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/* $Id$ */
/*
 * Copyright (c) 2011 Dimitri Sokolyuk <demon@dim13.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <inttypes.h>
#include <avr/io.h>
#include "kernel.h"
#include "tasks.h"

#define MUXMASK	0x07

uint16_t
rdadc(uint8_t ch)
{
	ADMUX &= ~MUXMASK;
	ADMUX |= (ch & MUXMASK);
	ADCSRA |= _BV(ADSC);
	loop_until_bit_is_clear(ADCSRA, ADSC);

	return ADCW;
}

void
adc(void *arg)
{
	struct adcarg *a = (struct adcarg *)arg;
	uint32_t r = release();
	uint32_t d = deadline();
	uint16_t v;
	uint8_t i;

	ADCSRA |= (_BV(ADEN) | ADC_FLAGS);
//	ADMUX |= _BV(REFS0);

	for (;;) {
		wait(0);
		for (i = 0; i < ADCCHANNELS; i++)
			a->value[i] = rdadc(i);
		signal(0);
		r = d;
		d += MSEC(10) * ADCCHANNELS;
		update(r, d);
	}
}