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, 2014  Guenter Roeck <linux@roeck-us.net>
   9  * Copyright (C) 2014  Pali Rohár <pali.rohar@gmail.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the
  13  * Free Software Foundation; either version 2, or (at your option) any
  14  * later version.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  */
  21
  22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/delay.h>
  25 #include <linux/module.h>
  26 #include <linux/types.h>
  27 #include <linux/init.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/seq_file.h>
  30 #include <linux/dmi.h>
  31 #include <linux/capability.h>
  32 #include <linux/mutex.h>
  33 #include <linux/hwmon.h>
  34 #include <linux/hwmon-sysfs.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/io.h>
  37 #include <linux/sched.h>
  38
  39 #include <linux/i8k.h>
  40
  41 #define I8K_SMM_FN_STATUS       0x0025
  42 #define I8K_SMM_POWER_STATUS    0x0069
  43 #define I8K_SMM_SET_FAN         0x01a3
  44 #define I8K_SMM_GET_FAN         0x00a3
  45 #define I8K_SMM_GET_SPEED       0x02a3
  46 #define I8K_SMM_GET_FAN_TYPE    0x03a3
  47 #define I8K_SMM_GET_NOM_SPEED   0x04a3
  48 #define I8K_SMM_GET_TEMP        0x10a3
  49 #define I8K_SMM_GET_TEMP_TYPE   0x11a3
  50 #define I8K_SMM_GET_DELL_SIG1   0xfea3
  51 #define I8K_SMM_GET_DELL_SIG2   0xffa3
  52
  53 #define I8K_FAN_MULT            30
  54 #define I8K_FAN_MAX_RPM         30000
  55 #define I8K_MAX_TEMP            127
  56
  57 #define I8K_FN_NONE             0x00
  58 #define I8K_FN_UP               0x01
  59 #define I8K_FN_DOWN             0x02
  60 #define I8K_FN_MUTE             0x04
  61 #define I8K_FN_MASK             0x07
  62 #define I8K_FN_SHIFT            8
  63
  64 #define I8K_POWER_AC            0x05
  65 #define I8K_POWER_BATTERY       0x01
  66
  67 static DEFINE_MUTEX(i8k_mutex);
  68 static char bios_version[4];
  69 static struct device *i8k_hwmon_dev;
  70 static u32 i8k_hwmon_flags;
  71 static uint i8k_fan_mult = I8K_FAN_MULT;
  72 static uint i8k_pwm_mult;
  73 static uint i8k_fan_max = I8K_FAN_HIGH;
  74
  75 #define I8K_HWMON_HAVE_TEMP1    (1 << 0)
  76 #define I8K_HWMON_HAVE_TEMP2    (1 << 1)
  77 #define I8K_HWMON_HAVE_TEMP3    (1 << 2)
  78 #define I8K_HWMON_HAVE_TEMP4    (1 << 3)
  79 #define I8K_HWMON_HAVE_FAN1     (1 << 4)
  80 #define I8K_HWMON_HAVE_FAN2     (1 << 5)
  81
  82 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
  83 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
  84 MODULE_LICENSE("GPL");
  85
  86 static bool force;
  87 module_param(force, bool, 0);
  88 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
  89
  90 static bool ignore_dmi;
  91 module_param(ignore_dmi, bool, 0);
  92 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
  93
  94 static bool restricted;
  95 module_param(restricted, bool, 0);
  96 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
  97
  98 static bool power_status;
  99 module_param(power_status, bool, 0600);
 100 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
 101
 102 static uint fan_mult;
 103 module_param(fan_mult, uint, 0);
 104 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
 105
 106 static uint fan_max;
 107 module_param(fan_max, uint, 0);
 108 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
 109
 110 static int i8k_open_fs(struct inode *inode, struct file *file);
 111 static long i8k_ioctl(struct file *, unsigned int, unsigned long);
 112
 113 static const struct file_operations i8k_fops = {
 114         .owner          = THIS_MODULE,
 115         .open           = i8k_open_fs,
 116         .read           = seq_read,
 117         .llseek         = seq_lseek,
