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 <[email protected]>
   7  *  Copyright (C) 2008 Sujith Thomas <[email protected]>
   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 <trace/events/thermal.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         gov = __find_governor(strim(policy));
 207         if (!gov)
 208                 goto exit;
 209
 210         ret = thermal_set_governor(tz, gov);
 211
 212 exit:
 213         mutex_unlock(&tz->lock);
 214         mutex_unlock(&thermal_governor_lock);
 215
 216         thermal_notify_tz_gov_change(tz->id, policy);
 217
 218         return ret;
 219 }
 220
 221 int thermal_build_list_of_policies(char *buf)
 222 {
 223         struct thermal_governor *pos;
 224         ssize_t count = 0;
 225
 226         mutex_lock(&thermal_governor_lock);
 227
 228         list_for_each_entry(pos, &thermal_governor_list, governor_list) {
 229                 count += scnprintf(buf + count, PAGE_SIZE - count, "%s ",
 230                                    pos->name);
 231         }
 232         count += scnprintf(buf + count, PAGE_SIZE - count, "\n");
 233
 234         mutex_unlock(&thermal_governor_lock);
 235
 236         return count;
 237 }
 238
 239 static void __init thermal_unregister_governors(void)
 240 {
 241         struct thermal_governor **governor;
 242
 243         for_each_governor_table(governor)
 244                 thermal_unregister_governor(*governor);
 245 }
 246
 247 static int __init thermal_register_governors(void)
 248 {
 249         int ret = 0;
 250         struct thermal_governor **governor;
 251
 252         for_each_governor_table(governor) {
 253                 ret = thermal_register_governor(*governor);
 254                 if (ret) {
 255                         pr_err("Failed to register governor: '%s'",
 256                                (*governor)->name);
 257                         break;
 258                 }
 259
 260                 pr_info("Registered thermal governor '%s'",
 261                         (*governor)->name);
 262         }
 263
 264         if (ret) {
 265                 struct thermal_governor **gov;
 266
 267                 for_each_governor_table(gov) {
 268                         if (gov == governor)
 269                                 break;
 270                         thermal_unregister_governor(*gov);
 271                 }
 272         }
 273
 274         return ret;
 275 }
 276
 277 /*
 278  * Zone update section: main control loop applied to each zone while monitoring
 279  *
 280  * in polling mode. The monitoring is done using a workqueue.
 281  * Same update may be done on a zone by calling thermal_zone_device_update().
 282  *
 283  * An update means:
 284  * - Non-critical trips will invoke the governor responsible for that zone;
 285  * - Hot trips will produce a notification to userspace;
 286  * - Critical trip point will cause a system shutdown.
 287  */
 288 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 289                                             unsigned long delay)
 290 {
 291         if (delay)
 292                 mod_delayed_work(system_freezable_power_efficient_wq,
 293                                  &tz->poll_queue, delay);
 294         else
 295                 cancel_delayed_work(&tz->poll_queue);
 296 }
 297
 298 static inline bool should_stop_polling(struct thermal_zone_device *tz)
 299 {
 300         return !thermal_zone_device_is_enabled(tz);
 301 }
 302
 303 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 304 {
 305         bool stop;
 306
 307         stop = should_stop_polling(tz);
 308
 309         mutex_lock(&tz->lock);
 310
 311         if (!stop && tz->passive)
 312                 thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
 313         else if (!stop && tz->polling_delay_jiffies)
 314                 thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
 315         else
 316                 thermal_zone_device_set_polling(tz, 0);
 317
 318         mutex_unlock(&tz->lock);
 319 }
 320
 321 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 322 {
 323         tz->governor ? tz->governor->throttle(tz, trip) :
 324                        def_governor->throttle(tz, trip);
 325 }
 326
 327 void thermal_zone_device_critical(struct thermal_zone_device *tz)
 328 {
 329         /*
 330          * poweroff_delay_ms must be a carefully profiled positive value.
 331          * Its a must for forced_emergency_poweroff_work to be scheduled.
 332          */
 333         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 334
 335         dev_emerg(&tz->device, "%s: critical temperature reached, "
 336                   "shutting down\n", tz->type);
 337
 338         hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
 339 }
 340 EXPORT_SYMBOL(thermal_zone_device_critical);
 341
 342 static void handle_critical_trips(struct thermal_zone_device *tz,
 343                                   int trip, enum thermal_trip_type trip_type)
 344 {
 345         int trip_temp;
 346
 347         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 348
 349         /* If we have not crossed the trip_temp, we do not care. */
 350         if (trip_temp <= 0 || tz->temperature < trip_temp)
 351                 return;
 352
 353         trace_thermal_zone_trip(tz, trip, trip_type);
 354
 355         if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
 356                 tz->ops->hot(tz);
 357         else if (trip_type == THERMAL_TRIP_CRITICAL)
 358                 tz->ops->critical(tz);
 359 }
 360
 361 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
 362 {
 363         enum thermal_trip_type type;
 364         int trip_temp, hyst = 0;
 365
 366         /* Ignore disabled trip points */
 367         if (test_bit(trip, &tz->trips_disabled))
 368                 return;
 369
 370         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 371         tz->ops->get_trip_type(tz, trip, &type);
 372         if (tz->ops->get_trip_hyst)
 373                 tz->ops->get_trip_hyst(tz, trip, &hyst);
 374
 375         if (tz->last_temperature != THERMAL_TEMP_INVALID) {
 376                 if (tz->last_temperature < trip_temp &&
 377                     tz->temperature >= trip_temp)
 378                         thermal_notify_tz_trip_up(tz->id, trip,
 379                                                   tz->temperature);
 380                 if (tz->last_temperature >= trip_temp &&
 381                     tz->temperature < (trip_temp - hyst))
 382                         thermal_notify_tz_trip_down(tz->id, trip,
 383                                                     tz->temperature);
 384         }
 385
 386         if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
 387                 handle_critical_trips(tz, trip, type);
 388         else
 389                 handle_non_critical_trips(tz, trip);
 390         /*
 391          * Alright, we handled this trip successfully.
