xref: /openbmc/qemu/audio/alsaaudio.c (revision 3aff6c2f)
1 /*
2  * QEMU ALSA audio driver
3  *
4  * Copyright (c) 2005 Vassili Karpov (malc)
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 #include <alsa/asoundlib.h>
25 #include "qemu-common.h"
26 #include "qemu/main-loop.h"
27 #include "audio.h"
28 
29 #if QEMU_GNUC_PREREQ(4, 3)
30 #pragma GCC diagnostic ignored "-Waddress"
31 #endif
32 
33 #define AUDIO_CAP "alsa"
34 #include "audio_int.h"
35 
36 struct pollhlp {
37     snd_pcm_t *handle;
38     struct pollfd *pfds;
39     int count;
40     int mask;
41 };
42 
43 typedef struct ALSAVoiceOut {
44     HWVoiceOut hw;
45     int wpos;
46     int pending;
47     void *pcm_buf;
48     snd_pcm_t *handle;
49     struct pollhlp pollhlp;
50 } ALSAVoiceOut;
51 
52 typedef struct ALSAVoiceIn {
53     HWVoiceIn hw;
54     snd_pcm_t *handle;
55     void *pcm_buf;
56     struct pollhlp pollhlp;
57 } ALSAVoiceIn;
58 
59 static struct {
60     int size_in_usec_in;
61     int size_in_usec_out;
62     const char *pcm_name_in;
63     const char *pcm_name_out;
64     unsigned int buffer_size_in;
65     unsigned int period_size_in;
66     unsigned int buffer_size_out;
67     unsigned int period_size_out;
68     unsigned int threshold;
69 
70     int buffer_size_in_overridden;
71     int period_size_in_overridden;
72 
73     int buffer_size_out_overridden;
74     int period_size_out_overridden;
75     int verbose;
76 } conf = {
77     .buffer_size_out = 4096,
78     .period_size_out = 1024,
79     .pcm_name_out = "default",
80     .pcm_name_in = "default",
81 };
82 
83 struct alsa_params_req {
84     int freq;
85     snd_pcm_format_t fmt;
86     int nchannels;
87     int size_in_usec;
88     int override_mask;
89     unsigned int buffer_size;
90     unsigned int period_size;
91 };
92 
93 struct alsa_params_obt {
94     int freq;
95     audfmt_e fmt;
96     int endianness;
97     int nchannels;
98     snd_pcm_uframes_t samples;
99 };
100 
101 static void GCC_FMT_ATTR (2, 3) alsa_logerr (int err, const char *fmt, ...)
102 {
103     va_list ap;
104 
105     va_start (ap, fmt);
106     AUD_vlog (AUDIO_CAP, fmt, ap);
107     va_end (ap);
108 
109     AUD_log (AUDIO_CAP, "Reason: %s\n", snd_strerror (err));
110 }
111 
112 static void GCC_FMT_ATTR (3, 4) alsa_logerr2 (
113     int err,
114     const char *typ,
115     const char *fmt,
116     ...
117     )
118 {
119     va_list ap;
120 
121     AUD_log (AUDIO_CAP, "Could not initialize %s\n", typ);
122 
123     va_start (ap, fmt);
124     AUD_vlog (AUDIO_CAP, fmt, ap);
125     va_end (ap);
126 
127     AUD_log (AUDIO_CAP, "Reason: %s\n", snd_strerror (err));
128 }
129 
130 static void alsa_fini_poll (struct pollhlp *hlp)
131 {
132     int i;
133     struct pollfd *pfds = hlp->pfds;
134 
135     if (pfds) {
136         for (i = 0; i < hlp->count; ++i) {
137             qemu_set_fd_handler (pfds[i].fd, NULL, NULL, NULL);
138         }
139         g_free (pfds);
140     }
141     hlp->pfds = NULL;
142     hlp->count = 0;
143     hlp->handle = NULL;
144 }
145 
146 static void alsa_anal_close1 (snd_pcm_t **handlep)
147 {
148     int err = snd_pcm_close (*handlep);
149     if (err) {
150         alsa_logerr (err, "Failed to close PCM handle %p\n", *handlep);
151     }
152     *handlep = NULL;
153 }
154 
155 static void alsa_anal_close (snd_pcm_t **handlep, struct pollhlp *hlp)
156 {
157     alsa_fini_poll (hlp);
158     alsa_anal_close1 (handlep);
159 }
160 
161 static int alsa_recover (snd_pcm_t *handle)
162 {
163     int err = snd_pcm_prepare (handle);
164     if (err < 0) {
165         alsa_logerr (err, "Failed to prepare handle %p\n", handle);
166         return -1;
167     }
168     return 0;
169 }
170 
171 static int alsa_resume (snd_pcm_t *handle)
172 {
173     int err = snd_pcm_resume (handle);
174     if (err < 0) {
175         alsa_logerr (err, "Failed to resume handle %p\n", handle);
176         return -1;
177     }
178     return 0;
179 }
180 
181 static void alsa_poll_handler (void *opaque)
182 {
183     int err, count;
184     snd_pcm_state_t state;
185     struct pollhlp *hlp = opaque;
186     unsigned short revents;
187 
188     count = poll (hlp->pfds, hlp->count, 0);
189     if (count < 0) {
190         dolog ("alsa_poll_handler: poll %s\n", strerror (errno));
191         return;
192     }
193 
194     if (!count) {
195         return;
196     }
197 
198     /* XXX: ALSA example uses initial count, not the one returned by
199        poll, correct? */
200     err = snd_pcm_poll_descriptors_revents (hlp->handle, hlp->pfds,
201                                             hlp->count, &revents);
202     if (err < 0) {
203         alsa_logerr (err, "snd_pcm_poll_descriptors_revents");
