xref: /openbmc/linux/sound/core/oss/pcm_plugin.c (revision ddc141e5)
1 /*
2  *  PCM Plug-In shared (kernel/library) code
3  *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
4  *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
5  *
6  *
7  *   This library is free software; you can redistribute it and/or modify
8  *   it under the terms of the GNU Library General Public License as
9  *   published by the Free Software Foundation; either version 2 of
10  *   the License, or (at your option) any later version.
11  *
12  *   This program is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *   GNU Library General Public License for more details.
16  *
17  *   You should have received a copy of the GNU Library General Public
18  *   License along with this library; if not, write to the Free Software
19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
20  *
21  */
22 
23 #if 0
24 #define PLUGIN_DEBUG
25 #endif
26 
27 #include <linux/slab.h>
28 #include <linux/time.h>
29 #include <linux/vmalloc.h>
30 #include <sound/core.h>
31 #include <sound/pcm.h>
32 #include <sound/pcm_params.h>
33 #include "pcm_plugin.h"
34 
35 #define snd_pcm_plug_first(plug) ((plug)->runtime->oss.plugin_first)
36 #define snd_pcm_plug_last(plug) ((plug)->runtime->oss.plugin_last)
37 
38 /*
39  *  because some cards might have rates "very close", we ignore
40  *  all "resampling" requests within +-5%
41  */
42 static int rate_match(unsigned int src_rate, unsigned int dst_rate)
43 {
44 	unsigned int low = (src_rate * 95) / 100;
45 	unsigned int high = (src_rate * 105) / 100;
46 	return dst_rate >= low && dst_rate <= high;
47 }
48 
49 static int snd_pcm_plugin_alloc(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
50 {
51 	struct snd_pcm_plugin_format *format;
52 	ssize_t width;
53 	size_t size;
54 	unsigned int channel;
55 	struct snd_pcm_plugin_channel *c;
56 
57 	if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK) {
58 		format = &plugin->src_format;
59 	} else {
60 		format = &plugin->dst_format;
61 	}
62 	if ((width = snd_pcm_format_physical_width(format->format)) < 0)
63 		return width;
64 	size = frames * format->channels * width;
65 	if (snd_BUG_ON(size % 8))
66 		return -ENXIO;
67 	size /= 8;
68 	if (plugin->buf_frames < frames) {
69 		vfree(plugin->buf);
70 		plugin->buf = vmalloc(size);
71 		plugin->buf_frames = frames;
72 	}
73 	if (!plugin->buf) {
74 		plugin->buf_frames = 0;
75 		return -ENOMEM;
76 	}
77 	c = plugin->buf_channels;
78 	if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
79 		for (channel = 0; channel < format->channels; channel++, c++) {
80 			c->frames = frames;
81 			c->enabled = 1;
82 			c->wanted = 0;
83 			c->area.addr = plugin->buf;
84 			c->area.first = channel * width;
85 			c->area.step = format->channels * width;
86 		}
87 	} else if (plugin->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) {
88 		if (snd_BUG_ON(size % format->channels))
89 			return -EINVAL;
90 		size /= format->channels;
91 		for (channel = 0; channel < format->channels; channel++, c++) {
92 			c->frames = frames;
93 			c->enabled = 1;
94 			c->wanted = 0;
95 			c->area.addr = plugin->buf + (channel * size);
96 			c->area.first = 0;
97 			c->area.step = width;
98 		}
99 	} else
100 		return -EINVAL;
101 	return 0;
102 }
103 
104 int snd_pcm_plug_alloc(struct snd_pcm_substream *plug, snd_pcm_uframes_t frames)
105 {
106 	int err;
107 	if (snd_BUG_ON(!snd_pcm_plug_first(plug)))
108 		return -ENXIO;
