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