File: /usr/src/linux/drivers/char/n_r3964.c
1 /* r3964 linediscipline for linux
2 *
3 * -----------------------------------------------------------
4 * Copyright by
5 * Philips Automation Projects
6 * Kassel (Germany)
7 * http://www.pap-philips.de
8 * -----------------------------------------------------------
9 * This software may be used and distributed according to the terms of
10 * the GNU General Public License, incorporated herein by reference.
11 *
12 * Author:
13 * L. Haag
14 *
15 * $Log: n_r3964.c,v $
16 * Revision 1.8 2000/03/23 14:14:54 dwmw2
17 * Fix race in sleeping in r3964_read()
18 *
19 * Revision 1.7 1999/28/08 11:41:50 dwmw2
20 * Port to 2.3 kernel
21 *
22 * Revision 1.6 1998/09/30 00:40:40 dwmw2
23 * Fixed compilation on 2.0.x kernels
24 * Updated to newly registered tty-ldisc number 9
25 *
26 * Revision 1.5 1998/09/04 21:57:36 dwmw2
27 * Signal handling bug fixes, port to 2.1.x.
28 *
29 * Revision 1.4 1998/04/02 20:26:59 lhaag
30 * select, blocking, ...
31 *
32 * Revision 1.3 1998/02/12 18:58:43 root
33 * fixed some memory leaks
34 * calculation of checksum characters
35 *
36 * Revision 1.2 1998/02/07 13:03:34 root
37 * ioctl read_telegram
38 *
39 * Revision 1.1 1998/02/06 19:21:03 root
40 * Initial revision
41 *
42 *
43 */
44
45 #include <linux/module.h>
46 #include <linux/kernel.h>
47 #include <linux/sched.h>
48 #include <linux/types.h>
49 #include <linux/fcntl.h>
50 #include <linux/interrupt.h>
51 #include <linux/ptrace.h>
52 #include <linux/ioport.h>
53 #include <linux/in.h>
54 #include <linux/slab.h>
55 #include <linux/tty.h>
56 #include <linux/errno.h>
57 #include <linux/string.h> /* used in new tty drivers */
58 #include <linux/signal.h> /* used in new tty drivers */
59 #include <linux/ioctl.h>
60 #include <linux/n_r3964.h>
61 #include <linux/poll.h>
62 #include <linux/init.h>
63 #include <asm/uaccess.h>
64
65
66 //#define DEBUG_QUEUE
67
68 /* Log successful handshake and protocol operations */
69 //#define DEBUG_PROTO_S
70
71 /* Log handshake and protocol errors: */
72 //#define DEBUG_PROTO_E
73
74 /* Log Linediscipline operations (open, close, read, write...): */
75 //#define DEBUG_LDISC
76
77 /* Log module and memory operations (init, cleanup; kmalloc, kfree): */
78 //#define DEBUG_MODUL
79
80 /* Macro helpers for debug output: */
81 #define TRACE(format, args...) printk("r3964: " format "\n" , ## args);
82
83 #ifdef DEBUG_MODUL
84 #define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args);
85 #else
86 #define TRACE_M(fmt, arg...) /**/
87 #endif
88
89 #ifdef DEBUG_PROTO_S
90 #define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args);
91 #else
92 #define TRACE_PS(fmt, arg...) /**/
93 #endif
94
95 #ifdef DEBUG_PROTO_E
96 #define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args);
97 #else
98 #define TRACE_PE(fmt, arg...) /**/
99 #endif
100
101 #ifdef DEBUG_LDISC
102 #define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args);
103 #else
104 #define TRACE_L(fmt, arg...) /**/
105 #endif
106
107 #ifdef DEBUG_QUEUE
108 #define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args);
109 #else
110 #define TRACE_Q(fmt, arg...) /**/
111 #endif
112
113 static void on_timer_1(void*);
114 static void on_timer_2(void*);
115 static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
116 static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
117 static void put_char(struct r3964_info *pInfo, unsigned char ch);
118 static void trigger_transmit(struct r3964_info *pInfo);
119 static void retry_transmit(struct r3964_info *pInfo);
120 static void transmit_block(struct r3964_info *pInfo);
121 static void receive_char(struct r3964_info *pInfo, const unsigned char c);
122 static void receive_error(struct r3964_info *pInfo, const char flag);
123 static void on_timeout(struct r3964_info *pInfo);
124 static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg);
125 static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char *buf);
126 static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
127 int error_code, struct r3964_block_header *pBlock);
128 static struct r3964_message* remove_msg(struct r3964_info *pInfo,
129 struct r3964_client_info *pClient);
130 static void remove_client_block(struct r3964_info *pInfo,
131 struct r3964_client_info *pClient);
132
133 static int r3964_open(struct tty_struct *tty);
134 static void r3964_close(struct tty_struct *tty);
135 static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
136 unsigned char *buf, size_t nr);
137 static ssize_t r3964_write(struct tty_struct * tty, struct file * file,
138 const unsigned char * buf, size_t nr);
