linux/drivers/hwmon/dell-smm-hwmon.c
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   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/cpu.h>
  25#include <linux/delay.h>
  26#include <linux/module.h>
  27#include <linux/types.h>
  28#include <linux/init.h>
  29#include <linux/proc_fs.h>
  30#include <linux/seq_file.h>
  31#include <linux/dmi.h>
  32#include <linux/capability.h>
  33#include <linux/mutex.h>
  34#include <linux/hwmon.h>
  35#include <linux/hwmon-sysfs.h>
  36#include <linux/uaccess.h>
  37#include <linux/io.h>
  38#include <linux/sched.h>
  39#include <linux/ctype.h>
  40#include <linux/smp.h>
  41
  42#include <linux/i8k.h>
  43
  44#define I8K_SMM_FN_STATUS       0x0025
  45#define I8K_SMM_POWER_STATUS    0x0069
  46#define I8K_SMM_SET_FAN         0x01a3
  47#define I8K_SMM_GET_FAN         0x00a3
  48#define I8K_SMM_GET_SPEED       0x02a3
  49#define I8K_SMM_GET_FAN_TYPE    0x03a3
  50#define I8K_SMM_GET_NOM_SPEED   0x04a3
  51#define I8K_SMM_GET_TEMP        0x10a3
  52#define I8K_SMM_GET_TEMP_TYPE   0x11a3
  53#define I8K_SMM_GET_DELL_SIG1   0xfea3
  54#define I8K_SMM_GET_DELL_SIG2   0xffa3
  55
  56#define I8K_FAN_MULT            30
  57#define I8K_FAN_MAX_RPM         30000
  58#define I8K_MAX_TEMP            127
  59
  60#define I8K_FN_NONE             0x00
  61#define I8K_FN_UP               0x01
  62#define I8K_FN_DOWN             0x02
  63#define I8K_FN_MUTE             0x04
  64#define I8K_FN_MASK             0x07
  65#define I8K_FN_SHIFT            8
  66
  67#define I8K_POWER_AC            0x05
  68#define I8K_POWER_BATTERY       0x01
  69
  70static DEFINE_MUTEX(i8k_mutex);
  71static char bios_version[4];
  72static char bios_machineid[16];
  73static struct device *i8k_hwmon_dev;
  74static u32 i8k_hwmon_flags;
  75static uint i8k_fan_mult = I8K_FAN_MULT;
  76static uint i8k_pwm_mult;
  77static uint i8k_fan_max = I8K_FAN_HIGH;
  78static bool disallow_fan_type_call;
  79
  80#define I8K_HWMON_HAVE_TEMP1    (1 << 0)
  81#define I8K_HWMON_HAVE_TEMP2    (1 << 1)
  82#define I8K_HWMON_HAVE_TEMP3    (1 << 2)
  83#define I8K_HWMON_HAVE_TEMP4    (1 << 3)
  84#define I8K_HWMON_HAVE_FAN1     (1 << 4)
  85#define I8K_HWMON_HAVE_FAN2     (1 << 5)
  86#define I8K_HWMON_HAVE_FAN3     (1 << 6)
  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        regs.ebx = fan & 0xff;
 246        return i8k_smm(&regs) ? : regs.eax & 0xff;
 247}
 248
 249/*
 250 * Read the fan speed in RPM.
 251 */
 252static int i8k_get_fan_speed(int fan)
 253{
 254        struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
 255
 256        regs.ebx = fan & 0xff;
 257        return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 258}
 259
 260/*
 261 * Read the fan type.
 262 */
 263static int _i8k_get_fan_type(int fan)
 264{
 265        struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
 266
 267        if (disallow_fan_type_call)
 268                return -EINVAL;
 269
 270        regs.ebx = fan & 0xff;
 271        return i8k_smm(&regs) ? : regs.eax & 0xff;
 272}
 273
 274static int i8k_get_fan_type(int fan)
 275{
 276        /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
 277        static int types[3] = { INT_MIN, INT_MIN, INT_MIN };
 278
 279        if (types[fan] == INT_MIN)
 280                types[fan] = _i8k_get_fan_type(fan);
 281
 282        return types[fan];
 283}
 284
 285/*
 286 * Read the fan nominal rpm for specific fan speed.
