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/slab.h>
  16 #include <linux/err.h>
  17 #include <linux/sched.h>
  18 #include <linux/suspend.h>
  19 #include <linux/export.h>
  20
  21 #define GENPD_DEV_CALLBACK(genpd, type, callback, dev)          \
  22 ({                                                              \
  23         type (*__routine)(struct device *__d);                  \
  24         type __ret = (type)0;                                   \
  25                                                                 \
  26         __routine = genpd->dev_ops.callback;                    \
  27         if (__routine) {                                        \
  28                 __ret = __routine(dev);                         \
  29         }                                                       \
  30         __ret;                                                  \
  31 })
  32
  33 #define GENPD_DEV_TIMED_CALLBACK(genpd, type, callback, dev, field, name)       \
  34 ({                                                                              \
  35         ktime_t __start = ktime_get();                                          \
  36         type __retval = GENPD_DEV_CALLBACK(genpd, type, callback, dev);         \
  37         s64 __elapsed = ktime_to_ns(ktime_sub(ktime_get(), __start));           \
  38         struct gpd_timing_data *__td = &dev_gpd_data(dev)->td;                  \
  39         if (!__retval && __elapsed > __td->field) {                             \
  40                 __td->field = __elapsed;                                        \
  41                 dev_dbg(dev, name " latency exceeded, new value %lld ns\n",     \
  42                         __elapsed);                                             \
  43                 genpd->max_off_time_changed = true;                             \
  44                 __td->constraint_changed = true;                                \
  45         }                                                                       \
  46         __retval;                                                               \
  47 })
  48
  49 static LIST_HEAD(gpd_list);
  50 static DEFINE_MUTEX(gpd_list_lock);
  51
  52 static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
  53 {
  54         struct generic_pm_domain *genpd = NULL, *gpd;
  55
  56         if (IS_ERR_OR_NULL(domain_name))
  57                 return NULL;
  58
  59         mutex_lock(&gpd_list_lock);
  60         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
  61                 if (!strcmp(gpd->name, domain_name)) {
  62                         genpd = gpd;
  63                         break;
  64                 }
  65         }
  66         mutex_unlock(&gpd_list_lock);
  67         return genpd;
  68 }
  69
  70 struct generic_pm_domain *dev_to_genpd(struct device *dev)
  71 {
  72         if (IS_ERR_OR_NULL(dev->pm_domain))
  73                 return ERR_PTR(-EINVAL);
  74
  75         return pd_to_genpd(dev->pm_domain);
  76 }
  77
  78 static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev)
  79 {
  80         return GENPD_DEV_TIMED_CALLBACK(genpd, int, stop, dev,
  81                                         stop_latency_ns, "stop");
  82 }
  83
  84 static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev)
  85 {
  86         return GENPD_DEV_TIMED_CALLBACK(genpd, int, start, dev,
  87                                         start_latency_ns, "start");
  88 }
  89
  90 static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
  91 {
  92         bool ret = false;
  93
  94         if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
  95                 ret = !!atomic_dec_and_test(&genpd->sd_count);
  96
  97         return ret;
  98 }
  99
 100 static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
 101 {
 102         atomic_inc(&genpd->sd_count);
 103         smp_mb__after_atomic();
 104 }
 105
 106 static void genpd_acquire_lock(struct generic_pm_domain *genpd)
 107 {
 108         DEFINE_WAIT(wait);
 109
 110         mutex_lock(&genpd->lock);
 111         /*
 112          * Wait for the domain to transition into either the active,
 113          * or the power off state.
 114          */
 115         for (;;) {
 116                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 117                                 TASK_UNINTERRUPTIBLE);
 118                 if (genpd->status == GPD_STATE_ACTIVE
 119                     || genpd->status == GPD_STATE_POWER_OFF)
 120                         break;
 121                 mutex_unlock(&genpd->lock);
 122
 123                 schedule();
 124
 125                 mutex_lock(&genpd->lock);
 126         }
 127         finish_wait(&genpd->status_wait_queue, &wait);
 128 }
 129
 130 static void genpd_release_lock(struct generic_pm_domain *genpd)
 131 {
 132         mutex_unlock(&genpd->lock);
 133 }
 134
 135 static void genpd_set_active(struct generic_pm_domain *genpd)
 136 {
 137         if (genpd->resume_count == 0)
 138                 genpd->status = GPD_STATE_ACTIVE;
 139 }
 140
 141 static void genpd_recalc_cpu_exit_latency(struct generic_pm_domain *genpd)
 142 {
 143         s64 usecs64;
 144
 145         if (!genpd->cpuidle_data)
 146                 return;
 147
 148         usecs64 = genpd->power_on_latency_ns;
 149         do_div(usecs64, NSEC_PER_USEC);
 150         usecs64 += genpd->cpuidle_data->saved_exit_latency;
 151         genpd->cpuidle_data->idle_state->exit_latency = usecs64;
 152 }
 153
 154 /**
 155  * __pm_genpd_poweron - Restore power to a given PM domain and its masters.
 156  * @genpd: PM domain to power up.
 157  *
 158  * Restore power to @genpd and all of its masters so that it is possible to
 159  * resume a device belonging to it.
 160  */
 161 static int __pm_genpd_poweron(struct generic_pm_domain *genpd)
 162         __releases(&genpd->lock) __acquires(&genpd->lock)
 163 {
 164         struct gpd_link *link;
 165         DEFINE_WAIT(wait);
 166         int ret = 0;
 167
 168         /* If the domain's master is being waited for, we have to wait too. */
 169         for (;;) {
 170                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 171                                 TASK_UNINTERRUPTIBLE);
 172                 if (genpd->status != GPD_STATE_WAIT_MASTER)
 173                         break;
 174                 mutex_unlock(&genpd->lock);
 175
 176                 schedule();
 177
 178                 mutex_lock(&genpd->lock);
 179         }
 180         finish_wait(&genpd->status_wait_queue, &wait);
 181
 182         if (genpd->status == GPD_STATE_ACTIVE
 183             || (genpd->prepared_count > 0 && genpd->suspend_power_off))
 184                 return 0;
 185
 186         if (genpd->status != GPD_STATE_POWER_OFF) {
 187                 genpd_set_active(genpd);
 188                 return 0;
 189         }
 190
 191         if (genpd->cpuidle_data) {
 192                 cpuidle_pause_and_lock();
 193                 genpd->cpuidle_data->idle_state->disabled = true;
 194                 cpuidle_resume_and_unlock();
 195                 goto out;
 196         }
 197
 198         /*
 199          * The list is guaranteed not to change while the loop below is being
 200          * executed, unless one of the masters' .power_on() callbacks fiddles
 201          * with it.
 202          */
 203         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 204                 genpd_sd_counter_inc(link->master);
 205                 genpd->status = GPD_STATE_WAIT_MASTER;
 206
 207                 mutex_unlock(&genpd->lock);
 208
 209                 ret = pm_genpd_poweron(link->master);
 210
 211                 mutex_lock(&genpd->lock);
 212
 213                 /*
 214                  * The "wait for parent" status is guaranteed not to change
 215                  * while the master is powering on.
 216                  */
 217                 genpd->status = GPD_STATE_POWER_OFF;
 218                 wake_up_all(&genpd->status_wait_queue);
 219                 if (ret) {
 220                         genpd_sd_counter_dec(link->master);
 221                         goto err;
 222                 }
 223         }
 224
 225         if (genpd->power_on) {
 226                 ktime_t time_start = ktime_get();
 227                 s64 elapsed_ns;
 228
 229                 ret = genpd->power_on(genpd);
 230                 if (ret)
 231                         goto err;
 232
 233                 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 234                 if (elapsed_ns > genpd->power_on_latency_ns) {
 235                         genpd->power_on_latency_ns = elapsed_ns;
 236                         genpd->max_off_time_changed = true;
 237                         genpd_recalc_cpu_exit_latency(genpd);
 238                         if (genpd->name)
 239                                 pr_warning("%s: Power-on latency exceeded, "
 240                                         "new value %lld ns\n", genpd->name,
 241                                         elapsed_ns);
 242                 }
 243         }
 244
 245  out:
 246         genpd_set_active(genpd);
 247
 248         return 0;
 249
 250  err:
 251         list_for_each_entry_continue_reverse(link, &genpd->slave_links, slave_node)
 252                 genpd_sd_counter_dec(link->master);
 253
 254         return ret;
 255 }
 256
 257 /**
 258  * pm_genpd_poweron - Restore power to a given PM domain and its masters.
 259  * @genpd: PM domain to power up.
 260  */
 261 int pm_genpd_poweron(struct generic_pm_domain *genpd)
 262 {
 263         int ret;
 264
 265         mutex_lock(&genpd->lock);
 266         ret = __pm_genpd_poweron(genpd);
 267         mutex_unlock(&genpd->lock);
 268         return ret;
 269 }
 270
 271 /**
 272  * pm_genpd_name_poweron - Restore power to a given PM domain and its masters.
 273  * @domain_name: Name of the PM domain to power up.
 274  */
 275 int pm_genpd_name_poweron(const char *domain_name)
 276 {
 277         struct generic_pm_domain *genpd;
 278
 279         genpd = pm_genpd_lookup_name(domain_name);
 280         return genpd ? pm_genpd_poweron(genpd) : -EINVAL;
 281 }
 282
 283 #ifdef CONFIG_PM_RUNTIME
 284
 285 static int genpd_start_dev_no_timing(struct generic_pm_domain *genpd,
 286                                      struct device *dev)
 287 {
 288         return GENPD_DEV_CALLBACK(genpd, int, start, dev);
 289 }
 290
 291 static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev)
 292 {
 293         return GENPD_DEV_TIMED_CALLBACK(genpd, int, save_state, dev,
 294                                         save_state_latency_ns, "state save");
 295 }
 296
 297 static int genpd_restore_dev(struct generic_pm_domain *genpd, struct device *dev)
 298 {
 299         return GENPD_DEV_TIMED_CALLBACK(genpd, int, restore_state, dev,
 300                                         restore_state_latency_ns,
 301                                         "state restore");
 302 }
 303
 304 static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
 305                                      unsigned long val, void *ptr)
 306 {
 307         struct generic_pm_domain_data *gpd_data;
 308         struct device *dev;
 309
 310         gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
 311
 312         mutex_lock(&gpd_data->lock);
 313         dev = gpd_data->base.dev;
 314         if (!dev) {
 315                 mutex_unlock(&gpd_data->lock);
 316                 return NOTIFY_DONE;
 317         }
 318         mutex_unlock(&gpd_data->lock);
 319
 320         for (;;) {
 321                 struct generic_pm_domain *genpd;
 322                 struct pm_domain_data *pdd;
 323
 324                 spin_lock_irq(&dev->power.lock);
 325
 326                 pdd = dev->power.subsys_data ?
