drivers/thermal/thermal_core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  thermal.c - Generic Thermal Management Sysfs support.
   4  *
   5  *  Copyright (C) 2008 Intel Corp
   6  *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
   7  *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
   8  */
   9
  10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  11
  12 #include <linux/device.h>
  13 #include <linux/err.h>
  14 #include <linux/export.h>
  15 #include <linux/slab.h>
  16 #include <linux/kdev_t.h>
  17 #include <linux/idr.h>
  18 #include <linux/thermal.h>
  19 #include <linux/reboot.h>
  20 #include <linux/string.h>
  21 #include <linux/of.h>
  22 #include <linux/suspend.h>
  23
  24 #define CREATE_TRACE_POINTS
  25 #include "thermal_trace.h"
  26
  27 #include "thermal_core.h"
  28 #include "thermal_hwmon.h"
  29
  30 static DEFINE_IDA(thermal_tz_ida);
  31 static DEFINE_IDA(thermal_cdev_ida);
  32
  33 static LIST_HEAD(thermal_tz_list);
  34 static LIST_HEAD(thermal_cdev_list);
  35 static LIST_HEAD(thermal_governor_list);
  36
  37 static DEFINE_MUTEX(thermal_list_lock);
  38 static DEFINE_MUTEX(thermal_governor_lock);
  39
  40 static atomic_t in_suspend;
  41
  42 static struct thermal_governor *def_governor;
  43
  44 /*
  45  * Governor section: set of functions to handle thermal governors
  46  *
  47  * Functions to help in the life cycle of thermal governors within
  48  * the thermal core and by the thermal governor code.
  49  */
  50
  51 static struct thermal_governor *__find_governor(const char *name)
  52 {
  53         struct thermal_governor *pos;
  54
  55         if (!name || !name[0])
  56                 return def_governor;
  57
  58         list_for_each_entry(pos, &thermal_governor_list, governor_list)
  59                 if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
  60                         return pos;
  61
  62         return NULL;
  63 }
  64
  65 /**
  66  * bind_previous_governor() - bind the previous governor of the thermal zone
  67  * @tz:         a valid pointer to a struct thermal_zone_device
  68  * @failed_gov_name:    the name of the governor that failed to register
  69  *
  70  * Register the previous governor of the thermal zone after a new
  71  * governor has failed to be bound.
  72  */
  73 static void bind_previous_governor(struct thermal_zone_device *tz,
  74                                    const char *failed_gov_name)
  75 {
  76         if (tz->governor && tz->governor->bind_to_tz) {
  77                 if (tz->governor->bind_to_tz(tz)) {
  78                         dev_err(&tz->device,
  79                                 "governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
  80                                 failed_gov_name, tz->governor->name, tz->type);
  81                         tz->governor = NULL;
  82                 }
  83         }
  84 }
  85
  86 /**
  87  * thermal_set_governor() - Switch to another governor
  88  * @tz:         a valid pointer to a struct thermal_zone_device
  89  * @new_gov:    pointer to the new governor
  90  *
  91  * Change the governor of thermal zone @tz.
  92  *
  93  * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
  94  */
  95 static int thermal_set_governor(struct thermal_zone_device *tz,
  96                                 struct thermal_governor *new_gov)
  97 {
  98         int ret = 0;
  99
 100         if (tz->governor && tz->governor->unbind_from_tz)
 101                 tz->governor->unbind_from_tz(tz);
 102
 103         if (new_gov && new_gov->bind_to_tz) {
 104                 ret = new_gov->bind_to_tz(tz);
 105                 if (ret) {
 106                         bind_previous_governor(tz, new_gov->name);
 107
 108                         return ret;
 109                 }
 110         }
 111
 112         tz->governor = new_gov;
 113
 114         return ret;
 115 }
 116
 117 int thermal_register_governor(struct thermal_governor *governor)
 118 {
 119         int err;
 120         const char *name;
 121         struct thermal_zone_device *pos;
 122
 123         if (!governor)
 124                 return -EINVAL;
 125
 126         mutex_lock(&thermal_governor_lock);
 127
 128         err = -EBUSY;
 129         if (!__find_governor(governor->name)) {
 130                 bool match_default;
 131
 132                 err = 0;
 133                 list_add(&governor->governor_list, &thermal_governor_list);
 134                 match_default = !strncmp(governor->name,
 135                                          DEFAULT_THERMAL_GOVERNOR,
 136                                          THERMAL_NAME_LENGTH);
 137
 138                 if (!def_governor && match_default)
 139                         def_governor = governor;
 140         }
 141
 142         mutex_lock(&thermal_list_lock);
 143
 144         list_for_each_entry(pos, &thermal_tz_list, node) {
 145                 /*
 146                  * only thermal zones with specified tz->tzp->governor_name
 147                  * may run with tz->govenor unset
 148                  */
 149                 if (pos->governor)
 150                         continue;
 151
 152                 name = pos->tzp->governor_name;
 153
 154                 if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
 155                         int ret;
 156
 157                         ret = thermal_set_governor(pos, governor);
 158                         if (ret)
 159                                 dev_err(&pos->device,
 160                                         "Failed to set governor %s for thermal zone %s: %d\n",
 161                                         governor->name, pos->type, ret);
 162                 }
 163         }
 164
 165         mutex_unlock(&thermal_list_lock);
 166         mutex_unlock(&thermal_governor_lock);
 167
 168         return err;
 169 }
 170
 171 void thermal_unregister_governor(struct thermal_governor *governor)
 172 {
 173         struct thermal_zone_device *pos;
 174
 175         if (!governor)
 176                 return;
 177
 178         mutex_lock(&thermal_governor_lock);
 179
 180         if (!__find_governor(governor->name))
 181                 goto exit;
 182
 183         mutex_lock(&thermal_list_lock);
 184
 185         list_for_each_entry(pos, &thermal_tz_list, node) {
 186                 if (!strncasecmp(pos->governor->name, governor->name,
 187                                  THERMAL_NAME_LENGTH))
 188                         thermal_set_governor(pos, NULL);
 189         }
 190
 191         mutex_unlock(&thermal_list_lock);
 192         list_del(&governor->governor_list);
 193 exit:
 194         mutex_unlock(&thermal_governor_lock);
 195 }
 196
 197 int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
 198                                    char *policy)
 199 {
 200         struct thermal_governor *gov;
 201         int ret = -EINVAL;
 202
 203         mutex_lock(&thermal_governor_lock);
 204         mutex_lock(&tz->lock);
 205
 206         if (!device_is_registered(&tz->device))
