xref: /netbsd-src/sys/dev/ppbus/if_plip.c (revision cac8e449158efc7261bebc8657cbb0125a2cfdde)
1 /* $NetBSD: if_plip.c,v 1.21 2008/04/18 14:56:40 cegger Exp $ */
2 
3 /*-
4  * Copyright (c) 1997 Poul-Henning Kamp
5  * Copyright (c) 2003, 2004 Gary Thorpe <gathorpe@users.sourceforge.net>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	From Id: lpt.c,v 1.55.2.1 1996/11/12 09:08:38 phk Exp
30  * FreeBSD: src/sys/dev/ppbus/if_plip.c,v 1.19.2.1 2000/05/24 00:20:57 n_hibma Exp
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: if_plip.c,v 1.21 2008/04/18 14:56:40 cegger Exp $");
35 
36 /*
37  * Parallel port TCP/IP interfaces added.  I looked at the driver from
38  * MACH but this is a complete rewrite, and btw. incompatible, and it
39  * should perform better too.  I have never run the MACH driver though.
40  *
41  * This driver sends two bytes (0x08, 0x00) in front of each packet,
42  * to allow us to distinguish another format later.
43  *
44  * Now added an Linux/Crynwr compatibility mode which is enabled using
45  * IF_LINK0 - Tim Wilkinson.
46  *
47  * TODO:
48  *    Make HDLC/PPP mode, use IF_LLC1 to enable.
49  *
50  * Connect the two computers using a Laplink parallel cable to use this
51  * feature:
52  *
53  *      +----------------------------------------+
54  * 	|A-name	A-End	B-End	Descr.	Port/Bit |
55  *      +----------------------------------------+
56  *	|DATA0	2	15	Data	0/0x01   |
57  *	|-ERROR	15	2	   	1/0x08   |
58  *      +----------------------------------------+
59  *	|DATA1	3	13	Data	0/0x02	 |
60  *	|+SLCT	13	3	   	1/0x10   |
61  *      +----------------------------------------+
62  *	|DATA2	4	12	Data	0/0x04   |
63  *	|+PE	12	4	   	1/0x20   |
64  *      +----------------------------------------+
65  *	|DATA3	5	10	Strobe	0/0x08   |
66  *	|-ACK	10	5	   	1/0x40   |
67  *      +----------------------------------------+
68  *	|DATA4	6	11	Data	0/0x10   |
69  *	|BUSY	11	6	   	1/~0x80  |
70  *      +----------------------------------------+
71  *	|GND	18-25	18-25	GND	-        |
72  *      +----------------------------------------+
73  *
74  * Expect transfer-rates up to 75 kbyte/sec.
75  *
76  * If GCC could correctly grok
77  *	register int port __asm("edx")
78  * the code would be cleaner
79  *
80  * Poul-Henning Kamp <phk@freebsd.org>
81  */
82 
83 /*
84  * Update for ppbus, PLIP support only - Nicolas Souchu
85  */
86 
87 #include "opt_inet.h"
88 #include "opt_plip.h"
89 #include "bpfilter.h"
90 
91 #include <sys/systm.h>
92 #include <sys/param.h>
93 #include <sys/proc.h>
94 #include <sys/types.h>
95 #include <sys/device.h>
96 #include <sys/ioctl.h>
97 #include <sys/malloc.h>
98 #include <sys/mbuf.h>
99 
100 #include <net/if.h>
101 #include <net/if_types.h>
102 #include <net/netisr.h>
103 
104 #if NBPFILTER > 0
105 #include <sys/time.h>
106 #include <net/bpf.h>
107 #endif
108 
109 #ifdef INET
110 #include <netinet/in_var.h>
111 /* #include <netinet/in.h> */
112 #else
113 #error Cannot config lp/plip without inet
114 #endif
115 
116 #include <dev/ppbus/ppbus_base.h>
117 #include <dev/ppbus/ppbus_device.h>
118 #include <dev/ppbus/ppbus_io.h>
119 #include <dev/ppbus/ppbus_var.h>
120 
121 #include <machine/types.h>
