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                                             int delay)
 293 {
 294         if (delay > 1000)
 295                 mod_delayed_work(system_freezable_power_efficient_wq,
 296                                  &tz->poll_queue,
 297                                  round_jiffies(msecs_to_jiffies(delay)));
 298         else if (delay)
 299                 mod_delayed_work(system_freezable_power_efficient_wq,
 300                                  &tz->poll_queue,
 301                                  msecs_to_jiffies(delay));
 302         else
 303                 cancel_delayed_work(&tz->poll_queue);
 304 }
 305
 306 static inline bool should_stop_polling(struct thermal_zone_device *tz)
 307 {
 308         return !thermal_zone_device_is_enabled(tz);
 309 }
 310
 311 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 312 {
 313         bool stop;
 314
 315         stop = should_stop_polling(tz);
 316
 317         mutex_lock(&tz->lock);
 318
 319         if (!stop && tz->passive)
 320                 thermal_zone_device_set_polling(tz, tz->passive_delay);
 321         else if (!stop && tz->polling_delay)
 322                 thermal_zone_device_set_polling(tz, tz->polling_delay);
 323         else
 324                 thermal_zone_device_set_polling(tz, 0);
 325
 326         mutex_unlock(&tz->lock);
 327 }
 328
 329 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 330 {
 331         tz->governor ? tz->governor->throttle(tz, trip) :
 332                        def_governor->throttle(tz, trip);
 333 }
 334
 335 /**
 336  * thermal_emergency_poweroff_func - emergency poweroff work after a known delay
 337  * @work: work_struct associated with the emergency poweroff function
 338  *
 339  * This function is called in very critical situations to force
 340  * a kernel poweroff after a configurable timeout value.
 341  */
 342 static void thermal_emergency_poweroff_func(struct work_struct *work)
 343 {
 344         /*
 345          * We have reached here after the emergency thermal shutdown
 346          * Waiting period has expired. This means orderly_poweroff has
 347          * not been able to shut off the system for some reason.
 348          * Try to shut down the system immediately using kernel_power_off
 349          * if populated
 350          */
 351         WARN(1, "Attempting kernel_power_off: Temperature too high\n");
 352         kernel_power_off();
 353
 354         /*
 355          * Worst of the worst case trigger emergency restart
 356          */
 357         WARN(1, "Attempting emergency_restart: Temperature too high\n");
 358         emergency_restart();
 359 }
 360
 361 static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work,
 362                             thermal_emergency_poweroff_func);
 363
 364 /**
 365  * thermal_emergency_poweroff - Trigger an emergency system poweroff
 366  *
 367  * This may be called from any critical situation to trigger a system shutdown
 368  * after a known period of time. By default this is not scheduled.
 369  */
 370 static void thermal_emergency_poweroff(void)
 371 {
 372         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 373         /*
 374          * poweroff_delay_ms must be a carefully profiled positive value.
 375          * Its a must for thermal_emergency_poweroff_work to be scheduled
 376          */
 377         if (poweroff_delay_ms <= 0)
 378                 return;
 379         schedule_delayed_work(&thermal_emergency_poweroff_work,
 380                               msecs_to_jiffies(poweroff_delay_ms));
 381 }
 382
 383 static void handle_critical_trips(struct thermal_zone_device *tz,
 384                                   int trip, enum thermal_trip_type trip_type)
 385 {
 386         int trip_temp;
 387
 388         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 389
 390         /* If we have not crossed the trip_temp, we do not care. */
 391         if (trip_temp <= 0 || tz->temperature < trip_temp)
 392                 return;
 393
 394         trace_thermal_zone_trip(tz, trip, trip_type);
 395
 396         if (tz->ops->notify)
 397                 tz->ops->notify(tz, trip, trip_type);
 398
 399         if (trip_type == THERMAL_TRIP_CRITICAL) {
 400                 dev_emerg(&tz->device,
 401                           "critical temperature reached (%d C), shutting down\n",
 402                           tz->temperature / 1000);
 403                 mutex_lock(&poweroff_lock);
 404                 if (!power_off_triggered) {
 405                         /*
 406                          * Queue a backup emergency shutdown in the event of
 407                          * orderly_poweroff failure
 408                          */
 409                         thermal_emergency_poweroff();
 410                         orderly_poweroff(true);
 411                         power_off_triggered = true;
 412                 }
 413                 mutex_unlock(&poweroff_lock);
 414         }
 415 }
 416
 417 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip)
 418 {
 419         enum thermal_trip_type type;
 420         int trip_temp, hyst = 0;
 421
 422         /* Ignore disabled trip points */
 423         if (test_bit(trip, &tz->trips_disabled))
 424                 return;
 425
 426         tz->ops->get_trip_temp(tz, trip, &trip_temp);
 427         tz->ops->get_trip_type(tz, trip, &type);
 428         if (tz->ops->get_trip_hyst)
 429                 tz->ops->get_trip_hyst(tz, trip, &hyst);
 430
 431         if (tz->last_temperature != THERMAL_TEMP_INVALID) {
 432                 if (tz->last_temperature < trip_temp &&
 433                     tz->temperature >= trip_temp)
 434                         thermal_notify_tz_trip_up(tz->id, trip);
 435                 if (tz->last_temperature >= trip_temp &&
 436                     tz->temperature < (trip_temp - hyst))
 437                         thermal_notify_tz_trip_down(tz->id, trip);
 438         }
 439
 440         if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT)
 441                 handle_critical_trips(tz, trip, type);
 442         else
 443                 handle_non_critical_trips(tz, trip);
 444         /*
 445          * Alright, we handled this trip successfully.
 446          * So, start monitoring again.
