/*      $OpenBSD: if_cas.c,v 1.56 2024/05/24 06:02:53 jsg Exp $ */

/*
 *
 * Copyright (C) 2007 Mark Kettenis.
 * Copyright (C) 2001 Eduardo Horvath.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR  ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR  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.
 *
 */

/*
 * Driver for Sun Cassini ethernet controllers.
 *
 * There are basically two variants of this chip: Cassini and
 * Cassini+.  We can distinguish between the two by revision: 0x10 and
 * up are Cassini+.  The most important difference is that Cassini+
 * has a second RX descriptor ring.  Cassini+ will not work without
 * configuring that second ring.  However, since we don't use it we
 * don't actually fill the descriptors, and only hand off the first
 * four to the chip.
 */

#include "bpfilter.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/timeout.h>
#include <sys/mbuf.h>
#include <sys/syslog.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/device.h>
#include <sys/atomic.h>

#include <net/if.h>
#include <net/if_media.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>

#if NBPFILTER > 0
#include <net/bpf.h>
#endif

#include <machine/bus.h>
#include <machine/intr.h>

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

#include <dev/pci/if_casreg.h>
#include <dev/pci/if_casvar.h>

#include <dev/pci/pcivar.h>
#include <dev/pci/pcireg.h>
#include <dev/pci/pcidevs.h>

#ifdef __sparc64__
#include <dev/ofw/openfirm.h>
#endif

#define TRIES   10000

struct cfdriver cas_cd = {
        NULL, "cas", DV_IFNET
};

int     cas_match(struct device *, void *, void *);
void    cas_attach(struct device *, struct device *, void *);
int     cas_pci_enaddr(struct cas_softc *, struct pci_attach_args *);

const struct cfattach cas_ca = {
        sizeof(struct cas_softc), cas_match, cas_attach
};

void            cas_config(struct cas_softc *);
void            cas_start(struct ifnet *);
void            cas_stop(struct ifnet *, int);
int             cas_ioctl(struct ifnet *, u_long, caddr_t);
void            cas_tick(void *);
void            cas_watchdog(struct ifnet *);
int             cas_init(struct ifnet *);
void            cas_init_regs(struct cas_softc *);
int             cas_ringsize(int);
int             cas_cringsize(int);
int             cas_meminit(struct cas_softc *);
void            cas_mifinit(struct cas_softc *);
int             cas_bitwait(struct cas_softc *, bus_space_handle_t, int,
                    u_int32_t, u_int32_t);
void            cas_reset(struct cas_softc *);
int             cas_reset_rx(struct cas_softc *);
int             cas_reset_tx(struct cas_softc *);
int             cas_disable_rx(struct cas_softc *);
int             cas_disable_tx(struct cas_softc *);
void            cas_rxdrain(struct cas_softc *);
int             cas_add_rxbuf(struct cas_softc *, int idx);
void            cas_iff(struct cas_softc *);
int             cas_encap(struct cas_softc *, struct mbuf *, int *);

/* MII methods & callbacks */
int             cas_mii_readreg(struct device *, int, int);
void            cas_mii_writereg(struct device *, int, int, int);
void            cas_mii_statchg(struct device *);
int             cas_pcs_readreg(struct device *, int, int);
void            cas_pcs_writereg(struct device *, int, int, int);

int             cas_mediachange(struct ifnet *);
void            cas_mediastatus(struct ifnet *, struct ifmediareq *);

int             cas_eint(struct cas_softc *, u_int);
int             cas_rint(struct cas_softc *);
int             cas_tint(struct cas_softc *, u_int32_t);
int             cas_pint(struct cas_softc *);
int             cas_intr(void *);

#ifdef CAS_DEBUG
#define DPRINTF(sc, x)  if ((sc)->sc_arpcom.ac_if.if_flags & IFF_DEBUG) \
                                printf x
#else
#define DPRINTF(sc, x)  /* nothing */
#endif

const struct pci_matchid cas_pci_devices[] = {
        { PCI_VENDOR_SUN, PCI_PRODUCT_SUN_CASSINI },
        { PCI_VENDOR_NS, PCI_PRODUCT_NS_SATURN }
};

int
cas_match(struct device *parent, void *cf, void *aux)
{
        return (pci_matchbyid((struct pci_attach_args *)aux, cas_pci_devices,
            nitems(cas_pci_devices)));
}

#define PROMHDR_PTR_DATA        0x18
#define PROMDATA_PTR_VPD        0x08
#define PROMDATA_DATA2          0x0a

static const u_int8_t cas_promhdr[] = { 0x55, 0xaa };
static const u_int8_t cas_promdat_sun[] = {
        'P', 'C', 'I', 'R',
        PCI_VENDOR_SUN & 0xff, PCI_VENDOR_SUN >> 8,
        PCI_PRODUCT_SUN_CASSINI & 0xff, PCI_PRODUCT_SUN_CASSINI >> 8
};
static const u_int8_t cas_promdat_ns[] = {
        'P', 'C', 'I', 'R',
        PCI_VENDOR_NS & 0xff, PCI_VENDOR_NS >> 8,
        PCI_PRODUCT_NS_SATURN & 0xff, PCI_PRODUCT_NS_SATURN >> 8
};

static const u_int8_t cas_promdat2[] = {
        0x18, 0x00,                     /* structure length */
        0x00,                           /* structure revision */
        0x00,                           /* interface revision */
        PCI_SUBCLASS_NETWORK_ETHERNET,  /* subclass code */
        PCI_CLASS_NETWORK               /* class code */
};

int
cas_pci_enaddr(struct cas_softc *sc, struct pci_attach_args *pa)
{
        struct pci_vpd_largeres *res;
        struct pci_vpd *vpd;
        bus_space_handle_t romh;
        bus_space_tag_t romt;
        bus_size_t romsize = 0;
        u_int8_t buf[32], *desc;
        pcireg_t address;
        int dataoff, vpdoff, len;
        int rv = -1;

        if (pci_mapreg_map(pa, PCI_ROM_REG, PCI_MAPREG_TYPE_MEM, 0,
            &romt, &romh, 0, &romsize, 0))
                return (-1);

        address = pci_conf_read(pa->pa_pc, pa->pa_tag, PCI_ROM_REG);
        address |= PCI_ROM_ENABLE;
        pci_conf_write(pa->pa_pc, pa->pa_tag, PCI_ROM_REG, address);

        bus_space_read_region_1(romt, romh, 0, buf, sizeof(buf));
        if (bcmp(buf, cas_promhdr, sizeof(cas_promhdr)))
                goto fail;

        dataoff = buf[PROMHDR_PTR_DATA] | (buf[PROMHDR_PTR_DATA + 1] << 8);
        if (dataoff < 0x1c)
                goto fail;

        bus_space_read_region_1(romt, romh, dataoff, buf, sizeof(buf));
        if ((bcmp(buf, cas_promdat_sun, sizeof(cas_promdat_sun)) &&
            bcmp(buf, cas_promdat_ns, sizeof(cas_promdat_ns))) ||
            bcmp(buf + PROMDATA_DATA2, cas_promdat2, sizeof(cas_promdat2)))
                goto fail;

        vpdoff = buf[PROMDATA_PTR_VPD] | (buf[PROMDATA_PTR_VPD + 1] << 8);
        if (vpdoff < 0x1c)
                goto fail;

next:
        bus_space_read_region_1(romt, romh, vpdoff, buf, sizeof(buf));
        if (!PCI_VPDRES_ISLARGE(buf[0]))
                goto fail;

        res = (struct pci_vpd_largeres *)buf;
        vpdoff += sizeof(*res);

        len = ((res->vpdres_len_msb << 8) + res->vpdres_len_lsb);
        switch(PCI_VPDRES_LARGE_NAME(res->vpdres_byte0)) {
        case PCI_VPDRES_TYPE_IDENTIFIER_STRING:
                /* Skip identifier string. */
                vpdoff += len;
                goto next;

        case PCI_VPDRES_TYPE_VPD:
                while (len > 0) {
                        bus_space_read_region_1(romt, romh, vpdoff,
                             buf, sizeof(buf));

                        vpd = (struct pci_vpd *)buf;
                        vpdoff += sizeof(*vpd) + vpd->vpd_len;
                        len -= sizeof(*vpd) + vpd->vpd_len;

                        /*
                         * We're looking for an "Enhanced" VPD...
                         */
                        if (vpd->vpd_key0 != 'Z')
                                continue;

                        desc = buf + sizeof(*vpd);

                        /* 
                         * ...which is an instance property...
                         */
                        if (desc[0] != 'I')
                                continue;
                        desc += 3;

                        /* 
                         * ...that's a byte array with the proper
                         * length for a MAC address...
                         */
                        if (desc[0] != 'B' || desc[1] != ETHER_ADDR_LEN)
                                continue;
                        desc += 2;

