linux/drivers/hwmon/dell-smm-hwmon.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * dell-smm-hwmon.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
   4 *
   5 * Copyright (C) 2001  Massimo Dal Zotto <dz@debian.org>
   6 *
   7 * Hwmon integration:
   8 * Copyright (C) 2011  Jean Delvare <jdelvare@suse.de>
   9 * Copyright (C) 2013, 2014  Guenter Roeck <linux@roeck-us.net>
  10 * Copyright (C) 2014, 2015  Pali Rohár <pali.rohar@gmail.com>
  11 */
  12
  13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15#include <linux/cpu.h>
  16#include <linux/delay.h>
  17#include <linux/module.h>
  18#include <linux/types.h>
  19#include <linux/init.h>
  20#include <linux/proc_fs.h>
  21#include <linux/seq_file.h>
  22#include <linux/dmi.h>
  23#include <linux/capability.h>
  24#include <linux/mutex.h>
  25#include <linux/hwmon.h>
  26#include <linux/hwmon-sysfs.h>
  27#include <linux/uaccess.h>
  28#include <linux/io.h>
  29#include <linux/sched.h>
  30#include <linux/ctype.h>
  31#include <linux/smp.h>
  32
  33#include <linux/i8k.h>
  34
  35#define I8K_SMM_FN_STATUS       0x0025
  36#define I8K_SMM_POWER_STATUS    0x0069
  37#define I8K_SMM_SET_FAN         0x01a3
  38#define I8K_SMM_GET_FAN         0x00a3
  39#define I8K_SMM_GET_SPEED       0x02a3
  40#define I8K_SMM_GET_FAN_TYPE    0x03a3
  41#define I8K_SMM_GET_NOM_SPEED   0x04a3
  42#define I8K_SMM_GET_TEMP        0x10a3
  43#define I8K_SMM_GET_TEMP_TYPE   0x11a3
  44#define I8K_SMM_GET_DELL_SIG1   0xfea3
  45#define I8K_SMM_GET_DELL_SIG2   0xffa3
  46
  47#define I8K_FAN_MULT            30
  48#define I8K_FAN_MAX_RPM         30000
  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
  61static DEFINE_MUTEX(i8k_mutex);
  62static char bios_version[4];
  63static char bios_machineid[16];
  64static struct device *i8k_hwmon_dev;
  65static u32 i8k_hwmon_flags;
  66static uint i8k_fan_mult = I8K_FAN_MULT;
  67static uint i8k_pwm_mult;
  68static uint i8k_fan_max = I8K_FAN_HIGH;
  69static bool disallow_fan_type_call;
  70static bool disallow_fan_support;
  71static unsigned int manual_fan;
  72static unsigned int auto_fan;
  73
  74#define I8K_HWMON_HAVE_TEMP1    (1 << 0)
  75#define I8K_HWMON_HAVE_TEMP2    (1 << 1)
  76#define I8K_HWMON_HAVE_TEMP3    (1 << 2)
  77#define I8K_HWMON_HAVE_TEMP4    (1 << 3)
  78#define I8K_HWMON_HAVE_TEMP5    (1 << 4)
  79#define I8K_HWMON_HAVE_TEMP6    (1 << 5)
  80#define I8K_HWMON_HAVE_TEMP7    (1 << 6)
  81#define I8K_HWMON_HAVE_TEMP8    (1 << 7)
  82#define I8K_HWMON_HAVE_TEMP9    (1 << 8)
  83#define I8K_HWMON_HAVE_TEMP10   (1 << 9)
  84#define I8K_HWMON_HAVE_FAN1     (1 << 10)
  85#define I8K_HWMON_HAVE_FAN2     (1 << 11)
  86#define I8K_HWMON_HAVE_FAN3     (1 << 12)
  87
  88MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
  89MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
  90MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
  91MODULE_LICENSE("GPL");
  92MODULE_ALIAS("i8k");
  93
  94static bool force;
  95module_param(force, bool, 0);
  96MODULE_PARM_DESC(force, "Force loading without checking for supported models");
  97
  98static bool ignore_dmi;
  99module_param(ignore_dmi, bool, 0);
 100MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
 101
 102#if IS_ENABLED(CONFIG_I8K)
 103static bool restricted = true;
 104module_param(restricted, bool, 0);
 105MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
 106
 107static bool power_status;
 108module_param(power_status, bool, 0600);
 109MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
 110#endif
 111
 112static uint fan_mult;
 113module_param(fan_mult, uint, 0);
 114MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
 115
 116static uint fan_max;
 117module_param(fan_max, uint, 0);
 118MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
 119
 120struct smm_regs {
 121        unsigned int eax;
 122        unsigned int ebx __packed;
 123        unsigned int ecx __packed;
 124        unsigned int edx __packed;
 125        unsigned int esi __packed;
 126        unsigned int edi __packed;
 127};
 128
 129static inline const char *i8k_get_dmi_data(int field)
 130{
 131        const char *dmi_data = dmi_get_system_info(field);
 132
 133        return dmi_data && *dmi_data ? dmi_data : "?";
 134}
 135
 136/*
 137 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
 138 */
 139static int i8k_smm_func(void *par)
 140{
 141        int rc;
 142        struct smm_regs *regs = par;
 143        int eax = regs->eax;
 144
 145#ifdef DEBUG
 146        int ebx = regs->ebx;
 147        unsigned long duration;
 148        ktime_t calltime, delta, rettime;
 149
 150        calltime = ktime_get();
 151#endif
 152
 153        /* SMM requires CPU 0 */
 154        if (smp_processor_id() != 0)
 155                return -EBUSY;
 156
 157#if defined(CONFIG_X86_64)
 158        asm volatile("pushq %%rax\n\t"
 159                "movl 0(%%rax),%%edx\n\t"
 160                "pushq %%rdx\n\t"
 161                "movl 4(%%rax),%%ebx\n\t"
