xref: /openbmc/linux/sound/isa/sb/emu8000_pcm.c (revision 4f3db074)
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 	mod_timer(&rec->timer, jiffies + 1);
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 	setup_timer(&rec->timer, emu8k_pcm_timer_func, (unsigned long)rec);
243 
244 	runtime->hw = emu8k_pcm_hw;
245 	runtime->hw.buffer_bytes_max = emu->mem_size - LOOP_BLANK_SIZE * 3;
246 	runtime->hw.period_bytes_max = runtime->hw.buffer_bytes_max / 2;
247 
248 	/* use timer to update periods.. (specified in msec) */
249 	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
250 				     (1000000 + HZ - 1) / HZ, UINT_MAX);
251 
252 	return 0;
253 }
254 
255 static int emu8k_pcm_close(struct snd_pcm_substream *subs)
256 {
257 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
258 	kfree(rec);
259 	subs->runtime->private_data = NULL;
260 	return 0;
261 }
262 
263 /*
264  * calculate pitch target
265  */
266 static int calc_pitch_target(int pitch)
267 {
268 	int ptarget = 1 << (pitch >> 12);
269 	if (pitch & 0x800) ptarget += (ptarget * 0x102e) / 0x2710;
270 	if (pitch & 0x400) ptarget += (ptarget * 0x764) / 0x2710;
271 	if (pitch & 0x200) ptarget += (ptarget * 0x389) / 0x2710;
272 	ptarget += (ptarget >> 1);
273 	if (ptarget > 0xffff) ptarget = 0xffff;
274 	return ptarget;
275 }
276 
277 /*
278  * set up the voice
279  */
280 static void setup_voice(struct snd_emu8k_pcm *rec, int ch)
281 {
282 	struct snd_emu8000 *hw = rec->emu;
283 	unsigned int temp;
284 
285 	/* channel to be silent and idle */
286 	EMU8000_DCYSUSV_WRITE(hw, ch, 0x0080);
287 	EMU8000_VTFT_WRITE(hw, ch, 0x0000FFFF);
288 	EMU8000_CVCF_WRITE(hw, ch, 0x0000FFFF);
289 	EMU8000_PTRX_WRITE(hw, ch, 0);
290 	EMU8000_CPF_WRITE(hw, ch, 0);
291 
292 	/* pitch offset */
293 	EMU8000_IP_WRITE(hw, ch, rec->pitch);
294 	/* set envelope parameters */
295 	EMU8000_ENVVAL_WRITE(hw, ch, 0x8000);
296 	EMU8000_ATKHLD_WRITE(hw, ch, 0x7f7f);
297 	EMU8000_DCYSUS_WRITE(hw, ch, 0x7f7f);
298 	EMU8000_ENVVOL_WRITE(hw, ch, 0x8000);
299 	EMU8000_ATKHLDV_WRITE(hw, ch, 0x7f7f);
300 	/* decay/sustain parameter for volume envelope is used
301 	   for triggerg the voice */
302 	/* modulation envelope heights */
303 	EMU8000_PEFE_WRITE(hw, ch, 0x0);
304 	/* lfo1/2 delay */
305 	EMU8000_LFO1VAL_WRITE(hw, ch, 0x8000);
306 	EMU8000_LFO2VAL_WRITE(hw, ch, 0x8000);
307 	/* lfo1 pitch & cutoff shift */
308 	EMU8000_FMMOD_WRITE(hw, ch, 0);
309 	/* lfo1 volume & freq */
310 	EMU8000_TREMFRQ_WRITE(hw, ch, 0);
311 	/* lfo2 pitch & freq */
312 	EMU8000_FM2FRQ2_WRITE(hw, ch, 0);
313 	/* pan & loop start */
314 	temp = rec->panning[ch];
315 	temp = (temp <<24) | ((unsigned int)rec->loop_start[ch] - 1);
316 	EMU8000_PSST_WRITE(hw, ch, temp);
