ee017166545ebc7dea19c91e9539ab9bb064277e
[linux-2.6.git] / drivers / char / i8k.c
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/mutex.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
59 static DEFINE_MUTEX(i8k_mutex);
60 static char bios_version[4];
61
62 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
63 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
64 MODULE_LICENSE("GPL");
65
66 static int force;
67 module_param(force, bool, 0);
68 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
69
70 static int ignore_dmi;
71 module_param(ignore_dmi, bool, 0);
72 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
73
74 static int restricted;
75 module_param(restricted, bool, 0);
76 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
77
78 static int power_status;
79 module_param(power_status, bool, 0600);
80 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
81
82 static int fan_mult = I8K_FAN_MULT;
83 module_param(fan_mult, int, 0);
84 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
85
86 static int i8k_open_fs(struct inode *inode, struct file *file);
87 static long i8k_ioctl(struct file *, unsigned int, unsigned long);
88
89 static const struct file_operations i8k_fops = {
90         .owner          = THIS_MODULE,
91         .open           = i8k_open_fs,
92         .read           = seq_read,
93         .llseek         = seq_lseek,
94         .release        = single_release,
95         .unlocked_ioctl = i8k_ioctl,
96 };
97
98 struct smm_regs {
99         unsigned int eax;
100         unsigned int ebx __attribute__ ((packed));
101         unsigned int ecx __attribute__ ((packed));
102         unsigned int edx __attribute__ ((packed));
103         unsigned int esi __attribute__ ((packed));
104         unsigned int edi __attribute__ ((packed));
105 };
106
107 static inline const char *i8k_get_dmi_data(int field)
108 {
109         const char *dmi_data = dmi_get_system_info(field);
110
111         return dmi_data && *dmi_data ? dmi_data : "?";
112 }
113
114 /*
115  * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
116  */
117 static int i8k_smm(struct smm_regs *regs)
118 {
119         int rc;
120         int eax = regs->eax;
121
122 #if defined(CONFIG_X86_64)
123         asm volatile("pushq %%rax\n\t"
124                 "movl 0(%%rax),%%edx\n\t"
125                 "pushq %%rdx\n\t"
126                 "movl 4(%%rax),%%ebx\n\t"
127                 "movl 8(%%rax),%%ecx\n\t"
128                 "movl 12(%%rax),%%edx\n\t"
129                 "movl 16(%%rax),%%esi\n\t"
130                 "movl 20(%%rax),%%edi\n\t"
131                 "popq %%rax\n\t"
132                 "out %%al,$0xb2\n\t"
133                 "out %%al,$0x84\n\t"
134                 "xchgq %%rax,(%%rsp)\n\t"
135                 "movl %%ebx,4(%%rax)\n\t"
136                 "movl %%ecx,8(%%rax)\n\t"
137                 "movl %%edx,12(%%rax)\n\t"
138                 "movl %%esi,16(%%rax)\n\t"
139                 "movl %%edi,20(%%rax)\n\t"
140                 "popq %%rdx\n\t"
141                 "movl %%edx,0(%%rax)\n\t"
142                 "pushfq\n\t"
143                 "popq %%rax\n\t"
144                 "andl $1,%%eax\n"
145                 :"=a"(rc)
146                 :    "a"(regs)
147                 :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
148 #else
149         asm volatile("pushl %%eax\n\t"
150             "movl 0(%%eax),%%edx\n\t"
151             "push %%edx\n\t"
152             "movl 4(%%eax),%%ebx\n\t"
153             "movl 8(%%eax),%%ecx\n\t"
154             "movl 12(%%eax),%%edx\n\t"
155             "movl 16(%%eax),%%esi\n\t"
156             "movl 20(%%eax),%%edi\n\t"
157             "popl %%eax\n\t"
158             "out %%al,$0xb2\n\t"
159             "out %%al,$0x84\n\t"
160             "xchgl %%eax,(%%esp)\n\t"
161             "movl %%ebx,4(%%eax)\n\t"
162             "movl %%ecx,8(%%eax)\n\t"
163             "movl %%edx,12(%%eax)\n\t"
164             "movl %%esi,16(%%eax)\n\t"
165             "movl %%edi,20(%%eax)\n\t"
166             "popl %%edx\n\t"
167             "movl %%edx,0(%%eax)\n\t"
168             "lahf\n\t"
169             "shrl $8,%%eax\n\t"
170             "andl $1,%%eax\n"
171             :"=a"(rc)
172             :    "a"(regs)
173             :    "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
174 #endif
175         if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
176                 return -EINVAL;
177
178         return 0;
179 }
180
181 /*
182  * Read the bios version. Return the version as an integer corresponding
183  * to the ascii value, for example "A17" is returned as 0x00413137.
184  */
185 static int i8k_get_bios_version(void)
186 {
187         struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
188
189         return i8k_smm(&regs) ? : regs.eax;
190 }
191
192 /*
193  * Read the Fn key status.