                        /*
                         * ...named "local-mac-address".
                         */
                        if (strcmp(desc, "local-mac-address") != 0)
                                continue;
                        desc += strlen("local-mac-address") + 1;
                                        
                        bcopy(desc, sc->sc_arpcom.ac_enaddr, ETHER_ADDR_LEN);
                        sc->sc_arpcom.ac_enaddr[5] += pa->pa_device;
                        rv = 0;
                }
                break;

        default:
                goto fail;
        }

 fail:
        if (romsize != 0)
                bus_space_unmap(romt, romh, romsize);

        address = pci_conf_read(pa->pa_pc, pa->pa_tag, PCI_ROM_REG);
        address &= ~PCI_ROM_ENABLE;
        pci_conf_write(pa->pa_pc, pa->pa_tag, PCI_ROM_REG, address);

        return (rv);
}

void
cas_attach(struct device *parent, struct device *self, void *aux)
{
        struct pci_attach_args *pa = aux;
        struct cas_softc *sc = (void *)self;
        pci_intr_handle_t ih;
#ifdef __sparc64__
        /* XXX the following declarations should be elsewhere */
        extern void myetheraddr(u_char *);
#endif
        const char *intrstr = NULL;
        bus_size_t size;
        int gotenaddr = 0;

        sc->sc_rev = PCI_REVISION(pa->pa_class);
        sc->sc_dmatag = pa->pa_dmat;

#define PCI_CAS_BASEADDR        0x10
        if (pci_mapreg_map(pa, PCI_CAS_BASEADDR, PCI_MAPREG_TYPE_MEM, 0,
            &sc->sc_memt, &sc->sc_memh, NULL, &size, 0) != 0) {
                printf(": can't map registers\n");
                return;
        }

        if (cas_pci_enaddr(sc, pa) == 0)
                gotenaddr = 1;

#ifdef __sparc64__
        if (!gotenaddr) {
                if (OF_getprop(PCITAG_NODE(pa->pa_tag), "local-mac-address",
                    sc->sc_arpcom.ac_enaddr, ETHER_ADDR_LEN) <= 0)
                        myetheraddr(sc->sc_arpcom.ac_enaddr);
                gotenaddr = 1;
        }
#endif
#ifdef __powerpc__
        if (!gotenaddr) {
                pci_ether_hw_addr(pa->pa_pc, sc->sc_arpcom.ac_enaddr);
                gotenaddr = 1;
        }
#endif

        sc->sc_burst = 16;      /* XXX */

        if (pci_intr_map(pa, &ih) != 0) {
                printf(": couldn't map interrupt\n");
                bus_space_unmap(sc->sc_memt, sc->sc_memh, size);
                return;
        }
        intrstr = pci_intr_string(pa->pa_pc, ih);
        sc->sc_ih = pci_intr_establish(pa->pa_pc,
            ih, IPL_NET | IPL_MPSAFE, cas_intr, sc, self->dv_xname);
        if (sc->sc_ih == NULL) {
                printf(": couldn't establish interrupt");
                if (intrstr != NULL)
                        printf(" at %s", intrstr);
                printf("\n");
                bus_space_unmap(sc->sc_memt, sc->sc_memh, size);
                return;
        }

        printf(": %s", intrstr);

        /*
         * call the main configure
         */
        cas_config(sc);
}

/*
 * cas_config:
 *
 *      Attach a Cassini interface to the system.
 */
void
cas_config(struct cas_softc *sc)
{
        struct ifnet *ifp = &sc->sc_arpcom.ac_if;
        struct mii_data *mii = &sc->sc_mii;
        struct mii_softc *child;
        int i, error;

        /* Make sure the chip is stopped. */
        ifp->if_softc = sc;
        cas_reset(sc);

        /*
         * Allocate the control data structures, and create and load the
         * DMA map for it.
         */
        if ((error = bus_dmamem_alloc(sc->sc_dmatag,
            sizeof(struct cas_control_data), CAS_PAGE_SIZE, 0, &sc->sc_cdseg,
            1, &sc->sc_cdnseg, BUS_DMA_ZERO)) != 0) {
                printf("\n%s: unable to allocate control data, error = %d\n",
                    sc->sc_dev.dv_xname, error);
                goto fail_0;
        }

        /* XXX should map this in with correct endianness */
        if ((error = bus_dmamem_map(sc->sc_dmatag, &sc->sc_cdseg, sc->sc_cdnseg,
            sizeof(struct cas_control_data), (caddr_t *)&sc->sc_control_data,
            BUS_DMA_COHERENT)) != 0) {
                printf("\n%s: unable to map control data, error = %d\n",
                    sc->sc_dev.dv_xname, error);
                goto fail_1;
        }

        if ((error = bus_dmamap_create(sc->sc_dmatag,
            sizeof(struct cas_control_data), 1,
            sizeof(struct cas_control_data), 0, 0, &sc->sc_cddmamap)) != 0) {
                printf("\n%s: unable to create control data DMA map, "
                    "error = %d\n", sc->sc_dev.dv_xname, error);
                goto fail_2;
        }

        if ((error = bus_dmamap_load(sc->sc_dmatag, sc->sc_cddmamap,
            sc->sc_control_data, sizeof(struct cas_control_data), NULL,
            0)) != 0) {
                printf("\n%s: unable to load control data DMA map, error = %d\n",
                    sc->sc_dev.dv_xname, error);
                goto fail_3;
        }

        /*
         * Create the receive buffer DMA maps.
         */
        for (i = 0; i < CAS_NRXDESC; i++) {
                bus_dma_segment_t seg;
                caddr_t kva;
                int rseg;

                if ((error = bus_dmamem_alloc(sc->sc_dmatag, CAS_PAGE_SIZE,
                    CAS_PAGE_SIZE, 0, &seg, 1, &rseg, BUS_DMA_NOWAIT)) != 0) {
                        printf("\n%s: unable to alloc rx DMA mem %d, "
                            "error = %d\n", sc->sc_dev.dv_xname, i, error);
                        goto fail_5;
                }
                sc->sc_rxsoft[i].rxs_dmaseg = seg;

                if ((error = bus_dmamem_map(sc->sc_dmatag, &seg, rseg,
                    CAS_PAGE_SIZE, &kva, BUS_DMA_NOWAIT)) != 0) {
                        printf("\n%s: unable to alloc rx DMA mem %d, "
                            "error = %d\n", sc->sc_dev.dv_xname, i, error);
                        goto fail_5;
                }
                sc->sc_rxsoft[i].rxs_kva = kva;

                if ((error = bus_dmamap_create(sc->sc_dmatag, CAS_PAGE_SIZE, 1,
                    CAS_PAGE_SIZE, 0, 0, &sc->sc_rxsoft[i].rxs_dmamap)) != 0) {
                        printf("\n%s: unable to create rx DMA map %d, "
                            "error = %d\n", sc->sc_dev.dv_xname, i, error);
                        goto fail_5;
                }

                if ((error = bus_dmamap_load(sc->sc_dmatag,
                   sc->sc_rxsoft[i].rxs_dmamap, kva, CAS_PAGE_SIZE, NULL,
                   BUS_DMA_NOWAIT)) != 0) {
                        printf("\n%s: unable to load rx DMA map %d, "
                            "error = %d\n", sc->sc_dev.dv_xname, i, error);
                        goto fail_5;
                }
        }

        /*
         * Create the transmit buffer DMA maps.
         */
        for (i = 0; i < CAS_NTXDESC; i++) {
                if ((error = bus_dmamap_create(sc->sc_dmatag, MCLBYTES,
                    CAS_NTXSEGS, MCLBYTES, 0, BUS_DMA_NOWAIT,
                    &sc->sc_txd[i].sd_map)) != 0) {
                        printf("\n%s: unable to create tx DMA map %d, "
                            "error = %d\n", sc->sc_dev.dv_xname, i, error);
                        goto fail_6;
                }
                sc->sc_txd[i].sd_mbuf = NULL;
        }

        /*
         * From this point forward, the attachment cannot fail.  A failure
         * before this point releases all resources that may have been
         * allocated.
         */

        /* Announce ourselves. */
        printf(", address %s\n", ether_sprintf(sc->sc_arpcom.ac_enaddr));

        /* Get RX FIFO size */
        sc->sc_rxfifosize = 16 * 1024;

        /* Initialize ifnet structure. */
        strlcpy(ifp->if_xname, sc->sc_dev.dv_xname, sizeof ifp->if_xname);
        ifp->if_softc = sc;
        ifp->if_flags =
            IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
        ifp->if_start = cas_start;
        ifp->if_ioctl = cas_ioctl;
        ifp->if_watchdog = cas_watchdog;
        ifq_init_maxlen(&ifp->if_snd, CAS_NTXDESC - 1);

        ifp->if_capabilities = IFCAP_VLAN_MTU;

