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
 348         mutex_lock(&gpd_data->lock);
 349         dev = gpd_data->base.dev;
 350         if (!dev) {
 351                 mutex_unlock(&gpd_data->lock);
 352                 return NOTIFY_DONE;
 353         }
 354         mutex_unlock(&gpd_data->lock);
 355
 356         for (;;) {
 357                 struct generic_pm_domain *genpd;
 358                 struct pm_domain_data *pdd;
 359
 360                 spin_lock_irq(&dev->power.lock);
 361
 362                 pdd = dev->power.subsys_data ?
 363                                 dev->power.subsys_data->domain_data : NULL;
 364                 if (pdd && pdd->dev) {
 365                         to_gpd_data(pdd)->td.constraint_changed = true;
 366                         genpd = dev_to_genpd(dev);
 367                 } else {
 368                         genpd = ERR_PTR(-ENODATA);
 369                 }
 370
 371                 spin_unlock_irq(&dev->power.lock);
 372
 373                 if (!IS_ERR(genpd)) {
 374                         mutex_lock(&genpd->lock);
 375                         genpd->max_off_time_changed = true;
 376                         mutex_unlock(&genpd->lock);
 377                 }
 378
 379                 dev = dev->parent;
 380                 if (!dev || dev->power.ignore_children)
 381                         break;
 382         }
 383
 384         return NOTIFY_DONE;
 385 }
 386
 387 /**
 388  * __pm_genpd_save_device - Save the pre-suspend state of a device.
 389  * @pdd: Domain data of the device to save the state of.
 390  * @genpd: PM domain the device belongs to.
 391  */
 392 static int __pm_genpd_save_device(struct pm_domain_data *pdd,
 393                                   struct generic_pm_domain *genpd)
 394         __releases(&genpd->lock) __acquires(&genpd->lock)
 395 {
 396         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 397         struct device *dev = pdd->dev;
 398         int ret = 0;
 399
 400         if (gpd_data->need_restore > 0)
 401                 return 0;
 402
 403         /*
 404          * If the value of the need_restore flag is still unknown at this point,
 405          * we trust that pm_genpd_poweroff() has verified that the device is
 406          * already runtime PM suspended.
 407          */
 408         if (gpd_data->need_restore < 0) {
 409                 gpd_data->need_restore = 1;
 410                 return 0;
 411         }
 412
 413         mutex_unlock(&genpd->lock);
 414
 415         genpd_start_dev(genpd, dev);
 416         ret = genpd_save_dev(genpd, dev);
 417         genpd_stop_dev(genpd, dev);
 418
 419         mutex_lock(&genpd->lock);
 420
 421         if (!ret)
 422                 gpd_data->need_restore = 1;
 423
 424         return ret;
 425 }
 426
 427 /**
 428  * __pm_genpd_restore_device - Restore the pre-suspend state of a device.
 429  * @pdd: Domain data of the device to restore the state of.
 430  * @genpd: PM domain the device belongs to.
 431  */
 432 static void __pm_genpd_restore_device(struct pm_domain_data *pdd,
 433                                       struct generic_pm_domain *genpd)
 434         __releases(&genpd->lock) __acquires(&genpd->lock)
 435 {
 436         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 437         struct device *dev = pdd->dev;
 438         int need_restore = gpd_data->need_restore;
 439
 440         gpd_data->need_restore = 0;
 441         mutex_unlock(&genpd->lock);
 442
 443         genpd_start_dev(genpd, dev);
 444
 445         /*
 446          * Call genpd_restore_dev() for recently added devices too (need_restore
 447          * is negative then).
 448          */
 449         if (need_restore)
 450                 genpd_restore_dev(genpd, dev);
 451
 452         mutex_lock(&genpd->lock);
 453 }
 454
 455 /**
 456  * genpd_abort_poweroff - Check if a PM domain power off should be aborted.
 457  * @genpd: PM domain to check.
 458  *
 459  * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during
 460  * a "power off" operation, which means that a "power on" has occured in the
 461  * meantime, or if its resume_count field is different from zero, which means
 462  * that one of its devices has been resumed in the meantime.
 463  */
 464 static bool genpd_abort_poweroff(struct generic_pm_domain *genpd)
 465 {
 466         return genpd->status == GPD_STATE_WAIT_MASTER
 467                 || genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0;
 468 }
 469
 470 /**
 471  * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff().
 472  * @genpd: PM domait to power off.
 473  *
 474  * Queue up the execution of pm_genpd_poweroff() unless it's already been done
 475  * before.
 476  */
 477 static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
 478 {
 479         queue_work(pm_wq, &genpd->power_off_work);
 480 }
 481
 482 /**
 483  * pm_genpd_poweroff - Remove power from a given PM domain.
 484  * @genpd: PM domain to power down.
 485  *
 486  * If all of the @genpd's devices have been suspended and all of its subdomains
 487  * have been powered down, run the runtime suspend callbacks provided by all of
 488  * the @genpd's devices' drivers and remove power from @genpd.
 489  */
 490 static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
 491         __releases(&genpd->lock) __acquires(&genpd->lock)
 492 {
 493         struct pm_domain_data *pdd;
 494         struct gpd_link *link;
 495         unsigned int not_suspended;
 496         int ret = 0;
 497
 498  start:
 499         /*
 500          * Do not try to power off the domain in the following situations:
 501          * (1) The domain is already in the "power off" state.
 502          * (2) The domain is waiting for its master to power up.
 503          * (3) One of the domain's devices is being resumed right now.
 504          * (4) System suspend is in progress.