 207                 goto exit;
 208
 209         gov = __find_governor(strim(policy));
 210         if (!gov)
 211                 goto exit;
 212
 213         ret = thermal_set_governor(tz, gov);
 214
 215 exit:
 216         mutex_unlock(&tz->lock);
 217         mutex_unlock(&thermal_governor_lock);
 218
 219         thermal_notify_tz_gov_change(tz->id, policy);
 220
 221         return ret;
 222 }
 223
 224 int thermal_build_list_of_policies(char *buf)
 225 {
 226         struct thermal_governor *pos;
 227         ssize_t count = 0;
 228
 229         mutex_lock(&thermal_governor_lock);
 230
 231         list_for_each_entry(pos, &thermal_governor_list, governor_list) {
 232                 count += sysfs_emit_at(buf, count, "%s ", pos->name);
 233         }
 234         count += sysfs_emit_at(buf, count, "\n");
 235
 236         mutex_unlock(&thermal_governor_lock);
 237
 238         return count;
 239 }
 240
 241 static void __init thermal_unregister_governors(void)
 242 {
 243         struct thermal_governor **governor;
 244
 245         for_each_governor_table(governor)
 246                 thermal_unregister_governor(*governor);
 247 }
 248
 249 static int __init thermal_register_governors(void)
 250 {
 251         int ret = 0;
 252         struct thermal_governor **governor;
 253
 254         for_each_governor_table(governor) {
 255                 ret = thermal_register_governor(*governor);
 256                 if (ret) {
 257                         pr_err("Failed to register governor: '%s'",
 258                                (*governor)->name);
 259                         break;
 260                 }
 261
 262                 pr_info("Registered thermal governor '%s'",
 263                         (*governor)->name);
 264         }
 265
 266         if (ret) {
 267                 struct thermal_governor **gov;
 268
 269                 for_each_governor_table(gov) {
 270                         if (gov == governor)
 271                                 break;
 272                         thermal_unregister_governor(*gov);
 273                 }
 274         }
 275
 276         return ret;
 277 }
 278
 279 /*
 280  * Zone update section: main control loop applied to each zone while monitoring
 281  *
 282  * in polling mode. The monitoring is done using a workqueue.
 283  * Same update may be done on a zone by calling thermal_zone_device_update().
 284  *
 285  * An update means:
 286  * - Non-critical trips will invoke the governor responsible for that zone;
 287  * - Hot trips will produce a notification to userspace;
 288  * - Critical trip point will cause a system shutdown.
 289  */
 290 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 291                                             unsigned long delay)
 292 {
 293         if (delay)
 294                 mod_delayed_work(system_freezable_power_efficient_wq,
 295                                  &tz->poll_queue, delay);
 296         else
 297                 cancel_delayed_work(&tz->poll_queue);
 298 }
 299
 300 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 301 {
 302         if (tz->mode != THERMAL_DEVICE_ENABLED)
 303                 thermal_zone_device_set_polling(tz, 0);
 304         else if (tz->passive)
 305                 thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
 306         else if (tz->polling_delay_jiffies)
 307                 thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
 308 }
 309
 310 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 311 {
 312         tz->governor ? tz->governor->throttle(tz, trip) :
 313                        def_governor->throttle(tz, trip);
 314 }
 315
 316 void thermal_zone_device_critical(struct thermal_zone_device *tz)
 317 {
 318         /*
 319          * poweroff_delay_ms must be a carefully profiled positive value.
 320          * Its a must for forced_emergency_poweroff_work to be scheduled.
 321          */
 322         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 323
 324         dev_emerg(&tz->device, "%s: critical temperature reached, "
 325                   "shutting down\n", tz->type);
 326
 327         hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
 328 }
 329 EXPORT_SYMBOL(thermal_zone_device_critical);
 330
 331 static void handle_critical_trips(struct thermal_zone_device *tz,
 332                                   int trip, int trip_temp, enum thermal_trip_type trip_type)
 333 {
 334         /* If we have not crossed the trip_temp, we do not care. */
 335         if (trip_temp <= 0 || tz->temperature < trip_temp)
 336                 return;
 337
 338         trace_thermal_zone_trip(tz, trip, trip_type);
 339
 340         if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
 341                 tz->ops->hot(tz);
 342         else if (trip_type == THERMAL_TRIP_CRITICAL)
 343                 tz->ops->critical(tz);
 344 }
 345
 346 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip_id)
 347 {
 348         struct thermal_trip trip;
 349
 350         /* Ignore disabled trip points */
 351         if (test_bit(trip_id, &tz->trips_disabled))
 352                 return;
 353
 354         __thermal_zone_get_trip(tz, trip_id, &trip);
 355
 356         if (tz->last_temperature != THERMAL_TEMP_INVALID) {
 357                 if (tz->last_temperature < trip.temperature &&
 358                     tz->temperature >= trip.temperature)
 359                         thermal_notify_tz_trip_up(tz->id, trip_id,
 360                                                   tz->temperature);
 361                 if (tz->last_temperature >= trip.temperature &&
 362                     tz->temperature < (trip.temperature - trip.hysteresis))
 363                         thermal_notify_tz_trip_down(tz->id, trip_id,
 364                                                     tz->temperature);
 365         }
 366
 367         if (trip.type == THERMAL_TRIP_CRITICAL || trip.type == THERMAL_TRIP_HOT)
 368                 handle_critical_trips(tz, trip_id, trip.temperature, trip.type);
 369         else
 370                 handle_non_critical_trips(tz, trip_id);
 371 }
 372
 373 static void update_temperature(struct thermal_zone_device *tz)
 374 {
 375         int temp, ret;
 376
 377         ret = __thermal_zone_get_temp(tz, &temp);
 378         if (ret) {
 379                 if (ret != -EAGAIN)
 380                         dev_warn(&tz->device,
 381                                  "failed to read out thermal zone (%d)\n",
 382                                  ret);
 383                 return;
 384         }
 385
 386         tz->last_temperature = tz->temperature;
 387         tz->temperature = temp;
 388
 389         trace_thermal_temperature(tz);
 390
 391         thermal_genl_sampling_temp(tz->id, temp);
 392 }
 393
 394 static void thermal_zone_device_init(struct thermal_zone_device *tz)
 395 {
 396         struct thermal_instance *pos;
 397         tz->temperature = THERMAL_TEMP_INVALID;
 398         tz->prev_low_trip = -INT_MAX;
 399         tz->prev_high_trip = INT_MAX;
