/*      $OpenBSD: atphy.c,v 1.13 2022/04/06 18:59:29 naddy Exp $        */

/*-
 * Copyright (c) 2008, 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.
 */

/*
 * Driver for the Attansic F1 10/100/1000 PHY.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/socket.h>

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

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

/* Special Control Register */
#define ATPHY_SCR                       0x10
#define ATPHY_SCR_JABBER_DISABLE        0x0001
#define ATPHY_SCR_POLARITY_REVERSAL     0x0002
#define ATPHY_SCR_SQE_TEST              0x0004
#define ATPHY_SCR_MAC_PDOWN             0x0008
#define ATPHY_SCR_CLK125_DISABLE        0x0010
#define ATPHY_SCR_MDI_MANUAL_MODE       0x0000
#define ATPHY_SCR_MDIX_MANUAL_MODE      0x0020
#define ATPHY_SCR_AUTO_X_1000T          0x0040
#define ATPHY_SCR_AUTO_X_MODE           0x0060
#define ATPHY_SCR_10BT_EXT_ENABLE       0x0080
#define ATPHY_SCR_MII_5BIT_ENABLE       0x0100
#define ATPHY_SCR_SCRAMBLER_DISABLE     0x0200
#define ATPHY_SCR_FORCE_LINK_GOOD       0x0400
#define ATPHY_SCR_ASSERT_CRS_ON_TX      0x0800

/* Special Status Register. */
#define ATPHY_SSR                       0x11
#define ATPHY_SSR_SPD_DPLX_RESOLVED     0x0800
#define ATPHY_SSR_DUPLEX                0x2000
#define ATPHY_SSR_SPEED_MASK            0xC000
#define ATPHY_SSR_10MBS                 0x0000
#define ATPHY_SSR_100MBS                0x4000
#define ATPHY_SSR_1000MBS               0x8000

int     atphy_service(struct mii_softc *, struct mii_data *, int);
void    atphy_attach(struct device *, struct device *, void *);
int     atphy_match(struct device *, void *, void *);
void    atphy_reset(struct mii_softc *);
void    atphy_status(struct mii_softc *);
int     atphy_mii_phy_auto(struct mii_softc *);

const struct mii_phy_funcs atphy_funcs = {
        atphy_service, atphy_status, atphy_reset,
};

static const struct mii_phydesc atphys[] = {
        { MII_OUI_ATHEROS,      MII_MODEL_ATHEROS_F1,
          MII_STR_ATHEROS_F1 },
        { MII_OUI_ATHEROS,      MII_MODEL_ATHEROS_F2,
          MII_STR_ATHEROS_F2 },
        { MII_OUI_ATHEROS,      MII_MODEL_ATHEROS_AR8035,
          MII_STR_ATHEROS_AR8035 },
        { 0,                    0,
          NULL },
};

const struct cfattach atphy_ca = {
        sizeof (struct mii_softc), atphy_match, atphy_attach,
        mii_phy_detach
};

struct cfdriver atphy_cd = {
        NULL, "atphy", DV_DULL
};

int
atphy_match(struct device *parent, void *match, void *aux)
{
        struct mii_attach_args *ma = aux;

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

        return (0);
}

void
atphy_attach(struct device *parent, struct device *self, void *aux)
{
        struct mii_softc *sc = (struct mii_softc *)self;
        struct mii_attach_args *ma = aux;
        struct mii_data *mii = ma->mii_data;
        const struct mii_phydesc *mpd;

        mpd = mii_phy_match(ma, atphys);
        printf(": %s, rev. %d\n", mpd->mpd_name, MII_REV(ma->mii_id2));

        sc->mii_inst = mii->mii_instance;
        sc->mii_phy = ma->mii_phyno;
        sc->mii_funcs = &atphy_funcs;
        sc->mii_oui = MII_OUI(ma->mii_id1, ma->mii_id2);
        sc->mii_model = MII_MODEL(ma->mii_id2);
        sc->mii_pdata = mii;
        sc->mii_flags = ma->mii_flags;
        sc->mii_anegticks = MII_ANEGTICKS_GIGE;

        sc->mii_flags |= MIIF_NOLOOP;

