mbtk/test/libgsw_lib/gsw_mdio_test.c

#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdint.h>
#include <stdio.h>

struct mdio_reg_op 
{
	uint32_t reg;
	uint32_t val;
};

#define DEVICE_NAME   "/dev/mdio_misc"

int main(int argc, char*argv[])
{
    int fd;
    ssize_t ret;
    struct mdio_reg_op reg_op;

    if (argc != 2 && argc != 3)
    {
        fprintf(stderr, "Usage: %s <reg> [val]\n", argv[0]);
        fprintf(stderr, "  Read:  %s 0x0 \n", argv[0]);
        fprintf(stderr, "  Write: %s 0x0 0x2100\n", argv[0]);
        return -1;
    }

    fd = open(DEVICE_NAME, O_RDWR);
    if (fd < 0)
    {
        perror("Failed to open device");
        return -1;
    }

    reg_op.reg = strtoul(argv[1], NULL, 16);

    if (argc == 2)
    {
	ret = read(fd, &reg_op, sizeof(struct mdio_reg_op));
        if (ret != sizeof(struct mdio_reg_op)) 
	{
            perror("Read operation failed");
            close(fd);
            return -1;
        }
        printf("Read success: reg=0x%08X, val=0x%08X\n", reg_op.reg, reg_op.val);
    }
    else
    {
        reg_op.val = strtoul(argv[2], NULL, 16);
        ret = write(fd, &reg_op, sizeof(reg_op));
        if (ret != sizeof(reg_op)) 
	{
            perror("Write operation failed");
            close(fd);
            return -1;
        }
        printf("Write success: reg=0x%08X, val=0x%08X\n", reg_op.reg, reg_op.val);
    }

    close(fd);
    return 0;
}