204         return;
205     }
206 
207     if (!(revents & hlp->mask)) {
208         if (conf.verbose) {
209             dolog ("revents = %d\n", revents);
210         }
211         return;
212     }
213 
214     state = snd_pcm_state (hlp->handle);
215     switch (state) {
216     case SND_PCM_STATE_SETUP:
217         alsa_recover (hlp->handle);
218         break;
219 
220     case SND_PCM_STATE_XRUN:
221         alsa_recover (hlp->handle);
222         break;
223 
224     case SND_PCM_STATE_SUSPENDED:
225         alsa_resume (hlp->handle);
226         break;
227 
228     case SND_PCM_STATE_PREPARED:
229         audio_run ("alsa run (prepared)");
230         break;
231 
232     case SND_PCM_STATE_RUNNING:
233         audio_run ("alsa run (running)");
234         break;
235 
236     default:
237         dolog ("Unexpected state %d\n", state);
238     }
239 }
240 
241 static int alsa_poll_helper (snd_pcm_t *handle, struct pollhlp *hlp, int mask)
242 {
243     int i, count, err;
244     struct pollfd *pfds;
245 
246     count = snd_pcm_poll_descriptors_count (handle);
247     if (count <= 0) {
248         dolog ("Could not initialize poll mode\n"
249                "Invalid number of poll descriptors %d\n", count);
250         return -1;
251     }
252 
253     pfds = audio_calloc ("alsa_poll_helper", count, sizeof (*pfds));
254     if (!pfds) {
255         dolog ("Could not initialize poll mode\n");
256         return -1;
257     }
258 
259     err = snd_pcm_poll_descriptors (handle, pfds, count);
260     if (err < 0) {
261         alsa_logerr (err, "Could not initialize poll mode\n"
262                      "Could not obtain poll descriptors\n");
263         g_free (pfds);
264         return -1;
265     }
266 
267     for (i = 0; i < count; ++i) {
268         if (pfds[i].events & POLLIN) {
269             err = qemu_set_fd_handler (pfds[i].fd, alsa_poll_handler,
270                                        NULL, hlp);
271         }
272         if (pfds[i].events & POLLOUT) {
273             if (conf.verbose) {
274                 dolog ("POLLOUT %d %d\n", i, pfds[i].fd);
275             }
276             err = qemu_set_fd_handler (pfds[i].fd, NULL,
277                                        alsa_poll_handler, hlp);
278         }
279         if (conf.verbose) {
280             dolog ("Set handler events=%#x index=%d fd=%d err=%d\n",
281                    pfds[i].events, i, pfds[i].fd, err);
282         }
283 
284         if (err) {
285             dolog ("Failed to set handler events=%#x index=%d fd=%d err=%d\n",
286                    pfds[i].events, i, pfds[i].fd, err);
287 
288             while (i--) {
289                 qemu_set_fd_handler (pfds[i].fd, NULL, NULL, NULL);
290             }
291             g_free (pfds);
292             return -1;
293         }
294     }
295     hlp->pfds = pfds;
296     hlp->count = count;
297     hlp->handle = handle;
298     hlp->mask = mask;
299     return 0;
300 }
301 
302 static int alsa_poll_out (HWVoiceOut *hw)
303 {
304     ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
305 
306     return alsa_poll_helper (alsa->handle, &alsa->pollhlp, POLLOUT);
307 }
308 
309 static int alsa_poll_in (HWVoiceIn *hw)
310 {
311     ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
312 
313     return alsa_poll_helper (alsa->handle, &alsa->pollhlp, POLLIN);
314 }
315 
316 static int alsa_write (SWVoiceOut *sw, void *buf, int len)
317 {
318     return audio_pcm_sw_write (sw, buf, len);
319 }
320 
321 static snd_pcm_format_t aud_to_alsafmt (audfmt_e fmt, int endianness)
322 {
323     switch (fmt) {
324     case AUD_FMT_S8:
325         return SND_PCM_FORMAT_S8;
326 
327     case AUD_FMT_U8:
328         return SND_PCM_FORMAT_U8;
329 
330     case AUD_FMT_S16:
331         if (endianness) {
332             return SND_PCM_FORMAT_S16_BE;
333         }
334         else {
335             return SND_PCM_FORMAT_S16_LE;
336         }
337 
338     case AUD_FMT_U16:
339         if (endianness) {
340             return SND_PCM_FORMAT_U16_BE;
341         }
342         else {
343             return SND_PCM_FORMAT_U16_LE;
344         }
345 
346     case AUD_FMT_S32:
347         if (endianness) {
348             return SND_PCM_FORMAT_S32_BE;
349         }
350         else {
351             return SND_PCM_FORMAT_S32_LE;
352         }
353 
354     case AUD_FMT_U32:
355         if (endianness) {
356             return SND_PCM_FORMAT_U32_BE;
357         }
358         else {
359             return SND_PCM_FORMAT_U32_LE;
360         }
361 
362     default:
363         dolog ("Internal logic error: Bad audio format %d\n", fmt);
364 #ifdef DEBUG_AUDIO
