166
1167         genpd = dev_to_genpd(dev);
1168         if (IS_ERR(genpd))
1169                 return -EINVAL;
1170
1171         return genpd->suspend_power_off ? 0 : genpd_stop_dev(genpd, dev);
1172 }
1173
1174 /**
1175  * pm_genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
1176  * @dev: Device to thaw.
1177  *
1178  * Start the device, unless power has been removed from the domain already
1179  * before the system transition.
1180  */
1181 static int pm_genpd_thaw_noirq(struct device *dev)
1182 {
1183         struct generic_pm_domain *genpd;
1184
1185         dev_dbg(dev, "%s()\n", __func__);
1186
1187         genpd = dev_to_genpd(dev);
1188         if (IS_ERR(genpd))
1189                 return -EINVAL;
1190
1191         return genpd->suspend_power_off ? 0 : genpd_start_dev(genpd, dev);
1192 }
1193
1194 /**
1195  * pm_genpd_thaw_early - Early thaw of device in an I/O PM domain.
1196  * @dev: Device to thaw.
1197  *
1198  * Carry out an early thaw of a device under the assumption that its
1199  * pm_domain field points to the domain member of an object of type
1200  * struct generic_pm_domain representing a power domain consisting of I/O
1201  * devices.
1202  */
1203 static int pm_genpd_thaw_early(struct device *dev)
1204 {
1205         struct generic_pm_domain *genpd;
1206
1207         dev_dbg(dev, "%s()\n", __func__);
1208
1209         genpd = dev_to_genpd(dev);
1210         if (IS_ERR(genpd))
1211                 return -EINVAL;
1212
1213         return genpd->suspend_power_off ? 0 : pm_generic_thaw_early(dev);
1214 }
1215
1216 /**
1217  * pm_genpd_thaw - Thaw a device belonging to an I/O power domain.
1218  * @dev: Device to thaw.
1219  *
1220  * Thaw a device under the assumption that its pm_domain field points to the
1221  * domain member of an object of type struct generic_pm_domain representing
1222  * a power domain consisting of I/O devices.
1223  */
1224 static int pm_genpd_thaw(struct device *dev)
1225 {
1226         struct generic_pm_domain *genpd;
1227
1228         dev_dbg(dev, "%s()\n", __func__);
1229
1230         genpd = dev_to_genpd(dev);
1231         if (IS_ERR(genpd))
1232                 return -EINVAL;
1233
1234         return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev);
1235 }
1236
1237 /**
1238  * pm_genpd_restore_noirq - Start of restore of device in an I/O PM domain.
1239  * @dev: Device to resume.
1240  *
1241  * Make sure the domain will be in the same power state as before the
1242  * hibernation the system is resuming from and start the device if necessary.
1243  */
1244 static int pm_genpd_restore_noirq(struct device *dev)
1245 {
1246         struct generic_pm_domain *genpd;
1247
1248         dev_dbg(dev, "%s()\n", __func__);
1249
1250         genpd = dev_to_genpd(dev);
1251         if (IS_ERR(genpd))
1252                 return -EINVAL;
1253
1254         /*
1255          * Since all of the "noirq" callbacks are executed sequentially, it is
1256          * guaranteed that this function will never run twice in parallel for
1257          * the same PM domain, so it is not necessary to use locking here.
1258          *
1259          * At this point suspended_count == 0 means we are being run for the
1260          * first time for the given domain in the present cycle.
1261          */
1262         if (genpd->suspended_count++ == 0) {
1263                 /*
1264                  * The boot kernel might put the domain into arbitrary state,
1265                  * so make it appear as powered off to pm_genpd_sync_poweron(),
1266                  * so that it tries to power it on in case it was really off.
1267                  */
1268                 genpd->status = GPD_STATE_POWER_OFF;
1269                 if (genpd->suspend_power_off) {
1270                         /*
1271                          * If the domain was off before the hibernation, make
1272                          * sure it will be off going forward.
1273                          */
1274                         genpd_power_off(genpd);
1275
1276                         return 0;
1277                 }
1278         }
1279
1280         if (genpd->suspend_power_off)
1281                 return 0;
1282
1283         pm_genpd_sync_poweron(genpd);
1284
1285         return genpd_start_dev(genpd, dev);
1286 }
1287
1288 /**
1289  * pm_genpd_complete - Complete power transition of a device in a power domain.
1290  * @dev: Device to complete the transition of.
1291  *
1292  * Complete a power transition of a device (during a system-wide power
1293  * transition) under the assumption that its pm_domain field points to the
1294  * domain member of an object of type struct generic_pm_domain representing
1295  * a power domain consisting of I/O devices.
1296  */
1297 static void pm_genpd_complete(struct device *dev)
1298 {
1299         struct generic_pm_domain *genpd;
1300         bool run_complete;
1301
1302         dev_dbg(dev, "%s()\n", __func__);
1303
1304         genpd = dev_to_genpd(dev);
1305         if (IS_ERR(genpd))
1306                 return;
1307
1308         mutex_lock(&genpd->lock);
1309
1310         run_complete = !genpd->suspend_power_off;
1311         if (--genpd->prepared_count == 0)
1312                 genpd->suspend_power_off = false;
1313
1314         mutex_unlock(&genpd->lock);
1315
1316         if (run_complete) {
1317                 pm_generic_complete(dev);
1318                 pm_runtime_set_active(dev);
1319                 pm_runtime_enable(dev);
1320                 pm_request_idle(dev);
1321         }
1322 }
1323
1324 /**
1325  * genpd_syscore_switch - Switch power during system core suspend or resume.
