tool/mbed/mbed-sdk/libraries/net/cellular/CellularUSBModem/serial/usb/USBSerialStream.cpp

   1 /* USBSerialStream.cpp */
   2 /* Copyright (C) 2012 mbed.org, MIT License
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
   5  * and associated documentation files (the "Software"), to deal in the Software without restriction,
   6  * including without limitation the rights to use, copy, modify, merge, publish, distribute,
   7  * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
   8  * furnished to do so, subject to the following conditions:
   9  *
  10  * The above copyright notice and this permission notice shall be included in all copies or
  11  * substantial portions of the Software.
  12  *
  13  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
  14  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  15  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  16  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  17  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  18  */
  19
  20 #define __DEBUG__ 0
  21 #ifndef __MODULE__
  22 #define __MODULE__ "USBSerialStream.cpp"
  23 #endif
  24
  25 #include "core/fwk.h"
  26
  27 #include <cstring>
  28
  29 #include "USBSerialStream.h"
  30
  31
  32 USBSerialStream::USBSerialStream(IUSBHostSerial& serial) : m_serial(serial), m_serialTxFifoEmpty(true),
  33 m_availableSphre(1), m_spaceSphre(1), m_inBuf()
  34 {
  35   m_availableSphre.wait();
  36   m_spaceSphre.wait();
  37   //Attach interrupts
  38   m_serial.attach(this);
  39 }
  40
  41 /*virtual*/ USBSerialStream::~USBSerialStream()
  42 {
  43   m_serial.attach(NULL);
  44 }
  45
  46 //0 for non-blocking (returns immediately), -1 for infinite blocking
  47 /*virtual*/ int USBSerialStream::read(uint8_t* buf, size_t* pLength, size_t maxLength, uint32_t timeout/*=osWaitForever*/)
  48 {
  49   DBG("Trying to read at most %d chars", maxLength);
  50   int ret = waitAvailable(timeout);
  51   if(ret)
  52   {
  53     WARN("Error %d while waiting for incoming data", ret);
  54     return ret;
  55   }
  56   int a = available(); //Prevent macro issues
  57   int readLen = MIN( a, maxLength );
  58   *pLength = readLen;
  59
  60   setupReadableISR(false);
  61   while(readLen--)
  62   {
  63     m_inBuf.dequeue(buf);
  64     buf++;
  65   }
  66   setupReadableISR(true);
  67   DBG("Read %d chars successfully", *pLength);
  68   return OK;
  69 }
  70
  71 /*virtual*/ size_t USBSerialStream::available()
  72 {
  73   setupReadableISR(false); //m_inBuf.available() is not reentrant
  74   size_t len = m_inBuf.available();
  75   setupReadableISR(true);
  76   return len;
  77 }
  78
  79 /*virtual*/ int USBSerialStream::waitAvailable(uint32_t timeout/*=osWaitForever*/) //Wait for data to be available
  80 {
  81   int ret;
  82   if(available()) //Is data already available?
