Jetson Nano Uart C code

#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

#include <stdio.h>
#include <signal.h>
#include <unistd.h>

static int set_interface_attribs (int fd, int speed, int parity)
{
    struct termios tty;
    memset (&tty, 0, sizeof tty);
    if (tcgetattr (fd, &tty) != 0)
    {
            printf ("error %d from tcgetattr\n", errno);
            return -1;
    }

    cfsetospeed (&tty, speed);
    cfsetispeed (&tty, speed);
    cfmakeraw(&tty); /* RAW mode */

    tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8;     // 8-bit chars
    // disable IGNBRK for mismatched speed tests; otherwise receive break
    // as \000 chars
    tty.c_iflag &= ~IGNBRK;         // disable break processing
    tty.c_lflag = 0;                // no signaling chars, no echo,
                                    // no canonical processing
    tty.c_oflag = 0;                // no remapping, no delays
    tty.c_cc[VMIN]  = 0;            // read doesn't block
    tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

    tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off xon/xoff ctrl

    tty.c_cflag |= (CLOCAL | CREAD);// ignore modem controls,
                                    // enable reading
    tty.c_cflag &= ~(PARENB | PARODD);      // shut off parity
    tty.c_cflag |= parity;
    tty.c_cflag &= ~CSTOPB;
    tty.c_cflag &= ~CRTSCTS;

    if (tcsetattr (fd, TCSANOW, &tty) != 0)
    {
            printf ("error %d from tcsetattr\n", errno);
            return -1;
    }
    return 0;
}

static void set_blocking (int fd, int should_block)
{
    struct termios tty;
    memset (&tty, 0, sizeof tty);
    if (tcgetattr (fd, &tty) != 0)
    {
            printf ("error %d from tggetattr\n", errno);
            return;
    }

    tty.c_cc[VMIN]  = should_block ? 1 : 0;
    tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

    if (tcsetattr (fd, TCSANOW, &tty) != 0)
            printf ("error %d setting term attributes\n", errno);
}

int main(int argc, char**argv)

{

    const char *ttyName = "/dev/ttyTHS1";

    int ttyFd = open (ttyName, O_RDWR | O_NOCTTY | O_SYNC);

    if (ttyFd) {

        set_interface_attribs (ttyFd, B9600, 0);  // set speed to 115,200 bps, 8n1 (no parity)

        set_blocking (ttyFd, 0);                // set no blocking

    } else

        printf ("error %d opening %s: %s\n", errno, ttyName, strerror (errno));

  char data[5] = "1234"

  write(fd, data, 4);

  return 0;

}