 505          */
 506         if (genpd->status == GPD_STATE_POWER_OFF
 507             || genpd->status == GPD_STATE_WAIT_MASTER
 508             || genpd->resume_count > 0 || genpd->prepared_count > 0)
 509                 return 0;
 510
 511         if (atomic_read(&genpd->sd_count) > 0)
 512                 return -EBUSY;
 513
 514         not_suspended = 0;
 515         list_for_each_entry(pdd, &genpd->dev_list, list_node) {
 516                 enum pm_qos_flags_status stat;
 517
 518                 stat = dev_pm_qos_flags(pdd->dev,
 519                                         PM_QOS_FLAG_NO_POWER_OFF
 520                                                 | PM_QOS_FLAG_REMOTE_WAKEUP);
 521                 if (stat > PM_QOS_FLAGS_NONE)
 522                         return -EBUSY;
 523
 524                 if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
 525                     || pdd->dev->power.irq_safe))
 526                         not_suspended++;
 527         }
 528
 529         if (not_suspended > genpd->in_progress)
 530                 return -EBUSY;
 531
 532         if (genpd->poweroff_task) {
 533                 /*
 534                  * Another instance of pm_genpd_poweroff() is executing
 535                  * callbacks, so tell it to start over and return.
 536                  */
 537                 genpd->status = GPD_STATE_REPEAT;
 538                 return 0;
 539         }
 540
 541         if (genpd->gov && genpd->gov->power_down_ok) {
 542                 if (!genpd->gov->power_down_ok(&genpd->domain))
 543                         return -EAGAIN;
 544         }
 545
 546         genpd->status = GPD_STATE_BUSY;
 547         genpd->poweroff_task = current;
 548
 549         list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) {
 550                 ret = atomic_read(&genpd->sd_count) == 0 ?
 551                         __pm_genpd_save_device(pdd, genpd) : -EBUSY;
 552
 553                 if (genpd_abort_poweroff(genpd))
 554                         goto out;
 555
 556                 if (ret) {
 557                         genpd_set_active(genpd);
 558                         goto out;
 559                 }
 560
 561                 if (genpd->status == GPD_STATE_REPEAT) {
 562                         genpd->poweroff_task = NULL;
 563                         goto start;
 564                 }
 565         }
 566
 567         if (genpd->cpuidle_data) {
 568                 /*
 569                  * If cpuidle_data is set, cpuidle should turn the domain off
 570                  * when the CPU in it is idle.  In that case we don't decrement
 571                  * the subdomain counts of the master domains, so that power is
 572                  * not removed from the current domain prematurely as a result
 573                  * of cutting off the masters' power.
 574                  */
 575                 genpd->status = GPD_STATE_POWER_OFF;
 576                 cpuidle_pause_and_lock();
 577                 genpd->cpuidle_data->idle_state->disabled = false;
 578                 cpuidle_resume_and_unlock();
 579                 goto out;
 580         }
 581
 582         if (genpd->power_off) {
 583                 if (atomic_read(&genpd->sd_count) > 0) {
 584                         ret = -EBUSY;
 585                         goto out;
 586                 }
 587
 588                 /*
 589                  * If sd_count > 0 at this point, one of the subdomains hasn't
 590                  * managed to call pm_genpd_poweron() for the master yet after
 591                  * incrementing it.  In that case pm_genpd_poweron() will wait
 592                  * for us to drop the lock, so we can call .power_off() and let
 593                  * the pm_genpd_poweron() restore power for us (this shouldn't
 594                  * happen very often).
 595                  */
 596                 ret = genpd_power_off(genpd);
 597                 if (ret == -EBUSY) {
 598                         genpd_set_active(genpd);
 599                         goto out;
 600                 }
 601         }
 602
 603         genpd->status = GPD_STATE_POWER_OFF;
 604
 605         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 606                 genpd_sd_counter_dec(link->master);
 607                 genpd_queue_power_off_work(link->master);
 608         }
 609
 610  out:
 611         genpd->poweroff_task = NULL;
 612         wake_up_all(&genpd->status_wait_queue);
 613         return ret;
 614 }
 615
 616 /**
 617  * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
 618  * @work: Work structure used for scheduling the execution of this function.
 619  */
 620 static void genpd_power_off_work_fn(struct work_struct *work)
 621 {
 622         struct generic_pm_domain *genpd;
 623
 624         genpd = container_of(work, struct generic_pm_domain, power_off_work);
 625
 626         genpd_acquire_lock(genpd);
 627         pm_genpd_poweroff(genpd);
 628         genpd_release_lock(genpd);
 629 }
 630
 631 /**
 632  * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
 633  * @dev: Device to suspend.
 634  *
 635  * Carry out a runtime suspend of a device under the assumption that its
 636  * pm_domain field points to the domain member of an object of type
 637  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 638  */
 639 static int pm_genpd_runtime_suspend(struct device *dev)
 640 {
 641         struct generic_pm_domain *genpd;
 642         struct generic_pm_domain_data *gpd_data;
 643         bool (*stop_ok)(struct device *__dev);
 644         int ret;
 645
 646         dev_dbg(dev, "%s()\n", __func__);
 647
 648         genpd = dev_to_genpd(dev);
 649         if (IS_ERR(genpd))
 650                 return -EINVAL;
 651
 652         stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
 653         if (stop_ok && !stop_ok(dev))
 654                 return -EBUSY;
 655
 656         ret = genpd_stop_dev(genpd, dev);
 657         if (ret)
 658                 return ret;
 659
 660         /*
 661          * If power.irq_safe is set, this routine will be run with interrupts
 662          * off, so it can't use mutexes.
