drivers/char/i8k.c

   1 /*
   2  * i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
   3  *          See http://www.debian.org/~dz/i8k/ for more information
   4  *          and for latest version of this driver.
   5  *
   6  * Copyright (C) 2001  Massimo Dal Zotto <dz@debian.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the
  10  * Free Software Foundation; either version 2, or (at your option) any
  11  * later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/types.h>
  21 #include <linux/init.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/apm_bios.h>
  24 #include <asm/uaccess.h>
  25 #include <asm/io.h>
  26
  27 #include <linux/i8k.h>
  28
  29 #define I8K_VERSION             "1.13 14/05/2002"
  30
  31 #define I8K_SMM_FN_STATUS       0x0025
  32 #define I8K_SMM_POWER_STATUS    0x0069
  33 #define I8K_SMM_SET_FAN         0x01a3
  34 #define I8K_SMM_GET_FAN         0x00a3
  35 #define I8K_SMM_GET_SPEED       0x02a3
  36 #define I8K_SMM_GET_TEMP        0x10a3
  37 #define I8K_SMM_GET_DELL_SIG    0xffa3
  38 #define I8K_SMM_BIOS_VERSION    0x00a6
  39
  40 #define I8K_FAN_MULT            30
  41 #define I8K_MAX_TEMP            127
  42
  43 #define I8K_FN_NONE             0x00
  44 #define I8K_FN_UP               0x01
  45 #define I8K_FN_DOWN             0x02
  46 #define I8K_FN_MUTE             0x04
  47 #define I8K_FN_MASK             0x07
  48 #define I8K_FN_SHIFT            8
  49
  50 #define I8K_POWER_AC            0x05
  51 #define I8K_POWER_BATTERY       0x01
  52
  53 #define I8K_TEMPERATURE_BUG     1
  54
  55 #define DELL_SIGNATURE          "Dell Computer"
  56
  57 static char *supported_models[] = {
  58         "Inspiron",
  59         "Latitude",
  60         NULL
  61 };
  62
  63 static char system_vendor[48] = "?";
  64 static char product_name[48] = "?";
  65 static char bios_version[4] = "?";
  66 static char serial_number[16] = "?";
  67
  68 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
  69 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
  70 MODULE_LICENSE("GPL");
  71
  72 static int force;
  73 module_param(force, bool, 0);
  74 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
  75
  76 static int restricted;
  77 module_param(restricted, bool, 0);
  78 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
  79
  80 static int power_status;
  81 module_param(power_status, bool, 0600);
  82 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
  83
  84 static ssize_t i8k_read(struct file *, char __user *, size_t, loff_t *);
  85 static int i8k_ioctl(struct inode *, struct file *, unsigned int,
  86                      unsigned long);
  87
  88 static struct file_operations i8k_fops = {
  89         .read = i8k_read,
  90         .ioctl = i8k_ioctl,
  91 };
  92
  93 typedef struct {
  94         unsigned int eax;
  95         unsigned int ebx __attribute__ ((packed));
  96         unsigned int ecx __attribute__ ((packed));
  97         unsigned int edx __attribute__ ((packed));
  98         unsigned int esi __attribute__ ((packed));
  99         unsigned int edi __attribute__ ((packed));
 100 } SMMRegisters;
 101
 102 typedef struct {
 103         u8 type;
 104         u8 length;
 105         u16 handle;
 106 } DMIHeader;
 107
 108 /*
 109  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
 110  */
 111 static int i8k_smm(SMMRegisters * regs)
 112 {
 113         int rc;
 114         int eax = regs->eax;
 115
 116         asm("pushl %%eax\n\t"
 117             "movl 0(%%eax),%%edx\n\t"
 118             "push %%edx\n\t"
 119             "movl 4(%%eax),%%ebx\n\t"
 120             "movl 8(%%eax),%%ecx\n\t"
 121             "movl 12(%%eax),%%edx\n\t"
 122             "movl 16(%%eax),%%esi\n\t"
 123             "movl 20(%%eax),%%edi\n\t"
 124             "popl %%eax\n\t"
 125             "out %%al,$0xb2\n\t"
 126             "out %%al,$0x84\n\t"
 127             "xchgl %%eax,(%%esp)\n\t"
 128             "movl %%ebx,4(%%eax)\n\t"
 129             "movl %%ecx,8(%%eax)\n\t"
 130             "movl %%edx,12(%%eax)\n\t"
 131             "movl %%esi,16(%%eax)\n\t"
 132             "movl %%edi,20(%%eax)\n\t"
 133             "popl %%edx\n\t"
 134             "movl %%edx,0(%%eax)\n\t"
 135             "lahf\n\t"
 136             "shrl $8,%%eax\n\t"
 137             "andl $1,%%eax\n":"=a"(rc)
 138             :    "a"(regs)
 139             :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 140
 141         if ((rc != 0) || ((regs->eax & 0xffff) == 0xffff) || (regs->eax == eax)) {
 142                 return -EINVAL;
 143         }
 144
 145         return 0;
 146 }
 147
 148 /*
 149  * Read the bios version. Return the version as an integer corresponding
 150  * to the ascii value, for example "A17" is returned as 0x00413137.
