i8k.c

linux和2410结合开发 用他可以生成2410所需的zImage文件

/*
 * 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 <[e-mail]>
 *
 * 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/version.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		"1.7 21/11/2001"

#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] = "?";

int force = 0;
int power_status = 0;

MODULE_AUTHOR("Massimo Dal Zotto ([e-mail])");
MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
MODULE_LICENSE("GPL");
MODULE_PARM(force, "i");
MODULE_PARM(power_status, "i");
MODULE_PARM_DESC(force, "Force loading without checking for supported models");
MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");

static ssize_t i8k_read(struct file *, char *, 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(&regs)) < 0) {
	return rc;
    }

    return regs.eax;
}

/*
 * Read the machine id.
 */
static int i8k_get_serial_number(unsigned char *buff)
{
    strncpy(buff, serial_number, 16);
    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(&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;
    int speed;
    unsigned char buff[16];

    if (!arg) {
	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, (int *)arg, sizeof(int))) {
	    return -EFAULT;
	}
	val = i8k_get_fan_speed(val);
	break;

    case I8K_GET_FAN:
	if (copy_from_user(&val, (int *)arg, sizeof(int))) {
	    return -EFAULT;
	}
	val = i8k_get_fan_status(val);
	break;

    case I8K_SET_FAN:
	if (copy_from_user(&val, (int *)arg, sizeof(int))) {
	    return -EFAULT;
	}
	if (copy_from_user(&speed, (int *)arg+1, sizeof(int))) {
	    return -EFAULT;
	}
	val = i8k_set_fan(val, speed);
	break;

    default:
	return -EINVAL;
    }

    if (val < 0) {
	return val;
    }

    switch (cmd) {