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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* $Id: plip.c,v 1.3.6.2 1997/04/16 15:07:56 phil Exp $ */
3/* PLIP: A parallel port "network" driver for Linux. */
4/* This driver is for parallel port with 5-bit cable (LapLink (R) cable). */
5/*
6 * Authors: Donald Becker <becker@scyld.com>
7 * Tommy Thorn <thorn@daimi.aau.dk>
8 * Tanabe Hiroyasu <hiro@sanpo.t.u-tokyo.ac.jp>
9 * Alan Cox <gw4pts@gw4pts.ampr.org>
10 * Peter Bauer <100136.3530@compuserve.com>
11 * Niibe Yutaka <gniibe@mri.co.jp>
12 * Nimrod Zimerman <zimerman@mailandnews.com>
13 *
14 * Enhancements:
15 * Modularization and ifreq/ifmap support by Alan Cox.
16 * Rewritten by Niibe Yutaka.
17 * parport-sharing awareness code by Philip Blundell.
18 * SMP locking by Niibe Yutaka.
19 * Support for parallel ports with no IRQ (poll mode),
20 * Modifications to use the parallel port API
21 * by Nimrod Zimerman.
22 *
23 * Fixes:
24 * Niibe Yutaka
25 * - Module initialization.
26 * - MTU fix.
27 * - Make sure other end is OK, before sending a packet.
28 * - Fix immediate timer problem.
29 *
30 * Al Viro
31 * - Changed {enable,disable}_irq handling to make it work
32 * with new ("stack") semantics.
33 */
34
35/*
36 * Original version and the name 'PLIP' from Donald Becker <becker@scyld.com>
37 * inspired by Russ Nelson's parallel port packet driver.
38 *
39 * NOTE:
40 * Tanabe Hiroyasu had changed the protocol, and it was in Linux v1.0.
41 * Because of the necessity to communicate to DOS machines with the
42 * Crynwr packet driver, Peter Bauer changed the protocol again
43 * back to original protocol.
44 *
45 * This version follows original PLIP protocol.
46 * So, this PLIP can't communicate the PLIP of Linux v1.0.
47 */
48
49/*
50 * To use with DOS box, please do (Turn on ARP switch):
51 * # ifconfig plip[0-2] arp
52 */
53static const char version[] = "NET3 PLIP version 2.4-parport gniibe@mri.co.jp\n";
54
55/*
56 Sources:
57 Ideas and protocols came from Russ Nelson's <nelson@crynwr.com>
58 "parallel.asm" parallel port packet driver.
59
60 The "Crynwr" parallel port standard specifies the following protocol:
61 Trigger by sending nibble '0x8' (this causes interrupt on other end)
62 count-low octet
63 count-high octet
64 ... data octets
65 checksum octet
66 Each octet is sent as <wait for rx. '0x1?'> <send 0x10+(octet&0x0F)>
67 <wait for rx. '0x0?'> <send 0x00+((octet>>4)&0x0F)>
68
69 The packet is encapsulated as if it were ethernet.
70
71 The cable used is a de facto standard parallel null cable -- sold as
72 a "LapLink" cable by various places. You'll need a 12-conductor cable to
73 make one yourself. The wiring is:
74 SLCTIN 17 - 17
75 GROUND 25 - 25
76 D0->ERROR 2 - 15 15 - 2
77 D1->SLCT 3 - 13 13 - 3
78 D2->PAPOUT 4 - 12 12 - 4
79 D3->ACK 5 - 10 10 - 5
80 D4->BUSY 6 - 11 11 - 6
81 Do not connect the other pins. They are
82 D5,D6,D7 are 7,8,9
83 STROBE is 1, FEED is 14, INIT is 16
84 extra grounds are 18,19,20,21,22,23,24
85*/
86
87#include <linux/compat.h>
88#include <linux/module.h>
89#include <linux/kernel.h>
90#include <linux/types.h>
91#include <linux/fcntl.h>
92#include <linux/interrupt.h>
93#include <linux/string.h>
94#include <linux/slab.h>
95#include <linux/if_ether.h>
96#include <linux/in.h>
97#include <linux/errno.h>
98#include <linux/delay.h>
99#include <linux/init.h>
100#include <linux/netdevice.h>
101#include <linux/etherdevice.h>
102#include <linux/inetdevice.h>
103#include <linux/skbuff.h>
104#include <linux/if_plip.h>
105#include <linux/workqueue.h>
106#include <linux/spinlock.h>
107#include <linux/completion.h>
108#include <linux/parport.h>
109#include <linux/bitops.h>
110
111#include <net/neighbour.h>
112
113#include <asm/irq.h>
114#include <asm/byteorder.h>
115
116/* Maximum number of devices to support. */
117#define PLIP_MAX 8
118
119/* Use 0 for production, 1 for verification, >2 for debug */
120#ifndef NET_DEBUG
121#define NET_DEBUG 1
122#endif
123static const unsigned int net_debug = NET_DEBUG;
124
125#define ENABLE(irq) if (irq != -1) enable_irq(irq)
126#define DISABLE(irq) if (irq != -1) disable_irq(irq)
127
128/* In micro second */
129#define PLIP_DELAY_UNIT 1
130
131/* Connection time out = PLIP_TRIGGER_WAIT * PLIP_DELAY_UNIT usec */
132#define PLIP_TRIGGER_WAIT 500
133
134/* Nibble time out = PLIP_NIBBLE_WAIT * PLIP_DELAY_UNIT usec */
135#define PLIP_NIBBLE_WAIT 3000
136
137/* Bottom halves */
138static void plip_kick_bh(struct work_struct *work);
139static void plip_bh(struct work_struct *work);
140static void plip_timer_bh(struct work_struct *work);
141
142/* Interrupt handler */
143static void plip_interrupt(void *dev_id);
144
145/* Functions for DEV methods */
146static netdev_tx_t plip_tx_packet(struct sk_buff *skb, struct net_device *dev);
147static int plip_hard_header(struct sk_buff *skb, struct net_device *dev,
148 unsigned short type, const void *daddr,
149 const void *saddr, unsigned len);
150static int plip_hard_header_cache(const struct neighbour *neigh,
151 struct hh_cache *hh, __be16 type);
152static int plip_open(struct net_device *dev);
153static int plip_close(struct net_device *dev);
154static int plip_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
155 void __user *data, int cmd);
156static int plip_preempt(void *handle);
157static void plip_wakeup(void *handle);
158
159enum plip_connection_state {
160 PLIP_CN_NONE=0,
161 PLIP_CN_RECEIVE,
162 PLIP_CN_SEND,
163 PLIP_CN_CLOSING,
164 PLIP_CN_ERROR
165};
166
167enum plip_packet_state {
168 PLIP_PK_DONE=0,
169 PLIP_PK_TRIGGER,
170 PLIP_PK_LENGTH_LSB,
171 PLIP_PK_LENGTH_MSB,
172 PLIP_PK_DATA,
173 PLIP_PK_CHECKSUM
174};
175
176enum plip_nibble_state {
177 PLIP_NB_BEGIN,
178 PLIP_NB_1,
179 PLIP_NB_2,
180};
181
182struct plip_local {
183 enum plip_packet_state state;
184 enum plip_nibble_state nibble;
185 union {
186 struct {
187#if defined(__LITTLE_ENDIAN)
188 unsigned char lsb;
189 unsigned char msb;
190#elif defined(__BIG_ENDIAN)
191 unsigned char msb;
192 unsigned char lsb;
193#else
194#error "Please fix the endianness defines in <asm/byteorder.h>"
195#endif
196 } b;
197 unsigned short h;
198 } length;
199 unsigned short byte;
200 unsigned char checksum;
201 unsigned char data;
202 struct sk_buff *skb;
203};
204
205struct net_local {
206 struct net_device *dev;
207 struct work_struct immediate;
208 struct delayed_work deferred;
209 struct delayed_work timer;
210 struct plip_local snd_data;
211 struct plip_local rcv_data;
212 struct pardevice *pardev;
213 unsigned long trigger;
214 unsigned long nibble;
215 enum plip_connection_state connection;
216 unsigned short timeout_count;
217 int is_deferred;
218 int port_owner;
219 int should_relinquish;
220 spinlock_t lock;
221 atomic_t kill_timer;
222 struct completion killed_timer_cmp;
223};
224
225static inline void enable_parport_interrupts (struct net_device *dev)
226{
227 if (dev->irq != -1)
228 {
229 struct parport *port =
230 ((struct net_local *)netdev_priv(dev))->pardev->port;
231 port->ops->enable_irq (port);
232 }
233}
234
235static inline void disable_parport_interrupts (struct net_device *dev)
236{
237 if (dev->irq != -1)
238 {
239 struct parport *port =
240 ((struct net_local *)netdev_priv(dev))->pardev->port;
241 port->ops->disable_irq (port);
242 }
243}
244
245static inline void write_data (struct net_device *dev, unsigned char data)
246{
247 struct parport *port =
248 ((struct net_local *)netdev_priv(dev))->pardev->port;
249
250 port->ops->write_data (port, data);
251}
252
253static inline unsigned char read_status (struct net_device *dev)
254{
255 struct parport *port =
256 ((struct net_local *)netdev_priv(dev))->pardev->port;
257
258 return port->ops->read_status (port);
259}
260
261static const struct header_ops plip_header_ops = {
262 .create = plip_hard_header,
263 .cache = plip_hard_header_cache,
264};
265
266static const struct net_device_ops plip_netdev_ops = {
267 .ndo_open = plip_open,
268 .ndo_stop = plip_close,
269 .ndo_start_xmit = plip_tx_packet,
270 .ndo_siocdevprivate = plip_siocdevprivate,
271 .ndo_set_mac_address = eth_mac_addr,
272 .ndo_validate_addr = eth_validate_addr,
273};
274
275/* Entry point of PLIP driver.
276 Probe the hardware, and register/initialize the driver.
277
278 PLIP is rather weird, because of the way it interacts with the parport
279 system. It is _not_ initialised from Space.c. Instead, plip_init()
280 is called, and that function makes up a "struct net_device" for each port, and
281 then calls us here.
