xref: /netbsd-src/sys/dev/ppbus/if_plip.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /* $NetBSD: if_plip.c,v 1.5 2004/02/10 21:55:38 jdolecek 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 1.5 2004/02/10 21:55:38 jdolecek 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 <machine/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(struct device *, struct cfdata *, void *);
178 static void lp_attach(struct device *, struct device *, void *);
179 static int lp_detach(struct device *, 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(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, caddr_t);
199 static int lpoutput(struct ifnet *, struct mbuf *, 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(struct device * parent, struct cfdata * 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 		parent->dv_xname);
216 	return 0;
217 }
218 
219 static void
220 lp_attach(struct device * parent, struct device * self, void * aux)
221 {
222 	struct lp_softc * lp = (struct lp_softc *) self;
223 	struct ifnet * ifp = &lp->sc_if;
224 
225 	lp->sc_dev_ok = 0;
226 	lp->sc_ifbuf = NULL;
227 	lp->sc_iferrs = 0;
228 	lp->sc_xmit_rtry = 0;
229 
230 	ifp->if_softc = self;
231 	strncpy(ifp->if_xname, self->dv_xname, IFNAMSIZ);
232 	ifp->if_xname[IFNAMSIZ - 1] = '\0';
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(struct device * self, int flags)
258 {
259 	int error = 0;
260 	struct lp_softc * lp = (struct lp_softc *) self;
261 	struct device * ppbus = self->dv_parent;
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 				self->dv_xname);
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 					self->dv_xname);
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__, self->dv_xname,
289 					ppbus->dv_xname);
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, caddr_t data)
349 {
350 	struct device * dev = ifp->if_softc;
351 	struct device * ppbus = dev->dv_parent;
352 	struct lp_softc * sc = (struct lp_softc *) 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 			dev->dv_xname);
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 					dev->dv_xname);
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 		sc->sc_if.if_mtu = ifr->ifr_mtu;
436 		break;
437 
438 	case SIOCGIFMTU:
439 		ifr->ifr_mtu = sc->sc_if.if_mtu;
440 		break;
441 
442 	case SIOCADDMULTI:
443 	case SIOCDELMULTI:
444 		if (ifr == NULL) {
445 			error = EAFNOSUPPORT;		/* XXX */
446 			break;
447 		}
448 		switch (ifr->ifr_addr.sa_family) {
449 		case AF_INET:
450 			break;
451 		default:
452 			return EAFNOSUPPORT;
453 		}
454 		break;
455 
456 	case SIOCGIFMEDIA:
457 		/*
458 		 * No ifmedia support at this stage; maybe use it
459 		 * in future for eg. protocol selection.
460 		 */
461 	default:
462 		LP_PRINTF("LP:ioctl(0x%lx)\n", cmd);
463 		error = EINVAL;
464 	}
465 
466 end:
467 	splx(s);
468 	return error;
469 }
470 
471 static __inline int
472 clpoutbyte (u_char byte, int spin, struct device * ppbus)
473 {
474 	int s = spin;
475 	ppbus_wdtr(ppbus, ctxmitl[byte]);
476 	while (ppbus_rstr(ppbus) & CLPIP_SHAKE) {
477 		if (--s == 0) {
478 			return 1;
479 		}
480 	}
481 	s = spin;
482 	ppbus_wdtr(ppbus, ctxmith[byte]);
483 	while (!(ppbus_rstr(ppbus) & CLPIP_SHAKE)) {
484 		if (--s == 0) {
485 			return 1;
486 		}
487 	}
488 	return 0;
489 }
490 
491 static __inline int
492 clpinbyte (int spin, struct device * ppbus)
493 {
494 	u_char c, cl;
495 	int s = spin;
496 
497 	while(ppbus_rstr(ppbus) & CLPIP_SHAKE) {
498 		if(!--s) {
499 			return -1;
500 		}
501 	}
502 	cl = ppbus_rstr(ppbus);
503 	ppbus_wdtr(ppbus, 0x10);
504 
505 	s = spin;
506 	while(!(ppbus_rstr(ppbus) & CLPIP_SHAKE)) {
507 		if(!--s) {
508 			return -1;
509 		}
510 	}
511 	c = ppbus_rstr(ppbus);
512 	ppbus_wdtr(ppbus, 0x00);
513 
514 	return (ctrecvl[cl] | ctrecvh[c]);
515 }
516 
517 #if NBPFILTER > 0
518 static void
519 lptap(struct ifnet *ifp, struct mbuf *m)
520 {
521 	/*
522 	 * Send a packet through bpf. We need to prepend the address family
523 	 * as a four byte field. Cons up a dummy header to pacify bpf. This
524 	 * is safe because bpf will only read from the mbuf (i.e., it won't
525 	 * try to free it or keep a pointer to it).