 287 */
 288static int i8k_get_fan_nominal_speed(int fan, int speed)
 289{
 290        struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
 291
 292        regs.ebx = (fan & 0xff) | (speed << 8);
 293        return i8k_smm(&regs) ? : (regs.eax & 0xffff) * i8k_fan_mult;
 294}
 295
 296/*
 297 * Set the fan speed (off, low, high). Returns the new fan status.
 298 */
 299static int i8k_set_fan(int fan, int speed)
 300{
 301        struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
 302
 303        speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
 304        regs.ebx = (fan & 0xff) | (speed << 8);
 305
 306        return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
 307}
 308
 309static int i8k_get_temp_type(int sensor)
 310{
 311        struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
 312
 313        regs.ebx = sensor & 0xff;
 314        return i8k_smm(&regs) ? : regs.eax & 0xff;
 315}
 316
 317/*
 318 * Read the cpu temperature.
 319 */
 320static int _i8k_get_temp(int sensor)
 321{
 322        struct smm_regs regs = {
 323                .eax = I8K_SMM_GET_TEMP,
 324                .ebx = sensor & 0xff,
 325        };
 326
 327        return i8k_smm(&regs) ? : regs.eax & 0xff;
 328}
 329
 330static int i8k_get_temp(int sensor)
 331{
 332        int temp = _i8k_get_temp(sensor);
 333
 334        /*
 335         * Sometimes the temperature sensor returns 0x99, which is out of range.
 336         * In this case we retry (once) before returning an error.
 337         # 1003655137 00000058 00005a4b
 338         # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 339         # 1003655139 00000054 00005c52
 340         */
 341        if (temp == 0x99) {
 342                msleep(100);
 343                temp = _i8k_get_temp(sensor);
 344        }
 345        /*
 346         * Return -ENODATA for all invalid temperatures.
 347         *
 348         * Known instances are the 0x99 value as seen above as well as
 349         * 0xc1 (193), which may be returned when trying to read the GPU
 350         * temperature if the system supports a GPU and it is currently
 351         * turned off.
 352         */
 353        if (temp > I8K_MAX_TEMP)
 354                return -ENODATA;
 355
 356        return temp;
 357}
 358
 359static int i8k_get_dell_signature(int req_fn)
 360{
 361        struct smm_regs regs = { .eax = req_fn, };
 362        int rc;
 363
 364        rc = i8k_smm(&regs);
 365        if (rc < 0)
 366                return rc;
 367
 368        return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 369}
 370
 371#if IS_ENABLED(CONFIG_I8K)
 372
 373/*
 374 * Read the Fn key status.
 375 */
 376static int i8k_get_fn_status(void)
 377{
 378        struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
 379        int rc;
 380
 381        rc = i8k_smm(&regs);
 382        if (rc < 0)
 383                return rc;
 384
 385        switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 386        case I8K_FN_UP:
 387                return I8K_VOL_UP;
 388        case I8K_FN_DOWN:
 389                return I8K_VOL_DOWN;
 390        case I8K_FN_MUTE:
 391                return I8K_VOL_MUTE;
 392        default:
 393                return 0;
 394        }
 395}
 396
 397/*
 398 * Read the power status.