109 	if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
110 		struct snd_pcm_plugin *plugin = snd_pcm_plug_first(plug);
111 		while (plugin->next) {
112 			if (plugin->dst_frames)
113 				frames = plugin->dst_frames(plugin, frames);
114 			if (snd_BUG_ON(frames <= 0))
115 				return -ENXIO;
116 			plugin = plugin->next;
117 			err = snd_pcm_plugin_alloc(plugin, frames);
118 			if (err < 0)
119 				return err;
120 		}
121 	} else {
122 		struct snd_pcm_plugin *plugin = snd_pcm_plug_last(plug);
123 		while (plugin->prev) {
124 			if (plugin->src_frames)
125 				frames = plugin->src_frames(plugin, frames);
126 			if (snd_BUG_ON(frames <= 0))
127 				return -ENXIO;
128 			plugin = plugin->prev;
129 			err = snd_pcm_plugin_alloc(plugin, frames);
130 			if (err < 0)
131 				return err;
132 		}
133 	}
134 	return 0;
135 }
136 
137 
138 snd_pcm_sframes_t snd_pcm_plugin_client_channels(struct snd_pcm_plugin *plugin,
139 				       snd_pcm_uframes_t frames,
140 				       struct snd_pcm_plugin_channel **channels)
141 {
142 	*channels = plugin->buf_channels;
143 	return frames;
144 }
145 
146 int snd_pcm_plugin_build(struct snd_pcm_substream *plug,
147 			 const char *name,
148 			 struct snd_pcm_plugin_format *src_format,
149 			 struct snd_pcm_plugin_format *dst_format,
150 			 size_t extra,
151 			 struct snd_pcm_plugin **ret)
152 {
153 	struct snd_pcm_plugin *plugin;
154 	unsigned int channels;
155 
156 	if (snd_BUG_ON(!plug))
157 		return -ENXIO;
158 	if (snd_BUG_ON(!src_format || !dst_format))
159 		return -ENXIO;
160 	plugin = kzalloc(sizeof(*plugin) + extra, GFP_KERNEL);
161 	if (plugin == NULL)
162 		return -ENOMEM;
163 	plugin->name = name;
164 	plugin->plug = plug;
165 	plugin->stream = snd_pcm_plug_stream(plug);
166 	plugin->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
167 	plugin->src_format = *src_format;
168 	plugin->src_width = snd_pcm_format_physical_width(src_format->format);
169 	snd_BUG_ON(plugin->src_width <= 0);
170 	plugin->dst_format = *dst_format;
171 	plugin->dst_width = snd_pcm_format_physical_width(dst_format->format);
172 	snd_BUG_ON(plugin->dst_width <= 0);
173 	if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK)
174 		channels = src_format->channels;
175 	else
176 		channels = dst_format->channels;
177 	plugin->buf_channels = kcalloc(channels, sizeof(*plugin->buf_channels), GFP_KERNEL);
178 	if (plugin->buf_channels == NULL) {
179 		snd_pcm_plugin_free(plugin);
180 		return -ENOMEM;
181 	}
182 	plugin->client_channels = snd_pcm_plugin_client_channels;
183 	*ret = plugin;
184 	return 0;
185 }
186 
187 int snd_pcm_plugin_free(struct snd_pcm_plugin *plugin)
188 {
189 	if (! plugin)
190 		return 0;
191 	if (plugin->private_free)
192 		plugin->private_free(plugin);
193 	kfree(plugin->buf_channels);
194 	vfree(plugin->buf);
195 	kfree(plugin);
196 	return 0;
197 }
198 
199 snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t drv_frames)
200 {
201 	struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
202 	int stream;
203 
204 	if (snd_BUG_ON(!plug))
205 		return -ENXIO;
206 	if (drv_frames == 0)
207 		return 0;
208 	stream = snd_pcm_plug_stream(plug);
209 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
210 		plugin = snd_pcm_plug_last(plug);
211 		while (plugin && drv_frames > 0) {
212 			plugin_prev = plugin->prev;
213 			if (plugin->src_frames)
214 				drv_frames = plugin->src_frames(plugin, drv_frames);
215 			plugin = plugin_prev;
216 		}
217 	} else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
