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 <[email protected]>
   7  *  Copyright (C) 2008 Sujith Thomas <[email protected]>
   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/list_sort.h>
  19 #include <linux/thermal.h>
  20 #include <linux/reboot.h>
  21 #include <linux/string.h>
  22 #include <linux/of.h>
  23 #include <linux/suspend.h>
  24
  25 #define CREATE_TRACE_POINTS
  26 #include "thermal_trace.h"
  27
  28 #include "thermal_core.h"
  29 #include "thermal_hwmon.h"
  30
  31 static DEFINE_IDA(thermal_tz_ida);
  32 static DEFINE_IDA(thermal_cdev_ida);
  33
  34 static LIST_HEAD(thermal_tz_list);
  35 static LIST_HEAD(thermal_cdev_list);
  36 static LIST_HEAD(thermal_governor_list);
  37
  38 static DEFINE_MUTEX(thermal_list_lock);
  39 static DEFINE_MUTEX(thermal_governor_lock);
  40
  41 static struct thermal_governor *def_governor;
  42
  43 /*
  44  * Governor section: set of functions to handle thermal governors
  45  *
  46  * Functions to help in the life cycle of thermal governors within
  47  * the thermal core and by the thermal governor code.
  48  */
  49
  50 static struct thermal_governor *__find_governor(const char *name)
  51 {
  52         struct thermal_governor *pos;
  53
  54         if (!name || !name[0])
  55                 return def_governor;
  56
  57         list_for_each_entry(pos, &thermal_governor_list, governor_list)
  58                 if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
  59                         return pos;
  60
  61         return NULL;
  62 }
  63
  64 /**
  65  * bind_previous_governor() - bind the previous governor of the thermal zone
  66  * @tz:         a valid pointer to a struct thermal_zone_device
  67  * @failed_gov_name:    the name of the governor that failed to register
  68  *
  69  * Register the previous governor of the thermal zone after a new
  70  * governor has failed to be bound.
  71  */
  72 static void bind_previous_governor(struct thermal_zone_device *tz,
  73                                    const char *failed_gov_name)
  74 {
  75         if (tz->governor && tz->governor->bind_to_tz) {
  76                 if (tz->governor->bind_to_tz(tz)) {
  77                         dev_err(&tz->device,
  78                                 "governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
  79                                 failed_gov_name, tz->governor->name, tz->type);
  80                         tz->governor = NULL;
  81                 }
  82         }
  83 }
  84
  85 /**
  86  * thermal_set_governor() - Switch to another governor
  87  * @tz:         a valid pointer to a struct thermal_zone_device
  88  * @new_gov:    pointer to the new governor
  89  *
  90  * Change the governor of thermal zone @tz.
  91  *
  92  * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
  93  */
  94 static int thermal_set_governor(struct thermal_zone_device *tz,
  95                                 struct thermal_governor *new_gov)
  96 {
  97         int ret = 0;
  98
  99         if (tz->governor && tz->governor->unbind_from_tz)
 100                 tz->governor->unbind_from_tz(tz);
 101
 102         if (new_gov && new_gov->bind_to_tz) {
 103                 ret = new_gov->bind_to_tz(tz);
 104                 if (ret) {
 105                         bind_previous_governor(tz, new_gov->name);
 106
 107                         return ret;
 108                 }
 109         }
 110
 111         tz->governor = new_gov;
 112
 113         return ret;
 114 }
 115
 116 int thermal_register_governor(struct thermal_governor *governor)
 117 {
 118         int err;
 119         const char *name;
 120         struct thermal_zone_device *pos;
 121
 122         if (!governor)
 123                 return -EINVAL;
 124
 125         mutex_lock(&thermal_governor_lock);
 126
 127         err = -EBUSY;
 128         if (!__find_governor(governor->name)) {
 129                 bool match_default;
 130
 131                 err = 0;
 132                 list_add(&governor->governor_list, &thermal_governor_list);
 133                 match_default = !strncmp(governor->name,
 134                                          DEFAULT_THERMAL_GOVERNOR,
 135                                          THERMAL_NAME_LENGTH);
 136
 137                 if (!def_governor && match_default)
 138                         def_governor = governor;
 139         }
 140
 141         mutex_lock(&thermal_list_lock);
 142
 143         list_for_each_entry(pos, &thermal_tz_list, node) {
 144                 /*
 145                  * only thermal zones with specified tz->tzp->governor_name
 146                  * may run with tz->govenor unset
 147                  */
 148                 if (pos->governor)
 149                         continue;
 150
 151                 name = pos->tzp->governor_name;
 152
 153                 if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
 154                         int ret;
 155
 156                         ret = thermal_set_governor(pos, governor);
 157                         if (ret)
 158                                 dev_err(&pos->device,
 159                                         "Failed to set governor %s for thermal zone %s: %d\n",
 160                                         governor->name, pos->type, ret);
 161                 }
 162         }
 163
 164         mutex_unlock(&thermal_list_lock);
 165         mutex_unlock(&thermal_governor_lock);
 166
 167         return err;
 168 }
 169
 170 void thermal_unregister_governor(struct thermal_governor *governor)
 171 {
 172         struct thermal_zone_device *pos;
 173
 174         if (!governor)
 175                 return;
 176
 177         mutex_lock(&thermal_governor_lock);
 178
 179         if (!__find_governor(governor->name))
 180                 goto exit;
 181
 182         mutex_lock(&thermal_list_lock);
 183
 184         list_for_each_entry(pos, &thermal_tz_list, node) {
 185                 if (!strncasecmp(pos->governor->name, governor->name,
 186                                  THERMAL_NAME_LENGTH))
 187                         thermal_set_governor(pos, NULL);
 188         }
 189
 190         mutex_unlock(&thermal_list_lock);
 191         list_del(&governor->governor_list);
 192 exit:
 193         mutex_unlock(&thermal_governor_lock);
 194 }
 195
 196 int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
 197                                    char *policy)
 198 {
 199         struct thermal_governor *gov;
 200         int ret = -EINVAL;
 201
 202         mutex_lock(&thermal_governor_lock);
 203         mutex_lock(&tz->lock);
 204
 205         gov = __find_governor(strim(policy));
 206         if (!gov)
 207                 goto exit;
 208
 209         ret = thermal_set_governor(tz, gov);
 210
 211 exit:
 212         mutex_unlock(&tz->lock);
 213         mutex_unlock(&thermal_governor_lock);
 214
 215         thermal_notify_tz_gov_change(tz, policy);
 216
 217         return ret;
 218 }
 219
 220 int thermal_build_list_of_policies(char *buf)
 221 {
 222         struct thermal_governor *pos;
 223         ssize_t count = 0;
 224
 225         mutex_lock(&thermal_governor_lock);
 226
 227         list_for_each_entry(pos, &thermal_governor_list, governor_list) {
 228                 count += sysfs_emit_at(buf, count, "%s ", pos->name);
 229         }
 230         count += sysfs_emit_at(buf, count, "\n");
 231
 232         mutex_unlock(&thermal_governor_lock);
 233
 234         return count;
 235 }
 236
 237 static void __init thermal_unregister_governors(void)
 238 {
 239         struct thermal_governor **governor;
 240
 241         for_each_governor_table(governor)
 242                 thermal_unregister_governor(*governor);
 243 }
 244
 245 static int __init thermal_register_governors(void)
 246 {
 247         int ret = 0;
 248         struct thermal_governor **governor;
 249
 250         for_each_governor_table(governor) {
 251                 ret = thermal_register_governor(*governor);
 252                 if (ret) {
 253                         pr_err("Failed to register governor: '%s'",
 254                                (*governor)->name);
 255                         break;
 256                 }
 257
 258                 pr_info("Registered thermal governor '%s'",
 259                         (*governor)->name);
 260         }
 261
 262         if (ret) {
 263                 struct thermal_governor **gov;
 264
 265                 for_each_governor_table(gov) {
 266                         if (gov == governor)
 267                                 break;
 268                         thermal_unregister_governor(*gov);
 269                 }
 270         }
 271
 272         return ret;
 273 }
 274
 275 static int __thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 276                                           enum thermal_device_mode mode)
 277 {
 278         if (tz->ops.change_mode) {
 279                 int ret;
 280
 281                 ret = tz->ops.change_mode(tz, mode);
 282                 if (ret)
 283                         return ret;
 284         }
 285
 286         tz->mode = mode;
 287
 288         return 0;
 289 }
 290
 291 static void thermal_zone_broken_disable(struct thermal_zone_device *tz)
 292 {
 293         struct thermal_trip_desc *td;
 294
 295         dev_err(&tz->device, "Unable to get temperature, disabling!\n");
 296         /*
 297          * This function only runs for enabled thermal zones, so no need to
 298          * check for the current mode.
