xref: /qemu/audio/ossaudio.c (revision 138ca49a)
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 GCC_FMT_ATTR (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 GCC_FMT_ATTR (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 void *oss_get_buffer_out(HWVoiceOut *hw, size_t *size)
393 {
394     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
395     if (oss->mmapped) {
396         *size = MIN(oss_get_available_bytes(oss), hw->size_emul - hw->pos_emul);
397         return hw->buf_emul + hw->pos_emul;
398     } else {
399         return audio_generic_get_buffer_out(hw, size);
400     }
401 }
402 
403 static size_t oss_put_buffer_out(HWVoiceOut *hw, void *buf, size_t size)
404 {
405     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
406     if (oss->mmapped) {
407         assert(buf == hw->buf_emul + hw->pos_emul && size < hw->size_emul);
408 
409         hw->pos_emul = (hw->pos_emul + size) % hw->size_emul;
410         return size;
411     } else {
412         return audio_generic_put_buffer_out(hw, buf, size);
413     }
414 }
415 
416 static size_t oss_write(HWVoiceOut *hw, void *buf, size_t len)
417 {
418     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
419     size_t pos;
420 
421     if (oss->mmapped) {
422         size_t total_len;
423         len = MIN(len, oss_get_available_bytes(oss));
424 
425         total_len = len;
426         while (len) {
427             size_t to_copy = MIN(len, hw->size_emul - hw->pos_emul);
428             memcpy(hw->buf_emul + hw->pos_emul, buf, to_copy);
429 
430             hw->pos_emul = (hw->pos_emul + to_copy) % hw->size_emul;
431             buf += to_copy;
432             len -= to_copy;
433         }
434         return total_len;
435     }
436 
437     pos = 0;
438     while (len) {
439         ssize_t bytes_written;
440         void *pcm = advance(buf, pos);
441 
442         bytes_written = write(oss->fd, pcm, len);
443         if (bytes_written < 0) {
444             if (errno != EAGAIN) {
445                 oss_logerr(errno, "failed to write %zu bytes\n",
446                            len);
447             }
448             return pos;
449         }
450 
451         pos += bytes_written;
452         if (bytes_written < len) {
453             break;
454         }
455         len -= bytes_written;
456     }
457     return pos;
458 }
459 
460 static void oss_fini_out (HWVoiceOut *hw)
461 {
462     int err;
463     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
464 
465     ldebug ("oss_fini\n");
466     oss_anal_close (&oss->fd);
467 
468     if (oss->mmapped && hw->buf_emul) {
469         err = munmap(hw->buf_emul, hw->size_emul);
470         if (err) {
471             oss_logerr(errno, "Failed to unmap buffer %p, size %zu\n",
472                        hw->buf_emul, hw->size_emul);
473         }
474         hw->buf_emul = NULL;
475     }
476 }
477 
478 static int oss_init_out(HWVoiceOut *hw, struct audsettings *as,
479                         void *drv_opaque)
480 {
481     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
482     struct oss_params req, obt;
483     int endianness;
484     int err;
485     int fd;
486     AudioFormat effective_fmt;
487     struct audsettings obt_as;
488     Audiodev *dev = drv_opaque;
489     AudiodevOssOptions *oopts = &dev->u.oss;
490 
491     oss->fd = -1;
492 
493     req.fmt = aud_to_ossfmt (as->fmt, as->endianness);
494     req.freq = as->freq;
495     req.nchannels = as->nchannels;
496 
497     if (oss_open(0, &req, as, &obt, &fd, dev)) {
498         return -1;
499     }
500 
501     err = oss_to_audfmt (obt.fmt, &effective_fmt, &endianness);
502     if (err) {
503         oss_anal_close (&fd);
504         return -1;
505     }
506 
507     obt_as.freq = obt.freq;
508     obt_as.nchannels = obt.nchannels;
509     obt_as.fmt = effective_fmt;
510     obt_as.endianness = endianness;
511 
512     audio_pcm_init_info (&hw->info, &obt_as);
513     oss->nfrags = obt.nfrags;
514     oss->fragsize = obt.fragsize;
515 
516     if (obt.nfrags * obt.fragsize % hw->info.bytes_per_frame) {
