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1/* $Id: plip.c,v 1.3.6.2 1997/04/16 15:07:56 phil Exp $ */
2/* PLIP: A parallel port "network" driver for Linux. */
3/* This driver is for parallel port with 5-bit cable (LapLink (R) cable). */
4/*
5 * Authors: Donald Becker <becker@scyld.com>
6 * Tommy Thorn <thorn@daimi.aau.dk>
7 * Tanabe Hiroyasu <hiro@sanpo.t.u-tokyo.ac.jp>
8 * Alan Cox <gw4pts@gw4pts.ampr.org>
9 * Peter Bauer <100136.3530@compuserve.com>
10 * Niibe Yutaka <gniibe@mri.co.jp>
11 * Nimrod Zimerman <zimerman@mailandnews.com>
12 *
13 * Enhancements:
14 * Modularization and ifreq/ifmap support by Alan Cox.
15 * Rewritten by Niibe Yutaka.
16 * parport-sharing awareness code by Philip Blundell.
17 * SMP locking by Niibe Yutaka.
18 * Support for parallel ports with no IRQ (poll mode),
19 * Modifications to use the parallel port API
20 * by Nimrod Zimerman.
21 *
22 * Fixes:
23 * Niibe Yutaka
24 * - Module initialization.
25 * - MTU fix.
26 * - Make sure other end is OK, before sending a packet.
27 * - Fix immediate timer problem.
28 *
29 * Al Viro
30 * - Changed {enable,disable}_irq handling to make it work
31 * with new ("stack") semantics.
32 *
33 * This program is free software; you can redistribute it and/or
34 * modify it under the terms of the GNU General Public License
35 * as published by the Free Software Foundation; either version
36 * 2 of the License, or (at your option) any later version.
37 */
38
39/*
40 * Original version and the name 'PLIP' from Donald Becker <becker@scyld.com>
41 * inspired by Russ Nelson's parallel port packet driver.
42 *
43 * NOTE:
44 * Tanabe Hiroyasu had changed the protocol, and it was in Linux v1.0.
45 * Because of the necessity to communicate to DOS machines with the
46 * Crynwr packet driver, Peter Bauer changed the protocol again
47 * back to original protocol.
48 *
49 * This version follows original PLIP protocol.
50 * So, this PLIP can't communicate the PLIP of Linux v1.0.
51 */
52
53/*
54 * To use with DOS box, please do (Turn on ARP switch):
55 * # ifconfig plip[0-2] arp
56 */
57static const char version[] = "NET3 PLIP version 2.4-parport gniibe@mri.co.jp\n";
58
59/*
60 Sources:
61 Ideas and protocols came from Russ Nelson's <nelson@crynwr.com>
62 "parallel.asm" parallel port packet driver.
63
64 The "Crynwr" parallel port standard specifies the following protocol:
65 Trigger by sending nibble '0x8' (this causes interrupt on other end)
66 count-low octet
67 count-high octet
68 ... data octets
69 checksum octet
70 Each octet is sent as <wait for rx. '0x1?'> <send 0x10+(octet&0x0F)>
71 <wait for rx. '0x0?'> <send 0x00+((octet>>4)&0x0F)>
72
73 The packet is encapsulated as if it were ethernet.
74
75 The cable used is a de facto standard parallel null cable -- sold as
76 a "LapLink" cable by various places. You'll need a 12-conductor cable to
77 make one yourself. The wiring is:
78 SLCTIN 17 - 17
79 GROUND 25 - 25
80 D0->ERROR 2 - 15 15 - 2
81 D1->SLCT 3 - 13 13 - 3
82 D2->PAPOUT 4 - 12 12 - 4
83 D3->ACK 5 - 10 10 - 5
84 D4->BUSY 6 - 11 11 - 6
85 Do not connect the other pins. They are
86 D5,D6,D7 are 7,8,9
87 STROBE is 1, FEED is 14, INIT is 16
88 extra grounds are 18,19,20,21,22,23,24
89*/
90
91#include <linux/module.h>
92#include <linux/kernel.h>
93#include <linux/types.h>
94#include <linux/fcntl.h>
95#include <linux/interrupt.h>
96#include <linux/string.h>
97#include <linux/slab.h>
98#include <linux/if_ether.h>
99#include <linux/in.h>
100#include <linux/errno.h>
101#include <linux/delay.h>
102#include <linux/init.h>
103#include <linux/netdevice.h>
104#include <linux/etherdevice.h>
105#include <linux/inetdevice.h>
106#include <linux/skbuff.h>
107#include <linux/if_plip.h>
108#include <linux/workqueue.h>
109#include <linux/spinlock.h>
110#include <linux/completion.h>
111#include <linux/parport.h>
112#include <linux/bitops.h>
113
114#include <net/neighbour.h>
115
116#include <asm/irq.h>
117#include <asm/byteorder.h>
118
119/* Maximum number of devices to support. */
120#define PLIP_MAX 8
121
122/* Use 0 for production, 1 for verification, >2 for debug */
123#ifndef NET_DEBUG
124#define NET_DEBUG 1
125#endif
126static const unsigned int net_debug = NET_DEBUG;
127
128#define ENABLE(irq) if (irq != -1) enable_irq(irq)
129#define DISABLE(irq) if (irq != -1) disable_irq(irq)
130
131/* In micro second */
132#define PLIP_DELAY_UNIT 1
133
134/* Connection time out = PLIP_TRIGGER_WAIT * PLIP_DELAY_UNIT usec */
135#define PLIP_TRIGGER_WAIT 500
136
137/* Nibble time out = PLIP_NIBBLE_WAIT * PLIP_DELAY_UNIT usec */
138#define PLIP_NIBBLE_WAIT 3000
139
140/* Bottom halves */
141static void plip_kick_bh(struct work_struct *work);
142static void plip_bh(struct work_struct *work);
143static void plip_timer_bh(struct work_struct *work);
144
145/* Interrupt handler */
146static void plip_interrupt(void *dev_id);
147
148/* Functions for DEV methods */
149static int plip_tx_packet(struct sk_buff *skb, struct net_device *dev);
150static int plip_hard_header(struct sk_buff *skb, struct net_device *dev,
151 unsigned short type, const void *daddr,
152 const void *saddr, unsigned len);
153static int plip_hard_header_cache(const struct neighbour *neigh,
154 struct hh_cache *hh, __be16 type);
155static int plip_open(struct net_device *dev);
156static int plip_close(struct net_device *dev);
157static int plip_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
158static int plip_preempt(void *handle);
159static void plip_wakeup(void *handle);
160
161enum plip_connection_state {
162 PLIP_CN_NONE=0,
163 PLIP_CN_RECEIVE,
164 PLIP_CN_SEND,
165 PLIP_CN_CLOSING,
166 PLIP_CN_ERROR
167};
168
169enum plip_packet_state {
170 PLIP_PK_DONE=0,
171 PLIP_PK_TRIGGER,
172 PLIP_PK_LENGTH_LSB,
173 PLIP_PK_LENGTH_MSB,
174 PLIP_PK_DATA,
175 PLIP_PK_CHECKSUM
176};
177
178enum plip_nibble_state {
179 PLIP_NB_BEGIN,
180 PLIP_NB_1,
181 PLIP_NB_2,
182};
183
184struct plip_local {
185 enum plip_packet_state state;
186 enum plip_nibble_state nibble;
187 union {
188 struct {
189#if defined(__LITTLE_ENDIAN)
190 unsigned char lsb;
191 unsigned char msb;
192#elif defined(__BIG_ENDIAN)
193 unsigned char msb;
194 unsigned char lsb;
195#else
196#error "Please fix the endianness defines in <asm/byteorder.h>"
197#endif
198 } b;
199 unsigned short h;
200 } length;
201 unsigned short byte;
202 unsigned char checksum;
203 unsigned char data;
204 struct sk_buff *skb;
205};
206
207struct net_local {
208 struct net_device *dev;
209 struct work_struct immediate;
210 struct delayed_work deferred;
211 struct delayed_work timer;
212 struct plip_local snd_data;
213 struct plip_local rcv_data;
214 struct pardevice *pardev;
215 unsigned long trigger;
216 unsigned long nibble;
217 enum plip_connection_state connection;
218 unsigned short timeout_count;
219 int is_deferred;
220 int port_owner;
221 int should_relinquish;
222 spinlock_t lock;
223 atomic_t kill_timer;
224 struct completion killed_timer_cmp;
225};
226
227static inline void enable_parport_interrupts (struct net_device *dev)
228{
229 if (dev->irq != -1)
230 {
231 struct parport *port =
232 ((struct net_local *)netdev_priv(dev))->pardev->port;
233 port->ops->enable_irq (port);
234 }
235}
236
237static inline void disable_parport_interrupts (struct net_device *dev)
238{
239 if (dev->irq != -1)
240 {
241 struct parport *port =
242 ((struct net_local *)netdev_priv(dev))->pardev->port;
243 port->ops->disable_irq (port);
244 }
245}
246
247static inline void write_data (struct net_device *dev, unsigned char data)
248{
249 struct parport *port =
250 ((struct net_local *)netdev_priv(dev))->pardev->port;
251
252 port->ops->write_data (port, data);
253}
254
255static inline unsigned char read_status (struct net_device *dev)
256{
257 struct parport *port =
258 ((struct net_local *)netdev_priv(dev))->pardev->port;
259
260 return port->ops->read_status (port);
261}
262
263static const struct header_ops plip_header_ops = {
264 .create = plip_hard_header,
265 .cache = plip_hard_header_cache,
266};
267
268static const struct net_device_ops plip_netdev_ops = {
269 .ndo_open = plip_open,
270 .ndo_stop = plip_close,
271 .ndo_start_xmit = plip_tx_packet,
272 .ndo_do_ioctl = plip_ioctl,
273 .ndo_set_mac_address = eth_mac_addr,
274 .ndo_validate_addr = eth_validate_addr,
275};
276
277/* Entry point of PLIP driver.
278 Probe the hardware, and register/initialize the driver.
279
280 PLIP is rather weird, because of the way it interacts with the parport
281 system. It is _not_ initialised from Space.c. Instead, plip_init()
282 is called, and that function makes up a "struct net_device" for each port, and
283 then calls us here.
284
285 */
286static void
287plip_init_netdev(struct net_device *dev)
288{
289 struct net_local *nl = netdev_priv(dev);
290
291 /* Then, override parts of it */
292 dev->tx_queue_len = 10;
293 dev->flags = IFF_POINTOPOINT|IFF_NOARP;
294 memset(dev->dev_addr, 0xfc, ETH_ALEN);
295
296 dev->netdev_ops = &plip_netdev_ops;
297 dev->header_ops = &plip_header_ops;
298
299
300 nl->port_owner = 0;
301
302 /* Initialize constants */
303 nl->trigger = PLIP_TRIGGER_WAIT;
304 nl->nibble = PLIP_NIBBLE_WAIT;
305
306 /* Initialize task queue structures */
307 INIT_WORK(&nl->immediate, plip_bh);
308 INIT_DELAYED_WORK(&nl->deferred, plip_kick_bh);
309
310 if (dev->irq == -1)
311 INIT_DELAYED_WORK(&nl->timer, plip_timer_bh);
312
313 spin_lock_init(&nl->lock);
314}
315
316/* Bottom half handler for the delayed request.
