[dragonfly.git] / sys / dev / netif / wb / if_wb.c

/*
 * Copyright (c) 1997, 1998
 *      Bill Paul <wpaul@ctr.columbia.edu>.  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.
 *
 * $FreeBSD: src/sys/pci/if_wb.c,v 1.26.2.6 2003/03/05 18:42:34 njl Exp $
 * $DragonFly: src/sys/dev/netif/wb/if_wb.c,v 1.30 2005/06/14 14:19:22 joerg Exp $
 */

/*
 * Winbond fast ethernet PCI NIC driver
 *
 * Supports various cheap network adapters based on the Winbond W89C840F
 * fast ethernet controller chip. This includes adapters manufactured by
 * Winbond itself and some made by Linksys.
 *
 * Written by Bill Paul <wpaul@ctr.columbia.edu>
 * Electrical Engineering Department
 * Columbia University, New York City
 */

/*
 * The Winbond W89C840F chip is a bus master; in some ways it resembles
 * a DEC 'tulip' chip, only not as complicated. Unfortunately, it has
 * one major difference which is that while the registers do many of
 * the same things as a tulip adapter, the offsets are different: where
 * tulip registers are typically spaced 8 bytes apart, the Winbond
 * registers are spaced 4 bytes apart. The receiver filter is also
 * programmed differently.
 * 
 * Like the tulip, the Winbond chip uses small descriptors containing
 * a status word, a control word and 32-bit areas that can either be used
 * to point to two external data blocks, or to point to a single block
 * and another descriptor in a linked list. Descriptors can be grouped
 * together in blocks to form fixed length rings or can be chained
 * together in linked lists. A single packet may be spread out over
 * several descriptors if necessary.
 *
 * For the receive ring, this driver uses a linked list of descriptors,
 * each pointing to a single mbuf cluster buffer, which us large enough
 * to hold an entire packet. The link list is looped back to created a
 * closed ring.
 *
 * For transmission, the driver creates a linked list of 'super descriptors'
 * which each contain several individual descriptors linked toghether.
 * Each 'super descriptor' contains WB_MAXFRAGS descriptors, which we
 * abuse as fragment pointers. This allows us to use a buffer managment
 * scheme very similar to that used in the ThunderLAN and Etherlink XL
 * drivers.
 *
 * Autonegotiation is performed using the external PHY via the MII bus.
 * The sample boards I have all use a Davicom PHY.
 *
 * Note: the author of the Linux driver for the Winbond chip alludes
 * to some sort of flaw in the chip's design that seems to mandate some
 * drastic workaround which signigicantly impairs transmit performance.
 * I have no idea what he's on about: transmit performance with all
 * three of my test boards seems fine.
 */

#include "opt_bdg.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/queue.h>
#include <sys/thread2.h>

#include <net/if.h>
#include <net/ifq_var.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_dl.h>
#include <net/if_media.h>

#include <net/bpf.h>

#include <vm/vm.h>              /* for vtophys */
#include <vm/pmap.h>            /* for vtophys */
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/rman.h>

#include <bus/pci/pcireg.h>
#include <bus/pci/pcivar.h>

#include <dev/netif/mii_layer/mii.h>
#include <dev/netif/mii_layer/miivar.h>

/* "controller miibus0" required.  See GENERIC if you get errors here. */
#include "miibus_if.h"

#define WB_USEIOSPACE

#include "if_wbreg.h"

/*
 * Various supported device vendors/types and their names.
 */
static struct wb_type wb_devs[] = {
        { WB_VENDORID, WB_DEVICEID_840F,
                "Winbond W89C840F 10/100BaseTX" },
        { CP_VENDORID, CP_DEVICEID_RL100,
                "Compex RL100-ATX 10/100baseTX" },
        { 0, 0, NULL }
};

static int      wb_probe(device_t);
static int      wb_attach(device_t);
static int      wb_detach(device_t);

static void     wb_bfree(void *);
static int      wb_newbuf(struct wb_softc *, struct wb_chain_onefrag *,
                          struct mbuf *);
static int      wb_encap(struct wb_softc *, struct wb_chain *, struct mbuf *);

static void     wb_rxeof(struct wb_softc *);
static void     wb_rxeoc(struct wb_softc *);
static void     wb_txeof(struct wb_softc *);
static void     wb_txeoc(struct wb_softc *);
static void     wb_intr(void *);
static void     wb_tick(void *);
static void     wb_start(struct ifnet *);
static int      wb_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
static void     wb_init(void *);
static void     wb_stop(struct wb_softc *);
static void     wb_watchdog(struct ifnet *);
static void     wb_shutdown(device_t);
static int      wb_ifmedia_upd(struct ifnet *);
static void     wb_ifmedia_sts(struct ifnet *, struct ifmediareq *);

static void     wb_eeprom_putbyte(struct wb_softc *, int);
static void     wb_eeprom_getword(struct wb_softc *, int, uint16_t *);
static void     wb_read_eeprom(struct wb_softc *, caddr_t, int, int);
static void     wb_mii_sync(struct wb_softc *);
static void     wb_mii_send(struct wb_softc *, uint32_t, int);
static int      wb_mii_readreg(struct wb_softc *, struct wb_mii_frame *);
static int      wb_mii_writereg(struct wb_softc *, struct wb_mii_frame *);

static void     wb_setcfg(struct wb_softc *, uint32_t);
static void     wb_setmulti(struct wb_softc *);
static void     wb_reset(struct wb_softc *);
static void     wb_fixmedia(struct wb_softc *);
static int      wb_list_rx_init(struct wb_softc *);
static int      wb_list_tx_init(struct wb_softc *);

static int      wb_miibus_readreg(device_t, int, int);
static int      wb_miibus_writereg(device_t, int, int, int);
static void     wb_miibus_statchg(device_t);

#ifdef WB_USEIOSPACE
#define WB_RES                  SYS_RES_IOPORT
#define WB_RID                  WB_PCI_LOIO
#else
#define WB_RES                  SYS_RES_MEMORY
#define WB_RID                  WB_PCI_LOMEM
#endif

static device_method_t wb_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         wb_probe),
        DEVMETHOD(device_attach,        wb_attach),
        DEVMETHOD(device_detach,        wb_detach),
        DEVMETHOD(device_shutdown,      wb_shutdown),

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

        /* MII interface */
        DEVMETHOD(miibus_readreg,       wb_miibus_readreg),
        DEVMETHOD(miibus_writereg,      wb_miibus_writereg),
        DEVMETHOD(miibus_statchg,       wb_miibus_statchg),
        { 0, 0 }
};

static DEFINE_CLASS_0(wb, wb_driver, wb_methods, sizeof(struct wb_softc));
static devclass_t wb_devclass;

