xref: /openbmc/qemu/audio/ossaudio.c (revision d695918f)
1 /*
2  * QEMU OSS audio driver
3  *
4  * Copyright (c) 2003-2005 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 
25 #include "qemu/osdep.h"
26 #include <sys/ioctl.h>
27 #include <sys/soundcard.h>
28 #include "qemu/main-loop.h"
29 #include "qemu/module.h"
30 #include "qemu/host-utils.h"
31 #include "audio.h"
32 #include "trace.h"
33 
34 #define AUDIO_CAP "oss"
35 #include "audio_int.h"
36 
37 #if defined OSS_GETVERSION && defined SNDCTL_DSP_POLICY
38 #define USE_DSP_POLICY
39 #endif
40 
41 typedef struct OSSVoiceOut {
42     HWVoiceOut hw;
43     int fd;
44     int nfrags;
45     int fragsize;
46     int mmapped;
47     Audiodev *dev;
48 } OSSVoiceOut;
49 
50 typedef struct OSSVoiceIn {
51     HWVoiceIn hw;
52     int fd;
53     int nfrags;
54     int fragsize;
55     Audiodev *dev;
56 } OSSVoiceIn;
57 
58 struct oss_params {
59     int freq;
60     int fmt;
61     int nchannels;
62     int nfrags;
63     int fragsize;
64 };
65 
66 static void G_GNUC_PRINTF (2, 3) oss_logerr (int err, const char *fmt, ...)
67 {
68     va_list ap;
69 
70     va_start (ap, fmt);
71     AUD_vlog (AUDIO_CAP, fmt, ap);
72     va_end (ap);
73 
74     AUD_log (AUDIO_CAP, "Reason: %s\n", strerror (err));
75 }
76 
77 static void G_GNUC_PRINTF (3, 4) oss_logerr2 (
78     int err,
79     const char *typ,
80     const char *fmt,
81     ...
82     )
83 {
84     va_list ap;
85 
86     AUD_log (AUDIO_CAP, "Could not initialize %s\n", typ);
87 
88     va_start (ap, fmt);
89     AUD_vlog (AUDIO_CAP, fmt, ap);
90     va_end (ap);
91 
92     AUD_log (AUDIO_CAP, "Reason: %s\n", strerror (err));
93 }
94 
95 static void oss_anal_close (int *fdp)
96 {
97     int err;
98 
99     qemu_set_fd_handler (*fdp, NULL, NULL, NULL);
100     err = close (*fdp);
101     if (err) {
102         oss_logerr (errno, "Failed to close file(fd=%d)\n", *fdp);
103     }
104     *fdp = -1;
105 }
106 
107 static void oss_helper_poll_out (void *opaque)
108 {
109     AudioState *s = opaque;
110     audio_run(s, "oss_poll_out");
111 }
112 
113 static void oss_helper_poll_in (void *opaque)
114 {
115     AudioState *s = opaque;
116     audio_run(s, "oss_poll_in");
117 }
118 
119 static void oss_poll_out (HWVoiceOut *hw)
120 {
121     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
122 
123     qemu_set_fd_handler(oss->fd, NULL, oss_helper_poll_out, hw->s);
124 }
125 
126 static void oss_poll_in (HWVoiceIn *hw)
127 {
128     OSSVoiceIn *oss = (OSSVoiceIn *) hw;
129 
130     qemu_set_fd_handler(oss->fd, oss_helper_poll_in, NULL, hw->s);
131 }
132 
133 static int aud_to_ossfmt (AudioFormat fmt, int endianness)
134 {
135     switch (fmt) {
136     case AUDIO_FORMAT_S8:
137         return AFMT_S8;
138 
139     case AUDIO_FORMAT_U8:
140         return AFMT_U8;
141 
142     case AUDIO_FORMAT_S16:
143         if (endianness) {
144             return AFMT_S16_BE;
145         } else {
146             return AFMT_S16_LE;
147         }
148 
149     case AUDIO_FORMAT_U16:
150         if (endianness) {
151             return AFMT_U16_BE;
152         } else {
153             return AFMT_U16_LE;
154         }
155 
156     default:
157         dolog ("Internal logic error: Bad audio format %d\n", fmt);
158 #ifdef DEBUG_AUDIO
159         abort ();
160 #endif
161         return AFMT_U8;
162     }
163 }
164 
