linux/sound/drivers/aloop.c
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   1/*
   2 *  Loopback soundcard
   3 *
   4 *  Original code:
   5 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   6 *
   7 *  More accurate positioning and full-duplex support:
   8 *  Copyright (c) Ahmet İnan <ainan at mathematik.uni-freiburg.de>
   9 *
  10 *  Major (almost complete) rewrite:
  11 *  Copyright (c) by Takashi Iwai <tiwai@suse.de>
  12 *
  13 *  A next major update in 2010 (separate timers for playback and capture):
  14 *  Copyright (c) Jaroslav Kysela <perex@perex.cz>
  15 *
  16 *   This program is free software; you can redistribute it and/or modify
  17 *   it under the terms of the GNU General Public License as published by
  18 *   the Free Software Foundation; either version 2 of the License, or
  19 *   (at your option) any later version.
  20 *
  21 *   This program is distributed in the hope that it will be useful,
  22 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  23 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24 *   GNU General Public License for more details.
  25 *
  26 *   You should have received a copy of the GNU General Public License
  27 *   along with this program; if not, write to the Free Software
  28 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  29 *
  30 */
  31
  32#include <linux/init.h>
  33#include <linux/jiffies.h>
  34#include <linux/slab.h>
  35#include <linux/time.h>
  36#include <linux/wait.h>
  37#include <linux/module.h>
  38#include <linux/platform_device.h>
  39#include <sound/core.h>
  40#include <sound/control.h>
  41#include <sound/pcm.h>
  42#include <sound/info.h>
  43#include <sound/initval.h>
  44
  45MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>");
  46MODULE_DESCRIPTION("A loopback soundcard");
  47MODULE_LICENSE("GPL");
  48MODULE_SUPPORTED_DEVICE("{{ALSA,Loopback soundcard}}");
  49
  50#define MAX_PCM_SUBSTREAMS      8
  51
  52static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;      /* Index 0-MAX */
  53static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;       /* ID for this card */
  54static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0};
  55static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8};
  56static int pcm_notify[SNDRV_CARDS];
  57
  58module_param_array(index, int, NULL, 0444);
  59MODULE_PARM_DESC(index, "Index value for loopback soundcard.");
  60module_param_array(id, charp, NULL, 0444);
  61MODULE_PARM_DESC(id, "ID string for loopback soundcard.");
  62module_param_array(enable, bool, NULL, 0444);
  63MODULE_PARM_DESC(enable, "Enable this loopback soundcard.");
  64module_param_array(pcm_substreams, int, NULL, 0444);
  65MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver.");
  66module_param_array(pcm_notify, int, NULL, 0444);
  67MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes.");
  68
  69#define NO_PITCH 100000
  70
  71struct loopback_pcm;
  72
  73struct loopback_cable {
  74        spinlock_t lock;
  75        struct loopback_pcm *streams[2];
  76        struct snd_pcm_hardware hw;
  77        /* flags */
  78        unsigned int valid;
  79        unsigned int running;
  80        unsigned int pause;
  81};
  82
  83struct loopback_setup {
  84        unsigned int notify: 1;
  85        unsigned int rate_shift;
  86        unsigned int format;
  87        unsigned int rate;
  88        unsigned int channels;
  89        struct snd_ctl_elem_id active_id;
  90        struct snd_ctl_elem_id format_id;
  91        struct snd_ctl_elem_id rate_id;
  92        struct snd_ctl_elem_id channels_id;
  93};
  94
  95struct loopback {
  96        struct snd_card *card;
  97        struct mutex cable_lock;
  98        struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2];
  99        struct snd_pcm *pcm[2];
 100        struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2];
 101};
 102
 103struct loopback_pcm {
 104        struct loopback *loopback;
 105        struct snd_pcm_substream *substream;
 106        struct loopback_cable *cable;
 107        unsigned int pcm_buffer_size;
 108        unsigned int buf_pos;   /* position in buffer */
 109        unsigned int silent_size;
 110        /* PCM parameters */
 111        unsigned int pcm_period_size;
 112        unsigned int pcm_bps;           /* bytes per second */
 113        unsigned int pcm_salign;        /* bytes per sample * channels */
 114        unsigned int pcm_rate_shift;    /* rate shift value */
 115        /* flags */
 116        unsigned int period_update_pending :1;
 117        /* timer stuff */
 118        unsigned int irq_pos;           /* fractional IRQ position */
 119        unsigned int period_size_frac;
 120        unsigned int last_drift;
 121        unsigned long last_jiffies;
 122        struct timer_list timer;
 123        spinlock_t timer_lock;
 124};
 125
 126static struct platform_device *devices[SNDRV_CARDS];
 127
 128static inline unsigned int byte_pos(struct loopback_pcm *dpcm, unsigned int x)
 129{
 130        if (dpcm->pcm_rate_shift == NO_PITCH) {
 131                x /= HZ;
 132        } else {
 133                x = div_u64(NO_PITCH * (unsigned long long)x,
 134                            HZ * (unsigned long long)dpcm->pcm_rate_shift);
 135        }
 136        return x - (x % dpcm->pcm_salign);
 137}
 138
 139static inline unsigned int frac_pos(struct loopback_pcm *dpcm, unsigned int x)
 140{
 141        if (dpcm->pcm_rate_shift == NO_PITCH) { /* no pitch */
 142                return x * HZ;
 143        } else {
 144                x = div_u64(dpcm->pcm_rate_shift * (unsigned long long)x * HZ,
 145                            NO_PITCH);
 146        }
 147        return x;
 148}
 149
 150static inline struct loopback_setup *get_setup(struct loopback_pcm *dpcm)
 151{
 152        int device = dpcm->substream->pstr->pcm->device;
 153        
 154        if (dpcm->substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 155                device ^= 1;
 156        return &dpcm->loopback->setup[dpcm->substream->number][device];
 157}
 158
 159static inline unsigned int get_notify(struct loopback_pcm *dpcm)
 160{
 161        return get_setup(dpcm)->notify;
 162}
 163
 164static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
 165{
 166        return get_setup(dpcm)->rate_shift;
 167}
 168
 169static void loopback_timer_start(struct loopback_pcm *dpcm)
 170{
 171        unsigned long tick;
 172        unsigned int rate_shift = get_rate_shift(dpcm);
