xref: /dragonfly/sys/dev/netif/plip/if_plip.c (revision 9bb2a92d)
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 1.6 2004/01/06 03:17:24 dillon 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/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 <bus/ppbus/ppbconf.h>
109 #include "ppbus_if.h"
110 #include <bus/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 	unsigned short lp_unit;
150 
151 	struct  ifnet	sc_if;
152 	u_char		*sc_ifbuf;
153 	int		sc_iferrs;
154 
155 	struct resource *res_irq;
156 };
157 
158 /* Tables for the lp# interface */
159 static u_char *txmith;
160 #define txmitl (txmith+(1*LPIPTBLSIZE))
161 #define trecvh (txmith+(2*LPIPTBLSIZE))
162 #define trecvl (txmith+(3*LPIPTBLSIZE))
163 
164 static u_char *ctxmith;
165 #define ctxmitl (ctxmith+(1*LPIPTBLSIZE))
166 #define ctrecvh (ctxmith+(2*LPIPTBLSIZE))
167 #define ctrecvl (ctxmith+(3*LPIPTBLSIZE))
168 
169 /* Functions for the lp# interface */
170 static int lpinittables(void);
171 static int lpioctl(struct ifnet *, u_long, caddr_t);
172 static int lpoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
173 	struct rtentry *);
174 static void lp_intr(void *);
175 
176 #define DEVTOSOFTC(dev) \
177 	((struct lp_data *)device_get_softc(dev))
178 #define UNITOSOFTC(unit) \
179 	((struct lp_data *)devclass_get_softc(lp_devclass, (unit)))
180 #define UNITODEVICE(unit) \
181 	(devclass_get_device(lp_devclass, (unit)))
182 
183 static devclass_t lp_devclass;
184 
185 static void
186 lp_identify(driver_t *driver, device_t parent)
187 {
188 
189 	BUS_ADD_CHILD(parent, 0, "plip", 0);
190 }
191 /*
192  * lpprobe()
193  */
194 static int
195 lp_probe(device_t dev)
196 {
197 	device_t ppbus = device_get_parent(dev);
198 	struct lp_data *lp;
199 	int zero = 0;
200 	uintptr_t irq;
201 
202 	lp = DEVTOSOFTC(dev);
203 	bzero(lp, sizeof(struct lp_data));
204 
205 	/* retrieve the ppbus irq */
206 	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
207 
208 	/* if we haven't interrupts, the probe fails */
209 	if (irq == -1) {
210 		device_printf(dev, "not an interrupt driven port, failed.\n");
211 		return (ENXIO);
212 	}
213 
214 	/* reserve the interrupt resource, expecting irq is available to continue */
215 	lp->res_irq = bus_alloc_resource(dev, SYS_RES_IRQ, &zero, irq, irq, 1,
216 					 RF_SHAREABLE);
217 	if (lp->res_irq == 0) {
218 		device_printf(dev, "cannot reserve interrupt, failed.\n");
219 		return (ENXIO);
220 	}
221 
222 	/*
223 	 * lp dependent initialisation.
224 	 */
225 	lp->lp_unit = device_get_unit(dev);
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, "lp", 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 	/*
452 	 * Send a packet through bpf. We need to prepend the address family
453 	 * as a four byte field. Cons up a dummy header to pacify bpf. This
454 	 * is safe because bpf will only read from the mbuf (i.e., it won't
455 	 * try to free it or keep a pointer to it).
