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                 return -EINVAL;
 294         }
 295         cont = *((int *)skb->data);
 296         len = skb->len - sizeof(int);
 297         data = skb->data + sizeof(int);
 298
 299         switch (cont) {
 300         case DTMF_TONE_START: /* turn on DTMF */
 301                 if (dsp->hdlc) {
 302                         ret = -EINVAL;
 303                         break;
 304                 }
 305                 if (dsp_debug & DEBUG_DSP_CORE)
 306                         printk(KERN_DEBUG "%s: start dtmf\n", __func__);
 307                 if (len == sizeof(int)) {
 308                         if (dsp_debug & DEBUG_DSP_CORE)
 309                                 printk(KERN_NOTICE "changing DTMF Threshold "
 310                                        "to %d\n", *((int *)data));
 311                         dsp->dtmf.treshold = (*(int *)data) * 10000;
 312                 }
 313                 dsp->dtmf.enable = 1;
 314                 /* init goertzel */
 315                 dsp_dtmf_goertzel_init(dsp);
 316
 317                 /* check dtmf hardware */
 318                 dsp_dtmf_hardware(dsp);
 319                 dsp_rx_off(dsp);
 320                 break;
 321         case DTMF_TONE_STOP: /* turn off DTMF */
 322                 if (dsp_debug & DEBUG_DSP_CORE)
 323                         printk(KERN_DEBUG "%s: stop dtmf\n", __func__);
 324                 dsp->dtmf.enable = 0;
 325                 dsp->dtmf.hardware = 0;
 326                 dsp->dtmf.software = 0;
 327                 break;
 328         case DSP_CONF_JOIN: /* join / update conference */
 329                 if (len < sizeof(int)) {
 330                         ret = -EINVAL;
 331                         break;
 332                 }
 333                 if (*((u32 *)data) == 0)
 334                         goto conf_split;
 335                 if (dsp_debug & DEBUG_DSP_CORE)
 336                         printk(KERN_DEBUG "%s: join conference %d\n",
 337                                __func__, *((u32 *)data));
 338                 ret = dsp_cmx_conf(dsp, *((u32 *)data));
 339                 /* dsp_cmx_hardware will also be called here */
 340                 dsp_rx_off(dsp);
 341                 if (dsp_debug & DEBUG_DSP_CMX)
 342                         dsp_cmx_debug(dsp);
 343                 break;
 344         case DSP_CONF_SPLIT: /* remove from conference */
 345         conf_split:
 346                 if (dsp_debug & DEBUG_DSP_CORE)
 347                         printk(KERN_DEBUG "%s: release conference\n", __func__);
 348                 ret = dsp_cmx_conf(dsp, 0);
 349                 /* dsp_cmx_hardware will also be called here */
 350                 if (dsp_debug & DEBUG_DSP_CMX)
 351                         dsp_cmx_debug(dsp);
 352                 dsp_rx_off(dsp);
 353                 break;
 354         case DSP_TONE_PATT_ON: /* play tone */
 355                 if (dsp->hdlc) {
 356                         ret = -EINVAL;
 357                         break;
 358                 }
 359                 if (len < sizeof(int)) {
 360                         ret = -EINVAL;
 361                         break;
 362                 }
 363                 if (dsp_debug & DEBUG_DSP_CORE)
 364                         printk(KERN_DEBUG "%s: turn tone 0x%x on\n",
 365                                __func__, *((int *)skb->data));
 366                 ret = dsp_tone(dsp, *((int *)data));
 367                 if (!ret) {
 368                         dsp_cmx_hardware(dsp->conf, dsp);
 369                         dsp_rx_off(dsp);
 370                 }
 371                 if (!dsp->tone.tone)
 372                         goto tone_off;
 373                 break;
 374         case DSP_TONE_PATT_OFF: /* stop tone */
 375                 if (dsp->hdlc) {
 376                         ret = -EINVAL;
 377                         break;
 378                 }
 379                 if (dsp_debug & DEBUG_DSP_CORE)
 380                         printk(KERN_DEBUG "%s: turn tone off\n", __func__);
 381                 dsp_tone(dsp, 0);
 382                 dsp_cmx_hardware(dsp->conf, dsp);
 383                 dsp_rx_off(dsp);
 384                 /* reset tx buffers (user space data) */
 385         tone_off:
 386                 dsp->rx_W = 0;
 387                 dsp->rx_R = 0;
 388                 break;
 389         case DSP_VOL_CHANGE_TX: /* change volume */
 390                 if (dsp->hdlc) {
 391                         ret = -EINVAL;
 392                         break;
 393                 }
 394                 if (len < sizeof(int)) {
 395                         ret = -EINVAL;
 396                         break;
 397                 }
 398                 dsp->tx_volume = *((int *)data);
 399                 if (dsp_debug & DEBUG_DSP_CORE)
 400                         printk(KERN_DEBUG "%s: change tx vol to %d\n",
 401                                __func__, dsp->tx_volume);
 402                 dsp_cmx_hardware(dsp->conf, dsp);
 403                 dsp_dtmf_hardware(dsp);
 404                 dsp_rx_off(dsp);
 405                 break;
 406         case DSP_VOL_CHANGE_RX: /* change volume */
 407                 if (dsp->hdlc) {
 408                         ret = -EINVAL;
 409                         break;
 410                 }
 411                 if (len < sizeof(int)) {
 412                         ret = -EINVAL;
 413                         break;
