if_plip.c revision 59391 
1/*-
2 * Copyright (c) 1997 Poul-Henning Kamp
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 *	From Id: lpt.c,v 1.55.2.1 1996/11/12 09:08:38 phk Exp
27 * $FreeBSD: head/sys/dev/ppbus/if_plip.c 59391 2000-04-19 14:58:28Z phk $
28 */
29
30/*
31 * Parallel port TCP/IP interfaces added.  I looked at the driver from
32 * MACH but this is a complete rewrite, and btw. incompatible, and it
33 * should perform better too.  I have never run the MACH driver though.
34 *
35 * This driver sends two bytes (0x08, 0x00) in front of each packet,
36 * to allow us to distinguish another format later.
37 *
38 * Now added an Linux/Crynwr compatibility mode which is enabled using
39 * IF_LINK0 - Tim Wilkinson.
40 *
41 * TODO:
42 *    Make HDLC/PPP mode, use IF_LLC1 to enable.
43 *
44 * Connect the two computers using a Laplink parallel cable to use this
45 * feature:
46 *
47 *      +----------------------------------------+
48 * 	|A-name	A-End	B-End	Descr.	Port/Bit |
49 *      +----------------------------------------+
50 *	|DATA0	2	15	Data	0/0x01   |
51 *	|-ERROR	15	2	   	1/0x08   |
52 *      +----------------------------------------+
53 *	|DATA1	3	13	Data	0/0x02	 |
54 *	|+SLCT	13	3	   	1/0x10   |
55 *      +----------------------------------------+
56 *	|DATA2	4	12	Data	0/0x04   |
57 *	|+PE	12	4	   	1/0x20   |
58 *      +----------------------------------------+
59 *	|DATA3	5	10	Strobe	0/0x08   |
60 *	|-ACK	10	5	   	1/0x40   |
61 *      +----------------------------------------+
62 *	|DATA4	6	11	Data	0/0x10   |
63 *	|BUSY	11	6	   	1/~0x80  |
64 *      +----------------------------------------+
65 *	|GND	18-25	18-25	GND	-        |
66 *      +----------------------------------------+
67 *
68 * Expect transfer-rates up to 75 kbyte/sec.
69 *
70 * If GCC could correctly grok
71 *	register int port asm("edx")
72 * the code would be cleaner
73 *
74 * Poul-Henning Kamp <phk@freebsd.org>
75 */
76
77/*
78 * Update for ppbus, PLIP support only - Nicolas Souchu
79 */
80
81#include "opt_plip.h"
82
83#include <sys/param.h>
84#include <sys/systm.h>
85#include <sys/module.h>
86#include <sys/bus.h>
87#include <sys/mbuf.h>
88#include <sys/socket.h>
89#include <sys/sockio.h>
90#include <sys/kernel.h>
91#include <sys/malloc.h>
92
93#include <machine/clock.h>
94#include <machine/bus.h>
95#include <machine/resource.h>
96#include <sys/rman.h>
97
98#include <net/if.h>
99#include <net/if_types.h>
100#include <net/netisr.h>
101
102#include <netinet/in.h>
103#include <netinet/in_var.h>
104
105#include <net/bpf.h>
106
107#include <dev/ppbus/ppbconf.h>
108#include "ppbus_if.h"
109#include <dev/ppbus/ppbio.h>
110
111#ifndef LPMTU			/* MTU for the lp# interfaces */
112#define	LPMTU	1500
113#endif
114
115#ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
116#define	LPMAXSPIN1	8000   /* Spinning for remote intr to happen */
117#endif
118
119#ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
120#define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
121#endif
122
123#ifndef LPMAXERRS		/* Max errors before !RUNNING */
124#define	LPMAXERRS	100
125#endif
126
127#define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
128#define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
129#define MLPIPHDRLEN	CLPIPHDRLEN
130
131#define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
