drivers/char/i8k.c

   1 /*
   2  * i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
   3  *
   4  * Copyright (C) 2001  Massimo Dal Zotto <dz@debian.org>
   5  *
   6  * Hwmon integration:
   7  * Copyright (C) 2011  Jean Delvare <jdelvare@suse.de>
   8  * Copyright (C) 2013  Guenter Roeck <linux@roeck-us.net>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by the
  12  * Free Software Foundation; either version 2, or (at your option) any
  13  * later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  */
  20
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/module.h>
  24 #include <linux/types.h>
  25 #include <linux/init.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/dmi.h>
  29 #include <linux/capability.h>
  30 #include <linux/mutex.h>
  31 #include <linux/hwmon.h>
  32 #include <linux/hwmon-sysfs.h>
  33 #include <linux/uaccess.h>
  34 #include <linux/io.h>
  35 #include <linux/sched.h>
  36
  37 #include <linux/i8k.h>
  38
  39 #define I8K_SMM_FN_STATUS       0x0025
  40 #define I8K_SMM_POWER_STATUS    0x0069
  41 #define I8K_SMM_SET_FAN         0x01a3
  42 #define I8K_SMM_GET_FAN         0x00a3
  43 #define I8K_SMM_GET_SPEED       0x02a3
  44 #define I8K_SMM_GET_TEMP        0x10a3
  45 #define I8K_SMM_GET_DELL_SIG1   0xfea3
  46 #define I8K_SMM_GET_DELL_SIG2   0xffa3
  47
  48 #define I8K_FAN_MULT            30
  49 #define I8K_MAX_TEMP            127
  50
  51 #define I8K_FN_NONE             0x00
  52 #define I8K_FN_UP               0x01
  53 #define I8K_FN_DOWN             0x02
  54 #define I8K_FN_MUTE             0x04
  55 #define I8K_FN_MASK             0x07
  56 #define I8K_FN_SHIFT            8
  57
  58 #define I8K_POWER_AC            0x05
  59 #define I8K_POWER_BATTERY       0x01
  60
  61 #define I8K_TEMPERATURE_BUG     1
  62
  63 static DEFINE_MUTEX(i8k_mutex);
  64 static char bios_version[4];
  65 static char bios_machineid[16];
  66 static struct device *i8k_hwmon_dev;
  67 static u32 i8k_hwmon_flags;
  68 static int i8k_fan_mult;
  69
  70 #define I8K_HWMON_HAVE_TEMP1    (1 << 0)
  71 #define I8K_HWMON_HAVE_TEMP2    (1 << 1)
  72 #define I8K_HWMON_HAVE_TEMP3    (1 << 2)
  73 #define I8K_HWMON_HAVE_TEMP4    (1 << 3)
  74 #define I8K_HWMON_HAVE_FAN1     (1 << 4)
  75 #define I8K_HWMON_HAVE_FAN2     (1 << 5)
  76
  77 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
  78 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
  79 MODULE_LICENSE("GPL");
  80
  81 static bool force;
  82 module_param(force, bool, 0);
  83 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
  84
  85 static bool ignore_dmi;
  86 module_param(ignore_dmi, bool, 0);
  87 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
  88
  89 static bool restricted = true;
  90 module_param(restricted, bool, 0);
  91 MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
  92
  93 static bool power_status;
  94 module_param(power_status, bool, 0600);
  95 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
  96
  97 static int fan_mult = I8K_FAN_MULT;
  98 module_param(fan_mult, int, 0);
  99 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
 100
 101 static int i8k_open_fs(struct inode *inode, struct file *file);
 102 static long i8k_ioctl(struct file *, unsigned int, unsigned long);
 103
 104 static const struct file_operations i8k_fops = {
 105         .owner          = THIS_MODULE,
 106         .open           = i8k_open_fs,
 107         .read           = seq_read,
 108         .llseek         = seq_lseek,
 109         .release        = single_release,
 110         .unlocked_ioctl = i8k_ioctl,
 111 };
 112
 113 struct smm_regs {
 114         unsigned int eax;
 115         unsigned int ebx __packed;
 116         unsigned int ecx __packed;
 117         unsigned int edx __packed;
 118         unsigned int esi __packed;
 119         unsigned int edi __packed;
 120 };
 121
 122 static inline const char *i8k_get_dmi_data(int field)
 123 {
