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OMAPDSS: VENC: fix NULL pointer dereference in DSS2 VENC sysfs debug attr on OMAP4
[zen-stable.git] / drivers / tty / n_r3964.c
blob5c6c31459a2f6618cb7cf9d83c7100cf1a6d86ea
1 /* r3964 linediscipline for linux
2 *
3 * -----------------------------------------------------------
4 * Copyright by
5 * Philips Automation Projects
6 * Kassel (Germany)
7 * -----------------------------------------------------------
8 * This software may be used and distributed according to the terms of
9 * the GNU General Public License, incorporated herein by reference.
10 *
11 * Author:
12 * L. Haag
13 *
14 * $Log: n_r3964.c,v $
15 * Revision 1.10 2001/03/18 13:02:24 dwmw2
16 * Fix timer usage, use spinlocks properly.
17 *
18 * Revision 1.9 2001/03/18 12:52:14 dwmw2
19 * Merge changes in 2.4.2
20 *
21 * Revision 1.8 2000/03/23 14:14:54 dwmw2
22 * Fix race in sleeping in r3964_read()
23 *
24 * Revision 1.7 1999/28/08 11:41:50 dwmw2
25 * Port to 2.3 kernel
26 *
27 * Revision 1.6 1998/09/30 00:40:40 dwmw2
28 * Fixed compilation on 2.0.x kernels
29 * Updated to newly registered tty-ldisc number 9
30 *
31 * Revision 1.5 1998/09/04 21:57:36 dwmw2
32 * Signal handling bug fixes, port to 2.1.x.
33 *
34 * Revision 1.4 1998/04/02 20:26:59 lhaag
35 * select, blocking, ...
36 *
37 * Revision 1.3 1998/02/12 18:58:43 root
38 * fixed some memory leaks
39 * calculation of checksum characters
40 *
41 * Revision 1.2 1998/02/07 13:03:34 root
42 * ioctl read_telegram
43 *
44 * Revision 1.1 1998/02/06 19:21:03 root
45 * Initial revision
46 *
47 *
48 */
49
50 #include <linux/module.h>
51 #include <linux/kernel.h>
52 #include <linux/sched.h>
53 #include <linux/types.h>
54 #include <linux/fcntl.h>
55 #include <linux/interrupt.h>
56 #include <linux/ptrace.h>
57 #include <linux/ioport.h>
58 #include <linux/in.h>
59 #include <linux/slab.h>
60 #include <linux/tty.h>
61 #include <linux/errno.h>
62 #include <linux/string.h> /* used in new tty drivers */
63 #include <linux/signal.h> /* used in new tty drivers */
64 #include <linux/ioctl.h>
65 #include <linux/n_r3964.h>
66 #include <linux/poll.h>
67 #include <linux/init.h>
68 #include <asm/uaccess.h>
69
70 /*#define DEBUG_QUEUE*/
71
72 /* Log successful handshake and protocol operations */
73 /*#define DEBUG_PROTO_S*/
74
75 /* Log handshake and protocol errors: */
76 /*#define DEBUG_PROTO_E*/
77
78 /* Log Linediscipline operations (open, close, read, write...): */
79 /*#define DEBUG_LDISC*/
80
81 /* Log module and memory operations (init, cleanup; kmalloc, kfree): */
82 /*#define DEBUG_MODUL*/
83
84 /* Macro helpers for debug output: */
85 #define TRACE(format, args...) printk("r3964: " format "\n" , ## args)
86
87 #ifdef DEBUG_MODUL
88 #define TRACE_M(format, args...) printk("r3964: " format "\n" , ## args)
89 #else
90 #define TRACE_M(fmt, arg...) do {} while (0)
91 #endif
92 #ifdef DEBUG_PROTO_S
93 #define TRACE_PS(format, args...) printk("r3964: " format "\n" , ## args)
94 #else
95 #define TRACE_PS(fmt, arg...) do {} while (0)
96 #endif
97 #ifdef DEBUG_PROTO_E
98 #define TRACE_PE(format, args...) printk("r3964: " format "\n" , ## args)
99 #else
100 #define TRACE_PE(fmt, arg...) do {} while (0)
101 #endif
102 #ifdef DEBUG_LDISC
103 #define TRACE_L(format, args...) printk("r3964: " format "\n" , ## args)
104 #else
105 #define TRACE_L(fmt, arg...) do {} while (0)
106 #endif
107 #ifdef DEBUG_QUEUE
108 #define TRACE_Q(format, args...) printk("r3964: " format "\n" , ## args)
109 #else
110 #define TRACE_Q(fmt, arg...) do {} while (0)
111 #endif
112 static void add_tx_queue(struct r3964_info *, struct r3964_block_header *);
113 static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code);
114 static void put_char(struct r3964_info *pInfo, unsigned char ch);
115 static void trigger_transmit(struct r3964_info *pInfo);
116 static void retry_transmit(struct r3964_info *pInfo);
117 static void transmit_block(struct r3964_info *pInfo);
118 static void receive_char(struct r3964_info *pInfo, const unsigned char c);
119 static void receive_error(struct r3964_info *pInfo, const char flag);
120 static void on_timeout(unsigned long priv);
121 static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg);
122 static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
123 unsigned char __user * buf);
124 static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
125 int error_code, struct r3964_block_header *pBlock);
