/*      $NetBSD: mii.c,v 1.12 1999/08/03 19:41:49 drochner Exp $        */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center.
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
/*
 * MII bus layer, glues MII-capable network interface drivers to sharable
 * PHY drivers.  This exports an interface compatible with BSD/OS 3.0's,
 * plus some NetBSD extensions.
 */

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

MODULE_VERSION(miibus, 1);

#include "miibus_if.h"

static bus_child_deleted_t miibus_child_deleted;
static bus_child_location_t miibus_child_location;
static bus_child_pnpinfo_t miibus_child_pnpinfo;
static device_detach_t miibus_detach;
static bus_hinted_child_t miibus_hinted_child;
static bus_print_child_t miibus_print_child;
static device_probe_t miibus_probe;
static bus_read_ivar_t miibus_read_ivar;
static miibus_readreg_t miibus_readreg;
static miibus_statchg_t miibus_statchg;
static miibus_writereg_t miibus_writereg;
static miibus_linkchg_t miibus_linkchg;
static miibus_mediainit_t miibus_mediainit;

static unsigned char mii_bitreverse(unsigned char x);

static device_method_t miibus_methods[] = {
        /* device interface */
        DEVMETHOD(device_probe,         miibus_probe),
        DEVMETHOD(device_attach,        miibus_attach),
        DEVMETHOD(device_detach,        miibus_detach),
        DEVMETHOD(device_shutdown,      bus_generic_shutdown),

        /* bus interface */
        DEVMETHOD(bus_print_child,      miibus_print_child),
        DEVMETHOD(bus_read_ivar,        miibus_read_ivar),
        DEVMETHOD(bus_child_deleted,    miibus_child_deleted),
        DEVMETHOD(bus_child_pnpinfo,    miibus_child_pnpinfo),
        DEVMETHOD(bus_child_location,   miibus_child_location),
        DEVMETHOD(bus_hinted_child,     miibus_hinted_child),

        /* MII interface */
        DEVMETHOD(miibus_readreg,       miibus_readreg),
        DEVMETHOD(miibus_writereg,      miibus_writereg),
        DEVMETHOD(miibus_statchg,       miibus_statchg),
        DEVMETHOD(miibus_linkchg,       miibus_linkchg),
        DEVMETHOD(miibus_mediainit,     miibus_mediainit),

        DEVMETHOD_END
};

DEFINE_CLASS_0(miibus, miibus_driver, miibus_methods, sizeof(struct mii_data));

struct miibus_ivars {
        if_t            ifp;
        ifm_change_cb_t ifmedia_upd;
        ifm_stat_cb_t   ifmedia_sts;
        u_int           mii_flags;
        u_int           mii_offset;
};

static int
miibus_probe(device_t dev)
{

        device_set_desc(dev, "MII bus");

        return (BUS_PROBE_SPECIFIC);
}

int
miibus_attach(device_t dev)
{
        struct miibus_ivars     *ivars;
        struct mii_attach_args  *ma;
        struct mii_data         *mii;
        device_t                *children;
        int                     i, nchildren;

        mii = device_get_softc(dev);
        if (device_get_children(dev, &children, &nchildren) == 0) {
                for (i = 0; i < nchildren; i++) {
                        ma = device_get_ivars(children[i]);
                        ma->mii_data = mii;
                }
                free(children, M_TEMP);
        }
        if (nchildren == 0) {
                device_printf(dev, "cannot get children\n");
                return (ENXIO);
        }
        ivars = device_get_ivars(dev);
        ifmedia_init(&mii->mii_media, IFM_IMASK, ivars->ifmedia_upd,
            ivars->ifmedia_sts);
        mii->mii_ifp = ivars->ifp;
        if_setcapabilitiesbit(mii->mii_ifp, IFCAP_LINKSTATE, 0);
        if_setcapenablebit(mii->mii_ifp, IFCAP_LINKSTATE, 0);
        LIST_INIT(&mii->mii_phys);

