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/capability.h>
  16 #include <linux/cpu.h>
  17 #include <linux/ctype.h>
  18 #include <linux/delay.h>
  19 #include <linux/dmi.h>
  20 #include <linux/err.h>
  21 #include <linux/errno.h>
  22 #include <linux/hwmon.h>
  23 #include <linux/init.h>
  24 #include <linux/kconfig.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/mutex.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/proc_fs.h>
  30 #include <linux/seq_file.h>
  31 #include <linux/slab.h>
  32 #include <linux/smp.h>
  33 #include <linux/string.h>
  34 #include <linux/thermal.h>
  35 #include <linux/types.h>
  36 #include <linux/uaccess.h>
  37
  38 #include <linux/i8k.h>
  39
  40 #define I8K_SMM_FN_STATUS       0x0025
  41 #define I8K_SMM_POWER_STATUS    0x0069
  42 #define I8K_SMM_SET_FAN         0x01a3
  43 #define I8K_SMM_GET_FAN         0x00a3
  44 #define I8K_SMM_GET_SPEED       0x02a3
  45 #define I8K_SMM_GET_FAN_TYPE    0x03a3
  46 #define I8K_SMM_GET_NOM_SPEED   0x04a3
  47 #define I8K_SMM_GET_TEMP        0x10a3
  48 #define I8K_SMM_GET_TEMP_TYPE   0x11a3
  49 #define I8K_SMM_GET_DELL_SIG1   0xfea3
  50 #define I8K_SMM_GET_DELL_SIG2   0xffa3
  51
  52 /* in usecs */
  53 #define DELL_SMM_MAX_DURATION  250000
  54
  55 #define I8K_FAN_MULT            30
  56 #define I8K_FAN_RPM_THRESHOLD   1000
  57 #define I8K_MAX_TEMP            127
  58
  59 #define I8K_FN_NONE             0x00
  60 #define I8K_FN_UP               0x01
  61 #define I8K_FN_DOWN             0x02
  62 #define I8K_FN_MUTE             0x04
  63 #define I8K_FN_MASK             0x07
  64 #define I8K_FN_SHIFT            8
  65
  66 #define I8K_POWER_AC            0x05
  67 #define I8K_POWER_BATTERY       0x01
  68
  69 #define DELL_SMM_NO_TEMP        10
  70 #define DELL_SMM_NO_FANS        3
  71
  72 struct dell_smm_data {
  73         struct mutex i8k_mutex; /* lock for sensors writes */
  74         char bios_version[4];
  75         char bios_machineid[16];
  76         uint i8k_fan_mult;
  77         uint i8k_pwm_mult;
  78         uint i8k_fan_max;
  79         bool disallow_fan_type_call;
  80         bool disallow_fan_support;
  81         unsigned int manual_fan;
  82         unsigned int auto_fan;
  83         int temp_type[DELL_SMM_NO_TEMP];
  84         bool fan[DELL_SMM_NO_FANS];
  85         int fan_type[DELL_SMM_NO_FANS];
  86         int *fan_nominal_speed[DELL_SMM_NO_FANS];
  87 };
  88
  89 struct dell_smm_cooling_data {
  90         u8 fan_num;
  91         struct dell_smm_data *data;
  92 };
  93
  94 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
  95 MODULE_AUTHOR("Pali Rohár <pali@kernel.org>");
  96 MODULE_DESCRIPTION("Dell laptop SMM BIOS hwmon driver");
  97 MODULE_LICENSE("GPL");
  98 MODULE_ALIAS("i8k");
  99
 100 static bool force;
 101 module_param_unsafe(force, bool, 0);
 102 MODULE_PARM_DESC(force, "Force loading without checking for supported models and features");
 103
 104 static bool ignore_dmi;
 105 module_param(ignore_dmi, bool, 0);
 106 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
 107
 108 #if IS_ENABLED(CONFIG_I8K)
 109 static bool restricted = true;
 110 module_param(restricted, bool, 0);
 111 MODULE_PARM_DESC(restricted, "Restrict fan control and serial number to CAP_SYS_ADMIN (default: 1)");
 112
 113 static bool power_status;
 114 module_param(power_status, bool, 0600);
 115 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k (default: 0)");
 116 #endif
 117
 118 static uint fan_mult;
 119 module_param(fan_mult, uint, 0);
 120 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with (default: autodetect)");
 121
 122 static uint fan_max;
 123 module_param(fan_max, uint, 0);
 124 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed (default: autodetect)");
 125
 126 struct smm_regs {
 127         unsigned int eax;
 128         unsigned int ebx;
 129         unsigned int ecx;
 130         unsigned int edx;
 131         unsigned int esi;
 132         unsigned int edi;
 133 };
 134
 135 static const char * const temp_labels[] = {
 136         "CPU",
 137         "GPU",
 138         "SODIMM",
 139         "Other",
 140         "Ambient",
 141         "Other",
 142 };
 143
 144 static const char * const fan_labels[] = {
 145         "Processor Fan",
 146         "Motherboard Fan",
 147         "Video Fan",
 148         "Power Supply Fan",
 149         "Chipset Fan",
 150         "Other Fan",
 151 };
 152
 153 static const char * const docking_labels[] = {
 154         "Docking Processor Fan",
 155         "Docking Motherboard Fan",
 156         "Docking Video Fan",
 157         "Docking Power Supply Fan",
 158         "Docking Chipset Fan",
 159         "Docking Other Fan",
 160 };
 161
 162 static inline const char __init *i8k_get_dmi_data(int field)
 163 {
 164         const char *dmi_data = dmi_get_system_info(field);
 165
 166         return dmi_data && *dmi_data ? dmi_data : "?";
 167 }
 168
 169 /*
 170  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
 171  */
 172 static int i8k_smm_func(void *par)
 173 {
 174         ktime_t calltime = ktime_get();
 175         struct smm_regs *regs = par;
 176         int eax = regs->eax;
 177         int ebx = regs->ebx;
 178         unsigned char carry;
 179         long long duration;
 180
 181         /* SMM requires CPU 0 */
 182         if (smp_processor_id() != 0)
 183                 return -EBUSY;
 184
 185         asm volatile("out %%al,$0xb2\n\t"
 186                      "out %%al,$0x84\n\t"
 187                      "setc %0\n"
 188                      : "=mr" (carry),
 189                        "+a" (regs->eax),
 190                        "+b" (regs->ebx),
 191                        "+c" (regs->ecx),
 192                        "+d" (regs->edx),
 193                        "+S" (regs->esi),
 194                        "+D" (regs->edi));
 195
 196         duration = ktime_us_delta(ktime_get(), calltime);
 197         pr_debug("smm(0x%.4x 0x%.4x) = 0x%.4x carry: %d (took %7lld usecs)\n",
 198                  eax, ebx, regs->eax & 0xffff, carry, duration);
 199
 200         if (duration > DELL_SMM_MAX_DURATION)
 201                 pr_warn_once("SMM call took %lld usecs!\n", duration);
 202
 203         if (carry || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
 204                 return -EINVAL;
 205
 206         return 0;
 207 }
 208
 209 /*
 210  * Call the System Management Mode BIOS.
