freebsd-skq/sys/i386/isa/clock.c
1994-10-04 13:59:44 +00:00

571 lines
14 KiB
C

/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz and Don Ahn.
*
* 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: @(#)clock.c 7.2 (Berkeley) 5/12/91
* $Id: clock.c,v 1.22 1994/09/29 08:24:45 sos Exp $
*/
/*
* inittodr, settodr and support routines written
* by Christoph Robitschko <chmr@edvz.tu-graz.ac.at>
*
* reintroduced and updated by Chris Stenton <chris@gnome.co.uk> 8/10/94
*/
/*
* Primitive clock interrupt routines.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <machine/frame.h>
#include <i386/isa/icu.h>
#include <i386/isa/isa.h>
#include <i386/isa/rtc.h>
#include <i386/isa/timerreg.h>
/*
* 32-bit time_t's can't reach leap years before 1904 or after 2036, so we
* can use a simple formula for leap years.
*/
#define LEAPYEAR(y) ((u_int)(y) % 4 == 0)
#define DAYSPERYEAR (31+28+31+30+31+30+31+31+30+31+30+31)
/* X-tals being what they are, it's nice to be able to fudge this one... */
/* Note, the name changed here from XTALSPEED to TIMER_FREQ rgrimes 4/26/93 */
#ifndef TIMER_FREQ
#define TIMER_FREQ 1193182 /* XXX - should be in isa.h */
#endif
#define TIMER_DIV(x) ((TIMER_FREQ+(x)/2)/(x))
static int beeping;
int timer0_divisor = TIMER_DIV(100); /* XXX should be hz */
u_int timer0_prescale;
int adjkerntz = 0; /* offset from CMOS clock */
static char timer0_state = 0, timer2_state = 0;
static char timer0_reprogram = 0;
static void (*timer_func)() = hardclock;
static void (*new_function)();
static u_int new_rate;
static u_int hardclock_divisor;
static const u_char daysinmonth[] = {31,28,31,30,31,30,31,31,30,31,30,31};
static u_char rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
#ifdef I586_CPU
int pentium_mhz = 0;
#endif
#if 0
void
clkintr(struct clockframe frame)
{
hardclock(&frame);
}
#else
void
clkintr(struct clockframe frame)
{
timer_func(&frame);
switch (timer0_state) {
case 0:
break;
case 1:
if ((timer0_prescale+=timer0_divisor) >= hardclock_divisor) {
hardclock(&frame);
timer0_prescale = 0;
}
break;
case 2:
disable_intr();
outb(TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT);
outb(TIMER_CNTR0, TIMER_DIV(new_rate)%256);
outb(TIMER_CNTR0, TIMER_DIV(new_rate)/256);
enable_intr();
timer0_divisor = TIMER_DIV(new_rate);
timer0_prescale = 0;
timer_func = new_function;
timer0_state = 1;
break;
case 3:
if ((timer0_prescale+=timer0_divisor) >= hardclock_divisor) {
hardclock(&frame);
disable_intr();
outb(TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT);
outb(TIMER_CNTR0, TIMER_DIV(hz)%256);
outb(TIMER_CNTR0, TIMER_DIV(hz)/256);
enable_intr();
timer0_divisor = TIMER_DIV(hz);
timer0_prescale = 0;
timer_func = hardclock;;
timer0_state = 0;
}
break;
}
}
#endif
int
acquire_timer0(int rate, void (*function)() )
{
if (timer0_state || !function)
return -1;
new_function = function;
new_rate = rate;
timer0_state = 2;
return 0;
}
int
acquire_timer2(int mode)
{
if (timer2_state)
return -1;
timer2_state = 1;
outb(TIMER_MODE, TIMER_SEL2 | (mode &0x3f));
return 0;
}
int
release_timer0()
{
if (!timer0_state)
return -1;
timer0_state = 3;
return 0;
}
int
release_timer2()
{
if (!timer2_state)
return -1;
timer2_state = 0;
outb(TIMER_MODE, TIMER_SEL2|TIMER_SQWAVE|TIMER_16BIT);
return 0;
}
/*
* This routine receives statistical clock interrupts from the RTC.