        /* Initialize ifmedia structures and MII info */
        mii->mii_ifp = ifp;
        mii->mii_readreg = cas_mii_readreg;
        mii->mii_writereg = cas_mii_writereg;
        mii->mii_statchg = cas_mii_statchg;

        ifmedia_init(&mii->mii_media, 0, cas_mediachange, cas_mediastatus);

        bus_space_write_4(sc->sc_memt, sc->sc_memh, CAS_MII_DATAPATH_MODE, 0);

        cas_mifinit(sc);

        if (sc->sc_mif_config & CAS_MIF_CONFIG_MDI1) {
                sc->sc_mif_config |= CAS_MIF_CONFIG_PHY_SEL;
                bus_space_write_4(sc->sc_memt, sc->sc_memh,
                    CAS_MIF_CONFIG, sc->sc_mif_config);
        }

        mii_attach(&sc->sc_dev, mii, 0xffffffff, MII_PHY_ANY,
            MII_OFFSET_ANY, 0);

        child = LIST_FIRST(&mii->mii_phys);
        if (child == NULL &&
            sc->sc_mif_config & (CAS_MIF_CONFIG_MDI0|CAS_MIF_CONFIG_MDI1)) {
                /* 
                 * Try the external PCS SERDES if we didn't find any
                 * MII devices.
                 */
                bus_space_write_4(sc->sc_memt, sc->sc_memh,
                    CAS_MII_DATAPATH_MODE, CAS_MII_DATAPATH_SERDES);

                bus_space_write_4(sc->sc_memt, sc->sc_memh,
                     CAS_MII_CONFIG, CAS_MII_CONFIG_ENABLE);

                mii->mii_readreg = cas_pcs_readreg;
                mii->mii_writereg = cas_pcs_writereg;

                mii_attach(&sc->sc_dev, mii, 0xffffffff, MII_PHY_ANY,
                    MII_OFFSET_ANY, MIIF_NOISOLATE);
        }

        child = LIST_FIRST(&mii->mii_phys);
        if (child == NULL) {
                /* No PHY attached */
                ifmedia_add(&sc->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
                ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_MANUAL);
        } else {
                /*
                 * Walk along the list of attached MII devices and
                 * establish an `MII instance' to `phy number'
                 * mapping. We'll use this mapping in media change
                 * requests to determine which phy to use to program
                 * the MIF configuration register.
                 */
                for (; child != NULL; child = LIST_NEXT(child, mii_list)) {
                        /*
                         * Note: we support just two PHYs: the built-in
                         * internal device and an external on the MII
                         * connector.
                         */
                        if (child->mii_phy > 1 || child->mii_inst > 1) {
                                printf("%s: cannot accommodate MII device %s"
                                       " at phy %d, instance %lld\n",
                                       sc->sc_dev.dv_xname,
                                       child->mii_dev.dv_xname,
                                       child->mii_phy, child->mii_inst);
                                continue;
                        }

                        sc->sc_phys[child->mii_inst] = child->mii_phy;
                }

                /*
                 * XXX - we can really do the following ONLY if the
                 * phy indeed has the auto negotiation capability!!
                 */
                ifmedia_set(&sc->sc_media, IFM_ETHER|IFM_AUTO);
        }

        /* Attach the interface. */
        if_attach(ifp);
        ether_ifattach(ifp);

        timeout_set(&sc->sc_tick_ch, cas_tick, sc);
        return;

        /*
         * Free any resources we've allocated during the failed attach
         * attempt.  Do this in reverse order and fall through.
         */
 fail_6:
        for (i = 0; i < CAS_NTXDESC; i++) {
                if (sc->sc_txd[i].sd_map != NULL)
                        bus_dmamap_destroy(sc->sc_dmatag,
                            sc->sc_txd[i].sd_map);
        }
 fail_5:
        for (i = 0; i < CAS_NRXDESC; i++) {
                if (sc->sc_rxsoft[i].rxs_dmamap != NULL)
                        bus_dmamap_destroy(sc->sc_dmatag,
                            sc->sc_rxsoft[i].rxs_dmamap);
        }
        bus_dmamap_unload(sc->sc_dmatag, sc->sc_cddmamap);
 fail_3:
        bus_dmamap_destroy(sc->sc_dmatag, sc->sc_cddmamap);
 fail_2:
        bus_dmamem_unmap(sc->sc_dmatag, (caddr_t)sc->sc_control_data,
            sizeof(struct cas_control_data));
 fail_1:
        bus_dmamem_free(sc->sc_dmatag, &sc->sc_cdseg, sc->sc_cdnseg);
 fail_0:
        return;
}


void
cas_tick(void *arg)
{
        struct cas_softc *sc = arg;
        struct ifnet *ifp = &sc->sc_arpcom.ac_if;
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t mac = sc->sc_memh;
        int s;
        u_int32_t v;

        /* unload collisions counters */
        v = bus_space_read_4(t, mac, CAS_MAC_EXCESS_COLL_CNT) +
            bus_space_read_4(t, mac, CAS_MAC_LATE_COLL_CNT);
        ifp->if_collisions += v +
            bus_space_read_4(t, mac, CAS_MAC_NORM_COLL_CNT) +
            bus_space_read_4(t, mac, CAS_MAC_FIRST_COLL_CNT);
        ifp->if_oerrors += v;

        /* read error counters */
        ifp->if_ierrors +=
            bus_space_read_4(t, mac, CAS_MAC_RX_LEN_ERR_CNT) +
            bus_space_read_4(t, mac, CAS_MAC_RX_ALIGN_ERR) +
            bus_space_read_4(t, mac, CAS_MAC_RX_CRC_ERR_CNT) +
            bus_space_read_4(t, mac, CAS_MAC_RX_CODE_VIOL);

        /* clear the hardware counters */
        bus_space_write_4(t, mac, CAS_MAC_NORM_COLL_CNT, 0);
        bus_space_write_4(t, mac, CAS_MAC_FIRST_COLL_CNT, 0);
        bus_space_write_4(t, mac, CAS_MAC_EXCESS_COLL_CNT, 0);
        bus_space_write_4(t, mac, CAS_MAC_LATE_COLL_CNT, 0);
        bus_space_write_4(t, mac, CAS_MAC_RX_LEN_ERR_CNT, 0);
        bus_space_write_4(t, mac, CAS_MAC_RX_ALIGN_ERR, 0);
        bus_space_write_4(t, mac, CAS_MAC_RX_CRC_ERR_CNT, 0);
        bus_space_write_4(t, mac, CAS_MAC_RX_CODE_VIOL, 0);

        s = splnet();
        mii_tick(&sc->sc_mii);
        splx(s);

        timeout_add_sec(&sc->sc_tick_ch, 1);
}

int
cas_bitwait(struct cas_softc *sc, bus_space_handle_t h, int r,
    u_int32_t clr, u_int32_t set)
{
        int i;
        u_int32_t reg;

        for (i = TRIES; i--; DELAY(100)) {
                reg = bus_space_read_4(sc->sc_memt, h, r);
                if ((reg & clr) == 0 && (reg & set) == set)
                        return (1);
        }

        return (0);
}

void
cas_reset(struct cas_softc *sc)
{
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;
        int s;

        s = splnet();
        DPRINTF(sc, ("%s: cas_reset\n", sc->sc_dev.dv_xname));
        cas_reset_rx(sc);
        cas_reset_tx(sc);

        /* Do a full reset */
        bus_space_write_4(t, h, CAS_RESET,
            CAS_RESET_RX | CAS_RESET_TX | CAS_RESET_BLOCK_PCS);
        if (!cas_bitwait(sc, h, CAS_RESET, CAS_RESET_RX | CAS_RESET_TX, 0))
                printf("%s: cannot reset device\n", sc->sc_dev.dv_xname);
        splx(s);
}


/*
 * cas_rxdrain:
 *
 *      Drain the receive queue.
 */
void
cas_rxdrain(struct cas_softc *sc)
{
        /* Nothing to do yet. */
}

/*
 * Reset the whole thing.
 */
void
cas_stop(struct ifnet *ifp, int disable)
{
        struct cas_softc *sc = (struct cas_softc *)ifp->if_softc;
        struct cas_sxd *sd;
        u_int32_t i;

        DPRINTF(sc, ("%s: cas_stop\n", sc->sc_dev.dv_xname));

        timeout_del(&sc->sc_tick_ch);

