PortAccess.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 2004-2006 Spiro Trikaliotis
 *
 */

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

static NTSTATUS
ParPortIoctlInOut(IN PDEVICE_EXTENSION Pdx, IN ULONG Ioctl, 
                  IN PVOID InBuffer, IN ULONG InBufferLength, 
                  OUT PVOID OutBuffer, IN ULONG OutBufferLength)
{
    IO_STATUS_BLOCK ioStatusBlock;
    NTSTATUS ntStatus;
    KEVENT event;   // event to be signalled when the IOCTL has finished
    PIRP irp;

    FUNC_ENTER();

    // Initialize the event which we will use to be notified
    // when the IRP has finished

    DBG_IRQL( == PASSIVE_LEVEL);
    KeInitializeEvent(&event, NotificationEvent, FALSE);

    ntStatus = STATUS_SUCCESS;

    // build an IRP for this IOCTL

    DBG_IRQL( == PASSIVE_LEVEL);
    irp = IoBuildDeviceIoControlRequest(
        Ioctl,
        Pdx->ParallelPortFdo,
        InBuffer,
        InBufferLength,
        OutBuffer,
        OutBufferLength,
        TRUE,           // it's an internal device control
        &event,
        &ioStatusBlock
        );

    if (irp)
    {
        PIO_STACK_LOCATION irpStack;

        // get the current IRP stack location

        DBG_IRQL( <= DISPATCH_LEVEL);
        irpStack = IoGetNextIrpStackLocation(irp);

        // Reference the file object we are about to call.
        // This ensures the driver is not removed while we call it,
        // even if the underlying hardware is removed

        DBG_IRQL( <= DISPATCH_LEVEL);
        ObReferenceObject(Pdx->ParallelPortFileObject);

        // tell the IRP stack location to which file object we are
        // referring

        irpStack->FileObject = Pdx->ParallelPortFileObject;

        // Call the driver to perform the requested IOCTL

        DBG_IRQL( <= DISPATCH_LEVEL);
        ntStatus = IoCallDriver(Pdx->ParallelPortFdo, irp);

        // We're done, we can dereference the file object again

        DBG_IRQL( <= DISPATCH_LEVEL);
        ObDereferenceObject(Pdx->ParallelPortFileObject);

        if (!NT_SUCCESS(ntStatus))
        {
            DBG_WARN((DBG_PREFIX "IoCallDriver FAILED!"));
        }
        else 
        {
            // wait for the IRP to be completed

            DBG_IRQL( <= DISPATCH_LEVEL /* = only if timeout of NULL */);
            ntStatus = KeWaitForSingleObject(
               &event, 
               Executive, 
               KernelMode, 
               FALSE, // we are not alertable
               NULL);

            if (!NT_SUCCESS(ntStatus)) 
            {
                DBG_WARN((DBG_PREFIX "KeWaitForSingleObject FAILED!"));
            }
        }
    }

    FUNC_LEAVE_NTSTATUS(ntStatus);
}

NTSTATUS
ParPortAllocate(PDEVICE_EXTENSION Pdx)
{
    NTSTATUS ntStatus;

    FUNC_ENTER();

    DBG_ASSERT(Pdx);
    DBG_ASSERT(Pdx->ParallelPortAllocated == FALSE);

    // allocate the parallel port

    ntStatus = ParPortIoctlInOut(Pdx, IOCTL_INTERNAL_PARALLEL_PORT_ALLOCATE,
                                 NULL, 0, NULL, 0);

    // if we were successfull, remember this in the pdx

    if (NT_SUCCESS(ntStatus))
    {
        Pdx->ParallelPortAllocated = TRUE;
    }

    FUNC_LEAVE_NTSTATUS(ntStatus);
}

NTSTATUS
ParPortFree(PDEVICE_EXTENSION Pdx)
{
    NTSTATUS ntStatus = STATUS_SUCCESS;

    FUNC_ENTER();

    DBG_IRQL( == PASSIVE_LEVEL);

    DBG_ASSERT(Pdx != NULL);

    if (Pdx->ParallelPortAllocated == TRUE)
    {
        // Free the parallel port. An old implementation (v0.03) used
        // IOCTL_INTERNAL_PARALLEL_PORT_FREE. But this is available only
        // on WDM, that is, W2000, WXP, and above. In fact, MS specifically
        // discourages using that IOCTL, and tells us to use FreePort() 
        // instead.
        // Anyway, since I don't know what Microsoft will think in the future,
        // I decided to keep the old implementation, too.