132#define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
133#if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
134#define MLPIPHDRLEN	LPIPHDRLEN
135#endif
136
137#define	LPIPTBLSIZE	256	/* Size of octet translation table */
138
139#define lprintf		if (lptflag) printf
140
141#ifdef PLIP_DEBUG
142static int volatile lptflag = 1;
143#else
144static int volatile lptflag = 0;
145#endif
146
147struct lp_data {
148	unsigned short lp_unit;
149
150	struct  ifnet	sc_if;
151	u_char		*sc_ifbuf;
152	int		sc_iferrs;
153
154	struct resource *res_irq;
155};
156
157/* Tables for the lp# interface */
158static u_char *txmith;
159#define txmitl (txmith+(1*LPIPTBLSIZE))
160#define trecvh (txmith+(2*LPIPTBLSIZE))
161#define trecvl (txmith+(3*LPIPTBLSIZE))
162
163static u_char *ctxmith;
164#define ctxmitl (ctxmith+(1*LPIPTBLSIZE))
165#define ctrecvh (ctxmith+(2*LPIPTBLSIZE))
166#define ctrecvl (ctxmith+(3*LPIPTBLSIZE))
167
168/* Functions for the lp# interface */
169static int lpinittables(void);
170static int lpioctl(struct ifnet *, u_long, caddr_t);
171static int lpoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
172	struct rtentry *);
173static void lp_intr(void *);
174
175#define DEVTOSOFTC(dev) \
176	((struct lp_data *)device_get_softc(dev))
177#define UNITOSOFTC(unit) \
178	((struct lp_data *)devclass_get_softc(lp_devclass, (unit)))
179#define UNITODEVICE(unit) \
180	(devclass_get_device(lp_devclass, (unit)))
181
182static devclass_t lp_devclass;
183
184static void
185lp_identify(driver_t *driver, device_t parent)
186{
187
188	BUS_ADD_CHILD(parent, 0, "plip", 0);
189}
190/*
191 * lpprobe()
192 */
193static int
194lp_probe(device_t dev)
195{
196	device_t ppbus = device_get_parent(dev);
197	struct lp_data *lp;
198	int zero = 0;
199	uintptr_t irq;
200
201	lp = DEVTOSOFTC(dev);
202	bzero(lp, sizeof(struct lp_data));
203
204	/* retrieve the ppbus irq */
205	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
206
207	/* if we haven't interrupts, the probe fails */
208	if (irq == -1) {
209		device_printf(dev, "not an interrupt driven port, failed.\n");
210		return (ENXIO);
211	}
212
213	/* reserve the interrupt resource, expecting irq is available to continue */
214	lp->res_irq = bus_alloc_resource(dev, SYS_RES_IRQ, &zero, irq, irq, 1,
215					 RF_SHAREABLE);
216	if (lp->res_irq == 0) {
217		device_printf(dev, "cannot reserve interrupt, failed.\n");
218		return (ENXIO);
219	}
220
221	/*
222	 * lp dependent initialisation.
223	 */
224	lp->lp_unit = device_get_unit(dev);
225
226	device_set_desc(dev, "PLIP network interface");
227
228	return (0);
229}
230
231static int
232lp_attach (device_t dev)
233{
234	struct lp_data *lp = DEVTOSOFTC(dev);
235	struct ifnet *ifp = &lp->sc_if;
236
237	ifp->if_softc = lp;
238	ifp->if_name = "lp";
239	ifp->if_unit = device_get_unit(dev);
240	ifp->if_mtu = LPMTU;
241	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
242	ifp->if_ioctl = lpioctl;
243	ifp->if_output = lpoutput;
244	ifp->if_type = IFT_PARA;
245	ifp->if_hdrlen = 0;
246	ifp->if_addrlen = 0;
247	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
248	if_attach(ifp);
249
250	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
251
252	return (0);
253}
254/*
255 * Build the translation tables for the LPIP (BSD unix) protocol.
256 * We don't want to calculate these nasties in our tight loop, so we
257 * precalculate them when we initialize.