 118         .release        = single_release,
 119         .unlocked_ioctl = i8k_ioctl,
 120 };
 121
 122 struct smm_regs {
 123         unsigned int eax;
 124         unsigned int ebx __packed;
 125         unsigned int ecx __packed;
 126         unsigned int edx __packed;
 127         unsigned int esi __packed;
 128         unsigned int edi __packed;
 129 };
 130
 131 static inline const char *i8k_get_dmi_data(int field)
 132 {
 133         const char *dmi_data = dmi_get_system_info(field);
 134
 135         return dmi_data && *dmi_data ? dmi_data : "?";
 136 }
 137
 138 /*
 139  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
 140  */
 141 static int i8k_smm(struct smm_regs *regs)
 142 {
 143         int rc;
 144         int eax = regs->eax;
 145         cpumask_var_t old_mask;
 146
 147         /* SMM requires CPU 0 */
 148         if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
 149                 return -ENOMEM;
 150         cpumask_copy(old_mask, &current->cpus_allowed);
 151         rc = set_cpus_allowed_ptr(current, cpumask_of(0));
 152         if (rc)
 153                 goto out;
 154         if (smp_processor_id() != 0) {
 155                 rc = -EBUSY;
 156                 goto out;
 157         }
 158
 159 #if defined(CONFIG_X86_64)
 160         asm volatile("pushq %%rax\n\t"
 161                 "movl 0(%%rax),%%edx\n\t"
 162                 "pushq %%rdx\n\t"
 163                 "movl 4(%%rax),%%ebx\n\t"
 164                 "movl 8(%%rax),%%ecx\n\t"
 165                 "movl 12(%%rax),%%edx\n\t"
 166                 "movl 16(%%rax),%%esi\n\t"
 167                 "movl 20(%%rax),%%edi\n\t"
 168                 "popq %%rax\n\t"
 169                 "out %%al,$0xb2\n\t"
 170                 "out %%al,$0x84\n\t"
 171                 "xchgq %%rax,(%%rsp)\n\t"
 172                 "movl %%ebx,4(%%rax)\n\t"
 173                 "movl %%ecx,8(%%rax)\n\t"
 174                 "movl %%edx,12(%%rax)\n\t"
 175                 "movl %%esi,16(%%rax)\n\t"
 176                 "movl %%edi,20(%%rax)\n\t"
 177                 "popq %%rdx\n\t"
 178                 "movl %%edx,0(%%rax)\n\t"
 179                 "pushfq\n\t"
 180                 "popq %%rax\n\t"
 181                 "andl $1,%%eax\n"
 182                 : "=a"(rc)
 183                 :    "a"(regs)
 184                 :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 185 #else
 186         asm volatile("pushl %%eax\n\t"
 187             "movl 0(%%eax),%%edx\n\t"
 188             "push %%edx\n\t"
 189             "movl 4(%%eax),%%ebx\n\t"
 190             "movl 8(%%eax),%%ecx\n\t"
 191             "movl 12(%%eax),%%edx\n\t"
 192             "movl 16(%%eax),%%esi\n\t"
 193             "movl 20(%%eax),%%edi\n\t"
 194             "popl %%eax\n\t"
 195             "out %%al,$0xb2\n\t"
 196             "out %%al,$0x84\n\t"
 197             "xchgl %%eax,(%%esp)\n\t"
 198             "movl %%ebx,4(%%eax)\n\t"
 199             "movl %%ecx,8(%%eax)\n\t"
 200             "movl %%edx,12(%%eax)\n\t"
 201             "movl %%esi,16(%%eax)\n\t"
 202             "movl %%edi,20(%%eax)\n\t"
 203             "popl %%edx\n\t"
 204             "movl %%edx,0(%%eax)\n\t"
 205             "lahf\n\t"
 206             "shrl $8,%%eax\n\t"
 207             "andl $1,%%eax\n"
 208             : "=a"(rc)
 209             :    "a"(regs)
 210             :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 211 #endif
 212         if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
 213                 rc = -EINVAL;
 214
 215 out:
 216         set_cpus_allowed_ptr(current, old_mask);
 217         free_cpumask_var(old_mask);
 218         return rc;
 219 }
 220
 221 /*
 222  * Read the Fn key status.
