/**************************************************************************** * libc/termios/lib_cfsetspeed.c * * Copyright (C) 2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 NuttX 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include /**************************************************************************** * Name: cfsetspeed * * Descripton: * The cfsetspeed() function is a non-POSIX function that sets the baud * stored in the structure pointed to by termiosp to speed. * * There is no effect on the baud set in the hardware until a subsequent * successful call to tcsetattr() on the same termios structure. * * NOTE 1: NuttX does not control input/output baud independently. Both * must be the same. The POSIX standard interfaces, cfisetispeed() and * cfisetospeed() are defined to be cfsetspeed() in termios.h. * * NOTE 3: A consequence of NOTE 1 is that you should never attempt to * set the input and output baud to different values. * * Also, the following POSIX requirement cannot be supported: "If the input * baud rate stored in the termios structure pointed to by termios_p is 0, * the input baud rate given to the hardware will be the same as the output * baud rate stored in the termios structure." * * NOTE 2. In Nuttx, the speed_t is defined to be uint32_t and the baud * encodings of termios.h are the actual baud values themselves. Therefore, * any baud value can be provided as the speed argument here. However, if * you do so, your code will *NOT* be portable to other environments where * speed_t is smaller and where the termios.h baud values are encoded! To * avoid portability issues, use the baud definitions in termios.h! * * Linux, for example, would require this (also non-portable) sequence: * * cfsetispeed(termiosp, BOTHER); * termiosp->c_ispeed = baud; * * cfsetospeed(termiosp, BOTHER); * termiosp->c_ospeed = baud; * * Input Parameters: * termiosp - The termiosp argument is a pointer to a termios structure. * speed - The new input speed * * Returned Value: * Baud is not checked... OK is always returned (this is non-standard * behavior). * ****************************************************************************/ int cfsetspeed(FAR struct termios *termiosp, speed_t speed) { DEBUGASSERT(termiosp); termiosp->c_speed = speed; return OK; }