xref: /openbmc/linux/sound/isa/sb/emu8000_pcm.c (revision aac5987a)
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 
23 #include <linux/sched/signal.h>
24 #include <linux/init.h>
25 #include <linux/slab.h>
26 #include <sound/initval.h>
27 #include <sound/pcm.h>
28 
29 /*
30  * define the following if you want to use this pcm with non-interleaved mode
31  */
32 /* #define USE_NONINTERLEAVE */
33 
34 /* NOTE: for using the non-interleaved mode with alsa-lib, you have to set
35  * mmap_emulation flag to 1 in your .asoundrc, such like
36  *
37  *	pcm.emu8k {
38  *		type plug
39  *		slave.pcm {
40  *			type hw
41  *			card 0
42  *			device 1
43  *			mmap_emulation 1
44  *		}
45  *	}
46  *
47  * besides, for the time being, the non-interleaved mode doesn't work well on
48  * alsa-lib...
49  */
50 
51 
52 struct snd_emu8k_pcm {
53 	struct snd_emu8000 *emu;
54 	struct snd_pcm_substream *substream;
55 
56 	unsigned int allocated_bytes;
57 	struct snd_util_memblk *block;
58 	unsigned int offset;
59 	unsigned int buf_size;
60 	unsigned int period_size;
61 	unsigned int loop_start[2];
62 	unsigned int pitch;
63 	int panning[2];
64 	int last_ptr;
65 	int period_pos;
66 	int voices;
67 	unsigned int dram_opened: 1;
68 	unsigned int running: 1;
69 	unsigned int timer_running: 1;
70 	struct timer_list timer;
71 	spinlock_t timer_lock;
72 };
73 
74 #define LOOP_BLANK_SIZE		8
75 
76 
77 /*
78  * open up channels for the simultaneous data transfer and playback
79  */
80 static int
81 emu8k_open_dram_for_pcm(struct snd_emu8000 *emu, int channels)
82 {
83 	int i;
84 
85 	/* reserve up to 2 voices for playback */
86 	snd_emux_lock_voice(emu->emu, 0);
87 	if (channels > 1)
88 		snd_emux_lock_voice(emu->emu, 1);
89 
90 	/* reserve 28 voices for loading */
91 	for (i = channels + 1; i < EMU8000_DRAM_VOICES; i++) {
92 		unsigned int mode = EMU8000_RAM_WRITE;
93 		snd_emux_lock_voice(emu->emu, i);
94 #ifndef USE_NONINTERLEAVE
95 		if (channels > 1 && (i & 1) != 0)
96 			mode |= EMU8000_RAM_RIGHT;
97 #endif
98 		snd_emu8000_dma_chan(emu, i, mode);
99 	}
100 
101 	/* assign voice 31 and 32 to ROM */
102 	EMU8000_VTFT_WRITE(emu, 30, 0);
103 	EMU8000_PSST_WRITE(emu, 30, 0x1d8);
104 	EMU8000_CSL_WRITE(emu, 30, 0x1e0);
105 	EMU8000_CCCA_WRITE(emu, 30, 0x1d8);
106 	EMU8000_VTFT_WRITE(emu, 31, 0);
107 	EMU8000_PSST_WRITE(emu, 31, 0x1d8);
108 	EMU8000_CSL_WRITE(emu, 31, 0x1e0);
109 	EMU8000_CCCA_WRITE(emu, 31, 0x1d8);
110 
111 	return 0;
112 }
113 
114 /*
115  */
116 static void
117 snd_emu8000_write_wait(struct snd_emu8000 *emu, int can_schedule)
118 {
119 	while ((EMU8000_SMALW_READ(emu) & 0x80000000) != 0) {
120 		if (can_schedule) {
121 			schedule_timeout_interruptible(1);
122 			if (signal_pending(current))
123 				break;
124 		}
125 	}
126 }
127 
128 /*
129  * close all channels
130  */
131 static void
132 emu8k_close_dram(struct snd_emu8000 *emu)
133 {
134 	int i;
135 
136 	for (i = 0; i < 2; i++)
137 		snd_emux_unlock_voice(emu->emu, i);
138 	for (; i < EMU8000_DRAM_VOICES; i++) {
139 		snd_emu8000_dma_chan(emu, i, EMU8000_RAM_CLOSE);
140 		snd_emux_unlock_voice(emu->emu, i);
141 	}
142 }
143 
144 /*
145  * convert Hz to AWE32 rate offset (see emux/soundfont.c)
146  */
147 
148 #define OFFSET_SAMPLERATE	1011119		/* base = 44100 */
149 #define SAMPLERATE_RATIO	4096
150 
151 static int calc_rate_offset(int hz)
152 {
153 	return snd_sf_linear_to_log(hz, OFFSET_SAMPLERATE, SAMPLERATE_RATIO);
154 }
155 
156 
157 /*
158  */
159 
160 static struct snd_pcm_hardware emu8k_pcm_hw = {
161 #ifdef USE_NONINTERLEAVE
162 	.info =			SNDRV_PCM_INFO_NONINTERLEAVED,
163 #else
