NetBSD/sys/arch/atari/dev/clock.c
1996-10-13 04:10:34 +00:00

480 lines
12 KiB
C

/* $NetBSD: clock.c,v 1.13 1996/10/13 04:10:51 christos 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 <machine/psl.h>
#include <machine/cpu.h>
#include <machine/iomap.h>
#include <machine/mfp.h>
#include <atari/dev/clockreg.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.
*/
int clockmatch __P((struct device *, void *, void *));
void clockattach __P((struct device *, struct device *, void *));
struct cfattach clock_ca = {
sizeof(struct device), clockmatch, clockattach
};
struct cfdriver clock_cd = {
NULL, "clock", DV_DULL, NULL, 0
};
void statintr __P((struct clockframe *));
static u_long gettod __P((void));
static int settod __P((u_long));
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 symetric 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 choises */
#endif
int
clockmatch(pdp, match, auxp)
struct device *pdp;
void *match, *auxp;
{
if(!strcmp("clock", auxp))
return(1);
return(0);
}
/*
* Start the real-time clock.
*/
void clockattach(pdp, dp, auxp)
struct device *pdp, *dp;
void *auxp;
{
/*
* 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 */
/*
* Initialize Timer-B in the ST-MFP. This timer is used by the 'delay'
* function below. This time is setup to be continueously counting from
* 255 back to zero at a frequency of 614400Hz.
*/
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 */
}
void cpu_initclocks()
{
MFP->mf_tacr = T_Q200; /* Start timer */
MFP->mf_ipra &= ~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 &= ~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)
register 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;
delta = ((divisor - MFP->mf_tadr) * tick) / divisor;
/*
* Account for pending clock interrupts
*/
if(MFP->mf_iera & 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));
__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, based on the time base which is, e.g.
* from a filesystem.
*/
void
inittodr(base)
time_t base;
{
u_long timbuf = base; /* assume no battery clock exists */
timbuf = gettod();
if(timbuf < base) {
printf("WARNING: bad date in battery clock\n");
timbuf = base;
}
/* Battery clock does not store usec's, so forget about it. */
time.tv_sec = timbuf;
time.tv_usec = 0;
}
void
resettodr()
{
if(settod(time.tv_sec) == 1)
return;
printf("Cannot set battery backed clock\n");
}
static char dmsize[12] =
{
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
static char ldmsize[12] =
{
31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
static u_long
gettod()
{
int i, sps;
u_long new_time = 0;
char *msize;
mc_todregs clkregs;
sps = splhigh();
MC146818_GETTOD(RTC, &clkregs);
splx(sps);
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] > (2000 - GEMSTARTOFTIME))
return(0);
clkregs[MC_YEAR] += GEMSTARTOFTIME;
for(i = BSDSTARTOFTIME; i < clkregs[MC_YEAR]; i++) {
if(is_leap(i))
new_time += 366;
else new_time += 365;
}
msize = is_leap(clkregs[MC_YEAR]) ? ldmsize : dmsize;
for(i = 0; i < (clkregs[MC_MONTH] - 1); i++)
new_time += msize[i];
new_time += clkregs[MC_DOM] - 1;
new_time *= SECS_DAY;
new_time += (clkregs[MC_HOUR] * 3600) + (clkregs[MC_MIN] * 60);
return(new_time + clkregs[MC_SEC]);
}
static int
settod(newtime)
u_long newtime;
{
register long days, rem, year;
register char *ml;
int sps, sec, min, hour, month;
mc_todregs clkregs;
/* Number of days since Jan. 1 'BSDSTARTOFTIME' */
days = newtime / SECS_DAY;
rem = newtime % SECS_DAY;
/*
* Calculate sec, min, hour
*/
hour = rem / SECS_HOUR;
rem %= SECS_HOUR;
min = rem / 60;
sec = rem % 60;
/*
* Figure out the year. Day in year is left in 'days'.
*/
year = BSDSTARTOFTIME;
while(days >= (rem = is_leap(year) ? 366 : 365)) {
++year;
days -= rem;
}
/*
* Determine the month
*/
ml = is_leap(year) ? ldmsize : dmsize;
for(month = 0; days >= ml[month]; ++month)
days -= ml[month];
/*
* Now that everything is calculated, program the RTC
*/
mc146818_write(RTC, MC_REGA, MC_BASE_32_KHz);
mc146818_write(RTC, MC_REGB, MC_REGB_24HR | MC_REGB_BINARY);
sps = splhigh();
MC146818_GETTOD(RTC, &clkregs);
clkregs[MC_SEC] = sec;
clkregs[MC_MIN] = min;
clkregs[MC_HOUR] = hour;
clkregs[MC_DOM] = days+1;
clkregs[MC_MONTH] = month+1;
clkregs[MC_YEAR] = year - GEMSTARTOFTIME;
MC146818_PUTTOD(RTC, &clkregs);
splx(sps);
return(1);
}