if_ep.c revision 30398
1/*
2 * Copyright (c) 1994 Herb Peyerl <hpeyerl@novatel.ca>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *      This product includes software developed by Herb Peyerl.
16 * 4. The name of Herb Peyerl may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 *	if_ep.c,v 1.19 1995/01/24 20:53:45 davidg Exp
31 */
32
33/*
34 *	Modified from the FreeBSD 1.1.5.1 version by:
35 *		 	Andres Vega Garcia
36 *			INRIA - Sophia Antipolis, France
37 *			avega@sophia.inria.fr
38 */
39
40/*
41 *  $Id: if_ep.c,v 1.60 1997/09/02 01:18:13 bde Exp $
42 *
43 *  Promiscuous mode added and interrupt logic slightly changed
44 *  to reduce the number of adapter failures. Transceiver select
45 *  logic changed to use value from EEPROM. Autoconfiguration
46 *  features added.
47 *  Done by:
48 *          Serge Babkin
49 *          Chelindbank (Chelyabinsk, Russia)
50 *          babkin@hq.icb.chel.su
51 */
52
53/*
54 * Pccard support for 3C589 by:
55 *		HAMADA Naoki
56 *		nao@tom-yam.or.jp
57 */
58
59#include "ep.h"
60#if NEP > 0
61
62#include "bpfilter.h"
63
64#include <sys/param.h>
65#if defined(__FreeBSD__)
66#include <sys/systm.h>
67#include <sys/conf.h>
68#endif
69#include <sys/malloc.h>
70#include <sys/mbuf.h>
71#include <sys/socket.h>
72#include <sys/sockio.h>
73#if defined(__NetBSD__)
74#include <sys/select.h>
75#endif
76
77#include <net/if.h>
78
79#ifdef INET
80#include <netinet/in.h>
81#include <netinet/if_ether.h>
82#endif
83
84#ifdef IPX
85#include <netipx/ipx.h>
86#include <netipx/ipx_if.h>
87#endif
88
89#ifdef NS
90#include <netns/ns.h>
91#include <netns/ns_if.h>
92#endif
93
94#if NBPFILTER > 0
95#include <net/bpf.h>
96#endif
97
98#if defined(__FreeBSD__)
99#include <machine/clock.h>
100#endif
101
102#include <i386/isa/isa_device.h>
103#include <i386/isa/if_epreg.h>
104#include <i386/isa/elink.h>
105
106/* Exported variables */
107u_long	ep_unit;
108int	ep_boards;
109struct	ep_board ep_board[EP_MAX_BOARDS + 1];
110
111static	int eeprom_rdy __P((struct ep_softc *sc));
112
113static	int ep_isa_probe __P((struct isa_device *));
114static struct ep_board * ep_look_for_board_at __P((struct isa_device *is));
115static	int ep_isa_attach __P((struct isa_device *));
116static	int epioctl __P((struct ifnet * ifp, int, caddr_t));
117
118static	void epinit __P((struct ep_softc *));
119static	void epread __P((struct ep_softc *));
120void	epreset __P((int));
121static	void epstart __P((struct ifnet *));
122static	void epstop __P((struct ep_softc *));
123static	void epwatchdog __P((struct ifnet *));
124
125#if 0
126static	int send_ID_sequence __P((int));
127#endif
128static	int get_eeprom_data __P((int, int));
129
130static	struct ep_softc* ep_softc[NEP];
131static	int ep_current_tag = EP_LAST_TAG + 1;
132static	char *ep_conn_type[] = {"UTP", "AUI", "???", "BNC"};
133
134#define ep_ftst(f) (sc->stat&(f))
135#define ep_fset(f) (sc->stat|=(f))
136#define ep_frst(f) (sc->stat&=~(f))
137
138struct isa_driver epdriver = {
139    ep_isa_probe,
140    ep_isa_attach,
141    "ep",
142    0
143};
144
145#include "crd.h"
146
147#if NCRD > 0
148#include <sys/select.h>
149#include <pccard/card.h>
150#include <pccard/driver.h>
151#include <pccard/slot.h>
152
153/*
154 * PC-Card (PCMCIA) specific code.
155 */
156static int card_intr __P((struct pccard_dev *));
157static void ep_unload __P((struct pccard_dev *));
158static void ep_suspend __P((struct pccard_dev *));
159static int ep_pccard_init __P((struct pccard_dev *, int));
160static int ep_pccard_attach  __P((struct pccard_dev *));
161
162static struct pccard_drv ep_info = {
163    "ep",
164    card_intr,
165    ep_unload,
166    ep_suspend,
167    ep_pccard_init,
168    0,                      /* Attributes - presently unused */
169    &net_imask
170};
171
172/* Resume is done by executing ep_pccard_init(dp, 0). */
173static void
174ep_suspend(dp)
175    struct pccard_dev *dp;
176{
177    struct ep_softc *sc = ep_softc[dp->isahd.id_unit];
178
179    printf("ep%d: suspending\n", dp->isahd.id_unit);
180    sc->gone = 1;
181}
182
183/*
184 *
185 */
186static int
187ep_pccard_init(dp, first)
188    struct pccard_dev *dp;
189    int first;
190{
191    struct isa_device *is = &dp->isahd;
192    struct ep_softc *sc = ep_softc[is->id_unit];
193    struct ep_board *epb;
194    int i;
195
196    epb = &ep_board[is->id_unit];
197
198    if (sc == 0) {
199	if ((sc = ep_alloc(is->id_unit, epb)) == 0) {
200	    return (ENXIO);
201	}
202	ep_unit++;
203    }
204
205    /* get_e() requires these. */
206    sc->ep_io_addr = is->id_iobase;
207    sc->unit = is->id_unit;
208
209    epb->epb_addr = is->id_iobase;
210    epb->epb_used = 1;
211    epb->prod_id = get_e(sc, EEPROM_PROD_ID);
212
213    if (epb->prod_id != 0x9058) {	/* 3C589's product id */
