linux w5500代码

以下是使用Linux下的w5500驱动程序的示例代码：

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

#define SPI_DEVICE "/dev/spidev0.0"
#define W5500_RST   17

uint8_t tx_buf[1024], rx_buf[1024];

int main(int argc, char *argv[]) {
    int spi_fd, ret;
    struct spi_ioc_transfer xfer;
    uint8_t test_cmd[] = {0x90, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
    uint8_t test_response[128];

    spi_fd = open(SPI_DEVICE, O_RDWR);
    if (spi_fd < 0) {
        printf("Error opening %s: %s\n", SPI_DEVICE, strerror(errno));
        return -1;
    }

    // Set SPI mode
    uint8_t mode = SPI_MODE_0;
    ret = ioctl(spi_fd, SPI_IOC_WR_MODE, &mode);
    if (ret < 0) {
        printf("Error setting SPI mode: %s\n", strerror(errno));
        return -1;
    }

    // Set SPI bits per word
    uint8_t bits = 8;
    ret = ioctl(spi_fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
    if (ret < 0) {
        printf("Error setting SPI bits per word: %s\n", strerror(errno));
        return -1;
    }

    // Set SPI clock frequency
    uint32_t speed = 10000000;
    ret = ioctl(spi_fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
    if (ret < 0) {
        printf("Error setting SPI clock frequency: %s\n", strerror(errno));
        return -1;
    }

    // Reset W5500
    int gpio_fd = open("/sys/class/gpio/export", O_WRONLY);
    if (gpio_fd < 0) {
        printf("Error exporting GPIO pin: %s\n", strerror(errno));
        return -1;
    }
    char buf[4];
    sprintf(buf, "%d", W5500_RST);
    write(gpio_fd, buf, strlen(buf));
    close(gpio_fd);

    gpio_fd = open("/sys/class/gpio/gpio17/direction", O_WRONLY);
    if (gpio_fd < 0) {
        printf("Error setting GPIO direction: %s\n", strerror(errno));
        return -1;
    }
    write(gpio_fd, "out", 3);
    close(gpio_fd);

    gpio_fd = open("/sys/class/gpio/gpio17/value", O_WRONLY);
    if (gpio_fd < 0) {
        printf("Error setting GPIO value: %s\n", strerror(errno));
        return -1;
    }
    write(gpio_fd, "0", 1);
    usleep(1000);
    write(gpio_fd, "1", 1);
    close(gpio_fd);

    // Wait for W5500 to initialize
    usleep(1000000);

    // Test SPI communication with W5500
    memset(&xfer, 0, sizeof(xfer));
    xfer.tx_buf = (unsigned long)test_cmd;
    xfer.rx_buf = (unsigned long)test_response;
    xfer.len = sizeof(test_cmd);
    xfer.speed_hz = speed;
    xfer.bits_per_word = bits;

    ret = ioctl(spi_fd, SPI_IOC_MESSAGE(1), &xfer);
    if (ret < 0) {
        printf("Error sending SPI command: %s\n", strerror(errno));
        return -1;
    }

    close(spi_fd);

    printf("SPI test response: %02X%02X%02X%02X%02X%02X\n", test_response[0], test_response[1], test_response[2], test_response[3], test_response[4], test_response[5]);

    return 0;
}

这个示例代码使用SPI总线与W5500通信，并测试SPI通信是否正常工作。在示例代码中，我们使用了Linux下的SPIDEV驱动程序，并使用ioctl函数来设置SPI模式、位数和时钟频率。在测试SPI通信之前，我们还将W5500芯片进行了重置。