/************************************************************************/
/*                                                                      */
/*  File:           avr/pcint.c                                         */
/*  Description:    pin change interruption driver.                     */
/*  Version:        1.0                                                 */
/*  Author:         Otto Mattik                                         */
/*                                                                      */
/*  (C)Copyright Otto Mattik 2014-2021.                                 */
/*                                                                      */
/*  This file is a part of 'armen' (a tiny operating system).           */
/*  'armen' is distributed under the CeCILL-V2.1 licence. For more      */
/*  details about this licence, please visit the website cecill.info    */
/*                                                                      */
/************************************************************************/

#ifndef AVR_GPIO_C
  #error "do not use this code directly, it must be included via gpio.c"
#endif

#include "avr/core.h"
#include <avr/interrupt.h>

#if defined(__AVR_ATtiny84__)
  #define GPIO_MAX_PCINT    2
  #define GPIO_MAX_INT      1
#elif defined(__AVR_ATtiny841__)
  #define GPIO_MAX_PCINT    2
  #define GPIO_MAX_INT      1
#elif defined(__AVR_ATtiny85__)
  #define GPIO_MAX_PCINT    1
  #define GPIO_MAX_INT      1
#elif defined(__AVR_ATtiny1634__)
  #define GPIO_MAX_PCINT    3
  #define GPIO_MAX_INT      1
#elif defined(__AVR_ATmega328P__)
  #define GPIO_MAX_PCINT    3
  #define GPIO_MAX_INT      2
#elif defined(__AVR_ATmega2560__)
  #define GPIO_MAX_PCINT    3
  #define GPIO_MAX_INT      3       /* really 8, limited to 3 by events mask */
#endif

static struct {
    uint8_t* pcmsk;
    uint8_t  pcie;
} pcints[GPIO_MAX_PCINT] = {
#if defined(__AVR_ATtiny85__)
    { 0x0015, 1<<PCIE0 }
#elif defined(__AVR_ATtiny84__)\
   || defined(__AVR_ATtiny841__)
    { 0x0032, 1<<PCIE0 },
    { 0x0040, 1<<PCIE1 }
#elif defined(__AVR_ATtiny1634__)
    { 0x0047, 1<<PCIE0 },
    { 0x0048, 1<<PCIE1 },
    { 0x0049, 1<<PCIE2 }
#elif defined(__AVR_ATmega328P__)\
   || defined(__AVR_ATmega2560__)
    { 0x006B, 1<<PCIE0 },
    { 0x006C, 1<<PCIE1 },
    { 0x006D, 1<<PCIE2 }
  #endif
};

/*
 * interrupt vectors
*/
ISR( INT0_vect )
{
    register uint8_t iflag;

    iflag = _disable_intr( );
#ifdef GIMSK
    if( (MCUCR & 0x03) == INT_LOW )
        GIMSK &= ~(1 << INT0);
#else
    if( (EICRA & 0x03) == INT_LOW )
        EIMSK &= ~1;
#endif
    _wakeup( EVENT_INT0, 0 );
    _enable_intr( iflag );
}

#if (GPIO_MAX_INT >= 2)
  ISR( INT1_vect )
  {
    register uint8_t iflag;

    iflag = _disable_intr( );
    if( (EICRA & 0x0C) == INT_LOW )
        EIMSK &= ~2;
    _wakeup( EVENT_INT1, 0 );
    _enable_intr( iflag );
  }
#endif
#if (GPIO_MAX_INT == 3)
  ISR( INT2_vect )
  {
    register uint8_t iflag;

    iflag = _disable_intr( );
    if( (EICRA & 0x30) == INT_LOW )
        EIMSK &= ~4;
    _wakeup( EVENT_INT2, 0 );
    _enable_intr( iflag );
  }
#endif

ISR( PCINT0_vect )
{
    register uint8_t iflag;

    iflag = _disable_intr( );
    _wakeup( EVENT_PCINT0, 0 );
    _enable_intr( iflag );
}

#ifndef PCINT_PER_PORT
  #if (GPIO_MAX_PCINT >= 2)
  ISR( PCINT1_vect, ISR_ALIASOF( PCINT0_vect ) );
  #endif
  #if (GPIO_MAX_PCINT == 3)
  ISR( PCINT2_vect, ISR_ALIASOF( PCINT0_vect ) );
  #endif
#else
  #if (GPIO_MAX_PCINT >= 2)
  ISR( PCINT1_vect )
  {
    register uint8_t iflag;

    iflag = _disable_intr( );
    _wakeup( EVENT_PCINT1, 0 );
    _enable_intr( iflag );
  }
  #endif
  #if (GPIO_MAX_PCINT == 3)
  ISR( PCINT2_vect )
  {
    register uint8_t iflag;

    iflag = _disable_intr( );
    _wakeup( EVENT_PCINT2, 0 );
    _enable_intr( iflag );
  }
  #endif
#endif

/*
 * enable/disable interrupt on gpio pin change
 *
 * input:
 *  interrupt   interrupt number (0, 1, 2)
 *  mode        interrupt mode (LOW, CHANGE, RISING, FALLING, DISABLE)
*/
void gpio_int_enable( uint8_t interrupt, uint8_t mode )
{
#ifdef CHECK_PARAM
    if( interrupt < GPIO_MAX_INT && mode <= INT_DISABLE )
#endif
    {
        if( mode == INT_DISABLE )
/*
#if defined(__AVR_ATtiny84__)\
 || defined(__AVR_ATtiny85__)\
 || defined(__AVR_ATtiny841__)\
 || defined(__AVR_ATtiny1634__)
*/
#ifdef GIMSK
            GIMSK &= ~(1 << INT0);
        else
        {
            MCUCR |= mode;
            GIMSK |= (1 << INT0);
        }
#else
            EIMSK &= ~(1 << interrupt);
        else
        {
  #if 0
  #if defined(__AVR_ATmega2560__)
            if( interrupt >= 4 )
                EICRB |= (mode << (interrupt-4));
            else
  #endif
  #endif
                EICRA |= (mode << interrupt);
            EIMSK |= (1 << interrupt);
        }
#endif
    }
}

/*
 * enable/disable interrupt on gpio pin change
 *
 * input:
 *  gpio        gpio pin
 *  enable      true or false
*/
void gpio_pcint_enable( uint8_t gpio, uint8_t enable )
{
#ifdef CHECK_PARAM
    if( gpio < (GPIO_MAX_PORT << 3) )
#endif
    {
#if defined(__AVR_ATtiny1634__)
        if( gpio > 11 )
            gpio += 4;
        if( gpio < 22 )
#elif defined(__AVR_ATmega328P__)
        if( gpio != 15 )
#elif defined(__AVR_ATmega2560__)
        if( gpio >= 8 && gpio <= 15 )
            gpio -= 8;
        else if( gpio == 32 )
            gpio = 8;
        else if( gpio >= 64 && gpio <= 70 )
            gpio -= 55;
        else if( gpio >= 72 && gpio <= 79 )
            gpio -= 56;
        else
            return;
#endif
        {
            uint8_t port = gpio >> 3;
            uint8_t mask = 1 << (gpio & 7);

            if( enable != 0 )
            {
                *pcints[port].pcmsk |= mask;
/*
#if defined(__AVR_ATtiny84__)\
 || defined(__AVR_ATtiny85__)\
 || defined(__AVR_ATtiny841__)\
 || defined(__AVR_ATtiny1634__)
*/
#ifdef GIMSK
                GIMSK |= pcints[port].pcie;
#else
                PCICR |= pcints[port].pcie;
#endif
            }
            else
                *pcints[port].pcmsk &= ~mask;
        }
    }
}