xref: /freebsd/sys/dev/ppbus/if_plip.c (revision 729362425c09cf6b362366aabc6fb547eee8035a)
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  * $FreeBSD$
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 a 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 "opt_plip.h"
82 
83 #include <sys/param.h>
84 #include <sys/systm.h>
85 #include <sys/module.h>
86 #include <sys/bus.h>
87 #include <sys/mbuf.h>
88 #include <sys/socket.h>
89 #include <sys/sockio.h>
90 #include <sys/kernel.h>
91 #include <sys/malloc.h>
92 
93 #include <machine/bus.h>
94 #include <machine/resource.h>
95 #include <sys/rman.h>
96 
97 #include <net/if.h>
98 #include <net/if_types.h>
99 #include <net/netisr.h>
100 
101 #include <netinet/in.h>
102 #include <netinet/in_var.h>
103 
104 #include <net/bpf.h>
105 
106 #include <dev/ppbus/ppbconf.h>
107 #include "ppbus_if.h"
108 #include <dev/ppbus/ppbio.h>
109 
110 #ifndef LPMTU			/* MTU for the lp# interfaces */
111 #define	LPMTU	1500
112 #endif
113 
114 #ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
115 #define	LPMAXSPIN1	8000   /* Spinning for remote intr to happen */
116 #endif
117 
118 #ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
119 #define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
120 #endif
121 
122 #ifndef LPMAXERRS		/* Max errors before !RUNNING */
123 #define	LPMAXERRS	100
124 #endif
125 
126 #define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
127 #define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
128 #define MLPIPHDRLEN	CLPIPHDRLEN
129 
130 #define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
131 #define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
132 #if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
133 #define MLPIPHDRLEN	LPIPHDRLEN
134 #endif
135 
136 #define	LPIPTBLSIZE	256	/* Size of octet translation table */
137 
138 #define lprintf		if (lptflag) printf
139 
140 #ifdef PLIP_DEBUG
141 static int volatile lptflag = 1;
142 #else
143 static int volatile lptflag = 0;
144 #endif
145 
146 struct lp_data {
147 	unsigned short lp_unit;
148 
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 
187 	BUS_ADD_CHILD(parent, 0, "plip", -1);
188 }
189 /*
190  * lpprobe()
191  */
192 static int
193 lp_probe(device_t dev)
194 {
195 	device_t ppbus = device_get_parent(dev);
196 	struct lp_data *lp;
197 	int zero = 0;
198 	uintptr_t irq;
199 
200 	lp = DEVTOSOFTC(dev);
201 	bzero(lp, sizeof(struct lp_data));
202 
203 	/* retrieve the ppbus irq */
204 	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
205 
206 	/* if we haven't interrupts, the probe fails */
207 	if (irq == -1) {
208 		device_printf(dev, "not an interrupt driven port, failed.\n");
209 		return (ENXIO);
210 	}
211 
212 	/* reserve the interrupt resource, expecting irq is available to continue */
213 	lp->res_irq = bus_alloc_resource(dev, SYS_RES_IRQ, &zero, irq, irq, 1,
214 					 RF_SHAREABLE);
215 	if (lp->res_irq == 0) {
216 		device_printf(dev, "cannot reserve interrupt, failed.\n");
217 		return (ENXIO);
218 	}
219 
220 	/*
221 	 * lp dependent initialisation.
222 	 */
223 	lp->lp_unit = device_get_unit(dev);
224 
225 	device_set_desc(dev, "PLIP network interface");
226 
227 	return (0);
228 }
229 
230 static int
231 lp_attach (device_t dev)
232 {
233 	struct lp_data *lp = DEVTOSOFTC(dev);
234 	struct ifnet *ifp = &lp->sc_if;
235 
236 	ifp->if_softc = lp;
237 	ifp->if_name = "lp";
238 	ifp->if_unit = device_get_unit(dev);
239 	ifp->if_mtu = LPMTU;
240 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
241 	ifp->if_ioctl = lpioctl;
242 	ifp->if_output = lpoutput;
243 	ifp->if_type = IFT_PARA;
244 	ifp->if_hdrlen = 0;
245 	ifp->if_addrlen = 0;
246 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
247 	if_attach(ifp);
248 
249 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
250 
251 	return (0);
252 }
253 /*
254  * Build the translation tables for the LPIP (BSD unix) protocol.
