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 /**
 565  * thermal_notify_framework - Sensor drivers use this API to notify framework
 566  * @tz:         thermal zone device
 567  * @trip:       indicates which trip point has been crossed
 568  *
 569  * This function handles the trip events from sensor drivers. It starts
 570  * throttling the cooling devices according to the policy configured.
 571  * For CRITICAL and HOT trip points, this notifies the respective drivers,
 572  * and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
 573  * The throttling policy is based on the configured platform data; if no
 574  * platform data is provided, this uses the step_wise throttling policy.
 575  */
 576 void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
 577 {
 578         handle_thermal_trip(tz, trip);
 579 }
 580 EXPORT_SYMBOL_GPL(thermal_notify_framework);
 581
 582 static void thermal_zone_device_check(struct work_struct *work)
 583 {
 584         struct thermal_zone_device *tz = container_of(work, struct
 585                                                       thermal_zone_device,
 586                                                       poll_queue.work);
 587         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 588 }
 589
 590 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 591                               void *data)
 592 {
 593         struct thermal_governor *gov;
 594         int ret = 0;
 595
 596         mutex_lock(&thermal_governor_lock);
 597         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 598                 ret = cb(gov, data);
 599                 if (ret)
 600                         break;
 601         }
 602         mutex_unlock(&thermal_governor_lock);
 603
 604         return ret;
 605 }
 606
 607 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 608                                               void *), void *data)
 609 {
 610         struct thermal_cooling_device *cdev;
 611         int ret = 0;
 612
 613         mutex_lock(&thermal_list_lock);
 614         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 615                 ret = cb(cdev, data);
 616                 if (ret)
 617                         break;
 618         }
 619         mutex_unlock(&thermal_list_lock);
 620
 621         return ret;
 622 }
 623
 624 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 625                           void *data)
 626 {
 627         struct thermal_zone_device *tz;
 628         int ret = 0;
 629
 630         mutex_lock(&thermal_list_lock);
 631         list_for_each_entry(tz, &thermal_tz_list, node) {
 632                 ret = cb(tz, data);
 633                 if (ret)
 634                         break;
 635         }
 636         mutex_unlock(&thermal_list_lock);
 637
 638         return ret;
 639 }
 640
 641 struct thermal_zone_device *thermal_zone_get_by_id(int id)
 642 {
 643         struct thermal_zone_device *tz, *match = NULL;
 644
 645         mutex_lock(&thermal_list_lock);
 646         list_for_each_entry(tz, &thermal_tz_list, node) {
 647                 if (tz->id == id) {
 648                         match = tz;
 649                         break;
 650                 }
 651         }
 652         mutex_unlock(&thermal_list_lock);
 653
 654         return match;
 655 }
 656
 657 /*
 658  * Device management section: cooling devices, zones devices, and binding
 659  *
 660  * Set of functions provided by the thermal core for:
 661  * - cooling devices lifecycle: registration, unregistration,
 662  *                              binding, and unbinding.
 663  * - thermal zone devices lifecycle: registration, unregistration,
 664  *                                   binding, and unbinding.
 665  */
 666
 667 /**
 668  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 669  * @tz:         pointer to struct thermal_zone_device
 670  * @trip:       indicates which trip point the cooling devices is
 671  *              associated with in this thermal zone.
 672  * @cdev:       pointer to struct thermal_cooling_device
 673  * @upper:      the Maximum cooling state for this trip point.
 674  *              THERMAL_NO_LIMIT means no upper limit,
 675  *              and the cooling device can be in max_state.
 676  * @lower:      the Minimum cooling state can be used for this trip point.
 677  *              THERMAL_NO_LIMIT means no lower limit,
 678  *              and the cooling device can be in cooling state 0.
 679  * @weight:     The weight of the cooling device to be bound to the
 680  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 681  *              default value
 682  *
 683  * This interface function bind a thermal cooling device to the certain trip
 684  * point of a thermal zone device.
 685  * This function is usually called in the thermal zone device .bind callback.
 686  *
 687  * Return: 0 on success, the proper error value otherwise.
