#include <stdio.h>
#include <bcm2835.h>

int assign[15] = {17,18,27,22,23,24,25,4,2,3,10,9,11,8,7};

void GPIO_out(int data, int mode){
	int i;
	mode = mode & 1;	// mode=0 : active high / mode=1 : active low
	data = data & 255;
	for (i=0; i<8; i++) {
		bcm2835_gpio_write( assign[i], ( ( (data >>i) & 1) ^ mode ) );
	}
}

void EXT_out(int data, int mode){
	int i;
	mode = mode & 1;	// mode=0 : active high / mode=1 : active low
	data = data & 127;
	for (i=0; i<7; i++) {
		bcm2835_gpio_write( assign[i+8], ( ( (data >>i) & 1) ^ mode ) );
	}
}

int main(int argc, char *argv[])
{
	int i, p[3];

	if(argc != 4){
		printf("Format Error (;_;)\n");
		printf("usage : GPIO_out para1 para2 para3\n");
		printf("\tpara1 = port : 0=GPIO[0-7], 1=EXT[0-6]\n");
		printf("\tpara2 = data : 0-255(GPIO), 0-127(EXT)\n");
		printf("\tpara3 = mode : 0=active_HI, 1=active_LOW\n");
		return 1;
	}
	for(i=0; i<3; i++){
		p[i] = atoi(argv[i+1]);
	}
//	printf("port=%d, data=%d, mode=%d\n", p[0], p[1], p[2]);

	if (!bcm2835_init()){
		printf("GPIO is not found.\n");
		return 1;
	}
	for (i=0; i<15; i++){
		bcm2835_gpio_fsel(assign[i], BCM2835_GPIO_FSEL_OUTP);
	}

	switch(p[0]){
		case 0:
			GPIO_out(p[1], p[2]);
			break;
		case 1:
			EXT_out(p[1], p[2]);
			break;
	}
	bcm2835_close();
}