xref: /openbmc/linux/sound/core/oss/pcm_plugin.c (revision ca55b2fe)
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(struct snd_mask *mask, snd_pcm_format_t format)
270 {
271 	struct snd_mask formats = *mask;
272 	u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
273 		       SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
274 		       SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
275 		       SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
276 		       SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
277 		       SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
278 		       SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
279 		       SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
280 		       SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
281 	snd_mask_set(&formats, (__force int)SNDRV_PCM_FORMAT_MU_LAW);
282 
283 	if (formats.bits[0] & (u32)linfmts)
284 		formats.bits[0] |= (u32)linfmts;
285 	if (formats.bits[1] & (u32)(linfmts >> 32))
286 		formats.bits[1] |= (u32)(linfmts >> 32);
287 	return snd_mask_test(&formats, (__force int)format);
288 }
289 
290 static snd_pcm_format_t preferred_formats[] = {
291 	SNDRV_PCM_FORMAT_S16_LE,
292 	SNDRV_PCM_FORMAT_S16_BE,
293 	SNDRV_PCM_FORMAT_U16_LE,
294 	SNDRV_PCM_FORMAT_U16_BE,
295 	SNDRV_PCM_FORMAT_S24_3LE,
296 	SNDRV_PCM_FORMAT_S24_3BE,
297 	SNDRV_PCM_FORMAT_U24_3LE,
298 	SNDRV_PCM_FORMAT_U24_3BE,
299 	SNDRV_PCM_FORMAT_S24_LE,
300 	SNDRV_PCM_FORMAT_S24_BE,
301 	SNDRV_PCM_FORMAT_U24_LE,
302 	SNDRV_PCM_FORMAT_U24_BE,
303 	SNDRV_PCM_FORMAT_S32_LE,
304 	SNDRV_PCM_FORMAT_S32_BE,
305 	SNDRV_PCM_FORMAT_U32_LE,
306 	SNDRV_PCM_FORMAT_U32_BE,
307 	SNDRV_PCM_FORMAT_S8,
308 	SNDRV_PCM_FORMAT_U8
309 };
310 
311 snd_pcm_format_t snd_pcm_plug_slave_format(snd_pcm_format_t format,
312 					   struct snd_mask *format_mask)
313 {
314 	int i;
315 
316 	if (snd_mask_test(format_mask, (__force int)format))
317 		return format;
318 	if (!snd_pcm_plug_formats(format_mask, format))
319 		return (__force snd_pcm_format_t)-EINVAL;
320 	if (snd_pcm_format_linear(format)) {
321 		unsigned int width = snd_pcm_format_width(format);
322 		int unsignd = snd_pcm_format_unsigned(format) > 0;
323 		int big = snd_pcm_format_big_endian(format) > 0;
324 		unsigned int badness, best = -1;
325 		snd_pcm_format_t best_format = (__force snd_pcm_format_t)-1;
326 		for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
327 			snd_pcm_format_t f = preferred_formats[i];
328 			unsigned int w;
329 			if (!snd_mask_test(format_mask, (__force int)f))
330 				continue;
331 			w = snd_pcm_format_width(f);
332 			if (w >= width)
333 				badness = w - width;
334 			else
335 				badness = width - w + 32;
336 			badness += snd_pcm_format_unsigned(f) != unsignd;
337 			badness += snd_pcm_format_big_endian(f) != big;
338 			if (badness < best) {
339 				best_format = f;
340 				best = badness;
341 			}
342 		}
343 		if ((__force int)best_format >= 0)
344 			return best_format;
345 		else
346 			return (__force snd_pcm_format_t)-EINVAL;
347 	} else {
348 		switch (format) {
349 		case SNDRV_PCM_FORMAT_MU_LAW:
350 			for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
351 				snd_pcm_format_t format1 = preferred_formats[i];
352 				if (snd_mask_test(format_mask, (__force int)format1))
353 					return format1;
354 			}
355 		default:
356 			return (__force snd_pcm_format_t)-EINVAL;
357 		}
358 	}
359 }
360 
361 int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
362 				struct snd_pcm_hw_params *params,
363 				struct snd_pcm_hw_params *slave_params)
364 {
365 	struct snd_pcm_plugin_format tmpformat;
366 	struct snd_pcm_plugin_format dstformat;
367 	struct snd_pcm_plugin_format srcformat;
368 	snd_pcm_access_t src_access, dst_access;
369 	struct snd_pcm_plugin *plugin = NULL;
370 	int err;
371 	int stream = snd_pcm_plug_stream(plug);
372 	int slave_interleaved = (params_channels(slave_params) == 1 ||