 151  */
 152 static int i8k_get_bios_version(void)
 153 {
 154         SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 155         int rc;
 156
 157         regs.eax = I8K_SMM_BIOS_VERSION;
 158         if ((rc = i8k_smm(&regs)) < 0) {
 159                 return rc;
 160         }
 161
 162         return regs.eax;
 163 }
 164
 165 /*
 166  * Read the machine id.
 167  */
 168 static int i8k_get_serial_number(unsigned char *buff)
 169 {
 170         strlcpy(buff, serial_number, sizeof(serial_number));
 171         return 0;
 172 }
 173
 174 /*
 175  * Read the Fn key status.
 176  */
 177 static int i8k_get_fn_status(void)
 178 {
 179         SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 180         int rc;
 181
 182         regs.eax = I8K_SMM_FN_STATUS;
 183         if ((rc = i8k_smm(&regs)) < 0) {
 184                 return rc;
 185         }
 186
 187         switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 188         case I8K_FN_UP:
 189                 return I8K_VOL_UP;
 190         case I8K_FN_DOWN:
 191                 return I8K_VOL_DOWN;
 192         case I8K_FN_MUTE:
 193                 return I8K_VOL_MUTE;
 194         default:
 195                 return 0;
 196         }
 197 }
 198
 199 /*
 200  * Read the power status.
 201  */
 202 static int i8k_get_power_status(void)
 203 {
 204         SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 205         int rc;
 206
 207         regs.eax = I8K_SMM_POWER_STATUS;
 208         if ((rc = i8k_smm(&regs)) < 0) {
 209                 return rc;
 210         }
 211
 212         switch (regs.eax & 0xff) {
 213         case I8K_POWER_AC:
 214                 return I8K_AC;
 215         default:
 216                 return I8K_BATTERY;
 217         }
 218 }
 219
 220 /*
 221  * Read the fan status.
 222  */
 223 static int i8k_get_fan_status(int fan)
 224 {
 225         SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 226         int rc;
 227
 228         regs.eax = I8K_SMM_GET_FAN;
 229         regs.ebx = fan & 0xff;
 230         if ((rc = i8k_smm(&regs)) < 0) {
 231                 return rc;
 232         }
 233
 234         return (regs.eax & 0xff);
 235 }
 236
 237 /*
 238  * Read the fan speed in RPM.
 239  */
 240 static int i8k_get_fan_speed(int fan)
 241 {
 242         SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 243         int rc;
 244
 245         regs.eax = I8K_SMM_GET_SPEED;
 246         regs.ebx = fan & 0xff;
 247         if ((rc = i8k_smm(&regs)) < 0) {
 248                 return rc;
 249         }
 250
 251         return (regs.eax & 0xffff) * I8K_FAN_MULT;
 252 }
 253
 254 /*
 255  * Set the fan speed (off, low, high). Returns the new fan status.
