if_plip.c revision 119418 
1/*-
2 * Copyright (c) 1997 Poul-Henning Kamp
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 *	From Id: lpt.c,v 1.55.2.1 1996/11/12 09:08:38 phk Exp
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: head/sys/dev/ppbus/if_plip.c 119418 2003-08-24 17:55:58Z obrien $");
31
32/*
33 * Parallel port TCP/IP interfaces added.  I looked at the driver from
34 * MACH but this is a complete rewrite, and btw. incompatible, and it
35 * should perform better too.  I have never run the MACH driver though.
36 *
37 * This driver sends two bytes (0x08, 0x00) in front of each packet,
38 * to allow us to distinguish another format later.
39 *
40 * Now added a Linux/Crynwr compatibility mode which is enabled using
41 * IF_LINK0 - Tim Wilkinson.
42 *
43 * TODO:
44 *    Make HDLC/PPP mode, use IF_LLC1 to enable.
45 *
46 * Connect the two computers using a Laplink parallel cable to use this
47 * feature:
48 *
49 *      +----------------------------------------+
50 * 	|A-name	A-End	B-End	Descr.	Port/Bit |
51 *      +----------------------------------------+
52 *	|DATA0	2	15	Data	0/0x01   |
53 *	|-ERROR	15	2	   	1/0x08   |
54 *      +----------------------------------------+
55 *	|DATA1	3	13	Data	0/0x02	 |
56 *	|+SLCT	13	3	   	1/0x10   |
57 *      +----------------------------------------+
58 *	|DATA2	4	12	Data	0/0x04   |
59 *	|+PE	12	4	   	1/0x20   |
60 *      +----------------------------------------+
61 *	|DATA3	5	10	Strobe	0/0x08   |
62 *	|-ACK	10	5	   	1/0x40   |
63 *      +----------------------------------------+
64 *	|DATA4	6	11	Data	0/0x10   |
65 *	|BUSY	11	6	   	1/~0x80  |
66 *      +----------------------------------------+
67 *	|GND	18-25	18-25	GND	-        |
68 *      +----------------------------------------+
69 *
70 * Expect transfer-rates up to 75 kbyte/sec.
71 *
72 * If GCC could correctly grok
73 *	register int port asm("edx")
74 * the code would be cleaner
75 *
76 * Poul-Henning Kamp <phk@freebsd.org>
77 */
78
79/*
80 * Update for ppbus, PLIP support only - Nicolas Souchu
81 */
82
83#include "opt_plip.h"
84
85#include <sys/param.h>
86#include <sys/systm.h>
87#include <sys/module.h>
88#include <sys/bus.h>
89#include <sys/mbuf.h>
90#include <sys/socket.h>
91#include <sys/sockio.h>
92#include <sys/kernel.h>
93#include <sys/malloc.h>
94
95#include <machine/bus.h>
96#include <machine/resource.h>
97#include <sys/rman.h>
98
99#include <net/if.h>
100#include <net/if_types.h>
101#include <net/netisr.h>
102
103#include <netinet/in.h>
104#include <netinet/in_var.h>
105
106#include <net/bpf.h>
107
108#include <dev/ppbus/ppbconf.h>
109#include "ppbus_if.h"
110#include <dev/ppbus/ppbio.h>
111
112#ifndef LPMTU			/* MTU for the lp# interfaces */
113#define	LPMTU	1500
114#endif
115
116#ifndef LPMAXSPIN1		/* DELAY factor for the lp# interfaces */
117#define	LPMAXSPIN1	8000   /* Spinning for remote intr to happen */
118#endif
119
120#ifndef LPMAXSPIN2		/* DELAY factor for the lp# interfaces */
121#define	LPMAXSPIN2	500	/* Spinning for remote handshake to happen */
122#endif
123
124#ifndef LPMAXERRS		/* Max errors before !RUNNING */
125#define	LPMAXERRS	100
126#endif
127
128#define CLPIPHDRLEN	14	/* We send dummy ethernet addresses (two) + packet type in front of packet */
129#define	CLPIP_SHAKE	0x80	/* This bit toggles between nibble reception */
130#define MLPIPHDRLEN	CLPIPHDRLEN
131
132#define LPIPHDRLEN	2	/* We send 0x08, 0x00 in front of packet */