 162                "movl 8(%%rax),%%ecx\n\t"
 163                "movl 12(%%rax),%%edx\n\t"
 164                "movl 16(%%rax),%%esi\n\t"
 165                "movl 20(%%rax),%%edi\n\t"
 166                "popq %%rax\n\t"
 167                "out %%al,$0xb2\n\t"
 168                "out %%al,$0x84\n\t"
 169                "xchgq %%rax,(%%rsp)\n\t"
 170                "movl %%ebx,4(%%rax)\n\t"
 171                "movl %%ecx,8(%%rax)\n\t"
 172                "movl %%edx,12(%%rax)\n\t"
 173                "movl %%esi,16(%%rax)\n\t"
 174                "movl %%edi,20(%%rax)\n\t"
 175                "popq %%rdx\n\t"
 176                "movl %%edx,0(%%rax)\n\t"
 177                "pushfq\n\t"
 178                "popq %%rax\n\t"
 179                "andl $1,%%eax\n"
 180                : "=a"(rc)
 181                :    "a"(regs)
 182                :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 183#else
 184        asm volatile("pushl %%eax\n\t"
 185            "movl 0(%%eax),%%edx\n\t"
 186            "push %%edx\n\t"
 187            "movl 4(%%eax),%%ebx\n\t"
 188            "movl 8(%%eax),%%ecx\n\t"
 189            "movl 12(%%eax),%%edx\n\t"
 190            "movl 16(%%eax),%%esi\n\t"
 191            "movl 20(%%eax),%%edi\n\t"
 192            "popl %%eax\n\t"
 193            "out %%al,$0xb2\n\t"
 194            "out %%al,$0x84\n\t"
 195            "xchgl %%eax,(%%esp)\n\t"
 196            "movl %%ebx,4(%%eax)\n\t"
 197            "movl %%ecx,8(%%eax)\n\t"
 198            "movl %%edx,12(%%eax)\n\t"
 199            "movl %%esi,16(%%eax)\n\t"
 200            "movl %%edi,20(%%eax)\n\t"
 201            "popl %%edx\n\t"
 202            "movl %%edx,0(%%eax)\n\t"
 203            "lahf\n\t"
 204            "shrl $8,%%eax\n\t"
 205            "andl $1,%%eax\n"
 206            : "=a"(rc)
 207            :    "a"(regs)
 208            :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 209#endif
 210        if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
 211                rc = -EINVAL;
 212
 213#ifdef DEBUG
 214        rettime = ktime_get();
 215        delta = ktime_sub(rettime, calltime);
 216        duration = ktime_to_ns(delta) >> 10;
 217        pr_debug("smm(0x%.4x 0x%.4x) = 0x%.4x  (took %7lu usecs)\n", eax, ebx,
 218                (rc ? 0xffff : regs->eax & 0xffff), duration);
 219#endif
 220
 221        return rc;
 222}
 223
 224/*
 225 * Call the System Management Mode BIOS.
 226 */
 227static int i8k_smm(struct smm_regs *regs)
 228{
 229        int ret;
 230
 231        get_online_cpus();
 232        ret = smp_call_on_cpu(0, i8k_smm_func, regs, true);
 233        put_online_cpus();
 234
 235        return ret;
 236}
 237
 238/*
 239 * Read the fan status.
 240 */
 241static int i8k_get_fan_status(int fan)
 242{
 243        struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
 244
 245        if (disallow_fan_support)
 246                return -EINVAL;
 247
 248        regs.ebx = fan & 0xff;
 249        return i8k_smm(&regs) ? : regs.eax & 0xff;
 250}
 251
 252/*
 253 * Read the fan speed in RPM.
 254 */
 255static int i8k_get_fan_speed(int fan)
 256{
 257        struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
 258
 259        if (disallow_fan_support)
 260                return -EINVAL;
 261
 262        regs.ebx = fan & 0xff;
 263        return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 264}
 265
 266/*
 267 * Read the fan type.
 268 */
 269static int _i8k_get_fan_type(int fan)
 270{
 271        struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
 272
 273        if (disallow_fan_support || disallow_fan_type_call)
 274                return -EINVAL;
 275
 276        regs.ebx = fan & 0xff;
 277        return i8k_smm(&regs) ? : regs.eax & 0xff;
 278}
 279
 280static int i8k_get_fan_type(int fan)
 281{
 282        /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
 283        static int types[3] = { INT_MIN, INT_MIN, INT_MIN };
 284
 285        if (types[fan] == INT_MIN)
 286                types[fan] = _i8k_get_fan_type(fan);
 287
 288        return types[fan];
 289}
 290
 291/*
 292 * Read the fan nominal rpm for specific fan speed.
 293 */
 294static int i8k_get_fan_nominal_speed(int fan, int speed)
 295{
 296        struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
 297
 298        if (disallow_fan_support)
 299                return -EINVAL;
 300
 301        regs.ebx = (fan & 0xff) | (speed << 8);
 302        return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 303}
 304
 305/*
 306 * Enable or disable automatic BIOS fan control support
 307 */
 308static int i8k_enable_fan_auto_mode(bool enable)
 309{
 310        struct smm_regs regs = { };
 311
 312        if (disallow_fan_support)
 313                return -EINVAL;
 314
 315        regs.eax = enable ? auto_fan : manual_fan;
 316        return i8k_smm(&regs);
 317}
 318
 319/*
 320 * Set the fan speed (off, low, high). Returns the new fan status.
