/*      $NetBSD: urlphy.c,v 1.40 2023/02/22 08:09:09 msaitoh Exp $      */
/*
 * Copyright (c) 2001, 2002
 *     Shingo WATANABE <nabe@nabechan.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.
 * 3. 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 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 RL8150L internal phy
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: urlphy.c,v 1.40 2023/02/22 08:09:09 msaitoh Exp $");

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

#ifdef URLPHY_DEBUG
#define DPRINTF(x)      if (urlphydebug) printf x
#define DPRINTFN(n,x)   if (urlphydebug>(n)) printf x
int urlphydebug = URLPHY_DEBUG;
#else
#define DPRINTF(x)
#define DPRINTFN(n,x)
#endif

static int      urlphy_match(device_t, cfdata_t, void *);
static void     urlphy_attach(device_t, device_t, void *);

CFATTACH_DECL_NEW(urlphy, sizeof(struct mii_softc),
    urlphy_match, urlphy_attach, mii_phy_detach, mii_phy_activate);

static int      urlphy_service(struct mii_softc *, struct mii_data *, int);
static void     urlphy_status(struct mii_softc *);

static const struct mii_phy_funcs urlphy_funcs = {
        urlphy_service, urlphy_status, mii_phy_reset,
};

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

        /* RTL8150 reports OUI == 0, MODEL == 0 */
        if (MII_OUI(ma->mii_id1, ma->mii_id2) != 0 &&
            MII_MODEL(ma->mii_id2) != 0)
                return 0;

        /* Make sure the parent is an 'url' device. */
        if (!device_is_a(parent, "url"))
                return 0;

        return 10;
}

static void
urlphy_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;

        aprint_naive(": Media interface\n");
        aprint_normal(": Realtek RTL8150L internal media interface\n");

        DPRINTF(("%s: %s: enter\n", device_xname(self), __func__));

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

        /* Don't do loopback on this PHY. */
        sc->mii_flags |= MIIF_NOLOOP;
        /* Don't do isolate on this PHY. */
        sc->mii_flags |= MIIF_NOISOLATE;

        if (mii->mii_instance != 0) {
                aprint_error_dev(self,
                    "ignoring this PHY, non-zero instance\n");
                return;
        }

        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 int
urlphy_service(struct mii_softc *sc, struct mii_data *mii, int cmd)
{
        struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
        uint16_t reg;

        DPRINTF(("%s: %s: enter\n", device_xname(sc->mii_dev), __func__));

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

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

                mii_phy_setmedia(sc);
                break;

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

                /* Just bail now if the interface is down. */
                if ((mii->mii_ifp->if_flags & IFF_UP) == 0)
                        return 0;

                /*
                 * If we're not doing autonegotiation, we don't need to do
                 * any extra work here.  However, we need to check the link
                 * status so we can generate an announcement if the status
                 * changes.
                 */
                if (IFM_SUBTYPE(ife->ifm_media) != IFM_AUTO)
                        break;

                /* Read the status register twice; MSR_LINK is latch-low. */
                PHY_READ(sc, URLPHY_MSR, &reg);
                PHY_READ(sc, URLPHY_MSR, &reg);
                if (reg & URLPHY_MSR_LINK) {
                        /*
                         * Reset autonegotiation timer to 0 in case the link
                         * goes down in the next tick.
                         */
                        sc->mii_ticks = 0;
                        /* See above. */
                        break;
                }

                /*
                 * mii_ticks == 0 means it's the first tick after changing the
                 * media or the link became down since the last tick (see
                 * above), so break to update the status.
                 */
                if (sc->mii_ticks++ == 0)
                        break;

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

                if (mii_phy_auto_restart(sc) == EJUSTRETURN)
                        return 0;

                break;

        case MII_DOWN:
                mii_phy_down(sc);
                return 0;
        }

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

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

        return 0;
}

static void
urlphy_status(struct mii_softc *sc)
{
        struct mii_data *mii = sc->mii_pdata;
        struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
        uint16_t msr, bmsr, bmcr;

        DPRINTF(("%s: %s: enter\n", device_xname(sc->mii_dev), __func__));

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

        /*
         * The link status bit is not exist in the BMSR register,
         * so we need to read the MSR register to get link status.
         */
        PHY_READ(sc, URLPHY_MSR, &msr);
        PHY_READ(sc, URLPHY_MSR, &msr);
        if (msr & URLPHY_MSR_LINK)
                mii->mii_media_status |= IFM_ACTIVE;

        DPRINTF(("%s: %s: link %s\n", device_xname(sc->mii_dev), __func__,
                 mii->mii_media_status & IFM_ACTIVE ? "up" : "down"));

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

                if (msr & URLPHY_MSR_SPEED_100)
                        mii->mii_media_active |= IFM_100_TX;
                else
                        mii->mii_media_active |= IFM_10_T;

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