xref: /src/sys/arch/atari/dev/clock.c

/*	$NetBSD: clock.c,v 1.1 1995/03/26 07:12:13 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 <sys/param.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <machine/psl.h>
#include <machine/cpu.h>
#include <machine/iomap.h>
#include <machine/mfp.h>
#include <atari/dev/clockreg.h>

#if defined(PROF) && defined(PROFTIMER)
#include <sys/PROF.h>
#endif


/*
 * Machine-dependent clock routines.
 *
 * Startrtclock restarts the real-time clock, which provides
 * hardclock interrupts to kern_clock.c.
 *
 * Inittodr initializes the time of day hardware which provides
 * date functions.
 *
 * Resettodr restores the time of day hardware after a time change.
 *
 * A note on the real-time clock:
 * We actually load the clock with CLK_INTERVAL-1 instead of CLK_INTERVAL.
 * This is because the counter decrements to zero after N+1 enabled clock
 * periods where N is the value loaded into the counter.
 */

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;

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 TT-MFP. An exact reduce to HZ is not
	 * possible by hardware. We use a divisor of 64 and reduce by software
	 * with a factor of 4. The MFP clock runs at 2457600Hz. Therefore the
	 * timer runs at an effective rate of: 2457600/(64*4) = 9600Hz. The
	 * following expression works for all 'normal' values of hz.
	 */
	divisor        = 9600/hz;
	MFP2->mf_tacr  = 0;		/* Stop timer			*/
	MFP2->mf_iera &= ~IA_TIMA2;	/* Disable timer interrupts	*/
	MFP2->mf_tadr  = divisor;	/* Set divisor			*/

	printf(": system hz %d timer-A divisor %d\n", hz, divisor);

	/*
	 * Initialize Timer-B in the TT-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.
	 */
	MFP2->mf_tbcr  = 0;		/* Stop timer			*/
	MFP2->mf_iera &= ~IA_TIMB2;	/* Disable timer interrupts	*/
	MFP2->mf_tbdr  = 0;
	MFP2->mf_tbcr  = T_Q004;	/* Start timer			*/

}

void cpu_initclocks()
{
	MFP2->mf_tacr  = T_Q064;	/* Start timer			*/
	MFP2->mf_ipra &= ~IA_TIMA2;	/* Clear pending interrupts	*/
	MFP2->mf_iera |= IA_TIMA2;	/* Enable timer interrupts	*/
	MFP2->mf_imra |= IA_TIMA2;	/*    .....			*/
}

setstatclockrate(hz)
	int hz;
{
}

/*
 * Returns number of usec since last recorded clock "tick"
 * (i.e. clock interrupt).
 */
clkread()
{
	extern	short	clk_div;
			u_int	delta, elapsed;

	elapsed = (divisor - MFP2->mf_tadr) + ((4 - clk_div) * divisor);
	delta   = (elapsed * tick) / (divisor << 2);

	/*
	 * Account for pending clock interrupts
	 */
	if(MFP2->mf_iera & IA_TIMA2)
		return(delta + tick);
	return(delta);
}

#define TIMB2_FREQ	614400
#define TIMB2_LIMIT	256

/*
 * Wait "n" microseconds.
 * Relies on MFP2-Timer B counting down from TIMB2_LIMIT at TIMB2_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 = MFP2->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" (TIMB2_FREQ));
	    __asm __volatile ("divul %1,%2:%0" : "=d" (n)
					       : "d"(1000000),"d"(temp),"0"(n));
	}

	while(n > 0) {
		tick = MFP2->mf_tbdr;
		if(tick > otick)
			n -= TIMB2_LIMIT - (tick - otick);
		else n -= otick - tick;
		otick = tick;
	}
}

#ifdef notyet
/*
 * Needs to be calibrated for use, its way off most of the time
 */
void
DELAY(mic)
	int mic;
{
	u_long	n;
	short	hpos;

	/*
	 * this function uses HSync pulses as base units. The custom chips
	 * display only deals with 31.6kHz/2 refresh, this gives us a
	 * resolution of 1/15800 s, which is ~63us (add some fuzz so we really
	 * wait awhile, even if using small timeouts)
	 */
	n = mic/63 + 2;
	do {
		hpos = custom.vhposr & 0xff00;
		while (hpos == (custom.vhposr & 0xff00))
			;
	} while (n--);
}
#endif /* notyet */

#if notyet

/* implement this later. I'd suggest using both timers in CIA-A, they're
   not yet used. */

#include "clock.h"
#if NCLOCK > 0
/*
 * /dev/clock: mappable high resolution timer.
 *
 * This code implements a 32-bit recycling counter (with a 4 usec period)
 * using timers 2 & 3 on the 6840 clock chip.  The counter can be mapped
 * RO into a user's address space to achieve low overhead (no system calls),
 * high-precision timing.
 *
 * Note that timer 3 is also used for the high precision profiling timer
 * (PROFTIMER code above).  Care should be taken when both uses are
 * configured as only a token effort is made to avoid conflicting use.
 */
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <vm/vm.h>
#include <amiga/amiga/clockioctl.h>
#include <sys/specdev.h>
#include <sys/vnode.h>
#include <sys/mman.h>

int clockon = 0;		/* non-zero if high-res timer enabled */
#ifdef PROFTIMER
int  profprocs = 0;		/* # of procs using profiling timer */
#endif
#ifdef DEBUG
int clockdebug = 0;
#endif