126 static struct r3964_message *remove_msg(struct r3964_info *pInfo,
127 struct r3964_client_info *pClient);
128 static void remove_client_block(struct r3964_info *pInfo,
129 struct r3964_client_info *pClient);
130
131 static int r3964_open(struct tty_struct *tty);
132 static void r3964_close(struct tty_struct *tty);
133 static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
134 unsigned char __user * buf, size_t nr);
135 static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
136 const unsigned char *buf, size_t nr);
137 static int r3964_ioctl(struct tty_struct *tty, struct file *file,
138 unsigned int cmd, unsigned long arg);
139 static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old);
140 static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
141 struct poll_table_struct *wait);
142 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
143 char *fp, int count);
144
145 static struct tty_ldisc_ops tty_ldisc_N_R3964 = {
146 .owner = THIS_MODULE,
147 .magic = TTY_LDISC_MAGIC,
148 .name = "R3964",
149 .open = r3964_open,
150 .close = r3964_close,
151 .read = r3964_read,
152 .write = r3964_write,
153 .ioctl = r3964_ioctl,
154 .set_termios = r3964_set_termios,
155 .poll = r3964_poll,
156 .receive_buf = r3964_receive_buf,
157 };
158
159 static void dump_block(const unsigned char *block, unsigned int length)
160 {
161 unsigned int i, j;
162 char linebuf[16 * 3 + 1];
163
164 for (i = 0; i < length; i += 16) {
165 for (j = 0; (j < 16) && (j + i < length); j++) {
166 sprintf(linebuf + 3 * j, "%02x ", block[i + j]);
167 }
168 linebuf[3 * j] = '\0';
169 TRACE_PS("%s", linebuf);
170 }
171 }
172
173 /*************************************************************
174 * Driver initialisation
175 *************************************************************/
176
177 /*************************************************************
178 * Module support routines
179 *************************************************************/
180
181 static void __exit r3964_exit(void)
182 {
183 int status;
184
185 TRACE_M("cleanup_module()");
186
187 status = tty_unregister_ldisc(N_R3964);
188
189 if (status != 0) {
190 printk(KERN_ERR "r3964: error unregistering linediscipline: "
191 "%d\n", status);
192 } else {
193 TRACE_L("linediscipline successfully unregistered");
194 }
195 }
196
197 static int __init r3964_init(void)
198 {
199 int status;
200
201 printk("r3964: Philips r3964 Driver $Revision: 1.10 $\n");
202
203 /*
204 * Register the tty line discipline
205 */
206
207 status = tty_register_ldisc(N_R3964, &tty_ldisc_N_R3964);
208 if (status == 0) {
209 TRACE_L("line discipline %d registered", N_R3964);
210 TRACE_L("flags=%x num=%x", tty_ldisc_N_R3964.flags,
211 tty_ldisc_N_R3964.num);
212 TRACE_L("open=%p", tty_ldisc_N_R3964.open);
213 TRACE_L("tty_ldisc_N_R3964 = %p", &tty_ldisc_N_R3964);
214 } else {
215 printk(KERN_ERR "r3964: error registering line discipline: "
216 "%d\n", status);
217 }
218 return status;
219 }
220
221 module_init(r3964_init);
222 module_exit(r3964_exit);
223
224 /*************************************************************
225 * Protocol implementation routines
226 *************************************************************/
227
228 static void add_tx_queue(struct r3964_info *pInfo,
229 struct r3964_block_header *pHeader)
230 {
231 unsigned long flags;
232
233 spin_lock_irqsave(&pInfo->lock, flags);
234
235 pHeader->next = NULL;
236
237 if (pInfo->tx_last == NULL) {
238 pInfo->tx_first = pInfo->tx_last = pHeader;
239 } else {
240 pInfo->tx_last->next = pHeader;
241 pInfo->tx_last = pHeader;
242 }
243
244 spin_unlock_irqrestore(&pInfo->lock, flags);
245
246 TRACE_Q("add_tx_queue %p, length %d, tx_first = %p",
247 pHeader, pHeader->length, pInfo->tx_first);
248 }
249
250 static void remove_from_tx_queue(struct r3964_info *pInfo, int error_code)
251 {
252 struct r3964_block_header *pHeader;
253 unsigned long flags;
254 #ifdef DEBUG_QUEUE
255 struct r3964_block_header *pDump;
256 #endif
257
258 pHeader = pInfo->tx_first;
259
260 if (pHeader == NULL)
261 return;
262
263 #ifdef DEBUG_QUEUE
264 printk("r3964: remove_from_tx_queue: %p, length %u - ",
265 pHeader, pHeader->length);
266 for (pDump = pHeader; pDump; pDump = pDump->next)
267 printk("%p ", pDump);
268 printk("\n");
269 #endif
270
271 if (pHeader->owner) {
272 if (error_code) {
273 add_msg(pHeader->owner, R3964_MSG_ACK, 0,
274 error_code, NULL);
275 } else {
276 add_msg(pHeader->owner, R3964_MSG_ACK, pHeader->length,
277 error_code, NULL);