        /*
         * Mark the interface down and cancel the watchdog timer.
         */
        ifp->if_flags &= ~IFF_RUNNING;
        ifq_clr_oactive(&ifp->if_snd);
        ifp->if_timer = 0;

        mii_down(&sc->sc_mii);

        cas_reset_rx(sc);
        cas_reset_tx(sc);

        intr_barrier(sc->sc_ih);
        KASSERT((ifp->if_flags & IFF_RUNNING) == 0);

        /*
         * Release any queued transmit buffers.
         */
        for (i = 0; i < CAS_NTXDESC; i++) {
                sd = &sc->sc_txd[i];
                if (sd->sd_mbuf != NULL) {
                        bus_dmamap_sync(sc->sc_dmatag, sd->sd_map, 0,
                            sd->sd_map->dm_mapsize, BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(sc->sc_dmatag, sd->sd_map);
                        m_freem(sd->sd_mbuf);
                        sd->sd_mbuf = NULL;
                }
        }
        sc->sc_tx_cnt = sc->sc_tx_prod = sc->sc_tx_cons = 0;

        if (disable)
                cas_rxdrain(sc);
}


/*
 * Reset the receiver
 */
int
cas_reset_rx(struct cas_softc *sc)
{
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;

        /*
         * Resetting while DMA is in progress can cause a bus hang, so we
         * disable DMA first.
         */
        cas_disable_rx(sc);
        bus_space_write_4(t, h, CAS_RX_CONFIG, 0);
        /* Wait till it finishes */
        if (!cas_bitwait(sc, h, CAS_RX_CONFIG, 1, 0))
                printf("%s: cannot disable rx dma\n", sc->sc_dev.dv_xname);
        /* Wait 5ms extra. */
        delay(5000);

        /* Finally, reset the ERX */
        bus_space_write_4(t, h, CAS_RESET, CAS_RESET_RX);
        /* Wait till it finishes */
        if (!cas_bitwait(sc, h, CAS_RESET, CAS_RESET_RX, 0)) {
                printf("%s: cannot reset receiver\n", sc->sc_dev.dv_xname);
                return (1);
        }
        return (0);
}


/*
 * Reset the transmitter
 */
int
cas_reset_tx(struct cas_softc *sc)
{
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;

        /*
         * Resetting while DMA is in progress can cause a bus hang, so we
         * disable DMA first.
         */
        cas_disable_tx(sc);
        bus_space_write_4(t, h, CAS_TX_CONFIG, 0);
        /* Wait till it finishes */
        if (!cas_bitwait(sc, h, CAS_TX_CONFIG, 1, 0))
                printf("%s: cannot disable tx dma\n", sc->sc_dev.dv_xname);
        /* Wait 5ms extra. */
        delay(5000);

        /* Finally, reset the ETX */
        bus_space_write_4(t, h, CAS_RESET, CAS_RESET_TX);
        /* Wait till it finishes */
        if (!cas_bitwait(sc, h, CAS_RESET, CAS_RESET_TX, 0)) {
                printf("%s: cannot reset transmitter\n",
                        sc->sc_dev.dv_xname);
                return (1);
        }
        return (0);
}

/*
 * disable receiver.
 */
int
cas_disable_rx(struct cas_softc *sc)
{
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;
        u_int32_t cfg;

        /* Flip the enable bit */
        cfg = bus_space_read_4(t, h, CAS_MAC_RX_CONFIG);
        cfg &= ~CAS_MAC_RX_ENABLE;
        bus_space_write_4(t, h, CAS_MAC_RX_CONFIG, cfg);

        /* Wait for it to finish */
        return (cas_bitwait(sc, h, CAS_MAC_RX_CONFIG, CAS_MAC_RX_ENABLE, 0));
}

/*
 * disable transmitter.
 */
int
cas_disable_tx(struct cas_softc *sc)
{
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;
        u_int32_t cfg;

        /* Flip the enable bit */
        cfg = bus_space_read_4(t, h, CAS_MAC_TX_CONFIG);
        cfg &= ~CAS_MAC_TX_ENABLE;
        bus_space_write_4(t, h, CAS_MAC_TX_CONFIG, cfg);

        /* Wait for it to finish */
        return (cas_bitwait(sc, h, CAS_MAC_TX_CONFIG, CAS_MAC_TX_ENABLE, 0));
}

/*
 * Initialize interface.
 */
int
cas_meminit(struct cas_softc *sc)
{
        struct cas_rxsoft *rxs;
        int i, error;

        rxs = (void *)&error;

        /*
         * Initialize the transmit descriptor ring.
         */
        for (i = 0; i < CAS_NTXDESC; i++) {
                sc->sc_txdescs[i].cd_flags = 0;
                sc->sc_txdescs[i].cd_addr = 0;
        }
        CAS_CDTXSYNC(sc, 0, CAS_NTXDESC,
            BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);

        /*
         * Initialize the receive descriptor and receive job
         * descriptor rings.
         */
        for (i = 0; i < CAS_NRXDESC; i++)
                CAS_INIT_RXDESC(sc, i, i);
        sc->sc_rxdptr = 0;
        sc->sc_rxptr = 0;

        /*
         * Initialize the receive completion ring.
         */
        for (i = 0; i < CAS_NRXCOMP; i++) {
                sc->sc_rxcomps[i].cc_word[0] = 0;
                sc->sc_rxcomps[i].cc_word[1] = 0;
                sc->sc_rxcomps[i].cc_word[2] = 0;
                sc->sc_rxcomps[i].cc_word[3] = CAS_DMA_WRITE(CAS_RC3_OWN);
                CAS_CDRXCSYNC(sc, i,
                    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
        }

        return (0);
}

int
cas_ringsize(int sz)
{
        switch (sz) {
        case 32:
                return CAS_RING_SZ_32;
        case 64:
                return CAS_RING_SZ_64;
        case 128:
                return CAS_RING_SZ_128;
        case 256:
                return CAS_RING_SZ_256;
        case 512:
                return CAS_RING_SZ_512;
        case 1024:
                return CAS_RING_SZ_1024;
        case 2048:
                return CAS_RING_SZ_2048;
        case 4096:
                return CAS_RING_SZ_4096;
        case 8192:
                return CAS_RING_SZ_8192;
        default:
                printf("cas: invalid Receive Descriptor ring size %d\n", sz);
                return CAS_RING_SZ_32;
        }
}

int
cas_cringsize(int sz)
{
        int i;

        for (i = 0; i < 9; i++)
                if (sz == (128 << i))
                        return i;

        printf("cas: invalid completion ring size %d\n", sz);
        return 128;
}

/*
 * Initialization of interface; set up initialization block
 * and transmit/receive descriptor rings.
 */
int
cas_init(struct ifnet *ifp)
{
        struct cas_softc *sc = (struct cas_softc *)ifp->if_softc;
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;
        int s;
        u_int max_frame_size;
        u_int32_t v;

        s = splnet();

        DPRINTF(sc, ("%s: cas_init: calling stop\n", sc->sc_dev.dv_xname));
        /*
         * Initialization sequence. The numbered steps below correspond
         * to the sequence outlined in section 6.3.5.1 in the Ethernet
         * Channel Engine manual (part of the PCIO manual).
         * See also the STP2002-STQ document from Sun Microsystems.
         */

        /* step 1 & 2. Reset the Ethernet Channel */
        cas_stop(ifp, 0);
        cas_reset(sc);
        DPRINTF(sc, ("%s: cas_init: restarting\n", sc->sc_dev.dv_xname));

        /* Re-initialize the MIF */
        cas_mifinit(sc);

        /* step 3. Setup data structures in host memory */
        cas_meminit(sc);

        /* step 4. TX MAC registers & counters */
        cas_init_regs(sc);
        max_frame_size = ETHER_MAX_LEN + ETHER_VLAN_ENCAP_LEN;
        v = (max_frame_size) | (0x2000 << 16) /* Burst size */;
        bus_space_write_4(t, h, CAS_MAC_MAC_MAX_FRAME, v);

        /* step 5. RX MAC registers & counters */
        cas_iff(sc);

        /* step 6 & 7. Program Descriptor Ring Base Addresses */
        KASSERT((CAS_CDTXADDR(sc, 0) & 0x1fff) == 0);
        bus_space_write_4(t, h, CAS_TX_RING_PTR_HI,
            (((uint64_t)CAS_CDTXADDR(sc,0)) >> 32));
        bus_space_write_4(t, h, CAS_TX_RING_PTR_LO, CAS_CDTXADDR(sc, 0));

        KASSERT((CAS_CDRXADDR(sc, 0) & 0x1fff) == 0);
        bus_space_write_4(t, h, CAS_RX_DRING_PTR_HI,
            (((uint64_t)CAS_CDRXADDR(sc,0)) >> 32));
        bus_space_write_4(t, h, CAS_RX_DRING_PTR_LO, CAS_CDRXADDR(sc, 0));