 299          */
 300         __thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 301         thermal_notify_tz_disable(tz);
 302
 303         for_each_trip_desc(tz, td) {
 304                 if (td->trip.type == THERMAL_TRIP_CRITICAL &&
 305                     td->trip.temperature > THERMAL_TEMP_INVALID) {
 306                         dev_crit(&tz->device,
 307                                  "Disabled thermal zone with critical trip point\n");
 308                         return;
 309                 }
 310         }
 311 }
 312
 313 /*
 314  * Zone update section: main control loop applied to each zone while monitoring
 315  * in polling mode. The monitoring is done using a workqueue.
 316  * Same update may be done on a zone by calling thermal_zone_device_update().
 317  *
 318  * An update means:
 319  * - Non-critical trips will invoke the governor responsible for that zone;
 320  * - Hot trips will produce a notification to userspace;
 321  * - Critical trip point will cause a system shutdown.
 322  */
 323 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 324                                             unsigned long delay)
 325 {
 326         if (delay)
 327                 mod_delayed_work(system_freezable_power_efficient_wq,
 328                                  &tz->poll_queue, delay);
 329         else
 330                 cancel_delayed_work(&tz->poll_queue);
 331 }
 332
 333 static void thermal_zone_recheck(struct thermal_zone_device *tz, int error)
 334 {
 335         if (error == -EAGAIN) {
 336                 thermal_zone_device_set_polling(tz, THERMAL_RECHECK_DELAY);
 337                 return;
 338         }
 339
 340         /*
 341          * Print the message once to reduce log noise.  It will be followed by
 342          * another one if the temperature cannot be determined after multiple
 343          * attempts.
 344          */
 345         if (tz->recheck_delay_jiffies == THERMAL_RECHECK_DELAY)
 346                 dev_info(&tz->device, "Temperature check failed (%d)\n", error);
 347
 348         thermal_zone_device_set_polling(tz, tz->recheck_delay_jiffies);
 349
 350         tz->recheck_delay_jiffies += max(tz->recheck_delay_jiffies >> 1, 1ULL);
 351         if (tz->recheck_delay_jiffies > THERMAL_MAX_RECHECK_DELAY) {
 352                 thermal_zone_broken_disable(tz);
 353                 /*
 354                  * Restore the original recheck delay value to allow the thermal
 355                  * zone to try to recover when it is reenabled by user space.
 356                  */
 357                 tz->recheck_delay_jiffies = THERMAL_RECHECK_DELAY;
 358         }
 359 }
 360
 361 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 362 {
 363         if (tz->mode != THERMAL_DEVICE_ENABLED)
 364                 thermal_zone_device_set_polling(tz, 0);
 365         else if (tz->passive > 0)
 366                 thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
 367         else if (tz->polling_delay_jiffies)
 368                 thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
 369 }
 370
 371 static struct thermal_governor *thermal_get_tz_governor(struct thermal_zone_device *tz)
 372 {
 373         if (tz->governor)
 374                 return tz->governor;
 375
 376         return def_governor;
 377 }
 378
 379 void thermal_governor_update_tz(struct thermal_zone_device *tz,
 380                                 enum thermal_notify_event reason)
 381 {
 382         if (!tz->governor || !tz->governor->update_tz)
 383                 return;
 384
 385         tz->governor->update_tz(tz, reason);
 386 }
 387
 388 static void thermal_zone_device_halt(struct thermal_zone_device *tz, bool shutdown)
 389 {
 390         /*
 391          * poweroff_delay_ms must be a carefully profiled positive value.
 392          * Its a must for forced_emergency_poweroff_work to be scheduled.
 393          */
 394         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 395         const char *msg = "Temperature too high";
 396
 397         dev_emerg(&tz->device, "%s: critical temperature reached\n", tz->type);
 398
 399         if (shutdown)
 400                 hw_protection_shutdown(msg, poweroff_delay_ms);
 401         else
 402                 hw_protection_reboot(msg, poweroff_delay_ms);
 403 }
 404
 405 void thermal_zone_device_critical(struct thermal_zone_device *tz)
 406 {
 407         thermal_zone_device_halt(tz, true);
 408 }
 409 EXPORT_SYMBOL(thermal_zone_device_critical);
 410
 411 void thermal_zone_device_critical_reboot(struct thermal_zone_device *tz)
 412 {
 413         thermal_zone_device_halt(tz, false);
 414 }
 415
 416 static void handle_critical_trips(struct thermal_zone_device *tz,
 417                                   const struct thermal_trip *trip)
 418 {
 419         trace_thermal_zone_trip(tz, thermal_zone_trip_id(tz, trip), trip->type);
 420
 421         if (trip->type == THERMAL_TRIP_CRITICAL)
 422                 tz->ops.critical(tz);
 423         else if (tz->ops.hot)
 424                 tz->ops.hot(tz);
 425 }
 426
 427 static void handle_thermal_trip(struct thermal_zone_device *tz,
 428                                 struct thermal_trip_desc *td,
 429                                 struct list_head *way_up_list,
 430                                 struct list_head *way_down_list)
 431 {
 432         const struct thermal_trip *trip = &td->trip;
 433         int old_threshold;
 434
 435         if (trip->temperature == THERMAL_TEMP_INVALID)
 436                 return;
 437
 438         /*
 439          * If the trip temperature or hysteresis has been updated recently,
 440          * the threshold needs to be computed again using the new values.
 441          * However, its initial value still reflects the old ones and that
 442          * is what needs to be compared with the previous zone temperature
 443          * to decide which action to take.
 444          */
 445         old_threshold = td->threshold;
 446         td->threshold = trip->temperature;
 447
 448         if (tz->last_temperature >= old_threshold &&
 449             tz->last_temperature != THERMAL_TEMP_INIT) {
 450                 /*
 451                  * Mitigation is under way, so it needs to stop if the zone
 452                  * temperature falls below the low temperature of the trip.
 453                  * In that case, the trip temperature becomes the new threshold.
 454                  */
 455                 if (tz->temperature < trip->temperature - trip->hysteresis) {
 456                         list_add(&td->notify_list_node, way_down_list);
 457                         td->notify_temp = trip->temperature - trip->hysteresis;
 458
 459                         if (trip->type == THERMAL_TRIP_PASSIVE) {
 460                                 tz->passive--;
 461                                 WARN_ON(tz->passive < 0);
 462                         }
 463                 } else {
 464                         td->threshold -= trip->hysteresis;
 465                 }
 466         } else if (tz->temperature >= trip->temperature) {
 467                 /*
 468                  * There is no mitigation under way, so it needs to be started
 469                  * if the zone temperature exceeds the trip one.  The new
 470                  * threshold is then set to the low temperature of the trip.
