1/* 2 * i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops. 3 * See http://www.debian.org/~dz/i8k/ for more information 4 * and for latest version of this driver. 5 * 6 * Copyright (C) 2001 Massimo Dal Zotto <dz@debian.org> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the 10 * Free Software Foundation; either version 2, or (at your option) any 11 * later version. 12 * 13 * This program is distributed in the hope that it will be useful, but 14 * WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * General Public License for more details. 17 */ 18 19#include <linux/module.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/smp_lock.h> 27#include <asm/uaccess.h> 28#include <asm/io.h> 29 30#include <linux/i8k.h> 31 32#define I8K_VERSION "1.14 21/02/2005" 33 34#define I8K_SMM_FN_STATUS 0x0025 35#define I8K_SMM_POWER_STATUS 0x0069 36#define I8K_SMM_SET_FAN 0x01a3 37#define I8K_SMM_GET_FAN 0x00a3 38#define I8K_SMM_GET_SPEED 0x02a3 39#define I8K_SMM_GET_TEMP 0x10a3 40#define I8K_SMM_GET_DELL_SIG1 0xfea3 41#define I8K_SMM_GET_DELL_SIG2 0xffa3 42#define I8K_SMM_BIOS_VERSION 0x00a6 43 44#define I8K_FAN_MULT 30 45#define I8K_MAX_TEMP 127 46 47#define I8K_FN_NONE 0x00 48#define I8K_FN_UP 0x01 49#define I8K_FN_DOWN 0x02 50#define I8K_FN_MUTE 0x04 51#define I8K_FN_MASK 0x07 52#define I8K_FN_SHIFT 8 53 54#define I8K_POWER_AC 0x05 55#define I8K_POWER_BATTERY 0x01 56 57#define I8K_TEMPERATURE_BUG 1 58 59static char bios_version[4]; 60 61MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)"); 62MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops"); 63MODULE_LICENSE("GPL"); 64 65static int force; 66module_param(force, bool, 0); 67MODULE_PARM_DESC(force, "Force loading without checking for supported models"); 68 69static int ignore_dmi; 70module_param(ignore_dmi, bool, 0); 71MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match"); 72 73static int restricted; 74module_param(restricted, bool, 0); 75MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set"); 76 77static int power_status; 78module_param(power_status, bool, 0600); 79MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k"); 80 81static int fan_mult = I8K_FAN_MULT; 82module_param(fan_mult, int, 0); 83MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with"); 84 85static int i8k_open_fs(struct inode *inode, struct file *file); 86static long i8k_ioctl(struct file *, unsigned int, unsigned long); 87 88static const struct file_operations i8k_fops = { 89 .owner = THIS_MODULE, 90 .open = i8k_open_fs, 91 .read = seq_read, 92 .llseek = seq_lseek, 93 .release = single_release, 94 .unlocked_ioctl = i8k_ioctl, 95}; 96 97struct smm_regs { 98 unsigned int eax; 99 unsigned int ebx __attribute__ ((packed)); 100 unsigned int ecx __attribute__ ((packed)); 101 unsigned int edx __attribute__ ((packed)); 102 unsigned int esi __attribute__ ((packed)); 103 unsigned int edi __attribute__ ((packed)); 104}; 105 106static inline const char *i8k_get_dmi_data(int field) 107{ 108 const char *dmi_data = dmi_get_system_info(field); 109 110 return dmi_data && *dmi_data ? dmi_data : "?"; 111} 112 113/* 114 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard. 115 */ 116static int i8k_smm(struct smm_regs *regs) 117{ 118 int rc; 119 int eax = regs->eax; 120 121#if defined(CONFIG_X86_64) 122 asm("pushq %%rax\n\t" 123 "movl 0(%%rax),%%edx\n\t" 124 "pushq %%rdx\n\t" 125 "movl 4(%%rax),%%ebx\n\t" 126 "movl 8(%%rax),%%ecx\n\t" 127 "movl 12(%%rax),%%edx\n\t" 128 "movl 16(%%rax),%%esi\n\t" 129 "movl 20(%%rax),%%edi\n\t" 130 "popq %%rax\n\t" 131 "out %%al,$0xb2\n\t" 132 "out %%al,$0x84\n\t" 133 "xchgq %%rax,(%%rsp)\n\t" 134 "movl %%ebx,4(%%rax)\n\t" 135 "movl %%ecx,8(%%rax)\n\t" 136 "movl %%edx,12(%%rax)\n\t" 