git.oblomov.eu Git - linux-2.6/blob - drivers/thermal/thermal.c

   1 /*
   2  *  thermal.c - Generic Thermal Management Sysfs support.
   3  *
   4  *  Copyright (C) 2008 Intel Corp
   5  *  Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com>
   6  *  Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com>
   7  *
   8  *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; version 2 of the License.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/device.h>
  28 #include <linux/err.h>
  29 #include <linux/kdev_t.h>
  30 #include <linux/idr.h>
  31 #include <linux/thermal.h>
  32 #include <linux/spinlock.h>
  33
  34 MODULE_AUTHOR("Zhang Rui")
  35 MODULE_DESCRIPTION("Generic thermal management sysfs support");
  36 MODULE_LICENSE("GPL");
  37
  38 #define PREFIX "Thermal: "
  39
  40 struct thermal_cooling_device_instance {
  41         int id;
  42         char name[THERMAL_NAME_LENGTH];
  43         struct thermal_zone_device *tz;
  44         struct thermal_cooling_device *cdev;
  45         int trip;
  46         char attr_name[THERMAL_NAME_LENGTH];
  47         struct device_attribute attr;
  48         struct list_head node;
  49 };
  50
  51 static DEFINE_IDR(thermal_tz_idr);
  52 static DEFINE_IDR(thermal_cdev_idr);
  53 static DEFINE_MUTEX(thermal_idr_lock);
  54
  55 static LIST_HEAD(thermal_tz_list);
  56 static LIST_HEAD(thermal_cdev_list);
  57 static DEFINE_MUTEX(thermal_list_lock);
  58
  59 static int get_idr(struct idr *idr, struct mutex *lock, int *id)
  60 {
  61         int err;
  62
  63       again:
  64         if (unlikely(idr_pre_get(idr, GFP_KERNEL) == 0))
  65                 return -ENOMEM;
  66
  67         if (lock)
  68                 mutex_lock(lock);
  69         err = idr_get_new(idr, NULL, id);
  70         if (lock)
  71                 mutex_unlock(lock);
  72         if (unlikely(err == -EAGAIN))
  73                 goto again;
  74         else if (unlikely(err))
  75                 return err;
  76
  77         *id = *id & MAX_ID_MASK;
  78         return 0;
  79 }
  80
  81 static void release_idr(struct idr *idr, struct mutex *lock, int id)
  82 {
  83         if (lock)
  84                 mutex_lock(lock);
  85         idr_remove(idr, id);
  86         if (lock)
  87                 mutex_unlock(lock);
  88 }
  89
  90 /* sys I/F for thermal zone */
  91
  92 #define to_thermal_zone(_dev) \
  93         container_of(_dev, struct thermal_zone_device, device)
  94
  95 static ssize_t
  96 type_show(struct device *dev, struct device_attribute *attr, char *buf)
  97 {
  98         struct thermal_zone_device *tz = to_thermal_zone(dev);
  99
 100         return sprintf(buf, "%s\n", tz->type);
 101 }
 102
 103 static ssize_t
 104 temp_show(struct device *dev, struct device_attribute *attr, char *buf)
 105 {
 106         struct thermal_zone_device *tz = to_thermal_zone(dev);
 107
 108         if (!tz->ops->get_temp)
 109                 return -EPERM;
 110
 111         return tz->ops->get_temp(tz, buf);
 112 }
 113
 114 static ssize_t
 115 mode_show(struct device *dev, struct device_attribute *attr, char *buf)
 116 {
 117         struct thermal_zone_device *tz = to_thermal_zone(dev);
 118
 119         if (!tz->ops->get_mode)
 120                 return -EPERM;
 121
 122         return tz->ops->get_mode(tz, buf);
 123 }
 124
 125 static ssize_t
 126 mode_store(struct device *dev, struct device_attribute *attr,
 127            const char *buf, size_t count)
 128 {
 129         struct thermal_zone_device *tz = to_thermal_zone(dev);
 130         int result;
 131
 132         if (!tz->ops->set_mode)
 133                 return -EPERM;
 134
 135         result = tz->ops->set_mode(tz, buf);
 136         if (result)
 137                 return result;
 138
 139         return count;
 140 }
 141
 142 static ssize_t
 143 trip_point_type_show(struct device *dev, struct device_attribute *attr,
 144                      char *buf)
 145 {
 146         struct thermal_zone_device *tz = to_thermal_zone(dev);
 147         int trip;
 148
 149         if (!tz->ops->get_trip_type)
 150                 return -EPERM;
 151
 152         if (!sscanf(attr->attr.name, "trip_point_%d_type", &trip))
 153                 return -EINVAL;
 154
 155         return tz->ops->get_trip_type(tz, trip, buf);
 156 }
 157
