drivers/acpi/thermal.c

   1 /*
   2  *  acpi_thermal.c - ACPI Thermal Zone Driver ($Revision: 41 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  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  *  This driver fully implements the ACPI thermal policy as described in the
  26  *  ACPI 2.0 Specification.
  27  *
  28  *  TBD: 1. Implement passive cooling hysteresis.
  29  *       2. Enhance passive cooling (CPU) states/limit interface to support
  30  *          concepts of 'multiple limiters', upper/lower limits, etc.
  31  *
  32  */
  33
  34 #include <linux/kernel.h>
  35 #include <linux/module.h>
  36 #include <linux/dmi.h>
  37 #include <linux/init.h>
  38 #include <linux/slab.h>
  39 #include <linux/types.h>
  40 #include <linux/jiffies.h>
  41 #include <linux/kmod.h>
  42 #include <linux/reboot.h>
  43 #include <linux/device.h>
  44 #include <asm/uaccess.h>
  45 #include <linux/thermal.h>
  46 #include <acpi/acpi_bus.h>
  47 #include <acpi/acpi_drivers.h>
  48
  49 #define PREFIX "ACPI: "
  50
  51 #define ACPI_THERMAL_CLASS              "thermal_zone"
  52 #define ACPI_THERMAL_DEVICE_NAME        "Thermal Zone"
  53 #define ACPI_THERMAL_FILE_STATE         "state"
  54 #define ACPI_THERMAL_FILE_TEMPERATURE   "temperature"
  55 #define ACPI_THERMAL_FILE_TRIP_POINTS   "trip_points"
  56 #define ACPI_THERMAL_FILE_COOLING_MODE  "cooling_mode"
  57 #define ACPI_THERMAL_FILE_POLLING_FREQ  "polling_frequency"
  58 #define ACPI_THERMAL_NOTIFY_TEMPERATURE 0x80
  59 #define ACPI_THERMAL_NOTIFY_THRESHOLDS  0x81
  60 #define ACPI_THERMAL_NOTIFY_DEVICES     0x82
  61 #define ACPI_THERMAL_NOTIFY_CRITICAL    0xF0
  62 #define ACPI_THERMAL_NOTIFY_HOT         0xF1
  63 #define ACPI_THERMAL_MODE_ACTIVE        0x00
  64
  65 #define ACPI_THERMAL_MAX_ACTIVE 10
  66 #define ACPI_THERMAL_MAX_LIMIT_STR_LEN 65
  67
  68 #define _COMPONENT              ACPI_THERMAL_COMPONENT
  69 ACPI_MODULE_NAME("thermal");
  70
  71 MODULE_AUTHOR("Paul Diefenbaugh");
  72 MODULE_DESCRIPTION("ACPI Thermal Zone Driver");
  73 MODULE_LICENSE("GPL");
  74
  75 static int act;
  76 module_param(act, int, 0644);
  77 MODULE_PARM_DESC(act, "Disable or override all lowest active trip points.");
  78
  79 static int crt;
  80 module_param(crt, int, 0644);
  81 MODULE_PARM_DESC(crt, "Disable or lower all critical trip points.");
  82
  83 static int tzp;
  84 module_param(tzp, int, 0444);
  85 MODULE_PARM_DESC(tzp, "Thermal zone polling frequency, in 1/10 seconds.");
  86
  87 static int nocrt;
  88 module_param(nocrt, int, 0);
  89 MODULE_PARM_DESC(nocrt, "Set to take no action upon ACPI thermal zone critical trips points.");
  90
  91 static int off;
  92 module_param(off, int, 0);
  93 MODULE_PARM_DESC(off, "Set to disable ACPI thermal support.");
  94
  95 static int psv;
  96 module_param(psv, int, 0644);
  97 MODULE_PARM_DESC(psv, "Disable or override all passive trip points.");
  98
  99 static int acpi_thermal_add(struct acpi_device *device);
 100 static int acpi_thermal_remove(struct acpi_device *device, int type);
 101 static void acpi_thermal_notify(struct acpi_device *device, u32 event);
 102
 103 static const struct acpi_device_id  thermal_device_ids[] = {
 104         {ACPI_THERMAL_HID, 0},
 105         {"", 0},
 106 };
 107 MODULE_DEVICE_TABLE(acpi, thermal_device_ids);
 108
 109 #ifdef CONFIG_PM_SLEEP
 110 static int acpi_thermal_resume(struct device *dev);
 111 #endif
 112 static SIMPLE_DEV_PM_OPS(acpi_thermal_pm, NULL, acpi_thermal_resume);
 113
 114 static struct acpi_driver acpi_thermal_driver = {
 115         .name = "thermal",
 116         .class = ACPI_THERMAL_CLASS,
 117         .ids = thermal_device_ids,
 118         .ops = {
 119                 .add = acpi_thermal_add,
 120                 .remove = acpi_thermal_remove,
 121                 .notify = acpi_thermal_notify,
 122                 },
 123         .drv.pm = &acpi_thermal_pm,
 124 };
 125
 126 struct acpi_thermal_state {
 127         u8 critical:1;
 128         u8 hot:1;
 129         u8 passive:1;
 130         u8 active:1;
 131         u8 reserved:4;
 132         int active_index;
 133 };
 134
 135 struct acpi_thermal_state_flags {
 136         u8 valid:1;
 137         u8 enabled:1;
 138         u8 reserved:6;
 139 };
 140
 141 struct acpi_thermal_critical {
 142         struct acpi_thermal_state_flags flags;
 143         unsigned long temperature;
 144 };
 145
 146 struct acpi_thermal_hot {
 147         struct acpi_thermal_state_flags flags;
 148         unsigned long temperature;
 149 };
 150
 151 struct acpi_thermal_passive {
 152         struct acpi_thermal_state_flags flags;
 153         unsigned long temperature;
 154         unsigned long tc1;
 155         unsigned long tc2;
 156         unsigned long tsp;
 157         struct acpi_handle_list devices;
 158 };
 159
 160 struct acpi_thermal_active {
 161         struct acpi_thermal_state_flags flags;
 162         unsigned long temperature;
 163         struct acpi_handle_list devices;
 164 };
 165
 166 struct acpi_thermal_trips {
 167         struct acpi_thermal_critical critical;
 168         struct acpi_thermal_hot hot;
 169         struct acpi_thermal_passive passive;