DECLARE_DUMMY_MODULE(if_wb);
DRIVER_MODULE(if_wb, pci, wb_driver, wb_devclass, 0, 0);
DRIVER_MODULE(miibus, wb, miibus_driver, miibus_devclass, 0, 0);

#define WB_SETBIT(sc, reg, x)                           \
        CSR_WRITE_4(sc, reg, CSR_READ_4(sc, reg) | (x))

#define WB_CLRBIT(sc, reg, x)                           \
        CSR_WRITE_4(sc, reg, CSR_READ_4(sc, reg) & ~(x))

#define SIO_SET(x)                                      \
        CSR_WRITE_4(sc, WB_SIO, CSR_READ_4(sc, WB_SIO) | (x))

#define SIO_CLR(x)                                      \
        CSR_WRITE_4(sc, WB_SIO, CSR_READ_4(sc, WB_SIO) & ~(x))

/*
 * Send a read command and address to the EEPROM, check for ACK.
 */
static void
wb_eeprom_putbyte(struct wb_softc *sc, int addr)
{
        int d, i;

        d = addr | WB_EECMD_READ;

        /*
         * Feed in each bit and stobe the clock.
         */
        for (i = 0x400; i; i >>= 1) {
                if (d & i)
                        SIO_SET(WB_SIO_EE_DATAIN);
                else
                        SIO_CLR(WB_SIO_EE_DATAIN);
                DELAY(100);
                SIO_SET(WB_SIO_EE_CLK);
                DELAY(150);
                SIO_CLR(WB_SIO_EE_CLK);
                DELAY(100);
        }
}

/*
 * Read a word of data stored in the EEPROM at address 'addr.'
 */
static void
wb_eeprom_getword(struct wb_softc *sc, int addr, uint16_t *dest)
{
        int i;
        uint16_t word = 0;

        /* Enter EEPROM access mode. */
        CSR_WRITE_4(sc, WB_SIO, WB_SIO_EESEL|WB_SIO_EE_CS);

        /*
         * Send address of word we want to read.
         */
        wb_eeprom_putbyte(sc, addr);

        CSR_WRITE_4(sc, WB_SIO, WB_SIO_EESEL|WB_SIO_EE_CS);

        /*
         * Start reading bits from EEPROM.
         */
        for (i = 0x8000; i; i >>= 1) {
                SIO_SET(WB_SIO_EE_CLK);
                DELAY(100);
                if (CSR_READ_4(sc, WB_SIO) & WB_SIO_EE_DATAOUT)
                        word |= i;
                SIO_CLR(WB_SIO_EE_CLK);
                DELAY(100);
        }

        /* Turn off EEPROM access mode. */
        CSR_WRITE_4(sc, WB_SIO, 0);

        *dest = word;
}

/*
 * Read a sequence of words from the EEPROM.
 */
static void
wb_read_eeprom(struct wb_softc *sc, caddr_t dest, int off, int cnt)
{
        int i;
        uint16_t word = 0, *ptr;

        for (i = 0; i < cnt; i++) {
                wb_eeprom_getword(sc, off + i, &word);
                ptr = (uint16_t *)(dest + (i * 2));
                *ptr = word;
        }
}

/*
 * Sync the PHYs by setting data bit and strobing the clock 32 times.
 */
static void
wb_mii_sync(struct wb_softc *sc)
{
        int i;

        SIO_SET(WB_SIO_MII_DIR | WB_SIO_MII_DATAIN);

        for (i = 0; i < 32; i++) {
                SIO_SET(WB_SIO_MII_CLK);
                DELAY(1);
                SIO_CLR(WB_SIO_MII_CLK);
                DELAY(1);
        }
}

/*
 * Clock a series of bits through the MII.
 */
static void
wb_mii_send(struct wb_softc *sc, uint32_t bits, int cnt)
{
        int i;

        SIO_CLR(WB_SIO_MII_CLK);

        for (i = (0x1 << (cnt - 1)); i; i >>= 1) {
                if (bits & i)
                        SIO_SET(WB_SIO_MII_DATAIN);
                else
                        SIO_CLR(WB_SIO_MII_DATAIN);
                DELAY(1);
                SIO_CLR(WB_SIO_MII_CLK);
                DELAY(1);
                SIO_SET(WB_SIO_MII_CLK);
        }
}

/*
 * Read an PHY register through the MII.
 */
static int
wb_mii_readreg(struct wb_softc *sc, struct wb_mii_frame *frame)
{
        int ack, i;

        crit_enter();

        /*
         * Set up frame for RX.
         */
        frame->mii_stdelim = WB_MII_STARTDELIM;
        frame->mii_opcode = WB_MII_READOP;
        frame->mii_turnaround = 0;
        frame->mii_data = 0;

        CSR_WRITE_4(sc, WB_SIO, 0);

        /*
         * Turn on data xmit.
         */
        SIO_SET(WB_SIO_MII_DIR);

        wb_mii_sync(sc);

        /*
         * Send command/address info.
         */
        wb_mii_send(sc, frame->mii_stdelim, 2);
        wb_mii_send(sc, frame->mii_opcode, 2);
        wb_mii_send(sc, frame->mii_phyaddr, 5);
        wb_mii_send(sc, frame->mii_regaddr, 5);

        /* Idle bit */
        SIO_CLR((WB_SIO_MII_CLK | WB_SIO_MII_DATAIN));
        DELAY(1);
        SIO_SET(WB_SIO_MII_CLK);
        DELAY(1);

        /* Turn off xmit. */
        SIO_CLR(WB_SIO_MII_DIR);
        /* Check for ack */
        SIO_CLR(WB_SIO_MII_CLK);
        DELAY(1);
        ack = CSR_READ_4(sc, WB_SIO) & WB_SIO_MII_DATAOUT;
        SIO_SET(WB_SIO_MII_CLK);
        DELAY(1);
        SIO_CLR(WB_SIO_MII_CLK);
        DELAY(1);
        SIO_SET(WB_SIO_MII_CLK);
        DELAY(1);

        /*
         * Now try reading data bits. If the ack failed, we still
         * need to clock through 16 cycles to keep the PHY(s) in sync.
         */
        if (ack) {
                for(i = 0; i < 16; i++) {
                        SIO_CLR(WB_SIO_MII_CLK);
                        DELAY(1);
                        SIO_SET(WB_SIO_MII_CLK);
                        DELAY(1);
                }
                goto fail;
        }

        for (i = 0x8000; i; i >>= 1) {
                SIO_CLR(WB_SIO_MII_CLK);
                DELAY(1);
                if (!ack) {
                        if (CSR_READ_4(sc, WB_SIO) & WB_SIO_MII_DATAOUT)
                                frame->mii_data |= i;
                        DELAY(1);
                }
                SIO_SET(WB_SIO_MII_CLK);
                DELAY(1);
        }

fail:

