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
 228         mutex_lock(&thermal_governor_lock);
 229
 230         list_for_each_entry(pos, &thermal_governor_list, governor_list) {
 231                 count += scnprintf(buf + count, PAGE_SIZE - count, "%s ",
 232                                    pos->name);
 233         }
 234         count += scnprintf(buf + count, PAGE_SIZE - count, "\n");
 235
 236         mutex_unlock(&thermal_governor_lock);
 237
 238         return count;
 239 }
 240
 241 static void __init thermal_unregister_governors(void)
 242 {
 243         struct thermal_governor **governor;
 244
 245         for_each_governor_table(governor)
 246                 thermal_unregister_governor(*governor);
 247 }
 248
 249 static int __init thermal_register_governors(void)
 250 {
 251         int ret = 0;
 252         struct thermal_governor **governor;
 253
 254         for_each_governor_table(governor) {
 255                 ret = thermal_register_governor(*governor);
 256                 if (ret) {
 257                         pr_err("Failed to register governor: '%s'",
 258                                (*governor)->name);
 259                         break;
 260                 }
 261
 262                 pr_info("Registered thermal governor '%s'",
 263                         (*governor)->name);
 264         }
 265
 266         if (ret) {
 267                 struct thermal_governor **gov;
 268
 269                 for_each_governor_table(gov) {
 270                         if (gov == governor)
 271                                 break;
 272                         thermal_unregister_governor(*gov);
 273                 }
 274         }
 275
 276         return ret;
 277 }
 278
 279 /*
 280  * Zone update section: main control loop applied to each zone while monitoring
 281  *
 282  * in polling mode. The monitoring is done using a workqueue.
 283  * Same update may be done on a zone by calling thermal_zone_device_update().
 284  *
 285  * An update means:
 286  * - Non-critical trips will invoke the governor responsible for that zone;
 287  * - Hot trips will produce a notification to userspace;
 288  * - Critical trip point will cause a system shutdown.
 289  */
 290 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 291                                             int delay)
 292 {
 293         if (delay > 1000)
 294                 mod_delayed_work(system_freezable_power_efficient_wq,
 295                                  &tz->poll_queue,
 296                                  round_jiffies(msecs_to_jiffies(delay)));
 297         else if (delay)
 298                 mod_delayed_work(system_freezable_power_efficient_wq,
 299                                  &tz->poll_queue,
 300                                  msecs_to_jiffies(delay));
 301         else
 302                 cancel_delayed_work(&tz->poll_queue);
 303 }
 304
 305 static inline bool should_stop_polling(struct thermal_zone_device *tz)
 306 {
 307         return !thermal_zone_device_is_enabled(tz);
 308 }
 309
 310 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 311 {
 312         bool stop;
 313
 314         stop = should_stop_polling(tz);
 315
 316         mutex_lock(&tz->lock);
 317
 318         if (!stop && tz->passive)
 319                 thermal_zone_device_set_polling(tz, tz->passive_delay);
 320         else if (!stop && tz->polling_delay)
 321                 thermal_zone_device_set_polling(tz, tz->polling_delay);
 322         else
 323                 thermal_zone_device_set_polling(tz, 0);
 324
 325         mutex_unlock(&tz->lock);
 326 }
 327
 328 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 329 {
 330         tz->governor ? tz->governor->throttle(tz, trip) :
 331                        def_governor->throttle(tz, trip);
 332 }
 333
 334 /**
 335  * thermal_emergency_poweroff_func - emergency poweroff work after a known delay
 336  * @work: work_struct associated with the emergency poweroff function
 337  *
 338  * This function is called in very critical situations to force
 339  * a kernel poweroff after a configurable timeout value.
 340  */
 341 static void thermal_emergency_poweroff_func(struct work_struct *work)
 342 {
 343         /*
 344          * We have reached here after the emergency thermal shutdown
 345          * Waiting period has expired. This means orderly_poweroff has
 346          * not been able to shut off the system for some reason.
 347          * Try to shut down the system immediately using kernel_power_off
 348          * if populated
 349          */
 350         WARN(1, "Attempting kernel_power_off: Temperature too high\n");
 351         kernel_power_off();
 352
 353         /*
 354          * Worst of the worst case trigger emergency restart
 355          */
 356         WARN(1, "Attempting emergency_restart: Temperature too high\n");
 357         emergency_restart();
 358 }
 359
 360 static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work,
 361                             thermal_emergency_poweroff_func);
 362
 363 /**
 364  * thermal_emergency_poweroff - Trigger an emergency system poweroff
 365  *
 366  * This may be called from any critical situation to trigger a system shutdown
 367  * after a known period of time. By default this is not scheduled.
 368  */
 369 static void thermal_emergency_poweroff(void)
 370 {
 371         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 372         /*
 373          * poweroff_delay_ms must be a carefully profiled positive value.