 173
 174        spin_lock(&dpcm->timer_lock);
 175        if (rate_shift != dpcm->pcm_rate_shift) {
 176                dpcm->pcm_rate_shift = rate_shift;
 177                dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
 178        }
 179        if (dpcm->period_size_frac <= dpcm->irq_pos) {
 180                dpcm->irq_pos %= dpcm->period_size_frac;
 181                dpcm->period_update_pending = 1;
 182        }
 183        tick = dpcm->period_size_frac - dpcm->irq_pos;
 184        tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
 185        dpcm->timer.expires = jiffies + tick;
 186        add_timer(&dpcm->timer);
 187        spin_unlock(&dpcm->timer_lock);
 188}
 189
 190static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
 191{
 192        spin_lock(&dpcm->timer_lock);
 193        del_timer(&dpcm->timer);
 194        dpcm->timer.expires = 0;
 195        spin_unlock(&dpcm->timer_lock);
 196}
 197
 198#define CABLE_VALID_PLAYBACK    (1 << SNDRV_PCM_STREAM_PLAYBACK)
 199#define CABLE_VALID_CAPTURE     (1 << SNDRV_PCM_STREAM_CAPTURE)
 200#define CABLE_VALID_BOTH        (CABLE_VALID_PLAYBACK|CABLE_VALID_CAPTURE)
 201
 202static int loopback_check_format(struct loopback_cable *cable, int stream)
 203{
 204        struct snd_pcm_runtime *runtime, *cruntime;
 205        struct loopback_setup *setup;
 206        struct snd_card *card;
 207        int check;
 208
 209        if (cable->valid != CABLE_VALID_BOTH) {
 210                if (stream == SNDRV_PCM_STREAM_PLAYBACK)
 211                        goto __notify;
 212                return 0;
 213        }
 214        runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 215                                                        substream->runtime;
 216        cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 217                                                        substream->runtime;
 218        check = runtime->format != cruntime->format ||
 219                runtime->rate != cruntime->rate ||
 220                runtime->channels != cruntime->channels;
 221        if (!check)
 222                return 0;
 223        if (stream == SNDRV_PCM_STREAM_CAPTURE) {
 224                return -EIO;
 225        } else {
 226                snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]->
 227                                        substream, SNDRV_PCM_STATE_DRAINING);
 228              __notify:
 229                runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->
 230                                                        substream->runtime;
 231                setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]);
 232                card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card;
 233                if (setup->format != runtime->format) {
 234                        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 235                                                        &setup->format_id);
 236                        setup->format = runtime->format;
 237                }
 238                if (setup->rate != runtime->rate) {
 239                        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 240                                                        &setup->rate_id);
 241                        setup->rate = runtime->rate;
 242                }
 243                if (setup->channels != runtime->channels) {
 244                        snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE,
 245                                                        &setup->channels_id);
 246                        setup->channels = runtime->channels;
 247                }
 248        }
 249        return 0;
 250}
 251
 252static void loopback_active_notify(struct loopback_pcm *dpcm)
 253{
 254        snd_ctl_notify(dpcm->loopback->card,
 255                       SNDRV_CTL_EVENT_MASK_VALUE,
 256                       &get_setup(dpcm)->active_id);
 257}
 258
 259static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
 260{
 261        struct snd_pcm_runtime *runtime = substream->runtime;
 262        struct loopback_pcm *dpcm = runtime->private_data;
 263        struct loopback_cable *cable = dpcm->cable;
 264        int err, stream = 1 << substream->stream;
 265
 266        switch (cmd) {
 267        case SNDRV_PCM_TRIGGER_START:
 268                err = loopback_check_format(cable, substream->stream);
 269                if (err < 0)
 270                        return err;
 271                dpcm->last_jiffies = jiffies;
 272                dpcm->pcm_rate_shift = 0;
 273                dpcm->last_drift = 0;
 274                spin_lock(&cable->lock);        
 275                cable->running |= stream;
 276                cable->pause &= ~stream;
 277                spin_unlock(&cable->lock);
 278                loopback_timer_start(dpcm);
 279                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 280                        loopback_active_notify(dpcm);
 281                break;
 282        case SNDRV_PCM_TRIGGER_STOP:
 283                spin_lock(&cable->lock);        
 284                cable->running &= ~stream;
 285                cable->pause &= ~stream;
 286                spin_unlock(&cable->lock);
 287                loopback_timer_stop(dpcm);
 288                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 289                        loopback_active_notify(dpcm);
 290                break;
 291        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 292                spin_lock(&cable->lock);        
 293                cable->pause |= stream;
 294                spin_unlock(&cable->lock);
 295                loopback_timer_stop(dpcm);
 296                break;
 297        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 298                spin_lock(&cable->lock);
 299                dpcm->last_jiffies = jiffies;
 300                cable->pause &= ~stream;
 301                spin_unlock(&cable->lock);
 302                loopback_timer_start(dpcm);
 303                break;
 304        default:
 305                return -EINVAL;
 306        }
 307        return 0;
 308}
 309
 310static void params_change_substream(struct loopback_pcm *dpcm,
 311                                    struct snd_pcm_runtime *runtime)
 312{
 313        struct snd_pcm_runtime *dst_runtime;
 314
 315        if (dpcm == NULL || dpcm->substream == NULL)
 316                return;
