release/src-rt-6.x.4708/linux/linux-2.6.36/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/fs.h>
  39 #include <linux/dmi.h>
  40 #include <acpi/acpi_drivers.h>
  41 #include <linux/sched.h>
  42 #include <linux/thermal.h>
  43 #include <linux/platform_device.h>
  44
  45 /*
  46  * The driver is started with "kernel mode off" by default. That means, the BIOS
  47  * is still in control of the fan. In this mode the driver allows to read the
  48  * temperature of the cpu and a userspace tool may take over control of the fan.
  49  * If the driver is switched to "kernel mode" (e.g. via module parameter) the
  50  * driver is in full control of the fan. If you want the module to be started in
  51  * kernel mode by default, define the following:
  52  */
  53 #undef START_IN_KERNEL_MODE
  54
  55 #define DRV_VER "0.5.24"
  56
  57 /*
  58  * According to the Atom N270 datasheet,
  59  * (http://download.intel.com/design/processor/datashts/320032.pdf) the
  60  * CPU's optimal operating limits denoted in junction temperature as
  61  * measured by the on-die thermal monitor are within 0 <= Tj <= 90. So,
  62  * assume 89°C is critical temperature.
  63  */
  64 #define ACERHDF_TEMP_CRIT 89000
  65 #define ACERHDF_FAN_OFF 0
  66 #define ACERHDF_FAN_AUTO 1
  67
  68 /*
  69  * No matter what value the user puts into the fanon variable, turn on the fan
  70  * at 80 degree Celsius to prevent hardware damage
  71  */
  72 #define ACERHDF_MAX_FANON 80000
  73
  74 /*
  75  * Maximum interval between two temperature checks is 15 seconds, as the die
  76  * can get hot really fast under heavy load (plus we shouldn't forget about
  77  * possible impact of _external_ aggressive sources such as heaters, sun etc.)
  78  */
  79 #define ACERHDF_MAX_INTERVAL 15
  80
  81 #ifdef START_IN_KERNEL_MODE
  82 static int kernelmode = 1;
  83 #else
  84 static int kernelmode;
  85 #endif
  86
  87 static unsigned int interval = 10;
  88 static unsigned int fanon = 63000;
  89 static unsigned int fanoff = 58000;
  90 static unsigned int verbose;
  91 static unsigned int fanstate = ACERHDF_FAN_AUTO;
  92 static char force_bios[16];
  93 static char force_product[16];
  94 static unsigned int prev_interval;
  95 static struct thermal_zone_device *thz_dev;
  96 static struct thermal_cooling_device *cl_dev;
  97 static struct platform_device *acerhdf_dev;
  98
  99 module_param(kernelmode, uint, 0);
 100 MODULE_PARM_DESC(kernelmode, "Kernel mode fan control on / off");
 101 module_param(interval, uint, 0600);
 102 MODULE_PARM_DESC(interval, "Polling interval of temperature check");
 103 module_param(fanon, uint, 0600);
 104 MODULE_PARM_DESC(fanon, "Turn the fan on above this temperature");
 105 module_param(fanoff, uint, 0600);
 106 MODULE_PARM_DESC(fanoff, "Turn the fan off below this temperature");
 107 module_param(verbose, uint, 0600);
 108 MODULE_PARM_DESC(verbose, "Enable verbose dmesg output");
 109 module_param_string(force_bios, force_bios, 16, 0);
 110 MODULE_PARM_DESC(force_bios, "Force BIOS version and omit BIOS check");
 111 module_param_string(force_product, force_product, 16, 0);
 112 MODULE_PARM_DESC(force_product, "Force BIOS product and omit BIOS check");
 113
 114 /*
 115  * cmd_off: to switch the fan completely off and check if the fan is off
 116  *      cmd_auto: to set the BIOS in control of the fan. The BIOS regulates then
 117  *              the fan speed depending on the temperature
 118  */
 119 struct fancmd {
 120         u8 cmd_off;
 121         u8 cmd_auto;
 122 };
 123
 124 /* BIOS settings */
