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/dmi.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 static char bios_version
[4];
57 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
58 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
59 MODULE_LICENSE("GPL");
62 module_param(force
, bool, 0);
63 MODULE_PARM_DESC(force
, "Force loading without checking for supported models");
65 static int ignore_dmi
;
66 module_param(ignore_dmi
, bool, 0);
67 MODULE_PARM_DESC(ignore_dmi
, "Continue probing hardware even if DMI data does not match");
69 static int restricted
;
70 module_param(restricted
, bool, 0);
71 MODULE_PARM_DESC(restricted
, "Allow fan control if SYS_ADMIN capability set");
73 static int power_status
;
74 module_param(power_status
, bool, 0600);
75 MODULE_PARM_DESC(power_status
, "Report power status in /proc/i8k");
77 static ssize_t
i8k_read(struct file
*, char __user
*, size_t, loff_t
*);
78 static int i8k_ioctl(struct inode
*, struct file
*, unsigned int,
81 static struct file_operations i8k_fops
= {
88 unsigned int ebx
__attribute__ ((packed
));
89 unsigned int ecx
__attribute__ ((packed
));
90 unsigned int edx
__attribute__ ((packed
));
91 unsigned int esi
__attribute__ ((packed
));
92 unsigned int edi
__attribute__ ((packed
));
95 static inline char *i8k_get_dmi_data(int field
)
97 return dmi_get_system_info(field
) ? : "N/A";
101 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
103 static int i8k_smm(SMMRegisters
* regs
)
108 asm("pushl %%eax\n\t"
109 "movl 0(%%eax),%%edx\n\t"
111 "movl 4(%%eax),%%ebx\n\t"
112 "movl 8(%%eax),%%ecx\n\t"
113 "movl 12(%%eax),%%edx\n\t"
114 "movl 16(%%eax),%%esi\n\t"
115 "movl 20(%%eax),%%edi\n\t"
119 "xchgl %%eax,(%%esp)\n\t"
120 "movl %%ebx,4(%%eax)\n\t"
121 "movl %%ecx,8(%%eax)\n\t"
122 "movl %%edx,12(%%eax)\n\t"
123 "movl %%esi,16(%%eax)\n\t"
124 "movl %%edi,20(%%eax)\n\t"
126 "movl %%edx,0(%%eax)\n\t"
129 "andl $1,%%eax\n":"=a"(rc
)
131 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
133 if ((rc
!= 0) || ((regs
->eax
& 0xffff) == 0xffff) || (regs
->eax
== eax
)) {
141 * Read the bios version. Return the version as an integer corresponding
142 * to the ascii value, for example "A17" is returned as 0x00413137.
144 static int i8k_get_bios_version(void)
146 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
149 regs
.eax
= I8K_SMM_BIOS_VERSION
;
150 if ((rc
= i8k_smm(®s
)) < 0) {
158 * Read the Fn key status.
160 static int i8k_get_fn_status(void)
162 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
165 regs
.eax
= I8K_SMM_FN_STATUS
;
166 if ((rc
= i8k_smm(®s
)) < 0) {
170 switch ((regs
.eax
>> I8K_FN_SHIFT
) & I8K_FN_MASK
) {
183 * Read the power status.
185 static int i8k_get_power_status(void)
187 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
190 regs
.eax
= I8K_SMM_POWER_STATUS
;
191 if ((rc
= i8k_smm(®s
)) < 0) {
195 switch (regs
.eax
& 0xff) {
204 * Read the fan status.
206 static int i8k_get_fan_status(int fan
)
208 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
211 regs
.eax
= I8K_SMM_GET_FAN
;
212 regs
.ebx
= fan
& 0xff;
213 if ((rc
= i8k_smm(®s
)) < 0) {
217 return (regs
.eax
& 0xff);
221 * Read the fan speed in RPM.
223 static int i8k_get_fan_speed(int fan
)
225 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
228 regs
.eax
= I8K_SMM_GET_SPEED
;
229 regs
.ebx
= fan
& 0xff;
230 if ((rc
= i8k_smm(®s
)) < 0) {
234 return (regs
.eax
& 0xffff) * I8K_FAN_MULT
;
238 * Set the fan speed (off, low, high). Returns the new fan status.
240 static int i8k_set_fan(int fan
, int speed
)
242 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
245 speed
= (speed
< 0) ? 0 : ((speed
> I8K_FAN_MAX
) ? I8K_FAN_MAX
: speed
);
247 regs
.eax
= I8K_SMM_SET_FAN
;
248 regs
.ebx
= (fan
& 0xff) | (speed
<< 8);
249 if ((rc
= i8k_smm(®s
)) < 0) {
253 return (i8k_get_fan_status(fan
));
257 * Read the cpu temperature.
