/*
 * cia1571d.c - Definitions for the MOS6526 (CIA) chip in the 1571
 * disk drive ($4000).
 *
 * 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 <stdio.h>

#include "cia.h"
#include "ciad.h"
#include "drivetypes.h"
#include "iecdrive.h"
#include "interrupt.h"
#include "lib.h"
#include "log.h"
#include "types.h"


typedef struct drivecia1571_context_s {
    unsigned int number;
    struct diskunit_context_s *diskunit;
} drivecia1571_context_t;


void cia1571_store(diskunit_context_t *ctxptr, uint16_t addr, uint8_t data)
{
    ctxptr->cpu->cpu_last_data = data;
    ciacore_store(ctxptr->cia1571, addr, data);
}

uint8_t cia1571_read(diskunit_context_t *ctxptr, uint16_t addr)
{
    return ctxptr->cpu->cpu_last_data = ciacore_read(ctxptr->cia1571, addr);
}

uint8_t cia1571_peek(diskunit_context_t *ctxptr, uint16_t addr)
{
    return ciacore_peek(ctxptr->cia1571, addr);
}

int cia1571_dump(diskunit_context_t *ctxptr, uint16_t addr)
{
    ciacore_dump(ctxptr->cia1571);
    return 0;
}

/*
    FIXME: the actual memory map is quite wild with the mos5710:

       A 15 14 13 12   10    4    3
    CIA   0  1  0  0    x    0    x     4x0x 4x2x 4x4x 4x6x 4x8x 4xax 4xcx 4xex
    FDC2  0  1  0  0    0    1    x     401x 403x 405x 407x 409x 40bx 40dx 40fx
                                        411x 413x 415x 417x 419x 41bx 41dx 41fx
                                        421x 423x 425x 427x 429x 42bx 42dx 42fx
                                        431x 433x 435x 437x 439x 43bx 43dx 43fx
                                        481x 483x 485x 487x 489x 48bx 48dx 48fx
                                        491x 493x 495x 497x 499x 49bx 49dx 49fx
                                        4a1x 4a3x 4a5x 4a7x 4a9x 4abx 4adx 4afx
                                        4b1x 4b3x 4b5x 4b7x 4b9x 4bbx 4bdx 4bfx
*/
/* FIXME: need to confirm how it actually mirrors on the real drive */
void mos5710_store(diskunit_context_t *ctxptr, uint16_t addr, uint8_t data)
{
    if ((addr & 0x1f) > 0x0f) {
        /* TODO: extra MFM registers */
    } else {
        /* HACK HACK: (partially) implemented are registers 0x0c, 0x0d, 0x0e */
        ctxptr->cpu->cpu_last_data = data;
        /* the following lets us use the regular CIA emulation */
        switch (addr & 0x0f) {
            case 0x0c:
                break;
            case 0x0d:
                if (data & 0x80) {
                    data &= 0x88;   /* only allow SR IRQ */
                }
                break;
            case 0x0e:
                data &= 0x40;   /* only SR Input/Output is implemented (?) */
                data |= 0x01;   /* force timer running */
                break;
            default:
                return; /* all other registers are not implemented */
        }
        ciacore_store(ctxptr->cia1571, addr & 0x0f, data);
    }
}

/* FIXME: need to confirm how it actually mirrors on the real drive */
uint8_t mos5710_read(diskunit_context_t *ctxptr, uint16_t addr)
{
    if ((addr & 0x1f) > 0x0f) {
        /* TODO: extra MFM registers */
        return ctxptr->cpu->cpu_last_data = 0;
    }

    /* the following lets us use the regular CIA emulation */
    switch (addr & 0x0f) {
        case 0x0c:
        case 0x0d:
        case 0x0e:
            break;
        default:
            return 0xff; /* FIXME: all other registers are not implemented */
    }

    return ctxptr->cpu->cpu_last_data = ciacore_read(ctxptr->cia1571, addr & 0x0f);
}

/* FIXME: need to confirm how it actually mirrors on the real drive */
uint8_t mos5710_peek(diskunit_context_t *ctxptr, uint16_t addr)
{
    if ((addr & 0x1f) > 0x0f) {
        /* TODO: extra MFM registers */
        return 0;
    }

    /* the following lets us use the regular CIA emulation */
    switch (addr & 0x0f) {
        case 0x0c:
        case 0x0d:
        case 0x0e:
            break;
        default:
            return 0xff; /* FIXME: all other registers are not implemented */
    }

    return ciacore_peek(ctxptr->cia1571, addr & 0x0f);
}

int mos5710_dump(diskunit_context_t *ctxptr, uint16_t addr)
{
    ciacore_dump(ctxptr->cia1571);
    /* TODO: extra MFM registers */
    return 0;
}

static void cia_set_int_clk(cia_context_t *cia_context, int value, CLOCK clk)
{
    diskunit_context_t *dc;

    dc = (diskunit_context_t *)(cia_context->context);

    interrupt_set_irq(dc->cpu->int_status, cia_context->int_num,
                      value, clk);
}

static void cia_restore_int(cia_context_t *cia_context, int value)
{
    diskunit_context_t *dc;

    dc = (diskunit_context_t *)(cia_context->context);

    interrupt_restore_irq(dc->cpu->int_status, (int)(cia_context->int_num), value);
}


