xref: /freebsd/sys/dev/ppbus/if_plip.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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_ifp;
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", -1);
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 
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 
226 	device_set_desc(dev, "PLIP network interface");
227 
228 	return (0);
229 }
230 
231 static int
232 lp_attach (device_t dev)
233 {
234 	struct lp_data *lp = DEVTOSOFTC(dev);
235 	struct ifnet *ifp;
236 
237 	ifp = lp->sc_ifp = if_alloc(IFT_PARA);
238 	if (ifp == NULL) {
239 		return (ENOSPC);
240 	}
241 
242 	ifp->if_softc = lp;
243 	if_initname(ifp, device_get_name(dev), device_get_unit(dev));
244 	ifp->if_mtu = LPMTU;
245 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST |
246 	    IFF_NEEDSGIANT;
247 	ifp->if_ioctl = lpioctl;
248 	ifp->if_output = lpoutput;
249 	ifp->if_hdrlen = 0;
250 	ifp->if_addrlen = 0;
251 	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
252 	if_attach(ifp);
253 
254 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
255 
256 	return (0);
257 }
258 /*
259  * Build the translation tables for the LPIP (BSD unix) protocol.
260  * We don't want to calculate these nasties in our tight loop, so we
261  * precalculate them when we initialize.
262  */
263 static int
264 lpinittables (void)
265 {
266     int i;
267 
268     if (!txmith)
269 	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
270 
271     if (!txmith)
272 	return 1;
273 
274     if (!ctxmith)
275 	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
276 
277     if (!ctxmith)
278 	return 1;
279 
280     for (i=0; i < LPIPTBLSIZE; i++) {
281 	ctxmith[i] = (i & 0xF0) >> 4;
282 	ctxmitl[i] = 0x10 | (i & 0x0F);
283 	ctrecvh[i] = (i & 0x78) << 1;
284 	ctrecvl[i] = (i & 0x78) >> 3;
285     }
286 
287     for (i=0; i < LPIPTBLSIZE; i++) {
288 	txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
289 	txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
290 	trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
291 	trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
292     }
293 
294     return 0;
295 }
296 
297 /*
298  * Process an ioctl request.
299  */
300 
301 static int
302 lpioctl (struct ifnet *ifp, u_long cmd, caddr_t data)
303 {
304     device_t dev = UNITODEVICE(ifp->if_dunit);
305     device_t ppbus = device_get_parent(dev);
306     struct lp_data *sc = DEVTOSOFTC(dev);
307     struct ifaddr *ifa = (struct ifaddr *)data;
308     struct ifreq *ifr = (struct ifreq *)data;
309     u_char *ptr;
310     void *ih;
311     int error;
312 
313     switch (cmd) {
314 
315     case SIOCSIFDSTADDR:
316     case SIOCAIFADDR:
317     case SIOCSIFADDR:
318 	if (ifa->ifa_addr->sa_family != AF_INET)
319 	    return EAFNOSUPPORT;
320 
321 	ifp->if_flags |= IFF_UP;
322 	/* FALLTHROUGH */
323     case SIOCSIFFLAGS:
324 	if ((!(ifp->if_flags & IFF_UP)) &&
325 	  (ifp->if_drv_flags & IFF_DRV_RUNNING)) {
326 
327 	    ppb_wctr(ppbus, 0x00);
328 	    ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
329 
330 	    /* IFF_UP is not set, try to release the bus anyway */
331 	    ppb_release_bus(ppbus, dev);
332 	    break;
333 	}
334 	if (((ifp->if_flags & IFF_UP)) &&
335 	  (!(ifp->if_drv_flags & IFF_DRV_RUNNING))) {
336 
337 	    /* XXX
338 	     * Should the request be interruptible?