122 #include <sys/intr.h>
123 
124 #ifndef LPMTU			/* MTU for the lp# interfaces */
125 #define	LPMTU		1500
126 #endif
127 
128 #ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
129 #define	LPMAXSPIN1	8000	/* Spinning for remote intr to happen */
130 #endif
131 
132 #ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
133 #define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
134 #endif
135 
136 #ifndef LPMAXERRS		/* Max errors before !RUNNING */
137 #define	LPMAXERRS	100
138 #endif
139 
140 #ifndef LPMAXRTRY
141 #define LPMAXRTRY	100	/* If channel busy, retry LPMAXRTRY
142 					consecutive times */
143 #endif
144 
145 #define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
146 #define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
147 #define MLPIPHDRLEN	CLPIPHDRLEN
148 
149 #define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
150 #define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
151 #if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
152 #define MLPIPHDRLEN	LPIPHDRLEN
153 #endif
154 
155 #define	LPIPTBLSIZE	256	/* Size of octet translation table */
156 
157 #define LP_PRINTF	if (lpflag) printf
158 
159 #ifdef PLIP_DEBUG
160 static int volatile lpflag = 1;
161 #else
162 static int volatile lpflag = 0;
163 #endif
164 
165 /* Tx/Rsv tables for the lp interface */
166 static u_char *txmith;
167 #define txmitl (txmith+(1*LPIPTBLSIZE))
168 #define trecvh (txmith+(2*LPIPTBLSIZE))
169 #define trecvl (txmith+(3*LPIPTBLSIZE))
170 static u_char *ctxmith;
171 #define ctxmitl (ctxmith+(1*LPIPTBLSIZE))
172 #define ctrecvh (ctxmith+(2*LPIPTBLSIZE))
173 #define ctrecvl (ctxmith+(3*LPIPTBLSIZE))
174 static uint16_t lp_count = 0;
175 
176 /* Autoconf functions */
177 static int lp_probe(device_t, cfdata_t, void *);
178 static void lp_attach(device_t, device_t, void *);
179 static int lp_detach(device_t, int);
180 
181 /* Soft config data */
182 struct lp_softc {
183 	struct ppbus_device_softc ppbus_dev;
184 	struct ifnet sc_if;
185 	u_char *sc_ifbuf;
186 	unsigned short sc_iferrs;
187 	unsigned short sc_xmit_rtry;
188 	u_int8_t sc_dev_ok; /* Zero means ok */
189 };
190 
191 /* Autoconf structure */
192 CFATTACH_DECL_NEW(plip, sizeof(struct lp_softc), lp_probe, lp_attach, lp_detach,
193 	NULL);
194 
195 /* Functions for the lp interface */
196 static void lpinittables(void);
197 static void lpfreetables(void);
198 static int lpioctl(struct ifnet *, u_long, void *);
199 static int lpoutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
200 	struct rtentry *);
201 static void lpstart(struct ifnet *);
202 static void lp_intr(void *);
203 
204 
205 static int
206 lp_probe(device_t parent, cfdata_t match, void *aux)
207 {
208 	struct ppbus_attach_args * args = aux;
209 
210 	/* Fail if ppbus is not interrupt capable */
211 	if(args->capabilities & PPBUS_HAS_INTR)
212 		return 1;
213 
214 	printf("%s(%s): not an interrupt-driven port.\n", __func__,
215 		device_xname(parent));
216 	return 0;
217 }
218 
219 static void
220 lp_attach(device_t parent, device_t self, void *aux)
221 {
222 	struct lp_softc * lp = device_private(self);
223 	struct ifnet * ifp = &lp->sc_if;
224 
