drivers/hwmon/dell-smm-hwmon.c

   1 /*
   2  * dell-smm-hwmon.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, 2015  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 #include <linux/ctype.h>
  39
  40 #include <linux/i8k.h>
  41
  42 #define I8K_SMM_FN_STATUS       0x0025
  43 #define I8K_SMM_POWER_STATUS    0x0069
  44 #define I8K_SMM_SET_FAN         0x01a3
  45 #define I8K_SMM_GET_FAN         0x00a3
  46 #define I8K_SMM_GET_SPEED       0x02a3
  47 #define I8K_SMM_GET_FAN_TYPE    0x03a3
  48 #define I8K_SMM_GET_NOM_SPEED   0x04a3
  49 #define I8K_SMM_GET_TEMP        0x10a3
  50 #define I8K_SMM_GET_TEMP_TYPE   0x11a3
  51 #define I8K_SMM_GET_DELL_SIG1   0xfea3
  52 #define I8K_SMM_GET_DELL_SIG2   0xffa3
  53
  54 #define I8K_FAN_MULT            30
  55 #define I8K_FAN_MAX_RPM         30000
  56 #define I8K_MAX_TEMP            127
  57
  58 #define I8K_FN_NONE             0x00
  59 #define I8K_FN_UP               0x01
  60 #define I8K_FN_DOWN             0x02
  61 #define I8K_FN_MUTE             0x04
  62 #define I8K_FN_MASK             0x07
  63 #define I8K_FN_SHIFT            8
  64
  65 #define I8K_POWER_AC            0x05
  66 #define I8K_POWER_BATTERY       0x01
  67
  68 static DEFINE_MUTEX(i8k_mutex);
  69 static char bios_version[4];
  70 static char bios_machineid[16];
  71 static struct device *i8k_hwmon_dev;
  72 static u32 i8k_hwmon_flags;
  73 static uint i8k_fan_mult = I8K_FAN_MULT;
  74 static uint i8k_pwm_mult;
  75 static uint i8k_fan_max = I8K_FAN_HIGH;
  76 static bool disallow_fan_type_call;
  77
  78 #define I8K_HWMON_HAVE_TEMP1    (1 << 0)
  79 #define I8K_HWMON_HAVE_TEMP2    (1 << 1)
  80 #define I8K_HWMON_HAVE_TEMP3    (1 << 2)
  81 #define I8K_HWMON_HAVE_TEMP4    (1 << 3)
  82 #define I8K_HWMON_HAVE_FAN1     (1 << 4)
  83 #define I8K_HWMON_HAVE_FAN2     (1 << 5)
  84
  85 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
  86 MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
  87 MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
  88 MODULE_LICENSE("GPL");
  89 MODULE_ALIAS("i8k");
  90
  91 static bool force;
  92 module_param(force, bool, 0);
  93 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
  94
  95 static bool ignore_dmi;
  96 module_param(ignore_dmi, bool, 0);
  97 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
  98
  99 #if IS_ENABLED(CONFIG_I8K)
 100 static bool restricted = true;
 101 module_param(restricted, bool, 0);
 102 MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
 103
 104 static bool power_status;
 105 module_param(power_status, bool, 0600);
 106 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
 107 #endif
 108
 109 static uint fan_mult;
 110 module_param(fan_mult, uint, 0);
 111 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
 112
 113 static uint fan_max;
 114 module_param(fan_max, uint, 0);
 115 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
 116
 117 struct smm_regs {
 118         unsigned int eax;
 119         unsigned int ebx __packed;
 120         unsigned int ecx __packed;
 121         unsigned int edx __packed;
 122         unsigned int esi __packed;
 123         unsigned int edi __packed;
 124 };
 125
 126 static inline const char *i8k_get_dmi_data(int field)
 127 {
 128         const char *dmi_data = dmi_get_system_info(field);
 129
 130         return dmi_data && *dmi_data ? dmi_data : "?";
 131 }
 132
 133 /*
 134  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
 135  */
 136 static int i8k_smm(struct smm_regs *regs)
 137 {
 138         int rc;