 170         struct acpi_thermal_active active[ACPI_THERMAL_MAX_ACTIVE];
 171 };
 172
 173 struct acpi_thermal_flags {
 174         u8 cooling_mode:1;      /* _SCP */
 175         u8 devices:1;           /* _TZD */
 176         u8 reserved:6;
 177 };
 178
 179 struct acpi_thermal {
 180         struct acpi_device * device;
 181         acpi_bus_id name;
 182         unsigned long temperature;
 183         unsigned long last_temperature;
 184         unsigned long polling_frequency;
 185         volatile u8 zombie;
 186         struct acpi_thermal_flags flags;
 187         struct acpi_thermal_state state;
 188         struct acpi_thermal_trips trips;
 189         struct acpi_handle_list devices;
 190         struct thermal_zone_device *thermal_zone;
 191         int tz_enabled;
 192         int kelvin_offset;
 193         struct mutex lock;
 194 };
 195
 196 /* --------------------------------------------------------------------------
 197                              Thermal Zone Management
 198    -------------------------------------------------------------------------- */
 199
 200 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
 201 {
 202         acpi_status status = AE_OK;
 203         unsigned long long tmp;
 204
 205         if (!tz)
 206                 return -EINVAL;
 207
 208         tz->last_temperature = tz->temperature;
 209
 210         status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
 211         if (ACPI_FAILURE(status))
 212                 return -ENODEV;
 213
 214         tz->temperature = tmp;
 215         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Temperature is %lu dK\n",
 216                           tz->temperature));
 217
 218         return 0;
 219 }
 220
 221 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
 222 {
 223         acpi_status status = AE_OK;
 224         unsigned long long tmp;
 225
 226         if (!tz)
 227                 return -EINVAL;
 228
 229         status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
 230         if (ACPI_FAILURE(status))
 231                 return -ENODEV;
 232
 233         tz->polling_frequency = tmp;
 234         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Polling frequency is %lu dS\n",
 235                           tz->polling_frequency));
 236
 237         return 0;
 238 }
 239
 240 static int acpi_thermal_set_cooling_mode(struct acpi_thermal *tz, int mode)
 241 {
 242         acpi_status status = AE_OK;
 243         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 244         struct acpi_object_list arg_list = { 1, &arg0 };
 245         acpi_handle handle = NULL;
 246
 247
 248         if (!tz)
 249                 return -EINVAL;
 250
 251         status = acpi_get_handle(tz->device->handle, "_SCP", &handle);
 252         if (ACPI_FAILURE(status)) {
 253                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "_SCP not present\n"));
 254                 return -ENODEV;
 255         }
 256
 257         arg0.integer.value = mode;
 258
 259         status = acpi_evaluate_object(handle, NULL, &arg_list, NULL);
 260         if (ACPI_FAILURE(status))
 261                 return -ENODEV;
 262
 263         return 0;
 264 }
 265
 266 #define ACPI_TRIPS_CRITICAL     0x01
 267 #define ACPI_TRIPS_HOT          0x02
 268 #define ACPI_TRIPS_PASSIVE      0x04
 269 #define ACPI_TRIPS_ACTIVE       0x08
 270 #define ACPI_TRIPS_DEVICES      0x10
 271
 272 #define ACPI_TRIPS_REFRESH_THRESHOLDS   (ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
 273 #define ACPI_TRIPS_REFRESH_DEVICES      ACPI_TRIPS_DEVICES
 274
 275 #define ACPI_TRIPS_INIT      (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT |    \
 276                               ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE |  \
 277                               ACPI_TRIPS_DEVICES)
 278
 279 /*
 280  * This exception is thrown out in two cases:
 281  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
 282  *   when re-evaluating the AML code.
 283  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
 284  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
 285  */
 286 #define ACPI_THERMAL_TRIPS_EXCEPTION(flags, str)        \
 287 do {    \
 288         if (flags != ACPI_TRIPS_INIT)   \
 289                 ACPI_EXCEPTION((AE_INFO, AE_ERROR,      \
 290                 "ACPI thermal trip point %s changed\n"  \
 291                 "Please send acpidump to linux-acpi@vger.kernel.org\n", str)); \
 292 } while (0)
 293
 294 static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 295 {
 296         acpi_status status = AE_OK;
 297         unsigned long long tmp;
 298         struct acpi_handle_list devices;
 299         int valid = 0;
 300         int i;
 301
 302         /* Critical Shutdown */
 303         if (flag & ACPI_TRIPS_CRITICAL) {
 304                 status = acpi_evaluate_integer(tz->device->handle,
 305                                 "_CRT", NULL, &tmp);
 306                 tz->trips.critical.temperature = tmp;
 307                 /*
 308                  * Treat freezing temperatures as invalid as well; some
 309                  * BIOSes return really low values and cause reboots at startup.