 688  */
 689 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 690                                      int trip,
 691                                      struct thermal_cooling_device *cdev,
 692                                      unsigned long upper, unsigned long lower,
 693                                      unsigned int weight)
 694 {
 695         struct thermal_instance *dev;
 696         struct thermal_instance *pos;
 697         struct thermal_zone_device *pos1;
 698         struct thermal_cooling_device *pos2;
 699         unsigned long max_state;
 700         int result, ret;
 701
 702         if (trip >= tz->trips || trip < 0)
 703                 return -EINVAL;
 704
 705         list_for_each_entry(pos1, &thermal_tz_list, node) {
 706                 if (pos1 == tz)
 707                         break;
 708         }
 709         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 710                 if (pos2 == cdev)
 711                         break;
 712         }
 713
 714         if (tz != pos1 || cdev != pos2)
 715                 return -EINVAL;
 716
 717         ret = cdev->ops->get_max_state(cdev, &max_state);
 718         if (ret)
 719                 return ret;
 720
 721         /* lower default 0, upper default max_state */
 722         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 723         upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
 724
 725         if (lower > upper || upper > max_state)
 726                 return -EINVAL;
 727
 728         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 729         if (!dev)
 730                 return -ENOMEM;
 731         dev->tz = tz;
 732         dev->cdev = cdev;
 733         dev->trip = trip;
 734         dev->upper = upper;
 735         dev->lower = lower;
 736         dev->target = THERMAL_NO_TARGET;
 737         dev->weight = weight;
 738
 739         result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
 740         if (result < 0)
 741                 goto free_mem;
 742
 743         dev->id = result;
 744         sprintf(dev->name, "cdev%d", dev->id);
 745         result =
 746             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 747         if (result)
 748                 goto release_ida;
 749
 750         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 751         sysfs_attr_init(&dev->attr.attr);
 752         dev->attr.attr.name = dev->attr_name;
 753         dev->attr.attr.mode = 0444;
 754         dev->attr.show = trip_point_show;
 755         result = device_create_file(&tz->device, &dev->attr);
 756         if (result)
 757                 goto remove_symbol_link;
 758
 759         sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
 760         sysfs_attr_init(&dev->weight_attr.attr);
 761         dev->weight_attr.attr.name = dev->weight_attr_name;
 762         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 763         dev->weight_attr.show = weight_show;
 764         dev->weight_attr.store = weight_store;
 765         result = device_create_file(&tz->device, &dev->weight_attr);
 766         if (result)
 767                 goto remove_trip_file;
 768
 769         mutex_lock(&tz->lock);
 770         mutex_lock(&cdev->lock);
 771         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 772                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 773                         result = -EEXIST;
 774                         break;
 775                 }
 776         if (!result) {
 777                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 778                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 779                 atomic_set(&tz->need_update, 1);
 780         }
 781         mutex_unlock(&cdev->lock);
 782         mutex_unlock(&tz->lock);
 783
 784         if (!result)
 785                 return 0;
 786
 787         device_remove_file(&tz->device, &dev->weight_attr);
 788 remove_trip_file:
 789         device_remove_file(&tz->device, &dev->attr);
 790 remove_symbol_link:
 791         sysfs_remove_link(&tz->device.kobj, dev->name);
 792 release_ida:
 793         ida_simple_remove(&tz->ida, dev->id);
 794 free_mem:
 795         kfree(dev);
 796         return result;
 797 }
 798 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 799
 800 /**
 801  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 802  *                                        thermal zone.
 803  * @tz:         pointer to a struct thermal_zone_device.
 804  * @trip:       indicates which trip point the cooling devices is
 805  *              associated with in this thermal zone.
 806  * @cdev:       pointer to a struct thermal_cooling_device.
 807  *
 808  * This interface function unbind a thermal cooling device from the certain
 809  * trip point of a thermal zone device.
 810  * This function is usually called in the thermal zone device .unbind callback.
 811  *
 812  * Return: 0 on success, the proper error value otherwise.