 211  */
 212 static int i8k_smm(struct smm_regs *regs)
 213 {
 214         int ret;
 215
 216         cpus_read_lock();
 217         ret = smp_call_on_cpu(0, i8k_smm_func, regs, true);
 218         cpus_read_unlock();
 219
 220         return ret;
 221 }
 222
 223 /*
 224  * Read the fan status.
 225  */
 226 static int i8k_get_fan_status(const struct dell_smm_data *data, u8 fan)
 227 {
 228         struct smm_regs regs = {
 229                 .eax = I8K_SMM_GET_FAN,
 230                 .ebx = fan,
 231         };
 232
 233         if (data->disallow_fan_support)
 234                 return -EINVAL;
 235
 236         return i8k_smm(&regs) ? : regs.eax & 0xff;
 237 }
 238
 239 /*
 240  * Read the fan speed in RPM.
 241  */
 242 static int i8k_get_fan_speed(const struct dell_smm_data *data, u8 fan)
 243 {
 244         struct smm_regs regs = {
 245                 .eax = I8K_SMM_GET_SPEED,
 246                 .ebx = fan,
 247         };
 248
 249         if (data->disallow_fan_support)
 250                 return -EINVAL;
 251
 252         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * data->i8k_fan_mult;
 253 }
 254
 255 /*
 256  * Read the fan type.
 257  */
 258 static int _i8k_get_fan_type(const struct dell_smm_data *data, u8 fan)
 259 {
 260         struct smm_regs regs = {
 261                 .eax = I8K_SMM_GET_FAN_TYPE,
 262                 .ebx = fan,
 263         };
 264
 265         if (data->disallow_fan_support || data->disallow_fan_type_call)
 266                 return -EINVAL;
 267
 268         return i8k_smm(&regs) ? : regs.eax & 0xff;
 269 }
 270
 271 static int i8k_get_fan_type(struct dell_smm_data *data, u8 fan)
 272 {
 273         /* I8K_SMM_GET_FAN_TYPE SMM call is expensive, so cache values */
 274         if (data->fan_type[fan] == INT_MIN)
 275                 data->fan_type[fan] = _i8k_get_fan_type(data, fan);
 276
 277         return data->fan_type[fan];
 278 }
 279
 280 /*
 281  * Read the fan nominal rpm for specific fan speed.
 282  */
 283 static int __init i8k_get_fan_nominal_speed(const struct dell_smm_data *data, u8 fan, int speed)
 284 {
 285         struct smm_regs regs = {
 286                 .eax = I8K_SMM_GET_NOM_SPEED,
 287                 .ebx = fan | (speed << 8),
 288         };
 289
 290         if (data->disallow_fan_support)
 291                 return -EINVAL;
 292
 293         return i8k_smm(&regs) ? : (regs.eax & 0xffff);
 294 }
 295
 296 /*
 297  * Enable or disable automatic BIOS fan control support
 298  */
 299 static int i8k_enable_fan_auto_mode(const struct dell_smm_data *data, bool enable)
 300 {
 301         struct smm_regs regs = { };
 302
 303         if (data->disallow_fan_support)
 304                 return -EINVAL;
 305
 306         regs.eax = enable ? data->auto_fan : data->manual_fan;
 307         return i8k_smm(&regs);
 308 }
 309
 310 /*
 311  * Set the fan speed (off, low, high, ...).
 312  */
 313 static int i8k_set_fan(const struct dell_smm_data *data, u8 fan, int speed)
 314 {
 315         struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
 316
 317         if (data->disallow_fan_support)
 318                 return -EINVAL;
 319
 320         speed = (speed < 0) ? 0 : ((speed > data->i8k_fan_max) ? data->i8k_fan_max : speed);
 321         regs.ebx = fan | (speed << 8);
 322
 323         return i8k_smm(&regs);
 324 }
 325
 326 static int __init i8k_get_temp_type(u8 sensor)
 327 {
 328         struct smm_regs regs = {
 329                 .eax = I8K_SMM_GET_TEMP_TYPE,
 330                 .ebx = sensor,
 331         };
 332
 333         return i8k_smm(&regs) ? : regs.eax & 0xff;
 334 }
 335
 336 /*
 337  * Read the cpu temperature.
 338  */
 339 static int _i8k_get_temp(u8 sensor)
 340 {
 341         struct smm_regs regs = {
 342                 .eax = I8K_SMM_GET_TEMP,
 343                 .ebx = sensor,
 344         };
 345
 346         return i8k_smm(&regs) ? : regs.eax & 0xff;
 347 }
 348
 349 static int i8k_get_temp(u8 sensor)
 350 {
 351         int temp = _i8k_get_temp(sensor);
 352
 353         /*
 354          * Sometimes the temperature sensor returns 0x99, which is out of range.
