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/apm_bios.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 #define DELL_SIGNATURE "Dell Computer"
57 static char *supported_models[] = {
63 static char system_vendor[48] = "?";
64 static char product_name [48] = "?";
65 static char bios_version [4] = "?";
66 static char serial_number[16] = "?";
69 static int restricted = 0;
70 static int power_status = 0;
72 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
73 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
74 MODULE_LICENSE("GPL");
75 MODULE_PARM(force, "i");
76 MODULE_PARM(restricted, "i");
77 MODULE_PARM(power_status, "i");
78 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
79 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
80 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
82 static ssize_t i8k_read(struct file *, char *, size_t, loff_t *);
83 static int i8k_ioctl(struct inode *, struct file *, unsigned int,
86 static struct file_operations i8k_fops = {
93 unsigned int ebx __attribute__ ((packed));
94 unsigned int ecx __attribute__ ((packed));
95 unsigned int edx __attribute__ ((packed));
96 unsigned int esi __attribute__ ((packed));
97 unsigned int edi __attribute__ ((packed));
107 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
109 static int i8k_smm(SMMRegisters *regs)
114 asm("pushl %%eax\n\t" \
115 "movl 0(%%eax),%%edx\n\t" \
117 "movl 4(%%eax),%%ebx\n\t" \
118 "movl 8(%%eax),%%ecx\n\t" \
119 "movl 12(%%eax),%%edx\n\t" \
120 "movl 16(%%eax),%%esi\n\t" \
121 "movl 20(%%eax),%%edi\n\t" \
123 "out %%al,$0xb2\n\t" \
124 "out %%al,$0x84\n\t" \
125 "xchgl %%eax,(%%esp)\n\t"
126 "movl %%ebx,4(%%eax)\n\t" \
127 "movl %%ecx,8(%%eax)\n\t" \
128 "movl %%edx,12(%%eax)\n\t" \
129 "movl %%esi,16(%%eax)\n\t" \
130 "movl %%edi,20(%%eax)\n\t" \
132 "movl %%edx,0(%%eax)\n\t" \
134 "shrl $8,%%eax\n\t" \
138 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
140 if ((rc != 0) || ((regs->eax & 0xffff) == 0xffff) || (regs->eax == eax)) {
148 * Read the bios version. Return the version as an integer corresponding
149 * to the ascii value, for example "A17" is returned as 0x00413137.
151 static int i8k_get_bios_version(void)
153 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
156 regs.eax = I8K_SMM_BIOS_VERSION;
157 if ((rc=i8k_smm(®s)) < 0) {
165 * Read the machine id.
167 static int i8k_get_serial_number(unsigned char *buff)
169 strlcpy(buff, serial_number, sizeof(serial_number));
174 * Read the Fn key status.
176 static int i8k_get_fn_status(void)
178 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
181 regs.eax = I8K_SMM_FN_STATUS;
182 if ((rc=i8k_smm(®s)) < 0) {
186 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
199 * Read the power status.
201 static int i8k_get_power_status(void)
203 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
206 regs.eax = I8K_SMM_POWER_STATUS;
207 if ((rc=i8k_smm(®s)) < 0) {
211 switch (regs.eax & 0xff) {
220 * Read the fan status.
222 static int i8k_get_fan_status(int fan)
224 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
227 regs.eax = I8K_SMM_GET_FAN;
228 regs.ebx = fan & 0xff;
229 if ((rc=i8k_smm(®s)) < 0) {
233 return (regs.eax & 0xff);
237 * Read the fan speed in RPM.
239 static int i8k_get_fan_speed(int fan)
241 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
244 regs.eax = I8K_SMM_GET_SPEED;
245 regs.ebx = fan & 0xff;
246 if ((rc=i8k_smm(®s)) < 0) {
250 return (regs.eax & 0xffff) * I8K_FAN_MULT;
254 * Set the fan speed (off, low, high). Returns the new fan status.
256 static int i8k_set_fan(int fan, int speed)
258 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
261 speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
263 regs.eax = I8K_SMM_SET_FAN;
264 regs.ebx = (fan & 0xff) | (speed << 8);
265 if ((rc=i8k_smm(®s)) < 0) {
269 return (i8k_get_fan_status(fan));
273 * Read the cpu temperature.