164 	.info =			SNDRV_PCM_INFO_INTERLEAVED,
165 #endif
166 	.formats =		SNDRV_PCM_FMTBIT_S16_LE,
167 	.rates =		SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
168 	.rate_min =		4000,
169 	.rate_max =		48000,
170 	.channels_min =		1,
171 	.channels_max =		2,
172 	.buffer_bytes_max =	(128*1024),
173 	.period_bytes_min =	1024,
174 	.period_bytes_max =	(128*1024),
175 	.periods_min =		2,
176 	.periods_max =		1024,
177 	.fifo_size =		0,
178 
179 };
180 
181 /*
182  * get the current position at the given channel from CCCA register
183  */
184 static inline int emu8k_get_curpos(struct snd_emu8k_pcm *rec, int ch)
185 {
186 	int val = EMU8000_CCCA_READ(rec->emu, ch) & 0xfffffff;
187 	val -= rec->loop_start[ch] - 1;
188 	return val;
189 }
190 
191 
192 /*
193  * timer interrupt handler
194  * check the current position and update the period if necessary.
195  */
196 static void emu8k_pcm_timer_func(unsigned long data)
197 {
198 	struct snd_emu8k_pcm *rec = (struct snd_emu8k_pcm *)data;
199 	int ptr, delta;
200 
201 	spin_lock(&rec->timer_lock);
202 	/* update the current pointer */
203 	ptr = emu8k_get_curpos(rec, 0);
204 	if (ptr < rec->last_ptr)
205 		delta = ptr + rec->buf_size - rec->last_ptr;
206 	else
207 		delta = ptr - rec->last_ptr;
208 	rec->period_pos += delta;
209 	rec->last_ptr = ptr;
210 
211 	/* reprogram timer */
212 	mod_timer(&rec->timer, jiffies + 1);
213 
214 	/* update period */
215 	if (rec->period_pos >= (int)rec->period_size) {
216 		rec->period_pos %= rec->period_size;
217 		spin_unlock(&rec->timer_lock);
218 		snd_pcm_period_elapsed(rec->substream);
219 		return;
220 	}
221 	spin_unlock(&rec->timer_lock);
222 }
223 
224 
225 /*
226  * open pcm
227  * creating an instance here
228  */
229 static int emu8k_pcm_open(struct snd_pcm_substream *subs)
230 {
231 	struct snd_emu8000 *emu = snd_pcm_substream_chip(subs);
232 	struct snd_emu8k_pcm *rec;
233 	struct snd_pcm_runtime *runtime = subs->runtime;
234 
235 	rec = kzalloc(sizeof(*rec), GFP_KERNEL);
236 	if (! rec)
237 		return -ENOMEM;
238 
239 	rec->emu = emu;
240 	rec->substream = subs;
241 	runtime->private_data = rec;
242 
243 	spin_lock_init(&rec->timer_lock);
244 	setup_timer(&rec->timer, emu8k_pcm_timer_func, (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 		mod_timer(&rec->timer, jiffies + 1);
362 		rec->timer_running = 1;
363 	}
364 	spin_unlock_irqrestore(&rec->timer_lock, flags);
365 }
366 
367 /*
368  * stop the voice immediately
369  */
370 static void stop_voice(struct snd_emu8k_pcm *rec, int ch)
371 {
372 	unsigned long flags;
373 	struct snd_emu8000 *hw = rec->emu;
374 
375 	EMU8000_DCYSUSV_WRITE(hw, ch, 0x807F);
376 
377 	/* stop timer */
378 	spin_lock_irqsave(&rec->timer_lock, flags);
379 	if (rec->timer_running) {
380 		del_timer(&rec->timer);
381 		rec->timer_running = 0;
382 	}
383 	spin_unlock_irqrestore(&rec->timer_lock, flags);
384 }
385 
386 static int emu8k_pcm_trigger(struct snd_pcm_substream *subs, int cmd)
387 {
388 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
389 	int ch;
390 
391 	switch (cmd) {
392 	case SNDRV_PCM_TRIGGER_START:
393 		for (ch = 0; ch < rec->voices; ch++)
394 			start_voice(rec, ch);
395 		rec->running = 1;
396 		break;
397 	case SNDRV_PCM_TRIGGER_STOP:
398 		rec->running = 0;
399 		for (ch = 0; ch < rec->voices; ch++)
400 			stop_voice(rec, ch);
401 		break;
402 	default:
403 		return -EINVAL;
404 	}
405 	return 0;
406 }
407 
408 
409 /*
410  * copy / silence ops
411  */
412 
413 /*
414  * this macro should be inserted in the copy/silence loops
415  * to reduce the latency.  without this, the system will hang up
416  * during the whole loop.
