linux/drivers/char/i8k.c

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/*
* 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/dmi.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
static char bios_version[4];
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 ignore_dmi;
module_param(ignore_dmi, bool, 0);
MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
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;
static inline char *i8k_get_dmi_data(int field)
{
return dmi_get_system_info(field) ? : "N/A";
}
/*
* 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(&regs)) < 0) {
return rc;
}
return regs.eax;
}
/*
* 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(&regs)) < 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(&regs)) < 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(&regs)) < 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(&regs)) < 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(&regs)) < 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(&regs)) < 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(&regs)) < 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 = 0;
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);
strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL), sizeof(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 <20>s */
left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 <20>s */
right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 <20>s */
left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 <20>s */
right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 <20>s */
fn_key = i8k_get_fn_status(); /* 750 <20>s */
if (power_status) {
ac_power = i8k_get_power_status(); /* 14700 <20>s */
} 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,
dmi_get_system_info(DMI_PRODUCT_SERIAL) ? : "N/A",
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 struct dmi_system_id __initdata i8k_dmi_table[] = {
{
.ident = "Dell Inspiron",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
},
},
{
.ident = "Dell Latitude",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
},
},
{ }
};
/*
* Probe for the presence of a supported laptop.
*/
static int __init i8k_probe(void)
{
char buff[4];
int version;
/*
* Get DMI information
*/
if (!dmi_check_system(i8k_dmi_table)) {
if (!ignore_dmi && !force)
return -ENODEV;
printk(KERN_INFO "i8k: not running on a supported Dell system.\n");
printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
i8k_get_dmi_data(DMI_SYS_VENDOR),
i8k_get_dmi_data(DMI_PRODUCT_NAME),
i8k_get_dmi_data(DMI_BIOS_VERSION));
}
strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION), sizeof(bios_version));
/*
* Get SMM Dell signature
*/
if (i8k_get_dell_signature() != 0) {
printk(KERN_ERR "i8k: unable to get SMM Dell signature\n");
if (!force)
return -ENODEV;
}
/*
* Get SMM BIOS version.
*/
version = i8k_get_bios_version();
if (version <= 0) {
printk(KERN_WARNING "i8k: unable to get SMM BIOS version\n");
} else {
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 (!dmi_get_system_info(DMI_BIOS_VERSION))
strlcpy(bios_version, buff, sizeof(bios_version));
/*
* Check if the two versions match.
*/
if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
printk(KERN_WARNING "i8k: BIOS version mismatch: %s != %s\n",
buff, bios_version);
}
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())
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 */