linux/sound/isa/sb/emu8000_pcm.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * pcm emulation on emu8000 wavetable
   4 *
   5 *  Copyright (C) 2002 Takashi Iwai <tiwai@suse.de>
   6 */
   7
   8#include "emu8000_local.h"
   9
  10#include <linux/sched/signal.h>
  11#include <linux/init.h>
  12#include <linux/slab.h>
  13#include <sound/initval.h>
  14#include <sound/pcm.h>
  15
  16/*
  17 * define the following if you want to use this pcm with non-interleaved mode
  18 */
  19/* #define USE_NONINTERLEAVE */
  20
  21/* NOTE: for using the non-interleaved mode with alsa-lib, you have to set
  22 * mmap_emulation flag to 1 in your .asoundrc, such like
  23 *
  24 *      pcm.emu8k {
  25 *              type plug
  26 *              slave.pcm {
  27 *                      type hw
  28 *                      card 0
  29 *                      device 1
  30 *                      mmap_emulation 1
  31 *              }
  32 *      }
  33 *
  34 * besides, for the time being, the non-interleaved mode doesn't work well on
  35 * alsa-lib...
  36 */
  37
  38
  39struct snd_emu8k_pcm {
  40        struct snd_emu8000 *emu;
  41        struct snd_pcm_substream *substream;
  42
  43        unsigned int allocated_bytes;
  44        struct snd_util_memblk *block;
  45        unsigned int offset;
  46        unsigned int buf_size;
  47        unsigned int period_size;
  48        unsigned int loop_start[2];
  49        unsigned int pitch;
  50        int panning[2];
  51        int last_ptr;
  52        int period_pos;
  53        int voices;
  54        unsigned int dram_opened: 1;
  55        unsigned int running: 1;
  56        unsigned int timer_running: 1;
  57        struct timer_list timer;
  58        spinlock_t timer_lock;
  59};
  60
  61#define LOOP_BLANK_SIZE         8
  62
  63
  64/*
  65 * open up channels for the simultaneous data transfer and playback
  66 */
  67static int
  68emu8k_open_dram_for_pcm(struct snd_emu8000 *emu, int channels)
  69{
  70        int i;
  71
  72        /* reserve up to 2 voices for playback */
  73        snd_emux_lock_voice(emu->emu, 0);
  74        if (channels > 1)
  75                snd_emux_lock_voice(emu->emu, 1);
  76
  77        /* reserve 28 voices for loading */
  78        for (i = channels + 1; i < EMU8000_DRAM_VOICES; i++) {
  79                unsigned int mode = EMU8000_RAM_WRITE;
  80                snd_emux_lock_voice(emu->emu, i);
  81#ifndef USE_NONINTERLEAVE
  82                if (channels > 1 && (i & 1) != 0)
  83                        mode |= EMU8000_RAM_RIGHT;
  84#endif
  85                snd_emu8000_dma_chan(emu, i, mode);
  86        }
  87
  88        /* assign voice 31 and 32 to ROM */
  89        EMU8000_VTFT_WRITE(emu, 30, 0);
  90        EMU8000_PSST_WRITE(emu, 30, 0x1d8);
  91        EMU8000_CSL_WRITE(emu, 30, 0x1e0);
  92        EMU8000_CCCA_WRITE(emu, 30, 0x1d8);
  93        EMU8000_VTFT_WRITE(emu, 31, 0);
  94        EMU8000_PSST_WRITE(emu, 31, 0x1d8);
  95        EMU8000_CSL_WRITE(emu, 31, 0x1e0);
  96        EMU8000_CCCA_WRITE(emu, 31, 0x1d8);
  97
  98        return 0;
  99}
 100
 101/*
 102 */
 103static void
 104snd_emu8000_write_wait(struct snd_emu8000 *emu, int can_schedule)
 105{
 106        while ((EMU8000_SMALW_READ(emu) & 0x80000000) != 0) {
 107                if (can_schedule) {
 108                        schedule_timeout_interruptible(1);
 109                        if (signal_pending(current))
 110                                break;
 111                }
 112        }
 113}
 114
 115/*
 116 * close all channels
 117 */
 118static void
 119emu8k_close_dram(struct snd_emu8000 *emu)
 120{
 121        int i;
 122
 123        for (i = 0; i < 2; i++)
 124                snd_emux_unlock_voice(emu->emu, i);
 125        for (; i < EMU8000_DRAM_VOICES; i++) {
 126                snd_emu8000_dma_chan(emu, i, EMU8000_RAM_CLOSE);
 127                snd_emux_unlock_voice(emu->emu, i);
 128        }
 129}
 130
 131/*
 132 * convert Hz to AWE32 rate offset (see emux/soundfont.c)
 133 */
 134
 135#define OFFSET_SAMPLERATE       1011119         /* base = 44100 */
 136#define SAMPLERATE_RATIO        4096
 137
 138static int calc_rate_offset(int hz)
 139{
 140        return snd_sf_linear_to_log(hz, OFFSET_SAMPLERATE, SAMPLERATE_RATIO);