/*ARGSUSED*/
clockopen(dev, flags)
	dev_t dev;
{
#ifdef PROFTIMER
#ifdef PROF
	/*
	 * Kernel profiling enabled, give up.
	 */
	if (profiling)
		return(EBUSY);
#endif
	/*
	 * If any user processes are profiling, give up.
	 */
	if (profprocs)
		return(EBUSY);
#endif
	if (!clockon) {
		startclock();
		clockon++;
	}
	return(0);
}

/*ARGSUSED*/
clockclose(dev, flags)
	dev_t dev;
{
	(void) clockunmmap(dev, (caddr_t)0, curproc);	/* XXX */
	stopclock();
	clockon = 0;
	return(0);
}

/*ARGSUSED*/
clockioctl(dev, cmd, data, flag, p)
	dev_t		dev;
	u_long		cmd;
	caddr_t		data;
	struct proc	*p;
{
	int error = 0;

	switch (cmd) {

	case CLOCKMAP:
		error = clockmmap(dev, (caddr_t *)data, p);
		break;

	case CLOCKUNMAP:
		error = clockunmmap(dev, *(caddr_t *)data, p);
		break;

	case CLOCKGETRES:
		*(int *)data = CLK_RESOLUTION;
		break;

	default:
		error = EINVAL;
		break;
	}
	return(error);
}

/*ARGSUSED*/
clockmap(dev, off, prot)
	dev_t dev;
{
	return((off + (INTIOBASE+CLKBASE+CLKSR-1)) >> PGSHIFT);
}

clockmmap(dev, addrp, p)
	dev_t dev;
	caddr_t *addrp;
	struct proc *p;
{
	int error;
	struct vnode vn;
	struct specinfo si;
	int flags;

	flags = MAP_FILE|MAP_SHARED;
	if (*addrp)
		flags |= MAP_FIXED;
	else
		*addrp = (caddr_t)0x1000000;	/* XXX */
	vn.v_type = VCHR;			/* XXX */
	vn.v_specinfo = &si;			/* XXX */
	vn.v_rdev = dev;			/* XXX */
	error = vm_mmap(&p->p_vmspace->vm_map, (vm_offset_t *)addrp,
			PAGE_SIZE, VM_PROT_ALL, flags, (caddr_t)&vn, 0);
	return(error);
}

clockunmmap(dev, addr, p)
	dev_t dev;
	caddr_t addr;
	struct proc *p;
{
	int rv;

	if (addr == 0)
		return(EINVAL);		/* XXX: how do we deal with this? */
	rv = vm_deallocate(p->p_vmspace->vm_map, (vm_offset_t)addr, PAGE_SIZE);
	return(rv == KERN_SUCCESS ? 0 : EINVAL);
}

startclock()
{
	register struct clkreg *clk = (struct clkreg *)clkstd[0];

	clk->clk_msb2 = -1; clk->clk_lsb2 = -1;
	clk->clk_msb3 = -1; clk->clk_lsb3 = -1;

	clk->clk_cr2 = CLK_CR3;
	clk->clk_cr3 = CLK_OENAB|CLK_8BIT;
	clk->clk_cr2 = CLK_CR1;
	clk->clk_cr1 = CLK_IENAB;
}

stopclock()
{
	register struct clkreg *clk = (struct clkreg *)clkstd[0];

	clk->clk_cr2 = CLK_CR3;
	clk->clk_cr3 = 0;
	clk->clk_cr2 = CLK_CR1;
	clk->clk_cr1 = CLK_IENAB;
}
#endif

#endif


#ifdef PROFTIMER
/*
 * This code allows the amiga kernel to use one of the extra timers on
 * the clock chip for profiling, instead of the regular system timer.
 * The advantage of this is that the profiling timer can be turned up to
 * a higher interrupt rate, giving finer resolution timing. The profclock
 * routine is called from the lev6intr in locore, and is a specialized
 * routine that calls addupc. The overhead then is far less than if
 * hardclock/softclock was called. Further, the context switch code in
 * locore has been changed to turn the profile clock on/off when switching
 * into/out of a process that is profiling (startprofclock/stopprofclock).
 * This reduces the impact of the profiling clock on other users, and might
 * possibly increase the accuracy of the profiling.
 */
int  profint   = PRF_INTERVAL;	/* Clock ticks between interrupts */
int  profscale = 0;		/* Scale factor from sys clock to prof clock */
char profon    = 0;		/* Is profiling clock on? */

