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freebsd/sys/dev/dec/mcclock.c
Andrew Gallatin cd4e23cead Introduce a boot environment variable (clock_compat_osf1) which can
be set to 1 to make FreeBSD and Tru64 coexist peacefully on a dual
boot system and not clobber each other's year in the TOY clock.
(Tru64 uses an offset 52 years higher than one would expect)

Obtained from: NetBSD
MFC After: 1 week
2001-11-03 17:22:50 +00:00

140 lines
2.9 KiB
C

/* $FreeBSD$ */
/* $NetBSD: mcclock.c,v 1.11 1998/04/19 07:50:25 jonathan Exp $ */
/*
* Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Chris G. Demetriou
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <machine/clockvar.h>
#include <dev/dec/mcclockvar.h>
#include <dev/dec/mc146818reg.h>
/*
* XXX rate is machine-dependent.
*/
#ifdef __alpha__
#define MC_DEFAULTRATE MC_RATE_1024_Hz
#endif
#ifdef __pmax__
#define MC_DEFAULTRATE MC_RATE_256_Hz
#endif
void
mcclock_attach(device_t dev)
{
/* Turn interrupts off, just in case. */
MCCLOCK_WRITE(dev, MC_REGB, MC_REGB_BINARY | MC_REGB_24HR);
clockattach(dev);
}
void
mcclock_init(device_t dev)
{
MCCLOCK_WRITE(dev, MC_REGA, MC_BASE_32_KHz | MC_DEFAULTRATE);
MCCLOCK_WRITE(dev, MC_REGB,
MC_REGB_PIE | MC_REGB_SQWE | MC_REGB_BINARY | MC_REGB_24HR);
}
/*
* Get the time of day, based on the clock's value and/or the base value.
*/
void
mcclock_get(device_t dev, time_t base, struct clocktime *ct)
{
mc_todregs regs;
int s;
s = splclock();
MC146818_GETTOD(dev, &regs)
splx(s);
ct->sec = regs[MC_SEC];
ct->min = regs[MC_MIN];
ct->hour = regs[MC_HOUR];
ct->dow = regs[MC_DOW];
ct->day = regs[MC_DOM];
ct->mon = regs[MC_MONTH];
ct->year = regs[MC_YEAR];
}
/*
* Reset the TODR based on the time value.
*/
void
mcclock_set(device_t dev, struct clocktime *ct)
{
mc_todregs regs;
int s;
s = splclock();
MC146818_GETTOD(dev, &regs);
splx(s);
regs[MC_SEC] = ct->sec;
regs[MC_MIN] = ct->min;
regs[MC_HOUR] = ct->hour;
regs[MC_DOW] = ct->dow;
regs[MC_DOM] = ct->day;
regs[MC_MONTH] = ct->mon;
regs[MC_YEAR] = ct->year;
s = splclock();
MC146818_PUTTOD(dev, &regs);
splx(s);
}
int
mcclock_getsecs(device_t dev, int *secp)
{
int timeout = 100000000;
int sec;
int s;
s = splclock();
for (;;) {
if (!(MCCLOCK_READ(dev, MC_REGA) & MC_REGA_UIP)) {
sec = MCCLOCK_READ(dev, MC_SEC);
break;
}
if (--timeout == 0)
goto fail;
}
splx(s);
*secp = sec;
return 0;
fail:
splx(s);
return ETIMEDOUT;
}