if_plip.c revision 51646 
1/*-
2 * Copyright (c) 1997 Poul-Henning Kamp
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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 *	From Id: lpt.c,v 1.55.2.1 1996/11/12 09:08:38 phk Exp
27 * $FreeBSD: head/sys/dev/ppbus/if_plip.c 51646 1999-09-25 12:06:01Z phk $
28 */
29
30/*
31 * Parallel port TCP/IP interfaces added.  I looked at the driver from
32 * MACH but this is a complete rewrite, and btw. incompatible, and it
33 * should perform better too.  I have never run the MACH driver though.
34 *
35 * This driver sends two bytes (0x08, 0x00) in front of each packet,
36 * to allow us to distinguish another format later.
37 *
38 * Now added an Linux/Crynwr compatibility mode which is enabled using
39 * IF_LINK0 - Tim Wilkinson.
40 *
41 * TODO:
42 *    Make HDLC/PPP mode, use IF_LLC1 to enable.
43 *
44 * Connect the two computers using a Laplink parallel cable to use this
45 * feature:
46 *
47 *      +----------------------------------------+
48 * 	|A-name	A-End	B-End	Descr.	Port/Bit |
49 *      +----------------------------------------+
50 *	|DATA0	2	15	Data	0/0x01   |
51 *	|-ERROR	15	2	   	1/0x08   |
52 *      +----------------------------------------+
53 *	|DATA1	3	13	Data	0/0x02	 |
54 *	|+SLCT	13	3	   	1/0x10   |
55 *      +----------------------------------------+
56 *	|DATA2	4	12	Data	0/0x04   |
57 *	|+PE	12	4	   	1/0x20   |
58 *      +----------------------------------------+
59 *	|DATA3	5	10	Strobe	0/0x08   |
60 *	|-ACK	10	5	   	1/0x40   |
61 *      +----------------------------------------+
62 *	|DATA4	6	11	Data	0/0x10   |
63 *	|BUSY	11	6	   	1/~0x80  |
64 *      +----------------------------------------+
65 *	|GND	18-25	18-25	GND	-        |
66 *      +----------------------------------------+
67 *
68 * Expect transfer-rates up to 75 kbyte/sec.
69 *
70 * If GCC could correctly grok
71 *	register int port asm("edx")
72 * the code would be cleaner
73 *
74 * Poul-Henning Kamp <phk@freebsd.org>
75 */
76
77/*
78 * Update for ppbus, PLIP support only - Nicolas Souchu
79 */
80
81#include <sys/param.h>
82#include <sys/systm.h>
83#include <sys/mbuf.h>
84#include <sys/socket.h>
85#include <sys/sockio.h>
86#include <sys/kernel.h>
87#include <sys/malloc.h>
88
89#include <net/if.h>
90#include <net/if_types.h>
91#include <net/netisr.h>
92
93#include <netinet/in.h>
94#include <netinet/in_var.h>
95
96#include <net/bpf.h>
97
98#include <dev/ppbus/ppbconf.h>
99
100#include "opt_plip.h"
101
102#ifndef LPMTU			/* MTU for the lp# interfaces */
103#define	LPMTU	1500
104#endif
105
106#ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
107#define	LPMAXSPIN1	8000   /* Spinning for remote intr to happen */
108#endif
109
110#ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
111#define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
112#endif
113
114#ifndef LPMAXERRS		/* Max errors before !RUNNING */
115#define	LPMAXERRS	100
116#endif
117
118#define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
119#define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
120#define MLPIPHDRLEN	CLPIPHDRLEN
121
122#define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
123#define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
124#if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
125#define MLPIPHDRLEN	LPIPHDRLEN
126#endif
127
128#define	LPIPTBLSIZE	256	/* Size of octet translation table */