282
283 */
284static void
285plip_init_netdev(struct net_device *dev)
286{
287 static const u8 addr_init[ETH_ALEN] = {
288 0xfc, 0xfc, 0xfc,
289 0xfc, 0xfc, 0xfc,
290 };
291 struct net_local *nl = netdev_priv(dev);
292
293 /* Then, override parts of it */
294 dev->tx_queue_len = 10;
295 dev->flags = IFF_POINTOPOINT|IFF_NOARP;
296 eth_hw_addr_set(dev, addr_init);
297
298 dev->netdev_ops = &plip_netdev_ops;
299 dev->header_ops = &plip_header_ops;
300
301
302 nl->port_owner = 0;
303
304 /* Initialize constants */
305 nl->trigger = PLIP_TRIGGER_WAIT;
306 nl->nibble = PLIP_NIBBLE_WAIT;
307
308 /* Initialize task queue structures */
309 INIT_WORK(&nl->immediate, plip_bh);
310 INIT_DELAYED_WORK(&nl->deferred, plip_kick_bh);
311
312 if (dev->irq == -1)
313 INIT_DELAYED_WORK(&nl->timer, plip_timer_bh);
314
315 spin_lock_init(&nl->lock);
316}
317
318/* Bottom half handler for the delayed request.
319 This routine is kicked by do_timer().
320 Request `plip_bh' to be invoked. */
321static void
322plip_kick_bh(struct work_struct *work)
323{
324 struct net_local *nl =
325 container_of(work, struct net_local, deferred.work);
326
327 if (nl->is_deferred)
328 schedule_work(&nl->immediate);
329}
330
331/* Forward declarations of internal routines */
332static int plip_none(struct net_device *, struct net_local *,
333 struct plip_local *, struct plip_local *);
334static int plip_receive_packet(struct net_device *, struct net_local *,
335 struct plip_local *, struct plip_local *);
336static int plip_send_packet(struct net_device *, struct net_local *,
337 struct plip_local *, struct plip_local *);
338static int plip_connection_close(struct net_device *, struct net_local *,
339 struct plip_local *, struct plip_local *);
340static int plip_error(struct net_device *, struct net_local *,
341 struct plip_local *, struct plip_local *);
342static int plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
343 struct plip_local *snd,
344 struct plip_local *rcv,
345 int error);
346
347#define OK 0
348#define TIMEOUT 1
349#define ERROR 2
350#define HS_TIMEOUT 3
351
352typedef int (*plip_func)(struct net_device *dev, struct net_local *nl,
353 struct plip_local *snd, struct plip_local *rcv);
354
355static const plip_func connection_state_table[] =
356{
357 plip_none,
358 plip_receive_packet,
359 plip_send_packet,
360 plip_connection_close,
361 plip_error
362};
363
364/* Bottom half handler of PLIP. */
365static void
366plip_bh(struct work_struct *work)
367{
368 struct net_local *nl = container_of(work, struct net_local, immediate);
369 struct plip_local *snd = &nl->snd_data;
370 struct plip_local *rcv = &nl->rcv_data;
371 plip_func f;
372 int r;
373
374 nl->is_deferred = 0;
375 f = connection_state_table[nl->connection];
376 if ((r = (*f)(nl->dev, nl, snd, rcv)) != OK &&
377 (r = plip_bh_timeout_error(nl->dev, nl, snd, rcv, r)) != OK) {
378 nl->is_deferred = 1;
379 schedule_delayed_work(&nl->deferred, 1);
380 }
381}
382
383static void
384plip_timer_bh(struct work_struct *work)
385{
386 struct net_local *nl =
387 container_of(work, struct net_local, timer.work);
388
389 if (!(atomic_read (&nl->kill_timer))) {
390 plip_interrupt (nl->dev);
391
392 schedule_delayed_work(&nl->timer, 1);
393 }
394 else {
395 complete(&nl->killed_timer_cmp);
396 }
397}
398
399static int
400plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
401 struct plip_local *snd, struct plip_local *rcv,
402 int error)
403{
404 unsigned char c0;
405 /*
406 * This is tricky. If we got here from the beginning of send (either
407 * with ERROR or HS_TIMEOUT) we have IRQ enabled. Otherwise it's
408 * already disabled. With the old variant of {enable,disable}_irq()
409 * extra disable_irq() was a no-op. Now it became mortal - it's
410 * unbalanced and thus we'll never re-enable IRQ (until rmmod plip,
411 * that is). So we have to treat HS_TIMEOUT and ERROR from send
412 * in a special way.
413 */
414
415 spin_lock_irq(&nl->lock);
416 if (nl->connection == PLIP_CN_SEND) {
417
418 if (error != ERROR) { /* Timeout */
419 nl->timeout_count++;
420 if ((error == HS_TIMEOUT && nl->timeout_count <= 10) ||
421 nl->timeout_count <= 3) {
422 spin_unlock_irq(&nl->lock);
423 /* Try again later */
424 return TIMEOUT;
425 }
426 c0 = read_status(dev);
427 printk(KERN_WARNING "%s: transmit timeout(%d,%02x)\n",
428 dev->name, snd->state, c0);
429 } else
430 error = HS_TIMEOUT;
431 dev->stats.tx_errors++;
432 dev->stats.tx_aborted_errors++;
433 } else if (nl->connection == PLIP_CN_RECEIVE) {
434 if (rcv->state == PLIP_PK_TRIGGER) {
435 /* Transmission was interrupted. */
436 spin_unlock_irq(&nl->lock);
437 return OK;
438 }
439 if (error != ERROR) { /* Timeout */
440 if (++nl->timeout_count <= 3) {
441 spin_unlock_irq(&nl->lock);
442 /* Try again later */
443 return TIMEOUT;
444 }
445 c0 = read_status(dev);
446 printk(KERN_WARNING "%s: receive timeout(%d,%02x)\n",
447 dev->name, rcv->state, c0);
448 }
449 dev->stats.rx_dropped++;
450 }
451 rcv->state = PLIP_PK_DONE;
452 if (rcv->skb) {
453 dev_kfree_skb_irq(rcv->skb);
454 rcv->skb = NULL;
455 }
456 snd->state = PLIP_PK_DONE;
457 if (snd->skb) {
458 dev_consume_skb_irq(snd->skb);
459 snd->skb = NULL;
460 }
461 spin_unlock_irq(&nl->lock);
462 if (error == HS_TIMEOUT) {
463 DISABLE(dev->irq);
464 synchronize_irq(dev->irq);
465 }
466 disable_parport_interrupts (dev);
467 netif_stop_queue (dev);
468 nl->connection = PLIP_CN_ERROR;
469 write_data (dev, 0x00);
470
471 return TIMEOUT;
472}
473
474static int
475plip_none(struct net_device *dev, struct net_local *nl,
476 struct plip_local *snd, struct plip_local *rcv)
477{
478 return OK;
479}
480
481/* PLIP_RECEIVE --- receive a byte(two nibbles)
482 Returns OK on success, TIMEOUT on timeout */
483static inline int
484plip_receive(unsigned short nibble_timeout, struct net_device *dev,
485 enum plip_nibble_state *ns_p, unsigned char *data_p)
486{
487 unsigned char c0, c1;
488 unsigned int cx;
489
490 switch (*ns_p) {
491 case PLIP_NB_BEGIN:
492 cx = nibble_timeout;
493 while (1) {
494 c0 = read_status(dev);
495 udelay(PLIP_DELAY_UNIT);
496 if ((c0 & 0x80) == 0) {
497 c1 = read_status(dev);
498 if (c0 == c1)
499 break;
500 }
501 if (--cx == 0)
502 return TIMEOUT;
503 }
504 *data_p = (c0 >> 3) & 0x0f;
505 write_data (dev, 0x10); /* send ACK */
506 *ns_p = PLIP_NB_1;
507 fallthrough;
508
509 case PLIP_NB_1:
510 cx = nibble_timeout;
511 while (1) {
512 c0 = read_status(dev);
513 udelay(PLIP_DELAY_UNIT);
514 if (c0 & 0x80) {
515 c1 = read_status(dev);
516 if (c0 == c1)
517 break;
518 }
519 if (--cx == 0)
520 return TIMEOUT;
521 }
522 *data_p |= (c0 << 1) & 0xf0;
523 write_data (dev, 0x00); /* send ACK */
524 *ns_p = PLIP_NB_BEGIN;
525 break;
526 case PLIP_NB_2:
527 break;
528 }
529 return OK;
530}
531
532/*
533 * Determine the packet's protocol ID. The rule here is that we
534 * assume 802.3 if the type field is short enough to be a length.
535 * This is normal practice and works for any 'now in use' protocol.
536 *
537 * PLIP is ethernet ish but the daddr might not be valid if unicast.
538 * PLIP fortunately has no bus architecture (its Point-to-point).
539 *
540 * We can't fix the daddr thing as that quirk (more bug) is embedded
541 * in far too many old systems not all even running Linux.
542 */
543
544static __be16 plip_type_trans(struct sk_buff *skb, struct net_device *dev)
545{
546 struct ethhdr *eth;
547 unsigned char *rawp;
548
549 skb_reset_mac_header(skb);
550 skb_pull(skb,dev->hard_header_len);
551 eth = eth_hdr(skb);
552
553 if(is_multicast_ether_addr(eth->h_dest))
554 {
555 if(ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
556 skb->pkt_type=PACKET_BROADCAST;
557 else
558 skb->pkt_type=PACKET_MULTICAST;
559 }
560
561 /*
562 * This ALLMULTI check should be redundant by 1.4
563 * so don't forget to remove it.
564 */
565
566 if (ntohs(eth->h_proto) >= ETH_P_802_3_MIN)
567 return eth->h_proto;
568
569 rawp = skb->data;
570
571 /*
572 * This is a magic hack to spot IPX packets. Older Novell breaks
573 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
574 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
575 * won't work for fault tolerant netware but does for the rest.
