1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
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
47#ifndef _SYS_CLOCK_H_
48#define _SYS_CLOCK_H_
49
50#ifdef _KERNEL /* No user serviceable parts */
51
52int utc_offset(void);
53
54/*
55 * Structure to hold the values typically reported by time-of-day clocks,
56 * expressed as binary integers (see below for a BCD version). This can be
57 * passed to the conversion functions to be converted to/from a struct timespec.
58 *
59 * On input, the year is interpreted as follows:
60 * 0 - 69 = 2000 - 2069
61 * 70 - 99 = 1970 - 1999
62 * 100 - 199 = 2000 - 2099 (Supports hardware "century bit".)
63 * 200 - 1969 = Invalid.
64 * 1970 - 9999 = Full 4-digit century+year.
65 *
66 * The dow field is ignored (not even validated) on input, but is always
67 * populated with day-of-week on output.
68 *
69 * clock_ct_to_ts() returns EINVAL if any values are out of range. The year
70 * field will always be 4-digit on output.
71 */
72struct clocktime {
73 int year; /* year (4 digit year) */
74 int mon; /* month (1 - 12) */
75 int day; /* day (1 - 31) */
76 int hour; /* hour (0 - 23) */
77 int min; /* minute (0 - 59) */
78 int sec; /* second (0 - 59) */
79 int dow; /* day of week (0 - 6; 0 = Sunday) */
80 long nsec; /* nano seconds */
81};
82
83int clock_ct_to_ts(const struct clocktime *, struct timespec *);
84void clock_ts_to_ct(const struct timespec *, struct clocktime *);
85
86/*
87 * Structure to hold the values typically reported by time-of-day clocks,
88 * expressed as BCD. This can be passed to the conversion functions to be
89 * converted to/from a struct timespec.
90 *
91 * The clock_bcd_to_ts() function interprets the values in the year through sec
92 * fields as BCD numbers, and returns EINVAL if any BCD values are out of range.
93 * After conversion to binary, the values are passed to clock_ct_to_ts() and
94 * undergo further validation as described above. Year may be 2 or 4-digit BCD,
95 * interpreted as described above. The nsec field is binary. If the ampm arg
96 * is true, the incoming hour and ispm values are interpreted as 12-hour am/pm
97 * representation of the hour, otherwise hour is interpreted as 24-hour and ispm
98 * is ignored.
99 *
100 * The clock_ts_to_bcd() function converts the timespec to BCD values stored
101 * into year through sec. The value in year will be 4-digit BCD (e.g.,
102 * 0x2017). The mon through sec values will be 2-digit BCD. The nsec field will
103 * be binary, and the range of dow makes its binary and BCD values identical.
104 * If the ampm arg is true, the hour and ispm fields are set to the 12-hour
105 * time plus a pm flag, otherwise the hour is set to 24-hour time and ispm is
106 * set to false.
107 */
108struct bcd_clocktime {
109 uint16_t year; /* year (2 or 4 digit year) */
110 uint8_t mon; /* month (1 - 12) */
111 uint8_t day; /* day (1 - 31) */
112 uint8_t hour; /* hour (0 - 23 or 1 - 12) */
113 uint8_t min; /* minute (0 - 59) */
114 uint8_t sec; /* second (0 - 59) */
115 uint8_t dow; /* day of week (0 - 6; 0 = Sunday) */
116 long nsec; /* nanoseconds */
117 bool ispm; /* true if hour represents pm time */
118};
119
120int clock_bcd_to_ts(const struct bcd_clocktime *, struct timespec *, bool ampm);
121void clock_ts_to_bcd(const struct timespec *, struct bcd_clocktime *, bool ampm);
122
123/*
124 * Time-of-day clock functions and flags. These functions might sleep.
125 *
126 * clock_register and clock_unregister() do what they say. Upon return from
127 * unregister, the clock's methods are not running and will not be called again.
128 *
129 * clock_schedule() requests that a registered clock's clock_settime() calls
130 * happen at the given offset into the second. The default is 0, meaning no
131 * specific scheduling. To schedule the call as soon after top-of-second as
132 * possible, specify 1. Each clock has its own schedule, but taskqueue_thread
133 * is shared by many tasks; the timing of the call is not guaranteed.
134 *
135 * Flags:
136 *
137 * CLOCKF_SETTIME_NO_TS
138 * Do not pass a timespec to clock_settime(), the driver obtains its own time
139 * and applies its own adjustments (this flag implies CLOCKF_SETTIME_NO_ADJ).
140 *
141 * CLOCKF_SETTIME_NO_ADJ
142 * Do not apply utc offset and resolution/accuracy adjustments to the value
143 * passed to clock_settime(), the driver applies them itself.
144 *
145 * CLOCKF_GETTIME_NO_ADJ
146 * Do not apply utc offset and resolution/accuracy adjustments to the value
147 * returned from clock_gettime(), the driver has already applied them.
148 */
149
150#define CLOCKF_SETTIME_NO_TS 0x00000001
151#define CLOCKF_SETTIME_NO_ADJ 0x00000002
152#define CLOCKF_GETTIME_NO_ADJ 0x00000004
153
154void clock_register(device_t _clockdev, long _resolution_us);
155void clock_register_flags(device_t _clockdev, long _resolution_us, int _flags);
156void clock_schedule(device_t clockdev, u_int _offsetns);
157void clock_unregister(device_t _clockdev);
158
159/*
160 * BCD to decimal and decimal to BCD.
161 */
162#define FROMBCD(x) bcd2bin(x)
163#define TOBCD(x) bin2bcd(x)
164
165/* Some handy constants. */
166#define SECDAY (24 * 60 * 60)
167#define SECYR (SECDAY * 365)
168
169/* Traditional POSIX base year */
170#define POSIX_BASE_YEAR 1970
171
172void timespec2fattime(const struct timespec *tsp, int utc, u_int16_t *ddp,
173 u_int16_t *dtp, u_int8_t *dhp);
174void fattime2timespec(unsigned dd, unsigned dt, unsigned dh, int utc,
175 struct timespec *tsp);
176
177/*
178 * Print a [bcd_]clocktime or timespec, optionally with fractional seconds. The
179 * nsdig argument can range from 0-9, and specifies how many decimal digits to
180 * display for fractional seconds.
181 */
182void clock_print_bcd(const struct bcd_clocktime *bct, int nsdig);
183void clock_print_ct(const struct clocktime *ct, int nsdig);
184void clock_print_ts(const struct timespec *ts, int nsdig);
185
186/*
187 * Debugging helpers for RTC clock drivers. Print a [bcd_]clocktime or
188 * timespec, only if rtc clock debugging has been enabled. The rw argument is
189 * one of CLOCK_DBG_READ or CLOCK_DBG_WRITE.
190 */
191#define CLOCK_DBG_READ 0x01
192#define CLOCK_DBG_WRITE 0x02
193void clock_dbgprint_bcd(device_t dev, int rw, const struct bcd_clocktime *bct);
194void clock_dbgprint_ct(device_t dev, int rw, const struct clocktime *ct);
195void clock_dbgprint_err(device_t dev, int rw, int err);
196void clock_dbgprint_ts(device_t dev, int rw, const struct timespec *ts);
197
198#endif /* _KERNEL */
199
200#endif /* !_SYS_CLOCK_H_ */