xref: /dflybsd-src/sys/dev/netif/plip/if_plip.c (revision c6cf4f8f1ebc9e3fe2a8c566f08adfc86122c7bf)
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: src/sys/dev/ppbus/if_plip.c,v 1.19.2.1 2000/05/24 00:20:57 n_hibma Exp $
28  * $DragonFly: src/sys/dev/netif/plip/if_plip.c,v 1.10 2005/02/19 17:59:38 joerg Exp $
29  */
30 
31 /*
32  * Parallel port TCP/IP interfaces added.  I looked at the driver from
33  * MACH but this is a complete rewrite, and btw. incompatible, and it
34  * should perform better too.  I have never run the MACH driver though.
35  *
36  * This driver sends two bytes (0x08, 0x00) in front of each packet,
37  * to allow us to distinguish another format later.
38  *
39  * Now added an Linux/Crynwr compatibility mode which is enabled using
40  * IF_LINK0 - Tim Wilkinson.
41  *
42  * TODO:
43  *    Make HDLC/PPP mode, use IF_LLC1 to enable.
44  *
45  * Connect the two computers using a Laplink parallel cable to use this
46  * feature:
47  *
48  *      +----------------------------------------+
49  * 	|A-name	A-End	B-End	Descr.	Port/Bit |
50  *      +----------------------------------------+
51  *	|DATA0	2	15	Data	0/0x01   |
52  *	|-ERROR	15	2	   	1/0x08   |
53  *      +----------------------------------------+
54  *	|DATA1	3	13	Data	0/0x02	 |
55  *	|+SLCT	13	3	   	1/0x10   |
56  *      +----------------------------------------+
57  *	|DATA2	4	12	Data	0/0x04   |
58  *	|+PE	12	4	   	1/0x20   |
59  *      +----------------------------------------+
60  *	|DATA3	5	10	Strobe	0/0x08   |
61  *	|-ACK	10	5	   	1/0x40   |
62  *      +----------------------------------------+
63  *	|DATA4	6	11	Data	0/0x10   |
64  *	|BUSY	11	6	   	1/~0x80  |
65  *      +----------------------------------------+
66  *	|GND	18-25	18-25	GND	-        |
67  *      +----------------------------------------+
68  *
69  * Expect transfer-rates up to 75 kbyte/sec.
70  *
71  * If GCC could correctly grok
72  *	register int port asm("edx")
73  * the code would be cleaner
74  *
75  * Poul-Henning Kamp <phk@freebsd.org>
76  */
77 
78 /*
79  * Update for ppbus, PLIP support only - Nicolas Souchu
80  */
81 
82 #include "opt_plip.h"
83 
84 #include <sys/param.h>
85 #include <sys/systm.h>
86 #include <sys/module.h>
87 #include <sys/bus.h>
88 #include <sys/mbuf.h>
89 #include <sys/socket.h>
90 #include <sys/sockio.h>
91 #include <sys/kernel.h>
92 #include <sys/malloc.h>
93 
94 #include <machine/clock.h>
95 #include <machine/bus.h>
96 #include <machine/resource.h>
97 #include <sys/rman.h>
98 
99 #include <net/if.h>
100 #include <net/ifq_var.h>
101 #include <net/if_types.h>
102 #include <net/netisr.h>
103 
104 #include <netinet/in.h>
105 #include <netinet/in_var.h>
106 
107 #include <net/bpf.h>
108 
109 #include <bus/ppbus/ppbconf.h>
110 #include "ppbus_if.h"
111 #include <bus/ppbus/ppbio.h>
112 
113 #ifndef LPMTU			/* MTU for the lp# interfaces */
114 #define	LPMTU	1500
115 #endif
116 
117 #ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
118 #define	LPMAXSPIN1	8000   /* Spinning for remote intr to happen */
119 #endif
120 
121 #ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
122 #define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
123 #endif
124 
125 #ifndef LPMAXERRS		/* Max errors before !RUNNING */
126 #define	LPMAXERRS	100
127 #endif
128 
129 #define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
130 #define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
131 #define MLPIPHDRLEN	CLPIPHDRLEN
132 
133 #define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
