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" \
 138         : "=a" (rc)
 139         : "a" (regs)
 140         : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 141
 142     if ((rc != 0) || ((regs->eax & 0xffff) == 0xffff) || (regs->eax == eax)) {
 143         return -EINVAL;
 144     }
 145
 146     return 0;
 147 }
 148
 149 /*
 150  * Read the bios version. Return the version as an integer corresponding
 151  * to the ascii value, for example "A17" is returned as 0x00413137.
 152  */
 153 static int i8k_get_bios_version(void)
 154 {
 155     SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 156     int rc;
 157
 158     regs.eax = I8K_SMM_BIOS_VERSION;
 159     if ((rc=i8k_smm(&regs)) < 0) {
 160         return rc;
 161     }
 162
 163     return regs.eax;
 164 }
 165
 166 /*
 167  * Read the machine id.
 168  */
 169 static int i8k_get_serial_number(unsigned char *buff)
 170 {
 171     strlcpy(buff, serial_number, sizeof(serial_number));
 172     return 0;
 173 }
 174
 175 /*
 176  * Read the Fn key status.
 177  */
 178 static int i8k_get_fn_status(void)
 179 {
 180     SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 181     int rc;
 182
 183     regs.eax = I8K_SMM_FN_STATUS;
 184     if ((rc=i8k_smm(&regs)) < 0) {
 185         return rc;
 186     }
 187
 188     switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 189     case I8K_FN_UP:
 190         return I8K_VOL_UP;
 191     case I8K_FN_DOWN:
 192         return I8K_VOL_DOWN;
 193     case I8K_FN_MUTE:
 194         return I8K_VOL_MUTE;
 195     default:
 196         return 0;
 197     }
 198 }
 199
 200 /*
 201  * Read the power status.
 202  */
 203 static int i8k_get_power_status(void)
 204 {
 205     SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 206     int rc;
 207
 208     regs.eax = I8K_SMM_POWER_STATUS;
 209     if ((rc=i8k_smm(&regs)) < 0) {
 210         return rc;
 211     }
 212
 213     switch (regs.eax & 0xff) {
 214     case I8K_POWER_AC:
 215         return I8K_AC;
 216     default:
 217         return I8K_BATTERY;
 218     }
 219 }
 220
 221 /*
 222  * Read the fan status.
 223  */
 224 static int i8k_get_fan_status(int fan)
 225 {
 226     SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 227     int rc;
 228
 229     regs.eax = I8K_SMM_GET_FAN;
 230     regs.ebx = fan & 0xff;
 231     if ((rc=i8k_smm(&regs)) < 0) {
 232         return rc;
 233     }
 234
 235     return (regs.eax & 0xff);
 236 }
 237
 238 /*
 239  * Read the fan speed in RPM.
 240  */
 241 static int i8k_get_fan_speed(int fan)
 242 {
 243     SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 244     int rc;
 245
 246     regs.eax = I8K_SMM_GET_SPEED;
 247     regs.ebx = fan & 0xff;
 248     if ((rc=i8k_smm(&regs)) < 0) {
 249         return rc;
 250     }
 251
 252     return (regs.eax & 0xffff) * I8K_FAN_MULT;
 253 }
 254
 255 /*
 256  * Set the fan speed (off, low, high). Returns the new fan status.
 257  */
 258 static int i8k_set_fan(int fan, int speed)
 259 {
 260     SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 261     int rc;
 262
 263     speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
 264
 265     regs.eax = I8K_SMM_SET_FAN;
 266     regs.ebx = (fan & 0xff) | (speed << 8);
 267     if ((rc=i8k_smm(&regs)) < 0) {
 268         return rc;
 269     }
 270
 271     return (i8k_get_fan_status(fan));
 272 }
 273
 274 /*
 275  * Read the cpu temperature.
 276  */
 277 static int i8k_get_cpu_temp(void)
 278 {
 279     SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 280     int rc;
 281     int temp;
 282
 283 #ifdef I8K_TEMPERATURE_BUG
 284     static int prev = 0;
 285 #endif
 286
 287     regs.eax = I8K_SMM_GET_TEMP;
 288     if ((rc=i8k_smm(&regs)) < 0) {
 289         return rc;
 290     }
 291     temp = regs.eax & 0xff;
 292
 293 #ifdef I8K_TEMPERATURE_BUG
 294     /*
 295      * Sometimes the temperature sensor returns 0x99, which is out of range.
