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;
}

源码：ARM_SPI.rar