        SIO_CLR(WB_SIO_MII_CLK);
        DELAY(1);
        SIO_SET(WB_SIO_MII_CLK);
        DELAY(1);

        crit_exit();

        if (ack)
                return(1);
        return(0);
}

/*
 * Write to a PHY register through the MII.
 */
static int
wb_mii_writereg(struct wb_softc *sc, struct wb_mii_frame *frame)        
{

        crit_enter();
        /*
         * Set up frame for TX.
         */

        frame->mii_stdelim = WB_MII_STARTDELIM;
        frame->mii_opcode = WB_MII_WRITEOP;
        frame->mii_turnaround = WB_MII_TURNAROUND;
        
        /*
         * Turn on data output.
         */
        SIO_SET(WB_SIO_MII_DIR);

        wb_mii_sync(sc);

        wb_mii_send(sc, frame->mii_stdelim, 2);
        wb_mii_send(sc, frame->mii_opcode, 2);
        wb_mii_send(sc, frame->mii_phyaddr, 5);
        wb_mii_send(sc, frame->mii_regaddr, 5);
        wb_mii_send(sc, frame->mii_turnaround, 2);
        wb_mii_send(sc, frame->mii_data, 16);

        /* Idle bit. */
        SIO_SET(WB_SIO_MII_CLK);
        DELAY(1);
        SIO_CLR(WB_SIO_MII_CLK);
        DELAY(1);

        /*
         * Turn off xmit.
         */
        SIO_CLR(WB_SIO_MII_DIR);

        crit_exit();

        return(0);
}

static int
wb_miibus_readreg(device_t dev, int phy, int reg)
{
        struct wb_softc *sc = device_get_softc(dev);
        struct wb_mii_frame frame;

        bzero(&frame, sizeof(frame));

        frame.mii_phyaddr = phy;
        frame.mii_regaddr = reg;
        wb_mii_readreg(sc, &frame);

        return(frame.mii_data);
}

static int
wb_miibus_writereg(device_t dev, int phy, int reg, int data)
{
        struct wb_softc *sc = device_get_softc(dev);
        struct wb_mii_frame frame;

        bzero(&frame, sizeof(frame));

        frame.mii_phyaddr = phy;
        frame.mii_regaddr = reg;
        frame.mii_data = data;

        wb_mii_writereg(sc, &frame);

        return(0);
}

static void
wb_miibus_statchg(device_t dev)
{
        struct wb_softc *sc = device_get_softc(dev);
        struct mii_data *mii;

        mii = device_get_softc(sc->wb_miibus);
        wb_setcfg(sc, mii->mii_media_active);
}

/*
 * Program the 64-bit multicast hash filter.
 */
static void
wb_setmulti(struct wb_softc *sc)
{
        struct ifnet *ifp = &sc->arpcom.ac_if;
        int h = 0, mcnt = 0;
        uint32_t hashes[2] = { 0, 0 };
        struct ifmultiaddr *ifma;
        uint32_t rxfilt;

        rxfilt = CSR_READ_4(sc, WB_NETCFG);

        if (ifp->if_flags & IFF_ALLMULTI || ifp->if_flags & IFF_PROMISC) {
                rxfilt |= WB_NETCFG_RX_MULTI;
                CSR_WRITE_4(sc, WB_NETCFG, rxfilt);
                CSR_WRITE_4(sc, WB_MAR0, 0xFFFFFFFF);
                CSR_WRITE_4(sc, WB_MAR1, 0xFFFFFFFF);
                return;
        }

        /* first, zot all the existing hash bits */
        CSR_WRITE_4(sc, WB_MAR0, 0);
        CSR_WRITE_4(sc, WB_MAR1, 0);

        /* now program new ones */
        LIST_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;
                h = ~ether_crc32_be(LLADDR((struct sockaddr_dl *)
                    ifma->ifma_addr), ETHER_ADDR_LEN) >> 26;
                if (h < 32)
                        hashes[0] |= (1 << h);
                else
                        hashes[1] |= (1 << (h - 32));
                mcnt++;
        }

        if (mcnt)
                rxfilt |= WB_NETCFG_RX_MULTI;
        else
                rxfilt &= ~WB_NETCFG_RX_MULTI;

        CSR_WRITE_4(sc, WB_MAR0, hashes[0]);
        CSR_WRITE_4(sc, WB_MAR1, hashes[1]);
        CSR_WRITE_4(sc, WB_NETCFG, rxfilt);
}

/*
 * The Winbond manual states that in order to fiddle with the
 * 'full-duplex' and '100Mbps' bits in the netconfig register, we
 * first have to put the transmit and/or receive logic in the idle state.
 */
static void
wb_setcfg(struct wb_softc *sc, uint32_t media)
{
        int i, restart = 0;

        if (CSR_READ_4(sc, WB_NETCFG) & (WB_NETCFG_TX_ON | WB_NETCFG_RX_ON)) {
                restart = 1;
                WB_CLRBIT(sc, WB_NETCFG, (WB_NETCFG_TX_ON | WB_NETCFG_RX_ON));

                for (i = 0; i < WB_TIMEOUT; i++) {
                        DELAY(10);
                        if ((CSR_READ_4(sc, WB_ISR) & WB_ISR_TX_IDLE) &&
                                (CSR_READ_4(sc, WB_ISR) & WB_ISR_RX_IDLE))
                                break;
                }

                if (i == WB_TIMEOUT) {
                        if_printf(&sc->arpcom.ac_if, "failed to force tx and "
                                  "rx to idle state\n");
                }
        }

        if (IFM_SUBTYPE(media) == IFM_10_T)
                WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_100MBPS);
        else
                WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_100MBPS);

        if ((media & IFM_GMASK) == IFM_FDX)
                WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_FULLDUPLEX);
        else
                WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_FULLDUPLEX);

        if (restart)
                WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_TX_ON | WB_NETCFG_RX_ON);
}

static void
wb_reset(struct wb_softc *sc)
{
        int i;
        struct mii_data *mii;

        CSR_WRITE_4(sc, WB_NETCFG, 0);
        CSR_WRITE_4(sc, WB_BUSCTL, 0);
        CSR_WRITE_4(sc, WB_TXADDR, 0);
        CSR_WRITE_4(sc, WB_RXADDR, 0);