576 */
577 if (*(unsigned short *)rawp == 0xFFFF)
578 return htons(ETH_P_802_3);
579
580 /*
581 * Real 802.2 LLC
582 */
583 return htons(ETH_P_802_2);
584}
585
586/* PLIP_RECEIVE_PACKET --- receive a packet */
587static int
588plip_receive_packet(struct net_device *dev, struct net_local *nl,
589 struct plip_local *snd, struct plip_local *rcv)
590{
591 unsigned short nibble_timeout = nl->nibble;
592 unsigned char *lbuf;
593
594 switch (rcv->state) {
595 case PLIP_PK_TRIGGER:
596 DISABLE(dev->irq);
597 /* Don't need to synchronize irq, as we can safely ignore it */
598 disable_parport_interrupts (dev);
599 write_data (dev, 0x01); /* send ACK */
600 if (net_debug > 2)
601 printk(KERN_DEBUG "%s: receive start\n", dev->name);
602 rcv->state = PLIP_PK_LENGTH_LSB;
603 rcv->nibble = PLIP_NB_BEGIN;
604 fallthrough;
605
606 case PLIP_PK_LENGTH_LSB:
607 if (snd->state != PLIP_PK_DONE) {
608 if (plip_receive(nl->trigger, dev,
609 &rcv->nibble, &rcv->length.b.lsb)) {
610 /* collision, here dev->tbusy == 1 */
611 rcv->state = PLIP_PK_DONE;
612 nl->is_deferred = 1;
613 nl->connection = PLIP_CN_SEND;
614 schedule_delayed_work(&nl->deferred, 1);
615 enable_parport_interrupts (dev);
616 ENABLE(dev->irq);
617 return OK;
618 }
619 } else {
620 if (plip_receive(nibble_timeout, dev,
621 &rcv->nibble, &rcv->length.b.lsb))
622 return TIMEOUT;
623 }
624 rcv->state = PLIP_PK_LENGTH_MSB;
625 fallthrough;
626
627 case PLIP_PK_LENGTH_MSB:
628 if (plip_receive(nibble_timeout, dev,
629 &rcv->nibble, &rcv->length.b.msb))
630 return TIMEOUT;
631 if (rcv->length.h > dev->mtu + dev->hard_header_len ||
632 rcv->length.h < 8) {
633 printk(KERN_WARNING "%s: bogus packet size %d.\n", dev->name, rcv->length.h);
634 return ERROR;
635 }
636 /* Malloc up new buffer. */
637 rcv->skb = dev_alloc_skb(rcv->length.h + 2);
638 if (rcv->skb == NULL) {
639 printk(KERN_ERR "%s: Memory squeeze.\n", dev->name);
640 return ERROR;
641 }
642 skb_reserve(rcv->skb, 2); /* Align IP on 16 byte boundaries */
643 skb_put(rcv->skb,rcv->length.h);
644 rcv->skb->dev = dev;
645 rcv->state = PLIP_PK_DATA;
646 rcv->byte = 0;
647 rcv->checksum = 0;
648 fallthrough;
649
650 case PLIP_PK_DATA:
651 lbuf = rcv->skb->data;
652 do {
653 if (plip_receive(nibble_timeout, dev,
654 &rcv->nibble, &lbuf[rcv->byte]))
655 return TIMEOUT;
656 } while (++rcv->byte < rcv->length.h);
657 do {
658 rcv->checksum += lbuf[--rcv->byte];
659 } while (rcv->byte);
660 rcv->state = PLIP_PK_CHECKSUM;
661 fallthrough;
662
663 case PLIP_PK_CHECKSUM:
664 if (plip_receive(nibble_timeout, dev,
665 &rcv->nibble, &rcv->data))
666 return TIMEOUT;
667 if (rcv->data != rcv->checksum) {
668 dev->stats.rx_crc_errors++;
669 if (net_debug)
670 printk(KERN_DEBUG "%s: checksum error\n", dev->name);
671 return ERROR;
672 }
673 rcv->state = PLIP_PK_DONE;
674 fallthrough;
675
676 case PLIP_PK_DONE:
677 /* Inform the upper layer for the arrival of a packet. */
678 rcv->skb->protocol=plip_type_trans(rcv->skb, dev);
679 netif_rx(rcv->skb);
680 dev->stats.rx_bytes += rcv->length.h;
681 dev->stats.rx_packets++;
682 rcv->skb = NULL;
683 if (net_debug > 2)
684 printk(KERN_DEBUG "%s: receive end\n", dev->name);
685
686 /* Close the connection. */
687 write_data (dev, 0x00);
688 spin_lock_irq(&nl->lock);
689 if (snd->state != PLIP_PK_DONE) {
690 nl->connection = PLIP_CN_SEND;
691 spin_unlock_irq(&nl->lock);
692 schedule_work(&nl->immediate);
693 enable_parport_interrupts (dev);
694 ENABLE(dev->irq);
695 return OK;
696 } else {
697 nl->connection = PLIP_CN_NONE;
698 spin_unlock_irq(&nl->lock);
699 enable_parport_interrupts (dev);
700 ENABLE(dev->irq);
701 return OK;
702 }
703 }
704 return OK;
705}
706
707/* PLIP_SEND --- send a byte (two nibbles)
708 Returns OK on success, TIMEOUT when timeout */
709static inline int
710plip_send(unsigned short nibble_timeout, struct net_device *dev,
711 enum plip_nibble_state *ns_p, unsigned char data)
712{
713 unsigned char c0;
714 unsigned int cx;
715
716 switch (*ns_p) {
717 case PLIP_NB_BEGIN:
718 write_data (dev, data & 0x0f);
719 *ns_p = PLIP_NB_1;
720 fallthrough;
721
722 case PLIP_NB_1:
723 write_data (dev, 0x10 | (data & 0x0f));
724 cx = nibble_timeout;
725 while (1) {
726 c0 = read_status(dev);
727 if ((c0 & 0x80) == 0)
728 break;
729 if (--cx == 0)
730 return TIMEOUT;
731 udelay(PLIP_DELAY_UNIT);
732 }
733 write_data (dev, 0x10 | (data >> 4));
734 *ns_p = PLIP_NB_2;
735 fallthrough;
736
737 case PLIP_NB_2:
738 write_data (dev, (data >> 4));
739 cx = nibble_timeout;
740 while (1) {
741 c0 = read_status(dev);
742 if (c0 & 0x80)
743 break;
744 if (--cx == 0)
745 return TIMEOUT;
746 udelay(PLIP_DELAY_UNIT);
747 }
748 *ns_p = PLIP_NB_BEGIN;
749 return OK;
750 }
751 return OK;
752}
753
754/* PLIP_SEND_PACKET --- send a packet */
755static int
756plip_send_packet(struct net_device *dev, struct net_local *nl,
757 struct plip_local *snd, struct plip_local *rcv)
758{
759 unsigned short nibble_timeout = nl->nibble;
760 unsigned char *lbuf;
761 unsigned char c0;
762 unsigned int cx;
763
764 if (snd->skb == NULL || (lbuf = snd->skb->data) == NULL) {
765 printk(KERN_DEBUG "%s: send skb lost\n", dev->name);
766 snd->state = PLIP_PK_DONE;
767 snd->skb = NULL;
768 return ERROR;
769 }
770
771 switch (snd->state) {
772 case PLIP_PK_TRIGGER:
773 if ((read_status(dev) & 0xf8) != 0x80)
774 return HS_TIMEOUT;
775
776 /* Trigger remote rx interrupt. */
777 write_data (dev, 0x08);
778 cx = nl->trigger;
779 while (1) {
780 udelay(PLIP_DELAY_UNIT);
781 spin_lock_irq(&nl->lock);
782 if (nl->connection == PLIP_CN_RECEIVE) {
783 spin_unlock_irq(&nl->lock);
784 /* Interrupted. */
785 dev->stats.collisions++;
786 return OK;
787 }
788 c0 = read_status(dev);
789 if (c0 & 0x08) {
790 spin_unlock_irq(&nl->lock);
791 DISABLE(dev->irq);
792 synchronize_irq(dev->irq);
793 if (nl->connection == PLIP_CN_RECEIVE) {
794 /* Interrupted.
795 We don't need to enable irq,
796 as it is soon disabled. */
797 /* Yes, we do. New variant of
798 {enable,disable}_irq *counts*
799 them. -- AV */
800 ENABLE(dev->irq);
801 dev->stats.collisions++;
802 return OK;
803 }
804 disable_parport_interrupts (dev);
805 if (net_debug > 2)
806 printk(KERN_DEBUG "%s: send start\n", dev->name);
807 snd->state = PLIP_PK_LENGTH_LSB;
808 snd->nibble = PLIP_NB_BEGIN;
809 nl->timeout_count = 0;
810 break;
811 }
812 spin_unlock_irq(&nl->lock);
813 if (--cx == 0) {
814 write_data (dev, 0x00);
815 return HS_TIMEOUT;
816 }
817 }
818 break;
819
820 case PLIP_PK_LENGTH_LSB:
821 if (plip_send(nibble_timeout, dev,
822 &snd->nibble, snd->length.b.lsb))
823 return TIMEOUT;
824 snd->state = PLIP_PK_LENGTH_MSB;
825 fallthrough;
826
827 case PLIP_PK_LENGTH_MSB:
828 if (plip_send(nibble_timeout, dev,
829 &snd->nibble, snd->length.b.msb))
830 return TIMEOUT;
831 snd->state = PLIP_PK_DATA;
832 snd->byte = 0;
833 snd->checksum = 0;
834 fallthrough;
835
836 case PLIP_PK_DATA:
837 do {
838 if (plip_send(nibble_timeout, dev,
839 &snd->nibble, lbuf[snd->byte]))
840 return TIMEOUT;
841 } while (++snd->byte < snd->length.h);
842 do {
843 snd->checksum += lbuf[--snd->byte];
844 } while (snd->byte);
845 snd->state = PLIP_PK_CHECKSUM;
846 fallthrough;
847
848 case PLIP_PK_CHECKSUM:
849 if (plip_send(nibble_timeout, dev,
850 &snd->nibble, snd->checksum))
851 return TIMEOUT;
852
853 dev->stats.tx_bytes += snd->skb->len;
854 dev_kfree_skb(snd->skb);
855 dev->stats.tx_packets++;
856 snd->state = PLIP_PK_DONE;
857 fallthrough;
858
859 case PLIP_PK_DONE:
860 /* Close the connection */
861 write_data (dev, 0x00);
862 snd->skb = NULL;
863 if (net_debug > 2)
864 printk(KERN_DEBUG "%s: send end\n", dev->name);
865 nl->connection = PLIP_CN_CLOSING;
866 nl->is_deferred = 1;
867 schedule_delayed_work(&nl->deferred, 1);
868 enable_parport_interrupts (dev);
869 ENABLE(dev->irq);
870 return OK;
871 }
872 return OK;
873}
874
875static int
876plip_connection_close(struct net_device *dev, struct net_local *nl,
877 struct plip_local *snd, struct plip_local *rcv)
878{
879 spin_lock_irq(&nl->lock);
880 if (nl->connection == PLIP_CN_CLOSING) {
881 nl->connection = PLIP_CN_NONE;
882 netif_wake_queue (dev);
883 }
884 spin_unlock_irq(&nl->lock);
885 if (nl->should_relinquish) {
886 nl->should_relinquish = nl->port_owner = 0;
887 parport_release(nl->pardev);
888 }
889 return OK;
890}
891
892/* PLIP_ERROR --- wait till other end settled */
893static int
894plip_error(struct net_device *dev, struct net_local *nl,
895 struct plip_local *snd, struct plip_local *rcv)
896{
897 unsigned char status;
898
899 status = read_status(dev);
900 if ((status & 0xf8) == 0x80) {
901 if (net_debug > 2)
902 printk(KERN_DEBUG "%s: reset interface.\n", dev->name);
903 nl->connection = PLIP_CN_NONE;
904 nl->should_relinquish = 0;
905 netif_start_queue (dev);
906 enable_parport_interrupts (dev);
907 ENABLE(dev->irq);
908 netif_wake_queue (dev);
909 } else {
910 nl->is_deferred = 1;
911 schedule_delayed_work(&nl->deferred, 1);
912 }
913
914 return OK;
915}
916
917/* Handle the parallel port interrupts. */
918static void
919plip_interrupt(void *dev_id)
920{
921 struct net_device *dev = dev_id;
922 struct net_local *nl;
923 struct plip_local *rcv;
924 unsigned char c0;
925 unsigned long flags;
926
927 nl = netdev_priv(dev);
928 rcv = &nl->rcv_data;
929
930 spin_lock_irqsave (&nl->lock, flags);
931
932 c0 = read_status(dev);
933 if ((c0 & 0xf8) != 0xc0) {
934 if ((dev->irq != -1) && (net_debug > 1))
935 printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
936 spin_unlock_irqrestore (&nl->lock, flags);
937 return;
938 }
939
940 if (net_debug > 3)
941 printk(KERN_DEBUG "%s: interrupt.\n", dev->name);
942
943 switch (nl->connection) {
944 case PLIP_CN_CLOSING:
945 netif_wake_queue (dev);
946 fallthrough;
947 case PLIP_CN_NONE:
948 case PLIP_CN_SEND:
949 rcv->state = PLIP_PK_TRIGGER;
950 nl->connection = PLIP_CN_RECEIVE;
951 nl->timeout_count = 0;
952 schedule_work(&nl->immediate);
953 break;
954
955 case PLIP_CN_RECEIVE:
956 /* May occur because there is race condition
957 around test and set of dev->interrupt.