 223  */
 224 static int i8k_get_fn_status(void)
 225 {
 226         struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
 227         int rc;
 228
 229         rc = i8k_smm(&regs);
 230         if (rc < 0)
 231                 return rc;
 232
 233         switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 234         case I8K_FN_UP:
 235                 return I8K_VOL_UP;
 236         case I8K_FN_DOWN:
 237                 return I8K_VOL_DOWN;
 238         case I8K_FN_MUTE:
 239                 return I8K_VOL_MUTE;
 240         default:
 241                 return 0;
 242         }
 243 }
 244
 245 /*
 246  * Read the power status.
 247  */
 248 static int i8k_get_power_status(void)
 249 {
 250         struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
 251         int rc;
 252
 253         rc = i8k_smm(&regs);
 254         if (rc < 0)
 255                 return rc;
 256
 257         return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
 258 }
 259
 260 /*
 261  * Read the fan status.
 262  */
 263 static int i8k_get_fan_status(int fan)
 264 {
 265         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
 266
 267         regs.ebx = fan & 0xff;
 268         return i8k_smm(&regs) ? : regs.eax & 0xff;
 269 }
 270
 271 /*
 272  * Read the fan speed in RPM.
 273  */
 274 static int i8k_get_fan_speed(int fan)
 275 {
 276         struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
 277
 278         regs.ebx = fan & 0xff;
 279         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 280 }
 281
 282 /*
 283  * Read the fan type.
 284  */
 285 static int i8k_get_fan_type(int fan)
 286 {
 287         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
 288
 289         regs.ebx = fan & 0xff;
 290         return i8k_smm(&regs) ? : regs.eax & 0xff;
 291 }
 292
 293 /*
 294  * Read the fan nominal rpm for specific fan speed.
 295  */
 296 static int i8k_get_fan_nominal_speed(int fan, int speed)
 297 {
 298         struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
 299
 300         regs.ebx = (fan & 0xff) | (speed << 8);
 301         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 302 }
 303
 304 /*
 305  * Set the fan speed (off, low, high). Returns the new fan status.
 306  */
 307 static int i8k_set_fan(int fan, int speed)
 308 {
 309         struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
 310
 311         speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
 312         regs.ebx = (fan & 0xff) | (speed << 8);
 313
 314         return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
 315 }
 316
 317 static int i8k_get_temp_type(int sensor)
 318 {
 319         struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
 320
 321         regs.ebx = sensor & 0xff;
 322         return i8k_smm(&regs) ? : regs.eax & 0xff;
 323 }
 324
 325 /*
 326  * Read the cpu temperature.
 327  */
 328 static int _i8k_get_temp(int sensor)
 329 {
 330         struct smm_regs regs = {
 331                 .eax = I8K_SMM_GET_TEMP,
 332                 .ebx = sensor & 0xff,
 333         };
 334
 335         return i8k_smm(&regs) ? : regs.eax & 0xff;
 336 }
 337
 338 static int i8k_get_temp(int sensor)
 339 {
 340         int temp = _i8k_get_temp(sensor);
 341
 342         /*
 343          * Sometimes the temperature sensor returns 0x99, which is out of range.
 344          * In this case we retry (once) before returning an error.
 345          # 1003655137 00000058 00005a4b
 346          # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 347          # 1003655139 00000054 00005c52
 348          */
 349         if (temp == 0x99) {
 350                 msleep(100);
 351                 temp = _i8k_get_temp(sensor);
 352         }
 353         /*
 354          * Return -ENODATA for all invalid temperatures.
