/*	$OpenBSD: nvram.c,v 1.3 1999/01/11 05:11:43 millert Exp $ */

/*
 * Copyright (c) 1995 Theo de Raadt
 * 
 * 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 under OpenBSD by
 *	Theo de Raadt for Willowglen Singapore.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/ioctl.h>
#include <sys/device.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <machine/psl.h>
#include <machine/autoconf.h>
#include <machine/cpu.h>
#include <machine/mioctl.h>
#include <machine/vmparam.h>
#include <mvme88k/dev/nvramreg.h>
#include <mvme88k/dev/pcctworeg.h>


struct nvramsoftc {
	struct device		sc_dev;
	void *		sc_paddr;
	void *		sc_vaddr;
	int		sc_len;
	struct clockreg *sc_regs;
};

void	nvramattach	__P((struct device *, struct device *, void *));
int	nvrammatch __P((struct device *, void *, void *));

struct cfattach nvram_ca = { 
        sizeof(struct nvramsoftc), nvrammatch, nvramattach
}; 
 
struct cfdriver nvram_cd = {
        NULL, "nvram", DV_DULL, 0
};

int
nvrammatch(parent, vcf, args)
	struct device *parent;
	void *vcf, *args;
	{
	struct cfdata *cf = vcf;
	struct confargs *ca = args;

/*X*/	if (ca->ca_vaddr == (void *)-1)
/*X*/		return (1);
	return (!badvaddr(ca->ca_vaddr, 1));
}

void
nvramattach(parent, self, args)
	struct device *parent, *self;
	void *args;
{
	struct confargs *ca = args;
	struct nvramsoftc	*sc = (struct nvramsoftc *)self;

	sc->sc_paddr = ca->ca_paddr;
	sc->sc_vaddr = ca->ca_vaddr;

	sc->sc_len = MK48T08_SIZE;

/*X*/	if (sc->sc_vaddr == (void *)-1)
/*X*/		sc->sc_vaddr = mapiodev((void *)sc->sc_paddr,
/*X*/		    max(sc->sc_len, NBPG));
/*X*/	if (sc->sc_vaddr == NULL)
/*X*/		panic("failed to map!");

	sc->sc_regs = (struct clockreg *)(sc->sc_vaddr + sc->sc_len -
	    sizeof(struct clockreg));

	printf(": MK48T0%d len %d\n", sc->sc_len / 1024, sc->sc_len);
}

/*
 * Return the best possible estimate of the time in the timeval
 * to which tvp points.  We do this by returning the current time
 * plus the amount of time since the last clock interrupt (clock.c:clkread).
 *
 * Check that this time is no less than any previously-reported time,
 * which could happen around the time of a clock adjustment.  Just for fun,
 * we guarantee that the time will be greater than the value obtained by a
 * previous call.
 */
void
microtime(tvp)
	register struct timeval *tvp;
{
	int s = splhigh();
	static struct timeval lasttime;

	*tvp = time;
	tvp->tv_usec;
	while (tvp->tv_usec > 1000000) {
		tvp->tv_sec++;
		tvp->tv_usec -= 1000000;
	}
	if (tvp->tv_sec == lasttime.tv_sec &&
	    tvp->tv_usec <= lasttime.tv_usec &&
	    (tvp->tv_usec = lasttime.tv_usec + 1) > 1000000) {
		tvp->tv_sec++;
		tvp->tv_usec -= 1000000;
	}
	lasttime = *tvp;
	splx(s);
}

/*
 * BCD to decimal and decimal to BCD.
 */
#define	FROMBCD(x)	(((x) >> 4) * 10 + ((x) & 0xf))
#define	TOBCD(x)	(((x) / 10 * 16) + ((x) % 10))

#define	SECDAY		(24 * 60 * 60)
#define	SECYR		(SECDAY * 365)
#define	LEAPYEAR(y)	(((y) & 3) == 0)

/*
 * This code is defunct after 2068.
 * Will Unix still be here then??
 */
const short dayyr[12] =
    { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };

static u_long
chiptotime(sec, min, hour, day, mon, year)
	register int sec, min, hour, day, mon, year;
{
	register int days, yr;

	sec = FROMBCD(sec);
	min = FROMBCD(min);
	hour = FROMBCD(hour);
	day = FROMBCD(day);
	mon = FROMBCD(mon);
	year = FROMBCD(year) + YEAR0;

	/* simple sanity checks */
	if (year < 70 || year > 164 || mon < 1 || mon > 12 || day < 1 || day > 31)
		return (0);
	days = 0;
	for (yr = 70; yr < year; yr++)
		days += LEAPYEAR(yr) ? 366 : 365;
	days += dayyr[mon - 1] + day - 1;
	if (LEAPYEAR(yr) && mon > 2)
		days++;
	/* now have days since Jan 1, 1970; the rest is easy... */
	return (days * SECDAY + hour * 3600 + min * 60 + sec);
}

struct chiptime {
	int	sec;
	int	min;
	int	hour;
	int	wday;
	int	day;
	int	mon;
	int	year;
};

timetochip(c)
	register struct chiptime *c;
{
	register int t, t2, t3, now = time.tv_sec;

	/* compute the year */
	t2 = now / SECDAY;
	t3 = (t2 + 2) % 7;	/* day of week */
	c->wday = TOBCD(t3 + 1);

	t = 69;
	while (t2 >= 0) {	/* whittle off years */
		t3 = t2;
		t++;
		t2 -= LEAPYEAR(t) ? 366 : 365;
	}
	c->year = t;

	/* t3 = month + day; separate */
	t = LEAPYEAR(t);
	for (t2 = 1; t2 < 12; t2++)
		if (t3 < dayyr[t2] + (t && t2 > 1))
			break;

