drivers/platform/x86/acerhdf.c

   1 /*
   2  * acerhdf - A driver which monitors the temperature
   3  *           of the aspire one netbook, turns on/off the fan
   4  *           as soon as the upper/lower threshold is reached.
   5  *
   6  * (C) 2009 - Peter Feuerer     peter (a) piie.net
   7  *                              http://piie.net
   8  *     2009 Borislav Petkov <petkovbb@gmail.com>
   9  *
  10  * Inspired by and many thanks to:
  11  *  o acerfand   - Rachel Greenham
  12  *  o acer_ec.pl - Michael Kurz     michi.kurz (at) googlemail.com
  13  *               - Petr Tomasek     tomasek (#) etf,cuni,cz
  14  *               - Carlos Corbacho  cathectic (at) gmail.com
  15  *  o lkml       - Matthew Garrett
  16  *               - Borislav Petkov
  17  *               - Andreas Mohr
  18  *
  19  *  This program is free software; you can redistribute it and/or modify
  20  *  it under the terms of the GNU General Public License as published by
  21  *  the Free Software Foundation; either version 2 of the License, or
  22  *  (at your option) any later version.
  23  *
  24  *  This program is distributed in the hope that it will be useful,
  25  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  *  GNU General Public License for more details.
  28  *
  29  *  You should have received a copy of the GNU General Public License
  30  *  along with this program; if not, write to the Free Software
  31  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  32  */
  33
  34 #define pr_fmt(fmt) "acerhdf: " fmt
  35
  36 #include <linux/kernel.h>
  37 #include <linux/module.h>
  38 #include <linux/dmi.h>
  39 #include <linux/acpi.h>
  40 #include <linux/thermal.h>
  41 #include <linux/platform_device.h>
  42
  43 /*
  44  * The driver is started with "kernel mode off" by default. That means, the BIOS
  45  * is still in control of the fan. In this mode the driver allows to read the
  46  * temperature of the cpu and a userspace tool may take over control of the fan.
  47  * If the driver is switched to "kernel mode" (e.g. via module parameter) the
  48  * driver is in full control of the fan. If you want the module to be started in
  49  * kernel mode by default, define the following:
  50  */
  51 #undef START_IN_KERNEL_MODE
  52
  53 #define DRV_VER "0.5.24"
  54
  55 /*
  56  * According to the Atom N270 datasheet,
  57  * (http://download.intel.com/design/processor/datashts/320032.pdf) the
  58  * CPU's optimal operating limits denoted in junction temperature as
  59  * measured by the on-die thermal monitor are within 0 <= Tj <= 90. So,
  60  * assume 89°C is critical temperature.
  61  */
  62 #define ACERHDF_TEMP_CRIT 89000
  63 #define ACERHDF_FAN_OFF 0
  64 #define ACERHDF_FAN_AUTO 1
  65
  66 /*
  67  * No matter what value the user puts into the fanon variable, turn on the fan
  68  * at 80 degree Celsius to prevent hardware damage
  69  */
  70 #define ACERHDF_MAX_FANON 80000
  71
  72 /*
  73  * Maximum interval between two temperature checks is 15 seconds, as the die
  74  * can get hot really fast under heavy load (plus we shouldn't forget about
  75  * possible impact of _external_ aggressive sources such as heaters, sun etc.)
