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