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 "thermal_trace.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
  40 static atomic_t in_suspend;
  41
  42 static struct thermal_governor *def_governor;
  43
  44 /*
  45  * Governor section: set of functions to handle thermal governors
  46  *
  47  * Functions to help in the life cycle of thermal governors within
  48  * the thermal core and by the thermal governor code.
  49  */
  50
  51 static struct thermal_governor *__find_governor(const char *name)
  52 {
  53         struct thermal_governor *pos;
  54
  55         if (!name || !name[0])
  56                 return def_governor;
  57
  58         list_for_each_entry(pos, &thermal_governor_list, governor_list)
  59                 if (!strncasecmp(name, pos->name, THERMAL_NAME_LENGTH))
  60                         return pos;
  61
  62         return NULL;
  63 }
  64
  65 /**
  66  * bind_previous_governor() - bind the previous governor of the thermal zone
  67  * @tz:         a valid pointer to a struct thermal_zone_device
  68  * @failed_gov_name:    the name of the governor that failed to register
  69  *
  70  * Register the previous governor of the thermal zone after a new
  71  * governor has failed to be bound.
  72  */
  73 static void bind_previous_governor(struct thermal_zone_device *tz,
  74                                    const char *failed_gov_name)
  75 {
  76         if (tz->governor && tz->governor->bind_to_tz) {
  77                 if (tz->governor->bind_to_tz(tz)) {
  78                         dev_err(&tz->device,
  79                                 "governor %s failed to bind and the previous one (%s) failed to bind again, thermal zone %s has no governor\n",
  80                                 failed_gov_name, tz->governor->name, tz->type);
  81                         tz->governor = NULL;
  82                 }
  83         }
  84 }
  85
  86 /**
  87  * thermal_set_governor() - Switch to another governor
  88  * @tz:         a valid pointer to a struct thermal_zone_device
  89  * @new_gov:    pointer to the new governor
  90  *
  91  * Change the governor of thermal zone @tz.
  92  *
  93  * Return: 0 on success, an error if the new governor's bind_to_tz() failed.
  94  */
  95 static int thermal_set_governor(struct thermal_zone_device *tz,
  96                                 struct thermal_governor *new_gov)
  97 {
  98         int ret = 0;
  99
 100         if (tz->governor && tz->governor->unbind_from_tz)
 101                 tz->governor->unbind_from_tz(tz);
 102
 103         if (new_gov && new_gov->bind_to_tz) {
 104                 ret = new_gov->bind_to_tz(tz);
 105                 if (ret) {
 106                         bind_previous_governor(tz, new_gov->name);
 107
 108                         return ret;
 109                 }
 110         }
 111
 112         tz->governor = new_gov;
 113
 114         return ret;
 115 }
 116
 117 int thermal_register_governor(struct thermal_governor *governor)
 118 {
 119         int err;
 120         const char *name;
 121         struct thermal_zone_device *pos;
 122
 123         if (!governor)
 124                 return -EINVAL;
 125
 126         mutex_lock(&thermal_governor_lock);
 127
 128         err = -EBUSY;
 129         if (!__find_governor(governor->name)) {
 130                 bool match_default;
 131
 132                 err = 0;
 133                 list_add(&governor->governor_list, &thermal_governor_list);
 134                 match_default = !strncmp(governor->name,
 135                                          DEFAULT_THERMAL_GOVERNOR,
 136                                          THERMAL_NAME_LENGTH);
 137
 138                 if (!def_governor && match_default)
 139                         def_governor = governor;
 140         }
 141
 142         mutex_lock(&thermal_list_lock);
 143
 144         list_for_each_entry(pos, &thermal_tz_list, node) {
 145                 /*
 146                  * only thermal zones with specified tz->tzp->governor_name
 147                  * may run with tz->govenor unset
 148                  */
 149                 if (pos->governor)
 150                         continue;
 151
 152                 name = pos->tzp->governor_name;
 153
 154                 if (!strncasecmp(name, governor->name, THERMAL_NAME_LENGTH)) {
 155                         int ret;
 156
 157                         ret = thermal_set_governor(pos, governor);
 158                         if (ret)
 159                                 dev_err(&pos->device,
 160                                         "Failed to set governor %s for thermal zone %s: %d\n",
 161                                         governor->name, pos->type, ret);
 162                 }
 163         }
 164
 165         mutex_unlock(&thermal_list_lock);
 166         mutex_unlock(&thermal_governor_lock);
 167
 168         return err;
 169 }
 170
 171 void thermal_unregister_governor(struct thermal_governor *governor)
 172 {
 173         struct thermal_zone_device *pos;
 174
 175         if (!governor)
 176                 return;
 177
 178         mutex_lock(&thermal_governor_lock);
 179
 180         if (!__find_governor(governor->name))
 181                 goto exit;
 182
 183         mutex_lock(&thermal_list_lock);
 184
 185         list_for_each_entry(pos, &thermal_tz_list, node) {
 186                 if (!strncasecmp(pos->governor->name, governor->name,
 187                                  THERMAL_NAME_LENGTH))
 188                         thermal_set_governor(pos, NULL);
 189         }
 190
 191         mutex_unlock(&thermal_list_lock);
 192         list_del(&governor->governor_list);
 193 exit:
 194         mutex_unlock(&thermal_governor_lock);
 195 }
 196
 197 int thermal_zone_device_set_policy(struct thermal_zone_device *tz,
 198                                    char *policy)
 199 {
 200         struct thermal_governor *gov;
 201         int ret = -EINVAL;
 202
 203         mutex_lock(&thermal_governor_lock);
 204         mutex_lock(&tz->lock);
 205
 206         if (!device_is_registered(&tz->device))
 207                 goto exit;
 208
 209         gov = __find_governor(strim(policy));
 210         if (!gov)
 211                 goto exit;
 212
 213         ret = thermal_set_governor(tz, gov);
 214
 215 exit:
 216         mutex_unlock(&tz->lock);
 217         mutex_unlock(&thermal_governor_lock);
 218
 219         thermal_notify_tz_gov_change(tz->id, policy);
 220
 221         return ret;
 222 }
 223
 224 int thermal_build_list_of_policies(char *buf)
 225 {
 226         struct thermal_governor *pos;
 227         ssize_t count = 0;
 228
 229         mutex_lock(&thermal_governor_lock);
 230
 231         list_for_each_entry(pos, &thermal_governor_list, governor_list) {
 232                 count += sysfs_emit_at(buf, count, "%s ", pos->name);
 233         }
 234         count += sysfs_emit_at(buf, count, "\n");
 235
 236         mutex_unlock(&thermal_governor_lock);
 237
 238         return count;
 239 }
 240
 241 static void __init thermal_unregister_governors(void)
 242 {
 243         struct thermal_governor **governor;
 244
 245         for_each_governor_table(governor)
 246                 thermal_unregister_governor(*governor);
 247 }
 248
 249 static int __init thermal_register_governors(void)
 250 {
 251         int ret = 0;
 252         struct thermal_governor **governor;
 253
 254         for_each_governor_table(governor) {
 255                 ret = thermal_register_governor(*governor);
 256                 if (ret) {
 257                         pr_err("Failed to register governor: '%s'",
 258                                (*governor)->name);
 259                         break;
 260                 }
 261
 262                 pr_info("Registered thermal governor '%s'",
 263                         (*governor)->name);
 264         }
 265
 266         if (ret) {
 267                 struct thermal_governor **gov;
 268
 269                 for_each_governor_table(gov) {
 270                         if (gov == governor)
 271                                 break;
 272                         thermal_unregister_governor(*gov);
 273                 }
 274         }
 275
 276         return ret;
 277 }
 278
 279 /*
 280  * Zone update section: main control loop applied to each zone while monitoring
 281  *
 282  * in polling mode. The monitoring is done using a workqueue.
