/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * 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.
 */

#include <sys/cdefs.h>
/*
 * Driver for the SMSC LAN8710A
 */

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

#include <machine/bus.h>

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

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

#include "miibus_if.h"

static int	smscphy_probe(device_t);
static int	smscphy_attach(device_t);

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 device_method_t smscphy_methods[] = {
	/* device interface */
	DEVMETHOD(device_probe,		smscphy_probe),
	DEVMETHOD(device_attach,	smscphy_attach),
	DEVMETHOD(device_detach,	mii_phy_detach),
	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
	DEVMETHOD_END
};

static devclass_t smscphy_devclass;

static driver_t smscphy_driver = {
	"smscphy",
	smscphy_methods,
	sizeof(struct mii_softc)
};

DRIVER_MODULE(smscphy, miibus, smscphy_driver, smscphy_devclass, 0, 0);

static const struct mii_phydesc smscphys[] = {
	MII_PHY_DESC(SMC, LAN8710A),
	MII_PHY_DESC(SMC, LAN8700),
	MII_PHY_END
};

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

static int
smscphy_probe(device_t dev)
{

	return (mii_phy_dev_probe(dev, smscphys, BUS_PROBE_DEFAULT));
}

static int
smscphy_attach(device_t dev)
{
	struct mii_softc *sc;
	const struct mii_phy_funcs *mpf;

	sc = device_get_softc(dev);
	mpf = &smscphy_funcs;
	mii_phy_dev_attach(dev, MIIF_NOISOLATE | MIIF_NOMANPAUSE, mpf, 1);
	mii_phy_setmedia(sc);

	return (0);
}

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

	ife = mii->mii_media.ifm_cur;

        switch (cmd) {
        case MII_POLLSTAT:
                break;

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

		default:
                	mii_phy_setmedia(sc);
			break;
		}

                break;

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

		/* I have no idea why BMCR_ISO gets set. */
		reg = PHY_READ(sc, MII_BMCR);
		if (reg & BMCR_ISO) {
			PHY_WRITE(sc, MII_BMCR, reg & ~BMCR_ISO);
		}

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

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

		sc->mii_ticks = 0;
		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;

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

static void
smscphy_status(struct mii_softc *sc)
{
	struct mii_data *mii;
	uint32_t bmcr, bmsr, status;

	mii = sc->mii_pdata;
	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) != 0)
		mii->mii_media_status |= IFM_ACTIVE;

	bmcr = PHY_READ(sc, MII_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;
		}
	}

	status = PHY_READ(sc, 0x1F);
	if (status & 0x0008)
		mii->mii_media_active |= IFM_100_TX;
	else
		mii->mii_media_active |= IFM_10_T;
	if (status & 0x0010)
		mii->mii_media_active |= IFM_FDX | mii_phy_flowstatus(sc);
	else
		mii->mii_media_active |= IFM_HDX;
}