/*++

Copyright (C) Microsoft Corporation, 1996 - 1999

Module Name:

    adicsc.c

Abstract:

    This module contains device-specific routines for the ADIC Scalar medium changers:
    ADIC Scalar 218,224,448, 458.

Environment:

    kernel mode only

Revision History:


--*/

#include "ntddk.h"
#include "mcd.h"
#include "adicsc.h"


#define ADIC_SCALAR  1

typedef struct _CHANGER_ADDRESS_MAPPING {

    //
    // Indicates the first element for each element type.
    // Used to map device-specific values into the 0-based
    // values that layers above expect.
    //

    USHORT  FirstElement[ChangerMaxElement];

    //
    // Indicates the number of each element type.
    //

    USHORT  NumberOfElements[ChangerMaxElement];

    //
    // Indicates that the address mapping has been
    // completed successfully.
    //

    BOOLEAN Initialized;

} CHANGER_ADDRESS_MAPPING, *PCHANGER_ADDRESS_MAPPING;

typedef struct _CHANGER_DATA {

    //
    // Size, in bytes, of the structure.
    //

    ULONG Size;

    //
    // Unique identifier for the supported models. See above.
    //

    ULONG DriveID;

    //
    // See Address mapping structure above.
    //

    CHANGER_ADDRESS_MAPPING AddressMapping;

    //
    // Cached inquiry data.
    //

    INQUIRYDATA InquiryData;

} CHANGER_DATA, *PCHANGER_DATA;



NTSTATUS
AdicBuildAddressMapping(
    IN PDEVICE_OBJECT DeviceObject
    );

ULONG
MapExceptionCodes(
    IN PADICS_ELEMENT_DESCRIPTOR ElementDescriptor
    );

BOOLEAN
ElementOutOfRange(
    IN PCHANGER_ADDRESS_MAPPING AddressMap,
    IN USHORT ElementOrdinal,
    IN ELEMENT_TYPE ElementType
    );


ULONG
ChangerAdditionalExtensionSize(
    VOID
    )

/*++

Routine Description:

    This routine returns the additional device extension size
    needed by the ADIC Scalar changers.

Arguments:


Return Value:

    Size, in bytes.

--*/

{

    return sizeof(CHANGER_DATA);
}


NTSTATUS
ChangerInitialize(
    IN PDEVICE_OBJECT DeviceObject
    )
{
    PFUNCTIONAL_DEVICE_EXTENSION fdoExtension = DeviceObject->DeviceExtension;
    PCHANGER_DATA  changerData = (PCHANGER_DATA)(fdoExtension->CommonExtension.DriverData);
    NTSTATUS       status;
    PINQUIRYDATA   dataBuffer;
    PCDB           cdb;
    ULONG          length;
    SCSI_REQUEST_BLOCK srb;

    changerData->Size = sizeof(CHANGER_DATA);

    //
    // Build address mapping.
    //

    status = AdicBuildAddressMapping(DeviceObject);
    if (!NT_SUCCESS(status)) {
        DebugPrint((1,
                    "BuildAddressMapping failed. %x\n", status));

        //
        // Indicate that the device needs to re-init.
        //

        changerData->AddressMapping.Initialized = FALSE;
    }

    //
    // Get inquiry data.
    //

    dataBuffer = ChangerClassAllocatePool(NonPagedPoolCacheAligned, sizeof(INQUIRYDATA));
    if (!dataBuffer) {
        DebugPrint((1,
                    "Adicsc.ChangerInitialize: Error allocating dataBuffer. %x\n", status));
        return STATUS_INSUFFICIENT_RESOURCES;
    }

    //
    // Now get the full inquiry information for the device.
    //

    RtlZeroMemory(&srb, SCSI_REQUEST_BLOCK_SIZE);

    //
    // Set timeout value.
    //

    srb.TimeOutValue = 10;

    srb.CdbLength = 6;

    cdb = (PCDB)srb.Cdb;

    //
    // Set CDB operation code.
    //

    cdb->CDB6INQUIRY.OperationCode = SCSIOP_INQUIRY;

    //
    // Set allocation length to inquiry data buffer size.
    //

    cdb->CDB6INQUIRY.AllocationLength = sizeof(INQUIRYDATA);

    status = ClassSendSrbSynchronous(DeviceObject,
                                         &srb,
                                         dataBuffer,
                                         sizeof(INQUIRYDATA),
                                         FALSE);

    if (SRB_STATUS(srb.SrbStatus) == SRB_STATUS_SUCCESS ||
        SRB_STATUS(srb.SrbStatus) == SRB_STATUS_DATA_OVERRUN) {

        //
        // Updated the length actually transfered.
        //

        length = dataBuffer->AdditionalLength + FIELD_OFFSET(INQUIRYDATA, Reserved);

        if (length > srb.DataTransferLength) {
            length = srb.DataTransferLength;
        }


        RtlMoveMemory(&changerData->InquiryData, dataBuffer, length);

        //
        // Determine drive id.
        //

        if (RtlCompareMemory(dataBuffer->ProductId,"Scalar DLT", 10) == 10) {
            changerData->DriveID = ADIC_SCALAR;
        }
        if (RtlCompareMemory(dataBuffer->ProductId,"FastStor DLT", 12) == 12) {
            changerData->DriveID = ADIC_SCALAR;
        }
    }

    ChangerClassFreePool(dataBuffer);

    return STATUS_SUCCESS;
}


BOOLEAN
ChangerVerifyInquiry(
    PINQUIRYDATA InquiryData
    )
/*++

Routine Description:

    This routine determines whether the device specified in InquiryData
    should be supported by this module.

Arguments:

    InquiryData - Pointer to inquiry data.

Return Value:

    TRUE - If this is a supported device.

--*/

{

    if (RtlCompareMemory(InquiryData->ProductId,"Scalar DLT",10) == 10) {

        return TRUE;
    }

    if (RtlCompareMemory(InquiryData->ProductId,"FastStor DLT", 12) == 12) {
        return TRUE;
    }
    
    return FALSE;
}


VOID
ChangerError(
    PDEVICE_OBJECT DeviceObject,
    PSCSI_REQUEST_BLOCK Srb,
    NTSTATUS *Status,
    BOOLEAN *Retry
    )

/*++

Routine Description:

    This routine executes any device-specific error handling needed.

Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/
{

    PSENSE_DATA senseBuffer = Srb->SenseInfoBuffer;
    PIRP irp = Srb->OriginalRequest;

    if (Srb->SrbStatus & SRB_STATUS_AUTOSENSE_VALID) {

        switch (senseBuffer->SenseKey & 0xf) {

        case SCSI_SENSE_NOT_READY:

            if (senseBuffer->AdditionalSenseCode == 0x04) {
                switch (senseBuffer->AdditionalSenseCodeQualifier) {
                    case 0x82:

                        *Retry = FALSE;
                        *Status = STATUS_DEVICE_DOOR_OPEN;
                        break;
                }
            }

            break;

        case SCSI_SENSE_ILLEGAL_REQUEST:
            break;

        case SCSI_SENSE_HARDWARE_ERROR:

            //
            // The ADIC returns 4/40/01 for some illegal commands.
            //

            if (senseBuffer->AdditionalSenseCode == 0x40) {
                if (senseBuffer->AdditionalSenseCodeQualifier == 0x01) {
                    *Retry = FALSE;
                    *Status = STATUS_INVALID_DEVICE_REQUEST;
                }
            }
            break;

        default:
            break;
        }
    }


    return;
}

NTSTATUS
ChangerGetParameters(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    This routine determines and returns the "drive parameters" of the
    ADIC Scalar changers.

Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/

{
    PFUNCTIONAL_DEVICE_EXTENSION          fdoExtension = DeviceObject->DeviceExtension;
    PCHANGER_DATA              changerData = (PCHANGER_DATA)(fdoExtension->CommonExtension.DriverData);
    PCHANGER_ADDRESS_MAPPING   addressMapping = &(changerData->AddressMapping);
    PSCSI_REQUEST_BLOCK        srb;
    PGET_CHANGER_PARAMETERS    changerParameters;
    PMODE_ELEMENT_ADDRESS_PAGE elementAddressPage;
    PMODE_TRANSPORT_GEOMETRY_PAGE transportGeometryPage;
    PMODE_DEVICE_CAPABILITIES_PAGE capabilitiesPage;
    NTSTATUS status;
    ULONG    length;
    PVOID    modeBuffer;
    PCDB     cdb;

    srb = ChangerClassAllocatePool(NonPagedPool, SCSI_REQUEST_BLOCK_SIZE);

    if (srb == NULL) {

        return STATUS_INSUFFICIENT_RESOURCES;
    }

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;

    //
    // Build a mode sense - Element address assignment page.
    //

    modeBuffer = ChangerClassAllocatePool(NonPagedPoolCacheAligned, sizeof(MODE_PARAMETER_HEADER)
                                + sizeof(MODE_ELEMENT_ADDRESS_PAGE));
    if (!modeBuffer) {
        ChangerClassFreePool(srb);
        return STATUS_INSUFFICIENT_RESOURCES;
    }


    RtlZeroMemory(modeBuffer, sizeof(MODE_PARAMETER_HEADER) + sizeof(MODE_ELEMENT_ADDRESS_PAGE));
    srb->CdbLength = CDB6GENERIC_LENGTH;
    srb->TimeOutValue = 20;
    srb->DataTransferLength = sizeof(MODE_PARAMETER_HEADER) + sizeof(MODE_ELEMENT_ADDRESS_PAGE);
    srb->DataBuffer = modeBuffer;

    cdb->MODE_SENSE.OperationCode = SCSIOP_MODE_SENSE;
    cdb->MODE_SENSE.PageCode = MODE_PAGE_ELEMENT_ADDRESS;
    cdb->MODE_SENSE.Dbd = 1;
    cdb->MODE_SENSE.AllocationLength = (UCHAR)srb->DataTransferLength;

    //
    // Send the request.
    //

    status = ClassSendSrbSynchronous(DeviceObject,
                                         srb,
                                         srb->DataBuffer,
                                         srb->DataTransferLength,
                                         FALSE);

    if (!NT_SUCCESS(status)) {
        ChangerClassFreePool(srb);
        ChangerClassFreePool(modeBuffer);
        return status;
    }

    //
    // Fill in values.
    //

    changerParameters = Irp->AssociatedIrp.SystemBuffer;
    RtlZeroMemory(changerParameters, sizeof(GET_CHANGER_PARAMETERS));

    elementAddressPage = modeBuffer;
    (PCHAR)elementAddressPage += sizeof(MODE_PARAMETER_HEADER);

    changerParameters->Size = sizeof(GET_CHANGER_PARAMETERS);
    changerParameters->NumberTransportElements = elementAddressPage->NumberTransportElements[1];
    changerParameters->NumberTransportElements |= (elementAddressPage->NumberTransportElements[0] << 8);

    changerParameters->NumberStorageElements = elementAddressPage->NumberStorageElements[1];
    changerParameters->NumberStorageElements |= (elementAddressPage->NumberStorageElements[0] << 8);

    changerParameters->NumberIEElements = elementAddressPage->NumberIEPortElements[1];
    changerParameters->NumberIEElements |= (elementAddressPage->NumberIEPortElements[0] << 8);

    changerParameters->NumberDataTransferElements = elementAddressPage->NumberDataXFerElements[1];
    changerParameters->NumberDataTransferElements |= (elementAddressPage->NumberDataXFerElements[0] << 8);
    changerParameters->NumberOfDoors = 1;
    changerParameters->NumberCleanerSlots = 1;

    changerParameters->FirstSlotNumber = 0;
    changerParameters->FirstDriveNumber =  0;
    changerParameters->FirstTransportNumber = 0;
    changerParameters->FirstIEPortNumber = 0;
    changerParameters->FirstCleanerSlotAddress = 0;

    changerParameters->MagazineSize = 0;
    changerParameters->DriveCleanTimeout = 300;

    if (!addressMapping->Initialized) {
        ULONG i;

        //
        // Build address mapping.
        //

        addressMapping->FirstElement[ChangerTransport] = (elementAddressPage->MediumTransportElementAddress[0] << 8) |
                                                          elementAddressPage->MediumTransportElementAddress[1];
        addressMapping->FirstElement[ChangerDrive] = (elementAddressPage->FirstDataXFerElementAddress[0] << 8) |
                                                      elementAddressPage->FirstDataXFerElementAddress[1];
        addressMapping->FirstElement[ChangerIEPort] = (elementAddressPage->FirstIEPortElementAddress[0] << 8) |
                                                       elementAddressPage->FirstIEPortElementAddress[1];
        addressMapping->FirstElement[ChangerSlot] = (elementAddressPage->FirstStorageElementAddress[0] << 8) |
                                                     elementAddressPage->FirstStorageElementAddress[1];
        addressMapping->FirstElement[ChangerDoor] = 0;

        addressMapping->FirstElement[ChangerKeypad] = 0;

        addressMapping->NumberOfElements[ChangerTransport] = elementAddressPage->NumberTransportElements[1];
        addressMapping->NumberOfElements[ChangerTransport] |= (elementAddressPage->NumberTransportElements[0] << 8);

        addressMapping->NumberOfElements[ChangerDrive] = elementAddressPage->NumberDataXFerElements[1];
        addressMapping->NumberOfElements[ChangerDrive] |= (elementAddressPage->NumberDataXFerElements[0] << 8);

        addressMapping->NumberOfElements[ChangerIEPort] = elementAddressPage->NumberIEPortElements[1];
        addressMapping->NumberOfElements[ChangerIEPort] |= (elementAddressPage->NumberIEPortElements[0] << 8);

        addressMapping->NumberOfElements[ChangerSlot] = elementAddressPage->NumberStorageElements[1];
        addressMapping->NumberOfElements[ChangerSlot] |= (elementAddressPage->NumberStorageElements[0] << 8);

        addressMapping->NumberOfElements[ChangerDoor] = 1;
        addressMapping->NumberOfElements[ChangerKeypad] = 1;

        addressMapping->Initialized = TRUE;

        //
        // Determine the lowest element address for use with AllElements.
        //

        for (i = 0; i < ChangerDrive; i++) {
            if (addressMapping->FirstElement[i] < addressMapping->FirstElement[AllElements]) {
                addressMapping->FirstElement[AllElements] = addressMapping->FirstElement[i];
            }
        }
    }

    //
    // Free buffer.
    //

    ChangerClassFreePool(modeBuffer);

    //
    // build transport geometry mode sense.
    //

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;

    modeBuffer = ChangerClassAllocatePool(NonPagedPoolCacheAligned, sizeof(MODE_PARAMETER_HEADER)
                                + sizeof(MODE_TRANSPORT_GEOMETRY_PAGE));
    if (!modeBuffer) {
        ChangerClassFreePool(srb);
        return STATUS_INSUFFICIENT_RESOURCES;
    }


    RtlZeroMemory(modeBuffer, sizeof(MODE_PARAMETER_HEADER) + sizeof(MODE_TRANSPORT_GEOMETRY_PAGE));
    srb->CdbLength = CDB6GENERIC_LENGTH;
    srb->TimeOutValue = 20;
    srb->DataTransferLength = sizeof(MODE_PARAMETER_HEADER) + sizeof(MODE_TRANSPORT_GEOMETRY_PAGE);
    srb->DataBuffer = modeBuffer;

    cdb->MODE_SENSE.OperationCode = SCSIOP_MODE_SENSE;
    cdb->MODE_SENSE.PageCode = MODE_PAGE_TRANSPORT_GEOMETRY;
    cdb->MODE_SENSE.Dbd = 1;
    cdb->MODE_SENSE.AllocationLength = (UCHAR)srb->DataTransferLength;