#if 1
        Pdx->PortInfo->FreePort(Pdx->PortInfo->Context);
#else
        #error THIS IS ONLY AVAILABLE ON WDM! Thus, don't use it! (see comment above)
        ntStatus = ParPortIoctlInOut(Pdx, IOCTL_INTERNAL_PARALLEL_PORT_FREE,
                                     NULL, 0, NULL, 0);
#endif

        Pdx->ParallelPortAllocated = FALSE;
    }

    FUNC_LEAVE_NTSTATUS(ntStatus);

}

NTSTATUS
ParPortInit(PUNICODE_STRING ParallelPortName, PDEVICE_EXTENSION Pdx)
{
    NTSTATUS ntStatus;

    FUNC_ENTER();

    DBG_ASSERT(ParallelPortName);
    DBG_ASSERT(Pdx);

    // First of all, get the PDEVICE_OBJECT of the parallel port driver

    DBG_IRQL( == PASSIVE_LEVEL);
    ntStatus = IoGetDeviceObjectPointer(ParallelPortName, 
                                        FILE_READ_ATTRIBUTES,
                                        &Pdx->ParallelPortFileObject,
                                        &Pdx->ParallelPortFdo);

    if (!NT_SUCCESS(ntStatus))
    {
        DBG_WARN((DBG_PREFIX "IoGetDeviceObjectPointer() FAILED!"));
        FUNC_LEAVE_NTSTATUS(ntStatus);
    }

    // Allocate memory to hold to parallel port info

    DBG_IRQL( == PASSIVE_LEVEL);
    Pdx->PortInfo = (PPARALLEL_PORT_INFORMATION) ExAllocatePoolWithTag(NonPagedPool, 
        sizeof(*Pdx->PortInfo), MTAG_PPINFO);

    // If we got memory, get the info out of the parallel port driver

    if (Pdx->PortInfo)
    {
        ntStatus = ParPortIoctlInOut(Pdx, IOCTL_INTERNAL_GET_PARALLEL_PORT_INFO,
                                     NULL, 0,
                                     Pdx->PortInfo, sizeof(*Pdx->PortInfo));
    }
    else
    {
        ntStatus = STATUS_INSUFFICIENT_RESOURCES;
    }

    if (NT_SUCCESS(ntStatus))
    {
        Pdx->ParPortPortAddress = Pdx->PortInfo->Controller;
        DBG_PPORT((DBG_PREFIX "Got parallel port information:"));
        DBG_PPORT((DBG_PREFIX "- OriginalController = 0x%p", Pdx->PortInfo->OriginalController));
        DBG_PPORT((DBG_PREFIX "- Controller         = 0x%p", Pdx->PortInfo->Controller));
        DBG_PPORT((DBG_PREFIX "- Span of controller = 0x%08x", Pdx->PortInfo->SpanOfController));
        DBG_PPORT((DBG_PREFIX "- TryAllocatePort    = 0x%p", Pdx->PortInfo->TryAllocatePort));
        DBG_PPORT((DBG_PREFIX "- FreePort           = 0x%p", Pdx->PortInfo->FreePort));
        DBG_PPORT((DBG_PREFIX "- QueryNumWaiters    = 0x%p", Pdx->PortInfo->QueryNumWaiters));
        DBG_PPORT((DBG_PREFIX "- Context            = 0x%p", Pdx->PortInfo->Context));
    }

    // if we failed getting the parallel port info, but there was memory
    // allocated, free the memory.

    if (!NT_SUCCESS(ntStatus) && Pdx->PortInfo)
    {
        DBG_IRQL( < DISPATCH_LEVEL);
        ExFreePool(Pdx->PortInfo);
        Pdx->PortInfo = NULL;
    }

    FUNC_LEAVE_NTSTATUS(ntStatus);
}

NTSTATUS
ParPortDeinit(PDEVICE_EXTENSION Pdx)
{
    FUNC_ENTER();

    DBG_IRQL( <= DISPATCH_LEVEL);

    // If the file object was previously referenced
    // (to make sure the parallel port driver is not
    // removed while we access it), dereference it now.

    if (Pdx->ParallelPortFileObject)
    {
        DBG_IRQL( <= DISPATCH_LEVEL);
        ObDereferenceObject(Pdx->ParallelPortFileObject);
        Pdx->ParallelPortFileObject = NULL;
    }

    // If we allocated memory for the parallel port info,
    // free that now.
    if (Pdx->PortInfo)
    {
        DBG_IRQL( < DISPATCH_LEVEL);
        ExFreePool(Pdx->PortInfo);
        Pdx->PortInfo = NULL;
    }