339 	     */
340 	    if ((error = ppb_request_bus(ppbus, dev, PPB_WAIT|PPB_INTR)))
341 		return (error);
342 
343 	    /* Now IFF_UP means that we own the bus */
344 
345 	    ppb_set_mode(ppbus, PPB_COMPATIBLE);
346 
347 	    if (lpinittables()) {
348 		ppb_release_bus(ppbus, dev);
349 		return ENOBUFS;
350 	    }
351 
352 	    sc->sc_ifbuf = malloc(sc->sc_ifp->if_mtu + MLPIPHDRLEN,
353 				  M_DEVBUF, M_WAITOK);
354 	    if (!sc->sc_ifbuf) {
355 		ppb_release_bus(ppbus, dev);
356 		return ENOBUFS;
357 	    }
358 
359 	    /* attach our interrupt handler, later detached when the bus is released */
360 	    if ((error = bus_setup_intr(dev, sc->res_irq,
361 					INTR_TYPE_NET, NULL, lp_intr, dev, &ih))) {
362 		ppb_release_bus(ppbus, dev);
363 		return (error);
364 	    }
365 
366 	    ppb_wctr(ppbus, IRQENABLE);
367 	    ifp->if_drv_flags |= IFF_DRV_RUNNING;
368 	}
369 	break;
370 
371     case SIOCSIFMTU:
372 	ptr = sc->sc_ifbuf;
373 	sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
374 	if (!sc->sc_ifbuf) {
375 	    sc->sc_ifbuf = ptr;
376 	    return ENOBUFS;
377 	}
378 	if (ptr)
379 	    free(ptr,M_DEVBUF);
380 	sc->sc_ifp->if_mtu = ifr->ifr_mtu;
381 	break;
382 
383     case SIOCGIFMTU:
384 	ifr->ifr_mtu = sc->sc_ifp->if_mtu;
385 	break;
386 
387     case SIOCADDMULTI:
388     case SIOCDELMULTI:
389 	if (ifr == 0) {
390 	    return EAFNOSUPPORT;		/* XXX */
391 	}
392 	switch (ifr->ifr_addr.sa_family) {
393 
394 	case AF_INET:
395 	    break;
396 
397 	default:
398 	    return EAFNOSUPPORT;
399 	}
400 	break;
401 
402     case SIOCGIFMEDIA:
403 	/*
404 	 * No ifmedia support at this stage; maybe use it
405 	 * in future for eg. protocol selection.
406 	 */
407 	return EINVAL;
408 
409     default:
410 	lprintf("LP:ioctl(0x%lx)\n", cmd);
411 	return EINVAL;
412     }
413     return 0;
414 }
415 
416 static __inline int
417 clpoutbyte (u_char byte, int spin, device_t ppbus)
418 {
419 	ppb_wdtr(ppbus, ctxmitl[byte]);
420 	while (ppb_rstr(ppbus) & CLPIP_SHAKE)
421 		if (--spin == 0) {
422 			return 1;
423 		}
424 	ppb_wdtr(ppbus, ctxmith[byte]);
425 	while (!(ppb_rstr(ppbus) & CLPIP_SHAKE))
426 		if (--spin == 0) {
427 			return 1;
428 		}
429 	return 0;
430 }
431 
432 static __inline int
433 clpinbyte (int spin, device_t ppbus)
434 {
435 	u_char c, cl;
436 
437 	while((ppb_rstr(ppbus) & CLPIP_SHAKE))
438 	    if(!--spin) {
439 		return -1;
440 	    }
441 	cl = ppb_rstr(ppbus);
442 	ppb_wdtr(ppbus, 0x10);
443 
444 	while(!(ppb_rstr(ppbus) & CLPIP_SHAKE))
445 	    if(!--spin) {
446 		return -1;
447 	    }
448 	c = ppb_rstr(ppbus);
449 	ppb_wdtr(ppbus, 0x00);
450 
451 	return (ctrecvl[cl] | ctrecvh[c]);
452 }
453 
454 static void
455 lptap(struct ifnet *ifp, struct mbuf *m)
456 {
457 	u_int32_t af = AF_INET;
458 	bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
459 }
460 
461 static void
462 lp_intr (void *arg)
463 {
464 	device_t dev = (device_t)arg;
465         device_t ppbus = device_get_parent(dev);
466 	struct lp_data *sc = DEVTOSOFTC(dev);
467 	int len, s, j;
468 	u_char *bp;
469 	u_char c, cl;
470 	struct mbuf *top;
471 
472 	s = splhigh();
473 
474 	if (sc->sc_ifp->if_flags & IFF_LINK0) {
475 
476 	    /* Ack. the request */
477 	    ppb_wdtr(ppbus, 0x01);
478 
479 	    /* Get the packet length */
480 	    j = clpinbyte(LPMAXSPIN2, ppbus);
481 	    if (j == -1)
482 		goto err;
483 	    len = j;
484 	    j = clpinbyte(LPMAXSPIN2, ppbus);
485 	    if (j == -1)
486 		goto err;
487 	    len = len + (j << 8);
488 	    if (len > sc->sc_ifp->if_mtu + MLPIPHDRLEN)
489 		goto err;
490 