 399 */
 400static int i8k_get_power_status(void)
 401{
 402        struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
 403        int rc;
 404
 405        rc = i8k_smm(&regs);
 406        if (rc < 0)
 407                return rc;
 408
 409        return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
 410}
 411
 412/*
 413 * Procfs interface
 414 */
 415
 416static int
 417i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
 418{
 419        int val = 0;
 420        int speed;
 421        unsigned char buff[16];
 422        int __user *argp = (int __user *)arg;
 423
 424        if (!argp)
 425                return -EINVAL;
 426
 427        switch (cmd) {
 428        case I8K_BIOS_VERSION:
 429                if (!isdigit(bios_version[0]) || !isdigit(bios_version[1]) ||
 430                    !isdigit(bios_version[2]))
 431                        return -EINVAL;
 432
 433                val = (bios_version[0] << 16) |
 434                                (bios_version[1] << 8) | bios_version[2];
 435                break;
 436
 437        case I8K_MACHINE_ID:
 438                if (restricted && !capable(CAP_SYS_ADMIN))
 439                        return -EPERM;
 440
 441                memset(buff, 0, sizeof(buff));
 442                strlcpy(buff, bios_machineid, sizeof(buff));
 443                break;
 444
 445        case I8K_FN_STATUS:
 446                val = i8k_get_fn_status();
 447                break;
 448
 449        case I8K_POWER_STATUS:
 450                val = i8k_get_power_status();
 451                break;
 452
 453        case I8K_GET_TEMP:
 454                val = i8k_get_temp(0);
 455                break;
 456
 457        case I8K_GET_SPEED:
 458                if (copy_from_user(&val, argp, sizeof(int)))
 459                        return -EFAULT;
 460
 461                val = i8k_get_fan_speed(val);
 462                break;
 463
 464        case I8K_GET_FAN:
 465                if (copy_from_user(&val, argp, sizeof(int)))
 466                        return -EFAULT;
 467
 468                val = i8k_get_fan_status(val);
 469                break;
 470
 471        case I8K_SET_FAN:
 472                if (restricted && !capable(CAP_SYS_ADMIN))
 473                        return -EPERM;
 474
 475                if (copy_from_user(&val, argp, sizeof(int)))
 476                        return -EFAULT;
 477
 478                if (copy_from_user(&speed, argp + 1, sizeof(int)))
 479                        return -EFAULT;
 480
 481                val = i8k_set_fan(val, speed);
 482                break;
 483
 484        default:
 485                return -EINVAL;
 486        }
 487
 488        if (val < 0)
 489                return val;
 490
 491        switch (cmd) {
 492        case I8K_BIOS_VERSION:
 493                if (copy_to_user(argp, &val, 4))
 494                        return -EFAULT;
 495
 496                break;
 497        case I8K_MACHINE_ID:
 498                if (copy_to_user(argp, buff, 16))
 499                        return -EFAULT;
 500
 501                break;
 502        default:
 503                if (copy_to_user(argp, &val, sizeof(int)))
 504                        return -EFAULT;
 505
 506                break;
 507        }
 508
 509        return 0;
 510}
 511
 512static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 513{
 514        long ret;
 515
 516        mutex_lock(&i8k_mutex);
 517        ret = i8k_ioctl_unlocked(fp, cmd, arg);
 518        mutex_unlock(&i8k_mutex);
 519
 520        return ret;
 521}
 522
 523/*
 524 * Print the information for /proc/i8k.
 525 */
 526static int i8k_proc_show(struct seq_file *seq, void *offset)
 527{
 528        int fn_key, cpu_temp, ac_power;
 529        int left_fan, right_fan, left_speed, right_speed;
 530
 531        cpu_temp        = i8k_get_temp(0);                      /* 11100 µs */
 532        left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
 533        right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
 534        left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
 535        right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
 536        fn_key          = i8k_get_fn_status();                  /*   750 µs */
 537        if (power_status)
 538                ac_power = i8k_get_power_status();              /* 14700 µs */
 539        else
 540                ac_power = -1;
 541
 542        /*
 543         * Info:
 544         *
 545         * 1)  Format version (this will change if format changes)
 546         * 2)  BIOS version
 547         * 3)  BIOS machine ID
 548         * 4)  Cpu temperature
 549         * 5)  Left fan status
 550         * 6)  Right fan status
 551         * 7)  Left fan speed
 552         * 8)  Right fan speed
 553         * 9)  AC power
 554         * 10) Fn Key status
 555         */
 556        seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
 557                   I8K_PROC_FMT,
 558                   bios_version,
 559                   (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : bios_machineid,
 560                   cpu_temp,
 561                   left_fan, right_fan, left_speed, right_speed,
 562                   ac_power, fn_key);
 563
 564        return 0;
 565}
 566
 567static int i8k_open_fs(struct inode *inode, struct file *file)
 568{
 569        return single_open(file, i8k_proc_show, NULL);
 570}
 571
 572static const struct file_operations i8k_fops = {
 573        .owner          = THIS_MODULE,
 574        .open           = i8k_open_fs,
 575        .read           = seq_read,
 576        .llseek         = seq_lseek,
 577        .release        = single_release,
 578        .unlocked_ioctl = i8k_ioctl,
 579};
 580
 581static void __init i8k_init_procfs(void)
 582{
 583        /* Register the proc entry */
 584        proc_create("i8k", 0, NULL, &i8k_fops);
