xref: /freebsd/sys/dev/ppbus/if_plip.c (revision 2357939bc239bd5334a169b62313806178dd8f30)
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  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 /*
33  * Parallel port TCP/IP interfaces added.  I looked at the driver from
34  * MACH but this is a complete rewrite, and btw. incompatible, and it
35  * should perform better too.  I have never run the MACH driver though.
36  *
37  * This driver sends two bytes (0x08, 0x00) in front of each packet,
38  * to allow us to distinguish another format later.
39  *
40  * Now added a Linux/Crynwr compatibility mode which is enabled using
41  * IF_LINK0 - Tim Wilkinson.
42  *
43  * TODO:
44  *    Make HDLC/PPP mode, use IF_LLC1 to enable.
45  *
46  * Connect the two computers using a Laplink parallel cable to use this
47  * feature:
48  *
49  *      +----------------------------------------+
50  * 	|A-name	A-End	B-End	Descr.	Port/Bit |
51  *      +----------------------------------------+
52  *	|DATA0	2	15	Data	0/0x01   |
53  *	|-ERROR	15	2	   	1/0x08   |
54  *      +----------------------------------------+
55  *	|DATA1	3	13	Data	0/0x02	 |
56  *	|+SLCT	13	3	   	1/0x10   |
57  *      +----------------------------------------+
58  *	|DATA2	4	12	Data	0/0x04   |
59  *	|+PE	12	4	   	1/0x20   |
60  *      +----------------------------------------+
61  *	|DATA3	5	10	Strobe	0/0x08   |
62  *	|-ACK	10	5	   	1/0x40   |
63  *      +----------------------------------------+
64  *	|DATA4	6	11	Data	0/0x10   |
65  *	|BUSY	11	6	   	1/~0x80  |
66  *      +----------------------------------------+
67  *	|GND	18-25	18-25	GND	-        |
68  *      +----------------------------------------+
69  *
70  * Expect transfer-rates up to 75 kbyte/sec.
71  *
72  * If GCC could correctly grok
73  *	register int port asm("edx")
74  * the code would be cleaner
75  *
76  * Poul-Henning Kamp <phk@freebsd.org>
77  */
78 
79 /*
80  * Update for ppbus, PLIP support only - Nicolas Souchu
81  */
82 
83 #include "opt_plip.h"
84 
85 #include <sys/param.h>
86 #include <sys/systm.h>
87 #include <sys/module.h>
88 #include <sys/bus.h>
89 #include <sys/mbuf.h>
90 #include <sys/socket.h>
91 #include <sys/sockio.h>
92 #include <sys/kernel.h>
93 #include <sys/malloc.h>
94 
95 #include <machine/bus.h>
96 #include <machine/resource.h>
97 #include <sys/rman.h>
98 
99 #include <net/if.h>
100 #include <net/if_types.h>
101 #include <net/netisr.h>
102 
103 #include <netinet/in.h>
104 #include <netinet/in_var.h>
105 
106 #include <net/bpf.h>
107 
108 #include <dev/ppbus/ppbconf.h>
109 #include "ppbus_if.h"
110 #include <dev/ppbus/ppbio.h>
111 
112 #ifndef LPMTU			/* MTU for the lp# interfaces */
113 #define	LPMTU	1500
114 #endif
115 
116 #ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
117 #define	LPMAXSPIN1	8000   /* Spinning for remote intr to happen */
118 #endif
119 
120 #ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
121 #define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
122 #endif
123 
124 #ifndef LPMAXERRS		/* Max errors before !RUNNING */
125 #define	LPMAXERRS	100
126 #endif
127 
128 #define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
129 #define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
130 #define MLPIPHDRLEN	CLPIPHDRLEN
131 
132 #define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
133 #define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
134 #if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
