NetBSD/sys/dev/qbus/if_de.c

666 lines
18 KiB
C

/* $NetBSD: if_de.c,v 1.29 2010/04/05 07:21:47 joerg Exp $ */
/*
* Copyright (c) 1982, 1986, 1989 Regents of the University of California.
* All rights reserved.
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)if_de.c 7.12 (Berkeley) 12/16/90
*/
/*
* Copyright (c) 2000 Ludd, University of Lule}, Sweden.
* All rights reserved.
*
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)if_de.c 7.12 (Berkeley) 12/16/90
*/
/*
* DEC DEUNA interface
*
* Lou Salkind
* New York University
*
* Rewritten by Ragge 30 April 2000 to match new world.
*
* TODO:
* timeout routine (get statistics)
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_de.c,v 1.29 2010/04/05 07:21:47 joerg Exp $");
#include "opt_inet.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/buf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/syslog.h>
#include <sys/device.h>
#include <net/if.h>
#include <net/if_ether.h>
#include <net/if_dl.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/if_inarp.h>
#endif
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <sys/bus.h>
#include <dev/qbus/ubavar.h>
#include <dev/qbus/if_dereg.h>
#include <dev/qbus/if_uba.h>
#include "ioconf.h"
/*
* Be careful with transmit/receive buffers, each entry steals 4 map
* registers, and there is only 496 on one unibus...
*/
#define NRCV 7 /* number of receive buffers (must be > 1) */
#define NXMT 3 /* number of transmit buffers */
/*
* Structure containing the elements that must be in DMA-safe memory.
*/
struct de_cdata {
/* the following structures are always mapped in */
struct de_pcbb dc_pcbb; /* port control block */
struct de_ring dc_xrent[NXMT]; /* transmit ring entrys */
struct de_ring dc_rrent[NRCV]; /* receive ring entrys */
struct de_udbbuf dc_udbbuf; /* UNIBUS data buffer */
/* end mapped area */
};
/*
* Ethernet software status per interface.
*
* Each interface is referenced by a network interface structure,
* ds_if, which the routing code uses to locate the interface.
* This structure contains the output queue for the interface, its address, ...
* We also have, for each interface, a UBA interface structure, which
* contains information about the UNIBUS resources held by the interface:
* map registers, buffered data paths, etc. Information is cached in this
* structure for use by the if_uba.c routines in running the interface
* efficiently.
*/
struct de_softc {
device_t sc_dev; /* Configuration common part */
struct uba_softc *sc_uh; /* our parent */
struct evcnt sc_intrcnt; /* Interrupt counting */
struct ethercom sc_ec; /* Ethernet common part */
#define sc_if sc_ec.ec_if /* network-visible interface */
bus_space_tag_t sc_iot;
bus_addr_t sc_ioh;
bus_dma_tag_t sc_dmat;
int sc_flags;
#define DSF_MAPPED 1
struct ubinfo sc_ui;
struct de_cdata *sc_dedata; /* Control structure */
struct de_cdata *sc_pdedata; /* Bus-mapped control structure */
struct ifubinfo sc_ifuba; /* UNIBUS resources */
struct ifrw sc_ifr[NRCV]; /* UNIBUS receive buffer maps */
struct ifxmt sc_ifw[NXMT]; /* UNIBUS receive buffer maps */
int sc_xindex; /* UNA index into transmit chain */
int sc_rindex; /* UNA index into receive chain */
int sc_xfree; /* index for next transmit buffer */
int sc_nxmit; /* # of transmits in progress */
void *sc_sh; /* shutdownhook cookie */
};
static int dematch(device_t, cfdata_t, void *);
static void deattach(device_t, device_t, void *);
static void dewait(struct de_softc *, const char *);
static int deinit(struct ifnet *);
static int deioctl(struct ifnet *, u_long, void *);
static void dereset(device_t);
static void destop(struct ifnet *, int);
static void destart(struct ifnet *);
static void derecv(struct de_softc *);
static void deintr(void *);
static void deshutdown(void *);
CFATTACH_DECL_NEW(de, sizeof(struct de_softc),
dematch, deattach, NULL, NULL);
#define DE_WCSR(csr, val) \
bus_space_write_2(sc->sc_iot, sc->sc_ioh, csr, val)
#define DE_WLOW(val) \
bus_space_write_1(sc->sc_iot, sc->sc_ioh, DE_PCSR0, val)
#define DE_WHIGH(val) \
bus_space_write_1(sc->sc_iot, sc->sc_ioh, DE_PCSR0 + 1, val)
#define DE_RCSR(csr) \
bus_space_read_2(sc->sc_iot, sc->sc_ioh, csr)
#define LOWORD(x) ((int)(x) & 0xffff)
#define HIWORD(x) (((int)(x) >> 16) & 0x3)
/*
* Interface exists: make available by filling in network interface
* record. System will initialize the interface when it is ready
* to accept packets. We get the ethernet address here.
