/*      $OpenBSD: aplmbox.c,v 1.6 2023/07/23 11:17:49 kettenis Exp $    */
/*
 * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
 *
 * 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/systm.h>
#include <sys/device.h>
#include <sys/malloc.h>

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

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_misc.h>
#include <dev/ofw/ofw_power.h>
#include <dev/ofw/fdt.h>

#include <arm64/dev/aplmbox.h>

#define MBOX_A2I_CTRL           0x110
#define  MBOX_A2I_CTRL_FULL     (1 << 16)
#define MBOX_I2A_CTRL           0x114
#define  MBOX_I2A_CTRL_EMPTY    (1 << 17)
#define MBOX_A2I_SEND0          0x800
#define MBOX_A2I_SEND1          0x808
#define MBOX_I2A_RECV0          0x830
#define MBOX_I2A_RECV1          0x838

#define HREAD4(sc, reg)                                                 \
        (bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
#define HREAD8(sc, reg)                                                 \
        (bus_space_read_8((sc)->sc_iot, (sc)->sc_ioh, (reg)))
#define HWRITE4(sc, reg, val)                                           \
        bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))
#define HWRITE8(sc, reg, val)                                           \
        bus_space_write_8((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))

struct aplmbox_softc {
        struct device           sc_dev;
        bus_space_tag_t         sc_iot;
        bus_space_handle_t      sc_ioh;

        void                    *sc_ih;
        void                    (*sc_rx_callback)(void *);
        void                    *sc_rx_arg;

        struct mbox_device      sc_md;
};

int     aplmbox_match(struct device *, void *, void *);
void    aplmbox_attach(struct device *, struct device *, void *);

const struct cfattach aplmbox_ca = {
        sizeof (struct aplmbox_softc), aplmbox_match, aplmbox_attach
};

struct cfdriver aplmbox_cd = {
        NULL, "aplmbox", DV_DULL
};

int     aplmbox_intr(void *);
void    *aplmbox_channel(void *, uint32_t *, struct mbox_client *);
int     aplmbox_send(void *, const void *, size_t);
int     aplmbox_recv(void *, void *, size_t);

int
aplmbox_match(struct device *parent, void *match, void *aux)
{
        struct fdt_attach_args *faa = aux;

        return (OF_is_compatible(faa->fa_node, "apple,asc-mailbox") ||
            OF_is_compatible(faa->fa_node, "apple,asc-mailbox-v4"));
}

void
aplmbox_attach(struct device *parent, struct device *self, void *aux)
{
        struct aplmbox_softc *sc = (struct aplmbox_softc *)self;
        struct fdt_attach_args *faa = aux;
        int idx;

        if (faa->fa_nreg < 1) {
                printf(": no registers\n");
                return;
        }

        sc->sc_iot = faa->fa_iot;
        if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
            faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
                printf(": can't map registers\n");
                return;
        }

        idx = OF_getindex(faa->fa_node, "recv-not-empty", "interrupt-names");
        if (idx > 0) {
                sc->sc_ih = fdt_intr_establish_idx(faa->fa_node, idx, IPL_BIO,
                    aplmbox_intr, sc, sc->sc_dev.dv_xname);
        }

        printf("\n");

        power_domain_enable(faa->fa_node);

        sc->sc_md.md_node = faa->fa_node;
        sc->sc_md.md_cookie = sc;
        sc->sc_md.md_channel = aplmbox_channel;
        sc->sc_md.md_send = aplmbox_send;
        sc->sc_md.md_recv = aplmbox_recv;
        mbox_register(&sc->sc_md);
}

int
aplmbox_intr(void *arg)
{
        struct aplmbox_softc *sc = arg;
        uint32_t ctrl;

        ctrl = HREAD4(sc, MBOX_I2A_CTRL);
        if (ctrl & MBOX_I2A_CTRL_EMPTY)
                return 0;

        if (sc->sc_rx_callback) {
                sc->sc_rx_callback(sc->sc_rx_arg);
        } else {
                printf("%s: 0x%016llx 0x%016llx\n", sc->sc_dev.dv_xname,
                    HREAD8(sc, MBOX_I2A_RECV0), HREAD8(sc, MBOX_I2A_RECV1));
        }

        return 1;
}

void *
aplmbox_channel(void *cookie, uint32_t *cells, struct mbox_client *mc)
{
        struct aplmbox_softc *sc = cookie;

        if (mc) {
                sc->sc_rx_callback = mc->mc_rx_callback;
                sc->sc_rx_arg = mc->mc_rx_arg;

                if (mc->mc_flags & MC_WAKEUP)
                        intr_set_wakeup(sc->sc_ih);
        }

        return sc;
}

int
aplmbox_send(void *cookie, const void *data, size_t len)
{
        struct aplmbox_softc *sc = cookie;
        const struct aplmbox_msg *msg = data;
        uint32_t ctrl;

        if (len != sizeof(struct aplmbox_msg))
                return EINVAL;

        ctrl = HREAD4(sc, MBOX_A2I_CTRL);
        if (ctrl & MBOX_A2I_CTRL_FULL)
                return EBUSY;

        HWRITE8(sc, MBOX_A2I_SEND0, msg->data0);
        HWRITE8(sc, MBOX_A2I_SEND1, msg->data1);

        return 0;
}

int
aplmbox_recv(void *cookie, void *data, size_t len)
{
        struct aplmbox_softc *sc = cookie;
        struct aplmbox_msg *msg = data;
        uint32_t ctrl;

        if (len != sizeof(struct aplmbox_msg))
                return EINVAL;

        ctrl = HREAD4(sc, MBOX_I2A_CTRL);
        if (ctrl & MBOX_I2A_CTRL_EMPTY)
                return EWOULDBLOCK;

        msg->data0 = HREAD8(sc, MBOX_I2A_RECV0);
        msg->data1 = HREAD8(sc, MBOX_I2A_RECV1);

        return 0;
}