 327                                 dev->power.subsys_data->domain_data : NULL;
 328                 if (pdd && pdd->dev) {
 329                         to_gpd_data(pdd)->td.constraint_changed = true;
 330                         genpd = dev_to_genpd(dev);
 331                 } else {
 332                         genpd = ERR_PTR(-ENODATA);
 333                 }
 334
 335                 spin_unlock_irq(&dev->power.lock);
 336
 337                 if (!IS_ERR(genpd)) {
 338                         mutex_lock(&genpd->lock);
 339                         genpd->max_off_time_changed = true;
 340                         mutex_unlock(&genpd->lock);
 341                 }
 342
 343                 dev = dev->parent;
 344                 if (!dev || dev->power.ignore_children)
 345                         break;
 346         }
 347
 348         return NOTIFY_DONE;
 349 }
 350
 351 /**
 352  * __pm_genpd_save_device - Save the pre-suspend state of a device.
 353  * @pdd: Domain data of the device to save the state of.
 354  * @genpd: PM domain the device belongs to.
 355  */
 356 static int __pm_genpd_save_device(struct pm_domain_data *pdd,
 357                                   struct generic_pm_domain *genpd)
 358         __releases(&genpd->lock) __acquires(&genpd->lock)
 359 {
 360         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 361         struct device *dev = pdd->dev;
 362         int ret = 0;
 363
 364         if (gpd_data->need_restore > 0)
 365                 return 0;
 366
 367         /*
 368          * If the value of the need_restore flag is still unknown at this point,
 369          * we trust that pm_genpd_poweroff() has verified that the device is
 370          * already runtime PM suspended.
 371          */
 372         if (gpd_data->need_restore < 0) {
 373                 gpd_data->need_restore = 1;
 374                 return 0;
 375         }
 376
 377         mutex_unlock(&genpd->lock);
 378
 379         genpd_start_dev(genpd, dev);
 380         ret = genpd_save_dev(genpd, dev);
 381         genpd_stop_dev(genpd, dev);
 382
 383         mutex_lock(&genpd->lock);
 384
 385         if (!ret)
 386                 gpd_data->need_restore = 1;
 387
 388         return ret;
 389 }
 390
 391 /**
 392  * __pm_genpd_restore_device - Restore the pre-suspend state of a device.
 393  * @pdd: Domain data of the device to restore the state of.
 394  * @genpd: PM domain the device belongs to.
 395  */
 396 static void __pm_genpd_restore_device(struct pm_domain_data *pdd,
 397                                       struct generic_pm_domain *genpd)
 398         __releases(&genpd->lock) __acquires(&genpd->lock)
 399 {
 400         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 401         struct device *dev = pdd->dev;
 402         int need_restore = gpd_data->need_restore;
 403
 404         gpd_data->need_restore = 0;
 405         mutex_unlock(&genpd->lock);
 406
 407         genpd_start_dev(genpd, dev);
 408
 409         /*
 410          * Call genpd_restore_dev() for recently added devices too (need_restore
 411          * is negative then).
 412          */
 413         if (need_restore)
 414                 genpd_restore_dev(genpd, dev);
 415
 416         mutex_lock(&genpd->lock);
 417 }
 418
 419 /**
 420  * genpd_abort_poweroff - Check if a PM domain power off should be aborted.
 421  * @genpd: PM domain to check.
 422  *
 423  * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during
 424  * a "power off" operation, which means that a "power on" has occured in the
 425  * meantime, or if its resume_count field is different from zero, which means
 426  * that one of its devices has been resumed in the meantime.
 427  */
 428 static bool genpd_abort_poweroff(struct generic_pm_domain *genpd)
 429 {
 430         return genpd->status == GPD_STATE_WAIT_MASTER
 431                 || genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0;
 432 }
 433
 434 /**
 435  * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff().
 436  * @genpd: PM domait to power off.
 437  *
 438  * Queue up the execution of pm_genpd_poweroff() unless it's already been done
 439  * before.
 440  */
 441 static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
 442 {
 443         queue_work(pm_wq, &genpd->power_off_work);
 444 }
 445
 446 /**
 447  * pm_genpd_poweroff - Remove power from a given PM domain.
 448  * @genpd: PM domain to power down.
 449  *
 450  * If all of the @genpd's devices have been suspended and all of its subdomains
 451  * have been powered down, run the runtime suspend callbacks provided by all of
 452  * the @genpd's devices' drivers and remove power from @genpd.
 453  */
 454 static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
 455         __releases(&genpd->lock) __acquires(&genpd->lock)
 456 {
 457         struct pm_domain_data *pdd;
 458         struct gpd_link *link;
 459         unsigned int not_suspended;
 460         int ret = 0;
 461
 462  start:
 463         /*
 464          * Do not try to power off the domain in the following situations:
 465          * (1) The domain is already in the "power off" state.
 466          * (2) The domain is waiting for its master to power up.
 467          * (3) One of the domain's devices is being resumed right now.
 468          * (4) System suspend is in progress.
 469          */
 470         if (genpd->status == GPD_STATE_POWER_OFF
 471             || genpd->status == GPD_STATE_WAIT_MASTER
 472             || genpd->resume_count > 0 || genpd->prepared_count > 0)
 473                 return 0;
 474
 475         if (atomic_read(&genpd->sd_count) > 0)
 476                 return -EBUSY;
 477
 478         not_suspended = 0;
 479         list_for_each_entry(pdd, &genpd->dev_list, list_node) {
 480                 enum pm_qos_flags_status stat;
 481
 482                 stat = dev_pm_qos_flags(pdd->dev,
 483                                         PM_QOS_FLAG_NO_POWER_OFF
 484                                                 | PM_QOS_FLAG_REMOTE_WAKEUP);
 485                 if (stat > PM_QOS_FLAGS_NONE)
 486                         return -EBUSY;
 487
 488                 if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
 489                     || pdd->dev->power.irq_safe))
 490                         not_suspended++;
 491         }
 492
 493         if (not_suspended > genpd->in_progress)
 494                 return -EBUSY;
 495
 496         if (genpd->poweroff_task) {
 497                 /*
 498                  * Another instance of pm_genpd_poweroff() is executing
 499                  * callbacks, so tell it to start over and return.
 500                  */
 501                 genpd->status = GPD_STATE_REPEAT;
 502                 return 0;
 503         }
 504
 505         if (genpd->gov && genpd->gov->power_down_ok) {
 506                 if (!genpd->gov->power_down_ok(&genpd->domain))
 507                         return -EAGAIN;
 508         }
 509
 510         genpd->status = GPD_STATE_BUSY;
 511         genpd->poweroff_task = current;
 512
 513         list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) {
 514                 ret = atomic_read(&genpd->sd_count) == 0 ?
 515                         __pm_genpd_save_device(pdd, genpd) : -EBUSY;
 516
 517                 if (genpd_abort_poweroff(genpd))
 518                         goto out;
 519
 520                 if (ret) {
 521                         genpd_set_active(genpd);
 522                         goto out;
 523                 }
 524
 525                 if (genpd->status == GPD_STATE_REPEAT) {
 526                         genpd->poweroff_task = NULL;
 527                         goto start;
 528                 }
 529         }
 530
 531         if (genpd->cpuidle_data) {
 532                 /*
 533                  * If cpuidle_data is set, cpuidle should turn the domain off
 534                  * when the CPU in it is idle.  In that case we don't decrement
 535                  * the subdomain counts of the master domains, so that power is
 536                  * not removed from the current domain prematurely as a result
 537                  * of cutting off the masters' power.
 538                  */
 539                 genpd->status = GPD_STATE_POWER_OFF;
 540                 cpuidle_pause_and_lock();
 541                 genpd->cpuidle_data->idle_state->disabled = false;
 542                 cpuidle_resume_and_unlock();
 543                 goto out;
 544         }
 545
 546         if (genpd->power_off) {
 547                 ktime_t time_start;
 548                 s64 elapsed_ns;
 549
 550                 if (atomic_read(&genpd->sd_count) > 0) {
 551                         ret = -EBUSY;
 552                         goto out;
 553                 }
 554
 555                 time_start = ktime_get();
 556
 557                 /*
 558                  * If sd_count > 0 at this point, one of the subdomains hasn't
 559                  * managed to call pm_genpd_poweron() for the master yet after
 560                  * incrementing it.  In that case pm_genpd_poweron() will wait
 561                  * for us to drop the lock, so we can call .power_off() and let
 562                  * the pm_genpd_poweron() restore power for us (this shouldn't
 563                  * happen very often).
 564                  */
 565                 ret = genpd->power_off(genpd);
 566                 if (ret == -EBUSY) {
 567                         genpd_set_active(genpd);
 568                         goto out;
 569                 }
 570
 571                 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 572                 if (elapsed_ns > genpd->power_off_latency_ns) {
 573                         genpd->power_off_latency_ns = elapsed_ns;
 574                         genpd->max_off_time_changed = true;
 575                         if (genpd->name)
 576                                 pr_warning("%s: Power-off latency exceeded, "
 577                                         "new value %lld ns\n", genpd->name,
 578                                         elapsed_ns);
 579                 }
 580         }
 581
 582         genpd->status = GPD_STATE_POWER_OFF;
 583
 584         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 585                 genpd_sd_counter_dec(link->master);
 586                 genpd_queue_power_off_work(link->master);
 587         }
 588
 589  out:
 590         genpd->poweroff_task = NULL;
 591         wake_up_all(&genpd->status_wait_queue);
 592         return ret;
 593 }
 594
 595 /**
 596  * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
 597  * @work: Work structure used for scheduling the execution of this function.
 598  */
 599 static void genpd_power_off_work_fn(struct work_struct *work)
 600 {
 601         struct generic_pm_domain *genpd;
 602
 603         genpd = container_of(work, struct generic_pm_domain, power_off_work);
 604
 605         genpd_acquire_lock(genpd);
 606         pm_genpd_poweroff(genpd);
 607         genpd_release_lock(genpd);
 608 }
 609
 610 /**
 611  * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
 612  * @dev: Device to suspend.
