freebsd-dev/sys/pci/if_tx.c

/*	$OpenBSD: if_tx.c,v 1.9.2.1 2000/02/21 22:29:13 niklas Exp $	*/
/* $FreeBSD$ */

/*-
 * Copyright (c) 1997 Semen Ustimenko (semen@iclub.nsu.ru)
 * 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 AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * EtherPower II 10/100  Fast Ethernet (tx0)
 * (aka SMC9432TX based on SMC83c170 EPIC chip)
 * 
 * Thanks are going to Steve Bauer and Jason Wright.
 *
 * todo:
 *	Implement FULL IFF_MULTICAST support.
 *	
 */

/* We should define compile time options before if_txvar.h included */
#define	EARLY_RX	1
/*#define	EPIC_DEBUG	1*/

#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>

#if defined(__FreeBSD__)
#define NBPFILTER	1

#include <net/if.h>
#include <net/if_arp.h>
#include <net/ethernet.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_memio.h>
#include <machine/bus_pio.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/bus.h>
#include <sys/rman.h>

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

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

#include "miibus_if.h"

#include <pci/if_txvar.h>
#else /* __OpenBSD__ */
#include "bpfilter.h"

#include <sys/device.h>

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

#ifdef INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>
#endif

#ifdef IPX
#include <netipx/ipx.h>
#include <netipx/ipx_if.h>
#endif

#ifdef NS
#include <netns/ns.h>
#include <netns/ns_if.h>
#endif

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

#include <vm/vm.h>
#include <vm/pmap.h>

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

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

#include <dev/pci/if_txvar.h>
#endif

MODULE_DEPEND(tx, miibus, 1, 1, 1);

#if defined(__FreeBSD__)
#define EPIC_INTR_RET_TYPE void
#else /* __OpenBSD__ */
#define EPIC_INTR_RET_TYPE int
#endif

static int epic_ifioctl __P((register struct ifnet *, u_long, caddr_t));
static EPIC_INTR_RET_TYPE epic_intr __P((void *));
static int epic_common_attach __P((epic_softc_t *));
static void epic_ifstart __P((struct ifnet *));
static void epic_ifwatchdog __P((struct ifnet *));
static int epic_init __P((epic_softc_t *));
static void epic_stop __P((epic_softc_t *));
static void epic_rx_done __P((epic_softc_t *));
static void epic_tx_done __P((epic_softc_t *));
static int epic_init_rings __P((epic_softc_t *));
static void epic_free_rings __P((epic_softc_t *));
static void epic_stop_activity __P((epic_softc_t *));
static void epic_start_activity __P((epic_softc_t *));
static void epic_set_rx_mode __P((epic_softc_t *));
static void epic_set_tx_mode __P((epic_softc_t *));
static void epic_set_mc_table __P((epic_softc_t *));
static int epic_read_eeprom __P((epic_softc_t *,u_int16_t));
static void epic_output_eepromw __P((epic_softc_t *, u_int16_t));
static u_int16_t epic_input_eepromw __P((epic_softc_t *));
static u_int8_t epic_eeprom_clock __P((epic_softc_t *,u_int8_t));
static void epic_write_eepromreg __P((epic_softc_t *,u_int8_t));
static u_int8_t epic_read_eepromreg __P((epic_softc_t *));

static int epic_read_phy_reg __P((epic_softc_t *, int, int));
static void epic_write_phy_reg __P((epic_softc_t *, int, int, int));

static int epic_miibus_readreg __P((device_t, int, int));
static int epic_miibus_writereg __P((device_t, int, int, int));
static void epic_miibus_statchg __P((device_t));
static void epic_miibus_mediainit __P((device_t));

static int epic_ifmedia_upd __P((struct ifnet *));
static void epic_ifmedia_sts __P((struct ifnet *, struct ifmediareq *));

/* -------------------------------------------------------------------------
   OS-specific part
   ------------------------------------------------------------------------- */

#if defined(__OpenBSD__)
/* -----------------------------OpenBSD------------------------------------- */

int epic_openbsd_probe __P((struct device *,void *,void *));
void epic_openbsd_attach __P((struct device *, struct device *, void *));
void epic_openbsd_shutdown __P((void *));

struct cfattach tx_ca = {
	sizeof(epic_softc_t), epic_openbsd_probe, epic_openbsd_attach 
};
struct cfdriver tx_cd = {
	NULL,"tx",DV_IFNET
};

/* Synopsis: Check if device id corresponds with SMC83C170 id. */
int 
epic_openbsd_probe(
    struct device *parent,
    void *match,
    void *aux )
{
	struct pci_attach_args *pa = aux;
	if( PCI_VENDOR(pa->pa_id) != SMC_VENDORID )
		return 0;

	if( PCI_PRODUCT(pa->pa_id) == SMC_DEVICEID_83C170 )
		return 1;

	return 0;
}

void
epic_openbsd_attach(
    struct device *parent,
    struct device *self,
    void *aux )
{
	epic_softc_t *sc = (epic_softc_t*)self;
	struct pci_attach_args *pa = aux;
	pci_chipset_tag_t pc = pa->pa_pc;
	pci_intr_handle_t ih;
	const char *intrstr = NULL;
	struct ifnet *ifp;
	bus_addr_t iobase;
	bus_size_t iosize; 
	int i;
	u_int32_t command;

	command = pci_conf_read(pc, pa->pa_tag, PCI_COMMAND_STATUS_REG);
	command |= PCI_COMMAND_IO_ENABLE | PCI_COMMAND_MEM_ENABLE |
	    PCI_COMMAND_MASTER_ENABLE;
	pci_conf_write(pc, pa->pa_tag, PCI_COMMAND_STATUS_REG, command);
	command = pci_conf_read(pc, pa->pa_tag, PCI_COMMAND_STATUS_REG);

#ifdef EPIC_USEIOSPACE
	if (!(command & PCI_COMMAND_IO_ENABLE)) {
		printf(": failed to enable I/O ports\n");
		return;
	}
	if( pci_io_find(pc, pa->pa_tag, PCI_BASEIO, &iobase, &iosize)) {
		printf(": can't find i/o space\n");
		return;
	}
	if( bus_space_map(pa->pa_iot, iobase, iosize, 0, &sc->sc_sh)) {
		printf(": can't map i/o space\n");
		return;
	}
	sc->sc_st = pa->pa_iot;
#else
	if (!(command & PCI_COMMAND_MEM_ENABLE)) {
		printf(": failed to enable memory mapping\n");
		return;
	}
	if( pci_mem_find(pc, pa->pa_tag, PCI_BASEMEM, &iobase, &iosize, NULL)) {
		printf(": can't find mem space\n");
		return;
	}
	if( bus_space_map(pa->pa_memt, iobase, iosize, 0, &sc->sc_sh)) {
		printf(": can't map i/o space\n");
		return;
	}
	sc->sc_st = pa->pa_memt;
#endif

	ifp = &sc->sc_if;
	bcopy(sc->dev.dv_xname, ifp->if_xname,IFNAMSIZ);
	ifp->if_softc = sc;
	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
	ifp->if_ioctl = epic_ifioctl;
	ifp->if_start = epic_ifstart;
	ifp->if_watchdog = epic_ifwatchdog;