 414                 }
 415                 dsp->rx_volume = *((int *)data);
 416                 if (dsp_debug & DEBUG_DSP_CORE)
 417                         printk(KERN_DEBUG "%s: change rx vol to %d\n",
 418                                __func__, dsp->tx_volume);
 419                 dsp_cmx_hardware(dsp->conf, dsp);
 420                 dsp_dtmf_hardware(dsp);
 421                 dsp_rx_off(dsp);
 422                 break;
 423         case DSP_ECHO_ON: /* enable echo */
 424                 dsp->echo.software = 1; /* soft echo */
 425                 if (dsp_debug & DEBUG_DSP_CORE)
 426                         printk(KERN_DEBUG "%s: enable cmx-echo\n", __func__);
 427                 dsp_cmx_hardware(dsp->conf, dsp);
 428                 dsp_rx_off(dsp);
 429                 if (dsp_debug & DEBUG_DSP_CMX)
 430                         dsp_cmx_debug(dsp);
 431                 break;
 432         case DSP_ECHO_OFF: /* disable echo */
 433                 dsp->echo.software = 0;
 434                 dsp->echo.hardware = 0;
 435                 if (dsp_debug & DEBUG_DSP_CORE)
 436                         printk(KERN_DEBUG "%s: disable cmx-echo\n", __func__);
 437                 dsp_cmx_hardware(dsp->conf, dsp);
 438                 dsp_rx_off(dsp);
 439                 if (dsp_debug & DEBUG_DSP_CMX)
 440                         dsp_cmx_debug(dsp);
 441                 break;
 442         case DSP_RECEIVE_ON: /* enable receive to user space */
 443                 if (dsp_debug & DEBUG_DSP_CORE)
 444                         printk(KERN_DEBUG "%s: enable receive to user "
 445                                "space\n", __func__);
 446                 dsp->rx_disabled = 0;
 447                 dsp_rx_off(dsp);
 448                 break;
 449         case DSP_RECEIVE_OFF: /* disable receive to user space */
 450                 if (dsp_debug & DEBUG_DSP_CORE)
 451                         printk(KERN_DEBUG "%s: disable receive to "
 452                                "user space\n", __func__);
 453                 dsp->rx_disabled = 1;
 454                 dsp_rx_off(dsp);
 455                 break;
 456         case DSP_MIX_ON: /* enable mixing of tx data */
 457                 if (dsp->hdlc) {
 458                         ret = -EINVAL;
 459                         break;
 460                 }
 461                 if (dsp_debug & DEBUG_DSP_CORE)
 462                         printk(KERN_DEBUG "%s: enable mixing of "
 463                                "tx-data with conf mebers\n", __func__);
 464                 dsp->tx_mix = 1;
 465                 dsp_cmx_hardware(dsp->conf, dsp);
 466                 dsp_rx_off(dsp);
 467                 if (dsp_debug & DEBUG_DSP_CMX)
 468                         dsp_cmx_debug(dsp);
 469                 break;
 470         case DSP_MIX_OFF: /* disable mixing of tx data */
 471                 if (dsp->hdlc) {
 472                         ret = -EINVAL;
 473                         break;
 474                 }
 475                 if (dsp_debug & DEBUG_DSP_CORE)
 476                         printk(KERN_DEBUG "%s: disable mixing of "
 477                                "tx-data with conf mebers\n", __func__);
 478                 dsp->tx_mix = 0;
 479                 dsp_cmx_hardware(dsp->conf, dsp);
 480                 dsp_rx_off(dsp);
 481                 if (dsp_debug & DEBUG_DSP_CMX)
 482                         dsp_cmx_debug(dsp);
 483                 break;
 484         case DSP_TXDATA_ON: /* enable txdata */
 485                 dsp->tx_data = 1;
 486                 if (dsp_debug & DEBUG_DSP_CORE)
 487                         printk(KERN_DEBUG "%s: enable tx-data\n", __func__);
 488                 dsp_cmx_hardware(dsp->conf, dsp);
 489                 dsp_rx_off(dsp);
 490                 if (dsp_debug & DEBUG_DSP_CMX)
 491                         dsp_cmx_debug(dsp);
 492                 break;
 493         case DSP_TXDATA_OFF: /* disable txdata */
 494                 dsp->tx_data = 0;
 495                 if (dsp_debug & DEBUG_DSP_CORE)
 496                         printk(KERN_DEBUG "%s: disable tx-data\n", __func__);
 497                 dsp_cmx_hardware(dsp->conf, dsp);
 498                 dsp_rx_off(dsp);
 499                 if (dsp_debug & DEBUG_DSP_CMX)
 500                         dsp_cmx_debug(dsp);
 501                 break;
 502         case DSP_DELAY: /* use delay algorithm instead of dynamic
 503                            jitter algorithm */
 504                 if (dsp->hdlc) {
 505                         ret = -EINVAL;
 506                         break;
 507                 }
 508                 if (len < sizeof(int)) {
 509                         ret = -EINVAL;
 510                         break;
 511                 }
 512                 dsp->cmx_delay = (*((int *)data)) << 3;
 513                 /* milliseconds to samples */
 514                 if (dsp->cmx_delay >= (CMX_BUFF_HALF >> 1))
 515                         /* clip to half of maximum usable buffer
 516                            (half of half buffer) */
 517                         dsp->cmx_delay = (CMX_BUFF_HALF >> 1) - 1;
 518                 if (dsp_debug & DEBUG_DSP_CORE)
 519                         printk(KERN_DEBUG "%s: use delay algorithm to "
 520                                "compensate jitter (%d samples)\n",
 521                                __func__, dsp->cmx_delay);
 522                 break;
 523         case DSP_JITTER: /* use dynamic jitter algorithm instead of