317 This routine is kicked by do_timer().
318 Request `plip_bh' to be invoked. */
319static void
320plip_kick_bh(struct work_struct *work)
321{
322 struct net_local *nl =
323 container_of(work, struct net_local, deferred.work);
324
325 if (nl->is_deferred)
326 schedule_work(&nl->immediate);
327}
328
329/* Forward declarations of internal routines */
330static int plip_none(struct net_device *, struct net_local *,
331 struct plip_local *, struct plip_local *);
332static int plip_receive_packet(struct net_device *, struct net_local *,
333 struct plip_local *, struct plip_local *);
334static int plip_send_packet(struct net_device *, struct net_local *,
335 struct plip_local *, struct plip_local *);
336static int plip_connection_close(struct net_device *, struct net_local *,
337 struct plip_local *, struct plip_local *);
338static int plip_error(struct net_device *, struct net_local *,
339 struct plip_local *, struct plip_local *);
340static int plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
341 struct plip_local *snd,
342 struct plip_local *rcv,
343 int error);
344
345#define OK 0
346#define TIMEOUT 1
347#define ERROR 2
348#define HS_TIMEOUT 3
349
350typedef int (*plip_func)(struct net_device *dev, struct net_local *nl,
351 struct plip_local *snd, struct plip_local *rcv);
352
353static const plip_func connection_state_table[] =
354{
355 plip_none,
356 plip_receive_packet,
357 plip_send_packet,
358 plip_connection_close,
359 plip_error
360};
361
362/* Bottom half handler of PLIP. */
363static void
364plip_bh(struct work_struct *work)
365{
366 struct net_local *nl = container_of(work, struct net_local, immediate);
367 struct plip_local *snd = &nl->snd_data;
368 struct plip_local *rcv = &nl->rcv_data;
369 plip_func f;
370 int r;
371
372 nl->is_deferred = 0;
373 f = connection_state_table[nl->connection];
374 if ((r = (*f)(nl->dev, nl, snd, rcv)) != OK &&
375 (r = plip_bh_timeout_error(nl->dev, nl, snd, rcv, r)) != OK) {
376 nl->is_deferred = 1;
377 schedule_delayed_work(&nl->deferred, 1);
378 }
379}
380
381static void
382plip_timer_bh(struct work_struct *work)
383{
384 struct net_local *nl =
385 container_of(work, struct net_local, timer.work);
386
387 if (!(atomic_read (&nl->kill_timer))) {
388 plip_interrupt (nl->dev);
389
390 schedule_delayed_work(&nl->timer, 1);
391 }
392 else {
393 complete(&nl->killed_timer_cmp);
394 }
395}
396
397static int
398plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
399 struct plip_local *snd, struct plip_local *rcv,
400 int error)
401{
402 unsigned char c0;
403 /*
404 * This is tricky. If we got here from the beginning of send (either
405 * with ERROR or HS_TIMEOUT) we have IRQ enabled. Otherwise it's
406 * already disabled. With the old variant of {enable,disable}_irq()
407 * extra disable_irq() was a no-op. Now it became mortal - it's
408 * unbalanced and thus we'll never re-enable IRQ (until rmmod plip,
409 * that is). So we have to treat HS_TIMEOUT and ERROR from send
410 * in a special way.
411 */
412
413 spin_lock_irq(&nl->lock);
414 if (nl->connection == PLIP_CN_SEND) {
415
416 if (error != ERROR) { /* Timeout */
417 nl->timeout_count++;
418 if ((error == HS_TIMEOUT && nl->timeout_count <= 10) ||
419 nl->timeout_count <= 3) {
420 spin_unlock_irq(&nl->lock);
421 /* Try again later */
422 return TIMEOUT;
423 }
424 c0 = read_status(dev);
425 printk(KERN_WARNING "%s: transmit timeout(%d,%02x)\n",
426 dev->name, snd->state, c0);
427 } else
428 error = HS_TIMEOUT;
429 dev->stats.tx_errors++;
430 dev->stats.tx_aborted_errors++;
431 } else if (nl->connection == PLIP_CN_RECEIVE) {
432 if (rcv->state == PLIP_PK_TRIGGER) {
433 /* Transmission was interrupted. */
434 spin_unlock_irq(&nl->lock);
435 return OK;
436 }
437 if (error != ERROR) { /* Timeout */
438 if (++nl->timeout_count <= 3) {
439 spin_unlock_irq(&nl->lock);
440 /* Try again later */
441 return TIMEOUT;
442 }
443 c0 = read_status(dev);
444 printk(KERN_WARNING "%s: receive timeout(%d,%02x)\n",
445 dev->name, rcv->state, c0);
446 }
447 dev->stats.rx_dropped++;
448 }
449 rcv->state = PLIP_PK_DONE;
450 if (rcv->skb) {
451 kfree_skb(rcv->skb);
452 rcv->skb = NULL;
453 }
454 snd->state = PLIP_PK_DONE;
455 if (snd->skb) {
456 dev_kfree_skb(snd->skb);
457 snd->skb = NULL;
458 }
459 spin_unlock_irq(&nl->lock);
460 if (error == HS_TIMEOUT) {
461 DISABLE(dev->irq);
462 synchronize_irq(dev->irq);
463 }
464 disable_parport_interrupts (dev);
465 netif_stop_queue (dev);
466 nl->connection = PLIP_CN_ERROR;
467 write_data (dev, 0x00);
468
469 return TIMEOUT;
470}
471
472static int
473plip_none(struct net_device *dev, struct net_local *nl,
474 struct plip_local *snd, struct plip_local *rcv)
475{
476 return OK;
477}
478
479/* PLIP_RECEIVE --- receive a byte(two nibbles)
480 Returns OK on success, TIMEOUT on timeout */
481static inline int
482plip_receive(unsigned short nibble_timeout, struct net_device *dev,
483 enum plip_nibble_state *ns_p, unsigned char *data_p)
484{
485 unsigned char c0, c1;
486 unsigned int cx;
487
488 switch (*ns_p) {
489 case PLIP_NB_BEGIN:
490 cx = nibble_timeout;
491 while (1) {
492 c0 = read_status(dev);
493 udelay(PLIP_DELAY_UNIT);
494 if ((c0 & 0x80) == 0) {
495 c1 = read_status(dev);
496 if (c0 == c1)
497 break;
498 }
499 if (--cx == 0)
500 return TIMEOUT;
501 }
502 *data_p = (c0 >> 3) & 0x0f;
503 write_data (dev, 0x10); /* send ACK */
504 *ns_p = PLIP_NB_1;
505 /* fall through */
506
507 case PLIP_NB_1:
508 cx = nibble_timeout;
509 while (1) {
510 c0 = read_status(dev);
511 udelay(PLIP_DELAY_UNIT);
512 if (c0 & 0x80) {
513 c1 = read_status(dev);
514 if (c0 == c1)
515 break;
516 }
517 if (--cx == 0)
518 return TIMEOUT;
519 }
520 *data_p |= (c0 << 1) & 0xf0;
521 write_data (dev, 0x00); /* send ACK */
522 *ns_p = PLIP_NB_BEGIN;
523 case PLIP_NB_2:
524 break;
525 }
526 return OK;
527}
528
529/*
530 * Determine the packet's protocol ID. The rule here is that we
531 * assume 802.3 if the type field is short enough to be a length.
532 * This is normal practice and works for any 'now in use' protocol.
533 *
534 * PLIP is ethernet ish but the daddr might not be valid if unicast.
535 * PLIP fortunately has no bus architecture (its Point-to-point).
536 *
537 * We can't fix the daddr thing as that quirk (more bug) is embedded
538 * in far too many old systems not all even running Linux.
539 */
540
541static __be16 plip_type_trans(struct sk_buff *skb, struct net_device *dev)
542{
543 struct ethhdr *eth;
544 unsigned char *rawp;
545
546 skb_reset_mac_header(skb);
547 skb_pull(skb,dev->hard_header_len);
548 eth = eth_hdr(skb);
549
550 if(is_multicast_ether_addr(eth->h_dest))
551 {
552 if(ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
553 skb->pkt_type=PACKET_BROADCAST;
554 else
555 skb->pkt_type=PACKET_MULTICAST;
556 }
557
558 /*
559 * This ALLMULTI check should be redundant by 1.4
560 * so don't forget to remove it.
561 */
562
563 if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN)
564 return eth->h_proto;
565
566 rawp = skb->data;
567
568 /*
569 * This is a magic hack to spot IPX packets. Older Novell breaks
570 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
571 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
572 * won't work for fault tolerant netware but does for the rest.
573 */
574 if (*(unsigned short *)rawp == 0xFFFF)
575 return htons(ETH_P_802_3);
576
577 /*
578 * Real 802.2 LLC
579 */
580 return htons(ETH_P_802_2);
581}
582
583/* PLIP_RECEIVE_PACKET --- receive a packet */
584static int
585plip_receive_packet(struct net_device *dev, struct net_local *nl,
586 struct plip_local *snd, struct plip_local *rcv)
587{
588 unsigned short nibble_timeout = nl->nibble;
589 unsigned char *lbuf;
590
591 switch (rcv->state) {
592 case PLIP_PK_TRIGGER:
593 DISABLE(dev->irq);
594 /* Don't need to synchronize irq, as we can safely ignore it */
595 disable_parport_interrupts (dev);
596 write_data (dev, 0x01); /* send ACK */
597 if (net_debug > 2)
598 printk(KERN_DEBUG "%s: receive start\n", dev->name);
599 rcv->state = PLIP_PK_LENGTH_LSB;
600 rcv->nibble = PLIP_NB_BEGIN;
601 /* fall through */
602
603 case PLIP_PK_LENGTH_LSB:
604 if (snd->state != PLIP_PK_DONE) {
605 if (plip_receive(nl->trigger, dev,
606 &rcv->nibble, &rcv->length.b.lsb)) {
607 /* collision, here dev->tbusy == 1 */
608 rcv->state = PLIP_PK_DONE;
609 nl->is_deferred = 1;
610 nl->connection = PLIP_CN_SEND;
611 schedule_delayed_work(&nl->deferred, 1);
612 enable_parport_interrupts (dev);
613 ENABLE(dev->irq);
614 return OK;
615 }
616 } else {
617 if (plip_receive(nibble_timeout, dev,
618 &rcv->nibble, &rcv->length.b.lsb))
619 return TIMEOUT;
620 }
621 rcv->state = PLIP_PK_LENGTH_MSB;
622 /* fall through */
623
624 case PLIP_PK_LENGTH_MSB:
625 if (plip_receive(nibble_timeout, dev,
626 &rcv->nibble, &rcv->length.b.msb))
627 return TIMEOUT;
628 if (rcv->length.h > dev->mtu + dev->hard_header_len ||
629 rcv->length.h < 8) {
630 printk(KERN_WARNING "%s: bogus packet size %d.\n", dev->name, rcv->length.h);
631 return ERROR;
632 }
633 /* Malloc up new buffer. */
634 rcv->skb = dev_alloc_skb(rcv->length.h + 2);
635 if (rcv->skb == NULL) {
636 printk(KERN_ERR "%s: Memory squeeze.\n", dev->name);
637 return ERROR;
638 }
639 skb_reserve(rcv->skb, 2); /* Align IP on 16 byte boundaries */
640 skb_put(rcv->skb,rcv->length.h);
641 rcv->skb->dev = dev;
642 rcv->state = PLIP_PK_DATA;
643 rcv->byte = 0;
644 rcv->checksum = 0;
645 /* fall through */
646
647 case PLIP_PK_DATA:
648 lbuf = rcv->skb->data;
649 do {
650 if (plip_receive(nibble_timeout, dev,
651 &rcv->nibble, &lbuf[rcv->byte]))
652 return TIMEOUT;
653 } while (++rcv->byte < rcv->length.h);
654 do {
655 rcv->checksum += lbuf[--rcv->byte];
656 } while (rcv->byte);
657 rcv->state = PLIP_PK_CHECKSUM;
658 /* fall through */
659
660 case PLIP_PK_CHECKSUM:
661 if (plip_receive(nibble_timeout, dev,
662 &rcv->nibble, &rcv->data))
663 return TIMEOUT;
664 if (rcv->data != rcv->checksum) {
665 dev->stats.rx_crc_errors++;
666 if (net_debug)
667 printk(KERN_DEBUG "%s: checksum error\n", dev->name);
668 return ERROR;
669 }
670 rcv->state = PLIP_PK_DONE;
671 /* fall through */
672
673 case PLIP_PK_DONE:
674 /* Inform the upper layer for the arrival of a packet. */
675 rcv->skb->protocol=plip_type_trans(rcv->skb, dev);
676 netif_rx_ni(rcv->skb);
677 dev->stats.rx_bytes += rcv->length.h;
678 dev->stats.rx_packets++;
679 rcv->skb = NULL;
680 if (net_debug > 2)
681 printk(KERN_DEBUG "%s: receive end\n", dev->name);
682
683 /* Close the connection. */
684 write_data (dev, 0x00);
685 spin_lock_irq(&nl->lock);
686 if (snd->state != PLIP_PK_DONE) {
687 nl->connection = PLIP_CN_SEND;
688 spin_unlock_irq(&nl->lock);
689 schedule_work(&nl->immediate);
690 enable_parport_interrupts (dev);
691 ENABLE(dev->irq);
692 return OK;
693 } else {
694 nl->connection = PLIP_CN_NONE;
695 spin_unlock_irq(&nl->lock);
696 enable_parport_interrupts (dev);
697 ENABLE(dev->irq);
698 return OK;
699 }
700 }
701 return OK;
702}
703
704/* PLIP_SEND --- send a byte (two nibbles)
705 Returns OK on success, TIMEOUT when timeout */
706static inline int
707plip_send(unsigned short nibble_timeout, struct net_device *dev,
708 enum plip_nibble_state *ns_p, unsigned char data)
709{
710 unsigned char c0;
711 unsigned int cx;
712
713 switch (*ns_p) {
714 case PLIP_NB_BEGIN:
715 write_data (dev, data & 0x0f);
716 *ns_p = PLIP_NB_1;
717 /* fall through */
718
719 case PLIP_NB_1:
720 write_data (dev, 0x10 | (data & 0x0f));
721 cx = nibble_timeout;
722 while (1) {
723 c0 = read_status(dev);
724 if ((c0 & 0x80) == 0)
725 break;
726 if (--cx == 0)
727 return TIMEOUT;
728 udelay(PLIP_DELAY_UNIT);
729 }
730 write_data (dev, 0x10 | (data >> 4));
731 *ns_p = PLIP_NB_2;
732 /* fall through */
733
734 case PLIP_NB_2:
735 write_data (dev, (data >> 4));
736 cx = nibble_timeout;
737 while (1) {
738 c0 = read_status(dev);
739 if (c0 & 0x80)
740 break;
741 if (--cx == 0)
742 return TIMEOUT;
743 udelay(PLIP_DELAY_UNIT);
744 }
745 *ns_p = PLIP_NB_BEGIN;
746 return OK;
747 }
748 return OK;
749}
750
751/* PLIP_SEND_PACKET --- send a packet */
752static int
753plip_send_packet(struct net_device *dev, struct net_local *nl,
754 struct plip_local *snd, struct plip_local *rcv)
755{
756 unsigned short nibble_timeout = nl->nibble;
757 unsigned char *lbuf;
758 unsigned char c0;
759 unsigned int cx;
760
761 if (snd->skb == NULL || (lbuf = snd->skb->data) == NULL) {
762 printk(KERN_DEBUG "%s: send skb lost\n", dev->name);
763 snd->state = PLIP_PK_DONE;
764 snd->skb = NULL;
765 return ERROR;
766 }
767
768 switch (snd->state) {
769 case PLIP_PK_TRIGGER:
770 if ((read_status(dev) & 0xf8) != 0x80)
771 return HS_TIMEOUT;
772
773 /* Trigger remote rx interrupt. */
774 write_data (dev, 0x08);
775 cx = nl->trigger;
776 while (1) {
777 udelay(PLIP_DELAY_UNIT);
778 spin_lock_irq(&nl->lock);
779 if (nl->connection == PLIP_CN_RECEIVE) {
780 spin_unlock_irq(&nl->lock);
781 /* Interrupted. */
782 dev->stats.collisions++;
783 return OK;
784 }
785 c0 = read_status(dev);
786 if (c0 & 0x08) {
787 spin_unlock_irq(&nl->lock);
788 DISABLE(dev->irq);
789 synchronize_irq(dev->irq);
790 if (nl->connection == PLIP_CN_RECEIVE) {
791 /* Interrupted.
