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         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                                             int delay)
 291 {
 292         if (delay > 1000)
 293                 mod_delayed_work(system_freezable_power_efficient_wq,
 294                                  &tz->poll_queue,
 295                                  round_jiffies(msecs_to_jiffies(delay)));
 296         else if (delay)
 297                 mod_delayed_work(system_freezable_power_efficient_wq,
 298                                  &tz->poll_queue,
 299                                  msecs_to_jiffies(delay));
 300         else
 301                 cancel_delayed_work(&tz->poll_queue);
 302 }
 303
 304 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 305 {
 306         mutex_lock(&tz->lock);
 307
 308         if (tz->passive)
 309                 thermal_zone_device_set_polling(tz, tz->passive_delay);
 310         else if (tz->polling_delay)
 311                 thermal_zone_device_set_polling(tz, tz->polling_delay);
 312         else
 313                 thermal_zone_device_set_polling(tz, 0);
 314
 315         mutex_unlock(&tz->lock);
 316 }
 317
 318 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 319 {
 320         tz->governor ? tz->governor->throttle(tz, trip) :
 321                        def_governor->throttle(tz, trip);
 322 }
 323
 324 /**
 325  * thermal_emergency_poweroff_func - emergency poweroff work after a known delay
 326  * @work: work_struct associated with the emergency poweroff function
 327  *
 328  * This function is called in very critical situations to force
 329  * a kernel poweroff after a configurable timeout value.
 330  */
 331 static void thermal_emergency_poweroff_func(struct work_struct *work)
 332 {
 333         /*
 334          * We have reached here after the emergency thermal shutdown
 335          * Waiting period has expired. This means orderly_poweroff has
 336          * not been able to shut off the system for some reason.
 337          * Try to shut down the system immediately using kernel_power_off
 338          * if populated
 339          */
 340         WARN(1, "Attempting kernel_power_off: Temperature too high\n");
 341         kernel_power_off();
 342
 343         /*
 344          * Worst of the worst case trigger emergency restart
 345          */
 346         WARN(1, "Attempting emergency_restart: Temperature too high\n");
 347         emergency_restart();
 348 }
 349
 350 static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work,
 351                             thermal_emergency_poweroff_func);
 352
 353 /**
 354  * thermal_emergency_poweroff - Trigger an emergency system poweroff
 355  *
 356  * This may be called from any critical situation to trigger a system shutdown
 357  * after a known period of time. By default this is not scheduled.
 358  */
 359 static void thermal_emergency_poweroff(void)
 360 {
 361         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 362         /*
 363          * poweroff_delay_ms must be a carefully profiled positive value.
 364          * Its a must for thermal_emergency_poweroff_work to be scheduled
 365          */
 366         if (poweroff_delay_ms <= 0)
 367                 return;
 368         schedule_delayed_work(&thermal_emergency_poweroff_work,
 369                               msecs_to_jiffies(poweroff_delay_ms));
 370 }
 371
 372 static void handle_critical_trips(struct thermal_zone_device *tz,
 373                                   int trip, enum thermal_trip_type trip_type)
 374 {
 375         int trip_temp;
 376
 377         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 378
 379         /* If we have not crossed the trip_temp, we do not care. */
 380         if (trip_temp <= 0 || tz->temperature < trip_temp)
 381                 return;
 382
 383         trace_thermal_zone_trip(tz, trip, trip_type);
 384
 385         if (tz->ops->notify)
 386                 tz->ops->notify(tz, trip, trip_type);
 387
 388         if (trip_type == THERMAL_TRIP_CRITICAL) {
 389                 dev_emerg(&tz->device,
 390                           "critical temperature reached (%d C), shutting down\n",
 391                           tz->temperature / 1000);
 392                 mutex_lock(&poweroff_lock);
 393                 if (!power_off_triggered) {
 394                         /*
 395                          * Queue a backup emergency shutdown in the event of
 396                          * orderly_poweroff failure
 397                          */
 398                         thermal_emergency_poweroff();
 399                         orderly_poweroff(true);
 400                         power_off_triggered = true;
 401                 }
 402                 mutex_unlock(&poweroff_lock);
 403         }
 404 }
 405
 406 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
 407 {
 408         enum thermal_trip_type type;
 409
 410         /* Ignore disabled trip points */
 411         if (test_bit(trip, &tz->trips_disabled))
 412                 return;
 413
 414         tz->ops->get_trip_type(tz, trip, &type);
 415
 416         if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
 417                 handle_critical_trips(tz, trip, type);
 418         else
 419                 handle_non_critical_trips(tz, trip);
 420         /*
 421          * Alright, we handled this trip successfully.
 422          * So, start monitoring again.