958 Ignore this interrupt. */
959 break;
960
961 case PLIP_CN_ERROR:
962 printk(KERN_ERR "%s: receive interrupt in error state\n", dev->name);
963 break;
964 }
965
966 spin_unlock_irqrestore(&nl->lock, flags);
967}
968
969static netdev_tx_t
970plip_tx_packet(struct sk_buff *skb, struct net_device *dev)
971{
972 struct net_local *nl = netdev_priv(dev);
973 struct plip_local *snd = &nl->snd_data;
974
975 if (netif_queue_stopped(dev))
976 return NETDEV_TX_BUSY;
977
978 /* We may need to grab the bus */
979 if (!nl->port_owner) {
980 if (parport_claim(nl->pardev))
981 return NETDEV_TX_BUSY;
982 nl->port_owner = 1;
983 }
984
985 netif_stop_queue (dev);
986
987 if (skb->len > dev->mtu + dev->hard_header_len) {
988 printk(KERN_WARNING "%s: packet too big, %d.\n", dev->name, (int)skb->len);
989 netif_start_queue (dev);
990 return NETDEV_TX_BUSY;
991 }
992
993 if (net_debug > 2)
994 printk(KERN_DEBUG "%s: send request\n", dev->name);
995
996 spin_lock_irq(&nl->lock);
997 snd->skb = skb;
998 snd->length.h = skb->len;
999 snd->state = PLIP_PK_TRIGGER;
1000 if (nl->connection == PLIP_CN_NONE) {
1001 nl->connection = PLIP_CN_SEND;
1002 nl->timeout_count = 0;
1003 }
1004 schedule_work(&nl->immediate);
1005 spin_unlock_irq(&nl->lock);
1006
1007 return NETDEV_TX_OK;
1008}
1009
1010static void
1011plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth)
1012{
1013 const struct in_device *in_dev;
1014
1015 rcu_read_lock();
1016 in_dev = __in_dev_get_rcu(dev);
1017 if (in_dev) {
1018 /* Any address will do - we take the first */
1019 const struct in_ifaddr *ifa = rcu_dereference(in_dev->ifa_list);
1020 if (ifa) {
1021 memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
1022 memset(eth->h_dest, 0xfc, 2);
1023 memcpy(eth->h_dest+2, &ifa->ifa_address, 4);
1024 }
1025 }
1026 rcu_read_unlock();
1027}
1028
1029static int
1030plip_hard_header(struct sk_buff *skb, struct net_device *dev,
1031 unsigned short type, const void *daddr,
1032 const void *saddr, unsigned len)
1033{
1034 int ret;
1035
1036 ret = eth_header(skb, dev, type, daddr, saddr, len);
1037 if (ret >= 0)
1038 plip_rewrite_address (dev, (struct ethhdr *)skb->data);
1039
1040 return ret;
1041}
1042
1043static int plip_hard_header_cache(const struct neighbour *neigh,
1044 struct hh_cache *hh, __be16 type)
1045{
1046 int ret;
1047
1048 ret = eth_header_cache(neigh, hh, type);
1049 if (ret == 0) {
1050 struct ethhdr *eth;
1051
1052 eth = (struct ethhdr*)(((u8*)hh->hh_data) +
1053 HH_DATA_OFF(sizeof(*eth)));
1054 plip_rewrite_address (neigh->dev, eth);
1055 }
1056
1057 return ret;
1058}
1059
1060/* Open/initialize the board. This is called (in the current kernel)
1061 sometime after booting when the 'ifconfig' program is run.
1062
1063 This routine gets exclusive access to the parallel port by allocating
1064 its IRQ line.
1065 */
1066static int
1067plip_open(struct net_device *dev)
1068{
1069 struct net_local *nl = netdev_priv(dev);
1070 struct in_device *in_dev;
1071
1072 /* Grab the port */
1073 if (!nl->port_owner) {
1074 if (parport_claim(nl->pardev)) return -EAGAIN;
1075 nl->port_owner = 1;
1076 }
1077
1078 nl->should_relinquish = 0;
1079
1080 /* Clear the data port. */
1081 write_data (dev, 0x00);
1082
1083 /* Enable rx interrupt. */
1084 enable_parport_interrupts (dev);
1085 if (dev->irq == -1)
1086 {
1087 atomic_set (&nl->kill_timer, 0);
1088 schedule_delayed_work(&nl->timer, 1);
1089 }
1090
1091 /* Initialize the state machine. */
1092 nl->rcv_data.state = nl->snd_data.state = PLIP_PK_DONE;
1093 nl->rcv_data.skb = nl->snd_data.skb = NULL;
1094 nl->connection = PLIP_CN_NONE;
1095 nl->is_deferred = 0;
1096
1097 /* Fill in the MAC-level header.
1098 We used to abuse dev->broadcast to store the point-to-point
1099 MAC address, but we no longer do it. Instead, we fetch the
1100 interface address whenever it is needed, which is cheap enough
1101 because we use the hh_cache. Actually, abusing dev->broadcast
1102 didn't work, because when using plip_open the point-to-point
1103 address isn't yet known.
1104 PLIP doesn't have a real MAC address, but we need it to be
1105 DOS compatible, and to properly support taps (otherwise,
1106 when the device address isn't identical to the address of a
1107 received frame, the kernel incorrectly drops it). */
1108
1109 in_dev=__in_dev_get_rtnl(dev);
1110 if (in_dev) {
1111 /* Any address will do - we take the first. We already
1112 have the first two bytes filled with 0xfc, from
1113 plip_init_dev(). */
1114 const struct in_ifaddr *ifa = rtnl_dereference(in_dev->ifa_list);
1115 if (ifa != NULL) {
1116 dev_addr_mod(dev, 2, &ifa->ifa_local, 4);
1117 }
1118 }
1119
1120 netif_start_queue (dev);
1121
1122 return 0;
1123}
1124
1125/* The inverse routine to plip_open (). */
1126static int
1127plip_close(struct net_device *dev)
1128{
1129 struct net_local *nl = netdev_priv(dev);
1130 struct plip_local *snd = &nl->snd_data;
1131 struct plip_local *rcv = &nl->rcv_data;
1132
1133 netif_stop_queue (dev);
1134 DISABLE(dev->irq);
1135 synchronize_irq(dev->irq);
1136
1137 if (dev->irq == -1)
1138 {
1139 init_completion(&nl->killed_timer_cmp);
1140 atomic_set (&nl->kill_timer, 1);
1141 wait_for_completion(&nl->killed_timer_cmp);
1142 }
1143
1144#ifdef NOTDEF
1145 outb(0x00, PAR_DATA(dev));
1146#endif
1147 nl->is_deferred = 0;
1148 nl->connection = PLIP_CN_NONE;
1149 if (nl->port_owner) {
1150 parport_release(nl->pardev);
1151 nl->port_owner = 0;
1152 }
1153
1154 snd->state = PLIP_PK_DONE;
1155 if (snd->skb) {
1156 dev_kfree_skb(snd->skb);
1157 snd->skb = NULL;
1158 }
1159 rcv->state = PLIP_PK_DONE;
1160 if (rcv->skb) {
1161 kfree_skb(rcv->skb);
1162 rcv->skb = NULL;
1163 }
1164
1165#ifdef NOTDEF
1166 /* Reset. */
1167 outb(0x00, PAR_CONTROL(dev));
1168#endif
1169 return 0;
1170}
1171
1172static int
1173plip_preempt(void *handle)
1174{
1175 struct net_device *dev = (struct net_device *)handle;
1176 struct net_local *nl = netdev_priv(dev);
1177
1178 /* Stand our ground if a datagram is on the wire */
1179 if (nl->connection != PLIP_CN_NONE) {
1180 nl->should_relinquish = 1;
1181 return 1;
1182 }
1183
1184 nl->port_owner = 0; /* Remember that we released the bus */
1185 return 0;
1186}
1187
1188static void
1189plip_wakeup(void *handle)
1190{
1191 struct net_device *dev = (struct net_device *)handle;
1192 struct net_local *nl = netdev_priv(dev);
1193
1194 if (nl->port_owner) {
1195 /* Why are we being woken up? */
1196 printk(KERN_DEBUG "%s: why am I being woken up?\n", dev->name);
1197 if (!parport_claim(nl->pardev))
1198 /* bus_owner is already set (but why?) */
1199 printk(KERN_DEBUG "%s: I'm broken.\n", dev->name);
1200 else
1201 return;
1202 }
1203
1204 if (!(dev->flags & IFF_UP))
1205 /* Don't need the port when the interface is down */
1206 return;
1207
1208 if (!parport_claim(nl->pardev)) {
1209 nl->port_owner = 1;
1210 /* Clear the data port. */
1211 write_data (dev, 0x00);
1212 }
1213}
1214
1215static int
1216plip_siocdevprivate(struct net_device *dev, struct ifreq *rq,
