audk/MdePkg/Include/Library/SerialPortLib.h

/** @file
  Serial I/O Port library functions definition.

  Copyright (c) 2006 - 2008, Intel Corporation
  All rights reserved. This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#ifndef __SERIAL_PORT_LIB__
#define __SERIAL_PORT_LIB__

/**

  Programmed hardware of Serial port.

  @return  Status of Serial Port Device initialization.

**/
RETURN_STATUS
EFIAPI
SerialPortInitialize (
  VOID
  );

/**
  Write data from buffer to serial device. 
 
  If the Buffer is NULL, then return 0; 
  if NumberOfBytes is zero, then return 0. 

  @param  Buffer           Point of data buffer which need to be writed.
  @param  NumberOfBytes    Number of output bytes which are cached in Buffer.

  @retval 0                Write data failed, or No data is to be written.
  @retval !0               Actual number of bytes writed to serial device.

**/
UINTN
EFIAPI
SerialPortWrite (
  IN UINT8 	   *Buffer,
  IN UINTN 	   NumberOfBytes
  );


/**
  Read data from serial device and save the datas in buffer.
 
  If the Buffer is NULL, then return zero;
  if NumberOfBytes is zero, then return zero.

  @param  Buffer           Point of data buffer, which contains the data 
                           returned from the serial device.
  @param  NumberOfBytes    Number of bytes which will be read.

  @retval 0                Read data failed, No data is to be read.
  @retval !0               Aactual number of bytes read from serial device.

**/
UINTN
EFIAPI
SerialPortRead (
  OUT UINT8 	*Buffer,
  IN  UINTN 	NumberOfBytes
  );

/**
  Poll the serial device to see if there is any data waiting.

  If there is data waiting to be read from the serial port, then return
  TRUE.  If there is no data waiting to be read from the serial port, then 
  return FALSE.

  @retval TRUE             Data is waiting to be read.
  @retval FALSE            There is no data waiting to be read.

**/
BOOLEAN
EFIAPI
SerialPortPoll (
  VOID
  );

#endif