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