 256  */
 257 static int i8k_set_fan(int fan, int speed)
 258 {
 259         SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 260         int rc;
 261
 262         speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
 263
 264         regs.eax = I8K_SMM_SET_FAN;
 265         regs.ebx = (fan & 0xff) | (speed << 8);
 266         if ((rc = i8k_smm(&regs)) < 0) {
 267                 return rc;
 268         }
 269
 270         return (i8k_get_fan_status(fan));
 271 }
 272
 273 /*
 274  * Read the cpu temperature.
 275  */
 276 static int i8k_get_cpu_temp(void)
 277 {
 278         SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 279         int rc;
 280         int temp;
 281
 282 #ifdef I8K_TEMPERATURE_BUG
 283         static int prev = 0;
 284 #endif
 285
 286         regs.eax = I8K_SMM_GET_TEMP;
 287         if ((rc = i8k_smm(&regs)) < 0) {
 288                 return rc;
 289         }
 290         temp = regs.eax & 0xff;
 291
 292 #ifdef I8K_TEMPERATURE_BUG
 293         /*
 294          * Sometimes the temperature sensor returns 0x99, which is out of range.
 295          * In this case we return (once) the previous cached value. For example:
 296          # 1003655137 00000058 00005a4b
 297          # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 298          # 1003655139 00000054 00005c52
 299          */
 300         if (temp > I8K_MAX_TEMP) {
 301                 temp = prev;
 302                 prev = I8K_MAX_TEMP;
 303         } else {
 304                 prev = temp;
 305         }
 306 #endif
 307
 308         return temp;
 309 }
 310
 311 static int i8k_get_dell_signature(void)
 312 {
 313         SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 314         int rc;
 315
 316         regs.eax = I8K_SMM_GET_DELL_SIG;
 317         if ((rc = i8k_smm(&regs)) < 0) {
 318                 return rc;
 319         }
 320
 321         if ((regs.eax == 1145651527) && (regs.edx == 1145392204)) {
 322                 return 0;
 323         } else {
 324                 return -1;
 325         }
 326 }
 327
 328 static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
 329                      unsigned long arg)
 330 {
 331         int val;
 332         int speed;
 333         unsigned char buff[16];
 334         int __user *argp = (int __user *)arg;
 335
 336         if (!argp)
 337                 return -EINVAL;
 338
 339         switch (cmd) {
 340         case I8K_BIOS_VERSION:
 341                 val = i8k_get_bios_version();
 342                 break;
 343
 344         case I8K_MACHINE_ID:
 345                 memset(buff, 0, 16);
 346                 val = i8k_get_serial_number(buff);
 347                 break;
 348
 349         case I8K_FN_STATUS:
 350                 val = i8k_get_fn_status();
 351                 break;
 352
 353         case I8K_POWER_STATUS:
 354                 val = i8k_get_power_status();
 355                 break;
 356
 357         case I8K_GET_TEMP:
 358                 val = i8k_get_cpu_temp();
 359                 break;
 360
 361         case I8K_GET_SPEED:
 362                 if (copy_from_user(&val, argp, sizeof(int))) {
 363                         return -EFAULT;
 364                 }
 365                 val = i8k_get_fan_speed(val);
 366                 break;
 367
 368         case I8K_GET_FAN:
 369                 if (copy_from_user(&val, argp, sizeof(int))) {
 370                         return -EFAULT;
 371                 }
 372                 val = i8k_get_fan_status(val);
 373                 break;
 374
 375         case I8K_SET_FAN:
 376                 if (restricted && !capable(CAP_SYS_ADMIN)) {
 377                         return -EPERM;
 378                 }
 379                 if (copy_from_user(&val, argp, sizeof(int))) {
 380                         return -EFAULT;
 381                 }
 382                 if (copy_from_user(&speed, argp + 1, sizeof(int))) {
 383                         return -EFAULT;
 384                 }
 385                 val = i8k_set_fan(val, speed);
 386                 break;
 387
 388         default:
 389                 return -EINVAL;
 390         }
 391
 392         if (val < 0) {
 393                 return val;
 394         }
 395
 396         switch (cmd) {
 397         case I8K_BIOS_VERSION:
 398                 if (copy_to_user(argp, &val, 4)) {
 399                         return -EFAULT;
 400                 }
 401                 break;
 402         case I8K_MACHINE_ID:
 403                 if (copy_to_user(argp, buff, 16)) {
 404                         return -EFAULT;
 405                 }
 406                 break;
 407         default:
 408                 if (copy_to_user(argp, &val, sizeof(int))) {
 409                         return -EFAULT;
 410                 }
 411                 break;
 412         }
 413
 414         return 0;
 415 }
 416
 417 /*
 418  * Print the information for /proc/i8k.