214	if (first) {
215	    printf("ep%d: failed to come ready.\n", is->id_unit);
216	} else {
217	    printf("ep%d: failed to resume.\n", is->id_unit);
218	}
219	return (ENXIO);
220    }
221
222    epb->res_cfg = get_e(sc, EEPROM_RESOURCE_CFG);
223    for (i = 0; i < 3; i++) {
224        sc->epb->eth_addr[i] = get_e(sc, EEPROM_NODE_ADDR_0 + i);
225    }
226
227    if (first) {
228	if (ep_pccard_attach(dp) == 0) {
229	    return (ENXIO);
230	}
231	sc->arpcom.ac_if.if_snd.ifq_maxlen = ifqmaxlen;
232    }
233
234    if (!first) {
235	sc->gone = 0;
236	printf("ep%d: resumed.\n", is->id_unit);
237	epinit(sc);
238    }
239
240    return (0);
241}
242
243static int
244ep_pccard_attach(dp)
245    struct pccard_dev *dp;
246{
247    struct isa_device *is = &dp->isahd;
248    struct ep_softc *sc = ep_softc[is->id_unit];
249    u_short config;
250
251    sc->ep_connectors = 0;
252    config = inw(IS_BASE + EP_W0_CONFIG_CTRL);
253    if (config & IS_BNC) {
254	sc->ep_connectors |= BNC;
255    }
256    if (config & IS_UTP) {
257	sc->ep_connectors |= UTP;
258    }
259    if (!(sc->ep_connectors & 7))
260	printf("no connectors!");
261    sc->ep_connector = inw(BASE + EP_W0_ADDRESS_CFG) >> ACF_CONNECTOR_BITS;
262
263    /* ROM size = 0, ROM base = 0 */
264    /* For now, ignore AUTO SELECT feature of 3C589B and later. */
265    outw(BASE + EP_W0_ADDRESS_CFG, get_e(sc, EEPROM_ADDR_CFG) & 0xc000);
266
267    /* Fake IRQ must be 3 */
268    outw(BASE + EP_W0_RESOURCE_CFG, (sc->epb->res_cfg & 0x0fff) | 0x3000);
269
270    outw(BASE + EP_W0_PRODUCT_ID, sc->epb->prod_id);
271
272    ep_attach(sc);
273
274    return 1;
275}
276
277static void
278ep_unload(dp)
279    struct pccard_dev *dp;
280{
281    struct ep_softc *sc = ep_softc[dp->isahd.id_unit];
282
283    if (sc->gone) {
284        printf("ep%d: already unloaded\n", dp->isahd.id_unit);
285	return;
286    }
287    sc->arpcom.ac_if.if_flags &= ~IFF_RUNNING;
288    sc->gone = 1;
289    printf("ep%d: unload\n", dp->isahd.id_unit);
290}
291
292/*
293 * card_intr - Shared interrupt called from
294 * front end of PC-Card handler.
295 */
296static int
297card_intr(dp)
298    struct pccard_dev *dp;
299{
300    epintr(dp->isahd.id_unit);
301    return(1);
302}
303
304#endif /* NCRD > 0 */
305
306static int
307eeprom_rdy(sc)
308    struct ep_softc *sc;
309{
310    int i;
311
312    for (i = 0; is_eeprom_busy(BASE) && i < MAX_EEPROMBUSY; i++);
313    if (i >= MAX_EEPROMBUSY) {
314	printf("ep%d: eeprom failed to come ready.\n", sc->unit);
315	return (0);
316    }
317    return (1);
318}
319
320static struct ep_board *
321ep_look_for_board_at(is)
322    struct isa_device *is;
323{
324    int data, i, j, id_port = ELINK_ID_PORT;
325    int count = 0;
326
327    if (ep_current_tag == (EP_LAST_TAG + 1)) {
328	/* Come here just one time */
329
330	ep_current_tag--;
331
332        /* Look for the ISA boards. Init and leave them actived */
333	outb(id_port, 0);
334	outb(id_port, 0);
335
336	elink_idseq(0xCF);
337
338	elink_reset();
339	DELAY(10000);
340	for (i = 0; i < EP_MAX_BOARDS; i++) {
341	    outb(id_port, 0);
342	    outb(id_port, 0);
343	    elink_idseq(0xCF);
344
345	    data = get_eeprom_data(id_port, EEPROM_MFG_ID);
346	    if (data != MFG_ID)
347		break;
348
349	    /* resolve contention using the Ethernet address */
350
351	    for (j = 0; j < 3; j++)
352		 get_eeprom_data(id_port, j);
353
354	    /* and save this address for later use */
355
356	    for (j = 0; j < 3; j++)
357		 ep_board[ep_boards].eth_addr[j] = get_eeprom_data(id_port, j);
358
359	    ep_board[ep_boards].res_cfg =
360		get_eeprom_data(id_port, EEPROM_RESOURCE_CFG);
361
362	    ep_board[ep_boards].prod_id =
363		get_eeprom_data(id_port, EEPROM_PROD_ID);
364
365	    ep_board[ep_boards].epb_used = 0;
366#ifdef PC98
367	    ep_board[ep_boards].epb_addr =
368			(get_eeprom_data(id_port, EEPROM_ADDR_CFG) & 0x1f) * 0x100 + 0x40d0;
369#else
370	    ep_board[ep_boards].epb_addr =
371			(get_eeprom_data(id_port, EEPROM_ADDR_CFG) & 0x1f) * 0x10 + 0x200;
372
373	    if (ep_board[ep_boards].epb_addr > 0x3E0)
374		/* Board in EISA configuration mode */
375		continue;
376#endif /* PC98 */
377
378	    outb(id_port, ep_current_tag);	/* tags board */
379	    outb(id_port, ACTIVATE_ADAPTER_TO_CONFIG);
380	    ep_boards++;
381	    count++;
382	    ep_current_tag--;
383	}
384
385	ep_board[ep_boards].epb_addr = 0;
386	if (count) {
387	    printf("%d 3C5x9 board(s) on ISA found at", count);
388	    for (j = 0; ep_board[j].epb_addr; j++)
389		if (ep_board[j].epb_addr <= 0x3E0)
390		    printf(" 0x%x", ep_board[j].epb_addr);
391	    printf("\n");
392	}
393    }
394
395    /* we have two cases:
396     *
397     *  1. Device was configured with 'port ?'
