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[PATCH] TTY layer buffering revamp
[deliverable/linux.git] / drivers / char / n_r3964.c
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1da177e4
LT		 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 1.10 2001/03/18 13:02:24 dwmw2
17 * Fix timer usage, use spinlocks properly.
18 *
19 * Revision 1.9 2001/03/18 12:52:14 dwmw2
20 * Merge changes in 2.4.2
21 *
22 * Revision 1.8 2000/03/23 14:14:54 dwmw2
23 * Fix race in sleeping in r3964_read()
24 *
25 * Revision 1.7 1999/28/08 11:41:50 dwmw2
26 * Port to 2.3 kernel
27 *
28 * Revision 1.6 1998/09/30 00:40:40 dwmw2
29 * Fixed compilation on 2.0.x kernels
30 * Updated to newly registered tty-ldisc number 9
31 *
32 * Revision 1.5 1998/09/04 21:57:36 dwmw2
33 * Signal handling bug fixes, port to 2.1.x.
34 *
35 * Revision 1.4 1998/04/02 20:26:59 lhaag
36 * select, blocking, ...
37 *
38 * Revision 1.3 1998/02/12 18:58:43 root
39 * fixed some memory leaks
40 * calculation of checksum characters
41 *
42 * Revision 1.2 1998/02/07 13:03:34 root
43 * ioctl read_telegram
44 *
45 * Revision 1.1 1998/02/06 19:21:03 root
46 * Initial revision
47 *
48 *
49 */
50
51#include <linux/module.h>
52#include <linux/kernel.h>
53#include <linux/sched.h>
54#include <linux/types.h>
55#include <linux/fcntl.h>
56#include <linux/interrupt.h>
57#include <linux/ptrace.h>
58#include <linux/ioport.h>
59#include <linux/in.h>
60#include <linux/slab.h>
61#include <linux/tty.h>
62#include <linux/errno.h>
63#include <linux/string.h> /* used in new tty drivers */
64#include <linux/signal.h> /* used in new tty drivers */
65#include <linux/ioctl.h>
66#include <linux/n_r3964.h>
67#include <linux/poll.h>
68#include <linux/init.h>
69#include <asm/uaccess.h>
70
71
72//#define DEBUG_QUEUE
73
74/* Log successful handshake and protocol operations */
75//#define DEBUG_PROTO_S
76
77/* Log handshake and protocol errors: */
78//#define DEBUG_PROTO_E
79
80/* Log Linediscipline operations (open, close, read, write...): */
81//#define DEBUG_LDISC
82
83/* Log module and memory operations (init, cleanup; kmalloc, kfree): */
84//#define DEBUG_MODUL
85
86/* Macro helpers for debug output: */
87#define TRACE(format, args...) printk("r3964: " format "\n" , ## args);
88
89#ifdef DEBUG_MODUL
90#define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args);
91#else
92#define TRACE_M(fmt, arg...) /**/
93#endif
94
95#ifdef DEBUG_PROTO_S
96#define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args);
97#else
98#define TRACE_PS(fmt, arg...) /**/
99#endif
100
101#ifdef DEBUG_PROTO_E
102#define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args);
103#else
104#define TRACE_PE(fmt, arg...) /**/
105#endif
106
107#ifdef DEBUG_LDISC
108#define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args);
109#else
110#define TRACE_L(fmt, arg...) /**/
111#endif
112
113#ifdef DEBUG_QUEUE
114#define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args);
115#else
116#define TRACE_Q(fmt, arg...) /**/
117#endif
118
119static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
120static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
121static void put_char(struct r3964_info *pInfo, unsigned char ch);
122static void trigger_transmit(struct r3964_info *pInfo);
123static void retry_transmit(struct r3964_info *pInfo);
124static void transmit_block(struct r3964_info *pInfo);
125static void receive_char(struct r3964_info *pInfo, const unsigned char c);
126static void receive_error(struct r3964_info *pInfo, const char flag);
127static void on_timeout(unsigned long priv);
128static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg);
129static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char __user *buf);
130static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
131 int error_code, struct r3964_block_header *pBlock);
132static struct r3964_message* remove_msg(struct r3964_info *pInfo,
133 struct r3964_client_info *pClient);
134static void remove_client_block(struct r3964_info *pInfo,
135 struct r3964_client_info *pClient);
136
137static int r3964_open(struct tty_struct *tty);
138static void r3964_close(struct tty_struct *tty);
139static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
140 unsigned char __user *buf, size_t nr);
141static ssize_t r3964_write(struct tty_struct * tty, struct file * file,
142 const unsigned char * buf, size_t nr);
143static int r3964_ioctl(struct tty_struct * tty, struct file * file,
144 unsigned int cmd, unsigned long arg);
145static void r3964_set_termios(struct tty_struct *tty, struct termios * old);