 310                  * Below zero (Celsius) values clearly aren't right for sure..
 311                  * ... so lets discard those as invalid.
 312                  */
 313                 if (ACPI_FAILURE(status)) {
 314                         tz->trips.critical.flags.valid = 0;
 315                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 316                                           "No critical threshold\n"));
 317                 } else if (tmp <= 2732) {
 318                         printk(KERN_WARNING FW_BUG "Invalid critical threshold "
 319                                "(%llu)\n", tmp);
 320                         tz->trips.critical.flags.valid = 0;
 321                 } else {
 322                         tz->trips.critical.flags.valid = 1;
 323                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 324                                           "Found critical threshold [%lu]\n",
 325                                           tz->trips.critical.temperature));
 326                 }
 327                 if (tz->trips.critical.flags.valid == 1) {
 328                         if (crt == -1) {
 329                                 tz->trips.critical.flags.valid = 0;
 330                         } else if (crt > 0) {
 331                                 unsigned long crt_k = CELSIUS_TO_KELVIN(crt);
 332                                 /*
 333                                  * Allow override critical threshold
 334                                  */
 335                                 if (crt_k > tz->trips.critical.temperature)
 336                                         printk(KERN_WARNING PREFIX
 337                                                 "Critical threshold %d C\n", crt);
 338                                 tz->trips.critical.temperature = crt_k;
 339                         }
 340                 }
 341         }
 342
 343         /* Critical Sleep (optional) */
 344         if (flag & ACPI_TRIPS_HOT) {
 345                 status = acpi_evaluate_integer(tz->device->handle,
 346                                 "_HOT", NULL, &tmp);
 347                 if (ACPI_FAILURE(status)) {
 348                         tz->trips.hot.flags.valid = 0;
 349                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 350                                         "No hot threshold\n"));
 351                 } else {
 352                         tz->trips.hot.temperature = tmp;
 353                         tz->trips.hot.flags.valid = 1;
 354                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 355                                         "Found hot threshold [%lu]\n",
 356                                         tz->trips.critical.temperature));
 357                 }
 358         }
 359
 360         /* Passive (optional) */
 361         if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.flags.valid) ||
 362                 (flag == ACPI_TRIPS_INIT)) {
 363                 valid = tz->trips.passive.flags.valid;
 364                 if (psv == -1) {
 365                         status = AE_SUPPORT;
 366                 } else if (psv > 0) {
 367                         tmp = CELSIUS_TO_KELVIN(psv);
 368                         status = AE_OK;
 369                 } else {
 370                         status = acpi_evaluate_integer(tz->device->handle,
 371                                 "_PSV", NULL, &tmp);
 372                 }
 373
 374                 if (ACPI_FAILURE(status))
 375                         tz->trips.passive.flags.valid = 0;
 376                 else {
 377                         tz->trips.passive.temperature = tmp;
 378                         tz->trips.passive.flags.valid = 1;
 379                         if (flag == ACPI_TRIPS_INIT) {
 380                                 status = acpi_evaluate_integer(
 381                                                 tz->device->handle, "_TC1",
 382                                                 NULL, &tmp);
 383                                 if (ACPI_FAILURE(status))
 384                                         tz->trips.passive.flags.valid = 0;
 385                                 else
 386                                         tz->trips.passive.tc1 = tmp;
 387                                 status = acpi_evaluate_integer(
 388                                                 tz->device->handle, "_TC2",
 389                                                 NULL, &tmp);
 390                                 if (ACPI_FAILURE(status))
 391                                         tz->trips.passive.flags.valid = 0;
 392                                 else
 393                                         tz->trips.passive.tc2 = tmp;
 394                                 status = acpi_evaluate_integer(
 395                                                 tz->device->handle, "_TSP",
 396                                                 NULL, &tmp);
 397                                 if (ACPI_FAILURE(status))
 398                                         tz->trips.passive.flags.valid = 0;
 399                                 else
 400                                         tz->trips.passive.tsp = tmp;
 401                         }
 402                 }
 403         }
 404         if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.flags.valid) {
 405                 memset(&devices, 0, sizeof(struct acpi_handle_list));
 406                 status = acpi_evaluate_reference(tz->device->handle, "_PSL",
 407                                                         NULL, &devices);
 408                 if (ACPI_FAILURE(status)) {
 409                         printk(KERN_WARNING PREFIX
 410                                 "Invalid passive threshold\n");
 411                         tz->trips.passive.flags.valid = 0;
 412                 }
 413                 else
 414                         tz->trips.passive.flags.valid = 1;
 415
 416                 if (memcmp(&tz->trips.passive.devices, &devices,
 417                                 sizeof(struct acpi_handle_list))) {
 418                         memcpy(&tz->trips.passive.devices, &devices,
 419                                 sizeof(struct acpi_handle_list));
 420                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 421                 }
 422         }
 423         if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
 424                 if (valid != tz->trips.passive.flags.valid)
 425                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 426         }
 427
 428         /* Active (optional) */
 429         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 430                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
 431                 valid = tz->trips.active[i].flags.valid;
 432
 433                 if (act == -1)
 434                         break; /* disable all active trip points */
 435
 436                 if ((flag == ACPI_TRIPS_INIT) || ((flag & ACPI_TRIPS_ACTIVE) &&
 437                         tz->trips.active[i].flags.valid)) {
 438                         status = acpi_evaluate_integer(tz->device->handle,
 439                                                         name, NULL, &tmp);
 440                         if (ACPI_FAILURE(status)) {
 441                                 tz->trips.active[i].flags.valid = 0;
 442                                 if (i == 0)
 443                                         break;
 444                                 if (act <= 0)
 445                                         break;
 446                                 if (i == 1)
 447                                         tz->trips.active[0].temperature =
 448                                                 CELSIUS_TO_KELVIN(act);
 449                                 else
 450                                         /*
 451                                          * Don't allow override higher than
 452                                          * the next higher trip point
 453                                          */
 454                                         tz->trips.active[i - 1].temperature =
 455                                                 (tz->trips.active[i - 2].temperature <
