/*      $NetBSD: gemini_timer.c,v 1.7 2014/03/18 12:54:29 martin Exp $  */

/* adapted from:
 *      NetBSD: omap2_geminitmr.c,v 1.1 2008/08/27 11:03:10 matt Exp
 */

/*
 * GEMINI Timers
 */

/*
 * Based on i80321_timer.c and arch/arm/sa11x0/sa11x0_ost.c
 *
 * 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.
 *
 * Copyright (c) 2001, 2002 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
 *
 * 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 for the NetBSD Project by
 *      Wasabi Systems, Inc.
 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
 * 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: gemini_timer.c,v 1.7 2014/03/18 12:54:29 martin Exp $");

#include "opt_gemini.h"
#include "opt_cpuoptions.h"

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

#include <dev/clock_subr.h>

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

#include <arm/cpufunc.h>
#include <arm/pic/picvar.h>

#include <arm/gemini/gemini_reg.h>
#include <arm/gemini/gemini_timervar.h>
#include <arm/gemini/gemini_timervar.h>


static const uint32_t counts_per_usec = (GEMINI_TIMER_CLOCK_FREQ / 1000000);
static uint32_t counts_per_hz = ~0;

struct geminitmr_softc *clock_sc;
struct geminitmr_softc *stat_sc;
struct geminitmr_softc *ref_sc;
static uint32_t gemini_get_timecount(struct timecounter *);
static void timer_init(geminitmr_softc_t *, int, boolean_t, boolean_t);
static void timer_factors(geminitmr_softc_t *, int, boolean_t);

#ifdef GEMINI_TIMER_DEBUG
static void tfprint(uint, timer_factors_t *);
#endif

static struct timecounter gemini_timecounter = {
        .tc_get_timecount = gemini_get_timecount,
        .tc_counter_mask = 0xffffffff,
        .tc_frequency = GEMINI_TIMER_CLOCK_FREQ,
        .tc_name = "gpt",
        .tc_quality = 100,
        .tc_priv = NULL
};

static inline void
_timer_intr_dis(struct geminitmr_softc *sc)
{
        uint32_t r;

        r  = bus_space_read_4(sc->sc_iot, sc->sc_ioh, GEMINI_TIMER_INTRMASK);
        r |= GEMINI_TIMERn_INTRMASK(sc->sc_timerno);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, GEMINI_TIMER_INTRMASK, r);
}

static inline void
_timer_intr_enb(struct geminitmr_softc *sc)
{
        uint32_t r;

        r  = bus_space_read_4(sc->sc_iot, sc->sc_ioh, GEMINI_TIMER_INTRMASK);
        r &= ~TIMER_INTRMASK_TMnMATCH1(sc->sc_timerno);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, GEMINI_TIMER_INTRMASK, r);
}

static inline void
_timer_intr_clr(struct geminitmr_softc *sc)
{
        uint32_t r;
        int psw;

        psw = disable_interrupts(I32_bit);
        r  = bus_space_read_4(sc->sc_iot, sc->sc_ioh, GEMINI_TIMER_INTRSTATE);
        r &= ~GEMINI_TIMERn_INTRMASK(sc->sc_timerno);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, GEMINI_TIMER_INTRSTATE, r);
        restore_interrupts(psw);
}

static inline uint32_t
_timer_read(struct geminitmr_softc *sc)
{
        uint32_t r;

        r = bus_space_read_4(sc->sc_iot, sc->sc_ioh,
                GEMINI_TIMERn_COUNTER(sc->sc_timerno));

        return r;
}

static inline void
_timer_stop(struct geminitmr_softc *sc)
{
        uint32_t r;

        r  = bus_space_read_4(sc->sc_iot, sc->sc_ioh, GEMINI_TIMER_TMCR);
        r &= ~GEMINI_TIMER_TMnCR_MASK(sc->sc_timerno);
}

/*
 * note:
 *  This function assumes the timer is enabled.
 *  If the timer is disabled, GEMINI_TIMERn_COUNTER(n) will hold the value.
 */
static inline void
_timer_reload(struct geminitmr_softc *sc, uint32_t val)
{
        bus_space_write_4(sc->sc_iot, sc->sc_ioh,
                GEMINI_TIMERn_COUNTER(sc->sc_timerno), val);
}

static inline void
_timer_start(struct geminitmr_softc *sc)
{
        uint32_t r;
        uint n = sc->sc_timerno;
        timer_factors_t *tfp = &sc->sc_tf;

        /* set Counter, TmLoad, Match1, Match2 */
        bus_space_write_4(sc->sc_iot, sc->sc_ioh,
                GEMINI_TIMERn_COUNTER(n), tfp->tf_counter);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh,
                GEMINI_TIMERn_LOAD(n), tfp->tf_reload);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh,
                GEMINI_TIMERn_MATCH1(n), tfp->tf_match1);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh,
                GEMINI_TIMERn_MATCH2(n), tfp->tf_match2);

        /* set TmCR */
        r = bus_space_read_4(sc->sc_iot, sc->sc_ioh, GEMINI_TIMER_TMCR);
        r &= ~GEMINI_TIMER_TMnCR_MASK(n);
        r |= tfp->tf_tmcr & GEMINI_TIMER_TMnCR_MASK(n);
        bus_space_write_4(sc->sc_iot, sc->sc_ioh, GEMINI_TIMER_TMCR, r);