792 We don't need to enable irq,
793 as it is soon disabled. */
794 /* Yes, we do. New variant of
795 {enable,disable}_irq *counts*
796 them. -- AV */
797 ENABLE(dev->irq);
798 dev->stats.collisions++;
799 return OK;
800 }
801 disable_parport_interrupts (dev);
802 if (net_debug > 2)
803 printk(KERN_DEBUG "%s: send start\n", dev->name);
804 snd->state = PLIP_PK_LENGTH_LSB;
805 snd->nibble = PLIP_NB_BEGIN;
806 nl->timeout_count = 0;
807 break;
808 }
809 spin_unlock_irq(&nl->lock);
810 if (--cx == 0) {
811 write_data (dev, 0x00);
812 return HS_TIMEOUT;
813 }
814 }
815
816 case PLIP_PK_LENGTH_LSB:
817 if (plip_send(nibble_timeout, dev,
818 &snd->nibble, snd->length.b.lsb))
819 return TIMEOUT;
820 snd->state = PLIP_PK_LENGTH_MSB;
821 /* fall through */
822
823 case PLIP_PK_LENGTH_MSB:
824 if (plip_send(nibble_timeout, dev,
825 &snd->nibble, snd->length.b.msb))
826 return TIMEOUT;
827 snd->state = PLIP_PK_DATA;
828 snd->byte = 0;
829 snd->checksum = 0;
830 /* fall through */
831
832 case PLIP_PK_DATA:
833 do {
834 if (plip_send(nibble_timeout, dev,
835 &snd->nibble, lbuf[snd->byte]))
836 return TIMEOUT;
837 } while (++snd->byte < snd->length.h);
838 do {
839 snd->checksum += lbuf[--snd->byte];
840 } while (snd->byte);
841 snd->state = PLIP_PK_CHECKSUM;
842 /* fall through */
843
844 case PLIP_PK_CHECKSUM:
845 if (plip_send(nibble_timeout, dev,
846 &snd->nibble, snd->checksum))
847 return TIMEOUT;
848
849 dev->stats.tx_bytes += snd->skb->len;
850 dev_kfree_skb(snd->skb);
851 dev->stats.tx_packets++;
852 snd->state = PLIP_PK_DONE;
853 /* fall through */
854
855 case PLIP_PK_DONE:
856 /* Close the connection */
857 write_data (dev, 0x00);
858 snd->skb = NULL;
859 if (net_debug > 2)
860 printk(KERN_DEBUG "%s: send end\n", dev->name);
861 nl->connection = PLIP_CN_CLOSING;
862 nl->is_deferred = 1;
863 schedule_delayed_work(&nl->deferred, 1);
864 enable_parport_interrupts (dev);
865 ENABLE(dev->irq);
866 return OK;
867 }
868 return OK;
869}
870
871static int
872plip_connection_close(struct net_device *dev, struct net_local *nl,
873 struct plip_local *snd, struct plip_local *rcv)
874{
875 spin_lock_irq(&nl->lock);
876 if (nl->connection == PLIP_CN_CLOSING) {
877 nl->connection = PLIP_CN_NONE;
878 netif_wake_queue (dev);
879 }
880 spin_unlock_irq(&nl->lock);
881 if (nl->should_relinquish) {
882 nl->should_relinquish = nl->port_owner = 0;
883 parport_release(nl->pardev);
884 }
885 return OK;
886}
887
888/* PLIP_ERROR --- wait till other end settled */
889static int
890plip_error(struct net_device *dev, struct net_local *nl,
891 struct plip_local *snd, struct plip_local *rcv)
892{
893 unsigned char status;
894
895 status = read_status(dev);
896 if ((status & 0xf8) == 0x80) {
897 if (net_debug > 2)
898 printk(KERN_DEBUG "%s: reset interface.\n", dev->name);
899 nl->connection = PLIP_CN_NONE;
900 nl->should_relinquish = 0;
901 netif_start_queue (dev);
902 enable_parport_interrupts (dev);
903 ENABLE(dev->irq);
904 netif_wake_queue (dev);
905 } else {
906 nl->is_deferred = 1;
907 schedule_delayed_work(&nl->deferred, 1);
908 }
909
910 return OK;
911}
912
913/* Handle the parallel port interrupts. */
914static void
915plip_interrupt(void *dev_id)
916{
917 struct net_device *dev = dev_id;
918 struct net_local *nl;
919 struct plip_local *rcv;
920 unsigned char c0;
921 unsigned long flags;
922
923 nl = netdev_priv(dev);
924 rcv = &nl->rcv_data;
925
926 spin_lock_irqsave (&nl->lock, flags);
927
928 c0 = read_status(dev);
929 if ((c0 & 0xf8) != 0xc0) {
930 if ((dev->irq != -1) && (net_debug > 1))
931 printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
932 spin_unlock_irqrestore (&nl->lock, flags);
933 return;
934 }
935
936 if (net_debug > 3)
937 printk(KERN_DEBUG "%s: interrupt.\n", dev->name);
938
939 switch (nl->connection) {
940 case PLIP_CN_CLOSING:
941 netif_wake_queue (dev);
942 /* fall through */
943 case PLIP_CN_NONE:
944 case PLIP_CN_SEND:
945 rcv->state = PLIP_PK_TRIGGER;
946 nl->connection = PLIP_CN_RECEIVE;
947 nl->timeout_count = 0;
948 schedule_work(&nl->immediate);
949 break;
950
951 case PLIP_CN_RECEIVE:
952 /* May occur because there is race condition
953 around test and set of dev->interrupt.
954 Ignore this interrupt. */
955 break;
956
957 case PLIP_CN_ERROR:
958 printk(KERN_ERR "%s: receive interrupt in error state\n", dev->name);
959 break;
960 }
961
962 spin_unlock_irqrestore(&nl->lock, flags);
963}
964
965static int
966plip_tx_packet(struct sk_buff *skb, struct net_device *dev)
967{
968 struct net_local *nl = netdev_priv(dev);
969 struct plip_local *snd = &nl->snd_data;
970
971 if (netif_queue_stopped(dev))
972 return NETDEV_TX_BUSY;
973
974 /* We may need to grab the bus */
975 if (!nl->port_owner) {
976 if (parport_claim(nl->pardev))
977 return NETDEV_TX_BUSY;
978 nl->port_owner = 1;
979 }
980
981 netif_stop_queue (dev);
982
983 if (skb->len > dev->mtu + dev->hard_header_len) {
984 printk(KERN_WARNING "%s: packet too big, %d.\n", dev->name, (int)skb->len);
985 netif_start_queue (dev);
986 return NETDEV_TX_BUSY;
987 }
988
989 if (net_debug > 2)
990 printk(KERN_DEBUG "%s: send request\n", dev->name);
991
992 spin_lock_irq(&nl->lock);
993 snd->skb = skb;
994 snd->length.h = skb->len;
995 snd->state = PLIP_PK_TRIGGER;
996 if (nl->connection == PLIP_CN_NONE) {
997 nl->connection = PLIP_CN_SEND;
998 nl->timeout_count = 0;
999 }
1000 schedule_work(&nl->immediate);
1001 spin_unlock_irq(&nl->lock);
1002
1003 return NETDEV_TX_OK;
1004}
1005
1006static void
1007plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth)
1008{
1009 const struct in_device *in_dev;
1010
1011 rcu_read_lock();
1012 in_dev = __in_dev_get_rcu(dev);
1013 if (in_dev) {
1014 /* Any address will do - we take the first */
1015 const struct in_ifaddr *ifa = in_dev->ifa_list;
1016 if (ifa) {
1017 memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
1018 memset(eth->h_dest, 0xfc, 2);
1019 memcpy(eth->h_dest+2, &ifa->ifa_address, 4);
1020 }
1021 }
1022 rcu_read_unlock();
1023}
1024
1025static int
1026plip_hard_header(struct sk_buff *skb, struct net_device *dev,
1027 unsigned short type, const void *daddr,
1028 const void *saddr, unsigned len)
1029{
1030 int ret;
1031
1032 ret = eth_header(skb, dev, type, daddr, saddr, len);
1033 if (ret >= 0)
1034 plip_rewrite_address (dev, (struct ethhdr *)skb->data);
1035
1036 return ret;
1037}
1038
1039static int plip_hard_header_cache(const struct neighbour *neigh,
1040 struct hh_cache *hh, __be16 type)
1041{
1042 int ret;
1043
1044 ret = eth_header_cache(neigh, hh, type);
1045 if (ret == 0) {
1046 struct ethhdr *eth;
1047
1048 eth = (struct ethhdr*)(((u8*)hh->hh_data) +
1049 HH_DATA_OFF(sizeof(*eth)));
1050 plip_rewrite_address (neigh->dev, eth);
1051 }
1052
1053 return ret;
1054}
1055
1056/* Open/initialize the board. This is called (in the current kernel)
1057 sometime after booting when the 'ifconfig' program is run.
