Linux下SPI测试程序

/*
* 说明:SPI通讯实现
* 方式一: 同时发送与接收实现函数: SPI_Transfer()
* 方式二:发送与接收分开来实现
* SPI_Write() 只发送
* SPI_Read() 只接收
* 两种方式不同之处:方式一,在发的过程中也在接收,第二种方式,收与发单独进行
* Created on: 2013-5-28
* Author: lzy
*/


#include <stdint.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/spi/spidev.h>


#include "Debug.h"
#define SPI_DEBUG 0


static const char *device = "/dev/spidev0.0";
static uint8_t mode = 0; /* SPI通信使用全双工,设置CPOL=0,CPHA=0。 */
static uint8_t bits = 8; /* 8bits读写,MSB first。*/
static uint32_t speed = 12 * 1000 * 1000;/* 设置12M传输速度 */
static uint16_t delay = 0;
static int g_SPI_Fd = 0;


static void pabort(const char *s)
{
perror(s);
abort();
}


/**
* 功 能:同步数据传输
* 入口参数 :
* TxBuf -> 发送数据首地址
* len -> 交换数据的长度
* 出口参数:
* RxBuf -> 接收数据缓冲区
* 返回值:0 成功
* 开发人员:Lzy 2013-5-22
*/
int SPI_Transfer(const uint8_t *TxBuf, uint8_t *RxBuf, int len)
{
int ret;
int fd = g_SPI_Fd;


struct spi_ioc_transfer tr ={
.tx_buf = (unsigned long) TxBuf,
.rx_buf = (unsigned long) RxBuf,
.len =len,
.delay_usecs = delay,
};


ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
if (ret < 1)
pr_err("can't send spi message");
else
{
#if SPI_DEBUG
int i;
pr_debug("nsend spi message Succeed");
pr_debug("nSPI Send [Len:%d]: ", len);
for (i = 0; i < len; i++)
{
if (i % 8 == 0)
printf("nt");
printf("0x%02X ", TxBuf[i]);
}
printf("n");


pr_debug("SPI Receive [len:%d]:", len);
for (i = 0; i < len; i++)
{
if (i % 8 == 0)
printf("nt");
printf("0x%02X ", RxBuf[i]);
}
printf("n");
#endif
}
return ret;
}


/**
* 功 能:发送数据
* 入口参数 :
* TxBuf -> 发送数据首地址
*len -> 发送与长度
*返回值:0 成功
* 开发人员:Lzy 2013-5-22
*/
int SPI_Write(uint8_t *TxBuf, int len)
{
int ret;
int fd = g_SPI_Fd;


ret = write(fd, TxBuf, len);
if (ret < 0)
pr_err("SPI Write errorn");
else
{
#if SPI_DEBUG
int i;
pr_debug("nSPI Write [Len:%d]: ", len);
for (i = 0; i < len; i++)
{
if (i % 8 == 0)
printf("nt");
printf("0x%02X ", TxBuf[i]);
}
printf("n");


#endif
}


return ret;
}


/**
* 功 能:接收数据
* 出口参数:
* RxBuf -> 接收数据缓冲区
* rtn -> 接收到的长度
* 返回值:>=0 成功
* 开发人员:Lzy 2013-5-22
*/
int SPI_Read(uint8_t *RxBuf, int len)
{
int ret;
int fd = g_SPI_Fd;
ret = read(fd, RxBuf, len);
if (ret < 0)
pr_err("SPI Read errorn");
else
{
#if SPI_DEBUG
int i;
pr_debug("SPI Read [len:%d]:", len);
for (i = 0; i < len; i++)
{
if (i % 8 == 0)
printf("nt");
printf("0x%02X ", RxBuf[i]);
}
printf("n");
#endif
}


return ret;
}


/**
* 功 能:打开设备 并初始化设备
* 入口参数 :
* 出口参数:
* 返回值:0 表示已打开 0XF1 表示SPI已打开 其它出错
* 开发人员:Lzy 2013-5-22
*/
int SPI_Open(void)
{
int fd;
int ret = 0;


if (g_SPI_Fd != 0) /* 设备已打开 */
return 0xF1;


fd = open(device, O_RDWR);
if (fd < 0)
pabort("can't open device");
else
pr_debug("SPI - Open Succeed. Start Init SPI...n");


g_SPI_Fd = fd;
/*
* spi mode
*/
ret = ioctl(fd, SPI_IOC_WR_MODE, &mode);
if (ret == -1)
pabort("can't set spi mode");


ret = ioctl(fd, SPI_IOC_RD_MODE, &mode);
if (ret == -1)
pabort("can't get spi mode");


/*
* bits per word
*/
ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
if (ret == -1)
pabort("can't set bits per word");


ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
if (ret == -1)
pabort("can't get bits per word");


/*
* max speed hz
*/
ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
if (ret == -1)
pabort("can't set max speed hz");


ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
if (ret == -1)
pabort("can't get max speed hz");


pr_debug("spi mode: %dn", mode);
pr_debug("bits per word: %dn", bits);
pr_debug("max speed: %d KHz (%d MHz)n", speed / 1000, speed / 1000 / 1000);


return ret;
}


/**
* 功 能:关闭SPI模块
*/
int SPI_Close(void)
{
int fd = g_SPI_Fd;


if (fd == 0) /* SPI是否已经打开*/
return 0;
close(fd);
g_SPI_Fd = 0;


return 0;
}


/**
* 功 能:自发自收测试程序
* 接收到的数据与发送的数据如果不一样 ,则失败
* 说明:
* 在硬件上需要把输入与输出引脚短跑
* 开发人员:Lzy 2013-5-22
*/
int SPI_LookBackTest(void)
{
int ret, i;
const int BufSize = 16;
uint8_t tx[BufSize], rx[BufSize];


bzero(rx, sizeof(rx));
for (i = 0; i < BufSize; i++)
tx[i] = i;


pr_debug("nSPI - LookBack Mode Test...n");
ret = SPI_Transfer(tx, rx, BufSize);
if (ret > 1)
{
ret = memcmp(tx, rx, BufSize);
if (ret != 0)
{
pr_err("LookBack Mode Test errorn");
//pabort("error");
}
else
pr_debug("SPI - LookBack Mode OKn");
}

return ret;
}

posted @ 2015-09-30 09:35  苏博  阅读(3063)  评论(0编辑  收藏