	/* Do common attach procedure */
	if( epic_common_attach(sc) ) return;

	/* Map interrupt */
	if( pci_intr_map(pc, pa->pa_intrtag, pa->pa_intrpin,
	    pa->pa_intrline, &ih)) {
		printf(": can't map interrupt\n");
		return;
	}
	intrstr = pci_intr_string(pc, ih);
	sc->sc_ih = pci_intr_establish(pc, ih, IPL_NET, epic_intr, sc, 
	    self->dv_xname);

	if( NULL == sc->sc_ih ) {
		printf(": can't establish interrupt");
		if( intrstr )printf(" at %s",intrstr);
		printf("\n");
		return;
	} 
	printf(": %s",intrstr);

	/* Display some info */
	printf(" address %s",ether_sprintf(sc->sc_macaddr));

	/* Init ifmedia interface */
	ifmedia_init(&sc->sc_mii.mii_media, 0,
		epic_ifmedia_upd, epic_ifmedia_sts);
	sc->sc_mii.mii_ifp = ifp;
	sc->sc_mii.mii_readreg = epic_miibus_readreg;
	sc->sc_mii.mii_writereg = epic_miibus_writereg;
	sc->sc_mii.mii_statchg = epic_miibus_statchg;
	mii_phy_probe(self, &sc->sc_mii, 0xffffffff);
	if (LIST_FIRST(&sc->sc_mii.mii_phys) == NULL) {
		ifmedia_add(&sc->sc_mii.mii_media, IFM_ETHER|IFM_NONE,0,NULL);
		ifmedia_set(&sc->sc_mii.mii_media, IFM_ETHER|IFM_NONE);
        } else
		ifmedia_set(&sc->sc_mii.mii_media, IFM_ETHER|IFM_AUTO);

	/* Attach os interface and bpf */
	if_attach(ifp);
	ether_ifattach(ifp);
#if NBPFILTER > 0
	bpfattach(&sc->sc_if.if_bpf, ifp, DLT_EN10MB,
	    sizeof(struct ether_header));
#endif

	/* Set shutdown routine to stop DMA process */ 
	shutdownhook_establish(epic_openbsd_shutdown, sc);
	printf("\n");
}

/* Simple call epic_stop() */
void
epic_openbsd_shutdown(
    void *sc)
{
	epic_stop(sc);
}

#else /* __FreeBSD__ */
/* -----------------------------FreeBSD------------------------------------- */

static int epic_freebsd_probe __P((device_t));
static int epic_freebsd_attach __P((device_t));
static void epic_freebsd_shutdown __P((device_t));
static int epic_freebsd_detach __P((device_t));
static struct epic_type *epic_devtype __P((device_t));

static device_method_t epic_methods[] = {
	/* Device interface */   
	DEVMETHOD(device_probe,		epic_freebsd_probe),
	DEVMETHOD(device_attach,	epic_freebsd_attach),
	DEVMETHOD(device_detach,	epic_freebsd_detach),
	DEVMETHOD(device_shutdown,	epic_freebsd_shutdown),

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

	/* MII interface */
	DEVMETHOD(miibus_readreg,	epic_miibus_readreg),
	DEVMETHOD(miibus_writereg,	epic_miibus_writereg),
	DEVMETHOD(miibus_statchg,	epic_miibus_statchg),
	DEVMETHOD(miibus_mediainit,	epic_miibus_mediainit),

	{ 0, 0 }
};

static driver_t epic_driver = {
        "tx",
        epic_methods,
        sizeof(epic_softc_t)
};

static devclass_t epic_devclass;

DRIVER_MODULE(if_tx, pci, epic_driver, epic_devclass, 0, 0);
DRIVER_MODULE(miibus, tx, miibus_driver, miibus_devclass, 0, 0);

static struct epic_type epic_devs[] = {
	{ SMC_VENDORID, SMC_DEVICEID_83C170,
		"SMC EtherPower II 10/100" },   
	{ 0, 0, NULL }
};

static int
epic_freebsd_probe(dev)
	device_t dev;
{
	struct epic_type *t;

	t = epic_devtype(dev);

	if (t != NULL) {
		device_set_desc(dev, t->name);
		return(0);
	}

	return(ENXIO);
}

static struct epic_type *
epic_devtype(dev)
	device_t dev;
{
	struct epic_type *t;

	t = epic_devs;

	while(t->name != NULL) {
		if ((pci_get_vendor(dev) == t->ven_id) &&
		    (pci_get_device(dev) == t->dev_id)) {
			return(t);
		}
		t++;
	}
	return (NULL);
}

#if defined(EPIC_USEIOSPACE)
#define	EPIC_RES	SYS_RES_IOPORT
#define	EPIC_RID	PCIR_BASEIO
#else
#define	EPIC_RES	SYS_RES_MEMORY
#define	EPIC_RID	PCIR_BASEMEM
#endif

/*
 * Do FreeBSD-specific attach routine, like map registers, alloc softc
 * structure and etc.
 */
static int
epic_freebsd_attach(dev)
	device_t dev;
{
	struct ifnet *ifp;
	epic_softc_t *sc;
	u_int32_t command;
	int unit, error;
	int i, s, rid, tmp;

	s = splimp ();

	sc = device_get_softc(dev);
	unit = device_get_unit(dev);

	/* Preinitialize softc structure */
    	bzero(sc, sizeof(epic_softc_t));		
	sc->unit = unit;
	sc->dev = dev;

	/* Fill ifnet structure */
	ifp = &sc->sc_if;
	ifp->if_unit = unit;
	ifp->if_name = "tx";
	ifp->if_softc = sc;
	ifp->if_flags = IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST;
	ifp->if_ioctl = epic_ifioctl;
	ifp->if_output = ether_output;
	ifp->if_start = epic_ifstart;
	ifp->if_watchdog = epic_ifwatchdog;
	ifp->if_init = (if_init_f_t*)epic_init;
	ifp->if_timer = 0;
	ifp->if_baudrate = 10000000;
	ifp->if_snd.ifq_maxlen = TX_RING_SIZE - 1;

	/* Enable ports, memory and busmastering */
	command = pci_read_config(dev, PCIR_COMMAND, 4);
	command |= PCIM_CMD_PORTEN | PCIM_CMD_MEMEN | PCIM_CMD_BUSMASTEREN;
	pci_write_config(dev, PCIR_COMMAND, command, 4);
	command = pci_read_config(dev, PCIR_COMMAND, 4);

#if defined(EPIC_USEIOSPACE)
	if (!(command & PCIM_CMD_PORTEN)) {
		device_printf(dev, "failed to enable I/O mapping!\n");
		error = ENXIO;
		goto fail;
	}
#else
	if (!(command & PCIM_CMD_MEMEN)) {
		device_printf(dev, "failed to enable memory mapping!\n");
		error = ENXIO;
		goto fail;
	}
#endif

	rid = EPIC_RID;
	sc->res = bus_alloc_resource(dev, EPIC_RES, &rid, 0, ~0, 1,
	    RF_ACTIVE);

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

	sc->sc_st = rman_get_bustag(sc->res);
	sc->sc_sh = rman_get_bushandle(sc->res);

