misc.c

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/*
 * COPYRIGHT:       See COPYING in the top level directory
 * PROJECT:         Serial port driver
 * FILE:            drivers/dd/serial/misc.c
 * PURPOSE:         Miscellaneous operations
 *
 * PROGRAMMERS:     Hervé Poussineau (hpoussin@reactos.org)
 */
/* FIXME: call IoAcquireRemoveLock/IoReleaseRemoveLock around each I/O operation */

#include "serial.h"

#include <debug.h>


NTSTATUS NTAPI
ForwardIrpAndForget(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp)
{
    PDEVICE_OBJECT LowerDevice = ((PSERIAL_DEVICE_EXTENSION)DeviceObject->DeviceExtension)->LowerDevice;

    ASSERT(LowerDevice);

    IoSkipCurrentIrpStackLocation(Irp);
    return IoCallDriver(LowerDevice, Irp);
}

VOID NTAPI
SerialReceiveByte(
    IN PKDPC Dpc,
    IN PVOID pDeviceExtension, // real type PSERIAL_DEVICE_EXTENSION
    IN PVOID Unused1,
    IN PVOID Unused2)
{
    PSERIAL_DEVICE_EXTENSION DeviceExtension;
    PUCHAR ComPortBase;
    UCHAR Byte;
    KIRQL Irql;
    UCHAR IER;
    NTSTATUS Status;

    DeviceExtension = (PSERIAL_DEVICE_EXTENSION)pDeviceExtension;
    ComPortBase = ULongToPtr(DeviceExtension->BaseAddress);

    KeAcquireSpinLock(&DeviceExtension->InputBufferLock, &Irql);
    while (READ_PORT_UCHAR(SER_LSR(ComPortBase)) & SR_LSR_DATA_RECEIVED)
    {
        Byte = READ_PORT_UCHAR(SER_RBR(ComPortBase));
        INFO_(SERIAL, "Byte received on COM%lu: 0x%02x\n",
            DeviceExtension->ComPort, Byte);
        Status = PushCircularBufferEntry(&DeviceExtension->InputBuffer, Byte);
        if (NT_SUCCESS(Status))
            DeviceExtension->SerialPerfStats.ReceivedCount++;
        else
            DeviceExtension->SerialPerfStats.BufferOverrunErrorCount++;
    }
    KeSetEvent(&DeviceExtension->InputBufferNotEmpty, 0, FALSE);
    KeReleaseSpinLock(&DeviceExtension->InputBufferLock, Irql);

    /* allow new interrupts */
    IER = READ_PORT_UCHAR(SER_IER(ComPortBase));
    WRITE_PORT_UCHAR(SER_IER(ComPortBase), IER | SR_IER_DATA_RECEIVED);
}

VOID NTAPI
SerialSendByte(
    IN PKDPC Dpc,
    IN PVOID pDeviceExtension, // real type PSERIAL_DEVICE_EXTENSION
    IN PVOID Unused1,
    IN PVOID Unused2)
{
    PSERIAL_DEVICE_EXTENSION DeviceExtension;
    PUCHAR ComPortBase;
    UCHAR Byte;
    KIRQL Irql;
    UCHAR IER;
    NTSTATUS Status;

    DeviceExtension = (PSERIAL_DEVICE_EXTENSION)pDeviceExtension;
    ComPortBase = ULongToPtr(DeviceExtension->BaseAddress);

    KeAcquireSpinLock(&DeviceExtension->OutputBufferLock, &Irql);
    while (!IsCircularBufferEmpty(&DeviceExtension->OutputBuffer)
        && READ_PORT_UCHAR(SER_LSR(ComPortBase)) & SR_LSR_THR_EMPTY)
    {
        Status = PopCircularBufferEntry(&DeviceExtension->OutputBuffer, &Byte);
        if (!NT_SUCCESS(Status))
            break;
        WRITE_PORT_UCHAR(SER_THR(ComPortBase), Byte);
        INFO_(SERIAL, "Byte sent to COM%lu: 0x%02x\n",
            DeviceExtension->ComPort, Byte);
        DeviceExtension->SerialPerfStats.TransmittedCount++;
    }
    if (!IsCircularBufferEmpty(&DeviceExtension->OutputBuffer))
    {
        /* allow new interrupts */
        IER = READ_PORT_UCHAR(SER_IER(ComPortBase));
        WRITE_PORT_UCHAR(SER_IER(ComPortBase), IER | SR_IER_THR_EMPTY);
    }
    KeReleaseSpinLock(&DeviceExtension->OutputBufferLock, Irql);
}

VOID NTAPI
SerialCompleteIrp(
    IN PKDPC Dpc,
    IN PVOID pDeviceExtension, // real type PSERIAL_DEVICE_EXTENSION
    IN PVOID pIrp, // real type PIRP
    IN PVOID Unused)
{
    IoCompleteRequest((PIRP)pIrp, IO_NO_INCREMENT);
}

BOOLEAN NTAPI
SerialInterruptService(
    IN PKINTERRUPT Interrupt,
    IN OUT PVOID ServiceContext)
{
    PDEVICE_OBJECT DeviceObject;
    PSERIAL_DEVICE_EXTENSION DeviceExtension;
    PUCHAR ComPortBase;
    UCHAR Iir;
    ULONG Events = 0;
    BOOLEAN ret = FALSE;

    /* FIXME: sometimes, produce SERIAL_EV_RXFLAG event */

    DeviceObject = (PDEVICE_OBJECT)ServiceContext;
    DeviceExtension = (PSERIAL_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
    ComPortBase = ULongToPtr(DeviceExtension->BaseAddress);