139 static int r3964_ioctl(struct tty_struct * tty, struct file * file,
140 unsigned int cmd, unsigned long arg);
141 static void r3964_set_termios(struct tty_struct *tty, struct termios * old);
142 static unsigned int r3964_poll(struct tty_struct * tty, struct file * file,
143 struct poll_table_struct *wait);
144 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
145 char *fp, int count);
146 static int r3964_receive_room(struct tty_struct *tty);
147
148 static struct tty_ldisc tty_ldisc_N_R3964 = {
149 TTY_LDISC_MAGIC, /* magic */
150 "R3964", /* name */
151 0, /* num */
152 0, /* flags */
153 r3964_open, /* open */
154 r3964_close, /* close */
155 0, /* flush_buffer */
156 0, /* chars_in_buffer */
157 r3964_read, /* read */
158 r3964_write, /* write */
159 r3964_ioctl, /* ioctl */
160 r3964_set_termios, /* set_termios */
161 r3964_poll, /* poll */
162 r3964_receive_buf, /* receive_buf */
163 r3964_receive_room, /* receive_room */
164 0 /* write_wakeup */
165 };
166
167
168
169 static void dump_block(const unsigned char *block, unsigned int length)
170 {
171 unsigned int i,j;
172 char linebuf[16*3+1];
173
174 for(i=0;i<length;i+=16)
175 {
176 for(j=0;(j<16) && (j+i<length);j++)
177 {
178 sprintf(linebuf+3*j,"%02x ",block[i+j]);
179 }
180 linebuf[3*j]='\0';
181 TRACE_PS("%s",linebuf);
182 }
183 }
184
185
186
187
188 /*************************************************************
189 * Driver initialisation
190 *************************************************************/
191
192
193 /*************************************************************
194 * Module support routines
195 *************************************************************/
196
197 static void __exit r3964_exit(void)
198 {
199 int status;
200
201 TRACE_M ("cleanup_module()");
202
203 status=tty_register_ldisc(N_R3964, NULL);
204
205 if(status!=0)
206 {
207 printk(KERN_ERR "r3964: error unregistering linediscipline: %d\n", status);
208 }
209 else
210 {
211 TRACE_L("linediscipline successfully unregistered");
212 }
213
214 }
215
216 static int __init r3964_init(void)
217 {
218 int status;
219
220 printk ("r3964: Philips r3964 Driver $Revision: 1.8 $\n");
221
222 /*
223 * Register the tty line discipline
224 */
225
226 status = tty_register_ldisc (N_R3964, &tty_ldisc_N_R3964);
227 if (status == 0)
228 {
229 TRACE_L("line discipline %d registered", N_R3964);
230 TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags,
231 tty_ldisc_N_R3964.num);
232 TRACE_L("open=%x", (int)tty_ldisc_N_R3964.open);
233 TRACE_L("tty_ldisc_N_R3964 = %x", (int)&tty_ldisc_N_R3964);
234 }
235 else
236 {
237 printk (KERN_ERR "r3964: error registering line discipline: %d\n", status);
238 }
239 return status;
240 }
241
242 module_init(r3964_init);
243 module_exit(r3964_exit);
244
245
246 /*************************************************************
247 * Protocol implementation routines
248 *************************************************************/
249
250 static void on_timer_1(void *arg)
251 {
252 struct r3964_info *pInfo = (struct r3964_info *)arg;
253
254 if(pInfo->count_down)
255 {
256 if(!--pInfo->count_down)
257 {
258 on_timeout(pInfo);
259 }
260 }
261 queue_task(&pInfo->bh_2, &tq_timer);
262 }
263
264 static void on_timer_2(void *arg)
265 {
266 struct r3964_info *pInfo = (struct r3964_info *)arg;
267
268 if(pInfo->count_down)
269 {
270 if(!--pInfo->count_down)
271 {
272 on_timeout(pInfo);
273 }
274 }
275 queue_task(&pInfo->bh_1, &tq_timer);
276 }
277
278 static void add_tx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader)
279 {
280 unsigned long flags;
281
282 save_flags(flags);
283 cli();
284
285 pHeader->next = NULL;
286
287 if(pInfo->tx_last == NULL)
288 {
289 pInfo->tx_first = pInfo->tx_last = pHeader;
290 }
291 else
292 {
293 pInfo->tx_last->next = pHeader;
294 pInfo->tx_last = pHeader;
295 }
296
297 restore_flags(flags);
298
299 TRACE_Q("add_tx_queue %x, length %d, tx_first = %x",
300 (int)pHeader, pHeader->length, (int)pInfo->tx_first );
301 }
302
303 static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
304 {
305 struct r3964_block_header *pHeader;
306 unsigned long flags;
307 #ifdef DEBUG_QUEUE
308 struct r3964_block_header *pDump;
309 #endif
310
311 pHeader = pInfo->tx_first;
312
313 if(pHeader==NULL)
314 return;
315
316 #ifdef DEBUG_QUEUE
317 printk("r3964: remove_from_tx_queue: %x, length %d - ",
318 (int)pHeader, (int)pHeader->length );
319 for(pDump=pHeader;pDump;pDump=pDump->next)
320 printk("%x ", (int)pDump);
321 printk("\n");
322 #endif
323
324
325 if(pHeader->owner)
326 {
327 if(error_code)
328 {
329 add_msg(pHeader->owner, R3964_MSG_ACK, 0,
330 error_code, NULL);
331 }
332 else
333 {