 124         const char *dmi_data = dmi_get_system_info(field);
 125
 126         return dmi_data && *dmi_data ? dmi_data : "?";
 127 }
 128
 129 /*
 130  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
 131  */
 132 static int i8k_smm(struct smm_regs *regs)
 133 {
 134         int rc;
 135         int eax = regs->eax;
 136         cpumask_var_t old_mask;
 137
 138         /* SMM requires CPU 0 */
 139         if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
 140                 return -ENOMEM;
 141         cpumask_copy(old_mask, &current->cpus_allowed);
 142         rc = set_cpus_allowed_ptr(current, cpumask_of(0));
 143         if (rc)
 144                 goto out;
 145         if (smp_processor_id() != 0) {
 146                 rc = -EBUSY;
 147                 goto out;
 148         }
 149
 150 #if defined(CONFIG_X86_64)
 151         asm volatile("pushq %%rax\n\t"
 152                 "movl 0(%%rax),%%edx\n\t"
 153                 "pushq %%rdx\n\t"
 154                 "movl 4(%%rax),%%ebx\n\t"
 155                 "movl 8(%%rax),%%ecx\n\t"
 156                 "movl 12(%%rax),%%edx\n\t"
 157                 "movl 16(%%rax),%%esi\n\t"
 158                 "movl 20(%%rax),%%edi\n\t"
 159                 "popq %%rax\n\t"
 160                 "out %%al,$0xb2\n\t"
 161                 "out %%al,$0x84\n\t"
 162                 "xchgq %%rax,(%%rsp)\n\t"
 163                 "movl %%ebx,4(%%rax)\n\t"
 164                 "movl %%ecx,8(%%rax)\n\t"
 165                 "movl %%edx,12(%%rax)\n\t"
 166                 "movl %%esi,16(%%rax)\n\t"
 167                 "movl %%edi,20(%%rax)\n\t"
 168                 "popq %%rdx\n\t"
 169                 "movl %%edx,0(%%rax)\n\t"
 170                 "pushfq\n\t"
 171                 "popq %%rax\n\t"
 172                 "andl $1,%%eax\n"
 173                 : "=a"(rc)
 174                 :    "a"(regs)
 175                 :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 176 #else
 177         asm volatile("pushl %%eax\n\t"
 178             "movl 0(%%eax),%%edx\n\t"
 179             "push %%edx\n\t"
 180             "movl 4(%%eax),%%ebx\n\t"
 181             "movl 8(%%eax),%%ecx\n\t"
 182             "movl 12(%%eax),%%edx\n\t"
 183             "movl 16(%%eax),%%esi\n\t"
 184             "movl 20(%%eax),%%edi\n\t"
 185             "popl %%eax\n\t"
 186             "out %%al,$0xb2\n\t"
 187             "out %%al,$0x84\n\t"
 188             "xchgl %%eax,(%%esp)\n\t"
 189             "movl %%ebx,4(%%eax)\n\t"
 190             "movl %%ecx,8(%%eax)\n\t"
 191             "movl %%edx,12(%%eax)\n\t"
 192             "movl %%esi,16(%%eax)\n\t"
 193             "movl %%edi,20(%%eax)\n\t"
 194             "popl %%edx\n\t"
 195             "movl %%edx,0(%%eax)\n\t"
 196             "lahf\n\t"
 197             "shrl $8,%%eax\n\t"
 198             "andl $1,%%eax\n"
 199             : "=a"(rc)
 200             :    "a"(regs)
 201             :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 202 #endif
 203         if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
 204                 rc = -EINVAL;
 205
 206 out:
 207         set_cpus_allowed_ptr(current, old_mask);
 208         free_cpumask_var(old_mask);
 209         return rc;
 210 }
 211
 212 /*
 213  * Read the Fn key status.
 214  */
 215 static int i8k_get_fn_status(void)
 216 {
 217         struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
 218         int rc;
 219
 220         rc = i8k_smm(&regs);
 221         if (rc < 0)
 222                 return rc;
 223
 224         switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 225         case I8K_FN_UP:
 226                 return I8K_VOL_UP;
 227         case I8K_FN_DOWN:
 228                 return I8K_VOL_DOWN;
 229         case I8K_FN_MUTE:
 230                 return I8K_VOL_MUTE;
 231         default:
 232                 return 0;
 233         }
 234 }
 235
 236 /*
 237  * Read the power status.
