/* $NetBSD: smscphy.c,v 1.4 2021/08/25 21:50:29 andvar Exp $ */

/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2006 Benno Rice.  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.
 */

/* $FreeBSD: head/sys/dev/mii/smscphy.c 326255 2017-11-27 14:52:40Z pfg $ */

/*
 * Driver for the SMSC LAN8710A
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: smscphy.c,v 1.4 2021/08/25 21:50:29 andvar 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 <net/if.h>
#include <net/if_media.h>

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

/* PHY special control/status register */
#define SMSCPHY_SPCSR   0x1f
#define  SPCSR_SPDIND_10        0x0004
#define  SPCSR_SPDIND_100       0x0008
#define  SPCSR_SPDIND_SPDMASK   0x000c
#define  SPCSR_SPDIND_FDX       0x0010

static int      smscphy_match(device_t, cfdata_t, void *);
static void     smscphy_attach(device_t, device_t, void *);

CFATTACH_DECL_NEW(smscphy, sizeof (struct mii_softc),
    smscphy_match, smscphy_attach, mii_phy_detach, mii_phy_activate);

static void     smscphy_power(struct mii_softc *, bool);
static int      smscphy_service(struct mii_softc *, struct mii_data *, int);
static void     smscphy_auto(struct mii_softc *, int);
static void     smscphy_status(struct mii_softc *);

static const struct mii_phydesc smscphys[] = {
        MII_PHY_DESC(SMSC, LAN8700),
        MII_PHY_DESC(SMSC, LAN8710_LAN8720),
        MII_PHY_END
};

static const struct mii_phy_funcs smscphy_funcs = {
        smscphy_service,
        smscphy_status,
        mii_phy_reset
};

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

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

        return 0;
}

static void
smscphy_attach(device_t parent, device_t self, void *aux)
{
        struct mii_softc *sc = device_private(self);
        struct mii_attach_args *ma = aux;
        struct mii_data *mii = ma->mii_data;
        const struct mii_phydesc *mpd;

        mpd = mii_phy_match(ma, smscphys);
        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 = &smscphy_funcs;
        sc->mii_mpd_oui = MII_OUI(ma->mii_id1, ma->mii_id2);
        sc->mii_mpd_model = MII_MODEL(ma->mii_id2);
        sc->mii_mpd_rev = MII_REV(ma->mii_id2);
        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;

        mii_unlock(mii);

        mii_phy_add_media(sc);
}

static void
smscphy_power(struct mii_softc *sc, bool power)
{
        uint16_t bmcr, new;

        PHY_READ(sc, MII_BMCR, &bmcr);
        if (power)
                new = bmcr & ~BMCR_PDOWN;
        else
                new = bmcr | BMCR_PDOWN;
        if (bmcr != new)
                PHY_WRITE(sc, MII_BMCR, new);
}

static int
smscphy_service(struct mii_softc *sc, struct mii_data *mii, int cmd)
{
        struct  ifmedia_entry *ife;
        uint16_t reg;

        KASSERT(mii_locked(mii));

        ife = mii->mii_media.ifm_cur;

        switch (cmd) {
        case MII_POLLSTAT:
                break;

        case MII_MEDIACHG:
                /* Try to power up the PHY in case it's down */
                if (IFM_SUBTYPE(ife->ifm_media) != IFM_NONE)
                        smscphy_power(sc, true);

                switch (IFM_SUBTYPE(ife->ifm_media)) {
                case IFM_AUTO:
                        smscphy_auto(sc, ife->ifm_media);
                        break;

                default:
                        mii_phy_setmedia(sc);
                        if (IFM_SUBTYPE(ife->ifm_media) == IFM_NONE)
                                smscphy_power(sc, false);
                        break;
                }
                break;

        case MII_TICK:
                if (IFM_SUBTYPE(ife->ifm_media) != IFM_AUTO)
                        break;

                PHY_READ(sc, MII_BMSR, &reg);
                PHY_READ(sc, MII_BMSR, &reg);
                if (reg & BMSR_LINK) {
                        sc->mii_ticks = 0;
                        break;
                }

                if (++sc->mii_ticks <= MII_ANEGTICKS)
                        break;

                PHY_RESET(sc);
                smscphy_auto(sc, ife->ifm_media);
                break;
        }

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

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

static void
smscphy_auto(struct mii_softc *sc, int media)
{
        uint16_t anar;

        sc->mii_ticks = 0;
        anar = BMSR_MEDIA_TO_ANAR(sc->mii_capabilities) | ANAR_CSMA;
        if ((media & IFM_FLOW) != 0)
                anar |= ANAR_FC;
        PHY_WRITE(sc, MII_ANAR, anar);
        /* Apparently this helps. */
        PHY_READ(sc, MII_ANAR, &anar);
        PHY_WRITE(sc, MII_BMCR, BMCR_AUTOEN | BMCR_STARTNEG);
}

static void
smscphy_status(struct mii_softc *sc)
{
        struct mii_data *mii = sc->mii_pdata;
        uint16_t bmcr, bmsr, status;

        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);
        if ((bmsr & BMSR_LINK) != 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;
                }
        }

        PHY_READ(sc, SMSCPHY_SPCSR, &status);
        if ((status & SPCSR_SPDIND_SPDMASK) == SPCSR_SPDIND_100)
                mii->mii_media_active |= IFM_100_TX;
        else
                mii->mii_media_active |= IFM_10_T;
        if (status & SPCSR_SPDIND_FDX)
                mii->mii_media_active |= IFM_FDX | mii_phy_flowstatus(sc);
        else
                mii->mii_media_active |= IFM_HDX;
}