diff options
Diffstat (limited to 'src/drivers/hott/comms.cpp')
-rw-r--r-- | src/drivers/hott/comms.cpp | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/src/drivers/hott/comms.cpp b/src/drivers/hott/comms.cpp new file mode 100644 index 000000000..cb8bbba37 --- /dev/null +++ b/src/drivers/hott/comms.cpp @@ -0,0 +1,92 @@ +/**************************************************************************** + * + * 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; +} |