1326  * @dev: Device that normally is marked as "always on" to switch power for.
1327  *
1328  * This routine may only be called during the system core (syscore) suspend or
1329  * resume phase for devices whose "always on" flags are set.
1330  */
1331 static void genpd_syscore_switch(struct device *dev, bool suspend)
1332 {
1333         struct generic_pm_domain *genpd;
1334
1335         genpd = dev_to_genpd(dev);
1336         if (!pm_genpd_present(genpd))
1337                 return;
1338
1339         if (suspend) {
1340                 genpd->suspended_count++;
1341                 pm_genpd_sync_poweroff(genpd);
1342         } else {
1343                 pm_genpd_sync_poweron(genpd);
1344                 genpd->suspended_count--;
1345         }
1346 }
1347
1348 void pm_genpd_syscore_poweroff(struct device *dev)
1349 {
1350         genpd_syscore_switch(dev, true);
1351 }
1352 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweroff);
1353
1354 void pm_genpd_syscore_poweron(struct device *dev)
1355 {
1356         genpd_syscore_switch(dev, false);
1357 }
1358 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron);
1359
1360 #else /* !CONFIG_PM_SLEEP */
1361
1362 #define pm_genpd_prepare                NULL
1363 #define pm_genpd_suspend                NULL
1364 #define pm_genpd_suspend_late           NULL
1365 #define pm_genpd_suspend_noirq          NULL
1366 #define pm_genpd_resume_early           NULL
1367 #define pm_genpd_resume_noirq           NULL
1368 #define pm_genpd_resume                 NULL
1369 #define pm_genpd_freeze                 NULL
1370 #define pm_genpd_freeze_late            NULL
1371 #define pm_genpd_freeze_noirq           NULL
1372 #define pm_genpd_thaw_early             NULL
1373 #define pm_genpd_thaw_noirq             NULL
1374 #define pm_genpd_thaw                   NULL
1375 #define pm_genpd_restore_noirq          NULL
1376 #define pm_genpd_complete               NULL
1377
1378 #endif /* CONFIG_PM_SLEEP */
1379
1380 static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
1381                                         struct generic_pm_domain *genpd,
1382                                         struct gpd_timing_data *td)
1383 {
1384         struct generic_pm_domain_data *gpd_data;
1385         int ret;
1386
1387         ret = dev_pm_get_subsys_data(dev);
1388         if (ret)
1389                 return ERR_PTR(ret);
1390
1391         gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
1392         if (!gpd_data) {
1393                 ret = -ENOMEM;
1394                 goto err_put;
1395         }
1396
1397         if (td)
1398                 gpd_data->td = *td;
1399
1400         gpd_data->base.dev = dev;
1401         gpd_data->need_restore = -1;
1402         gpd_data->td.constraint_changed = true;
1403         gpd_data->td.effective_constraint_ns = -1;
1404         gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
1405
1406         spin_lock_irq(&dev->power.lock);
1407
1408         if (dev->power.subsys_data->domain_data) {
1409                 ret = -EINVAL;
1410                 goto err_free;
1411         }
1412
1413         dev->power.subsys_data->domain_data = &gpd_data->base;
1414         dev->pm_domain = &genpd->domain;
1415
1416         spin_unlock_irq(&dev->power.lock);
1417
1418         return gpd_data;
1419
1420  err_free:
1421         spin_unlock_irq(&dev->power.lock);
1422         kfree(gpd_data);
1423  err_put:
1424         dev_pm_put_subsys_data(dev);
1425         return ERR_PTR(ret);
1426 }
1427
1428 static void genpd_free_dev_data(struct device *dev,
1429                                 struct generic_pm_domain_data *gpd_data)
1430 {
1431         spin_lock_irq(&dev->power.lock);
1432
1433         dev->pm_domain = NULL;
1434         dev->power.subsys_data->domain_data = NULL;
1435
1436         spin_unlock_irq(&dev->power.lock);
1437
1438         kfree(gpd_data);
1439         dev_pm_put_subsys_data(dev);
1440 }
1441
1442 /**
1443  * __pm_genpd_add_device - Add a device to an I/O PM domain.
1444  * @genpd: PM domain to add the device to.
1445  * @dev: Device to be added.
1446  * @td: Set of PM QoS timing parameters to attach to the device.
1447  */
1448 int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
1449                           struct gpd_timing_data *td)
1450 {
1451         struct generic_pm_domain_data *gpd_data;
1452         int ret = 0;
1453
1454         dev_dbg(dev, "%s()\n", __func__);
1455
1456         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
1457                 return -EINVAL;
1458
1459         gpd_data = genpd_alloc_dev_data(dev, genpd, td);
1460         if (IS_ERR(gpd_data))
1461                 return PTR_ERR(gpd_data);
1462
1463         genpd_acquire_lock(genpd);
1464
1465         if (genpd->prepared_count > 0) {
1466                 ret = -EAGAIN;
1467                 goto out;
1468         }
1469
1470         if (genpd->attach_dev)
1471                 genpd->attach_dev(genpd, dev);
1472
1473         genpd->device_count++;
1474         genpd->max_off_time_changed = true;
1475
1476         list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
1477
1478  out:
1479         genpd_release_lock(genpd);
1480
1481         if (ret)
1482                 genpd_free_dev_data(dev, gpd_data);
1483         else
1484                 dev_pm_qos_add_notifier(dev, &gpd_data->nb);
1485
1486         return ret;
1487 }
1488
1489 /**
1490  * __pm_genpd_name_add_device - Find I/O PM domain and add a device to it.
