xref: /linux/drivers/isdn/mISDN/dsp_core.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 /*
2  * Author       Andreas Eversberg (jolly@eversberg.eu)
3  * Based on source code structure by
4  *		Karsten Keil (keil@isdn4linux.de)
5  *
6  *		This file is (c) under GNU PUBLIC LICENSE
7  *
8  * Thanks to    Karsten Keil (great drivers)
9  *              Cologne Chip (great chips)
10  *
11  * This module does:
12  *		Real-time tone generation
13  *		DTMF detection
14  *		Real-time cross-connection and conferrence
15  *		Compensate jitter due to system load and hardware fault.
16  *		All features are done in kernel space and will be realized
17  *		using hardware, if available and supported by chip set.
18  *		Blowfish encryption/decryption
19  */
20 
21 /* STRUCTURE:
22  *
23  * The dsp module provides layer 2 for b-channels (64kbit). It provides
24  * transparent audio forwarding with special digital signal processing:
25  *
26  * - (1) generation of tones
27  * - (2) detection of dtmf tones
28  * - (3) crossconnecting and conferences (clocking)
29  * - (4) echo generation for delay test
30  * - (5) volume control
31  * - (6) disable receive data
32  * - (7) pipeline
33  * - (8) encryption/decryption
34  *
35  * Look:
36  *             TX            RX
37  *         ------upper layer------
38  *             |             ^
39  *             |             |(6)
40  *             v             |
41  *       +-----+-------------+-----+
42  *       |(3)(4)                   |
43  *       |           CMX           |
44  *       |                         |
45  *       |           +-------------+
46  *       |           |       ^
47  *       |           |       |
48  *       |+---------+|  +----+----+
49  *       ||(1)      ||  |(2)      |
50  *       ||         ||  |         |
51  *       ||  Tones  ||  |  DTMF   |
52  *       ||         ||  |         |
53  *       ||         ||  |         |
54  *       |+----+----+|  +----+----+
55  *       +-----+-----+       ^
56  *             |             |
57  *             v             |
58  *        +----+----+   +----+----+
59  *        |(5)      |   |(5)      |
60  *        |         |   |         |
61  *        |TX Volume|   |RX Volume|
62  *        |         |   |         |
63  *        |         |   |         |
64  *        +----+----+   +----+----+
65  *             |             ^
66  *             |             |
67  *             v             |
68  *        +----+-------------+----+
69  *        |(7)                    |
70  *        |                       |
71  *        |  Pipeline Processing  |
72  *        |                       |
73  *        |                       |
74  *        +----+-------------+----+
75  *             |             ^
76  *             |             |
77  *             v             |
78  *        +----+----+   +----+----+
79  *        |(8)      |   |(8)      |
80  *        |         |   |         |
81  *        | Encrypt |   | Decrypt |
82  *        |         |   |         |
83  *        |         |   |         |
84  *        +----+----+   +----+----+
85  *             |             ^
86  *             |             |
87  *             v             |
88  *         ------card  layer------
89  *             TX            RX
90  *
91  * Above you can see the logical data flow. If software is used to do the
92  * process, it is actually the real data flow. If hardware is used, data
93  * may not flow, but hardware commands to the card, to provide the data flow
94  * as shown.
95  *
96  * NOTE: The channel must be activated in order to make dsp work, even if
97  * no data flow to the upper layer is intended. Activation can be done
98  * after and before controlling the setting using PH_CONTROL requests.
99  *
100  * DTMF: Will be detected by hardware if possible. It is done before CMX
101  * processing.
102  *
103  * Tones: Will be generated via software if endless looped audio fifos are
104  * not supported by hardware. Tones will override all data from CMX.
105  * It is not required to join a conference to use tones at any time.
106  *
107  * CMX: Is transparent when not used. When it is used, it will do
108  * crossconnections and conferences via software if not possible through
109  * hardware. If hardware capability is available, hardware is used.
110  *
111  * Echo: Is generated by CMX and is used to check performance of hard and
112  * software CMX.
113  *
114  * The CMX has special functions for conferences with one, two and more
115  * members. It will allow different types of data flow. Receive and transmit
116  * data to/form upper layer may be switched on/off individually without losing
117  * features of CMX, Tones and DTMF.
118  *
119  * Echo Cancellation: Sometimes we like to cancel echo from the interface.
120  * Note that a VoIP call may not have echo caused by the IP phone. The echo
121  * is generated by the telephone line connected to it. Because the delay
122  * is high, it becomes an echo. RESULT: Echo Cachelation is required if
123  * both echo AND delay is applied to an interface.
124  * Remember that software CMX always generates a more or less delay.
125  *
126  * If all used features can be realized in hardware, and if transmit and/or
127  * receive data ist disabled, the card may not send/receive any data at all.
128  * Not receiving is useful if only announcements are played. Not sending is
129  * useful if an answering machine records audio. Not sending and receiving is
130  * useful during most states of the call. If supported by hardware, tones
131  * will be played without cpu load. Small PBXs and NT-Mode applications will
132  * not need expensive hardware when processing calls.
133  *
134  *
135  * LOCKING:
136  *
137  * When data is received from upper or lower layer (card), the complete dsp
138  * module is locked by a global lock.  This lock MUST lock irq, because it
139  * must lock timer events by DSP poll timer.
140  * When data is ready to be transmitted down, the data is queued and sent
141  * outside lock and timer event.
142  * PH_CONTROL must not change any settings, join or split conference members
143  * during process of data.
144  *
145  * HDLC:
146  *
147  * It works quite the same as transparent, except that HDLC data is forwarded
148  * to all other conference members if no hardware bridging is possible.
149  * Send data will be writte to sendq. Sendq will be sent if confirm is received.
150  * Conference cannot join, if one member is not hdlc.