129
130#define lprintf		if (lptflag) printf
131
132#ifdef PLIP_DEBUG
133static int volatile lptflag = 1;
134#else
135static int volatile lptflag = 0;
136#endif
137
138struct lpt_softc {
139	unsigned short lp_unit;
140
141	struct ppb_device lp_dev;
142
143	struct  ifnet	sc_if;
144	u_char		*sc_ifbuf;
145	int		sc_iferrs;
146};
147
148static int	nlp = 0;
149#define MAXPLIP	8			/* XXX not much better! */
150static struct lpt_softc *lpdata[MAXPLIP];
151
152
153/* Tables for the lp# interface */
154static u_char *txmith;
155#define txmitl (txmith+(1*LPIPTBLSIZE))
156#define trecvh (txmith+(2*LPIPTBLSIZE))
157#define trecvl (txmith+(3*LPIPTBLSIZE))
158
159static u_char *ctxmith;
160#define ctxmitl (ctxmith+(1*LPIPTBLSIZE))
161#define ctrecvh (ctxmith+(2*LPIPTBLSIZE))
162#define ctrecvl (ctxmith+(3*LPIPTBLSIZE))
163
164/* Functions for the lp# interface */
165static struct ppb_device	*lpprobe(struct ppb_data *);
166static int			lpattach(struct ppb_device *);
167
168static int lpinittables(void);
169static int lpioctl(struct ifnet *, u_long, caddr_t);
170static int lpoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
171	struct rtentry *);
172static void lpintr(int);
173
174/*
175 * Make ourselves visible as a ppbus driver
176 */
177
178static struct ppb_driver lpdriver = {
179    lpprobe, lpattach, "lp"
180};
181DATA_SET(ppbdriver_set, lpdriver);
182
183
184/*
185 * lpprobe()
186 */
187static struct ppb_device *
188lpprobe(struct ppb_data *ppb)
189{
190	struct lpt_softc *lp;
191
192	/* if we haven't interrupts, the probe fails */
193	if (!ppb->ppb_link->id_irq) {
194		printf("plip: not an interrupt driven port, failed.\n");
195		return (0);
196	}
197
198	lp = (struct lpt_softc *) malloc(sizeof(struct lpt_softc),
199							M_TEMP, M_NOWAIT);
200	if (!lp) {
201		printf("lp: cannot malloc!\n");
202		return (0);
203	}
204	bzero(lp, sizeof(struct lpt_softc));
205
206	lpdata[nlp] = lp;
207
208	/*
209	 * lp dependent initialisation.
210	 */
211	lp->lp_unit = nlp;
212
213	if (bootverbose)
214		printf("plip: irq %d\n", ppb->ppb_link->id_irq);
215
216	/*
217	 * ppbus dependent initialisation.
218	 */
219	lp->lp_dev.id_unit = lp->lp_unit;
220	lp->lp_dev.name = lpdriver.name;
221	lp->lp_dev.ppb = ppb;
222	lp->lp_dev.intr = lpintr;
223
224	/* Ok, go to next device on next probe */
225	nlp ++;
226
227	return (&lp->lp_dev);
228}
229
230static int
231lpattach (struct ppb_device *dev)
232{
233	int unit = dev->id_unit;
234	struct lpt_softc *sc = lpdata[unit];
235	struct ifnet *ifp = &sc->sc_if;
236
237	/*
238	 * Report ourselves
239	 */
240	printf("plip%d: <PLIP network interface> on ppbus %d\n",
241	       dev->id_unit, dev->ppb->ppb_link->adapter_unit);
242
243	ifp->if_softc = sc;
244	ifp->if_name = "lp";
245	ifp->if_unit = unit;
246	ifp->if_mtu = LPMTU;
247	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
248	ifp->if_ioctl = lpioctl;
249	ifp->if_output = lpoutput;
250	ifp->if_type = IFT_PARA;
251	ifp->if_hdrlen = 0;
252	ifp->if_addrlen = 0;
253	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
254	if_attach(ifp);
255
256	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
257
258	return (1);
259}
260/*
261 * Build the translation tables for the LPIP (BSD unix) protocol.
262 * We don't want to calculate these nasties in our tight loop, so we
263 * precalculate them when we initialize.