365         abort ();
366 #endif
367         return SND_PCM_FORMAT_U8;
368     }
369 }
370 
371 static int alsa_to_audfmt (snd_pcm_format_t alsafmt, audfmt_e *fmt,
372                            int *endianness)
373 {
374     switch (alsafmt) {
375     case SND_PCM_FORMAT_S8:
376         *endianness = 0;
377         *fmt = AUD_FMT_S8;
378         break;
379 
380     case SND_PCM_FORMAT_U8:
381         *endianness = 0;
382         *fmt = AUD_FMT_U8;
383         break;
384 
385     case SND_PCM_FORMAT_S16_LE:
386         *endianness = 0;
387         *fmt = AUD_FMT_S16;
388         break;
389 
390     case SND_PCM_FORMAT_U16_LE:
391         *endianness = 0;
392         *fmt = AUD_FMT_U16;
393         break;
394 
395     case SND_PCM_FORMAT_S16_BE:
396         *endianness = 1;
397         *fmt = AUD_FMT_S16;
398         break;
399 
400     case SND_PCM_FORMAT_U16_BE:
401         *endianness = 1;
402         *fmt = AUD_FMT_U16;
403         break;
404 
405     case SND_PCM_FORMAT_S32_LE:
406         *endianness = 0;
407         *fmt = AUD_FMT_S32;
408         break;
409 
410     case SND_PCM_FORMAT_U32_LE:
411         *endianness = 0;
412         *fmt = AUD_FMT_U32;
413         break;
414 
415     case SND_PCM_FORMAT_S32_BE:
416         *endianness = 1;
417         *fmt = AUD_FMT_S32;
418         break;
419 
420     case SND_PCM_FORMAT_U32_BE:
421         *endianness = 1;
422         *fmt = AUD_FMT_U32;
423         break;
424 
425     default:
426         dolog ("Unrecognized audio format %d\n", alsafmt);
427         return -1;
428     }
429 
430     return 0;
431 }
432 
433 static void alsa_dump_info (struct alsa_params_req *req,
434                             struct alsa_params_obt *obt,
435                             snd_pcm_format_t obtfmt)
436 {
437     dolog ("parameter | requested value | obtained value\n");
438     dolog ("format    |      %10d |     %10d\n", req->fmt, obtfmt);
439     dolog ("channels  |      %10d |     %10d\n",
440            req->nchannels, obt->nchannels);
441     dolog ("frequency |      %10d |     %10d\n", req->freq, obt->freq);
442     dolog ("============================================\n");
443     dolog ("requested: buffer size %d period size %d\n",
444            req->buffer_size, req->period_size);
445     dolog ("obtained: samples %ld\n", obt->samples);
446 }
447 
448 static void alsa_set_threshold (snd_pcm_t *handle, snd_pcm_uframes_t threshold)
449 {
450     int err;
451     snd_pcm_sw_params_t *sw_params;
452 
453     snd_pcm_sw_params_alloca (&sw_params);
454 
455     err = snd_pcm_sw_params_current (handle, sw_params);
456     if (err < 0) {
457         dolog ("Could not fully initialize DAC\n");
458         alsa_logerr (err, "Failed to get current software parameters\n");
459         return;
460     }
461 
462     err = snd_pcm_sw_params_set_start_threshold (handle, sw_params, threshold);
463     if (err < 0) {
464         dolog ("Could not fully initialize DAC\n");
465         alsa_logerr (err, "Failed to set software threshold to %ld\n",
466                      threshold);
467         return;
468     }
469 
470     err = snd_pcm_sw_params (handle, sw_params);
471     if (err < 0) {
472         dolog ("Could not fully initialize DAC\n");
473         alsa_logerr (err, "Failed to set software parameters\n");
474         return;
475     }
476 }
477 
478 static int alsa_open (int in, struct alsa_params_req *req,
479                       struct alsa_params_obt *obt, snd_pcm_t **handlep)
480 {
481     snd_pcm_t *handle;
482     snd_pcm_hw_params_t *hw_params;
483     int err;
484     int size_in_usec;
485     unsigned int freq, nchannels;
486     const char *pcm_name = in ? conf.pcm_name_in : conf.pcm_name_out;
487     snd_pcm_uframes_t obt_buffer_size;
488     const char *typ = in ? "ADC" : "DAC";
489     snd_pcm_format_t obtfmt;
490 
491     freq = req->freq;
492     nchannels = req->nchannels;
493     size_in_usec = req->size_in_usec;
494 
495     snd_pcm_hw_params_alloca (&hw_params);
496 
497     err = snd_pcm_open (
498         &handle,
499         pcm_name,
500         in ? SND_PCM_STREAM_CAPTURE : SND_PCM_STREAM_PLAYBACK,
501         SND_PCM_NONBLOCK
502         );
503     if (err < 0) {
504         alsa_logerr2 (err, typ, "Failed to open `%s':\n", pcm_name);
505         return -1;
506     }
507 
508     err = snd_pcm_hw_params_any (handle, hw_params);
509     if (err < 0) {
510         alsa_logerr2 (err, typ, "Failed to initialize hardware parameters\n");
511         goto err;
512     }
513 
514     err = snd_pcm_hw_params_set_access (
515         handle,
516         hw_params,
517         SND_PCM_ACCESS_RW_INTERLEAVED
518         );
519     if (err < 0) {
