xref: /netbsd-src/sys/dev/ppbus/if_plip.c (revision 6cf6fe02a981b55727c49c3d37b0d8191a98c0ee)
1 /* $NetBSD: if_plip.c,v 1.25 2014/06/05 23:48:16 rmind 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 1.25 2014/06/05 23:48:16 rmind 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 
90 #include <sys/systm.h>
91 #include <sys/param.h>
92 #include <sys/proc.h>
93 #include <sys/types.h>
94 #include <sys/device.h>
95 #include <sys/ioctl.h>
96 #include <sys/malloc.h>
97 #include <sys/mbuf.h>
98 
99 #include <net/if.h>
100 #include <net/if_types.h>
101 #include <net/netisr.h>
102 
103 #include <sys/time.h>
104 #include <net/bpf.h>
105 
106 #ifdef INET
107 #include <netinet/in_var.h>
108 /* #include <netinet/in.h> */
109 #else
110 #error Cannot config lp/plip without inet
111 #endif
112 
113 #include <dev/ppbus/ppbus_base.h>
114 #include <dev/ppbus/ppbus_device.h>
115 #include <dev/ppbus/ppbus_io.h>
116 #include <dev/ppbus/ppbus_var.h>
117 
118 #include <machine/types.h>
119 #include <sys/intr.h>
120 
121 #ifndef LPMTU			/* MTU for the lp# interfaces */
122 #define	LPMTU		1500
123 #endif
124 
125 #ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
126 #define	LPMAXSPIN1	8000	/* Spinning for remote intr to happen */
127 #endif
128 
129 #ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
130 #define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
131 #endif
132 
133 #ifndef LPMAXERRS		/* Max errors before !RUNNING */
134 #define	LPMAXERRS	100
135 #endif
136 
137 #ifndef LPMAXRTRY
138 #define LPMAXRTRY	100	/* If channel busy, retry LPMAXRTRY
139 					consecutive times */
140 #endif
141 
142 #define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
143 #define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
144 #define MLPIPHDRLEN	CLPIPHDRLEN
145 
146 #define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
147 #define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
148 #if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
149 #define MLPIPHDRLEN	LPIPHDRLEN
150 #endif
151 
152 #define	LPIPTBLSIZE	256	/* Size of octet translation table */
153 
154 #define LP_PRINTF	if (lpflag) printf
155 
156 #ifdef PLIP_DEBUG
157 static int volatile lpflag = 1;
158 #else
159 static int volatile lpflag = 0;
160 #endif
161 
162 /* Tx/Rsv tables for the lp interface */
163 static u_char *txmith;
164 #define txmitl (txmith+(1*LPIPTBLSIZE))
165 #define trecvh (txmith+(2*LPIPTBLSIZE))
166 #define trecvl (txmith+(3*LPIPTBLSIZE))
167 static u_char *ctxmith;
168 #define ctxmitl (ctxmith+(1*LPIPTBLSIZE))
169 #define ctrecvh (ctxmith+(2*LPIPTBLSIZE))
170 #define ctrecvl (ctxmith+(3*LPIPTBLSIZE))
171 static uint16_t lp_count = 0;
172 
173 /* Autoconf functions */
174 static int lp_probe(device_t, cfdata_t, void *);
175 static void lp_attach(device_t, device_t, void *);
176 static int lp_detach(device_t, int);
177 
178 /* Soft config data */
179 struct lp_softc {
180 	struct ppbus_device_softc ppbus_dev;
181 	struct ifnet sc_if;
182 	u_char *sc_ifbuf;
183 	unsigned short sc_iferrs;
184 	unsigned short sc_xmit_rtry;
185 	u_int8_t sc_dev_ok; /* Zero means ok */
186 };
187 
188 /* Autoconf structure */
189 CFATTACH_DECL_NEW(plip, sizeof(struct lp_softc), lp_probe, lp_attach, lp_detach,