 423          */
 424         monitor_thermal_zone(tz);
 425 }
 426
 427 static void update_temperature(struct thermal_zone_device *tz)
 428 {
 429         int temp, ret;
 430
 431         ret = thermal_zone_get_temp(tz, &temp);
 432         if (ret) {
 433                 if (ret != -EAGAIN)
 434                         dev_warn(&tz->device,
 435                                  "failed to read out thermal zone (%d)\n",
 436                                  ret);
 437                 return;
 438         }
 439
 440         mutex_lock(&tz->lock);
 441         tz->last_temperature = tz->temperature;
 442         tz->temperature = temp;
 443         mutex_unlock(&tz->lock);
 444
 445         trace_thermal_temperature(tz);
 446 }
 447
 448 static void thermal_zone_device_init(struct thermal_zone_device *tz)
 449 {
 450         struct thermal_instance *pos;
 451         tz->temperature = THERMAL_TEMP_INVALID;
 452         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 453                 pos->initialized = false;
 454 }
 455
 456 static void thermal_zone_device_reset(struct thermal_zone_device *tz)
 457 {
 458         tz->passive = 0;
 459         thermal_zone_device_init(tz);
 460 }
 461
 462 void thermal_zone_device_update(struct thermal_zone_device *tz,
 463                                 enum thermal_notify_event event)
 464 {
 465         int count;
 466
 467         if (atomic_read(&in_suspend))
 468                 return;
 469
 470         if (!tz->ops->get_temp)
 471                 return;
 472
 473         update_temperature(tz);
 474
 475         thermal_zone_set_trips(tz);
 476
 477         tz->notify_event = event;
 478
 479         for (count = 0; count < tz->trips; count++)
 480                 handle_thermal_trip(tz, count);
 481 }
 482 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 483
 484 /**
 485  * thermal_notify_framework - Sensor drivers use this API to notify framework
 486  * @tz:         thermal zone device
 487  * @trip:       indicates which trip point has been crossed
 488  *
 489  * This function handles the trip events from sensor drivers. It starts
 490  * throttling the cooling devices according to the policy configured.
 491  * For CRITICAL and HOT trip points, this notifies the respective drivers,
 492  * and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
 493  * The throttling policy is based on the configured platform data; if no
 494  * platform data is provided, this uses the step_wise throttling policy.
 495  */
 496 void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
 497 {
 498         handle_thermal_trip(tz, trip);
 499 }
 500 EXPORT_SYMBOL_GPL(thermal_notify_framework);
 501
 502 static void thermal_zone_device_check(struct work_struct *work)
 503 {
 504         struct thermal_zone_device *tz = container_of(work, struct
 505                                                       thermal_zone_device,
 506                                                       poll_queue.work);
 507         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 508 }
 509
 510 /*
 511  * Power actor section: interface to power actors to estimate power
 512  *
 513  * Set of functions used to interact to cooling devices that know
 514  * how to estimate their devices power consumption.
 515  */
 516
 517 /**
 518  * power_actor_get_max_power() - get the maximum power that a cdev can consume
 519  * @cdev:       pointer to &thermal_cooling_device
 520  * @tz:         a valid thermal zone device pointer
 521  * @max_power:  pointer in which to store the maximum power
 522  *
 523  * Calculate the maximum power consumption in milliwats that the
 524  * cooling device can currently consume and store it in @max_power.
 525  *
 526  * Return: 0 on success, -EINVAL if @cdev doesn't support the
 527  * power_actor API or -E* on other error.
 528  */
 529 int power_actor_get_max_power(struct thermal_cooling_device *cdev,
 530                               struct thermal_zone_device *tz, u32 *max_power)
 531 {
 532         if (!cdev_is_power_actor(cdev))
 533                 return -EINVAL;
 534
 535         return cdev->ops->state2power(cdev, tz, 0, max_power);
 536 }
 537
 538 /**
 539  * power_actor_get_min_power() - get the mainimum power that a cdev can consume
 540  * @cdev:       pointer to &thermal_cooling_device
 541  * @tz:         a valid thermal zone device pointer
 542  * @min_power:  pointer in which to store the minimum power
 543  *
 544  * Calculate the minimum power consumption in milliwatts that the
 545  * cooling device can currently consume and store it in @min_power.
 546  *
 547  * Return: 0 on success, -EINVAL if @cdev doesn't support the
 548  * power_actor API or -E* on other error.
 549  */
 550 int power_actor_get_min_power(struct thermal_cooling_device *cdev,
 551                               struct thermal_zone_device *tz, u32 *min_power)
 552 {
 553         unsigned long max_state;
 554         int ret;
 555
 556         if (!cdev_is_power_actor(cdev))
 557                 return -EINVAL;
 558
 559         ret = cdev->ops->get_max_state(cdev, &max_state);
 560         if (ret)
 561                 return ret;
 562
 563         return cdev->ops->state2power(cdev, tz, max_state, min_power);
 564 }
 565
 566 /**
 567  * power_actor_set_power() - limit the maximum power a cooling device consumes
 568  * @cdev:       pointer to &thermal_cooling_device
 569  * @instance:   thermal instance to update
 570  * @power:      the power in milliwatts
 571  *
 572  * Set the cooling device to consume at most @power milliwatts. The limit is
 573  * expected to be a cap at the maximum power consumption.
 574  *
 575  * Return: 0 on success, -EINVAL if the cooling device does not
 576  * implement the power actor API or -E* for other failures.
