drivers/isdn/mISDN/dsp_core.c

   1 /*
   2  * Author       Andreas Eversberg (jolly@eversberg.eu)
   3  * Based on source code structure by
   4  *              Karsten Keil (keil@isdn4linux.de)
   5  *
   6  *              This file is (c) under GNU PUBLIC LICENSE
   7  *              For changes and modifications please read
   8  *              ../../../Documentation/isdn/mISDN.cert
   9  *
  10  * Thanks to    Karsten Keil (great drivers)
  11  *              Cologne Chip (great chips)
  12  *
  13  * This module does:
  14  *              Real-time tone generation
  15  *              DTMF detection
  16  *              Real-time cross-connection and conferrence
  17  *              Compensate jitter due to system load and hardware fault.
  18  *              All features are done in kernel space and will be realized
  19  *              using hardware, if available and supported by chip set.
  20  *              Blowfish encryption/decryption
  21  */
  22
  23 /* STRUCTURE:
  24  *
  25  * The dsp module provides layer 2 for b-channels (64kbit). It provides
  26  * transparent audio forwarding with special digital signal processing:
  27  *
  28  * - (1) generation of tones
  29  * - (2) detection of dtmf tones
  30  * - (3) crossconnecting and conferences (clocking)
  31  * - (4) echo generation for delay test
  32  * - (5) volume control
  33  * - (6) disable receive data
  34  * - (7) pipeline
  35  * - (8) encryption/decryption
  36  *
  37  * Look:
  38  *             TX            RX
  39  *         ------upper layer------
  40  *             |             ^
  41  *             |             |(6)
  42  *             v             |
  43  *       +-----+-------------+-----+
  44  *       |(3)(4)                   |
  45  *       |           CMX           |
  46  *       |                         |
  47  *       |           +-------------+
  48  *       |           |       ^
  49  *       |           |       |
  50  *       |+---------+|  +----+----+
  51  *       ||(1)      ||  |(2)      |
  52  *       ||         ||  |         |
  53  *       ||  Tones  ||  |  DTMF   |
  54  *       ||         ||  |         |
  55  *       ||         ||  |         |
  56  *       |+----+----+|  +----+----+
  57  *       +-----+-----+       ^
  58  *             |             |
  59  *             v             |
  60  *        +----+----+   +----+----+
  61  *        |(5)      |   |(5)      |
  62  *        |         |   |         |
  63  *        |TX Volume|   |RX Volume|
  64  *        |         |   |         |
  65  *        |         |   |         |
  66  *        +----+----+   +----+----+
  67  *             |             ^
  68  *             |             |
  69  *             v             |
  70  *        +----+-------------+----+
  71  *        |(7)                    |
  72  *        |                       |
  73  *        |  Pipeline Processing  |
  74  *        |                       |
  75  *        |                       |
  76  *        +----+-------------+----+
  77  *             |             ^
  78  *             |             |
  79  *             v             |
  80  *        +----+----+   +----+----+
  81  *        |(8)      |   |(8)      |
  82  *        |         |   |         |
  83  *        | Encrypt |   | Decrypt |
  84  *        |         |   |         |
  85  *        |         |   |         |
  86  *        +----+----+   +----+----+
  87  *             |             ^
  88  *             |             |
  89  *             v             |
  90  *         ------card  layer------
  91  *             TX            RX
  92  *
  93  * Above you can see the logical data flow. If software is used to do the
  94  * process, it is actually the real data flow. If hardware is used, data
  95  * may not flow, but hardware commands to the card, to provide the data flow
  96  * as shown.
  97  *
  98  * NOTE: The channel must be activated in order to make dsp work, even if
  99  * no data flow to the upper layer is intended. Activation can be done
 100  * after and before controlling the setting using PH_CONTROL requests.
 101  *
 102  * DTMF: Will be detected by hardware if possible. It is done before CMX
 103  * processing.
 104  *
 105  * Tones: Will be generated via software if endless looped audio fifos are
 106  * not supported by hardware. Tones will override all data from CMX.
 107  * It is not required to join a conference to use tones at any time.
 108  *
 109  * CMX: Is transparent when not used. When it is used, it will do
 110  * crossconnections and conferences via software if not possible through
 111  * hardware. If hardware capability is available, hardware is used.
 112  *
 113  * Echo: Is generated by CMX and is used to check performance of hard and
 114  * software CMX.
 115  *
 116  * The CMX has special functions for conferences with one, two and more
 117  * members. It will allow different types of data flow. Receive and transmit
 118  * data to/form upper layer may be swithed on/off individually without losing
 119  * features of CMX, Tones and DTMF.
