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ia64/kvm: compilation fix. export account_system_vtime.
[pv_ops_mirror.git] / drivers / char / n_r3964.c
blob902169062332483a8449a4f68b8c69756600b544
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 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
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
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
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
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
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
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
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
372 static void put_char(struct r3964_info *pInfo, unsigned char ch)
373 {
374 struct tty_struct *tty = pInfo->tty;
375
376 if (tty == NULL)
377 return;
378
379 /* FIXME: put_char should not be called from an IRQ */
380 if (tty->ops->put_char) {
381 tty->ops->put_char(tty, ch);
382 }
383 pInfo->bcc ^= ch;
384 }
385
386 static void flush(struct r3964_info *pInfo)
387 {
388 struct tty_struct *tty = pInfo->tty;
389
390 if (tty == NULL || tty->ops->flush_chars == NULL)
391 return;
392 tty->ops->flush_chars(tty);
393 }
394
395 static void trigger_transmit(struct r3964_info *pInfo)
396 {
397 unsigned long flags;
398
399 spin_lock_irqsave(&pInfo->lock, flags);
400
401 if ((pInfo->state == R3964_IDLE) && (pInfo->tx_first != NULL)) {
402 pInfo->state = R3964_TX_REQUEST;
403 pInfo->nRetry = 0;
404 pInfo->flags &= ~R3964_ERROR;
405 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
406
407 spin_unlock_irqrestore(&pInfo->lock, flags);
408
409 TRACE_PS("trigger_transmit - sent STX");
410
411 put_char(pInfo, STX);
412 flush(pInfo);
413
414 pInfo->bcc = 0;
415 } else {
416 spin_unlock_irqrestore(&pInfo->lock, flags);
417 }
418 }
419
420 static void retry_transmit(struct r3964_info *pInfo)
421 {
422 if (pInfo->nRetry < R3964_MAX_RETRIES) {
423 TRACE_PE("transmission failed. Retry #%d", pInfo->nRetry);
424 pInfo->bcc = 0;
425 put_char(pInfo, STX);
426 flush(pInfo);
427 pInfo->state = R3964_TX_REQUEST;
428 pInfo->nRetry++;
429 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
430 } else {
431 TRACE_PE("transmission failed after %d retries",
432 R3964_MAX_RETRIES);
433
434 remove_from_tx_queue(pInfo, R3964_TX_FAIL);
435
436 put_char(pInfo, NAK);
437 flush(pInfo);
438 pInfo->state = R3964_IDLE;
439
440 trigger_transmit(pInfo);
441 }
442 }
443
444 static void transmit_block(struct r3964_info *pInfo)
445 {
446 struct tty_struct *tty = pInfo->tty;
447 struct r3964_block_header *pBlock = pInfo->tx_first;
448 int room = 0;
449
450 if (tty == NULL || pBlock == NULL) {
451 return;
452 }
453
454 room = tty_write_room(tty);
455
456 TRACE_PS("transmit_block %p, room %d, length %d",
457 pBlock, room, pBlock->length);
458
459 while (pInfo->tx_position < pBlock->length) {
460 if (room < 2)
461 break;
462