* As explained above, these occur at 128 interrupts per second.
* When profiling, we receive interrupts at a rate of 1024 Hz.
*
* This does not actually add as much overhead as it sounds, because
* when the statistical clock is active, the hardclock driver no longer
* needs to keep (inaccurate) statistics on its own. This decouples
* statistics gathering from scheduling interrupts.
*
* The RTC chip requires that we read status register C (RTC_INTR)
* to acknowledge an interrupt, before it will generate the next one.
*/
void
rtcintr(struct clockframe frame)
{
u_char stat;
stat = rtcin(RTC_INTR);
if(stat & RTCIR_PERIOD) {
statclock(&frame);
}
}
#ifdef DEBUG
void
printrtc(void)
{
outb(IO_RTC, RTC_STATUSA);
printf("RTC status A = %x", inb(IO_RTC+1));
outb(IO_RTC, RTC_STATUSB);
printf(", B = %x", inb(IO_RTC+1));
outb(IO_RTC, RTC_INTR);
printf(", C = %x\n", inb(IO_RTC+1));
}
#endif
static int
getit()
{
int high, low;
disable_intr();
/* select timer0 and latch counter value */
outb(TIMER_MODE, TIMER_SEL0);
low = inb(TIMER_CNTR0);
high = inb(TIMER_CNTR0);
enable_intr();
return ((high << 8) | low);
}
#ifdef I586_CPU
static long long cycles_per_sec = 0;
/*
* Figure out how fast the cyclecounter runs. This must be run with
* clock interrupts disabled, but with the timer/counter programmed
* and running.
*/
void
calibrate_cyclecounter(void)
{
volatile long edx, eax, lasteax, lastedx;
__asm __volatile(".byte 0x0f, 0x31" : "=a"(lasteax), "=d"(lastedx) : );
DELAY(1000000);
__asm __volatile(".byte 0x0f, 0x31" : "=a"(eax), "=d"(edx) : );
/*
* This assumes that you will never have a clock rate higher
* than 4GHz, probably a good assumption.
*/
cycles_per_sec = (long long)edx + eax;
cycles_per_sec -= (long long)lastedx + lasteax;
pentium_mhz = ((long)cycles_per_sec + 500000) / 1000000; /* round up */
}
#endif
/*
* Wait "n" microseconds.
* Relies on timer 1 counting down from (TIMER_FREQ / hz)
* Note: timer had better have been programmed before this is first used!
*/
void
DELAY(int n)
{
int prev_tick, tick, ticks_left, sec, usec;
#ifdef DELAYDEBUG
int getit_calls = 1;
int n1;
static int state = 0;
if (state == 0) {
state = 1;
for (n1 = 1; n1 <= 10000000; n1 *= 10)
DELAY(n1);
state = 2;
}
if (state == 1)
printf("DELAY(%d)...", n);
#endif
/*
* Read the counter first, so that the rest of the setup overhead is
* counted. Guess the initial overhead is 20 usec (on most systems it
* takes about 1.5 usec for each of the i/o's in getit(). The loop
* takes about 6 usec on a 486/33 and 13 usec on a 386/20. The
* multiplications and divisions to scale the count take a while).
*/
prev_tick = getit(0, 0);
n -= 20;
/*
* Calculate (n * (TIMER_FREQ / 1e6)) without using floating point
* and without any avoidable overflows.
