xref: /openbmc/linux/drivers/isdn/mISDN/dsp_core.c (revision 293d5b43)
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  *		For changes and modifications please read
8  *		../../../Documentation/isdn/mISDN.cert
9  *
10  * Thanks to    Karsten Keil (great drivers)
11  *              Cologne Chip (great chips)
12  *
13  * This module does:
14  *		Real-time tone generation
15  *		DTMF detection
16  *		Real-time cross-connection and conferrence
17  *		Compensate jitter due to system load and hardware fault.
18  *		All features are done in kernel space and will be realized
19  *		using hardware, if available and supported by chip set.
20  *		Blowfish encryption/decryption
21  */
22 
23 /* STRUCTURE:
24  *
25  * The dsp module provides layer 2 for b-channels (64kbit). It provides
26  * transparent audio forwarding with special digital signal processing:
27  *
28  * - (1) generation of tones
29  * - (2) detection of dtmf tones
30  * - (3) crossconnecting and conferences (clocking)
31  * - (4) echo generation for delay test
32  * - (5) volume control
33  * - (6) disable receive data
34  * - (7) pipeline
35  * - (8) encryption/decryption
36  *
37  * Look:
38  *             TX            RX
39  *         ------upper layer------
40  *             |             ^
41  *             |             |(6)
42  *             v             |
43  *       +-----+-------------+-----+
44  *       |(3)(4)                   |
45  *       |           CMX           |
46  *       |                         |
47  *       |           +-------------+
48  *       |           |       ^
49  *       |           |       |
50  *       |+---------+|  +----+----+
51  *       ||(1)      ||  |(2)      |
52  *       ||         ||  |         |
53  *       ||  Tones  ||  |  DTMF   |
54  *       ||         ||  |         |
55  *       ||         ||  |         |
56  *       |+----+----+|  +----+----+
57  *       +-----+-----+       ^
58  *             |             |
59  *             v             |
60  *        +----+----+   +----+----+
61  *        |(5)      |   |(5)      |
62  *        |         |   |         |
63  *        |TX Volume|   |RX Volume|
64  *        |         |   |         |
65  *        |         |   |         |
66  *        +----+----+   +----+----+
67  *             |             ^
68  *             |             |
69  *             v             |
70  *        +----+-------------+----+
71  *        |(7)                    |
72  *        |                       |
73  *        |  Pipeline Processing  |
74  *        |                       |
75  *        |                       |
76  *        +----+-------------+----+
77  *             |             ^
78  *             |             |
79  *             v             |
80  *        +----+----+   +----+----+
81  *        |(8)      |   |(8)      |
82  *        |         |   |         |
83  *        | Encrypt |   | Decrypt |
84  *        |         |   |         |
85  *        |         |   |         |
86  *        +----+----+   +----+----+
87  *             |             ^
88  *             |             |
89  *             v             |
90  *         ------card  layer------
91  *             TX            RX
92  *
93  * Above you can see the logical data flow. If software is used to do the
94  * process, it is actually the real data flow. If hardware is used, data
95  * may not flow, but hardware commands to the card, to provide the data flow
96  * as shown.
97  *
98  * NOTE: The channel must be activated in order to make dsp work, even if
99  * no data flow to the upper layer is intended. Activation can be done
100  * after and before controlling the setting using PH_CONTROL requests.
101  *
102  * DTMF: Will be detected by hardware if possible. It is done before CMX
103  * processing.
104  *
105  * Tones: Will be generated via software if endless looped audio fifos are
106  * not supported by hardware. Tones will override all data from CMX.
107  * It is not required to join a conference to use tones at any time.
108  *
109  * CMX: Is transparent when not used. When it is used, it will do
110  * crossconnections and conferences via software if not possible through
111  * hardware. If hardware capability is available, hardware is used.
112  *
113  * Echo: Is generated by CMX and is used to check performance of hard and
114  * software CMX.
115  *
116  * The CMX has special functions for conferences with one, two and more
117  * members. It will allow different types of data flow. Receive and transmit
118  * data to/form upper layer may be swithed on/off individually without losing
119  * features of CMX, Tones and DTMF.
120  *
121  * Echo Cancellation: Sometimes we like to cancel echo from the interface.
122  * Note that a VoIP call may not have echo caused by the IP phone. The echo
123  * is generated by the telephone line connected to it. Because the delay
124  * is high, it becomes an echo. RESULT: Echo Cachelation is required if
125  * both echo AND delay is applied to an interface.
126  * Remember that software CMX always generates a more or less delay.
127  *
128  * If all used features can be realized in hardware, and if transmit and/or
129  * receive data ist disabled, the card may not send/receive any data at all.
130  * Not receiving is useful if only announcements are played. Not sending is
131  * useful if an answering machine records audio. Not sending and receiving is
132  * useful during most states of the call. If supported by hardware, tones
133  * will be played without cpu load. Small PBXs and NT-Mode applications will
134  * not need expensive hardware when processing calls.
135  *
136  *
137  * LOCKING:
138  *
139  * When data is received from upper or lower layer (card), the complete dsp
140  * module is locked by a global lock.  This lock MUST lock irq, because it
141  * must lock timer events by DSP poll timer.
142  * When data is ready to be transmitted down, the data is queued and sent
143  * outside lock and timer event.
144  * PH_CONTROL must not change any settings, join or split conference members
145  * during process of data.
146  *
147  * HDLC:
148  *
149  * It works quite the same as transparent, except that HDLC data is forwarded
150  * to all other conference members if no hardware bridging is possible.
151  * Send data will be writte to sendq. Sendq will be sent if confirm is received.
152  * Conference cannot join, if one member is not hdlc.
