/*      $NetBSD: rdcphy.c,v 1.8 2020/04/08 03:01:58 msaitoh Exp $        */

/*-
 * 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.
 */

/* FreeBSD: src/sys/dev/mii/rdcphy.c,v 1.1 2010/12/30 23:50:25 yongari Exp */

/*
 * Driver for the RDC Semiconductor R6040 10/100 PHY.
 */
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rdcphy.c,v 1.8 2020/04/08 03:01:58 msaitoh Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/device.h>
#include <sys/socket.h>
#include <sys/errno.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 <dev/mii/miidevs.h>

#include <dev/mii/rdcphyreg.h>

struct rdcphy_softc {
        struct mii_softc sc_mii;
        int              sc_mii_link_tick;
#define RDCPHY_MANNEG_TICK      3
};

static int      rdcphymatch(device_t, cfdata_t, void *);
static void     rdcphyattach(device_t, device_t, void *);

CFATTACH_DECL_NEW(rdcphy, sizeof(struct rdcphy_softc),
    rdcphymatch, rdcphyattach, mii_phy_detach, mii_phy_activate);


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

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

static const struct mii_phydesc rdcphys[] = {
        MII_PHY_DESC(xxRDC, R6040),
        MII_PHY_DESC(xxRDC, R6040_2),
        MII_PHY_DESC(xxRDC, R6040_3),
        MII_PHY_END,
};

static int
rdcphymatch(device_t parent, cfdata_t match, void *aux)
{
        struct mii_attach_args *ma = aux;

        if (mii_phy_match(ma, rdcphys) != NULL)
                return 10;

        return 0;
}

static void
rdcphyattach(device_t parent, device_t self, void *aux)
{
        struct rdcphy_softc *rsc = device_private(self);
        struct mii_softc *sc = &rsc->sc_mii;
        struct mii_attach_args *ma = aux;
        struct mii_data *mii = ma->mii_data;

        const struct mii_phydesc *mpd;

        mpd = mii_phy_match(ma, rdcphys);
        aprint_naive(": Media interface\n");
        aprint_normal(": %s, rev. %d\n", mpd->mpd_name, MII_REV(ma->mii_id2));

        sc->mii_dev = self;
        sc->mii_inst = mii->mii_instance;
        sc->mii_phy = ma->mii_phyno;
        sc->mii_funcs = &rdcphy_funcs;
        sc->mii_pdata = mii;
        sc->mii_flags = ma->mii_flags;

        mii_lock(mii);

        PHY_RESET(sc);

        PHY_READ(sc, MII_BMSR, &sc->mii_capabilities);
        sc->mii_capabilities &= ma->mii_capmask;
        if (sc->mii_capabilities & BMSR_EXTSTAT)
                PHY_READ(sc, MII_EXTSR, &sc->mii_extcapabilities);

        mii_unlock(mii);

        mii_phy_add_media(sc);
}

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

        KASSERT(mii_locked(mii));

        switch (cmd) {
        case MII_POLLSTAT:
                break;

        case MII_MEDIACHG:
                /* If the interface is not up, don't do anything. */
                if ((mii->mii_ifp->if_flags & IFF_UP) == 0)
                        break;

                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->sc_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->sc_mii_link_tick > 0) {
                                rsc->sc_mii_link_tick--;
                                return 0;
                        }
                }
                break;
        }

        /* Update the media status. */
        rdcphy_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 = sc->mii_pdata;
        uint16_t bmsr, bmcr, physts;

        KASSERT(mii_locked(mii));

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

        PHY_READ(sc, MII_BMSR, &bmsr);
        PHY_READ(sc, MII_BMSR, &bmsr);
        PHY_READ(sc, MII_RDCPHY_STATUS, &physts);

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

        PHY_READ(sc, MII_BMCR, &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;
}