135 #define MLPIPHDRLEN	LPIPHDRLEN
136 #endif
137 
138 #define	LPIPTBLSIZE	256	/* Size of octet translation table */
139 
140 #define lprintf		if (lptflag) printf
141 
142 #ifdef PLIP_DEBUG
143 static int volatile lptflag = 1;
144 #else
145 static int volatile lptflag = 0;
146 #endif
147 
148 struct lp_data {
149 	struct  ifnet	sc_if;
150 	u_char		*sc_ifbuf;
151 	int		sc_iferrs;
152 
153 	struct resource *res_irq;
154 };
155 
156 /* Tables for the lp# interface */
157 static u_char *txmith;
158 #define txmitl (txmith+(1*LPIPTBLSIZE))
159 #define trecvh (txmith+(2*LPIPTBLSIZE))
160 #define trecvl (txmith+(3*LPIPTBLSIZE))
161 
162 static u_char *ctxmith;
163 #define ctxmitl (ctxmith+(1*LPIPTBLSIZE))
164 #define ctrecvh (ctxmith+(2*LPIPTBLSIZE))
165 #define ctrecvl (ctxmith+(3*LPIPTBLSIZE))
166 
167 /* Functions for the lp# interface */
168 static int lpinittables(void);
169 static int lpioctl(struct ifnet *, u_long, caddr_t);
170 static int lpoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
171 	struct rtentry *);
172 static void lp_intr(void *);
173 
174 #define DEVTOSOFTC(dev) \
175 	((struct lp_data *)device_get_softc(dev))
176 #define UNITOSOFTC(unit) \
177 	((struct lp_data *)devclass_get_softc(lp_devclass, (unit)))
178 #define UNITODEVICE(unit) \
179 	(devclass_get_device(lp_devclass, (unit)))
180 
181 static devclass_t lp_devclass;
182 
183 static void
184 lp_identify(driver_t *driver, device_t parent)
185 {
186 	device_t dev;
187 
188 	dev = device_find_child(parent, "plip", 0);
189 	if (!dev)
190 		BUS_ADD_CHILD(parent, 0, "plip", -1);
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 
227 	device_set_desc(dev, "PLIP network interface");
228 
229 	return (0);
230 }
231 
232 static int
233 lp_attach (device_t dev)
234 {
235 	struct lp_data *lp = DEVTOSOFTC(dev);
236 	struct ifnet *ifp = &lp->sc_if;
237 
238 	ifp->if_softc = lp;
239 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
240 	ifp->if_mtu = LPMTU;
241 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
242 	ifp->if_ioctl = lpioctl;
243 	ifp->if_output = lpoutput;
244 	ifp->if_type = IFT_PARA;
245 	ifp->if_hdrlen = 0;
246 	ifp->if_addrlen = 0;
247 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
248 	if_attach(ifp);
249 
250 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
251 
252 	return (0);
253 }
254 /*
255  * Build the translation tables for the LPIP (BSD unix) protocol.
256  * We don't want to calculate these nasties in our tight loop, so we
257  * precalculate them when we initialize.
258  */
259 static int
260 lpinittables (void)
261 {
262     int i;
263 
264     if (!txmith)
265 	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
266 
267     if (!txmith)
268 	return 1;
269 
270     if (!ctxmith)
271 	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
272 
273     if (!ctxmith)
274 	return 1;
275 
276     for (i=0; i < LPIPTBLSIZE; i++) {
277 	ctxmith[i] = (i & 0xF0) >> 4;
278 	ctxmitl[i] = 0x10 | (i & 0x0F);
279 	ctrecvh[i] = (i & 0x78) << 1;
280 	ctrecvl[i] = (i & 0x78) >> 3;
281     }
282 
283     for (i=0; i < LPIPTBLSIZE; i++) {
284 	txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
285 	txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
286 	trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
287 	trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
288     }
289 
290     return 0;
291 }
292 
293 /*
294  * Process an ioctl request.