 283  * Same update may be done on a zone by calling thermal_zone_device_update().
 284  *
 285  * An update means:
 286  * - Non-critical trips will invoke the governor responsible for that zone;
 287  * - Hot trips will produce a notification to userspace;
 288  * - Critical trip point will cause a system shutdown.
 289  */
 290 static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 291                                             unsigned long delay)
 292 {
 293         if (delay)
 294                 mod_delayed_work(system_freezable_power_efficient_wq,
 295                                  &tz->poll_queue, delay);
 296         else
 297                 cancel_delayed_work(&tz->poll_queue);
 298 }
 299
 300 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 301 {
 302         if (tz->mode != THERMAL_DEVICE_ENABLED)
 303                 thermal_zone_device_set_polling(tz, 0);
 304         else if (tz->passive)
 305                 thermal_zone_device_set_polling(tz, tz->passive_delay_jiffies);
 306         else if (tz->polling_delay_jiffies)
 307                 thermal_zone_device_set_polling(tz, tz->polling_delay_jiffies);
 308 }
 309
 310 static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
 311 {
 312         tz->governor ? tz->governor->throttle(tz, trip) :
 313                        def_governor->throttle(tz, trip);
 314 }
 315
 316 void thermal_zone_device_critical(struct thermal_zone_device *tz)
 317 {
 318         /*
 319          * poweroff_delay_ms must be a carefully profiled positive value.
 320          * Its a must for forced_emergency_poweroff_work to be scheduled.
 321          */
 322         int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
 323
 324         dev_emerg(&tz->device, "%s: critical temperature reached, "
 325                   "shutting down\n", tz->type);
 326
 327         hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
 328 }
 329 EXPORT_SYMBOL(thermal_zone_device_critical);
 330
 331 static void handle_critical_trips(struct thermal_zone_device *tz,
 332                                   int trip, int trip_temp, enum thermal_trip_type trip_type)
 333 {
 334         /* If we have not crossed the trip_temp, we do not care. */
 335         if (trip_temp <= 0 || tz->temperature < trip_temp)
 336                 return;
 337
 338         trace_thermal_zone_trip(tz, trip, trip_type);
 339
 340         if (trip_type == THERMAL_TRIP_HOT && tz->ops->hot)
 341                 tz->ops->hot(tz);
 342         else if (trip_type == THERMAL_TRIP_CRITICAL)
 343                 tz->ops->critical(tz);
 344 }
 345
 346 static void handle_thermal_trip(struct thermal_zone_device *tz, int trip_id)
 347 {
 348         struct thermal_trip trip;
 349
 350         /* Ignore disabled trip points */
 351         if (test_bit(trip_id, &tz->trips_disabled))
 352                 return;
 353
 354         __thermal_zone_get_trip(tz, trip_id, &trip);
 355
 356         if (trip.temperature == THERMAL_TEMP_INVALID)
 357                 return;
 358
 359         if (tz->last_temperature != THERMAL_TEMP_INVALID) {
 360                 if (tz->last_temperature < trip.temperature &&
 361                     tz->temperature >= trip.temperature)
 362                         thermal_notify_tz_trip_up(tz->id, trip_id,
 363                                                   tz->temperature);
 364                 if (tz->last_temperature >= trip.temperature &&
 365                     tz->temperature < (trip.temperature - trip.hysteresis))
 366                         thermal_notify_tz_trip_down(tz->id, trip_id,
 367                                                     tz->temperature);
 368         }
 369
 370         if (trip.type == THERMAL_TRIP_CRITICAL || trip.type == THERMAL_TRIP_HOT)
 371                 handle_critical_trips(tz, trip_id, trip.temperature, trip.type);
 372         else
 373                 handle_non_critical_trips(tz, trip_id);
 374 }
 375
 376 static void update_temperature(struct thermal_zone_device *tz)
 377 {
 378         int temp, ret;
 379
 380         ret = __thermal_zone_get_temp(tz, &temp);
 381         if (ret) {
 382                 if (ret != -EAGAIN)
 383                         dev_warn(&tz->device,
 384                                  "failed to read out thermal zone (%d)\n",
 385                                  ret);
 386                 return;
 387         }
 388
 389         tz->last_temperature = tz->temperature;
 390         tz->temperature = temp;
 391
 392         trace_thermal_temperature(tz);
 393
 394         thermal_genl_sampling_temp(tz->id, temp);
 395 }
 396
 397 static void thermal_zone_device_init(struct thermal_zone_device *tz)
 398 {
 399         struct thermal_instance *pos;
 400         tz->temperature = THERMAL_TEMP_INVALID;
 401         tz->prev_low_trip = -INT_MAX;
 402         tz->prev_high_trip = INT_MAX;
 403         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 404                 pos->initialized = false;
 405 }
 406
 407 void __thermal_zone_device_update(struct thermal_zone_device *tz,
 408                                   enum thermal_notify_event event)
 409 {
 410         int count;
 411
 412         if (atomic_read(&in_suspend))
 413                 return;
 414
 415         if (WARN_ONCE(!tz->ops->get_temp,
 416                       "'%s' must not be called without 'get_temp' ops set\n",
 417                       __func__))
 418                 return;
 419
 420         if (!thermal_zone_device_is_enabled(tz))
 421                 return;
 422
 423         update_temperature(tz);
 424
 425         __thermal_zone_set_trips(tz);
 426
 427         tz->notify_event = event;
 428
 429         for (count = 0; count < tz->num_trips; count++)
 430                 handle_thermal_trip(tz, count);
 431
 432         monitor_thermal_zone(tz);
 433 }
 434
 435 static int thermal_zone_device_set_mode(struct thermal_zone_device *tz,
 436                                         enum thermal_device_mode mode)
 437 {
 438         int ret = 0;
 439
 440         mutex_lock(&tz->lock);
 441
 442         /* do nothing if mode isn't changing */
 443         if (mode == tz->mode) {
 444                 mutex_unlock(&tz->lock);
 445
 446                 return ret;
 447         }
 448
 449         if (!device_is_registered(&tz->device)) {
 450                 mutex_unlock(&tz->lock);
 451
 452                 return -ENODEV;
 453         }
 454
 455         if (tz->ops->change_mode)
 456                 ret = tz->ops->change_mode(tz, mode);
 457
 458         if (!ret)
 459                 tz->mode = mode;
 460
 461         __thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 462
 463         mutex_unlock(&tz->lock);
 464
 465         if (mode == THERMAL_DEVICE_ENABLED)
 466                 thermal_notify_tz_enable(tz->id);
 467         else
 468                 thermal_notify_tz_disable(tz->id);
 469
 470         return ret;
 471 }
 472
 473 int thermal_zone_device_enable(struct thermal_zone_device *tz)
 474 {
 475         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_ENABLED);
 476 }
 477 EXPORT_SYMBOL_GPL(thermal_zone_device_enable);
 478
 479 int thermal_zone_device_disable(struct thermal_zone_device *tz)
 480 {
 481         return thermal_zone_device_set_mode(tz, THERMAL_DEVICE_DISABLED);
 482 }
 483 EXPORT_SYMBOL_GPL(thermal_zone_device_disable);
 484
 485 int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
 486 {
 487         lockdep_assert_held(&tz->lock);
 488
 489         return tz->mode == THERMAL_DEVICE_ENABLED;
 490 }
 491
 492 void thermal_zone_device_update(struct thermal_zone_device *tz,
 493                                 enum thermal_notify_event event)
 494 {
 495         mutex_lock(&tz->lock);
 496         if (device_is_registered(&tz->device))
 497                 __thermal_zone_device_update(tz, event);
 498         mutex_unlock(&tz->lock);
 499 }
 500 EXPORT_SYMBOL_GPL(thermal_zone_device_update);
 501
 502 /**
 503  * thermal_zone_device_exec - Run a callback under the zone lock.
