xref: /openbmc/linux/sound/isa/sb/emu8000_pcm.c (revision 63dc02bd)
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 <linux/slab.h>
24 #include <sound/initval.h>
25 #include <sound/pcm.h>
26 
27 /*
28  * define the following if you want to use this pcm with non-interleaved mode
29  */
30 /* #define USE_NONINTERLEAVE */
31 
32 /* NOTE: for using the non-interleaved mode with alsa-lib, you have to set
33  * mmap_emulation flag to 1 in your .asoundrc, such like
34  *
35  *	pcm.emu8k {
36  *		type plug
37  *		slave.pcm {
38  *			type hw
39  *			card 0
40  *			device 1
41  *			mmap_emulation 1
42  *		}
43  *	}
44  *
45  * besides, for the time being, the non-interleaved mode doesn't work well on
46  * alsa-lib...
47  */
48 
49 
50 struct snd_emu8k_pcm {
51 	struct snd_emu8000 *emu;
52 	struct snd_pcm_substream *substream;
53 
54 	unsigned int allocated_bytes;
55 	struct snd_util_memblk *block;
56 	unsigned int offset;
57 	unsigned int buf_size;
58 	unsigned int period_size;
59 	unsigned int loop_start[2];
60 	unsigned int pitch;
61 	int panning[2];
62 	int last_ptr;
63 	int period_pos;
64 	int voices;
65 	unsigned int dram_opened: 1;
66 	unsigned int running: 1;
67 	unsigned int timer_running: 1;
68 	struct timer_list timer;
69 	spinlock_t timer_lock;
70 };
71 
72 #define LOOP_BLANK_SIZE		8
73 
74 
75 /*
76  * open up channels for the simultaneous data transfer and playback
77  */
78 static int
79 emu8k_open_dram_for_pcm(struct snd_emu8000 *emu, int channels)
80 {
81 	int i;
82 
83 	/* reserve up to 2 voices for playback */
84 	snd_emux_lock_voice(emu->emu, 0);
85 	if (channels > 1)
86 		snd_emux_lock_voice(emu->emu, 1);
87 
88 	/* reserve 28 voices for loading */
89 	for (i = channels + 1; i < EMU8000_DRAM_VOICES; i++) {
90 		unsigned int mode = EMU8000_RAM_WRITE;
91 		snd_emux_lock_voice(emu->emu, i);
92 #ifndef USE_NONINTERLEAVE
93 		if (channels > 1 && (i & 1) != 0)
94 			mode |= EMU8000_RAM_RIGHT;
95 #endif
96 		snd_emu8000_dma_chan(emu, i, mode);
97 	}
98 
99 	/* assign voice 31 and 32 to ROM */
100 	EMU8000_VTFT_WRITE(emu, 30, 0);
101 	EMU8000_PSST_WRITE(emu, 30, 0x1d8);
102 	EMU8000_CSL_WRITE(emu, 30, 0x1e0);
103 	EMU8000_CCCA_WRITE(emu, 30, 0x1d8);
104 	EMU8000_VTFT_WRITE(emu, 31, 0);
105 	EMU8000_PSST_WRITE(emu, 31, 0x1d8);
106 	EMU8000_CSL_WRITE(emu, 31, 0x1e0);
107 	EMU8000_CCCA_WRITE(emu, 31, 0x1d8);
108 
109 	return 0;
110 }
111 
112 /*
113  */
114 static void
115 snd_emu8000_write_wait(struct snd_emu8000 *emu, int can_schedule)
116 {
117 	while ((EMU8000_SMALW_READ(emu) & 0x80000000) != 0) {
118 		if (can_schedule) {
119 			schedule_timeout_interruptible(1);
120 			if (signal_pending(current))
121 				break;
122 		}
123 	}
124 }
125 
126 /*
127  * close all channels
128  */
129 static void
130 emu8k_close_dram(struct snd_emu8000 *emu)
131 {
132 	int i;
133 
134 	for (i = 0; i < 2; i++)
135 		snd_emux_unlock_voice(emu->emu, i);
136 	for (; i < EMU8000_DRAM_VOICES; i++) {
137 		snd_emu8000_dma_chan(emu, i, EMU8000_RAM_CLOSE);
138 		snd_emux_unlock_voice(emu->emu, i);
139 	}
140 }
141 
142 /*
143  * convert Hz to AWE32 rate offset (see emux/soundfont.c)
144  */
145 
146 #define OFFSET_SAMPLERATE	1011119		/* base = 44100 */
147 #define SAMPLERATE_RATIO	4096
148 
149 static int calc_rate_offset(int hz)
150 {
151 	return snd_sf_linear_to_log(hz, OFFSET_SAMPLERATE, SAMPLERATE_RATIO);
152 }
153 
154 
155 /*
156  */