    FUNC_LEAVE_NTSTATUS_CONST(STATUS_SUCCESS);
}

#define DBG_PPORT_VERBOSE( _yy, _xxx, _type) \
            DBG_PPORT((DBG_PREFIX " --- " #_xxx " = " _type, PnpInfo->_xxx))

static BOOLEAN
ParPortGetPnpInformation(PDEVICE_EXTENSION Pdx, PPARALLEL_PNP_INFORMATION PnpInfo)
{
    NTSTATUS ntStatus;
    BOOLEAN success;

    FUNC_ENTER();

    // get the PNP, ECP and EPP info out of the parallel port

    ntStatus = ParPortIoctlInOut(Pdx, IOCTL_INTERNAL_GET_PARALLEL_PNP_INFO,
        NULL, 0, PnpInfo, sizeof(*PnpInfo));

    if (!NT_SUCCESS(ntStatus))
    {
        // It is no problem if this fails. It only means we do not have to worry
        // about ECP and EPP modes

        DBG_WARN((DBG_PREFIX "IOCTL_INTERNAL_GET_PARALLEL_PNP_INFO FAILED with %s", DebugNtStatus(ntStatus)));

        success = FALSE;
    }
    else
    {
        success = TRUE;

        // Output some diagnostics for debugging purposes:

        DBG_PPORT((DBG_PREFIX "IOCTL_INTERNAL_GET_PARALLEL_PNP_INFO:"));
        DBG_PPORT((DBG_PREFIX "EcpController = 0x%p", PnpInfo->EcpController));

        DBG_PPORT_VERBOSE(PHYSICAL_ADDRESS, OriginalEcpController, "0x%p");
        DBG_PPORT_VERBOSE(PUCHAR, EcpController, "0x%p");
        DBG_PPORT_VERBOSE(ULONG, SpanOfEcpController, "%u");
        DBG_PPORT_VERBOSE(ULONG, PortNumber, "%u (deprecated, do not use!)");
        DBG_PPORT_VERBOSE(ULONG, HardwareCapabilities, "%u");
        DBG_PPORT_VERBOSE(PPARALLEL_SET_CHIP_MODE, TrySetChipMode, "0x%p");
        DBG_PPORT_VERBOSE(PPARALLEL_CLEAR_CHIP_MODE, ClearChipMode, "0x%p");
        DBG_PPORT_VERBOSE(ULONG, FifoDepth, "%u");
        DBG_PPORT_VERBOSE(ULONG, FifoWidth, "%u");
        DBG_PPORT_VERBOSE(PHYSICAL_ADDRESS, EppControllerPhysicalAddress, "0x%p");
        DBG_PPORT_VERBOSE(ULONG, SpanOfEppController, "%u");
        DBG_PPORT_VERBOSE(ULONG, Ieee1284_3DeviceCount, "%u");
        DBG_PPORT_VERBOSE(PPARALLEL_TRY_SELECT_ROUTINE, TrySelectDevice, "0x%p");
        DBG_PPORT_VERBOSE(PPARALLEL_DESELECT_ROUTINE, DeselectDevice, "0x%p");
        DBG_PPORT_VERBOSE(PVOID, Context, "0x%p");
        DBG_PPORT_VERBOSE(ULONG, CurrentMode, "0x%04x");
        DBG_PPORT_VERBOSE(PWSTR, PortName, "%ws")
    }

    FUNC_LEAVE_BOOLEAN(success);
}
#undef DBG_PPORT_VERBOSE

NTSTATUS
ParPortSetModeWdm(PDEVICE_EXTENSION Pdx)
{
    PARALLEL_PNP_INFORMATION pnpInformation;
    NTSTATUS ntStatus;

    FUNC_ENTER();

    // do not assume success for the following

    ntStatus = STATUS_INVALID_PARAMETER;

    if (ParPortGetPnpInformation(Pdx, &pnpInformation))
    {
#if DBG
        PUCHAR ecr;

        if (pnpInformation.EcpController != 0)
        {
            ecr = pnpInformation.EcpController + ECR_OFFSET;

            DBG_PPORT((DBG_PREFIX "We're having an ECP controller: ECR = %08x", ecr));
            DBG_PPORT((DBG_PREFIX " --- ECR = %02x", READ_PORT_UCHAR(ecr)));
        }
#endif

