xref: /openbmc/linux/drivers/isdn/mISDN/dsp_core.c (revision e8e0929d)
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 performane 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 loosing
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 usefull if only announcements are played. Not sending is
131  * usefull if an answering machine records audio. Not sending and receiving is
132  * usefull 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/mISDNif.h>
158 #include <linux/mISDNdsp.h>
159 #include <linux/module.h>
160 #include <linux/vmalloc.h>
161 #include "core.h"
162 #include "dsp.h"
163 
164 static const char *mISDN_dsp_revision = "2.0";
165 
166 static int debug;
167 static int options;
168 static int poll;
169 static int dtmfthreshold = 100;
170 
171 MODULE_AUTHOR("Andreas Eversberg");
172 module_param(debug, uint, S_IRUGO | S_IWUSR);
173 module_param(options, uint, S_IRUGO | S_IWUSR);
174 module_param(poll, uint, S_IRUGO | S_IWUSR);
175 module_param(dtmfthreshold, uint, S_IRUGO | S_IWUSR);
176 MODULE_LICENSE("GPL");
177 
178 /*int spinnest = 0;*/
179 
180 spinlock_t dsp_lock; /* global dsp lock */
181 struct list_head dsp_ilist;
182 struct 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 	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 	cont = *((int *)skb->data);
292 	len = skb->len - sizeof(int);
293 	data = skb->data + sizeof(int);
294 
295 	switch (cont) {
296 	case DTMF_TONE_START: /* turn on DTMF */
297 		if (dsp->hdlc) {
298 			ret = -EINVAL;
299 			break;
300 		}
301 		if (dsp_debug & DEBUG_DSP_CORE)
302 			printk(KERN_DEBUG "%s: start dtmf\n", __func__);
303 		if (len == sizeof(int)) {
304 			if (dsp_debug & DEBUG_DSP_CORE)
305 				printk(KERN_NOTICE "changing DTMF Threshold "
306 					"to %d\n", *((int *)data));
307 			dsp->dtmf.treshold = (*(int *)data) * 10000;
308 		}
309 		dsp->dtmf.enable = 1;
310 		/* init goertzel */
311 		dsp_dtmf_goertzel_init(dsp);
312 
313 		/* check dtmf hardware */
314 		dsp_dtmf_hardware(dsp);
315 		dsp_rx_off(dsp);
316 		break;
317 	case DTMF_TONE_STOP: /* turn off DTMF */
318 		if (dsp_debug & DEBUG_DSP_CORE)
319 			printk(KERN_DEBUG "%s: stop dtmf\n", __func__);
320 		dsp->dtmf.enable = 0;
321 		dsp->dtmf.hardware = 0;
322 		dsp->dtmf.software = 0;
323 		break;
324 	case DSP_CONF_JOIN: /* join / update conference */
325 		if (len < sizeof(int)) {
326 			ret = -EINVAL;
327 			break;
328 		}
329 		if (*((u32 *)data) == 0)
330 			goto conf_split;
331 		if (dsp_debug & DEBUG_DSP_CORE)
332 			printk(KERN_DEBUG "%s: join conference %d\n",
333 				__func__, *((u32 *)data));
334 		ret = dsp_cmx_conf(dsp, *((u32 *)data));
335 			/* dsp_cmx_hardware will also be called here */
336 		dsp_rx_off(dsp);
337 		if (dsp_debug & DEBUG_DSP_CMX)
338 			dsp_cmx_debug(dsp);
339 		break;
340 	case DSP_CONF_SPLIT: /* remove from conference */
341 conf_split:
342 		if (dsp_debug & DEBUG_DSP_CORE)
343 			printk(KERN_DEBUG "%s: release conference\n", __func__);
344 		ret = dsp_cmx_conf(dsp, 0);
345 			/* dsp_cmx_hardware will also be called here */
346 		if (dsp_debug & DEBUG_DSP_CMX)
347 			dsp_cmx_debug(dsp);
348 		dsp_rx_off(dsp);
349 		break;
350 	case DSP_TONE_PATT_ON: /* play tone */
351 		if (dsp->hdlc) {
352 			ret = -EINVAL;
353 			break;
354 		}
355 		if (len < sizeof(int)) {
356 			ret = -EINVAL;
357 			break;
358 		}
359 		if (dsp_debug & DEBUG_DSP_CORE)
360 			printk(KERN_DEBUG "%s: turn tone 0x%x on\n",
361 				__func__, *((int *)skb->data));
362 		ret = dsp_tone(dsp, *((int *)data));
363 		if (!ret) {
364 			dsp_cmx_hardware(dsp->conf, dsp);
365 			dsp_rx_off(dsp);
366 		}