 392          * So, start monitoring again.
 393          */
 394         monitor_thermal_zone(tz);
 395 }
 396
 397 static void update_temperature(struct thermal_zone_device *tz)
 398 {
 399         int temp, ret;
 400
 401         ret = thermal_zone_get_temp(tz, &temp);
 402         if (ret) {
 403                 if (ret != -EAGAIN)
 404                         dev_warn(&tz->device,
 405                                  "failed to read out thermal zone (%d)\n",
 406                                  ret);
 407                 return;
 408         }
 409
 410         mutex_lock(&tz->lock);
 411         tz->last_temperature = tz->temperature;
 412         tz->temperature = temp;
 413         mutex_unlock(&tz->lock);
 414
 415         trace_thermal_temperature(tz);
 416
 417         thermal_genl_sampling_temp(tz->id, temp);
 418 }
 419
 420 static void thermal_zone_device_init(struct thermal_zone_device *tz)
 421 {
 422         struct thermal_instance *pos;
 423         tz->temperature = THERMAL_TEMP_INVALID;
 424         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 425                 pos->initialized = false;
 426 }
 427
 428 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 429                                         enum thermal_device_mode mode)
 430 {
 431         int ret = 0;
 432
 433         mutex_lock(&tz->lock);
 434
 435         /* do nothing if mode isn't changing */
 436         if (mode == tz->mode) {
 437                 mutex_unlock(&tz->lock);
 438
 439                 return ret;
 440         }
 441
 442         if (tz->ops->change_mode)
 443                 ret = tz->ops->change_mode(tz, mode);
 444
 445         if (!ret)
 446                 tz->mode = mode;
 447
 448         mutex_unlock(&tz->lock);
 449
 450         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 451
 452         if (mode == THERMAL_DEVICE_ENABLED)
 453                 thermal_notify_tz_enable(tz->id);
 454         else
 455                 thermal_notify_tz_disable(tz->id);
 456
 457         return ret;
 458 }
 459
 460 int thermal_zone_device_enable(struct thermal_zone_device *tz)
 461 {
 462         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
 463 }
 464 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
 465
 466 int thermal_zone_device_disable(struct thermal_zone_device *tz)
 467 {
 468         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 469 }
 470 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 471
 472 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
 473 {
 474         enum thermal_device_mode mode;
 475
 476         mutex_lock(&tz->lock);
 477
 478         mode = tz->mode;
 479
 480         mutex_unlock(&tz->lock);
 481
 482         return mode == THERMAL_DEVICE_ENABLED;
 483 }
 484
 485 void thermal_zone_device_update(struct thermal_zone_device *tz,
 486                                 enum thermal_notify_event event)
 487 {
 488         int count;
 489
 490         if (should_stop_polling(tz))
 491                 return;
 492
 493         if (atomic_read(&in_suspend))
 494                 return;
 495
 496         if (WARN_ONCE(!tz->ops->get_temp, "'%s' must not be called without "
 497                       "'get_temp' ops set\n", __func__))
 498                 return;
 499
 500         update_temperature(tz);
 501
 502         thermal_zone_set_trips(tz);
 503
 504         tz->notify_event = event;
 505
 506         for (count = 0; count < tz->trips; count++)
 507                 handle_thermal_trip(tz, count);
 508 }
 509 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 510
 511 static void thermal_zone_device_check(struct work_struct *work)
 512 {
 513         struct thermal_zone_device *tz = container_of(work, struct
 514                                                       thermal_zone_device,
 515                                                       poll_queue.work);
 516         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 517 }
 518
 519 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 520                               void *data)
 521 {
 522         struct thermal_governor *gov;
 523         int ret = 0;
 524
 525         mutex_lock(&thermal_governor_lock);
 526         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 527                 ret = cb(gov, data);
 528                 if (ret)
 529                         break;
 530         }
 531         mutex_unlock(&thermal_governor_lock);
 532
 533         return ret;
 534 }
 535
 536 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 537                                               void *), void *data)
 538 {
 539         struct thermal_cooling_device *cdev;
 540         int ret = 0;
 541
 542         mutex_lock(&thermal_list_lock);
 543         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 544                 ret = cb(cdev, data);
 545                 if (ret)
 546                         break;
 547         }
 548         mutex_unlock(&thermal_list_lock);
 549
 550         return ret;
 551 }
 552
 553 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 554                           void *data)
 555 {
 556         struct thermal_zone_device *tz;
 557         int ret = 0;
 558
 559         mutex_lock(&thermal_list_lock);
 560         list_for_each_entry(tz, &thermal_tz_list, node) {
 561                 ret = cb(tz, data);
 562                 if (ret)
 563                         break;
 564         }
 565         mutex_unlock(&thermal_list_lock);
 566
 567         return ret;
 568 }
 569
 570 struct thermal_zone_device *thermal_zone_get_by_id(int id)
 571 {
 572         struct thermal_zone_device *tz, *match = NULL;
 573
 574         mutex_lock(&thermal_list_lock);
 575         list_for_each_entry(tz, &thermal_tz_list, node) {
 576                 if (tz->id == id) {
 577                         match = tz;
 578                         break;
 579                 }
 580         }
 581         mutex_unlock(&thermal_list_lock);
 582
 583         return match;
 584 }
 585
 586 /*
 587  * Device management section: cooling devices, zones devices, and binding
 588  *
 589  * Set of functions provided by the thermal core for:
 590  * - cooling devices lifecycle: registration, unregistration,
 591  *                              binding, and unbinding.