 813  */
 814 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 815                                        int trip,
 816                                        struct thermal_cooling_device *cdev)
 817 {
 818         struct thermal_instance *pos, *next;
 819
 820         mutex_lock(&tz->lock);
 821         mutex_lock(&cdev->lock);
 822         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 823                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 824                         list_del(&pos->tz_node);
 825                         list_del(&pos->cdev_node);
 826                         mutex_unlock(&cdev->lock);
 827                         mutex_unlock(&tz->lock);
 828                         goto unbind;
 829                 }
 830         }
 831         mutex_unlock(&cdev->lock);
 832         mutex_unlock(&tz->lock);
 833
 834         return -ENODEV;
 835
 836 unbind:
 837         device_remove_file(&tz->device, &pos->weight_attr);
 838         device_remove_file(&tz->device, &pos->attr);
 839         sysfs_remove_link(&tz->device.kobj, pos->name);
 840         ida_simple_remove(&tz->ida, pos->id);
 841         kfree(pos);
 842         return 0;
 843 }
 844 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 845
 846 static void thermal_release(struct device *dev)
 847 {
 848         struct thermal_zone_device *tz;
 849         struct thermal_cooling_device *cdev;
 850
 851         if (!strncmp(dev_name(dev), "thermal_zone",
 852                      sizeof("thermal_zone") - 1)) {
 853                 tz = to_thermal_zone(dev);
 854                 thermal_zone_destroy_device_groups(tz);
 855                 kfree(tz);
 856         } else if (!strncmp(dev_name(dev), "cooling_device",
 857                             sizeof("cooling_device") - 1)) {
 858                 cdev = to_cooling_device(dev);
 859                 kfree(cdev);
 860         }
 861 }
 862
 863 static struct class thermal_class = {
 864         .name = "thermal",
 865         .dev_release = thermal_release,
 866 };
 867
 868 static inline
 869 void print_bind_err_msg(struct thermal_zone_device *tz,
 870                         struct thermal_cooling_device *cdev, int ret)
 871 {
 872         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
 873                 tz->type, cdev->type, ret);
 874 }
 875
 876 static void __bind(struct thermal_zone_device *tz, int mask,
 877                    struct thermal_cooling_device *cdev,
 878                    unsigned long *limits,
 879                    unsigned int weight)
 880 {
 881         int i, ret;
 882
 883         for (i = 0; i < tz->trips; i++) {
 884                 if (mask & (1 << i)) {
 885                         unsigned long upper, lower;
 886
 887                         upper = THERMAL_NO_LIMIT;
 888                         lower = THERMAL_NO_LIMIT;
 889                         if (limits) {
 890                                 lower = limits[i * 2];
 891                                 upper = limits[i * 2 + 1];
 892                         }
 893                         ret = thermal_zone_bind_cooling_device(tz, i, cdev,
 894                                                                upper, lower,
 895                                                                weight);
 896                         if (ret)
 897                                 print_bind_err_msg(tz, cdev, ret);
 898                 }
 899         }
 900 }
 901
 902 static void bind_cdev(struct thermal_cooling_device *cdev)
 903 {
 904         int i, ret;
 905         const struct thermal_zone_params *tzp;
 906         struct thermal_zone_device *pos = NULL;
 907
 908         mutex_lock(&thermal_list_lock);
 909
 910         list_for_each_entry(pos, &thermal_tz_list, node) {
 911                 if (!pos->tzp && !pos->ops->bind)
 912                         continue;
 913
 914                 if (pos->ops->bind) {
 915                         ret = pos->ops->bind(pos, cdev);
 916                         if (ret)
 917                                 print_bind_err_msg(pos, cdev, ret);
 918                         continue;
 919                 }
 920
 921                 tzp = pos->tzp;
 922                 if (!tzp || !tzp->tbp)
 923                         continue;
 924
 925                 for (i = 0; i < tzp->num_tbps; i++) {
 926                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
 927                                 continue;
 928                         if (tzp->tbp[i].match(pos, cdev))
 929                                 continue;
 930                         tzp->tbp[i].cdev = cdev;
 931                         __bind(pos, tzp->tbp[i].trip_mask, cdev,
 932                                tzp->tbp[i].binding_limits,
 933                                tzp->tbp[i].weight);
 934                 }
 935         }
 936
 937         mutex_unlock(&thermal_list_lock);
 938 }
 939
 940 /**
 941  * __thermal_cooling_device_register() - register a new thermal cooling device
 942  * @np:         a pointer to a device tree node.