 663          */
 664         if (dev->power.irq_safe)
 665                 return 0;
 666
 667         mutex_lock(&genpd->lock);
 668
 669         /*
 670          * If we have an unknown state of the need_restore flag, it means none
 671          * of the runtime PM callbacks has been invoked yet. Let's update the
 672          * flag to reflect that the current state is active.
 673          */
 674         gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
 675         if (gpd_data->need_restore < 0)
 676                 gpd_data->need_restore = 0;
 677
 678         genpd->in_progress++;
 679         pm_genpd_poweroff(genpd);
 680         genpd->in_progress--;
 681         mutex_unlock(&genpd->lock);
 682
 683         return 0;
 684 }
 685
 686 /**
 687  * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
 688  * @dev: Device to resume.
 689  *
 690  * Carry out a runtime resume of a device under the assumption that its
 691  * pm_domain field points to the domain member of an object of type
 692  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 693  */
 694 static int pm_genpd_runtime_resume(struct device *dev)
 695 {
 696         struct generic_pm_domain *genpd;
 697         DEFINE_WAIT(wait);
 698         int ret;
 699
 700         dev_dbg(dev, "%s()\n", __func__);
 701
 702         genpd = dev_to_genpd(dev);
 703         if (IS_ERR(genpd))
 704                 return -EINVAL;
 705
 706         /* If power.irq_safe, the PM domain is never powered off. */
 707         if (dev->power.irq_safe)
 708                 return genpd_start_dev_no_timing(genpd, dev);
 709
 710         mutex_lock(&genpd->lock);
 711         ret = __pm_genpd_poweron(genpd);
 712         if (ret) {
 713                 mutex_unlock(&genpd->lock);
 714                 return ret;
 715         }
 716         genpd->status = GPD_STATE_BUSY;
 717         genpd->resume_count++;
 718         for (;;) {
 719                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 720                                 TASK_UNINTERRUPTIBLE);
 721                 /*
 722                  * If current is the powering off task, we have been called
 723                  * reentrantly from one of the device callbacks, so we should
 724                  * not wait.
 725                  */
 726                 if (!genpd->poweroff_task || genpd->poweroff_task == current)
 727                         break;
 728                 mutex_unlock(&genpd->lock);
 729
 730                 schedule();
 731
 732                 mutex_lock(&genpd->lock);
 733         }
 734         finish_wait(&genpd->status_wait_queue, &wait);
 735         __pm_genpd_restore_device(dev->power.subsys_data->domain_data, genpd);
 736         genpd->resume_count--;
 737         genpd_set_active(genpd);
 738         wake_up_all(&genpd->status_wait_queue);
 739         mutex_unlock(&genpd->lock);
 740
 741         return 0;
 742 }
 743
 744 static bool pd_ignore_unused;
 745 static int __init pd_ignore_unused_setup(char *__unused)
 746 {
 747         pd_ignore_unused = true;
 748         return 1;
 749 }
 750 __setup("pd_ignore_unused", pd_ignore_unused_setup);
 751
 752 /**
 753  * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use.
 754  */
 755 void pm_genpd_poweroff_unused(void)
 756 {
 757         struct generic_pm_domain *genpd;
 758
 759         if (pd_ignore_unused) {
 760                 pr_warn("genpd: Not disabling unused power domains\n");
 761                 return;
 762         }
 763
 764         mutex_lock(&gpd_list_lock);
 765
 766         list_for_each_entry(genpd, &gpd_list, gpd_list_node)
 767                 genpd_queue_power_off_work(genpd);
 768
 769         mutex_unlock(&gpd_list_lock);
 770 }
 771
 772 static int __init genpd_poweroff_unused(void)
 773 {
 774         pm_genpd_poweroff_unused();
 775         return 0;
 776 }
 777 late_initcall(genpd_poweroff_unused);
 778
 779 #ifdef CONFIG_PM_SLEEP
 780
 781 /**
 782  * pm_genpd_present - Check if the given PM domain has been initialized.
 783  * @genpd: PM domain to check.
 784  */
 785 static bool pm_genpd_present(const struct generic_pm_domain *genpd)
 786 {
 787         const struct generic_pm_domain *gpd;
 788
 789         if (IS_ERR_OR_NULL(genpd))
 790                 return false;
 791
 792         list_for_each_entry(gpd, &gpd_list, gpd_list_node)
 793                 if (gpd == genpd)
 794                         return true;
 795
 796         return false;
 797 }
 798
 799 static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
 800                                     struct device *dev)
 801 {
 802         return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev);
 803 }
 804
 805 /**
 806  * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
 807  * @genpd: PM domain to power off, if possible.
 808  *
 809  * Check if the given PM domain can be powered off (during system suspend or
 810  * hibernation) and do that if so.  Also, in that case propagate to its masters.
 811  *
 812  * This function is only called in "noirq" and "syscore" stages of system power
 813  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 814  * executed sequentially, so it is guaranteed that it will never run twice in
 815  * parallel).
 816  */
 817 static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
 818 {
 819         struct gpd_link *link;
 820
 821         if (genpd->status == GPD_STATE_POWER_OFF)
 822                 return;
 823
 824         if (genpd->suspended_count != genpd->device_count
 825             || atomic_read(&genpd->sd_count) > 0)
 826                 return;
 827
 828         genpd_power_off(genpd);
 829
 830         genpd->status = GPD_STATE_POWER_OFF;
 831
 832         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 833                 genpd_sd_counter_dec(link->master);
 834                 pm_genpd_sync_poweroff(link->master);
 835         }
 836 }
 837
 838 /**
 839  * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters.