373 				 params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
374 
375 	switch (stream) {
376 	case SNDRV_PCM_STREAM_PLAYBACK:
377 		dstformat.format = params_format(slave_params);
378 		dstformat.rate = params_rate(slave_params);
379 		dstformat.channels = params_channels(slave_params);
380 		srcformat.format = params_format(params);
381 		srcformat.rate = params_rate(params);
382 		srcformat.channels = params_channels(params);
383 		src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
384 		dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
385 						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
386 		break;
387 	case SNDRV_PCM_STREAM_CAPTURE:
388 		dstformat.format = params_format(params);
389 		dstformat.rate = params_rate(params);
390 		dstformat.channels = params_channels(params);
391 		srcformat.format = params_format(slave_params);
392 		srcformat.rate = params_rate(slave_params);
393 		srcformat.channels = params_channels(slave_params);
394 		src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
395 						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
396 		dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
397 		break;
398 	default:
399 		snd_BUG();
400 		return -EINVAL;
401 	}
402 	tmpformat = srcformat;
403 
404 	pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
405 		 srcformat.format,
406 		 srcformat.rate,
407 		 srcformat.channels);
408 	pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
409 		 dstformat.format,
410 		 dstformat.rate,
411 		 dstformat.channels);
412 
413 	/* Format change (linearization) */
414 	if (! rate_match(srcformat.rate, dstformat.rate) &&
415 	    ! snd_pcm_format_linear(srcformat.format)) {
416 		if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
417 			return -EINVAL;
418 		tmpformat.format = SNDRV_PCM_FORMAT_S16;
419 		err = snd_pcm_plugin_build_mulaw(plug,
420 						 &srcformat, &tmpformat,
421 						 &plugin);
422 		if (err < 0)
423 			return err;
424 		err = snd_pcm_plugin_append(plugin);
425 		if (err < 0) {
426 			snd_pcm_plugin_free(plugin);
427 			return err;
428 		}
429 		srcformat = tmpformat;
430 		src_access = dst_access;
431 	}
432 
433 	/* channels reduction */
434 	if (srcformat.channels > dstformat.channels) {
435 		tmpformat.channels = dstformat.channels;
436 		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
437 		pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
438 		if (err < 0)
439 			return err;
440 		err = snd_pcm_plugin_append(plugin);
441 		if (err < 0) {
442 			snd_pcm_plugin_free(plugin);
443 			return err;
444 		}
445 		srcformat = tmpformat;
446 		src_access = dst_access;
447 	}
448 
449 	/* rate resampling */
450 	if (!rate_match(srcformat.rate, dstformat.rate)) {
451 		if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
452 			/* convert to S16 for resampling */
453 			tmpformat.format = SNDRV_PCM_FORMAT_S16;
454 			err = snd_pcm_plugin_build_linear(plug,
455 							  &srcformat, &tmpformat,
456 							  &plugin);
457 			if (err < 0)
458 				return err;
459 			err = snd_pcm_plugin_append(plugin);
460 			if (err < 0) {
461 				snd_pcm_plugin_free(plugin);
462 				return err;
463 			}
464 			srcformat = tmpformat;
465 			src_access = dst_access;
466 		}
467 		tmpformat.rate = dstformat.rate;
468         	err = snd_pcm_plugin_build_rate(plug,
469         					&srcformat, &tmpformat,
470 						&plugin);
471 		pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
472 		if (err < 0)
473 			return err;
474 		err = snd_pcm_plugin_append(plugin);
475 		if (err < 0) {
476 			snd_pcm_plugin_free(plugin);
477 			return err;
478 		}
479 		srcformat = tmpformat;
480 		src_access = dst_access;
481         }
482 
483 	/* format change */
484 	if (srcformat.format != dstformat.format) {
485 		tmpformat.format = dstformat.format;
486 		if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
487 		    tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