417  */
418 #define CHECK_SCHEDULER() \
419 do { \
420 	cond_resched();\
421 	if (signal_pending(current))\
422 		return -EAGAIN;\
423 } while (0)
424 
425 
426 #ifdef USE_NONINTERLEAVE
427 /* copy one channel block */
428 static int emu8k_transfer_block(struct snd_emu8000 *emu, int offset, unsigned short *buf, int count)
429 {
430 	EMU8000_SMALW_WRITE(emu, offset);
431 	while (count > 0) {
432 		unsigned short sval;
433 		CHECK_SCHEDULER();
434 		if (get_user(sval, buf))
435 			return -EFAULT;
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 		if (get_user(sval, buf))
528 			return -EFAULT;
529 		EMU8000_SMLD_WRITE(emu, sval);
530 		buf++;
531 		if (rec->voices > 1) {
532 			CHECK_SCHEDULER();
533 			if (get_user(sval, buf))
534 				return -EFAULT;
535 			EMU8000_SMRD_WRITE(emu, sval);
536 			buf++;
537 		}
538 	}
539 	return 0;
540 }
541 
542 static int emu8k_pcm_silence(struct snd_pcm_substream *subs,
543 			     int voice,
544 			     snd_pcm_uframes_t pos,
545 			     snd_pcm_uframes_t count)
546 {
547 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
548 	struct snd_emu8000 *emu = rec->emu;
549 
550 	snd_emu8000_write_wait(emu, 1);
551 	EMU8000_SMALW_WRITE(emu, rec->loop_start[0] + pos);
552 	if (rec->voices > 1)
553 		EMU8000_SMARW_WRITE(emu, rec->loop_start[1] + pos);
554 	while (count-- > 0) {
555 		CHECK_SCHEDULER();
556 		EMU8000_SMLD_WRITE(emu, 0);
557 		if (rec->voices > 1) {
558 			CHECK_SCHEDULER();
559 			EMU8000_SMRD_WRITE(emu, 0);
560 		}
561 	}
562 	return 0;
563 }
564 #endif
565 
566 
567 /*
568  * allocate a memory block
569  */
570 static int emu8k_pcm_hw_params(struct snd_pcm_substream *subs,
571 			       struct snd_pcm_hw_params *hw_params)
572 {
573 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
574 
575 	if (rec->block) {
576 		/* reallocation - release the old block */
577 		snd_util_mem_free(rec->emu->memhdr, rec->block);
578 		rec->block = NULL;
579 	}
580 
581 	rec->allocated_bytes = params_buffer_bytes(hw_params) + LOOP_BLANK_SIZE * 4;
582 	rec->block = snd_util_mem_alloc(rec->emu->memhdr, rec->allocated_bytes);
583 	if (! rec->block)
584 		return -ENOMEM;
585 	rec->offset = EMU8000_DRAM_OFFSET + (rec->block->offset >> 1); /* in word */
586 	/* at least dma_bytes must be set for non-interleaved mode */
587 	subs->dma_buffer.bytes = params_buffer_bytes(hw_params);
588 
589 	return 0;
590 }
591 
592 /*
593  * free the memory block
594  */
595 static int emu8k_pcm_hw_free(struct snd_pcm_substream *subs)
596 {
597 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
598 
599 	if (rec->block) {
600 		int ch;
601 		for (ch = 0; ch < rec->voices; ch++)
602 			stop_voice(rec, ch); // to be sure
603 		if (rec->dram_opened)
604 			emu8k_close_dram(rec->emu);
605 		snd_util_mem_free(rec->emu->memhdr, rec->block);
