xref: /linux/drivers/isdn/mISDN/dsp_core.c (revision f4738f56d1dc62aaba69b33702a5ab098f1b8c63)
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_LICENSE("GPL");
176 
177 /*int spinnest = 0;*/
178 
179 DEFINE_SPINLOCK(dsp_lock); /* global dsp lock */
180 LIST_HEAD(dsp_ilist);
181 LIST_HEAD(conf_ilist);
182 int dsp_debug;
183 int dsp_options;
184 int dsp_poll, dsp_tics;
185 
186 /* check if rx may be turned off or must be turned on */
187 static void
188 dsp_rx_off_member(struct dsp *dsp)
189 {
190 	struct mISDN_ctrl_req	cq;
191 	int rx_off = 1;
192 
193 	memset(&cq, 0, sizeof(cq));
194 
195 	if (!dsp->features_rx_off)
196 		return;
197 
198 	/* not disabled */
199 	if (!dsp->rx_disabled)
200 		rx_off = 0;
201 	/* software dtmf */
202 	else if (dsp->dtmf.software)
203 		rx_off = 0;
204 	/* echo in software */
205 	else if (dsp->echo.software)
206 		rx_off = 0;
207 	/* bridge in software */
208 	else if (dsp->conf && dsp->conf->software)
209 		rx_off = 0;
210 	/* data is not required by user space and not required
211 	 * for echo dtmf detection, soft-echo, soft-bridging */
212 
213 	if (rx_off == dsp->rx_is_off)
214 		return;
215 
216 	if (!dsp->ch.peer) {
217 		if (dsp_debug & DEBUG_DSP_CORE)
218 			printk(KERN_DEBUG "%s: no peer, no rx_off\n",
219 			       __func__);
220 		return;
221 	}
222 	cq.op = MISDN_CTRL_RX_OFF;
223 	cq.p1 = rx_off;
224 	if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
225 		printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
226 		       __func__);
227 		return;
228 	}
229 	dsp->rx_is_off = rx_off;
230 	if (dsp_debug & DEBUG_DSP_CORE)
231 		printk(KERN_DEBUG "%s: %s set rx_off = %d\n",
232 		       __func__, dsp->name, rx_off);
233 }
234 static void
235 dsp_rx_off(struct dsp *dsp)
236 {
237 	struct dsp_conf_member	*member;
238 
239 	if (dsp_options & DSP_OPT_NOHARDWARE)
240 		return;
241 
242 	/* no conf */
243 	if (!dsp->conf) {
244 		dsp_rx_off_member(dsp);
245 		return;
246 	}
247 	/* check all members in conf */
248 	list_for_each_entry(member, &dsp->conf->mlist, list) {
249 		dsp_rx_off_member(member->dsp);
250 	}
251 }
252 
253 /* enable "fill empty" feature */
254 static void
255 dsp_fill_empty(struct dsp *dsp)
256 {
257 	struct mISDN_ctrl_req	cq;
258 
259 	memset(&cq, 0, sizeof(cq));
260 
261 	if (!dsp->ch.peer) {
262 		if (dsp_debug & DEBUG_DSP_CORE)
263 			printk(KERN_DEBUG "%s: no peer, no fill_empty\n",
264 			       __func__);
265 		return;
266 	}
267 	cq.op = MISDN_CTRL_FILL_EMPTY;
268 	cq.p1 = 1;
269 	cq.p2 = dsp_silence;
270 	if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
271 		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
272 		       __func__);
273 		return;
274 	}
275 	if (dsp_debug & DEBUG_DSP_CORE)
276 		printk(KERN_DEBUG "%s: %s set fill_empty = 1\n",
277 		       __func__, dsp->name);
278 }
279 
280 static int
281 dsp_control_req(struct dsp *dsp, struct mISDNhead *hh, struct sk_buff *skb)
282 {
283 	struct sk_buff	*nskb;
284 	int ret = 0;
285 	int cont;
286 	u8 *data;
287 	int len;
288 
289 	if (skb->len < sizeof(int)) {
290 		printk(KERN_ERR "%s: PH_CONTROL message too short\n", __func__);
291 		return -EINVAL;
292 	}
293 	cont = *((int *)skb->data);
294 	len = skb->len - sizeof(int);
295 	data = skb->data + sizeof(int);
296 
297 	switch (cont) {
298 	case DTMF_TONE_START: /* turn on DTMF */
299 		if (dsp->hdlc) {
300 			ret = -EINVAL;
301 			break;
302 		}
303 		if (dsp_debug & DEBUG_DSP_CORE)
304 			printk(KERN_DEBUG "%s: start dtmf\n", __func__);
305 		if (len == sizeof(int)) {
306 			if (dsp_debug & DEBUG_DSP_CORE)
307 				printk(KERN_NOTICE "changing DTMF Threshold "
308 				       "to %d\n", *((int *)data));
309 			dsp->dtmf.treshold = (*(int *)data) * 10000;
310 		}
311 		dsp->dtmf.enable = 1;
312 		/* init goertzel */
313 		dsp_dtmf_goertzel_init(dsp);
314 
315 		/* check dtmf hardware */
316 		dsp_dtmf_hardware(dsp);
317 		dsp_rx_off(dsp);
318 		break;
319 	case DTMF_TONE_STOP: /* turn off DTMF */
320 		if (dsp_debug & DEBUG_DSP_CORE)