 585}
 586
 587static void __exit i8k_exit_procfs(void)
 588{
 589        remove_proc_entry("i8k", NULL);
 590}
 591
 592#else
 593
 594static inline void __init i8k_init_procfs(void)
 595{
 596}
 597
 598static inline void __exit i8k_exit_procfs(void)
 599{
 600}
 601
 602#endif
 603
 604/*
 605 * Hwmon interface
 606 */
 607
 608static ssize_t i8k_hwmon_show_temp_label(struct device *dev,
 609                                         struct device_attribute *devattr,
 610                                         char *buf)
 611{
 612        static const char * const labels[] = {
 613                "CPU",
 614                "GPU",
 615                "SODIMM",
 616                "Other",
 617                "Ambient",
 618                "Other",
 619        };
 620        int index = to_sensor_dev_attr(devattr)->index;
 621        int type;
 622
 623        type = i8k_get_temp_type(index);
 624        if (type < 0)
 625                return type;
 626        if (type >= ARRAY_SIZE(labels))
 627                type = ARRAY_SIZE(labels) - 1;
 628        return sprintf(buf, "%s\n", labels[type]);
 629}
 630
 631static ssize_t i8k_hwmon_show_temp(struct device *dev,
 632                                   struct device_attribute *devattr,
 633                                   char *buf)
 634{
 635        int index = to_sensor_dev_attr(devattr)->index;
 636        int temp;
 637
 638        temp = i8k_get_temp(index);
 639        if (temp < 0)
 640                return temp;
 641        return sprintf(buf, "%d\n", temp * 1000);
 642}
 643
 644static ssize_t i8k_hwmon_show_fan_label(struct device *dev,
 645                                        struct device_attribute *devattr,
 646                                        char *buf)
 647{
 648        static const char * const labels[] = {
 649                "Processor Fan",
 650                "Motherboard Fan",
 651                "Video Fan",
 652                "Power Supply Fan",
 653                "Chipset Fan",
 654                "Other Fan",
 655        };
 656        int index = to_sensor_dev_attr(devattr)->index;
 657        bool dock = false;
 658        int type;
 659
 660        type = i8k_get_fan_type(index);
 661        if (type < 0)
 662                return type;
 663
 664        if (type & 0x10) {
 665                dock = true;
 666                type &= 0x0F;
 667        }
 668
 669        if (type >= ARRAY_SIZE(labels))
 670                type = (ARRAY_SIZE(labels) - 1);
 671
 672        return sprintf(buf, "%s%s\n", (dock ? "Docking " : ""), labels[type]);
 673}
 674
 675static ssize_t i8k_hwmon_show_fan(struct device *dev,
 676                                  struct device_attribute *devattr,
 677                                  char *buf)
 678{
 679        int index = to_sensor_dev_attr(devattr)->index;
 680        int fan_speed;
 681
 682        fan_speed = i8k_get_fan_speed(index);
 683        if (fan_speed < 0)
 684                return fan_speed;
 685        return sprintf(buf, "%d\n", fan_speed);
 686}
 687
 688static ssize_t i8k_hwmon_show_pwm(struct device *dev,
 689                                  struct device_attribute *devattr,
 690                                  char *buf)
 691{
 692        int index = to_sensor_dev_attr(devattr)->index;
 693        int status;
 694
 695        status = i8k_get_fan_status(index);
 696        if (status < 0)
 697                return -EIO;
 698        return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
 699}
 700
 701static ssize_t i8k_hwmon_set_pwm(struct device *dev,
 702                                 struct device_attribute *attr,
 703                                 const char *buf, size_t count)
 704{
 705        int index = to_sensor_dev_attr(attr)->index;
 706        unsigned long val;
 707        int err;
 708
 709        err = kstrtoul(buf, 10, &val);
 710        if (err)
 711                return err;
 712        val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);
 713
 714        mutex_lock(&i8k_mutex);
 715        err = i8k_set_fan(index, val);
 716        mutex_unlock(&i8k_mutex);
 717
 718        return err < 0 ? -EIO : count;
 719}
 720
 721static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
 722static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 723                          0);
 724static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
 725static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 726                          1);
 727static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
 728static SENSOR_DEVICE_ATTR(temp3_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 729                          2);
 730static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
 731static SENSOR_DEVICE_ATTR(temp4_label, S_IRUGO, i8k_hwmon_show_temp_label, NULL,
 732                          3);
 733static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL, 0);
 734static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
 735                          0);
 736static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 737                          i8k_hwmon_set_pwm, 0);
 738static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
 739                          1);
 740static SENSOR_DEVICE_ATTR(fan2_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
 741                          1);
 742static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 743                          i8k_hwmon_set_pwm, 1);
 744static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
 745                          2);
 746static SENSOR_DEVICE_ATTR(fan3_label, S_IRUGO, i8k_hwmon_show_fan_label, NULL,
 747                          2);
 748static SENSOR_DEVICE_ATTR(pwm3, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
 749                          i8k_hwmon_set_pwm, 2);
 750
 751static struct attribute *i8k_attrs[] = {