278 }
279 wake_up_interruptible(&pInfo->read_wait);
280 }
281
282 spin_lock_irqsave(&pInfo->lock, flags);
283
284 pInfo->tx_first = pHeader->next;
285 if (pInfo->tx_first == NULL) {
286 pInfo->tx_last = NULL;
287 }
288
289 spin_unlock_irqrestore(&pInfo->lock, flags);
290
291 kfree(pHeader);
292 TRACE_M("remove_from_tx_queue - kfree %p", pHeader);
293
294 TRACE_Q("remove_from_tx_queue: tx_first = %p, tx_last = %p",
295 pInfo->tx_first, pInfo->tx_last);
296 }
297
298 static void add_rx_queue(struct r3964_info *pInfo,
299 struct r3964_block_header *pHeader)
300 {
301 unsigned long flags;
302
303 spin_lock_irqsave(&pInfo->lock, flags);
304
305 pHeader->next = NULL;
306
307 if (pInfo->rx_last == NULL) {
308 pInfo->rx_first = pInfo->rx_last = pHeader;
309 } else {
310 pInfo->rx_last->next = pHeader;
311 pInfo->rx_last = pHeader;
312 }
313 pInfo->blocks_in_rx_queue++;
314
315 spin_unlock_irqrestore(&pInfo->lock, flags);
316
317 TRACE_Q("add_rx_queue: %p, length = %d, rx_first = %p, count = %d",
318 pHeader, pHeader->length,
319 pInfo->rx_first, pInfo->blocks_in_rx_queue);
320 }
321
322 static void remove_from_rx_queue(struct r3964_info *pInfo,
323 struct r3964_block_header *pHeader)
324 {
325 unsigned long flags;
326 struct r3964_block_header *pFind;
327
328 if (pHeader == NULL)
329 return;
330
331 TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
332 pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
333 TRACE_Q("remove_from_rx_queue: %p, length %u",
334 pHeader, pHeader->length);
335
336 spin_lock_irqsave(&pInfo->lock, flags);
337
338 if (pInfo->rx_first == pHeader) {
339 /* Remove the first block in the linked list: */
340 pInfo->rx_first = pHeader->next;
341
342 if (pInfo->rx_first == NULL) {
343 pInfo->rx_last = NULL;
344 }
345 pInfo->blocks_in_rx_queue--;
346 } else {
347 /* Find block to remove: */
348 for (pFind = pInfo->rx_first; pFind; pFind = pFind->next) {
349 if (pFind->next == pHeader) {
350 /* Got it. */
351 pFind->next = pHeader->next;
352 pInfo->blocks_in_rx_queue--;
353 if (pFind->next == NULL) {
354 /* Oh, removed the last one! */
355 pInfo->rx_last = pFind;
356 }
357 break;
358 }
359 }
360 }
361
362 spin_unlock_irqrestore(&pInfo->lock, flags);
363
364 kfree(pHeader);
365 TRACE_M("remove_from_rx_queue - kfree %p", pHeader);
366
367 TRACE_Q("remove_from_rx_queue: rx_first = %p, rx_last = %p, count = %d",
368 pInfo->rx_first, pInfo->rx_last, pInfo->blocks_in_rx_queue);
369 }
370
371 static void put_char(struct r3964_info *pInfo, unsigned char ch)
372 {
373 struct tty_struct *tty = pInfo->tty;
374 /* FIXME: put_char should not be called from an IRQ */
375 tty_put_char(tty, ch);
376 pInfo->bcc ^= ch;
377 }
378
379 static void flush(struct r3964_info *pInfo)
380 {
381 struct tty_struct *tty = pInfo->tty;
382
383 if (tty == NULL || tty->ops->flush_chars == NULL)
384 return;
385 tty->ops->flush_chars(tty);
386 }
387
388 static void trigger_transmit(struct r3964_info *pInfo)
389 {
390 unsigned long flags;
391
392 spin_lock_irqsave(&pInfo->lock, flags);
393
394 if ((pInfo->state == R3964_IDLE) && (pInfo->tx_first != NULL)) {
395 pInfo->state = R3964_TX_REQUEST;
396 pInfo->nRetry = 0;
397 pInfo->flags &= ~R3964_ERROR;
398 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
399
400 spin_unlock_irqrestore(&pInfo->lock, flags);
401
402 TRACE_PS("trigger_transmit - sent STX");
403
404 put_char(pInfo, STX);
405 flush(pInfo);
406
407 pInfo->bcc = 0;
408 } else {
409 spin_unlock_irqrestore(&pInfo->lock, flags);
410 }
411 }
412
413 static void retry_transmit(struct r3964_info *pInfo)
414 {
415 if (pInfo->nRetry < R3964_MAX_RETRIES) {
416 TRACE_PE("transmission failed. Retry #%d", pInfo->nRetry);
417 pInfo->bcc = 0;
418 put_char(pInfo, STX);
419 flush(pInfo);
420 pInfo->state = R3964_TX_REQUEST;
421 pInfo->nRetry++;
422 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
423 } else {
424 TRACE_PE("transmission failed after %d retries",
425 R3964_MAX_RETRIES);
426
427 remove_from_tx_queue(pInfo, R3964_TX_FAIL);
428
429 put_char(pInfo, NAK);
430 flush(pInfo);
431 pInfo->state = R3964_IDLE;
432
433 trigger_transmit(pInfo);
434 }
435 }
436
437 static void transmit_block(struct r3964_info *pInfo)
438 {
439 struct tty_struct *tty = pInfo->tty;
440 struct r3964_block_header *pBlock = pInfo->tx_first;
441 int room = 0;
442
443 if (tty == NULL || pBlock == NULL) {
444 return;
445 }
446
447 room = tty_write_room(tty);
448
449 TRACE_PS("transmit_block %p, room %d, length %d",
