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/****************************************************************************
*
* Copyright (c) 2013 PX4 Development Team. 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. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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 comms.c
* @author Simon Wilks <sjwilks@gmail.com>
*
*/
#include "comms.h"
#include <fcntl.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <systemlib/err.h>
#include <termios.h>
int
open_uart(const char *device)
{
/* baud rate */
static const speed_t speed = B19200;
/* open uart */
const int uart = open(device, O_RDWR | O_NOCTTY);
if (uart < 0) {
err(1, "Error opening port: %s", device);
}
/* Back up the original uart configuration to restore it after exit */
int termios_state;
struct termios uart_config_original;
if ((termios_state = tcgetattr(uart, &uart_config_original)) < 0) {
close(uart);
err(1, "Error getting baudrate / termios config for %s: %d", device, termios_state);
}
/* Fill the struct for the new configuration */
struct termios uart_config;
tcgetattr(uart, &uart_config);
/* Clear ONLCR flag (which appends a CR for every LF) */
uart_config.c_oflag &= ~ONLCR;
/* Set baud rate */
if (cfsetispeed(&uart_config, speed) < 0 || cfsetospeed(&uart_config, speed) < 0) {
close(uart);
err(1, "Error setting baudrate / termios config for %s: %d (cfsetispeed, cfsetospeed)",
device, termios_state);
}
if ((termios_state = tcsetattr(uart, TCSANOW, &uart_config)) < 0) {
close(uart);
err(1, "Error setting baudrate / termios config for %s (tcsetattr)", device);
}
/* Activate single wire mode */
ioctl(uart, TIOCSSINGLEWIRE, SER_SINGLEWIRE_ENABLED);
return uart;
}
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