MdePkg/Library/BaseSerialPortLibNull/BaseSerialPortLibNull.c

   1 /** @file
   2   Null Serial Port library instance with empty functions.
   3
   4   Copyright (c) 2006 - 2008, Intel Corporation
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15
  16 #include <Base.h>
  17
  18
  19 #include <Library/SerialPortLib.h>
  20
  21 /**
  22   Initialize the serial device hardware.
  23
  24   If no initialization is required, then return RETURN_SUCCESS.
  25   If the serial device was successfuly initialized, then return RETURN_SUCCESS.
  26   If the serial device could not be initialized, then return RETURN_DEVICE_ERROR.
  27
  28   @retval RETURN_SUCCESS        The serial device was initialized.
  29   @retval RETURN_DEVICE_ERROR   The serail device could not be initialized.
  30
  31 **/
  32 RETURN_STATUS
  33 EFIAPI
  34 SerialPortInitialize (
  35   VOID
  36   )
  37 {
  38   return RETURN_UNSUPPORTED;
  39 }
  40
  41 /**
  42   Write data from buffer to serial device.
  43
  44   Writes NumberOfBytes data bytes from Buffer to the serial device.
  45   The number of bytes actually written to the serial device is returned.
  46   If the return value is less than NumberOfBytes, then the write operation failed.
  47
  48   If Buffer is NULL, then ASSERT().
  49
  50   If NumberOfBytes is zero, then return 0.
  51
  52   @param  Buffer           Pointer to the data buffer to be written.
  53   @param  NumberOfBytes    Number of bytes to written to the serial device.
  54
  55   @retval 0                NumberOfBytes is 0.
  56   @retval >0               The number of bytes written to the serial device.
  57                            If this value is less than NumberOfBytes, then the read operation failed.
  58
  59 **/
  60 UINTN
  61 EFIAPI
  62 SerialPortWrite (
  63   IN UINT8     *Buffer,
  64   IN UINTN     NumberOfBytes
  65 )
  66 {
  67   return 0;
  68 }
  69
  70
  71 /**
  72   Reads data from a serial device into a buffer.
  73
  74   @param  Buffer           Pointer to the data buffer to store the data read from the serial device.
  75   @param  NumberOfBytes    Number of bytes to read from the serial device.
  76
  77   @retval 0                NumberOfBytes is 0.
  78   @retval >0               The number of bytes read from the serial device.
  79                            If this value is less than NumberOfBytes, then the read operation failed.
  80
  81 **/
  82 UINTN
  83 EFIAPI
  84 SerialPortRead (
  85   OUT UINT8     *Buffer,
  86   IN  UINTN     NumberOfBytes
  87 )
  88 {
  89   return 0;
  90 }
  91
  92 /**
  93   Polls a serial device to see if there is any data waiting to be read.
  94
  95   Polls aserial device to see if there is any data waiting to be read.
  96   If there is data waiting to be read from the serial device, then TRUE is returned.
  97   If there is no data waiting to be read from the serial device, then FALSE is returned.
  98
  99   @retval TRUE             Data is waiting to be read from the serial device.
 100   @retval FALSE            There is no data waiting to be read from the serial device.
 101
 102 **/
 103 BOOLEAN
 104 EFIAPI
 105 SerialPortPoll (
 106   VOID
 107   )
 108 {
 109   return FALSE;
 110 }
 111