463 if (pBlock->data[pInfo->tx_position] == DLE) {
464 /* send additional DLE char: */
465 put_char(pInfo, DLE);
466 }
467 put_char(pInfo, pBlock->data[pInfo->tx_position++]);
468
469 room--;
470 }
471
472 if ((pInfo->tx_position == pBlock->length) && (room >= 3)) {
473 put_char(pInfo, DLE);
474 put_char(pInfo, ETX);
475 if (pInfo->flags & R3964_BCC) {
476 put_char(pInfo, pInfo->bcc);
477 }
478 pInfo->state = R3964_WAIT_FOR_TX_ACK;
479 mod_timer(&pInfo->tmr, jiffies + R3964_TO_QVZ);
480 }
481 flush(pInfo);
482 }
483
484 static void on_receive_block(struct r3964_info *pInfo)
485 {
486 unsigned int length;
487 struct r3964_client_info *pClient;
488 struct r3964_block_header *pBlock;
489
490 length = pInfo->rx_position;
491
492 /* compare byte checksum characters: */
493 if (pInfo->flags & R3964_BCC) {
494 if (pInfo->bcc != pInfo->last_rx) {
495 TRACE_PE("checksum error - got %x but expected %x",
496 pInfo->last_rx, pInfo->bcc);
497 pInfo->flags |= R3964_CHECKSUM;
498 }
499 }
500
501 /* check for errors (parity, overrun,...): */
502 if (pInfo->flags & R3964_ERROR) {
503 TRACE_PE("on_receive_block - transmission failed error %x",
504 pInfo->flags & R3964_ERROR);
505
506 put_char(pInfo, NAK);
507 flush(pInfo);
508 if (pInfo->nRetry < R3964_MAX_RETRIES) {
509 pInfo->state = R3964_WAIT_FOR_RX_REPEAT;
510 pInfo->nRetry++;
511 mod_timer(&pInfo->tmr, jiffies + R3964_TO_RX_PANIC);
512 } else {
513 TRACE_PE("on_receive_block - failed after max retries");
514 pInfo->state = R3964_IDLE;
515 }
516 return;
517 }
518
519 /* received block; submit DLE: */
520 put_char(pInfo, DLE);
521 flush(pInfo);
522 del_timer_sync(&pInfo->tmr);
523 TRACE_PS(" rx success: got %d chars", length);
524
525 /* prepare struct r3964_block_header: */
526 pBlock = kmalloc(length + sizeof(struct r3964_block_header),
527 GFP_KERNEL);
528 TRACE_M("on_receive_block - kmalloc %p", pBlock);
529
530 if (pBlock == NULL)
531 return;
532
533 pBlock->length = length;
534 pBlock->data = ((unsigned char *)pBlock) +
535 sizeof(struct r3964_block_header);
536 pBlock->locks = 0;
537 pBlock->next = NULL;
538 pBlock->owner = NULL;
539
540 memcpy(pBlock->data, pInfo->rx_buf, length);
541
542 /* queue block into rx_queue: */
543 add_rx_queue(pInfo, pBlock);
544
545 /* notify attached client processes: */
546 for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
547 if (pClient->sig_flags & R3964_SIG_DATA) {
548 add_msg(pClient, R3964_MSG_DATA, length, R3964_OK,
549 pBlock);
550 }
551 }
552 wake_up_interruptible(&pInfo->read_wait);
553
554 pInfo->state = R3964_IDLE;
555
556 trigger_transmit(pInfo);
557 }
558
559 static void receive_char(struct r3964_info *pInfo, const unsigned char c)
560 {
561 switch (pInfo->state) {
562 case R3964_TX_REQUEST:
563 if (c == DLE) {
564 TRACE_PS("TX_REQUEST - got DLE");
565
566 pInfo->state = R3964_TRANSMITTING;
567 pInfo->tx_position = 0;
568
569 transmit_block(pInfo);
570 } else if (c == STX) {
571 if (pInfo->nRetry == 0) {
