/*
* i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
* See http://www.debian.org/~dz/i8k/ for more information
* and for latest version of this driver.
*
* Copyright (C) 2001 Massimo Dal Zotto <dz@debian.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/apm_bios.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/i8k.h>
#define I8K_VERSION "1.13 14/05/2002"
#define I8K_SMM_FN_STATUS 0x0025
#define I8K_SMM_POWER_STATUS 0x0069
#define I8K_SMM_SET_FAN 0x01a3
#define I8K_SMM_GET_FAN 0x00a3
#define I8K_SMM_GET_SPEED 0x02a3
#define I8K_SMM_GET_TEMP 0x10a3
#define I8K_SMM_GET_DELL_SIG 0xffa3
#define I8K_SMM_BIOS_VERSION 0x00a6
#define I8K_FAN_MULT 30
#define I8K_MAX_TEMP 127
#define I8K_FN_NONE 0x00
#define I8K_FN_UP 0x01
#define I8K_FN_DOWN 0x02
#define I8K_FN_MUTE 0x04
#define I8K_FN_MASK 0x07
#define I8K_FN_SHIFT 8
#define I8K_POWER_AC 0x05
#define I8K_POWER_BATTERY 0x01
#define I8K_TEMPERATURE_BUG 1
#define DELL_SIGNATURE "Dell Computer"
static char *supported_models[] = {
"Inspiron",
"Latitude",
NULL
};
static char system_vendor[48] = "?";
static char product_name [48] = "?";
static char bios_version [4] = "?";
static char serial_number[16] = "?";
MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
MODULE_LICENSE("GPL");
static int force;
module_param(force, bool, 0);
MODULE_PARM_DESC(force, "Force loading without checking for supported models");
static int restricted;
module_param(restricted, bool, 0);
MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
static int power_status;
module_param(power_status, bool, 0600);
MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
static ssize_t i8k_read(struct file *, char __user *, size_t, loff_t *);
static int i8k_ioctl(struct inode *, struct file *, unsigned int,
unsigned long);
static struct file_operations i8k_fops = {
.read = i8k_read,
.ioctl = i8k_ioctl,
};
typedef struct {
unsigned int eax;
unsigned int ebx __attribute__ ((packed));
unsigned int ecx __attribute__ ((packed));
unsigned int edx __attribute__ ((packed));
unsigned int esi __attribute__ ((packed));
unsigned int edi __attribute__ ((packed));
} SMMRegisters;
typedef struct {
u8 type;
u8 length;
u16 handle;
} DMIHeader;
/*
* Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
*/
static int i8k_smm(SMMRegisters *regs)
{
int rc;
int eax = regs->eax;
asm("pushl %%eax\n\t" \
"movl 0(%%eax),%%edx\n\t" \
"push %%edx\n\t" \
"movl 4(%%eax),%%ebx\n\t" \
"movl 8(%%eax),%%ecx\n\t" \
"movl 12(%%eax),%%edx\n\t" \
"movl 16(%%eax),%%esi\n\t" \
"movl 20(%%eax),%%edi\n\t" \
"popl %%eax\n\t" \
"out %%al,$0xb2\n\t" \
"out %%al,$0x84\n\t" \
"xchgl %%eax,(%%esp)\n\t"
"movl %%ebx,4(%%eax)\n\t" \
"movl %%ecx,8(%%eax)\n\t" \
"movl %%edx,12(%%eax)\n\t" \
"movl %%esi,16(%%eax)\n\t" \
"movl %%edi,20(%%eax)\n\t" \
"popl %%edx\n\t" \
"movl %%edx,0(%%eax)\n\t" \
"lahf\n\t" \
"shrl $8,%%eax\n\t" \
"andl $1,%%eax\n" \
: "=a" (rc)
: "a" (regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
if ((rc != 0) || ((regs->eax & 0xffff) == 0xffff) || (regs->eax == eax)) {
return -EINVAL;
}
return 0;
}
/*
* Read the bios version. Return the version as an integer corresponding
* to the ascii value, for example "A17" is returned as 0x00413137.
*/
static int i8k_get_bios_version(void)
{
SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
int rc;
regs.eax = I8K_SMM_BIOS_VERSION;
if ((rc=i8k_smm(®s)) < 0) {
return rc;
}
return regs.eax;
}
/*
* Read the machine id.
*/
static int i8k_get_serial_number(unsigned char *buff)
{
strlcpy(buff, serial_number, sizeof(serial_number));
return 0;
}
/*
* Read the Fn key status.