  76  */
  77 #define ACERHDF_MAX_INTERVAL 15
  78
  79 #ifdef START_IN_KERNEL_MODE
  80 static int kernelmode = 1;
  81 #else
  82 static int kernelmode;
  83 #endif
  84
  85 static unsigned int interval = 10;
  86 static unsigned int fanon = 63000;
  87 static unsigned int fanoff = 58000;
  88 static unsigned int verbose;
  89 static unsigned int fanstate = ACERHDF_FAN_AUTO;
  90 static char force_bios[16];
  91 static char force_product[16];
  92 static unsigned int prev_interval;
  93 static struct thermal_zone_device *thz_dev;
  94 static struct thermal_cooling_device *cl_dev;
  95 static struct platform_device *acerhdf_dev;
  96
  97 module_param(kernelmode, uint, 0);
  98 MODULE_PARM_DESC(kernelmode, "Kernel mode fan control on / off");
  99 module_param(interval, uint, 0600);
 100 MODULE_PARM_DESC(interval, "Polling interval of temperature check");
 101 module_param(fanon, uint, 0600);
 102 MODULE_PARM_DESC(fanon, "Turn the fan on above this temperature");
 103 module_param(fanoff, uint, 0600);
 104 MODULE_PARM_DESC(fanoff, "Turn the fan off below this temperature");
 105 module_param(verbose, uint, 0600);
 106 MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
 107 module_param_string(force_bios, force_bios, 16, 0);
 108 MODULE_PARM_DESC(force_bios, "Force BIOS version and omit BIOS check");
 109 module_param_string(force_product, force_product, 16, 0);
 110 MODULE_PARM_DESC(force_product, "Force BIOS product and omit BIOS check");
 111
 112 /*
 113  * cmd_off: to switch the fan completely off and check if the fan is off
 114  *      cmd_auto: to set the BIOS in control of the fan. The BIOS regulates then
 115  *              the fan speed depending on the temperature
 116  */
 117 struct fancmd {
 118         u8 cmd_off;
 119         u8 cmd_auto;
 120 };
 121
 122 /* BIOS settings */
 123 struct bios_settings_t {
 124         const char *vendor;
 125         const char *product;
 126         const char *version;
 127         unsigned char fanreg;
 128         unsigned char tempreg;
 129         struct fancmd cmd;
 130 };
 131
 132 /* Register addresses and values for different BIOS versions */
 133 static const struct bios_settings_t bios_tbl[] = {
 134         /* AOA110 */
 135         {"Acer", "AOA110", "v0.3109", 0x55, 0x58, {0x1f, 0x00} },
 136         {"Acer", "AOA110", "v0.3114", 0x55, 0x58, {0x1f, 0x00} },
 137         {"Acer", "AOA110", "v0.3301", 0x55, 0x58, {0xaf, 0x00} },
 138         {"Acer", "AOA110", "v0.3304", 0x55, 0x58, {0xaf, 0x00} },
 139         {"Acer", "AOA110", "v0.3305", 0x55, 0x58, {0xaf, 0x00} },
 140         {"Acer", "AOA110", "v0.3307", 0x55, 0x58, {0xaf, 0x00} },
 141         {"Acer", "AOA110", "v0.3308", 0x55, 0x58, {0x21, 0x00} },
 142         {"Acer", "AOA110", "v0.3309", 0x55, 0x58, {0x21, 0x00} },
 143         {"Acer", "AOA110", "v0.3310", 0x55, 0x58, {0x21, 0x00} },
 144         /* AOA150 */
 145         {"Acer", "AOA150", "v0.3114", 0x55, 0x58, {0x1f, 0x00} },
 146         {"Acer", "AOA150", "v0.3301", 0x55, 0x58, {0x20, 0x00} },
 147         {"Acer", "AOA150", "v0.3304", 0x55, 0x58, {0x20, 0x00} },
 148         {"Acer", "AOA150", "v0.3305", 0x55, 0x58, {0x20, 0x00} },
 149         {"Acer", "AOA150", "v0.3307", 0x55, 0x58, {0x20, 0x00} },
 150         {"Acer", "AOA150", "v0.3308", 0x55, 0x58, {0x20, 0x00} },
 151         {"Acer", "AOA150", "v0.3309", 0x55, 0x58, {0x20, 0x00} },
 152         {"Acer", "AOA150", "v0.3310", 0x55, 0x58, {0x20, 0x00} },
 153         /* Acer 1410 */
 154         {"Acer", "Aspire 1410", "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
 155         {"Acer", "Aspire 1410", "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
 156         {"Acer", "Aspire 1410", "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
 157         {"Acer", "Aspire 1410", "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
 158         {"Acer", "Aspire 1410", "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
 159         {"Acer", "Aspire 1410", "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
 160         {"Acer", "Aspire 1410", "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
 161         {"Acer", "Aspire 1410", "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
 162         {"Acer", "Aspire 1410", "v1.3308", 0x55, 0x58, {0x9e, 0x00} },
 163         {"Acer", "Aspire 1410", "v1.3310", 0x55, 0x58, {0x9e, 0x00} },
 164         /* Acer 1810xx */
 165         {"Acer", "Aspire 1810TZ", "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