        WB_SETBIT(sc, WB_BUSCTL, WB_BUSCTL_RESET);
        WB_SETBIT(sc, WB_BUSCTL, WB_BUSCTL_RESET);

        for (i = 0; i < WB_TIMEOUT; i++) {
                DELAY(10);
                if ((CSR_READ_4(sc, WB_BUSCTL) & WB_BUSCTL_RESET) == 0)
                        break;
        }
        if (i == WB_TIMEOUT)
                if_printf(&sc->arpcom.ac_if, "reset never completed!\n");

        /* Wait a little while for the chip to get its brains in order. */
        DELAY(1000);

        if (sc->wb_miibus == NULL)
                return;

        mii = device_get_softc(sc->wb_miibus);
        if (mii == NULL)
                return;

        if (mii->mii_instance) {
                struct mii_softc *miisc;
                LIST_FOREACH(miisc, &mii->mii_phys, mii_list)
                        mii_phy_reset(miisc);
        }
}

static void
wb_fixmedia(struct wb_softc *sc)
{
        struct mii_data *mii;
        uint32_t media;

        if (sc->wb_miibus == NULL)
                return;

        mii = device_get_softc(sc->wb_miibus);

        mii_pollstat(mii);
        if (IFM_SUBTYPE(mii->mii_media_active) == IFM_10_T) {
                media = mii->mii_media_active & ~IFM_10_T;
                media |= IFM_100_TX;
        } else if (IFM_SUBTYPE(mii->mii_media_active) == IFM_100_TX) {
                media = mii->mii_media_active & ~IFM_100_TX;
                media |= IFM_10_T;
        } else
                return;

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

/*
 * Probe for a Winbond chip. Check the PCI vendor and device
 * IDs against our list and return a device name if we find a match.
 */
static int wb_probe(device_t dev)
{
        struct wb_type *t;
        uint16_t vendor, product;

        vendor = pci_get_vendor(dev);
        product = pci_get_device(dev);

        for (t = wb_devs; t->wb_name != NULL; t++) {
                if (vendor == t->wb_vid && product == t->wb_did) {
                        device_set_desc(dev, t->wb_name);
                        return(0);
                }
        }

        return(ENXIO);
}

/*
 * Attach the interface. Allocate softc structures, do ifmedia
 * setup and ethernet/BPF attach.
 */
static int
wb_attach(device_t dev)
{
        u_char eaddr[ETHER_ADDR_LEN];
        struct wb_softc *sc;
        struct ifnet *ifp;
        int error = 0, rid;

        sc = device_get_softc(dev);
        callout_init(&sc->wb_stat_timer);

        /*
         * Handle power management nonsense.
         */
        if (pci_get_powerstate(dev) != PCI_POWERSTATE_D0) {
                uint32_t iobase, membase, irq;

                /* Save important PCI config data. */
                iobase = pci_read_config(dev, WB_PCI_LOIO, 4);
                membase = pci_read_config(dev, WB_PCI_LOMEM, 4);
                irq = pci_read_config(dev, WB_PCI_INTLINE, 4);

                /* Reset the power state. */
                device_printf(dev, "chip is in D%d power mode "
                "-- setting to D0\n", pci_get_powerstate(dev));
                pci_set_powerstate(dev, PCI_POWERSTATE_D0);

                /* Restore PCI config data. */
                pci_write_config(dev, WB_PCI_LOIO, iobase, 4);
                pci_write_config(dev, WB_PCI_LOMEM, membase, 4);
                pci_write_config(dev, WB_PCI_INTLINE, irq, 4);
        }

        pci_enable_busmaster(dev);

        rid = WB_RID;
        sc->wb_res = bus_alloc_resource_any(dev, WB_RES, &rid, RF_ACTIVE);

        if (sc->wb_res == NULL) {
                device_printf(dev, "couldn't map ports/memory\n");
                error = ENXIO;
                goto fail;
        }

        sc->wb_btag = rman_get_bustag(sc->wb_res);
        sc->wb_bhandle = rman_get_bushandle(sc->wb_res);

        /* Allocate interrupt */
        rid = 0;
        sc->wb_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
            RF_SHAREABLE | RF_ACTIVE);

        if (sc->wb_irq == NULL) {
                device_printf(dev, "couldn't map interrupt\n");
                error = ENXIO;
                goto fail;
        }

        /* Save the cache line size. */
        sc->wb_cachesize = pci_read_config(dev, WB_PCI_CACHELEN, 4) & 0xFF;

        ifp = &sc->arpcom.ac_if;
        if_initname(ifp, device_get_name(dev), device_get_unit(dev));

        /* Reset the adapter. */
        wb_reset(sc);

        /*
         * Get station address from the EEPROM.
         */
        wb_read_eeprom(sc, (caddr_t)&eaddr, 0, 3);

        sc->wb_ldata = contigmalloc(sizeof(struct wb_list_data) + 8, M_DEVBUF,
            M_WAITOK, 0, 0xffffffff, PAGE_SIZE, 0);

        if (sc->wb_ldata == NULL) {
                device_printf(dev, "no memory for list buffers!\n");
                error = ENXIO;
                goto fail;
        }

        bzero(sc->wb_ldata, sizeof(struct wb_list_data));

        ifp->if_softc = sc;
        ifp->if_mtu = ETHERMTU;
        ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        ifp->if_ioctl = wb_ioctl;
        ifp->if_start = wb_start;
        ifp->if_watchdog = wb_watchdog;
        ifp->if_init = wb_init;
        ifp->if_baudrate = 10000000;
        ifq_set_maxlen(&ifp->if_snd, WB_TX_LIST_CNT - 1);
        ifq_set_ready(&ifp->if_snd);

        /*
         * Do MII setup.
         */
        if (mii_phy_probe(dev, &sc->wb_miibus,
            wb_ifmedia_upd, wb_ifmedia_sts)) {
                error = ENXIO;
                goto fail;
        }