 125 struct bios_settings_t {
 126         const char *vendor;
 127         const char *product;
 128         const char *version;
 129         unsigned char fanreg;
 130         unsigned char tempreg;
 131         struct fancmd cmd;
 132 };
 133
 134 /* Register addresses and values for different BIOS versions */
 135 static const struct bios_settings_t bios_tbl[] = {
 136         /* AOA110 */
 137         {"Acer", "AOA110", "v0.3109", 0x55, 0x58, {0x1f, 0x00} },
 138         {"Acer", "AOA110", "v0.3114", 0x55, 0x58, {0x1f, 0x00} },
 139         {"Acer", "AOA110", "v0.3301", 0x55, 0x58, {0xaf, 0x00} },
 140         {"Acer", "AOA110", "v0.3304", 0x55, 0x58, {0xaf, 0x00} },
 141         {"Acer", "AOA110", "v0.3305", 0x55, 0x58, {0xaf, 0x00} },
 142         {"Acer", "AOA110", "v0.3307", 0x55, 0x58, {0xaf, 0x00} },
 143         {"Acer", "AOA110", "v0.3308", 0x55, 0x58, {0x21, 0x00} },
 144         {"Acer", "AOA110", "v0.3309", 0x55, 0x58, {0x21, 0x00} },
 145         {"Acer", "AOA110", "v0.3310", 0x55, 0x58, {0x21, 0x00} },
 146         /* AOA150 */
 147         {"Acer", "AOA150", "v0.3114", 0x55, 0x58, {0x1f, 0x00} },
 148         {"Acer", "AOA150", "v0.3301", 0x55, 0x58, {0x20, 0x00} },
 149         {"Acer", "AOA150", "v0.3304", 0x55, 0x58, {0x20, 0x00} },
 150         {"Acer", "AOA150", "v0.3305", 0x55, 0x58, {0x20, 0x00} },
 151         {"Acer", "AOA150", "v0.3307", 0x55, 0x58, {0x20, 0x00} },
 152         {"Acer", "AOA150", "v0.3308", 0x55, 0x58, {0x20, 0x00} },
 153         {"Acer", "AOA150", "v0.3309", 0x55, 0x58, {0x20, 0x00} },
 154         {"Acer", "AOA150", "v0.3310", 0x55, 0x58, {0x20, 0x00} },
 155         /* Acer 1410 */
 156         {"Acer", "Aspire 1410", "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
 157         {"Acer", "Aspire 1410", "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
 158         {"Acer", "Aspire 1410", "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
 159         {"Acer", "Aspire 1410", "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
 160         {"Acer", "Aspire 1410", "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
 161         {"Acer", "Aspire 1410", "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
 162         {"Acer", "Aspire 1410", "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
 163         {"Acer", "Aspire 1410", "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
 164         {"Acer", "Aspire 1410", "v1.3308", 0x55, 0x58, {0x9e, 0x00} },
 165         {"Acer", "Aspire 1410", "v1.3310", 0x55, 0x58, {0x9e, 0x00} },
 166         /* Acer 1810xx */
 167         {"Acer", "Aspire 1810TZ", "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
 168         {"Acer", "Aspire 1810T",  "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
 169         {"Acer", "Aspire 1810TZ", "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
 170         {"Acer", "Aspire 1810T",  "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
 171         {"Acer", "Aspire 1810TZ", "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
 172         {"Acer", "Aspire 1810T",  "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
 173         {"Acer", "Aspire 1810TZ", "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
 174         {"Acer", "Aspire 1810T",  "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
 175         {"Acer", "Aspire 1810TZ", "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
 176         {"Acer", "Aspire 1810T",  "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
 177         {"Acer", "Aspire 1810TZ", "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
