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", "Aspire 1810TZ", "v1.3314", 0x55, 0x58, {0x9e, 0x00} },
 186         /* Acer 531 */
 187         {"Acer", "AO531h", "v0.3201", 0x55, 0x58, {0x20, 0x00} },
 188         /* Gateway */
 189         {"Gateway", "AOA110", "v0.3103", 0x55, 0x58, {0x21, 0x00} },
 190         {"Gateway", "AOA150", "v0.3103", 0x55, 0x58, {0x20, 0x00} },
 191         {"Gateway", "LT31",   "v1.3103", 0x55, 0x58, {0x9e, 0x00} },
 192         {"Gateway", "LT31",   "v1.3201", 0x55, 0x58, {0x9e, 0x00} },
 193         {"Gateway", "LT31",   "v1.3302", 0x55, 0x58, {0x9e, 0x00} },
 194         /* Packard Bell */
 195         {"Packard Bell", "DOA150", "v0.3104", 0x55, 0x58, {0x21, 0x00} },
 196         {"Packard Bell", "DOA150", "v0.3105", 0x55, 0x58, {0x20, 0x00} },
 197         {"Packard Bell", "AOA110", "v0.3105", 0x55, 0x58, {0x21, 0x00} },
 198         {"Packard Bell", "AOA150", "v0.3105", 0x55, 0x58, {0x20, 0x00} },
 199         {"Packard Bell", "DOTMU",  "v1.3303", 0x55, 0x58, {0x9e, 0x00} },
 200         {"Packard Bell", "DOTMU",  "v0.3120", 0x55, 0x58, {0x9e, 0x00} },
 201         {"Packard Bell", "DOTMU",  "v0.3108", 0x55, 0x58, {0x9e, 0x00} },
 202         {"Packard Bell", "DOTMU",  "v0.3113", 0x55, 0x58, {0x9e, 0x00} },
 203         {"Packard Bell", "DOTMU",  "v0.3115", 0x55, 0x58, {0x9e, 0x00} },
 204         {"Packard Bell", "DOTMU",  "v0.3117", 0x55, 0x58, {0x9e, 0x00} },
 205         {"Packard Bell", "DOTMU",  "v0.3119", 0x55, 0x58, {0x9e, 0x00} },
 206         {"Packard Bell", "DOTMU",  "v1.3204", 0x55, 0x58, {0x9e, 0x00} },
 207         {"Packard Bell", "DOTMA",  "v1.3201", 0x55, 0x58, {0x9e, 0x00} },
 208         {"Packard Bell", "DOTMA",  "v1.3302", 0x55, 0x58, {0x9e, 0x00} },
 209         /* pewpew-terminator */
 210         {"", "", "", 0, 0, {0, 0} }
 211 };
 212
 213 static const struct bios_settings_t *bios_cfg __read_mostly;
 214
 215 static int acerhdf_get_temp(int *temp)
 216 {
 217         u8 read_temp;
 218
 219         if (ec_read(bios_cfg->tempreg, &read_temp))
 220                 return -EINVAL;
 221
 222         *temp = read_temp * 1000;
 223
 224         return 0;
 225 }
 226
 227 static int acerhdf_get_fanstate(int *state)
 228 {
 229         u8 fan;
 230
 231         if (ec_read(bios_cfg->fanreg, &fan))
 232                 return -EINVAL;
 233
 234         if (fan != bios_cfg->cmd.cmd_off)
 235                 *state = ACERHDF_FAN_AUTO;
 236         else
 237                 *state = ACERHDF_FAN_OFF;
 238
 239         return 0;
 240 }
 241
 242 static void acerhdf_change_fanstate(int state)
 243 {
 244         unsigned char cmd;
 245
 246         if (verbose)
 247                 pr_notice("fan %s\n", (state == ACERHDF_FAN_OFF) ?
