readwrite.c

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/*
 * PROJECT:     ReactOS i8042 (ps/2 keyboard-mouse controller) driver
 * LICENSE:     GPL - See COPYING in the top level directory
 * FILE:        drivers/input/i8042prt/readwrite.c
 * PURPOSE:     Read/write port functions
 * PROGRAMMERS: Copyright Victor Kirhenshtein (sauros@iname.com)
                Copyright Jason Filby (jasonfilby@yahoo.com)
                Copyright Martijn Vernooij (o112w8r02@sneakemail.com)
                Copyright 2006-2007 Hervé Poussineau (hpoussin@reactos.org)
 */

/* INCLUDES ******************************************************************/

#include "i8042prt.h"

#include <debug.h>

/* FUNCTIONS *****************************************************************/

VOID
i8042Flush(
    IN PPORT_DEVICE_EXTENSION DeviceExtension)
{
    UCHAR Ignore;

    /* Flush output buffer */
    while (NT_SUCCESS(i8042ReadData(DeviceExtension, KBD_OBF /* | MOU_OBF*/, &Ignore))) {
        KeStallExecutionProcessor(50);
        TRACE_(I8042PRT, "Output data flushed\n");
    }

    /* Flush input buffer */
    while (NT_SUCCESS(i8042ReadData(DeviceExtension, KBD_IBF, &Ignore))) {
        KeStallExecutionProcessor(50);
        TRACE_(I8042PRT, "Input data flushed\n");
    }
}

BOOLEAN
i8042IsrWritePort(
    IN PPORT_DEVICE_EXTENSION DeviceExtension,
    IN UCHAR Value,
    IN UCHAR SelectCmd OPTIONAL)
{
    if (SelectCmd)
        if (!i8042Write(DeviceExtension, DeviceExtension->ControlPort, SelectCmd))
            return FALSE;

    return i8042Write(DeviceExtension, DeviceExtension->DataPort, Value);
}

/*
 * FUNCTION: Read data from port 0x60
 */
NTSTATUS
i8042ReadData(
    IN PPORT_DEVICE_EXTENSION DeviceExtension,
    IN UCHAR StatusFlags,
    OUT PUCHAR Data)
{
    UCHAR PortStatus;
    NTSTATUS Status;

    Status = i8042ReadStatus(DeviceExtension, &PortStatus);
    if (!NT_SUCCESS(Status))
        return Status;

    // If data is available
    if (PortStatus & StatusFlags)
    {
        *Data = READ_PORT_UCHAR(DeviceExtension->DataPort);
        INFO_(I8042PRT, "Read: 0x%02x (status: 0x%x)\n", Data[0], PortStatus);

        // If the data is valid (not timeout, not parity error)
        if ((PortStatus & KBD_PERR) == 0)
            return STATUS_SUCCESS;
    }
    return STATUS_UNSUCCESSFUL;
}

NTSTATUS
i8042ReadStatus(
    IN PPORT_DEVICE_EXTENSION DeviceExtension,
    OUT PUCHAR Status)
{
    ASSERT(DeviceExtension->ControlPort != NULL);
    *Status = READ_PORT_UCHAR(DeviceExtension->ControlPort);
    return STATUS_SUCCESS;
}

/*
 * FUNCTION: Read data from data port
 */
NTSTATUS
i8042ReadDataWait(
    IN PPORT_DEVICE_EXTENSION DeviceExtension,
    OUT PUCHAR Data)
{
    ULONG Counter;
    NTSTATUS Status;

    Counter = DeviceExtension->Settings.PollingIterations;

    while (Counter--)
    {
        Status = i8042ReadKeyboardData(DeviceExtension, Data);

        if (NT_SUCCESS(Status))
            return Status;

        KeStallExecutionProcessor(50);
    }

    /* Timed out */
    return STATUS_IO_TIMEOUT;
}

/*
 * This one reads a value from the port; You don't have to specify
 * which one, it'll always be from the one you talked to, so one function
 * is enough this time. Note how MSDN specifies the
 * WaitForAck parameter to be ignored.
 */
NTSTATUS NTAPI
i8042SynchReadPort(
    IN PVOID Context,
    OUT PUCHAR Value,
    IN BOOLEAN WaitForAck)
{
    PPORT_DEVICE_EXTENSION DeviceExtension;

    UNREFERENCED_PARAMETER(WaitForAck);

    DeviceExtension = (PPORT_DEVICE_EXTENSION)Context;

    return i8042ReadDataWait(DeviceExtension, Value);
}

/*
 * These functions are callbacks for filter driver custom
 * initialization routines.
 */
NTSTATUS NTAPI
i8042SynchWritePort(
    IN PPORT_DEVICE_EXTENSION DeviceExtension,
    IN UCHAR Port,
    IN UCHAR Value,
    IN BOOLEAN WaitForAck)
{
    NTSTATUS Status;
    UCHAR Ack;
    ULONG ResendIterations;

    ResendIterations = DeviceExtension->Settings.ResendIterations + 1;

    do
    {
        if (Port)
            if (!i8042Write(DeviceExtension, DeviceExtension->DataPort, Port))
            {
                WARN_(I8042PRT, "Failed to write Port\n");
                return STATUS_IO_TIMEOUT;
            }

        if (!i8042Write(DeviceExtension, DeviceExtension->DataPort, Value))
        {
            WARN_(I8042PRT, "Failed to write Value\n");
            return STATUS_IO_TIMEOUT;
        }

        if (WaitForAck)
        {
            Status = i8042ReadDataWait(DeviceExtension, &Ack);
            if (!NT_SUCCESS(Status))
            {
                WARN_(I8042PRT, "Failed to read Ack\n");
                return Status;
            }
            if (Ack == KBD_ACK)
                return STATUS_SUCCESS;
            else if (Ack == KBD_RESEND)
                INFO_(I8042PRT, "i8042 asks for a data resend\n");
        }
        else
        {
            return STATUS_SUCCESS;
        }
        TRACE_(I8042PRT, "Reiterating\n");
        ResendIterations--;
    } while (ResendIterations);

    return STATUS_IO_TIMEOUT;
}

/*
 * FUNCTION: Write data to a port, waiting first for it to become ready
 */
BOOLEAN
i8042Write(
    IN PPORT_DEVICE_EXTENSION DeviceExtension,
    IN PUCHAR addr,
    IN UCHAR data)
{
    ULONG Counter;

    ASSERT(addr);
    ASSERT(DeviceExtension->ControlPort != NULL);

    Counter = DeviceExtension->Settings.PollingIterations;

    while ((KBD_IBF & READ_PORT_UCHAR(DeviceExtension->ControlPort)) &&
           (Counter--))
    {
        KeStallExecutionProcessor(50);
    }

    if (Counter)
    {
        WRITE_PORT_UCHAR(addr, data);
        INFO_(I8042PRT, "Sent 0x%x to port %p\n", data, addr);
        return TRUE;
    }
    return FALSE;
}