 141}
 142
 143
 144/*
 145 */
 146
 147static const struct snd_pcm_hardware emu8k_pcm_hw = {
 148#ifdef USE_NONINTERLEAVE
 149        .info =                 SNDRV_PCM_INFO_NONINTERLEAVED,
 150#else
 151        .info =                 SNDRV_PCM_INFO_INTERLEAVED,
 152#endif
 153        .formats =              SNDRV_PCM_FMTBIT_S16_LE,
 154        .rates =                SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
 155        .rate_min =             4000,
 156        .rate_max =             48000,
 157        .channels_min =         1,
 158        .channels_max =         2,
 159        .buffer_bytes_max =     (128*1024),
 160        .period_bytes_min =     1024,
 161        .period_bytes_max =     (128*1024),
 162        .periods_min =          2,
 163        .periods_max =          1024,
 164        .fifo_size =            0,
 165
 166};
 167
 168/*
 169 * get the current position at the given channel from CCCA register
 170 */
 171static inline int emu8k_get_curpos(struct snd_emu8k_pcm *rec, int ch)
 172{
 173        int val = EMU8000_CCCA_READ(rec->emu, ch) & 0xfffffff;
 174        val -= rec->loop_start[ch] - 1;
 175        return val;
 176}
 177
 178
 179/*
 180 * timer interrupt handler
 181 * check the current position and update the period if necessary.
 182 */
 183static void emu8k_pcm_timer_func(struct timer_list *t)
 184{
 185        struct snd_emu8k_pcm *rec = from_timer(rec, t, timer);
 186        int ptr, delta;
 187
 188        spin_lock(&rec->timer_lock);
 189        /* update the current pointer */
 190        ptr = emu8k_get_curpos(rec, 0);
 191        if (ptr < rec->last_ptr)
 192                delta = ptr + rec->buf_size - rec->last_ptr;
 193        else
 194                delta = ptr - rec->last_ptr;
 195        rec->period_pos += delta;
 196        rec->last_ptr = ptr;
 197
 198        /* reprogram timer */
 199        mod_timer(&rec->timer, jiffies + 1);
 200
 201        /* update period */
 202        if (rec->period_pos >= (int)rec->period_size) {
 203                rec->period_pos %= rec->period_size;
 204                spin_unlock(&rec->timer_lock);
 205                snd_pcm_period_elapsed(rec->substream);
 206                return;
 207        }
 208        spin_unlock(&rec->timer_lock);
 209}
 210
 211
 212/*
 213 * open pcm
 214 * creating an instance here
 215 */
 216static int emu8k_pcm_open(struct snd_pcm_substream *subs)
 217{
 218        struct snd_emu8000 *emu = snd_pcm_substream_chip(subs);
 219        struct snd_emu8k_pcm *rec;
 220        struct snd_pcm_runtime *runtime = subs->runtime;
 221
 222        rec = kzalloc(sizeof(*rec), GFP_KERNEL);
 223        if (! rec)
 224                return -ENOMEM;
 225
 226        rec->emu = emu;
 227        rec->substream = subs;
 228        runtime->private_data = rec;
 229
 230        spin_lock_init(&rec->timer_lock);
 231        timer_setup(&rec->timer, emu8k_pcm_timer_func, 0);
 232
 233        runtime->hw = emu8k_pcm_hw;
 234        runtime->hw.buffer_bytes_max = emu->mem_size - LOOP_BLANK_SIZE * 3;
 235        runtime->hw.period_bytes_max = runtime->hw.buffer_bytes_max / 2;
 236
 237        /* use timer to update periods.. (specified in msec) */
 238        snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
 239                                     (1000000 + HZ - 1) / HZ, UINT_MAX);
 240
 241        return 0;
 242}
 243
 244static int emu8k_pcm_close(struct snd_pcm_substream *subs)
 245{
 246        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 247        kfree(rec);
 248        subs->runtime->private_data = NULL;
 249        return 0;
 250}
 251
 252/*
 253 * calculate pitch target
 254 */
 255static int calc_pitch_target(int pitch)
 256{
 257        int ptarget = 1 << (pitch >> 12);
 258        if (pitch & 0x800) ptarget += (ptarget * 0x102e) / 0x2710;
 259        if (pitch & 0x400) ptarget += (ptarget * 0x764) / 0x2710;
 260        if (pitch & 0x200) ptarget += (ptarget * 0x389) / 0x2710;
 261        ptarget += (ptarget >> 1);
 262        if (ptarget > 0xffff) ptarget = 0xffff;
 263        return ptarget;
 264}
 265
 266/*
 267 * set up the voice
 268 */
 269static void setup_voice(struct snd_emu8k_pcm *rec, int ch)
 270{
 271        struct snd_emu8000 *hw = rec->emu;