151  *
152  */
153 
154 #include <linux/delay.h>
155 #include <linux/gfp.h>
156 #include <linux/mISDNif.h>
157 #include <linux/mISDNdsp.h>
158 #include <linux/module.h>
159 #include <linux/vmalloc.h>
160 #include "core.h"
161 #include "dsp.h"
162 
163 static const char *mISDN_dsp_revision = "2.0";
164 
165 static int debug;
166 static int options;
167 static int poll;
168 static int dtmfthreshold = 100;
169 
170 MODULE_AUTHOR("Andreas Eversberg");
171 module_param(debug, uint, S_IRUGO | S_IWUSR);
172 module_param(options, uint, S_IRUGO | S_IWUSR);
173 module_param(poll, uint, S_IRUGO | S_IWUSR);
174 module_param(dtmfthreshold, uint, S_IRUGO | S_IWUSR);
175 MODULE_DESCRIPTION("mISDN driver for Digital Audio Processing of transparent data");
176 MODULE_LICENSE("GPL");
177 
178 /*int spinnest = 0;*/
179 
180 DEFINE_SPINLOCK(dsp_lock); /* global dsp lock */
181 LIST_HEAD(dsp_ilist);
182 LIST_HEAD(conf_ilist);
183 int dsp_debug;
184 int dsp_options;
185 int dsp_poll, dsp_tics;
186 
187 /* check if rx may be turned off or must be turned on */
188 static void
189 dsp_rx_off_member(struct dsp *dsp)
190 {
191 	struct mISDN_ctrl_req	cq;
192 	int rx_off = 1;
193 
194 	memset(&cq, 0, sizeof(cq));
195 
196 	if (!dsp->features_rx_off)
197 		return;
198 
199 	/* not disabled */
200 	if (!dsp->rx_disabled)
201 		rx_off = 0;
202 	/* software dtmf */
203 	else if (dsp->dtmf.software)
204 		rx_off = 0;
205 	/* echo in software */
206 	else if (dsp->echo.software)
207 		rx_off = 0;
208 	/* bridge in software */
209 	else if (dsp->conf && dsp->conf->software)
210 		rx_off = 0;
211 	/* data is not required by user space and not required
212 	 * for echo dtmf detection, soft-echo, soft-bridging */
213 
214 	if (rx_off == dsp->rx_is_off)
215 		return;
216 
217 	if (!dsp->ch.peer) {
218 		if (dsp_debug & DEBUG_DSP_CORE)
219 			printk(KERN_DEBUG "%s: no peer, no rx_off\n",
220 			       __func__);
221 		return;
222 	}
223 	cq.op = MISDN_CTRL_RX_OFF;
224 	cq.p1 = rx_off;
225 	if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
226 		printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
227 		       __func__);
228 		return;
229 	}
230 	dsp->rx_is_off = rx_off;
231 	if (dsp_debug & DEBUG_DSP_CORE)
232 		printk(KERN_DEBUG "%s: %s set rx_off = %d\n",
233 		       __func__, dsp->name, rx_off);
234 }
235 static void
236 dsp_rx_off(struct dsp *dsp)
237 {
238 	struct dsp_conf_member	*member;
239 
240 	if (dsp_options & DSP_OPT_NOHARDWARE)
241 		return;
242 
243 	/* no conf */
244 	if (!dsp->conf) {
245 		dsp_rx_off_member(dsp);
246 		return;
247 	}
248 	/* check all members in conf */
249 	list_for_each_entry(member, &dsp->conf->mlist, list) {
250 		dsp_rx_off_member(member->dsp);
251 	}
252 }
253 
254 /* enable "fill empty" feature */
255 static void
256 dsp_fill_empty(struct dsp *dsp)
257 {
258 	struct mISDN_ctrl_req	cq;
259 
260 	memset(&cq, 0, sizeof(cq));
261 
262 	if (!dsp->ch.peer) {
263 		if (dsp_debug & DEBUG_DSP_CORE)
264 			printk(KERN_DEBUG "%s: no peer, no fill_empty\n",
265 			       __func__);
266 		return;
267 	}
268 	cq.op = MISDN_CTRL_FILL_EMPTY;
269 	cq.p1 = 1;
270 	cq.p2 = dsp_silence;
271 	if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
272 		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
273 		       __func__);
274 		return;
275 	}
276 	if (dsp_debug & DEBUG_DSP_CORE)
277 		printk(KERN_DEBUG "%s: %s set fill_empty = 1\n",
278 		       __func__, dsp->name);
279 }
280 
281 static int
282 dsp_control_req(struct dsp *dsp, struct mISDNhead *hh, struct sk_buff *skb)
283 {
284 	struct sk_buff	*nskb;
285 	int ret = 0;
286 	int cont;
287 	u8 *data;
288 	int len;
289 
290 	if (skb->len < sizeof(int)) {
291 		printk(KERN_ERR "%s: PH_CONTROL message too short\n", __func__);
292 		return -EINVAL;
293 	}
294 	cont = *((int *)skb->data);
295 	len = skb->len - sizeof(int);
296 	data = skb->data + sizeof(int);
297 
298 	switch (cont) {
299 	case DTMF_TONE_START: /* turn on DTMF */
300 		if (dsp->hdlc) {
301 			ret = -EINVAL;
302 			break;
303 		}
304 		if (dsp_debug & DEBUG_DSP_CORE)
305 			printk(KERN_DEBUG "%s: start dtmf\n", __func__);
306 		if (len == sizeof(int)) {
307 			if (dsp_debug & DEBUG_DSP_CORE)
308 				printk(KERN_NOTICE "changing DTMF Threshold "
309 				       "to %d\n", *((int *)data));
310 			dsp->dtmf.treshold = (*(int *)data) * 10000;
311 		}
312 		dsp->dtmf.enable = 1;
313 		/* init goertzel */
314 		dsp_dtmf_goertzel_init(dsp);
315 
316 		/* check dtmf hardware */
317 		dsp_dtmf_hardware(dsp);
318 		dsp_rx_off(dsp);
319 		break;
320 	case DTMF_TONE_STOP: /* turn off DTMF */
321 		if (dsp_debug & DEBUG_DSP_CORE)