    //
    // Send the request.
    //

    status = ClassSendSrbSynchronous(DeviceObject,
                                         srb,
                                         srb->DataBuffer,
                                         srb->DataTransferLength,
                                         FALSE);

    if (!NT_SUCCESS(status)) {
        ChangerClassFreePool(srb);
        ChangerClassFreePool(modeBuffer);
        return status;
    }

    changerParameters = Irp->AssociatedIrp.SystemBuffer;
    transportGeometryPage = modeBuffer;
    (PCHAR)transportGeometryPage += sizeof(MODE_PARAMETER_HEADER);

    //
    // Determine if mc has 2-sided media.
    //
    changerParameters->Features0 = transportGeometryPage->Flip ? CHANGER_MEDIUM_FLIP : 0;

    //
    // Set IEPort flags if the changer has at least one IEPort
    //
    if (changerParameters->NumberIEElements != 0) {
       changerParameters->Features1 = CHANGER_IEPORT_USER_CONTROL_OPEN |
                                      CHANGER_IEPORT_USER_CONTROL_CLOSE;
    } 

    //
    // The ADICs indicates whether a bar-code scanner is
    // attached by setting bit-0 in this byte.
    //

    changerParameters->Features0 |= ((changerData->InquiryData.VendorSpecific[19] & 0x1)) ?
                                         CHANGER_BAR_CODE_SCANNER_INSTALLED : 0;
    //
    // Features based on manual, nothing programatic.
    //

    changerParameters->Features0 |= CHANGER_INIT_ELEM_STAT_WITH_RANGE     |
                                    CHANGER_POSITION_TO_ELEMENT           |
                                    CHANGER_PREDISMOUNT_EJECT_REQUIRED    |
                                    CHANGER_DRIVE_CLEANING_REQUIRED       |
                                    CHANGER_DRIVE_EMPTY_ON_DOOR_ACCESS    |
                                    CHANGER_CLEANER_ACCESS_NOT_VALID;

    if (changerParameters->NumberIEElements == 0) {

        //
        // No real IE Elements - nothing can be programatically locked.
        //

        changerParameters->PositionCapabilities = (CHANGER_TO_SLOT | CHANGER_TO_DRIVE);

    } else {
        changerParameters->PositionCapabilities = (CHANGER_TO_SLOT | CHANGER_TO_DRIVE | CHANGER_TO_IEPORT);
    }

    changerParameters->LockUnlockCapabilities = 0;

    changerParameters->NumberCleanerSlots = 0;
    changerParameters->FirstSlotNumber = 1;

    if (changerParameters->Features0 & CHANGER_BAR_CODE_SCANNER_INSTALLED) {

        if (changerParameters->NumberStorageElements == 17) {

            //
            // This is the 218.
            // Barcode scanner steals the lowest slot.
            //

            changerParameters->FirstSlotNumber = 2;

        }
    }

    //
    // Free buffer.
    //

    ChangerClassFreePool(modeBuffer);

    //
    // build transport geometry mode sense.
    //


    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;

    length =  sizeof(MODE_PARAMETER_HEADER) + sizeof(MODE_DEVICE_CAPABILITIES_PAGE);
    modeBuffer = ChangerClassAllocatePool(NonPagedPoolCacheAligned, length);

    if (!modeBuffer) {
        ChangerClassFreePool(srb);
        return STATUS_INSUFFICIENT_RESOURCES;
    }

    RtlZeroMemory(modeBuffer, length);
    srb->CdbLength = CDB6GENERIC_LENGTH;
    srb->TimeOutValue = 20;
    srb->DataTransferLength = length;
    srb->DataBuffer = modeBuffer;

    cdb->MODE_SENSE.OperationCode = SCSIOP_MODE_SENSE;
    cdb->MODE_SENSE.PageCode = MODE_PAGE_DEVICE_CAPABILITIES;
    cdb->MODE_SENSE.Dbd = 1;
    cdb->MODE_SENSE.AllocationLength = (UCHAR)srb->DataTransferLength;

    //
    // Send the request.
    //

    status = ClassSendSrbSynchronous(DeviceObject,
                                         srb,
                                         srb->DataBuffer,
                                         srb->DataTransferLength,
                                         FALSE);

    if (!NT_SUCCESS(status)) {
        ChangerClassFreePool(srb);
        ChangerClassFreePool(modeBuffer);
        return status;
    }

    //
    // Get the systembuffer and by-pass the mode header for the mode sense data.
    //

    changerParameters = Irp->AssociatedIrp.SystemBuffer;
    capabilitiesPage = modeBuffer;
    (PCHAR)capabilitiesPage += sizeof(MODE_PARAMETER_HEADER);

    //
    // Fill in values in Features that are contained in this page.
    //

    changerParameters->Features0 |= capabilitiesPage->MediumTransport ? CHANGER_STORAGE_DRIVE : 0;
    changerParameters->Features0 |= capabilitiesPage->StorageLocation ? CHANGER_STORAGE_SLOT : 0;
    changerParameters->Features0 |= capabilitiesPage->IEPort ? CHANGER_STORAGE_IEPORT : 0;
    changerParameters->Features0 |= capabilitiesPage->DataXFer ? CHANGER_STORAGE_DRIVE : 0;

    //
    // Fix up the 218's storage capabilities.
    //

    if (changerParameters->NumberIEElements == 0) {
        changerParameters->Features0 &= ~CHANGER_STORAGE_IEPORT;
    }

    //
    // Determine all the move from and exchange from capabilities of this device.
    //

    changerParameters->MoveFromTransport = capabilitiesPage->MTtoMT ? CHANGER_TO_TRANSPORT : 0;
    changerParameters->MoveFromTransport |= capabilitiesPage->MTtoST ? CHANGER_TO_SLOT : 0;
    changerParameters->MoveFromTransport |= capabilitiesPage->MTtoIE ? CHANGER_TO_IEPORT : 0;
    changerParameters->MoveFromTransport |= capabilitiesPage->MTtoDT ? CHANGER_TO_DRIVE : 0;

    changerParameters->MoveFromSlot = capabilitiesPage->STtoMT ? CHANGER_TO_TRANSPORT : 0;
    changerParameters->MoveFromSlot |= capabilitiesPage->STtoST ? CHANGER_TO_SLOT : 0;
    changerParameters->MoveFromSlot |= capabilitiesPage->STtoIE ? CHANGER_TO_IEPORT : 0;
    changerParameters->MoveFromSlot |= capabilitiesPage->STtoDT ? CHANGER_TO_DRIVE : 0;

    changerParameters->MoveFromIePort = capabilitiesPage->IEtoMT ? CHANGER_TO_TRANSPORT : 0;
    changerParameters->MoveFromIePort |= capabilitiesPage->IEtoST ? CHANGER_TO_SLOT : 0;
    changerParameters->MoveFromIePort |= capabilitiesPage->IEtoIE ? CHANGER_TO_IEPORT : 0;
    changerParameters->MoveFromIePort |= capabilitiesPage->IEtoDT ? CHANGER_TO_DRIVE : 0;

    changerParameters->MoveFromDrive = capabilitiesPage->DTtoMT ? CHANGER_TO_TRANSPORT : 0;
    changerParameters->MoveFromDrive |= capabilitiesPage->DTtoST ? CHANGER_TO_SLOT : 0;
    changerParameters->MoveFromDrive |= capabilitiesPage->DTtoIE ? CHANGER_TO_IEPORT : 0;
    changerParameters->MoveFromDrive |= capabilitiesPage->DTtoDT ? CHANGER_TO_DRIVE : 0;

    changerParameters->ExchangeFromTransport = capabilitiesPage->XMTtoMT ? CHANGER_TO_TRANSPORT : 0;
    changerParameters->ExchangeFromTransport |= capabilitiesPage->XMTtoST ? CHANGER_TO_SLOT : 0;
    changerParameters->ExchangeFromTransport |= capabilitiesPage->XMTtoIE ? CHANGER_TO_IEPORT : 0;
    changerParameters->ExchangeFromTransport |= capabilitiesPage->XMTtoDT ? CHANGER_TO_DRIVE : 0;