 317        dst_runtime = dpcm->substream->runtime;
 318        if (dst_runtime == NULL)
 319                return;
 320        dst_runtime->hw = dpcm->cable->hw;
 321}
 322
 323static void params_change(struct snd_pcm_substream *substream)
 324{
 325        struct snd_pcm_runtime *runtime = substream->runtime;
 326        struct loopback_pcm *dpcm = runtime->private_data;
 327        struct loopback_cable *cable = dpcm->cable;
 328
 329        cable->hw.formats = (1ULL << runtime->format);
 330        cable->hw.rate_min = runtime->rate;
 331        cable->hw.rate_max = runtime->rate;
 332        cable->hw.channels_min = runtime->channels;
 333        cable->hw.channels_max = runtime->channels;
 334        params_change_substream(cable->streams[SNDRV_PCM_STREAM_PLAYBACK],
 335                                runtime);
 336        params_change_substream(cable->streams[SNDRV_PCM_STREAM_CAPTURE],
 337                                runtime);
 338}
 339
 340static int loopback_prepare(struct snd_pcm_substream *substream)
 341{
 342        struct snd_pcm_runtime *runtime = substream->runtime;
 343        struct loopback_pcm *dpcm = runtime->private_data;
 344        struct loopback_cable *cable = dpcm->cable;
 345        int bps, salign;
 346
 347        salign = (snd_pcm_format_width(runtime->format) *
 348                                                runtime->channels) / 8;
 349        bps = salign * runtime->rate;
 350        if (bps <= 0 || salign <= 0)
 351                return -EINVAL;
 352
 353        dpcm->buf_pos = 0;
 354        dpcm->pcm_buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
 355        if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
 356                /* clear capture buffer */
 357                dpcm->silent_size = dpcm->pcm_buffer_size;
 358                snd_pcm_format_set_silence(runtime->format, runtime->dma_area,
 359                                           runtime->buffer_size * runtime->channels);
 360        }
 361
 362        dpcm->irq_pos = 0;
 363        dpcm->period_update_pending = 0;
 364        dpcm->pcm_bps = bps;
 365        dpcm->pcm_salign = salign;
 366        dpcm->pcm_period_size = frames_to_bytes(runtime, runtime->period_size);
 367
 368        mutex_lock(&dpcm->loopback->cable_lock);
 369        if (!(cable->valid & ~(1 << substream->stream)) ||
 370            (get_setup(dpcm)->notify &&
 371             substream->stream == SNDRV_PCM_STREAM_PLAYBACK))
 372                params_change(substream);
 373        cable->valid |= 1 << substream->stream;
 374        mutex_unlock(&dpcm->loopback->cable_lock);
 375
 376        return 0;
 377}
 378
 379static void clear_capture_buf(struct loopback_pcm *dpcm, unsigned int bytes)
 380{
 381        struct snd_pcm_runtime *runtime = dpcm->substream->runtime;
 382        char *dst = runtime->dma_area;
 383        unsigned int dst_off = dpcm->buf_pos;
 384
 385        if (dpcm->silent_size >= dpcm->pcm_buffer_size)
 386                return;
 387        if (dpcm->silent_size + bytes > dpcm->pcm_buffer_size)
 388                bytes = dpcm->pcm_buffer_size - dpcm->silent_size;
 389
 390        for (;;) {
 391                unsigned int size = bytes;
 392                if (dst_off + size > dpcm->pcm_buffer_size)
 393                        size = dpcm->pcm_buffer_size - dst_off;
 394                snd_pcm_format_set_silence(runtime->format, dst + dst_off,
 395                                           bytes_to_frames(runtime, size) *
 396                                                runtime->channels);
 397                dpcm->silent_size += size;
 398                bytes -= size;
 399                if (!bytes)
 400                        break;
 401                dst_off = 0;
 402        }
 403}
 404
 405static void copy_play_buf(struct loopback_pcm *play,
 406                          struct loopback_pcm *capt,
 407                          unsigned int bytes)
 408{
 409        struct snd_pcm_runtime *runtime = play->substream->runtime;
 410        char *src = runtime->dma_area;
 411        char *dst = capt->substream->runtime->dma_area;
 412        unsigned int src_off = play->buf_pos;
 413        unsigned int dst_off = capt->buf_pos;
 414        unsigned int clear_bytes = 0;
 415
 416        /* check if playback is draining, trim the capture copy size
 417         * when our pointer is at the end of playback ring buffer */
 418        if (runtime->status->state == SNDRV_PCM_STATE_DRAINING &&
 419            snd_pcm_playback_hw_avail(runtime) < runtime->buffer_size) { 
 420                snd_pcm_uframes_t appl_ptr, appl_ptr1, diff;
 421                appl_ptr = appl_ptr1 = runtime->control->appl_ptr;
 422                appl_ptr1 -= appl_ptr1 % runtime->buffer_size;
 423                appl_ptr1 += play->buf_pos / play->pcm_salign;
 424                if (appl_ptr < appl_ptr1)
 425                        appl_ptr1 -= runtime->buffer_size;
 426                diff = (appl_ptr - appl_ptr1) * play->pcm_salign;
 427                if (diff < bytes) {
 428                        clear_bytes = bytes - diff;
 429                        bytes = diff;
 430                }
 431        }
 432
 433        for (;;) {
 434                unsigned int size = bytes;
 435                if (src_off + size > play->pcm_buffer_size)
 436                        size = play->pcm_buffer_size - src_off;
 437                if (dst_off + size > capt->pcm_buffer_size)
 438                        size = capt->pcm_buffer_size - dst_off;
 439                memcpy(dst + dst_off, src + src_off, size);
 440                capt->silent_size = 0;
 441                bytes -= size;
 442                if (!bytes)
 443                        break;
 444                src_off = (src_off + size) % play->pcm_buffer_size;
 445                dst_off = (dst_off + size) % capt->pcm_buffer_size;
 446        }
 447
 448        if (clear_bytes > 0) {
 449                clear_capture_buf(capt, clear_bytes);
 450                capt->silent_size = 0;
 451        }
 452}
 453
 454static inline unsigned int bytepos_delta(struct loopback_pcm *dpcm,
 455                                         unsigned int jiffies_delta)
 456{
 457        unsigned long last_pos;
 458        unsigned int delta;
 459
 460        last_pos = byte_pos(dpcm, dpcm->irq_pos);
 461        dpcm->irq_pos += jiffies_delta * dpcm->pcm_bps;
 462        delta = byte_pos(dpcm, dpcm->irq_pos) - last_pos;
 463        if (delta >= dpcm->last_drift)