157 
158 static struct snd_pcm_hardware emu8k_pcm_hw = {
159 #ifdef USE_NONINTERLEAVE
160 	.info =			SNDRV_PCM_INFO_NONINTERLEAVED,
161 #else
162 	.info =			SNDRV_PCM_INFO_INTERLEAVED,
163 #endif
164 	.formats =		SNDRV_PCM_FMTBIT_S16_LE,
165 	.rates =		SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
166 	.rate_min =		4000,
167 	.rate_max =		48000,
168 	.channels_min =		1,
169 	.channels_max =		2,
170 	.buffer_bytes_max =	(128*1024),
171 	.period_bytes_min =	1024,
172 	.period_bytes_max =	(128*1024),
173 	.periods_min =		2,
174 	.periods_max =		1024,
175 	.fifo_size =		0,
176 
177 };
178 
179 /*
180  * get the current position at the given channel from CCCA register
181  */
182 static inline int emu8k_get_curpos(struct snd_emu8k_pcm *rec, int ch)
183 {
184 	int val = EMU8000_CCCA_READ(rec->emu, ch) & 0xfffffff;
185 	val -= rec->loop_start[ch] - 1;
186 	return val;
187 }
188 
189 
190 /*
191  * timer interrupt handler
192  * check the current position and update the period if necessary.
193  */
194 static void emu8k_pcm_timer_func(unsigned long data)
195 {
196 	struct snd_emu8k_pcm *rec = (struct snd_emu8k_pcm *)data;
197 	int ptr, delta;
198 
199 	spin_lock(&rec->timer_lock);
200 	/* update the current pointer */
201 	ptr = emu8k_get_curpos(rec, 0);
202 	if (ptr < rec->last_ptr)
203 		delta = ptr + rec->buf_size - rec->last_ptr;
204 	else
205 		delta = ptr - rec->last_ptr;
206 	rec->period_pos += delta;
207 	rec->last_ptr = ptr;
208 
209 	/* reprogram timer */
210 	rec->timer.expires = jiffies + 1;
211 	add_timer(&rec->timer);
212 
213 	/* update period */
214 	if (rec->period_pos >= (int)rec->period_size) {
215 		rec->period_pos %= rec->period_size;
216 		spin_unlock(&rec->timer_lock);
217 		snd_pcm_period_elapsed(rec->substream);
218 		return;
219 	}
220 	spin_unlock(&rec->timer_lock);
221 }
222 
223 
224 /*
225  * open pcm
226  * creating an instance here
227  */
228 static int emu8k_pcm_open(struct snd_pcm_substream *subs)
229 {
230 	struct snd_emu8000 *emu = snd_pcm_substream_chip(subs);
231 	struct snd_emu8k_pcm *rec;
232 	struct snd_pcm_runtime *runtime = subs->runtime;
233 
234 	rec = kzalloc(sizeof(*rec), GFP_KERNEL);
235 	if (! rec)
236 		return -ENOMEM;
237 
238 	rec->emu = emu;
239 	rec->substream = subs;
240 	runtime->private_data = rec;
241 
242 	spin_lock_init(&rec->timer_lock);
243 	init_timer(&rec->timer);
244 	rec->timer.function = emu8k_pcm_timer_func;
245 	rec->timer.data = (unsigned long)rec;
246 
247 	runtime->hw = emu8k_pcm_hw;
248 	runtime->hw.buffer_bytes_max = emu->mem_size - LOOP_BLANK_SIZE * 3;
249 	runtime->hw.period_bytes_max = runtime->hw.buffer_bytes_max / 2;
250 
251 	/* use timer to update periods.. (specified in msec) */
252 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
253 				     (1000000 + HZ - 1) / HZ, UINT_MAX);
254 
255 	return 0;
256 }
257 
258 static int emu8k_pcm_close(struct snd_pcm_substream *subs)
259 {
260 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
261 	kfree(rec);
262 	subs->runtime->private_data = NULL;
263 	return 0;
264 }
265 
266 /*
267  * calculate pitch target
268  */
269 static int calc_pitch_target(int pitch)
270 {
271 	int ptarget = 1 << (pitch >> 12);
272 	if (pitch & 0x800) ptarget += (ptarget * 0x102e) / 0x2710;
273 	if (pitch & 0x400) ptarget += (ptarget * 0x764) / 0x2710;
274 	if (pitch & 0x200) ptarget += (ptarget * 0x389) / 0x2710;