398     *      In this case we search for the first unused card in list
399     *
400     *  2. Device was configured with 'port xxx'
401     *      In this case we search for the unused card with that address
402     *
403     */
404
405    if (IS_BASE == -1) { /* port? */
406	for (i = 0; ep_board[i].epb_addr && ep_board[i].epb_used; i++)
407	    ;
408	if (ep_board[i].epb_addr == 0)
409	    return 0;
410
411	IS_BASE = ep_board[i].epb_addr;
412	ep_board[i].epb_used = 1;
413
414	return &ep_board[i];
415    } else {
416	for (i = 0;
417	     ep_board[i].epb_addr && ep_board[i].epb_addr != IS_BASE;
418	     i++)
419	    ;
420
421	if (ep_board[i].epb_used || ep_board[i].epb_addr != IS_BASE)
422	    return 0;
423
424	if (inw(IS_BASE + EP_W0_EEPROM_COMMAND) & EEPROM_TST_MODE) {
425	    printf("ep%d: 3c5x9 at 0x%x in PnP mode. Disable PnP mode!\n",
426		   is->id_unit, IS_BASE);
427	}
428	ep_board[i].epb_used = 1;
429
430	return &ep_board[i];
431    }
432}
433
434/*
435 * get_e: gets a 16 bits word from the EEPROM. we must have set the window
436 * before
437 */
438u_int16_t
439get_e(sc, offset)
440    struct ep_softc *sc;
441    int offset;
442{
443    if (!eeprom_rdy(sc))
444	return (0xffff);
445    outw(BASE + EP_W0_EEPROM_COMMAND, EEPROM_CMD_RD | offset);
446    if (!eeprom_rdy(sc))
447	return (0xffff);
448    return (inw(BASE + EP_W0_EEPROM_DATA));
449}
450
451struct ep_softc *
452ep_alloc(unit, epb)
453    int	unit;
454    struct	ep_board *epb;
455{
456    struct	ep_softc *sc;
457
458    if (unit >= NEP) {
459	printf("ep: unit number (%d) too high\n", unit);
460	return NULL;
461    }
462
463    /*
464     * Allocate a storage area for us
465     */
466    if (ep_softc[unit]) {
467	printf("ep%d: unit number already allocated to another "
468	       "adaptor\n", unit);
469	return NULL;
470    }
471
472    sc = malloc(sizeof(struct ep_softc), M_DEVBUF, M_NOWAIT);
473    if (!sc) {
474	printf("ep%d: cannot malloc!\n", unit);
475	return NULL;
476    }
477    bzero(sc, sizeof(struct ep_softc));
478    ep_softc[unit] = sc;
479    sc->unit = unit;
480    sc->ep_io_addr = epb->epb_addr;
481    sc->epb = epb;
482
483    return(sc);
484}
485
486void
487ep_free(sc)
488    struct ep_softc *sc;
489{
490    ep_softc[sc->unit] = NULL;
491    free(sc, M_DEVBUF);
492    return;
493}
494
495int
496ep_isa_probe(is)
497    struct isa_device *is;
498{
499    struct ep_softc *sc;
500    struct ep_board *epb;
501    u_short k;
502
503#if NCRD > 0
504    pccard_add_driver(&ep_info);
505#endif /* NCRD > 0 */
506
507    if ((epb = ep_look_for_board_at(is)) == 0)
508	return (0);
509
510    /*
511     * Allocate a storage area for us
512     */
513    sc = ep_alloc(ep_unit, epb);
514    if (!sc)
515	return (0);
516
517    is->id_unit = ep_unit++;
518
519    /*
520     * The iobase was found and MFG_ID was 0x6d50. PROD_ID should be
521     * 0x9[0-f]50
522     */
523    GO_WINDOW(0);
524    k = sc->epb->prod_id;
525    if ((k & 0xf0ff) != (PROD_ID & 0xf0ff)) {
526	printf("ep_isa_probe: ignoring model %04x\n", k);
527	ep_free(sc);
528	return (0);
529    }
530
531    k = sc->epb->res_cfg;
532
533    k >>= 12;
534
535    /* Now we have two cases again:
536     *
537     *  1. Device was configured with 'irq?'
538     *      In this case we use irq read from the board
539     *
540     *  2. Device was configured with 'irq xxx'
541     *      In this case we set up the board to use specified interrupt
542     *
543     */
544
545    if (is->id_irq == 0) { /* irq? */
546	is->id_irq = 1 << ((k == 2) ? 9 : k);
547    }
548
549    sc->stat = 0;	/* 16 bit access */
550
551    /* By now, the adapter is already activated */
552
553    return (EP_IOSIZE);		/* 16 bytes of I/O space used. */
554}
555
556static int
557ep_isa_attach(is)
558    struct isa_device *is;
559{
560    struct ep_softc *sc = ep_softc[is->id_unit];
561    u_short config;
562    int irq;
563
564    sc->ep_connectors = 0;
565    config = inw(IS_BASE + EP_W0_CONFIG_CTRL);
566    if (config & IS_AUI) {
567	sc->ep_connectors |= AUI;
568    }
569    if (config & IS_BNC) {
570	sc->ep_connectors |= BNC;
571    }
572    if (config & IS_UTP) {
573	sc->ep_connectors |= UTP;
574    }
575    if (!(sc->ep_connectors & 7))
576	printf("no connectors!");
577    sc->ep_connector = inw(BASE + EP_W0_ADDRESS_CFG) >> ACF_CONNECTOR_BITS;
578    /*
579     * Write IRQ value to board
580     */
581
582    irq = ffs(is->id_irq) - 1;
583    if (irq == -1) {
584	printf(" invalid irq... cannot attach\n");
585	return 0;
586    }
587
588    GO_WINDOW(0);
589    SET_IRQ(BASE, irq);
590
591    ep_attach(sc);
592    return 1;
593}
594
595int
596ep_attach(sc)
597    struct ep_softc *sc;
598{
599    struct ifaddr *ifa;
600    struct ifnet *ifp = &sc->arpcom.ac_if;
601    struct sockaddr_dl *sdl;
602    u_short *p;
603    int i;
604    int attached;
605
606    sc->gone = 0;
607    attached = (ifp->if_softc != 0);
608
609    printf("ep%d: ", sc->unit);
610    /*
611     * Current media type
612     */
613    if (sc->ep_connectors & AUI) {
614	printf("aui");
615	if (sc->ep_connectors & ~AUI)
616		printf("/");
617    }
618    if (sc->ep_connectors & UTP) {
619	printf("utp");
620	if (sc->ep_connectors & BNC)
621		printf("/");
622    }
623    if (sc->ep_connectors & BNC) {
