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 <linux/mutex.h>
27 #include <asm/uaccess.h>
30 #include <linux/i8k.h>
32 #define I8K_VERSION "1.14 21/02/2005"
34 #define I8K_SMM_FN_STATUS 0x0025
35 #define I8K_SMM_POWER_STATUS 0x0069
36 #define I8K_SMM_SET_FAN 0x01a3
37 #define I8K_SMM_GET_FAN 0x00a3
38 #define I8K_SMM_GET_SPEED 0x02a3
39 #define I8K_SMM_GET_TEMP 0x10a3
40 #define I8K_SMM_GET_DELL_SIG1 0xfea3
41 #define I8K_SMM_GET_DELL_SIG2 0xffa3
42 #define I8K_SMM_BIOS_VERSION 0x00a6
44 #define I8K_FAN_MULT 30
45 #define I8K_MAX_TEMP 127
47 #define I8K_FN_NONE 0x00
48 #define I8K_FN_UP 0x01
49 #define I8K_FN_DOWN 0x02
50 #define I8K_FN_MUTE 0x04
51 #define I8K_FN_MASK 0x07
52 #define I8K_FN_SHIFT 8
54 #define I8K_POWER_AC 0x05
55 #define I8K_POWER_BATTERY 0x01
57 #define I8K_TEMPERATURE_BUG 1
59 static DEFINE_MUTEX(i8k_mutex);
60 static char bios_version[4];
62 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
63 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
64 MODULE_LICENSE("GPL");
67 module_param(force, bool, 0);
68 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
70 static int ignore_dmi;
71 module_param(ignore_dmi, bool, 0);
72 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
74 static int restricted;
75 module_param(restricted, bool, 0);
76 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
78 static int power_status;
79 module_param(power_status, bool, 0600);
80 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
82 static int fan_mult = I8K_FAN_MULT;
83 module_param(fan_mult, int, 0);
84 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
86 static int i8k_open_fs(struct inode *inode, struct file *file);
87 static long i8k_ioctl(struct file *, unsigned int, unsigned long);
89 static const struct file_operations i8k_fops = {
94 .release = single_release,
95 .unlocked_ioctl = i8k_ioctl,
100 unsigned int ebx __attribute__ ((packed));
101 unsigned int ecx __attribute__ ((packed));
102 unsigned int edx __attribute__ ((packed));
103 unsigned int esi __attribute__ ((packed));
104 unsigned int edi __attribute__ ((packed));
107 static inline const char *i8k_get_dmi_data(int field)
109 const char *dmi_data = dmi_get_system_info(field);
111 return dmi_data && *dmi_data ? dmi_data : "?";
115 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
117 static int i8k_smm(struct smm_regs *regs)
122 #if defined(CONFIG_X86_64)
123 asm("pushq %%rax\n\t"
124 "movl 0(%%rax),%%edx\n\t"
126 "movl 4(%%rax),%%ebx\n\t"
127 "movl 8(%%rax),%%ecx\n\t"
128 "movl 12(%%rax),%%edx\n\t"
129 "movl 16(%%rax),%%esi\n\t"
130 "movl 20(%%rax),%%edi\n\t"
134 "xchgq %%rax,(%%rsp)\n\t"
135 "movl %%ebx,4(%%rax)\n\t"
136 "movl %%ecx,8(%%rax)\n\t"
137 "movl %%edx,12(%%rax)\n\t"
138 "movl %%esi,16(%%rax)\n\t"
139 "movl %%edi,20(%%rax)\n\t"
141 "movl %%edx,0(%%rax)\n\t"
147 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
149 asm("pushl %%eax\n\t"
150 "movl 0(%%eax),%%edx\n\t"
152 "movl 4(%%eax),%%ebx\n\t"
153 "movl 8(%%eax),%%ecx\n\t"
154 "movl 12(%%eax),%%edx\n\t"
155 "movl 16(%%eax),%%esi\n\t"
156 "movl 20(%%eax),%%edi\n\t"
160 "xchgl %%eax,(%%esp)\n\t"
161 "movl %%ebx,4(%%eax)\n\t"
162 "movl %%ecx,8(%%eax)\n\t"
163 "movl %%edx,12(%%eax)\n\t"
164 "movl %%esi,16(%%eax)\n\t"
165 "movl %%edi,20(%%eax)\n\t"
167 "movl %%edx,0(%%eax)\n\t"
170 "andl $1,%%eax\n":"=a"(rc)
172 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
174 if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
181 * Read the bios version. Return the version as an integer corresponding
182 * to the ascii value, for example "A17" is returned as 0x00413137.
184 static int i8k_get_bios_version(void)
186 struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
188 return i8k_smm(®s) ? : regs.eax;
192 * Read the Fn key status.
194 static int i8k_get_fn_status(void)
196 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
199 if ((rc = i8k_smm(®s)) < 0)
202 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
215 * Read the power status.
217 static int i8k_get_power_status(void)
219 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
222 if ((rc = i8k_smm(®s)) < 0)
225 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
229 * Read the fan status.
