/*      $OpenBSD: bbc.c,v 1.4 2021/10/24 17:05:03 mpi Exp $     */

/*
 * Copyright (c) 2007 Mark Kettenis
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

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

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

#ifdef DDB
#include <machine/db_machdep.h>
#endif

#include <sparc64/dev/ebusreg.h>
#include <sparc64/dev/ebusvar.h>

/* Agent ID */
#define BBC_AID                 0x00000

/* Watchdog Action */
#define BBC_WATCHDOG_ACTION     0x00004

/* Perform system reset when watchdog timer expires. */
#define BBC_WATCHDOG_RESET      0x01

/* Soft_XIR_GEN */
#define BBC_SOFT_XIR_GEN        0x00007

struct bbc_softc {
        struct device           sc_dv;
        bus_space_tag_t         sc_iot;
        bus_space_handle_t      sc_ioh;

        int                     sc_aid;
};

int     bbc_match(struct device *, void *, void *);
void    bbc_attach(struct device *, struct device *, void *);

const struct cfattach bbc_ca = {
        sizeof(struct bbc_softc), bbc_match, bbc_attach
};

struct cfdriver bbc_cd = {
        NULL, "bbc", DV_DULL
};

#ifdef DDB
void    bbc_xir(void *, int);
#endif

int
bbc_match(struct device *parent, void *cf, void *aux)
{
        struct ebus_attach_args *ea = aux;

        if (strcmp("bbc", ea->ea_name) == 0)
                return (1);
        return (0);
}

void
bbc_attach(struct device *parent, struct device *self, void *aux)
{
        struct bbc_softc *sc = (void *)self;
        struct ebus_attach_args *ea = aux;

        /* Use prom address if available, otherwise map it. */
        if (ea->ea_nvaddrs) {
                if (bus_space_map(ea->ea_memtag, ea->ea_vaddrs[0], 0,
                    BUS_SPACE_MAP_PROMADDRESS, &sc->sc_ioh)) {
                        printf(": can't map PROM register space\n");
                        return;
                }
                sc->sc_iot = ea->ea_memtag;
        } else if (ebus_bus_map(ea->ea_iotag, 0,
            EBUS_PADDR_FROM_REG(&ea->ea_regs[0]),
            ea->ea_regs[0].size, 0, 0, &sc->sc_ioh) == 0) {
                sc->sc_iot = ea->ea_iotag;
        } else if (ebus_bus_map(ea->ea_memtag, 0,
            EBUS_PADDR_FROM_REG(&ea->ea_regs[0]),
            ea->ea_regs[0].size, 0, 0, &sc->sc_ioh) == 0) {
                sc->sc_iot = ea->ea_memtag;
        } else {
                printf(": can't map register space\n");
                return;
        }

        sc->sc_aid = bus_space_read_1(sc->sc_iot, sc->sc_ioh, BBC_AID);
        printf(": AID 0x%02x\n", sc->sc_aid);

        /*
         * Make sure we actually reset the system when the watchdog
         * timer expires.
         */
        bus_space_write_1(sc->sc_iot, sc->sc_ioh,
            BBC_WATCHDOG_ACTION, BBC_WATCHDOG_RESET);

#ifdef DDB
        db_register_xir(bbc_xir, sc);
#endif
}

#ifdef DDB
void
bbc_xir(void *arg, int cpu)
{
        struct bbc_softc *sc = arg;

        /* Redirect a request to reset all processors to Processor 0. */
        if (cpu == -1)
                cpu = 0;

        /* Check whether we're handling the requested processor. */
        if ((cpu & ~0x7) != sc->sc_aid)
                return;

        bus_space_write_1(sc->sc_iot, sc->sc_ioh,
            BBC_SOFT_XIR_GEN, 1 << (cpu & 0x7));
}
#endif