source: freebsd-mos-driver/if_mos.c@ 405

/*-
 * Copyright (c) 2011 Rick van der Zwet <info@rickvanderzwet.nl>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*-
 * Copyright (c) 2008 Johann Christian Rode <jcrode@gmx.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*-
 * Copyright (c) 2005, 2006, 2007 Jonathan Gray <jsg@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*-
 * Copyright (c) 1997, 1998, 1999, 2000-2003
 *      Bill Paul <wpaul@windriver.com>.  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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul 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 Bill Paul OR THE VOICES IN HIS HEAD
 * 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>
__FBSDID("$FreeBSD$");

/*
 * Moschip MCS7730/MCS7830 USB to Ethernet controller
 * The datasheet is available at the following URL:
 * http://www.moschip.com/data/products/MCS7830/Data%20Sheet_7830.pdf
 */

/*
 * The FreeBSD if_mos.c driver is based on various different sources:
 * The vendor provided driver at the following URL:
 * http://www.moschip.com/data/products/MCS7830/Driver_FreeBSD_7830.tar.gz
 *
 * Mixed together with the OpenBSD if_mos.c driver for validation and checking
 * and the FreeBSD if_reu.c as reference for the USB Ethernet framework.
 */

#include <sys/stdint.h>
#include <sys/stddef.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/linker_set.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <sys/sx.h>
#include <sys/unistd.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/priv.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
#include "usbdevs.h"

#define USB_DEBUG_VAR mos_debug
#include <dev/usb/usb_debug.h>
#include <dev/usb/usb_process.h>

#include <dev/usb/net/usb_ethernet.h>

//#include <dev/usb/net/if_mosreg.h>
#include "if_mosreg.h"

#ifdef USB_DEBUG
static int mos_debug = 0;

SYSCTL_NODE(_hw_usb, OID_AUTO, mos, CTLFLAG_RW, 0, "USB mos");
SYSCTL_INT(_hw_usb_mos, OID_AUTO, debug, CTLFLAG_RW, &mos_debug, 0,
    "Debug level");
#endif

#define MOS_DPRINTFN(fmt,...) \
  DPRINTF("mos: %s: " fmt "\n",__FUNCTION__,## __VA_ARGS__)

#define USB_PRODUCT_MOSCHIP_MCS7730     0x7730
#define USB_PRODUCT_SITECOMEU_LN030     0x0021

/* Various supported device vendors/products. */
static const struct usb_device_id mos_devs[] = {
        {USB_VPI(USB_VENDOR_MOSCHIP, USB_PRODUCT_MOSCHIP_MCS7730, MCS7730)},
        {USB_VPI(USB_VENDOR_MOSCHIP, USB_PRODUCT_MOSCHIP_MCS7830, MCS7830)},
        {USB_VPI(USB_VENDOR_SITECOMEU, USB_PRODUCT_SITECOMEU_LN030, MCS7830)},
};

static int mos_probe(device_t dev);
static int mos_attach(device_t dev);
static void mos_attach_post(struct usb_ether *ue);
static int mos_detach(device_t dev);

static void mos_bulk_read_callback(struct usb_xfer *xfer, usb_error_t error);
static void mos_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error);
static void mos_intr_callback(struct usb_xfer *xfer, usb_error_t error);
static void mos_tick(struct usb_ether *);
static void mos_start(struct usb_ether *);
static void mos_init(struct usb_ether *);
static void mos_chip_init(struct mos_softc *);
static void mos_stop(struct usb_ether *);
static int mos_miibus_readreg(device_t, int, int);
static int mos_miibus_writereg(device_t, int, int, int);
static void mos_miibus_statchg(device_t);
static int mos_ifmedia_upd(struct ifnet *);
static void mos_ifmedia_sts(struct ifnet *, struct ifmediareq *);
static void mos_reset(struct mos_softc *sc);

static int mos_reg_read_1(struct mos_softc *, int);
static int mos_reg_read_2(struct mos_softc *, int);
static int mos_reg_write_1(struct mos_softc *, int, int);
static int mos_reg_write_2(struct mos_softc *, int, int);
static int mos_readmac(struct mos_softc *, uint8_t *);
static int mos_writemac(struct mos_softc *, uint8_t *);
static int mos_write_mcast(struct mos_softc *, u_char *);

static void mos_setmulti(struct usb_ether *);
static void mos_setpromisc(struct usb_ether *);

static const struct usb_config mos_config[MOS_ENDPT_MAX] = {

        [MOS_ENDPT_TX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_OUT,
                .bufsize = (MCLBYTES + 2),
                .flags = {.pipe_bof = 1,.force_short_xfer = 1,},
                .callback = mos_bulk_write_callback,
                .timeout = 10000,
        },

