/*      $NetBSD: gfrtc_mainbus.c,v 1.3 2024/03/05 11:19:30 isaki Exp $  */

/*-
 * Copyright (c) 2023, 2024 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Nick Hudson and by Jason R. Thorpe.
 *
 * 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.
 *
 * 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: gfrtc_mainbus.c,v 1.3 2024/03/05 11:19:30 isaki Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/intr.h>
#include <sys/systm.h>

#include <machine/clockvar.h>

#include <virt68k/dev/mainbusvar.h>

#include <dev/goldfish/gfrtcvar.h>

static const struct device_compatible_entry compat_data[] = {
        { .compat = "google,goldfish-rtc",
          .value = CLOCK_NONE },

        { .compat = "netbsd,goldfish-rtc-hardclock",
          .value = CLOCK_HARDCLOCK },

        DEVICE_COMPAT_EOL
};

struct gfrtc_mainbus_softc {
        struct gfrtc_softc      sc_gfrtc;
        struct clock_attach_args sc_clock_args;
        uint64_t                sc_interval_ns;
        uint64_t                sc_alarm_time;
        void                    (*sc_handler)(struct clockframe *);
        struct evcnt *          sc_evcnt;
        void *                  sc_ih;
};

#define CLOCK_HANDLER()                                                 \
do {                                                                    \
        /* Clear the interrupt condition. */                            \
        gfrtc_clear_interrupt(&sc->sc_gfrtc);                           \
                                                                        \
        /* Get the next alarm set. */                                   \
        sc->sc_alarm_time += sc->sc_interval_ns;                        \
        gfrtc_set_alarm(&sc->sc_gfrtc, sc->sc_alarm_time);              \
                                                                        \
        /* Increment the counter and call the handler. */               \
        sc->sc_evcnt->ev_count++;                                       \
        sc->sc_handler((struct clockframe *)v);                         \
} while (/*CONSTCOND*/0)

static int
gfrtc_mainbus_hardclock(void *v)
{
        struct gfrtc_mainbus_softc *sc = clock_devices[CLOCK_HARDCLOCK];

        CLOCK_HANDLER();
        return 1;
}

static void *gfrtc_isrs[] = {
[CLOCK_HARDCLOCK]       =       gfrtc_mainbus_hardclock,
};

static void
gfrtc_mainbus_initclock(void *arg, unsigned int interval_us,
    struct evcnt *ev, void (*func)(struct clockframe *))
{
        struct gfrtc_mainbus_softc *sc = arg;

        sc->sc_interval_ns = (uint64_t)interval_us * 1000;
        sc->sc_handler = func;
        sc->sc_evcnt = ev;

        /* Enable the interrupt. */
        gfrtc_enable_interrupt(&sc->sc_gfrtc);

        /* Start the first alarm! */
        sc->sc_alarm_time = gfrtc_get_time(&sc->sc_gfrtc) + sc->sc_interval_ns;
        gfrtc_set_alarm(&sc->sc_gfrtc, sc->sc_alarm_time);
}

static int
gfrtc_mainbus_match(device_t parent, cfdata_t cf, void *aux)
{
        struct mainbus_attach_args * const ma = aux;

        return mainbus_compatible_match(ma, compat_data);
}

static void
gfrtc_mainbus_attach(device_t parent, device_t self, void *aux)
{
        struct gfrtc_mainbus_softc * const sc = device_private(self);
        struct mainbus_attach_args * const ma = aux;
        const struct device_compatible_entry *dce;
        char strbuf[INTR_STRING_BUFSIZE];

        sc->sc_gfrtc.sc_dev = self;
        sc->sc_gfrtc.sc_bst = ma->ma_st;
        if (bus_space_map(sc->sc_gfrtc.sc_bst, ma->ma_addr, ma->ma_size, 0,
                          &sc->sc_gfrtc.sc_bsh) != 0) {
                aprint_error(": couldn't map registers\n");
                return;
        }

        dce = mainbus_compatible_lookup(ma, compat_data);
        KASSERT(dce != NULL);

        gfrtc_attach(&sc->sc_gfrtc, (dce->value == CLOCK_NONE));

        switch (dce->value) {
        case CLOCK_HARDCLOCK:
                /*
                 * We are the one of the clock interrupts.
                 */
                sc->sc_ih = intr_establish(gfrtc_isrs[(int)dce->value],
                    NULL, ma->ma_irq, IPL_SCHED, 0);
                KASSERT(sc->sc_ih != NULL);
                aprint_normal_dev(self, "%s interrupting at %s\n",
                    clock_name((int)dce->value),
                    intr_string(sc->sc_ih, strbuf, sizeof(strbuf)));
                sc->sc_clock_args.ca_initfunc = gfrtc_mainbus_initclock;
                sc->sc_clock_args.ca_arg = sc;
                sc->sc_clock_args.ca_which = (int)dce->value;
                clock_attach(self, &sc->sc_clock_args, gfrtc_delay);
                break;

        default:
                break;
        }
}

CFATTACH_DECL_NEW(gfrtc_mainbus, sizeof(struct gfrtc_mainbus_softc),
        gfrtc_mainbus_match, gfrtc_mainbus_attach, NULL, NULL);