 840  * @genpd: PM domain to power on.
 841  *
 842  * This function is only called in "noirq" and "syscore" stages of system power
 843  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 844  * executed sequentially, so it is guaranteed that it will never run twice in
 845  * parallel).
 846  */
 847 static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)
 848 {
 849         struct gpd_link *link;
 850
 851         if (genpd->status != GPD_STATE_POWER_OFF)
 852                 return;
 853
 854         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 855                 pm_genpd_sync_poweron(link->master);
 856                 genpd_sd_counter_inc(link->master);
 857         }
 858
 859         genpd_power_on(genpd);
 860
 861         genpd->status = GPD_STATE_ACTIVE;
 862 }
 863
 864 /**
 865  * resume_needed - Check whether to resume a device before system suspend.
 866  * @dev: Device to check.
 867  * @genpd: PM domain the device belongs to.
 868  *
 869  * There are two cases in which a device that can wake up the system from sleep
 870  * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled
 871  * to wake up the system and it has to remain active for this purpose while the
 872  * system is in the sleep state and (2) if the device is not enabled to wake up
 873  * the system from sleep states and it generally doesn't generate wakeup signals
 874  * by itself (those signals are generated on its behalf by other parts of the
 875  * system).  In the latter case it may be necessary to reconfigure the device's
 876  * wakeup settings during system suspend, because it may have been set up to
 877  * signal remote wakeup from the system's working state as needed by runtime PM.
 878  * Return 'true' in either of the above cases.
 879  */
 880 static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd)
 881 {
 882         bool active_wakeup;
 883
 884         if (!device_can_wakeup(dev))
 885                 return false;
 886
 887         active_wakeup = genpd_dev_active_wakeup(genpd, dev);
 888         return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
 889 }
 890
 891 /**
 892  * pm_genpd_prepare - Start power transition of a device in a PM domain.
 893  * @dev: Device to start the transition of.
 894  *
 895  * Start a power transition of a device (during a system-wide power transition)
 896  * under the assumption that its pm_domain field points to the domain member of
 897  * an object of type struct generic_pm_domain representing a PM domain
 898  * consisting of I/O devices.
 899  */
 900 static int pm_genpd_prepare(struct device *dev)
 901 {
 902         struct generic_pm_domain *genpd;
 903         int ret;
 904
 905         dev_dbg(dev, "%s()\n", __func__);
 906
 907         genpd = dev_to_genpd(dev);
 908         if (IS_ERR(genpd))
 909                 return -EINVAL;
 910
 911         /*
 912          * If a wakeup request is pending for the device, it should be woken up
 913          * at this point and a system wakeup event should be reported if it's
 914          * set up to wake up the system from sleep states.
 915          */
 916         pm_runtime_get_noresume(dev);
 917         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
 918                 pm_wakeup_event(dev, 0);
 919
 920         if (pm_wakeup_pending()) {
 921                 pm_runtime_put(dev);
 922                 return -EBUSY;
 923         }
 924
 925         if (resume_needed(dev, genpd))
 926                 pm_runtime_resume(dev);
 927
 928         genpd_acquire_lock(genpd);
 929
 930         if (genpd->prepared_count++ == 0) {
 931                 genpd->suspended_count = 0;
 932                 genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF;
 933         }
 934
 935         genpd_release_lock(genpd);
 936
 937         if (genpd->suspend_power_off) {
 938                 pm_runtime_put_noidle(dev);
 939                 return 0;
 940         }
 941
 942         /*
 943          * The PM domain must be in the GPD_STATE_ACTIVE state at this point,
 944          * so pm_genpd_poweron() will return immediately, but if the device
 945          * is suspended (e.g. it's been stopped by genpd_stop_dev()), we need
 946          * to make it operational.
 947          */
 948         pm_runtime_resume(dev);
 949         __pm_runtime_disable(dev, false);
 950
 951         ret = pm_generic_prepare(dev);
 952         if (ret) {
 953                 mutex_lock(&genpd->lock);
 954
 955                 if (--genpd->prepared_count == 0)
 956                         genpd->suspend_power_off = false;
 957
 958                 mutex_unlock(&genpd->lock);
 959                 pm_runtime_enable(dev);
 960         }
 961
 962         pm_runtime_put(dev);
 963         return ret;
 964 }
 965
 966 /**
 967  * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain.
 968  * @dev: Device to suspend.
 969  *
 970  * Suspend a device under the assumption that its pm_domain field points to the
 971  * domain member of an object of type struct generic_pm_domain representing
 972  * a PM domain consisting of I/O devices.
 973  */
 974 static int pm_genpd_suspend(struct device *dev)
 975 {
 976         struct generic_pm_domain *genpd;
 977
 978         dev_dbg(dev, "%s()\n", __func__);
 979
 980         genpd = dev_to_genpd(dev);
 981         if (IS_ERR(genpd))
 982                 return -EINVAL;
 983
 984         return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev);
 985 }
 986
 987 /**
 988  * pm_genpd_suspend_late - Late suspend of a device from an I/O PM domain.
 989  * @dev: Device to suspend.
 990  *
 991  * Carry out a late suspend of a device under the assumption that its
 992  * pm_domain field points to the domain member of an object of type
 993  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 994  */
 995 static int pm_genpd_suspend_late(struct device *dev)
 996 {
 997         struct generic_pm_domain *genpd;
 998
 999         dev_dbg(dev, "%s()\n", __func__);
1000
1001         genpd = dev_to_genpd(dev);
1002         if (IS_ERR(genpd))
1003                 return -EINVAL;
1004
1005         return genpd->suspend_power_off ? 0 : pm_generic_suspend_late(dev);
1006 }
1007
1008 /**
1009  * pm_genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
1010  * @dev: Device to suspend.