 613  *
 614  * Carry out a runtime suspend of a device under the assumption that its
 615  * pm_domain field points to the domain member of an object of type
 616  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 617  */
 618 static int pm_genpd_runtime_suspend(struct device *dev)
 619 {
 620         struct generic_pm_domain *genpd;
 621         struct generic_pm_domain_data *gpd_data;
 622         bool (*stop_ok)(struct device *__dev);
 623         int ret;
 624
 625         dev_dbg(dev, "%s()\n", __func__);
 626
 627         genpd = dev_to_genpd(dev);
 628         if (IS_ERR(genpd))
 629                 return -EINVAL;
 630
 631         stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
 632         if (stop_ok && !stop_ok(dev))
 633                 return -EBUSY;
 634
 635         ret = genpd_stop_dev(genpd, dev);
 636         if (ret)
 637                 return ret;
 638
 639         /*
 640          * If power.irq_safe is set, this routine will be run with interrupts
 641          * off, so it can't use mutexes.
 642          */
 643         if (dev->power.irq_safe)
 644                 return 0;
 645
 646         mutex_lock(&genpd->lock);
 647
 648         /*
 649          * If we have an unknown state of the need_restore flag, it means none
 650          * of the runtime PM callbacks has been invoked yet. Let's update the
 651          * flag to reflect that the current state is active.
 652          */
 653         gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
 654         if (gpd_data->need_restore < 0)
 655                 gpd_data->need_restore = 0;
 656
 657         genpd->in_progress++;
 658         pm_genpd_poweroff(genpd);
 659         genpd->in_progress--;
 660         mutex_unlock(&genpd->lock);
 661
 662         return 0;
 663 }
 664
 665 /**
 666  * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
 667  * @dev: Device to resume.
 668  *
 669  * Carry out a runtime resume of a device under the assumption that its
 670  * pm_domain field points to the domain member of an object of type
 671  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 672  */
 673 static int pm_genpd_runtime_resume(struct device *dev)
 674 {
 675         struct generic_pm_domain *genpd;
 676         DEFINE_WAIT(wait);
 677         int ret;
 678
 679         dev_dbg(dev, "%s()\n", __func__);
 680
 681         genpd = dev_to_genpd(dev);
 682         if (IS_ERR(genpd))
 683                 return -EINVAL;
 684
 685         /* If power.irq_safe, the PM domain is never powered off. */
 686         if (dev->power.irq_safe)
 687                 return genpd_start_dev_no_timing(genpd, dev);
 688
 689         mutex_lock(&genpd->lock);
 690         ret = __pm_genpd_poweron(genpd);
 691         if (ret) {
 692                 mutex_unlock(&genpd->lock);
 693                 return ret;
 694         }
 695         genpd->status = GPD_STATE_BUSY;
 696         genpd->resume_count++;
 697         for (;;) {
 698                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 699                                 TASK_UNINTERRUPTIBLE);
 700                 /*
 701                  * If current is the powering off task, we have been called
 702                  * reentrantly from one of the device callbacks, so we should
 703                  * not wait.
 704                  */
 705                 if (!genpd->poweroff_task || genpd->poweroff_task == current)
 706                         break;
 707                 mutex_unlock(&genpd->lock);
 708
 709                 schedule();
 710
 711                 mutex_lock(&genpd->lock);
 712         }
 713         finish_wait(&genpd->status_wait_queue, &wait);
 714         __pm_genpd_restore_device(dev->power.subsys_data->domain_data, genpd);
 715         genpd->resume_count--;
 716         genpd_set_active(genpd);
 717         wake_up_all(&genpd->status_wait_queue);
 718         mutex_unlock(&genpd->lock);
 719
 720         return 0;
 721 }
 722
 723 static bool pd_ignore_unused;
 724 static int __init pd_ignore_unused_setup(char *__unused)
 725 {
 726         pd_ignore_unused = true;
 727         return 1;
 728 }
 729 __setup("pd_ignore_unused", pd_ignore_unused_setup);
 730
 731 /**
 732  * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use.
 733  */
 734 void pm_genpd_poweroff_unused(void)
 735 {
 736         struct generic_pm_domain *genpd;
 737
 738         if (pd_ignore_unused) {
 739                 pr_warn("genpd: Not disabling unused power domains\n");
 740                 return;
 741         }
 742
 743         mutex_lock(&gpd_list_lock);
 744
 745         list_for_each_entry(genpd, &gpd_list, gpd_list_node)
 746                 genpd_queue_power_off_work(genpd);
 747
 748         mutex_unlock(&gpd_list_lock);
 749 }
 750
 751 static int __init genpd_poweroff_unused(void)
 752 {
 753         pm_genpd_poweroff_unused();
 754         return 0;
 755 }
 756 late_initcall(genpd_poweroff_unused);
 757
 758 #else
 759
 760 static inline int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
 761                                             unsigned long val, void *ptr)
 762 {
 763         return NOTIFY_DONE;
 764 }
 765
 766 static inline void
 767 genpd_queue_power_off_work(struct generic_pm_domain *genpd) {}
 768
 769 static inline void genpd_power_off_work_fn(struct work_struct *work) {}
 770
 771 #define pm_genpd_runtime_suspend        NULL
 772 #define pm_genpd_runtime_resume         NULL
 773
 774 #endif /* CONFIG_PM_RUNTIME */
 775
 776 #ifdef CONFIG_PM_SLEEP
 777
 778 /**
 779  * pm_genpd_present - Check if the given PM domain has been initialized.
 780  * @genpd: PM domain to check.
 781  */
 782 static bool pm_genpd_present(struct generic_pm_domain *genpd)
 783 {
 784         struct generic_pm_domain *gpd;
 785
 786         if (IS_ERR_OR_NULL(genpd))
 787                 return false;
 788
 789         list_for_each_entry(gpd, &gpd_list, gpd_list_node)
 790                 if (gpd == genpd)
 791                         return true;
 792
 793         return false;
 794 }
 795
 796 static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
 797                                     struct device *dev)
 798 {
 799         return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev);
 800 }
 801
 802 /**
 803  * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
 804  * @genpd: PM domain to power off, if possible.
 805  *
 806  * Check if the given PM domain can be powered off (during system suspend or
 807  * hibernation) and do that if so.  Also, in that case propagate to its masters.
 808  *
 809  * This function is only called in "noirq" and "syscore" stages of system power
 810  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 811  * executed sequentially, so it is guaranteed that it will never run twice in
 812  * parallel).
 813  */
 814 static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
 815 {
 816         struct gpd_link *link;
 817
 818         if (genpd->status == GPD_STATE_POWER_OFF)
 819                 return;
 820
 821         if (genpd->suspended_count != genpd->device_count
 822             || atomic_read(&genpd->sd_count) > 0)
 823                 return;
 824
 825         if (genpd->power_off)
 826                 genpd->power_off(genpd);
 827
 828         genpd->status = GPD_STATE_POWER_OFF;
 829
 830         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 831                 genpd_sd_counter_dec(link->master);
 832                 pm_genpd_sync_poweroff(link->master);
 833         }
 834 }
 835
 836 /**
 837  * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters.
 838  * @genpd: PM domain to power on.
 839  *
 840  * This function is only called in "noirq" and "syscore" stages of system power
 841  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 842  * executed sequentially, so it is guaranteed that it will never run twice in
 843  * parallel).
 844  */
 845 static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)
 846 {
 847         struct gpd_link *link;
 848
 849         if (genpd->status != GPD_STATE_POWER_OFF)
 850                 return;
 851
 852         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 853                 pm_genpd_sync_poweron(link->master);
 854                 genpd_sd_counter_inc(link->master);
 855         }
 856
 857         if (genpd->power_on)
 858                 genpd->power_on(genpd);
 859
 860         genpd->status = GPD_STATE_ACTIVE;
 861 }
 862
 863 /**
 864  * resume_needed - Check whether to resume a device before system suspend.
 865  * @dev: Device to check.
 866  * @genpd: PM domain the device belongs to.
 867  *
 868  * There are two cases in which a device that can wake up the system from sleep
 869  * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled
 870  * to wake up the system and it has to remain active for this purpose while the
 871  * system is in the sleep state and (2) if the device is not enabled to wake up
 872  * the system from sleep states and it generally doesn't generate wakeup signals
 873  * by itself (those signals are generated on its behalf by other parts of the
 874  * system).  In the latter case it may be necessary to reconfigure the device's
 875  * wakeup settings during system suspend, because it may have been set up to
 876  * signal remote wakeup from the system's working state as needed by runtime PM.
 877  * Return 'true' in either of the above cases.
 878  */
 879 static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd)
 880 {
 881         bool active_wakeup;
 882
 883         if (!device_can_wakeup(dev))
 884                 return false;
 885
 886         active_wakeup = genpd_dev_active_wakeup(genpd, dev);
 887         return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
 888 }
 889
 890 /**
 891  * pm_genpd_prepare - Start power transition of a device in a PM domain.
 892  * @dev: Device to start the transition of.
 893  *
 894  * Start a power transition of a device (during a system-wide power transition)
 895  * under the assumption that its pm_domain field points to the domain member of
 896  * an object of type struct generic_pm_domain representing a PM domain
 897  * consisting of I/O devices.
 898  */
 899 static int pm_genpd_prepare(struct device *dev)
 900 {
 901         struct generic_pm_domain *genpd;
 902         int ret;
 903
 904         dev_dbg(dev, "%s()\n", __func__);
 905
 906         genpd = dev_to_genpd(dev);
 907         if (IS_ERR(genpd))
 908                 return -EINVAL;
 909
 910         /*
 911          * If a wakeup request is pending for the device, it should be woken up
 912          * at this point and a system wakeup event should be reported if it's
 913          * set up to wake up the system from sleep states.