*/
sec = n / 1000000;
usec = n - sec * 1000000;
ticks_left = sec * TIMER_FREQ
+ usec * (TIMER_FREQ / 1000000)
+ usec * ((TIMER_FREQ % 1000000) / 1000) / 1000
+ usec * (TIMER_FREQ % 1000) / 1000000;
while (ticks_left > 0) {
tick = getit(0, 0);
#ifdef DELAYDEBUG
++getit_calls;
#endif
if (tick > prev_tick)
ticks_left -= prev_tick - (tick - timer0_divisor);
else
ticks_left -= prev_tick - tick;
prev_tick = tick;
}
#ifdef DELAYDEBUG
if (state == 1)
printf(" %d calls to getit() at %d usec each\n",
getit_calls, (n + 5) / getit_calls);
#endif
}
static void
sysbeepstop(void *chan)
{
outb(IO_PPI, inb(IO_PPI)&0xFC); /* disable counter2 output to speaker */
release_timer2();
beeping = 0;
}
int
sysbeep(int pitch, int period)
{
if (acquire_timer2(TIMER_SQWAVE|TIMER_16BIT))
return -1;
disable_intr();
outb(TIMER_CNTR2, pitch);
outb(TIMER_CNTR2, (pitch>>8));
enable_intr();
if (!beeping) {
outb(IO_PPI, inb(IO_PPI) | 3); /* enable counter2 output to speaker */
beeping = period;
timeout(sysbeepstop, (void *)NULL, period);
}
return 0;
}
/*
* RTC support routines
*/
static int
bcd2int(int bcd)
{
return(bcd/16 * 10 + bcd%16);
}
static int
int2bcd(int dez)
{
return(dez/10 * 16 + dez%10);
}
static void
writertc(int port, int val)
{
outb(IO_RTC, port);
outb(IO_RTC+1, val);
}
static int
readrtc(int port)
{
return(bcd2int(rtcin(port)));
}
void
startrtclock()
{
int s;
/* initialize 8253 clock */
outb(TIMER_MODE, TIMER_SEL0|TIMER_RATEGEN|TIMER_16BIT);
/* Correct rounding will buy us a better precision in timekeeping */
outb (IO_TIMER1, TIMER_DIV(hz)%256);
outb (IO_TIMER1, TIMER_DIV(hz)/256);
timer0_divisor = hardclock_divisor = TIMER_DIV(hz);
/* initialize brain-dead battery powered clock */
outb (IO_RTC, RTC_STATUSA);
outb (IO_RTC+1, rtc_statusa);
outb (IO_RTC, RTC_STATUSB);
outb (IO_RTC+1, RTCSB_24HR);
outb (IO_RTC, RTC_DIAG);
if (s = inb (IO_RTC+1))
printf("RTC BIOS diagnostic error %b\n", s, RTCDG_BITS);
writertc(RTC_DIAG, 0);
}
/*
* Initialize the time of day register, based on the time base which is, e.g.
* from a filesystem.
*/
void
inittodr(time_t base)
{
unsigned long sec, days;
int yd;
int year, month;
int y, m, s;
s = splclock();
time.tv_sec = base;
time.tv_usec = 0;
splx(s);
/* Look if we have a RTC present and the time is valid */
if (rtcin(RTC_STATUSD) != RTCSD_PWR)
goto wrong_time;
/* wait for time update to complete */
/* If RTCSA_TUP is zero, we have at least 244us before next update */
while (rtcin(RTC_STATUSA) & RTCSA_TUP);
days = 0;
#ifdef USE_RTC_CENTURY
year = readrtc(RTC_YEAR) + readrtc(RTC_CENTURY) * 100;
#else
year = readrtc(RTC_YEAR) + 1900;
if (year < 1970)
year += 100;
#endif
if (year < 1970)
goto wrong_time;
month = readrtc(RTC_MONTH);
for (m = 1; m < month; m++)
days += daysinmonth[m-1];
if ((month > 2) && LEAPYEAR(year))
days ++;
days += readrtc(RTC_DAY) - 1;
yd = days;
for (y = 1970; y < year; y++)
days += DAYSPERYEAR + LEAPYEAR(y);