1491  * @domain_name: Name of the PM domain to add the device to.
1492  * @dev: Device to be added.
1493  * @td: Set of PM QoS timing parameters to attach to the device.
1494  */
1495 int __pm_genpd_name_add_device(const char *domain_name, struct device *dev,
1496                                struct gpd_timing_data *td)
1497 {
1498         return __pm_genpd_add_device(pm_genpd_lookup_name(domain_name), dev, td);
1499 }
1500
1501 /**
1502  * pm_genpd_remove_device - Remove a device from an I/O PM domain.
1503  * @genpd: PM domain to remove the device from.
1504  * @dev: Device to be removed.
1505  */
1506 int pm_genpd_remove_device(struct generic_pm_domain *genpd,
1507                            struct device *dev)
1508 {
1509         struct generic_pm_domain_data *gpd_data;
1510         struct pm_domain_data *pdd;
1511         int ret = 0;
1512
1513         dev_dbg(dev, "%s()\n", __func__);
1514
1515         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)
1516             ||  IS_ERR_OR_NULL(dev->pm_domain)
1517             ||  pd_to_genpd(dev->pm_domain) != genpd)
1518                 return -EINVAL;
1519
1520         /* The above validation also means we have existing domain_data. */
1521         pdd = dev->power.subsys_data->domain_data;
1522         gpd_data = to_gpd_data(pdd);
1523         dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
1524
1525         genpd_acquire_lock(genpd);
1526
1527         if (genpd->prepared_count > 0) {
1528                 ret = -EAGAIN;
1529                 goto out;
1530         }
1531
1532         genpd->device_count--;
1533         genpd->max_off_time_changed = true;
1534
1535         if (genpd->detach_dev)
1536                 genpd->detach_dev(genpd, dev);
1537
1538         list_del_init(&pdd->list_node);
1539
1540         genpd_release_lock(genpd);
1541
1542         genpd_free_dev_data(dev, gpd_data);
1543
1544         return 0;
1545
1546  out:
1547         genpd_release_lock(genpd);
1548         dev_pm_qos_add_notifier(dev, &gpd_data->nb);
1549
1550         return ret;
1551 }
1552
1553 /**
1554  * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
1555  * @genpd: Master PM domain to add the subdomain to.
1556  * @subdomain: Subdomain to be added.
1557  */
1558 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
1559                            struct generic_pm_domain *subdomain)
1560 {
1561         struct gpd_link *link;
1562         int ret = 0;
1563
1564         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
1565             || genpd == subdomain)
1566                 return -EINVAL;
1567
1568  start:
1569         genpd_acquire_lock(genpd);
1570         mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1571
1572         if (subdomain->status != GPD_STATE_POWER_OFF
1573             && subdomain->status != GPD_STATE_ACTIVE) {
1574                 mutex_unlock(&subdomain->lock);
1575                 genpd_release_lock(genpd);
1576                 goto start;
1577         }
1578
1579         if (genpd->status == GPD_STATE_POWER_OFF
1580             &&  subdomain->status != GPD_STATE_POWER_OFF) {
1581                 ret = -EINVAL;
1582                 goto out;
1583         }
1584
1585         list_for_each_entry(link, &genpd->master_links, master_node) {
1586                 if (link->slave == subdomain && link->master == genpd) {
1587                         ret = -EINVAL;
1588                         goto out;
1589                 }
1590         }
1591
1592         link = kzalloc(sizeof(*link), GFP_KERNEL);
1593         if (!link) {
1594                 ret = -ENOMEM;
1595                 goto out;
1596         }
1597         link->master = genpd;
1598         list_add_tail(&link->master_node, &genpd->master_links);
1599         link->slave = subdomain;
1600         list_add_tail(&link->slave_node, &subdomain->slave_links);
1601         if (subdomain->status != GPD_STATE_POWER_OFF)
1602                 genpd_sd_counter_inc(genpd);
1603
1604  out:
1605         mutex_unlock(&subdomain->lock);
1606         genpd_release_lock(genpd);
1607
1608         return ret;
1609 }
1610
1611 /**
1612  * pm_genpd_add_subdomain_names - Add a subdomain to an I/O PM domain.
1613  * @master_name: Name of the master PM domain to add the subdomain to.
1614  * @subdomain_name: Name of the subdomain to be added.
1615  */
1616 int pm_genpd_add_subdomain_names(const char *master_name,
1617                                  const char *subdomain_name)
1618 {
1619         struct generic_pm_domain *master = NULL, *subdomain = NULL, *gpd;
1620
1621         if (IS_ERR_OR_NULL(master_name) || IS_ERR_OR_NULL(subdomain_name))
1622                 return -EINVAL;
1623
1624         mutex_lock(&gpd_list_lock);
1625         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
1626                 if (!master && !strcmp(gpd->name, master_name))
1627                         master = gpd;
1628
1629                 if (!subdomain && !strcmp(gpd->name, subdomain_name))
1630                         subdomain = gpd;
1631
1632                 if (master && subdomain)
1633                         break;
1634         }
1635         mutex_unlock(&gpd_list_lock);
1636
1637         return pm_genpd_add_subdomain(master, subdomain);
1638 }
1639
1640 /**
1641  * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
1642  * @genpd: Master PM domain to remove the subdomain from.
