drivers/hwmon/dell-smm-hwmon.c

   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@kernel.org>
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/cpu.h>
  16 #include <linux/delay.h>
  17 #include <linux/err.h>
  18 #include <linux/module.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/types.h>
  21 #include <linux/init.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/dmi.h>
  25 #include <linux/capability.h>
  26 #include <linux/mutex.h>
  27 #include <linux/hwmon.h>
  28 #include <linux/uaccess.h>
  29 #include <linux/io.h>
  30 #include <linux/sched.h>
  31 #include <linux/ctype.h>
  32 #include <linux/smp.h>
  33
  34 #include <linux/i8k.h>
  35
  36 #define I8K_SMM_FN_STATUS       0x0025
  37 #define I8K_SMM_POWER_STATUS    0x0069
  38 #define I8K_SMM_SET_FAN         0x01a3
  39 #define I8K_SMM_GET_FAN         0x00a3
  40 #define I8K_SMM_GET_SPEED       0x02a3
  41 #define I8K_SMM_GET_FAN_TYPE    0x03a3
  42 #define I8K_SMM_GET_NOM_SPEED   0x04a3
  43 #define I8K_SMM_GET_TEMP        0x10a3
  44 #define I8K_SMM_GET_TEMP_TYPE   0x11a3
  45 #define I8K_SMM_GET_DELL_SIG1   0xfea3
  46 #define I8K_SMM_GET_DELL_SIG2   0xffa3
  47
  48 #define I8K_FAN_MULT            30
  49 #define I8K_FAN_MAX_RPM         30000
  50 #define I8K_MAX_TEMP            127
  51
  52 #define I8K_FN_NONE             0x00
  53 #define I8K_FN_UP               0x01
  54 #define I8K_FN_DOWN             0x02
  55 #define I8K_FN_MUTE             0x04
  56 #define I8K_FN_MASK             0x07
  57 #define I8K_FN_SHIFT            8
  58
  59 #define I8K_POWER_AC            0x05
  60 #define I8K_POWER_BATTERY       0x01
  61
  62 #define DELL_SMM_NO_TEMP        10
  63 #define DELL_SMM_NO_FANS        3
  64
  65 struct dell_smm_data {
  66         struct mutex i8k_mutex; /* lock for sensors writes */
  67         char bios_version[4];
  68         char bios_machineid[16];
  69         uint i8k_fan_mult;
  70         uint i8k_pwm_mult;
  71         uint i8k_fan_max;
  72         bool disallow_fan_type_call;
  73         bool disallow_fan_support;
  74         unsigned int manual_fan;
  75         unsigned int auto_fan;
  76         int temp_type[DELL_SMM_NO_TEMP];
  77         bool fan[DELL_SMM_NO_FANS];
  78         int fan_type[DELL_SMM_NO_FANS];
  79 };
  80
  81 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
  82 MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
  83 MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
  84 MODULE_LICENSE("GPL");
  85 MODULE_ALIAS("i8k");
  86
  87 static bool force;
  88 module_param(force, bool, 0);
  89 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
  90
  91 static bool ignore_dmi;
  92 module_param(ignore_dmi, bool, 0);
  93 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
  94
  95 #if IS_ENABLED(CONFIG_I8K)
  96 static bool restricted = true;
  97 module_param(restricted, bool, 0);
  98 MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
  99
 100 static bool power_status;
 101 module_param(power_status, bool, 0600);
 102 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
 103 #endif
 104
 105 static uint fan_mult;
 106 module_param(fan_mult, uint, 0);
 107 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
 108
 109 static uint fan_max;
 110 module_param(fan_max, uint, 0);
 111 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
 112
 113 struct smm_regs {
 114         unsigned int eax;
 115         unsigned int ebx __packed;
 116         unsigned int ecx __packed;
 117         unsigned int edx __packed;
 118         unsigned int esi __packed;
 119         unsigned int edi __packed;
 120 };
 121
 122 static const char * const temp_labels[] = {
 123         "CPU",
 124         "GPU",
 125         "SODIMM",
 126         "Other",
 127         "Ambient",
 128         "Other",
 129 };
 130
 131 static const char * const fan_labels[] = {
 132         "Processor Fan",
 133         "Motherboard Fan",
 134         "Video Fan",
 135         "Power Supply Fan",
 136         "Chipset Fan",
 137         "Other Fan",
 138 };
 139
 140 static const char * const docking_labels[] = {
 141         "Docking Processor Fan",
 142         "Docking Motherboard Fan",
 143         "Docking Video Fan",
 144         "Docking Power Supply Fan",
 145         "Docking Chipset Fan",
 146         "Docking Other Fan",
 147 };
 148
 149 static inline const char __init *i8k_get_dmi_data(int field)
 150 {
 151         const char *dmi_data = dmi_get_system_info(field);
 152
 153         return dmi_data && *dmi_data ? dmi_data : "?";
 154 }
 155
 156 /*
 157  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
 158  */
 159 static int i8k_smm_func(void *par)
 160 {
 161         ktime_t calltime = ktime_get();
 162         struct smm_regs *regs = par;
