NetBSD/sys/arch/atari/dev/clock.c

586 lines
14 KiB
C

/* $NetBSD: clock.c,v 1.27 2001/07/26 15:05:09 wiz Exp $ */
/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1982, 1990 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.
* 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 7.6 (Berkeley) 5/7/91
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/uio.h>
#include <sys/conf.h>
#include <dev/clock_subr.h>
#include <machine/psl.h>
#include <machine/cpu.h>
#include <machine/iomap.h>
#include <machine/mfp.h>
#include <atari/dev/clockreg.h>
#include <atari/atari/device.h>
#if defined(GPROF) && defined(PROFTIMER)
#include <machine/profile.h>
#endif
/*
* The MFP clock runs at 2457600Hz. We use a {system,stat,prof}clock divider
* of 200. Therefore the timer runs at an effective rate of:
* 2457600/200 = 12288Hz.
*/
#define CLOCK_HZ 12288
/*
* Machine-dependent clock routines.
*
* Inittodr initializes the time of day hardware which provides
* date functions.
*
* Resettodr restores the time of day hardware after a time change.
*/
struct clock_softc {
struct device sc_dev;
int sc_flags;
};
/*
* 'sc_flags' state info. Only used by the rtc-device functions.
*/
#define RTC_OPEN 1
/* {b,c}devsw[] function prototypes for rtc functions */
dev_type_open(rtcopen);
dev_type_close(rtcclose);
dev_type_read(rtcread);
dev_type_write(rtcwrite);
static void clockattach __P((struct device *, struct device *, void *));
static int clockmatch __P((struct device *, struct cfdata *, void *));
struct cfattach clock_ca = {
sizeof(struct clock_softc), clockmatch, clockattach
};
extern struct cfdriver clock_cd;
void statintr __P((struct clockframe));
static u_long gettod __P((void));
static int twodigits __P((char *, int));
static int divisor; /* Systemclock divisor */
/*
* Statistics and profile clock intervals and variances. Variance must
* be a power of 2. Since this gives us an even number, not an odd number,
* we discard one case and compensate. That is, a variance of 64 would
* give us offsets in [0..63]. Instead, we take offsets in [1..63].
* This is symmetric around the point 32, or statvar/2, and thus averages
* to that value (assuming uniform random numbers).
*/
#ifdef STATCLOCK
static int statvar = 32; /* {stat,prof}clock variance */
static int statmin; /* statclock divisor - variance/2 */
static int profmin; /* profclock divisor - variance/2 */
static int clk2min; /* current, from above choices */
#endif
int
clockmatch(pdp, cfp, auxp)
struct device *pdp;
struct cfdata *cfp;
void *auxp;
{
if (!atari_realconfig) {
/*
* Initialize Timer-B in the ST-MFP. This timer is used by
* the 'delay' function below. This timer is setup to be
* continueously counting from 255 back to zero at a
* frequency of 614400Hz. We do this *early* in the
* initialisation process.
*/
MFP->mf_tbcr = 0; /* Stop timer */
MFP->mf_iera &= ~IA_TIMB; /* Disable timer interrupts */
MFP->mf_tbdr = 0;
MFP->mf_tbcr = T_Q004; /* Start timer */
/*
* Initialize the time structure
*/
time.tv_sec = 0;
time.tv_usec = 0;
return 0;
}
if(!strcmp("clock", auxp))
return(1);
return(0);
}
/*
* Start the real-time clock.
*/
void clockattach(pdp, dp, auxp)
struct device *pdp, *dp;
void *auxp;
{
struct clock_softc *sc = (void *)dp;
sc->sc_flags = 0;
/*
* Initialize Timer-A in the ST-MFP. We use a divisor of 200.
* The MFP clock runs at 2457600Hz. Therefore the timer runs
* at an effective rate of: 2457600/200 = 12288Hz. The
* following expression works for 48, 64 or 96 hz.