 139         int eax = regs->eax;
 140         cpumask_var_t old_mask;
 141
 142         /* SMM requires CPU 0 */
 143         if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
 144                 return -ENOMEM;
 145         cpumask_copy(old_mask, &current->cpus_allowed);
 146         rc = set_cpus_allowed_ptr(current, cpumask_of(0));
 147         if (rc)
 148                 goto out;
 149         if (smp_processor_id() != 0) {
 150                 rc = -EBUSY;
 151                 goto out;
 152         }
 153
 154 #if defined(CONFIG_X86_64)
 155         asm volatile("pushq %%rax\n\t"
 156                 "movl 0(%%rax),%%edx\n\t"
 157                 "pushq %%rdx\n\t"
 158                 "movl 4(%%rax),%%ebx\n\t"
 159                 "movl 8(%%rax),%%ecx\n\t"
 160                 "movl 12(%%rax),%%edx\n\t"
 161                 "movl 16(%%rax),%%esi\n\t"
 162                 "movl 20(%%rax),%%edi\n\t"
 163                 "popq %%rax\n\t"
 164                 "out %%al,$0xb2\n\t"
 165                 "out %%al,$0x84\n\t"
 166                 "xchgq %%rax,(%%rsp)\n\t"
 167                 "movl %%ebx,4(%%rax)\n\t"
 168                 "movl %%ecx,8(%%rax)\n\t"
 169                 "movl %%edx,12(%%rax)\n\t"
 170                 "movl %%esi,16(%%rax)\n\t"
 171                 "movl %%edi,20(%%rax)\n\t"
 172                 "popq %%rdx\n\t"
 173                 "movl %%edx,0(%%rax)\n\t"
 174                 "pushfq\n\t"
 175                 "popq %%rax\n\t"
 176                 "andl $1,%%eax\n"
 177                 : "=a"(rc)
 178                 :    "a"(regs)
 179                 :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 180 #else
 181         asm volatile("pushl %%eax\n\t"
 182             "movl 0(%%eax),%%edx\n\t"
 183             "push %%edx\n\t"
 184             "movl 4(%%eax),%%ebx\n\t"
 185             "movl 8(%%eax),%%ecx\n\t"
 186             "movl 12(%%eax),%%edx\n\t"
 187             "movl 16(%%eax),%%esi\n\t"
 188             "movl 20(%%eax),%%edi\n\t"
 189             "popl %%eax\n\t"
 190             "out %%al,$0xb2\n\t"
 191             "out %%al,$0x84\n\t"
 192             "xchgl %%eax,(%%esp)\n\t"
 193             "movl %%ebx,4(%%eax)\n\t"
 194             "movl %%ecx,8(%%eax)\n\t"
 195             "movl %%edx,12(%%eax)\n\t"
 196             "movl %%esi,16(%%eax)\n\t"
 197             "movl %%edi,20(%%eax)\n\t"
 198             "popl %%edx\n\t"
 199             "movl %%edx,0(%%eax)\n\t"
 200             "lahf\n\t"
 201             "shrl $8,%%eax\n\t"
 202             "andl $1,%%eax\n"
 203             : "=a"(rc)
 204             :    "a"(regs)
 205             :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 206 #endif
 207         if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
 208                 rc = -EINVAL;
 209
 210 out:
 211         set_cpus_allowed_ptr(current, old_mask);
 212         free_cpumask_var(old_mask);
 213         return rc;
 214 }
 215
 216 /*
 217  * Read the fan status.
 218  */
 219 static int i8k_get_fan_status(int fan)
 220 {
 221         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
 222
 223         regs.ebx = fan & 0xff;
 224         return i8k_smm(&regs) ? : regs.eax & 0xff;
 225 }
 226
 227 /*
 228  * Read the fan speed in RPM.
 229  */
 230 static int i8k_get_fan_speed(int fan)
 231 {
 232         struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
 233
 234         regs.ebx = fan & 0xff;
 235         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 236 }
 237
 238 /*
 239  * Read the fan type.