        // now, we want to set the parallel port mode. This does only
        // make sense if we have functions for setting and clearing the
        // chip mode

        if (pnpInformation.TrySetChipMode && pnpInformation.ClearChipMode)
        {
            // Does our parallel port have the capability to be set into
            // byte mode? If not, it does not make sense to change the mode

            if (pnpInformation.HardwareCapabilities & PPT_BYTE_PRESENT)
            {
                DBG_PPORT((DBG_PREFIX "Trying to set Chip mode to BYTE MODE..."));

                // try to set the chip mode to byte mode

                DBG_IRQL( <= DISPATCH_LEVEL);
                ntStatus = pnpInformation.TrySetChipMode(pnpInformation.Context, ECR_BYTE_MODE);

                DBG_PPORT((DBG_PREFIX " --- TrySetChipMode returned with %s", DebugNtStatus(ntStatus)));
            }
            else
            {
                // no byte mode available. Thus, we want to make sure we have at
                // least SPP byte.

                DBG_PPORT((DBG_PREFIX "****************************** NO BYTE MODE PRESENT, making sure to have SPP mode!!!"));
                ParPortUnsetMode(Pdx);
            }
#if DBG
            if (pnpInformation.EcpController != 0)
            {
                DBG_PPORT((DBG_PREFIX " --- ECR = %02x", READ_PORT_UCHAR(ecr)));
            }
#endif
        }
        else
        {
            DBG_PPORT((DBG_PREFIX " --- TrySetChipMode or ClearChipmode not available!"));
        }
    }

    FUNC_LEAVE_NTSTATUS(ntStatus);
}

NTSTATUS
ParPortUnsetModeWdm(PDEVICE_EXTENSION Pdx)
{
    PARALLEL_PNP_INFORMATION pnpInformation;
    NTSTATUS ntStatus;

    FUNC_ENTER();

    // assume we have success in the following

    ntStatus = STATUS_SUCCESS;

    if (ParPortGetPnpInformation(Pdx, &pnpInformation))
    {
#if DBG
        PUCHAR ecr;

        if (pnpInformation.EcpController != 0)
        {
            ecr = pnpInformation.EcpController + ECR_OFFSET;

            DBG_PPORT((DBG_PREFIX "We're having an ECP controller: ECR = %08x", ecr));

            DBG_PPORT((DBG_PREFIX " --- ECR = %02x", READ_PORT_UCHAR(ecr)));
        }
#endif

        // If we have the ClearChipMode function, try to unset the last set mode

        if (pnpInformation.ClearChipMode)
        {
            DBG_PPORT((DBG_PREFIX "Trying to unset Chip mode..."));

            DBG_IRQL( <= DISPATCH_LEVEL);
            ntStatus = pnpInformation.ClearChipMode(
                pnpInformation.Context, 
                (UCHAR) pnpInformation.CurrentMode);

            DBG_PPORT((DBG_PREFIX " --- ClearChipMode returned with %s", DebugNtStatus(ntStatus)));

            // If we did not have success, this is no problem.
            // This means that we did not set the mode in the first place,
            // thus, ignore that error.

            if (ntStatus == STATUS_UNSUCCESSFUL)
            {
                ntStatus = STATUS_SUCCESS;
            }
        }

#if DBG
        if (pnpInformation.EcpController != 0)
        {
            DBG_PPORT((DBG_PREFIX " --- ECR = %02x", READ_PORT_UCHAR(ecr)));
        }
#endif
    }

    FUNC_LEAVE_NTSTATUS(ntStatus);
}

NTSTATUS
ParPortAllocInterrupt(PDEVICE_EXTENSION Pdx, PKSERVICE_ROUTINE Isr)
{
    NTSTATUS ntStatus;

    FUNC_ENTER();

    DBG_IRQL( == PASSIVE_LEVEL);

    DBG_ASSERT(Pdx);
    DBG_ASSERT(Isr);
    DBG_ASSERT(Pdx->ParallelPortAllocatedInterrupt == FALSE);

    Pdx->Pisr.InterruptServiceRoutine = Isr;
    Pdx->Pisr.InterruptServiceContext = Pdx;
    Pdx->Pisr.DeferredPortCheckRoutine = NULL;
    Pdx->Pisr.DeferredPortCheckContext = NULL;

    // try to allocate the interrupt via the IOCTL

    ntStatus = ParPortIoctlInOut(Pdx, IOCTL_INTERNAL_PARALLEL_CONNECT_INTERRUPT,
                                 &Pdx->Pisr, sizeof(Pdx->Pisr),
                                 &Pdx->Pii, sizeof(Pdx->Pii));

