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  * @tz:         thermal zone device
 297  * @trip:       indicates which trip point the cooling devices is
 298  *              associated with in this thermal zone.
 299  * @cdev:       thermal cooling device
 300  *
 301  * This function is usually called in the thermal zone device .bind callback.
 302  */
 303 int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz,
 304                                      int trip,
 305                                      struct thermal_cooling_device *cdev)
 306 {
 307         struct thermal_cooling_device_instance *dev;
 308         struct thermal_cooling_device_instance *pos;
 309         struct thermal_zone_device *pos1;
 310         struct thermal_cooling_device *pos2;
 311         int result;
 312
 313         if (trip >= tz->trips || (trip < 0 && trip != THERMAL_TRIPS_NONE))
 314                 return -EINVAL;
 315
 316         list_for_each_entry(pos1, &thermal_tz_list, node) {
 317                 if (pos1 == tz)
 318                         break;
 319         }
 320         list_for_each_entry(pos2, &thermal_cdev_list, node) {
 321                 if (pos2 == cdev)
 322                         break;
 323         }
 324
 325         if (tz != pos1 || cdev != pos2)
 326                 return -EINVAL;
 327
 328         dev =
 329             kzalloc(sizeof(struct thermal_cooling_device_instance), GFP_KERNEL);
 330         if (!dev)
 331                 return -ENOMEM;
 332         dev->tz = tz;
 333         dev->cdev = cdev;
 334         dev->trip = trip;
 335         result = get_idr(&tz->idr, &tz->lock, &dev->id);
 336         if (result)
 337                 goto free_mem;
 338
 339         sprintf(dev->name, "cdev%d", dev->id);
 340         result =
 341             sysfs_create_link(&tz->device.kobj, &cdev->device.kobj, dev->name);
 342         if (result)
 343                 goto release_idr;
 344
 345         sprintf(dev->attr_name, "cdev%d_trip_point", dev->id);
 346         dev->attr.attr.name = dev->attr_name;
 347         dev->attr.attr.mode = 0444;
 348         dev->attr.show = thermal_cooling_device_trip_point_show;
 349         result = device_create_file(&tz->device, &dev->attr);
 350         if (result)
 351                 goto remove_symbol_link;
 352
 353         mutex_lock(&tz->lock);
 354         list_for_each_entry(pos, &tz->cooling_devices, node)
 355             if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 356                 result = -EEXIST;
 357                 break;
 358         }
 359         if (!result)
 360                 list_add_tail(&dev->node, &tz->cooling_devices);
 361         mutex_unlock(&tz->lock);
 362
 363         if (!result)
 364                 return 0;
 365
 366         device_remove_file(&tz->device, &dev->attr);
 367       remove_symbol_link:
 368         sysfs_remove_link(&tz->device.kobj, dev->name);
 369       release_idr:
 370         release_idr(&tz->idr, &tz->lock, dev->id);
 371       free_mem:
 372         kfree(dev);
 373         return result;
 374 }
 375
 376 EXPORT_SYMBOL(thermal_zone_bind_cooling_device);
 377
 378 /**
 379  * thermal_zone_unbind_cooling_device - unbind a cooling device from a thermal zone
 380  * @tz:         thermal zone device
 381  * @trip:       indicates which trip point the cooling devices is
 382  *              associated with in this thermal zone.
 383  * @cdev:       thermal cooling device
 384  *
 385  * This function is usually called in the thermal zone device .unbind callback.
 386  */
 387 int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz,
 388                                        int trip,
 389                                        struct thermal_cooling_device *cdev)
 390 {
 391         struct thermal_cooling_device_instance *pos, *next;
 392
 393         mutex_lock(&tz->lock);
 394         list_for_each_entry_safe(pos, next, &tz->cooling_devices, node) {
 395                 if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) {
 396                         list_del(&pos->node);
 397                         mutex_unlock(&tz->lock);
 398                         goto unbind;
 399                 }
 400         }
 401         mutex_unlock(&tz->lock);
 402
 403         return -ENODEV;
 404
 405       unbind:
 406         device_remove_file(&tz->device, &pos->attr);
 407         sysfs_remove_link(&tz->device.kobj, pos->name);
 408         release_idr(&tz->idr, &tz->lock, pos->id);
 409         kfree(pos);
 410         return 0;
 411 }
 412
 413 EXPORT_SYMBOL(thermal_zone_unbind_cooling_device);
 414
 415 static void thermal_release(struct device *dev)
 416 {
 417         struct thermal_zone_device *tz;
 418         struct thermal_cooling_device *cdev;
 419
 420         if (!strncmp(dev->bus_id, "thermal_zone", sizeof "thermal_zone" - 1)) {
 421                 tz = to_thermal_zone(dev);
 422                 kfree(tz);
 423         } else {
 424                 cdev = to_cooling_device(dev);
 425                 kfree(cdev);
 426         }
 427 }
 428
 429 static struct class thermal_class = {
 430         .name = "thermal",
 431         .dev_release = thermal_release,
 432 };
 433
 434 /**
 435  * thermal_cooling_device_register - register a new thermal cooling device
 436  * @type:       the thermal cooling device type.