488 			err = snd_pcm_plugin_build_mulaw(plug,
489 							 &srcformat, &tmpformat,
490 							 &plugin);
491 		}
492 		else if (snd_pcm_format_linear(srcformat.format) &&
493 			 snd_pcm_format_linear(tmpformat.format)) {
494 			err = snd_pcm_plugin_build_linear(plug,
495 							  &srcformat, &tmpformat,
496 							  &plugin);
497 		}
498 		else
499 			return -EINVAL;
500 		pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
501 		if (err < 0)
502 			return err;
503 		err = snd_pcm_plugin_append(plugin);
504 		if (err < 0) {
505 			snd_pcm_plugin_free(plugin);
506 			return err;
507 		}
508 		srcformat = tmpformat;
509 		src_access = dst_access;
510 	}
511 
512 	/* channels extension */
513 	if (srcformat.channels < dstformat.channels) {
514 		tmpformat.channels = dstformat.channels;
515 		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
516 		pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
517 		if (err < 0)
518 			return err;
519 		err = snd_pcm_plugin_append(plugin);
520 		if (err < 0) {
521 			snd_pcm_plugin_free(plugin);
522 			return err;
523 		}
524 		srcformat = tmpformat;
525 		src_access = dst_access;
526 	}
527 
528 	/* de-interleave */
529 	if (src_access != dst_access) {
530 		err = snd_pcm_plugin_build_copy(plug,
531 						&srcformat,
532 						&tmpformat,
533 						&plugin);
534 		pdprintf("interleave change (copy: returns %i)\n", err);
535 		if (err < 0)
536 			return err;
537 		err = snd_pcm_plugin_append(plugin);
538 		if (err < 0) {
539 			snd_pcm_plugin_free(plugin);
540 			return err;
541 		}
542 	}
543 
544 	return 0;
545 }
546 
547 snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
548 					 char *buf,
549 					 snd_pcm_uframes_t count,
550 					 struct snd_pcm_plugin_channel **channels)
551 {
552 	struct snd_pcm_plugin *plugin;
553 	struct snd_pcm_plugin_channel *v;
554 	struct snd_pcm_plugin_format *format;
555 	int width, nchannels, channel;
556 	int stream = snd_pcm_plug_stream(plug);
557 
558 	if (snd_BUG_ON(!buf))
559 		return -ENXIO;
560 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
561 		plugin = snd_pcm_plug_first(plug);
562 		format = &plugin->src_format;
563 	} else {
564 		plugin = snd_pcm_plug_last(plug);
565 		format = &plugin->dst_format;
566 	}
567 	v = plugin->buf_channels;
568 	*channels = v;
569 	if ((width = snd_pcm_format_physical_width(format->format)) < 0)
570 		return width;
571 	nchannels = format->channels;
572 	if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
573 		       format->channels > 1))
574 		return -ENXIO;
575 	for (channel = 0; channel < nchannels; channel++, v++) {
576 		v->frames = count;
577 		v->enabled = 1;
578 		v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
579 		v->area.addr = buf;
580 		v->area.first = channel * width;
581 		v->area.step = nchannels * width;
582 	}
583 	return count;
584 }
585 
586 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)
587 {
588 	struct snd_pcm_plugin *plugin, *next;
589 	struct snd_pcm_plugin_channel *dst_channels;
590 	int err;
591 	snd_pcm_sframes_t frames = size;
592 
593 	plugin = snd_pcm_plug_first(plug);
594 	while (plugin && frames > 0) {
595 		if ((next = plugin->next) != NULL) {
596 			snd_pcm_sframes_t frames1 = frames;
597 			if (plugin->dst_frames)
598 				frames1 = plugin->dst_frames(plugin, frames);
599 			if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
600 				return err;
601 			}
602 			if (err != frames1) {
603 				frames = err;
604 				if (plugin->src_frames)
605 					frames = plugin->src_frames(plugin, frames1);
606 			}
607 		} else
608 			dst_channels = NULL;
609 		pdprintf("write plugin: %s, %li\n", plugin->name, frames);
610 		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
611 			return frames;
612 		src_channels = dst_channels;
613 		plugin = next;
614 	}
615 	return snd_pcm_plug_client_size(plug, frames);
616 }
617 
618 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)
619 {