 464                delta -= dpcm->last_drift;
 465        dpcm->last_drift = 0;
 466        if (dpcm->irq_pos >= dpcm->period_size_frac) {
 467                dpcm->irq_pos %= dpcm->period_size_frac;
 468                dpcm->period_update_pending = 1;
 469        }
 470        return delta;
 471}
 472
 473static inline void bytepos_finish(struct loopback_pcm *dpcm,
 474                                  unsigned int delta)
 475{
 476        dpcm->buf_pos += delta;
 477        dpcm->buf_pos %= dpcm->pcm_buffer_size;
 478}
 479
 480static unsigned int loopback_pos_update(struct loopback_cable *cable)
 481{
 482        struct loopback_pcm *dpcm_play =
 483                        cable->streams[SNDRV_PCM_STREAM_PLAYBACK];
 484        struct loopback_pcm *dpcm_capt =
 485                        cable->streams[SNDRV_PCM_STREAM_CAPTURE];
 486        unsigned long delta_play = 0, delta_capt = 0;
 487        unsigned int running, count1, count2;
 488        unsigned long flags;
 489
 490        spin_lock_irqsave(&cable->lock, flags);
 491        running = cable->running ^ cable->pause;
 492        if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
 493                delta_play = jiffies - dpcm_play->last_jiffies;
 494                dpcm_play->last_jiffies += delta_play;
 495        }
 496
 497        if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) {
 498                delta_capt = jiffies - dpcm_capt->last_jiffies;
 499                dpcm_capt->last_jiffies += delta_capt;
 500        }
 501
 502        if (delta_play == 0 && delta_capt == 0)
 503                goto unlock;
 504                
 505        if (delta_play > delta_capt) {
 506                count1 = bytepos_delta(dpcm_play, delta_play - delta_capt);
 507                bytepos_finish(dpcm_play, count1);
 508                delta_play = delta_capt;
 509        } else if (delta_play < delta_capt) {
 510                count1 = bytepos_delta(dpcm_capt, delta_capt - delta_play);
 511                clear_capture_buf(dpcm_capt, count1);
 512                bytepos_finish(dpcm_capt, count1);
 513                delta_capt = delta_play;
 514        }
 515
 516        if (delta_play == 0 && delta_capt == 0)
 517                goto unlock;
 518
 519        /* note delta_capt == delta_play at this moment */
 520        count1 = bytepos_delta(dpcm_play, delta_play);
 521        count2 = bytepos_delta(dpcm_capt, delta_capt);
 522        if (count1 < count2) {
 523                dpcm_capt->last_drift = count2 - count1;
 524                count1 = count2;
 525        } else if (count1 > count2) {
 526                dpcm_play->last_drift = count1 - count2;
 527        }
 528        copy_play_buf(dpcm_play, dpcm_capt, count1);
 529        bytepos_finish(dpcm_play, count1);
 530        bytepos_finish(dpcm_capt, count1);
 531 unlock:
 532        spin_unlock_irqrestore(&cable->lock, flags);
 533        return running;
 534}
 535
 536static void loopback_timer_function(unsigned long data)
 537{
 538        struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
 539        unsigned int running;
 540
 541        running = loopback_pos_update(dpcm->cable);
 542        if (running & (1 << dpcm->substream->stream)) {
 543                loopback_timer_start(dpcm);
 544                if (dpcm->period_update_pending) {
 545                        dpcm->period_update_pending = 0;
 546                        snd_pcm_period_elapsed(dpcm->substream);
 547                }
 548        }
 549}
 550
 551static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 552{
 553        struct snd_pcm_runtime *runtime = substream->runtime;
 554        struct loopback_pcm *dpcm = runtime->private_data;
 555
 556        loopback_pos_update(dpcm->cable);
 557        return bytes_to_frames(runtime, dpcm->buf_pos);
 558}
 559
 560static struct snd_pcm_hardware loopback_pcm_hardware =
 561{
 562        .info =         (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_MMAP |
 563                         SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_PAUSE),
 564        .formats =      (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S16_BE |
 565                         SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S32_BE |
 566                         SNDRV_PCM_FMTBIT_FLOAT_LE | SNDRV_PCM_FMTBIT_FLOAT_BE),
 567        .rates =        SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_192000,
 568        .rate_min =             8000,
 569        .rate_max =             192000,
 570        .channels_min =         1,
 571        .channels_max =         32,
 572        .buffer_bytes_max =     2 * 1024 * 1024,
 573        .period_bytes_min =     64,
 574        /* note check overflow in frac_pos() using pcm_rate_shift before
 575           changing period_bytes_max value */
 576        .period_bytes_max =     1024 * 1024,
 577        .periods_min =          1,
 578        .periods_max =          1024,
 579        .fifo_size =            0,
 580};
 581
 582static void loopback_runtime_free(struct snd_pcm_runtime *runtime)
 583{
 584        struct loopback_pcm *dpcm = runtime->private_data;
 585        kfree(dpcm);
 586}
 587
 588static int loopback_hw_params(struct snd_pcm_substream *substream,
 589                              struct snd_pcm_hw_params *params)
 590{
 591        return snd_pcm_lib_alloc_vmalloc_buffer(substream,
 592                                                params_buffer_bytes(params));
 593}
 594
 595static int loopback_hw_free(struct snd_pcm_substream *substream)
 596{
 597        struct snd_pcm_runtime *runtime = substream->runtime;
 598        struct loopback_pcm *dpcm = runtime->private_data;
 599        struct loopback_cable *cable = dpcm->cable;
 600
 601        mutex_lock(&dpcm->loopback->cable_lock);
 602        cable->valid &= ~(1 << substream->stream);
 603        mutex_unlock(&dpcm->loopback->cable_lock);
 604        return snd_pcm_lib_free_vmalloc_buffer(substream);
 605}
 606
 607static unsigned int get_cable_index(struct snd_pcm_substream *substream)
 608{
 609        if (!substream->pcm->device)
 610                return substream->stream;
 611        else
 612                return !substream->stream;
 613}
 614
 615static int rule_format(struct snd_pcm_hw_params *params,
 616                       struct snd_pcm_hw_rule *rule)
 617{
 618
 619        struct snd_pcm_hardware *hw = rule->private;
 620        struct snd_mask *maskp = hw_param_mask(params, rule->var);
 621
 622        maskp->bits[0] &= (u_int32_t)hw->formats;