255  * We don't want to calculate these nasties in our tight loop, so we
256  * precalculate them when we initialize.
257  */
258 static int
259 lpinittables (void)
260 {
261     int i;
262 
263     if (!txmith)
264 	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
265 
266     if (!txmith)
267 	return 1;
268 
269     if (!ctxmith)
270 	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
271 
272     if (!ctxmith)
273 	return 1;
274 
275     for (i=0; i < LPIPTBLSIZE; i++) {
276 	ctxmith[i] = (i & 0xF0) >> 4;
277 	ctxmitl[i] = 0x10 | (i & 0x0F);
278 	ctrecvh[i] = (i & 0x78) << 1;
279 	ctrecvl[i] = (i & 0x78) >> 3;
280     }
281 
282     for (i=0; i < LPIPTBLSIZE; i++) {
283 	txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
284 	txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
285 	trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
286 	trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
287     }
288 
289     return 0;
290 }
291 
292 /*
293  * Process an ioctl request.
294  */
295 
296 static int
297 lpioctl (struct ifnet *ifp, u_long cmd, caddr_t data)
298 {
299     device_t dev = UNITODEVICE(ifp->if_unit);
300     device_t ppbus = device_get_parent(dev);
301     struct lp_data *sc = DEVTOSOFTC(dev);
302     struct ifaddr *ifa = (struct ifaddr *)data;
303     struct ifreq *ifr = (struct ifreq *)data;
304     u_char *ptr;
305     void *ih;
306     int error;
307 
308     switch (cmd) {
309 
310     case SIOCSIFDSTADDR:
311     case SIOCAIFADDR:
312     case SIOCSIFADDR:
313 	if (ifa->ifa_addr->sa_family != AF_INET)
314 	    return EAFNOSUPPORT;
315 
316 	ifp->if_flags |= IFF_UP;
317 	/* FALLTHROUGH */
318     case SIOCSIFFLAGS:
319 	if ((!(ifp->if_flags & IFF_UP)) && (ifp->if_flags & IFF_RUNNING)) {
320 
321 	    ppb_wctr(ppbus, 0x00);
322 	    ifp->if_flags &= ~IFF_RUNNING;
323 
324 	    /* IFF_UP is not set, try to release the bus anyway */
325 	    ppb_release_bus(ppbus, dev);
326 	    break;
327 	}
328 	if (((ifp->if_flags & IFF_UP)) && (!(ifp->if_flags & IFF_RUNNING))) {
329 
330 	    /* XXX
331 	     * Should the request be interruptible?
332 	     */
333 	    if ((error = ppb_request_bus(ppbus, dev, PPB_WAIT|PPB_INTR)))
334 		return (error);
335 
336 	    /* Now IFF_UP means that we own the bus */
337 
338 	    ppb_set_mode(ppbus, PPB_COMPATIBLE);
339 
340 	    if (lpinittables()) {
341 		ppb_release_bus(ppbus, dev);
342 		return ENOBUFS;
343 	    }
344 
345 	    sc->sc_ifbuf = malloc(sc->sc_if.if_mtu + MLPIPHDRLEN,
346 				  M_DEVBUF, M_WAITOK);
347 	    if (!sc->sc_ifbuf) {
348 		ppb_release_bus(ppbus, dev);
349 		return ENOBUFS;
350 	    }
351 
352 	    /* attach our interrupt handler, later detached when the bus is released */
353 	    if ((error = BUS_SETUP_INTR(ppbus, dev, sc->res_irq,
354 					INTR_TYPE_NET, lp_intr, dev, &ih))) {
355 		ppb_release_bus(ppbus, dev);
356 		return (error);
357 	    }
358 
359 	    ppb_wctr(ppbus, IRQENABLE);
360 	    ifp->if_flags |= IFF_RUNNING;
361 	}
362 	break;
363 
364     case SIOCSIFMTU:
365 	ptr = sc->sc_ifbuf;
366 	sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
367 	if (!sc->sc_ifbuf) {
368 	    sc->sc_ifbuf = ptr;
369 	    return ENOBUFS;
370 	}
371 	if (ptr)
372 	    free(ptr,M_DEVBUF);
373 	sc->sc_if.if_mtu = ifr->ifr_mtu;
374 	break;
375 
376     case SIOCGIFMTU:
377 	ifr->ifr_mtu = sc->sc_if.if_mtu;
378 	break;
379 
380     case SIOCADDMULTI:
381     case SIOCDELMULTI:
382 	if (ifr == 0) {
383 	    return EAFNOSUPPORT;		/* XXX */
384 	}
385 	switch (ifr->ifr_addr.sa_family) {
386 
387 	case AF_INET:
388 	    break;
389 
390 	default:
391 	    return EAFNOSUPPORT;
392 	}
393 	break;
394 
395     case SIOCGIFMEDIA:
396 	/*
397 	 * No ifmedia support at this stage; maybe use it
398 	 * in future for eg. protocol selection.