 374          * Its a must for thermal_emergency_poweroff_work to be scheduled
 375          */
 376         if (poweroff_delay_ms <= 0)
 377                 return;
 378         schedule_delayed_work(&thermal_emergency_poweroff_work,
 379                               msecs_to_jiffies(poweroff_delay_ms));
 380 }
 381
 382 static void handle_critical_trips(struct thermal_zone_device *tz,
 383                                   int trip, enum thermal_trip_type trip_type)
 384 {
 385         int trip_temp;
 386
 387         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 388
 389         /* If we have not crossed the trip_temp, we do not care. */
 390         if (trip_temp <= 0 || tz->temperature < trip_temp)
 391                 return;
 392
 393         trace_thermal_zone_trip(tz, trip, trip_type);
 394
 395         if (tz->ops->notify)
 396                 tz->ops->notify(tz, trip, trip_type);
 397
 398         if (trip_type == THERMAL_TRIP_CRITICAL) {
 399                 dev_emerg(&tz->device,
 400                           "critical temperature reached (%d C), shutting down\n",
 401                           tz->temperature / 1000);
 402                 mutex_lock(&poweroff_lock);
 403                 if (!power_off_triggered) {
 404                         /*
 405                          * Queue a backup emergency shutdown in the event of
 406                          * orderly_poweroff failure
 407                          */
 408                         thermal_emergency_poweroff();
 409                         orderly_poweroff(true);
 410                         power_off_triggered = true;
 411                 }
 412                 mutex_unlock(&poweroff_lock);
 413         }
 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         tz->prev_low_trip = -INT_MAX;
 478         tz->prev_high_trip = INT_MAX;
 479         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 480                 pos->initialized = false;
 481 }
 482
 483 static void thermal_zone_device_reset(struct thermal_zone_device *tz)
 484 {
 485         tz->passive = 0;
 486         thermal_zone_device_init(tz);
 487 }
 488
 489 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 490                                         enum thermal_device_mode mode)
 491 {
 492         int ret = 0;
 493
 494         mutex_lock(&tz->lock);
 495
 496         /* do nothing if mode isn't changing */
 497         if (mode == tz->mode) {
 498                 mutex_unlock(&tz->lock);
 499
 500                 return ret;
 501         }
 502
 503         if (tz->ops->change_mode)
 504                 ret = tz->ops->change_mode(tz, mode);
 505
 506         if (!ret)
 507                 tz->mode = mode;
 508
 509         mutex_unlock(&tz->lock);
 510
 511         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 512
 513         if (mode == THERMAL_DEVICE_ENABLED)
 514                 thermal_notify_tz_enable(tz->id);
 515         else
 516                 thermal_notify_tz_disable(tz->id);
 517
 518         return ret;
 519 }
 520
 521 int thermal_zone_device_enable(struct thermal_zone_device *tz)
 522 {
 523         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
 524 }
 525 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
 526
 527 int thermal_zone_device_disable(struct thermal_zone_device *tz)
 528 {
 529         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 530 }
 531 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 532
 533 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
 534 {
 535         enum thermal_device_mode mode;
 536
 537         mutex_lock(&tz->lock);
 538
 539         mode = tz->mode;
 540
 541         mutex_unlock(&tz->lock);
 542
 543         return mode == THERMAL_DEVICE_ENABLED;
 544 }
 545
 546 void thermal_zone_device_update(struct thermal_zone_device *tz,
 547                                 enum thermal_notify_event event)
 548 {
 549         int count;
 550
 551         if (should_stop_polling(tz))
 552                 return;
 553
 554         if (atomic_read(&in_suspend))
 555                 return;
 556
 557         if (!tz->ops->get_temp)
 558                 return;
 559
 560         update_temperature(tz);
 561
 562         thermal_zone_set_trips(tz);
 563
 564         tz->notify_event = event;
 565
 566         for (count = 0; count < tz->trips; count++)
 567                 handle_thermal_trip(tz, count);
 568 }
 569 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 570
 571 /**
 572  * thermal_notify_framework - Sensor drivers use this API to notify framework
 573  * @tz:         thermal zone device
 574  * @trip:       indicates which trip point has been crossed
 575  *
 576  * This function handles the trip events from sensor drivers. It starts
 577  * throttling the cooling devices according to the policy configured.
 578  * For CRITICAL and HOT trip points, this notifies the respective drivers,
 579  * and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
 580  * The throttling policy is based on the configured platform data; if no
 581  * platform data is provided, this uses the step_wise throttling policy.
 582  */
 583 void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
 584 {
 585         handle_thermal_trip(tz, trip);
 586 }
 587 EXPORT_SYMBOL_GPL(thermal_notify_framework);
 588
 589 static void thermal_zone_device_check(struct work_struct *work)
 590 {
 591         struct thermal_zone_device *tz = container_of(work, struct
 592                                                       thermal_zone_device,
 593                                                       poll_queue.work);
 594         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 595 }
 596
 597 /*
 598  * Power actor section: interface to power actors to estimate power
 599  *
 600  * Set of functions used to interact to cooling devices that know
 601  * how to estimate their devices power consumption.
 602  */
 603
 604 /**
 605  * power_actor_get_max_power() - get the maximum power that a cdev can consume
 606  * @cdev:       pointer to &thermal_cooling_device
 607  * @max_power:  pointer in which to store the maximum power
 608  *
 609  * Calculate the maximum power consumption in milliwats that the
 610  * cooling device can currently consume and store it in @max_power.
 611  *
 612  * Return: 0 on success, -EINVAL if @cdev doesn't support the
 613  * power_actor API or -E* on other error.
 614  */
 615 int power_actor_get_max_power(struct thermal_cooling_device *cdev,
 616                               u32 *max_power)
 617 {
 618         if (!cdev_is_power_actor(cdev))
 619                 return -EINVAL;
 620
 621         return cdev->ops->state2power(cdev, 0, max_power);
 622 }
 623
 624 /**
 625  * power_actor_get_min_power() - get the mainimum power that a cdev can consume
 626  * @cdev:       pointer to &thermal_cooling_device
 627  * @min_power:  pointer in which to store the minimum power
 628  *
 629  * Calculate the minimum power consumption in milliwatts that the
 630  * cooling device can currently consume and store it in @min_power.
 631  *
 632  * Return: 0 on success, -EINVAL if @cdev doesn't support the
 633  * power_actor API or -E* on other error.
 634  */
 635 int power_actor_get_min_power(struct thermal_cooling_device *cdev,
 636                               u32 *min_power)
 637 {
 638         unsigned long max_state;
 639         int ret;
 640
 641         if (!cdev_is_power_actor(cdev))
 642                 return -EINVAL;
 643
 644         ret = cdev->ops->get_max_state(cdev, &max_state);
 645         if (ret)
 646                 return ret;
 647
 648         return cdev->ops->state2power(cdev, max_state, min_power);
 649 }
 650
 651 /**
 652  * power_actor_set_power() - limit the maximum power a cooling device consumes
 653  * @cdev:       pointer to &thermal_cooling_device
 654  * @instance:   thermal instance to update
 655  * @power:      the power in milliwatts
 656  *
 657  * Set the cooling device to consume at most @power milliwatts. The limit is
 658  * expected to be a cap at the maximum power consumption.