264 */
265static int
266lpinittables (void)
267{
268    int i;
269
270    if (!txmith)
271	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
272
273    if (!txmith)
274	return 1;
275
276    if (!ctxmith)
277	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
278
279    if (!ctxmith)
280	return 1;
281
282    for (i=0; i < LPIPTBLSIZE; i++) {
283	ctxmith[i] = (i & 0xF0) >> 4;
284	ctxmitl[i] = 0x10 | (i & 0x0F);
285	ctrecvh[i] = (i & 0x78) << 1;
286	ctrecvl[i] = (i & 0x78) >> 3;
287    }
288
289    for (i=0; i < LPIPTBLSIZE; i++) {
290	txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
291	txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
292	trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
293	trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
294    }
295
296    return 0;
297}
298
299/*
300 * Process an ioctl request.
301 */
302
303static int
304lpioctl (struct ifnet *ifp, u_long cmd, caddr_t data)
305{
306    struct lpt_softc *sc = lpdata[ifp->if_unit];
307    struct ifaddr *ifa = (struct ifaddr *)data;
308    struct ifreq *ifr = (struct ifreq *)data;
309    u_char *ptr;
310    int error;
311
312    switch (cmd) {
313
314    case SIOCSIFDSTADDR:
315    case SIOCAIFADDR:
316    case SIOCSIFADDR:
317	if (ifa->ifa_addr->sa_family != AF_INET)
318	    return EAFNOSUPPORT;
319
320	ifp->if_flags |= IFF_UP;
321	/* FALLTHROUGH */
322    case SIOCSIFFLAGS:
323	if ((!(ifp->if_flags & IFF_UP)) && (ifp->if_flags & IFF_RUNNING)) {
324
325	    ppb_wctr(&sc->lp_dev, 0x00);
326	    ifp->if_flags &= ~IFF_RUNNING;
327
328	    /* IFF_UP is not set, try to release the bus anyway */
329	    ppb_release_bus(&sc->lp_dev);
330	    break;
331	}
332	if (((ifp->if_flags & IFF_UP)) && (!(ifp->if_flags & IFF_RUNNING))) {
333
334	    /* XXX
335	     * Should the request be interruptible?
336	     */
337	    if ((error = ppb_request_bus(&sc->lp_dev, PPB_WAIT|PPB_INTR)))
338		return (error);
339
340	    /* Now IFF_UP means that we own the bus */
341
342	    ppb_set_mode(&sc->lp_dev, PPB_COMPATIBLE);
343
344	    if (lpinittables()) {
345		ppb_release_bus(&sc->lp_dev);
346		return ENOBUFS;
347	    }
348
349	    sc->sc_ifbuf = malloc(sc->sc_if.if_mtu + MLPIPHDRLEN,
350				  M_DEVBUF, M_WAITOK);
351	    if (!sc->sc_ifbuf) {
352		ppb_release_bus(&sc->lp_dev);
353		return ENOBUFS;
354	    }
355
356	    ppb_wctr(&sc->lp_dev, IRQENABLE);
357	    ifp->if_flags |= IFF_RUNNING;
358	}
359	break;
360
361    case SIOCSIFMTU:
362	ptr = sc->sc_ifbuf;
363	sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
364	if (!sc->sc_ifbuf) {
365	    sc->sc_ifbuf = ptr;
366	    return ENOBUFS;
367	}
368	if (ptr)
369	    free(ptr,M_DEVBUF);
370	sc->sc_if.if_mtu = ifr->ifr_mtu;
371	break;
372
373    case SIOCGIFMTU:
374	ifr->ifr_mtu = sc->sc_if.if_mtu;
375	break;
376
377    case SIOCADDMULTI:
378    case SIOCDELMULTI:
379	if (ifr == 0) {
380	    return EAFNOSUPPORT;		/* XXX */
381	}
382	switch (ifr->ifr_addr.sa_family) {
383
384	case AF_INET:
385	    break;
386
387	default:
388	    return EAFNOSUPPORT;
389	}
390	break;
391
392    case SIOCGIFMEDIA:
393	/*
394	 * No ifmedia support at this stage; maybe use it
395	 * in future for eg. protocol selection.