*/
static int i8k_get_fn_status(void)
{
SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
int rc;
regs.eax = I8K_SMM_FN_STATUS;
if ((rc=i8k_smm(®s)) < 0) {
return rc;
}
switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
case I8K_FN_UP:
return I8K_VOL_UP;
case I8K_FN_DOWN:
return I8K_VOL_DOWN;
case I8K_FN_MUTE:
return I8K_VOL_MUTE;
default:
return 0;
}
}
/*
* Read the power status.
*/
static int i8k_get_power_status(void)
{
SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
int rc;
regs.eax = I8K_SMM_POWER_STATUS;
if ((rc=i8k_smm(®s)) < 0) {
return rc;
}
switch (regs.eax & 0xff) {
case I8K_POWER_AC:
return I8K_AC;
default:
return I8K_BATTERY;
}
}
/*
* Read the fan status.
*/
static int i8k_get_fan_status(int fan)
{
SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
int rc;
regs.eax = I8K_SMM_GET_FAN;
regs.ebx = fan & 0xff;
if ((rc=i8k_smm(®s)) < 0) {
return rc;
}
return (regs.eax & 0xff);
}
/*
* Read the fan speed in RPM.
*/
static int i8k_get_fan_speed(int fan)
{
SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
int rc;
regs.eax = I8K_SMM_GET_SPEED;
regs.ebx = fan & 0xff;
if ((rc=i8k_smm(®s)) < 0) {
return rc;
}
return (regs.eax & 0xffff) * I8K_FAN_MULT;
}
/*
* Set the fan speed (off, low, high). Returns the new fan status.
*/
static int i8k_set_fan(int fan, int speed)
{
SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
int rc;
speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
regs.eax = I8K_SMM_SET_FAN;
regs.ebx = (fan & 0xff) | (speed << 8);
if ((rc=i8k_smm(®s)) < 0) {
return rc;
}
return (i8k_get_fan_status(fan));
}
/*
* Read the cpu temperature.
*/
static int i8k_get_cpu_temp(void)
{
SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
int rc;
int temp;
#ifdef I8K_TEMPERATURE_BUG
static int prev = 0;
#endif
regs.eax = I8K_SMM_GET_TEMP;
if ((rc=i8k_smm(®s)) < 0) {
return rc;
}
temp = regs.eax & 0xff;
#ifdef I8K_TEMPERATURE_BUG
/*
* Sometimes the temperature sensor returns 0x99, which is out of range.
* In this case we return (once) the previous cached value. For example:
# 1003655137 00000058 00005a4b
# 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
# 1003655139 00000054 00005c52
*/
if (temp > I8K_MAX_TEMP) {
temp = prev;
prev = I8K_MAX_TEMP;
} else {
prev = temp;
}
#endif
return temp;
}
static int i8k_get_dell_signature(void)
{
SMMRegisters regs = { 0, 0, 0, 0, 0, 0 };
int rc;
regs.eax = I8K_SMM_GET_DELL_SIG;
if ((rc=i8k_smm(®s)) < 0) {
return rc;
}
if ((regs.eax == 1145651527) && (regs.edx == 1145392204)) {
return 0;
} else {
return -1;
}
}
static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
unsigned long arg)
{
int val;
int speed;
unsigned char buff[16];
int __user *argp = (int __user *)arg;
if (!argp)
return -EINVAL;
switch (cmd) {
case I8K_BIOS_VERSION:
val = i8k_get_bios_version();
break;
case I8K_MACHINE_ID:
memset(buff, 0, 16);
val = i8k_get_serial_number(buff);
break;
case I8K_FN_STATUS:
val = i8k_get_fn_status();
break;
case I8K_POWER_STATUS:
val = i8k_get_power_status();
break;
case I8K_GET_TEMP:
val = i8k_get_cpu_temp();
break;
case I8K_GET_SPEED:
if (copy_from_user(&val, argp, sizeof(int))) {
return -EFAULT;
}
val = i8k_get_fan_speed(val);
break;
case I8K_GET_FAN:
if (copy_from_user(&val, argp, sizeof(int))) {
return -EFAULT;
}
val = i8k_get_fan_status(val);
break;
case I8K_SET_FAN:
if (restricted && !capable(CAP_SYS_ADMIN)) {
return -EPERM;
}
if (copy_from_user(&val, argp, sizeof(int))) {
return -EFAULT;
}
if (copy_from_user(&speed, argp+1, sizeof(int))) {
return -EFAULT;
}
val = i8k_set_fan(val, speed);
break;
default:
return -EINVAL;
}
if (val < 0) {
return val;
}
switch (cmd) {
case I8K_BIOS_VERSION:
if (copy_to_user(argp, &val, 4)) {
return -EFAULT;
}
break;
case I8K_MACHINE_ID:
if (copy_to_user(argp, buff, 16)) {
return -EFAULT;
}
break;
default:
if (copy_to_user(argp, &val, sizeof(int))) {
return -EFAULT;
}
break;
}
return 0;
}
/*
* Print the information for /proc/i8k.