 659  *
 660  * Return: 0 on success, -EINVAL if the cooling device does not
 661  * implement the power actor API or -E* for other failures.
 662  */
 663 int power_actor_set_power(struct thermal_cooling_device *cdev,
 664                           struct thermal_instance *instance, u32 power)
 665 {
 666         unsigned long state;
 667         int ret;
 668
 669         if (!cdev_is_power_actor(cdev))
 670                 return -EINVAL;
 671
 672         ret = cdev->ops->power2state(cdev, power, &state);
 673         if (ret)
 674                 return ret;
 675
 676         instance->target = state;
 677         mutex_lock(&cdev->lock);
 678         cdev->updated = false;
 679         mutex_unlock(&cdev->lock);
 680         thermal_cdev_update(cdev);
 681
 682         return 0;
 683 }
 684
 685 void thermal_zone_device_rebind_exception(struct thermal_zone_device *tz,
 686                                           const char *cdev_type, size_t size)
 687 {
 688         struct thermal_cooling_device *cdev = NULL;
 689
 690         mutex_lock(&thermal_list_lock);
 691         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 692                 /* skip non matching cdevs */
 693                 if (strncmp(cdev_type, cdev->type, size))
 694                         continue;
 695
 696                 /* re binding the exception matching the type pattern */
 697                 thermal_zone_bind_cooling_device(tz, THERMAL_TRIPS_NONE, cdev,
 698                                                  THERMAL_NO_LIMIT,
 699                                                  THERMAL_NO_LIMIT,
 700                                                  THERMAL_WEIGHT_DEFAULT);
 701         }
 702         mutex_unlock(&thermal_list_lock);
 703 }
 704
 705 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 706                               void *data)
 707 {
 708         struct thermal_governor *gov;
 709         int ret = 0;
 710
 711         mutex_lock(&thermal_governor_lock);
 712         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 713                 ret = cb(gov, data);
 714                 if (ret)
 715                         break;
 716         }
 717         mutex_unlock(&thermal_governor_lock);
 718
 719         return ret;
 720 }
 721
 722 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 723                                               void *), void *data)
 724 {
 725         struct thermal_cooling_device *cdev;
 726         int ret = 0;
 727
 728         mutex_lock(&thermal_list_lock);
 729         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 730                 ret = cb(cdev, data);
 731                 if (ret)
 732                         break;
 733         }
 734         mutex_unlock(&thermal_list_lock);
 735
 736         return ret;
 737 }
 738
 739 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 740                           void *data)
 741 {
 742         struct thermal_zone_device *tz;
 743         int ret = 0;
 744
 745         mutex_lock(&thermal_list_lock);
 746         list_for_each_entry(tz, &thermal_tz_list, node) {
 747                 ret = cb(tz, data);
 748                 if (ret)
 749                         break;
 750         }
 751         mutex_unlock(&thermal_list_lock);
 752
 753         return ret;
 754 }
 755
 756 struct thermal_zone_device *thermal_zone_get_by_id(int id)
 757 {
 758         struct thermal_zone_device *tz, *match = NULL;
 759
 760         mutex_lock(&thermal_list_lock);
 761         list_for_each_entry(tz, &thermal_tz_list, node) {
 762                 if (tz->id == id) {
 763                         match = tz;
 764                         break;
 765                 }
 766         }
 767         mutex_unlock(&thermal_list_lock);
 768
 769         return match;
 770 }
 771
 772 void thermal_zone_device_unbind_exception(struct thermal_zone_device *tz,
 773                                           const char *cdev_type, size_t size)
 774 {
 775         struct thermal_cooling_device *cdev = NULL;
 776
 777         mutex_lock(&thermal_list_lock);
 778         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 779                 /* skip non matching cdevs */
 780                 if (strncmp(cdev_type, cdev->type, size))
 781                         continue;
 782                 /* unbinding the exception matching the type pattern */
 783                 thermal_zone_unbind_cooling_device(tz, THERMAL_TRIPS_NONE,
 784                                                    cdev);
 785         }
 786         mutex_unlock(&thermal_list_lock);
 787 }
 788
 789 /*
 790  * Device management section: cooling devices, zones devices, and binding
 791  *
 792  * Set of functions provided by the thermal core for:
 793  * - cooling devices lifecycle: registration, unregistration,
 794  *                              binding, and unbinding.
 795  * - thermal zone devices lifecycle: registration, unregistration,
 796  *                                   binding, and unbinding.
 797  */
 798
 799 /**
 800  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 801  * @tz:         pointer to struct thermal_zone_device
 802  * @trip:       indicates which trip point the cooling devices is
 803  *              associated with in this thermal zone.
 804  * @cdev:       pointer to struct thermal_cooling_device
 805  * @upper:      the Maximum cooling state for this trip point.
 806  *              THERMAL_NO_LIMIT means no upper limit,
 807  *              and the cooling device can be in max_state.
 808  * @lower:      the Minimum cooling state can be used for this trip point.
 809  *              THERMAL_NO_LIMIT means no lower limit,
 810  *              and the cooling device can be in cooling state 0.
 811  * @weight:     The weight of the cooling device to be bound to the
 812  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 813  *              default value
 814  *
 815  * This interface function bind a thermal cooling device to the certain trip
 816  * point of a thermal zone device.
 817  * This function is usually called in the thermal zone device .bind callback.
 818  *
 819  * Return: 0 on success, the proper error value otherwise.