624	printf("bnc");
625    }
626
627    printf("[*%s*]", ep_conn_type[sc->ep_connector]);
628
629    /*
630     * Setup the station address
631     */
632    p = (u_short *) & sc->arpcom.ac_enaddr;
633    GO_WINDOW(2);
634    for (i = 0; i < 3; i++) {
635	p[i] = htons(sc->epb->eth_addr[i]);
636	outw(BASE + EP_W2_ADDR_0 + (i * 2), ntohs(p[i]));
637    }
638    printf(" address %6D\n", sc->arpcom.ac_enaddr, ":");
639
640    ifp->if_softc = sc;
641    ifp->if_unit = sc->unit;
642    ifp->if_name = "ep";
643    ifp->if_mtu = ETHERMTU;
644    ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
645    ifp->if_output = ether_output;
646    ifp->if_start = epstart;
647    ifp->if_ioctl = epioctl;
648    ifp->if_watchdog = epwatchdog;
649
650    if (!attached) {
651	if_attach(ifp);
652	ether_ifattach(ifp);
653    }
654
655#ifdef EP_LOCAL_STATS
656    sc->rx_no_first = sc->rx_no_mbuf =
657	sc->rx_bpf_disc = sc->rx_overrunf = sc->rx_overrunl =
658	sc->tx_underrun = 0;
659#endif
660    ep_fset(F_RX_FIRST);
661    sc->top = sc->mcur = 0;
662
663#if NBPFILTER > 0
664    if (!attached) {
665	bpfattach(ifp, DLT_EN10MB, sizeof(struct ether_header));
666    }
667#endif
668    return 0;
669}
670
671
672/*
673 * The order in here seems important. Otherwise we may not receive
674 * interrupts. ?!
675 */
676static void
677epinit(sc)
678    struct ep_softc *sc;
679{
680    register struct ifnet *ifp = &sc->arpcom.ac_if;
681    int s, i, j;
682
683    if (sc->gone)
684	return;
685
686	/*
687    if (ifp->if_addrlist == (struct ifaddr *) 0)
688	return;
689	*/
690
691    s = splimp();
692    while (inw(BASE + EP_STATUS) & S_COMMAND_IN_PROGRESS);
693
694    GO_WINDOW(0);
695    outw(BASE + EP_COMMAND, STOP_TRANSCEIVER);
696    GO_WINDOW(4);
697    outw(BASE + EP_W4_MEDIA_TYPE, DISABLE_UTP);
698    GO_WINDOW(0);
699
700    /* Disable the card */
701    outw(BASE + EP_W0_CONFIG_CTRL, 0);
702
703    /* Enable the card */
704    outw(BASE + EP_W0_CONFIG_CTRL, ENABLE_DRQ_IRQ);
705
706    GO_WINDOW(2);
707
708    /* Reload the ether_addr. */
709    for (i = 0; i < 6; i++)
710	outb(BASE + EP_W2_ADDR_0 + i, sc->arpcom.ac_enaddr[i]);
711
712    outw(BASE + EP_COMMAND, RX_RESET);
713    outw(BASE + EP_COMMAND, TX_RESET);
714    while (inw(BASE + EP_STATUS) & S_COMMAND_IN_PROGRESS);
715
716    /* Window 1 is operating window */
717    GO_WINDOW(1);
718    for (i = 0; i < 31; i++)
719	inb(BASE + EP_W1_TX_STATUS);
720
721    /* get rid of stray intr's */
722    outw(BASE + EP_COMMAND, ACK_INTR | 0xff);
723
724    outw(BASE + EP_COMMAND, SET_RD_0_MASK | S_5_INTS);
725
726    outw(BASE + EP_COMMAND, SET_INTR_MASK | S_5_INTS);
727
728    if (ifp->if_flags & IFF_PROMISC)
729	outw(BASE + EP_COMMAND, SET_RX_FILTER | FIL_INDIVIDUAL |
730	 FIL_GROUP | FIL_BRDCST | FIL_ALL);
731    else
732	outw(BASE + EP_COMMAND, SET_RX_FILTER | FIL_INDIVIDUAL |
733	 FIL_GROUP | FIL_BRDCST);
734
735     /*
736      * S.B.
737      *
738      * Now behavior was slightly changed:
739      *
740      * if any of flags link[0-2] is used and its connector is
741      * physically present the following connectors are used:
742      *
743      *   link0 - AUI * highest precedence
744      *   link1 - BNC
745      *   link2 - UTP * lowest precedence
746      *
747      * If none of them is specified then
748      * connector specified in the EEPROM is used
749      * (if present on card or AUI if not).
750      *
751      */
752
753    /* Set the xcvr. */
754    if (ifp->if_flags & IFF_LINK0 && sc->ep_connectors & AUI) {
755	i = ACF_CONNECTOR_AUI;
756    } else if (ifp->if_flags & IFF_LINK1 && sc->ep_connectors & BNC) {
757	i = ACF_CONNECTOR_BNC;
758    } else if (ifp->if_flags & IFF_LINK2 && sc->ep_connectors & UTP) {
759	i = ACF_CONNECTOR_UTP;
760    } else {
761	i = sc->ep_connector;
762    }
763    GO_WINDOW(0);
764    j = inw(BASE + EP_W0_ADDRESS_CFG) & 0x3fff;
765    outw(BASE + EP_W0_ADDRESS_CFG, j | (i << ACF_CONNECTOR_BITS));
766
767    switch(i) {
768      case ACF_CONNECTOR_UTP:
769	if (sc->ep_connectors & UTP) {
770	    GO_WINDOW(4);
771	    outw(BASE + EP_W4_MEDIA_TYPE, ENABLE_UTP);
772	}
773	break;
774      case ACF_CONNECTOR_BNC:
775	if (sc->ep_connectors & BNC) {
776	    outw(BASE + EP_COMMAND, START_TRANSCEIVER);
777	    DELAY(1000);
778	}
779	break;
780      case ACF_CONNECTOR_AUI:
781	/* nothing to do */
782	break;
783      default:
784	printf("ep%d: strange connector type in EEPROM: assuming AUI\n",
785	       sc->unit);
786	break;
787    }
788
789    outw(BASE + EP_COMMAND, RX_ENABLE);
790    outw(BASE + EP_COMMAND, TX_ENABLE);
791
792    ifp->if_flags |= IFF_RUNNING;
793    ifp->if_flags &= ~IFF_OACTIVE;	/* just in case */
794
795#ifdef EP_LOCAL_STATS
796    sc->rx_no_first = sc->rx_no_mbuf =
797	sc->rx_bpf_disc = sc->rx_overrunf = sc->rx_overrunl =
798	sc->tx_underrun = 0;
799#endif
800    ep_fset(F_RX_FIRST);
801    if (sc->top) {
802	m_freem(sc->top);
803	sc->top = sc->mcur = 0;
804    }
805    outw(BASE + EP_COMMAND, SET_RX_EARLY_THRESH | RX_INIT_EARLY_THRESH);
806    outw(BASE + EP_COMMAND, SET_TX_START_THRESH | 16);
807
808    /*
809     * Store up a bunch of mbuf's for use later. (MAX_MBS). First we free up
810     * any that we had in case we're being called from intr or somewhere
811     * else.
