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);
 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 };
 194
 195 /* --------------------------------------------------------------------------
 196                              Thermal Zone Management
 197    -------------------------------------------------------------------------- */
 198
 199 static int acpi_thermal_get_temperature(struct acpi_thermal *tz)
 200 {
 201         acpi_status status = AE_OK;
 202         unsigned long long tmp;
 203
 204         if (!tz)
 205                 return -EINVAL;
 206
 207         tz->last_temperature = tz->temperature;
 208
 209         status = acpi_evaluate_integer(tz->device->handle, "_TMP", NULL, &tmp);
 210         if (ACPI_FAILURE(status))
 211                 return -ENODEV;
 212
 213         tz->temperature = tmp;
 214         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Temperature is %lu dK\n",
 215                           tz->temperature));
 216
 217         return 0;
 218 }
 219
 220 static int acpi_thermal_get_polling_frequency(struct acpi_thermal *tz)
 221 {
 222         acpi_status status = AE_OK;
 223         unsigned long long tmp;
 224
 225         if (!tz)
 226                 return -EINVAL;
 227
 228         status = acpi_evaluate_integer(tz->device->handle, "_TZP", NULL, &tmp);
 229         if (ACPI_FAILURE(status))
 230                 return -ENODEV;
 231
 232         tz->polling_frequency = tmp;
 233         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Polling frequency is %lu dS\n",
 234                           tz->polling_frequency));
 235
 236         return 0;
 237 }
 238
 239 static int acpi_thermal_set_cooling_mode(struct acpi_thermal *tz, int mode)
 240 {
 241         acpi_status status = AE_OK;
 242         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 243         struct acpi_object_list arg_list = { 1, &arg0 };
 244         acpi_handle handle = NULL;
 245
 246
 247         if (!tz)
 248                 return -EINVAL;
 249
 250         status = acpi_get_handle(tz->device->handle, "_SCP", &handle);
 251         if (ACPI_FAILURE(status)) {
 252                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "_SCP not present\n"));
 253                 return -ENODEV;
 254         }
 255
 256         arg0.integer.value = mode;
 257
 258         status = acpi_evaluate_object(handle, NULL, &arg_list, NULL);
 259         if (ACPI_FAILURE(status))
 260                 return -ENODEV;
 261
 262         return 0;
 263 }
 264
 265 #define ACPI_TRIPS_CRITICAL     0x01
 266 #define ACPI_TRIPS_HOT          0x02
 267 #define ACPI_TRIPS_PASSIVE      0x04
 268 #define ACPI_TRIPS_ACTIVE       0x08
 269 #define ACPI_TRIPS_DEVICES      0x10
 270
 271 #define ACPI_TRIPS_REFRESH_THRESHOLDS   (ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE)
 272 #define ACPI_TRIPS_REFRESH_DEVICES      ACPI_TRIPS_DEVICES
 273
 274 #define ACPI_TRIPS_INIT      (ACPI_TRIPS_CRITICAL | ACPI_TRIPS_HOT |    \
 275                               ACPI_TRIPS_PASSIVE | ACPI_TRIPS_ACTIVE |  \
 276                               ACPI_TRIPS_DEVICES)
 277
 278 /*
 279  * This exception is thrown out in two cases:
 280  * 1.An invalid trip point becomes invalid or a valid trip point becomes invalid
 281  *   when re-evaluating the AML code.
 282  * 2.TODO: Devices listed in _PSL, _ALx, _TZD may change.
 283  *   We need to re-bind the cooling devices of a thermal zone when this occurs.
 284  */
 285 #define ACPI_THERMAL_TRIPS_EXCEPTION(flags, str)        \
 286 do {    \
 287         if (flags != ACPI_TRIPS_INIT)   \
 288                 ACPI_EXCEPTION((AE_INFO, AE_ERROR,      \
 289                 "ACPI thermal trip point %s changed\n"  \
 290                 "Please send acpidump to linux-acpi@vger.kernel.org", str)); \
 291 } while (0)
 292
 293 static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 294 {
 295         acpi_status status = AE_OK;
 296         unsigned long long tmp;
 297         struct acpi_handle_list devices;
 298         int valid = 0;
 299         int i;
 300
 301         /* Critical Shutdown */
 302         if (flag & ACPI_TRIPS_CRITICAL) {
 303                 status = acpi_evaluate_integer(tz->device->handle,
 304                                 "_CRT", NULL, &tmp);
 305                 tz->trips.critical.temperature = tmp;
 306                 /*
 307                  * Treat freezing temperatures as invalid as well; some
 308                  * BIOSes return really low values and cause reboots at startup.
 309                  * Below zero (Celsius) values clearly aren't right for sure..
 310                  * ... so lets discard those as invalid.