    changerParameters->ExchangeFromSlot = capabilitiesPage->XSTtoMT ? CHANGER_TO_TRANSPORT : 0;
    changerParameters->ExchangeFromSlot |= capabilitiesPage->XSTtoST ? CHANGER_TO_SLOT : 0;
    changerParameters->ExchangeFromSlot |= capabilitiesPage->XSTtoIE ? CHANGER_TO_IEPORT : 0;
    changerParameters->ExchangeFromSlot |= capabilitiesPage->XSTtoDT ? CHANGER_TO_DRIVE : 0;

    changerParameters->ExchangeFromIePort = capabilitiesPage->XIEtoMT ? CHANGER_TO_TRANSPORT : 0;
    changerParameters->ExchangeFromIePort |= capabilitiesPage->XIEtoST ? CHANGER_TO_SLOT : 0;
    changerParameters->ExchangeFromIePort |= capabilitiesPage->XIEtoIE ? CHANGER_TO_IEPORT : 0;
    changerParameters->ExchangeFromIePort |= capabilitiesPage->XIEtoDT ? CHANGER_TO_DRIVE : 0;

    changerParameters->ExchangeFromDrive = capabilitiesPage->XDTtoMT ? CHANGER_TO_TRANSPORT : 0;
    changerParameters->ExchangeFromDrive |= capabilitiesPage->XDTtoST ? CHANGER_TO_SLOT : 0;
    changerParameters->ExchangeFromDrive |= capabilitiesPage->XDTtoIE ? CHANGER_TO_IEPORT : 0;
    changerParameters->ExchangeFromDrive |= capabilitiesPage->XDTtoDT ? CHANGER_TO_DRIVE : 0;


    ChangerClassFreePool(srb);
    ChangerClassFreePool(modeBuffer);

    Irp->IoStatus.Information = sizeof(GET_CHANGER_PARAMETERS);

    return STATUS_SUCCESS;
}


NTSTATUS
ChangerGetStatus(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    This routine returns the status of the medium changer as determined through a TUR.

Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/

{
    PFUNCTIONAL_DEVICE_EXTENSION   fdoExtension = DeviceObject->DeviceExtension;
    PSCSI_REQUEST_BLOCK srb;
    PCDB     cdb;
    NTSTATUS status;

    srb = ChangerClassAllocatePool(NonPagedPool, SCSI_REQUEST_BLOCK_SIZE);

    if (!srb) {

        return STATUS_INSUFFICIENT_RESOURCES;
    }

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;

    //
    // Build TUR.
    //

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;

    srb->CdbLength = CDB6GENERIC_LENGTH;
    cdb->CDB6GENERIC.OperationCode = SCSIOP_TEST_UNIT_READY;
    srb->TimeOutValue = 20;

    //
    // Send SCSI command (CDB) to device
    //

    status = ClassSendSrbSynchronous(DeviceObject,
                                         srb,
                                         NULL,
                                         0,
                                         FALSE);

    ChangerClassFreePool(srb);
    return status;
}


NTSTATUS
ChangerGetProductData(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    This routine returns fields from the inquiry data useful for
    identifying the particular device.

Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/

{

    PFUNCTIONAL_DEVICE_EXTENSION fdoExtension = DeviceObject->DeviceExtension;
    PCHANGER_DATA changerData = (PCHANGER_DATA)(fdoExtension->CommonExtension.DriverData);
    PCHANGER_PRODUCT_DATA productData = Irp->AssociatedIrp.SystemBuffer;

    RtlZeroMemory(productData, sizeof(CHANGER_PRODUCT_DATA));

    //
    // Copy cached inquiry data fields into the system buffer.
    //

    RtlMoveMemory(productData->VendorId, changerData->InquiryData.VendorId, VENDOR_ID_LENGTH);
    RtlMoveMemory(productData->ProductId, changerData->InquiryData.ProductId, PRODUCT_ID_LENGTH);
    RtlMoveMemory(productData->Revision, changerData->InquiryData.ProductRevisionLevel, REVISION_LENGTH);
    RtlMoveMemory(productData->SerialNumber, changerData->InquiryData.VendorSpecific, SERIAL_NUMBER_LENGTH);

    //
    // Indicate that this is a tape changer and that media isn't two-sided.
    //

    productData->DeviceType = MEDIUM_CHANGER;

    Irp->IoStatus.Information = sizeof(CHANGER_PRODUCT_DATA);
    return STATUS_SUCCESS;
}



NTSTATUS
ChangerSetAccess(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    This routine sets the state of the door or IEPort. Value can be one of the
    following:


Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/

{

   // doors cannot be locked, 
   // ieport has no extend/retract feature on 448 unit
   // ieport solenoid burns out if left activated constandly, 
   //   so ieport locking is only done around MoveMedium calls that
   //   involve the IEPORT. 
   // therefore all calls to this function are invalid. 

   return STATUS_INVALID_DEVICE_REQUEST;
}


NTSTATUS
ChangerGetElementStatus(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    This routine builds and issues a read element status command for either all elements or the
    specified element type. The buffer returned is used to build the user buffer.

Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/

{

    PFUNCTIONAL_DEVICE_EXTENSION fdoExtension = DeviceObject->DeviceExtension;
    PCHANGER_DATA     changerData = (PCHANGER_DATA)(fdoExtension->CommonExtension.DriverData);
    PCHANGER_ADDRESS_MAPPING     addressMapping = &(changerData->AddressMapping);
    PCHANGER_READ_ELEMENT_STATUS readElementStatus = Irp->AssociatedIrp.SystemBuffer;
    PCHANGER_ELEMENT_STATUS      elementStatus;
    PCHANGER_ELEMENT    element;
    ELEMENT_TYPE        elementType;
    PSCSI_REQUEST_BLOCK srb;
    PCDB     cdb;
    ULONG    length;
    ULONG    statusPages;
    NTSTATUS status;
    PVOID    statusBuffer;

    //
    // Determine the element type.
    //

    elementType = readElementStatus->ElementList.Element.ElementType;
    element = &readElementStatus->ElementList.Element;

    //
    // length will be based on whether vol. tags are returned and element type(s).
    //

    if (elementType == AllElements) {

        //
        // There should be 4 status pages in the returned buffer.
        //

        statusPages = 4;
    } else {

        if (ElementOutOfRange(addressMapping, (USHORT)element->ElementAddress, elementType)) {
            DebugPrint((1,
                       "ChangerGetElementStatus: Element out of range.\n"));

            return STATUS_ILLEGAL_ELEMENT_ADDRESS;
        }


        statusPages = 1;
    }

    //
    // Account for length of all status pages and the header.
    //

    length = sizeof(ELEMENT_STATUS_HEADER) + (statusPages * sizeof(ELEMENT_STATUS_PAGE));

    if (readElementStatus->VolumeTagInfo) {

        //
        // Each descriptor will have an embedded volume tag buffer.
        //

        length += sizeof(ADICS_ELEMENT_DESCRIPTOR_PLUS) *  readElementStatus->ElementList.NumberOfElements;

    } else {

        length += sizeof(ADICS_ELEMENT_DESCRIPTOR) * readElementStatus->ElementList.NumberOfElements;
    }


    statusBuffer = ChangerClassAllocatePool(NonPagedPoolCacheAligned, length);

    if (!statusBuffer) {
        return STATUS_INSUFFICIENT_RESOURCES;
    }

    RtlZeroMemory(statusBuffer, length);

    //
    // Build srb and cdb.
    //

    srb = ChangerClassAllocatePool(NonPagedPool, SCSI_REQUEST_BLOCK_SIZE);

    if (!srb) {
        ChangerClassFreePool(statusBuffer);
        return STATUS_INSUFFICIENT_RESOURCES;
    }