    Iir = READ_PORT_UCHAR(SER_IIR(ComPortBase));
    if (Iir == 0xff)
        return TRUE;
    Iir &= SR_IIR_ID_MASK;
    if ((Iir & SR_IIR_SELF) != 0) { return FALSE; }

    switch (Iir)
    {
        case SR_IIR_MSR_CHANGE:
        {
            UCHAR MSR, IER;
            TRACE_(SERIAL, "SR_IIR_MSR_CHANGE\n");

            MSR = READ_PORT_UCHAR(SER_MSR(ComPortBase));
            if (MSR & SR_MSR_CTS_CHANGED)
            {
                if (MSR & SR_MSR_CTS)
                    KeInsertQueueDpc(&DeviceExtension->SendByteDpc, NULL, NULL);
                else
                {
                    ; /* FIXME: stop transmission */
                }
                Events |= SERIAL_EV_CTS;
            }
            if (MSR & SR_MSR_DSR_CHANGED)
            {
                if (MSR & SR_MSR_DSR)
                    KeInsertQueueDpc(&DeviceExtension->ReceivedByteDpc, NULL, NULL);
                else
                {
                    ; /* FIXME: stop reception */
                }
                Events |= SERIAL_EV_DSR;
            }
            if (MSR & SR_MSR_RI_CHANGED)
            {
                INFO_(SERIAL, "SR_MSR_RI_CHANGED changed: now %d\n", MSR & SI_MSR_RI);
                Events |= SERIAL_EV_RING;
            }
            if (MSR & SR_MSR_DCD_CHANGED)
            {
                INFO_(SERIAL, "SR_MSR_DCD_CHANGED changed: now %d\n", MSR & SR_MSR_DCD);
                Events |= SERIAL_EV_RLSD;
            }
            IER = READ_PORT_UCHAR(SER_IER(ComPortBase));
            WRITE_PORT_UCHAR(SER_IER(ComPortBase), IER | SR_IER_MSR_CHANGE);

            ret = TRUE;
            goto done;
        }
        case SR_IIR_THR_EMPTY:
        {
            TRACE_(SERIAL, "SR_IIR_THR_EMPTY\n");

            KeInsertQueueDpc(&DeviceExtension->SendByteDpc, NULL, NULL);
            Events |= SERIAL_EV_TXEMPTY;

            ret = TRUE;
            goto done;
        }
        case SR_IIR_DATA_RECEIVED:
        {
            ULONG AlreadyReceivedBytes, Limit;
            TRACE_(SERIAL, "SR_IIR_DATA_RECEIVED\n");

            KeInsertQueueDpc(&DeviceExtension->ReceivedByteDpc, NULL, NULL);
            Events |= SERIAL_EV_RXCHAR;

            /* Check if buffer will be 80% full */
            AlreadyReceivedBytes = GetNumberOfElementsInCircularBuffer(
                &DeviceExtension->InputBuffer) * 5;
            Limit = DeviceExtension->InputBuffer.Length * 4;
            if (AlreadyReceivedBytes < Limit && AlreadyReceivedBytes + 1 >= Limit)
            {
                /* Buffer is full at 80% */
                Events |= SERIAL_EV_RX80FULL;
            }

            ret = TRUE;
            goto done;
        }
        case SR_IIR_ERROR:
        {
            UCHAR LSR;
            TRACE_(SERIAL, "SR_IIR_ERROR\n");

            LSR = READ_PORT_UCHAR(SER_LSR(ComPortBase));
            if (LSR & SR_LSR_OVERRUN_ERROR)
            {
                InterlockedIncrement((PLONG)&DeviceExtension->SerialPerfStats.SerialOverrunErrorCount);
                Events |= SERIAL_EV_ERR;
            }
            if (LSR & SR_LSR_PARITY_ERROR)
            {
                InterlockedIncrement((PLONG)&DeviceExtension->SerialPerfStats.ParityErrorCount);
                Events |= SERIAL_EV_ERR;
            }
            if (LSR & SR_LSR_FRAMING_ERROR)
            {
                InterlockedIncrement((PLONG)&DeviceExtension->SerialPerfStats.FrameErrorCount);
                Events |= SERIAL_EV_ERR;
            }
            if (LSR & SR_LSR_BREAK_INT)
            {
                InterlockedIncrement((PLONG)&DeviceExtension->BreakInterruptErrorCount);
                Events |= SERIAL_EV_BREAK;
            }

            ret = TRUE;
            goto done;
        }
    }

done:
    if (!ret)
        return FALSE;
    if (DeviceExtension->WaitOnMaskIrp && (Events & DeviceExtension->WaitMask))
    {
        /* Finish pending IRP */
        PULONG pEvents = (PULONG)DeviceExtension->WaitOnMaskIrp->AssociatedIrp.SystemBuffer;

        DeviceExtension->WaitOnMaskIrp->IoStatus.Status = STATUS_SUCCESS;
        DeviceExtension->WaitOnMaskIrp->IoStatus.Information = sizeof(ULONG);
        *pEvents = Events;
        KeInsertQueueDpc(&DeviceExtension->CompleteIrpDpc, DeviceExtension->WaitOnMaskIrp, NULL);

        /* We are now ready to handle another IRP, even if this one is not completed */
        DeviceExtension->WaitOnMaskIrp = NULL;
        return TRUE;
    }
    return TRUE;
}