 752        &sensor_dev_attr_temp1_input.dev_attr.attr,     /* 0 */
 753        &sensor_dev_attr_temp1_label.dev_attr.attr,     /* 1 */
 754        &sensor_dev_attr_temp2_input.dev_attr.attr,     /* 2 */
 755        &sensor_dev_attr_temp2_label.dev_attr.attr,     /* 3 */
 756        &sensor_dev_attr_temp3_input.dev_attr.attr,     /* 4 */
 757        &sensor_dev_attr_temp3_label.dev_attr.attr,     /* 5 */
 758        &sensor_dev_attr_temp4_input.dev_attr.attr,     /* 6 */
 759        &sensor_dev_attr_temp4_label.dev_attr.attr,     /* 7 */
 760        &sensor_dev_attr_fan1_input.dev_attr.attr,      /* 8 */
 761        &sensor_dev_attr_fan1_label.dev_attr.attr,      /* 9 */
 762        &sensor_dev_attr_pwm1.dev_attr.attr,            /* 10 */
 763        &sensor_dev_attr_fan2_input.dev_attr.attr,      /* 11 */
 764        &sensor_dev_attr_fan2_label.dev_attr.attr,      /* 12 */
 765        &sensor_dev_attr_pwm2.dev_attr.attr,            /* 13 */
 766        &sensor_dev_attr_fan3_input.dev_attr.attr,      /* 14 */
 767        &sensor_dev_attr_fan3_label.dev_attr.attr,      /* 15 */
 768        &sensor_dev_attr_pwm3.dev_attr.attr,            /* 16 */
 769        NULL
 770};
 771
 772static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
 773                              int index)
 774{
 775        if (disallow_fan_type_call &&
 776            (index == 9 || index == 12 || index == 15))
 777                return 0;
 778        if (index >= 0 && index <= 1 &&
 779            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
 780                return 0;
 781        if (index >= 2 && index <= 3 &&
 782            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
 783                return 0;
 784        if (index >= 4 && index <= 5 &&
 785            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
 786                return 0;
 787        if (index >= 6 && index <= 7 &&
 788            !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
 789                return 0;
 790        if (index >= 8 && index <= 10 &&
 791            !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
 792                return 0;
 793        if (index >= 11 && index <= 13 &&
 794            !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
 795                return 0;
 796        if (index >= 14 && index <= 16 &&
 797            !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN3))
 798                return 0;
 799
 800        return attr->mode;
 801}
 802
 803static const struct attribute_group i8k_group = {
 804        .attrs = i8k_attrs,
 805        .is_visible = i8k_is_visible,
 806};
 807__ATTRIBUTE_GROUPS(i8k);
 808
 809static int __init i8k_init_hwmon(void)
 810{
 811        int err;
 812
 813        i8k_hwmon_flags = 0;
 814
 815        /* CPU temperature attributes, if temperature type is OK */
 816        err = i8k_get_temp_type(0);
 817        if (err >= 0)
 818                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
 819        /* check for additional temperature sensors */
 820        err = i8k_get_temp_type(1);
 821        if (err >= 0)
 822                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
 823        err = i8k_get_temp_type(2);
 824        if (err >= 0)
 825                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
 826        err = i8k_get_temp_type(3);
 827        if (err >= 0)
 828                i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
 829
 830        /* First fan attributes, if fan status or type is OK */
 831        err = i8k_get_fan_status(0);
 832        if (err < 0)
 833                err = i8k_get_fan_type(0);
 834        if (err >= 0)
 835                i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
 836
 837        /* Second fan attributes, if fan status or type is OK */
 838        err = i8k_get_fan_status(1);
 839        if (err < 0)
 840                err = i8k_get_fan_type(1);
 841        if (err >= 0)
 842                i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
 843
 844        /* Third fan attributes, if fan status or type is OK */
 845        err = i8k_get_fan_status(2);
 846        if (err < 0)
 847                err = i8k_get_fan_type(2);
 848        if (err >= 0)
 849                i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN3;
 850
 851        i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "dell_smm",
 852                                                          NULL, i8k_groups);
 853        if (IS_ERR(i8k_hwmon_dev)) {
 854                err = PTR_ERR(i8k_hwmon_dev);
 855                i8k_hwmon_dev = NULL;
 856                pr_err("hwmon registration failed (%d)\n", err);
 857                return err;
 858        }
 859        return 0;
 860}
 861
 862struct i8k_config_data {
 863        uint fan_mult;
 864        uint fan_max;
 865};
 866
 867enum i8k_configs {
 868        DELL_LATITUDE_D520,
 869        DELL_PRECISION_490,
 870        DELL_STUDIO,
 871        DELL_XPS,
 872};
 873
 874static const struct i8k_config_data i8k_config_data[] = {
 875        [DELL_LATITUDE_D520] = {
 876                .fan_mult = 1,
 877                .fan_max = I8K_FAN_TURBO,
 878        },
 879        [DELL_PRECISION_490] = {
 880                .fan_mult = 1,
 881                .fan_max = I8K_FAN_TURBO,
 882        },
 883        [DELL_STUDIO] = {
 884                .fan_mult = 1,
 885                .fan_max = I8K_FAN_HIGH,
 886        },
 887        [DELL_XPS] = {
 888                .fan_mult = 1,
 889                .fan_max = I8K_FAN_HIGH,
 890        },
 891};
 892
 893static struct dmi_system_id i8k_dmi_table[] __initdata = {
 894        {
 895                .ident = "Dell Inspiron",
 896                .matches = {
 897                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 898                        DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 899                },