334 add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
335 error_code, NULL);
336 }
337 wake_up_interruptible (&pInfo->read_wait);
338 }
339
340 save_flags(flags);
341 cli();
342
343 pInfo->tx_first = pHeader->next;
344 if(pInfo->tx_first==NULL)
345 {
346 pInfo->tx_last = NULL;
347 }
348
349 restore_flags(flags);
350
351 kfree(pHeader);
352 TRACE_M("remove_from_tx_queue - kfree %x",(int)pHeader);
353
354 TRACE_Q("remove_from_tx_queue: tx_first = %x, tx_last = %x",
355 (int)pInfo->tx_first, (int)pInfo->tx_last );
356 }
357
358 static void add_rx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader)
359 {
360 unsigned long flags;
361
362 save_flags(flags);
363 cli();
364
365 pHeader->next = NULL;
366
367 if(pInfo->rx_last == NULL)
368 {
369 pInfo->rx_first = pInfo->rx_last = pHeader;
370 }
371 else
372 {
373 pInfo->rx_last->next = pHeader;
374 pInfo->rx_last = pHeader;
375 }
376 pInfo->blocks_in_rx_queue++;
377
378 restore_flags(flags);
379
380 TRACE_Q("add_rx_queue: %x, length = %d, rx_first = %x, count = %d",
381 (int)pHeader, pHeader->length,
382 (int)pInfo->rx_first, pInfo->blocks_in_rx_queue);
383 }
384
385 static void remove_from_rx_queue(struct r3964_info *pInfo,
386 struct r3964_block_header *pHeader)
387 {
388 unsigned long flags;
389 struct r3964_block_header *pFind;
390
391 if(pHeader==NULL)
392 return;
393
394 TRACE_Q("remove_from_rx_queue: rx_first = %x, rx_last = %x, count = %d",
395 (int)pInfo->rx_first, (int)pInfo->rx_last, pInfo->blocks_in_rx_queue );
396 TRACE_Q("remove_from_rx_queue: %x, length %d",
397 (int)pHeader, (int)pHeader->length );
398
399 save_flags(flags);
400 cli();
401
402 if(pInfo->rx_first == pHeader)
403 {
404 /* Remove the first block in the linked list: */
405 pInfo->rx_first = pHeader->next;
406
407 if(pInfo->rx_first==NULL)
408 {
409 pInfo->rx_last = NULL;
410 }
411 pInfo->blocks_in_rx_queue--;
412 }
413 else
414 {
415 /* Find block to remove: */
416 for(pFind=pInfo->rx_first; pFind; pFind=pFind->next)
417 {
418 if(pFind->next == pHeader)
419 {
420 /* Got it. */
421 pFind->next = pHeader->next;
422 pInfo->blocks_in_rx_queue--;
423 if(pFind->next==NULL)
424 {
425 /* Oh, removed the last one! */
426 pInfo->rx_last = pFind;
427 }
428 break;
429 }
430 }
431 }
432
433 restore_flags(flags);
434
435 kfree(pHeader);
436 TRACE_M("remove_from_rx_queue - kfree %x",(int)pHeader);
437
438 TRACE_Q("remove_from_rx_queue: rx_first = %x, rx_last = %x, count = %d",
439 (int)pInfo->rx_first, (int)pInfo->rx_last, pInfo->blocks_in_rx_queue );
440 }
441
442 static void put_char(struct r3964_info *pInfo, unsigned char ch)
443 {
444 struct tty_struct *tty = pInfo->tty;
445
446 if(tty==NULL)
447 return;
448
449 if(tty->driver.put_char)
450 {
451 tty->driver.put_char(tty, ch);
452 }
453 pInfo->bcc ^= ch;
454 }
455
456 static void flush(struct r3964_info *pInfo)
457 {
458 struct tty_struct *tty = pInfo->tty;
459
460 if(tty==NULL)
461 return;
462
463 if(tty->driver.flush_chars)
464 {
465 tty->driver.flush_chars(tty);
466 }
467 }
468
469 static void trigger_transmit(struct r3964_info *pInfo)
470 {
471 unsigned long flags;
472
473
474 save_flags(flags);
475 cli();
476
477 if((pInfo->state == R3964_IDLE) && (pInfo->tx_first!=NULL))
478 {
479 pInfo->state = R3964_TX_REQUEST;
480 pInfo->count_down = R3964_TO_QVZ;
481 pInfo->nRetry=0;
482 pInfo->flags &= ~R3964_ERROR;
483
484 restore_flags(flags);
485
486 TRACE_PS("trigger_transmit - sent STX");
487
488 put_char(pInfo, STX);
489 flush(pInfo);
490
491 pInfo->bcc = 0;
492 }
493 else
494 {
495 restore_flags(flags);
496 }
497 }
498
499 static void retry_transmit(struct r3964_info *pInfo)
500 {
501 if(pInfo->nRetry<R3964_MAX_RETRIES)
502 {
503 TRACE_PE("transmission failed. Retry #%d",
504 pInfo->nRetry);
505 pInfo->bcc = 0;
506 put_char(pInfo, STX);
507 flush(pInfo);
508 pInfo->state = R3964_TX_REQUEST;
509 pInfo->count_down = R3964_TO_QVZ;
510 pInfo->nRetry++;
511 }
512 else
513 {
514 TRACE_PE("transmission failed after %d retries",
515 R3964_MAX_RETRIES);
516
517 remove_from_tx_queue(pInfo, R3964_TX_FAIL);
518
519 put_char(pInfo, NAK);
520 flush(pInfo);
521 pInfo->state = R3964_IDLE;
522
523 trigger_transmit(pInfo);
524 }
525 }
526
527
528 static void transmit_block(struct r3964_info *pInfo)
529 {
530 struct tty_struct *tty = pInfo->tty;
531 struct r3964_block_header *pBlock = pInfo->tx_first;
532 int room=0;
533
534 if((tty==NULL) || (pBlock==NULL))
535 {
536 return;
537 }
538
539 if(tty->driver.write_room)
540 room=tty->driver.write_room(tty);
541
542 TRACE_PS("transmit_block %x, room %d, length %d",
543 (int)pBlock, room, pBlock->length);
544
545 while(pInfo->tx_position < pBlock->length)
546 {
547 if(room<2)