 120  *
 121  * Echo Cancellation: Sometimes we like to cancel echo from the interface.
 122  * Note that a VoIP call may not have echo caused by the IP phone. The echo
 123  * is generated by the telephone line connected to it. Because the delay
 124  * is high, it becomes an echo. RESULT: Echo Cachelation is required if
 125  * both echo AND delay is applied to an interface.
 126  * Remember that software CMX always generates a more or less delay.
 127  *
 128  * If all used features can be realized in hardware, and if transmit and/or
 129  * receive data ist disabled, the card may not send/receive any data at all.
 130  * Not receiving is useful if only announcements are played. Not sending is
 131  * useful if an answering machine records audio. Not sending and receiving is
 132  * useful during most states of the call. If supported by hardware, tones
 133  * will be played without cpu load. Small PBXs and NT-Mode applications will
 134  * not need expensive hardware when processing calls.
 135  *
 136  *
 137  * LOCKING:
 138  *
 139  * When data is received from upper or lower layer (card), the complete dsp
 140  * module is locked by a global lock.  This lock MUST lock irq, because it
 141  * must lock timer events by DSP poll timer.
 142  * When data is ready to be transmitted down, the data is queued and sent
 143  * outside lock and timer event.
 144  * PH_CONTROL must not change any settings, join or split conference members
 145  * during process of data.
 146  *
 147  * HDLC:
 148  *
 149  * It works quite the same as transparent, except that HDLC data is forwarded
 150  * to all other conference members if no hardware bridging is possible.
 151  * Send data will be writte to sendq. Sendq will be sent if confirm is received.
 152  * Conference cannot join, if one member is not hdlc.
 153  *
 154  */
 155
 156 #include <linux/delay.h>
 157 #include <linux/gfp.h>
 158 #include <linux/mISDNif.h>
 159 #include <linux/mISDNdsp.h>
 160 #include <linux/module.h>
 161 #include <linux/vmalloc.h>
 162 #include "core.h"
 163 #include "dsp.h"
 164
 165 static const char *mISDN_dsp_revision = "2.0";
 166
 167 static int debug;
 168 static int options;
 169 static int poll;
 170 static int dtmfthreshold = 100;
 171
 172 MODULE_AUTHOR("Andreas Eversberg");
 173 module_param(debug, uint, S_IRUGO | S_IWUSR);
 174 module_param(options, uint, S_IRUGO | S_IWUSR);
 175 module_param(poll, uint, S_IRUGO | S_IWUSR);
 176 module_param(dtmfthreshold, uint, S_IRUGO | S_IWUSR);
 177 MODULE_LICENSE("GPL");
 178
 179 /*int spinnest = 0;*/
 180
 181 spinlock_t dsp_lock; /* global dsp lock */
 182 struct list_head dsp_ilist;
 183 struct list_head conf_ilist;
 184 int dsp_debug;
 185 int dsp_options;
 186 int dsp_poll, dsp_tics;
 187
 188 /* check if rx may be turned off or must be turned on */
 189 static void
 190 dsp_rx_off_member(struct dsp *dsp)
 191 {
 192         struct mISDN_ctrl_req   cq;
 193         int rx_off = 1;
 194
 195         memset(&cq, 0, sizeof(cq));
 196
 197         if (!dsp->features_rx_off)
 198                 return;
 199
 200         /* not disabled */
 201         if (!dsp->rx_disabled)
 202                 rx_off = 0;
 203         /* software dtmf */
 204         else if (dsp->dtmf.software)
 205                 rx_off = 0;
 206         /* echo in software */
 207         else if (dsp->echo.software)
 208                 rx_off = 0;
 209         /* bridge in software */
 210         else if (dsp->conf && dsp->conf->software)
 211                 rx_off = 0;
 212         /* data is not required by user space and not required
 213          * for echo dtmf detection, soft-echo, soft-bridging */
 214
 215         if (rx_off == dsp->rx_is_off)
 216                 return;
 217
 218         if (!dsp->ch.peer) {
 219                 if (dsp_debug & DEBUG_DSP_CORE)
 220                         printk(KERN_DEBUG "%s: no peer, no rx_off\n",
 221                                __func__);
 222                 return;
 223         }
 224         cq.op = MISDN_CTRL_RX_OFF;
 225         cq.p1 = rx_off;
 226         if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
 227                 printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
 228                        __func__);
 229                 return;
 230         }
 231         dsp->rx_is_off = rx_off;
 232         if (dsp_debug & DEBUG_DSP_CORE)