        [MOS_ENDPT_RX] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .bufsize = (MCLBYTES + 4 + ETHER_CRC_LEN),
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
                .callback = mos_bulk_read_callback,
        },

        [MOS_ENDPT_INTR] = {
                .type = UE_INTERRUPT,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
                .bufsize = 0,
                .callback = mos_intr_callback,
        },
};

static device_method_t mos_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe, mos_probe),
        DEVMETHOD(device_attach, mos_attach),
        DEVMETHOD(device_detach, mos_detach),

        /* bus interface */
        DEVMETHOD(bus_print_child, bus_generic_print_child),
        DEVMETHOD(bus_driver_added, bus_generic_driver_added),

        /* MII interface */
        DEVMETHOD(miibus_readreg, mos_miibus_readreg),
        DEVMETHOD(miibus_writereg, mos_miibus_writereg),
        DEVMETHOD(miibus_statchg, mos_miibus_statchg),

        {0, 0}
};

static driver_t mos_driver = {
        .name = "mos",
        .methods = mos_methods,
        .size = sizeof(struct mos_softc)
};

static devclass_t mos_devclass;

DRIVER_MODULE(mos, uhub, mos_driver, mos_devclass, NULL, 0);
DRIVER_MODULE(miibus, mos, miibus_driver, miibus_devclass, 0, 0);
MODULE_DEPEND(mos, uether, 1, 1, 1);
MODULE_DEPEND(mos, usb, 1, 1, 1);
MODULE_DEPEND(mos, ether, 1, 1, 1);
MODULE_DEPEND(mos, miibus, 1, 1, 1);

static const struct usb_ether_methods mos_ue_methods = {
        .ue_attach_post = mos_attach_post,
        .ue_start = mos_start,
        .ue_init = mos_init,
        .ue_stop = mos_stop,
        .ue_tick = mos_tick,
        .ue_setmulti = mos_setmulti,
        .ue_setpromisc = mos_setpromisc,
        .ue_mii_upd = mos_ifmedia_upd,
        .ue_mii_sts = mos_ifmedia_sts,
};


static int
mos_reg_read_1(struct mos_softc *sc, int reg)
{
        struct usb_device_request req;
        usb_error_t err;
        uByte val = 0;

        req.bmRequestType = UT_READ_VENDOR_DEVICE;
        req.bRequest = MOS_UR_READREG;
        USETW(req.wValue, 0);
        USETW(req.wIndex, reg);
        USETW(req.wLength, 1);

        err = uether_do_request(&sc->sc_ue, &req, &val, 1000);

        if (err) {
                MOS_DPRINTFN("mos_reg_read_1 error, reg: %d\n", reg);
                return (-1);
        }
        return (val);
}

static int
mos_reg_read_2(struct mos_softc *sc, int reg)
{
        struct usb_device_request req;
        usb_error_t err;
        uWord val;

        USETW(val, 0);

        req.bmRequestType = UT_READ_VENDOR_DEVICE;
        req.bRequest = MOS_UR_READREG;
        USETW(req.wValue, 0);
        USETW(req.wIndex, reg);
        USETW(req.wLength, 2);

        err = uether_do_request(&sc->sc_ue, &req, &val, 1000);

        if (err) {
                MOS_DPRINTFN("mos_reg_read_2 error, reg: %d", reg);
                return (-1);
        }
        return (UGETW(val));
}

static int
mos_reg_write_1(struct mos_softc *sc, int reg, int aval)
{
        struct usb_device_request req;
        usb_error_t err;
        uByte val;
        val = aval;

        req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
        req.bRequest = MOS_UR_WRITEREG;
        USETW(req.wValue, 0);
        USETW(req.wIndex, reg);
        USETW(req.wLength, 1);

        err = uether_do_request(&sc->sc_ue, &req, &val, 1000);

        if (err) {
                MOS_DPRINTFN("mos_reg_write_1 error, reg: %d", reg);
                return (-1);
        }
        return (0);
}

static int
mos_reg_write_2(struct mos_softc *sc, int reg, int aval)
{
        struct usb_device_request req;
        usb_error_t err;
        uWord val;