 900        },
 901        {
 902                .ident = "Dell Latitude",
 903                .matches = {
 904                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 905                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 906                },
 907        },
 908        {
 909                .ident = "Dell Inspiron 2",
 910                .matches = {
 911                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 912                        DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 913                },
 914        },
 915        {
 916                .ident = "Dell Latitude D520",
 917                .matches = {
 918                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 919                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
 920                },
 921                .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
 922        },
 923        {
 924                .ident = "Dell Latitude 2",
 925                .matches = {
 926                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 927                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 928                },
 929        },
 930        {       /* UK Inspiron 6400  */
 931                .ident = "Dell Inspiron 3",
 932                .matches = {
 933                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 934                        DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
 935                },
 936        },
 937        {
 938                .ident = "Dell Inspiron 3",
 939                .matches = {
 940                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 941                        DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
 942                },
 943        },
 944        {
 945                .ident = "Dell Precision 490",
 946                .matches = {
 947                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 948                        DMI_MATCH(DMI_PRODUCT_NAME,
 949                                  "Precision WorkStation 490"),
 950                },
 951                .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
 952        },
 953        {
 954                .ident = "Dell Precision",
 955                .matches = {
 956                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 957                        DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
 958                },
 959        },
 960        {
 961                .ident = "Dell Vostro",
 962                .matches = {
 963                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 964                        DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
 965                },
 966        },
 967        {
 968                .ident = "Dell XPS421",
 969                .matches = {
 970                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 971                        DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
 972                },
 973        },
 974        {
 975                .ident = "Dell Studio",
 976                .matches = {
 977                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 978                        DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
 979                },
 980                .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
 981        },
 982        {
 983                .ident = "Dell XPS 13",
 984                .matches = {
 985                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 986                        DMI_MATCH(DMI_PRODUCT_NAME, "XPS13"),
 987                },
 988                .driver_data = (void *)&i8k_config_data[DELL_XPS],
 989        },
 990        {
 991                .ident = "Dell XPS M140",
 992                .matches = {
 993                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 994                        DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
 995                },
 996                .driver_data = (void *)&i8k_config_data[DELL_XPS],
 997        },
 998        {
 999                .ident = "Dell XPS 15 9560",
1000                .matches = {
1001                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1002                        DMI_MATCH(DMI_PRODUCT_NAME, "XPS 15 9560"),
1003                },
1004        },
1005        { }
1006};
1007
1008MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1009
1010/*
1011 * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1012 * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1013 * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1014 * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1015 */
1016static struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initdata = {
1017        {
1018                .ident = "Dell Studio XPS 8000",
1019                .matches = {
1020                        DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1021                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1022                },
1023        },
1024        {
1025                .ident = "Dell Studio XPS 8100",
1026                .matches = {
1027                        DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1028                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1029                },
1030        },
1031        {
1032                .ident = "Dell Inspiron 580",
1033                .matches = {
1034                        DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1035                        DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1036                },
1037        },
1038        { }
1039};
1040
1041/*
1042 * Probe for the presence of a supported laptop.