 355          *
 356          * Known instances are the 0x99 value as seen above as well as
 357          * 0xc1 (193), which may be returned when trying to read the GPU
 358          * temperature if the system supports a GPU and it is currently
 359          * turned off.
 360          */
 361         if (temp > I8K_MAX_TEMP)
 362                 return -ENODATA;
 363
 364         return temp;
 365 }
 366
 367 static int i8k_get_dell_signature(int req_fn)
 368 {
 369         struct smm_regs regs = { .eax = req_fn, };
 370         int rc;
 371
 372         rc = i8k_smm(&regs);
 373         if (rc < 0)
 374                 return rc;
 375
 376         return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 377 }
 378
 379 static int
 380 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
 381 {
 382         int val = 0;
 383         int speed;
 384         unsigned char buff[16];
 385         int __user *argp = (int __user *)arg;
 386
 387         if (!argp)
 388                 return -EINVAL;
 389
 390         switch (cmd) {
 391         case I8K_BIOS_VERSION:
 392                 val = (bios_version[0] << 16) |
 393                                 (bios_version[1] << 8) | bios_version[2];
 394                 break;
 395
 396         case I8K_MACHINE_ID:
 397                 memset(buff, 0, 16);
 398                 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
 399                         sizeof(buff));
 400                 break;
 401
 402         case I8K_FN_STATUS:
 403                 val = i8k_get_fn_status();
 404                 break;
 405
 406         case I8K_POWER_STATUS:
 407                 val = i8k_get_power_status();
 408                 break;
 409
 410         case I8K_GET_TEMP:
 411                 val = i8k_get_temp(0);
 412                 break;
 413
 414         case I8K_GET_SPEED:
 415                 if (copy_from_user(&val, argp, sizeof(int)))
 416                         return -EFAULT;
 417
 418                 val = i8k_get_fan_speed(val);
 419                 break;
 420
 421         case I8K_GET_FAN:
 422                 if (copy_from_user(&val, argp, sizeof(int)))
 423                         return -EFAULT;
 424
 425                 val = i8k_get_fan_status(val);
 426                 break;
 427
 428         case I8K_SET_FAN:
 429                 if (restricted && !capable(CAP_SYS_ADMIN))
 430                         return -EPERM;
 431
 432                 if (copy_from_user(&val, argp, sizeof(int)))
 433                         return -EFAULT;
 434
 435                 if (copy_from_user(&speed, argp + 1, sizeof(int)))
 436                         return -EFAULT;
 437
 438                 val = i8k_set_fan(val, speed);
 439                 break;
 440
 441         default:
 442                 return -EINVAL;
 443         }
 444
 445         if (val < 0)
 446                 return val;
 447
 448         switch (cmd) {
 449         case I8K_BIOS_VERSION:
 450                 if (copy_to_user(argp, &val, 4))
 451                         return -EFAULT;
 452
 453                 break;
 454         case I8K_MACHINE_ID:
 455                 if (copy_to_user(argp, buff, 16))
 456                         return -EFAULT;
 457
 458                 break;
 459         default:
 460                 if (copy_to_user(argp, &val, sizeof(int)))
 461                         return -EFAULT;
 462
 463                 break;
 464         }
 465
 466         return 0;
 467 }
 468
 469 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 470 {
 471         long ret;
 472
 473         mutex_lock(&i8k_mutex);
 474         ret = i8k_ioctl_unlocked(fp, cmd, arg);
 475         mutex_unlock(&i8k_mutex);
 476
 477         return ret;
 478 }
 479
 480 /*
 481  * Print the information for /proc/i8k.