1643  * @subdomain: Subdomain to be removed.
1644  */
1645 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
1646                               struct generic_pm_domain *subdomain)
1647 {
1648         struct gpd_link *link;
1649         int ret = -EINVAL;
1650
1651         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
1652                 return -EINVAL;
1653
1654  start:
1655         genpd_acquire_lock(genpd);
1656
1657         list_for_each_entry(link, &genpd->master_links, master_node) {
1658                 if (link->slave != subdomain)
1659                         continue;
1660
1661                 mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1662
1663                 if (subdomain->status != GPD_STATE_POWER_OFF
1664                     && subdomain->status != GPD_STATE_ACTIVE) {
1665                         mutex_unlock(&subdomain->lock);
1666                         genpd_release_lock(genpd);
1667                         goto start;
1668                 }
1669
1670                 list_del(&link->master_node);
1671                 list_del(&link->slave_node);
1672                 kfree(link);
1673                 if (subdomain->status != GPD_STATE_POWER_OFF)
1674                         genpd_sd_counter_dec(genpd);
1675
1676                 mutex_unlock(&subdomain->lock);
1677
1678                 ret = 0;
1679                 break;
1680         }
1681
1682         genpd_release_lock(genpd);
1683
1684         return ret;
1685 }
1686
1687 /**
1688  * pm_genpd_attach_cpuidle - Connect the given PM domain with cpuidle.
1689  * @genpd: PM domain to be connected with cpuidle.
1690  * @state: cpuidle state this domain can disable/enable.
1691  *
1692  * Make a PM domain behave as though it contained a CPU core, that is, instead
1693  * of calling its power down routine it will enable the given cpuidle state so
1694  * that the cpuidle subsystem can power it down (if possible and desirable).
1695  */
1696 int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
1697 {
1698         struct cpuidle_driver *cpuidle_drv;
1699         struct gpd_cpuidle_data *cpuidle_data;
1700         struct cpuidle_state *idle_state;
1701         int ret = 0;
1702
1703         if (IS_ERR_OR_NULL(genpd) || state < 0)
1704                 return -EINVAL;
1705
1706         genpd_acquire_lock(genpd);
1707
1708         if (genpd->cpuidle_data) {
1709                 ret = -EEXIST;
1710                 goto out;
1711         }
1712         cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
1713         if (!cpuidle_data) {
1714                 ret = -ENOMEM;
1715                 goto out;
1716         }
1717         cpuidle_drv = cpuidle_driver_ref();
1718         if (!cpuidle_drv) {
1719                 ret = -ENODEV;
1720                 goto err_drv;
1721         }
1722         if (cpuidle_drv->state_count <= state) {
1723                 ret = -EINVAL;
1724                 goto err;
1725         }
1726         idle_state = &cpuidle_drv->states[state];
1727         if (!idle_state->disabled) {
1728                 ret = -EAGAIN;
1729                 goto err;
1730         }
1731         cpuidle_data->idle_state = idle_state;
1732         cpuidle_data->saved_exit_latency = idle_state->exit_latency;
1733         genpd->cpuidle_data = cpuidle_data;
1734         genpd_recalc_cpu_exit_latency(genpd);
1735
1736  out:
1737         genpd_release_lock(genpd);
1738         return ret;
1739
1740  err:
1741         cpuidle_driver_unref();
1742
1743  err_drv:
1744         kfree(cpuidle_data);
1745         goto out;
1746 }
1747
1748 /**
1749  * pm_genpd_name_attach_cpuidle - Find PM domain and connect cpuidle to it.
1750  * @name: Name of the domain to connect to cpuidle.
1751  * @state: cpuidle state this domain can manipulate.
1752  */
1753 int pm_genpd_name_attach_cpuidle(const char *name, int state)
1754 {
1755         return pm_genpd_attach_cpuidle(pm_genpd_lookup_name(name), state);
1756 }
1757
1758 /**
1759  * pm_genpd_detach_cpuidle - Remove the cpuidle connection from a PM domain.
1760  * @genpd: PM domain to remove the cpuidle connection from.
1761  *
1762  * Remove the cpuidle connection set up by pm_genpd_attach_cpuidle() from the
1763  * given PM domain.
1764  */
1765 int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd)
1766 {
1767         struct gpd_cpuidle_data *cpuidle_data;
1768         struct cpuidle_state *idle_state;
1769         int ret = 0;
1770
1771         if (IS_ERR_OR_NULL(genpd))
1772                 return -EINVAL;
1773
1774         genpd_acquire_lock(genpd);
1775
1776         cpuidle_data = genpd->cpuidle_data;
1777         if (!cpuidle_data) {
1778                 ret = -ENODEV;
1779                 goto out;
1780         }
1781         idle_state = cpuidle_data->idle_state;
1782         if (!idle_state->disabled) {
1783                 ret = -EAGAIN;
1784                 goto out;
1785         }
1786         idle_state->exit_latency = cpuidle_data->saved_exit_latency;
1787         cpuidle_driver_unref();
1788         genpd->cpuidle_data = NULL;
1789         kfree(cpuidle_data);
1790
1791  out:
1792         genpd_release_lock(genpd);
1793         return ret;
1794 }
1795
1796 /**
1797  * pm_genpd_name_detach_cpuidle - Find PM domain and disconnect cpuidle from it.
