xref: /openbmc/qemu/audio/alsaaudio.c (revision 71af014f1451bec3244e086298813b5aa7b2a0ee)
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-char.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         qemu_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         qemu_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             qemu_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)
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         return SND_PCM_FORMAT_S16_LE;
332 
333     case AUD_FMT_U16:
334         return SND_PCM_FORMAT_U16_LE;
335 
336     case AUD_FMT_S32:
337         return SND_PCM_FORMAT_S32_LE;
338 
339     case AUD_FMT_U32:
340         return SND_PCM_FORMAT_U32_LE;
341 
342     default:
343         dolog ("Internal logic error: Bad audio format %d\n", fmt);
344 #ifdef DEBUG_AUDIO
345         abort ();
346 #endif
347         return SND_PCM_FORMAT_U8;
348     }
349 }
350 
351 static int alsa_to_audfmt (snd_pcm_format_t alsafmt, audfmt_e *fmt,
352                            int *endianness)
353 {
354     switch (alsafmt) {
355     case SND_PCM_FORMAT_S8:
356         *endianness = 0;
357         *fmt = AUD_FMT_S8;
358         break;
359 
360     case SND_PCM_FORMAT_U8:
361         *endianness = 0;
362         *fmt = AUD_FMT_U8;
363         break;
364 
365     case SND_PCM_FORMAT_S16_LE:
366         *endianness = 0;
367         *fmt = AUD_FMT_S16;
368         break;
369 
370     case SND_PCM_FORMAT_U16_LE:
371         *endianness = 0;
372         *fmt = AUD_FMT_U16;
373         break;
374 
375     case SND_PCM_FORMAT_S16_BE:
376         *endianness = 1;
377         *fmt = AUD_FMT_S16;
378         break;
379 
380     case SND_PCM_FORMAT_U16_BE:
381         *endianness = 1;
382         *fmt = AUD_FMT_U16;
383         break;
384 
385     case SND_PCM_FORMAT_S32_LE:
386         *endianness = 0;
387         *fmt = AUD_FMT_S32;
388         break;
389 
390     case SND_PCM_FORMAT_U32_LE:
391         *endianness = 0;
392         *fmt = AUD_FMT_U32;
393         break;
394 
395     case SND_PCM_FORMAT_S32_BE:
396         *endianness = 1;
397         *fmt = AUD_FMT_S32;
398         break;
399 
400     case SND_PCM_FORMAT_U32_BE:
401         *endianness = 1;
402         *fmt = AUD_FMT_U32;
403         break;
404 
405     default:
406         dolog ("Unrecognized audio format %d\n", alsafmt);
407         return -1;
408     }
409 
410     return 0;
411 }
412 
413 static void alsa_dump_info (struct alsa_params_req *req,
414                             struct alsa_params_obt *obt,
415                             snd_pcm_format_t obtfmt)
416 {
417     dolog ("parameter | requested value | obtained value\n");
418     dolog ("format    |      %10d |     %10d\n", req->fmt, obtfmt);
419     dolog ("channels  |      %10d |     %10d\n",
420            req->nchannels, obt->nchannels);
421     dolog ("frequency |      %10d |     %10d\n", req->freq, obt->freq);
422     dolog ("============================================\n");
423     dolog ("requested: buffer size %d period size %d\n",
424            req->buffer_size, req->period_size);
425     dolog ("obtained: samples %ld\n", obt->samples);
426 }
427 
428 static void alsa_set_threshold (snd_pcm_t *handle, snd_pcm_uframes_t threshold)
429 {
430     int err;
431     snd_pcm_sw_params_t *sw_params;
432 
433     snd_pcm_sw_params_alloca (&sw_params);
434 
435     err = snd_pcm_sw_params_current (handle, sw_params);
436     if (err < 0) {
437         dolog ("Could not fully initialize DAC\n");
438         alsa_logerr (err, "Failed to get current software parameters\n");
439         return;
440     }
441 
442     err = snd_pcm_sw_params_set_start_threshold (handle, sw_params, threshold);
443     if (err < 0) {
444         dolog ("Could not fully initialize DAC\n");
445         alsa_logerr (err, "Failed to set software threshold to %ld\n",
446                      threshold);
447         return;
448     }
449 
450     err = snd_pcm_sw_params (handle, sw_params);
451     if (err < 0) {
452         dolog ("Could not fully initialize DAC\n");
453         alsa_logerr (err, "Failed to set software parameters\n");
454         return;
455     }
456 }
457 
458 static int alsa_open (int in, struct alsa_params_req *req,
459                       struct alsa_params_obt *obt, snd_pcm_t **handlep)
460 {
461     snd_pcm_t *handle;