 240  */
 241 static int _i8k_get_fan_type(int fan)
 242 {
 243         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
 244
 245         if (disallow_fan_type_call)
 246                 return -EINVAL;
 247
 248         regs.ebx = fan & 0xff;
 249         return i8k_smm(&regs) ? : regs.eax & 0xff;
 250 }
 251
 252 static int i8k_get_fan_type(int fan)
 253 {
 254         /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
 255         static int types[2] = { INT_MIN, INT_MIN };
 256
 257         if (types[fan] == INT_MIN)
 258                 types[fan] = _i8k_get_fan_type(fan);
 259
 260         return types[fan];
 261 }
 262
 263 /*
 264  * Read the fan nominal rpm for specific fan speed.
 265  */
 266 static int i8k_get_fan_nominal_speed(int fan, int speed)
 267 {
 268         struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
 269
 270         regs.ebx = (fan & 0xff) | (speed << 8);
 271         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 272 }
 273
 274 /*
 275  * Set the fan speed (off, low, high). Returns the new fan status.
 276  */
 277 static int i8k_set_fan(int fan, int speed)
 278 {
 279         struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
 280
 281         speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
 282         regs.ebx = (fan & 0xff) | (speed << 8);
 283
 284         return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
 285 }
 286
 287 static int i8k_get_temp_type(int sensor)
 288 {
 289         struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
 290
 291         regs.ebx = sensor & 0xff;
 292         return i8k_smm(&regs) ? : regs.eax & 0xff;
 293 }
 294
 295 /*
 296  * Read the cpu temperature.
 297  */
 298 static int _i8k_get_temp(int sensor)
 299 {
 300         struct smm_regs regs = {
 301                 .eax = I8K_SMM_GET_TEMP,
 302                 .ebx = sensor & 0xff,
 303         };
 304
 305         return i8k_smm(&regs) ? : regs.eax & 0xff;
 306 }
 307
 308 static int i8k_get_temp(int sensor)
 309 {
 310         int temp = _i8k_get_temp(sensor);
 311
 312         /*
 313          * Sometimes the temperature sensor returns 0x99, which is out of range.
 314          * In this case we retry (once) before returning an error.
 315          # 1003655137 00000058 00005a4b
 316          # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 317          # 1003655139 00000054 00005c52
 318          */
 319         if (temp == 0x99) {
 320                 msleep(100);
 321                 temp = _i8k_get_temp(sensor);
 322         }
 323         /*
 324          * Return -ENODATA for all invalid temperatures.
 325          *
 326          * Known instances are the 0x99 value as seen above as well as
 327          * 0xc1 (193), which may be returned when trying to read the GPU
 328          * temperature if the system supports a GPU and it is currently
 329          * turned off.
 330          */
 331         if (temp > I8K_MAX_TEMP)
 332                 return -ENODATA;
 333
 334         return temp;
 335 }
 336
 337 static int i8k_get_dell_signature(int req_fn)
 338 {
 339         struct smm_regs regs = { .eax = req_fn, };
 340         int rc;
 341
 342         rc = i8k_smm(&regs);
 343         if (rc < 0)
 344                 return rc;
 345
 346         return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 347 }
 348
 349 #if IS_ENABLED(CONFIG_I8K)
 350
 351 /*
 352  * Read the Fn key status.
 353  */
 354 static int i8k_get_fn_status(void)
 355 {
 356         struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
 357         int rc;
 358
 359         rc = i8k_smm(&regs);
 360         if (rc < 0)
 361                 return rc;
 362
 363         switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 364         case I8K_FN_UP:
 365                 return I8K_VOL_UP;
 366         case I8K_FN_DOWN:
 367                 return I8K_VOL_DOWN;
 368         case I8K_FN_MUTE:
 369                 return I8K_VOL_MUTE;
 370         default:
 371                 return 0;
 372         }
 373 }
 374
 375 /*
 376  * Read the power status.
