interlock_channel.c

/*--------------------------------------------------------------------------
**
**  Copyright (c) 2003-2011, Tom Hunter
**
**  Name: interlock_channel.c
**
**  Description:
**      Perform emulation of interlock register on channel 15.
**
**  This program is free software: you can redistribute it and/or modify
**  it under the terms of the GNU General Public License version 3 as
**  published by the Free Software Foundation.
**  
**  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 version 3 for more details.
**  
**  You should have received a copy of the GNU General Public License
**  version 3 along with this program in file "license-gpl-3.0.txt".
**  If not, see <http://www.gnu.org/licenses/gpl-3.0.txt>.
**
**--------------------------------------------------------------------------
*/

#define DEBUG 0

/*
**  -------------
**  Include Files
**  -------------
*/
#include <stdio.h>
#include <stdlib.h>
#ifndef WIN32
#include <unistd.h>
#endif
#include <string.h>
#include "const.h"
#include "types.h"
#include "proto.h"

/*
**  -----------------
**  Private Constants
**  -----------------
*/
#define InterlockWords          11

/*
**  -----------------------
**  Private Macro Functions
**  -----------------------
*/

/*
**  -----------------------------------------
**  Private Typedef and Structure Definitions
**  -----------------------------------------
*/

/*
**  ---------------------------
**  Private Function Prototypes
**  ---------------------------
*/
static FcStatus ilrFunc(PpWord funcCode);
static void ilrIo(void);
static void ilrActivate(void);
static void ilrDisconnect(void);
static void ilrExecute(PpWord func);

/*
**  ----------------
**  Public Variables
**  ----------------
*/

/*
**  -----------------
**  Private Variables
**  -----------------
*/
static u8 ilrBits;
static u8 ilrWords;

#if DEBUG
static FILE *ilrLog = NULL;
#endif

/*
**--------------------------------------------------------------------------
**
**  Public Functions
**
**--------------------------------------------------------------------------
*/
/*--------------------------------------------------------------------------
**  Purpose:        Initialise interlock register channel.
**
**  Parameters:     Name        Description.
**
**  Returns:        Nothing.
**
**------------------------------------------------------------------------*/
void ilrInit(u8 registerSize)
    {
    DevSlot *dp;

#if DEBUG
    if (ilrLog == NULL)
        {
        ilrLog = fopen("ilrlog.txt", "wt");
        }
#endif

    dp = channelAttach(ChInterlock, 0, DtInterlockRegister);
    dp->activate = ilrActivate;
    dp->disconnect = ilrDisconnect;
    dp->func = ilrFunc;
    dp->io = ilrIo;

    channel[ChInterlock].active = TRUE;
    channel[ChInterlock].ioDevice = dp;
    channel[ChInterlock].hardwired = TRUE;

    ilrBits = registerSize;
    ilrWords = (ilrBits + 11) / 12;

    /*
    **  Print a friendly message.
    */
    printf("Interlock Register initialised on channel %o\n", ChInterlock);
    }

/*--------------------------------------------------------------------------
**  Purpose:        Execute function code on interlock register channel.
**
**  Parameters:     Name        Description.
**                  funcCode    function code
**
**  Returns:        FcStatus
**
**------------------------------------------------------------------------*/
static FcStatus ilrFunc(PpWord funcCode)
    {
    return(FcAccepted);
    }

/*--------------------------------------------------------------------------
**  Purpose:        Perform I/O on interlock register channel.
**
**  Parameters:     Name        Description.
**
**  Returns:        Nothing.
**
**------------------------------------------------------------------------*/
static void ilrIo(void)
    {
    /*
    **  This function relies on pp.c only calling it when doing the OAN. The
    **  IAN will not block as the response to the Interlock function request
    **  is made available immediately (i.e. the channel is full).
    */
    if (!activeChannel->inputPending && activeChannel->full)
        {
        activeChannel->inputPending = TRUE;
        ilrExecute(activeChannel->data);
        }
    }

