GNU Linux-libre 4.9.301-gnu1
[releases.git] / sound / core / oss / pcm_plugin.c
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_pcm_sframes_t)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_pcm_sframes_t)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 static snd_pcm_sframes_t plug_client_size(struct snd_pcm_substream *plug,
200                                           snd_pcm_uframes_t drv_frames,
201                                           bool check_size)
202 {
203         struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
204         int stream;
205
206         if (snd_BUG_ON(!plug))
207                 return -ENXIO;
208         if (drv_frames == 0)
209                 return 0;
210         stream = snd_pcm_plug_stream(plug);
211         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
212                 plugin = snd_pcm_plug_last(plug);
213                 while (plugin && drv_frames > 0) {
214                         plugin_prev = plugin->prev;
215                         if (plugin->src_frames)
216                                 drv_frames = plugin->src_frames(plugin, drv_frames);
217                         if (check_size && plugin->buf_frames &&
218                             drv_frames > plugin->buf_frames)
219                                 drv_frames = plugin->buf_frames;
220                         plugin = plugin_prev;
221                 }
222         } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
223                 plugin = snd_pcm_plug_first(plug);
224                 while (plugin && drv_frames > 0) {
225                         plugin_next = plugin->next;
226                         if (check_size && plugin->buf_frames &&
227                             drv_frames > plugin->buf_frames)
228                                 drv_frames = plugin->buf_frames;
229                         if (plugin->dst_frames)
230                                 drv_frames = plugin->dst_frames(plugin, drv_frames);
231                         plugin = plugin_next;
232                 }
233         } else
234                 snd_BUG();
235         return drv_frames;
236 }
237
238 static snd_pcm_sframes_t plug_slave_size(struct snd_pcm_substream *plug,
239                                          snd_pcm_uframes_t clt_frames,
240                                          bool check_size)
241 {
242         struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
243         snd_pcm_sframes_t frames;
244         int stream;
245         
246         if (snd_BUG_ON(!plug))
247                 return -ENXIO;
248         if (clt_frames == 0)
249                 return 0;
250         frames = clt_frames;
251         stream = snd_pcm_plug_stream(plug);
252         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
253                 plugin = snd_pcm_plug_first(plug);
254                 while (plugin && frames > 0) {
255                         plugin_next = plugin->next;
256                         if (check_size && plugin->buf_frames &&
257                             frames > plugin->buf_frames)
258                                 frames = plugin->buf_frames;
259                         if (plugin->dst_frames) {
260                                 frames = plugin->dst_frames(plugin, frames);
261                                 if (frames < 0)
262                                         return frames;
263                         }
264                         plugin = plugin_next;
265                 }
266         } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
267                 plugin = snd_pcm_plug_last(plug);
268                 while (plugin) {
269                         plugin_prev = plugin->prev;
270                         if (plugin->src_frames) {
271                                 frames = plugin->src_frames(plugin, frames);
272                                 if (frames < 0)
273                                         return frames;
274                         }
275                         if (check_size && plugin->buf_frames &&
276                             frames > plugin->buf_frames)
277                                 frames = plugin->buf_frames;
278                         plugin = plugin_prev;
279                 }
280         } else
281                 snd_BUG();
282         return frames;
283 }
284
285 snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug,
286                                            snd_pcm_uframes_t drv_frames)
287 {
288         return plug_client_size(plug, drv_frames, false);
289 }
290
291 snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug,
292                                           snd_pcm_uframes_t clt_frames)
293 {
294         return plug_slave_size(plug, clt_frames, false);
295 }
296
297 static int snd_pcm_plug_formats(struct snd_mask *mask, snd_pcm_format_t format)
298 {
299         struct snd_mask formats = *mask;
300         u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
301                        SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
302                        SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
303                        SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
304                        SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
305                        SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
306                        SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
307                        SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