137 "movl %%esi,16(%%rax)\n\t" 138 "movl %%edi,20(%%rax)\n\t" 139 "popq %%rdx\n\t" 140 "movl %%edx,0(%%rax)\n\t" 141 "lahf\n\t" 142 "shrl $8,%%eax\n\t" 143 "andl $1,%%eax\n" 144 :"=a"(rc) 145 : "a"(regs) 146 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory"); 147#else 148 asm("pushl %%eax\n\t" 149 "movl 0(%%eax),%%edx\n\t" 150 "push %%edx\n\t" 151 "movl 4(%%eax),%%ebx\n\t" 152 "movl 8(%%eax),%%ecx\n\t" 153 "movl 12(%%eax),%%edx\n\t" 154 "movl 16(%%eax),%%esi\n\t" 155 "movl 20(%%eax),%%edi\n\t" 156 "popl %%eax\n\t" 157 "out %%al,$0xb2\n\t" 158 "out %%al,$0x84\n\t" 159 "xchgl %%eax,(%%esp)\n\t" 160 "movl %%ebx,4(%%eax)\n\t" 161 "movl %%ecx,8(%%eax)\n\t" 162 "movl %%edx,12(%%eax)\n\t" 163 "movl %%esi,16(%%eax)\n\t" 164 "movl %%edi,20(%%eax)\n\t" 165 "popl %%edx\n\t" 166 "movl %%edx,0(%%eax)\n\t" 167 "lahf\n\t" 168 "shrl $8,%%eax\n\t" 169 "andl $1,%%eax\n":"=a"(rc) 170 : "a"(regs) 171 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory"); 172#endif 173 if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax) 174 return -EINVAL; 175 176 return 0; 177} 178 179/* 180 * Read the bios version. Return the version as an integer corresponding 181 * to the ascii value, for example "A17" is returned as 0x00413137. 182 */ 183static int i8k_get_bios_version(void) 184{ 185 struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, }; 186 187 return i8k_smm(®s) ? : regs.eax; 188} 189 190/* 191 * Read the Fn key status. 192 */ 193static int i8k_get_fn_status(void) 194{ 195 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, }; 196 int rc; 197 198 if ((rc = i8k_smm(®s)) < 0) 199 return rc; 200 201 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) { 202 case I8K_FN_UP: 203 return I8K_VOL_UP; 204 case I8K_FN_DOWN: 205 return I8K_VOL_DOWN; 206 case I8K_FN_MUTE: 207 return I8K_VOL_MUTE; 208 default: 209 return 0; 210 } 211} 212 213/* 214 * Read the power status. 215 */ 216static int i8k_get_power_status(void) 217{ 218 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, }; 219 int rc; 220 221 if ((rc = i8k_smm(®s)) < 0) 222 return rc; 223 224 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY; 225} 226 227/* 228 * Read the fan status. 229 */ 230static int i8k_get_fan_status(int fan) 231{ 232 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, }; 233 234 regs.ebx = fan & 0xff; 235 return i8k_smm(®s) ? : regs.eax & 0xff; 236} 237 238/* 239 * Read the fan speed in RPM. 240 */ 241static int i8k_get_fan_speed(int fan) 242{ 243 struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, }; 244 245 regs.ebx = fan & 0xff; 246 return i8k_smm(®s) ? : (regs.eax & 0xffff) * fan_mult; 247} 248 249/* 250 * Set the fan speed (off, low, high). Returns the new fan status. 251 */ 252static int i8k_set_fan(int fan, int speed) 253{ 254 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, }; 255 256 speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed); 257 regs.ebx = (fan & 0xff) | (speed << 8); 258 259 return i8k_smm(®s) ? : i8k_get_fan_status(fan); 260} 261 262/* 263 * Read the cpu temperature. 264 */ 265static int i8k_get_temp(int sensor) 266{ 267 struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, }; 268 int rc; 269 int temp; 270 271#ifdef I8K_TEMPERATURE_BUG 272 static int prev; 273#endif 274 regs.ebx = sensor & 0xff; 275 if ((rc = i8k_smm(®s)) < 0) 276 return rc; 277 278 temp = regs.eax & 0xff; 279 280#ifdef I8K_TEMPERATURE_BUG 281 /* 282 * Sometimes the temperature sensor returns 0x99, which is out of range. 