 524                             delay algorithm */
 525                 if (dsp->hdlc) {
 526                         ret = -EINVAL;
 527                         break;
 528                 }
 529                 dsp->cmx_delay = 0;
 530                 if (dsp_debug & DEBUG_DSP_CORE)
 531                         printk(KERN_DEBUG "%s: use jitter algorithm to "
 532                                "compensate jitter\n", __func__);
 533                 break;
 534         case DSP_TX_DEJITTER: /* use dynamic jitter algorithm for tx-buffer */
 535                 if (dsp->hdlc) {
 536                         ret = -EINVAL;
 537                         break;
 538                 }
 539                 dsp->tx_dejitter = 1;
 540                 if (dsp_debug & DEBUG_DSP_CORE)
 541                         printk(KERN_DEBUG "%s: use dejitter on TX "
 542                                "buffer\n", __func__);
 543                 break;
 544         case DSP_TX_DEJ_OFF: /* use tx-buffer without dejittering*/
 545                 if (dsp->hdlc) {
 546                         ret = -EINVAL;
 547                         break;
 548                 }
 549                 dsp->tx_dejitter = 0;
 550                 if (dsp_debug & DEBUG_DSP_CORE)
 551                         printk(KERN_DEBUG "%s: use TX buffer without "
 552                                "dejittering\n", __func__);
 553                 break;
 554         case DSP_PIPELINE_CFG:
 555                 if (dsp->hdlc) {
 556                         ret = -EINVAL;
 557                         break;
 558                 }
 559                 if (len > 0 && ((char *)data)[len - 1]) {
 560                         printk(KERN_DEBUG "%s: pipeline config string "
 561                                "is not NULL terminated!\n", __func__);
 562                         ret = -EINVAL;
 563                 } else {
 564                         dsp->pipeline.inuse = 1;
 565                         dsp_cmx_hardware(dsp->conf, dsp);
 566                         ret = dsp_pipeline_build(&dsp->pipeline,
 567                                                  len > 0 ? data : NULL);
 568                         dsp_cmx_hardware(dsp->conf, dsp);
 569                         dsp_rx_off(dsp);
 570                 }
 571                 break;
 572         case DSP_BF_ENABLE_KEY: /* turn blowfish on */
 573                 if (dsp->hdlc) {
 574                         ret = -EINVAL;
 575                         break;
 576                 }
 577                 if (len < 4 || len > 56) {
 578                         ret = -EINVAL;
 579                         break;
 580                 }
 581                 if (dsp_debug & DEBUG_DSP_CORE)
 582                         printk(KERN_DEBUG "%s: turn blowfish on (key "
 583                                "not shown)\n", __func__);
 584                 ret = dsp_bf_init(dsp, (u8 *)data, len);
 585                 /* set new cont */
 586                 if (!ret)
 587                         cont = DSP_BF_ACCEPT;
 588                 else
 589                         cont = DSP_BF_REJECT;
 590                 /* send indication if it worked to set it */
 591                 nskb = _alloc_mISDN_skb(PH_CONTROL_IND, MISDN_ID_ANY,
 592                                         sizeof(int), &cont, GFP_ATOMIC);
 593                 if (nskb) {
 594                         if (dsp->up) {
 595                                 if (dsp->up->send(dsp->up, nskb))
 596                                         dev_kfree_skb(nskb);
 597                         } else
 598                                 dev_kfree_skb(nskb);
 599                 }
 600                 if (!ret) {
 601                         dsp_cmx_hardware(dsp->conf, dsp);
 602                         dsp_dtmf_hardware(dsp);
 603                         dsp_rx_off(dsp);
 604                 }
 605                 break;
 606         case DSP_BF_DISABLE: /* turn blowfish off */
 607                 if (dsp->hdlc) {
 608                         ret = -EINVAL;
 609                         break;
 610                 }
 611                 if (dsp_debug & DEBUG_DSP_CORE)
 612                         printk(KERN_DEBUG "%s: turn blowfish off\n", __func__);
 613                 dsp_bf_cleanup(dsp);
 614                 dsp_cmx_hardware(dsp->conf, dsp);
 615                 dsp_dtmf_hardware(dsp);
 616                 dsp_rx_off(dsp);
 617                 break;
 618         default:
 619                 if (dsp_debug & DEBUG_DSP_CORE)
 620                         printk(KERN_DEBUG "%s: ctrl req %x unhandled\n",
 621                                __func__, cont);
 622                 ret = -EINVAL;
 623         }
 624         return ret;
 625 }
 626
 627 static void
 628 get_features(struct mISDNchannel *ch)
 629 {
 630         struct dsp              *dsp = container_of(ch, struct dsp, ch);
 631         struct mISDN_ctrl_req   cq;
 632
 633         if (!ch->peer) {
 634                 if (dsp_debug & DEBUG_DSP_CORE)
 635                         printk(KERN_DEBUG "%s: no peer, no features\n",
 636                                __func__);
 637                 return;
 638         }
 639         memset(&cq, 0, sizeof(cq));
 640         cq.op = MISDN_CTRL_GETOP;
 641         if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq) < 0) {
 642                 printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
 643                        __func__);