146static unsigned int r3964_poll(struct tty_struct * tty, struct file * file,
147 struct poll_table_struct *wait);
148static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
149 char *fp, int count);
1da177e4
LT		 150
151static struct tty_ldisc tty_ldisc_N_R3964 = {
152 .owner = THIS_MODULE,
153 .magic = TTY_LDISC_MAGIC,
154 .name = "R3964",
155 .open = r3964_open,
156 .close = r3964_close,
157 .read = r3964_read,
158 .write = r3964_write,
159 .ioctl = r3964_ioctl,
160 .set_termios = r3964_set_termios,
161 .poll = r3964_poll,
162 .receive_buf = r3964_receive_buf,
1da177e4
LT		 163};
164
165
166
167static void dump_block(const unsigned char *block, unsigned int length)
168{
169 unsigned int i,j;
170 char linebuf[16*3+1];
171
172 for(i=0;i<length;i+=16)
173 {
174 for(j=0;(j<16) && (j+i<length);j++)
175 {
176 sprintf(linebuf+3*j,"%02x ",block[i+j]);
177 }
178 linebuf[3*j]='\0';
179 TRACE_PS("%s",linebuf);
180 }
181}
182
183
184
185
186/*************************************************************
187 * Driver initialisation
188 *************************************************************/
189
190
191/*************************************************************
192 * Module support routines
193 *************************************************************/
194
195static void __exit r3964_exit(void)
196{
197 int status;
198
199 TRACE_M ("cleanup_module()");
200
64ccd715 201 status=tty_unregister_ldisc(N_R3964);
1da177e4
LT		 202
203 if(status!=0)
204 {
205 printk(KERN_ERR "r3964: error unregistering linediscipline: %d\n", status);
206 }
207 else
208 {
209 TRACE_L("linediscipline successfully unregistered");
210 }
211
212}
213
214static int __init r3964_init(void)
215{
216 int status;
217
218 printk ("r3964: Philips r3964 Driver $Revision: 1.10 $\n");
219
220 /*
221 * Register the tty line discipline
222 */
223
224 status = tty_register_ldisc (N_R3964, &tty_ldisc_N_R3964);
225 if (status == 0)
226 {
227 TRACE_L("line discipline %d registered", N_R3964);
228 TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags,
229 tty_ldisc_N_R3964.num);
87e0f3db
AD		 230 TRACE_L("open=%p", tty_ldisc_N_R3964.open);
231 TRACE_L("tty_ldisc_N_R3964 = %p", &tty_ldisc_N_R3964);
1da177e4
LT		 232 }
233 else
234 {
235 printk (KERN_ERR "r3964: error registering line discipline: %d\n", status);
236 }
237 return status;
238}
239
240module_init(r3964_init);
241module_exit(r3964_exit);
242
243
244/*************************************************************
245 * Protocol implementation routines
246 *************************************************************/
247
248static void add_tx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader)
249{
250 unsigned long flags;
251
252 spin_lock_irqsave(&pInfo->lock, flags);
253
254 pHeader->next = NULL;
255
256 if(pInfo->tx_last == NULL)
257 {
258 pInfo->tx_first = pInfo->tx_last = pHeader;
259 }
260 else
261 {
262 pInfo->tx_last->next = pHeader;
263 pInfo->tx_last = pHeader;
264 }
265
266 spin_unlock_irqrestore(&pInfo->lock, flags);
267
87e0f3db
AD		 268 TRACE_Q("add_tx_queue %p, length %d, tx_first = %p",
269 pHeader, pHeader->length, pInfo->tx_first );
1da177e4
LT		 270}
271
272static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
273{
274 struct r3964_block_header *pHeader;
275 unsigned long flags;
276#ifdef DEBUG_QUEUE
277 struct r3964_block_header *pDump;
278#endif
279
280 pHeader = pInfo->tx_first;
281
282 if(pHeader==NULL)
283 return;
284
285#ifdef DEBUG_QUEUE
87e0f3db
AD		 286 printk("r3964: remove_from_tx_queue: %p, length %u - ",
287 pHeader, pHeader->length );
1da177e4 288 for(pDump=pHeader;pDump;pDump=pDump->next)
87e0f3db 289 printk("%p ", pDump);
1da177e4
LT		 290 printk("\n");
291#endif
292
293
294 if(pHeader->owner)
295 {
296 if(error_code)
297 {
298 add_msg(pHeader->owner, R3964_MSG_ACK, 0,
299 error_code, NULL);
300 }
301 else
302 {
303 add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
304 error_code, NULL);
305 }
306 wake_up_interruptible (&pInfo->read_wait);
307 }
308
309 spin_lock_irqsave(&pInfo->lock, flags);
310
311 pInfo->tx_first = pHeader->next;
312 if(pInfo->tx_first==NULL)
313 {
314 pInfo->tx_last = NULL;
315 }
316
317 spin_unlock_irqrestore(&pInfo->lock, flags);
318
319 kfree(pHeader);
87e0f3db 320 TRACE_M("remove_from_tx_queue - kfree %p",pHeader);
1da177e4 321
87e0f3db
AD		 322 TRACE_Q("remove_from_tx_queue: tx_first = %p, tx_last = %p",
323 pInfo->tx_first, pInfo->tx_last );
1da177e4
LT		 324}
325
326static void add_rx_queue(struct r3964_info *pInfo, struct r3964_block_header *pHeader)
327{
328 unsigned long flags;