258 */
259static int
260lpinittables (void)
261{
262    int i;
263
264    if (!txmith)
265	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
266
267    if (!txmith)
268	return 1;
269
270    if (!ctxmith)
271	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
272
273    if (!ctxmith)
274	return 1;
275
276    for (i=0; i < LPIPTBLSIZE; i++) {
277	ctxmith[i] = (i & 0xF0) >> 4;
278	ctxmitl[i] = 0x10 | (i & 0x0F);
279	ctrecvh[i] = (i & 0x78) << 1;
280	ctrecvl[i] = (i & 0x78) >> 3;
281    }
282
283    for (i=0; i < LPIPTBLSIZE; i++) {
284	txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
285	txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
286	trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
287	trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
288    }
289
290    return 0;
291}
292
293/*
294 * Process an ioctl request.
295 */
296
297static int
298lpioctl (struct ifnet *ifp, u_long cmd, caddr_t data)
299{
300    device_t dev = UNITODEVICE(ifp->if_unit);
301    device_t ppbus = device_get_parent(dev);
302    struct lp_data *sc = DEVTOSOFTC(dev);
303    struct ifaddr *ifa = (struct ifaddr *)data;
304    struct ifreq *ifr = (struct ifreq *)data;
305    u_char *ptr;
306    void *ih;
307    int error;
308
309    switch (cmd) {
310
311    case SIOCSIFDSTADDR:
312    case SIOCAIFADDR:
313    case SIOCSIFADDR:
314	if (ifa->ifa_addr->sa_family != AF_INET)
315	    return EAFNOSUPPORT;
316
317	ifp->if_flags |= IFF_UP;
318	/* FALLTHROUGH */
319    case SIOCSIFFLAGS:
320	if ((!(ifp->if_flags & IFF_UP)) && (ifp->if_flags & IFF_RUNNING)) {
321
322	    ppb_wctr(ppbus, 0x00);
323	    ifp->if_flags &= ~IFF_RUNNING;
324
325	    /* IFF_UP is not set, try to release the bus anyway */
326	    ppb_release_bus(ppbus, dev);
327	    break;
328	}
329	if (((ifp->if_flags & IFF_UP)) && (!(ifp->if_flags & IFF_RUNNING))) {
330
331	    /* XXX
332	     * Should the request be interruptible?
333	     */
334	    if ((error = ppb_request_bus(ppbus, dev, PPB_WAIT|PPB_INTR)))
335		return (error);
336
337	    /* Now IFF_UP means that we own the bus */
338
339	    ppb_set_mode(ppbus, PPB_COMPATIBLE);
340
341	    if (lpinittables()) {
342		ppb_release_bus(ppbus, dev);
343		return ENOBUFS;
344	    }
345
346	    sc->sc_ifbuf = malloc(sc->sc_if.if_mtu + MLPIPHDRLEN,
347				  M_DEVBUF, M_WAITOK);
348	    if (!sc->sc_ifbuf) {
349		ppb_release_bus(ppbus, dev);
350		return ENOBUFS;
351	    }
352
353	    /* attach our interrupt handler, later detached when the bus is released */
354	    if ((error = BUS_SETUP_INTR(ppbus, dev, sc->res_irq,
355					INTR_TYPE_NET, lp_intr, dev, &ih))) {
356		ppb_release_bus(ppbus, dev);
357		return (error);
358	    }
359
360	    ppb_wctr(ppbus, IRQENABLE);
361	    ifp->if_flags |= IFF_RUNNING;
362	}
363	break;
364
365    case SIOCSIFMTU:
366	ptr = sc->sc_ifbuf;
367	sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
368	if (!sc->sc_ifbuf) {
369	    sc->sc_ifbuf = ptr;
370	    return ENOBUFS;
371	}
372	if (ptr)
373	    free(ptr,M_DEVBUF);
374	sc->sc_if.if_mtu = ifr->ifr_mtu;
375	break;
376
377    case SIOCGIFMTU:
378	ifr->ifr_mtu = sc->sc_if.if_mtu;
379	break;
380
381    case SIOCADDMULTI:
382    case SIOCDELMULTI:
383	if (ifr == 0) {
384	    return EAFNOSUPPORT;		/* XXX */
385	}
386	switch (ifr->ifr_addr.sa_family) {
387
388	case AF_INET:
389	    break;
390
391	default:
392	    return EAFNOSUPPORT;
393	}
394	break;
395
396    case SIOCGIFMEDIA:
397	/*
398	 * No ifmedia support at this stage; maybe use it
399	 * in future for eg. protocol selection.