 592  * - thermal zone devices lifecycle: registration, unregistration,
 593  *                                   binding, and unbinding.
 594  */
 595
 596 /**
 597  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 598  * @tz:         pointer to struct thermal_zone_device
 599  * @trip:       indicates which trip point the cooling devices is
 600  *              associated with in this thermal zone.
 601  * @cdev:       pointer to struct thermal_cooling_device
 602  * @upper:      the Maximum cooling state for this trip point.
 603  *              THERMAL_NO_LIMIT means no upper limit,
 604  *              and the cooling device can be in max_state.
 605  * @lower:      the Minimum cooling state can be used for this trip point.
 606  *              THERMAL_NO_LIMIT means no lower limit,
 607  *              and the cooling device can be in cooling state 0.
 608  * @weight:     The weight of the cooling device to be bound to the
 609  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 610  *              default value
 611  *
 612  * This interface function bind a thermal cooling device to the certain trip
 613  * point of a thermal zone device.
 614  * This function is usually called in the thermal zone device .bind callback.
 615  *
 616  * Return: 0 on success, the proper error value otherwise.
 617  */
 618 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 619                                      int trip,
 620                                      struct thermal_cooling_device *cdev,
 621                                      unsigned long upper, unsigned long lower,
 622                                      unsigned int weight)
 623 {
 624         struct thermal_instance *dev;
 625         struct thermal_instance *pos;
 626         struct thermal_zone_device *pos1;
 627         struct thermal_cooling_device *pos2;
 628         unsigned long max_state;
 629         int result, ret;
 630
 631         if (trip >= tz->trips || trip < 0)
 632                 return -EINVAL;
 633
 634         list_for_each_entry(pos1, &thermal_tz_list, node) {
 635                 if (pos1 == tz)
 636                         break;
 637         }
 638         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 639                 if (pos2 == cdev)
 640                         break;
 641         }
 642
 643         if (tz != pos1 || cdev != pos2)
 644                 return -EINVAL;
 645
 646         ret = cdev->ops->get_max_state(cdev, &max_state);
 647         if (ret)
 648                 return ret;
 649
 650         /* lower default 0, upper default max_state */
 651         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 652         upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
 653
 654         if (lower > upper || upper > max_state)
 655                 return -EINVAL;
 656
 657         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 658         if (!dev)
 659                 return -ENOMEM;
 660         dev->tz = tz;
 661         dev->cdev = cdev;
 662         dev->trip = trip;
 663         dev->upper = upper;
 664         dev->lower = lower;
 665         dev->target = THERMAL_NO_TARGET;
 666         dev->weight = weight;
 667
 668         result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
 669         if (result < 0)
 670                 goto free_mem;
 671
 672         dev->id = result;
 673         sprintf(dev->name, "cdev%d", dev->id);
 674         result =
 675             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 676         if (result)
 677                 goto release_ida;
 678
 679         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 680         sysfs_attr_init(&dev->attr.attr);
 681         dev->attr.attr.name = dev->attr_name;
 682         dev->attr.attr.mode = 0444;
 683         dev->attr.show = trip_point_show;
 684         result = device_create_file(&tz->device, &dev->attr);
 685         if (result)
 686                 goto remove_symbol_link;
 687
 688         sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
 689         sysfs_attr_init(&dev->weight_attr.attr);
 690         dev->weight_attr.attr.name = dev->weight_attr_name;
 691         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 692         dev->weight_attr.show = weight_show;
 693         dev->weight_attr.store = weight_store;
 694         result = device_create_file(&tz->device, &dev->weight_attr);
 695         if (result)
 696                 goto remove_trip_file;
 697
 698         mutex_lock(&tz->lock);
 699         mutex_lock(&cdev->lock);
 700         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 701                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 702                         result = -EEXIST;
 703                         break;
 704                 }
 705         if (!result) {
 706                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 707                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 708                 atomic_set(&tz->need_update, 1);
 709         }
 710         mutex_unlock(&cdev->lock);
 711         mutex_unlock(&tz->lock);
 712
 713         if (!result)
 714                 return 0;
 715
 716         device_remove_file(&tz->device, &dev->weight_attr);
 717 remove_trip_file:
 718         device_remove_file(&tz->device, &dev->attr);
 719 remove_symbol_link:
 720         sysfs_remove_link(&tz->device.kobj, dev->name);
 721 release_ida:
 722         ida_simple_remove(&tz->ida, dev->id);
 723 free_mem:
 724         kfree(dev);
 725         return result;
 726 }
 727 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 728
 729 /**
 730  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 731  *                                        thermal zone.