        KASSERT((CAS_CDRXCADDR(sc, 0) & 0x1fff) == 0);
        bus_space_write_4(t, h, CAS_RX_CRING_PTR_HI,
            (((uint64_t)CAS_CDRXCADDR(sc,0)) >> 32));
        bus_space_write_4(t, h, CAS_RX_CRING_PTR_LO, CAS_CDRXCADDR(sc, 0));

        if (CAS_PLUS(sc)) {
                KASSERT((CAS_CDRXADDR2(sc, 0) & 0x1fff) == 0);
                bus_space_write_4(t, h, CAS_RX_DRING_PTR_HI2,
                    (((uint64_t)CAS_CDRXADDR2(sc,0)) >> 32));
                bus_space_write_4(t, h, CAS_RX_DRING_PTR_LO2,
                    CAS_CDRXADDR2(sc, 0));
        }

        /* step 8. Global Configuration & Interrupt Mask */
        bus_space_write_4(t, h, CAS_INTMASK,
                      ~(CAS_INTR_TX_INTME|CAS_INTR_TX_EMPTY|
                        CAS_INTR_TX_TAG_ERR|
                        CAS_INTR_RX_DONE|CAS_INTR_RX_NOBUF|
                        CAS_INTR_RX_TAG_ERR|
                        CAS_INTR_RX_COMP_FULL|CAS_INTR_PCS|
                        CAS_INTR_MAC_CONTROL|CAS_INTR_MIF|
                        CAS_INTR_BERR));
        bus_space_write_4(t, h, CAS_MAC_RX_MASK,
            CAS_MAC_RX_DONE|CAS_MAC_RX_FRAME_CNT);
        bus_space_write_4(t, h, CAS_MAC_TX_MASK, CAS_MAC_TX_XMIT_DONE);
        bus_space_write_4(t, h, CAS_MAC_CONTROL_MASK, 0); /* XXXX */

        /* step 9. ETX Configuration: use mostly default values */

        /* Enable DMA */
        v = cas_ringsize(CAS_NTXDESC /*XXX*/) << 10;
        bus_space_write_4(t, h, CAS_TX_CONFIG,
            v|CAS_TX_CONFIG_TXDMA_EN|(1<<24)|(1<<29));
        bus_space_write_4(t, h, CAS_TX_KICK, 0);

        /* step 10. ERX Configuration */

        /* Encode Receive Descriptor ring size */
        v = cas_ringsize(CAS_NRXDESC) << CAS_RX_CONFIG_RXDRNG_SZ_SHIFT;
        if (CAS_PLUS(sc))
                v |= cas_ringsize(32) << CAS_RX_CONFIG_RXDRNG2_SZ_SHIFT;

        /* Encode Receive Completion ring size */
        v |= cas_cringsize(CAS_NRXCOMP) << CAS_RX_CONFIG_RXCRNG_SZ_SHIFT;

        /* Enable DMA */
        bus_space_write_4(t, h, CAS_RX_CONFIG,
            v|(2<<CAS_RX_CONFIG_FBOFF_SHFT)|CAS_RX_CONFIG_RXDMA_EN);

        /*
         * The following value is for an OFF Threshold of about 3/4 full
         * and an ON Threshold of 1/4 full.
         */
        bus_space_write_4(t, h, CAS_RX_PAUSE_THRESH,
            (3 * sc->sc_rxfifosize / 256) |
            ((sc->sc_rxfifosize / 256) << 12));
        bus_space_write_4(t, h, CAS_RX_BLANKING, (6 << 12) | 6);

        /* step 11. Configure Media */
        mii_mediachg(&sc->sc_mii);

        /* step 12. RX_MAC Configuration Register */
        v = bus_space_read_4(t, h, CAS_MAC_RX_CONFIG);
        v |= CAS_MAC_RX_ENABLE | CAS_MAC_RX_STRIP_CRC;
        bus_space_write_4(t, h, CAS_MAC_RX_CONFIG, v);

        /* step 14. Issue Transmit Pending command */

        /* step 15.  Give the receiver a swift kick */
        bus_space_write_4(t, h, CAS_RX_KICK, CAS_NRXDESC-4);
        if (CAS_PLUS(sc))
                bus_space_write_4(t, h, CAS_RX_KICK2, 4);

        /* Start the one second timer. */
        timeout_add_sec(&sc->sc_tick_ch, 1);

        ifp->if_flags |= IFF_RUNNING;
        ifq_clr_oactive(&ifp->if_snd);
        ifp->if_timer = 0;
        splx(s);

        return (0);
}

void
cas_init_regs(struct cas_softc *sc)
{
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;
        u_int32_t v, r;

        /* These regs are not cleared on reset */
        sc->sc_inited = 0;
        if (!sc->sc_inited) {
                /* Load recommended values  */
                bus_space_write_4(t, h, CAS_MAC_IPG0, 0x00);
                bus_space_write_4(t, h, CAS_MAC_IPG1, 0x08);
                bus_space_write_4(t, h, CAS_MAC_IPG2, 0x04);

                bus_space_write_4(t, h, CAS_MAC_MAC_MIN_FRAME, ETHER_MIN_LEN);
                /* Max frame and max burst size */
                v = ETHER_MAX_LEN | (0x2000 << 16) /* Burst size */;
                bus_space_write_4(t, h, CAS_MAC_MAC_MAX_FRAME, v);

                bus_space_write_4(t, h, CAS_MAC_PREAMBLE_LEN, 0x07);
                bus_space_write_4(t, h, CAS_MAC_JAM_SIZE, 0x04);
                bus_space_write_4(t, h, CAS_MAC_ATTEMPT_LIMIT, 0x10);
                bus_space_write_4(t, h, CAS_MAC_CONTROL_TYPE, 0x8088);
                bus_space_write_4(t, h, CAS_MAC_RANDOM_SEED,
                    ((sc->sc_arpcom.ac_enaddr[5]<<8)|sc->sc_arpcom.ac_enaddr[4])&0x3ff);

                /* Secondary MAC addresses set to 0:0:0:0:0:0 */
                for (r = CAS_MAC_ADDR3; r < CAS_MAC_ADDR42; r += 4)
                        bus_space_write_4(t, h, r, 0);

                /* MAC control addr set to 0:1:c2:0:1:80 */
                bus_space_write_4(t, h, CAS_MAC_ADDR42, 0x0001);
                bus_space_write_4(t, h, CAS_MAC_ADDR43, 0xc200);
                bus_space_write_4(t, h, CAS_MAC_ADDR44, 0x0180);

                /* MAC filter addr set to 0:0:0:0:0:0 */
                bus_space_write_4(t, h, CAS_MAC_ADDR_FILTER0, 0);
                bus_space_write_4(t, h, CAS_MAC_ADDR_FILTER1, 0);
                bus_space_write_4(t, h, CAS_MAC_ADDR_FILTER2, 0);

                bus_space_write_4(t, h, CAS_MAC_ADR_FLT_MASK1_2, 0);
                bus_space_write_4(t, h, CAS_MAC_ADR_FLT_MASK0, 0);

                /* Hash table initialized to 0 */
                for (r = CAS_MAC_HASH0; r <= CAS_MAC_HASH15; r += 4)
                        bus_space_write_4(t, h, r, 0);

                sc->sc_inited = 1;
        }

        /* Counters need to be zeroed */
        bus_space_write_4(t, h, CAS_MAC_NORM_COLL_CNT, 0);
        bus_space_write_4(t, h, CAS_MAC_FIRST_COLL_CNT, 0);
        bus_space_write_4(t, h, CAS_MAC_EXCESS_COLL_CNT, 0);
        bus_space_write_4(t, h, CAS_MAC_LATE_COLL_CNT, 0);
        bus_space_write_4(t, h, CAS_MAC_DEFER_TMR_CNT, 0);
        bus_space_write_4(t, h, CAS_MAC_PEAK_ATTEMPTS, 0);
        bus_space_write_4(t, h, CAS_MAC_RX_FRAME_COUNT, 0);
        bus_space_write_4(t, h, CAS_MAC_RX_LEN_ERR_CNT, 0);
        bus_space_write_4(t, h, CAS_MAC_RX_ALIGN_ERR, 0);
        bus_space_write_4(t, h, CAS_MAC_RX_CRC_ERR_CNT, 0);
        bus_space_write_4(t, h, CAS_MAC_RX_CODE_VIOL, 0);

        /* Un-pause stuff */
        bus_space_write_4(t, h, CAS_MAC_SEND_PAUSE_CMD, 0);