 233                 printk(KERN_DEBUG "%s: %s set rx_off = %d\n",
 234                        __func__, dsp->name, rx_off);
 235 }
 236 static void
 237 dsp_rx_off(struct dsp *dsp)
 238 {
 239         struct dsp_conf_member  *member;
 240
 241         if (dsp_options & DSP_OPT_NOHARDWARE)
 242                 return;
 243
 244         /* no conf */
 245         if (!dsp->conf) {
 246                 dsp_rx_off_member(dsp);
 247                 return;
 248         }
 249         /* check all members in conf */
 250         list_for_each_entry(member, &dsp->conf->mlist, list) {
 251                 dsp_rx_off_member(member->dsp);
 252         }
 253 }
 254
 255 /* enable "fill empty" feature */
 256 static void
 257 dsp_fill_empty(struct dsp *dsp)
 258 {
 259         struct mISDN_ctrl_req   cq;
 260
 261         memset(&cq, 0, sizeof(cq));
 262
 263         if (!dsp->ch.peer) {
 264                 if (dsp_debug & DEBUG_DSP_CORE)
 265                         printk(KERN_DEBUG "%s: no peer, no fill_empty\n",
 266                                __func__);
 267                 return;
 268         }
 269         cq.op = MISDN_CTRL_FILL_EMPTY;
 270         cq.p1 = 1;
 271         cq.p2 = dsp_silence;
 272         if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
 273                 printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
 274                        __func__);
 275                 return;
 276         }
 277         if (dsp_debug & DEBUG_DSP_CORE)
 278                 printk(KERN_DEBUG "%s: %s set fill_empty = 1\n",
 279                        __func__, dsp->name);
 280 }
 281
 282 static int
 283 dsp_control_req(struct dsp *dsp, struct mISDNhead *hh, struct sk_buff *skb)
 284 {
 285         struct sk_buff  *nskb;
 286         int ret = 0;
 287         int cont;
 288         u8 *data;
 289         int len;
 290
 291         if (skb->len < sizeof(int))
 292                 printk(KERN_ERR "%s: PH_CONTROL message too short\n", __func__);
 293         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 mebers\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 mebers\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         int             err = 0;
 957
 958         if (debug & DEBUG_DSP_CTRL)
 959                 printk(KERN_DEBUG "%s:(%x)\n", __func__, cmd);
 960
 961         switch (cmd) {
 962         case OPEN_CHANNEL:
 963                 break;
 964         case CLOSE_CHANNEL:
 965                 if (dsp->ch.peer)
 966                         dsp->ch.peer->ctrl(dsp->ch.peer, CLOSE_CHANNEL, NULL);
 967
 968                 /* wait until workqueue has finished,
 969                  * must lock here, or we may hit send-process currently
 970                  * queueing. */
 971                 spin_lock_irqsave(&dsp_lock, flags);
 972                 dsp->b_active = 0;
 973                 spin_unlock_irqrestore(&dsp_lock, flags);
 974                 /* MUST not be locked, because it waits until queue is done. */
 975                 cancel_work_sync(&dsp->workq);
 976                 spin_lock_irqsave(&dsp_lock, flags);
 977                 if (timer_pending(&dsp->tone.tl))
 978                         del_timer(&dsp->tone.tl);
 979                 skb_queue_purge(&dsp->sendq);
 980                 if (dsp_debug & DEBUG_DSP_CTRL)
 981                         printk(KERN_DEBUG "%s: releasing member %s\n",
 982                                __func__, dsp->name);
 983                 dsp->b_active = 0;
 984                 dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be called
 985                                          here */
 986                 dsp_pipeline_destroy(&dsp->pipeline);
 987
 988                 if (dsp_debug & DEBUG_DSP_CTRL)
 989                         printk(KERN_DEBUG "%s: remove & destroy object %s\n",
 990                                __func__, dsp->name);
 991                 list_del(&dsp->list);
 992                 spin_unlock_irqrestore(&dsp_lock, flags);
 993
 994                 if (dsp_debug & DEBUG_DSP_CTRL)
 995                         printk(KERN_DEBUG "%s: dsp instance released\n",
 996                                __func__);
 997                 vfree(dsp);
 998                 module_put(THIS_MODULE);
 999                 break;
1000         }
1001         return err;
1002 }
1003
1004 static void
1005 dsp_send_bh(struct work_struct *work)
1006 {