 456                                                 CELSIUS_TO_KELVIN(act) ?
 457                                                 tz->trips.active[i - 2].temperature :
 458                                                 CELSIUS_TO_KELVIN(act));
 459                                 break;
 460                         } else {
 461                                 tz->trips.active[i].temperature = tmp;
 462                                 tz->trips.active[i].flags.valid = 1;
 463                         }
 464                 }
 465
 466                 name[2] = 'L';
 467                 if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].flags.valid ) {
 468                         memset(&devices, 0, sizeof(struct acpi_handle_list));
 469                         status = acpi_evaluate_reference(tz->device->handle,
 470                                                 name, NULL, &devices);
 471                         if (ACPI_FAILURE(status)) {
 472                                 printk(KERN_WARNING PREFIX
 473                                         "Invalid active%d threshold\n", i);
 474                                 tz->trips.active[i].flags.valid = 0;
 475                         }
 476                         else
 477                                 tz->trips.active[i].flags.valid = 1;
 478
 479                         if (memcmp(&tz->trips.active[i].devices, &devices,
 480                                         sizeof(struct acpi_handle_list))) {
 481                                 memcpy(&tz->trips.active[i].devices, &devices,
 482                                         sizeof(struct acpi_handle_list));
 483                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 484                         }
 485                 }
 486                 if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
 487                         if (valid != tz->trips.active[i].flags.valid)
 488                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 489
 490                 if (!tz->trips.active[i].flags.valid)
 491                         break;
 492         }
 493
 494         if (flag & ACPI_TRIPS_DEVICES) {
 495                 memset(&devices, 0, sizeof(struct acpi_handle_list));
 496                 status = acpi_evaluate_reference(tz->device->handle, "_TZD",
 497                                                 NULL, &devices);
 498                 if (memcmp(&tz->devices, &devices,
 499                                 sizeof(struct acpi_handle_list))) {
 500                         memcpy(&tz->devices, &devices,
 501                                 sizeof(struct acpi_handle_list));
 502                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 503                 }
 504         }
 505
 506         return 0;
 507 }
 508
 509 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
 510 {
 511         int i, valid, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
 512
 513         if (ret)
 514                 return ret;
 515
 516         valid = tz->trips.critical.flags.valid |
 517                 tz->trips.hot.flags.valid |
 518                 tz->trips.passive.flags.valid;
 519
 520         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
 521                 valid |= tz->trips.active[i].flags.valid;
 522
 523         if (!valid) {
 524                 printk(KERN_WARNING FW_BUG "No valid trip found\n");
 525                 return -ENODEV;
 526         }
 527         return 0;
 528 }
 529
 530 static void acpi_thermal_check(void *data)
 531 {
 532         struct acpi_thermal *tz = data;
 533
 534         thermal_zone_device_update(tz->thermal_zone);
 535 }
 536
 537 /* sys I/F for generic thermal sysfs support */
 538 #define KELVIN_TO_MILLICELSIUS(t, off) (((t) - (off)) * 100)
 539
 540 static int thermal_get_temp(struct thermal_zone_device *thermal,
 541                             unsigned long *temp)
 542 {
 543         struct acpi_thermal *tz = thermal->devdata;
 544         int result;
 545
 546         if (!tz)
 547                 return -EINVAL;
 548
 549         result = acpi_thermal_get_temperature(tz);
 550         if (result)
 551                 return result;
 552
 553         *temp = KELVIN_TO_MILLICELSIUS(tz->temperature, tz->kelvin_offset);
 554         return 0;
 555 }
 556
 557 static int thermal_get_mode(struct thermal_zone_device *thermal,
 558                                 enum thermal_device_mode *mode)
 559 {
 560         struct acpi_thermal *tz = thermal->devdata;
 561
 562         if (!tz)
 563                 return -EINVAL;
 564
 565         *mode = tz->tz_enabled ? THERMAL_DEVICE_ENABLED :
 566                 THERMAL_DEVICE_DISABLED;
 567
 568         return 0;
 569 }
 570
 571 static int thermal_set_mode(struct thermal_zone_device *thermal,
 572                                 enum thermal_device_mode mode)
 573 {
 574         struct acpi_thermal *tz = thermal->devdata;
 575         int enable;
 576
 577         if (!tz)
 578                 return -EINVAL;
 579
 580         /*
 581          * enable/disable thermal management from ACPI thermal driver
 582          */
 583         if (mode == THERMAL_DEVICE_ENABLED)
 584                 enable = 1;
 585         else if (mode == THERMAL_DEVICE_DISABLED)
 586                 enable = 0;
 587         else
 588                 return -EINVAL;
 589
 590         if (enable != tz->tz_enabled) {
 591                 tz->tz_enabled = enable;
 592                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 593                         "%s kernel ACPI thermal control\n",
 594                         tz->tz_enabled ? "Enable" : "Disable"));
 595                 acpi_thermal_check(tz);
 596         }
 597         return 0;
 598 }
 599
 600 static int thermal_get_trip_type(struct thermal_zone_device *thermal,
 601                                  int trip, enum thermal_trip_type *type)
 602 {
 603         struct acpi_thermal *tz = thermal->devdata;
 604         int i;
 605
 606         if (!tz || trip < 0)