 248                                 "OFF" : "ON");
 249
 250         if ((state != ACERHDF_FAN_OFF) && (state != ACERHDF_FAN_AUTO)) {
 251                 pr_err("invalid fan state %d requested, setting to auto!\n",
 252                         state);
 253                 state = ACERHDF_FAN_AUTO;
 254         }
 255
 256         cmd = (state == ACERHDF_FAN_OFF) ? bios_cfg->cmd.cmd_off
 257                                          : bios_cfg->cmd.cmd_auto;
 258         fanstate = state;
 259
 260         ec_write(bios_cfg->fanreg, cmd);
 261 }
 262
 263 static void acerhdf_check_param(struct thermal_zone_device *thermal)
 264 {
 265         if (fanon > ACERHDF_MAX_FANON) {
 266                 pr_err("fanon temperature too high, set to %d\n",
 267                                 ACERHDF_MAX_FANON);
 268                 fanon = ACERHDF_MAX_FANON;
 269         }
 270
 271         if (kernelmode && prev_interval != interval) {
 272                 if (interval > ACERHDF_MAX_INTERVAL) {
 273                         pr_err("interval too high, set to %d\n",
 274                                 ACERHDF_MAX_INTERVAL);
 275                         interval = ACERHDF_MAX_INTERVAL;
 276                 }
 277                 if (verbose)
 278                         pr_notice("interval changed to: %d\n",
 279                                         interval);
 280                 thermal->polling_delay = interval*1000;
 281                 prev_interval = interval;
 282         }
 283 }
 284
 285 /*
 286  * This is the thermal zone callback which does the delayed polling of the fan
 287  * state. We do check /sysfs-originating settings here in acerhdf_check_param()
 288  * as late as the polling interval is since we can't do that in the respective
 289  * accessors of the module parameters.
 290  */
 291 static int acerhdf_get_ec_temp(struct thermal_zone_device *thermal,
 292                                unsigned long *t)
 293 {
 294         int temp, err = 0;
 295
 296         acerhdf_check_param(thermal);
 297
 298         err = acerhdf_get_temp(&temp);
 299         if (err)
 300                 return err;
 301
 302         if (verbose)
 303                 pr_notice("temp %d\n", temp);
 304
 305         *t = temp;
 306         return 0;
 307 }
 308
 309 static int acerhdf_bind(struct thermal_zone_device *thermal,
 310                         struct thermal_cooling_device *cdev)
 311 {
 312         /* if the cooling device is the one from acerhdf bind it */
 313         if (cdev != cl_dev)
 314                 return 0;
 315
 316         if (thermal_zone_bind_cooling_device(thermal, 0, cdev)) {
 317                 pr_err("error binding cooling dev\n");
 318                 return -EINVAL;
 319         }
 320         return 0;
 321 }
 322
 323 static int acerhdf_unbind(struct thermal_zone_device *thermal,
 324                           struct thermal_cooling_device *cdev)
 325 {
 326         if (cdev != cl_dev)
 327                 return 0;
 328
 329         if (thermal_zone_unbind_cooling_device(thermal, 0, cdev)) {
 330                 pr_err("error unbinding cooling dev\n");
 331                 return -EINVAL;
 332         }
 333         return 0;
 334 }
 335
 336 static inline void acerhdf_revert_to_bios_mode(void)
 337 {
 338         acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 339         kernelmode = 0;
 340         if (thz_dev)
 341                 thz_dev->polling_delay = 0;
 342         pr_notice("kernel mode fan control OFF\n");
 343 }
 344 static inline void acerhdf_enable_kernelmode(void)
 345 {
 346         kernelmode = 1;
 347
 348         thz_dev->polling_delay = interval*1000;
 349         thermal_zone_device_update(thz_dev);
 350         pr_notice("kernel mode fan control ON\n");
 351 }
 352
 353 static int acerhdf_get_mode(struct thermal_zone_device *thermal,
 354                             enum thermal_device_mode *mode)
 355 {
 356         if (verbose)
 357                 pr_notice("kernel mode fan control %d\n", kernelmode);
 358
 359         *mode = (kernelmode) ? THERMAL_DEVICE_ENABLED
 360                              : THERMAL_DEVICE_DISABLED;
 361
 362         return 0;
 363 }
 364
 365 /*
 366  * set operation mode;
 367  * enabled: the thermal layer of the kernel takes care about
 368  *          the temperature and the fan.