 914          */
 915         pm_runtime_get_noresume(dev);
 916         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
 917                 pm_wakeup_event(dev, 0);
 918
 919         if (pm_wakeup_pending()) {
 920                 pm_runtime_put(dev);
 921                 return -EBUSY;
 922         }
 923
 924         if (resume_needed(dev, genpd))
 925                 pm_runtime_resume(dev);
 926
 927         genpd_acquire_lock(genpd);
 928
 929         if (genpd->prepared_count++ == 0) {
 930                 genpd->suspended_count = 0;
 931                 genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF;
 932         }
 933
 934         genpd_release_lock(genpd);
 935
 936         if (genpd->suspend_power_off) {
 937                 pm_runtime_put_noidle(dev);
 938                 return 0;
 939         }
 940
 941         /*
 942          * The PM domain must be in the GPD_STATE_ACTIVE state at this point,
 943          * so pm_genpd_poweron() will return immediately, but if the device
 944          * is suspended (e.g. it's been stopped by genpd_stop_dev()), we need
 945          * to make it operational.
 946          */
 947         pm_runtime_resume(dev);
 948         __pm_runtime_disable(dev, false);
 949
 950         ret = pm_generic_prepare(dev);
 951         if (ret) {
 952                 mutex_lock(&genpd->lock);
 953
 954                 if (--genpd->prepared_count == 0)
 955                         genpd->suspend_power_off = false;
 956
 957                 mutex_unlock(&genpd->lock);
 958                 pm_runtime_enable(dev);
 959         }
 960
 961         pm_runtime_put(dev);
 962         return ret;
 963 }
 964
 965 /**
 966  * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain.
 967  * @dev: Device to suspend.
 968  *
 969  * Suspend a device under the assumption that its pm_domain field points to the
 970  * domain member of an object of type struct generic_pm_domain representing
 971  * a PM domain consisting of I/O devices.
 972  */
 973 static int pm_genpd_suspend(struct device *dev)
 974 {
 975         struct generic_pm_domain *genpd;
 976
 977         dev_dbg(dev, "%s()\n", __func__);
 978
 979         genpd = dev_to_genpd(dev);
 980         if (IS_ERR(genpd))
 981                 return -EINVAL;
 982
 983         return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev);
 984 }
 985
 986 /**
 987  * pm_genpd_suspend_late - Late suspend of a device from an I/O PM domain.
 988  * @dev: Device to suspend.
 989  *
 990  * Carry out a late suspend of a device under the assumption that its
 991  * pm_domain field points to the domain member of an object of type
 992  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 993  */
 994 static int pm_genpd_suspend_late(struct device *dev)
 995 {
 996         struct generic_pm_domain *genpd;
 997
 998         dev_dbg(dev, "%s()\n", __func__);
 999
1000         genpd = dev_to_genpd(dev);
1001         if (IS_ERR(genpd))
1002                 return -EINVAL;
1003
1004         return genpd->suspend_power_off ? 0 : pm_generic_suspend_late(dev);
1005 }
1006
1007 /**
1008  * pm_genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
1009  * @dev: Device to suspend.
1010  *
1011  * Stop the device and remove power from the domain if all devices in it have
1012  * been stopped.
1013  */
1014 static int pm_genpd_suspend_noirq(struct device *dev)
1015 {
1016         struct generic_pm_domain *genpd;
1017
1018         dev_dbg(dev, "%s()\n", __func__);
1019
1020         genpd = dev_to_genpd(dev);
1021         if (IS_ERR(genpd))
1022                 return -EINVAL;
1023
1024         if (genpd->suspend_power_off
1025             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1026                 return 0;
1027
1028         genpd_stop_dev(genpd, dev);
1029
1030         /*
1031          * Since all of the "noirq" callbacks are executed sequentially, it is
1032          * guaranteed that this function will never run twice in parallel for
1033          * the same PM domain, so it is not necessary to use locking here.
1034          */
1035         genpd->suspended_count++;
1036         pm_genpd_sync_poweroff(genpd);
1037
1038         return 0;
1039 }
1040
1041 /**
1042  * pm_genpd_resume_noirq - Start of resume of device in an I/O PM domain.
1043  * @dev: Device to resume.
1044  *
1045  * Restore power to the device's PM domain, if necessary, and start the device.
1046  */
1047 static int pm_genpd_resume_noirq(struct device *dev)
1048 {
1049         struct generic_pm_domain *genpd;
1050
1051         dev_dbg(dev, "%s()\n", __func__);
1052
1053         genpd = dev_to_genpd(dev);
1054         if (IS_ERR(genpd))
1055                 return -EINVAL;
1056
1057         if (genpd->suspend_power_off
1058             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1059                 return 0;
1060
1061         /*
1062          * Since all of the "noirq" callbacks are executed sequentially, it is
1063          * guaranteed that this function will never run twice in parallel for
1064          * the same PM domain, so it is not necessary to use locking here.
1065          */
1066         pm_genpd_sync_poweron(genpd);
1067         genpd->suspended_count--;
1068
1069         return genpd_start_dev(genpd, dev);
1070 }
1071
1072 /**
1073  * pm_genpd_resume_early - Early resume of a device in an I/O PM domain.
1074  * @dev: Device to resume.
1075  *
1076  * Carry out an early resume of a device under the assumption that its
1077  * pm_domain field points to the domain member of an object of type
1078  * struct generic_pm_domain representing a power domain consisting of I/O
1079  * devices.
1080  */
1081 static int pm_genpd_resume_early(struct device *dev)
1082 {
1083         struct generic_pm_domain *genpd;
1084
1085         dev_dbg(dev, "%s()\n", __func__);
1086
1087         genpd = dev_to_genpd(dev);
1088         if (IS_ERR(genpd))
1089                 return -EINVAL;
1090
1091         return genpd->suspend_power_off ? 0 : pm_generic_resume_early(dev);
1092 }
1093
1094 /**
1095  * pm_genpd_resume - Resume of device in an I/O PM domain.
1096  * @dev: Device to resume.
1097  *
1098  * Resume a device under the assumption that its pm_domain field points to the
1099  * domain member of an object of type struct generic_pm_domain representing
1100  * a power domain consisting of I/O devices.
1101  */
1102 static int pm_genpd_resume(struct device *dev)
1103 {
1104         struct generic_pm_domain *genpd;
1105
1106         dev_dbg(dev, "%s()\n", __func__);
1107
1108         genpd = dev_to_genpd(dev);
1109         if (IS_ERR(genpd))
1110                 return -EINVAL;
1111
1112         return genpd->suspend_power_off ? 0 : pm_generic_resume(dev);
1113 }
1114
1115 /**
1116  * pm_genpd_freeze - Freezing a device in an I/O PM domain.
1117  * @dev: Device to freeze.
1118  *
1119  * Freeze a device under the assumption that its pm_domain field points to the
1120  * domain member of an object of type struct generic_pm_domain representing
1121  * a power domain consisting of I/O devices.
1122  */
1123 static int pm_genpd_freeze(struct device *dev)
1124 {
1125         struct generic_pm_domain *genpd;
1126
1127         dev_dbg(dev, "%s()\n", __func__);
1128
1129         genpd = dev_to_genpd(dev);
1130         if (IS_ERR(genpd))
1131                 return -EINVAL;
1132
1133         return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev);
1134 }
1135
1136 /**
1137  * pm_genpd_freeze_late - Late freeze of a device in an I/O PM domain.
1138  * @dev: Device to freeze.
1139  *
1140  * Carry out a late freeze of a device under the assumption that its
1141  * pm_domain field points to the domain member of an object of type
1142  * struct generic_pm_domain representing a power domain consisting of I/O
1143  * devices.
1144  */
1145 static int pm_genpd_freeze_late(struct device *dev)
1146 {
1147         struct generic_pm_domain *genpd;
1148
1149         dev_dbg(dev, "%s()\n", __func__);
1150
1151         genpd = dev_to_genpd(dev);
1152         if (IS_ERR(genpd))
1153                 return -EINVAL;
1154
1155         return genpd->suspend_power_off ? 0 : pm_generic_freeze_late(dev);
1156 }
1157
1158 /**
1159  * pm_genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
1160  * @dev: Device to freeze.
1161  *
1162  * Carry out a late freeze of a device under the assumption that its
1163  * pm_domain field points to the domain member of an object of type
1164  * struct generic_pm_domain representing a power domain consisting of I/O
1165  * devices.
1166  */
1167 static int pm_genpd_freeze_noirq(struct device *dev)
1168 {
1169         struct generic_pm_domain *genpd;
1170
1171         dev_dbg(dev, "%s()\n", __func__);
1172
1173         genpd = dev_to_genpd(dev);
1174         if (IS_ERR(genpd))
1175                 return -EINVAL;
1176
1177         return genpd->suspend_power_off ? 0 : genpd_stop_dev(genpd, dev);
1178 }
1179
1180 /**
1181  * pm_genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
1182  * @dev: Device to thaw.
1183  *
1184  * Start the device, unless power has been removed from the domain already
1185  * before the system transition.
1186  */
1187 static int pm_genpd_thaw_noirq(struct device *dev)
1188 {
1189         struct generic_pm_domain *genpd;
1190
1191         dev_dbg(dev, "%s()\n", __func__);
1192
1193         genpd = dev_to_genpd(dev);
1194         if (IS_ERR(genpd))
1195                 return -EINVAL;
1196
1197         return genpd->suspend_power_off ? 0 : genpd_start_dev(genpd, dev);
1198 }
1199
1200 /**
1201  * pm_genpd_thaw_early - Early thaw of device in an I/O PM domain.
1202  * @dev: Device to thaw.
1203  *
1204  * Carry out an early thaw of a device under the assumption that its
1205  * pm_domain field points to the domain member of an object of type
1206  * struct generic_pm_domain representing a power domain consisting of I/O
1207  * devices.
1208  */
1209 static int pm_genpd_thaw_early(struct device *dev)
1210 {
1211         struct generic_pm_domain *genpd;
1212
1213         dev_dbg(dev, "%s()\n", __func__);
1214
1215         genpd = dev_to_genpd(dev);
1216         if (IS_ERR(genpd))
1217                 return -EINVAL;
1218
1219         return genpd->suspend_power_off ? 0 : pm_generic_thaw_early(dev);
1220 }
1221
1222 /**
1223  * pm_genpd_thaw - Thaw a device belonging to an I/O power domain.
1224  * @dev: Device to thaw.
1225  *
1226  * Thaw a device under the assumption that its pm_domain field points to the
1227  * domain member of an object of type struct generic_pm_domain representing
1228  * a power domain consisting of I/O devices.