 238  */
 239 static int i8k_get_power_status(void)
 240 {
 241         struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
 242         int rc;
 243
 244         rc = i8k_smm(&regs);
 245         if (rc < 0)
 246                 return rc;
 247
 248         return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
 249 }
 250
 251 /*
 252  * Read the fan status.
 253  */
 254 static int i8k_get_fan_status(int fan)
 255 {
 256         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
 257
 258         regs.ebx = fan & 0xff;
 259         return i8k_smm(&regs) ? : regs.eax & 0xff;
 260 }
 261
 262 /*
 263  * Read the fan speed in RPM.
 264  */
 265 static int i8k_get_fan_speed(int fan)
 266 {
 267         struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
 268
 269         regs.ebx = fan & 0xff;
 270         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 271 }
 272
 273 /*
 274  * Set the fan speed (off, low, high). Returns the new fan status.
 275  */
 276 static int i8k_set_fan(int fan, int speed)
 277 {
 278         struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
 279
 280         speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
 281         regs.ebx = (fan & 0xff) | (speed << 8);
 282
 283         return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
 284 }
 285
 286 /*
 287  * Read the cpu temperature.
 288  */
 289 static int i8k_get_temp(int sensor)
 290 {
 291         struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
 292         int rc;
 293         int temp;
 294
 295 #ifdef I8K_TEMPERATURE_BUG
 296         static int prev[4];
 297 #endif
 298         regs.ebx = sensor & 0xff;
 299         rc = i8k_smm(&regs);
 300         if (rc < 0)
 301                 return rc;
 302
 303         temp = regs.eax & 0xff;
 304
 305 #ifdef I8K_TEMPERATURE_BUG
 306         /*
 307          * Sometimes the temperature sensor returns 0x99, which is out of range.
 308          * In this case we return (once) the previous cached value. For example:
 309          # 1003655137 00000058 00005a4b
 310          # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 311          # 1003655139 00000054 00005c52
 312          */
 313         if (temp > I8K_MAX_TEMP) {
 314                 temp = prev[sensor];
 315                 prev[sensor] = I8K_MAX_TEMP;
 316         } else {
 317                 prev[sensor] = temp;
 318         }
 319 #endif
 320
 321         return temp;
 322 }
 323
 324 static int i8k_get_dell_signature(int req_fn)
 325 {
 326         struct smm_regs regs = { .eax = req_fn, };
 327         int rc;
 328
 329         rc = i8k_smm(&regs);
 330         if (rc < 0)
 331                 return rc;
 332
 333         return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 334 }
 335
 336 static int
 337 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
 338 {
 339         int val = 0;
 340         int speed;
 341         unsigned char buff[16];
 342         int __user *argp = (int __user *)arg;
 343
 344         if (!argp)
 345                 return -EINVAL;
 346
 347         switch (cmd) {
 348         case I8K_BIOS_VERSION:
 349                 val = (bios_version[0] << 16) |
 350                                 (bios_version[1] << 8) | bios_version[2];
 351                 break;
 352
 353         case I8K_MACHINE_ID:
 354                 if (restricted && !capable(CAP_SYS_ADMIN))
 355                         return -EPERM;
 356
 357                 memset(buff, 0, sizeof(buff));
 358                 strlcpy(buff, bios_machineid, sizeof(buff));
 359                 break;
 360
 361         case I8K_FN_STATUS:
 362                 val = i8k_get_fn_status();
 363                 break;
 364
 365         case I8K_POWER_STATUS:
 366                 val = i8k_get_power_status();
 367                 break;
 368
 369         case I8K_GET_TEMP:
 370                 val = i8k_get_temp(0);
 371                 break;
 372
 373         case I8K_GET_SPEED:
 374                 if (copy_from_user(&val, argp, sizeof(int)))
 375                         return -EFAULT;
 376
 377                 val = i8k_get_fan_speed(val);
 378                 break;
 379
 380         case I8K_GET_FAN:
 381                 if (copy_from_user(&val, argp, sizeof(int)))
 382                         return -EFAULT;
 383
 384                 val = i8k_get_fan_status(val);
 385                 break;
 386
 387         case I8K_SET_FAN:
 388                 if (restricted && !capable(CAP_SYS_ADMIN))
 389                         return -EPERM;
 390
 391                 if (copy_from_user(&val, argp, sizeof(int)))
 392                         return -EFAULT;
 393
 394                 if (copy_from_user(&speed, argp + 1, sizeof(int)))
 395                         return -EFAULT;
 396
 397                 val = i8k_set_fan(val, speed);
 398                 break;
 399
 400         default:
 401                 return -EINVAL;
 402         }
 403
 404         if (val < 0)
 405                 return val;
 406
 407         switch (cmd) {
 408         case I8K_BIOS_VERSION:
 409                 if (copy_to_user(argp, &val, 4))
 410                         return -EFAULT;
 411
 412                 break;
 413         case I8K_MACHINE_ID:
 414                 if (copy_to_user(argp, buff, 16))
 415                         return -EFAULT;
 416
 417                 break;
 418         default:
 419                 if (copy_to_user(argp, &val, sizeof(int)))
 420                         return -EFAULT;
 421
 422                 break;
 423         }
 424
 425         return 0;
 426 }
 427
 428 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 429 {
 430         long ret;
 431
 432         mutex_lock(&i8k_mutex);
 433         ret = i8k_ioctl_unlocked(fp, cmd, arg);
 434         mutex_unlock(&i8k_mutex);
 435
 436         return ret;
 437 }
 438
 439 /*
 440  * Print the information for /proc/i8k.