572 TRACE_PE("TX_REQUEST - init conflict");
573 if (pInfo->priority == R3964_SLAVE) {
574 goto start_receiving;
575 }
576 } else {
577 TRACE_PE("TX_REQUEST - secondary init "
578 "conflict!? Switching to SLAVE mode "
579 "for next rx.");
580 goto start_receiving;
581 }
582 } else {
583 TRACE_PE("TX_REQUEST - char != DLE: %x", c);
584 retry_transmit(pInfo);
585 }
586 break;
587 case R3964_TRANSMITTING:
588 if (c == NAK) {
589 TRACE_PE("TRANSMITTING - got NAK");
590 retry_transmit(pInfo);
591 } else {
592 TRACE_PE("TRANSMITTING - got invalid char");
593
594 pInfo->state = R3964_WAIT_ZVZ_BEFORE_TX_RETRY;
595 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
596 }
597 break;
598 case R3964_WAIT_FOR_TX_ACK:
599 if (c == DLE) {
600 TRACE_PS("WAIT_FOR_TX_ACK - got DLE");
601 remove_from_tx_queue(pInfo, R3964_OK);
602
603 pInfo->state = R3964_IDLE;
604 trigger_transmit(pInfo);
605 } else {
606 retry_transmit(pInfo);
607 }
608 break;
609 case R3964_WAIT_FOR_RX_REPEAT:
610 /* FALLTROUGH */
611 case R3964_IDLE:
612 if (c == STX) {
613 /* Prevent rx_queue from overflow: */
614 if (pInfo->blocks_in_rx_queue >=
615 R3964_MAX_BLOCKS_IN_RX_QUEUE) {
616 TRACE_PE("IDLE - got STX but no space in "
617 "rx_queue!");
618 pInfo->state = R3964_WAIT_FOR_RX_BUF;
619 mod_timer(&pInfo->tmr,
620 jiffies + R3964_TO_NO_BUF);
621 break;
622 }
623 start_receiving:
624 /* Ok, start receiving: */
625 TRACE_PS("IDLE - got STX");
626 pInfo->rx_position = 0;
627 pInfo->last_rx = 0;
628 pInfo->flags &= ~R3964_ERROR;
629 pInfo->state = R3964_RECEIVING;
630 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
631 pInfo->nRetry = 0;
632 put_char(pInfo, DLE);
633 flush(pInfo);
634 pInfo->bcc = 0;
635 }
636 break;
637 case R3964_RECEIVING:
638 if (pInfo->rx_position < RX_BUF_SIZE) {
639 pInfo->bcc ^= c;
640
641 if (c == DLE) {
642 if (pInfo->last_rx == DLE) {
643 pInfo->last_rx = 0;
644 goto char_to_buf;
645 }
646 pInfo->last_rx = DLE;
647 break;
648 } else if ((c == ETX) && (pInfo->last_rx == DLE)) {
649 if (pInfo->flags & R3964_BCC) {
650 pInfo->state = R3964_WAIT_FOR_BCC;
651 mod_timer(&pInfo->tmr,
652 jiffies + R3964_TO_ZVZ);
653 } else {
654 on_receive_block(pInfo);
655 }
656 } else {
657 pInfo->last_rx = c;
658 char_to_buf:
659 pInfo->rx_buf[pInfo->rx_position++] = c;
660 mod_timer(&pInfo->tmr, jiffies + R3964_TO_ZVZ);
661 }
662 }
663 /* else: overflow-msg? BUF_SIZE>MTU; should not happen? */
664 break;
665 case R3964_WAIT_FOR_BCC:
666 pInfo->last_rx = c;
667 on_receive_block(pInfo);
668 break;
669 }
670 }
671
672 static void receive_error(struct r3964_info *pInfo, const char flag)
673 {
674 switch (flag) {
675 case TTY_NORMAL:
676 break;
677 case TTY_BREAK:
678 TRACE_PE("received break");
679 pInfo->flags |= R3964_BREAK;
680 break;
681 case TTY_PARITY:
682 TRACE_PE("parity error");
683 pInfo->flags |= R3964_PARITY;
684 break;
685 case TTY_FRAME:
686 TRACE_PE("frame error");
687 pInfo->flags |= R3964_FRAME;
688 break;