 166         {"Acer", "Aspire 1810T",  "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
 167         {"Acer", "Aspire 1810TZ", "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
 168         {"Acer", "Aspire 1810T",  "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
 169         {"Acer", "Aspire 1810TZ", "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
 170         {"Acer", "Aspire 1810T",  "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
 171         {"Acer", "Aspire 1810TZ", "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
 172         {"Acer", "Aspire 1810T",  "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
 173         {"Acer", "Aspire 1810TZ", "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
 174         {"Acer", "Aspire 1810T",  "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
 175         {"Acer", "Aspire 1810TZ", "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
 176         {"Acer", "Aspire 1810T",  "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
 177         {"Acer", "Aspire 1810TZ", "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
 178         {"Acer", "Aspire 1810T",  "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
 179         {"Acer", "Aspire 1810TZ", "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
 180         {"Acer", "Aspire 1810T",  "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
 181         {"Acer", "Aspire 1810TZ", "v1.3308", 0x55, 0x58, {0x9e, 0x00} },
 182         {"Acer", "Aspire 1810T",  "v1.3308", 0x55, 0x58, {0x9e, 0x00} },
 183         {"Acer", "Aspire 1810TZ", "v1.3310", 0x55, 0x58, {0x9e, 0x00} },
 184         {"Acer", "Aspire 1810T",  "v1.3310", 0x55, 0x58, {0x9e, 0x00} },
 185         /* Acer 531 */
 186         {"Acer", "AO531h", "v0.3201", 0x55, 0x58, {0x20, 0x00} },
 187         /* Gateway */
 188         {"Gateway", "AOA110", "v0.3103", 0x55, 0x58, {0x21, 0x00} },
 189         {"Gateway", "AOA150", "v0.3103", 0x55, 0x58, {0x20, 0x00} },
 190         {"Gateway", "LT31",   "v1.3103", 0x55, 0x58, {0x9e, 0x00} },
 191         {"Gateway", "LT31",   "v1.3201", 0x55, 0x58, {0x9e, 0x00} },
 192         {"Gateway", "LT31",   "v1.3302", 0x55, 0x58, {0x9e, 0x00} },
 193         /* Packard Bell */
 194         {"Packard Bell", "DOA150", "v0.3104", 0x55, 0x58, {0x21, 0x00} },
 195         {"Packard Bell", "DOA150", "v0.3105", 0x55, 0x58, {0x20, 0x00} },
 196         {"Packard Bell", "AOA110", "v0.3105", 0x55, 0x58, {0x21, 0x00} },
 197         {"Packard Bell", "AOA150", "v0.3105", 0x55, 0x58, {0x20, 0x00} },
 198         {"Packard Bell", "DOTMU",  "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
 199         {"Packard Bell", "DOTMU",  "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
 200         {"Packard Bell", "DOTMU",  "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
 201         {"Packard Bell", "DOTMU",  "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
 202         {"Packard Bell", "DOTMU",  "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
 203         {"Packard Bell", "DOTMU",  "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
 204         {"Packard Bell", "DOTMU",  "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
 205         {"Packard Bell", "DOTMU",  "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
 206         {"Packard Bell", "DOTMA",  "v1.3201", 0x55, 0x58, {0x9e, 0x00} },
 207         {"Packard Bell", "DOTMA",  "v1.3302", 0x55, 0x58, {0x9e, 0x00} },
 208         /* pewpew-terminator */
 209         {"", "", "", 0, 0, {0, 0} }
 210 };
 211
 212 static const struct bios_settings_t *bios_cfg __read_mostly;
 213
 214 static int acerhdf_get_temp(int *temp)
 215 {
 216         u8 read_temp;
 217
 218         if (ec_read(bios_cfg->tempreg, &read_temp))
 219                 return -EINVAL;
 220
 221         *temp = read_temp * 1000;
 222
 223         return 0;
 224 }
 225
 226 static int acerhdf_get_fanstate(int *state)
 227 {
 228         u8 fan;
 229
 230         if (ec_read(bios_cfg->fanreg, &fan))
 231                 return -EINVAL;
 232
 233         if (fan != bios_cfg->cmd.cmd_off)
 234                 *state = ACERHDF_FAN_AUTO;
 235         else
 236                 *state = ACERHDF_FAN_OFF;
 237
 238         return 0;
 239 }
 240
 241 static void acerhdf_change_fanstate(int state)
 242 {
 243         unsigned char cmd;
 244
 245         if (verbose)
 246                 pr_notice("fan %s\n", (state == ACERHDF_FAN_OFF) ?
