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 <asm/uaccess.h>
28 #include <linux/i8k.h>
30 #define I8K_VERSION "1.14 21/02/2005"
32 #define I8K_SMM_FN_STATUS 0x0025
33 #define I8K_SMM_POWER_STATUS 0x0069
34 #define I8K_SMM_SET_FAN 0x01a3
35 #define I8K_SMM_GET_FAN 0x00a3
36 #define I8K_SMM_GET_SPEED 0x02a3
37 #define I8K_SMM_GET_TEMP 0x10a3
38 #define I8K_SMM_GET_DELL_SIG 0xffa3
39 #define I8K_SMM_BIOS_VERSION 0x00a6
41 #define I8K_FAN_MULT 30
42 #define I8K_MAX_TEMP 127
44 #define I8K_FN_NONE 0x00
45 #define I8K_FN_UP 0x01
46 #define I8K_FN_DOWN 0x02
47 #define I8K_FN_MUTE 0x04
48 #define I8K_FN_MASK 0x07
49 #define I8K_FN_SHIFT 8
51 #define I8K_POWER_AC 0x05
52 #define I8K_POWER_BATTERY 0x01
54 #define I8K_TEMPERATURE_BUG 1
56 static char bios_version
[4];
58 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
59 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
60 MODULE_LICENSE("GPL");
63 module_param(force
, bool, 0);
64 MODULE_PARM_DESC(force
, "Force loading without checking for supported models");
66 static int ignore_dmi
;
67 module_param(ignore_dmi
, bool, 0);
68 MODULE_PARM_DESC(ignore_dmi
, "Continue probing hardware even if DMI data does not match");
70 static int restricted
;
71 module_param(restricted
, bool, 0);
72 MODULE_PARM_DESC(restricted
, "Allow fan control if SYS_ADMIN capability set");
74 static int power_status
;
75 module_param(power_status
, bool, 0600);
76 MODULE_PARM_DESC(power_status
, "Report power status in /proc/i8k");
78 static int i8k_open_fs(struct inode
*inode
, struct file
*file
);
79 static int i8k_ioctl(struct inode
*, struct file
*, unsigned int,
82 static struct file_operations i8k_fops
= {
86 .release
= single_release
,
92 unsigned int ebx
__attribute__ ((packed
));
93 unsigned int ecx
__attribute__ ((packed
));
94 unsigned int edx
__attribute__ ((packed
));
95 unsigned int esi
__attribute__ ((packed
));
96 unsigned int edi
__attribute__ ((packed
));
99 static inline char *i8k_get_dmi_data(int field
)
101 return dmi_get_system_info(field
) ? : "N/A";
105 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
107 static int i8k_smm(struct smm_regs
*regs
)
112 asm("pushl %%eax\n\t"
113 "movl 0(%%eax),%%edx\n\t"
115 "movl 4(%%eax),%%ebx\n\t"
116 "movl 8(%%eax),%%ecx\n\t"
117 "movl 12(%%eax),%%edx\n\t"
118 "movl 16(%%eax),%%esi\n\t"
119 "movl 20(%%eax),%%edi\n\t"
123 "xchgl %%eax,(%%esp)\n\t"
124 "movl %%ebx,4(%%eax)\n\t"
125 "movl %%ecx,8(%%eax)\n\t"
126 "movl %%edx,12(%%eax)\n\t"
127 "movl %%esi,16(%%eax)\n\t"
128 "movl %%edi,20(%%eax)\n\t"
130 "movl %%edx,0(%%eax)\n\t"
133 "andl $1,%%eax\n":"=a"(rc
)
135 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
137 if (rc
!= 0 || (regs
->eax
& 0xffff) == 0xffff || regs
->eax
== eax
)
144 * Read the bios version. Return the version as an integer corresponding
145 * to the ascii value, for example "A17" is returned as 0x00413137.
147 static int i8k_get_bios_version(void)
149 struct smm_regs regs
= { .eax
= I8K_SMM_BIOS_VERSION
, };
151 return i8k_smm(®s
) ? : regs
.eax
;
155 * Read the Fn key status.
