/*-
 * Copyright (c) 2014,2019 Ruslan Bukin <br@bsdpad.com>
 * All rights reserved.
 *
 * This software was developed by SRI International and the University of
 * Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237)
 * ("CTSRD"), as part of the DARPA CRASH research programme.
 *
 * 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 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>
/*
 * Micrel KSZ8081/KSZ9021/KSZ9031 Gigabit Ethernet Transceiver
 */

#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"

#include <dev/fdt/fdt_common.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/mii/mii_fdt.h>

#define	MII_KSZPHY_EXTREG			0x0b
#define	 KSZPHY_EXTREG_WRITE			(1 << 15)
#define	MII_KSZPHY_EXTREG_WRITE			0x0c
#define	MII_KSZPHY_EXTREG_READ			0x0d
#define	MII_KSZPHY_CLK_CONTROL_PAD_SKEW		0x104
#define	MII_KSZPHY_RX_DATA_PAD_SKEW		0x105
#define	MII_KSZPHY_TX_DATA_PAD_SKEW		0x106
/* KSZ9031 */
#define	MII_KSZ9031_MMD_ACCESS_CTRL		0x0d
#define	MII_KSZ9031_MMD_ACCESS_DATA		0x0e
#define	 MII_KSZ9031_MMD_DATA_NOINC		(1 << 14)
#define	MII_KSZ9031_CONTROL_PAD_SKEW		0x4
#define	MII_KSZ9031_RX_DATA_PAD_SKEW		0x5
#define	MII_KSZ9031_TX_DATA_PAD_SKEW		0x6
#define	MII_KSZ9031_CLOCK_PAD_SKEW		0x8

#define	MII_KSZ8081_PHYCTL2			0x1f

#define	PS_TO_REG(p)	((p) / 200)

static int micphy_probe(device_t);
static int micphy_attach(device_t);
static void micphy_reset(struct mii_softc *);
static int micphy_service(struct mii_softc *, struct mii_data *, int);

static device_method_t micphy_methods[] = {
	/* device interface */
	DEVMETHOD(device_probe,		micphy_probe),
	DEVMETHOD(device_attach,	micphy_attach),
	DEVMETHOD(device_detach,	mii_phy_detach),
	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
	DEVMETHOD_END
};

static devclass_t micphy_devclass;

static driver_t micphy_driver = {
	"micphy",
	micphy_methods,
	sizeof(struct mii_softc)
};

DRIVER_MODULE(micphy, miibus, micphy_driver, micphy_devclass, 0, 0);

static const struct mii_phydesc micphys[] = {
	MII_PHY_DESC(MICREL, KSZ8081),
	MII_PHY_DESC(MICREL, KSZ9021),
	MII_PHY_DESC(MICREL, KSZ9031),
	MII_PHY_END
};

static const struct mii_phy_funcs micphy_funcs = {
	micphy_service,
	ukphy_status,
	micphy_reset
};

static uint32_t
ksz9031_read(struct mii_softc *sc, uint32_t devaddr, uint32_t reg)
{
	/* Set up device address and register. */
        PHY_WRITE(sc, MII_KSZ9031_MMD_ACCESS_CTRL, devaddr);
        PHY_WRITE(sc, MII_KSZ9031_MMD_ACCESS_DATA, reg);

	/* Select register data for MMD and read the value. */
        PHY_WRITE(sc, MII_KSZ9031_MMD_ACCESS_CTRL,
	    MII_KSZ9031_MMD_DATA_NOINC | devaddr);

	return (PHY_READ(sc, MII_KSZ9031_MMD_ACCESS_DATA));
}

static void
ksz9031_write(struct mii_softc *sc, uint32_t devaddr, uint32_t reg,
	uint32_t val)
{

	/* Set up device address and register. */
	PHY_WRITE(sc, MII_KSZ9031_MMD_ACCESS_CTRL, devaddr);
	PHY_WRITE(sc, MII_KSZ9031_MMD_ACCESS_DATA, reg);

	/* Select register data for MMD and write the value. */
	PHY_WRITE(sc, MII_KSZ9031_MMD_ACCESS_CTRL,
	    MII_KSZ9031_MMD_DATA_NOINC | devaddr);
	PHY_WRITE(sc, MII_KSZ9031_MMD_ACCESS_DATA, val);
}

static uint32_t
ksz9021_read(struct mii_softc *sc, uint32_t reg)
{

	PHY_WRITE(sc, MII_KSZPHY_EXTREG, reg);

	return (PHY_READ(sc, MII_KSZPHY_EXTREG_READ));
}

static void
ksz9021_write(struct mii_softc *sc, uint32_t reg, uint32_t val)
{

	PHY_WRITE(sc, MII_KSZPHY_EXTREG, KSZPHY_EXTREG_WRITE | reg);
	PHY_WRITE(sc, MII_KSZPHY_EXTREG_WRITE, val);
}

static void
ksz90x1_load_values(struct mii_softc *sc, phandle_t node,
    uint32_t dev, uint32_t reg, char *field1, uint32_t f1mask, int f1off,
    char *field2, uint32_t f2mask, int f2off, char *field3, uint32_t f3mask,
    int f3off, char *field4, uint32_t f4mask, int f4off)
{
	pcell_t dts_value[1];
	int len;
	int val;

	if (sc->mii_mpd_model == MII_MODEL_MICREL_KSZ9031)
		val = ksz9031_read(sc, dev, reg);
	else
		val = ksz9021_read(sc, reg);

	if ((len = OF_getproplen(node, field1)) > 0) {
		OF_getencprop(node, field1, dts_value, len);
		val &= ~(f1mask << f1off);
		val |= (PS_TO_REG(dts_value[0]) & f1mask) << f1off;
	}