165 static int oss_to_audfmt (int ossfmt, AudioFormat *fmt, int *endianness)
166 {
167     switch (ossfmt) {
168     case AFMT_S8:
169         *endianness = 0;
170         *fmt = AUDIO_FORMAT_S8;
171         break;
172 
173     case AFMT_U8:
174         *endianness = 0;
175         *fmt = AUDIO_FORMAT_U8;
176         break;
177 
178     case AFMT_S16_LE:
179         *endianness = 0;
180         *fmt = AUDIO_FORMAT_S16;
181         break;
182 
183     case AFMT_U16_LE:
184         *endianness = 0;
185         *fmt = AUDIO_FORMAT_U16;
186         break;
187 
188     case AFMT_S16_BE:
189         *endianness = 1;
190         *fmt = AUDIO_FORMAT_S16;
191         break;
192 
193     case AFMT_U16_BE:
194         *endianness = 1;
195         *fmt = AUDIO_FORMAT_U16;
196         break;
197 
198     default:
199         dolog ("Unrecognized audio format %d\n", ossfmt);
200         return -1;
201     }
202 
203     return 0;
204 }
205 
206 #if defined DEBUG_MISMATCHES || defined DEBUG
207 static void oss_dump_info (struct oss_params *req, struct oss_params *obt)
208 {
209     dolog ("parameter | requested value | obtained value\n");
210     dolog ("format    |      %10d |     %10d\n", req->fmt, obt->fmt);
211     dolog ("channels  |      %10d |     %10d\n",
212            req->nchannels, obt->nchannels);
213     dolog ("frequency |      %10d |     %10d\n", req->freq, obt->freq);
214     dolog ("nfrags    |      %10d |     %10d\n", req->nfrags, obt->nfrags);
215     dolog ("fragsize  |      %10d |     %10d\n",
216            req->fragsize, obt->fragsize);
217 }
218 #endif
219 
220 #ifdef USE_DSP_POLICY
221 static int oss_get_version (int fd, int *version, const char *typ)
222 {
223     if (ioctl (fd, OSS_GETVERSION, &version)) {
224 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
225         /*
226          * Looks like atm (20100109) FreeBSD knows OSS_GETVERSION
227          * since 7.x, but currently only on the mixer device (or in
228          * the Linuxolator), and in the native version that part of
229          * the code is in fact never reached so the ioctl fails anyway.
230          * Until this is fixed, just check the errno and if its what
231          * FreeBSD's sound drivers return atm assume they are new enough.
232          */
233         if (errno == EINVAL) {
234             *version = 0x040000;
235             return 0;
236         }
237 #endif
238         oss_logerr2 (errno, typ, "Failed to get OSS version\n");
239         return -1;
240     }
241     return 0;
242 }
243 #endif
244 
245 static int oss_open(int in, struct oss_params *req, audsettings *as,
246                     struct oss_params *obt, int *pfd, Audiodev *dev)
247 {
248     AudiodevOssOptions *oopts = &dev->u.oss;
249     AudiodevOssPerDirectionOptions *opdo = in ? oopts->in : oopts->out;
250     int fd;
251     int oflags = (oopts->has_exclusive && oopts->exclusive) ? O_EXCL : 0;
252     audio_buf_info abinfo;
253     int fmt, freq, nchannels;
254     int setfragment = 1;
255     const char *dspname = opdo->has_dev ? opdo->dev : "/dev/dsp";
256     const char *typ = in ? "ADC" : "DAC";
257 #ifdef USE_DSP_POLICY
258     int policy = oopts->has_dsp_policy ? oopts->dsp_policy : 5;
259 #endif
260 
261     /* Kludge needed to have working mmap on Linux */
262     oflags |= (oopts->has_try_mmap && oopts->try_mmap) ?