 163         int eax = regs->eax;
 164         int ebx = regs->ebx;
 165         long long duration;
 166         int rc;
 167
 168         /* SMM requires CPU 0 */
 169         if (smp_processor_id() != 0)
 170                 return -EBUSY;
 171
 172 #if defined(CONFIG_X86_64)
 173         asm volatile("pushq %%rax\n\t"
 174                 "movl 0(%%rax),%%edx\n\t"
 175                 "pushq %%rdx\n\t"
 176                 "movl 4(%%rax),%%ebx\n\t"
 177                 "movl 8(%%rax),%%ecx\n\t"
 178                 "movl 12(%%rax),%%edx\n\t"
 179                 "movl 16(%%rax),%%esi\n\t"
 180                 "movl 20(%%rax),%%edi\n\t"
 181                 "popq %%rax\n\t"
 182                 "out %%al,$0xb2\n\t"
 183                 "out %%al,$0x84\n\t"
 184                 "xchgq %%rax,(%%rsp)\n\t"
 185                 "movl %%ebx,4(%%rax)\n\t"
 186                 "movl %%ecx,8(%%rax)\n\t"
 187                 "movl %%edx,12(%%rax)\n\t"
 188                 "movl %%esi,16(%%rax)\n\t"
 189                 "movl %%edi,20(%%rax)\n\t"
 190                 "popq %%rdx\n\t"
 191                 "movl %%edx,0(%%rax)\n\t"
 192                 "pushfq\n\t"
 193                 "popq %%rax\n\t"
 194                 "andl $1,%%eax\n"
 195                 : "=a"(rc)
 196                 :    "a"(regs)
 197                 :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 198 #else
 199         asm volatile("pushl %%eax\n\t"
 200             "movl 0(%%eax),%%edx\n\t"
 201             "push %%edx\n\t"
 202             "movl 4(%%eax),%%ebx\n\t"
 203             "movl 8(%%eax),%%ecx\n\t"
 204             "movl 12(%%eax),%%edx\n\t"
 205             "movl 16(%%eax),%%esi\n\t"
 206             "movl 20(%%eax),%%edi\n\t"
 207             "popl %%eax\n\t"
 208             "out %%al,$0xb2\n\t"
 209             "out %%al,$0x84\n\t"
 210             "xchgl %%eax,(%%esp)\n\t"
 211             "movl %%ebx,4(%%eax)\n\t"
 212             "movl %%ecx,8(%%eax)\n\t"
 213             "movl %%edx,12(%%eax)\n\t"
 214             "movl %%esi,16(%%eax)\n\t"
 215             "movl %%edi,20(%%eax)\n\t"
 216             "popl %%edx\n\t"
 217             "movl %%edx,0(%%eax)\n\t"
 218             "lahf\n\t"
 219             "shrl $8,%%eax\n\t"
 220             "andl $1,%%eax\n"
 221             : "=a"(rc)
 222             :    "a"(regs)
 223             :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
 224 #endif
 225         if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
 226                 rc = -EINVAL;
 227
 228         duration = ktime_us_delta(ktime_get(), calltime);
 229         pr_debug("smm(0x%.4x 0x%.4x) = 0x%.4x  (took %7lld usecs)\n", eax, ebx,
 230                  (rc ? 0xffff : regs->eax & 0xffff), duration);
 231
 232         return rc;
 233 }
 234
 235 /*
 236  * Call the System Management Mode BIOS.
 237  */
 238 static int i8k_smm(struct smm_regs *regs)
 239 {
 240         int ret;
 241
 242         cpus_read_lock();
 243         ret = smp_call_on_cpu(0, i8k_smm_func, regs, true);
 244         cpus_read_unlock();
 245
 246         return ret;
 247 }
 248
 249 /*
 250  * Read the fan status.
 251  */
 252 static int i8k_get_fan_status(const struct dell_smm_data *data, int fan)
 253 {
 254         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
 255
 256         if (data->disallow_fan_support)
 257                 return -EINVAL;
 258
 259         regs.ebx = fan & 0xff;
 260         return i8k_smm(&regs) ? : regs.eax & 0xff;
 261 }
 262
 263 /*
 264  * Read the fan speed in RPM.
 265  */
 266 static int i8k_get_fan_speed(const struct dell_smm_data *data, int fan)
 267 {
 268         struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
 269
 270         if (data->disallow_fan_support)
 271                 return -EINVAL;
 272
 273         regs.ebx = fan & 0xff;
 274         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
 275 }
 276
 277 /*
 278  * Read the fan type.
 279  */
 280 static int _i8k_get_fan_type(const struct dell_smm_data *data, int fan)
 281 {
 282         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN_TYPE, };
 283
 284         if (data->disallow_fan_support || data->disallow_fan_type_call)
 285                 return -EINVAL;
 286
 287         regs.ebx = fan & 0xff;
 288         return i8k_smm(&regs) ? : regs.eax & 0xff;
 289 }
 290
 291 static int i8k_get_fan_type(struct dell_smm_data *data, int fan)
 292 {
 293         /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
 294         if (data->fan_type[fan] == INT_MIN)
 295                 data->fan_type[fan] = _i8k_get_fan_type(data, fan);
 296
 297         return data->fan_type[fan];
 298 }
 299
 300 /*
 301  * Read the fan nominal rpm for specific fan speed.
