/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2013 Rui Paulo <rpaulo@FreeBSD.org>
 * All rights reserved.
 *
 * 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 AUTHOR ``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 AUTHOR 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/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/rman.h>
#include <sys/timeet.h>
#include <sys/timetc.h>
#include <sys/watchdog.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/frame.h>
#include <machine/intr.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include <machine/bus.h>

#include <arm/ti/ti_mbox.h>
#include <arm/ti/ti_sysc.h>

#include "mbox_if.h"

#ifdef DEBUG
#define DPRINTF(fmt, ...)       do {    \
        printf("%s: ", __func__);       \
        printf(fmt, __VA_ARGS__);       \
} while (0)
#else
#define DPRINTF(fmt, ...)
#endif

static device_probe_t           ti_mbox_probe;
static device_attach_t          ti_mbox_attach;
static device_detach_t          ti_mbox_detach;
static void                     ti_mbox_intr(void *);
static int                      ti_mbox_read(device_t, int, uint32_t *);
static int                      ti_mbox_write(device_t, int, uint32_t);

struct ti_mbox_softc {
        struct mtx              sc_mtx;
        struct resource         *sc_mem_res;
        struct resource         *sc_irq_res;
        void                    *sc_intr;
        bus_space_tag_t         sc_bt;
        bus_space_handle_t      sc_bh;
};

#define TI_MBOX_LOCK(sc)        mtx_lock(&(sc)->sc_mtx)
#define TI_MBOX_UNLOCK(sc)      mtx_unlock(&(sc)->sc_mtx)

static device_method_t ti_mbox_methods[] = {
        DEVMETHOD(device_probe,         ti_mbox_probe),
        DEVMETHOD(device_attach,        ti_mbox_attach),
        DEVMETHOD(device_detach,        ti_mbox_detach),

        DEVMETHOD(mbox_read,            ti_mbox_read),
        DEVMETHOD(mbox_write,           ti_mbox_write),

        DEVMETHOD_END
};

static driver_t ti_mbox_driver = {
        "ti_mbox",
        ti_mbox_methods,
        sizeof(struct ti_mbox_softc)
};

DRIVER_MODULE(ti_mbox, simplebus, ti_mbox_driver, 0, 0);
MODULE_DEPEND(ti_mbox, ti_sysc, 1, 1, 1);

static __inline uint32_t
ti_mbox_reg_read(struct ti_mbox_softc *sc, uint16_t reg)
{
        return (bus_space_read_4(sc->sc_bt, sc->sc_bh, reg));
}

static __inline void
ti_mbox_reg_write(struct ti_mbox_softc *sc, uint16_t reg, uint32_t val)
{
        bus_space_write_4(sc->sc_bt, sc->sc_bh, reg, val);
}

static int
ti_mbox_probe(device_t dev)
{

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        if (ofw_bus_is_compatible(dev, "ti,omap4-mailbox")) {
                device_set_desc(dev, "TI System Mailbox");
                return (BUS_PROBE_DEFAULT);
        }

        return (ENXIO);
}

static int
ti_mbox_attach(device_t dev)
{
        struct ti_mbox_softc *sc;
        int rid, delay, chan;
        uint32_t rev, sysconfig;

        if (ti_sysc_clock_enable(device_get_parent(dev)) != 0) {
                device_printf(dev, "could not enable MBOX clock\n");
                return (ENXIO);
        }