308                        SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
309         snd_mask_set(&formats, (__force int)SNDRV_PCM_FORMAT_MU_LAW);
310         
311         if (formats.bits[0] & (u32)linfmts)
312                 formats.bits[0] |= (u32)linfmts;
313         if (formats.bits[1] & (u32)(linfmts >> 32))
314                 formats.bits[1] |= (u32)(linfmts >> 32);
315         return snd_mask_test(&formats, (__force int)format);
316 }
317
318 static snd_pcm_format_t preferred_formats[] = {
319         SNDRV_PCM_FORMAT_S16_LE,
320         SNDRV_PCM_FORMAT_S16_BE,
321         SNDRV_PCM_FORMAT_U16_LE,
322         SNDRV_PCM_FORMAT_U16_BE,
323         SNDRV_PCM_FORMAT_S24_3LE,
324         SNDRV_PCM_FORMAT_S24_3BE,
325         SNDRV_PCM_FORMAT_U24_3LE,
326         SNDRV_PCM_FORMAT_U24_3BE,
327         SNDRV_PCM_FORMAT_S24_LE,
328         SNDRV_PCM_FORMAT_S24_BE,
329         SNDRV_PCM_FORMAT_U24_LE,
330         SNDRV_PCM_FORMAT_U24_BE,
331         SNDRV_PCM_FORMAT_S32_LE,
332         SNDRV_PCM_FORMAT_S32_BE,
333         SNDRV_PCM_FORMAT_U32_LE,
334         SNDRV_PCM_FORMAT_U32_BE,
335         SNDRV_PCM_FORMAT_S8,
336         SNDRV_PCM_FORMAT_U8
337 };
338
339 snd_pcm_format_t snd_pcm_plug_slave_format(snd_pcm_format_t format,
340                                            struct snd_mask *format_mask)
341 {
342         int i;
343
344         if (snd_mask_test(format_mask, (__force int)format))
345                 return format;
346         if (!snd_pcm_plug_formats(format_mask, format))
347                 return (__force snd_pcm_format_t)-EINVAL;
348         if (snd_pcm_format_linear(format)) {
349                 unsigned int width = snd_pcm_format_width(format);
350                 int unsignd = snd_pcm_format_unsigned(format) > 0;
351                 int big = snd_pcm_format_big_endian(format) > 0;
352                 unsigned int badness, best = -1;
353                 snd_pcm_format_t best_format = (__force snd_pcm_format_t)-1;
354                 for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
355                         snd_pcm_format_t f = preferred_formats[i];
356                         unsigned int w;
357                         if (!snd_mask_test(format_mask, (__force int)f))
358                                 continue;
359                         w = snd_pcm_format_width(f);
360                         if (w >= width)
361                                 badness = w - width;
362                         else
363                                 badness = width - w + 32;
364                         badness += snd_pcm_format_unsigned(f) != unsignd;
365                         badness += snd_pcm_format_big_endian(f) != big;
366                         if (badness < best) {
367                                 best_format = f;
368                                 best = badness;
369                         }
370                 }
371                 if ((__force int)best_format >= 0)
372                         return best_format;
373                 else
374                         return (__force snd_pcm_format_t)-EINVAL;
375         } else {
376                 switch (format) {
377                 case SNDRV_PCM_FORMAT_MU_LAW:
378                         for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
379                                 snd_pcm_format_t format1 = preferred_formats[i];
380                                 if (snd_mask_test(format_mask, (__force int)format1))
381                                         return format1;
382                         }
383                 default:
384                         return (__force snd_pcm_format_t)-EINVAL;
385                 }
386         }
387 }
388
389 int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
390                                 struct snd_pcm_hw_params *params,
391                                 struct snd_pcm_hw_params *slave_params)
392 {
393         struct snd_pcm_plugin_format tmpformat;
394         struct snd_pcm_plugin_format dstformat;
395         struct snd_pcm_plugin_format srcformat;
396         snd_pcm_access_t src_access, dst_access;
397         struct snd_pcm_plugin *plugin = NULL;
398         int err;
399         int stream = snd_pcm_plug_stream(plug);
400         int slave_interleaved = (params_channels(slave_params) == 1 ||
401                                  params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
402
403         switch (stream) {
404         case SNDRV_PCM_STREAM_PLAYBACK:
405                 dstformat.format = params_format(slave_params);
406                 dstformat.rate = params_rate(slave_params);
407                 dstformat.channels = params_channels(slave_params);
408                 srcformat.format = params_format(params);
409                 srcformat.rate = params_rate(params);
410                 srcformat.channels = params_channels(params);
411                 src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
412                 dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
413                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
414                 break;
415         case SNDRV_PCM_STREAM_CAPTURE:
416                 dstformat.format = params_format(params);
417                 dstformat.rate = params_rate(params);
418                 dstformat.channels = params_channels(params);
419                 srcformat.format = params_format(slave_params);
420                 srcformat.rate = params_rate(slave_params);
