/*
 * Copyright (C) 2024 LingYun IoT System Studio
 * Author: Guo Wenxue <guowenxue@gmail.com>
 *
 * A character skeleton driver test code in user space.
 */

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main (int argc, char **argv)
{
    char      *devname = "/dev/chrdev0";
    char       buf[1024];
    int        rv = 0;
    int        fd;

    fd = open(devname, O_RDWR);
    if( fd < 0 )
    {
        printf("Open device %s failed: %s\n", devname, strerror(errno));
        return 1;
    }

    rv = write(fd, "Hello", 5);
    if( rv< 0)
    {
        printf("Write data into device failed, rv=%d: %s\n", rv, strerror(errno));
        rv = 2;
        goto cleanup;
    }
    printf("Write %d bytes data okay\n", rv);

    memset(buf, 0, sizeof(buf));
    rv = read(fd, buf, sizeof(buf));
    if( rv< 0)
    {
        printf("Read data from device failed, rv=%d: %s\n", rv, strerror(errno));
        rv = 3;
        goto cleanup;
    }
    printf("Read %d bytes data: %s\n", rv, buf);

cleanup:
    close(fd);
    return rv;
}