1229  */
1230 static int pm_genpd_thaw(struct device *dev)
1231 {
1232         struct generic_pm_domain *genpd;
1233
1234         dev_dbg(dev, "%s()\n", __func__);
1235
1236         genpd = dev_to_genpd(dev);
1237         if (IS_ERR(genpd))
1238                 return -EINVAL;
1239
1240         return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev);
1241 }
1242
1243 /**
1244  * pm_genpd_restore_noirq - Start of restore of device in an I/O PM domain.
1245  * @dev: Device to resume.
1246  *
1247  * Make sure the domain will be in the same power state as before the
1248  * hibernation the system is resuming from and start the device if necessary.
1249  */
1250 static int pm_genpd_restore_noirq(struct device *dev)
1251 {
1252         struct generic_pm_domain *genpd;
1253
1254         dev_dbg(dev, "%s()\n", __func__);
1255
1256         genpd = dev_to_genpd(dev);
1257         if (IS_ERR(genpd))
1258                 return -EINVAL;
1259
1260         /*
1261          * Since all of the "noirq" callbacks are executed sequentially, it is
1262          * guaranteed that this function will never run twice in parallel for
1263          * the same PM domain, so it is not necessary to use locking here.
1264          *
1265          * At this point suspended_count == 0 means we are being run for the
1266          * first time for the given domain in the present cycle.
1267          */
1268         if (genpd->suspended_count++ == 0) {
1269                 /*
1270                  * The boot kernel might put the domain into arbitrary state,
1271                  * so make it appear as powered off to pm_genpd_sync_poweron(),
1272                  * so that it tries to power it on in case it was really off.
1273                  */
1274                 genpd->status = GPD_STATE_POWER_OFF;
1275                 if (genpd->suspend_power_off) {
1276                         /*
1277                          * If the domain was off before the hibernation, make
1278                          * sure it will be off going forward.
1279                          */
1280                         if (genpd->power_off)
1281                                 genpd->power_off(genpd);
1282
1283                         return 0;
1284                 }
1285         }
1286
1287         if (genpd->suspend_power_off)
1288                 return 0;
1289
1290         pm_genpd_sync_poweron(genpd);
1291
1292         return genpd_start_dev(genpd, dev);
1293 }
1294
1295 /**
1296  * pm_genpd_complete - Complete power transition of a device in a power domain.
1297  * @dev: Device to complete the transition of.
1298  *
1299  * Complete a power transition of a device (during a system-wide power
1300  * transition) under the assumption that its pm_domain field points to the
1301  * domain member of an object of type struct generic_pm_domain representing
1302  * a power domain consisting of I/O devices.
1303  */
1304 static void pm_genpd_complete(struct device *dev)
1305 {
1306         struct generic_pm_domain *genpd;
1307         bool run_complete;
1308
1309         dev_dbg(dev, "%s()\n", __func__);
1310
1311         genpd = dev_to_genpd(dev);
1312         if (IS_ERR(genpd))
1313                 return;
1314
1315         mutex_lock(&genpd->lock);
1316
1317         run_complete = !genpd->suspend_power_off;
1318         if (--genpd->prepared_count == 0)
1319                 genpd->suspend_power_off = false;
1320
1321         mutex_unlock(&genpd->lock);
1322
1323         if (run_complete) {
1324                 pm_generic_complete(dev);
1325                 pm_runtime_set_active(dev);
1326                 pm_runtime_enable(dev);
1327                 pm_request_idle(dev);
1328         }
1329 }
1330
1331 /**
1332  * genpd_syscore_switch - Switch power during system core suspend or resume.
1333  * @dev: Device that normally is marked as "always on" to switch power for.
1334  *
1335  * This routine may only be called during the system core (syscore) suspend or
1336  * resume phase for devices whose "always on" flags are set.
1337  */
1338 static void genpd_syscore_switch(struct device *dev, bool suspend)
1339 {
1340         struct generic_pm_domain *genpd;
1341
1342         genpd = dev_to_genpd(dev);
1343         if (!pm_genpd_present(genpd))
1344                 return;
1345
1346         if (suspend) {
1347                 genpd->suspended_count++;
1348                 pm_genpd_sync_poweroff(genpd);
1349         } else {
1350                 pm_genpd_sync_poweron(genpd);
1351                 genpd->suspended_count--;
1352         }
1353 }
1354
1355 void pm_genpd_syscore_poweroff(struct device *dev)
1356 {
1357         genpd_syscore_switch(dev, true);
1358 }
1359 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweroff);
1360
1361 void pm_genpd_syscore_poweron(struct device *dev)
1362 {
1363         genpd_syscore_switch(dev, false);
1364 }
1365 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron);
1366
1367 #else
1368
1369 #define pm_genpd_prepare                NULL
1370 #define pm_genpd_suspend                NULL
1371 #define pm_genpd_suspend_late           NULL
1372 #define pm_genpd_suspend_noirq          NULL
1373 #define pm_genpd_resume_early           NULL
1374 #define pm_genpd_resume_noirq           NULL
1375 #define pm_genpd_resume                 NULL
1376 #define pm_genpd_freeze                 NULL
1377 #define pm_genpd_freeze_late            NULL
1378 #define pm_genpd_freeze_noirq           NULL
1379 #define pm_genpd_thaw_early             NULL
1380 #define pm_genpd_thaw_noirq             NULL
1381 #define pm_genpd_thaw                   NULL
1382 #define pm_genpd_restore_noirq          NULL
1383 #define pm_genpd_complete               NULL
1384
1385 #endif /* CONFIG_PM_SLEEP */
1386
1387 static struct generic_pm_domain_data *__pm_genpd_alloc_dev_data(struct device *dev)
1388 {
1389         struct generic_pm_domain_data *gpd_data;
1390
1391         gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
1392         if (!gpd_data)
1393                 return NULL;
1394
1395         mutex_init(&gpd_data->lock);
1396         gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
1397         dev_pm_qos_add_notifier(dev, &gpd_data->nb);
1398         return gpd_data;
1399 }
1400
1401 static void __pm_genpd_free_dev_data(struct device *dev,
1402                                      struct generic_pm_domain_data *gpd_data)
1403 {
1404         dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
1405         kfree(gpd_data);
1406 }
1407
1408 /**
1409  * __pm_genpd_add_device - Add a device to an I/O PM domain.
1410  * @genpd: PM domain to add the device to.
1411  * @dev: Device to be added.
1412  * @td: Set of PM QoS timing parameters to attach to the device.
1413  */
1414 int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
1415                           struct gpd_timing_data *td)
1416 {
1417         struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL;
1418         struct pm_domain_data *pdd;
1419         int ret = 0;
1420
1421         dev_dbg(dev, "%s()\n", __func__);
1422
1423         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
1424                 return -EINVAL;
1425
1426         gpd_data_new = __pm_genpd_alloc_dev_data(dev);
1427         if (!gpd_data_new)
1428                 return -ENOMEM;
1429
1430         genpd_acquire_lock(genpd);
1431
1432         if (genpd->prepared_count > 0) {
1433                 ret = -EAGAIN;
1434                 goto out;
1435         }
1436
1437         list_for_each_entry(pdd, &genpd->dev_list, list_node)
1438                 if (pdd->dev == dev) {
1439                         ret = -EINVAL;
1440                         goto out;
1441                 }
1442
1443         ret = dev_pm_get_subsys_data(dev);
1444         if (ret)
1445                 goto out;
1446
1447         genpd->device_count++;
1448         genpd->max_off_time_changed = true;
1449
1450         spin_lock_irq(&dev->power.lock);
1451
1452         dev->pm_domain = &genpd->domain;
1453         if (dev->power.subsys_data->domain_data) {
1454                 gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
1455         } else {
1456                 gpd_data = gpd_data_new;
1457                 dev->power.subsys_data->domain_data = &gpd_data->base;
1458         }
1459         gpd_data->refcount++;
1460         if (td)
1461                 gpd_data->td = *td;
1462
1463         spin_unlock_irq(&dev->power.lock);
1464
1465         if (genpd->attach_dev)
1466                 genpd->attach_dev(genpd, dev);
1467
1468         mutex_lock(&gpd_data->lock);
1469         gpd_data->base.dev = dev;
1470         list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
1471         gpd_data->need_restore = -1;
1472         gpd_data->td.constraint_changed = true;
1473         gpd_data->td.effective_constraint_ns = -1;
1474         mutex_unlock(&gpd_data->lock);
1475
1476  out:
1477         genpd_release_lock(genpd);
1478
1479         if (gpd_data != gpd_data_new)
1480                 __pm_genpd_free_dev_data(dev, gpd_data_new);
1481
1482         return ret;
1483 }
1484
1485 /**
1486  * __pm_genpd_name_add_device - Find I/O PM domain and add a device to it.
1487  * @domain_name: Name of the PM domain to add the device to.
1488  * @dev: Device to be added.
1489  * @td: Set of PM QoS timing parameters to attach to the device.
1490  */
1491 int __pm_genpd_name_add_device(const char *domain_name, struct device *dev,
1492                                struct gpd_timing_data *td)
1493 {
1494         return __pm_genpd_add_device(pm_genpd_lookup_name(domain_name), dev, td);
1495 }
1496
1497 /**
1498  * pm_genpd_remove_device - Remove a device from an I/O PM domain.
1499  * @genpd: PM domain to remove the device from.
1500  * @dev: Device to be removed.
1501  */
1502 int pm_genpd_remove_device(struct generic_pm_domain *genpd,
1503                            struct device *dev)
1504 {
1505         struct generic_pm_domain_data *gpd_data;
1506         struct pm_domain_data *pdd;
1507         bool remove = false;
1508         int ret = 0;
1509
1510         dev_dbg(dev, "%s()\n", __func__);
1511
1512         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)
1513             ||  IS_ERR_OR_NULL(dev->pm_domain)
1514             ||  pd_to_genpd(dev->pm_domain) != genpd)
1515                 return -EINVAL;
1516
1517         genpd_acquire_lock(genpd);
1518
1519         if (genpd->prepared_count > 0) {
1520                 ret = -EAGAIN;
1521                 goto out;
1522         }
1523
1524         genpd->device_count--;
1525         genpd->max_off_time_changed = true;
1526
1527         if (genpd->detach_dev)
1528                 genpd->detach_dev(genpd, dev);
1529
1530         spin_lock_irq(&dev->power.lock);
1531
1532         dev->pm_domain = NULL;
1533         pdd = dev->power.subsys_data->domain_data;
1534         list_del_init(&pdd->list_node);
1535         gpd_data = to_gpd_data(pdd);
1536         if (--gpd_data->refcount == 0) {
1537                 dev->power.subsys_data->domain_data = NULL;
1538                 remove = true;
1539         }
1540
1541         spin_unlock_irq(&dev->power.lock);
1542
1543         mutex_lock(&gpd_data->lock);
1544         pdd->dev = NULL;
1545         mutex_unlock(&gpd_data->lock);
1546
1547         genpd_release_lock(genpd);
1548
1549         dev_pm_put_subsys_data(dev);
1550         if (remove)
1551                 __pm_genpd_free_dev_data(dev, gpd_data);
1552
1553         return 0;
1554
1555  out:
1556         genpd_release_lock(genpd);
1557
1558         return ret;
1559 }
1560
1561 /**
1562  * pm_genpd_dev_need_restore - Set/unset the device's "need restore" flag.