275 static int i8k_get_cpu_temp(void)
277 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
281 #ifdef I8K_TEMPERATURE_BUG
285 regs.eax = I8K_SMM_GET_TEMP;
286 if ((rc=i8k_smm(®s)) < 0) {
289 temp = regs.eax & 0xff;
291 #ifdef I8K_TEMPERATURE_BUG
293 * Sometimes the temperature sensor returns 0x99, which is out of range.
294 * In this case we return (once) the previous cached value. For example:
295 # 1003655137 00000058 00005a4b
296 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
297 # 1003655139 00000054 00005c52
299 if (temp > I8K_MAX_TEMP) {
310 static int i8k_get_dell_signature(void)
312 SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
315 regs.eax = I8K_SMM_GET_DELL_SIG;
316 if ((rc=i8k_smm(®s)) < 0) {
320 if ((regs.eax == 1145651527) && (regs.edx == 1145392204)) {
327 static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
332 unsigned char buff[16];
339 case I8K_BIOS_VERSION:
340 val = i8k_get_bios_version();
345 val = i8k_get_serial_number(buff);
349 val = i8k_get_fn_status();
352 case I8K_POWER_STATUS:
353 val = i8k_get_power_status();
357 val = i8k_get_cpu_temp();
361 if (copy_from_user(&val, (int *)arg, sizeof(int))) {
364 val = i8k_get_fan_speed(val);
368 if (copy_from_user(&val, (int *)arg, sizeof(int))) {
371 val = i8k_get_fan_status(val);
375 if (restricted && !capable(CAP_SYS_ADMIN)) {
378 if (copy_from_user(&val, (int *)arg, sizeof(int))) {
381 if (copy_from_user(&speed, (int *)arg+1, sizeof(int))) {
384 val = i8k_set_fan(val, speed);
396 case I8K_BIOS_VERSION:
397 if (copy_to_user((int *)arg, &val, 4)) {
402 if (copy_to_user((int *)arg, buff, 16)) {
407 if (copy_to_user((int *)arg, &val, sizeof(int))) {
417 * Print the information for /proc/i8k.
419 static int i8k_get_info(char *buffer, char **start, off_t fpos, int length)
421 int n, fn_key, cpu_temp, ac_power;
422 int left_fan, right_fan, left_speed, right_speed;
424 cpu_temp = i8k_get_cpu_temp(); /* 11100 µs */
425 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
426 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
427 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
428 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
429 fn_key = i8k_get_fn_status(); /* 750 µs */
431 ac_power = i8k_get_power_status(); /* 14700 µs */
439 * 1) Format version (this will change if format changes)
444 * 6) Right fan status
450 n = sprintf(buffer, "%s %s %s %d %d %d %d %d %d %d\n",
465 static ssize_t i8k_read(struct file *f, char *buffer, size_t len, loff_t *fpos)
470 n = i8k_get_info(info, NULL, 0, 128);
479 if ((*fpos + len) >= n) {
483 if (copy_to_user(buffer, info, len) != 0) {
491 static char* __init string_trim(char *s, int size)
496 if ((len = strlen(s)) > size) {
500 for (p=s+len-1; len && (*p==' '); len--,p--) {
507 /* DMI code, stolen from arch/i386/kernel/dmi_scan.c */
510 * |<-- dmi->length -->|
512 * |dmi header s=N | string1,\0, ..., stringN,\0, ..., \0
514 * +-----------------------+
516 static char* __init dmi_string(DMIHeader *dmi, u8 s)
525 p = (u8 *)dmi + dmi->length;
535 static void __init dmi_decode(DMIHeader *dmi)
537 u8 *data = (u8 *) dmi;
542 printk("%08x ", (int)data);
543 for (i=0; i<data[1] && i<64; i++) {
544 printk("%02x ", data[i]);
550 case 0: /* BIOS Information */
551 p = dmi_string(dmi,data[5]);
553 strlcpy(bios_version, p, sizeof(bios_version));
554 string_trim(bios_version, sizeof(bios_version));
557 case 1: /* System Information */
558 p = dmi_string(dmi,data[4]);
560 strlcpy(system_vendor, p, sizeof(system_vendor));
561 string_trim(system_vendor, sizeof(system_vendor));