462     snd_pcm_hw_params_t *hw_params;
463     int err;
464     int size_in_usec;
465     unsigned int freq, nchannels;
466     const char *pcm_name = in ? conf.pcm_name_in : conf.pcm_name_out;
467     snd_pcm_uframes_t obt_buffer_size;
468     const char *typ = in ? "ADC" : "DAC";
469     snd_pcm_format_t obtfmt;
470 
471     freq = req->freq;
472     nchannels = req->nchannels;
473     size_in_usec = req->size_in_usec;
474 
475     snd_pcm_hw_params_alloca (&hw_params);
476 
477     err = snd_pcm_open (
478         &handle,
479         pcm_name,
480         in ? SND_PCM_STREAM_CAPTURE : SND_PCM_STREAM_PLAYBACK,
481         SND_PCM_NONBLOCK
482         );
483     if (err < 0) {
484         alsa_logerr2 (err, typ, "Failed to open `%s':\n", pcm_name);
485         return -1;
486     }
487 
488     err = snd_pcm_hw_params_any (handle, hw_params);
489     if (err < 0) {
490         alsa_logerr2 (err, typ, "Failed to initialize hardware parameters\n");
491         goto err;
492     }
493 
494     err = snd_pcm_hw_params_set_access (
495         handle,
496         hw_params,
497         SND_PCM_ACCESS_RW_INTERLEAVED
498         );
499     if (err < 0) {
500         alsa_logerr2 (err, typ, "Failed to set access type\n");
501         goto err;
502     }
503 
504     err = snd_pcm_hw_params_set_format (handle, hw_params, req->fmt);
505     if (err < 0 && conf.verbose) {
506         alsa_logerr2 (err, typ, "Failed to set format %d\n", req->fmt);
507     }
508 
509     err = snd_pcm_hw_params_set_rate_near (handle, hw_params, &freq, 0);
510     if (err < 0) {
511         alsa_logerr2 (err, typ, "Failed to set frequency %d\n", req->freq);
512         goto err;
513     }
514 
515     err = snd_pcm_hw_params_set_channels_near (
516         handle,
517         hw_params,
518         &nchannels
519         );
520     if (err < 0) {
521         alsa_logerr2 (err, typ, "Failed to set number of channels %d\n",
522                       req->nchannels);
523         goto err;
524     }
525 
526     if (nchannels != 1 && nchannels != 2) {
527         alsa_logerr2 (err, typ,
528                       "Can not handle obtained number of channels %d\n",
529                       nchannels);
530         goto err;
531     }
532 
533     if (req->buffer_size) {
534         unsigned long obt;
535 
536         if (size_in_usec) {
537             int dir = 0;
538             unsigned int btime = req->buffer_size;
539 
540             err = snd_pcm_hw_params_set_buffer_time_near (
541                 handle,
542                 hw_params,
543                 &btime,
544                 &dir
545                 );
546             obt = btime;
547         }
548         else {
549             snd_pcm_uframes_t bsize = req->buffer_size;
550 
551             err = snd_pcm_hw_params_set_buffer_size_near (
552                 handle,
553                 hw_params,
554                 &bsize
555                 );
556             obt = bsize;
557         }
558         if (err < 0) {
559             alsa_logerr2 (err, typ, "Failed to set buffer %s to %d\n",
560                           size_in_usec ? "time" : "size", req->buffer_size);
561             goto err;
562         }
563 
564         if ((req->override_mask & 2) && (obt - req->buffer_size))
565             dolog ("Requested buffer %s %u was rejected, using %lu\n",
566                    size_in_usec ? "time" : "size", req->buffer_size, obt);
567     }
568 
569     if (req->period_size) {
570         unsigned long obt;
571 
572         if (size_in_usec) {
573             int dir = 0;
574             unsigned int ptime = req->period_size;
575 
576             err = snd_pcm_hw_params_set_period_time_near (
577                 handle,
578                 hw_params,
579                 &ptime,
580                 &dir
581                 );
582             obt = ptime;
583         }
584         else {
585             int dir = 0;
586             snd_pcm_uframes_t psize = req->period_size;
587 
588             err = snd_pcm_hw_params_set_period_size_near (
589                 handle,
590                 hw_params,
591                 &psize,
592                 &dir
593                 );
594             obt = psize;
595         }
596 
597         if (err < 0) {
598             alsa_logerr2 (err, typ, "Failed to set period %s to %d\n",
599                           size_in_usec ? "time" : "size", req->period_size);
