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openblt/Host/Source/LibOpenBLT/port/linux/serialport.c

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/************************************************************************************//**
* \file port/linux/serialport.c
* \brief Serial port source file.
* \ingroup Session
* \internal
*----------------------------------------------------------------------------------------
* C O P Y R I G H T
*----------------------------------------------------------------------------------------
* Copyright (c) 2017 by Feaser http://www.feaser.com All rights reserved
*
*----------------------------------------------------------------------------------------
* L I C E N S E
*----------------------------------------------------------------------------------------
* This file is part of OpenBLT. OpenBLT 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.
*
* OpenBLT 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 have received a copy of the GNU General Public License along with OpenBLT. It
* should be located in ".\Doc\license.html". If not, contact Feaser to obtain a copy.
*
* \endinternal
****************************************************************************************/
/****************************************************************************************
* Include files
****************************************************************************************/
#include <assert.h> /* for assertions */
#include <stdint.h> /* for standard integer types */
#include <stddef.h> /* for NULL declaration */
#include <stdbool.h> /* for boolean type */
#include <unistd.h> /* UNIX standard functions */
#include <termios.h> /* POSIX terminal control */
#include <fcntl.h> /* file control definitions */
#include <sys/ioctl.h> /* system I/O control */
#include "serialport.h" /* serial port module */
/****************************************************************************************
* Macro definitions
****************************************************************************************/
/** \brief Invalid serial port device handle. */
#define SERIALPORT_INVALID_HANDLE (-1)
/****************************************************************************************
* Local data declarations
****************************************************************************************/
/** \brief Serial port handle. */
static int32_t portHandle;
/****************************************************************************************
* Local constant declarations
****************************************************************************************/
/** \brief Lookup table for converting this module's generic baudrate value to a value
* supported by the low level interface.
*/
static const speed_t baudrateLookup[] =
{
B9600, /**< Index 0 = SERIALPORT_BR9600 */
B19200, /**< Index 1 = SERIALPORT_BR19200 */
B38400, /**< Index 2 = SERIALPORT_BR38400 */
B57600, /**< Index 3 = SERIALPORT_BR57600 */
B115200 /**< Index 4 = SERIALPORT_BR115200 */
};
/************************************************************************************//**
** \brief Initializes the serial port module.
**
****************************************************************************************/
void SerialPortInit(void)
{
/* Invalidate the port handle. */
portHandle = SERIALPORT_INVALID_HANDLE;
} /*** end of SerialPortInit ***/
/************************************************************************************//**
** \brief Terminates the serial port module.
**
****************************************************************************************/
void SerialPortTerminate(void)
{
/* Make sure the serial port is closed. */
SerialPortClose();
} /*** end of SerialPortTerminate ***/
/************************************************************************************//**
** \brief Opens the connection with the serial port configured as 8,N,1 and no flow
** control.
** \param portname The name of the serial port to open, i.e. /dev/ttyUSB0.
** \param baudrate The desired communication speed.
** \return True if successful, false otherwise.
**
****************************************************************************************/
bool SerialPortOpen(char const * portname, tSerialPortBaudrate baudrate)
{
bool result = false;
struct termios options = { 0 };
int32_t iFlags;
/* Check parameters. */
assert(portname != NULL);
/* Only continue with valid parameters. */
if (portname != NULL) /*lint !e774 */
{
/* Assume the result to be okay from here on and only set it to error when a problem
* was detected.
*/
result = true;
/* Open the port. */
portHandle = open(portname, O_RDWR | O_NOCTTY | O_NDELAY);
/* Check the result */
if (portHandle == SERIALPORT_INVALID_HANDLE)
{
result = false;
}
/* Configure the device to block during read operations. */
if (result)
{
if (fcntl(portHandle, F_SETFL, 0) == -1)
{
SerialPortClose();
result = false;
}
}
/* Get the current options for the port. */
if (result)
{
if (tcgetattr(portHandle, &options) == -1)
{
SerialPortClose();
result = false;
}
}
/* Configure the baudrate. */
if (result)
{
if (cfsetispeed(&options, baudrateLookup[baudrate]) == -1)
{
SerialPortClose();
result = false;
}
}
if (result)
{
if (cfsetospeed(&options, baudrateLookup[baudrate]) == -1)
{
SerialPortClose();
result = false;
}
}
if (result)
{
/* Input modes - clear indicated ones giving: no break, no CR to NL,
* no parity check, no strip char, no start/stop output (sic) control.
*/
options.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
/* Output modes - clear giving: no post processing such as NL to CR+NL. */
options.c_oflag &= ~(OPOST);
/* Control modes - set 8 bit chars */
options.c_cflag |= (CS8);
/* Local modes - clear giving: echoing off, canonical off (no erase with
* backspace, ^U,...), no extended functions, no signal chars (^Z,^C).
*/
options.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
/* Configure timeouts. */
options.c_cc[VMIN] = 0;
options.c_cc[VTIME] = 1; /* in units of 1/10th of a second */
/* Set the new options for the port. */
if (tcsetattr(portHandle, TCSAFLUSH, &options) == -1)
{
SerialPortClose();
result = false;
}
}
/* Turn on DTR. */
if (result)
{
iFlags = TIOCM_DTR;
if (ioctl(portHandle, TIOCMBIS, &iFlags) == -1)
{
SerialPortClose();
result = false;
}
}
}
/* Give the result back to the caller. */
return result;
} /*** end of SerialPortOpen ***/
/************************************************************************************//**
** \brief Closes the connection with the serial port.
**
****************************************************************************************/
void SerialPortClose(void)
{
/* Close the port handle if valid. */
if (portHandle != SERIALPORT_INVALID_HANDLE)
{
close(portHandle);
}
/* Invalidate handle. */
portHandle = SERIALPORT_INVALID_HANDLE;
} /*** end of SerialPortClose ***/
/************************************************************************************//**
** \brief Writes data to the serial port.
** \param data Pointer to byte array with data to write.
** \param length Number of bytes to write.
** \return True if successful, false otherwise.
**
****************************************************************************************/
bool SerialPortWrite(uint8_t const * data, uint32_t length)
{
bool result = false;
/* Check parameters. */
assert(data != NULL);
assert(length > 0);
/* Only continue with valid parameters. */
if ( (data != NULL) && (length > 0) ) /*lint !e774 */
{
/* Submit the data for sending. */
if ((uint32_t)write(portHandle, data, length) == length)
{
result = true;
}
}
/* Give the result back to the caller. */
return result;
} /*** end of SerialPortWrite ***/
/************************************************************************************//**
** \brief Reads data from the serial port in a blocking manner.
** \param data Pointer to byte array to store read data.
** \param length Number of bytes to read.
** \return True if successful, false otherwise.
**
****************************************************************************************/
bool SerialPortRead(uint8_t * data, uint32_t length)
{
bool result = false;
/* Check parameters. */
assert(data != NULL);
assert(length > 0);
/* Only continue with valid parameters. */
if ( (data != NULL) && (length > 0) ) /*lint !e774 */
{
/* Attempt to read the requested data. */
if ((uint32_t)read(portHandle, data, length) == length)
{
result = true;
}
}
/* Give the result back to the caller. */
return result;
} /*** end of SerialPortRead ***/
/*********************************** end of serialport.c *******************************/
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