689 case TTY_OVERRUN:
690 TRACE_PE("frame overrun");
691 pInfo->flags |= R3964_OVERRUN;
692 break;
693 default:
694 TRACE_PE("receive_error - unknown flag %d", flag);
695 pInfo->flags |= R3964_UNKNOWN;
696 break;
697 }
698 }
699
700 static void on_timeout(unsigned long priv)
701 {
702 struct r3964_info *pInfo = (void *)priv;
703
704 switch (pInfo->state) {
705 case R3964_TX_REQUEST:
706 TRACE_PE("TX_REQUEST - timeout");
707 retry_transmit(pInfo);
708 break;
709 case R3964_WAIT_ZVZ_BEFORE_TX_RETRY:
710 put_char(pInfo, NAK);
711 flush(pInfo);
712 retry_transmit(pInfo);
713 break;
714 case R3964_WAIT_FOR_TX_ACK:
715 TRACE_PE("WAIT_FOR_TX_ACK - timeout");
716 retry_transmit(pInfo);
717 break;
718 case R3964_WAIT_FOR_RX_BUF:
719 TRACE_PE("WAIT_FOR_RX_BUF - timeout");
720 put_char(pInfo, NAK);
721 flush(pInfo);
722 pInfo->state = R3964_IDLE;
723 break;
724 case R3964_RECEIVING:
725 TRACE_PE("RECEIVING - timeout after %d chars",
726 pInfo->rx_position);
727 put_char(pInfo, NAK);
728 flush(pInfo);
729 pInfo->state = R3964_IDLE;
730 break;
731 case R3964_WAIT_FOR_RX_REPEAT:
732 TRACE_PE("WAIT_FOR_RX_REPEAT - timeout");
733 pInfo->state = R3964_IDLE;
734 break;
735 case R3964_WAIT_FOR_BCC:
736 TRACE_PE("WAIT_FOR_BCC - timeout");
737 put_char(pInfo, NAK);
738 flush(pInfo);
739 pInfo->state = R3964_IDLE;
740 break;
741 }
742 }
743
744 static struct r3964_client_info *findClient(struct r3964_info *pInfo,
745 struct pid *pid)
746 {
747 struct r3964_client_info *pClient;
748
749 for (pClient = pInfo->firstClient; pClient; pClient = pClient->next) {
750 if (pClient->pid == pid) {
751 return pClient;
752 }
753 }
754 return NULL;
755 }
756
757 static int enable_signals(struct r3964_info *pInfo, struct pid *pid, int arg)
758 {
759 struct r3964_client_info *pClient;
760 struct r3964_client_info **ppClient;
761 struct r3964_message *pMsg;
762
763 if ((arg & R3964_SIG_ALL) == 0) {
764 /* Remove client from client list */
765 for (ppClient = &pInfo->firstClient; *ppClient;
766 ppClient = &(*ppClient)->next) {
767 pClient = *ppClient;
768
769 if (pClient->pid == pid) {
770 TRACE_PS("removing client %d from client list",
771 pid_nr(pid));
772 *ppClient = pClient->next;
773 while (pClient->msg_count) {
774 pMsg = remove_msg(pInfo, pClient);
775 if (pMsg) {
776 kfree(pMsg);
777 TRACE_M("enable_signals - msg "
778 "kfree %p", pMsg);
779 }
780 }
781 put_pid(pClient->pid);
782 kfree(pClient);
783 TRACE_M("enable_signals - kfree %p", pClient);
784 return 0;
785 }
786 }
787 return -EINVAL;
788 } else {
789 pClient = findClient(pInfo, pid);
790 if (pClient) {
791 /* update signal options */
792 pClient->sig_flags = arg;
793 } else {
794 /* add client to client list */
795 pClient = kmalloc(sizeof(struct r3964_client_info),
796 GFP_KERNEL);
797 TRACE_M("enable_signals - kmalloc %p", pClient);
798 if (pClient == NULL)
799 return -ENOMEM;
800
801 TRACE_PS("add client %d to client list", pid_nr(pid));
