/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010, Pyun YongHyeon <yongari@FreeBSD.org>
 * 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 unmodified, 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>
/*
 * Driver for the RDC Semiconductor R6040 10/100 PHY.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/socket.h>
#include <sys/bus.h>

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

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

#include <dev/mii/rdcphyreg.h>

#include "miibus_if.h"

static device_probe_t   rdcphy_probe;
static device_attach_t  rdcphy_attach;

struct rdcphy_softc {
        struct mii_softc mii_sc;
        int mii_link_tick;
#define RDCPHY_MANNEG_TICK      3
};

static device_method_t rdcphy_methods[] = {
        /* device interface */
        DEVMETHOD(device_probe,         rdcphy_probe),
        DEVMETHOD(device_attach,        rdcphy_attach),
        DEVMETHOD(device_detach,        mii_phy_detach),
        DEVMETHOD(device_shutdown,      bus_generic_shutdown),
        DEVMETHOD_END
};

static driver_t rdcphy_driver = {
        "rdcphy",
        rdcphy_methods,
        sizeof(struct rdcphy_softc)
};

DRIVER_MODULE(rdcphy, miibus, rdcphy_driver, 0, 0);

static int      rdcphy_service(struct mii_softc *, struct mii_data *, int);
static void     rdcphy_status(struct mii_softc *);

static const struct mii_phydesc rdcphys[] = {
        MII_PHY_DESC(RDC, R6040),
        MII_PHY_DESC(RDC, R6040_2),
        MII_PHY_END
};

static const struct mii_phy_funcs rdcphy_funcs = {
        rdcphy_service,
        rdcphy_status,
        mii_phy_reset
};

static int
rdcphy_probe(device_t dev)
{

        return (mii_phy_dev_probe(dev, rdcphys, BUS_PROBE_DEFAULT));
}

static int
rdcphy_attach(device_t dev)
{

        mii_phy_dev_attach(dev, MIIF_NOMANPAUSE, &rdcphy_funcs, 1);
        return (0);
}

static int
rdcphy_service(struct mii_softc *sc, struct mii_data *mii, int cmd)
{
        struct rdcphy_softc *rsc;
        struct ifmedia_entry *ife;

        rsc = (struct rdcphy_softc *)sc;
        ife = mii->mii_media.ifm_cur;

        switch (cmd) {
        case MII_POLLSTAT:
                break;

        case MII_MEDIACHG:
                mii_phy_setmedia(sc);
                switch (IFM_SUBTYPE(ife->ifm_media)) {
                case IFM_100_TX:
                case IFM_10_T:
                        /*
                         * Report fake lost link event to parent
                         * driver.  This will stop MAC of parent
                         * driver and make it possible to reconfigure
                         * MAC after completion of link establishment.
                         * Note, the parent MAC seems to require
                         * restarting MAC when underlying any PHY
                         * configuration was changed even if the
                         * resolved speed/duplex was not changed at
                         * all.
                         */
                        mii->mii_media_status = 0;
                        mii->mii_media_active = IFM_ETHER | IFM_NONE;
                        rsc->mii_link_tick = RDCPHY_MANNEG_TICK;
                        /* Immediately report link down. */
                        mii_phy_update(sc, MII_MEDIACHG);
                        return (0);
                default:
                        break;
                }
                break;

        case MII_TICK:
                if (mii_phy_tick(sc) == EJUSTRETURN)
                        return (0);
                if (IFM_SUBTYPE(ife->ifm_media) != IFM_AUTO) {
                        /*
                         * It seems the PHY hardware does not correctly
                         * report link status changes when manual link
                         * configuration is in progress.  It is also
                         * possible for the PHY to complete establishing
                         * a link within one second such that mii(4)
                         * did not notice the link change.  To workaround
                         * the issue, emulate lost link event and wait
                         * for 3 seconds when manual link configuration
                         * is in progress.  3 seconds would be long
                         * enough to absorb transient link flips.
                         */
                        if (rsc->mii_link_tick > 0) {
                                rsc->mii_link_tick--;
                                return (0);
                        }
                }
                break;
        }

        /* Update the media status. */
        PHY_STATUS(sc);

        /* Callback if something changed. */
        mii_phy_update(sc, cmd);
        return (0);
}

static void
rdcphy_status(struct mii_softc *sc)
{
        struct mii_data *mii;
        int bmsr, bmcr, physts;

        mii = sc->mii_pdata;

        mii->mii_media_status = IFM_AVALID;
        mii->mii_media_active = IFM_ETHER;

        bmsr = PHY_READ(sc, MII_BMSR) | PHY_READ(sc, MII_BMSR);
        physts = PHY_READ(sc, MII_RDCPHY_STATUS);

        if ((physts & STATUS_LINK_UP) != 0)
                mii->mii_media_status |= IFM_ACTIVE;

        bmcr = PHY_READ(sc, MII_BMCR);
        if ((bmcr & BMCR_ISO) != 0) {
                mii->mii_media_active |= IFM_NONE;
                mii->mii_media_status = 0;
                return;
        }

        if ((bmcr & BMCR_LOOP) != 0)
                mii->mii_media_active |= IFM_LOOP;

        if ((bmcr & BMCR_AUTOEN) != 0) {
                if ((bmsr & BMSR_ACOMP) == 0) {
                        /* Erg, still trying, I guess... */
                        mii->mii_media_active |= IFM_NONE;
                        return;
                }
        }

        switch (physts & STATUS_SPEED_MASK) {
        case STATUS_SPEED_100:
                mii->mii_media_active |= IFM_100_TX;
                break;
        case STATUS_SPEED_10:
                mii->mii_media_active |= IFM_10_T;
                break;
        default:
                mii->mii_media_active |= IFM_NONE;
                return;
        }
        if ((physts & STATUS_FULL_DUPLEX) != 0)
                mii->mii_media_active |= IFM_FDX | mii_phy_flowstatus(sc);
        else
                mii->mii_media_active |= IFM_HDX;
}