563 p = dmi_string(dmi,data[5]);
565 strlcpy(product_name, p, sizeof(product_name));
566 string_trim(product_name, sizeof(product_name));
568 p = dmi_string(dmi,data[7]);
570 strlcpy(serial_number, p, sizeof(serial_number));
571 string_trim(serial_number, sizeof(serial_number));
577 static int __init dmi_table(u32 base, int len, int num, void (*fn)(DMIHeader*))
584 buf = ioremap(base, len);
591 * Stop when we see al the items the table claimed to have
592 * or we run off the end of the table (also happens)
594 while ((i<num) && ((data-buf) < len)) {
595 dmi = (DMIHeader *)data;
597 * Avoid misparsing crud if the length of the last
600 if ((data-buf+dmi->length) >= len) {
606 * Don't go off the end of the data if there is
607 * stuff looking like string fill past the end
609 while (((data-buf) < len) && (*data || data[1])) {
620 static int __init dmi_iterate(void (*decode)(DMIHeader *))
622 unsigned char buf[20];
623 long fp = 0x000e0000L;
626 while (fp < 0x000fffffL) {
628 isa_memcpy_fromio(buf, fp, 20);
629 if (memcmp(buf, "_DMI_", 5)==0) {
630 u16 num = buf[13]<<8 | buf[12];
631 u16 len = buf [7]<<8 | buf [6];
632 u32 base = buf[11]<<24 | buf[10]<<16 | buf[9]<<8 | buf[8];
634 printk(KERN_INFO "DMI %d.%d present.\n",
635 buf[14]>>4, buf[14]&0x0F);
636 printk(KERN_INFO "%d structures occupying %d bytes.\n",
637 buf[13]<<8 | buf[12],
638 buf [7]<<8 | buf[6]);
639 printk(KERN_INFO "DMI table at 0x%08X.\n",
640 buf[11]<<24 | buf[10]<<16 | buf[9]<<8 | buf[8]);
642 if (dmi_table(base, len, num, decode)==0) {
649 /* end of DMI code */
652 * Get DMI information.
654 static int __init i8k_dmi_probe(void)
658 if (dmi_iterate(dmi_decode) != 0) {
659 printk(KERN_INFO "i8k: unable to get DMI information\n");
663 if (strncmp(system_vendor,DELL_SIGNATURE,strlen(DELL_SIGNATURE)) != 0) {
664 printk(KERN_INFO "i8k: not running on a Dell system\n");
668 for (p=supported_models; ; p++) {
670 printk(KERN_INFO "i8k: unsupported model: %s\n", product_name);
673 if (strncmp(product_name,*p,strlen(*p)) == 0) {
682 * Probe for the presence of a supported laptop.
684 static int __init i8k_probe(void)
691 * Get DMI information
693 if (i8k_dmi_probe() != 0) {
694 printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
695 system_vendor, product_name, bios_version);
699 * Get SMM Dell signature
701 if (i8k_get_dell_signature() != 0) {
702 printk(KERN_INFO "i8k: unable to get SMM Dell signature\n");
708 * Get SMM BIOS version.
710 version = i8k_get_bios_version();
712 printk(KERN_INFO "i8k: unable to get SMM BIOS version\n");
715 buff[0] = (version >> 16) & 0xff;
716 buff[1] = (version >> 8) & 0xff;
717 buff[2] = (version) & 0xff;
720 * If DMI BIOS version is unknown use SMM BIOS version.
722 if (bios_version[0] == '?') {
723 strcpy(bios_version, buff);
726 * Check if the two versions match.
728 if (strncmp(buff,bios_version,sizeof(bios_version)) != 0) {
729 printk(KERN_INFO "i8k: BIOS version mismatch: %s != %s\n",
734 if (!smm_found && !force) {
744 int __init i8k_init(void)
746 struct proc_dir_entry *proc_i8k;
748 /* Are we running on an supported laptop? */
749 if (i8k_probe() != 0) {
753 /* Register the proc entry */
754 proc_i8k = create_proc_info_entry("i8k", 0, NULL, i8k_get_info);
758 proc_i8k->proc_fops = &i8k_fops;
759 proc_i8k->owner = THIS_MODULE;
762 "Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
769 int init_module(void)
774 void cleanup_module(void)
776 /* Remove the proc entry */
777 remove_proc_entry("i8k", NULL);
779 printk(KERN_INFO "i8k: module unloaded\n");