 158 static ssize_t
 159 trip_point_temp_show(struct device *dev, struct device_attribute *attr,
 160                      char *buf)
 161 {
 162         struct thermal_zone_device *tz = to_thermal_zone(dev);
 163         int trip;
 164
 165         if (!tz->ops->get_trip_temp)
 166                 return -EPERM;
 167
 168         if (!sscanf(attr->attr.name, "trip_point_%d_temp", &trip))
 169                 return -EINVAL;
 170
 171         return tz->ops->get_trip_temp(tz, trip, buf);
 172 }
 173
 174 static DEVICE_ATTR(type, 0444, type_show, NULL);
 175 static DEVICE_ATTR(temp, 0444, temp_show, NULL);
 176 static DEVICE_ATTR(mode, 0644, mode_show, mode_store);
 177
 178 static struct device_attribute trip_point_attrs[] = {
 179         __ATTR(trip_point_0_type, 0444, trip_point_type_show, NULL),
 180         __ATTR(trip_point_0_temp, 0444, trip_point_temp_show, NULL),
 181         __ATTR(trip_point_1_type, 0444, trip_point_type_show, NULL),
 182         __ATTR(trip_point_1_temp, 0444, trip_point_temp_show, NULL),
 183         __ATTR(trip_point_2_type, 0444, trip_point_type_show, NULL),
 184         __ATTR(trip_point_2_temp, 0444, trip_point_temp_show, NULL),
 185         __ATTR(trip_point_3_type, 0444, trip_point_type_show, NULL),
 186         __ATTR(trip_point_3_temp, 0444, trip_point_temp_show, NULL),
 187         __ATTR(trip_point_4_type, 0444, trip_point_type_show, NULL),
 188         __ATTR(trip_point_4_temp, 0444, trip_point_temp_show, NULL),
 189         __ATTR(trip_point_5_type, 0444, trip_point_type_show, NULL),
 190         __ATTR(trip_point_5_temp, 0444, trip_point_temp_show, NULL),
 191         __ATTR(trip_point_6_type, 0444, trip_point_type_show, NULL),
 192         __ATTR(trip_point_6_temp, 0444, trip_point_temp_show, NULL),
 193         __ATTR(trip_point_7_type, 0444, trip_point_type_show, NULL),
 194         __ATTR(trip_point_7_temp, 0444, trip_point_temp_show, NULL),
 195         __ATTR(trip_point_8_type, 0444, trip_point_type_show, NULL),
 196         __ATTR(trip_point_8_temp, 0444, trip_point_temp_show, NULL),
 197         __ATTR(trip_point_9_type, 0444, trip_point_type_show, NULL),
 198         __ATTR(trip_point_9_temp, 0444, trip_point_temp_show, NULL),
 199 };
 200
 201 #define TRIP_POINT_ATTR_ADD(_dev, _index, result)     \
 202 do {    \
 203         result = device_create_file(_dev,       \
 204                                 &trip_point_attrs[_index * 2]); \
 205         if (result)     \
 206                 break;  \
 207         result = device_create_file(_dev,       \
 208                         &trip_point_attrs[_index * 2 + 1]);     \
 209 } while (0)
 210
 211 #define TRIP_POINT_ATTR_REMOVE(_dev, _index)    \
 212 do {    \
 213         device_remove_file(_dev, &trip_point_attrs[_index * 2]);        \
 214         device_remove_file(_dev, &trip_point_attrs[_index * 2 + 1]);    \
 215 } while (0)
 216
 217 /* sys I/F for cooling device */
 218 #define to_cooling_device(_dev) \
 219         container_of(_dev, struct thermal_cooling_device, device)
 220
 221 static ssize_t
 222 thermal_cooling_device_type_show(struct device *dev,
 223                                  struct device_attribute *attr, char *buf)
 224 {
 225         struct thermal_cooling_device *cdev = to_cooling_device(dev);
 226
 227         return sprintf(buf, "%s\n", cdev->type);
 228 }
 229
 230 static ssize_t
 231 thermal_cooling_device_max_state_show(struct device *dev,
 232                                       struct device_attribute *attr, char *buf)
 233 {
 234         struct thermal_cooling_device *cdev = to_cooling_device(dev);
 235
 236         return cdev->ops->get_max_state(cdev, buf);
 237 }
 238
 239 static ssize_t
 240 thermal_cooling_device_cur_state_show(struct device *dev,
 241                                       struct device_attribute *attr, char *buf)
 242 {
 243         struct thermal_cooling_device *cdev = to_cooling_device(dev);
 244
 245         return cdev->ops->get_cur_state(cdev, buf);
 246 }
 247
 248 static ssize_t
 249 thermal_cooling_device_cur_state_store(struct device *dev,
 250                                        struct device_attribute *attr,
 251                                        const char *buf, size_t count)
 252 {
 253         struct thermal_cooling_device *cdev = to_cooling_device(dev);