600             goto err;
601         }
602 
603         if (((req->override_mask & 1) && (obt - req->period_size)))
604             dolog ("Requested period %s %u was rejected, using %lu\n",
605                    size_in_usec ? "time" : "size", req->period_size, obt);
606     }
607 
608     err = snd_pcm_hw_params (handle, hw_params);
609     if (err < 0) {
610         alsa_logerr2 (err, typ, "Failed to apply audio parameters\n");
611         goto err;
612     }
613 
614     err = snd_pcm_hw_params_get_buffer_size (hw_params, &obt_buffer_size);
615     if (err < 0) {
616         alsa_logerr2 (err, typ, "Failed to get buffer size\n");
617         goto err;
618     }
619 
620     err = snd_pcm_hw_params_get_format (hw_params, &obtfmt);
621     if (err < 0) {
622         alsa_logerr2 (err, typ, "Failed to get format\n");
623         goto err;
624     }
625 
626     if (alsa_to_audfmt (obtfmt, &obt->fmt, &obt->endianness)) {
627         dolog ("Invalid format was returned %d\n", obtfmt);
628         goto err;
629     }
630 
631     err = snd_pcm_prepare (handle);
632     if (err < 0) {
633         alsa_logerr2 (err, typ, "Could not prepare handle %p\n", handle);
634         goto err;
635     }
636 
637     if (!in && conf.threshold) {
638         snd_pcm_uframes_t threshold;
639         int bytes_per_sec;
640 
641         bytes_per_sec = freq << (nchannels == 2);
642 
643         switch (obt->fmt) {
644         case AUD_FMT_S8:
645         case AUD_FMT_U8:
646             break;
647 
648         case AUD_FMT_S16:
649         case AUD_FMT_U16:
650             bytes_per_sec <<= 1;
651             break;
652 
653         case AUD_FMT_S32:
654         case AUD_FMT_U32:
655             bytes_per_sec <<= 2;
656             break;
657         }
658 
659         threshold = (conf.threshold * bytes_per_sec) / 1000;
660         alsa_set_threshold (handle, threshold);
661     }
662 
663     obt->nchannels = nchannels;
664     obt->freq = freq;
665     obt->samples = obt_buffer_size;
666 
667     *handlep = handle;
668 
669     if (conf.verbose &&
670         (obtfmt != req->fmt ||
671          obt->nchannels != req->nchannels ||
672          obt->freq != req->freq)) {
673         dolog ("Audio parameters for %s\n", typ);
674         alsa_dump_info (req, obt, obtfmt);
675     }
676 
677 #ifdef DEBUG
678     alsa_dump_info (req, obt, obtfmt);
679 #endif
680     return 0;
681 
682  err:
683     alsa_anal_close1 (&handle);
684     return -1;
685 }
686 
687 static snd_pcm_sframes_t alsa_get_avail (snd_pcm_t *handle)
688 {
689     snd_pcm_sframes_t avail;
690 
691     avail = snd_pcm_avail_update (handle);
692     if (avail < 0) {
693         if (avail == -EPIPE) {
694             if (!alsa_recover (handle)) {
695                 avail = snd_pcm_avail_update (handle);
696             }
697         }
698 
699         if (avail < 0) {
700             alsa_logerr (avail,
701                          "Could not obtain number of available frames\n");
702             return -1;
703         }
704     }
705 
706     return avail;
707 }
708 
709 static void alsa_write_pending (ALSAVoiceOut *alsa)
710 {
711     HWVoiceOut *hw = &alsa->hw;
712 
713     while (alsa->pending) {
714         int left_till_end_samples = hw->samples - alsa->wpos;
715         int len = audio_MIN (alsa->pending, left_till_end_samples);
716         char *src = advance (alsa->pcm_buf, alsa->wpos << hw->info.shift);
717 
718         while (len) {
719             snd_pcm_sframes_t written;
720 
721             written = snd_pcm_writei (alsa->handle, src, len);
722 
723             if (written <= 0) {
724                 switch (written) {
725                 case 0:
726                     if (conf.verbose) {
727                         dolog ("Failed to write %d frames (wrote zero)\n", len);
728                     }
729                     return;
730 
731                 case -EPIPE:
732                     if (alsa_recover (alsa->handle)) {
733                         alsa_logerr (written, "Failed to write %d frames\n",
734                                      len);
735                         return;
736                     }
737                     if (conf.verbose) {
738                         dolog ("Recovering from playback xrun\n");
739                     }
740                     continue;
741 