 943  * @type:       the thermal cooling device type.
 944  * @devdata:    device private data.
 945  * @ops:                standard thermal cooling devices callbacks.
 946  *
 947  * This interface function adds a new thermal cooling device (fan/processor/...)
 948  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 949  * to all the thermal zone devices registered at the same time.
 950  * It also gives the opportunity to link the cooling device to a device tree
 951  * node, so that it can be bound to a thermal zone created out of device tree.
 952  *
 953  * Return: a pointer to the created struct thermal_cooling_device or an
 954  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 955  */
 956 static struct thermal_cooling_device *
 957 __thermal_cooling_device_register(struct device_node *np,
 958                                   const char *type, void *devdata,
 959                                   const struct thermal_cooling_device_ops *ops)
 960 {
 961         struct thermal_cooling_device *cdev;
 962         struct thermal_zone_device *pos = NULL;
 963         int result;
 964
 965         if (type && strlen(type) >= THERMAL_NAME_LENGTH)
 966                 return ERR_PTR(-EINVAL);
 967
 968         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
 969             !ops->set_cur_state)
 970                 return ERR_PTR(-EINVAL);
 971
 972         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 973         if (!cdev)
 974                 return ERR_PTR(-ENOMEM);
 975
 976         result = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
 977         if (result < 0) {
 978                 kfree(cdev);
 979                 return ERR_PTR(result);
 980         }
 981
 982         cdev->id = result;
 983         strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
 984         mutex_init(&cdev->lock);
 985         INIT_LIST_HEAD(&cdev->thermal_instances);
 986         cdev->np = np;
 987         cdev->ops = ops;
 988         cdev->updated = false;
 989         cdev->device.class = &thermal_class;
 990         cdev->devdata = devdata;
 991         thermal_cooling_device_setup_sysfs(cdev);
 992         dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
 993         result = device_register(&cdev->device);
 994         if (result) {
 995                 ida_simple_remove(&thermal_cdev_ida, cdev->id);
 996                 put_device(&cdev->device);
 997                 return ERR_PTR(result);
 998         }
 999
1000         /* Add 'this' new cdev to the global cdev list */
1001         mutex_lock(&thermal_list_lock);
1002         list_add(&cdev->node, &thermal_cdev_list);
1003         mutex_unlock(&thermal_list_lock);
1004
1005         /* Update binding information for 'this' new cdev */
1006         bind_cdev(cdev);
1007
1008         mutex_lock(&thermal_list_lock);
1009         list_for_each_entry(pos, &thermal_tz_list, node)
1010                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
1011                         thermal_zone_device_update(pos,
1012                                                    THERMAL_EVENT_UNSPECIFIED);
1013         mutex_unlock(&thermal_list_lock);
1014
1015         return cdev;
1016 }
1017
1018 /**
1019  * thermal_cooling_device_register() - register a new thermal cooling device
1020  * @type:       the thermal cooling device type.
1021  * @devdata:    device private data.
1022  * @ops:                standard thermal cooling devices callbacks.
1023  *
1024  * This interface function adds a new thermal cooling device (fan/processor/...)
1025  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1026  * to all the thermal zone devices registered at the same time.
1027  *
1028  * Return: a pointer to the created struct thermal_cooling_device or an
1029  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1030  */
1031 struct thermal_cooling_device *
1032 thermal_cooling_device_register(const char *type, void *devdata,
1033                                 const struct thermal_cooling_device_ops *ops)
1034 {
1035         return __thermal_cooling_device_register(NULL, type, devdata, ops);
1036 }
1037 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1038
1039 /**
1040  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1041  * @np:         a pointer to a device tree node.
1042  * @type:       the thermal cooling device type.
1043  * @devdata:    device private data.
1044  * @ops:                standard thermal cooling devices callbacks.
1045  *
1046  * This function will register a cooling device with device tree node reference.
1047  * This interface function adds a new thermal cooling device (fan/processor/...)
1048  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1049  * to all the thermal zone devices registered at the same time.