157 static int i8k_get_fn_status(void)
159 struct smm_regs regs
= { .eax
= I8K_SMM_FN_STATUS
, };
162 if ((rc
= i8k_smm(®s
)) < 0)
165 switch ((regs
.eax
>> I8K_FN_SHIFT
) & I8K_FN_MASK
) {
178 * Read the power status.
180 static int i8k_get_power_status(void)
182 struct smm_regs regs
= { .eax
= I8K_SMM_POWER_STATUS
, };
185 if ((rc
= i8k_smm(®s
)) < 0)
188 return (regs
.eax
& 0xff) == I8K_POWER_AC
? I8K_AC
: I8K_BATTERY
;
192 * Read the fan status.
194 static int i8k_get_fan_status(int fan
)
196 struct smm_regs regs
= { .eax
= I8K_SMM_GET_FAN
, };
198 regs
.ebx
= fan
& 0xff;
199 return i8k_smm(®s
) ? : regs
.eax
& 0xff;
203 * Read the fan speed in RPM.
205 static int i8k_get_fan_speed(int fan
)
207 struct smm_regs regs
= { .eax
= I8K_SMM_GET_SPEED
, };
209 regs
.ebx
= fan
& 0xff;
210 return i8k_smm(®s
) ? : (regs
.eax
& 0xffff) * I8K_FAN_MULT
;
214 * Set the fan speed (off, low, high). Returns the new fan status.
216 static int i8k_set_fan(int fan
, int speed
)
218 struct smm_regs regs
= { .eax
= I8K_SMM_SET_FAN
, };
220 speed
= (speed
< 0) ? 0 : ((speed
> I8K_FAN_MAX
) ? I8K_FAN_MAX
: speed
);
221 regs
.ebx
= (fan
& 0xff) | (speed
<< 8);
223 return i8k_smm(®s
) ? : i8k_get_fan_status(fan
);
227 * Read the cpu temperature.
229 static int i8k_get_cpu_temp(void)
231 struct smm_regs regs
= { .eax
= I8K_SMM_GET_TEMP
, };
235 #ifdef I8K_TEMPERATURE_BUG
239 if ((rc
= i8k_smm(®s
)) < 0)
242 temp
= regs
.eax
& 0xff;
244 #ifdef I8K_TEMPERATURE_BUG
246 * Sometimes the temperature sensor returns 0x99, which is out of range.
247 * In this case we return (once) the previous cached value. For example:
248 # 1003655137 00000058 00005a4b
249 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
250 # 1003655139 00000054 00005c52
252 if (temp
> I8K_MAX_TEMP
) {
263 static int i8k_get_dell_signature(void)
265 struct smm_regs regs
= { .eax
= I8K_SMM_GET_DELL_SIG
, };
268 if ((rc
= i8k_smm(®s
)) < 0)
271 return regs
.eax
== 1145651527 && regs
.edx
== 1145392204 ? 0 : -1;
274 static int i8k_ioctl(struct inode
*ip
, struct file
*fp
, unsigned int cmd
,
279 unsigned char buff
[16];
280 int __user
*argp
= (int __user
*)arg
;
286 case I8K_BIOS_VERSION
:
287 val
= i8k_get_bios_version();
292 strlcpy(buff
, i8k_get_dmi_data(DMI_PRODUCT_SERIAL
), sizeof(buff
));
296 val
= i8k_get_fn_status();
299 case I8K_POWER_STATUS
:
300 val
= i8k_get_power_status();
304 val
= i8k_get_cpu_temp();
308 if (copy_from_user(&val
, argp
, sizeof(int)))
311 val
= i8k_get_fan_speed(val
);
315 if (copy_from_user(&val
, argp
, sizeof(int)))
318 val
= i8k_get_fan_status(val
);
322 if (restricted
&& !capable(CAP_SYS_ADMIN
))
325 if (copy_from_user(&val
, argp
, sizeof(int)))
328 if (copy_from_user(&speed
, argp
+ 1, sizeof(int)))
331 val
= i8k_set_fan(val
, speed
);
342 case I8K_BIOS_VERSION
:
343 if (copy_to_user(argp
, &val
, 4))
348 if (copy_to_user(argp
, buff
, 16))
353 if (copy_to_user(argp
, &val
, sizeof(int)))
363 * Print the information for /proc/i8k.