 355          * In this case we retry (once) before returning an error.
 356          # 1003655137 00000058 00005a4b
 357          # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
 358          # 1003655139 00000054 00005c52
 359          */
 360         if (temp == 0x99) {
 361                 msleep(100);
 362                 temp = _i8k_get_temp(sensor);
 363         }
 364         /*
 365          * Return -ENODATA for all invalid temperatures.
 366          *
 367          * Known instances are the 0x99 value as seen above as well as
 368          * 0xc1 (193), which may be returned when trying to read the GPU
 369          * temperature if the system supports a GPU and it is currently
 370          * turned off.
 371          */
 372         if (temp > I8K_MAX_TEMP)
 373                 return -ENODATA;
 374
 375         return temp;
 376 }
 377
 378 static int __init i8k_get_dell_signature(int req_fn)
 379 {
 380         struct smm_regs regs = { .eax = req_fn, };
 381         int rc;
 382
 383         rc = i8k_smm(&regs);
 384         if (rc < 0)
 385                 return rc;
 386
 387         return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 388 }
 389
 390 #if IS_ENABLED(CONFIG_I8K)
 391
 392 /*
 393  * Read the Fn key status.
 394  */
 395 static int i8k_get_fn_status(void)
 396 {
 397         struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
 398         int rc;
 399
 400         rc = i8k_smm(&regs);
 401         if (rc < 0)
 402                 return rc;
 403
 404         switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
 405         case I8K_FN_UP:
 406                 return I8K_VOL_UP;
 407         case I8K_FN_DOWN:
 408                 return I8K_VOL_DOWN;
 409         case I8K_FN_MUTE:
 410                 return I8K_VOL_MUTE;
 411         default:
 412                 return 0;
 413         }
 414 }
 415
 416 /*
 417  * Read the power status.
 418  */
 419 static int i8k_get_power_status(void)
 420 {
 421         struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
 422         int rc;
 423
 424         rc = i8k_smm(&regs);
 425         if (rc < 0)
 426                 return rc;
 427
 428         return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
 429 }
 430
 431 /*
 432  * Procfs interface
 433  */
 434
 435 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 436 {
 437         struct dell_smm_data *data = pde_data(file_inode(fp));
 438         int __user *argp = (int __user *)arg;
 439         int speed, err;
 440         int val = 0;
 441
 442         if (!argp)
 443                 return -EINVAL;
 444
 445         switch (cmd) {
 446         case I8K_BIOS_VERSION:
 447                 if (!isdigit(data->bios_version[0]) || !isdigit(data->bios_version[1]) ||
 448                     !isdigit(data->bios_version[2]))
 449                         return -EINVAL;
 450
 451                 val = (data->bios_version[0] << 16) |
 452                                 (data->bios_version[1] << 8) | data->bios_version[2];
 453
 454                 if (copy_to_user(argp, &val, sizeof(val)))
 455                         return -EFAULT;
 456
 457                 return 0;
 458         case I8K_MACHINE_ID:
 459                 if (restricted && !capable(CAP_SYS_ADMIN))
 460                         return -EPERM;
 461
 462                 if (copy_to_user(argp, data->bios_machineid, sizeof(data->bios_machineid)))
 463                         return -EFAULT;
 464
 465                 return 0;
 466         case I8K_FN_STATUS:
 467                 val = i8k_get_fn_status();
 468                 break;
 469
 470         case I8K_POWER_STATUS:
 471                 val = i8k_get_power_status();
 472                 break;
 473
 474         case I8K_GET_TEMP:
 475                 val = i8k_get_temp(0);
 476                 break;
 477
 478         case I8K_GET_SPEED:
 479                 if (copy_from_user(&val, argp, sizeof(int)))
 480                         return -EFAULT;
 481
 482                 if (val > U8_MAX || val < 0)
 483                         return -EINVAL;
 484
 485                 val = i8k_get_fan_speed(data, val);
 486                 break;
 487
 488         case I8K_GET_FAN:
 489                 if (copy_from_user(&val, argp, sizeof(int)))
 490                         return -EFAULT;
 491
 492                 if (val > U8_MAX || val < 0)
 493                         return -EINVAL;
 494
 495                 val = i8k_get_fan_status(data, val);
 496                 break;
 497
 498         case I8K_SET_FAN:
 499                 if (restricted && !capable(CAP_SYS_ADMIN))
 500                         return -EPERM;
 501
 502                 if (copy_from_user(&val, argp, sizeof(int)))
 503                         return -EFAULT;
 504
 505                 if (val > U8_MAX || val < 0)
 506                         return -EINVAL;
 507
 508                 if (copy_from_user(&speed, argp + 1, sizeof(int)))
 509                         return -EFAULT;
 510
 511                 mutex_lock(&data->i8k_mutex);
 512                 err = i8k_set_fan(data, val, speed);
 513                 if (err < 0)
 514                         val = err;
 515                 else
 516                         val = i8k_get_fan_status(data, val);
 517                 mutex_unlock(&data->i8k_mutex);
 518                 break;
 519
 520         default:
 521                 return -ENOIOCTLCMD;
 522         }
 523
 524         if (val < 0)
 525                 return val;
 526
 527         if (copy_to_user(argp, &val, sizeof(int)))
 528                 return -EFAULT;
 529
 530         return 0;
 531 }
 532
 533 /*
 534  * Print the information for /proc/i8k.