 504  * @tz: Thermal zone.
 505  * @cb: Callback to run.
 506  * @data: Data to pass to the callback.
 507  */
 508 void thermal_zone_device_exec(struct thermal_zone_device *tz,
 509                               void (*cb)(struct thermal_zone_device *,
 510                                          unsigned long),
 511                               unsigned long data)
 512 {
 513         mutex_lock(&tz->lock);
 514
 515         cb(tz, data);
 516
 517         mutex_unlock(&tz->lock);
 518 }
 519 EXPORT_SYMBOL_GPL(thermal_zone_device_exec);
 520
 521 static void thermal_zone_device_check(struct work_struct *work)
 522 {
 523         struct thermal_zone_device *tz = container_of(work, struct
 524                                                       thermal_zone_device,
 525                                                       poll_queue.work);
 526         thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
 527 }
 528
 529 int for_each_thermal_governor(int (*cb)(struct thermal_governor *, void *),
 530                               void *data)
 531 {
 532         struct thermal_governor *gov;
 533         int ret = 0;
 534
 535         mutex_lock(&thermal_governor_lock);
 536         list_for_each_entry(gov, &thermal_governor_list, governor_list) {
 537                 ret = cb(gov, data);
 538                 if (ret)
 539                         break;
 540         }
 541         mutex_unlock(&thermal_governor_lock);
 542
 543         return ret;
 544 }
 545
 546 int for_each_thermal_cooling_device(int (*cb)(struct thermal_cooling_device *,
 547                                               void *), void *data)
 548 {
 549         struct thermal_cooling_device *cdev;
 550         int ret = 0;
 551
 552         mutex_lock(&thermal_list_lock);
 553         list_for_each_entry(cdev, &thermal_cdev_list, node) {
 554                 ret = cb(cdev, data);
 555                 if (ret)
 556                         break;
 557         }
 558         mutex_unlock(&thermal_list_lock);
 559
 560         return ret;
 561 }
 562
 563 int for_each_thermal_zone(int (*cb)(struct thermal_zone_device *, void *),
 564                           void *data)
 565 {
 566         struct thermal_zone_device *tz;
 567         int ret = 0;
 568
 569         mutex_lock(&thermal_list_lock);
 570         list_for_each_entry(tz, &thermal_tz_list, node) {
 571                 ret = cb(tz, data);
 572                 if (ret)
 573                         break;
 574         }
 575         mutex_unlock(&thermal_list_lock);
 576
 577         return ret;
 578 }
 579
 580 struct thermal_zone_device *thermal_zone_get_by_id(int id)
 581 {
 582         struct thermal_zone_device *tz, *match = NULL;
 583
 584         mutex_lock(&thermal_list_lock);
 585         list_for_each_entry(tz, &thermal_tz_list, node) {
 586                 if (tz->id == id) {
 587                         match = tz;
 588                         break;
 589                 }
 590         }
 591         mutex_unlock(&thermal_list_lock);
 592
 593         return match;
 594 }
 595
 596 /*
 597  * Device management section: cooling devices, zones devices, and binding
 598  *
 599  * Set of functions provided by the thermal core for:
 600  * - cooling devices lifecycle: registration, unregistration,
 601  *                              binding, and unbinding.
 602  * - thermal zone devices lifecycle: registration, unregistration,
 603  *                                   binding, and unbinding.
 604  */
 605
 606 /**
 607  * thermal_zone_bind_cooling_device() - bind a cooling device to a thermal zone
 608  * @tz:         pointer to struct thermal_zone_device
 609  * @trip:       indicates which trip point the cooling devices is
 610  *              associated with in this thermal zone.
 611  * @cdev:       pointer to struct thermal_cooling_device
 612  * @upper:      the Maximum cooling state for this trip point.
 613  *              THERMAL_NO_LIMIT means no upper limit,
 614  *              and the cooling device can be in max_state.
 615  * @lower:      the Minimum cooling state can be used for this trip point.
 616  *              THERMAL_NO_LIMIT means no lower limit,
 617  *              and the cooling device can be in cooling state 0.
 618  * @weight:     The weight of the cooling device to be bound to the
 619  *              thermal zone. Use THERMAL_WEIGHT_DEFAULT for the
 620  *              default value
 621  *
 622  * This interface function bind a thermal cooling device to the certain trip
 623  * point of a thermal zone device.
 624  * This function is usually called in the thermal zone device .bind callback.
 625  *
 626  * Return: 0 on success, the proper error value otherwise.