742                 case -ESTRPIPE:
743                     /* stream is suspended and waiting for an
744                        application recovery */
745                     if (alsa_resume (alsa->handle)) {
746                         alsa_logerr (written, "Failed to write %d frames\n",
747                                      len);
748                         return;
749                     }
750                     if (conf.verbose) {
751                         dolog ("Resuming suspended output stream\n");
752                     }
753                     continue;
754 
755                 case -EAGAIN:
756                     return;
757 
758                 default:
759                     alsa_logerr (written, "Failed to write %d frames from %p\n",
760                                  len, src);
761                     return;
762                 }
763             }
764 
765             alsa->wpos = (alsa->wpos + written) % hw->samples;
766             alsa->pending -= written;
767             len -= written;
768         }
769     }
770 }
771 
772 static int alsa_run_out (HWVoiceOut *hw, int live)
773 {
774     ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
775     int decr;
776     snd_pcm_sframes_t avail;
777 
778     avail = alsa_get_avail (alsa->handle);
779     if (avail < 0) {
780         dolog ("Could not get number of available playback frames\n");
781         return 0;
782     }
783 
784     decr = audio_MIN (live, avail);
785     decr = audio_pcm_hw_clip_out (hw, alsa->pcm_buf, decr, alsa->pending);
786     alsa->pending += decr;
787     alsa_write_pending (alsa);
788     return decr;
789 }
790 
791 static void alsa_fini_out (HWVoiceOut *hw)
792 {
793     ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
794 
795     ldebug ("alsa_fini\n");
796     alsa_anal_close (&alsa->handle, &alsa->pollhlp);
797 
798     if (alsa->pcm_buf) {
799         qemu_free (alsa->pcm_buf);
800         alsa->pcm_buf = NULL;
801     }
802 }
803 
804 static int alsa_init_out (HWVoiceOut *hw, struct audsettings *as)
805 {
806     ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
807     struct alsa_params_req req;
808     struct alsa_params_obt obt;
809     snd_pcm_t *handle;
810     struct audsettings obt_as;
811 
812     req.fmt = aud_to_alsafmt (as->fmt);
813     req.freq = as->freq;
814     req.nchannels = as->nchannels;
815     req.period_size = conf.period_size_out;
816     req.buffer_size = conf.buffer_size_out;
817     req.size_in_usec = conf.size_in_usec_out;
818     req.override_mask =
819         (conf.period_size_out_overridden ? 1 : 0) |
820         (conf.buffer_size_out_overridden ? 2 : 0);
821 
822     if (alsa_open (0, &req, &obt, &handle)) {
823         return -1;
824     }
825 
826     obt_as.freq = obt.freq;
827     obt_as.nchannels = obt.nchannels;
828     obt_as.fmt = obt.fmt;
829     obt_as.endianness = obt.endianness;
830 
831     audio_pcm_init_info (&hw->info, &obt_as);
832     hw->samples = obt.samples;
833 
834     alsa->pcm_buf = audio_calloc (AUDIO_FUNC, obt.samples, 1 << hw->info.shift);
835     if (!alsa->pcm_buf) {
836         dolog ("Could not allocate DAC buffer (%d samples, each %d bytes)\n",
837                hw->samples, 1 << hw->info.shift);
838         alsa_anal_close1 (&handle);
839         return -1;
840     }
841 
842     alsa->handle = handle;
843     return 0;
844 }
845 
846 #define VOICE_CTL_PAUSE 0
847 #define VOICE_CTL_PREPARE 1
848 #define VOICE_CTL_START 2
849 
850 static int alsa_voice_ctl (snd_pcm_t *handle, const char *typ, int ctl)
851 {
852     int err;
853 
854     if (ctl == VOICE_CTL_PAUSE) {
855         err = snd_pcm_drop (handle);
856         if (err < 0) {
857             alsa_logerr (err, "Could not stop %s\n", typ);
858             return -1;
859         }
860     }
861     else {
862         err = snd_pcm_prepare (handle);
863         if (err < 0) {
864             alsa_logerr (err, "Could not prepare handle for %s\n", typ);
865             return -1;
866         }
867         if (ctl == VOICE_CTL_START) {
868             err = snd_pcm_start(handle);
869             if (err < 0) {
870                 alsa_logerr (err, "Could not start handle for %s\n", typ);
871                 return -1;
872             }
873         }
874     }
875 
876     return 0;
877 }
878 
879 static int alsa_ctl_out (HWVoiceOut *hw, int cmd, ...)
