树莓派5 spi控制

树莓派5 spi控制

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

#define SPI_DEVICE_PATH "/dev/spidev0.0"
uint8_t tx_bf[200];



typedef struct spi_args_struct
{
    int fd;
    uint8_t tx_buffer[1000];
    uint8_t rx_buffer[1000];
    struct spi_ioc_transfer transfer;

}spi_args_s;

int api_spi_init(char * dev)
{
    int fd = 0;
    if ((fd = open(dev, O_RDWR)) < 0)
    {
        perror("Failed to open SPI device");
        return -1;
    }
    return fd;
}

int api_spi_cfg(struct spi_args_struct *spi_args_obj)
{
    /* 配置收发缓存 */
    spi_args_obj->transfer.tx_buf = (unsigned long) spi_args_obj->tx_buffer;
    spi_args_obj->transfer.rx_buf = (unsigned long) spi_args_obj->rx_buffer;

    /* Configure SPI mode and bits per word */
    uint8_t mode = SPI_MODE_0;
    uint8_t bits = 8;
    if (ioctl(spi_args_obj->fd, SPI_IOC_WR_MODE, &mode) < 0)
    {
        perror("Failed to set SPI mode");
        close(spi_args_obj->fd);
        return -1;
    }
    if (ioctl(spi_args_obj->fd, SPI_IOC_WR_BITS_PER_WORD, &bits) < 0)
    {
        perror("Failed to set SPI bits per word");
        close(spi_args_obj->fd);
        return -1;
    }
}

void api_spi_send(struct spi_args_struct *spi_args_obj, uint8_t *data, uint16_t size)
{

    spi_args_obj->transfer.len = size;
    memcpy((spi_args_obj->tx_buffer), data, spi_args_obj->transfer.len);
    printf("Send %d bytes of data  max speed: %d Hz.\n", spi_args_obj->transfer.len, spi_args_obj->transfer.speed_hz);
}


spi_args_s spi_args_obj = 
{
    .transfer = 
    {
        .len = 10,
        .delay_usecs = 0,
        .speed_hz = 31200000, // SPI speed in Hz
        .bits_per_word = 8,
    },
};
#if 0 //测试代码
int main()
{

    /* Open the SPI device */
    spi_args_obj.fd = api_spi_init(SPI_DEVICE_PATH);

    /* Configure SPI mode and bits per word */
    api_spi_cfg(&spi_args_obj);

    /* Send Data */

    for (int i = 0; i < 200; i++)
    {
        tx_bf[i] = i;
    }

    while (1)
    {

        api_spi_send(&spi_args_obj, tx_bf, 10);
        printf("\r\n");
        if (ioctl(spi_args_obj.fd, SPI_IOC_MESSAGE(1), &(spi_args_obj.transfer) ) < 0)
        {
            perror("Failed to perform SPI transfer");
            close(spi_args_obj.fd);
            return -1;
        }
        sleep(2);
        printf("sleep out\n");
    }

    /* Close the SPI device */
    close(spi_args_obj.fd);

    return 0;
}

#endif


int spi_set_mode(int fd, int mode)
{
    return ioctl(fd, SPI_IOC_WR_MODE, &mode);
}

int spi_read_mode(int fd, int mode)
{
    return ioctl(fd, SPI_IOC_RD_MODE, &mode);
}

int spi_set_bit_order(int fd, int bit_order)
{
    return ioctl(fd, SPI_IOC_WR_LSB_FIRST, bit_order);
}

int spi_read_bit_order(int fd, int bit_order)
{
    return ioctl(fd, SPI_IOC_RD_LSB_FIRST, &bit_order);
}

int spi_set_bits_per_word(int fd, int bits_per_word)
{
    return ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits_per_word);
}

int spi_read_bits_per_word(int fd, int bits_per_word)
{
    return ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits_per_word);
}

int spi_set_max_speed(int fd, int max_speed)
{
    ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &max_speed);
}

int spi_read_max_speed(int fd, int max_speed)
{
    ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &max_speed);
}