	/* Allocate interrupt */
	rid = 0;
	sc->irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0, ~0, 1,
	    RF_SHAREABLE | RF_ACTIVE);

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

	error = bus_setup_intr(dev, sc->irq, INTR_TYPE_NET,
	    epic_intr, sc, &sc->sc_ih);

	if (error) {
		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq);
		bus_release_resource(dev, EPIC_RES, EPIC_RID, sc->res);
		device_printf(dev, "couldn't set up irq\n");
		goto fail;
	}

	/* Bring the chip out of low-power mode and reset it. */
	CSR_WRITE_4( sc, GENCTL, GENCTL_SOFT_RESET );
	DELAY(500);

	/* Workaround for Application Note 7-15 */
	for (i=0; i<16; i++) CSR_WRITE_4(sc, TEST1, TEST1_CLOCK_TEST);

	/*
	 * Do ifmedia setup.
	 */
	if (mii_phy_probe(dev, &sc->miibus,
	    epic_ifmedia_upd, epic_ifmedia_sts)) {
		device_printf(dev, "MII without any PHY!?\n");
		bus_teardown_intr(dev, sc->irq, sc->sc_ih);
		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq);
		bus_release_resource(dev, EPIC_RES, EPIC_RID, sc->res);
		error = ENXIO;
		goto fail;
	}

	/* Do OS independent part, including chip wakeup and reset */
	if (epic_common_attach(sc)) {
		device_printf(dev, "memory distribution error\n");
		bus_teardown_intr(dev, sc->irq, sc->sc_ih);
		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq);
		bus_release_resource(dev, EPIC_RES, EPIC_RID, sc->res);
		error = ENXIO;
		goto fail;
	}

	/* Display ethernet address ,... */
	device_printf(dev, "address %6D,", sc->sc_macaddr, ":");

	/* board type and ... */
	printf(" type ");
	for(i=0x2c;i<0x32;i++) {
		tmp = epic_read_eeprom( sc, i );
		if( ' ' == (u_int8_t)tmp ) break;
		printf("%c",(u_int8_t)tmp);
		tmp >>= 8;
		if( ' ' == (u_int8_t)tmp ) break;
		printf("%c",(u_int8_t)tmp);
	}
	printf ("\n");

	/* Attach to OS's managers */
	ether_ifattach(ifp, ETHER_BPF_SUPPORTED);
	callout_handle_init(&sc->stat_ch);

fail:
	splx(s);

	return(error);
}

/*
 * Detach driver and free resources
 */
static int
epic_freebsd_detach(dev)
	device_t dev;
{
	struct ifnet *ifp;
	epic_softc_t *sc;
	int s;

	s = splimp();

	sc = device_get_softc(dev);
	ifp = &sc->arpcom.ac_if;

	ether_ifdetach(ifp, ETHER_BPF_SUPPORTED);

	epic_stop(sc);

	bus_generic_detach(dev);
	device_delete_child(dev, sc->miibus);

	bus_teardown_intr(dev, sc->irq, sc->sc_ih);
	bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq);
	bus_release_resource(dev, EPIC_RES, EPIC_RID, sc->res);

	free(sc->pool, M_DEVBUF);

	splx(s);

	return(0);
}

#undef	EPIC_RES
#undef	EPIC_RID

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

	sc = device_get_softc(dev);

	epic_stop(sc);

	return;
}
#endif /* __OpenBSD__ */

/* ------------------------------------------------------------------------
   OS-independing part
   ------------------------------------------------------------------------ */

/*
 * This is if_ioctl handler. 
 */
static int
epic_ifioctl(ifp, command, data)
	struct ifnet *ifp;
	u_long command;
	caddr_t data;
{
	epic_softc_t *sc = ifp->if_softc;
	struct mii_data	*mii;
	struct ifreq *ifr = (struct ifreq *) data;
	int x, error = 0;

	x = splimp();

	switch (command) {
#if defined(__FreeBSD__)
	case SIOCSIFADDR:
	case SIOCGIFADDR:
	case SIOCSIFMTU:
		error = ether_ioctl(ifp, command, data);
		break;
#else /* __OpenBSD__ */
	case SIOCSIFADDR: {
		struct ifaddr *ifa = (struct ifaddr *)data;
		
		ifp->if_flags |= IFF_UP;
		switch(ifa->ifa_addr->sa_family) {
#if INET
		case AF_INET:
			epic_stop(sc);
			epic_init(sc);
			arp_ifinit(&sc->arpcom,ifa);
			break;
#endif
#if NS
		case AF_NS: {
			register struct ns_addr * ina = &IA_SNS(ifa)->sns_addr;

			if( ns_nullhost(*ina) ) 
				ina->x_host = 
				    *(union ns_host *) LLADDR(ifp->if_sadl);
			else
				bcopy(ina->x_host.c_host, LLADDR(ifp->if_sadl),
				    ifp->if_addrlen);

			epic_stop(sc);
			epic_init(sc);
			break;
		}
#endif
		default:
			epic_stop(sc);
			epic_init(sc);		
			break;
		}
	}
#endif /* __FreeBSD__ */

	case SIOCSIFFLAGS:
		/*
		 * If the interface is marked up and stopped, then start it.
		 * If it is marked down and running, then stop it.
		 */
		if (ifp->if_flags & IFF_UP) {
			if ((ifp->if_flags & IFF_RUNNING) == 0) {
				epic_init(sc);
				break;
			}
		} else {
			if (ifp->if_flags & IFF_RUNNING) {
				epic_stop(sc);
				break;
			}
		}

		/* Handle IFF_PROMISC flag */
		epic_stop_activity(sc);	
		epic_set_rx_mode(sc);
		epic_start_activity(sc);	
		break;

	case SIOCADDMULTI:
	case SIOCDELMULTI:
		/* Update out multicast list */
#if defined(__FreeBSD__) && __FreeBSD_version >= 300000
		epic_set_mc_table(sc);
		error = 0;
#else
		error = (command == SIOCADDMULTI) ?
		    ether_addmulti((struct ifreq *)data, &sc->arpcom) :
		    ether_delmulti((struct ifreq *)data, &sc->arpcom);

		if (error == ENETRESET) {
			epic_set_mc_table(sc);
			error = 0;
		}
#endif
		break;

	case SIOCSIFMEDIA:
	case SIOCGIFMEDIA:
		mii = device_get_softc(sc->miibus);
		error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, command);
		break;

	default:
		error = EINVAL;
	}
	splx(x);

	return error;
}

/*
 * OS-independed part of attach process. allocate memory for descriptors
 * and frag lists, wake up chip, read MAC address and PHY identyfier.
 * Return -1 on failure.
 */
static int
epic_common_attach(sc)
	epic_softc_t *sc;
{
	int i;
	caddr_t pool;

	i = sizeof(struct epic_frag_list)*TX_RING_SIZE +
	    sizeof(struct epic_rx_desc)*RX_RING_SIZE + 
	    sizeof(struct epic_tx_desc)*TX_RING_SIZE + PAGE_SIZE,
	sc->pool = (epic_softc_t *) malloc(i, M_DEVBUF, M_NOWAIT | M_ZERO);

	if (sc->pool == NULL) {
		printf(": can't allocate memory for buffers\n");
		return -1;
	}