 321 */
 322static int i8k_set_fan(int fan, int speed)
 323{
 324        struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
 325
 326        if (disallow_fan_support)
 327                return -EINVAL;
 328
 329        speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
 330        regs.ebx = (fan & 0xff) | (speed << 8);
 331
 332        return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
 333}
 334
 335static int i8k_get_temp_type(int sensor)
 336{
 337        struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
 338
 339        regs.ebx = sensor & 0xff;
 340        return i8k_smm(&regs) ? : regs.eax & 0xff;
 341}
 342
 343/*
 344 * Read the cpu temperature.
 345 */
 346static int _i8k_get_temp(int sensor)
 347{
 348        struct smm_regs regs = {
 349                .eax = I8K_SMM_GET_TEMP,
 350                .ebx = sensor & 0xff,
 351        };
 352
 353        return i8k_smm(&regs) ? : regs.eax & 0xff;
 354}
 355
 356static int i8k_get_temp(int sensor)
 357{
 358        int temp = _i8k_get_temp(sensor);
 359
 360        /*
 361         * Sometimes the temperature sensor returns 0x99, which is out of range.
 362         * In this case we retry (once) before returning an error.
 363         # 1003655137 00000058 00005a4b
 364         # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 365         # 1003655139 00000054 00005c52
 366         */
 367        if (temp == 0x99) {
 368                msleep(100);
 369                temp = _i8k_get_temp(sensor);
 370        }
 371        /*
 372         * Return -ENODATA for all invalid temperatures.
 373         *
 374         * Known instances are the 0x99 value as seen above as well as
 375         * 0xc1 (193), which may be returned when trying to read the GPU
 376         * temperature if the system supports a GPU and it is currently
 377         * turned off.
 378         */
 379        if (temp > I8K_MAX_TEMP)
 380                return -ENODATA;
 381
 382        return temp;
 383}
 384
 385static int i8k_get_dell_signature(int req_fn)
 386{
 387        struct smm_regs regs = { .eax = req_fn, };
 388        int rc;
 389
 390        rc = i8k_smm(&regs);
 391        if (rc < 0)
 392                return rc;
 393
 394        return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 395}
 396
 397#if IS_ENABLED(CONFIG_I8K)
 398
 399/*
 400 * Read the Fn key status.
 401 */
 402static int i8k_get_fn_status(void)
 403{
 404        struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
 405        int rc;
 406
 407        rc = i8k_smm(&regs);
 408        if (rc < 0)
 409                return rc;
 410
 411        switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 412        case I8K_FN_UP:
 413                return I8K_VOL_UP;
 414        case I8K_FN_DOWN:
 415                return I8K_VOL_DOWN;
 416        case I8K_FN_MUTE:
 417                return I8K_VOL_MUTE;
 418        default:
 419                return 0;
 420        }
 421}
 422
 423/*
 424 * Read the power status.
 425 */
 426static int i8k_get_power_status(void)
 427{
 428        struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
 429        int rc;
 430
 431        rc = i8k_smm(&regs);
 432        if (rc < 0)
 433                return rc;
 434
 435        return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
 436}
 437
 438/*
 439 * Procfs interface
 440 */
 441
 442static int
 443i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
 444{
 445        int val = 0;
 446        int speed;
 447        unsigned char buff[16];
 448        int __user *argp = (int __user *)arg;
 449
 450        if (!argp)
 451                return -EINVAL;
 452
 453        switch (cmd) {
 454        case I8K_BIOS_VERSION:
 455                if (!isdigit(bios_version[0]) || !isdigit(bios_version[1]) ||
 456                    !isdigit(bios_version[2]))
 457                        return -EINVAL;
 458
 459                val = (bios_version[0] << 16) |
 460                                (bios_version[1] << 8) | bios_version[2];
 461                break;
 462
 463        case I8K_MACHINE_ID:
 464                if (restricted && !capable(CAP_SYS_ADMIN))
 465                        return -EPERM;
 466
 467                memset(buff, 0, sizeof(buff));
 468                strlcpy(buff, bios_machineid, sizeof(buff));
 469                break;
 470
 471        case I8K_FN_STATUS:
 472                val = i8k_get_fn_status();
 473                break;
 474
 475        case I8K_POWER_STATUS:
 476                val = i8k_get_power_status();
 477                break;
 478
 479        case I8K_GET_TEMP:
 480                val = i8k_get_temp(0);
 481                break;
 482
 483        case I8K_GET_SPEED:
 484                if (copy_from_user(&val, argp, sizeof(int)))
 485                        return -EFAULT;
 486
 487                val = i8k_get_fan_speed(val);
 488                break;
 489
 490        case I8K_GET_FAN:
 491                if (copy_from_user(&val, argp, sizeof(int)))
 492                        return -EFAULT;
 493
 494                val = i8k_get_fan_status(val);
 495                break;
 496
 497        case I8K_SET_FAN:
 498                if (restricted && !capable(CAP_SYS_ADMIN))
 499                        return -EPERM;
 500
 501                if (copy_from_user(&val, argp, sizeof(int)))
 502                        return -EFAULT;
 503
 504                if (copy_from_user(&speed, argp + 1, sizeof(int)))
 505                        return -EFAULT;
 506
 507                val = i8k_set_fan(val, speed);
 508                break;
 509
 510        default:
 511                return -EINVAL;
 512        }
 513
 514        if (val < 0)
 515                return val;
 516
 517        switch (cmd) {
 518        case I8K_BIOS_VERSION:
 519                if (copy_to_user(argp, &val, 4))
 520                        return -EFAULT;
 521
 522                break;
 523        case I8K_MACHINE_ID:
 524                if (copy_to_user(argp, buff, 16))
 525                        return -EFAULT;
 526
 527                break;
 528        default:
 529                if (copy_to_user(argp, &val, sizeof(int)))
 530                        return -EFAULT;
 531
 532                break;
 533        }
 534
 535        return 0;
 536}
 537
 538static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 539{
 540        long ret;
 541
 542        mutex_lock(&i8k_mutex);
 543        ret = i8k_ioctl_unlocked(fp, cmd, arg);
 544        mutex_unlock(&i8k_mutex);
 545
 546        return ret;
 547}
 548
 549/*
 550 * Print the information for /proc/i8k.