421                 srcformat.channels = params_channels(slave_params);
422                 src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
423                                                   SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
424                 dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
425                 break;
426         default:
427                 snd_BUG();
428                 return -EINVAL;
429         }
430         tmpformat = srcformat;
431                 
432         pdprintf("srcformat: format=%i, rate=%i, channels=%i\n", 
433                  srcformat.format,
434                  srcformat.rate,
435                  srcformat.channels);
436         pdprintf("dstformat: format=%i, rate=%i, channels=%i\n", 
437                  dstformat.format,
438                  dstformat.rate,
439                  dstformat.channels);
440
441         /* Format change (linearization) */
442         if (! rate_match(srcformat.rate, dstformat.rate) &&
443             ! snd_pcm_format_linear(srcformat.format)) {
444                 if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
445                         return -EINVAL;
446                 tmpformat.format = SNDRV_PCM_FORMAT_S16;
447                 err = snd_pcm_plugin_build_mulaw(plug,
448                                                  &srcformat, &tmpformat,
449                                                  &plugin);
450                 if (err < 0)
451                         return err;
452                 err = snd_pcm_plugin_append(plugin);
453                 if (err < 0) {
454                         snd_pcm_plugin_free(plugin);
455                         return err;
456                 }
457                 srcformat = tmpformat;
458                 src_access = dst_access;
459         }
460
461         /* channels reduction */
462         if (srcformat.channels > dstformat.channels) {
463                 tmpformat.channels = dstformat.channels;
464                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
465                 pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
466                 if (err < 0)
467                         return err;
468                 err = snd_pcm_plugin_append(plugin);
469                 if (err < 0) {
470                         snd_pcm_plugin_free(plugin);
471                         return err;
472                 }
473                 srcformat = tmpformat;
474                 src_access = dst_access;
475         }
476
477         /* rate resampling */
478         if (!rate_match(srcformat.rate, dstformat.rate)) {
479                 if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
480                         /* convert to S16 for resampling */
481                         tmpformat.format = SNDRV_PCM_FORMAT_S16;
482                         err = snd_pcm_plugin_build_linear(plug,
483                                                           &srcformat, &tmpformat,
484                                                           &plugin);
485                         if (err < 0)
486                                 return err;
487                         err = snd_pcm_plugin_append(plugin);
488                         if (err < 0) {
489                                 snd_pcm_plugin_free(plugin);
490                                 return err;
491                         }
492                         srcformat = tmpformat;
493                         src_access = dst_access;
494                 }
495                 tmpformat.rate = dstformat.rate;
496                 err = snd_pcm_plugin_build_rate(plug,
497                                                 &srcformat, &tmpformat,
498                                                 &plugin);
499                 pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
500                 if (err < 0)
501                         return err;
502                 err = snd_pcm_plugin_append(plugin);
503                 if (err < 0) {
504                         snd_pcm_plugin_free(plugin);
505                         return err;
506                 }
507                 srcformat = tmpformat;
508                 src_access = dst_access;
509         }
510
511         /* format change */
512         if (srcformat.format != dstformat.format) {
513                 tmpformat.format = dstformat.format;
514                 if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
515                     tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
516                         err = snd_pcm_plugin_build_mulaw(plug,
517                                                          &srcformat, &tmpformat,
518                                                          &plugin);
519                 }
520                 else if (snd_pcm_format_linear(srcformat.format) &&
521                          snd_pcm_format_linear(tmpformat.format)) {
522                         err = snd_pcm_plugin_build_linear(plug,
523                                                           &srcformat, &tmpformat,
524                                                           &plugin);
525                 }
526                 else
527                         return -EINVAL;
528                 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
529                 if (err < 0)
530                         return err;
531                 err = snd_pcm_plugin_append(plugin);
532                 if (err < 0) {