        PHY_RESET(sc);

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

        mii_phy_add_media(sc);
}

int
atphy_service(struct mii_softc *sc, struct mii_data *mii, int cmd)
{
        struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
        uint16_t anar, bmcr, bmsr;

        switch (cmd) {
        case MII_POLLSTAT:
                /*
                 * If we're not polling our PHY instance, just return.
                 */
                if (IFM_INST(ife->ifm_media) != sc->mii_inst)
                        return (0);
                break;

        case MII_MEDIACHG:
                /*
                 * If the media indicates a different PHY instance,
                 * isolate ourselves.
                 */
                if (IFM_INST(ife->ifm_media) != sc->mii_inst) {
                        bmcr = PHY_READ(sc, MII_BMCR);
                        PHY_WRITE(sc, MII_BMCR, bmcr | BMCR_ISO);
                        return (0);
                }

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

                bmcr = 0;
                switch (IFM_SUBTYPE(ife->ifm_media)) {
                case IFM_AUTO:
                case IFM_1000_T:
                        atphy_mii_phy_auto(sc);
                        goto done;
                case IFM_100_TX:
                        bmcr = BMCR_S100;
                        break;
                case IFM_10_T:
                        bmcr = BMCR_S10;
                        break;
                case IFM_NONE:
                        bmcr = PHY_READ(sc, MII_BMCR);
                        /*
                         * XXX
                         * Due to an unknown reason powering down PHY resulted
                         * in unexpected results such as inaccessibility of
                         * hardware of freshly rebooted system. Disable
                         * powering down PHY until I get more information for
                         * Attansic/Atheros PHY hardware.
                         */
                        PHY_WRITE(sc, MII_BMCR, bmcr | BMCR_ISO);
                        goto done;
                default:
                        return (EINVAL);
                }

                anar = mii_anar(ife->ifm_media);
                if (((ife->ifm_media & IFM_GMASK) & IFM_FDX) != 0) {
                        bmcr |= BMCR_FDX;
                        /* Enable pause. */
                        if (sc->mii_flags & MIIF_DOPAUSE)
                                anar |= ANAR_PAUSE_TOWARDS;
                }

                if ((sc->mii_extcapabilities & (EXTSR_1000TFDX |
                    EXTSR_1000THDX)) != 0)
                        PHY_WRITE(sc, MII_100T2CR, 0);
                PHY_WRITE(sc, MII_ANAR, anar);

                /*
                 * Reset the PHY so all changes take effect.
                 */
                PHY_WRITE(sc, MII_BMCR, bmcr | BMCR_RESET | BMCR_AUTOEN |
                    BMCR_STARTNEG);
done:
                break;

        case MII_TICK:
                /*
                 * If we're not currently selected, just return.
                 */
                if (IFM_INST(ife->ifm_media) != sc->mii_inst)
                        return (0);

                /*
                 * Is the interface even up?
                 */
                if ((mii->mii_ifp->if_flags & IFF_UP) == 0)
                        return (0);

                /*
                 * Only used for autonegotiation.
                 */
                if (IFM_SUBTYPE(ife->ifm_media) != IFM_AUTO) {
                        sc->mii_ticks = 0;
                        break;
                }

                /*
                 * Check for link.
                 * Read the status register twice; BMSR_LINK is latch-low.
                 */
                bmsr = PHY_READ(sc, MII_BMSR) | PHY_READ(sc, MII_BMSR);
                if (bmsr & BMSR_LINK) {
                        sc->mii_ticks = 0;
                        break;
                }

                /* Announce link loss right after it happens. */
                if (sc->mii_ticks++ == 0)
                        break;

                /*
                 * Only retry autonegotiation every mii_anegticks seconds.
                 */
                if (sc->mii_ticks <= sc->mii_anegticks)
                        return (0);

                sc->mii_ticks = 0;
                atphy_mii_phy_auto(sc);
                break;
        }

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

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

void
atphy_status(struct mii_softc *sc)
{
        struct mii_data *mii = sc->mii_pdata;
        uint32_t bmsr, bmcr, gsr, ssr;