548 break;
549
550 if(pBlock->data[pInfo->tx_position]==DLE)
551 {
552 /* send additional DLE char: */
553 put_char(pInfo, DLE);
554 }
555 put_char(pInfo, pBlock->data[pInfo->tx_position++]);
556
557 room--;
558 }
559
560 if((pInfo->tx_position == pBlock->length) && (room>=3))
561 {
562 put_char(pInfo, DLE);
563 put_char(pInfo, ETX);
564 if(pInfo->flags & R3964_BCC)
565 {
566 put_char(pInfo, pInfo->bcc);
567 }
568 pInfo->state = R3964_WAIT_FOR_TX_ACK;
569 pInfo->count_down = R3964_TO_QVZ;
570 }
571 flush(pInfo);
572 }
573
574 static void on_receive_block(struct r3964_info *pInfo)
575 {
576 unsigned int length;
577 struct r3964_client_info *pClient;
578 struct r3964_block_header *pBlock;
579
580 length=pInfo->rx_position;
581
582 /* compare byte checksum characters: */
583 if(pInfo->flags & R3964_BCC)
584 {
585 if(pInfo->bcc!=pInfo->last_rx)
586 {
587 TRACE_PE("checksum error - got %x but expected %x",
588 pInfo->last_rx, pInfo->bcc);
589 pInfo->flags |= R3964_CHECKSUM;
590 }
591 }
592
593 /* check for errors (parity, overrun,...): */
594 if(pInfo->flags & R3964_ERROR)
595 {
596 TRACE_PE("on_receive_block - transmission failed error %x",
597 pInfo->flags & R3964_ERROR);
598
599 put_char(pInfo, NAK);
600 flush(pInfo);
601 if(pInfo->nRetry<R3964_MAX_RETRIES)
602 {
603 pInfo->state=R3964_WAIT_FOR_RX_REPEAT;
604 pInfo->count_down = R3964_TO_RX_PANIC;
605 pInfo->nRetry++;
606 }
607 else
608 {
609 TRACE_PE("on_receive_block - failed after max retries");
610 pInfo->state=R3964_IDLE;
611 }
612 return;
613 }
614
615
616 /* received block; submit DLE: */
617 put_char(pInfo, DLE);
618 flush(pInfo);
619 pInfo->count_down=0;
620 TRACE_PS(" rx success: got %d chars", length);
621
622 /* prepare struct r3964_block_header: */
623 pBlock = kmalloc(length+sizeof(struct r3964_block_header), GFP_KERNEL);
624 TRACE_M("on_receive_block - kmalloc %x",(int)pBlock);
625
626 if(pBlock==NULL)
627 return;
628
629 pBlock->length = length;
630 pBlock->data = ((unsigned char*)pBlock)+sizeof(struct r3964_block_header);
631 pBlock->locks = 0;
632 pBlock->next = NULL;
633 pBlock->owner = NULL;
634
635 memcpy(pBlock->data, pInfo->rx_buf, length);
636
637 /* queue block into rx_queue: */
638 add_rx_queue(pInfo, pBlock);
639
640 /* notify attached client processes: */
641 for(pClient=pInfo->firstClient; pClient; pClient=pClient->next)
642 {
643 if(pClient->sig_flags & R3964_SIG_DATA)
644 {
645 add_msg(pClient, R3964_MSG_DATA, length, R3964_OK, pBlock);
646 }
647 }
648 wake_up_interruptible (&pInfo->read_wait);
649
650 pInfo->state = R3964_IDLE;
651
652 trigger_transmit(pInfo);
653 }
654
655
656 static void receive_char(struct r3964_info *pInfo, const unsigned char c)
657 {
658 switch(pInfo->state)
659 {
660 case R3964_TX_REQUEST:
661 if(c==DLE)
662 {
663 TRACE_PS("TX_REQUEST - got DLE");
664
665 pInfo->state = R3964_TRANSMITTING;
666 pInfo->tx_position = 0;
667
668 transmit_block(pInfo);
669 }
670 else if(c==STX)
671 {
672 if(pInfo->nRetry==0)
673 {
674 TRACE_PE("TX_REQUEST - init conflict");
675 if(pInfo->priority == R3964_SLAVE)
676 {
677 goto start_receiving;
678 }
679 }
680 else
681 {
682 TRACE_PE("TX_REQUEST - secondary init conflict!?"
683 " Switching to SLAVE mode for next rx.");
684 goto start_receiving;
685 }
686 }
687 else
688 {
689 TRACE_PE("TX_REQUEST - char != DLE: %x", c);
690 retry_transmit(pInfo);
691 }
692 break;
693 case R3964_TRANSMITTING:
694 if(c==NAK)
695 {
696 TRACE_PE("TRANSMITTING - got NAK");
697 retry_transmit(pInfo);
698 }
699 else
700 {
701 TRACE_PE("TRANSMITTING - got illegal char");
702
703 pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
704 pInfo->count_down = R3964_TO_ZVZ;
705 }
706 break;
707 case R3964_WAIT_FOR_TX_ACK:
708 if(c==DLE)
709 {
710 TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
711 remove_from_tx_queue(pInfo, R3964_OK);
712
713 pInfo->state = R3964_IDLE;
714 trigger_transmit(pInfo);
715 }
716 else
717 {
718 retry_transmit(pInfo);
719 }
720 break;
721 case R3964_WAIT_FOR_RX_REPEAT:
722 /* FALLTROUGH */
723 case R3964_IDLE:
724 if(c==STX)
725 {
726 /* Prevent rx_queue from overflow: */
727 if(pInfo->blocks_in_rx_queue >= R3964_MAX_BLOCKS_IN_RX_QUEUE)
728 {
729 TRACE_PE("IDLE - got STX but no space in rx_queue!");
730 pInfo->state=R3964_WAIT_FOR_RX_BUF;
731 pInfo->count_down = R3964_TO_NO_BUF;
732 break;
733 }
734 start_receiving:
735 /* Ok, start receiving: */
736 TRACE_PS("IDLE - got STX");
737 pInfo->rx_position = 0;
738 pInfo->last_rx = 0;
739 pInfo->flags &= ~R3964_ERROR;
740 pInfo->state=R3964_RECEIVING;
741 pInfo->count_down = R3964_TO_ZVZ;
742 pInfo->nRetry = 0;
743 put_char(pInfo, DLE);
744 flush(pInfo);
745 pInfo->bcc = 0;