450 pBlock, room, pBlock->length);
451
452 while (pInfo->tx_position < pBlock->length) {
453 if (room < 2)
454 break;
455
456 if (pBlock->data[pInfo->tx_position] == DLE) {
457 /* send additional DLE char: */
458 put_char(pInfo, DLE);
459 }
460 put_char(pInfo, pBlock->data[pInfo->tx_position++]);
461
462 room--;
463 }
464
465 if ((pInfo->tx_position == pBlock->length) && (room >= 3)) {
466 put_char(pInfo, DLE);
467 put_char(pInfo, ETX);
468 if (pInfo->flags & R3964_BCC) {
469 put_char(pInfo, pInfo->bcc);
470 }
471 pInfo->state = R3964_WAIT_FOR_TX_ACK;
472 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
473 }
474 flush(pInfo);
475 }
476
477 static void on_receive_block(struct r3964_info *pInfo)
478 {
479 unsigned int length;
480 struct r3964_client_info *pClient;
481 struct r3964_block_header *pBlock;
482
483 length = pInfo->rx_position;
484
485 /* compare byte checksum characters: */
486 if (pInfo->flags & R3964_BCC) {
487 if (pInfo->bcc != pInfo->last_rx) {
488 TRACE_PE("checksum error - got %x but expected %x",
489 pInfo->last_rx, pInfo->bcc);
490 pInfo->flags |= R3964_CHECKSUM;
491 }
492 }
493
494 /* check for errors (parity, overrun,...): */
495 if (pInfo->flags & R3964_ERROR) {
496 TRACE_PE("on_receive_block - transmission failed error %x",
497 pInfo->flags & R3964_ERROR);
498
499 put_char(pInfo, NAK);
500 flush(pInfo);
501 if (pInfo->nRetry < R3964_MAX_RETRIES) {
502 pInfo->state = R3964_WAIT_FOR_RX_REPEAT;
503 pInfo->nRetry++;
504 mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
505 } else {
506 TRACE_PE("on_receive_block - failed after max retries");
507 pInfo->state = R3964_IDLE;
508 }
509 return;
510 }
511
512 /* received block; submit DLE: */
513 put_char(pInfo, DLE);
514 flush(pInfo);
515 del_timer_sync(&pInfo->tmr);
516 TRACE_PS(" rx success: got %d chars", length);
517
518 /* prepare struct r3964_block_header: */
519 pBlock = kmalloc(length + sizeof(struct r3964_block_header),
520 GFP_KERNEL);
521 TRACE_M("on_receive_block - kmalloc %p", pBlock);
522
523 if (pBlock == NULL)
524 return;
525
526 pBlock->length = length;
527 pBlock->data = ((unsigned char *)pBlock) +
528 sizeof(struct r3964_block_header);
529 pBlock->locks = 0;
530 pBlock->next = NULL;
531 pBlock->owner = NULL;
532
533 memcpy(pBlock->data, pInfo->rx_buf, length);
534
535 /* queue block into rx_queue: */
536 add_rx_queue(pInfo, pBlock);
537
538 /* notify attached client processes: */
539 for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
540 if (pClient->sig_flags & R3964_SIG_DATA) {
541 add_msg(pClient, R3964_MSG_DATA, length, R3964_OK,
542 pBlock);
543 }
544 }
545 wake_up_interruptible(&pInfo->read_wait);
546
547 pInfo->state = R3964_IDLE;
548
549 trigger_transmit(pInfo);
550 }
551
552 static void receive_char(struct r3964_info *pInfo, const unsigned char c)
553 {
554 switch (pInfo->state) {
555 case R3964_TX_REQUEST:
556 if (c == DLE) {
557 TRACE_PS("TX_REQUEST - got DLE");
558
559 pInfo->state = R3964_TRANSMITTING;
560 pInfo->tx_position = 0;
561
562 transmit_block(pInfo);
563 } else if (c == STX) {
564 if (pInfo->nRetry == 0) {
565 TRACE_PE("TX_REQUEST - init conflict");
566 if (pInfo->priority == R3964_SLAVE) {
567 goto start_receiving;
568 }
569 } else {
570 TRACE_PE("TX_REQUEST - secondary init "
571 "conflict!? Switching to SLAVE mode "
572 "for next rx.");
573 goto start_receiving;
574 }
575 } else {
576 TRACE_PE("TX_REQUEST - char != DLE: %x", c);
577 retry_transmit(pInfo);
578 }
579 break;
580 case R3964_TRANSMITTING:
581 if (c == NAK) {
582 TRACE_PE("TRANSMITTING - got NAK");
583 retry_transmit(pInfo);
584 } else {
585 TRACE_PE("TRANSMITTING - got invalid char");
586
587 pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
588 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
589 }
590 break;
591 case R3964_WAIT_FOR_TX_ACK:
592 if (c == DLE) {
593 TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
594 remove_from_tx_queue(pInfo, R3964_OK);
595
596 pInfo->state = R3964_IDLE;
597 trigger_transmit(pInfo);
598 } else {
599 retry_transmit(pInfo);
600 }
601 break;
602 case R3964_WAIT_FOR_RX_REPEAT:
603 /* FALLTHROUGH */
604 case R3964_IDLE:
605 if (c == STX) {
606 /* Prevent rx_queue from overflow: */
607 if (pInfo->blocks_in_rx_queue >=
608 R3964_MAX_BLOCKS_IN_RX_QUEUE) {
609 TRACE_PE("IDLE - got STX but no space in "
610 "rx_queue!");
611 pInfo->state = R3964_WAIT_FOR_RX_BUF;
612 mod_timer(&pInfo->tmr,
613 jiffies + R3964_TO_NO_BUF);
614 break;
615 }
616 start_receiving:
