Diff: serial/io/IOSerialStream.cpp

Revision:

3:be33ff78d8c7

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/serial/io/IOSerialStream.cpp	Mon Dec 16 09:00:30 2013 +0000
@@ -0,0 +1,253 @@
+/* IOSerialStream.cpp */
+/* Copyright (C) 2012 mbed.org, MIT License
+ *
+ * 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 <cstring>
+
+#include "IOSerialStream.h"
+
+#define UART_X ((LPC_UART_TypeDef *)(UART_1))
+
+IOSerialStream::IOSerialStream(mbed::RawSerial& 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::SerialBase::RxIrq);
+  m_serial.attach(this, &IOSerialStream::writeable, mbed::SerialBase::TxIrq);
+}
+
+/*virtual*/ IOSerialStream::~IOSerialStream()
+{
+  m_serial.attach(NULL, mbed::SerialBase::RxIrq);
+  m_serial.attach(NULL, mbed::SerialBase::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)
+  {
+    UART_X->IER |= 1 << 0;
+  }
+  else
+  {
+    UART_X->IER &= ~(1 << 0);
+  }
+}
+
+void IOSerialStream::readable() //Callback from m_serial when new data is available
+{
+  do
+  {
+    m_inBuf.queue(m_serial.getc());
+  } 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);
+  }
+  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)
+  {
+    UART_X->IER |= 1 << 1;
+  }
+  else
+  {
+    UART_X->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);
+    }
+  }
+  m_spaceSphre.release(); //Force exiting the waiting state
+}