1217 void __user *data, int cmd)
1218{
1219 struct net_local *nl = netdev_priv(dev);
1220 struct plipconf *pc = (struct plipconf *) &rq->ifr_ifru;
1221
1222 if (cmd != SIOCDEVPLIP)
1223 return -EOPNOTSUPP;
1224
1225 if (in_compat_syscall())
1226 return -EOPNOTSUPP;
1227
1228 switch(pc->pcmd) {
1229 case PLIP_GET_TIMEOUT:
1230 pc->trigger = nl->trigger;
1231 pc->nibble = nl->nibble;
1232 break;
1233 case PLIP_SET_TIMEOUT:
1234 if(!capable(CAP_NET_ADMIN))
1235 return -EPERM;
1236 nl->trigger = pc->trigger;
1237 nl->nibble = pc->nibble;
1238 break;
1239 default:
1240 return -EOPNOTSUPP;
1241 }
1242 return 0;
1243}
1244
1245static int parport[PLIP_MAX] = { [0 ... PLIP_MAX-1] = -1 };
1246static int timid;
1247
1248module_param_array(parport, int, NULL, 0);
1249module_param(timid, int, 0);
1250MODULE_PARM_DESC(parport, "List of parport device numbers to use by plip");
1251
1252static struct net_device *dev_plip[PLIP_MAX] = { NULL, };
1253
1254static inline int
1255plip_searchfor(int list[], int a)
1256{
1257 int i;
1258 for (i = 0; i < PLIP_MAX && list[i] != -1; i++) {
1259 if (list[i] == a) return 1;
1260 }
1261 return 0;
1262}
1263
1264/* plip_attach() is called (by the parport code) when a port is
1265 * available to use. */
1266static void plip_attach (struct parport *port)
1267{
1268 static int unit;
1269 struct net_device *dev;
1270 struct net_local *nl;
1271 char name[IFNAMSIZ];
1272 struct pardev_cb plip_cb;
1273
1274 if ((parport[0] == -1 && (!timid || !port->devices)) ||
1275 plip_searchfor(parport, port->number)) {
1276 if (unit == PLIP_MAX) {
1277 printk(KERN_ERR "plip: too many devices\n");
1278 return;
1279 }
1280
1281 sprintf(name, "plip%d", unit);
1282 dev = alloc_etherdev(sizeof(struct net_local));
1283 if (!dev)
1284 return;
1285
1286 strcpy(dev->name, name);
1287
1288 dev->irq = port->irq;
1289 dev->base_addr = port->base;
1290 if (port->irq == -1) {
1291 printk(KERN_INFO "plip: %s has no IRQ. Using IRQ-less mode,"
1292 "which is fairly inefficient!\n", port->name);
1293 }
1294
1295 nl = netdev_priv(dev);
1296 nl->dev = dev;
1297
1298 memset(&plip_cb, 0, sizeof(plip_cb));
1299 plip_cb.private = dev;
1300 plip_cb.preempt = plip_preempt;
1301 plip_cb.wakeup = plip_wakeup;
1302 plip_cb.irq_func = plip_interrupt;
1303
1304 nl->pardev = parport_register_dev_model(port, dev->name,
1305 &plip_cb, unit);
1306
1307 if (!nl->pardev) {
1308 printk(KERN_ERR "%s: parport_register failed\n", name);
1309 goto err_free_dev;
1310 }
1311
1312 plip_init_netdev(dev);
1313
1314 if (register_netdev(dev)) {
1315 printk(KERN_ERR "%s: network register failed\n", name);
1316 goto err_parport_unregister;
1317 }
1318
1319 printk(KERN_INFO "%s", version);
1320 if (dev->irq != -1)
1321 printk(KERN_INFO "%s: Parallel port at %#3lx, "
1322 "using IRQ %d.\n",
1323 dev->name, dev->base_addr, dev->irq);
1324 else
1325 printk(KERN_INFO "%s: Parallel port at %#3lx, "
1326 "not using IRQ.\n",
1327 dev->name, dev->base_addr);
1328 dev_plip[unit++] = dev;
1329 }
1330 return;
1331
1332err_parport_unregister:
1333 parport_unregister_device(nl->pardev);
1334err_free_dev:
1335 free_netdev(dev);
1336}
1337
1338/* plip_detach() is called (by the parport code) when a port is
1339 * no longer available to use. */
1340static void plip_detach (struct parport *port)
1341{
1342 /* Nothing to do */
1343}
1344
1345static int plip_probe(struct pardevice *par_dev)
1346{
1347 struct device_driver *drv = par_dev->dev.driver;
1348 int len = strlen(drv->name);
1349
1350 if (strncmp(par_dev->name, drv->name, len))
1351 return -ENODEV;
1352
1353 return 0;
1354}
1355
1356static struct parport_driver plip_driver = {
1357 .name = "plip",
1358 .probe = plip_probe,
1359 .match_port = plip_attach,
1360 .detach = plip_detach,
1361 .devmodel = true,
1362};
1363
1364static void __exit plip_cleanup_module (void)
1365{
1366 struct net_device *dev;
1367 int i;
1368
1369 for (i=0; i < PLIP_MAX; i++) {
1370 if ((dev = dev_plip[i])) {
1371 struct net_local *nl = netdev_priv(dev);
1372 unregister_netdev(dev);
1373 if (nl->port_owner)
1374 parport_release(nl->pardev);
1375 parport_unregister_device(nl->pardev);
1376 free_netdev(dev);
1377 dev_plip[i] = NULL;
1378 }
1379 }
1380
1381 parport_unregister_driver(&plip_driver);
1382}
1383
1384#ifndef MODULE
1385
1386static int parport_ptr;
1387
1388static int __init plip_setup(char *str)
1389{
1390 int ints[4];
1391
1392 str = get_options(str, ARRAY_SIZE(ints), ints);
1393
1394 /* Ugh. */
1395 if (!strncmp(str, "parport", 7)) {
1396 int n = simple_strtoul(str+7, NULL, 10);
1397 if (parport_ptr < PLIP_MAX)
1398 parport[parport_ptr++] = n;
1399 else
1400 printk(KERN_INFO "plip: too many ports, %s ignored.\n",
1401 str);
1402 } else if (!strcmp(str, "timid")) {
1403 timid = 1;
1404 } else {
1405 if (ints[0] == 0 || ints[1] == 0) {
1406 /* disable driver on "plip=" or "plip=0" */
1407 parport[0] = -2;
1408 } else {
1409 printk(KERN_WARNING "warning: 'plip=0x%x' ignored\n",
1410 ints[1]);
1411 }
1412 }
1413 return 1;
1414}
1415
1416__setup("plip=", plip_setup);
1417
1418#endif /* !MODULE */
1419
1420static int __init plip_init (void)
1421{
1422 if (parport[0] == -2)
1423 return 0;
1424
1425 if (parport[0] != -1 && timid) {
1426 printk(KERN_WARNING "plip: warning, ignoring `timid' since specific ports given.\n");
1427 timid = 0;
1428 }
1429
1430 if (parport_register_driver (&plip_driver)) {
1431 printk (KERN_WARNING "plip: couldn't register driver\n");
1432 return 1;
1433 }
1434
1435 return 0;
1436}
1437
1438module_init(plip_init);
1439module_exit(plip_cleanup_module);
1440MODULE_DESCRIPTION("PLIP (parallel port) network module");
1441MODULE_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_change_mtu = eth_change_mtu,
274 .ndo_set_mac_address = eth_mac_addr,
275 .ndo_validate_addr = eth_validate_addr,
276};
277
278/* Entry point of PLIP driver.
279 Probe the hardware, and register/initialize the driver.
280
281 PLIP is rather weird, because of the way it interacts with the parport
282 system. It is _not_ initialised from Space.c. Instead, plip_init()
283 is called, and that function makes up a "struct net_device" for each port, and
284 then calls us here.
285
286 */
287static void
288plip_init_netdev(struct net_device *dev)
289{
290 struct net_local *nl = netdev_priv(dev);
291
292 /* Then, override parts of it */
293 dev->tx_queue_len = 10;
294 dev->flags = IFF_POINTOPOINT|IFF_NOARP;
295 memset(dev->dev_addr, 0xfc, ETH_ALEN);
296
297 dev->netdev_ops = &plip_netdev_ops;
298 dev->header_ops = &plip_header_ops;
299
300
301 nl->port_owner = 0;
302
303 /* Initialize constants */
304 nl->trigger = PLIP_TRIGGER_WAIT;
305 nl->nibble = PLIP_NIBBLE_WAIT;
306
307 /* Initialize task queue structures */
308 INIT_WORK(&nl->immediate, plip_bh);
309 INIT_DELAYED_WORK(&nl->deferred, plip_kick_bh);
310
311 if (dev->irq == -1)
312 INIT_DELAYED_WORK(&nl->timer, plip_timer_bh);
313
314 spin_lock_init(&nl->lock);
315}
316
317/* Bottom half handler for the delayed request.
