/****************************************************************************
* apps/modbus/nuttx/portserial.c
*
* FreeModbus Library: NuttX Port
* 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 <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/select.h>
#include <sys/time.h>
#include <fcntl.h>
#include <unistd.h>
#include <assert.h>
#ifdef CONFIG_SERIAL_TERMIOS
# include <termios.h>
#endif
#include "port.h"
#include <apps/modbus/mb.h>
#include <apps/modbus/mbport.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#ifdef CONFIG_MB_ASCII_ENABLED
#define BUF_SIZE 513 /* must hold a complete ASCII frame. */
#else
#define BUF_SIZE 256 /* must hold a complete RTU frame. */
#endif
/****************************************************************************
* Private Data
****************************************************************************/
static int iSerialFd = -1;
static bool bRxEnabled;
static bool bTxEnabled;
static uint32_t ulTimeoutMs;
static uint8_t ucBuffer[BUF_SIZE];
static int uiRxBufferPos;
static int uiTxBufferPos;
#ifdef CONFIG_SERIAL_TERMIOS
static struct termios xOldTIO;
#endif
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static bool prvbMBPortSerialRead(uint8_t *pucBuffer, uint16_t usNBytes,
uint16_t *usNBytesRead);
static bool prvbMBPortSerialWrite(uint8_t *pucBuffer, uint16_t usNBytes);
/****************************************************************************
* Private Functions
****************************************************************************/
static bool prvbMBPortSerialRead(uint8_t *pucBuffer, uint16_t usNBytes,
uint16_t *usNBytesRead)
{
bool bResult = true;
ssize_t res;
fd_set rfds;
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 50000;
FD_ZERO(&rfds);
FD_SET(iSerialFd, &rfds);
/* Wait until character received or timeout. Recover in case of an
* interrupted read system call.
*/
do
{
if (select(iSerialFd + 1, &rfds, NULL, NULL, &tv) == -1)
{
if (errno != EINTR)
{
bResult = false;
}
}
else if (FD_ISSET(iSerialFd, &rfds))
{
if ((res = read(iSerialFd, pucBuffer, usNBytes)) == -1)
{
bResult = false;
}
else
{
*usNBytesRead = (uint16_t)res;
break;
}
}
else
{
*usNBytesRead = 0;
break;
}
}
while (bResult == true);
return bResult;
}
static bool prvbMBPortSerialWrite(uint8_t *pucBuffer, uint16_t usNBytes)
{
ssize_t res;
size_t left = (size_t) usNBytes;
size_t done = 0;
while (left > 0)
{
if ((res = write(iSerialFd, pucBuffer + done, left)) == -1)
{
if (errno != EINTR)
{
break;
}
/* call write again because of interrupted system call. */
continue;
}
done += res;
left -= res;
}
return left == 0 ? true : false;
}
/****************************************************************************
* Public Functions
****************************************************************************/
void vMBPortSerialEnable(bool bEnableRx, bool bEnableTx)
{
/* it is not allowed that both receiver and transmitter are enabled. */
ASSERT(!bEnableRx || !bEnableTx);
if (bEnableRx)
{
#ifdef CONFIG_SERIAL_TERMIOS
(void)tcflush(iSerialFd, TCIFLUSH);
#endif
uiRxBufferPos = 0;
bRxEnabled = true;
}
else
{
bRxEnabled = false;
}
if (bEnableTx)
{
bTxEnabled = true;
uiTxBufferPos = 0;
}
else
{
bTxEnabled = false;
}
}
bool xMBPortSerialInit(uint8_t ucPort, speed_t ulBaudRate,
uint8_t ucDataBits, eMBParity eParity)
{
char szDevice[16];
bool bStatus = true;
#ifdef CONFIG_SERIAL_TERMIOS
struct termios xNewTIO;
#endif
snprintf(szDevice, 16, "/dev/ttyS%d", ucPort);
if ((iSerialFd = open(szDevice, O_RDWR | O_NOCTTY)) < 0)
{
vMBPortLog(MB_LOG_ERROR, "SER-INIT", "Can't open serial port %s: %d\n",
szDevice, errno);
bStatus = false;
}
#ifdef CONFIG_SERIAL_TERMIOS
else if (tcgetattr(iSerialFd, &xOldTIO) != 0)
{
vMBPortLog(MB_LOG_ERROR, "SER-INIT", "Can't get settings from port %s: %d\n",
szDevice, errno);
}
else
{
bzero(&xNewTIO, sizeof(struct termios));
xNewTIO.c_iflag |= IGNBRK | INPCK;
xNewTIO.c_cflag |= CREAD | CLOCAL;
switch (eParity)
{
case MB_PAR_NONE:
break;
case MB_PAR_EVEN:
xNewTIO.c_cflag |= PARENB;
break;
case MB_PAR_ODD:
xNewTIO.c_cflag |= PARENB | PARODD;
break;
default:
bStatus = false;
}
switch (ucDataBits)
{
case 8:
xNewTIO.c_cflag |= CS8;
break;
case 7:
xNewTIO.c_cflag |= CS7;
break;
default:
bStatus = false;
}
if (bStatus)
{
/* Set the new baud. The following might be compatible with other
* OSs for the following reason.
