1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1996 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Gordon W. Ross
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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 *
31 *	$NetBSD: clock_subr.h,v 1.7 2000/10/03 13:41:07 tsutsui Exp $
32 *
33 *
34 * This file is the central clearing-house for calendrical issues.
35 *
36 * In general the kernel does not know about minutes, hours, days, timezones,
37 * daylight savings time, leap-years and such.  All that is theoretically a
38 * matter for userland only.
39 *
40 * Parts of kernel code does however care: badly designed filesystems store
41 * timestamps in local time and RTC chips sometimes track time in a local
42 * timezone instead of UTC and so on.
43 *
44 * All that code should go here for service.
45 *
46 * $FreeBSD$
47 */
48
49#ifndef _SYS_CLOCK_H_
50#define _SYS_CLOCK_H_
51
52#ifdef _KERNEL		/* No user serviceable parts */
53
54int utc_offset(void);
55
56/*
57 * Structure to hold the values typically reported by time-of-day clocks,
58 * expressed as binary integers (see below for a BCD version).  This can be
59 * passed to the conversion functions to be converted to/from a struct timespec.
60 *
61 * On input, the year is interpreted as follows:
62 *       0 -   69 = 2000 - 2069
63 *      70 -   99 = 1970 - 1999
64 *     100 -  199 = 2000 - 2099 (Supports hardware "century bit".)
65 *     200 - 1969 = Invalid.
66 *    1970 - 9999 = Full 4-digit century+year.
67 *
68 * The dow field is ignored (not even validated) on input, but is always
69 * populated with day-of-week on output.
70 *
71 * clock_ct_to_ts() returns EINVAL if any values are out of range.  The year
72 * field will always be 4-digit on output.
73 */
74struct clocktime {
75	int	year;			/* year (4 digit year) */
76	int	mon;			/* month (1 - 12) */
77	int	day;			/* day (1 - 31) */
78	int	hour;			/* hour (0 - 23) */
79	int	min;			/* minute (0 - 59) */
80	int	sec;			/* second (0 - 59) */
81	int	dow;			/* day of week (0 - 6; 0 = Sunday) */
82	long	nsec;			/* nano seconds */
83};
84
85int clock_ct_to_ts(const struct clocktime *, struct timespec *);
86void clock_ts_to_ct(const struct timespec *, struct clocktime *);
87
88/*
89 * Structure to hold the values typically reported by time-of-day clocks,
90 * expressed as BCD.  This can be passed to the conversion functions to be
91 * converted to/from a struct timespec.
92 *
93 * The clock_bcd_to_ts() function interprets the values in the year through sec
94 * fields as BCD numbers, and returns EINVAL if any BCD values are out of range.
95 * After conversion to binary, the values are passed to clock_ct_to_ts() and
96 * undergo further validation as described above.  Year may be 2 or 4-digit BCD,
97 * interpreted as described above.  The nsec field is binary.  If the ampm arg
98 * is true, the incoming hour and ispm values are interpreted as 12-hour am/pm
99 * representation of the hour, otherwise hour is interpreted as 24-hour and ispm
100 * is ignored.
101 *
102 * The clock_ts_to_bcd() function converts the timespec to BCD values stored
103 * into year through sec.  The value in year will be 4-digit BCD (e.g.,
104 * 0x2017). The mon through sec values will be 2-digit BCD.  The nsec field will
105 * be binary, and the range of dow makes its binary and BCD values identical.
106 * If the ampm arg is true, the hour and ispm fields are set to the 12-hour
107 * time plus a pm flag, otherwise the hour is set to 24-hour time and ispm is
108 * set to false.
109 */
110struct bcd_clocktime {
111	uint16_t year;			/* year (2 or 4 digit year) */
112	uint8_t  mon;			/* month (1 - 12) */
113	uint8_t  day;			/* day (1 - 31) */
114	uint8_t  hour;			/* hour (0 - 23 or 1 - 12) */
115	uint8_t  min;			/* minute (0 - 59) */
116	uint8_t  sec;			/* second (0 - 59) */
117	uint8_t  dow;			/* day of week (0 - 6; 0 = Sunday) */
118	long     nsec;			/* nanoseconds */
119	bool     ispm;			/* true if hour represents pm time */
120};
121
122int clock_bcd_to_ts(const struct bcd_clocktime *, struct timespec *, bool ampm);
123void clock_ts_to_bcd(const struct timespec *, struct bcd_clocktime *, bool ampm);
124
125/*
126 * Time-of-day clock functions and flags.  These functions might sleep.