 400         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 401                 pos->initialized = false;
 402 }
 403
 404 void __thermal_zone_device_update(struct thermal_zone_device *tz,
 405                                   enum thermal_notify_event event)
 406 {
 407         int count;
 408
 409         if (atomic_read(&in_suspend))
 410                 return;
 411
 412         if (WARN_ONCE(!tz->ops->get_temp,
 413                       "'%s' must not be called without 'get_temp' ops set\n",
 414                       __func__))
 415                 return;
 416
 417         if (!thermal_zone_device_is_enabled(tz))
 418                 return;
 419
 420         update_temperature(tz);
 421
 422         __thermal_zone_set_trips(tz);
 423
 424         tz->notify_event = event;
 425
 426         for (count = 0; count < tz->num_trips; count++)
 427                 handle_thermal_trip(tz, count);
 428
 429         monitor_thermal_zone(tz);
 430 }
 431
 432 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 433                                         enum thermal_device_mode mode)
 434 {
 435         int ret = 0;
 436
 437         mutex_lock(&tz->lock);
 438
 439         /* do nothing if mode isn't changing */
 440         if (mode == tz->mode) {
 441                 mutex_unlock(&tz->lock);
 442
 443                 return ret;
 444         }
 445
 446         if (!device_is_registered(&tz->device)) {
 447                 mutex_unlock(&tz->lock);
 448
 449                 return -ENODEV;
 450         }
 451
 452         if (tz->ops->change_mode)
 453                 ret = tz->ops->change_mode(tz, mode);
 454
 455         if (!ret)
 456                 tz->mode = mode;
 457
 458         __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 459
 460         mutex_unlock(&tz->lock);
 461
 462         if (mode == THERMAL_DEVICE_ENABLED)
 463                 thermal_notify_tz_enable(tz->id);
 464         else
 465                 thermal_notify_tz_disable(tz->id);
 466
 467         return ret;
 468 }
 469
 470 int thermal_zone_device_enable(struct thermal_zone_device *tz)
 471 {
 472         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
 473 }
 474 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
 475
 476 int thermal_zone_device_disable(struct thermal_zone_device *tz)
 477 {
 478         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 479 }
 480 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 481
 482 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
 483 {
 484         lockdep_assert_held(&tz->lock);
 485
 486         return tz->mode == THERMAL_DEVICE_ENABLED;
 487 }
 488
 489 void thermal_zone_device_update(struct thermal_zone_device *tz,
 490                                 enum thermal_notify_event event)
 491 {
 492         mutex_lock(&tz->lock);
 493         if (device_is_registered(&tz->device))
 494                 __thermal_zone_device_update(tz, event);
 495         mutex_unlock(&tz->lock);
 496 }
 497 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 498
 499 static void thermal_zone_device_check(struct work_struct *work)
 500 {
 501         struct thermal_zone_device *tz = container_of(work, struct
 502                                                       thermal_zone_device,
 503                                                       poll_queue.work);
 504         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 505 }
 506
 507 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 508                               void *data)
 509 {
 510         struct thermal_governor *gov;
 511         int ret = 0;
 512
 513         mutex_lock(&thermal_governor_lock);
 514         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 515                 ret = cb(gov, data);
 516                 if (ret)
 517                         break;
 518         }
 519         mutex_unlock(&thermal_governor_lock);
 520
 521         return ret;
 522 }
 523
 524 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 525                                               void *), void *data)
 526 {
 527         struct thermal_cooling_device *cdev;
 528         int ret = 0;
 529
 530         mutex_lock(&thermal_list_lock);
 531         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 532                 ret = cb(cdev, data);
 533                 if (ret)
 534                         break;
 535         }
 536         mutex_unlock(&thermal_list_lock);
 537
 538         return ret;
 539 }
 540
 541 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 542                           void *data)
 543 {
 544         struct thermal_zone_device *tz;
 545         int ret = 0;
 546
 547         mutex_lock(&thermal_list_lock);
 548         list_for_each_entry(tz, &thermal_tz_list, node) {
 549                 ret = cb(tz, data);
 550                 if (ret)
 551                         break;
 552         }
 553         mutex_unlock(&thermal_list_lock);
 554
 555         return ret;
 556 }
 557
 558 struct thermal_zone_device *thermal_zone_get_by_id(int id)
 559 {
 560         struct thermal_zone_device *tz, *match = NULL;
 561
 562         mutex_lock(&thermal_list_lock);
 563         list_for_each_entry(tz, &thermal_tz_list, node) {
 564                 if (tz->id == id) {
 565                         match = tz;
 566                         break;
 567                 }
 568         }
 569         mutex_unlock(&thermal_list_lock);
 570
 571         return match;
 572 }
 573
 574 /*
 575  * Device management section: cooling devices, zones devices, and binding
 576  *
 577  * Set of functions provided by the thermal core for:
 578  * - cooling devices lifecycle: registration, unregistration,
 579  *                              binding, and unbinding.
 580  * - thermal zone devices lifecycle: registration, unregistration,
 581  *                                   binding, and unbinding.
 582  */
 583
 584 /**
 585  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 586  * @tz:         pointer to struct thermal_zone_device
 587  * @trip:       indicates which trip point the cooling devices is
 588  *              associated with in this thermal zone.
 589  * @cdev:       pointer to struct thermal_cooling_device
 590  * @upper:      the Maximum cooling state for this trip point.
 591  *              THERMAL_NO_LIMIT means no upper limit,
 592  *              and the cooling device can be in max_state.
 593  * @lower:      the Minimum cooling state can be used for this trip point.
 594  *              THERMAL_NO_LIMIT means no lower limit,
 595  *              and the cooling device can be in cooling state 0.
 596  * @weight:     The weight of the cooling device to be bound to the
 597  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 598  *              default value
 599  *
 600  * This interface function bind a thermal cooling device to the certain trip
 601  * point of a thermal zone device.
 602  * This function is usually called in the thermal zone device .bind callback.
 603  *
 604  * Return: 0 on success, the proper error value otherwise.
