usr/src/lib/libc/port/gen/cfsetispeed.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #pragma weak _cfsetispeed = cfsetispeed
  33
  34 #include "lint.h"
  35 #include <sys/types.h>
  36 #include <sys/termios.h>
  37
  38 /*
  39  * sets the input baud rate stored in c_cflag to speed
  40  */
  41
  42 int
  43 cfsetispeed(struct termios *termios_p, speed_t speed)
  44 {
  45         /*
  46          * If the input speed is zero, set it to output speed
  47          */
  48         if (speed == 0) {
  49                 speed = termios_p->c_cflag & CBAUD;
  50                 if (termios_p->c_cflag & CBAUDEXT)
  51                         speed += (CBAUD + 1);
  52         }
  53
  54         if ((speed << 16) > CIBAUD) {
  55                 termios_p->c_cflag |= CIBAUDEXT;
  56                 speed -= ((CIBAUD >> 16) + 1);
  57         } else
  58                 termios_p->c_cflag &= ~CIBAUDEXT;
  59         termios_p->c_cflag =
  60             (termios_p->c_cflag & ~CIBAUD) | ((speed << 16) & CIBAUD);
  61         return (0);
  62 }