 296      * In this case we return (once) the previous cached value. For example:
 297      # 1003655137 00000058 00005a4b
 298      # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 299      # 1003655139 00000054 00005c52
 300      */
 301     if (temp > I8K_MAX_TEMP) {
 302         temp = prev;
 303         prev = I8K_MAX_TEMP;
 304     } else {
 305         prev = temp;
 306     }
 307 #endif
 308
 309     return temp;
 310 }
 311
 312 static int i8k_get_dell_signature(void)
 313 {
 314     SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
 315     int rc;
 316
 317     regs.eax = I8K_SMM_GET_DELL_SIG;
 318     if ((rc=i8k_smm(&regs)) < 0) {
 319         return rc;
 320     }
 321
 322     if ((regs.eax == 1145651527) && (regs.edx == 1145392204)) {
 323         return 0;
 324     } else {
 325         return -1;
 326     }
 327 }
 328
 329 static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
 330                      unsigned long arg)
 331 {
 332     int val;
 333     int speed;
 334     unsigned char buff[16];
 335     int __user *argp = (int __user *)arg;
 336
 337     if (!argp)
 338         return -EINVAL;
 339
 340     switch (cmd) {
 341     case I8K_BIOS_VERSION:
 342         val = i8k_get_bios_version();
 343         break;
 344
 345     case I8K_MACHINE_ID:
 346         memset(buff, 0, 16);
 347         val = i8k_get_serial_number(buff);
 348         break;
 349
 350     case I8K_FN_STATUS:
 351         val = i8k_get_fn_status();
 352         break;
 353
 354     case I8K_POWER_STATUS:
 355         val = i8k_get_power_status();
 356         break;
 357
 358     case I8K_GET_TEMP:
 359         val = i8k_get_cpu_temp();
 360         break;
 361
 362     case I8K_GET_SPEED:
 363         if (copy_from_user(&val, argp, sizeof(int))) {
 364             return -EFAULT;
 365         }
 366         val = i8k_get_fan_speed(val);
 367         break;
 368
 369     case I8K_GET_FAN:
 370         if (copy_from_user(&val, argp, sizeof(int))) {
 371             return -EFAULT;
 372         }
 373         val = i8k_get_fan_status(val);
 374         break;
 375
 376     case I8K_SET_FAN:
 377         if (restricted && !capable(CAP_SYS_ADMIN)) {
 378             return -EPERM;
 379         }
 380         if (copy_from_user(&val, argp, sizeof(int))) {
 381             return -EFAULT;
 382         }
 383         if (copy_from_user(&speed, argp+1, sizeof(int))) {
 384             return -EFAULT;
 385         }
 386         val = i8k_set_fan(val, speed);
 387         break;
 388
 389     default:
 390         return -EINVAL;
 391     }
 392
 393     if (val < 0) {
 394         return val;
 395     }
 396
 397     switch (cmd) {
 398     case I8K_BIOS_VERSION:
 399         if (copy_to_user(argp, &val, 4)) {
 400             return -EFAULT;
 401         }
 402         break;
 403     case I8K_MACHINE_ID:
 404         if (copy_to_user(argp, buff, 16)) {
 405             return -EFAULT;
 406         }
 407         break;
 408     default:
 409         if (copy_to_user(argp, &val, sizeof(int))) {
 410             return -EFAULT;
 411         }
 412         break;
 413     }
 414
 415     return 0;
 416 }
 417
 418 /*
 419  * Print the information for /proc/i8k.