 605  */
 606 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 607                                      int trip,
 608                                      struct thermal_cooling_device *cdev,
 609                                      unsigned long upper, unsigned long lower,
 610                                      unsigned int weight)
 611 {
 612         struct thermal_instance *dev;
 613         struct thermal_instance *pos;
 614         struct thermal_zone_device *pos1;
 615         struct thermal_cooling_device *pos2;
 616         bool upper_no_limit;
 617         int result;
 618
 619         if (trip >= tz->num_trips || trip < 0)
 620                 return -EINVAL;
 621
 622         list_for_each_entry(pos1, &thermal_tz_list, node) {
 623                 if (pos1 == tz)
 624                         break;
 625         }
 626         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 627                 if (pos2 == cdev)
 628                         break;
 629         }
 630
 631         if (tz != pos1 || cdev != pos2)
 632                 return -EINVAL;
 633
 634         /* lower default 0, upper default max_state */
 635         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 636
 637         if (upper == THERMAL_NO_LIMIT) {
 638                 upper = cdev->max_state;
 639                 upper_no_limit = true;
 640         } else {
 641                 upper_no_limit = false;
 642         }
 643
 644         if (lower > upper || upper > cdev->max_state)
 645                 return -EINVAL;
 646
 647         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 648         if (!dev)
 649                 return -ENOMEM;
 650         dev->tz = tz;
 651         dev->cdev = cdev;
 652         dev->trip = trip;
 653         dev->upper = upper;
 654         dev->upper_no_limit = upper_no_limit;
 655         dev->lower = lower;
 656         dev->target = THERMAL_NO_TARGET;
 657         dev->weight = weight;
 658
 659         result = ida_alloc(&tz->ida, GFP_KERNEL);
 660         if (result < 0)
 661                 goto free_mem;
 662
 663         dev->id = result;
 664         sprintf(dev->name, "cdev%d", dev->id);
 665         result =
 666             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 667         if (result)
 668                 goto release_ida;
 669
 670         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 671         sysfs_attr_init(&dev->attr.attr);
 672         dev->attr.attr.name = dev->attr_name;
 673         dev->attr.attr.mode = 0444;
 674         dev->attr.show = trip_point_show;
 675         result = device_create_file(&tz->device, &dev->attr);
 676         if (result)
 677                 goto remove_symbol_link;
 678
 679         sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
 680         sysfs_attr_init(&dev->weight_attr.attr);
 681         dev->weight_attr.attr.name = dev->weight_attr_name;
 682         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 683         dev->weight_attr.show = weight_show;
 684         dev->weight_attr.store = weight_store;
 685         result = device_create_file(&tz->device, &dev->weight_attr);
 686         if (result)
 687                 goto remove_trip_file;
 688
 689         mutex_lock(&tz->lock);
 690         mutex_lock(&cdev->lock);
 691         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 692                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 693                         result = -EEXIST;
 694                         break;
 695                 }
 696         if (!result) {
 697                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 698                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 699                 atomic_set(&tz->need_update, 1);
 700         }
 701         mutex_unlock(&cdev->lock);
 702         mutex_unlock(&tz->lock);
 703
 704         if (!result)
 705                 return 0;
 706
 707         device_remove_file(&tz->device, &dev->weight_attr);
 708 remove_trip_file:
 709         device_remove_file(&tz->device, &dev->attr);
 710 remove_symbol_link:
 711         sysfs_remove_link(&tz->device.kobj, dev->name);
 712 release_ida:
 713         ida_free(&tz->ida, dev->id);
 714 free_mem:
 715         kfree(dev);
 716         return result;
 717 }
 718 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 719
 720 /**
 721  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 722  *                                        thermal zone.
 723  * @tz:         pointer to a struct thermal_zone_device.
 724  * @trip:       indicates which trip point the cooling devices is
 725  *              associated with in this thermal zone.
 726  * @cdev:       pointer to a struct thermal_cooling_device.
 727  *
 728  * This interface function unbind a thermal cooling device from the certain
 729  * trip point of a thermal zone device.
 730  * This function is usually called in the thermal zone device .unbind callback.
 731  *
 732  * Return: 0 on success, the proper error value otherwise.
 733  */
 734 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 735                                        int trip,
 736                                        struct thermal_cooling_device *cdev)
 737 {
 738         struct thermal_instance *pos, *next;
 739
 740         mutex_lock(&tz->lock);
 741         mutex_lock(&cdev->lock);
 742         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 743                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 744                         list_del(&pos->tz_node);
 745                         list_del(&pos->cdev_node);
 746                         mutex_unlock(&cdev->lock);
 747                         mutex_unlock(&tz->lock);
 748                         goto unbind;
 749                 }
 750         }
 751         mutex_unlock(&cdev->lock);
 752         mutex_unlock(&tz->lock);
 753
 754         return -ENODEV;
 755
 756 unbind:
 757         device_remove_file(&tz->device, &pos->weight_attr);
 758         device_remove_file(&tz->device, &pos->attr);
 759         sysfs_remove_link(&tz->device.kobj, pos->name);
 760         ida_free(&tz->ida, pos->id);
 761         kfree(pos);
 762         return 0;
 763 }
 764 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 765
 766 static void thermal_release(struct device *dev)
 767 {
 768         struct thermal_zone_device *tz;
 769         struct thermal_cooling_device *cdev;
 770
 771         if (!strncmp(dev_name(dev), "thermal_zone",
 772                      sizeof("thermal_zone") - 1)) {
 773                 tz = to_thermal_zone(dev);
 774                 thermal_zone_destroy_device_groups(tz);
 775                 mutex_destroy(&tz->lock);
 776                 kfree(tz);
 777         } else if (!strncmp(dev_name(dev), "cooling_device",
 778                             sizeof("cooling_device") - 1)) {
 779                 cdev = to_cooling_device(dev);
 780                 thermal_cooling_device_destroy_sysfs(cdev);
 781                 kfree(cdev->type);
 782                 ida_free(&thermal_cdev_ida, cdev->id);
 783                 kfree(cdev);
 784         }
 785 }
 786
 787 static struct class *thermal_class;
 788
 789 static inline
 790 void print_bind_err_msg(struct thermal_zone_device *tz,
 791                         struct thermal_cooling_device *cdev, int ret)
 792 {
 793         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
 794                 tz->type, cdev->type, ret);
 795 }
 796
 797 static void bind_cdev(struct thermal_cooling_device *cdev)
 798 {
 799         int ret;
 800         struct thermal_zone_device *pos = NULL;
 801
 802         list_for_each_entry(pos, &thermal_tz_list, node) {
 803                 if (pos->ops->bind) {
 804                         ret = pos->ops->bind(pos, cdev);
 805                         if (ret)
 806                                 print_bind_err_msg(pos, cdev, ret);
 807                 }
 808         }
 809 }
 810
 811 /**
 812  * __thermal_cooling_device_register() - register a new thermal cooling device
 813  * @np:         a pointer to a device tree node.