134 #define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
135 #if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
136 #define MLPIPHDRLEN	LPIPHDRLEN
137 #endif
138 
139 #define	LPIPTBLSIZE	256	/* Size of octet translation table */
140 
141 #define lprintf		if (lptflag) printf
142 
143 #ifdef PLIP_DEBUG
144 static int volatile lptflag = 1;
145 #else
146 static int volatile lptflag = 0;
147 #endif
148 
149 struct lp_data {
150 	unsigned short lp_unit;
151 
152 	struct  ifnet	sc_if;
153 	u_char		*sc_ifbuf;
154 	int		sc_iferrs;
155 
156 	struct resource *res_irq;
157 };
158 
159 /* Tables for the lp# interface */
160 static u_char *txmith;
161 #define txmitl (txmith+(1*LPIPTBLSIZE))
162 #define trecvh (txmith+(2*LPIPTBLSIZE))
163 #define trecvl (txmith+(3*LPIPTBLSIZE))
164 
165 static u_char *ctxmith;
166 #define ctxmitl (ctxmith+(1*LPIPTBLSIZE))
167 #define ctrecvh (ctxmith+(2*LPIPTBLSIZE))
168 #define ctrecvl (ctxmith+(3*LPIPTBLSIZE))
169 
170 /* Functions for the lp# interface */
171 static int lpinittables(void);
172 static int lpioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
173 static int lpoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
174 	struct rtentry *);
175 static void lp_intr(void *);
176 
177 #define DEVTOSOFTC(dev) \
178 	((struct lp_data *)device_get_softc(dev))
179 #define UNITOSOFTC(unit) \
180 	((struct lp_data *)devclass_get_softc(lp_devclass, (unit)))
181 #define UNITODEVICE(unit) \
182 	(devclass_get_device(lp_devclass, (unit)))
183 
184 static devclass_t lp_devclass;
185 
186 static void
187 lp_identify(driver_t *driver, device_t parent)
188 {
189 
190 	BUS_ADD_CHILD(parent, 0, "plip", 0);
191 }
192 /*
193  * lpprobe()
194  */
195 static int
196 lp_probe(device_t dev)
197 {
198 	device_t ppbus = device_get_parent(dev);
199 	struct lp_data *lp;
200 	int zero = 0;
201 	uintptr_t irq;
202 
203 	lp = DEVTOSOFTC(dev);
204 	bzero(lp, sizeof(struct lp_data));
205 
206 	/* retrieve the ppbus irq */
207 	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
208 
209 	/* if we haven't interrupts, the probe fails */
210 	if (irq == -1) {
211 		device_printf(dev, "not an interrupt driven port, failed.\n");
212 		return (ENXIO);
213 	}
214 
215 	/* reserve the interrupt resource, expecting irq is available to continue */
216 	lp->res_irq = bus_alloc_resource(dev, SYS_RES_IRQ, &zero, irq, irq, 1,
217 					 RF_SHAREABLE);
218 	if (lp->res_irq == 0) {
219 		device_printf(dev, "cannot reserve interrupt, failed.\n");
220 		return (ENXIO);
221 	}
222 
223 	/*
224 	 * lp dependent initialisation.
225 	 */
226 	lp->lp_unit = device_get_unit(dev);
227 
228 	device_set_desc(dev, "PLIP network interface");
229 
230 	return (0);
231 }
232 
233 static int
234 lp_attach (device_t dev)
235 {
236 	struct lp_data *lp = DEVTOSOFTC(dev);
237 	struct ifnet *ifp = &lp->sc_if;
238 
239 	ifp->if_softc = lp;
240 	if_initname(ifp, "lp", device_get_unit(dev));
241 	ifp->if_mtu = LPMTU;
242 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
243 	ifp->if_ioctl = lpioctl;
244 	ifp->if_output = lpoutput;
245 	ifp->if_type = IFT_PARA;
246 	ifp->if_hdrlen = 0;
247 	ifp->if_addrlen = 0;
248 	ifq_set_maxlen(&ifp->if_snd, IFQ_MAXLEN);
249 	if_attach(ifp);
250 
251 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
252 
253 	return (0);
254 }
255 /*
256  * Build the translation tables for the LPIP (BSD unix) protocol.
257  * We don't want to calculate these nasties in our tight loop, so we
258  * precalculate them when we initialize.