1798  * @name: Name of the domain to disconnect cpuidle from.
1799  */
1800 int pm_genpd_name_detach_cpuidle(const char *name)
1801 {
1802         return pm_genpd_detach_cpuidle(pm_genpd_lookup_name(name));
1803 }
1804
1805 /* Default device callbacks for generic PM domains. */
1806
1807 /**
1808  * pm_genpd_default_save_state - Default "save device state" for PM domains.
1809  * @dev: Device to handle.
1810  */
1811 static int pm_genpd_default_save_state(struct device *dev)
1812 {
1813         int (*cb)(struct device *__dev);
1814
1815         if (dev->type && dev->type->pm)
1816                 cb = dev->type->pm->runtime_suspend;
1817         else if (dev->class && dev->class->pm)
1818                 cb = dev->class->pm->runtime_suspend;
1819         else if (dev->bus && dev->bus->pm)
1820                 cb = dev->bus->pm->runtime_suspend;
1821         else
1822                 cb = NULL;
1823
1824         if (!cb && dev->driver && dev->driver->pm)
1825                 cb = dev->driver->pm->runtime_suspend;
1826
1827         return cb ? cb(dev) : 0;
1828 }
1829
1830 /**
1831  * pm_genpd_default_restore_state - Default PM domains "restore device state".
1832  * @dev: Device to handle.
1833  */
1834 static int pm_genpd_default_restore_state(struct device *dev)
1835 {
1836         int (*cb)(struct device *__dev);
1837
1838         if (dev->type && dev->type->pm)
1839                 cb = dev->type->pm->runtime_resume;
1840         else if (dev->class && dev->class->pm)
1841                 cb = dev->class->pm->runtime_resume;
1842         else if (dev->bus && dev->bus->pm)
1843                 cb = dev->bus->pm->runtime_resume;
1844         else
1845                 cb = NULL;
1846
1847         if (!cb && dev->driver && dev->driver->pm)
1848                 cb = dev->driver->pm->runtime_resume;
1849
1850         return cb ? cb(dev) : 0;
1851 }
1852
1853 /**
1854  * pm_genpd_init - Initialize a generic I/O PM domain object.
1855  * @genpd: PM domain object to initialize.
1856  * @gov: PM domain governor to associate with the domain (may be NULL).
1857  * @is_off: Initial value of the domain's power_is_off field.
1858  */
1859 void pm_genpd_init(struct generic_pm_domain *genpd,
1860                    struct dev_power_governor *gov, bool is_off)
1861 {
1862         if (IS_ERR_OR_NULL(genpd))
1863                 return;
1864
1865         INIT_LIST_HEAD(&genpd->master_links);
1866         INIT_LIST_HEAD(&genpd->slave_links);
1867         INIT_LIST_HEAD(&genpd->dev_list);
1868         mutex_init(&genpd->lock);
1869         genpd->gov = gov;
1870         INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
1871         genpd->in_progress = 0;
1872         atomic_set(&genpd->sd_count, 0);
1873         genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
1874         init_waitqueue_head(&genpd->status_wait_queue);
1875         genpd->poweroff_task = NULL;
1876         genpd->resume_count = 0;
1877         genpd->device_count = 0;
1878         genpd->max_off_time_ns = -1;
1879         genpd->max_off_time_changed = true;
1880         genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
1881         genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
1882         genpd->domain.ops.prepare = pm_genpd_prepare;
1883         genpd->domain.ops.suspend = pm_genpd_suspend;
1884         genpd->domain.ops.suspend_late = pm_genpd_suspend_late;
1885         genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq;
1886         genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq;
1887         genpd->domain.ops.resume_early = pm_genpd_resume_early;
1888         genpd->domain.ops.resume = pm_genpd_resume;
1889         genpd->domain.ops.freeze = pm_genpd_freeze;
1890         genpd->domain.ops.freeze_late = pm_genpd_freeze_late;
1891         genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq;
1892         genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq;
1893         genpd->domain.ops.thaw_early = pm_genpd_thaw_early;
1894         genpd->domain.ops.thaw = pm_genpd_thaw;
1895         genpd->domain.ops.poweroff = pm_genpd_suspend;
1896         genpd->domain.ops.poweroff_late = pm_genpd_suspend_late;
1897         genpd->domain.ops.poweroff_noirq = pm_genpd_suspend_noirq;
1898         genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
1899         genpd->domain.ops.restore_early = pm_genpd_resume_early;
1900         genpd->domain.ops.restore = pm_genpd_resume;
1901         genpd->domain.ops.complete = pm_genpd_complete;
1902         genpd->dev_ops.save_state = pm_genpd_default_save_state;
1903         genpd->dev_ops.restore_state = pm_genpd_default_restore_state;
1904
1905         if (genpd->flags & GENPD_FLAG_PM_CLK) {
1906                 genpd->dev_ops.stop = pm_clk_suspend;
1907                 genpd->dev_ops.start = pm_clk_resume;
1908         }
1909
1910         mutex_lock(&gpd_list_lock);
1911         list_add(&genpd->gpd_list_node, &gpd_list);
1912         mutex_unlock(&gpd_list_lock);
1913 }
1914
1915 #ifdef CONFIG_PM_GENERIC_DOMAINS_OF
1916 /*
1917  * Device Tree based PM domain providers.