812     */
813
814    GO_WINDOW(1);
815    epstart(ifp);
816
817    splx(s);
818}
819
820static const char padmap[] = {0, 3, 2, 1};
821
822static void
823epstart(ifp)
824    struct ifnet *ifp;
825{
826    register struct ep_softc *sc = ifp->if_softc;
827    register u_int len;
828    register struct mbuf *m;
829    struct mbuf *top;
830    int s, pad;
831
832    if (sc->gone) {
833	return;
834    }
835
836    s = splimp();
837    while (inw(BASE + EP_STATUS) & S_COMMAND_IN_PROGRESS);
838    if (ifp->if_flags & IFF_OACTIVE) {
839	splx(s);
840	return;
841    }
842startagain:
843    /* Sneak a peek at the next packet */
844    m = ifp->if_snd.ifq_head;
845    if (m == 0) {
846	splx(s);
847	return;
848    }
849    for (len = 0, top = m; m; m = m->m_next)
850	len += m->m_len;
851
852    pad = padmap[len & 3];
853
854    /*
855     * The 3c509 automatically pads short packets to minimum ethernet length,
856     * but we drop packets that are too large. Perhaps we should truncate
857     * them instead?
858     */
859    if (len + pad > ETHER_MAX_LEN) {
860	/* packet is obviously too large: toss it */
861	++ifp->if_oerrors;
862	IF_DEQUEUE(&ifp->if_snd, m);
863	m_freem(m);
864	goto readcheck;
865    }
866    if (inw(BASE + EP_W1_FREE_TX) < len + pad + 4) {
867	/* no room in FIFO */
868	outw(BASE + EP_COMMAND, SET_TX_AVAIL_THRESH | (len + pad + 4));
869	/* make sure */
870	if (inw(BASE + EP_W1_FREE_TX) < len + pad + 4) {
871	    ifp->if_flags |= IFF_OACTIVE;
872	    splx(s);
873	    return;
874	}
875    }
876    IF_DEQUEUE(&ifp->if_snd, m);
877
878    outw(BASE + EP_W1_TX_PIO_WR_1, len);
879    outw(BASE + EP_W1_TX_PIO_WR_1, 0x0);	/* Second dword meaningless */
880
881    for (top = m; m != 0; m = m->m_next)
882	if (ep_ftst(F_ACCESS_32_BITS)) {
883	    outsl(BASE + EP_W1_TX_PIO_WR_1, mtod(m, caddr_t),
884		  m->m_len / 4);
885	    if (m->m_len & 3)
886		outsb(BASE + EP_W1_TX_PIO_WR_1,
887		      mtod(m, caddr_t) + (m->m_len & (~3)),
888		      m->m_len & 3);
889	} else {
890	    outsw(BASE + EP_W1_TX_PIO_WR_1, mtod(m, caddr_t), m->m_len / 2);
891	    if (m->m_len & 1)
892		outb(BASE + EP_W1_TX_PIO_WR_1,
893		     *(mtod(m, caddr_t) + m->m_len - 1));
894	}
895
896    while (pad--)
897	outb(BASE + EP_W1_TX_PIO_WR_1, 0);	/* Padding */
898
899#if NBPFILTER > 0
900    if (ifp->if_bpf) {
901	bpf_mtap(ifp, top);
902    }
903#endif
904
905    ifp->if_timer = 2;
906    ifp->if_opackets++;
907    m_freem(top);
908
909    /*
910     * Is another packet coming in? We don't want to overflow the tiny RX
911     * fifo.