153  *
154  */
155 
156 #include <linux/delay.h>
157 #include <linux/gfp.h>
158 #include <linux/mISDNif.h>
159 #include <linux/mISDNdsp.h>
160 #include <linux/module.h>
161 #include <linux/vmalloc.h>
162 #include "core.h"
163 #include "dsp.h"
164 
165 static const char *mISDN_dsp_revision = "2.0";
166 
167 static int debug;
168 static int options;
169 static int poll;
170 static int dtmfthreshold = 100;
171 
172 MODULE_AUTHOR("Andreas Eversberg");
173 module_param(debug, uint, S_IRUGO | S_IWUSR);
174 module_param(options, uint, S_IRUGO | S_IWUSR);
175 module_param(poll, uint, S_IRUGO | S_IWUSR);
176 module_param(dtmfthreshold, uint, S_IRUGO | S_IWUSR);
177 MODULE_LICENSE("GPL");
178 
179 /*int spinnest = 0;*/
180 
181 spinlock_t dsp_lock; /* global dsp lock */
182 struct list_head dsp_ilist;
183 struct list_head conf_ilist;
184 int dsp_debug;
185 int dsp_options;
186 int dsp_poll, dsp_tics;
187 
188 /* check if rx may be turned off or must be turned on */
189 static void
190 dsp_rx_off_member(struct dsp *dsp)
191 {
192 	struct mISDN_ctrl_req	cq;
193 	int rx_off = 1;
194 
195 	memset(&cq, 0, sizeof(cq));
196 
197 	if (!dsp->features_rx_off)
198 		return;
199 
200 	/* not disabled */
201 	if (!dsp->rx_disabled)
202 		rx_off = 0;
203 	/* software dtmf */
204 	else if (dsp->dtmf.software)
205 		rx_off = 0;
206 	/* echo in software */
207 	else if (dsp->echo.software)
208 		rx_off = 0;
209 	/* bridge in software */
210 	else if (dsp->conf && dsp->conf->software)
211 		rx_off = 0;
212 	/* data is not required by user space and not required
213 	 * for echo dtmf detection, soft-echo, soft-bridging */
214 
215 	if (rx_off == dsp->rx_is_off)
216 		return;
217 
218 	if (!dsp->ch.peer) {
219 		if (dsp_debug & DEBUG_DSP_CORE)
220 			printk(KERN_DEBUG "%s: no peer, no rx_off\n",
221 			       __func__);
222 		return;
223 	}
224 	cq.op = MISDN_CTRL_RX_OFF;
225 	cq.p1 = rx_off;
226 	if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
227 		printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
228 		       __func__);
229 		return;
230 	}
231 	dsp->rx_is_off = rx_off;
232 	if (dsp_debug & DEBUG_DSP_CORE)
233 		printk(KERN_DEBUG "%s: %s set rx_off = %d\n",
234 		       __func__, dsp->name, rx_off);
235 }
236 static void
237 dsp_rx_off(struct dsp *dsp)
238 {
239 	struct dsp_conf_member	*member;
240 
241 	if (dsp_options & DSP_OPT_NOHARDWARE)
242 		return;
243 
244 	/* no conf */
245 	if (!dsp->conf) {
246 		dsp_rx_off_member(dsp);
247 		return;
248 	}
249 	/* check all members in conf */
250 	list_for_each_entry(member, &dsp->conf->mlist, list) {
251 		dsp_rx_off_member(member->dsp);
252 	}
253 }
254 
255 /* enable "fill empty" feature */
256 static void
257 dsp_fill_empty(struct dsp *dsp)
258 {
259 	struct mISDN_ctrl_req	cq;
260 
261 	memset(&cq, 0, sizeof(cq));
262 
263 	if (!dsp->ch.peer) {
264 		if (dsp_debug & DEBUG_DSP_CORE)
265 			printk(KERN_DEBUG "%s: no peer, no fill_empty\n",
266 			       __func__);
267 		return;
268 	}
269 	cq.op = MISDN_CTRL_FILL_EMPTY;
270 	cq.p1 = 1;
271 	cq.p2 = dsp_silence;
272 	if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
273 		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
274 		       __func__);
275 		return;
276 	}
277 	if (dsp_debug & DEBUG_DSP_CORE)
278 		printk(KERN_DEBUG "%s: %s set fill_empty = 1\n",
279 		       __func__, dsp->name);
280 }
281 
282 static int
283 dsp_control_req(struct dsp *dsp, struct mISDNhead *hh, struct sk_buff *skb)
284 {
285 	struct sk_buff	*nskb;
286 	int ret = 0;
287 	int cont;
288 	u8 *data;
289 	int len;
290 
291 	if (skb->len < sizeof(int)) {
292 		printk(KERN_ERR "%s: PH_CONTROL message too short\n", __func__);
293 		return -EINVAL;
294 	}
295 	cont = *((int *)skb->data);
296 	len = skb->len - sizeof(int);
297 	data = skb->data + sizeof(int);
298 
299 	switch (cont) {
300 	case DTMF_TONE_START: /* turn on DTMF */
301 		if (dsp->hdlc) {
302 			ret = -EINVAL;
303 			break;
304 		}
305 		if (dsp_debug & DEBUG_DSP_CORE)
306 			printk(KERN_DEBUG "%s: start dtmf\n", __func__);
307 		if (len == sizeof(int)) {
308 			if (dsp_debug & DEBUG_DSP_CORE)
309 				printk(KERN_NOTICE "changing DTMF Threshold "
310 				       "to %d\n", *((int *)data));
311 			dsp->dtmf.treshold = (*(int *)data) * 10000;
312 		}
313 		dsp->dtmf.enable = 1;
314 		/* init goertzel */
315 		dsp_dtmf_goertzel_init(dsp);
316 
317 		/* check dtmf hardware */
318 		dsp_dtmf_hardware(dsp);
319 		dsp_rx_off(dsp);
320 		break;
321 	case DTMF_TONE_STOP: /* turn off DTMF */
322 		if (dsp_debug & DEBUG_DSP_CORE)
323 			printk(KERN_DEBUG "%s: stop dtmf\n", __func__);
324 		dsp->dtmf.enable = 0;
325 		dsp->dtmf.hardware = 0;
326 		dsp->dtmf.software = 0;