321 			printk(KERN_DEBUG "%s: stop dtmf\n", __func__);
322 		dsp->dtmf.enable = 0;
323 		dsp->dtmf.hardware = 0;
324 		dsp->dtmf.software = 0;
325 		break;
326 	case DSP_CONF_JOIN: /* join / update conference */
327 		if (len < sizeof(int)) {
328 			ret = -EINVAL;
329 			break;
330 		}
331 		if (*((u32 *)data) == 0)
332 			goto conf_split;
333 		if (dsp_debug & DEBUG_DSP_CORE)
334 			printk(KERN_DEBUG "%s: join conference %d\n",
335 			       __func__, *((u32 *)data));
336 		ret = dsp_cmx_conf(dsp, *((u32 *)data));
337 		/* dsp_cmx_hardware will also be called here */
338 		dsp_rx_off(dsp);
339 		if (dsp_debug & DEBUG_DSP_CMX)
340 			dsp_cmx_debug(dsp);
341 		break;
342 	case DSP_CONF_SPLIT: /* remove from conference */
343 	conf_split:
344 		if (dsp_debug & DEBUG_DSP_CORE)
345 			printk(KERN_DEBUG "%s: release conference\n", __func__);
346 		ret = dsp_cmx_conf(dsp, 0);
347 		/* dsp_cmx_hardware will also be called here */
348 		if (dsp_debug & DEBUG_DSP_CMX)
349 			dsp_cmx_debug(dsp);
350 		dsp_rx_off(dsp);
351 		break;
352 	case DSP_TONE_PATT_ON: /* play tone */
353 		if (dsp->hdlc) {
354 			ret = -EINVAL;
355 			break;
356 		}
357 		if (len < sizeof(int)) {
358 			ret = -EINVAL;
359 			break;
360 		}
361 		if (dsp_debug & DEBUG_DSP_CORE)
362 			printk(KERN_DEBUG "%s: turn tone 0x%x on\n",
363 			       __func__, *((int *)skb->data));
364 		ret = dsp_tone(dsp, *((int *)data));
365 		if (!ret) {
366 			dsp_cmx_hardware(dsp->conf, dsp);
367 			dsp_rx_off(dsp);
368 		}
369 		if (!dsp->tone.tone)
370 			goto tone_off;
371 		break;
372 	case DSP_TONE_PATT_OFF: /* stop tone */
373 		if (dsp->hdlc) {
374 			ret = -EINVAL;
375 			break;
376 		}
377 		if (dsp_debug & DEBUG_DSP_CORE)
378 			printk(KERN_DEBUG "%s: turn tone off\n", __func__);
379 		dsp_tone(dsp, 0);
380 		dsp_cmx_hardware(dsp->conf, dsp);
381 		dsp_rx_off(dsp);
382 		/* reset tx buffers (user space data) */
383 	tone_off:
384 		dsp->rx_W = 0;
385 		dsp->rx_R = 0;
386 		break;
387 	case DSP_VOL_CHANGE_TX: /* change volume */
388 		if (dsp->hdlc) {
389 			ret = -EINVAL;
390 			break;
391 		}
392 		if (len < sizeof(int)) {
393 			ret = -EINVAL;
394 			break;
395 		}
396 		dsp->tx_volume = *((int *)data);
397 		if (dsp_debug & DEBUG_DSP_CORE)
398 			printk(KERN_DEBUG "%s: change tx vol to %d\n",
399 			       __func__, dsp->tx_volume);
400 		dsp_cmx_hardware(dsp->conf, dsp);
401 		dsp_dtmf_hardware(dsp);
402 		dsp_rx_off(dsp);
403 		break;
404 	case DSP_VOL_CHANGE_RX: /* change volume */
405 		if (dsp->hdlc) {
406 			ret = -EINVAL;
407 			break;
408 		}
409 		if (len < sizeof(int)) {
410 			ret = -EINVAL;
411 			break;
412 		}
413 		dsp->rx_volume = *((int *)data);
414 		if (dsp_debug & DEBUG_DSP_CORE)
415 			printk(KERN_DEBUG "%s: change rx vol to %d\n",
416 			       __func__, dsp->tx_volume);
417 		dsp_cmx_hardware(dsp->conf, dsp);
418 		dsp_dtmf_hardware(dsp);
419 		dsp_rx_off(dsp);
420 		break;
421 	case DSP_ECHO_ON: /* enable echo */
422 		dsp->echo.software = 1; /* soft echo */
423 		if (dsp_debug & DEBUG_DSP_CORE)
424 			printk(KERN_DEBUG "%s: enable cmx-echo\n", __func__);
425 		dsp_cmx_hardware(dsp->conf, dsp);
426 		dsp_rx_off(dsp);
427 		if (dsp_debug & DEBUG_DSP_CMX)
428 			dsp_cmx_debug(dsp);
429 		break;
430 	case DSP_ECHO_OFF: /* disable echo */
431 		dsp->echo.software = 0;
432 		dsp->echo.hardware = 0;
433 		if (dsp_debug & DEBUG_DSP_CORE)
434 			printk(KERN_DEBUG "%s: disable cmx-echo\n", __func__);
435 		dsp_cmx_hardware(dsp->conf, dsp);
436 		dsp_rx_off(dsp);
437 		if (dsp_debug & DEBUG_DSP_CMX)
438 			dsp_cmx_debug(dsp);
439 		break;
440 	case DSP_RECEIVE_ON: /* enable receive to user space */
441 		if (dsp_debug & DEBUG_DSP_CORE)
442 			printk(KERN_DEBUG "%s: enable receive to user "
443 			       "space\n", __func__);
444 		dsp->rx_disabled = 0;
445 		dsp_rx_off(dsp);
446 		break;
447 	case DSP_RECEIVE_OFF: /* disable receive to user space */
448 		if (dsp_debug & DEBUG_DSP_CORE)
449 			printk(KERN_DEBUG "%s: disable receive to "
