tiny6410在I2c用户态中的程序设计eeprom

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <linux/types.h>

struct i2c_msg {
unsigned short addr; /* slave address */
unsigned short flags;
unsigned short len; /* msg length */
unsigned char *buf; /* pointer to msg data */
};

struct i2c_rdwr_ioctl_data {
struct i2c_msg *msgs; /* pointers to i2c_msgs */
unsigned int nmsgs; /* number of i2c_msgs */
};

#define I2C_RDWR 0x0707 /* Combined R/W transfer (one STOP only) */

int main()
{
int fd;
struct i2c_rdwr_ioctl_data eeprom_data;
//1. 打开设备文件
fd = open( "/dev/i2c-0", O_RDWR );
if( fd == -1 )
{
printf("error open failed\r\n");
return ;
}

//2. 构造写数据到eeprom的消息
eeprom_data.msgs = (struct i2c_msg *)malloc( 2*sizeof(struct i2c_msg) );

eeprom_data.nmsgs = 1;
eeprom_data.msgs[0].len = 2;
eeprom_data.msgs[0].addr = 0x50;
eeprom_data.msgs[0].flags = 0;
eeprom_data.msgs[0].buf = (unsigned char *)malloc(2);
eeprom_data.msgs[0].buf[0] = 0x10;
eeprom_data.msgs[0].buf[1] = 0x60;

//3. 使用ioctl写入数据
if( 0>ioctl( fd, I2C_RDWR, (unsigned long)&eeprom_data))
{
printf("error write\n");
return ;
}
sleep(1);
//4. 构造从eeprom读取数据的消息
eeprom_data.nmsgs = 2;
eeprom_data.msgs[0].len = 1;
eeprom_data.msgs[0].addr = 0x50;
eeprom_data.msgs[0].flags = 0;
eeprom_data.msgs[0].buf[0] = 0x10;

eeprom_data.msgs[1].len = 1;
eeprom_data.msgs[1].addr = 0x50;
eeprom_data.msgs[1].flags = 1;
eeprom_data.msgs[1].buf = (unsigned char *)malloc(2);
eeprom_data.msgs[1].buf[0] = 0;
//5. 使用ioctl读出数据
if( -1 == ioctl( fd, I2C_RDWR, (unsigned long)&eeprom_data))
{
printf("error read\n");
return ;
}

printf("buff[0]=%x\n",eeprom_data.msgs[1].buf[0]);

//6. 关闭设备
close(fd);

}