399 	 */
400 	return EINVAL;
401 
402     default:
403 	lprintf("LP:ioctl(0x%lx)\n", cmd);
404 	return EINVAL;
405     }
406     return 0;
407 }
408 
409 static __inline int
410 clpoutbyte (u_char byte, int spin, device_t ppbus)
411 {
412 	ppb_wdtr(ppbus, ctxmitl[byte]);
413 	while (ppb_rstr(ppbus) & CLPIP_SHAKE)
414 		if (--spin == 0) {
415 			return 1;
416 		}
417 	ppb_wdtr(ppbus, ctxmith[byte]);
418 	while (!(ppb_rstr(ppbus) & CLPIP_SHAKE))
419 		if (--spin == 0) {
420 			return 1;
421 		}
422 	return 0;
423 }
424 
425 static __inline int
426 clpinbyte (int spin, device_t ppbus)
427 {
428 	u_char c, cl;
429 
430 	while((ppb_rstr(ppbus) & CLPIP_SHAKE))
431 	    if(!--spin) {
432 		return -1;
433 	    }
434 	cl = ppb_rstr(ppbus);
435 	ppb_wdtr(ppbus, 0x10);
436 
437 	while(!(ppb_rstr(ppbus) & CLPIP_SHAKE))
438 	    if(!--spin) {
439 		return -1;
440 	    }
441 	c = ppb_rstr(ppbus);
442 	ppb_wdtr(ppbus, 0x00);
443 
444 	return (ctrecvl[cl] | ctrecvh[c]);
445 }
446 
447 static void
448 lptap(struct ifnet *ifp, struct mbuf *m)
449 {
450 	/*
451 	 * Send a packet through bpf. We need to prepend the address family
452 	 * as a four byte field. Cons up a dummy header to pacify bpf. This
453 	 * is safe because bpf will only read from the mbuf (i.e., it won't
454 	 * try to free it or keep a pointer to it).
455 	 */
456 	u_int32_t af = AF_INET;
457 	struct mbuf m0;
458 
459 	m0.m_next = m;
460 	m0.m_len = sizeof(u_int32_t);
461 	m0.m_data = (char *)&af;
462 	BPF_MTAP(ifp, &m0);
463 }
464 
465 static void
466 lp_intr (void *arg)
467 {
468 	device_t dev = (device_t)arg;
469         device_t ppbus = device_get_parent(dev);
470 	struct lp_data *sc = DEVTOSOFTC(dev);
471 	int len, s, j;
472 	u_char *bp;
473 	u_char c, cl;
474 	struct mbuf *top;
475 
476 	s = splhigh();
477 
478 	if (sc->sc_if.if_flags & IFF_LINK0) {
479 
480 	    /* Ack. the request */
481 	    ppb_wdtr(ppbus, 0x01);
482 
483 	    /* Get the packet length */
484 	    j = clpinbyte(LPMAXSPIN2, ppbus);
485 	    if (j == -1)
486 		goto err;
487 	    len = j;
488 	    j = clpinbyte(LPMAXSPIN2, ppbus);
489 	    if (j == -1)
490 		goto err;
491 	    len = len + (j << 8);
492 	    if (len > sc->sc_if.if_mtu + MLPIPHDRLEN)
493 		goto err;
494 
495 	    bp  = sc->sc_ifbuf;
496 
497 	    while (len--) {
498 	        j = clpinbyte(LPMAXSPIN2, ppbus);
499 	        if (j == -1) {
500 		    goto err;
501 	        }
502 	        *bp++ = j;
503 	    }
504 	    /* Get and ignore checksum */
505 	    j = clpinbyte(LPMAXSPIN2, ppbus);
506 	    if (j == -1) {
507 	        goto err;
508 	    }
509 
510 	    len = bp - sc->sc_ifbuf;
511 	    if (len <= CLPIPHDRLEN)
512 	        goto err;
513 
514 	    sc->sc_iferrs = 0;
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 		netisr_queue(NETISR_IP, top);
524 	    }
525 	    goto done;
526 	}
527 	while ((ppb_rstr(ppbus) & LPIP_SHAKE)) {
528 	    len = sc->sc_if.if_mtu + LPIPHDRLEN;
529 	    bp  = sc->sc_ifbuf;
530 	    while (len--) {