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;

    srb->CdbLength = CDB12GENERIC_LENGTH;
    srb->DataBuffer = statusBuffer;
    srb->DataTransferLength = length;
    srb->TimeOutValue = 200;

    cdb->READ_ELEMENT_STATUS.OperationCode = SCSIOP_READ_ELEMENT_STATUS;

    cdb->READ_ELEMENT_STATUS.ElementType = (UCHAR)elementType;
    cdb->READ_ELEMENT_STATUS.VolTag = readElementStatus->VolumeTagInfo;

    //
    // Fill in element addressing info based on the mapping values.
    //

    cdb->READ_ELEMENT_STATUS.StartingElementAddress[0] =
        (UCHAR)((element->ElementAddress + addressMapping->FirstElement[element->ElementType]) >> 8);

    cdb->READ_ELEMENT_STATUS.StartingElementAddress[1] =
        (UCHAR)((element->ElementAddress + addressMapping->FirstElement[element->ElementType]) & 0xFF);

    cdb->READ_ELEMENT_STATUS.NumberOfElements[0] = (UCHAR)(readElementStatus->ElementList.NumberOfElements >> 8);
    cdb->READ_ELEMENT_STATUS.NumberOfElements[1] = (UCHAR)(readElementStatus->ElementList.NumberOfElements & 0xFF);

    cdb->READ_ELEMENT_STATUS.AllocationLength[0] = (UCHAR)(length >> 16);
    cdb->READ_ELEMENT_STATUS.AllocationLength[1] = (UCHAR)(length >> 8);
    cdb->READ_ELEMENT_STATUS.AllocationLength[2] = (UCHAR)(length & 0xFF);

    //
    // Send SCSI command (CDB) to device
    //

    status = ClassSendSrbSynchronous(DeviceObject,
                                         srb,
                                         srb->DataBuffer,
                                         srb->DataTransferLength,
                                         FALSE);

    if (NT_SUCCESS(status) || (status == STATUS_DATA_OVERRUN)) {

        PELEMENT_STATUS_HEADER statusHeader = statusBuffer;
        PELEMENT_STATUS_PAGE statusPage;
        PADICS_ELEMENT_DESCRIPTOR elementDescriptor;
        ULONG numberElements = readElementStatus->ElementList.NumberOfElements;
        ULONG remainingElements;
        ULONG typeCount;
        BOOLEAN tagInfo = readElementStatus->VolumeTagInfo;
        ULONG i;
        ULONG descriptorLength;


        //
        // Check if the error was STATUS_DATA_OVERRUN
        //
        if (status == STATUS_DATA_OVERRUN) {
           //
           // Check if there was a DATA_OVERRUN, or was it just 
           // DATA_UNDERRUN reported as DATA_OVERRRUN.
           //
           if (srb->DataTransferLength < length) {
              DebugPrint((1, 
                          "DATA_UNDERRUN reported as DATA_OVERRUN."));
              DebugPrint((1,
                          "Expected: %d, Transferred: %d.\n",
                          length, srb->DataTransferLength));
              status = STATUS_SUCCESS;
           } else {
              //
              // It was really DATA_OVERRUN error. Report accordingly.
              //
              ChangerClassFreePool(srb);
              ChangerClassFreePool(statusBuffer);
          
              return status;
           }
        }

        //
        // Determine total number elements returned.
        //

        remainingElements = statusHeader->NumberOfElements[1];
        remainingElements |= (statusHeader->NumberOfElements[0] << 8);

        //
        // The buffer is composed of a header, status page, and element descriptors.
        // Point each element to it's respective place in the buffer.
        //

        (PCHAR)statusPage = (PCHAR)statusHeader;
        (PCHAR)statusPage += sizeof(ELEMENT_STATUS_HEADER);

        elementType = statusPage->ElementType;

        (PCHAR)elementDescriptor = (PCHAR)statusPage;
        (PCHAR)elementDescriptor += sizeof(ELEMENT_STATUS_PAGE);

        descriptorLength = statusPage->ElementDescriptorLength[1];
        descriptorLength |= (statusPage->ElementDescriptorLength[0] << 8);

        //
        // Determine the number of elements of this type reported.
        //

        typeCount =  statusPage->DescriptorByteCount[2];
        typeCount |=  (statusPage->DescriptorByteCount[1] << 8);
        typeCount |=  (statusPage->DescriptorByteCount[0] << 16);

        typeCount /= descriptorLength;

        //
        // Fill in user buffer.
        //

        elementStatus = Irp->AssociatedIrp.SystemBuffer;

        do {

            for (i = 0; i < typeCount; i++, remainingElements--) {

                //
                // Get the address for this element.
                //

                elementStatus->Element.ElementAddress =
                    elementDescriptor->ElementAddress[1];
                elementStatus->Element.ElementAddress |=
                    (elementDescriptor->ElementAddress[0] << 8);

                //
                // Account for address mapping.
                //

                elementStatus->Element.ElementAddress -= addressMapping->FirstElement[elementType];

                //
                // Set the element type.
                //

                elementStatus->Element.ElementType = elementType;


                if (elementDescriptor->SValid) {

                    ULONG  j;
                    USHORT tmpAddress;


                    //
                    // Source address is valid. Determine the device specific address.
                    //

                    tmpAddress = elementDescriptor->SourceStorageElementAddress[1];
                    tmpAddress |= (elementDescriptor->SourceStorageElementAddress[0] << 8);

                    //
                    // Now convert to 0-based values.
                    //

                    for (j = 1; j <= ChangerDrive; j++) {
                        if (addressMapping->FirstElement[j] <= tmpAddress) {
                            if (tmpAddress < (addressMapping->NumberOfElements[j] + addressMapping->FirstElement[j])) {
                                elementStatus->SrcElementAddress.ElementType = j;
                                break;
                            }
                        }
                    }

                    elementStatus->SrcElementAddress.ElementAddress = tmpAddress - addressMapping->FirstElement[j];

                }

                //
                // Build Flags field.
                //

                elementStatus->Flags = elementDescriptor->Full;
                elementStatus->Flags |= (elementDescriptor->Exception << 2);
                elementStatus->Flags |= (elementDescriptor->Accessible << 3);

                elementStatus->Flags |= (elementDescriptor->LunValid << 12);
                elementStatus->Flags |= (elementDescriptor->IdValid << 13);
                elementStatus->Flags |= (elementDescriptor->NotThisBus << 15);

                elementStatus->Flags |= (elementDescriptor->Invert << 22);
                elementStatus->Flags |= (elementDescriptor->SValid << 23);


                if (elementStatus->Flags & ELEMENT_STATUS_EXCEPT) {
                    elementStatus->ExceptionCode = MapExceptionCodes(elementDescriptor);
                }

                if (elementDescriptor->IdValid) {
                    elementStatus->TargetId = elementDescriptor->BusAddress;
                }
                if (elementDescriptor->LunValid) {
                    elementStatus->Lun = elementDescriptor->Lun;
                }

                //
                // Ensure that media is actually present. If so, get the tag info.
                //

                if (elementDescriptor->Full) {
                    if (tagInfo) {
                        if (statusPage->PVolTag) {
                            ULONG tagIndex;

                            //
                            // Verify validity of volume tag information.
                            //

                            for (tagIndex = 0; tagIndex < 14; tagIndex++) {
                                if (((PADICS_ELEMENT_DESCRIPTOR_PLUS)elementDescriptor)->VolumeTagInformation[tagIndex] != 0) {
                                    break;
                                }
                            }
                            if (tagIndex == 14) {

                                elementStatus->ExceptionCode = ERROR_LABEL_UNREADABLE;
                                elementStatus->Flags |= ELEMENT_STATUS_EXCEPT;

                            } else {
                                RtlMoveMemory(elementStatus->PrimaryVolumeID,
                                              ((PADICS_ELEMENT_DESCRIPTOR_PLUS)elementDescriptor)->VolumeTagInformation,
                                              MAX_VOLUME_ID_SIZE);