802 spin_lock_init(&pClient->lock);
803 pClient->sig_flags = arg;
804 pClient->pid = get_pid(pid);
805 pClient->next = pInfo->firstClient;
806 pClient->first_msg = NULL;
807 pClient->last_msg = NULL;
808 pClient->next_block_to_read = NULL;
809 pClient->msg_count = 0;
810 pInfo->firstClient = pClient;
811 }
812 }
813
814 return 0;
815 }
816
817 static int read_telegram(struct r3964_info *pInfo, struct pid *pid,
818 unsigned char __user * buf)
819 {
820 struct r3964_client_info *pClient;
821 struct r3964_block_header *block;
822
823 if (!buf) {
824 return -EINVAL;
825 }
826
827 pClient = findClient(pInfo, pid);
828 if (pClient == NULL) {
829 return -EINVAL;
830 }
831
832 block = pClient->next_block_to_read;
833 if (!block) {
834 return 0;
835 } else {
836 if (copy_to_user(buf, block->data, block->length))
837 return -EFAULT;
838
839 remove_client_block(pInfo, pClient);
840 return block->length;
841 }
842
843 return -EINVAL;
844 }
845
846 static void add_msg(struct r3964_client_info *pClient, int msg_id, int arg,
847 int error_code, struct r3964_block_header *pBlock)
848 {
849 struct r3964_message *pMsg;
850 unsigned long flags;
851
852 if (pClient->msg_count < R3964_MAX_MSG_COUNT - 1) {
853 queue_the_message:
854
855 pMsg = kmalloc(sizeof(struct r3964_message),
856 error_code ? GFP_ATOMIC : GFP_KERNEL);
857 TRACE_M("add_msg - kmalloc %p", pMsg);
858 if (pMsg == NULL) {
859 return;
860 }
861
862 spin_lock_irqsave(&pClient->lock, flags);
863
864 pMsg->msg_id = msg_id;
865 pMsg->arg = arg;
866 pMsg->error_code = error_code;
867 pMsg->block = pBlock;
868 pMsg->next = NULL;
869
870 if (pClient->last_msg == NULL) {
871 pClient->first_msg = pClient->last_msg = pMsg;
872 } else {
873 pClient->last_msg->next = pMsg;
874 pClient->last_msg = pMsg;
875 }
876
877 pClient->msg_count++;
878
879 if (pBlock != NULL) {
880 pBlock->locks++;
881 }
882 spin_unlock_irqrestore(&pClient->lock, flags);
883 } else {
884 if ((pClient->last_msg->msg_id == R3964_MSG_ACK)
885 && (pClient->last_msg->error_code == R3964_OVERFLOW)) {
886 pClient->last_msg->arg++;
887 TRACE_PE("add_msg - inc prev OVERFLOW-msg");
888 } else {
889 msg_id = R3964_MSG_ACK;
890 arg = 0;
891 error_code = R3964_OVERFLOW;
892 pBlock = NULL;
893 TRACE_PE("add_msg - queue OVERFLOW-msg");
894 goto queue_the_message;
895 }
896 }
897 /* Send SIGIO signal to client process: */
898 if (pClient->sig_flags & R3964_USE_SIGIO) {
899 kill_pid(pClient->pid, SIGIO, 1);
900 }
901 }
902
903 static struct r3964_message *remove_msg(struct r3964_info *pInfo,
904 struct r3964_client_info *pClient)
905 {
906 struct r3964_message *pMsg = NULL;
907 unsigned long flags;
908
909 if (pClient->first_msg) {
910 spin_lock_irqsave(&pClient->lock, flags);
911
912 pMsg = pClient->first_msg;
913 pClient->first_msg = pMsg->next;
914 if (pClient->first_msg == NULL) {
915 pClient->last_msg = NULL;
916 }
917
918 pClient->msg_count--;
919 if (pMsg->block) {
920 remove_client_block(pInfo, pClient);