 254         int state;
 255         int result;
 256
 257         if (!sscanf(buf, "%d\n", &state))
 258                 return -EINVAL;
 259
 260         if (state < 0)
 261                 return -EINVAL;
 262
 263         result = cdev->ops->set_cur_state(cdev, state);
 264         if (result)
 265                 return result;
 266         return count;
 267 }
 268
 269 static struct device_attribute dev_attr_cdev_type =
 270                 __ATTR(type, 0444, thermal_cooling_device_type_show, NULL);
 271 static DEVICE_ATTR(max_state, 0444,
 272                    thermal_cooling_device_max_state_show, NULL);
 273 static DEVICE_ATTR(cur_state, 0644,
 274                    thermal_cooling_device_cur_state_show,
 275                    thermal_cooling_device_cur_state_store);
 276
 277 static ssize_t
 278 thermal_cooling_device_trip_point_show(struct device *dev,
 279                                     struct device_attribute *attr, char *buf)
 280 {
 281         struct thermal_cooling_device_instance *instance;
 282
 283         instance =
 284             container_of(attr, struct thermal_cooling_device_instance, attr);
 285
 286         if (instance->trip == THERMAL_TRIPS_NONE)
 287                 return sprintf(buf, "-1\n");
 288         else
 289                 return sprintf(buf, "%d\n", instance->trip);
 290 }
 291
 292 /* Device management */
 293
 294 /**
 295  * thermal_zone_bind_cooling_device - bind a cooling device to a thermal zone
 296  * this function is usually called in the thermal zone device .bind callback.
 297  * @tz:         thermal zone device
 298  * @trip:       indicates which trip point the cooling devices is
 299  *              associated with in this thermal zone.
 300  * @cdev:       thermal cooling device
 301  */
 302 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 303                                      int trip,
 304                                      struct thermal_cooling_device *cdev)
 305 {
 306         struct thermal_cooling_device_instance *dev;
 307         struct thermal_cooling_device_instance *pos;
 308         int result;
 309
 310         if (trip >= tz->trips ||
 311             (trip < 0 && trip != THERMAL_TRIPS_NONE))
 312                 return -EINVAL;
 313
 314         if (!tz || !cdev)
 315                 return -EINVAL;
 316
 317         dev =
 318             kzalloc(sizeof(struct thermal_cooling_device_instance), GFP_KERNEL);
 319         if (!dev)
 320                 return -ENOMEM;
 321         dev->tz = tz;
 322         dev->cdev = cdev;
 323         dev->trip = trip;
 324         result = get_idr(&tz->idr, &tz->lock, &dev->id);
 325         if (result)
 326                 goto free_mem;
 327
 328         sprintf(dev->name, "cdev%d", dev->id);
 329         result =
 330             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 331         if (result)
 332                 goto release_idr;
 333
 334         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 335         dev->attr.attr.name = dev->attr_name;
 336         dev->attr.attr.mode = 0444;
 337         dev->attr.show = thermal_cooling_device_trip_point_show;
 338         result = device_create_file(&tz->device, &dev->attr);
 339         if (result)
 340                 goto remove_symbol_link;
 341
 342         mutex_lock(&tz->lock);
 343         list_for_each_entry(pos, &tz->cooling_devices, node)
 344             if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 345                 result = -EEXIST;
 346                 break;
 347         }
 348         if (!result)
 349                 list_add_tail(&dev->node, &tz->cooling_devices);
 350         mutex_unlock(&tz->lock);
 351
 352         if (!result)
 353                 return 0;
 354
 355         device_remove_file(&tz->device, &dev->attr);
 356       remove_symbol_link:
 357         sysfs_remove_link(&tz->device.kobj, dev->name);
 358       release_idr:
 359         release_idr(&tz->idr, &tz->lock, dev->id);
 360       free_mem:
 361         kfree(dev);
 362         return result;
 363 }
 364 EXPORT_SYMBOL(thermal_zone_bind_cooling_device);
 365
 366 /**
 367  * thermal_zone_unbind_cooling_device - unbind a cooling device from a thermal zone
 368  * this function is usually called in the thermal zone device .unbind callback.