 644                 return;
 645         }
 646         if (cq.op & MISDN_CTRL_RX_OFF)
 647                 dsp->features_rx_off = 1;
 648         if (cq.op & MISDN_CTRL_FILL_EMPTY)
 649                 dsp->features_fill_empty = 1;
 650         if (dsp_options & DSP_OPT_NOHARDWARE)
 651                 return;
 652         if ((cq.op & MISDN_CTRL_HW_FEATURES_OP)) {
 653                 cq.op = MISDN_CTRL_HW_FEATURES;
 654                 *((u_long *)&cq.p1) = (u_long)&dsp->features;
 655                 if (ch->peer->ctrl(ch->peer, CONTROL_CHANNEL, &cq)) {
 656                         printk(KERN_DEBUG "%s: 2nd CONTROL_CHANNEL failed\n",
 657                                __func__);
 658                 }
 659         } else
 660                 if (dsp_debug & DEBUG_DSP_CORE)
 661                         printk(KERN_DEBUG "%s: features not supported for %s\n",
 662                                __func__, dsp->name);
 663 }
 664
 665 static int
 666 dsp_function(struct mISDNchannel *ch,  struct sk_buff *skb)
 667 {
 668         struct dsp              *dsp = container_of(ch, struct dsp, ch);
 669         struct mISDNhead        *hh;
 670         int                     ret = 0;
 671         u8                      *digits = NULL;
 672         u_long                  flags;
 673
 674         hh = mISDN_HEAD_P(skb);
 675         switch (hh->prim) {
 676                 /* FROM DOWN */
 677         case (PH_DATA_CNF):
 678                 dsp->data_pending = 0;
 679                 /* trigger next hdlc frame, if any */
 680                 if (dsp->hdlc) {
 681                         spin_lock_irqsave(&dsp_lock, flags);
 682                         if (dsp->b_active)
 683                                 schedule_work(&dsp->workq);
 684                         spin_unlock_irqrestore(&dsp_lock, flags);
 685                 }
 686                 break;
 687         case (PH_DATA_IND):
 688         case (DL_DATA_IND):
 689                 if (skb->len < 1) {
 690                         ret = -EINVAL;
 691                         break;
 692                 }
 693                 if (dsp->rx_is_off) {
 694                         if (dsp_debug & DEBUG_DSP_CORE)
 695                                 printk(KERN_DEBUG "%s: rx-data during rx_off"
 696                                        " for %s\n",
 697                                        __func__, dsp->name);
 698                 }
 699                 if (dsp->hdlc) {
 700                         /* hdlc */
 701                         spin_lock_irqsave(&dsp_lock, flags);
 702                         dsp_cmx_hdlc(dsp, skb);
 703                         spin_unlock_irqrestore(&dsp_lock, flags);
 704                         if (dsp->rx_disabled) {
 705                                 /* if receive is not allowed */
 706                                 break;
 707                         }
 708                         hh->prim = DL_DATA_IND;
 709                         if (dsp->up)
 710                                 return dsp->up->send(dsp->up, skb);
 711                         break;
 712                 }
 713
 714                 spin_lock_irqsave(&dsp_lock, flags);
 715
 716                 /* decrypt if enabled */
 717                 if (dsp->bf_enable)
 718                         dsp_bf_decrypt(dsp, skb->data, skb->len);
 719                 /* pipeline */
 720                 if (dsp->pipeline.inuse)
 721                         dsp_pipeline_process_rx(&dsp->pipeline, skb->data,
 722                                                 skb->len, hh->id);
 723                 /* change volume if requested */
 724                 if (dsp->rx_volume)
 725                         dsp_change_volume(skb, dsp->rx_volume);
 726                 /* check if dtmf soft decoding is turned on */
 727                 if (dsp->dtmf.software) {
 728                         digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
 729                                                           skb->len, (dsp_options & DSP_OPT_ULAW) ? 1 : 0);
 730                 }
 731                 /* we need to process receive data if software */
 732                 if (dsp->conf && dsp->conf->software) {
 733                         /* process data from card at cmx */
 734                         dsp_cmx_receive(dsp, skb);
 735                 }
 736
 737                 spin_unlock_irqrestore(&dsp_lock, flags);
 738
 739                 /* send dtmf result, if any */
 740                 if (digits) {
 741                         while (*digits) {
 742                                 int k;
 743                                 struct sk_buff *nskb;
 744                                 if (dsp_debug & DEBUG_DSP_DTMF)
 745                                         printk(KERN_DEBUG "%s: digit"
 746                                                "(%c) to layer %s\n",
 747                                                __func__, *digits, dsp->name);
 748                                 k = *digits | DTMF_TONE_VAL;
 749                                 nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
 750                                                         MISDN_ID_ANY, sizeof(int), &k,
 751                                                         GFP_ATOMIC);
 752                                 if (nskb) {
 753                                         if (dsp->up) {
 754                                                 if (dsp->up->send(
 755                                                             dsp->up, nskb))