295  */
296 
297 static int
298 lpioctl (struct ifnet *ifp, u_long cmd, caddr_t data)
299 {
300     device_t dev = UNITODEVICE(ifp->if_dunit);
301     device_t ppbus = device_get_parent(dev);
302     struct lp_data *sc = DEVTOSOFTC(dev);
303     struct ifaddr *ifa = (struct ifaddr *)data;
304     struct ifreq *ifr = (struct ifreq *)data;
305     u_char *ptr;
306     void *ih;
307     int error;
308 
309     switch (cmd) {
310 
311     case SIOCSIFDSTADDR:
312     case SIOCAIFADDR:
313     case SIOCSIFADDR:
314 	if (ifa->ifa_addr->sa_family != AF_INET)
315 	    return EAFNOSUPPORT;
316 
317 	ifp->if_flags |= IFF_UP;
318 	/* FALLTHROUGH */
319     case SIOCSIFFLAGS:
320 	if ((!(ifp->if_flags & IFF_UP)) && (ifp->if_flags & IFF_RUNNING)) {
321 
322 	    ppb_wctr(ppbus, 0x00);
323 	    ifp->if_flags &= ~IFF_RUNNING;
324 
325 	    /* IFF_UP is not set, try to release the bus anyway */
326 	    ppb_release_bus(ppbus, dev);
327 	    break;
328 	}
329 	if (((ifp->if_flags & IFF_UP)) && (!(ifp->if_flags & IFF_RUNNING))) {
330 
331 	    /* XXX
332 	     * Should the request be interruptible?
333 	     */
334 	    if ((error = ppb_request_bus(ppbus, dev, PPB_WAIT|PPB_INTR)))
335 		return (error);
336 
337 	    /* Now IFF_UP means that we own the bus */
338 
339 	    ppb_set_mode(ppbus, PPB_COMPATIBLE);
340 
341 	    if (lpinittables()) {
342 		ppb_release_bus(ppbus, dev);
343 		return ENOBUFS;
344 	    }
345 
346 	    sc->sc_ifbuf = malloc(sc->sc_if.if_mtu + MLPIPHDRLEN,
347 				  M_DEVBUF, M_WAITOK);
348 	    if (!sc->sc_ifbuf) {
349 		ppb_release_bus(ppbus, dev);
350 		return ENOBUFS;
351 	    }
352 
353 	    /* attach our interrupt handler, later detached when the bus is released */
354 	    if ((error = BUS_SETUP_INTR(ppbus, dev, sc->res_irq,
355 					INTR_TYPE_NET, lp_intr, dev, &ih))) {
356 		ppb_release_bus(ppbus, dev);
357 		return (error);
358 	    }
359 
360 	    ppb_wctr(ppbus, IRQENABLE);
361 	    ifp->if_flags |= IFF_RUNNING;
362 	}
363 	break;
364 
365     case SIOCSIFMTU:
366 	ptr = sc->sc_ifbuf;
367 	sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
368 	if (!sc->sc_ifbuf) {
369 	    sc->sc_ifbuf = ptr;
370 	    return ENOBUFS;
371 	}
372 	if (ptr)
373 	    free(ptr,M_DEVBUF);
374 	sc->sc_if.if_mtu = ifr->ifr_mtu;
375 	break;
376 
377     case SIOCGIFMTU:
378 	ifr->ifr_mtu = sc->sc_if.if_mtu;
379 	break;
380 
381     case SIOCADDMULTI:
382     case SIOCDELMULTI:
383 	if (ifr == 0) {
384 	    return EAFNOSUPPORT;		/* XXX */
385 	}
386 	switch (ifr->ifr_addr.sa_family) {
387 
388 	case AF_INET:
389 	    break;
390 
391 	default:
392 	    return EAFNOSUPPORT;
393 	}
394 	break;
395 
396     case SIOCGIFMEDIA:
397 	/*
398 	 * No ifmedia support at this stage; maybe use it
399 	 * in future for eg. protocol selection.