133#define	LPIP_SHAKE	0x40	/* This bit toggles between nibble reception */
134#if !defined(MLPIPHDRLEN) || LPIPHDRLEN > MLPIPHDRLEN
135#define MLPIPHDRLEN	LPIPHDRLEN
136#endif
137
138#define	LPIPTBLSIZE	256	/* Size of octet translation table */
139
140#define lprintf		if (lptflag) printf
141
142#ifdef PLIP_DEBUG
143static int volatile lptflag = 1;
144#else
145static int volatile lptflag = 0;
146#endif
147
148struct lp_data {
149	unsigned short lp_unit;
150
151	struct  ifnet	sc_if;
152	u_char		*sc_ifbuf;
153	int		sc_iferrs;
154
155	struct resource *res_irq;
156};
157
158/* Tables for the lp# interface */
159static u_char *txmith;
160#define txmitl (txmith+(1*LPIPTBLSIZE))
161#define trecvh (txmith+(2*LPIPTBLSIZE))
162#define trecvl (txmith+(3*LPIPTBLSIZE))
163
164static u_char *ctxmith;
165#define ctxmitl (ctxmith+(1*LPIPTBLSIZE))
166#define ctrecvh (ctxmith+(2*LPIPTBLSIZE))
167#define ctrecvl (ctxmith+(3*LPIPTBLSIZE))
168
169/* Functions for the lp# interface */
170static int lpinittables(void);
171static int lpioctl(struct ifnet *, u_long, caddr_t);
172static int lpoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
173	struct rtentry *);
174static void lp_intr(void *);
175
176#define DEVTOSOFTC(dev) \
177	((struct lp_data *)device_get_softc(dev))
178#define UNITOSOFTC(unit) \
179	((struct lp_data *)devclass_get_softc(lp_devclass, (unit)))
180#define UNITODEVICE(unit) \
181	(devclass_get_device(lp_devclass, (unit)))
182
183static devclass_t lp_devclass;
184
185static void
186lp_identify(driver_t *driver, device_t parent)
187{
188
189	BUS_ADD_CHILD(parent, 0, "plip", -1);
190}
191/*
192 * lpprobe()
193 */
194static int
195lp_probe(device_t dev)
196{
197	device_t ppbus = device_get_parent(dev);
198	struct lp_data *lp;
199	int zero = 0;
200	uintptr_t irq;
201
202	lp = DEVTOSOFTC(dev);
203	bzero(lp, sizeof(struct lp_data));
204
205	/* retrieve the ppbus irq */
206	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
207
208	/* if we haven't interrupts, the probe fails */
209	if (irq == -1) {
210		device_printf(dev, "not an interrupt driven port, failed.\n");
211		return (ENXIO);
212	}
213
214	/* reserve the interrupt resource, expecting irq is available to continue */
215	lp->res_irq = bus_alloc_resource(dev, SYS_RES_IRQ, &zero, irq, irq, 1,
216					 RF_SHAREABLE);
217	if (lp->res_irq == 0) {
218		device_printf(dev, "cannot reserve interrupt, failed.\n");
219		return (ENXIO);
220	}
221
222	/*
223	 * lp dependent initialisation.
224	 */
225	lp->lp_unit = device_get_unit(dev);
226
227	device_set_desc(dev, "PLIP network interface");
228
229	return (0);
230}
231
232static int
233lp_attach (device_t dev)
234{
235	struct lp_data *lp = DEVTOSOFTC(dev);
236	struct ifnet *ifp = &lp->sc_if;
237
238	ifp->if_softc = lp;
239	ifp->if_name = "lp";
240	ifp->if_unit = device_get_unit(dev);
241	ifp->if_mtu = LPMTU;
242	ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT | IFF_MULTICAST;
243	ifp->if_ioctl = lpioctl;
244	ifp->if_output = lpoutput;
245	ifp->if_type = IFT_PARA;
246	ifp->if_hdrlen = 0;
247	ifp->if_addrlen = 0;
248	ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;
249	if_attach(ifp);
250
251	bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
252
253	return (0);
254}
255/*
256 * Build the translation tables for the LPIP (BSD unix) protocol.
257 * We don't want to calculate these nasties in our tight loop, so we
258 * precalculate them when we initialize.