617 /* Ok, start receiving: */
618 TRACE_PS("IDLE - got STX");
619 pInfo->rx_position = 0;
620 pInfo->last_rx = 0;
621 pInfo->flags &= ~R3964_ERROR;
622 pInfo->state = R3964_RECEIVING;
623 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
624 pInfo->nRetry = 0;
625 put_char(pInfo, DLE);
626 flush(pInfo);
627 pInfo->bcc = 0;
628 }
629 break;
630 case R3964_RECEIVING:
631 if (pInfo->rx_position < RX_BUF_SIZE) {
632 pInfo->bcc ^= c;
633
634 if (c == DLE) {
635 if (pInfo->last_rx == DLE) {
636 pInfo->last_rx = 0;
637 goto char_to_buf;
638 }
639 pInfo->last_rx = DLE;
640 break;
641 } else if ((c == ETX) && (pInfo->last_rx == DLE)) {
642 if (pInfo->flags & R3964_BCC) {
643 pInfo->state = R3964_WAIT_FOR_BCC;
644 mod_timer(&pInfo->tmr,
645 jiffies + R3964_TO_ZVZ);
646 } else {
647 on_receive_block(pInfo);
648 }
649 } else {
650 pInfo->last_rx = c;
651 char_to_buf:
652 pInfo->rx_buf[pInfo->rx_position++] = c;
653 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
654 }
655 }
656 /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
657 break;
658 case R3964_WAIT_FOR_BCC:
659 pInfo->last_rx = c;
660 on_receive_block(pInfo);
661 break;
662 }
663 }
664
665 static void receive_error(struct r3964_info *pInfo, const char flag)
666 {
667 switch (flag) {
668 case TTY_NORMAL:
669 break;
670 case TTY_BREAK:
671 TRACE_PE("received break");
672 pInfo->flags |= R3964_BREAK;
673 break;
674 case TTY_PARITY:
675 TRACE_PE("parity error");
676 pInfo->flags |= R3964_PARITY;
677 break;
678 case TTY_FRAME:
679 TRACE_PE("frame error");
680 pInfo->flags |= R3964_FRAME;
681 break;
682 case TTY_OVERRUN:
683 TRACE_PE("frame overrun");
684 pInfo->flags |= R3964_OVERRUN;
685 break;
686 default:
687 TRACE_PE("receive_error - unknown flag %d", flag);
688 pInfo->flags |= R3964_UNKNOWN;
689 break;
690 }
691 }
692
693 static void on_timeout(unsigned long priv)
694 {
695 struct r3964_info *pInfo = (void *)priv;
696
697 switch (pInfo->state) {
698 case R3964_TX_REQUEST:
699 TRACE_PE("TX_REQUEST - timeout");
700 retry_transmit(pInfo);
701 break;
702 case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
703 put_char(pInfo, NAK);
704 flush(pInfo);
705 retry_transmit(pInfo);
706 break;
707 case R3964_WAIT_FOR_TX_ACK:
708 TRACE_PE("WAIT_FOR_TX_ACK - timeout");
709 retry_transmit(pInfo);
710 break;
711 case R3964_WAIT_FOR_RX_BUF:
712 TRACE_PE("WAIT_FOR_RX_BUF - timeout");
713 put_char(pInfo, NAK);
714 flush(pInfo);
715 pInfo->state = R3964_IDLE;
716 break;
717 case R3964_RECEIVING:
718 TRACE_PE("RECEIVING - timeout after %d chars",
719 pInfo->rx_position);
720 put_char(pInfo, NAK);
721 flush(pInfo);
722 pInfo->state = R3964_IDLE;
723 break;
724 case R3964_WAIT_FOR_RX_REPEAT:
725 TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
726 pInfo->state = R3964_IDLE;
727 break;
728 case R3964_WAIT_FOR_BCC:
729 TRACE_PE("WAIT_FOR_BCC - timeout");
730 put_char(pInfo, NAK);
731 flush(pInfo);
732 pInfo->state = R3964_IDLE;
733 break;
734 }
735 }
736
737 static struct r3964_client_info *findClient(struct r3964_info *pInfo,
738 struct pid *pid)
739 {
740 struct r3964_client_info *pClient;
741
742 for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
743 if (pClient->pid == pid) {
744 return pClient;
745 }
746 }
747 return NULL;
748 }
749
750 static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg)
751 {
752 struct r3964_client_info *pClient;
753 struct r3964_client_info **ppClient;
754 struct r3964_message *pMsg;
755
756 if ((arg & R3964_SIG_ALL) == 0) {
757 /* Remove client from client list */
758 for (ppClient = &pInfo->firstClient; *ppClient;
759 ppClient = &(*ppClient)->next) {
760 pClient = *ppClient;
761
762 if (pClient->pid == pid) {
763 TRACE_PS("removing client %d from client list",
764 pid_nr(pid));
765 *ppClient = pClient->next;
766 while (pClient->msg_count) {
767 pMsg = remove_msg(pInfo, pClient);
768 if (pMsg) {
769 kfree(pMsg);
770 TRACE_M("enable_signals - msg "
771 "kfree %p", pMsg);
772 }
773 }
774 put_pid(pClient->pid);
775 kfree(pClient);
776 TRACE_M("enable_signals - kfree %p", pClient);
777 return 0;
778 }
779 }
780 return -EINVAL;
781 } else {
782 pClient = findClient(pInfo, pid);
783 if (pClient) {
784 /* update signal options */
785 pClient->sig_flags = arg;
786 } else {
787 /* add client to client list */
788 pClient = kmalloc(sizeof(struct r3964_client_info),
789 GFP_KERNEL);
790 TRACE_M("enable_signals - kmalloc %p", pClient);
791 if (pClient == NULL)
792 return -ENOMEM;
793
794 TRACE_PS("add client %d to client list", pid_nr(pid));
