/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2001-2003, Shunsuke Akiyama <akiyama@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, 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.
 *
 */

/*
 * driver for Realtek RTL8150 internal PHY
 */

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

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

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

#include <dev/usb/net/ruephyreg.h>

#include "miibus_if.h"

static int ruephy_probe(device_t);
static int ruephy_attach(device_t);

static device_method_t ruephy_methods[] = {
        /* device interface */
        DEVMETHOD(device_probe,         ruephy_probe),
        DEVMETHOD(device_attach,        ruephy_attach),
        DEVMETHOD(device_detach,        mii_phy_detach),
        DEVMETHOD(device_shutdown,      bus_generic_shutdown),
        DEVMETHOD_END
};

static driver_t ruephy_driver = {
        .name = "ruephy",
        .methods = ruephy_methods,
        .size = sizeof(struct mii_softc)
};

DRIVER_MODULE(ruephy, miibus, ruephy_driver, 0, 0);

static int ruephy_service(struct mii_softc *, struct mii_data *, int);
static void ruephy_reset(struct mii_softc *);
static void ruephy_status(struct mii_softc *);

/*
 * The Realtek RTL8150 internal PHY doesn't have vendor/device ID
 * registers; rue(4) fakes up a return value of all zeros.
 */
static const struct mii_phydesc ruephys[] = {
        { 0, 0, "Realtek RTL8150 internal media interface" },
        MII_PHY_END
};

static const struct mii_phy_funcs ruephy_funcs = {
        ruephy_service,
        ruephy_status,
        ruephy_reset
};

static int
ruephy_probe(device_t dev)
{

        if (strcmp(device_get_name(device_get_parent(device_get_parent(dev))),
            "rue") == 0)
                return (mii_phy_dev_probe(dev, ruephys, BUS_PROBE_DEFAULT));
        return (ENXIO);
}

static int
ruephy_attach(device_t dev)
{

        mii_phy_dev_attach(dev, MIIF_NOISOLATE | MIIF_NOMANPAUSE,
            &ruephy_funcs, 1);
        return (0);
}

static int
ruephy_service(struct mii_softc *sc, struct mii_data *mii, int cmd)
{
        struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
        int reg;

        switch (cmd) {
        case MII_POLLSTAT:
                break;

        case MII_MEDIACHG:
                mii_phy_setmedia(sc);
                break;

        case MII_TICK:
                /*
                 * Only used for autonegotiation.
                 */
                if (IFM_SUBTYPE(ife->ifm_media) != IFM_AUTO)
                        break;

                /*
                 * Check to see if we have link.  If we do, we don't
                 * need to restart the autonegotiation process.  Read
                 * the MSR twice in case it's latched.
                 */
                reg = PHY_READ(sc, RUEPHY_MII_MSR) |
                    PHY_READ(sc, RUEPHY_MII_MSR);
                if (reg & RUEPHY_MSR_LINK)
                        break;

                /* Only retry autonegotiation every mii_anegticks seconds. */
                if (sc->mii_ticks <= sc->mii_anegticks)
                        break;

                sc->mii_ticks = 0;
                PHY_RESET(sc);
                if (mii_phy_auto(sc) == EJUSTRETURN)
                        return (0);
                break;
        }

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

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

        return (0);
}

static void
ruephy_reset(struct mii_softc *sc)
{

        mii_phy_reset(sc);

        /*
         * XXX Realtek RTL8150 PHY doesn't set the BMCR properly after
         * XXX reset, which breaks autonegotiation.
         */
        PHY_WRITE(sc, MII_BMCR, (BMCR_S100 | BMCR_AUTOEN | BMCR_FDX));
}

static void
ruephy_status(struct mii_softc *phy)
{
        struct mii_data *mii = phy->mii_pdata;
        struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
        int bmsr, bmcr, msr;

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

        msr = PHY_READ(phy, RUEPHY_MII_MSR) | PHY_READ(phy, RUEPHY_MII_MSR);
        if (msr & RUEPHY_MSR_LINK)
                mii->mii_media_status |= IFM_ACTIVE;

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

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

                if (msr & RUEPHY_MSR_SPEED100)
                        mii->mii_media_active |= IFM_100_TX;
                else
                        mii->mii_media_active |= IFM_10_T;

                if (msr & RUEPHY_MSR_DUPLEX)
                        mii->mii_media_active |=
                            IFM_FDX | mii_phy_flowstatus(phy);
                else
                        mii->mii_media_active |= IFM_HDX;
        } else
                mii->mii_media_active = ife->ifm_media;
}