746 }
747 break;
748 case R3964_RECEIVING:
749 if(pInfo->rx_position < RX_BUF_SIZE)
750 {
751 pInfo->bcc ^= c;
752
753 if(c==DLE)
754 {
755 if(pInfo->last_rx==DLE)
756 {
757 pInfo->last_rx = 0;
758 goto char_to_buf;
759 }
760 pInfo->last_rx = DLE;
761 break;
762 }
763 else if((c==ETX) && (pInfo->last_rx==DLE))
764 {
765 if(pInfo->flags & R3964_BCC)
766 {
767 pInfo->state = R3964_WAIT_FOR_BCC;
768 pInfo->count_down = R3964_TO_ZVZ;
769 }
770 else
771 {
772 on_receive_block(pInfo);
773 }
774 }
775 else
776 {
777 pInfo->last_rx = c;
778 char_to_buf:
779 pInfo->rx_buf[pInfo->rx_position++] = c;
780 pInfo->count_down = R3964_TO_ZVZ;
781 }
782 }
783 /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
784 break;
785 case R3964_WAIT_FOR_BCC:
786 pInfo->last_rx = c;
787 on_receive_block(pInfo);
788 break;
789 }
790 }
791
792 static void receive_error(struct r3964_info *pInfo, const char flag)
793 {
794 switch (flag)
795 {
796 case TTY_NORMAL:
797 break;
798 case TTY_BREAK:
799 TRACE_PE("received break")
800 pInfo->flags |= R3964_BREAK;
801 break;
802 case TTY_PARITY:
803 TRACE_PE("parity error")
804 pInfo->flags |= R3964_PARITY;
805 break;
806 case TTY_FRAME:
807 TRACE_PE("frame error")
808 pInfo->flags |= R3964_FRAME;
809 break;
810 case TTY_OVERRUN:
811 TRACE_PE("frame overrun")
812 pInfo->flags |= R3964_OVERRUN;
813 break;
814 default:
815 TRACE_PE("receive_error - unknown flag %d", flag);
816 pInfo->flags |= R3964_UNKNOWN;
817 break;
818 }
819 }
820
821 static void on_timeout(struct r3964_info *pInfo)
822 {
823 switch(pInfo->state)
824 {
825 case R3964_TX_REQUEST:
826 TRACE_PE("TX_REQUEST - timeout");
827 retry_transmit(pInfo);
828 break;
829 case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
830 put_char(pInfo, NAK);
831 flush(pInfo);
832 retry_transmit(pInfo);
833 break;
834 case R3964_WAIT_FOR_TX_ACK:
835 TRACE_PE("WAIT_FOR_TX_ACK - timeout");
836 retry_transmit(pInfo);
837 break;
838 case R3964_WAIT_FOR_RX_BUF:
839 TRACE_PE("WAIT_FOR_RX_BUF - timeout");
840 put_char(pInfo, NAK);
841 flush(pInfo);
842 pInfo->state=R3964_IDLE;
843 break;
844 case R3964_RECEIVING:
845 TRACE_PE("RECEIVING - timeout after %d chars",
846 pInfo->rx_position);
847 put_char(pInfo, NAK);
848 flush(pInfo);
849 pInfo->state=R3964_IDLE;
850 break;
851 case R3964_WAIT_FOR_RX_REPEAT:
852 TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
853 pInfo->state=R3964_IDLE;
854 break;
855 case R3964_WAIT_FOR_BCC:
856 TRACE_PE("WAIT_FOR_BCC - timeout");
857 put_char(pInfo, NAK);
858 flush(pInfo);
859 pInfo->state=R3964_IDLE;
860 break;
861 }
862 }
863
864 static struct r3964_client_info *findClient(
865 struct r3964_info *pInfo, pid_t pid)
866 {
867 struct r3964_client_info *pClient;
868
869 for(pClient=pInfo->firstClient; pClient; pClient=pClient->next)
870 {
871 if(pClient->pid == pid)
872 {
873 return pClient;
874 }
875 }
876 return NULL;
877 }
878
879 static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg)
880 {
881 struct r3964_client_info *pClient;
882 struct r3964_client_info **ppClient;
883 struct r3964_message *pMsg;
884
885 if((arg & R3964_SIG_ALL)==0)
886 {
887 /* Remove client from client list */
888 for(ppClient=&pInfo->firstClient; *ppClient; ppClient=&(*ppClient)->next)
889 {
890 pClient = *ppClient;
891
892 if(pClient->pid == pid)
893 {
894 TRACE_PS("removing client %d from client list", pid);
895 *ppClient = pClient->next;
896 while(pClient->msg_count)
897 {
898 pMsg=remove_msg(pInfo, pClient);
899 if(pMsg)
900 {
901 kfree(pMsg);
902 TRACE_M("enable_signals - msg kfree %x",(int)pMsg);
903 }
904 }
905 kfree(pClient);
906 TRACE_M("enable_signals - kfree %x",(int)pClient);
907 return 0;
908 }
909 }
910 return -EINVAL;
911 }
912 else
913 {
914 pClient=findClient(pInfo, pid);
915 if(pClient)
916 {
917 /* update signal options */
918 pClient->sig_flags=arg;
919 }
920 else
921 {
922 /* add client to client list */
923 pClient=kmalloc(sizeof(struct r3964_client_info), GFP_KERNEL);
924 TRACE_M("enable_signals - kmalloc %x",(int)pClient);
925 if(pClient==NULL)
926 return -ENOMEM;
927
928 TRACE_PS("add client %d to client list", pid);
929 pClient->sig_flags=arg;
930 pClient->pid = pid;
931 pClient->next=pInfo->firstClient;
932 pClient->first_msg = NULL;
933 pClient->last_msg = NULL;
934 pClient->next_block_to_read = NULL;
935 pClient->msg_count = 0;
936 pInfo->firstClient=pClient;
937 }
938 }
939
940 return 0;
941 }
942
943 static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char *buf)
944 {
945 struct r3964_client_info *pClient;
946 struct r3964_block_header *block;
947
948 if(!buf)
949 {
950 return -EINVAL;
951 }
952
953 pClient=findClient(pInfo,pid);
