Diff: serial/usb/USBSerialStream.cpp

Revision:

0:8f57713b2147

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/serial/usb/USBSerialStream.cpp	Wed Sep 12 09:34:21 2012 +0000
@@ -0,0 +1,236 @@
+/* USBSerialStream.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__ "USBSerialStream.cpp"
+#endif
+
+#include "core/fwk.h"
+
+#include <stdio.h>
+
+#include "USBSerialStream.h"
+
+
+USBSerialStream::USBSerialStream(IUSBHostSerial& serial) : m_serial(serial), m_serialTxFifoEmpty(true),
+m_availableSphre(1), m_spaceSphre(1), m_inBuf()
+{
+  m_availableSphre.wait();
+  m_spaceSphre.wait();
+  //Attach interrupts
+  m_serial.attach(this);
+}
+
+/*virtual*/ USBSerialStream::~USBSerialStream()
+{
+  m_serial.attach(NULL);
+}
+
+//0 for non-blocking (returns immediately), -1 for infinite blocking
+/*virtual*/ int USBSerialStream::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 a = available(); //Prevent macro issues
+  int readLen = MIN( a, 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 USBSerialStream::available()
+{
+  setupReadableISR(false); //m_inBuf.available() is not reentrant
+  size_t len = m_inBuf.available();
+  setupReadableISR(true);
+  return len;
+}
+
+/*virtual*/ int USBSerialStream::waitAvailable(uint32_t timeout/*=osWaitForever*/) //Wait for data to be available
+{
+  int ret;
+  if(available()) //Is data already available?
+  {
+    while( m_availableSphre.wait(0) > 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(!m_inBuf.available()) //Even if abort has been called, return that data is available
+  {
+    DBG("Aborted");
+    return NET_INTERRUPTED;
+  }
+  DBG("Finished waiting");
+  while( m_availableSphre.wait(0) > 0 ); //Clear the queue as data is available
+  return OK;
+}
+
+/*virtual*/ int USBSerialStream::abortRead() //Abort current reading (or waiting) operation
+{
+  if( /*!available()*/true ) //If there is data pending, no need to abort
+  {
+    m_availableSphre.release(); //Force exiting the waiting state
+  }
+  else
+  {
+    DBG("Serial is readable"); ;
+  }
+  return OK;
+}
+
+void USBSerialStream::setupReadableISR(bool en)
+{
+  m_serial.setupIrq(en, IUSBHostSerial::RxIrq);
+}
+
+void USBSerialStream::readable() //Callback from m_serial when new data is available
+{
+  while(m_serial.readable())
+  {
+    m_inBuf.queue(m_serial.getc());
+  }
+  m_serial.readPacket(); //Start read of next packet
+  m_availableSphre.release(); //Force exiting the waiting state
+}
+
+//0 for non-blocking (returns immediately), -1 for infinite blocking
+/*virtual*/ int USBSerialStream::write(uint8_t* buf, size_t length, uint32_t timeout/*=-1*/)
+{
+  DBG("Trying to write %d chars", length);
+  do
+  {
+    int ret = waitSpace(timeout);
+    if(ret)
+    {
+      WARN("Error %d while waiting for space", ret);
+      return ret;
+    }
+    int s = space(); //Prevent macro issues
+    int writeLen = MIN( s, length );
+    DBG("Writing %d chars", writeLen);
+    setupWriteableISR(false);
+    while(writeLen)
+    {
+      m_outBuf.queue(*buf);
+      buf++;
+      length--;
+      writeLen--;
+    }
+    //If m_serial tx fifo is empty we need to start the packet write
+    if( m_outBuf.available() && m_serialTxFifoEmpty )
+    {
+      writeable();
+    }
+    setupWriteableISR(true);
+  } while(length);
+
+  DBG("Write successful");
+  return OK;
+}
+
+/*virtual*/ size_t USBSerialStream::space()
+{
+  setupWriteableISR(false); //m_outBuf.available() is not reentrant
+  size_t len = CIRCBUF_SIZE - m_outBuf.available();
+  setupWriteableISR(true);
+  return len;
+}
+
+/*virtual*/ int USBSerialStream::waitSpace(uint32_t timeout/*=-1*/) //Wait for space to be available
+{
+  int ret;
+  if(space()) //Is still space already left?
+  {
+    while( m_spaceSphre.wait(0) > 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;
+  }
+  while( m_spaceSphre.wait(0) > 0); //Clear the queue as space is available
+  return OK;
+}
+
+/*virtual*/ int USBSerialStream::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 USBSerialStream::setupWriteableISR(bool en)
+{
+  m_serial.setupIrq(en, IUSBHostSerial::TxIrq);
+}
+
+void USBSerialStream::writeable() //Callback from m_serial when new space is available
+{
+  if(m_outBuf.isEmpty())
+  {
+    m_serialTxFifoEmpty = true;
+  }
+  else
+  {
+    m_serialTxFifoEmpty = false;
+    while(m_serial.writeable() && !m_outBuf.isEmpty())
+    {
+      uint8_t c;
+      m_outBuf.dequeue(&c);
+      m_serial.putc((char)c);
+    }
+    m_serial.writePacket(); //Start packet write
+  }
+  if(!m_outBuf.isFull())
+  {
+    m_spaceSphre.release(); //Force exiting the waiting state
+  }
+}