526 	 */
527 	u_int32_t af = AF_INET;
528 	struct mbuf m0;
529 
530 	m0.m_next = m;
531 	m0.m_len = sizeof(u_int32_t);
532 	m0.m_data = (char *)&af;
533 	bpf_mtap(ifp->if_bpf, &m0);
534 }
535 #endif
536 
537 /* Soft interrupt handler called by hardware interrupt handler */
538 static void
539 lp_intr (void *arg)
540 {
541 	struct device * dev = (struct device *)arg;
542         struct device * ppbus = dev->dv_parent;
543 	struct lp_softc * sc = (struct lp_softc *)dev;
544 	struct ifnet * ifp = &sc->sc_if;
545 	struct mbuf *top;
546 	int len, s, j;
547 	u_char *bp;
548 	u_char c, cl;
549 
550 	s = splnet();
551 
552 	/* Do nothing if device not properly attached */
553 	if(sc->sc_dev_ok) {
554 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
555 			dev->dv_xname);
556 		goto done;
557 	}
558 
559 	/* Do nothing if interface is not up */
560 	if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
561 		goto done;
562 
563 	/* If other side is no longer transmitting, do nothing */
564 	if(!(ppbus_rstr(ppbus) & LPIP_SHAKE))
565 		goto done;
566 
567 	/* Disable interrupts until we finish */
568 	ppbus_wctr(ppbus, ~IRQENABLE);
569 
570 	top = NULL;
571 	bp = sc->sc_ifbuf;
572 	/* Linux/crynwyr protocol receiving */
573 	if(ifp->if_flags & IFF_LINK0) {
574 		/* Ack. the request */
575 		ppbus_wdtr(ppbus, 0x01);
576 
577 		/* Get the packet length */
578 		j = clpinbyte(LPMAXSPIN2, ppbus);
579 		if(j == -1)
580 			goto err;
581 		len = j;
582 		j = clpinbyte(LPMAXSPIN2, ppbus);
583 		if(j == -1)
584 			goto err;
585 		len = len + (j << 8);
586 		if(len > ifp->if_mtu + MLPIPHDRLEN)
587 			goto err;
588 
589 		while(len--) {
590 			j = clpinbyte(LPMAXSPIN2, ppbus);
591 			if (j == -1) {
592 				goto err;
593 			}
594 			*bp++ = j;
595 		}
596 		/* Get and ignore checksum */
597 		j = clpinbyte(LPMAXSPIN2, ppbus);
598 		if(j == -1) {
599 			goto err;
600 		}
601 
602 		/* Return to idle state */
603 		ppbus_wdtr(ppbus, 0);
604 		len = bp - sc->sc_ifbuf;
605 		if (len <= CLPIPHDRLEN)
606 			goto err;
607 		len -= CLPIPHDRLEN;
608 		top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, ifp, NULL);
609 	}
610 	/* FreeBSD protocol receiving */
611 	else {
612 		len = ifp->if_mtu + LPIPHDRLEN;
613 		while(len--) {
614 			cl = ppbus_rstr(ppbus);
615 			ppbus_wdtr(ppbus, 0x08);
616 
617 			j = LPMAXSPIN2;
618 			while((ppbus_rstr(ppbus) & LPIP_SHAKE)) {
619 				if(!--j) goto err;
620 			}
621 
622 			c = ppbus_rstr(ppbus);
623 			ppbus_wdtr(ppbus, 0);
624 
625 			*bp++= trecvh[cl] | trecvl[c];
626 
627 			j = LPMAXSPIN2;
628 			while(!((cl=ppbus_rstr(ppbus)) & LPIP_SHAKE)) {
629 				if(cl != c &&
630 					(((cl = ppbus_rstr(ppbus)) ^ 0xb8) &
631 					0xf8) == (c & 0xf8))