 447          */
 448         monitor_thermal_zone(tz);
 449 }
 450
 451 static void update_temperature(struct thermal_zone_device *tz)
 452 {
 453         int temp, ret;
 454
 455         ret = thermal_zone_get_temp(tz, &temp);
 456         if (ret) {
 457                 if (ret != -EAGAIN)
 458                         dev_warn(&tz->device,
 459                                  "failed to read out thermal zone (%d)\n",
 460                                  ret);
 461                 return;
 462         }
 463
 464         mutex_lock(&tz->lock);
 465         tz->last_temperature = tz->temperature;
 466         tz->temperature = temp;
 467         mutex_unlock(&tz->lock);
 468
 469         trace_thermal_temperature(tz);
 470
 471         thermal_genl_sampling_temp(tz->id, temp);
 472 }
 473
 474 static void thermal_zone_device_init(struct thermal_zone_device *tz)
 475 {
 476         struct thermal_instance *pos;
 477         tz->temperature = THERMAL_TEMP_INVALID;
 478         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 479                 pos->initialized = false;
 480 }
 481
 482 static void thermal_zone_device_reset(struct thermal_zone_device *tz)
 483 {
 484         tz->passive = 0;
 485         thermal_zone_device_init(tz);
 486 }
 487
 488 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 489                                         enum thermal_device_mode mode)
 490 {
 491         int ret = 0;
 492
 493         mutex_lock(&tz->lock);
 494
 495         /* do nothing if mode isn't changing */
 496         if (mode == tz->mode) {
 497                 mutex_unlock(&tz->lock);
 498
 499                 return ret;
 500         }
 501
 502         if (tz->ops->change_mode)
 503                 ret = tz->ops->change_mode(tz, mode);
 504
 505         if (!ret)
 506                 tz->mode = mode;
 507
 508         mutex_unlock(&tz->lock);
 509
 510         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 511
 512         if (mode == THERMAL_DEVICE_ENABLED)
 513                 thermal_notify_tz_enable(tz->id);
 514         else
 515                 thermal_notify_tz_disable(tz->id);
 516
 517         return ret;
 518 }
 519
 520 int thermal_zone_device_enable(struct thermal_zone_device *tz)
 521 {
 522         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
 523 }
 524 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
 525
 526 int thermal_zone_device_disable(struct thermal_zone_device *tz)
 527 {
 528         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 529 }
 530 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 531
 532 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
 533 {
 534         enum thermal_device_mode mode;
 535
 536         mutex_lock(&tz->lock);
 537
 538         mode = tz->mode;
 539
 540         mutex_unlock(&tz->lock);
 541
 542         return mode == THERMAL_DEVICE_ENABLED;
 543 }
 544
 545 void thermal_zone_device_update(struct thermal_zone_device *tz,
 546                                 enum thermal_notify_event event)
 547 {
 548         int count;
 549
 550         if (should_stop_polling(tz))
 551                 return;
 552
 553         if (atomic_read(&in_suspend))
 554                 return;
 555
 556         if (!tz->ops->get_temp)
 557                 return;
 558
 559         update_temperature(tz);
 560
 561         thermal_zone_set_trips(tz);
 562
 563         tz->notify_event = event;
 564
 565         for (count = 0; count < tz->trips; count++)
 566                 handle_thermal_trip(tz, count);
 567 }
 568 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 569
 570 /**
 571  * thermal_notify_framework - Sensor drivers use this API to notify framework
 572  * @tz:         thermal zone device
 573  * @trip:       indicates which trip point has been crossed
 574  *
 575  * This function handles the trip events from sensor drivers. It starts
 576  * throttling the cooling devices according to the policy configured.
 577  * For CRITICAL and HOT trip points, this notifies the respective drivers,
 578  * and does actual throttling for other trip points i.e ACTIVE and PASSIVE.
 579  * The throttling policy is based on the configured platform data; if no
 580  * platform data is provided, this uses the step_wise throttling policy.
 581  */
 582 void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
 583 {
 584         handle_thermal_trip(tz, trip);
 585 }
 586 EXPORT_SYMBOL_GPL(thermal_notify_framework);
 587
 588 static void thermal_zone_device_check(struct work_struct *work)
 589 {
 590         struct thermal_zone_device *tz = container_of(work, struct
 591                                                       thermal_zone_device,
 592                                                       poll_queue.work);
 593         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 594 }
 595
 596 /*
 597  * Power actor section: interface to power actors to estimate power
 598  *
 599  * Set of functions used to interact to cooling devices that know
 600  * how to estimate their devices power consumption.
 601  */
 602
 603 /**
 604  * power_actor_get_max_power() - get the maximum power that a cdev can consume
 605  * @cdev:       pointer to &thermal_cooling_device
 606  * @tz:         a valid thermal zone device pointer
 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                               struct thermal_zone_device *tz, u32 *max_power)
 617 {
 618         if (!cdev_is_power_actor(cdev))
 619                 return -EINVAL;
 620
 621         return cdev->ops->state2power(cdev, tz, 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  * @tz:         a valid thermal zone device pointer
 628  * @min_power:  pointer in which to store the minimum power
 629  *
 630  * Calculate the minimum power consumption in milliwatts that the
 631  * cooling device can currently consume and store it in @min_power.
 632  *
 633  * Return: 0 on success, -EINVAL if @cdev doesn't support the
 634  * power_actor API or -E* on other error.
 635  */
 636 int power_actor_get_min_power(struct thermal_cooling_device *cdev,
 637                               struct thermal_zone_device *tz, u32 *min_power)
 638 {
 639         unsigned long max_state;
 640         int ret;
 641
 642         if (!cdev_is_power_actor(cdev))
 643                 return -EINVAL;
 644
 645         ret = cdev->ops->get_max_state(cdev, &max_state);
 646         if (ret)
 647                 return ret;
 648
 649         return cdev->ops->state2power(cdev, tz, max_state, min_power);
 650 }
 651
 652 /**
 653  * power_actor_set_power() - limit the maximum power a cooling device consumes
 654  * @cdev:       pointer to &thermal_cooling_device
 655  * @instance:   thermal instance to update
 656  * @power:      the power in milliwatts
 657  *
 658  * Set the cooling device to consume at most @power milliwatts. The limit is
 659  * expected to be a cap at the maximum power consumption.