 814  * @type:       the thermal cooling device type.
 815  * @devdata:    device private data.
 816  * @ops:                standard thermal cooling devices callbacks.
 817  *
 818  * This interface function adds a new thermal cooling device (fan/processor/...)
 819  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 820  * to all the thermal zone devices registered at the same time.
 821  * It also gives the opportunity to link the cooling device to a device tree
 822  * node, so that it can be bound to a thermal zone created out of device tree.
 823  *
 824  * Return: a pointer to the created struct thermal_cooling_device or an
 825  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 826  */
 827 static struct thermal_cooling_device *
 828 __thermal_cooling_device_register(struct device_node *np,
 829                                   const char *type, void *devdata,
 830                                   const struct thermal_cooling_device_ops *ops)
 831 {
 832         struct thermal_cooling_device *cdev;
 833         struct thermal_zone_device *pos = NULL;
 834         int id, ret;
 835
 836         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
 837             !ops->set_cur_state)
 838                 return ERR_PTR(-EINVAL);
 839
 840         if (!thermal_class)
 841                 return ERR_PTR(-ENODEV);
 842
 843         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 844         if (!cdev)
 845                 return ERR_PTR(-ENOMEM);
 846
 847         ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
 848         if (ret < 0)
 849                 goto out_kfree_cdev;
 850         cdev->id = ret;
 851         id = ret;
 852
 853         cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
 854         if (!cdev->type) {
 855                 ret = -ENOMEM;
 856                 goto out_ida_remove;
 857         }
 858
 859         mutex_init(&cdev->lock);
 860         INIT_LIST_HEAD(&cdev->thermal_instances);
 861         cdev->np = np;
 862         cdev->ops = ops;
 863         cdev->updated = false;
 864         cdev->device.class = thermal_class;
 865         cdev->devdata = devdata;
 866
 867         ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
 868         if (ret)
 869                 goto out_cdev_type;
 870
 871         thermal_cooling_device_setup_sysfs(cdev);
 872
 873         ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
 874         if (ret)
 875                 goto out_cooling_dev;
 876
 877         ret = device_register(&cdev->device);
 878         if (ret) {
 879                 /* thermal_release() handles rest of the cleanup */
 880                 put_device(&cdev->device);
 881                 return ERR_PTR(ret);
 882         }
 883
 884         /* Add 'this' new cdev to the global cdev list */
 885         mutex_lock(&thermal_list_lock);
 886
 887         list_add(&cdev->node, &thermal_cdev_list);
 888
 889         /* Update binding information for 'this' new cdev */
 890         bind_cdev(cdev);
 891
 892         list_for_each_entry(pos, &thermal_tz_list, node)
 893                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
 894                         thermal_zone_device_update(pos,
 895                                                    THERMAL_EVENT_UNSPECIFIED);
 896
 897         mutex_unlock(&thermal_list_lock);
 898
 899         return cdev;
 900
 901 out_cooling_dev:
 902         thermal_cooling_device_destroy_sysfs(cdev);
 903 out_cdev_type:
 904         kfree(cdev->type);
 905 out_ida_remove:
 906         ida_free(&thermal_cdev_ida, id);
 907 out_kfree_cdev:
 908         kfree(cdev);
 909         return ERR_PTR(ret);
 910 }
 911
 912 /**
 913  * thermal_cooling_device_register() - register a new thermal cooling device
 914  * @type:       the thermal cooling device type.
 915  * @devdata:    device private data.
 916  * @ops:                standard thermal cooling devices callbacks.
 917  *
 918  * This interface function adds a new thermal cooling device (fan/processor/...)
 919  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 920  * to all the thermal zone devices registered at the same time.
 921  *
 922  * Return: a pointer to the created struct thermal_cooling_device or an
 923  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 924  */
 925 struct thermal_cooling_device *
 926 thermal_cooling_device_register(const char *type, void *devdata,
 927                                 const struct thermal_cooling_device_ops *ops)
 928 {
 929         return __thermal_cooling_device_register(NULL, type, devdata, ops);
 930 }
 931 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
 932
 933 /**
 934  * thermal_of_cooling_device_register() - register an OF thermal cooling device
 935  * @np:         a pointer to a device tree node.
 936  * @type:       the thermal cooling device type.
 937  * @devdata:    device private data.
 938  * @ops:                standard thermal cooling devices callbacks.
 939  *
 940  * This function will register a cooling device with device tree node reference.
 941  * This interface function adds a new thermal cooling device (fan/processor/...)
 942  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 943  * to all the thermal zone devices registered at the same time.
 944  *
 945  * Return: a pointer to the created struct thermal_cooling_device or an
 946  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 947  */
 948 struct thermal_cooling_device *
 949 thermal_of_cooling_device_register(struct device_node *np,
 950                                    const char *type, void *devdata,
 951                                    const struct thermal_cooling_device_ops *ops)
 952 {
 953         return __thermal_cooling_device_register(np, type, devdata, ops);
 954 }
 955 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
 956
 957 static void thermal_cooling_device_release(struct device *dev, void *res)
 958 {
 959         thermal_cooling_device_unregister(
 960                                 *(struct thermal_cooling_device **)res);
 961 }
 962
 963 /**
 964  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
 965  *                                             device
 966  * @dev:        a valid struct device pointer of a sensor device.
 967  * @np:         a pointer to a device tree node.
 968  * @type:       the thermal cooling device type.
 969  * @devdata:    device private data.
 970  * @ops:        standard thermal cooling devices callbacks.
 971  *
 972  * This function will register a cooling device with device tree node reference.
 973  * This interface function adds a new thermal cooling device (fan/processor/...)
 974  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 975  * to all the thermal zone devices registered at the same time.
