求救，有没有做过atmel加密芯片，I2C通讯？

走好每一步 2019-07-18 10:08:05

/sys/bus/i2c/devices # ls
0-0062 i2c-0

设备已经挂上去，但是不知道怎么通讯
slaveaddr怎么获取？

#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <string.h>

#include <linux/i2c.h>

#include <linux/i2c-dev.h> 



//#define CHIP_ADDR 0x20

#define I2C_DEV "/dev/i2c-0"//i2c_dev为i2c　adapter创建的别名

//读操作先发Slaveaddr_W+Regaddr_H+Regaddr_L 3个字节来告诉设备操作器件及两个byte参数

//然后发送Slaveaddr_R读数据

static int iic_read(int fd, char buff[], int addr, int count)

{

    int res;

    char sendbuffer1[2];

    sendbuffer1[0]=addr>>8;

    sendbuffer1[1]=addr;

    write(fd,sendbuffer1,2);      

        res=read(fd,buff,count);

        printf("read %d byte at 0x%x/n", res, addr);

        return res;

}

//在写之前，在数据前加两个byte的参数，根据需要解析

static int iic_write(int fd, char buff[], int addr, int count)

{

        int res;

        int i,n;

        static char sendbuffer[100];

        memcpy(sendbuffer+2, buff, count);

        sendbuffer[0]=addr>>8;

    sendbuffer[1]=addr;

        res=write(fd,sendbuffer,count+2);

        printf("write %d byte at 0x%x/n", res, addr);

}

int main(void){

    int fd;

    int res;

    char ch;

    char buf[50];

    int regaddr,i,slaveaddr;

    fd = open(I2C_DEV, O_RDWR);// I2C_DEV /dev/i2c-0

        if(fd < 0){

                printf("####i2c test device open failed####/n");

                return (-1);

        }

    printf("please input slave addr:");

    scanf("%x",&slaveaddr);

    printf("input slave addr is:%x/n",slaveaddr);

           printf("please input reg addr:");

    scanf("%x",®addr);

    printf("input slave addr is:%x/n",regaddr);

    res = ioctl(fd,I2C_TENBIT,0);   //not 10bit

           res = ioctl(fd,I2C_SLAVE,slaveaddr);    //设置I2C从设备地址[6:0]

        while((ch=getchar())!='0'){

        switch(ch){

            case '1':

                printf("getch test success/n");

                break;

            case '2':

                buf[0]=0xFF;

                buf[1]=0xFF;

                buf[2]=0xFF;

                buf[3]=0xFF;

                buf[4]=0xFF;

                printf("read i2c test/n");

                res=iic_read(fd,buf,regaddr,5);

                printf("%d bytes read:",res);

                for(i=0;i<res;i++){

                    printf("%d ",buf[i]);

                }

                printf("/n");

                break;

            case '3':

                buf[0]=0xAA;

                buf[1]=0x55;

                buf[2]=0xAA;

                printf("write i2c test/n");

                res=iic_write(fd,buf,regaddr,2);

                printf("%d bytes write success/n");

                break;

            default:

                printf("bad command/n");

                break;

        }

    }

    return 0;

}