620 	struct snd_pcm_plugin *plugin, *next;
621 	struct snd_pcm_plugin_channel *src_channels, *dst_channels;
622 	snd_pcm_sframes_t frames = size;
623 	int err;
624 
625 	frames = snd_pcm_plug_slave_size(plug, frames);
626 	if (frames < 0)
627 		return frames;
628 
629 	src_channels = NULL;
630 	plugin = snd_pcm_plug_first(plug);
631 	while (plugin && frames > 0) {
632 		if ((next = plugin->next) != NULL) {
633 			if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
634 				return err;
635 			}
636 			frames = err;
637 		} else {
638 			dst_channels = dst_channels_final;
639 		}
640 		pdprintf("read plugin: %s, %li\n", plugin->name, frames);
641 		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
642 			return frames;
643 		plugin = next;
644 		src_channels = dst_channels;
645 	}
646 	return frames;
647 }
648 
649 int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
650 			 size_t samples, snd_pcm_format_t format)
651 {
652 	/* FIXME: sub byte resolution and odd dst_offset */
653 	unsigned char *dst;
654 	unsigned int dst_step;
655 	int width;
656 	const unsigned char *silence;
657 	if (!dst_area->addr)
658 		return 0;
659 	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
660 	width = snd_pcm_format_physical_width(format);
661 	if (width <= 0)
662 		return -EINVAL;
663 	if (dst_area->step == (unsigned int) width && width >= 8)
664 		return snd_pcm_format_set_silence(format, dst, samples);
665 	silence = snd_pcm_format_silence_64(format);
666 	if (! silence)
667 		return -EINVAL;
668 	dst_step = dst_area->step / 8;
669 	if (width == 4) {
670 		/* Ima ADPCM */
671 		int dstbit = dst_area->first % 8;
672 		int dstbit_step = dst_area->step % 8;
673 		while (samples-- > 0) {
674 			if (dstbit)
675 				*dst &= 0xf0;
676 			else
677 				*dst &= 0x0f;
678 			dst += dst_step;
679 			dstbit += dstbit_step;
680 			if (dstbit == 8) {
681 				dst++;
682 				dstbit = 0;
683 			}
684 		}
685 	} else {
686 		width /= 8;
687 		while (samples-- > 0) {
688 			memcpy(dst, silence, width);
689 			dst += dst_step;
690 		}
691 	}
692 	return 0;
693 }
694 
695 int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
696 		      const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
697 		      size_t samples, snd_pcm_format_t format)
698 {
699 	/* FIXME: sub byte resolution and odd dst_offset */
700 	char *src, *dst;
701 	int width;
702 	int src_step, dst_step;
703 	src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
704 	if (!src_area->addr)
705 		return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
706 	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
707 	if (!dst_area->addr)
708 		return 0;
709 	width = snd_pcm_format_physical_width(format);
710 	if (width <= 0)
711 		return -EINVAL;
712 	if (src_area->step == (unsigned int) width &&
713 	    dst_area->step == (unsigned int) width && width >= 8) {
714 		size_t bytes = samples * width / 8;
715 		memcpy(dst, src, bytes);
716 		return 0;
717 	}
718 	src_step = src_area->step / 8;
719 	dst_step = dst_area->step / 8;
720 	if (width == 4) {
721 		/* Ima ADPCM */
722 		int srcbit = src_area->first % 8;
723 		int srcbit_step = src_area->step % 8;
724 		int dstbit = dst_area->first % 8;
725 		int dstbit_step = dst_area->step % 8;
726 		while (samples-- > 0) {
727 			unsigned char srcval;
728 			if (srcbit)
729 				srcval = *src & 0x0f;
730 			else
731 				srcval = (*src & 0xf0) >> 4;
732 			if (dstbit)
733 				*dst = (*dst & 0xf0) | srcval;
734 			else
735 				*dst = (*dst & 0x0f) | (srcval << 4);
736 			src += src_step;
737 			srcbit += srcbit_step;
738 			if (srcbit == 8) {
739 				src++;
740 				srcbit = 0;
741 			}
742 			dst += dst_step;
743 			dstbit += dstbit_step;
744 			if (dstbit == 8) {
745 				dst++;
746 				dstbit = 0;
747 			}
748 		}
749 	} else {
750 		width /= 8;
751 		while (samples-- > 0) {
752 			memcpy(dst, src, width);
753 			src += src_step;
754 			dst += dst_step;
755 		}
756 	}
757 	return 0;
758 }
759