 756                                                         dev_kfree_skb(nskb);
 757                                         } else
 758                                                 dev_kfree_skb(nskb);
 759                                 }
 760                                 digits++;
 761                         }
 762                 }
 763                 if (dsp->rx_disabled) {
 764                         /* if receive is not allowed */
 765                         break;
 766                 }
 767                 hh->prim = DL_DATA_IND;
 768                 if (dsp->up)
 769                         return dsp->up->send(dsp->up, skb);
 770                 break;
 771         case (PH_CONTROL_IND):
 772                 if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
 773                         printk(KERN_DEBUG "%s: PH_CONTROL INDICATION "
 774                                "received: %x (len %d) %s\n", __func__,
 775                                hh->id, skb->len, dsp->name);
 776                 switch (hh->id) {
 777                 case (DTMF_HFC_COEF): /* getting coefficients */
 778                         if (!dsp->dtmf.hardware) {
 779                                 if (dsp_debug & DEBUG_DSP_DTMFCOEFF)
 780                                         printk(KERN_DEBUG "%s: ignoring DTMF "
 781                                                "coefficients from HFC\n",
 782                                                __func__);
 783                                 break;
 784                         }
 785                         digits = dsp_dtmf_goertzel_decode(dsp, skb->data,
 786                                                           skb->len, 2);
 787                         while (*digits) {
 788                                 int k;
 789                                 struct sk_buff *nskb;
 790                                 if (dsp_debug & DEBUG_DSP_DTMF)
 791                                         printk(KERN_DEBUG "%s: digit"
 792                                                "(%c) to layer %s\n",
 793                                                __func__, *digits, dsp->name);
 794                                 k = *digits | DTMF_TONE_VAL;
 795                                 nskb = _alloc_mISDN_skb(PH_CONTROL_IND,
 796                                                         MISDN_ID_ANY, sizeof(int), &k,
 797                                                         GFP_ATOMIC);
 798                                 if (nskb) {
 799                                         if (dsp->up) {
 800                                                 if (dsp->up->send(
 801                                                             dsp->up, nskb))
 802                                                         dev_kfree_skb(nskb);
 803                                         } else
 804                                                 dev_kfree_skb(nskb);
 805                                 }
 806                                 digits++;
 807                         }
 808                         break;
 809                 case (HFC_VOL_CHANGE_TX): /* change volume */
 810                         if (skb->len != sizeof(int)) {
 811                                 ret = -EINVAL;
 812                                 break;
 813                         }
 814                         spin_lock_irqsave(&dsp_lock, flags);
 815                         dsp->tx_volume = *((int *)skb->data);
 816                         if (dsp_debug & DEBUG_DSP_CORE)
 817                                 printk(KERN_DEBUG "%s: change tx volume to "
 818                                        "%d\n", __func__, dsp->tx_volume);
 819                         dsp_cmx_hardware(dsp->conf, dsp);
 820                         dsp_dtmf_hardware(dsp);
 821                         dsp_rx_off(dsp);
 822                         spin_unlock_irqrestore(&dsp_lock, flags);
 823                         break;
 824                 default:
 825                         if (dsp_debug & DEBUG_DSP_CORE)
 826                                 printk(KERN_DEBUG "%s: ctrl ind %x unhandled "
 827                                        "%s\n", __func__, hh->id, dsp->name);
 828                         ret = -EINVAL;
 829                 }
 830                 break;
 831         case (PH_ACTIVATE_IND):
 832         case (PH_ACTIVATE_CNF):
 833                 if (dsp_debug & DEBUG_DSP_CORE)
 834                         printk(KERN_DEBUG "%s: b_channel is now active %s\n",
 835                                __func__, dsp->name);
 836                 /* bchannel now active */
 837                 spin_lock_irqsave(&dsp_lock, flags);
 838                 dsp->b_active = 1;
 839                 dsp->data_pending = 0;
 840                 dsp->rx_init = 1;
 841                 /* rx_W and rx_R will be adjusted on first frame */
 842                 dsp->rx_W = 0;
 843                 dsp->rx_R = 0;
 844                 memset(dsp->rx_buff, 0, sizeof(dsp->rx_buff));
 845                 dsp_cmx_hardware(dsp->conf, dsp);
 846                 dsp_dtmf_hardware(dsp);
 847                 dsp_rx_off(dsp);
 848                 spin_unlock_irqrestore(&dsp_lock, flags);
 849                 if (dsp_debug & DEBUG_DSP_CORE)
 850                         printk(KERN_DEBUG "%s: done with activation, sending "
 851                                "confirm to user space. %s\n", __func__,