533                         snd_pcm_plugin_free(plugin);
534                         return err;
535                 }
536                 srcformat = tmpformat;
537                 src_access = dst_access;
538         }
539
540         /* channels extension */
541         if (srcformat.channels < dstformat.channels) {
542                 tmpformat.channels = dstformat.channels;
543                 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
544                 pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
545                 if (err < 0)
546                         return err;
547                 err = snd_pcm_plugin_append(plugin);
548                 if (err < 0) {
549                         snd_pcm_plugin_free(plugin);
550                         return err;
551                 }
552                 srcformat = tmpformat;
553                 src_access = dst_access;
554         }
555
556         /* de-interleave */
557         if (src_access != dst_access) {
558                 err = snd_pcm_plugin_build_copy(plug,
559                                                 &srcformat,
560                                                 &tmpformat,
561                                                 &plugin);
562                 pdprintf("interleave change (copy: returns %i)\n", err);
563                 if (err < 0)
564                         return err;
565                 err = snd_pcm_plugin_append(plugin);
566                 if (err < 0) {
567                         snd_pcm_plugin_free(plugin);
568                         return err;
569                 }
570         }
571
572         return 0;
573 }
574
575 snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
576                                          char *buf,
577                                          snd_pcm_uframes_t count,
578                                          struct snd_pcm_plugin_channel **channels)
579 {
580         struct snd_pcm_plugin *plugin;
581         struct snd_pcm_plugin_channel *v;
582         struct snd_pcm_plugin_format *format;
583         int width, nchannels, channel;
584         int stream = snd_pcm_plug_stream(plug);
585
586         if (snd_BUG_ON(!buf))
587                 return -ENXIO;
588         if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
589                 plugin = snd_pcm_plug_first(plug);
590                 format = &plugin->src_format;
591         } else {
592                 plugin = snd_pcm_plug_last(plug);
593                 format = &plugin->dst_format;
594         }
595         v = plugin->buf_channels;
596         *channels = v;
597         if ((width = snd_pcm_format_physical_width(format->format)) < 0)
598                 return width;
599         nchannels = format->channels;
600         if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
601                        format->channels > 1))
602                 return -ENXIO;
603         for (channel = 0; channel < nchannels; channel++, v++) {
604                 v->frames = count;
605                 v->enabled = 1;
606                 v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
607                 v->area.addr = buf;
608                 v->area.first = channel * width;
609                 v->area.step = nchannels * width;
610         }
611         return count;
612 }
613
614 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)
615 {
616         struct snd_pcm_plugin *plugin, *next;
617         struct snd_pcm_plugin_channel *dst_channels;
618         int err;
619         snd_pcm_sframes_t frames = size;
620
621         plugin = snd_pcm_plug_first(plug);
622         while (plugin) {
623                 if (frames <= 0)
624                         return frames;
625                 if ((next = plugin->next) != NULL) {
626                         snd_pcm_sframes_t frames1 = frames;
627                         if (plugin->dst_frames) {
628                                 frames1 = plugin->dst_frames(plugin, frames);
629                                 if (frames1 <= 0)
630                                         return frames1;
631                         }
632                         if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
633                                 return err;
634                         }
635                         if (err != frames1) {
636                                 frames = err;
637                                 if (plugin->src_frames) {
638                                         frames = plugin->src_frames(plugin, frames1);
639                                         if (frames <= 0)
640                                                 return frames;
641                                 }
642                         }
643                 } else
644                         dst_channels = NULL;
645                 pdprintf("write plugin: %s, %li\n", plugin->name, frames);
646                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
647                         return frames;
648                 src_channels = dst_channels;
649                 plugin = next;
650         }
651         return plug_client_size(plug, frames, true);
652 }
653
654 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)
655 {
656         struct snd_pcm_plugin *plugin, *next;
657         struct snd_pcm_plugin_channel *src_channels, *dst_channels;
658         snd_pcm_sframes_t frames = size;
659         int err;
660
661         frames = plug_slave_size(plug, frames, true);
662         if (frames < 0)