        /*
         * Call MI attach routine.
         */
        ether_ifattach(ifp, eaddr);

        error = bus_setup_intr(dev, sc->wb_irq, INTR_TYPE_NET,
                               wb_intr, sc, &sc->wb_intrhand, NULL);

        if (error) {
                device_printf(dev, "couldn't set up irq\n");
                ether_ifdetach(ifp);
                goto fail;
        }

        return(0);

fail:
        wb_detach(dev);
        return(error);
}

static int
wb_detach(device_t dev)
{
        struct wb_softc *sc = device_get_softc(dev);
        struct ifnet *ifp = &sc->arpcom.ac_if;

        crit_enter();

        if (device_is_attached(dev)) {
                if (bus_child_present(dev))
                        wb_stop(sc);
                ether_ifdetach(ifp);
        }

        if (sc->wb_miibus)
                device_delete_child(dev, sc->wb_miibus);
        bus_generic_detach(dev);

        if (sc->wb_intrhand)
                bus_teardown_intr(dev, sc->wb_irq, sc->wb_intrhand);
        crit_exit();
        if (sc->wb_irq);
                bus_release_resource(dev, SYS_RES_IRQ, 0, sc->wb_irq);
        if (sc->wb_res)
                bus_release_resource(dev, WB_RES, WB_RID, sc->wb_res);
        if (sc->wb_ldata_ptr) {
                contigfree(sc->wb_ldata_ptr, sizeof(struct wb_list_data) + 8,
                    M_DEVBUF);
        }

        return(0);
}

/*
 * Initialize the transmit descriptors.
 */
static int
wb_list_tx_init(struct wb_softc *sc)
{
        struct wb_chain_data *cd;
        struct wb_list_data *ld;
        int i, nexti;

        cd = &sc->wb_cdata;
        ld = sc->wb_ldata;

        for (i = 0; i < WB_TX_LIST_CNT; i++) {
                nexti = (i == WB_TX_LIST_CNT - 1) ? 0 : i + 1;
                cd->wb_tx_chain[i].wb_ptr = &ld->wb_tx_list[i];
                cd->wb_tx_chain[i].wb_nextdesc = &cd->wb_tx_chain[nexti];
        }

        cd->wb_tx_free = &cd->wb_tx_chain[0];
        cd->wb_tx_tail = cd->wb_tx_head = NULL;

        return(0);
}

/*
 * Initialize the RX descriptors and allocate mbufs for them. Note that
 * we arrange the descriptors in a closed ring, so that the last descriptor
 * points back to the first.
 */
static int
wb_list_rx_init(struct wb_softc *sc)
{
        struct wb_chain_data *cd;
        struct wb_list_data *ld;
        int i, nexti;

        cd = &sc->wb_cdata;
        ld = sc->wb_ldata;

        for (i = 0; i < WB_RX_LIST_CNT; i++) {
                cd->wb_rx_chain[i].wb_ptr = &ld->wb_rx_list[i];
                cd->wb_rx_chain[i].wb_buf = &ld->wb_rxbufs[i];
                if (wb_newbuf(sc, &cd->wb_rx_chain[i], NULL) == ENOBUFS)
                        return(ENOBUFS);
                nexti = (WB_RX_LIST_CNT - 1) ? 0 : i + 1;
                cd->wb_rx_chain[i].wb_nextdesc = &cd->wb_rx_chain[nexti];
                ld->wb_rx_list[i].wb_next =  vtophys(&ld->wb_rx_list[nexti]);
        }

        cd->wb_rx_head = &cd->wb_rx_chain[0];

        return(0);
}

static void
wb_bfree(void *arg)
{
}

/*
 * Initialize an RX descriptor and attach an MBUF cluster.
 */
static int
wb_newbuf(struct wb_softc *sc, struct wb_chain_onefrag *c, struct mbuf *m)
{
        struct mbuf *m_new = NULL;

        if (m == NULL) {
                MGETHDR(m_new, MB_DONTWAIT, MT_DATA);
                if (m_new == NULL)
                        return(ENOBUFS);

                m_new->m_data = m_new->m_ext.ext_buf = c->wb_buf;
                m_new->m_flags |= M_EXT;
                m_new->m_ext.ext_size = m_new->m_pkthdr.len =
                    m_new->m_len = WB_BUFBYTES;
                m_new->m_ext.ext_free = wb_bfree;
                m_new->m_ext.ext_ref = wb_bfree;
        } else {
                m_new = m;
                m_new->m_len = m_new->m_pkthdr.len = WB_BUFBYTES;
                m_new->m_data = m_new->m_ext.ext_buf;
        }

        m_adj(m_new, sizeof(uint64_t));

        c->wb_mbuf = m_new;
        c->wb_ptr->wb_data = vtophys(mtod(m_new, caddr_t));
        c->wb_ptr->wb_ctl = WB_RXCTL_RLINK | 1536;
        c->wb_ptr->wb_status = WB_RXSTAT;

        return(0);
}

/*
 * A frame has been uploaded: pass the resulting mbuf chain up to
 * the higher level protocols.
 */
static void
wb_rxeof(struct wb_softc *sc)
{
        struct ifnet *ifp = &sc->arpcom.ac_if;
        struct mbuf *m, *m0;
        struct wb_chain_onefrag *cur_rx;
        int total_len = 0;
        uint32_t rxstat;

        for (;;) {
                rxstat = sc->wb_cdata.wb_rx_head->wb_ptr->wb_status;
                if ((rxstat & WB_RXSTAT_OWN) == 0)
                        break;

                cur_rx = sc->wb_cdata.wb_rx_head;
                sc->wb_cdata.wb_rx_head = cur_rx->wb_nextdesc;

                m = cur_rx->wb_mbuf;

                if ((rxstat & WB_RXSTAT_MIIERR) ||
                    (WB_RXBYTES(cur_rx->wb_ptr->wb_status) < WB_MIN_FRAMELEN) ||
                    (WB_RXBYTES(cur_rx->wb_ptr->wb_status) > 1536) ||
                    (rxstat & WB_RXSTAT_LASTFRAG) == 0||
                    (rxstat & WB_RXSTAT_RXCMP) == 0) {
                        ifp->if_ierrors++;
                        wb_newbuf(sc, cur_rx, m);
                        if_printf(ifp, "receiver babbling: possible chip "
                                  "bug, forcing reset\n");
                        wb_fixmedia(sc);
                        wb_reset(sc);
                        wb_init(sc);
                        return;
                }

                if (rxstat & WB_RXSTAT_RXERR) {
                        ifp->if_ierrors++;
                        wb_newbuf(sc, cur_rx, m);
                        break;
                }

                /* No errors; receive the packet. */    
                total_len = WB_RXBYTES(cur_rx->wb_ptr->wb_status);

                /*
                 * XXX The Winbond chip includes the CRC with every
                 * received frame, and there's no way to turn this
                 * behavior off (at least, I can't find anything in
                 * the manual that explains how to do it) so we have
                 * to trim off the CRC manually.
                 */
                total_len -= ETHER_CRC_LEN;

                m0 = m_devget(mtod(m, char *) - ETHER_ALIGN,
                     total_len + ETHER_ALIGN, 0, ifp, NULL);
                wb_newbuf(sc, cur_rx, m);
                if (m0 == NULL) {
                        ifp->if_ierrors++;
                        break;
                }
                m_adj(m0, ETHER_ALIGN);
                m = m0;

                ifp->if_ipackets++;
                (*ifp->if_input)(ifp, m);
        }
}

static void
wb_rxeoc(struct wb_softc *sc)
{
        wb_rxeof(sc);

        WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_RX_ON);
        CSR_WRITE_4(sc, WB_RXADDR, vtophys(&sc->wb_ldata->wb_rx_list[0]));
        WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_RX_ON);
        if (CSR_READ_4(sc, WB_ISR) & WB_RXSTATE_SUSPEND)
                CSR_WRITE_4(sc, WB_RXSTART, 0xFFFFFFFF);
}

/*
 * A frame was downloaded to the chip. It's safe for us to clean up
 * the list buffers.
 */
static void
wb_txeof(struct wb_softc *sc)
{
        struct ifnet *ifp = &sc->arpcom.ac_if;
        struct wb_chain *cur_tx;

        /* Clear the timeout timer. */
        ifp->if_timer = 0;

        if (sc->wb_cdata.wb_tx_head == NULL)
                return;

        /*
         * Go through our tx list and free mbufs for those
         * frames that have been transmitted.
         */
        while(sc->wb_cdata.wb_tx_head->wb_mbuf != NULL) {
                uint32_t txstat;

                cur_tx = sc->wb_cdata.wb_tx_head;
                txstat = WB_TXSTATUS(cur_tx);

                if ((txstat & WB_TXSTAT_OWN) || txstat == WB_UNSENT)
                        break;

                if (txstat & WB_TXSTAT_TXERR) {
                        ifp->if_oerrors++;
                        if (txstat & WB_TXSTAT_ABORT)
                                ifp->if_collisions++;
                        if (txstat & WB_TXSTAT_LATECOLL)
                                ifp->if_collisions++;
                }

                ifp->if_collisions += (txstat & WB_TXSTAT_COLLCNT) >> 3;

                ifp->if_opackets++;
                m_freem(cur_tx->wb_mbuf);
                cur_tx->wb_mbuf = NULL;

                if (sc->wb_cdata.wb_tx_head == sc->wb_cdata.wb_tx_tail) {
                        sc->wb_cdata.wb_tx_head = NULL;
                        sc->wb_cdata.wb_tx_tail = NULL;
                        break;
                }

                sc->wb_cdata.wb_tx_head = cur_tx->wb_nextdesc;
        }
}

/*
 * TX 'end of channel' interrupt handler.
 */
static void
wb_txeoc(struct wb_softc *sc)
{
        struct ifnet *ifp = &sc->arpcom.ac_if;

        ifp->if_timer = 0;

        if (sc->wb_cdata.wb_tx_head == NULL) {
                ifp->if_flags &= ~IFF_OACTIVE;
                sc->wb_cdata.wb_tx_tail = NULL;
        } else if (WB_TXOWN(sc->wb_cdata.wb_tx_head) == WB_UNSENT) {
                WB_TXOWN(sc->wb_cdata.wb_tx_head) = WB_TXSTAT_OWN;
                ifp->if_timer = 5;
                CSR_WRITE_4(sc, WB_TXSTART, 0xFFFFFFFF);
        }
}

static void
wb_intr(void *arg)
{
        struct wb_softc *sc = arg;
        struct ifnet *ifp = &sc->arpcom.ac_if;
        uint32_t status;

        if ((ifp->if_flags & IFF_UP) == 0)
                return;

        /* Disable interrupts. */
        CSR_WRITE_4(sc, WB_IMR, 0x00000000);

        for (;;) {
                status = CSR_READ_4(sc, WB_ISR);
                if (status)
                        CSR_WRITE_4(sc, WB_ISR, status);

                if ((status & WB_INTRS) == 0)
                        break;

                if ((status & WB_ISR_RX_NOBUF) || (status & WB_ISR_RX_ERR)) {
                        ifp->if_ierrors++;
                        wb_reset(sc);
                        if (status & WB_ISR_RX_ERR)
                                wb_fixmedia(sc);
                        wb_init(sc);
                        continue;
                }

                if (status & WB_ISR_RX_OK)
                        wb_rxeof(sc);
        
                if (status & WB_ISR_RX_IDLE)
                        wb_rxeoc(sc);

                if (status & WB_ISR_TX_OK)
                        wb_txeof(sc);

                if (status & WB_ISR_TX_NOBUF)
                        wb_txeoc(sc);

                if (status & WB_ISR_TX_IDLE) {
                        wb_txeof(sc);
                        if (sc->wb_cdata.wb_tx_head != NULL) {
                                WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_TX_ON);
                                CSR_WRITE_4(sc, WB_TXSTART, 0xFFFFFFFF);
                        }
                }

                if (status & WB_ISR_TX_UNDERRUN) {
                        ifp->if_oerrors++;
                        wb_txeof(sc);
                        WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_TX_ON);
                        /* Jack up TX threshold */
                        sc->wb_txthresh += WB_TXTHRESH_CHUNK;
                        WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_TX_THRESH);
                        WB_SETBIT(sc, WB_NETCFG, WB_TXTHRESH(sc->wb_txthresh));
                        WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_TX_ON);
                }

                if (status & WB_ISR_BUS_ERR) {
                        wb_reset(sc);
                        wb_init(sc);
                }
        }

        /* Re-enable interrupts. */
        CSR_WRITE_4(sc, WB_IMR, WB_INTRS);

        if (!ifq_is_empty(&ifp->if_snd))
                wb_start(ifp);
}

static void
wb_tick(void *xsc)
{
        struct wb_softc *sc = xsc;
        struct mii_data *mii = device_get_softc(sc->wb_miibus);

        crit_enter();

        mii_tick(mii);

        callout_reset(&sc->wb_stat_timer, hz, wb_tick, sc);

        crit_exit();
}

/*
 * Encapsulate an mbuf chain in a descriptor by coupling the mbuf data
 * pointers to the fragment pointers.
 */
static int
wb_encap(struct wb_softc *sc, struct wb_chain *c, struct mbuf *m_head)
{
        struct wb_desc *f = NULL;
        struct mbuf *m;
        int frag, total_len;

        /*
         * Start packing the mbufs in this chain into
         * the fragment pointers. Stop when we run out
         * of fragments or hit the end of the mbuf chain.
         */
        total_len = 0;

        for (m = m_head, frag = 0; m != NULL; m = m->m_next) {
                if (m->m_len != 0) {
                        if (frag == WB_MAXFRAGS)
                                break;
                        total_len += m->m_len;
                        f = &c->wb_ptr->wb_frag[frag];
                        f->wb_ctl = WB_TXCTL_TLINK | m->m_len;
                        if (frag == 0) {
                                f->wb_ctl |= WB_TXCTL_FIRSTFRAG;
                                f->wb_status = 0;
                        } else {
                                f->wb_status = WB_TXSTAT_OWN;
                        }
                        f->wb_next = vtophys(&c->wb_ptr->wb_frag[frag + 1]);
                        f->wb_data = vtophys(mtod(m, vm_offset_t));
                        frag++;
                }
        }