 471                  */
 472                 list_add_tail(&td->notify_list_node, way_up_list);
 473                 td->notify_temp = trip->temperature;
 474                 td->threshold -= trip->hysteresis;
 475
 476                 if (trip->type == THERMAL_TRIP_PASSIVE)
 477                         tz->passive++;
 478                 else if (trip->type == THERMAL_TRIP_CRITICAL ||
 479                          trip->type == THERMAL_TRIP_HOT)
 480                         handle_critical_trips(tz, trip);
 481         }
 482 }
 483
 484 static void thermal_zone_device_check(struct work_struct *work)
 485 {
 486         struct thermal_zone_device *tz = container_of(work, struct
 487                                                       thermal_zone_device,
 488                                                       poll_queue.work);
 489         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 490 }
 491
 492 static void thermal_zone_device_init(struct thermal_zone_device *tz)
 493 {
 494         struct thermal_instance *pos;
 495
 496         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
 497
 498         tz->temperature = THERMAL_TEMP_INIT;
 499         tz->passive = 0;
 500         tz->prev_low_trip = -INT_MAX;
 501         tz->prev_high_trip = INT_MAX;
 502         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 503                 pos->initialized = false;
 504 }
 505
 506 static void thermal_governor_trip_crossed(struct thermal_governor *governor,
 507                                           struct thermal_zone_device *tz,
 508                                           const struct thermal_trip *trip,
 509                                           bool crossed_up)
 510 {
 511         if (trip->type == THERMAL_TRIP_HOT || trip->type == THERMAL_TRIP_CRITICAL)
 512                 return;
 513
 514         if (governor->trip_crossed)
 515                 governor->trip_crossed(tz, trip, crossed_up);
 516 }
 517
 518 static void thermal_trip_crossed(struct thermal_zone_device *tz,
 519                                  const struct thermal_trip *trip,
 520                                  struct thermal_governor *governor,
 521                                  bool crossed_up)
 522 {
 523         if (crossed_up) {
 524                 thermal_notify_tz_trip_up(tz, trip);
 525                 thermal_debug_tz_trip_up(tz, trip);
 526         } else {
 527                 thermal_notify_tz_trip_down(tz, trip);
 528                 thermal_debug_tz_trip_down(tz, trip);
 529         }
 530         thermal_governor_trip_crossed(governor, tz, trip, crossed_up);
 531 }
 532
 533 static int thermal_trip_notify_cmp(void *not_used, const struct list_head *a,
 534                                    const struct list_head *b)
 535 {
 536         struct thermal_trip_desc *tda = container_of(a, struct thermal_trip_desc,
 537                                                      notify_list_node);
 538         struct thermal_trip_desc *tdb = container_of(b, struct thermal_trip_desc,
 539                                                      notify_list_node);
 540         return tda->notify_temp - tdb->notify_temp;
 541 }
 542
 543 void __thermal_zone_device_update(struct thermal_zone_device *tz,
 544                                   enum thermal_notify_event event)
 545 {
 546         struct thermal_governor *governor = thermal_get_tz_governor(tz);
 547         struct thermal_trip_desc *td;
 548         LIST_HEAD(way_down_list);
 549         LIST_HEAD(way_up_list);
 550         int temp, ret;
 551
 552         if (tz->suspended)
 553                 return;
 554
 555         if (!thermal_zone_device_is_enabled(tz))
 556                 return;
 557
 558         ret = __thermal_zone_get_temp(tz, &temp);
 559         if (ret) {
 560                 thermal_zone_recheck(tz, ret);
 561                 return;
 562         } else if (temp <= THERMAL_TEMP_INVALID) {
 563                 /*
 564                  * Special case: No valid temperature value is available, but
 565                  * the zone owner does not want the core to do anything about
 566                  * it.  Continue regular zone polling if needed, so that this
 567                  * function can be called again, but skip everything else.
 568                  */
 569                 goto monitor;
 570         }
 571
 572         tz->recheck_delay_jiffies = THERMAL_RECHECK_DELAY;
 573
 574         tz->last_temperature = tz->temperature;
 575         tz->temperature = temp;
 576
 577         trace_thermal_temperature(tz);
 578
 579         thermal_genl_sampling_temp(tz->id, temp);
 580
 581         tz->notify_event = event;
 582
 583         for_each_trip_desc(tz, td)
 584                 handle_thermal_trip(tz, td, &way_up_list, &way_down_list);
 585
 586         thermal_zone_set_trips(tz);
 587
 588         list_sort(NULL, &way_up_list, thermal_trip_notify_cmp);
 589         list_for_each_entry(td, &way_up_list, notify_list_node)
 590                 thermal_trip_crossed(tz, &td->trip, governor, true);
 591
 592         list_sort(NULL, &way_down_list, thermal_trip_notify_cmp);
 593         list_for_each_entry_reverse(td, &way_down_list, notify_list_node)
 594                 thermal_trip_crossed(tz, &td->trip, governor, false);
 595
 596         if (governor->manage)
 597                 governor->manage(tz);
 598
 599         thermal_debug_update_trip_stats(tz);
 600
 601 monitor:
 602         monitor_thermal_zone(tz);
 603 }
 604
 605 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 606                                         enum thermal_device_mode mode)
 607 {
 608         int ret;
 609
 610         mutex_lock(&tz->lock);
 611
 612         /* do nothing if mode isn't changing */
 613         if (mode == tz->mode) {
 614                 mutex_unlock(&tz->lock);
 615
 616                 return 0;
 617         }
 618
 619         ret = __thermal_zone_device_set_mode(tz, mode);
 620         if (ret) {
 621                 mutex_unlock(&tz->lock);
 622
 623                 return ret;
 624         }
 625
 626         __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 627
 628         mutex_unlock(&tz->lock);
 629
 630         if (mode == THERMAL_DEVICE_ENABLED)
 631                 thermal_notify_tz_enable(tz);
 632         else
 633                 thermal_notify_tz_disable(tz);
 634
 635         return 0;
 636 }
 637
 638 int thermal_zone_device_enable(struct thermal_zone_device *tz)
 639 {
 640         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
 641 }
 642 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
 643
 644 int thermal_zone_device_disable(struct thermal_zone_device *tz)
 645 {
 646         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 647 }
 648 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 649
 650 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
 651 {
 652         lockdep_assert_held(&tz->lock);
 653
 654         return tz->mode == THERMAL_DEVICE_ENABLED;
 655 }
 656
 657 static bool thermal_zone_is_present(struct thermal_zone_device *tz)
 658 {
 659         return !list_empty(&tz->node);
 660 }
 661
 662 void thermal_zone_device_update(struct thermal_zone_device *tz,
 663                                 enum thermal_notify_event event)
 664 {
 665         mutex_lock(&tz->lock);
 666         if (thermal_zone_is_present(tz))
 667                 __thermal_zone_device_update(tz, event);
 668         mutex_unlock(&tz->lock);
 669 }
 670 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 671
 672 void thermal_zone_trip_down(struct thermal_zone_device *tz,
 673                             const struct thermal_trip *trip)
 674 {
 675         thermal_trip_crossed(tz, trip, thermal_get_tz_governor(tz), false);
 676 }
 677
 678 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 679                               void *data)
 680 {
 681         struct thermal_governor *gov;
 682         int ret = 0;
 683
 684         mutex_lock(&thermal_governor_lock);
 685         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 686                 ret = cb(gov, data);
 687                 if (ret)
 688                         break;
 689         }
 690         mutex_unlock(&thermal_governor_lock);
 691
 692         return ret;
 693 }
 694
 695 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 696                                               void *), void *data)
 697 {
 698         struct thermal_cooling_device *cdev;
 699         int ret = 0;
 700
 701         mutex_lock(&thermal_list_lock);
 702         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 703                 ret = cb(cdev, data);
 704                 if (ret)
 705                         break;
 706         }
 707         mutex_unlock(&thermal_list_lock);
 708
 709         return ret;
 710 }
 711
 712 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 713                           void *data)
 714 {
 715         struct thermal_zone_device *tz;
 716         int ret = 0;
 717
 718         mutex_lock(&thermal_list_lock);
 719         list_for_each_entry(tz, &thermal_tz_list, node) {
 720                 ret = cb(tz, data);
 721                 if (ret)
 722                         break;
 723         }
 724         mutex_unlock(&thermal_list_lock);
 725
 726         return ret;
 727 }
 728
 729 struct thermal_zone_device *thermal_zone_get_by_id(int id)
 730 {
 731         struct thermal_zone_device *tz, *match = NULL;
 732
 733         mutex_lock(&thermal_list_lock);
 734         list_for_each_entry(tz, &thermal_tz_list, node) {
 735                 if (tz->id == id) {
 736                         match = tz;
 737                         break;
 738                 }
 739         }
 740         mutex_unlock(&thermal_list_lock);
 741
 742         return match;
 743 }
 744
 745 /*
 746  * Device management section: cooling devices, zones devices, and binding
 747  *
 748  * Set of functions provided by the thermal core for:
 749  * - cooling devices lifecycle: registration, unregistration,
 750  *                              binding, and unbinding.