 732  * @tz:         pointer to a struct thermal_zone_device.
 733  * @trip:       indicates which trip point the cooling devices is
 734  *              associated with in this thermal zone.
 735  * @cdev:       pointer to a struct thermal_cooling_device.
 736  *
 737  * This interface function unbind a thermal cooling device from the certain
 738  * trip point of a thermal zone device.
 739  * This function is usually called in the thermal zone device .unbind callback.
 740  *
 741  * Return: 0 on success, the proper error value otherwise.
 742  */
 743 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 744                                        int trip,
 745                                        struct thermal_cooling_device *cdev)
 746 {
 747         struct thermal_instance *pos, *next;
 748
 749         mutex_lock(&tz->lock);
 750         mutex_lock(&cdev->lock);
 751         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 752                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 753                         list_del(&pos->tz_node);
 754                         list_del(&pos->cdev_node);
 755                         mutex_unlock(&cdev->lock);
 756                         mutex_unlock(&tz->lock);
 757                         goto unbind;
 758                 }
 759         }
 760         mutex_unlock(&cdev->lock);
 761         mutex_unlock(&tz->lock);
 762
 763         return -ENODEV;
 764
 765 unbind:
 766         device_remove_file(&tz->device, &pos->weight_attr);
 767         device_remove_file(&tz->device, &pos->attr);
 768         sysfs_remove_link(&tz->device.kobj, pos->name);
 769         ida_simple_remove(&tz->ida, pos->id);
 770         kfree(pos);
 771         return 0;
 772 }
 773 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 774
 775 static void thermal_release(struct device *dev)
 776 {
 777         struct thermal_zone_device *tz;
 778         struct thermal_cooling_device *cdev;
 779
 780         if (!strncmp(dev_name(dev), "thermal_zone",
 781                      sizeof("thermal_zone") - 1)) {
 782                 tz = to_thermal_zone(dev);
 783                 thermal_zone_destroy_device_groups(tz);
 784                 kfree(tz);
 785         } else if (!strncmp(dev_name(dev), "cooling_device",
 786                             sizeof("cooling_device") - 1)) {
 787                 cdev = to_cooling_device(dev);
 788                 kfree(cdev);
 789         }
 790 }
 791
 792 static struct class thermal_class = {
 793         .name = "thermal",
 794         .dev_release = thermal_release,
 795 };
 796
 797 static inline
 798 void print_bind_err_msg(struct thermal_zone_device *tz,
 799                         struct thermal_cooling_device *cdev, int ret)
 800 {
 801         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
 802                 tz->type, cdev->type, ret);
 803 }
 804
 805 static void __bind(struct thermal_zone_device *tz, int mask,
 806                    struct thermal_cooling_device *cdev,
 807                    unsigned long *limits,
 808                    unsigned int weight)
 809 {
 810         int i, ret;
 811
 812         for (i = 0; i < tz->trips; i++) {
 813                 if (mask & (1 << i)) {
 814                         unsigned long upper, lower;
 815
 816                         upper = THERMAL_NO_LIMIT;
 817                         lower = THERMAL_NO_LIMIT;
 818                         if (limits) {
 819                                 lower = limits[i * 2];
 820                                 upper = limits[i * 2 + 1];
 821                         }
 822                         ret = thermal_zone_bind_cooling_device(tz, i, cdev,
 823                                                                upper, lower,
 824                                                                weight);
 825                         if (ret)
 826                                 print_bind_err_msg(tz, cdev, ret);
 827                 }
 828         }
 829 }
 830
 831 static void bind_cdev(struct thermal_cooling_device *cdev)
 832 {
 833         int i, ret;
 834         const struct thermal_zone_params *tzp;
 835         struct thermal_zone_device *pos = NULL;
 836
 837         mutex_lock(&thermal_list_lock);
 838
 839         list_for_each_entry(pos, &thermal_tz_list, node) {
 840                 if (!pos->tzp && !pos->ops->bind)
 841                         continue;
 842
 843                 if (pos->ops->bind) {
 844                         ret = pos->ops->bind(pos, cdev);
 845                         if (ret)
 846                                 print_bind_err_msg(pos, cdev, ret);
 847                         continue;
 848                 }
 849
 850                 tzp = pos->tzp;
 851                 if (!tzp || !tzp->tbp)
 852                         continue;
 853
 854                 for (i = 0; i < tzp->num_tbps; i++) {
 855                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
 856                                 continue;
 857                         if (tzp->tbp[i].match(pos, cdev))
 858                                 continue;
 859                         tzp->tbp[i].cdev = cdev;
 860                         __bind(pos, tzp->tbp[i].trip_mask, cdev,
 861                                tzp->tbp[i].binding_limits,
 862                                tzp->tbp[i].weight);
 863                 }
 864         }
 865
 866         mutex_unlock(&thermal_list_lock);
 867 }
 868
 869 /**
 870  * __thermal_cooling_device_register() - register a new thermal cooling device
 871  * @np:         a pointer to a device tree node.