        /*
         * Handle special case: we used up all 16 fragments,
         * but we have more mbufs left in the chain. Copy the
         * data into an mbuf cluster. Note that we don't
         * bother clearing the values in the other fragment
         * pointers/counters; it wouldn't gain us anything,
         * and would waste cycles.
         */
        if (m != NULL) {
                struct mbuf *m_new = NULL;

                MGETHDR(m_new, MB_DONTWAIT, MT_DATA);
                if (m_new == NULL)
                        return(1);
                if (m_head->m_pkthdr.len > MHLEN) {
                        MCLGET(m_new, MB_DONTWAIT);
                        if ((m_new->m_flags & M_EXT) == 0) {
                                m_freem(m_new);
                                return(1);
                        }
                }
                m_copydata(m_head, 0, m_head->m_pkthdr.len,
                    mtod(m_new, caddr_t));
                m_new->m_pkthdr.len = m_new->m_len = m_head->m_pkthdr.len;
                m_freem(m_head);
                m_head = m_new;
                f = &c->wb_ptr->wb_frag[0];
                f->wb_status = 0;
                f->wb_data = vtophys(mtod(m_new, caddr_t));
                f->wb_ctl = total_len = m_new->m_len;
                f->wb_ctl |= WB_TXCTL_TLINK|WB_TXCTL_FIRSTFRAG;
                frag = 1;
        }

        if (total_len < WB_MIN_FRAMELEN) {
                f = &c->wb_ptr->wb_frag[frag];
                f->wb_ctl = WB_MIN_FRAMELEN - total_len;
                f->wb_data = vtophys(&sc->wb_cdata.wb_pad);
                f->wb_ctl |= WB_TXCTL_TLINK;
                f->wb_status = WB_TXSTAT_OWN;
                frag++;
        }

        c->wb_mbuf = m_head;
        c->wb_lastdesc = frag - 1;
        WB_TXCTL(c) |= WB_TXCTL_LASTFRAG;
        WB_TXNEXT(c) = vtophys(&c->wb_nextdesc->wb_ptr->wb_frag[0]);

        return(0);
}

/*
 * Main transmit routine. To avoid having to do mbuf copies, we put pointers
 * to the mbuf data regions directly in the transmit lists. We also save a
 * copy of the pointers since the transmit list fragment pointers are
 * physical addresses.
 */
static void
wb_start(struct ifnet *ifp)
{
        struct wb_softc *sc = ifp->if_softc;
        struct mbuf *m_head = NULL;
        struct wb_chain *cur_tx = NULL, *start_tx;

        /*
         * Check for an available queue slot. If there are none,
         * punt.
         */
        if (sc->wb_cdata.wb_tx_free->wb_mbuf != NULL) {
                ifp->if_flags |= IFF_OACTIVE;
                return;
        }

        start_tx = sc->wb_cdata.wb_tx_free;

        while (sc->wb_cdata.wb_tx_free->wb_mbuf == NULL) {
                m_head = ifq_dequeue(&ifp->if_snd);
                if (m_head == NULL)
                        break;

                /* Pick a descriptor off the free list. */
                cur_tx = sc->wb_cdata.wb_tx_free;
                sc->wb_cdata.wb_tx_free = cur_tx->wb_nextdesc;

                /* Pack the data into the descriptor. */
                wb_encap(sc, cur_tx, m_head);

                if (cur_tx != start_tx)
                        WB_TXOWN(cur_tx) = WB_TXSTAT_OWN;

                BPF_MTAP(ifp, cur_tx->wb_mbuf);
        }

        /*
         * If there are no packets queued, bail.
         */
        if (cur_tx == NULL)
                return;

        /*
         * Place the request for the upload interrupt
         * in the last descriptor in the chain. This way, if
         * we're chaining several packets at once, we'll only
         * get an interupt once for the whole chain rather than
         * once for each packet.
         */
        WB_TXCTL(cur_tx) |= WB_TXCTL_FINT;
        cur_tx->wb_ptr->wb_frag[0].wb_ctl |= WB_TXCTL_FINT;
        sc->wb_cdata.wb_tx_tail = cur_tx;

        if (sc->wb_cdata.wb_tx_head == NULL) {
                sc->wb_cdata.wb_tx_head = start_tx;
                WB_TXOWN(start_tx) = WB_TXSTAT_OWN;
                CSR_WRITE_4(sc, WB_TXSTART, 0xFFFFFFFF);
        } else {
                /*
                 * We need to distinguish between the case where
                 * the own bit is clear because the chip cleared it
                 * and where the own bit is clear because we haven't
                 * set it yet. The magic value WB_UNSET is just some
                 * ramdomly chosen number which doesn't have the own
                 * bit set. When we actually transmit the frame, the
                 * status word will have _only_ the own bit set, so
                 * the txeoc handler will be able to tell if it needs
                 * to initiate another transmission to flush out pending
                 * frames.
                 */
                WB_TXOWN(start_tx) = WB_UNSENT;
        }

        /*
         * Set a timeout in case the chip goes out to lunch.
         */
        ifp->if_timer = 5;
}

static void
wb_init(void *xsc)
{
        struct wb_softc *sc = xsc;
        struct ifnet *ifp = &sc->arpcom.ac_if;
        int i;
        struct mii_data *mii;

        crit_enter();

        mii = device_get_softc(sc->wb_miibus);

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

        sc->wb_txthresh = WB_TXTHRESH_INIT;

        /*
         * Set cache alignment and burst length.
         */
#ifdef foo
        CSR_WRITE_4(sc, WB_BUSCTL, WB_BUSCTL_CONFIG);
        WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_TX_THRESH);
        WB_SETBIT(sc, WB_NETCFG, WB_TXTHRESH(sc->wb_txthresh));
#endif

        CSR_WRITE_4(sc, WB_BUSCTL, WB_BUSCTL_MUSTBEONE | WB_BUSCTL_ARBITRATION);
        WB_SETBIT(sc, WB_BUSCTL, WB_BURSTLEN_16LONG);
        switch(sc->wb_cachesize) {
        case 32:
                WB_SETBIT(sc, WB_BUSCTL, WB_CACHEALIGN_32LONG);
                break;
        case 16:
                WB_SETBIT(sc, WB_BUSCTL, WB_CACHEALIGN_16LONG);
                break;
        case 8:
                WB_SETBIT(sc, WB_BUSCTL, WB_CACHEALIGN_8LONG);
                break;
        case 0:
        default:
                WB_SETBIT(sc, WB_BUSCTL, WB_CACHEALIGN_NONE);
                break;
        }