	/* Align pool on PAGE_SIZE */
	pool = (caddr_t)sc->pool;
	pool = (caddr_t)((u_int32_t)(pool + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1));

	/* Distribute memory */
	sc->tx_flist = (void *)pool;
	pool += sizeof(struct epic_frag_list)*TX_RING_SIZE;
	sc->rx_desc = (void *)pool;
	pool += sizeof(struct epic_rx_desc)*RX_RING_SIZE;
	sc->tx_desc = (void *)pool;

	/* Bring the chip out of low-power mode. */
	CSR_WRITE_4( sc, GENCTL, GENCTL_SOFT_RESET);
	DELAY(500);

	/* Workaround for Application Note 7-15 */
	for (i=0; i<16; i++) CSR_WRITE_4(sc, TEST1, TEST1_CLOCK_TEST);

	/* Read mac address from EEPROM */
	for (i = 0; i < ETHER_ADDR_LEN / sizeof(u_int16_t); i++)
		((u_int16_t *)sc->sc_macaddr)[i] = epic_read_eeprom(sc,i);

	/* Set defaults */
	sc->tx_threshold = TRANSMIT_THRESHOLD;
	sc->txcon = TXCON_DEFAULT;

	return 0;
}

/*
 * This is if_start handler. It takes mbufs from if_snd queue
 * and quque them for transmit, one by one, until TX ring become full
 * or quque become empty.
 */
static void
epic_ifstart(ifp)
	struct ifnet * ifp;
{
	epic_softc_t *sc = ifp->if_softc;
	struct epic_tx_buffer *buf;
	struct epic_tx_desc *desc;
	struct epic_frag_list *flist;
	struct mbuf *m0;
	register struct mbuf *m;
	register int i;

	while( sc->pending_txs < TX_RING_SIZE  ){
		buf = sc->tx_buffer + sc->cur_tx;
		desc = sc->tx_desc + sc->cur_tx;
		flist = sc->tx_flist + sc->cur_tx;

		/* Get next packet to send */
		IF_DEQUEUE( &ifp->if_snd, m0 );

		/* If nothing to send, return */
		if( NULL == m0 ) return;

		/* Fill fragments list */
		for( m=m0, i=0;
		    (NULL != m) && (i < EPIC_MAX_FRAGS);
		    m = m->m_next, i++ ) {
			flist->frag[i].fraglen = m->m_len; 
			flist->frag[i].fragaddr = vtophys( mtod(m, caddr_t) );
		}
		flist->numfrags = i;

		/* If packet was more than EPIC_MAX_FRAGS parts, */
		/* recopy packet to new allocated mbuf cluster */
		if( NULL != m ){
			EPIC_MGETCLUSTER(m);
			if( NULL == m ){
				printf(EPIC_FORMAT ": cannot allocate mbuf cluster\n",EPIC_ARGS(sc));
				m_freem(m0);
				ifp->if_oerrors++;
				continue;
			}

			m_copydata( m0, 0, m0->m_pkthdr.len, mtod(m,caddr_t) );
			flist->frag[0].fraglen = 
			     m->m_pkthdr.len = m->m_len = m0->m_pkthdr.len;
			m->m_pkthdr.rcvif = ifp;

			flist->numfrags = 1;
			flist->frag[0].fragaddr = vtophys( mtod(m, caddr_t) );
			m_freem(m0);
			m0 = m;
		}

		buf->mbuf = m0;
		sc->pending_txs++;
		sc->cur_tx = ( sc->cur_tx + 1 ) & TX_RING_MASK;
		desc->control = 0x01;
		desc->txlength = 
		    max(m0->m_pkthdr.len,ETHER_MIN_LEN-ETHER_CRC_LEN);
		desc->status = 0x8000;
		CSR_WRITE_4( sc, COMMAND, COMMAND_TXQUEUED );

		/* Set watchdog timer */
		ifp->if_timer = 8;

#if NBPFILTER > 0
		if( ifp->if_bpf ) 
			bpf_mtap( EPIC_BPFTAP_ARG(ifp), m0 );
#endif
	}

	ifp->if_flags |= IFF_OACTIVE;

	return;
	
}

/*
 * Synopsis: Finish all received frames.
 */
static void
epic_rx_done(sc)
	epic_softc_t *sc;
{
	u_int16_t len;
	struct epic_rx_buffer *buf;
	struct epic_rx_desc *desc;
	struct mbuf *m;
	struct ether_header *eh;

	while( !(sc->rx_desc[sc->cur_rx].status & 0x8000) ) { 
		buf = sc->rx_buffer + sc->cur_rx;
		desc = sc->rx_desc + sc->cur_rx;

		/* Switch to next descriptor */
		sc->cur_rx = (sc->cur_rx+1) & RX_RING_MASK;

		/* Check for errors, this should happend */
		/* only if SAVE_ERRORED_PACKETS is set, */
		/* normaly rx errors generate RXE interrupt */
		if( !(desc->status & 1) ) {
			dprintf((EPIC_FORMAT ": Rx error status: 0x%x\n",EPIC_ARGS(sc),desc->status));
			sc->sc_if.if_ierrors++;
			desc->status = 0x8000;
			continue;
		}

		/* Save packet length and mbuf contained packet */ 
		len = desc->rxlength - ETHER_CRC_LEN;
		m = buf->mbuf;

		/* Try to get mbuf cluster */
		EPIC_MGETCLUSTER( buf->mbuf );
		if( NULL == buf->mbuf ) { 
			printf(EPIC_FORMAT ": cannot allocate mbuf cluster\n",EPIC_ARGS(sc));
			buf->mbuf = m;
			desc->status = 0x8000;
			sc->sc_if.if_ierrors++;
			continue;
		}

		/* Point to new mbuf, and give descriptor to chip */
		desc->bufaddr = vtophys( mtod( buf->mbuf, caddr_t ) );
		desc->status = 0x8000;
		
		/* First mbuf in packet holds the ethernet and packet headers */
		eh = mtod( m, struct ether_header * );
		m->m_pkthdr.rcvif = &(sc->sc_if);
		m->m_pkthdr.len = m->m_len = len;

#if !defined(__FreeBSD__)
#if NBPFILTER > 0
		/* Give mbuf to BPFILTER */
		if( sc->sc_if.if_bpf ) 
			bpf_mtap( EPIC_BPFTAP_ARG(&sc->sc_if), m );
#endif /* NBPFILTER > 0 */
#endif /* !__FreeBSD__ */

		/* Second mbuf holds packet ifself */
		m->m_pkthdr.len = m->m_len = len - sizeof(struct ether_header);
		m->m_data += sizeof( struct ether_header );

		/* Give mbuf to OS */
		ether_input(&sc->sc_if, eh, m);

		/* Successfuly received frame */
		sc->sc_if.if_ipackets++;
        }

	return;
}

/*
 * Synopsis: Do last phase of transmission. I.e. if desc is 
 * transmitted, decrease pending_txs counter, free mbuf contained
 * packet, switch to next descriptor and repeat until no packets
 * are pending or descriptor is not transmitted yet.
 */
static void
epic_tx_done(sc)
	epic_softc_t *sc;
{
	struct epic_tx_buffer *buf;
	struct epic_tx_desc *desc;
	u_int16_t status;

	while( sc->pending_txs > 0 ){
		buf = sc->tx_buffer + sc->dirty_tx;
		desc = sc->tx_desc + sc->dirty_tx;
		status = desc->status;

