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.
6 * Copyright (C) 2001 Massimo Dal Zotto <dz@debian.org>
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
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.
19 #include <linux/module.h>
20 #include <linux/types.h>
21 #include <linux/init.h>
22 #include <linux/proc_fs.h>
23 #include <linux/apm_bios.h>
24 #include <asm/uaccess.h>
27 #include <linux/i8k.h>
29 #define I8K_VERSION "1.13 14/05/2002"
31 #define I8K_SMM_FN_STATUS 0x0025
32 #define I8K_SMM_POWER_STATUS 0x0069
33 #define I8K_SMM_SET_FAN 0x01a3
34 #define I8K_SMM_GET_FAN 0x00a3
35 #define I8K_SMM_GET_SPEED 0x02a3
36 #define I8K_SMM_GET_TEMP 0x10a3
37 #define I8K_SMM_GET_DELL_SIG 0xffa3
38 #define I8K_SMM_BIOS_VERSION 0x00a6
40 #define I8K_FAN_MULT 30
41 #define I8K_MAX_TEMP 127
43 #define I8K_FN_NONE 0x00
44 #define I8K_FN_UP 0x01
45 #define I8K_FN_DOWN 0x02
46 #define I8K_FN_MUTE 0x04
47 #define I8K_FN_MASK 0x07
48 #define I8K_FN_SHIFT 8
50 #define I8K_POWER_AC 0x05
51 #define I8K_POWER_BATTERY 0x01
53 #define I8K_TEMPERATURE_BUG 1
55 #define DELL_SIGNATURE "Dell Computer"
57 static char *supported_models
[] = {
63 static char system_vendor
[48] = "?";
64 static char product_name
[48] = "?";
65 static char bios_version
[4] = "?";
66 static char serial_number
[16] = "?";
68 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
69 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
70 MODULE_LICENSE("GPL");
73 module_param(force
, bool, 0);
74 MODULE_PARM_DESC(force
, "Force loading without checking for supported models");
76 static int restricted
;
77 module_param(restricted
, bool, 0);
78 MODULE_PARM_DESC(restricted
, "Allow fan control if SYS_ADMIN capability set");
80 static int power_status
;
81 module_param(power_status
, bool, 0600);
82 MODULE_PARM_DESC(power_status
, "Report power status in /proc/i8k");
84 static ssize_t
i8k_read(struct file
*, char __user
*, size_t, loff_t
*);
85 static int i8k_ioctl(struct inode
*, struct file
*, unsigned int,
88 static struct file_operations i8k_fops
= {
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
));
109 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
111 static int i8k_smm(SMMRegisters
* regs
)
116 asm("pushl %%eax\n\t"
117 "movl 0(%%eax),%%edx\n\t"
119 "movl 4(%%eax),%%ebx\n\t"
120 "movl 8(%%eax),%%ecx\n\t"
121 "movl 12(%%eax),%%edx\n\t"
122 "movl 16(%%eax),%%esi\n\t"
123 "movl 20(%%eax),%%edi\n\t"
127 "xchgl %%eax,(%%esp)\n\t"
128 "movl %%ebx,4(%%eax)\n\t"
129 "movl %%ecx,8(%%eax)\n\t"
130 "movl %%edx,12(%%eax)\n\t"
131 "movl %%esi,16(%%eax)\n\t"
132 "movl %%edi,20(%%eax)\n\t"
134 "movl %%edx,0(%%eax)\n\t"
137 "andl $1,%%eax\n":"=a"(rc
)
139 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
141 if ((rc
!= 0) || ((regs
->eax
& 0xffff) == 0xffff) || (regs
->eax
== eax
)) {
149 * Read the bios version. Return the version as an integer corresponding
150 * to the ascii value, for example "A17" is returned as 0x00413137.
152 static int i8k_get_bios_version(void)
154 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
157 regs
.eax
= I8K_SMM_BIOS_VERSION
;
158 if ((rc
= i8k_smm(®s
)) < 0) {
166 * Read the machine id.