263         O_RDWR : (in ? O_RDONLY : O_WRONLY);
264 
265     fd = open (dspname, oflags | O_NONBLOCK);
266     if (-1 == fd) {
267         oss_logerr2 (errno, typ, "Failed to open `%s'\n", dspname);
268         return -1;
269     }
270 
271     freq = req->freq;
272     nchannels = req->nchannels;
273     fmt = req->fmt;
274     req->nfrags = opdo->has_buffer_count ? opdo->buffer_count : 4;
275     req->fragsize = audio_buffer_bytes(
276         qapi_AudiodevOssPerDirectionOptions_base(opdo), as, 23220);
277 
278     if (ioctl (fd, SNDCTL_DSP_SAMPLESIZE, &fmt)) {
279         oss_logerr2 (errno, typ, "Failed to set sample size %d\n", req->fmt);
280         goto err;
281     }
282 
283     if (ioctl (fd, SNDCTL_DSP_CHANNELS, &nchannels)) {
284         oss_logerr2 (errno, typ, "Failed to set number of channels %d\n",
285                      req->nchannels);
286         goto err;
287     }
288 
289     if (ioctl (fd, SNDCTL_DSP_SPEED, &freq)) {
290         oss_logerr2 (errno, typ, "Failed to set frequency %d\n", req->freq);
291         goto err;
292     }
293 
294     if (ioctl (fd, SNDCTL_DSP_NONBLOCK, NULL)) {
295         oss_logerr2 (errno, typ, "Failed to set non-blocking mode\n");
296         goto err;
297     }
298 
299 #ifdef USE_DSP_POLICY
300     if (policy >= 0) {
301         int version;
302 
303         if (!oss_get_version (fd, &version, typ)) {
304             trace_oss_version(version);
305 
306             if (version >= 0x040000) {
307                 int policy2 = policy;
308                 if (ioctl(fd, SNDCTL_DSP_POLICY, &policy2)) {
309                     oss_logerr2 (errno, typ,
310                                  "Failed to set timing policy to %d\n",
311                                  policy);
312                     goto err;
313                 }
314                 setfragment = 0;
315             }
316         }
317     }
318 #endif
319 
320     if (setfragment) {
321         int mmmmssss = (req->nfrags << 16) | ctz32 (req->fragsize);
322         if (ioctl (fd, SNDCTL_DSP_SETFRAGMENT, &mmmmssss)) {
323             oss_logerr2 (errno, typ, "Failed to set buffer length (%d, %d)\n",
324                          req->nfrags, req->fragsize);
325             goto err;
326         }
327     }
328 
329     if (ioctl (fd, in ? SNDCTL_DSP_GETISPACE : SNDCTL_DSP_GETOSPACE, &abinfo)) {
330         oss_logerr2 (errno, typ, "Failed to get buffer length\n");
331         goto err;
332     }
333 
334     if (!abinfo.fragstotal || !abinfo.fragsize) {
335         AUD_log (AUDIO_CAP, "Returned bogus buffer information(%d, %d) for %s\n",
336                  abinfo.fragstotal, abinfo.fragsize, typ);
337         goto err;
338     }
339 
340     obt->fmt = fmt;
341     obt->nchannels = nchannels;
342     obt->freq = freq;
343     obt->nfrags = abinfo.fragstotal;
344     obt->fragsize = abinfo.fragsize;
345     *pfd = fd;
346 
347 #ifdef DEBUG_MISMATCHES
348     if ((req->fmt != obt->fmt) ||
349         (req->nchannels != obt->nchannels) ||
350         (req->freq != obt->freq) ||
351         (req->fragsize != obt->fragsize) ||
352         (req->nfrags != obt->nfrags)) {
353         dolog ("Audio parameters mismatch\n");
354         oss_dump_info (req, obt);
355     }
356 #endif
357 
358 #ifdef DEBUG
359     oss_dump_info (req, obt);
360 #endif
361     return 0;
362 
363  err:
364     oss_anal_close (&fd);
365     return -1;
366 }
367 
368 static size_t oss_get_available_bytes(OSSVoiceOut *oss)
369 {
370     int err;
371     struct count_info cntinfo;
372     assert(oss->mmapped);
373 
374     err = ioctl(oss->fd, SNDCTL_DSP_GETOPTR, &cntinfo);
375     if (err < 0) {
376         oss_logerr(errno, "SNDCTL_DSP_GETOPTR failed\n");
377         return 0;
378     }
379 
380     return audio_ring_dist(cntinfo.ptr, oss->hw.pos_emul, oss->hw.size_emul);
381 }
382 
383 static void oss_run_buffer_out(HWVoiceOut *hw)
384 {
385     OSSVoiceOut *oss = (OSSVoiceOut *)hw;
386 
387     if (!oss->mmapped) {
388         audio_generic_run_buffer_out(hw);
389     }
390 }
391 
392 static size_t oss_buffer_get_free(HWVoiceOut *hw)