322 			printk(KERN_DEBUG "%s: stop dtmf\n", __func__);
323 		dsp->dtmf.enable = 0;
324 		dsp->dtmf.hardware = 0;
325 		dsp->dtmf.software = 0;
326 		break;
327 	case DSP_CONF_JOIN: /* join / update conference */
328 		if (len < sizeof(int)) {
329 			ret = -EINVAL;
330 			break;
331 		}
332 		if (*((u32 *)data) == 0)
333 			goto conf_split;
334 		if (dsp_debug & DEBUG_DSP_CORE)
335 			printk(KERN_DEBUG "%s: join conference %d\n",
336 			       __func__, *((u32 *)data));
337 		ret = dsp_cmx_conf(dsp, *((u32 *)data));
338 		/* dsp_cmx_hardware will also be called here */
339 		dsp_rx_off(dsp);
340 		if (dsp_debug & DEBUG_DSP_CMX)
341 			dsp_cmx_debug(dsp);
342 		break;
343 	case DSP_CONF_SPLIT: /* remove from conference */
344 	conf_split:
345 		if (dsp_debug & DEBUG_DSP_CORE)
346 			printk(KERN_DEBUG "%s: release conference\n", __func__);
347 		ret = dsp_cmx_conf(dsp, 0);
348 		/* dsp_cmx_hardware will also be called here */
349 		if (dsp_debug & DEBUG_DSP_CMX)
350 			dsp_cmx_debug(dsp);
351 		dsp_rx_off(dsp);
352 		break;
353 	case DSP_TONE_PATT_ON: /* play tone */
354 		if (dsp->hdlc) {
355 			ret = -EINVAL;
356 			break;
357 		}
358 		if (len < sizeof(int)) {
359 			ret = -EINVAL;
360 			break;
361 		}
362 		if (dsp_debug & DEBUG_DSP_CORE)
363 			printk(KERN_DEBUG "%s: turn tone 0x%x on\n",
364 			       __func__, *((int *)skb->data));
365 		ret = dsp_tone(dsp, *((int *)data));
366 		if (!ret) {
367 			dsp_cmx_hardware(dsp->conf, dsp);
368 			dsp_rx_off(dsp);
369 		}
370 		if (!dsp->tone.tone)
371 			goto tone_off;
372 		break;
373 	case DSP_TONE_PATT_OFF: /* stop tone */
374 		if (dsp->hdlc) {
375 			ret = -EINVAL;
376 			break;
377 		}
378 		if (dsp_debug & DEBUG_DSP_CORE)
379 			printk(KERN_DEBUG "%s: turn tone off\n", __func__);
380 		dsp_tone(dsp, 0);
381 		dsp_cmx_hardware(dsp->conf, dsp);
382 		dsp_rx_off(dsp);
383 		/* reset tx buffers (user space data) */
384 	tone_off:
385 		dsp->rx_W = 0;
386 		dsp->rx_R = 0;
387 		break;
388 	case DSP_VOL_CHANGE_TX: /* change volume */
389 		if (dsp->hdlc) {
390 			ret = -EINVAL;
391 			break;
392 		}
393 		if (len < sizeof(int)) {
394 			ret = -EINVAL;
395 			break;
396 		}
397 		dsp->tx_volume = *((int *)data);
398 		if (dsp_debug & DEBUG_DSP_CORE)
399 			printk(KERN_DEBUG "%s: change tx vol to %d\n",
400 			       __func__, dsp->tx_volume);
401 		dsp_cmx_hardware(dsp->conf, dsp);
402 		dsp_dtmf_hardware(dsp);
403 		dsp_rx_off(dsp);
404 		break;
405 	case DSP_VOL_CHANGE_RX: /* change volume */
406 		if (dsp->hdlc) {
407 			ret = -EINVAL;
408 			break;
409 		}
410 		if (len < sizeof(int)) {
411 			ret = -EINVAL;
412 			break;
413 		}
414 		dsp->rx_volume = *((int *)data);
415 		if (dsp_debug & DEBUG_DSP_CORE)
416 			printk(KERN_DEBUG "%s: change rx vol to %d\n",
417 			       __func__, dsp->tx_volume);
418 		dsp_cmx_hardware(dsp->conf, dsp);
419 		dsp_dtmf_hardware(dsp);
420 		dsp_rx_off(dsp);
421 		break;
422 	case DSP_ECHO_ON: /* enable echo */
423 		dsp->echo.software = 1; /* soft echo */
424 		if (dsp_debug & DEBUG_DSP_CORE)
425 			printk(KERN_DEBUG "%s: enable cmx-echo\n", __func__);
426 		dsp_cmx_hardware(dsp->conf, dsp);
427 		dsp_rx_off(dsp);
428 		if (dsp_debug & DEBUG_DSP_CMX)
429 			dsp_cmx_debug(dsp);
430 		break;
431 	case DSP_ECHO_OFF: /* disable echo */
432 		dsp->echo.software = 0;
433 		dsp->echo.hardware = 0;
434 		if (dsp_debug & DEBUG_DSP_CORE)
435 			printk(KERN_DEBUG "%s: disable cmx-echo\n", __func__);
436 		dsp_cmx_hardware(dsp->conf, dsp);
437 		dsp_rx_off(dsp);
438 		if (dsp_debug & DEBUG_DSP_CMX)
439 			dsp_cmx_debug(dsp);
440 		break;
441 	case DSP_RECEIVE_ON: /* enable receive to user space */
442 		if (dsp_debug & DEBUG_DSP_CORE)
443 			printk(KERN_DEBUG "%s: enable receive to user "
444 			       "space\n", __func__);
445 		dsp->rx_disabled = 0;
446 		dsp_rx_off(dsp);
447 		break;
448 	case DSP_RECEIVE_OFF: /* disable receive to user space */
449 		if (dsp_debug & DEBUG_DSP_CORE)
450 			printk(KERN_DEBUG "%s: disable receive to "
451 			       "user space\n", __func__);
452 		dsp->rx_disabled = 1;
453 		dsp_rx_off(dsp);
454 		break;
455 	case DSP_MIX_ON: /* enable mixing of tx data */
456 		if (dsp->hdlc) {
457 			ret = -EINVAL;
458 			break;
459 		}
460 		if (dsp_debug & DEBUG_DSP_CORE)
461 			printk(KERN_DEBUG "%s: enable mixing of "
462 			       "tx-data with conf members\n", __func__);
463 		dsp->tx_mix = 1;
464 		dsp_cmx_hardware(dsp->conf, dsp);
465 		dsp_rx_off(dsp);
466 		if (dsp_debug & DEBUG_DSP_CMX)
467 			dsp_cmx_debug(dsp);
468 		break;
469 	case DSP_MIX_OFF: /* disable mixing of tx data */
470 		if (dsp->hdlc) {
471 			ret = -EINVAL;
472 			break;
473 		}
474 		if (dsp_debug & DEBUG_DSP_CORE)