327 		break;
328 	case DSP_CONF_JOIN: /* join / update conference */
329 		if (len < sizeof(int)) {
330 			ret = -EINVAL;
331 			break;
332 		}
333 		if (*((u32 *)data) == 0)
334 			goto conf_split;
335 		if (dsp_debug & DEBUG_DSP_CORE)
336 			printk(KERN_DEBUG "%s: join conference %d\n",
337 			       __func__, *((u32 *)data));
338 		ret = dsp_cmx_conf(dsp, *((u32 *)data));
339 		/* dsp_cmx_hardware will also be called here */
340 		dsp_rx_off(dsp);
341 		if (dsp_debug & DEBUG_DSP_CMX)
342 			dsp_cmx_debug(dsp);
343 		break;
344 	case DSP_CONF_SPLIT: /* remove from conference */
345 	conf_split:
346 		if (dsp_debug & DEBUG_DSP_CORE)
347 			printk(KERN_DEBUG "%s: release conference\n", __func__);
348 		ret = dsp_cmx_conf(dsp, 0);
349 		/* dsp_cmx_hardware will also be called here */
350 		if (dsp_debug & DEBUG_DSP_CMX)
351 			dsp_cmx_debug(dsp);
352 		dsp_rx_off(dsp);
353 		break;
354 	case DSP_TONE_PATT_ON: /* play tone */
355 		if (dsp->hdlc) {
356 			ret = -EINVAL;
357 			break;
358 		}
359 		if (len < sizeof(int)) {
360 			ret = -EINVAL;
361 			break;
362 		}
363 		if (dsp_debug & DEBUG_DSP_CORE)
364 			printk(KERN_DEBUG "%s: turn tone 0x%x on\n",
365 			       __func__, *((int *)skb->data));
366 		ret = dsp_tone(dsp, *((int *)data));
367 		if (!ret) {
368 			dsp_cmx_hardware(dsp->conf, dsp);
369 			dsp_rx_off(dsp);
370 		}
371 		if (!dsp->tone.tone)
372 			goto tone_off;
373 		break;
374 	case DSP_TONE_PATT_OFF: /* stop tone */
375 		if (dsp->hdlc) {
376 			ret = -EINVAL;
377 			break;
378 		}
379 		if (dsp_debug & DEBUG_DSP_CORE)
380 			printk(KERN_DEBUG "%s: turn tone off\n", __func__);
381 		dsp_tone(dsp, 0);
382 		dsp_cmx_hardware(dsp->conf, dsp);
383 		dsp_rx_off(dsp);
384 		/* reset tx buffers (user space data) */
385 	tone_off:
386 		dsp->rx_W = 0;
387 		dsp->rx_R = 0;
388 		break;
389 	case DSP_VOL_CHANGE_TX: /* change volume */
390 		if (dsp->hdlc) {
391 			ret = -EINVAL;
392 			break;
393 		}
394 		if (len < sizeof(int)) {
395 			ret = -EINVAL;
396 			break;
397 		}
398 		dsp->tx_volume = *((int *)data);
399 		if (dsp_debug & DEBUG_DSP_CORE)
400 			printk(KERN_DEBUG "%s: change tx vol to %d\n",
401 			       __func__, dsp->tx_volume);
402 		dsp_cmx_hardware(dsp->conf, dsp);
403 		dsp_dtmf_hardware(dsp);
404 		dsp_rx_off(dsp);
405 		break;
406 	case DSP_VOL_CHANGE_RX: /* change volume */
407 		if (dsp->hdlc) {
408 			ret = -EINVAL;
409 			break;
410 		}
411 		if (len < sizeof(int)) {
412 			ret = -EINVAL;
413 			break;
414 		}
415 		dsp->rx_volume = *((int *)data);
416 		if (dsp_debug & DEBUG_DSP_CORE)
417 			printk(KERN_DEBUG "%s: change rx vol to %d\n",
418 			       __func__, dsp->tx_volume);
419 		dsp_cmx_hardware(dsp->conf, dsp);
420 		dsp_dtmf_hardware(dsp);
421 		dsp_rx_off(dsp);
422 		break;
423 	case DSP_ECHO_ON: /* enable echo */
424 		dsp->echo.software = 1; /* soft echo */
425 		if (dsp_debug & DEBUG_DSP_CORE)
426 			printk(KERN_DEBUG "%s: enable cmx-echo\n", __func__);
427 		dsp_cmx_hardware(dsp->conf, dsp);
428 		dsp_rx_off(dsp);
429 		if (dsp_debug & DEBUG_DSP_CMX)
430 			dsp_cmx_debug(dsp);
431 		break;
432 	case DSP_ECHO_OFF: /* disable echo */
433 		dsp->echo.software = 0;
434 		dsp->echo.hardware = 0;
435 		if (dsp_debug & DEBUG_DSP_CORE)
436 			printk(KERN_DEBUG "%s: disable cmx-echo\n", __func__);
437 		dsp_cmx_hardware(dsp->conf, dsp);
438 		dsp_rx_off(dsp);
439 		if (dsp_debug & DEBUG_DSP_CMX)
440 			dsp_cmx_debug(dsp);
441 		break;
442 	case DSP_RECEIVE_ON: /* enable receive to user space */
443 		if (dsp_debug & DEBUG_DSP_CORE)
444 			printk(KERN_DEBUG "%s: enable receive to user "
445 			       "space\n", __func__);
446 		dsp->rx_disabled = 0;
447 		dsp_rx_off(dsp);
448 		break;
449 	case DSP_RECEIVE_OFF: /* disable receive to user space */
450 		if (dsp_debug & DEBUG_DSP_CORE)
451 			printk(KERN_DEBUG "%s: disable receive to "
452 			       "user space\n", __func__);
453 		dsp->rx_disabled = 1;
454 		dsp_rx_off(dsp);
455 		break;
456 	case DSP_MIX_ON: /* enable mixing of tx data */
457 		if (dsp->hdlc) {
458 			ret = -EINVAL;
459 			break;
460 		}
461 		if (dsp_debug & DEBUG_DSP_CORE)
462 			printk(KERN_DEBUG "%s: enable mixing of "
463 			       "tx-data with conf members\n", __func__);
464 		dsp->tx_mix = 1;
465 		dsp_cmx_hardware(dsp->conf, dsp);
466 		dsp_rx_off(dsp);
467 		if (dsp_debug & DEBUG_DSP_CMX)
468 			dsp_cmx_debug(dsp);
469 		break;
470 	case DSP_MIX_OFF: /* disable mixing of tx data */
471 		if (dsp->hdlc) {
472 			ret = -EINVAL;
473 			break;
474 		}
475 		if (dsp_debug & DEBUG_DSP_CORE)
476 			printk(KERN_DEBUG "%s: disable mixing of "
477 			       "tx-data with conf members\n", __func__);
478 		dsp->tx_mix = 0;
