4.4BSD/usr/src/sys/i386/isa/clock.c
/*-
* Copyright (c) 1990, 1993
* 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
* from NetBSD: Id: clock.c,v 1.6 1993/05/22 08:01:07 cgd Exp
*
* @(#)clock.c 8.1 (Berkeley) 6/11/93
*
*/
/*
* Primitive clock interrupt routines.
*/
#include <sys/param.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <machine/segments.h>
#include <i386/isa/icu.h>
#include <i386/isa/isa.h>
#include <i386/isa/rtc.h>
/* these should go elsewere (timerreg.h) but to avoid admin overhead... */
/*
* Macros for specifying values to be written into a mode register.
*/
#define TIMER_CNTR0 (IO_TIMER1 + 0) /* timer 0 counter port */
#define TIMER_CNTR1 (IO_TIMER1 + 1) /* timer 1 counter port */
#define TIMER_CNTR2 (IO_TIMER1 + 2) /* timer 2 counter port */
#define TIMER_MODE (IO_TIMER1 + 3) /* timer mode port */
#define TIMER_SEL0 0x00 /* select counter 0 */
#define TIMER_SEL1 0x40 /* select counter 1 */
#define TIMER_SEL2 0x80 /* select counter 2 */
#define TIMER_INTTC 0x00 /* mode 0, intr on terminal cnt */
#define TIMER_ONESHOT 0x02 /* mode 1, one shot */
#define TIMER_RATEGEN 0x04 /* mode 2, rate generator */
#define TIMER_SQWAVE 0x06 /* mode 3, square wave */
#define TIMER_SWSTROBE 0x08 /* mode 4, s/w triggered strobe */
#define TIMER_HWSTROBE 0x0a /* mode 5, h/w triggered strobe */
#define TIMER_LATCH 0x00 /* latch counter for reading */
#define TIMER_LSB 0x10 /* r/w counter LSB */
#define TIMER_MSB 0x20 /* r/w counter MSB */
#define TIMER_16BIT 0x30 /* r/w counter 16 bits, LSB first */
#define TIMER_BCD 0x01 /* count in BCD */
#define DAYST 119
#define DAYEN 303
#ifndef XTALSPEED
#define XTALSPEED 1193182
#endif
startrtclock() {
int s;
findcpuspeed(); /* use the clock (while it's free)
to find the cpu speed */
/* 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, (XTALSPEED+hz/2)/hz);
outb (IO_TIMER1, ((XTALSPEED+hz/2)/hz)/256);
/* initialize brain-dead battery powered clock */
outb (IO_RTC, RTC_STATUSA);
outb (IO_RTC+1, 0x26);
outb (IO_RTC, RTC_STATUSB);
outb (IO_RTC+1, 2);
outb (IO_RTC, RTC_DIAG);
if (s = inb (IO_RTC+1))
printf("RTC BIOS diagnostic error %b\n", s, RTCDG_BITS);
outb (IO_RTC, RTC_DIAG);
outb (IO_RTC+1, 0);
}
unsigned int delaycount; /* calibrated loop variable (1 millisecond) */
#define FIRST_GUESS 0x2000
findcpuspeed()
{
unsigned char low;
unsigned int remainder;
/* Put counter in count down mode */
outb(IO_TIMER1+3, 0x34);
outb(IO_TIMER1, 0xff);
outb(IO_TIMER1, 0xff);
delaycount = FIRST_GUESS;
spinwait(1);
/* Read the value left in the counter */
low = inb(IO_TIMER1); /* least siginifcant */
remainder = inb(IO_TIMER1); /* most significant */
remainder = (remainder<<8) + low ;
/* Formula for delaycount is :
* (loopcount * timer clock speed)/ (counter ticks * 1000)
*/
delaycount = (FIRST_GUESS * (XTALSPEED/1000)) / (0xffff-remainder);
}
/* convert 2 digit BCD number */
bcd(i)
int i;
{
return ((i/16)*10 + (i%16));
}
/* convert years to seconds (from 1970) */
unsigned long
ytos(y)
int y;
{
int i;
unsigned long ret;
ret = 0;
for(i = 1970; i < y; i++) {
if (i % 4) ret += 365*24*60*60;
else ret += 366*24*60*60;
}
return ret;
}
/* convert months to seconds */
unsigned long
mtos(m,leap)
int m,leap;
{
int i;
unsigned long ret;
ret = 0;
for(i=1;i<m;i++) {
switch(i){
case 1: case 3: case 5: case 7: case 8: case 10: case 12:
ret += 31*24*60*60; break;
case 4: case 6: case 9: case 11:
ret += 30*24*60*60; break;
case 2:
if (leap) ret += 29*24*60*60;
else ret += 28*24*60*60;
}
}
return ret;
}
/*
* Initialize the time of day register, based on the time base which is, e.g.
* from a filesystem.
*/
inittodr(base)
time_t base;
{
unsigned long sec;
int leap,day_week,t,yd;
int sa,s;
/* do we have a realtime clock present? (otherwise we loop below) */
sa = rtcin(RTC_STATUSA);
if (sa == 0xff || sa == 0) return;
/* ready for a read? */
while ((sa&RTCSA_TUP) == RTCSA_TUP)
sa = rtcin(RTC_STATUSA);
sec = bcd(rtcin(RTC_YEAR)) + 1900;
if (sec < 1970)
sec += 100;
leap = !(sec % 4); sec = ytos(sec); /* year */
yd = mtos(bcd(rtcin(RTC_MONTH)),leap); sec += yd; /* month */
t = (bcd(rtcin(RTC_DAY))-1) * 24*60*60; sec += t; yd += t; /* date */
day_week = rtcin(RTC_WDAY); /* day */
sec += bcd(rtcin(RTC_HRS)) * 60*60; /* hour */
sec += bcd(rtcin(RTC_MIN)) * 60; /* minutes */
sec += bcd(rtcin(RTC_SEC)); /* seconds */
/* XXX off by one? Need to calculate DST on SUNDAY */
/* Perhaps we should have the RTC hold GMT time to save */
/* us the bother of converting. */
yd = yd / (24*60*60);
if ((yd >= DAYST) && ( yd <= DAYEN)) {
sec -= 60*60;
}
sec += tz.tz_minuteswest * 60;
time.tv_sec = sec;
}
#ifdef garbage
/*
* Initialze the time of day register, based on the time base which is, e.g.
* from a filesystem.
*/
test_inittodr(base)
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
/*
* Restart the clock.
*/
resettodr()
{
}
/*
* Wire clock interrupt in.
*/
#define V(s) __CONCAT(V, s)
extern V(clk)();
enablertclock() {
INTREN(IRQ0);
setidt(ICU_OFFSET+0, &V(clk), SDT_SYS386IGT, SEL_KPL);
splnone();
}
spinwait(millisecs)
int millisecs; /* number of milliseconds to delay */
{
int i, j;
for (i=0;i<millisecs;i++)
for (j=0;j<delaycount;j++)
;
}