/*--------------------------------------------------------------------------
**  Purpose:        Handle channel activation.
**
**  Parameters:     Name        Description.
**
**  Returns:        Nothing.
**
**------------------------------------------------------------------------*/
static void ilrActivate(void)
    {
    }

/*--------------------------------------------------------------------------
**  Purpose:        Handle disconnecting of channel.
**
**  Parameters:     Name        Description.
**
**  Returns:        Nothing.
**
**------------------------------------------------------------------------*/
static void ilrDisconnect(void)
    {
    }

/*--------------------------------------------------------------------------
**  Purpose:        Execute interlock register request.
**
**  Parameters:     Name        Description.
**                  func        function word
**
**  Returns:        Nothing.
**
**------------------------------------------------------------------------*/
static void ilrExecute(PpWord func)
    {
    static PpWord interlockRegister[InterlockWords] = {0};
    u8 code;
    u8 designator;
    u8 word;
    u8 bit;

    code = (func >> 9) & 7;
    designator = func & 0177;

    switch (code)
        {
    case 0:
        /*
        **  Read word.
        */
        if (designator < ilrWords)
            {
            activeChannel->data = interlockRegister[designator] & Mask12;
            }
        else
            {
            activeChannel->data = 0;
            }

        break;

    case 1:
        /*
        **  Test bit.
        */
        if (designator < ilrBits)
            {
            word = designator / 12;
            bit = designator % 12;

            activeChannel->data = (interlockRegister[word] & (1 << bit)) != 0 ? 1 : 0;
            }
        else
            {
            activeChannel->data = 0;
            }

        break;

    case 2:
        /*
        **  Clear bit.
        */
        if (designator < ilrBits)
            {
            word = designator / 12;
            bit = designator % 12;

            interlockRegister[word] &= ~(1 << bit);
            }

        activeChannel->data = 0;
        break;

    case 3:
        /*
        **  Test bit and leave clear.
        */
        if (designator < ilrBits)
            {
            word = designator / 12;
            bit = designator % 12;

            activeChannel->data = (interlockRegister[word] & (1 << bit)) != 0 ? 1 : 0;
            interlockRegister[word] &= ~(1 << bit);
            }
        else
            {
            activeChannel->data = 0;
            }

        break;

    case 4:
        /*
        **  Set bit.
        */
        if (designator < ilrBits)
            {
            word = designator / 12;
            bit = designator % 12;

            interlockRegister[word] |= (1 << bit);
            }

        activeChannel->data = 0;
        break;

    case 5:
        /*
        **  Test bit and leave set.
        */
        if (designator < ilrBits)
            {
            word = designator / 12;
            bit = designator % 12;

            activeChannel->data = (interlockRegister[word] & (1 << bit)) != 0 ? 1 : 0;
            interlockRegister[word] |= (1 << bit);
            }
        else
            {
            activeChannel->data = 0;
            }

        break;

    case 6:
        /*
        **  Clear all bits.
        */
        for (word = 0; word < ilrWords; word++)
            {
            interlockRegister[word] = 0;
            }

        activeChannel->data = 0;
        break;

    case 7:
        /*
        **  Test all bits and return one if any set.
        */
        activeChannel->data = 0;
        for (word = 0; word < ilrWords; word++)
            {
            if (interlockRegister[word] != 0)
                {
                activeChannel->data = 1;
                break;
                }
            }

        break;
        }

    activeChannel->full = TRUE;

#if DEBUG
    {
    static char *codeString[] =
        {
        "read word",
        "test bit",
        "clear bit",
        "test & clear bit",
        "set bit",
        "test & set bit",
        "clear all",
        "test all"
        };

    fprintf(ilrLog, "%06d Interlock Reg: bit %03o %s result: %04o\n", traceSequenceNo, designator, codeString[code], activeChannel->data);
    }
#endif
    }
    
/*---------------------------  End Of File  ------------------------------*/