SourceLevelDebugPkg/Library/DebugCommunicationLibSerialPort/DebugCommunicationLibSerialPort.c

   1 /** @file
   2   Debug Port Library implementation based on serial port.
   3
   4   Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
   5   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 #include <Base.h>
  16
  17 #include <Library/DebugCommunicationLib.h>
  18 #include <Library/SerialPortLib.h>
  19 #include <Library/TimerLib.h>
  20
  21 /**
  22   Initialize the debug port.
  23
  24   This function will initialize debug port to get it ready for data transmition. If
  25   certain Debug Communication Library instance has to save some private data in the
  26   stack, this function must work on the mode that doesn't return to the caller, then
  27   the caller needs to wrap up all rest of logic after DebugPortInitialize() into one
  28   function and pass it into DebugPortInitialize(). DebugPortInitialize() is
  29   responsible to invoke the passing-in funciton at the end of DebugPortInitialize().
  30
  31   If the paramter Function is not NULL, Debug Communication Libary instance will
  32   invoke it by passing in the Context to be the first parameter. Debug Communication
  33   Library instance could create one debug port handle to be the second parameter
  34   passing into the Function. Debug Communication Library instance also could pass
  35   NULL to be the second parameter if it doesn't create the debug port handle.
  36
  37   If the parameter Function is NULL, and Context is not NULL. At this time, Context
  38   is the debug port handle created by the previous Debug Communication Library
  39   instance.
  40   a) If the instance can understand and continue use the private data of the previous
  41      instance, it could return the same handle as passed in (as Context parameter).
  42   b) If the instance does not understand, or does not want to continue use the
  43      private data of the previous instance, it could ignore the input Context parameter
  44      and create the new hanlde to be returned.
  45
  46   If Function() is NULL and Context is NULL, Debug Communication Library could create a
  47   new handle and return it. NULL is also a valid handle to be returned.
  48
  49   @param[in] Context      Context needed by callback function; it was optional.
  50   @param[in] Function     Continue function called by Debug Communication library;
  51                           it was optional.
  52
  53   @return  The debug port handle created by Debug Communication Library if Function
  54            is not NULL.
  55
  56 **/
  57 DEBUG_PORT_HANDLE
  58 EFIAPI
  59 DebugPortInitialize (
  60   IN VOID                 *Context,
  61   IN DEBUG_PORT_CONTINUE  Function
  62   )
  63 {
  64   SerialPortInitialize ();
  65
  66   if (Function != NULL) {
  67     Function (Context, NULL);
  68   }
  69
  70   return NULL;
  71 }
  72
  73 /**
  74   Read data from debug device and save the datas in buffer.
  75
  76   Reads NumberOfBytes data bytes from a debug device into the buffer
  77   specified by Buffer. The number of bytes actually read is returned.
  78   If the return value is less than NumberOfBytes, then the rest operation failed.
  79   If NumberOfBytes is zero, then return 0.
  80
  81   @param  Handle           Debug port handle.
  82   @param  Buffer           Pointer to the data buffer to store the data read from the debug device.
  83   @param  NumberOfBytes    Number of bytes which will be read.
  84   @param  Timeout          Timeout value for reading from debug device. It unit is Microsecond.
  85
  86   @retval 0                Read data failed, no data is to be read.
  87   @retval >0               Actual number of bytes read from debug device.
  88
  89 **/
  90 UINTN
  91 EFIAPI
  92 DebugPortReadBuffer (
  93   IN DEBUG_PORT_HANDLE     Handle,
  94   IN UINT8                 *Buffer,
  95   IN UINTN                 NumberOfBytes,
  96   IN UINTN                 Timeout
  97   )
  98 {
  99   UINTN                Index;
 100   INTN                 Elapsed;
 101
 102   for (Index = 0; Index < NumberOfBytes; Index ++) {
 103     Elapsed = (INTN) Timeout;
 104     while (TRUE) {
 105       if (SerialPortPoll () || Timeout == 0) {
 106         SerialPortRead (Buffer + Index, 1);
 107         break;
 108       }
 109       MicroSecondDelay (1000);
 110       Elapsed -= 1000;
 111       if (Elapsed < 0) {
 112         return 0;
 113       }
 114     }
 115   }
 116
 117   return NumberOfBytes;
 118 }
 119
 120 /**
 121   Write data from buffer to debug device.
 122
 123   Writes NumberOfBytes data bytes from Buffer to the debug device.
 124   The number of bytes actually written to the debug device is returned.
 125   If the return value is less than NumberOfBytes, then the write operation failed.
 126   If NumberOfBytes is zero, then return 0.
 127
 128   @param  Handle           Debug port handle.
 129   @param  Buffer           Pointer to the data buffer to be written.
 130   @param  NumberOfBytes    Number of bytes to written to the debug device.
 131
 132   @retval 0                NumberOfBytes is 0.
 133   @retval >0               The number of bytes written to the debug device.
 134                            If this value is less than NumberOfBytes, then the read operation failed.
 135
 136 **/
 137 UINTN
 138 EFIAPI
 139 DebugPortWriteBuffer (
 140   IN DEBUG_PORT_HANDLE     Handle,
 141   IN UINT8                 *Buffer,
 142   IN UINTN                 NumberOfBytes
 143   )
 144 {
 145   return SerialPortWrite (Buffer, NumberOfBytes);
 146 }
 147
 148 /**
 149   Polls a debug device to see if there is any data waiting to be read.
 150
 151   Polls a debug device to see if there is any data waiting to be read.
 152   If there is data waiting to be read from the debug device, then TRUE is returned.
 153   If there is no data waiting to be read from the debug device, then FALSE is returned.
 154
 155   @param  Handle           Debug port handle.
 156
 157   @retval TRUE             Data is waiting to be read from the debug device.
 158   @retval FALSE            There is no data waiting to be read from the serial device.
 159
 160 **/
 161 BOOLEAN
 162 EFIAPI
 163 DebugPortPollBuffer (
 164   IN DEBUG_PORT_HANDLE     Handle
 165   )
 166 {
 167   return SerialPortPoll ();
 168 }
 169