400	 */
401	return EINVAL;
402
403    default:
404	lprintf("LP:ioctl(0x%lx)\n", cmd);
405	return EINVAL;
406    }
407    return 0;
408}
409
410static __inline int
411clpoutbyte (u_char byte, int spin, device_t ppbus)
412{
413	ppb_wdtr(ppbus, ctxmitl[byte]);
414	while (ppb_rstr(ppbus) & CLPIP_SHAKE)
415		if (--spin == 0) {
416			return 1;
417		}
418	ppb_wdtr(ppbus, ctxmith[byte]);
419	while (!(ppb_rstr(ppbus) & CLPIP_SHAKE))
420		if (--spin == 0) {
421			return 1;
422		}
423	return 0;
424}
425
426static __inline int
427clpinbyte (int spin, device_t ppbus)
428{
429	u_char c, cl;
430
431	while((ppb_rstr(ppbus) & CLPIP_SHAKE))
432	    if(!--spin) {
433		return -1;
434	    }
435	cl = ppb_rstr(ppbus);
436	ppb_wdtr(ppbus, 0x10);
437
438	while(!(ppb_rstr(ppbus) & CLPIP_SHAKE))
439	    if(!--spin) {
440		return -1;
441	    }
442	c = ppb_rstr(ppbus);
443	ppb_wdtr(ppbus, 0x00);
444
445	return (ctrecvl[cl] | ctrecvh[c]);
446}
447
448static void
449lptap(struct ifnet *ifp, struct mbuf *m)
450{
451	/*
452	 * Send a packet through bpf. We need to prepend the address family
453	 * as a four byte field. Cons up a dummy header to pacify bpf. This
454	 * is safe because bpf will only read from the mbuf (i.e., it won't
455	 * try to free it or keep a pointer to it).
456	 */
457	u_int32_t af = AF_INET;
458	struct mbuf m0;
459
460	m0.m_next = m;
461	m0.m_len = sizeof(u_int32_t);
462	m0.m_data = (char *)&af;
463	bpf_mtap(ifp, &m0);
464}
465
466static void
467lp_intr (void *arg)
468{
469	device_t dev = (device_t)arg;
470        device_t ppbus = device_get_parent(dev);
471	struct lp_data *sc = DEVTOSOFTC(dev);
472	int len, s, j;
473	u_char *bp;
474	u_char c, cl;
475	struct mbuf *top;
476
477	s = splhigh();
478
479	if (sc->sc_if.if_flags & IFF_LINK0) {
480
481	    /* Ack. the request */
482	    ppb_wdtr(ppbus, 0x01);
483
484	    /* Get the packet length */
485	    j = clpinbyte(LPMAXSPIN2, ppbus);
486	    if (j == -1)
487		goto err;
488	    len = j;
489	    j = clpinbyte(LPMAXSPIN2, ppbus);
490	    if (j == -1)
491		goto err;
492	    len = len + (j << 8);
493	    if (len > sc->sc_if.if_mtu + MLPIPHDRLEN)
494		goto err;
495
496	    bp  = sc->sc_ifbuf;
497
498	    while (len--) {
499	        j = clpinbyte(LPMAXSPIN2, ppbus);
500	        if (j == -1) {
501		    goto err;
502	        }
503	        *bp++ = j;
504	    }
505	    /* Get and ignore checksum */
506	    j = clpinbyte(LPMAXSPIN2, ppbus);
507	    if (j == -1) {
508	        goto err;
509	    }
510
511	    len = bp - sc->sc_ifbuf;
512	    if (len <= CLPIPHDRLEN)
513	        goto err;
514
515	    sc->sc_iferrs = 0;
516
517	    if (IF_QFULL(&ipintrq)) {
518	        lprintf("DROP");
519	        IF_DROP(&ipintrq);
520		goto done;
521	    }
522	    len -= CLPIPHDRLEN;
523	    sc->sc_if.if_ipackets++;
524	    sc->sc_if.if_ibytes += len;
525	    top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, &sc->sc_if, 0);
526	    if (top) {
527		if (sc->sc_if.if_bpf)
528		    lptap(&sc->sc_if, top);
529	        IF_ENQUEUE(&ipintrq, top);