 420  */
 421 static int i8k_get_info(char *buffer, char **start, off_t fpos, int length)
 422 {
 423     int n, fn_key, cpu_temp, ac_power;
 424     int left_fan, right_fan, left_speed, right_speed;
 425
 426     cpu_temp     = i8k_get_cpu_temp();                  /* 11100 µs */
 427     left_fan     = i8k_get_fan_status(I8K_FAN_LEFT);    /*   580 µs */
 428     right_fan    = i8k_get_fan_status(I8K_FAN_RIGHT);   /*   580 µs */
 429     left_speed   = i8k_get_fan_speed(I8K_FAN_LEFT);     /*   580 µs */
 430     right_speed  = i8k_get_fan_speed(I8K_FAN_RIGHT);    /*   580 µs */
 431     fn_key       = i8k_get_fn_status();                 /*   750 µs */
 432     if (power_status) {
 433         ac_power = i8k_get_power_status();              /* 14700 µs */
 434     } else {
 435         ac_power = -1;
 436     }
 437
 438     /*
 439      * Info:
 440      *
 441      * 1)  Format version (this will change if format changes)
 442      * 2)  BIOS version
 443      * 3)  BIOS machine ID
 444      * 4)  Cpu temperature
 445      * 5)  Left fan status
 446      * 6)  Right fan status
 447      * 7)  Left fan speed
 448      * 8)  Right fan speed
 449      * 9)  AC power
 450      * 10) Fn Key status
 451      */
 452     n = sprintf(buffer, "%s %s %s %d %d %d %d %d %d %d\n",
 453                 I8K_PROC_FMT,
 454                 bios_version,
 455                 serial_number,
 456                 cpu_temp,
 457                 left_fan,
 458                 right_fan,
 459                 left_speed,
 460                 right_speed,
 461                 ac_power,
 462                 fn_key);
 463
 464     return n;
 465 }
 466
 467 static ssize_t i8k_read(struct file *f, char __user *buffer, size_t len, loff_t *fpos)
 468 {
 469     int n;
 470     char info[128];
 471
 472     n = i8k_get_info(info, NULL, 0, 128);
 473     if (n <= 0) {
 474         return n;
 475     }
 476
 477     if (*fpos >= n) {
 478         return 0;
 479     }
 480
 481     if ((*fpos + len) >= n) {
 482         len = n - *fpos;
 483     }
 484
 485     if (copy_to_user(buffer, info, len) != 0) {
 486         return -EFAULT;
 487     }
 488
 489     *fpos += len;
 490     return len;
 491 }
 492
 493 static char* __init string_trim(char *s, int size)
 494 {
 495     int len;
 496     char *p;
 497
 498     if ((len = strlen(s)) > size) {
 499         len = size;
 500     }
 501
 502     for (p=s+len-1; len && (*p==' '); len--,p--) {
 503         *p = '\0';
 504     }
 505
 506     return s;
 507 }
 508
 509 /* DMI code, stolen from arch/i386/kernel/dmi_scan.c */
 510
 511 /*
 512  * |<-- dmi->length -->|
 513  * |                   |
 514  * |dmi header    s=N  | string1,\0, ..., stringN,\0, ..., \0
 515  *                |                       |
 516  *                +-----------------------+
 517  */
 518 static char* __init dmi_string(DMIHeader *dmi, u8 s)
 519 {
 520     u8 *p;
 521
 522     if (!s) {
 523         return "";
 524     }
 525     s--;
 526
 527     p = (u8 *)dmi + dmi->length;
 528     while (s > 0) {
 529         p += strlen(p);
 530         p++;
 531         s--;
 532     }
 533
 534     return p;
 535 }
 536
 537 static void __init dmi_decode(DMIHeader *dmi)
 538 {
 539     u8 *data = (u8 *) dmi;
 540     char *p;
 541
 542 #ifdef I8K_DEBUG
 543     int i;
 544     printk("%08x ", (int)data);
 545     for (i=0; i<data[1] && i<64; i++) {
 546         printk("%02x ", data[i]);
 547     }
 548     printk("\n");
 549 #endif
 550
 551     switch (dmi->type) {
 552     case  0:    /* BIOS Information */
 553         p = dmi_string(dmi,data[5]);
 554         if (*p) {
 555             strlcpy(bios_version, p, sizeof(bios_version));
 556             string_trim(bios_version, sizeof(bios_version));
 557         }
 558         break;
 559     case 1:     /* System Information */
 560         p = dmi_string(dmi,data[4]);
 561         if (*p) {
 562             strlcpy(system_vendor, p, sizeof(system_vendor));
 563             string_trim(system_vendor, sizeof(system_vendor));
 564         }
 565         p = dmi_string(dmi,data[5]);
 566         if (*p) {
 567             strlcpy(product_name, p, sizeof(product_name));
 568             string_trim(product_name, sizeof(product_name));
 569         }
 570         p = dmi_string(dmi,data[7]);
 571         if (*p) {
 572             strlcpy(serial_number, p, sizeof(serial_number));
 573             string_trim(serial_number, sizeof(serial_number));
 574         }
 575         break;
 576     }
 577 }
 578
 579 static int __init dmi_table(u32 base, int len, int num, void (*fn)(DMIHeader*))
 580 {
 581     u8 *buf;
 582     u8 *data;
 583     DMIHeader *dmi;
 584     int i = 1;
 585
 586     buf = ioremap(base, len);
 587     if (buf == NULL) {
 588         return -1;
 589     }