 551 */
 552static int i8k_proc_show(struct seq_file *seq, void *offset)
 553{
 554        int fn_key, cpu_temp, ac_power;
 555        int left_fan, right_fan, left_speed, right_speed;
 556
 557        cpu_temp        = i8k_get_temp(0);                      /* 11100 µs */
 558        left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
 559        right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
 560        left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
 561        right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
 562        fn_key          = i8k_get_fn_status();                  /*   750 µs */
 563        if (power_status)
 564                ac_power = i8k_get_power_status();              /* 14700 µs */
 565        else
 566                ac_power = -1;
 567
 568        /*
 569         * Info:
 570         *
 571         * 1)  Format version (this will change if format changes)
 572         * 2)  BIOS version
 573         * 3)  BIOS machine ID
 574         * 4)  Cpu temperature
 575         * 5)  Left fan status
 576         * 6)  Right fan status
 577         * 7)  Left fan speed
 578         * 8)  Right fan speed
 579         * 9)  AC power
 580         * 10) Fn Key status
 581         */
 582        seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
 583                   I8K_PROC_FMT,
 584                   bios_version,
 585                   (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : bios_machineid,
 586                   cpu_temp,
 587                   left_fan, right_fan, left_speed, right_speed,
 588                   ac_power, fn_key);
 589
 590        return 0;
 591}
 592
 593static int i8k_open_fs(struct inode *inode, struct file *file)
 594{
 595        return single_open(file, i8k_proc_show, NULL);
 596}
 597
 598static const struct file_operations i8k_fops = {
 599        .owner          = THIS_MODULE,
 600        .open           = i8k_open_fs,
 601        .read           = seq_read,
 602        .llseek         = seq_lseek,
 603        .release        = single_release,
 604        .unlocked_ioctl = i8k_ioctl,
 605};
 606
 607static void __init i8k_init_procfs(void)
 608{
 609        /* Register the proc entry */
 610        proc_create("i8k", 0, NULL, &i8k_fops);
 611}
 612
 613static void __exit i8k_exit_procfs(void)
 614{
 615        remove_proc_entry("i8k", NULL);
 616}
 617
 618#else
 619
 620static inline void __init i8k_init_procfs(void)
 621{
 622}
 623
 624static inline void __exit i8k_exit_procfs(void)
 625{
 626}
 627
 628#endif
 629
 630/*
 631 * Hwmon interface
 632 */
 633
 634static ssize_t i8k_hwmon_temp_label_show(struct device *dev,
 635                                         struct device_attribute *devattr,
 636                                         char *buf)
 637{
 638        static const char * const labels[] = {
 639                "CPU",
 640                "GPU",
 641                "SODIMM",
 642                "Other",
 643                "Ambient",
 644                "Other",
 645        };
 646        int index = to_sensor_dev_attr(devattr)->index;
 647        int type;
 648
 649        type = i8k_get_temp_type(index);
 650        if (type < 0)
 651                return type;
 652        if (type >= ARRAY_SIZE(labels))
 653                type = ARRAY_SIZE(labels) - 1;
 654        return sprintf(buf, "%s\n", labels[type]);
 655}
 656
 657static ssize_t i8k_hwmon_temp_show(struct device *dev,
 658                                   struct device_attribute *devattr,
 659                                   char *buf)
 660{
 661        int index = to_sensor_dev_attr(devattr)->index;
 662        int temp;
 663
 664        temp = i8k_get_temp(index);
 665        if (temp < 0)
 666                return temp;
 667        return sprintf(buf, "%d\n", temp * 1000);
 668}
 669
 670static ssize_t i8k_hwmon_fan_label_show(struct device *dev,
 671                                        struct device_attribute *devattr,
 672                                        char *buf)
 673{
 674        static const char * const labels[] = {
 675                "Processor Fan",
 676                "Motherboard Fan",
 677                "Video Fan",
 678                "Power Supply Fan",
 679                "Chipset Fan",
 680                "Other Fan",
 681        };
 682        int index = to_sensor_dev_attr(devattr)->index;
 683        bool dock = false;
 684        int type;
 685
 686        type = i8k_get_fan_type(index);
 687        if (type < 0)
 688                return type;
 689
 690        if (type & 0x10) {
 691                dock = true;
 692                type &= 0x0F;
 693        }
 694
 695        if (type >= ARRAY_SIZE(labels))
 696                type = (ARRAY_SIZE(labels) - 1);
 697
 698        return sprintf(buf, "%s%s\n", (dock ? "Docking " : ""), labels[type]);
 699}
 700
 701static ssize_t i8k_hwmon_fan_show(struct device *dev,
 702                                  struct device_attribute *devattr, char *buf)
 703{
 704        int index = to_sensor_dev_attr(devattr)->index;
 705        int fan_speed;
 706
 707        fan_speed = i8k_get_fan_speed(index);
 708        if (fan_speed < 0)
 709                return fan_speed;
 710        return sprintf(buf, "%d\n", fan_speed);
 711}
 712
 713static ssize_t i8k_hwmon_pwm_show(struct device *dev,
 714                                  struct device_attribute *devattr, char *buf)
 715{
 716        int index = to_sensor_dev_attr(devattr)->index;
 717        int status;
 718
 719        status = i8k_get_fan_status(index);
 720        if (status < 0)
 721                return -EIO;
 722        return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
 723}
 724
 725static ssize_t i8k_hwmon_pwm_store(struct device *dev,
 726                                   struct device_attribute *attr,
 727                                   const char *buf, size_t count)
 728{
 729        int index = to_sensor_dev_attr(attr)->index;
 730        unsigned long val;
 731        int err;
 732
 733        err = kstrtoul(buf, 10, &val);