 302  */
 303 static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, int fan, int speed)
 304 {
 305         struct smm_regs regs = { .eax = I8K_SMM_GET_NOM_SPEED, };
 306
 307         if (data->disallow_fan_support)
 308                 return -EINVAL;
 309
 310         regs.ebx = (fan & 0xff) | (speed << 8);
 311         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
 312 }
 313
 314 /*
 315  * Enable or disable automatic BIOS fan control support
 316  */
 317 static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enable)
 318 {
 319         struct smm_regs regs = { };
 320
 321         if (data->disallow_fan_support)
 322                 return -EINVAL;
 323
 324         regs.eax = enable ? data->auto_fan : data->manual_fan;
 325         return i8k_smm(&regs);
 326 }
 327
 328 /*
 329  * Set the fan speed (off, low, high). Returns the new fan status.
 330  */
 331 static int i8k_set_fan(const struct dell_smm_data *data, int fan, int speed)
 332 {
 333         struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
 334
 335         if (data->disallow_fan_support)
 336                 return -EINVAL;
 337
 338         speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);
 339         regs.ebx = (fan & 0xff) | (speed << 8);
 340
 341         return i8k_smm(&regs) ? : i8k_get_fan_status(data, fan);
 342 }
 343
 344 static int __init i8k_get_temp_type(int sensor)
 345 {
 346         struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP_TYPE, };
 347
 348         regs.ebx = sensor & 0xff;
 349         return i8k_smm(&regs) ? : regs.eax & 0xff;
 350 }
 351
 352 /*
 353  * Read the cpu temperature.
 354  */
 355 static int _i8k_get_temp(int sensor)
 356 {
 357         struct smm_regs regs = {
 358                 .eax = I8K_SMM_GET_TEMP,
 359                 .ebx = sensor & 0xff,
 360         };
 361
 362         return i8k_smm(&regs) ? : regs.eax & 0xff;
 363 }
 364
 365 static int i8k_get_temp(int sensor)
 366 {
 367         int temp = _i8k_get_temp(sensor);
 368
 369         /*
 370          * Sometimes the temperature sensor returns 0x99, which is out of range.
 371          * In this case we retry (once) before returning an error.
 372          # 1003655137 00000058 00005a4b
 373          # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 374          # 1003655139 00000054 00005c52
 375          */
 376         if (temp == 0x99) {
 377                 msleep(100);
 378                 temp = _i8k_get_temp(sensor);
 379         }
 380         /*
 381          * Return -ENODATA for all invalid temperatures.
 382          *
 383          * Known instances are the 0x99 value as seen above as well as
 384          * 0xc1 (193), which may be returned when trying to read the GPU
 385          * temperature if the system supports a GPU and it is currently
 386          * turned off.
 387          */
 388         if (temp > I8K_MAX_TEMP)
 389                 return -ENODATA;
 390
 391         return temp;
 392 }
 393
 394 static int __init i8k_get_dell_signature(int req_fn)
 395 {
 396         struct smm_regs regs = { .eax = req_fn, };
 397         int rc;
 398
 399         rc = i8k_smm(&regs);
 400         if (rc < 0)
 401                 return rc;
 402
 403         return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 404 }
 405
 406 #if IS_ENABLED(CONFIG_I8K)
 407
 408 /*
 409  * Read the Fn key status.
 410  */
 411 static int i8k_get_fn_status(void)
 412 {
 413         struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
 414         int rc;
 415
 416         rc = i8k_smm(&regs);
 417         if (rc < 0)
 418                 return rc;
 419
 420         switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 421         case I8K_FN_UP:
 422                 return I8K_VOL_UP;
 423         case I8K_FN_DOWN:
 424                 return I8K_VOL_DOWN;
 425         case I8K_FN_MUTE:
 426                 return I8K_VOL_MUTE;
 427         default:
 428                 return 0;
 429         }
 430 }
 431
 432 /*
 433  * Read the power status.