 272        unsigned int temp;
 273
 274        /* channel to be silent and idle */
 275        EMU8000_DCYSUSV_WRITE(hw, ch, 0x0080);
 276        EMU8000_VTFT_WRITE(hw, ch, 0x0000FFFF);
 277        EMU8000_CVCF_WRITE(hw, ch, 0x0000FFFF);
 278        EMU8000_PTRX_WRITE(hw, ch, 0);
 279        EMU8000_CPF_WRITE(hw, ch, 0);
 280
 281        /* pitch offset */
 282        EMU8000_IP_WRITE(hw, ch, rec->pitch);
 283        /* set envelope parameters */
 284        EMU8000_ENVVAL_WRITE(hw, ch, 0x8000);
 285        EMU8000_ATKHLD_WRITE(hw, ch, 0x7f7f);
 286        EMU8000_DCYSUS_WRITE(hw, ch, 0x7f7f);
 287        EMU8000_ENVVOL_WRITE(hw, ch, 0x8000);
 288        EMU8000_ATKHLDV_WRITE(hw, ch, 0x7f7f);
 289        /* decay/sustain parameter for volume envelope is used
 290           for triggerg the voice */
 291        /* modulation envelope heights */
 292        EMU8000_PEFE_WRITE(hw, ch, 0x0);
 293        /* lfo1/2 delay */
 294        EMU8000_LFO1VAL_WRITE(hw, ch, 0x8000);
 295        EMU8000_LFO2VAL_WRITE(hw, ch, 0x8000);
 296        /* lfo1 pitch & cutoff shift */
 297        EMU8000_FMMOD_WRITE(hw, ch, 0);
 298        /* lfo1 volume & freq */
 299        EMU8000_TREMFRQ_WRITE(hw, ch, 0);
 300        /* lfo2 pitch & freq */
 301        EMU8000_FM2FRQ2_WRITE(hw, ch, 0);
 302        /* pan & loop start */
 303        temp = rec->panning[ch];
 304        temp = (temp <<24) | ((unsigned int)rec->loop_start[ch] - 1);
 305        EMU8000_PSST_WRITE(hw, ch, temp);
 306        /* chorus & loop end (chorus 8bit, MSB) */
 307        temp = 0; // chorus
 308        temp = (temp << 24) | ((unsigned int)rec->loop_start[ch] + rec->buf_size - 1);
 309        EMU8000_CSL_WRITE(hw, ch, temp);
 310        /* Q & current address (Q 4bit value, MSB) */
 311        temp = 0; // filterQ
 312        temp = (temp << 28) | ((unsigned int)rec->loop_start[ch] - 1);
 313        EMU8000_CCCA_WRITE(hw, ch, temp);
 314        /* clear unknown registers */
 315        EMU8000_00A0_WRITE(hw, ch, 0);
 316        EMU8000_0080_WRITE(hw, ch, 0);
 317}
 318
 319/*
 320 * trigger the voice
 321 */
 322static void start_voice(struct snd_emu8k_pcm *rec, int ch)
 323{
 324        unsigned long flags;
 325        struct snd_emu8000 *hw = rec->emu;
 326        unsigned int temp, aux;
 327        int pt = calc_pitch_target(rec->pitch);
 328
 329        /* cutoff and volume */
 330        EMU8000_IFATN_WRITE(hw, ch, 0xff00);
 331        EMU8000_VTFT_WRITE(hw, ch, 0xffff);
 332        EMU8000_CVCF_WRITE(hw, ch, 0xffff);
 333        /* trigger envelope */
 334        EMU8000_DCYSUSV_WRITE(hw, ch, 0x7f7f);
 335        /* set reverb and pitch target */
 336        temp = 0; // reverb
 337        if (rec->panning[ch] == 0)
 338                aux = 0xff;
 339        else
 340                aux = (-rec->panning[ch]) & 0xff;
 341        temp = (temp << 8) | (pt << 16) | aux;
 342        EMU8000_PTRX_WRITE(hw, ch, temp);
 343        EMU8000_CPF_WRITE(hw, ch, pt << 16);
 344
 345        /* start timer */
 346        spin_lock_irqsave(&rec->timer_lock, flags);
 347        if (! rec->timer_running) {
 348                mod_timer(&rec->timer, jiffies + 1);
 349                rec->timer_running = 1;
 350        }
 351        spin_unlock_irqrestore(&rec->timer_lock, flags);
 352}
 353
 354/*
 355 * stop the voice immediately
 356 */
 357static void stop_voice(struct snd_emu8k_pcm *rec, int ch)
 358{
 359        unsigned long flags;
 360        struct snd_emu8000 *hw = rec->emu;
 361
 362        EMU8000_DCYSUSV_WRITE(hw, ch, 0x807F);
 363
 364        /* stop timer */
 365        spin_lock_irqsave(&rec->timer_lock, flags);
 366        if (rec->timer_running) {
 367                del_timer(&rec->timer);
 368                rec->timer_running = 0;
 369        }
 370        spin_unlock_irqrestore(&rec->timer_lock, flags);
 371}
 372
 373static int emu8k_pcm_trigger(struct snd_pcm_substream *subs, int cmd)
 374{
 375        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 376        int ch;
 377
 378        switch (cmd) {
 379        case SNDRV_PCM_TRIGGER_START:
 380                for (ch = 0; ch < rec->voices; ch++)
 381                        start_voice(rec, ch);
 382                rec->running = 1;
 383                break;