 577  */
 578 int power_actor_set_power(struct thermal_cooling_device *cdev,
 579                           struct thermal_instance *instance, u32 power)
 580 {
 581         unsigned long state;
 582         int ret;
 583
 584         if (!cdev_is_power_actor(cdev))
 585                 return -EINVAL;
 586
 587         ret = cdev->ops->power2state(cdev, instance->tz, power, &state);
 588         if (ret)
 589                 return ret;
 590
 591         instance->target = state;
 592         mutex_lock(&cdev->lock);
 593         cdev->updated = false;
 594         mutex_unlock(&cdev->lock);
 595         thermal_cdev_update(cdev);
 596
 597         return 0;
 598 }
 599
 600 void thermal_zone_device_rebind_exception(struct thermal_zone_device *tz,
 601                                           const char *cdev_type, size_t size)
 602 {
 603         struct thermal_cooling_device *cdev = NULL;
 604
 605         mutex_lock(&thermal_list_lock);
 606         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 607                 /* skip non matching cdevs */
 608                 if (strncmp(cdev_type, cdev->type, size))
 609                         continue;
 610
 611                 /* re binding the exception matching the type pattern */
 612                 thermal_zone_bind_cooling_device(tz, THERMAL_TRIPS_NONE, cdev,
 613                                                  THERMAL_NO_LIMIT,
 614                                                  THERMAL_NO_LIMIT,
 615                                                  THERMAL_WEIGHT_DEFAULT);
 616         }
 617         mutex_unlock(&thermal_list_lock);
 618 }
 619
 620 void thermal_zone_device_unbind_exception(struct thermal_zone_device *tz,
 621                                           const char *cdev_type, size_t size)
 622 {
 623         struct thermal_cooling_device *cdev = NULL;
 624
 625         mutex_lock(&thermal_list_lock);
 626         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 627                 /* skip non matching cdevs */
 628                 if (strncmp(cdev_type, cdev->type, size))
 629                         continue;
 630                 /* unbinding the exception matching the type pattern */
 631                 thermal_zone_unbind_cooling_device(tz, THERMAL_TRIPS_NONE,
 632                                                    cdev);
 633         }
 634         mutex_unlock(&thermal_list_lock);
 635 }
 636
 637 /*
 638  * Device management section: cooling devices, zones devices, and binding
 639  *
 640  * Set of functions provided by the thermal core for:
 641  * - cooling devices lifecycle: registration, unregistration,
 642  *                              binding, and unbinding.
 643  * - thermal zone devices lifecycle: registration, unregistration,
 644  *                                   binding, and unbinding.
 645  */
 646
 647 /**
 648  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 649  * @tz:         pointer to struct thermal_zone_device
 650  * @trip:       indicates which trip point the cooling devices is
 651  *              associated with in this thermal zone.
 652  * @cdev:       pointer to struct thermal_cooling_device
 653  * @upper:      the Maximum cooling state for this trip point.
 654  *              THERMAL_NO_LIMIT means no upper limit,
 655  *              and the cooling device can be in max_state.
 656  * @lower:      the Minimum cooling state can be used for this trip point.
 657  *              THERMAL_NO_LIMIT means no lower limit,
 658  *              and the cooling device can be in cooling state 0.
 659  * @weight:     The weight of the cooling device to be bound to the
 660  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 661  *              default value
 662  *
 663  * This interface function bind a thermal cooling device to the certain trip
 664  * point of a thermal zone device.
 665  * This function is usually called in the thermal zone device .bind callback.
 666  *
 667  * Return: 0 on success, the proper error value otherwise.
 668  */
 669 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 670                                      int trip,
 671                                      struct thermal_cooling_device *cdev,
 672                                      unsigned long upper, unsigned long lower,
 673                                      unsigned int weight)
 674 {
 675         struct thermal_instance *dev;
 676         struct thermal_instance *pos;
 677         struct thermal_zone_device *pos1;
 678         struct thermal_cooling_device *pos2;
 679         unsigned long max_state;
 680         int result, ret;
 681
 682         if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE))
 683                 return -EINVAL;
 684
 685         list_for_each_entry(pos1, &thermal_tz_list, node) {
 686                 if (pos1 == tz)
 687                         break;
 688         }
 689         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 690                 if (pos2 == cdev)
 691                         break;
 692         }
 693
 694         if (tz != pos1 || cdev != pos2)
 695                 return -EINVAL;
 696
 697         ret = cdev->ops->get_max_state(cdev, &max_state);
 698         if (ret)
 699                 return ret;
 700
 701         /* lower default 0, upper default max_state */
 702         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 703         upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
 704
 705         if (lower > upper || upper > max_state)
 706                 return -EINVAL;
 707
 708         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 709         if (!dev)
 710                 return -ENOMEM;
 711         dev->tz = tz;
 712         dev->cdev = cdev;
 713         dev->trip = trip;
 714         dev->upper = upper;
 715         dev->lower = lower;
 716         dev->target = THERMAL_NO_TARGET;
 717         dev->weight = weight;
 718
 719         result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
 720         if (result < 0)
 721                 goto free_mem;
 722
 723         dev->id = result;
 724         sprintf(dev->name, "cdev%d", dev->id);
 725         result =
 726             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 727         if (result)
 728                 goto release_ida;
 729
 730         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 731         sysfs_attr_init(&dev->attr.attr);
 732         dev->attr.attr.name = dev->attr_name;
 733         dev->attr.attr.mode = 0444;
 734         dev->attr.show = trip_point_show;
 735         result = device_create_file(&tz->device, &dev->attr);
 736         if (result)
 737                 goto remove_symbol_link;
 738
 739         sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
 740         sysfs_attr_init(&dev->weight_attr.attr);
 741         dev->weight_attr.attr.name = dev->weight_attr_name;
 742         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 743         dev->weight_attr.show = weight_show;
 744         dev->weight_attr.store = weight_store;
 745         result = device_create_file(&tz->device, &dev->weight_attr);
 746         if (result)
 747                 goto remove_trip_file;
 748
 749         mutex_lock(&tz->lock);
 750         mutex_lock(&cdev->lock);
 751         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 752                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 753                         result = -EEXIST;
 754                         break;
 755                 }
 756         if (!result) {
 757                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 758                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 759                 atomic_set(&tz->need_update, 1);
 760         }
 761         mutex_unlock(&cdev->lock);
 762         mutex_unlock(&tz->lock);
 763
 764         if (!result)
 765                 return 0;
 766
 767         device_remove_file(&tz->device, &dev->weight_attr);
 768 remove_trip_file:
 769         device_remove_file(&tz->device, &dev->attr);
 770 remove_symbol_link:
 771         sysfs_remove_link(&tz->device.kobj, dev->name);
 772 release_ida:
 773         ida_simple_remove(&tz->ida, dev->id);
 774 free_mem:
 775         kfree(dev);
 776         return result;
 777 }
 778 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 779
 780 /**
 781  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 782  *                                        thermal zone.
