checkdevice.c

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/*
 *  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.
 *
 *  Copyright 1997-2005 Joe Forster <sta(at)c64(dot)org>
 *  Copyright 1997-2005 Wolfgang Moser (http://d81.de)
 *  Copyright      2005 Spiro Trikaliotis
 *
 */

#include <wdm.h>
#include "cbm_driver.h"
#include "i_iec.h"

NTSTATUS
cbmiec_check_device(IN PDEVICE_EXTENSION Pdx, OUT IEC_CHECKDEVICE *CheckDevice)
{
    FUNC_ENTER();

    DBG_ASSERT(CheckDevice != NULL);

    do
    {
        CBMIEC_RELEASE(PP_ATN_OUT | PP_CLK_OUT | PP_DATA_OUT | PP_RESET_OUT);

        // wait for the drive to have time to react
        cbmiec_schedule_timeout(100);

        // assert ATN
        CBMIEC_SET(PP_ATN_OUT);

        // now, wait for the drive to have time to react
        cbmiec_schedule_timeout(100);

        // if DATA is still unset, we have a problem.
        if (!CBMIEC_GET(PP_DATA_IN))
        {
            *CheckDevice = IEC_CHECKDEVICE_NODEVICE;
            break;
        }

        // ok, at least one drive reacted. Now, test releasing ATN:

        CBMIEC_RELEASE(PP_ATN_OUT);
        cbmiec_schedule_timeout(100);

        if (!CBMIEC_GET(PP_DATA_IN))
            *CheckDevice = IEC_CHECKDEVICE_BUSFREE;
        else
            *CheckDevice = IEC_CHECKDEVICE_BUSBUSY;

    } while (FALSE);

    CBMIEC_RELEASE(PP_ATN_OUT | PP_CLK_OUT | PP_DATA_OUT | PP_RESET_OUT);

    FUNC_LEAVE_NTSTATUS_CONST(STATUS_SUCCESS);
}