329
330 spin_lock_irqsave(&pInfo->lock, flags);
331
332 pHeader->next = NULL;
333
334 if(pInfo->rx_last == NULL)
335 {
336 pInfo->rx_first = pInfo->rx_last = pHeader;
337 }
338 else
339 {
340 pInfo->rx_last->next = pHeader;
341 pInfo->rx_last = pHeader;
342 }
343 pInfo->blocks_in_rx_queue++;
344
345 spin_unlock_irqrestore(&pInfo->lock, flags);
346
87e0f3db
AD		 347 TRACE_Q("add_rx_queue: %p, length = %d, rx_first = %p, count = %d",
348 pHeader, pHeader->length,
349 pInfo->rx_first, pInfo->blocks_in_rx_queue);
1da177e4
LT		 350}
351
352static void remove_from_rx_queue(struct r3964_info *pInfo,
353 struct r3964_block_header *pHeader)
354{
355 unsigned long flags;
356 struct r3964_block_header *pFind;
357
358 if(pHeader==NULL)
359 return;
360
87e0f3db
AD		 361 TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
362 pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue );
363 TRACE_Q("remove_from_rx_queue: %p, length %u",
364 pHeader, pHeader->length );
1da177e4
LT		 365
366 spin_lock_irqsave(&pInfo->lock, flags);
367
368 if(pInfo->rx_first == pHeader)
369 {
370 /* Remove the first block in the linked list: */
371 pInfo->rx_first = pHeader->next;
372
373 if(pInfo->rx_first==NULL)
374 {
375 pInfo->rx_last = NULL;
376 }
377 pInfo->blocks_in_rx_queue--;
378 }
379 else
380 {
381 /* Find block to remove: */
382 for(pFind=pInfo->rx_first; pFind; pFind=pFind->next)
383 {
384 if(pFind->next == pHeader)
385 {
386 /* Got it. */
387 pFind->next = pHeader->next;
388 pInfo->blocks_in_rx_queue--;
389 if(pFind->next==NULL)
390 {
391 /* Oh, removed the last one! */
392 pInfo->rx_last = pFind;
393 }
394 break;
395 }
396 }
397 }
398
399 spin_unlock_irqrestore(&pInfo->lock, flags);
400
401 kfree(pHeader);
87e0f3db 402 TRACE_M("remove_from_rx_queue - kfree %p",pHeader);
1da177e4 403
87e0f3db
AD		 404 TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
405 pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue );
1da177e4
LT		 406}
407
408static void put_char(struct r3964_info *pInfo, unsigned char ch)
409{
410 struct tty_struct *tty = pInfo->tty;
411
412 if(tty==NULL)
413 return;
414
415 if(tty->driver->put_char)
416 {
417 tty->driver->put_char(tty, ch);
418 }
419 pInfo->bcc ^= ch;
420}
421
422static void flush(struct r3964_info *pInfo)
423{
424 struct tty_struct *tty = pInfo->tty;
425
426 if(tty==NULL)
427 return;
428
429 if(tty->driver->flush_chars)
430 {
431 tty->driver->flush_chars(tty);
432 }
433}
434
435static void trigger_transmit(struct r3964_info *pInfo)
436{
437 unsigned long flags;
438
439
440 spin_lock_irqsave(&pInfo->lock, flags);
441
442 if((pInfo->state == R3964_IDLE) && (pInfo->tx_first!=NULL))
443 {
444 pInfo->state = R3964_TX_REQUEST;
445 pInfo->nRetry=0;
446 pInfo->flags &= ~R3964_ERROR;
447 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
448
449 spin_unlock_irqrestore(&pInfo->lock, flags);
450
451 TRACE_PS("trigger_transmit - sent STX");
452
453 put_char(pInfo, STX);
454 flush(pInfo);
455
456 pInfo->bcc = 0;
457 }
458 else
459 {
460 spin_unlock_irqrestore(&pInfo->lock, flags);
461 }
462}
463
464static void retry_transmit(struct r3964_info *pInfo)
465{
466 if(pInfo->nRetry<R3964_MAX_RETRIES)
467 {
468 TRACE_PE("transmission failed. Retry #%d",
469 pInfo->nRetry);
470 pInfo->bcc = 0;
471 put_char(pInfo, STX);
472 flush(pInfo);
473 pInfo->state = R3964_TX_REQUEST;
474 pInfo->nRetry++;
475 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
476 }
477 else
478 {
479 TRACE_PE("transmission failed after %d retries",
480 R3964_MAX_RETRIES);
481
482 remove_from_tx_queue(pInfo, R3964_TX_FAIL);
483
484 put_char(pInfo, NAK);
485 flush(pInfo);
486 pInfo->state = R3964_IDLE;
487
488 trigger_transmit(pInfo);
489 }
490}
491
492
493static void transmit_block(struct r3964_info *pInfo)
494{
495 struct tty_struct *tty = pInfo->tty;
496 struct r3964_block_header *pBlock = pInfo->tx_first;
497 int room=0;
498
499 if((tty==NULL) || (pBlock==NULL))
500 {
501 return;
502 }
503
504 if(tty->driver->write_room)
505 room=tty->driver->write_room(tty);
506
87e0f3db
AD		 507 TRACE_PS("transmit_block %p, room %d, length %d",
508 pBlock, room, pBlock->length);
1da177e4
LT		 509
510 while(pInfo->tx_position < pBlock->length)
511 {
512 if(room<2)
513 break;
514
515 if(pBlock->data[pInfo->tx_position]==DLE)
516 {
517 /* send additional DLE char: */
518 put_char(pInfo, DLE);
519 }
520 put_char(pInfo, pBlock->data[pInfo->tx_position++]);
521
522 room--;
523 }
524
525 if((pInfo->tx_position == pBlock->length) && (room>=3))
526 {
527 put_char(pInfo, DLE);
528 put_char(pInfo, ETX);