*/
void
deattach(device_t parent, device_t self, void *aux)
{
struct uba_attach_args *ua = aux;
struct de_softc *sc = device_private(self);
struct ifnet *ifp = &sc->sc_if;
u_int8_t myaddr[ETHER_ADDR_LEN];
int csr1, error;
const char *c;
sc->sc_dev = self;
sc->sc_uh = device_private(parent);
sc->sc_iot = ua->ua_iot;
sc->sc_ioh = ua->ua_ioh;
sc->sc_dmat = ua->ua_dmat;
/*
* What kind of a board is this?
* The error bits 4-6 in pcsr1 are a device id as long as
* the high byte is zero.
*/
csr1 = DE_RCSR(DE_PCSR1);
if (csr1 & 0xff60)
c = "broken";
else if (csr1 & 0x10)
c = "delua";
else
c = "deuna";
/*
* Reset the board and temporarily map
* the pcbb buffer onto the Unibus.
*/
DE_WCSR(DE_PCSR0, 0); /* reset INTE */
DELAY(100);
DE_WCSR(DE_PCSR0, PCSR0_RSET);
dewait(sc, "reset");
sc->sc_ui.ui_size = sizeof(struct de_cdata);
if ((error = ubmemalloc(sc->sc_uh, &sc->sc_ui, 0)))
return printf(": failed ubmemalloc(), error = %d\n", error);
sc->sc_dedata = (struct de_cdata *)sc->sc_ui.ui_vaddr;
/*
* Tell the DEUNA about our PCB
*/
DE_WCSR(DE_PCSR2, LOWORD(sc->sc_ui.ui_baddr));
DE_WCSR(DE_PCSR3, HIWORD(sc->sc_ui.ui_baddr));
DE_WLOW(CMD_GETPCBB);
dewait(sc, "pcbb");
sc->sc_dedata->dc_pcbb.pcbb0 = FC_RDPHYAD;
DE_WLOW(CMD_GETCMD);
dewait(sc, "read addr ");
memcpy(myaddr, (void *)&sc->sc_dedata->dc_pcbb.pcbb2, sizeof (myaddr));
printf(": %s, hardware address %s\n", c, ether_sprintf(myaddr));
uba_intr_establish(ua->ua_icookie, ua->ua_cvec, deintr, sc,
&sc->sc_intrcnt);
uba_reset_establish(dereset, sc->sc_dev);
evcnt_attach_dynamic(&sc->sc_intrcnt, EVCNT_TYPE_INTR, ua->ua_evcnt,
device_xname(sc->sc_dev), "intr");
strcpy(ifp->if_xname, device_xname(sc->sc_dev));
ifp->if_softc = sc;
ifp->if_flags = IFF_BROADCAST|IFF_SIMPLEX|IFF_MULTICAST|IFF_ALLMULTI;
ifp->if_ioctl = deioctl;
ifp->if_start = destart;
ifp->if_init = deinit;
ifp->if_stop = destop;
IFQ_SET_READY(&ifp->if_snd);
if_attach(ifp);
ether_ifattach(ifp, myaddr);
ubmemfree(sc->sc_uh, &sc->sc_ui);
sc->sc_sh = shutdownhook_establish(deshutdown, sc);
}
void
destop(struct ifnet *ifp, int a)
{
struct de_softc *sc = ifp->if_softc;
DE_WLOW(0);
DELAY(5000);
DE_WLOW(PCSR0_RSET);
}
/*
* Reset of interface after UNIBUS reset.
