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

#include <sys/cdefs.h>
/*
 * Driver for the RDC Semiconductor R6040 10/100 PHY.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/socket.h>
#include <sys/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 <dev/mii/rdcphyreg.h>

#include "miibus_if.h"

static device_probe_t	rdcphy_probe;
static device_attach_t	rdcphy_attach;

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

static device_method_t rdcphy_methods[] = {
	/* device interface */
	DEVMETHOD(device_probe,		rdcphy_probe),
	DEVMETHOD(device_attach,	rdcphy_attach),
	DEVMETHOD(device_detach,	mii_phy_detach),
	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
	DEVMETHOD_END
};

static devclass_t rdcphy_devclass;

static driver_t rdcphy_driver = {
	"rdcphy",
	rdcphy_methods,
	sizeof(struct rdcphy_softc)
};

DRIVER_MODULE(rdcphy, miibus, rdcphy_driver, rdcphy_devclass, 0, 0);

static int	rdcphy_service(struct mii_softc *, struct mii_data *, int);
static void	rdcphy_status(struct mii_softc *);

static const struct mii_phydesc rdcphys[] = {
	MII_PHY_DESC(RDC, R6040),
	MII_PHY_END
};

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

static int
rdcphy_probe(device_t dev)
{

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

static int
rdcphy_attach(device_t dev)
{

	mii_phy_dev_attach(dev, MIIF_NOMANPAUSE, &rdcphy_funcs, 1);
	return (0);
}

static int
rdcphy_service(struct mii_softc *sc, struct mii_data *mii, int cmd)
{
	struct rdcphy_softc *rsc;
	struct ifmedia_entry *ife;

	rsc = (struct rdcphy_softc *)sc;
	ife = mii->mii_media.ifm_cur;

	switch (cmd) {
	case MII_POLLSTAT:
		break;

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

	case MII_TICK:
		if (mii_phy_tick(sc) == 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 (rsc->mii_link_tick > 0) {
				rsc->mii_link_tick--;
				return (0);
			}
		}
		break;
	}

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

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

static void
rdcphy_status(struct mii_softc *sc)
{
	struct mii_data *mii;
	int bmsr, bmcr, physts;

	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);
	physts = PHY_READ(sc, MII_RDCPHY_STATUS);

	if ((physts & STATUS_LINK_UP) != 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;
		}
	}

	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;
}