1563  * @dev: Device to set/unset the flag for.
1564  * @val: The new value of the device's "need restore" flag.
1565  */
1566 void pm_genpd_dev_need_restore(struct device *dev, bool val)
1567 {
1568         struct pm_subsys_data *psd;
1569         unsigned long flags;
1570
1571         spin_lock_irqsave(&dev->power.lock, flags);
1572
1573         psd = dev_to_psd(dev);
1574         if (psd && psd->domain_data)
1575                 to_gpd_data(psd->domain_data)->need_restore = val ? 1 : 0;
1576
1577         spin_unlock_irqrestore(&dev->power.lock, flags);
1578 }
1579 EXPORT_SYMBOL_GPL(pm_genpd_dev_need_restore);
1580
1581 /**
1582  * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
1583  * @genpd: Master PM domain to add the subdomain to.
1584  * @subdomain: Subdomain to be added.
1585  */
1586 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
1587                            struct generic_pm_domain *subdomain)
1588 {
1589         struct gpd_link *link;
1590         int ret = 0;
1591
1592         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
1593             || genpd == subdomain)
1594                 return -EINVAL;
1595
1596  start:
1597         genpd_acquire_lock(genpd);
1598         mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1599
1600         if (subdomain->status != GPD_STATE_POWER_OFF
1601             && subdomain->status != GPD_STATE_ACTIVE) {
1602                 mutex_unlock(&subdomain->lock);
1603                 genpd_release_lock(genpd);
1604                 goto start;
1605         }
1606
1607         if (genpd->status == GPD_STATE_POWER_OFF
1608             &&  subdomain->status != GPD_STATE_POWER_OFF) {
1609                 ret = -EINVAL;
1610                 goto out;
1611         }
1612
1613         list_for_each_entry(link, &genpd->master_links, master_node) {
1614                 if (link->slave == subdomain && link->master == genpd) {
1615                         ret = -EINVAL;
1616                         goto out;
1617                 }
1618         }
1619
1620         link = kzalloc(sizeof(*link), GFP_KERNEL);
1621         if (!link) {
1622                 ret = -ENOMEM;
1623                 goto out;
1624         }
1625         link->master = genpd;
1626         list_add_tail(&link->master_node, &genpd->master_links);
1627         link->slave = subdomain;
1628         list_add_tail(&link->slave_node, &subdomain->slave_links);
1629         if (subdomain->status != GPD_STATE_POWER_OFF)
1630                 genpd_sd_counter_inc(genpd);
1631
1632  out:
1633         mutex_unlock(&subdomain->lock);
1634         genpd_release_lock(genpd);
1635
1636         return ret;
1637 }
1638
1639 /**
1640  * pm_genpd_add_subdomain_names - Add a subdomain to an I/O PM domain.
1641  * @master_name: Name of the master PM domain to add the subdomain to.
1642  * @subdomain_name: Name of the subdomain to be added.
1643  */
1644 int pm_genpd_add_subdomain_names(const char *master_name,
1645                                  const char *subdomain_name)
1646 {
1647         struct generic_pm_domain *master = NULL, *subdomain = NULL, *gpd;
1648
1649         if (IS_ERR_OR_NULL(master_name) || IS_ERR_OR_NULL(subdomain_name))
1650                 return -EINVAL;
1651
1652         mutex_lock(&gpd_list_lock);
1653         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
1654                 if (!master && !strcmp(gpd->name, master_name))
1655                         master = gpd;
1656
1657                 if (!subdomain && !strcmp(gpd->name, subdomain_name))
1658                         subdomain = gpd;
1659
1660                 if (master && subdomain)
1661                         break;
1662         }
1663         mutex_unlock(&gpd_list_lock);
1664
1665         return pm_genpd_add_subdomain(master, subdomain);
1666 }
1667
1668 /**
1669  * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
1670  * @genpd: Master PM domain to remove the subdomain from.
1671  * @subdomain: Subdomain to be removed.
1672  */
1673 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
1674                               struct generic_pm_domain *subdomain)
1675 {
1676         struct gpd_link *link;
1677         int ret = -EINVAL;
1678
1679         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
1680                 return -EINVAL;
1681
1682  start:
1683         genpd_acquire_lock(genpd);
1684
1685         list_for_each_entry(link, &genpd->master_links, master_node) {
1686                 if (link->slave != subdomain)
1687                         continue;
1688
1689                 mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1690
1691                 if (subdomain->status != GPD_STATE_POWER_OFF
1692                     && subdomain->status != GPD_STATE_ACTIVE) {
1693                         mutex_unlock(&subdomain->lock);
1694                         genpd_release_lock(genpd);
1695                         goto start;
1696                 }
1697
1698                 list_del(&link->master_node);
1699                 list_del(&link->slave_node);
1700                 kfree(link);
1701                 if (subdomain->status != GPD_STATE_POWER_OFF)
1702                         genpd_sd_counter_dec(genpd);
1703
1704                 mutex_unlock(&subdomain->lock);
1705
1706                 ret = 0;
1707                 break;
1708         }
1709
1710         genpd_release_lock(genpd);
1711
1712         return ret;
1713 }
1714
1715 /**
1716  * pm_genpd_attach_cpuidle - Connect the given PM domain with cpuidle.
1717  * @genpd: PM domain to be connected with cpuidle.
1718  * @state: cpuidle state this domain can disable/enable.
1719  *
1720  * Make a PM domain behave as though it contained a CPU core, that is, instead
1721  * of calling its power down routine it will enable the given cpuidle state so
1722  * that the cpuidle subsystem can power it down (if possible and desirable).
1723  */
1724 int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
1725 {
1726         struct cpuidle_driver *cpuidle_drv;
1727         struct gpd_cpuidle_data *cpuidle_data;
1728         struct cpuidle_state *idle_state;
1729         int ret = 0;
1730
1731         if (IS_ERR_OR_NULL(genpd) || state < 0)
1732                 return -EINVAL;
1733
1734         genpd_acquire_lock(genpd);
1735
1736         if (genpd->cpuidle_data) {
1737                 ret = -EEXIST;
1738                 goto out;
1739         }
1740         cpuidle_data = kzalloc(sizeof(*cpuidle_data), GFP_KERNEL);
1741         if (!cpuidle_data) {
1742                 ret = -ENOMEM;
1743                 goto out;
1744         }
1745         cpuidle_drv = cpuidle_driver_ref();
1746         if (!cpuidle_drv) {
1747                 ret = -ENODEV;
1748                 goto err_drv;
1749         }
1750         if (cpuidle_drv->state_count <= state) {
1751                 ret = -EINVAL;
1752                 goto err;
1753         }
1754         idle_state = &cpuidle_drv->states[state];
1755         if (!idle_state->disabled) {
1756                 ret = -EAGAIN;
1757                 goto err;
1758         }
1759         cpuidle_data->idle_state = idle_state;
1760         cpuidle_data->saved_exit_latency = idle_state->exit_latency;
1761         genpd->cpuidle_data = cpuidle_data;
1762         genpd_recalc_cpu_exit_latency(genpd);
1763
1764  out:
1765         genpd_release_lock(genpd);
1766         return ret;
1767
1768  err:
1769         cpuidle_driver_unref();
1770
1771  err_drv:
1772         kfree(cpuidle_data);
1773         goto out;
1774 }
1775
1776 /**
1777  * pm_genpd_name_attach_cpuidle - Find PM domain and connect cpuidle to it.
1778  * @name: Name of the domain to connect to cpuidle.
1779  * @state: cpuidle state this domain can manipulate.
1780  */
1781 int pm_genpd_name_attach_cpuidle(const char *name, int state)
1782 {
1783         return pm_genpd_attach_cpuidle(pm_genpd_lookup_name(name), state);
1784 }
1785
1786 /**
1787  * pm_genpd_detach_cpuidle - Remove the cpuidle connection from a PM domain.
1788  * @genpd: PM domain to remove the cpuidle connection from.
1789  *
1790  * Remove the cpuidle connection set up by pm_genpd_attach_cpuidle() from the
1791  * given PM domain.
1792  */
1793 int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd)
1794 {
1795         struct gpd_cpuidle_data *cpuidle_data;
1796         struct cpuidle_state *idle_state;
1797         int ret = 0;
1798
1799         if (IS_ERR_OR_NULL(genpd))
1800                 return -EINVAL;
1801
1802         genpd_acquire_lock(genpd);
1803
1804         cpuidle_data = genpd->cpuidle_data;
1805         if (!cpuidle_data) {
1806                 ret = -ENODEV;
1807                 goto out;
1808         }
1809         idle_state = cpuidle_data->idle_state;
1810         if (!idle_state->disabled) {
1811                 ret = -EAGAIN;
1812                 goto out;
1813         }
1814         idle_state->exit_latency = cpuidle_data->saved_exit_latency;
1815         cpuidle_driver_unref();
1816         genpd->cpuidle_data = NULL;
1817         kfree(cpuidle_data);
1818
1819  out:
1820         genpd_release_lock(genpd);
1821         return ret;
1822 }
1823
1824 /**
1825  * pm_genpd_name_detach_cpuidle - Find PM domain and disconnect cpuidle from it.
1826  * @name: Name of the domain to disconnect cpuidle from.
1827  */
1828 int pm_genpd_name_detach_cpuidle(const char *name)
1829 {
1830         return pm_genpd_detach_cpuidle(pm_genpd_lookup_name(name));
1831 }
1832
1833 /* Default device callbacks for generic PM domains. */
1834
1835 /**
1836  * pm_genpd_default_save_state - Default "save device state" for PM domains.