 377  */
 378 static int i8k_get_power_status(void)
 379 {
 380         struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
 381         int rc;
 382
 383         rc = i8k_smm(&regs);
 384         if (rc < 0)
 385                 return rc;
 386
 387         return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
 388 }
 389
 390 /*
 391  * Procfs interface
 392  */
 393
 394 static int
 395 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
 396 {
 397         int val = 0;
 398         int speed;
 399         unsigned char buff[16];
 400         int __user *argp = (int __user *)arg;
 401
 402         if (!argp)
 403                 return -EINVAL;
 404
 405         switch (cmd) {
 406         case I8K_BIOS_VERSION:
 407                 if (!isdigit(bios_version[0]) || !isdigit(bios_version[1]) ||
 408                     !isdigit(bios_version[2]))
 409                         return -EINVAL;
 410
 411                 val = (bios_version[0] << 16) |
 412                                 (bios_version[1] << 8) | bios_version[2];
 413                 break;
 414
 415         case I8K_MACHINE_ID:
 416                 if (restricted && !capable(CAP_SYS_ADMIN))
 417                         return -EPERM;
 418
 419                 memset(buff, 0, sizeof(buff));
 420                 strlcpy(buff, bios_machineid, sizeof(buff));
 421                 break;
 422
 423         case I8K_FN_STATUS:
 424                 val = i8k_get_fn_status();
 425                 break;
 426
 427         case I8K_POWER_STATUS:
 428                 val = i8k_get_power_status();
 429                 break;
 430
 431         case I8K_GET_TEMP:
 432                 val = i8k_get_temp(0);
 433                 break;
 434
 435         case I8K_GET_SPEED:
 436                 if (copy_from_user(&val, argp, sizeof(int)))
 437                         return -EFAULT;
 438
 439                 val = i8k_get_fan_speed(val);
 440                 break;
 441
 442         case I8K_GET_FAN:
 443                 if (copy_from_user(&val, argp, sizeof(int)))
 444                         return -EFAULT;
 445
 446                 val = i8k_get_fan_status(val);
 447                 break;
 448
 449         case I8K_SET_FAN:
 450                 if (restricted && !capable(CAP_SYS_ADMIN))
 451                         return -EPERM;
 452
 453                 if (copy_from_user(&val, argp, sizeof(int)))
 454                         return -EFAULT;
 455
 456                 if (copy_from_user(&speed, argp + 1, sizeof(int)))
 457                         return -EFAULT;
 458
 459                 val = i8k_set_fan(val, speed);
 460                 break;
 461
 462         default:
 463                 return -EINVAL;
 464         }
 465
 466         if (val < 0)
 467                 return val;
 468
 469         switch (cmd) {
 470         case I8K_BIOS_VERSION:
 471                 if (copy_to_user(argp, &val, 4))
 472                         return -EFAULT;
 473
 474                 break;
 475         case I8K_MACHINE_ID:
 476                 if (copy_to_user(argp, buff, 16))
 477                         return -EFAULT;
 478
 479                 break;
 480         default:
 481                 if (copy_to_user(argp, &val, sizeof(int)))
 482                         return -EFAULT;
 483
 484                 break;
 485         }
 486
 487         return 0;
 488 }
 489
 490 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 491 {
 492         long ret;
 493
 494         mutex_lock(&i8k_mutex);
 495         ret = i8k_ioctl_unlocked(fp, cmd, arg);
 496         mutex_unlock(&i8k_mutex);
 497
 498         return ret;
 499 }
 500
 501 /*
 502  * Print the information for /proc/i8k.