225 	lp->ppbus_dev.sc_dev = self;
226 	lp->sc_dev_ok = 0;
227 	lp->sc_ifbuf = NULL;
228 	lp->sc_iferrs = 0;
229 	lp->sc_xmit_rtry = 0;
230 
231 	ifp->if_softc = lp;
232 	strlcpy(ifp->if_xname, device_xname(self), IFNAMSIZ);
233 	ifp->if_mtu = LPMTU;
234 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
235 	ifp->if_ioctl = lpioctl;
236 	ifp->if_output = lpoutput;
237 	ifp->if_start = lpstart;
238 	ifp->if_type = IFT_PARA;
239 	ifp->if_hdrlen = 0;
240 	ifp->if_addrlen = 0;
241 	ifp->if_dlt = DLT_NULL;
242 	IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN);
243 	IFQ_SET_READY(&ifp->if_snd);
244 	if_attach(ifp);
245 	if_alloc_sadl(ifp);
246 
247 #if NBPFILTER > 0
248 	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
249 #endif
250 
251 	if(lp_count++ == 0)
252 		lpinittables();
253 	printf("\n");
254 }
255 
256 static int
257 lp_detach(device_t self, int flags)
258 {
259 	int error = 0;
260 	struct lp_softc * lp = device_private(self);
261 	device_t ppbus = device_parent(self);
262 
263 	if(lp->sc_dev_ok) {
264 		if(!(flags & DETACH_QUIET))
265 			LP_PRINTF("%s(%s): device not properly attached! "
266 				"Skipping detach....\n", __func__,
267 				device_xname(self));
268 		return error;
269 	}
270 
271 	/* If interface is up, bring it down and release ppbus */
272 	if(lp->sc_if.if_flags & IFF_RUNNING) {
273 		ppbus_wctr(ppbus, 0x00);
274 		if_detach(&lp->sc_if);
275 		error = ppbus_remove_handler(ppbus, lp_intr);
276 		if(error) {
277 			if(!(flags & DETACH_QUIET))
278 				LP_PRINTF("%s(%s): unable to remove interrupt "
279 					"callback.\n", __func__,
280 					device_xname(self));
281 			if(!(flags & DETACH_FORCE))
282 				return error;
283 		}
284 		error = ppbus_release_bus(ppbus, self, 0, 0);
285 		if(error) {
286 			if(!(flags & DETACH_QUIET))
287 				LP_PRINTF("%s(%s): error releasing bus %s.\n",
288 					__func__, device_xname(self),
289 					device_xname(ppbus));
290 			if(!(flags & DETACH_FORCE))
291 				return error;
292 		}
293 	}
294 
295 	if(lp->sc_ifbuf)
296 		free(lp->sc_ifbuf, M_DEVBUF);
297 
298 	if(--lp_count == 0)
299 		lpfreetables();
300 	return error;
301 }
302 
303 /*
304  * Build the translation tables for the LPIP (BSD unix) protocol.
305  * We don't want to calculate these nasties in our tight loop, so we
306  * precalculate them when we initialize.
307  */
308 static void
309 lpinittables (void)
310 {
311 	int i;
312 
313 	if (!txmith)
314 		txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_WAITOK);
315 
316 	if (!ctxmith)
317 		ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_WAITOK);
318 
319 	for(i = 0; i < LPIPTBLSIZE; i++) {
320 		ctxmith[i] = (i & 0xF0) >> 4;
321 		ctxmitl[i] = 0x10 | (i & 0x0F);
322 		ctrecvh[i] = (i & 0x78) << 1;
323 		ctrecvl[i] = (i & 0x78) >> 3;
324 	}
325 
326 	for(i = 0; i < LPIPTBLSIZE; i++) {
327 		txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
328 		txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
329 		trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
330 		trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
331 	}
332 }
333 
334 /* Free translation tables */
335 static void
336 lpfreetables (void)
337 {
338 	if (txmith)