479 		dsp_cmx_hardware(dsp->conf, dsp);
480 		dsp_rx_off(dsp);
481 		if (dsp_debug & DEBUG_DSP_CMX)
482 			dsp_cmx_debug(dsp);
483 		break;
484 	case DSP_TXDATA_ON: /* enable txdata */
485 		dsp->tx_data = 1;
486 		if (dsp_debug & DEBUG_DSP_CORE)
487 			printk(KERN_DEBUG "%s: enable tx-data\n", __func__);
488 		dsp_cmx_hardware(dsp->conf, dsp);
489 		dsp_rx_off(dsp);
490 		if (dsp_debug & DEBUG_DSP_CMX)
491 			dsp_cmx_debug(dsp);
492 		break;
493 	case DSP_TXDATA_OFF: /* disable txdata */
494 		dsp->tx_data = 0;
495 		if (dsp_debug & DEBUG_DSP_CORE)
496 			printk(KERN_DEBUG "%s: disable tx-data\n", __func__);
497 		dsp_cmx_hardware(dsp->conf, dsp);
498 		dsp_rx_off(dsp);
499 		if (dsp_debug & DEBUG_DSP_CMX)
500 			dsp_cmx_debug(dsp);
501 		break;
502 	case DSP_DELAY: /* use delay algorithm instead of dynamic
503 			   jitter algorithm */
504 		if (dsp->hdlc) {
505 			ret = -EINVAL;
506 			break;
507 		}
508 		if (len < sizeof(int)) {
509 			ret = -EINVAL;
510 			break;
511 		}
512 		dsp->cmx_delay = (*((int *)data)) << 3;
513 		/* milliseconds to samples */
514 		if (dsp->cmx_delay >= (CMX_BUFF_HALF >> 1))
515 			/* clip to half of maximum usable buffer
516 			   (half of half buffer) */
517 			dsp->cmx_delay = (CMX_BUFF_HALF >> 1) - 1;
518 		if (dsp_debug & DEBUG_DSP_CORE)
519 			printk(KERN_DEBUG "%s: use delay algorithm to "
520 			       "compensate jitter (%d samples)\n",
521 			       __func__, dsp->cmx_delay);
522 		break;
523 	case DSP_JITTER: /* use dynamic jitter algorithm instead of
524 			    delay algorithm */
525 		if (dsp->hdlc) {
526 			ret = -EINVAL;
527 			break;
528 		}
529 		dsp->cmx_delay = 0;
530 		if (dsp_debug & DEBUG_DSP_CORE)
531 			printk(KERN_DEBUG "%s: use jitter algorithm to "
532 			       "compensate jitter\n", __func__);
533 		break;
534 	case DSP_TX_DEJITTER: /* use dynamic jitter algorithm for tx-buffer */
535 		if (dsp->hdlc) {
536 			ret = -EINVAL;
537 			break;
538 		}
539 		dsp->tx_dejitter = 1;
540 		if (dsp_debug & DEBUG_DSP_CORE)
541 			printk(KERN_DEBUG "%s: use dejitter on TX "
542 			       "buffer\n", __func__);
543 		break;
544 	case DSP_TX_DEJ_OFF: /* use tx-buffer without dejittering*/
545 		if (dsp->hdlc) {
546 			ret = -EINVAL;
547 			break;
548 		}
549 		dsp->tx_dejitter = 0;
550 		if (dsp_debug & DEBUG_DSP_CORE)
551 			printk(KERN_DEBUG "%s: use TX buffer without "
552 			       "dejittering\n", __func__);
553 		break;
554 	case DSP_PIPELINE_CFG:
555 		if (dsp->hdlc) {
556 			ret = -EINVAL;
557 			break;
558 		}
559 		if (len > 0 && ((char *)data)[len - 1]) {
560 			printk(KERN_DEBUG "%s: pipeline config string "
561 			       "is not NULL terminated!\n", __func__);
562 			ret = -EINVAL;
563 		} else {
564 			dsp->pipeline.inuse = 1;
565 			dsp_cmx_hardware(dsp->conf, dsp);
566 			ret = dsp_pipeline_build(&dsp->pipeline,
567 						 len > 0 ? data : NULL);
568 			dsp_cmx_hardware(dsp->conf, dsp);
569 			dsp_rx_off(dsp);
570 		}
571 		break;
572 	case DSP_BF_ENABLE_KEY: /* turn blowfish on */
573 		if (dsp->hdlc) {
574 			ret = -EINVAL;
575 			break;
576 		}
577 		if (len < 4 || len > 56) {
578 			ret = -EINVAL;
579 			break;
580 		}
581 		if (dsp_debug & DEBUG_DSP_CORE)
582 			printk(KERN_DEBUG "%s: turn blowfish on (key "
583 			       "not shown)\n", __func__);
584 		ret = dsp_bf_init(dsp, (u8 *)data, len);
585 		/* set new cont */
586 		if (!ret)
587 			cont = DSP_BF_ACCEPT;
588 		else
589 			cont = DSP_BF_REJECT;
590 		/* send indication if it worked to set it */
591 		nskb = _alloc_mISDN_skb(PH_CONTROL_IND, MISDN_ID_ANY,
592 					sizeof(int), &cont, GFP_ATOMIC);
593 		if (nskb) {
594 			if (dsp->up) {
595 				if (dsp->up->send(dsp->up, nskb))
596 					dev_kfree_skb(nskb);
597 			} else
598 				dev_kfree_skb(nskb);
599 		}
600 		if (!ret) {
601 			dsp_cmx_hardware(dsp->conf, dsp);
602 			dsp_dtmf_hardware(dsp);
603 			dsp_rx_off(dsp);
604 		}
605 		break;
606 	case DSP_BF_DISABLE: /* turn blowfish off */
607 		if (dsp->hdlc) {
608 			ret = -EINVAL;
609 			break;
610 		}
611 		if (dsp_debug & DEBUG_DSP_CORE)
612 			printk(KERN_DEBUG "%s: turn blowfish off\n", __func__);
613 		dsp_bf_cleanup(dsp);
614 		dsp_cmx_hardware(dsp->conf, dsp);
615 		dsp_dtmf_hardware(dsp);
616 		dsp_rx_off(dsp);
617 		break;
618 	default:
619 		if (dsp_debug & DEBUG_DSP_CORE)
620 			printk(KERN_DEBUG "%s: ctrl req %x unhandled\n",
621 			       __func__, cont);
622 		ret = -EINVAL;
623 	}
624 	return ret;
625 }
626 
627 static void
628 get_features(struct mISDNchannel *ch)
629 {
630 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
631 	struct mISDN_ctrl_req	cq;
632 
633 	if (!ch->peer) {
634 		if (dsp_debug & DEBUG_DSP_CORE)