 607                 return -EINVAL;
 608
 609         if (tz->trips.critical.flags.valid) {
 610                 if (!trip) {
 611                         *type = THERMAL_TRIP_CRITICAL;
 612                         return 0;
 613                 }
 614                 trip--;
 615         }
 616
 617         if (tz->trips.hot.flags.valid) {
 618                 if (!trip) {
 619                         *type = THERMAL_TRIP_HOT;
 620                         return 0;
 621                 }
 622                 trip--;
 623         }
 624
 625         if (tz->trips.passive.flags.valid) {
 626                 if (!trip) {
 627                         *type = THERMAL_TRIP_PASSIVE;
 628                         return 0;
 629                 }
 630                 trip--;
 631         }
 632
 633         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 634                 tz->trips.active[i].flags.valid; i++) {
 635                 if (!trip) {
 636                         *type = THERMAL_TRIP_ACTIVE;
 637                         return 0;
 638                 }
 639                 trip--;
 640         }
 641
 642         return -EINVAL;
 643 }
 644
 645 static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
 646                                  int trip, unsigned long *temp)
 647 {
 648         struct acpi_thermal *tz = thermal->devdata;
 649         int i;
 650
 651         if (!tz || trip < 0)
 652                 return -EINVAL;
 653
 654         if (tz->trips.critical.flags.valid) {
 655                 if (!trip) {
 656                         *temp = KELVIN_TO_MILLICELSIUS(
 657                                 tz->trips.critical.temperature,
 658                                 tz->kelvin_offset);
 659                         return 0;
 660                 }
 661                 trip--;
 662         }
 663
 664         if (tz->trips.hot.flags.valid) {
 665                 if (!trip) {
 666                         *temp = KELVIN_TO_MILLICELSIUS(
 667                                 tz->trips.hot.temperature,
 668                                 tz->kelvin_offset);
 669                         return 0;
 670                 }
 671                 trip--;
 672         }
 673
 674         if (tz->trips.passive.flags.valid) {
 675                 if (!trip) {
 676                         *temp = KELVIN_TO_MILLICELSIUS(
 677                                 tz->trips.passive.temperature,
 678                                 tz->kelvin_offset);
 679                         return 0;
 680                 }
 681                 trip--;
 682         }
 683
 684         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 685                 tz->trips.active[i].flags.valid; i++) {
 686                 if (!trip) {
 687                         *temp = KELVIN_TO_MILLICELSIUS(
 688                                 tz->trips.active[i].temperature,
 689                                 tz->kelvin_offset);
 690                         return 0;
 691                 }
 692                 trip--;
 693         }
 694
 695         return -EINVAL;
 696 }
 697
 698 static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
 699                                 unsigned long *temperature) {
 700         struct acpi_thermal *tz = thermal->devdata;
 701
 702         if (tz->trips.critical.flags.valid) {
 703                 *temperature = KELVIN_TO_MILLICELSIUS(
 704                                 tz->trips.critical.temperature,
 705                                 tz->kelvin_offset);
 706                 return 0;
 707         } else
 708                 return -EINVAL;
 709 }
 710
 711 static int thermal_get_trend(struct thermal_zone_device *thermal,
 712                                 int trip, enum thermal_trend *trend)
 713 {
 714         struct acpi_thermal *tz = thermal->devdata;
 715         enum thermal_trip_type type;
 716         int i;
 717
 718         if (thermal_get_trip_type(thermal, trip, &type))
 719                 return -EINVAL;
 720
 721         if (type == THERMAL_TRIP_ACTIVE) {
 722                 /* aggressive active cooling */
 723                 *trend = THERMAL_TREND_RAISING;
 724                 return 0;
 725         }
 726
 727         /*
 728          * tz->temperature has already been updated by generic thermal layer,
 729          * before this callback being invoked
 730          */
 731         i = (tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature))
 732                 + (tz->trips.passive.tc2
 733                 * (tz->temperature - tz->trips.passive.temperature));
 734
 735         if (i > 0)
 736                 *trend = THERMAL_TREND_RAISING;
 737         else if (i < 0)
 738                 *trend = THERMAL_TREND_DROPPING;
 739         else
 740                 *trend = THERMAL_TREND_STABLE;
 741         return 0;
 742 }
 743
 744
 745 static int thermal_notify(struct thermal_zone_device *thermal, int trip,
 746                            enum thermal_trip_type trip_type)
 747 {
 748         u8 type = 0;
 749         struct acpi_thermal *tz = thermal->devdata;
 750
 751         if (trip_type == THERMAL_TRIP_CRITICAL)
 752                 type = ACPI_THERMAL_NOTIFY_CRITICAL;
 753         else if (trip_type == THERMAL_TRIP_HOT)
 754                 type = ACPI_THERMAL_NOTIFY_HOT;
 755         else
 756                 return 0;
 757
 758         acpi_bus_generate_proc_event(tz->device, type, 1);
 759         acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
 760                                         dev_name(&tz->device->dev), type, 1);
 761
 762         if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)
 763                 return 1;
 764
 765         return 0;
 766 }
 767
 768 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
 769                                         struct thermal_cooling_device *cdev,
 770                                         bool bind)
 771 {
 772         struct acpi_device *device = cdev->devdata;
 773         struct acpi_thermal *tz = thermal->devdata;