1007         struct dsp *dsp = container_of(work, struct dsp, workq);
1008         struct sk_buff *skb;
1009         struct mISDNhead        *hh;
1010
1011         if (dsp->hdlc && dsp->data_pending)
1012                 return; /* wait until data has been acknowledged */
1013
1014         /* send queued data */
1015         while ((skb = skb_dequeue(&dsp->sendq))) {
1016                 /* in locked date, we must have still data in queue */
1017                 if (dsp->data_pending) {
1018                         if (dsp_debug & DEBUG_DSP_CORE)
1019                                 printk(KERN_DEBUG "%s: fifo full %s, this is "
1020                                        "no bug!\n", __func__, dsp->name);
1021                         /* flush transparent data, if not acked */
1022                         dev_kfree_skb(skb);
1023                         continue;
1024                 }
1025                 hh = mISDN_HEAD_P(skb);
1026                 if (hh->prim == DL_DATA_REQ) {
1027                         /* send packet up */
1028                         if (dsp->up) {
1029                                 if (dsp->up->send(dsp->up, skb))
1030                                         dev_kfree_skb(skb);
1031                         } else
1032                                 dev_kfree_skb(skb);
1033                 } else {
1034                         /* send packet down */
1035                         if (dsp->ch.peer) {
1036                                 dsp->data_pending = 1;
1037                                 if (dsp->ch.recv(dsp->ch.peer, skb)) {
1038                                         dev_kfree_skb(skb);
1039                                         dsp->data_pending = 0;
1040                                 }
1041                         } else
1042                                 dev_kfree_skb(skb);
1043                 }
1044         }
1045 }
1046
1047 static int
1048 dspcreate(struct channel_req *crq)
1049 {
1050         struct dsp              *ndsp;
1051         u_long          flags;
1052
1053         if (crq->protocol != ISDN_P_B_L2DSP
1054             && crq->protocol != ISDN_P_B_L2DSPHDLC)
1055                 return -EPROTONOSUPPORT;
1056         ndsp = vzalloc(sizeof(struct dsp));
1057         if (!ndsp) {
1058                 printk(KERN_ERR "%s: vmalloc struct dsp failed\n", __func__);
1059                 return -ENOMEM;
1060         }
1061         if (dsp_debug & DEBUG_DSP_CTRL)
1062                 printk(KERN_DEBUG "%s: creating new dsp instance\n", __func__);
1063
1064         /* default enabled */
1065         INIT_WORK(&ndsp->workq, (void *)dsp_send_bh);
1066         skb_queue_head_init(&ndsp->sendq);
1067         ndsp->ch.send = dsp_function;
1068         ndsp->ch.ctrl = dsp_ctrl;
1069         ndsp->up = crq->ch;
1070         crq->ch = &ndsp->ch;
1071         if (crq->protocol == ISDN_P_B_L2DSP) {
1072                 crq->protocol = ISDN_P_B_RAW;
1073                 ndsp->hdlc = 0;
1074         } else {
1075                 crq->protocol = ISDN_P_B_HDLC;
1076                 ndsp->hdlc = 1;
1077         }
1078         if (!try_module_get(THIS_MODULE))
1079                 printk(KERN_WARNING "%s:cannot get module\n",
1080                        __func__);
1081
1082         sprintf(ndsp->name, "DSP_C%x(0x%p)",
1083                 ndsp->up->st->dev->id + 1, ndsp);
1084         /* set frame size to start */
1085         ndsp->features.hfc_id = -1; /* current PCM id */
1086         ndsp->features.pcm_id = -1; /* current PCM id */
1087         ndsp->pcm_slot_rx = -1; /* current CPM slot */
1088         ndsp->pcm_slot_tx = -1;
1089         ndsp->pcm_bank_rx = -1;
1090         ndsp->pcm_bank_tx = -1;
1091         ndsp->hfc_conf = -1; /* current conference number */
1092         /* set tone timer */
1093         ndsp->tone.tl.function = (void *)dsp_tone_timeout;
1094         ndsp->tone.tl.data = (long) ndsp;
1095         init_timer(&ndsp->tone.tl);
1096
1097         if (dtmfthreshold < 20 || dtmfthreshold > 500)
1098                 dtmfthreshold = 200;
1099         ndsp->dtmf.treshold = dtmfthreshold * 10000;
1100
1101         /* init pipeline append to list */
1102         spin_lock_irqsave(&dsp_lock, flags);
1103         dsp_pipeline_init(&ndsp->pipeline);
1104         list_add_tail(&ndsp->list, &dsp_ilist);
1105         spin_unlock_irqrestore(&dsp_lock, flags);
1106
1107         return 0;
1108 }
1109
1110
1111 static struct Bprotocol DSP = {