635 			printk(KERN_DEBUG "%s: no peer, no features\n",
636 			       __func__);
637 		return;
638 	}
639 	memset(&cq, 0, sizeof(cq));
640 	cq.op = MISDN_CTRL_GETOP;
641 	if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq) < 0) {
642 		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
643 		       __func__);
644 		return;
645 	}
646 	if (cq.op & MISDN_CTRL_RX_OFF)
647 		dsp->features_rx_off = 1;
648 	if (cq.op & MISDN_CTRL_FILL_EMPTY)
649 		dsp->features_fill_empty = 1;
650 	if (dsp_options & DSP_OPT_NOHARDWARE)
651 		return;
652 	if ((cq.op & MISDN_CTRL_HW_FEATURES_OP)) {
653 		cq.op = MISDN_CTRL_HW_FEATURES;
654 		*((u_long *)&cq.p1) = (u_long)&dsp->features;
655 		if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq)) {
656 			printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
657 			       __func__);
658 		}
659 	} else
660 		if (dsp_debug & DEBUG_DSP_CORE)
661 			printk(KERN_DEBUG "%s: features not supported for %s\n",
662 			       __func__, dsp->name);
663 }
664 
665 static int
666 dsp_function(struct mISDNchannel *ch,  struct sk_buff *skb)
667 {
668 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
669 	struct mISDNhead	*hh;
670 	int			ret = 0;
671 	u8			*digits = NULL;
672 	u_long			flags;
673 
674 	hh = mISDN_HEAD_P(skb);
675 	switch (hh->prim) {
676 		/* FROM DOWN */
677 	case (PH_DATA_CNF):
678 		dsp->data_pending = 0;
679 		/* trigger next hdlc frame, if any */
680 		if (dsp->hdlc) {
681 			spin_lock_irqsave(&dsp_lock, flags);
682 			if (dsp->b_active)
683 				schedule_work(&dsp->workq);
684 			spin_unlock_irqrestore(&dsp_lock, flags);
685 		}
686 		break;
687 	case (PH_DATA_IND):
688 	case (DL_DATA_IND):
689 		if (skb->len < 1) {
690 			ret = -EINVAL;
691 			break;
692 		}
693 		if (dsp->rx_is_off) {
694 			if (dsp_debug & DEBUG_DSP_CORE)
695 				printk(KERN_DEBUG "%s: rx-data during rx_off"
696 				       " for %s\n",
697 				       __func__, dsp->name);
698 		}
699 		if (dsp->hdlc) {
700 			/* hdlc */
701 			spin_lock_irqsave(&dsp_lock, flags);
702 			dsp_cmx_hdlc(dsp, skb);
703 			spin_unlock_irqrestore(&dsp_lock, flags);
704 			if (dsp->rx_disabled) {
705 				/* if receive is not allowed */
706 				break;
707 			}
708 			hh->prim = DL_DATA_IND;
709 			if (dsp->up)
710 				return dsp->up->send(dsp->up, skb);
711 			break;
712 		}
713 
714 		spin_lock_irqsave(&dsp_lock, flags);
715 
716 		/* decrypt if enabled */
717 		if (dsp->bf_enable)
718 			dsp_bf_decrypt(dsp, skb->data, skb->len);
719 		/* pipeline */
720 		if (dsp->pipeline.inuse)
721 			dsp_pipeline_process_rx(&dsp->pipeline, skb->data,
722 						skb->len, hh->id);
723 		/* change volume if requested */
724 		if (dsp->rx_volume)
725 			dsp_change_volume(skb, dsp->rx_volume);
726 		/* check if dtmf soft decoding is turned on */
727 		if (dsp->dtmf.software) {
728 			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
729 							  skb->len, (dsp_options & DSP_OPT_ULAW) ? 1 : 0);
730 		}
731 		/* we need to process receive data if software */
732 		if (dsp->conf && dsp->conf->software) {
733 			/* process data from card at cmx */
734 			dsp_cmx_receive(dsp, skb);
735 		}
736 
737 		spin_unlock_irqrestore(&dsp_lock, flags);
738 
739 		/* send dtmf result, if any */
740 		if (digits) {
741 			while (*digits) {
742 				int k;
743 				struct sk_buff *nskb;
744 				if (dsp_debug & DEBUG_DSP_DTMF)
745 					printk(KERN_DEBUG "%s: digit"
746 					       "(%c) to layer %s\n",
747 					       __func__, *digits, dsp->name);
748 				k = *digits | DTMF_TONE_VAL;
749 				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
750 							MISDN_ID_ANY, sizeof(int), &k,
751 							GFP_ATOMIC);
752 				if (nskb) {
753 					if (dsp->up) {
754 						if (dsp->up->send(
755 							    dsp->up, nskb))
756 							dev_kfree_skb(nskb);
757 					} else
758 						dev_kfree_skb(nskb);
759 				}
760 				digits++;
761 			}
762 		}
763 		if (dsp->rx_disabled) {
764 			/* if receive is not allowed */
765 			break;
766 		}
767 		hh->prim = DL_DATA_IND;
768 		if (dsp->up)
769 			return dsp->up->send(dsp->up, skb);
770 		break;
771 	case (PH_CONTROL_IND):
772 		if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
773 			printk(KERN_DEBUG "%s: PH_CONTROL INDICATION "
774 			       "received: %x (len %d) %s\n", __func__,
775 			       hh->id, skb->len, dsp->name);
776 		switch (hh->id) {
777 		case (DTMF_HFC_COEF): /* getting coefficients */
778 			if (!dsp->dtmf.hardware) {
779 				if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
780 					printk(KERN_DEBUG "%s: ignoring DTMF "
781 					       "coefficients from HFC\n",
782 					       __func__);
783 				break;
784 			}
785 			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