 434  */
 435 static int i8k_get_power_status(void)
 436 {
 437         struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
 438         int rc;
 439
 440         rc = i8k_smm(&regs);
 441         if (rc < 0)
 442                 return rc;
 443
 444         return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
 445 }
 446
 447 /*
 448  * Procfs interface
 449  */
 450
 451 static int
 452 i8k_ioctl_unlocked(struct file *fp, struct dell_smm_data *data, unsigned int cmd, unsigned long arg)
 453 {
 454         int val = 0;
 455         int speed;
 456         unsigned char buff[16];
 457         int __user *argp = (int __user *)arg;
 458
 459         if (!argp)
 460                 return -EINVAL;
 461
 462         switch (cmd) {
 463         case I8K_BIOS_VERSION:
 464                 if (!isdigit(data->bios_version[0]) || !isdigit(data->bios_version[1]) ||
 465                     !isdigit(data->bios_version[2]))
 466                         return -EINVAL;
 467
 468                 val = (data->bios_version[0] << 16) |
 469                                 (data->bios_version[1] << 8) | data->bios_version[2];
 470                 break;
 471
 472         case I8K_MACHINE_ID:
 473                 if (restricted && !capable(CAP_SYS_ADMIN))
 474                         return -EPERM;
 475
 476                 memset(buff, 0, sizeof(buff));
 477                 strscpy(buff, data->bios_machineid, sizeof(buff));
 478                 break;
 479
 480         case I8K_FN_STATUS:
 481                 val = i8k_get_fn_status();
 482                 break;
 483
 484         case I8K_POWER_STATUS:
 485                 val = i8k_get_power_status();
 486                 break;
 487
 488         case I8K_GET_TEMP:
 489                 val = i8k_get_temp(0);
 490                 break;
 491
 492         case I8K_GET_SPEED:
 493                 if (copy_from_user(&val, argp, sizeof(int)))
 494                         return -EFAULT;
 495
 496                 val = i8k_get_fan_speed(data, val);
 497                 break;
 498
 499         case I8K_GET_FAN:
 500                 if (copy_from_user(&val, argp, sizeof(int)))
 501                         return -EFAULT;
 502
 503                 val = i8k_get_fan_status(data, val);
 504                 break;
 505
 506         case I8K_SET_FAN:
 507                 if (restricted && !capable(CAP_SYS_ADMIN))
 508                         return -EPERM;
 509
 510                 if (copy_from_user(&val, argp, sizeof(int)))
 511                         return -EFAULT;
 512
 513                 if (copy_from_user(&speed, argp + 1, sizeof(int)))
 514                         return -EFAULT;
 515
 516                 val = i8k_set_fan(data, val, speed);
 517                 break;
 518
 519         default:
 520                 return -EINVAL;
 521         }
 522
 523         if (val < 0)
 524                 return val;
 525
 526         switch (cmd) {
 527         case I8K_BIOS_VERSION:
 528                 if (copy_to_user(argp, &val, 4))
 529                         return -EFAULT;
 530
 531                 break;
 532         case I8K_MACHINE_ID:
 533                 if (copy_to_user(argp, buff, 16))
 534                         return -EFAULT;
 535
 536                 break;
 537         default:
 538                 if (copy_to_user(argp, &val, sizeof(int)))
 539                         return -EFAULT;
 540
 541                 break;
 542         }
 543
 544         return 0;
 545 }
 546
 547 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 548 {
 549         struct dell_smm_data *data = PDE_DATA(file_inode(fp));
 550         long ret;
 551
 552         mutex_lock(&data->i8k_mutex);
 553         ret = i8k_ioctl_unlocked(fp, data, cmd, arg);
 554         mutex_unlock(&data->i8k_mutex);
 555
 556         return ret;
 557 }
 558
 559 /*
 560  * Print the information for /proc/i8k.
 561  */
 562 static int i8k_proc_show(struct seq_file *seq, void *offset)
 563 {
 564         struct dell_smm_data *data = seq->private;
 565         int fn_key, cpu_temp, ac_power;
 566         int left_fan, right_fan, left_speed, right_speed;
 567
 568         cpu_temp        = i8k_get_temp(0);                              /* 11100 µs */
 569         left_fan        = i8k_get_fan_status(data, I8K_FAN_LEFT);       /*   580 µs */
 570         right_fan       = i8k_get_fan_status(data, I8K_FAN_RIGHT);      /*   580 µs */
 571         left_speed      = i8k_get_fan_speed(data, I8K_FAN_LEFT);        /*   580 µs */
 572         right_speed     = i8k_get_fan_speed(data, I8K_FAN_RIGHT);       /*   580 µs */
 573         fn_key          = i8k_get_fn_status();                          /*   750 µs */
 574         if (power_status)
 575                 ac_power = i8k_get_power_status();                      /* 14700 µs */
 576         else
 577                 ac_power = -1;
 578
 579         /*
 580          * Info:
 581          *
 582          * 1)  Format version (this will change if format changes)
 583          * 2)  BIOS version
 584          * 3)  BIOS machine ID
 585          * 4)  Cpu temperature
 586          * 5)  Left fan status
 587          * 6)  Right fan status
 588          * 7)  Left fan speed
 589          * 8)  Right fan speed
 590          * 9)  AC power
 591          * 10) Fn Key status
 592          */
 593         seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
 594                    I8K_PROC_FMT,
 595                    data->bios_version,
 596                    (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : data->bios_machineid,
 597                    cpu_temp,
 598                    left_fan, right_fan, left_speed, right_speed,
 599                    ac_power, fn_key);
 600
 601         return 0;
 602 }
 603
 604 static int i8k_open_fs(struct inode *inode, struct file *file)
 605 {
 606         return single_open(file, i8k_proc_show, PDE_DATA(inode));
 607 }
 608
 609 static const struct proc_ops i8k_proc_ops = {
 610         .proc_open      = i8k_open_fs,
 611         .proc_read      = seq_read,
 612         .proc_lseek     = seq_lseek,
 613         .proc_release   = single_release,
 614         .proc_ioctl     = i8k_ioctl,
 615 };
 616
 617 static void i8k_exit_procfs(void *param)
 618 {
 619         remove_proc_entry("i8k", NULL);
 620 }
 621
 622 static void __init i8k_init_procfs(struct device *dev)
 623 {
 624         struct dell_smm_data *data = dev_get_drvdata(dev);
 625
 626         /* Register the proc entry */
 627         proc_create_data("i8k", 0, NULL, &i8k_proc_ops, data);
 628
 629         devm_add_action_or_reset(dev, i8k_exit_procfs, NULL);