1918  *
1919  * The code below implements generic device tree based PM domain providers that
1920  * bind device tree nodes with generic PM domains registered in the system.
1921  *
1922  * Any driver that registers generic PM domains and needs to support binding of
1923  * devices to these domains is supposed to register a PM domain provider, which
1924  * maps a PM domain specifier retrieved from the device tree to a PM domain.
1925  *
1926  * Two simple mapping functions have been provided for convenience:
1927  *  - __of_genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
1928  *  - __of_genpd_xlate_onecell() for mapping of multiple PM domains per node by
1929  *    index.
1930  */
1931
1932 /**
1933  * struct of_genpd_provider - PM domain provider registration structure
1934  * @link: Entry in global list of PM domain providers
1935  * @node: Pointer to device tree node of PM domain provider
1936  * @xlate: Provider-specific xlate callback mapping a set of specifier cells
1937  *         into a PM domain.
1938  * @data: context pointer to be passed into @xlate callback
1939  */
1940 struct of_genpd_provider {
1941         struct list_head link;
1942         struct device_node *node;
1943         genpd_xlate_t xlate;
1944         void *data;
1945 };
1946
1947 /* List of registered PM domain providers. */
1948 static LIST_HEAD(of_genpd_providers);
1949 /* Mutex to protect the list above. */
1950 static DEFINE_MUTEX(of_genpd_mutex);
1951
1952 /**
1953  * __of_genpd_xlate_simple() - Xlate function for direct node-domain mapping
1954  * @genpdspec: OF phandle args to map into a PM domain
1955  * @data: xlate function private data - pointer to struct generic_pm_domain
1956  *
1957  * This is a generic xlate function that can be used to model PM domains that
1958  * have their own device tree nodes. The private data of xlate function needs
1959  * to be a valid pointer to struct generic_pm_domain.
1960  */
1961 struct generic_pm_domain *__of_genpd_xlate_simple(
1962                                         struct of_phandle_args *genpdspec,
1963                                         void *data)
1964 {
1965         if (genpdspec->args_count != 0)
1966                 return ERR_PTR(-EINVAL);
1967         return data;
1968 }
1969 EXPORT_SYMBOL_GPL(__of_genpd_xlate_simple);
1970
1971 /**
1972  * __of_genpd_xlate_onecell() - Xlate function using a single index.
1973  * @genpdspec: OF phandle args to map into a PM domain
1974  * @data: xlate function private data - pointer to struct genpd_onecell_data
1975  *
1976  * This is a generic xlate function that can be used to model simple PM domain
1977  * controllers that have one device tree node and provide multiple PM domains.
1978  * A single cell is used as an index into an array of PM domains specified in
1979  * the genpd_onecell_data struct when registering the provider.
1980  */
1981 struct generic_pm_domain *__of_genpd_xlate_onecell(
1982                                         struct of_phandle_args *genpdspec,
1983                                         void *data)
1984 {
1985         struct genpd_onecell_data *genpd_data = data;
1986         unsigned int idx = genpdspec->args[0];
1987
1988         if (genpdspec->args_count != 1)
1989                 return ERR_PTR(-EINVAL);
1990
1991         if (idx >= genpd_data->num_domains) {
1992                 pr_err("%s: invalid domain index %u\n", __func__, idx);
1993                 return ERR_PTR(-EINVAL);
1994         }
1995
1996         if (!genpd_data->domains[idx])
1997                 return ERR_PTR(-ENOENT);
1998
1999         return genpd_data->domains[idx];
2000 }
2001 EXPORT_SYMBOL_GPL(__of_genpd_xlate_onecell);
2002
2003 /**
2004  * __of_genpd_add_provider() - Register a PM domain provider for a node
2005  * @np: Device node pointer associated with the PM domain provider.
2006  * @xlate: Callback for decoding PM domain from phandle arguments.
2007  * @data: Context pointer for @xlate callback.
2008  */
2009 int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
2010                         void *data)
2011 {
2012         struct of_genpd_provider *cp;
2013
2014         cp = kzalloc(sizeof(*cp), GFP_KERNEL);
2015         if (!cp)
2016                 return -ENOMEM;
2017
2018         cp->node = of_node_get(np);
2019         cp->data = data;
2020         cp->xlate = xlate;
2021
2022         mutex_lock(&of_genpd_mutex);
2023         list_add(&cp->link, &of_genpd_providers);
2024         mutex_unlock(&of_genpd_mutex);
2025         pr_debug("Added domain provider from %s\n", np->full_name);
2026
2027         return 0;
2028 }
2029 EXPORT_SYMBOL_GPL(__of_genpd_add_provider);
2030
2031 /**
2032  * of_genpd_del_provider() - Remove a previously registered PM domain provider
2033  * @np: Device node pointer associated with the PM domain provider
2034  */
2035 void of_genpd_del_provider(struct device_node *np)
2036 {
2037         struct of_genpd_provider *cp;
2038
2039         mutex_lock(&of_genpd_mutex);
2040         list_for_each_entry(cp, &of_genpd_providers, link) {
2041                 if (cp->node == np) {
2042                         list_del(&cp->link);
2043                         of_node_put(cp->node);
2044                         kfree(cp);
2045                         break;
2046                 }
2047         }
2048         mutex_unlock(&of_genpd_mutex);
2049 }
2050 EXPORT_SYMBOL_GPL(of_genpd_del_provider);
2051
2052 /**
2053  * of_genpd_get_from_provider() - Look-up PM domain
2054  * @genpdspec: OF phandle args to use for look-up
2055  *
2056  * Looks for a PM domain provider under the node specified by @genpdspec and if
2057  * found, uses xlate function of the provider to map phandle args to a PM
2058  * domain.
