/* -*- mode: jde; c-basic-offset: 2; indent-tabs-mode: nil -*- */

/*
  Part of the Wiring project - http://wiring.uniandes.edu.co

  Copyright (c) 2004-05 Hernando Barragan

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General
  Public License along with this library; if not, write to the
  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  Boston, MA  02111-1307  USA
  
  Modified 24 November 2006 by David A. Mellis
  Modified 1 August 2010 by Mark Sproul
*/

#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/pgmspace.h>
#include <stdio.h>

#include "wiring_private.h"

static void nothing(void) {
}

static volatile voidFuncPtr intFunc[EXTERNAL_NUM_INTERRUPTS] = {
#if EXTERNAL_NUM_INTERRUPTS > 8
    #warning There are more than 8 external interrupts. Some callbacks may not be initialized.
    nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 7
    nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 6
    nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 5
    nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 4
    nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 3
    nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 2
    nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 1
    nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 0
    nothing,
#endif
};
// volatile static voidFuncPtr twiIntFunc;

void attachInterrupt(uint8_t interruptNum, void (*userFunc)(void), int mode) {
  if(interruptNum < EXTERNAL_NUM_INTERRUPTS) {
    intFunc[interruptNum] = userFunc;
    
    // Configure the interrupt mode (trigger on low input, any change, rising
    // edge, or falling edge).  The mode constants were chosen to correspond
    // to the configuration bits in the hardware register, so we simply shift
    // the mode into place.
      
    // Enable the interrupt.
      
    switch (interruptNum) {
#if defined(__AVR_ATmega32U4__)
	// I hate doing this, but the register assignment differs between the 1280/2560
	// and the 32U4.  Since avrlib defines registers PCMSK1 and PCMSK2 that aren't 
	// even present on the 32U4 this is the only way to distinguish between them.
    case 0:
	EICRA = (EICRA & ~((1<<ISC00) | (1<<ISC01))) | (mode << ISC00);
	EIMSK |= (1<<INT0);
	break;
    case 1:
	EICRA = (EICRA & ~((1<<ISC10) | (1<<ISC11))) | (mode << ISC10);
	EIMSK |= (1<<INT1);
	break;	
    case 2:
        EICRA = (EICRA & ~((1<<ISC20) | (1<<ISC21))) | (mode << ISC20);
        EIMSK |= (1<<INT2);
        break;
    case 3:
        EICRA = (EICRA & ~((1<<ISC30) | (1<<ISC31))) | (mode << ISC30);
        EIMSK |= (1<<INT3);
        break;
    case 4:
        EICRB = (EICRB & ~((1<<ISC60) | (1<<ISC61))) | (mode << ISC60);
        EIMSK |= (1<<INT6);
        break;
#elif defined(EICRA) && defined(EICRB) && defined(EIMSK)
    case 2:
      EICRA = (EICRA & ~((1 << ISC00) | (1 << ISC01))) | (mode << ISC00);
      EIMSK |= (1 << INT0);
      break;
    case 3:
      EICRA = (EICRA & ~((1 << ISC10) | (1 << ISC11))) | (mode << ISC10);
      EIMSK |= (1 << INT1);
      break;
    case 4:
      EICRA = (EICRA & ~((1 << ISC20) | (1 << ISC21))) | (mode << ISC20);
      EIMSK |= (1 << INT2);
      break;
    case 5:
      EICRA = (EICRA & ~((1 << ISC30) | (1 << ISC31))) | (mode << ISC30);
      EIMSK |= (1 << INT3);
      break;
    case 0:
      EICRB = (EICRB & ~((1 << ISC40) | (1 << ISC41))) | (mode << ISC40);
      EIMSK |= (1 << INT4);
      break;
    case 1:
      EICRB = (EICRB & ~((1 << ISC50) | (1 << ISC51))) | (mode << ISC50);
      EIMSK |= (1 << INT5);
      break;
    case 6:
      EICRB = (EICRB & ~((1 << ISC60) | (1 << ISC61))) | (mode << ISC60);
      EIMSK |= (1 << INT6);
      break;
    case 7:
      EICRB = (EICRB & ~((1 << ISC70) | (1 << ISC71))) | (mode << ISC70);
      EIMSK |= (1 << INT7);
      break;
#else		
    case 0:
    #if defined(EICRA) && defined(ISC00) && defined(EIMSK)
      EICRA = (EICRA & ~((1 << ISC00) | (1 << ISC01))) | (mode << ISC00);
      EIMSK |= (1 << INT0);
    #elif defined(MCUCR) && defined(ISC00) && defined(GICR)
      MCUCR = (MCUCR & ~((1 << ISC00) | (1 << ISC01))) | (mode << ISC00);
      GICR |= (1 << INT0);
    #elif defined(MCUCR) && defined(ISC00) && defined(GIMSK)
      MCUCR = (MCUCR & ~((1 << ISC00) | (1 << ISC01))) | (mode << ISC00);
      GIMSK |= (1 << INT0);
    #else
      #error attachInterrupt not finished for this CPU (case 0)
    #endif
      break;

    case 1:
    #if defined(EICRA) && defined(ISC10) && defined(ISC11) && defined(EIMSK)
      EICRA = (EICRA & ~((1 << ISC10) | (1 << ISC11))) | (mode << ISC10);
      EIMSK |= (1 << INT1);
    #elif defined(MCUCR) && defined(ISC10) && defined(ISC11) && defined(GICR)
      MCUCR = (MCUCR & ~((1 << ISC10) | (1 << ISC11))) | (mode << ISC10);
      GICR |= (1 << INT1);
    #elif defined(MCUCR) && defined(ISC10) && defined(GIMSK) && defined(GIMSK)
      MCUCR = (MCUCR & ~((1 << ISC10) | (1 << ISC11))) | (mode << ISC10);
      GIMSK |= (1 << INT1);
    #else
      #warning attachInterrupt may need some more work for this cpu (case 1)
    #endif
      break;
    