 630 }
 631
 632 #else
 633
 634 static void __init i8k_init_procfs(struct device *dev)
 635 {
 636 }
 637
 638 #endif
 639
 640 /*
 641  * Hwmon interface
 642  */
 643
 644 static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
 645                                    int channel)
 646 {
 647         const struct dell_smm_data *data = drvdata;
 648
 649         switch (type) {
 650         case hwmon_temp:
 651                 switch (attr) {
 652                 case hwmon_temp_input:
 653                 case hwmon_temp_label:
 654                         if (data->temp_type[channel] >= 0)
 655                                 return 0444;
 656
 657                         break;
 658                 default:
 659                         break;
 660                 }
 661                 break;
 662         case hwmon_fan:
 663                 if (data->disallow_fan_support)
 664                         break;
 665
 666                 switch (attr) {
 667                 case hwmon_fan_input:
 668                         if (data->fan[channel])
 669                                 return 0444;
 670
 671                         break;
 672                 case hwmon_fan_label:
 673                         if (data->fan[channel] && !data->disallow_fan_type_call)
 674                                 return 0444;
 675
 676                         break;
 677                 default:
 678                         break;
 679                 }
 680                 break;
 681         case hwmon_pwm:
 682                 if (data->disallow_fan_support)
 683                         break;
 684
 685                 switch (attr) {
 686                 case hwmon_pwm_input:
 687                         if (data->fan[channel])
 688                                 return 0644;
 689
 690                         break;
 691                 case hwmon_pwm_enable:
 692                         if (data->auto_fan)
 693                                 /*
 694                                  * There is no command for retrieve the current status
 695                                  * from BIOS, and userspace/firmware itself can change
 696                                  * it.
 697                                  * Thus we can only provide write-only access for now.
 698                                  */
 699                                 return 0200;
 700
 701                         break;
 702                 default:
 703                         break;
 704                 }
 705                 break;
 706         default:
 707                 break;
 708         }
 709
 710         return 0;
 711 }
 712
 713 static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
 714                          long *val)
 715 {
 716         struct dell_smm_data *data = dev_get_drvdata(dev);
 717         int ret;
 718
 719         switch (type) {
 720         case hwmon_temp:
 721                 switch (attr) {
 722                 case hwmon_temp_input:
 723                         ret = i8k_get_temp(channel);
 724                         if (ret < 0)
 725                                 return ret;
 726
 727                         *val = ret * 1000;
 728
 729                         return 0;
 730                 default:
 731                         break;
 732                 }
 733                 break;
 734         case hwmon_fan:
 735                 switch (attr) {
 736                 case hwmon_fan_input:
 737                         ret = i8k_get_fan_speed(data, channel);
 738                         if (ret < 0)
 739                                 return ret;
 740
 741                         *val = ret;
 742
 743                         return 0;
 744                 default:
 745                         break;
 746                 }
 747                 break;
 748         case hwmon_pwm:
 749                 switch (attr) {
 750                 case hwmon_pwm_input:
 751                         ret = i8k_get_fan_status(data, channel);
 752                         if (ret < 0)
 753                                 return ret;
 754
 755                         *val = clamp_val(ret * data->i8k_pwm_mult, 0, 255);
 756
 757                         return 0;
 758                 default:
 759                         break;
 760                 }
 761                 break;
 762         default:
 763                 break;
 764         }
 765
 766         return -EOPNOTSUPP;
 767 }
 768
 769 static const char *dell_smm_fan_label(struct dell_smm_data *data, int channel)
 770 {
 771         bool dock = false;
 772         int type = i8k_get_fan_type(data, channel);
 773
 774         if (type < 0)
 775                 return ERR_PTR(type);
 776
 777         if (type & 0x10) {
 778                 dock = true;
 779                 type &= 0x0F;
 780         }
 781
 782         if (type >= ARRAY_SIZE(fan_labels))
 783                 type = ARRAY_SIZE(fan_labels) - 1;
 784
 785         return dock ? docking_labels[type] : fan_labels[type];
 786 }
 787
 788 static int dell_smm_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 789                                 int channel, const char **str)
 790 {
 791         struct dell_smm_data *data = dev_get_drvdata(dev);
 792
 793         switch (type) {
 794         case hwmon_temp:
 795                 switch (attr) {
 796                 case hwmon_temp_label:
 797                         *str = temp_labels[data->temp_type[channel]];
 798                         return 0;
 799                 default:
 800                         break;
 801                 }
 802                 break;
 803         case hwmon_fan:
 804                 switch (attr) {
 805                 case hwmon_fan_label:
 806                         *str = dell_smm_fan_label(data, channel);
 807                         return PTR_ERR_OR_ZERO(*str);
 808                 default:
 809                         break;
 810                 }
 811                 break;
 812         default:
 813                 break;
 814         }
 815
 816         return -EOPNOTSUPP;
 817 }
 818
 819 static int dell_smm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
 820                           long val)
 821 {
 822         struct dell_smm_data *data = dev_get_drvdata(dev);
 823         unsigned long pwm;
 824         bool enable;
 825         int err;
 826
 827         switch (type) {
 828         case hwmon_pwm:
 829                 switch (attr) {
 830                 case hwmon_pwm_input:
 831                         pwm = clamp_val(DIV_ROUND_CLOSEST(val, data->i8k_pwm_mult), 0,