367 		if (!dsp->tone.tone)
368 			goto tone_off;
369 		break;
370 	case DSP_TONE_PATT_OFF: /* stop tone */
371 		if (dsp->hdlc) {
372 			ret = -EINVAL;
373 			break;
374 		}
375 		if (dsp_debug & DEBUG_DSP_CORE)
376 			printk(KERN_DEBUG "%s: turn tone off\n", __func__);
377 		dsp_tone(dsp, 0);
378 		dsp_cmx_hardware(dsp->conf, dsp);
379 		dsp_rx_off(dsp);
380 		/* reset tx buffers (user space data) */
381 tone_off:
382 		dsp->rx_W = 0;
383 		dsp->rx_R = 0;
384 		break;
385 	case DSP_VOL_CHANGE_TX: /* change volume */
386 		if (dsp->hdlc) {
387 			ret = -EINVAL;
388 			break;
389 		}
390 		if (len < sizeof(int)) {
391 			ret = -EINVAL;
392 			break;
393 		}
394 		dsp->tx_volume = *((int *)data);
395 		if (dsp_debug & DEBUG_DSP_CORE)
396 			printk(KERN_DEBUG "%s: change tx vol to %d\n",
397 				__func__, dsp->tx_volume);
398 		dsp_cmx_hardware(dsp->conf, dsp);
399 		dsp_dtmf_hardware(dsp);
400 		dsp_rx_off(dsp);
401 		break;
402 	case DSP_VOL_CHANGE_RX: /* change volume */
403 		if (dsp->hdlc) {
404 			ret = -EINVAL;
405 			break;
406 		}
407 		if (len < sizeof(int)) {
408 			ret = -EINVAL;
409 			break;
410 		}
411 		dsp->rx_volume = *((int *)data);
412 		if (dsp_debug & DEBUG_DSP_CORE)
413 			printk(KERN_DEBUG "%s: change rx vol to %d\n",
414 				__func__, dsp->tx_volume);
415 		dsp_cmx_hardware(dsp->conf, dsp);
416 		dsp_dtmf_hardware(dsp);
417 		dsp_rx_off(dsp);
418 		break;
419 	case DSP_ECHO_ON: /* enable echo */
420 		dsp->echo.software = 1; /* soft echo */
421 		if (dsp_debug & DEBUG_DSP_CORE)
422 			printk(KERN_DEBUG "%s: enable cmx-echo\n", __func__);
423 		dsp_cmx_hardware(dsp->conf, dsp);
424 		dsp_rx_off(dsp);
425 		if (dsp_debug & DEBUG_DSP_CMX)
426 			dsp_cmx_debug(dsp);
427 		break;
428 	case DSP_ECHO_OFF: /* disable echo */
429 		dsp->echo.software = 0;
430 		dsp->echo.hardware = 0;
431 		if (dsp_debug & DEBUG_DSP_CORE)
432 			printk(KERN_DEBUG "%s: disable cmx-echo\n", __func__);
433 		dsp_cmx_hardware(dsp->conf, dsp);
434 		dsp_rx_off(dsp);
435 		if (dsp_debug & DEBUG_DSP_CMX)
436 			dsp_cmx_debug(dsp);
437 		break;
438 	case DSP_RECEIVE_ON: /* enable receive to user space */
439 		if (dsp_debug & DEBUG_DSP_CORE)
440 			printk(KERN_DEBUG "%s: enable receive to user "
441 				"space\n", __func__);
442 		dsp->rx_disabled = 0;
443 		dsp_rx_off(dsp);
444 		break;
445 	case DSP_RECEIVE_OFF: /* disable receive to user space */
446 		if (dsp_debug & DEBUG_DSP_CORE)
447 			printk(KERN_DEBUG "%s: disable receive to "
448 				"user space\n", __func__);
449 		dsp->rx_disabled = 1;
450 		dsp_rx_off(dsp);
451 		break;
452 	case DSP_MIX_ON: /* enable mixing of tx data */
453 		if (dsp->hdlc) {
454 			ret = -EINVAL;
455 			break;
456 		}
457 		if (dsp_debug & DEBUG_DSP_CORE)
458 			printk(KERN_DEBUG "%s: enable mixing of "
459 				"tx-data with conf mebers\n", __func__);
460 		dsp->tx_mix = 1;
461 		dsp_cmx_hardware(dsp->conf, dsp);
462 		dsp_rx_off(dsp);
463 		if (dsp_debug & DEBUG_DSP_CMX)
464 			dsp_cmx_debug(dsp);
465 		break;
466 	case DSP_MIX_OFF: /* disable mixing of tx data */
467 		if (dsp->hdlc) {
468 			ret = -EINVAL;
469 			break;
470 		}
471 		if (dsp_debug & DEBUG_DSP_CORE)
472 			printk(KERN_DEBUG "%s: disable mixing of "
473 				"tx-data with conf mebers\n", __func__);
474 		dsp->tx_mix = 0;
475 		dsp_cmx_hardware(dsp->conf, dsp);
476 		dsp_rx_off(dsp);
477 		if (dsp_debug & DEBUG_DSP_CMX)
478 			dsp_cmx_debug(dsp);
479 		break;
480 	case DSP_TXDATA_ON: /* enable txdata */
481 		dsp->tx_data = 1;
482 		if (dsp_debug & DEBUG_DSP_CORE)
483 			printk(KERN_DEBUG "%s: enable tx-data\n", __func__);
484 		dsp_cmx_hardware(dsp->conf, dsp);