190 	NULL);
191 
192 /* Functions for the lp interface */
193 static void lpinittables(void);
194 static void lpfreetables(void);
195 static int lpioctl(struct ifnet *, u_long, void *);
196 static int lpoutput(struct ifnet *, struct mbuf *, const struct sockaddr *,
197 	struct rtentry *);
198 static void lpstart(struct ifnet *);
199 static void lp_intr(void *);
200 
201 
202 static int
203 lp_probe(device_t parent, cfdata_t match, void *aux)
204 {
205 	struct ppbus_attach_args * args = aux;
206 
207 	/* Fail if ppbus is not interrupt capable */
208 	if(args->capabilities & PPBUS_HAS_INTR)
209 		return 1;
210 
211 	printf("%s(%s): not an interrupt-driven port.\n", __func__,
212 		device_xname(parent));
213 	return 0;
214 }
215 
216 static void
217 lp_attach(device_t parent, device_t self, void *aux)
218 {
219 	struct lp_softc * lp = device_private(self);
220 	struct ifnet * ifp = &lp->sc_if;
221 
222 	lp->ppbus_dev.sc_dev = self;
223 	lp->sc_dev_ok = 0;
224 	lp->sc_ifbuf = NULL;
225 	lp->sc_iferrs = 0;
226 	lp->sc_xmit_rtry = 0;
227 
228 	ifp->if_softc = lp;
229 	strlcpy(ifp->if_xname, device_xname(self), IFNAMSIZ);
230 	ifp->if_mtu = LPMTU;
231 	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
232 	ifp->if_ioctl = lpioctl;
233 	ifp->if_output = lpoutput;
234 	ifp->if_start = lpstart;
235 	ifp->if_type = IFT_PARA;
236 	ifp->if_hdrlen = 0;
237 	ifp->if_addrlen = 0;
238 	ifp->if_dlt = DLT_NULL;
239 	IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN);
240 	IFQ_SET_READY(&ifp->if_snd);
241 	if_attach(ifp);
242 	if_alloc_sadl(ifp);
243 
244 	bpf_attach(ifp, DLT_NULL, sizeof(u_int32_t));
245 
246 	if(lp_count++ == 0)
247 		lpinittables();
248 	printf("\n");
249 }
250 
251 static int
252 lp_detach(device_t self, int flags)
253 {
254 	int error = 0;
255 	struct lp_softc * lp = device_private(self);
256 	device_t ppbus = device_parent(self);
257 
258 	if(lp->sc_dev_ok) {
259 		if(!(flags & DETACH_QUIET))
260 			LP_PRINTF("%s(%s): device not properly attached! "
261 				"Skipping detach....\n", __func__,
262 				device_xname(self));
263 		return error;
264 	}
265 
266 	/* If interface is up, bring it down and release ppbus */
267 	if(lp->sc_if.if_flags & IFF_RUNNING) {
268 		ppbus_wctr(ppbus, 0x00);
269 		if_detach(&lp->sc_if);
270 		error = ppbus_remove_handler(ppbus, lp_intr);
271 		if(error) {
272 			if(!(flags & DETACH_QUIET))
273 				LP_PRINTF("%s(%s): unable to remove interrupt "
274 					"callback.\n", __func__,
275 					device_xname(self));
276 			if(!(flags & DETACH_FORCE))
277 				return error;
278 		}
279 		error = ppbus_release_bus(ppbus, self, 0, 0);
280 		if(error) {
281 			if(!(flags & DETACH_QUIET))
282 				LP_PRINTF("%s(%s): error releasing bus %s.\n",
283 					__func__, device_xname(self),
284 					device_xname(ppbus));
285 			if(!(flags & DETACH_FORCE))
286 				return error;
287 		}
288 	}
289 
290 	if(lp->sc_ifbuf)
291 		free(lp->sc_ifbuf, M_DEVBUF);
292 
293 	if(--lp_count == 0)
294 		lpfreetables();
295 	return error;
296 }
297 
298 /*
299  * Build the translation tables for the LPIP (BSD unix) protocol.
300  * We don't want to calculate these nasties in our tight loop, so we
301  * precalculate them when we initialize.