880 {
881     ALSAVoiceOut *alsa = (ALSAVoiceOut *) hw;
882 
883     switch (cmd) {
884     case VOICE_ENABLE:
885         {
886             va_list ap;
887             int poll_mode;
888 
889             va_start (ap, cmd);
890             poll_mode = va_arg (ap, int);
891             va_end (ap);
892 
893             ldebug ("enabling voice\n");
894             if (poll_mode && alsa_poll_out (hw)) {
895                 poll_mode = 0;
896             }
897             hw->poll_mode = poll_mode;
898             return alsa_voice_ctl (alsa->handle, "playback", VOICE_CTL_PREPARE);
899         }
900 
901     case VOICE_DISABLE:
902         ldebug ("disabling voice\n");
903         if (hw->poll_mode) {
904             hw->poll_mode = 0;
905             alsa_fini_poll (&alsa->pollhlp);
906         }
907         return alsa_voice_ctl (alsa->handle, "playback", VOICE_CTL_PAUSE);
908     }
909 
910     return -1;
911 }
912 
913 static int alsa_init_in (HWVoiceIn *hw, struct audsettings *as)
914 {
915     ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
916     struct alsa_params_req req;
917     struct alsa_params_obt obt;
918     snd_pcm_t *handle;
919     struct audsettings obt_as;
920 
921     req.fmt = aud_to_alsafmt (as->fmt);
922     req.freq = as->freq;
923     req.nchannels = as->nchannels;
924     req.period_size = conf.period_size_in;
925     req.buffer_size = conf.buffer_size_in;
926     req.size_in_usec = conf.size_in_usec_in;
927     req.override_mask =
928         (conf.period_size_in_overridden ? 1 : 0) |
929         (conf.buffer_size_in_overridden ? 2 : 0);
930 
931     if (alsa_open (1, &req, &obt, &handle)) {
932         return -1;
933     }
934 
935     obt_as.freq = obt.freq;
936     obt_as.nchannels = obt.nchannels;
937     obt_as.fmt = obt.fmt;
938     obt_as.endianness = obt.endianness;
939 
940     audio_pcm_init_info (&hw->info, &obt_as);
941     hw->samples = obt.samples;
942 
943     alsa->pcm_buf = audio_calloc (AUDIO_FUNC, hw->samples, 1 << hw->info.shift);
944     if (!alsa->pcm_buf) {
945         dolog ("Could not allocate ADC buffer (%d samples, each %d bytes)\n",
946                hw->samples, 1 << hw->info.shift);
947         alsa_anal_close1 (&handle);
948         return -1;
949     }
950 
951     alsa->handle = handle;
952     return 0;
953 }
954 
955 static void alsa_fini_in (HWVoiceIn *hw)
956 {
957     ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
958 
959     alsa_anal_close (&alsa->handle, &alsa->pollhlp);
960 
961     if (alsa->pcm_buf) {
962         qemu_free (alsa->pcm_buf);
963         alsa->pcm_buf = NULL;
964     }
965 }
966 
967 static int alsa_run_in (HWVoiceIn *hw)
968 {
969     ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
970     int hwshift = hw->info.shift;
971     int i;
972     int live = audio_pcm_hw_get_live_in (hw);
973     int dead = hw->samples - live;
974     int decr;
975     struct {
976         int add;
977         int len;
978     } bufs[2] = {
979         { .add = hw->wpos, .len = 0 },
980         { .add = 0,        .len = 0 }
981     };
982     snd_pcm_sframes_t avail;
983     snd_pcm_uframes_t read_samples = 0;
984 
985     if (!dead) {
986         return 0;
987     }
988 
989     avail = alsa_get_avail (alsa->handle);
990     if (avail < 0) {
991         dolog ("Could not get number of captured frames\n");
992         return 0;
993     }
994 
995     if (!avail) {