	if (field2 != NULL && (len = OF_getproplen(node, field2)) > 0) {
		OF_getencprop(node, field2, dts_value, len);
		val &= ~(f2mask << f2off);
		val |= (PS_TO_REG(dts_value[0]) & f2mask) << f2off;
	}

	if (field3 != NULL && (len = OF_getproplen(node, field3)) > 0) {
		OF_getencprop(node, field3, dts_value, len);
		val &= ~(f3mask << f3off);
		val |= (PS_TO_REG(dts_value[0]) & f3mask) << f3off;
	}

	if (field4 != NULL && (len = OF_getproplen(node, field4)) > 0) {
		OF_getencprop(node, field4, dts_value, len);
		val &= ~(f4mask << f4off);
		val |= (PS_TO_REG(dts_value[0]) & f4mask) << f4off;
	}

	if (sc->mii_mpd_model == MII_MODEL_MICREL_KSZ9031)
		ksz9031_write(sc, dev, reg, val);
	else
		ksz9021_write(sc, reg, val);
}

static void
ksz9031_load_values(struct mii_softc *sc, phandle_t node)
{

	ksz90x1_load_values(sc, node, 2, MII_KSZ9031_CONTROL_PAD_SKEW,
	    "txen-skew-ps", 0xf, 0, "rxdv-skew-ps", 0xf, 4,
	    NULL, 0, 0, NULL, 0, 0);
	ksz90x1_load_values(sc, node, 2, MII_KSZ9031_RX_DATA_PAD_SKEW,
	    "rxd0-skew-ps", 0xf, 0, "rxd1-skew-ps", 0xf, 4,
	    "rxd2-skew-ps", 0xf, 8, "rxd3-skew-ps", 0xf, 12);
	ksz90x1_load_values(sc, node, 2, MII_KSZ9031_TX_DATA_PAD_SKEW,
	    "txd0-skew-ps", 0xf, 0, "txd1-skew-ps", 0xf, 4,
	    "txd2-skew-ps", 0xf, 8, "txd3-skew-ps", 0xf, 12);
	ksz90x1_load_values(sc, node, 2, MII_KSZ9031_CLOCK_PAD_SKEW,
	    "rxc-skew-ps", 0x1f, 0, "txc-skew-ps", 0x1f, 5,
	    NULL, 0, 0, NULL, 0, 0);
}

static void
ksz9021_load_values(struct mii_softc *sc, phandle_t node)
{

	ksz90x1_load_values(sc, node, 0, MII_KSZPHY_CLK_CONTROL_PAD_SKEW,
	    "txen-skew-ps", 0xf, 0, "txc-skew-ps", 0xf, 4,
	    "rxdv-skew-ps", 0xf, 8, "rxc-skew-ps", 0xf, 12);
	ksz90x1_load_values(sc, node, 0, MII_KSZPHY_RX_DATA_PAD_SKEW,
	    "rxd0-skew-ps", 0xf, 0, "rxd1-skew-ps", 0xf, 4,
	    "rxd2-skew-ps", 0xf, 8, "rxd3-skew-ps", 0xf, 12);
	ksz90x1_load_values(sc, node, 0, MII_KSZPHY_TX_DATA_PAD_SKEW,
	    "txd0-skew-ps", 0xf, 0, "txd1-skew-ps", 0xf, 4,
	    "txd2-skew-ps", 0xf, 8, "txd3-skew-ps", 0xf, 12);
}

static int
micphy_probe(device_t dev)
{

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

static int
micphy_attach(device_t dev)
{
	mii_fdt_phy_config_t *cfg;
	struct mii_softc *sc;
	phandle_t node;
	device_t miibus;
	device_t parent;

	sc = device_get_softc(dev);

	mii_phy_dev_attach(dev, MIIF_NOMANPAUSE, &micphy_funcs, 1);
	mii_phy_setmedia(sc);

	/* Nothing further to configure for 8081 model. */
	if (sc->mii_mpd_model == MII_MODEL_MICREL_KSZ8081)
		return (0);

	miibus = device_get_parent(dev);
	parent = device_get_parent(miibus);

	if ((node = ofw_bus_get_node(parent)) == -1)
		return (ENXIO);

	cfg = mii_fdt_get_config(dev);

	if (sc->mii_mpd_model == MII_MODEL_MICREL_KSZ9031)
		ksz9031_load_values(sc, cfg->phynode);
	else
		ksz9021_load_values(sc, cfg->phynode);

	mii_fdt_free_config(cfg);

	return (0);
}

static void
micphy_reset(struct mii_softc *sc)
{
	int reg;

	/*
	 * The 8081 has no "sticky bits" that survive a soft reset; several bits
	 * in the Phy Control Register 2 must be preserved across the reset.
	 * These bits are set up by the bootloader; they control how the phy
	 * interfaces to the board (such as clock frequency and LED behavior).
	 */
	if (sc->mii_mpd_model == MII_MODEL_MICREL_KSZ8081)
		reg = PHY_READ(sc, MII_KSZ8081_PHYCTL2);
	mii_phy_reset(sc);
	if (sc->mii_mpd_model == MII_MODEL_MICREL_KSZ8081)
		PHY_WRITE(sc, MII_KSZ8081_PHYCTL2, reg);
}

static int
micphy_service(struct mii_softc *sc, struct mii_data *mii, int cmd)
{

	switch (cmd) {
	case MII_POLLSTAT:
		break;

	case MII_MEDIACHG:
		mii_phy_setmedia(sc);
		break;

	case MII_TICK:
		if (mii_phy_tick(sc) == EJUSTRETURN)
			return (0);
		break;
	}

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

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