        /* This doesn't tend to work too well at 100Mbps. */
        WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_TX_EARLY_ON);

        /* Init our MAC address */
        for (i = 0; i < ETHER_ADDR_LEN; i++)
                CSR_WRITE_1(sc, WB_NODE0 + i, sc->arpcom.ac_enaddr[i]);

        /* Init circular RX list. */
        if (wb_list_rx_init(sc) == ENOBUFS) {
                if_printf(ifp, "initialization failed: no "
                          "memory for rx buffers\n");
                wb_stop(sc);
                crit_exit();
                return;
        }

        /* Init TX descriptors. */
        wb_list_tx_init(sc);

        /* If we want promiscuous mode, set the allframes bit. */
        if (ifp->if_flags & IFF_PROMISC)
                WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_RX_ALLPHYS);
        else
                WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_RX_ALLPHYS);

        /*
         * Set capture broadcast bit to capture broadcast frames.
         */
        if (ifp->if_flags & IFF_BROADCAST)
                WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_RX_BROAD);
        else
                WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_RX_BROAD);

        /*
         * Program the multicast filter, if necessary.
         */
        wb_setmulti(sc);

        /*
         * Load the address of the RX list.
         */
        WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_RX_ON);
        CSR_WRITE_4(sc, WB_RXADDR, vtophys(&sc->wb_ldata->wb_rx_list[0]));

        /*
         * Enable interrupts.
         */
        CSR_WRITE_4(sc, WB_IMR, WB_INTRS);
        CSR_WRITE_4(sc, WB_ISR, 0xFFFFFFFF);

        /* Enable receiver and transmitter. */
        WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_RX_ON);
        CSR_WRITE_4(sc, WB_RXSTART, 0xFFFFFFFF);

        WB_CLRBIT(sc, WB_NETCFG, WB_NETCFG_TX_ON);
        CSR_WRITE_4(sc, WB_TXADDR, vtophys(&sc->wb_ldata->wb_tx_list[0]));
        WB_SETBIT(sc, WB_NETCFG, WB_NETCFG_TX_ON);

        mii_mediachg(mii);

        ifp->if_flags |= IFF_RUNNING;
        ifp->if_flags &= ~IFF_OACTIVE;

        crit_exit();

        callout_reset(&sc->wb_stat_timer, hz, wb_tick, sc);
}

/*
 * Set media options.
 */
static int
wb_ifmedia_upd(struct ifnet *ifp)
{
        struct wb_softc *sc = ifp->if_softc;

        if (ifp->if_flags & IFF_UP)
                wb_init(sc);

        return(0);
}

/*
 * Report current media status.
 */
static void
wb_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
{
        struct wb_softc *sc = ifp->if_softc;
        struct mii_data *mii = device_get_softc(sc->wb_miibus);

        mii_pollstat(mii);
        ifmr->ifm_active = mii->mii_media_active;
        ifmr->ifm_status = mii->mii_media_status;
}

static int
wb_ioctl(struct ifnet *ifp, u_long command, caddr_t data, struct ucred *cr)
{
        struct wb_softc *sc = ifp->if_softc;
        struct mii_data *mii;
        struct ifreq *ifr = (struct ifreq *) data;
        int error = 0;

        crit_enter();

        switch(command) {
        case SIOCSIFFLAGS:
                if (ifp->if_flags & IFF_UP)
                        wb_init(sc);
                else if (ifp->if_flags & IFF_RUNNING)
                        wb_stop(sc);
                error = 0;
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                wb_setmulti(sc);
                error = 0;
                break;
        case SIOCGIFMEDIA:
        case SIOCSIFMEDIA:
                mii = device_get_softc(sc->wb_miibus);
                error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, command);
                break;
        default:
                error = ether_ioctl(ifp, command, data);
                break;
        }

        crit_exit();

        return(error);
}

static void
wb_watchdog(struct ifnet *ifp)
{
        struct wb_softc *sc = ifp->if_softc;

        ifp->if_oerrors++;
        if_printf(ifp, "watchdog timeout\n");
#ifdef foo
        if ((wb_phy_readreg(sc, PHY_BMSR) & PHY_BMSR_LINKSTAT) == 0)
                if_printf(ifp, "no carrier - transceiver cable problem?\n");
#endif
        wb_stop(sc);
        wb_reset(sc);
        wb_init(sc);

        if (!ifq_is_empty(&ifp->if_snd))
                wb_start(ifp);
}

/*
 * Stop the adapter and free any mbufs allocated to the
 * RX and TX lists.
 */
static void
wb_stop(struct wb_softc *sc)
{
        struct ifnet *ifp = &sc->arpcom.ac_if;
        int i;

        ifp->if_timer = 0;

        callout_stop(&sc->wb_stat_timer);

        WB_CLRBIT(sc, WB_NETCFG, (WB_NETCFG_RX_ON | WB_NETCFG_TX_ON));
        CSR_WRITE_4(sc, WB_IMR, 0x00000000);
        CSR_WRITE_4(sc, WB_TXADDR, 0x00000000);
        CSR_WRITE_4(sc, WB_RXADDR, 0x00000000);

        /*
         * Free data in the RX lists.
         */
        for (i = 0; i < WB_RX_LIST_CNT; i++) {
                if (sc->wb_cdata.wb_rx_chain[i].wb_mbuf != NULL) {
                        m_freem(sc->wb_cdata.wb_rx_chain[i].wb_mbuf);
                        sc->wb_cdata.wb_rx_chain[i].wb_mbuf = NULL;
                }
        }
        bzero(&sc->wb_ldata->wb_rx_list, sizeof(sc->wb_ldata->wb_rx_list));

        /*
         * Free the TX list buffers.
         */
        for (i = 0; i < WB_TX_LIST_CNT; i++) {
                if (sc->wb_cdata.wb_tx_chain[i].wb_mbuf != NULL) {
                        m_freem(sc->wb_cdata.wb_tx_chain[i].wb_mbuf);
                        sc->wb_cdata.wb_tx_chain[i].wb_mbuf = NULL;
                }
        }

        bzero(&sc->wb_ldata->wb_tx_list, sizeof(sc->wb_ldata->wb_tx_list));

        ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
}

/*
 * Stop all chip I/O so that the kernel's probe routines don't
 * get confused by errant DMAs when rebooting.
 */
static void
wb_shutdown(device_t dev)
{
        struct wb_softc *sc = device_get_softc(dev);

        wb_stop(sc);
}