	/* t2 is month */
	c->mon = t2;
	c->day = t3 - dayyr[t2 - 1] + 1;
	if (t && t2 > 2)
		c->day--;

	/* the rest is easy */
	t = now % SECDAY;
	c->hour = t / 3600;
	t %= 3600;
	c->min = t / 60;
	c->sec = t % 60;

	c->sec = TOBCD(c->sec);
	c->min = TOBCD(c->min);
	c->hour = TOBCD(c->hour);
	c->day = TOBCD(c->day);
	c->mon = TOBCD(c->mon);
	c->year = TOBCD(c->year - YEAR0);
}

/*
 * Set up the system's time, given a `reasonable' time value.
 */
void 
inittodr(base)
	time_t base;
{
	struct nvramsoftc *sc = (struct nvramsoftc *) nvram_cd.cd_devs[0];
	register struct clockreg *cl = sc->sc_regs;
	int sec, min, hour, day, mon, year;
	int badbase = 0, waszero = base == 0;

	if (base < 5 * SECYR) {
		/*
		 * If base is 0, assume filesystem time is just unknown
		 * in stead of preposterous. Don't bark.
		 */
		if (base != 0)
			printf("WARNING: preposterous time in file system\n");
		/* not going to use it anyway, if the chip is readable */
		base = 21*SECYR + 186*SECDAY + SECDAY/2;
		badbase = 1;
	}
	cl->cl_csr |= CLK_READ;		/* enable read (stop time) */
	sec = cl->cl_sec;
	min = cl->cl_min;
	hour = cl->cl_hour;
	day = cl->cl_mday;
	mon = cl->cl_month;
	year = cl->cl_year;
	cl->cl_csr &= ~CLK_READ;	/* time wears on */
	if ((time.tv_sec = chiptotime(sec, min, hour, day, mon, year)) == 0) {
		printf("WARNING: bad date in nvram");
		/*
		 * Believe the time in the file system for lack of
		 * anything better, resetting the clock.
		 */
		time.tv_sec = base;
		if (!badbase)
			resettodr();
	} else {
		int deltat = time.tv_sec - base;

		if (deltat < 0)
			deltat = -deltat;
		if (waszero || deltat < 2 * SECDAY)
			return;
		printf("WARNING: clock %s %d days",
		    time.tv_sec < base ? "lost" : "gained", deltat / SECDAY);
	}
	printf(" -- CHECK AND RESET THE DATE!\n");
}

/*
 * Reset the clock based on the current time.
 * Used when the current clock is preposterous, when the time is changed,
 * and when rebooting.  Do nothing if the time is not yet known, e.g.,
 * when crashing during autoconfig.
 */
void resettodr()
{
	struct nvramsoftc *sc = (struct nvramsoftc *) nvram_cd.cd_devs[0];
	register struct clockreg *cl = sc->sc_regs;
	struct chiptime c;

	if (!time.tv_sec || cl == NULL)
		return;
	timetochip(&c);
	cl->cl_csr |= CLK_WRITE;	/* enable write */
	cl->cl_sec = c.sec;
	cl->cl_min = c.min;
	cl->cl_hour = c.hour;
	cl->cl_wday = c.wday;
	cl->cl_mday = c.day;
	cl->cl_month = c.mon;
	cl->cl_year = c.year;
	cl->cl_csr &= ~CLK_WRITE;	/* load them up */
}

/*ARGSUSED*/
int
nvramopen(dev, flag, mode)
	dev_t dev;
	int flag, mode;
{
	if (minor(dev) >= nvram_cd.cd_ndevs ||
	    nvram_cd.cd_devs[minor(dev)] == NULL)
		return (ENODEV);
	return (0);
}

/*ARGSUSED*/
int
nvramclose(dev, flag, mode)
	dev_t dev;
	int flag, mode;
{

	return (0);
}

/*ARGSUSED*/
int
nvramioctl(dev, cmd, data, flag, p)
	dev_t   dev;
	caddr_t data;
	int     cmd, flag;
	struct proc *p;
{
	int unit = minor(dev);
	struct nvramsoftc *sc = (struct nvramsoftc *) nvram_cd.cd_devs[unit];
	int error = 0;
	
	switch (cmd) {
	case MIOCGSIZ:
		*(int *)data = sc->sc_len;
		break;
	default:
		error = ENOTTY;
		break;
	}
	return (error);
}

/*ARGSUSED*/
int
nvramread(dev, uio, flags)
	dev_t dev;
	struct uio *uio;
	int flags;
{
	int unit = minor(dev);
	struct nvramsoftc *sc = (struct nvramsoftc *) nvram_cd.cd_devs[unit];

	return (memdevrw(sc->sc_vaddr, sc->sc_len, uio, flags));
}

/*ARGSUSED*/
int
nvramwrite(dev, uio, flags)
	dev_t dev;
	struct uio *uio;
	int flags;
{
	int unit = minor(dev);
	struct nvramsoftc *sc = (struct nvramsoftc *) nvram_cd.cd_devs[unit];

	return (memdevrw(sc->sc_vaddr, sc->sc_len, uio, flags));
}

/*
 * If the NVRAM is of the 2K variety, an extra 2K of who-knows-what
 * will also be mmap'd, due to NBPG being 4K. On the MVME147 the NVRAM
 * repeats, so userland gets two copies back-to-back.
 */
int
nvrammmap(dev, off, prot)
	dev_t dev;
	int off, prot;
{
	int unit = minor(dev);
	struct nvramsoftc *sc = (struct nvramsoftc *) nvram_cd.cd_devs[unit];

	if (minor(dev) != 0)
		return (-1);

	/* allow access only in RAM */
	if (off > sc->sc_len)
		return (-1);
	return (m88k_btop(sc->sc_paddr + off));
}