450 			       "user space\n", __func__);
451 		dsp->rx_disabled = 1;
452 		dsp_rx_off(dsp);
453 		break;
454 	case DSP_MIX_ON: /* enable mixing of tx data */
455 		if (dsp->hdlc) {
456 			ret = -EINVAL;
457 			break;
458 		}
459 		if (dsp_debug & DEBUG_DSP_CORE)
460 			printk(KERN_DEBUG "%s: enable mixing of "
461 			       "tx-data with conf members\n", __func__);
462 		dsp->tx_mix = 1;
463 		dsp_cmx_hardware(dsp->conf, dsp);
464 		dsp_rx_off(dsp);
465 		if (dsp_debug & DEBUG_DSP_CMX)
466 			dsp_cmx_debug(dsp);
467 		break;
468 	case DSP_MIX_OFF: /* disable mixing of tx data */
469 		if (dsp->hdlc) {
470 			ret = -EINVAL;
471 			break;
472 		}
473 		if (dsp_debug & DEBUG_DSP_CORE)
474 			printk(KERN_DEBUG "%s: disable mixing of "
475 			       "tx-data with conf members\n", __func__);
476 		dsp->tx_mix = 0;
477 		dsp_cmx_hardware(dsp->conf, dsp);
478 		dsp_rx_off(dsp);
479 		if (dsp_debug & DEBUG_DSP_CMX)
480 			dsp_cmx_debug(dsp);
481 		break;
482 	case DSP_TXDATA_ON: /* enable txdata */
483 		dsp->tx_data = 1;
484 		if (dsp_debug & DEBUG_DSP_CORE)
485 			printk(KERN_DEBUG "%s: enable tx-data\n", __func__);
486 		dsp_cmx_hardware(dsp->conf, dsp);
487 		dsp_rx_off(dsp);
488 		if (dsp_debug & DEBUG_DSP_CMX)
489 			dsp_cmx_debug(dsp);
490 		break;
491 	case DSP_TXDATA_OFF: /* disable txdata */
492 		dsp->tx_data = 0;
493 		if (dsp_debug & DEBUG_DSP_CORE)
494 			printk(KERN_DEBUG "%s: disable tx-data\n", __func__);
495 		dsp_cmx_hardware(dsp->conf, dsp);
496 		dsp_rx_off(dsp);
497 		if (dsp_debug & DEBUG_DSP_CMX)
498 			dsp_cmx_debug(dsp);
499 		break;
500 	case DSP_DELAY: /* use delay algorithm instead of dynamic
501 			   jitter algorithm */
502 		if (dsp->hdlc) {
503 			ret = -EINVAL;
504 			break;
505 		}
506 		if (len < sizeof(int)) {
507 			ret = -EINVAL;
508 			break;
509 		}
510 		dsp->cmx_delay = (*((int *)data)) << 3;
511 		/* milliseconds to samples */
512 		if (dsp->cmx_delay >= (CMX_BUFF_HALF >> 1))
513 			/* clip to half of maximum usable buffer
514 			   (half of half buffer) */
515 			dsp->cmx_delay = (CMX_BUFF_HALF >> 1) - 1;
516 		if (dsp_debug & DEBUG_DSP_CORE)
517 			printk(KERN_DEBUG "%s: use delay algorithm to "
518 			       "compensate jitter (%d samples)\n",
519 			       __func__, dsp->cmx_delay);
520 		break;
521 	case DSP_JITTER: /* use dynamic jitter algorithm instead of
522 			    delay algorithm */
523 		if (dsp->hdlc) {
524 			ret = -EINVAL;
525 			break;
526 		}
527 		dsp->cmx_delay = 0;
528 		if (dsp_debug & DEBUG_DSP_CORE)
529 			printk(KERN_DEBUG "%s: use jitter algorithm to "
530 			       "compensate jitter\n", __func__);
531 		break;
532 	case DSP_TX_DEJITTER: /* use dynamic jitter algorithm for tx-buffer */
533 		if (dsp->hdlc) {
534 			ret = -EINVAL;
535 			break;
536 		}
537 		dsp->tx_dejitter = 1;
538 		if (dsp_debug & DEBUG_DSP_CORE)
539 			printk(KERN_DEBUG "%s: use dejitter on TX "
540 			       "buffer\n", __func__);
541 		break;
542 	case DSP_TX_DEJ_OFF: /* use tx-buffer without dejittering*/
543 		if (dsp->hdlc) {
544 			ret = -EINVAL;
545 			break;
546 		}
547 		dsp->tx_dejitter = 0;
548 		if (dsp_debug & DEBUG_DSP_CORE)
549 			printk(KERN_DEBUG "%s: use TX buffer without "
550 			       "dejittering\n", __func__);
551 		break;
552 	case DSP_PIPELINE_CFG:
553 		if (dsp->hdlc) {
554 			ret = -EINVAL;
555 			break;
556 		}
557 		if (len > 0 && ((char *)data)[len - 1]) {
558 			printk(KERN_DEBUG "%s: pipeline config string "
559 			       "is not NULL terminated!\n", __func__);
560 			ret = -EINVAL;
561 		} else {
562 			dsp->pipeline.inuse = 1;
563 			dsp_cmx_hardware(dsp->conf, dsp);
564 			ret = dsp_pipeline_build(&dsp->pipeline,
565 						 len > 0 ? data : NULL);
566 			dsp_cmx_hardware(dsp->conf, dsp);
567 			dsp_rx_off(dsp);
568 		}
569 		break;
570 	case DSP_BF_ENABLE_KEY: /* turn blowfish on */
571 		if (dsp->hdlc) {
572 			ret = -EINVAL;
573 			break;
574 		}
575 		if (len < 4 || len > 56) {
576 			ret = -EINVAL;
577 			break;
578 		}