318 This routine is kicked by do_timer().
319 Request `plip_bh' to be invoked. */
320static void
321plip_kick_bh(struct work_struct *work)
322{
323 struct net_local *nl =
324 container_of(work, struct net_local, deferred.work);
325
326 if (nl->is_deferred)
327 schedule_work(&nl->immediate);
328}
329
330/* Forward declarations of internal routines */
331static int plip_none(struct net_device *, struct net_local *,
332 struct plip_local *, struct plip_local *);
333static int plip_receive_packet(struct net_device *, struct net_local *,
334 struct plip_local *, struct plip_local *);
335static int plip_send_packet(struct net_device *, struct net_local *,
336 struct plip_local *, struct plip_local *);
337static int plip_connection_close(struct net_device *, struct net_local *,
338 struct plip_local *, struct plip_local *);
339static int plip_error(struct net_device *, struct net_local *,
340 struct plip_local *, struct plip_local *);
341static int plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
342 struct plip_local *snd,
343 struct plip_local *rcv,
344 int error);
345
346#define OK 0
347#define TIMEOUT 1
348#define ERROR 2
349#define HS_TIMEOUT 3
350
351typedef int (*plip_func)(struct net_device *dev, struct net_local *nl,
352 struct plip_local *snd, struct plip_local *rcv);
353
354static const plip_func connection_state_table[] =
355{
356 plip_none,
357 plip_receive_packet,
358 plip_send_packet,
359 plip_connection_close,
360 plip_error
361};
362
363/* Bottom half handler of PLIP. */
364static void
365plip_bh(struct work_struct *work)
366{
367 struct net_local *nl = container_of(work, struct net_local, immediate);
368 struct plip_local *snd = &nl->snd_data;
369 struct plip_local *rcv = &nl->rcv_data;
370 plip_func f;
371 int r;
372
373 nl->is_deferred = 0;
374 f = connection_state_table[nl->connection];
375 if ((r = (*f)(nl->dev, nl, snd, rcv)) != OK &&
376 (r = plip_bh_timeout_error(nl->dev, nl, snd, rcv, r)) != OK) {
377 nl->is_deferred = 1;
378 schedule_delayed_work(&nl->deferred, 1);
379 }
380}
381
382static void
383plip_timer_bh(struct work_struct *work)
384{
385 struct net_local *nl =
386 container_of(work, struct net_local, timer.work);
387
388 if (!(atomic_read (&nl->kill_timer))) {
389 plip_interrupt (nl->dev);
390
391 schedule_delayed_work(&nl->timer, 1);
392 }
393 else {
394 complete(&nl->killed_timer_cmp);
395 }
396}
397
398static int
399plip_bh_timeout_error(struct net_device *dev, struct net_local *nl,
400 struct plip_local *snd, struct plip_local *rcv,
401 int error)
402{
403 unsigned char c0;
404 /*
405 * This is tricky. If we got here from the beginning of send (either
406 * with ERROR or HS_TIMEOUT) we have IRQ enabled. Otherwise it's
407 * already disabled. With the old variant of {enable,disable}_irq()
408 * extra disable_irq() was a no-op. Now it became mortal - it's
409 * unbalanced and thus we'll never re-enable IRQ (until rmmod plip,
410 * that is). So we have to treat HS_TIMEOUT and ERROR from send
411 * in a special way.
412 */
413
414 spin_lock_irq(&nl->lock);
415 if (nl->connection == PLIP_CN_SEND) {
416
417 if (error != ERROR) { /* Timeout */
418 nl->timeout_count++;
419 if ((error == HS_TIMEOUT && nl->timeout_count <= 10) ||
420 nl->timeout_count <= 3) {
421 spin_unlock_irq(&nl->lock);
422 /* Try again later */
423 return TIMEOUT;
424 }
425 c0 = read_status(dev);
426 printk(KERN_WARNING "%s: transmit timeout(%d,%02x)\n",
427 dev->name, snd->state, c0);
428 } else
429 error = HS_TIMEOUT;
430 dev->stats.tx_errors++;
431 dev->stats.tx_aborted_errors++;
432 } else if (nl->connection == PLIP_CN_RECEIVE) {
433 if (rcv->state == PLIP_PK_TRIGGER) {
434 /* Transmission was interrupted. */
435 spin_unlock_irq(&nl->lock);
436 return OK;
437 }
438 if (error != ERROR) { /* Timeout */
439 if (++nl->timeout_count <= 3) {
440 spin_unlock_irq(&nl->lock);
441 /* Try again later */
442 return TIMEOUT;
443 }
444 c0 = read_status(dev);
445 printk(KERN_WARNING "%s: receive timeout(%d,%02x)\n",
446 dev->name, rcv->state, c0);
447 }
448 dev->stats.rx_dropped++;
449 }
450 rcv->state = PLIP_PK_DONE;
451 if (rcv->skb) {
452 kfree_skb(rcv->skb);
453 rcv->skb = NULL;
454 }
455 snd->state = PLIP_PK_DONE;
456 if (snd->skb) {
457 dev_kfree_skb(snd->skb);
458 snd->skb = NULL;
459 }
460 spin_unlock_irq(&nl->lock);
461 if (error == HS_TIMEOUT) {
462 DISABLE(dev->irq);
463 synchronize_irq(dev->irq);
464 }
465 disable_parport_interrupts (dev);
466 netif_stop_queue (dev);
467 nl->connection = PLIP_CN_ERROR;
468 write_data (dev, 0x00);
469
470 return TIMEOUT;
471}
472
473static int
474plip_none(struct net_device *dev, struct net_local *nl,
475 struct plip_local *snd, struct plip_local *rcv)
476{
477 return OK;
478}
479
480/* PLIP_RECEIVE --- receive a byte(two nibbles)
481 Returns OK on success, TIMEOUT on timeout */
482static inline int
483plip_receive(unsigned short nibble_timeout, struct net_device *dev,
484 enum plip_nibble_state *ns_p, unsigned char *data_p)
485{
486 unsigned char c0, c1;
487 unsigned int cx;
488
489 switch (*ns_p) {
490 case PLIP_NB_BEGIN:
491 cx = nibble_timeout;
492 while (1) {
493 c0 = read_status(dev);
494 udelay(PLIP_DELAY_UNIT);
495 if ((c0 & 0x80) == 0) {
496 c1 = read_status(dev);
497 if (c0 == c1)
498 break;
499 }
500 if (--cx == 0)
501 return TIMEOUT;
502 }
503 *data_p = (c0 >> 3) & 0x0f;
504 write_data (dev, 0x10); /* send ACK */
505 *ns_p = PLIP_NB_1;
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(*eth->h_dest&1)
551 {
552 if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0)
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) >= 1536)
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
602 case PLIP_PK_LENGTH_LSB:
603 if (snd->state != PLIP_PK_DONE) {
604 if (plip_receive(nl->trigger, dev,
605 &rcv->nibble, &rcv->length.b.lsb)) {
606 /* collision, here dev->tbusy == 1 */
607 rcv->state = PLIP_PK_DONE;
608 nl->is_deferred = 1;
609 nl->connection = PLIP_CN_SEND;
610 schedule_delayed_work(&nl->deferred, 1);
611 enable_parport_interrupts (dev);
612 ENABLE(dev->irq);
613 return OK;
614 }
615 } else {
616 if (plip_receive(nibble_timeout, dev,
617 &rcv->nibble, &rcv->length.b.lsb))
618 return TIMEOUT;
619 }
620 rcv->state = PLIP_PK_LENGTH_MSB;
621
622 case PLIP_PK_LENGTH_MSB:
623 if (plip_receive(nibble_timeout, dev,
624 &rcv->nibble, &rcv->length.b.msb))
625 return TIMEOUT;
626 if (rcv->length.h > dev->mtu + dev->hard_header_len ||
627 rcv->length.h < 8) {
628 printk(KERN_WARNING "%s: bogus packet size %d.\n", dev->name, rcv->length.h);
629 return ERROR;
630 }
631 /* Malloc up new buffer. */
632 rcv->skb = dev_alloc_skb(rcv->length.h + 2);
633 if (rcv->skb == NULL) {
634 printk(KERN_ERR "%s: Memory squeeze.\n", dev->name);
635 return ERROR;
636 }
637 skb_reserve(rcv->skb, 2); /* Align IP on 16 byte boundaries */
638 skb_put(rcv->skb,rcv->length.h);
639 rcv->skb->dev = dev;
640 rcv->state = PLIP_PK_DATA;
641 rcv->byte = 0;
642 rcv->checksum = 0;
643
644 case PLIP_PK_DATA:
645 lbuf = rcv->skb->data;
646 do {
647 if (plip_receive(nibble_timeout, dev,
648 &rcv->nibble, &lbuf[rcv->byte]))
649 return TIMEOUT;
650 } while (++rcv->byte < rcv->length.h);
651 do {
652 rcv->checksum += lbuf[--rcv->byte];
653 } while (rcv->byte);
654 rcv->state = PLIP_PK_CHECKSUM;
655
656 case PLIP_PK_CHECKSUM:
657 if (plip_receive(nibble_timeout, dev,
658 &rcv->nibble, &rcv->data))
659 return TIMEOUT;
660 if (rcv->data != rcv->checksum) {
661 dev->stats.rx_crc_errors++;
662 if (net_debug)
663 printk(KERN_DEBUG "%s: checksum error\n", dev->name);
664 return ERROR;
665 }
666 rcv->state = PLIP_PK_DONE;
667
668 case PLIP_PK_DONE:
669 /* Inform the upper layer for the arrival of a packet. */
670 rcv->skb->protocol=plip_type_trans(rcv->skb, dev);
671 netif_rx_ni(rcv->skb);
672 dev->stats.rx_bytes += rcv->length.h;
673 dev->stats.rx_packets++;
674 rcv->skb = NULL;
675 if (net_debug > 2)
676 printk(KERN_DEBUG "%s: receive end\n", dev->name);
677
678 /* Close the connection. */
679 write_data (dev, 0x00);
680 spin_lock_irq(&nl->lock);
681 if (snd->state != PLIP_PK_DONE) {
682 nl->connection = PLIP_CN_SEND;
683 spin_unlock_irq(&nl->lock);
684 schedule_work(&nl->immediate);
685 enable_parport_interrupts (dev);
686 ENABLE(dev->irq);
687 return OK;
688 } else {
689 nl->connection = PLIP_CN_NONE;
690 spin_unlock_irq(&nl->lock);
691 enable_parport_interrupts (dev);
692 ENABLE(dev->irq);
693 return OK;
694 }
695 }
696 return OK;
697}
698
699/* PLIP_SEND --- send a byte (two nibbles)
700 Returns OK on success, TIMEOUT when timeout */
701static inline int
702plip_send(unsigned short nibble_timeout, struct net_device *dev,
703 enum plip_nibble_state *ns_p, unsigned char data)
704{
705 unsigned char c0;
706 unsigned int cx;
707
708 switch (*ns_p) {
709 case PLIP_NB_BEGIN:
710 write_data (dev, data & 0x0f);
711 *ns_p = PLIP_NB_1;
712
713 case PLIP_NB_1:
714 write_data (dev, 0x10 | (data & 0x0f));
715 cx = nibble_timeout;
716 while (1) {
717 c0 = read_status(dev);
718 if ((c0 & 0x80) == 0)
719 break;
720 if (--cx == 0)
721 return TIMEOUT;
722 udelay(PLIP_DELAY_UNIT);
723 }
724 write_data (dev, 0x10 | (data >> 4));
725 *ns_p = PLIP_NB_2;
726
727 case PLIP_NB_2:
728 write_data (dev, (data >> 4));
729 cx = nibble_timeout;
730 while (1) {
731 c0 = read_status(dev);
732 if (c0 & 0x80)
733 break;
734 if (--cx == 0)
735 return TIMEOUT;
736 udelay(PLIP_DELAY_UNIT);
737 }
738 *ns_p = PLIP_NB_BEGIN;
739 return OK;
740 }
741 return OK;
742}
743
744/* PLIP_SEND_PACKET --- send a packet */
745static int
746plip_send_packet(struct net_device *dev, struct net_local *nl,
747 struct plip_local *snd, struct plip_local *rcv)
748{
749 unsigned short nibble_timeout = nl->nibble;
750 unsigned char *lbuf;
751 unsigned char c0;
752 unsigned int cx;
753
754 if (snd->skb == NULL || (lbuf = snd->skb->data) == NULL) {
755 printk(KERN_DEBUG "%s: send skb lost\n", dev->name);
756 snd->state = PLIP_PK_DONE;
757 snd->skb = NULL;
758 return ERROR;
759 }
760
761 switch (snd->state) {
762 case PLIP_PK_TRIGGER:
763 if ((read_status(dev) & 0xf8) != 0x80)
764 return HS_TIMEOUT;
765
766 /* Trigger remote rx interrupt. */
767 write_data (dev, 0x08);
768 cx = nl->trigger;
769 while (1) {
770 udelay(PLIP_DELAY_UNIT);
771 spin_lock_irq(&nl->lock);
772 if (nl->connection == PLIP_CN_RECEIVE) {
773 spin_unlock_irq(&nl->lock);
774 /* Interrupted. */
775 dev->stats.collisions++;
776 return OK;
777 }
778 c0 = read_status(dev);
779 if (c0 & 0x08) {
780 spin_unlock_irq(&nl->lock);
781 DISABLE(dev->irq);
782 synchronize_irq(dev->irq);
783 if (nl->connection == PLIP_CN_RECEIVE) {
784 /* Interrupted.