        USETW(val, aval);

        req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
        req.bRequest = MOS_UR_WRITEREG;
        USETW(req.wValue, 0);
        USETW(req.wIndex, reg);
        USETW(req.wLength, 2);

        err = uether_do_request(&sc->sc_ue, &req, &val, 1000);

        if (err) {
                MOS_DPRINTFN("mos_reg_write_2 error, reg: %d", reg);
                return (-1);
        }
        return (0);
}

static int
mos_readmac(struct mos_softc *sc, u_char *mac)
{
        struct usb_device_request req;
        usb_error_t err;

        req.bmRequestType = UT_READ_VENDOR_DEVICE;
        req.bRequest = MOS_UR_READREG;
        USETW(req.wValue, 0);
        USETW(req.wIndex, MOS_MAC);
        USETW(req.wLength, ETHER_ADDR_LEN);

        err = uether_do_request(&sc->sc_ue, &req, mac, 1000);

        if (err) {
                return (-1);
        }
        return (0);
}

static int
mos_writemac(struct mos_softc *sc, uint8_t *mac)
{
        struct usb_device_request req;
        usb_error_t err;

        req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
        req.bRequest = MOS_UR_WRITEREG;
        USETW(req.wValue, 0);
        USETW(req.wIndex, MOS_MAC);
        USETW(req.wLength, ETHER_ADDR_LEN);

        err = uether_do_request(&sc->sc_ue, &req, mac, 1000);

        if (err) {
                MOS_DPRINTFN("mos_writemac error");
                return (-1);
        }
        return (0);
}

static int
mos_write_mcast(struct mos_softc *sc, u_char *hashtbl)
{
        struct usb_device_request req;
        usb_error_t err;

        req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
        req.bRequest = MOS_UR_WRITEREG;
        USETW(req.wValue, 0);
        USETW(req.wIndex, MOS_MCAST_TABLE);
        USETW(req.wLength, 8);

        err = uether_do_request(&sc->sc_ue, &req, hashtbl, 1000);

        if (err) {
                MOS_DPRINTFN("mos_reg_mcast error");
                return (-1);
        }
        return (0);
}

static int
mos_miibus_readreg(struct device *dev, int phy, int reg)
{
        struct mos_softc *sc = device_get_softc(dev);
        uWord val;
        int i, res, locked;

        USETW(val, 0);

        locked = mtx_owned(&sc->sc_mtx);
        if (!locked)
                MOS_LOCK(sc);

        mos_reg_write_2(sc, MOS_PHY_DATA, 0);
        mos_reg_write_1(sc, MOS_PHY_CTL, (phy & MOS_PHYCTL_PHYADDR) |
            MOS_PHYCTL_READ);
        mos_reg_write_1(sc, MOS_PHY_STS, (reg & MOS_PHYSTS_PHYREG) |
            MOS_PHYSTS_PENDING);

        for (i = 0; i < MOS_TIMEOUT; i++) {
                if (mos_reg_read_1(sc, MOS_PHY_STS) & MOS_PHYSTS_READY)
                        break;
        }
        if (i == MOS_TIMEOUT) {
                MOS_DPRINTFN("MII read timeout");
        }
        res = mos_reg_read_2(sc, MOS_PHY_DATA);

        if (!locked)
                MOS_UNLOCK(sc);
        return (res);
}

static int
mos_miibus_writereg(device_t dev, int phy, int reg, int val)
{
        struct mos_softc *sc = device_get_softc(dev);
        int i, locked;

        locked = mtx_owned(&sc->sc_mtx);
        if (!locked)
                MOS_LOCK(sc);