1058
1059 This routine gets exclusive access to the parallel port by allocating
1060 its IRQ line.
1061 */
1062static int
1063plip_open(struct net_device *dev)
1064{
1065 struct net_local *nl = netdev_priv(dev);
1066 struct in_device *in_dev;
1067
1068 /* Grab the port */
1069 if (!nl->port_owner) {
1070 if (parport_claim(nl->pardev)) return -EAGAIN;
1071 nl->port_owner = 1;
1072 }
1073
1074 nl->should_relinquish = 0;
1075
1076 /* Clear the data port. */
1077 write_data (dev, 0x00);
1078
1079 /* Enable rx interrupt. */
1080 enable_parport_interrupts (dev);
1081 if (dev->irq == -1)
1082 {
1083 atomic_set (&nl->kill_timer, 0);
1084 schedule_delayed_work(&nl->timer, 1);
1085 }
1086
1087 /* Initialize the state machine. */
1088 nl->rcv_data.state = nl->snd_data.state = PLIP_PK_DONE;
1089 nl->rcv_data.skb = nl->snd_data.skb = NULL;
1090 nl->connection = PLIP_CN_NONE;
1091 nl->is_deferred = 0;
1092
1093 /* Fill in the MAC-level header.
1094 We used to abuse dev->broadcast to store the point-to-point
1095 MAC address, but we no longer do it. Instead, we fetch the
1096 interface address whenever it is needed, which is cheap enough
1097 because we use the hh_cache. Actually, abusing dev->broadcast
1098 didn't work, because when using plip_open the point-to-point
1099 address isn't yet known.
1100 PLIP doesn't have a real MAC address, but we need it to be
1101 DOS compatible, and to properly support taps (otherwise,
1102 when the device address isn't identical to the address of a
1103 received frame, the kernel incorrectly drops it). */
1104
1105 in_dev=__in_dev_get_rtnl(dev);
1106 if (in_dev) {
1107 /* Any address will do - we take the first. We already
1108 have the first two bytes filled with 0xfc, from
1109 plip_init_dev(). */
1110 struct in_ifaddr *ifa=in_dev->ifa_list;
1111 if (ifa != NULL) {
1112 memcpy(dev->dev_addr+2, &ifa->ifa_local, 4);
1113 }
1114 }
1115
1116 netif_start_queue (dev);
1117
1118 return 0;
1119}
1120
1121/* The inverse routine to plip_open (). */
1122static int
1123plip_close(struct net_device *dev)
1124{
1125 struct net_local *nl = netdev_priv(dev);
1126 struct plip_local *snd = &nl->snd_data;
1127 struct plip_local *rcv = &nl->rcv_data;
1128
1129 netif_stop_queue (dev);
1130 DISABLE(dev->irq);
1131 synchronize_irq(dev->irq);
1132
1133 if (dev->irq == -1)
1134 {
1135 init_completion(&nl->killed_timer_cmp);
1136 atomic_set (&nl->kill_timer, 1);
1137 wait_for_completion(&nl->killed_timer_cmp);
1138 }
1139
1140#ifdef NOTDEF
1141 outb(0x00, PAR_DATA(dev));
1142#endif
1143 nl->is_deferred = 0;
1144 nl->connection = PLIP_CN_NONE;
1145 if (nl->port_owner) {
1146 parport_release(nl->pardev);
1147 nl->port_owner = 0;
1148 }
1149
1150 snd->state = PLIP_PK_DONE;
1151 if (snd->skb) {
1152 dev_kfree_skb(snd->skb);
1153 snd->skb = NULL;
1154 }
1155 rcv->state = PLIP_PK_DONE;
1156 if (rcv->skb) {
1157 kfree_skb(rcv->skb);
1158 rcv->skb = NULL;
1159 }
1160
1161#ifdef NOTDEF
1162 /* Reset. */
1163 outb(0x00, PAR_CONTROL(dev));
1164#endif
1165 return 0;
1166}
1167
1168static int
1169plip_preempt(void *handle)
1170{
1171 struct net_device *dev = (struct net_device *)handle;
1172 struct net_local *nl = netdev_priv(dev);
1173
1174 /* Stand our ground if a datagram is on the wire */
1175 if (nl->connection != PLIP_CN_NONE) {
1176 nl->should_relinquish = 1;
1177 return 1;
1178 }
1179
1180 nl->port_owner = 0; /* Remember that we released the bus */
1181 return 0;
1182}
1183
1184static void
1185plip_wakeup(void *handle)
1186{
1187 struct net_device *dev = (struct net_device *)handle;
1188 struct net_local *nl = netdev_priv(dev);
1189
1190 if (nl->port_owner) {
1191 /* Why are we being woken up? */
1192 printk(KERN_DEBUG "%s: why am I being woken up?\n", dev->name);
1193 if (!parport_claim(nl->pardev))
1194 /* bus_owner is already set (but why?) */
1195 printk(KERN_DEBUG "%s: I'm broken.\n", dev->name);
1196 else
1197 return;
1198 }
1199
1200 if (!(dev->flags & IFF_UP))
1201 /* Don't need the port when the interface is down */
1202 return;
1203
1204 if (!parport_claim(nl->pardev)) {
1205 nl->port_owner = 1;
1206 /* Clear the data port. */
1207 write_data (dev, 0x00);
1208 }
1209}
1210
1211static int
1212plip_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
1213{
1214 struct net_local *nl = netdev_priv(dev);
1215 struct plipconf *pc = (struct plipconf *) &rq->ifr_ifru;
1216
1217 if (cmd != SIOCDEVPLIP)
1218 return -EOPNOTSUPP;
1219
1220 switch(pc->pcmd) {
1221 case PLIP_GET_TIMEOUT:
1222 pc->trigger = nl->trigger;
1223 pc->nibble = nl->nibble;
1224 break;
1225 case PLIP_SET_TIMEOUT:
1226 if(!capable(CAP_NET_ADMIN))
1227 return -EPERM;
1228 nl->trigger = pc->trigger;
1229 nl->nibble = pc->nibble;
1230 break;
1231 default:
1232 return -EOPNOTSUPP;
1233 }
1234 return 0;
1235}
1236
1237static int parport[PLIP_MAX] = { [0 ... PLIP_MAX-1] = -1 };
1238static int timid;
1239
1240module_param_array(parport, int, NULL, 0);
1241module_param(timid, int, 0);
1242MODULE_PARM_DESC(parport, "List of parport device numbers to use by plip");
1243
1244static struct net_device *dev_plip[PLIP_MAX] = { NULL, };
1245
1246static inline int
1247plip_searchfor(int list[], int a)
1248{
1249 int i;
1250 for (i = 0; i < PLIP_MAX && list[i] != -1; i++) {
1251 if (list[i] == a) return 1;
1252 }
1253 return 0;
1254}
1255
1256/* plip_attach() is called (by the parport code) when a port is
1257 * available to use. */
1258static void plip_attach (struct parport *port)
1259{
1260 static int unit;
1261 struct net_device *dev;
1262 struct net_local *nl;
1263 char name[IFNAMSIZ];
1264 struct pardev_cb plip_cb;
1265
1266 if ((parport[0] == -1 && (!timid || !port->devices)) ||
1267 plip_searchfor(parport, port->number)) {
1268 if (unit == PLIP_MAX) {
1269 printk(KERN_ERR "plip: too many devices\n");
1270 return;
1271 }
1272
1273 sprintf(name, "plip%d", unit);
1274 dev = alloc_etherdev(sizeof(struct net_local));
1275 if (!dev)
1276 return;
1277
1278 strcpy(dev->name, name);
1279
1280 dev->irq = port->irq;
1281 dev->base_addr = port->base;
1282 if (port->irq == -1) {
1283 printk(KERN_INFO "plip: %s has no IRQ. Using IRQ-less mode,"
1284 "which is fairly inefficient!\n", port->name);
1285 }
1286
1287 nl = netdev_priv(dev);
1288 nl->dev = dev;
1289
1290 memset(&plip_cb, 0, sizeof(plip_cb));
1291 plip_cb.private = dev;
1292 plip_cb.preempt = plip_preempt;
1293 plip_cb.wakeup = plip_wakeup;
1294 plip_cb.irq_func = plip_interrupt;
1295
1296 nl->pardev = parport_register_dev_model(port, dev->name,
1297 &plip_cb, unit);
1298
1299 if (!nl->pardev) {
1300 printk(KERN_ERR "%s: parport_register failed\n", name);
1301 goto err_free_dev;
1302 }
1303
1304 plip_init_netdev(dev);
1305
1306 if (register_netdev(dev)) {
1307 printk(KERN_ERR "%s: network register failed\n", name);
1308 goto err_parport_unregister;
1309 }
1310
1311 printk(KERN_INFO "%s", version);
1312 if (dev->irq != -1)
1313 printk(KERN_INFO "%s: Parallel port at %#3lx, "
1314 "using IRQ %d.\n",
1315 dev->name, dev->base_addr, dev->irq);
1316 else
1317 printk(KERN_INFO "%s: Parallel port at %#3lx, "
1318 "not using IRQ.\n",
1319 dev->name, dev->base_addr);
1320 dev_plip[unit++] = dev;
1321 }
1322 return;
1323
1324err_parport_unregister:
1325 parport_unregister_device(nl->pardev);
1326err_free_dev:
1327 free_netdev(dev);
1328}
1329
1330/* plip_detach() is called (by the parport code) when a port is
1331 * no longer available to use. */
1332static void plip_detach (struct parport *port)
1333{
1334 /* Nothing to do */
1335}
1336
1337static int plip_probe(struct pardevice *par_dev)
1338{
1339 struct device_driver *drv = par_dev->dev.driver;
1340 int len = strlen(drv->name);
1341
1342 if (strncmp(par_dev->name, drv->name, len))
1343 return -ENODEV;
1344
1345 return 0;
1346}
1347
1348static struct parport_driver plip_driver = {
1349 .name = "plip",
1350 .probe = plip_probe,
1351 .match_port = plip_attach,
1352 .detach = plip_detach,
1353 .devmodel = true,
1354};
1355
1356static void __exit plip_cleanup_module (void)
1357{
1358 struct net_device *dev;
1359 int i;
1360
1361 for (i=0; i < PLIP_MAX; i++) {
1362 if ((dev = dev_plip[i])) {
1363 struct net_local *nl = netdev_priv(dev);
1364 unregister_netdev(dev);
1365 if (nl->port_owner)
1366 parport_release(nl->pardev);
1367 parport_unregister_device(nl->pardev);
1368 free_netdev(dev);
1369 dev_plip[i] = NULL;
1370 }
1371 }
1372
1373 parport_unregister_driver(&plip_driver);
1374}
1375
1376#ifndef MODULE
1377
1378static int parport_ptr;
1379
1380static int __init plip_setup(char *str)
1381{
1382 int ints[4];
1383
1384 str = get_options(str, ARRAY_SIZE(ints), ints);
1385
1386 /* Ugh. */
1387 if (!strncmp(str, "parport", 7)) {
1388 int n = simple_strtoul(str+7, NULL, 10);
1389 if (parport_ptr < PLIP_MAX)
1390 parport[parport_ptr++] = n;
1391 else
1392 printk(KERN_INFO "plip: too many ports, %s ignored.\n",
1393 str);
1394 } else if (!strcmp(str, "timid")) {
1395 timid = 1;
1396 } else {
1397 if (ints[0] == 0 || ints[1] == 0) {
1398 /* disable driver on "plip=" or "plip=0" */
1399 parport[0] = -2;
1400 } else {
1401 printk(KERN_WARNING "warning: 'plip=0x%x' ignored\n",
1402 ints[1]);
1403 }
1404 }
1405 return 1;
1406}
1407
1408__setup("plip=", plip_setup);
1409
1410#endif /* !MODULE */
1411
1412static int __init plip_init (void)
1413{
1414 if (parport[0] == -2)
1415 return 0;
1416
1417 if (parport[0] != -1 && timid) {
1418 printk(KERN_WARNING "plip: warning, ignoring `timid' since specific ports given.\n");
1419 timid = 0;
1420 }
1421
1422 if (parport_register_driver (&plip_driver)) {
1423 printk (KERN_WARNING "plip: couldn't register driver\n");
1424 return 1;
1425 }
1426
1427 return 0;
1428}
1429
1430module_init(plip_init);
1431module_exit(plip_cleanup_module);
1432MODULE_LICENSE("GPL");
1/* $Id: plip.c,v 1.3.6.2 1997/04/16 15:07:56 phil Exp $ */
2/* PLIP: A parallel port "network" driver for Linux. */
3/* This driver is for parallel port with 5-bit cable (LapLink (R) cable). */
4/*
5 * Authors: Donald Becker <becker@scyld.com>
6 * Tommy Thorn <thorn@daimi.aau.dk>
7 * Tanabe Hiroyasu <hiro@sanpo.t.u-tokyo.ac.jp>
8 * Alan Cox <gw4pts@gw4pts.ampr.org>
9 * Peter Bauer <100136.3530@compuserve.com>
10 * Niibe Yutaka <gniibe@mri.co.jp>
11 * Nimrod Zimerman <zimerman@mailandnews.com>
12 *
13 * Enhancements:
14 * Modularization and ifreq/ifmap support by Alan Cox.