sec = ((( days * 24 +
readrtc(RTC_HRS)) * 60 +
readrtc(RTC_MIN)) * 60 +
readrtc(RTC_SEC));
/* sec now contains the number of seconds, since Jan 1 1970,
in the local time zone */
sec += tz.tz_minuteswest * 60;
s = splclock();
time.tv_sec = sec;
splx(s);
return;
wrong_time:
printf("Invalid time in real time clock.\n");
printf("Check and reset the date immediately!\n");
}
/*
* Write system time back to RTC
*/
void resettodr()
{
unsigned long tm;
int y, m, fd, r, s;
s = splclock();
tm = time.tv_sec;
splx(s);
/* First, disable clock updates */
writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR);
/* Calculate local time to put in CMOS */
tm -= tz.tz_minuteswest * 60 + adjkerntz;
writertc(RTC_SEC, int2bcd(tm%60)); tm /= 60; /* Write back Seconds */
writertc(RTC_MIN, int2bcd(tm%60)); tm /= 60; /* Write back Minutes */
writertc(RTC_HRS, int2bcd(tm%24)); tm /= 24; /* Write back Hours */
/* We have now the days since 01-01-1970 in tm */
writertc(RTC_WDAY, (tm+4)%7); /* Write back Weekday */
for (y=1970;; y++)
if ((tm - DAYSPERYEAR - LEAPYEAR(y)) > tm)
break;
else
tm -= DAYSPERYEAR + LEAPYEAR(y);
/* Now we have the years in y and the day-of-the-year in tm */
writertc(RTC_YEAR, int2bcd(y%100)); /* Write back Year */
#ifdef USE_RTC_CENTURY
writertc(RTC_CENTURY, int2bcd(y/100)); /* ... and Century */
#endif
if (LEAPYEAR(y) && (tm >= 31+29))
tm--; /* Subtract Feb-29 */
for (m=1;; m++)
if (tm - daysinmonth[m-1] > tm)
break;
else
tm -= daysinmonth[m-1];
writertc(RTC_MONTH, int2bcd(m)); /* Write back Month */
writertc(RTC_DAY, int2bcd(tm+1)); /* Write back Day */
/* enable time updates */
writertc(RTC_STATUSB, RTCSB_PINTR | RTCSB_24HR);
}
#ifdef garbage
/*
* Initialze the time of day register, based on the time base which is, e.g.
* from a filesystem.
*/
test_inittodr(time_t base)
{
outb(IO_RTC,9); /* year */
printf("%d ",bcd(inb(IO_RTC+1)));
outb(IO_RTC,8); /* month */
printf("%d ",bcd(inb(IO_RTC+1)));
outb(IO_RTC,7); /* day */
printf("%d ",bcd(inb(IO_RTC+1)));
outb(IO_RTC,4); /* hour */
printf("%d ",bcd(inb(IO_RTC+1)));
outb(IO_RTC,2); /* minutes */
printf("%d ",bcd(inb(IO_RTC+1)));
outb(IO_RTC,0); /* seconds */
printf("%d\n",bcd(inb(IO_RTC+1)));
time.tv_sec = base;
}
#endif
/*
* Wire clock interrupt in.
*/
void
enablertclock()
{
register_intr(/* irq */ 0, /* XXX id */ 0, /* flags */ 0, clkintr,
HWI_MASK | SWI_MASK, /* unit */ 0);
INTREN(IRQ0);
register_intr(/* irq */ 8, /* XXX id */ 1, /* flags */ 0, rtcintr,
SWI_CLOCK_MASK, /* unit */ 0);
INTREN(IRQ8);
outb(IO_RTC, RTC_STATUSB);
outb(IO_RTC+1, RTCSB_PINTR | RTCSB_24HR);
}
void
cpu_initclocks()
{
stathz = RTC_NOPROFRATE;
profhz = RTC_PROFRATE;
enablertclock();
}
void
setstatclockrate(int newhz)
{
if(newhz == RTC_PROFRATE) {
rtc_statusa = RTCSA_DIVIDER | RTCSA_PROF;
} else {
rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
}
outb(IO_RTC, RTC_STATUSA);
outb(IO_RTC+1, rtc_statusa);
}