1050  *
1051  * Return: a pointer to the created struct thermal_cooling_device or an
1052  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1053  */
1054 struct thermal_cooling_device *
1055 thermal_of_cooling_device_register(struct device_node *np,
1056                                    const char *type, void *devdata,
1057                                    const struct thermal_cooling_device_ops *ops)
1058 {
1059         return __thermal_cooling_device_register(np, type, devdata, ops);
1060 }
1061 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1062
1063 static void thermal_cooling_device_release(struct device *dev, void *res)
1064 {
1065         thermal_cooling_device_unregister(
1066                                 *(struct thermal_cooling_device **)res);
1067 }
1068
1069 /**
1070  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1071  *                                             device
1072  * @dev:        a valid struct device pointer of a sensor device.
1073  * @np:         a pointer to a device tree node.
1074  * @type:       the thermal cooling device type.
1075  * @devdata:    device private data.
1076  * @ops:        standard thermal cooling devices callbacks.
1077  *
1078  * This function will register a cooling device with device tree node reference.
1079  * This interface function adds a new thermal cooling device (fan/processor/...)
1080  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1081  * to all the thermal zone devices registered at the same time.
1082  *
1083  * Return: a pointer to the created struct thermal_cooling_device or an
1084  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1085  */
1086 struct thermal_cooling_device *
1087 devm_thermal_of_cooling_device_register(struct device *dev,
1088                                 struct device_node *np,
1089                                 char *type, void *devdata,
1090                                 const struct thermal_cooling_device_ops *ops)
1091 {
1092         struct thermal_cooling_device **ptr, *tcd;
1093
1094         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1095                            GFP_KERNEL);
1096         if (!ptr)
1097                 return ERR_PTR(-ENOMEM);
1098
1099         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1100         if (IS_ERR(tcd)) {
1101                 devres_free(ptr);
1102                 return tcd;
1103         }
1104
1105         *ptr = tcd;
1106         devres_add(dev, ptr);
1107
1108         return tcd;
1109 }
1110 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1111
1112 static void __unbind(struct thermal_zone_device *tz, int mask,
1113                      struct thermal_cooling_device *cdev)
1114 {
1115         int i;
1116
1117         for (i = 0; i < tz->trips; i++)
1118                 if (mask & (1 << i))
1119                         thermal_zone_unbind_cooling_device(tz, i, cdev);
1120 }
1121
1122 /**
1123  * thermal_cooling_device_unregister - removes a thermal cooling device
1124  * @cdev:       the thermal cooling device to remove.
1125  *
1126  * thermal_cooling_device_unregister() must be called when a registered
1127  * thermal cooling device is no longer needed.
1128  */
1129 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1130 {
1131         int i;
1132         const struct thermal_zone_params *tzp;
1133         struct thermal_zone_device *tz;
1134         struct thermal_cooling_device *pos = NULL;
1135
1136         if (!cdev)
1137                 return;
1138
1139         mutex_lock(&thermal_list_lock);
1140         list_for_each_entry(pos, &thermal_cdev_list, node)
1141                 if (pos == cdev)
1142                         break;
1143         if (pos != cdev) {
1144                 /* thermal cooling device not found */
1145                 mutex_unlock(&thermal_list_lock);
1146                 return;
1147         }
1148         list_del(&cdev->node);
1149
1150         /* Unbind all thermal zones associated with 'this' cdev */
1151         list_for_each_entry(tz, &thermal_tz_list, node) {
1152                 if (tz->ops->unbind) {
1153                         tz->ops->unbind(tz, cdev);
1154                         continue;
1155                 }
1156
1157                 if (!tz->tzp || !tz->tzp->tbp)
1158                         continue;
1159
1160                 tzp = tz->tzp;
1161                 for (i = 0; i < tzp->num_tbps; i++) {
1162                         if (tzp->tbp[i].cdev == cdev) {
1163                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1164                                 tzp->tbp[i].cdev = NULL;
1165                         }
1166                 }
1167         }
1168
1169         mutex_unlock(&thermal_list_lock);
1170
1171         ida_simple_remove(&thermal_cdev_ida, cdev->id);
1172         device_del(&cdev->device);
1173         thermal_cooling_device_destroy_sysfs(cdev);
1174         put_device(&cdev->device);
1175 }
1176 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1177
1178 static void bind_tz(struct thermal_zone_device *tz)
1179 {
1180         int i, ret;