996         snd_pcm_state_t state;
997 
998         state = snd_pcm_state (alsa->handle);
999         switch (state) {
1000         case SND_PCM_STATE_PREPARED:
1001             avail = hw->samples;
1002             break;
1003         case SND_PCM_STATE_SUSPENDED:
1004             /* stream is suspended and waiting for an application recovery */
1005             if (alsa_resume (alsa->handle)) {
1006                 dolog ("Failed to resume suspended input stream\n");
1007                 return 0;
1008             }
1009             if (conf.verbose) {
1010                 dolog ("Resuming suspended input stream\n");
1011             }
1012             break;
1013         default:
1014             if (conf.verbose) {
1015                 dolog ("No frames available and ALSA state is %d\n", state);
1016             }
1017             return 0;
1018         }
1019     }
1020 
1021     decr = audio_MIN (dead, avail);
1022     if (!decr) {
1023         return 0;
1024     }
1025 
1026     if (hw->wpos + decr > hw->samples) {
1027         bufs[0].len = (hw->samples - hw->wpos);
1028         bufs[1].len = (decr - (hw->samples - hw->wpos));
1029     }
1030     else {
1031         bufs[0].len = decr;
1032     }
1033 
1034     for (i = 0; i < 2; ++i) {
1035         void *src;
1036         struct st_sample *dst;
1037         snd_pcm_sframes_t nread;
1038         snd_pcm_uframes_t len;
1039 
1040         len = bufs[i].len;
1041 
1042         src = advance (alsa->pcm_buf, bufs[i].add << hwshift);
1043         dst = hw->conv_buf + bufs[i].add;
1044 
1045         while (len) {
1046             nread = snd_pcm_readi (alsa->handle, src, len);
1047 
1048             if (nread <= 0) {
1049                 switch (nread) {
1050                 case 0:
1051                     if (conf.verbose) {
1052                         dolog ("Failed to read %ld frames (read zero)\n", len);
1053                     }
1054                     goto exit;
1055 
1056                 case -EPIPE:
1057                     if (alsa_recover (alsa->handle)) {
1058                         alsa_logerr (nread, "Failed to read %ld frames\n", len);
1059                         goto exit;
1060                     }
1061                     if (conf.verbose) {
1062                         dolog ("Recovering from capture xrun\n");
1063                     }
1064                     continue;
1065 
1066                 case -EAGAIN:
1067                     goto exit;
1068 
1069                 default:
1070                     alsa_logerr (
1071                         nread,
1072                         "Failed to read %ld frames from %p\n",
1073                         len,
1074                         src
1075                         );
1076                     goto exit;
1077                 }
1078             }
1079 
1080             hw->conv (dst, src, nread, &nominal_volume);
1081 
1082             src = advance (src, nread << hwshift);
1083             dst += nread;
1084 
1085             read_samples += nread;
1086             len -= nread;
1087         }
1088     }
1089 
1090  exit:
1091     hw->wpos = (hw->wpos + read_samples) % hw->samples;
1092     return read_samples;
1093 }
1094 
1095 static int alsa_read (SWVoiceIn *sw, void *buf, int size)
1096 {
1097     return audio_pcm_sw_read (sw, buf, size);
1098 }
1099 
1100 static int alsa_ctl_in (HWVoiceIn *hw, int cmd, ...)