259 */
260static int
261lpinittables (void)
262{
263    int i;
264
265    if (!txmith)
266	txmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
267
268    if (!txmith)
269	return 1;
270
271    if (!ctxmith)
272	ctxmith = malloc(4*LPIPTBLSIZE, M_DEVBUF, M_NOWAIT);
273
274    if (!ctxmith)
275	return 1;
276
277    for (i=0; i < LPIPTBLSIZE; i++) {
278	ctxmith[i] = (i & 0xF0) >> 4;
279	ctxmitl[i] = 0x10 | (i & 0x0F);
280	ctrecvh[i] = (i & 0x78) << 1;
281	ctrecvl[i] = (i & 0x78) >> 3;
282    }
283
284    for (i=0; i < LPIPTBLSIZE; i++) {
285	txmith[i] = ((i & 0x80) >> 3) | ((i & 0x70) >> 4) | 0x08;
286	txmitl[i] = ((i & 0x08) << 1) | (i & 0x07);
287	trecvh[i] = ((~i) & 0x80) | ((i & 0x38) << 1);
288	trecvl[i] = (((~i) & 0x80) >> 4) | ((i & 0x38) >> 3);
289    }
290
291    return 0;
292}
293
294/*
295 * Process an ioctl request.
296 */
297
298static int
299lpioctl (struct ifnet *ifp, u_long cmd, caddr_t data)
300{
301    device_t dev = UNITODEVICE(ifp->if_unit);
302    device_t ppbus = device_get_parent(dev);
303    struct lp_data *sc = DEVTOSOFTC(dev);
304    struct ifaddr *ifa = (struct ifaddr *)data;
305    struct ifreq *ifr = (struct ifreq *)data;
306    u_char *ptr;
307    void *ih;
308    int error;
309
310    switch (cmd) {
311
312    case SIOCSIFDSTADDR:
313    case SIOCAIFADDR:
314    case SIOCSIFADDR:
315	if (ifa->ifa_addr->sa_family != AF_INET)
316	    return EAFNOSUPPORT;
317
318	ifp->if_flags |= IFF_UP;
319	/* FALLTHROUGH */
320    case SIOCSIFFLAGS:
321	if ((!(ifp->if_flags & IFF_UP)) && (ifp->if_flags & IFF_RUNNING)) {
322
323	    ppb_wctr(ppbus, 0x00);
324	    ifp->if_flags &= ~IFF_RUNNING;
325
326	    /* IFF_UP is not set, try to release the bus anyway */
327	    ppb_release_bus(ppbus, dev);
328	    break;
329	}
330	if (((ifp->if_flags & IFF_UP)) && (!(ifp->if_flags & IFF_RUNNING))) {
331
332	    /* XXX
333	     * Should the request be interruptible?
334	     */
335	    if ((error = ppb_request_bus(ppbus, dev, PPB_WAIT|PPB_INTR)))
336		return (error);
337
338	    /* Now IFF_UP means that we own the bus */
339
340	    ppb_set_mode(ppbus, PPB_COMPATIBLE);
341
342	    if (lpinittables()) {
343		ppb_release_bus(ppbus, dev);
344		return ENOBUFS;
345	    }
346
347	    sc->sc_ifbuf = malloc(sc->sc_if.if_mtu + MLPIPHDRLEN,
348				  M_DEVBUF, M_WAITOK);
349	    if (!sc->sc_ifbuf) {
350		ppb_release_bus(ppbus, dev);
351		return ENOBUFS;
352	    }
353
354	    /* attach our interrupt handler, later detached when the bus is released */
355	    if ((error = BUS_SETUP_INTR(ppbus, dev, sc->res_irq,
356					INTR_TYPE_NET, lp_intr, dev, &ih))) {
357		ppb_release_bus(ppbus, dev);
358		return (error);
359	    }
360
361	    ppb_wctr(ppbus, IRQENABLE);
362	    ifp->if_flags |= IFF_RUNNING;
363	}
364	break;
365
366    case SIOCSIFMTU:
367	ptr = sc->sc_ifbuf;
368	sc->sc_ifbuf = malloc(ifr->ifr_mtu+MLPIPHDRLEN, M_DEVBUF, M_NOWAIT);
369	if (!sc->sc_ifbuf) {
370	    sc->sc_ifbuf = ptr;
371	    return ENOBUFS;
372	}
373	if (ptr)
374	    free(ptr,M_DEVBUF);
375	sc->sc_if.if_mtu = ifr->ifr_mtu;
376	break;
377
378    case SIOCGIFMTU:
379	ifr->ifr_mtu = sc->sc_if.if_mtu;
380	break;
381
382    case SIOCADDMULTI:
383    case SIOCDELMULTI:
384	if (ifr == 0) {
385	    return EAFNOSUPPORT;		/* XXX */
386	}
387	switch (ifr->ifr_addr.sa_family) {
388
389	case AF_INET:
390	    break;
391
392	default:
393	    return EAFNOSUPPORT;
394	}
395	break;
396
397    case SIOCGIFMEDIA:
398	/*
399	 * No ifmedia support at this stage; maybe use it
400	 * in future for eg. protocol selection.