302  */
303 static void
304 lpinittables (void)
305 {
306 	int i;
307 
308 	if (!txmith)
309 		txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_WAITOK);
310 
311 	if (!ctxmith)
312 		ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_WAITOK);
313 
314 	for(i = 0; i < LPIPTBLSIZE; i++) {
315 		ctxmith[i] = (i & 0xF0) >> 4;
316 		ctxmitl[i] = 0x10 | (i & 0x0F);
317 		ctrecvh[i] = (i & 0x78) << 1;
318 		ctrecvl[i] = (i & 0x78) >> 3;
319 	}
320 
321 	for(i = 0; i < LPIPTBLSIZE; i++) {
322 		txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
323 		txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
324 		trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
325 		trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
326 	}
327 }
328 
329 /* Free translation tables */
330 static void
331 lpfreetables (void)
332 {
333 	if (txmith)
334 		free(txmith, M_DEVBUF);
335 	if (ctxmith)
336 		free(ctxmith, M_DEVBUF);
337 	txmith = ctxmith = NULL;
338 }
339 
340 
341 /* Process an ioctl request. */
342 static int
343 lpioctl(struct ifnet *ifp, u_long cmd, void *data)
344 {
345 	struct lp_softc * sc = ifp->if_softc;
346 	device_t dev = sc->ppbus_dev.sc_dev;
347 	device_t ppbus = device_parent(dev);
348 	struct ifaddr * ifa = (struct ifaddr *)data;
349 	struct ifreq * ifr = (struct ifreq *)data;
350 	u_char * ptr;
351 	int error, s;
352 
353 	error = 0;
354 	s = splnet();
355 
356 	if(sc->sc_dev_ok) {
357 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
358 			device_xname(dev));
359 		error = ENODEV;
360 		goto end;
361 	}
362 
363 	switch (cmd) {
364 
365 	case SIOCSIFDSTADDR:
366 		if (ifa->ifa_addr->sa_family != AF_INET)
367 			error = EAFNOSUPPORT;
368 		break;
369 
370 	case SIOCINITIFADDR:
371 		if (ifa->ifa_addr->sa_family != AF_INET) {
372 			error = EAFNOSUPPORT;
373 			break;
374 		}
375 		ifp->if_flags |= IFF_UP;
376 	/* FALLTHROUGH */
377 	case SIOCSIFFLAGS:
378 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
379 			break;
380 		if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) == IFF_UP) {
381 			if((error = ppbus_request_bus(ppbus, dev, 0, 0)))
382 				break;
383 			error = ppbus_set_mode(ppbus, PPBUS_COMPATIBLE, 0);
384 			if(error)
385 				break;
386 
387 			error = ppbus_add_handler(ppbus, lp_intr, dev);
388 			if(error) {
389 				LP_PRINTF("%s(%s): unable to register interrupt"
390 					" callback.\n", __func__,
391 					device_xname(dev));
392 				ppbus_release_bus(ppbus, dev, 0, 0);
393 				break;
394 			}
395 
396 			/* Allocate a buffer if necessary */
397 			if(sc->sc_ifbuf == NULL) {
398 				sc->sc_ifbuf = malloc(sc->sc_if.if_mtu +
399 					MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
400 				if (!sc->sc_ifbuf) {
401 					error = ENOBUFS;
402 					ppbus_release_bus(ppbus, dev, 0, 0);
403 					break;
404 				}
405 			}
406 
407 			ppbus_wctr(ppbus, IRQENABLE);
408 			ifp->if_flags |= IFF_RUNNING;
409 		}
410 		if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) == IFF_RUNNING) {
411 			ppbus_remove_handler(ppbus, lp_intr);
412 			error = ppbus_release_bus(ppbus, dev, 0, 0);
413 			ifp->if_flags &= ~IFF_RUNNING;
414 		}
415 		/* Go quiescent */
416 		ppbus_wdtr(ppbus, 0);
417 		break;
418 
419 	case SIOCSIFMTU:
420 		if(sc->sc_if.if_mtu == ifr->ifr_mtu)
421 			break;
422 		ptr = sc->sc_ifbuf;
423 		sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF,
424 			M_NOWAIT);
425 		if (!sc->sc_ifbuf) {
426 			sc->sc_ifbuf = ptr;
427 			error = ENOBUFS;
428 			break;
429 		}
430 		if(ptr)
431 			free(ptr,M_DEVBUF);
432 		/*FALLTHROUGH*/
433 	case SIOCGIFMTU:
434 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
435 			error = 0;
436 		break;
437 
438 	case SIOCADDMULTI:
439 	case SIOCDELMULTI:
440 		if (ifr == NULL) {
441 			error = EAFNOSUPPORT;		/* XXX */
442 			break;
443 		}
444 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
445 		case AF_INET:
446 			break;
447 		default:
448 			return EAFNOSUPPORT;
449 		}
450 		break;
451 
452 	case SIOCGIFMEDIA:
453 		/*
454 		 * No ifmedia support at this stage; maybe use it
455 		 * in future for eg. protocol selection.