 623        maskp->bits[1] &= (u_int32_t)(hw->formats >> 32);
 624        memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
 625        if (! maskp->bits[0] && ! maskp->bits[1])
 626                return -EINVAL;
 627        return 0;
 628}
 629
 630static int rule_rate(struct snd_pcm_hw_params *params,
 631                     struct snd_pcm_hw_rule *rule)
 632{
 633        struct snd_pcm_hardware *hw = rule->private;
 634        struct snd_interval t;
 635
 636        t.min = hw->rate_min;
 637        t.max = hw->rate_max;
 638        t.openmin = t.openmax = 0;
 639        t.integer = 0;
 640        return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 641}
 642
 643static int rule_channels(struct snd_pcm_hw_params *params,
 644                         struct snd_pcm_hw_rule *rule)
 645{
 646        struct snd_pcm_hardware *hw = rule->private;
 647        struct snd_interval t;
 648
 649        t.min = hw->channels_min;
 650        t.max = hw->channels_max;
 651        t.openmin = t.openmax = 0;
 652        t.integer = 0;
 653        return snd_interval_refine(hw_param_interval(params, rule->var), &t);
 654}
 655
 656static int loopback_open(struct snd_pcm_substream *substream)
 657{
 658        struct snd_pcm_runtime *runtime = substream->runtime;
 659        struct loopback *loopback = substream->private_data;
 660        struct loopback_pcm *dpcm;
 661        struct loopback_cable *cable;
 662        int err = 0;
 663        int dev = get_cable_index(substream);
 664
 665        mutex_lock(&loopback->cable_lock);
 666        dpcm = kzalloc(sizeof(*dpcm), GFP_KERNEL);
 667        if (!dpcm) {
 668                err = -ENOMEM;
 669                goto unlock;
 670        }
 671        dpcm->loopback = loopback;
 672        dpcm->substream = substream;
 673        setup_timer(&dpcm->timer, loopback_timer_function,
 674                    (unsigned long)dpcm);
 675        spin_lock_init(&dpcm->timer_lock);
 676
 677        cable = loopback->cables[substream->number][dev];
 678        if (!cable) {
 679                cable = kzalloc(sizeof(*cable), GFP_KERNEL);
 680                if (!cable) {
 681                        kfree(dpcm);
 682                        err = -ENOMEM;
 683                        goto unlock;
 684                }
 685                spin_lock_init(&cable->lock);
 686                cable->hw = loopback_pcm_hardware;
 687                loopback->cables[substream->number][dev] = cable;
 688        }
 689        dpcm->cable = cable;
 690        cable->streams[substream->stream] = dpcm;
 691
 692        snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 693
 694        /* use dynamic rules based on actual runtime->hw values */
 695        /* note that the default rules created in the PCM midlevel code */
 696        /* are cached -> they do not reflect the actual state */
 697        err = snd_pcm_hw_rule_add(runtime, 0,
 698                                  SNDRV_PCM_HW_PARAM_FORMAT,
 699                                  rule_format, &runtime->hw,
 700                                  SNDRV_PCM_HW_PARAM_FORMAT, -1);
 701        if (err < 0)
 702                goto unlock;
 703        err = snd_pcm_hw_rule_add(runtime, 0,
 704                                  SNDRV_PCM_HW_PARAM_RATE,
 705                                  rule_rate, &runtime->hw,
 706                                  SNDRV_PCM_HW_PARAM_RATE, -1);
 707        if (err < 0)
 708                goto unlock;
 709        err = snd_pcm_hw_rule_add(runtime, 0,
 710                                  SNDRV_PCM_HW_PARAM_CHANNELS,
 711                                  rule_channels, &runtime->hw,
 712                                  SNDRV_PCM_HW_PARAM_CHANNELS, -1);
 713        if (err < 0)
 714                goto unlock;
 715
 716        runtime->private_data = dpcm;
 717        runtime->private_free = loopback_runtime_free;
 718        if (get_notify(dpcm))
 719                runtime->hw = loopback_pcm_hardware;
 720        else
 721                runtime->hw = cable->hw;
 722 unlock:
 723        mutex_unlock(&loopback->cable_lock);
 724        return err;
 725}
 726
 727static int loopback_close(struct snd_pcm_substream *substream)
 728{
 729        struct loopback *loopback = substream->private_data;
 730        struct loopback_pcm *dpcm = substream->runtime->private_data;
 731        struct loopback_cable *cable;
 732        int dev = get_cable_index(substream);
 733
 734        loopback_timer_stop(dpcm);
 735        mutex_lock(&loopback->cable_lock);
 736        cable = loopback->cables[substream->number][dev];
 737        if (cable->streams[!substream->stream]) {
 738                /* other stream is still alive */
 739                cable->streams[substream->stream] = NULL;
 740        } else {
 741                /* free the cable */
 742                loopback->cables[substream->number][dev] = NULL;
 743                kfree(cable);
 744        }
 745        mutex_unlock(&loopback->cable_lock);
 746        return 0;
 747}
 748
 749static struct snd_pcm_ops loopback_playback_ops = {
 750        .open =         loopback_open,
 751        .close =        loopback_close,
 752        .ioctl =        snd_pcm_lib_ioctl,
 753        .hw_params =    loopback_hw_params,
 754        .hw_free =      loopback_hw_free,
 755        .prepare =      loopback_prepare,
 756        .trigger =      loopback_trigger,
 757        .pointer =      loopback_pointer,
 758        .page =         snd_pcm_lib_get_vmalloc_page,
 759        .mmap =         snd_pcm_lib_mmap_vmalloc,
 760};
 761
 762static struct snd_pcm_ops loopback_capture_ops = {
 763        .open =         loopback_open,
 764        .close =        loopback_close,
 765        .ioctl =        snd_pcm_lib_ioctl,
 766        .hw_params =    loopback_hw_params,
 767        .hw_free =      loopback_hw_free,
 768        .prepare =      loopback_prepare,
 769        .trigger =      loopback_trigger,
 770        .pointer =      loopback_pointer,
 771        .page =         snd_pcm_lib_get_vmalloc_page,
 772        .mmap =         snd_pcm_lib_mmap_vmalloc,
 773};
 774
 775static int __devinit loopback_pcm_new(struct loopback *loopback,
 776                                      int device, int substreams)
 777{
 778        struct snd_pcm *pcm;
 779        int err;
 780
 781        err = snd_pcm_new(loopback->card, "Loopback PCM", device,
 782                          substreams, substreams, &pcm);
 783        if (err < 0)