579 		if (dsp_debug & DEBUG_DSP_CORE)
580 			printk(KERN_DEBUG "%s: turn blowfish on (key "
581 			       "not shown)\n", __func__);
582 		ret = dsp_bf_init(dsp, (u8 *)data, len);
583 		/* set new cont */
584 		if (!ret)
585 			cont = DSP_BF_ACCEPT;
586 		else
587 			cont = DSP_BF_REJECT;
588 		/* send indication if it worked to set it */
589 		nskb = _alloc_mISDN_skb(PH_CONTROL_IND, MISDN_ID_ANY,
590 					sizeof(int), &cont, GFP_ATOMIC);
591 		if (nskb) {
592 			if (dsp->up) {
593 				if (dsp->up->send(dsp->up, nskb))
594 					dev_kfree_skb(nskb);
595 			} else
596 				dev_kfree_skb(nskb);
597 		}
598 		if (!ret) {
599 			dsp_cmx_hardware(dsp->conf, dsp);
600 			dsp_dtmf_hardware(dsp);
601 			dsp_rx_off(dsp);
602 		}
603 		break;
604 	case DSP_BF_DISABLE: /* turn blowfish off */
605 		if (dsp->hdlc) {
606 			ret = -EINVAL;
607 			break;
608 		}
609 		if (dsp_debug & DEBUG_DSP_CORE)
610 			printk(KERN_DEBUG "%s: turn blowfish off\n", __func__);
611 		dsp_bf_cleanup(dsp);
612 		dsp_cmx_hardware(dsp->conf, dsp);
613 		dsp_dtmf_hardware(dsp);
614 		dsp_rx_off(dsp);
615 		break;
616 	default:
617 		if (dsp_debug & DEBUG_DSP_CORE)
618 			printk(KERN_DEBUG "%s: ctrl req %x unhandled\n",
619 			       __func__, cont);
620 		ret = -EINVAL;
621 	}
622 	return ret;
623 }
624 
625 static void
626 get_features(struct mISDNchannel *ch)
627 {
628 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
629 	struct mISDN_ctrl_req	cq;
630 
631 	if (!ch->peer) {
632 		if (dsp_debug & DEBUG_DSP_CORE)
633 			printk(KERN_DEBUG "%s: no peer, no features\n",
634 			       __func__);
635 		return;
636 	}
637 	memset(&cq, 0, sizeof(cq));
638 	cq.op = MISDN_CTRL_GETOP;
639 	if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq) < 0) {
640 		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
641 		       __func__);
642 		return;
643 	}
644 	if (cq.op & MISDN_CTRL_RX_OFF)
645 		dsp->features_rx_off = 1;
646 	if (cq.op & MISDN_CTRL_FILL_EMPTY)
647 		dsp->features_fill_empty = 1;
648 	if (dsp_options & DSP_OPT_NOHARDWARE)
649 		return;
650 	if ((cq.op & MISDN_CTRL_HW_FEATURES_OP)) {
651 		cq.op = MISDN_CTRL_HW_FEATURES;
652 		*((u_long *)&cq.p1) = (u_long)&dsp->features;
653 		if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq)) {
654 			printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
655 			       __func__);
656 		}
657 	} else
658 		if (dsp_debug & DEBUG_DSP_CORE)
659 			printk(KERN_DEBUG "%s: features not supported for %s\n",
660 			       __func__, dsp->name);
661 }
662 
663 static int
664 dsp_function(struct mISDNchannel *ch,  struct sk_buff *skb)
665 {
666 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
667 	struct mISDNhead	*hh;
668 	int			ret = 0;
669 	u8			*digits = NULL;
670 	u_long			flags;
671 
672 	hh = mISDN_HEAD_P(skb);
673 	switch (hh->prim) {
674 		/* FROM DOWN */
675 	case (PH_DATA_CNF):
676 		dsp->data_pending = 0;
677 		/* trigger next hdlc frame, if any */
678 		if (dsp->hdlc) {
679 			spin_lock_irqsave(&dsp_lock, flags);
680 			if (dsp->b_active)
681 				schedule_work(&dsp->workq);
682 			spin_unlock_irqrestore(&dsp_lock, flags);
683 		}
684 		break;
685 	case (PH_DATA_IND):
686 	case (DL_DATA_IND):
687 		if (skb->len < 1) {
688 			ret = -EINVAL;
689 			break;
690 		}
691 		if (dsp->rx_is_off) {
692 			if (dsp_debug & DEBUG_DSP_CORE)
693 				printk(KERN_DEBUG "%s: rx-data during rx_off"
694 				       " for %s\n",
695 				       __func__, dsp->name);
696 		}
697 		if (dsp->hdlc) {
698 			/* hdlc */
699 			spin_lock_irqsave(&dsp_lock, flags);
700 			dsp_cmx_hdlc(dsp, skb);
701 			spin_unlock_irqrestore(&dsp_lock, flags);
702 			if (dsp->rx_disabled) {
703 				/* if receive is not allowed */
704 				break;
705 			}
706 			hh->prim = DL_DATA_IND;
707 			if (dsp->up)
708 				return dsp->up->send(dsp->up, skb);
709 			break;
710 		}
711 
712 		spin_lock_irqsave(&dsp_lock, flags);
713 
714 		/* decrypt if enabled */
715 		if (dsp->bf_enable)
716 			dsp_bf_decrypt(dsp, skb->data, skb->len);
717 		/* pipeline */