 178         {"Acer", "Aspire 1810T",  "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
 179         {"Acer", "Aspire 1810TZ", "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
 180         {"Acer", "Aspire 1810T",  "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
 181         {"Acer", "Aspire 1810TZ", "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
 182         {"Acer", "Aspire 1810T",  "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
 183         {"Acer", "Aspire 1810TZ", "v1.3308", 0x55, 0x58, {0x9e, 0x00} },
 184         {"Acer", "Aspire 1810T",  "v1.3308", 0x55, 0x58, {0x9e, 0x00} },
 185         {"Acer", "Aspire 1810TZ", "v1.3310", 0x55, 0x58, {0x9e, 0x00} },
 186         {"Acer", "Aspire 1810T",  "v1.3310", 0x55, 0x58, {0x9e, 0x00} },
 187         /* Acer 531 */
 188         {"Acer", "AO531h", "v0.3201", 0x55, 0x58, {0x20, 0x00} },
 189         /* Gateway */
 190         {"Gateway", "AOA110", "v0.3103", 0x55, 0x58, {0x21, 0x00} },
 191         {"Gateway", "AOA150", "v0.3103", 0x55, 0x58, {0x20, 0x00} },
 192         {"Gateway", "LT31",   "v1.3103", 0x55, 0x58, {0x9e, 0x00} },
 193         {"Gateway", "LT31",   "v1.3201", 0x55, 0x58, {0x9e, 0x00} },
 194         {"Gateway", "LT31",   "v1.3302", 0x55, 0x58, {0x9e, 0x00} },
 195         /* Packard Bell */
 196         {"Packard Bell", "DOA150", "v0.3104", 0x55, 0x58, {0x21, 0x00} },
 197         {"Packard Bell", "DOA150", "v0.3105", 0x55, 0x58, {0x20, 0x00} },
 198         {"Packard Bell", "AOA110", "v0.3105", 0x55, 0x58, {0x21, 0x00} },
 199         {"Packard Bell", "AOA150", "v0.3105", 0x55, 0x58, {0x20, 0x00} },
 200         {"Packard Bell", "DOTMU",  "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
 201         {"Packard Bell", "DOTMU",  "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
 202         {"Packard Bell", "DOTMU",  "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
 203         {"Packard Bell", "DOTMU",  "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
 204         {"Packard Bell", "DOTMU",  "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
 205         {"Packard Bell", "DOTMU",  "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
 206         {"Packard Bell", "DOTMU",  "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
 207         {"Packard Bell", "DOTMU",  "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
 208         {"Packard Bell", "DOTMA",  "v1.3201", 0x55, 0x58, {0x9e, 0x00} },
 209         {"Packard Bell", "DOTMA",  "v1.3302", 0x55, 0x58, {0x9e, 0x00} },
 210         /* pewpew-terminator */
 211         {"", "", "", 0, 0, {0, 0} }
 212 };
 213
 214 static const struct bios_settings_t *bios_cfg __read_mostly;
 215
 216 static int acerhdf_get_temp(int *temp)
 217 {
 218         u8 read_temp;
 219
 220         if (ec_read(bios_cfg->tempreg, &read_temp))
 221                 return -EINVAL;
 222
 223         *temp = read_temp * 1000;
 224
 225         return 0;
 226 }
 227
 228 static int acerhdf_get_fanstate(int *state)
 229 {
 230         u8 fan;
 231
 232         if (ec_read(bios_cfg->fanreg, &fan))
 233                 return -EINVAL;
 234
 235         if (fan != bios_cfg->cmd.cmd_off)
 236                 *state = ACERHDF_FAN_AUTO;
 237         else
 238                 *state = ACERHDF_FAN_OFF;
 239
 240         return 0;
 241 }
 242
 243 static void acerhdf_change_fanstate(int state)
 244 {
 245         unsigned char cmd;
 246
 247         if (verbose)
 248                 pr_notice("fan %s\n", (state == ACERHDF_FAN_OFF) ?