401	 */
402	return EINVAL;
403
404    default:
405	lprintf("LP:ioctl(0x%lx)\n", cmd);
406	return EINVAL;
407    }
408    return 0;
409}
410
411static __inline int
412clpoutbyte (u_char byte, int spin, device_t ppbus)
413{
414	ppb_wdtr(ppbus, ctxmitl[byte]);
415	while (ppb_rstr(ppbus) & CLPIP_SHAKE)
416		if (--spin == 0) {
417			return 1;
418		}
419	ppb_wdtr(ppbus, ctxmith[byte]);
420	while (!(ppb_rstr(ppbus) & CLPIP_SHAKE))
421		if (--spin == 0) {
422			return 1;
423		}
424	return 0;
425}
426
427static __inline int
428clpinbyte (int spin, device_t ppbus)
429{
430	u_char c, cl;
431
432	while((ppb_rstr(ppbus) & CLPIP_SHAKE))
433	    if(!--spin) {
434		return -1;
435	    }
436	cl = ppb_rstr(ppbus);
437	ppb_wdtr(ppbus, 0x10);
438
439	while(!(ppb_rstr(ppbus) & CLPIP_SHAKE))
440	    if(!--spin) {
441		return -1;
442	    }
443	c = ppb_rstr(ppbus);
444	ppb_wdtr(ppbus, 0x00);
445
446	return (ctrecvl[cl] | ctrecvh[c]);
447}
448
449static void
450lptap(struct ifnet *ifp, struct mbuf *m)
451{
452	/*
453	 * Send a packet through bpf. We need to prepend the address family
454	 * as a four byte field. Cons up a dummy header to pacify bpf. This
455	 * is safe because bpf will only read from the mbuf (i.e., it won't
456	 * try to free it or keep a pointer to it).
457	 */
458	u_int32_t af = AF_INET;
459	struct mbuf m0;
460
461	m0.m_next = m;
462	m0.m_len = sizeof(u_int32_t);
463	m0.m_data = (char *)&af;
464	BPF_MTAP(ifp, &m0);
465}
466
467static void
468lp_intr (void *arg)
469{
470	device_t dev = (device_t)arg;
471        device_t ppbus = device_get_parent(dev);
472	struct lp_data *sc = DEVTOSOFTC(dev);
473	int len, s, j;
474	u_char *bp;
475	u_char c, cl;
476	struct mbuf *top;
477
478	s = splhigh();
479
480	if (sc->sc_if.if_flags & IFF_LINK0) {
481
482	    /* Ack. the request */
483	    ppb_wdtr(ppbus, 0x01);
484
485	    /* Get the packet length */
486	    j = clpinbyte(LPMAXSPIN2, ppbus);
487	    if (j == -1)
488		goto err;
489	    len = j;
490	    j = clpinbyte(LPMAXSPIN2, ppbus);
491	    if (j == -1)
492		goto err;
493	    len = len + (j << 8);
494	    if (len > sc->sc_if.if_mtu + MLPIPHDRLEN)
495		goto err;
496
497	    bp  = sc->sc_ifbuf;
498
499	    while (len--) {
500	        j = clpinbyte(LPMAXSPIN2, ppbus);
501	        if (j == -1) {
502		    goto err;
503	        }
504	        *bp++ = j;
505	    }
506	    /* Get and ignore checksum */
507	    j = clpinbyte(LPMAXSPIN2, ppbus);
508	    if (j == -1) {
509	        goto err;
510	    }
511
512	    len = bp - sc->sc_ifbuf;
513	    if (len <= CLPIPHDRLEN)
514	        goto err;
515
516	    sc->sc_iferrs = 0;
517
518	    len -= CLPIPHDRLEN;
519	    sc->sc_if.if_ipackets++;
520	    sc->sc_if.if_ibytes += len;
521	    top = m_devget(sc->sc_ifbuf + CLPIPHDRLEN, len, 0, &sc->sc_if, 0);
522	    if (top) {
523		if (sc->sc_if.if_bpf)
524		    lptap(&sc->sc_if, top);
525		netisr_queue(NETISR_IP, top);
526	    }