*/
static int i8k_get_info(char *buffer, char **start, off_t fpos, int length)
{
int n, fn_key, cpu_temp, ac_power;
int left_fan, right_fan, left_speed, right_speed;
cpu_temp = i8k_get_cpu_temp(); /* 11100 µs */
left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
fn_key = i8k_get_fn_status(); /* 750 µs */
if (power_status) {
ac_power = i8k_get_power_status(); /* 14700 µs */
} else {
ac_power = -1;
}
/*
* Info:
*
* 1) Format version (this will change if format changes)
* 2) BIOS version
* 3) BIOS machine ID
* 4) Cpu temperature
* 5) Left fan status
* 6) Right fan status
* 7) Left fan speed
* 8) Right fan speed
* 9) AC power
* 10) Fn Key status
*/
n = sprintf(buffer, "%s %s %s %d %d %d %d %d %d %d\n",
I8K_PROC_FMT,
bios_version,
serial_number,
cpu_temp,
left_fan,
right_fan,
left_speed,
right_speed,
ac_power,
fn_key);
return n;
}
static ssize_t i8k_read(struct file *f, char __user *buffer, size_t len, loff_t *fpos)
{
int n;
char info[128];
n = i8k_get_info(info, NULL, 0, 128);
if (n <= 0) {
return n;
}
if (*fpos >= n) {
return 0;
}
if ((*fpos + len) >= n) {
len = n - *fpos;
}
if (copy_to_user(buffer, info, len) != 0) {
return -EFAULT;
}
*fpos += len;
return len;
}
static char* __init string_trim(char *s, int size)
{
int len;
char *p;
if ((len = strlen(s)) > size) {
len = size;
}
for (p=s+len-1; len && (*p==' '); len--,p--) {
*p = '\0';
}
return s;
}
/* DMI code, stolen from arch/i386/kernel/dmi_scan.c */
/*
* |<-- dmi->length -->|
* | |
* |dmi header s=N | string1,\0, ..., stringN,\0, ..., \0
* | |
* +-----------------------+
*/
static char* __init dmi_string(DMIHeader *dmi, u8 s)
{
u8 *p;
if (!s) {
return "";
}
s--;
p = (u8 *)dmi + dmi->length;
while (s > 0) {
p += strlen(p);
p++;
s--;
}
return p;
}
static void __init dmi_decode(DMIHeader *dmi)
{
u8 *data = (u8 *) dmi;
char *p;
#ifdef I8K_DEBUG
int i;
printk("%08x ", (int)data);
for (i=0; i<data[1] && i<64; i++) {
printk("%02x ", data[i]);
}
printk("\n");
#endif
switch (dmi->type) {
case 0: /* BIOS Information */
p = dmi_string(dmi,data[5]);
if (*p) {
strlcpy(bios_version, p, sizeof(bios_version));
string_trim(bios_version, sizeof(bios_version));
}
break;
case 1: /* System Information */
p = dmi_string(dmi,data[4]);
if (*p) {
strlcpy(system_vendor, p, sizeof(system_vendor));
string_trim(system_vendor, sizeof(system_vendor));
}
p = dmi_string(dmi,data[5]);
if (*p) {
strlcpy(product_name, p, sizeof(product_name));
string_trim(product_name, sizeof(product_name));
}
p = dmi_string(dmi,data[7]);
if (*p) {
strlcpy(serial_number, p, sizeof(serial_number));
string_trim(serial_number, sizeof(serial_number));
}
break;
}
}
static int __init dmi_table(u32 base, int len, int num, void (*fn)(DMIHeader*))
{
u8 *buf;
u8 *data;
DMIHeader *dmi;
int i = 1;
buf = ioremap(base, len);
if (buf == NULL) {
return -1;
}
data = buf;
/*
* Stop when we see al the items the table claimed to have
* or we run off the end of the table (also happens)
*/
while ((i<num) && ((data-buf) < len)) {
dmi = (DMIHeader *)data;
/*
* Avoid misparsing crud if the length of the last
* record is crap
*/
if ((data-buf+dmi->length) >= len) {
break;
}
fn(dmi);
data += dmi->length;
/*
* Don't go off the end of the data if there is
* stuff looking like string fill past the end