456 		 */
457 	default:
458 		LP_PRINTF("LP:ioctl(0x%lx)\n", cmd);
459 		error = ifioctl_common(ifp, cmd, data);
460 	}
461 
462 end:
463 	splx(s);
464 	return error;
465 }
466 
467 static inline int
468 clpoutbyte (u_char byte, int spin, device_t ppbus)
469 {
470 	int s = spin;
471 	ppbus_wdtr(ppbus, ctxmitl[byte]);
472 	while (ppbus_rstr(ppbus) & CLPIP_SHAKE) {
473 		if (--s == 0) {
474 			return 1;
475 		}
476 	}
477 	s = spin;
478 	ppbus_wdtr(ppbus, ctxmith[byte]);
479 	while (!(ppbus_rstr(ppbus) & CLPIP_SHAKE)) {
480 		if (--s == 0) {
481 			return 1;
482 		}
483 	}
484 	return 0;
485 }
486 
487 static inline int
488 clpinbyte (int spin, device_t ppbus)
489 {
490 	u_char c, cl;
491 	int s = spin;
492 
493 	while(ppbus_rstr(ppbus) & CLPIP_SHAKE) {
494 		if(!--s) {
495 			return -1;
496 		}
497 	}
498 	cl = ppbus_rstr(ppbus);
499 	ppbus_wdtr(ppbus, 0x10);
500 
501 	s = spin;
502 	while(!(ppbus_rstr(ppbus) & CLPIP_SHAKE)) {
503 		if(!--s) {
504 			return -1;
505 		}
506 	}
507 	c = ppbus_rstr(ppbus);
508 	ppbus_wdtr(ppbus, 0x00);
509 
510 	return (ctrecvl[cl] | ctrecvh[c]);
511 }
512 
513 static void
514 lptap(struct ifnet *ifp, struct mbuf *m)
515 {
516 	/*
517 	 * Send a packet through bpf. We need to prepend the address family
518 	 * as a four byte field. Cons up a dummy header to pacify bpf. This
519 	 * is safe because bpf will only read from the mbuf (i.e., it won't
520 	 * try to free it or keep a pointer to it).
521 	 */
522 	u_int32_t af = AF_INET;
523 	struct mbuf m0;
524 
525 	m0.m_next = m;
526 	m0.m_len = sizeof(u_int32_t);
527 	m0.m_data = (char *)&af;
528 	bpf_mtap(ifp, &m0);
529 }
530 
531 /* Soft interrupt handler called by hardware interrupt handler */
532 static void
533 lp_intr (void *arg)
534 {
535 	device_t dev = (device_t)arg;
536         device_t ppbus = device_parent(dev);
537 	struct lp_softc * sc = device_private(dev);
538 	struct ifnet * ifp = &sc->sc_if;
539 	struct mbuf *top;
540 	int len, s, j;
541 	u_char *bp;
542 	u_char c, cl;
543 
544 	s = splnet();
545 
546 	/* Do nothing if device not properly attached */
547 	if(sc->sc_dev_ok) {
548 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
549 			device_xname(dev));
550 		goto done;
551 	}
552 
553 	/* Do nothing if interface is not up */
554 	if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
555 		goto done;
556 
557 	/* If other side is no longer transmitting, do nothing */
558 	if(!(ppbus_rstr(ppbus) & LPIP_SHAKE))
559 		goto done;
560 
561 	/* Disable interrupts until we finish */
562 	ppbus_wctr(ppbus, ~IRQENABLE);
563 
564 	top = NULL;
565 	bp = sc->sc_ifbuf;
566 	/* Linux/crynwyr protocol receiving */
567 	if(ifp->if_flags & IFF_LINK0) {
568 		/* Ack. the request */
569 		ppbus_wdtr(ppbus, 0x01);
570 
571 		/* Get the packet length */
572 		j = clpinbyte(LPMAXSPIN2, ppbus);
573 		if(j == -1)
574 			goto err;
575 		len = j;
576 		j = clpinbyte(LPMAXSPIN2, ppbus);
577 		if(j == -1)
578 			goto err;
579 		len = len + (j << 8);
580 		if(len > ifp->if_mtu + MLPIPHDRLEN)
