osd-contiki/cpu/avr/rtimer-arch.c

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/*
* Copyright (c) 2007, Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*
* $Id: rtimer-arch.c,v 1.1 2007/11/29 02:44:05 fros4943 Exp $
*/
/**
* \file
* AVR-specific rtimer code
* \author
* Fredrik Osterlind <fros@sics.se>
*/
/* OBS: 8 seconds maximum time! */
#include <avr/io.h>
#include <avr/interrupt.h>
#include "lib/energest.h"
#include "sys/rtimer.h"
#include "rtimer-arch.h"
/*---------------------------------------------------------------------------*/
SIGNAL (SIG_OUTPUT_COMPARE3A) {
ENERGEST_ON(ENERGEST_TYPE_IRQ);
ETIMSK &= ~((1 << OCIE3A) | (1 << OCIE3B) | (1 << TOIE3) |
(1 << TICIE3) | (1 << OCIE3C));
/* Call rtimer callback */
rtimer_run_next();
ENERGEST_OFF(ENERGEST_TYPE_IRQ);
}
/*---------------------------------------------------------------------------*/
void
rtimer_arch_init(void)
{
/* Disable interrupts (store old state) */
uint8_t sreg;
sreg = SREG;
cli ();
ETIMSK &= ~((1 << OCIE3A) | (1 << OCIE3B) | (1 << TOIE3) |
(1 << TICIE3) | (1 << OCIE3C));
ETIFR |= (1 << ICF3) | (1 << OCF3A) | (1 << OCF3B) | (1 << TOV3) |
(1 << OCF3C);
/* Default timer behaviour */
TCCR3A = 0;
TCCR3B = 0;
TCCR3C = 0;
/* Reset counter */
TCNT3 = 0;
/* Maximum prescaler */
TCCR3B |= 5;
/* Restore interrupt state */
SREG = sreg;
}
/*---------------------------------------------------------------------------*/
void
rtimer_arch_schedule(rtimer_clock_t t)
{
/* Disable interrupts (store old state) */
uint8_t sreg;
sreg = SREG;
cli ();
/* Set compare register */
OCR3A = t;
ETIFR |= (1 << ICF3) | (1 << OCF3A) | (1 << OCF3B) | (1 << TOV3) |
(1 << OCF3C);
ETIMSK |= (1 << OCIE3A);
/* Restore interrupt state */
SREG = sreg;
}