1181         struct thermal_cooling_device *pos = NULL;
1182         const struct thermal_zone_params *tzp = tz->tzp;
1183
1184         if (!tzp && !tz->ops->bind)
1185                 return;
1186
1187         mutex_lock(&thermal_list_lock);
1188
1189         /* If there is ops->bind, try to use ops->bind */
1190         if (tz->ops->bind) {
1191                 list_for_each_entry(pos, &thermal_cdev_list, node) {
1192                         ret = tz->ops->bind(tz, pos);
1193                         if (ret)
1194                                 print_bind_err_msg(tz, pos, ret);
1195                 }
1196                 goto exit;
1197         }
1198
1199         if (!tzp || !tzp->tbp)
1200                 goto exit;
1201
1202         list_for_each_entry(pos, &thermal_cdev_list, node) {
1203                 for (i = 0; i < tzp->num_tbps; i++) {
1204                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1205                                 continue;
1206                         if (tzp->tbp[i].match(tz, pos))
1207                                 continue;
1208                         tzp->tbp[i].cdev = pos;
1209                         __bind(tz, tzp->tbp[i].trip_mask, pos,
1210                                tzp->tbp[i].binding_limits,
1211                                tzp->tbp[i].weight);
1212                 }
1213         }
1214 exit:
1215         mutex_unlock(&thermal_list_lock);
1216 }
1217
1218 /**
1219  * thermal_zone_device_register() - register a new thermal zone device
1220  * @type:       the thermal zone device type
1221  * @trips:      the number of trip points the thermal zone support
1222  * @mask:       a bit string indicating the writeablility of trip points
1223  * @devdata:    private device data
1224  * @ops:        standard thermal zone device callbacks
1225  * @tzp:        thermal zone platform parameters
1226  * @passive_delay: number of milliseconds to wait between polls when
1227  *                 performing passive cooling
1228  * @polling_delay: number of milliseconds to wait between polls when checking
1229  *                 whether trip points have been crossed (0 for interrupt
1230  *                 driven systems)
1231  *
1232  * This interface function adds a new thermal zone device (sensor) to
1233  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1234  * thermal cooling devices registered at the same time.
1235  * thermal_zone_device_unregister() must be called when the device is no
1236  * longer needed. The passive cooling depends on the .get_trend() return value.
1237  *
1238  * Return: a pointer to the created struct thermal_zone_device or an
1239  * in case of error, an ERR_PTR. Caller must check return value with
1240  * IS_ERR*() helpers.
1241  */
1242 struct thermal_zone_device *
1243 thermal_zone_device_register(const char *type, int trips, int mask,
1244                              void *devdata, struct thermal_zone_device_ops *ops,
1245                              struct thermal_zone_params *tzp, int passive_delay,
1246                              int polling_delay)
1247 {
1248         struct thermal_zone_device *tz;
1249         enum thermal_trip_type trip_type;
1250         int trip_temp;
1251         int id;
1252         int result;
1253         int count;
1254         struct thermal_governor *governor;
1255
1256         if (!type || strlen(type) == 0) {
1257                 pr_err("Error: No thermal zone type defined\n");
1258                 return ERR_PTR(-EINVAL);
1259         }
1260
1261         if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
1262                 pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
1263                        type, THERMAL_NAME_LENGTH);
1264                 return ERR_PTR(-EINVAL);
1265         }
1266
1267         if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
1268                 pr_err("Error: Incorrect number of thermal trips\n");
1269                 return ERR_PTR(-EINVAL);
1270         }
1271
1272         if (!ops) {
1273                 pr_err("Error: Thermal zone device ops not defined\n");
1274                 return ERR_PTR(-EINVAL);
1275         }
1276
1277         if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1278                 return ERR_PTR(-EINVAL);
1279
1280         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1281         if (!tz)
1282                 return ERR_PTR(-ENOMEM);
1283
1284         INIT_LIST_HEAD(&tz->thermal_instances);
1285         ida_init(&tz->ida);
1286         mutex_init(&tz->lock);
1287         id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1288         if (id < 0) {
1289                 result = id;
1290                 goto free_tz;
1291         }
1292
1293         tz->id = id;
1294         strlcpy(tz->type, type, sizeof(tz->type));
1295
1296         if (!ops->critical)
1297                 ops->critical = thermal_zone_device_critical;
1298
1299         tz->ops = ops;
1300         tz->tzp = tzp;
1301         tz->device.class = &thermal_class;
1302         tz->devdata = devdata;
1303         tz->trips = trips;
1304
