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