1011  *
1012  * Stop the device and remove power from the domain if all devices in it have
1013  * been stopped.
1014  */
1015 static int pm_genpd_suspend_noirq(struct device *dev)
1016 {
1017         struct generic_pm_domain *genpd;
1018
1019         dev_dbg(dev, "%s()\n", __func__);
1020
1021         genpd = dev_to_genpd(dev);
1022         if (IS_ERR(genpd))
1023                 return -EINVAL;
1024
1025         if (genpd->suspend_power_off
1026             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1027                 return 0;
1028
1029         genpd_stop_dev(genpd, dev);
1030
1031         /*
1032          * Since all of the "noirq" callbacks are executed sequentially, it is
1033          * guaranteed that this function will never run twice in parallel for
1034          * the same PM domain, so it is not necessary to use locking here.
1035          */
1036         genpd->suspended_count++;
1037         pm_genpd_sync_poweroff(genpd);
1038
1039         return 0;
1040 }
1041
1042 /**
1043  * pm_genpd_resume_noirq - Start of resume of device in an I/O PM domain.
1044  * @dev: Device to resume.
1045  *
1046  * Restore power to the device's PM domain, if necessary, and start the device.
1047  */
1048 static int pm_genpd_resume_noirq(struct device *dev)
1049 {
1050         struct generic_pm_domain *genpd;
1051
1052         dev_dbg(dev, "%s()\n", __func__);
1053
1054         genpd = dev_to_genpd(dev);
1055         if (IS_ERR(genpd))
1056                 return -EINVAL;
1057
1058         if (genpd->suspend_power_off
1059             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1060                 return 0;
1061
1062         /*
1063          * Since all of the "noirq" callbacks are executed sequentially, it is
1064          * guaranteed that this function will never run twice in parallel for
1065          * the same PM domain, so it is not necessary to use locking here.
1066          */
1067         pm_genpd_sync_poweron(genpd);
1068         genpd->suspended_count--;
1069
1070         return genpd_start_dev(genpd, dev);
1071 }
1072
1073 /**
1074  * pm_genpd_resume_early - Early resume of a device in an I/O PM domain.
1075  * @dev: Device to resume.
1076  *
1077  * Carry out an early resume of a device under the assumption that its
1078  * pm_domain field points to the domain member of an object of type
1079  * struct generic_pm_domain representing a power domain consisting of I/O
1080  * devices.
1081  */
1082 static int pm_genpd_resume_early(struct device *dev)
1083 {
1084         struct generic_pm_domain *genpd;
1085
1086         dev_dbg(dev, "%s()\n", __func__);
1087
1088         genpd = dev_to_genpd(dev);
1089         if (IS_ERR(genpd))
1090                 return -EINVAL;
1091
1092         return genpd->suspend_power_off ? 0 : pm_generic_resume_early(dev);
1093 }
1094
1095 /**
1096  * pm_genpd_resume - Resume of device in an I/O PM domain.
1097  * @dev: Device to resume.
1098  *
1099  * Resume a device under the assumption that its pm_domain field points to the
1100  * domain member of an object of type struct generic_pm_domain representing
1101  * a power domain consisting of I/O devices.
1102  */
1103 static int pm_genpd_resume(struct device *dev)
1104 {
1105         struct generic_pm_domain *genpd;
1106
1107         dev_dbg(dev, "%s()\n", __func__);
1108
1109         genpd = dev_to_genpd(dev);
1110         if (IS_ERR(genpd))
1111                 return -EINVAL;
1112
1113         return genpd->suspend_power_off ? 0 : pm_generic_resume(dev);
1114 }
1115
1116 /**
1117  * pm_genpd_freeze - Freezing a device in an I/O PM domain.
1118  * @dev: Device to freeze.
1119  *
1120  * Freeze a device under the assumption that its pm_domain field points to the
1121  * domain member of an object of type struct generic_pm_domain representing
1122  * a power domain consisting of I/O devices.
1123  */
1124 static int pm_genpd_freeze(struct device *dev)
1125 {
1126         struct generic_pm_domain *genpd;
1127
1128         dev_dbg(dev, "%s()\n", __func__);
1129
1130         genpd = dev_to_genpd(dev);
1131         if (IS_ERR(genpd))
1132                 return -EINVAL;
1133
1134         return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev);
1135 }
1136
1137 /**
1138  * pm_genpd_freeze_late - Late freeze of a device in an I/O PM domain.
1139  * @dev: Device to freeze.
1140  *
1141  * Carry out a late freeze of a device under the assumption that its
1142  * pm_domain field points to the domain member of an object of type
1143  * struct generic_pm_domain representing a power domain consisting of I/O
1144  * devices.
1145  */
1146 static int pm_genpd_freeze_late(struct device *dev)
1147 {
1148         struct generic_pm_domain *genpd;
1149
1150         dev_dbg(dev, "%s()\n", __func__);
1151
1152         genpd = dev_to_genpd(dev);
1153         if (IS_ERR(genpd))
1154                 return -EINVAL;
1155
1156         return genpd->suspend_power_off ? 0 : pm_generic_freeze_late(dev);
1157 }
1158
1159 /**
1160  * pm_genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
1161  * @dev: Device to freeze.
1162  *
1163  * Carry out a late freeze of a device under the assumption that its
1164  * pm_domain field points to the domain member of an object of type
1165  * struct generic_pm_domain representing a power domain consisting of I/O
1166  * devices.
