master.h

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/*
    liblightmodbus - a lightweight, multiplatform Modbus library
    Copyright (C) 2017 Jacek Wieczorek <mrjjot@gmail.com>

    This file is part of liblightmodbus.

    Liblightmodbus 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 3 of the License, or
    (at your option) any later version.

    Liblightmodbus 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, see <http://www.gnu.org/licenses/>.
*/

#ifndef LIGHTMODBUS_MASTER_H
#define LIGHTMODBUS_MASTER_H

// For C++
#ifdef __cplusplus
extern "C" {
#endif

#include <inttypes.h>
#include "parser.h"
#include "libconf.h"
#include "lightmodbus.h"

#ifdef LIGHTMODBUS_MASTER_BASE

#if defined( LIGHTMODBUS_MASTER_INVASIVE_PARSING ) && !defined( LIGHTMODBUS_NO_MASTER_DATA_BUFFER )
    #warning LIGHTMODBUS_MASTER_INVASIVE_PARSING has no effect if LIGHTMODBUS_NO_MASTER_DATA_BUFFER is not defined
#endif

#if defined( LIGHTMODBUS_NO_MASTER_DATA_BUFFER ) && !defined( LIGHTMODBUS_EXPERIMENTAL )
    #error Disabling exclusive master data buffer is an experimental feature that may cause problems. Please define LIGHTMODBUS_EXPERIMENTAL to dismiss this error message, but please make sure your system permits unaligned memory acces beforehand.
#endif

#if defined( LIGHTMODBUS_NO_MASTER_DATA_BUFFER ) && defined( LIGHTMODBUS_STATIC_MEM_MASTER_DATA )
    #error LIGHTMODBUS_STATIC_MEM_MASTER_DATA and LIGHTMODBUS_NO_MASTER_DATA_BUFFER cannot be used at once. Please make up your mind.
#endif

#ifdef LIGHTMODBUS_MASTER_USER_FUNCTIONS
    struct modbusMaster;

    typedef struct modbusMasterUserFunction
    {
        uint8_t function; 
        ModbusError ( *handler )( struct modbusMaster *status, ModbusParser *parser, ModbusParser *requestParser ); 
    } ModbusMasterUserFunction;
#endif

typedef struct modbusMaster
{
    uint8_t predictedResponseLength;

    struct
    {
        #ifdef LIGHTMODBUS_STATIC_MEM_MASTER_REQUEST
            uint8_t frame[LIGHTMODBUS_STATIC_MEM_MASTER_REQUEST];
        #else
            uint8_t *frame;
        #endif

        uint8_t length;
    } request;

    struct //Response from slave should be put here
    {
        #ifdef LIGHTMODBUS_STATIC_MEM_MASTER_RESPONSE
            uint8_t frame[LIGHTMODBUS_STATIC_MEM_MASTER_RESPONSE];
        #else
            const uint8_t *frame;
        #endif

        uint8_t length;
    } response;

    struct
    {
        uint8_t address; 
        uint16_t index; 
        uint16_t count; 
        uint8_t length; 
        ModbusDataType type; 
        uint8_t function; 

        #ifdef LIGHTMODBUS_STATIC_MEM_MASTER_DATA
            union
            {
                uint8_t coils[LIGHTMODBUS_STATIC_MEM_MASTER_DATA];


                uint16_t regs[LIGHTMODBUS_STATIC_MEM_MASTER_DATA >> 1];
            };
        #else
            //Two separate pointers are used in case pointer size differed between types (possible on some weird architectures)

            uint8_t *coils;

            uint16_t *regs;
        #endif
    } data;

    struct
    {
        uint8_t address; 
        uint8_t function; 
        ModbusExceptionCode code; 
    } exception;

    ModbusFrameError parseError;

    ModbusFrameError buildError;

    //User defined functions
    #ifdef LIGHTMODBUS_MASTER_USER_FUNCTIONS

        ModbusMasterUserFunction *userFunctions;
        uint16_t userFunctionCount; 
    #endif

} ModbusMaster;
#endif

#include "master/mbregs.h"
#include "master/mbcoils.h"

#ifdef LIGHTMODBUS_MASTER_BASE

extern ModbusError modbusParseResponse( ModbusMaster *status );

extern ModbusError modbusMasterInit( ModbusMaster *status );

extern ModbusError modbusMasterEnd( ModbusMaster *status );
#endif

// For C++ (closes `extern "C"` )
#ifdef __cplusplus
}
#endif

#endif