/*
 * example.c: very simple example of port I/O
 *
 * This code does nothing useful, just a port write, a pause,
 * and a port read. Compile with `gcc -O2 -o example example.c',
 * and run as root with `./example'.
 */

#include <stdio.h>
#include <unistd.h>
#include <asm/io.h>

#define BASEPORT 0x378 /* lp1 */

int main()
{

  int byte=0;

  /* Get access to the ports */
  if (ioperm(BASEPORT, 3, 1)) {perror("ioperm"); exit(1);}
  
  while(1)
  {
    /* Set the data signals (D0-7) of the port to all low (0) */
    outb(byte, BASEPORT); printf("%i\n",byte);
  
    /* Sleep for a while */
    usleep(10000000);
  
    /* Read from the status port (BASE+1) and display the result */
    printf("status: %d\n", inb(BASEPORT + 1));

    if(byte)
      byte=0;
    else
      byte=255;
  }

  /* We don't need the ports anymore */
  if (ioperm(BASEPORT, 3, 0)) {perror("ioperm"); exit(1);}

  exit(0);
}

/* end of example.c */