520         alsa_logerr2 (err, typ, "Failed to set access type\n");
521         goto err;
522     }
523 
524     err = snd_pcm_hw_params_set_format (handle, hw_params, req->fmt);
525     if (err < 0 && conf.verbose) {
526         alsa_logerr2 (err, typ, "Failed to set format %d\n", req->fmt);
527     }
528 
529     err = snd_pcm_hw_params_set_rate_near (handle, hw_params, &freq, 0);
530     if (err < 0) {
531         alsa_logerr2 (err, typ, "Failed to set frequency %d\n", req->freq);
532         goto err;
533     }
534 
535     err = snd_pcm_hw_params_set_channels_near (
536         handle,
537         hw_params,
538         &nchannels
539         );
540     if (err < 0) {
541         alsa_logerr2 (err, typ, "Failed to set number of channels %d\n",
542                       req->nchannels);
543         goto err;
544     }
545 
546     if (nchannels != 1 && nchannels != 2) {
547         alsa_logerr2 (err, typ,
548                       "Can not handle obtained number of channels %d\n",
549                       nchannels);
550         goto err;
551     }
552 
553     if (req->buffer_size) {
554         unsigned long obt;
555 
556         if (size_in_usec) {
557             int dir = 0;
558             unsigned int btime = req->buffer_size;
559 
560             err = snd_pcm_hw_params_set_buffer_time_near (
561                 handle,
562                 hw_params,
563                 &btime,
564                 &dir
565                 );
566             obt = btime;
567         }
568         else {
569             snd_pcm_uframes_t bsize = req->buffer_size;
570 
571             err = snd_pcm_hw_params_set_buffer_size_near (
572                 handle,
573                 hw_params,
574                 &bsize
575                 );
576             obt = bsize;
577         }
578         if (err < 0) {
579             alsa_logerr2 (err, typ, "Failed to set buffer %s to %d\n",
580                           size_in_usec ? "time" : "size", req->buffer_size);
581             goto err;
582         }
583 
584         if ((req->override_mask & 2) && (obt - req->buffer_size))
585             dolog ("Requested buffer %s %u was rejected, using %lu\n",
586                    size_in_usec ? "time" : "size", req->buffer_size, obt);
587     }
588 
589     if (req->period_size) {
590         unsigned long obt;
591 
592         if (size_in_usec) {
593             int dir = 0;
594             unsigned int ptime = req->period_size;
595 
596             err = snd_pcm_hw_params_set_period_time_near (
597                 handle,
598                 hw_params,
599                 &ptime,
600                 &dir
601                 );
602             obt = ptime;
603         }
604         else {
605             int dir = 0;
606             snd_pcm_uframes_t psize = req->period_size;
607 
608             err = snd_pcm_hw_params_set_period_size_near (
609                 handle,
610                 hw_params,
611                 &psize,
612                 &dir
613                 );
614             obt = psize;
615         }
616 
617         if (err < 0) {
618             alsa_logerr2 (err, typ, "Failed to set period %s to %d\n",
619                           size_in_usec ? "time" : "size", req->period_size);
620             goto err;
621         }
622 
623         if (((req->override_mask & 1) && (obt - req->period_size)))
624             dolog ("Requested period %s %u was rejected, using %lu\n",
625                    size_in_usec ? "time" : "size", req->period_size, obt);
626     }
627 
628     err = snd_pcm_hw_params (handle, hw_params);
629     if (err < 0) {
630         alsa_logerr2 (err, typ, "Failed to apply audio parameters\n");
631         goto err;
632     }
633 
634     err = snd_pcm_hw_params_get_buffer_size (hw_params, &obt_buffer_size);
635     if (err < 0) {
636         alsa_logerr2 (err, typ, "Failed to get buffer size\n");
637         goto err;
638     }
639 
640     err = snd_pcm_hw_params_get_format (hw_params, &obtfmt);
641     if (err < 0) {
642         alsa_logerr2 (err, typ, "Failed to get format\n");
643         goto err;
644     }
645 
646     if (alsa_to_audfmt (obtfmt, &obt->fmt, &obt->endianness)) {
647         dolog ("Invalid format was returned %d\n", obtfmt);
648         goto err;
649     }
650 
651     err = snd_pcm_prepare (handle);
652     if (err < 0) {
653         alsa_logerr2 (err, typ, "Could not prepare handle %p\n", handle);
654         goto err;
655     }
656 
657     if (!in && conf.threshold) {
658         snd_pcm_uframes_t threshold;
659         int bytes_per_sec;
660 
661         bytes_per_sec = freq << (nchannels == 2);
662 
663         switch (obt->fmt) {