275 	ptarget += (ptarget >> 1);
276 	if (ptarget > 0xffff) ptarget = 0xffff;
277 	return ptarget;
278 }
279 
280 /*
281  * set up the voice
282  */
283 static void setup_voice(struct snd_emu8k_pcm *rec, int ch)
284 {
285 	struct snd_emu8000 *hw = rec->emu;
286 	unsigned int temp;
287 
288 	/* channel to be silent and idle */
289 	EMU8000_DCYSUSV_WRITE(hw, ch, 0x0080);
290 	EMU8000_VTFT_WRITE(hw, ch, 0x0000FFFF);
291 	EMU8000_CVCF_WRITE(hw, ch, 0x0000FFFF);
292 	EMU8000_PTRX_WRITE(hw, ch, 0);
293 	EMU8000_CPF_WRITE(hw, ch, 0);
294 
295 	/* pitch offset */
296 	EMU8000_IP_WRITE(hw, ch, rec->pitch);
297 	/* set envelope parameters */
298 	EMU8000_ENVVAL_WRITE(hw, ch, 0x8000);
299 	EMU8000_ATKHLD_WRITE(hw, ch, 0x7f7f);
300 	EMU8000_DCYSUS_WRITE(hw, ch, 0x7f7f);
301 	EMU8000_ENVVOL_WRITE(hw, ch, 0x8000);
302 	EMU8000_ATKHLDV_WRITE(hw, ch, 0x7f7f);
303 	/* decay/sustain parameter for volume envelope is used
304 	   for triggerg the voice */
305 	/* modulation envelope heights */
306 	EMU8000_PEFE_WRITE(hw, ch, 0x0);
307 	/* lfo1/2 delay */
308 	EMU8000_LFO1VAL_WRITE(hw, ch, 0x8000);
309 	EMU8000_LFO2VAL_WRITE(hw, ch, 0x8000);
310 	/* lfo1 pitch & cutoff shift */
311 	EMU8000_FMMOD_WRITE(hw, ch, 0);
312 	/* lfo1 volume & freq */
313 	EMU8000_TREMFRQ_WRITE(hw, ch, 0);
314 	/* lfo2 pitch & freq */
315 	EMU8000_FM2FRQ2_WRITE(hw, ch, 0);
316 	/* pan & loop start */
317 	temp = rec->panning[ch];
318 	temp = (temp <<24) | ((unsigned int)rec->loop_start[ch] - 1);
319 	EMU8000_PSST_WRITE(hw, ch, temp);
320 	/* chorus & loop end (chorus 8bit, MSB) */
321 	temp = 0; // chorus
322 	temp = (temp << 24) | ((unsigned int)rec->loop_start[ch] + rec->buf_size - 1);
323 	EMU8000_CSL_WRITE(hw, ch, temp);
324 	/* Q & current address (Q 4bit value, MSB) */
325 	temp = 0; // filterQ
326 	temp = (temp << 28) | ((unsigned int)rec->loop_start[ch] - 1);
327 	EMU8000_CCCA_WRITE(hw, ch, temp);
328 	/* clear unknown registers */
329 	EMU8000_00A0_WRITE(hw, ch, 0);
330 	EMU8000_0080_WRITE(hw, ch, 0);
331 }
332 
333 /*
334  * trigger the voice
335  */
336 static void start_voice(struct snd_emu8k_pcm *rec, int ch)
337 {
338 	unsigned long flags;
339 	struct snd_emu8000 *hw = rec->emu;
340 	unsigned int temp, aux;
341 	int pt = calc_pitch_target(rec->pitch);
342 
343 	/* cutoff and volume */
344 	EMU8000_IFATN_WRITE(hw, ch, 0xff00);
345 	EMU8000_VTFT_WRITE(hw, ch, 0xffff);
346 	EMU8000_CVCF_WRITE(hw, ch, 0xffff);
347 	/* trigger envelope */
348 	EMU8000_DCYSUSV_WRITE(hw, ch, 0x7f7f);
349 	/* set reverb and pitch target */
350 	temp = 0; // reverb
351 	if (rec->panning[ch] == 0)
352 		aux = 0xff;
353 	else
354 		aux = (-rec->panning[ch]) & 0xff;
355 	temp = (temp << 8) | (pt << 16) | aux;
356 	EMU8000_PTRX_WRITE(hw, ch, temp);
357 	EMU8000_CPF_WRITE(hw, ch, pt << 16);
358 
359 	/* start timer */
360 	spin_lock_irqsave(&rec->timer_lock, flags);
361 	if (! rec->timer_running) {
362 		rec->timer.expires = jiffies + 1;
363 		add_timer(&rec->timer);
364 		rec->timer_running = 1;
365 	}
366 	spin_unlock_irqrestore(&rec->timer_lock, flags);
367 }
368 
369 /*
370  * stop the voice immediately
371  */
372 static void stop_voice(struct snd_emu8k_pcm *rec, int ch)
373 {
374 	unsigned long flags;
375 	struct snd_emu8000 *hw = rec->emu;
376 
377 	EMU8000_DCYSUSV_WRITE(hw, ch, 0x807F);
378 
379 	/* stop timer */
380 	spin_lock_irqsave(&rec->timer_lock, flags);
381 	if (rec->timer_running) {