		/* If packet is not transmitted, thou followed */
		/* packets are not transmitted too */
		if( status & 0x8000 ) break;

		/* Packet is transmitted. Switch to next and */
		/* free mbuf */
		sc->pending_txs--;
		sc->dirty_tx = (sc->dirty_tx + 1) & TX_RING_MASK;
		m_freem( buf->mbuf );
		buf->mbuf = NULL;

		/* Check for errors and collisions */
		if( status & 0x0001 ) sc->sc_if.if_opackets++;
		else sc->sc_if.if_oerrors++;
		sc->sc_if.if_collisions += (status >> 8) & 0x1F;
#if defined(EPIC_DEBUG)
		if( (status & 0x1001) == 0x1001 ) 
			dprintf((EPIC_FORMAT ": frame not transmitted due collisions\n",EPIC_ARGS(sc)));
#endif
	}

	if( sc->pending_txs < TX_RING_SIZE ) 
		sc->sc_if.if_flags &= ~IFF_OACTIVE;
}

/*
 * Interrupt function
 */
static EPIC_INTR_RET_TYPE
epic_intr(arg)
    void *arg;
{
    epic_softc_t * sc = (epic_softc_t *) arg;
    int status,i=4;
#if defined(__OpenBSD__)
    int claimed = 0;
#endif

    while( i-- && ((status = CSR_READ_4(sc, INTSTAT)) & INTSTAT_INT_ACTV) ){
#if defined(__OpenBSD__)
	claimed = 1;
#endif
	CSR_WRITE_4( sc, INTSTAT, status );

	if( status & (INTSTAT_RQE|INTSTAT_RCC|INTSTAT_OVW) ) {
            epic_rx_done( sc );
            if( status & (INTSTAT_RQE|INTSTAT_OVW) ){
#if defined(EPIC_DEBUG)
                if( status & INTSTAT_OVW ) 
                    printf(EPIC_FORMAT ": RX buffer overflow\n",EPIC_ARGS(sc));
                if( status & INTSTAT_RQE ) 
                    printf(EPIC_FORMAT ": RX FIFO overflow\n",EPIC_ARGS(sc));
#endif
                if( !(CSR_READ_4( sc, COMMAND ) & COMMAND_RXQUEUED) )
                    CSR_WRITE_4( sc, COMMAND, COMMAND_RXQUEUED );
                sc->sc_if.if_ierrors++;
            }
        }

        if( status & (INTSTAT_TXC|INTSTAT_TCC|INTSTAT_TQE) ) {
            epic_tx_done( sc );
	    if(!(sc->sc_if.if_flags & IFF_OACTIVE) &&
		sc->sc_if.if_snd.ifq_head )
		    epic_ifstart( &sc->sc_if );
	}

	/* Check for errors */
	if( status & (INTSTAT_FATAL|INTSTAT_PMA|INTSTAT_PTA|
		      INTSTAT_APE|INTSTAT_DPE|INTSTAT_TXU|INTSTAT_RXE) ){
    	    if( status & (INTSTAT_FATAL|INTSTAT_PMA|INTSTAT_PTA|
			  INTSTAT_APE|INTSTAT_DPE) ){
		printf(EPIC_FORMAT ": PCI fatal error occured (%s%s%s%s)\n",
    		    EPIC_ARGS(sc),
		    (status&INTSTAT_PMA)?"PMA":"",
		    (status&INTSTAT_PTA)?" PTA":"",
		    (status&INTSTAT_APE)?" APE":"",
		    (status&INTSTAT_DPE)?" DPE":""
		);

		epic_stop(sc);
		epic_init(sc);
		
	    	break;
	    }

	    if (status & INTSTAT_RXE) {
		dprintf((EPIC_FORMAT ": CRC/Alignment error\n",EPIC_ARGS(sc)));
		sc->sc_if.if_ierrors++;
	    }

	    /* Tx FIFO underflow. Increase tx threshold, */
	    /* if it grown above 2048, disable EARLY_TX */
	    if (status & INTSTAT_TXU) {
		if( sc->tx_threshold > 0x800 ) {
		    sc->txcon &= ~TXCON_EARLY_TRANSMIT_ENABLE;
    		    dprintf((EPIC_FORMAT ": TX underrun error, early tx disabled\n",EPIC_ARGS(sc)));
		} else {
		    sc->tx_threshold += 0x40;
    		    dprintf((EPIC_FORMAT ": TX underrun error, tx threshold increased to %d\n",EPIC_ARGS(sc),sc->tx_threshold));
		}

		CSR_WRITE_4(sc, COMMAND, COMMAND_TXUGO | COMMAND_TXQUEUED);
		epic_stop_activity(sc);
		epic_set_tx_mode(sc);
		epic_start_activity(sc);
		sc->sc_if.if_oerrors++;
	    }
	}
    }

    /* If no packets are pending, thus no timeouts */
    if( sc->pending_txs == 0 ) sc->sc_if.if_timer = 0;

#if defined(__OpenBSD__)
    return claimed;
#endif
}

/*
 * Synopsis: This one is called if packets wasn't transmitted
 * during timeout. Try to deallocate transmitted packets, and 
 * if success continue to work.
 */
static void
epic_ifwatchdog(ifp)
	struct ifnet *ifp;
{
	epic_softc_t *sc = ifp->if_softc;
	int x;

	x = splimp();

	printf(EPIC_FORMAT ": device timeout %d packets, ",
	    EPIC_ARGS(sc),sc->pending_txs);

	/* Try to finish queued packets */
	epic_tx_done( sc );

	/* If not successful */
	if( sc->pending_txs > 0 ){

		ifp->if_oerrors+=sc->pending_txs;

		/* Reinitialize board */
		printf("reinitialization\n");
		epic_stop(sc);
		epic_init(sc);

	} else 
		printf("seems we can continue normaly\n");

	/* Start output */
	if( ifp->if_snd.ifq_head ) epic_ifstart( ifp );

	splx(x);
}

/*
 * Set media options.
 */
static int
epic_ifmedia_upd(ifp)
	struct ifnet *ifp;
{
	epic_softc_t *sc;
	struct mii_data *mii;
	struct ifmedia *ifm;

	sc = ifp->if_softc;
	mii = device_get_softc(sc->miibus);
	ifm = &mii->mii_media;

	/* Do not do anything if interface is not up */
	if(!(ifp->if_flags & IFF_UP))
		return (0);

	if((IFM_INST(ifm->ifm_cur->ifm_media) == mii->mii_instance) &&
	   (IFM_SUBTYPE(ifm->ifm_cur->ifm_media) == IFM_10_2)) {
		/* Call this, to isolate (and powerdown ?) all PHYs */
		mii_mediachg(mii);

		/* Select BNC */
		CSR_WRITE_4(sc, MIICFG, MIICFG_SERIAL_ENABLE |
					MIICFG_694_ENABLE | MIICFG_SMI_ENABLE);