 627  */
 628 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 629                                      int trip,
 630                                      struct thermal_cooling_device *cdev,
 631                                      unsigned long upper, unsigned long lower,
 632                                      unsigned int weight)
 633 {
 634         struct thermal_instance *dev;
 635         struct thermal_instance *pos;
 636         struct thermal_zone_device *pos1;
 637         struct thermal_cooling_device *pos2;
 638         bool upper_no_limit;
 639         int result;
 640
 641         if (trip >= tz->num_trips || trip < 0)
 642                 return -EINVAL;
 643
 644         list_for_each_entry(pos1, &thermal_tz_list, node) {
 645                 if (pos1 == tz)
 646                         break;
 647         }
 648         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 649                 if (pos2 == cdev)
 650                         break;
 651         }
 652
 653         if (tz != pos1 || cdev != pos2)
 654                 return -EINVAL;
 655
 656         /* lower default 0, upper default max_state */
 657         lower = lower == THERMAL_NO_LIMIT ? 0 : lower;
 658
 659         if (upper == THERMAL_NO_LIMIT) {
 660                 upper = cdev->max_state;
 661                 upper_no_limit = true;
 662         } else {
 663                 upper_no_limit = false;
 664         }
 665
 666         if (lower > upper || upper > cdev->max_state)
 667                 return -EINVAL;
 668
 669         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 670         if (!dev)
 671                 return -ENOMEM;
 672         dev->tz = tz;
 673         dev->cdev = cdev;
 674         dev->trip = trip;
 675         dev->upper = upper;
 676         dev->upper_no_limit = upper_no_limit;
 677         dev->lower = lower;
 678         dev->target = THERMAL_NO_TARGET;
 679         dev->weight = weight;
 680
 681         result = ida_alloc(&tz->ida, GFP_KERNEL);
 682         if (result < 0)
 683                 goto free_mem;
 684
 685         dev->id = result;
 686         sprintf(dev->name, "cdev%d", dev->id);
 687         result =
 688             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 689         if (result)
 690                 goto release_ida;
 691
 692         snprintf(dev->attr_name, sizeof(dev->attr_name), "cdev%d_trip_point",
 693                  dev->id);
 694         sysfs_attr_init(&dev->attr.attr);
 695         dev->attr.attr.name = dev->attr_name;
 696         dev->attr.attr.mode = 0444;
 697         dev->attr.show = trip_point_show;
 698         result = device_create_file(&tz->device, &dev->attr);
 699         if (result)
 700                 goto remove_symbol_link;
 701
 702         snprintf(dev->weight_attr_name, sizeof(dev->weight_attr_name),
 703                  "cdev%d_weight", dev->id);
 704         sysfs_attr_init(&dev->weight_attr.attr);
 705         dev->weight_attr.attr.name = dev->weight_attr_name;
 706         dev->weight_attr.attr.mode = S_IWUSR | S_IRUGO;
 707         dev->weight_attr.show = weight_show;
 708         dev->weight_attr.store = weight_store;
 709         result = device_create_file(&tz->device, &dev->weight_attr);
 710         if (result)
 711                 goto remove_trip_file;
 712
 713         mutex_lock(&tz->lock);
 714         mutex_lock(&cdev->lock);
 715         list_for_each_entry(pos, &tz->thermal_instances, tz_node)
 716                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 717                         result = -EEXIST;
 718                         break;
 719                 }
 720         if (!result) {
 721                 list_add_tail(&dev->tz_node, &tz->thermal_instances);
 722                 list_add_tail(&dev->cdev_node, &cdev->thermal_instances);
 723                 atomic_set(&tz->need_update, 1);
 724         }
 725         mutex_unlock(&cdev->lock);
 726         mutex_unlock(&tz->lock);
 727
 728         if (!result)
 729                 return 0;
 730
 731         device_remove_file(&tz->device, &dev->weight_attr);
 732 remove_trip_file:
 733         device_remove_file(&tz->device, &dev->attr);
 734 remove_symbol_link:
 735         sysfs_remove_link(&tz->device.kobj, dev->name);
 736 release_ida:
 737         ida_free(&tz->ida, dev->id);
 738 free_mem:
 739         kfree(dev);
 740         return result;
 741 }
 742 EXPORT_SYMBOL_GPL(thermal_zone_bind_cooling_device);
 743
 744 /**
 745  * thermal_zone_unbind_cooling_device() - unbind a cooling device from a
 746  *                                        thermal zone.
 747  * @tz:         pointer to a struct thermal_zone_device.
 748  * @trip:       indicates which trip point the cooling devices is
 749  *              associated with in this thermal zone.
 750  * @cdev:       pointer to a struct thermal_cooling_device.
 751  *
 752  * This interface function unbind a thermal cooling device from the certain
 753  * trip point of a thermal zone device.
 754  * This function is usually called in the thermal zone device .unbind callback.
 755  *
 756  * Return: 0 on success, the proper error value otherwise.
 757  */
 758 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 759                                        int trip,
 760                                        struct thermal_cooling_device *cdev)
 761 {
 762         struct thermal_instance *pos, *next;
 763
 764         mutex_lock(&tz->lock);
 765         mutex_lock(&cdev->lock);
 766         list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) {
 767                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 768                         list_del(&pos->tz_node);
 769                         list_del(&pos->cdev_node);
 770                         mutex_unlock(&cdev->lock);
 771                         mutex_unlock(&tz->lock);
 772                         goto unbind;
 773                 }
 774         }
 775         mutex_unlock(&cdev->lock);
 776         mutex_unlock(&tz->lock);
 777
 778         return -ENODEV;
 779
 780 unbind:
 781         device_remove_file(&tz->device, &pos->weight_attr);
 782         device_remove_file(&tz->device, &pos->attr);
 783         sysfs_remove_link(&tz->device.kobj, pos->name);
 784         ida_free(&tz->ida, pos->id);
 785         kfree(pos);
 786         return 0;
 787 }
 788 EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device);
 789
 790 static void thermal_release(struct device *dev)
 791 {
 792         struct thermal_zone_device *tz;
 793         struct thermal_cooling_device *cdev;
 794
 795         if (!strncmp(dev_name(dev), "thermal_zone",
 796                      sizeof("thermal_zone") - 1)) {
 797                 tz = to_thermal_zone(dev);
 798                 thermal_zone_destroy_device_groups(tz);
 799                 mutex_destroy(&tz->lock);
 800                 kfree(tz);
 801         } else if (!strncmp(dev_name(dev), "cooling_device",
 802                             sizeof("cooling_device") - 1)) {
 803                 cdev = to_cooling_device(dev);
 804                 thermal_cooling_device_destroy_sysfs(cdev);
 805                 kfree(cdev->type);
 806                 ida_free(&thermal_cdev_ida, cdev->id);
 807                 kfree(cdev);
 808         }
 809 }
 810
 811 static struct class *thermal_class;
 812
 813 static inline
 814 void print_bind_err_msg(struct thermal_zone_device *tz,
 815                         struct thermal_cooling_device *cdev, int ret)
 816 {
 817         dev_err(&tz->device, "binding zone %s with cdev %s failed:%d\n",
 818                 tz->type, cdev->type, ret);
 819 }
 820
 821 static void bind_cdev(struct thermal_cooling_device *cdev)
 822 {
 823         int ret;
 824         struct thermal_zone_device *pos = NULL;
 825
 826         list_for_each_entry(pos, &thermal_tz_list, node) {
 827                 if (pos->ops->bind) {
 828                         ret = pos->ops->bind(pos, cdev);
 829                         if (ret)
 830                                 print_bind_err_msg(pos, cdev, ret);
 831                 }
 832         }
 833 }
 834
 835 /**
 836  * __thermal_cooling_device_register() - register a new thermal cooling device
 837  * @np:         a pointer to a device tree node.