786 							  skb->len, 2);
787 			while (*digits) {
788 				int k;
789 				struct sk_buff *nskb;
790 				if (dsp_debug & DEBUG_DSP_DTMF)
791 					printk(KERN_DEBUG "%s: digit"
792 					       "(%c) to layer %s\n",
793 					       __func__, *digits, dsp->name);
794 				k = *digits | DTMF_TONE_VAL;
795 				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
796 							MISDN_ID_ANY, sizeof(int), &k,
797 							GFP_ATOMIC);
798 				if (nskb) {
799 					if (dsp->up) {
800 						if (dsp->up->send(
801 							    dsp->up, nskb))
802 							dev_kfree_skb(nskb);
803 					} else
804 						dev_kfree_skb(nskb);
805 				}
806 				digits++;
807 			}
808 			break;
809 		case (HFC_VOL_CHANGE_TX): /* change volume */
810 			if (skb->len != sizeof(int)) {
811 				ret = -EINVAL;
812 				break;
813 			}
814 			spin_lock_irqsave(&dsp_lock, flags);
815 			dsp->tx_volume = *((int *)skb->data);
816 			if (dsp_debug & DEBUG_DSP_CORE)
817 				printk(KERN_DEBUG "%s: change tx volume to "
818 				       "%d\n", __func__, dsp->tx_volume);
819 			dsp_cmx_hardware(dsp->conf, dsp);
820 			dsp_dtmf_hardware(dsp);
821 			dsp_rx_off(dsp);
822 			spin_unlock_irqrestore(&dsp_lock, flags);
823 			break;
824 		default:
825 			if (dsp_debug & DEBUG_DSP_CORE)
826 				printk(KERN_DEBUG "%s: ctrl ind %x unhandled "
827 				       "%s\n", __func__, hh->id, dsp->name);
828 			ret = -EINVAL;
829 		}
830 		break;
831 	case (PH_ACTIVATE_IND):
832 	case (PH_ACTIVATE_CNF):
833 		if (dsp_debug & DEBUG_DSP_CORE)
834 			printk(KERN_DEBUG "%s: b_channel is now active %s\n",
835 			       __func__, dsp->name);
836 		/* bchannel now active */
837 		spin_lock_irqsave(&dsp_lock, flags);
838 		dsp->b_active = 1;
839 		dsp->data_pending = 0;
840 		dsp->rx_init = 1;
841 		/* rx_W and rx_R will be adjusted on first frame */
842 		dsp->rx_W = 0;
843 		dsp->rx_R = 0;
844 		memset(dsp->rx_buff, 0, sizeof(dsp->rx_buff));
845 		dsp_cmx_hardware(dsp->conf, dsp);
846 		dsp_dtmf_hardware(dsp);
847 		dsp_rx_off(dsp);
848 		spin_unlock_irqrestore(&dsp_lock, flags);
849 		if (dsp_debug & DEBUG_DSP_CORE)
850 			printk(KERN_DEBUG "%s: done with activation, sending "
851 			       "confirm to user space. %s\n", __func__,
852 			       dsp->name);
853 		/* send activation to upper layer */
854 		hh->prim = DL_ESTABLISH_CNF;
855 		if (dsp->up)
856 			return dsp->up->send(dsp->up, skb);
857 		break;
858 	case (PH_DEACTIVATE_IND):
859 	case (PH_DEACTIVATE_CNF):
860 		if (dsp_debug & DEBUG_DSP_CORE)
861 			printk(KERN_DEBUG "%s: b_channel is now inactive %s\n",
862 			       __func__, dsp->name);
863 		/* bchannel now inactive */
864 		spin_lock_irqsave(&dsp_lock, flags);
865 		dsp->b_active = 0;
866 		dsp->data_pending = 0;
867 		dsp_cmx_hardware(dsp->conf, dsp);
868 		dsp_rx_off(dsp);
869 		spin_unlock_irqrestore(&dsp_lock, flags);
870 		hh->prim = DL_RELEASE_CNF;
871 		if (dsp->up)
872 			return dsp->up->send(dsp->up, skb);
873 		break;
874 		/* FROM UP */
875 	case (DL_DATA_REQ):
876 	case (PH_DATA_REQ):
877 		if (skb->len < 1) {
878 			ret = -EINVAL;
879 			break;
880 		}
881 		if (dsp->hdlc) {
882 			/* hdlc */
883 			if (!dsp->b_active) {
884 				ret = -EIO;
885 				break;
886 			}
887 			hh->prim = PH_DATA_REQ;
888 			spin_lock_irqsave(&dsp_lock, flags);
889 			skb_queue_tail(&dsp->sendq, skb);
890 			schedule_work(&dsp->workq);
891 			spin_unlock_irqrestore(&dsp_lock, flags);
892 			return 0;
893 		}
894 		/* send data to tx-buffer (if no tone is played) */
895 		if (!dsp->tone.tone) {
896 			spin_lock_irqsave(&dsp_lock, flags);
897 			dsp_cmx_transmit(dsp, skb);
898 			spin_unlock_irqrestore(&dsp_lock, flags);
899 		}
900 		break;
901 	case (PH_CONTROL_REQ):
902 		spin_lock_irqsave(&dsp_lock, flags);
903 		ret = dsp_control_req(dsp, hh, skb);
904 		spin_unlock_irqrestore(&dsp_lock, flags);
905 		break;
906 	case (DL_ESTABLISH_REQ):
907 	case (PH_ACTIVATE_REQ):
908 		if (dsp_debug & DEBUG_DSP_CORE)
909 			printk(KERN_DEBUG "%s: activating b_channel %s\n",
910 			       __func__, dsp->name);
911 		if (dsp->dtmf.hardware || dsp->dtmf.software)
912 			dsp_dtmf_goertzel_init(dsp);
913 		get_features(ch);
914 		/* enable fill_empty feature */
915 		if (dsp->features_fill_empty)
916 			dsp_fill_empty(dsp);
917 		/* send ph_activate */
918 		hh->prim = PH_ACTIVATE_REQ;
919 		if (ch->peer)
920 			return ch->recv(ch->peer, skb);
921 		break;
922 	case (DL_RELEASE_REQ):
923 	case (PH_DEACTIVATE_REQ):
924 		if (dsp_debug & DEBUG_DSP_CORE)
925 			printk(KERN_DEBUG "%s: releasing b_channel %s\n",
926 			       __func__, dsp->name);
927 		spin_lock_irqsave(&dsp_lock, flags);
928 		dsp->tone.tone = 0;
929 		dsp->tone.hardware = 0;
930 		dsp->tone.software = 0;
