xref: /netbsd/sys/arch/mvme68k/stand/libsa/chiptotime.c (revision 6550d01e)
1 /*	$NetBSD: chiptotime.c,v 1.4 2008/01/12 09:54:32 tsutsui Exp $ */
2 
3 #include <sys/types.h>
4 
5 #include <machine/prom.h>
6 
7 #include <lib/libsa/stand.h>
8 #include "libsa.h"
9 
10 /*
11  * BCD to decimal and decimal to BCD.
12  */
13 #define FROMBCD(x)      (int)((((unsigned int)(x)) >> 4) * 10 +\
14 				(((unsigned int)(x)) & 0xf))
15 #define TOBCD(x)        (int)((((unsigned int)(x)) / 10 * 16) +\
16 				(((unsigned int)(x)) % 10))
17 
18 #define SECDAY          (24 * 60 * 60)
19 #define SECYR           (SECDAY * 365)
20 #define LEAPYEAR(y)     (((y) & 3) == 0)
21 #define YEAR0		68
22 
23 /*
24  * This code is defunct after 2068.
25  * Will Unix still be here then??
26  */
27 const short dayyr[12] =
28     {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
29 
30 u_long
31 chiptotime(int sec, int min, int hour, int day, int mon, int year)
32 {
33 	int days, yr;
34 
35 	sec = FROMBCD(sec);
36 	min = FROMBCD(min);
37 	hour = FROMBCD(hour);
38 	day = FROMBCD(day);
39 	mon = FROMBCD(mon);
40 	year = FROMBCD(year) + YEAR0;
41 	if (year < 70)
42 		year = 70;
43 
44 	/* simple sanity checks */
45 	if (year < 70 || mon < 1 || mon > 12 || day < 1 || day > 31)
46 		return (0);
47 	days = 0;
48 	for (yr = 70; yr < year; yr++)
49 		days += LEAPYEAR(yr) ? 366 : 365;
50 	days += dayyr[mon - 1] + day - 1;
51 	if (LEAPYEAR(yr) && mon > 2)
52 		days++;
53 	/* now have days since Jan 1, 1970; the rest is easy... */
54 	return days * SECDAY + hour * 3600 + min * 60 + sec;
55 }
56