339 		free(txmith, M_DEVBUF);
340 	if (ctxmith)
341 		free(ctxmith, M_DEVBUF);
342 	txmith = ctxmith = NULL;
343 }
344 
345 
346 /* Process an ioctl request. */
347 static int
348 lpioctl (struct ifnet *ifp, u_long cmd, void *data)
349 {
350 	struct lp_softc * sc = ifp->if_softc;
351 	device_t dev = sc->ppbus_dev.sc_dev;
352 	device_t ppbus = device_parent(dev);
353 	struct ifaddr * ifa = (struct ifaddr *)data;
354 	struct ifreq * ifr = (struct ifreq *)data;
355 	u_char * ptr;
356 	int error, s;
357 
358 	error = 0;
359 	s = splnet();
360 
361 	if(sc->sc_dev_ok) {
362 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
363 			device_xname(dev));
364 		error = ENODEV;
365 		goto end;
366 	}
367 
368 	switch (cmd) {
369 
370 	case SIOCSIFDSTADDR:
371 		if (ifa->ifa_addr->sa_family != AF_INET)
372 			error = EAFNOSUPPORT;
373 		break;
374 
375 	case SIOCSIFADDR:
376 		if (ifa->ifa_addr->sa_family != AF_INET) {
377 			error = EAFNOSUPPORT;
378 			break;
379 		}
380 		ifp->if_flags |= IFF_UP;
381 	/* FALLTHROUGH */
382 	case SIOCSIFFLAGS:
383 		if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) == IFF_UP) {
384 			if((error = ppbus_request_bus(ppbus, dev, 0, 0)))
385 				break;
386 			error = ppbus_set_mode(ppbus, PPBUS_COMPATIBLE, 0);
387 			if(error)
388 				break;
389 
390 			error = ppbus_add_handler(ppbus, lp_intr, dev);
391 			if(error) {
392 				LP_PRINTF("%s(%s): unable to register interrupt"
393 					" callback.\n", __func__,
394 					device_xname(dev));
395 				ppbus_release_bus(ppbus, dev, 0, 0);
396 				break;
397 			}
398 
399 			/* Allocate a buffer if necessary */
400 			if(sc->sc_ifbuf == NULL) {
401 				sc->sc_ifbuf = malloc(sc->sc_if.if_mtu +
402 					MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
403 				if (!sc->sc_ifbuf) {
404 					error = ENOBUFS;
405 					ppbus_release_bus(ppbus, dev, 0, 0);
406 					break;
407 				}
408 			}
409 
410 			ppbus_wctr(ppbus, IRQENABLE);
411 			ifp->if_flags |= IFF_RUNNING;
412 		}
413 		if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) == IFF_RUNNING) {
414 			ppbus_remove_handler(ppbus, lp_intr);
415 			error = ppbus_release_bus(ppbus, dev, 0, 0);
416 			ifp->if_flags &= ~IFF_RUNNING;
417 		}
418 		/* Go quiescent */
419 		ppbus_wdtr(ppbus, 0);
420 		break;
421 
422 	case SIOCSIFMTU:
423 		if(sc->sc_if.if_mtu == ifr->ifr_mtu)
424 			break;
425 		ptr = sc->sc_ifbuf;
426 		sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF,
427 			M_NOWAIT);
428 		if (!sc->sc_ifbuf) {
429 			sc->sc_ifbuf = ptr;
430 			error = ENOBUFS;
431 			break;
432 		}
433 		if(ptr)
434 			free(ptr,M_DEVBUF);
435 		/*FALLTHROUGH*/
436 	case SIOCGIFMTU:
437 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
438 			error = 0;
439 		break;
440 
441 	case SIOCADDMULTI:
442 	case SIOCDELMULTI:
443 		if (ifr == NULL) {
444 			error = EAFNOSUPPORT;		/* XXX */
445 			break;
446 		}
447 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
448 		case AF_INET:
449 			break;
450 		default:
451 			return EAFNOSUPPORT;
452 		}
453 		break;
454 
455 	case SIOCGIFMEDIA:
456 		/*
457 		 * No ifmedia support at this stage; maybe use it
458 		 * in future for eg. protocol selection.