718 		if (dsp->pipeline.inuse)
719 			dsp_pipeline_process_rx(&dsp->pipeline, skb->data,
720 						skb->len, hh->id);
721 		/* change volume if requested */
722 		if (dsp->rx_volume)
723 			dsp_change_volume(skb, dsp->rx_volume);
724 		/* check if dtmf soft decoding is turned on */
725 		if (dsp->dtmf.software) {
726 			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
727 							  skb->len, (dsp_options & DSP_OPT_ULAW) ? 1 : 0);
728 		}
729 		/* we need to process receive data if software */
730 		if (dsp->conf && dsp->conf->software) {
731 			/* process data from card at cmx */
732 			dsp_cmx_receive(dsp, skb);
733 		}
734 
735 		spin_unlock_irqrestore(&dsp_lock, flags);
736 
737 		/* send dtmf result, if any */
738 		if (digits) {
739 			while (*digits) {
740 				int k;
741 				struct sk_buff *nskb;
742 				if (dsp_debug & DEBUG_DSP_DTMF)
743 					printk(KERN_DEBUG "%s: digit"
744 					       "(%c) to layer %s\n",
745 					       __func__, *digits, dsp->name);
746 				k = *digits | DTMF_TONE_VAL;
747 				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
748 							MISDN_ID_ANY, sizeof(int), &k,
749 							GFP_ATOMIC);
750 				if (nskb) {
751 					if (dsp->up) {
752 						if (dsp->up->send(
753 							    dsp->up, nskb))
754 							dev_kfree_skb(nskb);
755 					} else
756 						dev_kfree_skb(nskb);
757 				}
758 				digits++;
759 			}
760 		}
761 		if (dsp->rx_disabled) {
762 			/* if receive is not allowed */
763 			break;
764 		}
765 		hh->prim = DL_DATA_IND;
766 		if (dsp->up)
767 			return dsp->up->send(dsp->up, skb);
768 		break;
769 	case (PH_CONTROL_IND):
770 		if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
771 			printk(KERN_DEBUG "%s: PH_CONTROL INDICATION "
772 			       "received: %x (len %d) %s\n", __func__,
773 			       hh->id, skb->len, dsp->name);
774 		switch (hh->id) {
775 		case (DTMF_HFC_COEF): /* getting coefficients */
776 			if (!dsp->dtmf.hardware) {
777 				if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
778 					printk(KERN_DEBUG "%s: ignoring DTMF "
779 					       "coefficients from HFC\n",
780 					       __func__);
781 				break;
782 			}
783 			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
784 							  skb->len, 2);
785 			while (*digits) {
786 				int k;
787 				struct sk_buff *nskb;
788 				if (dsp_debug & DEBUG_DSP_DTMF)
789 					printk(KERN_DEBUG "%s: digit"
790 					       "(%c) to layer %s\n",
791 					       __func__, *digits, dsp->name);
792 				k = *digits | DTMF_TONE_VAL;
793 				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
794 							MISDN_ID_ANY, sizeof(int), &k,
795 							GFP_ATOMIC);
796 				if (nskb) {
797 					if (dsp->up) {
798 						if (dsp->up->send(
799 							    dsp->up, nskb))
800 							dev_kfree_skb(nskb);
801 					} else
802 						dev_kfree_skb(nskb);
803 				}
804 				digits++;
805 			}
806 			break;
807 		case (HFC_VOL_CHANGE_TX): /* change volume */
808 			if (skb->len != sizeof(int)) {
809 				ret = -EINVAL;
810 				break;
811 			}
812 			spin_lock_irqsave(&dsp_lock, flags);
813 			dsp->tx_volume = *((int *)skb->data);
814 			if (dsp_debug & DEBUG_DSP_CORE)
815 				printk(KERN_DEBUG "%s: change tx volume to "
816 				       "%d\n", __func__, dsp->tx_volume);
817 			dsp_cmx_hardware(dsp->conf, dsp);
818 			dsp_dtmf_hardware(dsp);
819 			dsp_rx_off(dsp);
820 			spin_unlock_irqrestore(&dsp_lock, flags);
821 			break;
822 		default:
823 			if (dsp_debug & DEBUG_DSP_CORE)
824 				printk(KERN_DEBUG "%s: ctrl ind %x unhandled "
825 				       "%s\n", __func__, hh->id, dsp->name);
826 			ret = -EINVAL;
827 		}
828 		break;
829 	case (PH_ACTIVATE_IND):
830 	case (PH_ACTIVATE_CNF):
831 		if (dsp_debug & DEBUG_DSP_CORE)
832 			printk(KERN_DEBUG "%s: b_channel is now active %s\n",
833 			       __func__, dsp->name);
834 		/* bchannel now active */
835 		spin_lock_irqsave(&dsp_lock, flags);
836 		dsp->b_active = 1;
837 		dsp->data_pending = 0;
838 		dsp->rx_init = 1;
839 		/* rx_W and rx_R will be adjusted on first frame */
