/*
 * plus4tcbm.c
 *
 * Written by
 *  Andreas Boose <viceteam@t-online.de>
 *
 * This file is part of VICE, the Versatile Commodore Emulator.
 * See README for copyright notice.
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA.
 *
 */

#include "vice.h"

#include "drive.h"
#include "drivecpu.h"
#include "drivetypes.h"
#include "iecdrive.h"
#include "log.h"
#include "maincpu.h"
#include "plus4tcbm.h"
#include "tcbm.h"
#include "types.h"


/*#define TCBM_DEBUG*/


typedef struct tiatcbm_s {
    BYTE ddra;
    BYTE dataa;
    BYTE ddrb;
    BYTE datab;
    BYTE ddrc;
    BYTE datac;
} tiatcbm_t;

static tiatcbm_t tiatcbm[2];

BYTE plus4tcbm_outputa[2], plus4tcbm_outputb[2], plus4tcbm_outputc[2];
BYTE tpid_outputa[2], tpid_outputb[2], tpid_outputc[2];

/*-----------------------------------------------------------------------*/

void plus4tcbm_update_pa(BYTE byte, unsigned int dnr)
{
    tpid_outputa[dnr] = byte;
}

void plus4tcbm_update_pb(BYTE byte, unsigned int dnr)
{
    tpid_outputb[dnr] = byte;
}

void plus4tcbm_update_pc(BYTE byte, unsigned int dnr)
{
    tpid_outputc[dnr] = byte;
}

/*-----------------------------------------------------------------------*/

inline static BYTE dataa_read(unsigned int dnr)
{
#ifdef TCBM_DEBUG
    log_debug("TCBM PA READ DATA %02x DDR %02x TIPD %02x",
              tiatcbm[dnr].dataa, tiatcbm[dnr].ddra, tpid_outputa[dnr]);
#endif
    return (tiatcbm[dnr].dataa | ~tiatcbm[dnr].ddra) & tpid_outputa[dnr];
}

inline static BYTE datab_read(unsigned int dnr)
{
#ifdef TCBM_DEBUG
    log_debug("TCBM PB READ DATA %02x DDR %02x",
              tiatcbm[dnr].datab, tiatcbm[dnr].ddrb);
#endif
    return (tiatcbm[dnr].datab | ~tiatcbm[dnr].ddrb)
           & (tpid_outputc[dnr] | 0xfc);
}

inline static BYTE datac_read(unsigned int dnr)
{
#ifdef TCBM_DEBUG
    log_debug("TCBM PC READ DATA %02x DDR %02x",
              tiatcbm[dnr].datac, tiatcbm[dnr].ddrc);
#endif
    return (tiatcbm[dnr].datac | ~tiatcbm[dnr].ddrc)
           & ((tpid_outputc[dnr] << 4) | 0x7f)
           & ((tpid_outputc[dnr] >> 1) | 0xbf);
}

inline static void store_pa(unsigned int dnr)
{
#ifdef TCBM_DEBUG
    log_debug("TCBM PA STORE DATA %02x DDR %02x",
              tiatcbm[dnr].dataa, tiatcbm[dnr].ddra);
#endif
    plus4tcbm_outputa[dnr] = tiatcbm[dnr].dataa | ~tiatcbm[dnr].ddra;
}

inline static void store_pb(unsigned int dnr)
{
#ifdef TCBM_DEBUG
    log_debug("TCBM PB STORE DATA %02x DDR %02x",
              tiatcbm[dnr].datab, tiatcbm[dnr].ddrb);
#endif
    plus4tcbm_outputb[dnr] = tiatcbm[dnr].datab | ~tiatcbm[dnr].ddrb;
}

inline static void store_pc(unsigned int dnr)
{
#ifdef TCBM_DEBUG
    log_debug("TCBM PC STORE DATA %02x DDR %02x",
              tiatcbm[dnr].datac, tiatcbm[dnr].ddrc);
#endif

    plus4tcbm_outputc[dnr] = tiatcbm[dnr].datac | ~tiatcbm[dnr].ddrc;
}

/*-----------------------------------------------------------------------*/

static void tiatcbm_reset(unsigned int dnr)
{
    tiatcbm[dnr].ddra = 0;
    tiatcbm[dnr].dataa = 0;
    tiatcbm[dnr].ddrb = 0;
    tiatcbm[dnr].datab = 0;
    tiatcbm[dnr].ddrc = 0;
    tiatcbm[dnr].datac = 0;
    plus4tcbm_outputa[dnr] = 0xff;
    plus4tcbm_outputb[dnr] = 0xff;
    plus4tcbm_outputc[dnr] = 0xff;
}

void plus4tcbm1_reset(void)
{
    tiatcbm_reset(0);
}

void plus4tcbm2_reset(void)
{
    tiatcbm_reset(1);
}

static void tiatcbm_store(WORD addr, BYTE byte, unsigned int dnr)
{
    switch (addr & 7) {
      case 0:
        tiatcbm[dnr].dataa = byte;
        store_pa(dnr);
        break;
      case 1:
        tiatcbm[dnr].datab = byte;
        store_pb(dnr);
        break;
      case 2:
        tiatcbm[dnr].datac = byte;
        store_pc(dnr);
        break;
      case 3:
        tiatcbm[dnr].ddra = byte;
        store_pa(dnr);
        break;
      case 4:
        tiatcbm[dnr].ddrb = byte;
        store_pb(dnr);
        break;
      case 5:
        tiatcbm[dnr].ddrc = byte;
        store_pc(dnr);
        break;
    }
}

static BYTE tiatcbm_read(WORD addr, unsigned int dnr)
{
    switch (addr & 7) {
      case 0:
        return dataa_read(dnr);
      case 1:
        return datab_read(dnr);
      case 2:
        return datac_read(dnr);
      case 3:
        return tiatcbm[dnr].ddra;
      case 4:
        return tiatcbm[dnr].ddrb;
      case 5:
        return tiatcbm[dnr].ddrc;
    }

    return 0xff;
}

/*-----------------------------------------------------------------------*/

BYTE REGPARM1 plus4tcbm1_read(WORD addr)
{
    if (drive_context[0]->drive->enable
        && drive_context[0]->drive->type == DRIVE_TYPE_1551) {
        drivecpu_execute(drive_context[0], maincpu_clk);
        return tiatcbm_read(addr, 0);
    }
    return 0;
}

void REGPARM2 plus4tcbm1_store(WORD addr, BYTE value)
{
    if (drive_context[0]->drive->enable
        && drive_context[0]->drive->type == DRIVE_TYPE_1551) {
        drivecpu_execute(drive_context[0], maincpu_clk);
        tiatcbm_store(addr, value, 0);
    }
}

BYTE REGPARM1 plus4tcbm2_read(WORD addr)
{
    if (drive_context[1]->drive->enable
        && drive_context[1]->drive->type == DRIVE_TYPE_1551) {
        drivecpu_execute(drive_context[1], maincpu_clk);
        return tiatcbm_read(addr, 1);
    }
    return 0;
}

void REGPARM2 plus4tcbm2_store(WORD addr, BYTE value)
{
    if (drive_context[1]->drive->enable
        && drive_context[1]->drive->type == DRIVE_TYPE_1551) {
        drivecpu_execute(drive_context[1], maincpu_clk);
        tiatcbm_store(addr, value, 1);
    }
}