        /*
         * Set the station address.
         */
        bus_space_write_4(t, h, CAS_MAC_ADDR0, 
                (sc->sc_arpcom.ac_enaddr[4]<<8) | sc->sc_arpcom.ac_enaddr[5]);
        bus_space_write_4(t, h, CAS_MAC_ADDR1, 
                (sc->sc_arpcom.ac_enaddr[2]<<8) | sc->sc_arpcom.ac_enaddr[3]);
        bus_space_write_4(t, h, CAS_MAC_ADDR2, 
                (sc->sc_arpcom.ac_enaddr[0]<<8) | sc->sc_arpcom.ac_enaddr[1]);
}

/*
 * Receive interrupt.
 */
int
cas_rint(struct cas_softc *sc)
{
        struct ifnet *ifp = &sc->sc_arpcom.ac_if;
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;
        struct cas_rxsoft *rxs;
        struct mbuf_list ml = MBUF_LIST_INITIALIZER();
        struct mbuf *m;
        u_int64_t word[4];
        int len, off, idx;
        int i, skip;
        caddr_t cp;

        for (i = sc->sc_rxptr;; i = CAS_NEXTRX(i + skip)) {
                CAS_CDRXCSYNC(sc, i,
                    BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);

                word[0] = CAS_DMA_READ(sc->sc_rxcomps[i].cc_word[0]);
                word[1] = CAS_DMA_READ(sc->sc_rxcomps[i].cc_word[1]);
                word[2] = CAS_DMA_READ(sc->sc_rxcomps[i].cc_word[2]);
                word[3] = CAS_DMA_READ(sc->sc_rxcomps[i].cc_word[3]);

                /* Stop if the hardware still owns the descriptor. */
                if ((word[0] & CAS_RC0_TYPE) == 0 || word[3] & CAS_RC3_OWN)
                        break;

                len = CAS_RC1_HDR_LEN(word[1]);
                if (len > 0) {
                        off = CAS_RC1_HDR_OFF(word[1]);
                        idx = CAS_RC1_HDR_IDX(word[1]);
                        rxs = &sc->sc_rxsoft[idx];

                        DPRINTF(sc, ("hdr at idx %d, off %d, len %d\n",
                            idx, off, len));

                        bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
                            rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);

                        cp = rxs->rxs_kva + off * 256 + ETHER_ALIGN;
                        m = m_devget(cp, len, ETHER_ALIGN);

                        if (word[0] & CAS_RC0_RELEASE_HDR)
                                cas_add_rxbuf(sc, idx);

                        if (m != NULL) {
                                ml_enqueue(&ml, m);
                        } else
                                ifp->if_ierrors++;
                }

                len = CAS_RC0_DATA_LEN(word[0]);
                if (len > 0) {
                        off = CAS_RC0_DATA_OFF(word[0]);
                        idx = CAS_RC0_DATA_IDX(word[0]);
                        rxs = &sc->sc_rxsoft[idx];

                        DPRINTF(sc, ("data at idx %d, off %d, len %d\n",
                            idx, off, len));

                        bus_dmamap_sync(sc->sc_dmatag, rxs->rxs_dmamap, 0,
                            rxs->rxs_dmamap->dm_mapsize, BUS_DMASYNC_POSTREAD);

                        /* XXX We should not be copying the packet here. */
                        cp = rxs->rxs_kva + off + ETHER_ALIGN;
                        m = m_devget(cp, len, ETHER_ALIGN);

                        if (word[0] & CAS_RC0_RELEASE_DATA)
                                cas_add_rxbuf(sc, idx);

                        if (m != NULL) {
                                ml_enqueue(&ml, m);
                        } else
                                ifp->if_ierrors++;
                }

                if (word[0] & CAS_RC0_SPLIT)
                        printf("split packet\n");

                skip = CAS_RC0_SKIP(word[0]);
        }

        while (sc->sc_rxptr != i) {
                sc->sc_rxcomps[sc->sc_rxptr].cc_word[0] = 0;
                sc->sc_rxcomps[sc->sc_rxptr].cc_word[1] = 0;
                sc->sc_rxcomps[sc->sc_rxptr].cc_word[2] = 0;
                sc->sc_rxcomps[sc->sc_rxptr].cc_word[3] =
                    CAS_DMA_WRITE(CAS_RC3_OWN);
                CAS_CDRXCSYNC(sc, sc->sc_rxptr,
                    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);

                sc->sc_rxptr = CAS_NEXTRX(sc->sc_rxptr);
        }

        bus_space_write_4(t, h, CAS_RX_COMP_TAIL, sc->sc_rxptr);

        DPRINTF(sc, ("cas_rint: done sc->rxptr %d, complete %d\n",
                sc->sc_rxptr, bus_space_read_4(t, h, CAS_RX_COMPLETION)));

        if_input(ifp, &ml);

        return (1);
}

/*
 * cas_add_rxbuf:
 *
 *      Add a receive buffer to the indicated descriptor.
 */
int
cas_add_rxbuf(struct cas_softc *sc, int idx)
{
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;

        CAS_INIT_RXDESC(sc, sc->sc_rxdptr, idx);

        if ((sc->sc_rxdptr % 4) == 0)
                bus_space_write_4(t, h, CAS_RX_KICK, sc->sc_rxdptr);

        if (++sc->sc_rxdptr == CAS_NRXDESC)
                sc->sc_rxdptr = 0;

        return (0);
}

int
cas_eint(struct cas_softc *sc, u_int status)
{
        if ((status & CAS_INTR_MIF) != 0) {
#ifdef CAS_DEBUG
                printf("%s: link status changed\n", sc->sc_dev.dv_xname);
#endif
                return (1);
        }

        printf("%s: status=%b\n", sc->sc_dev.dv_xname, status, CAS_INTR_BITS);
        return (1);
}

int
cas_pint(struct cas_softc *sc)
{
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t seb = sc->sc_memh;
        u_int32_t status;

        status = bus_space_read_4(t, seb, CAS_MII_INTERRUP_STATUS);
        status |= bus_space_read_4(t, seb, CAS_MII_INTERRUP_STATUS);
#ifdef CAS_DEBUG
        if (status)
                printf("%s: link status changed\n", sc->sc_dev.dv_xname);
#endif
        return (1);
}

int
cas_intr(void *v)
{
        struct cas_softc *sc = (struct cas_softc *)v;
        struct ifnet *ifp = &sc->sc_arpcom.ac_if;
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t seb = sc->sc_memh;
        u_int32_t status;
        int r = 0;

        status = bus_space_read_4(t, seb, CAS_STATUS);
        DPRINTF(sc, ("%s: cas_intr: cplt %xstatus %b\n",
                sc->sc_dev.dv_xname, (status>>19), status, CAS_INTR_BITS));

        if ((status & CAS_INTR_PCS) != 0)
                r |= cas_pint(sc);

        if ((status & (CAS_INTR_TX_TAG_ERR | CAS_INTR_RX_TAG_ERR |
            CAS_INTR_RX_COMP_FULL | CAS_INTR_BERR)) != 0)
                r |= cas_eint(sc, status);

        if ((status & (CAS_INTR_TX_EMPTY | CAS_INTR_TX_INTME)) != 0)
                r |= cas_tint(sc, status);

        if ((status & (CAS_INTR_RX_DONE | CAS_INTR_RX_NOBUF)) != 0)
                r |= cas_rint(sc);

        /* We should eventually do more than just print out error stats. */
        if (status & CAS_INTR_TX_MAC) {
                int txstat = bus_space_read_4(t, seb, CAS_MAC_TX_STATUS);
#ifdef CAS_DEBUG
                if (txstat & ~CAS_MAC_TX_XMIT_DONE)
                        printf("%s: MAC tx fault, status %x\n",
                            sc->sc_dev.dv_xname, txstat);
#endif
                if (txstat & (CAS_MAC_TX_UNDERRUN | CAS_MAC_TX_PKT_TOO_LONG)) {
                        KERNEL_LOCK();
                        cas_init(ifp);
                        KERNEL_UNLOCK();
                }
        }
        if (status & CAS_INTR_RX_MAC) {
                int rxstat = bus_space_read_4(t, seb, CAS_MAC_RX_STATUS);
#ifdef CAS_DEBUG
                if (rxstat & ~CAS_MAC_RX_DONE)
                        printf("%s: MAC rx fault, status %x\n",
                            sc->sc_dev.dv_xname, rxstat);
#endif
                /*
                 * On some chip revisions CAS_MAC_RX_OVERFLOW happen often
                 * due to a silicon bug so handle them silently.
                 */
                if (rxstat & CAS_MAC_RX_OVERFLOW) {
                        KERNEL_LOCK();
                        ifp->if_ierrors++;
                        cas_init(ifp);
                        KERNEL_UNLOCK();
                }
#ifdef CAS_DEBUG
                else if (rxstat & ~(CAS_MAC_RX_DONE | CAS_MAC_RX_FRAME_CNT))
                        printf("%s: MAC rx fault, status %x\n",
                            sc->sc_dev.dv_xname, rxstat);
#endif
        }
        return (r);
}


void
cas_watchdog(struct ifnet *ifp)
{
        struct cas_softc *sc = ifp->if_softc;