*/
void
dereset(device_t dev)
{
struct de_softc *sc = (void *)dev;
sc->sc_if.if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
sc->sc_flags &= ~DSF_MAPPED;
sc->sc_pdedata = NULL; /* All mappings lost */
DE_WCSR(DE_PCSR0, PCSR0_RSET);
dewait(sc, "reset");
deinit(&sc->sc_if);
}
/*
* Initialization of interface; clear recorded pending
* operations, and reinitialize UNIBUS usage.
*/
int
deinit(struct ifnet *ifp)
{
struct de_softc *sc = ifp->if_softc;
struct de_cdata *dc, *pdc;
struct ifrw *ifrw;
struct ifxmt *ifxp;
struct de_ring *rp;
int s, error;
if (ifp->if_flags & IFF_RUNNING)
return 0;
if ((sc->sc_flags & DSF_MAPPED) == 0) {
if (if_ubaminit(&sc->sc_ifuba, sc->sc_uh, MCLBYTES,
sc->sc_ifr, NRCV, sc->sc_ifw, NXMT)) {
aprint_error_dev(sc->sc_dev, " can't initialize\n");
ifp->if_flags &= ~IFF_UP;
return 0;
}
sc->sc_ui.ui_size = sizeof(struct de_cdata);
if ((error = ubmemalloc(sc->sc_uh, &sc->sc_ui, 0))) {
aprint_error(": unable to ubmemalloc(), error = %d\n",
error);
return 0;
}
sc->sc_pdedata = (struct de_cdata *)sc->sc_ui.ui_baddr;
sc->sc_dedata = (struct de_cdata *)sc->sc_ui.ui_vaddr;
sc->sc_flags |= DSF_MAPPED;
}
/*
* Tell the DEUNA about our PCB
*/
DE_WCSR(DE_PCSR2, LOWORD(sc->sc_pdedata));
DE_WCSR(DE_PCSR3, HIWORD(sc->sc_pdedata));
DE_WLOW(0); /* reset INTE */
DELAY(500);
DE_WLOW(CMD_GETPCBB);
dewait(sc, "pcbb");
dc = sc->sc_dedata;
pdc = sc->sc_pdedata;
/* set the transmit and receive ring header addresses */
dc->dc_pcbb.pcbb0 = FC_WTRING;
dc->dc_pcbb.pcbb2 = LOWORD(&pdc->dc_udbbuf);
dc->dc_pcbb.pcbb4 = HIWORD(&pdc->dc_udbbuf);
dc->dc_udbbuf.b_tdrbl = LOWORD(&pdc->dc_xrent[0]);
dc->dc_udbbuf.b_tdrbh = HIWORD(&pdc->dc_xrent[0]);
dc->dc_udbbuf.b_telen = sizeof (struct de_ring) / sizeof(u_int16_t);
dc->dc_udbbuf.b_trlen = NXMT;
dc->dc_udbbuf.b_rdrbl = LOWORD(&pdc->dc_rrent[0]);
dc->dc_udbbuf.b_rdrbh = HIWORD(&pdc->dc_rrent[0]);
dc->dc_udbbuf.b_relen = sizeof (struct de_ring) / sizeof(u_int16_t);
dc->dc_udbbuf.b_rrlen = NRCV;
DE_WLOW(CMD_GETCMD);
dewait(sc, "wtring");
sc->sc_dedata->dc_pcbb.pcbb0 = FC_WTMODE;
sc->sc_dedata->dc_pcbb.pcbb2 = MOD_TPAD|MOD_HDX|MOD_DRDC|MOD_ENAL;
DE_WLOW(CMD_GETCMD);
dewait(sc, "wtmode");
/* set up the receive and transmit ring entries */
ifxp = &sc->sc_ifw[0];
for (rp = &dc->dc_xrent[0]; rp < &dc->dc_xrent[NXMT]; rp++) {
rp->r_segbl = LOWORD(ifxp->ifw_info);
rp->r_segbh = HIWORD(ifxp->ifw_info);
rp->r_flags = 0;
ifxp++;
}
ifrw = &sc->sc_ifr[0];
for (rp = &dc->dc_rrent[0]; rp < &dc->dc_rrent[NRCV]; rp++) {
rp->r_slen = MCLBYTES - 2;
rp->r_segbl = LOWORD(ifrw->ifrw_info);
rp->r_segbh = HIWORD(ifrw->ifrw_info);
rp->r_flags = RFLG_OWN;
ifrw++;
}
/* start up the board (rah rah) */
s = splnet();
sc->sc_rindex = sc->sc_xindex = sc->sc_xfree = sc->sc_nxmit = 0;
sc->sc_if.if_flags |= IFF_RUNNING;
DE_WLOW(PCSR0_INTE); /* avoid interlock */
destart(&sc->sc_if); /* queue output packets */
DE_WLOW(CMD_START|PCSR0_INTE);
splx(s);
return 0;
}
/*
* Setup output on interface.