396	 */
397	return EINVAL;
398
399    default:
400	lprintf("LP:ioctl(0x%lx)\n", cmd);
401	return EINVAL;
402    }
403    return 0;
404}
405
406static __inline int
407clpoutbyte (u_char byte, int spin, struct ppb_device *dev)
408{
409	ppb_wdtr(dev, ctxmitl[byte]);
410	while (ppb_rstr(dev) & CLPIP_SHAKE)
411		if (--spin == 0) {
412			return 1;
413		}
414	ppb_wdtr(dev, ctxmith[byte]);
415	while (!(ppb_rstr(dev) & CLPIP_SHAKE))
416		if (--spin == 0) {
417			return 1;
418		}
419	return 0;
420}
421
422static __inline int
423clpinbyte (int spin, struct ppb_device *dev)
424{
425	u_char c, cl;
426
427	while((ppb_rstr(dev) & CLPIP_SHAKE))
428	    if(!--spin) {
429		return -1;
430	    }
431	cl = ppb_rstr(dev);
432	ppb_wdtr(dev, 0x10);
433
434	while(!(ppb_rstr(dev) & CLPIP_SHAKE))
435	    if(!--spin) {
436		return -1;
437	    }
438	c = ppb_rstr(dev);
439	ppb_wdtr(dev, 0x00);
440
441	return (ctrecvl[cl] | ctrecvh[c]);
442}
443
444static void
445lptap(struct ifnet *ifp, struct mbuf *m)
446{
447	/*
448	 * Send a packet through bpf. We need to prepend the address family
449	 * as a four byte field. Cons up a dummy header to pacify bpf. This
450	 * is safe because bpf will only read from the mbuf (i.e., it won't
451	 * try to free it or keep a pointer to it).
452	 */
453	u_int32_t af = AF_INET;
454	struct mbuf m0;
455
456	m0.m_next = m;
457	m0.m_len = sizeof(u_int32_t);
458	m0.m_data = (char *)&af;
459	bpf_mtap(ifp, &m0);
460}
461
462static void
463lpintr (int unit)
464{
465	struct   lpt_softc *sc = lpdata[unit];
466	int len, s, j;
467	u_char *bp;
468	u_char c, cl;
469	struct mbuf *top;
470
471	s = splhigh();
472
473	if (sc->sc_if.if_flags & IFF_LINK0) {
474
475	    /* Ack. the request */
476	    ppb_wdtr(&sc->lp_dev, 0x01);
477
478	    /* Get the packet length */
479	    j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
480	    if (j == -1)
481		goto err;
482	    len = j;
483	    j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
484	    if (j == -1)
485		goto err;
486	    len = len + (j << 8);
487	    if (len > sc->sc_if.if_mtu + MLPIPHDRLEN)
488		goto err;
489
490	    bp  = sc->sc_ifbuf;
491
492	    while (len--) {
493	        j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
494	        if (j == -1) {
495		    goto err;
496	        }
497	        *bp++ = j;
498	    }
499	    /* Get and ignore checksum */
500	    j = clpinbyte(LPMAXSPIN2, &sc->lp_dev);
501	    if (j == -1) {
502	        goto err;
503	    }
504
505	    len = bp - sc->sc_ifbuf;
506	    if (len <= CLPIPHDRLEN)
507	        goto err;
508
509	    sc->sc_iferrs = 0;
510
511	    if (IF_QFULL(&ipintrq)) {
512	        lprintf("DROP");
513	        IF_DROP(&ipintrq);
514		goto done;
515	    }
516	    len -= CLPIPHDRLEN;
517	    sc->sc_if.if_ipackets++;
518	    sc->sc_if.if_ibytes += len;
519	    top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, &sc->sc_if, 0);
520	    if (top) {