664         case AUD_FMT_S8:
665         case AUD_FMT_U8:
666             break;
667 
668         case AUD_FMT_S16:
669         case AUD_FMT_U16:
670             bytes_per_sec <<= 1;
671             break;
672 
673         case AUD_FMT_S32:
674         case AUD_FMT_U32:
675             bytes_per_sec <<= 2;
676             break;
677         }
678 
679         threshold = (conf.threshold * bytes_per_sec) / 1000;
680         alsa_set_threshold (handle, threshold);
681     }
682 
683     obt->nchannels = nchannels;
684     obt->freq = freq;
685     obt->samples = obt_buffer_size;
686 
687     *handlep = handle;
688 
689     if (conf.verbose &&
690         (obtfmt != req->fmt ||
691          obt->nchannels != req->nchannels ||
692          obt->freq != req->freq)) {
693         dolog ("Audio parameters for %s\n", typ);
694         alsa_dump_info (req, obt, obtfmt);
695     }
696 
697 #ifdef DEBUG
698     alsa_dump_info (req, obt, obtfmt);
699 #endif
700     return 0;
701 
702  err:
703     alsa_anal_close1 (&handle);
704     return -1;
705 }
706 
707 static snd_pcm_sframes_t alsa_get_avail (snd_pcm_t *handle)
708 {
709     snd_pcm_sframes_t avail;
710 
711     avail = snd_pcm_avail_update (handle);
712     if (avail < 0) {
713         if (avail == -EPIPE) {
714             if (!alsa_recover (handle)) {
715                 avail = snd_pcm_avail_update (handle);
716             }
717         }
718 
719         if (avail < 0) {
720             alsa_logerr (avail,
721                          "Could not obtain number of available frames\n");
722             return -1;
723         }
724     }
725 
726     return avail;
727 }
728 
729 static void alsa_write_pending (ALSAVoiceOut *alsa)
730 {
731     HWVoiceOut *hw = &alsa->hw;
732 
733     while (alsa->pending) {
734         int left_till_end_samples = hw->samples - alsa->wpos;
735         int len = audio_MIN (alsa->pending, left_till_end_samples);
736         char *src = advance (alsa->pcm_buf, alsa->wpos << hw->info.shift);
737 
738         while (len) {
739             snd_pcm_sframes_t written;
740 
741             written = snd_pcm_writei (alsa->handle, src, len);
742 
743             if (written <= 0) {
744                 switch (written) {
745                 case 0:
746                     if (conf.verbose) {
747                         dolog ("Failed to write %d frames (wrote zero)\n", len);
748                     }
749                     return;
750 
751                 case -EPIPE:
752                     if (alsa_recover (alsa->handle)) {
753                         alsa_logerr (written, "Failed to write %d frames\n",
754                                      len);
755                         return;
756                     }
757                     if (conf.verbose) {
758                         dolog ("Recovering from playback xrun\n");
759                     }
760                     continue;
761 
762                 case -ESTRPIPE:
763                     /* stream is suspended and waiting for an
764                        application recovery */
765                     if (alsa_resume (alsa->handle)) {
766                         alsa_logerr (written, "Failed to write %d frames\n",
767                                      len);
768                         return;
769                     }
770                     if (conf.verbose) {
771                         dolog ("Resuming suspended output stream\n");
772                     }
773                     continue;
774 
775                 case -EAGAIN:
776                     return;
777 
778                 default:
779                     alsa_logerr (written, "Failed to write %d frames from %p\n",
780                                  len, src);
781                     return;
782                 }
783             }
784 
785             alsa->wpos = (alsa->wpos + written) % hw->samples;
786             alsa->pending -= written;
787             len -= written;
788         }
789     }
790 }
791 
792 static int alsa_run_out (HWVoiceOut *hw, int live)
793 {
794     ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
795     int decr;
796     snd_pcm_sframes_t avail;
797 
798     avail = alsa_get_avail (alsa->handle);
799     if (avail < 0) {
800         dolog ("Could not get number of available playback frames\n");
801         return 0;
802     }
803 
804     decr = audio_MIN (live, avail);
805     decr = audio_pcm_hw_clip_out (hw, alsa->pcm_buf, decr, alsa->pending);
806     alsa->pending += decr;
807     alsa_write_pending (alsa);
808     return decr;
809 }
810 
811 static void alsa_fini_out (HWVoiceOut *hw)
812 {
813     ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
814 
