max6650.c

max6650风扇控制芯片在linux 2.6.x下的控制程序

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <termios.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/ioctl.h>
#include <linux/i2c-dev.h>
#include <asm/errno.h>

#include "max6650.h"

#define I2C_SLAVE 0x0703
#define ID_PHY_1 0x3e 
#define ID_PHY_2 0x90

#define MAX6650_INT_CLK 254000 	/* Default clock speed - 254 kHz */ 

static int 	max6650_read_reg(int file, u8 reg, u8 * data);
static int  max6650_write_reg(int file, u8 reg, u8 data);
static int  max6650_get_status(int file, struct max6650_data *data);


main(int argc, char **argv)
{
	int file;
  	int adapter_nr = 0;
  	char filename[20];
	int  ret;
	int  addr;
	struct max6650_data value;
	int kscale, ktach, fclk, rpm, speed; 

	if (argc < 3 || argc >5){
		printf("rtc help:\n\n"
			"fan -g num 	: get status form FAN controller device(num).\n"
			"fan -s num1  num2 	: set fan speed(num2) to FAN controller device(num1).\n"
			);

		exit(1);
	}
  	sprintf(filename, "/dev/i2c-%d", adapter_nr);
  	if ((file = open(filename, O_RDWR)) < 0) {
		perror("No such i2c device!\n");
  	  	exit(1);
  	}
	
	if(argv[2][0] == '1')
		addr = ID_PHY_1>>1; /* The I2C address */
	else if(argv[2][0] == '2')
		addr = ID_PHY_2>>1; /* The I2C address */
	else{
			printf("No such number, just 1 or 2 \n");		
			exit(1);
	}

	if ((ret = ioctl(file, I2C_SLAVE, addr)) < 0) {
		if(ret ==  -EBUSY)
			printf("Device busy\n");
		if(ret == -EINVAL)
			printf("invalid addr\n");
		printf("No such slave device. %d\n ", ret);
		close(file);
   		exit(1);
  	}
	

	if(argv[1][1] == 'g' ){

		max6650_get_status(file, &value);
        /*
         * Use the datasheet equation:
         *
         *    FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)]
         *
         * then multiply by 60 to give rpm.
         */
        kscale = 1 << (value.config & 7);
        ktach  = value.speed;
        fclk   = MAX6650_INT_CLK;
        speed  = 60 * kscale * fclk / (256 * (ktach + 1));
        rpm  = (value.tach[0] - 1) * 60 /2 ;
		printf("current fan(%c) setting speed: %d rpm, tach: %d  rpm.\n",
											 argv[2][0], speed, rpm);
	}
	if(argv[1][1] == 's' ){
		char *data = argv[3];
		
		max6650_get_status(file, &value);
		
		speed = atoi(data);
		if(speed <1000){
			printf("The setting speed must be bigger than 1000 rpm.\n");
			speed = 1000;
		}	
		kscale = 1 << (value.config & 7);
		fclk   = MAX6650_INT_CLK;
		ktach  = ((fclk * kscale) / (256 * speed / 60)) - 1;
		
		value.speed  = ktach;
		value.config = (value.config & ~MAX6650_CFG_MODE_MASK) |
                                            MAX6650_CFG_MODE_CLOSED_LOOP;
        max6650_write_reg (file, MAX6650_REG_CONFIG, value.config);
        max6650_write_reg (file, MAX6650_REG_SPEED, value.speed);

	}
	close(file);
}


static int
max6650_read_reg(int file, u8 reg, u8 * data)
{
	u8 buf[2];
	int ret;
	
	memset(buf, 0, sizeof(buf));
	buf[0] = reg;
	write(file, buf, 1);
	ret = read(file, buf, 1);
    if (ret < 0){
        perror("read error!\n");
		close(file);
        exit(1);
    }
	*data = buf[0];
	return 0;
}

static int
max6650_write_reg(int file, u8 reg, u8 data)
{
	u8 buf[3];
	int ret;

	memset(buf, 0, sizeof(buf));
	buf[0] = reg;
	buf[1] = data;
	ret = write(file, buf, 2);
	if(ret< 0){
 		perror("error writing data! \n");
		close(file);
		exit(1);
	}

	return 0;
}


static int 
max6650_get_status(int file, struct max6650_data *data)
{
 
   	if (!data){
		close(file);
       	return -EINVAL;
	}

	max6650_read_reg (file, MAX6650_REG_SPEED, &(data->speed));
    max6650_read_reg (file, MAX6650_REG_CONFIG, &(data->config));
    max6650_read_reg (file, tach_reg[0], &(data->tach[0]));
	max6650_read_reg (file, MAX6650_REG_COUNT, &(data->count));

   	return 0;
}