root/sound/isa/sb/emu8000_pcm.c

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DEFINITIONS

This source file includes following definitions.
  1. emu8k_open_dram_for_pcm
  2. snd_emu8000_write_wait
  3. emu8k_close_dram
  4. calc_rate_offset
  5. emu8k_get_curpos
  6. emu8k_pcm_timer_func
  7. emu8k_pcm_open
  8. emu8k_pcm_close
  9. calc_pitch_target
  10. setup_voice
  11. start_voice
  12. stop_voice
  13. emu8k_pcm_trigger
  14. emu8k_pcm_copy
  15. emu8k_pcm_copy_kernel
  16. emu8k_pcm_silence
  17. emu8k_pcm_copy
  18. emu8k_pcm_copy_kernel
  19. emu8k_pcm_silence
  20. emu8k_pcm_hw_params
  21. emu8k_pcm_hw_free
  22. emu8k_pcm_prepare
  23. emu8k_pcm_pointer
  24. snd_emu8000_pcm_free
  25. snd_emu8000_pcm_new
   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 
  39 struct 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  */
  67 static int
  68 emu8k_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  */
 103 static void
 104 snd_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  */
 118 static void
 119 emu8k_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 
 138 static 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 
 147 static 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  */
 171 static 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  */
 183 static 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  */
 216 static 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 
 244 static 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  */
 255 static 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  */
 269 static 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  */
 322 static 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  */
 357 static 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 
 373 static 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() \
 406 do { \
 407         cond_resched();\
 408         if (signal_pending(current))\
 409                 return -EAGAIN;\
 410 } while (0)
 411 
 412 enum {
 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 = (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 */
 451 static 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 
 464 static 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 */
 478 static 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 = (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  */
 519 static 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 
 532 static 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 
 545 static 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  */
 562 static 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  */
 587 static 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  */
 605 static 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                 if ((err = emu8k_open_dram_for_pcm(rec->emu, rec->voices)) != 0)
 630                         return err;
 631                 rec->dram_opened = 1;
 632 
 633                 /* clear loop blanks */
 634                 snd_emu8000_write_wait(rec->emu, 0);
 635                 EMU8000_SMALW_WRITE(rec->emu, rec->offset);
 636                 for (i = 0; i < LOOP_BLANK_SIZE; i++)
 637                         EMU8000_SMLD_WRITE(rec->emu, 0);
 638                 for (ch = 0; ch < rec->voices; ch++) {
 639                         EMU8000_SMALW_WRITE(rec->emu, rec->loop_start[ch] + rec->buf_size);
 640                         for (i = 0; i < LOOP_BLANK_SIZE; i++)
 641                                 EMU8000_SMLD_WRITE(rec->emu, 0);
 642                 }
 643         }
 644 
 645         setup_voice(rec, 0);
 646         if (rec->voices > 1)
 647                 setup_voice(rec, 1);
 648         return 0;
 649 }
 650 
 651 static snd_pcm_uframes_t emu8k_pcm_pointer(struct snd_pcm_substream *subs)
 652 {
 653         struct snd_emu8k_pcm *rec = subs->runtime->private_data;
 654         if (rec->running)
 655                 return emu8k_get_curpos(rec, 0);
 656         return 0;
 657 }
 658 
 659 
 660 static const struct snd_pcm_ops emu8k_pcm_ops = {
 661         .open =         emu8k_pcm_open,
 662         .close =        emu8k_pcm_close,
 663         .ioctl =        snd_pcm_lib_ioctl,
 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 
 675 static void snd_emu8000_pcm_free(struct snd_pcm *pcm)
 676 {
 677         struct snd_emu8000 *emu = pcm->private_data;
 678         emu->pcm = NULL;
 679 }
 680 
 681 int 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         if ((err = snd_pcm_new(card, "Emu8000 PCM", index, 1, 0, &pcm)) < 0)
 687                 return err;
 688         pcm->private_data = emu;
 689         pcm->private_free = snd_emu8000_pcm_free;
 690         snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &emu8k_pcm_ops);
 691         emu->pcm = pcm;
 692 
 693         snd_device_register(card, pcm);
 694 
 695         return 0;
 696 }
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