459 		 */
460 	default:
461 		LP_PRINTF("LP:ioctl(0x%lx)\n", cmd);
462 		error = EINVAL;
463 	}
464 
465 end:
466 	splx(s);
467 	return error;
468 }
469 
470 static inline int
471 clpoutbyte (u_char byte, int spin, device_t ppbus)
472 {
473 	int s = spin;
474 	ppbus_wdtr(ppbus, ctxmitl[byte]);
475 	while (ppbus_rstr(ppbus) & CLPIP_SHAKE) {
476 		if (--s == 0) {
477 			return 1;
478 		}
479 	}
480 	s = spin;
481 	ppbus_wdtr(ppbus, ctxmith[byte]);
482 	while (!(ppbus_rstr(ppbus) & CLPIP_SHAKE)) {
483 		if (--s == 0) {
484 			return 1;
485 		}
486 	}
487 	return 0;
488 }
489 
490 static inline int
491 clpinbyte (int spin, device_t ppbus)
492 {
493 	u_char c, cl;
494 	int s = spin;
495 
496 	while(ppbus_rstr(ppbus) & CLPIP_SHAKE) {
497 		if(!--s) {
498 			return -1;
499 		}
500 	}
501 	cl = ppbus_rstr(ppbus);
502 	ppbus_wdtr(ppbus, 0x10);
503 
504 	s = spin;
505 	while(!(ppbus_rstr(ppbus) & CLPIP_SHAKE)) {
506 		if(!--s) {
507 			return -1;
508 		}
509 	}
510 	c = ppbus_rstr(ppbus);
511 	ppbus_wdtr(ppbus, 0x00);
512 
513 	return (ctrecvl[cl] | ctrecvh[c]);
514 }
515 
516 #if NBPFILTER > 0
517 static void
518 lptap(struct ifnet *ifp, struct mbuf *m)
519 {
520 	/*
521 	 * Send a packet through bpf. We need to prepend the address family
522 	 * as a four byte field. Cons up a dummy header to pacify bpf. This
523 	 * is safe because bpf will only read from the mbuf (i.e., it won't
524 	 * try to free it or keep a pointer to it).
525 	 */
526 	u_int32_t af = AF_INET;
527 	struct mbuf m0;
528 
529 	m0.m_next = m;
530 	m0.m_len = sizeof(u_int32_t);
531 	m0.m_data = (char *)&af;
532 	bpf_mtap(ifp->if_bpf, &m0);
533 }
534 #endif
535 
536 /* Soft interrupt handler called by hardware interrupt handler */
537 static void
538 lp_intr (void *arg)
539 {
540 	device_t dev = (device_t)arg;
541         device_t ppbus = device_parent(dev);
542 	struct lp_softc * sc = device_private(dev);
543 	struct ifnet * ifp = &sc->sc_if;
544 	struct mbuf *top;
545 	int len, s, j;
546 	u_char *bp;
547 	u_char c, cl;
548 
549 	s = splnet();
550 
551 	/* Do nothing if device not properly attached */
552 	if(sc->sc_dev_ok) {
553 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
554 			device_xname(dev));
555 		goto done;
556 	}
557 
558 	/* Do nothing if interface is not up */
559 	if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
560 		goto done;
561 
562 	/* If other side is no longer transmitting, do nothing */
563 	if(!(ppbus_rstr(ppbus) & LPIP_SHAKE))
564 		goto done;
565 
566 	/* Disable interrupts until we finish */
567 	ppbus_wctr(ppbus, ~IRQENABLE);
568 
569 	top = NULL;
570 	bp = sc->sc_ifbuf;
571 	/* Linux/crynwyr protocol receiving */
572 	if(ifp->if_flags & IFF_LINK0) {
573 		/* Ack. the request */
574 		ppbus_wdtr(ppbus, 0x01);
575 
576 		/* Get the packet length */
577 		j = clpinbyte(LPMAXSPIN2, ppbus);
578 		if(j == -1)
579 			goto err;
580 		len = j;
581 		j = clpinbyte(LPMAXSPIN2, ppbus);
582 		if(j == -1)
583 			goto err;
584 		len = len + (j << 8);
585 		if(len > ifp->if_mtu + MLPIPHDRLEN)