 249                                 "OFF" : "ON");
 250
 251         if ((state != ACERHDF_FAN_OFF) && (state != ACERHDF_FAN_AUTO)) {
 252                 pr_err("invalid fan state %d requested, setting to auto!\n",
 253                         state);
 254                 state = ACERHDF_FAN_AUTO;
 255         }
 256
 257         cmd = (state == ACERHDF_FAN_OFF) ? bios_cfg->cmd.cmd_off
 258                                          : bios_cfg->cmd.cmd_auto;
 259         fanstate = state;
 260
 261         ec_write(bios_cfg->fanreg, cmd);
 262 }
 263
 264 static void acerhdf_check_param(struct thermal_zone_device *thermal)
 265 {
 266         if (fanon > ACERHDF_MAX_FANON) {
 267                 pr_err("fanon temperature too high, set to %d\n",
 268                                 ACERHDF_MAX_FANON);
 269                 fanon = ACERHDF_MAX_FANON;
 270         }
 271
 272         if (kernelmode && prev_interval != interval) {
 273                 if (interval > ACERHDF_MAX_INTERVAL) {
 274                         pr_err("interval too high, set to %d\n",
 275                                 ACERHDF_MAX_INTERVAL);
 276                         interval = ACERHDF_MAX_INTERVAL;
 277                 }
 278                 if (verbose)
 279                         pr_notice("interval changed to: %d\n",
 280                                         interval);
 281                 thermal->polling_delay = interval*1000;
 282                 prev_interval = interval;
 283         }
 284 }
 285
 286 /*
 287  * This is the thermal zone callback which does the delayed polling of the fan
 288  * state. We do check /sysfs-originating settings here in acerhdf_check_param()
 289  * as late as the polling interval is since we can't do that in the respective
 290  * accessors of the module parameters.
 291  */
 292 static int acerhdf_get_ec_temp(struct thermal_zone_device *thermal,
 293                                unsigned long *t)
 294 {
 295         int temp, err = 0;
 296
 297         acerhdf_check_param(thermal);
 298
 299         err = acerhdf_get_temp(&temp);
 300         if (err)
 301                 return err;
 302
 303         if (verbose)
 304                 pr_notice("temp %d\n", temp);
 305
 306         *t = temp;
 307         return 0;
 308 }
 309
 310 static int acerhdf_bind(struct thermal_zone_device *thermal,
 311                         struct thermal_cooling_device *cdev)
 312 {
 313         /* if the cooling device is the one from acerhdf bind it */
 314         if (cdev != cl_dev)
 315                 return 0;
 316
 317         if (thermal_zone_bind_cooling_device(thermal, 0, cdev)) {
 318                 pr_err("error binding cooling dev\n");
 319                 return -EINVAL;
 320         }
 321         return 0;
 322 }
 323
 324 static int acerhdf_unbind(struct thermal_zone_device *thermal,
 325                           struct thermal_cooling_device *cdev)
 326 {
 327         if (cdev != cl_dev)
 328                 return 0;
 329
 330         if (thermal_zone_unbind_cooling_device(thermal, 0, cdev)) {
 331                 pr_err("error unbinding cooling dev\n");
 332                 return -EINVAL;
 333         }
 334         return 0;
 335 }
 336
 337 static inline void acerhdf_revert_to_bios_mode(void)
 338 {
 339         acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 340         kernelmode = 0;
 341         if (thz_dev)
 342                 thz_dev->polling_delay = 0;
 343         pr_notice("kernel mode fan control OFF\n");
 344 }
 345 static inline void acerhdf_enable_kernelmode(void)
 346 {
 347         kernelmode = 1;
 348
 349         thz_dev->polling_delay = interval*1000;
 350         thermal_zone_device_update(thz_dev);
 351         pr_notice("kernel mode fan control ON\n");
 352 }
 353
 354 static int acerhdf_get_mode(struct thermal_zone_device *thermal,
 355                             enum thermal_device_mode *mode)
 356 {
 357         if (verbose)
 358                 pr_notice("kernel mode fan control %d\n", kernelmode);
 359
 360         *mode = (kernelmode) ? THERMAL_DEVICE_ENABLED
 361                              : THERMAL_DEVICE_DISABLED;
 362
 363         return 0;
 364 }
 365
 366 /*
 367  * set operation mode;
 368  * enabled: the thermal layer of the kernel takes care about
 369  *          the temperature and the fan.
 370  * disabled: the BIOS takes control of the fan.