475 			printk(KERN_DEBUG "%s: disable mixing of "
476 			       "tx-data with conf members\n", __func__);
477 		dsp->tx_mix = 0;
478 		dsp_cmx_hardware(dsp->conf, dsp);
479 		dsp_rx_off(dsp);
480 		if (dsp_debug & DEBUG_DSP_CMX)
481 			dsp_cmx_debug(dsp);
482 		break;
483 	case DSP_TXDATA_ON: /* enable txdata */
484 		dsp->tx_data = 1;
485 		if (dsp_debug & DEBUG_DSP_CORE)
486 			printk(KERN_DEBUG "%s: enable tx-data\n", __func__);
487 		dsp_cmx_hardware(dsp->conf, dsp);
488 		dsp_rx_off(dsp);
489 		if (dsp_debug & DEBUG_DSP_CMX)
490 			dsp_cmx_debug(dsp);
491 		break;
492 	case DSP_TXDATA_OFF: /* disable txdata */
493 		dsp->tx_data = 0;
494 		if (dsp_debug & DEBUG_DSP_CORE)
495 			printk(KERN_DEBUG "%s: disable tx-data\n", __func__);
496 		dsp_cmx_hardware(dsp->conf, dsp);
497 		dsp_rx_off(dsp);
498 		if (dsp_debug & DEBUG_DSP_CMX)
499 			dsp_cmx_debug(dsp);
500 		break;
501 	case DSP_DELAY: /* use delay algorithm instead of dynamic
502 			   jitter algorithm */
503 		if (dsp->hdlc) {
504 			ret = -EINVAL;
505 			break;
506 		}
507 		if (len < sizeof(int)) {
508 			ret = -EINVAL;
509 			break;
510 		}
511 		dsp->cmx_delay = (*((int *)data)) << 3;
512 		/* milliseconds to samples */
513 		if (dsp->cmx_delay >= (CMX_BUFF_HALF >> 1))
514 			/* clip to half of maximum usable buffer
515 			   (half of half buffer) */
516 			dsp->cmx_delay = (CMX_BUFF_HALF >> 1) - 1;
517 		if (dsp_debug & DEBUG_DSP_CORE)
518 			printk(KERN_DEBUG "%s: use delay algorithm to "
519 			       "compensate jitter (%d samples)\n",
520 			       __func__, dsp->cmx_delay);
521 		break;
522 	case DSP_JITTER: /* use dynamic jitter algorithm instead of
523 			    delay algorithm */
524 		if (dsp->hdlc) {
525 			ret = -EINVAL;
526 			break;
527 		}
528 		dsp->cmx_delay = 0;
529 		if (dsp_debug & DEBUG_DSP_CORE)
530 			printk(KERN_DEBUG "%s: use jitter algorithm to "
531 			       "compensate jitter\n", __func__);
532 		break;
533 	case DSP_TX_DEJITTER: /* use dynamic jitter algorithm for tx-buffer */
534 		if (dsp->hdlc) {
535 			ret = -EINVAL;
536 			break;
537 		}
538 		dsp->tx_dejitter = 1;
539 		if (dsp_debug & DEBUG_DSP_CORE)
540 			printk(KERN_DEBUG "%s: use dejitter on TX "
541 			       "buffer\n", __func__);
542 		break;
543 	case DSP_TX_DEJ_OFF: /* use tx-buffer without dejittering*/
544 		if (dsp->hdlc) {
545 			ret = -EINVAL;
546 			break;
547 		}
548 		dsp->tx_dejitter = 0;
549 		if (dsp_debug & DEBUG_DSP_CORE)
550 			printk(KERN_DEBUG "%s: use TX buffer without "
551 			       "dejittering\n", __func__);
552 		break;
553 	case DSP_PIPELINE_CFG:
554 		if (dsp->hdlc) {
555 			ret = -EINVAL;
556 			break;
557 		}
558 		if (len > 0 && ((char *)data)[len - 1]) {
559 			printk(KERN_DEBUG "%s: pipeline config string "
560 			       "is not NULL terminated!\n", __func__);
561 			ret = -EINVAL;
562 		} else {
563 			dsp->pipeline.inuse = 1;
564 			dsp_cmx_hardware(dsp->conf, dsp);
565 			ret = dsp_pipeline_build(&dsp->pipeline,
566 						 len > 0 ? data : NULL);
567 			dsp_cmx_hardware(dsp->conf, dsp);
568 			dsp_rx_off(dsp);
569 		}
570 		break;
571 	case DSP_BF_ENABLE_KEY: /* turn blowfish on */
572 		if (dsp->hdlc) {
573 			ret = -EINVAL;
574 			break;
575 		}
576 		if (len < 4 || len > 56) {
577 			ret = -EINVAL;
578 			break;
579 		}
580 		if (dsp_debug & DEBUG_DSP_CORE)
581 			printk(KERN_DEBUG "%s: turn blowfish on (key "
582 			       "not shown)\n", __func__);
583 		ret = dsp_bf_init(dsp, (u8 *)data, len);
584 		/* set new cont */
585 		if (!ret)
586 			cont = DSP_BF_ACCEPT;
587 		else
588 			cont = DSP_BF_REJECT;
589 		/* send indication if it worked to set it */
590 		nskb = _alloc_mISDN_skb(PH_CONTROL_IND, MISDN_ID_ANY,
591 					sizeof(int), &cont, GFP_ATOMIC);
592 		if (nskb) {
593 			if (dsp->up) {
594 				if (dsp->up->send(dsp->up, nskb))
595 					dev_kfree_skb(nskb);
596 			} else
597 				dev_kfree_skb(nskb);
598 		}
599 		if (!ret) {
600 			dsp_cmx_hardware(dsp->conf, dsp);
601 			dsp_dtmf_hardware(dsp);
602 			dsp_rx_off(dsp);
603 		}
604 		break;
605 	case DSP_BF_DISABLE: /* turn blowfish off */
606 		if (dsp->hdlc) {
607 			ret = -EINVAL;
608 			break;
609 		}
610 		if (dsp_debug & DEBUG_DSP_CORE)
611 			printk(KERN_DEBUG "%s: turn blowfish off\n", __func__);
612 		dsp_bf_cleanup(dsp);
613 		dsp_cmx_hardware(dsp->conf, dsp);
614 		dsp_dtmf_hardware(dsp);
615 		dsp_rx_off(dsp);
616 		break;
617 	default:
618 		if (dsp_debug & DEBUG_DSP_CORE)
619 			printk(KERN_DEBUG "%s: ctrl req %x unhandled\n",
620 			       __func__, cont);
621 		ret = -EINVAL;
622 	}
623 	return ret;
624 }
625 
626 static void
627 get_features(struct mISDNchannel *ch)
628 {