        bus_attach_children(dev);
        return (0);
}

static int
miibus_detach(device_t dev)
{
        struct mii_data         *mii;
        struct miibus_ivars     *ivars;

        ivars = device_get_ivars(dev);
        bus_generic_detach(dev);
        mii = device_get_softc(dev);
        ifmedia_removeall(&mii->mii_media);
        free(ivars, M_DEVBUF);
        mii->mii_ifp = NULL;

        return (0);
}

static void
miibus_child_deleted(device_t dev, device_t child)
{
        struct mii_attach_args *args;

        args = device_get_ivars(child);
        free(args, M_DEVBUF);
}

static int
miibus_print_child(device_t dev, device_t child)
{
        struct mii_attach_args *ma;
        int retval;

        ma = device_get_ivars(child);
        retval = bus_print_child_header(dev, child);
        retval += printf(" PHY %d", ma->mii_phyno);
        retval += bus_print_child_footer(dev, child);

        return (retval);
}

static int
miibus_read_ivar(device_t dev, device_t child __unused, int which,
    uintptr_t *result)
{
        struct miibus_ivars *ivars;

        /*
         * NB: this uses the instance variables of the miibus rather than
         * its PHY children.
         */
        ivars = device_get_ivars(dev);
        switch (which) {
        case MIIBUS_IVAR_FLAGS:
                *result = ivars->mii_flags;
                break;
        default:
                return (ENOENT);
        }
        return (0);
}

static int
miibus_child_pnpinfo(device_t dev __unused, device_t child, struct sbuf *sb)
{
        struct mii_attach_args *ma;

        ma = device_get_ivars(child);
        sbuf_printf(sb, "oui=0x%x model=0x%x rev=0x%x",
            MII_OUI(ma->mii_id1, ma->mii_id2),
            MII_MODEL(ma->mii_id2), MII_REV(ma->mii_id2));
        return (0);
}

static int
miibus_child_location(device_t dev __unused, device_t child, struct sbuf *sb)
{
        struct mii_attach_args *ma;

        ma = device_get_ivars(child);
        sbuf_printf(sb, "phyno=%d", ma->mii_phyno);
        return (0);
}

static void
miibus_hinted_child(device_t dev, const char *name, int unit)
{
        struct miibus_ivars *ivars;
        struct mii_attach_args *args, *ma;
        device_t *children, phy;
        int i, nchildren;
        u_int val;

        if (resource_int_value(name, unit, "phyno", &val) != 0)
                return;
        if (device_get_children(dev, &children, &nchildren) != 0)
                return;
        ma = NULL;
        for (i = 0; i < nchildren; i++) {
                args = device_get_ivars(children[i]);
                if (args->mii_phyno == val) {
                        ma = args;
                        break;
                }
        }
        free(children, M_TEMP);

        /*
         * Don't add a PHY that was automatically identified by having media
         * in its BMSR twice, only allow to alter its attach arguments.
         */
        if (ma == NULL) {
                ma = malloc(sizeof(struct mii_attach_args), M_DEVBUF,
                    M_NOWAIT);
                if (ma == NULL)
                        return;
                phy = device_add_child(dev, name, unit);
                if (phy == NULL) {
                        free(ma, M_DEVBUF);
                        return;
                }
                ivars = device_get_ivars(dev);
                ma->mii_phyno = val;
                ma->mii_offset = ivars->mii_offset++;
                ma->mii_id1 = 0;
                ma->mii_id2 = 0;
                ma->mii_capmask = BMSR_DEFCAPMASK;
                device_set_ivars(phy, ma);
        }

        if (resource_int_value(name, unit, "id1", &val) == 0)
                ma->mii_id1 = val;
        if (resource_int_value(name, unit, "id2", &val) == 0)
                ma->mii_id2 = val;
        if (resource_int_value(name, unit, "capmask", &val) == 0)
                ma->mii_capmask = val;
}

