File content as of revision 10:21a6f09d5631:

/* IOSerialStream.cpp */
/*
Copyright (C) 2012 ARM Limited.

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#define __DEBUG__ 0 //Maximum verbosity
#ifndef __MODULE__
#define __MODULE__ "IOSerialStream.cpp"
#endif

#include "core/fwk.h"

#include <stdio.h>

#include "IOSerialStream.h"

IOSerialStream::IOSerialStream(mbed::Serial& serial) : m_serial(serial), m_serialTxFifoEmpty(true),
m_availableSphre(1), m_spaceSphre(1), m_inBuf(), m_outBuf()
{
  m_availableSphre.wait();
  m_spaceSphre.wait();
  //Attach interrupts
  m_serial.attach(this, &IOSerialStream::readable, mbed::Serial::RxIrq);
  m_serial.attach(this, &IOSerialStream::writeable, mbed::Serial::TxIrq);
}

/*virtual*/ IOSerialStream::~IOSerialStream()
{
  m_serial.attach(NULL, mbed::Serial::RxIrq);
  m_serial.attach(NULL, mbed::Serial::TxIrq);
}

//0 for non-blocking (returns immediately), osWaitForever for infinite blocking
/*virtual*/ int IOSerialStream::read(uint8_t* buf, size_t* pLength, size_t maxLength, uint32_t timeout/*=osWaitForever*/)
{
  DBG("Trying to read at most %d chars", maxLength);
  int ret = waitAvailable(timeout);
  if(ret)
  {
    WARN("Error %d while waiting for incoming data", ret);
    return ret;
  }
  int readLen = MIN( available(), maxLength );
  *pLength = readLen;
  setupReadableISR(false);
  while(readLen--)
  {
    m_inBuf.dequeue(buf);
    buf++;
  }
  setupReadableISR(true);
  DBG("Read %d chars successfully", *pLength);
  return OK;
}

/*virtual*/ size_t IOSerialStream::available()
{
  setupReadableISR(false); //m_inBuf.available() is not reentrant
  size_t len = m_inBuf.available();
  setupReadableISR(true);
  return len;
}

/*virtual*/ int IOSerialStream::waitAvailable(uint32_t timeout/*=osWaitForever*/) //Wait for data to be available
{
  int ret;
  if(available()) //Is data already available?
  {
    m_availableSphre.wait(0); //Clear the queue as data is available
    return OK;
  }

  DBG("Waiting for data availability %d ms (-1 is infinite)", timeout);
  ret = m_availableSphre.wait(timeout); //Wait for data to arrive or for abort
  if(ret <= 0)
  {
    DBG("Timeout");
    return NET_TIMEOUT;
  }
  if(!available()) //Even if abort has been called, return that data is available
  {
    DBG("Aborted");
    return NET_INTERRUPTED;
  }
  DBG("Finished waiting");
  m_availableSphre.wait(0); //Clear the queue as data is available
  return OK;
}

/*virtual*/ int IOSerialStream::abortRead() //Abort current reading (or waiting) operation
{
  if( !available() ) //If there is data pending, no need to abort
  {
    m_availableSphre.release(); //Force exiting the waiting state; kludge to pass a RC directly
  }
  else
  {
    DBG("Serial is readable"); ;
  }
  return OK;
}

void IOSerialStream::setupReadableISR(bool en)
{
  if(en)
  {
    ((LPC_UART_TypeDef *)(UART_3))->IER |= 1 << 0;
  }
  else
  {
    ((LPC_UART_TypeDef *)(UART_3))->IER &= ~(1 << 0);
  }
}

void IOSerialStream::readable() //Callback from m_serial when new data is available
{
  do
  {
    m_inBuf.queue(((LPC_UART_TypeDef *)UART_3)->RBR); //FIXME mbed libraries this is an awful kludge
  } while(m_serial.readable());
  m_availableSphre.release(); //Force exiting the waiting state
}

//0 for non-blocking (returns immediately), osWaitForever for infinite blocking
/*virtual*/ int IOSerialStream::write(uint8_t* buf, size_t length, uint32_t timeout/*=osWaitForever*/)
{
  DBG("Trying to write %d chars", length);
  int ret = waitSpace(timeout);
  if(ret)
  {
    WARN("Error %d while waiting for space", ret);
    return ret;
  }
  DBG("Writing %d chars", length);
  setupWriteableISR(false);
  while(length)
  {
    m_outBuf.queue(*buf);
    buf++;
    length--;
    if(length && !space())
    {
      DBG("Waiting to write remaining %d chars", length);
      setupWriteableISR(true);
      ret = waitSpace(timeout);
      if(ret)
      {
        WARN("Error %d while waiting for space", ret);
        return ret;
      }
      setupWriteableISR(false);
    }
  }
  //If m_serial tx fifo is empty we need to manually tx a byte in order to trigger the interrupt
  if( m_outBuf.available() && m_serialTxFifoEmpty )
  {
    m_serialTxFifoEmpty = false;
    uint8_t c;
    m_outBuf.dequeue(&c);
    //m_serial.putc((char)c);
    ((LPC_UART_TypeDef *)UART_3)->THR = c; //FIXME awful kludge
  }
  setupWriteableISR(true);
  DBG("Write successful");
  return OK;
}

/*virtual*/ size_t IOSerialStream::space()
{
  setupWriteableISR(false); //m_outBuf.available() is not reentrant
  size_t len = CIRCBUF_SIZE - m_outBuf.available();
  setupWriteableISR(true);
  return len;
}

/*virtual*/ int IOSerialStream::waitSpace(uint32_t timeout/*=osWaitForever*/) //Wait for space to be available
{
  int ret;
  if(space()) //Is still space already left?
  {
    m_spaceSphre.wait(0); //Clear the queue as space is available
    return OK;
  }

  DBG("Waiting for data space %d ms (-1 is infinite)", timeout);
  ret = m_spaceSphre.wait(timeout); //Wait for space to be made or for abort
  if(ret <= 0)
  {
    DBG("Timeout");
    return NET_TIMEOUT;
  }
  if(!space()) //Even if abort has been called, return that space is available
  {
    DBG("Aborted");
    return NET_INTERRUPTED;
  }
  m_spaceSphre.wait(0); //Clear the queue as space is available
  return OK;
}

/*virtual*/ int IOSerialStream::abortWrite() //Abort current writing (or waiting) operation
{
  if( !space() ) //If there is space left, no need to abort
  {
    m_spaceSphre.release(); //Force exiting the waiting state
  }
  return OK;
}

void IOSerialStream::setupWriteableISR(bool en)
{
  if(en)
  {
    ((LPC_UART_TypeDef *)(UART_3))->IER |= 1 << 1;
  }
  else
  {
    ((LPC_UART_TypeDef *)(UART_3))->IER &= ~(1 << 1);
  }
}

void IOSerialStream::writeable() //Callback from m_serial when new space is available
{
  if(m_outBuf.isEmpty())
  {
    m_serialTxFifoEmpty = true;
  }
  else
  {
    while(m_serial.writeable() && !m_outBuf.isEmpty())
    {
      uint8_t c;
      m_outBuf.dequeue(&c);
      //m_serial.putc((char)c);
      ((LPC_UART_TypeDef *)UART_3)->THR = c; //FIXME awful kludge
    }
  }
  m_spaceSphre.release(); //Force exiting the waiting state
}