632 					goto end;
633 				if(!--j) goto err;
634 			}
635 		}
636 
637 end:
638 		len = bp - sc->sc_ifbuf;
639 		if(len <= LPIPHDRLEN)
640 			goto err;
641 		len -= LPIPHDRLEN;
642 		top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, ifp, NULL);
643 	}
644 
645 	/* Do nothing if mbuf was not created or the queue is full */
646 	if((top == NULL) || (IF_QFULL(&ipintrq))) {
647 		IF_DROP(&ipintrq);
648 		ifp->if_iqdrops++;
649 		LP_PRINTF("DROP");
650 		goto err;
651 	}
652 #if NBPFILTER > 0
653 	if(ifp->if_bpf)
654 		lptap(ifp, top);
655 #endif
656 	IF_ENQUEUE(&ipintrq, top);
657 	schednetisr(NETISR_IP);
658 	ifp->if_ipackets++;
659 	ifp->if_ibytes += len;
660 	sc->sc_iferrs = 0;
661 
662 	goto done;
663 
664 err:
665 	/* Return to idle state */
666 	ppbus_wdtr(ppbus, 0);
667 	ifp->if_ierrors++;
668 	sc->sc_iferrs++;
669 	LP_PRINTF("R");
670 	/* Disable interface if there are too many errors */
671 	if(sc->sc_iferrs > LPMAXERRS) {
672 		printf("%s: Too many consecutive errors, going off-line.\n",
673 			dev->dv_xname);
674 		ppbus_wctr(ppbus, ~IRQENABLE);
675 		if_down(ifp);
676 		sc->sc_iferrs = 0;
677 	}
678 
679 done:
680 	/* Re-enable interrupts */
681 	ppbus_wctr(ppbus, IRQENABLE);
682 	/* If interface is not active, send some packets */
683 	if((ifp->if_flags & IFF_OACTIVE) == 0)
684 		lpstart(ifp);
685 	splx(s);
686 	return;
687 }
688 
689 static __inline int
690 lpoutbyte(u_char byte, int spin, struct device * ppbus)
691 {
692 	int s = spin;
693 	ppbus_wdtr(ppbus, txmith[byte]);
694 	while(!(ppbus_rstr(ppbus) & LPIP_SHAKE)) {
695 		if(--s == 0)
696 			return 1;
697 	}
698 	s = spin;
699 	ppbus_wdtr(ppbus, txmitl[byte]);
700 	while(ppbus_rstr(ppbus) & LPIP_SHAKE) {
701 		if(--s == 0)
702 			return 1;
703 	}
704 	return 0;
705 }
706 
707 /* Queue a packet for delivery */
708 static int
709 lpoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
710 	struct rtentry *rt)
711 {
712 	struct device * dev = ifp->if_softc;
713 	struct device * ppbus = dev->dv_parent;
714 	struct lp_softc * sc = (struct lp_softc *) dev;
715 	ALTQ_DECL(struct altq_pktattr pktattr;)
716 	int err;
717 	int s;
718 
719 	s = splnet();
720 
721 	if(sc->sc_dev_ok) {
722 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
723 			dev->dv_xname);
724 		err = ENODEV;
725 		goto endoutput;
726 	}
727 
728 	if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
729 		err = ENETDOWN;
730 		goto endoutput;
731 	}
732 
733 	/* Only support INET */
734 	if(dst->sa_family != AF_INET) {
735 		LP_PRINTF("%s: af%d not supported\n", ifp->if_xname,
736 		    dst->sa_family);
737 		ifp->if_noproto++;
738 		err = EAFNOSUPPORT;
739 		goto endoutput;
740 	}
741 