 371  */
 372 static int acerhdf_set_mode(struct thermal_zone_device *thermal,
 373                             enum thermal_device_mode mode)
 374 {
 375         if (mode == THERMAL_DEVICE_DISABLED && kernelmode)
 376                 acerhdf_revert_to_bios_mode();
 377         else if (mode == THERMAL_DEVICE_ENABLED && !kernelmode)
 378                 acerhdf_enable_kernelmode();
 379
 380         return 0;
 381 }
 382
 383 static int acerhdf_get_trip_type(struct thermal_zone_device *thermal, int trip,
 384                                  enum thermal_trip_type *type)
 385 {
 386         if (trip == 0)
 387                 *type = THERMAL_TRIP_ACTIVE;
 388
 389         return 0;
 390 }
 391
 392 static int acerhdf_get_trip_temp(struct thermal_zone_device *thermal, int trip,
 393                                  unsigned long *temp)
 394 {
 395         if (trip == 0)
 396                 *temp = fanon;
 397
 398         return 0;
 399 }
 400
 401 static int acerhdf_get_crit_temp(struct thermal_zone_device *thermal,
 402                                  unsigned long *temperature)
 403 {
 404         *temperature = ACERHDF_TEMP_CRIT;
 405         return 0;
 406 }
 407
 408 /* bind callback functions to thermalzone */
 409 static struct thermal_zone_device_ops acerhdf_dev_ops = {
 410         .bind = acerhdf_bind,
 411         .unbind = acerhdf_unbind,
 412         .get_temp = acerhdf_get_ec_temp,
 413         .get_mode = acerhdf_get_mode,
 414         .set_mode = acerhdf_set_mode,
 415         .get_trip_type = acerhdf_get_trip_type,
 416         .get_trip_temp = acerhdf_get_trip_temp,
 417         .get_crit_temp = acerhdf_get_crit_temp,
 418 };
 419
 420
 421 /*
 422  * cooling device callback functions
 423  * get maximal fan cooling state
 424  */
 425 static int acerhdf_get_max_state(struct thermal_cooling_device *cdev,
 426                                  unsigned long *state)
 427 {
 428         *state = 1;
 429
 430         return 0;
 431 }
 432
 433 static int acerhdf_get_cur_state(struct thermal_cooling_device *cdev,
 434                                  unsigned long *state)
 435 {
 436         int err = 0, tmp;
 437
 438         err = acerhdf_get_fanstate(&tmp);
 439         if (err)
 440                 return err;
 441
 442         *state = (tmp == ACERHDF_FAN_AUTO) ? 1 : 0;
 443         return 0;
 444 }
 445
 446 /* change current fan state - is overwritten when running in kernel mode */
 447 static int acerhdf_set_cur_state(struct thermal_cooling_device *cdev,
 448                                  unsigned long state)
 449 {
 450         int cur_temp, cur_state, err = 0;
 451
 452         if (!kernelmode)
 453                 return 0;
 454
 455         err = acerhdf_get_temp(&cur_temp);
 456         if (err) {
 457                 pr_err("error reading temperature, hand off control to BIOS\n");
 458                 goto err_out;
 459         }
 460
 461         err = acerhdf_get_fanstate(&cur_state);
 462         if (err) {
 463                 pr_err("error reading fan state, hand off control to BIOS\n");
 464                 goto err_out;
 465         }
 466
 467         if (state == 0) {
 468                 /* turn fan off only if below fanoff temperature */
 469                 if ((cur_state == ACERHDF_FAN_AUTO) &&
 470                     (cur_temp < fanoff))
 471                         acerhdf_change_fanstate(ACERHDF_FAN_OFF);
 472         } else {
 473                 if (cur_state == ACERHDF_FAN_OFF)
 474                         acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 475         }
 476         return 0;
 477
 478 err_out:
 479         acerhdf_revert_to_bios_mode();
 480         return -EINVAL;
 481 }
 482
 483 /* bind fan callbacks to fan device */
 484 static struct thermal_cooling_device_ops acerhdf_cooling_ops = {