                                elementStatus->Flags |= ELEMENT_STATUS_PVOLTAG;
                            }

                        } else {
                            DebugPrint((1,
                                       "ChangerGetElementStatus: tagInfo requested but PVoltag not set\n"));
                        }
                    }
                }

                //
                // Get next descriptor.
                //

                (PCHAR)elementDescriptor += descriptorLength;

                //
                // Advance to the next entry in the user buffer and element descriptor array.
                //

                elementStatus += 1;

            }

            if (remainingElements) {

                //
                // Get next status page.
                //

                (PCHAR)statusPage = (PCHAR)elementDescriptor;

                elementType = statusPage->ElementType;

                //
                // Point to decriptors.
                //

                (PCHAR)elementDescriptor = (PCHAR)statusPage;
                (PCHAR)elementDescriptor += sizeof(ELEMENT_STATUS_PAGE);

                descriptorLength = statusPage->ElementDescriptorLength[1];
                descriptorLength |= (statusPage->ElementDescriptorLength[0] << 8);

                //
                // Determine the number of this element type reported.
                //

                typeCount =  statusPage->DescriptorByteCount[2];
                typeCount |=  (statusPage->DescriptorByteCount[1] << 8);
                typeCount |=  (statusPage->DescriptorByteCount[0] << 16);

                typeCount /= descriptorLength;
            }

        } while (remainingElements);

        Irp->IoStatus.Information = sizeof(CHANGER_ELEMENT_STATUS) * numberElements;

    }

    ChangerClassFreePool(srb);
    ChangerClassFreePool(statusBuffer);

    return status;
}


NTSTATUS
ChangerInitializeElementStatus(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    This routine issues the necessary command to either initialize all elements
    or the specified range of elements using the normal SCSI-2 command, or a vendor-unique
    range command.

Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/

{

    PFUNCTIONAL_DEVICE_EXTENSION   fdoExtension = DeviceObject->DeviceExtension;
    PCHANGER_DATA       changerData = (PCHANGER_DATA)(fdoExtension->CommonExtension.DriverData);
    PCHANGER_ADDRESS_MAPPING addressMapping = &(changerData->AddressMapping);
    PCHANGER_INITIALIZE_ELEMENT_STATUS initElementStatus = Irp->AssociatedIrp.SystemBuffer;
    PSCSI_REQUEST_BLOCK srb;
    PCDB                cdb;
    NTSTATUS            status;

    //
    // Build srb and cdb.
    //

    srb = ChangerClassAllocatePool(NonPagedPool, SCSI_REQUEST_BLOCK_SIZE);

    if (!srb) {

        return STATUS_INSUFFICIENT_RESOURCES;
    }

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;

    if (initElementStatus->ElementList.Element.ElementType == AllElements) {

        //
        // Build the normal SCSI-2 command for all elements.
        //

        srb->CdbLength = CDB6GENERIC_LENGTH;
        cdb->INIT_ELEMENT_STATUS.OperationCode = SCSIOP_INIT_ELEMENT_STATUS;
        cdb->INIT_ELEMENT_STATUS.NoBarCode = initElementStatus->BarCodeScan ? 0 : 1;

        srb->TimeOutValue = fdoExtension->TimeOutValue;
        srb->DataTransferLength = 0;

    } else {

        PCHANGER_ELEMENT_LIST elementList = &initElementStatus->ElementList;
        PCHANGER_ELEMENT element = &elementList->Element;

        //
        // Use the ADIC vendor-unique initialize with range command
        //

        srb->CdbLength = CDB10GENERIC_LENGTH;
        cdb->INITIALIZE_ELEMENT_RANGE.OperationCode = SCSIOP_INIT_ELEMENT_RANGE;
        cdb->INITIALIZE_ELEMENT_RANGE.Range = 1;

        //
        // Addresses of elements need to be mapped from 0-based to device-specific.
        //

        cdb->INITIALIZE_ELEMENT_RANGE.FirstElementAddress[0] =
            (UCHAR)((element->ElementAddress + addressMapping->FirstElement[element->ElementType]) >> 8);
        cdb->INITIALIZE_ELEMENT_RANGE.FirstElementAddress[1] =
            (UCHAR)((element->ElementAddress + addressMapping->FirstElement[element->ElementType]) & 0xFF);

        cdb->INITIALIZE_ELEMENT_RANGE.NumberOfElements[0] = (UCHAR)(elementList->NumberOfElements >> 8);
        cdb->INITIALIZE_ELEMENT_RANGE.NumberOfElements[1] = (UCHAR)(elementList->NumberOfElements & 0xFF);

        //
        // Indicate whether to use bar code scanning.
        //

        cdb->INITIALIZE_ELEMENT_RANGE.NoBarCode = initElementStatus->BarCodeScan ? 0 : 1;

        srb->TimeOutValue = fdoExtension->TimeOutValue;
        srb->DataTransferLength = 0;

    }

    //
    // Send SCSI command (CDB) to device
    //

    status = ClassSendSrbSynchronous(DeviceObject,
                                         srb,
                                         NULL,
                                         0,
                                         FALSE);

    if (NT_SUCCESS(status)) {
        Irp->IoStatus.Information = sizeof(CHANGER_INITIALIZE_ELEMENT_STATUS);
    }

    ChangerClassFreePool(srb);
    return status;
}


NTSTATUS
ChangerSetPosition(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    This routine issues the appropriate command to set the robotic mechanism to the specified
    element address. Normally used to optimize moves or exchanges by pre-positioning the picker.

Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/

{
    PFUNCTIONAL_DEVICE_EXTENSION   fdoExtension = DeviceObject->DeviceExtension;
    PCHANGER_DATA       changerData = (PCHANGER_DATA)(fdoExtension->CommonExtension.DriverData);
    PCHANGER_ADDRESS_MAPPING addressMapping = &(changerData->AddressMapping);
    PCHANGER_SET_POSITION setPosition = Irp->AssociatedIrp.SystemBuffer;
    USHORT              transport;
    USHORT              destination;
    PSCSI_REQUEST_BLOCK srb;
    PCDB                cdb;
    NTSTATUS            status;


    //
    // Verify transport, source, and dest. are within range.
    // Convert from 0-based to device-specific addressing.
    //

    transport = (USHORT)(setPosition->Transport.ElementAddress);

    if (ElementOutOfRange(addressMapping, transport, ChangerTransport)) {

        DebugPrint((1,
                   "ChangerSetPosition: Transport element out of range.\n"));

        return STATUS_ILLEGAL_ELEMENT_ADDRESS;
    }

    destination = (USHORT)(setPosition->Destination.ElementAddress);

    if (ElementOutOfRange(addressMapping, destination, setPosition->Destination.ElementType)) {
        DebugPrint((1,
                   "ChangerSetPosition: Destination element out of range.\n"));

        return STATUS_ILLEGAL_ELEMENT_ADDRESS;
    }

    //
    // Convert to device addresses.
    //

    transport += addressMapping->FirstElement[ChangerTransport];
    destination += addressMapping->FirstElement[setPosition->Destination.ElementType];

    //
    // The Scalars don't support 2-sided media.
    //

    if (setPosition->Flip) {
        return STATUS_INVALID_PARAMETER;
    }

    //
    // Build srb and cdb.
    //

    srb = ChangerClassAllocatePool(NonPagedPool, SCSI_REQUEST_BLOCK_SIZE);

    if (!srb) {

        return STATUS_INSUFFICIENT_RESOURCES;
    }

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;

    srb->CdbLength = CDB10GENERIC_LENGTH;
    cdb->POSITION_TO_ELEMENT.OperationCode = SCSIOP_POSITION_TO_ELEMENT;

    //
    // Build device-specific addressing.
    //

    cdb->POSITION_TO_ELEMENT.TransportElementAddress[0] = (UCHAR)(transport >> 8);
    cdb->POSITION_TO_ELEMENT.TransportElementAddress[1] = (UCHAR)(transport & 0xFF);

    cdb->POSITION_TO_ELEMENT.DestinationElementAddress[0] = (UCHAR)(destination >> 8);
    cdb->POSITION_TO_ELEMENT.DestinationElementAddress[1] = (UCHAR)(destination & 0xFF);

    //
    // Doesn't support two-sided media, but as a ref. source base, it should be noted.
    //

    cdb->POSITION_TO_ELEMENT.Flip = setPosition->Flip;


    srb->DataTransferLength = 0;
    srb->TimeOutValue = 200;

    //
    // Send SCSI command (CDB) to device
    //

    status = ClassSendSrbSynchronous(DeviceObject,
                                         srb,
                                         NULL,
                                         0,
                                         TRUE);

    if (NT_SUCCESS(status)) {
        Irp->IoStatus.Information = sizeof(CHANGER_SET_POSITION);
    }

    ChangerClassFreePool(srb);
    return status;
}


NTSTATUS
ChangerExchangeMedium(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    None of the Scalars units support exchange medium.

