FreeBSD-5.3/sys/kern/subr_clock.c
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1982, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* from: Utah $Hdr: clock.c 1.18 91/01/21$
* from: @(#)clock.c 8.2 (Berkeley) 1/12/94
* from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp
* and
* from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04
*/
/*
* Helpers for time-of-day clocks. This is useful for architectures that need
* support multiple models of such clocks, and generally serves to make the
* code more machine-independent.
* If the clock in question can also be used as a time counter, the driver
* needs to initiate this.
* This code is not yet used by all architectures.
*/
/*
* Generic routines to convert between a POSIX date
* (seconds since 1/1/1970) and yr/mo/day/hr/min/sec
* Derived from NetBSD arch/hp300/hp300/clock.c
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/kern/subr_clock.c,v 1.5 2004/04/05 21:03:35 imp Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/clock.h>
#include <sys/sysctl.h>
#include <sys/timetc.h>
/* XXX: for the CPU_* sysctl OID constants. */
#include <machine/cpu.h>
#include "clock_if.h"
static __inline int leapyear(int year);
static int sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS);
#define FEBRUARY 2
#define days_in_year(y) (leapyear(y) ? 366 : 365)
#define days_in_month(y, m) \
(month_days[(m) - 1] + (m == FEBRUARY ? leapyear(y) : 0))
/* Day of week. Days are counted from 1/1/1970, which was a Thursday */
#define day_of_week(days) (((days) + 4) % 7)
static const int month_days[12] = {
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
static device_t clock_dev = NULL;
static long clock_res;
int adjkerntz; /* local offset from GMT in seconds */
int disable_rtc_set; /* disable resettodr() if != 0 */
int wall_cmos_clock; /* wall CMOS clock assumed if != 0 */
/*
* These have traditionally been in machdep, but should probably be moved to
* kern.
*/
SYSCTL_PROC(_machdep, CPU_ADJKERNTZ, adjkerntz, CTLTYPE_INT|CTLFLAG_RW,
&adjkerntz, 0, sysctl_machdep_adjkerntz, "I", "");
SYSCTL_INT(_machdep, CPU_DISRTCSET, disable_rtc_set,
CTLFLAG_RW, &disable_rtc_set, 0, "");
SYSCTL_INT(_machdep, CPU_WALLCLOCK, wall_cmos_clock,
CTLFLAG_RW, &wall_cmos_clock, 0, "");
static int
sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS)
{
int error;
error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2,
req);
if (!error && req->newptr)
resettodr();
return (error);
}
/*
* This inline avoids some unnecessary modulo operations
* as compared with the usual macro:
* ( ((year % 4) == 0 &&
* (year % 100) != 0) ||
* ((year % 400) == 0) )
* It is otherwise equivalent.
*/
static __inline int
leapyear(int year)
{
int rv = 0;
if ((year & 3) == 0) {
rv = 1;
if ((year % 100) == 0) {
rv = 0;
if ((year % 400) == 0)
rv = 1;
}
}
return (rv);
}
int
clock_ct_to_ts(struct clocktime *ct, struct timespec *ts)
{
time_t secs;
int i, year, days;
year = ct->year;
/* Sanity checks. */
if (ct->mon < 1 || ct->mon > 12 || ct->day < 1 ||
ct->day > days_in_month(year, ct->mon) ||
ct->hour > 23 || ct->min > 59 || ct->sec > 59 ||
ct->year > 2037) /* time_t overflow */
return (EINVAL);
/*
* Compute days since start of time
* First from years, then from months.
*/
days = 0;
for (i = POSIX_BASE_YEAR; i < year; i++)
days += days_in_year(i);
/* Months */
for (i = 1; i < ct->mon; i++)
days += days_in_month(year, i);
days += (ct->day - 1);
/* Another sanity check. */
if (ct->dow != -1 && ct->dow != day_of_week(days))
return (EINVAL);
/* Add hours, minutes, seconds. */
secs = ((days * 24 + ct->hour) * 60 + ct->min) * 60 + ct->sec;
ts->tv_sec = secs;
ts->tv_nsec = ct->nsec;
return (0);
}
void
clock_ts_to_ct(struct timespec *ts, struct clocktime *ct)
{
int i, year, days;
time_t rsec; /* remainder seconds */
time_t secs;
secs = ts->tv_sec;
days = secs / SECDAY;
rsec = secs % SECDAY;
ct->dow = day_of_week(days);
/* Subtract out whole years, counting them in i. */
for (year = POSIX_BASE_YEAR; days >= days_in_year(year); year++)
days -= days_in_year(year);
ct->year = year;
/* Subtract out whole months, counting them in i. */
for (i = 1; days >= days_in_month(year, i); i++)
days -= days_in_month(year, i);
ct->mon = i;
/* Days are what is left over (+1) from all that. */
ct->day = days + 1;
/* Hours, minutes, seconds are easy */
ct->hour = rsec / 3600;
rsec = rsec % 3600;
ct->min = rsec / 60;
rsec = rsec % 60;
ct->sec = rsec;
ct->nsec = ts->tv_nsec;
}
void
clock_register(device_t dev, long res)
{
if (clock_dev != NULL) {
if (clock_res > res) {
if (bootverbose) {
device_printf(dev, "not installed as "
"time-of-day clock: clock %s has higher "
"resolution\n", device_get_name(clock_dev));
}
return;
} else {
if (bootverbose) {
device_printf(clock_dev, "removed as "
"time-of-day clock: clock %s has higher "
"resolution\n", device_get_name(dev));
}
}
}
clock_dev = dev;
clock_res = res;
if (bootverbose) {
device_printf(dev, "registered as a time-of-day clock "
"(resolution %ldus)\n", res);
}
}
/*
* inittodr and settodr derived from the i386 versions written
* by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>, reintroduced and
* updated by Chris Stenton <chris@gnome.co.uk> 8/10/94
*/
/*
* Initialize the time of day register, based on the time base which is, e.g.
* from a filesystem.
*/
void
inittodr(time_t base)
{
struct timespec diff, ref, ts;
int error;
if (base) {
ref.tv_sec = base;
ref.tv_nsec = 0;
tc_setclock(&ref);
}
if (clock_dev == NULL) {
printf("warning: no time-of-day clock registered, system time "
"will not be set accurately\n");
return;
}
error = CLOCK_GETTIME(clock_dev, &ts);
if (error != 0 && error != EINVAL) {
printf("warning: clock_gettime failed (%d), the system time "
"will not be set accurately\n", error);
return;
}
if (error == EINVAL || ts.tv_sec < 0) {
printf("Invalid time in real time clock.\n");
printf("Check and reset the date immediately!\n");
}
ts.tv_sec += tz_minuteswest * 60 +
(wall_cmos_clock ? adjkerntz : 0);
if (timespeccmp(&ref, &ts, >)) {
diff = ref;
timespecsub(&ref, &ts);
} else {
diff = ts;
timespecsub(&diff, &ref);
}
if (ts.tv_sec >= 2) {
/* badly off, adjust it */
tc_setclock(&ts);
}
}
/*
* Write system time back to RTC
*/
void
resettodr()
{
struct timespec ts;
int error;
if (disable_rtc_set || clock_dev == NULL)
return;
getnanotime(&ts);
ts.tv_sec -= tz_minuteswest * 60 + (wall_cmos_clock ? adjkerntz : 0);
if ((error = CLOCK_SETTIME(clock_dev, &ts)) != 0) {
printf("warning: clock_settime failed (%d), time-of-day clock "
"not adjusted to system time\n", error);
return;
}
}