382 		del_timer(&rec->timer);
383 		rec->timer_running = 0;
384 	}
385 	spin_unlock_irqrestore(&rec->timer_lock, flags);
386 }
387 
388 static int emu8k_pcm_trigger(struct snd_pcm_substream *subs, int cmd)
389 {
390 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
391 	int ch;
392 
393 	switch (cmd) {
394 	case SNDRV_PCM_TRIGGER_START:
395 		for (ch = 0; ch < rec->voices; ch++)
396 			start_voice(rec, ch);
397 		rec->running = 1;
398 		break;
399 	case SNDRV_PCM_TRIGGER_STOP:
400 		rec->running = 0;
401 		for (ch = 0; ch < rec->voices; ch++)
402 			stop_voice(rec, ch);
403 		break;
404 	default:
405 		return -EINVAL;
406 	}
407 	return 0;
408 }
409 
410 
411 /*
412  * copy / silence ops
413  */
414 
415 /*
416  * this macro should be inserted in the copy/silence loops
417  * to reduce the latency.  without this, the system will hang up
418  * during the whole loop.
419  */
420 #define CHECK_SCHEDULER() \
421 do { \
422 	cond_resched();\
423 	if (signal_pending(current))\
424 		return -EAGAIN;\
425 } while (0)
426 
427 
428 #ifdef USE_NONINTERLEAVE
429 /* copy one channel block */
430 static int emu8k_transfer_block(struct snd_emu8000 *emu, int offset, unsigned short *buf, int count)
431 {
432 	EMU8000_SMALW_WRITE(emu, offset);
433 	while (count > 0) {
434 		unsigned short sval;
435 		CHECK_SCHEDULER();
436 		if (get_user(sval, buf))
437 			return -EFAULT;
438 		EMU8000_SMLD_WRITE(emu, sval);
439 		buf++;
440 		count--;
441 	}
442 	return 0;
443 }
444 
445 static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
446 			  int voice,
447 			  snd_pcm_uframes_t pos,
448 			  void *src,
449 			  snd_pcm_uframes_t count)
450 {
451 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
452 	struct snd_emu8000 *emu = rec->emu;
453 
454 	snd_emu8000_write_wait(emu, 1);
455 	if (voice == -1) {
456 		unsigned short *buf = src;
457 		int i, err;
458 		count /= rec->voices;
459 		for (i = 0; i < rec->voices; i++) {
460 			err = emu8k_transfer_block(emu, pos + rec->loop_start[i], buf, count);
461 			if (err < 0)
462 				return err;
463 			buf += count;
464 		}
465 		return 0;
466 	} else {
467 		return emu8k_transfer_block(emu, pos + rec->loop_start[voice], src, count);
468 	}
469 }
470 
471 /* make a channel block silence */
472 static int emu8k_silence_block(struct snd_emu8000 *emu, int offset, int count)
473 {
474 	EMU8000_SMALW_WRITE(emu, offset);
475 	while (count > 0) {
476 		CHECK_SCHEDULER();
477 		EMU8000_SMLD_WRITE(emu, 0);
478 		count--;
479 	}
480 	return 0;
481 }
482 
483 static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
484 			     int voice,
485 			     snd_pcm_uframes_t pos,
486 			     snd_pcm_uframes_t count)
487 {
488 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
489 	struct snd_emu8000 *emu = rec->emu;
490 
491 	snd_emu8000_write_wait(emu, 1);
492 	if (voice == -1 && rec->voices == 1)
493 		voice = 0;
494 	if (voice == -1) {
495 		int err;
496 		err = emu8k_silence_block(emu, pos + rec->loop_start[0], count / 2);
497 		if (err < 0)
498 			return err;
499 		return emu8k_silence_block(emu, pos + rec->loop_start[1], count / 2);
500 	} else {
501 		return emu8k_silence_block(emu, pos + rec->loop_start[voice], count);
502 	}
503 }
504 
505 #else /* interleave */
506 
507 /*
508  * copy the interleaved data can be done easily by using
509  * DMA "left" and "right" channels on emu8k engine.