921 pClient->next_block_to_read = pMsg->block;
922 }
923 spin_unlock_irqrestore(&pClient->lock, flags);
924 }
925 return pMsg;
926 }
927
928 static void remove_client_block(struct r3964_info *pInfo,
929 struct r3964_client_info *pClient)
930 {
931 struct r3964_block_header *block;
932
933 TRACE_PS("remove_client_block PID %d", pid_nr(pClient->pid));
934
935 block = pClient->next_block_to_read;
936 if (block) {
937 block->locks--;
938 if (block->locks == 0) {
939 remove_from_rx_queue(pInfo, block);
940 }
941 }
942 pClient->next_block_to_read = NULL;
943 }
944
945 /*************************************************************
946 * Line discipline routines
947 *************************************************************/
948
949 static int r3964_open(struct tty_struct *tty)
950 {
951 struct r3964_info *pInfo;
952
953 TRACE_L("open");
954 TRACE_L("tty=%p, PID=%d, disc_data=%p",
955 tty, current->pid, tty->disc_data);
956
957 pInfo = kmalloc(sizeof(struct r3964_info), GFP_KERNEL);
958 TRACE_M("r3964_open - info kmalloc %p", pInfo);
959
960 if (!pInfo) {
961 printk(KERN_ERR "r3964: failed to alloc info structure\n");
962 return -ENOMEM;
963 }
964
965 pInfo->rx_buf = kmalloc(RX_BUF_SIZE, GFP_KERNEL);
966 TRACE_M("r3964_open - rx_buf kmalloc %p", pInfo->rx_buf);
967
968 if (!pInfo->rx_buf) {
969 printk(KERN_ERR "r3964: failed to alloc receive buffer\n");
970 kfree(pInfo);
971 TRACE_M("r3964_open - info kfree %p", pInfo);
972 return -ENOMEM;
973 }
974
975 pInfo->tx_buf = kmalloc(TX_BUF_SIZE, GFP_KERNEL);
976 TRACE_M("r3964_open - tx_buf kmalloc %p", pInfo->tx_buf);
977
978 if (!pInfo->tx_buf) {
979 printk(KERN_ERR "r3964: failed to alloc transmit buffer\n");
980 kfree(pInfo->rx_buf);
981 TRACE_M("r3964_open - rx_buf kfree %p", pInfo->rx_buf);
982 kfree(pInfo);
983 TRACE_M("r3964_open - info kfree %p", pInfo);
984 return -ENOMEM;
985 }
986
987 spin_lock_init(&pInfo->lock);
988 pInfo->tty = tty;
989 init_waitqueue_head(&pInfo->read_wait);
990 pInfo->priority = R3964_MASTER;
991 pInfo->rx_first = pInfo->rx_last = NULL;
992 pInfo->tx_first = pInfo->tx_last = NULL;
993 pInfo->rx_position = 0;
994 pInfo->tx_position = 0;
995 pInfo->last_rx = 0;
996 pInfo->blocks_in_rx_queue = 0;
997 pInfo->firstClient = NULL;
998 pInfo->state = R3964_IDLE;
999 pInfo->flags = R3964_DEBUG;
1000 pInfo->nRetry = 0;
1001
1002 tty->disc_data = pInfo;
1003 tty->receive_room = 65536;
1004
1005 setup_timer(&pInfo->tmr, on_timeout, (unsigned long)pInfo);
1006
1007 return 0;
1008 }
1009
1010 static void r3964_close(struct tty_struct *tty)
1011 {
1012 struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1013 struct r3964_client_info *pClient, *pNext;
1014 struct r3964_message *pMsg;
1015 struct r3964_block_header *pHeader, *pNextHeader;
1016 unsigned long flags;
1017
1018 TRACE_L("close");
1019
1020 /*
1021 * Make sure that our task queue isn't activated. If it
1022 * is, take it out of the linked list.