15 * Rewritten by Niibe Yutaka.
16 * parport-sharing awareness code by Philip Blundell.
17 * SMP locking by Niibe Yutaka.
18 * Support for parallel ports with no IRQ (poll mode),
19 * Modifications to use the parallel port API
20 * by Nimrod Zimerman.
21 *
22 * Fixes:
23 * Niibe Yutaka
24 * - Module initialization.
25 * - MTU fix.
26 * - Make sure other end is OK, before sending a packet.
27 * - Fix immediate timer problem.
28 *
29 * Al Viro
30 * - Changed {enable,disable}_irq handling to make it work
31 * with new ("stack") semantics.
32 *
33 * This program is free software; you can redistribute it and/or
34 * modify it under the terms of the GNU General Public License
35 * as published by the Free Software Foundation; either version
36 * 2 of the License, or (at your option) any later version.
37 */
38
39/*
40 * Original version and the name 'PLIP' from Donald Becker <becker@scyld.com>
41 * inspired by Russ Nelson's parallel port packet driver.
42 *
43 * NOTE:
44 * Tanabe Hiroyasu had changed the protocol, and it was in Linux v1.0.
45 * Because of the necessity to communicate to DOS machines with the
46 * Crynwr packet driver, Peter Bauer changed the protocol again
47 * back to original protocol.
48 *
49 * This version follows original PLIP protocol.
50 * So, this PLIP can't communicate the PLIP of Linux v1.0.
51 */
52
53/*
54 * To use with DOS box, please do (Turn on ARP switch):
55 * # ifconfig plip[0-2] arp
56 */
57static const char version[] = "NET3 PLIP version 2.4-parport gniibe@mri.co.jp\n";
58
59/*
60 Sources:
61 Ideas and protocols came from Russ Nelson's <nelson@crynwr.com>
62 "parallel.asm" parallel port packet driver.
63
64 The "Crynwr" parallel port standard specifies the following protocol:
65 Trigger by sending nibble '0x8' (this causes interrupt on other end)
66 count-low octet
67 count-high octet
68 ... data octets
69 checksum octet
70 Each octet is sent as <wait for rx. '0x1?'> <send 0x10+(octet&0x0F)>
71 <wait for rx. '0x0?'> <send 0x00+((octet>>4)&0x0F)>
72
73 The packet is encapsulated as if it were ethernet.
74
75 The cable used is a de facto standard parallel null cable -- sold as
76 a "LapLink" cable by various places. You'll need a 12-conductor cable to
77 make one yourself. The wiring is:
78 SLCTIN 17 - 17
79 GROUND 25 - 25
80 D0->ERROR 2 - 15 15 - 2
81 D1->SLCT 3 - 13 13 - 3
82 D2->PAPOUT 4 - 12 12 - 4
83 D3->ACK 5 - 10 10 - 5
84 D4->BUSY 6 - 11 11 - 6
85 Do not connect the other pins. They are
86 D5,D6,D7 are 7,8,9
87 STROBE is 1, FEED is 14, INIT is 16
88 extra grounds are 18,19,20,21,22,23,24
89*/
90
91#include <linux/module.h>
92#include <linux/kernel.h>
93#include <linux/types.h>
94#include <linux/fcntl.h>
95#include <linux/interrupt.h>
96#include <linux/string.h>
97#include <linux/slab.h>
98#include <linux/if_ether.h>
99#include <linux/in.h>
100#include <linux/errno.h>
101#include <linux/delay.h>
102#include <linux/init.h>
103#include <linux/netdevice.h>
104#include <linux/etherdevice.h>
105#include <linux/inetdevice.h>
106#include <linux/skbuff.h>
107#include <linux/if_plip.h>
108#include <linux/workqueue.h>
109#include <linux/spinlock.h>
110#include <linux/completion.h>
111#include <linux/parport.h>
112#include <linux/bitops.h>
113
114#include <net/neighbour.h>
115
116#include <asm/irq.h>
117#include <asm/byteorder.h>
118
119/* Maximum number of devices to support. */
120#define PLIP_MAX 8
121
122/* Use 0 for production, 1 for verification, >2 for debug */
123#ifndef NET_DEBUG
124#define NET_DEBUG 1
125#endif
126static const unsigned int net_debug = NET_DEBUG;
127
128#define ENABLE(irq) if (irq != -1) enable_irq(irq)
129#define DISABLE(irq) if (irq != -1) disable_irq(irq)
130
131/* In micro second */
132#define PLIP_DELAY_UNIT 1
133
134/* Connection time out = PLIP_TRIGGER_WAIT * PLIP_DELAY_UNIT usec */
135#define PLIP_TRIGGER_WAIT 500
136
137/* Nibble time out = PLIP_NIBBLE_WAIT * PLIP_DELAY_UNIT usec */
138#define PLIP_NIBBLE_WAIT 3000
139
140/* Bottom halves */
141static void plip_kick_bh(struct work_struct *work);
142static void plip_bh(struct work_struct *work);
143static void plip_timer_bh(struct work_struct *work);
144
145/* Interrupt handler */
146static void plip_interrupt(void *dev_id);
147
148/* Functions for DEV methods */
149static int plip_tx_packet(struct sk_buff *skb, struct net_device *dev);
150static int plip_hard_header(struct sk_buff *skb, struct net_device *dev,
151 unsigned short type, const void *daddr,
152 const void *saddr, unsigned len);
153static int plip_hard_header_cache(const struct neighbour *neigh,
154 struct hh_cache *hh, __be16 type);
155static int plip_open(struct net_device *dev);
156static int plip_close(struct net_device *dev);
157static int plip_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
158static int plip_preempt(void *handle);
159static void plip_wakeup(void *handle);
160
161enum plip_connection_state {
162 PLIP_CN_NONE=0,
163 PLIP_CN_RECEIVE,
164 PLIP_CN_SEND,
165 PLIP_CN_CLOSING,
166 PLIP_CN_ERROR
167};
168
169enum plip_packet_state {
170 PLIP_PK_DONE=0,
171 PLIP_PK_TRIGGER,
172 PLIP_PK_LENGTH_LSB,
173 PLIP_PK_LENGTH_MSB,
174 PLIP_PK_DATA,
175 PLIP_PK_CHECKSUM
176};
177
178enum plip_nibble_state {
179 PLIP_NB_BEGIN,
180 PLIP_NB_1,
181 PLIP_NB_2,
182};
183
184struct plip_local {
185 enum plip_packet_state state;
186 enum plip_nibble_state nibble;
187 union {
188 struct {
189#if defined(__LITTLE_ENDIAN)
190 unsigned char lsb;
191 unsigned char msb;
192#elif defined(__BIG_ENDIAN)
193 unsigned char msb;
194 unsigned char lsb;
195#else
196#error "Please fix the endianness defines in <asm/byteorder.h>"
197#endif
198 } b;
199 unsigned short h;
200 } length;
201 unsigned short byte;
202 unsigned char checksum;
203 unsigned char data;
204 struct sk_buff *skb;
205};
206
207struct net_local {
208 struct net_device *dev;
209 struct work_struct immediate;
210 struct delayed_work deferred;
211 struct delayed_work timer;
212 struct plip_local snd_data;
213 struct plip_local rcv_data;
214 struct pardevice *pardev;
215 unsigned long trigger;
216 unsigned long nibble;
217 enum plip_connection_state connection;
218 unsigned short timeout_count;
219 int is_deferred;
220 int port_owner;
221 int should_relinquish;
222 spinlock_t lock;
223 atomic_t kill_timer;
224 struct completion killed_timer_cmp;
225};
226
227static inline void enable_parport_interrupts (struct net_device *dev)
228{
229 if (dev->irq != -1)
230 {
231 struct parport *port =
232 ((struct net_local *)netdev_priv(dev))->pardev->port;
233 port->ops->enable_irq (port);
234 }
235}
236
237static inline void disable_parport_interrupts (struct net_device *dev)
238{
239 if (dev->irq != -1)
240 {
241 struct parport *port =
242 ((struct net_local *)netdev_priv(dev))->pardev->port;
243 port->ops->disable_irq (port);
244 }
245}
246
247static inline void write_data (struct net_device *dev, unsigned char data)
248{
249 struct parport *port =
250 ((struct net_local *)netdev_priv(dev))->pardev->port;
251
252 port->ops->write_data (port, data);
253}
254
255static inline unsigned char read_status (struct net_device *dev)
256{
257 struct parport *port =
258 ((struct net_local *)netdev_priv(dev))->pardev->port;
259
260 return port->ops->read_status (port);
261}
262
263static const struct header_ops plip_header_ops = {
264 .create = plip_hard_header,
265 .cache = plip_hard_header_cache,
266};
267
268static const struct net_device_ops plip_netdev_ops = {
269 .ndo_open = plip_open,
270 .ndo_stop = plip_close,
271 .ndo_start_xmit = plip_tx_packet,
272 .ndo_do_ioctl = plip_ioctl,
273 .ndo_set_mac_address = eth_mac_addr,
274 .ndo_validate_addr = eth_validate_addr,
275};
276
277/* Entry point of PLIP driver.
278 Probe the hardware, and register/initialize the driver.
279
280 PLIP is rather weird, because of the way it interacts with the parport
281 system. It is _not_ initialised from Space.c. Instead, plip_init()
282 is called, and that function makes up a "struct net_device" for each port, and
283 then calls us here.
284
285 */
286static void
287plip_init_netdev(struct net_device *dev)
288{
289 struct net_local *nl = netdev_priv(dev);
290
291 /* Then, override parts of it */
292 dev->tx_queue_len = 10;
293 dev->flags = IFF_POINTOPOINT|IFF_NOARP;
294 memset(dev->dev_addr, 0xfc, ETH_ALEN);
295
296 dev->netdev_ops = &plip_netdev_ops;
297 dev->header_ops = &plip_header_ops;
298
299
300 nl->port_owner = 0;
301
302 /* Initialize constants */
303 nl->trigger = PLIP_TRIGGER_WAIT;
304 nl->nibble = PLIP_NIBBLE_WAIT;
305
306 /* Initialize task queue structures */
307 INIT_WORK(&nl->immediate, plip_bh);
308 INIT_DELAYED_WORK(&nl->deferred, plip_kick_bh);
309
310 if (dev->irq == -1)
311 INIT_DELAYED_WORK(&nl->timer, plip_timer_bh);
312
313 spin_lock_init(&nl->lock);
314}
315
316/* Bottom half handler for the delayed request.