510  */
511 static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
512 			  int voice,
513 			  snd_pcm_uframes_t pos,
514 			  void __user *src,
515 			  snd_pcm_uframes_t count)
516 {
517 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
518 	struct snd_emu8000 *emu = rec->emu;
519 	unsigned short __user *buf = src;
520 
521 	snd_emu8000_write_wait(emu, 1);
522 	EMU8000_SMALW_WRITE(emu, pos + rec->loop_start[0]);
523 	if (rec->voices > 1)
524 		EMU8000_SMARW_WRITE(emu, pos + rec->loop_start[1]);
525 
526 	while (count-- > 0) {
527 		unsigned short sval;
528 		CHECK_SCHEDULER();
529 		if (get_user(sval, buf))
530 			return -EFAULT;
531 		EMU8000_SMLD_WRITE(emu, sval);
532 		buf++;
533 		if (rec->voices > 1) {
534 			CHECK_SCHEDULER();
535 			if (get_user(sval, buf))
536 				return -EFAULT;
537 			EMU8000_SMRD_WRITE(emu, sval);
538 			buf++;
539 		}
540 	}
541 	return 0;
542 }
543 
544 static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
545 			     int voice,
546 			     snd_pcm_uframes_t pos,
547 			     snd_pcm_uframes_t count)
548 {
549 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
550 	struct snd_emu8000 *emu = rec->emu;
551 
552 	snd_emu8000_write_wait(emu, 1);
553 	EMU8000_SMALW_WRITE(emu, rec->loop_start[0] + pos);
554 	if (rec->voices > 1)
555 		EMU8000_SMARW_WRITE(emu, rec->loop_start[1] + pos);
556 	while (count-- > 0) {
557 		CHECK_SCHEDULER();
558 		EMU8000_SMLD_WRITE(emu, 0);
559 		if (rec->voices > 1) {
560 			CHECK_SCHEDULER();
561 			EMU8000_SMRD_WRITE(emu, 0);
562 		}
563 	}
564 	return 0;
565 }
566 #endif
567 
568 
569 /*
570  * allocate a memory block
571  */
572 static int emu8k_pcm_hw_params(struct snd_pcm_substream *subs,
573 			       struct snd_pcm_hw_params *hw_params)
574 {
575 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
576 
577 	if (rec->block) {
578 		/* reallocation - release the old block */
579 		snd_util_mem_free(rec->emu->memhdr, rec->block);
580 		rec->block = NULL;
581 	}
582 
583 	rec->allocated_bytes = params_buffer_bytes(hw_params) + LOOP_BLANK_SIZE * 4;
584 	rec->block = snd_util_mem_alloc(rec->emu->memhdr, rec->allocated_bytes);
585 	if (! rec->block)
586 		return -ENOMEM;
587 	rec->offset = EMU8000_DRAM_OFFSET + (rec->block->offset >> 1); /* in word */
588 	/* at least dma_bytes must be set for non-interleaved mode */
589 	subs->dma_buffer.bytes = params_buffer_bytes(hw_params);
590 
591 	return 0;
592 }
593 
594 /*
595  * free the memory block
596  */
597 static int emu8k_pcm_hw_free(struct snd_pcm_substream *subs)
598 {
599 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
600 
601 	if (rec->block) {
602 		int ch;
603 		for (ch = 0; ch < rec->voices; ch++)
604 			stop_voice(rec, ch); // to be sure
605 		if (rec->dram_opened)
606 			emu8k_close_dram(rec->emu);
607 		snd_util_mem_free(rec->emu->memhdr, rec->block);