 751  * - thermal zone devices lifecycle: registration, unregistration,
 752  *                                   binding, and unbinding.
 753  */
 754
 755 /**
 756  * thermal_bind_cdev_to_trip - bind a cooling device to a thermal zone
 757  * @tz:         pointer to struct thermal_zone_device
 758  * @trip:       trip point the cooling devices is associated with in this zone.
 759  * @cdev:       pointer to struct thermal_cooling_device
 760  * @upper:      the Maximum cooling state for this trip point.
 761  *              THERMAL_NO_LIMIT means no upper limit,
 762  *              and the cooling device can be in max_state.
 763  * @lower:      the Minimum cooling state can be used for this trip point.
 764  *              THERMAL_NO_LIMIT means no lower limit,
 765  *              and the cooling device can be in cooling state 0.
 766  * @weight:     The weight of the cooling device to be bound to the
 767  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 768  *              default value
 769  *
 770  * This interface function bind a thermal cooling device to the certain trip
 771  * point of a thermal zone device.
 772  * This function is usually called in the thermal zone device .bind callback.
 773  *
 774  * Return: 0 on success, the proper error value otherwise.
 775  */
 776 int thermal_bind_cdev_to_trip(struct thermal_zone_device *tz,
 777                                      const struct thermal_trip *trip,
 778                                      struct thermal_cooling_device *cdev,
 779                                      unsigned long upper, unsigned long lower,
 780                                      unsigned int weight)
 781 {
 782         struct thermal_instance *dev;
 783         struct thermal_instance *pos;
 784         struct thermal_zone_device *pos1;
 785         struct thermal_cooling_device *pos2;
 786         bool upper_no_limit;
 787         int result;
 788
 789         list_for_each_entry(pos1, &thermal_tz_list, node) {
 790                 if (pos1 == tz)
 791                         break;
 792         }
 793         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 794                 if (pos2 == cdev)
 795                         break;
 796         }
 797
 798         if (tz != pos1 || cdev != pos2)
 799                 return -EINVAL;
 800
 801         /* lower default 0, upper default max_state */
 802         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 803
 804         if (upper == THERMAL_NO_LIMIT) {
 805                 upper = cdev->max_state;
 806                 upper_no_limit = true;
 807         } else {
 808                 upper_no_limit = false;
 809         }
 810
 811         if (lower > upper || upper > cdev->max_state)
 812                 return -EINVAL;
 813
 814         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 815         if (!dev)
 816                 return -ENOMEM;
 817         dev->tz = tz;
 818         dev->cdev = cdev;
 819         dev->trip = trip;
 820         dev->upper = upper;
 821         dev->upper_no_limit = upper_no_limit;
 822         dev->lower = lower;
 823         dev->target = THERMAL_NO_TARGET;
 824         dev->weight = weight;
 825
 826         result = ida_alloc(&tz->ida, GFP_KERNEL);
 827         if (result < 0)
 828                 goto free_mem;
 829
 830         dev->id = result;
 831         sprintf(dev->name, "cdev%d", dev->id);
 832         result =
 833             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 834         if (result)
 835                 goto release_ida;
 836
 837         snprintf(dev->attr_name, sizeof(dev->attr_name), "cdev%d_trip_point",
 838                  dev->id);
 839         sysfs_attr_init(&dev->attr.attr);
 840         dev->attr.attr.name = dev->attr_name;
 841         dev->attr.attr.mode = 0444;
 842         dev->attr.show = trip_point_show;
 843         result = device_create_file(&tz->device, &dev->attr);
 844         if (result)
 845                 goto remove_symbol_link;
 846
 847         snprintf(dev->weight_attr_name, sizeof(dev->weight_attr_name),
 848                  "cdev%d_weight", dev->id);
 849         sysfs_attr_init(&dev->weight_attr.attr);
 850         dev->weight_attr.attr.name = dev->weight_attr_name;
 851         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 852         dev->weight_attr.show = weight_show;
 853         dev->weight_attr.store = weight_store;
 854         result = device_create_file(&tz->device, &dev->weight_attr);
 855         if (result)
 856                 goto remove_trip_file;
 857
 858         mutex_lock(&tz->lock);
 859         mutex_lock(&cdev->lock);
 860         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 861                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 862                         result = -EEXIST;
 863                         break;
 864                 }
 865         if (!result) {
 866                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 867                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 868                 atomic_set(&tz->need_update, 1);
 869
 870                 thermal_governor_update_tz(tz, THERMAL_TZ_BIND_CDEV);
 871         }
 872         mutex_unlock(&cdev->lock);
 873         mutex_unlock(&tz->lock);
 874
 875         if (!result)
 876                 return 0;
 877
 878         device_remove_file(&tz->device, &dev->weight_attr);
 879 remove_trip_file:
 880         device_remove_file(&tz->device, &dev->attr);
 881 remove_symbol_link:
 882         sysfs_remove_link(&tz->device.kobj, dev->name);
 883 release_ida:
 884         ida_free(&tz->ida, dev->id);
 885 free_mem:
 886         kfree(dev);
 887         return result;
 888 }
 889 EXPORT_SYMBOL_GPL(thermal_bind_cdev_to_trip);
 890
 891 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 892                                      int trip_index,
 893                                      struct thermal_cooling_device *cdev,
 894                                      unsigned long upper, unsigned long lower,
 895                                      unsigned int weight)
 896 {
 897         if (trip_index < 0 || trip_index >= tz->num_trips)
 898                 return -EINVAL;
 899
 900         return thermal_bind_cdev_to_trip(tz, &tz->trips[trip_index].trip, cdev,
 901                                          upper, lower, weight);
 902 }
 903 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 904
 905 /**
 906  * thermal_unbind_cdev_from_trip - unbind a cooling device from a thermal zone.
 907  * @tz:         pointer to a struct thermal_zone_device.
 908  * @trip:       trip point the cooling devices is associated with in this zone.
 909  * @cdev:       pointer to a struct thermal_cooling_device.
 910  *
 911  * This interface function unbind a thermal cooling device from the certain
 912  * trip point of a thermal zone device.
 913  * This function is usually called in the thermal zone device .unbind callback.
 914  *
 915  * Return: 0 on success, the proper error value otherwise.
