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