 311                  */
 312                 if (ACPI_FAILURE(status)) {
 313                         tz->trips.critical.flags.valid = 0;
 314                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 315                                           "No critical threshold\n"));
 316                 } else if (tmp <= 2732) {
 317                         printk(KERN_WARNING FW_BUG "Invalid critical threshold "
 318                                "(%llu)\n", tmp);
 319                         tz->trips.critical.flags.valid = 0;
 320                 } else {
 321                         tz->trips.critical.flags.valid = 1;
 322                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 323                                           "Found critical threshold [%lu]\n",
 324                                           tz->trips.critical.temperature));
 325                 }
 326                 if (tz->trips.critical.flags.valid == 1) {
 327                         if (crt == -1) {
 328                                 tz->trips.critical.flags.valid = 0;
 329                         } else if (crt > 0) {
 330                                 unsigned long crt_k = CELSIUS_TO_KELVIN(crt);
 331                                 /*
 332                                  * Allow override critical threshold
 333                                  */
 334                                 if (crt_k > tz->trips.critical.temperature)
 335                                         printk(KERN_WARNING PREFIX
 336                                                 "Critical threshold %d C\n", crt);
 337                                 tz->trips.critical.temperature = crt_k;
 338                         }
 339                 }
 340         }
 341
 342         /* Critical Sleep (optional) */
 343         if (flag & ACPI_TRIPS_HOT) {
 344                 status = acpi_evaluate_integer(tz->device->handle,
 345                                 "_HOT", NULL, &tmp);
 346                 if (ACPI_FAILURE(status)) {
 347                         tz->trips.hot.flags.valid = 0;
 348                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 349                                         "No hot threshold\n"));
 350                 } else {
 351                         tz->trips.hot.temperature = tmp;
 352                         tz->trips.hot.flags.valid = 1;
 353                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 354                                         "Found hot threshold [%lu]\n",
 355                                         tz->trips.critical.temperature));
 356                 }
 357         }
 358
 359         /* Passive (optional) */
 360         if (((flag & ACPI_TRIPS_PASSIVE) && tz->trips.passive.flags.valid) ||
 361                 (flag == ACPI_TRIPS_INIT)) {
 362                 valid = tz->trips.passive.flags.valid;
 363                 if (psv == -1) {
 364                         status = AE_SUPPORT;
 365                 } else if (psv > 0) {
 366                         tmp = CELSIUS_TO_KELVIN(psv);
 367                         status = AE_OK;
 368                 } else {
 369                         status = acpi_evaluate_integer(tz->device->handle,
 370                                 "_PSV", NULL, &tmp);
 371                 }
 372
 373                 if (ACPI_FAILURE(status))
 374                         tz->trips.passive.flags.valid = 0;
 375                 else {
 376                         tz->trips.passive.temperature = tmp;
 377                         tz->trips.passive.flags.valid = 1;
 378                         if (flag == ACPI_TRIPS_INIT) {
 379                                 status = acpi_evaluate_integer(
 380                                                 tz->device->handle, "_TC1",
 381                                                 NULL, &tmp);
 382                                 if (ACPI_FAILURE(status))
 383                                         tz->trips.passive.flags.valid = 0;
 384                                 else
 385                                         tz->trips.passive.tc1 = tmp;
 386                                 status = acpi_evaluate_integer(
 387                                                 tz->device->handle, "_TC2",
 388                                                 NULL, &tmp);
 389                                 if (ACPI_FAILURE(status))
 390                                         tz->trips.passive.flags.valid = 0;
 391                                 else
 392                                         tz->trips.passive.tc2 = tmp;
 393                                 status = acpi_evaluate_integer(
 394                                                 tz->device->handle, "_TSP",
 395                                                 NULL, &tmp);
 396                                 if (ACPI_FAILURE(status))
 397                                         tz->trips.passive.flags.valid = 0;
 398                                 else
 399                                         tz->trips.passive.tsp = tmp;
 400                         }
 401                 }
 402         }
 403         if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.flags.valid) {
 404                 memset(&devices, 0, sizeof(struct acpi_handle_list));
 405                 status = acpi_evaluate_reference(tz->device->handle, "_PSL",
 406                                                         NULL, &devices);
 407                 if (ACPI_FAILURE(status)) {
 408                         printk(KERN_WARNING PREFIX
 409                                 "Invalid passive threshold\n");
 410                         tz->trips.passive.flags.valid = 0;
 411                 }
 412                 else
 413                         tz->trips.passive.flags.valid = 1;
 414
 415                 if (memcmp(&tz->trips.passive.devices, &devices,
 416                                 sizeof(struct acpi_handle_list))) {
 417                         memcpy(&tz->trips.passive.devices, &devices,
 418                                 sizeof(struct acpi_handle_list));
 419                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 420                 }
 421         }
 422         if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
 423                 if (valid != tz->trips.passive.flags.valid)
 424                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 425         }
 426
 427         /* Active (optional) */
 428         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 429                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
 430                 valid = tz->trips.active[i].flags.valid;
 431
 432                 if (act == -1)
 433                         break; /* disable all active trip points */
 434
 435                 if ((flag == ACPI_TRIPS_INIT) || ((flag & ACPI_TRIPS_ACTIVE) &&
 436                         tz->trips.active[i].flags.valid)) {
 437                         status = acpi_evaluate_integer(tz->device->handle,
 438                                                         name, NULL, &tmp);
 439                         if (ACPI_FAILURE(status)) {
 440                                 tz->trips.active[i].flags.valid = 0;
 441                                 if (i == 0)
 442                                         break;
 443                                 if (act <= 0)
 444                                         break;
 445                                 if (i == 1)
 446                                         tz->trips.active[0].temperature =
 447                                                 CELSIUS_TO_KELVIN(act);
 448                                 else
 449                                         /*
 450                                          * Don't allow override higher than
 451                                          * the next higher trip point
 452                                          */
 453                                         tz->trips.active[i - 1].temperature =
 454                                                 (tz->trips.active[i - 2].temperature <