365 static int i8k_proc_show(struct seq_file
*seq
, void *offset
)
367 int fn_key
, cpu_temp
, ac_power
;
368 int left_fan
, right_fan
, left_speed
, right_speed
;
370 cpu_temp
= i8k_get_cpu_temp(); /* 11100 µs */
371 left_fan
= i8k_get_fan_status(I8K_FAN_LEFT
); /* 580 µs */
372 right_fan
= i8k_get_fan_status(I8K_FAN_RIGHT
); /* 580 µs */
373 left_speed
= i8k_get_fan_speed(I8K_FAN_LEFT
); /* 580 µs */
374 right_speed
= i8k_get_fan_speed(I8K_FAN_RIGHT
); /* 580 µs */
375 fn_key
= i8k_get_fn_status(); /* 750 µs */
377 ac_power
= i8k_get_power_status(); /* 14700 µs */
384 * 1) Format version (this will change if format changes)
389 * 6) Right fan status
395 return seq_printf(seq
, "%s %s %s %d %d %d %d %d %d %d\n",
398 dmi_get_system_info(DMI_PRODUCT_SERIAL
) ? : "N/A",
400 left_fan
, right_fan
, left_speed
, right_speed
,
404 static int i8k_open_fs(struct inode
*inode
, struct file
*file
)
406 return single_open(file
, i8k_proc_show
, NULL
);
409 static struct dmi_system_id __initdata i8k_dmi_table
[] = {
411 .ident
= "Dell Inspiron",
413 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer"),
414 DMI_MATCH(DMI_PRODUCT_NAME
, "Inspiron"),
418 .ident
= "Dell Latitude",
420 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer"),
421 DMI_MATCH(DMI_PRODUCT_NAME
, "Latitude"),
428 * Probe for the presence of a supported laptop.
430 static int __init
i8k_probe(void)
436 * Get DMI information
438 if (!dmi_check_system(i8k_dmi_table
)) {
439 if (!ignore_dmi
&& !force
)
442 printk(KERN_INFO
"i8k: not running on a supported Dell system.\n");
443 printk(KERN_INFO
"i8k: vendor=%s, model=%s, version=%s\n",
444 i8k_get_dmi_data(DMI_SYS_VENDOR
),
445 i8k_get_dmi_data(DMI_PRODUCT_NAME
),
446 i8k_get_dmi_data(DMI_BIOS_VERSION
));
449 strlcpy(bios_version
, i8k_get_dmi_data(DMI_BIOS_VERSION
), sizeof(bios_version
));
452 * Get SMM Dell signature
454 if (i8k_get_dell_signature() != 0) {
455 printk(KERN_ERR
"i8k: unable to get SMM Dell signature\n");
461 * Get SMM BIOS version.
463 version
= i8k_get_bios_version();
465 printk(KERN_WARNING
"i8k: unable to get SMM BIOS version\n");
467 buff
[0] = (version
>> 16) & 0xff;
468 buff
[1] = (version
>> 8) & 0xff;
469 buff
[2] = (version
) & 0xff;
472 * If DMI BIOS version is unknown use SMM BIOS version.
474 if (!dmi_get_system_info(DMI_BIOS_VERSION
))
475 strlcpy(bios_version
, buff
, sizeof(bios_version
));
478 * Check if the two versions match.
480 if (strncmp(buff
, bios_version
, sizeof(bios_version
)) != 0)
481 printk(KERN_WARNING
"i8k: BIOS version mismatch: %s != %s\n",
488 static int __init
i8k_init(void)
490 struct proc_dir_entry
*proc_i8k
;
492 /* Are we running on an supported laptop? */
496 /* Register the proc entry */
497 proc_i8k
= create_proc_entry("i8k", 0, NULL
);
501 proc_i8k
->proc_fops
= &i8k_fops
;
502 proc_i8k
->owner
= THIS_MODULE
;
505 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
511 static void __exit
i8k_exit(void)
513 remove_proc_entry("i8k", NULL
);
516 module_init(i8k_init
);
517 module_exit(i8k_exit
);