218 		plugin = snd_pcm_plug_first(plug);
219 		while (plugin && drv_frames > 0) {
220 			plugin_next = plugin->next;
221 			if (plugin->dst_frames)
222 				drv_frames = plugin->dst_frames(plugin, drv_frames);
223 			plugin = plugin_next;
224 		}
225 	} else
226 		snd_BUG();
227 	return drv_frames;
228 }
229 
230 snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t clt_frames)
231 {
232 	struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
233 	snd_pcm_sframes_t frames;
234 	int stream;
235 
236 	if (snd_BUG_ON(!plug))
237 		return -ENXIO;
238 	if (clt_frames == 0)
239 		return 0;
240 	frames = clt_frames;
241 	stream = snd_pcm_plug_stream(plug);
242 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
243 		plugin = snd_pcm_plug_first(plug);
244 		while (plugin && frames > 0) {
245 			plugin_next = plugin->next;
246 			if (plugin->dst_frames) {
247 				frames = plugin->dst_frames(plugin, frames);
248 				if (frames < 0)
249 					return frames;
250 			}
251 			plugin = plugin_next;
252 		}
253 	} else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
254 		plugin = snd_pcm_plug_last(plug);
255 		while (plugin) {
256 			plugin_prev = plugin->prev;
257 			if (plugin->src_frames) {
258 				frames = plugin->src_frames(plugin, frames);
259 				if (frames < 0)
260 					return frames;
261 			}
262 			plugin = plugin_prev;
263 		}
264 	} else
265 		snd_BUG();
266 	return frames;
267 }
268 
269 static int snd_pcm_plug_formats(const struct snd_mask *mask,
270 				snd_pcm_format_t format)
271 {
272 	struct snd_mask formats = *mask;
273 	u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
274 		       SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
275 		       SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
276 		       SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
277 		       SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
278 		       SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
279 		       SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
280 		       SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
281 		       SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
282 	snd_mask_set(&formats, (__force int)SNDRV_PCM_FORMAT_MU_LAW);
283 
284 	if (formats.bits[0] & (u32)linfmts)
285 		formats.bits[0] |= (u32)linfmts;
286 	if (formats.bits[1] & (u32)(linfmts >> 32))
287 		formats.bits[1] |= (u32)(linfmts >> 32);
288 	return snd_mask_test(&formats, (__force int)format);
289 }
290 
291 static snd_pcm_format_t preferred_formats[] = {
292 	SNDRV_PCM_FORMAT_S16_LE,
293 	SNDRV_PCM_FORMAT_S16_BE,
294 	SNDRV_PCM_FORMAT_U16_LE,
295 	SNDRV_PCM_FORMAT_U16_BE,
296 	SNDRV_PCM_FORMAT_S24_3LE,
297 	SNDRV_PCM_FORMAT_S24_3BE,
298 	SNDRV_PCM_FORMAT_U24_3LE,
299 	SNDRV_PCM_FORMAT_U24_3BE,
300 	SNDRV_PCM_FORMAT_S24_LE,
301 	SNDRV_PCM_FORMAT_S24_BE,
302 	SNDRV_PCM_FORMAT_U24_LE,
303 	SNDRV_PCM_FORMAT_U24_BE,
304 	SNDRV_PCM_FORMAT_S32_LE,
305 	SNDRV_PCM_FORMAT_S32_BE,
306 	SNDRV_PCM_FORMAT_U32_LE,
307 	SNDRV_PCM_FORMAT_U32_BE,
308 	SNDRV_PCM_FORMAT_S8,
309 	SNDRV_PCM_FORMAT_U8
310 };
311 
312 snd_pcm_format_t snd_pcm_plug_slave_format(snd_pcm_format_t format,
313 					   const struct snd_mask *format_mask)
314 {
315 	int i;
316 
317 	if (snd_mask_test(format_mask, (__force int)format))
318 		return format;
319 	if (!snd_pcm_plug_formats(format_mask, format))
320 		return (__force snd_pcm_format_t)-EINVAL;
321 	if (snd_pcm_format_linear(format)) {
322 		unsigned int width = snd_pcm_format_width(format);