491 	    bp  = sc->sc_ifbuf;
492 
493 	    while (len--) {
494 	        j = clpinbyte(LPMAXSPIN2, ppbus);
495 	        if (j == -1) {
496 		    goto err;
497 	        }
498 	        *bp++ = j;
499 	    }
500 	    /* Get and ignore checksum */
501 	    j = clpinbyte(LPMAXSPIN2, ppbus);
502 	    if (j == -1) {
503 	        goto err;
504 	    }
505 
506 	    len = bp - sc->sc_ifbuf;
507 	    if (len <= CLPIPHDRLEN)
508 	        goto err;
509 
510 	    sc->sc_iferrs = 0;
511 
512 	    len -= CLPIPHDRLEN;
513 	    sc->sc_ifp->if_ipackets++;
514 	    sc->sc_ifp->if_ibytes += len;
515 	    top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, sc->sc_ifp, 0);
516 	    if (top) {
517 		if (bpf_peers_present(sc->sc_ifp->if_bpf))
518 		    lptap(sc->sc_ifp, top);
519 		netisr_queue(NETISR_IP, top);	/* mbuf is free'd on failure. */
520 	    }
521 	    goto done;
522 	}
523 	while ((ppb_rstr(ppbus) & LPIP_SHAKE)) {
524 	    len = sc->sc_ifp->if_mtu + LPIPHDRLEN;
525 	    bp  = sc->sc_ifbuf;
526 	    while (len--) {
527 
528 		cl = ppb_rstr(ppbus);
529 		ppb_wdtr(ppbus, 8);
530 
531 		j = LPMAXSPIN2;
532 		while((ppb_rstr(ppbus) & LPIP_SHAKE))
533 		    if(!--j) goto err;
534 
535 		c = ppb_rstr(ppbus);
536 		ppb_wdtr(ppbus, 0);
537 
538 		*bp++= trecvh[cl] | trecvl[c];
539 
540 		j = LPMAXSPIN2;
541 		while (!((cl=ppb_rstr(ppbus)) & LPIP_SHAKE)) {
542 		    if (cl != c &&
543 			(((cl = ppb_rstr(ppbus)) ^ 0xb8) & 0xf8) ==
544 			  (c & 0xf8))
545 			goto end;
546 		    if (!--j) goto err;
547 		}
548 	    }
549 
550 	end:
551 	    len = bp - sc->sc_ifbuf;
552 	    if (len <= LPIPHDRLEN)
553 		goto err;
554 
555 	    sc->sc_iferrs = 0;
556 
557 	    len -= LPIPHDRLEN;
558 	    sc->sc_ifp->if_ipackets++;
559 	    sc->sc_ifp->if_ibytes += len;
560 	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, sc->sc_ifp, 0);
561 	    if (top) {
562 		if (bpf_peers_present(sc->sc_ifp->if_bpf))
563 		    lptap(sc->sc_ifp, top);
564 		netisr_queue(NETISR_IP, top);	/* mbuf is free'd on failure. */
565 	    }
566 	}
567 	goto done;
568 
569     err:
570 	ppb_wdtr(ppbus, 0);
571 	lprintf("R");
572 	sc->sc_ifp->if_ierrors++;
573 	sc->sc_iferrs++;
574 
575 	/*
576 	 * We are not able to send receive anything for now,
577 	 * so stop wasting our time
578 	 */
579 	if (sc->sc_iferrs > LPMAXERRS) {
580 	    printf("lp%d: Too many errors, Going off-line.\n", device_get_unit(dev));
581 	    ppb_wctr(ppbus, 0x00);
582 	    sc->sc_ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
583 	    sc->sc_iferrs=0;
584 	}
585 
586     done:
587 	splx(s);
588 	return;
589 }
590 
591 static __inline int
592 lpoutbyte (u_char byte, int spin, device_t ppbus)
593 {
594     ppb_wdtr(ppbus, txmith[byte]);
595     while (!(ppb_rstr(ppbus) & LPIP_SHAKE))
596 	if (--spin == 0)
597 		return 1;
598     ppb_wdtr(ppbus, txmitl[byte]);
599     while (ppb_rstr(ppbus) & LPIP_SHAKE)
600 	if (--spin == 0)
601 		return 1;
602     return 0;
603 }
604 
605 static int
606 lpoutput (struct ifnet *ifp, struct mbuf *m,
607 	  struct sockaddr *dst, struct rtentry *rt)
608 {
609     device_t dev = UNITODEVICE(ifp->if_dunit);
610     device_t ppbus = device_get_parent(dev);
611     int s, err;
612     struct mbuf *mm;
613     u_char *cp = "\0\0";
614     u_char chksum = 0;
615     int count = 0;
616     int i, len, spin;
617 
618     /* We need a sensible value if we abort */
619     cp++;
620     ifp->if_drv_flags |= IFF_DRV_RUNNING;
621 
622     err = 1;			/* assume we're aborting because of an error */
623 
624     s = splhigh();
625 