317 	/* chorus & loop end (chorus 8bit, MSB) */
318 	temp = 0; // chorus
319 	temp = (temp << 24) | ((unsigned int)rec->loop_start[ch] + rec->buf_size - 1);
320 	EMU8000_CSL_WRITE(hw, ch, temp);
321 	/* Q & current address (Q 4bit value, MSB) */
322 	temp = 0; // filterQ
323 	temp = (temp << 28) | ((unsigned int)rec->loop_start[ch] - 1);
324 	EMU8000_CCCA_WRITE(hw, ch, temp);
325 	/* clear unknown registers */
326 	EMU8000_00A0_WRITE(hw, ch, 0);
327 	EMU8000_0080_WRITE(hw, ch, 0);
328 }
329 
330 /*
331  * trigger the voice
332  */
333 static void start_voice(struct snd_emu8k_pcm *rec, int ch)
334 {
335 	unsigned long flags;
336 	struct snd_emu8000 *hw = rec->emu;
337 	unsigned int temp, aux;
338 	int pt = calc_pitch_target(rec->pitch);
339 
340 	/* cutoff and volume */
341 	EMU8000_IFATN_WRITE(hw, ch, 0xff00);
342 	EMU8000_VTFT_WRITE(hw, ch, 0xffff);
343 	EMU8000_CVCF_WRITE(hw, ch, 0xffff);
344 	/* trigger envelope */
345 	EMU8000_DCYSUSV_WRITE(hw, ch, 0x7f7f);
346 	/* set reverb and pitch target */
347 	temp = 0; // reverb
348 	if (rec->panning[ch] == 0)
349 		aux = 0xff;
350 	else
351 		aux = (-rec->panning[ch]) & 0xff;
352 	temp = (temp << 8) | (pt << 16) | aux;
353 	EMU8000_PTRX_WRITE(hw, ch, temp);
354 	EMU8000_CPF_WRITE(hw, ch, pt << 16);
355 
356 	/* start timer */
357 	spin_lock_irqsave(&rec->timer_lock, flags);
358 	if (! rec->timer_running) {
359 		mod_timer(&rec->timer, jiffies + 1);
360 		rec->timer_running = 1;
361 	}
362 	spin_unlock_irqrestore(&rec->timer_lock, flags);
363 }
364 
365 /*
366  * stop the voice immediately
367  */
368 static void stop_voice(struct snd_emu8k_pcm *rec, int ch)
369 {
370 	unsigned long flags;
371 	struct snd_emu8000 *hw = rec->emu;
372 
373 	EMU8000_DCYSUSV_WRITE(hw, ch, 0x807F);
374 
375 	/* stop timer */
376 	spin_lock_irqsave(&rec->timer_lock, flags);
377 	if (rec->timer_running) {
378 		del_timer(&rec->timer);
379 		rec->timer_running = 0;
380 	}
381 	spin_unlock_irqrestore(&rec->timer_lock, flags);
382 }
383 
384 static int emu8k_pcm_trigger(struct snd_pcm_substream *subs, int cmd)
385 {
386 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
387 	int ch;
388 
389 	switch (cmd) {
390 	case SNDRV_PCM_TRIGGER_START:
391 		for (ch = 0; ch < rec->voices; ch++)
392 			start_voice(rec, ch);
393 		rec->running = 1;
394 		break;
395 	case SNDRV_PCM_TRIGGER_STOP:
396 		rec->running = 0;
397 		for (ch = 0; ch < rec->voices; ch++)
398 			stop_voice(rec, ch);
399 		break;
400 	default:
401 		return -EINVAL;
402 	}
403 	return 0;
404 }
405 
406 
407 /*
408  * copy / silence ops
409  */
410 
411 /*
412  * this macro should be inserted in the copy/silence loops
413  * to reduce the latency.  without this, the system will hang up
414  * during the whole loop.