1167  */
1168 static int pm_genpd_freeze_noirq(struct device *dev)
1169 {
1170         struct generic_pm_domain *genpd;
1171
1172         dev_dbg(dev, "%s()\n", __func__);
1173
1174         genpd = dev_to_genpd(dev);
1175         if (IS_ERR(genpd))
1176                 return -EINVAL;
1177
1178         return genpd->suspend_power_off ? 0 : genpd_stop_dev(genpd, dev);
1179 }
1180
1181 /**
1182  * pm_genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
1183  * @dev: Device to thaw.
1184  *
1185  * Start the device, unless power has been removed from the domain already
1186  * before the system transition.
1187  */
1188 static int pm_genpd_thaw_noirq(struct device *dev)
1189 {
1190         struct generic_pm_domain *genpd;
1191
1192         dev_dbg(dev, "%s()\n", __func__);
1193
1194         genpd = dev_to_genpd(dev);
1195         if (IS_ERR(genpd))
1196                 return -EINVAL;
1197
1198         return genpd->suspend_power_off ? 0 : genpd_start_dev(genpd, dev);
1199 }
1200
1201 /**
1202  * pm_genpd_thaw_early - Early thaw of device in an I/O PM domain.
1203  * @dev: Device to thaw.
1204  *
1205  * Carry out an early thaw of a device under the assumption that its
1206  * pm_domain field points to the domain member of an object of type
1207  * struct generic_pm_domain representing a power domain consisting of I/O
1208  * devices.
1209  */
1210 static int pm_genpd_thaw_early(struct device *dev)
1211 {
1212         struct generic_pm_domain *genpd;
1213
1214         dev_dbg(dev, "%s()\n", __func__);
1215
1216         genpd = dev_to_genpd(dev);
1217         if (IS_ERR(genpd))
1218                 return -EINVAL;
1219
1220         return genpd->suspend_power_off ? 0 : pm_generic_thaw_early(dev);
1221 }
1222
1223 /**
1224  * pm_genpd_thaw - Thaw a device belonging to an I/O power domain.
1225  * @dev: Device to thaw.
1226  *
1227  * Thaw a device under the assumption that its pm_domain field points to the
1228  * domain member of an object of type struct generic_pm_domain representing
1229  * a power domain consisting of I/O devices.
1230  */
1231 static int pm_genpd_thaw(struct device *dev)
1232 {
1233         struct generic_pm_domain *genpd;
1234
1235         dev_dbg(dev, "%s()\n", __func__);
1236
1237         genpd = dev_to_genpd(dev);
1238         if (IS_ERR(genpd))
1239                 return -EINVAL;
1240
1241         return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev);
1242 }
1243
1244 /**
1245  * pm_genpd_restore_noirq - Start of restore of device in an I/O PM domain.
1246  * @dev: Device to resume.
1247  *
1248  * Make sure the domain will be in the same power state as before the
1249  * hibernation the system is resuming from and start the device if necessary.
1250  */
1251 static int pm_genpd_restore_noirq(struct device *dev)
1252 {
1253         struct generic_pm_domain *genpd;
1254
1255         dev_dbg(dev, "%s()\n", __func__);
1256
1257         genpd = dev_to_genpd(dev);
1258         if (IS_ERR(genpd))
1259                 return -EINVAL;
1260
1261         /*
1262          * Since all of the "noirq" callbacks are executed sequentially, it is
1263          * guaranteed that this function will never run twice in parallel for
1264          * the same PM domain, so it is not necessary to use locking here.
1265          *
1266          * At this point suspended_count == 0 means we are being run for the
1267          * first time for the given domain in the present cycle.
1268          */
1269         if (genpd->suspended_count++ == 0) {
1270                 /*
1271                  * The boot kernel might put the domain into arbitrary state,
1272                  * so make it appear as powered off to pm_genpd_sync_poweron(),
1273                  * so that it tries to power it on in case it was really off.
1274                  */
1275                 genpd->status = GPD_STATE_POWER_OFF;
1276                 if (genpd->suspend_power_off) {
1277                         /*
1278                          * If the domain was off before the hibernation, make
1279                          * sure it will be off going forward.
1280                          */
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 /* !CONFIG_PM_SLEEP */
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
1933         if (genpd->flags & GENPD_FLAG_PM_CLK) {
1934                 genpd->dev_ops.stop = pm_clk_suspend;
1935                 genpd->dev_ops.start = pm_clk_resume;
1936         }
1937
1938         mutex_lock(&gpd_list_lock);
1939         list_add(&genpd->gpd_list_node, &gpd_list);
1940         mutex_unlock(&gpd_list_lock);
1941 }
1942
1943 #ifdef CONFIG_PM_GENERIC_DOMAINS_OF
1944 /*
1945  * Device Tree based PM domain providers.
1946  *
1947  * The code below implements generic device tree based PM domain providers that
1948  * bind device tree nodes with generic PM domains registered in the system.
1949  *
1950  * Any driver that registers generic PM domains and needs to support binding of
1951  * devices to these domains is supposed to register a PM domain provider, which
1952  * maps a PM domain specifier retrieved from the device tree to a PM domain.
1953  *
1954  * Two simple mapping functions have been provided for convenience:
1955  *  - __of_genpd_xlate_simple() for 1:1 device tree node to PM domain mapping.
1956  *  - __of_genpd_xlate_onecell() for mapping of multiple PM domains per node by
1957  *    index.
1958  */
1959
1960 /**
1961  * struct of_genpd_provider - PM domain provider registration structure
1962  * @link: Entry in global list of PM domain providers
1963  * @node: Pointer to device tree node of PM domain provider
1964  * @xlate: Provider-specific xlate callback mapping a set of specifier cells
1965  *         into a PM domain.