 872  * @type:       the thermal cooling device type.
 873  * @devdata:    device private data.
 874  * @ops:                standard thermal cooling devices callbacks.
 875  *
 876  * This interface function adds a new thermal cooling device (fan/processor/...)
 877  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 878  * to all the thermal zone devices registered at the same time.
 879  * It also gives the opportunity to link the cooling device to a device tree
 880  * node, so that it can be bound to a thermal zone created out of device tree.
 881  *
 882  * Return: a pointer to the created struct thermal_cooling_device or an
 883  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 884  */
 885 static struct thermal_cooling_device *
 886 __thermal_cooling_device_register(struct device_node *np,
 887                                   const char *type, void *devdata,
 888                                   const struct thermal_cooling_device_ops *ops)
 889 {
 890         struct thermal_cooling_device *cdev;
 891         struct thermal_zone_device *pos = NULL;
 892         int id, ret;
 893
 894         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
 895             !ops->set_cur_state)
 896                 return ERR_PTR(-EINVAL);
 897
 898         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 899         if (!cdev)
 900                 return ERR_PTR(-ENOMEM);
 901
 902         ret = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
 903         if (ret < 0)
 904                 goto out_kfree_cdev;
 905         cdev->id = ret;
 906         id = ret;
 907
 908         ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
 909         if (ret)
 910                 goto out_ida_remove;
 911
 912         cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
 913         if (!cdev->type) {
 914                 ret = -ENOMEM;
 915                 goto out_ida_remove;
 916         }
 917
 918         mutex_init(&cdev->lock);
 919         INIT_LIST_HEAD(&cdev->thermal_instances);
 920         cdev->np = np;
 921         cdev->ops = ops;
 922         cdev->updated = false;
 923         cdev->device.class = &thermal_class;
 924         cdev->devdata = devdata;
 925         thermal_cooling_device_setup_sysfs(cdev);
 926         ret = device_register(&cdev->device);
 927         if (ret)
 928                 goto out_kfree_type;
 929
 930         /* Add 'this' new cdev to the global cdev list */
 931         mutex_lock(&thermal_list_lock);
 932         list_add(&cdev->node, &thermal_cdev_list);
 933         mutex_unlock(&thermal_list_lock);
 934
 935         /* Update binding information for 'this' new cdev */
 936         bind_cdev(cdev);
 937
 938         mutex_lock(&thermal_list_lock);
 939         list_for_each_entry(pos, &thermal_tz_list, node)
 940                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
 941                         thermal_zone_device_update(pos,
 942                                                    THERMAL_EVENT_UNSPECIFIED);
 943         mutex_unlock(&thermal_list_lock);
 944
 945         return cdev;
 946
 947 out_kfree_type:
 948         kfree(cdev->type);
 949         put_device(&cdev->device);
 950         cdev = NULL;
 951 out_ida_remove:
 952         ida_simple_remove(&thermal_cdev_ida, id);
 953 out_kfree_cdev:
 954         kfree(cdev);
 955         return ERR_PTR(ret);
 956 }
 957
 958 /**
 959  * thermal_cooling_device_register() - register a new thermal cooling device
 960  * @type:       the thermal cooling device type.
 961  * @devdata:    device private data.
 962  * @ops:                standard thermal cooling devices callbacks.
 963  *
 964  * This interface function adds a new thermal cooling device (fan/processor/...)
 965  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 966  * to all the thermal zone devices registered at the same time.
 967  *
 968  * Return: a pointer to the created struct thermal_cooling_device or an
 969  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 970  */
 971 struct thermal_cooling_device *
 972 thermal_cooling_device_register(const char *type, void *devdata,
 973                                 const struct thermal_cooling_device_ops *ops)
 974 {
 975         return __thermal_cooling_device_register(NULL, type, devdata, ops);
 976 }
 977 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
 978
 979 /**
 980  * thermal_of_cooling_device_register() - register an OF thermal cooling device
 981  * @np:         a pointer to a device tree node.
 982  * @type:       the thermal cooling device type.
 983  * @devdata:    device private data.
 984  * @ops:                standard thermal cooling devices callbacks.
 985  *
 986  * This function will register a cooling device with device tree node reference.
 987  * This interface function adds a new thermal cooling device (fan/processor/...)
 988  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 989  * to all the thermal zone devices registered at the same time.
 990  *
 991  * Return: a pointer to the created struct thermal_cooling_device or an
 992  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 993  */
 994 struct thermal_cooling_device *
 995 thermal_of_cooling_device_register(struct device_node *np,
 996                                    const char *type, void *devdata,
 997                                    const struct thermal_cooling_device_ops *ops)
 998 {
 999         return __thermal_cooling_device_register(np, type, devdata, ops);
1000 }
1001 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1002
1003 static void thermal_cooling_device_release(struct device *dev, void *res)
1004 {
1005         thermal_cooling_device_unregister(
1006                                 *(struct thermal_cooling_device **)res);
1007 }
1008
1009 /**
1010  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1011  *                                             device
1012  * @dev:        a valid struct device pointer of a sensor device.
1013  * @np:         a pointer to a device tree node.
1014  * @type:       the thermal cooling device type.
1015  * @devdata:    device private data.