* Get another datagram to send off of the interface queue,
* and map it to the interface before starting the output.
* Must be called from ipl >= our interrupt level.
*/
void
destart(struct ifnet *ifp)
{
struct de_softc *sc = ifp->if_softc;
struct de_cdata *dc;
struct de_ring *rp;
struct mbuf *m;
int nxmit, len;
/*
* the following test is necessary, since
* the code is not reentrant and we have
* multiple transmission buffers.
*/
if (sc->sc_if.if_flags & IFF_OACTIVE)
return;
dc = sc->sc_dedata;
for (nxmit = sc->sc_nxmit; nxmit < NXMT; nxmit++) {
IFQ_DEQUEUE(&ifp->if_snd, m);
if (m == 0)
break;
rp = &dc->dc_xrent[sc->sc_xfree];
if (rp->r_flags & XFLG_OWN)
panic("deuna xmit in progress");
bpf_mtap(ifp, m);
len = if_ubaput(&sc->sc_ifuba, &sc->sc_ifw[sc->sc_xfree], m);
rp->r_slen = len;
rp->r_tdrerr = 0;
rp->r_flags = XFLG_STP|XFLG_ENP|XFLG_OWN;
sc->sc_xfree++;
if (sc->sc_xfree == NXMT)
sc->sc_xfree = 0;
}
if (sc->sc_nxmit != nxmit) {
sc->sc_nxmit = nxmit;
if (ifp->if_flags & IFF_RUNNING)
DE_WLOW(PCSR0_INTE|CMD_PDMD);
}
}
/*
* Command done interrupt.
*/
void
deintr(void *arg)
{
struct ifxmt *ifxp;
struct de_cdata *dc;
struct de_softc *sc = arg;
struct de_ring *rp;
short csr0;
/* save flags right away - clear out interrupt bits */
csr0 = DE_RCSR(DE_PCSR0);
DE_WHIGH(csr0 >> 8);
sc->sc_if.if_flags |= IFF_OACTIVE; /* prevent entering destart */
/*
* if receive, put receive buffer on mbuf
* and hang the request again
*/
derecv(sc);
/*
* Poll transmit ring and check status.
* Be careful about loopback requests.
* Then free buffer space and check for
* more transmit requests.
*/
dc = sc->sc_dedata;
for ( ; sc->sc_nxmit > 0; sc->sc_nxmit--) {
rp = &dc->dc_xrent[sc->sc_xindex];
if (rp->r_flags & XFLG_OWN)
break;
sc->sc_if.if_opackets++;
ifxp = &sc->sc_ifw[sc->sc_xindex];
/* check for unusual conditions */
if (rp->r_flags & (XFLG_ERRS|XFLG_MTCH|XFLG_ONE|XFLG_MORE)) {
if (rp->r_flags & XFLG_ERRS) {
/* output error */
sc->sc_if.if_oerrors++;
} else if (rp->r_flags & XFLG_ONE) {
/* one collision */
sc->sc_if.if_collisions++;
} else if (rp->r_flags & XFLG_MORE) {
/* more than one collision */
sc->sc_if.if_collisions += 2; /* guess */
}
}
if_ubaend(&sc->sc_ifuba, ifxp);
/* check if next transmit buffer also finished */
sc->sc_xindex++;
if (sc->sc_xindex == NXMT)
sc->sc_xindex = 0;
}
sc->sc_if.if_flags &= ~IFF_OACTIVE;
destart(&sc->sc_if);
if (csr0 & PCSR0_RCBI) {
DE_WLOW(PCSR0_INTE|CMD_PDMD);
}
}
/*
* Ethernet interface receiver interface.
* If input error just drop packet.
* Otherwise purge input buffered data path and examine
* packet to determine type. If can't determine length
* from type, then have to drop packet. Othewise decapsulate
* packet based on type and pass to type specific higher-level
* input routine.
