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Diffstat (limited to 'sys/i386/i386/tsc.c')
| -rw-r--r-- | sys/i386/i386/tsc.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/sys/i386/i386/tsc.c b/sys/i386/i386/tsc.c new file mode 100644 index 0000000..0fb7701 --- /dev/null +++ b/sys/i386/i386/tsc.c @@ -0,0 +1,271 @@ +/*- + * 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. + * + * @(#)clock.c 7.2 (Berkeley) 5/12/91 + * + * PATCHES MAGIC LEVEL PATCH THAT GOT US HERE + * -------------------- ----- ---------------------- + * CURRENT PATCH LEVEL: 5 00158 + * -------------------- ----- ---------------------- + * + * 14 Aug 92 Arne Henrik Juul Added code in the kernel to + * allow for DST in the BIOS. + * 17 Jan 93 Bruce Evans Fixed leap year and second + * calculations + * 01 Feb 93 Julian Elischer Added code to for the cpu + * speed independent spinwait() + * function, (used by scsi and others) + * 25 Mar 93 Sean Eric Fagan Add microtimer support using timer 1 + * 08 Apr 93 Poul-Henning Kamp/P-HK Fixes, and support for dcfclock + * 26 Apr 93 Bruce Evans Eliminate findspeed, new spinwait + * 26 Apr 93 Rodney W. Grimes I merged in Bruce changes and hope I + * still kept the other fixes... Had to + * add back in findcpuspeed that Bruce + * had removed. + */ + +/* + * Primitive clock interrupt routines. + */ +#include "param.h" +#include "systm.h" +#include "time.h" +#include "kernel.h" +#include "machine/segments.h" +#include "i386/isa/icu.h" +#include "i386/isa/isa.h" +#include "i386/isa/rtc.h" +#include "i386/isa/timerreg.h" + +#define DAYST 119 +#define DAYEN 303 + +/* 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 + +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, (TIMER_FREQ+hz/2)/hz); + outb (IO_TIMER1, ((TIMER_FREQ+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 * (TIMER_FREQ/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() { + setidt(ICU_OFFSET+0, &V(clk), SDT_SYS386IGT, SEL_KPL); + INTREN(IRQ0); +} + +/* + * Delay for some number of milliseconds. + */ +void +spinwait(millisecs) + int millisecs; +{ + DELAY(1000 * millisecs); +} |