521		if (sc->sc_if.if_bpf)
522		    lptap(&sc->sc_if, top);
523	        IF_ENQUEUE(&ipintrq, top);
524	        schednetisr(NETISR_IP);
525	    }
526	    goto done;
527	}
528	while ((ppb_rstr(&sc->lp_dev) & LPIP_SHAKE)) {
529	    len = sc->sc_if.if_mtu + LPIPHDRLEN;
530	    bp  = sc->sc_ifbuf;
531	    while (len--) {
532
533		cl = ppb_rstr(&sc->lp_dev);
534		ppb_wdtr(&sc->lp_dev, 8);
535
536		j = LPMAXSPIN2;
537		while((ppb_rstr(&sc->lp_dev) & LPIP_SHAKE))
538		    if(!--j) goto err;
539
540		c = ppb_rstr(&sc->lp_dev);
541		ppb_wdtr(&sc->lp_dev, 0);
542
543		*bp++= trecvh[cl] | trecvl[c];
544
545		j = LPMAXSPIN2;
546		while (!((cl=ppb_rstr(&sc->lp_dev)) & LPIP_SHAKE)) {
547		    if (cl != c &&
548			(((cl = ppb_rstr(&sc->lp_dev)) ^ 0xb8) & 0xf8) ==
549			  (c & 0xf8))
550			goto end;
551		    if (!--j) goto err;
552		}
553	    }
554
555	end:
556	    len = bp - sc->sc_ifbuf;
557	    if (len <= LPIPHDRLEN)
558		goto err;
559
560	    sc->sc_iferrs = 0;
561
562	    if (IF_QFULL(&ipintrq)) {
563		lprintf("DROP");
564		IF_DROP(&ipintrq);
565		goto done;
566	    }
567	    len -= LPIPHDRLEN;
568	    sc->sc_if.if_ipackets++;
569	    sc->sc_if.if_ibytes += len;
570	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
571	    if (top) {
572		if (sc->sc_if.if_bpf)
573		    lptap(&sc->sc_if, top);
574		IF_ENQUEUE(&ipintrq, top);
575		schednetisr(NETISR_IP);
576	    }
577	}
578	goto done;
579
580    err:
581	ppb_wdtr(&sc->lp_dev, 0);
582	lprintf("R");
583	sc->sc_if.if_ierrors++;
584	sc->sc_iferrs++;
585
586	/*
587	 * We are not able to send receive anything for now,
588	 * so stop wasting our time
589	 */
590	if (sc->sc_iferrs > LPMAXERRS) {
591	    printf("lp%d: Too many errors, Going off-line.\n", unit);
592	    ppb_wctr(&sc->lp_dev, 0x00);
593	    sc->sc_if.if_flags &= ~IFF_RUNNING;
594	    sc->sc_iferrs=0;
595	}
596
597    done:
598	splx(s);
599	return;
600}
601
602static __inline int
603lpoutbyte (u_char byte, int spin, struct ppb_device *dev)
604{
605    ppb_wdtr(dev, txmith[byte]);
606    while (!(ppb_rstr(dev) & LPIP_SHAKE))
607	if (--spin == 0)
608		return 1;
609    ppb_wdtr(dev, txmitl[byte]);
610    while (ppb_rstr(dev) & LPIP_SHAKE)
611	if (--spin == 0)
612		return 1;
613    return 0;
614}
615
616static int
617lpoutput (struct ifnet *ifp, struct mbuf *m,
618	  struct sockaddr *dst, struct rtentry *rt)
619{
620    struct lpt_softc *sc = lpdata[ifp->if_unit];
621    int s, err;
622    struct mbuf *mm;
623    u_char *cp = "\0\0";
624    u_char chksum = 0;
625    int count = 0;
626    int i, len, spin;
627
628    /* We need a sensible value if we abort */
629    cp++;
630    ifp->if_flags |= IFF_RUNNING;
631
632    err = 1;			/* assume we're aborting because of an error */
633
634    s = splhigh();
635
636    /* Suspend (on laptops) or receive-errors might have taken us offline */
637    ppb_wctr(&sc->lp_dev, IRQENABLE);
638
639    if (ifp->if_flags & IFF_LINK0) {
640