 832                                         data->i8k_fan_max);
 833
 834                         mutex_lock(&data->i8k_mutex);
 835                         err = i8k_set_fan(data, channel, pwm);
 836                         mutex_unlock(&data->i8k_mutex);
 837
 838                         if (err < 0)
 839                                 return err;
 840
 841                         return 0;
 842                 case hwmon_pwm_enable:
 843                         if (!val)
 844                                 return -EINVAL;
 845
 846                         if (val == 1)
 847                                 enable = false;
 848                         else
 849                                 enable = true;
 850
 851                         mutex_lock(&data->i8k_mutex);
 852                         err = i8k_enable_fan_auto_mode(data, enable);
 853                         mutex_unlock(&data->i8k_mutex);
 854
 855                         if (err < 0)
 856                                 return err;
 857
 858                         return 0;
 859                 default:
 860                         break;
 861                 }
 862                 break;
 863         default:
 864                 break;
 865         }
 866
 867         return -EOPNOTSUPP;
 868 }
 869
 870 static const struct hwmon_ops dell_smm_ops = {
 871         .is_visible = dell_smm_is_visible,
 872         .read = dell_smm_read,
 873         .read_string = dell_smm_read_string,
 874         .write = dell_smm_write,
 875 };
 876
 877 static const struct hwmon_channel_info *dell_smm_info[] = {
 878         HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
 879         HWMON_CHANNEL_INFO(temp,
 880                            HWMON_T_INPUT | HWMON_T_LABEL,
 881                            HWMON_T_INPUT | HWMON_T_LABEL,
 882                            HWMON_T_INPUT | HWMON_T_LABEL,
 883                            HWMON_T_INPUT | HWMON_T_LABEL,
 884                            HWMON_T_INPUT | HWMON_T_LABEL,
 885                            HWMON_T_INPUT | HWMON_T_LABEL,
 886                            HWMON_T_INPUT | HWMON_T_LABEL,
 887                            HWMON_T_INPUT | HWMON_T_LABEL,
 888                            HWMON_T_INPUT | HWMON_T_LABEL,
 889                            HWMON_T_INPUT | HWMON_T_LABEL
 890                            ),
 891         HWMON_CHANNEL_INFO(fan,
 892                            HWMON_F_INPUT | HWMON_F_LABEL,
 893                            HWMON_F_INPUT | HWMON_F_LABEL,
 894                            HWMON_F_INPUT | HWMON_F_LABEL
 895                            ),
 896         HWMON_CHANNEL_INFO(pwm,
 897                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
 898                            HWMON_PWM_INPUT,
 899                            HWMON_PWM_INPUT
 900                            ),
 901         NULL
 902 };
 903
 904 static const struct hwmon_chip_info dell_smm_chip_info = {
 905         .ops = &dell_smm_ops,
 906         .info = dell_smm_info,
 907 };
 908
 909 static int __init dell_smm_init_hwmon(struct device *dev)
 910 {
 911         struct dell_smm_data *data = dev_get_drvdata(dev);
 912         struct device *dell_smm_hwmon_dev;
 913         int i, err;
 914
 915         for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
 916                 data->temp_type[i] = i8k_get_temp_type(i);
 917                 if (data->temp_type[i] < 0)
 918                         continue;
 919
 920                 if (data->temp_type[i] >= ARRAY_SIZE(temp_labels))
 921                         data->temp_type[i] = ARRAY_SIZE(temp_labels) - 1;
 922         }
 923
 924         for (i = 0; i < DELL_SMM_NO_FANS; i++) {
 925                 data->fan_type[i] = INT_MIN;
 926                 err = i8k_get_fan_status(data, i);
 927                 if (err < 0)
 928                         err = i8k_get_fan_type(data, i);
 929                 if (err >= 0)
 930                         data->fan[i] = true;
 931         }
 932
 933         dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
 934                                                                   &dell_smm_chip_info, NULL);
 935
 936         return PTR_ERR_OR_ZERO(dell_smm_hwmon_dev);
 937 }
 938
 939 struct i8k_config_data {
 940         uint fan_mult;
 941         uint fan_max;
 942 };
 943
 944 enum i8k_configs {
 945         DELL_LATITUDE_D520,
 946         DELL_PRECISION_490,
 947         DELL_STUDIO,
 948         DELL_XPS,
 949 };
 950
 951 static const struct i8k_config_data i8k_config_data[] __initconst = {
 952         [DELL_LATITUDE_D520] = {
 953                 .fan_mult = 1,
 954                 .fan_max = I8K_FAN_TURBO,
 955         },
 956         [DELL_PRECISION_490] = {
 957                 .fan_mult = 1,
 958                 .fan_max = I8K_FAN_TURBO,
 959         },
 960         [DELL_STUDIO] = {
 961                 .fan_mult = 1,
 962                 .fan_max = I8K_FAN_HIGH,
 963         },
 964         [DELL_XPS] = {
 965                 .fan_mult = 1,
 966                 .fan_max = I8K_FAN_HIGH,
 967         },
 968 };
 969
 970 static const struct dmi_system_id i8k_dmi_table[] __initconst = {
 971         {
 972                 .ident = "Dell Inspiron",
 973                 .matches = {
 974                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 975                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 976                 },
 977         },
 978         {
 979                 .ident = "Dell Latitude",
 980                 .matches = {
 981                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
 982                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
 983                 },
 984         },
 985         {
 986                 .ident = "Dell Inspiron 2",
 987                 .matches = {
 988                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 989                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
 990                 },
 991         },
 992         {
 993                 .ident = "Dell Latitude D520",
 994                 .matches = {
 995                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 996                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
 997                 },
 998                 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
 999         },
1000         {
1001                 .ident = "Dell Latitude 2",
1002                 .matches = {
1003                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1004                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1005                 },