629 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
630 	struct mISDN_ctrl_req	cq;
631 
632 	if (!ch->peer) {
633 		if (dsp_debug & DEBUG_DSP_CORE)
634 			printk(KERN_DEBUG "%s: no peer, no features\n",
635 			       __func__);
636 		return;
637 	}
638 	memset(&cq, 0, sizeof(cq));
639 	cq.op = MISDN_CTRL_GETOP;
640 	if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq) < 0) {
641 		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
642 		       __func__);
643 		return;
644 	}
645 	if (cq.op & MISDN_CTRL_RX_OFF)
646 		dsp->features_rx_off = 1;
647 	if (cq.op & MISDN_CTRL_FILL_EMPTY)
648 		dsp->features_fill_empty = 1;
649 	if (dsp_options & DSP_OPT_NOHARDWARE)
650 		return;
651 	if ((cq.op & MISDN_CTRL_HW_FEATURES_OP)) {
652 		cq.op = MISDN_CTRL_HW_FEATURES;
653 		*((u_long *)&cq.p1) = (u_long)&dsp->features;
654 		if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq)) {
655 			printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
656 			       __func__);
657 		}
658 	} else
659 		if (dsp_debug & DEBUG_DSP_CORE)
660 			printk(KERN_DEBUG "%s: features not supported for %s\n",
661 			       __func__, dsp->name);
662 }
663 
664 static int
665 dsp_function(struct mISDNchannel *ch,  struct sk_buff *skb)
666 {
667 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
668 	struct mISDNhead	*hh;
669 	int			ret = 0;
670 	u8			*digits = NULL;
671 	u_long			flags;
672 
673 	hh = mISDN_HEAD_P(skb);
674 	switch (hh->prim) {
675 		/* FROM DOWN */
676 	case (PH_DATA_CNF):
677 		dsp->data_pending = 0;
678 		/* trigger next hdlc frame, if any */
679 		if (dsp->hdlc) {
680 			spin_lock_irqsave(&dsp_lock, flags);
681 			if (dsp->b_active)
682 				schedule_work(&dsp->workq);
683 			spin_unlock_irqrestore(&dsp_lock, flags);
684 		}
685 		break;
686 	case (PH_DATA_IND):
687 	case (DL_DATA_IND):
688 		if (skb->len < 1) {
689 			ret = -EINVAL;
690 			break;
691 		}
692 		if (dsp->rx_is_off) {
693 			if (dsp_debug & DEBUG_DSP_CORE)
694 				printk(KERN_DEBUG "%s: rx-data during rx_off"
695 				       " for %s\n",
696 				       __func__, dsp->name);
697 		}
698 		if (dsp->hdlc) {
699 			/* hdlc */
700 			spin_lock_irqsave(&dsp_lock, flags);
701 			dsp_cmx_hdlc(dsp, skb);
702 			spin_unlock_irqrestore(&dsp_lock, flags);
703 			if (dsp->rx_disabled) {
704 				/* if receive is not allowed */
705 				break;
706 			}
707 			hh->prim = DL_DATA_IND;
708 			if (dsp->up)
709 				return dsp->up->send(dsp->up, skb);
710 			break;
711 		}
712 
713 		spin_lock_irqsave(&dsp_lock, flags);
714 
715 		/* decrypt if enabled */
716 		if (dsp->bf_enable)
717 			dsp_bf_decrypt(dsp, skb->data, skb->len);
718 		/* pipeline */
719 		if (dsp->pipeline.inuse)
720 			dsp_pipeline_process_rx(&dsp->pipeline, skb->data,
721 						skb->len, hh->id);
722 		/* change volume if requested */
723 		if (dsp->rx_volume)
724 			dsp_change_volume(skb, dsp->rx_volume);
725 		/* check if dtmf soft decoding is turned on */
726 		if (dsp->dtmf.software) {
727 			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
728 							  skb->len, (dsp_options & DSP_OPT_ULAW) ? 1 : 0);
729 		}
730 		/* we need to process receive data if software */
731 		if (dsp->conf && dsp->conf->software) {
732 			/* process data from card at cmx */
733 			dsp_cmx_receive(dsp, skb);
734 		}
735 
736 		spin_unlock_irqrestore(&dsp_lock, flags);
737 
738 		/* send dtmf result, if any */
739 		if (digits) {
740 			while (*digits) {
741 				int k;
742 				struct sk_buff *nskb;
743 				if (dsp_debug & DEBUG_DSP_DTMF)
744 					printk(KERN_DEBUG "%s: digit"
745 					       "(%c) to layer %s\n",
746 					       __func__, *digits, dsp->name);
747 				k = *digits | DTMF_TONE_VAL;
748 				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
749 							MISDN_ID_ANY, sizeof(int), &k,
750 							GFP_ATOMIC);
751 				if (nskb) {
752 					if (dsp->up) {
753 						if (dsp->up->send(
754 							    dsp->up, nskb))
755 							dev_kfree_skb(nskb);
756 					} else
757 						dev_kfree_skb(nskb);
758 				}
759 				digits++;
760 			}
761 		}
762 		if (dsp->rx_disabled) {
763 			/* if receive is not allowed */
764 			break;
765 		}
766 		hh->prim = DL_DATA_IND;
767 		if (dsp->up)
768 			return dsp->up->send(dsp->up, skb);
769 		break;
770 	case (PH_CONTROL_IND):
771 		if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
772 			printk(KERN_DEBUG "%s: PH_CONTROL INDICATION "
773 			       "received: %x (len %d) %s\n", __func__,
774 			       hh->id, skb->len, dsp->name);
775 		switch (hh->id) {
776 		case (DTMF_HFC_COEF): /* getting coefficients */
777 			if (!dsp->dtmf.hardware) {
778 				if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