*/
divisor = CLOCK_HZ/hz;
MFP->mf_tacr = 0; /* Stop timer */
MFP->mf_iera &= ~IA_TIMA; /* Disable timer interrupts */
MFP->mf_tadr = divisor; /* Set divisor */
if (hz != 48 && hz != 64 && hz != 96) { /* XXX */
printf (": illegal value %d for systemclock, reset to %d\n\t",
hz, 64);
hz = 64;
}
printf(": system hz %d timer-A divisor 200/%d\n", hz, divisor);
#ifdef STATCLOCK
if ((stathz == 0) || (stathz > hz) || (CLOCK_HZ % stathz))
stathz = hz;
if ((profhz == 0) || (profhz > (hz << 1)) || (CLOCK_HZ % profhz))
profhz = hz << 1;
MFP->mf_tcdcr &= 0x7; /* Stop timer */
MFP->mf_ierb &= ~IB_TIMC; /* Disable timer inter. */
MFP->mf_tcdr = CLOCK_HZ/stathz; /* Set divisor */
statmin = (CLOCK_HZ/stathz) - (statvar >> 1);
profmin = (CLOCK_HZ/profhz) - (statvar >> 1);
clk2min = statmin;
#endif /* STATCLOCK */
}
void cpu_initclocks()
{
MFP->mf_tacr = T_Q200; /* Start timer */
MFP->mf_ipra = (u_int8_t)~IA_TIMA;/* Clear pending interrupts */
MFP->mf_iera |= IA_TIMA; /* Enable timer interrupts */
MFP->mf_imra |= IA_TIMA; /* ..... */
#ifdef STATCLOCK
MFP->mf_tcdcr = (MFP->mf_tcdcr & 0x7) | (T_Q200<<4); /* Start */
MFP->mf_iprb = (u_int8_t)~IB_TIMC;/* Clear pending interrupts */
MFP->mf_ierb |= IB_TIMC; /* Enable timer interrupts */
MFP->mf_imrb |= IB_TIMC; /* ..... */
#endif /* STATCLOCK */
}
void
setstatclockrate(newhz)
int newhz;
{
#ifdef STATCLOCK
if (newhz == stathz)
clk2min = statmin;
else clk2min = profmin;
#endif /* STATCLOCK */
}
#ifdef STATCLOCK
void
statintr(frame)
struct clockframe frame;
{
register int var, r;
var = statvar - 1;
do {
r = random() & var;
} while(r == 0);
/*
* Note that we are always lagging behind as the new divisor
* value will not be loaded until the next interrupt. This
* shouldn't disturb the median frequency (I think ;-) ) as
* only the value used when switching frequencies is used
* twice. This shouldn't happen very often.
*/
MFP->mf_tcdr = clk2min + r;
statclock(&frame);
}
#endif /* STATCLOCK */
/*
* Returns number of usec since last recorded clock "tick"
* (i.e. clock interrupt).
*/
long
clkread()
{
u_int delta;
u_char ipra, tadr;
/*
* Note: Order is important!
* By reading 'ipra' before 'tadr' and caching the data, I try to avoid
* the situation that very low value in 'tadr' is read (== a big delta)
* while also acccounting for a full 'tick' because the counter went
* through zero during the calculations.
*/
ipra = MFP->mf_ipra; tadr = MFP->mf_tadr;
delta = ((divisor - tadr) * tick) / divisor;
/*
* Account for pending clock interrupts
*/
if(ipra & IA_TIMA)
return(delta + tick);
return(delta);
}
#define TIMB_FREQ 614400
#define TIMB_LIMIT 256
/*
* Wait "n" microseconds.
* Relies on MFP-Timer B counting down from TIMB_LIMIT at TIMB_FREQ Hz.
* Note: timer had better have been programmed before this is first used!
*/
void
delay(n)
int n;
{
int tick, otick;
/*
* Read the counter first, so that the rest of the setup overhead is
* counted.
