FreeModbus: AT91SAM7X

/*
 * FreeModbus Libary: ARM7 Demo Application
 * Copyright (C) 2006 Christian Walter <wolti@sil.at>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * File: $Id$
 */

/* ----------------------- System includes ----------------------------------*/
#include "assert.h"

/* ----------------------- Platform includes --------------------------------*/
#include "support/AT91SAM7X256.h"
#include "support/lib_AT91SAM7X256.h"

#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"

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

/* ----------------------- Defines ------------------------------------------*/
#define REG_HOLDING_START           0x1000
#define REG_HOLDING_NREGS           130
#define REG_INPUT_START             0x1000
#define REG_INPUT_NREGS             4

/* ----------------------- Static variables ---------------------------------*/
static USHORT   usRegHoldingStart = REG_HOLDING_START;
static USHORT   usRegHoldingBuf[REG_HOLDING_NREGS];
static USHORT   usRegInputStart = REG_INPUT_START;
static USHORT   usRegInputBuf[REG_INPUT_NREGS];

/* ----------------------- Static functions ---------------------------------*/
STATIC void     vModbusTask( void *pvParameters );
STATIC void     vSetupHardware( void );

/* ----------------------- Start implementation -----------------------------*/
int
main( void )
{
    vSetupHardware(  );

    ( void )xTaskCreate( vModbusTask, NULL, configMINIMAL_STACK_SIZE, NULL,
                         tskIDLE_PRIORITY, NULL );

    vTaskStartScheduler(  );
    return 0;
}

static void
vModbusTask( void *pvParameters )
{
    int             i;

    /* Select either ASCII or RTU Mode. */
    ( void )eMBInit( MB_RTU, 0x0A, 0, 38400, MB_PAR_EVEN );

    /* Initialize the holding register values before starting the
     * Modbus stack
     */
    for( i = 0; i < REG_HOLDING_NREGS; i++ )
    {
        usRegHoldingBuf[i] = ( unsigned short )i;
    }
    /* Initialize the input register values before starting the
     * Modbus stack
     */
    for( i = 0; i < REG_INPUT_NREGS; i++ )
    {
        usRegInputBuf[i] = ( unsigned short )i;
    }

    /* Enable the Modbus Protocol Stack. */
    ( void )eMBEnable(  );
    for( ;; )
    {
        /* Call the main polling loop of the Modbus protocol stack. */
        ( void )eMBPoll(  );
    }
}

eMBErrorCode
eMBRegInputCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs )
{
    eMBErrorCode    eStatus = MB_ENOERR;
    int             iRegIndex;

    if( ( usAddress >= REG_INPUT_START )
        && ( usAddress + usNRegs <= REG_INPUT_START + REG_INPUT_NREGS ) )
    {
        iRegIndex = ( int )( usAddress - usRegInputStart );
        while( usNRegs > 0 )
        {
            *pucRegBuffer++ = ( unsigned char )( usRegInputBuf[iRegIndex] >> 8 );
            *pucRegBuffer++ = ( unsigned char )( usRegInputBuf[iRegIndex] & 0xFF );
            iRegIndex++;
            usNRegs--;
        }
    }
    else
    {
        eStatus = MB_ENOREG;
    }

    return eStatus;
}

eMBErrorCode
eMBRegHoldingCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNRegs, eMBRegisterMode eMode )
{
    eMBErrorCode    eStatus = MB_ENOERR;
    int             iRegIndex;

    if( ( usAddress >= REG_HOLDING_START ) &&
        ( usAddress + usNRegs <= REG_HOLDING_START + REG_HOLDING_NREGS ) )
    {
        iRegIndex = ( int )( usAddress - usRegHoldingStart );
        switch ( eMode )
        {
            /* Pass current register values to the protocol stack. */
        case MB_REG_READ:
            while( usNRegs > 0 )
            {
                *pucRegBuffer++ = ( unsigned char )( usRegHoldingBuf[iRegIndex] >> 8 );
                *pucRegBuffer++ = ( unsigned char )( usRegHoldingBuf[iRegIndex] & 0xFF );
                iRegIndex++;
                usNRegs--;
            }
            break;

            /* Update current register values with new values from the
             * protocol stack. */
        case MB_REG_WRITE:
            while( usNRegs > 0 )
            {
                usRegHoldingBuf[iRegIndex] = *pucRegBuffer++ << 8;
                usRegHoldingBuf[iRegIndex] |= *pucRegBuffer++;
                iRegIndex++;
                usNRegs--;
            }
        }
    }
    else
    {
        eStatus = MB_ENOREG;
    }
    return eStatus;
}


eMBErrorCode
eMBRegCoilsCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNCoils, eMBRegisterMode eMode )
{
    return MB_ENOREG;
}

eMBErrorCode
eMBRegDiscreteCB( UCHAR * pucRegBuffer, USHORT usAddress, USHORT usNDiscrete )
{
    return MB_ENOREG;
}


void
vSetupHardware( void )
{
    vMBPInit(  );

    /* Enable the peripheral clock. */
    AT91C_BASE_PMC->PMC_PCER = 1 << AT91C_ID_PIOA;
    AT91C_BASE_PMC->PMC_PCER = 1 << AT91C_ID_PIOB;
}
AT91SAM7X_ROWLEY/demo.c