1043 */
1044static int __init i8k_probe(void)
1045{
1046        const struct dmi_system_id *id;
1047        int fan, ret;
1048
1049        /*
1050         * Get DMI information
1051         */
1052        if (!dmi_check_system(i8k_dmi_table)) {
1053                if (!ignore_dmi && !force)
1054                        return -ENODEV;
1055
1056                pr_info("not running on a supported Dell system.\n");
1057                pr_info("vendor=%s, model=%s, version=%s\n",
1058                        i8k_get_dmi_data(DMI_SYS_VENDOR),
1059                        i8k_get_dmi_data(DMI_PRODUCT_NAME),
1060                        i8k_get_dmi_data(DMI_BIOS_VERSION));
1061        }
1062
1063        if (dmi_check_system(i8k_blacklist_fan_type_dmi_table))
1064                disallow_fan_type_call = true;
1065
1066        strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1067                sizeof(bios_version));
1068        strlcpy(bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1069                sizeof(bios_machineid));
1070
1071        /*
1072         * Get SMM Dell signature
1073         */
1074        if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1075            i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1076                pr_err("unable to get SMM Dell signature\n");
1077                if (!force)
1078                        return -ENODEV;
1079        }
1080
1081        /*
1082         * Set fan multiplier and maximal fan speed from dmi config
1083         * Values specified in module parameters override values from dmi
1084         */
1085        id = dmi_first_match(i8k_dmi_table);
1086        if (id && id->driver_data) {
1087                const struct i8k_config_data *conf = id->driver_data;
1088                if (!fan_mult && conf->fan_mult)
1089                        fan_mult = conf->fan_mult;
1090                if (!fan_max && conf->fan_max)
1091                        fan_max = conf->fan_max;
1092        }
1093
1094        i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
1095        i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);
1096
1097        if (!fan_mult) {
1098                /*
1099                 * Autodetect fan multiplier based on nominal rpm
1100                 * If fan reports rpm value too high then set multiplier to 1
1101                 */
1102                for (fan = 0; fan < 2; ++fan) {
1103                        ret = i8k_get_fan_nominal_speed(fan, i8k_fan_max);
1104                        if (ret < 0)
1105                                continue;
1106                        if (ret > I8K_FAN_MAX_RPM)
1107                                i8k_fan_mult = 1;
1108                        break;
1109                }
1110        } else {
1111                /* Fan multiplier was specified in module param or in dmi */
1112                i8k_fan_mult = fan_mult;
1113        }
1114
1115        return 0;
1116}
1117
1118static int __init i8k_init(void)
1119{
1120        int err;
1121
1122        /* Are we running on an supported laptop? */
1123        if (i8k_probe())
1124                return -ENODEV;
1125
1126        err = i8k_init_hwmon();
1127        if (err)
1128                return err;
1129
1130        i8k_init_procfs();
1131        return 0;
1132}
1133
1134static void __exit i8k_exit(void)
1135{
1136        hwmon_device_unregister(i8k_hwmon_dev);
1137        i8k_exit_procfs();
1138}
1139
1140module_init(i8k_init);
1141module_exit(i8k_exit);
1142