 437  * @devdata:    device private data.
 438  * @ops:                standard thermal cooling devices callbacks.
 439  */
 440 struct thermal_cooling_device *thermal_cooling_device_register(char *type,
 441                                                                void *devdata,
 442                                                                struct
 443                                                                thermal_cooling_device_ops
 444                                                                *ops)
 445 {
 446         struct thermal_cooling_device *cdev;
 447         struct thermal_zone_device *pos;
 448         int result;
 449
 450         if (strlen(type) >= THERMAL_NAME_LENGTH)
 451                 return NULL;
 452
 453         if (!ops || !ops->get_max_state || !ops->get_cur_state ||
 454             !ops->set_cur_state)
 455                 return NULL;
 456
 457         cdev = kzalloc(sizeof(struct thermal_cooling_device), GFP_KERNEL);
 458         if (!cdev)
 459                 return NULL;
 460
 461         result = get_idr(&thermal_cdev_idr, &thermal_idr_lock, &cdev->id);
 462         if (result) {
 463                 kfree(cdev);
 464                 return NULL;
 465         }
 466
 467         strcpy(cdev->type, type);
 468         cdev->ops = ops;
 469         cdev->device.class = &thermal_class;
 470         cdev->devdata = devdata;
 471         sprintf(cdev->device.bus_id, "cooling_device%d", cdev->id);
 472         result = device_register(&cdev->device);
 473         if (result) {
 474                 release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
 475                 kfree(cdev);
 476                 return NULL;
 477         }
 478
 479         /* sys I/F */
 480         if (type) {
 481                 result = device_create_file(&cdev->device, &dev_attr_cdev_type);
 482                 if (result)
 483                         goto unregister;
 484         }
 485
 486         result = device_create_file(&cdev->device, &dev_attr_max_state);
 487         if (result)
 488                 goto unregister;
 489
 490         result = device_create_file(&cdev->device, &dev_attr_cur_state);
 491         if (result)
 492                 goto unregister;
 493
 494         mutex_lock(&thermal_list_lock);
 495         list_add(&cdev->node, &thermal_cdev_list);
 496         list_for_each_entry(pos, &thermal_tz_list, node) {
 497                 if (!pos->ops->bind)
 498                         continue;
 499                 result = pos->ops->bind(pos, cdev);
 500                 if (result)
 501                         break;
 502
 503         }
 504         mutex_unlock(&thermal_list_lock);
 505
 506         if (!result)
 507                 return cdev;
 508
 509       unregister:
 510         release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
 511         device_unregister(&cdev->device);
 512         return NULL;
 513 }
 514
 515 EXPORT_SYMBOL(thermal_cooling_device_register);
 516
 517 /**
 518  * thermal_cooling_device_unregister - removes the registered thermal cooling device
 519  * @cdev:       the thermal cooling device to remove.
 520  *
 521  * thermal_cooling_device_unregister() must be called when the device is no
 522  * longer needed.
 523  */
 524 void thermal_cooling_device_unregister(struct
 525                                        thermal_cooling_device
 526                                        *cdev)
 527 {
 528         struct thermal_zone_device *tz;
 529         struct thermal_cooling_device *pos = NULL;
 530
 531         if (!cdev)
 532                 return;
 533
 534         mutex_lock(&thermal_list_lock);
 535         list_for_each_entry(pos, &thermal_cdev_list, node)
 536             if (pos == cdev)
 537                 break;
 538         if (pos != cdev) {
 539                 /* thermal cooling device not found */
 540                 mutex_unlock(&thermal_list_lock);
 541                 return;
 542         }
 543         list_del(&cdev->node);
 544         list_for_each_entry(tz, &thermal_tz_list, node) {
 545                 if (!tz->ops->unbind)
 546                         continue;
 547                 tz->ops->unbind(tz, cdev);
 548         }
 549         mutex_unlock(&thermal_list_lock);
 550         if (cdev->type[0])
 551                 device_remove_file(&cdev->device, &dev_attr_cdev_type);
 552         device_remove_file(&cdev->device, &dev_attr_max_state);
 553         device_remove_file(&cdev->device, &dev_attr_cur_state);
 554
 555         release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id);
 556         device_unregister(&cdev->device);
 557         return;
 558 }
 559
 560 EXPORT_SYMBOL(thermal_cooling_device_unregister);
 561
 562 /**
 563  * thermal_zone_device_register - register a new thermal zone device
 564  * @type:       the thermal zone device type
 565  * @trips:      the number of trip points the thermal zone support
 566  * @devdata:    private device data
 567  * @ops:        standard thermal zone device callbacks
 568  *
 569  * thermal_zone_device_unregister() must be called when the device is no
 570  * longer needed.