 369  * @tz:         thermal zone device
 370  * @trip:       indicates which trip point the cooling devices is
 371  *              associated with in this thermal zone.
 372  * @cdev:       thermal cooling device
 373  */
 374 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 375                                        int trip,
 376                                        struct thermal_cooling_device *cdev)
 377 {
 378         struct thermal_cooling_device_instance *pos, *next;
 379
 380         mutex_lock(&tz->lock);
 381         list_for_each_entry_safe(pos, next, &tz->cooling_devices, node) {
 382                 if (pos->tz == tz && pos->trip == trip
 383                     && pos->cdev == cdev) {
 384                         list_del(&pos->node);
 385                         mutex_unlock(&tz->lock);
 386                         goto unbind;
 387                 }
 388         }
 389         mutex_unlock(&tz->lock);
 390
 391         return -ENODEV;
 392
 393       unbind:
 394         device_remove_file(&tz->device, &pos->attr);
 395         sysfs_remove_link(&tz->device.kobj, pos->name);
 396         release_idr(&tz->idr, &tz->lock, pos->id);
 397         kfree(pos);
 398         return 0;
 399 }
 400 EXPORT_SYMBOL(thermal_zone_unbind_cooling_device);
 401
 402 static void thermal_release(struct device *dev)
 403 {
 404         struct thermal_zone_device *tz;
 405         struct thermal_cooling_device *cdev;
 406
 407         if (!strncmp(dev->bus_id, "thermal_zone", sizeof "thermal_zone" - 1)) {
 408                 tz = to_thermal_zone(dev);
 409                 kfree(tz);
 410         } else {
 411                 cdev = to_cooling_device(dev);
 412                 kfree(cdev);
 413         }
 414 }
 415
 416 static struct class thermal_class = {
 417         .name = "thermal",
 418         .dev_release = thermal_release,
 419 };
 420
 421 /**
 422  * thermal_cooling_device_register - register a new thermal cooling device
 423  * @type:       the thermal cooling device type.
 424  * @devdata:    device private data.
 425  * @ops:                standard thermal cooling devices callbacks.
 426  */
 427 struct thermal_cooling_device *thermal_cooling_device_register(char *type,
 428                        void *devdata, struct thermal_cooling_device_ops *ops)
 429 {
 430         struct thermal_cooling_device *cdev;
 431         struct thermal_zone_device *pos;
 432         int result;
 433
 434         if (strlen(type) >= THERMAL_NAME_LENGTH)
 435                 return NULL;
 436
 437         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
 438                 !ops->set_cur_state)
 439                 return NULL;
 440
 441         cdev = kzalloc(sizeof(struct thermal_cooling_device), GFP_KERNEL);
 442         if (!cdev)
 443                 return NULL;
 444
 445         result = get_idr(&thermal_cdev_idr, &thermal_idr_lock, &cdev->id);
 446         if (result) {
 447                 kfree(cdev);
 448                 return NULL;
 449         }
 450
 451         strcpy(cdev->type, type);
 452         cdev->ops = ops;
 453         cdev->device.class = &thermal_class;
 454         cdev->devdata = devdata;
 455         sprintf(cdev->device.bus_id, "cooling_device%d", cdev->id);
 456         result = device_register(&cdev->device);
 457         if (result) {
 458                 release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
 459                 kfree(cdev);
 460                 return NULL;
 461         }
 462
 463         /* sys I/F */
 464         if (type) {
 465                 result = device_create_file(&cdev->device,
 466                                             &dev_attr_cdev_type);
 467                 if (result)
 468                         goto unregister;
 469         }
 470
 471         result = device_create_file(&cdev->device, &dev_attr_max_state);
 472         if (result)
 473                 goto unregister;
 474
 475         result = device_create_file(&cdev->device, &dev_attr_cur_state);
 476         if (result)
 477                 goto unregister;
 478
 479         mutex_lock(&thermal_list_lock);
 480         list_add(&cdev->node, &thermal_cdev_list);
 481         list_for_each_entry(pos, &thermal_tz_list, node) {
 482                 if (!pos->ops->bind)
 483                         continue;
 484                 result = pos->ops->bind(pos, cdev);
 485                 if (result)
 486                         break;
 487
 488         }
 489         mutex_unlock(&thermal_list_lock);
 490
 491         if (!result)
 492                 return cdev;
 493
 494       unregister:
 495         release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
 496         device_unregister(&cdev->device);
 497         return NULL;
 498 }
 499 EXPORT_SYMBOL(thermal_cooling_device_register);
 500
 501 /**
 502  * thermal_cooling_device_unregister - removes the registered thermal cooling device
 503  *
 504  * @cdev:       the thermal cooling device to remove.
