File content as of revision 0:f54e9507171b:

/*
 * FreeModbus Libary: BARE Port
 * Copyright (C) 2006 Christian Walter <wolti@sil.at>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * File: $Id: portserial.c,v 1.1 2006/08/22 21:35:13 wolti Exp $
 */

/* ----------------------- System includes ----------------------------------*/
#include "mbed.h"                   // Cam

/* ----------------------- Platform includes --------------------------------*/
#include "port.h"

/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mbport.h"

DigitalOut RXLed(LED2);
DigitalOut TXLed(LED3);
Timeout RXTimeout;
Timeout TXTimeout;

void RXTimeoutFunc(void)
{
  RXLed = 0;
}

void TXTimeoutFunc(void)
{
  TXLed = 0;
}

/* ----------------------- static functions ---------------------------------*/
static void prvvUARTTxReadyISR( void );
static void prvvUARTRxISR( void );
static void prvvUARTISR( void );

/* ----------------------- System Variables ---------------------------------*/
Serial pc(USBTX, USBRX);            // Cam - mbed USB serial port

Ticker simISR;                      // Cam - mbed ticker
                                    // we don't have the TX buff empty interrupt, so
                                    // we just interrupt every 1 mSec and read RX & TX
                                    // status to simulate the proper ISRs.

static BOOL RxEnable, TxEnable;     // Cam - keep a static copy of the RxEnable and TxEnable
                                    // status for the simulated ISR (ticker)


/* ----------------------- Start implementation -----------------------------*/
// Cam - This is called every 1mS to simulate Rx character received ISR and
// Tx buffer empty ISR.
static void
prvvUARTISR( void )
{
    if (TxEnable)
    {
        if(pc.writeable())
            prvvUARTTxReadyISR();
    }        
    if (RxEnable)
    {
        if(pc.readable())
            prvvUARTRxISR();          
    }
}

void
vMBPortSerialEnable( BOOL xRxEnable, BOOL xTxEnable )
{
    /* If xRXEnable enable serial receive interrupts. If xTxENable enable
     * transmitter empty interrupts.
     */
    RxEnable = xRxEnable;
    TxEnable = xTxEnable;
}

BOOL
xMBPortSerialInit( UCHAR ucPORT, ULONG ulBaudRate, UCHAR ucDataBits, eMBParity eParity )
{
    simISR.attach_us(&prvvUARTISR,1000);    // Cam - attach prvvUARTISR to a 1mS ticker to simulate serial interrupt behaviour
                                            // 1mS is just short of a character time at 9600 bps, so quick enough to pick
                                            // up status on a character by character basis.
    return TRUE;
}

BOOL
xMBPortSerialPutByte( CHAR ucByte )
{
    /* Put a byte in the UARTs transmit buffer. This function is called
     * by the protocol stack if pxMBFrameCBTransmitterEmpty( ) has been
     * called. */
    pc.putc( ucByte);
    TXLed = 1;
    TXTimeout.attach(TXTimeoutFunc, 0.020);
    return TRUE;
}

BOOL
xMBPortSerialGetByte( CHAR * pucByte )
{
    /* Return the byte in the UARTs receive buffer. This function is called
     * by the protocol stack after pxMBFrameCBByteReceived( ) has been called.
     */
    * pucByte = pc.getc();
    RXLed = 1;
    RXTimeout.attach(RXTimeoutFunc, 0.020);
    return TRUE;
}

/* Create an interrupt handler for the transmit buffer empty interrupt
 * (or an equivalent) for your target processor. This function should then
 * call pxMBFrameCBTransmitterEmpty( ) which tells the protocol stack that
 * a new character can be sent. The protocol stack will then call 
 * xMBPortSerialPutByte( ) to send the character.
 */
static void prvvUARTTxReadyISR( void )
{
    pxMBFrameCBTransmitterEmpty(  );
}

/* Create an interrupt handler for the receive interrupt for your target
 * processor. This function should then call pxMBFrameCBByteReceived( ). The
 * protocol stack will then call xMBPortSerialGetByte( ) to retrieve the
 * character.
 */
static void prvvUARTRxISR( void )
{
    pxMBFrameCBByteReceived(  );
}