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/seq_file.h>
24 #include <linux/dmi.h>
25 #include <linux/capability.h>
26 #include <asm/uaccess.h>
29 #include <linux/i8k.h>
31 #define I8K_VERSION "1.14 21/02/2005"
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
43 #define I8K_FAN_MULT 30
44 #define I8K_MAX_TEMP 127
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
53 #define I8K_POWER_AC 0x05
54 #define I8K_POWER_BATTERY 0x01
56 #define I8K_TEMPERATURE_BUG 1
58 static char bios_version
[4];
60 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
61 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
62 MODULE_LICENSE("GPL");
65 module_param(force
, bool, 0);
66 MODULE_PARM_DESC(force
, "Force loading without checking for supported models");
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");
72 static int restricted
;
73 module_param(restricted
, bool, 0);
74 MODULE_PARM_DESC(restricted
, "Allow fan control if SYS_ADMIN capability set");
76 static int power_status
;
77 module_param(power_status
, bool, 0600);
78 MODULE_PARM_DESC(power_status
, "Report power status in /proc/i8k");
80 static int i8k_open_fs(struct inode
*inode
, struct file
*file
);
81 static int i8k_ioctl(struct inode
*, struct file
*, unsigned int,
84 static const struct file_operations i8k_fops
= {
89 .release
= single_release
,
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
));
102 static inline const char *i8k_get_dmi_data(int field
)
104 const char *dmi_data
= dmi_get_system_info(field
);
106 return dmi_data
&& *dmi_data
? dmi_data
: "?";
110 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
112 static int i8k_smm(struct smm_regs
*regs
)
117 #if defined(CONFIG_X86_64)
118 asm("pushq %%rax\n\t"
119 "movl 0(%%rax),%%edx\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"
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"
136 "movl %%edx,0(%%rax)\n\t"
142 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
144 asm("pushl %%eax\n\t"
145 "movl 0(%%eax),%%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"
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"
162 "movl %%edx,0(%%eax)\n\t"
165 "andl $1,%%eax\n":"=a"(rc
)
167 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
169 if (rc
!= 0 || (regs
->eax
& 0xffff) == 0xffff || regs
->eax
== eax
)
176 * Read the bios version. Return the version as an integer corresponding
177 * to the ascii value, for example "A17" is returned as 0x00413137.
179 static int i8k_get_bios_version(void)
181 struct smm_regs regs
= { .eax
= I8K_SMM_BIOS_VERSION
, };
183 return i8k_smm(®s
) ? : regs
.eax
;
187 * Read the Fn key status.
189 static int i8k_get_fn_status(void)
191 struct smm_regs regs
= { .eax
= I8K_SMM_FN_STATUS
, };
194 if ((rc
= i8k_smm(®s
)) < 0)
197 switch ((regs
.eax
>> I8K_FN_SHIFT
) & I8K_FN_MASK
) {
210 * Read the power status.
212 static int i8k_get_power_status(void)
214 struct smm_regs regs
= { .eax
= I8K_SMM_POWER_STATUS
, };
217 if ((rc
= i8k_smm(®s
)) < 0)
220 return (regs
.eax
& 0xff) == I8K_POWER_AC
? I8K_AC
: I8K_BATTERY
;
224 * Read the fan status.
226 static int i8k_get_fan_status(int fan
)
228 struct smm_regs regs
= { .eax
= I8K_SMM_GET_FAN
, };
230 regs
.ebx
= fan
& 0xff;
231 return i8k_smm(®s
) ? : regs
.eax
& 0xff;
235 * Read the fan speed in RPM.
237 static int i8k_get_fan_speed(int fan
)
239 struct smm_regs regs
= { .eax
= I8K_SMM_GET_SPEED
, };
241 regs
.ebx
= fan
& 0xff;
242 return i8k_smm(®s
) ? : (regs
.eax
& 0xffff) * I8K_FAN_MULT
;
246 * Set the fan speed (off, low, high). Returns the new fan status.
248 static int i8k_set_fan(int fan
, int speed
)
250 struct smm_regs regs
= { .eax
= I8K_SMM_SET_FAN
, };
252 speed
= (speed
< 0) ? 0 : ((speed
> I8K_FAN_MAX
) ? I8K_FAN_MAX
: speed
);
253 regs
.ebx
= (fan
& 0xff) | (speed
<< 8);
255 return i8k_smm(®s
) ? : i8k_get_fan_status(fan
);
259 * Read the cpu temperature.