485 		dsp_rx_off(dsp);
486 		if (dsp_debug & DEBUG_DSP_CMX)
487 			dsp_cmx_debug(dsp);
488 		break;
489 	case DSP_TXDATA_OFF: /* disable txdata */
490 		dsp->tx_data = 0;
491 		if (dsp_debug & DEBUG_DSP_CORE)
492 			printk(KERN_DEBUG "%s: disable tx-data\n", __func__);
493 		dsp_cmx_hardware(dsp->conf, dsp);
494 		dsp_rx_off(dsp);
495 		if (dsp_debug & DEBUG_DSP_CMX)
496 			dsp_cmx_debug(dsp);
497 		break;
498 	case DSP_DELAY: /* use delay algorithm instead of dynamic
499 			   jitter algorithm */
500 		if (dsp->hdlc) {
501 			ret = -EINVAL;
502 			break;
503 		}
504 		if (len < sizeof(int)) {
505 			ret = -EINVAL;
506 			break;
507 		}
508 		dsp->cmx_delay = (*((int *)data)) << 3;
509 			/* milliseconds to samples */
510 		if (dsp->cmx_delay >= (CMX_BUFF_HALF>>1))
511 			/* clip to half of maximum usable buffer
512 			(half of half buffer) */
513 			dsp->cmx_delay = (CMX_BUFF_HALF>>1) - 1;
514 		if (dsp_debug & DEBUG_DSP_CORE)
515 			printk(KERN_DEBUG "%s: use delay algorithm to "
516 				"compensate jitter (%d samples)\n",
517 				__func__, dsp->cmx_delay);
518 		break;
519 	case DSP_JITTER: /* use dynamic jitter algorithm instead of
520 		    delay algorithm */
521 		if (dsp->hdlc) {
522 			ret = -EINVAL;
523 			break;
524 		}
525 		dsp->cmx_delay = 0;
526 		if (dsp_debug & DEBUG_DSP_CORE)
527 			printk(KERN_DEBUG "%s: use jitter algorithm to "
528 				"compensate jitter\n", __func__);
529 		break;
530 	case DSP_TX_DEJITTER: /* use dynamic jitter algorithm for tx-buffer */
531 		if (dsp->hdlc) {
532 			ret = -EINVAL;
533 			break;
534 		}
535 		dsp->tx_dejitter = 1;
536 		if (dsp_debug & DEBUG_DSP_CORE)
537 			printk(KERN_DEBUG "%s: use dejitter on TX "
538 				"buffer\n", __func__);
539 		break;
540 	case DSP_TX_DEJ_OFF: /* use tx-buffer without dejittering*/
541 		if (dsp->hdlc) {
542 			ret = -EINVAL;
543 			break;
544 		}
545 		dsp->tx_dejitter = 0;
546 		if (dsp_debug & DEBUG_DSP_CORE)
547 			printk(KERN_DEBUG "%s: use TX buffer without "
548 				"dejittering\n", __func__);
549 		break;
550 	case DSP_PIPELINE_CFG:
551 		if (dsp->hdlc) {
552 			ret = -EINVAL;
553 			break;
554 		}
555 		if (len > 0 && ((char *)data)[len - 1]) {
556 			printk(KERN_DEBUG "%s: pipeline config string "
557 				"is not NULL terminated!\n", __func__);
558 			ret = -EINVAL;
559 		} else {
560 			dsp->pipeline.inuse = 1;
561 			dsp_cmx_hardware(dsp->conf, dsp);
562 			ret = dsp_pipeline_build(&dsp->pipeline,
563 				len > 0 ? data : NULL);
564 			dsp_cmx_hardware(dsp->conf, dsp);
565 			dsp_rx_off(dsp);
566 		}
567 		break;
568 	case DSP_BF_ENABLE_KEY: /* turn blowfish on */
569 		if (dsp->hdlc) {
570 			ret = -EINVAL;
571 			break;
572 		}
573 		if (len < 4 || len > 56) {
574 			ret = -EINVAL;
575 			break;
576 		}
577 		if (dsp_debug & DEBUG_DSP_CORE)
578 			printk(KERN_DEBUG "%s: turn blowfish on (key "
579 				"not shown)\n", __func__);
580 		ret = dsp_bf_init(dsp, (u8 *)data, len);
581 		/* set new cont */
582 		if (!ret)
583 			cont = DSP_BF_ACCEPT;
584 		else
585 			cont = DSP_BF_REJECT;
586 		/* send indication if it worked to set it */
587 		nskb = _alloc_mISDN_skb(PH_CONTROL_IND, MISDN_ID_ANY,
588 			sizeof(int), &cont, GFP_ATOMIC);
589 		if (nskb) {
590 			if (dsp->up) {
591 				if (dsp->up->send(dsp->up, nskb))
592 					dev_kfree_skb(nskb);
593 			} else
594 				dev_kfree_skb(nskb);
595 		}
596 		if (!ret) {
597 			dsp_cmx_hardware(dsp->conf, dsp);
598 			dsp_dtmf_hardware(dsp);
599 			dsp_rx_off(dsp);
600 		}
601 		break;
602 	case DSP_BF_DISABLE: /* turn blowfish off */
603 		if (dsp->hdlc) {
604 			ret = -EINVAL;
605 			break;
606 		}
