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 <asm/uaccess.h>
27 #include <asm/io.h>
28
29 #include <linux/i8k.h>
30
31 #define I8K_VERSION "1.14 21/02/2005"
32
33 #define I8K_SMM_FN_STATUS 0x0025
34 #define I8K_SMM_POWER_STATUS 0x0069
35 #define I8K_SMM_SET_FAN 0x01a3
36 #define I8K_SMM_GET_FAN 0x00a3
37 #define I8K_SMM_GET_SPEED 0x02a3
38 #define I8K_SMM_GET_TEMP 0x10a3
39 #define I8K_SMM_GET_DELL_SIG1 0xfea3
40 #define I8K_SMM_GET_DELL_SIG2 0xffa3
41 #define I8K_SMM_BIOS_VERSION 0x00a6
42
43 #define I8K_FAN_MULT 30
44 #define I8K_MAX_TEMP 127
45
46 #define I8K_FN_NONE 0x00
47 #define I8K_FN_UP 0x01
48 #define I8K_FN_DOWN 0x02
49 #define I8K_FN_MUTE 0x04
50 #define I8K_FN_MASK 0x07
51 #define I8K_FN_SHIFT 8
52
53 #define I8K_POWER_AC 0x05
54 #define I8K_POWER_BATTERY 0x01
55
56 #define I8K_TEMPERATURE_BUG 1
57
58 static char bios_version[4];
59
60 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
61 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
62 MODULE_LICENSE("GPL");
63
64 static int force;
65 module_param(force, bool, 0);
66 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
67
68 static int ignore_dmi;
69 module_param(ignore_dmi, bool, 0);
70 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
71
72 static int restricted;
73 module_param(restricted, bool, 0);
74 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
75
76 static int power_status;
77 module_param(power_status, bool, 0600);
78 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
79
80 static int fan_mult = I8K_FAN_MULT;
81 module_param(fan_mult, int, 0);
82 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
83
84 static int i8k_open_fs(struct inode *inode, struct file *file);
85 static int i8k_ioctl(struct inode *, struct file *, unsigned int,
86 unsigned long);
87
88 static 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 .ioctl = i8k_ioctl,
95 };
96
97 struct 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
i8k_get_dmi_data(int field)106 static 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 */
i8k_smm(struct smm_regs * regs)116 static 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 */
i8k_get_bios_version(void)183 static 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 */
i8k_get_fn_status(void)193 static 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 */
i8k_get_power_status(void)216 static 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 */
i8k_get_fan_status(int fan)230 static 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 */
i8k_get_fan_speed(int fan)241 static 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 */
i8k_set_fan(int fan,int speed)252 static 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 */
i8k_get_temp(int sensor)265 static 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
i8k_get_dell_signature(int req_fn)299 static 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
i8k_ioctl(struct inode * ip,struct file * fp,unsigned int cmd,unsigned long arg)310 static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
311 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
398 /*
399 * Print the information for /proc/i8k.