 660  *
 661  * Return: 0 on success, -EINVAL if the cooling device does not
 662  * implement the power actor API or -E* for other failures.
 663  */
 664 int power_actor_set_power(struct thermal_cooling_device *cdev,
 665                           struct thermal_instance *instance, u32 power)
 666 {
 667         unsigned long state;
 668         int ret;
 669
 670         if (!cdev_is_power_actor(cdev))
 671                 return -EINVAL;
 672
 673         ret = cdev->ops->power2state(cdev, instance->tz, power, &state);
 674         if (ret)
 675                 return ret;
 676
 677         instance->target = state;
 678         mutex_lock(&cdev->lock);
 679         cdev->updated = false;
 680         mutex_unlock(&cdev->lock);
 681         thermal_cdev_update(cdev);
 682
 683         return 0;
 684 }
 685
 686 void thermal_zone_device_rebind_exception(struct thermal_zone_device *tz,
 687                                           const char *cdev_type, size_t size)
 688 {
 689         struct thermal_cooling_device *cdev = NULL;
 690
 691         mutex_lock(&thermal_list_lock);
 692         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 693                 /* skip non matching cdevs */
 694                 if (strncmp(cdev_type, cdev->type, size))
 695                         continue;
 696
 697                 /* re binding the exception matching the type pattern */
 698                 thermal_zone_bind_cooling_device(tz, THERMAL_TRIPS_NONE, cdev,
 699                                                  THERMAL_NO_LIMIT,
 700                                                  THERMAL_NO_LIMIT,
 701                                                  THERMAL_WEIGHT_DEFAULT);
 702         }
 703         mutex_unlock(&thermal_list_lock);
 704 }
 705
 706 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 707                               void *data)
 708 {
 709         struct thermal_governor *gov;
 710         int ret = 0;
 711
 712         mutex_lock(&thermal_governor_lock);
 713         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 714                 ret = cb(gov, data);
 715                 if (ret)
 716                         break;
 717         }
 718         mutex_unlock(&thermal_governor_lock);
 719
 720         return ret;
 721 }
 722
 723 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 724                                               void *), void *data)
 725 {
 726         struct thermal_cooling_device *cdev;
 727         int ret = 0;
 728
 729         mutex_lock(&thermal_list_lock);
 730         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 731                 ret = cb(cdev, data);
 732                 if (ret)
 733                         break;
 734         }
 735         mutex_unlock(&thermal_list_lock);
 736
 737         return ret;
 738 }
 739
 740 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 741                           void *data)
 742 {
 743         struct thermal_zone_device *tz;
 744         int ret = 0;
 745
 746         mutex_lock(&thermal_list_lock);
 747         list_for_each_entry(tz, &thermal_tz_list, node) {
 748                 ret = cb(tz, data);
 749                 if (ret)
 750                         break;
 751         }
 752         mutex_unlock(&thermal_list_lock);
 753
 754         return ret;
 755 }
 756
 757 struct thermal_zone_device *thermal_zone_get_by_id(int id)
 758 {
 759         struct thermal_zone_device *tz, *match = NULL;
 760
 761         mutex_lock(&thermal_list_lock);
 762         list_for_each_entry(tz, &thermal_tz_list, node) {
 763                 if (tz->id == id) {
 764                         match = tz;
 765                         break;
 766                 }
 767         }
 768         mutex_unlock(&thermal_list_lock);
 769
 770         return match;
 771 }
 772
 773 void thermal_zone_device_unbind_exception(struct thermal_zone_device *tz,
 774                                           const char *cdev_type, size_t size)
 775 {
 776         struct thermal_cooling_device *cdev = NULL;
 777
 778         mutex_lock(&thermal_list_lock);
 779         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 780                 /* skip non matching cdevs */
 781                 if (strncmp(cdev_type, cdev->type, size))
 782                         continue;
 783                 /* unbinding the exception matching the type pattern */
 784                 thermal_zone_unbind_cooling_device(tz, THERMAL_TRIPS_NONE,
 785                                                    cdev);
 786         }
 787         mutex_unlock(&thermal_list_lock);
 788 }
 789
 790 /*
 791  * Device management section: cooling devices, zones devices, and binding
 792  *
 793  * Set of functions provided by the thermal core for:
 794  * - cooling devices lifecycle: registration, unregistration,
 795  *                              binding, and unbinding.
 796  * - thermal zone devices lifecycle: registration, unregistration,
 797  *                                   binding, and unbinding.
 798  */
 799
 800 /**
 801  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 802  * @tz:         pointer to struct thermal_zone_device
 803  * @trip:       indicates which trip point the cooling devices is
 804  *              associated with in this thermal zone.
 805  * @cdev:       pointer to struct thermal_cooling_device
 806  * @upper:      the Maximum cooling state for this trip point.
 807  *              THERMAL_NO_LIMIT means no upper limit,
 808  *              and the cooling device can be in max_state.
 809  * @lower:      the Minimum cooling state can be used for this trip point.
 810  *              THERMAL_NO_LIMIT means no lower limit,
 811  *              and the cooling device can be in cooling state 0.
 812  * @weight:     The weight of the cooling device to be bound to the
 813  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 814  *              default value
 815  *
 816  * This interface function bind a thermal cooling device to the certain trip
 817  * point of a thermal zone device.
 818  * This function is usually called in the thermal zone device .bind callback.
 819  *
 820  * Return: 0 on success, the proper error value otherwise.