 482  */
 483 static int i8k_proc_show(struct seq_file *seq, void *offset)
 484 {
 485         int fn_key, cpu_temp, ac_power;
 486         int left_fan, right_fan, left_speed, right_speed;
 487
 488         cpu_temp        = i8k_get_temp(0);                      /* 11100 µs */
 489         left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
 490         right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
 491         left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
 492         right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
 493         fn_key          = i8k_get_fn_status();                  /*   750 µs */
 494         if (power_status)
 495                 ac_power = i8k_get_power_status();              /* 14700 µs */
 496         else
 497                 ac_power = -1;
 498
 499         /*
 500          * Info:
 501          *
 502          * 1)  Format version (this will change if format changes)
 503          * 2)  BIOS version
 504          * 3)  BIOS machine ID
 505          * 4)  Cpu temperature
 506          * 5)  Left fan status
 507          * 6)  Right fan status
 508          * 7)  Left fan speed
 509          * 8)  Right fan speed
 510          * 9)  AC power
 511          * 10) Fn Key status
 512          */
 513         return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
 514                           I8K_PROC_FMT,
 515                           bios_version,
 516                           i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
 517                           cpu_temp,
 518                           left_fan, right_fan, left_speed, right_speed,
 519                           ac_power, fn_key);
 520 }
 521
 522 static int i8k_open_fs(struct inode *inode, struct file *file)
 523 {
 524         return single_open(file, i8k_proc_show, NULL);
 525 }
 526
 527
 528 /*
 529  * Hwmon interface
 530  */
 531
 532 static ssize_t i8k_hwmon_show_temp_label(struct device *dev,
 533                                          struct device_attribute *devattr,
 534                                          char *buf)
 535 {
 536         static const char * const labels[] = {
 537                 "CPU",
 538                 "GPU",
 539                 "SODIMM",
 540                 "Other",
 541                 "Ambient",
 542                 "Other",
 543         };
 544         int index = to_sensor_dev_attr(devattr)->index;
 545         int type;
 546
 547         type = i8k_get_temp_type(index);
 548         if (type < 0)
 549                 return type;
 550         if (type >= ARRAY_SIZE(labels))
 551                 type = ARRAY_SIZE(labels) - 1;
 552         return sprintf(buf, "%s\n", labels[type]);
 553 }
 554
 555 static ssize_t i8k_hwmon_show_temp(struct device *dev,
 556                                    struct device_attribute *devattr,
 557                                    char *buf)
 558 {
 559         int index = to_sensor_dev_attr(devattr)->index;
 560         int temp;
 561
 562         temp = i8k_get_temp(index);
 563         if (temp < 0)
 564                 return temp;
 565         return sprintf(buf, "%d\n", temp * 1000);
 566 }
 567
 568 static ssize_t i8k_hwmon_show_fan_label(struct device *dev,
 569                                         struct device_attribute *devattr,
 570                                         char *buf)
 571 {
 572         static const char * const labels[] = {
 573                 "Processor Fan",
 574                 "Motherboard Fan",
 575                 "Video Fan",
 576                 "Power Supply Fan",
 577                 "Chipset Fan",
 578                 "Other Fan",
 579         };
 580         int index = to_sensor_dev_attr(devattr)->index;
 581         bool dock = false;
 582         int type;
 583
 584         type = i8k_get_fan_type(index);
 585         if (type < 0)
 586                 return type;
 587
 588         if (type & 0x10) {
 589                 dock = true;
 590                 type &= 0x0F;
 591         }
 592
 593         if (type >= ARRAY_SIZE(labels))
 594                 type = (ARRAY_SIZE(labels) - 1);
 595
 596         return sprintf(buf, "%s%s\n", (dock ? "Docking " : ""), labels[type]);
 597 }
 598
 599 static ssize_t i8k_hwmon_show_fan(struct device *dev,
 600                                   struct device_attribute *devattr,
 601                                   char *buf)
 602 {
 603         int index = to_sensor_dev_attr(devattr)->index;
 604         int fan_speed;
 605
 606         fan_speed = i8k_get_fan_speed(index);
 607         if (fan_speed < 0)
 608                 return fan_speed;
 609         return sprintf(buf, "%d\n", fan_speed);
 610 }
 611
 612 static ssize_t i8k_hwmon_show_pwm(struct device *dev,
 613                                   struct device_attribute *devattr,
 614                                   char *buf)
 615 {
 616         int index = to_sensor_dev_attr(devattr)->index;
 617         int status;
 618
 619         status = i8k_get_fan_status(index);
 620         if (status < 0)
 621                 return -EIO;
 622         return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
 623 }
 624
 625 static ssize_t i8k_hwmon_set_pwm(struct device *dev,
 626                                  struct device_attribute *attr,
 627                                  const char *buf, size_t count)
 628 {
 629         int index = to_sensor_dev_attr(attr)->index;
 630         unsigned long val;
 631         int err;
 632