663                 return frames;
664
665         src_channels = NULL;
666         plugin = snd_pcm_plug_first(plug);
667         while (plugin && frames > 0) {
668                 if ((next = plugin->next) != NULL) {
669                         if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
670                                 return err;
671                         }
672                         frames = err;
673                 } else {
674                         dst_channels = dst_channels_final;
675                 }
676                 pdprintf("read plugin: %s, %li\n", plugin->name, frames);
677                 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
678                         return frames;
679                 plugin = next;
680                 src_channels = dst_channels;
681         }
682         return frames;
683 }
684
685 int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
686                          size_t samples, snd_pcm_format_t format)
687 {
688         /* FIXME: sub byte resolution and odd dst_offset */
689         unsigned char *dst;
690         unsigned int dst_step;
691         int width;
692         const unsigned char *silence;
693         if (!dst_area->addr)
694                 return 0;
695         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
696         width = snd_pcm_format_physical_width(format);
697         if (width <= 0)
698                 return -EINVAL;
699         if (dst_area->step == (unsigned int) width && width >= 8)
700                 return snd_pcm_format_set_silence(format, dst, samples);
701         silence = snd_pcm_format_silence_64(format);
702         if (! silence)
703                 return -EINVAL;
704         dst_step = dst_area->step / 8;
705         if (width == 4) {
706                 /* Ima ADPCM */
707                 int dstbit = dst_area->first % 8;
708                 int dstbit_step = dst_area->step % 8;
709                 while (samples-- > 0) {
710                         if (dstbit)
711                                 *dst &= 0xf0;
712                         else
713                                 *dst &= 0x0f;
714                         dst += dst_step;
715                         dstbit += dstbit_step;
716                         if (dstbit == 8) {
717                                 dst++;
718                                 dstbit = 0;
719                         }
720                 }
721         } else {
722                 width /= 8;
723                 while (samples-- > 0) {
724                         memcpy(dst, silence, width);
725                         dst += dst_step;
726                 }
727         }
728         return 0;
729 }
730
731 int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
732                       const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
733                       size_t samples, snd_pcm_format_t format)
734 {
735         /* FIXME: sub byte resolution and odd dst_offset */
736         char *src, *dst;
737         int width;
738         int src_step, dst_step;
739         src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
740         if (!src_area->addr)
741                 return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
742         dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
743         if (!dst_area->addr)
744                 return 0;
745         width = snd_pcm_format_physical_width(format);
746         if (width <= 0)
747                 return -EINVAL;
748         if (src_area->step == (unsigned int) width &&
749             dst_area->step == (unsigned int) width && width >= 8) {
750                 size_t bytes = samples * width / 8;
751                 memcpy(dst, src, bytes);
752                 return 0;
753         }
754         src_step = src_area->step / 8;
755         dst_step = dst_area->step / 8;
756         if (width == 4) {
757                 /* Ima ADPCM */
758                 int srcbit = src_area->first % 8;
759                 int srcbit_step = src_area->step % 8;
760                 int dstbit = dst_area->first % 8;
761                 int dstbit_step = dst_area->step % 8;
762                 while (samples-- > 0) {
763                         unsigned char srcval;
764                         if (srcbit)
765                                 srcval = *src & 0x0f;
766                         else
767                                 srcval = (*src & 0xf0) >> 4;
768                         if (dstbit)
769                                 *dst = (*dst & 0xf0) | srcval;
770                         else
771                                 *dst = (*dst & 0x0f) | (srcval << 4);
772                         src += src_step;
773                         srcbit += srcbit_step;
774                         if (srcbit == 8) {
775                                 src++;
776                                 srcbit = 0;
777                         }
778                         dst += dst_step;
779                         dstbit += dstbit_step;
780                         if (dstbit == 8) {
781                                 dst++;
782                                 dstbit = 0;
783                         }
784                 }
785         } else {
786                 width /= 8;
787                 while (samples-- > 0) {
788                         memcpy(dst, src, width);
789                         src += src_step;
790                         dst += dst_step;
791                 }
792         }
793         return 0;
794 }