400 	 */
401 	return EINVAL;
402 
403     default:
404 	lprintf("LP:ioctl(0x%lx)\n", cmd);
405 	return EINVAL;
406     }
407     return 0;
408 }
409 
410 static __inline int
411 clpoutbyte (u_char byte, int spin, device_t ppbus)
412 {
413 	ppb_wdtr(ppbus, ctxmitl[byte]);
414 	while (ppb_rstr(ppbus) & CLPIP_SHAKE)
415 		if (--spin == 0) {
416 			return 1;
417 		}
418 	ppb_wdtr(ppbus, ctxmith[byte]);
419 	while (!(ppb_rstr(ppbus) & CLPIP_SHAKE))
420 		if (--spin == 0) {
421 			return 1;
422 		}
423 	return 0;
424 }
425 
426 static __inline int
427 clpinbyte (int spin, device_t ppbus)
428 {
429 	u_char c, cl;
430 
431 	while((ppb_rstr(ppbus) & CLPIP_SHAKE))
432 	    if(!--spin) {
433 		return -1;
434 	    }
435 	cl = ppb_rstr(ppbus);
436 	ppb_wdtr(ppbus, 0x10);
437 
438 	while(!(ppb_rstr(ppbus) & CLPIP_SHAKE))
439 	    if(!--spin) {
440 		return -1;
441 	    }
442 	c = ppb_rstr(ppbus);
443 	ppb_wdtr(ppbus, 0x00);
444 
445 	return (ctrecvl[cl] | ctrecvh[c]);
446 }
447 
448 static void
449 lptap(struct ifnet *ifp, struct mbuf *m)
450 {
451 	u_int32_t af = AF_INET;
452 	BPF_MTAP2(ifp, &af, sizeof(af), m);
453 }
454 
455 static void
456 lp_intr (void *arg)
457 {
458 	device_t dev = (device_t)arg;
459         device_t ppbus = device_get_parent(dev);
460 	struct lp_data *sc = DEVTOSOFTC(dev);
461 	int len, s, j;
462 	u_char *bp;
463 	u_char c, cl;
464 	struct mbuf *top;
465 
466 	s = splhigh();
467 
468 	if (sc->sc_if.if_flags & IFF_LINK0) {
469 
470 	    /* Ack. the request */
471 	    ppb_wdtr(ppbus, 0x01);
472 
473 	    /* Get the packet length */
474 	    j = clpinbyte(LPMAXSPIN2, ppbus);
475 	    if (j == -1)
476 		goto err;
477 	    len = j;
478 	    j = clpinbyte(LPMAXSPIN2, ppbus);
479 	    if (j == -1)
480 		goto err;
481 	    len = len + (j << 8);
482 	    if (len > sc->sc_if.if_mtu + MLPIPHDRLEN)
483 		goto err;
484 
485 	    bp  = sc->sc_ifbuf;
486 
487 	    while (len--) {
488 	        j = clpinbyte(LPMAXSPIN2, ppbus);
489 	        if (j == -1) {
490 		    goto err;
491 	        }
492 	        *bp++ = j;
493 	    }
494 	    /* Get and ignore checksum */
495 	    j = clpinbyte(LPMAXSPIN2, ppbus);
496 	    if (j == -1) {
497 	        goto err;
498 	    }
499 
500 	    len = bp - sc->sc_ifbuf;
501 	    if (len <= CLPIPHDRLEN)
502 	        goto err;
503 
504 	    sc->sc_iferrs = 0;
505 
506 	    len -= CLPIPHDRLEN;
507 	    sc->sc_if.if_ipackets++;
508 	    sc->sc_if.if_ibytes += len;
509 	    top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, &sc->sc_if, 0);
510 	    if (top) {
511 		if (sc->sc_if.if_bpf)
512 		    lptap(&sc->sc_if, top);
513 		netisr_queue(NETISR_IP, top);
514 	    }
515 	    goto done;
516 	}
517 	while ((ppb_rstr(ppbus) & LPIP_SHAKE)) {
518 	    len = sc->sc_if.if_mtu + LPIPHDRLEN;
519 	    bp  = sc->sc_ifbuf;
520 	    while (len--) {
521 
522 		cl = ppb_rstr(ppbus);
523 		ppb_wdtr(ppbus, 8);
524 
525 		j = LPMAXSPIN2;