912     */
913readcheck:
914    if (inw(BASE + EP_W1_RX_STATUS) & RX_BYTES_MASK) {
915	/*
916	 * we check if we have packets left, in that case we prepare to come
917	 * back later
918	 */
919	if (ifp->if_snd.ifq_head) {
920	    outw(BASE + EP_COMMAND, SET_TX_AVAIL_THRESH | 8);
921	}
922	splx(s);
923	return;
924    }
925    goto startagain;
926}
927
928void
929epintr(unit)
930    int unit;
931{
932    register struct ep_softc *sc = ep_softc[unit];
933
934    if (sc->gone) {
935	return;
936    }
937
938    ep_intr(sc);
939}
940
941void
942ep_intr(arg)
943    void *arg;
944{
945    struct ep_softc *sc;
946    register int status;
947    struct ifnet *ifp;
948    int x;
949
950    x = splbio();
951
952    sc = (struct ep_softc *)arg;
953
954    ifp = &sc->arpcom.ac_if;
955
956    outw(BASE + EP_COMMAND, SET_INTR_MASK); /* disable all Ints */
957
958rescan:
959
960    while ((status = inw(BASE + EP_STATUS)) & S_5_INTS) {
961
962	/* first acknowledge all interrupt sources */
963	outw(BASE + EP_COMMAND, ACK_INTR | (status & S_MASK));
964
965	if (status & (S_RX_COMPLETE | S_RX_EARLY)) {
966	    epread(sc);
967	    continue;
968	}
969	if (status & S_TX_AVAIL) {
970	    /* we need ACK */
971	    ifp->if_timer = 0;
972	    ifp->if_flags &= ~IFF_OACTIVE;
973	    GO_WINDOW(1);
974	    inw(BASE + EP_W1_FREE_TX);
975	    epstart(ifp);
976	}
977	if (status & S_CARD_FAILURE) {
978	    ifp->if_timer = 0;
979#ifdef EP_LOCAL_STATS
980	    printf("\nep%d:\n\tStatus: %x\n", sc->unit, status);
981	    GO_WINDOW(4);
982	    printf("\tFIFO Diagnostic: %x\n", inw(BASE + EP_W4_FIFO_DIAG));
983	    printf("\tStat: %x\n", sc->stat);
984	    printf("\tIpackets=%d, Opackets=%d\n",
985		ifp->if_ipackets, ifp->if_opackets);
986	    printf("\tNOF=%d, NOMB=%d, BPFD=%d, RXOF=%d, RXOL=%d, TXU=%d\n",
987		   sc->rx_no_first, sc->rx_no_mbuf, sc->rx_bpf_disc, sc->rx_overrunf,
988		   sc->rx_overrunl, sc->tx_underrun);
989#else
990
991#ifdef DIAGNOSTIC
992	    printf("ep%d: Status: %x (input buffer overflow)\n", sc->unit, status);
993#else
994	    ++ifp->if_ierrors;
995#endif
996
997#endif
998	    epinit(sc);
999	    splx(x);
1000	    return;
1001	}
1002	if (status & S_TX_COMPLETE) {
1003	    ifp->if_timer = 0;
1004	    /* we  need ACK. we do it at the end */
1005	    /*
1006	     * We need to read TX_STATUS until we get a 0 status in order to
1007	     * turn off the interrupt flag.
1008	     */
1009	    while ((status = inb(BASE + EP_W1_TX_STATUS)) & TXS_COMPLETE) {
1010		if (status & TXS_SUCCES_INTR_REQ);
1011		else if (status & (TXS_UNDERRUN | TXS_JABBER | TXS_MAX_COLLISION)) {
1012		    outw(BASE + EP_COMMAND, TX_RESET);
1013		    if (status & TXS_UNDERRUN) {
1014#ifdef EP_LOCAL_STATS
1015			sc->tx_underrun++;
1016#endif
1017		    } else {
1018			if (status & TXS_JABBER);
1019			else	/* TXS_MAX_COLLISION - we shouldn't get here */
1020			    ++ifp->if_collisions;
1021		    }
1022		    ++ifp->if_oerrors;
1023		    outw(BASE + EP_COMMAND, TX_ENABLE);
1024		    /*
1025		     * To have a tx_avail_int but giving the chance to the
1026		     * Reception
1027		     */
1028		    if (ifp->if_snd.ifq_head) {
1029			outw(BASE + EP_COMMAND, SET_TX_AVAIL_THRESH | 8);
1030		    }
1031		}
1032		outb(BASE + EP_W1_TX_STATUS, 0x0);	/* pops up the next
1033							 * status */
1034	    }			/* while */
1035	    ifp->if_flags &= ~IFF_OACTIVE;
1036	    GO_WINDOW(1);
1037	    inw(BASE + EP_W1_FREE_TX);
1038	    epstart(ifp);
1039	}			/* end TX_COMPLETE */
1040    }
1041
1042    outw(BASE + EP_COMMAND, C_INTR_LATCH);	/* ACK int Latch */
1043
1044    if ((status = inw(BASE + EP_STATUS)) & S_5_INTS)
1045	goto rescan;
1046
1047    /* re-enable Ints */
1048    outw(BASE + EP_COMMAND, SET_INTR_MASK | S_5_INTS);
1049
1050    splx(x);
1051}
1052
1053static void
1054epread(sc)
1055    register struct ep_softc *sc;
1056{
1057    struct ether_header *eh;
1058    struct mbuf *top, *mcur, *m;
1059    struct ifnet *ifp;
1060    int lenthisone;
1061
1062    short rx_fifo2, status;
1063    register short delta;
1064    register short rx_fifo;
1065
1066    ifp = &sc->arpcom.ac_if;
1067    status = inw(BASE + EP_W1_RX_STATUS);
1068
1069read_again:
1070
1071    if (status & ERR_RX) {
1072	++ifp->if_ierrors;
1073	if (status & ERR_RX_OVERRUN) {
1074	    /*
1075	     * we can think the rx latency is actually greather than we
1076	     * expect
1077	     */
1078#ifdef EP_LOCAL_STATS
1079	    if (ep_ftst(F_RX_FIRST))
1080		sc->rx_overrunf++;
1081	    else