323 		int unsignd = snd_pcm_format_unsigned(format) > 0;
324 		int big = snd_pcm_format_big_endian(format) > 0;
325 		unsigned int badness, best = -1;
326 		snd_pcm_format_t best_format = (__force snd_pcm_format_t)-1;
327 		for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
328 			snd_pcm_format_t f = preferred_formats[i];
329 			unsigned int w;
330 			if (!snd_mask_test(format_mask, (__force int)f))
331 				continue;
332 			w = snd_pcm_format_width(f);
333 			if (w >= width)
334 				badness = w - width;
335 			else
336 				badness = width - w + 32;
337 			badness += snd_pcm_format_unsigned(f) != unsignd;
338 			badness += snd_pcm_format_big_endian(f) != big;
339 			if (badness < best) {
340 				best_format = f;
341 				best = badness;
342 			}
343 		}
344 		if ((__force int)best_format >= 0)
345 			return best_format;
346 		else
347 			return (__force snd_pcm_format_t)-EINVAL;
348 	} else {
349 		switch (format) {
350 		case SNDRV_PCM_FORMAT_MU_LAW:
351 			for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
352 				snd_pcm_format_t format1 = preferred_formats[i];
353 				if (snd_mask_test(format_mask, (__force int)format1))
354 					return format1;
355 			}
356 		default:
357 			return (__force snd_pcm_format_t)-EINVAL;
358 		}
359 	}
360 }
361 
362 int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
363 				struct snd_pcm_hw_params *params,
364 				struct snd_pcm_hw_params *slave_params)
365 {
366 	struct snd_pcm_plugin_format tmpformat;
367 	struct snd_pcm_plugin_format dstformat;
368 	struct snd_pcm_plugin_format srcformat;
369 	snd_pcm_access_t src_access, dst_access;
370 	struct snd_pcm_plugin *plugin = NULL;
371 	int err;
372 	int stream = snd_pcm_plug_stream(plug);
373 	int slave_interleaved = (params_channels(slave_params) == 1 ||
374 				 params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
375 
376 	switch (stream) {
377 	case SNDRV_PCM_STREAM_PLAYBACK:
378 		dstformat.format = params_format(slave_params);
379 		dstformat.rate = params_rate(slave_params);
380 		dstformat.channels = params_channels(slave_params);
381 		srcformat.format = params_format(params);
382 		srcformat.rate = params_rate(params);
383 		srcformat.channels = params_channels(params);
384 		src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
385 		dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
386 						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
387 		break;
388 	case SNDRV_PCM_STREAM_CAPTURE:
389 		dstformat.format = params_format(params);
390 		dstformat.rate = params_rate(params);
391 		dstformat.channels = params_channels(params);
392 		srcformat.format = params_format(slave_params);
393 		srcformat.rate = params_rate(slave_params);
394 		srcformat.channels = params_channels(slave_params);
395 		src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
396 						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
397 		dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
398 		break;
399 	default:
400 		snd_BUG();
401 		return -EINVAL;
402 	}
403 	tmpformat = srcformat;
404 
405 	pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
406 		 srcformat.format,
407 		 srcformat.rate,
408 		 srcformat.channels);
409 	pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
410 		 dstformat.format,
411 		 dstformat.rate,
412 		 dstformat.channels);
413 
414 	/* Format change (linearization) */
415 	if (! rate_match(srcformat.rate, dstformat.rate) &&
416 	    ! snd_pcm_format_linear(srcformat.format)) {
