/*-
 * Copyright (c) 2016 Justin Hibbits
 * 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 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/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/resource.h>
#include <sys/socket.h>

#include <machine/bus.h>

#include <net/if.h>
#include <net/if_media.h>
#include <net/if_types.h>
#include <net/if_var.h>

#include <dev/mii/mii.h>
#include <dev/mii/miivar.h>

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

#include <contrib/ncsw/inc/Peripherals/fm_ext.h>

#include "fman.h"
#include "miibus_if.h"

#define MDIO_LOCK()     mtx_lock(&sc->sc_lock)
#define MDIO_UNLOCK()   mtx_unlock(&sc->sc_lock)
#define MDIO_WRITE4(sc,r,v) \
        bus_space_write_4(&bs_be_tag, sc->sc_handle, sc->sc_offset + r, v)
#define MDIO_READ4(sc, r) \
        bus_space_read_4(&bs_be_tag, sc->sc_handle, sc->sc_offset + r)

#define MDIO_MIIMCFG    0x0
#define MDIO_MIIMCOM    0x4
#define   MIIMCOM_SCAN_CYCLE      0x00000002
#define   MIIMCOM_READ_CYCLE      0x00000001
#define MDIO_MIIMADD    0x8
#define MDIO_MIIMCON    0xc
#define MDIO_MIIMSTAT   0x10
#define MDIO_MIIMIND    0x14
#define   MIIMIND_BUSY    0x1

static int pqmdio_fdt_probe(device_t dev);
static int pqmdio_fdt_attach(device_t dev);
static int pqmdio_detach(device_t dev);
static int pqmdio_miibus_readreg(device_t dev, int phy, int reg);
static int pqmdio_miibus_writereg(device_t dev, int phy, int reg, int value);

struct pqmdio_softc {
        struct mtx sc_lock;
        bus_space_handle_t sc_handle;
        int sc_offset;
};

static device_method_t pqmdio_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         pqmdio_fdt_probe),
        DEVMETHOD(device_attach,        pqmdio_fdt_attach),
        DEVMETHOD(device_detach,        pqmdio_detach),

        /* MII interface */
        DEVMETHOD(miibus_readreg,       pqmdio_miibus_readreg),
        DEVMETHOD(miibus_writereg,      pqmdio_miibus_writereg),

        DEVMETHOD_END
};

static struct ofw_compat_data mdio_compat_data[] = {
        {"fsl,fman-mdio", 0},
        {NULL, 0}
};

static driver_t pqmdio_driver = {
        "pq_mdio",
        pqmdio_methods,
        sizeof(struct pqmdio_softc),
};

static int
pqmdio_fdt_probe(device_t dev)
{

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

        if (!ofw_bus_search_compatible(dev, mdio_compat_data)->ocd_str)
                return (ENXIO);

        device_set_desc(dev, "Freescale QorIQ MDIO");

        return (BUS_PROBE_DEFAULT);
}

static int
pqmdio_fdt_attach(device_t dev)
{
        struct pqmdio_softc *sc;
        rman_res_t start, count;

        sc = device_get_softc(dev);

        fman_get_bushandle(device_get_parent(dev), &sc->sc_handle);
        bus_get_resource(dev, SYS_RES_MEMORY, 0, &start, &count);
        sc->sc_offset = start;

        OF_device_register_xref(OF_xref_from_node(ofw_bus_get_node(dev)), dev);

        mtx_init(&sc->sc_lock, device_get_nameunit(dev), "QorIQ MDIO lock",
            MTX_DEF);

        return (0);
}

static int
pqmdio_detach(device_t dev)
{
        struct pqmdio_softc *sc;

        sc = device_get_softc(dev);

        mtx_destroy(&sc->sc_lock);

        return (0);
}

int
pqmdio_miibus_readreg(device_t dev, int phy, int reg)
{
        struct pqmdio_softc *sc;
        int                  rv;

        sc = device_get_softc(dev);

        MDIO_LOCK();

        MDIO_WRITE4(sc, MDIO_MIIMADD, (phy << 8) | reg);
        MDIO_WRITE4(sc, MDIO_MIIMCOM, MIIMCOM_READ_CYCLE);

        MDIO_READ4(sc, MDIO_MIIMCOM);

        while ((MDIO_READ4(sc, MDIO_MIIMIND)) & MIIMIND_BUSY)
                ;

        rv = MDIO_READ4(sc, MDIO_MIIMSTAT);

        MDIO_WRITE4(sc, MDIO_MIIMCOM, 0);
        MDIO_READ4(sc, MDIO_MIIMCOM);
        MDIO_UNLOCK();

        return (rv);
}

int
pqmdio_miibus_writereg(device_t dev, int phy, int reg, int value)
{
        struct pqmdio_softc *sc;

        sc = device_get_softc(dev);

        MDIO_LOCK();
        /* Stop the MII management read cycle */
        MDIO_WRITE4(sc, MDIO_MIIMCOM, 0);
        MDIO_READ4(sc, MDIO_MIIMCOM);

        MDIO_WRITE4(sc, MDIO_MIIMADD, (phy << 8) | reg);

        MDIO_WRITE4(sc, MDIO_MIIMCON, value);
        MDIO_READ4(sc, MDIO_MIIMCON);

        /* Wait till MII management write is complete */
        while ((MDIO_READ4(sc, MDIO_MIIMIND)) & MIIMIND_BUSY)
                ;
        MDIO_UNLOCK();

        return (0);
}

EARLY_DRIVER_MODULE(pqmdio, fman, pqmdio_driver, 0, 0,
    BUS_PASS_SUPPORTDEV);
DRIVER_MODULE(miibus, pqmdio, miibus_driver, 0, 0);
MODULE_DEPEND(pqmdio, miibus, 1, 1, 1);