 916  */
 917 int thermal_unbind_cdev_from_trip(struct thermal_zone_device *tz,
 918                                   const struct thermal_trip *trip,
 919                                   struct thermal_cooling_device *cdev)
 920 {
 921         struct thermal_instance *pos, *next;
 922
 923         mutex_lock(&tz->lock);
 924         mutex_lock(&cdev->lock);
 925         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 926                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 927                         list_del(&pos->tz_node);
 928                         list_del(&pos->cdev_node);
 929
 930                         thermal_governor_update_tz(tz, THERMAL_TZ_UNBIND_CDEV);
 931
 932                         mutex_unlock(&cdev->lock);
 933                         mutex_unlock(&tz->lock);
 934                         goto unbind;
 935                 }
 936         }
 937         mutex_unlock(&cdev->lock);
 938         mutex_unlock(&tz->lock);
 939
 940         return -ENODEV;
 941
 942 unbind:
 943         device_remove_file(&tz->device, &pos->weight_attr);
 944         device_remove_file(&tz->device, &pos->attr);
 945         sysfs_remove_link(&tz->device.kobj, pos->name);
 946         ida_free(&tz->ida, pos->id);
 947         kfree(pos);
 948         return 0;
 949 }
 950 EXPORT_SYMBOL_GPL(thermal_unbind_cdev_from_trip);
 951
 952 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 953                                        int trip_index,
 954                                        struct thermal_cooling_device *cdev)
 955 {
 956         if (trip_index < 0 || trip_index >= tz->num_trips)
 957                 return -EINVAL;
 958
 959         return thermal_unbind_cdev_from_trip(tz, &tz->trips[trip_index].trip, cdev);
 960 }
 961 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 962
 963 static void thermal_release(struct device *dev)
 964 {
 965         struct thermal_zone_device *tz;
 966         struct thermal_cooling_device *cdev;
 967
 968         if (!strncmp(dev_name(dev), "thermal_zone",
 969                      sizeof("thermal_zone") - 1)) {
 970                 tz = to_thermal_zone(dev);
 971                 thermal_zone_destroy_device_groups(tz);
 972                 mutex_destroy(&tz->lock);
 973                 complete(&tz->removal);
 974         } else if (!strncmp(dev_name(dev), "cooling_device",
 975                             sizeof("cooling_device") - 1)) {
 976                 cdev = to_cooling_device(dev);
 977                 thermal_cooling_device_destroy_sysfs(cdev);
 978                 kfree_const(cdev->type);
 979                 ida_free(&thermal_cdev_ida, cdev->id);
 980                 kfree(cdev);
 981         }
 982 }
 983
 984 static struct class *thermal_class;
 985
 986 static inline
 987 void print_bind_err_msg(struct thermal_zone_device *tz,
 988                         struct thermal_cooling_device *cdev, int ret)
 989 {
 990         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
 991                 tz->type, cdev->type, ret);
 992 }
 993
 994 static void bind_cdev(struct thermal_cooling_device *cdev)
 995 {
 996         int ret;
 997         struct thermal_zone_device *pos = NULL;
 998
 999         list_for_each_entry(pos, &thermal_tz_list, node) {
1000                 if (pos->ops.bind) {
1001                         ret = pos->ops.bind(pos, cdev);
1002                         if (ret)
1003                                 print_bind_err_msg(pos, cdev, ret);
1004                 }
1005         }
1006 }
1007
1008 /**
1009  * __thermal_cooling_device_register() - register a new thermal cooling device
1010  * @np:         a pointer to a device tree node.
1011  * @type:       the thermal cooling device type.
1012  * @devdata:    device private data.
1013  * @ops:                standard thermal cooling devices callbacks.
1014  *
1015  * This interface function adds a new thermal cooling device (fan/processor/...)
1016  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1017  * to all the thermal zone devices registered at the same time.
1018  * It also gives the opportunity to link the cooling device to a device tree
1019  * node, so that it can be bound to a thermal zone created out of device tree.
1020  *
1021  * Return: a pointer to the created struct thermal_cooling_device or an
1022  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1023  */
1024 static struct thermal_cooling_device *
1025 __thermal_cooling_device_register(struct device_node *np,
1026                                   const char *type, void *devdata,
1027                                   const struct thermal_cooling_device_ops *ops)
1028 {
1029         struct thermal_cooling_device *cdev;
1030         struct thermal_zone_device *pos = NULL;
1031         unsigned long current_state;
1032         int id, ret;
1033
1034         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
1035             !ops->set_cur_state)
1036                 return ERR_PTR(-EINVAL);
1037
1038         if (!thermal_class)
1039                 return ERR_PTR(-ENODEV);
1040
1041         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
1042         if (!cdev)
1043                 return ERR_PTR(-ENOMEM);
1044
1045         ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
1046         if (ret < 0)
1047                 goto out_kfree_cdev;
1048         cdev->id = ret;
1049         id = ret;
1050
1051         cdev->type = kstrdup_const(type ? type : "", GFP_KERNEL);
1052         if (!cdev->type) {
1053                 ret = -ENOMEM;
1054                 goto out_ida_remove;
1055         }
1056
1057         mutex_init(&cdev->lock);
1058         INIT_LIST_HEAD(&cdev->thermal_instances);
1059         cdev->np = np;
1060         cdev->ops = ops;
1061         cdev->updated = false;
1062         cdev->device.class = thermal_class;
1063         cdev->devdata = devdata;
1064
1065         ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
1066         if (ret)
1067                 goto out_cdev_type;
1068
1069         /*
1070          * The cooling device's current state is only needed for debug
1071          * initialization below, so a failure to get it does not cause
1072          * the entire cooling device initialization to fail.  However,
1073          * the debug will not work for the device if its initial state
1074          * cannot be determined and drivers are responsible for ensuring
1075          * that this will not happen.
1076          */
1077         ret = cdev->ops->get_cur_state(cdev, &current_state);
1078         if (ret)
1079                 current_state = ULONG_MAX;
1080
1081         thermal_cooling_device_setup_sysfs(cdev);
1082
1083         ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
1084         if (ret)
1085                 goto out_cooling_dev;
1086
1087         ret = device_register(&cdev->device);
1088         if (ret) {
1089                 /* thermal_release() handles rest of the cleanup */
1090                 put_device(&cdev->device);
1091                 return ERR_PTR(ret);
1092         }
1093
1094         if (current_state <= cdev->max_state)
1095                 thermal_debug_cdev_add(cdev, current_state);
1096
1097         /* Add 'this' new cdev to the global cdev list */
1098         mutex_lock(&thermal_list_lock);
1099
1100         list_add(&cdev->node, &thermal_cdev_list);
1101
1102         /* Update binding information for 'this' new cdev */
1103         bind_cdev(cdev);
1104
1105         list_for_each_entry(pos, &thermal_tz_list, node)
1106                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
1107                         thermal_zone_device_update(pos,
1108                                                    THERMAL_EVENT_UNSPECIFIED);
1109
1110         mutex_unlock(&thermal_list_lock);
1111
1112         return cdev;
1113
1114 out_cooling_dev:
1115         thermal_cooling_device_destroy_sysfs(cdev);
1116 out_cdev_type:
1117         kfree_const(cdev->type);
1118 out_ida_remove:
1119         ida_free(&thermal_cdev_ida, id);
1120 out_kfree_cdev:
1121         kfree(cdev);
1122         return ERR_PTR(ret);
1123 }
1124
1125 /**
1126  * thermal_cooling_device_register() - register a new thermal cooling device
1127  * @type:       the thermal cooling device type.
1128  * @devdata:    device private data.
1129  * @ops:                standard thermal cooling devices callbacks.
1130  *
1131  * This interface function adds a new thermal cooling device (fan/processor/...)
1132  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1133  * to all the thermal zone devices registered at the same time.
1134  *
1135  * Return: a pointer to the created struct thermal_cooling_device or an
1136  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1137  */
1138 struct thermal_cooling_device *
1139 thermal_cooling_device_register(const char *type, void *devdata,
1140                                 const struct thermal_cooling_device_ops *ops)
1141 {
1142         return __thermal_cooling_device_register(NULL, type, devdata, ops);
1143 }
1144 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
1145
1146 /**
1147  * thermal_of_cooling_device_register() - register an OF thermal cooling device
1148  * @np:         a pointer to a device tree node.
1149  * @type:       the thermal cooling device type.
1150  * @devdata:    device private data.
1151  * @ops:                standard thermal cooling devices callbacks.