1305         thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1306         thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1307
1308         /* sys I/F */
1309         /* Add nodes that are always present via .groups */
1310         result = thermal_zone_create_device_groups(tz, mask);
1311         if (result)
1312                 goto remove_id;
1313
1314         /* A new thermal zone needs to be updated anyway. */
1315         atomic_set(&tz->need_update, 1);
1316
1317         dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1318         result = device_register(&tz->device);
1319         if (result)
1320                 goto release_device;
1321
1322         for (count = 0; count < trips; count++) {
1323                 if (tz->ops->get_trip_type(tz, count, &trip_type) ||
1324                     tz->ops->get_trip_temp(tz, count, &trip_temp) ||
1325                     !trip_temp)
1326                         set_bit(count, &tz->trips_disabled);
1327         }
1328
1329         /* Update 'this' zone's governor information */
1330         mutex_lock(&thermal_governor_lock);
1331
1332         if (tz->tzp)
1333                 governor = __find_governor(tz->tzp->governor_name);
1334         else
1335                 governor = def_governor;
1336
1337         result = thermal_set_governor(tz, governor);
1338         if (result) {
1339                 mutex_unlock(&thermal_governor_lock);
1340                 goto unregister;
1341         }
1342
1343         mutex_unlock(&thermal_governor_lock);
1344
1345         if (!tz->tzp || !tz->tzp->no_hwmon) {
1346                 result = thermal_add_hwmon_sysfs(tz);
1347                 if (result)
1348                         goto unregister;
1349         }
1350
1351         mutex_lock(&thermal_list_lock);
1352         list_add_tail(&tz->node, &thermal_tz_list);
1353         mutex_unlock(&thermal_list_lock);
1354
1355         /* Bind cooling devices for this zone */
1356         bind_tz(tz);
1357
1358         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1359
1360         thermal_zone_device_init(tz);
1361         /* Update the new thermal zone and mark it as already updated. */
1362         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1363                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1364
1365         thermal_notify_tz_create(tz->id, tz->type);
1366
1367         return tz;
1368
1369 unregister:
1370         device_del(&tz->device);
1371 release_device:
1372         put_device(&tz->device);
1373         tz = NULL;
1374 remove_id:
1375         ida_simple_remove(&thermal_tz_ida, id);
1376 free_tz:
1377         kfree(tz);
1378         return ERR_PTR(result);
1379 }
1380 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1381
1382 /**
1383  * thermal_device_unregister - removes the registered thermal zone device
1384  * @tz: the thermal zone device to remove
1385  */
1386 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1387 {
1388         int i, tz_id;
1389         const struct thermal_zone_params *tzp;
1390         struct thermal_cooling_device *cdev;
1391         struct thermal_zone_device *pos = NULL;
1392
1393         if (!tz)
1394                 return;
1395
1396         tzp = tz->tzp;
1397         tz_id = tz->id;
1398
1399         mutex_lock(&thermal_list_lock);
1400         list_for_each_entry(pos, &thermal_tz_list, node)
1401                 if (pos == tz)
1402                         break;
1403         if (pos != tz) {
1404                 /* thermal zone device not found */
1405                 mutex_unlock(&thermal_list_lock);
1406                 return;
1407         }
1408         list_del(&tz->node);
1409
1410         /* Unbind all cdevs associated with 'this' thermal zone */
1411         list_for_each_entry(cdev, &thermal_cdev_list, node) {
1412                 if (tz->ops->unbind) {
1413                         tz->ops->unbind(tz, cdev);
1414                         continue;
1415                 }
1416
1417                 if (!tzp || !tzp->tbp)
1418                         break;
1419
1420                 for (i = 0; i < tzp->num_tbps; i++) {
1421                         if (tzp->tbp[i].cdev == cdev) {
1422                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1423                                 tzp->tbp[i].cdev = NULL;
1424                         }
1425                 }
1426         }
1427
1428         mutex_unlock(&thermal_list_lock);
1429
1430         cancel_delayed_work_sync(&tz->poll_queue);
1431
1432         thermal_set_governor(tz, NULL);
1433
1434         thermal_remove_hwmon_sysfs(tz);
1435         ida_simple_remove(&thermal_tz_ida, tz->id);
1436         ida_destroy(&tz->ida);
1437         mutex_destroy(&tz->lock);
1438         device_unregister(&tz->device);
1439
1440         thermal_notify_tz_delete(tz_id);
1441 }
1442 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1443
1444 /**
1445  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1446  * @name: thermal zone name to fetch the temperature
1447  *
1448  * When only one zone is found with the passed name, returns a reference to it.