527	    goto done;
528	}
529	while ((ppb_rstr(ppbus) & LPIP_SHAKE)) {
530	    len = sc->sc_if.if_mtu + LPIPHDRLEN;
531	    bp  = sc->sc_ifbuf;
532	    while (len--) {
533
534		cl = ppb_rstr(ppbus);
535		ppb_wdtr(ppbus, 8);
536
537		j = LPMAXSPIN2;
538		while((ppb_rstr(ppbus) & LPIP_SHAKE))
539		    if(!--j) goto err;
540
541		c = ppb_rstr(ppbus);
542		ppb_wdtr(ppbus, 0);
543
544		*bp++= trecvh[cl] | trecvl[c];
545
546		j = LPMAXSPIN2;
547		while (!((cl=ppb_rstr(ppbus)) & LPIP_SHAKE)) {
548		    if (cl != c &&
549			(((cl = ppb_rstr(ppbus)) ^ 0xb8) & 0xf8) ==
550			  (c & 0xf8))
551			goto end;
552		    if (!--j) goto err;
553		}
554	    }
555
556	end:
557	    len = bp - sc->sc_ifbuf;
558	    if (len <= LPIPHDRLEN)
559		goto err;
560
561	    sc->sc_iferrs = 0;
562
563	    len -= LPIPHDRLEN;
564	    sc->sc_if.if_ipackets++;
565	    sc->sc_if.if_ibytes += len;
566	    top = m_devget(sc->sc_ifbuf + LPIPHDRLEN, len, 0, &sc->sc_if, 0);
567	    if (top) {
568		if (sc->sc_if.if_bpf)
569		    lptap(&sc->sc_if, top);
570		netisr_queue(NETISR_IP, top);
571	    }
572	}
573	goto done;
574
575    err:
576	ppb_wdtr(ppbus, 0);
577	lprintf("R");
578	sc->sc_if.if_ierrors++;
579	sc->sc_iferrs++;
580
581	/*
582	 * We are not able to send receive anything for now,
583	 * so stop wasting our time
584	 */
585	if (sc->sc_iferrs > LPMAXERRS) {
586	    printf("lp%d: Too many errors, Going off-line.\n", device_get_unit(dev));
587	    ppb_wctr(ppbus, 0x00);
588	    sc->sc_if.if_flags &= ~IFF_RUNNING;
589	    sc->sc_iferrs=0;
590	}
591
592    done:
593	splx(s);
594	return;
595}
596
597static __inline int
598lpoutbyte (u_char byte, int spin, device_t ppbus)
599{
600    ppb_wdtr(ppbus, txmith[byte]);
601    while (!(ppb_rstr(ppbus) & LPIP_SHAKE))
602	if (--spin == 0)
603		return 1;
604    ppb_wdtr(ppbus, txmitl[byte]);
605    while (ppb_rstr(ppbus) & LPIP_SHAKE)
606	if (--spin == 0)
607		return 1;
608    return 0;
609}
610
611static int
612lpoutput (struct ifnet *ifp, struct mbuf *m,
613	  struct sockaddr *dst, struct rtentry *rt)
614{
615    device_t dev = UNITODEVICE(ifp->if_unit);
616    device_t ppbus = device_get_parent(dev);
617    int s, err;
618    struct mbuf *mm;
619    u_char *cp = "\0\0";
620    u_char chksum = 0;
621    int count = 0;
622    int i, len, spin;
623
624    /* We need a sensible value if we abort */
625    cp++;
626    ifp->if_flags |= IFF_RUNNING;
627
628    err = 1;			/* assume we're aborting because of an error */
629
630    s = splhigh();
631
632    /* Suspend (on laptops) or receive-errors might have taken us offline */
633    ppb_wctr(ppbus, IRQENABLE);
634
635    if (ifp->if_flags & IFF_LINK0) {
636
637	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
638	    lprintf("&");
639	    lp_intr(dev);
640	}
641
642	/* Alert other end to pending packet */
643	spin = LPMAXSPIN1;
644	ppb_wdtr(ppbus, 0x08);
645	while ((ppb_rstr(ppbus) & 0x08) == 0)