 369  * disabled: the BIOS takes control of the fan.
 370  */
 371 static int acerhdf_set_mode(struct thermal_zone_device *thermal,
 372                             enum thermal_device_mode mode)
 373 {
 374         if (mode == THERMAL_DEVICE_DISABLED && kernelmode)
 375                 acerhdf_revert_to_bios_mode();
 376         else if (mode == THERMAL_DEVICE_ENABLED && !kernelmode)
 377                 acerhdf_enable_kernelmode();
 378
 379         return 0;
 380 }
 381
 382 static int acerhdf_get_trip_type(struct thermal_zone_device *thermal, int trip,
 383                                  enum thermal_trip_type *type)
 384 {
 385         if (trip == 0)
 386                 *type = THERMAL_TRIP_ACTIVE;
 387
 388         return 0;
 389 }
 390
 391 static int acerhdf_get_trip_temp(struct thermal_zone_device *thermal, int trip,
 392                                  unsigned long *temp)
 393 {
 394         if (trip == 0)
 395                 *temp = fanon;
 396
 397         return 0;
 398 }
 399
 400 static int acerhdf_get_crit_temp(struct thermal_zone_device *thermal,
 401                                  unsigned long *temperature)
 402 {
 403         *temperature = ACERHDF_TEMP_CRIT;
 404         return 0;
 405 }
 406
 407 /* bind callback functions to thermalzone */
 408 static struct thermal_zone_device_ops acerhdf_dev_ops = {
 409         .bind = acerhdf_bind,
 410         .unbind = acerhdf_unbind,
 411         .get_temp = acerhdf_get_ec_temp,
 412         .get_mode = acerhdf_get_mode,
 413         .set_mode = acerhdf_set_mode,
 414         .get_trip_type = acerhdf_get_trip_type,
 415         .get_trip_temp = acerhdf_get_trip_temp,
 416         .get_crit_temp = acerhdf_get_crit_temp,
 417 };
 418
 419
 420 /*
 421  * cooling device callback functions
 422  * get maximal fan cooling state
 423  */
 424 static int acerhdf_get_max_state(struct thermal_cooling_device *cdev,
 425                                  unsigned long *state)
 426 {
 427         *state = 1;
 428
 429         return 0;
 430 }
 431
 432 static int acerhdf_get_cur_state(struct thermal_cooling_device *cdev,
 433                                  unsigned long *state)
 434 {
 435         int err = 0, tmp;
 436
 437         err = acerhdf_get_fanstate(&tmp);
 438         if (err)
 439                 return err;
 440
 441         *state = (tmp == ACERHDF_FAN_AUTO) ? 1 : 0;
 442         return 0;
 443 }
 444
 445 /* change current fan state - is overwritten when running in kernel mode */
 446 static int acerhdf_set_cur_state(struct thermal_cooling_device *cdev,
 447                                  unsigned long state)
 448 {
 449         int cur_temp, cur_state, err = 0;
 450
 451         if (!kernelmode)
 452                 return 0;
 453
 454         err = acerhdf_get_temp(&cur_temp);
 455         if (err) {
 456                 pr_err("error reading temperature, hand off control to BIOS\n");
 457                 goto err_out;
 458         }
 459
 460         err = acerhdf_get_fanstate(&cur_state);
 461         if (err) {
 462                 pr_err("error reading fan state, hand off control to BIOS\n");
 463                 goto err_out;
 464         }
 465
 466         if (state == 0) {
 467                 /* turn fan off only if below fanoff temperature */
 468                 if ((cur_state == ACERHDF_FAN_AUTO) &&
 469                     (cur_temp < fanoff))
 470                         acerhdf_change_fanstate(ACERHDF_FAN_OFF);
 471         } else {
 472                 if (cur_state == ACERHDF_FAN_OFF)
 473                         acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 474         }
 475         return 0;
 476
 477 err_out:
 478         acerhdf_revert_to_bios_mode();
 479         return -EINVAL;
 480 }
 481
 482 /* bind fan callbacks to fan device */