 503  */
 504 static int i8k_proc_show(struct seq_file *seq, void *offset)
 505 {
 506         int fn_key, cpu_temp, ac_power;
 507         int left_fan, right_fan, left_speed, right_speed;
 508
 509         cpu_temp        = i8k_get_temp(0);                      /* 11100 µs */
 510         left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
 511         right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
 512         left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
 513         right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
 514         fn_key          = i8k_get_fn_status();                  /*   750 µs */
 515         if (power_status)
 516                 ac_power = i8k_get_power_status();              /* 14700 µs */
 517         else
 518                 ac_power = -1;
 519
 520         /*
 521          * Info:
 522          *
 523          * 1)  Format version (this will change if format changes)
 524          * 2)  BIOS version
 525          * 3)  BIOS machine ID
 526          * 4)  Cpu temperature
 527          * 5)  Left fan status
 528          * 6)  Right fan status
 529          * 7)  Left fan speed
 530          * 8)  Right fan speed
 531          * 9)  AC power
 532          * 10) Fn Key status
 533          */
 534         seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
 535                    I8K_PROC_FMT,
 536                    bios_version,
 537                    (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : bios_machineid,
 538                    cpu_temp,
 539                    left_fan, right_fan, left_speed, right_speed,
 540                    ac_power, fn_key);
 541
 542         return 0;
 543 }
 544
 545 static int i8k_open_fs(struct inode *inode, struct file *file)
 546 {
 547         return single_open(file, i8k_proc_show, NULL);
 548 }
 549
 550 static const struct file_operations i8k_fops = {
 551         .owner          = THIS_MODULE,
 552         .open           = i8k_open_fs,
 553         .read           = seq_read,
 554         .llseek         = seq_lseek,
 555         .release        = single_release,
 556         .unlocked_ioctl = i8k_ioctl,
 557 };
 558
 559 static void __init i8k_init_procfs(void)
 560 {
 561         /* Register the proc entry */
 562         proc_create("i8k", 0, NULL, &i8k_fops);
 563 }
 564
 565 static void __exit i8k_exit_procfs(void)
 566 {
 567         remove_proc_entry("i8k", NULL);
 568 }
 569
 570 #else
 571
 572 static inline void __init i8k_init_procfs(void)
 573 {
 574 }
 575
 576 static inline void __exit i8k_exit_procfs(void)
 577 {
 578 }
 579
 580 #endif
 581
 582 /*
 583  * Hwmon interface
 584  */
 585
 586 static ssize_t i8k_hwmon_show_temp_label(struct device *dev,
 587                                          struct device_attribute *devattr,
 588                                          char *buf)
 589 {
 590         static const char * const labels[] = {
 591                 "CPU",
 592                 "GPU",
 593                 "SODIMM",
 594                 "Other",
 595                 "Ambient",
 596                 "Other",
 597         };
 598         int index = to_sensor_dev_attr(devattr)->index;
 599         int type;
 600
 601         type = i8k_get_temp_type(index);
 602         if (type < 0)
 603                 return type;
 604         if (type >= ARRAY_SIZE(labels))
 605                 type = ARRAY_SIZE(labels) - 1;
 606         return sprintf(buf, "%s\n", labels[type]);
 607 }
 608
 609 static ssize_t i8k_hwmon_show_temp(struct device *dev,
 610                                    struct device_attribute *devattr,
 611                                    char *buf)
 612 {
 613         int index = to_sensor_dev_attr(devattr)->index;
 614         int temp;
 615
 616         temp = i8k_get_temp(index);
 617         if (temp < 0)
 618                 return temp;
 619         return sprintf(buf, "%d\n", temp * 1000);
 620 }
 621
 622 static ssize_t i8k_hwmon_show_fan_label(struct device *dev,
 623                                         struct device_attribute *devattr,
 624                                         char *buf)
 625 {
 626         static const char * const labels[] = {
 627                 "Processor Fan",
 628                 "Motherboard Fan",
 629                 "Video Fan",
 630                 "Power Supply Fan",
 631                 "Chipset Fan",
 632                 "Other Fan",
 633         };
 634         int index = to_sensor_dev_attr(devattr)->index;
 635         bool dock = false;
 636         int type;
 637
 638         type = i8k_get_fan_type(index);
 639         if (type < 0)
 640                 return type;
 641
 642         if (type & 0x10) {
 643                 dock = true;
 644                 type &= 0x0F;
 645         }
 646
 647         if (type >= ARRAY_SIZE(labels))
 648                 type = (ARRAY_SIZE(labels) - 1);
 649
 650         return sprintf(buf, "%s%s\n", (dock ? "Docking " : ""), labels[type]);
 651 }
 652
 653 static ssize_t i8k_hwmon_show_fan(struct device *dev,
 654                                   struct device_attribute *devattr,
 655                                   char *buf)
 656 {
 657         int index = to_sensor_dev_attr(devattr)->index;
 658         int fan_speed;
 659
 660         fan_speed = i8k_get_fan_speed(index);
 661         if (fan_speed < 0)
 662                 return fan_speed;
 663         return sprintf(buf, "%d\n", fan_speed);
 664 }
 665
 666 static ssize_t i8k_hwmon_show_pwm(struct device *dev,
 667                                   struct device_attribute *devattr,
 668                                   char *buf)
 669 {
 670         int index = to_sensor_dev_attr(devattr)->index;
 671         int status;
 672
 673         status = i8k_get_fan_status(index);
 674         if (status < 0)
 675                 return -EIO;
 676         return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
 677 }
 678
 679 static ssize_t i8k_hwmon_set_pwm(struct device *dev,
 680                                  struct device_attribute *attr,
 681                                  const char *buf, size_t count)
 682 {
 683         int index = to_sensor_dev_attr(attr)->index;
 684         unsigned long val;
 685         int err;
 686
 687         err = kstrtoul(buf, 10, &val);