 734        if (err)
 735                return err;
 736        val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);
 737
 738        mutex_lock(&i8k_mutex);
 739        err = i8k_set_fan(index, val);
 740        mutex_unlock(&i8k_mutex);
 741
 742        return err < 0 ? -EIO : count;
 743}
 744
 745static ssize_t i8k_hwmon_pwm_enable_store(struct device *dev,
 746                                          struct device_attribute *attr,
 747                                          const char *buf, size_t count)
 748{
 749        int err;
 750        bool enable;
 751        unsigned long val;
 752
 753        if (!auto_fan)
 754                return -ENODEV;
 755
 756        err = kstrtoul(buf, 10, &val);
 757        if (err)
 758                return err;
 759
 760        if (val == 1)
 761                enable = false;
 762        else if (val == 2)
 763                enable = true;
 764        else
 765                return -EINVAL;
 766
 767        mutex_lock(&i8k_mutex);
 768        err = i8k_enable_fan_auto_mode(enable);
 769        mutex_unlock(&i8k_mutex);
 770
 771        return err ? err : count;
 772}
 773
 774static SENSOR_DEVICE_ATTR_RO(temp1_input, i8k_hwmon_temp, 0);
 775static SENSOR_DEVICE_ATTR_RO(temp1_label, i8k_hwmon_temp_label, 0);
 776static SENSOR_DEVICE_ATTR_RO(temp2_input, i8k_hwmon_temp, 1);
 777static SENSOR_DEVICE_ATTR_RO(temp2_label, i8k_hwmon_temp_label, 1);
 778static SENSOR_DEVICE_ATTR_RO(temp3_input, i8k_hwmon_temp, 2);
 779static SENSOR_DEVICE_ATTR_RO(temp3_label, i8k_hwmon_temp_label, 2);
 780static SENSOR_DEVICE_ATTR_RO(temp4_input, i8k_hwmon_temp, 3);
 781static SENSOR_DEVICE_ATTR_RO(temp4_label, i8k_hwmon_temp_label, 3);
 782static SENSOR_DEVICE_ATTR_RO(temp5_input, i8k_hwmon_temp, 4);
 783static SENSOR_DEVICE_ATTR_RO(temp5_label, i8k_hwmon_temp_label, 4);
 784static SENSOR_DEVICE_ATTR_RO(temp6_input, i8k_hwmon_temp, 5);
 785static SENSOR_DEVICE_ATTR_RO(temp6_label, i8k_hwmon_temp_label, 5);
 786static SENSOR_DEVICE_ATTR_RO(temp7_input, i8k_hwmon_temp, 6);
 787static SENSOR_DEVICE_ATTR_RO(temp7_label, i8k_hwmon_temp_label, 6);
 788static SENSOR_DEVICE_ATTR_RO(temp8_input, i8k_hwmon_temp, 7);
 789static SENSOR_DEVICE_ATTR_RO(temp8_label, i8k_hwmon_temp_label, 7);
 790static SENSOR_DEVICE_ATTR_RO(temp9_input, i8k_hwmon_temp, 8);
 791static SENSOR_DEVICE_ATTR_RO(temp9_label, i8k_hwmon_temp_label, 8);
 792static SENSOR_DEVICE_ATTR_RO(temp10_input, i8k_hwmon_temp, 9);
 793static SENSOR_DEVICE_ATTR_RO(temp10_label, i8k_hwmon_temp_label, 9);
 794static SENSOR_DEVICE_ATTR_RO(fan1_input, i8k_hwmon_fan, 0);
 795static SENSOR_DEVICE_ATTR_RO(fan1_label, i8k_hwmon_fan_label, 0);
 796static SENSOR_DEVICE_ATTR_RW(pwm1, i8k_hwmon_pwm, 0);
 797static SENSOR_DEVICE_ATTR_WO(pwm1_enable, i8k_hwmon_pwm_enable, 0);
 798static SENSOR_DEVICE_ATTR_RO(fan2_input, i8k_hwmon_fan, 1);
 799static SENSOR_DEVICE_ATTR_RO(fan2_label, i8k_hwmon_fan_label, 1);
 800static SENSOR_DEVICE_ATTR_RW(pwm2, i8k_hwmon_pwm, 1);
 801static SENSOR_DEVICE_ATTR_RO(fan3_input, i8k_hwmon_fan, 2);
 802static SENSOR_DEVICE_ATTR_RO(fan3_label, i8k_hwmon_fan_label, 2);
 803static SENSOR_DEVICE_ATTR_RW(pwm3, i8k_hwmon_pwm, 2);
 804
 805static struct attribute *i8k_attrs[] = {
 806        &sensor_dev_attr_temp1_input.dev_attr.attr,     /* 0 */
 807        &sensor_dev_attr_temp1_label.dev_attr.attr,     /* 1 */
 808        &sensor_dev_attr_temp2_input.dev_attr.attr,     /* 2 */
 809        &sensor_dev_attr_temp2_label.dev_attr.attr,     /* 3 */
 810        &sensor_dev_attr_temp3_input.dev_attr.attr,     /* 4 */
 811        &sensor_dev_attr_temp3_label.dev_attr.attr,     /* 5 */
 812        &sensor_dev_attr_temp4_input.dev_attr.attr,     /* 6 */
 813        &sensor_dev_attr_temp4_label.dev_attr.attr,     /* 7 */
 814        &sensor_dev_attr_temp5_input.dev_attr.attr,     /* 8 */
 815        &sensor_dev_attr_temp5_label.dev_attr.attr,     /* 9 */
 816        &sensor_dev_attr_temp6_input.dev_attr.attr,     /* 10 */
 817        &sensor_dev_attr_temp6_label.dev_attr.attr,     /* 11 */
 818        &sensor_dev_attr_temp7_input.dev_attr.attr,     /* 12 */
 819        &sensor_dev_attr_temp7_label.dev_attr.attr,     /* 13 */
 820        &sensor_dev_attr_temp8_input.dev_attr.attr,     /* 14 */
 821        &sensor_dev_attr_temp8_label.dev_attr.attr,     /* 15 */
 822        &sensor_dev_attr_temp9_input.dev_attr.attr,     /* 16 */
 823        &sensor_dev_attr_temp9_label.dev_attr.attr,     /* 17 */
 824        &sensor_dev_attr_temp10_input.dev_attr.attr,    /* 18 */
 825        &sensor_dev_attr_temp10_label.dev_attr.attr,    /* 19 */
 826        &sensor_dev_attr_fan1_input.dev_attr.attr,      /* 20 */
 827        &sensor_dev_attr_fan1_label.dev_attr.attr,      /* 21 */
 828        &sensor_dev_attr_pwm1.dev_attr.attr,            /* 22 */
 829        &sensor_dev_attr_pwm1_enable.dev_attr.attr,     /* 23 */
 830        &sensor_dev_attr_fan2_input.dev_attr.attr,      /* 24 */
 831        &sensor_dev_attr_fan2_label.dev_attr.attr,      /* 25 */
 832        &sensor_dev_attr_pwm2.dev_attr.attr,            /* 26 */
 833        &sensor_dev_attr_fan3_input.dev_attr.attr,      /* 27 */
 834        &sensor_dev_attr_fan3_label.dev_attr.attr,      /* 28 */
 835        &sensor_dev_attr_pwm3.dev_attr.attr,            /* 29 */
 836        NULL
 837};
 838
 839static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
 840                              int index)
 841{
 842        if (disallow_fan_support && index >= 8)
 843                return 0;
 844        if (disallow_fan_type_call &&
 845            (index == 9 || index == 12 || index == 15))
 846                return 0;
 847        if (index >= 0 && index <= 1 &&
 848            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
 849                return 0;
 850        if (index >= 2 && index <= 3 &&
 851            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
 852                return 0;
 853        if (index >= 4 && index <= 5 &&
 854            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
 855                return 0;