194  */
195 static int i8k_get_fn_status(void)
196 {
197         struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
198         int rc;
199
200         if ((rc = i8k_smm(&regs)) < 0)
201                 return rc;
202
203         switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
204         case I8K_FN_UP:
205                 return I8K_VOL_UP;
206         case I8K_FN_DOWN:
207                 return I8K_VOL_DOWN;
208         case I8K_FN_MUTE:
209                 return I8K_VOL_MUTE;
210         default:
211                 return 0;
212         }
213 }
214
215 /*
216  * Read the power status.
217  */
218 static int i8k_get_power_status(void)
219 {
220         struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
221         int rc;
222
223         if ((rc = i8k_smm(&regs)) < 0)
224                 return rc;
225
226         return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
227 }
228
229 /*
230  * Read the fan status.
231  */
232 static int i8k_get_fan_status(int fan)
233 {
234         struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
235
236         regs.ebx = fan & 0xff;
237         return i8k_smm(&regs) ? : regs.eax & 0xff;
238 }
239
240 /*
241  * Read the fan speed in RPM.
242  */
243 static int i8k_get_fan_speed(int fan)
244 {
245         struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
246
247         regs.ebx = fan & 0xff;
248         return i8k_smm(&regs) ? : (regs.eax & 0xffff) * fan_mult;
249 }
250
251 /*
252  * Set the fan speed (off, low, high). Returns the new fan status.
253  */
254 static int i8k_set_fan(int fan, int speed)
255 {
256         struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
257
258         speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
259         regs.ebx = (fan & 0xff) | (speed << 8);
260
261         return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
262 }
263
264 /*
265  * Read the cpu temperature.
266  */
267 static int i8k_get_temp(int sensor)
268 {
269         struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
270         int rc;
271         int temp;
272
273 #ifdef I8K_TEMPERATURE_BUG
274         static int prev;
275 #endif
276         regs.ebx = sensor & 0xff;
277         if ((rc = i8k_smm(&regs)) < 0)
278                 return rc;
279
280         temp = regs.eax & 0xff;
281
282 #ifdef I8K_TEMPERATURE_BUG
283         /*
284          * Sometimes the temperature sensor returns 0x99, which is out of range.
285          * In this case we return (once) the previous cached value. For example:
286          # 1003655137 00000058 00005a4b
287          # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
288          # 1003655139 00000054 00005c52
289          */
290         if (temp > I8K_MAX_TEMP) {
291                 temp = prev;
292                 prev = I8K_MAX_TEMP;
293         } else {
294                 prev = temp;
295         }
296 #endif
297
298         return temp;
299 }
300
301 static int i8k_get_dell_signature(int req_fn)
302 {
303         struct smm_regs regs = { .eax = req_fn, };
304         int rc;
305
306         if ((rc = i8k_smm(&regs)) < 0)
307                 return rc;
308
309         return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
310 }
311
312 static int
313 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
314 {
315         int val = 0;
316         int speed;
317         unsigned char buff[16];
318         int __user *argp = (int __user *)arg;
319
320         if (!argp)
321                 return -EINVAL;
322
323         switch (cmd) {
324         case I8K_BIOS_VERSION:
325                 val = i8k_get_bios_version();
326                 break;
327
328         case I8K_MACHINE_ID:
329                 memset(buff, 0, 16);
330                 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL), sizeof(buff));
331                 break;
332
333         case I8K_FN_STATUS:
334                 val = i8k_get_fn_status();
335                 break;
336
337         case I8K_POWER_STATUS:
338                 val = i8k_get_power_status();
339                 break;
340
341         case I8K_GET_TEMP:
342                 val = i8k_get_temp(0);
343                 break;
344
345         case I8K_GET_SPEED:
346                 if (copy_from_user(&val, argp, sizeof(int)))
347                         return -EFAULT;
348
349                 val = i8k_get_fan_speed(val);
350                 break;
351
352         case I8K_GET_FAN:
353                 if (copy_from_user(&val, argp, sizeof(int)))
354                         return -EFAULT;
355
356                 val = i8k_get_fan_status(val);
357                 break;
358
359         case I8K_SET_FAN:
360                 if (restricted && !capable(CAP_SYS_ADMIN))
361                         return -EPERM;
362
363                 if (copy_from_user(&val, argp, sizeof(int)))
364                         return -EFAULT;
365
366                 if (copy_from_user(&speed, argp + 1, sizeof(int)))
367                         return -EFAULT;
368
369                 val = i8k_set_fan(val, speed);
370                 break;
371
372         default:
373                 return -EINVAL;
374         }
375
376         if (val < 0)
377                 return val;
378
379         switch (cmd) {
380         case I8K_BIOS_VERSION:
381                 if (copy_to_user(argp, &val, 4))
382                         return -EFAULT;
383
384                 break;
385         case I8K_MACHINE_ID:
386                 if (copy_to_user(argp, buff, 16))
387                         return -EFAULT;
388
389                 break;
390         default:
391                 if (copy_to_user(argp, &val, sizeof(int)))
392                         return -EFAULT;
393
394                 break;
395         }
396
397         return 0;
398 }
399
400 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
401 {
402         long ret;
403
404         mutex_lock(&i8k_mutex);
405         ret = i8k_ioctl_unlocked(fp, cmd, arg);
406         mutex_unlock(&i8k_mutex);
407
408         return ret;
409 }
410
411 /*
412  * Print the information for /proc/i8k.