 633         err = kstrtoul(buf, 10, &val);
 634         if (err)
 635                 return err;
 636         val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);
 637
 638         mutex_lock(&i8k_mutex);
 639         err = i8k_set_fan(index, val);
 640         mutex_unlock(&i8k_mutex);
 641
 642         return err < 0 ? -EIO : count;
 643 }
 644
 645 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
 646 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 647                           0);
 648 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
 649 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 650                           1);
 651 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
 652 static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 653                           2);
 654 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
 655 static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 656                           3);
 657 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL, 0);
 658 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
 659                           0);
 660 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 661                           i8k_hwmon_set_pwm, 0);
 662 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
 663                           1);
 664 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
 665                           1);
 666 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 667                           i8k_hwmon_set_pwm, 1);
 668
 669 static struct attribute *i8k_attrs[] = {
 670         &sensor_dev_attr_temp1_input.dev_attr.attr,     /* 0 */
 671         &sensor_dev_attr_temp1_label.dev_attr.attr,     /* 1 */
 672         &sensor_dev_attr_temp2_input.dev_attr.attr,     /* 2 */
 673         &sensor_dev_attr_temp2_label.dev_attr.attr,     /* 3 */
 674         &sensor_dev_attr_temp3_input.dev_attr.attr,     /* 4 */
 675         &sensor_dev_attr_temp3_label.dev_attr.attr,     /* 5 */
 676         &sensor_dev_attr_temp4_input.dev_attr.attr,     /* 6 */
 677         &sensor_dev_attr_temp4_label.dev_attr.attr,     /* 7 */
 678         &sensor_dev_attr_fan1_input.dev_attr.attr,      /* 8 */
 679         &sensor_dev_attr_fan1_label.dev_attr.attr,      /* 9 */
 680         &sensor_dev_attr_pwm1.dev_attr.attr,            /* 10 */
 681         &sensor_dev_attr_fan2_input.dev_attr.attr,      /* 11 */
 682         &sensor_dev_attr_fan2_label.dev_attr.attr,      /* 12 */
 683         &sensor_dev_attr_pwm2.dev_attr.attr,            /* 13 */
 684         NULL
 685 };
 686
 687 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
 688                               int index)
 689 {
 690         if (index >= 0 && index <= 1 &&
 691             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
 692                 return 0;
 693         if (index >= 2 && index <= 3 &&
 694             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
 695                 return 0;
 696         if (index >= 4 && index <= 5 &&
 697             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
 698                 return 0;
 699         if (index >= 6 && index <= 7 &&
 700             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
 701                 return 0;
 702         if (index >= 8 && index <= 10 &&
 703             !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
 704                 return 0;
 705         if (index >= 11 && index <= 13 &&
 706             !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
 707                 return 0;
 708
 709         return attr->mode;
 710 }
 711
 712 static const struct attribute_group i8k_group = {
 713         .attrs = i8k_attrs,
 714         .is_visible = i8k_is_visible,
 715 };
 716 __ATTRIBUTE_GROUPS(i8k);
 717
 718 static int __init i8k_init_hwmon(void)
 719 {
 720         int err;
 721
 722         i8k_hwmon_flags = 0;
 723
 724         /* CPU temperature attributes, if temperature type is OK */
 725         err = i8k_get_temp_type(0);
 726         if (err >= 0)
 727                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
 728         /* check for additional temperature sensors */
 729         err = i8k_get_temp_type(1);
 730         if (err >= 0)
 731                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
 732         err = i8k_get_temp_type(2);
 733         if (err >= 0)
 734                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
 735         err = i8k_get_temp_type(3);
 736         if (err >= 0)
 737                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
 738
 739         /* First fan attributes, if fan type is OK */
 740         err = i8k_get_fan_type(0);
 741         if (err >= 0)
 742                 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
 743
 744         /* Second fan attributes, if fan type is OK */
 745         err = i8k_get_fan_type(1);
 746         if (err >= 0)
 747                 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
 748
 749         i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
 750                                                           i8k_groups);
 751         if (IS_ERR(i8k_hwmon_dev)) {
 752                 err = PTR_ERR(i8k_hwmon_dev);
 753                 i8k_hwmon_dev = NULL;
 754                 pr_err("hwmon registration failed (%d)\n", err);
 755                 return err;
 756         }
 757         return 0;
 758 }
 759
 760 struct i8k_config_data {