 856        if (index >= 6 && index <= 7 &&
 857            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
 858                return 0;
 859        if (index >= 8 && index <= 9 &&
 860            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP5))
 861                return 0;
 862        if (index >= 10 && index <= 11 &&
 863            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP6))
 864                return 0;
 865        if (index >= 12 && index <= 13 &&
 866            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP7))
 867                return 0;
 868        if (index >= 14 && index <= 15 &&
 869            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP8))
 870                return 0;
 871        if (index >= 16 && index <= 17 &&
 872            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP9))
 873                return 0;
 874        if (index >= 18 && index <= 19 &&
 875            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP10))
 876                return 0;
 877
 878        if (index >= 20 && index <= 23 &&
 879            !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
 880                return 0;
 881        if (index >= 24 && index <= 26 &&
 882            !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
 883                return 0;
 884        if (index >= 27 && index <= 29 &&
 885            !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN3))
 886                return 0;
 887
 888        if (index == 23 && !auto_fan)
 889                return 0;
 890
 891        return attr->mode;
 892}
 893
 894static const struct attribute_group i8k_group = {
 895        .attrs = i8k_attrs,
 896        .is_visible = i8k_is_visible,
 897};
 898__ATTRIBUTE_GROUPS(i8k);
 899
 900static int __init i8k_init_hwmon(void)
 901{
 902        int err;
 903
 904        i8k_hwmon_flags = 0;
 905
 906        /* CPU temperature attributes, if temperature type is OK */
 907        err = i8k_get_temp_type(0);
 908        if (err >= 0)
 909                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
 910        /* check for additional temperature sensors */
 911        err = i8k_get_temp_type(1);
 912        if (err >= 0)
 913                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
 914        err = i8k_get_temp_type(2);
 915        if (err >= 0)
 916                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
 917        err = i8k_get_temp_type(3);
 918        if (err >= 0)
 919                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
 920        err = i8k_get_temp_type(4);
 921        if (err >= 0)
 922                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP5;
 923        err = i8k_get_temp_type(5);
 924        if (err >= 0)
 925                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP6;
 926        err = i8k_get_temp_type(6);
 927        if (err >= 0)
 928                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP7;
 929        err = i8k_get_temp_type(7);
 930        if (err >= 0)
 931                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP8;
 932        err = i8k_get_temp_type(8);
 933        if (err >= 0)
 934                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP9;
 935        err = i8k_get_temp_type(9);
 936        if (err >= 0)
 937                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP10;
 938
 939        /* First fan attributes, if fan status or type is OK */
 940        err = i8k_get_fan_status(0);
 941        if (err < 0)
 942                err = i8k_get_fan_type(0);
 943        if (err >= 0)
 944                i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
 945
 946        /* Second fan attributes, if fan status or type is OK */
 947        err = i8k_get_fan_status(1);
 948        if (err < 0)
 949                err = i8k_get_fan_type(1);
 950        if (err >= 0)
 951                i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
 952
 953        /* Third fan attributes, if fan status or type is OK */
 954        err = i8k_get_fan_status(2);
 955        if (err < 0)
 956                err = i8k_get_fan_type(2);
 957        if (err >= 0)
 958                i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN3;
 959
 960        i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "dell_smm",
 961                                                          NULL, i8k_groups);
 962        if (IS_ERR(i8k_hwmon_dev)) {
 963                err = PTR_ERR(i8k_hwmon_dev);
 964                i8k_hwmon_dev = NULL;
 965                pr_err("hwmon registration failed (%d)\n", err);
 966                return err;
 967        }
 968        return 0;
 969}
 970
 971struct i8k_config_data {
 972        uint fan_mult;
 973        uint fan_max;
 974};
 975
 976enum i8k_configs {
 977        DELL_LATITUDE_D520,
 978        DELL_PRECISION_490,
 979        DELL_STUDIO,
 980        DELL_XPS,
 981};
 982
 983static const struct i8k_config_data i8k_config_data[] = {
 984        [DELL_LATITUDE_D520] = {
 985                .fan_mult = 1,
 986                .fan_max = I8K_FAN_TURBO,
 987        },
 988        [DELL_PRECISION_490] = {
 989                .fan_mult = 1,
 990                .fan_max = I8K_FAN_TURBO,
 991        },
 992        [DELL_STUDIO] = {
 993                .fan_mult = 1,
 994                .fan_max = I8K_FAN_HIGH,
 995        },
 996        [DELL_XPS] = {
 997                .fan_mult = 1,
 998                .fan_max = I8K_FAN_HIGH,
 999        },
1000};
1001
1002static const struct dmi_system_id i8k_dmi_table[] __initconst = {
1003        {
1004                .ident = "Dell Inspiron",
1005                .matches = {
1006                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1007                        DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1008                },
1009        },
1010        {
1011                .ident = "Dell Latitude",
1012                .matches = {