413  */
414 static int i8k_proc_show(struct seq_file *seq, void *offset)
415 {
416         int fn_key, cpu_temp, ac_power;
417         int left_fan, right_fan, left_speed, right_speed;
418
419         cpu_temp        = i8k_get_temp(0);                      /* 11100 µs */
420         left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
421         right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
422         left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
423         right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
424         fn_key          = i8k_get_fn_status();                  /*   750 µs */
425         if (power_status)
426                 ac_power = i8k_get_power_status();              /* 14700 µs */
427         else
428                 ac_power = -1;
429
430         /*
431          * Info:
432          *
433          * 1)  Format version (this will change if format changes)
434          * 2)  BIOS version
435          * 3)  BIOS machine ID
436          * 4)  Cpu temperature
437          * 5)  Left fan status
438          * 6)  Right fan status
439          * 7)  Left fan speed
440          * 8)  Right fan speed
441          * 9)  AC power
442          * 10) Fn Key status
443          */
444         return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
445                           I8K_PROC_FMT,
446                           bios_version,
447                           i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
448                           cpu_temp,
449                           left_fan, right_fan, left_speed, right_speed,
450                           ac_power, fn_key);
451 }
452
453 static int i8k_open_fs(struct inode *inode, struct file *file)
454 {
455         return single_open(file, i8k_proc_show, NULL);
456 }
457
458 static struct dmi_system_id __initdata i8k_dmi_table[] = {
459         {
460                 .ident = "Dell Inspiron",
461                 .matches = {
462                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
463                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
464                 },
465         },
466         {
467                 .ident = "Dell Latitude",
468                 .matches = {
469                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
470                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
471                 },
472         },
473         {
474                 .ident = "Dell Inspiron 2",
475                 .matches = {
476                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
477                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
478                 },
479         },
480         {
481                 .ident = "Dell Latitude 2",
482                 .matches = {
483                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
484                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
485                 },
486         },
487         {       /* UK Inspiron 6400  */
488                 .ident = "Dell Inspiron 3",
489                 .matches = {
490                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
491                         DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
492                 },
493         },
494         {
495                 .ident = "Dell Inspiron 3",
496                 .matches = {
497                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
498                         DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
499                 },
500         },
501         {
502                 .ident = "Dell Precision",
503                 .matches = {
504                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
505                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
506                 },
507         },
508         {
509                 .ident = "Dell Vostro",
510                 .matches = {
511                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
512                         DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
513                 },
514         },
515         { }
516 };
517
518 /*
519  * Probe for the presence of a supported laptop.
520  */
521 static int __init i8k_probe(void)
522 {
523         char buff[4];
524         int version;
525
526         /*
527          * Get DMI information
528          */
529         if (!dmi_check_system(i8k_dmi_table)) {
530                 if (!ignore_dmi && !force)
531                         return -ENODEV;
532
533                 printk(KERN_INFO "i8k: not running on a supported Dell system.\n");
534                 printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
535                         i8k_get_dmi_data(DMI_SYS_VENDOR),
536                         i8k_get_dmi_data(DMI_PRODUCT_NAME),
537                         i8k_get_dmi_data(DMI_BIOS_VERSION));
538         }
539
540         strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION), sizeof(bios_version));
541
542         /*
543          * Get SMM Dell signature
544          */
545         if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
546             i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
547                 printk(KERN_ERR "i8k: unable to get SMM Dell signature\n");
548                 if (!force)
549                         return -ENODEV;
550         }
551
552         /*
553          * Get SMM BIOS version.
554          */
555         version = i8k_get_bios_version();
556         if (version <= 0) {
557                 printk(KERN_WARNING "i8k: unable to get SMM BIOS version\n");
558         } else {
559                 buff[0] = (version >> 16) & 0xff;
560                 buff[1] = (version >> 8) & 0xff;
561                 buff[2] = (version) & 0xff;
562                 buff[3] = '\0';
563                 /*
564                  * If DMI BIOS version is unknown use SMM BIOS version.
565                  */
566                 if (!dmi_get_system_info(DMI_BIOS_VERSION))
567                         strlcpy(bios_version, buff, sizeof(bios_version));
568
569                 /*
570                  * Check if the two versions match.
571                  */
572                 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
573                         printk(KERN_WARNING "i8k: BIOS version mismatch: %s != %s\n",
574                                 buff, bios_version);
575         }
576
577         return 0;
578 }
579
580 static int __init i8k_init(void)
581 {
582         struct proc_dir_entry *proc_i8k;
583
584         /* Are we running on an supported laptop? */
585         if (i8k_probe())
586                 return -ENODEV;
587
588         /* Register the proc entry */
589         proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
590         if (!proc_i8k)
591                 return -ENOENT;
592
593         printk(KERN_INFO
594                "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
595                I8K_VERSION);
596
597         return 0;
598 }
599
600 static void __exit i8k_exit(void)
601 {
602         remove_proc_entry("i8k", NULL);
603 }
604
605 module_init(i8k_init);
606 module_exit(i8k_exit);