 247                                 "OFF" : "ON");
 248
 249         if ((state != ACERHDF_FAN_OFF) && (state != ACERHDF_FAN_AUTO)) {
 250                 pr_err("invalid fan state %d requested, setting to auto!\n",
 251                         state);
 252                 state = ACERHDF_FAN_AUTO;
 253         }
 254
 255         cmd = (state == ACERHDF_FAN_OFF) ? bios_cfg->cmd.cmd_off
 256                                          : bios_cfg->cmd.cmd_auto;
 257         fanstate = state;
 258
 259         ec_write(bios_cfg->fanreg, cmd);
 260 }
 261
 262 static void acerhdf_check_param(struct thermal_zone_device *thermal)
 263 {
 264         if (fanon > ACERHDF_MAX_FANON) {
 265                 pr_err("fanon temperature too high, set to %d\n",
 266                                 ACERHDF_MAX_FANON);
 267                 fanon = ACERHDF_MAX_FANON;
 268         }
 269
 270         if (kernelmode && prev_interval != interval) {
 271                 if (interval > ACERHDF_MAX_INTERVAL) {
 272                         pr_err("interval too high, set to %d\n",
 273                                 ACERHDF_MAX_INTERVAL);
 274                         interval = ACERHDF_MAX_INTERVAL;
 275                 }
 276                 if (verbose)
 277                         pr_notice("interval changed to: %d\n",
 278                                         interval);
 279                 thermal->polling_delay = interval*1000;
 280                 prev_interval = interval;
 281         }
 282 }
 283
 284 /*
 285  * This is the thermal zone callback which does the delayed polling of the fan
 286  * state. We do check /sysfs-originating settings here in acerhdf_check_param()
 287  * as late as the polling interval is since we can't do that in the respective
 288  * accessors of the module parameters.
 289  */
 290 static int acerhdf_get_ec_temp(struct thermal_zone_device *thermal,
 291                                unsigned long *t)
 292 {
 293         int temp, err = 0;
 294
 295         acerhdf_check_param(thermal);
 296
 297         err = acerhdf_get_temp(&temp);
 298         if (err)
 299                 return err;
 300
 301         if (verbose)
 302                 pr_notice("temp %d\n", temp);
 303
 304         *t = temp;
 305         return 0;
 306 }
 307
 308 static int acerhdf_bind(struct thermal_zone_device *thermal,
 309                         struct thermal_cooling_device *cdev)
 310 {
 311         /* if the cooling device is the one from acerhdf bind it */
 312         if (cdev != cl_dev)
 313                 return 0;
 314
 315         if (thermal_zone_bind_cooling_device(thermal, 0, cdev)) {
 316                 pr_err("error binding cooling dev\n");
 317                 return -EINVAL;
 318         }
 319         return 0;
 320 }
 321
 322 static int acerhdf_unbind(struct thermal_zone_device *thermal,
 323                           struct thermal_cooling_device *cdev)
 324 {
 325         if (cdev != cl_dev)
 326                 return 0;
 327
 328         if (thermal_zone_unbind_cooling_device(thermal, 0, cdev)) {
 329                 pr_err("error unbinding cooling dev\n");
 330                 return -EINVAL;
 331         }
 332         return 0;
 333 }
 334
 335 static inline void acerhdf_revert_to_bios_mode(void)
 336 {
 337         acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 338         kernelmode = 0;
 339         if (thz_dev)
 340                 thz_dev->polling_delay = 0;
 341         pr_notice("kernel mode fan control OFF\n");
 342 }
 343 static inline void acerhdf_enable_kernelmode(void)
 344 {
 345         kernelmode = 1;
 346
 347         thz_dev->polling_delay = interval*1000;
 348         thermal_zone_device_update(thz_dev);
 349         pr_notice("kernel mode fan control ON\n");
 350 }
 351
 352 static int acerhdf_get_mode(struct thermal_zone_device *thermal,
 353                             enum thermal_device_mode *mode)
 354 {
 355         if (verbose)
 356                 pr_notice("kernel mode fan control %d\n", kernelmode);
 357
 358         *mode = (kernelmode) ? THERMAL_DEVICE_ENABLED
 359                              : THERMAL_DEVICE_DISABLED;
 360
 361         return 0;
 362 }
 363
 364 /*
 365  * set operation mode;
 366  * enabled: the thermal layer of the kernel takes care about
 367  *          the temperature and the fan.