2059  *
2060  * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
2061  * on failure.
2062  */
2063 struct generic_pm_domain *of_genpd_get_from_provider(
2064                                         struct of_phandle_args *genpdspec)
2065 {
2066         struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
2067         struct of_genpd_provider *provider;
2068
2069         mutex_lock(&of_genpd_mutex);
2070
2071         /* Check if we have such a provider in our array */
2072         list_for_each_entry(provider, &of_genpd_providers, link) {
2073                 if (provider->node == genpdspec->np)
2074                         genpd = provider->xlate(genpdspec, provider->data);
2075                 if (!IS_ERR(genpd))
2076                         break;
2077         }
2078
2079         mutex_unlock(&of_genpd_mutex);
2080
2081         return genpd;
2082 }
2083 EXPORT_SYMBOL_GPL(of_genpd_get_from_provider);
2084
2085 /**
2086  * genpd_dev_pm_detach - Detach a device from its PM domain.
2087  * @dev: Device to attach.
2088  * @power_off: Currently not used
2089  *
2090  * Try to locate a corresponding generic PM domain, which the device was
2091  * attached to previously. If such is found, the device is detached from it.
2092  */
2093 static void genpd_dev_pm_detach(struct device *dev, bool power_off)
2094 {
2095         struct generic_pm_domain *pd = NULL, *gpd;
2096         int ret = 0;
2097
2098         if (!dev->pm_domain)
2099                 return;
2100
2101         mutex_lock(&gpd_list_lock);
2102         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
2103                 if (&gpd->domain == dev->pm_domain) {
2104                         pd = gpd;
2105                         break;
2106                 }
2107         }
2108         mutex_unlock(&gpd_list_lock);
2109
2110         if (!pd)
2111                 return;
2112
2113         dev_dbg(dev, "removing from PM domain %s\n", pd->name);
2114
2115         while (1) {
2116                 ret = pm_genpd_remove_device(pd, dev);
2117                 if (ret != -EAGAIN)
2118                         break;
2119                 cond_resched();
2120         }
2121
2122         if (ret < 0) {
2123                 dev_err(dev, "failed to remove from PM domain %s: %d",
2124                         pd->name, ret);
2125                 return;
2126         }
2127
2128         /* Check if PM domain can be powered off after removing this device. */
2129         genpd_queue_power_off_work(pd);
2130 }
2131
2132 /**
2133  * genpd_dev_pm_attach - Attach a device to its PM domain using DT.
2134  * @dev: Device to attach.
2135  *
2136  * Parse device's OF node to find a PM domain specifier. If such is found,
2137  * attaches the device to retrieved pm_domain ops.
2138  *
2139  * Both generic and legacy Samsung-specific DT bindings are supported to keep
2140  * backwards compatibility with existing DTBs.
2141  *
2142  * Returns 0 on successfully attached PM domain or negative error code.
2143  */
2144 int genpd_dev_pm_attach(struct device *dev)
2145 {
2146         struct of_phandle_args pd_args;
2147         struct generic_pm_domain *pd;
2148         int ret;
2149
2150         if (!dev->of_node)
2151                 return -ENODEV;
2152
2153         if (dev->pm_domain)
2154                 return -EEXIST;
2155
2156         ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
2157                                         "#power-domain-cells", 0, &pd_args);
2158         if (ret < 0) {
2159                 if (ret != -ENOENT)
2160                         return ret;
2161
2162                 /*
2163                  * Try legacy Samsung-specific bindings
2164                  * (for backwards compatibility of DT ABI)
2165                  */
2166                 pd_args.args_count = 0;
2167                 pd_args.np = of_parse_phandle(dev->of_node,
2168                                                 "samsung,power-domain", 0);
2169                 if (!pd_args.np)
2170                         return -ENOENT;
2171         }
2172
2173         pd = of_genpd_get_from_provider(&pd_args);
2174         if (IS_ERR(pd)) {
2175                 dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
2176                         __func__, PTR_ERR(pd));
2177                 of_node_put(dev->of_node);
2178                 return PTR_ERR(pd);
2179         }
2180
2181         dev_dbg(dev, "adding to PM domain %s\n", pd->name);
2182
2183         while (1) {
2184                 ret = pm_genpd_add_device(pd, dev);
2185                 if (ret != -EAGAIN)
2186                         break;
2187                 cond_resched();
2188         }
2189
2190         if (ret < 0) {
2191                 dev_err(dev, "failed to add to PM domain %s: %d",
2192                         pd->name, ret);
2193                 of_node_put(dev->of_node);
2194                 return ret;
2195         }
2196
2197         dev->pm_domain->detach = genpd_dev_pm_detach;
2198         pm_genpd_poweron(pd);
2199
2200         return 0;
2201 }
2202 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
2203 #endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
2204
2205
2206 /***        debugfs support        ***/
2207
2208 #ifdef CONFIG_PM_ADVANCED_DEBUG
2209 #include <linux/pm.h>
2210 #include <linux/device.h>
2211 #include <linux/debugfs.h>
2212 #include <linux/seq_file.h>
2213 #include <linux/init.h>
2214 #include <linux/kobject.h>
2215 static struct dentry *pm_genpd_debugfs_dir;
2216
2217 /*
2218  * TODO: This function is a slightly modified version of rtpm_status_show
2219  * from sysfs.c, so generalize it.