        sc = device_get_softc(dev);
        rid = 0;
        mtx_init(&sc->sc_mtx, "TI mbox", NULL, MTX_DEF);
        sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
            RF_ACTIVE);
        if (sc->sc_mem_res == NULL) {
                device_printf(dev, "could not allocate memory resource\n");
                return (ENXIO);
        }
        sc->sc_bt = rman_get_bustag(sc->sc_mem_res);
        sc->sc_bh = rman_get_bushandle(sc->sc_mem_res);
        rid = 0;
        sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
            RF_ACTIVE);
        if (sc->sc_irq_res == NULL) {
                device_printf(dev, "could not allocate interrupt resource\n");
                ti_mbox_detach(dev);
                return (ENXIO);
        }
        if (bus_setup_intr(dev, sc->sc_irq_res, INTR_MPSAFE | INTR_TYPE_MISC,
            NULL, ti_mbox_intr, sc, &sc->sc_intr) != 0) {
                device_printf(dev, "unable to setup the interrupt handler\n");
                ti_mbox_detach(dev);
                return (ENXIO);
        }
        /*
         * Reset the controller.
         */
        sysconfig = ti_mbox_reg_read(sc, TI_MBOX_SYSCONFIG);
        DPRINTF("initial sysconfig %d\n", sysconfig);
        sysconfig |= TI_MBOX_SYSCONFIG_SOFTRST;
        ti_mbox_reg_write(sc, TI_MBOX_SYSCONFIG, sysconfig);
        delay = 100;
        while (ti_mbox_reg_read(sc, TI_MBOX_SYSCONFIG) & 
            TI_MBOX_SYSCONFIG_SOFTRST) {
                delay--;
                DELAY(10);
        }
        if (delay == 0) {
                device_printf(dev, "controller reset failed\n");
                ti_mbox_detach(dev);
                return (ENXIO);
        }
        /*
         * Enable smart idle mode.
         */
        ti_mbox_reg_write(sc, TI_MBOX_SYSCONFIG,
            ti_mbox_reg_read(sc, TI_MBOX_SYSCONFIG) | TI_MBOX_SYSCONFIG_SMARTIDLE);
        rev = ti_mbox_reg_read(sc,
            ti_sysc_get_rev_address_offset_host(device_get_parent(dev)));
        DPRINTF("rev %d\n", rev);
        device_printf(dev, "revision %d.%d\n", (rev >> 8) & 0x4, rev & 0x40);
        /*
         * Enable message interrupts.
         */
        for (chan = 0; chan < 8; chan++)
                ti_mbox_reg_write(sc, TI_MBOX_IRQENABLE_SET(chan), 1);

        return (0);
}

static int
ti_mbox_detach(device_t dev)
{
        struct ti_mbox_softc *sc;

        sc = device_get_softc(dev);
        if (sc->sc_intr)
                bus_teardown_intr(dev, sc->sc_irq_res, sc->sc_intr);
        if (sc->sc_irq_res)
                bus_release_resource(dev, SYS_RES_IRQ, rman_get_rid(sc->sc_irq_res),
                    sc->sc_irq_res);
        if (sc->sc_mem_res)
                bus_release_resource(dev, SYS_RES_MEMORY, rman_get_rid(sc->sc_mem_res),
                    sc->sc_mem_res);

        return (0);
}

static void
ti_mbox_intr(void *arg)
{
        DPRINTF("interrupt %p", arg);
}

static int
ti_mbox_read(device_t dev, int chan, uint32_t *data)
{
        struct ti_mbox_softc *sc;

        if (chan < 0 || chan > 7)
                return (EINVAL);
        sc = device_get_softc(dev);

        return (ti_mbox_reg_read(sc, TI_MBOX_MESSAGE(chan)));
}

static int
ti_mbox_write(device_t dev, int chan, uint32_t data)
{
        int limit = 500;
        struct ti_mbox_softc *sc;

        if (chan < 0 || chan > 7)
                return (EINVAL);
        sc = device_get_softc(dev);
        TI_MBOX_LOCK(sc);
        /* XXX implement interrupt method */
        while (ti_mbox_reg_read(sc, TI_MBOX_FIFOSTATUS(chan)) == 1 && 
            limit--) {
                DELAY(10);
        }
        if (limit == 0) {
                device_printf(dev, "FIFOSTAUS%d stuck\n", chan);
                TI_MBOX_UNLOCK(sc);
                return (EAGAIN);
        }
        ti_mbox_reg_write(sc, TI_MBOX_MESSAGE(chan), data);

        return (0);
}