/**

 * $Id$

 *

 * Implements the ARM's memory map.

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * 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.

 */

#include <stdlib.h>

#include "dream.h"

#include "mem.h"

#include "aica.h"

unsigned char *arm_mem = NULL;

unsigned char *arm_mem_scratch = NULL;

void arm_mem_init() {

    arm_mem = mem_get_region_by_name( MEM_REGION_AUDIO );

    arm_mem_scratch = mem_get_region_by_name( MEM_REGION_AUDIO_SCRATCH );

}

int arm_has_page( uint32_t addr ) {

    return ( addr < 0x00200000 ||

            (addr >= 0x00800000 && addr <= 0x00805000 ) );

}

uint32_t arm_read_long( uint32_t addr ) {

    if( addr < 0x00200000 ) {

        return *(int32_t *)(arm_mem + addr);

        /* Main sound ram */

    } else {

        uint32_t val;

        switch( addr & 0xFFFFF000 ) {

        case 0x00800000:

            val = mmio_region_AICA0_read(addr&0x0FFF);

            //	    DEBUG( "ARM long read from %08X => %08X", addr, val );

            return val;

        case 0x00801000:

            val = mmio_region_AICA1_read(addr&0x0FFF);

            //	    DEBUG( "ARM long read from %08X => %08X", addr, val );

            return val;

        case 0x00802000:

            val = mmio_region_AICA2_read(addr&0x0FFF);

            // DEBUG( "ARM long read from %08X => %08X", addr, val );

            return val;

        case 0x00803000:

        case 0x00804000:

            return *(int32_t *)(arm_mem_scratch + addr - 0x00803000);

        }

    }

    ERROR( "Attempted long read to undefined page: %08X",

           addr );

    /* Undefined memory */

    return 0;

}

uint32_t arm_read_word( uint32_t addr ) {

    return (uint32_t)(uint16_t)arm_read_long( addr );

}

uint32_t arm_read_byte( uint32_t addr ) {

    return (uint32_t)(uint8_t)arm_read_long( addr );

}

void arm_write_long( uint32_t addr, uint32_t value )

{

    if( addr < 0x00200000 ) {

        /* Main sound ram */

        *(uint32_t *)(arm_mem + addr) = value;

    } else {

        switch( addr & 0xFFFFF000 ) {

        case 0x00800000:

            // DEBUG( "ARM long write to %08X <= %08X", addr, value );

            mmio_region_AICA0_write(addr&0x0FFF, value);

            break;

        case 0x00801000:

            // DEBUG( "ARM long write to %08X <= %08X", addr, value );

            mmio_region_AICA1_write(addr&0x0FFF, value);

            break;

        case 0x00802000:

            // DEBUG( "ARM long write to %08X <= %08X", addr, value );

            mmio_region_AICA2_write(addr&0x0FFF, value);

            break;

        case 0x00803000:

        case 0x00804000:

            *(uint32_t *)(arm_mem_scratch + addr - 0x00803000) = value;

            break;

        default:

            ERROR( "Attempted long write to undefined address: %08X",

                    addr );

            /* Undefined memory */

        } 

    }

    return;

}

uint32_t arm_combine_byte( uint32_t addr, uint32_t val, uint8_t byte )

{

    switch( addr & 0x03 ) {

    case 0:

        return (val & 0xFFFFFF00) | byte;

    case 1:

        return (val & 0xFFFF00FF) | (byte<<8);

    case 2:

        return (val & 0xFF00FFFF) | (byte<<16);

    case 3:

        return (val & 0x00FFFFFF) | (byte<<24);

    default:

        return val; // Can't happen, but make gcc happy

    }

}

void arm_write_byte( uint32_t addr, uint32_t value )

{

    if( addr < 0x00200000 ) {

        /* Main sound ram */

        *(uint8_t *)(arm_mem + addr) = (uint8_t)value;

    } else {

        uint32_t tmp;

        switch( addr & 0xFFFFF000 ) {

        case 0x00800000:

            tmp = MMIO_READ( AICA0, addr & 0x0FFC );

            value = arm_combine_byte( addr, tmp, value );

            mmio_region_AICA0_write(addr&0x0FFC, value);

            break;

        case 0x00801000:

            tmp = MMIO_READ( AICA1, addr & 0x0FFC );

            value = arm_combine_byte( addr, tmp, value );

            mmio_region_AICA1_write(addr&0x0FFC, value);

            break;

        case 0x00802000:

            tmp = MMIO_READ( AICA2, addr & 0x0FFC );

            value = arm_combine_byte( addr, tmp, value );

            mmio_region_AICA2_write(addr&0x0FFC, value);

            break;

        case 0x00803000:

        case 0x00804000:

            *(uint8_t *)(arm_mem_scratch + addr - 0x00803000) = (uint8_t)value;

            break;

        default:

            ERROR( "Attempted byte write to undefined address: %08X",

                    addr );

            /* Undefined memory */

        } 

    }

    return;

}

/* User translations - TODO */

uint32_t arm_read_long_user( uint32_t addr ) {

    return arm_read_long( addr );

}

uint32_t arm_read_byte_user( uint32_t addr ) {

    return arm_read_byte( addr );

}

void arm_write_long_user( uint32_t addr, uint32_t val ) {

    arm_write_long( addr, val );

}

void arm_write_byte_user( uint32_t addr, uint32_t val )

{

    arm_write_byte( addr, val );

}