529 if(pInfo->flags & R3964_BCC)
530 {
531 put_char(pInfo, pInfo->bcc);
532 }
533 pInfo->state = R3964_WAIT_FOR_TX_ACK;
534 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
535 }
536 flush(pInfo);
537}
538
539static void on_receive_block(struct r3964_info *pInfo)
540{
541 unsigned int length;
542 struct r3964_client_info *pClient;
543 struct r3964_block_header *pBlock;
544
545 length=pInfo->rx_position;
546
547 /* compare byte checksum characters: */
548 if(pInfo->flags & R3964_BCC)
549 {
550 if(pInfo->bcc!=pInfo->last_rx)
551 {
552 TRACE_PE("checksum error - got %x but expected %x",
553 pInfo->last_rx, pInfo->bcc);
554 pInfo->flags |= R3964_CHECKSUM;
555 }
556 }
557
558 /* check for errors (parity, overrun,...): */
559 if(pInfo->flags & R3964_ERROR)
560 {
561 TRACE_PE("on_receive_block - transmission failed error %x",
562 pInfo->flags & R3964_ERROR);
563
564 put_char(pInfo, NAK);
565 flush(pInfo);
566 if(pInfo->nRetry<R3964_MAX_RETRIES)
567 {
568 pInfo->state=R3964_WAIT_FOR_RX_REPEAT;
569 pInfo->nRetry++;
570 mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
571 }
572 else
573 {
574 TRACE_PE("on_receive_block - failed after max retries");
575 pInfo->state=R3964_IDLE;
576 }
577 return;
578 }
579
580
581 /* received block; submit DLE: */
582 put_char(pInfo, DLE);
583 flush(pInfo);
584 del_timer_sync(&pInfo->tmr);
585 TRACE_PS(" rx success: got %d chars", length);
586
587 /* prepare struct r3964_block_header: */
588 pBlock = kmalloc(length+sizeof(struct r3964_block_header), GFP_KERNEL);
87e0f3db 589 TRACE_M("on_receive_block - kmalloc %p",pBlock);
1da177e4
LT		 590
591 if(pBlock==NULL)
592 return;
593
594 pBlock->length = length;
595 pBlock->data = ((unsigned char*)pBlock)+sizeof(struct r3964_block_header);
596 pBlock->locks = 0;
597 pBlock->next = NULL;
598 pBlock->owner = NULL;
599
600 memcpy(pBlock->data, pInfo->rx_buf, length);
601
602 /* queue block into rx_queue: */
603 add_rx_queue(pInfo, pBlock);
604
605 /* notify attached client processes: */
606 for(pClient=pInfo->firstClient; pClient; pClient=pClient->next)
607 {
608 if(pClient->sig_flags & R3964_SIG_DATA)
609 {
610 add_msg(pClient, R3964_MSG_DATA, length, R3964_OK, pBlock);
611 }
612 }
613 wake_up_interruptible (&pInfo->read_wait);
614
615 pInfo->state = R3964_IDLE;
616
617 trigger_transmit(pInfo);
618}
619
620
621static void receive_char(struct r3964_info *pInfo, const unsigned char c)
622{
623 switch(pInfo->state)
624 {
625 case R3964_TX_REQUEST:
626 if(c==DLE)
627 {
628 TRACE_PS("TX_REQUEST - got DLE");
629
630 pInfo->state = R3964_TRANSMITTING;
631 pInfo->tx_position = 0;
632
633 transmit_block(pInfo);
634 }
635 else if(c==STX)
636 {
637 if(pInfo->nRetry==0)
638 {
639 TRACE_PE("TX_REQUEST - init conflict");
640 if(pInfo->priority == R3964_SLAVE)
641 {
642 goto start_receiving;
643 }
644 }
645 else
646 {
647 TRACE_PE("TX_REQUEST - secondary init conflict!?"
648 " Switching to SLAVE mode for next rx.");
649 goto start_receiving;
650 }
651 }
652 else
653 {
654 TRACE_PE("TX_REQUEST - char != DLE: %x", c);
655 retry_transmit(pInfo);
656 }
657 break;
658 case R3964_TRANSMITTING:
659 if(c==NAK)
660 {
661 TRACE_PE("TRANSMITTING - got NAK");
662 retry_transmit(pInfo);
663 }
664 else
665 {
666 TRACE_PE("TRANSMITTING - got invalid char");
667
668 pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
669 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
670 }
671 break;
672 case R3964_WAIT_FOR_TX_ACK:
673 if(c==DLE)
674 {
675 TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
676 remove_from_tx_queue(pInfo, R3964_OK);
677
678 pInfo->state = R3964_IDLE;
679 trigger_transmit(pInfo);
680 }
681 else
682 {
683 retry_transmit(pInfo);
684 }
685 break;
686 case R3964_WAIT_FOR_RX_REPEAT:
687 /* FALLTROUGH */
688 case R3964_IDLE:
689 if(c==STX)
690 {
691 /* Prevent rx_queue from overflow: */
692 if(pInfo->blocks_in_rx_queue >= R3964_MAX_BLOCKS_IN_RX_QUEUE)
693 {
694 TRACE_PE("IDLE - got STX but no space in rx_queue!");
695 pInfo->state=R3964_WAIT_FOR_RX_BUF;
9ac0b9c1 696 mod_timer(&pInfo->tmr, jiffies + R3964_TO_NO_BUF);
1da177e4
LT		 697 break;
698 }
699start_receiving:
700 /* Ok, start receiving: */
701 TRACE_PS("IDLE - got STX");
702 pInfo->rx_position = 0;
703 pInfo->last_rx = 0;
704 pInfo->flags &= ~R3964_ERROR;
705 pInfo->state=R3964_RECEIVING;
9ac0b9c1 706 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
1da177e4
LT		 707 pInfo->nRetry = 0;
708 put_char(pInfo, DLE);
709 flush(pInfo);
710 pInfo->bcc = 0;
711 }
712 break;
713 case R3964_RECEIVING:
714 if(pInfo->rx_position < RX_BUF_SIZE)
715 {
716 pInfo->bcc ^= c;
717
718 if(c==DLE)
