sound/isa/sb/emu8000_pcm.c

   1 /*
   2  * pcm emulation on emu8000 wavetable
   3  *
   4  *  Copyright (C) 2002 Takashi Iwai <tiwai@suse.de>
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  */
  20
  21 #include "emu8000_local.h"
  22 #include <linux/init.h>
  23 #include <sound/initval.h>
  24 #include <sound/pcm.h>
  25
  26 /*
  27  * define the following if you want to use this pcm with non-interleaved mode
  28  */
  29 /* #define USE_NONINTERLEAVE */
  30
  31 /* NOTE: for using the non-interleaved mode with alsa-lib, you have to set
  32  * mmap_emulation flag to 1 in your .asoundrc, such like
  33  *
  34  *      pcm.emu8k {
  35  *              type plug
  36  *              slave.pcm {
  37  *                      type hw
  38  *                      card 0
  39  *                      device 1
  40  *                      mmap_emulation 1
  41  *              }
  42  *      }
  43  *
  44  * besides, for the time being, the non-interleaved mode doesn't work well on
  45  * alsa-lib...
  46  */
  47
  48
  49 struct snd_emu8k_pcm {
  50         struct snd_emu8000 *emu;
  51         struct snd_pcm_substream *substream;
  52
  53         unsigned int allocated_bytes;
  54         struct snd_util_memblk *block;
  55         unsigned int offset;
  56         unsigned int buf_size;
  57         unsigned int period_size;
  58         unsigned int loop_start[2];
  59         unsigned int pitch;
  60         int panning[2];
  61         int last_ptr;
  62         int period_pos;
  63         int voices;
  64         unsigned int dram_opened: 1;
  65         unsigned int running: 1;
  66         unsigned int timer_running: 1;
  67         struct timer_list timer;
  68         spinlock_t timer_lock;
  69 };
  70
  71 #define LOOP_BLANK_SIZE         8
  72
  73
  74 /*
  75  * open up channels for the simultaneous data transfer and playback
  76  */
  77 static int
  78 emu8k_open_dram_for_pcm(struct snd_emu8000 *emu, int channels)
  79 {
  80         int i;
  81
  82         /* reserve up to 2 voices for playback */
  83         snd_emux_lock_voice(emu->emu, 0);
  84         if (channels > 1)
  85                 snd_emux_lock_voice(emu->emu, 1);
  86
  87         /* reserve 28 voices for loading */
  88         for (i = channels + 1; i < EMU8000_DRAM_VOICES; i++) {
  89                 unsigned int mode = EMU8000_RAM_WRITE;
  90                 snd_emux_lock_voice(emu->emu, i);
  91 #ifndef USE_NONINTERLEAVE
  92                 if (channels > 1 && (i & 1) != 0)
  93                         mode |= EMU8000_RAM_RIGHT;
  94 #endif
  95                 snd_emu8000_dma_chan(emu, i, mode);
  96         }
  97
  98         /* assign voice 31 and 32 to ROM */
  99         EMU8000_VTFT_WRITE(emu, 30, 0);
 100         EMU8000_PSST_WRITE(emu, 30, 0x1d8);
 101         EMU8000_CSL_WRITE(emu, 30, 0x1e0);
 102         EMU8000_CCCA_WRITE(emu, 30, 0x1d8);
 103         EMU8000_VTFT_WRITE(emu, 31, 0);
 104         EMU8000_PSST_WRITE(emu, 31, 0x1d8);
 105         EMU8000_CSL_WRITE(emu, 31, 0x1e0);
 106         EMU8000_CCCA_WRITE(emu, 31, 0x1d8);
 107
 108         return 0;
 109 }
 110
 111 /*
 112  */
 113 static void
 114 snd_emu8000_write_wait(struct snd_emu8000 *emu, int can_schedule)
 115 {
 116         while ((EMU8000_SMALW_READ(emu) & 0x80000000) != 0) {
 117                 if (can_schedule) {
 118                         schedule_timeout_interruptible(1);
 119                         if (signal_pending(current))
 120                                 break;
 121                 }
 122         }
 123 }
 124
 125 /*
 126  * close all channels
 127  */
 128 static void
 129 emu8k_close_dram(struct snd_emu8000 *emu)
 130 {
 131         int i;
 132
 133         for (i = 0; i < 2; i++)
 134                 snd_emux_unlock_voice(emu->emu, i);
 135         for (; i < EMU8000_DRAM_VOICES; i++) {
 136                 snd_emu8000_dma_chan(emu, i, EMU8000_RAM_CLOSE);
 137                 snd_emux_unlock_voice(emu->emu, i);
 138         }
 139 }
 140
 141 /*
 142  * convert Hz to AWE32 rate offset (see emux/soundfont.c)
 143  */
 144
 145 #define OFFSET_SAMPLERATE       1011119         /* base = 44100 */
 146 #define SAMPLERATE_RATIO        4096
 147
 148 static int calc_rate_offset(int hz)
 149 {