1006         },
1007         {       /* UK Inspiron 6400  */
1008                 .ident = "Dell Inspiron 3",
1009                 .matches = {
1010                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1011                         DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1012                 },
1013         },
1014         {
1015                 .ident = "Dell Inspiron 3",
1016                 .matches = {
1017                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1018                         DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1019                 },
1020         },
1021         {
1022                 .ident = "Dell Precision 490",
1023                 .matches = {
1024                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1025                         DMI_MATCH(DMI_PRODUCT_NAME,
1026                                   "Precision WorkStation 490"),
1027                 },
1028                 .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1029         },
1030         {
1031                 .ident = "Dell Precision",
1032                 .matches = {
1033                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1034                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1035                 },
1036         },
1037         {
1038                 .ident = "Dell Vostro",
1039                 .matches = {
1040                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1041                         DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1042                 },
1043         },
1044         {
1045                 .ident = "Dell Studio",
1046                 .matches = {
1047                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1048                         DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1049                 },
1050                 .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1051         },
1052         {
1053                 .ident = "Dell XPS M140",
1054                 .matches = {
1055                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1056                         DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1057                 },
1058                 .driver_data = (void *)&i8k_config_data[DELL_XPS],
1059         },
1060         {
1061                 .ident = "Dell XPS",
1062                 .matches = {
1063                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1064                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS"),
1065                 },
1066         },
1067         { }
1068 };
1069
1070 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1071
1072 /*
1073  * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1074  * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1075  * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1076  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1077  */
1078 static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1079         {
1080                 .ident = "Dell Studio XPS 8000",
1081                 .matches = {
1082                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1083                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1084                 },
1085         },
1086         {
1087                 .ident = "Dell Studio XPS 8100",
1088                 .matches = {
1089                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1090                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1091                 },
1092         },
1093         {
1094                 .ident = "Dell Inspiron 580",
1095                 .matches = {
1096                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1097                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1098                 },
1099         },
1100         { }
1101 };
1102
1103 /*
1104  * On some machines all fan related SMM functions implemented by Dell BIOS
1105  * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1106  * support for affected blacklisted Dell machines stay disabled.
1107  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1108  */
1109 static const struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initconst = {
1110         {
1111                 .ident = "Dell Inspiron 7720",
1112                 .matches = {
1113                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1114                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1115                 },
1116         },
1117         {
1118                 .ident = "Dell Vostro 3360",
1119                 .matches = {
1120                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1121                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1122                 },
1123         },
1124         {
1125                 .ident = "Dell XPS13 9333",
1126                 .matches = {
1127                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1128                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1129                 },
1130         },
1131         {
1132                 .ident = "Dell XPS 15 L502X",
1133                 .matches = {
1134                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1135                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L502X"),
1136                 },
1137         },
1138         { }
1139 };
1140
1141 struct i8k_fan_control_data {
1142         unsigned int manual_fan;
1143         unsigned int auto_fan;
1144 };
1145
1146 enum i8k_fan_controls {
1147         I8K_FAN_34A3_35A3,
1148 };
1149
1150 static const struct i8k_fan_control_data i8k_fan_control_data[] __initconst = {
1151         [I8K_FAN_34A3_35A3] = {
1152                 .manual_fan = 0x34a3,
1153                 .auto_fan = 0x35a3,
1154         },
1155 };
1156
1157 static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
1158         {
1159                 .ident = "Dell Latitude 5480",
1160                 .matches = {
1161                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1162                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5480"),
1163                 },
1164                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1165         },
1166         {
1167                 .ident = "Dell Latitude E6440",
1168                 .matches = {
1169                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1170                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1171                 },
