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