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