*
* (1) In NuttX, cfset[i|o]speed always return OK so failures will
* really only be reported when tcsetattr() is called.
* (2) NuttX does not support separate input and output speeds so it
* is not necessary to call both cfsetispeed() and
* cfsetospeed(), and
* (3) In NuttX, the input value to cfiset[i|o]speed is not
* encoded, but is the absolute baud value. The following might
* not be
*/
if (cfsetispeed(&xNewTIO, ulBaudRate) != 0 /* || cfsetospeed(&xNewTIO, ulBaudRate) != 0 */)
{
vMBPortLog(MB_LOG_ERROR, "SER-INIT", "Can't set baud rate %ld for port %s: %d\n",
ulBaudRate, szDevice, errno);
}
else if (tcsetattr(iSerialFd, TCSANOW, &xNewTIO) != 0)
{
vMBPortLog(MB_LOG_ERROR, "SER-INIT", "Can't set settings for port %s: %d\n",
szDevice, errno);
}
else
{
vMBPortSerialEnable(false, false);
bStatus = true;
}
}
}
#endif
return bStatus;
}
bool xMBPortSerialSetTimeout(uint32_t ulNewTimeoutMs)
{
if (ulNewTimeoutMs > 0)
{
ulTimeoutMs = ulNewTimeoutMs;
}
else
{
ulTimeoutMs = 1;
}
return true;
}
void vMBPortClose(void)
{
if (iSerialFd != -1)
{
#ifdef CONFIG_SERIAL_TERMIOS
(void)tcsetattr(iSerialFd, TCSANOW, &xOldTIO);
#endif
(void)close(iSerialFd);
iSerialFd = -1;
}
}
bool xMBPortSerialPoll(void)
{
bool bStatus = true;
uint16_t usBytesRead;
int i;
while (bRxEnabled)
{
if (prvbMBPortSerialRead(&ucBuffer[0], BUF_SIZE, &usBytesRead))
{
if (usBytesRead == 0)
{
/* timeout with no bytes. */
break;
}
else if (usBytesRead > 0)
{
for (i = 0; i < usBytesRead; i++)
{
/* Call the modbus stack and let him fill the buffers. */
(void)pxMBFrameCBByteReceived();
}
uiRxBufferPos = 0;
}
}
else
{
vMBPortLog(MB_LOG_ERROR, "SER-POLL", "read failed on serial device: %d\n",
errno);
bStatus = false;
}
}
if (bTxEnabled)
{
while (bTxEnabled)
{
(void)pxMBFrameCBTransmitterEmpty();
/* Call the modbus stack to let him fill the buffer. */
}
if (!prvbMBPortSerialWrite(&ucBuffer[0], uiTxBufferPos))
{
vMBPortLog(MB_LOG_ERROR, "SER-POLL", "write failed on serial device: %d\n",
errno);
bStatus = false;
}
}
return bStatus;
}
bool xMBPortSerialPutByte(int8_t ucByte)
{
ASSERT(uiTxBufferPos < BUF_SIZE);
ucBuffer[uiTxBufferPos] = ucByte;
uiTxBufferPos++;
return true;
}
bool xMBPortSerialGetByte(int8_t *pucByte)
{
ASSERT(uiRxBufferPos < BUF_SIZE);
*pucByte = ucBuffer[uiRxBufferPos];
uiRxBufferPos++;
return true;
}