456 	 */
457 	u_int32_t af = AF_INET;
458 	struct mbuf m0;
459 
460 	m0.m_next = m;
461 	m0.m_len = sizeof(u_int32_t);
462 	m0.m_data = (char *)&af;
463 	bpf_mtap(ifp, &m0);
464 }
465 
466 static void
467 lp_intr (void *arg)
468 {
469 	device_t dev = (device_t)arg;
470         device_t ppbus = device_get_parent(dev);
471 	struct lp_data *sc = DEVTOSOFTC(dev);
472 	int len, s, j;
473 	u_char *bp;
474 	u_char c, cl;
475 	struct mbuf *top;
476 
477 	s = splhigh();
478 
479 	if (sc->sc_if.if_flags & IFF_LINK0) {
480 
481 	    /* Ack. the request */
482 	    ppb_wdtr(ppbus, 0x01);
483 
484 	    /* Get the packet length */
485 	    j = clpinbyte(LPMAXSPIN2, ppbus);
486 	    if (j == -1)
487 		goto err;
488 	    len = j;
489 	    j = clpinbyte(LPMAXSPIN2, ppbus);
490 	    if (j == -1)
491 		goto err;
492 	    len = len + (j << 8);
493 	    if (len > sc->sc_if.if_mtu + MLPIPHDRLEN)
494 		goto err;
495 
496 	    bp  = sc->sc_ifbuf;
497 
498 	    while (len--) {
499 	        j = clpinbyte(LPMAXSPIN2, ppbus);
500 	        if (j == -1) {
501 		    goto err;
502 	        }
503 	        *bp++ = j;
504 	    }
505 	    /* Get and ignore checksum */
506 	    j = clpinbyte(LPMAXSPIN2, ppbus);
507 	    if (j == -1) {
508 	        goto err;
509 	    }
510 
511 	    len = bp - sc->sc_ifbuf;
512 	    if (len <= CLPIPHDRLEN)
513 	        goto err;
514 
515 	    sc->sc_iferrs = 0;
516 
517 	    len -= CLPIPHDRLEN;
518 	    sc->sc_if.if_ipackets++;
519 	    sc->sc_if.if_ibytes += len;
520 	    top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, &sc->sc_if, 0);
521 	    if (top) {
522 		if (sc->sc_if.if_bpf)
523 		    lptap(&sc->sc_if, top);
524 		netisr_queue(NETISR_IP, top);
525 	    }
526 	    goto done;
527 	}
528 	while ((ppb_rstr(ppbus) & LPIP_SHAKE)) {
529 	    len = sc->sc_if.if_mtu + LPIPHDRLEN;
530 	    bp  = sc->sc_ifbuf;
531 	    while (len--) {
532 
533 		cl = ppb_rstr(ppbus);
534 		ppb_wdtr(ppbus, 8);
535 
536 		j = LPMAXSPIN2;
537 		while((ppb_rstr(ppbus) & LPIP_SHAKE))
538 		    if(!--j) goto err;
539 
540 		c = ppb_rstr(ppbus);
541 		ppb_wdtr(ppbus, 0);
542 
543 		*bp++= trecvh[cl] | trecvl[c];
544 
545 		j = LPMAXSPIN2;
546 		while (!((cl=ppb_rstr(ppbus)) & LPIP_SHAKE)) {
547 		    if (cl != c &&
548 			(((cl = ppb_rstr(ppbus)) ^ 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 	    len -= LPIPHDRLEN;
563 	    sc->sc_if.if_ipackets++;
564 	    sc->sc_if.if_ibytes += len;
565 	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
566 	    if (top) {
567 		if (sc->sc_if.if_bpf)
568 		    lptap(&sc->sc_if, top);
569 		netisr_queue(NETISR_IP, top);
570 	    }
571 	}
572 	goto done;
573 
574     err:
575 	ppb_wdtr(ppbus, 0);
576 	lprintf("R");
577 	sc->sc_if.if_ierrors++;
578 	sc->sc_iferrs++;
579 
580 	/*
581 	 * We are not able to send receive anything for now,
582 	 * so stop wasting our time
583 	 */
584 	if (sc->sc_iferrs > LPMAXERRS) {
585 	    printf("lp%d: Too many errors, Going off-line.\n", device_get_unit(dev));
586 	    ppb_wctr(ppbus, 0x00);
587 	    sc->sc_if.if_flags &= ~IFF_RUNNING;
588 	    sc->sc_iferrs=0;
589 	}
590 
591     done:
592 	splx(s);
593 	return;
594 }
595 
596 static __inline int
597 lpoutbyte (u_char byte, int spin, device_t ppbus)
598 {
599     ppb_wdtr(ppbus, txmith[byte]);
600     while (!(ppb_rstr(ppbus) & LPIP_SHAKE))
601 	if (--spin == 0)
602 		return 1;
603     ppb_wdtr(ppbus, txmitl[byte]);
604     while (ppb_rstr(ppbus) & LPIP_SHAKE)
605 	if (--spin == 0)
606 		return 1;
607     return 0;
608 }
609 
610 static int
611 lpoutput (struct ifnet *ifp, struct mbuf *m,
612 	  struct sockaddr *dst, struct rtentry *rt)
613 {
614     device_t dev = UNITODEVICE(ifp->if_dunit);
615     device_t ppbus = device_get_parent(dev);
616     int s, err;
617     struct mbuf *mm;
618     u_char *cp = "\0\0";
619     u_char chksum = 0;