 535  */
 536 static int i8k_proc_show(struct seq_file *seq, void *offset)
 537 {
 538         struct dell_smm_data *data = seq->private;
 539         int fn_key, cpu_temp, ac_power;
 540         int left_fan, right_fan, left_speed, right_speed;
 541
 542         cpu_temp        = i8k_get_temp(0);                              /* 11100 µs */
 543         left_fan        = i8k_get_fan_status(data, I8K_FAN_LEFT);       /*   580 µs */
 544         right_fan       = i8k_get_fan_status(data, I8K_FAN_RIGHT);      /*   580 µs */
 545         left_speed      = i8k_get_fan_speed(data, I8K_FAN_LEFT);        /*   580 µs */
 546         right_speed     = i8k_get_fan_speed(data, I8K_FAN_RIGHT);       /*   580 µs */
 547         fn_key          = i8k_get_fn_status();                          /*   750 µs */
 548         if (power_status)
 549                 ac_power = i8k_get_power_status();                      /* 14700 µs */
 550         else
 551                 ac_power = -1;
 552
 553         /*
 554          * Info:
 555          *
 556          * 1)  Format version (this will change if format changes)
 557          * 2)  BIOS version
 558          * 3)  BIOS machine ID
 559          * 4)  Cpu temperature
 560          * 5)  Left fan status
 561          * 6)  Right fan status
 562          * 7)  Left fan speed
 563          * 8)  Right fan speed
 564          * 9)  AC power
 565          * 10) Fn Key status
 566          */
 567         seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
 568                    I8K_PROC_FMT,
 569                    data->bios_version,
 570                    (restricted && !capable(CAP_SYS_ADMIN)) ? "-1" : data->bios_machineid,
 571                    cpu_temp,
 572                    left_fan, right_fan, left_speed, right_speed,
 573                    ac_power, fn_key);
 574
 575         return 0;
 576 }
 577
 578 static int i8k_open_fs(struct inode *inode, struct file *file)
 579 {
 580         return single_open(file, i8k_proc_show, pde_data(inode));
 581 }
 582
 583 static const struct proc_ops i8k_proc_ops = {
 584         .proc_open      = i8k_open_fs,
 585         .proc_read      = seq_read,
 586         .proc_lseek     = seq_lseek,
 587         .proc_release   = single_release,
 588         .proc_ioctl     = i8k_ioctl,
 589 };
 590
 591 static void i8k_exit_procfs(void *param)
 592 {
 593         remove_proc_entry("i8k", NULL);
 594 }
 595
 596 static void __init i8k_init_procfs(struct device *dev)
 597 {
 598         struct dell_smm_data *data = dev_get_drvdata(dev);
 599
 600         /* Only register exit function if creation was successful */
 601         if (proc_create_data("i8k", 0, NULL, &i8k_proc_ops, data))
 602                 devm_add_action_or_reset(dev, i8k_exit_procfs, NULL);
 603 }
 604
 605 #else
 606
 607 static void __init i8k_init_procfs(struct device *dev)
 608 {
 609 }
 610
 611 #endif
 612
 613 static int dell_smm_get_max_state(struct thermal_cooling_device *dev, unsigned long *state)
 614 {
 615         struct dell_smm_cooling_data *cdata = dev->devdata;
 616
 617         *state = cdata->data->i8k_fan_max;
 618
 619         return 0;
 620 }
 621
 622 static int dell_smm_get_cur_state(struct thermal_cooling_device *dev, unsigned long *state)
 623 {
 624         struct dell_smm_cooling_data *cdata = dev->devdata;
 625         int ret;
 626
 627         ret = i8k_get_fan_status(cdata->data, cdata->fan_num);
 628         if (ret < 0)
 629                 return ret;
 630
 631         *state = ret;
 632
 633         return 0;
 634 }
 635
 636 static int dell_smm_set_cur_state(struct thermal_cooling_device *dev, unsigned long state)
 637 {
 638         struct dell_smm_cooling_data *cdata = dev->devdata;
 639         struct dell_smm_data *data = cdata->data;
 640         int ret;
 641
 642         if (state > data->i8k_fan_max)
 643                 return -EINVAL;
 644
 645         mutex_lock(&data->i8k_mutex);
 646         ret = i8k_set_fan(data, cdata->fan_num, (int)state);
 647         mutex_unlock(&data->i8k_mutex);
 648
 649         return ret;
 650 }
 651
 652 static const struct thermal_cooling_device_ops dell_smm_cooling_ops = {
 653         .get_max_state = dell_smm_get_max_state,
 654         .get_cur_state = dell_smm_get_cur_state,
 655         .set_cur_state = dell_smm_set_cur_state,
 656 };
 657
 658 static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
 659                                    int channel)
 660 {
 661         const struct dell_smm_data *data = drvdata;
 662
 663         switch (type) {
 664         case hwmon_temp:
 665                 switch (attr) {
 666                 case hwmon_temp_input:
 667                         /* _i8k_get_temp() is fine since we do not care about the actual value */
 668                         if (data->temp_type[channel] >= 0 || _i8k_get_temp(channel) >= 0)
 669                                 return 0444;
 670
 671                         break;
 672                 case hwmon_temp_label:
 673                         if (data->temp_type[channel] >= 0)
 674                                 return 0444;
 675
 676                         break;
 677                 default:
 678                         break;
 679                 }
 680                 break;
 681         case hwmon_fan:
 682                 if (data->disallow_fan_support)
 683                         break;
 684
 685                 switch (attr) {
 686                 case hwmon_fan_input:
 687                         if (data->fan[channel])
 688                                 return 0444;
 689
 690                         break;
 691                 case hwmon_fan_label:
 692                         if (data->fan[channel] && !data->disallow_fan_type_call)
 693                                 return 0444;
 694
 695                         break;
 696                 case hwmon_fan_min:
 697                 case hwmon_fan_max:
 698                 case hwmon_fan_target:
 699                         if (data->fan_nominal_speed[channel])
 700                                 return 0444;
 701
 702                         break;
 703                 default:
 704                         break;
 705                 }
 706                 break;
 707         case hwmon_pwm:
 708                 if (data->disallow_fan_support)
 709                         break;
 710
 711                 switch (attr) {
 712                 case hwmon_pwm_input:
 713                         if (data->fan[channel])
 714                                 return 0644;
 715
 716                         break;
 717                 case hwmon_pwm_enable:
 718                         if (data->auto_fan)
 719                                 /*
 720                                  * There is no command for retrieve the current status
 721                                  * from BIOS, and userspace/firmware itself can change
 722                                  * it.