        DPRINTF(sc, ("cas_watchdog: CAS_RX_CONFIG %x CAS_MAC_RX_STATUS %x "
                "CAS_MAC_RX_CONFIG %x\n",
                bus_space_read_4(sc->sc_memt, sc->sc_memh, CAS_RX_CONFIG),
                bus_space_read_4(sc->sc_memt, sc->sc_memh, CAS_MAC_RX_STATUS),
                bus_space_read_4(sc->sc_memt, sc->sc_memh, CAS_MAC_RX_CONFIG)));

        log(LOG_ERR, "%s: device timeout\n", sc->sc_dev.dv_xname);
        ++ifp->if_oerrors;

        /* Try to get more packets going. */
        cas_init(ifp);
}

/*
 * Initialize the MII Management Interface
 */
void
cas_mifinit(struct cas_softc *sc)
{
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t mif = sc->sc_memh;

        /* Configure the MIF in frame mode */
        sc->sc_mif_config = bus_space_read_4(t, mif, CAS_MIF_CONFIG);
        sc->sc_mif_config &= ~CAS_MIF_CONFIG_BB_ENA;
        bus_space_write_4(t, mif, CAS_MIF_CONFIG, sc->sc_mif_config);
}

/*
 * MII interface
 *
 * The Cassini MII interface supports at least three different operating modes:
 *
 * Bitbang mode is implemented using data, clock and output enable registers.
 *
 * Frame mode is implemented by loading a complete frame into the frame
 * register and polling the valid bit for completion.
 *
 * Polling mode uses the frame register but completion is indicated by
 * an interrupt.
 *
 */
int
cas_mii_readreg(struct device *self, int phy, int reg)
{
        struct cas_softc *sc = (void *)self;
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t mif = sc->sc_memh;
        int n;
        u_int32_t v;

#ifdef CAS_DEBUG
        if (sc->sc_debug)
                printf("cas_mii_readreg: phy %d reg %d\n", phy, reg);
#endif

        /* Construct the frame command */
        v = (reg << CAS_MIF_REG_SHIFT)  | (phy << CAS_MIF_PHY_SHIFT) |
                CAS_MIF_FRAME_READ;

        bus_space_write_4(t, mif, CAS_MIF_FRAME, v);
        for (n = 0; n < 100; n++) {
                DELAY(1);
                v = bus_space_read_4(t, mif, CAS_MIF_FRAME);
                if (v & CAS_MIF_FRAME_TA0)
                        return (v & CAS_MIF_FRAME_DATA);
        }

        printf("%s: mii_read timeout\n", sc->sc_dev.dv_xname);
        return (0);
}

void
cas_mii_writereg(struct device *self, int phy, int reg, int val)
{
        struct cas_softc *sc = (void *)self;
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t mif = sc->sc_memh;
        int n;
        u_int32_t v;

#ifdef CAS_DEBUG
        if (sc->sc_debug)
                printf("cas_mii_writereg: phy %d reg %d val %x\n",
                        phy, reg, val);
#endif

        /* Construct the frame command */
        v = CAS_MIF_FRAME_WRITE                 |
            (phy << CAS_MIF_PHY_SHIFT)          |
            (reg << CAS_MIF_REG_SHIFT)          |
            (val & CAS_MIF_FRAME_DATA);

        bus_space_write_4(t, mif, CAS_MIF_FRAME, v);
        for (n = 0; n < 100; n++) {
                DELAY(1);
                v = bus_space_read_4(t, mif, CAS_MIF_FRAME);
                if (v & CAS_MIF_FRAME_TA0)
                        return;
        }

        printf("%s: mii_write timeout\n", sc->sc_dev.dv_xname);
}

void
cas_mii_statchg(struct device *dev)
{
        struct cas_softc *sc = (void *)dev;
#ifdef CAS_DEBUG
        uint64_t instance = IFM_INST(sc->sc_mii.mii_media.ifm_cur->ifm_media);
#endif
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t mac = sc->sc_memh;
        u_int32_t v;

#ifdef CAS_DEBUG
        if (sc->sc_debug)
                printf("cas_mii_statchg: status change: phy = %d\n",
                    sc->sc_phys[instance]);
#endif

        /* Set tx full duplex options */
        bus_space_write_4(t, mac, CAS_MAC_TX_CONFIG, 0);
        delay(10000); /* reg must be cleared and delay before changing. */
        v = CAS_MAC_TX_ENA_IPG0|CAS_MAC_TX_NGU|CAS_MAC_TX_NGU_LIMIT|
                CAS_MAC_TX_ENABLE;
        if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_FDX) != 0) {
                v |= CAS_MAC_TX_IGN_CARRIER|CAS_MAC_TX_IGN_COLLIS;
        }
        bus_space_write_4(t, mac, CAS_MAC_TX_CONFIG, v);

        /* XIF Configuration */
        v = CAS_MAC_XIF_TX_MII_ENA;
        v |= CAS_MAC_XIF_LINK_LED;

        /* MII needs echo disable if half duplex. */
        if ((IFM_OPTIONS(sc->sc_mii.mii_media_active) & IFM_FDX) != 0)
                /* turn on full duplex LED */
                v |= CAS_MAC_XIF_FDPLX_LED;
        else
                /* half duplex -- disable echo */
                v |= CAS_MAC_XIF_ECHO_DISABL;

        switch (IFM_SUBTYPE(sc->sc_mii.mii_media_active)) {
        case IFM_1000_T:  /* Gigabit using GMII interface */
        case IFM_1000_SX:
                v |= CAS_MAC_XIF_GMII_MODE;
                break;
        default:
                v &= ~CAS_MAC_XIF_GMII_MODE;
        }
        bus_space_write_4(t, mac, CAS_MAC_XIF_CONFIG, v);
}

int
cas_pcs_readreg(struct device *self, int phy, int reg)
{
        struct cas_softc *sc = (void *)self;
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t pcs = sc->sc_memh;

#ifdef CAS_DEBUG
        if (sc->sc_debug)
                printf("cas_pcs_readreg: phy %d reg %d\n", phy, reg);
#endif

        if (phy != CAS_PHYAD_EXTERNAL)
                return (0);

        switch (reg) {
        case MII_BMCR:
                reg = CAS_MII_CONTROL;
                break;
        case MII_BMSR:
                reg = CAS_MII_STATUS;
                break;
        case MII_ANAR:
                reg = CAS_MII_ANAR;
                break;
        case MII_ANLPAR:
                reg = CAS_MII_ANLPAR;
                break;
        case MII_EXTSR:
                return (EXTSR_1000XFDX|EXTSR_1000XHDX);
        default:
                return (0);
        }

        return bus_space_read_4(t, pcs, reg);
}

void
cas_pcs_writereg(struct device *self, int phy, int reg, int val)
{
        struct cas_softc *sc = (void *)self;
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t pcs = sc->sc_memh;
        int reset = 0;

#ifdef CAS_DEBUG
        if (sc->sc_debug)
                printf("cas_pcs_writereg: phy %d reg %d val %x\n",
                        phy, reg, val);
#endif

        if (phy != CAS_PHYAD_EXTERNAL)
                return;

        if (reg == MII_ANAR)
                bus_space_write_4(t, pcs, CAS_MII_CONFIG, 0);

        switch (reg) {
        case MII_BMCR:
                reset = (val & CAS_MII_CONTROL_RESET);
                reg = CAS_MII_CONTROL;
                break;
        case MII_BMSR:
                reg = CAS_MII_STATUS;
                break;
        case MII_ANAR:
                reg = CAS_MII_ANAR;
                break;
        case MII_ANLPAR:
                reg = CAS_MII_ANLPAR;
                break;
        default:
                return;
        }

        bus_space_write_4(t, pcs, reg, val);

        if (reset)
                cas_bitwait(sc, pcs, CAS_MII_CONTROL, CAS_MII_CONTROL_RESET, 0);

        if (reg == CAS_MII_ANAR || reset)
                bus_space_write_4(t, pcs, CAS_MII_CONFIG,
                    CAS_MII_CONFIG_ENABLE);
}

int
cas_mediachange(struct ifnet *ifp)
{
        struct cas_softc *sc = ifp->if_softc;
        struct mii_data *mii = &sc->sc_mii;

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

        return (mii_mediachg(&sc->sc_mii));
}

void
cas_mediastatus(struct ifnet *ifp, struct ifmediareq *ifmr)
{
        struct cas_softc *sc = ifp->if_softc;

        mii_pollstat(&sc->sc_mii);
        ifmr->ifm_active = sc->sc_mii.mii_media_active;
        ifmr->ifm_status = sc->sc_mii.mii_media_status;
}

