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