/*      $OpenBSD: rdcphy.c,v 1.5 2022/04/19 03:26:33 kevlo 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.
 */

/*
 * Driver for the RDC Semiconductor R6040 10/100 PHY.
 */

#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_var.h>
#include <net/if_media.h>

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

#define MII_RDCPHY_DEBUG        0x11
#define DEBUG_JABBER_DIS        0x0040
#define DEBUG_LOOP_BACK_10MBPS  0x0400

#define MII_RDCPHY_CTRL         0x14
#define CTRL_SQE_ENB            0x0100
#define CTRL_NEG_POLARITY       0x0400
#define CTRL_AUTO_POLARITY      0x0800
#define CTRL_MDIXSEL_RX         0x2000
#define CTRL_MDIXSEL_TX         0x4000
#define CTRL_AUTO_MDIX_DIS      0x8000

#define MII_RDCPHY_CTRL2        0x15
#define CTRL2_LED_DUPLEX        0x0000
#define CTRL2_LED_DUPLEX_COL    0x0008
#define CTRL2_LED_ACT           0x0010
#define CTRL2_LED_SPEED_ACT     0x0018
#define CTRL2_LED_BLK_100MBPS_DIS       0x0020
#define CTRL2_LED_BLK_10MBPS_DIS        0x0040
#define CTRL2_LED_BLK_LINK_ACT_DIS      0x0080
#define CTRL2_SDT_THRESH_MASK   0x3E00
#define CTRL2_TIMING_ERR_SEL    0x4000
#define CTRL2_LED_BLK_80MS      0x8000
#define CTRL2_LED_BLK_160MS     0x0000
#define CTRL2_LED_MASK          0x0018

#define MII_RDCPHY_STATUS       0x16
#define STATUS_AUTO_MDIX_RX     0x0200
#define STATUS_AUTO_MDIX_TX     0x0400
#define STATUS_NEG_POLARITY     0x0800
#define STATUS_FULL_DUPLEX      0x1000
#define STATUS_SPEED_10         0x0000
#define STATUS_SPEED_100        0x2000
#define STATUS_SPEED_MASK       0x6000
#define STATUS_LINK_UP          0x8000

/* Analog test register 2 */
#define MII_RDCPHY_TEST2        0x1A
#define TEST2_PWR_DOWN          0x0200

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

int     rdcphy_service(struct mii_softc *, struct mii_data *, int);
void    rdcphy_attach(struct device *, struct device *, void *);
int     rdcphy_match(struct device *, void *, void *);
void    rdcphy_status(struct mii_softc *);

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

static const struct mii_phydesc rdcphys[] = {
        { MII_OUI_RDC,          MII_MODEL_RDC_R6040,
          MII_STR_RDC_R6040 },
        { MII_OUI_RDC,          MII_MODEL_RDC_R6040_2,
          MII_STR_RDC_R6040_2 },
        { 0,                    0,
          NULL },
};

const struct cfattach rdcphy_ca = {
        sizeof(struct rdcphy_softc), rdcphy_match, rdcphy_attach,
        mii_phy_detach
};

struct cfdriver rdcphy_cd = {
        NULL, "rdcphy", DV_DULL
};

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

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

        return (0);
}

void
rdcphy_attach(struct device *parent, struct device *self, void *aux)
{
        struct rdcphy_softc *sc = (struct rdcphy_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, rdcphys);
        printf(": %s, rev. %d\n", mpd->mpd_name, MII_REV(ma->mii_id2));

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

        PHY_RESET(&sc->sc_mii);

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

        if (sc->sc_mii.mii_capabilities & BMSR_MEDIAMASK)
                mii_phy_add_media(&sc->sc_mii);
}

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

        if ((sc->sc_mii.mii_dev.dv_flags & DVF_ACTIVE) == 0)
                return (ENXIO);

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

                mii_phy_setmedia(&sc->sc_mii);
                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;
                        sc->mii_link_tick = RDCPHY_MANNEG_TICK;
                        /* Immediately report link down. */
                        mii_phy_update(&sc->sc_mii, MII_MEDIACHG);
                        return (0);
                default:
                        break;
                }
                break;

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

                if (mii_phy_tick(&sc->sc_mii) == 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 (sc->mii_link_tick > 0) {
                                sc->mii_link_tick--;
                                return (0);
                        }
                }
                break;
        }

        /* Update the media status. */
        mii_phy_status(&sc->sc_mii);

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

void
rdcphy_status(struct mii_softc *sc)
{
        struct mii_data *mii = sc->mii_pdata;
        struct ifmedia_entry *ife;
        int bmsr, bmcr, physts;

        ife = mii->mii_media.ifm_cur;

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

        bmsr = PHY_READ(sc, MII_BMSR) | PHY_READ(sc, MII_BMSR);
        physts = PHY_READ(sc, MII_RDCPHY_STATUS);

        if (physts & STATUS_LINK_UP)
                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;

        if (bmcr & BMCR_AUTOEN) {
                if (!(bmsr & BMSR_ACOMP)) {
                        /* 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;
}