 821  */
 822 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 823                                      int trip,
 824                                      struct thermal_cooling_device *cdev,
 825                                      unsigned long upper, unsigned long lower,
 826                                      unsigned int weight)
 827 {
 828         struct thermal_instance *dev;
 829         struct thermal_instance *pos;
 830         struct thermal_zone_device *pos1;
 831         struct thermal_cooling_device *pos2;
 832         unsigned long max_state;
 833         int result, ret;
 834
 835         if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE))
 836                 return -EINVAL;
 837
 838         list_for_each_entry(pos1, &thermal_tz_list, node) {
 839                 if (pos1 == tz)
 840                         break;
 841         }
 842         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 843                 if (pos2 == cdev)
 844                         break;
 845         }
 846
 847         if (tz != pos1 || cdev != pos2)
 848                 return -EINVAL;
 849
 850         ret = cdev->ops->get_max_state(cdev, &max_state);
 851         if (ret)
 852                 return ret;
 853
 854         /* lower default 0, upper default max_state */
 855         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 856         upper = upper == THERMAL_NO_LIMIT ? max_state : upper;
 857
 858         if (lower > upper || upper > max_state)
 859                 return -EINVAL;
 860
 861         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 862         if (!dev)
 863                 return -ENOMEM;
 864         dev->tz = tz;
 865         dev->cdev = cdev;
 866         dev->trip = trip;
 867         dev->upper = upper;
 868         dev->lower = lower;
 869         dev->target = THERMAL_NO_TARGET;
 870         dev->weight = weight;
 871
 872         result = ida_simple_get(&tz->ida, 0, 0, GFP_KERNEL);
 873         if (result < 0)
 874                 goto free_mem;
 875
 876         dev->id = result;
 877         sprintf(dev->name, "cdev%d", dev->id);
 878         result =
 879             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 880         if (result)
 881                 goto release_ida;
 882
 883         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 884         sysfs_attr_init(&dev->attr.attr);
 885         dev->attr.attr.name = dev->attr_name;
 886         dev->attr.attr.mode = 0444;
 887         dev->attr.show = trip_point_show;
 888         result = device_create_file(&tz->device, &dev->attr);
 889         if (result)
 890                 goto remove_symbol_link;
 891
 892         sprintf(dev->weight_attr_name, "cdev%d_weight", dev->id);
 893         sysfs_attr_init(&dev->weight_attr.attr);
 894         dev->weight_attr.attr.name = dev->weight_attr_name;
 895         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 896         dev->weight_attr.show = weight_show;
 897         dev->weight_attr.store = weight_store;
 898         result = device_create_file(&tz->device, &dev->weight_attr);
 899         if (result)
 900                 goto remove_trip_file;
 901
 902         mutex_lock(&tz->lock);
 903         mutex_lock(&cdev->lock);
 904         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 905                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 906                         result = -EEXIST;
 907                         break;
 908                 }
 909         if (!result) {
 910                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 911                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 912                 atomic_set(&tz->need_update, 1);
 913         }
 914         mutex_unlock(&cdev->lock);
 915         mutex_unlock(&tz->lock);
 916
 917         if (!result)
 918                 return 0;
 919
 920         device_remove_file(&tz->device, &dev->weight_attr);
 921 remove_trip_file:
 922         device_remove_file(&tz->device, &dev->attr);
 923 remove_symbol_link:
 924         sysfs_remove_link(&tz->device.kobj, dev->name);
 925 release_ida:
 926         ida_simple_remove(&tz->ida, dev->id);
 927 free_mem:
 928         kfree(dev);
 929         return result;
 930 }
 931 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 932
 933 /**
 934  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 935  *                                        thermal zone.
 936  * @tz:         pointer to a struct thermal_zone_device.
 937  * @trip:       indicates which trip point the cooling devices is
 938  *              associated with in this thermal zone.
 939  * @cdev:       pointer to a struct thermal_cooling_device.
 940  *
 941  * This interface function unbind a thermal cooling device from the certain
 942  * trip point of a thermal zone device.
 943  * This function is usually called in the thermal zone device .unbind callback.
 944  *
 945  * Return: 0 on success, the proper error value otherwise.
 946  */
 947 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 948                                        int trip,
 949                                        struct thermal_cooling_device *cdev)
 950 {
 951         struct thermal_instance *pos, *next;
 952
 953         mutex_lock(&tz->lock);
 954         mutex_lock(&cdev->lock);
 955         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 956                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 957                         list_del(&pos->tz_node);
 958                         list_del(&pos->cdev_node);
 959                         mutex_unlock(&cdev->lock);
 960                         mutex_unlock(&tz->lock);
 961                         goto unbind;
 962                 }
 963         }
 964         mutex_unlock(&cdev->lock);
 965         mutex_unlock(&tz->lock);
 966
 967         return -ENODEV;
 968
 969 unbind:
 970         device_remove_file(&tz->device, &pos->weight_attr);
 971         device_remove_file(&tz->device, &pos->attr);
 972         sysfs_remove_link(&tz->device.kobj, pos->name);
 973         ida_simple_remove(&tz->ida, pos->id);
 974         kfree(pos);
 975         return 0;
 976 }
 977 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 978
 979 static void thermal_release(struct device *dev)
 980 {
 981         struct thermal_zone_device *tz;
 982         struct thermal_cooling_device *cdev;
 983
 984         if (!strncmp(dev_name(dev), "thermal_zone",
 985                      sizeof("thermal_zone") - 1)) {
 986                 tz = to_thermal_zone(dev);
 987                 thermal_zone_destroy_device_groups(tz);
 988                 kfree(tz);
 989         } else if (!strncmp(dev_name(dev), "cooling_device",
 990                             sizeof("cooling_device") - 1)) {
 991                 cdev = to_cooling_device(dev);
 992                 kfree(cdev);
 993         }
 994 }
 995
 996 static struct class thermal_class = {
 997         .name = "thermal",
 998         .dev_release = thermal_release,
 999 };
1000
1001 static inline