 384        case SNDRV_PCM_TRIGGER_STOP:
 385                rec->running = 0;
 386                for (ch = 0; ch < rec->voices; ch++)
 387                        stop_voice(rec, ch);
 388                break;
 389        default:
 390                return -EINVAL;
 391        }
 392        return 0;
 393}
 394
 395
 396/*
 397 * copy / silence ops
 398 */
 399
 400/*
 401 * this macro should be inserted in the copy/silence loops
 402 * to reduce the latency.  without this, the system will hang up
 403 * during the whole loop.
 404 */
 405#define CHECK_SCHEDULER() \
 406do { \
 407        cond_resched();\
 408        if (signal_pending(current))\
 409                return -EAGAIN;\
 410} while (0)
 411
 412enum {
 413        COPY_USER, COPY_KERNEL, FILL_SILENCE,
 414};
 415
 416#define GET_VAL(sval, buf, mode)                                        \
 417        do {                                                            \
 418                switch (mode) {                                         \
 419                case FILL_SILENCE:                                      \
 420                        sval = 0;                                       \
 421                        break;                                          \
 422                case COPY_KERNEL:                                       \
 423                        sval = *buf++;                                  \
 424                        break;                                          \
 425                default:                                                \
 426                        if (get_user(sval, (unsigned short __user *)buf)) \
 427                                return -EFAULT;                         \
 428                        buf++;                                          \
 429                        break;                                          \
 430                }                                                       \
 431        } while (0)
 432
 433#ifdef USE_NONINTERLEAVE
 434
 435#define LOOP_WRITE(rec, offset, _buf, count, mode)              \
 436        do {                                                    \
 437                struct snd_emu8000 *emu = (rec)->emu;           \
 438                unsigned short *buf = (__force unsigned short *)(_buf); \
 439                snd_emu8000_write_wait(emu, 1);                 \
 440                EMU8000_SMALW_WRITE(emu, offset);               \
 441                while (count > 0) {                             \
 442                        unsigned short sval;                    \
 443                        CHECK_SCHEDULER();                      \
 444                        GET_VAL(sval, buf, mode);               \
 445                        EMU8000_SMLD_WRITE(emu, sval);          \
 446                        count--;                                \
 447                }                                               \
 448        } while (0)
 449
 450/* copy one channel block */
 451static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
 452                          int voice, unsigned long pos,
 453                          void __user *src, unsigned long count)
 454{
 455        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 456
 457        /* convert to word unit */
 458        pos = (pos << 1) + rec->loop_start[voice];
 459        count <<= 1;
 460        LOOP_WRITE(rec, pos, src, count, COPY_USER);
 461        return 0;
 462}
 463
 464static int emu8k_pcm_copy_kernel(struct snd_pcm_substream *subs,
 465                                 int voice, unsigned long pos,
 466                                 void *src, unsigned long count)
 467{
 468        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 469
 470        /* convert to word unit */
 471        pos = (pos << 1) + rec->loop_start[voice];
 472        count <<= 1;
 473        LOOP_WRITE(rec, pos, src, count, COPY_KERNEL);
 474        return 0;
 475}
 476
 477/* make a channel block silence */
 478static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
 479                             int voice, unsigned long pos, unsigned long count)
 480{
 481        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 482
 483        /* convert to word unit */