1966  * @data: context pointer to be passed into @xlate callback
1967  */
1968 struct of_genpd_provider {
1969         struct list_head link;
1970         struct device_node *node;
1971         genpd_xlate_t xlate;
1972         void *data;
1973 };
1974
1975 /* List of registered PM domain providers. */
1976 static LIST_HEAD(of_genpd_providers);
1977 /* Mutex to protect the list above. */
1978 static DEFINE_MUTEX(of_genpd_mutex);
1979
1980 /**
1981  * __of_genpd_xlate_simple() - Xlate function for direct node-domain mapping
1982  * @genpdspec: OF phandle args to map into a PM domain
1983  * @data: xlate function private data - pointer to struct generic_pm_domain
1984  *
1985  * This is a generic xlate function that can be used to model PM domains that
1986  * have their own device tree nodes. The private data of xlate function needs
1987  * to be a valid pointer to struct generic_pm_domain.
1988  */
1989 struct generic_pm_domain *__of_genpd_xlate_simple(
1990                                         struct of_phandle_args *genpdspec,
1991                                         void *data)
1992 {
1993         if (genpdspec->args_count != 0)
1994                 return ERR_PTR(-EINVAL);
1995         return data;
1996 }
1997 EXPORT_SYMBOL_GPL(__of_genpd_xlate_simple);
1998
1999 /**
2000  * __of_genpd_xlate_onecell() - Xlate function using a single index.
2001  * @genpdspec: OF phandle args to map into a PM domain
2002  * @data: xlate function private data - pointer to struct genpd_onecell_data
2003  *
2004  * This is a generic xlate function that can be used to model simple PM domain
2005  * controllers that have one device tree node and provide multiple PM domains.
2006  * A single cell is used as an index into an array of PM domains specified in
2007  * the genpd_onecell_data struct when registering the provider.
2008  */
2009 struct generic_pm_domain *__of_genpd_xlate_onecell(
2010                                         struct of_phandle_args *genpdspec,
2011                                         void *data)
2012 {
2013         struct genpd_onecell_data *genpd_data = data;
2014         unsigned int idx = genpdspec->args[0];
2015
2016         if (genpdspec->args_count != 1)
2017                 return ERR_PTR(-EINVAL);
2018
2019         if (idx >= genpd_data->num_domains) {
2020                 pr_err("%s: invalid domain index %u\n", __func__, idx);
2021                 return ERR_PTR(-EINVAL);
2022         }
2023
2024         if (!genpd_data->domains[idx])
2025                 return ERR_PTR(-ENOENT);
2026
2027         return genpd_data->domains[idx];
2028 }
2029 EXPORT_SYMBOL_GPL(__of_genpd_xlate_onecell);
2030
2031 /**
2032  * __of_genpd_add_provider() - Register a PM domain provider for a node
2033  * @np: Device node pointer associated with the PM domain provider.
2034  * @xlate: Callback for decoding PM domain from phandle arguments.
2035  * @data: Context pointer for @xlate callback.
2036  */
2037 int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate,
2038                         void *data)
2039 {
2040         struct of_genpd_provider *cp;
2041
2042         cp = kzalloc(sizeof(*cp), GFP_KERNEL);
2043         if (!cp)
2044                 return -ENOMEM;
2045
2046         cp->node = of_node_get(np);
2047         cp->data = data;
2048         cp->xlate = xlate;
2049
2050         mutex_lock(&of_genpd_mutex);
2051         list_add(&cp->link, &of_genpd_providers);
2052         mutex_unlock(&of_genpd_mutex);
2053         pr_debug("Added domain provider from %s\n", np->full_name);
2054
2055         return 0;
2056 }
2057 EXPORT_SYMBOL_GPL(__of_genpd_add_provider);
2058
2059 /**
2060  * of_genpd_del_provider() - Remove a previously registered PM domain provider
2061  * @np: Device node pointer associated with the PM domain provider
2062  */
2063 void of_genpd_del_provider(struct device_node *np)
2064 {
2065         struct of_genpd_provider *cp;
2066
2067         mutex_lock(&of_genpd_mutex);
2068         list_for_each_entry(cp, &of_genpd_providers, link) {
2069                 if (cp->node == np) {
2070                         list_del(&cp->link);
2071                         of_node_put(cp->node);
2072                         kfree(cp);
2073                         break;
2074                 }
2075         }
2076         mutex_unlock(&of_genpd_mutex);
2077 }
2078 EXPORT_SYMBOL_GPL(of_genpd_del_provider);
2079
2080 /**
2081  * of_genpd_get_from_provider() - Look-up PM domain
2082  * @genpdspec: OF phandle args to use for look-up
2083  *
2084  * Looks for a PM domain provider under the node specified by @genpdspec and if
2085  * found, uses xlate function of the provider to map phandle args to a PM
2086  * domain.
2087  *
2088  * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
2089  * on failure.
2090  */
2091 struct generic_pm_domain *of_genpd_get_from_provider(
2092                                         struct of_phandle_args *genpdspec)
2093 {
2094         struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
2095         struct of_genpd_provider *provider;
2096
2097         mutex_lock(&of_genpd_mutex);
2098
2099         /* Check if we have such a provider in our array */
2100         list_for_each_entry(provider, &of_genpd_providers, link) {
2101                 if (provider->node == genpdspec->np)
2102                         genpd = provider->xlate(genpdspec, provider->data);
2103                 if (!IS_ERR(genpd))
2104                         break;
2105         }
2106
2107         mutex_unlock(&of_genpd_mutex);
2108
2109         return genpd;
2110 }
2111 EXPORT_SYMBOL_GPL(of_genpd_get_from_provider);
2112
2113 /**
2114  * genpd_dev_pm_detach - Detach a device from its PM domain.