1837  * @dev: Device to handle.
1838  */
1839 static int pm_genpd_default_save_state(struct device *dev)
1840 {
1841         int (*cb)(struct device *__dev);
1842
1843         if (dev->type && dev->type->pm)
1844                 cb = dev->type->pm->runtime_suspend;
1845         else if (dev->class && dev->class->pm)
1846                 cb = dev->class->pm->runtime_suspend;
1847         else if (dev->bus && dev->bus->pm)
1848                 cb = dev->bus->pm->runtime_suspend;
1849         else
1850                 cb = NULL;
1851
1852         if (!cb && dev->driver && dev->driver->pm)
1853                 cb = dev->driver->pm->runtime_suspend;
1854
1855         return cb ? cb(dev) : 0;
1856 }
1857
1858 /**
1859  * pm_genpd_default_restore_state - Default PM domains "restore device state".
1860  * @dev: Device to handle.
1861  */
1862 static int pm_genpd_default_restore_state(struct device *dev)
1863 {
1864         int (*cb)(struct device *__dev);
1865
1866         if (dev->type && dev->type->pm)
1867                 cb = dev->type->pm->runtime_resume;
1868         else if (dev->class && dev->class->pm)
1869                 cb = dev->class->pm->runtime_resume;
1870         else if (dev->bus && dev->bus->pm)
1871                 cb = dev->bus->pm->runtime_resume;
1872         else
1873                 cb = NULL;
1874
1875         if (!cb && dev->driver && dev->driver->pm)
1876                 cb = dev->driver->pm->runtime_resume;
1877
1878         return cb ? cb(dev) : 0;
1879 }
1880
1881 /**
1882  * pm_genpd_init - Initialize a generic I/O PM domain object.
1883  * @genpd: PM domain object to initialize.
1884  * @gov: PM domain governor to associate with the domain (may be NULL).
1885  * @is_off: Initial value of the domain's power_is_off field.
1886  */
1887 void pm_genpd_init(struct generic_pm_domain *genpd,
1888                    struct dev_power_governor *gov, bool is_off)
1889 {
1890         if (IS_ERR_OR_NULL(genpd))
1891                 return;
1892
1893         INIT_LIST_HEAD(&genpd->master_links);
1894         INIT_LIST_HEAD(&genpd->slave_links);
1895         INIT_LIST_HEAD(&genpd->dev_list);
1896         mutex_init(&genpd->lock);
1897         genpd->gov = gov;
1898         INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
1899         genpd->in_progress = 0;
1900         atomic_set(&genpd->sd_count, 0);
1901         genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
1902         init_waitqueue_head(&genpd->status_wait_queue);
1903         genpd->poweroff_task = NULL;
1904         genpd->resume_count = 0;
1905         genpd->device_count = 0;
1906         genpd->max_off_time_ns = -1;
1907         genpd->max_off_time_changed = true;
1908         genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
1909         genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
1910         genpd->domain.ops.prepare = pm_genpd_prepare;
1911         genpd->domain.ops.suspend = pm_genpd_suspend;
1912         genpd->domain.ops.suspend_late = pm_genpd_suspend_late;
1913         genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq;
1914         genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq;
1915         genpd->domain.ops.resume_early = pm_genpd_resume_early;
1916         genpd->domain.ops.resume = pm_genpd_resume;
1917         genpd->domain.ops.freeze = pm_genpd_freeze;
1918         genpd->domain.ops.freeze_late = pm_genpd_freeze_late;
1919         genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq;
1920         genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq;
1921         genpd->domain.ops.thaw_early = pm_genpd_thaw_early;
1922         genpd->domain.ops.thaw = pm_genpd_thaw;
1923         genpd->domain.ops.poweroff = pm_genpd_suspend;
1924         genpd->domain.ops.poweroff_late = pm_genpd_suspend_late;
1925         genpd->domain.ops.poweroff_noirq = pm_genpd_suspend_noirq;
1926         genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
1927         genpd->domain.ops.restore_early = pm_genpd_resume_early;
1928         genpd->domain.ops.restore = pm_genpd_resume;
1929         genpd->domain.ops.complete = pm_genpd_complete;
1930         genpd->dev_ops.save_state = pm_genpd_default_save_state;
1931         genpd->dev_ops.restore_state = pm_genpd_default_restore_state;
1932         mutex_lock(&gpd_list_lock);
1933         list_add(&genpd->gpd_list_node, &gpd_list);
1934         mutex_unlock(&gpd_list_lock);
1935 }
1936
1937 #ifdef CONFIG_PM_GENERIC_DOMAINS_OF
1938 /*
1939  * Device Tree based PM domain providers.
1940  *
1941  * The code below implements generic device tree based PM domain providers that
1942  * bind device tree nodes with generic PM domains registered in the system.
1943  *
1944  * Any driver that registers generic PM domains and needs to support binding of
1945  * devices to these domains is supposed to register a PM domain provider, which
1946  * maps a PM domain specifier retrieved from the device tree to a PM domain.
1947  *
1948  * Two simple mapping functions have been provided for convenience:
1949  *  - __of_genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
1950  *  - __of_genpd_xlate_onecell() for mapping of multiple PM domains per node by
1951  *    index.
1952  */
1953
1954 /**
1955  * struct of_genpd_provider - PM domain provider registration structure
1956  * @link: Entry in global list of PM domain providers
1957  * @node: Pointer to device tree node of PM domain provider
1958  * @xlate: Provider-specific xlate callback mapping a set of specifier cells
1959  *         into a PM domain.
1960  * @data: context pointer to be passed into @xlate callback
1961  */
1962 struct of_genpd_provider {
1963         struct list_head link;
1964         struct device_node *node;
1965         genpd_xlate_t xlate;
1966         void *data;
1967 };
1968
1969 /* List of registered PM domain providers. */
1970 static LIST_HEAD(of_genpd_providers);
1971 /* Mutex to protect the list above. */
1972 static DEFINE_MUTEX(of_genpd_mutex);
1973
1974 /**
1975  * __of_genpd_xlate_simple() - Xlate function for direct node-domain mapping
1976  * @genpdspec: OF phandle args to map into a PM domain
1977  * @data: xlate function private data - pointer to struct generic_pm_domain
1978  *
1979  * This is a generic xlate function that can be used to model PM domains that
1980  * have their own device tree nodes. The private data of xlate function needs
1981  * to be a valid pointer to struct generic_pm_domain.
1982  */
1983 struct generic_pm_domain *__of_genpd_xlate_simple(
1984                                         struct of_phandle_args *genpdspec,
1985                                         void *data)
1986 {
1987         if (genpdspec->args_count != 0)
1988                 return ERR_PTR(-EINVAL);
1989         return data;
1990 }
1991 EXPORT_SYMBOL_GPL(__of_genpd_xlate_simple);
1992
1993 /**
1994  * __of_genpd_xlate_onecell() - Xlate function using a single index.
1995  * @genpdspec: OF phandle args to map into a PM domain
1996  * @data: xlate function private data - pointer to struct genpd_onecell_data
1997  *
1998  * This is a generic xlate function that can be used to model simple PM domain
1999  * controllers that have one device tree node and provide multiple PM domains.
2000  * A single cell is used as an index into an array of PM domains specified in
2001  * the genpd_onecell_data struct when registering the provider.
2002  */
2003 struct generic_pm_domain *__of_genpd_xlate_onecell(
2004                                         struct of_phandle_args *genpdspec,
2005                                         void *data)
2006 {
2007         struct genpd_onecell_data *genpd_data = data;
2008         unsigned int idx = genpdspec->args[0];
2009
2010         if (genpdspec->args_count != 1)
2011                 return ERR_PTR(-EINVAL);
2012
2013         if (idx >= genpd_data->num_domains) {
2014                 pr_err("%s: invalid domain index %u\n", __func__, idx);
2015                 return ERR_PTR(-EINVAL);
2016         }
2017
2018         if (!genpd_data->domains[idx])
2019                 return ERR_PTR(-ENOENT);
2020
2021         return genpd_data->domains[idx];
2022 }
2023 EXPORT_SYMBOL_GPL(__of_genpd_xlate_onecell);
2024
2025 /**
2026  * __of_genpd_add_provider() - Register a PM domain provider for a node
2027  * @np: Device node pointer associated with the PM domain provider.
2028  * @xlate: Callback for decoding PM domain from phandle arguments.
2029  * @data: Context pointer for @xlate callback.
2030  */
2031 int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
2032                         void *data)
2033 {
2034         struct of_genpd_provider *cp;
2035
2036         cp = kzalloc(sizeof(*cp), GFP_KERNEL);
2037         if (!cp)
2038                 return -ENOMEM;
2039
2040         cp->node = of_node_get(np);
2041         cp->data = data;
2042         cp->xlate = xlate;
2043
2044         mutex_lock(&of_genpd_mutex);
2045         list_add(&cp->link, &of_genpd_providers);
2046         mutex_unlock(&of_genpd_mutex);
2047         pr_debug("Added domain provider from %s\n", np->full_name);
2048
2049         return 0;
2050 }
2051 EXPORT_SYMBOL_GPL(__of_genpd_add_provider);
2052
2053 /**
2054  * of_genpd_del_provider() - Remove a previously registered PM domain provider
2055  * @np: Device node pointer associated with the PM domain provider
2056  */
2057 void of_genpd_del_provider(struct device_node *np)
2058 {
2059         struct of_genpd_provider *cp;
2060
2061         mutex_lock(&of_genpd_mutex);
2062         list_for_each_entry(cp, &of_genpd_providers, link) {
2063                 if (cp->node == np) {
2064                         list_del(&cp->link);
2065                         of_node_put(cp->node);
2066                         kfree(cp);
2067                         break;
2068                 }
2069         }
2070         mutex_unlock(&of_genpd_mutex);
2071 }
2072 EXPORT_SYMBOL_GPL(of_genpd_del_provider);
2073
2074 /**
2075  * of_genpd_get_from_provider() - Look-up PM domain
2076  * @genpdspec: OF phandle args to use for look-up
2077  *
2078  * Looks for a PM domain provider under the node specified by @genpdspec and if
2079  * found, uses xlate function of the provider to map phandle args to a PM
2080  * domain.