607 		if (dsp_debug & DEBUG_DSP_CORE)
608 			printk(KERN_DEBUG "%s: turn blowfish off\n", __func__);
609 		dsp_bf_cleanup(dsp);
610 		dsp_cmx_hardware(dsp->conf, dsp);
611 		dsp_dtmf_hardware(dsp);
612 		dsp_rx_off(dsp);
613 		break;
614 	default:
615 		if (dsp_debug & DEBUG_DSP_CORE)
616 			printk(KERN_DEBUG "%s: ctrl req %x unhandled\n",
617 				__func__, cont);
618 		ret = -EINVAL;
619 	}
620 	return ret;
621 }
622 
623 static void
624 get_features(struct mISDNchannel *ch)
625 {
626 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
627 	struct mISDN_ctrl_req	cq;
628 
629 	if (!ch->peer) {
630 		if (dsp_debug & DEBUG_DSP_CORE)
631 			printk(KERN_DEBUG "%s: no peer, no features\n",
632 				__func__);
633 		return;
634 	}
635 	memset(&cq, 0, sizeof(cq));
636 	cq.op = MISDN_CTRL_GETOP;
637 	if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq) < 0) {
638 		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
639 			__func__);
640 		return;
641 	}
642 	if (cq.op & MISDN_CTRL_RX_OFF)
643 		dsp->features_rx_off = 1;
644 	if (cq.op & MISDN_CTRL_FILL_EMPTY)
645 		dsp->features_fill_empty = 1;
646 	if (dsp_options & DSP_OPT_NOHARDWARE)
647 		return;
648 	if ((cq.op & MISDN_CTRL_HW_FEATURES_OP)) {
649 		cq.op = MISDN_CTRL_HW_FEATURES;
650 		*((u_long *)&cq.p1) = (u_long)&dsp->features;
651 		if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq)) {
652 			printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
653 				__func__);
654 		}
655 	} else
656 		if (dsp_debug & DEBUG_DSP_CORE)
657 			printk(KERN_DEBUG "%s: features not supported for %s\n",
658 				__func__, dsp->name);
659 }
660 
661 static int
662 dsp_function(struct mISDNchannel *ch,  struct sk_buff *skb)
663 {
664 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
665 	struct mISDNhead	*hh;
666 	int			ret = 0;
667 	u8			*digits = NULL;
668 	u_long			flags;
669 
670 	hh = mISDN_HEAD_P(skb);
671 	switch (hh->prim) {
672 	/* FROM DOWN */
673 	case (PH_DATA_CNF):
674 		dsp->data_pending = 0;
675 		/* trigger next hdlc frame, if any */
676 		if (dsp->hdlc) {
677 			spin_lock_irqsave(&dsp_lock, flags);
678 			if (dsp->b_active)
679 				schedule_work(&dsp->workq);
680 			spin_unlock_irqrestore(&dsp_lock, flags);
681 		}
682 		break;
683 	case (PH_DATA_IND):
684 	case (DL_DATA_IND):
685 		if (skb->len < 1) {
686 			ret = -EINVAL;
687 			break;
688 		}
689 		if (dsp->rx_is_off) {
690 			if (dsp_debug & DEBUG_DSP_CORE)
691 				printk(KERN_DEBUG "%s: rx-data during rx_off"
692 					" for %s\n",
693 				__func__, dsp->name);
694 		}
695 		if (dsp->hdlc) {
696 			/* hdlc */
697 			spin_lock_irqsave(&dsp_lock, flags);
698 			dsp_cmx_hdlc(dsp, skb);
699 			spin_unlock_irqrestore(&dsp_lock, flags);
700 			if (dsp->rx_disabled) {
701 				/* if receive is not allowed */
702 				break;
703 			}
704 			hh->prim = DL_DATA_IND;
705 			if (dsp->up)
706 				return dsp->up->send(dsp->up, skb);
707 			break;
708 		}
709 
710 		spin_lock_irqsave(&dsp_lock, flags);
711 
712 		/* decrypt if enabled */
713 		if (dsp->bf_enable)
714 			dsp_bf_decrypt(dsp, skb->data, skb->len);
715 		/* pipeline */
716 		if (dsp->pipeline.inuse)
717 			dsp_pipeline_process_rx(&dsp->pipeline, skb->data,
718 				skb->len, hh->id);
719 		/* change volume if requested */
720 		if (dsp->rx_volume)
721 			dsp_change_volume(skb, dsp->rx_volume);
722 		/* check if dtmf soft decoding is turned on */
723 		if (dsp->dtmf.software) {
724 			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
725 				skb->len, (dsp_options&DSP_OPT_ULAW) ? 1 : 0);
726 		}
727 		/* we need to process receive data if software */
728 		if (dsp->conf && dsp->conf->software) {