        mos_reg_write_2(sc, MOS_PHY_DATA, val);
        mos_reg_write_1(sc, MOS_PHY_CTL, (phy & MOS_PHYCTL_PHYADDR) |
            MOS_PHYCTL_WRITE);
        mos_reg_write_1(sc, MOS_PHY_STS, (reg & MOS_PHYSTS_PHYREG) |
            MOS_PHYSTS_PENDING);

        for (i = 0; i < MOS_TIMEOUT; i++) {
                if (mos_reg_read_1(sc, MOS_PHY_STS) & MOS_PHYSTS_READY)
                        break;
        }
        if (i == MOS_TIMEOUT)
                MOS_DPRINTFN("MII write timeout");

        if (!locked)
                MOS_UNLOCK(sc);
        return 0;
}

static void
mos_miibus_statchg(device_t dev)
{
        struct mos_softc *sc = device_get_softc(dev);
        struct mii_data *mii = GET_MII(sc);
        int val, err, locked;

        locked = mtx_owned(&sc->sc_mtx);
        if (!locked)
                MOS_LOCK(sc);

        /* disable RX, TX prior to changing FDX, SPEEDSEL */
        val = mos_reg_read_1(sc, MOS_CTL);
        val &= ~(MOS_CTL_TX_ENB | MOS_CTL_RX_ENB);
        mos_reg_write_1(sc, MOS_CTL, val);

        /* reset register which counts dropped frames */
        mos_reg_write_1(sc, MOS_FRAME_DROP_CNT, 0);

        if ((mii->mii_media_active & IFM_GMASK) == IFM_FDX)
                val |= MOS_CTL_FDX_ENB;
        else
                val &= ~(MOS_CTL_FDX_ENB);

        switch (IFM_SUBTYPE(mii->mii_media_active)) {
        case IFM_100_TX:
                val |= MOS_CTL_SPEEDSEL;
                break;
        case IFM_10_T:
                val &= ~(MOS_CTL_SPEEDSEL);
                break;
        }

        /* re-enable TX, RX */
        val |= (MOS_CTL_TX_ENB | MOS_CTL_RX_ENB);
        err = mos_reg_write_1(sc, MOS_CTL, val);

        if (err)
                MOS_DPRINTFN("media change failed");

        if (!locked)
                MOS_UNLOCK(sc);
}

/*
 * Set media options.
 */
static int
mos_ifmedia_upd(struct ifnet *ifp)
{
        struct mos_softc *sc = ifp->if_softc;
        struct mii_data *mii = GET_MII(sc);
        struct mii_softc *miisc;

        MOS_LOCK_ASSERT(sc, MA_OWNED);

        sc->mos_link = 0;
        if (mii->mii_instance) {
                LIST_FOREACH(miisc, &mii->mii_phys, mii_list)
                    mii_phy_reset(miisc);
        }
        mii_mediachg(mii);
        return (0);
}

/*
 * Report current media status.
 */
static void
mos_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
{
        struct mos_softc *sc = ifp->if_softc;
        struct mii_data *mii = GET_MII(sc);

        MOS_LOCK(sc);
        mii_pollstat(mii);
        MOS_UNLOCK(sc);

        ifmr->ifm_active = mii->mii_media_active;
        ifmr->ifm_status = mii->mii_media_status;
}

static void
mos_setpromisc(struct usb_ether *ue)
{
        struct mos_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);

        uint8_t rxmode;

        MOS_LOCK_ASSERT(sc, MA_OWNED);

        rxmode = mos_reg_read_1(sc, MOS_CTL);

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & IFF_PROMISC) {
                rxmode |= MOS_CTL_RX_PROMISC;
        } else {
                rxmode &= ~MOS_CTL_RX_PROMISC;
        }

        mos_reg_write_1(sc, MOS_CTL, rxmode);
}



static void
mos_setmulti(struct usb_ether *ue)
{
        struct mos_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);
        struct ifmultiaddr *ifma;

        uint32_t h = 0;
        uint8_t rxmode;
        uint8_t hashtbl[8] = {0, 0, 0, 0, 0, 0, 0, 0};
        int allmulti = 0;

        MOS_LOCK_ASSERT(sc, MA_OWNED);

        rxmode = mos_reg_read_1(sc, MOS_CTL);

        if (ifp->if_flags & IFF_ALLMULTI || ifp->if_flags & IFF_PROMISC)
                allmulti = 1;

