/* chaser.c -- An example of wasted cpu cycles */ 

#include <stdio.h>

#include <asm/types.h>   /* headers for architecture specific data types                         */
#include <unistd.h>      /* contains the prototype for i386 specific ioperm functioni            */
#include <asm/io.h>      /* obviously architecture specific (asm directory) for inb, outb macros */

/* #define LP_BASE 0x240 */
//board we made is 240 rather than 0x378 or 0x278 as normal parallel port
#define LP_BASE 0x378

int main(void) {

	int portdata = 3;
	int shiftin; 

	/* attempt to reserve region in io space */
	if(ioperm(LP_BASE, 3, 1) < 0) {
		fprintf(stderr, "Cannot reserve region in io space, aborting...\n");
		exit(1);
	}

	while(1) {
		/* send data byte to io port */
		outb(~ (__u8)portdata, LP_BASE);

		if(portdata & 0x80) {
			shiftin = 1;
		}
		else {
			shiftin = 0;
		}

		/* shift pattern left */
		portdata = 0xFF & ((portdata << 1) | shiftin);

		/* pause to let user see pattern */
		usleep(50000);

	}

	/* attempt to release reserved region in io space */
	if(ioperm(LP_BASE, 3, 0) < 0) {
		fprintf(stderr, "Cannot release region in io space, aborting...\n");
		exit(1);
	}

	return(0);  /* just to be nice ;) */

}