417 		if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
418 			return -EINVAL;
419 		tmpformat.format = SNDRV_PCM_FORMAT_S16;
420 		err = snd_pcm_plugin_build_mulaw(plug,
421 						 &srcformat, &tmpformat,
422 						 &plugin);
423 		if (err < 0)
424 			return err;
425 		err = snd_pcm_plugin_append(plugin);
426 		if (err < 0) {
427 			snd_pcm_plugin_free(plugin);
428 			return err;
429 		}
430 		srcformat = tmpformat;
431 		src_access = dst_access;
432 	}
433 
434 	/* channels reduction */
435 	if (srcformat.channels > dstformat.channels) {
436 		tmpformat.channels = dstformat.channels;
437 		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
438 		pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
439 		if (err < 0)
440 			return err;
441 		err = snd_pcm_plugin_append(plugin);
442 		if (err < 0) {
443 			snd_pcm_plugin_free(plugin);
444 			return err;
445 		}
446 		srcformat = tmpformat;
447 		src_access = dst_access;
448 	}
449 
450 	/* rate resampling */
451 	if (!rate_match(srcformat.rate, dstformat.rate)) {
452 		if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
453 			/* convert to S16 for resampling */
454 			tmpformat.format = SNDRV_PCM_FORMAT_S16;
455 			err = snd_pcm_plugin_build_linear(plug,
456 							  &srcformat, &tmpformat,
457 							  &plugin);
458 			if (err < 0)
459 				return err;
460 			err = snd_pcm_plugin_append(plugin);
461 			if (err < 0) {
462 				snd_pcm_plugin_free(plugin);
463 				return err;
464 			}
465 			srcformat = tmpformat;
466 			src_access = dst_access;
467 		}
468 		tmpformat.rate = dstformat.rate;
469         	err = snd_pcm_plugin_build_rate(plug,
470         					&srcformat, &tmpformat,
471 						&plugin);
472 		pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
473 		if (err < 0)
474 			return err;
475 		err = snd_pcm_plugin_append(plugin);
476 		if (err < 0) {
477 			snd_pcm_plugin_free(plugin);
478 			return err;
479 		}
480 		srcformat = tmpformat;
481 		src_access = dst_access;
482         }
483 
484 	/* format change */
485 	if (srcformat.format != dstformat.format) {
486 		tmpformat.format = dstformat.format;
487 		if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
488 		    tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
489 			err = snd_pcm_plugin_build_mulaw(plug,
490 							 &srcformat, &tmpformat,
491 							 &plugin);
492 		}
493 		else if (snd_pcm_format_linear(srcformat.format) &&
494 			 snd_pcm_format_linear(tmpformat.format)) {
495 			err = snd_pcm_plugin_build_linear(plug,
496 							  &srcformat, &tmpformat,
497 							  &plugin);
498 		}
499 		else
500 			return -EINVAL;
501 		pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
502 		if (err < 0)
503 			return err;
504 		err = snd_pcm_plugin_append(plugin);
505 		if (err < 0) {
506 			snd_pcm_plugin_free(plugin);
507 			return err;
508 		}
509 		srcformat = tmpformat;
510 		src_access = dst_access;
511 	}
512 
513 	/* channels extension */
514 	if (srcformat.channels < dstformat.channels) {
515 		tmpformat.channels = dstformat.channels;
516 		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
517 		pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
518 		if (err < 0)
519 			return err;
520 		err = snd_pcm_plugin_append(plugin);
521 		if (err < 0) {
522 			snd_pcm_plugin_free(plugin);
523 			return err;
524 		}
525 		srcformat = tmpformat;
526 		src_access = dst_access;
527 	}
528 
529 	/* de-interleave */
530 	if (src_access != dst_access) {
531 		err = snd_pcm_plugin_build_copy(plug,