        /* get all new ones */
        if_maddr_rlock(ifp);
        TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                if (ifma->ifma_addr->sa_family != AF_LINK) {
                        allmulti = 1;
                        continue;
                };
                h = ether_crc32_be(LLADDR((struct sockaddr_dl *)
                    ifma->ifma_addr), ETHER_ADDR_LEN) >> 26;
                hashtbl[h / 8] |= 1 << (h % 8);
        }
        if_maddr_runlock(ifp);

        /* now program new ones */
        if (allmulti == 1) {
                rxmode |= MOS_CTL_ALLMULTI;
                mos_reg_write_1(sc, MOS_CTL, rxmode);
        } else {
                rxmode &= ~MOS_CTL_ALLMULTI;
                mos_write_mcast(sc, (void *)&hashtbl);
                mos_reg_write_1(sc, MOS_CTL, rxmode);
        }
}

static void
mos_reset(struct mos_softc *sc)
{
        uint8_t ctl;

        ctl = mos_reg_read_1(sc, MOS_CTL);
        ctl &= ~(MOS_CTL_RX_PROMISC | MOS_CTL_ALLMULTI | MOS_CTL_TX_ENB |
            MOS_CTL_RX_ENB);
        /* Disable RX, TX, promiscuous and allmulticast mode */
        mos_reg_write_1(sc, MOS_CTL, ctl);

        /* Reset frame drop counter register to zero */
        mos_reg_write_1(sc, MOS_FRAME_DROP_CNT, 0);

        /* Wait a little while for the chip to get its brains in order. */
        usb_pause_mtx(&sc->sc_mtx, hz / 1000);
        return;
}

static void
mos_chip_init(struct mos_softc *sc)
{
        int i;

        /*
         * Rev.C devices have a pause threshold register which needs to be set
         * at startup.
         */
        if (mos_reg_read_1(sc, MOS_PAUSE_TRHD) != -1) {
                for (i = 0; i < MOS_PAUSE_REWRITES; i++)
                        mos_reg_write_1(sc, MOS_PAUSE_TRHD, 0);
        }
        sc->mos_phyaddrs[0] = 1;
        sc->mos_phyaddrs[1] = 0xFF;
}

/*
 * Probe for a MCS7x30 chip.
 */
static int
mos_probe(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        int retval;

        if (uaa->usb_mode != USB_MODE_HOST) {
                return (ENXIO);
        }
        if (uaa->info.bConfigIndex != 0) {
                return (ENXIO);
        }
        if (uaa->info.bIfaceIndex != 0) {
                return (ENXIO);
        }

        retval = usbd_lookup_id_by_uaa(mos_devs, sizeof(mos_devs), uaa);
        return retval;
}

/*
 * Attach the interface. Allocate softc structures, do ifmedia
 * setup and ethernet/BPF attach.
 */
static int
mos_attach(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        struct mos_softc *sc = device_get_softc(dev);
        struct usb_ether *ue = &sc->sc_ue;
        uint8_t iface_index;
        int error;

        sc->mos_flags = USB_GET_DRIVER_INFO(uaa);

        device_set_usb_desc(dev);
        mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);

        iface_index = MOS_IFACE_IDX;
        error = usbd_transfer_setup(uaa->device, &iface_index,
            sc->sc_xfer, mos_config, MOS_ENDPT_MAX,
            sc, &sc->sc_mtx);

        if (error) {
                device_printf(dev, "allocating USB transfers failed\n");
                goto detach;
        }
        ue->ue_sc = sc;
        ue->ue_dev = dev;
        ue->ue_udev = uaa->device;
        ue->ue_mtx = &sc->sc_mtx;
        ue->ue_methods = &mos_ue_methods;


        if (sc->mos_flags & MCS7730) {
                MOS_DPRINTFN("model: MCS7730");
        } else if (sc->mos_flags & MCS7830) {
                MOS_DPRINTFN("model: MCS7830");
        }
        error = uether_ifattach(ue);
        if (error) {
                device_printf(dev, "could not attach interface\n");
                goto detach;
        }
        return (0);


detach:
        mos_detach(dev);
        return (ENXIO);
}


static void
mos_attach_post(struct usb_ether *ue)
{
        struct mos_softc *sc = uether_getsc(ue);
        int err;