729 			/* process data from card at cmx */
730 			dsp_cmx_receive(dsp, skb);
731 		}
732 
733 		spin_unlock_irqrestore(&dsp_lock, flags);
734 
735 		/* send dtmf result, if any */
736 		if (digits) {
737 			while (*digits) {
738 				int k;
739 				struct sk_buff *nskb;
740 				if (dsp_debug & DEBUG_DSP_DTMF)
741 					printk(KERN_DEBUG "%s: digit"
742 					    "(%c) to layer %s\n",
743 					    __func__, *digits, dsp->name);
744 				k = *digits | DTMF_TONE_VAL;
745 				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
746 					MISDN_ID_ANY, sizeof(int), &k,
747 					GFP_ATOMIC);
748 				if (nskb) {
749 					if (dsp->up) {
750 						if (dsp->up->send(
751 						    dsp->up, nskb))
752 							dev_kfree_skb(nskb);
753 					} else
754 						dev_kfree_skb(nskb);
755 				}
756 				digits++;
757 			}
758 		}
759 		if (dsp->rx_disabled) {
760 			/* if receive is not allowed */
761 			break;
762 		}
763 		hh->prim = DL_DATA_IND;
764 		if (dsp->up)
765 			return dsp->up->send(dsp->up, skb);
766 		break;
767 	case (PH_CONTROL_IND):
768 		if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
769 			printk(KERN_DEBUG "%s: PH_CONTROL INDICATION "
770 				"received: %x (len %d) %s\n", __func__,
771 				hh->id, skb->len, dsp->name);
772 		switch (hh->id) {
773 		case (DTMF_HFC_COEF): /* getting coefficients */
774 			if (!dsp->dtmf.hardware) {
775 				if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
776 					printk(KERN_DEBUG "%s: ignoring DTMF "
777 						"coefficients from HFC\n",
778 						__func__);
779 				break;
780 			}
781 			digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
782 				skb->len, 2);
783 			while (*digits) {
784 				int k;
785 				struct sk_buff *nskb;
786 				if (dsp_debug & DEBUG_DSP_DTMF)
787 					printk(KERN_DEBUG "%s: digit"
788 					    "(%c) to layer %s\n",
789 					    __func__, *digits, dsp->name);
790 				k = *digits | DTMF_TONE_VAL;
791 				nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
792 					MISDN_ID_ANY, sizeof(int), &k,
793 					GFP_ATOMIC);
794 				if (nskb) {
795 					if (dsp->up) {
796 						if (dsp->up->send(
797 						    dsp->up, nskb))
798 							dev_kfree_skb(nskb);
799 					} else
800 						dev_kfree_skb(nskb);
801 				}
802 				digits++;
803 			}
804 			break;
805 		case (HFC_VOL_CHANGE_TX): /* change volume */
806 			if (skb->len != sizeof(int)) {
807 				ret = -EINVAL;
808 				break;
809 			}
810 			spin_lock_irqsave(&dsp_lock, flags);
811 			dsp->tx_volume = *((int *)skb->data);
812 			if (dsp_debug & DEBUG_DSP_CORE)
813 				printk(KERN_DEBUG "%s: change tx volume to "
814 					"%d\n", __func__, dsp->tx_volume);
815 			dsp_cmx_hardware(dsp->conf, dsp);
816 			dsp_dtmf_hardware(dsp);
817 			dsp_rx_off(dsp);
818 			spin_unlock_irqrestore(&dsp_lock, flags);
819 			break;
820 		default:
821 			if (dsp_debug & DEBUG_DSP_CORE)
822 				printk(KERN_DEBUG "%s: ctrl ind %x unhandled "
823 					"%s\n", __func__, hh->id, dsp->name);
824 			ret = -EINVAL;
825 		}
826 		break;
827 	case (PH_ACTIVATE_IND):
828 	case (PH_ACTIVATE_CNF):
829 		if (dsp_debug & DEBUG_DSP_CORE)
830 			printk(KERN_DEBUG "%s: b_channel is now active %s\n",
831 				__func__, dsp->name);
832 		/* bchannel now active */
833 		spin_lock_irqsave(&dsp_lock, flags);
834 		dsp->b_active = 1;
835 		dsp->data_pending = 0;
836 		dsp->rx_init = 1;
837 			/* rx_W and rx_R will be adjusted on first frame */
838 		dsp->rx_W = 0;
839 		dsp->rx_R = 0;
840 		memset(dsp->rx_buff, 0, sizeof(dsp->rx_buff));
841 		dsp_cmx_hardware(dsp->conf, dsp);
842 		dsp_dtmf_hardware(dsp);
843 		dsp_rx_off(dsp);
844 		spin_unlock_irqrestore(&dsp_lock, flags);