840 		dsp->rx_W = 0;
841 		dsp->rx_R = 0;
842 		memset(dsp->rx_buff, 0, sizeof(dsp->rx_buff));
843 		dsp_cmx_hardware(dsp->conf, dsp);
844 		dsp_dtmf_hardware(dsp);
845 		dsp_rx_off(dsp);
846 		spin_unlock_irqrestore(&dsp_lock, flags);
847 		if (dsp_debug & DEBUG_DSP_CORE)
848 			printk(KERN_DEBUG "%s: done with activation, sending "
849 			       "confirm to user space. %s\n", __func__,
850 			       dsp->name);
851 		/* send activation to upper layer */
852 		hh->prim = DL_ESTABLISH_CNF;
853 		if (dsp->up)
854 			return dsp->up->send(dsp->up, skb);
855 		break;
856 	case (PH_DEACTIVATE_IND):
857 	case (PH_DEACTIVATE_CNF):
858 		if (dsp_debug & DEBUG_DSP_CORE)
859 			printk(KERN_DEBUG "%s: b_channel is now inactive %s\n",
860 			       __func__, dsp->name);
861 		/* bchannel now inactive */
862 		spin_lock_irqsave(&dsp_lock, flags);
863 		dsp->b_active = 0;
864 		dsp->data_pending = 0;
865 		dsp_cmx_hardware(dsp->conf, dsp);
866 		dsp_rx_off(dsp);
867 		spin_unlock_irqrestore(&dsp_lock, flags);
868 		hh->prim = DL_RELEASE_CNF;
869 		if (dsp->up)
870 			return dsp->up->send(dsp->up, skb);
871 		break;
872 		/* FROM UP */
873 	case (DL_DATA_REQ):
874 	case (PH_DATA_REQ):
875 		if (skb->len < 1) {
876 			ret = -EINVAL;
877 			break;
878 		}
879 		if (dsp->hdlc) {
880 			/* hdlc */
881 			if (!dsp->b_active) {
882 				ret = -EIO;
883 				break;
884 			}
885 			hh->prim = PH_DATA_REQ;
886 			spin_lock_irqsave(&dsp_lock, flags);
887 			skb_queue_tail(&dsp->sendq, skb);
888 			schedule_work(&dsp->workq);
889 			spin_unlock_irqrestore(&dsp_lock, flags);
890 			return 0;
891 		}
892 		/* send data to tx-buffer (if no tone is played) */
893 		if (!dsp->tone.tone) {
894 			spin_lock_irqsave(&dsp_lock, flags);
895 			dsp_cmx_transmit(dsp, skb);
896 			spin_unlock_irqrestore(&dsp_lock, flags);
897 		}
898 		break;
899 	case (PH_CONTROL_REQ):
900 		spin_lock_irqsave(&dsp_lock, flags);
901 		ret = dsp_control_req(dsp, hh, skb);
902 		spin_unlock_irqrestore(&dsp_lock, flags);
903 		break;
904 	case (DL_ESTABLISH_REQ):
905 	case (PH_ACTIVATE_REQ):
906 		if (dsp_debug & DEBUG_DSP_CORE)
907 			printk(KERN_DEBUG "%s: activating b_channel %s\n",
908 			       __func__, dsp->name);
909 		if (dsp->dtmf.hardware || dsp->dtmf.software)
910 			dsp_dtmf_goertzel_init(dsp);
911 		get_features(ch);
912 		/* enable fill_empty feature */
913 		if (dsp->features_fill_empty)
914 			dsp_fill_empty(dsp);
915 		/* send ph_activate */
916 		hh->prim = PH_ACTIVATE_REQ;
917 		if (ch->peer)
918 			return ch->recv(ch->peer, skb);
919 		break;
920 	case (DL_RELEASE_REQ):
921 	case (PH_DEACTIVATE_REQ):
922 		if (dsp_debug & DEBUG_DSP_CORE)
923 			printk(KERN_DEBUG "%s: releasing b_channel %s\n",
924 			       __func__, dsp->name);
925 		spin_lock_irqsave(&dsp_lock, flags);
926 		dsp->tone.tone = 0;
927 		dsp->tone.hardware = 0;
928 		dsp->tone.software = 0;
929 		if (timer_pending(&dsp->tone.tl))
930 			del_timer(&dsp->tone.tl);
931 		if (dsp->conf)
932 			dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be
933 						 called here */
934 		skb_queue_purge(&dsp->sendq);
935 		spin_unlock_irqrestore(&dsp_lock, flags);
936 		hh->prim = PH_DEACTIVATE_REQ;
937 		if (ch->peer)
938 			return ch->recv(ch->peer, skb);
939 		break;
940 	default:
941 		if (dsp_debug & DEBUG_DSP_CORE)
942 			printk(KERN_DEBUG "%s: msg %x unhandled %s\n",
943 			       __func__, hh->prim, dsp->name);
944 		ret = -EINVAL;
945 	}
946 	if (!ret)
947 		dev_kfree_skb(skb);
948 	return ret;
949 }
950 
951 static int
952 dsp_ctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
953 {
954 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
955 	u_long		flags;
956 
957 	if (debug & DEBUG_DSP_CTRL)
958 		printk(KERN_DEBUG "%s:(%x)\n", __func__, cmd);
959 
960 	switch (cmd) {
961 	case OPEN_CHANNEL:
962 		break;
963 	case CLOSE_CHANNEL:
964 		if (dsp->ch.peer)
965 			dsp->ch.peer->ctrl(dsp->ch.peer, CLOSE_CHANNEL, NULL);
966 
967 		/* wait until workqueue has finished,