 484        pos = (pos << 1) + rec->loop_start[voice];
 485        count <<= 1;
 486        LOOP_WRITE(rec, pos, NULL, count, FILL_SILENCE);
 487        return 0;
 488}
 489
 490#else /* interleave */
 491
 492#define LOOP_WRITE(rec, pos, _buf, count, mode)                         \
 493        do {                                                            \
 494                struct snd_emu8000 *emu = rec->emu;                     \
 495                unsigned short *buf = (__force unsigned short *)(_buf); \
 496                snd_emu8000_write_wait(emu, 1);                         \
 497                EMU8000_SMALW_WRITE(emu, pos + rec->loop_start[0]);     \
 498                if (rec->voices > 1)                                    \
 499                        EMU8000_SMARW_WRITE(emu, pos + rec->loop_start[1]); \
 500                while (count > 0) {                                     \
 501                        unsigned short sval;                            \
 502                        CHECK_SCHEDULER();                              \
 503                        GET_VAL(sval, buf, mode);                       \
 504                        EMU8000_SMLD_WRITE(emu, sval);                  \
 505                        if (rec->voices > 1) {                          \
 506                                CHECK_SCHEDULER();                      \
 507                                GET_VAL(sval, buf, mode);               \
 508                                EMU8000_SMRD_WRITE(emu, sval);          \
 509                        }                                               \
 510                        count--;                                        \
 511                }                                                       \
 512        } while (0)
 513
 514
 515/*
 516 * copy the interleaved data can be done easily by using
 517 * DMA "left" and "right" channels on emu8k engine.
 518 */
 519static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
 520                          int voice, unsigned long pos,
 521                          void __user *src, unsigned long count)
 522{
 523        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 524
 525        /* convert to frames */
 526        pos = bytes_to_frames(subs->runtime, pos);
 527        count = bytes_to_frames(subs->runtime, count);
 528        LOOP_WRITE(rec, pos, src, count, COPY_USER);
 529        return 0;
 530}
 531
 532static int emu8k_pcm_copy_kernel(struct snd_pcm_substream *subs,
 533                                 int voice, unsigned long pos,
 534                                 void *src, unsigned long count)
 535{
 536        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 537
 538        /* convert to frames */
 539        pos = bytes_to_frames(subs->runtime, pos);
 540        count = bytes_to_frames(subs->runtime, count);
 541        LOOP_WRITE(rec, pos, src, count, COPY_KERNEL);
 542        return 0;
 543}
 544
 545static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
 546                             int voice, unsigned long pos, unsigned long count)
 547{
 548        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 549
 550        /* convert to frames */
 551        pos = bytes_to_frames(subs->runtime, pos);
 552        count = bytes_to_frames(subs->runtime, count);
 553        LOOP_WRITE(rec, pos, NULL, count, FILL_SILENCE);
 554        return 0;
 555}
 556#endif
 557
 558
 559/*
 560 * allocate a memory block
 561 */
 562static int emu8k_pcm_hw_params(struct snd_pcm_substream *subs,
 563                               struct snd_pcm_hw_params *hw_params)
 564{
 565        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 566
 567        if (rec->block) {
 568                /* reallocation - release the old block */
 569                snd_util_mem_free(rec->emu->memhdr, rec->block);
 570                rec->block = NULL;
 571        }
 572
 573        rec->allocated_bytes = params_buffer_bytes(hw_params) + LOOP_BLANK_SIZE * 4;
 574        rec->block = snd_util_mem_alloc(rec->emu->memhdr, rec->allocated_bytes);
 575        if (! rec->block)
 576                return -ENOMEM;
 577        rec->offset = EMU8000_DRAM_OFFSET + (rec->block->offset >> 1); /* in word */