 976  *
 977  * Return: a pointer to the created struct thermal_cooling_device or an
 978  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 979  */
 980 struct thermal_cooling_device *
 981 devm_thermal_of_cooling_device_register(struct device *dev,
 982                                 struct device_node *np,
 983                                 char *type, void *devdata,
 984                                 const struct thermal_cooling_device_ops *ops)
 985 {
 986         struct thermal_cooling_device **ptr, *tcd;
 987
 988         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
 989                            GFP_KERNEL);
 990         if (!ptr)
 991                 return ERR_PTR(-ENOMEM);
 992
 993         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
 994         if (IS_ERR(tcd)) {
 995                 devres_free(ptr);
 996                 return tcd;
 997         }
 998
 999         *ptr = tcd;
1000         devres_add(dev, ptr);
1001
1002         return tcd;
1003 }
1004 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1005
1006 static bool thermal_cooling_device_present(struct thermal_cooling_device *cdev)
1007 {
1008         struct thermal_cooling_device *pos = NULL;
1009
1010         list_for_each_entry(pos, &thermal_cdev_list, node) {
1011                 if (pos == cdev)
1012                         return true;
1013         }
1014
1015         return false;
1016 }
1017
1018 /**
1019  * thermal_cooling_device_update - Update a cooling device object
1020  * @cdev: Target cooling device.
1021  *
1022  * Update @cdev to reflect a change of the underlying hardware or platform.
1023  *
1024  * Must be called when the maximum cooling state of @cdev becomes invalid and so
1025  * its .get_max_state() callback needs to be run to produce the new maximum
1026  * cooling state value.
1027  */
1028 void thermal_cooling_device_update(struct thermal_cooling_device *cdev)
1029 {
1030         struct thermal_instance *ti;
1031         unsigned long state;
1032
1033         if (IS_ERR_OR_NULL(cdev))
1034                 return;
1035
1036         /*
1037          * Hold thermal_list_lock throughout the update to prevent the device
1038          * from going away while being updated.
1039          */
1040         mutex_lock(&thermal_list_lock);
1041
1042         if (!thermal_cooling_device_present(cdev))
1043                 goto unlock_list;
1044
1045         /*
1046          * Update under the cdev lock to prevent the state from being set beyond
1047          * the new limit concurrently.
1048          */
1049         mutex_lock(&cdev->lock);
1050
1051         if (cdev->ops->get_max_state(cdev, &cdev->max_state))
1052                 goto unlock;
1053
1054         thermal_cooling_device_stats_reinit(cdev);
1055
1056         list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) {
1057                 if (ti->upper == cdev->max_state)
1058                         continue;
1059
1060                 if (ti->upper < cdev->max_state) {
1061                         if (ti->upper_no_limit)
1062                                 ti->upper = cdev->max_state;
1063
1064                         continue;
1065                 }
1066
1067                 ti->upper = cdev->max_state;
1068                 if (ti->lower > ti->upper)
1069                         ti->lower = ti->upper;
1070
1071                 if (ti->target == THERMAL_NO_TARGET)
1072                         continue;
1073
1074                 if (ti->target > ti->upper)
1075                         ti->target = ti->upper;
1076         }
1077
1078         if (cdev->ops->get_cur_state(cdev, &state) || state > cdev->max_state)
1079                 goto unlock;
1080
1081         thermal_cooling_device_stats_update(cdev, state);
1082
1083 unlock:
1084         mutex_unlock(&cdev->lock);
1085
1086 unlock_list:
1087         mutex_unlock(&thermal_list_lock);
1088 }
1089 EXPORT_SYMBOL_GPL(thermal_cooling_device_update);
1090
1091 /**
1092  * thermal_cooling_device_unregister - removes a thermal cooling device
1093  * @cdev:       the thermal cooling device to remove.
1094  *
1095  * thermal_cooling_device_unregister() must be called when a registered
1096  * thermal cooling device is no longer needed.
1097  */
1098 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1099 {
1100         struct thermal_zone_device *tz;
1101
1102         if (!cdev)
1103                 return;
1104
1105         mutex_lock(&thermal_list_lock);
1106
1107         if (!thermal_cooling_device_present(cdev)) {
1108                 mutex_unlock(&thermal_list_lock);
1109                 return;
1110         }
1111
1112         list_del(&cdev->node);
1113
1114         /* Unbind all thermal zones associated with 'this' cdev */
1115         list_for_each_entry(tz, &thermal_tz_list, node) {
1116                 if (tz->ops->unbind)
1117                         tz->ops->unbind(tz, cdev);
1118         }
1119
1120         mutex_unlock(&thermal_list_lock);
1121
1122         device_unregister(&cdev->device);
1123 }
1124 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1125
1126 static void bind_tz(struct thermal_zone_device *tz)
1127 {
1128         int ret;
1129         struct thermal_cooling_device *pos = NULL;
1130
1131         if (!tz->ops->bind)
1132                 return;
1133
1134         mutex_lock(&thermal_list_lock);
1135
1136         list_for_each_entry(pos, &thermal_cdev_list, node) {
1137                 ret = tz->ops->bind(tz, pos);
1138                 if (ret)
1139                         print_bind_err_msg(tz, pos, ret);
1140         }
1141
1142         mutex_unlock(&thermal_list_lock);
1143 }
1144
1145 static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
1146 {
1147         *delay_jiffies = msecs_to_jiffies(delay_ms);
1148         if (delay_ms > 1000)
1149                 *delay_jiffies = round_jiffies(*delay_jiffies);
1150 }
1151
1152 int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
1153 {
1154         int i, ret = -EINVAL;
1155
1156         if (tz->ops->get_crit_temp)
1157                 return tz->ops->get_crit_temp(tz, temp);
1158
1159         if (!tz->trips)
1160                 return -EINVAL;
1161
1162         mutex_lock(&tz->lock);
1163
1164         for (i = 0; i < tz->num_trips; i++) {
1165                 if (tz->trips[i].type == THERMAL_TRIP_CRITICAL) {
1166                         *temp = tz->trips[i].temperature;
1167                         ret = 0;
1168                         break;
1169                 }
1170         }
1171
1172         mutex_unlock(&tz->lock);
1173
1174         return ret;
1175 }
1176 EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
1177
1178 /**
1179  * thermal_zone_device_register_with_trips() - register a new thermal zone device
1180  * @type:       the thermal zone device type
1181  * @trips:      a pointer to an array of thermal trips
1182  * @num_trips:  the number of trip points the thermal zone support
1183  * @mask:       a bit string indicating the writeablility of trip points
1184  * @devdata:    private device data
1185  * @ops:        standard thermal zone device callbacks
1186  * @tzp:        thermal zone platform parameters
1187  * @passive_delay: number of milliseconds to wait between polls when
1188  *                 performing passive cooling
1189  * @polling_delay: number of milliseconds to wait between polls when checking
1190  *                 whether trip points have been crossed (0 for interrupt
1191  *                 driven systems)
1192  *
1193  * This interface function adds a new thermal zone device (sensor) to
1194  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1195  * thermal cooling devices registered at the same time.