		/* Update txcon register */
		epic_miibus_statchg(sc->dev);

		return (0);
	} else if(IFM_INST(ifm->ifm_cur->ifm_media) < mii->mii_instance) {
		/* Select MII */
		CSR_WRITE_4(sc, MIICFG, MIICFG_SMI_ENABLE);

		/* Give it to miibus... */
		mii_mediachg(mii);

		return (0);
	}

	return(EINVAL);
}

/*
 * Report current media status.
 */
static void
epic_ifmedia_sts(ifp, ifmr)
	struct ifnet *ifp;
	struct ifmediareq *ifmr;
{
	epic_softc_t *sc;
	struct mii_data *mii;
	struct ifmedia *ifm;

	sc = ifp->if_softc;
	mii = device_get_softc(sc->miibus);
	ifm = &mii->mii_media;

	if(!(ifp->if_flags & IFF_UP)) {
		ifmr->ifm_active = IFM_NONE;
		ifmr->ifm_status = 0;

		return;
	}

	if((IFM_INST(ifm->ifm_cur->ifm_media) == mii->mii_instance) &&
	   (IFM_SUBTYPE(ifm->ifm_cur->ifm_media) == IFM_10_2)) {
		ifmr->ifm_active = ifm->ifm_cur->ifm_media;
		ifmr->ifm_status = 0;
	} else if(IFM_INST(ifm->ifm_cur->ifm_media) < mii->mii_instance) {
		mii_pollstat(mii);
		ifmr->ifm_active = mii->mii_media_active;
		ifmr->ifm_status = mii->mii_media_status;
	} else {
		ifmr->ifm_active = IFM_NONE;
		ifmr->ifm_status = 0;
	}

	return;
}

/*
 * Callback routine, called on media change.
 */
static void
epic_miibus_statchg(dev)
	device_t dev;
{
	epic_softc_t *sc;
	struct mii_data *mii;

	sc = device_get_softc(dev);
	mii = device_get_softc(sc->miibus);

	sc->txcon &= ~(TXCON_LOOPBACK_MODE | TXCON_FULL_DUPLEX);

	/*
	 * If we are in full-duplex mode or loopback operation,
	 * we need to decouple receiver and transmitter.
	 */
	if (mii->mii_media_active & (IFM_FDX | IFM_LOOP))
 		sc->txcon |= TXCON_FULL_DUPLEX;

	if (IFM_SUBTYPE(mii->mii_media_active) == IFM_100_TX)
		sc->sc_if.if_baudrate = 100000000;
	else
		sc->sc_if.if_baudrate = 10000000;

	epic_set_tx_mode(sc);

	return;
}

static void epic_miibus_mediainit(dev)
	device_t dev;
{
        epic_softc_t *sc;
        struct mii_data *mii;
	struct ifmedia *ifm;
	int media;
	
	sc = device_get_softc(dev);
	mii = device_get_softc(sc->miibus);
	ifm = &mii->mii_media;

	if(CSR_READ_4(sc, MIICFG) & MIICFG_PHY_PRESENT) {
		media = IFM_MAKEWORD(IFM_ETHER, IFM_10_2, 0, mii->mii_instance);
		printf(EPIC_FORMAT ": serial PHY detected (10Base2/BNC)\n",EPIC_ARGS(sc));
		ifmedia_add(ifm, media, 0, NULL);
	}

	return;
}


/*
 * Reset chip, allocate rings, and update media.
 */
static int
epic_init(sc)
	epic_softc_t *sc;
{       
	struct ifnet *ifp = &sc->sc_if;
	struct mii_data *mii;
	int s,i;
 
	s = splimp();

	/* If interface is already running, then we need not do anything */ 
	if (ifp->if_flags & IFF_RUNNING) {
		splx(s);
		return 0;
	}

	/* Soft reset the chip (we have to power up card before) */
	CSR_WRITE_4( sc, GENCTL, 0 );
	CSR_WRITE_4( sc, GENCTL, GENCTL_SOFT_RESET );

	/*
	 * Reset takes 15 pci ticks which depends on PCI bus speed.
	 * Assuming it >= 33000000 hz, we have wait at least 495e-6 sec.
	 */
	DELAY(500);

	/* Wake up */
	CSR_WRITE_4( sc, GENCTL, 0 );

	/* Workaround for Application Note 7-15 */
	for (i=0; i<16; i++) CSR_WRITE_4(sc, TEST1, TEST1_CLOCK_TEST);

	/* Initialize rings */
	if( epic_init_rings( sc ) ) {
		printf(EPIC_FORMAT ": failed to init rings\n",EPIC_ARGS(sc));
		splx(s);
		return -1;
	}	

	/* Give rings to EPIC */
	CSR_WRITE_4( sc, PRCDAR, vtophys( sc->rx_desc ) );
	CSR_WRITE_4( sc, PTCDAR, vtophys( sc->tx_desc ) );

	/* Put node address to EPIC */
	CSR_WRITE_4( sc, LAN0, ((u_int16_t *)sc->sc_macaddr)[0] );
        CSR_WRITE_4( sc, LAN1, ((u_int16_t *)sc->sc_macaddr)[1] );
	CSR_WRITE_4( sc, LAN2, ((u_int16_t *)sc->sc_macaddr)[2] );

	/* Set tx mode, includeing transmit threshold */
	epic_set_tx_mode(sc);

	/* Compute and set RXCON. */
	epic_set_rx_mode( sc );

	/* Set multicast table */
	epic_set_mc_table( sc );

	/* Enable interrupts by setting the interrupt mask. */
	CSR_WRITE_4( sc, INTMASK,
		INTSTAT_RCC | INTSTAT_RQE | INTSTAT_OVW | INTSTAT_RXE |
		INTSTAT_TXC | INTSTAT_TCC | INTSTAT_TQE | INTSTAT_TXU |
		INTSTAT_FATAL);

	/* Enable interrupts,  set for PCI read multiple and etc */
	CSR_WRITE_4( sc, GENCTL,
		GENCTL_ENABLE_INTERRUPT | GENCTL_MEMORY_READ_MULTIPLE |
		GENCTL_ONECOPY | GENCTL_RECEIVE_FIFO_THRESHOLD64 );

	/* Mark interface running ... */
	if( ifp->if_flags & IFF_UP ) ifp->if_flags |= IFF_RUNNING;
	else ifp->if_flags &= ~IFF_RUNNING;

	/* ... and free */
	ifp->if_flags &= ~IFF_OACTIVE;

	/* Start Rx process */
	epic_start_activity(sc);

	/* Reset all PHYs */
	mii = device_get_softc(sc->miibus);
        if (mii->mii_instance) {
		struct mii_softc	*miisc;
		for (miisc = LIST_FIRST(&mii->mii_phys); miisc != NULL;
		     miisc = LIST_NEXT(miisc, mii_list))
			mii_phy_reset(miisc);
	}

	/* Set appropriate media */
	epic_ifmedia_upd(ifp);

	splx(s);

	return 0;
}

/*
 * Synopsis: calculate and set Rx mode. Chip must be in idle state to
 * access RXCON.
 */
static void
epic_set_rx_mode(sc)
	epic_softc_t *sc;
{
	u_int32_t 		flags = sc->sc_if.if_flags;
        u_int32_t 		rxcon = RXCON_DEFAULT;

	rxcon |= (flags & IFF_PROMISC) ? RXCON_PROMISCUOUS_MODE : 0;