646		if (--spin == 0) {
647			goto nend;
648		}
649
650	/* Calculate length of packet, then send that */
651
652	count += 14;		/* Ethernet header len */
653
654	mm = m;
655	for (mm = m; mm; mm = mm->m_next) {
656		count += mm->m_len;
657	}
658	if (clpoutbyte(count & 0xFF, LPMAXSPIN1, ppbus))
659		goto nend;
660	if (clpoutbyte((count >> 8) & 0xFF, LPMAXSPIN1, ppbus))
661		goto nend;
662
663	/* Send dummy ethernet header */
664	for (i = 0; i < 12; i++) {
665		if (clpoutbyte(i, LPMAXSPIN1, ppbus))
666			goto nend;
667		chksum += i;
668	}
669
670	if (clpoutbyte(0x08, LPMAXSPIN1, ppbus))
671		goto nend;
672	if (clpoutbyte(0x00, LPMAXSPIN1, ppbus))
673		goto nend;
674	chksum += 0x08 + 0x00;		/* Add into checksum */
675
676	mm = m;
677	do {
678		cp = mtod(mm, u_char *);
679		len = mm->m_len;
680		while (len--) {
681			chksum += *cp;
682			if (clpoutbyte(*cp++, LPMAXSPIN2, ppbus))
683				goto nend;
684		}
685	} while ((mm = mm->m_next));
686
687	/* Send checksum */
688	if (clpoutbyte(chksum, LPMAXSPIN2, ppbus))
689		goto nend;
690
691	/* Go quiescent */
692	ppb_wdtr(ppbus, 0);
693
694	err = 0;			/* No errors */
695
696	nend:
697	if (err)  {				/* if we didn't timeout... */
698		ifp->if_oerrors++;
699		lprintf("X");
700	} else {
701		ifp->if_opackets++;
702		ifp->if_obytes += m->m_pkthdr.len;
703		if (ifp->if_bpf)
704		    lptap(ifp, m);
705	}
706
707	m_freem(m);
708
709	if (!(ppb_rstr(ppbus) & CLPIP_SHAKE)) {
710		lprintf("^");
711		lp_intr(dev);
712	}
713	(void) splx(s);
714	return 0;
715    }
716
717    if (ppb_rstr(ppbus) & LPIP_SHAKE) {
718        lprintf("&");
719        lp_intr(dev);
720    }
721
722    if (lpoutbyte(0x08, LPMAXSPIN1, ppbus))
723        goto end;
724    if (lpoutbyte(0x00, LPMAXSPIN2, ppbus))
725        goto end;
726
727    mm = m;
728    do {
729        cp = mtod(mm,u_char *);
730	len = mm->m_len;
731        while (len--)
732	    if (lpoutbyte(*cp++, LPMAXSPIN2, ppbus))
733	        goto end;
734    } while ((mm = mm->m_next));
735
736    err = 0;				/* no errors were encountered */
737
738    end:
739    --cp;
740    ppb_wdtr(ppbus, txmitl[*cp] ^ 0x17);
741
742    if (err)  {				/* if we didn't timeout... */
743	ifp->if_oerrors++;
744        lprintf("X");
745    } else {
746	ifp->if_opackets++;
747	ifp->if_obytes += m->m_pkthdr.len;
748	if (ifp->if_bpf)
749	    lptap(ifp, m);
750    }
751
752    m_freem(m);
753
754    if (ppb_rstr(ppbus) & LPIP_SHAKE) {
755	lprintf("^");
756	lp_intr(dev);
757    }
758
759    (void) splx(s);
760    return 0;
761}
762
763static device_method_t lp_methods[] = {
764  	/* device interface */
765	DEVMETHOD(device_identify,	lp_identify),
766	DEVMETHOD(device_probe,		lp_probe),
767	DEVMETHOD(device_attach,	lp_attach),
768
769	{ 0, 0 }
770};
771
772static driver_t lp_driver = {
773  "plip",
774  lp_methods,
775  sizeof(struct lp_data),
776};
777
778DRIVER_MODULE(plip, ppbus, lp_driver, lp_devclass, 0, 0);
779