*/
void
derecv(struct de_softc *sc)
{
struct ifnet *ifp = &sc->sc_if;
struct de_ring *rp;
struct de_cdata *dc;
struct mbuf *m;
int len;
dc = sc->sc_dedata;
rp = &dc->dc_rrent[sc->sc_rindex];
while ((rp->r_flags & RFLG_OWN) == 0) {
sc->sc_if.if_ipackets++;
len = (rp->r_lenerr&RERR_MLEN) - ETHER_CRC_LEN;
/* check for errors */
if ((rp->r_flags & (RFLG_ERRS|RFLG_FRAM|RFLG_OFLO|RFLG_CRC)) ||
(rp->r_lenerr & (RERR_BUFL|RERR_UBTO))) {
sc->sc_if.if_ierrors++;
goto next;
}
m = if_ubaget(&sc->sc_ifuba, &sc->sc_ifr[sc->sc_rindex],
ifp, len);
if (m == 0) {
sc->sc_if.if_ierrors++;
goto next;
}
bpf_mtap(ifp, m);
(*ifp->if_input)(ifp, m);
/* hang the receive buffer again */
next: rp->r_lenerr = 0;
rp->r_flags = RFLG_OWN;
/* check next receive buffer */
sc->sc_rindex++;
if (sc->sc_rindex == NRCV)
sc->sc_rindex = 0;
rp = &dc->dc_rrent[sc->sc_rindex];
}
}
/*
* Process an ioctl request.
*/
int
deioctl(struct ifnet *ifp, u_long cmd, void *data)
{
int s, error = 0;
s = splnet();
error = ether_ioctl(ifp, cmd, data);
if (error == ENETRESET)
error = 0;
splx(s);
return (error);
}
/*
* Await completion of the named function
* and check for errors.
*/
void
dewait(struct de_softc *sc, const char *fn)
{
int csr0, csr1;
while ((DE_RCSR(DE_PCSR0) & PCSR0_INTR) == 0)
;
csr0 = DE_RCSR(DE_PCSR0);
DE_WHIGH(csr0 >> 8);
if (csr0 & PCSR0_PCEI) {
char bits0[64];
char bits1[64];
csr1 = DE_RCSR(DE_PCSR1);
snprintb(bits0, sizeof(bits0), PCSR0_BITS, csr0);
snprintb(bits1, sizeof(bits1), PCSR1_BITS, csr1);
aprint_error_dev(sc->sc_dev, "%s failed, csr0=%s csr1=%s\n",
fn, bits0, bits1);
}
}
int
dematch(device_t parent, cfdata_t cf, void *aux)
{
struct uba_attach_args *ua = aux;
struct de_softc ssc;
struct de_softc *sc = &ssc;
int i;
sc->sc_iot = ua->ua_iot;
sc->sc_ioh = ua->ua_ioh;
/*
* Make sure self-test is finished before we screw with the board.
* Self-test on a DELUA can take 15 seconds (argh).
*/
for (i = 0;
(i < 160) &&
(DE_RCSR(DE_PCSR0) & PCSR0_FATI) == 0 &&
(DE_RCSR(DE_PCSR1) & PCSR1_STMASK) == STAT_RESET;
++i)
DELAY(50000);
if (((DE_RCSR(DE_PCSR0) & PCSR0_FATI) != 0) ||
(((DE_RCSR(DE_PCSR1) & PCSR1_STMASK) != STAT_READY) &&
((DE_RCSR(DE_PCSR1) & PCSR1_STMASK) != STAT_RUN)))
return(0);
DE_WCSR(DE_PCSR0, 0);
DELAY(5000);
DE_WCSR(DE_PCSR0, PCSR0_RSET);
while ((DE_RCSR(DE_PCSR0) & PCSR0_INTR) == 0)
;
/* make board interrupt by executing a GETPCBB command */
DE_WCSR(DE_PCSR0, PCSR0_INTE);
DE_WCSR(DE_PCSR2, 0);
DE_WCSR(DE_PCSR3, 0);
DE_WCSR(DE_PCSR0, PCSR0_INTE|CMD_GETPCBB);
DELAY(50000);
return 1;
}
void
deshutdown(void *arg)
{
struct de_softc *sc = arg;
DE_WCSR(DE_PCSR0, 0);
DELAY(1000);
DE_WCSR(DE_PCSR0, PCSR0_RSET);
dewait(sc, "shutdown");
}