 455                                                 CELSIUS_TO_KELVIN(act) ?
 456                                                 tz->trips.active[i - 2].temperature :
 457                                                 CELSIUS_TO_KELVIN(act));
 458                                 break;
 459                         } else {
 460                                 tz->trips.active[i].temperature = tmp;
 461                                 tz->trips.active[i].flags.valid = 1;
 462                         }
 463                 }
 464
 465                 name[2] = 'L';
 466                 if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.active[i].flags.valid ) {
 467                         memset(&devices, 0, sizeof(struct acpi_handle_list));
 468                         status = acpi_evaluate_reference(tz->device->handle,
 469                                                 name, NULL, &devices);
 470                         if (ACPI_FAILURE(status)) {
 471                                 printk(KERN_WARNING PREFIX
 472                                         "Invalid active%d threshold\n", i);
 473                                 tz->trips.active[i].flags.valid = 0;
 474                         }
 475                         else
 476                                 tz->trips.active[i].flags.valid = 1;
 477
 478                         if (memcmp(&tz->trips.active[i].devices, &devices,
 479                                         sizeof(struct acpi_handle_list))) {
 480                                 memcpy(&tz->trips.active[i].devices, &devices,
 481                                         sizeof(struct acpi_handle_list));
 482                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 483                         }
 484                 }
 485                 if ((flag & ACPI_TRIPS_ACTIVE) || (flag & ACPI_TRIPS_DEVICES))
 486                         if (valid != tz->trips.active[i].flags.valid)
 487                                 ACPI_THERMAL_TRIPS_EXCEPTION(flag, "state");
 488
 489                 if (!tz->trips.active[i].flags.valid)
 490                         break;
 491         }
 492
 493         if (flag & ACPI_TRIPS_DEVICES) {
 494                 memset(&devices, 0, sizeof(struct acpi_handle_list));
 495                 status = acpi_evaluate_reference(tz->device->handle, "_TZD",
 496                                                 NULL, &devices);
 497                 if (memcmp(&tz->devices, &devices,
 498                                 sizeof(struct acpi_handle_list))) {
 499                         memcpy(&tz->devices, &devices,
 500                                 sizeof(struct acpi_handle_list));
 501                         ACPI_THERMAL_TRIPS_EXCEPTION(flag, "device");
 502                 }
 503         }
 504
 505         return 0;
 506 }
 507
 508 static int acpi_thermal_get_trip_points(struct acpi_thermal *tz)
 509 {
 510         int i, valid, ret = acpi_thermal_trips_update(tz, ACPI_TRIPS_INIT);
 511
 512         if (ret)
 513                 return ret;
 514
 515         valid = tz->trips.critical.flags.valid |
 516                 tz->trips.hot.flags.valid |
 517                 tz->trips.passive.flags.valid;
 518
 519         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
 520                 valid |= tz->trips.active[i].flags.valid;
 521
 522         if (!valid) {
 523                 printk(KERN_WARNING FW_BUG "No valid trip found\n");
 524                 return -ENODEV;
 525         }
 526         return 0;
 527 }
 528
 529 static void acpi_thermal_check(void *data)
 530 {
 531         struct acpi_thermal *tz = data;
 532
 533         if (!tz->tz_enabled) {
 534                 pr_warn("thermal zone is disabled \n");
 535                 return;
 536         }
 537         thermal_zone_device_update(tz->thermal_zone);
 538 }
 539
 540 /* sys I/F for generic thermal sysfs support */
 541 #define KELVIN_TO_MILLICELSIUS(t, off) (((t) - (off)) * 100)
 542
 543 static int thermal_get_temp(struct thermal_zone_device *thermal,
 544                             unsigned long *temp)
 545 {
 546         struct acpi_thermal *tz = thermal->devdata;
 547         int result;
 548
 549         if (!tz)
 550                 return -EINVAL;
 551
 552         result = acpi_thermal_get_temperature(tz);
 553         if (result)
 554                 return result;
 555
 556         *temp = KELVIN_TO_MILLICELSIUS(tz->temperature, tz->kelvin_offset);
 557         return 0;
 558 }
 559
 560 static int thermal_get_mode(struct thermal_zone_device *thermal,
 561                                 enum thermal_device_mode *mode)
 562 {
 563         struct acpi_thermal *tz = thermal->devdata;
 564
 565         if (!tz)
 566                 return -EINVAL;
 567
 568         *mode = tz->tz_enabled ? THERMAL_DEVICE_ENABLED :
 569                 THERMAL_DEVICE_DISABLED;
 570
 571         return 0;
 572 }
 573
 574 static int thermal_set_mode(struct thermal_zone_device *thermal,
 575                                 enum thermal_device_mode mode)
 576 {
 577         struct acpi_thermal *tz = thermal->devdata;
 578         int enable;
 579
 580         if (!tz)
 581                 return -EINVAL;
 582
 583         /*
 584          * enable/disable thermal management from ACPI thermal driver
 585          */
 586         if (mode == THERMAL_DEVICE_ENABLED)
 587                 enable = 1;
 588         else if (mode == THERMAL_DEVICE_DISABLED)
 589                 enable = 0;
 590         else