845 		if (dsp_debug & DEBUG_DSP_CORE)
846 			printk(KERN_DEBUG "%s: done with activation, sending "
847 				"confirm to user space. %s\n", __func__,
848 				dsp->name);
849 		/* send activation to upper layer */
850 		hh->prim = DL_ESTABLISH_CNF;
851 		if (dsp->up)
852 			return dsp->up->send(dsp->up, skb);
853 		break;
854 	case (PH_DEACTIVATE_IND):
855 	case (PH_DEACTIVATE_CNF):
856 		if (dsp_debug & DEBUG_DSP_CORE)
857 			printk(KERN_DEBUG "%s: b_channel is now inactive %s\n",
858 				__func__, dsp->name);
859 		/* bchannel now inactive */
860 		spin_lock_irqsave(&dsp_lock, flags);
861 		dsp->b_active = 0;
862 		dsp->data_pending = 0;
863 		dsp_cmx_hardware(dsp->conf, dsp);
864 		dsp_rx_off(dsp);
865 		spin_unlock_irqrestore(&dsp_lock, flags);
866 		hh->prim = DL_RELEASE_CNF;
867 		if (dsp->up)
868 			return dsp->up->send(dsp->up, skb);
869 		break;
870 	/* FROM UP */
871 	case (DL_DATA_REQ):
872 	case (PH_DATA_REQ):
873 		if (skb->len < 1) {
874 			ret = -EINVAL;
875 			break;
876 		}
877 		if (dsp->hdlc) {
878 			/* hdlc */
879 			if (!dsp->b_active) {
880 				ret = -EIO;
881 				break;
882 			}
883 			hh->prim = PH_DATA_REQ;
884 			spin_lock_irqsave(&dsp_lock, flags);
885 			skb_queue_tail(&dsp->sendq, skb);
886 			schedule_work(&dsp->workq);
887 			spin_unlock_irqrestore(&dsp_lock, flags);
888 			return 0;
889 		}
890 		/* send data to tx-buffer (if no tone is played) */
891 		if (!dsp->tone.tone) {
892 			spin_lock_irqsave(&dsp_lock, flags);
893 			dsp_cmx_transmit(dsp, skb);
894 			spin_unlock_irqrestore(&dsp_lock, flags);
895 		}
896 		break;
897 	case (PH_CONTROL_REQ):
898 		spin_lock_irqsave(&dsp_lock, flags);
899 		ret = dsp_control_req(dsp, hh, skb);
900 		spin_unlock_irqrestore(&dsp_lock, flags);
901 		break;
902 	case (DL_ESTABLISH_REQ):
903 	case (PH_ACTIVATE_REQ):
904 		if (dsp_debug & DEBUG_DSP_CORE)
905 			printk(KERN_DEBUG "%s: activating b_channel %s\n",
906 				__func__, dsp->name);
907 		if (dsp->dtmf.hardware || dsp->dtmf.software)
908 			dsp_dtmf_goertzel_init(dsp);
909 		get_features(ch);
910 		/* enable fill_empty feature */
911 		if (dsp->features_fill_empty)
912 			dsp_fill_empty(dsp);
913 		/* send ph_activate */
914 		hh->prim = PH_ACTIVATE_REQ;
915 		if (ch->peer)
916 			return ch->recv(ch->peer, skb);
917 		break;
918 	case (DL_RELEASE_REQ):
919 	case (PH_DEACTIVATE_REQ):
920 		if (dsp_debug & DEBUG_DSP_CORE)
921 			printk(KERN_DEBUG "%s: releasing b_channel %s\n",
922 				__func__, dsp->name);
923 		spin_lock_irqsave(&dsp_lock, flags);
924 		dsp->tone.tone = 0;
925 		dsp->tone.hardware = 0;
926 		dsp->tone.software = 0;
927 		if (timer_pending(&dsp->tone.tl))
928 			del_timer(&dsp->tone.tl);
929 		if (dsp->conf)
930 			dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be
931 						 called here */
932 		skb_queue_purge(&dsp->sendq);
933 		spin_unlock_irqrestore(&dsp_lock, flags);
934 		hh->prim = PH_DEACTIVATE_REQ;
935 		if (ch->peer)
936 			return ch->recv(ch->peer, skb);
937 		break;
938 	default:
939 		if (dsp_debug & DEBUG_DSP_CORE)
940 			printk(KERN_DEBUG "%s: msg %x unhandled %s\n",
941 				__func__, hh->prim, dsp->name);
942 		ret = -EINVAL;
943 	}
944 	if (!ret)
945 		dev_kfree_skb(skb);
946 	return ret;
947 }
948 
949 static int
950 dsp_ctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
951 {
952 	struct dsp		*dsp = container_of(ch, struct dsp, ch);
953 	u_long		flags;
954 	int		err = 0;
955 
956 	if (debug & DEBUG_DSP_CTRL)
957 		printk(KERN_DEBUG "%s:(%x)\n", __func__, cmd);
958 
959 	switch (cmd) {
960 	case OPEN_CHANNEL:
961 		break;
962 	case CLOSE_CHANNEL:
963 		if (dsp->ch.peer)