/*************************************************************************
 * Hardware binding
 */

static void do_reset_cia(cia_context_t *cia_context)
{
}

static void pulse_ciapc(cia_context_t *cia_context, CLOCK rclk)
{
    drivecia1571_context_t *ciap;

    ciap = (drivecia1571_context_t *)(cia_context->prv);

    if (ciap->diskunit->parallel_cable == DRIVE_PC_STANDARD) {
        parallel_cable_drive_write(DRIVE_PC_STANDARD, 0, PARALLEL_HS, ciap->number);
    }
}

static void undump_ciapa(cia_context_t *cia_context, CLOCK rclk, uint8_t byte)
{
}

static void undump_ciapb(cia_context_t *cia_context, CLOCK rclk, uint8_t byte)
{
    drivecia1571_context_t *ciap;

    ciap = (drivecia1571_context_t *)(cia_context->prv);

    if (ciap->diskunit->parallel_cable == DRIVE_PC_STANDARD) {
        parallel_cable_drive_write(DRIVE_PC_STANDARD, byte, PARALLEL_WRITE, ciap->number);
    }
}

static void store_ciapa(cia_context_t *cia_context, CLOCK rclk, uint8_t byte)
{
}

static void store_ciapb(cia_context_t *cia_context, CLOCK rclk, uint8_t byte)
{
    drivecia1571_context_t *ciap;

    ciap = (drivecia1571_context_t *)(cia_context->prv);

    if (ciap->diskunit->parallel_cable == DRIVE_PC_STANDARD) {
        parallel_cable_drive_write(DRIVE_PC_STANDARD, byte, PARALLEL_WRITE, ciap->number);
    }
}

static uint8_t read_ciapa(cia_context_t *cia_context)
{
    return (uint8_t)((0xff & ~(cia_context->c_cia[CIA_DDRA]))
            | (cia_context->c_cia[CIA_PRA] & cia_context->c_cia[CIA_DDRA]));
}

static uint8_t read_ciapb(cia_context_t *cia_context)
{
    drivecia1571_context_t *ciap;
    uint8_t byte = 0xff;

    ciap = (drivecia1571_context_t *)(cia_context->prv);

    if (ciap->diskunit->parallel_cable == DRIVE_PC_STANDARD) {
        byte = parallel_cable_drive_read(ciap->diskunit->parallel_cable, 1);
    }

    return (uint8_t)((byte & ~(cia_context->c_cia[CIA_DDRB]))
            | (cia_context->c_cia[CIA_PRB] & cia_context->c_cia[CIA_DDRB]));
}

static void read_ciaicr(cia_context_t *cia_context)
{
}

static void read_sdr(cia_context_t *cia_context)
{
}

static void store_sdr(cia_context_t *cia_context, uint8_t byte)
{
    drivecia1571_context_t *cia1571p;

    cia1571p = (drivecia1571_context_t *)(cia_context->prv);

    iec_fast_drive_write((uint8_t)byte, cia1571p->number);
}

void cia1571_init(diskunit_context_t *ctxptr)
{
    ciacore_init(ctxptr->cia1571, ctxptr->cpu->alarm_context,
                 ctxptr->cpu->int_status);
}

void cia1571_setup_context(diskunit_context_t *ctxptr)
{
    drivecia1571_context_t *cia1571p;
    cia_context_t *cia;

    ctxptr->cia1571 = lib_calloc(1, sizeof(cia_context_t));
    cia = ctxptr->cia1571;

    cia->prv = lib_malloc(sizeof(drivecia1571_context_t));
    cia1571p = (drivecia1571_context_t *)(cia->prv);
    cia1571p->number = ctxptr->mynumber;

    cia->context = (void *)ctxptr;

    cia->rmw_flag = &(ctxptr->cpu->rmw_flag);
    cia->clk_ptr = ctxptr->clk_ptr;

    cia1571_set_timing(cia, 1000000, 50);

    ciacore_setup_context(cia);

    cia->debugFlag = 0;
    cia->irq_line = IK_IRQ;
    cia->myname = lib_msprintf("CIA1571D%u", ctxptr->mynumber);

    cia1571p->diskunit = ctxptr;

    cia->undump_ciapa = undump_ciapa;
    cia->undump_ciapb = undump_ciapb;
    cia->store_ciapa = store_ciapa;
    cia->store_ciapb = store_ciapb;
    cia->store_sdr = store_sdr;
    cia->read_ciapa = read_ciapa;
    cia->read_ciapb = read_ciapb;
    cia->read_ciaicr = read_ciaicr;
    cia->read_sdr = read_sdr;
    cia->cia_set_int_clk = cia_set_int_clk;
    cia->cia_restore_int = cia_restore_int;
    cia->do_reset_cia = do_reset_cia;
    cia->pulse_ciapc = pulse_ciapc;
    cia->pre_store = NULL;
    cia->pre_read = NULL;
    cia->pre_peek = NULL;
}

void cia1571_set_timing(cia_context_t *cia_context, int tickspersec, int powerfreq)
{
    cia_context->power_freq = powerfreq;
    cia_context->ticks_per_sec = (unsigned int)tickspersec;
    cia_context->todticks = tickspersec / powerfreq;
    cia_context->power_tickcounter = 0;
    cia_context->power_ticks = 0;
}