 852                                dsp->name);
 853                 /* send activation to upper layer */
 854                 hh->prim = DL_ESTABLISH_CNF;
 855                 if (dsp->up)
 856                         return dsp->up->send(dsp->up, skb);
 857                 break;
 858         case (PH_DEACTIVATE_IND):
 859         case (PH_DEACTIVATE_CNF):
 860                 if (dsp_debug & DEBUG_DSP_CORE)
 861                         printk(KERN_DEBUG "%s: b_channel is now inactive %s\n",
 862                                __func__, dsp->name);
 863                 /* bchannel now inactive */
 864                 spin_lock_irqsave(&dsp_lock, flags);
 865                 dsp->b_active = 0;
 866                 dsp->data_pending = 0;
 867                 dsp_cmx_hardware(dsp->conf, dsp);
 868                 dsp_rx_off(dsp);
 869                 spin_unlock_irqrestore(&dsp_lock, flags);
 870                 hh->prim = DL_RELEASE_CNF;
 871                 if (dsp->up)
 872                         return dsp->up->send(dsp->up, skb);
 873                 break;
 874                 /* FROM UP */
 875         case (DL_DATA_REQ):
 876         case (PH_DATA_REQ):
 877                 if (skb->len < 1) {
 878                         ret = -EINVAL;
 879                         break;
 880                 }
 881                 if (dsp->hdlc) {
 882                         /* hdlc */
 883                         if (!dsp->b_active) {
 884                                 ret = -EIO;
 885                                 break;
 886                         }
 887                         hh->prim = PH_DATA_REQ;
 888                         spin_lock_irqsave(&dsp_lock, flags);
 889                         skb_queue_tail(&dsp->sendq, skb);
 890                         schedule_work(&dsp->workq);
 891                         spin_unlock_irqrestore(&dsp_lock, flags);
 892                         return 0;
 893                 }
 894                 /* send data to tx-buffer (if no tone is played) */
 895                 if (!dsp->tone.tone) {
 896                         spin_lock_irqsave(&dsp_lock, flags);
 897                         dsp_cmx_transmit(dsp, skb);
 898                         spin_unlock_irqrestore(&dsp_lock, flags);
 899                 }
 900                 break;
 901         case (PH_CONTROL_REQ):
 902                 spin_lock_irqsave(&dsp_lock, flags);
 903                 ret = dsp_control_req(dsp, hh, skb);
 904                 spin_unlock_irqrestore(&dsp_lock, flags);
 905                 break;
 906         case (DL_ESTABLISH_REQ):
 907         case (PH_ACTIVATE_REQ):
 908                 if (dsp_debug & DEBUG_DSP_CORE)
 909                         printk(KERN_DEBUG "%s: activating b_channel %s\n",
 910                                __func__, dsp->name);
 911                 if (dsp->dtmf.hardware || dsp->dtmf.software)
 912                         dsp_dtmf_goertzel_init(dsp);
 913                 get_features(ch);
 914                 /* enable fill_empty feature */
 915                 if (dsp->features_fill_empty)
 916                         dsp_fill_empty(dsp);
 917                 /* send ph_activate */
 918                 hh->prim = PH_ACTIVATE_REQ;
 919                 if (ch->peer)
 920                         return ch->recv(ch->peer, skb);
 921                 break;
 922         case (DL_RELEASE_REQ):
 923         case (PH_DEACTIVATE_REQ):
 924                 if (dsp_debug & DEBUG_DSP_CORE)
 925                         printk(KERN_DEBUG "%s: releasing b_channel %s\n",
 926                                __func__, dsp->name);
 927                 spin_lock_irqsave(&dsp_lock, flags);
 928                 dsp->tone.tone = 0;
 929                 dsp->tone.hardware = 0;
 930                 dsp->tone.software = 0;
 931                 if (timer_pending(&dsp->tone.tl))
 932                         del_timer(&dsp->tone.tl);
 933                 if (dsp->conf)
 934                         dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be
 935                                                  called here */
 936                 skb_queue_purge(&dsp->sendq);
 937                 spin_unlock_irqrestore(&dsp_lock, flags);
 938                 hh->prim = PH_DEACTIVATE_REQ;
 939                 if (ch->peer)
 940                         return ch->recv(ch->peer, skb);
 941                 break;
 942         default:
 943                 if (dsp_debug & DEBUG_DSP_CORE)
 944                         printk(KERN_DEBUG "%s: msg %x unhandled %s\n",
 945                                __func__, hh->prim, dsp->name);
 946                 ret = -EINVAL;
 947         }
 948         if (!ret)
 949                 dev_kfree_skb(skb);
 950         return ret;
 951 }
 952
 953 static int
 954 dsp_ctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
 955 {
 956         struct dsp              *dsp = container_of(ch, struct dsp, ch);
 957         u_long          flags;
 958         int             err = 0;
 959
 960         if (debug & DEBUG_DSP_CTRL)
 961                 printk(KERN_DEBUG "%s:(%x)\n", __func__, cmd);
 962
 963         switch (cmd) {
 964         case OPEN_CHANNEL:
 965                 break;
 966         case CLOSE_CHANNEL:
 967                 if (dsp->ch.peer)
 968                         dsp->ch.peer->ctrl(dsp->ch.peer, CLOSE_CHANNEL, NULL);
 969
 970                 /* wait until workqueue has finished,
 971                  * must lock here, or we may hit send-process currently