1002 void print_bind_err_msg(struct thermal_zone_device *tz,
1003                         struct thermal_cooling_device *cdev, int ret)
1004 {
1005         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
1006                 tz->type, cdev->type, ret);
1007 }
1008
1009 static void __bind(struct thermal_zone_device *tz, int mask,
1010                    struct thermal_cooling_device *cdev,
1011                    unsigned long *limits,
1012                    unsigned int weight)
1013 {
1014         int i, ret;
1015
1016         for (i = 0; i < tz->trips; i++) {
1017                 if (mask & (1 << i)) {
1018                         unsigned long upper, lower;
1019
1020                         upper = THERMAL_NO_LIMIT;
1021                         lower = THERMAL_NO_LIMIT;
1022                         if (limits) {
1023                                 lower = limits[i * 2];
1024                                 upper = limits[i * 2 + 1];
1025                         }
1026                         ret = thermal_zone_bind_cooling_device(tz, i, cdev,
1027                                                                upper, lower,
1028                                                                weight);
1029                         if (ret)
1030                                 print_bind_err_msg(tz, cdev, ret);
1031                 }
1032         }
1033 }
1034
1035 static void bind_cdev(struct thermal_cooling_device *cdev)
1036 {
1037         int i, ret;
1038         const struct thermal_zone_params *tzp;
1039         struct thermal_zone_device *pos = NULL;
1040
1041         mutex_lock(&thermal_list_lock);
1042
1043         list_for_each_entry(pos, &thermal_tz_list, node) {
1044                 if (!pos->tzp && !pos->ops->bind)
1045                         continue;
1046
1047                 if (pos->ops->bind) {
1048                         ret = pos->ops->bind(pos, cdev);
1049                         if (ret)
1050                                 print_bind_err_msg(pos, cdev, ret);
1051                         continue;
1052                 }
1053
1054                 tzp = pos->tzp;
1055                 if (!tzp || !tzp->tbp)
1056                         continue;
1057
1058                 for (i = 0; i < tzp->num_tbps; i++) {
1059                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1060                                 continue;
1061                         if (tzp->tbp[i].match(pos, cdev))
1062                                 continue;
1063                         tzp->tbp[i].cdev = cdev;
1064                         __bind(pos, tzp->tbp[i].trip_mask, cdev,
1065                                tzp->tbp[i].binding_limits,
1066                                tzp->tbp[i].weight);
1067                 }
1068         }
1069
1070         mutex_unlock(&thermal_list_lock);
1071 }
1072
1073 /**
1074  * __thermal_cooling_device_register() - register a new thermal cooling device
1075  * @np:         a pointer to a device tree node.
1076  * @type:       the thermal cooling device type.
1077  * @devdata:    device private data.
1078  * @ops:                standard thermal cooling devices callbacks.
1079  *
1080  * This interface function adds a new thermal cooling device (fan/processor/...)
1081  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1082  * to all the thermal zone devices registered at the same time.
1083  * It also gives the opportunity to link the cooling device to a device tree
1084  * node, so that it can be bound to a thermal zone created out of device tree.
1085  *
1086  * Return: a pointer to the created struct thermal_cooling_device or an
1087  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1088  */
1089 static struct thermal_cooling_device *
1090 __thermal_cooling_device_register(struct device_node *np,
1091                                   const char *type, void *devdata,
1092                                   const struct thermal_cooling_device_ops *ops)
1093 {
1094         struct thermal_cooling_device *cdev;
1095         struct thermal_zone_device *pos = NULL;
1096         int result;
1097
1098         if (type && strlen(type) >= THERMAL_NAME_LENGTH)
1099                 return ERR_PTR(-EINVAL);
1100
1101         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
1102             !ops->set_cur_state)
1103                 return ERR_PTR(-EINVAL);
1104
1105         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
1106         if (!cdev)
1107                 return ERR_PTR(-ENOMEM);
1108
1109         result = ida_simple_get(&thermal_cdev_ida, 0, 0, GFP_KERNEL);
1110         if (result < 0) {
1111                 kfree(cdev);
1112                 return ERR_PTR(result);
1113         }
1114
1115         cdev->id = result;
1116         strlcpy(cdev->type, type ? : "", sizeof(cdev->type));
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         result = device_register(&cdev->device);
1127         if (result) {
1128                 ida_simple_remove(&thermal_cdev_ida, cdev->id);
1129                 put_device(&cdev->device);
1130                 return ERR_PTR(result);
1131         }
1132
1133         /* Add 'this' new cdev to the global cdev list */
1134         mutex_lock(&thermal_list_lock);
1135         list_add(&cdev->node, &thermal_cdev_list);
1136         mutex_unlock(&thermal_list_lock);
1137
1138         /* Update binding information for 'this' new cdev */
1139         bind_cdev(cdev);
1140
1141         mutex_lock(&thermal_list_lock);
1142         list_for_each_entry(pos, &thermal_tz_list, node)
1143                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
1144                         thermal_zone_device_update(pos,
1145                                                    THERMAL_EVENT_UNSPECIFIED);
1146         mutex_unlock(&thermal_list_lock);
1147
1148         return cdev;
1149 }
1150
1151 /**
1152  * thermal_cooling_device_register() - register a new thermal cooling device
1153  * @type:       the thermal cooling device type.
1154  * @devdata:    device private data.
1155  * @ops:                standard thermal cooling devices callbacks.
1156  *
1157  * This interface function adds a new thermal cooling device (fan/processor/...)
1158  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1159  * to all the thermal zone devices registered at the same time.
1160  *
1161  * Return: a pointer to the created struct thermal_cooling_device or an
1162  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1163  */
1164 struct thermal_cooling_device *
1165 thermal_cooling_device_register(const char *type, void *devdata,
1166                                 const struct thermal_cooling_device_ops *ops)
1167 {
1168         return __thermal_cooling_device_register(NULL, type, devdata, ops);
1169 }
1170 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1171
1172 /**
1173  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1174  * @np:         a pointer to a device tree node.
1175  * @type:       the thermal cooling device type.
1176  * @devdata:    device private data.