 441  */
 442 static int i8k_proc_show(struct seq_file *seq, void *offset)
 443 {
 444         int fn_key, cpu_temp, ac_power;
 445         int left_fan, right_fan, left_speed, right_speed;
 446
 447         cpu_temp        = i8k_get_temp(0);                      /* 11100 µs */
 448         left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
 449         right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
 450         left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
 451         right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
 452         fn_key          = i8k_get_fn_status();                  /*   750 µs */
 453         if (power_status)
 454                 ac_power = i8k_get_power_status();              /* 14700 µs */
 455         else
 456                 ac_power = -1;
 457
 458         /*
 459          * Info:
 460          *
 461          * 1)  Format version (this will change if format changes)
 462          * 2)  BIOS version
 463          * 3)  BIOS machine ID
 464          * 4)  Cpu temperature
 465          * 5)  Left fan status
 466          * 6)  Right fan status
 467          * 7)  Left fan speed
 468          * 8)  Right fan speed
 469          * 9)  AC power
 470          * 10) Fn Key status
 471          */
 472         return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
 473                           I8K_PROC_FMT,
 474                           bios_version,
 475                           (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : bios_machineid,
 476                           cpu_temp,
 477                           left_fan, right_fan, left_speed, right_speed,
 478                           ac_power, fn_key);
 479 }
 480
 481 static int i8k_open_fs(struct inode *inode, struct file *file)
 482 {
 483         return single_open(file, i8k_proc_show, NULL);
 484 }
 485
 486
 487 /*
 488  * Hwmon interface
 489  */
 490
 491 static ssize_t i8k_hwmon_show_temp(struct device *dev,
 492                                    struct device_attribute *devattr,
 493                                    char *buf)
 494 {
 495         int index = to_sensor_dev_attr(devattr)->index;
 496         int temp;
 497
 498         temp = i8k_get_temp(index);
 499         if (temp < 0)
 500                 return temp;
 501         return sprintf(buf, "%d\n", temp * 1000);
 502 }
 503
 504 static ssize_t i8k_hwmon_show_fan(struct device *dev,
 505                                   struct device_attribute *devattr,
 506                                   char *buf)
 507 {
 508         int index = to_sensor_dev_attr(devattr)->index;
 509         int fan_speed;
 510
 511         fan_speed = i8k_get_fan_speed(index);
 512         if (fan_speed < 0)
 513                 return fan_speed;
 514         return sprintf(buf, "%d\n", fan_speed);
 515 }
 516
 517 static ssize_t i8k_hwmon_show_pwm(struct device *dev,
 518                                   struct device_attribute *devattr,
 519                                   char *buf)
 520 {
 521         int index = to_sensor_dev_attr(devattr)->index;
 522         int status;
 523
 524         status = i8k_get_fan_status(index);
 525         if (status < 0)
 526                 return -EIO;
 527         return sprintf(buf, "%d\n", clamp_val(status * 128, 0, 255));
 528 }
 529
 530 static ssize_t i8k_hwmon_set_pwm(struct device *dev,
 531                                  struct device_attribute *attr,
 532                                  const char *buf, size_t count)
 533 {
 534         int index = to_sensor_dev_attr(attr)->index;
 535         unsigned long val;
 536         int err;
 537
 538         err = kstrtoul(buf, 10, &val);
 539         if (err)
 540                 return err;
 541         val = clamp_val(DIV_ROUND_CLOSEST(val, 128), 0, 2);
 542
 543         mutex_lock(&i8k_mutex);
 544         err = i8k_set_fan(index, val);
 545         mutex_unlock(&i8k_mutex);
 546
 547         return err < 0 ? -EIO : count;
 548 }
 549
 550 static ssize_t i8k_hwmon_show_label(struct device *dev,
 551                                     struct device_attribute *devattr,
 552                                     char *buf)
 553 {
 554         static const char *labels[3] = {
 555                 "CPU",
 556                 "Left Fan",
 557                 "Right Fan",
 558         };
 559         int index = to_sensor_dev_attr(devattr)->index;
 560
 561         return sprintf(buf, "%s\n", labels[index]);
 562 }
 563
 564 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
 565 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
 566 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
 567 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
 568 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
 569                           I8K_FAN_LEFT);
 570 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 571                           i8k_hwmon_set_pwm, I8K_FAN_LEFT);
 572 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