317 This routine is kicked by do_timer().
318 Request `plip_bh' to be invoked. */
319static void
320plip_kick_bh(struct work_struct *work)
321{
322 struct net_local *nl =
323 container_of(work, struct net_local, deferred.work);
324
325 if (nl->is_deferred)
326 schedule_work(&nl->immediate);
327}
328
329/* Forward declarations of internal routines */
330static int plip_none(struct net_device *, struct net_local *,
331 struct plip_local *, struct plip_local *);
332static int plip_receive_packet(struct net_device *, struct net_local *,
333 struct plip_local *, struct plip_local *);
334static int plip_send_packet(struct net_device *, struct net_local *,
335 struct plip_local *, struct plip_local *);
336static int plip_connection_close(struct net_device *, struct net_local *,
337 struct plip_local *, struct plip_local *);
338static int plip_error(struct net_device *, struct net_local *,
339 struct plip_local *, struct plip_local *);
340static int plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
341 struct plip_local *snd,
342 struct plip_local *rcv,
343 int error);
344
345#define OK 0
346#define TIMEOUT 1
347#define ERROR 2
348#define HS_TIMEOUT 3
349
350typedef int (*plip_func)(struct net_device *dev, struct net_local *nl,
351 struct plip_local *snd, struct plip_local *rcv);
352
353static const plip_func connection_state_table[] =
354{
355 plip_none,
356 plip_receive_packet,
357 plip_send_packet,
358 plip_connection_close,
359 plip_error
360};
361
362/* Bottom half handler of PLIP. */
363static void
364plip_bh(struct work_struct *work)
365{
366 struct net_local *nl = container_of(work, struct net_local, immediate);
367 struct plip_local *snd = &nl->snd_data;
368 struct plip_local *rcv = &nl->rcv_data;
369 plip_func f;
370 int r;
371
372 nl->is_deferred = 0;
373 f = connection_state_table[nl->connection];
374 if ((r = (*f)(nl->dev, nl, snd, rcv)) != OK &&
375 (r = plip_bh_timeout_error(nl->dev, nl, snd, rcv, r)) != OK) {
376 nl->is_deferred = 1;
377 schedule_delayed_work(&nl->deferred, 1);
378 }
379}
380
381static void
382plip_timer_bh(struct work_struct *work)
383{
384 struct net_local *nl =
385 container_of(work, struct net_local, timer.work);
386
387 if (!(atomic_read (&nl->kill_timer))) {
388 plip_interrupt (nl->dev);
389
390 schedule_delayed_work(&nl->timer, 1);
391 }
392 else {
393 complete(&nl->killed_timer_cmp);
394 }
395}
396
397static int
398plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
399 struct plip_local *snd, struct plip_local *rcv,
400 int error)
401{
402 unsigned char c0;
403 /*
404 * This is tricky. If we got here from the beginning of send (either
405 * with ERROR or HS_TIMEOUT) we have IRQ enabled. Otherwise it's
406 * already disabled. With the old variant of {enable,disable}_irq()
407 * extra disable_irq() was a no-op. Now it became mortal - it's
408 * unbalanced and thus we'll never re-enable IRQ (until rmmod plip,
409 * that is). So we have to treat HS_TIMEOUT and ERROR from send
410 * in a special way.
411 */
412
413 spin_lock_irq(&nl->lock);
414 if (nl->connection == PLIP_CN_SEND) {
415
416 if (error != ERROR) { /* Timeout */
417 nl->timeout_count++;
418 if ((error == HS_TIMEOUT && nl->timeout_count <= 10) ||
419 nl->timeout_count <= 3) {
420 spin_unlock_irq(&nl->lock);
421 /* Try again later */
422 return TIMEOUT;
423 }
424 c0 = read_status(dev);
425 printk(KERN_WARNING "%s: transmit timeout(%d,%02x)\n",
426 dev->name, snd->state, c0);
427 } else
428 error = HS_TIMEOUT;
429 dev->stats.tx_errors++;
430 dev->stats.tx_aborted_errors++;
431 } else if (nl->connection == PLIP_CN_RECEIVE) {
432 if (rcv->state == PLIP_PK_TRIGGER) {
433 /* Transmission was interrupted. */
434 spin_unlock_irq(&nl->lock);
435 return OK;
436 }
437 if (error != ERROR) { /* Timeout */
438 if (++nl->timeout_count <= 3) {
439 spin_unlock_irq(&nl->lock);
440 /* Try again later */
441 return TIMEOUT;
442 }
443 c0 = read_status(dev);
444 printk(KERN_WARNING "%s: receive timeout(%d,%02x)\n",
445 dev->name, rcv->state, c0);
446 }
447 dev->stats.rx_dropped++;
448 }
449 rcv->state = PLIP_PK_DONE;
450 if (rcv->skb) {
451 kfree_skb(rcv->skb);
452 rcv->skb = NULL;
453 }
454 snd->state = PLIP_PK_DONE;
455 if (snd->skb) {
456 dev_kfree_skb(snd->skb);
457 snd->skb = NULL;
458 }
459 spin_unlock_irq(&nl->lock);
460 if (error == HS_TIMEOUT) {
461 DISABLE(dev->irq);
462 synchronize_irq(dev->irq);
463 }
464 disable_parport_interrupts (dev);
465 netif_stop_queue (dev);
466 nl->connection = PLIP_CN_ERROR;
467 write_data (dev, 0x00);
468
469 return TIMEOUT;
470}
471
472static int
473plip_none(struct net_device *dev, struct net_local *nl,
474 struct plip_local *snd, struct plip_local *rcv)
475{
476 return OK;
477}
478
479/* PLIP_RECEIVE --- receive a byte(two nibbles)
480 Returns OK on success, TIMEOUT on timeout */
481static inline int
482plip_receive(unsigned short nibble_timeout, struct net_device *dev,
483 enum plip_nibble_state *ns_p, unsigned char *data_p)
484{
485 unsigned char c0, c1;
486 unsigned int cx;
487
488 switch (*ns_p) {
489 case PLIP_NB_BEGIN:
490 cx = nibble_timeout;
491 while (1) {
492 c0 = read_status(dev);
493 udelay(PLIP_DELAY_UNIT);
494 if ((c0 & 0x80) == 0) {
495 c1 = read_status(dev);
496 if (c0 == c1)
497 break;
498 }
499 if (--cx == 0)
500 return TIMEOUT;
501 }
502 *data_p = (c0 >> 3) & 0x0f;
503 write_data (dev, 0x10); /* send ACK */
504 *ns_p = PLIP_NB_1;
505
506 case PLIP_NB_1:
507 cx = nibble_timeout;
508 while (1) {
509 c0 = read_status(dev);
510 udelay(PLIP_DELAY_UNIT);
511 if (c0 & 0x80) {
512 c1 = read_status(dev);
513 if (c0 == c1)
514 break;
515 }
516 if (--cx == 0)
517 return TIMEOUT;
518 }
519 *data_p |= (c0 << 1) & 0xf0;
520 write_data (dev, 0x00); /* send ACK */
521 *ns_p = PLIP_NB_BEGIN;
522 case PLIP_NB_2:
523 break;
524 }
525 return OK;
526}
527
528/*
529 * Determine the packet's protocol ID. The rule here is that we
530 * assume 802.3 if the type field is short enough to be a length.
531 * This is normal practice and works for any 'now in use' protocol.
532 *
533 * PLIP is ethernet ish but the daddr might not be valid if unicast.
534 * PLIP fortunately has no bus architecture (its Point-to-point).
535 *
536 * We can't fix the daddr thing as that quirk (more bug) is embedded
537 * in far too many old systems not all even running Linux.
538 */
539
540static __be16 plip_type_trans(struct sk_buff *skb, struct net_device *dev)
541{
542 struct ethhdr *eth;
543 unsigned char *rawp;
544
545 skb_reset_mac_header(skb);
546 skb_pull(skb,dev->hard_header_len);
547 eth = eth_hdr(skb);
548
549 if(is_multicast_ether_addr(eth->h_dest))
550 {
551 if(ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
552 skb->pkt_type=PACKET_BROADCAST;
553 else
554 skb->pkt_type=PACKET_MULTICAST;
555 }
556
557 /*
558 * This ALLMULTI check should be redundant by 1.4
559 * so don't forget to remove it.
560 */
561
562 if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN)
563 return eth->h_proto;
564
565 rawp = skb->data;
566
567 /*
568 * This is a magic hack to spot IPX packets. Older Novell breaks
569 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
570 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
571 * won't work for fault tolerant netware but does for the rest.
572 */
573 if (*(unsigned short *)rawp == 0xFFFF)
574 return htons(ETH_P_802_3);
575
576 /*
577 * Real 802.2 LLC
578 */
579 return htons(ETH_P_802_2);
580}
581
582/* PLIP_RECEIVE_PACKET --- receive a packet */
583static int
584plip_receive_packet(struct net_device *dev, struct net_local *nl,
585 struct plip_local *snd, struct plip_local *rcv)
586{
587 unsigned short nibble_timeout = nl->nibble;
588 unsigned char *lbuf;
589
590 switch (rcv->state) {
591 case PLIP_PK_TRIGGER:
592 DISABLE(dev->irq);
593 /* Don't need to synchronize irq, as we can safely ignore it */
594 disable_parport_interrupts (dev);
595 write_data (dev, 0x01); /* send ACK */
596 if (net_debug > 2)
597 printk(KERN_DEBUG "%s: receive start\n", dev->name);
598 rcv->state = PLIP_PK_LENGTH_LSB;
599 rcv->nibble = PLIP_NB_BEGIN;
600
601 case PLIP_PK_LENGTH_LSB:
602 if (snd->state != PLIP_PK_DONE) {
603 if (plip_receive(nl->trigger, dev,
604 &rcv->nibble, &rcv->length.b.lsb)) {
605 /* collision, here dev->tbusy == 1 */
606 rcv->state = PLIP_PK_DONE;
607 nl->is_deferred = 1;
608 nl->connection = PLIP_CN_SEND;
609 schedule_delayed_work(&nl->deferred, 1);
610 enable_parport_interrupts (dev);
611 ENABLE(dev->irq);
612 return OK;
613 }
614 } else {
615 if (plip_receive(nibble_timeout, dev,
616 &rcv->nibble, &rcv->length.b.lsb))
617 return TIMEOUT;
618 }
619 rcv->state = PLIP_PK_LENGTH_MSB;
620
621 case PLIP_PK_LENGTH_MSB:
622 if (plip_receive(nibble_timeout, dev,
623 &rcv->nibble, &rcv->length.b.msb))
624 return TIMEOUT;
625 if (rcv->length.h > dev->mtu + dev->hard_header_len ||
626 rcv->length.h < 8) {
627 printk(KERN_WARNING "%s: bogus packet size %d.\n", dev->name, rcv->length.h);
628 return ERROR;
629 }
630 /* Malloc up new buffer. */
631 rcv->skb = dev_alloc_skb(rcv->length.h + 2);
632 if (rcv->skb == NULL) {
633 printk(KERN_ERR "%s: Memory squeeze.\n", dev->name);
634 return ERROR;
635 }
636 skb_reserve(rcv->skb, 2); /* Align IP on 16 byte boundaries */
637 skb_put(rcv->skb,rcv->length.h);
638 rcv->skb->dev = dev;
639 rcv->state = PLIP_PK_DATA;
640 rcv->byte = 0;
641 rcv->checksum = 0;
642
643 case PLIP_PK_DATA:
644 lbuf = rcv->skb->data;
645 do {
646 if (plip_receive(nibble_timeout, dev,
647 &rcv->nibble, &lbuf[rcv->byte]))
648 return TIMEOUT;
649 } while (++rcv->byte < rcv->length.h);
650 do {
651 rcv->checksum += lbuf[--rcv->byte];
652 } while (rcv->byte);
653 rcv->state = PLIP_PK_CHECKSUM;
654
655 case PLIP_PK_CHECKSUM:
656 if (plip_receive(nibble_timeout, dev,
657 &rcv->nibble, &rcv->data))
658 return TIMEOUT;
659 if (rcv->data != rcv->checksum) {
660 dev->stats.rx_crc_errors++;
661 if (net_debug)
662 printk(KERN_DEBUG "%s: checksum error\n", dev->name);
663 return ERROR;
664 }
665 rcv->state = PLIP_PK_DONE;
666
667 case PLIP_PK_DONE:
668 /* Inform the upper layer for the arrival of a packet. */
669 rcv->skb->protocol=plip_type_trans(rcv->skb, dev);
670 netif_rx_ni(rcv->skb);
671 dev->stats.rx_bytes += rcv->length.h;
672 dev->stats.rx_packets++;
673 rcv->skb = NULL;
674 if (net_debug > 2)
675 printk(KERN_DEBUG "%s: receive end\n", dev->name);
676
677 /* Close the connection. */
678 write_data (dev, 0x00);
679 spin_lock_irq(&nl->lock);
680 if (snd->state != PLIP_PK_DONE) {
681 nl->connection = PLIP_CN_SEND;
682 spin_unlock_irq(&nl->lock);
683 schedule_work(&nl->immediate);
684 enable_parport_interrupts (dev);
685 ENABLE(dev->irq);
686 return OK;
687 } else {
688 nl->connection = PLIP_CN_NONE;
689 spin_unlock_irq(&nl->lock);
690 enable_parport_interrupts (dev);
691 ENABLE(dev->irq);
692 return OK;
693 }
694 }
695 return OK;
696}
697
698/* PLIP_SEND --- send a byte (two nibbles)
699 Returns OK on success, TIMEOUT when timeout */
700static inline int
701plip_send(unsigned short nibble_timeout, struct net_device *dev,
702 enum plip_nibble_state *ns_p, unsigned char data)
703{
704 unsigned char c0;
705 unsigned int cx;
706
707 switch (*ns_p) {
708 case PLIP_NB_BEGIN:
709 write_data (dev, data & 0x0f);
710 *ns_p = PLIP_NB_1;
711
712 case PLIP_NB_1:
713 write_data (dev, 0x10 | (data & 0x0f));
714 cx = nibble_timeout;
715 while (1) {
716 c0 = read_status(dev);
717 if ((c0 & 0x80) == 0)
718 break;
719 if (--cx == 0)
720 return TIMEOUT;
721 udelay(PLIP_DELAY_UNIT);
722 }
723 write_data (dev, 0x10 | (data >> 4));
724 *ns_p = PLIP_NB_2;
725
726 case PLIP_NB_2:
727 write_data (dev, (data >> 4));
728 cx = nibble_timeout;
729 while (1) {
730 c0 = read_status(dev);
731 if (c0 & 0x80)
732 break;
733 if (--cx == 0)
734 return TIMEOUT;
735 udelay(PLIP_DELAY_UNIT);
736 }
737 *ns_p = PLIP_NB_BEGIN;
738 return OK;
739 }
740 return OK;
741}
742
743/* PLIP_SEND_PACKET --- send a packet */
744static int
745plip_send_packet(struct net_device *dev, struct net_local *nl,
746 struct plip_local *snd, struct plip_local *rcv)
747{
748 unsigned short nibble_timeout = nl->nibble;
749 unsigned char *lbuf;
750 unsigned char c0;
751 unsigned int cx;
752
753 if (snd->skb == NULL || (lbuf = snd->skb->data) == NULL) {
754 printk(KERN_DEBUG "%s: send skb lost\n", dev->name);
755 snd->state = PLIP_PK_DONE;
756 snd->skb = NULL;
757 return ERROR;
758 }
759
760 switch (snd->state) {
761 case PLIP_PK_TRIGGER:
762 if ((read_status(dev) & 0xf8) != 0x80)
763 return HS_TIMEOUT;
764
765 /* Trigger remote rx interrupt. */
766 write_data (dev, 0x08);
767 cx = nl->trigger;
768 while (1) {
769 udelay(PLIP_DELAY_UNIT);
770 spin_lock_irq(&nl->lock);
771 if (nl->connection == PLIP_CN_RECEIVE) {
772 spin_unlock_irq(&nl->lock);
773 /* Interrupted. */
774 dev->stats.collisions++;
775 return OK;
776 }
777 c0 = read_status(dev);
778 if (c0 & 0x08) {
779 spin_unlock_irq(&nl->lock);
780 DISABLE(dev->irq);
781 synchronize_irq(dev->irq);
782 if (nl->connection == PLIP_CN_RECEIVE) {
783 /* Interrupted.