1023 */
1024 del_timer_sync(&pInfo->tmr);
1025
1026 /* Remove client-structs and message queues: */
1027 pClient = pInfo->firstClient;
1028 while (pClient) {
1029 pNext = pClient->next;
1030 while (pClient->msg_count) {
1031 pMsg = remove_msg(pInfo, pClient);
1032 if (pMsg) {
1033 kfree(pMsg);
1034 TRACE_M("r3964_close - msg kfree %p", pMsg);
1035 }
1036 }
1037 put_pid(pClient->pid);
1038 kfree(pClient);
1039 TRACE_M("r3964_close - client kfree %p", pClient);
1040 pClient = pNext;
1041 }
1042 /* Remove jobs from tx_queue: */
1043 spin_lock_irqsave(&pInfo->lock, flags);
1044 pHeader = pInfo->tx_first;
1045 pInfo->tx_first = pInfo->tx_last = NULL;
1046 spin_unlock_irqrestore(&pInfo->lock, flags);
1047
1048 while (pHeader) {
1049 pNextHeader = pHeader->next;
1050 kfree(pHeader);
1051 pHeader = pNextHeader;
1052 }
1053
1054 /* Free buffers: */
1055 wake_up_interruptible(&pInfo->read_wait);
1056 kfree(pInfo->rx_buf);
1057 TRACE_M("r3964_close - rx_buf kfree %p", pInfo->rx_buf);
1058 kfree(pInfo->tx_buf);
1059 TRACE_M("r3964_close - tx_buf kfree %p", pInfo->tx_buf);
1060 kfree(pInfo);
1061 TRACE_M("r3964_close - info kfree %p", pInfo);
1062 }
1063
1064 static ssize_t r3964_read(struct tty_struct *tty, struct file *file,
1065 unsigned char __user * buf, size_t nr)
1066 {
1067 struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1068 struct r3964_client_info *pClient;
1069 struct r3964_message *pMsg;
1070 struct r3964_client_message theMsg;
1071 int count;
1072
1073 TRACE_L("read()");
1074
1075 lock_kernel();
1076
1077 pClient = findClient(pInfo, task_pid(current));
1078 if (pClient) {
1079 pMsg = remove_msg(pInfo, pClient);
1080 if (pMsg == NULL) {
1081 /* no messages available. */
1082 if (file->f_flags & O_NONBLOCK) {
1083 unlock_kernel();
1084 return -EAGAIN;
1085 }
1086 /* block until there is a message: */
1087 wait_event_interruptible(pInfo->read_wait,
1088 (pMsg = remove_msg(pInfo, pClient)));
1089 }
1090
1091 /* If we still haven't got a message, we must have been signalled */
1092
1093 if (!pMsg) {
1094 unlock_kernel();
1095 return -EINTR;
1096 }
1097
1098 /* deliver msg to client process: */
1099 theMsg.msg_id = pMsg->msg_id;
1100 theMsg.arg = pMsg->arg;
1101 theMsg.error_code = pMsg->error_code;
1102 count = sizeof(struct r3964_client_message);
1103
1104 kfree(pMsg);
1105 TRACE_M("r3964_read - msg kfree %p", pMsg);
1106
1107 if (copy_to_user(buf, &theMsg, count)) {
1108 unlock_kernel();
1109 return -EFAULT;
1110 }
1111
1112 TRACE_PS("read - return %d", count);
1113 return count;
1114 }
1115 unlock_kernel();
1116 return -EPERM;
1117 }
1118
1119 static ssize_t r3964_write(struct tty_struct *tty, struct file *file,
1120 const unsigned char *data, size_t count)
1121 {
1122 struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1123 struct r3964_block_header *pHeader;
1124 struct r3964_client_info *pClient;
1125 unsigned char *new_data;
1126
1127 TRACE_L("write request, %d characters", count);
1128 /*
1129 * Verify the pointers
1130 */
1131
1132 if (!pInfo)
1133 return -EIO;
1134
1135 /*
1136 * Ensure that the caller does not wish to send too much.