 820  */
 821 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 822                                      int trip,
 823                                      struct thermal_cooling_device *cdev,
 824                                      unsigned long upper, unsigned long lower,
 825                                      unsigned int weight)
 826 {
 827         struct thermal_instance *dev;
 828         struct thermal_instance *pos;
 829         struct thermal_zone_device *pos1;
 830         struct thermal_cooling_device *pos2;
 831         unsigned long max_state;
 832         int result, ret;
 833
 834         if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE))
 835                 return -EINVAL;
 836
 837         list_for_each_entry(pos1, &thermal_tz_list, node) {
 838                 if (pos1 == tz)
 839                         break;
 840         }
 841         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 842                 if (pos2 == cdev)
 843                         break;
 844         }
 845
 846         if (tz != pos1 || cdev != pos2)
 847                 return -EINVAL;
 848
 849         ret = cdev->ops->get_max_state(cdev, &max_state);
 850         if (ret)
 851                 return ret;
 852
 853         /* lower default 0, upper default max_state */
 854         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 855         upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
 856
 857         if (lower > upper || upper > max_state)
 858                 return -EINVAL;
 859
 860         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 861         if (!dev)
 862                 return -ENOMEM;
 863         dev->tz = tz;
 864         dev->cdev = cdev;
 865         dev->trip = trip;
 866         dev->upper = upper;
 867         dev->lower = lower;
 868         dev->target = THERMAL_NO_TARGET;
 869         dev->weight = weight;
 870
 871         result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
 872         if (result < 0)
 873                 goto free_mem;
 874
 875         dev->id = result;
 876         sprintf(dev->name, "cdev%d", dev->id);
 877         result =
 878             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 879         if (result)
 880                 goto release_ida;
 881
 882         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 883         sysfs_attr_init(&dev->attr.attr);
 884         dev->attr.attr.name = dev->attr_name;
 885         dev->attr.attr.mode = 0444;
 886         dev->attr.show = trip_point_show;
 887         result = device_create_file(&tz->device, &dev->attr);
 888         if (result)
 889                 goto remove_symbol_link;
 890
 891         sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
 892         sysfs_attr_init(&dev->weight_attr.attr);
 893         dev->weight_attr.attr.name = dev->weight_attr_name;
 894         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 895         dev->weight_attr.show = weight_show;
 896         dev->weight_attr.store = weight_store;
 897         result = device_create_file(&tz->device, &dev->weight_attr);
 898         if (result)
 899                 goto remove_trip_file;
 900
 901         mutex_lock(&tz->lock);
 902         mutex_lock(&cdev->lock);
 903         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 904                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 905                         result = -EEXIST;
 906                         break;
 907                 }
 908         if (!result) {
 909                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 910                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 911                 atomic_set(&tz->need_update, 1);
 912         }
 913         mutex_unlock(&cdev->lock);
 914         mutex_unlock(&tz->lock);
 915
 916         if (!result)
 917                 return 0;
 918
 919         device_remove_file(&tz->device, &dev->weight_attr);
 920 remove_trip_file:
 921         device_remove_file(&tz->device, &dev->attr);
 922 remove_symbol_link:
 923         sysfs_remove_link(&tz->device.kobj, dev->name);
 924 release_ida:
 925         ida_simple_remove(&tz->ida, dev->id);
 926 free_mem:
 927         kfree(dev);
 928         return result;
 929 }
 930 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 931
 932 /**
 933  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 934  *                                        thermal zone.
 935  * @tz:         pointer to a struct thermal_zone_device.
 936  * @trip:       indicates which trip point the cooling devices is
 937  *              associated with in this thermal zone.
 938  * @cdev:       pointer to a struct thermal_cooling_device.
 939  *
 940  * This interface function unbind a thermal cooling device from the certain
 941  * trip point of a thermal zone device.
 942  * This function is usually called in the thermal zone device .unbind callback.
 943  *
 944  * Return: 0 on success, the proper error value otherwise.
 945  */
 946 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 947                                        int trip,
 948                                        struct thermal_cooling_device *cdev)
 949 {
 950         struct thermal_instance *pos, *next;
 951
 952         mutex_lock(&tz->lock);
 953         mutex_lock(&cdev->lock);
 954         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 955                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 956                         list_del(&pos->tz_node);
 957                         list_del(&pos->cdev_node);
 958                         mutex_unlock(&cdev->lock);
 959                         mutex_unlock(&tz->lock);
 960                         goto unbind;
 961                 }
 962         }
 963         mutex_unlock(&cdev->lock);
 964         mutex_unlock(&tz->lock);
 965
 966         return -ENODEV;
 967
 968 unbind:
 969         device_remove_file(&tz->device, &pos->weight_attr);
 970         device_remove_file(&tz->device, &pos->attr);
 971         sysfs_remove_link(&tz->device.kobj, pos->name);
 972         ida_simple_remove(&tz->ida, pos->id);
 973         kfree(pos);
 974         return 0;
 975 }
 976 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 977
 978 static void thermal_release(struct device *dev)
 979 {
 980         struct thermal_zone_device *tz;
 981         struct thermal_cooling_device *cdev;
 982
 983         if (!strncmp(dev_name(dev), "thermal_zone",
 984                      sizeof("thermal_zone") - 1)) {
 985                 tz = to_thermal_zone(dev);
 986                 thermal_zone_destroy_device_groups(tz);
 987                 kfree(tz);
 988         } else if (!strncmp(dev_name(dev), "cooling_device",
 989                             sizeof("cooling_device") - 1)) {
 990                 cdev = to_cooling_device(dev);
 991                 kfree(cdev);