 150         return snd_sf_linear_to_log(hz, OFFSET_SAMPLERATE, SAMPLERATE_RATIO);
 151 }
 152
 153
 154 /*
 155  */
 156
 157 static struct snd_pcm_hardware emu8k_pcm_hw = {
 158 #ifdef USE_NONINTERLEAVE
 159         .info =                 SNDRV_PCM_INFO_NONINTERLEAVED,
 160 #else
 161         .info =                 SNDRV_PCM_INFO_INTERLEAVED,
 162 #endif
 163         .formats =              SNDRV_PCM_FMTBIT_S16_LE,
 164         .rates =                SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
 165         .rate_min =             4000,
 166         .rate_max =             48000,
 167         .channels_min =         1,
 168         .channels_max =         2,
 169         .buffer_bytes_max =     (128*1024),
 170         .period_bytes_min =     1024,
 171         .period_bytes_max =     (128*1024),
 172         .periods_min =          2,
 173         .periods_max =          1024,
 174         .fifo_size =            0,
 175
 176 };
 177
 178 /*
 179  * get the current position at the given channel from CCCA register
 180  */
 181 static inline int emu8k_get_curpos(struct snd_emu8k_pcm *rec, int ch)
 182 {
 183         int val = EMU8000_CCCA_READ(rec->emu, ch) & 0xfffffff;
 184         val -= rec->loop_start[ch] - 1;
 185         return val;
 186 }
 187
 188
 189 /*
 190  * timer interrupt handler
 191  * check the current position and update the period if necessary.
 192  */
 193 static void emu8k_pcm_timer_func(unsigned long data)
 194 {
 195         struct snd_emu8k_pcm *rec = (struct snd_emu8k_pcm *)data;
 196         int ptr, delta;
 197
 198         spin_lock(&rec->timer_lock);
 199         /* update the current pointer */
 200         ptr = emu8k_get_curpos(rec, 0);
 201         if (ptr < rec->last_ptr)
 202                 delta = ptr + rec->buf_size - rec->last_ptr;
 203         else
 204                 delta = ptr - rec->last_ptr;
 205         rec->period_pos += delta;
 206         rec->last_ptr = ptr;
 207
 208         /* reprogram timer */
 209         rec->timer.expires = jiffies + 1;
 210         add_timer(&rec->timer);
 211
 212         /* update period */
 213         if (rec->period_pos >= (int)rec->period_size) {
 214                 rec->period_pos %= rec->period_size;
 215                 spin_unlock(&rec->timer_lock);
 216                 snd_pcm_period_elapsed(rec->substream);
 217                 return;
 218         }
 219         spin_unlock(&rec->timer_lock);
 220 }
 221
 222
 223 /*
 224  * open pcm
 225  * creating an instance here
 226  */
 227 static int emu8k_pcm_open(struct snd_pcm_substream *subs)
 228 {
 229         struct snd_emu8000 *emu = snd_pcm_substream_chip(subs);
 230         struct snd_emu8k_pcm *rec;
 231         struct snd_pcm_runtime *runtime = subs->runtime;
 232
 233         rec = kzalloc(sizeof(*rec), GFP_KERNEL);
 234         if (! rec)
 235                 return -ENOMEM;
 236
 237         rec->emu = emu;
 238         rec->substream = subs;
 239         runtime->private_data = rec;
 240
 241         spin_lock_init(&rec->timer_lock);
 242         init_timer(&rec->timer);
 243         rec->timer.function = emu8k_pcm_timer_func;
 244         rec->timer.data = (unsigned long)rec;
 245
 246         runtime->hw = emu8k_pcm_hw;
 247         runtime->hw.buffer_bytes_max = emu->mem_size - LOOP_BLANK_SIZE * 3;
 248         runtime->hw.period_bytes_max = runtime->hw.buffer_bytes_max / 2;
 249
 250         /* use timer to update periods.. (specified in msec) */
 251         snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
 252                                      (1000000 + HZ - 1) / HZ, UINT_MAX);
 253
 254         return 0;
 255 }
 256
 257 static int emu8k_pcm_close(struct snd_pcm_substream *subs)
 258 {
 259         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 260         kfree(rec);
 261         subs->runtime->private_data = NULL;
 262         return 0;
 263 }
 264
 265 /*
 266  * calculate pitch target
 267  */
 268 static int calc_pitch_target(int pitch)
 269 {
 270         int ptarget = 1 << (pitch >> 12);
 271         if (pitch & 0x800) ptarget += (ptarget * 0x102e) / 0x2710;
 272         if (pitch & 0x400) ptarget += (ptarget * 0x764) / 0x2710;
 273         if (pitch & 0x200) ptarget += (ptarget * 0x389) / 0x2710;