1172                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1173         },
1174         {
1175                 .ident = "Dell Latitude E7440",
1176                 .matches = {
1177                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1178                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E7440"),
1179                 },
1180                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1181         },
1182         {
1183                 .ident = "Dell Precision 5530",
1184                 .matches = {
1185                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1186                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1187                 },
1188                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1189         },
1190         {
1191                 .ident = "Dell Precision 7510",
1192                 .matches = {
1193                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1194                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
1195                 },
1196                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1197         },
1198         { }
1199 };
1200
1201 static int __init dell_smm_probe(struct platform_device *pdev)
1202 {
1203         struct dell_smm_data *data;
1204         const struct dmi_system_id *id, *fan_control;
1205         int fan, ret;
1206
1207         data = devm_kzalloc(&pdev->dev, sizeof(struct dell_smm_data), GFP_KERNEL);
1208         if (!data)
1209                 return -ENOMEM;
1210
1211         mutex_init(&data->i8k_mutex);
1212         data->i8k_fan_mult = I8K_FAN_MULT;
1213         data->i8k_fan_max = I8K_FAN_HIGH;
1214         platform_set_drvdata(pdev, data);
1215
1216         if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
1217                 dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan support\n");
1218                 if (!force)
1219                         data->disallow_fan_support = true;
1220         }
1221
1222         if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
1223                 dev_warn(&pdev->dev, "broken Dell BIOS detected, disallow fan type call\n");
1224                 if (!force)
1225                         data->disallow_fan_type_call = true;
1226         }
1227
1228         strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1229                 sizeof(data->bios_version));
1230         strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1231                 sizeof(data->bios_machineid));
1232
1233         /*
1234          * Set fan multiplier and maximal fan speed from dmi config
1235          * Values specified in module parameters override values from dmi
1236          */
1237         id = dmi_first_match(i8k_dmi_table);
1238         if (id && id->driver_data) {
1239                 const struct i8k_config_data *conf = id->driver_data;
1240
1241                 if (!fan_mult && conf->fan_mult)
1242                         fan_mult = conf->fan_mult;
1243
1244                 if (!fan_max && conf->fan_max)
1245                         fan_max = conf->fan_max;
1246         }
1247
1248         data->i8k_fan_max = fan_max ? : I8K_FAN_HIGH;   /* Must not be 0 */
1249         data->i8k_pwm_mult = DIV_ROUND_UP(255, data->i8k_fan_max);
1250
1251         fan_control = dmi_first_match(i8k_whitelist_fan_control);
1252         if (fan_control && fan_control->driver_data) {
1253                 const struct i8k_fan_control_data *control = fan_control->driver_data;
1254
1255                 data->manual_fan = control->manual_fan;
1256                 data->auto_fan = control->auto_fan;
1257                 dev_info(&pdev->dev, "enabling support for setting automatic/manual fan control\n");
1258         }
1259
1260         if (!fan_mult) {
1261                 /*
1262                  * Autodetect fan multiplier based on nominal rpm
1263                  * If fan reports rpm value too high then set multiplier to 1
1264                  */
1265                 for (fan = 0; fan < DELL_SMM_NO_FANS; ++fan) {
1266                         ret = i8k_get_fan_nominal_speed(data, fan, data->i8k_fan_max);
1267                         if (ret < 0)
1268                                 continue;
1269
1270                         if (ret > I8K_FAN_MAX_RPM)
1271                                 data->i8k_fan_mult = 1;
1272                         break;
1273                 }
1274         } else {
1275                 /* Fan multiplier was specified in module param or in dmi */
1276                 data->i8k_fan_mult = fan_mult;
1277         }
1278
1279         ret = dell_smm_init_hwmon(&pdev->dev);
1280         if (ret)
1281                 return ret;
1282
1283         i8k_init_procfs(&pdev->dev);
1284
1285         return 0;
1286 }
1287
1288 static struct platform_driver dell_smm_driver = {
1289         .driver         = {
1290                 .name   = KBUILD_MODNAME,
1291         },
1292 };
1293
1294 static struct platform_device *dell_smm_device;
1295
1296 /*
1297  * Probe for the presence of a supported laptop.
1298  */
1299 static int __init i8k_init(void)
1300 {
1301         /*
1302          * Get DMI information
1303          */
1304         if (!dmi_check_system(i8k_dmi_table)) {
1305                 if (!ignore_dmi && !force)
1306                         return -ENODEV;
1307
1308                 pr_info("not running on a supported Dell system.\n");
1309                 pr_info("vendor=%s, model=%s, version=%s\n",
1310                         i8k_get_dmi_data(DMI_SYS_VENDOR),
1311                         i8k_get_dmi_data(DMI_PRODUCT_NAME),
1312                         i8k_get_dmi_data(DMI_BIOS_VERSION));
1313         }
1314
1315         /*
1316          * Get SMM Dell signature
1317          */
1318         if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1319             i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1320                 pr_err("unable to get SMM Dell signature\n");
1321                 if (!force)
1322                         return -ENODEV;
1323         }
1324
1325         dell_smm_device = platform_create_bundle(&dell_smm_driver, dell_smm_probe, NULL, 0, NULL,
1326                                                  0);
1327
1328         return PTR_ERR_OR_ZERO(dell_smm_device);
1329 }
1330
1331 static void __exit i8k_exit(void)
1332 {
1333         platform_device_unregister(dell_smm_device);
1334         platform_driver_unregister(&dell_smm_driver);
1335 }
1336
1337 module_init(i8k_init);
1338 module_exit(i8k_exit);