259 static int i8k_get_cpu_temp(void)
261 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
265 #ifdef I8K_TEMPERATURE_BUG
269 regs
.eax
= I8K_SMM_GET_TEMP
;
270 if ((rc
= i8k_smm(®s
)) < 0) {
273 temp
= regs
.eax
& 0xff;
275 #ifdef I8K_TEMPERATURE_BUG
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
283 if (temp
> I8K_MAX_TEMP
) {
294 static int i8k_get_dell_signature(void)
296 SMMRegisters regs
= { 0, 0, 0, 0, 0, 0 };
299 regs
.eax
= I8K_SMM_GET_DELL_SIG
;
300 if ((rc
= i8k_smm(®s
)) < 0) {
304 if ((regs
.eax
== 1145651527) && (regs
.edx
== 1145392204)) {
311 static int i8k_ioctl(struct inode
*ip
, struct file
*fp
, unsigned int cmd
,
316 unsigned char buff
[16];
317 int __user
*argp
= (int __user
*)arg
;
323 case I8K_BIOS_VERSION
:
324 val
= i8k_get_bios_version();
329 strlcpy(buff
, i8k_get_dmi_data(DMI_PRODUCT_SERIAL
), sizeof(buff
));
333 val
= i8k_get_fn_status();
336 case I8K_POWER_STATUS
:
337 val
= i8k_get_power_status();
341 val
= i8k_get_cpu_temp();
345 if (copy_from_user(&val
, argp
, sizeof(int))) {
348 val
= i8k_get_fan_speed(val
);
352 if (copy_from_user(&val
, argp
, sizeof(int))) {
355 val
= i8k_get_fan_status(val
);
359 if (restricted
&& !capable(CAP_SYS_ADMIN
)) {
362 if (copy_from_user(&val
, argp
, sizeof(int))) {
365 if (copy_from_user(&speed
, argp
+ 1, sizeof(int))) {
368 val
= i8k_set_fan(val
, speed
);
380 case I8K_BIOS_VERSION
:
381 if (copy_to_user(argp
, &val
, 4)) {
386 if (copy_to_user(argp
, buff
, 16)) {
391 if (copy_to_user(argp
, &val
, sizeof(int))) {
401 * Print the information for /proc/i8k.
403 static int i8k_get_info(char *buffer
, char **start
, off_t fpos
, int length
)
405 int n
, fn_key
, cpu_temp
, ac_power
;
406 int left_fan
, right_fan
, left_speed
, right_speed
;
408 cpu_temp
= i8k_get_cpu_temp(); /* 11100 µs */
409 left_fan
= i8k_get_fan_status(I8K_FAN_LEFT
); /* 580 µs */
410 right_fan
= i8k_get_fan_status(I8K_FAN_RIGHT
); /* 580 µs */
411 left_speed
= i8k_get_fan_speed(I8K_FAN_LEFT
); /* 580 µs */
412 right_speed
= i8k_get_fan_speed(I8K_FAN_RIGHT
); /* 580 µs */
413 fn_key
= i8k_get_fn_status(); /* 750 µs */
415 ac_power
= i8k_get_power_status(); /* 14700 µs */
423 * 1) Format version (this will change if format changes)
428 * 6) Right fan status
434 n
= sprintf(buffer
, "%s %s %s %d %d %d %d %d %d %d\n",
437 dmi_get_system_info(DMI_PRODUCT_SERIAL
) ? : "N/A",
439 left_fan
, right_fan
, left_speed
, right_speed
,
445 static ssize_t
i8k_read(struct file
*f
, char __user
* buffer
, size_t len
,
451 n
= i8k_get_info(info
, NULL
, 0, 128);
460 if ((*fpos
+ len
) >= n
) {
464 if (copy_to_user(buffer
, info
, len
) != 0) {
472 static struct dmi_system_id __initdata i8k_dmi_table
[] = {
474 .ident
= "Dell Inspiron",
476 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer"),
477 DMI_MATCH(DMI_PRODUCT_NAME
, "Inspiron"),
481 .ident
= "Dell Latitude",
483 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer"),
484 DMI_MATCH(DMI_PRODUCT_NAME
, "Latitude"),
491 * Probe for the presence of a supported laptop.
493 static int __init
i8k_probe(void)
499 * Get DMI information
501 if (!dmi_check_system(i8k_dmi_table
)) {
502 if (!ignore_dmi
&& !force
)
505 printk(KERN_INFO
"i8k: not running on a supported Dell system.\n");
506 printk(KERN_INFO
"i8k: vendor=%s, model=%s, version=%s\n",
507 i8k_get_dmi_data(DMI_SYS_VENDOR
),
508 i8k_get_dmi_data(DMI_PRODUCT_NAME
),
509 i8k_get_dmi_data(DMI_BIOS_VERSION
));
512 strlcpy(bios_version
, i8k_get_dmi_data(DMI_BIOS_VERSION
), sizeof(bios_version
));
515 * Get SMM Dell signature
517 if (i8k_get_dell_signature() != 0) {
518 printk(KERN_ERR
"i8k: unable to get SMM Dell signature\n");
524 * Get SMM BIOS version.
526 version
= i8k_get_bios_version();
528 printk(KERN_WARNING
"i8k: unable to get SMM BIOS version\n");
530 buff
[0] = (version
>> 16) & 0xff;
531 buff
[1] = (version
>> 8) & 0xff;
532 buff
[2] = (version
) & 0xff;
535 * If DMI BIOS version is unknown use SMM BIOS version.
537 if (!dmi_get_system_info(DMI_BIOS_VERSION
))
538 strlcpy(bios_version
, buff
, sizeof(bios_version
));
541 * Check if the two versions match.
543 if (strncmp(buff
, bios_version
, sizeof(bios_version
)) != 0)
544 printk(KERN_WARNING
"i8k: BIOS version mismatch: %s != %s\n",
554 int __init
i8k_init(void)
556 struct proc_dir_entry
*proc_i8k
;
558 /* Are we running on an supported laptop? */
562 /* Register the proc entry */
563 proc_i8k
= create_proc_info_entry("i8k", 0, NULL
, i8k_get_info
);
567 proc_i8k
->proc_fops
= &i8k_fops
;
568 proc_i8k
->owner
= THIS_MODULE
;
571 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
578 int init_module(void)
583 void cleanup_module(void)
585 /* Remove the proc entry */
586 remove_proc_entry("i8k", NULL
);
588 printk(KERN_INFO
"i8k: module unloaded\n");