785 We don't need to enable irq,
786 as it is soon disabled. */
787 /* Yes, we do. New variant of
788 {enable,disable}_irq *counts*
789 them. -- AV */
790 ENABLE(dev->irq);
791 dev->stats.collisions++;
792 return OK;
793 }
794 disable_parport_interrupts (dev);
795 if (net_debug > 2)
796 printk(KERN_DEBUG "%s: send start\n", dev->name);
797 snd->state = PLIP_PK_LENGTH_LSB;
798 snd->nibble = PLIP_NB_BEGIN;
799 nl->timeout_count = 0;
800 break;
801 }
802 spin_unlock_irq(&nl->lock);
803 if (--cx == 0) {
804 write_data (dev, 0x00);
805 return HS_TIMEOUT;
806 }
807 }
808
809 case PLIP_PK_LENGTH_LSB:
810 if (plip_send(nibble_timeout, dev,
811 &snd->nibble, snd->length.b.lsb))
812 return TIMEOUT;
813 snd->state = PLIP_PK_LENGTH_MSB;
814
815 case PLIP_PK_LENGTH_MSB:
816 if (plip_send(nibble_timeout, dev,
817 &snd->nibble, snd->length.b.msb))
818 return TIMEOUT;
819 snd->state = PLIP_PK_DATA;
820 snd->byte = 0;
821 snd->checksum = 0;
822
823 case PLIP_PK_DATA:
824 do {
825 if (plip_send(nibble_timeout, dev,
826 &snd->nibble, lbuf[snd->byte]))
827 return TIMEOUT;
828 } while (++snd->byte < snd->length.h);
829 do {
830 snd->checksum += lbuf[--snd->byte];
831 } while (snd->byte);
832 snd->state = PLIP_PK_CHECKSUM;
833
834 case PLIP_PK_CHECKSUM:
835 if (plip_send(nibble_timeout, dev,
836 &snd->nibble, snd->checksum))
837 return TIMEOUT;
838
839 dev->stats.tx_bytes += snd->skb->len;
840 dev_kfree_skb(snd->skb);
841 dev->stats.tx_packets++;
842 snd->state = PLIP_PK_DONE;
843
844 case PLIP_PK_DONE:
845 /* Close the connection */
846 write_data (dev, 0x00);
847 snd->skb = NULL;
848 if (net_debug > 2)
849 printk(KERN_DEBUG "%s: send end\n", dev->name);
850 nl->connection = PLIP_CN_CLOSING;
851 nl->is_deferred = 1;
852 schedule_delayed_work(&nl->deferred, 1);
853 enable_parport_interrupts (dev);
854 ENABLE(dev->irq);
855 return OK;
856 }
857 return OK;
858}
859
860static int
861plip_connection_close(struct net_device *dev, struct net_local *nl,
862 struct plip_local *snd, struct plip_local *rcv)
863{
864 spin_lock_irq(&nl->lock);
865 if (nl->connection == PLIP_CN_CLOSING) {
866 nl->connection = PLIP_CN_NONE;
867 netif_wake_queue (dev);
868 }
869 spin_unlock_irq(&nl->lock);
870 if (nl->should_relinquish) {
871 nl->should_relinquish = nl->port_owner = 0;
872 parport_release(nl->pardev);
873 }
874 return OK;
875}
876
877/* PLIP_ERROR --- wait till other end settled */
878static int
879plip_error(struct net_device *dev, struct net_local *nl,
880 struct plip_local *snd, struct plip_local *rcv)
881{
882 unsigned char status;
883
884 status = read_status(dev);
885 if ((status & 0xf8) == 0x80) {
886 if (net_debug > 2)
887 printk(KERN_DEBUG "%s: reset interface.\n", dev->name);
888 nl->connection = PLIP_CN_NONE;
889 nl->should_relinquish = 0;
890 netif_start_queue (dev);
891 enable_parport_interrupts (dev);
892 ENABLE(dev->irq);
893 netif_wake_queue (dev);
894 } else {
895 nl->is_deferred = 1;
896 schedule_delayed_work(&nl->deferred, 1);
897 }
898
899 return OK;
900}
901
902/* Handle the parallel port interrupts. */
903static void
904plip_interrupt(void *dev_id)
905{
906 struct net_device *dev = dev_id;
907 struct net_local *nl;
908 struct plip_local *rcv;
909 unsigned char c0;
910 unsigned long flags;
911
912 nl = netdev_priv(dev);
913 rcv = &nl->rcv_data;
914
915 spin_lock_irqsave (&nl->lock, flags);
916
917 c0 = read_status(dev);
918 if ((c0 & 0xf8) != 0xc0) {
919 if ((dev->irq != -1) && (net_debug > 1))
920 printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
921 spin_unlock_irqrestore (&nl->lock, flags);
922 return;
923 }
924
925 if (net_debug > 3)
926 printk(KERN_DEBUG "%s: interrupt.\n", dev->name);
927
928 switch (nl->connection) {
929 case PLIP_CN_CLOSING:
930 netif_wake_queue (dev);
931 case PLIP_CN_NONE:
932 case PLIP_CN_SEND:
933 rcv->state = PLIP_PK_TRIGGER;
934 nl->connection = PLIP_CN_RECEIVE;
935 nl->timeout_count = 0;
936 schedule_work(&nl->immediate);
937 break;
938
939 case PLIP_CN_RECEIVE:
940 /* May occur because there is race condition
941 around test and set of dev->interrupt.
942 Ignore this interrupt. */
943 break;
944
945 case PLIP_CN_ERROR:
946 printk(KERN_ERR "%s: receive interrupt in error state\n", dev->name);
947 break;
948 }
949
950 spin_unlock_irqrestore(&nl->lock, flags);
951}
952
953static int
954plip_tx_packet(struct sk_buff *skb, struct net_device *dev)
955{
956 struct net_local *nl = netdev_priv(dev);
957 struct plip_local *snd = &nl->snd_data;
958
959 if (netif_queue_stopped(dev))
960 return NETDEV_TX_BUSY;
961
962 /* We may need to grab the bus */
963 if (!nl->port_owner) {
964 if (parport_claim(nl->pardev))
965 return NETDEV_TX_BUSY;
966 nl->port_owner = 1;
967 }
968
969 netif_stop_queue (dev);
970
971 if (skb->len > dev->mtu + dev->hard_header_len) {
972 printk(KERN_WARNING "%s: packet too big, %d.\n", dev->name, (int)skb->len);
973 netif_start_queue (dev);
974 return NETDEV_TX_BUSY;
975 }
976
977 if (net_debug > 2)
978 printk(KERN_DEBUG "%s: send request\n", dev->name);
979
980 spin_lock_irq(&nl->lock);
981 snd->skb = skb;
982 snd->length.h = skb->len;
983 snd->state = PLIP_PK_TRIGGER;
984 if (nl->connection == PLIP_CN_NONE) {
985 nl->connection = PLIP_CN_SEND;
986 nl->timeout_count = 0;
987 }
988 schedule_work(&nl->immediate);
989 spin_unlock_irq(&nl->lock);
990
991 return NETDEV_TX_OK;
992}
993
994static void
995plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth)
996{
997 const struct in_device *in_dev;
998
999 rcu_read_lock();
1000 in_dev = __in_dev_get_rcu(dev);
1001 if (in_dev) {
1002 /* Any address will do - we take the first */
1003 const struct in_ifaddr *ifa = in_dev->ifa_list;
1004 if (ifa) {
1005 memcpy(eth->h_source, dev->dev_addr, 6);
1006 memset(eth->h_dest, 0xfc, 2);
1007 memcpy(eth->h_dest+2, &ifa->ifa_address, 4);
1008 }
1009 }
1010 rcu_read_unlock();
1011}
1012
1013static int
1014plip_hard_header(struct sk_buff *skb, struct net_device *dev,
1015 unsigned short type, const void *daddr,
1016 const void *saddr, unsigned len)
1017{
1018 int ret;
1019
1020 ret = eth_header(skb, dev, type, daddr, saddr, len);
1021 if (ret >= 0)
1022 plip_rewrite_address (dev, (struct ethhdr *)skb->data);
1023
1024 return ret;
1025}
1026
1027static int plip_hard_header_cache(const struct neighbour *neigh,
1028 struct hh_cache *hh, __be16 type)
1029{
1030 int ret;
1031
1032 ret = eth_header_cache(neigh, hh, type);
1033 if (ret == 0) {
1034 struct ethhdr *eth;
1035
1036 eth = (struct ethhdr*)(((u8*)hh->hh_data) +
1037 HH_DATA_OFF(sizeof(*eth)));
1038 plip_rewrite_address (neigh->dev, eth);
1039 }
1040
1041 return ret;
1042}
1043
1044/* Open/initialize the board. This is called (in the current kernel)
1045 sometime after booting when the 'ifconfig' program is run.
1046
1047 This routine gets exclusive access to the parallel port by allocating
1048 its IRQ line.