1152  *
1153  * This function will register a cooling device with device tree node reference.
1154  * This interface function adds a new thermal cooling device (fan/processor/...)
1155  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1156  * to all the thermal zone devices registered at the same time.
1157  *
1158  * Return: a pointer to the created struct thermal_cooling_device or an
1159  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1160  */
1161 struct thermal_cooling_device *
1162 thermal_of_cooling_device_register(struct device_node *np,
1163                                    const char *type, void *devdata,
1164                                    const struct thermal_cooling_device_ops *ops)
1165 {
1166         return __thermal_cooling_device_register(np, type, devdata, ops);
1167 }
1168 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
1169
1170 static void thermal_cooling_device_release(struct device *dev, void *res)
1171 {
1172         thermal_cooling_device_unregister(
1173                                 *(struct thermal_cooling_device **)res);
1174 }
1175
1176 /**
1177  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
1178  *                                             device
1179  * @dev:        a valid struct device pointer of a sensor device.
1180  * @np:         a pointer to a device tree node.
1181  * @type:       the thermal cooling device type.
1182  * @devdata:    device private data.
1183  * @ops:        standard thermal cooling devices callbacks.
1184  *
1185  * This function will register a cooling device with device tree node reference.
1186  * This interface function adds a new thermal cooling device (fan/processor/...)
1187  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
1188  * to all the thermal zone devices registered at the same time.
1189  *
1190  * Return: a pointer to the created struct thermal_cooling_device or an
1191  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1192  */
1193 struct thermal_cooling_device *
1194 devm_thermal_of_cooling_device_register(struct device *dev,
1195                                 struct device_node *np,
1196                                 const char *type, void *devdata,
1197                                 const struct thermal_cooling_device_ops *ops)
1198 {
1199         struct thermal_cooling_device **ptr, *tcd;
1200
1201         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1202                            GFP_KERNEL);
1203         if (!ptr)
1204                 return ERR_PTR(-ENOMEM);
1205
1206         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1207         if (IS_ERR(tcd)) {
1208                 devres_free(ptr);
1209                 return tcd;
1210         }
1211
1212         *ptr = tcd;
1213         devres_add(dev, ptr);
1214
1215         return tcd;
1216 }
1217 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1218
1219 static bool thermal_cooling_device_present(struct thermal_cooling_device *cdev)
1220 {
1221         struct thermal_cooling_device *pos = NULL;
1222
1223         list_for_each_entry(pos, &thermal_cdev_list, node) {
1224                 if (pos == cdev)
1225                         return true;
1226         }
1227
1228         return false;
1229 }
1230
1231 /**
1232  * thermal_cooling_device_update - Update a cooling device object
1233  * @cdev: Target cooling device.
1234  *
1235  * Update @cdev to reflect a change of the underlying hardware or platform.
1236  *
1237  * Must be called when the maximum cooling state of @cdev becomes invalid and so
1238  * its .get_max_state() callback needs to be run to produce the new maximum
1239  * cooling state value.
1240  */
1241 void thermal_cooling_device_update(struct thermal_cooling_device *cdev)
1242 {
1243         struct thermal_instance *ti;
1244         unsigned long state;
1245
1246         if (IS_ERR_OR_NULL(cdev))
1247                 return;
1248
1249         /*
1250          * Hold thermal_list_lock throughout the update to prevent the device
1251          * from going away while being updated.
1252          */
1253         mutex_lock(&thermal_list_lock);
1254
1255         if (!thermal_cooling_device_present(cdev))
1256                 goto unlock_list;
1257
1258         /*
1259          * Update under the cdev lock to prevent the state from being set beyond
1260          * the new limit concurrently.
1261          */
1262         mutex_lock(&cdev->lock);
1263
1264         if (cdev->ops->get_max_state(cdev, &cdev->max_state))
1265                 goto unlock;
1266
1267         thermal_cooling_device_stats_reinit(cdev);
1268
1269         list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) {
1270                 if (ti->upper == cdev->max_state)
1271                         continue;
1272
1273                 if (ti->upper < cdev->max_state) {
1274                         if (ti->upper_no_limit)
1275                                 ti->upper = cdev->max_state;
1276
1277                         continue;
1278                 }
1279
1280                 ti->upper = cdev->max_state;
1281                 if (ti->lower > ti->upper)
1282                         ti->lower = ti->upper;
1283
1284                 if (ti->target == THERMAL_NO_TARGET)
1285                         continue;
1286
1287                 if (ti->target > ti->upper)
1288                         ti->target = ti->upper;
1289         }
1290
1291         if (cdev->ops->get_cur_state(cdev, &state) || state > cdev->max_state)
1292                 goto unlock;
1293
1294         thermal_cooling_device_stats_update(cdev, state);
1295
1296 unlock:
1297         mutex_unlock(&cdev->lock);
1298
1299 unlock_list:
1300         mutex_unlock(&thermal_list_lock);
1301 }
1302 EXPORT_SYMBOL_GPL(thermal_cooling_device_update);
1303
1304 /**
1305  * thermal_cooling_device_unregister - removes a thermal cooling device
1306  * @cdev:       the thermal cooling device to remove.
1307  *
1308  * thermal_cooling_device_unregister() must be called when a registered
1309  * thermal cooling device is no longer needed.
1310  */
1311 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1312 {
1313         struct thermal_zone_device *tz;
1314
1315         if (!cdev)
1316                 return;
1317
1318         thermal_debug_cdev_remove(cdev);
1319
1320         mutex_lock(&thermal_list_lock);
1321
1322         if (!thermal_cooling_device_present(cdev)) {
1323                 mutex_unlock(&thermal_list_lock);
1324                 return;
1325         }
1326
1327         list_del(&cdev->node);
1328
1329         /* Unbind all thermal zones associated with 'this' cdev */
1330         list_for_each_entry(tz, &thermal_tz_list, node) {
1331                 if (tz->ops.unbind)
1332                         tz->ops.unbind(tz, cdev);
1333         }
1334
1335         mutex_unlock(&thermal_list_lock);
1336
1337         device_unregister(&cdev->device);
1338 }
1339 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1340
1341 static void bind_tz(struct thermal_zone_device *tz)
1342 {
1343         int ret;
1344         struct thermal_cooling_device *pos = NULL;
1345
1346         if (!tz->ops.bind)
1347                 return;
1348
1349         mutex_lock(&thermal_list_lock);
1350
1351         list_for_each_entry(pos, &thermal_cdev_list, node) {
1352                 ret = tz->ops.bind(tz, pos);
1353                 if (ret)
1354                         print_bind_err_msg(tz, pos, ret);
1355         }
1356
1357         mutex_unlock(&thermal_list_lock);
1358 }
1359
1360 static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
1361 {
1362         *delay_jiffies = msecs_to_jiffies(delay_ms);
1363         if (delay_ms > 1000)
1364                 *delay_jiffies = round_jiffies(*delay_jiffies);
1365 }
1366
1367 int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
1368 {
1369         const struct thermal_trip_desc *td;
1370         int ret = -EINVAL;
1371
1372         if (tz->ops.get_crit_temp)
1373                 return tz->ops.get_crit_temp(tz, temp);
1374
1375         mutex_lock(&tz->lock);
1376
1377         for_each_trip_desc(tz, td) {
1378                 const struct thermal_trip *trip = &td->trip;
1379
1380                 if (trip->type == THERMAL_TRIP_CRITICAL) {
1381                         *temp = trip->temperature;
1382                         ret = 0;
1383                         break;
1384                 }
1385         }
1386
1387         mutex_unlock(&tz->lock);
1388
1389         return ret;
1390 }
1391 EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
1392
1393 /**
1394  * thermal_zone_device_register_with_trips() - register a new thermal zone device
1395  * @type:       the thermal zone device type
1396  * @trips:      a pointer to an array of thermal trips
1397  * @num_trips:  the number of trip points the thermal zone support
1398  * @devdata:    private device data
1399  * @ops:        standard thermal zone device callbacks
1400  * @tzp:        thermal zone platform parameters
1401  * @passive_delay: number of milliseconds to wait between polls when
1402  *                 performing passive cooling
1403  * @polling_delay: number of milliseconds to wait between polls when checking
1404  *                 whether trip points have been crossed (0 for interrupt
1405  *                 driven systems)
1406  *
1407  * This interface function adds a new thermal zone device (sensor) to
1408  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1409  * thermal cooling devices registered at the same time.