231 static int i8k_get_fan_status(int fan)
233 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
235 regs.ebx = fan & 0xff;
236 return i8k_smm(®s) ? : regs.eax & 0xff;
240 * Read the fan speed in RPM.
242 static int i8k_get_fan_speed(int fan)
244 struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
246 regs.ebx = fan & 0xff;
247 return i8k_smm(®s) ? : (regs.eax & 0xffff) * fan_mult;
251 * Set the fan speed (off, low, high). Returns the new fan status.
253 static int i8k_set_fan(int fan, int speed)
255 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
257 speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
258 regs.ebx = (fan & 0xff) | (speed << 8);
260 return i8k_smm(®s) ? : i8k_get_fan_status(fan);
264 * Read the cpu temperature.
266 static int i8k_get_temp(int sensor)
268 struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
272 #ifdef I8K_TEMPERATURE_BUG
275 regs.ebx = sensor & 0xff;
276 if ((rc = i8k_smm(®s)) < 0)
279 temp = regs.eax & 0xff;
281 #ifdef I8K_TEMPERATURE_BUG
283 * Sometimes the temperature sensor returns 0x99, which is out of range.
284 * In this case we return (once) the previous cached value. For example:
285 # 1003655137 00000058 00005a4b
286 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
287 # 1003655139 00000054 00005c52
289 if (temp > I8K_MAX_TEMP) {
300 static int i8k_get_dell_signature(int req_fn)
302 struct smm_regs regs = { .eax = req_fn, };
305 if ((rc = i8k_smm(®s)) < 0)
308 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
312 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
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_temp(0);
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);
379 case I8K_BIOS_VERSION:
380 if (copy_to_user(argp, &val, 4))
385 if (copy_to_user(argp, buff, 16))
390 if (copy_to_user(argp, &val, sizeof(int)))
399 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
403 mutex_lock(&i8k_mutex);
404 ret = i8k_ioctl_unlocked(fp, cmd, arg);
405 mutex_unlock(&i8k_mutex);
411 * Print the information for /proc/i8k.
413 static int i8k_proc_show(struct seq_file *seq, void *offset)
415 int fn_key, cpu_temp, ac_power;
416 int left_fan, right_fan, left_speed, right_speed;
418 cpu_temp = i8k_get_temp(0); /* 11100 µs */
419 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
420 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
421 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
422 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
423 fn_key = i8k_get_fn_status(); /* 750 µs */
425 ac_power = i8k_get_power_status(); /* 14700 µs */
432 * 1) Format version (this will change if format changes)
437 * 6) Right fan status
443 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
446 i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
448 left_fan, right_fan, left_speed, right_speed,
452 static int i8k_open_fs(struct inode *inode, struct file *file)
454 return single_open(file, i8k_proc_show, NULL);
457 static struct dmi_system_id __initdata i8k_dmi_table[] = {
459 .ident = "Dell Inspiron",
461 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
462 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
466 .ident = "Dell Latitude",
468 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
469 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
473 .ident = "Dell Inspiron 2",
475 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
476 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
480 .ident = "Dell Latitude 2",
482 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
483 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
486 { /* UK Inspiron 6400 */
487 .ident = "Dell Inspiron 3",
489 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
490 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
494 .ident = "Dell Inspiron 3",
496 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
497 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
501 .ident = "Dell Precision",
503 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
504 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
508 .ident = "Dell Vostro",
510 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
511 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
518 * Probe for the presence of a supported laptop.
520 static int __init i8k_probe(void)
526 * Get DMI information
528 if (!dmi_check_system(i8k_dmi_table)) {
529 if (!ignore_dmi && !force)
532 printk(KERN_INFO "i8k: not running on a supported Dell system.\n");
533 printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
534 i8k_get_dmi_data(DMI_SYS_VENDOR),
535 i8k_get_dmi_data(DMI_PRODUCT_NAME),
536 i8k_get_dmi_data(DMI_BIOS_VERSION));
539 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION), sizeof(bios_version));
542 * Get SMM Dell signature
544 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
545 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
546 printk(KERN_ERR "i8k: unable to get SMM Dell signature\n");
552 * Get SMM BIOS version.
554 version = i8k_get_bios_version();
556 printk(KERN_WARNING "i8k: unable to get SMM BIOS version\n");
558 buff[0] = (version >> 16) & 0xff;
559 buff[1] = (version >> 8) & 0xff;
560 buff[2] = (version) & 0xff;
563 * If DMI BIOS version is unknown use SMM BIOS version.
565 if (!dmi_get_system_info(DMI_BIOS_VERSION))
566 strlcpy(bios_version, buff, sizeof(bios_version));
569 * Check if the two versions match.
571 if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
572 printk(KERN_WARNING "i8k: BIOS version mismatch: %s != %s\n",
579 static int __init i8k_init(void)
581 struct proc_dir_entry *proc_i8k;
583 /* Are we running on an supported laptop? */
587 /* Register the proc entry */
588 proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
593 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
599 static void __exit i8k_exit(void)
601 remove_proc_entry("i8k", NULL);
604 module_init(i8k_init);
605 module_exit(i8k_exit);