/*
 * Copyright (c) 1997, 1998, 1999
 *      Bill Paul <wpaul@ctr.columbia.edu>.  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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul 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 Bill Paul OR THE VOICES IN HIS HEAD
 * 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/mlphy.c,v 1.2.2.3 2001/02/09 09:50:15 asmodai Exp $
 */

/*
 * driver for Micro Linear 6692 PHYs
 *
 * The Micro Linear 6692 is a strange beast, and dealing with it using
 * this code framework is tricky. The 6692 is actually a 100Mbps-only
 * device, which means that a second PHY is required to support 10Mbps
 * modes. However, even though the 6692 does not support 10Mbps modes,
 * it can still advertise them when performing autonegotiation. If a
 * 10Mbps mode is negotiated, we must program the registers of the
 * companion PHY accordingly in addition to programming the registers
 * of the 6692.
 *
 * This device also does not have vendor/device ID registers.
 */

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

#include <machine/clock.h>

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

#include "mii.h"
#include "miivar.h"

#include "miibus_if.h"

#define ML_STATE_AUTO_SELF      1
#define ML_STATE_AUTO_OTHER     2

struct mlphy_softc      {
        struct mii_softc        ml_mii;
        int                     ml_state;
        int                     ml_linked;
};

static int mlphy_probe          (device_t);
static int mlphy_attach         (device_t);
static int mlphy_detach         (device_t);

static device_method_t mlphy_methods[] = {
        /* device interface */
        DEVMETHOD(device_probe,         mlphy_probe),
        DEVMETHOD(device_attach,        mlphy_attach),
        DEVMETHOD(device_detach,        mlphy_detach),
        DEVMETHOD(device_shutdown,      bus_generic_shutdown),
        DEVMETHOD_END
};

static devclass_t mlphy_devclass;

static driver_t mlphy_driver = {
        "mlphy",
        mlphy_methods,
        sizeof(struct mlphy_softc)
};

DRIVER_MODULE(mlphy, miibus, mlphy_driver, mlphy_devclass, NULL, NULL);

static int      mlphy_service (struct mii_softc *, struct mii_data *, int);
static void     mlphy_reset (struct mii_softc *);
static void     mlphy_status (struct mii_softc *);

static int
mlphy_probe(device_t dev)
{
        struct mii_attach_args  *ma;
        device_t                parent;

        ma = device_get_ivars(dev);
        parent = device_get_parent(device_get_parent(dev));

        /*
         * Micro Linear PHY reports oui == 0 model == 0
         */
        if (MII_OUI(ma->mii_id1, ma->mii_id2) != 0 ||
            MII_MODEL(ma->mii_id2) != 0)
                return (ENXIO);

        /*
         * Make sure the parent is a `tl'. So far, I have only
         * encountered the 6692 on an Olicom card with a ThunderLAN
         * controller chip.
         */
        if (strcmp(device_get_name(parent), "tl") != 0)
                return (ENXIO);

        device_set_desc(dev, "Micro Linear 6692 media interface");

        return (0);
}

static int
mlphy_attach(device_t dev)
{
        struct mlphy_softc *msc;
        struct mii_softc *sc;
        struct mii_attach_args *ma;
        struct mii_data *mii;

        msc = device_get_softc(dev);
        sc = &msc->ml_mii;
        ma = device_get_ivars(dev);
        mii_softc_init(sc, ma);
        sc->mii_dev = device_get_parent(dev);
        mii = device_get_softc(sc->mii_dev);
        LIST_INSERT_HEAD(&mii->mii_phys, sc, mii_list);

        sc->mii_inst = mii->mii_instance;
        sc->mii_service = mlphy_service;
        sc->mii_reset = mlphy_reset;
        sc->mii_pdata = mii;

        mii->mii_instance++;

#define ADD(m, c)       ifmedia_add(&mii->mii_media, (m), (c), NULL)