 274         ptarget += (ptarget >> 1);
 275         if (ptarget > 0xffff) ptarget = 0xffff;
 276         return ptarget;
 277 }
 278
 279 /*
 280  * set up the voice
 281  */
 282 static void setup_voice(struct snd_emu8k_pcm *rec, int ch)
 283 {
 284         struct snd_emu8000 *hw = rec->emu;
 285         unsigned int temp;
 286
 287         /* channel to be silent and idle */
 288         EMU8000_DCYSUSV_WRITE(hw, ch, 0x0080);
 289         EMU8000_VTFT_WRITE(hw, ch, 0x0000FFFF);
 290         EMU8000_CVCF_WRITE(hw, ch, 0x0000FFFF);
 291         EMU8000_PTRX_WRITE(hw, ch, 0);
 292         EMU8000_CPF_WRITE(hw, ch, 0);
 293
 294         /* pitch offset */
 295         EMU8000_IP_WRITE(hw, ch, rec->pitch);
 296         /* set envelope parameters */
 297         EMU8000_ENVVAL_WRITE(hw, ch, 0x8000);
 298         EMU8000_ATKHLD_WRITE(hw, ch, 0x7f7f);
 299         EMU8000_DCYSUS_WRITE(hw, ch, 0x7f7f);
 300         EMU8000_ENVVOL_WRITE(hw, ch, 0x8000);
 301         EMU8000_ATKHLDV_WRITE(hw, ch, 0x7f7f);
 302         /* decay/sustain parameter for volume envelope is used
 303            for triggerg the voice */
 304         /* modulation envelope heights */
 305         EMU8000_PEFE_WRITE(hw, ch, 0x0);
 306         /* lfo1/2 delay */
 307         EMU8000_LFO1VAL_WRITE(hw, ch, 0x8000);
 308         EMU8000_LFO2VAL_WRITE(hw, ch, 0x8000);
 309         /* lfo1 pitch & cutoff shift */
 310         EMU8000_FMMOD_WRITE(hw, ch, 0);
 311         /* lfo1 volume & freq */
 312         EMU8000_TREMFRQ_WRITE(hw, ch, 0);
 313         /* lfo2 pitch & freq */
 314         EMU8000_FM2FRQ2_WRITE(hw, ch, 0);
 315         /* pan & loop start */
 316         temp = rec->panning[ch];
 317         temp = (temp <<24) | ((unsigned int)rec->loop_start[ch] - 1);
 318         EMU8000_PSST_WRITE(hw, ch, temp);
 319         /* chorus & loop end (chorus 8bit, MSB) */
 320         temp = 0; // chorus
 321         temp = (temp << 24) | ((unsigned int)rec->loop_start[ch] + rec->buf_size - 1);
 322         EMU8000_CSL_WRITE(hw, ch, temp);
 323         /* Q & current address (Q 4bit value, MSB) */
 324         temp = 0; // filterQ
 325         temp = (temp << 28) | ((unsigned int)rec->loop_start[ch] - 1);
 326         EMU8000_CCCA_WRITE(hw, ch, temp);
 327         /* clear unknown registers */
 328         EMU8000_00A0_WRITE(hw, ch, 0);
 329         EMU8000_0080_WRITE(hw, ch, 0);
 330 }
 331
 332 /*
 333  * trigger the voice
 334  */
 335 static void start_voice(struct snd_emu8k_pcm *rec, int ch)
 336 {
 337         unsigned long flags;
 338         struct snd_emu8000 *hw = rec->emu;
 339         unsigned int temp, aux;
 340         int pt = calc_pitch_target(rec->pitch);
 341
 342         /* cutoff and volume */
 343         EMU8000_IFATN_WRITE(hw, ch, 0xff00);
 344         EMU8000_VTFT_WRITE(hw, ch, 0xffff);
 345         EMU8000_CVCF_WRITE(hw, ch, 0xffff);
 346         /* trigger envelope */
 347         EMU8000_DCYSUSV_WRITE(hw, ch, 0x7f7f);
 348         /* set reverb and pitch target */
 349         temp = 0; // reverb
 350         if (rec->panning[ch] == 0)
 351                 aux = 0xff;
 352         else
 353                 aux = (-rec->panning[ch]) & 0xff;
 354         temp = (temp << 8) | (pt << 16) | aux;
 355         EMU8000_PTRX_WRITE(hw, ch, temp);
 356         EMU8000_CPF_WRITE(hw, ch, pt << 16);
 357
 358         /* start timer */
 359         spin_lock_irqsave(&rec->timer_lock, flags);
 360         if (! rec->timer_running) {
 361                 rec->timer.expires = jiffies + 1;
 362                 add_timer(&rec->timer);
 363                 rec->timer_running = 1;
 364         }
 365         spin_unlock_irqrestore(&rec->timer_lock, flags);
 366 }
 367
 368 /*
 369  * stop the voice immediately
 370  */
 371 static void stop_voice(struct snd_emu8k_pcm *rec, int ch)
 372 {
 373         unsigned long flags;
 374         struct snd_emu8000 *hw = rec->emu;
 375
 376         EMU8000_DCYSUSV_WRITE(hw, ch, 0x807F);
 377
 378         /* stop timer */
 379         spin_lock_irqsave(&rec->timer_lock, flags);
 380         if (rec->timer_running) {
 381                 del_timer(&rec->timer);
 382                 rec->timer_running = 0;
 383         }
 384         spin_unlock_irqrestore(&rec->timer_lock, flags);
 385 }