 761         uint fan_mult;
 762         uint fan_max;
 763 };
 764
 765 enum i8k_configs {
 766         DELL_LATITUDE_D520,
 767         DELL_PRECISION_490,
 768         DELL_STUDIO,
 769         DELL_XPS,
 770 };
 771
 772 static const struct i8k_config_data i8k_config_data[] = {
 773         [DELL_LATITUDE_D520] = {
 774                 .fan_mult = 1,
 775                 .fan_max = I8K_FAN_TURBO,
 776         },
 777         [DELL_PRECISION_490] = {
 778                 .fan_mult = 1,
 779                 .fan_max = I8K_FAN_TURBO,
 780         },
 781         [DELL_STUDIO] = {
 782                 .fan_mult = 1,
 783                 .fan_max = I8K_FAN_HIGH,
 784         },
 785         [DELL_XPS] = {
 786                 .fan_mult = 1,
 787                 .fan_max = I8K_FAN_HIGH,
 788         },
 789 };
 790
 791 static struct dmi_system_id i8k_dmi_table[] __initdata = {
 792         {
 793                 .ident = "Dell Inspiron",
 794                 .matches = {
 795                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 796                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 797                 },
 798         },
 799         {
 800                 .ident = "Dell Latitude",
 801                 .matches = {
 802                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 803                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 804                 },
 805         },
 806         {
 807                 .ident = "Dell Inspiron 2",
 808                 .matches = {
 809                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 810                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 811                 },
 812         },
 813         {
 814                 .ident = "Dell Latitude D520",
 815                 .matches = {
 816                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 817                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
 818                 },
 819                 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
 820         },
 821         {
 822                 .ident = "Dell Latitude 2",
 823                 .matches = {
 824                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 825                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 826                 },
 827         },
 828         {       /* UK Inspiron 6400  */
 829                 .ident = "Dell Inspiron 3",
 830                 .matches = {
 831                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 832                         DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
 833                 },
 834         },
 835         {
 836                 .ident = "Dell Inspiron 3",
 837                 .matches = {
 838                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 839                         DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
 840                 },
 841         },
 842         {
 843                 .ident = "Dell Precision 490",
 844                 .matches = {
 845                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 846                         DMI_MATCH(DMI_PRODUCT_NAME,
 847                                   "Precision WorkStation 490"),
 848                 },
 849                 .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
 850         },
 851         {
 852                 .ident = "Dell Precision",
 853                 .matches = {
 854                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 855                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
 856                 },
 857         },
 858         {
 859                 .ident = "Dell Vostro",
 860                 .matches = {
 861                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 862                         DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
 863                 },
 864         },
 865         {
 866                 .ident = "Dell XPS421",
 867                 .matches = {
 868                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 869                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
 870                 },
 871         },
 872         {
 873                 .ident = "Dell Studio",
 874                 .matches = {
 875                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 876                         DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
 877                 },
 878                 .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
 879         },
 880         {
 881                 .ident = "Dell XPS 13",
 882                 .matches = {
 883                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 884                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS13"),
 885                 },
 886                 .driver_data = (void *)&i8k_config_data[DELL_XPS],
 887         },
 888         {
 889                 .ident = "Dell XPS M140",
 890                 .matches = {
 891                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 892                         DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
 893                 },
 894                 .driver_data = (void *)&i8k_config_data[DELL_XPS],
 895         },
 896         { }
 897 };
 898
 899 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
 900
 901 /*
 902  * Probe for the presence of a supported laptop.
