4.4BSD/usr/src/sys/pmax/pmax/clock.c
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1992, 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 and Ralph Campbell.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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 $Hdr: clock.c 1.18 91/01/21$
*
* @(#)clock.c 8.1 (Berkeley) 6/10/93
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <machine/machConst.h>
#include <pmax/pmax/clockreg.h>
/*
* Machine-dependent clock routines.
*
* Startrtclock restarts the real-time clock, which provides
* hardclock interrupts to kern_clock.c.
*
* Inittodr initializes the time of day hardware which provides
* date functions. Its primary function is to use some file
* system information in case the hardare clock lost state.
*
* Resettodr restores the time of day hardware after a time change.
*/
volatile struct chiptime *Mach_clock_addr;
/*
* Start the real-time and statistics clocks. Leave stathz 0 since there
* are no other timers available.
*/
cpu_initclocks()
{
register volatile struct chiptime *c;
extern int tickadj;
tick = 15625; /* number of micro-seconds between interrupts */
hz = 1000000 / 15625; /* 64 Hz */
tickadj = 240000 / (60000000 / 15625);
c = Mach_clock_addr;
c->rega = REGA_TIME_BASE | SELECTED_RATE;
c->regb = REGB_PER_INT_ENA | REGB_DATA_MODE | REGB_HOURS_FORMAT;
}
/*
* We assume newhz is either stathz or profhz, and that neither will
* change after being set up above. Could recalculate intervals here
* but that would be a drag.
*/
void
setstatclockrate(newhz)
int newhz;
{
}
/*
* This code is defunct after 2099.
* Will Unix still be here then??
*/
static short dayyr[12] = {
0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
};
/*
* Initialze the time of day register, based on the time base which is, e.g.
* from a filesystem. Base provides the time to within six months,
* and the time of year clock (if any) provides the rest.
*/
void
inittodr(base)
time_t base;
{
register volatile struct chiptime *c;
register int days, yr;
int sec, min, hour, day, mon, year;
long deltat;
int badbase, s;
if (base < 5*SECYR) {
printf("WARNING: preposterous time in file system");
/* read the system clock anyway */
base = 6*SECYR + 186*SECDAY + SECDAY/2;
badbase = 1;
} else
badbase = 0;
c = Mach_clock_addr;
/* don't read clock registers while they are being updated */
s = splclock();
while ((c->rega & REGA_UIP) == 1)
;
sec = c->sec;
min = c->min;
hour = c->hour;
day = c->day;
mon = c->mon;
year = c->year + 20; /* must be multiple of 4 because chip knows leap */
splx(s);
/* simple sanity checks */
if (year < 70 || mon < 1 || mon > 12 || day < 1 || day > 31 ||
hour > 23 || min > 59 || sec > 59) {
/*
* Believe the time in the file system for lack of
* anything better, resetting the TODR.
*/
time.tv_sec = base;
if (!badbase) {
printf("WARNING: preposterous clock chip time\n");
resettodr();
}
goto bad;
}
days = 0;
for (yr = 70; yr < year; yr++)
days += LEAPYEAR(yr) ? 366 : 365;
days += dayyr[mon - 1] + day - 1;
if (LEAPYEAR(yr) && mon > 2)
days++;
/* now have days since Jan 1, 1970; the rest is easy... */
time.tv_sec = days * SECDAY + hour * 3600 + min * 60 + sec;
if (!badbase) {
/*
* See if we gained/lost two or more days;
* if so, assume something is amiss.
*/
deltat = time.tv_sec - base;
if (deltat < 0)
deltat = -deltat;
if (deltat < 2 * SECDAY)
return;
printf("WARNING: clock %s %d days",
time.tv_sec < base ? "lost" : "gained", deltat / SECDAY);
}
bad:
printf(" -- CHECK AND RESET THE DATE!\n");
}
/*
* Reset the TODR based on the time value; used when the TODR
* has a preposterous value and also when the time is reset
* by the stime system call. Also called when the TODR goes past
* TODRZERO + 100*(SECYEAR+2*SECDAY) (e.g. on Jan 2 just after midnight)
* to wrap the TODR around.
*/
resettodr()
{
register volatile struct chiptime *c;
register int t, t2;
int sec, min, hour, day, mon, year;
int s;
/* compute the year */
t2 = time.tv_sec / SECDAY;
year = 69;
while (t2 >= 0) { /* whittle off years */
t = t2;
year++;
t2 -= LEAPYEAR(year) ? 366 : 365;
}
/* t = month + day; separate */
t2 = LEAPYEAR(year);
for (mon = 1; mon < 12; mon++)
if (t < dayyr[mon] + (t2 && mon > 1))
break;
day = t - dayyr[mon - 1] + 1;
if (t2 && mon > 2)
day--;
/* the rest is easy */
t = time.tv_sec % SECDAY;
hour = t / 3600;
t %= 3600;
min = t / 60;
sec = t % 60;
c = Mach_clock_addr;
s = splclock();
t = c->regb;
c->regb = t | REGB_SET_TIME;
MachEmptyWriteBuffer();
c->sec = sec;
c->min = min;
c->hour = hour;
c->day = day;
c->mon = mon;
c->year = year - 20; /* must be multiple of 4 because chip knows leap */
c->regb = t;
MachEmptyWriteBuffer();
splx(s);
}