 591                 return -EINVAL;
 592
 593         if (enable != tz->tz_enabled) {
 594                 tz->tz_enabled = enable;
 595                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 596                         "%s kernel ACPI thermal control\n",
 597                         tz->tz_enabled ? "Enable" : "Disable"));
 598                 acpi_thermal_check(tz);
 599         }
 600         return 0;
 601 }
 602
 603 static int thermal_get_trip_type(struct thermal_zone_device *thermal,
 604                                  int trip, enum thermal_trip_type *type)
 605 {
 606         struct acpi_thermal *tz = thermal->devdata;
 607         int i;
 608
 609         if (!tz || trip < 0)
 610                 return -EINVAL;
 611
 612         if (tz->trips.critical.flags.valid) {
 613                 if (!trip) {
 614                         *type = THERMAL_TRIP_CRITICAL;
 615                         return 0;
 616                 }
 617                 trip--;
 618         }
 619
 620         if (tz->trips.hot.flags.valid) {
 621                 if (!trip) {
 622                         *type = THERMAL_TRIP_HOT;
 623                         return 0;
 624                 }
 625                 trip--;
 626         }
 627
 628         if (tz->trips.passive.flags.valid) {
 629                 if (!trip) {
 630                         *type = THERMAL_TRIP_PASSIVE;
 631                         return 0;
 632                 }
 633                 trip--;
 634         }
 635
 636         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 637                 tz->trips.active[i].flags.valid; i++) {
 638                 if (!trip) {
 639                         *type = THERMAL_TRIP_ACTIVE;
 640                         return 0;
 641                 }
 642                 trip--;
 643         }
 644
 645         return -EINVAL;
 646 }
 647
 648 static int thermal_get_trip_temp(struct thermal_zone_device *thermal,
 649                                  int trip, unsigned long *temp)
 650 {
 651         struct acpi_thermal *tz = thermal->devdata;
 652         int i;
 653
 654         if (!tz || trip < 0)
 655                 return -EINVAL;
 656
 657         if (tz->trips.critical.flags.valid) {
 658                 if (!trip) {
 659                         *temp = KELVIN_TO_MILLICELSIUS(
 660                                 tz->trips.critical.temperature,
 661                                 tz->kelvin_offset);
 662                         return 0;
 663                 }
 664                 trip--;
 665         }
 666
 667         if (tz->trips.hot.flags.valid) {
 668                 if (!trip) {
 669                         *temp = KELVIN_TO_MILLICELSIUS(
 670                                 tz->trips.hot.temperature,
 671                                 tz->kelvin_offset);
 672                         return 0;
 673                 }
 674                 trip--;
 675         }
 676
 677         if (tz->trips.passive.flags.valid) {
 678                 if (!trip) {
 679                         *temp = KELVIN_TO_MILLICELSIUS(
 680                                 tz->trips.passive.temperature,
 681                                 tz->kelvin_offset);
 682                         return 0;
 683                 }
 684                 trip--;
 685         }
 686
 687         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 688                 tz->trips.active[i].flags.valid; i++) {
 689                 if (!trip) {
 690                         *temp = KELVIN_TO_MILLICELSIUS(
 691                                 tz->trips.active[i].temperature,
 692                                 tz->kelvin_offset);
 693                         return 0;
 694                 }
 695                 trip--;
 696         }
 697
 698         return -EINVAL;
 699 }
 700
 701 static int thermal_get_crit_temp(struct thermal_zone_device *thermal,
 702                                 unsigned long *temperature) {
 703         struct acpi_thermal *tz = thermal->devdata;
 704
 705         if (tz->trips.critical.flags.valid) {
 706                 *temperature = KELVIN_TO_MILLICELSIUS(
 707                                 tz->trips.critical.temperature,
 708                                 tz->kelvin_offset);
 709                 return 0;
 710         } else
 711                 return -EINVAL;
 712 }
 713
 714 static int thermal_get_trend(struct thermal_zone_device *thermal,
 715                                 int trip, enum thermal_trend *trend)
 716 {
 717         struct acpi_thermal *tz = thermal->devdata;
 718         enum thermal_trip_type type;
 719         int i;
 720
 721         if (thermal_get_trip_type(thermal, trip, &type))
 722                 return -EINVAL;
 723
 724         if (type == THERMAL_TRIP_ACTIVE) {
 725                 unsigned long trip_temp;
 726                 unsigned long temp = KELVIN_TO_MILLICELSIUS(tz->temperature,
 727                                                         tz->kelvin_offset);
 728                 if (thermal_get_trip_temp(thermal, trip, &trip_temp))
 729                         return -EINVAL;
 730
 731                 if (temp > trip_temp) {
 732                         *trend = THERMAL_TREND_RAISING;
 733                         return 0;
 734                 } else {
 735                         /* Fall back on default trend */
 736                         return -EINVAL;
 737                 }
 738         }
 739
 740         /*