742 	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
743 	IFQ_ENQUEUE(&ifp->if_snd, m, dst->sa_family, err);
744 	if(err == 0) {
745 		if((ifp->if_flags & IFF_OACTIVE) == 0)
746 			lpstart(ifp);
747 	}
748 	else {
749 		ifp->if_oerrors++;
750 		sc->sc_iferrs++;
751 		LP_PRINTF("Q");
752 
753 		/* Disable interface if there are too many errors */
754 		if(sc->sc_iferrs > LPMAXERRS) {
755 			printf("%s: Too many errors, going off-line.\n",
756 				dev->dv_xname);
757 			ppbus_wctr(ppbus, ~IRQENABLE);
758 			if_down(ifp);
759 			sc->sc_iferrs = 0;
760 		}
761 	}
762 
763 endoutput:
764 	if((err != 0) && (err != ENOBUFS))
765 		m_freem(m);
766 	splx(s);
767 	return err;
768 }
769 
770 /* Send routine: send packets over PLIP cable. Call at splnet(). */
771 void
772 lpstart(struct ifnet * ifp)
773 {
774 	struct lp_softc * lp = ifp->if_softc;
775 	struct device * dev = ifp->if_softc;
776 	struct device * ppbus = dev->dv_parent;
777 	struct mbuf * mm;
778 	struct mbuf * m;
779 	u_char * cp;
780 	int err, i, len, spin, count;
781 	u_char str, chksum;
782 
783 	if(lp->sc_dev_ok) {
784 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
785 			dev->dv_xname);
786 		return;
787 	}
788 
789 	if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
790 		return;
791 	}
792 
793 	ifp->if_flags |= IFF_OACTIVE;
794 
795 	/* Go quiescent */
796 	ppbus_wdtr(ppbus, 0);
797 
798 	/* Output loop */
799 	for(;;) {
800 		/* Check if there are packets to send */
801 		if(IFQ_IS_EMPTY(&ifp->if_snd)) {
802 			goto final;
803 		}
804 		/* Try to send a packet, dequeue it later if successful */
805 		IFQ_POLL(&ifp->if_snd, m);
806 		if(m == NULL)
807 			goto final;
808 
809 		str = ppbus_rstr(ppbus);
810 		/* Wait until other side is not transmitting */
811 		if((str & LPIP_SHAKE) ||
812 			((ifp->if_flags & IFF_LINK0) && !(str & CLPIP_SHAKE))) {
813 			LP_PRINTF("&");
814 			if(++lp->sc_xmit_rtry > LPMAXRTRY) {
815 				printf("%s: Too many retries while channel "
816 					"busy, going off-line.\n",
817 					dev->dv_xname);
818 				ppbus_wctr(ppbus, ~IRQENABLE);
819 				if_down(ifp);
820 				lp->sc_xmit_rtry = 0;
821 			}
822 			goto final;
823 		}
824 		lp->sc_xmit_rtry = 0;
825 
826 		/* Disable interrupt generation */
827 		ppbus_wctr(ppbus, ~IRQENABLE);
828 
829 		err = 1;
830 
831 		/* Output packet for Linux/crynwyr compatible protocol */
832 		if(ifp->if_flags & IFF_LINK0) {
833 			/* Calculate packet length */
834 			count = 14;		/* Ethernet header len */
835 			for(mm = m; mm; mm = mm->m_next) {
836 				count += mm->m_len;
837 			}
838 
839 			/* Alert other end to pending packet */
840 			spin = LPMAXSPIN1;
841 			ppbus_wdtr(ppbus, 0x08);
842 			while((ppbus_rstr(ppbus) & 0x08) == 0) {