 573                           I8K_FAN_RIGHT);
 574 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 575                           i8k_hwmon_set_pwm, I8K_FAN_RIGHT);
 576 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 0);
 577 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_label, NULL, 1);
 578 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_label, NULL, 2);
 579
 580 static struct attribute *i8k_attrs[] = {
 581         &sensor_dev_attr_temp1_input.dev_attr.attr,     /* 0 */
 582         &sensor_dev_attr_temp1_label.dev_attr.attr,     /* 1 */
 583         &sensor_dev_attr_temp2_input.dev_attr.attr,     /* 2 */
 584         &sensor_dev_attr_temp3_input.dev_attr.attr,     /* 3 */
 585         &sensor_dev_attr_temp4_input.dev_attr.attr,     /* 4 */
 586         &sensor_dev_attr_fan1_input.dev_attr.attr,      /* 5 */
 587         &sensor_dev_attr_pwm1.dev_attr.attr,            /* 6 */
 588         &sensor_dev_attr_fan1_label.dev_attr.attr,      /* 7 */
 589         &sensor_dev_attr_fan2_input.dev_attr.attr,      /* 8 */
 590         &sensor_dev_attr_pwm2.dev_attr.attr,            /* 9 */
 591         &sensor_dev_attr_fan2_label.dev_attr.attr,      /* 10 */
 592         NULL
 593 };
 594
 595 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
 596                               int index)
 597 {
 598         if ((index == 0 || index == 1) &&
 599             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
 600                 return 0;
 601         if (index == 2 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
 602                 return 0;
 603         if (index == 3 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
 604                 return 0;
 605         if (index == 4 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
 606                 return 0;
 607         if (index >= 5 && index <= 7 &&
 608             !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
 609                 return 0;
 610         if (index >= 8 && index <= 10 &&
 611             !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
 612                 return 0;
 613
 614         return attr->mode;
 615 }
 616
 617 static const struct attribute_group i8k_group = {
 618         .attrs = i8k_attrs,
 619         .is_visible = i8k_is_visible,
 620 };
 621 __ATTRIBUTE_GROUPS(i8k);
 622
 623 static int __init i8k_init_hwmon(void)
 624 {
 625         int err;
 626
 627         i8k_hwmon_flags = 0;
 628
 629         /* CPU temperature attributes, if temperature reading is OK */
 630         err = i8k_get_temp(0);
 631         if (err >= 0)
 632                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
 633         /* check for additional temperature sensors */
 634         err = i8k_get_temp(1);
 635         if (err >= 0)
 636                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
 637         err = i8k_get_temp(2);
 638         if (err >= 0)
 639                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
 640         err = i8k_get_temp(3);
 641         if (err >= 0)
 642                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
 643
 644         /* Left fan attributes, if left fan is present */
 645         err = i8k_get_fan_status(I8K_FAN_LEFT);
 646         if (err >= 0)
 647                 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
 648
 649         /* Right fan attributes, if right fan is present */
 650         err = i8k_get_fan_status(I8K_FAN_RIGHT);
 651         if (err >= 0)
 652                 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
 653
 654         i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
 655                                                           i8k_groups);
 656         if (IS_ERR(i8k_hwmon_dev)) {
 657                 err = PTR_ERR(i8k_hwmon_dev);
 658                 i8k_hwmon_dev = NULL;
 659                 pr_err("hwmon registration failed (%d)\n", err);
 660                 return err;
 661         }
 662         return 0;
 663 }
 664
 665 static struct dmi_system_id i8k_dmi_table[] __initdata = {
 666         {
 667                 .ident = "Dell Inspiron",
 668                 .matches = {
 669                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 670                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 671                 },
 672         },
 673         {
 674                 .ident = "Dell Latitude",
 675                 .matches = {
 676                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 677                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 678                 },
 679         },
 680         {
 681                 .ident = "Dell Inspiron 2",
 682                 .matches = {
 683                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 684                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 685                 },
 686         },
 687         {
 688                 .ident = "Dell Latitude 2",