 783  * @tz:         pointer to a struct thermal_zone_device.
 784  * @trip:       indicates which trip point the cooling devices is
 785  *              associated with in this thermal zone.
 786  * @cdev:       pointer to a struct thermal_cooling_device.
 787  *
 788  * This interface function unbind a thermal cooling device from the certain
 789  * trip point of a thermal zone device.
 790  * This function is usually called in the thermal zone device .unbind callback.
 791  *
 792  * Return: 0 on success, the proper error value otherwise.
 793  */
 794 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 795                                        int trip,
 796                                        struct thermal_cooling_device *cdev)
 797 {
 798         struct thermal_instance *pos, *next;
 799
 800         mutex_lock(&tz->lock);
 801         mutex_lock(&cdev->lock);
 802         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 803                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 804                         list_del(&pos->tz_node);
 805                         list_del(&pos->cdev_node);
 806                         mutex_unlock(&cdev->lock);
 807                         mutex_unlock(&tz->lock);
 808                         goto unbind;
 809                 }
 810         }
 811         mutex_unlock(&cdev->lock);
 812         mutex_unlock(&tz->lock);
 813
 814         return -ENODEV;
 815
 816 unbind:
 817         device_remove_file(&tz->device, &pos->weight_attr);
 818         device_remove_file(&tz->device, &pos->attr);
 819         sysfs_remove_link(&tz->device.kobj, pos->name);
 820         ida_simple_remove(&tz->ida, pos->id);
 821         kfree(pos);
 822         return 0;
 823 }
 824 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 825
 826 static void thermal_release(struct device *dev)
 827 {
 828         struct thermal_zone_device *tz;
 829         struct thermal_cooling_device *cdev;
 830
 831         if (!strncmp(dev_name(dev), "thermal_zone",
 832                      sizeof("thermal_zone") - 1)) {
 833                 tz = to_thermal_zone(dev);
 834                 thermal_zone_destroy_device_groups(tz);
 835                 kfree(tz);
 836         } else if (!strncmp(dev_name(dev), "cooling_device",
 837                             sizeof("cooling_device") - 1)) {
 838                 cdev = to_cooling_device(dev);
 839                 kfree(cdev);
 840         }
 841 }
 842
 843 static struct class thermal_class = {
 844         .name = "thermal",
 845         .dev_release = thermal_release,
 846 };
 847
 848 static inline
 849 void print_bind_err_msg(struct thermal_zone_device *tz,
 850                         struct thermal_cooling_device *cdev, int ret)
 851 {
 852         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
 853                 tz->type, cdev->type, ret);
 854 }
 855
 856 static void __bind(struct thermal_zone_device *tz, int mask,
 857                    struct thermal_cooling_device *cdev,
 858                    unsigned long *limits,
 859                    unsigned int weight)
 860 {
 861         int i, ret;
 862
 863         for (i = 0; i < tz->trips; i++) {
 864                 if (mask & (1 << i)) {
 865                         unsigned long upper, lower;
 866
 867                         upper = THERMAL_NO_LIMIT;
 868                         lower = THERMAL_NO_LIMIT;
 869                         if (limits) {
 870                                 lower = limits[i * 2];
 871                                 upper = limits[i * 2 + 1];
 872                         }
 873                         ret = thermal_zone_bind_cooling_device(tz, i, cdev,
 874                                                                upper, lower,
 875                                                                weight);
 876                         if (ret)
 877                                 print_bind_err_msg(tz, cdev, ret);
 878                 }
 879         }
 880 }
 881
 882 static void bind_cdev(struct thermal_cooling_device *cdev)
 883 {
 884         int i, ret;
 885         const struct thermal_zone_params *tzp;
 886         struct thermal_zone_device *pos = NULL;
 887
 888         mutex_lock(&thermal_list_lock);
 889
 890         list_for_each_entry(pos, &thermal_tz_list, node) {
 891                 if (!pos->tzp && !pos->ops->bind)
 892                         continue;
 893
 894                 if (pos->ops->bind) {
 895                         ret = pos->ops->bind(pos, cdev);
 896                         if (ret)
 897                                 print_bind_err_msg(pos, cdev, ret);
 898                         continue;
 899                 }
 900
 901                 tzp = pos->tzp;
 902                 if (!tzp || !tzp->tbp)
 903                         continue;
 904
 905                 for (i = 0; i < tzp->num_tbps; i++) {
 906                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
 907                                 continue;
 908                         if (tzp->tbp[i].match(pos, cdev))
 909                                 continue;
 910                         tzp->tbp[i].cdev = cdev;
 911                         __bind(pos, tzp->tbp[i].trip_mask, cdev,
 912                                tzp->tbp[i].binding_limits,
 913                                tzp->tbp[i].weight);
 914                 }
 915         }
 916
 917         mutex_unlock(&thermal_list_lock);
 918 }
 919
 920 /**
 921  * __thermal_cooling_device_register() - register a new thermal cooling device
 922  * @np:         a pointer to a device tree node.