Arguments:

    DeviceObject
    Irp

Return Value:

    STATUS_INVALID_DEVICE_REQUEST

--*/

{
    return STATUS_INVALID_DEVICE_REQUEST;
}


NTSTATUS
ChangerMoveMedium(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:


Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/


{
    PFUNCTIONAL_DEVICE_EXTENSION   fdoExtension = DeviceObject->DeviceExtension;
    PCHANGER_DATA       changerData = (PCHANGER_DATA)(fdoExtension->CommonExtension.DriverData);
    PCHANGER_ADDRESS_MAPPING addressMapping = &(changerData->AddressMapping);
    PCHANGER_MOVE_MEDIUM moveMedium = Irp->AssociatedIrp.SystemBuffer;
    USHORT              transport;
    USHORT              source;
    USHORT              destination;
    PSCSI_REQUEST_BLOCK srb;
    PCDB                cdb;
    NTSTATUS            status, moveStatus;

    //
    // Verify transport, source, and dest. are within range.
    // Convert from 0-based to device-specific addressing.
    //

    transport = (USHORT)(moveMedium->Transport.ElementAddress);

    if (ElementOutOfRange(addressMapping, transport, ChangerTransport)) {

        DebugPrint((1,
                   "ChangerMoveMedium: Transport element out of range.\n"));

        return STATUS_ILLEGAL_ELEMENT_ADDRESS;
    }

    source = (USHORT)(moveMedium->Source.ElementAddress);

    if (ElementOutOfRange(addressMapping, source, moveMedium->Source.ElementType)) {

        DebugPrint((1,
                   "ChangerMoveMedium: Source element out of range.\n"));

        return STATUS_ILLEGAL_ELEMENT_ADDRESS;
    }

    destination = (USHORT)(moveMedium->Destination.ElementAddress);

    if (ElementOutOfRange(addressMapping, destination, moveMedium->Destination.ElementType)) {
        DebugPrint((1,
                   "ChangerMoveMedium: Destination element out of range.\n"));

        return STATUS_ILLEGAL_ELEMENT_ADDRESS;
    }

    //
    // Convert to device addresses.
    //

    transport += addressMapping->FirstElement[ChangerTransport];
    source += addressMapping->FirstElement[moveMedium->Source.ElementType];
    destination += addressMapping->FirstElement[moveMedium->Destination.ElementType];

    //
    // ADICs don't support 2-sided media.
    //

    if (moveMedium->Flip) {
        return STATUS_INVALID_PARAMETER;
    }

    //
    // Build srb and cdb.
    //

    srb = ExAllocatePool(NonPagedPool, SCSI_REQUEST_BLOCK_SIZE);

    if (!srb) {
        return STATUS_INSUFFICIENT_RESOURCES;
    }

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;


    // Pre-MoveMedium Locking ? =========================================

    // if source or destination involved IEPORT, lock the IEPORT first
    if ((moveMedium->Source.ElementType == ChangerIEPort) || 
        (moveMedium->Destination.ElementType == ChangerIEPort)) {

        srb->CdbLength = CDB6GENERIC_LENGTH;
        cdb->MEDIA_REMOVAL.OperationCode = SCSIOP_MEDIUM_REMOVAL;
        srb->DataBuffer = NULL;
        srb->DataTransferLength = 0;
        srb->TimeOutValue = 10;

        // lock the IEPORT !
        cdb->MEDIA_REMOVAL.Prevent = 1;
        status = ClassSendSrbSynchronous(DeviceObject,
                                             srb,
                                             srb->DataBuffer,
                                             srb->DataTransferLength,
                                             FALSE);
        if (!NT_SUCCESS(status)) {
           DebugPrint((0,
                       "Pre-MoveMedium Locking failed : ",
                       status));
        }
    }



    // MoveMedium  =========================================

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
    cdb = (PCDB)srb->Cdb;
    srb->CdbLength = CDB12GENERIC_LENGTH;
    srb->TimeOutValue = fdoExtension->TimeOutValue;

    cdb->MOVE_MEDIUM.OperationCode = SCSIOP_MOVE_MEDIUM;

    cdb->MOVE_MEDIUM.TransportElementAddress[0] = (UCHAR)(transport >> 8);
    cdb->MOVE_MEDIUM.TransportElementAddress[1] = (UCHAR)(transport & 0xFF);

    cdb->MOVE_MEDIUM.SourceElementAddress[0] = (UCHAR)(source >> 8);
    cdb->MOVE_MEDIUM.SourceElementAddress[1] = (UCHAR)(source & 0xFF);

    cdb->MOVE_MEDIUM.DestinationElementAddress[0] = (UCHAR)(destination >> 8);
    cdb->MOVE_MEDIUM.DestinationElementAddress[1] = (UCHAR)(destination & 0xFF);

    cdb->MOVE_MEDIUM.Flip = moveMedium->Flip;
    srb->DataTransferLength = 0;
    moveStatus = ClassSendSrbSynchronous(DeviceObject,
                                         srb,
                                         NULL,
                                         0,
                                         FALSE);

    if (NT_SUCCESS(moveStatus)) {
        Irp->IoStatus.Information = sizeof(CHANGER_MOVE_MEDIUM);
    } 

    // Post-MoveMedium UnLocking ? =========================================

    // if source or destination involved IEPORT, unlock the IEPORT
    if ((moveMedium->Source.ElementType == ChangerIEPort) || 
        (moveMedium->Destination.ElementType == ChangerIEPort)) {

        RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);
        srb->CdbLength = CDB6GENERIC_LENGTH;
        cdb->MEDIA_REMOVAL.OperationCode = SCSIOP_MEDIUM_REMOVAL;
        srb->DataBuffer = NULL;
        srb->DataTransferLength = 0;
        srb->TimeOutValue = 10;

        // unlock the IEPORT !
        cdb->MEDIA_REMOVAL.Prevent = 0;
        status = ClassSendSrbSynchronous(DeviceObject,
                                             srb,
                                             srb->DataBuffer,
                                             srb->DataTransferLength,
                                             FALSE);
        if (!NT_SUCCESS(status)) {
           DebugPrint((0,
                       "Post-MoveMedium UnLocking failed : ",
                       status));
        }
    }

    ExFreePool(srb);
    return moveStatus;
}


NTSTATUS
ChangerReinitializeUnit(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:


Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/

{
    return STATUS_INVALID_DEVICE_REQUEST;
}


NTSTATUS
ChangerQueryVolumeTags(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:


Arguments:

    DeviceObject
    Irp

Return Value:

    NTSTATUS

--*/

{

    return STATUS_INVALID_DEVICE_REQUEST;
}


NTSTATUS
AdicBuildAddressMapping(
    IN PDEVICE_OBJECT DeviceObject
    )

/*++

Routine Description:

    This routine issues the appropriate mode sense commands and builds an
    array of element addresses. These are used to translate between the device-specific
    addresses and the zero-based addresses of the API.

