/* 
 * FreeModbus Libary: A portable Modbus implementation for Modbus ASCII/RTU.
 * Copyright (C) 2013 Armink <armink.ztl@gmail.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * File: $Id: mbfuncinput_m.c,v 1.60 2013/10/12 14:23:40 Armink Add Master Functions  Exp $
 */

/* ----------------------- System includes ----------------------------------*/
#include "stdlib.h"
#include "string.h"

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

/* ----------------------- Modbus includes ----------------------------------*/
#include "mb.h"
#include "mb_m.h"
#include "mbframe.h"
#include "mbproto.h"
#include "mbconfig.h"

/* ----------------------- Defines ------------------------------------------*/
#define MB_PDU_REQ_READ_ADDR_OFF            ( MB_PDU_DATA_OFF + 0 )
#define MB_PDU_REQ_READ_REGCNT_OFF          ( MB_PDU_DATA_OFF + 2 )
#define MB_PDU_REQ_READ_SIZE                ( 4 )
#define MB_PDU_FUNC_READ_BYTECNT_OFF        ( MB_PDU_DATA_OFF + 0 )
#define MB_PDU_FUNC_READ_VALUES_OFF         ( MB_PDU_DATA_OFF + 1 )
#define MB_PDU_FUNC_READ_SIZE_MIN           ( 1 )

#define MB_PDU_FUNC_READ_RSP_BYTECNT_OFF    ( MB_PDU_DATA_OFF )

/* ----------------------- Static functions ---------------------------------*/
eMBException    prveMBError2Exception( eMBErrorCode eErrorCode );

/* ----------------------- Start implementation -----------------------------*/
#if MB_MASTER_RTU_ENABLED > 0 || MB_MASTER_ASCII_ENABLED > 0
#if MB_FUNC_READ_INPUT_ENABLED > 0

eMBMasterReqErrCode
eMBMasterReqReadInputRegister( UCHAR ucSndAddr, USHORT usRegAddr, USHORT usNRegs )
{
    UCHAR                 *ucMBFrame;
    eMBMasterReqErrCode    eErrStatus = MB_MRE_NO_ERR;

    if ( xMBMasterGetIsBusy() ) eErrStatus = MB_MRE_MASTER_BUSY;
    else if ( ucSndAddr > MB_MASTER_TOTAL_SLAVE_NUM ) eErrStatus = MB_MRE_ILL_ARG;
    else
    {
		vMBMasterGetPDUSndBuf(&ucMBFrame);
		vMBMasterSetDestAddress(ucSndAddr);
		ucMBFrame[MB_PDU_FUNC_OFF]                = MB_FUNC_READ_INPUT_REGISTER;
		ucMBFrame[MB_PDU_REQ_READ_ADDR_OFF]       = usRegAddr >> 8;
		ucMBFrame[MB_PDU_REQ_READ_ADDR_OFF + 1]   = usRegAddr;
		ucMBFrame[MB_PDU_REQ_READ_REGCNT_OFF]     = usNRegs >> 8;
		ucMBFrame[MB_PDU_REQ_READ_REGCNT_OFF + 1] = usNRegs;
		vMBMasterSetPDUSndLength( MB_PDU_SIZE_MIN + MB_PDU_REQ_READ_SIZE );
		( void ) xMBMasterPortEventPost( EV_MASTER_FRAME_SENT );
    }
    return eErrStatus;
}

eMBException
eMBMasterFuncReadInputRegister( UCHAR * pucFrame, USHORT * usLen )
{
    UCHAR          *ucMBFrame;
    USHORT          usRegAddress;
    USHORT          usRegCount;

    eMBException    eStatus = MB_EX_NONE;
    eMBErrorCode    eRegStatus;

    if( *usLen >= MB_PDU_SIZE_MIN + MB_PDU_FUNC_READ_SIZE_MIN)
    {
		vMBMasterGetPDUSndBuf(&ucMBFrame);
        usRegAddress = ( USHORT )( ucMBFrame[MB_PDU_REQ_READ_ADDR_OFF] << 8 );
        usRegAddress |= ( USHORT )( ucMBFrame[MB_PDU_REQ_READ_ADDR_OFF + 1] );
        usRegAddress++;

        usRegCount = ( USHORT )( ucMBFrame[MB_PDU_REQ_READ_REGCNT_OFF] << 8 );
        usRegCount = ( USHORT )( ucMBFrame[MB_PDU_REQ_READ_REGCNT_OFF + 1] );

        /* Check if the number of registers to read is valid. If not
         * return Modbus illegal data value exception.
         */
        if( ( usRegCount >= 1 ) && ( 2 * usRegCount == pucFrame[MB_PDU_FUNC_READ_BYTECNT_OFF] ) )
        {
            /* Make callback to fill the buffer. */
            eRegStatus = eMBRegInputCB( &pucFrame[MB_PDU_FUNC_READ_VALUES_OFF], usRegAddress, usRegCount );
            /* If an error occured convert it into a Modbus exception. */
            if( eRegStatus != MB_ENOERR )
            {
                eStatus = prveMBError2Exception( eRegStatus );
            }
        }
        else
        {
            eStatus = MB_EX_ILLEGAL_DATA_VALUE;
        }
    }
    else
    {
        /* Can't be a valid request because the length is incorrect. */
        eStatus = MB_EX_ILLEGAL_DATA_VALUE;
    }
    return eStatus;
}

#endif
#endif