	CSR_WRITE_4( sc, RXCON, rxcon );

	return;
}

/*
 * Synopsis: Set transmit control register. Chip must be in idle state to
 * access TXCON.
 */
static void
epic_set_tx_mode(sc)
	epic_softc_t *sc;
{
	if (sc->txcon & TXCON_EARLY_TRANSMIT_ENABLE)
		CSR_WRITE_4 (sc, ETXTHR, sc->tx_threshold);

	CSR_WRITE_4 (sc, TXCON, sc->txcon);
}

/*
 * Synopsis: This function should update multicast hash table.
 * I suppose there is a bug in chips MC filter so this function
 * only set it to receive all MC packets. The second problem is
 * that we should wait for TX and RX processes to stop before
 * reprogramming MC filter. The epic_stop_activity() and 
 * epic_start_activity() should help to do this.
 */
static void
epic_set_mc_table(sc)
	epic_softc_t *sc;
{
	struct ifnet *ifp = &sc->sc_if;

	if( ifp->if_flags & IFF_MULTICAST ){
		CSR_WRITE_4( sc, MC0, 0xFFFF );
		CSR_WRITE_4( sc, MC1, 0xFFFF );
		CSR_WRITE_4( sc, MC2, 0xFFFF );
		CSR_WRITE_4( sc, MC3, 0xFFFF );
	}

	return;
}


/* 
 * Synopsis: Start receive process and transmit one, if they need.
 */
static void
epic_start_activity(sc)
	epic_softc_t *sc;
{
	/* Start rx process */
	CSR_WRITE_4(sc, COMMAND,
		COMMAND_RXQUEUED | COMMAND_START_RX |
		(sc->pending_txs?COMMAND_TXQUEUED:0));
	dprintf((EPIC_FORMAT ": activity started\n",EPIC_ARGS(sc)));
}

/*
 * Synopsis: Completely stop Rx and Tx processes. If TQE is set additional
 * packet needs to be queued to stop Tx DMA.
 */
static void
epic_stop_activity(sc)
    epic_softc_t *sc;
{
    int i;

    /* Stop Tx and Rx DMA */
    CSR_WRITE_4(sc,COMMAND,COMMAND_STOP_RX|COMMAND_STOP_RDMA|COMMAND_STOP_TDMA);

    /* Wait Rx and Tx DMA to stop (why 1 ms ??? XXX) */
    dprintf((EPIC_FORMAT ": waiting Rx and Tx DMA to stop\n",EPIC_ARGS(sc)));
    for(i=0;i<0x1000;i++) {
	if((CSR_READ_4(sc,INTSTAT) & (INTSTAT_TXIDLE | INTSTAT_RXIDLE)) == 
	   (INTSTAT_TXIDLE | INTSTAT_RXIDLE) )
	    break;
	DELAY(1);
    }

    if( !(CSR_READ_4(sc,INTSTAT)&INTSTAT_RXIDLE) ) 
	printf(EPIC_FORMAT ": can't stop Rx DMA\n",EPIC_ARGS(sc));

    if( !(CSR_READ_4(sc,INTSTAT)&INTSTAT_TXIDLE) ) 
	printf(EPIC_FORMAT ": can't stop Tx DMA\n",EPIC_ARGS(sc));

    /* Catch all finished packets */
    epic_rx_done(sc);
    epic_tx_done(sc);

    /*
     * May need to queue one more packet if TQE, this is rare but existing
     * case.
     */
    if( (CSR_READ_4( sc, INTSTAT ) & INTSTAT_TQE) &&
       !(CSR_READ_4( sc, INTSTAT ) & INTSTAT_TXIDLE) ) {
	struct epic_tx_desc *desc;
	struct epic_frag_list *flist;
	struct epic_tx_buffer *buf;
	struct mbuf *m0;

	dprintf((EPIC_FORMAT ": queue last packet\n",EPIC_ARGS(sc)));

	desc = sc->tx_desc + sc->cur_tx;
	flist = sc->tx_flist + sc->cur_tx;
	buf = sc->tx_buffer + sc->cur_tx;

	if ((desc->status & 0x8000) || (buf->mbuf != NULL))
	    return;

	MGETHDR(m0,M_DONTWAIT,MT_DATA);
	if (NULL == m0)
	    return;

	/* Prepare mbuf */
	m0->m_len = min(MHLEN,ETHER_MIN_LEN-ETHER_CRC_LEN);
	flist->frag[0].fraglen = m0->m_len;
	m0->m_pkthdr.len = m0->m_len;
	m0->m_pkthdr.rcvif = &sc->sc_if;
	bzero(mtod(m0,caddr_t),m0->m_len);

	/* Fill fragments list */
	flist->frag[0].fraglen = m0->m_len; 
	flist->frag[0].fragaddr = vtophys( mtod(m0, caddr_t) );
	flist->numfrags = 1;

	/* Fill in descriptor */
	buf->mbuf = m0;
	sc->pending_txs++;
	sc->cur_tx = (sc->cur_tx + 1) & TX_RING_MASK;
	desc->control = 0x01;
	desc->txlength = max(m0->m_pkthdr.len,ETHER_MIN_LEN-ETHER_CRC_LEN);
	desc->status = 0x8000;

	/* Launch transmition */
	CSR_WRITE_4(sc, COMMAND, COMMAND_STOP_TDMA | COMMAND_TXQUEUED);

	/* Wait Tx DMA to stop (for how long??? XXX) */
	dprintf((EPIC_FORMAT ": waiting Tx DMA to stop\n",EPIC_ARGS(sc)));
	for(i=0;i<1000;i++) {
	    if( (CSR_READ_4(sc,INTSTAT)&INTSTAT_TXIDLE) == INTSTAT_TXIDLE )
		break;
	    DELAY(1);
	}

	if( !(CSR_READ_4(sc,INTSTAT)&INTSTAT_TXIDLE) )
	    printf(EPIC_FORMAT ": can't stop TX DMA\n",EPIC_ARGS(sc));
	else
	    epic_tx_done(sc);
    }

    dprintf((EPIC_FORMAT ": activity stoped\n",EPIC_ARGS(sc)));
}

/*
 *  Synopsis: Shut down board and deallocates rings.
 */
static void
epic_stop(sc)
	epic_softc_t *sc;
{
	int s;

	s = splimp();

	sc->sc_if.if_timer = 0;

	/* Disable interrupts */
	CSR_WRITE_4( sc, INTMASK, 0 );
	CSR_WRITE_4( sc, GENCTL, 0 );

	/* Try to stop Rx and TX processes */
	epic_stop_activity(sc);

	/* Reset chip */
	CSR_WRITE_4( sc, GENCTL, GENCTL_SOFT_RESET );
	DELAY(1000);

	/* Make chip go to bed */
	CSR_WRITE_4(sc, GENCTL, GENCTL_POWER_DOWN);

	/* Free memory allocated for rings */
	epic_free_rings(sc);