1196  * thermal_zone_device_unregister() must be called when the device is no
1197  * longer needed. The passive cooling depends on the .get_trend() return value.
1198  *
1199  * Return: a pointer to the created struct thermal_zone_device or an
1200  * in case of error, an ERR_PTR. Caller must check return value with
1201  * IS_ERR*() helpers.
1202  */
1203 struct thermal_zone_device *
1204 thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *trips, int num_trips, int mask,
1205                                         void *devdata, struct thermal_zone_device_ops *ops,
1206                                         struct thermal_zone_params *tzp, int passive_delay,
1207                                         int polling_delay)
1208 {
1209         struct thermal_zone_device *tz;
1210         int id;
1211         int result;
1212         int count;
1213         struct thermal_governor *governor;
1214
1215         if (!type || strlen(type) == 0) {
1216                 pr_err("No thermal zone type defined\n");
1217                 return ERR_PTR(-EINVAL);
1218         }
1219
1220         if (strlen(type) >= THERMAL_NAME_LENGTH) {
1221                 pr_err("Thermal zone name (%s) too long, should be under %d chars\n",
1222                        type, THERMAL_NAME_LENGTH);
1223                 return ERR_PTR(-EINVAL);
1224         }
1225
1226         /*
1227          * Max trip count can't exceed 31 as the "mask >> num_trips" condition.
1228          * For example, shifting by 32 will result in compiler warning:
1229          * warning: right shift count >= width of type [-Wshift-count- overflow]
1230          *
1231          * Also "mask >> num_trips" will always be true with 32 bit shift.
1232          * E.g. mask = 0x80000000 for trip id 31 to be RW. Then
1233          * mask >> 32 = 0x80000000
1234          * This will result in failure for the below condition.
1235          *
1236          * Check will be true when the bit 31 of the mask is set.
1237          * 32 bit shift will cause overflow of 4 byte integer.
1238          */
1239         if (num_trips > (BITS_PER_TYPE(int) - 1) || num_trips < 0 || mask >> num_trips) {
1240                 pr_err("Incorrect number of thermal trips\n");
1241                 return ERR_PTR(-EINVAL);
1242         }
1243
1244         if (!ops) {
1245                 pr_err("Thermal zone device ops not defined\n");
1246                 return ERR_PTR(-EINVAL);
1247         }
1248
1249         if (num_trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp) && !trips)
1250                 return ERR_PTR(-EINVAL);
1251
1252         if (!thermal_class)
1253                 return ERR_PTR(-ENODEV);
1254
1255         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1256         if (!tz)
1257                 return ERR_PTR(-ENOMEM);
1258
1259         if (tzp) {
1260                 tz->tzp = kmemdup(tzp, sizeof(*tzp), GFP_KERNEL);
1261                 if (!tz->tzp) {
1262                         result = -ENOMEM;
1263                         goto free_tz;
1264                 }
1265         }
1266
1267         INIT_LIST_HEAD(&tz->thermal_instances);
1268         ida_init(&tz->ida);
1269         mutex_init(&tz->lock);
1270         id = ida_alloc(&thermal_tz_ida, GFP_KERNEL);
1271         if (id < 0) {
1272                 result = id;
1273                 goto free_tzp;
1274         }
1275
1276         tz->id = id;
1277         strscpy(tz->type, type, sizeof(tz->type));
1278
1279         if (!ops->critical)
1280                 ops->critical = thermal_zone_device_critical;
1281
1282         tz->ops = ops;
1283         tz->device.class = thermal_class;
1284         tz->devdata = devdata;
1285         tz->trips = trips;
1286         tz->num_trips = num_trips;
1287
1288         thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1289         thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1290
1291         /* sys I/F */
1292         /* Add nodes that are always present via .groups */
1293         result = thermal_zone_create_device_groups(tz, mask);
1294         if (result)
1295                 goto remove_id;
1296
1297         /* A new thermal zone needs to be updated anyway. */
1298         atomic_set(&tz->need_update, 1);
1299
1300         result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1301         if (result) {
1302                 thermal_zone_destroy_device_groups(tz);
1303                 goto remove_id;
1304         }
1305         result = device_register(&tz->device);
1306         if (result)
1307                 goto release_device;
1308
1309         for (count = 0; count < num_trips; count++) {
1310                 struct thermal_trip trip;
1311
1312                 result = thermal_zone_get_trip(tz, count, &trip);
1313                 if (result || !trip.temperature)
1314                         set_bit(count, &tz->trips_disabled);
1315         }
1316
1317         /* Update 'this' zone's governor information */
1318         mutex_lock(&thermal_governor_lock);
1319
1320         if (tz->tzp)
1321                 governor = __find_governor(tz->tzp->governor_name);
1322         else
1323                 governor = def_governor;
1324
1325         result = thermal_set_governor(tz, governor);
1326         if (result) {
1327                 mutex_unlock(&thermal_governor_lock);
1328                 goto unregister;
1329         }
1330
1331         mutex_unlock(&thermal_governor_lock);
1332
1333         if (!tz->tzp || !tz->tzp->no_hwmon) {
1334                 result = thermal_add_hwmon_sysfs(tz);
1335                 if (result)
1336                         goto unregister;
1337         }
1338
1339         mutex_lock(&thermal_list_lock);
1340         list_add_tail(&tz->node, &thermal_tz_list);
1341         mutex_unlock(&thermal_list_lock);
1342
1343         /* Bind cooling devices for this zone */
1344         bind_tz(tz);
1345
1346         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1347
1348         thermal_zone_device_init(tz);
1349         /* Update the new thermal zone and mark it as already updated. */
1350         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1351                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1352
1353         thermal_notify_tz_create(tz->id, tz->type);
1354
1355         return tz;
1356
1357 unregister:
1358         device_del(&tz->device);
1359 release_device:
1360         put_device(&tz->device);
1361         tz = NULL;
1362 remove_id:
1363         ida_free(&thermal_tz_ida, id);
1364 free_tzp:
1365         kfree(tz->tzp);
1366 free_tz:
1367         kfree(tz);
1368         return ERR_PTR(result);
1369 }
1370 EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);
1371
1372 struct thermal_zone_device *thermal_zone_device_register(const char *type, int ntrips, int mask,
