/**************************************************************************** * drivers/serial/tcdrain.c * * Copyright (C) 2017 Gregory Nutt. All rights reserved. * Copyright (C) 2017 Sebastien Lorquet. All rights reserved. * Author: Sebastien Lorquet * * 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 #include #include #include /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: tcdrain * * Descripton: * Function for draining the output buffer of a terminal/serial device * * Input Parameters: * fd - The 'fd' argument is an open file descriptor associated with a terminal. * * Returned Value: * Upon successful completion, 0 is returned. Otherwise, -1 is returned and * errno is set to indicate the error. * ****************************************************************************/ int tcdrain(int fd) { int ret; /* tcdrain is a cancellation point */ if (enter_cancellation_point()) { #ifdef CONFIG_CANCELLATION_POINTS /* If there is a pending cancellation, then do not perform * the wait. Exit now with ECANCELED. */ set_errno(ECANCELED); leave_cancellation_point(); return ERROR; #endif } /* Perform the TCDRM IOCTL command. It is safe to use the file descriptor * in this context because we are executing on the calling application's * thread. * * NOTE: ioctl() will set the errno variable and return ERROR is any error * occurs. */ ret = ioctl(fd, TCDRN, (unsigned long)0); leave_cancellation_point(); return ret; }