259  */
260 static int
261 lpinittables (void)
262 {
263     int i;
264 
265     if (!txmith)
266 	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_WAITOK);
267 
268     if (!ctxmith)
269 	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_WAITOK);
270 
271     for (i=0; i < LPIPTBLSIZE; i++) {
272 	ctxmith[i] = (i & 0xF0) >> 4;
273 	ctxmitl[i] = 0x10 | (i & 0x0F);
274 	ctrecvh[i] = (i & 0x78) << 1;
275 	ctrecvl[i] = (i & 0x78) >> 3;
276     }
277 
278     for (i=0; i < LPIPTBLSIZE; i++) {
279 	txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
280 	txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
281 	trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
282 	trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
283     }
284 
285     return 0;
286 }
287 
288 /*
289  * Process an ioctl request.
290  */
291 
292 static int
293 lpioctl (struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
294 {
295     device_t dev = UNITODEVICE(ifp->if_dunit);
296     device_t ppbus = device_get_parent(dev);
297     struct lp_data *sc = DEVTOSOFTC(dev);
298     struct ifaddr *ifa = (struct ifaddr *)data;
299     struct ifreq *ifr = (struct ifreq *)data;
300     u_char *ptr;
301     void *ih;
302     int error;
303 
304     switch (cmd) {
305 
306     case SIOCSIFDSTADDR:
307     case SIOCAIFADDR:
308     case SIOCSIFADDR:
309 	if (ifa->ifa_addr->sa_family != AF_INET)
310 	    return EAFNOSUPPORT;
311 
312 	ifp->if_flags |= IFF_UP;
313 	/* FALLTHROUGH */
314     case SIOCSIFFLAGS:
315 	if ((!(ifp->if_flags & IFF_UP)) && (ifp->if_flags & IFF_RUNNING)) {
316 
317 	    ppb_wctr(ppbus, 0x00);
318 	    ifp->if_flags &= ~IFF_RUNNING;
319 
320 	    /* IFF_UP is not set, try to release the bus anyway */
321 	    ppb_release_bus(ppbus, dev);
322 	    break;
323 	}
324 	if (((ifp->if_flags & IFF_UP)) && (!(ifp->if_flags & IFF_RUNNING))) {
325 
326 	    /* XXX
327 	     * Should the request be interruptible?
328 	     */
329 	    if ((error = ppb_request_bus(ppbus, dev, PPB_WAIT|PPB_INTR)))
330 		return (error);
331 
332 	    /* Now IFF_UP means that we own the bus */
333 
334 	    ppb_set_mode(ppbus, PPB_COMPATIBLE);
335 
336 	    if (lpinittables()) {
337 		ppb_release_bus(ppbus, dev);
338 		return ENOBUFS;
339 	    }
340 
341 	    sc->sc_ifbuf = malloc(sc->sc_if.if_mtu + MLPIPHDRLEN,
342 				  M_DEVBUF, M_WAITOK);
343 	    if (!sc->sc_ifbuf) {
344 		ppb_release_bus(ppbus, dev);
345 		return ENOBUFS;
346 	    }
347 
348 	    /* attach our interrupt handler, later detached when the bus is released */
349 	    if ((error = BUS_SETUP_INTR(ppbus, dev, sc->res_irq,
350 					INTR_TYPE_NET, lp_intr, dev, &ih))) {
351 		ppb_release_bus(ppbus, dev);
352 		return (error);
353 	    }
354 
355 	    ppb_wctr(ppbus, IRQENABLE);
356 	    ifp->if_flags |= IFF_RUNNING;
357 	}
358 	break;
359 
360     case SIOCSIFMTU:
361 	ptr = sc->sc_ifbuf;
362 	sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF, M_WAITOK);
363 	if (ptr)
364 	    free(ptr,M_DEVBUF);
365 	sc->sc_if.if_mtu = ifr->ifr_mtu;
366 	break;
367 
368     case SIOCGIFMTU:
369 	ifr->ifr_mtu = sc->sc_if.if_mtu;
370 	break;
371 
372     case SIOCADDMULTI:
373     case SIOCDELMULTI:
374 	if (ifr == 0) {
375 	    return EAFNOSUPPORT;		/* XXX */
376 	}
377 	switch (ifr->ifr_addr.sa_family) {
378 
379 	case AF_INET:
380 	    break;
381 
382 	default:
383 	    return EAFNOSUPPORT;
384 	}
385 	break;
386 
387     case SIOCGIFMEDIA:
388 	/*
389 	 * No ifmedia support at this stage; maybe use it
390 	 * in future for eg. protocol selection.