2081  *
2082  * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
2083  * on failure.
2084  */
2085 static struct generic_pm_domain *of_genpd_get_from_provider(
2086                                         struct of_phandle_args *genpdspec)
2087 {
2088         struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
2089         struct of_genpd_provider *provider;
2090
2091         mutex_lock(&of_genpd_mutex);
2092
2093         /* Check if we have such a provider in our array */
2094         list_for_each_entry(provider, &of_genpd_providers, link) {
2095                 if (provider->node == genpdspec->np)
2096                         genpd = provider->xlate(genpdspec, provider->data);
2097                 if (!IS_ERR(genpd))
2098                         break;
2099         }
2100
2101         mutex_unlock(&of_genpd_mutex);
2102
2103         return genpd;
2104 }
2105
2106 /**
2107  * genpd_dev_pm_detach - Detach a device from its PM domain.
2108  * @dev: Device to attach.
2109  * @power_off: Currently not used
2110  *
2111  * Try to locate a corresponding generic PM domain, which the device was
2112  * attached to previously. If such is found, the device is detached from it.
2113  */
2114 static void genpd_dev_pm_detach(struct device *dev, bool power_off)
2115 {
2116         struct generic_pm_domain *pd = NULL, *gpd;
2117         int ret = 0;
2118
2119         if (!dev->pm_domain)
2120                 return;
2121
2122         mutex_lock(&gpd_list_lock);
2123         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
2124                 if (&gpd->domain == dev->pm_domain) {
2125                         pd = gpd;
2126                         break;
2127                 }
2128         }
2129         mutex_unlock(&gpd_list_lock);
2130
2131         if (!pd)
2132                 return;
2133
2134         dev_dbg(dev, "removing from PM domain %s\n", pd->name);
2135
2136         while (1) {
2137                 ret = pm_genpd_remove_device(pd, dev);
2138                 if (ret != -EAGAIN)
2139                         break;
2140                 cond_resched();
2141         }
2142
2143         if (ret < 0) {
2144                 dev_err(dev, "failed to remove from PM domain %s: %d",
2145                         pd->name, ret);
2146                 return;
2147         }
2148
2149         /* Check if PM domain can be powered off after removing this device. */
2150         genpd_queue_power_off_work(pd);
2151 }
2152
2153 /**
2154  * genpd_dev_pm_attach - Attach a device to its PM domain using DT.
2155  * @dev: Device to attach.
2156  *
2157  * Parse device's OF node to find a PM domain specifier. If such is found,
2158  * attaches the device to retrieved pm_domain ops.
2159  *
2160  * Both generic and legacy Samsung-specific DT bindings are supported to keep
2161  * backwards compatibility with existing DTBs.
2162  *
2163  * Returns 0 on successfully attached PM domain or negative error code.
2164  */
2165 int genpd_dev_pm_attach(struct device *dev)
2166 {
2167         struct of_phandle_args pd_args;
2168         struct generic_pm_domain *pd;
2169         int ret;
2170
2171         if (!dev->of_node)
2172                 return -ENODEV;
2173
2174         if (dev->pm_domain)
2175                 return -EEXIST;
2176
2177         ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
2178                                         "#power-domain-cells", 0, &pd_args);
2179         if (ret < 0) {
2180                 if (ret != -ENOENT)
2181                         return ret;
2182
2183                 /*
2184                  * Try legacy Samsung-specific bindings
2185                  * (for backwards compatibility of DT ABI)
2186                  */
2187                 pd_args.args_count = 0;
2188                 pd_args.np = of_parse_phandle(dev->of_node,
2189                                                 "samsung,power-domain", 0);
2190                 if (!pd_args.np)
2191                         return -ENOENT;
2192         }
2193
2194         pd = of_genpd_get_from_provider(&pd_args);
2195         if (IS_ERR(pd)) {
2196                 dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
2197                         __func__, PTR_ERR(pd));
2198                 of_node_put(dev->of_node);
2199                 return PTR_ERR(pd);
2200         }
2201
2202         dev_dbg(dev, "adding to PM domain %s\n", pd->name);
2203
2204         while (1) {
2205                 ret = pm_genpd_add_device(pd, dev);
2206                 if (ret != -EAGAIN)
2207                         break;
2208                 cond_resched();
2209         }
2210
2211         if (ret < 0) {
2212                 dev_err(dev, "failed to add to PM domain %s: %d",
2213                         pd->name, ret);
2214                 of_node_put(dev->of_node);
2215                 return ret;
2216         }
2217
2218         dev->pm_domain->detach = genpd_dev_pm_detach;
2219
2220         return 0;
2221 }
2222 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
2223 #endif
2224
2225
2226 /***        debugfs support        ***/
2227
2228 #ifdef CONFIG_PM_ADVANCED_DEBUG
2229 #include <linux/pm.h>
2230 #include <linux/device.h>
2231 #include <linux/debugfs.h>
2232 #include <linux/seq_file.h>
2233 #include <linux/init.h>
2234 #include <linux/kobject.h>
2235 static struct dentry *pm_genpd_debugfs_dir;
2236
2237 /*
2238  * TODO: This function is a slightly modified version of rtpm_status_show
2239  * from sysfs.c, but dependencies between PM_GENERIC_DOMAINS and PM_RUNTIME
2240  * are too loose to generalize it.
2241  */
2242 #ifdef CONFIG_PM_RUNTIME
2243 static void rtpm_status_str(struct seq_file *s, struct device *dev)
2244 {
2245         static const char * const status_lookup[] = {
2246                 [RPM_ACTIVE] = "active",
2247                 [RPM_RESUMING] = "resuming",
2248                 [RPM_SUSPENDED] = "suspended",
2249                 [RPM_SUSPENDING] = "suspending"
2250         };
2251         const char *p = "";
2252
2253         if (dev->power.runtime_error)
2254                 p = "error";
2255         else if (dev->power.disable_depth)
2256                 p = "unsupported";
2257         else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup))
2258                 p = status_lookup[dev->power.runtime_status];
2259         else
2260                 WARN_ON(1);
2261
2262         seq_puts(s, p);
2263 }
2264 #else
2265 static void rtpm_status_str(struct seq_file *s, struct device *dev)
2266 {
2267         seq_puts(s, "active");
2268 }
2269 #endif
2270
2271 static int pm_genpd_summary_one(struct seq_file *s,
2272                 struct generic_pm_domain *gpd)
2273 {
2274         static const char * const status_lookup[] = {
2275                 [GPD_STATE_ACTIVE] = "on",
2276                 [GPD_STATE_WAIT_MASTER] = "wait-master",
2277                 [GPD_STATE_BUSY] = "busy",
2278                 [GPD_STATE_REPEAT] = "off-in-progress",
2279                 [GPD_STATE_POWER_OFF] = "off"
2280         };
2281         struct pm_domain_data *pm_data;
2282         const char *kobj_path;
2283         struct gpd_link *link;
2284         int ret;
2285
2286         ret = mutex_lock_interruptible(&gpd->lock);
2287         if (ret)
2288                 return -ERESTARTSYS;
2289
2290         if (WARN_ON(gpd->status >= ARRAY_SIZE(status_lookup)))
2291                 goto exit;
2292         seq_printf(s, "%-30s  %-15s  ", gpd->name, status_lookup[gpd->status]);
2293
2294         /*
2295          * Modifications on the list require holding locks on both
2296          * master and slave, so we are safe.
2297          * Also gpd->name is immutable.
2298          */
2299         list_for_each_entry(link, &gpd->master_links, master_node) {
2300                 seq_printf(s, "%s", link->slave->name);
2301                 if (!list_is_last(&link->master_node, &gpd->master_links))
2302                         seq_puts(s, ", ");
2303         }
2304
2305         list_for_each_entry(pm_data, &gpd->dev_list, list_node) {
2306                 kobj_path = kobject_get_path(&pm_data->dev->kobj, GFP_KERNEL);
2307                 if (kobj_path == NULL)
2308                         continue;
2309
2310                 seq_printf(s, "\n    %-50s  ", kobj_path);
2311                 rtpm_status_str(s, pm_data->dev);
2312                 kfree(kobj_path);
2313         }
2314
2315         seq_puts(s, "\n");
2316 exit:
2317         mutex_unlock(&gpd->lock);
2318
2319         return 0;
2320 }
2321
2322 static int pm_genpd_summary_show(struct seq_file *s, void *data)
2323 {
2324         struct generic_pm_domain *gpd;
2325         int ret = 0;
2326
2327         seq_puts(s, "    domain                      status         slaves\n");
2328         seq_puts(s, "           /device                                      runtime status\n");
2329         seq_puts(s, "----------------------------------------------------------------------\n");
2330
2331         ret = mutex_lock_interruptible(&gpd_list_lock);
2332         if (ret)
2333                 return -ERESTARTSYS;
2334
2335         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
2336                 ret = pm_genpd_summary_one(s, gpd);
2337                 if (ret)
2338                         break;
2339         }
2340         mutex_unlock(&gpd_list_lock);
2341
2342         return ret;
2343 }
2344
2345 static int pm_genpd_summary_open(struct inode *inode, struct file *file)
2346 {
2347         return single_open(file, pm_genpd_summary_show, NULL);
2348 }
2349
2350 static const struct file_operations pm_genpd_summary_fops = {
2351         .open = pm_genpd_summary_open,
2352         .read = seq_read,
2353         .llseek = seq_lseek,
2354         .release = single_release,
2355 };
2356
2357 static int __init pm_genpd_debug_init(void)
2358 {
2359         struct dentry *d;
2360
2361         pm_genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL);
2362
2363         if (!pm_genpd_debugfs_dir)
2364                 return -ENOMEM;
2365
2366         d = debugfs_create_file("pm_genpd_summary", S_IRUGO,
2367                         pm_genpd_debugfs_dir, NULL, &pm_genpd_summary_fops);
2368         if (!d)
2369                 return -ENOMEM;
2370
2371         return 0;
2372 }
2373 late_initcall(pm_genpd_debug_init);
2374
2375 static void __exit pm_genpd_debug_exit(void)
2376 {
2377         debugfs_remove_recursive(pm_genpd_debugfs_dir);
2378 }
2379 __exitcall(pm_genpd_debug_exit);
2380 #endif /* CONFIG_PM_ADVANCED_DEBUG */