        /* Read MAC address, inform the world. */
        err = mos_readmac(sc, ue->ue_eaddr);

        if (err)
          MOS_DPRINTFN("couldn't get MAC address");

        MOS_DPRINTFN("address: %s", ether_sprintf(ue->ue_eaddr));

        mos_chip_init(sc);
}

static int
mos_detach(device_t dev)
{
        struct mos_softc *sc = device_get_softc(dev);
        struct usb_ether *ue = &sc->sc_ue;

        usbd_transfer_unsetup(sc->sc_xfer, MOS_ENDPT_MAX);
        uether_ifdetach(ue);
        mtx_destroy(&sc->sc_mtx);

        return (0);
}




/*
 * A frame has been uploaded: pass the resulting mbuf chain up to
 * the higher level protocols.
 */
static void
mos_bulk_read_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct mos_softc *sc = usbd_xfer_softc(xfer);
        struct usb_ether *ue = &sc->sc_ue;
        struct ifnet *ifp = uether_getifp(ue);

        uint8_t rxstat = 0;
        uint32_t actlen;
        uint16_t pktlen = 0;
        struct usb_page_cache *pc;

        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
        pc = usbd_xfer_get_frame(xfer, 0);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                MOS_DPRINTFN("actlen : %d", actlen);
                if (actlen <= 1) {
                        ifp->if_ierrors++;
                        goto tr_setup;
                }
                /* evaluate status byte at the end */
                usbd_copy_out(pc, actlen - sizeof(rxstat), &rxstat,
                    sizeof(rxstat));

                if (rxstat != MOS_RXSTS_VALID) {
                        MOS_DPRINTFN("erroneous frame received");
                        if (rxstat & MOS_RXSTS_SHORT_FRAME)
                                MOS_DPRINTFN("frame size less than 64 bytes");
                        if (rxstat & MOS_RXSTS_LARGE_FRAME)
                                MOS_DPRINTFN("frame size larger than 1532 bytes");
                        if (rxstat & MOS_RXSTS_CRC_ERROR)
                                MOS_DPRINTFN("CRC error");
                        if (rxstat & MOS_RXSTS_ALIGN_ERROR)
                                MOS_DPRINTFN("alignment error");
                        ifp->if_ierrors++;
                        goto tr_setup;
                }
                /* Remember the last byte was used for the status fields */
                pktlen = actlen - 1;
                if (pktlen < sizeof(struct ether_header)) {
                        MOS_DPRINTFN("error: pktlen %i is smaller than ether_header %i", pktlen, sizeof(struct ether_header));
                        ifp->if_ierrors++;
                        goto tr_setup;
                }
                uether_rxbuf(ue, pc, 0, actlen);
                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
                usbd_transfer_submit(xfer);
                uether_rxflush(ue);
                return;
        default:
                MOS_DPRINTFN("bulk read error, %s", usbd_errstr(error));
                if (error != USB_ERR_CANCELLED) {
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                MOS_DPRINTFN("start rx %i", usbd_xfer_max_len(xfer));
                return;
        }
}

/*
 * A frame was downloaded to the chip. It's safe for us to clean up
 * the list buffers.
 */
static void
mos_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct mos_softc *sc = usbd_xfer_softc(xfer);
        struct ifnet *ifp = uether_getifp(&sc->sc_ue);
        struct usb_page_cache *pc;
        struct mbuf *m;



        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                MOS_DPRINTFN("transfer of complete");
                ifp->if_opackets++;
                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                /*
                 * XXX: don't send anything if there is no link?
                 */
                IFQ_DRV_DEQUEUE(&ifp->if_snd, m);
                if (m == NULL)
                        return;

                pc = usbd_xfer_get_frame(xfer, 0);
                usbd_m_copy_in(pc, 0, m, 0, m->m_pkthdr.len);

                usbd_xfer_set_frame_len(xfer, 0, m->m_pkthdr.len);