 903  */
 904 static int __init i8k_probe(void)
 905 {
 906         const struct dmi_system_id *id;
 907         int fan, ret;
 908
 909         /*
 910          * Get DMI information
 911          */
 912         if (!dmi_check_system(i8k_dmi_table)) {
 913                 if (!ignore_dmi && !force)
 914                         return -ENODEV;
 915
 916                 pr_info("not running on a supported Dell system.\n");
 917                 pr_info("vendor=%s, model=%s, version=%s\n",
 918                         i8k_get_dmi_data(DMI_SYS_VENDOR),
 919                         i8k_get_dmi_data(DMI_PRODUCT_NAME),
 920                         i8k_get_dmi_data(DMI_BIOS_VERSION));
 921         }
 922
 923         strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
 924                 sizeof(bios_version));
 925
 926         /*
 927          * Get SMM Dell signature
 928          */
 929         if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
 930             i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
 931                 pr_err("unable to get SMM Dell signature\n");
 932                 if (!force)
 933                         return -ENODEV;
 934         }
 935
 936         /*
 937          * Set fan multiplier and maximal fan speed from dmi config
 938          * Values specified in module parameters override values from dmi
 939          */
 940         id = dmi_first_match(i8k_dmi_table);
 941         if (id && id->driver_data) {
 942                 const struct i8k_config_data *conf = id->driver_data;
 943                 if (!fan_mult && conf->fan_mult)
 944                         fan_mult = conf->fan_mult;
 945                 if (!fan_max && conf->fan_max)
 946                         fan_max = conf->fan_max;
 947         }
 948
 949         i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
 950         i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);
 951
 952         if (!fan_mult) {
 953                 /*
 954                  * Autodetect fan multiplier based on nominal rpm
 955                  * If fan reports rpm value too high then set multiplier to 1
 956                  */
 957                 for (fan = 0; fan < 2; ++fan) {
 958                         ret = i8k_get_fan_nominal_speed(fan, i8k_fan_max);
 959                         if (ret < 0)
 960                                 continue;
 961                         if (ret > I8K_FAN_MAX_RPM)
 962                                 i8k_fan_mult = 1;
 963                         break;
 964                 }
 965         } else {
 966                 /* Fan multiplier was specified in module param or in dmi */
 967                 i8k_fan_mult = fan_mult;
 968         }
 969
 970         return 0;
 971 }
 972
 973 static int __init i8k_init(void)
 974 {
 975         struct proc_dir_entry *proc_i8k;
 976         int err;
 977
 978         /* Are we running on an supported laptop? */
 979         if (i8k_probe())
 980                 return -ENODEV;
 981
 982         /* Register the proc entry */
 983         proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
 984         if (!proc_i8k)
 985                 return -ENOENT;
 986
 987         err = i8k_init_hwmon();
 988         if (err)
 989                 goto exit_remove_proc;
 990
 991         return 0;
 992
 993  exit_remove_proc:
 994         remove_proc_entry("i8k", NULL);
 995         return err;
 996 }
 997
 998 static void __exit i8k_exit(void)
 999 {
1000         hwmon_device_unregister(i8k_hwmon_dev);
1001         remove_proc_entry("i8k", NULL);
1002 }
1003
1004 module_init(i8k_init);
1005 module_exit(i8k_exit);