 578        /* at least dma_bytes must be set for non-interleaved mode */
 579        subs->dma_buffer.bytes = params_buffer_bytes(hw_params);
 580
 581        return 0;
 582}
 583
 584/*
 585 * free the memory block
 586 */
 587static int emu8k_pcm_hw_free(struct snd_pcm_substream *subs)
 588{
 589        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 590
 591        if (rec->block) {
 592                int ch;
 593                for (ch = 0; ch < rec->voices; ch++)
 594                        stop_voice(rec, ch); // to be sure
 595                if (rec->dram_opened)
 596                        emu8k_close_dram(rec->emu);
 597                snd_util_mem_free(rec->emu->memhdr, rec->block);
 598                rec->block = NULL;
 599        }
 600        return 0;
 601}
 602
 603/*
 604 */
 605static int emu8k_pcm_prepare(struct snd_pcm_substream *subs)
 606{
 607        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 608
 609        rec->pitch = 0xe000 + calc_rate_offset(subs->runtime->rate);
 610        rec->last_ptr = 0;
 611        rec->period_pos = 0;
 612
 613        rec->buf_size = subs->runtime->buffer_size;
 614        rec->period_size = subs->runtime->period_size;
 615        rec->voices = subs->runtime->channels;
 616        rec->loop_start[0] = rec->offset + LOOP_BLANK_SIZE;
 617        if (rec->voices > 1)
 618                rec->loop_start[1] = rec->loop_start[0] + rec->buf_size + LOOP_BLANK_SIZE;
 619        if (rec->voices > 1) {
 620                rec->panning[0] = 0xff;
 621                rec->panning[1] = 0x00;
 622        } else
 623                rec->panning[0] = 0x80;
 624
 625        if (! rec->dram_opened) {
 626                int err, i, ch;
 627
 628                snd_emux_terminate_all(rec->emu->emu);
 629                err = emu8k_open_dram_for_pcm(rec->emu, rec->voices);
 630                if (err)
 631                        return err;
 632                rec->dram_opened = 1;
 633
 634                /* clear loop blanks */
 635                snd_emu8000_write_wait(rec->emu, 0);
 636                EMU8000_SMALW_WRITE(rec->emu, rec->offset);
 637                for (i = 0; i < LOOP_BLANK_SIZE; i++)
 638                        EMU8000_SMLD_WRITE(rec->emu, 0);
 639                for (ch = 0; ch < rec->voices; ch++) {
 640                        EMU8000_SMALW_WRITE(rec->emu, rec->loop_start[ch] + rec->buf_size);
 641                        for (i = 0; i < LOOP_BLANK_SIZE; i++)
 642                                EMU8000_SMLD_WRITE(rec->emu, 0);
 643                }
 644        }
 645
 646        setup_voice(rec, 0);
 647        if (rec->voices > 1)
 648                setup_voice(rec, 1);
 649        return 0;
 650}
 651
 652static snd_pcm_uframes_t emu8k_pcm_pointer(struct snd_pcm_substream *subs)
 653{
 654        struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 655        if (rec->running)
 656                return emu8k_get_curpos(rec, 0);
 657        return 0;
 658}
 659
 660
 661static const struct snd_pcm_ops emu8k_pcm_ops = {
 662        .open =         emu8k_pcm_open,
 663        .close =        emu8k_pcm_close,
 664        .hw_params =    emu8k_pcm_hw_params,
 665        .hw_free =      emu8k_pcm_hw_free,
 666        .prepare =      emu8k_pcm_prepare,
 667        .trigger =      emu8k_pcm_trigger,
 668        .pointer =      emu8k_pcm_pointer,
 669        .copy_user =    emu8k_pcm_copy,
 670        .copy_kernel =  emu8k_pcm_copy_kernel,
 671        .fill_silence = emu8k_pcm_silence,
 672};
 673
 674
 675static void snd_emu8000_pcm_free(struct snd_pcm *pcm)
 676{
 677        struct snd_emu8000 *emu = pcm->private_data;
 678        emu->pcm = NULL;
 679}
 680
 681int snd_emu8000_pcm_new(struct snd_card *card, struct snd_emu8000 *emu, int index)
 682{
 683        struct snd_pcm *pcm;
 684        int err;
 685
 686        err = snd_pcm_new(card, "Emu8000 PCM", index, 1, 0, &pcm);
 687        if (err < 0)
 688                return err;
 689        pcm->private_data = emu;
 690        pcm->private_free = snd_emu8000_pcm_free;
 691        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &emu8k_pcm_ops);
 692        emu->pcm = pcm;
 693
 694        snd_device_register(card, pcm);
 695
 696        return 0;
 697}
 698