 774         struct acpi_device *dev;
 775         acpi_status status;
 776         acpi_handle handle;
 777         int i;
 778         int j;
 779         int trip = -1;
 780         int result = 0;
 781
 782         if (tz->trips.critical.flags.valid)
 783                 trip++;
 784
 785         if (tz->trips.hot.flags.valid)
 786                 trip++;
 787
 788         if (tz->trips.passive.flags.valid) {
 789                 trip++;
 790                 for (i = 0; i < tz->trips.passive.devices.count;
 791                     i++) {
 792                         handle = tz->trips.passive.devices.handles[i];
 793                         status = acpi_bus_get_device(handle, &dev);
 794                         if (ACPI_FAILURE(status) || dev != device)
 795                                 continue;
 796                         if (bind)
 797                                 result =
 798                                         thermal_zone_bind_cooling_device
 799                                         (thermal, trip, cdev,
 800                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT);
 801                         else
 802                                 result =
 803                                         thermal_zone_unbind_cooling_device
 804                                         (thermal, trip, cdev);
 805                         if (result)
 806                                 goto failed;
 807                 }
 808         }
 809
 810         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 811                 if (!tz->trips.active[i].flags.valid)
 812                         break;
 813                 trip++;
 814                 for (j = 0;
 815                     j < tz->trips.active[i].devices.count;
 816                     j++) {
 817                         handle = tz->trips.active[i].devices.handles[j];
 818                         status = acpi_bus_get_device(handle, &dev);
 819                         if (ACPI_FAILURE(status) || dev != device)
 820                                 continue;
 821                         if (bind)
 822                                 result = thermal_zone_bind_cooling_device
 823                                         (thermal, trip, cdev,
 824                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT);
 825                         else
 826                                 result = thermal_zone_unbind_cooling_device
 827                                         (thermal, trip, cdev);
 828                         if (result)
 829                                 goto failed;
 830                 }
 831         }
 832
 833         for (i = 0; i < tz->devices.count; i++) {
 834                 handle = tz->devices.handles[i];
 835                 status = acpi_bus_get_device(handle, &dev);
 836                 if (ACPI_SUCCESS(status) && (dev == device)) {
 837                         if (bind)
 838                                 result = thermal_zone_bind_cooling_device
 839                                                 (thermal, -1, cdev,
 840                                                  THERMAL_NO_LIMIT,
 841                                                  THERMAL_NO_LIMIT);
 842                         else
 843                                 result = thermal_zone_unbind_cooling_device
 844                                                 (thermal, -1, cdev);
 845                         if (result)
 846                                 goto failed;
 847                 }
 848         }
 849
 850 failed:
 851         return result;
 852 }
 853
 854 static int
 855 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
 856                                         struct thermal_cooling_device *cdev)
 857 {
 858         return acpi_thermal_cooling_device_cb(thermal, cdev, true);
 859 }
 860
 861 static int
 862 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
 863                                         struct thermal_cooling_device *cdev)
 864 {
 865         return acpi_thermal_cooling_device_cb(thermal, cdev, false);
 866 }
 867
 868 static const struct thermal_zone_device_ops acpi_thermal_zone_ops = {
 869         .bind = acpi_thermal_bind_cooling_device,
 870         .unbind = acpi_thermal_unbind_cooling_device,
 871         .get_temp = thermal_get_temp,
 872         .get_mode = thermal_get_mode,
 873         .set_mode = thermal_set_mode,
 874         .get_trip_type = thermal_get_trip_type,
 875         .get_trip_temp = thermal_get_trip_temp,
 876         .get_crit_temp = thermal_get_crit_temp,
 877         .get_trend = thermal_get_trend,
 878         .notify = thermal_notify,
 879 };
 880
 881 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 882 {
 883         int trips = 0;
 884         int result;
 885         acpi_status status;
 886         int i;
 887
 888         if (tz->trips.critical.flags.valid)
 889                 trips++;
 890
 891         if (tz->trips.hot.flags.valid)
 892                 trips++;
 893
 894         if (tz->trips.passive.flags.valid)
 895                 trips++;
 896
 897         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 898                         tz->trips.active[i].flags.valid; i++, trips++);
 899
 900         if (tz->trips.passive.flags.valid)
 901                 tz->thermal_zone =
 902                         thermal_zone_device_register("acpitz", trips, 0, tz,
 903                                                 &acpi_thermal_zone_ops, NULL,
 904                                                      tz->trips.passive.tsp*100,
 905                                                      tz->polling_frequency*100);
 906         else
 907                 tz->thermal_zone =
 908                         thermal_zone_device_register("acpitz", trips, 0, tz,
 909                                                 &acpi_thermal_zone_ops, NULL,
 910                                                 0, tz->polling_frequency*100);
 911         if (IS_ERR(tz->thermal_zone))
 912                 return -ENODEV;
 913