393 {
394     OSSVoiceOut *oss = (OSSVoiceOut *)hw;
395 
396     if (oss->mmapped) {
397         return oss_get_available_bytes(oss);
398     } else {
399         return audio_generic_buffer_get_free(hw);
400     }
401 }
402 
403 static void *oss_get_buffer_out(HWVoiceOut *hw, size_t *size)
404 {
405     OSSVoiceOut *oss = (OSSVoiceOut *)hw;
406 
407     if (oss->mmapped) {
408         *size = hw->size_emul - hw->pos_emul;
409         return hw->buf_emul + hw->pos_emul;
410     } else {
411         return audio_generic_get_buffer_out(hw, size);
412     }
413 }
414 
415 static size_t oss_put_buffer_out(HWVoiceOut *hw, void *buf, size_t size)
416 {
417     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
418     if (oss->mmapped) {
419         assert(buf == hw->buf_emul + hw->pos_emul && size < hw->size_emul);
420 
421         hw->pos_emul = (hw->pos_emul + size) % hw->size_emul;
422         return size;
423     } else {
424         return audio_generic_put_buffer_out(hw, buf, size);
425     }
426 }
427 
428 static size_t oss_write(HWVoiceOut *hw, void *buf, size_t len)
429 {
430     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
431     size_t pos;
432 
433     if (oss->mmapped) {
434         size_t total_len;
435         len = MIN(len, oss_get_available_bytes(oss));
436 
437         total_len = len;
438         while (len) {
439             size_t to_copy = MIN(len, hw->size_emul - hw->pos_emul);
440             memcpy(hw->buf_emul + hw->pos_emul, buf, to_copy);
441 
442             hw->pos_emul = (hw->pos_emul + to_copy) % hw->size_emul;
443             buf += to_copy;
444             len -= to_copy;
445         }
446         return total_len;
447     }
448 
449     pos = 0;
450     while (len) {
451         ssize_t bytes_written;
452         void *pcm = advance(buf, pos);
453 
454         bytes_written = write(oss->fd, pcm, len);
455         if (bytes_written < 0) {
456             if (errno != EAGAIN) {
457                 oss_logerr(errno, "failed to write %zu bytes\n",
458                            len);
459             }
460             return pos;
461         }
462 
463         pos += bytes_written;
464         if (bytes_written < len) {
465             break;
466         }
467         len -= bytes_written;
468     }
469     return pos;
470 }
471 
472 static void oss_fini_out (HWVoiceOut *hw)
473 {
474     int err;
475     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
476 
477     ldebug ("oss_fini\n");
478     oss_anal_close (&oss->fd);
479 
480     if (oss->mmapped && hw->buf_emul) {
481         err = munmap(hw->buf_emul, hw->size_emul);
482         if (err) {
483             oss_logerr(errno, "Failed to unmap buffer %p, size %zu\n",
484                        hw->buf_emul, hw->size_emul);
485         }
486         hw->buf_emul = NULL;
487     }
488 }
489 
490 static int oss_init_out(HWVoiceOut *hw, struct audsettings *as,
491                         void *drv_opaque)
492 {
493     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
494     struct oss_params req, obt;
495     int endianness;
496     int err;
497     int fd;
498     AudioFormat effective_fmt;
499     struct audsettings obt_as;
500     Audiodev *dev = drv_opaque;
501     AudiodevOssOptions *oopts = &dev->u.oss;
502 
503     oss->fd = -1;
504 
505     req.fmt = aud_to_ossfmt (as->fmt, as->endianness);
506     req.freq = as->freq;
507     req.nchannels = as->nchannels;
508 
509     if (oss_open(0, &req, as, &obt, &fd, dev)) {
510         return -1;
511     }
512 
513     err = oss_to_audfmt (obt.fmt, &effective_fmt, &endianness);
514     if (err) {
515         oss_anal_close (&fd);
516         return -1;
517     }
518 
519     obt_as.freq = obt.freq;
520     obt_as.nchannels = obt.nchannels;
521     obt_as.fmt = effective_fmt;
522     obt_as.endianness = endianness;
523 
524     audio_pcm_init_info (&hw->info, &obt_as);
525     oss->nfrags = obt.nfrags;
526     oss->fragsize = obt.fragsize;
527 
528     if (obt.nfrags * obt.fragsize % hw->info.bytes_per_frame) {