531 
532 		cl = ppb_rstr(ppbus);
533 		ppb_wdtr(ppbus, 8);
534 
535 		j = LPMAXSPIN2;
536 		while((ppb_rstr(ppbus) & LPIP_SHAKE))
537 		    if(!--j) goto err;
538 
539 		c = ppb_rstr(ppbus);
540 		ppb_wdtr(ppbus, 0);
541 
542 		*bp++= trecvh[cl] | trecvl[c];
543 
544 		j = LPMAXSPIN2;
545 		while (!((cl=ppb_rstr(ppbus)) & LPIP_SHAKE)) {
546 		    if (cl != c &&
547 			(((cl = ppb_rstr(ppbus)) ^ 0xb8) & 0xf8) ==
548 			  (c & 0xf8))
549 			goto end;
550 		    if (!--j) goto err;
551 		}
552 	    }
553 
554 	end:
555 	    len = bp - sc->sc_ifbuf;
556 	    if (len <= LPIPHDRLEN)
557 		goto err;
558 
559 	    sc->sc_iferrs = 0;
560 
561 	    len -= LPIPHDRLEN;
562 	    sc->sc_if.if_ipackets++;
563 	    sc->sc_if.if_ibytes += len;
564 	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
565 	    if (top) {
566 		if (sc->sc_if.if_bpf)
567 		    lptap(&sc->sc_if, top);
568 		netisr_queue(NETISR_IP, top);
569 	    }
570 	}
571 	goto done;
572 
573     err:
574 	ppb_wdtr(ppbus, 0);
575 	lprintf("R");
576 	sc->sc_if.if_ierrors++;
577 	sc->sc_iferrs++;
578 
579 	/*
580 	 * We are not able to send receive anything for now,
581 	 * so stop wasting our time
582 	 */
583 	if (sc->sc_iferrs > LPMAXERRS) {
584 	    printf("lp%d: Too many errors, Going off-line.\n", device_get_unit(dev));
585 	    ppb_wctr(ppbus, 0x00);
586 	    sc->sc_if.if_flags &= ~IFF_RUNNING;
587 	    sc->sc_iferrs=0;
588 	}
589 
590     done:
591 	splx(s);
592 	return;
593 }
594 
595 static __inline int
596 lpoutbyte (u_char byte, int spin, device_t ppbus)
597 {
598     ppb_wdtr(ppbus, txmith[byte]);
599     while (!(ppb_rstr(ppbus) & LPIP_SHAKE))
600 	if (--spin == 0)
601 		return 1;
602     ppb_wdtr(ppbus, txmitl[byte]);
603     while (ppb_rstr(ppbus) & LPIP_SHAKE)
604 	if (--spin == 0)
605 		return 1;
606     return 0;
607 }
608 
609 static int
610 lpoutput (struct ifnet *ifp, struct mbuf *m,
611 	  struct sockaddr *dst, struct rtentry *rt)
612 {
613     device_t dev = UNITODEVICE(ifp->if_unit);
614     device_t ppbus = device_get_parent(dev);
615     int s, err;
616     struct mbuf *mm;
617     u_char *cp = "\0\0";
618     u_char chksum = 0;
619     int count = 0;
620     int i, len, spin;
621 
622     /* We need a sensible value if we abort */
623     cp++;
624     ifp->if_flags |= IFF_RUNNING;
625 
626     err = 1;			/* assume we're aborting because of an error */
627 
628     s = splhigh();
629 
630     /* Suspend (on laptops) or receive-errors might have taken us offline */
631     ppb_wctr(ppbus, IRQENABLE);
632 
633     if (ifp->if_flags & IFF_LINK0) {
634 
635 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
636 	    lprintf("&");
637 	    lp_intr(dev);
638 	}
639 
640 	/* Alert other end to pending packet */
641 	spin = LPMAXSPIN1;
642 	ppb_wdtr(ppbus, 0x08);
643 	while ((ppb_rstr(ppbus) & 0x08) == 0)
644 		if (--spin == 0) {
645 			goto nend;
646 		}
647 
648 	/* Calculate length of packet, then send that */
649 