1410  * thermal_zone_device_unregister() must be called when the device is no
1411  * longer needed. The passive cooling depends on the .get_trend() return value.
1412  *
1413  * Return: a pointer to the created struct thermal_zone_device or an
1414  * in case of error, an ERR_PTR. Caller must check return value with
1415  * IS_ERR*() helpers.
1416  */
1417 struct thermal_zone_device *
1418 thermal_zone_device_register_with_trips(const char *type,
1419                                         const struct thermal_trip *trips,
1420                                         int num_trips, void *devdata,
1421                                         const struct thermal_zone_device_ops *ops,
1422                                         const struct thermal_zone_params *tzp,
1423                                         unsigned int passive_delay,
1424                                         unsigned int polling_delay)
1425 {
1426         const struct thermal_trip *trip = trips;
1427         struct thermal_zone_device *tz;
1428         struct thermal_trip_desc *td;
1429         int id;
1430         int result;
1431         struct thermal_governor *governor;
1432
1433         if (!type || strlen(type) == 0) {
1434                 pr_err("No thermal zone type defined\n");
1435                 return ERR_PTR(-EINVAL);
1436         }
1437
1438         if (strlen(type) >= THERMAL_NAME_LENGTH) {
1439                 pr_err("Thermal zone name (%s) too long, should be under %d chars\n",
1440                        type, THERMAL_NAME_LENGTH);
1441                 return ERR_PTR(-EINVAL);
1442         }
1443
1444         if (num_trips < 0) {
1445                 pr_err("Incorrect number of thermal trips\n");
1446                 return ERR_PTR(-EINVAL);
1447         }
1448
1449         if (!ops || !ops->get_temp) {
1450                 pr_err("Thermal zone device ops not defined\n");
1451                 return ERR_PTR(-EINVAL);
1452         }
1453
1454         if (num_trips > 0 && !trips)
1455                 return ERR_PTR(-EINVAL);
1456
1457         if (polling_delay) {
1458                 if (passive_delay > polling_delay)
1459                         return ERR_PTR(-EINVAL);
1460
1461                 if (!passive_delay)
1462                         passive_delay = polling_delay;
1463         }
1464
1465         if (!thermal_class)
1466                 return ERR_PTR(-ENODEV);
1467
1468         tz = kzalloc(struct_size(tz, trips, num_trips), GFP_KERNEL);
1469         if (!tz)
1470                 return ERR_PTR(-ENOMEM);
1471
1472         if (tzp) {
1473                 tz->tzp = kmemdup(tzp, sizeof(*tzp), GFP_KERNEL);
1474                 if (!tz->tzp) {
1475                         result = -ENOMEM;
1476                         goto free_tz;
1477                 }
1478         }
1479
1480         INIT_LIST_HEAD(&tz->thermal_instances);
1481         INIT_LIST_HEAD(&tz->node);
1482         ida_init(&tz->ida);
1483         mutex_init(&tz->lock);
1484         init_completion(&tz->removal);
1485         init_completion(&tz->resume);
1486         id = ida_alloc(&thermal_tz_ida, GFP_KERNEL);
1487         if (id < 0) {
1488                 result = id;
1489                 goto free_tzp;
1490         }
1491
1492         tz->id = id;
1493         strscpy(tz->type, type, sizeof(tz->type));
1494
1495         tz->ops = *ops;
1496         if (!tz->ops.critical)
1497                 tz->ops.critical = thermal_zone_device_critical;
1498
1499         tz->device.class = thermal_class;
1500         tz->devdata = devdata;
1501         tz->num_trips = num_trips;
1502         for_each_trip_desc(tz, td) {
1503                 td->trip = *trip++;
1504                 /*
1505                  * Mark all thresholds as invalid to start with even though
1506                  * this only matters for the trips that start as invalid and
1507                  * become valid later.
1508                  */
1509                 td->threshold = INT_MAX;
1510         }
1511
1512         thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1513         thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1514         tz->recheck_delay_jiffies = THERMAL_RECHECK_DELAY;
1515
1516         /* sys I/F */
1517         /* Add nodes that are always present via .groups */
1518         result = thermal_zone_create_device_groups(tz);
1519         if (result)
1520                 goto remove_id;
1521
1522         /* A new thermal zone needs to be updated anyway. */
1523         atomic_set(&tz->need_update, 1);
1524
1525         result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1526         if (result) {
1527                 thermal_zone_destroy_device_groups(tz);
1528                 goto remove_id;
1529         }
1530         result = device_register(&tz->device);
1531         if (result)
1532                 goto release_device;
1533
1534         /* Update 'this' zone's governor information */
1535         mutex_lock(&thermal_governor_lock);
1536
1537         if (tz->tzp)
1538                 governor = __find_governor(tz->tzp->governor_name);
1539         else
1540                 governor = def_governor;
1541
1542         result = thermal_set_governor(tz, governor);
1543         if (result) {
1544                 mutex_unlock(&thermal_governor_lock);
1545                 goto unregister;
1546         }
1547
1548         mutex_unlock(&thermal_governor_lock);
1549
1550         if (!tz->tzp || !tz->tzp->no_hwmon) {
1551                 result = thermal_add_hwmon_sysfs(tz);
1552                 if (result)
1553                         goto unregister;
1554         }
1555
1556         mutex_lock(&thermal_list_lock);
1557         mutex_lock(&tz->lock);
1558         list_add_tail(&tz->node, &thermal_tz_list);
1559         mutex_unlock(&tz->lock);
1560         mutex_unlock(&thermal_list_lock);
1561
1562         /* Bind cooling devices for this zone */
1563         bind_tz(tz);
1564
1565         thermal_zone_device_init(tz);
1566         /* Update the new thermal zone and mark it as already updated. */
1567         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1568                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1569
1570         thermal_notify_tz_create(tz);
1571
1572         thermal_debug_tz_add(tz);
1573
1574         return tz;
1575
1576 unregister:
1577         device_del(&tz->device);
1578 release_device:
1579         put_device(&tz->device);
1580 remove_id:
1581         ida_free(&thermal_tz_ida, id);
1582 free_tzp:
1583         kfree(tz->tzp);
1584 free_tz:
1585         kfree(tz);
1586         return ERR_PTR(result);
1587 }
1588 EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);
1589
1590 struct thermal_zone_device *thermal_tripless_zone_device_register(
1591                                         const char *type,
1592                                         void *devdata,
1593                                         const struct thermal_zone_device_ops *ops,
1594                                         const struct thermal_zone_params *tzp)
1595 {
1596         return thermal_zone_device_register_with_trips(type, NULL, 0, devdata,
1597                                                        ops, tzp, 0, 0);
1598 }
1599 EXPORT_SYMBOL_GPL(thermal_tripless_zone_device_register);
1600
1601 void *thermal_zone_device_priv(struct thermal_zone_device *tzd)
1602 {
1603         return tzd->devdata;
1604 }
1605 EXPORT_SYMBOL_GPL(thermal_zone_device_priv);
1606
1607 const char *thermal_zone_device_type(struct thermal_zone_device *tzd)
1608 {
1609         return tzd->type;
1610 }
1611 EXPORT_SYMBOL_GPL(thermal_zone_device_type);
1612
1613 int thermal_zone_device_id(struct thermal_zone_device *tzd)
1614 {
1615         return tzd->id;
1616 }
1617 EXPORT_SYMBOL_GPL(thermal_zone_device_id);
1618
1619 struct device *thermal_zone_device(struct thermal_zone_device *tzd)
1620 {
1621         return &tzd->device;
1622 }
1623 EXPORT_SYMBOL_GPL(thermal_zone_device);
1624
1625 /**
1626  * thermal_zone_device_unregister - removes the registered thermal zone device
1627  * @tz: the thermal zone device to remove
1628  */
1629 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1630 {
1631         struct thermal_cooling_device *cdev;
1632         struct thermal_zone_device *pos = NULL;
1633
1634         if (!tz)
1635                 return;
1636
1637         thermal_debug_tz_remove(tz);
1638
1639         mutex_lock(&thermal_list_lock);
1640         list_for_each_entry(pos, &thermal_tz_list, node)
1641                 if (pos == tz)
1642                         break;
1643         if (pos != tz) {
1644                 /* thermal zone device not found */
1645                 mutex_unlock(&thermal_list_lock);
1646                 return;
1647         }
1648
1649         mutex_lock(&tz->lock);
1650         list_del(&tz->node);
1651         mutex_unlock(&tz->lock);
1652
1653         /* Unbind all cdevs associated with 'this' thermal zone */
1654         list_for_each_entry(cdev, &thermal_cdev_list, node)
1655                 if (tz->ops.unbind)
1656                         tz->ops.unbind(tz, cdev);
1657
1658         mutex_unlock(&thermal_list_lock);
1659
1660         cancel_delayed_work_sync(&tz->poll_queue);
1661
1662         thermal_set_governor(tz, NULL);
1663
1664         thermal_remove_hwmon_sysfs(tz);
1665         ida_free(&thermal_tz_ida, tz->id);
1666         ida_destroy(&tz->ida);
1667
1668         device_del(&tz->device);
1669
1670         kfree(tz->tzp);
1671
1672         put_device(&tz->device);
1673
1674         thermal_notify_tz_delete(tz);
1675
1676         wait_for_completion(&tz->removal);
1677         kfree(tz);
1678 }
1679 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1680
1681 /**
1682  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1683  * @name: thermal zone name to fetch the temperature
1684  *
1685  * When only one zone is found with the passed name, returns a reference to it.
