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
163static const char *mISDN_dsp_revision = "2.0";
164
165static int debug;
166static int options;
167static int poll;
168static int dtmfthreshold = 100;
169
170MODULE_AUTHOR("Andreas Eversberg");
171module_param(debug, uint, S_IRUGO | S_IWUSR);
172module_param(options, uint, S_IRUGO | S_IWUSR);
173module_param(poll, uint, S_IRUGO | S_IWUSR);
174module_param(dtmfthreshold, uint, S_IRUGO | S_IWUSR);
175MODULE_LICENSE("GPL");
176
177/*int spinnest = 0;*/
178
179DEFINE_SPINLOCK(dsp_lock); /* global dsp lock */
180LIST_HEAD(dsp_ilist);
181LIST_HEAD(conf_ilist);
182int dsp_debug;
183int dsp_options;
184int dsp_poll, dsp_tics;
185
186/* check if rx may be turned off or must be turned on */
187static void
188dsp_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}
234static void
235dsp_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 */
254static void
255dsp_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
280static int
281dsp_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
625static void
626get_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
663static int
664dsp_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
951static int
952dsp_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
1003static void
1004dsp_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
1046static int
1047dspcreate(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
1108static 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
1115static 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
1207static 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
1225module_init(dsp_init);
1226module_exit(dsp_cleanup);
1227