 923  * @type:       the thermal cooling device type.
 924  * @devdata:    device private data.
 925  * @ops:                standard thermal cooling devices callbacks.
 926  *
 927  * This interface function adds a new thermal cooling device (fan/processor/...)
 928  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 929  * to all the thermal zone devices registered at the same time.
 930  * It also gives the opportunity to link the cooling device to a device tree
 931  * node, so that it can be bound to a thermal zone created out of device tree.
 932  *
 933  * Return: a pointer to the created struct thermal_cooling_device or an
 934  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 935  */
 936 static struct thermal_cooling_device *
 937 __thermal_cooling_device_register(struct device_node *np,
 938                                   const char *type, void *devdata,
 939                                   const struct thermal_cooling_device_ops *ops)
 940 {
 941         struct thermal_cooling_device *cdev;
 942         struct thermal_zone_device *pos = NULL;
 943         int result;
 944
 945         if (type && strlen(type) >= THERMAL_NAME_LENGTH)
 946                 return ERR_PTR(-EINVAL);
 947
 948         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
 949             !ops->set_cur_state)
 950                 return ERR_PTR(-EINVAL);
 951
 952         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 953         if (!cdev)
 954                 return ERR_PTR(-ENOMEM);
 955
 956         result = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
 957         if (result < 0) {
 958                 kfree(cdev);
 959                 return ERR_PTR(result);
 960         }
 961
 962         cdev->id = result;
 963         strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
 964         mutex_init(&cdev->lock);
 965         INIT_LIST_HEAD(&cdev->thermal_instances);
 966         cdev->np = np;
 967         cdev->ops = ops;
 968         cdev->updated = false;
 969         cdev->device.class = &thermal_class;
 970         cdev->devdata = devdata;
 971         thermal_cooling_device_setup_sysfs(cdev);
 972         dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
 973         result = device_register(&cdev->device);
 974         if (result) {
 975                 ida_simple_remove(&thermal_cdev_ida, cdev->id);
 976                 put_device(&cdev->device);
 977                 return ERR_PTR(result);
 978         }
 979
 980         /* Add 'this' new cdev to the global cdev list */
 981         mutex_lock(&thermal_list_lock);
 982         list_add(&cdev->node, &thermal_cdev_list);
 983         mutex_unlock(&thermal_list_lock);
 984
 985         /* Update binding information for 'this' new cdev */
 986         bind_cdev(cdev);
 987
 988         mutex_lock(&thermal_list_lock);
 989         list_for_each_entry(pos, &thermal_tz_list, node)
 990                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
 991                         thermal_zone_device_update(pos,
 992                                                    THERMAL_EVENT_UNSPECIFIED);
 993         mutex_unlock(&thermal_list_lock);
 994
 995         return cdev;
 996 }
 997
 998 /**
 999  * thermal_cooling_device_register() - register a new thermal cooling device
1000  * @type:       the thermal cooling device type.
1001  * @devdata:    device private data.
1002  * @ops:                standard thermal cooling devices callbacks.
1003  *
1004  * This interface function adds a new thermal cooling device (fan/processor/...)
1005  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1006  * to all the thermal zone devices registered at the same time.
1007  *
1008  * Return: a pointer to the created struct thermal_cooling_device or an
1009  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1010  */
1011 struct thermal_cooling_device *
1012 thermal_cooling_device_register(const char *type, void *devdata,
1013                                 const struct thermal_cooling_device_ops *ops)
1014 {
1015         return __thermal_cooling_device_register(NULL, type, devdata, ops);
1016 }
1017 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1018
1019 /**
1020  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1021  * @np:         a pointer to a device tree node.
1022  * @type:       the thermal cooling device type.
1023  * @devdata:    device private data.
1024  * @ops:                standard thermal cooling devices callbacks.
1025  *
1026  * This function will register a cooling device with device tree node reference.
1027  * This interface function adds a new thermal cooling device (fan/processor/...)
1028  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1029  * to all the thermal zone devices registered at the same time.
1030  *
1031  * Return: a pointer to the created struct thermal_cooling_device or an
1032  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1033  */
1034 struct thermal_cooling_device *
1035 thermal_of_cooling_device_register(struct device_node *np,
1036                                    const char *type, void *devdata,
1037                                    const struct thermal_cooling_device_ops *ops)
1038 {
1039         return __thermal_cooling_device_register(np, type, devdata, ops);
1040 }
1041 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1042
1043 static void thermal_cooling_device_release(struct device *dev, void *res)
1044 {
1045         thermal_cooling_device_unregister(
1046                                 *(struct thermal_cooling_device **)res);
1047 }
1048
1049 /**
1050  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1051  *                                             device
1052  * @dev:        a valid struct device pointer of a sensor device.