532 						&srcformat,
533 						&tmpformat,
534 						&plugin);
535 		pdprintf("interleave change (copy: returns %i)\n", err);
536 		if (err < 0)
537 			return err;
538 		err = snd_pcm_plugin_append(plugin);
539 		if (err < 0) {
540 			snd_pcm_plugin_free(plugin);
541 			return err;
542 		}
543 	}
544 
545 	return 0;
546 }
547 
548 snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
549 					 char *buf,
550 					 snd_pcm_uframes_t count,
551 					 struct snd_pcm_plugin_channel **channels)
552 {
553 	struct snd_pcm_plugin *plugin;
554 	struct snd_pcm_plugin_channel *v;
555 	struct snd_pcm_plugin_format *format;
556 	int width, nchannels, channel;
557 	int stream = snd_pcm_plug_stream(plug);
558 
559 	if (snd_BUG_ON(!buf))
560 		return -ENXIO;
561 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
562 		plugin = snd_pcm_plug_first(plug);
563 		format = &plugin->src_format;
564 	} else {
565 		plugin = snd_pcm_plug_last(plug);
566 		format = &plugin->dst_format;
567 	}
568 	v = plugin->buf_channels;
569 	*channels = v;
570 	if ((width = snd_pcm_format_physical_width(format->format)) < 0)
571 		return width;
572 	nchannels = format->channels;
573 	if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
574 		       format->channels > 1))
575 		return -ENXIO;
576 	for (channel = 0; channel < nchannels; channel++, v++) {
577 		v->frames = count;
578 		v->enabled = 1;
579 		v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
580 		v->area.addr = buf;
581 		v->area.first = channel * width;
582 		v->area.step = nchannels * width;
583 	}
584 	return count;
585 }
586 
587 snd_pcm_sframes_t snd_pcm_plug_write_transfer(struct snd_pcm_substream *plug, struct snd_pcm_plugin_channel *src_channels, snd_pcm_uframes_t size)
588 {
589 	struct snd_pcm_plugin *plugin, *next;
590 	struct snd_pcm_plugin_channel *dst_channels;
591 	int err;
592 	snd_pcm_sframes_t frames = size;
593 
594 	plugin = snd_pcm_plug_first(plug);
595 	while (plugin) {
596 		if (frames <= 0)
597 			return frames;
598 		if ((next = plugin->next) != NULL) {
599 			snd_pcm_sframes_t frames1 = frames;
600 			if (plugin->dst_frames) {
601 				frames1 = plugin->dst_frames(plugin, frames);
602 				if (frames1 <= 0)
603 					return frames1;
604 			}
605 			if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
606 				return err;
607 			}
608 			if (err != frames1) {
609 				frames = err;
610 				if (plugin->src_frames) {
611 					frames = plugin->src_frames(plugin, frames1);
612 					if (frames <= 0)
613 						return frames;
614 				}
615 			}
616 		} else
617 			dst_channels = NULL;
618 		pdprintf("write plugin: %s, %li\n", plugin->name, frames);
619 		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
620 			return frames;
621 		src_channels = dst_channels;
622 		plugin = next;
623 	}
624 	return snd_pcm_plug_client_size(plug, frames);
625 }
626 
627 snd_pcm_sframes_t snd_pcm_plug_read_transfer(struct snd_pcm_substream *plug, struct snd_pcm_plugin_channel *dst_channels_final, snd_pcm_uframes_t size)
628 {
629 	struct snd_pcm_plugin *plugin, *next;
630 	struct snd_pcm_plugin_channel *src_channels, *dst_channels;
631 	snd_pcm_sframes_t frames = size;
632 	int err;
633 
634 	frames = snd_pcm_plug_slave_size(plug, frames);
635 	if (frames < 0)
636 		return frames;
637 
638 	src_channels = NULL;
639 	plugin = snd_pcm_plug_first(plug);
640 	while (plugin && frames > 0) {
641 		if ((next = plugin->next) != NULL) {
642 			if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