Arguments:

    DeviceObject

Return Value:

    NTSTATUS

--*/
{

    PFUNCTIONAL_DEVICE_EXTENSION      fdoExtension = DeviceObject->DeviceExtension;
    PCHANGER_DATA          changerData = (PCHANGER_DATA)(fdoExtension->CommonExtension.DriverData);
    PCHANGER_ADDRESS_MAPPING addressMapping = &changerData->AddressMapping;
    PSCSI_REQUEST_BLOCK    srb;
    PCDB                   cdb;
    NTSTATUS               status;
    PMODE_ELEMENT_ADDRESS_PAGE elementAddressPage;
    PVOID modeBuffer;
    ULONG i;

    srb = ChangerClassAllocatePool(NonPagedPool, SCSI_REQUEST_BLOCK_SIZE);
    if (!srb) {
        return STATUS_INSUFFICIENT_RESOURCES;
    }

    //
    // Set all FirstElements to NO_ELEMENT.
    //

    for (i = 0; i < ChangerMaxElement; i++) {
        addressMapping->FirstElement[i] = ADIC_NO_ELEMENT;
    }

    RtlZeroMemory(srb, SCSI_REQUEST_BLOCK_SIZE);

    cdb = (PCDB)srb->Cdb;

    //
    // Build a mode sense - Element address assignment page.
    //

    modeBuffer = ChangerClassAllocatePool(NonPagedPoolCacheAligned, sizeof(MODE_PARAMETER_HEADER)
                                + sizeof(MODE_ELEMENT_ADDRESS_PAGE));
    if (!modeBuffer) {
        return STATUS_INSUFFICIENT_RESOURCES;
    }


    RtlZeroMemory(modeBuffer, sizeof(MODE_PARAMETER_HEADER) + sizeof(MODE_ELEMENT_ADDRESS_PAGE));
    srb->CdbLength = CDB6GENERIC_LENGTH;
    srb->TimeOutValue = 20;
    srb->DataTransferLength = sizeof(MODE_PARAMETER_HEADER) + sizeof(MODE_ELEMENT_ADDRESS_PAGE);
    srb->DataBuffer = modeBuffer;

    cdb->MODE_SENSE.OperationCode = SCSIOP_MODE_SENSE;
    cdb->MODE_SENSE.PageCode = MODE_PAGE_ELEMENT_ADDRESS;
    cdb->MODE_SENSE.Dbd = 1;
    cdb->MODE_SENSE.AllocationLength = (UCHAR)srb->DataTransferLength;

    //
    // Send the request.
    //

    status = ClassSendSrbSynchronous(DeviceObject,
                                         srb,
                                         srb->DataBuffer,
                                         srb->DataTransferLength,
                                         FALSE);


    elementAddressPage = modeBuffer;
    (PCHAR)elementAddressPage += sizeof(MODE_PARAMETER_HEADER);

    if (NT_SUCCESS(status)) {

        //
        // Build address mapping.
        //

        addressMapping->FirstElement[ChangerTransport] = (elementAddressPage->MediumTransportElementAddress[0] << 8) |
                                                          elementAddressPage->MediumTransportElementAddress[1];
        addressMapping->FirstElement[ChangerDrive] = (elementAddressPage->FirstDataXFerElementAddress[0] << 8) |
                                                      elementAddressPage->FirstDataXFerElementAddress[1];
        addressMapping->FirstElement[ChangerIEPort] = (elementAddressPage->FirstIEPortElementAddress[0] << 8) |
                                                       elementAddressPage->FirstIEPortElementAddress[1];
        addressMapping->FirstElement[ChangerSlot] = (elementAddressPage->FirstStorageElementAddress[0] << 8) |
                                                     elementAddressPage->FirstStorageElementAddress[1];
        addressMapping->FirstElement[ChangerDoor] = 0;

        addressMapping->FirstElement[ChangerKeypad] = 0;

        addressMapping->NumberOfElements[ChangerTransport] = elementAddressPage->NumberTransportElements[1];
        addressMapping->NumberOfElements[ChangerTransport] |= (elementAddressPage->NumberTransportElements[0] << 8);

        addressMapping->NumberOfElements[ChangerDrive] = elementAddressPage->NumberDataXFerElements[1];
        addressMapping->NumberOfElements[ChangerDrive] |= (elementAddressPage->NumberDataXFerElements[0] << 8);

        addressMapping->NumberOfElements[ChangerIEPort] = elementAddressPage->NumberIEPortElements[1];
        addressMapping->NumberOfElements[ChangerIEPort] |= (elementAddressPage->NumberIEPortElements[0] << 8);

        addressMapping->NumberOfElements[ChangerSlot] = elementAddressPage->NumberStorageElements[1];
        addressMapping->NumberOfElements[ChangerSlot] |= (elementAddressPage->NumberStorageElements[0] << 8);

        addressMapping->NumberOfElements[ChangerDoor] = 1;
        addressMapping->NumberOfElements[ChangerKeypad] = 1;

        addressMapping->Initialized = TRUE;

        //
        // Determine the lowest element address for use with AllElements.
        //

        for (i = 0; i < ChangerDrive; i++) {
            if (addressMapping->FirstElement[i] < addressMapping->FirstElement[AllElements]) {

                DebugPrint((1,
                           "BuildAddressMapping: New lowest address %x\n",
                           addressMapping->FirstElement[i]));
                addressMapping->FirstElement[AllElements] = addressMapping->FirstElement[i];
            }
        }
    }



    //
    // Free buffer.
    //

    ChangerClassFreePool(modeBuffer);
    ChangerClassFreePool(srb);

    return status;
}


ULONG
MapExceptionCodes(
    IN PADICS_ELEMENT_DESCRIPTOR ElementDescriptor
    )

/*++

Routine Description:

    This routine takes the sense data from the elementDescriptor and creates
    the appropriate bitmap of values.

Arguments:

   ElementDescriptor - pointer to the descriptor page.

Return Value:

    Bit-map of exception codes.

--*/

{
    UCHAR asq = ElementDescriptor->AddSenseCodeQualifier;
    UCHAR asc = ElementDescriptor->AdditionalSenseCode;
    ULONG exceptionCode = 0;

    switch (asc) {
        case 0x00:

            //
            // No error.
            //

            exceptionCode = 0;
            break;

        case 0x83:
            if (asq == 0x03) {
                exceptionCode = ERROR_LABEL_QUESTIONABLE;
            }
            break;

        default:
            exceptionCode = ERROR_UNHANDLED_ERROR;
            break;
    }

    DebugPrint((1,
               "adicsmc: MapExceptionCode - ASC %x, ASCQ %x ExceptionCode %x\n",
               asc,
               asq,
               exceptionCode));

    return exceptionCode;

}


BOOLEAN
ElementOutOfRange(
    IN PCHANGER_ADDRESS_MAPPING AddressMap,
    IN USHORT ElementOrdinal,
    IN ELEMENT_TYPE ElementType
    )
/*++

Routine Description:

    This routine determines whether the element address passed in is within legal range for
    the device.

Arguments:

    AddressMap - The dds' address map array
    ElementOrdinal - Zero-based address of the element to check.
    ElementType

Return Value:

    TRUE if out of range

--*/
{

    if (ElementOrdinal >= AddressMap->NumberOfElements[ElementType]) {

        DebugPrint((0,
                   "ElementOutOfRange: Type %x, Ordinal %x, Max %x\n",
                   ElementType,
                   ElementOrdinal,
                   AddressMap->NumberOfElements[ElementType]));
        return TRUE;
    } else if (AddressMap->FirstElement[ElementType] == ADIC_NO_ELEMENT) {

        DebugPrint((1,
                   "ElementOutOfRange: No Type %x present\n",
                   ElementType));

        return TRUE;
    }

    return FALSE;
}