168 static int i8k_get_serial_number(unsigned char *buff
)
170 strlcpy(buff
, serial_number
, sizeof(serial_number
));
175 * Read the Fn key status.
177 static int i8k_get_fn_status(void)
179 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
182 regs
.eax
= I8K_SMM_FN_STATUS
;
183 if ((rc
= i8k_smm(®s
)) < 0) {
187 switch ((regs
.eax
>> I8K_FN_SHIFT
) & I8K_FN_MASK
) {
200 * Read the power status.
202 static int i8k_get_power_status(void)
204 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
207 regs
.eax
= I8K_SMM_POWER_STATUS
;
208 if ((rc
= i8k_smm(®s
)) < 0) {
212 switch (regs
.eax
& 0xff) {
221 * Read the fan status.
223 static int i8k_get_fan_status(int fan
)
225 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
228 regs
.eax
= I8K_SMM_GET_FAN
;
229 regs
.ebx
= fan
& 0xff;
230 if ((rc
= i8k_smm(®s
)) < 0) {
234 return (regs
.eax
& 0xff);
238 * Read the fan speed in RPM.
240 static int i8k_get_fan_speed(int fan
)
242 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
245 regs
.eax
= I8K_SMM_GET_SPEED
;
246 regs
.ebx
= fan
& 0xff;
247 if ((rc
= i8k_smm(®s
)) < 0) {
251 return (regs
.eax
& 0xffff) * I8K_FAN_MULT
;
255 * Set the fan speed (off, low, high). Returns the new fan status.
257 static int i8k_set_fan(int fan
, int speed
)
259 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
262 speed
= (speed
< 0) ? 0 : ((speed
> I8K_FAN_MAX
) ? I8K_FAN_MAX
: speed
);
264 regs
.eax
= I8K_SMM_SET_FAN
;
265 regs
.ebx
= (fan
& 0xff) | (speed
<< 8);
266 if ((rc
= i8k_smm(®s
)) < 0) {
270 return (i8k_get_fan_status(fan
));
274 * Read the cpu temperature.
276 static int i8k_get_cpu_temp(void)
278 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
282 #ifdef I8K_TEMPERATURE_BUG
286 regs
.eax
= I8K_SMM_GET_TEMP
;
287 if ((rc
= i8k_smm(®s
)) < 0) {
290 temp
= regs
.eax
& 0xff;
292 #ifdef I8K_TEMPERATURE_BUG
294 * Sometimes the temperature sensor returns 0x99, which is out of range.
295 * In this case we return (once) the previous cached value. For example:
296 # 1003655137 00000058 00005a4b
297 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
298 # 1003655139 00000054 00005c52
300 if (temp
> I8K_MAX_TEMP
) {
311 static int i8k_get_dell_signature(void)
313 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
316 regs
.eax
= I8K_SMM_GET_DELL_SIG
;
317 if ((rc
= i8k_smm(®s
)) < 0) {
321 if ((regs
.eax
== 1145651527) && (regs
.edx
== 1145392204)) {
328 static int i8k_ioctl(struct inode
*ip
, struct file
*fp
, unsigned int cmd
,
333 unsigned char buff
[16];
334 int __user
*argp
= (int __user
*)arg
;
340 case I8K_BIOS_VERSION
:
341 val
= i8k_get_bios_version();
346 val
= i8k_get_serial_number(buff
);
350 val
= i8k_get_fn_status();
353 case I8K_POWER_STATUS
:
354 val
= i8k_get_power_status();
358 val
= i8k_get_cpu_temp();
362 if (copy_from_user(&val
, argp
, sizeof(int))) {
365 val
= i8k_get_fan_speed(val
);
369 if (copy_from_user(&val
, argp
, sizeof(int))) {
372 val
= i8k_get_fan_status(val
);
376 if (restricted
&& !capable(CAP_SYS_ADMIN
)) {
379 if (copy_from_user(&val
, argp
, sizeof(int))) {
382 if (copy_from_user(&speed
, argp
+ 1, sizeof(int))) {
385 val
= i8k_set_fan(val
, speed
);
397 case I8K_BIOS_VERSION
:
398 if (copy_to_user(argp
, &val
, 4)) {
403 if (copy_to_user(argp
, buff
, 16)) {
408 if (copy_to_user(argp
, &val
, sizeof(int))) {
418 * Print the information for /proc/i8k.
