/*++

Copyright (c) Microsoft Corporation.  All rights reserved.

Module Name:

    apm88xxxx.c

Abstract:

    This module contains support for the Applied Micro 88xxxx UART.
    It differs from the standard 16550 in these ways:
     * clock - base clock is 50MHz / 16
     * register alignment - registers are aligned on 32 bit boundaries

--*/

// ------------------------------------------------------------------- Includes

#include "common.h"

// ---------------------------------------------------------------- Definitions

#define CLOCK_RATE 3125000UL

// ----------------------------------------------------------------- Prototypes

BOOLEAN
Uart16550InitializePortCommon (
    _In_opt_ _Null_terminated_ PCHAR LoadOptions,
    _Inout_ PCPPORT Port,
    BOOLEAN MemoryMapped,
    UCHAR AccessSize,
    UCHAR BitWidth
    );

BOOLEAN
Uart16550SetBaudCommon (
    _Inout_ PCPPORT Port,
    ULONG Rate,
    ULONG Clock
    );

UART_STATUS
Uart16550GetByte (
    _Inout_ PCPPORT Port,
    _Out_ PUCHAR Byte
    );

UART_STATUS
Uart16550PutByte (
    _Inout_ PCPPORT Port,
    UCHAR Byte,
    BOOLEAN BusyWait
    );

BOOLEAN
Uart16550RxReady (
    _Inout_ PCPPORT Port
    );

// ------------------------------------------------------------------ Functions

BOOLEAN
Apm88xxxxInitializePort (
    _In_opt_ _Null_terminated_ PCHAR LoadOptions,
    _Inout_ PCPPORT Port,
    BOOLEAN MemoryMapped,
    UCHAR AccessSize,
    UCHAR BitWidth
    )

/*++

Routine Description:

    This routine performs the initialization of an APM88xxxx serial UART.

Arguments:

    LoadOptions - Optional load option string.

    Port - Supplies a pointer to a CPPORT object which will be filled in as
        part of the port initialization.

    MemoryMapped - Supplies a boolean which indicates if the UART is accessed
        through memory-mapped registers or legacy port I/O.

    AccessSize - Unused.

    BitWidth - Unused.

Return Value:

    TRUE if the port has been successfully initialized, FALSE otherwise.

--*/

{

    UNREFERENCED_PARAMETER(AccessSize);
    UNREFERENCED_PARAMETER(BitWidth);

    Port->Flags = 0;
    return Uart16550InitializePortCommon(LoadOptions,
                                         Port,
                                         MemoryMapped,
                                         AcpiGenericAccessSizeByte,
                                         32);
}

BOOLEAN
Apm88xxxxSetBaud (
    _Inout_ PCPPORT Port,
    ULONG Rate
    )

/*++

Routine Description:

    Set the baud rate for the UART hardware and record it in the port object.

Arguments:

    Port - Supplies the address of the port object that describes the UART.

    Rate - Supplies the desired baud rate in bits per second.

Return Value:

    TRUE if the baud rate was programmed, FALSE if it was not.

--*/

{

    if (CHECK_FLAG(Port->Flags, PORT_DEFAULT_RATE)) {
        return FALSE;
    }

    //
    // N.B. The CLOCK_RATE defined in this file is different from the one
    // used by Uart16550SetBaud.
    //

    return Uart16550SetBaudCommon(Port, Rate, CLOCK_RATE);
}

// -------------------------------------------------------------------- Globals

UART_HARDWARE_DRIVER Apm88xxxxHardwareDriver = {
    Apm88xxxxInitializePort,
    Apm88xxxxSetBaud,
    Uart16550GetByte,
    Uart16550PutByte,
    Uart16550RxReady,
    NULL,
    NULL
};