931 		if (timer_pending(&dsp->tone.tl))
932 			del_timer(&dsp->tone.tl);
933 		if (dsp->conf)
934 			dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be
935 						 called here */
936 		skb_queue_purge(&dsp->sendq);
937 		spin_unlock_irqrestore(&dsp_lock, flags);
938 		hh->prim = PH_DEACTIVATE_REQ;
939 		if (ch->peer)
940 			return ch->recv(ch->peer, skb);
941 		break;
942 	default:
943 		if (dsp_debug & DEBUG_DSP_CORE)
944 			printk(KERN_DEBUG "%s: msg %x unhandled %s\n",
945 			       __func__, hh->prim, dsp->name);
946 		ret = -EINVAL;
947 	}
948 	if (!ret)
949 		dev_kfree_skb(skb);
950 	return ret;
951 }
952 
953 static int
954 dsp_ctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
955 {
956 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
957 	u_long		flags;
958 	int		err = 0;
959 
960 	if (debug & DEBUG_DSP_CTRL)
961 		printk(KERN_DEBUG "%s:(%x)\n", __func__, cmd);
962 
963 	switch (cmd) {
964 	case OPEN_CHANNEL:
965 		break;
966 	case CLOSE_CHANNEL:
967 		if (dsp->ch.peer)
968 			dsp->ch.peer->ctrl(dsp->ch.peer, CLOSE_CHANNEL, NULL);
969 
970 		/* wait until workqueue has finished,
971 		 * must lock here, or we may hit send-process currently
972 		 * queueing. */
973 		spin_lock_irqsave(&dsp_lock, flags);
974 		dsp->b_active = 0;
975 		spin_unlock_irqrestore(&dsp_lock, flags);
976 		/* MUST not be locked, because it waits until queue is done. */
977 		cancel_work_sync(&dsp->workq);
978 		spin_lock_irqsave(&dsp_lock, flags);
979 		if (timer_pending(&dsp->tone.tl))
980 			del_timer(&dsp->tone.tl);
981 		skb_queue_purge(&dsp->sendq);
982 		if (dsp_debug & DEBUG_DSP_CTRL)
983 			printk(KERN_DEBUG "%s: releasing member %s\n",
984 			       __func__, dsp->name);
985 		dsp->b_active = 0;
986 		dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be called
987 					 here */
988 		dsp_pipeline_destroy(&dsp->pipeline);
989 
990 		if (dsp_debug & DEBUG_DSP_CTRL)
991 			printk(KERN_DEBUG "%s: remove & destroy object %s\n",
992 			       __func__, dsp->name);
993 		list_del(&dsp->list);
994 		spin_unlock_irqrestore(&dsp_lock, flags);
995 
996 		if (dsp_debug & DEBUG_DSP_CTRL)
997 			printk(KERN_DEBUG "%s: dsp instance released\n",
998 			       __func__);
999 		vfree(dsp);
1000 		module_put(THIS_MODULE);
1001 		break;
1002 	}
1003 	return err;
1004 }
1005 
1006 static void
1007 dsp_send_bh(struct work_struct *work)
1008 {
1009 	struct dsp *dsp = container_of(work, struct dsp, workq);
1010 	struct sk_buff *skb;
1011 	struct mISDNhead	*hh;
1012 
1013 	if (dsp->hdlc && dsp->data_pending)
1014 		return; /* wait until data has been acknowledged */
1015 
1016 	/* send queued data */
1017 	while ((skb = skb_dequeue(&dsp->sendq))) {
1018 		/* in locked date, we must have still data in queue */
1019 		if (dsp->data_pending) {
1020 			if (dsp_debug & DEBUG_DSP_CORE)
1021 				printk(KERN_DEBUG "%s: fifo full %s, this is "
1022 				       "no bug!\n", __func__, dsp->name);
1023 			/* flush transparent data, if not acked */
1024 			dev_kfree_skb(skb);
1025 			continue;
1026 		}
1027 		hh = mISDN_HEAD_P(skb);
1028 		if (hh->prim == DL_DATA_REQ) {
1029 			/* send packet up */
1030 			if (dsp->up) {
1031 				if (dsp->up->send(dsp->up, skb))
1032 					dev_kfree_skb(skb);
1033 			} else
1034 				dev_kfree_skb(skb);
1035 		} else {
1036 			/* send packet down */
1037 			if (dsp->ch.peer) {
1038 				dsp->data_pending = 1;
1039 				if (dsp->ch.recv(dsp->ch.peer, skb)) {
1040 					dev_kfree_skb(skb);
1041 					dsp->data_pending = 0;
1042 				}
1043 			} else
1044 				dev_kfree_skb(skb);
1045 		}
1046 	}
1047 }
1048 
1049 static int
1050 dspcreate(struct channel_req *crq)
1051 {
1052 	struct dsp		*ndsp;
1053 	u_long		flags;
1054 
1055 	if (crq->protocol != ISDN_P_B_L2DSP
1056 	    && crq->protocol != ISDN_P_B_L2DSPHDLC)
1057 		return -EPROTONOSUPPORT;
1058 	ndsp = vzalloc(sizeof(struct dsp));
1059 	if (!ndsp) {
1060 		printk(KERN_ERR "%s: vmalloc struct dsp failed\n", __func__);
1061 		return -ENOMEM;
1062 	}
1063 	if (dsp_debug & DEBUG_DSP_CTRL)
1064 		printk(KERN_DEBUG "%s: creating new dsp instance\n", __func__);
1065 
1066 	/* default enabled */
1067 	INIT_WORK(&ndsp->workq, (void *)dsp_send_bh);
1068 	skb_queue_head_init(&ndsp->sendq);
1069 	ndsp->ch.send = dsp_function;
1070 	ndsp->ch.ctrl = dsp_ctrl;
1071 	ndsp->up = crq->ch;
1072 	crq->ch = &ndsp->ch;
1073 	if (crq->protocol == ISDN_P_B_L2DSP) {
1074 		crq->protocol = ISDN_P_B_RAW;
1075 		ndsp->hdlc = 0;
1076 	} else {
1077 		crq->protocol = ISDN_P_B_HDLC;
1078 		ndsp->hdlc = 1;
1079 	}
1080 	if (!try_module_get(THIS_MODULE))
1081 		printk(KERN_WARNING "%s:cannot get module\n",
1082 		       __func__);
1083 
1084 	sprintf(ndsp->name, "DSP_C%x(0x%p)",