 992         }
 993 }
 994
 995 static struct class thermal_class = {
 996         .name = "thermal",
 997         .dev_release = thermal_release,
 998 };
 999
1000 static inline
1001 void print_bind_err_msg(struct thermal_zone_device *tz,
1002                         struct thermal_cooling_device *cdev, int ret)
1003 {
1004         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
1005                 tz->type, cdev->type, ret);
1006 }
1007
1008 static void __bind(struct thermal_zone_device *tz, int mask,
1009                    struct thermal_cooling_device *cdev,
1010                    unsigned long *limits,
1011                    unsigned int weight)
1012 {
1013         int i, ret;
1014
1015         for (i = 0; i < tz->trips; i++) {
1016                 if (mask & (1 << i)) {
1017                         unsigned long upper, lower;
1018
1019                         upper = THERMAL_NO_LIMIT;
1020                         lower = THERMAL_NO_LIMIT;
1021                         if (limits) {
1022                                 lower = limits[i * 2];
1023                                 upper = limits[i * 2 + 1];
1024                         }
1025                         ret = thermal_zone_bind_cooling_device(tz, i, cdev,
1026                                                                upper, lower,
1027                                                                weight);
1028                         if (ret)
1029                                 print_bind_err_msg(tz, cdev, ret);
1030                 }
1031         }
1032 }
1033
1034 static void bind_cdev(struct thermal_cooling_device *cdev)
1035 {
1036         int i, ret;
1037         const struct thermal_zone_params *tzp;
1038         struct thermal_zone_device *pos = NULL;
1039
1040         mutex_lock(&thermal_list_lock);
1041
1042         list_for_each_entry(pos, &thermal_tz_list, node) {
1043                 if (!pos->tzp && !pos->ops->bind)
1044                         continue;
1045
1046                 if (pos->ops->bind) {
1047                         ret = pos->ops->bind(pos, cdev);
1048                         if (ret)
1049                                 print_bind_err_msg(pos, cdev, ret);
1050                         continue;
1051                 }
1052
1053                 tzp = pos->tzp;
1054                 if (!tzp || !tzp->tbp)
1055                         continue;
1056
1057                 for (i = 0; i < tzp->num_tbps; i++) {
1058                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1059                                 continue;
1060                         if (tzp->tbp[i].match(pos, cdev))
1061                                 continue;
1062                         tzp->tbp[i].cdev = cdev;
1063                         __bind(pos, tzp->tbp[i].trip_mask, cdev,
1064                                tzp->tbp[i].binding_limits,
1065                                tzp->tbp[i].weight);
1066                 }
1067         }
1068
1069         mutex_unlock(&thermal_list_lock);
1070 }
1071
1072 /**
1073  * __thermal_cooling_device_register() - register a new thermal cooling device
1074  * @np:         a pointer to a device tree node.
1075  * @type:       the thermal cooling device type.
1076  * @devdata:    device private data.
1077  * @ops:                standard thermal cooling devices callbacks.
1078  *
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  * It also gives the opportunity to link the cooling device to a device tree
1083  * node, so that it can be bound to a thermal zone created out of device tree.
1084  *
1085  * Return: a pointer to the created struct thermal_cooling_device or an
1086  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1087  */
1088 static struct thermal_cooling_device *
1089 __thermal_cooling_device_register(struct device_node *np,
1090                                   const char *type, void *devdata,
1091                                   const struct thermal_cooling_device_ops *ops)
1092 {
1093         struct thermal_cooling_device *cdev;
1094         struct thermal_zone_device *pos = NULL;
1095         int id, ret;
1096
1097         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
1098             !ops->set_cur_state)
1099                 return ERR_PTR(-EINVAL);
1100
1101         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
1102         if (!cdev)
1103                 return ERR_PTR(-ENOMEM);
1104
1105         ret = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
1106         if (ret < 0)
1107                 goto out_kfree_cdev;
1108         cdev->id = ret;
1109         id = ret;
1110
1111         cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
1112         if (!cdev->type) {
1113                 ret = -ENOMEM;
1114                 goto out_ida_remove;
1115         }
1116
1117         mutex_init(&cdev->lock);
1118         INIT_LIST_HEAD(&cdev->thermal_instances);
1119         cdev->np = np;
1120         cdev->ops = ops;
1121         cdev->updated = false;
1122         cdev->device.class = &thermal_class;
1123         cdev->devdata = devdata;
1124         thermal_cooling_device_setup_sysfs(cdev);
1125         dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
1126         ret = device_register(&cdev->device);
1127         if (ret)
1128                 goto out_kfree_type;
1129
1130         /* Add 'this' new cdev to the global cdev list */
1131         mutex_lock(&thermal_list_lock);
1132         list_add(&cdev->node, &thermal_cdev_list);
1133         mutex_unlock(&thermal_list_lock);
1134
1135         /* Update binding information for 'this' new cdev */
1136         bind_cdev(cdev);
1137
1138         mutex_lock(&thermal_list_lock);
1139         list_for_each_entry(pos, &thermal_tz_list, node)
1140                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
1141                         thermal_zone_device_update(pos,
1142                                                    THERMAL_EVENT_UNSPECIFIED);
1143         mutex_unlock(&thermal_list_lock);
1144
1145         return cdev;
1146
1147 out_kfree_type:
1148         thermal_cooling_device_destroy_sysfs(cdev);
1149         kfree(cdev->type);
1150         put_device(&cdev->device);
1151         cdev = NULL;
1152 out_ida_remove:
1153         ida_simple_remove(&thermal_cdev_ida, id);
1154 out_kfree_cdev:
1155         kfree(cdev);
1156         return ERR_PTR(ret);
1157 }
1158
1159 /**
1160  * thermal_cooling_device_register() - register a new thermal cooling device
1161  * @type:       the thermal cooling device type.
1162  * @devdata:    device private data.
1163  * @ops:                standard thermal cooling devices callbacks.
1164  *
1165  * This interface function adds a new thermal cooling device (fan/processor/...)
1166  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1167  * to all the thermal zone devices registered at the same time.