420 static int i8k_get_info(char *buffer
, char **start
, off_t fpos
, int length
)
422 int n
, fn_key
, cpu_temp
, ac_power
;
423 int left_fan
, right_fan
, left_speed
, right_speed
;
425 cpu_temp
= i8k_get_cpu_temp(); /* 11100 µs */
426 left_fan
= i8k_get_fan_status(I8K_FAN_LEFT
); /* 580 µs */
427 right_fan
= i8k_get_fan_status(I8K_FAN_RIGHT
); /* 580 µs */
428 left_speed
= i8k_get_fan_speed(I8K_FAN_LEFT
); /* 580 µs */
429 right_speed
= i8k_get_fan_speed(I8K_FAN_RIGHT
); /* 580 µs */
430 fn_key
= i8k_get_fn_status(); /* 750 µs */
432 ac_power
= i8k_get_power_status(); /* 14700 µs */
440 * 1) Format version (this will change if format changes)
445 * 6) Right fan status
451 n
= sprintf(buffer
, "%s %s %s %d %d %d %d %d %d %d\n",
457 right_fan
, left_speed
, right_speed
, ac_power
, fn_key
);
462 static ssize_t
i8k_read(struct file
*f
, char __user
* buffer
, size_t len
,
468 n
= i8k_get_info(info
, NULL
, 0, 128);
477 if ((*fpos
+ len
) >= n
) {
481 if (copy_to_user(buffer
, info
, len
) != 0) {
489 static char *__init
string_trim(char *s
, int size
)
494 if ((len
= strlen(s
)) > size
) {
498 for (p
= s
+ len
- 1; len
&& (*p
== ' '); len
--, p
--) {
505 /* DMI code, stolen from arch/i386/kernel/dmi_scan.c */
508 * |<-- dmi->length -->|
510 * |dmi header s=N | string1,\0, ..., stringN,\0, ..., \0
512 * +-----------------------+
514 static char *__init
dmi_string(DMIHeader
* dmi
, u8 s
)
523 p
= (u8
*) dmi
+ dmi
->length
;
533 static void __init
dmi_decode(DMIHeader
* dmi
)
535 u8
*data
= (u8
*) dmi
;
540 printk("%08x ", (int)data
);
541 for (i
= 0; i
< data
[1] && i
< 64; i
++) {
542 printk("%02x ", data
[i
]);
548 case 0: /* BIOS Information */
549 p
= dmi_string(dmi
, data
[5]);
551 strlcpy(bios_version
, p
, sizeof(bios_version
));
552 string_trim(bios_version
, sizeof(bios_version
));
555 case 1: /* System Information */
556 p
= dmi_string(dmi
, data
[4]);
558 strlcpy(system_vendor
, p
, sizeof(system_vendor
));
559 string_trim(system_vendor
, sizeof(system_vendor
));
561 p
= dmi_string(dmi
, data
[5]);
563 strlcpy(product_name
, p
, sizeof(product_name
));
564 string_trim(product_name
, sizeof(product_name
));
566 p
= dmi_string(dmi
, data
[7]);
568 strlcpy(serial_number
, p
, sizeof(serial_number
));
569 string_trim(serial_number
, sizeof(serial_number
));
575 static int __init
dmi_table(u32 base
, int len
, int num
,
576 void (*fn
) (DMIHeader
*))
583 buf
= ioremap(base
, len
);
590 * Stop when we see al the items the table claimed to have
591 * or we run off the end of the table (also happens)
593 while ((i
< num
) && ((data
- buf
) < len
)) {
594 dmi
= (DMIHeader
*) data
;
596 * Avoid misparsing crud if the length of the last
599 if ((data
- buf
+ dmi
->length
) >= len
) {
605 * Don't go off the end of the data if there is
606 * stuff looking like string fill past the end
608 while (((data
- buf