 741          * tz->temperature has already been updated by generic thermal layer,
 742          * before this callback being invoked
 743          */
 744         i = (tz->trips.passive.tc1 * (tz->temperature - tz->last_temperature))
 745                 + (tz->trips.passive.tc2
 746                 * (tz->temperature - tz->trips.passive.temperature));
 747
 748         if (i > 0)
 749                 *trend = THERMAL_TREND_RAISING;
 750         else if (i < 0)
 751                 *trend = THERMAL_TREND_DROPPING;
 752         else
 753                 *trend = THERMAL_TREND_STABLE;
 754         return 0;
 755 }
 756
 757
 758 static int thermal_notify(struct thermal_zone_device *thermal, int trip,
 759                            enum thermal_trip_type trip_type)
 760 {
 761         u8 type = 0;
 762         struct acpi_thermal *tz = thermal->devdata;
 763
 764         if (trip_type == THERMAL_TRIP_CRITICAL)
 765                 type = ACPI_THERMAL_NOTIFY_CRITICAL;
 766         else if (trip_type == THERMAL_TRIP_HOT)
 767                 type = ACPI_THERMAL_NOTIFY_HOT;
 768         else
 769                 return 0;
 770
 771         acpi_bus_generate_netlink_event(tz->device->pnp.device_class,
 772                                         dev_name(&tz->device->dev), type, 1);
 773
 774         if (trip_type == THERMAL_TRIP_CRITICAL && nocrt)
 775                 return 1;
 776
 777         return 0;
 778 }
 779
 780 static int acpi_thermal_cooling_device_cb(struct thermal_zone_device *thermal,
 781                                         struct thermal_cooling_device *cdev,
 782                                         bool bind)
 783 {
 784         struct acpi_device *device = cdev->devdata;
 785         struct acpi_thermal *tz = thermal->devdata;
 786         struct acpi_device *dev;
 787         acpi_status status;
 788         acpi_handle handle;
 789         int i;
 790         int j;
 791         int trip = -1;
 792         int result = 0;
 793
 794         if (tz->trips.critical.flags.valid)
 795                 trip++;
 796
 797         if (tz->trips.hot.flags.valid)
 798                 trip++;
 799
 800         if (tz->trips.passive.flags.valid) {
 801                 trip++;
 802                 for (i = 0; i < tz->trips.passive.devices.count;
 803                     i++) {
 804                         handle = tz->trips.passive.devices.handles[i];
 805                         status = acpi_bus_get_device(handle, &dev);
 806                         if (ACPI_FAILURE(status) || dev != device)
 807                                 continue;
 808                         if (bind)
 809                                 result =
 810                                         thermal_zone_bind_cooling_device
 811                                         (thermal, trip, cdev,
 812                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT);
 813                         else
 814                                 result =
 815                                         thermal_zone_unbind_cooling_device
 816                                         (thermal, trip, cdev);
 817                         if (result)
 818                                 goto failed;
 819                 }
 820         }
 821
 822         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
 823                 if (!tz->trips.active[i].flags.valid)
 824                         break;
 825                 trip++;
 826                 for (j = 0;
 827                     j < tz->trips.active[i].devices.count;
 828                     j++) {
 829                         handle = tz->trips.active[i].devices.handles[j];
 830                         status = acpi_bus_get_device(handle, &dev);
 831                         if (ACPI_FAILURE(status) || dev != device)
 832                                 continue;
 833                         if (bind)
 834                                 result = thermal_zone_bind_cooling_device
 835                                         (thermal, trip, cdev,
 836                                          THERMAL_NO_LIMIT, THERMAL_NO_LIMIT);
 837                         else
 838                                 result = thermal_zone_unbind_cooling_device
 839                                         (thermal, trip, cdev);
 840                         if (result)
 841                                 goto failed;
 842                 }
 843         }
 844
 845         for (i = 0; i < tz->devices.count; i++) {
 846                 handle = tz->devices.handles[i];
 847                 status = acpi_bus_get_device(handle, &dev);
 848                 if (ACPI_SUCCESS(status) && (dev == device)) {
 849                         if (bind)
 850                                 result = thermal_zone_bind_cooling_device
 851                                                 (thermal, -1, cdev,
 852                                                  THERMAL_NO_LIMIT,
 853                                                  THERMAL_NO_LIMIT);
 854                         else
 855                                 result = thermal_zone_unbind_cooling_device
 856                                                 (thermal, -1, cdev);
 857                         if (result)
 858                                 goto failed;
 859                 }
 860         }
 861
 862 failed:
 863         return result;
 864 }
 865
 866 static int
 867 acpi_thermal_bind_cooling_device(struct thermal_zone_device *thermal,
 868                                         struct thermal_cooling_device *cdev)