641	if (!(ppb_rstr(&sc->lp_dev) & CLPIP_SHAKE)) {
642	    lprintf("&");
643	    lpintr(ifp->if_unit);
644	}
645
646	/* Alert other end to pending packet */
647	spin = LPMAXSPIN1;
648	ppb_wdtr(&sc->lp_dev, 0x08);
649	while ((ppb_rstr(&sc->lp_dev) & 0x08) == 0)
650		if (--spin == 0) {
651			goto nend;
652		}
653
654	/* Calculate length of packet, then send that */
655
656	count += 14;		/* Ethernet header len */
657
658	mm = m;
659	for (mm = m; mm; mm = mm->m_next) {
660		count += mm->m_len;
661	}
662	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, &sc->lp_dev))
663		goto nend;
664	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, &sc->lp_dev))
665		goto nend;
666
667	/* Send dummy ethernet header */
668	for (i = 0; i < 12; i++) {
669		if (clpoutbyte(i, LPMAXSPIN1, &sc->lp_dev))
670			goto nend;
671		chksum += i;
672	}
673
674	if (clpoutbyte(0x08, LPMAXSPIN1, &sc->lp_dev))
675		goto nend;
676	if (clpoutbyte(0x00, LPMAXSPIN1, &sc->lp_dev))
677		goto nend;
678	chksum += 0x08 + 0x00;		/* Add into checksum */
679
680	mm = m;
681	do {
682		cp = mtod(mm, u_char *);
683		len = mm->m_len;
684		while (len--) {
685			chksum += *cp;
686			if (clpoutbyte(*cp++, LPMAXSPIN2, &sc->lp_dev))
687				goto nend;
688		}
689	} while ((mm = mm->m_next));
690
691	/* Send checksum */
692	if (clpoutbyte(chksum, LPMAXSPIN2, &sc->lp_dev))
693		goto nend;
694
695	/* Go quiescent */
696	ppb_wdtr(&sc->lp_dev, 0);
697
698	err = 0;			/* No errors */
699
700	nend:
701	if (err)  {				/* if we didn't timeout... */
702		ifp->if_oerrors++;
703		lprintf("X");
704	} else {
705		ifp->if_opackets++;
706		ifp->if_obytes += m->m_pkthdr.len;
707		if (ifp->if_bpf)
708		    lptap(ifp, m);
709	}
710
711	m_freem(m);
712
713	if (!(ppb_rstr(&sc->lp_dev) & CLPIP_SHAKE)) {
714		lprintf("^");
715		lpintr(ifp->if_unit);
716	}
717	(void) splx(s);
718	return 0;
719    }
720
721    if (ppb_rstr(&sc->lp_dev) & LPIP_SHAKE) {
722        lprintf("&");
723        lpintr(ifp->if_unit);
724    }
725
726    if (lpoutbyte(0x08, LPMAXSPIN1, &sc->lp_dev))
727        goto end;
728    if (lpoutbyte(0x00, LPMAXSPIN2, &sc->lp_dev))
729        goto end;
730
731    mm = m;
732    do {
733        cp = mtod(mm,u_char *);
734	len = mm->m_len;
735        while (len--)
736	    if (lpoutbyte(*cp++, LPMAXSPIN2, &sc->lp_dev))
737	        goto end;
738    } while ((mm = mm->m_next));
739
740    err = 0;				/* no errors were encountered */
741
742    end:
743    --cp;
744    ppb_wdtr(&sc->lp_dev, txmitl[*cp] ^ 0x17);
745
746    if (err)  {				/* if we didn't timeout... */
747	ifp->if_oerrors++;
748        lprintf("X");
749    } else {
750	ifp->if_opackets++;
751	ifp->if_obytes += m->m_pkthdr.len;
752	if (ifp->if_bpf)
753	    lptap(ifp, m);
754    }
755
756    m_freem(m);
757
758    if (ppb_rstr(&sc->lp_dev) & LPIP_SHAKE) {
759	lprintf("^");
760	lpintr(ifp->if_unit);
761    }
762
763    (void) splx(s);
764    return 0;
765}
766