Convert x68k to timecounters. This conversion is not tested, due to lack
of available test candidates. It uses the previously unused (as far as I can tell) Timer D, in freerunning mode. It only uses a 1/200 prescaler (20KHz), as anything faster would roll over too fast for the system timer. (Gotta love 8-bit resolution timers!) Approved for untested commit by core@.
This commit is contained in:
gdamore
parent
fc13afb3a4
commit
b7648fa4c0
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@ -1,4 +1,4 @@
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/* $NetBSD: types.h,v 1.10 2006/09/14 01:18:11 gdamore Exp $ */
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/* $NetBSD: types.h,v 1.11 2006/09/19 10:13:10 gdamore Exp $ */
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#ifndef _MACHINE_TYPES_H_
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#define _MACHINE_TYPES_H_
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@ -7,5 +7,6 @@
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#define __HAVE_DEVICE_REGISTER
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#define __HAVE_GENERIC_TODR
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#define __HAVE_TIMECOUNTER
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#endif
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@ -1,4 +1,4 @@
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/* $NetBSD: clock.c,v 1.23 2006/09/14 01:18:11 gdamore Exp $ */
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/* $NetBSD: clock.c,v 1.24 2006/09/19 10:13:10 gdamore Exp $ */
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/*
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* Copyright (c) 1982, 1990, 1993
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@ -77,7 +77,7 @@
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.23 2006/09/14 01:18:11 gdamore Exp $");
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__KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.24 2006/09/19 10:13:10 gdamore Exp $");
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#include "clock.h"
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@ -87,6 +87,7 @@ __KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.23 2006/09/14 01:18:11 gdamore Exp $");
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/device.h>
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#include <sys/timetc.h>
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#include <machine/psl.h>
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#include <machine/cpu.h>
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@ -110,6 +111,8 @@ CFATTACH_DECL(clock, sizeof(struct clock_softc),
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static int clock_attached;
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static unsigned mfp_get_timecount(struct timecounter *);
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static int
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clock_match(struct device *parent, struct cfdata *cf, void *aux)
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{
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@ -135,25 +138,21 @@ clock_attach(struct device *parent, struct device *self, void *aux)
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/*
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* MFP of X68k uses 4MHz clock always and we use 1/200 prescaler here.
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* Therefore, clock interval is 50 usec.
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*
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* Note that for timecounters, we'd like to use a finger grained clock, but
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* since we only have an 8-bit clock, we can't do that without increasing
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* the system clock rate. (Otherwise the counter would roll in less than
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* a single system clock.)
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*/
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#define CLK_RESOLUTION (50)
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#define CLOCKS_PER_SEC (1000000 / CLK_RESOLUTION)
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static int clkint; /* clock interval */
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static int clkread(void);
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/*
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* Machine-dependent clock routines.
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*
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* Startrtclock restarts the real-time clock, which provides
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* hardclock interrupts to kern_clock.c.
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*
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* Inittodr initializes the time of day hardware which provides
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* date functions.
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*
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* Resettodr restores the time of day hardware after a time change.
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*
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* A note on the real-time clock:
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* We actually load the clock with CLK_INTERVAL-1 instead of CLK_INTERVAL.
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* This is because the counter decrements to zero after N+1 enabled clock
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@ -168,18 +167,30 @@ static int clkread(void);
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void
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cpu_initclocks(void)
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{
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static struct timecounter tc = {
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.tc_name = "mfp",
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.tc_frequency = CLOCKS_PER_SEC,
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.tc_counter_mask = 0xff,
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.tc_get_timecount = mfp_get_timecount,
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.tc_quality = 100,
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};
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if (CLOCKS_PER_SEC % hz ||
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hz <= (CLOCKS_PER_SEC / 256) || hz > CLOCKS_PER_SEC) {
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printf("cannot set %d Hz clock. using 100 Hz\n", hz);
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hz = 100;
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}
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clkint = CLOCKS_PER_SEC / hz;
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mfp_set_tcdcr(mfp_get_tcdcr() & 0x0f); /* stop timer C */
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mfp_set_tcdcr(0); /* stop timers C and D */
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mfp_set_tcdcr(mfp_get_tcdcr() | 0x70); /* 1/200 delay mode */
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mfp_set_tcdr(clkint);
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mfp_set_tcdr(CLOCKS_PER_SEC / hz);
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mfp_bit_set_ierb(MFP_INTR_TIMER_C);
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mfp_set_tddr(0xff); /* maximum free run -- only 8 bits wide */
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mfp_set_tcdcr(mfp_get_tcdcr() | 0x07); /* 1/200 prescaler */
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tc_init(&tc);
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}
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/*
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@ -196,13 +207,14 @@ setstatclockrate(int newhz)
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* Returns number of usec since last recorded clock "tick"
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* (i.e. clock interrupt).
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*/
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int
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clkread(void)
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unsigned
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mfp_get_timecount(struct timecounter *tc)
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{
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return (clkint - mfp_get_tcdr()) * CLK_RESOLUTION;
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uint8_t val;
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val = ~(mfp_get_tddr());
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return (val);
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}
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#if 0
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void
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DELAY(mic)
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@ -512,29 +524,6 @@ profclock(caddr_t pc, int ps)
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#endif /* PROF */
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#endif /* PROFTIMER */
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/*
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* Return the best possible estimate of the current time.
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*/
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void
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microtime(struct timeval *tvp)
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{
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static struct timeval lasttime;
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*tvp = time;
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tvp->tv_usec += clkread();
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while (tvp->tv_usec >= 1000000) {
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tvp->tv_sec++;
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tvp->tv_usec -= 1000000;
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}
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if (tvp->tv_sec == lasttime.tv_sec &&
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tvp->tv_usec <= lasttime.tv_usec &&
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(tvp->tv_usec = lasttime.tv_usec + 1) >= 1000000) {
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tvp->tv_sec++;
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tvp->tv_usec -= 1000000;
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}
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lasttime = *tvp;
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}
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#else /* NCLOCK */
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#error loose.
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#endif
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