 869 {
 870         return acpi_thermal_cooling_device_cb(thermal, cdev, true);
 871 }
 872
 873 static int
 874 acpi_thermal_unbind_cooling_device(struct thermal_zone_device *thermal,
 875                                         struct thermal_cooling_device *cdev)
 876 {
 877         return acpi_thermal_cooling_device_cb(thermal, cdev, false);
 878 }
 879
 880 static const struct thermal_zone_device_ops acpi_thermal_zone_ops = {
 881         .bind = acpi_thermal_bind_cooling_device,
 882         .unbind = acpi_thermal_unbind_cooling_device,
 883         .get_temp = thermal_get_temp,
 884         .get_mode = thermal_get_mode,
 885         .set_mode = thermal_set_mode,
 886         .get_trip_type = thermal_get_trip_type,
 887         .get_trip_temp = thermal_get_trip_temp,
 888         .get_crit_temp = thermal_get_crit_temp,
 889         .get_trend = thermal_get_trend,
 890         .notify = thermal_notify,
 891 };
 892
 893 static int acpi_thermal_register_thermal_zone(struct acpi_thermal *tz)
 894 {
 895         int trips = 0;
 896         int result;
 897         acpi_status status;
 898         int i;
 899
 900         if (tz->trips.critical.flags.valid)
 901                 trips++;
 902
 903         if (tz->trips.hot.flags.valid)
 904                 trips++;
 905
 906         if (tz->trips.passive.flags.valid)
 907                 trips++;
 908
 909         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE &&
 910                         tz->trips.active[i].flags.valid; i++, trips++);
 911
 912         if (tz->trips.passive.flags.valid)
 913                 tz->thermal_zone =
 914                         thermal_zone_device_register("acpitz", trips, 0, tz,
 915                                                 &acpi_thermal_zone_ops, NULL,
 916                                                      tz->trips.passive.tsp*100,
 917                                                      tz->polling_frequency*100);
 918         else
 919                 tz->thermal_zone =
 920                         thermal_zone_device_register("acpitz", trips, 0, tz,
 921                                                 &acpi_thermal_zone_ops, NULL,
 922                                                 0, tz->polling_frequency*100);
 923         if (IS_ERR(tz->thermal_zone))
 924                 return -ENODEV;
 925
 926         result = sysfs_create_link(&tz->device->dev.kobj,
 927                                    &tz->thermal_zone->device.kobj, "thermal_zone");
 928         if (result)
 929                 return result;
 930
 931         result = sysfs_create_link(&tz->thermal_zone->device.kobj,
 932                                    &tz->device->dev.kobj, "device");
 933         if (result)
 934                 return result;
 935
 936         status = acpi_attach_data(tz->device->handle,
 937                                   acpi_bus_private_data_handler,
 938                                   tz->thermal_zone);
 939         if (ACPI_FAILURE(status)) {
 940                 printk(KERN_ERR PREFIX
 941                                 "Error attaching device data\n");
 942                 return -ENODEV;
 943         }
 944
 945         tz->tz_enabled = 1;
 946
 947         dev_info(&tz->device->dev, "registered as thermal_zone%d\n",
 948                  tz->thermal_zone->id);
 949         return 0;
 950 }
 951
 952 static void acpi_thermal_unregister_thermal_zone(struct acpi_thermal *tz)
 953 {
 954         sysfs_remove_link(&tz->device->dev.kobj, "thermal_zone");
 955         sysfs_remove_link(&tz->thermal_zone->device.kobj, "device");
 956         thermal_zone_device_unregister(tz->thermal_zone);
 957         tz->thermal_zone = NULL;
 958         acpi_detach_data(tz->device->handle, acpi_bus_private_data_handler);
 959 }
 960
 961
 962 /* --------------------------------------------------------------------------
 963                                  Driver Interface
 964    -------------------------------------------------------------------------- */
 965
 966 static void acpi_thermal_notify(struct acpi_device *device, u32 event)
 967 {
 968         struct acpi_thermal *tz = acpi_driver_data(device);
 969
 970
 971         if (!tz)
 972                 return;
 973
 974         switch (event) {
 975         case ACPI_THERMAL_NOTIFY_TEMPERATURE:
 976                 acpi_thermal_check(tz);
 977                 break;
 978         case ACPI_THERMAL_NOTIFY_THRESHOLDS:
 979                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_THRESHOLDS);
 980                 acpi_thermal_check(tz);
 981                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 982                                                   dev_name(&device->dev), event, 0);
 983                 break;
 984         case ACPI_THERMAL_NOTIFY_DEVICES:
 985                 acpi_thermal_trips_update(tz, ACPI_TRIPS_REFRESH_DEVICES);
 986                 acpi_thermal_check(tz);
 987                 acpi_bus_generate_netlink_event(device->pnp.device_class,
 988                                                   dev_name(&device->dev), event, 0);
 989                 break;
 990         default:
 991                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 992                                   "Unsupported event [0x%x]\n", event));
 993                 break;
 994         }
 995 }
 996
 997 /*
 998  * On some platforms, the AML code has dependency about
 999  * the evaluating order of _TMP and _CRT/_HOT/_PSV/_ACx.
