#include <stdio.h>
#include <fcntl.h>


int main(int argc, char **argv) {
	
	unsigned int gpio, old_gpio;
	unsigned int pin;

	int gpioouten=open("/dev/gpio/outen",O_RDWR);

	if (argc!=3) {
		printf("%s <poll | enable | disable> <pin>\n",argv[0]);
		exit(1);
	}

	pin = 1<<atoi(argv[2]);
	if (!strcmp(argv[1],"poll")) {
		int gpioin=open("/dev/gpio/in",O_RDWR);
		read(gpioouten, &gpio, sizeof(gpio));
		gpio &= ~pin;
		write(gpioouten, &gpio, sizeof(gpio));
		while (1) {
			read(gpioin, &gpio, sizeof(gpio));
			gpio=(gpio&pin)?1:0;
			if (gpio!=old_gpio) printf("%02X\n",gpio);
			old_gpio=gpio;
		}
	} else if (!strcmp(argv[1],"blink")) {
		int gpioout=open("/dev/gpio/out",O_RDWR);

		read(gpioouten, &gpio, sizeof(gpio));
		gpio |= pin;
		write(gpioouten, &gpio, sizeof(gpio));

		read(gpioout, &gpio, sizeof(gpio));
		while (1) {
			usleep(250000);

			gpio|=pin;
			write(gpioout, &gpio, sizeof(gpio));

			usleep(250000);

			gpio&=~pin;
			write(gpioout, &gpio, sizeof(gpio));
		}
	} else if (!strcmp(argv[1],"enable")||!strcmp(argv[1],"disable")) {
		int gpioout=open("/dev/gpio/out",O_RDWR);
		
		read(gpioouten, &gpio, sizeof(gpio));
		gpio |= pin;
		write(gpioouten, &gpio, sizeof(gpio));

		read(gpioout, &gpio, sizeof(gpio));
		if (!strcmp(argv[1],"enable")) {
			gpio|=pin;
		} else {
			gpio&=~pin;
		}
		write(gpioout, &gpio, sizeof(gpio));
	}

	return 0;
}