815     ldebug ("alsa_fini\n");
816     alsa_anal_close (&alsa->handle, &alsa->pollhlp);
817 
818     g_free(alsa->pcm_buf);
819     alsa->pcm_buf = NULL;
820 }
821 
822 static int alsa_init_out (HWVoiceOut *hw, struct audsettings *as)
823 {
824     ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
825     struct alsa_params_req req;
826     struct alsa_params_obt obt;
827     snd_pcm_t *handle;
828     struct audsettings obt_as;
829 
830     req.fmt = aud_to_alsafmt (as->fmt, as->endianness);
831     req.freq = as->freq;
832     req.nchannels = as->nchannels;
833     req.period_size = conf.period_size_out;
834     req.buffer_size = conf.buffer_size_out;
835     req.size_in_usec = conf.size_in_usec_out;
836     req.override_mask =
837         (conf.period_size_out_overridden ? 1 : 0) |
838         (conf.buffer_size_out_overridden ? 2 : 0);
839 
840     if (alsa_open (0, &req, &obt, &handle)) {
841         return -1;
842     }
843 
844     obt_as.freq = obt.freq;
845     obt_as.nchannels = obt.nchannels;
846     obt_as.fmt = obt.fmt;
847     obt_as.endianness = obt.endianness;
848 
849     audio_pcm_init_info (&hw->info, &obt_as);
850     hw->samples = obt.samples;
851 
852     alsa->pcm_buf = audio_calloc (AUDIO_FUNC, obt.samples, 1 << hw->info.shift);
853     if (!alsa->pcm_buf) {
854         dolog ("Could not allocate DAC buffer (%d samples, each %d bytes)\n",
855                hw->samples, 1 << hw->info.shift);
856         alsa_anal_close1 (&handle);
857         return -1;
858     }
859 
860     alsa->handle = handle;
861     return 0;
862 }
863 
864 #define VOICE_CTL_PAUSE 0
865 #define VOICE_CTL_PREPARE 1
866 #define VOICE_CTL_START 2
867 
868 static int alsa_voice_ctl (snd_pcm_t *handle, const char *typ, int ctl)
869 {
870     int err;
871 
872     if (ctl == VOICE_CTL_PAUSE) {
873         err = snd_pcm_drop (handle);
874         if (err < 0) {
875             alsa_logerr (err, "Could not stop %s\n", typ);
876             return -1;
877         }
878     }
879     else {
880         err = snd_pcm_prepare (handle);
881         if (err < 0) {
882             alsa_logerr (err, "Could not prepare handle for %s\n", typ);
883             return -1;
884         }
885         if (ctl == VOICE_CTL_START) {
886             err = snd_pcm_start(handle);
887             if (err < 0) {
888                 alsa_logerr (err, "Could not start handle for %s\n", typ);
889                 return -1;
890             }
891         }
892     }
893 
894     return 0;
895 }
896 
897 static int alsa_ctl_out (HWVoiceOut *hw, int cmd, ...)
898 {
899     ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
900 
901     switch (cmd) {
902     case VOICE_ENABLE:
903         {
904             va_list ap;
905             int poll_mode;
906 
907             va_start (ap, cmd);
908             poll_mode = va_arg (ap, int);
909             va_end (ap);
910 
911             ldebug ("enabling voice\n");
912             if (poll_mode && alsa_poll_out (hw)) {
913                 poll_mode = 0;
914             }
915             hw->poll_mode = poll_mode;
916             return alsa_voice_ctl (alsa->handle, "playback", VOICE_CTL_PREPARE);
917         }
918 
919     case VOICE_DISABLE:
920         ldebug ("disabling voice\n");
921         if (hw->poll_mode) {
922             hw->poll_mode = 0;
923             alsa_fini_poll (&alsa->pollhlp);
924         }
925         return alsa_voice_ctl (alsa->handle, "playback", VOICE_CTL_PAUSE);
926     }
927 
928     return -1;
929 }
930 
931 static int alsa_init_in (HWVoiceIn *hw, struct audsettings *as)
932 {
933     ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
934     struct alsa_params_req req;
935     struct alsa_params_obt obt;
936     snd_pcm_t *handle;
937     struct audsettings obt_as;
938 
939     req.fmt = aud_to_alsafmt (as->fmt, as->endianness);
940     req.freq = as->freq;
941     req.nchannels = as->nchannels;
942     req.period_size = conf.period_size_in;
943     req.buffer_size = conf.buffer_size_in;
944     req.size_in_usec = conf.size_in_usec_in;
945     req.override_mask =
946         (conf.period_size_in_overridden ? 1 : 0) |
947         (conf.buffer_size_in_overridden ? 2 : 0);
948 
949     if (alsa_open (1, &req, &obt, &handle)) {
950         return -1;
951     }
952 
953     obt_as.freq = obt.freq;
954     obt_as.nchannels = obt.nchannels;
955     obt_as.fmt = obt.fmt;
956     obt_as.endianness = obt.endianness;
957 
958     audio_pcm_init_info (&hw->info, &obt_as);
959     hw->samples = obt.samples;
960 
961     alsa->pcm_buf = audio_calloc (AUDIO_FUNC, hw->samples, 1 << hw->info.shift);
962     if (!alsa->pcm_buf) {