261 static int i8k_get_temp(int sensor
)
263 struct smm_regs regs
= { .eax
= I8K_SMM_GET_TEMP
, };
267 #ifdef I8K_TEMPERATURE_BUG
270 regs
.ebx
= sensor
& 0xff;
271 if ((rc
= i8k_smm(®s
)) < 0)
274 temp
= regs
.eax
& 0xff;
276 #ifdef I8K_TEMPERATURE_BUG
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
284 if (temp
> I8K_MAX_TEMP
) {
295 static int i8k_get_dell_signature(int req_fn
)
297 struct smm_regs regs
= { .eax
= req_fn
, };
300 if ((rc
= i8k_smm(®s
)) < 0)
303 return regs
.eax
== 1145651527 && regs
.edx
== 1145392204 ? 0 : -1;
306 static int i8k_ioctl(struct inode
*ip
, struct file
*fp
, unsigned int cmd
,
311 unsigned char buff
[16];
312 int __user
*argp
= (int __user
*)arg
;
318 case I8K_BIOS_VERSION
:
319 val
= i8k_get_bios_version();
324 strlcpy(buff
, i8k_get_dmi_data(DMI_PRODUCT_SERIAL
), sizeof(buff
));
328 val
= i8k_get_fn_status();
331 case I8K_POWER_STATUS
:
332 val
= i8k_get_power_status();
336 val
= i8k_get_temp(0);
340 if (copy_from_user(&val
, argp
, sizeof(int)))
343 val
= i8k_get_fan_speed(val
);
347 if (copy_from_user(&val
, argp
, sizeof(int)))
350 val
= i8k_get_fan_status(val
);
354 if (restricted
&& !capable(CAP_SYS_ADMIN
))
357 if (copy_from_user(&val
, argp
, sizeof(int)))
360 if (copy_from_user(&speed
, argp
+ 1, sizeof(int)))
363 val
= i8k_set_fan(val
, speed
);
374 case I8K_BIOS_VERSION
:
375 if (copy_to_user(argp
, &val
, 4))
380 if (copy_to_user(argp
, buff
, 16))
385 if (copy_to_user(argp
, &val
, sizeof(int)))
395 * Print the information for /proc/i8k.
397 static int i8k_proc_show(struct seq_file
*seq
, void *offset
)
399 int fn_key
, cpu_temp
, ac_power
;
400 int left_fan
, right_fan
, left_speed
, right_speed
;
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 */
409 ac_power
= i8k_get_power_status(); /* 14700 µs */
416 * 1) Format version (this will change if format changes)
421 * 6) Right fan status
427 return seq_printf(seq
, "%s %s %s %d %d %d %d %d %d %d\n",
430 i8k_get_dmi_data(DMI_PRODUCT_SERIAL
),
432 left_fan
, right_fan
, left_speed
, right_speed
,
436 static int i8k_open_fs(struct inode
*inode
, struct file
*file
)
438 return single_open(file
, i8k_proc_show
, NULL
);
441 static struct dmi_system_id __initdata i8k_dmi_table
[] = {
443 .ident
= "Dell Inspiron",
445 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer"),
446 DMI_MATCH(DMI_PRODUCT_NAME
, "Inspiron"),
450 .ident
= "Dell Latitude",
452 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer"),
453 DMI_MATCH(DMI_PRODUCT_NAME
, "Latitude"),
457 .ident
= "Dell Inspiron 2",
459 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Inc."),
460 DMI_MATCH(DMI_PRODUCT_NAME
, "Inspiron"),
464 .ident
= "Dell Latitude 2",
466 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Inc."),
467 DMI_MATCH(DMI_PRODUCT_NAME
, "Latitude"),
470 { /* UK Inspiron 6400 */
471 .ident
= "Dell Inspiron 3",
473 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Inc."),
474 DMI_MATCH(DMI_PRODUCT_NAME
, "MM061"),
478 .ident
= "Dell Inspiron 3",
480 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Inc."),
481 DMI_MATCH(DMI_PRODUCT_NAME
, "MP061"),
488 * Probe for the presence of a supported laptop.
490 static int __init
i8k_probe(void)
496 * Get DMI information
498 if (!dmi_check_system(i8k_dmi_table
)) {
499 if (!ignore_dmi
&& !force
)
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
));
509 strlcpy(bios_version
, i8k_get_dmi_data(DMI_BIOS_VERSION
), sizeof(bios_version
));
512 * Get SMM Dell signature
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");
522 * Get SMM BIOS version.
524 version
= i8k_get_bios_version();
526 printk(KERN_WARNING
"i8k: unable to get SMM BIOS version\n");
528 buff
[0] = (version
>> 16) & 0xff;
529 buff
[1] = (version
>> 8) & 0xff;
530 buff
[2] = (version
) & 0xff;
533 * If DMI BIOS version is unknown use SMM BIOS version.
535 if (!dmi_get_system_info(DMI_BIOS_VERSION
))
536 strlcpy(bios_version
, buff
, sizeof(bios_version
));
539 * Check if the two versions match.
541 if (strncmp(buff
, bios_version
, sizeof(bios_version
)) != 0)
542 printk(KERN_WARNING
"i8k: BIOS version mismatch: %s != %s\n",
549 static int __init
i8k_init(void)
551 struct proc_dir_entry
*proc_i8k
;
553 /* Are we running on an supported laptop? */
557 /* Register the proc entry */
558 proc_i8k
= proc_create("i8k", 0, NULL
, &i8k_fops
);
563 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
569 static void __exit
i8k_exit(void)
571 remove_proc_entry("i8k", NULL
);
574 module_init(i8k_init
);
575 module_exit(i8k_exit
);