*/
otick = MFP->mf_tbdr;
/*
* Calculate ((n * TIMER_FREQ) / 1e6) using explicit assembler code so
* we can take advantage of the intermediate 64-bit quantity to prevent
* loss of significance.
*/
n -= 5;
if(n < 0)
return;
{
u_int temp;
__asm __volatile ("mulul %2,%1:%0" : "=d" (n), "=d" (temp)
: "d" (TIMB_FREQ), "d" (n));
__asm __volatile ("divul %1,%2:%0" : "=d" (n)
: "d"(1000000),"d"(temp),"0"(n));
}
while(n > 0) {
tick = MFP->mf_tbdr;
if(tick > otick)
n -= TIMB_LIMIT - (tick - otick);
else n -= otick - tick;
otick = tick;
}
}
#ifdef GPROF
/*
* profclock() is expanded in line in lev6intr() unless profiling kernel.
* Assumes it is called with clock interrupts blocked.
*/
profclock(pc, ps)
caddr_t pc;
int ps;
{
/*
* Came from user mode.
* If this process is being profiled record the tick.
*/
if (USERMODE(ps)) {
if (p->p_stats.p_prof.pr_scale)
addupc(pc, &curproc->p_stats.p_prof, 1);
}
/*
* Came from kernel (supervisor) mode.
* If we are profiling the kernel, record the tick.
*/
else if (profiling < 2) {
register int s = pc - s_lowpc;
if (s < s_textsize)
kcount[s / (HISTFRACTION * sizeof (*kcount))]++;
}
/*
* Kernel profiling was on but has been disabled.
* Mark as no longer profiling kernel and if all profiling done,
* disable the clock.
*/
if (profiling && (profon & PRF_KERNEL)) {
profon &= ~PRF_KERNEL;
if (profon == PRF_NONE)
stopprofclock();
}
}
#endif
/***********************************************************************
* Real Time Clock support *
***********************************************************************/
u_int mc146818_read(rtc, regno)
void *rtc;
u_int regno;
{
((struct rtc *)rtc)->rtc_regno = regno;
return(((struct rtc *)rtc)->rtc_data & 0377);
}
void mc146818_write(rtc, regno, value)
void *rtc;
u_int regno, value;
{
((struct rtc *)rtc)->rtc_regno = regno;
((struct rtc *)rtc)->rtc_data = value;
}
/*
* Initialize the time of day register, assuming the RTC runs in UTC.
* Since we've got the 'rtc' device, this functionality should be removed
* from the kernel. The only problem to be solved before that can happen
* is the possibility of init(1) providing a way (rc.boot?) to set
* the RTC before single-user mode is entered.
*/
void
inittodr(base)
time_t base;
{
/* Battery clock does not store usec's, so forget about it. */
time.tv_sec = gettod();
time.tv_usec = 0;
}
/*
* Function turned into a No-op. Use /dev/rtc to update the RTC.