 571  */
 572 struct thermal_zone_device *thermal_zone_device_register(char *type,
 573                                                          int trips,
 574                                                          void *devdata, struct
 575                                                          thermal_zone_device_ops
 576                                                          *ops)
 577 {
 578         struct thermal_zone_device *tz;
 579         struct thermal_cooling_device *pos;
 580         int result;
 581         int count;
 582
 583         if (strlen(type) >= THERMAL_NAME_LENGTH)
 584                 return NULL;
 585
 586         if (trips > THERMAL_MAX_TRIPS || trips < 0)
 587                 return NULL;
 588
 589         if (!ops || !ops->get_temp)
 590                 return NULL;
 591
 592         tz = kzalloc(sizeof(struct thermal_zone_device), GFP_KERNEL);
 593         if (!tz)
 594                 return NULL;
 595
 596         INIT_LIST_HEAD(&tz->cooling_devices);
 597         idr_init(&tz->idr);
 598         mutex_init(&tz->lock);
 599         result = get_idr(&thermal_tz_idr, &thermal_idr_lock, &tz->id);
 600         if (result) {
 601                 kfree(tz);
 602                 return NULL;
 603         }
 604
 605         strcpy(tz->type, type);
 606         tz->ops = ops;
 607         tz->device.class = &thermal_class;
 608         tz->devdata = devdata;
 609         tz->trips = trips;
 610         sprintf(tz->device.bus_id, "thermal_zone%d", tz->id);
 611         result = device_register(&tz->device);
 612         if (result) {
 613                 release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
 614                 kfree(tz);
 615                 return NULL;
 616         }
 617
 618         /* sys I/F */
 619         if (type) {
 620                 result = device_create_file(&tz->device, &dev_attr_type);
 621                 if (result)
 622                         goto unregister;
 623         }
 624
 625         result = device_create_file(&tz->device, &dev_attr_temp);
 626         if (result)
 627                 goto unregister;
 628
 629         if (ops->get_mode) {
 630                 result = device_create_file(&tz->device, &dev_attr_mode);
 631                 if (result)
 632                         goto unregister;
 633         }
 634
 635         for (count = 0; count < trips; count++) {
 636                 TRIP_POINT_ATTR_ADD(&tz->device, count, result);
 637                 if (result)
 638                         goto unregister;
 639         }
 640
 641         mutex_lock(&thermal_list_lock);
 642         list_add_tail(&tz->node, &thermal_tz_list);
 643         if (ops->bind)
 644                 list_for_each_entry(pos, &thermal_cdev_list, node) {
 645                 result = ops->bind(tz, pos);
 646                 if (result)
 647                         break;
 648                 }
 649         mutex_unlock(&thermal_list_lock);
 650
 651         if (!result)
 652                 return tz;
 653
 654       unregister:
 655         release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
 656         device_unregister(&tz->device);
 657         return NULL;
 658 }
 659
 660 EXPORT_SYMBOL(thermal_zone_device_register);
 661
 662 /**
 663  * thermal_device_unregister - removes the registered thermal zone device
 664  * @tz: the thermal zone device to remove
 665  */
 666 void thermal_zone_device_unregister(struct thermal_zone_device *tz)
 667 {
 668         struct thermal_cooling_device *cdev;
 669         struct thermal_zone_device *pos = NULL;
 670         int count;
 671
 672         if (!tz)
 673                 return;
 674
 675         mutex_lock(&thermal_list_lock);
 676         list_for_each_entry(pos, &thermal_tz_list, node)
 677             if (pos == tz)
 678                 break;
 679         if (pos != tz) {
 680                 /* thermal zone device not found */
 681                 mutex_unlock(&thermal_list_lock);
 682                 return;
 683         }
 684         list_del(&tz->node);
 685         if (tz->ops->unbind)
 686                 list_for_each_entry(cdev, &thermal_cdev_list, node)
 687                     tz->ops->unbind(tz, cdev);
 688         mutex_unlock(&thermal_list_lock);
 689
 690         if (tz->type[0])
 691                 device_remove_file(&tz->device, &dev_attr_type);
 692         device_remove_file(&tz->device, &dev_attr_temp);
 693         if (tz->ops->get_mode)
 694                 device_remove_file(&tz->device, &dev_attr_mode);
 695
 696         for (count = 0; count < tz->trips; count++)
 697                 TRIP_POINT_ATTR_REMOVE(&tz->device, count);
 698
 699         release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id);
 700         idr_destroy(&tz->idr);
 701         mutex_destroy(&tz->lock);
 702         device_unregister(&tz->device);
 703         return;
 704 }
 705
 706 EXPORT_SYMBOL(thermal_zone_device_unregister);
 707
 708 static int __init thermal_init(void)
 709 {
 710         int result = 0;
 711
 712         result = class_register(&thermal_class);
 713         if (result) {
 714                 idr_destroy(&thermal_tz_idr);
 715                 idr_destroy(&thermal_cdev_idr);
 716                 mutex_destroy(&thermal_idr_lock);
 717                 mutex_destroy(&thermal_list_lock);
 718         }
 719         return result;
 720 }
 721
 722 static void __exit thermal_exit(void)
 723 {
 724         class_unregister(&thermal_class);
 725         idr_destroy(&thermal_tz_idr);
 726         idr_destroy(&thermal_cdev_idr);
 727         mutex_destroy(&thermal_idr_lock);
 728         mutex_destroy(&thermal_list_lock);
 729 }
 730
 731 subsys_initcall(thermal_init);
 732 module_exit(thermal_exit);