media: video: fix clock settings for Tegra VI driver
[linux-2.6.git] / drivers / tty / n_r3964.c
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);