391 	 */
392 	return EINVAL;
393 
394     default:
395 	lprintf("LP:ioctl(0x%lx)\n", cmd);
396 	return EINVAL;
397     }
398     return 0;
399 }
400 
401 static __inline int
402 clpoutbyte (u_char byte, int spin, device_t ppbus)
403 {
404 	ppb_wdtr(ppbus, ctxmitl[byte]);
405 	while (ppb_rstr(ppbus) & CLPIP_SHAKE)
406 		if (--spin == 0) {
407 			return 1;
408 		}
409 	ppb_wdtr(ppbus, ctxmith[byte]);
410 	while (!(ppb_rstr(ppbus) & CLPIP_SHAKE))
411 		if (--spin == 0) {
412 			return 1;
413 		}
414 	return 0;
415 }
416 
417 static __inline int
418 clpinbyte (int spin, device_t ppbus)
419 {
420 	u_char c, cl;
421 
422 	while((ppb_rstr(ppbus) & CLPIP_SHAKE))
423 	    if(!--spin) {
424 		return -1;
425 	    }
426 	cl = ppb_rstr(ppbus);
427 	ppb_wdtr(ppbus, 0x10);
428 
429 	while(!(ppb_rstr(ppbus) & CLPIP_SHAKE))
430 	    if(!--spin) {
431 		return -1;
432 	    }
433 	c = ppb_rstr(ppbus);
434 	ppb_wdtr(ppbus, 0x00);
435 
436 	return (ctrecvl[cl] | ctrecvh[c]);
437 }
438 
439 static void
440 lptap(struct ifnet *ifp, struct mbuf *m)
441 {
442 	/*
443 	 * We need to prepend the address family as a four byte field.
444 	 */
445 	static const uint32_t af = AF_INET;
446 
447 	if (ifp->if_bpf)
448 		bpf_ptap(ifp->if_bpf, m, &af, sizeof(af));
449 }
450 
451 static void
452 lp_intr (void *arg)
453 {
454 	device_t dev = (device_t)arg;
455         device_t ppbus = device_get_parent(dev);
456 	struct lp_data *sc = DEVTOSOFTC(dev);
457 	int len, s, j;
458 	u_char *bp;
459 	u_char c, cl;
460 	struct mbuf *top;
461 
462 	s = splhigh();
463 
464 	if (sc->sc_if.if_flags & IFF_LINK0) {
465 
466 	    /* Ack. the request */
467 	    ppb_wdtr(ppbus, 0x01);
468 
469 	    /* Get the packet length */
470 	    j = clpinbyte(LPMAXSPIN2, ppbus);
471 	    if (j == -1)
472 		goto err;
473 	    len = j;
474 	    j = clpinbyte(LPMAXSPIN2, ppbus);
475 	    if (j == -1)
476 		goto err;
477 	    len = len + (j << 8);
478 	    if (len > sc->sc_if.if_mtu + MLPIPHDRLEN)
479 		goto err;
480 
481 	    bp  = sc->sc_ifbuf;
482 
483 	    while (len--) {
484 	        j = clpinbyte(LPMAXSPIN2, ppbus);
485 	        if (j == -1) {
486 		    goto err;
487 	        }
488 	        *bp++ = j;
489 	    }
490 	    /* Get and ignore checksum */
491 	    j = clpinbyte(LPMAXSPIN2, ppbus);
492 	    if (j == -1) {
493 	        goto err;
494 	    }
495 
496 	    len = bp - sc->sc_ifbuf;
497 	    if (len <= CLPIPHDRLEN)
498 	        goto err;
499 
500 	    sc->sc_iferrs = 0;
501 
502 	    len -= CLPIPHDRLEN;
503 	    sc->sc_if.if_ipackets++;
504 	    sc->sc_if.if_ibytes += len;
505 	    top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, &sc->sc_if, 0);
506 	    if (top) {
507 		if (sc->sc_if.if_bpf)
508 		    lptap(&sc->sc_if, top);
509 		netisr_queue(NETISR_IP, top);
510 	    }
511 	    goto done;
512 	}
513 	while ((ppb_rstr(ppbus) & LPIP_SHAKE)) {
514 	    len = sc->sc_if.if_mtu + LPIPHDRLEN;
515 	    bp  = sc->sc_ifbuf;
516 	    while (len--) {
517 
518 		cl = ppb_rstr(ppbus);