963         dolog ("Could not allocate ADC buffer (%d samples, each %d bytes)\n",
964                hw->samples, 1 << hw->info.shift);
965         alsa_anal_close1 (&handle);
966         return -1;
967     }
968 
969     alsa->handle = handle;
970     return 0;
971 }
972 
973 static void alsa_fini_in (HWVoiceIn *hw)
974 {
975     ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
976 
977     alsa_anal_close (&alsa->handle, &alsa->pollhlp);
978 
979     g_free(alsa->pcm_buf);
980     alsa->pcm_buf = NULL;
981 }
982 
983 static int alsa_run_in (HWVoiceIn *hw)
984 {
985     ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
986     int hwshift = hw->info.shift;
987     int i;
988     int live = audio_pcm_hw_get_live_in (hw);
989     int dead = hw->samples - live;
990     int decr;
991     struct {
992         int add;
993         int len;
994     } bufs[2] = {
995         { .add = hw->wpos, .len = 0 },
996         { .add = 0,        .len = 0 }
997     };
998     snd_pcm_sframes_t avail;
999     snd_pcm_uframes_t read_samples = 0;
1000 
1001     if (!dead) {
1002         return 0;
1003     }
1004 
1005     avail = alsa_get_avail (alsa->handle);
1006     if (avail < 0) {
1007         dolog ("Could not get number of captured frames\n");
1008         return 0;
1009     }
1010 
1011     if (!avail) {
1012         snd_pcm_state_t state;
1013 
1014         state = snd_pcm_state (alsa->handle);
1015         switch (state) {
1016         case SND_PCM_STATE_PREPARED:
1017             avail = hw->samples;
1018             break;
1019         case SND_PCM_STATE_SUSPENDED:
1020             /* stream is suspended and waiting for an application recovery */
1021             if (alsa_resume (alsa->handle)) {
1022                 dolog ("Failed to resume suspended input stream\n");
1023                 return 0;
1024             }
1025             if (conf.verbose) {
1026                 dolog ("Resuming suspended input stream\n");
1027             }
1028             break;
1029         default:
1030             if (conf.verbose) {
1031                 dolog ("No frames available and ALSA state is %d\n", state);
1032             }
1033             return 0;
1034         }
1035     }
1036 
1037     decr = audio_MIN (dead, avail);
1038     if (!decr) {
1039         return 0;
1040     }
1041 
1042     if (hw->wpos + decr > hw->samples) {
1043         bufs[0].len = (hw->samples - hw->wpos);
1044         bufs[1].len = (decr - (hw->samples - hw->wpos));
1045     }
1046     else {
1047         bufs[0].len = decr;
1048     }
1049 
1050     for (i = 0; i < 2; ++i) {
1051         void *src;
1052         struct st_sample *dst;
1053         snd_pcm_sframes_t nread;
1054         snd_pcm_uframes_t len;
1055 
1056         len = bufs[i].len;
1057 
1058         src = advance (alsa->pcm_buf, bufs[i].add << hwshift);
1059         dst = hw->conv_buf + bufs[i].add;
1060 
1061         while (len) {
1062             nread = snd_pcm_readi (alsa->handle, src, len);
1063 
1064             if (nread <= 0) {
1065                 switch (nread) {
1066                 case 0:
1067                     if (conf.verbose) {
1068                         dolog ("Failed to read %ld frames (read zero)\n", len);
1069                     }
1070                     goto exit;
1071 
1072                 case -EPIPE:
1073                     if (alsa_recover (alsa->handle)) {
1074                         alsa_logerr (nread, "Failed to read %ld frames\n", len);
1075                         goto exit;
1076                     }
1077                     if (conf.verbose) {
1078                         dolog ("Recovering from capture xrun\n");
1079                     }
1080                     continue;
1081 
1082                 case -EAGAIN:
1083                     goto exit;
1084 
1085                 default:
1086                     alsa_logerr (
1087                         nread,
1088                         "Failed to read %ld frames from %p\n",
1089                         len,
1090                         src
1091                         );
1092                     goto exit;
1093                 }
1094             }
1095 
1096             hw->conv (dst, src, nread);
1097 
1098             src = advance (src, nread << hwshift);
1099             dst += nread;
1100 
1101             read_samples += nread;
1102             len -= nread;
1103         }
1104     }
1105 
1106  exit:
1107     hw->wpos = (hw->wpos + read_samples) % hw->samples;
1108     return read_samples;
1109 }
1110 
1111 static int alsa_read (SWVoiceIn *sw, void *buf, int size)
1112 {
1113     return audio_pcm_sw_read (sw, buf, size);
1114 }
1115 
1116 static int alsa_ctl_in (HWVoiceIn *hw, int cmd, ...)