    case 2:
    #if defined(EICRA) && defined(ISC20) && defined(ISC21) && defined(EIMSK)
      EICRA = (EICRA & ~((1 << ISC20) | (1 << ISC21))) | (mode << ISC20);
      EIMSK |= (1 << INT2);
    #elif defined(MCUCR) && defined(ISC20) && defined(ISC21) && defined(GICR)
      MCUCR = (MCUCR & ~((1 << ISC20) | (1 << ISC21))) | (mode << ISC20);
      GICR |= (1 << INT2);
    #elif defined(MCUCR) && defined(ISC20) && defined(GIMSK) && defined(GIMSK)
      MCUCR = (MCUCR & ~((1 << ISC20) | (1 << ISC21))) | (mode << ISC20);
      GIMSK |= (1 << INT2);
    #endif
      break;
#endif
    }
  }
}

void detachInterrupt(uint8_t interruptNum) {
  if(interruptNum < EXTERNAL_NUM_INTERRUPTS) {
    // Disable the interrupt.  (We can't assume that interruptNum is equal
    // to the number of the EIMSK bit to clear, as this isn't true on the 
    // ATmega8.  There, INT0 is 6 and INT1 is 7.)
    switch (interruptNum) {
#if defined(__AVR_ATmega32U4__)
    case 0:
        EIMSK &= ~(1<<INT0);
        break;
    case 1:
        EIMSK &= ~(1<<INT1);
        break;
    case 2:
        EIMSK &= ~(1<<INT2);
        break;
    case 3:
        EIMSK &= ~(1<<INT3);
        break;	
    case 4:
        EIMSK &= ~(1<<INT6);
        break;	
#elif defined(EICRA) && defined(EICRB) && defined(EIMSK)
    case 2:
      EIMSK &= ~(1 << INT0);
      break;
    case 3:
      EIMSK &= ~(1 << INT1);
      break;
    case 4:
      EIMSK &= ~(1 << INT2);
      break;
    case 5:
      EIMSK &= ~(1 << INT3);
      break;
    case 0:
      EIMSK &= ~(1 << INT4);
      break;
    case 1:
      EIMSK &= ~(1 << INT5);
      break;
    case 6:
      EIMSK &= ~(1 << INT6);
      break;
    case 7:
      EIMSK &= ~(1 << INT7);
      break;
#else
    case 0:
    #if defined(EIMSK) && defined(INT0)
      EIMSK &= ~(1 << INT0);
    #elif defined(GICR) && defined(ISC00)
      GICR &= ~(1 << INT0); // atmega32
    #elif defined(GIMSK) && defined(INT0)
      GIMSK &= ~(1 << INT0);
    #else
      #error detachInterrupt not finished for this cpu
    #endif
      break;

    case 1:
    #if defined(EIMSK) && defined(INT1)
      EIMSK &= ~(1 << INT1);
    #elif defined(GICR) && defined(INT1)
      GICR &= ~(1 << INT1); // atmega32
    #elif defined(GIMSK) && defined(INT1)
      GIMSK &= ~(1 << INT1);
    #else
      #warning detachInterrupt may need some more work for this cpu (case 1)
    #endif
      break;
      
    case 2:
    #if defined(EIMSK) && defined(INT2)
      EIMSK &= ~(1 << INT2);
    #elif defined(GICR) && defined(INT2)
      GICR &= ~(1 << INT2); // atmega32
    #elif defined(GIMSK) && defined(INT2)
      GIMSK &= ~(1 << INT2);
    #elif defined(INT2)
      #warning detachInterrupt may need some more work for this cpu (case 2)
    #endif
      break;       
#endif
    }
      
    intFunc[interruptNum] = nothing;
  }
}

/*
void attachInterruptTwi(void (*userFunc)(void) ) {
  twiIntFunc = userFunc;
}
*/

#define IMPLEMENT_ISR(vect, interrupt) \
  ISR(vect) { \
    intFunc[interrupt](); \
  }

#if defined(__AVR_ATmega32U4__)

IMPLEMENT_ISR(INT0_vect, EXTERNAL_INT_0)
IMPLEMENT_ISR(INT1_vect, EXTERNAL_INT_1)
IMPLEMENT_ISR(INT2_vect, EXTERNAL_INT_2)
IMPLEMENT_ISR(INT3_vect, EXTERNAL_INT_3)
IMPLEMENT_ISR(INT6_vect, EXTERNAL_INT_4)

#elif defined(EICRA) && defined(EICRB)

IMPLEMENT_ISR(INT0_vect, EXTERNAL_INT_2)
IMPLEMENT_ISR(INT1_vect, EXTERNAL_INT_3)
IMPLEMENT_ISR(INT2_vect, EXTERNAL_INT_4)
IMPLEMENT_ISR(INT3_vect, EXTERNAL_INT_5)
IMPLEMENT_ISR(INT4_vect, EXTERNAL_INT_0)
IMPLEMENT_ISR(INT5_vect, EXTERNAL_INT_1)
IMPLEMENT_ISR(INT6_vect, EXTERNAL_INT_6)
IMPLEMENT_ISR(INT7_vect, EXTERNAL_INT_7)

#else

IMPLEMENT_ISR(INT0_vect, EXTERNAL_INT_0)
IMPLEMENT_ISR(INT1_vect, EXTERNAL_INT_1)

#if defined(EICRA) && defined(ISC20)
IMPLEMENT_ISR(INT2_vect, EXTERNAL_INT_2)
#endif

#endif

/*
ISR(TWI_vect) {
  if(twiIntFunc)
    twiIntFunc();
}
*/