/* profon values - do not change, locore.s assumes these values */
#define PRF_NONE	0x00
#define	PRF_USER	0x01
#define	PRF_KERNEL	0x80

initprofclock()
{
#if NCLOCK > 0
	struct proc *p = curproc;		/* XXX */

	/*
	 * If the high-res timer is running, force profiling off.
	 * Unfortunately, this gets reflected back to the user not as
	 * an error but as a lack of results.
	 */
	if (clockon) {
		p->p_stats->p_prof.pr_scale = 0;
		return;
	}
	/*
	 * Keep track of the number of user processes that are profiling
	 * by checking the scale value.
	 *
	 * XXX: this all assumes that the profiling code is well behaved;
	 * i.e. profil() is called once per process with pcscale non-zero
	 * to turn it on, and once with pcscale zero to turn it off.
	 * Also assumes you don't do any forks or execs.  Oh well, there
	 * is always adb...
	 */
	if (p->p_stats->p_prof.pr_scale)
		profprocs++;
	else
		profprocs--;
#endif
	/*
	 * The profile interrupt interval must be an even divisor
	 * of the CLK_INTERVAL so that scaling from a system clock
	 * tick to a profile clock tick is possible using integer math.
	 */
	if (profint > CLK_INTERVAL || (CLK_INTERVAL % profint) != 0)
		profint = CLK_INTERVAL;
	profscale = CLK_INTERVAL / profint;
}

startprofclock()
{
  unsigned short interval;

  /* stop timer B */
  ciab.crb = ciab.crb & 0xc0;

  /* load interval into registers.
     the clocks run at NTSC: 715.909kHz or PAL: 709.379kHz */

  interval = profint - 1;

  /* order of setting is important ! */
  ciab.tblo = interval & 0xff;
  ciab.tbhi = interval >> 8;

  /* enable interrupts for timer B */
  ciab.icr = (1<<7) | (1<<1);

  /* start timer B in continuous shot mode */
  ciab.crb = (ciab.crb & 0xc0) | 1;
}

stopprofclock()
{
  /* stop timer B */
  ciab.crb = ciab.crb & 0xc0;
}

#ifdef PROF
/*
 * 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
#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 __inline__ int rtc_getclkreg(regno)
int	regno;
{
	RTC->rtc_regno = RTC_REGA;
	RTC->rtc_regno = regno;
	return(RTC->rtc_data & 0377);
}

static __inline__ void rtc_setclkreg(regno, value)
int	regno, value;
{
	RTC->rtc_regno = regno;
	RTC->rtc_data  = value;
}

static u_long
gettod()
{
	int		i, year, mon, day, hour, min, sec;
	u_long	new_time = 0;
	char	*msize;

	/*
	 * Hold clock
	 */
	rtc_setclkreg(RTC_REGB, rtc_getclkreg(RTC_REGB) | RTC_B_SET);

	/*
	 * Read clock
	 */
	sec  = rtc_getclkreg(RTC_SEC);
	min  = rtc_getclkreg(RTC_MIN);
	hour = rtc_getclkreg(RTC_HOUR);
	day  = rtc_getclkreg(RTC_DAY) - 1;
	mon  = rtc_getclkreg(RTC_MONTH) - 1;
	year = rtc_getclkreg(RTC_YEAR) + STARTOFTIME;

	/*
	 * Let it run again..
	 */
	rtc_setclkreg(RTC_REGB, rtc_getclkreg(RTC_REGB) & ~RTC_B_SET);

	if(range_test(hour, 0, 23))
		return(0);
	if(range_test(day, 0, 30))
		return(0);
	if (range_test(mon, 0, 11))
		return(0);
	if(range_test(year, STARTOFTIME, 2000))
		return(0);

	for(i = STARTOFTIME; i < year; i++) {
		if(is_leap(i))
			new_time += 366;
		else new_time += 365;
	}

	msize = is_leap(year) ? ldmsize : dmsize;
	for(i = 0; i < mon; i++)
		new_time += msize[i];
	new_time += day;
	return((new_time * SECS_DAY) + (hour * 3600) + (min * 60) + sec);
}

static int
settod(newtime)
u_long	newtime;
{
	register long	days, rem, year;
	register char	*ml;
			 int	sec, min, hour, month;

	/* Number of days since Jan. 1 1970	*/
	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 = STARTOFTIME;
	while(days >= (rem = is_leap(year) ? 366 : 365)) {
	  ++year;
	  days -= rem;
	}
	while(days < 0) {
	  --year;
	  days += is_leap(year) ? 366 : 365;
	}

	/*
	 * 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
	 */
	rtc_setclkreg(RTC_REGB, RTC_B_SET);
	rtc_setclkreg(RTC_REGA, RTC_A_DV1|RTC_A_RS2|RTC_A_RS3);
	rtc_setclkreg(RTC_REGB, RTC_B_SET|RTC_B_SQWE|RTC_B_DM|RTC_B_24_12);
	rtc_setclkreg(RTC_SEC, sec);
	rtc_setclkreg(RTC_MIN, min);
	rtc_setclkreg(RTC_HOUR, hour);
	rtc_setclkreg(RTC_DAY, days+1);
	rtc_setclkreg(RTC_MONTH, month+1);
	rtc_setclkreg(RTC_YEAR, year-1970);
	rtc_setclkreg(RTC_REGB, RTC_B_SQWE|RTC_B_DM|RTC_B_24_12);

	return(1);
}