 723                                  * Thus we can only provide write-only access for now.
 724                                  */
 725                                 return 0200;
 726
 727                         break;
 728                 default:
 729                         break;
 730                 }
 731                 break;
 732         default:
 733                 break;
 734         }
 735
 736         return 0;
 737 }
 738
 739 static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
 740                          long *val)
 741 {
 742         struct dell_smm_data *data = dev_get_drvdata(dev);
 743         int mult = data->i8k_fan_mult;
 744         int ret;
 745
 746         switch (type) {
 747         case hwmon_temp:
 748                 switch (attr) {
 749                 case hwmon_temp_input:
 750                         ret = i8k_get_temp(channel);
 751                         if (ret < 0)
 752                                 return ret;
 753
 754                         *val = ret * 1000;
 755
 756                         return 0;
 757                 default:
 758                         break;
 759                 }
 760                 break;
 761         case hwmon_fan:
 762                 switch (attr) {
 763                 case hwmon_fan_input:
 764                         ret = i8k_get_fan_speed(data, channel);
 765                         if (ret < 0)
 766                                 return ret;
 767
 768                         *val = ret;
 769
 770                         return 0;
 771                 case hwmon_fan_min:
 772                         *val = data->fan_nominal_speed[channel][0] * mult;
 773
 774                         return 0;
 775                 case hwmon_fan_max:
 776                         *val = data->fan_nominal_speed[channel][data->i8k_fan_max] * mult;
 777
 778                         return 0;
 779                 case hwmon_fan_target:
 780                         ret = i8k_get_fan_status(data, channel);
 781                         if (ret < 0)
 782                                 return ret;
 783
 784                         if (ret > data->i8k_fan_max)
 785                                 ret = data->i8k_fan_max;
 786
 787                         *val = data->fan_nominal_speed[channel][ret] * mult;
 788
 789                         return 0;
 790                 default:
 791                         break;
 792                 }
 793                 break;
 794         case hwmon_pwm:
 795                 switch (attr) {
 796                 case hwmon_pwm_input:
 797                         ret = i8k_get_fan_status(data, channel);
 798                         if (ret < 0)
 799                                 return ret;
 800
 801                         *val = clamp_val(ret * data->i8k_pwm_mult, 0, 255);
 802
 803                         return 0;
 804                 default:
 805                         break;
 806                 }
 807                 break;
 808         default:
 809                 break;
 810         }
 811
 812         return -EOPNOTSUPP;
 813 }
 814
 815 static const char *dell_smm_fan_label(struct dell_smm_data *data, int channel)
 816 {
 817         bool dock = false;
 818         int type = i8k_get_fan_type(data, channel);
 819
 820         if (type < 0)
 821                 return ERR_PTR(type);
 822
 823         if (type & 0x10) {
 824                 dock = true;
 825                 type &= 0x0F;
 826         }
 827
 828         if (type >= ARRAY_SIZE(fan_labels))
 829                 type = ARRAY_SIZE(fan_labels) - 1;
 830
 831         return dock ? docking_labels[type] : fan_labels[type];
 832 }
 833
 834 static int dell_smm_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 835                                 int channel, const char **str)
 836 {
 837         struct dell_smm_data *data = dev_get_drvdata(dev);
 838
 839         switch (type) {
 840         case hwmon_temp:
 841                 switch (attr) {
 842                 case hwmon_temp_label:
 843                         *str = temp_labels[data->temp_type[channel]];
 844                         return 0;
 845                 default:
 846                         break;
 847                 }
 848                 break;
 849         case hwmon_fan:
 850                 switch (attr) {
 851                 case hwmon_fan_label:
 852                         *str = dell_smm_fan_label(data, channel);
 853                         return PTR_ERR_OR_ZERO(*str);
 854                 default:
 855                         break;
 856                 }
 857                 break;
 858         default:
 859                 break;
 860         }
 861
 862         return -EOPNOTSUPP;
 863 }
 864
 865 static int dell_smm_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel,
 866                           long val)
 867 {
 868         struct dell_smm_data *data = dev_get_drvdata(dev);
 869         unsigned long pwm;
 870         bool enable;
 871         int err;
 872
 873         switch (type) {
 874         case hwmon_pwm:
 875                 switch (attr) {
 876                 case hwmon_pwm_input:
 877                         pwm = clamp_val(DIV_ROUND_CLOSEST(val, data->i8k_pwm_mult), 0,
 878                                         data->i8k_fan_max);
 879
 880                         mutex_lock(&data->i8k_mutex);
 881                         err = i8k_set_fan(data, channel, pwm);
 882                         mutex_unlock(&data->i8k_mutex);
 883
 884                         if (err < 0)
 885                                 return err;
 886
 887                         return 0;
 888                 case hwmon_pwm_enable:
 889                         if (!val)
 890                                 return -EINVAL;
 891
 892                         if (val == 1)
 893                                 enable = false;
 894                         else
 895                                 enable = true;
 896
 897                         mutex_lock(&data->i8k_mutex);
 898                         err = i8k_enable_fan_auto_mode(data, enable);
 899                         mutex_unlock(&data->i8k_mutex);
 900
 901                         if (err < 0)
 902                                 return err;
 903
 904                         return 0;
 905                 default:
 906                         break;
 907                 }
 908                 break;
 909         default:
 910                 break;
 911         }
 912
 913         return -EOPNOTSUPP;
 914 }
 915
 916 static const struct hwmon_ops dell_smm_ops = {