1101 {
1102     ALSAVoiceIn *alsa = (ALSAVoiceIn *) hw;
1103 
1104     switch (cmd) {
1105     case VOICE_ENABLE:
1106         {
1107             va_list ap;
1108             int poll_mode;
1109 
1110             va_start (ap, cmd);
1111             poll_mode = va_arg (ap, int);
1112             va_end (ap);
1113 
1114             ldebug ("enabling voice\n");
1115             if (poll_mode && alsa_poll_in (hw)) {
1116                 poll_mode = 0;
1117             }
1118             hw->poll_mode = poll_mode;
1119 
1120             return alsa_voice_ctl (alsa->handle, "capture", VOICE_CTL_START);
1121         }
1122 
1123     case VOICE_DISABLE:
1124         ldebug ("disabling voice\n");
1125         if (hw->poll_mode) {
1126             hw->poll_mode = 0;
1127             alsa_fini_poll (&alsa->pollhlp);
1128         }
1129         return alsa_voice_ctl (alsa->handle, "capture", VOICE_CTL_PAUSE);
1130     }
1131 
1132     return -1;
1133 }
1134 
1135 static void *alsa_audio_init (void)
1136 {
1137     return &conf;
1138 }
1139 
1140 static void alsa_audio_fini (void *opaque)
1141 {
1142     (void) opaque;
1143 }
1144 
1145 static struct audio_option alsa_options[] = {
1146     {
1147         .name        = "DAC_SIZE_IN_USEC",
1148         .tag         = AUD_OPT_BOOL,
1149         .valp        = &conf.size_in_usec_out,
1150         .descr       = "DAC period/buffer size in microseconds (otherwise in frames)"
1151     },
1152     {
1153         .name        = "DAC_PERIOD_SIZE",
1154         .tag         = AUD_OPT_INT,
1155         .valp        = &conf.period_size_out,
1156         .descr       = "DAC period size (0 to go with system default)",
1157         .overriddenp = &conf.period_size_out_overridden
1158     },
1159     {
1160         .name        = "DAC_BUFFER_SIZE",
1161         .tag         = AUD_OPT_INT,
1162         .valp        = &conf.buffer_size_out,
1163         .descr       = "DAC buffer size (0 to go with system default)",
1164         .overriddenp = &conf.buffer_size_out_overridden
1165     },
1166     {
1167         .name        = "ADC_SIZE_IN_USEC",
1168         .tag         = AUD_OPT_BOOL,
1169         .valp        = &conf.size_in_usec_in,
1170         .descr       =
1171         "ADC period/buffer size in microseconds (otherwise in frames)"
1172     },
1173     {
1174         .name        = "ADC_PERIOD_SIZE",
1175         .tag         = AUD_OPT_INT,
1176         .valp        = &conf.period_size_in,
1177         .descr       = "ADC period size (0 to go with system default)",
1178         .overriddenp = &conf.period_size_in_overridden
1179     },
1180     {
1181         .name        = "ADC_BUFFER_SIZE",
1182         .tag         = AUD_OPT_INT,
1183         .valp        = &conf.buffer_size_in,
1184         .descr       = "ADC buffer size (0 to go with system default)",
1185         .overriddenp = &conf.buffer_size_in_overridden
1186     },
1187     {
1188         .name        = "THRESHOLD",
1189         .tag         = AUD_OPT_INT,
1190         .valp        = &conf.threshold,
1191         .descr       = "(undocumented)"
1192     },
1193     {
1194         .name        = "DAC_DEV",
1195         .tag         = AUD_OPT_STR,
1196         .valp        = &conf.pcm_name_out,
1197         .descr       = "DAC device name (for instance dmix)"
1198     },
1199     {
1200         .name        = "ADC_DEV",
1201         .tag         = AUD_OPT_STR,
1202         .valp        = &conf.pcm_name_in,
1203         .descr       = "ADC device name"
1204     },
1205     {
1206         .name        = "VERBOSE",
1207         .tag         = AUD_OPT_BOOL,
1208         .valp        = &conf.verbose,
1209         .descr       = "Behave in a more verbose way"
1210     },
1211     { /* End of list */ }
1212 };
1213 
1214 static struct audio_pcm_ops alsa_pcm_ops = {
1215     .init_out = alsa_init_out,
1216     .fini_out = alsa_fini_out,
1217     .run_out  = alsa_run_out,
1218     .write    = alsa_write,
1219     .ctl_out  = alsa_ctl_out,
1220 
1221     .init_in  = alsa_init_in,
1222     .fini_in  = alsa_fini_in,
1223     .run_in   = alsa_run_in,
1224     .read     = alsa_read,
1225     .ctl_in   = alsa_ctl_in,
1226 };
1227 
1228 struct audio_driver alsa_audio_driver = {
1229     .name           = "alsa",
1230     .descr          = "ALSA http://www.alsa-project.org",
1231     .options        = alsa_options,
1232     .init           = alsa_audio_init,
1233     .fini           = alsa_audio_fini,
1234     .pcm_ops        = &alsa_pcm_ops,
1235     .can_be_default = 1,
1236     .max_voices_out = INT_MAX,
1237     .max_voices_in  = INT_MAX,
1238     .voice_size_out = sizeof (ALSAVoiceOut),
1239     .voice_size_in  = sizeof (ALSAVoiceIn)
1240 };
1241