 838  * @type:       the thermal cooling device type.
 839  * @devdata:    device private data.
 840  * @ops:                standard thermal cooling devices callbacks.
 841  *
 842  * This interface function adds a new thermal cooling device (fan/processor/...)
 843  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 844  * to all the thermal zone devices registered at the same time.
 845  * It also gives the opportunity to link the cooling device to a device tree
 846  * node, so that it can be bound to a thermal zone created out of device tree.
 847  *
 848  * Return: a pointer to the created struct thermal_cooling_device or an
 849  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 850  */
 851 static struct thermal_cooling_device *
 852 __thermal_cooling_device_register(struct device_node *np,
 853                                   const char *type, void *devdata,
 854                                   const struct thermal_cooling_device_ops *ops)
 855 {
 856         struct thermal_cooling_device *cdev;
 857         struct thermal_zone_device *pos = NULL;
 858         int id, ret;
 859
 860         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
 861             !ops->set_cur_state)
 862                 return ERR_PTR(-EINVAL);
 863
 864         if (!thermal_class)
 865                 return ERR_PTR(-ENODEV);
 866
 867         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 868         if (!cdev)
 869                 return ERR_PTR(-ENOMEM);
 870
 871         ret = ida_alloc(&thermal_cdev_ida, GFP_KERNEL);
 872         if (ret < 0)
 873                 goto out_kfree_cdev;
 874         cdev->id = ret;
 875         id = ret;
 876
 877         cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
 878         if (!cdev->type) {
 879                 ret = -ENOMEM;
 880                 goto out_ida_remove;
 881         }
 882
 883         mutex_init(&cdev->lock);
 884         INIT_LIST_HEAD(&cdev->thermal_instances);
 885         cdev->np = np;
 886         cdev->ops = ops;
 887         cdev->updated = false;
 888         cdev->device.class = thermal_class;
 889         cdev->devdata = devdata;
 890
 891         ret = cdev->ops->get_max_state(cdev, &cdev->max_state);
 892         if (ret)
 893                 goto out_cdev_type;
 894
 895         thermal_cooling_device_setup_sysfs(cdev);
 896
 897         ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id);
 898         if (ret)
 899                 goto out_cooling_dev;
 900
 901         ret = device_register(&cdev->device);
 902         if (ret) {
 903                 /* thermal_release() handles rest of the cleanup */
 904                 put_device(&cdev->device);
 905                 return ERR_PTR(ret);
 906         }
 907
 908         /* Add 'this' new cdev to the global cdev list */
 909         mutex_lock(&thermal_list_lock);
 910
 911         list_add(&cdev->node, &thermal_cdev_list);
 912
 913         /* Update binding information for 'this' new cdev */
 914         bind_cdev(cdev);
 915
 916         list_for_each_entry(pos, &thermal_tz_list, node)
 917                 if (atomic_cmpxchg(&pos->need_update, 1, 0))
 918                         thermal_zone_device_update(pos,
 919                                                    THERMAL_EVENT_UNSPECIFIED);
 920
 921         mutex_unlock(&thermal_list_lock);
 922
 923         return cdev;
 924
 925 out_cooling_dev:
 926         thermal_cooling_device_destroy_sysfs(cdev);
 927 out_cdev_type:
 928         kfree(cdev->type);
 929 out_ida_remove:
 930         ida_free(&thermal_cdev_ida, id);
 931 out_kfree_cdev:
 932         kfree(cdev);
 933         return ERR_PTR(ret);
 934 }
 935
 936 /**
 937  * thermal_cooling_device_register() - register a new thermal cooling device
 938  * @type:       the thermal cooling device type.
 939  * @devdata:    device private data.
 940  * @ops:                standard thermal cooling devices callbacks.
 941  *
 942  * This interface function adds a new thermal cooling device (fan/processor/...)
 943  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 944  * to all the thermal zone devices registered at the same time.
 945  *
 946  * Return: a pointer to the created struct thermal_cooling_device or an
 947  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 948  */
 949 struct thermal_cooling_device *
 950 thermal_cooling_device_register(const char *type, void *devdata,
 951                                 const struct thermal_cooling_device_ops *ops)
 952 {
 953         return __thermal_cooling_device_register(NULL, type, devdata, ops);
 954 }
 955 EXPORT_SYMBOL_GPL(thermal_cooling_device_register);
 956
 957 /**
 958  * thermal_of_cooling_device_register() - register an OF thermal cooling device
 959  * @np:         a pointer to a device tree node.
 960  * @type:       the thermal cooling device type.
 961  * @devdata:    device private data.
 962  * @ops:                standard thermal cooling devices callbacks.
 963  *
 964  * This function will register a cooling device with device tree node reference.
 965  * This interface function adds a new thermal cooling device (fan/processor/...)
 966  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 967  * to all the thermal zone devices registered at the same time.
 968  *
 969  * Return: a pointer to the created struct thermal_cooling_device or an
 970  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
 971  */
 972 struct thermal_cooling_device *
 973 thermal_of_cooling_device_register(struct device_node *np,
 974                                    const char *type, void *devdata,
 975                                    const struct thermal_cooling_device_ops *ops)
 976 {
 977         return __thermal_cooling_device_register(np, type, devdata, ops);
 978 }
 979 EXPORT_SYMBOL_GPL(thermal_of_cooling_device_register);
 980
 981 static void thermal_cooling_device_release(struct device *dev, void *res)
 982 {
 983         thermal_cooling_device_unregister(
 984                                 *(struct thermal_cooling_device **)res);
 985 }
 986
 987 /**
 988  * devm_thermal_of_cooling_device_register() - register an OF thermal cooling
 989  *                                             device
 990  * @dev:        a valid struct device pointer of a sensor device.
 991  * @np:         a pointer to a device tree node.
 992  * @type:       the thermal cooling device type.
 993  * @devdata:    device private data.
 994  * @ops:        standard thermal cooling devices callbacks.
 995  *
 996  * This function will register a cooling device with device tree node reference.
 997  * This interface function adds a new thermal cooling device (fan/processor/...)
 998  * to /sys/class/thermal/ folder as cooling_device[0-*]. It tries to bind itself
 999  * to all the thermal zone devices registered at the same time.
1000  *
1001  * Return: a pointer to the created struct thermal_cooling_device or an
1002  * ERR_PTR. Caller must check return value with IS_ERR*() helpers.