 386
 387 static int emu8k_pcm_trigger(struct snd_pcm_substream *subs, int cmd)
 388 {
 389         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 390         int ch;
 391
 392         switch (cmd) {
 393         case SNDRV_PCM_TRIGGER_START:
 394                 for (ch = 0; ch < rec->voices; ch++)
 395                         start_voice(rec, ch);
 396                 rec->running = 1;
 397                 break;
 398         case SNDRV_PCM_TRIGGER_STOP:
 399                 rec->running = 0;
 400                 for (ch = 0; ch < rec->voices; ch++)
 401                         stop_voice(rec, ch);
 402                 break;
 403         default:
 404                 return -EINVAL;
 405         }
 406         return 0;
 407 }
 408
 409
 410 /*
 411  * copy / silence ops
 412  */
 413
 414 /*
 415  * this macro should be inserted in the copy/silence loops
 416  * to reduce the latency.  without this, the system will hang up
 417  * during the whole loop.
 418  */
 419 #define CHECK_SCHEDULER() \
 420 do { \
 421         cond_resched();\
 422         if (signal_pending(current))\
 423                 return -EAGAIN;\
 424 } while (0)
 425
 426
 427 #ifdef USE_NONINTERLEAVE
 428 /* copy one channel block */
 429 static int emu8k_transfer_block(struct snd_emu8000 *emu, int offset, unsigned short *buf, int count)
 430 {
 431         EMU8000_SMALW_WRITE(emu, offset);
 432         while (count > 0) {
 433                 unsigned short sval;
 434                 CHECK_SCHEDULER();
 435                 get_user(sval, buf);
 436                 EMU8000_SMLD_WRITE(emu, sval);
 437                 buf++;
 438                 count--;
 439         }
 440         return 0;
 441 }
 442
 443 static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
 444                           int voice,
 445                           snd_pcm_uframes_t pos,
 446                           void *src,
 447                           snd_pcm_uframes_t count)
 448 {
 449         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 450         struct snd_emu8000 *emu = rec->emu;
 451
 452         snd_emu8000_write_wait(emu, 1);
 453         if (voice == -1) {
 454                 unsigned short *buf = src;
 455                 int i, err;
 456                 count /= rec->voices;
 457                 for (i = 0; i < rec->voices; i++) {
 458                         err = emu8k_transfer_block(emu, pos + rec->loop_start[i], buf, count);
 459                         if (err < 0)
 460                                 return err;
 461                         buf += count;
 462                 }
 463                 return 0;
 464         } else {
 465                 return emu8k_transfer_block(emu, pos + rec->loop_start[voice], src, count);
 466         }
 467 }
 468
 469 /* make a channel block silence */
 470 static int emu8k_silence_block(struct snd_emu8000 *emu, int offset, int count)
 471 {
 472         EMU8000_SMALW_WRITE(emu, offset);
 473         while (count > 0) {
 474                 CHECK_SCHEDULER();
 475                 EMU8000_SMLD_WRITE(emu, 0);
 476                 count--;
 477         }
 478         return 0;
 479 }
 480
 481 static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
 482                              int voice,
 483                              snd_pcm_uframes_t pos,
 484                              snd_pcm_uframes_t count)
 485 {
 486         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 487         struct snd_emu8000 *emu = rec->emu;
 488
 489         snd_emu8000_write_wait(emu, 1);
 490         if (voice == -1 && rec->voices == 1)
 491                 voice = 0;
 492         if (voice == -1) {
 493                 int err;
 494                 err = emu8k_silence_block(emu, pos + rec->loop_start[0], count / 2);
 495                 if (err < 0)
 496                         return err;
 497                 return emu8k_silence_block(emu, pos + rec->loop_start[1], count / 2);
 498         } else {
 499                 return emu8k_silence_block(emu, pos + rec->loop_start[voice], count);
 500         }
 501 }
 502
 503 #else /* interleave */
 504
 505 /*
 506  * copy the interleaved data can be done easily by using
 507  * DMA "left" and "right" channels on emu8k engine.
