LInux_SPI_APP

LInux_SPI_APP

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#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 <string.h>
#include <strings.h>


#define SPI_DEBUG 0
 
 
/* 
    PC0  clk
    PC1     cs
    PC2     miso
    PC3     mosi
    PD0     DSX
    PA1     rst
    
*/



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 uint32_t speed = 20 * 1000;/* 设置12M传输速度 */
static uint16_t delay = 0;
static int g_SPI_Fd = 0;

unsigned char r_buf[256];
unsigned char w_buf[256];

 
 
 
//SPI_Transfer
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,
                .speed_hz = 0,

                .delay_usecs = delay,
                .bits_per_word = 2
        };

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

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





//SPI_Write
int SPI_Write(uint8_t *TxBuf, int len)
{
        int ret;
        int fd = g_SPI_Fd;

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

        return ret;
}
 
 
 
 
//SPI_Read
int SPI_Read(uint8_t *RxBuf, int len)
{
        int ret;
        int fd = g_SPI_Fd;
        ret = read(fd, RxBuf, len);
        if (ret < 0)
                printf("SPI Read error\n");
        else{
#if SPI_DEBUG
                int i;
                printf("SPI Read [len:%d]:", len);
                for (i = 0; i < len; i++){
                        if (i % 8 == 0)
                                printf("\n\t");
                        printf("0x%02X ", RxBuf[i]);
                }
                printf("\n");
#endif        
        }
        return ret;
}
 

 
 
 
//SPI_Open
int SPI_Open(const char* device)
{
        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)
                printf("can't open device");
        else
                printf("SPI - Open Succeed. Start Init SPI...\n");

        g_SPI_Fd = fd;
        /*
         * spi mode
         */
        ret = ioctl(fd, SPI_IOC_WR_MODE, &mode);       //设置spi_device的mode，并调用spi_setup立即使设置生效
        if (ret == -1)
                printf("can't set spi mode");

        ret = ioctl(fd, SPI_IOC_RD_MODE, &mode);      //读取spi_device的mode
        if (ret == -1)
                printf("can't get spi mode");

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

        ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);  //读取spi_device的bits_per_word.
        if (ret == -1)
                printf("can't get bits per word");

        /*
         * max speed hz
         */
        ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);  //设置时钟速率
        if (ret == -1)
                printf("can't set max speed hz");

        ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);  //读取spi_device的max_speed_hz
        if (ret == -1)
                printf("can't get max speed hz");

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

        return ret;
}

 



//SPI_Close
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;
}



//SPI_LookBackTest
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;

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

        return ret;
}





int main(void)
{
        printf("spi lcd main ok!\n");

#if 1
        SPI_Open("/dev/spidev0.0");
        //  uint8_t  spi_tx_data[5]={0x71,0x72,0x73,0x74,0x75};
        uint8_t  spi_tx_data[2]={0xaa,0x55};
        while(1){
                SPI_Write(spi_tx_data, 2);
                static int p=0;
                if(p==0){
                        p=1;
                        system("echo 1  > /sys/class/gpio/gpio96/value");  //DSX
                        system("echo 1  > /sys/class/gpio/gpio1/value");   //rst
                }else{
                        p=0;
                        system("echo 0  > /sys/class/gpio/gpio96/value");
                        system("echo 0  > /sys/class/gpio/gpio1/value");
                }
                printf("spi data ok!\n");
                usleep(5000);
        }

#endif

}

 

 

 

 Makefile:

 
CROSS_COMPILE = /opt/gcc-arm-8.2-2018.08-x86_64-arm-linux-gnueabihf/bin/arm-linux-gnueabihf-
CC            = $(CROSS_COMPILE)gcc 
myapp    = spi_app.c
MYAPP    = spi_app

all:
    $(CC) $(myapp) -o $(MYAPP)

 

 

 

 

 

 

 

 

 

 

 

 

笔记

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1.