283 * In this case we return (once) the previous cached value. For example: 284 # 1003655137 00000058 00005a4b 285 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees 286 # 1003655139 00000054 00005c52 287 */ 288 if (temp > I8K_MAX_TEMP) { 289 temp = prev; 290 prev = I8K_MAX_TEMP; 291 } else { 292 prev = temp; 293 } 294#endif 295 296 return temp; 297} 298 299static int i8k_get_dell_signature(int req_fn) 300{ 301 struct smm_regs regs = { .eax = req_fn, }; 302 int rc; 303 304 if ((rc = i8k_smm(®s)) < 0) 305 return rc; 306 307 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1; 308} 309 310static int 311i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg) 312{ 313 int val = 0; 314 int speed; 315 unsigned char buff[16]; 316 int __user *argp = (int __user *)arg; 317 318 if (!argp) 319 return -EINVAL; 320 321 switch (cmd) { 322 case I8K_BIOS_VERSION: 323 val = i8k_get_bios_version(); 324 break; 325 326 case I8K_MACHINE_ID: 327 memset(buff, 0, 16); 328 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL), sizeof(buff)); 329 break; 330 331 case I8K_FN_STATUS: 332 val = i8k_get_fn_status(); 333 break; 334 335 case I8K_POWER_STATUS: 336 val = i8k_get_power_status(); 337 break; 338 339 case I8K_GET_TEMP: 340 val = i8k_get_temp(0); 341 break; 342 343 case I8K_GET_SPEED: 344 if (copy_from_user(&val, argp, sizeof(int))) 345 return -EFAULT; 346 347 val = i8k_get_fan_speed(val); 348 break; 349 350 case I8K_GET_FAN: 351 if (copy_from_user(&val, argp, sizeof(int))) 352 return -EFAULT; 353 354 val = i8k_get_fan_status(val); 355 break; 356 357 case I8K_SET_FAN: 358 if (restricted && !capable(CAP_SYS_ADMIN)) 359 return -EPERM; 360 361 if (copy_from_user(&val, argp, sizeof(int))) 362 return -EFAULT; 363 364 if (copy_from_user(&speed, argp + 1, sizeof(int))) 365 return -EFAULT; 366 367 val = i8k_set_fan(val, speed); 368 break; 369 370 default: 371 return -EINVAL; 372 } 373 374 if (val < 0) 375 return val; 376 377 switch (cmd) { 378 case I8K_BIOS_VERSION: 379 if (copy_to_user(argp, &val, 4)) 380 return -EFAULT; 381 382 break; 383 case I8K_MACHINE_ID: 384 if (copy_to_user(argp, buff, 16)) 385 return -EFAULT; 386 387 break; 388 default: 389 if (copy_to_user(argp, &val, sizeof(int))) 390 return -EFAULT; 391 392 break; 393 } 394 395 return 0; 396} 397 398static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) 399{ 400 long ret; 401 402 lock_kernel(); 403 ret = i8k_ioctl_unlocked(fp, cmd, arg); 404 unlock_kernel(); 405 406 return ret; 407} 408 409/* 410 * Print the information for /proc/i8k. 411 */ 412static int i8k_proc_show(struct seq_file *seq, void *offset) 413{ 414 int fn_key, cpu_temp, ac_power; 415 int left_fan, right_fan, left_speed, right_speed; 416 417 cpu_temp = i8k_get_temp(0); /* 11100 ��s */ 418 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 ��s */ 419 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 ��s */ 420 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 ��s */ 421 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 ��s */ 422 fn_key = i8k_get_fn_status(); /* 750 ��s */ 423 if (power_status) 424 ac_power = i8k_get_power_status(); /* 14700 ��s */ 425 else 426 ac_power = -1; 427 428 /* 429 * Info: 430 * 431 * 1) Format version (this will change if format changes) 432 * 2) BIOS version 433 * 3) BIOS machine ID 434 * 4) Cpu temperature 435 * 5) Left fan status 436 * 6) Right fan status 437 * 7) Left fan speed 438 * 8) Right fan speed 439 * 9) AC power 440 * 10) Fn Key status 441 */ 442 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n", 443 I8K_PROC_FMT, 444 bios_version, 445 i8k_get_dmi_data(DMI_PRODUCT_SERIAL), 446 cpu_temp, 447 left_fan, right_fan, left_speed, right_speed, 448 ac_power, fn_key); 449} 450 451static int i8k_open_fs(struct inode *inode, struct file *file) 452{ 453 return single_open(file, i8k_proc_show, NULL); 454} 455 456static struct dmi_system_id __initdata i8k_dmi_table[] = { 457 { 458 .ident = "Dell Inspiron", 459 .matches = { 460 