 508  */
 509 static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
 510                           int voice,
 511                           snd_pcm_uframes_t pos,
 512                           void __user *src,
 513                           snd_pcm_uframes_t count)
 514 {
 515         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 516         struct snd_emu8000 *emu = rec->emu;
 517         unsigned short __user *buf = src;
 518
 519         snd_emu8000_write_wait(emu, 1);
 520         EMU8000_SMALW_WRITE(emu, pos + rec->loop_start[0]);
 521         if (rec->voices > 1)
 522                 EMU8000_SMARW_WRITE(emu, pos + rec->loop_start[1]);
 523
 524         while (count-- > 0) {
 525                 unsigned short sval;
 526                 CHECK_SCHEDULER();
 527                 get_user(sval, buf);
 528                 EMU8000_SMLD_WRITE(emu, sval);
 529                 buf++;
 530                 if (rec->voices > 1) {
 531                         CHECK_SCHEDULER();
 532                         get_user(sval, buf);
 533                         EMU8000_SMRD_WRITE(emu, sval);
 534                         buf++;
 535                 }
 536         }
 537         return 0;
 538 }
 539
 540 static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
 541                              int voice,
 542                              snd_pcm_uframes_t pos,
 543                              snd_pcm_uframes_t count)
 544 {
 545         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 546         struct snd_emu8000 *emu = rec->emu;
 547
 548         snd_emu8000_write_wait(emu, 1);
 549         EMU8000_SMALW_WRITE(emu, rec->loop_start[0] + pos);
 550         if (rec->voices > 1)
 551                 EMU8000_SMARW_WRITE(emu, rec->loop_start[1] + pos);
 552         while (count-- > 0) {
 553                 CHECK_SCHEDULER();
 554                 EMU8000_SMLD_WRITE(emu, 0);
 555                 if (rec->voices > 1) {
 556                         CHECK_SCHEDULER();
 557                         EMU8000_SMRD_WRITE(emu, 0);
 558                 }
 559         }
 560         return 0;
 561 }
 562 #endif
 563
 564
 565 /*
 566  * allocate a memory block
 567  */
 568 static int emu8k_pcm_hw_params(struct snd_pcm_substream *subs,
 569                                struct snd_pcm_hw_params *hw_params)
 570 {
 571         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 572
 573         if (rec->block) {
 574                 /* reallocation - release the old block */
 575                 snd_util_mem_free(rec->emu->memhdr, rec->block);
 576                 rec->block = NULL;
 577         }
 578
 579         rec->allocated_bytes = params_buffer_bytes(hw_params) + LOOP_BLANK_SIZE * 4;
 580         rec->block = snd_util_mem_alloc(rec->emu->memhdr, rec->allocated_bytes);
 581         if (! rec->block)
 582                 return -ENOMEM;
 583         rec->offset = EMU8000_DRAM_OFFSET + (rec->block->offset >> 1); /* in word */
 584         /* at least dma_bytes must be set for non-interleaved mode */
 585         subs->dma_buffer.bytes = params_buffer_bytes(hw_params);
 586
 587         return 0;
 588 }
 589
 590 /*
 591  * free the memory block
 592  */
 593 static int emu8k_pcm_hw_free(struct snd_pcm_substream *subs)
 594 {
 595         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 596
 597         if (rec->block) {
 598                 int ch;
 599                 for (ch = 0; ch < rec->voices; ch++)
 600                         stop_voice(rec, ch); // to be sure
 601                 if (rec->dram_opened)
 602                         emu8k_close_dram(rec->emu);