964 			dsp->ch.peer->ctrl(dsp->ch.peer, CLOSE_CHANNEL, NULL);
965 
966 		/* wait until workqueue has finished,
967 		 * must lock here, or we may hit send-process currently
968 		 * queueing. */
969 		spin_lock_irqsave(&dsp_lock, flags);
970 		dsp->b_active = 0;
971 		spin_unlock_irqrestore(&dsp_lock, flags);
972 		/* MUST not be locked, because it waits until queue is done. */
973 		cancel_work_sync(&dsp->workq);
974 		spin_lock_irqsave(&dsp_lock, flags);
975 		if (timer_pending(&dsp->tone.tl))
976 			del_timer(&dsp->tone.tl);
977 		skb_queue_purge(&dsp->sendq);
978 		if (dsp_debug & DEBUG_DSP_CTRL)
979 			printk(KERN_DEBUG "%s: releasing member %s\n",
980 				__func__, dsp->name);
981 		dsp->b_active = 0;
982 		dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be called
983 					 here */
984 		dsp_pipeline_destroy(&dsp->pipeline);
985 
986 		if (dsp_debug & DEBUG_DSP_CTRL)
987 			printk(KERN_DEBUG "%s: remove & destroy object %s\n",
988 				__func__, dsp->name);
989 		list_del(&dsp->list);
990 		spin_unlock_irqrestore(&dsp_lock, flags);
991 
992 		if (dsp_debug & DEBUG_DSP_CTRL)
993 			printk(KERN_DEBUG "%s: dsp instance released\n",
994 				__func__);
995 		vfree(dsp);
996 		module_put(THIS_MODULE);
997 		break;
998 	}
999 	return err;
1000 }
1001 
1002 static void
1003 dsp_send_bh(struct work_struct *work)
1004 {
1005 	struct dsp *dsp = container_of(work, struct dsp, workq);
1006 	struct sk_buff *skb;
1007 	struct mISDNhead	*hh;
1008 
1009 	if (dsp->hdlc && dsp->data_pending)
1010 		return; /* wait until data has been acknowledged */
1011 
1012 	/* send queued data */
1013 	while ((skb = skb_dequeue(&dsp->sendq))) {
1014 		/* in locked date, we must have still data in queue */
1015 		if (dsp->data_pending) {
1016 			if (dsp_debug & DEBUG_DSP_CORE)
1017 				printk(KERN_DEBUG "%s: fifo full %s, this is "
1018 					"no bug!\n", __func__, dsp->name);
1019 			/* flush transparent data, if not acked */
1020 			dev_kfree_skb(skb);
1021 			continue;
1022 		}
1023 		hh = mISDN_HEAD_P(skb);
1024 		if (hh->prim == DL_DATA_REQ) {
1025 			/* send packet up */
1026 			if (dsp->up) {
1027 				if (dsp->up->send(dsp->up, skb))
1028 					dev_kfree_skb(skb);
1029 			} else
1030 				dev_kfree_skb(skb);
1031 		} else {
1032 			/* send packet down */
1033 			if (dsp->ch.peer) {
1034 				dsp->data_pending = 1;
1035 				if (dsp->ch.recv(dsp->ch.peer, skb)) {
1036 					dev_kfree_skb(skb);
1037 					dsp->data_pending = 0;
1038 				}
1039 			} else
1040 				dev_kfree_skb(skb);
1041 		}
1042 	}
1043 }
1044 
1045 static int
1046 dspcreate(struct channel_req *crq)
1047 {
1048 	struct dsp		*ndsp;
1049 	u_long		flags;
1050 
1051 	if (crq->protocol != ISDN_P_B_L2DSP
1052 	 && crq->protocol != ISDN_P_B_L2DSPHDLC)
1053 		return -EPROTONOSUPPORT;
1054 	ndsp = vmalloc(sizeof(struct dsp));
1055 	if (!ndsp) {
1056 		printk(KERN_ERR "%s: vmalloc struct dsp failed\n", __func__);
1057 		return -ENOMEM;
1058 	}
1059 	memset(ndsp, 0, sizeof(struct dsp));
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 	ndsp->tone.tl.function = (void *)dsp_tone_timeout;
1093 	ndsp->tone.tl.data = (long) ndsp;
1094 	init_timer(&ndsp->tone.tl);
1095 
1096 	if (dtmfthreshold < 20 || dtmfthreshold > 500)
1097 		dtmfthreshold = 200;
1098 	ndsp->dtmf.treshold = dtmfthreshold*10000;
1099 
1100 	/* init pipeline append to list */
1101 	spin_lock_irqsave(&dsp_lock, flags);
1102 	dsp_pipeline_init(&ndsp->pipeline);
1103 	list_add_tail(&ndsp->list, &dsp_ilist);
1104 	spin_unlock_irqrestore(&dsp_lock, flags);
1105 
1106 	return 0;
1107 }
1108 
1109 
1110 static struct Bprotocol DSP = {