968 		 * must lock here, or we may hit send-process currently
969 		 * queueing. */
970 		spin_lock_irqsave(&dsp_lock, flags);
971 		dsp->b_active = 0;
972 		spin_unlock_irqrestore(&dsp_lock, flags);
973 		/* MUST not be locked, because it waits until queue is done. */
974 		cancel_work_sync(&dsp->workq);
975 		spin_lock_irqsave(&dsp_lock, flags);
976 		if (timer_pending(&dsp->tone.tl))
977 			del_timer(&dsp->tone.tl);
978 		skb_queue_purge(&dsp->sendq);
979 		if (dsp_debug & DEBUG_DSP_CTRL)
980 			printk(KERN_DEBUG "%s: releasing member %s\n",
981 			       __func__, dsp->name);
982 		dsp->b_active = 0;
983 		dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be called
984 					 here */
985 		dsp_pipeline_destroy(&dsp->pipeline);
986 
987 		if (dsp_debug & DEBUG_DSP_CTRL)
988 			printk(KERN_DEBUG "%s: remove & destroy object %s\n",
989 			       __func__, dsp->name);
990 		list_del(&dsp->list);
991 		spin_unlock_irqrestore(&dsp_lock, flags);
992 
993 		if (dsp_debug & DEBUG_DSP_CTRL)
994 			printk(KERN_DEBUG "%s: dsp instance released\n",
995 			       __func__);
996 		vfree(dsp);
997 		module_put(THIS_MODULE);
998 		break;
999 	}
1000 	return 0;
1001 }
1002 
1003 static void
1004 dsp_send_bh(struct work_struct *work)
1005 {
1006 	struct dsp *dsp = container_of(work, struct dsp, workq);
1007 	struct sk_buff *skb;
1008 	struct mISDNhead	*hh;
1009 
1010 	if (dsp->hdlc && dsp->data_pending)
1011 		return; /* wait until data has been acknowledged */
1012 
1013 	/* send queued data */
1014 	while ((skb = skb_dequeue(&dsp->sendq))) {
1015 		/* in locked date, we must have still data in queue */
1016 		if (dsp->data_pending) {
1017 			if (dsp_debug & DEBUG_DSP_CORE)
1018 				printk(KERN_DEBUG "%s: fifo full %s, this is "
1019 				       "no bug!\n", __func__, dsp->name);
1020 			/* flush transparent data, if not acked */
1021 			dev_kfree_skb(skb);
1022 			continue;
1023 		}
1024 		hh = mISDN_HEAD_P(skb);
1025 		if (hh->prim == DL_DATA_REQ) {
1026 			/* send packet up */
1027 			if (dsp->up) {
1028 				if (dsp->up->send(dsp->up, skb))
1029 					dev_kfree_skb(skb);
1030 			} else
1031 				dev_kfree_skb(skb);
1032 		} else {
1033 			/* send packet down */
1034 			if (dsp->ch.peer) {
1035 				dsp->data_pending = 1;
1036 				if (dsp->ch.recv(dsp->ch.peer, skb)) {
1037 					dev_kfree_skb(skb);
1038 					dsp->data_pending = 0;
1039 				}
1040 			} else
1041 				dev_kfree_skb(skb);
1042 		}
1043 	}
1044 }
1045 
1046 static int
1047 dspcreate(struct channel_req *crq)
1048 {
1049 	struct dsp		*ndsp;
1050 	u_long		flags;
1051 
1052 	if (crq->protocol != ISDN_P_B_L2DSP
1053 	    && crq->protocol != ISDN_P_B_L2DSPHDLC)
1054 		return -EPROTONOSUPPORT;
1055 	ndsp = vzalloc(sizeof(struct dsp));
1056 	if (!ndsp) {
1057 		printk(KERN_ERR "%s: vmalloc struct dsp failed\n", __func__);
1058 		return -ENOMEM;
1059 	}
1060 	if (dsp_debug & DEBUG_DSP_CTRL)
1061 		printk(KERN_DEBUG "%s: creating new dsp instance\n", __func__);
1062 
1063 	/* default enabled */
1064 	INIT_WORK(&ndsp->workq, (void *)dsp_send_bh);
1065 	skb_queue_head_init(&ndsp->sendq);
1066 	ndsp->ch.send = dsp_function;
1067 	ndsp->ch.ctrl = dsp_ctrl;
1068 	ndsp->up = crq->ch;
1069 	crq->ch = &ndsp->ch;
1070 	if (crq->protocol == ISDN_P_B_L2DSP) {
1071 		crq->protocol = ISDN_P_B_RAW;
1072 		ndsp->hdlc = 0;
1073 	} else {
1074 		crq->protocol = ISDN_P_B_HDLC;
1075 		ndsp->hdlc = 1;
1076 	}
1077 	if (!try_module_get(THIS_MODULE))
1078 		printk(KERN_WARNING "%s:cannot get module\n",
1079 		       __func__);
1080 
1081 	sprintf(ndsp->name, "DSP_C%x(0x%p)",
1082 		ndsp->up->st->dev->id + 1, ndsp);
1083 	/* set frame size to start */
1084 	ndsp->features.hfc_id = -1; /* current PCM id */
1085 	ndsp->features.pcm_id = -1; /* current PCM id */
1086 	ndsp->pcm_slot_rx = -1; /* current CPM slot */
1087 	ndsp->pcm_slot_tx = -1;
1088 	ndsp->pcm_bank_rx = -1;
1089 	ndsp->pcm_bank_tx = -1;
1090 	ndsp->hfc_conf = -1; /* current conference number */
1091 	/* set tone timer */