*/
while (((data-buf) < len) && (*data || data[1])) {
data++;
}
data += 2;
i++;
}
iounmap(buf);
return 0;
}
static int __init dmi_iterate(void (*decode)(DMIHeader *))
{
unsigned char buf[20];
void __iomem *p = ioremap(0xe0000, 0x20000), *q;
if (!p)
return -1;
for (q = p; q < p + 0x20000; q += 16) {
memcpy_fromio(buf, q, 20);
if (memcmp(buf, "_DMI_", 5)==0) {
u16 num = buf[13]<<8 | buf[12];
u16 len = buf [7]<<8 | buf [6];
u32 base = buf[11]<<24 | buf[10]<<16 | buf[9]<<8 | buf[8];
#ifdef I8K_DEBUG
printk(KERN_INFO "DMI %d.%d present.\n",
buf[14]>>4, buf[14]&0x0F);
printk(KERN_INFO "%d structures occupying %d bytes.\n",
buf[13]<<8 | buf[12],
buf [7]<<8 | buf[6]);
printk(KERN_INFO "DMI table at 0x%08X.\n",
buf[11]<<24 | buf[10]<<16 | buf[9]<<8 | buf[8]);
#endif
if (dmi_table(base, len, num, decode)==0) {
iounmap(p);
return 0;
}
}
}
iounmap(p);
return -1;
}
/* end of DMI code */
/*
* Get DMI information.
*/
static int __init i8k_dmi_probe(void)
{
char **p;
if (dmi_iterate(dmi_decode) != 0) {
printk(KERN_INFO "i8k: unable to get DMI information\n");
return -ENODEV;
}
if (strncmp(system_vendor,DELL_SIGNATURE,strlen(DELL_SIGNATURE)) != 0) {
printk(KERN_INFO "i8k: not running on a Dell system\n");
return -ENODEV;
}
for (p=supported_models; ; p++) {
if (!*p) {
printk(KERN_INFO "i8k: unsupported model: %s\n", product_name);
return -ENODEV;
}
if (strncmp(product_name,*p,strlen(*p)) == 0) {
break;
}
}
return 0;
}
/*
* Probe for the presence of a supported laptop.
*/
static int __init i8k_probe(void)
{
char buff[4];
int version;
int smm_found = 0;
/*
* Get DMI information
*/
if (i8k_dmi_probe() != 0) {
printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
system_vendor, product_name, bios_version);
}
/*
* Get SMM Dell signature
*/
if (i8k_get_dell_signature() != 0) {
printk(KERN_INFO "i8k: unable to get SMM Dell signature\n");
} else {
smm_found = 1;
}
/*
* Get SMM BIOS version.
*/
version = i8k_get_bios_version();
if (version <= 0) {
printk(KERN_INFO "i8k: unable to get SMM BIOS version\n");
} else {
smm_found = 1;
buff[0] = (version >> 16) & 0xff;
buff[1] = (version >> 8) & 0xff;
buff[2] = (version) & 0xff;
buff[3] = '\0';
/*
* If DMI BIOS version is unknown use SMM BIOS version.
*/
if (bios_version[0] == '?') {
strcpy(bios_version, buff);
}
/*
* Check if the two versions match.
*/
if (strncmp(buff,bios_version,sizeof(bios_version)) != 0) {
printk(KERN_INFO "i8k: BIOS version mismatch: %s != %s\n",
buff, bios_version);
}
}
if (!smm_found && !force) {
return -ENODEV;
}
return 0;
}
#ifdef MODULE
static
#endif
int __init i8k_init(void)
{
struct proc_dir_entry *proc_i8k;
/* Are we running on an supported laptop? */
if (i8k_probe() != 0) {
return -ENODEV;
}
/* Register the proc entry */
proc_i8k = create_proc_info_entry("i8k", 0, NULL, i8k_get_info);
if (!proc_i8k) {
return -ENOENT;
}
proc_i8k->proc_fops = &i8k_fops;
proc_i8k->owner = THIS_MODULE;
printk(KERN_INFO
"Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
I8K_VERSION);
return 0;
}
#ifdef MODULE
int init_module(void)
{
return i8k_init();
}
void cleanup_module(void)
{
/* Remove the proc entry */
remove_proc_entry("i8k", NULL);
printk(KERN_INFO "i8k: module unloaded\n");
}
#endif
/* end of file */