 485         .get_max_state = acerhdf_get_max_state,
 486         .get_cur_state = acerhdf_get_cur_state,
 487         .set_cur_state = acerhdf_set_cur_state,
 488 };
 489
 490 /* suspend / resume functionality */
 491 static int acerhdf_suspend(struct device *dev)
 492 {
 493         if (kernelmode)
 494                 acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 495
 496         if (verbose)
 497                 pr_notice("going suspend\n");
 498
 499         return 0;
 500 }
 501
 502 static int __devinit acerhdf_probe(struct platform_device *device)
 503 {
 504         return 0;
 505 }
 506
 507 static int acerhdf_remove(struct platform_device *device)
 508 {
 509         return 0;
 510 }
 511
 512 static const struct dev_pm_ops acerhdf_pm_ops = {
 513         .suspend = acerhdf_suspend,
 514         .freeze  = acerhdf_suspend,
 515 };
 516
 517 static struct platform_driver acerhdf_driver = {
 518         .driver = {
 519                 .name  = "acerhdf",
 520                 .owner = THIS_MODULE,
 521                 .pm    = &acerhdf_pm_ops,
 522         },
 523         .probe = acerhdf_probe,
 524         .remove = acerhdf_remove,
 525 };
 526
 527 /* checks if str begins with start */
 528 static int str_starts_with(const char *str, const char *start)
 529 {
 530         unsigned long str_len = 0, start_len = 0;
 531
 532         str_len = strlen(str);
 533         start_len = strlen(start);
 534
 535         if (str_len >= start_len &&
 536                         !strncmp(str, start, start_len))
 537                 return 1;
 538
 539         return 0;
 540 }
 541
 542 /* check hardware */
 543 static int acerhdf_check_hardware(void)
 544 {
 545         char const *vendor, *version, *product;
 546         const struct bios_settings_t *bt = NULL;
 547
 548         /* get BIOS data */
 549         vendor  = dmi_get_system_info(DMI_SYS_VENDOR);
 550         version = dmi_get_system_info(DMI_BIOS_VERSION);
 551         product = dmi_get_system_info(DMI_PRODUCT_NAME);
 552
 553         if (!vendor || !version || !product) {
 554                 pr_err("error getting hardware information\n");
 555                 return -EINVAL;
 556         }
 557
 558         pr_info("Acer Aspire One Fan driver, v.%s\n", DRV_VER);
 559
 560         if (force_bios[0]) {
 561                 version = force_bios;
 562                 pr_info("forcing BIOS version: %s\n", version);
 563                 kernelmode = 0;
 564         }
 565
 566         if (force_product[0]) {
 567                 product = force_product;
 568                 pr_info("forcing BIOS product: %s\n", product);
 569                 kernelmode = 0;
 570         }
 571
 572         if (verbose)
 573                 pr_info("BIOS info: %s %s, product: %s\n",
 574                         vendor, version, product);
 575
 576         /* search BIOS version and vendor in BIOS settings table */
 577         for (bt = bios_tbl; bt->vendor[0]; bt++) {
 578                 /*
 579                  * check if actual hardware BIOS vendor, product and version
 580                  * IDs start with the strings of BIOS table entry
 581                  */
 582                 if (str_starts_with(vendor, bt->vendor) &&
 583                                 str_starts_with(product, bt->product) &&
 584                                 str_starts_with(version, bt->version)) {
 585                         bios_cfg = bt;
 586                         break;
 587                 }
 588         }
 589
 590         if (!bios_cfg) {
 591                 pr_err("unknown (unsupported) BIOS version %s/%s/%s, "
 592                         "please report, aborting!\n", vendor, product, version);
 593                 return -EINVAL;
 594         }
 595
 596         /*