 419  */
 420 static int i8k_get_info(char *buffer, char **start, off_t fpos, int length)
 421 {
 422         int n, fn_key, cpu_temp, ac_power;
 423         int left_fan, right_fan, left_speed, right_speed;
 424
 425         cpu_temp        = i8k_get_cpu_temp();                   /* 11100 µs */
 426         left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
 427         right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
 428         left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
 429         right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
 430         fn_key          = i8k_get_fn_status();                  /*   750 µs */
 431         if (power_status) {
 432                 ac_power = i8k_get_power_status();              /* 14700 µs */
 433         } else {
 434                 ac_power = -1;
 435         }
 436
 437         /*
 438          * Info:
 439          *
 440          * 1)  Format version (this will change if format changes)
 441          * 2)  BIOS version
 442          * 3)  BIOS machine ID
 443          * 4)  Cpu temperature
 444          * 5)  Left fan status
 445          * 6)  Right fan status
 446          * 7)  Left fan speed
 447          * 8)  Right fan speed
 448          * 9)  AC power
 449          * 10) Fn Key status
 450          */
 451         n = sprintf(buffer, "%s %s %s %d %d %d %d %d %d %d\n",
 452                     I8K_PROC_FMT,
 453                     bios_version,
 454                     serial_number,
 455                     cpu_temp,
 456                     left_fan,
 457                     right_fan, left_speed, right_speed, ac_power, fn_key);
 458
 459         return n;
 460 }
 461
 462 static ssize_t i8k_read(struct file *f, char __user * buffer, size_t len,
 463                         loff_t * fpos)
 464 {
 465         int n;
 466         char info[128];
 467
 468         n = i8k_get_info(info, NULL, 0, 128);
 469         if (n <= 0) {
 470                 return n;
 471         }
 472
 473         if (*fpos >= n) {
 474                 return 0;
 475         }
 476
 477         if ((*fpos + len) >= n) {
 478                 len = n - *fpos;
 479         }
 480
 481         if (copy_to_user(buffer, info, len) != 0) {
 482                 return -EFAULT;
 483         }
 484
 485         *fpos += len;
 486         return len;
 487 }
 488
 489 static char *__init string_trim(char *s, int size)
 490 {
 491         int len;
 492         char *p;
 493
 494         if ((len = strlen(s)) > size) {
 495                 len = size;
 496         }
 497
 498         for (p = s + len - 1; len && (*p == ' '); len--, p--) {
 499                 *p = '\0';
 500         }
 501
 502         return s;
 503 }
 504
 505 /* DMI code, stolen from arch/i386/kernel/dmi_scan.c */
 506
 507 /*
 508  * |<-- dmi->length -->|
 509  * |                   |
 510  * |dmi header    s=N  | string1,\0, ..., stringN,\0, ..., \0
 511  *                |                       |
 512  *                +-----------------------+
 513  */
 514 static char *__init dmi_string(DMIHeader * dmi, u8 s)
 515 {
 516         u8 *p;
 517
 518         if (!s) {
 519                 return "";
 520         }
 521         s--;
 522
 523         p = (u8 *) dmi + dmi->length;
 524         while (s > 0) {
 525                 p += strlen(p);
 526                 p++;
 527                 s--;
 528         }
 529
 530         return p;
 531 }
 532
 533 static void __init dmi_decode(DMIHeader * dmi)
 534 {
 535         u8 *data = (u8 *) dmi;
 536         char *p;
 537
 538 #ifdef I8K_DEBUG
 539         int i;
 540         printk("%08x ", (int)data);
 541         for (i = 0; i < data[1] && i < 64; i++) {
 542                 printk("%02x ", data[i]);
 543         }
 544         printk("\n");
 545 #endif
 546
 547         switch (dmi->type) {
 548         case 0:         /* BIOS Information */
 549                 p = dmi_string(dmi, data[5]);
 550                 if (*p) {
 551                         strlcpy(bios_version, p, sizeof(bios_version));
