ben-blinkenlights/bbl/bbl.c

/*
 * bbl.c - Produce a "Knight Rider" effect on the LED board
 *
 * Written 2010 by Werner Almesberger <werner@openmoko.org>
 *  
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */


#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/mman.h>


#define	PDDATS	0x10010314
#define	PDDATC	0x10010318
#define	PDFUNC	0x10010348
#define	PDDIRS	0x10010364
#define	PDDIRC	0x10010368

#define	LEDS		10

#define	LED_MASK	0x3f00
#define	LED_SEL		11

#define	DELAY_US	50000

#define PAGE_SIZE 4096
#define	GPIO_BASE		0x10010000
#define	REG(n)	(*(uint32_t *) (mem+(n)-GPIO_BASE))

static volatile void *mem;


/* ----- Command-line parsing ---------------------------------------------- */


static int map(int g)
{
	switch (g) {
	case 0:
		return 12;
	case 1:
		return 13;
	case 2:
		return 8;
	case 3:
		return 9;
	case 4:
		return 10;
	default:
		abort();
	}
}


static void set(int n)
{
	
	if (n & 1) {
		REG(PDDATC) = LED_MASK;
		REG(PDDATS) = 1 << map(n >> 1);
	} else {
		REG(PDDATS) = LED_MASK;
		REG(PDDATC) = 1 << map(n >> 1);
	}
}


static void die(int sig)
{
	REG(PDDIRC) = LED_MASK;
	_exit(0);
}


int main(int argc, char **argv)
{
	int fd, i;

	fd = open("/dev/mem", O_RDWR);
        if (fd < 0) {
		perror("/dev/mem");
		exit(1);
	}
	mem = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
	    GPIO_BASE);
	if (mem == MAP_FAILED) {
		perror("mmap");
		exit(1);
	}

	signal(SIGINT, die);

	REG(PDFUNC) = LED_MASK;
	REG(PDDIRS) = LED_MASK;

	while (1) {
		for (i = 0; i != LEDS-1; i++) {
			set(i);
			usleep(DELAY_US);
		}
		for (i = LEDS-1; i != 0; i--) {
			set(i);
			usleep(DELAY_US);
		}
	}
	return 0;
}