1082		sc->rx_overrunl++;
1083#endif
1084	}
1085	goto out;
1086    }
1087    rx_fifo = rx_fifo2 = status & RX_BYTES_MASK;
1088
1089    if (ep_ftst(F_RX_FIRST)) {
1090	MGETHDR(m, M_DONTWAIT, MT_DATA);
1091	if (!m)
1092	    goto out;
1093	if (rx_fifo >= MINCLSIZE)
1094	    MCLGET(m, M_DONTWAIT);
1095	sc->top = sc->mcur = top = m;
1096#define EROUND  ((sizeof(struct ether_header) + 3) & ~3)
1097#define EOFF    (EROUND - sizeof(struct ether_header))
1098	top->m_data += EOFF;
1099
1100	/* Read what should be the header. */
1101	insw(BASE + EP_W1_RX_PIO_RD_1,
1102	     mtod(top, caddr_t), sizeof(struct ether_header) / 2);
1103	top->m_len = sizeof(struct ether_header);
1104	rx_fifo -= sizeof(struct ether_header);
1105	sc->cur_len = rx_fifo2;
1106    } else {
1107	/* come here if we didn't have a complete packet last time */
1108	top = sc->top;
1109	m = sc->mcur;
1110	sc->cur_len += rx_fifo2;
1111    }
1112
1113    /* Reads what is left in the RX FIFO */
1114    while (rx_fifo > 0) {
1115	lenthisone = min(rx_fifo, M_TRAILINGSPACE(m));
1116	if (lenthisone == 0) {	/* no room in this one */
1117	    mcur = m;
1118	    MGET(m, M_DONTWAIT, MT_DATA);
1119	    if (!m)
1120		goto out;
1121	    if (rx_fifo >= MINCLSIZE)
1122		MCLGET(m, M_DONTWAIT);
1123	    m->m_len = 0;
1124	    mcur->m_next = m;
1125	    lenthisone = min(rx_fifo, M_TRAILINGSPACE(m));
1126	}
1127	if (ep_ftst(F_ACCESS_32_BITS)) { /* default for EISA configured cards*/
1128	    insl(BASE + EP_W1_RX_PIO_RD_1, mtod(m, caddr_t) + m->m_len,
1129		 lenthisone / 4);
1130	    m->m_len += (lenthisone & ~3);
1131	    if (lenthisone & 3)
1132		insb(BASE + EP_W1_RX_PIO_RD_1,
1133		     mtod(m, caddr_t) + m->m_len,
1134		     lenthisone & 3);
1135	    m->m_len += (lenthisone & 3);
1136	} else {
1137	    insw(BASE + EP_W1_RX_PIO_RD_1, mtod(m, caddr_t) + m->m_len,
1138		 lenthisone / 2);
1139	    m->m_len += lenthisone;
1140	    if (lenthisone & 1)
1141		*(mtod(m, caddr_t) + m->m_len - 1) = inb(BASE + EP_W1_RX_PIO_RD_1);
1142	}
1143	rx_fifo -= lenthisone;
1144    }
1145
1146    if (status & ERR_RX_INCOMPLETE) {	/* we haven't received the complete
1147					 * packet */
1148	sc->mcur = m;
1149#ifdef EP_LOCAL_STATS
1150	sc->rx_no_first++;	/* to know how often we come here */
1151#endif
1152	ep_frst(F_RX_FIRST);
1153	if (!((status = inw(BASE + EP_W1_RX_STATUS)) & ERR_RX_INCOMPLETE)) {
1154	    /* we see if by now, the packet has completly arrived */
1155	    goto read_again;
1156	}
1157	outw(BASE + EP_COMMAND, SET_RX_EARLY_THRESH | RX_NEXT_EARLY_THRESH);
1158	return;
1159    }
1160all_pkt:
1161    outw(BASE + EP_COMMAND, RX_DISCARD_TOP_PACK);
1162    ++ifp->if_ipackets;
1163    ep_fset(F_RX_FIRST);
1164    top->m_pkthdr.rcvif = &sc->arpcom.ac_if;
1165    top->m_pkthdr.len = sc->cur_len;
1166
1167#if NBPFILTER > 0
1168    if (ifp->if_bpf) {
1169	bpf_mtap(ifp, top);
1170
1171	/*
1172	 * Note that the interface cannot be in promiscuous mode if there are
1173	 * no BPF listeners.  And if we are in promiscuous mode, we have to
1174	 * check if this packet is really ours.
1175	 */
1176	eh = mtod(top, struct ether_header *);
1177	if ((ifp->if_flags & IFF_PROMISC) &&
1178	    (eh->ether_dhost[0] & 1) == 0 &&
1179	    bcmp(eh->ether_dhost, sc->arpcom.ac_enaddr,
1180		 sizeof(eh->ether_dhost)) != 0 &&
1181	    bcmp(eh->ether_dhost, etherbroadcastaddr,
1182		 sizeof(eh->ether_dhost)) != 0) {
1183	    if (sc->top) {
1184		m_freem(sc->top);
1185		sc->top = 0;
1186	    }
1187	    ep_fset(F_RX_FIRST);
1188#ifdef EP_LOCAL_STATS
1189	    sc->rx_bpf_disc++;
1190#endif
1191	    while (inw(BASE + EP_STATUS) & S_COMMAND_IN_PROGRESS);
1192	    outw(BASE + EP_COMMAND, SET_RX_EARLY_THRESH | RX_INIT_EARLY_THRESH);
1193	    return;
1194	}
1195    }
1196#endif
1197
1198    eh = mtod(top, struct ether_header *);
1199    m_adj(top, sizeof(struct ether_header));
1200    ether_input(ifp, eh, top);
1201    sc->top = 0;
1202    while (inw(BASE + EP_STATUS) & S_COMMAND_IN_PROGRESS);
1203    outw(BASE + EP_COMMAND, SET_RX_EARLY_THRESH | RX_INIT_EARLY_THRESH);
1204    return;
1205
1206out:
1207    outw(BASE + EP_COMMAND, RX_DISCARD_TOP_PACK);
1208    if (sc->top) {
1209	m_freem(sc->top);
1210	sc->top = 0;
1211#ifdef EP_LOCAL_STATS
1212	sc->rx_no_mbuf++;
1213#endif
1214    }
1215    ep_fset(F_RX_FIRST);
1216    while (inw(BASE + EP_STATUS) & S_COMMAND_IN_PROGRESS);
1217    outw(BASE + EP_COMMAND, SET_RX_EARLY_THRESH | RX_INIT_EARLY_THRESH);
1218}
1219
1220/*
1221 * Look familiar?
