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