526 		while((ppb_rstr(ppbus) & LPIP_SHAKE))
527 		    if(!--j) goto err;
528 
529 		c = ppb_rstr(ppbus);
530 		ppb_wdtr(ppbus, 0);
531 
532 		*bp++= trecvh[cl] | trecvl[c];
533 
534 		j = LPMAXSPIN2;
535 		while (!((cl=ppb_rstr(ppbus)) & LPIP_SHAKE)) {
536 		    if (cl != c &&
537 			(((cl = ppb_rstr(ppbus)) ^ 0xb8) & 0xf8) ==
538 			  (c & 0xf8))
539 			goto end;
540 		    if (!--j) goto err;
541 		}
542 	    }
543 
544 	end:
545 	    len = bp - sc->sc_ifbuf;
546 	    if (len <= LPIPHDRLEN)
547 		goto err;
548 
549 	    sc->sc_iferrs = 0;
550 
551 	    len -= LPIPHDRLEN;
552 	    sc->sc_if.if_ipackets++;
553 	    sc->sc_if.if_ibytes += len;
554 	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
555 	    if (top) {
556 		if (sc->sc_if.if_bpf)
557 		    lptap(&sc->sc_if, top);
558 		netisr_queue(NETISR_IP, top);
559 	    }
560 	}
561 	goto done;
562 
563     err:
564 	ppb_wdtr(ppbus, 0);
565 	lprintf("R");
566 	sc->sc_if.if_ierrors++;
567 	sc->sc_iferrs++;
568 
569 	/*
570 	 * We are not able to send receive anything for now,
571 	 * so stop wasting our time
572 	 */
573 	if (sc->sc_iferrs > LPMAXERRS) {
574 	    printf("lp%d: Too many errors, Going off-line.\n", device_get_unit(dev));
575 	    ppb_wctr(ppbus, 0x00);
576 	    sc->sc_if.if_flags &= ~IFF_RUNNING;
577 	    sc->sc_iferrs=0;
578 	}
579 
580     done:
581 	splx(s);
582 	return;
583 }
584 
585 static __inline int
586 lpoutbyte (u_char byte, int spin, device_t ppbus)
587 {
588     ppb_wdtr(ppbus, txmith[byte]);
589     while (!(ppb_rstr(ppbus) & LPIP_SHAKE))
590 	if (--spin == 0)
591 		return 1;
592     ppb_wdtr(ppbus, txmitl[byte]);
593     while (ppb_rstr(ppbus) & LPIP_SHAKE)
594 	if (--spin == 0)
595 		return 1;
596     return 0;
597 }
598 
599 static int
600 lpoutput (struct ifnet *ifp, struct mbuf *m,
601 	  struct sockaddr *dst, struct rtentry *rt)
602 {
603     device_t dev = UNITODEVICE(ifp->if_dunit);
604     device_t ppbus = device_get_parent(dev);
605     int s, err;
606     struct mbuf *mm;
607     u_char *cp = "\0\0";
608     u_char chksum = 0;
609     int count = 0;
610     int i, len, spin;
611 
612     /* We need a sensible value if we abort */
613     cp++;
614     ifp->if_flags |= IFF_RUNNING;
615 
616     err = 1;			/* assume we're aborting because of an error */
617 
618     s = splhigh();
619 
620     /* Suspend (on laptops) or receive-errors might have taken us offline */
621     ppb_wctr(ppbus, IRQENABLE);
622 
623     if (ifp->if_flags & IFF_LINK0) {
624 
625 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
626 	    lprintf("&");
627 	    lp_intr(dev);
628 	}
629 
630 	/* Alert other end to pending packet */
631 	spin = LPMAXSPIN1;
632 	ppb_wdtr(ppbus, 0x08);
633 	while ((ppb_rstr(ppbus) & 0x08) == 0)
634 		if (--spin == 0) {
635 			goto nend;
636 		}
637 
638 	/* Calculate length of packet, then send that */
639 
640 	count += 14;		/* Ethernet header len */
641 
642 	mm = m;