954 if(pClient==NULL)
955 {
956 return -EINVAL;
957 }
958
959 block=pClient->next_block_to_read;
960 if(!block)
961 {
962 return 0;
963 }
964 else
965 {
966 if (copy_to_user (buf, block->data, block->length))
967 return -EFAULT;
968
969 remove_client_block(pInfo, pClient);
970 return block->length;
971 }
972
973 return -EINVAL;
974 }
975
976 static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
977 int error_code, struct r3964_block_header *pBlock)
978 {
979 struct r3964_message *pMsg;
980 unsigned long flags;
981
982 if(pClient->msg_count<R3964_MAX_MSG_COUNT-1)
983 {
984 queue_the_message:
985
986 pMsg = kmalloc(sizeof(struct r3964_message), GFP_KERNEL);
987 TRACE_M("add_msg - kmalloc %x",(int)pMsg);
988 if(pMsg==NULL) {
989 return;
990 }
991
992 save_flags(flags);
993 cli();
994
995 pMsg->msg_id = msg_id;
996 pMsg->arg = arg;
997 pMsg->error_code = error_code;
998 pMsg->block = pBlock;
999 pMsg->next = NULL;
1000
1001 if(pClient->last_msg==NULL)
1002 {
1003 pClient->first_msg=pClient->last_msg=pMsg;
1004 }
1005 else
1006 {
1007 pClient->last_msg->next = pMsg;
1008 pClient->last_msg=pMsg;
1009 }
1010
1011 pClient->msg_count++;
1012
1013 if(pBlock!=NULL)
1014 {
1015 pBlock->locks++;
1016 }
1017 restore_flags(flags);
1018 }
1019 else
1020 {
1021 if((pClient->last_msg->msg_id == R3964_MSG_ACK)
1022 && (pClient->last_msg->error_code==R3964_OVERFLOW))
1023 {
1024 pClient->last_msg->arg++;
1025 TRACE_PE("add_msg - inc prev OVERFLOW-msg");
1026 }
1027 else
1028 {
1029 msg_id = R3964_MSG_ACK;
1030 arg = 0;
1031 error_code = R3964_OVERFLOW;
1032 pBlock = NULL;
1033 TRACE_PE("add_msg - queue OVERFLOW-msg");
1034 goto queue_the_message;
1035 }
1036 }
1037 /* Send SIGIO signal to client process: */
1038 if(pClient->sig_flags & R3964_USE_SIGIO)
1039 {
1040 kill_proc(pClient->pid, SIGIO, 1);
1041 }
1042 }
1043
1044 static struct r3964_message *remove_msg(struct r3964_info *pInfo,
1045 struct r3964_client_info *pClient)
1046 {
1047 struct r3964_message *pMsg=NULL;
1048 unsigned long flags;
1049
1050 if(pClient->first_msg)
1051 {
1052 save_flags(flags);
1053 cli();
1054
1055 pMsg = pClient->first_msg;
1056 pClient->first_msg = pMsg->next;
1057 if(pClient->first_msg==NULL)
1058 {
1059 pClient->last_msg = NULL;
1060 }
1061
1062 pClient->msg_count--;
1063 if(pMsg->block)
1064 {
1065 remove_client_block(pInfo, pClient);
1066 pClient->next_block_to_read = pMsg->block;
1067 }
1068 restore_flags(flags);
1069 }
1070 return pMsg;
1071 }
1072
1073 static void remove_client_block(struct r3964_info *pInfo,
1074 struct r3964_client_info *pClient)
1075 {
1076 struct r3964_block_header *block;
1077
1078 TRACE_PS("remove_client_block PID %d", pClient->pid);
1079
1080 block=pClient->next_block_to_read;
1081 if(block)
1082 {
1083 block->locks--;
1084 if(block->locks==0)
1085 {
1086 remove_from_rx_queue(pInfo, block);
1087 }
1088 }
1089 pClient->next_block_to_read = NULL;
1090 }
1091
1092
1093 /*************************************************************
1094 * Line discipline routines
1095 *************************************************************/
1096
1097 static int r3964_open(struct tty_struct *tty)
1098 {
1099 struct r3964_info *pInfo;
1100
1101 MOD_INC_USE_COUNT;
1102
1103 TRACE_L("open");
1104 TRACE_L("tty=%x, PID=%d, disc_data=%x",
1105 (int)tty, current->pid, (int)tty->disc_data);
1106
1107 pInfo=kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
1108 TRACE_M("r3964_open - info kmalloc %x",(int)pInfo);
1109
1110 if(!pInfo)
1111 {
1112 printk(KERN_ERR "r3964: failed to alloc info structure\n");
1113 return -ENOMEM;
1114 }
1115
1116 pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
1117 TRACE_M("r3964_open - rx_buf kmalloc %x",(int)pInfo->rx_buf);
1118
1119 if(!pInfo->rx_buf)
1120 {
1121 printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
1122 kfree(pInfo);
1123 TRACE_M("r3964_open - info kfree %x",(int)pInfo);
1124 return -ENOMEM;
1125 }
1126
1127 pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
1128 TRACE_M("r3964_open - tx_buf kmalloc %x",(int)pInfo->tx_buf);
1129
1130 if(!pInfo->tx_buf)
1131 {
1132 printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
1133 kfree(pInfo->rx_buf);
1134 TRACE_M("r3964_open - rx_buf kfree %x",(int)pInfo->rx_buf);
1135 kfree(pInfo);
1136 TRACE_M("r3964_open - info kfree %x",(int)pInfo);
1137 return -ENOMEM;
1138 }
1139
1140 pInfo->tty = tty;
1141 init_waitqueue_head (&pInfo->read_wait);
1142 pInfo->priority = R3964_MASTER;
1143 pInfo->rx_first = pInfo->rx_last = NULL;
1144 pInfo->tx_first = pInfo->tx_last = NULL;
1145 pInfo->rx_position = 0;
1146 pInfo->tx_position = 0;
1147 pInfo->last_rx = 0;
1148 pInfo->blocks_in_rx_queue = 0;