1016  * @ops:        standard thermal cooling devices callbacks.
1017  *
1018  * This function will register a cooling device with device tree node reference.
1019  * This interface function adds a new thermal cooling device (fan/processor/...)
1020  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1021  * to all the thermal zone devices registered at the same time.
1022  *
1023  * Return: a pointer to the created struct thermal_cooling_device or an
1024  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1025  */
1026 struct thermal_cooling_device *
1027 devm_thermal_of_cooling_device_register(struct device *dev,
1028                                 struct device_node *np,
1029                                 char *type, void *devdata,
1030                                 const struct thermal_cooling_device_ops *ops)
1031 {
1032         struct thermal_cooling_device **ptr, *tcd;
1033
1034         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1035                            GFP_KERNEL);
1036         if (!ptr)
1037                 return ERR_PTR(-ENOMEM);
1038
1039         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1040         if (IS_ERR(tcd)) {
1041                 devres_free(ptr);
1042                 return tcd;
1043         }
1044
1045         *ptr = tcd;
1046         devres_add(dev, ptr);
1047
1048         return tcd;
1049 }
1050 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1051
1052 static void __unbind(struct thermal_zone_device *tz, int mask,
1053                      struct thermal_cooling_device *cdev)
1054 {
1055         int i;
1056
1057         for (i = 0; i < tz->trips; i++)
1058                 if (mask & (1 << i))
1059                         thermal_zone_unbind_cooling_device(tz, i, cdev);
1060 }
1061
1062 /**
1063  * thermal_cooling_device_unregister - removes a thermal cooling device
1064  * @cdev:       the thermal cooling device to remove.
1065  *
1066  * thermal_cooling_device_unregister() must be called when a registered
1067  * thermal cooling device is no longer needed.
1068  */
1069 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1070 {
1071         int i;
1072         const struct thermal_zone_params *tzp;
1073         struct thermal_zone_device *tz;
1074         struct thermal_cooling_device *pos = NULL;
1075
1076         if (!cdev)
1077                 return;
1078
1079         mutex_lock(&thermal_list_lock);
1080         list_for_each_entry(pos, &thermal_cdev_list, node)
1081                 if (pos == cdev)
1082                         break;
1083         if (pos != cdev) {
1084                 /* thermal cooling device not found */
1085                 mutex_unlock(&thermal_list_lock);
1086                 return;
1087         }
1088         list_del(&cdev->node);
1089
1090         /* Unbind all thermal zones associated with 'this' cdev */
1091         list_for_each_entry(tz, &thermal_tz_list, node) {
1092                 if (tz->ops->unbind) {
1093                         tz->ops->unbind(tz, cdev);
1094                         continue;
1095                 }
1096
1097                 if (!tz->tzp || !tz->tzp->tbp)
1098                         continue;
1099
1100                 tzp = tz->tzp;
1101                 for (i = 0; i < tzp->num_tbps; i++) {
1102                         if (tzp->tbp[i].cdev == cdev) {
1103                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1104                                 tzp->tbp[i].cdev = NULL;
1105                         }
1106                 }
1107         }
1108
1109         mutex_unlock(&thermal_list_lock);
1110
1111         ida_simple_remove(&thermal_cdev_ida, cdev->id);
1112         device_del(&cdev->device);
1113         thermal_cooling_device_destroy_sysfs(cdev);
1114         kfree(cdev->type);
1115         put_device(&cdev->device);
1116 }
1117 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1118
1119 static void bind_tz(struct thermal_zone_device *tz)
1120 {
1121         int i, ret;
1122         struct thermal_cooling_device *pos = NULL;
1123         const struct thermal_zone_params *tzp = tz->tzp;
1124
1125         if (!tzp && !tz->ops->bind)
1126                 return;
1127
1128         mutex_lock(&thermal_list_lock);
1129
1130         /* If there is ops->bind, try to use ops->bind */
1131         if (tz->ops->bind) {
1132                 list_for_each_entry(pos, &thermal_cdev_list, node) {
1133                         ret = tz->ops->bind(tz, pos);
1134                         if (ret)
1135                                 print_bind_err_msg(tz, pos, ret);
1136                 }
1137                 goto exit;
1138         }
1139
1140         if (!tzp || !tzp->tbp)
1141                 goto exit;
1142
1143         list_for_each_entry(pos, &thermal_cdev_list, node) {
1144                 for (i = 0; i < tzp->num_tbps; i++) {
1145                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1146                                 continue;
1147                         if (tzp->tbp[i].match(tz, pos))
1148                                 continue;
1149                         tzp->tbp[i].cdev = pos;
1150                         __bind(tz, tzp->tbp[i].trip_mask, pos,
1151                                tzp->tbp[i].binding_limits,
1152                                tzp->tbp[i].weight);
1153                 }
1154         }
1155 exit:
1156         mutex_unlock(&thermal_list_lock);
1157 }
1158
1159 /**
1160  * thermal_zone_device_register() - register a new thermal zone device
1161  * @type:       the thermal zone device type
1162  * @trips:      the number of trip points the thermal zone support
1163  * @mask:       a bit string indicating the writeablility of trip points
1164  * @devdata:    private device data
1165  * @ops:        standard thermal zone device callbacks
1166  * @tzp:        thermal zone platform parameters
1167  * @passive_delay: number of milliseconds to wait between polls when
1168  *                 performing passive cooling
1169  * @polling_delay: number of milliseconds to wait between polls when checking
1170  *                 whether trip points have been crossed (0 for interrupt
1171  *                 driven systems)
1172  *
1173  * This interface function adds a new thermal zone device (sensor) to
1174  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1175  * thermal cooling devices registered at the same time.