/*
 * Process an ioctl request.
 */
int
cas_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
        struct cas_softc *sc = ifp->if_softc;
        struct ifreq *ifr = (struct ifreq *)data;
        int s, error = 0;

        s = splnet();

        switch (cmd) {
        case SIOCSIFADDR:
                ifp->if_flags |= IFF_UP;
                if ((ifp->if_flags & IFF_RUNNING) == 0)
                        cas_init(ifp);
                break;

        case SIOCSIFFLAGS:
                if (ifp->if_flags & IFF_UP) {
                        if (ifp->if_flags & IFF_RUNNING)
                                error = ENETRESET;
                        else
                                cas_init(ifp);
                } else {
                        if (ifp->if_flags & IFF_RUNNING)
                                cas_stop(ifp, 1);
                }
#ifdef CAS_DEBUG
                sc->sc_debug = (ifp->if_flags & IFF_DEBUG) != 0 ? 1 : 0;
#endif
                break;

        case SIOCGIFMEDIA:
        case SIOCSIFMEDIA:
                error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
                break;

        default:
                error = ether_ioctl(ifp, &sc->sc_arpcom, cmd, data);
        }

        if (error == ENETRESET) {
                if (ifp->if_flags & IFF_RUNNING)
                        cas_iff(sc);
                error = 0;
        }

        splx(s);
        return (error);
}

void
cas_iff(struct cas_softc *sc)
{
        struct ifnet *ifp = &sc->sc_arpcom.ac_if;
        struct arpcom *ac = &sc->sc_arpcom;
        struct ether_multi *enm;
        struct ether_multistep step;
        bus_space_tag_t t = sc->sc_memt;
        bus_space_handle_t h = sc->sc_memh;
        u_int32_t crc, hash[16], rxcfg;
        int i;

        rxcfg = bus_space_read_4(t, h, CAS_MAC_RX_CONFIG);
        rxcfg &= ~(CAS_MAC_RX_HASH_FILTER | CAS_MAC_RX_PROMISCUOUS |
            CAS_MAC_RX_PROMISC_GRP);
        ifp->if_flags &= ~IFF_ALLMULTI;

        if (ifp->if_flags & IFF_PROMISC || ac->ac_multirangecnt > 0) {
                ifp->if_flags |= IFF_ALLMULTI;
                if (ifp->if_flags & IFF_PROMISC)
                        rxcfg |= CAS_MAC_RX_PROMISCUOUS;
                else
                        rxcfg |= CAS_MAC_RX_PROMISC_GRP;
        } else {
                /*
                 * Set up multicast address filter by passing all multicast
                 * addresses through a crc generator, and then using the
                 * high order 8 bits as an index into the 256 bit logical
                 * address filter.  The high order 4 bits selects the word,
                 * while the other 4 bits select the bit within the word
                 * (where bit 0 is the MSB).
                 */

                rxcfg |= CAS_MAC_RX_HASH_FILTER;

                /* Clear hash table */
                for (i = 0; i < 16; i++)
                        hash[i] = 0;

                ETHER_FIRST_MULTI(step, ac, enm);
                while (enm != NULL) {
                        crc = ether_crc32_le(enm->enm_addrlo,
                            ETHER_ADDR_LEN);

                        /* Just want the 8 most significant bits. */
                        crc >>= 24;

                        /* Set the corresponding bit in the filter. */
                        hash[crc >> 4] |= 1 << (15 - (crc & 15));

                        ETHER_NEXT_MULTI(step, enm);
                }

                /* Now load the hash table into the chip (if we are using it) */
                for (i = 0; i < 16; i++) {
                        bus_space_write_4(t, h,
                            CAS_MAC_HASH0 + i * (CAS_MAC_HASH1 - CAS_MAC_HASH0),
                            hash[i]);
                }
        }

        bus_space_write_4(t, h, CAS_MAC_RX_CONFIG, rxcfg);
}

int
cas_encap(struct cas_softc *sc, struct mbuf *m, int *used)
{
        u_int64_t flags;
        u_int32_t first, cur, frag, i;
        bus_dmamap_t map;

        cur = frag = (sc->sc_tx_prod + *used) % CAS_NTXDESC;
        map = sc->sc_txd[cur].sd_map;

        switch (bus_dmamap_load_mbuf(sc->sc_dmatag, map, m, BUS_DMA_NOWAIT)) {
        case 0:
                break;
        case EFBIG:
                if (m_defrag(m, M_DONTWAIT) == 0 &&
                    bus_dmamap_load_mbuf(sc->sc_dmatag, map, m,
                    BUS_DMA_NOWAIT) == 0)
                        break;
                /* FALLTHROUGH */
        default:
                return (ENOBUFS);
        }

        bus_dmamap_sync(sc->sc_dmatag, map, 0, map->dm_mapsize,
            BUS_DMASYNC_PREWRITE);

        first = cur;
        for (i = 0; i < map->dm_nsegs; i++) {
                sc->sc_txdescs[frag].cd_addr =
                    CAS_DMA_WRITE(map->dm_segs[i].ds_addr);
                flags = (map->dm_segs[i].ds_len & CAS_TD_BUFSIZE) |
                    (i == 0 ? CAS_TD_START_OF_PACKET : 0) |
                    ((i == (map->dm_nsegs - 1)) ? CAS_TD_END_OF_PACKET : 0);
                sc->sc_txdescs[frag].cd_flags = CAS_DMA_WRITE(flags);
                bus_dmamap_sync(sc->sc_dmatag, sc->sc_cddmamap,
                    CAS_CDTXOFF(frag), sizeof(struct cas_desc),
                    BUS_DMASYNC_PREWRITE);
                cur = frag;
                if (++frag == CAS_NTXDESC)
                        frag = 0;
        }

        sc->sc_txd[first].sd_map = sc->sc_txd[cur].sd_map;
        sc->sc_txd[cur].sd_map = map;
        sc->sc_txd[cur].sd_mbuf = m;

        bus_space_write_4(sc->sc_memt, sc->sc_memh, CAS_TX_KICK, frag);

        *used += map->dm_nsegs;

        /* sync descriptors */

        return (0);
}

/*
 * Transmit interrupt.
 */
int
cas_tint(struct cas_softc *sc, u_int32_t status)
{
        struct ifnet *ifp = &sc->sc_arpcom.ac_if;
        struct cas_sxd *sd;
        u_int32_t cons, comp;
        int freed, used;

        comp = bus_space_read_4(sc->sc_memt, sc->sc_memh, CAS_TX_COMPLETION);
        cons = sc->sc_tx_cons;
        freed = 0;
        while (cons != comp) {
                sd = &sc->sc_txd[cons];
                if (sd->sd_mbuf != NULL) {
                        bus_dmamap_sync(sc->sc_dmatag, sd->sd_map, 0,
                            sd->sd_map->dm_mapsize, BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(sc->sc_dmatag, sd->sd_map);
                        m_freem(sd->sd_mbuf);
                        sd->sd_mbuf = NULL;
                }
                freed++;
                if (++cons == CAS_NTXDESC)
                        cons = 0;
        }
        sc->sc_tx_cons = cons;

        used = atomic_sub_int_nv(&sc->sc_tx_cnt, freed);
        if (used < CAS_NTXDESC - 2)
                ifq_clr_oactive(&ifp->if_snd);
        if (used == 0)
                ifp->if_timer = 0;

        if (!ifq_empty(&ifp->if_snd)) {
                KERNEL_LOCK();
                cas_start(ifp);
                KERNEL_UNLOCK();
        }

        return (1);
}

void
cas_start(struct ifnet *ifp)
{
        struct cas_softc *sc = ifp->if_softc;
        struct mbuf *m = NULL;
        int used;

        if (!(ifp->if_flags & IFF_RUNNING) || ifq_is_oactive(&ifp->if_snd))
                return;

        used = 0;
        while (1) {
                if ((sc->sc_tx_cnt + used + CAS_NTXSEGS) >= (CAS_NTXDESC - 2)) {
                        ifq_set_oactive(&ifp->if_snd);
                        break;
                }

                m = ifq_dequeue(&ifp->if_snd);
                if (m == NULL)
                        break;

                if (cas_encap(sc, m, &used)) {
                        m_freem(m);
                        continue;
                }

#if NBPFILTER > 0
                if (ifp->if_bpf)
                        bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT);
#endif
        }

        if (used != 0) {
                ifp->if_timer = 5;
                sc->sc_tx_prod = (sc->sc_tx_prod + used) % CAS_NTXDESC;
                atomic_add_int(&sc->sc_tx_cnt, used);
        }
}