NetBSD/sys/arch/arm/ixp12x0/ixp12x0_clk.c

/*	$NetBSD: ixp12x0_clk.c,v 1.2 2002/07/21 14:19:43 ichiro Exp $	*/

/*
 * Copyright (c) 1997 Mark Brinicombe.
 * Copyright (c) 1997 Causality Limited.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by IWAMOTO Toshihiro and Ichiro FUKUHARA.
 *
 * 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 NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/time.h>
#include <sys/device.h>

#include <machine/bus.h>
#include <machine/intr.h>

#include <arm/cpufunc.h>

#include <arm/ixp12x0/ixpsipvar.h> 

#include <arm/ixp12x0/ixp12x0_pcireg.h> 
#include <arm/ixp12x0/ixp12x0_clkreg.h> 
#include <arm/ixp12x0/ixp12x0var.h>

static int	ixpclk_match(struct device *, struct cfdata *, void *);
static void	ixpclk_attach(struct device *, struct device *, void *);

int		gettick(void);
void		rtcinit(void);

/* callback functions for intr_functions */
static int      ixpclk_intr(void* arg);

struct ixpclk_softc {
	struct device		sc_dev;
	bus_addr_t		sc_baseaddr;
	bus_space_tag_t		sc_iot;
	bus_space_handle_t	sc_ioh;

	u_int32_t		sc_clock_count;
	u_int32_t		sc_count_per_usec;
	u_int32_t		sc_coreclock_freq;
};

#define XTAL_FREQ		3686400		/* 3.6864MHz */
#define XTAL_FREQ3686400
#undef XTAL_FREQ3787800
#undef XTAL_FREQ3579500
#define	MAX_CCF			22

#if defined(XTAL_FREQ3686400)
static u_int32_t ccf_to_coreclock[MAX_CCF + 1] = {
	29491000,
	36865000,
	44237000,
	51610000,
	58982000,
	66355000,
	73728000,
	81101000,
	88474000,
	95846000,
	103219000,
	110592000,
	132710000,
	147456000,
	154829000,
	162202000,
	165890000,
	176947000,
	191693000,
	199066000,
	206438000,
	221184000,
	232243000,
};
#elif defined(XTAL_FREQ3787800)
#elif defined(XTAL_FREQ3579500)
#else
#error
#endif

static struct ixpclk_softc *ixpclk_sc = NULL;

#define TIMER_FREQUENCY         3686400         /* 3.6864MHz */
#define TICKS_PER_MICROSECOND   (TIMER_FREQUENCY/1000000)

struct cfattach ixpclk_ca = {
	sizeof(struct ixpclk_softc), ixpclk_match, ixpclk_attach
};

#define GET_TIMER_VALUE(sc)	(bus_space_read_4((sc)->sc_iot,		\
						  (sc)->sc_ioh,		\
						  IXPCLK_VALUE)		\
				 & IXPCL_CTV)

static int
ixpclk_match(parent, match, aux)
	struct device *parent;
	struct cfdata *match;
	void *aux;
{
	return (1);
}

static void
ixpclk_attach(parent, self, aux)
	struct device *parent;
	struct device *self;
	void *aux;
{
	struct ixpclk_softc *sc = (struct ixpclk_softc*) self;
	struct ixpsip_attach_args *sa = aux;

	printf("\n");

	sc->sc_iot = sa->sa_iot;
	sc->sc_baseaddr = sa->sa_addr;

	/* using first timer for system ticks */
	if (ixpclk_sc == NULL)
		ixpclk_sc = sc;

	if (bus_space_map(sa->sa_iot, sa->sa_addr, sa->sa_size, 0,
			  &sc->sc_ioh))
		panic("%s: Cannot map registers\n", self->dv_xname);

	/* disable all channel and clear interrupt status */
	bus_space_write_4(sc->sc_iot, sc->sc_ioh, IXPCLK_CONTROL,
			  IXPCL_DISABLE | IXPCL_PERIODIC | IXPCL_STP_CORE);
	bus_space_write_4(sc->sc_iot, sc->sc_ioh, IXPCLK_CLEAR, 0);
	printf("%s: IXP12x0 Interval Timer\n",  sc->sc_dev.dv_xname);
}

/*
 * ixpclk_intr:
 *
 *	Handle the hardclock interrupt.
 */
static int
ixpclk_intr(void *arg)
	
{
	/* XXX XXX */
	if (!(IXPREG(IXPPCI_IRQ_RAW_STATUS)
	      & (1U << (IXPPCI_INTR_T1 - SYS_NIRQ))))
		return (0);

	bus_space_write_4(ixpclk_sc->sc_iot, ixpclk_sc->sc_ioh,
			  IXPCLK_CLEAR, 1);

	hardclock((struct clockframe*) arg);
	return (1);
}

/*
 * setstatclockrate:
 *
 *	Set the rate of the statistics clock.
 *
 *	We assume that hz is either stathz or profhz, and that neither
 *	will change after being set by cpu_initclocks().  We could
 *	recalculate the intervals here, but that would be a pain.
 */
void
setstatclockrate(hz)
	int hz;
{
	/* use hardclock */