 784                return err;
 785        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &loopback_playback_ops);
 786        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &loopback_capture_ops);
 787
 788        pcm->private_data = loopback;
 789        pcm->info_flags = 0;
 790        strcpy(pcm->name, "Loopback PCM");
 791
 792        loopback->pcm[device] = pcm;
 793        return 0;
 794}
 795
 796static int loopback_rate_shift_info(struct snd_kcontrol *kcontrol,   
 797                                    struct snd_ctl_elem_info *uinfo) 
 798{
 799        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 800        uinfo->count = 1;
 801        uinfo->value.integer.min = 80000;
 802        uinfo->value.integer.max = 120000;
 803        uinfo->value.integer.step = 1;
 804        return 0;
 805}                                  
 806
 807static int loopback_rate_shift_get(struct snd_kcontrol *kcontrol,
 808                                   struct snd_ctl_elem_value *ucontrol)
 809{
 810        struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 811        
 812        ucontrol->value.integer.value[0] =
 813                loopback->setup[kcontrol->id.subdevice]
 814                               [kcontrol->id.device].rate_shift;
 815        return 0;
 816}
 817
 818static int loopback_rate_shift_put(struct snd_kcontrol *kcontrol,
 819                                   struct snd_ctl_elem_value *ucontrol)
 820{
 821        struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 822        unsigned int val;
 823        int change = 0;
 824
 825        val = ucontrol->value.integer.value[0];
 826        if (val < 80000)
 827                val = 80000;
 828        if (val > 120000)
 829                val = 120000;   
 830        mutex_lock(&loopback->cable_lock);
 831        if (val != loopback->setup[kcontrol->id.subdevice]
 832                                  [kcontrol->id.device].rate_shift) {
 833                loopback->setup[kcontrol->id.subdevice]
 834                               [kcontrol->id.device].rate_shift = val;
 835                change = 1;
 836        }
 837        mutex_unlock(&loopback->cable_lock);
 838        return change;
 839}
 840
 841static int loopback_notify_get(struct snd_kcontrol *kcontrol,
 842                               struct snd_ctl_elem_value *ucontrol)
 843{
 844        struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 845        
 846        ucontrol->value.integer.value[0] =
 847                loopback->setup[kcontrol->id.subdevice]
 848                               [kcontrol->id.device].notify;
 849        return 0;
 850}
 851
 852static int loopback_notify_put(struct snd_kcontrol *kcontrol,
 853                               struct snd_ctl_elem_value *ucontrol)
 854{
 855        struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 856        unsigned int val;
 857        int change = 0;
 858
 859        val = ucontrol->value.integer.value[0] ? 1 : 0;
 860        if (val != loopback->setup[kcontrol->id.subdevice]
 861                                [kcontrol->id.device].notify) {
 862                loopback->setup[kcontrol->id.subdevice]
 863                        [kcontrol->id.device].notify = val;
 864                change = 1;
 865        }
 866        return change;
 867}
 868
 869static int loopback_active_get(struct snd_kcontrol *kcontrol,
 870                               struct snd_ctl_elem_value *ucontrol)
 871{
 872        struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 873        struct loopback_cable *cable = loopback->cables
 874                        [kcontrol->id.subdevice][kcontrol->id.device ^ 1];
 875        unsigned int val = 0;
 876
 877        if (cable != NULL)
 878                val = (cable->running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ?
 879                                                                        1 : 0;
 880        ucontrol->value.integer.value[0] = val;
 881        return 0;
 882}
 883
 884static int loopback_format_info(struct snd_kcontrol *kcontrol,   
 885                                struct snd_ctl_elem_info *uinfo) 
 886{
 887        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 888        uinfo->count = 1;
 889        uinfo->value.integer.min = 0;
 890        uinfo->value.integer.max = SNDRV_PCM_FORMAT_LAST;
 891        uinfo->value.integer.step = 1;
 892        return 0;
 893}                                  
 894
 895static int loopback_format_get(struct snd_kcontrol *kcontrol,
 896                               struct snd_ctl_elem_value *ucontrol)
 897{
 898        struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 899        
 900        ucontrol->value.integer.value[0] =
 901                loopback->setup[kcontrol->id.subdevice]
 902                               [kcontrol->id.device].format;
 903        return 0;
 904}
 905
 906static int loopback_rate_info(struct snd_kcontrol *kcontrol,   
 907                              struct snd_ctl_elem_info *uinfo) 
 908{
 909        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 910        uinfo->count = 1;
 911        uinfo->value.integer.min = 0;
 912        uinfo->value.integer.max = 192000;
 913        uinfo->value.integer.step = 1;
 914        return 0;
 915}                                  
 916
 917static int loopback_rate_get(struct snd_kcontrol *kcontrol,
 918                             struct snd_ctl_elem_value *ucontrol)
 919{
 920        struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 921        
 922        ucontrol->value.integer.value[0] =
 923                loopback->setup[kcontrol->id.subdevice]
 924                               [kcontrol->id.device].rate;
 925        return 0;
 926}
 927
 928static int loopback_channels_info(struct snd_kcontrol *kcontrol,   
 929                                  struct snd_ctl_elem_info *uinfo) 
 930{
 931        uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 932        uinfo->count = 1;
 933        uinfo->value.integer.min = 1;
 934        uinfo->value.integer.max = 1024;
 935        uinfo->value.integer.step = 1;
 936        return 0;
 937}                                  
 938
 939static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 940                                 struct snd_ctl_elem_value *ucontrol)
 941{
 942        struct loopback *loopback = snd_kcontrol_chip(kcontrol);
 943        
 944        ucontrol->value.integer.value[0] =
