f-stack/freebsd/sys/clock.h

203 lines
8.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1996 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Gordon W. Ross
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* $NetBSD: clock_subr.h,v 1.7 2000/10/03 13:41:07 tsutsui Exp $
*
*
* This file is the central clearing-house for calendrical issues.
*
* In general the kernel does not know about minutes, hours, days, timezones,
* daylight savings time, leap-years and such. All that is theoretically a
* matter for userland only.
*
* Parts of kernel code does however care: badly designed filesystems store
* timestamps in local time and RTC chips sometimes track time in a local
* timezone instead of UTC and so on.
*
* All that code should go here for service.
*
* $FreeBSD$
*/
#ifndef _SYS_CLOCK_H_
#define _SYS_CLOCK_H_
#ifdef _KERNEL /* No user serviceable parts */
int utc_offset(void);
/*
* Structure to hold the values typically reported by time-of-day clocks,
* expressed as binary integers (see below for a BCD version). This can be
* passed to the conversion functions to be converted to/from a struct timespec.
*
* On input, the year is interpreted as follows:
* 0 - 69 = 2000 - 2069
* 70 - 99 = 1970 - 1999
* 100 - 199 = 2000 - 2099 (Supports hardware "century bit".)
* 200 - 1969 = Invalid.
* 1970 - 9999 = Full 4-digit century+year.
*
* The dow field is ignored (not even validated) on input, but is always
* populated with day-of-week on output.
*
* clock_ct_to_ts() returns EINVAL if any values are out of range. The year
* field will always be 4-digit on output.
*/
struct clocktime {
int year; /* year (4 digit year) */
int mon; /* month (1 - 12) */
int day; /* day (1 - 31) */
int hour; /* hour (0 - 23) */
int min; /* minute (0 - 59) */
int sec; /* second (0 - 59) */
int dow; /* day of week (0 - 6; 0 = Sunday) */
long nsec; /* nano seconds */
};
int clock_ct_to_ts(const struct clocktime *, struct timespec *);
void clock_ts_to_ct(const struct timespec *, struct clocktime *);
/*
* Structure to hold the values typically reported by time-of-day clocks,
* expressed as BCD. This can be passed to the conversion functions to be
* converted to/from a struct timespec.
*
* The clock_bcd_to_ts() function interprets the values in the year through sec
* fields as BCD numbers, and returns EINVAL if any BCD values are out of range.
* After conversion to binary, the values are passed to clock_ct_to_ts() and
* undergo further validation as described above. Year may be 2 or 4-digit BCD,
* interpreted as described above. The nsec field is binary. If the ampm arg
* is true, the incoming hour and ispm values are interpreted as 12-hour am/pm
* representation of the hour, otherwise hour is interpreted as 24-hour and ispm
* is ignored.
*
* The clock_ts_to_bcd() function converts the timespec to BCD values stored
* into year through sec. The value in year will be 4-digit BCD (e.g.,
* 0x2017). The mon through sec values will be 2-digit BCD. The nsec field will
* be binary, and the range of dow makes its binary and BCD values identical.
* If the ampm arg is true, the hour and ispm fields are set to the 12-hour
* time plus a pm flag, otherwise the hour is set to 24-hour time and ispm is
* set to false.
*/
struct bcd_clocktime {
uint16_t year; /* year (2 or 4 digit year) */
uint8_t mon; /* month (1 - 12) */
uint8_t day; /* day (1 - 31) */
uint8_t hour; /* hour (0 - 23 or 1 - 12) */
uint8_t min; /* minute (0 - 59) */
uint8_t sec; /* second (0 - 59) */
uint8_t dow; /* day of week (0 - 6; 0 = Sunday) */
long nsec; /* nanoseconds */
bool ispm; /* true if hour represents pm time */
};
int clock_bcd_to_ts(const struct bcd_clocktime *, struct timespec *, bool ampm);
void clock_ts_to_bcd(const struct timespec *, struct bcd_clocktime *, bool ampm);
/*
* Time-of-day clock functions and flags. These functions might sleep.
*
* clock_register and clock_unregister() do what they say. Upon return from
* unregister, the clock's methods are not running and will not be called again.
*
* clock_schedule() requests that a registered clock's clock_settime() calls
* happen at the given offset into the second. The default is 0, meaning no
* specific scheduling. To schedule the call as soon after top-of-second as
* possible, specify 1. Each clock has its own schedule, but taskqueue_thread
* is shared by many tasks; the timing of the call is not guaranteed.
*
* Flags:
*
* CLOCKF_SETTIME_NO_TS
* Do not pass a timespec to clock_settime(), the driver obtains its own time
* and applies its own adjustments (this flag implies CLOCKF_SETTIME_NO_ADJ).
*
* CLOCKF_SETTIME_NO_ADJ
* Do not apply utc offset and resolution/accuracy adjustments to the value
* passed to clock_settime(), the driver applies them itself.
*
* CLOCKF_GETTIME_NO_ADJ
* Do not apply utc offset and resolution/accuracy adjustments to the value
* returned from clock_gettime(), the driver has already applied them.
*/
#define CLOCKF_SETTIME_NO_TS 0x00000001
#define CLOCKF_SETTIME_NO_ADJ 0x00000002
#define CLOCKF_GETTIME_NO_ADJ 0x00000004
void clock_register(device_t _clockdev, long _resolution_us);
void clock_register_flags(device_t _clockdev, long _resolution_us, int _flags);
void clock_schedule(device_t clockdev, u_int _offsetns);
void clock_unregister(device_t _clockdev);
/*
* BCD to decimal and decimal to BCD.
*/
#define FROMBCD(x) bcd2bin(x)
#define TOBCD(x) bin2bcd(x)
/* Some handy constants. */
#define SECDAY (24 * 60 * 60)
#define SECYR (SECDAY * 365)
/* Traditional POSIX base year */
#define POSIX_BASE_YEAR 1970
void timespec2fattime(const struct timespec *tsp, int utc, u_int16_t *ddp,
u_int16_t *dtp, u_int8_t *dhp);
void fattime2timespec(unsigned dd, unsigned dt, unsigned dh, int utc,
struct timespec *tsp);
/*
* Print a [bcd_]clocktime or timespec, optionally with fractional seconds. The
* nsdig argument can range from 0-9, and specifies how many decimal digits to
* display for fractional seconds.
*/
void clock_print_bcd(const struct bcd_clocktime *bct, int nsdig);
void clock_print_ct(const struct clocktime *ct, int nsdig);
void clock_print_ts(const struct timespec *ts, int nsdig);
/*
* Debugging helpers for RTC clock drivers. Print a [bcd_]clocktime or
* timespec, only if rtc clock debugging has been enabled. The rw argument is
* one of CLOCK_DBG_READ or CLOCK_DBG_WRITE.
*/
#define CLOCK_DBG_READ 0x01
#define CLOCK_DBG_WRITE 0x02
void clock_dbgprint_bcd(device_t dev, int rw, const struct bcd_clocktime *bct);
void clock_dbgprint_ct(device_t dev, int rw, const struct clocktime *ct);
void clock_dbgprint_err(device_t dev, int rw, int err);
void clock_dbgprint_ts(device_t dev, int rw, const struct timespec *ts);
#endif /* _KERNEL */
#endif /* !_SYS_CLOCK_H_ */