 688         if (err)
 689                 return err;
 690         val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);
 691
 692         mutex_lock(&i8k_mutex);
 693         err = i8k_set_fan(index, val);
 694         mutex_unlock(&i8k_mutex);
 695
 696         return err < 0 ? -EIO : count;
 697 }
 698
 699 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
 700 static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 701                           0);
 702 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
 703 static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 704                           1);
 705 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
 706 static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 707                           2);
 708 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
 709 static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 710                           3);
 711 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL, 0);
 712 static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
 713                           0);
 714 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 715                           i8k_hwmon_set_pwm, 0);
 716 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
 717                           1);
 718 static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
 719                           1);
 720 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 721                           i8k_hwmon_set_pwm, 1);
 722
 723 static struct attribute *i8k_attrs[] = {
 724         &sensor_dev_attr_temp1_input.dev_attr.attr,     /* 0 */
 725         &sensor_dev_attr_temp1_label.dev_attr.attr,     /* 1 */
 726         &sensor_dev_attr_temp2_input.dev_attr.attr,     /* 2 */
 727         &sensor_dev_attr_temp2_label.dev_attr.attr,     /* 3 */
 728         &sensor_dev_attr_temp3_input.dev_attr.attr,     /* 4 */
 729         &sensor_dev_attr_temp3_label.dev_attr.attr,     /* 5 */
 730         &sensor_dev_attr_temp4_input.dev_attr.attr,     /* 6 */
 731         &sensor_dev_attr_temp4_label.dev_attr.attr,     /* 7 */
 732         &sensor_dev_attr_fan1_input.dev_attr.attr,      /* 8 */
 733         &sensor_dev_attr_fan1_label.dev_attr.attr,      /* 9 */
 734         &sensor_dev_attr_pwm1.dev_attr.attr,            /* 10 */
 735         &sensor_dev_attr_fan2_input.dev_attr.attr,      /* 11 */
 736         &sensor_dev_attr_fan2_label.dev_attr.attr,      /* 12 */
 737         &sensor_dev_attr_pwm2.dev_attr.attr,            /* 13 */
 738         NULL
 739 };
 740
 741 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
 742                               int index)
 743 {
 744         if (disallow_fan_type_call &&
 745             (index == 9 || index == 12))
 746                 return 0;
 747         if (index >= 0 && index <= 1 &&
 748             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
 749                 return 0;
 750         if (index >= 2 && index <= 3 &&
 751             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
 752                 return 0;
 753         if (index >= 4 && index <= 5 &&
 754             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
 755                 return 0;
 756         if (index >= 6 && index <= 7 &&
 757             !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
 758                 return 0;
 759         if (index >= 8 && index <= 10 &&
 760             !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
 761                 return 0;
 762         if (index >= 11 && index <= 13 &&
 763             !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
 764                 return 0;
 765
 766         return attr->mode;
 767 }
 768
 769 static const struct attribute_group i8k_group = {
 770         .attrs = i8k_attrs,
 771         .is_visible = i8k_is_visible,
 772 };
 773 __ATTRIBUTE_GROUPS(i8k);
 774
 775 static int __init i8k_init_hwmon(void)
 776 {
 777         int err;
 778
 779         i8k_hwmon_flags = 0;
 780
 781         /* CPU temperature attributes, if temperature type is OK */
 782         err = i8k_get_temp_type(0);
 783         if (err >= 0)
 784                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
 785         /* check for additional temperature sensors */
 786         err = i8k_get_temp_type(1);
 787         if (err >= 0)
 788                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
 789         err = i8k_get_temp_type(2);
 790         if (err >= 0)
 791                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
 792         err = i8k_get_temp_type(3);
 793         if (err >= 0)
 794                 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
 795
 796         /* First fan attributes, if fan status or type is OK */
 797         err = i8k_get_fan_status(0);
 798         if (err < 0)
 799                 err = i8k_get_fan_type(0);
 800         if (err >= 0)
 801                 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
 802
 803         /* Second fan attributes, if fan status or type is OK */
 804         err = i8k_get_fan_status(1);
 805         if (err < 0)
 806                 err = i8k_get_fan_type(1);
 807         if (err >= 0)
 808                 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
 809
 810         i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "dell_smm",
 811                                                           NULL, i8k_groups);
 812         if (IS_ERR(i8k_hwmon_dev)) {
 813                 err = PTR_ERR(i8k_hwmon_dev);
 814                 i8k_hwmon_dev = NULL;
 815                 pr_err("hwmon registration failed (%d)\n", err);
 816                 return err;
 817         }
 818         return 0;
 819 }
 820
 821 struct i8k_config_data {
 822         uint fan_mult;
 823         uint fan_max;
 824 };
 825
 826 enum i8k_configs {
 827         DELL_LATITUDE_D520,
 828         DELL_PRECISION_490,
 829         DELL_STUDIO,
 830         DELL_XPS,
 831 };
 832
 833 static const struct i8k_config_data i8k_config_data[] = {
 834         [DELL_LATITUDE_D520] = {
 835                 .fan_mult = 1,
 836                 .fan_max = I8K_FAN_TURBO,
 837         },
 838         [DELL_PRECISION_490] = {