) < len
) && (*data
|| data
[1])) {
619 static int __init
dmi_iterate(void (*decode
) (DMIHeader
*))
621 unsigned char buf
[20];
622 void __iomem
*p
= ioremap(0xe0000, 0x20000), *q
;
627 for (q
= p
; q
< p
+ 0x20000; q
+= 16) {
628 memcpy_fromio(buf
, q
, 20);
629 if (memcmp(buf
, "_DMI_", 5) == 0) {
630 u16 num
= buf
[13] << 8 | buf
[12];
631 u16 len
= buf
[7] << 8 | buf
[6];
632 u32 base
= buf
[11] << 24 | buf
[10] << 16 | buf
[9] << 8 | buf
[8];
634 printk(KERN_INFO
"DMI %d.%d present.\n",
635 buf
[14] >> 4, buf
[14] & 0x0F);
636 printk(KERN_INFO
"%d structures occupying %d bytes.\n",
637 buf
[13] << 8 | buf
[12], buf
[7] << 8 | buf
[6]);
638 printk(KERN_INFO
"DMI table at 0x%08X.\n",
639 buf
[11] << 24 | buf
[10] << 16 | buf
[9] << 8 |
642 if (dmi_table(base
, len
, num
, decode
) == 0) {
652 /* end of DMI code */
655 * Get DMI information.
657 static int __init
i8k_dmi_probe(void)
661 if (dmi_iterate(dmi_decode
) != 0) {
662 printk(KERN_INFO
"i8k: unable to get DMI information\n");
666 if (strncmp(system_vendor
, DELL_SIGNATURE
, strlen(DELL_SIGNATURE
)) != 0) {
667 printk(KERN_INFO
"i8k: not running on a Dell system\n");
671 for (p
= supported_models
;; p
++) {
673 printk(KERN_INFO
"i8k: unsupported model: %s\n",
677 if (strncmp(product_name
, *p
, strlen(*p
)) == 0) {
686 * Probe for the presence of a supported laptop.
688 static int __init
i8k_probe(void)
695 * Get DMI information
697 if (i8k_dmi_probe() != 0) {
698 printk(KERN_INFO
"i8k: vendor=%s, model=%s, version=%s\n",
699 system_vendor
, product_name
, bios_version
);
703 * Get SMM Dell signature
705 if (i8k_get_dell_signature() != 0) {
706 printk(KERN_INFO
"i8k: unable to get SMM Dell signature\n");
712 * Get SMM BIOS version.
714 version
= i8k_get_bios_version();
716 printk(KERN_INFO
"i8k: unable to get SMM BIOS version\n");
719 buff
[0] = (version
>> 16) & 0xff;
720 buff
[1] = (version
>> 8) & 0xff;
721 buff
[2] = (version
) & 0xff;
724 * If DMI BIOS version is unknown use SMM BIOS version.
726 if (bios_version
[0] == '?') {
727 strcpy(bios_version
, buff
);
730 * Check if the two versions match.
732 if (strncmp(buff
, bios_version
, sizeof(bios_version
)) != 0) {
734 "i8k: BIOS version mismatch: %s != %s\n", buff
,
739 if (!smm_found
&& !force
) {
749 int __init
i8k_init(void)
751 struct proc_dir_entry
*proc_i8k
;
753 /* Are we running on an supported laptop? */
754 if (i8k_probe() != 0) {
758 /* Register the proc entry */
759 proc_i8k
= create_proc_info_entry("i8k", 0, NULL
, i8k_get_info
);
763 proc_i8k
->proc_fops
= &i8k_fops
;
764 proc_i8k
->owner
= THIS_MODULE
;
767 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
774 int init_module(void)
779 void cleanup_module(void)
781 /* Remove the proc entry */
782 remove_proc_entry("i8k", NULL
);
784 printk(KERN_INFO
"i8k: module unloaded\n");
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