643 				return err;
644 			}
645 			frames = err;
646 		} else {
647 			dst_channels = dst_channels_final;
648 		}
649 		pdprintf("read plugin: %s, %li\n", plugin->name, frames);
650 		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
651 			return frames;
652 		plugin = next;
653 		src_channels = dst_channels;
654 	}
655 	return frames;
656 }
657 
658 int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
659 			 size_t samples, snd_pcm_format_t format)
660 {
661 	/* FIXME: sub byte resolution and odd dst_offset */
662 	unsigned char *dst;
663 	unsigned int dst_step;
664 	int width;
665 	const unsigned char *silence;
666 	if (!dst_area->addr)
667 		return 0;
668 	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
669 	width = snd_pcm_format_physical_width(format);
670 	if (width <= 0)
671 		return -EINVAL;
672 	if (dst_area->step == (unsigned int) width && width >= 8)
673 		return snd_pcm_format_set_silence(format, dst, samples);
674 	silence = snd_pcm_format_silence_64(format);
675 	if (! silence)
676 		return -EINVAL;
677 	dst_step = dst_area->step / 8;
678 	if (width == 4) {
679 		/* Ima ADPCM */
680 		int dstbit = dst_area->first % 8;
681 		int dstbit_step = dst_area->step % 8;
682 		while (samples-- > 0) {
683 			if (dstbit)
684 				*dst &= 0xf0;
685 			else
686 				*dst &= 0x0f;
687 			dst += dst_step;
688 			dstbit += dstbit_step;
689 			if (dstbit == 8) {
690 				dst++;
691 				dstbit = 0;
692 			}
693 		}
694 	} else {
695 		width /= 8;
696 		while (samples-- > 0) {
697 			memcpy(dst, silence, width);
698 			dst += dst_step;
699 		}
700 	}
701 	return 0;
702 }
703 
704 int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
705 		      const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
706 		      size_t samples, snd_pcm_format_t format)
707 {
708 	/* FIXME: sub byte resolution and odd dst_offset */
709 	char *src, *dst;
710 	int width;
711 	int src_step, dst_step;
712 	src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
713 	if (!src_area->addr)
714 		return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
715 	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
716 	if (!dst_area->addr)
717 		return 0;
718 	width = snd_pcm_format_physical_width(format);
719 	if (width <= 0)
720 		return -EINVAL;
721 	if (src_area->step == (unsigned int) width &&
722 	    dst_area->step == (unsigned int) width && width >= 8) {
723 		size_t bytes = samples * width / 8;
724 		memcpy(dst, src, bytes);
725 		return 0;
726 	}
727 	src_step = src_area->step / 8;
728 	dst_step = dst_area->step / 8;
729 	if (width == 4) {
730 		/* Ima ADPCM */
731 		int srcbit = src_area->first % 8;
732 		int srcbit_step = src_area->step % 8;
733 		int dstbit = dst_area->first % 8;
734 		int dstbit_step = dst_area->step % 8;
735 		while (samples-- > 0) {
736 			unsigned char srcval;
737 			if (srcbit)
738 				srcval = *src & 0x0f;
739 			else
740 				srcval = (*src & 0xf0) >> 4;
741 			if (dstbit)
742 				*dst = (*dst & 0xf0) | srcval;
743 			else
744 				*dst = (*dst & 0x0f) | (srcval << 4);
745 			src += src_step;
746 			srcbit += srcbit_step;
747 			if (srcbit == 8) {
748 				src++;
749 				srcbit = 0;
750 			}
751 			dst += dst_step;
752 			dstbit += dstbit_step;
753 			if (dstbit == 8) {
754 				dst++;
755 				dstbit = 0;
756 			}
757 		}
758 	} else {
759 		width /= 8;
760 		while (samples-- > 0) {
761 			memcpy(dst, src, width);
762 			src += src_step;
763 			dst += dst_step;
764 		}
765 	}
766 	return 0;
767 }
768