1053  * @np:         a pointer to a device tree node.
1054  * @type:       the thermal cooling device type.
1055  * @devdata:    device private data.
1056  * @ops:        standard thermal cooling devices callbacks.
1057  *
1058  * This function will register a cooling device with device tree node reference.
1059  * This interface function adds a new thermal cooling device (fan/processor/...)
1060  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1061  * to all the thermal zone devices registered at the same time.
1062  *
1063  * Return: a pointer to the created struct thermal_cooling_device or an
1064  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1065  */
1066 struct thermal_cooling_device *
1067 devm_thermal_of_cooling_device_register(struct device *dev,
1068                                 struct device_node *np,
1069                                 char *type, void *devdata,
1070                                 const struct thermal_cooling_device_ops *ops)
1071 {
1072         struct thermal_cooling_device **ptr, *tcd;
1073
1074         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1075                            GFP_KERNEL);
1076         if (!ptr)
1077                 return ERR_PTR(-ENOMEM);
1078
1079         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1080         if (IS_ERR(tcd)) {
1081                 devres_free(ptr);
1082                 return tcd;
1083         }
1084
1085         *ptr = tcd;
1086         devres_add(dev, ptr);
1087
1088         return tcd;
1089 }
1090 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1091
1092 static void __unbind(struct thermal_zone_device *tz, int mask,
1093                      struct thermal_cooling_device *cdev)
1094 {
1095         int i;
1096
1097         for (i = 0; i < tz->trips; i++)
1098                 if (mask & (1 << i))
1099                         thermal_zone_unbind_cooling_device(tz, i, cdev);
1100 }
1101
1102 /**
1103  * thermal_cooling_device_unregister - removes a thermal cooling device
1104  * @cdev:       the thermal cooling device to remove.
1105  *
1106  * thermal_cooling_device_unregister() must be called when a registered
1107  * thermal cooling device is no longer needed.
1108  */
1109 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1110 {
1111         int i;
1112         const struct thermal_zone_params *tzp;
1113         struct thermal_zone_device *tz;
1114         struct thermal_cooling_device *pos = NULL;
1115
1116         if (!cdev)
1117                 return;
1118
1119         mutex_lock(&thermal_list_lock);
1120         list_for_each_entry(pos, &thermal_cdev_list, node)
1121                 if (pos == cdev)
1122                         break;
1123         if (pos != cdev) {
1124                 /* thermal cooling device not found */
1125                 mutex_unlock(&thermal_list_lock);
1126                 return;
1127         }
1128         list_del(&cdev->node);
1129
1130         /* Unbind all thermal zones associated with 'this' cdev */
1131         list_for_each_entry(tz, &thermal_tz_list, node) {
1132                 if (tz->ops->unbind) {
1133                         tz->ops->unbind(tz, cdev);
1134                         continue;
1135                 }
1136
1137                 if (!tz->tzp || !tz->tzp->tbp)
1138                         continue;
1139
1140                 tzp = tz->tzp;
1141                 for (i = 0; i < tzp->num_tbps; i++) {
1142                         if (tzp->tbp[i].cdev == cdev) {
1143                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1144                                 tzp->tbp[i].cdev = NULL;
1145                         }
1146                 }
1147         }
1148
1149         mutex_unlock(&thermal_list_lock);
1150
1151         ida_simple_remove(&thermal_cdev_ida, cdev->id);
1152         device_del(&cdev->device);
1153         thermal_cooling_device_destroy_sysfs(cdev);
1154         put_device(&cdev->device);
1155 }
1156 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1157
1158 static void bind_tz(struct thermal_zone_device *tz)
1159 {
1160         int i, ret;
1161         struct thermal_cooling_device *pos = NULL;
1162         const struct thermal_zone_params *tzp = tz->tzp;
1163
1164         if (!tzp && !tz->ops->bind)
1165                 return;
1166
1167         mutex_lock(&thermal_list_lock);
1168
1169         /* If there is ops->bind, try to use ops->bind */
1170         if (tz->ops->bind) {
1171                 list_for_each_entry(pos, &thermal_cdev_list, node) {
1172                         ret = tz->ops->bind(tz, pos);
1173                         if (ret)
1174                                 print_bind_err_msg(tz, pos, ret);
1175                 }
1176                 goto exit;
1177         }
1178
1179         if (!tzp || !tzp->tbp)
1180                 goto exit;
1181
1182         list_for_each_entry(pos, &thermal_cdev_list, node) {
1183                 for (i = 0; i < tzp->num_tbps; i++) {
1184                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1185                                 continue;
1186                         if (tzp->tbp[i].match(tz, pos))
1187                                 continue;
1188                         tzp->tbp[i].cdev = pos;
1189                         __bind(tz, tzp->tbp[i].trip_mask, pos,
1190                                tzp->tbp[i].binding_limits,
1191                                tzp->tbp[i].weight);
1192                 }
1193         }
1194 exit:
1195         mutex_unlock(&thermal_list_lock);
1196 }
1197
1198 /**
1199  * thermal_zone_device_register() - register a new thermal zone device
1200  * @type:       the thermal zone device type
1201  * @trips:      the number of trip points the thermal zone support
1202  * @mask:       a bit string indicating the writeablility of trip points
1203  * @devdata:    private device data
1204  * @ops:        standard thermal zone device callbacks
1205  * @tzp:        thermal zone platform parameters
1206  * @passive_delay: number of milliseconds to wait between polls when
1207  *                 performing passive cooling
1208  * @polling_delay: number of milliseconds to wait between polls when checking
1209  *                 whether trip points have been crossed (0 for interrupt
1210  *                 driven systems)
1211  *
1212  * This interface function adds a new thermal zone device (sensor) to
1213  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1214  * thermal cooling devices registered at the same time.