1449  *
1450  * Return: On success returns a reference to an unique thermal zone with
1451  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1452  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1453  */
1454 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1455 {
1456         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1457         unsigned int found = 0;
1458
1459         if (!name)
1460                 goto exit;
1461
1462         mutex_lock(&thermal_list_lock);
1463         list_for_each_entry(pos, &thermal_tz_list, node)
1464                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1465                         found++;
1466                         ref = pos;
1467                 }
1468         mutex_unlock(&thermal_list_lock);
1469
1470         /* nothing has been found, thus an error code for it */
1471         if (found == 0)
1472                 ref = ERR_PTR(-ENODEV);
1473         else if (found > 1)
1474         /* Success only when an unique zone is found */
1475                 ref = ERR_PTR(-EEXIST);
1476
1477 exit:
1478         return ref;
1479 }
1480 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1481
1482 static int thermal_pm_notify(struct notifier_block *nb,
1483                              unsigned long mode, void *_unused)
1484 {
1485         struct thermal_zone_device *tz;
1486
1487         switch (mode) {
1488         case PM_HIBERNATION_PREPARE:
1489         case PM_RESTORE_PREPARE:
1490         case PM_SUSPEND_PREPARE:
1491                 atomic_set(&in_suspend, 1);
1492                 break;
1493         case PM_POST_HIBERNATION:
1494         case PM_POST_RESTORE:
1495         case PM_POST_SUSPEND:
1496                 atomic_set(&in_suspend, 0);
1497                 list_for_each_entry(tz, &thermal_tz_list, node) {
1498                         if (!thermal_zone_device_is_enabled(tz))
1499                                 continue;
1500
1501                         thermal_zone_device_init(tz);
1502                         thermal_zone_device_update(tz,
1503                                                    THERMAL_EVENT_UNSPECIFIED);
1504                 }
1505                 break;
1506         default:
1507                 break;
1508         }
1509         return 0;
1510 }
1511
1512 static struct notifier_block thermal_pm_nb = {
1513         .notifier_call = thermal_pm_notify,
1514 };
1515
1516 static int __init thermal_init(void)
1517 {
1518         int result;
1519
1520         result = thermal_netlink_init();
1521         if (result)
1522                 goto error;
1523
1524         result = thermal_register_governors();
1525         if (result)
1526                 goto error;
1527
1528         result = class_register(&thermal_class);
1529         if (result)
1530                 goto unregister_governors;
1531
1532         result = of_parse_thermal_zones();
1533         if (result)
1534                 goto unregister_class;
1535
1536         result = register_pm_notifier(&thermal_pm_nb);
1537         if (result)
1538                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1539                         result);
1540
1541         return 0;
1542
1543 unregister_class:
1544         class_unregister(&thermal_class);
1545 unregister_governors:
1546         thermal_unregister_governors();
1547 error:
1548         ida_destroy(&thermal_tz_ida);
1549         ida_destroy(&thermal_cdev_ida);
1550         mutex_destroy(&thermal_list_lock);
1551         mutex_destroy(&thermal_governor_lock);
1552         mutex_destroy(&poweroff_lock);
1553         return result;
1554 }
1555 postcore_initcall(thermal_init);