1176  * thermal_zone_device_unregister() must be called when the device is no
1177  * longer needed. The passive cooling depends on the .get_trend() return value.
1178  *
1179  * Return: a pointer to the created struct thermal_zone_device or an
1180  * in case of error, an ERR_PTR. Caller must check return value with
1181  * IS_ERR*() helpers.
1182  */
1183 struct thermal_zone_device *
1184 thermal_zone_device_register(const char *type, int trips, int mask,
1185                              void *devdata, struct thermal_zone_device_ops *ops,
1186                              struct thermal_zone_params *tzp, int passive_delay,
1187                              int polling_delay)
1188 {
1189         struct thermal_zone_device *tz;
1190         enum thermal_trip_type trip_type;
1191         int trip_temp;
1192         int id;
1193         int result;
1194         int count;
1195         struct thermal_governor *governor;
1196
1197         if (!type || strlen(type) == 0) {
1198                 pr_err("Error: No thermal zone type defined\n");
1199                 return ERR_PTR(-EINVAL);
1200         }
1201
1202         if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
1203                 pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
1204                        type, THERMAL_NAME_LENGTH);
1205                 return ERR_PTR(-EINVAL);
1206         }
1207
1208         if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
1209                 pr_err("Error: Incorrect number of thermal trips\n");
1210                 return ERR_PTR(-EINVAL);
1211         }
1212
1213         if (!ops) {
1214                 pr_err("Error: Thermal zone device ops not defined\n");
1215                 return ERR_PTR(-EINVAL);
1216         }
1217
1218         if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1219                 return ERR_PTR(-EINVAL);
1220
1221         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1222         if (!tz)
1223                 return ERR_PTR(-ENOMEM);
1224
1225         INIT_LIST_HEAD(&tz->thermal_instances);
1226         ida_init(&tz->ida);
1227         mutex_init(&tz->lock);
1228         id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1229         if (id < 0) {
1230                 result = id;
1231                 goto free_tz;
1232         }
1233
1234         tz->id = id;
1235         strlcpy(tz->type, type, sizeof(tz->type));
1236
1237         result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1238         if (result)
1239                 goto remove_id;
1240
1241         if (!ops->critical)
1242                 ops->critical = thermal_zone_device_critical;
1243
1244         tz->ops = ops;
1245         tz->tzp = tzp;
1246         tz->device.class = &thermal_class;
1247         tz->devdata = devdata;
1248         tz->trips = trips;
1249
1250         thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1251         thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1252
1253         /* sys I/F */
1254         /* Add nodes that are always present via .groups */
1255         result = thermal_zone_create_device_groups(tz, mask);
1256         if (result)
1257                 goto remove_id;
1258
1259         /* A new thermal zone needs to be updated anyway. */
1260         atomic_set(&tz->need_update, 1);
1261
1262         result = device_register(&tz->device);
1263         if (result)
1264                 goto release_device;
1265
1266         for (count = 0; count < trips; count++) {
1267                 if (tz->ops->get_trip_type(tz, count, &trip_type) ||
1268                     tz->ops->get_trip_temp(tz, count, &trip_temp) ||
1269                     !trip_temp)
1270                         set_bit(count, &tz->trips_disabled);
1271         }
1272
1273         /* Update 'this' zone's governor information */
1274         mutex_lock(&thermal_governor_lock);
1275
1276         if (tz->tzp)
1277                 governor = __find_governor(tz->tzp->governor_name);
1278         else
1279                 governor = def_governor;
1280
1281         result = thermal_set_governor(tz, governor);
1282         if (result) {
1283                 mutex_unlock(&thermal_governor_lock);
1284                 goto unregister;
1285         }
1286
1287         mutex_unlock(&thermal_governor_lock);
1288
1289         if (!tz->tzp || !tz->tzp->no_hwmon) {
1290                 result = thermal_add_hwmon_sysfs(tz);
1291                 if (result)
1292                         goto unregister;
1293         }
1294
1295         mutex_lock(&thermal_list_lock);
1296         list_add_tail(&tz->node, &thermal_tz_list);
1297         mutex_unlock(&thermal_list_lock);
1298
1299         /* Bind cooling devices for this zone */
1300         bind_tz(tz);
1301
1302         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1303
1304         thermal_zone_device_init(tz);
1305         /* Update the new thermal zone and mark it as already updated. */
1306         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1307                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1308
1309         thermal_notify_tz_create(tz->id, tz->type);
1310
1311         return tz;
1312
1313 unregister:
1314         device_del(&tz->device);
1315 release_device:
1316         put_device(&tz->device);
1317         tz = NULL;
1318 remove_id:
1319         ida_simple_remove(&thermal_tz_ida, id);
1320 free_tz:
1321         kfree(tz);
1322         return ERR_PTR(result);
1323 }
1324 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1325
1326 /**
1327  * thermal_zone_device_unregister - removes the registered thermal zone device
1328  * @tz: the thermal zone device to remove
1329  */
1330 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1331 {
