xref: /illumos-gate/usr/src/lib/libc/port/gen/cfsetispeed.c (revision 581cede61ac9c14d8d4ea452562a567189eead78)
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 }
63