1000  * 1. On HP Pavilion G4-1016tx, _TMP must be invoked after
1001  *    /_CRT/_HOT/_PSV/_ACx, or else system will be power off.
1002  * 2. On HP Compaq 6715b/6715s, the return value of _PSV is 0
1003  *    if _TMP has never been evaluated.
1004  *
1005  * As this dependency is totally transparent to OS, evaluate
1006  * all of them once, in the order of _CRT/_HOT/_PSV/_ACx,
1007  * _TMP, before they are actually used.
1008  */
1009 static void acpi_thermal_aml_dependency_fix(struct acpi_thermal *tz)
1010 {
1011         acpi_handle handle = tz->device->handle;
1012         unsigned long long value;
1013         int i;
1014
1015         acpi_evaluate_integer(handle, "_CRT", NULL, &value);
1016         acpi_evaluate_integer(handle, "_HOT", NULL, &value);
1017         acpi_evaluate_integer(handle, "_PSV", NULL, &value);
1018         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1019                 char name[5] = { '_', 'A', 'C', ('0' + i), '\0' };
1020                 acpi_status status;
1021
1022                 status = acpi_evaluate_integer(handle, name, NULL, &value);
1023                 if (status == AE_NOT_FOUND)
1024                         break;
1025         }
1026         acpi_evaluate_integer(handle, "_TMP", NULL, &value);
1027 }
1028
1029 static int acpi_thermal_get_info(struct acpi_thermal *tz)
1030 {
1031         int result = 0;
1032
1033
1034         if (!tz)
1035                 return -EINVAL;
1036
1037         acpi_thermal_aml_dependency_fix(tz);
1038
1039         /* Get trip points [_CRT, _PSV, etc.] (required) */
1040         result = acpi_thermal_get_trip_points(tz);
1041         if (result)
1042                 return result;
1043
1044         /* Get temperature [_TMP] (required) */
1045         result = acpi_thermal_get_temperature(tz);
1046         if (result)
1047                 return result;
1048
1049         /* Set the cooling mode [_SCP] to active cooling (default) */
1050         result = acpi_thermal_set_cooling_mode(tz, ACPI_THERMAL_MODE_ACTIVE);
1051         if (!result)
1052                 tz->flags.cooling_mode = 1;
1053
1054         /* Get default polling frequency [_TZP] (optional) */
1055         if (tzp)
1056                 tz->polling_frequency = tzp;
1057         else
1058                 acpi_thermal_get_polling_frequency(tz);
1059
1060         return 0;
1061 }
1062
1063 /*
1064  * The exact offset between Kelvin and degree Celsius is 273.15. However ACPI
1065  * handles temperature values with a single decimal place. As a consequence,
1066  * some implementations use an offset of 273.1 and others use an offset of
1067  * 273.2. Try to find out which one is being used, to present the most
1068  * accurate and visually appealing number.
1069  *
1070  * The heuristic below should work for all ACPI thermal zones which have a
1071  * critical trip point with a value being a multiple of 0.5 degree Celsius.
1072  */
1073 static void acpi_thermal_guess_offset(struct acpi_thermal *tz)
1074 {
1075         if (tz->trips.critical.flags.valid &&
1076             (tz->trips.critical.temperature % 5) == 1)
1077                 tz->kelvin_offset = 2731;
1078         else
1079                 tz->kelvin_offset = 2732;
1080 }
1081
1082 static int acpi_thermal_add(struct acpi_device *device)
1083 {
1084         int result = 0;
1085         struct acpi_thermal *tz = NULL;
1086
1087
1088         if (!device)
1089                 return -EINVAL;
1090
1091         tz = kzalloc(sizeof(struct acpi_thermal), GFP_KERNEL);
1092         if (!tz)
1093                 return -ENOMEM;
1094
1095         tz->device = device;
1096         strcpy(tz->name, device->pnp.bus_id);
1097         strcpy(acpi_device_name(device), ACPI_THERMAL_DEVICE_NAME);
1098         strcpy(acpi_device_class(device), ACPI_THERMAL_CLASS);
1099         device->driver_data = tz;
1100
1101         result = acpi_thermal_get_info(tz);
1102         if (result)
1103                 goto free_memory;
1104
1105         acpi_thermal_guess_offset(tz);
1106
1107         result = acpi_thermal_register_thermal_zone(tz);
1108         if (result)
1109                 goto free_memory;
1110
1111         printk(KERN_INFO PREFIX "%s [%s] (%ld C)\n",
1112                acpi_device_name(device), acpi_device_bid(device),
1113                KELVIN_TO_CELSIUS(tz->temperature));
1114         goto end;
1115
1116 free_memory:
1117         kfree(tz);
1118 end:
1119         return result;
1120 }
1121
1122 static int acpi_thermal_remove(struct acpi_device *device)
1123 {
1124         struct acpi_thermal *tz = NULL;
1125
1126         if (!device || !acpi_driver_data(device))
1127                 return -EINVAL;
1128
1129         tz = acpi_driver_data(device);
1130
1131         acpi_thermal_unregister_thermal_zone(tz);
1132         kfree(tz);
1133         return 0;
1134 }
1135
