/*-
 * 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 driver_t micphy_driver = {
        "micphy",
        micphy_methods,
        sizeof(struct mii_softc)
};

DRIVER_MODULE(micphy, miibus, micphy_driver, 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);
}