#if 0 /* See above. */
        ADD(IFM_MAKEWORD(IFM_ETHER, IFM_NONE, 0, sc->mii_inst),
            MII_MEDIA_NONE);
#endif
        ADD(IFM_MAKEWORD(IFM_ETHER, IFM_100_TX, IFM_LOOP, sc->mii_inst),
            MII_MEDIA_100_TX);

        sc->mii_flags &= ~MIIF_NOISOLATE;
        mii_phy_reset(sc);
        sc->mii_flags |= MIIF_NOISOLATE;

        sc->mii_capabilities = PHY_READ(sc, MII_BMSR) & ma->mii_capmask;

        device_printf(dev, " ");
        if ((sc->mii_capabilities & BMSR_MEDIAMASK) == 0)
                kprintf("no media present");
        else
                mii_phy_add_media(sc);
        kprintf("\n");
#undef ADD
        MIIBUS_MEDIAINIT(sc->mii_dev);
        return(0);
}

static int
mlphy_detach(device_t dev)
{
        struct mlphy_softc *sc;

        sc = device_get_softc(dev);
        sc->ml_mii.mii_dev = NULL;
        LIST_REMOVE(&sc->ml_mii, mii_list);

        return(0);
}

static int
mlphy_service(struct mii_softc *xsc, struct mii_data *mii, int cmd)
{
        struct ifmedia_entry    *ife = mii->mii_media.ifm_cur;
        int                     reg;
        struct mii_softc        *other = NULL;
        struct mlphy_softc      *msc = (struct mlphy_softc *)xsc;
        struct mii_softc        *sc = &msc->ml_mii;
        device_t                *devlist;
        int                     devs, i;
        const struct mii_media  *mm;

        /*
         * See if there's another PHY on this bus with us.
         * If so, we may need it for 10Mbps modes.
         */
        device_get_children(msc->ml_mii.mii_dev, &devlist, &devs);
        for (i = 0; i < devs; i++) {
                if (strcmp(device_get_name(devlist[i]), "mlphy")) {
                        other = device_get_softc(devlist[i]);
                        break;
                }
        }
        kfree(devlist, M_TEMP);

        KKASSERT(ife->ifm_data >= 0 && ife->ifm_data < MII_NMEDIA);
        mm = &mii_media_table[ife->ifm_data];

        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) {
                        reg = PHY_READ(sc, MII_BMCR);
                        PHY_WRITE(sc, MII_BMCR, reg | BMCR_ISO);
                        return (0);
                }

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

                switch (IFM_SUBTYPE(ife->ifm_media)) {
                case IFM_AUTO:
                        /*
                         * For autonegotiation, reset and isolate the
                         * companion PHY (if any) and then do NWAY
                         * autonegotiation ourselves.
                         */
                        msc->ml_state = ML_STATE_AUTO_SELF;
                        if (other != NULL) {
                                mii_phy_reset(other);
                                PHY_WRITE(other, MII_BMCR, BMCR_ISO);
                        }
                        mii_phy_auto(sc, 1);
                        msc->ml_linked = 0;
                        return(0);

                case IFM_10_T:
                        /*
                         * For 10baseT modes, reset and program the
                         * companion PHY (of any), then program ourselves
                         * to match. This will put us in pass-through
                         * mode and let the companion PHY do all the
                         * work.
                         */
                        if (other != NULL) {
                                mii_phy_reset(other);
                                PHY_WRITE(other, MII_BMCR, mm->mm_bmcr);
                        }
                        PHY_WRITE(sc, MII_ANAR, mm->mm_anar);
                        PHY_WRITE(sc, MII_BMCR, mm->mm_bmcr);
                        msc->ml_state = 0;
                        break;

                case IFM_100_TX:
                        /*
                         * For 100baseTX modes, reset and isolate the
                         * companion PHY (if any), then program ourselves
                         * accordingly.
                         */
                        if (other != NULL) {
                                mii_phy_reset(other);
                                PHY_WRITE(other, MII_BMCR, BMCR_ISO);
                        }
                        PHY_WRITE(sc, MII_ANAR, mm->mm_anar);
                        PHY_WRITE(sc, MII_BMCR, mm->mm_bmcr);
                        msc->ml_state = 0;
                        break;

                case IFM_100_T4:
                        /*
                         * XXX Not supported as a manual setting right now.
                         */
                        return (EINVAL);
                default:
                        break;
                }
                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)
                        break;