1092 	timer_setup(&ndsp->tone.tl, dsp_tone_timeout, 0);
1093 
1094 	if (dtmfthreshold < 20 || dtmfthreshold > 500)
1095 		dtmfthreshold = 200;
1096 	ndsp->dtmf.treshold = dtmfthreshold * 10000;
1097 
1098 	/* init pipeline append to list */
1099 	spin_lock_irqsave(&dsp_lock, flags);
1100 	dsp_pipeline_init(&ndsp->pipeline);
1101 	list_add_tail(&ndsp->list, &dsp_ilist);
1102 	spin_unlock_irqrestore(&dsp_lock, flags);
1103 
1104 	return 0;
1105 }
1106 
1107 
1108 static struct Bprotocol DSP = {
1109 	.Bprotocols = (1 << (ISDN_P_B_L2DSP & ISDN_P_B_MASK))
1110 	| (1 << (ISDN_P_B_L2DSPHDLC & ISDN_P_B_MASK)),
1111 	.name = "dsp",
1112 	.create = dspcreate
1113 };
1114 
1115 static int __init dsp_init(void)
1116 {
1117 	int err;
1118 	int tics;
1119 
1120 	printk(KERN_INFO "DSP module %s\n", mISDN_dsp_revision);
1121 
1122 	dsp_options = options;
1123 	dsp_debug = debug;
1124 
1125 	/* set packet size */
1126 	dsp_poll = poll;
1127 	if (dsp_poll) {
1128 		if (dsp_poll > MAX_POLL) {
1129 			printk(KERN_ERR "%s: Wrong poll value (%d), use %d "
1130 			       "maximum.\n", __func__, poll, MAX_POLL);
1131 			err = -EINVAL;
1132 			return err;
1133 		}
1134 		if (dsp_poll < 8) {
1135 			printk(KERN_ERR "%s: Wrong poll value (%d), use 8 "
1136 			       "minimum.\n", __func__, dsp_poll);
1137 			err = -EINVAL;
1138 			return err;
1139 		}
1140 		dsp_tics = poll * HZ / 8000;
1141 		if (dsp_tics * 8000 != poll * HZ) {
1142 			printk(KERN_INFO "mISDN_dsp: Cannot clock every %d "
1143 			       "samples (0,125 ms). It is not a multiple of "
1144 			       "%d HZ.\n", poll, HZ);
1145 			err = -EINVAL;
1146 			return err;
1147 		}
1148 	} else {
1149 		poll = 8;
1150 		while (poll <= MAX_POLL) {
1151 			tics = (poll * HZ) / 8000;
1152 			if (tics * 8000 == poll * HZ) {
1153 				dsp_tics = tics;
1154 				dsp_poll = poll;
1155 				if (poll >= 64)
1156 					break;
1157 			}
1158 			poll++;
1159 		}
1160 	}
1161 	if (dsp_poll == 0) {
1162 		printk(KERN_INFO "mISDN_dsp: There is no multiple of kernel "
1163 		       "clock that equals exactly the duration of 8-256 "
1164 		       "samples. (Choose kernel clock speed like 100, 250, "
1165 		       "300, 1000)\n");
1166 		err = -EINVAL;
1167 		return err;
1168 	}
1169 	printk(KERN_INFO "mISDN_dsp: DSP clocks every %d samples. This equals "
1170 	       "%d jiffies.\n", dsp_poll, dsp_tics);
1171 
1172 	/* init conversion tables */
1173 	dsp_audio_generate_law_tables();
1174 	dsp_silence = (dsp_options & DSP_OPT_ULAW) ? 0xff : 0x2a;
1175 	dsp_audio_law_to_s32 = (dsp_options & DSP_OPT_ULAW) ?
1176 		dsp_audio_ulaw_to_s32 : dsp_audio_alaw_to_s32;
1177 	dsp_audio_generate_s2law_table();
1178 	dsp_audio_generate_seven();
1179 	dsp_audio_generate_mix_table();
1180 	if (dsp_options & DSP_OPT_ULAW)
1181 		dsp_audio_generate_ulaw_samples();
1182 	dsp_audio_generate_volume_changes();
1183 
1184 	err = dsp_pipeline_module_init();
1185 	if (err) {
1186 		printk(KERN_ERR "mISDN_dsp: Can't initialize pipeline, "
1187 		       "error(%d)\n", err);
1188 		return err;
1189 	}
1190 
1191 	err = mISDN_register_Bprotocol(&DSP);
1192 	if (err) {
1193 		printk(KERN_ERR "Can't register %s error(%d)\n", DSP.name, err);
1194 		return err;
1195 	}
1196 
1197 	/* set sample timer */
1198 	timer_setup(&dsp_spl_tl, dsp_cmx_send, 0);
1199 	dsp_spl_tl.expires = jiffies + dsp_tics;
1200 	dsp_spl_jiffies = dsp_spl_tl.expires;
1201 	add_timer(&dsp_spl_tl);
1202 
1203 	return 0;
1204 }
1205 
1206 
1207 static void __exit dsp_cleanup(void)
1208 {
1209 	mISDN_unregister_Bprotocol(&DSP);
1210 
1211 	del_timer_sync(&dsp_spl_tl);
1212 
1213 	if (!list_empty(&dsp_ilist)) {
1214 		printk(KERN_ERR "mISDN_dsp: Audio DSP object inst list not "
1215 		       "empty.\n");
1216 	}
1217 	if (!list_empty(&conf_ilist)) {
1218 		printk(KERN_ERR "mISDN_dsp: Conference list not empty. Not "
1219 		       "all memory freed.\n");
1220 	}
1221 
1222 	dsp_pipeline_module_exit();
1223 }
1224 
1225 module_init(dsp_init);
1226 module_exit(dsp_cleanup);
1227