 368  * disabled: the BIOS takes control of the fan.
 369  */
 370 static int acerhdf_set_mode(struct thermal_zone_device *thermal,
 371                             enum thermal_device_mode mode)
 372 {
 373         if (mode == THERMAL_DEVICE_DISABLED && kernelmode)
 374                 acerhdf_revert_to_bios_mode();
 375         else if (mode == THERMAL_DEVICE_ENABLED && !kernelmode)
 376                 acerhdf_enable_kernelmode();
 377
 378         return 0;
 379 }
 380
 381 static int acerhdf_get_trip_type(struct thermal_zone_device *thermal, int trip,
 382                                  enum thermal_trip_type *type)
 383 {
 384         if (trip == 0)
 385                 *type = THERMAL_TRIP_ACTIVE;
 386
 387         return 0;
 388 }
 389
 390 static int acerhdf_get_trip_temp(struct thermal_zone_device *thermal, int trip,
 391                                  unsigned long *temp)
 392 {
 393         if (trip == 0)
 394                 *temp = fanon;
 395
 396         return 0;
 397 }
 398
 399 static int acerhdf_get_crit_temp(struct thermal_zone_device *thermal,
 400                                  unsigned long *temperature)
 401 {
 402         *temperature = ACERHDF_TEMP_CRIT;
 403         return 0;
 404 }
 405
 406 /* bind callback functions to thermalzone */
 407 static struct thermal_zone_device_ops acerhdf_dev_ops = {
 408         .bind = acerhdf_bind,
 409         .unbind = acerhdf_unbind,
 410         .get_temp = acerhdf_get_ec_temp,
 411         .get_mode = acerhdf_get_mode,
 412         .set_mode = acerhdf_set_mode,
 413         .get_trip_type = acerhdf_get_trip_type,
 414         .get_trip_temp = acerhdf_get_trip_temp,
 415         .get_crit_temp = acerhdf_get_crit_temp,
 416 };
 417
 418
 419 /*
 420  * cooling device callback functions
 421  * get maximal fan cooling state
 422  */
 423 static int acerhdf_get_max_state(struct thermal_cooling_device *cdev,
 424                                  unsigned long *state)
 425 {
 426         *state = 1;
 427
 428         return 0;
 429 }
 430
 431 static int acerhdf_get_cur_state(struct thermal_cooling_device *cdev,
 432                                  unsigned long *state)
 433 {
 434         int err = 0, tmp;
 435
 436         err = acerhdf_get_fanstate(&tmp);
 437         if (err)
 438                 return err;
 439
 440         *state = (tmp == ACERHDF_FAN_AUTO) ? 1 : 0;
 441         return 0;
 442 }
 443
 444 /* change current fan state - is overwritten when running in kernel mode */
 445 static int acerhdf_set_cur_state(struct thermal_cooling_device *cdev,
 446                                  unsigned long state)
 447 {
 448         int cur_temp, cur_state, err = 0;
 449
 450         if (!kernelmode)
 451                 return 0;
 452
 453         err = acerhdf_get_temp(&cur_temp);
 454         if (err) {
 455                 pr_err("error reading temperature, hand off control to BIOS\n");
 456                 goto err_out;
 457         }
 458
 459         err = acerhdf_get_fanstate(&cur_state);
 460         if (err) {
 461                 pr_err("error reading fan state, hand off control to BIOS\n");
 462                 goto err_out;
 463         }
 464
 465         if (state == 0) {
 466                 /* turn fan off only if below fanoff temperature */
 467                 if ((cur_state == ACERHDF_FAN_AUTO) &&
 468                     (cur_temp < fanoff))
 469                         acerhdf_change_fanstate(ACERHDF_FAN_OFF);
 470         } else {
 471                 if (cur_state == ACERHDF_FAN_OFF)
 472                         acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 473         }
 474         return 0;
 475
 476 err_out:
 477         acerhdf_revert_to_bios_mode();
 478         return -EINVAL;
 479 }
 480
 481 /* bind fan callbacks to fan device */