 917         .is_visible = dell_smm_is_visible,
 918         .read = dell_smm_read,
 919         .read_string = dell_smm_read_string,
 920         .write = dell_smm_write,
 921 };
 922
 923 static const struct hwmon_channel_info * const dell_smm_info[] = {
 924         HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
 925         HWMON_CHANNEL_INFO(temp,
 926                            HWMON_T_INPUT | HWMON_T_LABEL,
 927                            HWMON_T_INPUT | HWMON_T_LABEL,
 928                            HWMON_T_INPUT | HWMON_T_LABEL,
 929                            HWMON_T_INPUT | HWMON_T_LABEL,
 930                            HWMON_T_INPUT | HWMON_T_LABEL,
 931                            HWMON_T_INPUT | HWMON_T_LABEL,
 932                            HWMON_T_INPUT | HWMON_T_LABEL,
 933                            HWMON_T_INPUT | HWMON_T_LABEL,
 934                            HWMON_T_INPUT | HWMON_T_LABEL,
 935                            HWMON_T_INPUT | HWMON_T_LABEL
 936                            ),
 937         HWMON_CHANNEL_INFO(fan,
 938                            HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
 939                            HWMON_F_TARGET,
 940                            HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
 941                            HWMON_F_TARGET,
 942                            HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
 943                            HWMON_F_TARGET
 944                            ),
 945         HWMON_CHANNEL_INFO(pwm,
 946                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
 947                            HWMON_PWM_INPUT,
 948                            HWMON_PWM_INPUT
 949                            ),
 950         NULL
 951 };
 952
 953 static const struct hwmon_chip_info dell_smm_chip_info = {
 954         .ops = &dell_smm_ops,
 955         .info = dell_smm_info,
 956 };
 957
 958 static int __init dell_smm_init_cdev(struct device *dev, u8 fan_num)
 959 {
 960         struct dell_smm_data *data = dev_get_drvdata(dev);
 961         struct thermal_cooling_device *cdev;
 962         struct dell_smm_cooling_data *cdata;
 963         int ret = 0;
 964         char *name;
 965
 966         name = kasprintf(GFP_KERNEL, "dell-smm-fan%u", fan_num + 1);
 967         if (!name)
 968                 return -ENOMEM;
 969
 970         cdata = devm_kmalloc(dev, sizeof(*cdata), GFP_KERNEL);
 971         if (cdata) {
 972                 cdata->fan_num = fan_num;
 973                 cdata->data = data;
 974                 cdev = devm_thermal_of_cooling_device_register(dev, NULL, name, cdata,
 975                                                                &dell_smm_cooling_ops);
 976                 if (IS_ERR(cdev)) {
 977                         devm_kfree(dev, cdata);
 978                         ret = PTR_ERR(cdev);
 979                 }
 980         } else {
 981                 ret = -ENOMEM;
 982         }
 983
 984         kfree(name);
 985
 986         return ret;
 987 }
 988
 989 static int __init dell_smm_init_hwmon(struct device *dev)
 990 {
 991         struct dell_smm_data *data = dev_get_drvdata(dev);
 992         struct device *dell_smm_hwmon_dev;
 993         int state, err;
 994         u8 i;
 995
 996         for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
 997                 data->temp_type[i] = i8k_get_temp_type(i);
 998                 if (data->temp_type[i] < 0)
 999                         continue;
1000
1001                 if (data->temp_type[i] >= ARRAY_SIZE(temp_labels))
1002                         data->temp_type[i] = ARRAY_SIZE(temp_labels) - 1;
1003         }
1004
1005         for (i = 0; i < DELL_SMM_NO_FANS; i++) {
1006                 data->fan_type[i] = INT_MIN;
1007                 err = i8k_get_fan_status(data, i);
1008                 if (err < 0)
1009                         err = i8k_get_fan_type(data, i);
1010
1011                 if (err < 0)
1012                         continue;
1013
1014                 data->fan[i] = true;
1015
1016                 /* the cooling device is not critical, ignore failures */
1017                 if (IS_REACHABLE(CONFIG_THERMAL)) {
1018                         err = dell_smm_init_cdev(dev, i);
1019                         if (err < 0)
1020                                 dev_warn(dev, "Failed to register cooling device for fan %u\n",
1021                                          i + 1);
1022                 }
1023
1024                 data->fan_nominal_speed[i] = devm_kmalloc_array(dev, data->i8k_fan_max + 1,
1025                                                                 sizeof(*data->fan_nominal_speed[i]),
1026                                                                 GFP_KERNEL);
1027                 if (!data->fan_nominal_speed[i])
1028                         continue;
1029
1030                 for (state = 0; state <= data->i8k_fan_max; state++) {
1031                         err = i8k_get_fan_nominal_speed(data, i, state);
1032                         if (err < 0) {
1033                                 /* Mark nominal speed table as invalid in case of error */
1034                                 devm_kfree(dev, data->fan_nominal_speed[i]);
1035                                 data->fan_nominal_speed[i] = NULL;
1036                                 break;
1037                         }
1038                         data->fan_nominal_speed[i][state] = err;
1039                         /*
1040                          * Autodetect fan multiplier based on nominal rpm if multiplier
1041                          * was not specified as module param or in DMI. If fan reports
1042                          * rpm value too high then set multiplier to 1.
1043                          */
1044                         if (!fan_mult && err > I8K_FAN_RPM_THRESHOLD)
1045                                 data->i8k_fan_mult = 1;
1046                 }
1047         }
1048
1049         dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
1050                                                                   &dell_smm_chip_info, NULL);
1051
1052         return PTR_ERR_OR_ZERO(dell_smm_hwmon_dev);
1053 }
1054
1055 struct i8k_config_data {
1056         uint fan_mult;
1057         uint fan_max;
1058 };
1059
1060 enum i8k_configs {
1061         DELL_LATITUDE_D520,
1062         DELL_PRECISION_490,
1063         DELL_STUDIO,
1064         DELL_XPS,
1065 };
1066
1067 /*
1068  * Only use for machines which need some special configuration
1069  * in order to work correctly (e.g. if autoconfig fails on this machines).
