xref: /freebsd/contrib/ntp/libparse/gpstolfp.c (revision 050570efa79efcc9cf5adeb545f1a679c8dc377b)
1 /*
2  * /src/NTP/ntp4-dev/libntp/gpstolfp.c,v 4.8 2005/04/16 17:32:10 kardel RELEASE_20050508_A
3  *
4  * gpstolfp.c,v 4.8 2005/04/16 17:32:10 kardel RELEASE_20050508_A
5  *
6  * $Created: Sun Jun 28 16:30:38 1998 $
7  *
8  * Copyright (c) 1998-2005 by Frank Kardel <kardel <AT> ntp.org>
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the author nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  */
35 #include "ntp_fp.h"
36 
37 #define GPSORIGIN	ULONG_CONST(2524953600)	/* NTP origin - GPS origin in seconds */
38 #define SECSPERWEEK	(unsigned)(604800)	/* seconds per week - GPS tells us about weeks */
39 #define GPSWRAP		990	/* assume week count less than this in the previous epoch */
40 
41 void
42 gpstolfp(
43 	 int weeks,
44 	 int days,
45 	 unsigned long  seconds,
46 	 l_fp * lfp
47 	 )
48 {
49   if (weeks < GPSWRAP)
50     {
51       weeks += 1024;
52     }
53 
54   lfp->l_ui = weeks * SECSPERWEEK + days * 86400 + seconds + GPSORIGIN; /* convert to NTP time */
55   lfp->l_uf = 0;
56 }
57 
58 /*
59  * History:
60  *
61  * gpstolfp.c,v
62  * Revision 4.8  2005/04/16 17:32:10  kardel
63  * update copyright
64  *
65  * Revision 4.7  2004/11/14 15:29:41  kardel
66  * support PPSAPI, upgrade Copyright to Berkeley style
67  *
68  * Revision 4.3  1999/02/28 11:42:44  kardel
69  * (GPSWRAP): update GPS rollover to 990 weeks
70  *
71  * Revision 4.2  1998/07/11 10:05:25  kardel
72  * Release 4.0.73d reconcilation
73  *
74  * Revision 4.1  1998/06/28 16:47:15  kardel
75  * added gpstolfp() function
76  */
77