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

        bmsr = PHY_READ(sc, MII_BMSR) | PHY_READ(sc, MII_BMSR);
        if (bmsr & BMSR_LINK)
                mii->mii_media_status |= IFM_ACTIVE;

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

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

        ssr = PHY_READ(sc, ATPHY_SSR);
        if (!(ssr & ATPHY_SSR_SPD_DPLX_RESOLVED)) {
                /* Erg, still trying, I guess... */
                mii->mii_media_active |= IFM_NONE;
                return;
        }

        switch (ssr & ATPHY_SSR_SPEED_MASK) {
        case ATPHY_SSR_1000MBS:
                mii->mii_media_active |= IFM_1000_T;
                /*
                 * atphy(4) has a valid link so reset mii_ticks.
                 * Resetting mii_ticks is needed in order to
                 * detect link loss after auto-negotiation.
                 */
                sc->mii_ticks = 0;
                break;
        case ATPHY_SSR_100MBS:
                mii->mii_media_active |= IFM_100_TX;
                sc->mii_ticks = 0;
                break;
        case ATPHY_SSR_10MBS:
                mii->mii_media_active |= IFM_10_T;
                sc->mii_ticks = 0;
                break;
        default:
                mii->mii_media_active |= IFM_NONE;
                return;
        }

        if (ssr & ATPHY_SSR_DUPLEX)
                mii->mii_media_active |= IFM_FDX | mii_phy_flowstatus(sc);
        else
                mii->mii_media_active |= IFM_HDX;

        gsr = PHY_READ(sc, MII_100T2SR);
        if ((IFM_SUBTYPE(mii->mii_media_active) == IFM_1000_T) &&
            gsr & GTSR_MS_RES)
                mii->mii_media_active |= IFM_ETH_MASTER;
}

void
atphy_reset(struct mii_softc *sc)
{
        uint32_t reg;
        int i;

        /* Take PHY out of power down mode. */
        PHY_WRITE(sc, 29, 0x29);
        PHY_WRITE(sc, 30, 0);

        reg = PHY_READ(sc, ATPHY_SCR);
        /* Enable automatic crossover. */
        reg |= ATPHY_SCR_AUTO_X_MODE;
        /* Disable power down. */
        reg &= ~ATPHY_SCR_MAC_PDOWN;
        /* Enable CRS on Tx. */
        reg |= ATPHY_SCR_ASSERT_CRS_ON_TX;
        /* Auto correction for reversed cable polarity. */
        reg |= ATPHY_SCR_POLARITY_REVERSAL;
        PHY_WRITE(sc, ATPHY_SCR, reg);

        /* Workaround F1 bug to reset phy. */
        atphy_mii_phy_auto(sc);

        for (i = 0; i < 1000; i++) {
                DELAY(1);
                if ((PHY_READ(sc, MII_BMCR) & BMCR_RESET) == 0)
                        break;
        }
}

int
atphy_mii_phy_auto(struct mii_softc *sc)
{
        uint16_t anar;

        anar = BMSR_MEDIA_TO_ANAR(sc->mii_capabilities) | ANAR_CSMA;
        if (sc->mii_flags & MIIF_DOPAUSE)
                anar |= ANAR_PAUSE_TOWARDS;
        PHY_WRITE(sc, MII_ANAR, anar);
        if (sc->mii_extcapabilities & (EXTSR_1000TFDX | EXTSR_1000THDX))
                PHY_WRITE(sc, MII_100T2CR, GTCR_ADV_1000TFDX |
                    GTCR_ADV_1000THDX);
        else if (sc->mii_model == MII_MODEL_ATHEROS_F1) {
                /*
                 * AR8132 has 10/100 PHY and the PHY uses the same
                 * model number of F1 gigabit PHY.  The PHY has no
                 * ability to establish gigabit link so explicitly
                 * disable 1000baseT configuration for the PHY.
                 * Otherwise, there is a case that atphy(4) could
                 * not establish a link against gigabit link partner
                 * unless the link partner supports down-shifting.
                 */
                PHY_WRITE(sc, MII_100T2CR, 0);
        }
        PHY_WRITE(sc, MII_BMCR, BMCR_RESET | BMCR_AUTOEN | BMCR_STARTNEG);

        return (EJUSTRETURN);
}