 505  *
 506  * thermal_cooling_device_unregister() must be called when the device is no
 507  * longer needed.
 508  */
 509 void thermal_cooling_device_unregister(struct
 510                                        thermal_cooling_device
 511                                        *cdev)
 512 {
 513         struct thermal_zone_device *tz;
 514         struct thermal_cooling_device *pos = NULL;
 515
 516         if (!cdev)
 517                 return;
 518
 519         mutex_lock(&thermal_list_lock);
 520         list_for_each_entry(pos, &thermal_cdev_list, node)
 521             if (pos == cdev)
 522                 break;
 523         if (pos != cdev) {
 524                 /* thermal cooling device not found */
 525                 mutex_unlock(&thermal_list_lock);
 526                 return;
 527         }
 528         list_del(&cdev->node);
 529         list_for_each_entry(tz, &thermal_tz_list, node) {
 530                 if (!tz->ops->unbind)
 531                         continue;
 532                 tz->ops->unbind(tz, cdev);
 533         }
 534         mutex_unlock(&thermal_list_lock);
 535         if (cdev->type[0])
 536                 device_remove_file(&cdev->device,
 537                                    &dev_attr_cdev_type);
 538         device_remove_file(&cdev->device, &dev_attr_max_state);
 539         device_remove_file(&cdev->device, &dev_attr_cur_state);
 540
 541         release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
 542         device_unregister(&cdev->device);
 543         return;
 544 }
 545 EXPORT_SYMBOL(thermal_cooling_device_unregister);
 546
 547 /**
 548  * thermal_zone_device_register - register a new thermal zone device
 549  * @type:       the thermal zone device type
 550  * @trips:      the number of trip points the thermal zone support
 551  * @devdata:    private device data
 552  * @ops:        standard thermal zone device callbacks
 553  *
 554  * thermal_zone_device_unregister() must be called when the device is no
 555  * longer needed.