1686  *
1687  * Return: On success returns a reference to an unique thermal zone with
1688  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1689  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1690  */
1691 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1692 {
1693         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1694         unsigned int found = 0;
1695
1696         if (!name)
1697                 goto exit;
1698
1699         mutex_lock(&thermal_list_lock);
1700         list_for_each_entry(pos, &thermal_tz_list, node)
1701                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1702                         found++;
1703                         ref = pos;
1704                 }
1705         mutex_unlock(&thermal_list_lock);
1706
1707         /* nothing has been found, thus an error code for it */
1708         if (found == 0)
1709                 ref = ERR_PTR(-ENODEV);
1710         else if (found > 1)
1711         /* Success only when an unique zone is found */
1712                 ref = ERR_PTR(-EEXIST);
1713
1714 exit:
1715         return ref;
1716 }
1717 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1718
1719 static void thermal_zone_device_resume(struct work_struct *work)
1720 {
1721         struct thermal_zone_device *tz;
1722
1723         tz = container_of(work, struct thermal_zone_device, poll_queue.work);
1724
1725         mutex_lock(&tz->lock);
1726
1727         tz->suspended = false;
1728
1729         thermal_debug_tz_resume(tz);
1730         thermal_zone_device_init(tz);
1731         thermal_governor_update_tz(tz, THERMAL_TZ_RESUME);
1732         __thermal_zone_device_update(tz, THERMAL_TZ_RESUME);
1733
1734         complete(&tz->resume);
1735         tz->resuming = false;
1736
1737         mutex_unlock(&tz->lock);
1738 }
1739
1740 static int thermal_pm_notify(struct notifier_block *nb,
1741                              unsigned long mode, void *_unused)
1742 {
1743         struct thermal_zone_device *tz;
1744
1745         switch (mode) {
1746         case PM_HIBERNATION_PREPARE:
1747         case PM_RESTORE_PREPARE:
1748         case PM_SUSPEND_PREPARE:
1749                 mutex_lock(&thermal_list_lock);
1750
1751                 list_for_each_entry(tz, &thermal_tz_list, node) {
1752                         mutex_lock(&tz->lock);
1753
1754                         if (tz->resuming) {
1755                                 /*
1756                                  * thermal_zone_device_resume() queued up for
1757                                  * this zone has not acquired the lock yet, so
1758                                  * release it to let the function run and wait
1759                                  * util it has done the work.
1760                                  */
1761                                 mutex_unlock(&tz->lock);
1762
1763                                 wait_for_completion(&tz->resume);
1764
1765                                 mutex_lock(&tz->lock);
1766                         }
1767
1768                         tz->suspended = true;
1769
1770                         mutex_unlock(&tz->lock);
1771                 }
1772
1773                 mutex_unlock(&thermal_list_lock);
1774                 break;
1775         case PM_POST_HIBERNATION:
1776         case PM_POST_RESTORE:
1777         case PM_POST_SUSPEND:
1778                 mutex_lock(&thermal_list_lock);
1779
1780                 list_for_each_entry(tz, &thermal_tz_list, node) {
1781                         mutex_lock(&tz->lock);
1782
1783                         cancel_delayed_work(&tz->poll_queue);
1784
1785                         reinit_completion(&tz->resume);
1786                         tz->resuming = true;
1787
1788                         /*
1789                          * Replace the work function with the resume one, which
1790                          * will restore the original work function and schedule
1791                          * the polling work if needed.
1792                          */
1793                         INIT_DELAYED_WORK(&tz->poll_queue,
1794                                           thermal_zone_device_resume);
1795                         /* Queue up the work without a delay. */
1796                         mod_delayed_work(system_freezable_power_efficient_wq,
1797                                          &tz->poll_queue, 0);
1798
1799                         mutex_unlock(&tz->lock);
1800                 }
1801
1802                 mutex_unlock(&thermal_list_lock);
1803                 break;
1804         default:
1805                 break;
1806         }
1807         return 0;
1808 }
1809
1810 static struct notifier_block thermal_pm_nb = {
1811         .notifier_call = thermal_pm_notify,
1812         /*
1813          * Run at the lowest priority to avoid interference between the thermal
1814          * zone resume work items spawned by thermal_pm_notify() and the other
1815          * PM notifiers.
1816          */
1817         .priority = INT_MIN,
1818 };
1819
1820 static int __init thermal_init(void)
1821 {
1822         int result;
1823
1824         thermal_debug_init();
1825
1826         result = thermal_netlink_init();
1827         if (result)
1828                 goto error;
1829
1830         result = thermal_register_governors();
1831         if (result)
1832                 goto unregister_netlink;
1833
1834         thermal_class = kzalloc(sizeof(*thermal_class), GFP_KERNEL);
1835         if (!thermal_class) {
1836                 result = -ENOMEM;
1837                 goto unregister_governors;
1838         }
1839
1840         thermal_class->name = "thermal";
1841         thermal_class->dev_release = thermal_release;
1842
1843         result = class_register(thermal_class);
1844         if (result) {
1845                 kfree(thermal_class);
1846                 thermal_class = NULL;
1847                 goto unregister_governors;
1848         }
1849
1850         result = register_pm_notifier(&thermal_pm_nb);
1851         if (result)
1852                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1853                         result);
1854
1855         return 0;
1856
1857 unregister_governors:
1858         thermal_unregister_governors();
1859 unregister_netlink:
1860         thermal_netlink_exit();
1861 error:
1862         mutex_destroy(&thermal_list_lock);
1863         mutex_destroy(&thermal_governor_lock);
1864         return result;
1865 }
1866 postcore_initcall(thermal_init);