 597          * if started with kernel mode off, prevent the kernel from switching
 598          * off the fan
 599          */
 600         if (!kernelmode) {
 601                 pr_notice("Fan control off, to enable do:\n");
 602                 pr_notice("echo -n \"enabled\" > "
 603                         "/sys/class/thermal/thermal_zone0/mode\n");
 604         }
 605
 606         return 0;
 607 }
 608
 609 static int acerhdf_register_platform(void)
 610 {
 611         int err = 0;
 612
 613         err = platform_driver_register(&acerhdf_driver);
 614         if (err)
 615                 return err;
 616
 617         acerhdf_dev = platform_device_alloc("acerhdf", -1);
 618         if (!acerhdf_dev) {
 619                 err = -ENOMEM;
 620                 goto err_device_alloc;
 621         }
 622         err = platform_device_add(acerhdf_dev);
 623         if (err)
 624                 goto err_device_add;
 625
 626         return 0;
 627
 628 err_device_add:
 629         platform_device_put(acerhdf_dev);
 630 err_device_alloc:
 631         platform_driver_unregister(&acerhdf_driver);
 632         return err;
 633 }
 634
 635 static void acerhdf_unregister_platform(void)
 636 {
 637         platform_device_unregister(acerhdf_dev);
 638         platform_driver_unregister(&acerhdf_driver);
 639 }
 640
 641 static int acerhdf_register_thermal(void)
 642 {
 643         cl_dev = thermal_cooling_device_register("acerhdf-fan", NULL,
 644                                                  &acerhdf_cooling_ops);
 645
 646         if (IS_ERR(cl_dev))
 647                 return -EINVAL;
 648
 649         thz_dev = thermal_zone_device_register("acerhdf", 1, NULL,
 650                                               &acerhdf_dev_ops, 0, 0, 0,
 651                                               (kernelmode) ? interval*1000 : 0);
 652         if (IS_ERR(thz_dev))
 653                 return -EINVAL;
 654
 655         return 0;
 656 }
 657
 658 static void acerhdf_unregister_thermal(void)
 659 {
 660         if (cl_dev) {
 661                 thermal_cooling_device_unregister(cl_dev);
 662                 cl_dev = NULL;
 663         }
 664
 665         if (thz_dev) {
 666                 thermal_zone_device_unregister(thz_dev);
 667                 thz_dev = NULL;
 668         }
 669 }
 670
 671 static int __init acerhdf_init(void)
 672 {
 673         int err = 0;
 674
 675         err = acerhdf_check_hardware();
 676         if (err)
 677                 goto out_err;
 678
 679         err = acerhdf_register_platform();
 680         if (err)
 681                 goto out_err;
 682
 683         err = acerhdf_register_thermal();
 684         if (err)
 685                 goto err_unreg;
 686
 687         return 0;
 688
 689 err_unreg:
 690         acerhdf_unregister_thermal();
 691         acerhdf_unregister_platform();
 692
 693 out_err:
 694         return err;
 695 }
 696
 697 static void __exit acerhdf_exit(void)
 698 {
 699         acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 700         acerhdf_unregister_thermal();
 701         acerhdf_unregister_platform();
 702 }
 703
 704 MODULE_LICENSE("GPL");
 705 MODULE_AUTHOR("Peter Feuerer");
 706 MODULE_DESCRIPTION("Aspire One temperature and fan driver");
 707 MODULE_ALIAS("dmi:*:*Acer*:pnAOA*:");
 708 MODULE_ALIAS("dmi:*:*Acer*:pnAspire 1410*:");
 709 MODULE_ALIAS("dmi:*:*Acer*:pnAspire 1810*:");
 710 MODULE_ALIAS("dmi:*:*Acer*:pnAO531*:");
 711 MODULE_ALIAS("dmi:*:*Gateway*:pnAOA*:");
 712 MODULE_ALIAS("dmi:*:*Gateway*:pnLT31*:");
 713 MODULE_ALIAS("dmi:*:*Packard Bell*:pnAOA*:");
 714 MODULE_ALIAS("dmi:*:*Packard Bell*:pnDOA*:");
 715 MODULE_ALIAS("dmi:*:*Packard Bell*:pnDOTMU*:");
 716 MODULE_ALIAS("dmi:*:*Packard Bell*:pnDOTMA*:");
 717
 718 module_init(acerhdf_init);
 719 module_exit(acerhdf_exit);