581 			goto err;
582 
583 		while(len--) {
584 			j = clpinbyte(LPMAXSPIN2, ppbus);
585 			if (j == -1) {
586 				goto err;
587 			}
588 			*bp++ = j;
589 		}
590 		/* Get and ignore checksum */
591 		j = clpinbyte(LPMAXSPIN2, ppbus);
592 		if(j == -1) {
593 			goto err;
594 		}
595 
596 		/* Return to idle state */
597 		ppbus_wdtr(ppbus, 0);
598 		len = bp - sc->sc_ifbuf;
599 		if (len <= CLPIPHDRLEN)
600 			goto err;
601 		len -= CLPIPHDRLEN;
602 		top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, ifp, NULL);
603 	}
604 	/* FreeBSD protocol receiving */
605 	else {
606 		len = ifp->if_mtu + LPIPHDRLEN;
607 		while(len--) {
608 			cl = ppbus_rstr(ppbus);
609 			ppbus_wdtr(ppbus, 0x08);
610 
611 			j = LPMAXSPIN2;
612 			while((ppbus_rstr(ppbus) & LPIP_SHAKE)) {
613 				if(!--j) goto err;
614 			}
615 
616 			c = ppbus_rstr(ppbus);
617 			ppbus_wdtr(ppbus, 0);
618 
619 			*bp++= trecvh[cl] | trecvl[c];
620 
621 			j = LPMAXSPIN2;
622 			while(!((cl=ppbus_rstr(ppbus)) & LPIP_SHAKE)) {
623 				if(cl != c &&
624 					(((cl = ppbus_rstr(ppbus)) ^ 0xb8) &
625 					0xf8) == (c & 0xf8))
626 					goto end;
627 				if(!--j) goto err;
628 			}
629 		}
630 
631 end:
632 		len = bp - sc->sc_ifbuf;
633 		if(len <= LPIPHDRLEN)
634 			goto err;
635 		len -= LPIPHDRLEN;
636 		top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, ifp, NULL);
637 	}
638 
639 	if (top == NULL) {
640 		ifp->if_iqdrops++;
641 		goto err;
642 	}
643 	if (ifp->if_bpf) {
644 		lptap(ifp, top);
645 	}
646 	if (__predict_false(!pktq_enqueue(ip_pktq, top, 0))) {
647 		ifp->if_iqdrops++;
648 		m_freem(top);
649 		goto err;
650 	}
651 	ifp->if_ipackets++;
652 	ifp->if_ibytes += len;
653 	sc->sc_iferrs = 0;
654 
655 	goto done;
656 
657 err:
658 	/* Return to idle state */
659 	ppbus_wdtr(ppbus, 0);
660 	ifp->if_ierrors++;
661 	sc->sc_iferrs++;
662 	LP_PRINTF("R");
663 	/* Disable interface if there are too many errors */
664 	if(sc->sc_iferrs > LPMAXERRS) {
665 		aprint_error_dev(dev, "Too many consecutive errors, going off-line.\n");
666 		ppbus_wctr(ppbus, ~IRQENABLE);
667 		if_down(ifp);
668 		sc->sc_iferrs = 0;
669 	}
670 
671 done:
672 	/* Re-enable interrupts */
673 	ppbus_wctr(ppbus, IRQENABLE);
674 	/* If interface is not active, send some packets */
675 	if((ifp->if_flags & IFF_OACTIVE) == 0)
676 		lpstart(ifp);
677 	splx(s);
678 	return;
679 }
680 
681 static inline int
682 lpoutbyte(u_char byte, int spin, device_t ppbus)
683 {
684 	int s = spin;
685 	ppbus_wdtr(ppbus, txmith[byte]);
686 	while(!(ppbus_rstr(ppbus) & LPIP_SHAKE)) {
687 		if(--s == 0)
688 			return 1;
689 	}
690 	s = spin;
691 	ppbus_wdtr(ppbus, txmitl[byte]);
692 	while(ppbus_rstr(ppbus) & LPIP_SHAKE) {
693 		if(--s == 0)
694 			return 1;
695 	}
696 	return 0;
697 }
698 
699 /* Queue a packet for delivery */
700 static int
701 lpoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
702 	struct rtentry *rt)
703 {
704 	struct lp_softc * sc = ifp->if_softc;
705 	device_t dev = sc->ppbus_dev.sc_dev;