1373                                                          void *devdata, struct thermal_zone_device_ops *ops,
1374                                                          struct thermal_zone_params *tzp, int passive_delay,
1375                                                          int polling_delay)
1376 {
1377         return thermal_zone_device_register_with_trips(type, NULL, ntrips, mask,
1378                                                        devdata, ops, tzp,
1379                                                        passive_delay, polling_delay);
1380 }
1381 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1382
1383 void *thermal_zone_device_priv(struct thermal_zone_device *tzd)
1384 {
1385         return tzd->devdata;
1386 }
1387 EXPORT_SYMBOL_GPL(thermal_zone_device_priv);
1388
1389 const char *thermal_zone_device_type(struct thermal_zone_device *tzd)
1390 {
1391         return tzd->type;
1392 }
1393 EXPORT_SYMBOL_GPL(thermal_zone_device_type);
1394
1395 int thermal_zone_device_id(struct thermal_zone_device *tzd)
1396 {
1397         return tzd->id;
1398 }
1399 EXPORT_SYMBOL_GPL(thermal_zone_device_id);
1400
1401 struct device *thermal_zone_device(struct thermal_zone_device *tzd)
1402 {
1403         return &tzd->device;
1404 }
1405 EXPORT_SYMBOL_GPL(thermal_zone_device);
1406
1407 /**
1408  * thermal_zone_device_unregister - removes the registered thermal zone device
1409  * @tz: the thermal zone device to remove
1410  */
1411 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1412 {
1413         int tz_id;
1414         struct thermal_cooling_device *cdev;
1415         struct thermal_zone_device *pos = NULL;
1416
1417         if (!tz)
1418                 return;
1419
1420         tz_id = tz->id;
1421
1422         mutex_lock(&thermal_list_lock);
1423         list_for_each_entry(pos, &thermal_tz_list, node)
1424                 if (pos == tz)
1425                         break;
1426         if (pos != tz) {
1427                 /* thermal zone device not found */
1428                 mutex_unlock(&thermal_list_lock);
1429                 return;
1430         }
1431         list_del(&tz->node);
1432
1433         /* Unbind all cdevs associated with 'this' thermal zone */
1434         list_for_each_entry(cdev, &thermal_cdev_list, node)
1435                 if (tz->ops->unbind)
1436                         tz->ops->unbind(tz, cdev);
1437
1438         mutex_unlock(&thermal_list_lock);
1439
1440         cancel_delayed_work_sync(&tz->poll_queue);
1441
1442         thermal_set_governor(tz, NULL);
1443
1444         thermal_remove_hwmon_sysfs(tz);
1445         ida_free(&thermal_tz_ida, tz->id);
1446         ida_destroy(&tz->ida);
1447
1448         mutex_lock(&tz->lock);
1449         device_del(&tz->device);
1450         mutex_unlock(&tz->lock);
1451
1452         kfree(tz->tzp);
1453
1454         put_device(&tz->device);
1455
1456         thermal_notify_tz_delete(tz_id);
1457 }
1458 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1459
1460 /**
1461  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1462  * @name: thermal zone name to fetch the temperature
1463  *
1464  * When only one zone is found with the passed name, returns a reference to it.
1465  *
1466  * Return: On success returns a reference to an unique thermal zone with
1467  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1468  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1469  */
1470 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1471 {
1472         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1473         unsigned int found = 0;
1474
1475         if (!name)
1476                 goto exit;
1477
1478         mutex_lock(&thermal_list_lock);
1479         list_for_each_entry(pos, &thermal_tz_list, node)
1480                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1481                         found++;
1482                         ref = pos;
1483                 }
1484         mutex_unlock(&thermal_list_lock);
1485
1486         /* nothing has been found, thus an error code for it */
1487         if (found == 0)
1488                 ref = ERR_PTR(-ENODEV);
1489         else if (found > 1)
1490         /* Success only when an unique zone is found */
1491                 ref = ERR_PTR(-EEXIST);
1492
1493 exit:
1494         return ref;
1495 }
1496 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1497
1498 static int thermal_pm_notify(struct notifier_block *nb,
1499                              unsigned long mode, void *_unused)
1500 {
1501         struct thermal_zone_device *tz;
1502
1503         switch (mode) {
1504         case PM_HIBERNATION_PREPARE:
1505         case PM_RESTORE_PREPARE:
1506         case PM_SUSPEND_PREPARE:
1507                 atomic_set(&in_suspend, 1);
1508                 break;
1509         case PM_POST_HIBERNATION:
1510         case PM_POST_RESTORE:
1511         case PM_POST_SUSPEND:
1512                 atomic_set(&in_suspend, 0);
1513                 list_for_each_entry(tz, &thermal_tz_list, node) {
1514                         thermal_zone_device_init(tz);
1515                         thermal_zone_device_update(tz,
1516                                                    THERMAL_EVENT_UNSPECIFIED);
1517                 }
1518                 break;
1519         default:
1520                 break;
1521         }
1522         return 0;
1523 }
1524
1525 static struct notifier_block thermal_pm_nb = {
1526         .notifier_call = thermal_pm_notify,
1527 };
1528
1529 static int __init thermal_init(void)
1530 {
1531         int result;
1532
1533         result = thermal_netlink_init();
1534         if (result)
1535                 goto error;
1536
1537         result = thermal_register_governors();
1538         if (result)
1539                 goto unregister_netlink;
1540
1541         thermal_class = kzalloc(sizeof(*thermal_class), GFP_KERNEL);
1542         if (!thermal_class) {
1543                 result = -ENOMEM;
1544                 goto unregister_governors;
1545         }
1546
1547         thermal_class->name = "thermal";
1548         thermal_class->dev_release = thermal_release;
1549
1550         result = class_register(thermal_class);
1551         if (result) {
1552                 kfree(thermal_class);
1553                 thermal_class = NULL;
1554                 goto unregister_governors;
1555         }
1556
1557         result = register_pm_notifier(&thermal_pm_nb);
1558         if (result)
1559                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1560                         result);
1561
1562         return 0;
1563
1564 unregister_governors:
1565         thermal_unregister_governors();
1566 unregister_netlink:
1567         thermal_netlink_exit();
1568 error:
1569         mutex_destroy(&thermal_list_lock);
1570         mutex_destroy(&thermal_governor_lock);
1571         return result;
1572 }
1573 postcore_initcall(thermal_init);