779 					printk(KERN_DEBUG "%s: ignoring DTMF "
780 					       "coefficients from HFC\n",
781 					       __func__);
782 				break;
783 			}
784 			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
785 							  skb->len, 2);
786 			while (*digits) {
787 				int k;
788 				struct sk_buff *nskb;
789 				if (dsp_debug & DEBUG_DSP_DTMF)
790 					printk(KERN_DEBUG "%s: digit"
791 					       "(%c) to layer %s\n",
792 					       __func__, *digits, dsp->name);
793 				k = *digits | DTMF_TONE_VAL;
794 				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
795 							MISDN_ID_ANY, sizeof(int), &k,
796 							GFP_ATOMIC);
797 				if (nskb) {
798 					if (dsp->up) {
799 						if (dsp->up->send(
800 							    dsp->up, nskb))
801 							dev_kfree_skb(nskb);
802 					} else
803 						dev_kfree_skb(nskb);
804 				}
805 				digits++;
806 			}
807 			break;
808 		case (HFC_VOL_CHANGE_TX): /* change volume */
809 			if (skb->len != sizeof(int)) {
810 				ret = -EINVAL;
811 				break;
812 			}
813 			spin_lock_irqsave(&dsp_lock, flags);
814 			dsp->tx_volume = *((int *)skb->data);
815 			if (dsp_debug & DEBUG_DSP_CORE)
816 				printk(KERN_DEBUG "%s: change tx volume to "
817 				       "%d\n", __func__, dsp->tx_volume);
818 			dsp_cmx_hardware(dsp->conf, dsp);
819 			dsp_dtmf_hardware(dsp);
820 			dsp_rx_off(dsp);
821 			spin_unlock_irqrestore(&dsp_lock, flags);
822 			break;
823 		default:
824 			if (dsp_debug & DEBUG_DSP_CORE)
825 				printk(KERN_DEBUG "%s: ctrl ind %x unhandled "
826 				       "%s\n", __func__, hh->id, dsp->name);
827 			ret = -EINVAL;
828 		}
829 		break;
830 	case (PH_ACTIVATE_IND):
831 	case (PH_ACTIVATE_CNF):
832 		if (dsp_debug & DEBUG_DSP_CORE)
833 			printk(KERN_DEBUG "%s: b_channel is now active %s\n",
834 			       __func__, dsp->name);
835 		/* bchannel now active */
836 		spin_lock_irqsave(&dsp_lock, flags);
837 		dsp->b_active = 1;
838 		dsp->data_pending = 0;
839 		dsp->rx_init = 1;
840 		/* rx_W and rx_R will be adjusted on first frame */
841 		dsp->rx_W = 0;
842 		dsp->rx_R = 0;
843 		memset(dsp->rx_buff, 0, sizeof(dsp->rx_buff));
844 		dsp_cmx_hardware(dsp->conf, dsp);
845 		dsp_dtmf_hardware(dsp);
846 		dsp_rx_off(dsp);
847 		spin_unlock_irqrestore(&dsp_lock, flags);
848 		if (dsp_debug & DEBUG_DSP_CORE)
849 			printk(KERN_DEBUG "%s: done with activation, sending "
850 			       "confirm to user space. %s\n", __func__,
851 			       dsp->name);
852 		/* send activation to upper layer */
853 		hh->prim = DL_ESTABLISH_CNF;
854 		if (dsp->up)
855 			return dsp->up->send(dsp->up, skb);
856 		break;
857 	case (PH_DEACTIVATE_IND):
858 	case (PH_DEACTIVATE_CNF):
859 		if (dsp_debug & DEBUG_DSP_CORE)
860 			printk(KERN_DEBUG "%s: b_channel is now inactive %s\n",
861 			       __func__, dsp->name);
862 		/* bchannel now inactive */
863 		spin_lock_irqsave(&dsp_lock, flags);
864 		dsp->b_active = 0;
865 		dsp->data_pending = 0;
866 		dsp_cmx_hardware(dsp->conf, dsp);
867 		dsp_rx_off(dsp);
868 		spin_unlock_irqrestore(&dsp_lock, flags);
869 		hh->prim = DL_RELEASE_CNF;
870 		if (dsp->up)
871 			return dsp->up->send(dsp->up, skb);
872 		break;
873 		/* FROM UP */
874 	case (DL_DATA_REQ):
875 	case (PH_DATA_REQ):
876 		if (skb->len < 1) {
877 			ret = -EINVAL;
878 			break;
879 		}
880 		if (dsp->hdlc) {
881 			/* hdlc */
882 			if (!dsp->b_active) {
883 				ret = -EIO;
884 				break;
885 			}
886 			hh->prim = PH_DATA_REQ;
887 			spin_lock_irqsave(&dsp_lock, flags);
888 			skb_queue_tail(&dsp->sendq, skb);
889 			schedule_work(&dsp->workq);
890 			spin_unlock_irqrestore(&dsp_lock, flags);
891 			return 0;
892 		}
893 		/* send data to tx-buffer (if no tone is played) */
894 		if (!dsp->tone.tone) {
895 			spin_lock_irqsave(&dsp_lock, flags);
896 			dsp_cmx_transmit(dsp, skb);
897 			spin_unlock_irqrestore(&dsp_lock, flags);
898 		}
899 		break;
900 	case (PH_CONTROL_REQ):
901 		spin_lock_irqsave(&dsp_lock, flags);
902 		ret = dsp_control_req(dsp, hh, skb);
903 		spin_unlock_irqrestore(&dsp_lock, flags);
904 		break;
905 	case (DL_ESTABLISH_REQ):
906 	case (PH_ACTIVATE_REQ):
907 		if (dsp_debug & DEBUG_DSP_CORE)
908 			printk(KERN_DEBUG "%s: activating b_channel %s\n",
909 			       __func__, dsp->name);
910 		if (dsp->dtmf.hardware || dsp->dtmf.software)
911 			dsp_dtmf_goertzel_init(dsp);
912 		get_features(ch);
913 		/* enable fill_empty feature */
914 		if (dsp->features_fill_empty)
915 			dsp_fill_empty(dsp);
916 		/* send ph_activate */
917 		hh->prim = PH_ACTIVATE_REQ;
918 		if (ch->peer)
919 			return ch->recv(ch->peer, skb);
920 		break;
921 	case (DL_RELEASE_REQ):
922 	case (PH_DEACTIVATE_REQ):
923 		if (dsp_debug & DEBUG_DSP_CORE)