1149 pInfo->firstClient=NULL;
1150 pInfo->state=R3964_IDLE;
1151 pInfo->flags = R3964_DEBUG;
1152 pInfo->count_down = 0;
1153 pInfo->nRetry = 0;
1154
1155 tty->disc_data = pInfo;
1156
1157 /*
1158 * Add 'on_timer' to timer task queue
1159 * (will be called from timer bh)
1160 */
1161 INIT_LIST_HEAD(&pInfo->bh_1.list);
1162 pInfo->bh_1.sync = 0;
1163 pInfo->bh_1.routine = &on_timer_1;
1164 pInfo->bh_1.data = pInfo;
1165
1166 INIT_LIST_HEAD(&pInfo->bh_2.list);
1167 pInfo->bh_2.sync = 0;
1168 pInfo->bh_2.routine = &on_timer_2;
1169 pInfo->bh_2.data = pInfo;
1170
1171 queue_task(&pInfo->bh_1, &tq_timer);
1172
1173 return 0;
1174 }
1175
1176 static void r3964_close(struct tty_struct *tty)
1177 {
1178 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1179 struct r3964_client_info *pClient, *pNext;
1180 struct r3964_message *pMsg;
1181 struct r3964_block_header *pHeader, *pNextHeader;
1182 unsigned long flags;
1183
1184 TRACE_L("close");
1185
1186 /*
1187 * Make sure that our task queue isn't activated. If it
1188 * is, take it out of the linked list.
1189 */
1190 spin_lock_irqsave(&tqueue_lock, flags);
1191 if (pInfo->bh_1.sync)
1192 list_del(&pInfo->bh_1.list);
1193 if (pInfo->bh_2.sync)
1194 list_del(&pInfo->bh_2.list);
1195 spin_unlock_irqrestore(&tqueue_lock, flags);
1196
1197 /* Remove client-structs and message queues: */
1198 pClient=pInfo->firstClient;
1199 while(pClient)
1200 {
1201 pNext=pClient->next;
1202 while(pClient->msg_count)
1203 {
1204 pMsg=remove_msg(pInfo, pClient);
1205 if(pMsg)
1206 {
1207 kfree(pMsg);
1208 TRACE_M("r3964_close - msg kfree %x",(int)pMsg);
1209 }
1210 }
1211 kfree(pClient);
1212 TRACE_M("r3964_close - client kfree %x",(int)pClient);
1213 pClient=pNext;
1214 }
1215 /* Remove jobs from tx_queue: */
1216 save_flags(flags);
1217 cli();
1218 pHeader=pInfo->tx_first;
1219 pInfo->tx_first=pInfo->tx_last=NULL;
1220 restore_flags(flags);
1221
1222 while(pHeader)
1223 {
1224 pNextHeader=pHeader->next;
1225 kfree(pHeader);
1226 pHeader=pNextHeader;
1227 }
1228
1229 /* Free buffers: */
1230 wake_up_interruptible(&pInfo->read_wait);
1231 kfree(pInfo->rx_buf);
1232 TRACE_M("r3964_close - rx_buf kfree %x",(int)pInfo->rx_buf);
1233 kfree(pInfo->tx_buf);
1234 TRACE_M("r3964_close - tx_buf kfree %x",(int)pInfo->tx_buf);
1235 kfree(pInfo);
1236 TRACE_M("r3964_close - info kfree %x",(int)pInfo);
1237
1238 MOD_DEC_USE_COUNT;
1239 }
1240
1241 static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
1242 unsigned char *buf, size_t nr)
1243 {
1244 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1245 struct r3964_client_info *pClient;
1246 struct r3964_message *pMsg;
1247 struct r3964_client_message theMsg;
1248 DECLARE_WAITQUEUE (wait, current);
1249
1250 int pid = current->pid;
1251 int count;
1252
1253 TRACE_L("read()");
1254
1255 pClient=findClient(pInfo, pid);
1256 if(pClient)
1257 {
1258 pMsg = remove_msg(pInfo, pClient);
1259 if(pMsg==NULL)
1260 {
1261 /* no messages available. */
1262 if (file->f_flags & O_NONBLOCK)
1263 {
1264 return -EAGAIN;
1265 }
1266 /* block until there is a message: */
1267 add_wait_queue(&pInfo->read_wait, &wait);
1268 repeat:
1269 current->state = TASK_INTERRUPTIBLE;
1270 pMsg = remove_msg(pInfo, pClient);
1271 if (!pMsg && !signal_pending(current))
1272 {
1273 schedule();
1274 goto repeat;
1275 }
1276 current->state = TASK_RUNNING;
1277 remove_wait_queue(&pInfo->read_wait, &wait);
1278 }
1279
1280 /* If we still haven't got a message, we must have been signalled */
1281
1282 if (!pMsg) return -EINTR;
1283
1284 /* deliver msg to client process: */
1285 theMsg.msg_id = pMsg->msg_id;
1286 theMsg.arg = pMsg->arg;
1287 theMsg.error_code = pMsg->error_code;
1288 count = sizeof(struct r3964_client_message);
1289
1290 kfree(pMsg);
1291 TRACE_M("r3964_read - msg kfree %x",(int)pMsg);
1292
1293 if (copy_to_user(buf,&theMsg, count))
1294 return -EFAULT;
1295
1296 TRACE_PS("read - return %d", count);
1297 return count;
1298 }
1299 return -EPERM;
1300 }
1301
1302 static ssize_t r3964_write(struct tty_struct * tty, struct file * file,
1303 const unsigned char *data, size_t count)
1304 {
1305 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1306 struct r3964_block_header *pHeader;
1307 struct r3964_client_info *pClient;
1308 unsigned char *new_data;
1309 int status;
1310 int pid;
1311
1312 TRACE_L("write request, %d characters", count);
1313 /*
1314 * Verify the pointers
1315 */
1316
1317 if(!pInfo)
1318 return -EIO;
1319
1320 status = verify_area (VERIFY_READ, data, count);
1321 if (status != 0)
1322 {
1323 return status;
1324 }
1325
1326 /*
1327 * Ensure that the caller does not wish to send too much.