530	        schednetisr(NETISR_IP);
531	    }
532	    goto done;
533	}
534	while ((ppb_rstr(ppbus) & LPIP_SHAKE)) {
535	    len = sc->sc_if.if_mtu + LPIPHDRLEN;
536	    bp  = sc->sc_ifbuf;
537	    while (len--) {
538
539		cl = ppb_rstr(ppbus);
540		ppb_wdtr(ppbus, 8);
541
542		j = LPMAXSPIN2;
543		while((ppb_rstr(ppbus) & LPIP_SHAKE))
544		    if(!--j) goto err;
545
546		c = ppb_rstr(ppbus);
547		ppb_wdtr(ppbus, 0);
548
549		*bp++= trecvh[cl] | trecvl[c];
550
551		j = LPMAXSPIN2;
552		while (!((cl=ppb_rstr(ppbus)) & LPIP_SHAKE)) {
553		    if (cl != c &&
554			(((cl = ppb_rstr(ppbus)) ^ 0xb8) & 0xf8) ==
555			  (c & 0xf8))
556			goto end;
557		    if (!--j) goto err;
558		}
559	    }
560
561	end:
562	    len = bp - sc->sc_ifbuf;
563	    if (len <= LPIPHDRLEN)
564		goto err;
565
566	    sc->sc_iferrs = 0;
567
568	    if (IF_QFULL(&ipintrq)) {
569		lprintf("DROP");
570		IF_DROP(&ipintrq);
571		goto done;
572	    }
573	    len -= LPIPHDRLEN;
574	    sc->sc_if.if_ipackets++;
575	    sc->sc_if.if_ibytes += len;
576	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
577	    if (top) {
578		if (sc->sc_if.if_bpf)
579		    lptap(&sc->sc_if, top);
580		IF_ENQUEUE(&ipintrq, top);
581		schednetisr(NETISR_IP);
582	    }
583	}
584	goto done;
585
586    err:
587	ppb_wdtr(ppbus, 0);
588	lprintf("R");
589	sc->sc_if.if_ierrors++;
590	sc->sc_iferrs++;
591
592	/*
593	 * We are not able to send receive anything for now,
594	 * so stop wasting our time
595	 */
596	if (sc->sc_iferrs > LPMAXERRS) {
597	    printf("lp%d: Too many errors, Going off-line.\n", device_get_unit(dev));
598	    ppb_wctr(ppbus, 0x00);
599	    sc->sc_if.if_flags &= ~IFF_RUNNING;
600	    sc->sc_iferrs=0;
601	}
602
603    done:
604	splx(s);
605	return;
606}
607
608static __inline int
609lpoutbyte (u_char byte, int spin, device_t ppbus)
610{
611    ppb_wdtr(ppbus, txmith[byte]);
612    while (!(ppb_rstr(ppbus) & LPIP_SHAKE))
613	if (--spin == 0)
614		return 1;
615    ppb_wdtr(ppbus, txmitl[byte]);
616    while (ppb_rstr(ppbus) & LPIP_SHAKE)
617	if (--spin == 0)
618		return 1;
619    return 0;
620}
621
622static int
623lpoutput (struct ifnet *ifp, struct mbuf *m,
624	  struct sockaddr *dst, struct rtentry *rt)
625{
626    device_t dev = UNITODEVICE(ifp->if_unit);
627    device_t ppbus = device_get_parent(dev);
628    int s, err;
629    struct mbuf *mm;
630    u_char *cp = "\0\0";
631    u_char chksum = 0;
632    int count = 0;
633    int i, len, spin;
634
635    /* We need a sensible value if we abort */
636    cp++;
637    ifp->if_flags |= IFF_RUNNING;
638
639    err = 1;			/* assume we're aborting because of an error */
640
641    s = splhigh();
642
643    /* Suspend (on laptops) or receive-errors might have taken us offline */
644    ppb_wctr(ppbus, IRQENABLE);
645
646    if (ifp->if_flags & IFF_LINK0) {
647
648	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
649	    lprintf("&");
650	    lp_intr(dev);
651	}
652
653	/* Alert other end to pending packet */
654	spin = LPMAXSPIN1;