1003  */
1004 struct thermal_cooling_device *
1005 devm_thermal_of_cooling_device_register(struct device *dev,
1006                                 struct device_node *np,
1007                                 char *type, void *devdata,
1008                                 const struct thermal_cooling_device_ops *ops)
1009 {
1010         struct thermal_cooling_device **ptr, *tcd;
1011
1012         ptr = devres_alloc(thermal_cooling_device_release, sizeof(*ptr),
1013                            GFP_KERNEL);
1014         if (!ptr)
1015                 return ERR_PTR(-ENOMEM);
1016
1017         tcd = __thermal_cooling_device_register(np, type, devdata, ops);
1018         if (IS_ERR(tcd)) {
1019                 devres_free(ptr);
1020                 return tcd;
1021         }
1022
1023         *ptr = tcd;
1024         devres_add(dev, ptr);
1025
1026         return tcd;
1027 }
1028 EXPORT_SYMBOL_GPL(devm_thermal_of_cooling_device_register);
1029
1030 static bool thermal_cooling_device_present(struct thermal_cooling_device *cdev)
1031 {
1032         struct thermal_cooling_device *pos = NULL;
1033
1034         list_for_each_entry(pos, &thermal_cdev_list, node) {
1035                 if (pos == cdev)
1036                         return true;
1037         }
1038
1039         return false;
1040 }
1041
1042 /**
1043  * thermal_cooling_device_update - Update a cooling device object
1044  * @cdev: Target cooling device.
1045  *
1046  * Update @cdev to reflect a change of the underlying hardware or platform.
1047  *
1048  * Must be called when the maximum cooling state of @cdev becomes invalid and so
1049  * its .get_max_state() callback needs to be run to produce the new maximum
1050  * cooling state value.
1051  */
1052 void thermal_cooling_device_update(struct thermal_cooling_device *cdev)
1053 {
1054         struct thermal_instance *ti;
1055         unsigned long state;
1056
1057         if (IS_ERR_OR_NULL(cdev))
1058                 return;
1059
1060         /*
1061          * Hold thermal_list_lock throughout the update to prevent the device
1062          * from going away while being updated.
1063          */
1064         mutex_lock(&thermal_list_lock);
1065
1066         if (!thermal_cooling_device_present(cdev))
1067                 goto unlock_list;
1068
1069         /*
1070          * Update under the cdev lock to prevent the state from being set beyond
1071          * the new limit concurrently.
1072          */
1073         mutex_lock(&cdev->lock);
1074
1075         if (cdev->ops->get_max_state(cdev, &cdev->max_state))
1076                 goto unlock;
1077
1078         thermal_cooling_device_stats_reinit(cdev);
1079
1080         list_for_each_entry(ti, &cdev->thermal_instances, cdev_node) {
1081                 if (ti->upper == cdev->max_state)
1082                         continue;
1083
1084                 if (ti->upper < cdev->max_state) {
1085                         if (ti->upper_no_limit)
1086                                 ti->upper = cdev->max_state;
1087
1088                         continue;
1089                 }
1090
1091                 ti->upper = cdev->max_state;
1092                 if (ti->lower > ti->upper)
1093                         ti->lower = ti->upper;
1094
1095                 if (ti->target == THERMAL_NO_TARGET)
1096                         continue;
1097
1098                 if (ti->target > ti->upper)
1099                         ti->target = ti->upper;
1100         }
1101
1102         if (cdev->ops->get_cur_state(cdev, &state) || state > cdev->max_state)
1103                 goto unlock;
1104
1105         thermal_cooling_device_stats_update(cdev, state);
1106
1107 unlock:
1108         mutex_unlock(&cdev->lock);
1109
1110 unlock_list:
1111         mutex_unlock(&thermal_list_lock);
1112 }
1113 EXPORT_SYMBOL_GPL(thermal_cooling_device_update);
1114
1115 /**
1116  * thermal_cooling_device_unregister - removes a thermal cooling device
1117  * @cdev:       the thermal cooling device to remove.
1118  *
1119  * thermal_cooling_device_unregister() must be called when a registered
1120  * thermal cooling device is no longer needed.
1121  */
1122 void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
1123 {
1124         struct thermal_zone_device *tz;
1125
1126         if (!cdev)
1127                 return;
1128
1129         mutex_lock(&thermal_list_lock);
1130
1131         if (!thermal_cooling_device_present(cdev)) {
1132                 mutex_unlock(&thermal_list_lock);
1133                 return;
1134         }
1135
1136         list_del(&cdev->node);
1137
1138         /* Unbind all thermal zones associated with 'this' cdev */
1139         list_for_each_entry(tz, &thermal_tz_list, node) {
1140                 if (tz->ops->unbind)
1141                         tz->ops->unbind(tz, cdev);
1142         }
1143
1144         mutex_unlock(&thermal_list_lock);
1145
1146         device_unregister(&cdev->device);
1147 }
1148 EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister);
1149
1150 static void bind_tz(struct thermal_zone_device *tz)
1151 {
1152         int ret;
1153         struct thermal_cooling_device *pos = NULL;
1154
1155         if (!tz->ops->bind)
1156                 return;
1157
1158         mutex_lock(&thermal_list_lock);
1159
1160         list_for_each_entry(pos, &thermal_cdev_list, node) {
1161                 ret = tz->ops->bind(tz, pos);
1162                 if (ret)
1163                         print_bind_err_msg(tz, pos, ret);
1164         }
1165
1166         mutex_unlock(&thermal_list_lock);
1167 }
1168
1169 static void thermal_set_delay_jiffies(unsigned long *delay_jiffies, int delay_ms)
1170 {
1171         *delay_jiffies = msecs_to_jiffies(delay_ms);
1172         if (delay_ms > 1000)
1173                 *delay_jiffies = round_jiffies(*delay_jiffies);
1174 }
1175
1176 int thermal_zone_get_crit_temp(struct thermal_zone_device *tz, int *temp)
1177 {
1178         int i, ret = -EINVAL;
1179
1180         if (tz->ops->get_crit_temp)
1181                 return tz->ops->get_crit_temp(tz, temp);
1182
1183         if (!tz->trips)
1184                 return -EINVAL;
1185
1186         mutex_lock(&tz->lock);
1187
1188         for (i = 0; i < tz->num_trips; i++) {
1189                 if (tz->trips[i].type == THERMAL_TRIP_CRITICAL) {
1190                         *temp = tz->trips[i].temperature;
1191                         ret = 0;
1192                         break;
1193                 }
1194         }
1195
1196         mutex_unlock(&tz->lock);
1197
1198         return ret;
1199 }
1200 EXPORT_SYMBOL_GPL(thermal_zone_get_crit_temp);
1201
1202 /**
1203  * thermal_zone_device_register_with_trips() - register a new thermal zone device
1204  * @type:       the thermal zone device type
1205  * @trips:      a pointer to an array of thermal trips
1206  * @num_trips:  the number of trip points the thermal zone support
1207  * @mask:       a bit string indicating the writeablility of trip points
1208  * @devdata:    private device data
1209  * @ops:        standard thermal zone device callbacks
1210  * @tzp:        thermal zone platform parameters
1211  * @passive_delay: number of milliseconds to wait between polls when
1212  *                 performing passive cooling
1213  * @polling_delay: number of milliseconds to wait between polls when checking
1214  *                 whether trip points have been crossed (0 for interrupt
1215  *                 driven systems)
1216  *
1217  * This interface function adds a new thermal zone device (sensor) to
1218  * /sys/class/thermal folder as thermal_zone[0-*]. It tries to bind all the
1219  * thermal cooling devices registered at the same time.