719 {
720 if(pInfo->last_rx==DLE)
721 {
722 pInfo->last_rx = 0;
723 goto char_to_buf;
724 }
725 pInfo->last_rx = DLE;
726 break;
727 }
728 else if((c==ETX) && (pInfo->last_rx==DLE))
729 {
730 if(pInfo->flags & R3964_BCC)
731 {
732 pInfo->state = R3964_WAIT_FOR_BCC;
9ac0b9c1 733 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
1da177e4
LT		 734 }
735 else
736 {
737 on_receive_block(pInfo);
738 }
739 }
740 else
741 {
742 pInfo->last_rx = c;
743char_to_buf:
744 pInfo->rx_buf[pInfo->rx_position++] = c;
9ac0b9c1 745 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
1da177e4
LT		 746 }
747 }
748 /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
749 break;
750 case R3964_WAIT_FOR_BCC:
751 pInfo->last_rx = c;
752 on_receive_block(pInfo);
753 break;
754 }
755}
756
757static void receive_error(struct r3964_info *pInfo, const char flag)
758{
759 switch (flag)
760 {
761 case TTY_NORMAL:
762 break;
763 case TTY_BREAK:
764 TRACE_PE("received break")
765 pInfo->flags |= R3964_BREAK;
766 break;
767 case TTY_PARITY:
768 TRACE_PE("parity error")
769 pInfo->flags |= R3964_PARITY;
770 break;
771 case TTY_FRAME:
772 TRACE_PE("frame error")
773 pInfo->flags |= R3964_FRAME;
774 break;
775 case TTY_OVERRUN:
776 TRACE_PE("frame overrun")
777 pInfo->flags |= R3964_OVERRUN;
778 break;
779 default:
780 TRACE_PE("receive_error - unknown flag %d", flag);
781 pInfo->flags |= R3964_UNKNOWN;
782 break;
783 }
784}
785
786static void on_timeout(unsigned long priv)
787{
788 struct r3964_info *pInfo = (void *)priv;
789
790 switch(pInfo->state)
791 {
792 case R3964_TX_REQUEST:
793 TRACE_PE("TX_REQUEST - timeout");
794 retry_transmit(pInfo);
795 break;
796 case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
797 put_char(pInfo, NAK);
798 flush(pInfo);
799 retry_transmit(pInfo);
800 break;
801 case R3964_WAIT_FOR_TX_ACK:
802 TRACE_PE("WAIT_FOR_TX_ACK - timeout");
803 retry_transmit(pInfo);
804 break;
805 case R3964_WAIT_FOR_RX_BUF:
806 TRACE_PE("WAIT_FOR_RX_BUF - timeout");
807 put_char(pInfo, NAK);
808 flush(pInfo);
809 pInfo->state=R3964_IDLE;
810 break;
811 case R3964_RECEIVING:
812 TRACE_PE("RECEIVING - timeout after %d chars",
813 pInfo->rx_position);
814 put_char(pInfo, NAK);
815 flush(pInfo);
816 pInfo->state=R3964_IDLE;
817 break;
818 case R3964_WAIT_FOR_RX_REPEAT:
819 TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
820 pInfo->state=R3964_IDLE;
821 break;
822 case R3964_WAIT_FOR_BCC:
823 TRACE_PE("WAIT_FOR_BCC - timeout");
824 put_char(pInfo, NAK);
825 flush(pInfo);
826 pInfo->state=R3964_IDLE;
827 break;
828 }
829}
830
831static struct r3964_client_info *findClient(
832 struct r3964_info *pInfo, pid_t pid)
833{
834 struct r3964_client_info *pClient;
835
836 for(pClient=pInfo->firstClient; pClient; pClient=pClient->next)
837 {
838 if(pClient->pid == pid)
839 {
840 return pClient;
841 }
842 }
843 return NULL;
844}
845
846static int enable_signals(struct r3964_info *pInfo, pid_t pid, int arg)
847{
848 struct r3964_client_info *pClient;
849 struct r3964_client_info **ppClient;
850 struct r3964_message *pMsg;
851
852 if((arg & R3964_SIG_ALL)==0)
853 {
854 /* Remove client from client list */
855 for(ppClient=&pInfo->firstClient; *ppClient; ppClient=&(*ppClient)->next)
856 {
857 pClient = *ppClient;
858
859 if(pClient->pid == pid)
860 {
861 TRACE_PS("removing client %d from client list", pid);
862 *ppClient = pClient->next;
863 while(pClient->msg_count)
864 {
865 pMsg=remove_msg(pInfo, pClient);
866 if(pMsg)
867 {
868 kfree(pMsg);
87e0f3db 869 TRACE_M("enable_signals - msg kfree %p",pMsg);
1da177e4
LT		 870 }
871 }
872 kfree(pClient);
87e0f3db 873 TRACE_M("enable_signals - kfree %p",pClient);
1da177e4
LT		 874 return 0;
875 }
876 }
877 return -EINVAL;
878 }
879 else
880 {
881 pClient=findClient(pInfo, pid);
882 if(pClient)
883 {
884 /* update signal options */
885 pClient->sig_flags=arg;
886 }
887 else
888 {
889 /* add client to client list */
890 pClient=kmalloc(sizeof(struct r3964_client_info), GFP_KERNEL);
87e0f3db 891 TRACE_M("enable_signals - kmalloc %p",pClient);
1da177e4
LT		 892 if(pClient==NULL)
893 return -ENOMEM;
894
895 TRACE_PS("add client %d to client list", pid);
896 spin_lock_init(&pClient->lock);
897 pClient->sig_flags=arg;
898 pClient->pid = pid;
899 pClient->next=pInfo->firstClient;
900 pClient->first_msg = NULL;
901 pClient->last_msg = NULL;
902 pClient->next_block_to_read = NULL;
903 pClient->msg_count = 0;
904 pInfo->firstClient=pClient;
905 }
906 }
907
908 return 0;
909}
910
911static int read_telegram(struct r3964_info *pInfo, pid_t pid, unsigned char __user *buf)