1222 */
1223static int
1224epioctl(ifp, cmd, data)
1225    register struct ifnet *ifp;
1226    int cmd;
1227    caddr_t data;
1228{
1229    register struct ifaddr *ifa = (struct ifaddr *) data;
1230    struct ep_softc *sc = ifp->if_softc;
1231    struct ifreq *ifr = (struct ifreq *) data;
1232    int s, error = 0;
1233
1234    s = splimp();
1235
1236    switch (cmd) {
1237      case SIOCSIFADDR:
1238	ifp->if_flags |= IFF_UP;
1239
1240	/* netifs are BUSY when UP */
1241
1242	switch (ifa->ifa_addr->sa_family) {
1243#ifdef INET
1244	  case AF_INET:
1245	    epinit(sc);	/* before arpwhohas */
1246	    arp_ifinit((struct arpcom *)ifp, ifa);
1247	    break;
1248#endif
1249#ifdef IPX
1250	  case AF_IPX:
1251	    {
1252		register struct ipx_addr *ina = &(IA_SIPX(ifa)->sipx_addr);
1253
1254		if (ipx_nullhost(*ina))
1255		    ina->x_host =
1256			*(union ipx_host *) (sc->arpcom.ac_enaddr);
1257		else {
1258		    ifp->if_flags &= ~IFF_RUNNING;
1259		    bcopy((caddr_t) ina->x_host.c_host,
1260			  (caddr_t) sc->arpcom.ac_enaddr,
1261			  sizeof(sc->arpcom.ac_enaddr));
1262		}
1263		epinit(sc);
1264		break;
1265	    }
1266#endif
1267#ifdef NS
1268	  case AF_NS:
1269	    {
1270		register struct ns_addr *ina = &(IA_SNS(ifa)->sns_addr);
1271
1272		if (ns_nullhost(*ina))
1273		    ina->x_host =
1274			*(union ns_host *) (sc->arpcom.ac_enaddr);
1275		else {
1276		    ifp->if_flags &= ~IFF_RUNNING;
1277		    bcopy((caddr_t) ina->x_host.c_host,
1278			  (caddr_t) sc->arpcom.ac_enaddr,
1279			  sizeof(sc->arpcom.ac_enaddr));
1280		}
1281		epinit(sc);
1282		break;
1283	    }
1284#endif
1285	  default:
1286	    epinit(sc);
1287	    break;
1288	}
1289	break;
1290      case SIOCGIFADDR:
1291	{
1292	  struct sockaddr *sa;
1293
1294	  sa = (struct sockaddr *) & ifr->ifr_data;
1295	  bcopy((caddr_t) sc->arpcom.ac_enaddr,
1296		(caddr_t) sa->sa_data, ETHER_ADDR_LEN);
1297	}
1298	break;
1299      case SIOCSIFFLAGS:
1300
1301	if ((ifp->if_flags & IFF_UP) == 0 && ifp->if_flags & IFF_RUNNING) {
1302	    ifp->if_flags &= ~IFF_RUNNING;
1303	    epstop(sc);
1304	    break;
1305	} else {
1306	    /* reinitialize card on any parameter change */
1307	    epinit(sc);
1308	    break;
1309	}
1310
1311	/* NOTREACHED */
1312	break;
1313#ifdef notdef
1314      case SIOCGHWADDR:
1315	bcopy((caddr_t) sc->sc_addr, (caddr_t) & ifr->ifr_data,
1316	      sizeof(sc->sc_addr));
1317	break;
1318#endif
1319	case SIOCSIFMTU:
1320
1321		/*
1322		 * Set the interface MTU.
1323		 */
1324		if (ifr->ifr_mtu > ETHERMTU) {
1325			error = EINVAL;
1326		} else {
1327			ifp->if_mtu = ifr->ifr_mtu;
1328		}
1329		break;
1330	case SIOCADDMULTI:
1331	case SIOCDELMULTI:
1332	    /* Now this driver has no support for programmable
1333	     * multicast filters. If some day it will gain this
1334	     * support this part of code must be extended.
1335	     */
1336	    error = 0;
1337	    break;
1338      default:
1339		error = EINVAL;
1340    }
1341
1342    splx(s);
1343
1344    return (error);
1345}
1346
1347static void
1348epwatchdog(ifp)
1349    struct ifnet *ifp;
1350{
1351    struct ep_softc *sc = ifp->if_softc;
1352
1353    /*
1354    printf("ep: watchdog\n");
1355
1356    log(LOG_ERR, "ep%d: watchdog\n", ifp->if_unit);
1357    ifp->if_oerrors++;
1358    */
1359
1360    if (sc->gone) {
1361	return;
1362    }
1363
1364    ifp->if_flags &= ~IFF_OACTIVE;
1365    epstart(ifp);
1366    ep_intr(ifp->if_softc);
1367}
1368
1369static void
1370epstop(sc)
1371    struct ep_softc *sc;
1372{
1373    if (sc->gone) {
1374	return;
1375    }
1376
1377    outw(BASE + EP_COMMAND, RX_DISABLE);
1378    outw(BASE + EP_COMMAND, RX_DISCARD_TOP_PACK);
1379    while (inw(BASE + EP_STATUS) & S_COMMAND_IN_PROGRESS);
1380    outw(BASE + EP_COMMAND, TX_DISABLE);
1381    outw(BASE + EP_COMMAND, STOP_TRANSCEIVER);
1382    outw(BASE + EP_COMMAND, RX_RESET);
1383    outw(BASE + EP_COMMAND, TX_RESET);
1384    while (inw(BASE + EP_STATUS) & S_COMMAND_IN_PROGRESS);
1385    outw(BASE + EP_COMMAND, C_INTR_LATCH);
1386    outw(BASE + EP_COMMAND, SET_RD_0_MASK);
1387    outw(BASE + EP_COMMAND, SET_INTR_MASK);
1388    outw(BASE + EP_COMMAND, SET_RX_FILTER);
1389}
1390
1391
1392#if 0
1393static int
1394send_ID_sequence(port)
1395    int port;
1396{
1397    int cx, al;
1398
1399    for (al = 0xff, cx = 0; cx < 255; cx++) {
1400	outb(port, al);
1401	al <<= 1;
1402	if (al & 0x100)
1403	    al ^= 0xcf;
1404    }
1405    return (1);
1406}
1407#endif
1408
1409
1410/*
1411 * We get eeprom data from the id_port given an offset into the eeprom.
1412 * Basically; after the ID_sequence is sent to all of the cards; they enter
1413 * the ID_CMD state where they will accept command requests. 0x80-0xbf loads
1414 * the eeprom data.  We then read the port 16 times and with every read; the
1415 * cards check for contention (ie: if one card writes a 0 bit and another
1416 * writes a 1 bit then the host sees a 0. At the end of the cycle; each card
1417 * compares the data on the bus; if there is a difference then that card goes
1418 * into ID_WAIT state again). In the meantime; one bit of data is returned in
1419 * the AX register which is conveniently returned to us by inb().  Hence; we
1420 * read 16 times getting one bit of data with each read.
1421 */
1422static int
1423get_eeprom_data(id_port, offset)
1424    int id_port;
1425    int offset;
1426{
1427    int i, data = 0;
1428    outb(id_port, 0x80 + offset);
1429    DELAY(1000);
1430    for (i = 0; i < 16; i++)
1431	data = (data << 1) | (inw(id_port) & 1);
1432    return (data);
1433}
1434
1435#endif				/* NEP > 0 */
1436