  83   {
  84     while( m_availableSphre.wait(0) > 0 ); //Clear the queue as data is available
  85     return OK;
  86   }
  87
  88   DBG("Waiting for data availability %d ms (-1 is infinite)", timeout);
  89   ret = m_availableSphre.wait(timeout); //Wait for data to arrive or for abort
  90   if(ret <= 0)
  91   {
  92     DBG("Timeout");
  93     return NET_TIMEOUT;
  94   }
  95   if(!m_inBuf.available()) //Even if abort has been called, return that data is available
  96   {
  97     DBG("Aborted");
  98     return NET_INTERRUPTED;
  99   }
 100   DBG("Finished waiting");
 101   while( m_availableSphre.wait(0) > 0 ); //Clear the queue as data is available
 102   return OK;
 103 }
 104
 105 /*virtual*/ int USBSerialStream::abortRead() //Abort current reading (or waiting) operation
 106 {
 107   if( /*!available()*/true ) //If there is data pending, no need to abort
 108   {
 109     m_availableSphre.release(); //Force exiting the waiting state
 110   }
 111   else
 112   {
 113     DBG("Serial is readable"); ;
 114   }
 115   return OK;
 116 }
 117
 118 void USBSerialStream::setupReadableISR(bool en)
 119 {
 120   m_serial.setupIrq(en, IUSBHostSerial::RxIrq);
 121 }
 122
 123 void USBSerialStream::readable() //Callback from m_serial when new data is available
 124 {
 125   while(m_serial.readable())
 126   {
 127     m_inBuf.queue(m_serial.getc());
 128   }
 129   m_serial.readPacket(); //Start read of next packet
 130   m_availableSphre.release(); //Force exiting the waiting state
 131 }
 132
 133 //0 for non-blocking (returns immediately), -1 for infinite blocking
 134 /*virtual*/ int USBSerialStream::write(uint8_t* buf, size_t length, uint32_t timeout/*=-1*/)
 135 {
 136   DBG("Trying to write %d chars", length);
 137   do
 138   {
 139     int ret = waitSpace(timeout);
 140     if(ret)
 141     {
 142       WARN("Error %d while waiting for space", ret);
 143       return ret;
 144     }
 145     int s = space(); //Prevent macro issues
 146     int writeLen = MIN( s, length );
 147     DBG("Writing %d chars", writeLen);
 148     setupWriteableISR(false);
 149     while(writeLen)
 150     {
 151       m_outBuf.queue(*buf);
 152       buf++;
 153       length--;
 154       writeLen--;
 155     }
 156     //If m_serial tx fifo is empty we need to start the packet write
 157     if( m_outBuf.available() && m_serialTxFifoEmpty )
 158     {
 159       writeable();
 160     }
 161     setupWriteableISR(true);
 162   } while(length);
 163
 164   DBG("Write successful");
 165   return OK;
 166 }
 167
 168 /*virtual*/ size_t USBSerialStream::space()
 169 {
 170   setupWriteableISR(false); //m_outBuf.available() is not reentrant
 171   size_t len = CIRCBUF_SIZE - m_outBuf.available();
 172   setupWriteableISR(true);
 173   return len;
 174 }
 175
 176 /*virtual*/ int USBSerialStream::waitSpace(uint32_t timeout/*=-1*/) //Wait for space to be available
 177 {
 178   int ret;
 179   if(space()) //Is still space already left?
 180   {
 181     while( m_spaceSphre.wait(0) > 0); //Clear the queue as space is available
 182     return OK;
 183   }
 184
 185   DBG("Waiting for data space %d ms (-1 is infinite)", timeout);
 186   ret = m_spaceSphre.wait(timeout); //Wait for space to be made or for abort
 187   if(ret <= 0)
 188   {
 189     DBG("Timeout");
 190     return NET_TIMEOUT;
 191   }
 192   if(!space()) //Even if abort has been called, return that space is available
 193   {
 194     DBG("Aborted");
 195     return NET_INTERRUPTED;
 196   }
 197   while( m_spaceSphre.wait(0) > 0); //Clear the queue as space is available
 198   return OK;
 199 }
 200
 201 /*virtual*/ int USBSerialStream::abortWrite() //Abort current writing (or waiting) operation
 202 {
 203   if( !space() ) //If there is space left, no need to abort
 204   {
 205     m_spaceSphre.release(); //Force exiting the waiting state
 206   }
 207   return OK;
 208 }
 209
 210 void USBSerialStream::setupWriteableISR(bool en)
 211 {
 212   m_serial.setupIrq(en, IUSBHostSerial::TxIrq);
 213 }
 214
 215 void USBSerialStream::writeable() //Callback from m_serial when new space is available
 216 {
 217   if(m_outBuf.isEmpty())
 218   {
 219     m_serialTxFifoEmpty = true;
 220   }
 221   else
 222   {
 223     m_serialTxFifoEmpty = false;
 224     while(m_serial.writeable() && !m_outBuf.isEmpty())
 225     {
 226       uint8_t c;
 227       m_outBuf.dequeue(&c);
 228       m_serial.putc((char)c);
 229     }
 230     m_serial.writePacket(); //Start packet write
 231   }
 232   if(!m_outBuf.isFull())
 233   {
 234     m_spaceSphre.release(); //Force exiting the waiting state
 235   }
 236 }