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(SMMRegisters * 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)) {
145 * Read the bios version. Return the version as an integer corresponding
146 * to the ascii value, for example "A17" is returned as 0x00413137.
148 static int i8k_get_bios_version(void)
150 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
153 regs.eax = I8K_SMM_BIOS_VERSION;
154 if ((rc = i8k_smm(®s)) < 0) {
162 * Read the Fn key status.
164 static int i8k_get_fn_status(void)
166 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
169 regs.eax = I8K_SMM_FN_STATUS;
170 if ((rc = i8k_smm(®s)) < 0) {
174 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
187 * Read the power status.
189 static int i8k_get_power_status(void)
191 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
194 regs.eax = I8K_SMM_POWER_STATUS;
195 if ((rc = i8k_smm(®s)) < 0) {
199 switch (regs.eax & 0xff) {
208 * Read the fan status.
210 static int i8k_get_fan_status(int fan)
212 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
215 regs.eax = I8K_SMM_GET_FAN;
216 regs.ebx = fan & 0xff;
217 if ((rc = i8k_smm(®s)) < 0) {
221 return (regs.eax & 0xff);
225 * Read the fan speed in RPM.
227 static int i8k_get_fan_speed(int fan)
229 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
232 regs.eax = I8K_SMM_GET_SPEED;
233 regs.ebx = fan & 0xff;
234 if ((rc = i8k_smm(®s)) < 0) {
238 return (regs.eax & 0xffff) * I8K_FAN_MULT;
242 * Set the fan speed (off, low, high). Returns the new fan status.
244 static int i8k_set_fan(int fan, int speed)
246 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
249 speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
251 regs.eax = I8K_SMM_SET_FAN;
252 regs.ebx = (fan & 0xff) | (speed << 8);
253 if ((rc = i8k_smm(®s)) < 0) {
257 return (i8k_get_fan_status(fan));
261 * Read the cpu temperature.
263 static int i8k_get_cpu_temp(void)
265 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
269 #ifdef I8K_TEMPERATURE_BUG
273 regs.eax = I8K_SMM_GET_TEMP;
274 if ((rc = i8k_smm(®s)) < 0) {
277 temp = regs.eax & 0xff;
279 #ifdef I8K_TEMPERATURE_BUG
281 * Sometimes the temperature sensor returns 0x99, which is out of range.
282 * In this case we return (once) the previous cached value. For example:
283 # 1003655137 00000058 00005a4b
284 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
285 # 1003655139 00000054 00005c52
287 if (temp > I8K_MAX_TEMP) {
298 static int i8k_get_dell_signature(void)
300 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
303 regs.eax = I8K_SMM_GET_DELL_SIG;
304 if ((rc = i8k_smm(®s)) < 0) {
308 if ((regs.eax == 1145651527) && (regs.edx == 1145392204)) {
315 static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
320 unsigned char buff[16];
321 int __user *argp = (int __user *)arg;
327 case I8K_BIOS_VERSION:
328 val = i8k_get_bios_version();
333 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL), sizeof(buff));
337 val = i8k_get_fn_status();
340 case I8K_POWER_STATUS:
341 val = i8k_get_power_status();
345 val = i8k_get_cpu_temp();
349 if (copy_from_user(&val, argp, sizeof(int))) {
352 val = i8k_get_fan_speed(val);
356 if (copy_from_user(&val, argp, sizeof(int))) {
359 val = i8k_get_fan_status(val);
363 if (restricted && !capable(CAP_SYS_ADMIN)) {
366 if (copy_from_user(&val, argp, sizeof(int))) {
369 if (copy_from_user(&speed, argp + 1, sizeof(int))) {
372 val = i8k_set_fan(val, speed);
384 case I8K_BIOS_VERSION:
385 if (copy_to_user(argp, &val, 4)) {
390 if (copy_to_user(argp, buff, 16)) {
395 if (copy_to_user(argp, &val, sizeof(int))) {
405 * Print the information for /proc/i8k.
407 static int i8k_proc_show(struct seq_file *seq, void *offset)
409 int fn_key, cpu_temp, ac_power;
410 int left_fan, right_fan, left_speed, right_speed;
412 cpu_temp = i8k_get_cpu_temp(); /* 11100 µs */
413 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
414 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
415 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
416 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
417 fn_key = i8k_get_fn_status(); /* 750 µs */
419 ac_power = i8k_get_power_status(); /* 14700 µs */
427 * 1) Format version (this will change if format changes)
432 * 6) Right fan status
438 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
441 dmi_get_system_info(DMI_PRODUCT_SERIAL) ? : "N/A",
443 left_fan, right_fan, left_speed, right_speed,
447 static int i8k_open_fs(struct inode *inode, struct file *file)
449 return single_open(file, i8k_proc_show, NULL);
452 static struct dmi_system_id __initdata i8k_dmi_table[] = {
454 .ident = "Dell Inspiron",
456 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
457 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
461 .ident = "Dell Latitude",
463 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
464 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
471 * Probe for the presence of a supported laptop.
473 static int __init i8k_probe(void)
479 * Get DMI information
481 if (!dmi_check_system(i8k_dmi_table)) {
482 if (!ignore_dmi && !force)
485 printk(KERN_INFO "i8k: not running on a supported Dell system.\n");
486 printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
487 i8k_get_dmi_data(DMI_SYS_VENDOR),
488 i8k_get_dmi_data(DMI_PRODUCT_NAME),
489 i8k_get_dmi_data(DMI_BIOS_VERSION));
492 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION), sizeof(bios_version));
495 * Get SMM Dell signature
497 if (i8k_get_dell_signature() != 0) {
498 printk(KERN_ERR "i8k: unable to get SMM Dell signature\n");
504 * Get SMM BIOS version.
506 version = i8k_get_bios_version();
508 printk(KERN_WARNING "i8k: unable to get SMM BIOS version\n");
510 buff[0] = (version >> 16) & 0xff;
511 buff[1] = (version >> 8) & 0xff;
512 buff[2] = (version) & 0xff;
515 * If DMI BIOS version is unknown use SMM BIOS version.
517 if (!dmi_get_system_info(DMI_BIOS_VERSION))
518 strlcpy(bios_version, buff, sizeof(bios_version));
521 * Check if the two versions match.
523 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
524 printk(KERN_WARNING "i8k: BIOS version mismatch: %s != %s\n",
534 int __init i8k_init(void)
536 struct proc_dir_entry *proc_i8k;
538 /* Are we running on an supported laptop? */
542 /* Register the proc entry */
543 proc_i8k = create_proc_entry("i8k", 0, NULL);
547 proc_i8k->proc_fops = &i8k_fops;
548 proc_i8k->owner = THIS_MODULE;
551 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
558 int init_module(void)
563 void cleanup_module(void)
565 /* Remove the proc entry */
566 remove_proc_entry("i8k", NULL);
568 printk(KERN_INFO "i8k: module unloaded\n");