795 spin_lock_init(&pClient->lock);
796 pClient->sig_flags = arg;
797 pClient->pid = get_pid(pid);
798 pClient->next = pInfo->firstClient;
799 pClient->first_msg = NULL;
800 pClient->last_msg = NULL;
801 pClient->next_block_to_read = NULL;
802 pClient->msg_count = 0;
803 pInfo->firstClient = pClient;
804 }
805 }
806
807 return 0;
808 }
809
810 static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
811 unsigned char __user * buf)
812 {
813 struct r3964_client_info *pClient;
814 struct r3964_block_header *block;
815
816 if (!buf) {
817 return -EINVAL;
818 }
819
820 pClient = findClient(pInfo, pid);
821 if (pClient == NULL) {
822 return -EINVAL;
823 }
824
825 block = pClient->next_block_to_read;
826 if (!block) {
827 return 0;
828 } else {
829 if (copy_to_user(buf, block->data, block->length))
830 return -EFAULT;
831
832 remove_client_block(pInfo, pClient);
833 return block->length;
834 }
835
836 return -EINVAL;
837 }
838
839 static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
840 int error_code, struct r3964_block_header *pBlock)
841 {
842 struct r3964_message *pMsg;
843 unsigned long flags;
844
845 if (pClient->msg_count < R3964_MAX_MSG_COUNT - 1) {
846 queue_the_message:
847
848 pMsg = kmalloc(sizeof(struct r3964_message),
849 error_code ? GFP_ATOMIC : GFP_KERNEL);
850 TRACE_M("add_msg - kmalloc %p", pMsg);
851 if (pMsg == NULL) {
852 return;
853 }
854
855 spin_lock_irqsave(&pClient->lock, flags);
856
857 pMsg->msg_id = msg_id;
858 pMsg->arg = arg;
859 pMsg->error_code = error_code;
860 pMsg->block = pBlock;
861 pMsg->next = NULL;
862
863 if (pClient->last_msg == NULL) {
864 pClient->first_msg = pClient->last_msg = pMsg;
865 } else {
866 pClient->last_msg->next = pMsg;
867 pClient->last_msg = pMsg;
868 }
869
870 pClient->msg_count++;
871
872 if (pBlock != NULL) {
873 pBlock->locks++;
874 }
875 spin_unlock_irqrestore(&pClient->lock, flags);
876 } else {
877 if ((pClient->last_msg->msg_id == R3964_MSG_ACK)
878 && (pClient->last_msg->error_code == R3964_OVERFLOW)) {
879 pClient->last_msg->arg++;
880 TRACE_PE("add_msg - inc prev OVERFLOW-msg");
881 } else {
882 msg_id = R3964_MSG_ACK;
883 arg = 0;
884 error_code = R3964_OVERFLOW;
885 pBlock = NULL;
886 TRACE_PE("add_msg - queue OVERFLOW-msg");
887 goto queue_the_message;
888 }
889 }
890 /* Send SIGIO signal to client process: */
891 if (pClient->sig_flags & R3964_USE_SIGIO) {
892 kill_pid(pClient->pid, SIGIO, 1);
893 }
894 }
895
896 static struct r3964_message *remove_msg(struct r3964_info *pInfo,
897 struct r3964_client_info *pClient)
898 {
899 struct r3964_message *pMsg = NULL;
900 unsigned long flags;
901
902 if (pClient->first_msg) {
903 spin_lock_irqsave(&pClient->lock, flags);
904
905 pMsg = pClient->first_msg;
906 pClient->first_msg = pMsg->next;
907 if (pClient->first_msg == NULL) {
908 pClient->last_msg = NULL;
909 }
910
911 pClient->msg_count--;
912 if (pMsg->block) {
913 remove_client_block(pInfo, pClient);
914 pClient->next_block_to_read = pMsg->block;
915 }
916 spin_unlock_irqrestore(&pClient->lock, flags);
917 }
918 return pMsg;
919 }
920
921 static void remove_client_block(struct r3964_info *pInfo,
922 struct r3964_client_info *pClient)
923 {
924 struct r3964_block_header *block;
925
926 TRACE_PS("remove_client_block PID %d", pid_nr(pClient->pid));
927
928 block = pClient->next_block_to_read;
929 if (block) {
930 block->locks--;
931 if (block->locks == 0) {
932 remove_from_rx_queue(pInfo, block);
933 }
934 }
935 pClient->next_block_to_read = NULL;
936 }
937
938 /*************************************************************
939 * Line discipline routines
940 *************************************************************/
941
942 static int r3964_open(struct tty_struct *tty)
943 {
944 struct r3964_info *pInfo;
945
946 TRACE_L("open");
947 TRACE_L("tty=%p, PID=%d, disc_data=%p",
948 tty, current->pid, tty->disc_data);
949
950 pInfo = kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
951 TRACE_M("r3964_open - info kmalloc %p", pInfo);
952
953 if (!pInfo) {
954 printk(KERN_ERR "r3964: failed to alloc info structure\n");
955 return -ENOMEM;
956 }
957
958 pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
959 TRACE_M("r3964_open - rx_buf kmalloc %p", pInfo->rx_buf);
960
961 if (!pInfo->rx_buf) {
962 printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
963 kfree(pInfo);
964 TRACE_M("r3964_open - info kfree %p", pInfo);
965 return -ENOMEM;
966 }
967
968 pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