 483 static struct thermal_cooling_device_ops acerhdf_cooling_ops = {
 484         .get_max_state = acerhdf_get_max_state,
 485         .get_cur_state = acerhdf_get_cur_state,
 486         .set_cur_state = acerhdf_set_cur_state,
 487 };
 488
 489 /* suspend / resume functionality */
 490 static int acerhdf_suspend(struct device *dev)
 491 {
 492         if (kernelmode)
 493                 acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 494
 495         if (verbose)
 496                 pr_notice("going suspend\n");
 497
 498         return 0;
 499 }
 500
 501 static int __devinit acerhdf_probe(struct platform_device *device)
 502 {
 503         return 0;
 504 }
 505
 506 static int acerhdf_remove(struct platform_device *device)
 507 {
 508         return 0;
 509 }
 510
 511 static const struct dev_pm_ops acerhdf_pm_ops = {
 512         .suspend = acerhdf_suspend,
 513         .freeze  = acerhdf_suspend,
 514 };
 515
 516 static struct platform_driver acerhdf_driver = {
 517         .driver = {
 518                 .name  = "acerhdf",
 519                 .owner = THIS_MODULE,
 520                 .pm    = &acerhdf_pm_ops,
 521         },
 522         .probe = acerhdf_probe,
 523         .remove = acerhdf_remove,
 524 };
 525
 526 /* checks if str begins with start */
 527 static int str_starts_with(const char *str, const char *start)
 528 {
 529         unsigned long str_len = 0, start_len = 0;
 530
 531         str_len = strlen(str);
 532         start_len = strlen(start);
 533
 534         if (str_len >= start_len &&
 535                         !strncmp(str, start, start_len))
 536                 return 1;
 537
 538         return 0;
 539 }
 540
 541 /* check hardware */
 542 static int acerhdf_check_hardware(void)
 543 {
 544         char const *vendor, *version, *product;
 545         const struct bios_settings_t *bt = NULL;
 546
 547         /* get BIOS data */
 548         vendor  = dmi_get_system_info(DMI_SYS_VENDOR);
 549         version = dmi_get_system_info(DMI_BIOS_VERSION);
 550         product = dmi_get_system_info(DMI_PRODUCT_NAME);
 551
 552         if (!vendor || !version || !product) {
 553                 pr_err("error getting hardware information\n");
 554                 return -EINVAL;
 555         }
 556
 557         pr_info("Acer Aspire One Fan driver, v.%s\n", DRV_VER);
 558
 559         if (force_bios[0]) {
 560                 version = force_bios;
 561                 pr_info("forcing BIOS version: %s\n", version);
 562                 kernelmode = 0;
 563         }
 564
 565         if (force_product[0]) {
 566                 product = force_product;
 567                 pr_info("forcing BIOS product: %s\n", product);
 568                 kernelmode = 0;
 569         }
 570
 571         if (verbose)
 572                 pr_info("BIOS info: %s %s, product: %s\n",
 573                         vendor, version, product);
 574
 575         /* search BIOS version and vendor in BIOS settings table */
 576         for (bt = bios_tbl; bt->vendor[0]; bt++) {
 577                 /*
 578                  * check if actual hardware BIOS vendor, product and version
 579                  * IDs start with the strings of BIOS table entry
 580                  */
 581                 if (str_starts_with(vendor, bt->vendor) &&
 582                                 str_starts_with(product, bt->product) &&
 583                                 str_starts_with(version, bt->version)) {
 584                         bios_cfg = bt;
 585                         break;
 586                 }
 587         }
 588
 589         if (!bios_cfg) {
 590                 pr_err("unknown (unsupported) BIOS version %s/%s/%s, "
 591                         "please report, aborting!\n", vendor, product, version);
 592                 return -EINVAL;
 593         }
 594
 595         /*