 945                loopback->setup[kcontrol->id.subdevice]
 946                               [kcontrol->id.device].channels;
 947        return 0;
 948}
 949
 950static struct snd_kcontrol_new loopback_controls[]  __devinitdata = {
 951{
 952        .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 953        .name =         "PCM Rate Shift 100000",
 954        .info =         loopback_rate_shift_info,
 955        .get =          loopback_rate_shift_get,
 956        .put =          loopback_rate_shift_put,
 957},
 958{
 959        .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 960        .name =         "PCM Notify",
 961        .info =         snd_ctl_boolean_mono_info,
 962        .get =          loopback_notify_get,
 963        .put =          loopback_notify_put,
 964},
 965#define ACTIVE_IDX 2
 966{
 967        .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 968        .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 969        .name =         "PCM Slave Active",
 970        .info =         snd_ctl_boolean_mono_info,
 971        .get =          loopback_active_get,
 972},
 973#define FORMAT_IDX 3
 974{
 975        .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 976        .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 977        .name =         "PCM Slave Format",
 978        .info =         loopback_format_info,
 979        .get =          loopback_format_get
 980},
 981#define RATE_IDX 4
 982{
 983        .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 984        .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 985        .name =         "PCM Slave Rate",
 986        .info =         loopback_rate_info,
 987        .get =          loopback_rate_get
 988},
 989#define CHANNELS_IDX 5
 990{
 991        .access =       SNDRV_CTL_ELEM_ACCESS_READ,
 992        .iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 993        .name =         "PCM Slave Channels",
 994        .info =         loopback_channels_info,
 995        .get =          loopback_channels_get
 996}
 997};
 998
 999static int __devinit loopback_mixer_new(struct loopback *loopback, int notify)
1000{
1001        struct snd_card *card = loopback->card;
1002        struct snd_pcm *pcm;
1003        struct snd_kcontrol *kctl;
1004        struct loopback_setup *setup;
1005        int err, dev, substr, substr_count, idx;
1006
1007        strcpy(card->mixername, "Loopback Mixer");
1008        for (dev = 0; dev < 2; dev++) {
1009                pcm = loopback->pcm[dev];
1010                substr_count =
1011                    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream_count;
1012                for (substr = 0; substr < substr_count; substr++) {
1013                        setup = &loopback->setup[substr][dev];
1014                        setup->notify = notify;
1015                        setup->rate_shift = NO_PITCH;
1016                        setup->format = SNDRV_PCM_FORMAT_S16_LE;
1017                        setup->rate = 48000;
1018                        setup->channels = 2;
1019                        for (idx = 0; idx < ARRAY_SIZE(loopback_controls);
1020                                                                        idx++) {
1021                                kctl = snd_ctl_new1(&loopback_controls[idx],
1022                                                    loopback);
1023                                if (!kctl)
1024                                        return -ENOMEM;
1025                                kctl->id.device = dev;
1026                                kctl->id.subdevice = substr;
1027                                switch (idx) {
1028                                case ACTIVE_IDX:
1029                                        setup->active_id = kctl->id;
1030                                        break;
1031                                case FORMAT_IDX:
1032                                        setup->format_id = kctl->id;
1033                                        break;
1034                                case RATE_IDX:
1035                                        setup->rate_id = kctl->id;
1036                                        break;
1037                                case CHANNELS_IDX:
1038                                        setup->channels_id = kctl->id;
1039                                        break;
1040                                default:
1041                                        break;
1042                                }
1043                                err = snd_ctl_add(card, kctl);
1044                                if (err < 0)
1045                                        return err;
1046                        }
1047                }
1048        }
1049        return 0;
1050}
1051
1052#ifdef CONFIG_PROC_FS
1053
1054static void print_dpcm_info(struct snd_info_buffer *buffer,
1055                            struct loopback_pcm *dpcm,
1056                            const char *id)
1057{
1058        snd_iprintf(buffer, "  %s\n", id);
1059        if (dpcm == NULL) {
1060                snd_iprintf(buffer, "    inactive\n");
1061                return;
1062        }
1063        snd_iprintf(buffer, "    buffer_size:\t%u\n", dpcm->pcm_buffer_size);
1064        snd_iprintf(buffer, "    buffer_pos:\t\t%u\n", dpcm->buf_pos);
1065        snd_iprintf(buffer, "    silent_size:\t%u\n", dpcm->silent_size);
1066        snd_iprintf(buffer, "    period_size:\t%u\n", dpcm->pcm_period_size);
1067        snd_iprintf(buffer, "    bytes_per_sec:\t%u\n", dpcm->pcm_bps);
1068        snd_iprintf(buffer, "    sample_align:\t%u\n", dpcm->pcm_salign);
1069        snd_iprintf(buffer, "    rate_shift:\t\t%u\n", dpcm->pcm_rate_shift);
1070        snd_iprintf(buffer, "    update_pending:\t%u\n",
1071                                                dpcm->period_update_pending);
1072        snd_iprintf(buffer, "    irq_pos:\t\t%u\n", dpcm->irq_pos);
1073        snd_iprintf(buffer, "    period_frac:\t%u\n", dpcm->period_size_frac);
1074        snd_iprintf(buffer, "    last_jiffies:\t%lu (%lu)\n",
1075                                        dpcm->last_jiffies, jiffies);
1076        snd_iprintf(buffer, "    timer_expires:\t%lu\n", dpcm->timer.expires);
1077}
1078
1079static void print_substream_info(struct snd_info_buffer *buffer,
1080                                 struct loopback *loopback,
1081                                 int sub,
1082                                 int num)
1083{
1084        struct loopback_cable *cable = loopback->cables[sub][num];