 556  */
 557 struct thermal_zone_device *thermal_zone_device_register(char *type,
 558                                         int trips, void *devdata,
 559                                         struct thermal_zone_device_ops *ops)
 560 {
 561         struct thermal_zone_device *tz;
 562         struct thermal_cooling_device *pos;
 563         int result;
 564         int count;
 565
 566         if (strlen(type) >= THERMAL_NAME_LENGTH)
 567                 return NULL;
 568
 569         if (trips > THERMAL_MAX_TRIPS || trips < 0)
 570                 return NULL;
 571
 572         if (!ops || !ops->get_temp)
 573                 return NULL;
 574
 575         tz = kzalloc(sizeof(struct thermal_zone_device), GFP_KERNEL);
 576         if (!tz)
 577                 return NULL;
 578
 579         INIT_LIST_HEAD(&tz->cooling_devices);
 580         idr_init(&tz->idr);
 581         mutex_init(&tz->lock);
 582         result = get_idr(&thermal_tz_idr, &thermal_idr_lock, &tz->id);
 583         if (result) {
 584                 kfree(tz);
 585                 return NULL;
 586         }
 587
 588         strcpy(tz->type, type);
 589         tz->ops = ops;
 590         tz->device.class = &thermal_class;
 591         tz->devdata = devdata;
 592         tz->trips = trips;
 593         sprintf(tz->device.bus_id, "thermal_zone%d", tz->id);
 594         result = device_register(&tz->device);
 595         if (result) {
 596                 release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
 597                 kfree(tz);
 598                 return NULL;
 599         }
 600
 601         /* sys I/F */
 602         if (type) {
 603                 result = device_create_file(&tz->device, &dev_attr_type);
 604                 if (result)
 605                         goto unregister;
 606         }
 607
 608         result = device_create_file(&tz->device, &dev_attr_temp);
 609         if (result)
 610                 goto unregister;
 611
 612         if (ops->get_mode) {
 613                 result = device_create_file(&tz->device, &dev_attr_mode);
 614                 if (result)
 615                         goto unregister;
 616         }
 617
 618         for (count = 0; count < trips; count++) {
 619                 TRIP_POINT_ATTR_ADD(&tz->device, count, result);
 620                 if (result)
 621                         goto unregister;
 622         }
 623
 624         mutex_lock(&thermal_list_lock);
 625         list_add_tail(&tz->node, &thermal_tz_list);
 626         if (ops->bind)
 627                 list_for_each_entry(pos, &thermal_cdev_list, node) {
 628                         result = ops->bind(tz, pos);
 629                         if (result)
 630                                 break;
 631                 }
 632         mutex_unlock(&thermal_list_lock);
 633
 634         if (!result)
 635                 return tz;
 636
 637       unregister:
 638         release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
 639         device_unregister(&tz->device);
 640         return NULL;
 641 }
 642 EXPORT_SYMBOL(thermal_zone_device_register);
 643
 644 /**
 645  * thermal_device_unregister - removes the registered thermal zone device
 646  *
 647  * @tz: the thermal zone device to remove
 648  */
 649 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 650 {
 651         struct thermal_cooling_device *cdev;
 652         struct thermal_zone_device *pos = NULL;
 653         int count;
 654
 655         if (!tz)
 656                 return;
 657
 658         mutex_lock(&thermal_list_lock);
 659         list_for_each_entry(pos, &thermal_tz_list, node)
 660             if (pos == tz)
 661                 break;
 662         if (pos != tz) {
 663                 /* thermal zone device not found */
 664                 mutex_unlock(&thermal_list_lock);
 665                 return;
 666         }
 667         list_del(&tz->node);
 668         if (tz->ops->unbind)
 669                 list_for_each_entry(cdev, &thermal_cdev_list, node)
 670                     tz->ops->unbind(tz, cdev);
 671         mutex_unlock(&thermal_list_lock);
 672
 673         if (tz->type[0])
 674                 device_remove_file(&tz->device, &dev_attr_type);
 675         device_remove_file(&tz->device, &dev_attr_temp);
 676         if (tz->ops->get_mode)
 677                 device_remove_file(&tz->device, &dev_attr_mode);
 678
 679         for (count = 0; count < tz->trips; count++)
 680                 TRIP_POINT_ATTR_REMOVE(&tz->device, count);
 681
 682         release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
 683         idr_destroy(&tz->idr);
 684         mutex_destroy(&tz->lock);
 685         device_unregister(&tz->device);
 686         return;
 687 }
 688 EXPORT_SYMBOL(thermal_zone_device_unregister);
 689
 690 static int __init thermal_init(void)
 691 {
 692         int result = 0;
 693
 694         result = class_register(&thermal_class);
 695         if (result) {
 696                 idr_destroy(&thermal_tz_idr);
 697                 idr_destroy(&thermal_cdev_idr);
 698                 mutex_destroy(&thermal_idr_lock);
 699                 mutex_destroy(&thermal_list_lock);
 700         }
 701         return result;
 702 }
 703
 704 static void __exit thermal_exit(void)
 705 {
 706         class_unregister(&thermal_class);
 707         idr_destroy(&thermal_tz_idr);
 708         idr_destroy(&thermal_cdev_idr);
 709         mutex_destroy(&thermal_idr_lock);
 710         mutex_destroy(&thermal_list_lock);
 711 }
 712
 713 subsys_initcall(thermal_init);
 714 module_exit(thermal_exit);