	/* Mark as stoped */
	sc->sc_if.if_flags &= ~IFF_RUNNING;

	splx(s);
	return;
}

/*
 * Synopsis: This function should free all memory allocated for rings.
 */ 
static void
epic_free_rings(sc)
	epic_softc_t *sc;
{
	int i;

	for(i=0;i<RX_RING_SIZE;i++){
		struct epic_rx_buffer *buf = sc->rx_buffer + i;
		struct epic_rx_desc *desc = sc->rx_desc + i;
		
		desc->status = 0;
		desc->buflength = 0;
		desc->bufaddr = 0;

		if( buf->mbuf ) m_freem( buf->mbuf );
		buf->mbuf = NULL;
	}

	for(i=0;i<TX_RING_SIZE;i++){
		struct epic_tx_buffer *buf = sc->tx_buffer + i;
		struct epic_tx_desc *desc = sc->tx_desc + i;

		desc->status = 0;
		desc->buflength = 0;
		desc->bufaddr = 0;

		if( buf->mbuf ) m_freem( buf->mbuf );
		buf->mbuf = NULL;
	}
}

/*
 * Synopsis:  Allocates mbufs for Rx ring and point Rx descs to them.
 * Point Tx descs to fragment lists. Check that all descs and fraglists
 * are bounded and aligned properly.
 */
static int
epic_init_rings(sc)
	epic_softc_t *sc;
{
	int i;

	sc->cur_rx = sc->cur_tx = sc->dirty_tx = sc->pending_txs = 0;

	for (i = 0; i < RX_RING_SIZE; i++) {
		struct epic_rx_buffer *buf = sc->rx_buffer + i;
		struct epic_rx_desc *desc = sc->rx_desc + i;

		desc->status = 0;		/* Owned by driver */
		desc->next = vtophys( sc->rx_desc + ((i+1) & RX_RING_MASK) );

		if( (desc->next & 3) || ((desc->next & 0xFFF) + sizeof(struct epic_rx_desc) > 0x1000 ) )
			printf(EPIC_FORMAT ": WARNING! rx_desc is misbound or misaligned\n",EPIC_ARGS(sc));

		EPIC_MGETCLUSTER( buf->mbuf );
		if( NULL == buf->mbuf ) {
			epic_free_rings(sc);
			return -1;
		}
		desc->bufaddr = vtophys( mtod(buf->mbuf,caddr_t) );

		desc->buflength = ETHER_MAX_FRAME_LEN;
		desc->status = 0x8000;			/* Give to EPIC */

	}

	for (i = 0; i < TX_RING_SIZE; i++) {
		struct epic_tx_buffer *buf = sc->tx_buffer + i;
		struct epic_tx_desc *desc = sc->tx_desc + i;

		desc->status = 0;
		desc->next = vtophys( sc->tx_desc + ( (i+1) & TX_RING_MASK ) );

		if( (desc->next & 3) || ((desc->next & 0xFFF) + sizeof(struct epic_tx_desc) > 0x1000 ) )
			printf(EPIC_FORMAT ": WARNING! tx_desc is misbound or misaligned\n",EPIC_ARGS(sc));

		buf->mbuf = NULL;
		desc->bufaddr = vtophys( sc->tx_flist + i );
		if( (desc->bufaddr & 3) || ((desc->bufaddr & 0xFFF) + sizeof(struct epic_frag_list) > 0x1000 ) )
			printf(EPIC_FORMAT ": WARNING! frag_list is misbound or misaligned\n",EPIC_ARGS(sc));
	}

	return 0;
}

/*
 * EEPROM operation functions
 */
static void
epic_write_eepromreg(sc, val)
	epic_softc_t *sc;
	u_int8_t val;
{
	u_int16_t i;

	CSR_WRITE_1( sc, EECTL, val );

	for (i=0; i<0xFF; i++)
		if( !(CSR_READ_1( sc, EECTL ) & 0x20) ) break;

	return;
}

static u_int8_t
epic_read_eepromreg(sc)
	epic_softc_t *sc;
{
	return CSR_READ_1(sc, EECTL);
}  

static u_int8_t
epic_eeprom_clock(sc, val)
	epic_softc_t *sc;
	u_int8_t val;
{
	epic_write_eepromreg( sc, val );
	epic_write_eepromreg( sc, (val | 0x4) );
	epic_write_eepromreg( sc, val );
	
	return epic_read_eepromreg( sc );
}

static void
epic_output_eepromw(sc, val)
	epic_softc_t *sc;
	u_int16_t val;
{
	int i;          
	for( i = 0xF; i >= 0; i--){
		if( (val & (1 << i)) ) epic_eeprom_clock( sc, 0x0B );
		else epic_eeprom_clock( sc, 3);
	}
}

static u_int16_t
epic_input_eepromw(sc)
	epic_softc_t *sc;
{
	int i;
	int tmp;
	u_int16_t retval = 0;

	for( i = 0xF; i >= 0; i--) {	
		tmp = epic_eeprom_clock( sc, 0x3 );
		if( tmp & 0x10 ){
			retval |= (1 << i);
		}
	}
	return retval;
}

static int
epic_read_eeprom(sc, loc)
	epic_softc_t *sc;
	u_int16_t loc;
{
	u_int16_t dataval;
	u_int16_t read_cmd;

	epic_write_eepromreg( sc , 3);

	if( epic_read_eepromreg( sc ) & 0x40 )
		read_cmd = ( loc & 0x3F ) | 0x180;
	else
		read_cmd = ( loc & 0xFF ) | 0x600;

	epic_output_eepromw( sc, read_cmd );

        dataval = epic_input_eepromw( sc );

	epic_write_eepromreg( sc, 1 );
	
	return dataval;
}

/*
 * Here goes MII read/write routines
 */
static int
epic_read_phy_reg(sc, phy, reg)
	epic_softc_t *sc;
	int phy, reg;
{
	int i;

	CSR_WRITE_4 (sc, MIICTL, ((reg << 4) | (phy << 9) | 0x01));

	for (i=0;i<0x100;i++) {
		if( !(CSR_READ_4(sc, MIICTL) & 0x01) ) break;
		DELAY(1);
	}

	return (CSR_READ_4 (sc, MIIDATA));
}

static void
epic_write_phy_reg(sc, phy, reg, val)
	epic_softc_t *sc;
	int phy, reg, val;
{
	int i;

	CSR_WRITE_4 (sc, MIIDATA, val);
	CSR_WRITE_4 (sc, MIICTL, ((reg << 4) | (phy << 9) | 0x02));

	for(i=0;i<0x100;i++) {
		if( !(CSR_READ_4(sc, MIICTL) & 0x02) ) break;
		DELAY(1);
	}

	return;
}

static int
epic_miibus_readreg(dev, phy, reg)
	device_t dev;
	int phy, reg;
{
	epic_softc_t *sc;

	sc = device_get_softc(dev);

	return (PHY_READ_2(sc, phy, reg));
}

static int
epic_miibus_writereg(dev, phy, reg, data)
	device_t dev;
	int phy, reg, data;
{
	epic_softc_t *sc;

	sc = device_get_softc(dev);

	PHY_WRITE_2(sc, phy, reg, data);

	return (0);
}