924 			printk(KERN_DEBUG "%s: releasing b_channel %s\n",
925 			       __func__, dsp->name);
926 		spin_lock_irqsave(&dsp_lock, flags);
927 		dsp->tone.tone = 0;
928 		dsp->tone.hardware = 0;
929 		dsp->tone.software = 0;
930 		if (timer_pending(&dsp->tone.tl))
931 			del_timer(&dsp->tone.tl);
932 		if (dsp->conf)
933 			dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be
934 						 called here */
935 		skb_queue_purge(&dsp->sendq);
936 		spin_unlock_irqrestore(&dsp_lock, flags);
937 		hh->prim = PH_DEACTIVATE_REQ;
938 		if (ch->peer)
939 			return ch->recv(ch->peer, skb);
940 		break;
941 	default:
942 		if (dsp_debug & DEBUG_DSP_CORE)
943 			printk(KERN_DEBUG "%s: msg %x unhandled %s\n",
944 			       __func__, hh->prim, dsp->name);
945 		ret = -EINVAL;
946 	}
947 	if (!ret)
948 		dev_kfree_skb(skb);
949 	return ret;
950 }
951 
952 static int
953 dsp_ctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
954 {
955 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
956 	u_long		flags;
957 
958 	if (debug & DEBUG_DSP_CTRL)
959 		printk(KERN_DEBUG "%s:(%x)\n", __func__, cmd);
960 
961 	switch (cmd) {
962 	case OPEN_CHANNEL:
963 		break;
964 	case CLOSE_CHANNEL:
965 		if (dsp->ch.peer)
966 			dsp->ch.peer->ctrl(dsp->ch.peer, CLOSE_CHANNEL, NULL);
967 
968 		/* wait until workqueue has finished,
969 		 * must lock here, or we may hit send-process currently
970 		 * queueing. */
971 		spin_lock_irqsave(&dsp_lock, flags);
972 		dsp->b_active = 0;
973 		spin_unlock_irqrestore(&dsp_lock, flags);
974 		/* MUST not be locked, because it waits until queue is done. */
975 		cancel_work_sync(&dsp->workq);
976 		spin_lock_irqsave(&dsp_lock, flags);
977 		if (timer_pending(&dsp->tone.tl))
978 			del_timer(&dsp->tone.tl);
979 		skb_queue_purge(&dsp->sendq);
980 		if (dsp_debug & DEBUG_DSP_CTRL)
981 			printk(KERN_DEBUG "%s: releasing member %s\n",
982 			       __func__, dsp->name);
983 		dsp->b_active = 0;
984 		dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be called
985 					 here */
986 		dsp_pipeline_destroy(&dsp->pipeline);
987 
988 		if (dsp_debug & DEBUG_DSP_CTRL)
989 			printk(KERN_DEBUG "%s: remove & destroy object %s\n",
990 			       __func__, dsp->name);
991 		list_del(&dsp->list);
992 		spin_unlock_irqrestore(&dsp_lock, flags);
993 
994 		if (dsp_debug & DEBUG_DSP_CTRL)
995 			printk(KERN_DEBUG "%s: dsp instance released\n",
996 			       __func__);
997 		vfree(dsp);
998 		module_put(THIS_MODULE);
999 		break;
1000 	}
1001 	return 0;
1002 }
1003 
1004 static void
1005 dsp_send_bh(struct work_struct *work)
1006 {
1007 	struct dsp *dsp = container_of(work, struct dsp, workq);
1008 	struct sk_buff *skb;
1009 	struct mISDNhead	*hh;
1010 
1011 	if (dsp->hdlc && dsp->data_pending)
1012 		return; /* wait until data has been acknowledged */
1013 
1014 	/* send queued data */
1015 	while ((skb = skb_dequeue(&dsp->sendq))) {
1016 		/* in locked date, we must have still data in queue */
1017 		if (dsp->data_pending) {
1018 			if (dsp_debug & DEBUG_DSP_CORE)
1019 				printk(KERN_DEBUG "%s: fifo full %s, this is "
1020 				       "no bug!\n", __func__, dsp->name);
1021 			/* flush transparent data, if not acked */
1022 			dev_kfree_skb(skb);
1023 			continue;
1024 		}
1025 		hh = mISDN_HEAD_P(skb);
1026 		if (hh->prim == DL_DATA_REQ) {
1027 			/* send packet up */
1028 			if (dsp->up) {
1029 				if (dsp->up->send(dsp->up, skb))
1030 					dev_kfree_skb(skb);
1031 			} else
1032 				dev_kfree_skb(skb);
1033 		} else {
1034 			/* send packet down */
1035 			if (dsp->ch.peer) {
1036 				dsp->data_pending = 1;
1037 				if (dsp->ch.recv(dsp->ch.peer, skb)) {
1038 					dev_kfree_skb(skb);
1039 					dsp->data_pending = 0;
1040 				}
1041 			} else
1042 				dev_kfree_skb(skb);
1043 		}
1044 	}
1045 }
1046 
1047 static int
1048 dspcreate(struct channel_req *crq)
1049 {
1050 	struct dsp		*ndsp;
1051 	u_long		flags;
1052 
1053 	if (crq->protocol != ISDN_P_B_L2DSP
1054 	    && crq->protocol != ISDN_P_B_L2DSPHDLC)
1055 		return -EPROTONOSUPPORT;
1056 	ndsp = vzalloc(sizeof(struct dsp));
1057 	if (!ndsp) {
1058 		printk(KERN_ERR "%s: vmalloc struct dsp failed\n", __func__);
1059 		return -ENOMEM;
1060 	}
1061 	if (dsp_debug & DEBUG_DSP_CTRL)
1062 		printk(KERN_DEBUG "%s: creating new dsp instance\n", __func__);
1063 
1064 	/* default enabled */
1065 	INIT_WORK(&ndsp->workq, (void *)dsp_send_bh);
1066 	skb_queue_head_init(&ndsp->sendq);
1067 	ndsp->ch.send = dsp_function;
1068 	ndsp->ch.ctrl = dsp_ctrl;
1069 	ndsp->up = crq->ch;
1070 	crq->ch = &ndsp->ch;
1071 	if (crq->protocol == ISDN_P_B_L2DSP) {
1072 		crq->protocol = ISDN_P_B_RAW;
1073 		ndsp->hdlc = 0;
1074 	} else {