1220  * thermal_zone_device_unregister() must be called when the device is no
1221  * longer needed. The passive cooling depends on the .get_trend() return value.
1222  *
1223  * Return: a pointer to the created struct thermal_zone_device or an
1224  * in case of error, an ERR_PTR. Caller must check return value with
1225  * IS_ERR*() helpers.
1226  */
1227 struct thermal_zone_device *
1228 thermal_zone_device_register_with_trips(const char *type, struct thermal_trip *trips, int num_trips, int mask,
1229                                         void *devdata, struct thermal_zone_device_ops *ops,
1230                                         const struct thermal_zone_params *tzp, int passive_delay,
1231                                         int polling_delay)
1232 {
1233         struct thermal_zone_device *tz;
1234         int id;
1235         int result;
1236         int count;
1237         struct thermal_governor *governor;
1238
1239         if (!type || strlen(type) == 0) {
1240                 pr_err("No thermal zone type defined\n");
1241                 return ERR_PTR(-EINVAL);
1242         }
1243
1244         if (strlen(type) >= THERMAL_NAME_LENGTH) {
1245                 pr_err("Thermal zone name (%s) too long, should be under %d chars\n",
1246                        type, THERMAL_NAME_LENGTH);
1247                 return ERR_PTR(-EINVAL);
1248         }
1249
1250         /*
1251          * Max trip count can't exceed 31 as the "mask >> num_trips" condition.
1252          * For example, shifting by 32 will result in compiler warning:
1253          * warning: right shift count >= width of type [-Wshift-count- overflow]
1254          *
1255          * Also "mask >> num_trips" will always be true with 32 bit shift.
1256          * E.g. mask = 0x80000000 for trip id 31 to be RW. Then
1257          * mask >> 32 = 0x80000000
1258          * This will result in failure for the below condition.
1259          *
1260          * Check will be true when the bit 31 of the mask is set.
1261          * 32 bit shift will cause overflow of 4 byte integer.
1262          */
1263         if (num_trips > (BITS_PER_TYPE(int) - 1) || num_trips < 0 || mask >> num_trips) {
1264                 pr_err("Incorrect number of thermal trips\n");
1265                 return ERR_PTR(-EINVAL);
1266         }
1267
1268         if (!ops) {
1269                 pr_err("Thermal zone device ops not defined\n");
1270                 return ERR_PTR(-EINVAL);
1271         }
1272
1273         if (num_trips > 0 && !trips)
1274                 return ERR_PTR(-EINVAL);
1275
1276         if (!thermal_class)
1277                 return ERR_PTR(-ENODEV);
1278
1279         tz = kzalloc(sizeof(*tz), GFP_KERNEL);
1280         if (!tz)
1281                 return ERR_PTR(-ENOMEM);
1282
1283         if (tzp) {
1284                 tz->tzp = kmemdup(tzp, sizeof(*tzp), GFP_KERNEL);
1285                 if (!tz->tzp) {
1286                         result = -ENOMEM;
1287                         goto free_tz;
1288                 }
1289         }
1290
1291         INIT_LIST_HEAD(&tz->thermal_instances);
1292         ida_init(&tz->ida);
1293         mutex_init(&tz->lock);
1294         id = ida_alloc(&thermal_tz_ida, GFP_KERNEL);
1295         if (id < 0) {
1296                 result = id;
1297                 goto free_tzp;
1298         }
1299
1300         tz->id = id;
1301         strscpy(tz->type, type, sizeof(tz->type));
1302
1303         if (!ops->critical)
1304                 ops->critical = thermal_zone_device_critical;
1305
1306         tz->ops = ops;
1307         tz->device.class = thermal_class;
1308         tz->devdata = devdata;
1309         tz->trips = trips;
1310         tz->num_trips = num_trips;
1311
1312         thermal_set_delay_jiffies(&tz->passive_delay_jiffies, passive_delay);
1313         thermal_set_delay_jiffies(&tz->polling_delay_jiffies, polling_delay);
1314
1315         /* sys I/F */
1316         /* Add nodes that are always present via .groups */
1317         result = thermal_zone_create_device_groups(tz, mask);
1318         if (result)
1319                 goto remove_id;
1320
1321         /* A new thermal zone needs to be updated anyway. */
1322         atomic_set(&tz->need_update, 1);
1323
1324         result = dev_set_name(&tz->device, "thermal_zone%d", tz->id);
1325         if (result) {
1326                 thermal_zone_destroy_device_groups(tz);
1327                 goto remove_id;
1328         }
1329         result = device_register(&tz->device);
1330         if (result)
1331                 goto release_device;
1332
1333         for (count = 0; count < num_trips; count++) {
1334                 struct thermal_trip trip;
1335
1336                 result = thermal_zone_get_trip(tz, count, &trip);
1337                 if (result || !trip.temperature)
1338                         set_bit(count, &tz->trips_disabled);
1339         }
1340
1341         /* Update 'this' zone's governor information */
1342         mutex_lock(&thermal_governor_lock);
1343
1344         if (tz->tzp)
1345                 governor = __find_governor(tz->tzp->governor_name);
1346         else
1347                 governor = def_governor;
1348
1349         result = thermal_set_governor(tz, governor);
1350         if (result) {
1351                 mutex_unlock(&thermal_governor_lock);
1352                 goto unregister;
1353         }
1354
1355         mutex_unlock(&thermal_governor_lock);
1356
1357         if (!tz->tzp || !tz->tzp->no_hwmon) {
1358                 result = thermal_add_hwmon_sysfs(tz);
1359                 if (result)
1360                         goto unregister;
1361         }
1362
1363         mutex_lock(&thermal_list_lock);
1364         list_add_tail(&tz->node, &thermal_tz_list);
1365         mutex_unlock(&thermal_list_lock);
1366
1367         /* Bind cooling devices for this zone */
1368         bind_tz(tz);
1369
1370         INIT_DELAYED_WORK(&tz->poll_queue, thermal_zone_device_check);
1371
1372         thermal_zone_device_init(tz);
1373         /* Update the new thermal zone and mark it as already updated. */
1374         if (atomic_cmpxchg(&tz->need_update, 1, 0))
1375                 thermal_zone_device_update(tz, THERMAL_EVENT_UNSPECIFIED);
1376
1377         thermal_notify_tz_create(tz->id, tz->type);
1378
1379         return tz;
1380
1381 unregister:
1382         device_del(&tz->device);
1383 release_device:
1384         put_device(&tz->device);
1385         tz = NULL;
1386 remove_id:
1387         ida_free(&thermal_tz_ida, id);
1388 free_tzp:
1389         kfree(tz->tzp);
1390 free_tz:
1391         kfree(tz);
1392         return ERR_PTR(result);
1393 }
1394 EXPORT_SYMBOL_GPL(thermal_zone_device_register_with_trips);
1395
1396 struct thermal_zone_device *thermal_tripless_zone_device_register(
1397                                         const char *type,