 552                         string_trim(bios_version, sizeof(bios_version));
 553                 }
 554                 break;
 555         case 1:         /* System Information */
 556                 p = dmi_string(dmi, data[4]);
 557                 if (*p) {
 558                         strlcpy(system_vendor, p, sizeof(system_vendor));
 559                         string_trim(system_vendor, sizeof(system_vendor));
 560                 }
 561                 p = dmi_string(dmi, data[5]);
 562                 if (*p) {
 563                         strlcpy(product_name, p, sizeof(product_name));
 564                         string_trim(product_name, sizeof(product_name));
 565                 }
 566                 p = dmi_string(dmi, data[7]);
 567                 if (*p) {
 568                         strlcpy(serial_number, p, sizeof(serial_number));
 569                         string_trim(serial_number, sizeof(serial_number));
 570                 }
 571                 break;
 572         }
 573 }
 574
 575 static int __init dmi_table(u32 base, int len, int num,
 576                             void (*fn) (DMIHeader *))
 577 {
 578         u8 *buf;
 579         u8 *data;
 580         DMIHeader *dmi;
 581         int i = 1;
 582
 583         buf = ioremap(base, len);
 584         if (buf == NULL) {
 585                 return -1;
 586         }
 587         data = buf;
 588
 589         /*
 590          * Stop when we see al the items the table claimed to have
 591          * or we run off the end of the table (also happens)
 592          */
 593         while ((i < num) && ((data - buf) < len)) {
 594                 dmi = (DMIHeader *) data;
 595                 /*
 596                  * Avoid misparsing crud if the length of the last
 597                  * record is crap
 598                  */
 599                 if ((data - buf + dmi->length) >= len) {
 600                         break;
 601                 }
 602                 fn(dmi);
 603                 data += dmi->length;
 604                 /*
 605                  * Don't go off the end of the data if there is
 606                  * stuff looking like string fill past the end
 607                  */
 608                 while (((data - buf) < len) && (*data || data[1])) {
 609                         data++;
 610                 }
 611                 data += 2;
 612                 i++;
 613         }
 614         iounmap(buf);
 615
 616         return 0;
 617 }
 618
 619 static int __init dmi_iterate(void (*decode) (DMIHeader *))
 620 {
 621         unsigned char buf[20];
 622         void __iomem *p = ioremap(0xe0000, 0x20000), *q;
 623
 624         if (!p)
 625                 return -1;
 626
 627         for (q = p; q < p + 0x20000; q += 16) {
 628                 memcpy_fromio(buf, q, 20);
 629                 if (memcmp(buf, "_DMI_", 5) == 0) {
 630                         u16 num  = buf[13] << 8 | buf[12];
 631                         u16 len  = buf[7] << 8 | buf[6];
 632                         u32 base = buf[11] << 24 | buf[10] << 16 | buf[9] << 8 | buf[8];
 633 #ifdef I8K_DEBUG
 634                         printk(KERN_INFO "DMI %d.%d present.\n",
 635                                buf[14] >> 4, buf[14] & 0x0F);
 636                         printk(KERN_INFO "%d structures occupying %d bytes.\n",
 637                                buf[13] << 8 | buf[12], buf[7] << 8 | buf[6]);
 638                         printk(KERN_INFO "DMI table at 0x%08X.\n",
 639                                buf[11] << 24 | buf[10] << 16 | buf[9] << 8 |
 640                                buf[8]);
 641 #endif
 642                         if (dmi_table(base, len, num, decode) == 0) {
 643                                 iounmap(p);
 644                                 return 0;
 645                         }
 646                 }
 647         }
 648         iounmap(p);
 649         return -1;
 650 }
 651
 652 /* end of DMI code */
 653
 654 /*
 655  * Get DMI information.