706 	device_t ppbus = device_parent(dev);
707 	ALTQ_DECL(struct altq_pktattr pktattr;)
708 	int err;
709 	int s;
710 
711 	s = splnet();
712 
713 	if(sc->sc_dev_ok) {
714 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
715 			device_xname(dev));
716 		err = ENODEV;
717 		goto endoutput;
718 	}
719 
720 	if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
721 		err = ENETDOWN;
722 		goto endoutput;
723 	}
724 
725 	/* Only support INET */
726 	if(dst->sa_family != AF_INET) {
727 		LP_PRINTF("%s: af%d not supported\n", ifp->if_xname,
728 		    dst->sa_family);
729 		ifp->if_noproto++;
730 		err = EAFNOSUPPORT;
731 		goto endoutput;
732 	}
733 
734 	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
735 	IFQ_ENQUEUE(&ifp->if_snd, m, NULL, err);
736 	if(err == 0) {
737 		if((ifp->if_flags & IFF_OACTIVE) == 0)
738 			lpstart(ifp);
739 	}
740 	else {
741 		ifp->if_oerrors++;
742 		sc->sc_iferrs++;
743 		LP_PRINTF("Q");
744 
745 		/* Disable interface if there are too many errors */
746 		if(sc->sc_iferrs > LPMAXERRS) {
747 			aprint_error_dev(dev, "Too many errors, going off-line.\n");
748 			ppbus_wctr(ppbus, ~IRQENABLE);
749 			if_down(ifp);
750 			sc->sc_iferrs = 0;
751 		}
752 	}
753 
754 endoutput:
755 	if((err != 0) && (err != ENOBUFS))
756 		m_freem(m);
757 	splx(s);
758 	return err;
759 }
760 
761 /* Send routine: send packets over PLIP cable. Call at splnet(). */
762 void
763 lpstart(struct ifnet * ifp)
764 {
765 	struct lp_softc * lp = ifp->if_softc;
766 	device_t dev = lp->ppbus_dev.sc_dev;
767 	device_t ppbus = device_parent(dev);
768 	struct mbuf * mm;
769 	struct mbuf * m;
770 	u_char * cp;
771 	int err, i, len, spin, count;
772 	u_char str, chksum;
773 
774 	if(lp->sc_dev_ok) {
775 		LP_PRINTF("%s(%s): device not properly attached!", __func__,
776 			device_xname(dev));
777 		return;
778 	}
779 
780 	if((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
781 		return;
782 	}
783 
784 	ifp->if_flags |= IFF_OACTIVE;
785 
786 	/* Go quiescent */
787 	ppbus_wdtr(ppbus, 0);
788 
789 	/* Output loop */
790 	for(;;) {
791 		/* Check if there are packets to send */
792 		if(IFQ_IS_EMPTY(&ifp->if_snd)) {
793 			goto final;
794 		}
795 		/* Try to send a packet, dequeue it later if successful */
796 		IFQ_POLL(&ifp->if_snd, m);
797 		if(m == NULL)
798 			goto final;
799 
800 		str = ppbus_rstr(ppbus);
801 		/* Wait until other side is not transmitting */
802 		if((str & LPIP_SHAKE) ||
803 			((ifp->if_flags & IFF_LINK0) && !(str & CLPIP_SHAKE))) {
804 			LP_PRINTF("&");
805 			if(++lp->sc_xmit_rtry > LPMAXRTRY) {
806 				aprint_error_dev(dev, "Too many retries while channel "
807 					"busy, going off-line.\n");
808 				ppbus_wctr(ppbus, ~IRQENABLE);
809 				if_down(ifp);
810 				lp->sc_xmit_rtry = 0;
811 			}
812 			goto final;
813 		}
814 		lp->sc_xmit_rtry = 0;
815 
816 		/* Disable interrupt generation */
817 		ppbus_wctr(ppbus, ~IRQENABLE);
818 
819 		err = 1;
820 
821 		/* Output packet for Linux/crynwyr compatible protocol */