 914         result = sysfs_create_link(&tz->device->dev.kobj,
 915                                    &tz->thermal_zone->device.kobj, "thermal_zone");
 916         if (result)
 917                 return result;
 918
 919         result = sysfs_create_link(&tz->thermal_zone->device.kobj,
 920                                    &tz->device->dev.kobj, "device");
 921         if (result)
 922                 return result;
 923
 924         status = acpi_attach_data(tz->device->handle,
 925                                   acpi_bus_private_data_handler,
 926                                   tz->thermal_zone);
 927         if (ACPI_FAILURE(status)) {
 928                 printk(KERN_ERR PREFIX
 929                                 "Error attaching device data\n");
 930                 return -ENODEV;
 931         }
 932
 933         tz->tz_enabled = 1;
 934
 935         dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
 936                  tz->thermal_zone->id);
 937         return 0;
 938 }
 939
 940 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
 941 {
 942         sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 943         sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
 944         thermal_zone_device_unregister(tz->thermal_zone);
 945         tz->thermal_zone = NULL;
 946         acpi_detach_data(tz->device->handle, acpi_bus_private_data_handler);
 947 }
 948
 949
 950 /* --------------------------------------------------------------------------
 951                                  Driver Interface
 952    -------------------------------------------------------------------------- */
 953
 954 static void acpi_thermal_notify(struct acpi_device *device, u32 event)
 955 {
 956         struct acpi_thermal *tz = acpi_driver_data(device);
 957
 958
 959         if (!tz)
 960                 return;
 961
 962         switch (event) {
 963         case ACPI_THERMAL_NOTIFY_TEMPERATURE:
 964                 acpi_thermal_check(tz);
 965                 break;
 966         case ACPI_THERMAL_NOTIFY_THRESHOLDS:
 967                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
 968                 acpi_thermal_check(tz);
 969                 acpi_bus_generate_proc_event(device, event, 0);
 970                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 971                                                   dev_name(&device->dev), event, 0);
 972                 break;
 973         case ACPI_THERMAL_NOTIFY_DEVICES:
 974                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
 975                 acpi_thermal_check(tz);
 976                 acpi_bus_generate_proc_event(device, event, 0);
 977                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 978                                                   dev_name(&device->dev), event, 0);
 979                 break;
 980         default:
 981                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 982                                   "Unsupported event [0x%x]\n", event));
 983                 break;
 984         }
 985 }
 986
 987 /*
 988  * On some platforms, the AML code has dependency about
 989  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
 990  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
 991  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
 992  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
 993  *    if _TMP has never been evaluated.
 994  *
 995  * As this dependency is totally transparent to OS, evaluate
 996  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
 997  * _TMP, before they are actually used.
 998  */
 999 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
1000 {
1001         acpi_handle handle = tz->device->handle;
1002         unsigned long long value;
1003         int i;
1004
1005         acpi_evaluate_integer(handle, "_CRT", NULL, &value);
1006         acpi_evaluate_integer(handle, "_HOT", NULL, &value);
1007         acpi_evaluate_integer(handle, "_PSV", NULL, &value);
1008         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1009                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
1010                 acpi_status status;
1011
1012                 status = acpi_evaluate_integer(handle, name, NULL, &value);
1013                 if (status == AE_NOT_FOUND)
1014                         break;
1015         }
1016         acpi_evaluate_integer(handle, "_TMP", NULL, &value);
1017 }
1018
1019 static int acpi_thermal_get_info(struct acpi_thermal *tz)
1020 {
1021         int result = 0;
1022
1023
1024         if (!tz)
1025                 return -EINVAL;
1026
1027         acpi_thermal_aml_dependency_fix(tz);
1028
1029         /* Get trip points [_CRT, _PSV, etc.] (required) */
1030         result = acpi_thermal_get_trip_points(tz);
1031         if (result)
1032                 return result;
1033
1034         /* Get temperature [_TMP] (required) */
1035         result = acpi_thermal_get_temperature(tz);
1036         if (result)
1037                 return result;
1038
1039         /* Set the cooling mode [_SCP] to active cooling (default) */
1040         result = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE);
1041         if (!result)
1042                 tz->flags.cooling_mode = 1;
1043
1044         /* Get default polling frequency [_TZP] (optional) */
1045         if (tzp)
1046                 tz->polling_frequency = tzp;
1047         else
1048                 acpi_thermal_get_polling_frequency(tz);
1049
1050         return 0;
1051 }
1052
1053 /*
1054  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
1055  * handles temperature values with a single decimal place. As a consequence,
1056  * some implementations use an offset of 273.1 and others use an offset of
1057  * 273.2. Try to find out which one is being used, to present the most
1058  * accurate and visually appealing number.
1059  *
1060  * The heuristic below should work for all ACPI thermal zones which have a
1061  * critical trip point with a value being a multiple of 0.5 degree Celsius.