1177  * @ops:                standard thermal cooling devices callbacks.
1178  *
1179  * This function will register a cooling device with device tree node reference.
1180  * This interface function adds a new thermal cooling device (fan/processor/...)
1181  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1182  * to all the thermal zone devices registered at the same time.
1183  *
1184  * Return: a pointer to the created struct thermal_cooling_device or an
1185  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1186  */
1187 struct thermal_cooling_device *
1188 thermal_of_cooling_device_register(struct device_node *np,
1189                                    const char *type, void *devdata,
1190                                    const struct thermal_cooling_device_ops *ops)
1191 {
1192         return __thermal_cooling_device_register(np, type, devdata, ops);
1193 }
1194 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1195
1196 static void thermal_cooling_device_release(struct device *dev, void *res)
1197 {
1198         thermal_cooling_device_unregister(
1199                                 *(struct thermal_cooling_device **)res);
1200 }
1201
1202 /**
1203  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1204  *                                             device
1205  * @dev:        a valid struct device pointer of a sensor device.
1206  * @np:         a pointer to a device tree node.
1207  * @type:       the thermal cooling device type.
1208  * @devdata:    device private data.
1209  * @ops:        standard thermal cooling devices callbacks.
1210  *
1211  * This function will register a cooling device with device tree node reference.
1212  * This interface function adds a new thermal cooling device (fan/processor/...)
1213  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1214  * to all the thermal zone devices registered at the same time.
1215  *
1216  * Return: a pointer to the created struct thermal_cooling_device or an
1217  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1218  */
1219 struct thermal_cooling_device *
1220 devm_thermal_of_cooling_device_register(struct device *dev,
1221                                 struct device_node *np,
1222                                 char *type, void *devdata,
1223                                 const struct thermal_cooling_device_ops *ops)
1224 {
1225         struct thermal_cooling_device **ptr, *tcd;
1226
1227         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1228                            GFP_KERNEL);
1229         if (!ptr)
1230                 return ERR_PTR(-ENOMEM);
1231
1232         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1233         if (IS_ERR(tcd)) {
1234                 devres_free(ptr);
1235                 return tcd;
1236         }
1237
1238         *ptr = tcd;
1239         devres_add(dev, ptr);
1240
1241         return tcd;
1242 }
1243 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1244
1245 static void __unbind(struct thermal_zone_device *tz, int mask,
1246                      struct thermal_cooling_device *cdev)
1247 {
1248         int i;
1249
1250         for (i = 0; i < tz->trips; i++)
1251                 if (mask & (1 << i))
1252                         thermal_zone_unbind_cooling_device(tz, i, cdev);
1253 }
1254
1255 /**
1256  * thermal_cooling_device_unregister - removes a thermal cooling device
1257  * @cdev:       the thermal cooling device to remove.
1258  *
1259  * thermal_cooling_device_unregister() must be called when a registered
1260  * thermal cooling device is no longer needed.
1261  */
1262 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1263 {
1264         int i;
1265         const struct thermal_zone_params *tzp;
1266         struct thermal_zone_device *tz;
1267         struct thermal_cooling_device *pos = NULL;
1268
1269         if (!cdev)
1270                 return;
1271
1272         mutex_lock(&thermal_list_lock);
1273         list_for_each_entry(pos, &thermal_cdev_list, node)
1274                 if (pos == cdev)
1275                         break;
1276         if (pos != cdev) {
1277                 /* thermal cooling device not found */
1278                 mutex_unlock(&thermal_list_lock);
1279                 return;
1280         }
1281         list_del(&cdev->node);
1282
1283         /* Unbind all thermal zones associated with 'this' cdev */
1284         list_for_each_entry(tz, &thermal_tz_list, node) {
1285                 if (tz->ops->unbind) {
1286                         tz->ops->unbind(tz, cdev);
1287                         continue;
1288                 }
1289
1290                 if (!tz->tzp || !tz->tzp->tbp)
1291                         continue;
1292
1293                 tzp = tz->tzp;
1294                 for (i = 0; i < tzp->num_tbps; i++) {
1295                         if (tzp->tbp[i].cdev == cdev) {
1296                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1297                                 tzp->tbp[i].cdev = NULL;
1298                         }
1299                 }
1300         }
1301
1302         mutex_unlock(&thermal_list_lock);
1303
1304         ida_simple_remove(&thermal_cdev_ida, cdev->id);
1305         device_del(&cdev->device);
1306         thermal_cooling_device_destroy_sysfs(cdev);
1307         put_device(&cdev->device);
1308 }
1309 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1310
1311 static void bind_tz(struct thermal_zone_device *tz)
1312 {
1313         int i, ret;
1314         struct thermal_cooling_device *pos = NULL;
1315         const struct thermal_zone_params *tzp = tz->tzp;
1316
1317         if (!tzp && !tz->ops->bind)
1318                 return;
1319
1320         mutex_lock(&thermal_list_lock);
1321
1322         /* If there is ops->bind, try to use ops->bind */
1323         if (tz->ops->bind) {
1324                 list_for_each_entry(pos, &thermal_cdev_list, node) {
1325                         ret = tz->ops->bind(tz, pos);
1326                         if (ret)
1327                                 print_bind_err_msg(tz, pos, ret);
1328                 }
1329                 goto exit;
1330         }
1331
1332         if (!tzp || !tzp->tbp)
1333                 goto exit;
1334
1335         list_for_each_entry(pos, &thermal_cdev_list, node) {
1336                 for (i = 0; i < tzp->num_tbps; i++) {
1337                         if (tzp->tbp[i].cdev || !tzp->tbp[i].match)
1338                                 continue;
1339                         if (tzp->tbp[i].match(tz, pos))
1340                                 continue;
1341                         tzp->tbp[i].cdev = pos;
1342                         __bind(tz, tzp->tbp[i].trip_mask, pos,
1343                                tzp->tbp[i].binding_limits,
1344                                tzp->tbp[i].weight);
1345                 }
1346         }
1347 exit:
1348         mutex_unlock(&thermal_list_lock);
1349 }
1350
1351 /**
1352  * thermal_zone_device_register() - register a new thermal zone device
1353  * @type:       the thermal zone device type
1354  * @trips:      the number of trip points the thermal zone support
1355  * @mask:       a bit string indicating the writeablility of trip points
1356  * @devdata:    private device data
1357  * @ops:        standard thermal zone device callbacks
1358  * @tzp:        thermal zone platform parameters
1359  * @passive_delay: number of milliseconds to wait between polls when
1360  *                 performing passive cooling
1361  * @polling_delay: number of milliseconds to wait between polls when checking
1362  *                 whether trip points have been crossed (0 for interrupt
1363  *                 driven systems)
1364  *
1365  * This interface function adds a new thermal zone device (sensor) to
1366  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1367  * thermal cooling devices registered at the same time.