*/
void
resettodr()
{
return;
}
static u_long
gettod()
{
int sps;
mc_todregs clkregs;
u_int regb;
struct clock_ymdhms dt;
sps = splhigh();
regb = mc146818_read(RTC, MC_REGB);
MC146818_GETTOD(RTC, &clkregs);
splx(sps);
regb &= MC_REGB_24HR|MC_REGB_BINARY;
if (regb != (MC_REGB_24HR|MC_REGB_BINARY)) {
printf("Error: Nonstandard RealTimeClock Configuration -"
" value ignored\n"
" A write to /dev/rtc will correct this.\n");
return(0);
}
if(clkregs[MC_SEC] > 59)
return(0);
if(clkregs[MC_MIN] > 59)
return(0);
if(clkregs[MC_HOUR] > 23)
return(0);
if(range_test(clkregs[MC_DOM], 1, 31))
return(0);
if (range_test(clkregs[MC_MONTH], 1, 12))
return(0);
if(clkregs[MC_YEAR] > 99)
return(0);
dt.dt_year = clkregs[MC_YEAR] + GEMSTARTOFTIME;
dt.dt_mon = clkregs[MC_MONTH];
dt.dt_day = clkregs[MC_DOM];
dt.dt_hour = clkregs[MC_HOUR];
dt.dt_min = clkregs[MC_MIN];
dt.dt_sec = clkregs[MC_SEC];
return(clock_ymdhms_to_secs(&dt));
}
/***********************************************************************
* RTC-device support *
***********************************************************************/
int
rtcopen(dev, flag, mode, p)
dev_t dev;
int flag, mode;
struct proc *p;
{
int unit = minor(dev);
struct clock_softc *sc;
if (unit >= clock_cd.cd_ndevs)
return ENXIO;
sc = clock_cd.cd_devs[unit];
if (!sc)
return ENXIO;
if (sc->sc_flags & RTC_OPEN)
return EBUSY;
sc->sc_flags = RTC_OPEN;
return 0;
}
int
rtcclose(dev, flag, mode, p)
dev_t dev;
int flag;
int mode;
struct proc *p;
{
int unit = minor(dev);
struct clock_softc *sc = clock_cd.cd_devs[unit];
sc->sc_flags = 0;
return 0;
}
int
rtcread(dev, uio, flags)
dev_t dev;
struct uio *uio;
int flags;
{
struct clock_softc *sc;
mc_todregs clkregs;
int s, length;
char buffer[16];
sc = clock_cd.cd_devs[minor(dev)];
s = splhigh();
MC146818_GETTOD(RTC, &clkregs);
splx(s);
sprintf(buffer, "%4d%02d%02d%02d%02d.%02d\n",
clkregs[MC_YEAR] + GEMSTARTOFTIME,
clkregs[MC_MONTH], clkregs[MC_DOM],
clkregs[MC_HOUR], clkregs[MC_MIN], clkregs[MC_SEC]);
if (uio->uio_offset > strlen(buffer))
return 0;
length = strlen(buffer) - uio->uio_offset;
if (length > uio->uio_resid)
length = uio->uio_resid;
return(uiomove((caddr_t)buffer, length, uio));
}
static int
twodigits(buffer, pos)
char *buffer;
int pos;
{
int result = 0;
if (buffer[pos] >= '0' && buffer[pos] <= '9')
result = (buffer[pos] - '0') * 10;
if (buffer[pos+1] >= '0' && buffer[pos+1] <= '9')
result += (buffer[pos+1] - '0');
return(result);
}
int
rtcwrite(dev, uio, flags)
dev_t dev;
struct uio *uio;
int flags;
{
mc_todregs clkregs;
int s, length, error;
char buffer[16];
/*
* We require atomic updates!
*/
length = uio->uio_resid;
if (uio->uio_offset || (length != sizeof(buffer)
&& length != sizeof(buffer - 1)))
return(EINVAL);
if ((error = uiomove((caddr_t)buffer, sizeof(buffer), uio)))
return(error);
if (length == sizeof(buffer) && buffer[sizeof(buffer) - 1] != '\n')
return(EINVAL);
s = splclock();
mc146818_write(RTC, MC_REGB,
mc146818_read(RTC, MC_REGB) | MC_REGB_24HR | MC_REGB_BINARY);
MC146818_GETTOD(RTC, &clkregs);
splx(s);
clkregs[MC_SEC] = twodigits(buffer, 13);
clkregs[MC_MIN] = twodigits(buffer, 10);
clkregs[MC_HOUR] = twodigits(buffer, 8);
clkregs[MC_DOM] = twodigits(buffer, 6);
clkregs[MC_MONTH] = twodigits(buffer, 4);
s = twodigits(buffer, 0) * 100 + twodigits(buffer, 2);
clkregs[MC_YEAR] = s - GEMSTARTOFTIME;
s = splclock();
MC146818_PUTTOD(RTC, &clkregs);
splx(s);
return(0);
}