969 TRACE_M("r3964_open - tx_buf kmalloc %p", pInfo->tx_buf);
970
971 if (!pInfo->tx_buf) {
972 printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
973 kfree(pInfo->rx_buf);
974 TRACE_M("r3964_open - rx_buf kfree %p", pInfo->rx_buf);
975 kfree(pInfo);
976 TRACE_M("r3964_open - info kfree %p", pInfo);
977 return -ENOMEM;
978 }
979
980 spin_lock_init(&pInfo->lock);
981 pInfo->tty = tty;
982 init_waitqueue_head(&pInfo->read_wait);
983 pInfo->priority = R3964_MASTER;
984 pInfo->rx_first = pInfo->rx_last = NULL;
985 pInfo->tx_first = pInfo->tx_last = NULL;
986 pInfo->rx_position = 0;
987 pInfo->tx_position = 0;
988 pInfo->last_rx = 0;
989 pInfo->blocks_in_rx_queue = 0;
990 pInfo->firstClient = NULL;
991 pInfo->state = R3964_IDLE;
992 pInfo->flags = R3964_DEBUG;
993 pInfo->nRetry = 0;
994
995 tty->disc_data = pInfo;
996 tty->receive_room = 65536;
997
998 setup_timer(&pInfo->tmr, on_timeout, (unsigned long)pInfo);
999
1000 return 0;
1001 }
1002
1003 static void r3964_close(struct tty_struct *tty)
1004 {
1005 struct r3964_info *pInfo = tty->disc_data;
1006 struct r3964_client_info *pClient, *pNext;
1007 struct r3964_message *pMsg;
1008 struct r3964_block_header *pHeader, *pNextHeader;
1009 unsigned long flags;
1010
1011 TRACE_L("close");
1012
1013 /*
1014 * Make sure that our task queue isn't activated. If it
1015 * is, take it out of the linked list.
1016 */
1017 del_timer_sync(&pInfo->tmr);
1018
1019 /* Remove client-structs and message queues: */
1020 pClient = pInfo->firstClient;
1021 while (pClient) {
1022 pNext = pClient->next;
1023 while (pClient->msg_count) {
1024 pMsg = remove_msg(pInfo, pClient);
1025 if (pMsg) {
1026 kfree(pMsg);
1027 TRACE_M("r3964_close - msg kfree %p", pMsg);
1028 }
1029 }
1030 put_pid(pClient->pid);
1031 kfree(pClient);
1032 TRACE_M("r3964_close - client kfree %p", pClient);
1033 pClient = pNext;
1034 }
1035 /* Remove jobs from tx_queue: */
1036 spin_lock_irqsave(&pInfo->lock, flags);
1037 pHeader = pInfo->tx_first;
1038 pInfo->tx_first = pInfo->tx_last = NULL;
1039 spin_unlock_irqrestore(&pInfo->lock, flags);
1040
1041 while (pHeader) {
1042 pNextHeader = pHeader->next;
1043 kfree(pHeader);
1044 pHeader = pNextHeader;
1045 }
1046
1047 /* Free buffers: */
1048 wake_up_interruptible(&pInfo->read_wait);
1049 kfree(pInfo->rx_buf);
1050 TRACE_M("r3964_close - rx_buf kfree %p", pInfo->rx_buf);
1051 kfree(pInfo->tx_buf);
1052 TRACE_M("r3964_close - tx_buf kfree %p", pInfo->tx_buf);
1053 kfree(pInfo);
1054 TRACE_M("r3964_close - info kfree %p", pInfo);
1055 }
1056
1057 static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
1058 unsigned char __user * buf, size_t nr)
1059 {
1060 struct r3964_info *pInfo = tty->disc_data;
1061 struct r3964_client_info *pClient;
1062 struct r3964_message *pMsg;
1063 struct r3964_client_message theMsg;
1064 int ret;
1065
1066 TRACE_L("read()");
1067
1068 tty_lock();
1069
1070 pClient = findClient(pInfo, task_pid(current));
1071 if (pClient) {
1072 pMsg = remove_msg(pInfo, pClient);
1073 if (pMsg == NULL) {
1074 /* no messages available. */
1075 if (file->f_flags & O_NONBLOCK) {
1076 ret = -EAGAIN;
1077 goto unlock;
1078 }
1079 /* block until there is a message: */
1080 wait_event_interruptible_tty(pInfo->read_wait,
1081 (pMsg = remove_msg(pInfo, pClient)));
1082 }
1083
1084 /* If we still haven't got a message, we must have been signalled */
1085
1086 if (!pMsg) {
1087 ret = -EINTR;
1088 goto unlock;
1089 }
1090
1091 /* deliver msg to client process: */
1092 theMsg.msg_id = pMsg->msg_id;
1093 theMsg.arg = pMsg->arg;
1094 theMsg.error_code = pMsg->error_code;
1095 ret = sizeof(struct r3964_client_message);
1096
1097 kfree(pMsg);
1098 TRACE_M("r3964_read - msg kfree %p", pMsg);
1099
1100 if (copy_to_user(buf, &theMsg, ret)) {
1101 ret = -EFAULT;
1102 goto unlock;
1103 }
1104
1105 TRACE_PS("read - return %d", ret);
1106 goto unlock;
1107 }
1108 ret = -EPERM;
1109 unlock:
1110 tty_unlock();
1111 return ret;
1112 }
1113
1114 static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
1115 const unsigned char *data, size_t count)
1116 {
1117 struct r3964_info *pInfo = tty->disc_data;
1118 struct r3964_block_header *pHeader;
1119 struct r3964_client_info *pClient;
1120 unsigned char *new_data;
1121
1122 TRACE_L("write request, %d characters", count);
1123 /*
1124 * Verify the pointers
1125 */
1126
1127 if (!pInfo)
1128 return -EIO;
1129
1130 /*
1131 * Ensure that the caller does not wish to send too much.