519 		ppb_wdtr(ppbus, 8);
520 
521 		j = LPMAXSPIN2;
522 		while((ppb_rstr(ppbus) & LPIP_SHAKE))
523 		    if(!--j) goto err;
524 
525 		c = ppb_rstr(ppbus);
526 		ppb_wdtr(ppbus, 0);
527 
528 		*bp++= trecvh[cl] | trecvl[c];
529 
530 		j = LPMAXSPIN2;
531 		while (!((cl=ppb_rstr(ppbus)) & LPIP_SHAKE)) {
532 		    if (cl != c &&
533 			(((cl = ppb_rstr(ppbus)) ^ 0xb8) & 0xf8) ==
534 			  (c & 0xf8))
535 			goto end;
536 		    if (!--j) goto err;
537 		}
538 	    }
539 
540 	end:
541 	    len = bp - sc->sc_ifbuf;
542 	    if (len <= LPIPHDRLEN)
543 		goto err;
544 
545 	    sc->sc_iferrs = 0;
546 
547 	    len -= LPIPHDRLEN;
548 	    sc->sc_if.if_ipackets++;
549 	    sc->sc_if.if_ibytes += len;
550 	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
551 	    if (top) {
552 		if (sc->sc_if.if_bpf)
553 		    lptap(&sc->sc_if, top);
554 		netisr_queue(NETISR_IP, top);
555 	    }
556 	}
557 	goto done;
558 
559     err:
560 	ppb_wdtr(ppbus, 0);
561 	lprintf("R");
562 	sc->sc_if.if_ierrors++;
563 	sc->sc_iferrs++;
564 
565 	/*
566 	 * We are not able to send receive anything for now,
567 	 * so stop wasting our time
568 	 */
569 	if (sc->sc_iferrs > LPMAXERRS) {
570 	    printf("lp%d: Too many errors, Going off-line.\n", device_get_unit(dev));
571 	    ppb_wctr(ppbus, 0x00);
572 	    sc->sc_if.if_flags &= ~IFF_RUNNING;
573 	    sc->sc_iferrs=0;
574 	}
575 
576     done:
577 	splx(s);
578 	return;
579 }
580 
581 static __inline int
582 lpoutbyte (u_char byte, int spin, device_t ppbus)
583 {
584     ppb_wdtr(ppbus, txmith[byte]);
585     while (!(ppb_rstr(ppbus) & LPIP_SHAKE))
586 	if (--spin == 0)
587 		return 1;
588     ppb_wdtr(ppbus, txmitl[byte]);
589     while (ppb_rstr(ppbus) & LPIP_SHAKE)
590 	if (--spin == 0)
591 		return 1;
592     return 0;
593 }
594 
595 static int
596 lpoutput (struct ifnet *ifp, struct mbuf *m,
597 	  struct sockaddr *dst, struct rtentry *rt)
598 {
599     device_t dev = UNITODEVICE(ifp->if_dunit);
600     device_t ppbus = device_get_parent(dev);
601     int s, err;
602     struct mbuf *mm;
603     u_char *cp = "\0\0";
604     u_char chksum = 0;
605     int count = 0;
606     int i, len, spin;
607 
608     /* We need a sensible value if we abort */
609     cp++;
610     ifp->if_flags |= IFF_RUNNING;
611 
612     err = 1;			/* assume we're aborting because of an error */
613 
614     s = splhigh();
615 
616     /* Suspend (on laptops) or receive-errors might have taken us offline */
617     ppb_wctr(ppbus, IRQENABLE);
618 
619     if (ifp->if_flags & IFF_LINK0) {
620 
621 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
622 	    lprintf("&");
623 	    lp_intr(dev);
624 	}
625 
626 	/* Alert other end to pending packet */
627 	spin = LPMAXSPIN1;
628 	ppb_wdtr(ppbus, 0x08);
629 	while ((ppb_rstr(ppbus) & 0x08) == 0)
630 		if (--spin == 0) {
631 			goto nend;
632 		}
633 
634 	/* Calculate length of packet, then send that */
635 
636 	count += 14;		/* Ethernet header len */
637 
638 	mm = m;