static int
miibus_readreg(device_t dev, int phy, int reg)
{
        device_t                parent;

        parent = device_get_parent(dev);
        return (MIIBUS_READREG(parent, phy, reg));
}

static int
miibus_writereg(device_t dev, int phy, int reg, int data)
{
        device_t                parent;

        parent = device_get_parent(dev);
        return (MIIBUS_WRITEREG(parent, phy, reg, data));
}

static void
miibus_statchg(device_t dev)
{
        device_t                parent;
        struct mii_data         *mii;

        parent = device_get_parent(dev);
        MIIBUS_STATCHG(parent);

        mii = device_get_softc(dev);
        if_setbaudrate(mii->mii_ifp, ifmedia_baudrate(mii->mii_media_active));
}

static void
miibus_linkchg(device_t dev)
{
        struct mii_data         *mii;
        device_t                parent;
        int                     link_state;

        parent = device_get_parent(dev);
        MIIBUS_LINKCHG(parent);

        mii = device_get_softc(dev);

        if (mii->mii_media_status & IFM_AVALID) {
                if (mii->mii_media_status & IFM_ACTIVE)
                        link_state = LINK_STATE_UP;
                else
                        link_state = LINK_STATE_DOWN;
        } else
                link_state = LINK_STATE_UNKNOWN;
        if_link_state_change(mii->mii_ifp, link_state);
}

static void
miibus_mediainit(device_t dev)
{
        struct mii_data         *mii;
        struct ifmedia_entry    *m;
        int                     media = 0;

        /* Poke the parent in case it has any media of its own to add. */
        MIIBUS_MEDIAINIT(device_get_parent(dev));

        mii = device_get_softc(dev);
        LIST_FOREACH(m, &mii->mii_media.ifm_list, ifm_list) {
                media = m->ifm_media;
                if (media == (IFM_ETHER | IFM_AUTO))
                        break;
        }

        ifmedia_set(&mii->mii_media, media);
}

/*
 * Helper function used by network interface drivers, attaches the miibus and
 * the PHYs to the network interface driver parent.
 */
int
mii_attach(device_t dev, device_t *miibus, if_t ifp,
    ifm_change_cb_t ifmedia_upd, ifm_stat_cb_t ifmedia_sts, int capmask,
    int phyloc, int offloc, int flags)
{
        struct miibus_ivars *ivars;
        struct mii_attach_args *args, ma;
        device_t *children, phy;
        int bmsr, first, i, nchildren, phymax, phymin, rv;
        uint32_t phymask;

        bus_topo_assert();

        if (phyloc != MII_PHY_ANY && offloc != MII_OFFSET_ANY) {
                printf("%s: phyloc and offloc specified\n", __func__);
                return (EINVAL);
        }

        if (offloc != MII_OFFSET_ANY && (offloc < 0 || offloc >= MII_NPHY)) {
                printf("%s: invalid offloc %d\n", __func__, offloc);
                return (EINVAL);
        }

        if (phyloc == MII_PHY_ANY) {
                phymin = 0;
                phymax = MII_NPHY - 1;
        } else {
                if (phyloc < 0 || phyloc >= MII_NPHY) {
                        printf("%s: invalid phyloc %d\n", __func__, phyloc);
                        return (EINVAL);
                }
                phymin = phymax = phyloc;
        }