 972                  * queueing. */
 973                 spin_lock_irqsave(&dsp_lock, flags);
 974                 dsp->b_active = 0;
 975                 spin_unlock_irqrestore(&dsp_lock, flags);
 976                 /* MUST not be locked, because it waits until queue is done. */
 977                 cancel_work_sync(&dsp->workq);
 978                 spin_lock_irqsave(&dsp_lock, flags);
 979                 if (timer_pending(&dsp->tone.tl))
 980                         del_timer(&dsp->tone.tl);
 981                 skb_queue_purge(&dsp->sendq);
 982                 if (dsp_debug & DEBUG_DSP_CTRL)
 983                         printk(KERN_DEBUG "%s: releasing member %s\n",
 984                                __func__, dsp->name);
 985                 dsp->b_active = 0;
 986                 dsp_cmx_conf(dsp, 0); /* dsp_cmx_hardware will also be called
 987                                          here */
 988                 dsp_pipeline_destroy(&dsp->pipeline);
 989
 990                 if (dsp_debug & DEBUG_DSP_CTRL)
 991                         printk(KERN_DEBUG "%s: remove & destroy object %s\n",
 992                                __func__, dsp->name);
 993                 list_del(&dsp->list);
 994                 spin_unlock_irqrestore(&dsp_lock, flags);
 995
 996                 if (dsp_debug & DEBUG_DSP_CTRL)
 997                         printk(KERN_DEBUG "%s: dsp instance released\n",
 998                                __func__);
 999                 vfree(dsp);
1000                 module_put(THIS_MODULE);
1001                 break;
1002         }
1003         return err;
1004 }
1005
1006 static void
1007 dsp_send_bh(struct work_struct *work)
1008 {
1009         struct dsp *dsp = container_of(work, struct dsp, workq);
1010         struct sk_buff *skb;
1011         struct mISDNhead        *hh;
1012
1013         if (dsp->hdlc && dsp->data_pending)
1014                 return; /* wait until data has been acknowledged */
1015
1016         /* send queued data */
1017         while ((skb = skb_dequeue(&dsp->sendq))) {
1018                 /* in locked date, we must have still data in queue */
1019                 if (dsp->data_pending) {
1020                         if (dsp_debug & DEBUG_DSP_CORE)
1021                                 printk(KERN_DEBUG "%s: fifo full %s, this is "
1022                                        "no bug!\n", __func__, dsp->name);
1023                         /* flush transparent data, if not acked */
1024                         dev_kfree_skb(skb);
1025                         continue;
1026                 }
1027                 hh = mISDN_HEAD_P(skb);
1028                 if (hh->prim == DL_DATA_REQ) {
1029                         /* send packet up */
1030                         if (dsp->up) {
1031                                 if (dsp->up->send(dsp->up, skb))
1032                                         dev_kfree_skb(skb);
1033                         } else
1034                                 dev_kfree_skb(skb);
1035                 } else {
1036                         /* send packet down */
1037                         if (dsp->ch.peer) {
1038                                 dsp->data_pending = 1;
1039                                 if (dsp->ch.recv(dsp->ch.peer, skb)) {
1040                                         dev_kfree_skb(skb);
1041                                         dsp->data_pending = 0;
1042                                 }
1043                         } else
1044                                 dev_kfree_skb(skb);
1045                 }
1046         }
1047 }
1048
1049 static int
1050 dspcreate(struct channel_req *crq)
1051 {
1052         struct dsp              *ndsp;
1053         u_long          flags;
1054
1055         if (crq->protocol != ISDN_P_B_L2DSP
1056             && crq->protocol != ISDN_P_B_L2DSPHDLC)
1057                 return -EPROTONOSUPPORT;
1058         ndsp = vzalloc(sizeof(struct dsp));
1059         if (!ndsp) {
1060                 printk(KERN_ERR "%s: vmalloc struct dsp failed\n", __func__);
1061                 return -ENOMEM;
1062         }
1063         if (dsp_debug & DEBUG_DSP_CTRL)
1064                 printk(KERN_DEBUG "%s: creating new dsp instance\n", __func__);
1065
1066         /* default enabled */
1067         INIT_WORK(&ndsp->workq, (void *)dsp_send_bh);
1068         skb_queue_head_init(&ndsp->sendq);
1069         ndsp->ch.send = dsp_function;
1070         ndsp->ch.ctrl = dsp_ctrl;
1071         ndsp->up = crq->ch;
1072         crq->ch = &ndsp->ch;
1073         if (crq->protocol == ISDN_P_B_L2DSP) {
1074                 crq->protocol = ISDN_P_B_RAW;
1075                 ndsp->hdlc = 0;
1076         } else {
1077                 crq->protocol = ISDN_P_B_HDLC;
1078                 ndsp->hdlc = 1;
1079         }
1080         if (!try_module_get(THIS_MODULE))
1081                 printk(KERN_WARNING "%s:cannot get module\n",
1082                        __func__);
1083
1084         sprintf(ndsp->name, "DSP_C%x(0x%p)",
1085                 ndsp->up->st->dev->id + 1, ndsp);
1086         /* set frame size to start */
1087         ndsp->features.hfc_id = -1; /* current PCM id */
1088         ndsp->features.pcm_id = -1; /* current PCM id */
1089         ndsp->pcm_slot_rx = -1; /* current CPM slot */
1090         ndsp->pcm_slot_tx = -1;
1091         ndsp->pcm_bank_rx = -1;
1092         ndsp->pcm_bank_tx = -1;
1093         ndsp->hfc_conf = -1; /* current conference number */
1094         /* set tone timer */