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"), 461 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"), 462 }, 463 }, 464 { 465 .ident = "Dell Latitude", 466 .matches = { 467 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"), 468 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"), 469 }, 470 }, 471 { 472 .ident = "Dell Inspiron 2", 473 .matches = { 474 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 475 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"), 476 }, 477 }, 478 { 479 .ident = "Dell Latitude 2", 480 .matches = { 481 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 482 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"), 483 }, 484 }, 485 { /* UK Inspiron 6400 */ 486 .ident = "Dell Inspiron 3", 487 .matches = { 488 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 489 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"), 490 }, 491 }, 492 { 493 .ident = "Dell Inspiron 3", 494 .matches = { 495 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 496 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"), 497 }, 498 }, 499 { 500 .ident = "Dell Precision", 501 .matches = { 502 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 503 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"), 504 }, 505 }, 506 { 507 .ident = "Dell Vostro", 508 .matches = { 509 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 510 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"), 511 }, 512 }, 513 { } 514}; 515 516/* 517 * Probe for the presence of a supported laptop. 518 */ 519static int __init i8k_probe(void) 520{ 521 char buff[4]; 522 int version; 523 524 /* 525 * Get DMI information 526 */ 527 if (!dmi_check_system(i8k_dmi_table)) { 528 if (!ignore_dmi && !force) 529 return -ENODEV; 530 531 printk(KERN_INFO "i8k: not running on a supported Dell system.\n"); 532 printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n", 533 i8k_get_dmi_data(DMI_SYS_VENDOR), 534 i8k_get_dmi_data(DMI_PRODUCT_NAME), 535 i8k_get_dmi_data(DMI_BIOS_VERSION)); 536 } 537 538 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION), sizeof(bios_version)); 539 540 /* 541 * Get SMM Dell signature 542 */ 543 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) && 544 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) { 545 printk(KERN_ERR "i8k: unable to get SMM Dell signature\n"); 546 if (!force) 547 return -ENODEV; 548 } 549 550 /* 551 * Get SMM BIOS version. 552 */ 553 version = i8k_get_bios_version(); 554 if (version <= 0) { 555 printk(KERN_WARNING "i8k: unable to get SMM BIOS version\n"); 556 } else { 557 buff[0] = (version >> 16) & 0xff; 558 buff[1] = (version >> 8) & 0xff; 559 buff[2] = (version) & 0xff; 560 buff[3] = '\0'; 561 /* 562 * If DMI BIOS version is unknown use SMM BIOS version. 563 */ 564 if (!dmi_get_system_info(DMI_BIOS_VERSION)) 565 strlcpy(bios_version, buff, sizeof(bios_version)); 566 567 /* 568 * Check if the two versions match. 569 */ 570 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0) 571 printk(KERN_WARNING "i8k: BIOS version mismatch: %s != %s\n", 572 buff, bios_version); 573 } 574 575 return 0; 576} 577 578static int __init i8k_init(void) 579{ 580 struct proc_dir_entry *proc_i8k; 581 582 /* Are we running on an supported laptop? */ 583 if (i8k_probe()) 584 return -ENODEV; 585 586 /* Register the proc entry */ 587 proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops); 588 if (!proc_i8k) 589 return -ENOENT; 590 591 printk(KERN_INFO 592 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n", 593 I8K_VERSION); 594 595 return 0; 596} 597 598static void __exit i8k_exit(void) 599{ 600 remove_proc_entry("i8k", NULL); 601} 602 603module_init(i8k_init); 604module_exit(i8k_exit); 605