                /*
                 * if there's a BPF listener, bounce a copy
                 * of this frame to him:
                 */
                BPF_MTAP(ifp, m);

                m_freem(m);

                usbd_transfer_submit(xfer);

                ifp->if_opackets++;
                return;
        default:
                MOS_DPRINTFN("usb error on tx: %s\n", usbd_errstr(error));
                ifp->if_oerrors++;
                if (error != USB_ERR_CANCELLED) {
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                return;
        }
}

static void
mos_tick(struct usb_ether *ue)
{
        struct mos_softc *sc = uether_getsc(ue);
        struct mii_data *mii = GET_MII(sc);

        MOS_LOCK_ASSERT(sc, MA_OWNED);

        mii_tick(mii);
        if (!sc->mos_link && mii->mii_media_status & IFM_ACTIVE &&
            IFM_SUBTYPE(mii->mii_media_active) != IFM_NONE) {
                MOS_DPRINTFN("got link");
                sc->mos_link++;
                mos_start(ue);
        }
}


static void
mos_start(struct usb_ether *ue)
{
        struct mos_softc *sc = uether_getsc(ue);

        /*
         * start the USB transfers, if not already started:
         */
        usbd_transfer_start(sc->sc_xfer[MOS_ENDPT_TX]);
        usbd_transfer_start(sc->sc_xfer[MOS_ENDPT_RX]);
        usbd_transfer_start(sc->sc_xfer[MOS_ENDPT_INTR]);
}

static void
mos_init(struct usb_ether *ue)
{
        struct mos_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);
        uint8_t rxmode;

        MOS_LOCK_ASSERT(sc, MA_OWNED);

        /* Cancel pending I/O and free all RX/TX buffers. */
        mos_reset(sc);

        /* Write MAC address */
        mos_writemac(sc, IF_LLADDR(ifp));

        /* Read and set transmitter IPG values */
        sc->mos_ipgs[0] = mos_reg_read_1(sc, MOS_IPG0);
        sc->mos_ipgs[1] = mos_reg_read_1(sc, MOS_IPG1);
        mos_reg_write_1(sc, MOS_IPG0, sc->mos_ipgs[0]);
        mos_reg_write_1(sc, MOS_IPG1, sc->mos_ipgs[1]);

        /*
         * Enable receiver and transmitter, bridge controls speed/duplex
         * mode
         */
        rxmode = mos_reg_read_1(sc, MOS_CTL);
        rxmode |= MOS_CTL_RX_ENB | MOS_CTL_TX_ENB | MOS_CTL_BS_ENB;
        rxmode &= ~(MOS_CTL_SLEEP);

        mos_setpromisc(ue);

        /* XXX: broadcast mode? */
        mos_reg_write_1(sc, MOS_CTL, rxmode);

        /* Load the multicast filter. */
        mos_setmulti(ue);

        ifp->if_drv_flags |= IFF_DRV_RUNNING;
        mos_start(ue);
}


static void
mos_intr_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct mos_softc *sc = usbd_xfer_softc(xfer);
        struct ifnet *ifp = uether_getifp(&sc->sc_ue);
        struct usb_page_cache *pc;
        uint32_t pkt;
        int actlen;

        ifp->if_oerrors++;

        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
        MOS_DPRINTFN("actlen %i", actlen);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:

                pc = usbd_xfer_get_frame(xfer, 0);
                usbd_copy_out(pc, 0, &pkt, sizeof(pkt));
                /* FALLTHROUGH */
        case USB_ST_SETUP:
tr_setup:
                return;
        default:
                if (error != USB_ERR_CANCELLED) {
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                return;
        }
}


/*
 * Stop the adapter and free any mbufs allocated to the
 * RX and TX lists.
 */
static void
mos_stop(struct usb_ether *ue)
{
        struct mos_softc *sc = uether_getsc(ue);
        struct ifnet *ifp = uether_getifp(ue);

        mos_reset(sc);

        MOS_LOCK_ASSERT(sc, MA_OWNED);
        ifp->if_drv_flags &= ~IFF_DRV_RUNNING;

        /* stop all the transfers, if not already stopped */
        usbd_transfer_stop(sc->sc_xfer[MOS_ENDPT_TX]);
        usbd_transfer_stop(sc->sc_xfer[MOS_ENDPT_RX]);
        usbd_transfer_stop(sc->sc_xfer[MOS_ENDPT_INTR]);

        sc->mos_link = 0;
}