1168  *
1169  * Return: a pointer to the created struct thermal_cooling_device or an
1170  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1171  */
1172 struct thermal_cooling_device *
1173 thermal_cooling_device_register(const char *type, void *devdata,
1174                                 const struct thermal_cooling_device_ops *ops)
1175 {
1176         return __thermal_cooling_device_register(NULL, type, devdata, ops);
1177 }
1178 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1179
1180 /**
1181  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1182  * @np:         a pointer to a device tree node.
1183  * @type:       the thermal cooling device type.
1184  * @devdata:    device private data.
1185  * @ops:                standard thermal cooling devices callbacks.
1186  *
1187  * This function will register a cooling device with device tree node reference.
1188  * This interface function adds a new thermal cooling device (fan/processor/...)
1189  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1190  * to all the thermal zone devices registered at the same time.
1191  *
1192  * Return: a pointer to the created struct thermal_cooling_device or an
1193  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1194  */
1195 struct thermal_cooling_device *
1196 thermal_of_cooling_device_register(struct device_node *np,
1197                                    const char *type, void *devdata,
1198                                    const struct thermal_cooling_device_ops *ops)
1199 {
1200         return __thermal_cooling_device_register(np, type, devdata, ops);
1201 }
1202 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1203
1204 static void thermal_cooling_device_release(struct device *dev, void *res)
1205 {
1206         thermal_cooling_device_unregister(
1207                                 *(struct thermal_cooling_device **)res);
1208 }
1209
1210 /**
1211  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1212  *                                             device
1213  * @dev:        a valid struct device pointer of a sensor device.
1214  * @np:         a pointer to a device tree node.
1215  * @type:       the thermal cooling device type.
1216  * @devdata:    device private data.
1217  * @ops:        standard thermal cooling devices callbacks.
1218  *
1219  * This function will register a cooling device with device tree node reference.
1220  * This interface function adds a new thermal cooling device (fan/processor/...)
1221  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1222  * to all the thermal zone devices registered at the same time.
1223  *
1224  * Return: a pointer to the created struct thermal_cooling_device or an
1225  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1226  */
1227 struct thermal_cooling_device *
1228 devm_thermal_of_cooling_device_register(struct device *dev,
1229                                 struct device_node *np,
1230                                 char *type, void *devdata,
1231                                 const struct thermal_cooling_device_ops *ops)
1232 {
1233         struct thermal_cooling_device **ptr, *tcd;
1234
1235         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1236                            GFP_KERNEL);
1237         if (!ptr)
1238                 return ERR_PTR(-ENOMEM);
1239
1240         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1241         if (IS_ERR(tcd)) {
1242                 devres_free(ptr);
1243                 return tcd;
1244         }
1245
1246         *ptr = tcd;
1247         devres_add(dev, ptr);
1248
1249         return tcd;
1250 }
1251 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1252
1253 static void __unbind(struct thermal_zone_device *tz, int mask,
1254                      struct thermal_cooling_device *cdev)
1255 {
1256         int i;
1257
1258         for (i = 0; i < tz->trips; i++)
1259                 if (mask & (1 << i))
1260                         thermal_zone_unbind_cooling_device(tz, i, cdev);
1261 }
1262
1263 /**
1264  * thermal_cooling_device_unregister - removes a thermal cooling device
1265  * @cdev:       the thermal cooling device to remove.
1266  *
1267  * thermal_cooling_device_unregister() must be called when a registered
1268  * thermal cooling device is no longer needed.
1269  */
1270 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1271 {
1272         int i;
1273         const struct thermal_zone_params *tzp;
1274         struct thermal_zone_device *tz;
1275         struct thermal_cooling_device *pos = NULL;
1276
1277         if (!cdev)
1278                 return;
1279
1280         mutex_lock(&thermal_list_lock);
1281         list_for_each_entry(pos, &thermal_cdev_list, node)
1282                 if (pos == cdev)
1283                         break;
1284         if (pos != cdev) {
1285                 /* thermal cooling device not found */
1286                 mutex_unlock(&thermal_list_lock);
1287                 return;
1288         }
1289         list_del(&cdev->node);
1290
1291         /* Unbind all thermal zones associated with 'this' cdev */
1292         list_for_each_entry(tz, &thermal_tz_list, node) {
1293                 if (tz->ops->unbind) {
1294                         tz->ops->unbind(tz, cdev);
1295                         continue;
1296                 }
1297
1298                 if (!tz->tzp || !tz->tzp->tbp)
1299                         continue;
1300
1301                 tzp = tz->tzp;
1302                 for (i = 0; i < tzp->num_tbps; i++) {
1303                         if (tzp->tbp[i].cdev == cdev) {
1304                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1305                                 tzp->tbp[i].cdev = NULL;
1306                         }
1307                 }
1308         }
1309
1310         mutex_unlock(&thermal_list_lock);
1311
1312         ida_simple_remove(&thermal_cdev_ida, cdev->id);
1313         device_del(&cdev->device);
1314         thermal_cooling_device_destroy_sysfs(cdev);
1315         kfree(cdev->type);
1316         put_device(&cdev->device);
1317 }
1318 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1319
1320 static void bind_tz(struct thermal_zone_device *tz)
1321 {
1322         int i, ret;
1323         struct thermal_cooling_device *pos = NULL;
1324         const struct thermal_zone_params *tzp = tz->tzp;
1325
1326         if (!tzp && !tz->ops->bind)
1327                 return;
1328
1329         mutex_lock(&thermal_list_lock);
1330
1331         /* If there is ops->bind, try to use ops->bind */
1332         if (tz->ops->bind) {
1333                 list_for_each_entry(pos, &thermal_cdev_list, node) {
1334                         ret = tz->ops->bind(tz, pos);
1335                         if (ret)
1336                                 print_bind_err_msg(tz, pos, ret);
1337                 }
1338                 goto exit;
1339         }
1340
1341         if (!tzp || !tzp->tbp)
1342                 goto exit;
1343
1344         list_for_each_entry(pos, &thermal_cdev_list, node) {
1345                 for (i = 0; i < tzp->num_tbps; i++) {
1346                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1347                                 continue;
1348                         if (tzp->tbp[i].match(tz, pos))
1349                                 continue;
1350                         tzp->tbp[i].cdev = pos;
1351                         __bind(tz, tzp->tbp[i].trip_mask, pos,
1352                                tzp->tbp[i].binding_limits,
1353                                tzp->tbp[i].weight);
1354                 }
1355         }
1356 exit:
1357         mutex_unlock(&thermal_list_lock);
1358 }
1359
1360 /**
1361  * thermal_zone_device_register() - register a new thermal zone device
1362  * @type:       the thermal zone device type
1363  * @trips:      the number of trip points the thermal zone support
1364  * @mask:       a bit string indicating the writeablility of trip points
1365  * @devdata:    private device data
1366  * @ops:        standard thermal zone device callbacks
1367  * @tzp:        thermal zone platform parameters
1368  * @passive_delay: number of milliseconds to wait between polls when
1369  *                 performing passive cooling
1370  * @polling_delay: number of milliseconds to wait between polls when checking
1371  *                 whether trip points have been crossed (0 for interrupt
1372  *                 driven systems)
1373  *
1374  * This interface function adds a new thermal zone device (sensor) to
1375  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1376  * thermal cooling devices registered at the same time.