    // If we had success, remember this in the Pdx.

    if (NT_SUCCESS(ntStatus))
    {
        Pdx->ParallelPortAllocatedInterrupt = TRUE;
    }
    else
    {
        DBG_WARN((DBG_PREFIX "Allocation of Interrupt FAILED!"));
        LogErrorOnly(Pdx->Fdo, CBM_NO_ISR);
    }

    FUNC_LEAVE_NTSTATUS(ntStatus);
}

NTSTATUS
ParPortFreeInterrupt(PDEVICE_EXTENSION Pdx)
{
    NTSTATUS ntStatus;

    FUNC_ENTER();

    DBG_IRQL( == PASSIVE_LEVEL);

    DBG_ASSERT(Pdx);

    // If the interrupt was previously allocated, free that

    if (Pdx->ParallelPortAllocatedInterrupt == TRUE)
    {
        ntStatus = ParPortIoctlInOut(Pdx, IOCTL_INTERNAL_PARALLEL_DISCONNECT_INTERRUPT,
                                     &Pdx->Pisr, sizeof(Pdx->Pisr),
                                     NULL, 0);

        Pdx->ParallelPortAllocatedInterrupt = FALSE;
    }
    else
    {
        // If we did not have any interrupt, this function was successfull,
        // thus, report this as return value.

        ntStatus = STATUS_SUCCESS;
    }

    FUNC_LEAVE_NTSTATUS(ntStatus);
}

NTSTATUS
ParPortAllowInterruptIoctl(PDEVICE_EXTENSION Pdx)
{
    PDEVICE_OBJECT pdo;
    NTSTATUS ntStatus;
    HANDLE handleReg;
    ULONG OldStateEnableConnectInterruptIoctl;
    ULONG OldStateFilterResourceMethod;

    FUNC_ENTER();

    DBG_ASSERT(Pdx);

    // open the hardware key to the parallel port

    ntStatus = cbm_registry_open_hardwarekey(&handleReg, &pdo, Pdx);

    if (NT_SUCCESS(ntStatus))
    {
        // We could open the hardware key. Now, we get the old values,
        // and set the values we need.

        // EnableConnectInterruptIoctl allows us to issue the
        // IOCTL, or it blocks us. If this registry key is not set,
        // the parport driver will not even consider to let us obtain
        // the interrupt.
        // The possible values are:
        // - 0: The IOCTL is forbidden (default)
        // - else: The IOCTL is allowed
        // This value is tested with every call to the IOCTL

        ntStatus = cbm_registry_read_ulong(handleReg, L"EnableConnectInterruptIoctl",
            &OldStateEnableConnectInterruptIoctl);

        // If the value was not there, remember it in the OldState var

        if (ntStatus == STATUS_OBJECT_NAME_NOT_FOUND)
        {
            OldStateEnableConnectInterruptIoctl = -1;
            ntStatus = STATUS_SUCCESS;
        }

        // FilterResourceMethod tells the parallel port if it should try
        // to get the interrupt itself in the first place. If the parallel port
        // does not have an interrupt, we cannot obtain it ourselves.
        // The possible values are:
        // - 0: Try to not obtain the interrupt, if such a hardware
        //      configuration exists
        // - 1: Force not to use the interrupt (default)
        // - 2: Always use the interrupt
        // Unfortunately, this entry is only checked on device initialization.
        // Because of this, the parport needs to be restarted for this change
        // to take effect.

        ntStatus = cbm_registry_read_ulong(handleReg, L"FilterResourceMethod",
            &OldStateFilterResourceMethod);

        // If the value was not there, remember it in the OldState var

        if (ntStatus == STATUS_OBJECT_NAME_NOT_FOUND)
        {
            OldStateFilterResourceMethod = -1;
            ntStatus = STATUS_SUCCESS;
        }

        // If the registry entries had the wrong values, set them to the ones
        // we need here

        if (NT_SUCCESS(ntStatus) && OldStateEnableConnectInterruptIoctl != 1)
        {
            ntStatus = cbm_registry_write_ulong(handleReg, L"EnableConnectInterruptIoctl", 1);
        }

        if (NT_SUCCESS(ntStatus) && OldStateFilterResourceMethod != 2)
        {
            ntStatus = cbm_registry_write_ulong(handleReg, L"FilterResourceMethod", 2);
        }

        // we're done, we do not need the hardware key anymore

        cbm_registry_close_hardwarekey(handleReg, pdo);
    }

    FUNC_LEAVE_NTSTATUS(ntStatus);
}

---