1062  */
1063 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
1064 {
1065         if (tz->trips.critical.flags.valid &&
1066             (tz->trips.critical.temperature % 5) == 1)
1067                 tz->kelvin_offset = 2731;
1068         else
1069                 tz->kelvin_offset = 2732;
1070 }
1071
1072 static int acpi_thermal_add(struct acpi_device *device)
1073 {
1074         int result = 0;
1075         struct acpi_thermal *tz = NULL;
1076
1077
1078         if (!device)
1079                 return -EINVAL;
1080
1081         tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
1082         if (!tz)
1083                 return -ENOMEM;
1084
1085         tz->device = device;
1086         strcpy(tz->name, device->pnp.bus_id);
1087         strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
1088         strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
1089         device->driver_data = tz;
1090         mutex_init(&tz->lock);
1091
1092
1093         result = acpi_thermal_get_info(tz);
1094         if (result)
1095                 goto free_memory;
1096
1097         acpi_thermal_guess_offset(tz);
1098
1099         result = acpi_thermal_register_thermal_zone(tz);
1100         if (result)
1101                 goto free_memory;
1102
1103         printk(KERN_INFO PREFIX "%s [%s] (%ld C)\n",
1104                acpi_device_name(device), acpi_device_bid(device),
1105                KELVIN_TO_CELSIUS(tz->temperature));
1106         goto end;
1107
1108 free_memory:
1109         kfree(tz);
1110 end:
1111         return result;
1112 }
1113
1114 static int acpi_thermal_remove(struct acpi_device *device, int type)
1115 {
1116         struct acpi_thermal *tz = NULL;
1117
1118         if (!device || !acpi_driver_data(device))
1119                 return -EINVAL;
1120
1121         tz = acpi_driver_data(device);
1122
1123         acpi_thermal_unregister_thermal_zone(tz);
1124         mutex_destroy(&tz->lock);
1125         kfree(tz);
1126         return 0;
1127 }
1128
1129 #ifdef CONFIG_PM_SLEEP
1130 static int acpi_thermal_resume(struct device *dev)
1131 {
1132         struct acpi_thermal *tz;
1133         int i, j, power_state, result;
1134
1135         if (!dev)
1136                 return -EINVAL;
1137
1138         tz = acpi_driver_data(to_acpi_device(dev));
1139         if (!tz)
1140                 return -EINVAL;
1141
1142         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1143                 if (!(&tz->trips.active[i]))
1144                         break;
1145                 if (!tz->trips.active[i].flags.valid)
1146                         break;
1147                 tz->trips.active[i].flags.enabled = 1;
1148                 for (j = 0; j < tz->trips.active[i].devices.count; j++) {
1149                         result = acpi_bus_update_power(
1150                                         tz->trips.active[i].devices.handles[j],
1151                                         &power_state);
1152                         if (result || (power_state != ACPI_STATE_D0)) {
1153                                 tz->trips.active[i].flags.enabled = 0;
1154                                 break;
1155                         }
1156                 }
1157                 tz->state.active |= tz->trips.active[i].flags.enabled;
1158         }
1159
1160         acpi_thermal_check(tz);
1161
1162         return AE_OK;
1163 }
1164 #endif
1165
1166 static int thermal_act(const struct dmi_system_id *d) {
1167
1168         if (act == 0) {
1169                 printk(KERN_NOTICE "ACPI: %s detected: "
1170                         "disabling all active thermal trip points\n", d->ident);
1171                 act = -1;
1172         }
1173         return 0;
1174 }
1175 static int thermal_nocrt(const struct dmi_system_id *d) {
1176
1177         printk(KERN_NOTICE "ACPI: %s detected: "
1178                 "disabling all critical thermal trip point actions.\n", d->ident);
1179         nocrt = 1;
1180         return 0;
1181 }
1182 static int thermal_tzp(const struct dmi_system_id *d) {
1183
1184         if (tzp == 0) {
1185                 printk(KERN_NOTICE "ACPI: %s detected: "
1186                         "enabling thermal zone polling\n", d->ident);
1187                 tzp = 300;      /* 300 dS = 30 Seconds */
1188         }
1189         return 0;
1190 }
1191 static int thermal_psv(const struct dmi_system_id *d) {
1192
1193         if (psv == 0) {
1194                 printk(KERN_NOTICE "ACPI: %s detected: "
1195                         "disabling all passive thermal trip points\n", d->ident);
1196                 psv = -1;
1197         }
1198         return 0;
1199 }
1200
1201 static struct dmi_system_id thermal_dmi_table[] __initdata = {
1202         /*
1203          * Award BIOS on this AOpen makes thermal control almost worthless.
1204          * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1205          */
1206         {
1207          .callback = thermal_act,
1208          .ident = "AOpen i915GMm-HFS",
1209          .matches = {
1210                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1211                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1212                 },
1213         },
1214         {
1215          .callback = thermal_psv,
1216          .ident = "AOpen i915GMm-HFS",
1217          .matches = {
1218                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1219                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1220                 },
1221         },
1222         {
1223          .callback = thermal_tzp,
1224          .ident = "AOpen i915GMm-HFS",
1225          .matches = {
1226                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1227                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1228                 },
1229         },
1230         {
1231          .callback = thermal_nocrt,
1232          .ident = "Gigabyte GA-7ZX",
1233          .matches = {
1234                 DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1235                 DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1236                 },
1237         },
1238         {}
1239 };
1240
1241 static int __init acpi_thermal_init(void)
1242 {
1243         int result = 0;
1244
1245         dmi_check_system(thermal_dmi_table);
1246
1247         if (off) {
1248                 printk(KERN_NOTICE "ACPI: thermal control disabled\n");
1249                 return -ENODEV;
1250         }
1251
1252         result = acpi_bus_register_driver(&acpi_thermal_driver);
1253         if (result < 0)
1254                 return -ENODEV;
1255
1256         return 0;
1257 }
1258
1259 static void __exit acpi_thermal_exit(void)
1260 {
1261
1262         acpi_bus_unregister_driver(&acpi_thermal_driver);
1263
1264         return;
1265 }
1266
1267 module_init(acpi_thermal_init);
1268 module_exit(acpi_thermal_exit);