1377  * thermal_zone_device_unregister() must be called when the device is no
1378  * longer needed. The passive cooling depends on the .get_trend() return value.
1379  *
1380  * Return: a pointer to the created struct thermal_zone_device or an
1381  * in case of error, an ERR_PTR. Caller must check return value with
1382  * IS_ERR*() helpers.
1383  */
1384 struct thermal_zone_device *
1385 thermal_zone_device_register(const char *type, int trips, int mask,
1386                              void *devdata, struct thermal_zone_device_ops *ops,
1387                              struct thermal_zone_params *tzp, int passive_delay,
1388                              int polling_delay)
1389 {
1390         struct thermal_zone_device *tz;
1391         enum thermal_trip_type trip_type;
1392         int trip_temp;
1393         int id;
1394         int result;
1395         int count;
1396         struct thermal_governor *governor;
1397
1398         if (!type || strlen(type) == 0) {
1399                 pr_err("Error: No thermal zone type defined\n");
1400                 return ERR_PTR(-EINVAL);
1401         }
1402
1403         if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
1404                 pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
1405                        type, THERMAL_NAME_LENGTH);
1406                 return ERR_PTR(-EINVAL);
1407         }
1408
1409         if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
1410                 pr_err("Error: Incorrect number of thermal trips\n");
1411                 return ERR_PTR(-EINVAL);
1412         }
1413
1414         if (!ops) {
1415                 pr_err("Error: Thermal zone device ops not defined\n");
1416                 return ERR_PTR(-EINVAL);
1417         }
1418
1419         if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1420                 return ERR_PTR(-EINVAL);
1421
1422         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1423         if (!tz)
1424                 return ERR_PTR(-ENOMEM);
1425
1426         INIT_LIST_HEAD(&tz->thermal_instances);
1427         ida_init(&tz->ida);
1428         mutex_init(&tz->lock);
1429         id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1430         if (id < 0) {
1431                 result = id;
1432                 goto free_tz;
1433         }
1434
1435         tz->id = id;
1436         strlcpy(tz->type, type, sizeof(tz->type));
1437         tz->ops = ops;
1438         tz->tzp = tzp;
1439         tz->device.class = &thermal_class;
1440         tz->devdata = devdata;
1441         tz->trips = trips;
1442         tz->passive_delay = passive_delay;
1443         tz->polling_delay = polling_delay;
1444
1445         /* sys I/F */
1446         /* Add nodes that are always present via .groups */
1447         result = thermal_zone_create_device_groups(tz, mask);
1448         if (result)
1449                 goto remove_id;
1450
1451         /* A new thermal zone needs to be updated anyway. */
1452         atomic_set(&tz->need_update, 1);
1453
1454         dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1455         result = device_register(&tz->device);
1456         if (result)
1457                 goto release_device;
1458
1459         for (count = 0; count < trips; count++) {
1460                 if (tz->ops->get_trip_type(tz, count, &trip_type))
1461                         set_bit(count, &tz->trips_disabled);
1462                 if (tz->ops->get_trip_temp(tz, count, &trip_temp))
1463                         set_bit(count, &tz->trips_disabled);
1464                 /* Check for bogus trip points */
1465                 if (trip_temp == 0)
1466                         set_bit(count, &tz->trips_disabled);
1467         }
1468
1469         /* Update 'this' zone's governor information */
1470         mutex_lock(&thermal_governor_lock);
1471
1472         if (tz->tzp)
1473                 governor = __find_governor(tz->tzp->governor_name);
1474         else
1475                 governor = def_governor;
1476
1477         result = thermal_set_governor(tz, governor);
1478         if (result) {
1479                 mutex_unlock(&thermal_governor_lock);
1480                 goto unregister;
1481         }
1482
1483         mutex_unlock(&thermal_governor_lock);
1484
1485         if (!tz->tzp || !tz->tzp->no_hwmon) {
1486                 result = thermal_add_hwmon_sysfs(tz);
1487                 if (result)
1488                         goto unregister;
1489         }
1490
1491         mutex_lock(&thermal_list_lock);
1492         list_add_tail(&tz->node, &thermal_tz_list);
1493         mutex_unlock(&thermal_list_lock);
1494
1495         /* Bind cooling devices for this zone */
1496         bind_tz(tz);
1497
1498         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1499
1500         thermal_zone_device_reset(tz);
1501         /* Update the new thermal zone and mark it as already updated. */
1502         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1503                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1504
1505         thermal_notify_tz_create(tz->id, tz->type);
1506
1507         return tz;
1508
1509 unregister:
1510         device_del(&tz->device);
1511 release_device:
1512         put_device(&tz->device);
1513         tz = NULL;
1514 remove_id:
1515         ida_simple_remove(&thermal_tz_ida, id);
1516 free_tz:
1517         kfree(tz);
1518         return ERR_PTR(result);
1519 }
1520 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1521
1522 /**
1523  * thermal_zone_device_unregister - removes the registered thermal zone device
1524  * @tz: the thermal zone device to remove
1525  */
1526 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1527 {
1528         int i, tz_id;