1368  * thermal_zone_device_unregister() must be called when the device is no
1369  * longer needed. The passive cooling depends on the .get_trend() return value.
1370  *
1371  * Return: a pointer to the created struct thermal_zone_device or an
1372  * in case of error, an ERR_PTR. Caller must check return value with
1373  * IS_ERR*() helpers.
1374  */
1375 struct thermal_zone_device *
1376 thermal_zone_device_register(const char *type, int trips, int mask,
1377                              void *devdata, struct thermal_zone_device_ops *ops,
1378                              struct thermal_zone_params *tzp, int passive_delay,
1379                              int polling_delay)
1380 {
1381         struct thermal_zone_device *tz;
1382         enum thermal_trip_type trip_type;
1383         int trip_temp;
1384         int id;
1385         int result;
1386         int count;
1387         struct thermal_governor *governor;
1388
1389         if (!type || strlen(type) == 0) {
1390                 pr_err("Error: No thermal zone type defined\n");
1391                 return ERR_PTR(-EINVAL);
1392         }
1393
1394         if (type && strlen(type) >= THERMAL_NAME_LENGTH) {
1395                 pr_err("Error: Thermal zone name (%s) too long, should be under %d chars\n",
1396                        type, THERMAL_NAME_LENGTH);
1397                 return ERR_PTR(-EINVAL);
1398         }
1399
1400         if (trips > THERMAL_MAX_TRIPS || trips < 0 || mask >> trips) {
1401                 pr_err("Error: Incorrect number of thermal trips\n");
1402                 return ERR_PTR(-EINVAL);
1403         }
1404
1405         if (!ops) {
1406                 pr_err("Error: Thermal zone device ops not defined\n");
1407                 return ERR_PTR(-EINVAL);
1408         }
1409
1410         if (trips > 0 && (!ops->get_trip_type || !ops->get_trip_temp))
1411                 return ERR_PTR(-EINVAL);
1412
1413         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1414         if (!tz)
1415                 return ERR_PTR(-ENOMEM);
1416
1417         INIT_LIST_HEAD(&tz->thermal_instances);
1418         ida_init(&tz->ida);
1419         mutex_init(&tz->lock);
1420         id = ida_simple_get(&thermal_tz_ida, 0, 0, GFP_KERNEL);
1421         if (id < 0) {
1422                 result = id;
1423                 goto free_tz;
1424         }
1425
1426         tz->id = id;
1427         strlcpy(tz->type, type, sizeof(tz->type));
1428         tz->ops = ops;
1429         tz->tzp = tzp;
1430         tz->device.class = &thermal_class;
1431         tz->devdata = devdata;
1432         tz->trips = trips;
1433         tz->passive_delay = passive_delay;
1434         tz->polling_delay = polling_delay;
1435
1436         /* sys I/F */
1437         /* Add nodes that are always present via .groups */
1438         result = thermal_zone_create_device_groups(tz, mask);
1439         if (result)
1440                 goto remove_id;
1441
1442         /* A new thermal zone needs to be updated anyway. */
1443         atomic_set(&tz->need_update, 1);
1444
1445         dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1446         result = device_register(&tz->device);
1447         if (result)
1448                 goto release_device;
1449
1450         for (count = 0; count < trips; count++) {
1451                 if (tz->ops->get_trip_type(tz, count, &trip_type))
1452                         set_bit(count, &tz->trips_disabled);
1453                 if (tz->ops->get_trip_temp(tz, count, &trip_temp))
1454                         set_bit(count, &tz->trips_disabled);
1455                 /* Check for bogus trip points */
1456                 if (trip_temp == 0)
1457                         set_bit(count, &tz->trips_disabled);
1458         }
1459
1460         /* Update 'this' zone's governor information */
1461         mutex_lock(&thermal_governor_lock);
1462
1463         if (tz->tzp)
1464                 governor = __find_governor(tz->tzp->governor_name);
1465         else
1466                 governor = def_governor;
1467
1468         result = thermal_set_governor(tz, governor);
1469         if (result) {
1470                 mutex_unlock(&thermal_governor_lock);
1471                 goto unregister;
1472         }
1473
1474         mutex_unlock(&thermal_governor_lock);
1475
1476         if (!tz->tzp || !tz->tzp->no_hwmon) {
1477                 result = thermal_add_hwmon_sysfs(tz);
1478                 if (result)
1479                         goto unregister;
1480         }
1481
1482         mutex_lock(&thermal_list_lock);
1483         list_add_tail(&tz->node, &thermal_tz_list);
1484         mutex_unlock(&thermal_list_lock);
1485
1486         /* Bind cooling devices for this zone */
1487         bind_tz(tz);
1488
1489         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1490
1491         thermal_zone_device_reset(tz);
1492         /* Update the new thermal zone and mark it as already updated. */
1493         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1494                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1495
1496         thermal_notify_tz_create(tz->id, tz->type);
1497
1498         return tz;
1499
1500 unregister:
1501         device_del(&tz->device);
1502 release_device:
1503         put_device(&tz->device);
1504         tz = NULL;
1505 remove_id:
1506         ida_simple_remove(&thermal_tz_ida, id);
1507 free_tz:
1508         kfree(tz);
1509         return ERR_PTR(result);
1510 }
1511 EXPORT_SYMBOL_GPL(thermal_zone_device_register);
1512
1513 /**
1514  * thermal_device_unregister - removes the registered thermal zone device
1515  * @tz: the thermal zone device to remove
1516  */
1517 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1518 {
1519         int i, tz_id;
1520         const struct thermal_zone_params *tzp;