586 			goto err;
587 
588 		while(len--) {
589 			j = clpinbyte(LPMAXSPIN2, ppbus);
590 			if (j == -1) {
591 				goto err;
592 			}
593 			*bp++ = j;
594 		}
595 		/* Get and ignore checksum */
596 		j = clpinbyte(LPMAXSPIN2, ppbus);
597 		if(j == -1) {
598 			goto err;
599 		}
600 
601 		/* Return to idle state */
602 		ppbus_wdtr(ppbus, 0);
603 		len = bp - sc->sc_ifbuf;
604 		if (len <= CLPIPHDRLEN)
605 			goto err;
606 		len -= CLPIPHDRLEN;
607 		top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, ifp, NULL);
608 	}
609 	/* FreeBSD protocol receiving */
610 	else {
611 		len = ifp->if_mtu + LPIPHDRLEN;
612 		while(len--) {
613 			cl = ppbus_rstr(ppbus);
614 			ppbus_wdtr(ppbus, 0x08);
615 
616 			j = LPMAXSPIN2;
617 			while((ppbus_rstr(ppbus) & LPIP_SHAKE)) {
618 				if(!--j) goto err;
619 			}
620 
621 			c = ppbus_rstr(ppbus);
622 			ppbus_wdtr(ppbus, 0);
623 
624 			*bp++= trecvh[cl] | trecvl[c];
625 
626 			j = LPMAXSPIN2;
627 			while(!((cl=ppbus_rstr(ppbus)) & LPIP_SHAKE)) {
628 				if(cl != c &&
629 					(((cl = ppbus_rstr(ppbus)) ^ 0xb8) &
630 					0xf8) == (c & 0xf8))
631 					goto end;
632 				if(!--j) goto err;
633 			}
634 		}
635 
636 end:
637 		len = bp - sc->sc_ifbuf;
638 		if(len <= LPIPHDRLEN)
639 			goto err;
640 		len -= LPIPHDRLEN;
641 		top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, ifp, NULL);
642 	}
643 
644 	/* Do nothing if mbuf was not created or the queue is full */
645 	if((top == NULL) || (IF_QFULL(&ipintrq))) {
646 		IF_DROP(&ipintrq);
647 		ifp->if_iqdrops++;
648 		LP_PRINTF("DROP");
649 		goto err;
650 	}
651 #if NBPFILTER > 0
652 	if(ifp->if_bpf)
653 		lptap(ifp, top);
654 #endif
655 	IF_ENQUEUE(&ipintrq, top);
656 	schednetisr(NETISR_IP);
657 	ifp->if_ipackets++;
658 	ifp->if_ibytes += len;
659 	sc->sc_iferrs = 0;
660 
661 	goto done;
662 
663 err:
664 	/* Return to idle state */
665 	ppbus_wdtr(ppbus, 0);
666 	ifp->if_ierrors++;
667 	sc->sc_iferrs++;
668 	LP_PRINTF("R");
669 	/* Disable interface if there are too many errors */
670 	if(sc->sc_iferrs > LPMAXERRS) {
671 		aprint_error_dev(dev, "Too many consecutive errors, going off-line.\n");
672 		ppbus_wctr(ppbus, ~IRQENABLE);
673 		if_down(ifp);
674 		sc->sc_iferrs = 0;
675 	}
676 
677 done:
678 	/* Re-enable interrupts */
679 	ppbus_wctr(ppbus, IRQENABLE);
680 	/* If interface is not active, send some packets */
681 	if((ifp->if_flags & IFF_OACTIVE) == 0)
682 		lpstart(ifp);
683 	splx(s);
684 	return;
685 }
686 
687 static inline int
688 lpoutbyte(u_char byte, int spin, device_t ppbus)
689 {
690 	int s = spin;
691 	ppbus_wdtr(ppbus, txmith[byte]);
692 	while(!(ppbus_rstr(ppbus) & LPIP_SHAKE)) {
693 		if(--s == 0)
694 			return 1;
695 	}
696 	s = spin;
697 	ppbus_wdtr(ppbus, txmitl[byte]);
698 	while(ppbus_rstr(ppbus) & LPIP_SHAKE) {
699 		if(--s == 0)
700 			return 1;
701 	}
702 	return 0;
703 }
704 
705 /* Queue a packet for delivery */
706 static int
707 lpoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
708 	struct rtentry *rt)
709 {
710 	struct lp_softc * sc = ifp->if_softc;