517         dolog ("warning: Misaligned DAC buffer, size %d, alignment %d\n",
518                obt.nfrags * obt.fragsize, hw->info.bytes_per_frame);
519     }
520 
521     hw->samples = (obt.nfrags * obt.fragsize) / hw->info.bytes_per_frame;
522 
523     oss->mmapped = 0;
524     if (oopts->has_try_mmap && oopts->try_mmap) {
525         hw->size_emul = hw->samples * hw->info.bytes_per_frame;
526         hw->buf_emul = mmap(
527             NULL,
528             hw->size_emul,
529             PROT_READ | PROT_WRITE,
530             MAP_SHARED,
531             fd,
532             0
533             );
534         if (hw->buf_emul == MAP_FAILED) {
535             oss_logerr(errno, "Failed to map %zu bytes of DAC\n",
536                        hw->size_emul);
537             hw->buf_emul = NULL;
538         } else {
539             int err;
540             int trig = 0;
541             if (ioctl (fd, SNDCTL_DSP_SETTRIGGER, &trig) < 0) {
542                 oss_logerr (errno, "SNDCTL_DSP_SETTRIGGER 0 failed\n");
543             } else {
544                 trig = PCM_ENABLE_OUTPUT;
545                 if (ioctl (fd, SNDCTL_DSP_SETTRIGGER, &trig) < 0) {
546                     oss_logerr (
547                         errno,
548                         "SNDCTL_DSP_SETTRIGGER PCM_ENABLE_OUTPUT failed\n"
549                         );
550                 } else {
551                     oss->mmapped = 1;
552                 }
553             }
554 
555             if (!oss->mmapped) {
556                 err = munmap(hw->buf_emul, hw->size_emul);
557                 if (err) {
558                     oss_logerr(errno, "Failed to unmap buffer %p size %zu\n",
559                                hw->buf_emul, hw->size_emul);
560                 }
561                 hw->buf_emul = NULL;
562             }
563         }
564     }
565 
566     oss->fd = fd;
567     oss->dev = dev;
568     return 0;
569 }
570 
571 static void oss_enable_out(HWVoiceOut *hw, bool enable)
572 {
573     int trig;
574     OSSVoiceOut *oss = (OSSVoiceOut *) hw;
575     AudiodevOssPerDirectionOptions *opdo = oss->dev->u.oss.out;
576 
577     if (enable) {
578         hw->poll_mode = opdo->try_poll;
579 
580         ldebug("enabling voice\n");
581         if (hw->poll_mode) {
582             oss_poll_out(hw);
583         }
584 
585         if (!oss->mmapped) {
586             return;
587         }
588 
589         audio_pcm_info_clear_buf(&hw->info, hw->buf_emul, hw->samples);
590         trig = PCM_ENABLE_OUTPUT;
591         if (ioctl(oss->fd, SNDCTL_DSP_SETTRIGGER, &trig) < 0) {
592             oss_logerr(errno,
593                        "SNDCTL_DSP_SETTRIGGER PCM_ENABLE_OUTPUT failed\n");
594             return;
595         }
596     } else {
597         if (hw->poll_mode) {
598             qemu_set_fd_handler (oss->fd, NULL, NULL, NULL);
599             hw->poll_mode = 0;
600         }
601 
602         if (!oss->mmapped) {
603             return;
604         }
605 
606         ldebug ("disabling voice\n");
607         trig = 0;
608         if (ioctl (oss->fd, SNDCTL_DSP_SETTRIGGER, &trig) < 0) {
609             oss_logerr (errno, "SNDCTL_DSP_SETTRIGGER 0 failed\n");
610             return;
611         }
612     }
613 }
614 
615 static int oss_init_in(HWVoiceIn *hw, struct audsettings *as, void *drv_opaque)
616 {
617     OSSVoiceIn *oss = (OSSVoiceIn *) hw;
618     struct oss_params req, obt;
619     int endianness;
620     int err;
621     int fd;
622     AudioFormat effective_fmt;
623     struct audsettings obt_as;
624     Audiodev *dev = drv_opaque;
625 
626     oss->fd = -1;
627 
628     req.fmt = aud_to_ossfmt (as->fmt, as->endianness);
629     req.freq = as->freq;
630     req.nchannels = as->nchannels;
631     if (oss_open(1, &req, as, &obt, &fd, dev)) {
632         return -1;
633     }
634 
635     err = oss_to_audfmt (obt.fmt, &effective_fmt, &endianness);
636     if (err) {
637         oss_anal_close (&fd);
638         return -1;
639     }
640 
641     obt_as.freq = obt.freq;