2115  * @dev: Device to attach.
2116  * @power_off: Currently not used
2117  *
2118  * Try to locate a corresponding generic PM domain, which the device was
2119  * attached to previously. If such is found, the device is detached from it.
2120  */
2121 static void genpd_dev_pm_detach(struct device *dev, bool power_off)
2122 {
2123         struct generic_pm_domain *pd = NULL, *gpd;
2124         int ret = 0;
2125
2126         if (!dev->pm_domain)
2127                 return;
2128
2129         mutex_lock(&gpd_list_lock);
2130         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
2131                 if (&gpd->domain == dev->pm_domain) {
2132                         pd = gpd;
2133                         break;
2134                 }
2135         }
2136         mutex_unlock(&gpd_list_lock);
2137
2138         if (!pd)
2139                 return;
2140
2141         dev_dbg(dev, "removing from PM domain %s\n", pd->name);
2142
2143         while (1) {
2144                 ret = pm_genpd_remove_device(pd, dev);
2145                 if (ret != -EAGAIN)
2146                         break;
2147                 cond_resched();
2148         }
2149
2150         if (ret < 0) {
2151                 dev_err(dev, "failed to remove from PM domain %s: %d",
2152                         pd->name, ret);
2153                 return;
2154         }
2155
2156         /* Check if PM domain can be powered off after removing this device. */
2157         genpd_queue_power_off_work(pd);
2158 }
2159
2160 /**
2161  * genpd_dev_pm_attach - Attach a device to its PM domain using DT.
2162  * @dev: Device to attach.
2163  *
2164  * Parse device's OF node to find a PM domain specifier. If such is found,
2165  * attaches the device to retrieved pm_domain ops.
2166  *
2167  * Both generic and legacy Samsung-specific DT bindings are supported to keep
2168  * backwards compatibility with existing DTBs.
2169  *
2170  * Returns 0 on successfully attached PM domain or negative error code.
2171  */
2172 int genpd_dev_pm_attach(struct device *dev)
2173 {
2174         struct of_phandle_args pd_args;
2175         struct generic_pm_domain *pd;
2176         int ret;
2177
2178         if (!dev->of_node)
2179                 return -ENODEV;
2180
2181         if (dev->pm_domain)
2182                 return -EEXIST;
2183
2184         ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
2185                                         "#power-domain-cells", 0, &pd_args);
2186         if (ret < 0) {
2187                 if (ret != -ENOENT)
2188                         return ret;
2189
2190                 /*
2191                  * Try legacy Samsung-specific bindings
2192                  * (for backwards compatibility of DT ABI)
2193                  */
2194                 pd_args.args_count = 0;
2195                 pd_args.np = of_parse_phandle(dev->of_node,
2196                                                 "samsung,power-domain", 0);
2197                 if (!pd_args.np)
2198                         return -ENOENT;
2199         }
2200
2201         pd = of_genpd_get_from_provider(&pd_args);
2202         if (IS_ERR(pd)) {
2203                 dev_dbg(dev, "%s() failed to find PM domain: %ld\n",
2204                         __func__, PTR_ERR(pd));
2205                 of_node_put(dev->of_node);
2206                 return PTR_ERR(pd);
2207         }
2208
2209         dev_dbg(dev, "adding to PM domain %s\n", pd->name);
2210
2211         while (1) {
2212                 ret = pm_genpd_add_device(pd, dev);
2213                 if (ret != -EAGAIN)
2214                         break;
2215                 cond_resched();
2216         }
2217
2218         if (ret < 0) {
2219                 dev_err(dev, "failed to add to PM domain %s: %d",
2220                         pd->name, ret);
2221                 of_node_put(dev->of_node);
2222                 return ret;
2223         }
2224
2225         dev->pm_domain->detach = genpd_dev_pm_detach;
2226         pm_genpd_poweron(pd);
2227
2228         return 0;
2229 }
2230 EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
2231 #endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
2232
2233
2234 /***        debugfs support        ***/
2235
2236 #ifdef CONFIG_PM_ADVANCED_DEBUG
2237 #include <linux/pm.h>
2238 #include <linux/device.h>
2239 #include <linux/debugfs.h>
2240 #include <linux/seq_file.h>
2241 #include <linux/init.h>
2242 #include <linux/kobject.h>
2243 static struct dentry *pm_genpd_debugfs_dir;
2244
2245 /*
2246  * TODO: This function is a slightly modified version of rtpm_status_show
2247  * from sysfs.c, so generalize it.
2248  */
2249 static void rtpm_status_str(struct seq_file *s, struct device *dev)
2250 {
2251         static const char * const status_lookup[] = {
2252                 [RPM_ACTIVE] = "active",
2253                 [RPM_RESUMING] = "resuming",
2254                 [RPM_SUSPENDED] = "suspended",
2255                 [RPM_SUSPENDING] = "suspending"
2256         };
2257         const char *p = "";
2258
2259         if (dev->power.runtime_error)
2260                 p = "error";
2261         else if (dev->power.disable_depth)
2262                 p = "unsupported";
2263         else if (dev->power.runtime_status < ARRAY_SIZE(status_lookup))
2264                 p = status_lookup[dev->power.runtime_status];
2265         else
2266                 WARN_ON(1);
2267
2268         seq_puts(s, p);
2269 }
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 */