711 	device_t dev = sc->ppbus_dev.sc_dev;
712 	device_t ppbus = device_parent(dev);
713 	ALTQ_DECL(struct altq_pktattr pktattr;)
714 	int err;
715 	int s;
716 
717 	s = splnet();
718 
719 	if(sc->sc_dev_ok) {
720 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
721 			device_xname(dev));
722 		err = ENODEV;
723 		goto endoutput;
724 	}
725 
726 	if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
727 		err = ENETDOWN;
728 		goto endoutput;
729 	}
730 
731 	/* Only support INET */
732 	if(dst->sa_family != AF_INET) {
733 		LP_PRINTF("%s: af%d not supported\n", ifp->if_xname,
734 		    dst->sa_family);
735 		ifp->if_noproto++;
736 		err = EAFNOSUPPORT;
737 		goto endoutput;
738 	}
739 
740 	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
741 	IFQ_ENQUEUE(&ifp->if_snd, m, NULL, err);
742 	if(err == 0) {
743 		if((ifp->if_flags & IFF_OACTIVE) == 0)
744 			lpstart(ifp);
745 	}
746 	else {
747 		ifp->if_oerrors++;
748 		sc->sc_iferrs++;
749 		LP_PRINTF("Q");
750 
751 		/* Disable interface if there are too many errors */
752 		if(sc->sc_iferrs > LPMAXERRS) {
753 			aprint_error_dev(dev, "Too many errors, going off-line.\n");
754 			ppbus_wctr(ppbus, ~IRQENABLE);
755 			if_down(ifp);
756 			sc->sc_iferrs = 0;
757 		}
758 	}
759 
760 endoutput:
761 	if((err != 0) && (err != ENOBUFS))
762 		m_freem(m);
763 	splx(s);
764 	return err;
765 }
766 
767 /* Send routine: send packets over PLIP cable. Call at splnet(). */
768 void
769 lpstart(struct ifnet * ifp)
770 {
771 	struct lp_softc * lp = ifp->if_softc;
772 	device_t dev = lp->ppbus_dev.sc_dev;
773 	device_t ppbus = device_parent(dev);
774 	struct mbuf * mm;
775 	struct mbuf * m;
776 	u_char * cp;
777 	int err, i, len, spin, count;
778 	u_char str, chksum;
779 
780 	if(lp->sc_dev_ok) {
781 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
782 			device_xname(dev));
783 		return;
784 	}
785 
786 	if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
787 		return;
788 	}
789 
790 	ifp->if_flags |= IFF_OACTIVE;
791 
792 	/* Go quiescent */
793 	ppbus_wdtr(ppbus, 0);
794 
795 	/* Output loop */
796 	for(;;) {
797 		/* Check if there are packets to send */
798 		if(IFQ_IS_EMPTY(&ifp->if_snd)) {
799 			goto final;
800 		}
801 		/* Try to send a packet, dequeue it later if successful */
802 		IFQ_POLL(&ifp->if_snd, m);
803 		if(m == NULL)
804 			goto final;
805 
806 		str = ppbus_rstr(ppbus);
807 		/* Wait until other side is not transmitting */
808 		if((str & LPIP_SHAKE) ||
809 			((ifp->if_flags & IFF_LINK0) && !(str & CLPIP_SHAKE))) {
810 			LP_PRINTF("&");
811 			if(++lp->sc_xmit_rtry > LPMAXRTRY) {
812 				aprint_error_dev(dev, "Too many retries while channel "
813 					"busy, going off-line.\n");
814 				ppbus_wctr(ppbus, ~IRQENABLE);
815 				if_down(ifp);
816 				lp->sc_xmit_rtry = 0;
817 			}
818 			goto final;
819 		}
820 		lp->sc_xmit_rtry = 0;
821 
822 		/* Disable interrupt generation */
823 		ppbus_wctr(ppbus, ~IRQENABLE);
824 
825 		err = 1;
826 
827 		/* Output packet for Linux/crynwyr compatible protocol */