1013                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1014                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1015                },
1016        },
1017        {
1018                .ident = "Dell Inspiron 2",
1019                .matches = {
1020                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1021                        DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1022                },
1023        },
1024        {
1025                .ident = "Dell Latitude D520",
1026                .matches = {
1027                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1028                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
1029                },
1030                .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
1031        },
1032        {
1033                .ident = "Dell Latitude 2",
1034                .matches = {
1035                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1036                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1037                },
1038        },
1039        {       /* UK Inspiron 6400  */
1040                .ident = "Dell Inspiron 3",
1041                .matches = {
1042                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1043                        DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1044                },
1045        },
1046        {
1047                .ident = "Dell Inspiron 3",
1048                .matches = {
1049                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1050                        DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1051                },
1052        },
1053        {
1054                .ident = "Dell Precision 490",
1055                .matches = {
1056                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1057                        DMI_MATCH(DMI_PRODUCT_NAME,
1058                                  "Precision WorkStation 490"),
1059                },
1060                .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1061        },
1062        {
1063                .ident = "Dell Precision",
1064                .matches = {
1065                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1066                        DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1067                },
1068        },
1069        {
1070                .ident = "Dell Vostro",
1071                .matches = {
1072                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1073                        DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1074                },
1075        },
1076        {
1077                .ident = "Dell XPS421",
1078                .matches = {
1079                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1080                        DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
1081                },
1082        },
1083        {
1084                .ident = "Dell Studio",
1085                .matches = {
1086                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1087                        DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1088                },
1089                .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1090        },
1091        {
1092                .ident = "Dell XPS 13",
1093                .matches = {
1094                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1095                        DMI_MATCH(DMI_PRODUCT_NAME, "XPS13"),
1096                },
1097                .driver_data = (void *)&i8k_config_data[DELL_XPS],
1098        },
1099        {
1100                .ident = "Dell XPS M140",
1101                .matches = {
1102                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1103                        DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1104                },
1105                .driver_data = (void *)&i8k_config_data[DELL_XPS],
1106        },
1107        {
1108                .ident = "Dell XPS 15 9560",
1109                .matches = {
1110                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1111                        DMI_MATCH(DMI_PRODUCT_NAME, "XPS 15 9560"),
1112                },
1113        },
1114        {
1115                .ident = "Dell XPS 15 9570",
1116                .matches = {
1117                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1118                        DMI_MATCH(DMI_PRODUCT_NAME, "XPS 15 9570"),
1119                },
1120        },
1121        { }
1122};
1123
1124MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1125
1126/*
1127 * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1128 * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1129 * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1130 * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1131 */
1132static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1133        {
1134                .ident = "Dell Studio XPS 8000",
1135                .matches = {
1136                        DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1137                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1138                },
1139        },
1140        {
1141                .ident = "Dell Studio XPS 8100",
1142                .matches = {
1143                        DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1144                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1145                },
1146        },
1147        {
1148                .ident = "Dell Inspiron 580",
1149                .matches = {
1150                        DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1151                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1152                },
1153        },
1154        { }
1155};
1156
1157/*
1158 * On some machines all fan related SMM functions implemented by Dell BIOS
1159 * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1160 * support for affected blacklisted Dell machines stay disabled.