784 We don't need to enable irq,
785 as it is soon disabled. */
786 /* Yes, we do. New variant of
787 {enable,disable}_irq *counts*
788 them. -- AV */
789 ENABLE(dev->irq);
790 dev->stats.collisions++;
791 return OK;
792 }
793 disable_parport_interrupts (dev);
794 if (net_debug > 2)
795 printk(KERN_DEBUG "%s: send start\n", dev->name);
796 snd->state = PLIP_PK_LENGTH_LSB;
797 snd->nibble = PLIP_NB_BEGIN;
798 nl->timeout_count = 0;
799 break;
800 }
801 spin_unlock_irq(&nl->lock);
802 if (--cx == 0) {
803 write_data (dev, 0x00);
804 return HS_TIMEOUT;
805 }
806 }
807
808 case PLIP_PK_LENGTH_LSB:
809 if (plip_send(nibble_timeout, dev,
810 &snd->nibble, snd->length.b.lsb))
811 return TIMEOUT;
812 snd->state = PLIP_PK_LENGTH_MSB;
813
814 case PLIP_PK_LENGTH_MSB:
815 if (plip_send(nibble_timeout, dev,
816 &snd->nibble, snd->length.b.msb))
817 return TIMEOUT;
818 snd->state = PLIP_PK_DATA;
819 snd->byte = 0;
820 snd->checksum = 0;
821
822 case PLIP_PK_DATA:
823 do {
824 if (plip_send(nibble_timeout, dev,
825 &snd->nibble, lbuf[snd->byte]))
826 return TIMEOUT;
827 } while (++snd->byte < snd->length.h);
828 do {
829 snd->checksum += lbuf[--snd->byte];
830 } while (snd->byte);
831 snd->state = PLIP_PK_CHECKSUM;
832
833 case PLIP_PK_CHECKSUM:
834 if (plip_send(nibble_timeout, dev,
835 &snd->nibble, snd->checksum))
836 return TIMEOUT;
837
838 dev->stats.tx_bytes += snd->skb->len;
839 dev_kfree_skb(snd->skb);
840 dev->stats.tx_packets++;
841 snd->state = PLIP_PK_DONE;
842
843 case PLIP_PK_DONE:
844 /* Close the connection */
845 write_data (dev, 0x00);
846 snd->skb = NULL;
847 if (net_debug > 2)
848 printk(KERN_DEBUG "%s: send end\n", dev->name);
849 nl->connection = PLIP_CN_CLOSING;
850 nl->is_deferred = 1;
851 schedule_delayed_work(&nl->deferred, 1);
852 enable_parport_interrupts (dev);
853 ENABLE(dev->irq);
854 return OK;
855 }
856 return OK;
857}
858
859static int
860plip_connection_close(struct net_device *dev, struct net_local *nl,
861 struct plip_local *snd, struct plip_local *rcv)
862{
863 spin_lock_irq(&nl->lock);
864 if (nl->connection == PLIP_CN_CLOSING) {
865 nl->connection = PLIP_CN_NONE;
866 netif_wake_queue (dev);
867 }
868 spin_unlock_irq(&nl->lock);
869 if (nl->should_relinquish) {
870 nl->should_relinquish = nl->port_owner = 0;
871 parport_release(nl->pardev);
872 }
873 return OK;
874}
875
876/* PLIP_ERROR --- wait till other end settled */
877static int
878plip_error(struct net_device *dev, struct net_local *nl,
879 struct plip_local *snd, struct plip_local *rcv)
880{
881 unsigned char status;
882
883 status = read_status(dev);
884 if ((status & 0xf8) == 0x80) {
885 if (net_debug > 2)
886 printk(KERN_DEBUG "%s: reset interface.\n", dev->name);
887 nl->connection = PLIP_CN_NONE;
888 nl->should_relinquish = 0;
889 netif_start_queue (dev);
890 enable_parport_interrupts (dev);
891 ENABLE(dev->irq);
892 netif_wake_queue (dev);
893 } else {
894 nl->is_deferred = 1;
895 schedule_delayed_work(&nl->deferred, 1);
896 }
897
898 return OK;
899}
900
901/* Handle the parallel port interrupts. */
902static void
903plip_interrupt(void *dev_id)
904{
905 struct net_device *dev = dev_id;
906 struct net_local *nl;
907 struct plip_local *rcv;
908 unsigned char c0;
909 unsigned long flags;
910
911 nl = netdev_priv(dev);
912 rcv = &nl->rcv_data;
913
914 spin_lock_irqsave (&nl->lock, flags);
915
916 c0 = read_status(dev);
917 if ((c0 & 0xf8) != 0xc0) {
918 if ((dev->irq != -1) && (net_debug > 1))
919 printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
920 spin_unlock_irqrestore (&nl->lock, flags);
921 return;
922 }
923
924 if (net_debug > 3)
925 printk(KERN_DEBUG "%s: interrupt.\n", dev->name);
926
927 switch (nl->connection) {
928 case PLIP_CN_CLOSING:
929 netif_wake_queue (dev);
930 case PLIP_CN_NONE:
931 case PLIP_CN_SEND:
932 rcv->state = PLIP_PK_TRIGGER;
933 nl->connection = PLIP_CN_RECEIVE;
934 nl->timeout_count = 0;
935 schedule_work(&nl->immediate);
936 break;
937
938 case PLIP_CN_RECEIVE:
939 /* May occur because there is race condition
940 around test and set of dev->interrupt.
941 Ignore this interrupt. */
942 break;
943
944 case PLIP_CN_ERROR:
945 printk(KERN_ERR "%s: receive interrupt in error state\n", dev->name);
946 break;
947 }
948
949 spin_unlock_irqrestore(&nl->lock, flags);
950}
951
952static int
953plip_tx_packet(struct sk_buff *skb, struct net_device *dev)
954{
955 struct net_local *nl = netdev_priv(dev);
956 struct plip_local *snd = &nl->snd_data;
957
958 if (netif_queue_stopped(dev))
959 return NETDEV_TX_BUSY;
960
961 /* We may need to grab the bus */
962 if (!nl->port_owner) {
963 if (parport_claim(nl->pardev))
964 return NETDEV_TX_BUSY;
965 nl->port_owner = 1;
966 }
967
968 netif_stop_queue (dev);
969
970 if (skb->len > dev->mtu + dev->hard_header_len) {
971 printk(KERN_WARNING "%s: packet too big, %d.\n", dev->name, (int)skb->len);
972 netif_start_queue (dev);
973 return NETDEV_TX_BUSY;
974 }
975
976 if (net_debug > 2)
977 printk(KERN_DEBUG "%s: send request\n", dev->name);
978
979 spin_lock_irq(&nl->lock);
980 snd->skb = skb;
981 snd->length.h = skb->len;
982 snd->state = PLIP_PK_TRIGGER;
983 if (nl->connection == PLIP_CN_NONE) {
984 nl->connection = PLIP_CN_SEND;
985 nl->timeout_count = 0;
986 }
987 schedule_work(&nl->immediate);
988 spin_unlock_irq(&nl->lock);
989
990 return NETDEV_TX_OK;
991}
992
993static void
994plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth)
995{
996 const struct in_device *in_dev;
997
998 rcu_read_lock();
999 in_dev = __in_dev_get_rcu(dev);
1000 if (in_dev) {
1001 /* Any address will do - we take the first */
1002 const struct in_ifaddr *ifa = in_dev->ifa_list;
1003 if (ifa) {
1004 memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
1005 memset(eth->h_dest, 0xfc, 2);
1006 memcpy(eth->h_dest+2, &ifa->ifa_address, 4);
1007 }
1008 }
1009 rcu_read_unlock();
1010}
1011
1012static int
1013plip_hard_header(struct sk_buff *skb, struct net_device *dev,
1014 unsigned short type, const void *daddr,
1015 const void *saddr, unsigned len)
1016{
1017 int ret;
1018
1019 ret = eth_header(skb, dev, type, daddr, saddr, len);
1020 if (ret >= 0)
1021 plip_rewrite_address (dev, (struct ethhdr *)skb->data);
1022
1023 return ret;
1024}
1025
1026static int plip_hard_header_cache(const struct neighbour *neigh,
1027 struct hh_cache *hh, __be16 type)
1028{
1029 int ret;
1030
1031 ret = eth_header_cache(neigh, hh, type);
1032 if (ret == 0) {
1033 struct ethhdr *eth;
1034
1035 eth = (struct ethhdr*)(((u8*)hh->hh_data) +
1036 HH_DATA_OFF(sizeof(*eth)));
1037 plip_rewrite_address (neigh->dev, eth);
1038 }
1039
1040 return ret;
1041}
1042
1043/* Open/initialize the board. This is called (in the current kernel)
1044 sometime after booting when the 'ifconfig' program is run.
1045
1046 This routine gets exclusive access to the parallel port by allocating
1047 its IRQ line.