 590     data = buf;
 591
 592     /*
 593      * Stop when we see al the items the table claimed to have
 594      * or we run off the end of the table (also happens)
 595      */
 596     while ((i<num) && ((data-buf) < len)) {
 597         dmi = (DMIHeader *)data;
 598         /*
 599          * Avoid misparsing crud if the length of the last
 600          * record is crap
 601          */
 602         if ((data-buf+dmi->length) >= len) {
 603             break;
 604         }
 605         fn(dmi);
 606         data += dmi->length;
 607         /*
 608          * Don't go off the end of the data if there is
 609          * stuff looking like string fill past the end
 610          */
 611         while (((data-buf) < len) && (*data || data[1])) {
 612             data++;
 613         }
 614         data += 2;
 615         i++;
 616     }
 617     iounmap(buf);
 618
 619     return 0;
 620 }
 621
 622 static int __init dmi_iterate(void (*decode)(DMIHeader *))
 623 {
 624         unsigned char buf[20];
 625         void __iomem *p = ioremap(0xe0000, 0x20000), *q;
 626
 627         if (!p)
 628                 return -1;
 629
 630         for (q = p; q < p + 0x20000; q += 16) {
 631                 memcpy_fromio(buf, q, 20);
 632                 if (memcmp(buf, "_DMI_", 5)==0) {
 633                         u16 num  = buf[13]<<8  | buf[12];
 634                         u16 len  = buf [7]<<8  | buf [6];
 635                         u32 base = buf[11]<<24 | buf[10]<<16 | buf[9]<<8 | buf[8];
 636 #ifdef I8K_DEBUG
 637                         printk(KERN_INFO "DMI %d.%d present.\n",
 638                            buf[14]>>4, buf[14]&0x0F);
 639                         printk(KERN_INFO "%d structures occupying %d bytes.\n",
 640                            buf[13]<<8 | buf[12],
 641                            buf [7]<<8 | buf[6]);
 642                         printk(KERN_INFO "DMI table at 0x%08X.\n",
 643                            buf[11]<<24 | buf[10]<<16 | buf[9]<<8 | buf[8]);
 644 #endif
 645                         if (dmi_table(base, len, num, decode)==0) {
 646                                 iounmap(p);
 647                                 return 0;
 648                         }
 649                 }
 650         }
 651         iounmap(p);
 652         return -1;
 653 }
 654 /* end of DMI code */
 655
 656 /*
 657  * Get DMI information.
 658  */
 659 static int __init i8k_dmi_probe(void)
 660 {
 661     char **p;
 662
 663     if (dmi_iterate(dmi_decode) != 0) {
 664         printk(KERN_INFO "i8k: unable to get DMI information\n");
 665         return -ENODEV;
 666     }
 667
 668     if (strncmp(system_vendor,DELL_SIGNATURE,strlen(DELL_SIGNATURE)) != 0) {
 669         printk(KERN_INFO "i8k: not running on a Dell system\n");
 670         return -ENODEV;
 671     }
 672
 673     for (p=supported_models; ; p++) {
 674         if (!*p) {
 675             printk(KERN_INFO "i8k: unsupported model: %s\n", product_name);
 676             return -ENODEV;
 677         }
 678         if (strncmp(product_name,*p,strlen(*p)) == 0) {
 679             break;
 680         }
 681     }
 682
 683     return 0;
 684 }
 685
 686 /*
 687  * Probe for the presence of a supported laptop.
 688  */
 689 static int __init i8k_probe(void)
 690 {
 691     char buff[4];
 692     int version;
 693     int smm_found = 0;
 694
 695     /*
 696      * Get DMI information
 697      */
 698     if (i8k_dmi_probe() != 0) {
 699         printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
 700                system_vendor, product_name, bios_version);
 701     }
 702
 703     /*
 704      * Get SMM Dell signature
 705      */
 706     if (i8k_get_dell_signature() != 0) {
 707         printk(KERN_INFO "i8k: unable to get SMM Dell signature\n");
 708     } else {
 709         smm_found = 1;
 710     }
 711
 712     /*
 713      * Get SMM BIOS version.
 714      */
 715     version = i8k_get_bios_version();
 716     if (version <= 0) {
 717         printk(KERN_INFO "i8k: unable to get SMM BIOS version\n");
 718     } else {
 719         smm_found = 1;
 720         buff[0] = (version >> 16) & 0xff;
 721         buff[1] = (version >>  8) & 0xff;
 722         buff[2] = (version)       & 0xff;
 723         buff[3] = '\0';
 724         /*
 725          * If DMI BIOS version is unknown use SMM BIOS version.
 726          */
 727         if (bios_version[0] == '?') {
 728             strcpy(bios_version, buff);
 729         }
 730         /*
 731          * Check if the two versions match.
 732          */
 733         if (strncmp(buff,bios_version,sizeof(bios_version)) != 0) {
 734             printk(KERN_INFO "i8k: BIOS version mismatch: %s != %s\n",
 735                    buff, 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 */