Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-3.10.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/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
59 static char bios_version[4];
60
61 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
62 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
63 MODULE_LICENSE("GPL");
64
65 static int force;
66 module_param(force, bool, 0);
67 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
68
69 static int ignore_dmi;
70 module_param(ignore_dmi, bool, 0);
71 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
72
73 static int restricted;
74 module_param(restricted, bool, 0);
75 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
76
77 static int power_status;
78 module_param(power_status, bool, 0600);
79 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
80
81 static int fan_mult = I8K_FAN_MULT;
82 module_param(fan_mult, int, 0);
83 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
84
85 static int i8k_open_fs(struct inode *inode, struct file *file);
86 static long i8k_ioctl(struct file *, unsigned int, 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         .unlocked_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
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  */
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  */
183 static int i8k_get_bios_version(void)
184 {
185         struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
186
187         return i8k_smm(&regs) ? : regs.eax;
188 }
189
190 /*
191  * Read the Fn key status.
192  */
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(&regs)) < 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  */
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(&regs)) < 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  */
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(&regs) ? : regs.eax & 0xff;
236 }
237
238 /*
239  * Read the fan speed in RPM.
240  */
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(&regs) ? : (regs.eax & 0xffff) * fan_mult;
247 }
248
249 /*
250  * Set the fan speed (off, low, high). Returns the new fan status.
251  */
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(&regs) ? : i8k_get_fan_status(fan);
260 }
261
262 /*
263  * Read the cpu temperature.
264  */
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(&regs)) < 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
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(&regs)) < 0)
305                 return rc;
306
307         return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
308 }
309
310 static int
311 i8k_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
398 static 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  */
412 static 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 µs */
418         left_fan        = i8k_get_fan_status(I8K_FAN_LEFT);     /*   580 µs */
419         right_fan       = i8k_get_fan_status(I8K_FAN_RIGHT);    /*   580 µs */
420         left_speed      = i8k_get_fan_speed(I8K_FAN_LEFT);      /*   580 µs */
421         right_speed     = i8k_get_fan_speed(I8K_FAN_RIGHT);     /*   580 µs */
422         fn_key          = i8k_get_fn_status();                  /*   750 µs */
423         if (power_status)
424                 ac_power = i8k_get_power_status();              /* 14700 µs */
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
451 static int i8k_open_fs(struct inode *inode, struct file *file)
452 {
453         return single_open(file, i8k_proc_show, NULL);
454 }
455
456 static 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  */
519 static 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
578 static 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
598 static void __exit i8k_exit(void)
599 {
600         remove_proc_entry("i8k", NULL);
601 }
602
603 module_init(i8k_init);
604 module_exit(i8k_exit);