912{
913 struct r3964_client_info *pClient;
914 struct r3964_block_header *block;
915
916 if(!buf)
917 {
918 return -EINVAL;
919 }
920
921 pClient=findClient(pInfo,pid);
922 if(pClient==NULL)
923 {
924 return -EINVAL;
925 }
926
927 block=pClient->next_block_to_read;
928 if(!block)
929 {
930 return 0;
931 }
932 else
933 {
934 if (copy_to_user (buf, block->data, block->length))
935 return -EFAULT;
936
937 remove_client_block(pInfo, pClient);
938 return block->length;
939 }
940
941 return -EINVAL;
942}
943
944static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
945 int error_code, struct r3964_block_header *pBlock)
946{
947 struct r3964_message *pMsg;
948 unsigned long flags;
949
950 if(pClient->msg_count<R3964_MAX_MSG_COUNT-1)
951 {
952queue_the_message:
953
954 pMsg = kmalloc(sizeof(struct r3964_message), GFP_KERNEL);
87e0f3db 955 TRACE_M("add_msg - kmalloc %p",pMsg);
1da177e4
LT		 956 if(pMsg==NULL) {
957 return;
958 }
959
960 spin_lock_irqsave(&pClient->lock, flags);
961
962 pMsg->msg_id = msg_id;
963 pMsg->arg = arg;
964 pMsg->error_code = error_code;
965 pMsg->block = pBlock;
966 pMsg->next = NULL;
967
968 if(pClient->last_msg==NULL)
969 {
970 pClient->first_msg=pClient->last_msg=pMsg;
971 }
972 else
973 {
974 pClient->last_msg->next = pMsg;
975 pClient->last_msg=pMsg;
976 }
977
978 pClient->msg_count++;
979
980 if(pBlock!=NULL)
981 {
982 pBlock->locks++;
983 }
984 spin_unlock_irqrestore(&pClient->lock, flags);
985 }
986 else
987 {
988 if((pClient->last_msg->msg_id == R3964_MSG_ACK)
989 && (pClient->last_msg->error_code==R3964_OVERFLOW))
990 {
991 pClient->last_msg->arg++;
992 TRACE_PE("add_msg - inc prev OVERFLOW-msg");
993 }
994 else
995 {
996 msg_id = R3964_MSG_ACK;
997 arg = 0;
998 error_code = R3964_OVERFLOW;
999 pBlock = NULL;
1000 TRACE_PE("add_msg - queue OVERFLOW-msg");
1001 goto queue_the_message;
1002 }
1003 }
1004 /* Send SIGIO signal to client process: */
1005 if(pClient->sig_flags & R3964_USE_SIGIO)
1006 {
1007 kill_proc(pClient->pid, SIGIO, 1);
1008 }
1009}
1010
1011static struct r3964_message *remove_msg(struct r3964_info *pInfo,
1012 struct r3964_client_info *pClient)
1013{
1014 struct r3964_message *pMsg=NULL;
1015 unsigned long flags;
1016
1017 if(pClient->first_msg)
1018 {
1019 spin_lock_irqsave(&pClient->lock, flags);
1020
1021 pMsg = pClient->first_msg;
1022 pClient->first_msg = pMsg->next;
1023 if(pClient->first_msg==NULL)
1024 {
1025 pClient->last_msg = NULL;
1026 }
1027
1028 pClient->msg_count--;
1029 if(pMsg->block)
1030 {
1031 remove_client_block(pInfo, pClient);
1032 pClient->next_block_to_read = pMsg->block;
1033 }
1034 spin_unlock_irqrestore(&pClient->lock, flags);
1035 }
1036 return pMsg;
1037}
1038
1039static void remove_client_block(struct r3964_info *pInfo,
1040 struct r3964_client_info *pClient)
1041{
1042 struct r3964_block_header *block;
1043
1044 TRACE_PS("remove_client_block PID %d", pClient->pid);
1045
1046 block=pClient->next_block_to_read;
1047 if(block)
1048 {
1049 block->locks--;
1050 if(block->locks==0)
1051 {
1052 remove_from_rx_queue(pInfo, block);
1053 }
1054 }
1055 pClient->next_block_to_read = NULL;
1056}
1057
1058
1059/*************************************************************
1060 * Line discipline routines
1061 *************************************************************/
1062
1063static int r3964_open(struct tty_struct *tty)
1064{
1065 struct r3964_info *pInfo;
1066
1067 TRACE_L("open");
87e0f3db
AD		 1068 TRACE_L("tty=%p, PID=%d, disc_data=%p",
1069 tty, current->pid, tty->disc_data);
1da177e4
LT		 1070
1071 pInfo=kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
87e0f3db 1072 TRACE_M("r3964_open - info kmalloc %p",pInfo);
1da177e4
LT		 1073
1074 if(!pInfo)
1075 {
1076 printk(KERN_ERR "r3964: failed to alloc info structure\n");
1077 return -ENOMEM;
1078 }
1079
1080 pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
87e0f3db 1081 TRACE_M("r3964_open - rx_buf kmalloc %p",pInfo->rx_buf);
1da177e4
LT		 1082
1083 if(!pInfo->rx_buf)
1084 {
1085 printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
1086 kfree(pInfo);
87e0f3db 1087 TRACE_M("r3964_open - info kfree %p",pInfo);
1da177e4
LT		 1088 return -ENOMEM;
1089 }
1090
1091 pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
87e0f3db 1092 TRACE_M("r3964_open - tx_buf kmalloc %p",pInfo->tx_buf);
1da177e4
LT		 1093
1094 if(!pInfo->tx_buf)
1095 {
1096 printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
1097 kfree(pInfo->rx_buf);
87e0f3db 1098 TRACE_M("r3964_open - rx_buf kfree %p",pInfo->rx_buf);
1da177e4 1099 kfree(pInfo);