822 		if(ifp->if_flags & IFF_LINK0) {
823 			/* Calculate packet length */
824 			count = 14;		/* Ethernet header len */
825 			for(mm = m; mm; mm = mm->m_next) {
826 				count += mm->m_len;
827 			}
828 
829 			/* Alert other end to pending packet */
830 			spin = LPMAXSPIN1;
831 			ppbus_wdtr(ppbus, 0x08);
832 			while((ppbus_rstr(ppbus) & 0x08) == 0) {
833 				if (--spin == 0) {
834 					goto nend;
835 				}
836 			}
837 
838 			if(clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
839 				goto nend;
840 			if(clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
841 				goto nend;
842 
843 			/* Send dummy ethernet header */
844 			chksum = 0;
845 			for(i = 0; i < 12; i++) {
846 				if(clpoutbyte(i, LPMAXSPIN1, ppbus))
847 					goto nend;
848 				chksum += i;
849 			}
850 
851 			if(clpoutbyte(0x08, LPMAXSPIN1, ppbus))
852 				goto nend;
853 			if(clpoutbyte(0x00, LPMAXSPIN1, ppbus))
854 				goto nend;
855 			chksum += 0x08 + 0x00;		/* Add into checksum */
856 
857 			mm = m;
858 			do {
859 				cp = mtod(mm, u_char *);
860 				len = mm->m_len;
861 				while(len--) {
862 					if(clpoutbyte(*cp, LPMAXSPIN2, ppbus))
863 						goto nend;
864 					chksum += *cp++;
865 				}
866 			} while ((mm = mm->m_next));
867 
868 			/* Send checksum */
869 			if(clpoutbyte(chksum, LPMAXSPIN2, ppbus))
870 				goto nend;
871 
872 			/* No errors */
873 			err = 0;
874 			/* Go quiescent */
875 			ppbus_wdtr(ppbus, 0);
876 		}
877 		/* Output packet for FreeBSD compatible protocol */
878 		else {
879 			/* We need a sensible value if we abort */
880 			cp = NULL;
881 
882 			if(lpoutbyte(0x08, LPMAXSPIN1, ppbus))
883 				goto end;
884 			if(lpoutbyte(0x00, LPMAXSPIN2, ppbus))
885 				goto end;
886 
887 			mm = m;
888 			do {
889 				cp = mtod(mm,u_char *);
890 				len = mm->m_len;
891 				while(len--)
892 					if(lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
893 						goto end;
894 			} while ((mm = mm->m_next));
895 
896 			/* no errors were encountered */
897 			err = 0;
898 
899 end:
900 			if(cp)
901 				ppbus_wdtr(ppbus, txmitl[*(--cp)] ^ 0x17);
902 			else
903 				ppbus_wdtr(ppbus, txmitl['\0'] ^ 0x17);
904 		}
905 
906 nend:
907 		/* Re-enable interrupt generation */
908 		ppbus_wctr(ppbus, IRQENABLE);
909 
910 		if(err) {
911 			/* Go quiescent */
912 			ppbus_wdtr(ppbus, 0);
913 
914 			ifp->if_oerrors++;
915 			lp->sc_iferrs++;
916 			LP_PRINTF("X");
917 
918 			/* Disable interface if there are too many errors */
919 			if(lp->sc_iferrs > LPMAXERRS) {
920 				aprint_error_dev(dev, "Too many errors, going off-line.\n");
921 				ppbus_wctr(ppbus, ~IRQENABLE);
922 				if_down(ifp);
923 				lp->sc_iferrs = 0;
924 				goto final;
925 			}
926 		}
927 		else {
928 			/* Dequeue packet on success */
929 			IFQ_DEQUEUE(&ifp->if_snd, m);
930 			if(ifp->if_bpf)
931 				lptap(ifp, m);
932 			ifp->if_opackets++;
933 			ifp->if_obytes += m->m_pkthdr.len;
934 			m_freem(m);
935 		}
936 	}
937 
938 final:
939 	ifp->if_flags &= ~IFF_OACTIVE;
940 	return;
941 }
942