626     /* Suspend (on laptops) or receive-errors might have taken us offline */
627     ppb_wctr(ppbus, IRQENABLE);
628 
629     if (ifp->if_flags & IFF_LINK0) {
630 
631 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
632 	    lprintf("&");
633 	    lp_intr(dev);
634 	}
635 
636 	/* Alert other end to pending packet */
637 	spin = LPMAXSPIN1;
638 	ppb_wdtr(ppbus, 0x08);
639 	while ((ppb_rstr(ppbus) & 0x08) == 0)
640 		if (--spin == 0) {
641 			goto nend;
642 		}
643 
644 	/* Calculate length of packet, then send that */
645 
646 	count += 14;		/* Ethernet header len */
647 
648 	mm = m;
649 	for (mm = m; mm; mm = mm->m_next) {
650 		count += mm->m_len;
651 	}
652 	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
653 		goto nend;
654 	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
655 		goto nend;
656 
657 	/* Send dummy ethernet header */
658 	for (i = 0; i < 12; i++) {
659 		if (clpoutbyte(i, LPMAXSPIN1, ppbus))
660 			goto nend;
661 		chksum += i;
662 	}
663 
664 	if (clpoutbyte(0x08, LPMAXSPIN1, ppbus))
665 		goto nend;
666 	if (clpoutbyte(0x00, LPMAXSPIN1, ppbus))
667 		goto nend;
668 	chksum += 0x08 + 0x00;		/* Add into checksum */
669 
670 	mm = m;
671 	do {
672 		cp = mtod(mm, u_char *);
673 		len = mm->m_len;
674 		while (len--) {
675 			chksum += *cp;
676 			if (clpoutbyte(*cp++, LPMAXSPIN2, ppbus))
677 				goto nend;
678 		}
679 	} while ((mm = mm->m_next));
680 
681 	/* Send checksum */
682 	if (clpoutbyte(chksum, LPMAXSPIN2, ppbus))
683 		goto nend;
684 
685 	/* Go quiescent */
686 	ppb_wdtr(ppbus, 0);
687 
688 	err = 0;			/* No errors */
689 
690 	nend:
691 	if (err)  {				/* if we didn't timeout... */
692 		ifp->if_oerrors++;
693 		lprintf("X");
694 	} else {
695 		ifp->if_opackets++;
696 		ifp->if_obytes += m->m_pkthdr.len;
697 		if (bpf_peers_present(ifp->if_bpf))
698 		    lptap(ifp, m);
699 	}
700 
701 	m_freem(m);
702 
703 	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
704 		lprintf("^");
705 		lp_intr(dev);
706 	}
707 	(void) splx(s);
708 	return 0;
709     }
710 
711     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
712         lprintf("&");
713         lp_intr(dev);
714     }
715 
716     if (lpoutbyte(0x08, LPMAXSPIN1, ppbus))
717         goto end;
718     if (lpoutbyte(0x00, LPMAXSPIN2, ppbus))
719         goto end;
720 
721     mm = m;
722     do {
723         cp = mtod(mm,u_char *);
724 	len = mm->m_len;
725         while (len--)
726 	    if (lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
727 	        goto end;
728     } while ((mm = mm->m_next));
729 
730     err = 0;				/* no errors were encountered */
731 
732     end:
733     --cp;
734     ppb_wdtr(ppbus, txmitl[*cp] ^ 0x17);
735 
736     if (err)  {				/* if we didn't timeout... */
737 	ifp->if_oerrors++;
738         lprintf("X");
739     } else {
740 	ifp->if_opackets++;
741 	ifp->if_obytes += m->m_pkthdr.len;
742 	if (bpf_peers_present(ifp->if_bpf))
743 	    lptap(ifp, m);
744     }
745 
746     m_freem(m);
747 
748     if (ppb_rstr(ppbus) & LPIP_SHAKE) {
749 	lprintf("^");
750 	lp_intr(dev);
751     }
752 
753     (void) splx(s);
754     return 0;
755 }
756 
757 static device_method_t lp_methods[] = {
758   	/* device interface */
759 	DEVMETHOD(device_identify,	lp_identify),
760 	DEVMETHOD(device_probe,		lp_probe),
761 	DEVMETHOD(device_attach,	lp_attach),
762 
763 	{ 0, 0 }
764 };
765 
766 static driver_t lp_driver = {
767   "plip",
768   lp_methods,
769   sizeof(struct lp_data),
770 };
771 
772 DRIVER_MODULE(plip, ppbus, lp_driver, lp_devclass, 0, 0);
773 MODULE_DEPEND(plip, ppbus, 1, 1, 1);
774