1215  * thermal_zone_device_unregister() must be called when the device is no
1216  * longer needed. The passive cooling depends on the .get_trend() return value.
1217  *
1218  * Return: a pointer to the created struct thermal_zone_device or an
1219  * in case of error, an ERR_PTR. Caller must check return value with
1220  * IS_ERR*() helpers.
1221  */
1222 struct thermal_zone_device *
1223 thermal_zone_device_register(const char *type, int trips, int mask,
1224                              void *devdata, struct thermal_zone_device_ops *ops,
1225                              struct thermal_zone_params *tzp, int passive_delay,
1226                              int polling_delay)
1227 {
1228         struct thermal_zone_device *tz;
1229         enum thermal_trip_type trip_type;
1230         int trip_temp;
1231         int id;
1232         int result;
1233         int count;
1234         struct thermal_governor *governor;
1235
1236         if (!type || strlen(type) == 0) {
1237                 pr_err("Error: No thermal zone type defined\n");
1238                 return ERR_PTR(-EINVAL);
1239         }
1240
1241         if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
1242                 pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
1243                        type, THERMAL_NAME_LENGTH);
1244                 return ERR_PTR(-EINVAL);
1245         }
1246
1247         if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
1248                 pr_err("Error: Incorrect number of thermal trips\n");
1249                 return ERR_PTR(-EINVAL);
1250         }
1251
1252         if (!ops) {
1253                 pr_err("Error: Thermal zone device ops not defined\n");
1254                 return ERR_PTR(-EINVAL);
1255         }
1256
1257         if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1258                 return ERR_PTR(-EINVAL);
1259
1260         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1261         if (!tz)
1262                 return ERR_PTR(-ENOMEM);
1263
1264         INIT_LIST_HEAD(&tz->thermal_instances);
1265         ida_init(&tz->ida);
1266         mutex_init(&tz->lock);
1267         id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1268         if (id < 0) {
1269                 result = id;
1270                 goto free_tz;
1271         }
1272
1273         tz->id = id;
1274         strlcpy(tz->type, type, sizeof(tz->type));
1275         tz->ops = ops;
1276         tz->tzp = tzp;
1277         tz->device.class = &thermal_class;
1278         tz->devdata = devdata;
1279         tz->trips = trips;
1280         tz->passive_delay = passive_delay;
1281         tz->polling_delay = polling_delay;
1282
1283         /* sys I/F */
1284         /* Add nodes that are always present via .groups */
1285         result = thermal_zone_create_device_groups(tz, mask);
1286         if (result)
1287                 goto remove_id;
1288
1289         /* A new thermal zone needs to be updated anyway. */
1290         atomic_set(&tz->need_update, 1);
1291
1292         dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1293         result = device_register(&tz->device);
1294         if (result)
1295                 goto release_device;
1296
1297         for (count = 0; count < trips; count++) {
1298                 if (tz->ops->get_trip_type(tz, count, &trip_type))
1299                         set_bit(count, &tz->trips_disabled);
1300                 if (tz->ops->get_trip_temp(tz, count, &trip_temp))
1301                         set_bit(count, &tz->trips_disabled);
1302                 /* Check for bogus trip points */
1303                 if (trip_temp == 0)
1304                         set_bit(count, &tz->trips_disabled);
1305         }
1306
1307         /* Update 'this' zone's governor information */
1308         mutex_lock(&thermal_governor_lock);
1309
1310         if (tz->tzp)
1311                 governor = __find_governor(tz->tzp->governor_name);
1312         else
1313                 governor = def_governor;
1314
1315         result = thermal_set_governor(tz, governor);
1316         if (result) {
1317                 mutex_unlock(&thermal_governor_lock);
1318                 goto unregister;
1319         }
1320
1321         mutex_unlock(&thermal_governor_lock);
1322
1323         if (!tz->tzp || !tz->tzp->no_hwmon) {
1324                 result = thermal_add_hwmon_sysfs(tz);
1325                 if (result)
1326                         goto unregister;
1327         }
1328
1329         mutex_lock(&thermal_list_lock);
1330         list_add_tail(&tz->node, &thermal_tz_list);
1331         mutex_unlock(&thermal_list_lock);
1332
1333         /* Bind cooling devices for this zone */
1334         bind_tz(tz);
1335
1336         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1337
1338         thermal_zone_device_reset(tz);
1339         /* Update the new thermal zone and mark it as already updated. */
1340         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1341                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1342
1343         return tz;
1344
1345 unregister:
1346         device_del(&tz->device);
1347 release_device:
1348         put_device(&tz->device);
1349         tz = NULL;
1350 remove_id:
1351         ida_simple_remove(&thermal_tz_ida, id);
1352 free_tz:
1353         kfree(tz);
1354         return ERR_PTR(result);
1355 }
1356 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1357
1358 /**
1359  * thermal_device_unregister - removes the registered thermal zone device
1360  * @tz: the thermal zone device to remove
1361  */
1362 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1363 {
1364         int i;
1365         const struct thermal_zone_params *tzp;
1366         struct thermal_cooling_device *cdev;