 603                 snd_util_mem_free(rec->emu->memhdr, rec->block);
 604                 rec->block = NULL;
 605         }
 606         return 0;
 607 }
 608
 609 /*
 610  */
 611 static int emu8k_pcm_prepare(struct snd_pcm_substream *subs)
 612 {
 613         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 614
 615         rec->pitch = 0xe000 + calc_rate_offset(subs->runtime->rate);
 616         rec->last_ptr = 0;
 617         rec->period_pos = 0;
 618
 619         rec->buf_size = subs->runtime->buffer_size;
 620         rec->period_size = subs->runtime->period_size;
 621         rec->voices = subs->runtime->channels;
 622         rec->loop_start[0] = rec->offset + LOOP_BLANK_SIZE;
 623         if (rec->voices > 1)
 624                 rec->loop_start[1] = rec->loop_start[0] + rec->buf_size + LOOP_BLANK_SIZE;
 625         if (rec->voices > 1) {
 626                 rec->panning[0] = 0xff;
 627                 rec->panning[1] = 0x00;
 628         } else
 629                 rec->panning[0] = 0x80;
 630
 631         if (! rec->dram_opened) {
 632                 int err, i, ch;
 633
 634                 snd_emux_terminate_all(rec->emu->emu);
 635                 if ((err = emu8k_open_dram_for_pcm(rec->emu, rec->voices)) != 0)
 636                         return err;
 637                 rec->dram_opened = 1;
 638
 639                 /* clear loop blanks */
 640                 snd_emu8000_write_wait(rec->emu, 0);
 641                 EMU8000_SMALW_WRITE(rec->emu, rec->offset);
 642                 for (i = 0; i < LOOP_BLANK_SIZE; i++)
 643                         EMU8000_SMLD_WRITE(rec->emu, 0);
 644                 for (ch = 0; ch < rec->voices; ch++) {
 645                         EMU8000_SMALW_WRITE(rec->emu, rec->loop_start[ch] + rec->buf_size);
 646                         for (i = 0; i < LOOP_BLANK_SIZE; i++)
 647                                 EMU8000_SMLD_WRITE(rec->emu, 0);
 648                 }
 649         }
 650
 651         setup_voice(rec, 0);
 652         if (rec->voices > 1)
 653                 setup_voice(rec, 1);
 654         return 0;
 655 }
 656
 657 static snd_pcm_uframes_t emu8k_pcm_pointer(struct snd_pcm_substream *subs)
 658 {
 659         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 660         if (rec->running)
 661                 return emu8k_get_curpos(rec, 0);
 662         return 0;
 663 }
 664
 665
 666 static struct snd_pcm_ops emu8k_pcm_ops = {
 667         .open =         emu8k_pcm_open,
 668         .close =        emu8k_pcm_close,
 669         .ioctl =        snd_pcm_lib_ioctl,
 670         .hw_params =    emu8k_pcm_hw_params,
 671         .hw_free =      emu8k_pcm_hw_free,
 672         .prepare =      emu8k_pcm_prepare,
 673         .trigger =      emu8k_pcm_trigger,
 674         .pointer =      emu8k_pcm_pointer,
 675         .copy =         emu8k_pcm_copy,
 676         .silence =      emu8k_pcm_silence,
 677 };
 678
 679
 680 static void snd_emu8000_pcm_free(struct snd_pcm *pcm)
 681 {
 682         struct snd_emu8000 *emu = pcm->private_data;
 683         emu->pcm = NULL;
 684 }
 685
 686 int snd_emu8000_pcm_new(struct snd_card *card, struct snd_emu8000 *emu, int index)
 687 {
 688         struct snd_pcm *pcm;
 689         int err;
 690
 691         if ((err = snd_pcm_new(card, "Emu8000 PCM", index, 1, 0, &pcm)) < 0)
 692                 return err;
 693         pcm->private_data = emu;
 694         pcm->private_free = snd_emu8000_pcm_free;
 695         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &emu8k_pcm_ops);
 696         emu->pcm = pcm;
 697
 698         snd_device_register(card, pcm);
 699
 700         return 0;
 701 }