 596          * if started with kernel mode off, prevent the kernel from switching
 597          * off the fan
 598          */
 599         if (!kernelmode) {
 600                 pr_notice("Fan control off, to enable do:\n");
 601                 pr_notice("echo -n \"enabled\" > "
 602                         "/sys/class/thermal/thermal_zone0/mode\n");
 603         }
 604
 605         return 0;
 606 }
 607
 608 static int acerhdf_register_platform(void)
 609 {
 610         int err = 0;
 611
 612         err = platform_driver_register(&acerhdf_driver);
 613         if (err)
 614                 return err;
 615
 616         acerhdf_dev = platform_device_alloc("acerhdf", -1);
 617         if (!acerhdf_dev) {
 618                 err = -ENOMEM;
 619                 goto err_device_alloc;
 620         }
 621         err = platform_device_add(acerhdf_dev);
 622         if (err)
 623                 goto err_device_add;
 624
 625         return 0;
 626
 627 err_device_add:
 628         platform_device_put(acerhdf_dev);
 629 err_device_alloc:
 630         platform_driver_unregister(&acerhdf_driver);
 631         return err;
 632 }
 633
 634 static void acerhdf_unregister_platform(void)
 635 {
 636         platform_device_unregister(acerhdf_dev);
 637         platform_driver_unregister(&acerhdf_driver);
 638 }
 639
 640 static int acerhdf_register_thermal(void)
 641 {
 642         cl_dev = thermal_cooling_device_register("acerhdf-fan", NULL,
 643                                                  &acerhdf_cooling_ops);
 644
 645         if (IS_ERR(cl_dev))
 646                 return -EINVAL;
 647
 648         thz_dev = thermal_zone_device_register("acerhdf", 1, NULL,
 649                                               &acerhdf_dev_ops, 0, 0, 0,
 650                                               (kernelmode) ? interval*1000 : 0);
 651         if (IS_ERR(thz_dev))
 652                 return -EINVAL;
 653
 654         return 0;
 655 }
 656
 657 static void acerhdf_unregister_thermal(void)
 658 {
 659         if (cl_dev) {
 660                 thermal_cooling_device_unregister(cl_dev);
 661                 cl_dev = NULL;
 662         }
 663
 664         if (thz_dev) {
 665                 thermal_zone_device_unregister(thz_dev);
 666                 thz_dev = NULL;
 667         }
 668 }
 669
 670 static int __init acerhdf_init(void)
 671 {
 672         int err = 0;
 673
 674         err = acerhdf_check_hardware();
 675         if (err)
 676                 goto out_err;
 677
 678         err = acerhdf_register_platform();
 679         if (err)
 680                 goto out_err;
 681
 682         err = acerhdf_register_thermal();
 683         if (err)
 684                 goto err_unreg;
 685
 686         return 0;
 687
 688 err_unreg:
 689         acerhdf_unregister_thermal();
 690         acerhdf_unregister_platform();
 691
 692 out_err:
 693         return err;
 694 }
 695
 696 static void __exit acerhdf_exit(void)
 697 {
 698         acerhdf_change_fanstate(ACERHDF_FAN_AUTO);
 699         acerhdf_unregister_thermal();
 700         acerhdf_unregister_platform();
 701 }
 702
 703 MODULE_LICENSE("GPL");
 704 MODULE_AUTHOR("Peter Feuerer");
 705 MODULE_DESCRIPTION("Aspire One temperature and fan driver");
 706 MODULE_ALIAS("dmi:*:*Acer*:pnAOA*:");
 707 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1410*:");
 708 MODULE_ALIAS("dmi:*:*Acer*:pnAspire*1810*:");
 709 MODULE_ALIAS("dmi:*:*Acer*:pnAO531*:");
 710 MODULE_ALIAS("dmi:*:*Gateway*:pnAOA*:");
 711 MODULE_ALIAS("dmi:*:*Gateway*:pnLT31*:");
 712 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnAOA*:");
 713 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOA*:");
 714 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTMU*:");
 715 MODULE_ALIAS("dmi:*:*Packard*Bell*:pnDOTMA*:");
 716
 717 module_init(acerhdf_init);
 718 module_exit(acerhdf_exit);