1367         struct thermal_zone_device *pos = NULL;
1368
1369         if (!tz)
1370                 return;
1371
1372         tzp = tz->tzp;
1373
1374         mutex_lock(&thermal_list_lock);
1375         list_for_each_entry(pos, &thermal_tz_list, node)
1376                 if (pos == tz)
1377                         break;
1378         if (pos != tz) {
1379                 /* thermal zone device not found */
1380                 mutex_unlock(&thermal_list_lock);
1381                 return;
1382         }
1383         list_del(&tz->node);
1384
1385         /* Unbind all cdevs associated with 'this' thermal zone */
1386         list_for_each_entry(cdev, &thermal_cdev_list, node) {
1387                 if (tz->ops->unbind) {
1388                         tz->ops->unbind(tz, cdev);
1389                         continue;
1390                 }
1391
1392                 if (!tzp || !tzp->tbp)
1393                         break;
1394
1395                 for (i = 0; i < tzp->num_tbps; i++) {
1396                         if (tzp->tbp[i].cdev == cdev) {
1397                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1398                                 tzp->tbp[i].cdev = NULL;
1399                         }
1400                 }
1401         }
1402
1403         mutex_unlock(&thermal_list_lock);
1404
1405         cancel_delayed_work_sync(&tz->poll_queue);
1406
1407         thermal_set_governor(tz, NULL);
1408
1409         thermal_remove_hwmon_sysfs(tz);
1410         ida_simple_remove(&thermal_tz_ida, tz->id);
1411         ida_destroy(&tz->ida);
1412         mutex_destroy(&tz->lock);
1413         device_unregister(&tz->device);
1414 }
1415 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1416
1417 /**
1418  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1419  * @name: thermal zone name to fetch the temperature
1420  *
1421  * When only one zone is found with the passed name, returns a reference to it.
1422  *
1423  * Return: On success returns a reference to an unique thermal zone with
1424  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1425  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1426  */
1427 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1428 {
1429         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1430         unsigned int found = 0;
1431
1432         if (!name)
1433                 goto exit;
1434
1435         mutex_lock(&thermal_list_lock);
1436         list_for_each_entry(pos, &thermal_tz_list, node)
1437                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1438                         found++;
1439                         ref = pos;
1440                 }
1441         mutex_unlock(&thermal_list_lock);
1442
1443         /* nothing has been found, thus an error code for it */
1444         if (found == 0)
1445                 ref = ERR_PTR(-ENODEV);
1446         else if (found > 1)
1447         /* Success only when an unique zone is found */
1448                 ref = ERR_PTR(-EEXIST);
1449
1450 exit:
1451         return ref;
1452 }
1453 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1454
1455 static int thermal_pm_notify(struct notifier_block *nb,
1456                              unsigned long mode, void *_unused)
1457 {
1458         struct thermal_zone_device *tz;
1459         enum thermal_device_mode tz_mode;
1460
1461         switch (mode) {
1462         case PM_HIBERNATION_PREPARE:
1463         case PM_RESTORE_PREPARE:
1464         case PM_SUSPEND_PREPARE:
1465                 atomic_set(&in_suspend, 1);
1466                 break;
1467         case PM_POST_HIBERNATION:
1468         case PM_POST_RESTORE:
1469         case PM_POST_SUSPEND:
1470                 atomic_set(&in_suspend, 0);
1471                 list_for_each_entry(tz, &thermal_tz_list, node) {
1472                         tz_mode = THERMAL_DEVICE_ENABLED;
1473                         if (tz->ops->get_mode)
1474                                 tz->ops->get_mode(tz, &tz_mode);
1475
1476                         if (tz_mode == THERMAL_DEVICE_DISABLED)
1477                                 continue;
1478
1479                         thermal_zone_device_init(tz);
1480                         thermal_zone_device_update(tz,
1481                                                    THERMAL_EVENT_UNSPECIFIED);
1482                 }
1483                 break;
1484         default:
1485                 break;
1486         }
1487         return 0;
1488 }
1489
1490 static struct notifier_block thermal_pm_nb = {
1491         .notifier_call = thermal_pm_notify,
1492 };
1493
1494 static int __init thermal_init(void)
1495 {
1496         int result;
1497
1498         mutex_init(&poweroff_lock);
1499         result = thermal_register_governors();
1500         if (result)
1501                 goto error;
1502
1503         result = class_register(&thermal_class);
1504         if (result)
1505                 goto unregister_governors;
1506
1507         result = of_parse_thermal_zones();
1508         if (result)
1509                 goto unregister_class;
1510
1511         result = register_pm_notifier(&thermal_pm_nb);
1512         if (result)
1513                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1514                         result);
1515
1516         return 0;
1517
1518 unregister_class:
1519         class_unregister(&thermal_class);
1520 unregister_governors:
1521         thermal_unregister_governors();
1522 error:
1523         ida_destroy(&thermal_tz_ida);
1524         ida_destroy(&thermal_cdev_ida);
1525         mutex_destroy(&thermal_list_lock);
1526         mutex_destroy(&thermal_governor_lock);
1527         mutex_destroy(&poweroff_lock);
1528         return result;
1529 }
1530 core_initcall(thermal_init);