87e0f3db 1100 TRACE_M("r3964_open - info kfree %p",pInfo);
1da177e4
LT		 1101 return -ENOMEM;
1102 }
1103
1104 spin_lock_init(&pInfo->lock);
1105 pInfo->tty = tty;
1106 init_waitqueue_head (&pInfo->read_wait);
1107 pInfo->priority = R3964_MASTER;
1108 pInfo->rx_first = pInfo->rx_last = NULL;
1109 pInfo->tx_first = pInfo->tx_last = NULL;
1110 pInfo->rx_position = 0;
1111 pInfo->tx_position = 0;
1112 pInfo->last_rx = 0;
1113 pInfo->blocks_in_rx_queue = 0;
1114 pInfo->firstClient=NULL;
1115 pInfo->state=R3964_IDLE;
1116 pInfo->flags = R3964_DEBUG;
1117 pInfo->nRetry = 0;
1118
1119 tty->disc_data = pInfo;
33f0f88f 1120 tty->receive_room = 65536;
1da177e4
LT		 1121
1122 init_timer(&pInfo->tmr);
1123 pInfo->tmr.data = (unsigned long)pInfo;
1124 pInfo->tmr.function = on_timeout;
1125
1126 return 0;
1127}
1128
1129static void r3964_close(struct tty_struct *tty)
1130{
1131 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1132 struct r3964_client_info *pClient, *pNext;
1133 struct r3964_message *pMsg;
1134 struct r3964_block_header *pHeader, *pNextHeader;
1135 unsigned long flags;
1136
1137 TRACE_L("close");
1138
1139 /*
1140 * Make sure that our task queue isn't activated. If it
1141 * is, take it out of the linked list.
1142 */
1143 del_timer_sync(&pInfo->tmr);
1144
1145 /* Remove client-structs and message queues: */
1146 pClient=pInfo->firstClient;
1147 while(pClient)
1148 {
1149 pNext=pClient->next;
1150 while(pClient->msg_count)
1151 {
1152 pMsg=remove_msg(pInfo, pClient);
1153 if(pMsg)
1154 {
1155 kfree(pMsg);
87e0f3db 1156 TRACE_M("r3964_close - msg kfree %p",pMsg);
1da177e4
LT		 1157 }
1158 }
1159 kfree(pClient);
87e0f3db 1160 TRACE_M("r3964_close - client kfree %p",pClient);
1da177e4
LT		 1161 pClient=pNext;
1162 }
1163 /* Remove jobs from tx_queue: */
1164 spin_lock_irqsave(&pInfo->lock, flags);
1165 pHeader=pInfo->tx_first;
1166 pInfo->tx_first=pInfo->tx_last=NULL;
1167 spin_unlock_irqrestore(&pInfo->lock, flags);
1168
1169 while(pHeader)
1170 {
1171 pNextHeader=pHeader->next;
1172 kfree(pHeader);
1173 pHeader=pNextHeader;
1174 }
1175
1176 /* Free buffers: */
1177 wake_up_interruptible(&pInfo->read_wait);
1178 kfree(pInfo->rx_buf);
87e0f3db 1179 TRACE_M("r3964_close - rx_buf kfree %p",pInfo->rx_buf);
1da177e4 1180 kfree(pInfo->tx_buf);
87e0f3db 1181 TRACE_M("r3964_close - tx_buf kfree %p",pInfo->tx_buf);
1da177e4 1182 kfree(pInfo);
87e0f3db 1183 TRACE_M("r3964_close - info kfree %p",pInfo);
1da177e4
LT		 1184}
1185
1186static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
1187 unsigned char __user *buf, size_t nr)
1188{
1189 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1190 struct r3964_client_info *pClient;
1191 struct r3964_message *pMsg;
1192 struct r3964_client_message theMsg;
1193 DECLARE_WAITQUEUE (wait, current);
1194
1195 int pid = current->pid;
1196 int count;
1197
1198 TRACE_L("read()");
1199
1200 pClient=findClient(pInfo, pid);
1201 if(pClient)
1202 {
1203 pMsg = remove_msg(pInfo, pClient);
1204 if(pMsg==NULL)
1205 {
1206 /* no messages available. */
1207 if (file->f_flags & O_NONBLOCK)
1208 {
1209 return -EAGAIN;
1210 }
1211 /* block until there is a message: */
1212 add_wait_queue(&pInfo->read_wait, &wait);
1213repeat:
1214 current->state = TASK_INTERRUPTIBLE;
1215 pMsg = remove_msg(pInfo, pClient);
1216 if (!pMsg && !signal_pending(current))
1217 {
1218 schedule();
1219 goto repeat;
1220 }
1221 current->state = TASK_RUNNING;
1222 remove_wait_queue(&pInfo->read_wait, &wait);
1223 }
1224
1225 /* If we still haven't got a message, we must have been signalled */
1226
1227 if (!pMsg) return -EINTR;
1228
1229 /* deliver msg to client process: */
1230 theMsg.msg_id = pMsg->msg_id;
1231 theMsg.arg = pMsg->arg;
1232 theMsg.error_code = pMsg->error_code;
1233 count = sizeof(struct r3964_client_message);
1234
1235 kfree(pMsg);
87e0f3db 1236 TRACE_M("r3964_read - msg kfree %p",pMsg);
1da177e4
LT		 1237
1238 if (copy_to_user(buf,&theMsg, count))
1239 return -EFAULT;
1240
1241 TRACE_PS("read - return %d", count);
1242 return count;
1243 }
1244 return -EPERM;
1245}
1246
1247static ssize_t r3964_write(struct tty_struct * tty, struct file * file,
1248 const unsigned char *data, size_t count)
1249{
1250 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1251 struct r3964_block_header *pHeader;
1252 struct r3964_client_info *pClient;
1253 unsigned char *new_data;
1254 int pid;
1255
1256 TRACE_L("write request, %d characters", count);
1257/*
1258 * Verify the pointers
1259 */
1260
1261 if(!pInfo)
1262 return -EIO;
1263
1264/*
1265 * Ensure that the caller does not wish to send too much.