1070  */
1071
1072 static const struct i8k_config_data i8k_config_data[] __initconst = {
1073         [DELL_LATITUDE_D520] = {
1074                 .fan_mult = 1,
1075                 .fan_max = I8K_FAN_TURBO,
1076         },
1077         [DELL_PRECISION_490] = {
1078                 .fan_mult = 1,
1079                 .fan_max = I8K_FAN_TURBO,
1080         },
1081         [DELL_STUDIO] = {
1082                 .fan_mult = 1,
1083                 .fan_max = I8K_FAN_HIGH,
1084         },
1085         [DELL_XPS] = {
1086                 .fan_mult = 1,
1087                 .fan_max = I8K_FAN_HIGH,
1088         },
1089 };
1090
1091 static const struct dmi_system_id i8k_dmi_table[] __initconst = {
1092         {
1093                 .ident = "Dell G5 5590",
1094                 .matches = {
1095                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1096                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "G5 5590"),
1097                 },
1098         },
1099         {
1100                 .ident = "Dell Inspiron",
1101                 .matches = {
1102                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1103                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1104                 },
1105         },
1106         {
1107                 .ident = "Dell Latitude",
1108                 .matches = {
1109                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
1110                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1111                 },
1112         },
1113         {
1114                 .ident = "Dell Inspiron 2",
1115                 .matches = {
1116                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1117                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
1118                 },
1119         },
1120         {
1121                 .ident = "Dell Latitude D520",
1122                 .matches = {
1123                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1124                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
1125                 },
1126                 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
1127         },
1128         {
1129                 .ident = "Dell Latitude 2",
1130                 .matches = {
1131                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1132                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
1133                 },
1134         },
1135         {       /* UK Inspiron 6400  */
1136                 .ident = "Dell Inspiron 3",
1137                 .matches = {
1138                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1139                         DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
1140                 },
1141         },
1142         {
1143                 .ident = "Dell Inspiron 3",
1144                 .matches = {
1145                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1146                         DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
1147                 },
1148         },
1149         {
1150                 .ident = "Dell Precision 490",
1151                 .matches = {
1152                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1153                         DMI_MATCH(DMI_PRODUCT_NAME,
1154                                   "Precision WorkStation 490"),
1155                 },
1156                 .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
1157         },
1158         {
1159                 .ident = "Dell Precision",
1160                 .matches = {
1161                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1162                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
1163                 },
1164         },
1165         {
1166                 .ident = "Dell Vostro",
1167                 .matches = {
1168                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1169                         DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
1170                 },
1171         },
1172         {
1173                 .ident = "Dell Studio",
1174                 .matches = {
1175                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1176                         DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
1177                 },
1178                 .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
1179         },
1180         {
1181                 .ident = "Dell XPS M140",
1182                 .matches = {
1183                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1184                         DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
1185                 },
1186                 .driver_data = (void *)&i8k_config_data[DELL_XPS],
1187         },
1188         {
1189                 .ident = "Dell XPS",
1190                 .matches = {
1191                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1192                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS"),
1193                 },
1194         },
1195         { }
1196 };
1197
1198 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
1199
1200 /*
1201  * On some machines once I8K_SMM_GET_FAN_TYPE is issued then CPU fan speed
1202  * randomly going up and down due to bug in Dell SMM or BIOS. Here is blacklist
1203  * of affected Dell machines for which we disallow I8K_SMM_GET_FAN_TYPE call.
1204  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=100121
1205  */
1206 static const struct dmi_system_id i8k_blacklist_fan_type_dmi_table[] __initconst = {
1207         {
1208                 .ident = "Dell Studio XPS 8000",
1209                 .matches = {
1210                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1211                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8000"),
1212                 },
1213         },
1214         {
1215                 .ident = "Dell Studio XPS 8100",
1216                 .matches = {
1217                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1218                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Studio XPS 8100"),
1219                 },
1220         },
1221         {
1222                 .ident = "Dell Inspiron 580",
1223                 .matches = {
1224                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1225                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 580 "),
1226                 },
1227         },
1228         {
1229                 .ident = "Dell Inspiron 3505",
1230                 .matches = {
1231                         DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1232                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 3505"),
1233                 },
1234         },
1235         { }
1236 };
1237
1238 /*
1239  * On some machines all fan related SMM functions implemented by Dell BIOS
1240  * firmware freeze kernel for about 500ms. Until Dell fixes these problems fan
1241  * support for affected blacklisted Dell machines stay disabled.