1095         ndsp->tone.tl.function = (void *)dsp_tone_timeout;
1096         ndsp->tone.tl.data = (long) ndsp;
1097         init_timer(&ndsp->tone.tl);
1098
1099         if (dtmfthreshold < 20 || dtmfthreshold > 500)
1100                 dtmfthreshold = 200;
1101         ndsp->dtmf.treshold = dtmfthreshold * 10000;
1102
1103         /* init pipeline append to list */
1104         spin_lock_irqsave(&dsp_lock, flags);
1105         dsp_pipeline_init(&ndsp->pipeline);
1106         list_add_tail(&ndsp->list, &dsp_ilist);
1107         spin_unlock_irqrestore(&dsp_lock, flags);
1108
1109         return 0;
1110 }
1111
1112
1113 static struct Bprotocol DSP = {
1114         .Bprotocols = (1 << (ISDN_P_B_L2DSP & ISDN_P_B_MASK))
1115         | (1 << (ISDN_P_B_L2DSPHDLC & ISDN_P_B_MASK)),
1116         .name = "dsp",
1117         .create = dspcreate
1118 };
1119
1120 static int __init dsp_init(void)
1121 {
1122         int err;
1123         int tics;
1124
1125         printk(KERN_INFO "DSP module %s\n", mISDN_dsp_revision);
1126
1127         dsp_options = options;
1128         dsp_debug = debug;
1129
1130         /* set packet size */
1131         dsp_poll = poll;
1132         if (dsp_poll) {
1133                 if (dsp_poll > MAX_POLL) {
1134                         printk(KERN_ERR "%s: Wrong poll value (%d), use %d "
1135                                "maximum.\n", __func__, poll, MAX_POLL);
1136                         err = -EINVAL;
1137                         return err;
1138                 }
1139                 if (dsp_poll < 8) {
1140                         printk(KERN_ERR "%s: Wrong poll value (%d), use 8 "
1141                                "minimum.\n", __func__, dsp_poll);
1142                         err = -EINVAL;
1143                         return err;
1144                 }
1145                 dsp_tics = poll * HZ / 8000;
1146                 if (dsp_tics * 8000 != poll * HZ) {
1147                         printk(KERN_INFO "mISDN_dsp: Cannot clock every %d "
1148                                "samples (0,125 ms). It is not a multiple of "
1149                                "%d HZ.\n", poll, HZ);
1150                         err = -EINVAL;
1151                         return err;
1152                 }
1153         } else {
1154                 poll = 8;
1155                 while (poll <= MAX_POLL) {
1156                         tics = (poll * HZ) / 8000;
1157                         if (tics * 8000 == poll * HZ) {
1158                                 dsp_tics = tics;
1159                                 dsp_poll = poll;
1160                                 if (poll >= 64)
1161                                         break;
1162                         }
1163                         poll++;
1164                 }
1165         }
1166         if (dsp_poll == 0) {
1167                 printk(KERN_INFO "mISDN_dsp: There is no multiple of kernel "
1168                        "clock that equals exactly the duration of 8-256 "
1169                        "samples. (Choose kernel clock speed like 100, 250, "
1170                        "300, 1000)\n");
1171                 err = -EINVAL;
1172                 return err;
1173         }
1174         printk(KERN_INFO "mISDN_dsp: DSP clocks every %d samples. This equals "
1175                "%d jiffies.\n", dsp_poll, dsp_tics);
1176
1177         spin_lock_init(&dsp_lock);
1178         INIT_LIST_HEAD(&dsp_ilist);
1179         INIT_LIST_HEAD(&conf_ilist);
1180
1181         /* init conversion tables */
1182         dsp_audio_generate_law_tables();
1183         dsp_silence = (dsp_options & DSP_OPT_ULAW) ? 0xff : 0x2a;
1184         dsp_audio_law_to_s32 = (dsp_options & DSP_OPT_ULAW) ?
1185                 dsp_audio_ulaw_to_s32 : dsp_audio_alaw_to_s32;
1186         dsp_audio_generate_s2law_table();
1187         dsp_audio_generate_seven();
1188         dsp_audio_generate_mix_table();
1189         if (dsp_options & DSP_OPT_ULAW)
1190                 dsp_audio_generate_ulaw_samples();
1191         dsp_audio_generate_volume_changes();
1192
1193         err = dsp_pipeline_module_init();
1194         if (err) {
1195                 printk(KERN_ERR "mISDN_dsp: Can't initialize pipeline, "
1196                        "error(%d)\n", err);
1197                 return err;
1198         }
1199
1200         err = mISDN_register_Bprotocol(&DSP);
1201         if (err) {
1202                 printk(KERN_ERR "Can't register %s error(%d)\n", DSP.name, err);
1203                 return err;
1204         }
1205
1206         /* set sample timer */
1207         dsp_spl_tl.function = (void *)dsp_cmx_send;
1208         dsp_spl_tl.data = 0;
1209         init_timer(&dsp_spl_tl);
1210         dsp_spl_tl.expires = jiffies + dsp_tics;
1211         dsp_spl_jiffies = dsp_spl_tl.expires;
1212         add_timer(&dsp_spl_tl);
1213
1214         return 0;
1215 }
1216
1217
1218 static void __exit dsp_cleanup(void)
1219 {
1220         mISDN_unregister_Bprotocol(&DSP);
1221
1222         del_timer_sync(&dsp_spl_tl);
1223
1224         if (!list_empty(&dsp_ilist)) {
1225                 printk(KERN_ERR "mISDN_dsp: Audio DSP object inst list not "
1226                        "empty.\n");
1227         }
1228         if (!list_empty(&conf_ilist)) {
1229                 printk(KERN_ERR "mISDN_dsp: Conference list not empty. Not "
1230                        "all memory freed.\n");
1231         }
1232
1233         dsp_pipeline_module_exit();
1234 }
1235
1236 module_init(dsp_init);
1237 module_exit(dsp_cleanup);