1085 		ndsp->up->st->dev->id + 1, ndsp);
1086 	/* set frame size to start */
1087 	ndsp->features.hfc_id = -1; /* current PCM id */
1088 	ndsp->features.pcm_id = -1; /* current PCM id */
1089 	ndsp->pcm_slot_rx = -1; /* current CPM slot */
1090 	ndsp->pcm_slot_tx = -1;
1091 	ndsp->pcm_bank_rx = -1;
1092 	ndsp->pcm_bank_tx = -1;
1093 	ndsp->hfc_conf = -1; /* current conference number */
1094 	/* set tone timer */
1095 	ndsp->tone.tl.function = (void *)dsp_tone_timeout;
1096 	ndsp->tone.tl.data = (long) ndsp;
1097 	init_timer(&ndsp->tone.tl);
1098 
1099 	if (dtmfthreshold < 20 || dtmfthreshold > 500)
1100 		dtmfthreshold = 200;
1101 	ndsp->dtmf.treshold = dtmfthreshold * 10000;
1102 
1103 	/* init pipeline append to list */
1104 	spin_lock_irqsave(&dsp_lock, flags);
1105 	dsp_pipeline_init(&ndsp->pipeline);
1106 	list_add_tail(&ndsp->list, &dsp_ilist);
1107 	spin_unlock_irqrestore(&dsp_lock, flags);
1108 
1109 	return 0;
1110 }
1111 
1112 
1113 static struct Bprotocol DSP = {
1114 	.Bprotocols = (1 << (ISDN_P_B_L2DSP & ISDN_P_B_MASK))
1115 	| (1 << (ISDN_P_B_L2DSPHDLC & ISDN_P_B_MASK)),
1116 	.name = "dsp",
1117 	.create = dspcreate
1118 };
1119 
1120 static int __init dsp_init(void)
1121 {
1122 	int err;
1123 	int tics;
1124 
1125 	printk(KERN_INFO "DSP module %s\n", mISDN_dsp_revision);
1126 
1127 	dsp_options = options;
1128 	dsp_debug = debug;
1129 
1130 	/* set packet size */
1131 	dsp_poll = poll;
1132 	if (dsp_poll) {
1133 		if (dsp_poll > MAX_POLL) {
1134 			printk(KERN_ERR "%s: Wrong poll value (%d), use %d "
1135 			       "maximum.\n", __func__, poll, MAX_POLL);
1136 			err = -EINVAL;
1137 			return err;
1138 		}
1139 		if (dsp_poll < 8) {
1140 			printk(KERN_ERR "%s: Wrong poll value (%d), use 8 "
1141 			       "minimum.\n", __func__, dsp_poll);
1142 			err = -EINVAL;
1143 			return err;
1144 		}
1145 		dsp_tics = poll * HZ / 8000;
1146 		if (dsp_tics * 8000 != poll * HZ) {
1147 			printk(KERN_INFO "mISDN_dsp: Cannot clock every %d "
1148 			       "samples (0,125 ms). It is not a multiple of "
1149 			       "%d HZ.\n", poll, HZ);
1150 			err = -EINVAL;
1151 			return err;
1152 		}
1153 	} else {
1154 		poll = 8;
1155 		while (poll <= MAX_POLL) {
1156 			tics = (poll * HZ) / 8000;
1157 			if (tics * 8000 == poll * HZ) {
1158 				dsp_tics = tics;
1159 				dsp_poll = poll;
1160 				if (poll >= 64)
1161 					break;
1162 			}
1163 			poll++;
1164 		}
1165 	}
1166 	if (dsp_poll == 0) {
1167 		printk(KERN_INFO "mISDN_dsp: There is no multiple of kernel "
1168 		       "clock that equals exactly the duration of 8-256 "
1169 		       "samples. (Choose kernel clock speed like 100, 250, "
1170 		       "300, 1000)\n");
1171 		err = -EINVAL;
1172 		return err;
1173 	}
1174 	printk(KERN_INFO "mISDN_dsp: DSP clocks every %d samples. This equals "
1175 	       "%d jiffies.\n", dsp_poll, dsp_tics);
1176 
1177 	spin_lock_init(&dsp_lock);
1178 	INIT_LIST_HEAD(&dsp_ilist);
1179 	INIT_LIST_HEAD(&conf_ilist);
1180 
1181 	/* init conversion tables */
1182 	dsp_audio_generate_law_tables();
1183 	dsp_silence = (dsp_options & DSP_OPT_ULAW) ? 0xff : 0x2a;
1184 	dsp_audio_law_to_s32 = (dsp_options & DSP_OPT_ULAW) ?
1185 		dsp_audio_ulaw_to_s32 : dsp_audio_alaw_to_s32;
1186 	dsp_audio_generate_s2law_table();
1187 	dsp_audio_generate_seven();
1188 	dsp_audio_generate_mix_table();
1189 	if (dsp_options & DSP_OPT_ULAW)
1190 		dsp_audio_generate_ulaw_samples();
1191 	dsp_audio_generate_volume_changes();
1192 
1193 	err = dsp_pipeline_module_init();
1194 	if (err) {
1195 		printk(KERN_ERR "mISDN_dsp: Can't initialize pipeline, "
1196 		       "error(%d)\n", err);
1197 		return err;
1198 	}
1199 
1200 	err = mISDN_register_Bprotocol(&DSP);
1201 	if (err) {
1202 		printk(KERN_ERR "Can't register %s error(%d)\n", DSP.name, err);
1203 		return err;
1204 	}
1205 
1206 	/* set sample timer */
1207 	dsp_spl_tl.function = (void *)dsp_cmx_send;
1208 	dsp_spl_tl.data = 0;
1209 	init_timer(&dsp_spl_tl);
1210 	dsp_spl_tl.expires = jiffies + dsp_tics;
1211 	dsp_spl_jiffies = dsp_spl_tl.expires;
1212 	add_timer(&dsp_spl_tl);
1213 
1214 	return 0;
1215 }
1216 
1217 
1218 static void __exit dsp_cleanup(void)
1219 {
1220 	mISDN_unregister_Bprotocol(&DSP);
1221 
1222 	del_timer_sync(&dsp_spl_tl);
1223 
1224 	if (!list_empty(&dsp_ilist)) {
1225 		printk(KERN_ERR "mISDN_dsp: Audio DSP object inst list not "
1226 		       "empty.\n");
1227 	}
1228 	if (!list_empty(&conf_ilist)) {
1229 		printk(KERN_ERR "mISDN_dsp: Conference list not empty. Not "
1230 		       "all memory freed.\n");
1231 	}
1232 
1233 	dsp_pipeline_module_exit();
1234 }
1235 
1236 module_init(dsp_init);
1237 module_exit(dsp_cleanup);
1238