1521         struct thermal_cooling_device *cdev;
1522         struct thermal_zone_device *pos = NULL;
1523
1524         if (!tz)
1525                 return;
1526
1527         tzp = tz->tzp;
1528         tz_id = tz->id;
1529
1530         mutex_lock(&thermal_list_lock);
1531         list_for_each_entry(pos, &thermal_tz_list, node)
1532                 if (pos == tz)
1533                         break;
1534         if (pos != tz) {
1535                 /* thermal zone device not found */
1536                 mutex_unlock(&thermal_list_lock);
1537                 return;
1538         }
1539         list_del(&tz->node);
1540
1541         /* Unbind all cdevs associated with 'this' thermal zone */
1542         list_for_each_entry(cdev, &thermal_cdev_list, node) {
1543                 if (tz->ops->unbind) {
1544                         tz->ops->unbind(tz, cdev);
1545                         continue;
1546                 }
1547
1548                 if (!tzp || !tzp->tbp)
1549                         break;
1550
1551                 for (i = 0; i < tzp->num_tbps; i++) {
1552                         if (tzp->tbp[i].cdev == cdev) {
1553                                 __unbind(tz, tzp->tbp[i].trip_mask, cdev);
1554                                 tzp->tbp[i].cdev = NULL;
1555                         }
1556                 }
1557         }
1558
1559         mutex_unlock(&thermal_list_lock);
1560
1561         cancel_delayed_work_sync(&tz->poll_queue);
1562
1563         thermal_set_governor(tz, NULL);
1564
1565         thermal_remove_hwmon_sysfs(tz);
1566         ida_simple_remove(&thermal_tz_ida, tz->id);
1567         ida_destroy(&tz->ida);
1568         mutex_destroy(&tz->lock);
1569         device_unregister(&tz->device);
1570
1571         thermal_notify_tz_delete(tz_id);
1572 }
1573 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1574
1575 /**
1576  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1577  * @name: thermal zone name to fetch the temperature
1578  *
1579  * When only one zone is found with the passed name, returns a reference to it.
1580  *
1581  * Return: On success returns a reference to an unique thermal zone with
1582  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1583  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1584  */
1585 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1586 {
1587         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1588         unsigned int found = 0;
1589
1590         if (!name)
1591                 goto exit;
1592
1593         mutex_lock(&thermal_list_lock);
1594         list_for_each_entry(pos, &thermal_tz_list, node)
1595                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1596                         found++;
1597                         ref = pos;
1598                 }
1599         mutex_unlock(&thermal_list_lock);
1600
1601         /* nothing has been found, thus an error code for it */
1602         if (found == 0)
1603                 ref = ERR_PTR(-ENODEV);
1604         else if (found > 1)
1605         /* Success only when an unique zone is found */
1606                 ref = ERR_PTR(-EEXIST);
1607
1608 exit:
1609         return ref;
1610 }
1611 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1612
1613 static int thermal_pm_notify(struct notifier_block *nb,
1614                              unsigned long mode, void *_unused)
1615 {
1616         struct thermal_zone_device *tz;
1617
1618         switch (mode) {
1619         case PM_HIBERNATION_PREPARE:
1620         case PM_RESTORE_PREPARE:
1621         case PM_SUSPEND_PREPARE:
1622                 atomic_set(&in_suspend, 1);
1623                 break;
1624         case PM_POST_HIBERNATION:
1625         case PM_POST_RESTORE:
1626         case PM_POST_SUSPEND:
1627                 atomic_set(&in_suspend, 0);
1628                 list_for_each_entry(tz, &thermal_tz_list, node) {
1629                         if (!thermal_zone_device_is_enabled(tz))
1630                                 continue;
1631
1632                         thermal_zone_device_init(tz);
1633                         thermal_zone_device_update(tz,
1634                                                    THERMAL_EVENT_UNSPECIFIED);
1635                 }
1636                 break;
1637         default:
1638                 break;
1639         }
1640         return 0;
1641 }
1642
1643 static struct notifier_block thermal_pm_nb = {
1644         .notifier_call = thermal_pm_notify,
1645 };
1646
1647 static int __init thermal_init(void)
1648 {
1649         int result;
1650
1651         result = thermal_netlink_init();
1652         if (result)
1653                 goto error;
1654
1655         mutex_init(&poweroff_lock);
1656         result = thermal_register_governors();
1657         if (result)
1658                 goto error;
1659
1660         result = class_register(&thermal_class);
1661         if (result)
1662                 goto unregister_governors;
1663
1664         result = of_parse_thermal_zones();
1665         if (result)
1666                 goto unregister_class;
1667
1668         result = register_pm_notifier(&thermal_pm_nb);
1669         if (result)
1670                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1671                         result);
1672
1673         return 0;
1674
1675 unregister_class:
1676         class_unregister(&thermal_class);
1677 unregister_governors:
1678         thermal_unregister_governors();
1679 error:
1680         ida_destroy(&thermal_tz_ida);
1681         ida_destroy(&thermal_cdev_ida);
1682         mutex_destroy(&thermal_list_lock);
1683         mutex_destroy(&thermal_governor_lock);
1684         mutex_destroy(&poweroff_lock);
1685         return result;
1686 }
1687 postcore_initcall(thermal_init);