529         dolog ("warning: Misaligned DAC buffer, size %d, alignment %d\n",
530                obt.nfrags * obt.fragsize, hw->info.bytes_per_frame);
531     }
532 
533     hw->samples = (obt.nfrags * obt.fragsize) / hw->info.bytes_per_frame;
534 
535     oss->mmapped = 0;
536     if (oopts->has_try_mmap && oopts->try_mmap) {
537         hw->size_emul = hw->samples * hw->info.bytes_per_frame;
538         hw->buf_emul = mmap(
539             NULL,
540             hw->size_emul,
541             PROT_READ | PROT_WRITE,
542             MAP_SHARED,
543             fd,
544             0
545             );
546         if (hw->buf_emul == MAP_FAILED) {
547             oss_logerr(errno, "Failed to map %zu bytes of DAC\n",
548                        hw->size_emul);
549             hw->buf_emul = NULL;
550         } else {
551             int err;
552             int trig = 0;
553             if (ioctl (fd, SNDCTL_DSP_SETTRIGGER, &trig) < 0) {
554                 oss_logerr (errno, "SNDCTL_DSP_SETTRIGGER 0 failed\n");
555             } else {
556                 trig = PCM_ENABLE_OUTPUT;
557                 if (ioctl (fd, SNDCTL_DSP_SETTRIGGER, &trig) < 0) {
558                     oss_logerr (
559                         errno,
560                         "SNDCTL_DSP_SETTRIGGER PCM_ENABLE_OUTPUT failed\n"
561                         );
562                 } else {
563                     oss->mmapped = 1;
564                 }
565             }
566 
567             if (!oss->mmapped) {
568                 err = munmap(hw->buf_emul, hw->size_emul);
569                 if (err) {
570                     oss_logerr(errno, "Failed to unmap buffer %p size %zu\n",
571                                hw->buf_emul, hw->size_emul);
572                 }
573                 hw->buf_emul = NULL;
574             }
575         }
576     }
577 
578     oss->fd = fd;
579     oss->dev = dev;
580     return 0;
581 }
582 
583 static void oss_enable_out(HWVoiceOut *hw, bool enable)
584 {
585     int trig;
586     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
587     AudiodevOssPerDirectionOptions *opdo = oss->dev->u.oss.out;
588 
589     if (enable) {
590         hw->poll_mode = opdo->try_poll;
591 
592         ldebug("enabling voice\n");
593         if (hw->poll_mode) {
594             oss_poll_out(hw);
595         }
596 
597         if (!oss->mmapped) {
598             return;
599         }
600 
601         audio_pcm_info_clear_buf(&hw->info, hw->buf_emul, hw->samples);
602         trig = PCM_ENABLE_OUTPUT;
603         if (ioctl(oss->fd, SNDCTL_DSP_SETTRIGGER, &trig) < 0) {
604             oss_logerr(errno,
605                        "SNDCTL_DSP_SETTRIGGER PCM_ENABLE_OUTPUT failed\n");
606             return;
607         }
608     } else {
609         if (hw->poll_mode) {
610             qemu_set_fd_handler (oss->fd, NULL, NULL, NULL);
611             hw->poll_mode = 0;
612         }
613 
614         if (!oss->mmapped) {
615             return;
616         }
617 
618         ldebug ("disabling voice\n");
619         trig = 0;
620         if (ioctl (oss->fd, SNDCTL_DSP_SETTRIGGER, &trig) < 0) {
621             oss_logerr (errno, "SNDCTL_DSP_SETTRIGGER 0 failed\n");
622             return;
623         }
624     }
625 }
626 
627 static int oss_init_in(HWVoiceIn *hw, struct audsettings *as, void *drv_opaque)
628 {
629     OSSVoiceIn *oss = (OSSVoiceIn *) hw;
630     struct oss_params req, obt;
631     int endianness;
632     int err;
633     int fd;
634     AudioFormat effective_fmt;
635     struct audsettings obt_as;
636     Audiodev *dev = drv_opaque;
637 
638     oss->fd = -1;
639 
640     req.fmt = aud_to_ossfmt (as->fmt, as->endianness);
641     req.freq = as->freq;
642     req.nchannels = as->nchannels;
643     if (oss_open(1, &req, as, &obt, &fd, dev)) {
644         return -1;
645     }
646 
647     err = oss_to_audfmt (obt.fmt, &effective_fmt, &endianness);
648     if (err) {
649         oss_anal_close (&fd);
650         return -1;
651     }
652 
653     obt_as.freq = obt.freq;
654     obt_as.nchannels = obt.nchannels;