608 		rec->block = NULL;
609 	}
610 	return 0;
611 }
612 
613 /*
614  */
615 static int emu8k_pcm_prepare(struct snd_pcm_substream *subs)
616 {
617 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
618 
619 	rec->pitch = 0xe000 + calc_rate_offset(subs->runtime->rate);
620 	rec->last_ptr = 0;
621 	rec->period_pos = 0;
622 
623 	rec->buf_size = subs->runtime->buffer_size;
624 	rec->period_size = subs->runtime->period_size;
625 	rec->voices = subs->runtime->channels;
626 	rec->loop_start[0] = rec->offset + LOOP_BLANK_SIZE;
627 	if (rec->voices > 1)
628 		rec->loop_start[1] = rec->loop_start[0] + rec->buf_size + LOOP_BLANK_SIZE;
629 	if (rec->voices > 1) {
630 		rec->panning[0] = 0xff;
631 		rec->panning[1] = 0x00;
632 	} else
633 		rec->panning[0] = 0x80;
634 
635 	if (! rec->dram_opened) {
636 		int err, i, ch;
637 
638 		snd_emux_terminate_all(rec->emu->emu);
639 		if ((err = emu8k_open_dram_for_pcm(rec->emu, rec->voices)) != 0)
640 			return err;
641 		rec->dram_opened = 1;
642 
643 		/* clear loop blanks */
644 		snd_emu8000_write_wait(rec->emu, 0);
645 		EMU8000_SMALW_WRITE(rec->emu, rec->offset);
646 		for (i = 0; i < LOOP_BLANK_SIZE; i++)
647 			EMU8000_SMLD_WRITE(rec->emu, 0);
648 		for (ch = 0; ch < rec->voices; ch++) {
649 			EMU8000_SMALW_WRITE(rec->emu, rec->loop_start[ch] + rec->buf_size);
650 			for (i = 0; i < LOOP_BLANK_SIZE; i++)
651 				EMU8000_SMLD_WRITE(rec->emu, 0);
652 		}
653 	}
654 
655 	setup_voice(rec, 0);
656 	if (rec->voices > 1)
657 		setup_voice(rec, 1);
658 	return 0;
659 }
660 
661 static snd_pcm_uframes_t emu8k_pcm_pointer(struct snd_pcm_substream *subs)
662 {
663 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
664 	if (rec->running)
665 		return emu8k_get_curpos(rec, 0);
666 	return 0;
667 }
668 
669 
670 static struct snd_pcm_ops emu8k_pcm_ops = {
671 	.open =		emu8k_pcm_open,
672 	.close =	emu8k_pcm_close,
673 	.ioctl =	snd_pcm_lib_ioctl,
674 	.hw_params =	emu8k_pcm_hw_params,
675 	.hw_free =	emu8k_pcm_hw_free,
676 	.prepare =	emu8k_pcm_prepare,
677 	.trigger =	emu8k_pcm_trigger,
678 	.pointer =	emu8k_pcm_pointer,
679 	.copy =		emu8k_pcm_copy,
680 	.silence =	emu8k_pcm_silence,
681 };
682 
683 
684 static void snd_emu8000_pcm_free(struct snd_pcm *pcm)
685 {
686 	struct snd_emu8000 *emu = pcm->private_data;
687 	emu->pcm = NULL;
688 }
689 
690 int snd_emu8000_pcm_new(struct snd_card *card, struct snd_emu8000 *emu, int index)
691 {
692 	struct snd_pcm *pcm;
693 	int err;
694 
695 	if ((err = snd_pcm_new(card, "Emu8000 PCM", index, 1, 0, &pcm)) < 0)
696 		return err;
697 	pcm->private_data = emu;
698 	pcm->private_free = snd_emu8000_pcm_free;
699 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &emu8k_pcm_ops);
700 	emu->pcm = pcm;
701 
702 	snd_device_register(card, pcm);
703 
704 	return 0;
705 }
706