2220  */
2221 static void rtpm_status_str(struct seq_file *s, struct device *dev)
2222 {
2223         static const char * const status_lookup[] = {
2224                 [RPM_ACTIVE] = "active",
2225                 [RPM_RESUMING] = "resuming",
2226                 [RPM_SUSPENDED] = "suspended",
2227                 [RPM_SUSPENDING] = "suspending"
2228         };
2229         const char *p = "";
2230
2231         if (dev->power.runtime_error)
2232                 p = "error";
2233         else if (dev->power.disable_depth)
2234                 p = "unsupported";
2235         else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup))
2236                 p = status_lookup[dev->power.runtime_status];
2237         else
2238                 WARN_ON(1);
2239
2240         seq_puts(s, p);
2241 }
2242
2243 static int pm_genpd_summary_one(struct seq_file *s,
2244                 struct generic_pm_domain *gpd)
2245 {
2246         static const char * const status_lookup[] = {
2247                 [GPD_STATE_ACTIVE] = "on",
2248                 [GPD_STATE_WAIT_MASTER] = "wait-master",
2249                 [GPD_STATE_BUSY] = "busy",
2250                 [GPD_STATE_REPEAT] = "off-in-progress",
2251                 [GPD_STATE_POWER_OFF] = "off"
2252         };
2253         struct pm_domain_data *pm_data;
2254         const char *kobj_path;
2255         struct gpd_link *link;
2256         int ret;
2257
2258         ret = mutex_lock_interruptible(&gpd->lock);
2259         if (ret)
2260                 return -ERESTARTSYS;
2261
2262         if (WARN_ON(gpd->status >= ARRAY_SIZE(status_lookup)))
2263                 goto exit;
2264         seq_printf(s, "%-30s  %-15s  ", gpd->name, status_lookup[gpd->status]);
2265
2266         /*
2267          * Modifications on the list require holding locks on both
2268          * master and slave, so we are safe.
2269          * Also gpd->name is immutable.
2270          */
2271         list_for_each_entry(link, &gpd->master_links, master_node) {
2272                 seq_printf(s, "%s", link->slave->name);
2273                 if (!list_is_last(&link->master_node, &gpd->master_links))
2274                         seq_puts(s, ", ");
2275         }
2276
2277         list_for_each_entry(pm_data, &gpd->dev_list, list_node) {
2278                 kobj_path = kobject_get_path(&pm_data->dev->kobj, GFP_KERNEL);
2279                 if (kobj_path == NULL)
2280                         continue;
2281
2282                 seq_printf(s, "\n    %-50s  ", kobj_path);
2283                 rtpm_status_str(s, pm_data->dev);
2284                 kfree(kobj_path);
2285         }
2286
2287         seq_puts(s, "\n");
2288 exit:
2289         mutex_unlock(&gpd->lock);
2290
2291         return 0;
2292 }
2293
2294 static int pm_genpd_summary_show(struct seq_file *s, void *data)
2295 {
2296         struct generic_pm_domain *gpd;
2297         int ret = 0;
2298
2299         seq_puts(s, "    domain                      status         slaves\n");
2300         seq_puts(s, "           /device                                      runtime status\n");
2301         seq_puts(s, "----------------------------------------------------------------------\n");
2302
2303         ret = mutex_lock_interruptible(&gpd_list_lock);
2304         if (ret)
2305                 return -ERESTARTSYS;
2306
2307         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
2308                 ret = pm_genpd_summary_one(s, gpd);
2309                 if (ret)
2310                         break;
2311         }
2312         mutex_unlock(&gpd_list_lock);
2313
2314         return ret;
2315 }
2316
2317 static int pm_genpd_summary_open(struct inode *inode, struct file *file)
2318 {
2319         return single_open(file, pm_genpd_summary_show, NULL);
2320 }
2321
2322 static const struct file_operations pm_genpd_summary_fops = {
2323         .open = pm_genpd_summary_open,
2324         .read = seq_read,
2325         .llseek = seq_lseek,
2326         .release = single_release,
2327 };
2328
2329 static int __init pm_genpd_debug_init(void)
2330 {
2331         struct dentry *d;
2332
2333         pm_genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL);
2334
2335         if (!pm_genpd_debugfs_dir)
2336                 return -ENOMEM;
2337
2338         d = debugfs_create_file("pm_genpd_summary", S_IRUGO,
2339                         pm_genpd_debugfs_dir, NULL, &pm_genpd_summary_fops);
2340         if (!d)
2341                 return -ENOMEM;
2342
2343         return 0;
2344 }
2345 late_initcall(pm_genpd_debug_init);
2346
2347 static void __exit pm_genpd_debug_exit(void)
2348 {
2349         debugfs_remove_recursive(pm_genpd_debugfs_dir);
2350 }
2351 __exitcall(pm_genpd_debug_exit);
2352 #endif /* CONFIG_PM_ADVANCED_DEBUG */