1242  * See bug: https://bugzilla.kernel.org/show_bug.cgi?id=195751
1243  */
1244 static const struct dmi_system_id i8k_blacklist_fan_support_dmi_table[] __initconst = {
1245         {
1246                 .ident = "Dell Inspiron 7720",
1247                 .matches = {
1248                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1249                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Inspiron 7720"),
1250                 },
1251         },
1252         {
1253                 .ident = "Dell Vostro 3360",
1254                 .matches = {
1255                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1256                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Vostro 3360"),
1257                 },
1258         },
1259         {
1260                 .ident = "Dell XPS13 9333",
1261                 .matches = {
1262                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1263                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS13 9333"),
1264                 },
1265         },
1266         {
1267                 .ident = "Dell XPS 15 L502X",
1268                 .matches = {
1269                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1270                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L502X"),
1271                 },
1272         },
1273         { }
1274 };
1275
1276 struct i8k_fan_control_data {
1277         unsigned int manual_fan;
1278         unsigned int auto_fan;
1279 };
1280
1281 enum i8k_fan_controls {
1282         I8K_FAN_34A3_35A3,
1283 };
1284
1285 static const struct i8k_fan_control_data i8k_fan_control_data[] __initconst = {
1286         [I8K_FAN_34A3_35A3] = {
1287                 .manual_fan = 0x34a3,
1288                 .auto_fan = 0x35a3,
1289         },
1290 };
1291
1292 static const struct dmi_system_id i8k_whitelist_fan_control[] __initconst = {
1293         {
1294                 .ident = "Dell Latitude 5480",
1295                 .matches = {
1296                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1297                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 5480"),
1298                 },
1299                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1300         },
1301         {
1302                 .ident = "Dell Latitude E6440",
1303                 .matches = {
1304                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1305                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
1306                 },
1307                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1308         },
1309         {
1310                 .ident = "Dell Latitude E7440",
1311                 .matches = {
1312                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1313                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude E7440"),
1314                 },
1315                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1316         },
1317         {
1318                 .ident = "Dell Precision 5530",
1319                 .matches = {
1320                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1321                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 5530"),
1322                 },
1323                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1324         },
1325         {
1326                 .ident = "Dell Precision 7510",
1327                 .matches = {
1328                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1329                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
1330                 },
1331                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1332         },
1333         {
1334                 .ident = "Dell XPS 13 7390",
1335                 .matches = {
1336                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
1337                         DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "XPS 13 7390"),
1338                 },
1339                 .driver_data = (void *)&i8k_fan_control_data[I8K_FAN_34A3_35A3],
1340         },
1341         { }
1342 };
1343
1344 static int __init dell_smm_probe(struct platform_device *pdev)
1345 {
1346         struct dell_smm_data *data;
1347         const struct dmi_system_id *id, *fan_control;
1348         int ret;
1349
1350         data = devm_kzalloc(&pdev->dev, sizeof(struct dell_smm_data), GFP_KERNEL);
1351         if (!data)
1352                 return -ENOMEM;
1353
1354         mutex_init(&data->i8k_mutex);
1355         platform_set_drvdata(pdev, data);
1356
1357         if (dmi_check_system(i8k_blacklist_fan_support_dmi_table)) {
1358                 if (!force) {
1359                         dev_notice(&pdev->dev, "Disabling fan support due to BIOS bugs\n");
1360                         data->disallow_fan_support = true;
1361                 } else {
1362                         dev_warn(&pdev->dev, "Enabling fan support despite BIOS bugs\n");
1363                 }
1364         }
1365
1366         if (dmi_check_system(i8k_blacklist_fan_type_dmi_table)) {
1367                 if (!force) {
1368                         dev_notice(&pdev->dev, "Disabling fan type call due to BIOS bugs\n");
1369                         data->disallow_fan_type_call = true;
1370                 } else {
1371                         dev_warn(&pdev->dev, "Enabling fan type call despite BIOS bugs\n");
1372                 }
1373         }
1374
1375         strscpy(data->bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
1376                 sizeof(data->bios_version));
1377         strscpy(data->bios_machineid, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
1378                 sizeof(data->bios_machineid));
1379
1380         /*
1381          * Set fan multiplier and maximal fan speed from dmi config
1382          * Values specified in module parameters override values from dmi
1383          */
1384         id = dmi_first_match(i8k_dmi_table);
1385         if (id && id->driver_data) {
1386                 const struct i8k_config_data *conf = id->driver_data;
1387
1388                 if (!fan_mult && conf->fan_mult)
1389                         fan_mult = conf->fan_mult;
1390
1391                 if (!fan_max && conf->fan_max)
1392                         fan_max = conf->fan_max;
1393         }
1394
1395         /* All options must not be 0 */
1396         data->i8k_fan_mult = fan_mult ? : I8K_FAN_MULT;
1397         data->i8k_fan_max = fan_max ? : I8K_FAN_HIGH;
1398         data->i8k_pwm_mult = DIV_ROUND_UP(255, data->i8k_fan_max);
1399
1400         fan_control = dmi_first_match(i8k_whitelist_fan_control);
1401         if (fan_control && fan_control->driver_data) {
1402                 const struct i8k_fan_control_data *control = fan_control->driver_data;
1403
1404                 data->manual_fan = control->manual_fan;
1405                 data->auto_fan = control->auto_fan;
1406                 dev_info(&pdev->dev, "enabling support for setting automatic/manual fan control\n");
1407         }
1408
1409         ret = dell_smm_init_hwmon(&pdev->dev);
1410         if (ret)
1411                 return ret;
1412
1413         i8k_init_procfs(&pdev->dev);
1414
1415         return 0;
1416 }
1417
1418 static struct platform_driver dell_smm_driver = {
1419         .driver         = {
1420                 .name   = KBUILD_MODNAME,
1421         },
1422 };
1423
1424 static struct platform_device *dell_smm_device;
1425
1426 /*
1427  * Probe for the presence of a supported laptop.
1428  */
1429 static int __init i8k_init(void)
1430 {
1431         /*
1432          * Get DMI information
1433          */
1434         if (!dmi_check_system(i8k_dmi_table)) {
1435                 if (!ignore_dmi && !force)
1436                         return -ENODEV;
1437
1438                 pr_info("not running on a supported Dell system.\n");
1439                 pr_info("vendor=%s, model=%s, version=%s\n",
1440                         i8k_get_dmi_data(DMI_SYS_VENDOR),
1441                         i8k_get_dmi_data(DMI_PRODUCT_NAME),
1442                         i8k_get_dmi_data(DMI_BIOS_VERSION));
1443         }
1444
1445         /*
1446          * Get SMM Dell signature
1447          */
1448         if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
1449             i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
1450                 if (!force)
1451                         return -ENODEV;
1452
1453                 pr_err("Unable to get Dell SMM signature\n");
1454         }
1455
1456         dell_smm_device = platform_create_bundle(&dell_smm_driver, dell_smm_probe, NULL, 0, NULL,
1457                                                  0);
1458
1459         return PTR_ERR_OR_ZERO(dell_smm_device);
1460 }
1461
1462 static void __exit i8k_exit(void)
1463 {
1464         platform_device_unregister(dell_smm_device);
1465         platform_driver_unregister(&dell_smm_driver);
1466 }
1467
1468 module_init(i8k_init);
1469 module_exit(i8k_exit);