nuttx-apps/modbus/functions/mbutils.c
2018-08-24 06:19:35 -06:00

163 lines
5.0 KiB
C

/****************************************************************************
* apps/functions/mbutils.c
*
* FreeModbus Library: A portable Modbus implementation for Modbus ASCII/RTU.
* Copyright (c) 2006 Christian Walter <wolti@sil.at>
* 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "port.h"
#include "modbus/mb.h"
#include "modbus/mbproto.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define BITS_uint8_t 8U
/****************************************************************************
* Public Functions
****************************************************************************/
void xMBUtilSetBits(uint8_t *ucByteBuf, uint16_t usBitOffset,
uint8_t ucNBits, uint8_t ucValue)
{
uint16_t usWordBuf;
uint16_t usMask;
uint16_t usByteOffset;
uint16_t usNPreBits;
uint16_t usValue = ucValue;
DEBUGASSERT(ucNBits <= 8);
DEBUGASSERT((size_t)BITS_uint8_t == sizeof(uint8_t) * 8);
/* Calculate byte offset for first byte containing the bit values starting
* at usBitOffset.
*/
usByteOffset = (uint16_t)((usBitOffset) / BITS_uint8_t);
/* How many bits precede our bits to set. */
usNPreBits = (uint16_t)(usBitOffset - usByteOffset * BITS_uint8_t);
/* Move bit field into position over bits to set */
usValue <<= usNPreBits;
/* Prepare a mask for setting the new bits. */
usMask = (uint16_t)((1 << (uint16_t) ucNBits) - 1);
usMask <<= usBitOffset - usByteOffset * BITS_uint8_t;
/* copy bits into temporary storage. */
usWordBuf = ucByteBuf[usByteOffset];
usWordBuf |= ucByteBuf[usByteOffset + 1] << BITS_uint8_t;
/* Zero out bit field bits and then or value bits into them. */
usWordBuf = (uint16_t)((usWordBuf & (~usMask)) | usValue);
/* move bits back into storage */
ucByteBuf[usByteOffset] = (uint8_t)(usWordBuf & 0xFF);
ucByteBuf[usByteOffset + 1] = (uint8_t)(usWordBuf >> BITS_uint8_t);
}
uint8_t xMBUtilGetBits(uint8_t *ucByteBuf, uint16_t usBitOffset, uint8_t ucNBits)
{
uint16_t usWordBuf;
uint16_t usMask;
uint16_t usByteOffset;
uint16_t usNPreBits;
/* Calculate byte offset for first byte containing the bit values starting
* at usBitOffset.
*/
usByteOffset = (uint16_t)((usBitOffset) / BITS_uint8_t);
/* How many bits precede our bits to set. */
usNPreBits = (uint16_t)(usBitOffset - usByteOffset * BITS_uint8_t);
/* Prepare a mask for setting the new bits. */
usMask = (uint16_t)((1 << (uint16_t) ucNBits) - 1);
/* copy bits into temporary storage. */
usWordBuf = ucByteBuf[usByteOffset];
usWordBuf |= ucByteBuf[usByteOffset + 1] << BITS_uint8_t;
/* throw away unneeded bits. */
usWordBuf >>= usNPreBits;
/* mask away bits above the requested bitfield. */
usWordBuf &= usMask;
return (uint8_t) usWordBuf;
}
eMBException prveMBError2Exception(eMBErrorCode eErrorCode)
{
eMBException eStatus;
switch (eErrorCode)
{
case MB_ENOERR:
eStatus = MB_EX_NONE;
break;
case MB_ENOREG:
eStatus = MB_EX_ILLEGAL_DATA_ADDRESS;
break;
case MB_ETIMEDOUT:
eStatus = MB_EX_SLAVE_BUSY;
break;
default:
eStatus = MB_EX_SLAVE_DEVICE_FAILURE;
break;
}
return eStatus;
}