620     int count = 0;
621     int i, len, spin;
622 
623     /* We need a sensible value if we abort */
624     cp++;
625     ifp->if_flags |= IFF_RUNNING;
626 
627     err = 1;			/* assume we're aborting because of an error */
628 
629     s = splhigh();
630 
631     /* Suspend (on laptops) or receive-errors might have taken us offline */
632     ppb_wctr(ppbus, IRQENABLE);
633 
634     if (ifp->if_flags & IFF_LINK0) {
635 
636 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
637 	    lprintf("&");
638 	    lp_intr(dev);
639 	}
640 
641 	/* Alert other end to pending packet */
642 	spin = LPMAXSPIN1;
643 	ppb_wdtr(ppbus, 0x08);
644 	while ((ppb_rstr(ppbus) & 0x08) == 0)
645 		if (--spin == 0) {
646 			goto nend;
647 		}
648 
649 	/* Calculate length of packet, then send that */
650 
651 	count += 14;		/* Ethernet header len */
652 
653 	mm = m;
654 	for (mm = m; mm; mm = mm->m_next) {
655 		count += mm->m_len;
656 	}
657 	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
658 		goto nend;
659 	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
660 		goto nend;
661 
662 	/* Send dummy ethernet header */
663 	for (i = 0; i < 12; i++) {
664 		if (clpoutbyte(i, LPMAXSPIN1, ppbus))
665 			goto nend;
666 		chksum += i;
667 	}
668 
669 	if (clpoutbyte(0x08, LPMAXSPIN1, ppbus))
670 		goto nend;
671 	if (clpoutbyte(0x00, LPMAXSPIN1, ppbus))
672 		goto nend;
673 	chksum += 0x08 + 0x00;		/* Add into checksum */
674 
675 	mm = m;
676 	do {
677 		cp = mtod(mm, u_char *);
678 		len = mm->m_len;
679 		while (len--) {
680 			chksum += *cp;
681 			if (clpoutbyte(*cp++, LPMAXSPIN2, ppbus))
682 				goto nend;
683 		}
684 	} while ((mm = mm->m_next));
685 
686 	/* Send checksum */
687 	if (clpoutbyte(chksum, LPMAXSPIN2, ppbus))
688 		goto nend;
689 
690 	/* Go quiescent */
691 	ppb_wdtr(ppbus, 0);
692 
693 	err = 0;			/* No errors */
694 
695 	nend:
696 	if (err)  {				/* if we didn't timeout... */
697 		ifp->if_oerrors++;
698 		lprintf("X");
699 	} else {
700 		ifp->if_opackets++;
701 		ifp->if_obytes += m->m_pkthdr.len;
702 		if (ifp->if_bpf)
703 		    lptap(ifp, m);
704 	}
705 
706 	m_freem(m);
707 
708 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
709 		lprintf("^");
710 		lp_intr(dev);
711 	}
712 	(void) splx(s);
713 	return 0;
714     }
715 
716     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
717         lprintf("&");
718         lp_intr(dev);
719     }
720 
721     if (lpoutbyte(0x08, LPMAXSPIN1, ppbus))
722         goto end;
723     if (lpoutbyte(0x00, LPMAXSPIN2, ppbus))
724         goto end;
725 
726     mm = m;
727     do {
728         cp = mtod(mm,u_char *);
729 	len = mm->m_len;
730         while (len--)
731 	    if (lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
732 	        goto end;
733     } while ((mm = mm->m_next));
734 
735     err = 0;				/* no errors were encountered */
736 
737     end:
738     --cp;
739     ppb_wdtr(ppbus, txmitl[*cp] ^ 0x17);
740 
741     if (err)  {				/* if we didn't timeout... */
742 	ifp->if_oerrors++;
743         lprintf("X");
744     } else {
745 	ifp->if_opackets++;
746 	ifp->if_obytes += m->m_pkthdr.len;
747 	if (ifp->if_bpf)
748 	    lptap(ifp, m);
749     }
750 
751     m_freem(m);
752 
753     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
754 	lprintf("^");
755 	lp_intr(dev);
756     }
757 
758     (void) splx(s);
759     return 0;
760 }
761 
762 static device_method_t lp_methods[] = {
763   	/* device interface */
764 	DEVMETHOD(device_identify,	lp_identify),
765 	DEVMETHOD(device_probe,		lp_probe),
766 	DEVMETHOD(device_attach,	lp_attach),
767 
768 	{ 0, 0 }
769 };
770 
771 static driver_t lp_driver = {
772   "plip",
773   lp_methods,
774   sizeof(struct lp_data),
775 };
776 
777 DECLARE_DUMMY_MODULE(if_plip);
778 DRIVER_MODULE(if_plip, ppbus, lp_driver, lp_devclass, 0, 0);
779 
780