 839                 .fan_mult = 1,
 840                 .fan_max = I8K_FAN_TURBO,
 841         },
 842         [DELL_STUDIO] = {
 843                 .fan_mult = 1,
 844                 .fan_max = I8K_FAN_HIGH,
 845         },
 846         [DELL_XPS] = {
 847                 .fan_mult = 1,
 848                 .fan_max = I8K_FAN_HIGH,
 849         },
 850 };
 851
 852 static struct dmi_system_id i8k_dmi_table[] __initdata = {
 853         {
 854                 .ident = "Dell Inspiron",
 855                 .matches = {
 856                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 857                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 858                 },
 859         },
 860         {
 861                 .ident = "Dell Latitude",
 862                 .matches = {
 863                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 864                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 865                 },
 866         },
 867         {
 868                 .ident = "Dell Inspiron 2",
 869                 .matches = {
 870                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 871                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 872                 },
 873         },
 874         {
 875                 .ident = "Dell Latitude D520",
 876                 .matches = {
 877                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 878                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
 879                 },
 880                 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
 881         },
 882         {
 883                 .ident = "Dell Latitude 2",
 884                 .matches = {
 885                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 886                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 887                 },
 888         },
 889         {       /* UK Inspiron 6400  */
 890                 .ident = "Dell Inspiron 3",
 891                 .matches = {
 892                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 893                         DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
 894                 },
 895         },
 896         {
 897                 .ident = "Dell Inspiron 3",
 898                 .matches = {
 899                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 900                         DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
 901                 },
 902         },
 903         {
 904                 .ident = "Dell Precision 490",
 905                 .matches = {
 906                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 907                         DMI_MATCH(DMI_PRODUCT_NAME,
 908                                   "Precision WorkStation 490"),
 909                 },
 910                 .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
 911         },
 912         {
 913                 .ident = "Dell Precision",
 914                 .matches = {
 915                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 916                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
 917                 },
 918         },
 919         {
 920                 .ident = "Dell Vostro",
 921                 .matches = {
 922                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 923                         DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
 924                 },
 925         },
 926         {
 927                 .ident = "Dell XPS421",
 928                 .matches = {
 929                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 930                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
 931                 },
 932         },
 933         {
 934                 .ident = "Dell Studio",
 935                 .matches = {
 936                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 937                         DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
 938                 },
 939                 .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
 940         },
 941         {
 942                 .ident = "Dell XPS 13",
 943                 .matches = {
 944                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 945                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS13"),
 946                 },
 947                 .driver_data = (void *)&i8k_config_data[DELL_XPS],
 948         },
 949         {
 950                 .ident = "Dell XPS M140",
 951                 .matches = {
 952                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 953                         DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
 954                 },
 955                 .driver_data = (void *)&i8k_config_data[DELL_XPS],
 956         },
 957         { }
 958 };
 959
 960 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
 961
 962 /*
 963  * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
 964  * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
 965  * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
 966  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
 967  */
 968 static struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initdata = {
 969         {
 970                 .ident = "Dell Studio XPS 8000",
 971                 .matches = {
 972                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 973                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
 974                 },
 975         },
 976         {
 977                 .ident = "Dell Studio XPS 8100",
 978                 .matches = {
 979                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 980                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
 981                 },
 982         },
 983         {
 984                 .ident = "Dell Inspiron 580",
 985                 .matches = {
 986                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 987                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
 988                 },
 989         },
 990         { }
 991 };
 992
 993 /*
 994  * Probe for the presence of a supported laptop.