1529         const struct thermal_zone_params *tzp;
1530         struct thermal_cooling_device *cdev;
1531         struct thermal_zone_device *pos = NULL;
1532
1533         if (!tz)
1534                 return;
1535
1536         tzp = tz->tzp;
1537         tz_id = tz->id;
1538
1539         mutex_lock(&thermal_list_lock);
1540         list_for_each_entry(pos, &thermal_tz_list, node)
1541                 if (pos == tz)
1542                         break;
1543         if (pos != tz) {
1544                 /* thermal zone device not found */
1545                 mutex_unlock(&thermal_list_lock);
1546                 return;
1547         }
1548         list_del(&tz->node);
1549
1550         /* Unbind all cdevs associated with 'this' thermal zone */
1551         list_for_each_entry(cdev, &thermal_cdev_list, node) {
1552                 if (tz->ops->unbind) {
1553                         tz->ops->unbind(tz, cdev);
1554                         continue;
1555                 }
1556
1557                 if (!tzp || !tzp->tbp)
1558                         break;
1559
1560                 for (i = 0; i < tzp->num_tbps; i++) {
1561                         if (tzp->tbp[i].cdev == cdev) {
1562                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1563                                 tzp->tbp[i].cdev = NULL;
1564                         }
1565                 }
1566         }
1567
1568         mutex_unlock(&thermal_list_lock);
1569
1570         cancel_delayed_work_sync(&tz->poll_queue);
1571
1572         thermal_set_governor(tz, NULL);
1573
1574         thermal_remove_hwmon_sysfs(tz);
1575         ida_simple_remove(&thermal_tz_ida, tz->id);
1576         ida_destroy(&tz->ida);
1577         mutex_destroy(&tz->lock);
1578         device_unregister(&tz->device);
1579
1580         thermal_notify_tz_delete(tz_id);
1581 }
1582 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1583
1584 /**
1585  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1586  * @name: thermal zone name to fetch the temperature
1587  *
1588  * When only one zone is found with the passed name, returns a reference to it.
1589  *
1590  * Return: On success returns a reference to an unique thermal zone with
1591  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1592  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1593  */
1594 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1595 {
1596         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1597         unsigned int found = 0;
1598
1599         if (!name)
1600                 goto exit;
1601
1602         mutex_lock(&thermal_list_lock);
1603         list_for_each_entry(pos, &thermal_tz_list, node)
1604                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1605                         found++;
1606                         ref = pos;
1607                 }
1608         mutex_unlock(&thermal_list_lock);
1609
1610         /* nothing has been found, thus an error code for it */
1611         if (found == 0)
1612                 ref = ERR_PTR(-ENODEV);
1613         else if (found > 1)
1614         /* Success only when an unique zone is found */
1615                 ref = ERR_PTR(-EEXIST);
1616
1617 exit:
1618         return ref;
1619 }
1620 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1621
1622 static int thermal_pm_notify(struct notifier_block *nb,
1623                              unsigned long mode, void *_unused)
1624 {
1625         struct thermal_zone_device *tz;
1626
1627         switch (mode) {
1628         case PM_HIBERNATION_PREPARE:
1629         case PM_RESTORE_PREPARE:
1630         case PM_SUSPEND_PREPARE:
1631                 atomic_set(&in_suspend, 1);
1632                 break;
1633         case PM_POST_HIBERNATION:
1634         case PM_POST_RESTORE:
1635         case PM_POST_SUSPEND:
1636                 atomic_set(&in_suspend, 0);
1637                 list_for_each_entry(tz, &thermal_tz_list, node) {
1638                         if (!thermal_zone_device_is_enabled(tz))
1639                                 continue;
1640
1641                         thermal_zone_device_init(tz);
1642                         thermal_zone_device_update(tz,
1643                                                    THERMAL_EVENT_UNSPECIFIED);
1644                 }
1645                 break;
1646         default:
1647                 break;
1648         }
1649         return 0;
1650 }
1651
1652 static struct notifier_block thermal_pm_nb = {
1653         .notifier_call = thermal_pm_notify,
1654 };
1655
1656 static int __init thermal_init(void)
1657 {
1658         int result;
1659
1660         result = thermal_netlink_init();
1661         if (result)
1662                 goto error;
1663
1664         result = thermal_register_governors();
1665         if (result)
1666                 goto error;
1667
1668         result = class_register(&thermal_class);
1669         if (result)
1670                 goto unregister_governors;
1671
1672         result = of_parse_thermal_zones();
1673         if (result)
1674                 goto unregister_class;
1675
1676         result = register_pm_notifier(&thermal_pm_nb);
1677         if (result)
1678                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1679                         result);
1680
1681         return 0;
1682
1683 unregister_class:
1684         class_unregister(&thermal_class);
1685 unregister_governors:
1686         thermal_unregister_governors();
1687 error:
1688         ida_destroy(&thermal_tz_ida);
1689         ida_destroy(&thermal_cdev_ida);
1690         mutex_destroy(&thermal_list_lock);
1691         mutex_destroy(&thermal_governor_lock);
1692         mutex_destroy(&poweroff_lock);
1693         return result;
1694 }
1695 postcore_initcall(thermal_init);