1332         int i, tz_id;
1333         const struct thermal_zone_params *tzp;
1334         struct thermal_cooling_device *cdev;
1335         struct thermal_zone_device *pos = NULL;
1336
1337         if (!tz)
1338                 return;
1339
1340         tzp = tz->tzp;
1341         tz_id = tz->id;
1342
1343         mutex_lock(&thermal_list_lock);
1344         list_for_each_entry(pos, &thermal_tz_list, node)
1345                 if (pos == tz)
1346                         break;
1347         if (pos != tz) {
1348                 /* thermal zone device not found */
1349                 mutex_unlock(&thermal_list_lock);
1350                 return;
1351         }
1352         list_del(&tz->node);
1353
1354         /* Unbind all cdevs associated with 'this' thermal zone */
1355         list_for_each_entry(cdev, &thermal_cdev_list, node) {
1356                 if (tz->ops->unbind) {
1357                         tz->ops->unbind(tz, cdev);
1358                         continue;
1359                 }
1360
1361                 if (!tzp || !tzp->tbp)
1362                         break;
1363
1364                 for (i = 0; i < tzp->num_tbps; i++) {
1365                         if (tzp->tbp[i].cdev == cdev) {
1366                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1367                                 tzp->tbp[i].cdev = NULL;
1368                         }
1369                 }
1370         }
1371
1372         mutex_unlock(&thermal_list_lock);
1373
1374         cancel_delayed_work_sync(&tz->poll_queue);
1375
1376         thermal_set_governor(tz, NULL);
1377
1378         thermal_remove_hwmon_sysfs(tz);
1379         ida_simple_remove(&thermal_tz_ida, tz->id);
1380         ida_destroy(&tz->ida);
1381         mutex_destroy(&tz->lock);
1382         device_unregister(&tz->device);
1383
1384         thermal_notify_tz_delete(tz_id);
1385 }
1386 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1387
1388 /**
1389  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1390  * @name: thermal zone name to fetch the temperature
1391  *
1392  * When only one zone is found with the passed name, returns a reference to it.
1393  *
1394  * Return: On success returns a reference to an unique thermal zone with
1395  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1396  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1397  */
1398 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1399 {
1400         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1401         unsigned int found = 0;
1402
1403         if (!name)
1404                 goto exit;
1405
1406         mutex_lock(&thermal_list_lock);
1407         list_for_each_entry(pos, &thermal_tz_list, node)
1408                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1409                         found++;
1410                         ref = pos;
1411                 }
1412         mutex_unlock(&thermal_list_lock);
1413
1414         /* nothing has been found, thus an error code for it */
1415         if (found == 0)
1416                 ref = ERR_PTR(-ENODEV);
1417         else if (found > 1)
1418         /* Success only when an unique zone is found */
1419                 ref = ERR_PTR(-EEXIST);
1420
1421 exit:
1422         return ref;
1423 }
1424 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1425
1426 static int thermal_pm_notify(struct notifier_block *nb,
1427                              unsigned long mode, void *_unused)
1428 {
1429         struct thermal_zone_device *tz;
1430
1431         switch (mode) {
1432         case PM_HIBERNATION_PREPARE:
1433         case PM_RESTORE_PREPARE:
1434         case PM_SUSPEND_PREPARE:
1435                 atomic_set(&in_suspend, 1);
1436                 break;
1437         case PM_POST_HIBERNATION:
1438         case PM_POST_RESTORE:
1439         case PM_POST_SUSPEND:
1440                 atomic_set(&in_suspend, 0);
1441                 list_for_each_entry(tz, &thermal_tz_list, node) {
1442                         if (!thermal_zone_device_is_enabled(tz))
1443                                 continue;
1444
1445                         thermal_zone_device_init(tz);
1446                         thermal_zone_device_update(tz,
1447                                                    THERMAL_EVENT_UNSPECIFIED);
1448                 }
1449                 break;
1450         default:
1451                 break;
1452         }
1453         return 0;
1454 }
1455
1456 static struct notifier_block thermal_pm_nb = {
1457         .notifier_call = thermal_pm_notify,
1458 };
1459
1460 static int __init thermal_init(void)
1461 {
1462         int result;
1463
1464         result = thermal_netlink_init();
1465         if (result)
1466                 goto error;
1467
1468         result = thermal_register_governors();
1469         if (result)
1470                 goto error;
1471
1472         result = class_register(&thermal_class);
1473         if (result)
1474                 goto unregister_governors;
1475
1476         result = of_parse_thermal_zones();
1477         if (result)
1478                 goto unregister_class;
1479
1480         result = register_pm_notifier(&thermal_pm_nb);
1481         if (result)
1482                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1483                         result);
1484
1485         return 0;
1486
1487 unregister_class:
1488         class_unregister(&thermal_class);
1489 unregister_governors:
1490         thermal_unregister_governors();
1491 error:
1492         ida_destroy(&thermal_tz_ida);
1493         ida_destroy(&thermal_cdev_ida);
1494         mutex_destroy(&thermal_list_lock);
1495         mutex_destroy(&thermal_governor_lock);
1496         return result;
1497 }
1498 postcore_initcall(thermal_init);