 656  */
 657 static int __init i8k_dmi_probe(void)
 658 {
 659         char **p;
 660
 661         if (dmi_iterate(dmi_decode) != 0) {
 662                 printk(KERN_INFO "i8k: unable to get DMI information\n");
 663                 return -ENODEV;
 664         }
 665
 666         if (strncmp(system_vendor, DELL_SIGNATURE, strlen(DELL_SIGNATURE)) != 0) {
 667                 printk(KERN_INFO "i8k: not running on a Dell system\n");
 668                 return -ENODEV;
 669         }
 670
 671         for (p = supported_models;; p++) {
 672                 if (!*p) {
 673                         printk(KERN_INFO "i8k: unsupported model: %s\n",
 674                                product_name);
 675                         return -ENODEV;
 676                 }
 677                 if (strncmp(product_name, *p, strlen(*p)) == 0) {
 678                         break;
 679                 }
 680         }
 681
 682         return 0;
 683 }
 684
 685 /*
 686  * Probe for the presence of a supported laptop.
 687  */
 688 static int __init i8k_probe(void)
 689 {
 690         char buff[4];
 691         int version;
 692         int smm_found = 0;
 693
 694         /*
 695          * Get DMI information
 696          */
 697         if (i8k_dmi_probe() != 0) {
 698                 printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
 699                        system_vendor, product_name, bios_version);
 700         }
 701
 702         /*
 703          * Get SMM Dell signature
 704          */
 705         if (i8k_get_dell_signature() != 0) {
 706                 printk(KERN_INFO "i8k: unable to get SMM Dell signature\n");
 707         } else {
 708                 smm_found = 1;
 709         }
 710
 711         /*
 712          * Get SMM BIOS version.
 713          */
 714         version = i8k_get_bios_version();
 715         if (version <= 0) {
 716                 printk(KERN_INFO "i8k: unable to get SMM BIOS version\n");
 717         } else {
 718                 smm_found = 1;
 719                 buff[0] = (version >> 16) & 0xff;
 720                 buff[1] = (version >> 8) & 0xff;
 721                 buff[2] = (version) & 0xff;
 722                 buff[3] = '\0';
 723                 /*
 724                  * If DMI BIOS version is unknown use SMM BIOS version.
 725                  */
 726                 if (bios_version[0] == '?') {
 727                         strcpy(bios_version, buff);
 728                 }
 729                 /*
 730                  * Check if the two versions match.
 731                  */
 732                 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0) {
 733                         printk(KERN_INFO
 734                                "i8k: BIOS version mismatch: %s != %s\n", buff,
 735                                bios_version);
 736                 }
 737         }
 738
 739         if (!smm_found && !force) {
 740                 return -ENODEV;
 741         }
 742
 743         return 0;
 744 }
 745
 746 #ifdef MODULE
 747 static
 748 #endif
 749 int __init i8k_init(void)
 750 {
 751         struct proc_dir_entry *proc_i8k;
 752
 753         /* Are we running on an supported laptop? */
 754         if (i8k_probe() != 0) {
 755                 return -ENODEV;
 756         }
 757
 758         /* Register the proc entry */
 759         proc_i8k = create_proc_info_entry("i8k", 0, NULL, i8k_get_info);
 760         if (!proc_i8k) {
 761                 return -ENOENT;
 762         }
 763         proc_i8k->proc_fops = &i8k_fops;
 764         proc_i8k->owner = THIS_MODULE;
 765
 766         printk(KERN_INFO
 767                "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
 768                I8K_VERSION);
 769
 770         return 0;
 771 }
 772
 773 #ifdef MODULE
 774 int init_module(void)
 775 {
 776         return i8k_init();
 777 }
 778
 779 void cleanup_module(void)
 780 {
 781         /* Remove the proc entry */
 782         remove_proc_entry("i8k", NULL);
 783
 784         printk(KERN_INFO "i8k: module unloaded\n");
 785 }
 786 #endif
 787
 788 /* end of file */