127 *
128 * clock_register and clock_unregister() do what they say.  Upon return from
129 * unregister, the clock's methods are not running and will not be called again.
130 *
131 * clock_schedule() requests that a registered clock's clock_settime() calls
132 * happen at the given offset into the second.  The default is 0, meaning no
133 * specific scheduling.  To schedule the call as soon after top-of-second as
134 * possible, specify 1.  Each clock has its own schedule, but taskqueue_thread
135 * is shared by many tasks; the timing of the call is not guaranteed.
136 *
137 * Flags:
138 *
139 *  CLOCKF_SETTIME_NO_TS
140 *    Do not pass a timespec to clock_settime(), the driver obtains its own time
141 *    and applies its own adjustments (this flag implies CLOCKF_SETTIME_NO_ADJ).
142 *
143 *  CLOCKF_SETTIME_NO_ADJ
144 *    Do not apply utc offset and resolution/accuracy adjustments to the value
145 *    passed to clock_settime(), the driver applies them itself.
146 *
147 *  CLOCKF_GETTIME_NO_ADJ
148 *    Do not apply utc offset and resolution/accuracy adjustments to the value
149 *    returned from clock_gettime(), the driver has already applied them.
150 */
151
152#define	CLOCKF_SETTIME_NO_TS	0x00000001
153#define	CLOCKF_SETTIME_NO_ADJ	0x00000002
154#define	CLOCKF_GETTIME_NO_ADJ	0x00000004
155
156void clock_register(device_t _clockdev, long _resolution_us);
157void clock_register_flags(device_t _clockdev, long _resolution_us, int _flags);
158void clock_schedule(device_t clockdev, u_int _offsetns);
159void clock_unregister(device_t _clockdev);
160
161/*
162 * BCD to decimal and decimal to BCD.
163 */
164#define	FROMBCD(x)	bcd2bin(x)
165#define	TOBCD(x)	bin2bcd(x)
166
167/* Some handy constants. */
168#define SECDAY		(24 * 60 * 60)
169#define SECYR		(SECDAY * 365)
170
171/* Traditional POSIX base year */
172#define	POSIX_BASE_YEAR	1970
173
174void timespec2fattime(const struct timespec *tsp, int utc, u_int16_t *ddp,
175    u_int16_t *dtp, u_int8_t *dhp);
176void fattime2timespec(unsigned dd, unsigned dt, unsigned dh, int utc,
177    struct timespec *tsp);
178
179/*
180 * Print a [bcd_]clocktime or timespec, optionally with fractional seconds.  The
181 * nsdig argument can range from 0-9, and specifies how many decimal digits to
182 * display for fractional seconds.
183 */
184void clock_print_bcd(const struct bcd_clocktime *bct, int nsdig);
185void clock_print_ct(const struct clocktime *ct, int nsdig);
186void clock_print_ts(const struct timespec  *ts, int nsdig);
187
188/*
189 * Debugging helpers for RTC clock drivers.  Print a [bcd_]clocktime or
190 * timespec, only if rtc clock debugging has been enabled.  The rw argument is
191 * one of CLOCK_DBG_READ or CLOCK_DBG_WRITE.
192 */
193#define	CLOCK_DBG_READ	0x01
194#define	CLOCK_DBG_WRITE	0x02
195void clock_dbgprint_bcd(device_t dev, int rw, const struct bcd_clocktime *bct);
196void clock_dbgprint_ct(device_t dev, int rw, const struct clocktime *ct);
197void clock_dbgprint_err(device_t dev, int rw, int err);
198void clock_dbgprint_ts(device_t dev, int rw, const struct timespec *ts);
199
200#endif /* _KERNEL */
201
202#endif /* !_SYS_CLOCK_H_ */
203