1111 	.Bprotocols = (1 << (ISDN_P_B_L2DSP & ISDN_P_B_MASK))
1112 		| (1 << (ISDN_P_B_L2DSPHDLC & ISDN_P_B_MASK)),
1113 	.name = "dsp",
1114 	.create = dspcreate
1115 };
1116 
1117 static int dsp_init(void)
1118 {
1119 	int err;
1120 	int tics;
1121 
1122 	printk(KERN_INFO "DSP modul %s\n", mISDN_dsp_revision);
1123 
1124 	dsp_options = options;
1125 	dsp_debug = debug;
1126 
1127 	/* set packet size */
1128 	dsp_poll = poll;
1129 	if (dsp_poll) {
1130 		if (dsp_poll > MAX_POLL) {
1131 			printk(KERN_ERR "%s: Wrong poll value (%d), use %d "
1132 				"maximum.\n", __func__, poll, MAX_POLL);
1133 			err = -EINVAL;
1134 			return err;
1135 		}
1136 		if (dsp_poll < 8) {
1137 			printk(KERN_ERR "%s: Wrong poll value (%d), use 8 "
1138 				"minimum.\n", __func__, dsp_poll);
1139 			err = -EINVAL;
1140 			return err;
1141 		}
1142 		dsp_tics = poll * HZ / 8000;
1143 		if (dsp_tics * 8000 != poll * HZ) {
1144 			printk(KERN_INFO "mISDN_dsp: Cannot clock every %d "
1145 				"samples (0,125 ms). It is not a multiple of "
1146 				"%d HZ.\n", poll, HZ);
1147 			err = -EINVAL;
1148 			return err;
1149 		}
1150 	} else {
1151 		poll = 8;
1152 		while (poll <= MAX_POLL) {
1153 			tics = (poll * HZ) / 8000;
1154 			if (tics * 8000 == poll * HZ) {
1155 				dsp_tics = tics;
1156 				dsp_poll = poll;
1157 				if (poll >= 64)
1158 					break;
1159 			}
1160 			poll++;
1161 		}
1162 	}
1163 	if (dsp_poll == 0) {
1164 		printk(KERN_INFO "mISDN_dsp: There is no multiple of kernel "
1165 			"clock that equals exactly the duration of 8-256 "
1166 			"samples. (Choose kernel clock speed like 100, 250, "
1167 			"300, 1000)\n");
1168 		err = -EINVAL;
1169 		return err;
1170 	}
1171 	printk(KERN_INFO "mISDN_dsp: DSP clocks every %d samples. This equals "
1172 		"%d jiffies.\n", dsp_poll, dsp_tics);
1173 
1174 	spin_lock_init(&dsp_lock);
1175 	INIT_LIST_HEAD(&dsp_ilist);
1176 	INIT_LIST_HEAD(&conf_ilist);
1177 
1178 	/* init conversion tables */
1179 	dsp_audio_generate_law_tables();
1180 	dsp_silence = (dsp_options&DSP_OPT_ULAW) ? 0xff : 0x2a;
1181 	dsp_audio_law_to_s32 = (dsp_options&DSP_OPT_ULAW) ?
1182 		dsp_audio_ulaw_to_s32 : dsp_audio_alaw_to_s32;
1183 	dsp_audio_generate_s2law_table();
1184 	dsp_audio_generate_seven();
1185 	dsp_audio_generate_mix_table();
1186 	if (dsp_options & DSP_OPT_ULAW)
1187 		dsp_audio_generate_ulaw_samples();
1188 	dsp_audio_generate_volume_changes();
1189 
1190 	err = dsp_pipeline_module_init();
1191 	if (err) {
1192 		printk(KERN_ERR "mISDN_dsp: Can't initialize pipeline, "
1193 			"error(%d)\n", err);
1194 		return err;
1195 	}
1196 
1197 	err = mISDN_register_Bprotocol(&DSP);
1198 	if (err) {
1199 		printk(KERN_ERR "Can't register %s error(%d)\n", DSP.name, err);
1200 		return err;
1201 	}
1202 
1203 	/* set sample timer */
1204 	dsp_spl_tl.function = (void *)dsp_cmx_send;
1205 	dsp_spl_tl.data = 0;
1206 	init_timer(&dsp_spl_tl);
1207 	dsp_spl_tl.expires = jiffies + dsp_tics;
1208 	dsp_spl_jiffies = dsp_spl_tl.expires;
1209 	add_timer(&dsp_spl_tl);
1210 
1211 	return 0;
1212 }
1213 
1214 
1215 static void dsp_cleanup(void)
1216 {
1217 	mISDN_unregister_Bprotocol(&DSP);
1218 
1219 	if (timer_pending(&dsp_spl_tl))
1220 		del_timer(&dsp_spl_tl);
1221 
1222 	if (!list_empty(&dsp_ilist)) {
1223 		printk(KERN_ERR "mISDN_dsp: Audio DSP object inst list not "
1224 			"empty.\n");
1225 	}
1226 	if (!list_empty(&conf_ilist)) {
1227 		printk(KERN_ERR "mISDN_dsp: Conference list not empty. Not "
1228 			"all memory freed.\n");
1229 	}
1230 
1231 	dsp_pipeline_module_exit();
1232 }
1233 
1234 module_init(dsp_init);
1235 module_exit(dsp_cleanup);
1236 
1237