1137 */
1138 if (count > R3964_MTU) {
1139 if (pInfo->flags & R3964_DEBUG) {
1140 TRACE_L(KERN_WARNING "r3964_write: truncating user "
1141 "packet from %u to mtu %d", count, R3964_MTU);
1142 }
1143 count = R3964_MTU;
1144 }
1145 /*
1146 * Allocate a buffer for the data and copy it from the buffer with header prepended
1147 */
1148 new_data = kmalloc(count + sizeof(struct r3964_block_header),
1149 GFP_KERNEL);
1150 TRACE_M("r3964_write - kmalloc %p", new_data);
1151 if (new_data == NULL) {
1152 if (pInfo->flags & R3964_DEBUG) {
1153 printk(KERN_ERR "r3964_write: no memory\n");
1154 }
1155 return -ENOSPC;
1156 }
1157
1158 pHeader = (struct r3964_block_header *)new_data;
1159 pHeader->data = new_data + sizeof(struct r3964_block_header);
1160 pHeader->length = count;
1161 pHeader->locks = 0;
1162 pHeader->owner = NULL;
1163
1164 lock_kernel();
1165
1166 pClient = findClient(pInfo, task_pid(current));
1167 if (pClient) {
1168 pHeader->owner = pClient;
1169 }
1170
1171 memcpy(pHeader->data, data, count); /* We already verified this */
1172
1173 if (pInfo->flags & R3964_DEBUG) {
1174 dump_block(pHeader->data, count);
1175 }
1176
1177 /*
1178 * Add buffer to transmit-queue:
1179 */
1180 add_tx_queue(pInfo, pHeader);
1181 trigger_transmit(pInfo);
1182
1183 unlock_kernel();
1184
1185 return 0;
1186 }
1187
1188 static int r3964_ioctl(struct tty_struct *tty, struct file *file,
1189 unsigned int cmd, unsigned long arg)
1190 {
1191 struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1192 if (pInfo == NULL)
1193 return -EINVAL;
1194 switch (cmd) {
1195 case R3964_ENABLE_SIGNALS:
1196 return enable_signals(pInfo, task_pid(current), arg);
1197 case R3964_SETPRIORITY:
1198 if (arg < R3964_MASTER || arg > R3964_SLAVE)
1199 return -EINVAL;
1200 pInfo->priority = arg & 0xff;
1201 return 0;
1202 case R3964_USE_BCC:
1203 if (arg)
1204 pInfo->flags |= R3964_BCC;
1205 else
1206 pInfo->flags &= ~R3964_BCC;
1207 return 0;
1208 case R3964_READ_TELEGRAM:
1209 return read_telegram(pInfo, task_pid(current),
1210 (unsigned char __user *)arg);
1211 default:
1212 return -ENOIOCTLCMD;
1213 }
1214 }
1215
1216 static void r3964_set_termios(struct tty_struct *tty, struct ktermios *old)
1217 {
1218 TRACE_L("set_termios");
1219 }
1220
1221 /* Called without the kernel lock held - fine */
1222 static unsigned int r3964_poll(struct tty_struct *tty, struct file *file,
1223 struct poll_table_struct *wait)
1224 {
1225 struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1226 struct r3964_client_info *pClient;
1227 struct r3964_message *pMsg = NULL;
1228 unsigned long flags;
1229 int result = POLLOUT;
1230
1231 TRACE_L("POLL");
1232
1233 pClient = findClient(pInfo, task_pid(current));
1234 if (pClient) {
1235 poll_wait(file, &pInfo->read_wait, wait);
1236 spin_lock_irqsave(&pInfo->lock, flags);
1237 pMsg = pClient->first_msg;
1238 spin_unlock_irqrestore(&pInfo->lock, flags);
1239 if (pMsg)
1240 result |= POLLIN | POLLRDNORM;
1241 } else {
1242 result = -EINVAL;
1243 }
1244 return result;
1245 }
1246
1247 static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
1248 char *fp, int count)
1249 {
1250 struct r3964_info *pInfo = (struct r3964_info *)tty->disc_data;
1251 const unsigned char *p;
1252 char *f, flags = 0;
1253 int i;
1254
1255 for (i = count, p = cp, f = fp; i; i--, p++) {
1256 if (f)
1257 flags = *f++;
1258 if (flags == TTY_NORMAL) {
1259 receive_char(pInfo, *p);
1260 } else {
1261 receive_error(pInfo, flags);
1262 }
1263
1264 }
1265 }
1266
1267 MODULE_LICENSE("GPL");
1268 MODULE_ALIAS_LDISC(N_R3964);
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