655	ppb_wdtr(ppbus, 0x08);
656	while ((ppb_rstr(ppbus) & 0x08) == 0)
657		if (--spin == 0) {
658			goto nend;
659		}
660
661	/* Calculate length of packet, then send that */
662
663	count += 14;		/* Ethernet header len */
664
665	mm = m;
666	for (mm = m; mm; mm = mm->m_next) {
667		count += mm->m_len;
668	}
669	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
670		goto nend;
671	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
672		goto nend;
673
674	/* Send dummy ethernet header */
675	for (i = 0; i < 12; i++) {
676		if (clpoutbyte(i, LPMAXSPIN1, ppbus))
677			goto nend;
678		chksum += i;
679	}
680
681	if (clpoutbyte(0x08, LPMAXSPIN1, ppbus))
682		goto nend;
683	if (clpoutbyte(0x00, LPMAXSPIN1, ppbus))
684		goto nend;
685	chksum += 0x08 + 0x00;		/* Add into checksum */
686
687	mm = m;
688	do {
689		cp = mtod(mm, u_char *);
690		len = mm->m_len;
691		while (len--) {
692			chksum += *cp;
693			if (clpoutbyte(*cp++, LPMAXSPIN2, ppbus))
694				goto nend;
695		}
696	} while ((mm = mm->m_next));
697
698	/* Send checksum */
699	if (clpoutbyte(chksum, LPMAXSPIN2, ppbus))
700		goto nend;
701
702	/* Go quiescent */
703	ppb_wdtr(ppbus, 0);
704
705	err = 0;			/* No errors */
706
707	nend:
708	if (err)  {				/* if we didn't timeout... */
709		ifp->if_oerrors++;
710		lprintf("X");
711	} else {
712		ifp->if_opackets++;
713		ifp->if_obytes += m->m_pkthdr.len;
714		if (ifp->if_bpf)
715		    lptap(ifp, m);
716	}
717
718	m_freem(m);
719
720	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
721		lprintf("^");
722		lp_intr(dev);
723	}
724	(void) splx(s);
725	return 0;
726    }
727
728    if (ppb_rstr(ppbus) & LPIP_SHAKE) {
729        lprintf("&");
730        lp_intr(dev);
731    }
732
733    if (lpoutbyte(0x08, LPMAXSPIN1, ppbus))
734        goto end;
735    if (lpoutbyte(0x00, LPMAXSPIN2, ppbus))
736        goto end;
737
738    mm = m;
739    do {
740        cp = mtod(mm,u_char *);
741	len = mm->m_len;
742        while (len--)
743	    if (lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
744	        goto end;
745    } while ((mm = mm->m_next));
746
747    err = 0;				/* no errors were encountered */
748
749    end:
750    --cp;
751    ppb_wdtr(ppbus, txmitl[*cp] ^ 0x17);
752
753    if (err)  {				/* if we didn't timeout... */
754	ifp->if_oerrors++;
755        lprintf("X");
756    } else {
757	ifp->if_opackets++;
758	ifp->if_obytes += m->m_pkthdr.len;
759	if (ifp->if_bpf)
760	    lptap(ifp, m);
761    }
762
763    m_freem(m);
764
765    if (ppb_rstr(ppbus) & LPIP_SHAKE) {
766	lprintf("^");
767	lp_intr(dev);
768    }
769
770    (void) splx(s);
771    return 0;
772}
773
774static device_method_t lp_methods[] = {
775  	/* device interface */
776	DEVMETHOD(device_identify,	lp_identify),
777	DEVMETHOD(device_probe,		lp_probe),
778	DEVMETHOD(device_attach,	lp_attach),
779
780	{ 0, 0 }
781};
782
783static driver_t lp_driver = {
784  "plip",
785  lp_methods,
786  sizeof(struct lp_data),
787};
788
789DRIVER_MODULE(plip, ppbus, lp_driver, lp_devclass, 0, 0);
790