1049 */
1050static int
1051plip_open(struct net_device *dev)
1052{
1053 struct net_local *nl = netdev_priv(dev);
1054 struct in_device *in_dev;
1055
1056 /* Grab the port */
1057 if (!nl->port_owner) {
1058 if (parport_claim(nl->pardev)) return -EAGAIN;
1059 nl->port_owner = 1;
1060 }
1061
1062 nl->should_relinquish = 0;
1063
1064 /* Clear the data port. */
1065 write_data (dev, 0x00);
1066
1067 /* Enable rx interrupt. */
1068 enable_parport_interrupts (dev);
1069 if (dev->irq == -1)
1070 {
1071 atomic_set (&nl->kill_timer, 0);
1072 schedule_delayed_work(&nl->timer, 1);
1073 }
1074
1075 /* Initialize the state machine. */
1076 nl->rcv_data.state = nl->snd_data.state = PLIP_PK_DONE;
1077 nl->rcv_data.skb = nl->snd_data.skb = NULL;
1078 nl->connection = PLIP_CN_NONE;
1079 nl->is_deferred = 0;
1080
1081 /* Fill in the MAC-level header.
1082 We used to abuse dev->broadcast to store the point-to-point
1083 MAC address, but we no longer do it. Instead, we fetch the
1084 interface address whenever it is needed, which is cheap enough
1085 because we use the hh_cache. Actually, abusing dev->broadcast
1086 didn't work, because when using plip_open the point-to-point
1087 address isn't yet known.
1088 PLIP doesn't have a real MAC address, but we need it to be
1089 DOS compatible, and to properly support taps (otherwise,
1090 when the device address isn't identical to the address of a
1091 received frame, the kernel incorrectly drops it). */
1092
1093 in_dev=__in_dev_get_rtnl(dev);
1094 if (in_dev) {
1095 /* Any address will do - we take the first. We already
1096 have the first two bytes filled with 0xfc, from
1097 plip_init_dev(). */
1098 struct in_ifaddr *ifa=in_dev->ifa_list;
1099 if (ifa != NULL) {
1100 memcpy(dev->dev_addr+2, &ifa->ifa_local, 4);
1101 }
1102 }
1103
1104 netif_start_queue (dev);
1105
1106 return 0;
1107}
1108
1109/* The inverse routine to plip_open (). */
1110static int
1111plip_close(struct net_device *dev)
1112{
1113 struct net_local *nl = netdev_priv(dev);
1114 struct plip_local *snd = &nl->snd_data;
1115 struct plip_local *rcv = &nl->rcv_data;
1116
1117 netif_stop_queue (dev);
1118 DISABLE(dev->irq);
1119 synchronize_irq(dev->irq);
1120
1121 if (dev->irq == -1)
1122 {
1123 init_completion(&nl->killed_timer_cmp);
1124 atomic_set (&nl->kill_timer, 1);
1125 wait_for_completion(&nl->killed_timer_cmp);
1126 }
1127
1128#ifdef NOTDEF
1129 outb(0x00, PAR_DATA(dev));
1130#endif
1131 nl->is_deferred = 0;
1132 nl->connection = PLIP_CN_NONE;
1133 if (nl->port_owner) {
1134 parport_release(nl->pardev);
1135 nl->port_owner = 0;
1136 }
1137
1138 snd->state = PLIP_PK_DONE;
1139 if (snd->skb) {
1140 dev_kfree_skb(snd->skb);
1141 snd->skb = NULL;
1142 }
1143 rcv->state = PLIP_PK_DONE;
1144 if (rcv->skb) {
1145 kfree_skb(rcv->skb);
1146 rcv->skb = NULL;
1147 }
1148
1149#ifdef NOTDEF
1150 /* Reset. */
1151 outb(0x00, PAR_CONTROL(dev));
1152#endif
1153 return 0;
1154}
1155
1156static int
1157plip_preempt(void *handle)
1158{
1159 struct net_device *dev = (struct net_device *)handle;
1160 struct net_local *nl = netdev_priv(dev);
1161
1162 /* Stand our ground if a datagram is on the wire */
1163 if (nl->connection != PLIP_CN_NONE) {
1164 nl->should_relinquish = 1;
1165 return 1;
1166 }
1167
1168 nl->port_owner = 0; /* Remember that we released the bus */
1169 return 0;
1170}
1171
1172static void
1173plip_wakeup(void *handle)
1174{
1175 struct net_device *dev = (struct net_device *)handle;
1176 struct net_local *nl = netdev_priv(dev);
1177
1178 if (nl->port_owner) {
1179 /* Why are we being woken up? */
1180 printk(KERN_DEBUG "%s: why am I being woken up?\n", dev->name);
1181 if (!parport_claim(nl->pardev))
1182 /* bus_owner is already set (but why?) */
1183 printk(KERN_DEBUG "%s: I'm broken.\n", dev->name);
1184 else
1185 return;
1186 }
1187
1188 if (!(dev->flags & IFF_UP))
1189 /* Don't need the port when the interface is down */
1190 return;
1191
1192 if (!parport_claim(nl->pardev)) {
1193 nl->port_owner = 1;
1194 /* Clear the data port. */
1195 write_data (dev, 0x00);
1196 }
1197}
1198
1199static int
1200plip_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
1201{
1202 struct net_local *nl = netdev_priv(dev);
1203 struct plipconf *pc = (struct plipconf *) &rq->ifr_ifru;
1204
1205 if (cmd != SIOCDEVPLIP)
1206 return -EOPNOTSUPP;
1207
1208 switch(pc->pcmd) {
1209 case PLIP_GET_TIMEOUT:
1210 pc->trigger = nl->trigger;
1211 pc->nibble = nl->nibble;
1212 break;
1213 case PLIP_SET_TIMEOUT:
1214 if(!capable(CAP_NET_ADMIN))
1215 return -EPERM;
1216 nl->trigger = pc->trigger;
1217 nl->nibble = pc->nibble;
1218 break;
1219 default:
1220 return -EOPNOTSUPP;
1221 }
1222 return 0;
1223}
1224
1225static int parport[PLIP_MAX] = { [0 ... PLIP_MAX-1] = -1 };
1226static int timid;
1227
1228module_param_array(parport, int, NULL, 0);
1229module_param(timid, int, 0);
1230MODULE_PARM_DESC(parport, "List of parport device numbers to use by plip");
1231
1232static struct net_device *dev_plip[PLIP_MAX] = { NULL, };
1233
1234static inline int
1235plip_searchfor(int list[], int a)
1236{
1237 int i;
1238 for (i = 0; i < PLIP_MAX && list[i] != -1; i++) {
1239 if (list[i] == a) return 1;
1240 }
1241 return 0;
1242}
1243
1244/* plip_attach() is called (by the parport code) when a port is
1245 * available to use. */
1246static void plip_attach (struct parport *port)
1247{
1248 static int unit;
1249 struct net_device *dev;
1250 struct net_local *nl;
1251 char name[IFNAMSIZ];
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 nl->pardev = parport_register_device(port, dev->name, plip_preempt,
1277 plip_wakeup, plip_interrupt,
1278 0, dev);
1279
1280 if (!nl->pardev) {
1281 printk(KERN_ERR "%s: parport_register failed\n", name);
1282 goto err_free_dev;
1283 }
1284
1285 plip_init_netdev(dev);
1286
1287 if (register_netdev(dev)) {
1288 printk(KERN_ERR "%s: network register failed\n", name);
1289 goto err_parport_unregister;
1290 }
1291
1292 printk(KERN_INFO "%s", version);
1293 if (dev->irq != -1)
1294 printk(KERN_INFO "%s: Parallel port at %#3lx, "
1295 "using IRQ %d.\n",
1296 dev->name, dev->base_addr, dev->irq);
1297 else
1298 printk(KERN_INFO "%s: Parallel port at %#3lx, "
1299 "not using IRQ.\n",
1300 dev->name, dev->base_addr);
1301 dev_plip[unit++] = dev;
1302 }
1303 return;
1304
1305err_parport_unregister:
1306 parport_unregister_device(nl->pardev);
1307err_free_dev:
1308 free_netdev(dev);
1309}
1310
1311/* plip_detach() is called (by the parport code) when a port is
1312 * no longer available to use. */
1313static void plip_detach (struct parport *port)
1314{
1315 /* Nothing to do */
1316}
1317
1318static struct parport_driver plip_driver = {
1319 .name = "plip",
1320 .attach = plip_attach,
1321 .detach = plip_detach
1322};
1323
1324static void __exit plip_cleanup_module (void)
1325{
1326 struct net_device *dev;
1327 int i;
1328
1329 parport_unregister_driver (&plip_driver);
1330
1331 for (i=0; i < PLIP_MAX; i++) {
1332 if ((dev = dev_plip[i])) {
1333 struct net_local *nl = netdev_priv(dev);
1334 unregister_netdev(dev);
1335 if (nl->port_owner)
1336 parport_release(nl->pardev);
1337 parport_unregister_device(nl->pardev);
1338 free_netdev(dev);
1339 dev_plip[i] = NULL;
1340 }
1341 }
1342}
1343
1344#ifndef MODULE
1345
1346static int parport_ptr;
1347
1348static int __init plip_setup(char *str)
1349{
1350 int ints[4];
1351
1352 str = get_options(str, ARRAY_SIZE(ints), ints);
1353
1354 /* Ugh. */
1355 if (!strncmp(str, "parport", 7)) {
1356 int n = simple_strtoul(str+7, NULL, 10);
1357 if (parport_ptr < PLIP_MAX)
1358 parport[parport_ptr++] = n;
1359 else
1360 printk(KERN_INFO "plip: too many ports, %s ignored.\n",
1361 str);
1362 } else if (!strcmp(str, "timid")) {
1363 timid = 1;
1364 } else {
1365 if (ints[0] == 0 || ints[1] == 0) {
1366 /* disable driver on "plip=" or "plip=0" */
1367 parport[0] = -2;
1368 } else {
1369 printk(KERN_WARNING "warning: 'plip=0x%x' ignored\n",
1370 ints[1]);
1371 }
1372 }
1373 return 1;
1374}
1375
1376__setup("plip=", plip_setup);
1377
1378#endif /* !MODULE */
1379
1380static int __init plip_init (void)
1381{
1382 if (parport[0] == -2)
1383 return 0;
1384
1385 if (parport[0] != -1 && timid) {
1386 printk(KERN_WARNING "plip: warning, ignoring `timid' since specific ports given.\n");
1387 timid = 0;
1388 }
1389
1390 if (parport_register_driver (&plip_driver)) {
1391 printk (KERN_WARNING "plip: couldn't register driver\n");
1392 return 1;
1393 }
1394
1395 return 0;
1396}
1397
1398module_init(plip_init);
1399module_exit(plip_cleanup_module);
1400MODULE_LICENSE("GPL");