/*-
 * Copyright (c) 2019 Juniper Networks, Inc.
 * Copyright (c) 2019 Semihalf.
 * 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/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/systm.h>

#include <dev/fdt/simplebus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/ofw/ofw_bus.h>

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

#include "mdio_if.h"

MALLOC_DEFINE(M_BRCM_IPROC_NEXUS, "Broadcom IPROC MDIO NEXUS",
    "Broadcom IPROC MDIO NEXUS dynamic memory");

struct brcm_mdionexus_softc {
        struct simplebus_softc simplebus_sc;
        uint32_t mux_id;
};

/* OFW bus interface */
struct brcm_mdionexus_ofw_devinfo {
        struct ofw_bus_devinfo  di_dinfo;
        struct resource_list    di_rl;
};

static device_probe_t brcm_mdionexus_fdt_probe;
static device_attach_t brcm_mdionexus_fdt_attach;

static const struct ofw_bus_devinfo * brcm_mdionexus_ofw_get_devinfo(device_t,
    device_t);
static int brcm_mdionexus_mdio_readreg(device_t, int, int);
static int brcm_mdionexus_mdio_writereg(device_t, int, int, int);

static device_method_t brcm_mdionexus_fdt_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         brcm_mdionexus_fdt_probe),
        DEVMETHOD(device_attach,        brcm_mdionexus_fdt_attach),

        /* Bus interface */
        DEVMETHOD(bus_alloc_resource,           bus_generic_alloc_resource),
        DEVMETHOD(bus_release_resource,         bus_generic_release_resource),
        DEVMETHOD(bus_activate_resource,        bus_generic_activate_resource),

        /* ofw_bus interface */
        DEVMETHOD(ofw_bus_get_devinfo,  brcm_mdionexus_ofw_get_devinfo),
        DEVMETHOD(ofw_bus_get_compat,   ofw_bus_gen_get_compat),
        DEVMETHOD(ofw_bus_get_model,    ofw_bus_gen_get_model),
        DEVMETHOD(ofw_bus_get_name,     ofw_bus_gen_get_name),
        DEVMETHOD(ofw_bus_get_node,     ofw_bus_gen_get_node),
        DEVMETHOD(ofw_bus_get_type,     ofw_bus_gen_get_type),

        /* MDIO interface */
        /* MDIO interface */
        DEVMETHOD(mdio_readreg,         brcm_mdionexus_mdio_readreg),
        DEVMETHOD(mdio_writereg,        brcm_mdionexus_mdio_writereg),

        DEVMETHOD_END
};

DEFINE_CLASS_0(brcm_mdionexus, brcm_mdionexus_fdt_driver, brcm_mdionexus_fdt_methods,
    sizeof(struct brcm_mdionexus_softc));

static driver_t brcm_mdionexus_driver = {
        "brcm_mdionexus",
        brcm_mdionexus_fdt_methods,
        sizeof(struct brcm_mdionexus_softc)
};

EARLY_DRIVER_MODULE(brcm_mdionexus, brcm_iproc_mdio, brcm_mdionexus_driver,
    NULL, NULL, BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);

static int brcm_mdionexus_ofw_bus_attach(device_t);

static int
brcm_mdionexus_mdio_readreg(device_t dev, int phy, int reg)
{
        struct brcm_mdionexus_softc *sc;

        sc = device_get_softc(dev);

        return (MDIO_READREG_MUX(device_get_parent(dev),
                        sc->mux_id, phy, reg));
}

static int
brcm_mdionexus_mdio_writereg(device_t dev, int phy, int reg, int val)
{
        struct brcm_mdionexus_softc *sc;

        sc = device_get_softc(dev);

        return (MDIO_WRITEREG_MUX(device_get_parent(dev),
                        sc->mux_id, phy, reg, val));
}

static __inline void
get_addr_size_cells(phandle_t node, pcell_t *addr_cells, pcell_t *size_cells)
{

        *addr_cells = 2;
        /* Find address cells if present */
        OF_getencprop(node, "#address-cells", addr_cells, sizeof(*addr_cells));

        *size_cells = 2;
        /* Find size cells if present */
        OF_getencprop(node, "#size-cells", size_cells, sizeof(*size_cells));
}

static int
brcm_mdionexus_fdt_probe(device_t dev)
{

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);
        device_set_desc(dev, "Broadcom MDIO nexus");
        return (BUS_PROBE_SPECIFIC);
}

static int
brcm_mdionexus_fdt_attach(device_t dev)
{
        struct brcm_mdionexus_softc *sc;
        int err;
        pcell_t addr_cells, size_cells, buf[2];
        phandle_t node;

        sc = device_get_softc(dev);

        node = ofw_bus_get_node(dev);
        get_addr_size_cells(node, &addr_cells, &size_cells);
        if ((addr_cells != 1) || (size_cells != 0)) {
                device_printf(dev, "Only addr_cells=1 and size_cells=0 are supported\n");
                return (EINVAL);
        }

        if (OF_getencprop(node, "reg", buf, sizeof(pcell_t)) < 0)
                return (ENXIO);

        sc->mux_id = buf[0];

        err = brcm_mdionexus_ofw_bus_attach(dev);
        if (err != 0)
                return (err);

        bus_attach_children(dev);
        return (0);
}

static const struct ofw_bus_devinfo *
brcm_mdionexus_ofw_get_devinfo(device_t bus __unused, device_t child)
{
        struct brcm_mdionexus_ofw_devinfo *di;

        di = device_get_ivars(child);
        return (&di->di_dinfo);
}

static int
brcm_mdionexus_ofw_bus_attach(device_t dev)
{
        struct simplebus_softc *sc;
        struct brcm_mdionexus_ofw_devinfo *di;
        device_t child;
        phandle_t parent, node;

        parent = ofw_bus_get_node(dev);
        simplebus_init(dev, parent);

        sc = (struct simplebus_softc *)device_get_softc(dev);

        /* Iterate through all bus subordinates */
        for (node = OF_child(parent); node > 0; node = OF_peer(node)) {
                /* Allocate and populate devinfo. */
                di = malloc(sizeof(*di), M_BRCM_IPROC_NEXUS, M_WAITOK | M_ZERO);
                if (ofw_bus_gen_setup_devinfo(&di->di_dinfo, node) != 0) {
                        free(di, M_BRCM_IPROC_NEXUS);
                        continue;
                }

                /* Initialize and populate resource list. */
                resource_list_init(&di->di_rl);
                ofw_bus_reg_to_rl(dev, node, sc->acells, sc->scells,
                    &di->di_rl);
                ofw_bus_intr_to_rl(dev, node, &di->di_rl, NULL);

                /* Add newbus device for this FDT node */
                child = device_add_child(dev, NULL, DEVICE_UNIT_ANY);
                if (child == NULL) {
                        resource_list_free(&di->di_rl);
                        ofw_bus_gen_destroy_devinfo(&di->di_dinfo);
                        free(di, M_BRCM_IPROC_NEXUS);
                        continue;
                }

                device_set_ivars(child, di);
        }

        return (0);
}