1161 * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1162 */
1163static struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initdata = {
1164        {
1165                .ident = "Dell Inspiron 7720",
1166                .matches = {
1167                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1168                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1169                },
1170        },
1171        {
1172                .ident = "Dell Vostro 3360",
1173                .matches = {
1174                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1175                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1176                },
1177        },
1178        {
1179                .ident = "Dell XPS13 9333",
1180                .matches = {
1181                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1182                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1183                },
1184        },
1185        { }
1186};
1187
1188struct i8k_fan_control_data {
1189        unsigned int manual_fan;
1190        unsigned int auto_fan;
1191};
1192
1193enum i8k_fan_controls {
1194        I8K_FAN_34A3_35A3,
1195};
1196
1197static const struct i8k_fan_control_data i8k_fan_control_data[] = {
1198        [I8K_FAN_34A3_35A3] = {
1199                .manual_fan = 0x34a3,
1200                .auto_fan = 0x35a3,
1201        },
1202};
1203
1204static struct dmi_system_id i8k_whitelist_fan_control[] __initdata = {
1205        {
1206                .ident = "Dell Precision 5530",
1207                .matches = {
1208                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1209                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1210                },
1211                .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1212        },
1213        {
1214                .ident = "Dell Latitude E6440",
1215                .matches = {
1216                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1217                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1218                },
1219                .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1220        },
1221        { }
1222};
1223
1224/*
1225 * Probe for the presence of a supported laptop.
1226 */
1227static int __init i8k_probe(void)
1228{
1229        const struct dmi_system_id *id, *fan_control;
1230        int fan, ret;
1231
1232        /*
1233         * Get DMI information
1234         */
1235        if (!dmi_check_system(i8k_dmi_table)) {
1236                if (!ignore_dmi && !force)
1237                        return -ENODEV;
1238
1239                pr_info("not running on a supported Dell system.\n");
1240                pr_info("vendor=%s, model=%s, version=%s\n",
1241                        i8k_get_dmi_data(DMI_SYS_VENDOR),
1242                        i8k_get_dmi_data(DMI_PRODUCT_NAME),
1243                        i8k_get_dmi_data(DMI_BIOS_VERSION));
1244        }
1245
1246        if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
1247                pr_warn("broken Dell BIOS detected, disallow fan support\n");
1248                if (!force)
1249                        disallow_fan_support = true;
1250        }
1251
1252        if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
1253                pr_warn("broken Dell BIOS detected, disallow fan type call\n");
1254                if (!force)
1255                        disallow_fan_type_call = true;
1256        }
1257
1258        strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1259                sizeof(bios_version));
1260        strlcpy(bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1261                sizeof(bios_machineid));
1262
1263        /*
1264         * Get SMM Dell signature
1265         */
1266        if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1267            i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1268                pr_err("unable to get SMM Dell signature\n");
1269                if (!force)
1270                        return -ENODEV;
1271        }
1272
1273        /*
1274         * Set fan multiplier and maximal fan speed from dmi config
1275         * Values specified in module parameters override values from dmi
1276         */
1277        id = dmi_first_match(i8k_dmi_table);
1278        if (id && id->driver_data) {
1279                const struct i8k_config_data *conf = id->driver_data;
1280                if (!fan_mult && conf->fan_mult)
1281                        fan_mult = conf->fan_mult;
1282                if (!fan_max && conf->fan_max)
1283                        fan_max = conf->fan_max;
1284        }
1285
1286        i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
1287        i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);
1288
1289        fan_control = dmi_first_match(i8k_whitelist_fan_control);
1290        if (fan_control && fan_control->driver_data) {
1291                const struct i8k_fan_control_data *data = fan_control->driver_data;
1292
1293                manual_fan = data->manual_fan;
1294                auto_fan = data->auto_fan;
1295                pr_info("enabling support for setting automatic/manual fan control\n");
1296        }
1297
1298        if (!fan_mult) {
1299                /*
1300                 * Autodetect fan multiplier based on nominal rpm
1301                 * If fan reports rpm value too high then set multiplier to 1
1302                 */
1303                for (fan = 0; fan < 2; ++fan) {
1304                        ret = i8k_get_fan_nominal_speed(fan, i8k_fan_max);
1305                        if (ret < 0)
1306                                continue;
1307                        if (ret > I8K_FAN_MAX_RPM)
1308                                i8k_fan_mult = 1;
1309                        break;
1310                }
1311        } else {
1312                /* Fan multiplier was specified in module param or in dmi */
1313                i8k_fan_mult = fan_mult;
1314        }
1315
1316        return 0;
1317}
1318
1319static int __init i8k_init(void)
1320{
1321        int err;
1322
1323        /* Are we running on an supported laptop? */
1324        if (i8k_probe())
1325                return -ENODEV;
1326
1327        err = i8k_init_hwmon();
1328        if (err)
1329                return err;
1330
1331        i8k_init_procfs();
1332        return 0;
1333}
1334
1335static void __exit i8k_exit(void)
1336{
1337        hwmon_device_unregister(i8k_hwmon_dev);
1338        i8k_exit_procfs();
1339}
1340
1341module_init(i8k_init);
1342module_exit(i8k_exit);
1343