1085
1086        snd_iprintf(buffer, "Cable %i substream %i:\n", num, sub);
1087        if (cable == NULL) {
1088                snd_iprintf(buffer, "  inactive\n");
1089                return;
1090        }
1091        snd_iprintf(buffer, "  valid: %u\n", cable->valid);
1092        snd_iprintf(buffer, "  running: %u\n", cable->running);
1093        snd_iprintf(buffer, "  pause: %u\n", cable->pause);
1094        print_dpcm_info(buffer, cable->streams[0], "Playback");
1095        print_dpcm_info(buffer, cable->streams[1], "Capture");
1096}
1097
1098static void print_cable_info(struct snd_info_entry *entry,
1099                             struct snd_info_buffer *buffer)
1100{
1101        struct loopback *loopback = entry->private_data;
1102        int sub, num;
1103
1104        mutex_lock(&loopback->cable_lock);
1105        num = entry->name[strlen(entry->name)-1];
1106        num = num == '0' ? 0 : 1;
1107        for (sub = 0; sub < MAX_PCM_SUBSTREAMS; sub++)
1108                print_substream_info(buffer, loopback, sub, num);
1109        mutex_unlock(&loopback->cable_lock);
1110}
1111
1112static int __devinit loopback_proc_new(struct loopback *loopback, int cidx)
1113{
1114        char name[32];
1115        struct snd_info_entry *entry;
1116        int err;
1117
1118        snprintf(name, sizeof(name), "cable#%d", cidx);
1119        err = snd_card_proc_new(loopback->card, name, &entry);
1120        if (err < 0)
1121                return err;
1122
1123        snd_info_set_text_ops(entry, loopback, print_cable_info);
1124        return 0;
1125}
1126
1127#else /* !CONFIG_PROC_FS */
1128
1129#define loopback_proc_new(loopback, cidx) do { } while (0)
1130
1131#endif
1132
1133static int __devinit loopback_probe(struct platform_device *devptr)
1134{
1135        struct snd_card *card;
1136        struct loopback *loopback;
1137        int dev = devptr->id;
1138        int err;
1139
1140        err = snd_card_create(index[dev], id[dev], THIS_MODULE,
1141                              sizeof(struct loopback), &card);
1142        if (err < 0)
1143                return err;
1144        loopback = card->private_data;
1145
1146        if (pcm_substreams[dev] < 1)
1147                pcm_substreams[dev] = 1;
1148        if (pcm_substreams[dev] > MAX_PCM_SUBSTREAMS)
1149                pcm_substreams[dev] = MAX_PCM_SUBSTREAMS;
1150        
1151        loopback->card = card;
1152        mutex_init(&loopback->cable_lock);
1153
1154        err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]);
1155        if (err < 0)
1156                goto __nodev;
1157        err = loopback_pcm_new(loopback, 1, pcm_substreams[dev]);
1158        if (err < 0)
1159                goto __nodev;
1160        err = loopback_mixer_new(loopback, pcm_notify[dev] ? 1 : 0);
1161        if (err < 0)
1162                goto __nodev;
1163        loopback_proc_new(loopback, 0);
1164        loopback_proc_new(loopback, 1);
1165        strcpy(card->driver, "Loopback");
1166        strcpy(card->shortname, "Loopback");
1167        sprintf(card->longname, "Loopback %i", dev + 1);
1168        err = snd_card_register(card);
1169        if (!err) {
1170                platform_set_drvdata(devptr, card);
1171                return 0;
1172        }
1173      __nodev:
1174        snd_card_free(card);
1175        return err;
1176}
1177
1178static int __devexit loopback_remove(struct platform_device *devptr)
1179{
1180        snd_card_free(platform_get_drvdata(devptr));
1181        platform_set_drvdata(devptr, NULL);
1182        return 0;
1183}
1184
1185#ifdef CONFIG_PM_SLEEP
1186static int loopback_suspend(struct device *pdev)
1187{
1188        struct snd_card *card = dev_get_drvdata(pdev);
1189        struct loopback *loopback = card->private_data;
1190
1191        snd_power_change_state(card, SNDRV_CTL_POWER_D3hot);
1192
1193        snd_pcm_suspend_all(loopback->pcm[0]);
1194        snd_pcm_suspend_all(loopback->pcm[1]);
1195        return 0;
1196}
1197        
1198static int loopback_resume(struct device *pdev)
1199{
1200        struct snd_card *card = dev_get_drvdata(pdev);
1201
1202        snd_power_change_state(card, SNDRV_CTL_POWER_D0);
1203        return 0;
1204}
1205
1206static SIMPLE_DEV_PM_OPS(loopback_pm, loopback_suspend, loopback_resume);
1207#define LOOPBACK_PM_OPS &loopback_pm
1208#else
1209#define LOOPBACK_PM_OPS NULL
1210#endif
1211
1212#define SND_LOOPBACK_DRIVER     "snd_aloop"
1213
1214static struct platform_driver loopback_driver = {
1215        .probe          = loopback_probe,
1216        .remove         = __devexit_p(loopback_remove),
1217        .driver         = {
1218                .name   = SND_LOOPBACK_DRIVER,
1219                .owner  = THIS_MODULE,
1220                .pm     = LOOPBACK_PM_OPS,
1221        },
1222};
1223
1224static void loopback_unregister_all(void)
1225{
1226        int i;
1227
1228        for (i = 0; i < ARRAY_SIZE(devices); ++i)
1229                platform_device_unregister(devices[i]);
1230        platform_driver_unregister(&loopback_driver);
1231}
1232
1233static int __init alsa_card_loopback_init(void)
1234{
1235        int i, err, cards;
1236
1237        err = platform_driver_register(&loopback_driver);
1238        if (err < 0)
1239                return err;
1240
1241
1242        cards = 0;
1243        for (i = 0; i < SNDRV_CARDS; i++) {
1244                struct platform_device *device;
1245                if (!enable[i])
1246                        continue;
1247                device = platform_device_register_simple(SND_LOOPBACK_DRIVER,
1248                                                         i, NULL, 0);
1249                if (IS_ERR(device))
1250                        continue;
1251                if (!platform_get_drvdata(device)) {
1252                        platform_device_unregister(device);
1253                        continue;
1254                }
1255                devices[i] = device;
1256                cards++;
1257        }
1258        if (!cards) {
1259#ifdef MODULE
1260                printk(KERN_ERR "aloop: No loopback enabled\n");
1261#endif
1262                loopback_unregister_all();
1263                return -ENODEV;
1264        }
1265        return 0;
1266}
1267
1268static void __exit alsa_card_loopback_exit(void)
1269{
1270        loopback_unregister_all();
1271}
1272
1273module_init(alsa_card_loopback_init)
1274module_exit(alsa_card_loopback_exit)
1275
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