1398                                         void *devdata,
1399                                         struct thermal_zone_device_ops *ops,
1400                                         const struct thermal_zone_params *tzp)
1401 {
1402         return thermal_zone_device_register_with_trips(type, NULL, 0, 0, devdata,
1403                                                        ops, tzp, 0, 0);
1404 }
1405 EXPORT_SYMBOL_GPL(thermal_tripless_zone_device_register);
1406
1407 void *thermal_zone_device_priv(struct thermal_zone_device *tzd)
1408 {
1409         return tzd->devdata;
1410 }
1411 EXPORT_SYMBOL_GPL(thermal_zone_device_priv);
1412
1413 const char *thermal_zone_device_type(struct thermal_zone_device *tzd)
1414 {
1415         return tzd->type;
1416 }
1417 EXPORT_SYMBOL_GPL(thermal_zone_device_type);
1418
1419 int thermal_zone_device_id(struct thermal_zone_device *tzd)
1420 {
1421         return tzd->id;
1422 }
1423 EXPORT_SYMBOL_GPL(thermal_zone_device_id);
1424
1425 struct device *thermal_zone_device(struct thermal_zone_device *tzd)
1426 {
1427         return &tzd->device;
1428 }
1429 EXPORT_SYMBOL_GPL(thermal_zone_device);
1430
1431 /**
1432  * thermal_zone_device_unregister - removes the registered thermal zone device
1433  * @tz: the thermal zone device to remove
1434  */
1435 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
1436 {
1437         int tz_id;
1438         struct thermal_cooling_device *cdev;
1439         struct thermal_zone_device *pos = NULL;
1440
1441         if (!tz)
1442                 return;
1443
1444         tz_id = tz->id;
1445
1446         mutex_lock(&thermal_list_lock);
1447         list_for_each_entry(pos, &thermal_tz_list, node)
1448                 if (pos == tz)
1449                         break;
1450         if (pos != tz) {
1451                 /* thermal zone device not found */
1452                 mutex_unlock(&thermal_list_lock);
1453                 return;
1454         }
1455         list_del(&tz->node);
1456
1457         /* Unbind all cdevs associated with 'this' thermal zone */
1458         list_for_each_entry(cdev, &thermal_cdev_list, node)
1459                 if (tz->ops->unbind)
1460                         tz->ops->unbind(tz, cdev);
1461
1462         mutex_unlock(&thermal_list_lock);
1463
1464         cancel_delayed_work_sync(&tz->poll_queue);
1465
1466         thermal_set_governor(tz, NULL);
1467
1468         thermal_remove_hwmon_sysfs(tz);
1469         ida_free(&thermal_tz_ida, tz->id);
1470         ida_destroy(&tz->ida);
1471
1472         mutex_lock(&tz->lock);
1473         device_del(&tz->device);
1474         mutex_unlock(&tz->lock);
1475
1476         kfree(tz->tzp);
1477
1478         put_device(&tz->device);
1479
1480         thermal_notify_tz_delete(tz_id);
1481 }
1482 EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
1483
1484 /**
1485  * thermal_zone_get_zone_by_name() - search for a zone and returns its ref
1486  * @name: thermal zone name to fetch the temperature
1487  *
1488  * When only one zone is found with the passed name, returns a reference to it.
1489  *
1490  * Return: On success returns a reference to an unique thermal zone with
1491  * matching name equals to @name, an ERR_PTR otherwise (-EINVAL for invalid
1492  * paramenters, -ENODEV for not found and -EEXIST for multiple matches).
1493  */
1494 struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
1495 {
1496         struct thermal_zone_device *pos = NULL, *ref = ERR_PTR(-EINVAL);
1497         unsigned int found = 0;
1498
1499         if (!name)
1500                 goto exit;
1501
1502         mutex_lock(&thermal_list_lock);
1503         list_for_each_entry(pos, &thermal_tz_list, node)
1504                 if (!strncasecmp(name, pos->type, THERMAL_NAME_LENGTH)) {
1505                         found++;
1506                         ref = pos;
1507                 }
1508         mutex_unlock(&thermal_list_lock);
1509
1510         /* nothing has been found, thus an error code for it */
1511         if (found == 0)
1512                 ref = ERR_PTR(-ENODEV);
1513         else if (found > 1)
1514         /* Success only when an unique zone is found */
1515                 ref = ERR_PTR(-EEXIST);
1516
1517 exit:
1518         return ref;
1519 }
1520 EXPORT_SYMBOL_GPL(thermal_zone_get_zone_by_name);
1521
1522 static int thermal_pm_notify(struct notifier_block *nb,
1523                              unsigned long mode, void *_unused)
1524 {
1525         struct thermal_zone_device *tz;
1526
1527         switch (mode) {
1528         case PM_HIBERNATION_PREPARE:
1529         case PM_RESTORE_PREPARE:
1530         case PM_SUSPEND_PREPARE:
1531                 atomic_set(&in_suspend, 1);
1532                 break;
1533         case PM_POST_HIBERNATION:
1534         case PM_POST_RESTORE:
1535         case PM_POST_SUSPEND:
1536                 atomic_set(&in_suspend, 0);
1537                 list_for_each_entry(tz, &thermal_tz_list, node) {
1538                         thermal_zone_device_init(tz);
1539                         thermal_zone_device_update(tz,
1540                                                    THERMAL_EVENT_UNSPECIFIED);
1541                 }
1542                 break;
1543         default:
1544                 break;
1545         }
1546         return 0;
1547 }
1548
1549 static struct notifier_block thermal_pm_nb = {
1550         .notifier_call = thermal_pm_notify,
1551 };
1552
1553 static int __init thermal_init(void)
1554 {
1555         int result;
1556
1557         result = thermal_netlink_init();
1558         if (result)
1559                 goto error;
1560
1561         result = thermal_register_governors();
1562         if (result)
1563                 goto unregister_netlink;
1564
1565         thermal_class = kzalloc(sizeof(*thermal_class), GFP_KERNEL);
1566         if (!thermal_class) {
1567                 result = -ENOMEM;
1568                 goto unregister_governors;
1569         }
1570
1571         thermal_class->name = "thermal";
1572         thermal_class->dev_release = thermal_release;
1573
1574         result = class_register(thermal_class);
1575         if (result) {
1576                 kfree(thermal_class);
1577                 thermal_class = NULL;
1578                 goto unregister_governors;
1579         }
1580
1581         result = register_pm_notifier(&thermal_pm_nb);
1582         if (result)
1583                 pr_warn("Thermal: Can not register suspend notifier, return %d\n",
1584                         result);
1585
1586         return 0;
1587
1588 unregister_governors:
1589         thermal_unregister_governors();
1590 unregister_netlink:
1591         thermal_netlink_exit();
1592 error:
1593         mutex_destroy(&thermal_list_lock);
1594         mutex_destroy(&thermal_governor_lock);
1595         return result;
1596 }
1597 postcore_initcall(thermal_init);