639 	for (mm = m; mm; mm = mm->m_next) {
640 		count += mm->m_len;
641 	}
642 	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
643 		goto nend;
644 	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
645 		goto nend;
646 
647 	/* Send dummy ethernet header */
648 	for (i = 0; i < 12; i++) {
649 		if (clpoutbyte(i, LPMAXSPIN1, ppbus))
650 			goto nend;
651 		chksum += i;
652 	}
653 
654 	if (clpoutbyte(0x08, LPMAXSPIN1, ppbus))
655 		goto nend;
656 	if (clpoutbyte(0x00, LPMAXSPIN1, ppbus))
657 		goto nend;
658 	chksum += 0x08 + 0x00;		/* Add into checksum */
659 
660 	mm = m;
661 	do {
662 		cp = mtod(mm, u_char *);
663 		len = mm->m_len;
664 		while (len--) {
665 			chksum += *cp;
666 			if (clpoutbyte(*cp++, LPMAXSPIN2, ppbus))
667 				goto nend;
668 		}
669 	} while ((mm = mm->m_next));
670 
671 	/* Send checksum */
672 	if (clpoutbyte(chksum, LPMAXSPIN2, ppbus))
673 		goto nend;
674 
675 	/* Go quiescent */
676 	ppb_wdtr(ppbus, 0);
677 
678 	err = 0;			/* No errors */
679 
680 	nend:
681 	if (err)  {				/* if we didn't timeout... */
682 		ifp->if_oerrors++;
683 		lprintf("X");
684 	} else {
685 		ifp->if_opackets++;
686 		ifp->if_obytes += m->m_pkthdr.len;
687 		if (ifp->if_bpf)
688 		    lptap(ifp, m);
689 	}
690 
691 	m_freem(m);
692 
693 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
694 		lprintf("^");
695 		lp_intr(dev);
696 	}
697 	(void) splx(s);
698 	return 0;
699     }
700 
701     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
702         lprintf("&");
703         lp_intr(dev);
704     }
705 
706     if (lpoutbyte(0x08, LPMAXSPIN1, ppbus))
707         goto end;
708     if (lpoutbyte(0x00, LPMAXSPIN2, ppbus))
709         goto end;
710 
711     mm = m;
712     do {
713         cp = mtod(mm,u_char *);
714 	len = mm->m_len;
715         while (len--)
716 	    if (lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
717 	        goto end;
718     } while ((mm = mm->m_next));
719 
720     err = 0;				/* no errors were encountered */
721 
722     end:
723     --cp;
724     ppb_wdtr(ppbus, txmitl[*cp] ^ 0x17);
725 
726     if (err)  {				/* if we didn't timeout... */
727 	ifp->if_oerrors++;
728         lprintf("X");
729     } else {
730 	ifp->if_opackets++;
731 	ifp->if_obytes += m->m_pkthdr.len;
732 	if (ifp->if_bpf)
733 	    lptap(ifp, m);
734     }
735 
736     m_freem(m);
737 
738     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
739 	lprintf("^");
740 	lp_intr(dev);
741     }
742 
743     (void) splx(s);
744     return 0;
745 }
746 
747 static device_method_t lp_methods[] = {
748   	/* device interface */
749 	DEVMETHOD(device_identify,	lp_identify),
750 	DEVMETHOD(device_probe,		lp_probe),
751 	DEVMETHOD(device_attach,	lp_attach),
752 
753 	{ 0, 0 }
754 };
755 
756 static driver_t lp_driver = {
757   "plip",
758   lp_methods,
759   sizeof(struct lp_data),
760 };
761 
762 DECLARE_DUMMY_MODULE(if_plip);
763 DRIVER_MODULE(if_plip, ppbus, lp_driver, lp_devclass, 0, 0);
764 
765