400 */
i8k_proc_show(struct seq_file * seq,void * offset)401 static int i8k_proc_show(struct seq_file *seq, void *offset)
402 {
403 int fn_key, cpu_temp, ac_power;
404 int left_fan, right_fan, left_speed, right_speed;
405
406 cpu_temp = i8k_get_temp(0); /* 11100 µs */
407 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
408 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
409 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
410 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
411 fn_key = i8k_get_fn_status(); /* 750 µs */
412 if (power_status)
413 ac_power = i8k_get_power_status(); /* 14700 µs */
414 else
415 ac_power = -1;
416
417 /*
418 * Info:
419 *
420 * 1) Format version (this will change if format changes)
421 * 2) BIOS version
422 * 3) BIOS machine ID
423 * 4) Cpu temperature
424 * 5) Left fan status
425 * 6) Right fan status
426 * 7) Left fan speed
427 * 8) Right fan speed
428 * 9) AC power
429 * 10) Fn Key status
430 */
431 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
432 I8K_PROC_FMT,
433 bios_version,
434 i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
435 cpu_temp,
436 left_fan, right_fan, left_speed, right_speed,
437 ac_power, fn_key);
438 }
439
i8k_open_fs(struct inode * inode,struct file * file)440 static int i8k_open_fs(struct inode *inode, struct file *file)
441 {
442 return single_open(file, i8k_proc_show, NULL);
443 }
444
445 static struct dmi_system_id __initdata i8k_dmi_table[] = {
446 {
447 .ident = "Dell Inspiron",
448 .matches = {
449 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
450 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
451 },
452 },
453 {
454 .ident = "Dell Latitude",
455 .matches = {
456 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
457 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
458 },
459 },
460 {
461 .ident = "Dell Inspiron 2",
462 .matches = {
463 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
464 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
465 },
466 },
467 {
468 .ident = "Dell Latitude 2",
469 .matches = {
470 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
471 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
472 },
473 },
474 { /* UK Inspiron 6400 */
475 .ident = "Dell Inspiron 3",
476 .matches = {
477 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
478 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
479 },
480 },
481 {
482 .ident = "Dell Inspiron 3",
483 .matches = {
484 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
485 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
486 },
487 },
488 {
489 .ident = "Dell Precision",
490 .matches = {
491 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
492 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
493 },
494 },
495 {
496 .ident = "Dell Vostro",
497 .matches = {
498 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
499 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
500 },
501 },
502 { }
503 };
504
505 /*
506 * Probe for the presence of a supported laptop.
507 */
i8k_probe(void)508 static int __init i8k_probe(void)
509 {
510 char buff[4];
511 int version;
512
513 /*
514 * Get DMI information
515 */
516 if (!dmi_check_system(i8k_dmi_table)) {
517 if (!ignore_dmi && !force)
518 return -ENODEV;
519
520 printk(KERN_INFO "i8k: not running on a supported Dell system.\n");
521 printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
522 i8k_get_dmi_data(DMI_SYS_VENDOR),
523 i8k_get_dmi_data(DMI_PRODUCT_NAME),
524 i8k_get_dmi_data(DMI_BIOS_VERSION));
525 }
526
527 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION), sizeof(bios_version));
528
529 /*
530 * Get SMM Dell signature
531 */
532 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
533 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
534 printk(KERN_ERR "i8k: unable to get SMM Dell signature\n");
535 if (!force)
536 return -ENODEV;
537 }
538
539 /*
540 * Get SMM BIOS version.
541 */
542 version = i8k_get_bios_version();
543 if (version <= 0) {
544 printk(KERN_WARNING "i8k: unable to get SMM BIOS version\n");
545 } else {
546 buff[0] = (version >> 16) & 0xff;
547 buff[1] = (version >> 8) & 0xff;
548 buff[2] = (version) & 0xff;
549 buff[3] = '\0';
550 /*
551 * If DMI BIOS version is unknown use SMM BIOS version.
552 */
553 if (!dmi_get_system_info(DMI_BIOS_VERSION))
554 strlcpy(bios_version, buff, sizeof(bios_version));
555
556 /*
557 * Check if the two versions match.
558 */
559 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
560 printk(KERN_WARNING "i8k: BIOS version mismatch: %s != %s\n",
561 buff, bios_version);
562 }
563
564 return 0;
565 }
566
i8k_init(void)567 static int __init i8k_init(void)
568 {
569 struct proc_dir_entry *proc_i8k;
570
571 /* Are we running on an supported laptop? */
572 if (i8k_probe())
573 return -ENODEV;
574
575 /* Register the proc entry */
576 proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
577 if (!proc_i8k)
578 return -ENOENT;
579
580 printk(KERN_INFO
581 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
582 I8K_VERSION);
583
584 return 0;
585 }
586
i8k_exit(void)587 static void __exit i8k_exit(void)
588 {
589 remove_proc_entry("i8k", NULL);
590 }
591
592 module_init(i8k_init);
593 module_exit(i8k_exit);
594