1117 {
1118     ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
1119 
1120     switch (cmd) {
1121     case VOICE_ENABLE:
1122         {
1123             va_list ap;
1124             int poll_mode;
1125 
1126             va_start (ap, cmd);
1127             poll_mode = va_arg (ap, int);
1128             va_end (ap);
1129 
1130             ldebug ("enabling voice\n");
1131             if (poll_mode && alsa_poll_in (hw)) {
1132                 poll_mode = 0;
1133             }
1134             hw->poll_mode = poll_mode;
1135 
1136             return alsa_voice_ctl (alsa->handle, "capture", VOICE_CTL_START);
1137         }
1138 
1139     case VOICE_DISABLE:
1140         ldebug ("disabling voice\n");
1141         if (hw->poll_mode) {
1142             hw->poll_mode = 0;
1143             alsa_fini_poll (&alsa->pollhlp);
1144         }
1145         return alsa_voice_ctl (alsa->handle, "capture", VOICE_CTL_PAUSE);
1146     }
1147 
1148     return -1;
1149 }
1150 
1151 static void *alsa_audio_init (void)
1152 {
1153     return &conf;
1154 }
1155 
1156 static void alsa_audio_fini (void *opaque)
1157 {
1158     (void) opaque;
1159 }
1160 
1161 static struct audio_option alsa_options[] = {
1162     {
1163         .name        = "DAC_SIZE_IN_USEC",
1164         .tag         = AUD_OPT_BOOL,
1165         .valp        = &conf.size_in_usec_out,
1166         .descr       = "DAC period/buffer size in microseconds (otherwise in frames)"
1167     },
1168     {
1169         .name        = "DAC_PERIOD_SIZE",
1170         .tag         = AUD_OPT_INT,
1171         .valp        = &conf.period_size_out,
1172         .descr       = "DAC period size (0 to go with system default)",
1173         .overriddenp = &conf.period_size_out_overridden
1174     },
1175     {
1176         .name        = "DAC_BUFFER_SIZE",
1177         .tag         = AUD_OPT_INT,
1178         .valp        = &conf.buffer_size_out,
1179         .descr       = "DAC buffer size (0 to go with system default)",
1180         .overriddenp = &conf.buffer_size_out_overridden
1181     },
1182     {
1183         .name        = "ADC_SIZE_IN_USEC",
1184         .tag         = AUD_OPT_BOOL,
1185         .valp        = &conf.size_in_usec_in,
1186         .descr       =
1187         "ADC period/buffer size in microseconds (otherwise in frames)"
1188     },
1189     {
1190         .name        = "ADC_PERIOD_SIZE",
1191         .tag         = AUD_OPT_INT,
1192         .valp        = &conf.period_size_in,
1193         .descr       = "ADC period size (0 to go with system default)",
1194         .overriddenp = &conf.period_size_in_overridden
1195     },
1196     {
1197         .name        = "ADC_BUFFER_SIZE",
1198         .tag         = AUD_OPT_INT,
1199         .valp        = &conf.buffer_size_in,
1200         .descr       = "ADC buffer size (0 to go with system default)",
1201         .overriddenp = &conf.buffer_size_in_overridden
1202     },
1203     {
1204         .name        = "THRESHOLD",
1205         .tag         = AUD_OPT_INT,
1206         .valp        = &conf.threshold,
1207         .descr       = "(undocumented)"
1208     },
1209     {
1210         .name        = "DAC_DEV",
1211         .tag         = AUD_OPT_STR,
1212         .valp        = &conf.pcm_name_out,
1213         .descr       = "DAC device name (for instance dmix)"
1214     },
1215     {
1216         .name        = "ADC_DEV",
1217         .tag         = AUD_OPT_STR,
1218         .valp        = &conf.pcm_name_in,
1219         .descr       = "ADC device name"
1220     },
1221     {
1222         .name        = "VERBOSE",
1223         .tag         = AUD_OPT_BOOL,
1224         .valp        = &conf.verbose,
1225         .descr       = "Behave in a more verbose way"
1226     },
1227     { /* End of list */ }
1228 };
1229 
1230 static struct audio_pcm_ops alsa_pcm_ops = {
1231     .init_out = alsa_init_out,
1232     .fini_out = alsa_fini_out,
1233     .run_out  = alsa_run_out,
1234     .write    = alsa_write,
1235     .ctl_out  = alsa_ctl_out,
1236 
1237     .init_in  = alsa_init_in,
1238     .fini_in  = alsa_fini_in,
1239     .run_in   = alsa_run_in,
1240     .read     = alsa_read,
1241     .ctl_in   = alsa_ctl_in,
1242 };
1243 
1244 struct audio_driver alsa_audio_driver = {
1245     .name           = "alsa",
1246     .descr          = "ALSA http://www.alsa-project.org",
1247     .options        = alsa_options,
1248     .init           = alsa_audio_init,
1249     .fini           = alsa_audio_fini,
1250     .pcm_ops        = &alsa_pcm_ops,
1251     .can_be_default = 1,
1252     .max_voices_out = INT_MAX,
1253     .max_voices_in  = INT_MAX,
1254     .voice_size_out = sizeof (ALSAVoiceOut),
1255     .voice_size_in  = sizeof (ALSAVoiceIn)
1256 };
1257