        first = 0;
        if (*miibus == NULL) {
                first = 1;
                ivars = malloc(sizeof(*ivars), M_DEVBUF, M_NOWAIT);
                if (ivars == NULL)
                        return (ENOMEM);
                ivars->ifp = ifp;
                ivars->ifmedia_upd = ifmedia_upd;
                ivars->ifmedia_sts = ifmedia_sts;
                ivars->mii_flags = flags;
                *miibus = device_add_child(dev, "miibus", DEVICE_UNIT_ANY);
                if (*miibus == NULL) {
                        rv = ENXIO;
                        goto fail;
                }
                device_set_ivars(*miibus, ivars);
        } else {
                ivars = device_get_ivars(*miibus);
                if (ivars->ifp != ifp || ivars->ifmedia_upd != ifmedia_upd ||
                    ivars->ifmedia_sts != ifmedia_sts ||
                    ivars->mii_flags != flags) {
                        printf("%s: non-matching invariant\n", __func__);
                        return (EINVAL);
                }
                /*
                 * Assignment of the attach arguments mii_data for the first
                 * pass is done in miibus_attach(), i.e. once the miibus softc
                 * has been allocated.
                 */
                ma.mii_data = device_get_softc(*miibus);
        }

        ma.mii_capmask = capmask;

        if (resource_int_value(device_get_name(*miibus),
            device_get_unit(*miibus), "phymask", &phymask) != 0)
                phymask = 0xffffffff;

        if (device_get_children(*miibus, &children, &nchildren) != 0) {
                children = NULL;
                nchildren = 0;
        }
        ivars->mii_offset = 0;
        for (ma.mii_phyno = phymin; ma.mii_phyno <= phymax; ma.mii_phyno++) {
                /*
                 * Make sure we haven't already configured a PHY at this
                 * address.  This allows mii_attach() to be called
                 * multiple times.
                 */
                for (i = 0; i < nchildren; i++) {
                        args = device_get_ivars(children[i]);
                        if (args->mii_phyno == ma.mii_phyno) {
                                /*
                                 * Yes, there is already something
                                 * configured at this address.
                                 */
                                goto skip;
                        }
                }

                /*
                 * Check to see if there is a PHY at this address.  Note,
                 * many braindead PHYs report 0/0 in their ID registers,
                 * so we test for media in the BMSR.
                 */
                bmsr = MIIBUS_READREG(dev, ma.mii_phyno, MII_BMSR);
                if (bmsr == 0 || bmsr == 0xffff ||
                    (bmsr & (BMSR_EXTSTAT | BMSR_MEDIAMASK)) == 0) {
                        /* Assume no PHY at this address. */
                        continue;
                }

                /*
                 * There is a PHY at this address.  If we were given an
                 * `offset' locator, skip this PHY if it doesn't match.
                 */
                if (offloc != MII_OFFSET_ANY && offloc != ivars->mii_offset)
                        goto skip;

                /*
                 * Skip this PHY if it's not included in the phymask hint.
                 */
                if ((phymask & (1 << ma.mii_phyno)) == 0)
                        goto skip;

                /*
                 * Extract the IDs.  Braindead PHYs will be handled by
                 * the `ukphy' driver, as we have no ID information to
                 * match on.
                 */
                ma.mii_id1 = MIIBUS_READREG(dev, ma.mii_phyno, MII_PHYIDR1);
                ma.mii_id2 = MIIBUS_READREG(dev, ma.mii_phyno, MII_PHYIDR2);

                ma.mii_offset = ivars->mii_offset;
                args = malloc(sizeof(struct mii_attach_args), M_DEVBUF,
                    M_NOWAIT);
                if (args == NULL)
                        goto skip;
                bcopy((char *)&ma, (char *)args, sizeof(ma));
                phy = device_add_child(*miibus, NULL, DEVICE_UNIT_ANY);
                if (phy == NULL) {
                        free(args, M_DEVBUF);
                        goto skip;
                }
                device_set_ivars(phy, args);
 skip:
                ivars->mii_offset++;
        }
        free(children, M_TEMP);

        if (first != 0) {
                rv = device_set_driver(*miibus, &miibus_driver);
                if (rv != 0)
                        goto fail;
                bus_enumerate_hinted_children(*miibus);
                rv = device_get_children(*miibus, &children, &nchildren);
                if (rv != 0)
                        goto fail;
                free(children, M_TEMP);
                if (nchildren == 0) {
                        rv = ENXIO;
                        goto fail;
                }
                bus_attach_children(dev);