655     obt_as.fmt = effective_fmt;
656     obt_as.endianness = endianness;
657 
658     audio_pcm_init_info (&hw->info, &obt_as);
659     oss->nfrags = obt.nfrags;
660     oss->fragsize = obt.fragsize;
661 
662     if (obt.nfrags * obt.fragsize % hw->info.bytes_per_frame) {
663         dolog ("warning: Misaligned ADC buffer, size %d, alignment %d\n",
664                obt.nfrags * obt.fragsize, hw->info.bytes_per_frame);
665     }
666 
667     hw->samples = (obt.nfrags * obt.fragsize) / hw->info.bytes_per_frame;
668 
669     oss->fd = fd;
670     oss->dev = dev;
671     return 0;
672 }
673 
674 static void oss_fini_in (HWVoiceIn *hw)
675 {
676     OSSVoiceIn *oss = (OSSVoiceIn *) hw;
677 
678     oss_anal_close (&oss->fd);
679 }
680 
681 static size_t oss_read(HWVoiceIn *hw, void *buf, size_t len)
682 {
683     OSSVoiceIn *oss = (OSSVoiceIn *) hw;
684     size_t pos = 0;
685 
686     while (len) {
687         ssize_t nread;
688 
689         void *dst = advance(buf, pos);
690         nread = read(oss->fd, dst, len);
691 
692         if (nread == -1) {
693             switch (errno) {
694             case EINTR:
695             case EAGAIN:
696                 break;
697             default:
698                 oss_logerr(errno, "Failed to read %zu bytes of audio (to %p)\n",
699                            len, dst);
700                 break;
701             }
702             break;
703         }
704 
705         pos += nread;
706         len -= nread;
707     }
708 
709     return pos;
710 }
711 
712 static void oss_enable_in(HWVoiceIn *hw, bool enable)
713 {
714     OSSVoiceIn *oss = (OSSVoiceIn *) hw;
715     AudiodevOssPerDirectionOptions *opdo = oss->dev->u.oss.out;
716 
717     if (enable) {
718         hw->poll_mode = opdo->try_poll;
719 
720         if (hw->poll_mode) {
721             oss_poll_in(hw);
722         }
723     } else {
724         if (hw->poll_mode) {
725             qemu_set_fd_handler (oss->fd, NULL, NULL, NULL);
726             hw->poll_mode = 0;
727         }
728     }
729 }
730 
731 static void oss_init_per_direction(AudiodevOssPerDirectionOptions *opdo)
732 {
733     if (!opdo->has_try_poll) {
734         opdo->try_poll = true;
735         opdo->has_try_poll = true;
736     }
737 }
738 
739 static void *oss_audio_init(Audiodev *dev)
740 {
741     AudiodevOssOptions *oopts;
742     assert(dev->driver == AUDIODEV_DRIVER_OSS);
743 
744     oopts = &dev->u.oss;
745     oss_init_per_direction(oopts->in);
746     oss_init_per_direction(oopts->out);
747 
748     if (access(oopts->in->has_dev ? oopts->in->dev : "/dev/dsp",
749                R_OK | W_OK) < 0 ||
750         access(oopts->out->has_dev ? oopts->out->dev : "/dev/dsp",
751                R_OK | W_OK) < 0) {
752         return NULL;
753     }
754     return dev;
755 }
756 
757 static void oss_audio_fini (void *opaque)
758 {
759 }
760 
761 static struct audio_pcm_ops oss_pcm_ops = {
762     .init_out = oss_init_out,
763     .fini_out = oss_fini_out,
764     .write    = oss_write,
765     .buffer_get_free = oss_buffer_get_free,
766     .run_buffer_out = oss_run_buffer_out,
767     .get_buffer_out = oss_get_buffer_out,
768     .put_buffer_out = oss_put_buffer_out,
769     .enable_out = oss_enable_out,
770 
771     .init_in  = oss_init_in,
772     .fini_in  = oss_fini_in,
773     .read     = oss_read,
774     .run_buffer_in = audio_generic_run_buffer_in,
775     .enable_in = oss_enable_in
776 };
777 
778 static struct audio_driver oss_audio_driver = {
779     .name           = "oss",
780     .descr          = "OSS http://www.opensound.com",
781     .init           = oss_audio_init,
782     .fini           = oss_audio_fini,
783     .pcm_ops        = &oss_pcm_ops,
784     .can_be_default = 1,
785     .max_voices_out = INT_MAX,
786     .max_voices_in  = INT_MAX,
787     .voice_size_out = sizeof (OSSVoiceOut),
788     .voice_size_in  = sizeof (OSSVoiceIn)
789 };
790 
791 static void register_audio_oss(void)
792 {
793     audio_driver_register(&oss_audio_driver);
794 }
795 type_init(register_audio_oss);
796