1328 */
1329 if (count > R3964_MTU)
1330 {
1331 if (pInfo->flags & R3964_DEBUG)
1332 {
1333 TRACE_L (KERN_WARNING
1334 "r3964_write: truncating user packet "
1335 "from %u to mtu %d", count, R3964_MTU);
1336 }
1337 count = R3964_MTU;
1338 }
1339 /*
1340 * Allocate a buffer for the data and fetch it from the user space.
1341 */
1342 new_data = kmalloc (count+sizeof(struct r3964_block_header), GFP_KERNEL);
1343 TRACE_M("r3964_write - kmalloc %x",(int)new_data);
1344 if (new_data == NULL) {
1345 if (pInfo->flags & R3964_DEBUG)
1346 {
1347 printk (KERN_ERR
1348 "r3964_write: no memory\n");
1349 }
1350 return -ENOSPC;
1351 }
1352
1353 pHeader = (struct r3964_block_header *)new_data;
1354 pHeader->data = new_data + sizeof(struct r3964_block_header);
1355 pHeader->length = count;
1356 pHeader->locks = 0;
1357 pHeader->owner = NULL;
1358
1359 pid=current->pid;
1360
1361 pClient=findClient(pInfo, pid);
1362 if(pClient)
1363 {
1364 pHeader->owner = pClient;
1365 }
1366
1367 copy_from_user (pHeader->data, data, count); /* We already verified this */
1368
1369 if(pInfo->flags & R3964_DEBUG)
1370 {
1371 dump_block(pHeader->data, count);
1372 }
1373
1374 /*
1375 * Add buffer to transmit-queue:
1376 */
1377 add_tx_queue(pInfo, pHeader);
1378 trigger_transmit(pInfo);
1379
1380 return 0;
1381 }
1382
1383 static int r3964_ioctl(struct tty_struct * tty, struct file * file,
1384 unsigned int cmd, unsigned long arg)
1385 {
1386 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1387 if(pInfo==NULL)
1388 return -EINVAL;
1389 switch(cmd)
1390 {
1391 case R3964_ENABLE_SIGNALS:
1392 return enable_signals(pInfo, current->pid, arg);
1393 case R3964_SETPRIORITY:
1394 if(arg<R3964_MASTER || arg>R3964_SLAVE)
1395 return -EINVAL;
1396 pInfo->priority = arg & 0xff;
1397 return 0;
1398 case R3964_USE_BCC:
1399 if(arg)
1400 pInfo->flags |= R3964_BCC;
1401 else
1402 pInfo->flags &= ~R3964_BCC;
1403 return 0;
1404 case R3964_READ_TELEGRAM:
1405 return read_telegram(pInfo, current->pid, (unsigned char *)arg);
1406 default:
1407 return -ENOIOCTLCMD;
1408 }
1409 }
1410
1411 static void r3964_set_termios(struct tty_struct *tty, struct termios * old)
1412 {
1413 TRACE_L("set_termios");
1414 }
1415
1416 /* Called without the kernel lock held - fine */
1417 static unsigned int r3964_poll(struct tty_struct * tty, struct file * file,
1418 struct poll_table_struct *wait)
1419 {
1420 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1421 int pid=current->pid;
1422 struct r3964_client_info *pClient;
1423 struct r3964_message *pMsg=NULL;
1424 unsigned long flags;
1425 int result = POLLOUT;
1426
1427 TRACE_L("POLL");
1428
1429 pClient=findClient(pInfo,pid);
1430 if(pClient)
1431 {
1432 poll_wait(file, &pInfo->read_wait, wait);
1433 save_flags(flags);
1434 cli();
1435 pMsg=pClient->first_msg;
1436 restore_flags(flags);
1437 if(pMsg)
1438 result |= POLLIN | POLLRDNORM;
1439 }
1440 else
1441 {
1442 result = -EINVAL;
1443 }
1444 return result;
1445 }
1446
1447 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
1448 char *fp, int count)
1449 {
1450 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1451 const unsigned char *p;
1452 char *f, flags = 0;
1453 int i;
1454
1455 for (i=count, p = cp, f = fp; i; i--, p++) {
1456 if (f)
1457 flags = *f++;
1458 if(flags==TTY_NORMAL)
1459 {
1460 receive_char(pInfo, *p);
1461 }
1462 else
1463 {
1464 receive_error(pInfo, flags);
1465 }
1466
1467 }
1468 }
1469
1470 static int r3964_receive_room(struct tty_struct *tty)
1471 {
1472 TRACE_L("receive_room");
1473 return -1;
1474 }
1475
1476
1477 MODULE_LICENSE("GPL");
1478
1479 EXPORT_NO_SYMBOLS;
1480