1266 */
1267 if (count > R3964_MTU)
1268 {
1269 if (pInfo->flags & R3964_DEBUG)
1270 {
1271 TRACE_L (KERN_WARNING
1272 "r3964_write: truncating user packet "
1273 "from %u to mtu %d", count, R3964_MTU);
1274 }
1275 count = R3964_MTU;
1276 }
1277/*
1278 * Allocate a buffer for the data and copy it from the buffer with header prepended
1279 */
1280 new_data = kmalloc (count+sizeof(struct r3964_block_header), GFP_KERNEL);
87e0f3db 1281 TRACE_M("r3964_write - kmalloc %p",new_data);
1da177e4
LT		 1282 if (new_data == NULL) {
1283 if (pInfo->flags & R3964_DEBUG)
1284 {
1285 printk (KERN_ERR
1286 "r3964_write: no memory\n");
1287 }
1288 return -ENOSPC;
1289 }
1290
1291 pHeader = (struct r3964_block_header *)new_data;
1292 pHeader->data = new_data + sizeof(struct r3964_block_header);
1293 pHeader->length = count;
1294 pHeader->locks = 0;
1295 pHeader->owner = NULL;
1296
1297 pid=current->pid;
1298
1299 pClient=findClient(pInfo, pid);
1300 if(pClient)
1301 {
1302 pHeader->owner = pClient;
1303 }
1304
1305 memcpy(pHeader->data, data, count); /* We already verified this */
1306
1307 if(pInfo->flags & R3964_DEBUG)
1308 {
1309 dump_block(pHeader->data, count);
1310 }
1311
1312/*
1313 * Add buffer to transmit-queue:
1314 */
1315 add_tx_queue(pInfo, pHeader);
1316 trigger_transmit(pInfo);
1317
1318 return 0;
1319}
1320
1321static int r3964_ioctl(struct tty_struct * tty, struct file * file,
1322 unsigned int cmd, unsigned long arg)
1323{
1324 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1325 if(pInfo==NULL)
1326 return -EINVAL;
1327 switch(cmd)
1328 {
1329 case R3964_ENABLE_SIGNALS:
1330 return enable_signals(pInfo, current->pid, arg);
1331 case R3964_SETPRIORITY:
1332 if(arg<R3964_MASTER || arg>R3964_SLAVE)
1333 return -EINVAL;
1334 pInfo->priority = arg & 0xff;
1335 return 0;
1336 case R3964_USE_BCC:
1337 if(arg)
1338 pInfo->flags |= R3964_BCC;
1339 else
1340 pInfo->flags &= ~R3964_BCC;
1341 return 0;
1342 case R3964_READ_TELEGRAM:
1343 return read_telegram(pInfo, current->pid, (unsigned char __user *)arg);
1344 default:
1345 return -ENOIOCTLCMD;
1346 }
1347}
1348
1349static void r3964_set_termios(struct tty_struct *tty, struct termios * old)
1350{
1351 TRACE_L("set_termios");
1352}
1353
1354/* Called without the kernel lock held - fine */
1355static unsigned int r3964_poll(struct tty_struct * tty, struct file * file,
1356 struct poll_table_struct *wait)
1357{
1358 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1359 int pid=current->pid;
1360 struct r3964_client_info *pClient;
1361 struct r3964_message *pMsg=NULL;
1362 unsigned long flags;
1363 int result = POLLOUT;
1364
1365 TRACE_L("POLL");
1366
1367 pClient=findClient(pInfo,pid);
1368 if(pClient)
1369 {
1370 poll_wait(file, &pInfo->read_wait, wait);
1371 spin_lock_irqsave(&pInfo->lock, flags);
1372 pMsg=pClient->first_msg;
1373 spin_unlock_irqrestore(&pInfo->lock, flags);
1374 if(pMsg)
1375 result |= POLLIN | POLLRDNORM;
1376 }
1377 else
1378 {
1379 result = -EINVAL;
1380 }
1381 return result;
1382}
1383
1384static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
1385 char *fp, int count)
1386{
1387 struct r3964_info *pInfo=(struct r3964_info*)tty->disc_data;
1388 const unsigned char *p;
1389 char *f, flags = 0;
1390 int i;
1391
1392 for (i=count, p = cp, f = fp; i; i--, p++) {
1393 if (f)
1394 flags = *f++;
1395 if(flags==TTY_NORMAL)
1396 {
1397 receive_char(pInfo, *p);
1398 }
1399 else
1400 {
1401 receive_error(pInfo, flags);
1402 }
1403
1404 }
1405}
1406
1da177e4
LT		 1407MODULE_LICENSE("GPL");
1408MODULE_ALIAS_LDISC(N_R3964);
Linux kernel - Deliverables
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