/* $NetBSD: sbwdog.c,v 1.15 2017/07/24 09:56:46 mrg Exp $ */

/*
 * Copyright (c) 2002 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Jason R. Thorpe and Simon Burge 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.
 */

/*
 * Watchdog timer support for the Broadcom BCM1250 processor.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: sbwdog.c,v 1.15 2017/07/24 09:56:46 mrg Exp $");

#include "locators.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/wdog.h>

#include <dev/sysmon/sysmonvar.h>

#include <mips/locore.h>

#include <mips/sibyte/include/sb1250_regs.h>
#include <mips/sibyte/include/sb1250_scd.h>
#include <mips/sibyte/dev/sbscdvar.h>

#include <evbmips/sbmips/systemsw.h>

#define SBWDOG_DEFAULT_PERIOD   5       /* Default to 5 seconds. */

struct sbwdog_softc {
        device_t sc_dev;
        struct sysmon_wdog sc_smw;
        u_long sc_addr;
        int sc_wdog_armed;
        int sc_wdog_period;
};

static int sbwdog_match(device_t, cfdata_t, void *);
static void sbwdog_attach(device_t, device_t, void *);
static int sbwdog_tickle(struct sysmon_wdog *);
static int sbwdog_setmode(struct sysmon_wdog *);
static void sbwdog_intr(void *, uint32_t, vaddr_t);

CFATTACH_DECL_NEW(sbwdog, sizeof(struct sbwdog_softc),
    sbwdog_match, sbwdog_attach, NULL, NULL);

#define READ_REG(rp)            (mips3_ld((register_t)(rp)))
#define WRITE_REG(rp, val)      (mips3_sd((register_t)(rp), (val)))

static int
sbwdog_match(device_t parent, cfdata_t cf, void *aux)
{
        struct sbscd_attach_args *sa = aux;

        if (sa->sa_locs.sa_type != SBSCD_DEVTYPE_WDOG)
                return (0);

        return (1);
}

static void
sbwdog_attach(device_t parent, device_t self, void *aux)
{
        struct sbwdog_softc *sc = device_private(self);
        struct sbscd_attach_args *sa = aux;

        sc->sc_dev = self;
        sc->sc_wdog_period = SBWDOG_DEFAULT_PERIOD;
        sc->sc_addr = MIPS_PHYS_TO_KSEG1(sa->sa_base + sa->sa_locs.sa_offset);

        aprint_normal(": %d second period\n", sc->sc_wdog_period);

        sc->sc_smw.smw_name = device_xname(sc->sc_dev);
        sc->sc_smw.smw_cookie = sc;
        sc->sc_smw.smw_setmode = sbwdog_setmode;
        sc->sc_smw.smw_tickle = sbwdog_tickle;
        sc->sc_smw.smw_period = sc->sc_wdog_period;

        if (sysmon_wdog_register(&sc->sc_smw) != 0)
                aprint_error_dev(self, "unable to register with sysmon\n");

        if (sa->sa_locs.sa_intr[0] != SBOBIOCF_INTR_DEFAULT)
                cpu_intr_establish(sa->sa_locs.sa_intr[0], IPL_HIGH,
                    sbwdog_intr, sc);
}

static int
sbwdog_tickle(struct sysmon_wdog *smw)
{
        struct sbwdog_softc *sc = smw->smw_cookie;

        WRITE_REG(sc->sc_addr + R_SCD_WDOG_CFG, M_SCD_WDOG_ENABLE);
        return (0);
}

static void
sbwdog_intr(void *v, uint32_t cause, vaddr_t pc)
{
        struct sbwdog_softc *sc = v;

        WRITE_REG(sc->sc_addr + R_SCD_WDOG_CFG, M_SCD_WDOG_ENABLE);
        WRITE_REG(sc->sc_addr + R_SCD_WDOG_CFG, 0);
        WRITE_REG(sc->sc_addr + R_SCD_WDOG_INIT,
            sc->sc_wdog_period * V_SCD_WDOG_FREQ);
        WRITE_REG(sc->sc_addr + R_SCD_WDOG_CFG, M_SCD_WDOG_ENABLE);
}


static int
sbwdog_setmode(struct sysmon_wdog *smw)
{
        struct sbwdog_softc *sc = smw->smw_cookie;

        if ((smw->smw_mode & WDOG_MODE_MASK) == WDOG_MODE_DISARMED) {
                if (sc->sc_wdog_armed)
                        WRITE_REG(sc->sc_addr + R_SCD_WDOG_CFG, 0);
        } else {
                if (smw->smw_period == WDOG_PERIOD_DEFAULT) {
                        sc->sc_wdog_period = SBWDOG_DEFAULT_PERIOD;
                        smw->smw_period = SBWDOG_DEFAULT_PERIOD;        /* XXX needed?? */
                } else if (smw->smw_period > 8) {
                        /* Maximum of 2^23 usec watchdog period. */
                        return (EINVAL);
                }
                sc->sc_wdog_period = smw->smw_period;
                sc->sc_wdog_armed = 1;
                WRITE_REG(sc->sc_addr + R_SCD_WDOG_INIT,
                    sc->sc_wdog_period * V_SCD_WDOG_FREQ);

                /* Watchdog is armed by tickling it. */
                sbwdog_tickle(smw);
        }
        return (0);
}