828 		if(ifp->if_flags & IFF_LINK0) {
829 			/* Calculate packet length */
830 			count = 14;		/* Ethernet header len */
831 			for(mm = m; mm; mm = mm->m_next) {
832 				count += mm->m_len;
833 			}
834 
835 			/* Alert other end to pending packet */
836 			spin = LPMAXSPIN1;
837 			ppbus_wdtr(ppbus, 0x08);
838 			while((ppbus_rstr(ppbus) & 0x08) == 0) {
839 				if (--spin == 0) {
840 					goto nend;
841 				}
842 			}
843 
844 			if(clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
845 				goto nend;
846 			if(clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
847 				goto nend;
848 
849 			/* Send dummy ethernet header */
850 			chksum = 0;
851 			for(i = 0; i < 12; i++) {
852 				if(clpoutbyte(i, LPMAXSPIN1, ppbus))
853 					goto nend;
854 				chksum += i;
855 			}
856 
857 			if(clpoutbyte(0x08, LPMAXSPIN1, ppbus))
858 				goto nend;
859 			if(clpoutbyte(0x00, LPMAXSPIN1, ppbus))
860 				goto nend;
861 			chksum += 0x08 + 0x00;		/* Add into checksum */
862 
863 			mm = m;
864 			do {
865 				cp = mtod(mm, u_char *);
866 				len = mm->m_len;
867 				while(len--) {
868 					if(clpoutbyte(*cp, LPMAXSPIN2, ppbus))
869 						goto nend;
870 					chksum += *cp++;
871 				}
872 			} while ((mm = mm->m_next));
873 
874 			/* Send checksum */
875 			if(clpoutbyte(chksum, LPMAXSPIN2, ppbus))
876 				goto nend;
877 
878 			/* No errors */
879 			err = 0;
880 			/* Go quiescent */
881 			ppbus_wdtr(ppbus, 0);
882 		}
883 		/* Output packet for FreeBSD compatible protocol */
884 		else {
885 			/* We need a sensible value if we abort */
886 			cp = NULL;
887 
888 			if(lpoutbyte(0x08, LPMAXSPIN1, ppbus))
889 				goto end;
890 			if(lpoutbyte(0x00, LPMAXSPIN2, ppbus))
891 				goto end;
892 
893 			mm = m;
894 			do {
895 				cp = mtod(mm,u_char *);
896 				len = mm->m_len;
897 				while(len--)
898 					if(lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
899 						goto end;
900 			} while ((mm = mm->m_next));
901 
902 			/* no errors were encountered */
903 			err = 0;
904 
905 end:
906 			if(cp)
907 				ppbus_wdtr(ppbus, txmitl[*(--cp)] ^ 0x17);
908 			else
909 				ppbus_wdtr(ppbus, txmitl['\0'] ^ 0x17);
910 		}
911 
912 nend:
913 		/* Re-enable interrupt generation */
914 		ppbus_wctr(ppbus, IRQENABLE);
915 
916 		if(err) {
917 			/* Go quiescent */
918 			ppbus_wdtr(ppbus, 0);
919 
920 			ifp->if_oerrors++;
921 			lp->sc_iferrs++;
922 			LP_PRINTF("X");
923 
924 			/* Disable interface if there are too many errors */
925 			if(lp->sc_iferrs > LPMAXERRS) {
926 				aprint_error_dev(dev, "Too many errors, going off-line.\n");
927 				ppbus_wctr(ppbus, ~IRQENABLE);
928 				if_down(ifp);
929 				lp->sc_iferrs = 0;
930 				goto final;
931 			}
932 		}
933 		else {
934 			/* Dequeue packet on success */
935 			IFQ_DEQUEUE(&ifp->if_snd, m);
936 #if NBPFILTER > 0
937 			if(ifp->if_bpf)
938 				lptap(ifp, m);
939 #endif
940 			ifp->if_opackets++;
941 			ifp->if_obytes += m->m_pkthdr.len;
942 			m_freem(m);
943 		}
944 	}
945 
946 final:
947 	ifp->if_flags &= ~IFF_OACTIVE;
948 	return;
949 }
950