1132 */
1133 if (count > R3964_MTU) {
1134 if (pInfo->flags & R3964_DEBUG) {
1135 TRACE_L(KERN_WARNING "r3964_write: truncating user "
1136 "packet from %u to mtu %d", count, R3964_MTU);
1137 }
1138 count = R3964_MTU;
1139 }
1140 /*
1141 * Allocate a buffer for the data and copy it from the buffer with header prepended
1142 */
1143 new_data = kmalloc(count + sizeof(struct r3964_block_header),
1144 GFP_KERNEL);
1145 TRACE_M("r3964_write - kmalloc %p", new_data);
1146 if (new_data == NULL) {
1147 if (pInfo->flags & R3964_DEBUG) {
1148 printk(KERN_ERR "r3964_write: no memory\n");
1149 }
1150 return -ENOSPC;
1151 }
1152
1153 pHeader = (struct r3964_block_header *)new_data;
1154 pHeader->data = new_data + sizeof(struct r3964_block_header);
1155 pHeader->length = count;
1156 pHeader->locks = 0;
1157 pHeader->owner = NULL;
1158
1159 tty_lock();
1160
1161 pClient = findClient(pInfo, task_pid(current));
1162 if (pClient) {
1163 pHeader->owner = pClient;
1164 }
1165
1166 memcpy(pHeader->data, data, count); /* We already verified this */
1167
1168 if (pInfo->flags & R3964_DEBUG) {
1169 dump_block(pHeader->data, count);
1170 }
1171
1172 /*
1173 * Add buffer to transmit-queue:
1174 */
1175 add_tx_queue(pInfo, pHeader);
1176 trigger_transmit(pInfo);
1177
1178 tty_unlock();
1179
1180 return 0;
1181 }
1182
1183 static int r3964_ioctl(struct tty_struct *tty, struct file *file,
1184 unsigned int cmd, unsigned long arg)
1185 {
1186 struct r3964_info *pInfo = tty->disc_data;
1187 if (pInfo == NULL)
1188 return -EINVAL;
1189 switch (cmd) {
1190 case R3964_ENABLE_SIGNALS:
1191 return enable_signals(pInfo, task_pid(current), arg);
1192 case R3964_SETPRIORITY:
1193 if (arg < R3964_MASTER || arg > R3964_SLAVE)
1194 return -EINVAL;
1195 pInfo->priority = arg & 0xff;
1196 return 0;
1197 case R3964_USE_BCC:
1198 if (arg)
1199 pInfo->flags |= R3964_BCC;
1200 else
1201 pInfo->flags &= ~R3964_BCC;
1202 return 0;
1203 case R3964_READ_TELEGRAM:
1204 return read_telegram(pInfo, task_pid(current),
1205 (unsigned char __user *)arg);
1206 default:
1207 return -ENOIOCTLCMD;
1208 }
1209 }
1210
1211 static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old)
1212 {
1213 TRACE_L("set_termios");
1214 }
1215
1216 /* Called without the kernel lock held - fine */
1217 static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
1218 struct poll_table_struct *wait)
1219 {
1220 struct r3964_info *pInfo = tty->disc_data;
1221 struct r3964_client_info *pClient;
1222 struct r3964_message *pMsg = NULL;
1223 unsigned long flags;
1224 int result = POLLOUT;
1225
1226 TRACE_L("POLL");
1227
1228 pClient = findClient(pInfo, task_pid(current));
1229 if (pClient) {
1230 poll_wait(file, &pInfo->read_wait, wait);
1231 spin_lock_irqsave(&pInfo->lock, flags);
1232 pMsg = pClient->first_msg;
1233 spin_unlock_irqrestore(&pInfo->lock, flags);
1234 if (pMsg)
1235 result |= POLLIN | POLLRDNORM;
1236 } else {
1237 result = -EINVAL;
1238 }
1239 return result;
1240 }
1241
1242 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
1243 char *fp, int count)
1244 {
1245 struct r3964_info *pInfo = tty->disc_data;
1246 const unsigned char *p;
1247 char *f, flags = 0;
1248 int i;
1249
1250 for (i = count, p = cp, f = fp; i; i--, p++) {
1251 if (f)
1252 flags = *f++;
1253 if (flags == TTY_NORMAL) {
1254 receive_char(pInfo, *p);
1255 } else {
1256 receive_error(pInfo, flags);
1257 }
1258
1259 }
1260 }
1261
1262 MODULE_LICENSE("GPL");
1263 MODULE_ALIAS_LDISC(N_R3964);