// prototype_test.c   -  e.boelen  -  15 august 2002
// I have connected 4 flip flops to the parallel port, their outputs will be read
// after that you can toggle the flip flops

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h> /* needed for ioperm() */
#include <asm/io.h> /* for outb() and inb() */

#define PORT 0x378

int main(int argc, char *argv[])
{
    int readport,value,getdata;
    int toggleport;
    readport=PORT+1;

    for(;;){
	//// read data from parallel port
	if (ioperm(readport,1,1)) {
		printf("Sorry, you were not able to gain access to the ports\n");
		printf("You must be root to control ports\n");
		getdata=0;
	}
	else {
        	getdata=inb(readport);
		getdata=getdata-15;// assume inputs 5,6,7,8 (binair status 15) are always ON
	}
	printf("readport gave: %d \n",getdata);

	// decode the binair code
	if ( (getdata-128)>=0) {
			printf(" - input 1 - OFF \n");// input 1 is inverted
			getdata=getdata-128;}
	else printf(" - input 1 - ON\n");

	if ( (getdata-64)>=0){
			printf(" - input 2 - ON \n");
			getdata=getdata-64;}
	else printf(" - input 2 - OFF \n");

	if ( (getdata-32)>=0){
			printf(" - input 3 - ON \n");
			getdata=getdata-32;}
	else printf(" - input 3 - OFF \n");

	if ( (getdata-16)>=0){
			printf(" - input 4 - ON \n \n");}
	else printf(" - input 4 - OFF \n");

	// figure out what to send
	printf ("enter a output (1-4) you want to toggle: \n");
	scanf ("%d",&toggleport);
	while (toggleport<=0||toggleport>=5){
		printf("enter a number between 1 and 4 for the port you want to toggle: \n");
		scanf ("%d",&toggleport);
	}
	printf ("sending to port: %d...\n",toggleport);

	if (toggleport==1) value=1;
	if (toggleport==2) value=2;
	if (toggleport==3) value=4;
	if (toggleport==4) value=8;

	//send the data to PORT
	ioperm(PORT,1,1);
	outb(value,PORT);
	sleep(1);
	outb(0,PORT);

	//done
	printf("done\n");
	sleep(1);
    }
	return(0);
}