1048 */
1049static int
1050plip_open(struct net_device *dev)
1051{
1052 struct net_local *nl = netdev_priv(dev);
1053 struct in_device *in_dev;
1054
1055 /* Grab the port */
1056 if (!nl->port_owner) {
1057 if (parport_claim(nl->pardev)) return -EAGAIN;
1058 nl->port_owner = 1;
1059 }
1060
1061 nl->should_relinquish = 0;
1062
1063 /* Clear the data port. */
1064 write_data (dev, 0x00);
1065
1066 /* Enable rx interrupt. */
1067 enable_parport_interrupts (dev);
1068 if (dev->irq == -1)
1069 {
1070 atomic_set (&nl->kill_timer, 0);
1071 schedule_delayed_work(&nl->timer, 1);
1072 }
1073
1074 /* Initialize the state machine. */
1075 nl->rcv_data.state = nl->snd_data.state = PLIP_PK_DONE;
1076 nl->rcv_data.skb = nl->snd_data.skb = NULL;
1077 nl->connection = PLIP_CN_NONE;
1078 nl->is_deferred = 0;
1079
1080 /* Fill in the MAC-level header.
1081 We used to abuse dev->broadcast to store the point-to-point
1082 MAC address, but we no longer do it. Instead, we fetch the
1083 interface address whenever it is needed, which is cheap enough
1084 because we use the hh_cache. Actually, abusing dev->broadcast
1085 didn't work, because when using plip_open the point-to-point
1086 address isn't yet known.
1087 PLIP doesn't have a real MAC address, but we need it to be
1088 DOS compatible, and to properly support taps (otherwise,
1089 when the device address isn't identical to the address of a
1090 received frame, the kernel incorrectly drops it). */
1091
1092 in_dev=__in_dev_get_rtnl(dev);
1093 if (in_dev) {
1094 /* Any address will do - we take the first. We already
1095 have the first two bytes filled with 0xfc, from
1096 plip_init_dev(). */
1097 struct in_ifaddr *ifa=in_dev->ifa_list;
1098 if (ifa != NULL) {
1099 memcpy(dev->dev_addr+2, &ifa->ifa_local, 4);
1100 }
1101 }
1102
1103 netif_start_queue (dev);
1104
1105 return 0;
1106}
1107
1108/* The inverse routine to plip_open (). */
1109static int
1110plip_close(struct net_device *dev)
1111{
1112 struct net_local *nl = netdev_priv(dev);
1113 struct plip_local *snd = &nl->snd_data;
1114 struct plip_local *rcv = &nl->rcv_data;
1115
1116 netif_stop_queue (dev);
1117 DISABLE(dev->irq);
1118 synchronize_irq(dev->irq);
1119
1120 if (dev->irq == -1)
1121 {
1122 init_completion(&nl->killed_timer_cmp);
1123 atomic_set (&nl->kill_timer, 1);
1124 wait_for_completion(&nl->killed_timer_cmp);
1125 }
1126
1127#ifdef NOTDEF
1128 outb(0x00, PAR_DATA(dev));
1129#endif
1130 nl->is_deferred = 0;
1131 nl->connection = PLIP_CN_NONE;
1132 if (nl->port_owner) {
1133 parport_release(nl->pardev);
1134 nl->port_owner = 0;
1135 }
1136
1137 snd->state = PLIP_PK_DONE;
1138 if (snd->skb) {
1139 dev_kfree_skb(snd->skb);
1140 snd->skb = NULL;
1141 }
1142 rcv->state = PLIP_PK_DONE;
1143 if (rcv->skb) {
1144 kfree_skb(rcv->skb);
1145 rcv->skb = NULL;
1146 }
1147
1148#ifdef NOTDEF
1149 /* Reset. */
1150 outb(0x00, PAR_CONTROL(dev));
1151#endif
1152 return 0;
1153}
1154
1155static int
1156plip_preempt(void *handle)
1157{
1158 struct net_device *dev = (struct net_device *)handle;
1159 struct net_local *nl = netdev_priv(dev);
1160
1161 /* Stand our ground if a datagram is on the wire */
1162 if (nl->connection != PLIP_CN_NONE) {
1163 nl->should_relinquish = 1;
1164 return 1;
1165 }
1166
1167 nl->port_owner = 0; /* Remember that we released the bus */
1168 return 0;
1169}
1170
1171static void
1172plip_wakeup(void *handle)
1173{
1174 struct net_device *dev = (struct net_device *)handle;
1175 struct net_local *nl = netdev_priv(dev);
1176
1177 if (nl->port_owner) {
1178 /* Why are we being woken up? */
1179 printk(KERN_DEBUG "%s: why am I being woken up?\n", dev->name);
1180 if (!parport_claim(nl->pardev))
1181 /* bus_owner is already set (but why?) */
1182 printk(KERN_DEBUG "%s: I'm broken.\n", dev->name);
1183 else
1184 return;
1185 }
1186
1187 if (!(dev->flags & IFF_UP))
1188 /* Don't need the port when the interface is down */
1189 return;
1190
1191 if (!parport_claim(nl->pardev)) {
1192 nl->port_owner = 1;
1193 /* Clear the data port. */
1194 write_data (dev, 0x00);
1195 }
1196}
1197
1198static int
1199plip_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
1200{
1201 struct net_local *nl = netdev_priv(dev);
1202 struct plipconf *pc = (struct plipconf *) &rq->ifr_ifru;
1203
1204 if (cmd != SIOCDEVPLIP)
1205 return -EOPNOTSUPP;
1206
1207 switch(pc->pcmd) {
1208 case PLIP_GET_TIMEOUT:
1209 pc->trigger = nl->trigger;
1210 pc->nibble = nl->nibble;
1211 break;
1212 case PLIP_SET_TIMEOUT:
1213 if(!capable(CAP_NET_ADMIN))
1214 return -EPERM;
1215 nl->trigger = pc->trigger;
1216 nl->nibble = pc->nibble;
1217 break;
1218 default:
1219 return -EOPNOTSUPP;
1220 }
1221 return 0;
1222}
1223
1224static int parport[PLIP_MAX] = { [0 ... PLIP_MAX-1] = -1 };
1225static int timid;
1226
1227module_param_array(parport, int, NULL, 0);
1228module_param(timid, int, 0);
1229MODULE_PARM_DESC(parport, "List of parport device numbers to use by plip");
1230
1231static struct net_device *dev_plip[PLIP_MAX] = { NULL, };
1232
1233static inline int
1234plip_searchfor(int list[], int a)
1235{
1236 int i;
1237 for (i = 0; i < PLIP_MAX && list[i] != -1; i++) {
1238 if (list[i] == a) return 1;
1239 }
1240 return 0;
1241}
1242
1243/* plip_attach() is called (by the parport code) when a port is
1244 * available to use. */
1245static void plip_attach (struct parport *port)
1246{
1247 static int unit;
1248 struct net_device *dev;
1249 struct net_local *nl;
1250 char name[IFNAMSIZ];
1251 struct pardev_cb plip_cb;
1252
1253 if ((parport[0] == -1 && (!timid || !port->devices)) ||
1254 plip_searchfor(parport, port->number)) {
1255 if (unit == PLIP_MAX) {
1256 printk(KERN_ERR "plip: too many devices\n");
1257 return;
1258 }
1259
1260 sprintf(name, "plip%d", unit);
1261 dev = alloc_etherdev(sizeof(struct net_local));
1262 if (!dev)
1263 return;
1264
1265 strcpy(dev->name, name);
1266
1267 dev->irq = port->irq;
1268 dev->base_addr = port->base;
1269 if (port->irq == -1) {
1270 printk(KERN_INFO "plip: %s has no IRQ. Using IRQ-less mode,"
1271 "which is fairly inefficient!\n", port->name);
1272 }
1273
1274 nl = netdev_priv(dev);
1275 nl->dev = dev;
1276
1277 memset(&plip_cb, 0, sizeof(plip_cb));
1278 plip_cb.private = dev;
1279 plip_cb.preempt = plip_preempt;
1280 plip_cb.wakeup = plip_wakeup;
1281 plip_cb.irq_func = plip_interrupt;
1282
1283 nl->pardev = parport_register_dev_model(port, dev->name,
1284 &plip_cb, unit);
1285
1286 if (!nl->pardev) {
1287 printk(KERN_ERR "%s: parport_register failed\n", name);
1288 goto err_free_dev;
1289 }
1290
1291 plip_init_netdev(dev);
1292
1293 if (register_netdev(dev)) {
1294 printk(KERN_ERR "%s: network register failed\n", name);
1295 goto err_parport_unregister;
1296 }
1297
1298 printk(KERN_INFO "%s", version);
1299 if (dev->irq != -1)
1300 printk(KERN_INFO "%s: Parallel port at %#3lx, "
1301 "using IRQ %d.\n",
1302 dev->name, dev->base_addr, dev->irq);
1303 else
1304 printk(KERN_INFO "%s: Parallel port at %#3lx, "
1305 "not using IRQ.\n",
1306 dev->name, dev->base_addr);
1307 dev_plip[unit++] = dev;
1308 }
1309 return;
1310
1311err_parport_unregister:
1312 parport_unregister_device(nl->pardev);
1313err_free_dev:
1314 free_netdev(dev);
1315}
1316
1317/* plip_detach() is called (by the parport code) when a port is
1318 * no longer available to use. */
1319static void plip_detach (struct parport *port)
1320{
1321 /* Nothing to do */
1322}
1323
1324static int plip_probe(struct pardevice *par_dev)
1325{
1326 struct device_driver *drv = par_dev->dev.driver;
1327 int len = strlen(drv->name);
1328
1329 if (strncmp(par_dev->name, drv->name, len))
1330 return -ENODEV;
1331
1332 return 0;
1333}
1334
1335static struct parport_driver plip_driver = {
1336 .name = "plip",
1337 .probe = plip_probe,
1338 .match_port = plip_attach,
1339 .detach = plip_detach,
1340 .devmodel = true,
1341};
1342
1343static void __exit plip_cleanup_module (void)
1344{
1345 struct net_device *dev;
1346 int i;
1347
1348 for (i=0; i < PLIP_MAX; i++) {
1349 if ((dev = dev_plip[i])) {
1350 struct net_local *nl = netdev_priv(dev);
1351 unregister_netdev(dev);
1352 if (nl->port_owner)
1353 parport_release(nl->pardev);
1354 parport_unregister_device(nl->pardev);
1355 free_netdev(dev);
1356 dev_plip[i] = NULL;
1357 }
1358 }
1359
1360 parport_unregister_driver(&plip_driver);
1361}
1362
1363#ifndef MODULE
1364
1365static int parport_ptr;
1366
1367static int __init plip_setup(char *str)
1368{
1369 int ints[4];
1370
1371 str = get_options(str, ARRAY_SIZE(ints), ints);
1372
1373 /* Ugh. */
1374 if (!strncmp(str, "parport", 7)) {
1375 int n = simple_strtoul(str+7, NULL, 10);
1376 if (parport_ptr < PLIP_MAX)
1377 parport[parport_ptr++] = n;
1378 else
1379 printk(KERN_INFO "plip: too many ports, %s ignored.\n",
1380 str);
1381 } else if (!strcmp(str, "timid")) {
1382 timid = 1;
1383 } else {
1384 if (ints[0] == 0 || ints[1] == 0) {
1385 /* disable driver on "plip=" or "plip=0" */
1386 parport[0] = -2;
1387 } else {
1388 printk(KERN_WARNING "warning: 'plip=0x%x' ignored\n",
1389 ints[1]);
1390 }
1391 }
1392 return 1;
1393}
1394
1395__setup("plip=", plip_setup);
1396
1397#endif /* !MODULE */
1398
1399static int __init plip_init (void)
1400{
1401 if (parport[0] == -2)
1402 return 0;
1403
1404 if (parport[0] != -1 && timid) {
1405 printk(KERN_WARNING "plip: warning, ignoring `timid' since specific ports given.\n");
1406 timid = 0;
1407 }
1408
1409 if (parport_register_driver (&plip_driver)) {
1410 printk (KERN_WARNING "plip: couldn't register driver\n");
1411 return 1;
1412 }
1413
1414 return 0;
1415}
1416
1417module_init(plip_init);
1418module_exit(plip_cleanup_module);
1419MODULE_LICENSE("GPL");