1112         .Bprotocols = (1 << (ISDN_P_B_L2DSP & ISDN_P_B_MASK))
1113         | (1 << (ISDN_P_B_L2DSPHDLC & ISDN_P_B_MASK)),
1114         .name = "dsp",
1115         .create = dspcreate
1116 };
1117
1118 static int __init dsp_init(void)
1119 {
1120         int err;
1121         int tics;
1122
1123         printk(KERN_INFO "DSP module %s\n", mISDN_dsp_revision);
1124
1125         dsp_options = options;
1126         dsp_debug = debug;
1127
1128         /* set packet size */
1129         dsp_poll = poll;
1130         if (dsp_poll) {
1131                 if (dsp_poll > MAX_POLL) {
1132                         printk(KERN_ERR "%s: Wrong poll value (%d), use %d "
1133                                "maximum.\n", __func__, poll, MAX_POLL);
1134                         err = -EINVAL;
1135                         return err;
1136                 }
1137                 if (dsp_poll < 8) {
1138                         printk(KERN_ERR "%s: Wrong poll value (%d), use 8 "
1139                                "minimum.\n", __func__, dsp_poll);
1140                         err = -EINVAL;
1141                         return err;
1142                 }
1143                 dsp_tics = poll * HZ / 8000;
1144                 if (dsp_tics * 8000 != poll * HZ) {
1145                         printk(KERN_INFO "mISDN_dsp: Cannot clock every %d "
1146                                "samples (0,125 ms). It is not a multiple of "
1147                                "%d HZ.\n", poll, HZ);
1148                         err = -EINVAL;
1149                         return err;
1150                 }
1151         } else {
1152                 poll = 8;
1153                 while (poll <= MAX_POLL) {
1154                         tics = (poll * HZ) / 8000;
1155                         if (tics * 8000 == poll * HZ) {
1156                                 dsp_tics = tics;
1157                                 dsp_poll = poll;
1158                                 if (poll >= 64)
1159                                         break;
1160                         }
1161                         poll++;
1162                 }
1163         }
1164         if (dsp_poll == 0) {
1165                 printk(KERN_INFO "mISDN_dsp: There is no multiple of kernel "
1166                        "clock that equals exactly the duration of 8-256 "
1167                        "samples. (Choose kernel clock speed like 100, 250, "
1168                        "300, 1000)\n");
1169                 err = -EINVAL;
1170                 return err;
1171         }
1172         printk(KERN_INFO "mISDN_dsp: DSP clocks every %d samples. This equals "
1173                "%d jiffies.\n", dsp_poll, dsp_tics);
1174
1175         spin_lock_init(&dsp_lock);
1176         INIT_LIST_HEAD(&dsp_ilist);
1177         INIT_LIST_HEAD(&conf_ilist);
1178
1179         /* init conversion tables */
1180         dsp_audio_generate_law_tables();
1181         dsp_silence = (dsp_options & DSP_OPT_ULAW) ? 0xff : 0x2a;
1182         dsp_audio_law_to_s32 = (dsp_options & DSP_OPT_ULAW) ?
1183                 dsp_audio_ulaw_to_s32 : dsp_audio_alaw_to_s32;
1184         dsp_audio_generate_s2law_table();
1185         dsp_audio_generate_seven();
1186         dsp_audio_generate_mix_table();
1187         if (dsp_options & DSP_OPT_ULAW)
1188                 dsp_audio_generate_ulaw_samples();
1189         dsp_audio_generate_volume_changes();
1190
1191         err = dsp_pipeline_module_init();
1192         if (err) {
1193                 printk(KERN_ERR "mISDN_dsp: Can't initialize pipeline, "
1194                        "error(%d)\n", err);
1195                 return err;
1196         }
1197
1198         err = mISDN_register_Bprotocol(&DSP);
1199         if (err) {
1200                 printk(KERN_ERR "Can't register %s error(%d)\n", DSP.name, err);
1201                 return err;
1202         }
1203
1204         /* set sample timer */
1205         dsp_spl_tl.function = (void *)dsp_cmx_send;
1206         dsp_spl_tl.data = 0;
1207         init_timer(&dsp_spl_tl);
1208         dsp_spl_tl.expires = jiffies + dsp_tics;
1209         dsp_spl_jiffies = dsp_spl_tl.expires;
1210         add_timer(&dsp_spl_tl);
1211
1212         return 0;
1213 }
1214
1215
1216 static void __exit dsp_cleanup(void)
1217 {
1218         mISDN_unregister_Bprotocol(&DSP);
1219
1220         del_timer_sync(&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);