843 				if (--spin == 0) {
844 					goto nend;
845 				}
846 			}
847 
848 			if(clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
849 				goto nend;
850 			if(clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
851 				goto nend;
852 
853 			/* Send dummy ethernet header */
854 			chksum = 0;
855 			for(i = 0; i < 12; i++) {
856 				if(clpoutbyte(i, LPMAXSPIN1, ppbus))
857 					goto nend;
858 				chksum += i;
859 			}
860 
861 			if(clpoutbyte(0x08, LPMAXSPIN1, ppbus))
862 				goto nend;
863 			if(clpoutbyte(0x00, LPMAXSPIN1, ppbus))
864 				goto nend;
865 			chksum += 0x08 + 0x00;		/* Add into checksum */
866 
867 			mm = m;
868 			do {
869 				cp = mtod(mm, u_char *);
870 				len = mm->m_len;
871 				while(len--) {
872 					if(clpoutbyte(*cp, LPMAXSPIN2, ppbus))
873 						goto nend;
874 					chksum += *cp++;
875 				}
876 			} while ((mm = mm->m_next));
877 
878 			/* Send checksum */
879 			if(clpoutbyte(chksum, LPMAXSPIN2, ppbus))
880 				goto nend;
881 
882 			/* No errors */
883 			err = 0;
884 			/* Go quiescent */
885 			ppbus_wdtr(ppbus, 0);
886 		}
887 		/* Output packet for FreeBSD compatible protocol */
888 		else {
889 			/* We need a sensible value if we abort */
890 			cp = NULL;
891 
892 			if(lpoutbyte(0x08, LPMAXSPIN1, ppbus))
893 				goto end;
894 			if(lpoutbyte(0x00, LPMAXSPIN2, ppbus))
895 				goto end;
896 
897 			mm = m;
898 			do {
899 				cp = mtod(mm,u_char *);
900 				len = mm->m_len;
901 				while(len--)
902 					if(lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
903 						goto end;
904 			} while ((mm = mm->m_next));
905 
906 			/* no errors were encountered */
907 			err = 0;
908 
909 end:
910 			if(cp)
911 				ppbus_wdtr(ppbus, txmitl[*(--cp)] ^ 0x17);
912 			else
913 				ppbus_wdtr(ppbus, txmitl['\0'] ^ 0x17);
914 		}
915 
916 nend:
917 		/* Re-enable interrupt generation */
918 		ppbus_wctr(ppbus, IRQENABLE);
919 
920 		if(err) {
921 			/* Go quiescent */
922 			ppbus_wdtr(ppbus, 0);
923 
924 			ifp->if_oerrors++;
925 			lp->sc_iferrs++;
926 			LP_PRINTF("X");
927 
928 			/* Disable interface if there are too many errors */
929 			if(lp->sc_iferrs > LPMAXERRS) {
930 				printf("%s: Too many errors, going off-line.\n",
931 					dev->dv_xname);
932 				ppbus_wctr(ppbus, ~IRQENABLE);
933 				if_down(ifp);
934 				lp->sc_iferrs = 0;
935 				goto final;
936 			}
937 		}
938 		else {
939 			/* Dequeue packet on success */
940 			IFQ_DEQUEUE(&ifp->if_snd, m);
941 #if NBPFILTER > 0
942 			if(ifp->if_bpf)
943 				lptap(ifp, m);
944 #endif
945 			ifp->if_opackets++;
946 			ifp->if_obytes += m->m_pkthdr.len;
947 			m_freem(m);
948 		}
949 	}
950 
951 final:
952 	ifp->if_flags &= ~IFF_OACTIVE;
953 	return;
954 }
955