642     obt_as.nchannels = obt.nchannels;
643     obt_as.fmt = effective_fmt;
644     obt_as.endianness = endianness;
645 
646     audio_pcm_init_info (&hw->info, &obt_as);
647     oss->nfrags = obt.nfrags;
648     oss->fragsize = obt.fragsize;
649 
650     if (obt.nfrags * obt.fragsize % hw->info.bytes_per_frame) {
651         dolog ("warning: Misaligned ADC buffer, size %d, alignment %d\n",
652                obt.nfrags * obt.fragsize, hw->info.bytes_per_frame);
653     }
654 
655     hw->samples = (obt.nfrags * obt.fragsize) / hw->info.bytes_per_frame;
656 
657     oss->fd = fd;
658     oss->dev = dev;
659     return 0;
660 }
661 
662 static void oss_fini_in (HWVoiceIn *hw)
663 {
664     OSSVoiceIn *oss = (OSSVoiceIn *) hw;
665 
666     oss_anal_close (&oss->fd);
667 }
668 
669 static size_t oss_read(HWVoiceIn *hw, void *buf, size_t len)
670 {
671     OSSVoiceIn *oss = (OSSVoiceIn *) hw;
672     size_t pos = 0;
673 
674     while (len) {
675         ssize_t nread;
676 
677         void *dst = advance(buf, pos);
678         nread = read(oss->fd, dst, len);
679 
680         if (nread == -1) {
681             switch (errno) {
682             case EINTR:
683             case EAGAIN:
684                 break;
685             default:
686                 oss_logerr(errno, "Failed to read %zu bytes of audio (to %p)\n",
687                            len, dst);
688                 break;
689             }
690             break;
691         }
692 
693         pos += nread;
694         len -= nread;
695     }
696 
697     return pos;
698 }
699 
700 static void oss_enable_in(HWVoiceIn *hw, bool enable)
701 {
702     OSSVoiceIn *oss = (OSSVoiceIn *) hw;
703     AudiodevOssPerDirectionOptions *opdo = oss->dev->u.oss.out;
704 
705     if (enable) {
706         hw->poll_mode = opdo->try_poll;
707 
708         if (hw->poll_mode) {
709             oss_poll_in(hw);
710         }
711     } else {
712         if (hw->poll_mode) {
713             qemu_set_fd_handler (oss->fd, NULL, NULL, NULL);
714             hw->poll_mode = 0;
715         }
716     }
717 }
718 
719 static void oss_init_per_direction(AudiodevOssPerDirectionOptions *opdo)
720 {
721     if (!opdo->has_try_poll) {
722         opdo->try_poll = true;
723         opdo->has_try_poll = true;
724     }
725 }
726 
727 static void *oss_audio_init(Audiodev *dev)
728 {
729     AudiodevOssOptions *oopts;
730     assert(dev->driver == AUDIODEV_DRIVER_OSS);
731 
732     oopts = &dev->u.oss;
733     oss_init_per_direction(oopts->in);
734     oss_init_per_direction(oopts->out);
735 
736     if (access(oopts->in->has_dev ? oopts->in->dev : "/dev/dsp",
737                R_OK | W_OK) < 0 ||
738         access(oopts->out->has_dev ? oopts->out->dev : "/dev/dsp",
739                R_OK | W_OK) < 0) {
740         return NULL;
741     }
742     return dev;
743 }
744 
745 static void oss_audio_fini (void *opaque)
746 {
747 }
748 
749 static struct audio_pcm_ops oss_pcm_ops = {
750     .init_out = oss_init_out,
751     .fini_out = oss_fini_out,
752     .write    = oss_write,
753     .run_buffer_out = oss_run_buffer_out,
754     .get_buffer_out = oss_get_buffer_out,
755     .put_buffer_out = oss_put_buffer_out,
756     .enable_out = oss_enable_out,
757 
758     .init_in  = oss_init_in,
759     .fini_in  = oss_fini_in,
760     .read     = oss_read,
761     .run_buffer_in = audio_generic_run_buffer_in,
762     .enable_in = oss_enable_in
763 };
764 
765 static struct audio_driver oss_audio_driver = {
766     .name           = "oss",
767     .descr          = "OSS http://www.opensound.com",
768     .init           = oss_audio_init,
769     .fini           = oss_audio_fini,
770     .pcm_ops        = &oss_pcm_ops,
771     .can_be_default = 1,
772     .max_voices_out = INT_MAX,
773     .max_voices_in  = INT_MAX,
774     .voice_size_out = sizeof (OSSVoiceOut),
775     .voice_size_in  = sizeof (OSSVoiceIn)
776 };
777 
778 static void register_audio_oss(void)
779 {
780     audio_driver_register(&oss_audio_driver);
781 }
782 type_init(register_audio_oss);
783