	/* XXX should I use TIMER2? */
}

/*
 * cpu_initclocks:
 *
 *	Initialize the clock and get them going.
 */
void
cpu_initclocks()
{
	struct ixpclk_softc*	sc = ixpclk_sc;
	u_int32_t		ccf;

	stathz = profhz = 0;

	printf("clock: hz = %d stathz = %d\n", hz, stathz);

	ccf = IXPREG(IXP12X0_PLL_CFG) & IXP12X0_PLL_CFG_CCF;
	sc->sc_coreclock_freq = ccf_to_coreclock[ccf];

	printf("pll_cfg:ccf = %x coreclock frequency = %dHz\n",
	       ccf, sc->sc_coreclock_freq);

	sc->sc_clock_count = sc->sc_coreclock_freq / hz;
	sc->sc_count_per_usec = sc->sc_coreclock_freq / 10000000;

	bus_space_write_4(sc->sc_iot, sc->sc_ioh, IXPCLK_CLEAR, IXPT_CLEAR);

	ixp12x0_intr_establish(IXPPCI_INTR_T1, IPL_CLOCK, ixpclk_intr, NULL);

	IXPREG(IXPPCI_IRQ_ENABLE_SET) = (1U << (IXPPCI_INTR_T1 - SYS_NIRQ));

	bus_space_write_4(sc->sc_iot, sc->sc_ioh, IXPCLK_LOAD,
			  sc->sc_clock_count);
	bus_space_write_4(sc->sc_iot, sc->sc_ioh, IXPCLK_CONTROL,
			  IXPCL_ENABLE | IXPCL_PERIODIC
			  | IXPCL_STP_CORE);
}

int
gettick()
{
	int counter;
	u_int savedints;
	savedints = disable_interrupts(I32_bit);

	counter = GET_TIMER_VALUE(ixpclk_sc);

	restore_interrupts(savedints);
	return counter;
}

/*
 * microtime:
 *
 *	Fill in the specified timeval struct with the current time
 *	accurate to the microsecond.
 */
void
microtime(tvp)
	register struct timeval *tvp;
{
	u_int			oldirqstate;
	u_int32_t		counts;
	static struct timeval	lasttv;

	if (ixpclk_sc == NULL) {
#ifdef DEBUG
		printf("microtime: called befor initialize ixpclk\n");
#endif
		tvp->tv_sec = 0;
		tvp->tv_usec = 0;
		return;
	}

	oldirqstate = disable_interrupts(I32_bit);

	counts = ixpclk_sc->sc_clock_count - GET_TIMER_VALUE(ixpclk_sc);

        /* Fill in the timeval struct. */
	*tvp = time;
	tvp->tv_usec += counts / ixpclk_sc->sc_count_per_usec;

        /* Make sure microseconds doesn't overflow. */
	while (tvp->tv_usec >= 1000000) {
		tvp->tv_usec -= 1000000;
		tvp->tv_sec++;
	}

        /* Make sure the time has advanced. */
	if (tvp->tv_sec == lasttv.tv_sec &&
	    tvp->tv_usec <= lasttv.tv_usec) {
		tvp->tv_usec = lasttv.tv_usec + 1;
		if (tvp->tv_usec >= 1000000) {
			tvp->tv_usec -= 1000000;
			tvp->tv_sec++;
		}
	}

	lasttv = *tvp;

	restore_interrupts(oldirqstate);
}

/*
 * delay:
 *
 *	Delay for at least N microseconds.
 */
void
delay(usecs)
	u_int usecs;
{
	u_int32_t tick, otick, delta;
	int j, csec, usec;

	csec = usecs / 10000;
	usec = usecs % 10000;
	
	if (ixpclk_sc == NULL) {
		static u_int32_t	coreclock_freq = 0;

#ifdef DEBUG
		printf("delay: called befor initialize ixpclk\n");
#endif
		if (coreclock_freq == 0) {
			coreclock_freq
				= ccf_to_coreclock[IXPREG(IXP12X0_PLL_CFG)
						   & IXP12X0_PLL_CFG_CCF];
		}

		usecs = (TIMER_FREQUENCY / 100) * csec
			+ (TIMER_FREQUENCY / 100) * usec / 10000;
		/* clock isn't initialized yet */
		for(; usecs > 0; usecs--)
			for(j = 100; j > 0; j--)
				;
		return;
	}

	usecs = (ixpclk_sc->sc_coreclock_freq / 100) * csec
		+ (ixpclk_sc->sc_coreclock_freq / 100) * usec / 10000;

	otick = gettick();

	while (1) {
		for(j = 100; j > 0; j--)
			;
		tick = gettick();

		delta = otick > tick
			? otick - tick
			: otick - tick + IXPCL_ITV + 1;
		if (delta > usecs)
			break;
		usecs -= delta;
		otick = tick;
	}
}

void
resettodr()
{
}

void
inittodr(base)
	time_t base;
{
	time.tv_sec = base;
	time.tv_usec = 0;
}