/*      $OpenBSD: mtintc.c,v 1.1 2025/01/30 00:26:44 hastings Exp $     */
/*
 * Copyright (c) 2025 James Hastings <hastings@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/device.h>
#include <sys/malloc.h>
#include <sys/systm.h>

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

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

struct mtintc_softc {
        struct device                   sc_dev;
        bus_space_tag_t                 sc_iot;
        bus_space_handle_t              sc_ioh;
        bus_size_t                      sc_ios;

        int                             sc_nirq;
        uint32_t                        *sc_irq_cfg;

        struct interrupt_controller     sc_ic;
};

int     mtintc_match(struct device *, void *, void *);
void    mtintc_attach(struct device *, struct device *, void *);
int     mtintc_activate(struct device *, int);

void    *mtintc_establish_fdt(void *, int *, int, struct cpu_info *,
            int (*)(void *), void *, char *);

const struct cfattach mtintc_ca = {
        sizeof(struct mtintc_softc), mtintc_match, mtintc_attach, NULL,
        mtintc_activate
};

struct cfdriver mtintc_cd = {
        NULL, "mtintc", DV_DULL
};

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

        return OF_is_compatible(faa->fa_node, "mediatek,mt6577-sysirq");
}

void
mtintc_attach(struct device *parent, struct device *self, void *aux)
{
        struct mtintc_softc *sc = (struct mtintc_softc *)self;
        struct fdt_attach_args *faa = aux;

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

        sc->sc_iot = faa->fa_iot;
        sc->sc_ios = faa->fa_reg[0].size;
        if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
            sc->sc_ios, 0, &sc->sc_ioh))
                panic("%s: bus_space_map failed!", __func__);

        sc->sc_nirq = sc->sc_ios * 8;
        sc->sc_irq_cfg = malloc(sc->sc_ios, M_DEVBUF, M_WAITOK);

        sc->sc_ic.ic_node = faa->fa_node;
        sc->sc_ic.ic_cookie = sc;
        sc->sc_ic.ic_establish = mtintc_establish_fdt;

        printf(" nirq %d\n", sc->sc_nirq);

        fdt_intr_register(&sc->sc_ic);
}

int
mtintc_activate(struct device *self, int act)
{
        struct mtintc_softc *sc = (struct mtintc_softc *)self;

        switch (act) {
        case DVACT_SUSPEND:
                bus_space_read_region_4(sc->sc_iot, sc->sc_ioh, 0,
                    sc->sc_irq_cfg, sc->sc_ios / sizeof(uint32_t));
                break;
        case DVACT_RESUME:
                bus_space_write_region_4(sc->sc_iot, sc->sc_ioh, 0,
                    sc->sc_irq_cfg, sc->sc_ios / sizeof(uint32_t));
                break;
        }

        return 0;
}

void
mtintc_invert(struct mtintc_softc *sc, int irq)
{
        int reg = (irq / 32) * 4;
        int bit = (irq % 32);

        bus_space_write_4(sc->sc_iot, sc->sc_ioh, reg,
            bus_space_read_4(sc->sc_iot, sc->sc_ioh, reg) | 1U << bit);
}

void *
mtintc_establish_fdt(void *cookie, int *cells, int level,
    struct cpu_info *ci, int (*func)(void *), void *arg, char *name)
{
        struct mtintc_softc *sc = cookie;
        int irq = cells[1];
        int flags = cells[2];

        KASSERT(cells[0] == 0);
        KASSERT(irq >= 0 && irq < sc->sc_nirq);

#ifdef DEBUG_INTC
        printf("%s: irq %d level %d flags 0x%x [%s]\n", __func__, irq, level,
            flags, name);
#endif

        if (flags & 0xa)
                mtintc_invert(sc, irq);

        return fdt_intr_parent_establish(&sc->sc_ic, cells, level, ci, func,
            arg, name);
}