 995  */
 996 static int __init i8k_probe(void)
 997 {
 998         const struct dmi_system_id *id;
 999         int fan, ret;
1000
1001         /*
1002          * Get DMI information
1003          */
1004         if (!dmi_check_system(i8k_dmi_table)) {
1005                 if (!ignore_dmi && !force)
1006                         return -ENODEV;
1007
1008                 pr_info("not running on a supported Dell system.\n");
1009                 pr_info("vendor=%s, model=%s, version=%s\n",
1010                         i8k_get_dmi_data(DMI_SYS_VENDOR),
1011                         i8k_get_dmi_data(DMI_PRODUCT_NAME),
1012                         i8k_get_dmi_data(DMI_BIOS_VERSION));
1013         }
1014
1015         if (dmi_check_system(i8k_blacklist_fan_type_dmi_table))
1016                 disallow_fan_type_call = true;
1017
1018         strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1019                 sizeof(bios_version));
1020         strlcpy(bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1021                 sizeof(bios_machineid));
1022
1023         /*
1024          * Get SMM Dell signature
1025          */
1026         if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1027             i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1028                 pr_err("unable to get SMM Dell signature\n");
1029                 if (!force)
1030                         return -ENODEV;
1031         }
1032
1033         /*
1034          * Set fan multiplier and maximal fan speed from dmi config
1035          * Values specified in module parameters override values from dmi
1036          */
1037         id = dmi_first_match(i8k_dmi_table);
1038         if (id && id->driver_data) {
1039                 const struct i8k_config_data *conf = id->driver_data;
1040                 if (!fan_mult && conf->fan_mult)
1041                         fan_mult = conf->fan_mult;
1042                 if (!fan_max && conf->fan_max)
1043                         fan_max = conf->fan_max;
1044         }
1045
1046         i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
1047         i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);
1048
1049         if (!fan_mult) {
1050                 /*
1051                  * Autodetect fan multiplier based on nominal rpm
1052                  * If fan reports rpm value too high then set multiplier to 1
1053                  */
1054                 for (fan = 0; fan < 2; ++fan) {
1055                         ret = i8k_get_fan_nominal_speed(fan, i8k_fan_max);
1056                         if (ret < 0)
1057                                 continue;
1058                         if (ret > I8K_FAN_MAX_RPM)
1059                                 i8k_fan_mult = 1;
1060                         break;
1061                 }
1062         } else {
1063                 /* Fan multiplier was specified in module param or in dmi */
1064                 i8k_fan_mult = fan_mult;
1065         }
1066
1067         return 0;
1068 }
1069
1070 static int __init i8k_init(void)
1071 {
1072         int err;
1073
1074         /* Are we running on an supported laptop? */
1075         if (i8k_probe())
1076                 return -ENODEV;
1077
1078         err = i8k_init_hwmon();
1079         if (err)
1080                 return err;
1081
1082         i8k_init_procfs();
1083         return 0;
1084 }
1085
1086 static void __exit i8k_exit(void)
1087 {
1088         hwmon_device_unregister(i8k_hwmon_dev);
1089         i8k_exit_procfs();
1090 }
1091
1092 module_init(i8k_init);
1093 module_exit(i8k_exit);