606 		rec->block = NULL;
607 	}
608 	return 0;
609 }
610 
611 /*
612  */
613 static int emu8k_pcm_prepare(struct snd_pcm_substream *subs)
614 {
615 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
616 
617 	rec->pitch = 0xe000 + calc_rate_offset(subs->runtime->rate);
618 	rec->last_ptr = 0;
619 	rec->period_pos = 0;
620 
621 	rec->buf_size = subs->runtime->buffer_size;
622 	rec->period_size = subs->runtime->period_size;
623 	rec->voices = subs->runtime->channels;
624 	rec->loop_start[0] = rec->offset + LOOP_BLANK_SIZE;
625 	if (rec->voices > 1)
626 		rec->loop_start[1] = rec->loop_start[0] + rec->buf_size + LOOP_BLANK_SIZE;
627 	if (rec->voices > 1) {
628 		rec->panning[0] = 0xff;
629 		rec->panning[1] = 0x00;
630 	} else
631 		rec->panning[0] = 0x80;
632 
633 	if (! rec->dram_opened) {
634 		int err, i, ch;
635 
636 		snd_emux_terminate_all(rec->emu->emu);
637 		if ((err = emu8k_open_dram_for_pcm(rec->emu, rec->voices)) != 0)
638 			return err;
639 		rec->dram_opened = 1;
640 
641 		/* clear loop blanks */
642 		snd_emu8000_write_wait(rec->emu, 0);
643 		EMU8000_SMALW_WRITE(rec->emu, rec->offset);
644 		for (i = 0; i < LOOP_BLANK_SIZE; i++)
645 			EMU8000_SMLD_WRITE(rec->emu, 0);
646 		for (ch = 0; ch < rec->voices; ch++) {
647 			EMU8000_SMALW_WRITE(rec->emu, rec->loop_start[ch] + rec->buf_size);
648 			for (i = 0; i < LOOP_BLANK_SIZE; i++)
649 				EMU8000_SMLD_WRITE(rec->emu, 0);
650 		}
651 	}
652 
653 	setup_voice(rec, 0);
654 	if (rec->voices > 1)
655 		setup_voice(rec, 1);
656 	return 0;
657 }
658 
659 static snd_pcm_uframes_t emu8k_pcm_pointer(struct snd_pcm_substream *subs)
660 {
661 	struct snd_emu8k_pcm *rec = subs->runtime->private_data;
662 	if (rec->running)
663 		return emu8k_get_curpos(rec, 0);
664 	return 0;
665 }
666 
667 
668 static struct snd_pcm_ops emu8k_pcm_ops = {
669 	.open =		emu8k_pcm_open,
670 	.close =	emu8k_pcm_close,
671 	.ioctl =	snd_pcm_lib_ioctl,
672 	.hw_params =	emu8k_pcm_hw_params,
673 	.hw_free =	emu8k_pcm_hw_free,
674 	.prepare =	emu8k_pcm_prepare,
675 	.trigger =	emu8k_pcm_trigger,
676 	.pointer =	emu8k_pcm_pointer,
677 	.copy =		emu8k_pcm_copy,
678 	.silence =	emu8k_pcm_silence,
679 };
680 
681 
682 static void snd_emu8000_pcm_free(struct snd_pcm *pcm)
683 {
684 	struct snd_emu8000 *emu = pcm->private_data;
685 	emu->pcm = NULL;
686 }
687 
688 int snd_emu8000_pcm_new(struct snd_card *card, struct snd_emu8000 *emu, int index)
689 {
690 	struct snd_pcm *pcm;
691 	int err;
692 
693 	if ((err = snd_pcm_new(card, "Emu8000 PCM", index, 1, 0, &pcm)) < 0)
694 		return err;
695 	pcm->private_data = emu;
696 	pcm->private_free = snd_emu8000_pcm_free;
697 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &emu8k_pcm_ops);
698 	emu->pcm = pcm;
699 
700 	snd_device_register(card, pcm);
701 
702 	return 0;
703 }
704