1075 		crq->protocol = ISDN_P_B_HDLC;
1076 		ndsp->hdlc = 1;
1077 	}
1078 	if (!try_module_get(THIS_MODULE))
1079 		printk(KERN_WARNING "%s:cannot get module\n",
1080 		       __func__);
1081 
1082 	sprintf(ndsp->name, "DSP_C%x(0x%p)",
1083 		ndsp->up->st->dev->id + 1, ndsp);
1084 	/* set frame size to start */
1085 	ndsp->features.hfc_id = -1; /* current PCM id */
1086 	ndsp->features.pcm_id = -1; /* current PCM id */
1087 	ndsp->pcm_slot_rx = -1; /* current CPM slot */
1088 	ndsp->pcm_slot_tx = -1;
1089 	ndsp->pcm_bank_rx = -1;
1090 	ndsp->pcm_bank_tx = -1;
1091 	ndsp->hfc_conf = -1; /* current conference number */
1092 	/* set tone timer */
1093 	timer_setup(&ndsp->tone.tl, dsp_tone_timeout, 0);
1094 
1095 	if (dtmfthreshold < 20 || dtmfthreshold > 500)
1096 		dtmfthreshold = 200;
1097 	ndsp->dtmf.treshold = dtmfthreshold * 10000;
1098 
1099 	/* init pipeline append to list */
1100 	spin_lock_irqsave(&dsp_lock, flags);
1101 	dsp_pipeline_init(&ndsp->pipeline);
1102 	list_add_tail(&ndsp->list, &dsp_ilist);
1103 	spin_unlock_irqrestore(&dsp_lock, flags);
1104 
1105 	return 0;
1106 }
1107 
1108 
1109 static struct Bprotocol DSP = {
1110 	.Bprotocols = (1 << (ISDN_P_B_L2DSP & ISDN_P_B_MASK))
1111 	| (1 << (ISDN_P_B_L2DSPHDLC & ISDN_P_B_MASK)),
1112 	.name = "dsp",
1113 	.create = dspcreate
1114 };
1115 
1116 static int __init dsp_init(void)
1117 {
1118 	int err;
1119 	int tics;
1120 
1121 	printk(KERN_INFO "DSP module %s\n", mISDN_dsp_revision);
1122 
1123 	dsp_options = options;
1124 	dsp_debug = debug;
1125 
1126 	/* set packet size */
1127 	dsp_poll = poll;
1128 	if (dsp_poll) {
1129 		if (dsp_poll > MAX_POLL) {
1130 			printk(KERN_ERR "%s: Wrong poll value (%d), use %d "
1131 			       "maximum.\n", __func__, poll, MAX_POLL);
1132 			err = -EINVAL;
1133 			return err;
1134 		}
1135 		if (dsp_poll < 8) {
1136 			printk(KERN_ERR "%s: Wrong poll value (%d), use 8 "
1137 			       "minimum.\n", __func__, dsp_poll);
1138 			err = -EINVAL;
1139 			return err;
1140 		}
1141 		dsp_tics = poll * HZ / 8000;
1142 		if (dsp_tics * 8000 != poll * HZ) {
1143 			printk(KERN_INFO "mISDN_dsp: Cannot clock every %d "
1144 			       "samples (0,125 ms). It is not a multiple of "
1145 			       "%d HZ.\n", poll, HZ);
1146 			err = -EINVAL;
1147 			return err;
1148 		}
1149 	} else {
1150 		poll = 8;
1151 		while (poll <= MAX_POLL) {
1152 			tics = (poll * HZ) / 8000;
1153 			if (tics * 8000 == poll * HZ) {
1154 				dsp_tics = tics;
1155 				dsp_poll = poll;
1156 				if (poll >= 64)
1157 					break;
1158 			}
1159 			poll++;
1160 		}
1161 	}
1162 	if (dsp_poll == 0) {
1163 		printk(KERN_INFO "mISDN_dsp: There is no multiple of kernel "
1164 		       "clock that equals exactly the duration of 8-256 "
1165 		       "samples. (Choose kernel clock speed like 100, 250, "
1166 		       "300, 1000)\n");
1167 		err = -EINVAL;
1168 		return err;
1169 	}
1170 	printk(KERN_INFO "mISDN_dsp: DSP clocks every %d samples. This equals "
1171 	       "%d jiffies.\n", dsp_poll, dsp_tics);
1172 
1173 	/* init conversion tables */
1174 	dsp_audio_generate_law_tables();
1175 	dsp_silence = (dsp_options & DSP_OPT_ULAW) ? 0xff : 0x2a;
1176 	dsp_audio_law_to_s32 = (dsp_options & DSP_OPT_ULAW) ?
1177 		dsp_audio_ulaw_to_s32 : dsp_audio_alaw_to_s32;
1178 	dsp_audio_generate_s2law_table();
1179 	dsp_audio_generate_seven();
1180 	dsp_audio_generate_mix_table();
1181 	if (dsp_options & DSP_OPT_ULAW)
1182 		dsp_audio_generate_ulaw_samples();
1183 	dsp_audio_generate_volume_changes();
1184 
1185 	err = dsp_pipeline_module_init();
1186 	if (err) {
1187 		printk(KERN_ERR "mISDN_dsp: Can't initialize pipeline, "
1188 		       "error(%d)\n", err);
1189 		return err;
1190 	}
1191 
1192 	err = mISDN_register_Bprotocol(&DSP);
1193 	if (err) {
1194 		printk(KERN_ERR "Can't register %s error(%d)\n", DSP.name, err);
1195 		return err;
1196 	}
1197 
1198 	/* set sample timer */
1199 	timer_setup(&dsp_spl_tl, dsp_cmx_send, 0);
1200 	dsp_spl_tl.expires = jiffies + dsp_tics;
1201 	dsp_spl_jiffies = dsp_spl_tl.expires;
1202 	add_timer(&dsp_spl_tl);
1203 
1204 	return 0;
1205 }
1206 
1207 
1208 static void __exit dsp_cleanup(void)
1209 {
1210 	mISDN_unregister_Bprotocol(&DSP);
1211 
1212 	del_timer_sync(&dsp_spl_tl);
1213 
1214 	if (!list_empty(&dsp_ilist)) {
1215 		printk(KERN_ERR "mISDN_dsp: Audio DSP object inst list not "
1216 		       "empty.\n");
1217 	}
1218 	if (!list_empty(&conf_ilist)) {
1219 		printk(KERN_ERR "mISDN_dsp: Conference list not empty. Not "
1220 		       "all memory freed.\n");
1221 	}
1222 
1223 	dsp_pipeline_module_exit();
1224 }
1225 
1226 module_init(dsp_init);
1227 module_exit(dsp_cleanup);
1228