650 	count += 14;		/* Ethernet header len */
651 
652 	mm = m;
653 	for (mm = m; mm; mm = mm->m_next) {
654 		count += mm->m_len;
655 	}
656 	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
657 		goto nend;
658 	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
659 		goto nend;
660 
661 	/* Send dummy ethernet header */
662 	for (i = 0; i < 12; i++) {
663 		if (clpoutbyte(i, LPMAXSPIN1, ppbus))
664 			goto nend;
665 		chksum += i;
666 	}
667 
668 	if (clpoutbyte(0x08, LPMAXSPIN1, ppbus))
669 		goto nend;
670 	if (clpoutbyte(0x00, LPMAXSPIN1, ppbus))
671 		goto nend;
672 	chksum += 0x08 + 0x00;		/* Add into checksum */
673 
674 	mm = m;
675 	do {
676 		cp = mtod(mm, u_char *);
677 		len = mm->m_len;
678 		while (len--) {
679 			chksum += *cp;
680 			if (clpoutbyte(*cp++, LPMAXSPIN2, ppbus))
681 				goto nend;
682 		}
683 	} while ((mm = mm->m_next));
684 
685 	/* Send checksum */
686 	if (clpoutbyte(chksum, LPMAXSPIN2, ppbus))
687 		goto nend;
688 
689 	/* Go quiescent */
690 	ppb_wdtr(ppbus, 0);
691 
692 	err = 0;			/* No errors */
693 
694 	nend:
695 	if (err)  {				/* if we didn't timeout... */
696 		ifp->if_oerrors++;
697 		lprintf("X");
698 	} else {
699 		ifp->if_opackets++;
700 		ifp->if_obytes += m->m_pkthdr.len;
701 		if (ifp->if_bpf)
702 		    lptap(ifp, m);
703 	}
704 
705 	m_freem(m);
706 
707 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
708 		lprintf("^");
709 		lp_intr(dev);
710 	}
711 	(void) splx(s);
712 	return 0;
713     }
714 
715     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
716         lprintf("&");
717         lp_intr(dev);
718     }
719 
720     if (lpoutbyte(0x08, LPMAXSPIN1, ppbus))
721         goto end;
722     if (lpoutbyte(0x00, LPMAXSPIN2, ppbus))
723         goto end;
724 
725     mm = m;
726     do {
727         cp = mtod(mm,u_char *);
728 	len = mm->m_len;
729         while (len--)
730 	    if (lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
731 	        goto end;
732     } while ((mm = mm->m_next));
733 
734     err = 0;				/* no errors were encountered */
735 
736     end:
737     --cp;
738     ppb_wdtr(ppbus, txmitl[*cp] ^ 0x17);
739 
740     if (err)  {				/* if we didn't timeout... */
741 	ifp->if_oerrors++;
742         lprintf("X");
743     } else {
744 	ifp->if_opackets++;
745 	ifp->if_obytes += m->m_pkthdr.len;
746 	if (ifp->if_bpf)
747 	    lptap(ifp, m);
748     }
749 
750     m_freem(m);
751 
752     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
753 	lprintf("^");
754 	lp_intr(dev);
755     }
756 
757     (void) splx(s);
758     return 0;
759 }
760 
761 static device_method_t lp_methods[] = {
762   	/* device interface */
763 	DEVMETHOD(device_identify,	lp_identify),
764 	DEVMETHOD(device_probe,		lp_probe),
765 	DEVMETHOD(device_attach,	lp_attach),
766 
767 	{ 0, 0 }
768 };
769 
770 static driver_t lp_driver = {
771   "plip",
772   lp_methods,
773   sizeof(struct lp_data),
774 };
775 
776 DRIVER_MODULE(plip, ppbus, lp_driver, lp_devclass, 0, 0);
777