 482 static struct thermal_cooling_device_ops acerhdf_cooling_ops = {
 483         .get_max_state = acerhdf_get_max_state,
 484         .get_cur_state = acerhdf_get_cur_state,
 485         .set_cur_state = acerhdf_set_cur_state,
 486 };
 487
 488 /* suspend / resume functionality */
 489 static int acerhdf_suspend(struct device *dev)
 490 {
 491         if (kernelmode)
 492                 acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 493
 494         if (verbose)
 495                 pr_notice("going suspend\n");
 496
 497         return 0;
 498 }
 499
 500 static int __devinit acerhdf_probe(struct platform_device *device)
 501 {
 502         return 0;
 503 }
 504
 505 static int acerhdf_remove(struct platform_device *device)
 506 {
 507         return 0;
 508 }
 509
 510 static const struct dev_pm_ops acerhdf_pm_ops = {
 511         .suspend = acerhdf_suspend,
 512         .freeze  = acerhdf_suspend,
 513 };
 514
 515 static struct platform_driver acerhdf_driver = {
 516         .driver = {
 517                 .name  = "acerhdf",
 518                 .owner = THIS_MODULE,
 519                 .pm    = &acerhdf_pm_ops,
 520         },
 521         .probe = acerhdf_probe,
 522         .remove = acerhdf_remove,
 523 };
 524
 525 /* checks if str begins with start */
 526 static int str_starts_with(const char *str, const char *start)
 527 {
 528         unsigned long str_len = 0, start_len = 0;
 529
 530         str_len = strlen(str);
 531         start_len = strlen(start);
 532
 533         if (str_len >= start_len &&
 534                         !strncmp(str, start, start_len))
 535                 return 1;
 536
 537         return 0;
 538 }
 539
 540 /* check hardware */
 541 static int acerhdf_check_hardware(void)
 542 {
 543         char const *vendor, *version, *product;
 544         const struct bios_settings_t *bt = NULL;
 545
 546         /* get BIOS data */
 547         vendor  = dmi_get_system_info(DMI_SYS_VENDOR);
 548         version = dmi_get_system_info(DMI_BIOS_VERSION);
 549         product = dmi_get_system_info(DMI_PRODUCT_NAME);
 550
 551         if (!vendor || !version || !product) {
 552                 pr_err("error getting hardware information\n");
 553                 return -EINVAL;
 554         }
 555
 556         pr_info("Acer Aspire One Fan driver, v.%s\n", DRV_VER);
 557
 558         if (force_bios[0]) {
 559                 version = force_bios;
 560                 pr_info("forcing BIOS version: %s\n", version);
 561                 kernelmode = 0;
 562         }
 563
 564         if (force_product[0]) {
 565                 product = force_product;
 566                 pr_info("forcing BIOS product: %s\n", product);
 567                 kernelmode = 0;
 568         }
 569
 570         if (verbose)
 571                 pr_info("BIOS info: %s %s, product: %s\n",
 572                         vendor, version, product);
 573
 574         /* search BIOS version and vendor in BIOS settings table */
 575         for (bt = bios_tbl; bt->vendor[0]; bt++) {
 576                 /*
 577                  * check if actual hardware BIOS vendor, product and version
 578                  * IDs start with the strings of BIOS table entry
 579                  */
 580                 if (str_starts_with(vendor, bt->vendor) &&
 581                                 str_starts_with(product, bt->product) &&
 582                                 str_starts_with(version, bt->version)) {
 583                         bios_cfg = bt;
 584                         break;
 585                 }
 586         }
 587
 588         if (!bios_cfg) {
 589                 pr_err("unknown (unsupported) BIOS version %s/%s/%s, "
 590                         "please report, aborting!\n", vendor, product, version);
 591                 return -EINVAL;
 592         }
 593
 594         /*