415  */
416 #define CHECK_SCHEDULER() \
417 do { \
418 	cond_resched();\
419 	if (signal_pending(current))\
420 		return -EAGAIN;\
421 } while (0)
422 
423 
424 #ifdef USE_NONINTERLEAVE
425 /* copy one channel block */
426 static int emu8k_transfer_block(struct snd_emu8000 *emu, int offset, unsigned short *buf, int count)
427 {
428 	EMU8000_SMALW_WRITE(emu, offset);
429 	while (count > 0) {
430 		unsigned short sval;
431 		CHECK_SCHEDULER();
432 		if (get_user(sval, buf))
433 			return -EFAULT;
434 		EMU8000_SMLD_WRITE(emu, sval);
435 		buf++;
436 		count--;
437 	}
438 	return 0;
439 }
440 
441 static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
442 			  int voice,
443 			  snd_pcm_uframes_t pos,
444 			  void *src,
445 			  snd_pcm_uframes_t count)
446 {
447 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
448 	struct snd_emu8000 *emu = rec->emu;
449 
450 	snd_emu8000_write_wait(emu, 1);
451 	if (voice == -1) {
452 		unsigned short *buf = src;
453 		int i, err;
454 		count /= rec->voices;
455 		for (i = 0; i < rec->voices; i++) {
456 			err = emu8k_transfer_block(emu, pos + rec->loop_start[i], buf, count);
457 			if (err < 0)
458 				return err;
459 			buf += count;
460 		}
461 		return 0;
462 	} else {
463 		return emu8k_transfer_block(emu, pos + rec->loop_start[voice], src, count);
464 	}
465 }
466 
467 /* make a channel block silence */
468 static int emu8k_silence_block(struct snd_emu8000 *emu, int offset, int count)
469 {
470 	EMU8000_SMALW_WRITE(emu, offset);
471 	while (count > 0) {
472 		CHECK_SCHEDULER();
473 		EMU8000_SMLD_WRITE(emu, 0);
474 		count--;
475 	}
476 	return 0;
477 }
478 
479 static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
480 			     int voice,
481 			     snd_pcm_uframes_t pos,
482 			     snd_pcm_uframes_t count)
483 {
484 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
485 	struct snd_emu8000 *emu = rec->emu;
486 
487 	snd_emu8000_write_wait(emu, 1);
488 	if (voice == -1 && rec->voices == 1)
489 		voice = 0;
490 	if (voice == -1) {
491 		int err;
492 		err = emu8k_silence_block(emu, pos + rec->loop_start[0], count / 2);
493 		if (err < 0)
494 			return err;
495 		return emu8k_silence_block(emu, pos + rec->loop_start[1], count / 2);
496 	} else {
497 		return emu8k_silence_block(emu, pos + rec->loop_start[voice], count);
498 	}
499 }
500 
501 #else /* interleave */
502 
503 /*
504  * copy the interleaved data can be done easily by using
505  * DMA "left" and "right" channels on emu8k engine.
506  */
507 static int emu8k_pcm_copy(struct snd_pcm_substream *subs,
508 			  int voice,
509 			  snd_pcm_uframes_t pos,
510 			  void __user *src,
511 			  snd_pcm_uframes_t count)
512 {
513 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
514 	struct snd_emu8000 *emu = rec->emu;
515 	unsigned short __user *buf = src;
516 
517 	snd_emu8000_write_wait(emu, 1);
518 	EMU8000_SMALW_WRITE(emu, pos + rec->loop_start[0]);
519 	if (rec->voices > 1)
520 		EMU8000_SMARW_WRITE(emu, pos + rec->loop_start[1]);
521 
522 	while (count-- > 0) {
523 		unsigned short sval;
524 		CHECK_SCHEDULER();
525 		if (get_user(sval, buf))
526 			return -EFAULT;
527 		EMU8000_SMLD_WRITE(emu, sval);
528 		buf++;
529 		if (rec->voices > 1) {
530 			CHECK_SCHEDULER();
531 			if (get_user(sval, buf))
532 				return -EFAULT;
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 }
702