 689                 .matches = {
 690                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 691                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 692                 },
 693         },
 694         {       /* UK Inspiron 6400  */
 695                 .ident = "Dell Inspiron 3",
 696                 .matches = {
 697                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 698                         DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
 699                 },
 700         },
 701         {
 702                 .ident = "Dell Inspiron 3",
 703                 .matches = {
 704                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 705                         DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
 706                 },
 707         },
 708         {
 709                 .ident = "Dell Precision",
 710                 .matches = {
 711                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 712                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
 713                 },
 714         },
 715         {
 716                 .ident = "Dell Vostro",
 717                 .matches = {
 718                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 719                         DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
 720                 },
 721         },
 722         {
 723                 .ident = "Dell XPS421",
 724                 .matches = {
 725                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 726                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
 727                 },
 728         },
 729         {
 730                 .ident = "Dell Studio",
 731                 .matches = {
 732                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 733                         DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
 734                 },
 735                 .driver_data = (void *)1,       /* fan multiplier override */
 736         },
 737         {
 738                 .ident = "Dell XPS M140",
 739                 .matches = {
 740                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 741                         DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
 742                 },
 743                 .driver_data = (void *)1,       /* fan multiplier override */
 744         },
 745         { }
 746 };
 747
 748 /*
 749  * Probe for the presence of a supported laptop.
 750  */
 751 static int __init i8k_probe(void)
 752 {
 753         const struct dmi_system_id *id;
 754
 755         /*
 756          * Get DMI information
 757          */
 758         if (!dmi_check_system(i8k_dmi_table)) {
 759                 if (!ignore_dmi && !force)
 760                         return -ENODEV;
 761
 762                 pr_info("not running on a supported Dell system.\n");
 763                 pr_info("vendor=%s, model=%s, version=%s\n",
 764                         i8k_get_dmi_data(DMI_SYS_VENDOR),
 765                         i8k_get_dmi_data(DMI_PRODUCT_NAME),
 766                         i8k_get_dmi_data(DMI_BIOS_VERSION));
 767         }
 768
 769         strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
 770                 sizeof(bios_version));
 771         strlcpy(bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
 772                 sizeof(bios_machineid));
 773
 774         /*
 775          * Get SMM Dell signature
 776          */
 777         if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
 778             i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
 779                 pr_err("unable to get SMM Dell signature\n");
 780                 if (!force)
 781                         return -ENODEV;
 782         }
 783
 784         i8k_fan_mult = fan_mult;
 785         id = dmi_first_match(i8k_dmi_table);
 786         if (id && fan_mult == I8K_FAN_MULT && id->driver_data)
 787                 i8k_fan_mult = (unsigned long)id->driver_data;
 788
 789         return 0;
 790 }
 791
 792 static int __init i8k_init(void)
 793 {
 794         struct proc_dir_entry *proc_i8k;
 795         int err;
 796
 797         /* Are we running on an supported laptop? */
 798         if (i8k_probe())
 799                 return -ENODEV;
 800
 801         /* Register the proc entry */
 802         proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
 803         if (!proc_i8k)
 804                 return -ENOENT;
 805
 806         err = i8k_init_hwmon();
 807         if (err)
 808                 goto exit_remove_proc;
 809
 810         return 0;
 811
 812  exit_remove_proc:
 813         remove_proc_entry("i8k", NULL);
 814         return err;
 815 }
 816
 817 static void __exit i8k_exit(void)
 818 {
 819         hwmon_device_unregister(i8k_hwmon_dev);
 820         remove_proc_entry("i8k", NULL);
 821 }
 822
 823 module_init(i8k_init);
 824 module_exit(i8k_exit);