/* $NetBSD: clock.c,v 1.6 1995/12/01 19:51:53 leo 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 #include #include #include #include #include #include #include #if defined(GPROF) && defined(PROFTIMER) #include #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 *, struct cfdata *, void *)); void clockattach __P((struct device *, struct device *, void *)); struct cfdriver clockcd = { NULL, "clock", (cfmatch_t)clockmatch, clockattach, DV_DULL, sizeof(struct device), NULL, 0 }; 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, cfp, auxp) struct device *pdp; struct cfdata *cfp; void *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 */ } 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). */ 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 /* * Initialize the time of day register, based on the time base which is, e.g. * from a filesystem. */ 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; } 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(range_test(clkregs[MC_HOUR], 0, 23)) return(0); if(range_test(clkregs[MC_DOM], 1, 31)) return(0); if (range_test(clkregs[MC_MONTH], 1, 12)) return(0); if(range_test(clkregs[MC_YEAR], 0, 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); }