643 	for (mm = m; mm; mm = mm->m_next) {
644 		count += mm->m_len;
645 	}
646 	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
647 		goto nend;
648 	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
649 		goto nend;
650 
651 	/* Send dummy ethernet header */
652 	for (i = 0; i < 12; i++) {
653 		if (clpoutbyte(i, LPMAXSPIN1, ppbus))
654 			goto nend;
655 		chksum += i;
656 	}
657 
658 	if (clpoutbyte(0x08, LPMAXSPIN1, ppbus))
659 		goto nend;
660 	if (clpoutbyte(0x00, LPMAXSPIN1, ppbus))
661 		goto nend;
662 	chksum += 0x08 + 0x00;		/* Add into checksum */
663 
664 	mm = m;
665 	do {
666 		cp = mtod(mm, u_char *);
667 		len = mm->m_len;
668 		while (len--) {
669 			chksum += *cp;
670 			if (clpoutbyte(*cp++, LPMAXSPIN2, ppbus))
671 				goto nend;
672 		}
673 	} while ((mm = mm->m_next));
674 
675 	/* Send checksum */
676 	if (clpoutbyte(chksum, LPMAXSPIN2, ppbus))
677 		goto nend;
678 
679 	/* Go quiescent */
680 	ppb_wdtr(ppbus, 0);
681 
682 	err = 0;			/* No errors */
683 
684 	nend:
685 	if (err)  {				/* if we didn't timeout... */
686 		ifp->if_oerrors++;
687 		lprintf("X");
688 	} else {
689 		ifp->if_opackets++;
690 		ifp->if_obytes += m->m_pkthdr.len;
691 		if (ifp->if_bpf)
692 		    lptap(ifp, m);
693 	}
694 
695 	m_freem(m);
696 
697 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
698 		lprintf("^");
699 		lp_intr(dev);
700 	}
701 	(void) splx(s);
702 	return 0;
703     }
704 
705     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
706         lprintf("&");
707         lp_intr(dev);
708     }
709 
710     if (lpoutbyte(0x08, LPMAXSPIN1, ppbus))
711         goto end;
712     if (lpoutbyte(0x00, LPMAXSPIN2, ppbus))
713         goto end;
714 
715     mm = m;
716     do {
717         cp = mtod(mm,u_char *);
718 	len = mm->m_len;
719         while (len--)
720 	    if (lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
721 	        goto end;
722     } while ((mm = mm->m_next));
723 
724     err = 0;				/* no errors were encountered */
725 
726     end:
727     --cp;
728     ppb_wdtr(ppbus, txmitl[*cp] ^ 0x17);
729 
730     if (err)  {				/* if we didn't timeout... */
731 	ifp->if_oerrors++;
732         lprintf("X");
733     } else {
734 	ifp->if_opackets++;
735 	ifp->if_obytes += m->m_pkthdr.len;
736 	if (ifp->if_bpf)
737 	    lptap(ifp, m);
738     }
739 
740     m_freem(m);
741 
742     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
743 	lprintf("^");
744 	lp_intr(dev);
745     }
746 
747     (void) splx(s);
748     return 0;
749 }
750 
751 static device_method_t lp_methods[] = {
752   	/* device interface */
753 	DEVMETHOD(device_identify,	lp_identify),
754 	DEVMETHOD(device_probe,		lp_probe),
755 	DEVMETHOD(device_attach,	lp_attach),
756 
757 	{ 0, 0 }
758 };
759 
760 static driver_t lp_driver = {
761   "plip",
762   lp_methods,
763   sizeof(struct lp_data),
764 };
765 
766 DRIVER_MODULE(plip, ppbus, lp_driver, lp_devclass, 0, 0);
767