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/* button.c */
/* binwatch - Tiny binary wristwatch. {{{
 *
 * Copyright (C) 2010 Nicolas Schodet
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Contact :
 *        Web: http://ni.fr.eu.org/
 *      Email: <nico at ni.fr.eu.org>
 * }}} */
#include "common.h"
#include "modules/utils/utils.h"
#include "io.h"
#include "button.h"
#include "led.h"
#include "power.h"

/** Delay for the button to be considered debounced. */
#define BUTTON_DEBOUNCE_MS 100

void
button_init (void)
{
    /* Initialise pin change interrupt. */
    GIMSK |= _BV (PCIE);
    PCMSK = IO_BV (BUTTON_IO);
    /* Button is shared with leds, no PORT init. */
}

void
button_wait (void)
{
    /* Wait until button is pressed. */
    GIFR = _BV (PCIF); /* Clear previous interrupt. */
    if (IO_GET (BUTTON_IO))
      {
	/* Sleep, the pin change interrupt will wake me up. */
	power_sleep ();
      }
    /* Remove pull-up to save battery and shut off leds. */
    led_no_pull_up ();
    /* Wait until button is really released. */
    uint8_t debounce_ms = 0;
    while (debounce_ms < BUTTON_DEBOUNCE_MS)
      {
	power_delay_ms (1);
	if (IO_GET (BUTTON_IO))
	    debounce_ms++;
	else
	    debounce_ms = 0;
      }
}

SIGNAL (PCINT0_vect)
{
    /* Nothing to do, only wake up. */
}