                /*
                 * Check to see if we have link.  If we do, we don't
                 * need to restart the autonegotiation process.  Read
                 * the BMSR twice in case it's latched.
                 * If we're in a 10Mbps mode, check the link of the
                 * 10Mbps PHY. Sometimes the Micro Linear PHY's
                 * linkstat bit will clear while the linkstat bit of
                 * the companion PHY will remain set.
                 */
                if (msc->ml_state == ML_STATE_AUTO_OTHER) {
                        reg = PHY_READ(other, MII_BMSR) |
                            PHY_READ(other, MII_BMSR);
                } else {
                        reg = PHY_READ(sc, MII_BMSR) |
                            PHY_READ(sc, MII_BMSR);
                }
                if (reg & BMSR_LINK) {
                        if (!msc->ml_linked) {
                                msc->ml_linked = 1;
                                mlphy_status(sc);
                        }
                        sc->mii_ticks = 0;
                        break;
                }

                /*
                 * Only retry autonegotiation every 5 seconds.
                 */
                if (++sc->mii_ticks <= sc->mii_anegticks)
                        return (0);
                
                sc->mii_ticks = 0;
                msc->ml_linked = 0;
                mii->mii_media_active = IFM_NONE;
                mii_phy_reset(sc);
                msc->ml_state = ML_STATE_AUTO_SELF;
                if (other != NULL) {
                        mii_phy_reset(other);
                        PHY_WRITE(other, MII_BMCR, BMCR_ISO);
                }
                if (mii_phy_auto(sc, 0) == EJUSTRETURN)
                        return(0);
                break;
        }

        /* Update the media status. */
        if (msc->ml_state == ML_STATE_AUTO_OTHER) {
                int other_inst;

                other_inst = other->mii_inst;
                other->mii_inst = sc->mii_inst;
                other->mii_service(other, mii, MII_POLLSTAT);
                other->mii_inst = other_inst;
                sc->mii_media_active = other->mii_media_active;
                sc->mii_media_status = other->mii_media_status;
        } else {
                ukphy_status(sc);
        }

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

/*
 * The Micro Linear PHY comes out of reset with the 'autoneg
 * enable' bit set, which we don't want.
 */
static void
mlphy_reset(struct mii_softc *sc)
{
        int                     reg;

        mii_phy_reset(sc);
        reg = PHY_READ(sc, MII_BMCR);
        reg &= ~BMCR_AUTOEN;
        PHY_WRITE(sc, MII_BMCR, reg);
}

/*
 * If we negotiate a 10Mbps mode, we need to check for an alternate
 * PHY and make sure it's enabled and set correctly.
 */
static void
mlphy_status(struct mii_softc *sc)
{
        struct mlphy_softc      *msc = (struct mlphy_softc *)sc;
        struct mii_data         *mii = msc->ml_mii.mii_pdata;
        struct mii_softc        *other = NULL;
        device_t                *devlist;
        int                     devs, i;

        /* See if there's another PHY on the bus with us. */
        device_get_children(msc->ml_mii.mii_dev, &devlist, &devs);
        for (i = 0; i < devs; i++) {
                if (strcmp(device_get_name(devlist[i]), "mlphy")) {
                        other = device_get_softc(devlist[i]);
                        break;
                }
        }
        kfree(devlist, M_TEMP);

        if (other == NULL)
                return;

        ukphy_status(sc);

        if (IFM_SUBTYPE(mii->mii_media_active) != IFM_10_T) {
                msc->ml_state = ML_STATE_AUTO_SELF;
                mii_phy_reset(other);
                PHY_WRITE(other, MII_BMCR, BMCR_ISO);
        }

        if (IFM_SUBTYPE(mii->mii_media_active) == IFM_10_T) {
                msc->ml_state = ML_STATE_AUTO_OTHER;
                mlphy_reset(&msc->ml_mii);
                PHY_WRITE(&msc->ml_mii, MII_BMCR, BMCR_ISO);
                mii_phy_reset(other);
                mii_phy_auto(other, 1);
        }
}