 595          * if started with kernel mode off, prevent the kernel from switching
 596          * off the fan
 597          */
 598         if (!kernelmode) {
 599                 pr_notice("Fan control off, to enable do:\n");
 600                 pr_notice("echo -n \"enabled\" > "
 601                         "/sys/class/thermal/thermal_zone0/mode\n");
 602         }
 603
 604         return 0;
 605 }
 606
 607 static int acerhdf_register_platform(void)
 608 {
 609         int err = 0;
 610
 611         err = platform_driver_register(&acerhdf_driver);
 612         if (err)
 613                 return err;
 614
 615         acerhdf_dev = platform_device_alloc("acerhdf", -1);
 616         if (!acerhdf_dev) {
 617                 err = -ENOMEM;
 618                 goto err_device_alloc;
 619         }
 620         err = platform_device_add(acerhdf_dev);
 621         if (err)
 622                 goto err_device_add;
 623
 624         return 0;
 625
 626 err_device_add:
 627         platform_device_put(acerhdf_dev);
 628 err_device_alloc:
 629         platform_driver_unregister(&acerhdf_driver);
 630         return err;
 631 }
 632
 633 static void acerhdf_unregister_platform(void)
 634 {
 635         platform_device_unregister(acerhdf_dev);
 636         platform_driver_unregister(&acerhdf_driver);
 637 }
 638
 639 static int acerhdf_register_thermal(void)
 640 {
 641         cl_dev = thermal_cooling_device_register("acerhdf-fan", NULL,
 642                                                  &acerhdf_cooling_ops);
 643
 644         if (IS_ERR(cl_dev))
 645                 return -EINVAL;
 646
 647         thz_dev = thermal_zone_device_register("acerhdf", 1, NULL,
 648                                               &acerhdf_dev_ops, 0, 0, 0,
 649                                               (kernelmode) ? interval*1000 : 0);
 650         if (IS_ERR(thz_dev))
 651                 return -EINVAL;
 652
 653         return 0;
 654 }
 655
 656 static void acerhdf_unregister_thermal(void)
 657 {
 658         if (cl_dev) {
 659                 thermal_cooling_device_unregister(cl_dev);
 660                 cl_dev = NULL;
 661         }
 662
 663         if (thz_dev) {
 664                 thermal_zone_device_unregister(thz_dev);
 665                 thz_dev = NULL;
 666         }
 667 }
 668
 669 static int __init acerhdf_init(void)
 670 {
 671         int err = 0;
 672
 673         err = acerhdf_check_hardware();
 674         if (err)
 675                 goto out_err;
 676
 677         err = acerhdf_register_platform();
 678         if (err)
 679                 goto out_err;
 680
 681         err = acerhdf_register_thermal();
 682         if (err)
 683                 goto err_unreg;
 684
 685         return 0;
 686
 687 err_unreg:
 688         acerhdf_unregister_thermal();
 689         acerhdf_unregister_platform();
 690
 691 out_err:
 692         return err;
 693 }
 694
 695 static void __exit acerhdf_exit(void)
 696 {
 697         acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 698         acerhdf_unregister_thermal();
 699         acerhdf_unregister_platform();
 700 }
 701
 702 MODULE_LICENSE("GPL");
 703 MODULE_AUTHOR("Peter Feuerer");
 704 MODULE_DESCRIPTION("Aspire One temperature and fan driver");
 705 MODULE_ALIAS("dmi:*:*Acer*:pnAOA*:");
 706 MODULE_ALIAS("dmi:*:*Acer*:pnAspire 1410*:");
 707 MODULE_ALIAS("dmi:*:*Acer*:pnAspire 1810*:");
 708 MODULE_ALIAS("dmi:*:*Acer*:pnAO531*:");
 709 MODULE_ALIAS("dmi:*:*Gateway*:pnAOA*:");
 710 MODULE_ALIAS("dmi:*:*Gateway*:pnLT31*:");
 711 MODULE_ALIAS("dmi:*:*Packard Bell*:pnAOA*:");
 712 MODULE_ALIAS("dmi:*:*Packard Bell*:pnDOA*:");
 713 MODULE_ALIAS("dmi:*:*Packard Bell*:pnDOTMU*:");
 714 MODULE_ALIAS("dmi:*:*Packard Bell*:pnDOTMA*:");
 715
 716 module_init(acerhdf_init);
 717 module_exit(acerhdf_exit);