1136 #ifdef CONFIG_PM_SLEEP
1137 static int acpi_thermal_resume(struct device *dev)
1138 {
1139         struct acpi_thermal *tz;
1140         int i, j, power_state, result;
1141
1142         if (!dev)
1143                 return -EINVAL;
1144
1145         tz = acpi_driver_data(to_acpi_device(dev));
1146         if (!tz)
1147                 return -EINVAL;
1148
1149         for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++) {
1150                 if (!(&tz->trips.active[i]))
1151                         break;
1152                 if (!tz->trips.active[i].flags.valid)
1153                         break;
1154                 tz->trips.active[i].flags.enabled = 1;
1155                 for (j = 0; j < tz->trips.active[i].devices.count; j++) {
1156                         result = acpi_bus_update_power(
1157                                         tz->trips.active[i].devices.handles[j],
1158                                         &power_state);
1159                         if (result || (power_state != ACPI_STATE_D0)) {
1160                                 tz->trips.active[i].flags.enabled = 0;
1161                                 break;
1162                         }
1163                 }
1164                 tz->state.active |= tz->trips.active[i].flags.enabled;
1165         }
1166
1167         acpi_thermal_check(tz);
1168
1169         return AE_OK;
1170 }
1171 #endif
1172
1173 static int thermal_act(const struct dmi_system_id *d) {
1174
1175         if (act == 0) {
1176                 printk(KERN_NOTICE "ACPI: %s detected: "
1177                         "disabling all active thermal trip points\n", d->ident);
1178                 act = -1;
1179         }
1180         return 0;
1181 }
1182 static int thermal_nocrt(const struct dmi_system_id *d) {
1183
1184         printk(KERN_NOTICE "ACPI: %s detected: "
1185                 "disabling all critical thermal trip point actions.\n", d->ident);
1186         nocrt = 1;
1187         return 0;
1188 }
1189 static int thermal_tzp(const struct dmi_system_id *d) {
1190
1191         if (tzp == 0) {
1192                 printk(KERN_NOTICE "ACPI: %s detected: "
1193                         "enabling thermal zone polling\n", d->ident);
1194                 tzp = 300;      /* 300 dS = 30 Seconds */
1195         }
1196         return 0;
1197 }
1198 static int thermal_psv(const struct dmi_system_id *d) {
1199
1200         if (psv == 0) {
1201                 printk(KERN_NOTICE "ACPI: %s detected: "
1202                         "disabling all passive thermal trip points\n", d->ident);
1203                 psv = -1;
1204         }
1205         return 0;
1206 }
1207
1208 static struct dmi_system_id thermal_dmi_table[] __initdata = {
1209         /*
1210          * Award BIOS on this AOpen makes thermal control almost worthless.
1211          * http://bugzilla.kernel.org/show_bug.cgi?id=8842
1212          */
1213         {
1214          .callback = thermal_act,
1215          .ident = "AOpen i915GMm-HFS",
1216          .matches = {
1217                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1218                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1219                 },
1220         },
1221         {
1222          .callback = thermal_psv,
1223          .ident = "AOpen i915GMm-HFS",
1224          .matches = {
1225                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1226                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1227                 },
1228         },
1229         {
1230          .callback = thermal_tzp,
1231          .ident = "AOpen i915GMm-HFS",
1232          .matches = {
1233                 DMI_MATCH(DMI_BOARD_VENDOR, "AOpen"),
1234                 DMI_MATCH(DMI_BOARD_NAME, "i915GMm-HFS"),
1235                 },
1236         },
1237         {
1238          .callback = thermal_nocrt,
1239          .ident = "Gigabyte GA-7ZX",
1240          .matches = {
1241                 DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."),
1242                 DMI_MATCH(DMI_BOARD_NAME, "7ZX"),
1243                 },
1244         },
1245         {}
1246 };
1247
1248 static int __init acpi_thermal_init(void)
1249 {
1250         int result = 0;
1251
1252         dmi_check_system(thermal_dmi_table);
1253
1254         if (off) {
1255                 printk(KERN_NOTICE "ACPI: thermal control disabled\n");
1256                 return -ENODEV;
1257         }
1258
1259         result = acpi_bus_register_driver(&acpi_thermal_driver);
1260         if (result < 0)
1261                 return -ENODEV;
1262
1263         return 0;
1264 }
1265
1266 static void __exit acpi_thermal_exit(void)
1267 {
1268
1269         acpi_bus_unregister_driver(&acpi_thermal_driver);
1270
1271         return;
1272 }
1273
1274 module_init(acpi_thermal_init);
1275 module_exit(acpi_thermal_exit);