}

static uint32_t
gemini_get_timecount(struct timecounter *tc)
{
        uint32_t r;

        r = _timer_read(ref_sc);

        return -r;
}

int
clockintr(void *frame)
{
        struct geminitmr_softc *sc = clock_sc;

        _timer_intr_clr(sc);
        _timer_reload(sc, sc->sc_tf.tf_counter);
        hardclock(frame);
        if (clock_sc == stat_sc)
                statclock(frame);
        return 1;
}

int
statintr(void *frame)
{
        struct geminitmr_softc *sc = stat_sc;

        _timer_intr_clr(sc);
        _timer_reload(sc, sc->sc_tf.tf_counter);
        statclock(frame);
        return 1;
}

static void
timer_init(geminitmr_softc_t *sc, int schz, boolean_t autoload, boolean_t intr)
{
        int psw;

        psw = disable_interrupts(I32_bit);
        timer_factors(sc, schz, autoload);
        _timer_stop(sc);
        _timer_intr_dis(sc);
        _timer_intr_clr(sc);
        if (intr)
                _timer_intr_enb(sc);
        _timer_start(sc);
        restore_interrupts(psw);
}

void
gemini_microtime_init(void)
{
        if (ref_sc == NULL)
                panic("microtime reference timer was not configured.");
        timer_init(ref_sc, 0, TRUE, FALSE);
}

void
setstatclockrate(int schz)
{
        if (stat_sc == NULL)
                panic("Statistics timer was not configured.");
        if (stat_sc != clock_sc)
                timer_init(stat_sc, schz, FALSE, TRUE);
}

/*
 * clock_sc and stat_sc starts here
 * ref_sc is initialized already by obiotimer_attach
 */
void
cpu_initclocks(void)
{
        if (clock_sc == NULL)
                panic("Clock timer was not configured.");
        if (stat_sc == NULL)
                panic("Statistics timer was not configured.");
        if (ref_sc == NULL)
                panic("Microtime reference timer was not configured.");

        /*
         * We already have the timers running, but not generating interrupts.
         * In addition, we've set stathz and profhz.
         */
        printf("clock: hz=%d stathz=%d\n", hz, stathz);

        /*
         * The "cookie" parameter must be zero to pass the interrupt frame
         * through to hardclock() and statclock().
         */
        intr_establish(clock_sc->sc_intr, IPL_CLOCK, IST_LEVEL_HIGH,
                clockintr, 0);

        if (clock_sc != stat_sc)
                intr_establish(stat_sc->sc_intr, IPL_HIGH, IST_LEVEL_HIGH,
                        statintr, 0);

        timer_init(clock_sc, hz, FALSE, TRUE);
        if (clock_sc != stat_sc)
                timer_init(stat_sc, stathz, FALSE, TRUE);

        tc_init(&gemini_timecounter);
}

void
delay(u_int n)
{
        struct geminitmr_softc *sc = ref_sc;
        uint32_t cur, last, delta, usecs;

        if (sc == NULL)
                panic("The timer must be initialized sooner.");

        /*
         * This works by polling the timer and counting the
         * number of microseconds that go by.
         */
        last = _timer_read(sc);

        delta = usecs = 0;

        while (n > usecs) {
                cur = _timer_read(sc);

                /* Check to see if the timer has wrapped around. */
                if (last < cur)
                        delta += (last + (counts_per_hz - cur));
                else
                        delta += (last - cur);

                last = cur;

                if (delta >= counts_per_usec) {
                        usecs += delta / counts_per_usec;
                        delta %= counts_per_usec;
                }
        }
}

static void
timer_factors(
        geminitmr_softc_t *sc,
        int ints_per_sec,
        boolean_t autoload)
{
        timer_factors_t *tfp = &sc->sc_tf;
        uint n = sc->sc_timerno;
        const uint32_t us_per_sec = 1000000;

        /*
         * UPDOWN=0             (Down)
         * OFENABLE=0           (no Irpt on overflow)
         * CLOCK=0              (PCLK)
         * ENABLE=1
         */
        tfp->tf_tmcr = TIMER_TMCR_TMnENABLE(n);

        if (ints_per_sec == 0) {
                tfp->tf_counter = ~0U;
        } else {
                uint32_t count_freq;

                count_freq = GEMINI_TIMER_CLOCK_FREQ;
                count_freq /= ints_per_sec;
                tfp->tf_counter = count_freq;
        }
        tfp->tf_counts_per_usec = GEMINI_TIMER_CLOCK_FREQ / us_per_sec;

        if (autoload)
                tfp->tf_reload = tfp->tf_counter;       /* auto-reload */
        else
                tfp->tf_reload = 0;                     /* no-auto_reload */

        tfp->tf_match1 = 0;
        tfp->tf_match2 = 0;

#ifdef GEMINI_TIMER_DEBUG
        tfprint(sc->sc_timerno, tfp);
        Debugger();
#endif
}

#ifdef GEMINI_TIMER_DEBUG
void
tfprint(uint n, timer_factors_t *tfp)
{
        printf("%s: timer# %d\n", __FUNCTION__, n);
        printf("\ttf_counts_per_usec: %#x\n", tfp->tf_counts_per_usec);
        printf("\ttf_tmcr: %#x\n", tfp->tf_tmcr);
        printf("\ttf_counter: %#x\n", tfp->tf_counter);
        printf("\ttf_reload: %#x\n", tfp->tf_reload);
        printf("\ttf_match1: %#x\n", tfp->tf_match1);
        printf("\ttf_match2: %#x\n", tfp->tf_match2);
}
#endif