                /* Attaching of the PHY drivers is done in miibus_attach(). */
                return (0);
        }
        bus_attach_children(*miibus);

        return (0);

 fail:
        if (*miibus != NULL)
                device_delete_child(dev, *miibus);
        free(ivars, M_DEVBUF);
        if (first != 0)
                *miibus = NULL;
        return (rv);
}

/*
 * Media changed; notify all PHYs.
 */
int
mii_mediachg(struct mii_data *mii)
{
        struct mii_softc *child;
        struct ifmedia_entry *ife = mii->mii_media.ifm_cur;
        int rv;

        mii->mii_media_status = 0;
        mii->mii_media_active = IFM_NONE;

        LIST_FOREACH(child, &mii->mii_phys, mii_list) {
                /*
                 * If the media indicates a different PHY instance,
                 * isolate this one.
                 */
                if (IFM_INST(ife->ifm_media) != child->mii_inst) {
                        if ((child->mii_flags & MIIF_NOISOLATE) != 0) {
                                device_printf(child->mii_dev, "%s: "
                                    "can't handle non-zero PHY instance %d\n",
                                    __func__, child->mii_inst);
                                continue;
                        }
                        PHY_WRITE(child, MII_BMCR, PHY_READ(child, MII_BMCR) |
                            BMCR_ISO);
                        continue;
                }
                rv = PHY_SERVICE(child, mii, MII_MEDIACHG);
                if (rv)
                        return (rv);
        }
        return (0);
}

/*
 * Call the PHY tick routines, used during autonegotiation.
 */
void
mii_tick(struct mii_data *mii)
{
        struct mii_softc *child;
        struct ifmedia_entry *ife = mii->mii_media.ifm_cur;

        LIST_FOREACH(child, &mii->mii_phys, mii_list) {
                /*
                 * If this PHY instance isn't currently selected, just skip
                 * it.
                 */
                if (IFM_INST(ife->ifm_media) != child->mii_inst)
                        continue;
                (void)PHY_SERVICE(child, mii, MII_TICK);
        }
}

/*
 * Get media status from PHYs.
 */
void
mii_pollstat(struct mii_data *mii)
{
        struct mii_softc *child;
        struct ifmedia_entry *ife = mii->mii_media.ifm_cur;

        mii->mii_media_status = 0;
        mii->mii_media_active = IFM_NONE;

        LIST_FOREACH(child, &mii->mii_phys, mii_list) {
                /*
                 * If we're not polling this PHY instance, just skip it.
                 */
                if (IFM_INST(ife->ifm_media) != child->mii_inst)
                        continue;
                (void)PHY_SERVICE(child, mii, MII_POLLSTAT);
        }
}

static unsigned char
mii_bitreverse(unsigned char x)
{
        static unsigned const char nibbletab[16] = {
                0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15
        };

        return ((nibbletab[x & 15] << 4) | nibbletab[x >> 4]);
}

u_int
mii_oui(u_int id1, u_int id2)
{
        u_int h;

        h = (id1 << 6) | (id2 >> 10);

        return ((mii_bitreverse(h >> 16) << 16) |
            (mii_bitreverse((h >> 8) & 0xff) << 8) |
            mii_bitreverse(h & 0xff));
}

int
mii_phy_mac_match(struct mii_softc *mii, const char *name)
{

        return (strcmp(device_get_name(device_get_parent(mii->mii_dev)),
            name) == 0);
}

int
mii_dev_mac_match(device_t parent, const char *name)
{

        return (strcmp(device_get_name(device_get_parent(
            device_get_parent(parent))), name) == 0);
}

void *
mii_phy_mac_softc(struct mii_softc *mii)
{

        return (device_get_softc(device_get_parent(mii->mii_dev)));
}

void *
mii_dev_mac_softc(device_t parent)
{

        return (device_get_softc(device_get_parent(device_get_parent(parent))));
}