/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2022 Beckhoff Automation GmbH & Co. KG
 *
 * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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/cdefs.h>

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <machine/bus.h>

#include <dev/fdt/simplebus.h>

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

struct ofw_firmware_softc {
        struct simplebus_softc  sc;
        device_t                dev;
};

static struct simplebus_devinfo *
ofw_firmware_setup_dinfo(device_t dev, phandle_t node,
    struct simplebus_devinfo *di)
{
        struct simplebus_softc *sc;
        struct simplebus_devinfo *ndi;

        sc = device_get_softc(dev);
        if (di == NULL)
                ndi = malloc(sizeof(*ndi), M_DEVBUF, M_WAITOK | M_ZERO);
        else
                ndi = di;
        if (ofw_bus_gen_setup_devinfo(&ndi->obdinfo, node) != 0) {
                if (di == NULL)
                        free(ndi, M_DEVBUF);
                return (NULL);
        }

        /* reg resources is from the parent but interrupts is on the node itself */
        resource_list_init(&ndi->rl);
        ofw_bus_reg_to_rl(dev, OF_parent(node), sc->acells, sc->scells, &ndi->rl);
        ofw_bus_intr_to_rl(dev, node, &ndi->rl, NULL);

        return (ndi);
}

static device_t
ofw_firmware_add_device(device_t dev, phandle_t node, u_int order,
    const char *name, int unit, struct simplebus_devinfo *di)
{
        struct simplebus_devinfo *ndi;
        device_t cdev;

        if ((ndi = ofw_firmware_setup_dinfo(dev, node, di)) == NULL)
                return (NULL);
        cdev = device_add_child_ordered(dev, order, name, unit);
        if (cdev == NULL) {
                device_printf(dev, "<%s>: device_add_child failed\n",
                    ndi->obdinfo.obd_name);
                resource_list_free(&ndi->rl);
                ofw_bus_gen_destroy_devinfo(&ndi->obdinfo);
                if (di == NULL)
                        free(ndi, M_DEVBUF);
                return (NULL);
        }
        device_set_ivars(cdev, ndi);

        return(cdev);
}

static int
ofw_firmware_probe(device_t dev)
{
        const char *name, *compat;
        phandle_t root, parent;

        name = ofw_bus_get_name(dev);
        if (name == NULL || strcmp(name, "firmware") != 0)
                return (ENXIO);
        parent = OF_parent(ofw_bus_get_node(dev));
        root = OF_finddevice("/");
        if (parent != root)
                return (ENXIO);
        compat = ofw_bus_get_compat(dev);
        if (compat != NULL)
                return (ENXIO);

        device_set_desc(dev, "OFW Firmware Group");
        return (BUS_PROBE_GENERIC);
}

static int
ofw_firmware_attach(device_t dev)
{
        struct ofw_firmware_softc *sc;
        phandle_t node, child;
        device_t cdev;

        sc = device_get_softc(dev);
        sc->dev = dev;
        node = ofw_bus_get_node(dev);

        if (OF_getencprop(node, "#address-cells", &sc->sc.acells,
            sizeof(sc->sc.acells)) == -1) {
                if (OF_getencprop(OF_parent(node), "#address-cells", &sc->sc.acells,
                    sizeof(sc->sc.acells)) == -1) {
                        sc->sc.acells = 2;
                }
        }
        if (OF_getencprop(node, "#size-cells", &sc->sc.scells,
            sizeof(sc->sc.scells)) == -1) {
                if (OF_getencprop(OF_parent(node), "#size-cells", &sc->sc.scells,
                    sizeof(sc->sc.scells)) == -1) {
                        sc->sc.scells = 1;
                }
        }

        for (child = OF_child(node); child != 0; child = OF_peer(child)) {
                cdev = ofw_firmware_add_device(dev, child, 0, NULL, -1, NULL);
                if (cdev != NULL)
                        device_probe_and_attach(cdev);
        }

        bus_attach_children(dev);
        return (0);
}

static device_method_t ofw_firmware_methods[] = {
        /* device_if */
        DEVMETHOD(device_probe,         ofw_firmware_probe),
        DEVMETHOD(device_attach,        ofw_firmware_attach),

        DEVMETHOD_END
};

DEFINE_CLASS_1(ofw_firmware, ofw_firmware_driver, ofw_firmware_methods,
  sizeof(struct ofw_firmware_softc), simplebus_driver);

EARLY_DRIVER_MODULE(ofw_firmware, simplebus, ofw_firmware_driver, 0, 0,
    BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
MODULE_VERSION(ofw_firmware, 1);