xref: /openbmc/qemu/hw/usb/dev-audio.c (revision 14b61600)
1 /*
2  * QEMU USB audio device
3  *
4  * written by:
5  *  H. Peter Anvin <hpa@linux.intel.com>
6  *  Gerd Hoffmann <kraxel@redhat.com>
7  *
8  * lousely based on usb net device code which is:
9  *
10  * Copyright (c) 2006 Thomas Sailer
11  * Copyright (c) 2008 Andrzej Zaborowski
12  *
13  * Permission is hereby granted, free of charge, to any person obtaining a copy
14  * of this software and associated documentation files (the "Software"), to deal
15  * in the Software without restriction, including without limitation the rights
16  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
17  * copies of the Software, and to permit persons to whom the Software is
18  * furnished to do so, subject to the following conditions:
19  *
20  * The above copyright notice and this permission notice shall be included in
21  * all copies or substantial portions of the Software.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
26  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
28  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
29  * THE SOFTWARE.
30  */
31 
32 #include "qemu-common.h"
33 #include "hw/usb.h"
34 #include "hw/usb/desc.h"
35 #include "hw/hw.h"
36 #include "audio/audio.h"
37 
38 #define USBAUDIO_VENDOR_NUM     0x46f4 /* CRC16() of "QEMU" */
39 #define USBAUDIO_PRODUCT_NUM    0x0002
40 
41 #define DEV_CONFIG_VALUE        1 /* The one and only */
42 
43 /* Descriptor subtypes for AC interfaces */
44 #define DST_AC_HEADER           1
45 #define DST_AC_INPUT_TERMINAL   2
46 #define DST_AC_OUTPUT_TERMINAL  3
47 #define DST_AC_FEATURE_UNIT     6
48 /* Descriptor subtypes for AS interfaces */
49 #define DST_AS_GENERAL          1
50 #define DST_AS_FORMAT_TYPE      2
51 /* Descriptor subtypes for endpoints */
52 #define DST_EP_GENERAL          1
53 
54 enum usb_audio_strings {
55     STRING_NULL,
56     STRING_MANUFACTURER,
57     STRING_PRODUCT,
58     STRING_SERIALNUMBER,
59     STRING_CONFIG,
60     STRING_USBAUDIO_CONTROL,
61     STRING_INPUT_TERMINAL,
62     STRING_FEATURE_UNIT,
63     STRING_OUTPUT_TERMINAL,
64     STRING_NULL_STREAM,
65     STRING_REAL_STREAM,
66 };
67 
68 static const USBDescStrings usb_audio_stringtable = {
69     [STRING_MANUFACTURER]       = "QEMU",
70     [STRING_PRODUCT]            = "QEMU USB Audio",
71     [STRING_SERIALNUMBER]       = "1",
72     [STRING_CONFIG]             = "Audio Configuration",
73     [STRING_USBAUDIO_CONTROL]   = "Audio Device",
74     [STRING_INPUT_TERMINAL]     = "Audio Output Pipe",
75     [STRING_FEATURE_UNIT]       = "Audio Output Volume Control",
76     [STRING_OUTPUT_TERMINAL]    = "Audio Output Terminal",
77     [STRING_NULL_STREAM]        = "Audio Output - Disabled",
78     [STRING_REAL_STREAM]        = "Audio Output - 48 kHz Stereo",
79 };
80 
81 #define U16(x) ((x) & 0xff), (((x) >> 8) & 0xff)
82 #define U24(x) U16(x), (((x) >> 16) & 0xff)
83 #define U32(x) U24(x), (((x) >> 24) & 0xff)
84 
85 /*
86  * A Basic Audio Device uses these specific values
87  */
88 #define USBAUDIO_PACKET_SIZE     192
89 #define USBAUDIO_SAMPLE_RATE     48000
90 #define USBAUDIO_PACKET_INTERVAL 1
91 
92 static const USBDescIface desc_iface[] = {
93     {
94         .bInterfaceNumber              = 0,
95         .bNumEndpoints                 = 0,
96         .bInterfaceClass               = USB_CLASS_AUDIO,
97         .bInterfaceSubClass            = USB_SUBCLASS_AUDIO_CONTROL,
98         .bInterfaceProtocol            = 0x04,
99         .iInterface                    = STRING_USBAUDIO_CONTROL,
100         .ndesc                         = 4,
101         .descs = (USBDescOther[]) {
102             {
103                 /* Headphone Class-Specific AC Interface Header Descriptor */
104                 .data = (uint8_t[]) {
105                     0x09,                       /*  u8  bLength */
106                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
107                     DST_AC_HEADER,              /*  u8  bDescriptorSubtype */
108                     U16(0x0100),                /* u16  bcdADC */
109                     U16(0x2b),                  /* u16  wTotalLength */
110                     0x01,                       /*  u8  bInCollection */
111                     0x01,                       /*  u8  baInterfaceNr */
112                 }
113             },{
114                 /* Generic Stereo Input Terminal ID1 Descriptor */
115                 .data = (uint8_t[]) {
116                     0x0c,                       /*  u8  bLength */
117                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
118                     DST_AC_INPUT_TERMINAL,      /*  u8  bDescriptorSubtype */
119                     0x01,                       /*  u8  bTerminalID */
120                     U16(0x0101),                /* u16  wTerminalType */
121                     0x00,                       /*  u8  bAssocTerminal */
122                     0x02,                       /* u16  bNrChannels */
123                     U16(0x0003),                /* u16  wChannelConfig */
124                     0x00,                       /*  u8  iChannelNames */
125                     STRING_INPUT_TERMINAL,      /*  u8  iTerminal */
126                 }
127             },{
128                 /* Generic Stereo Feature Unit ID2 Descriptor */
129                 .data = (uint8_t[]) {
130                     0x0d,                       /*  u8  bLength */
131                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
132                     DST_AC_FEATURE_UNIT,        /*  u8  bDescriptorSubtype */
133                     0x02,                       /*  u8  bUnitID */
134                     0x01,                       /*  u8  bSourceID */
135                     0x02,                       /*  u8  bControlSize */
136                     U16(0x0001),                /* u16  bmaControls(0) */
137                     U16(0x0002),                /* u16  bmaControls(1) */
138                     U16(0x0002),                /* u16  bmaControls(2) */
139                     STRING_FEATURE_UNIT,        /*  u8  iFeature */
140                 }
141             },{
142                 /* Headphone Ouptut Terminal ID3 Descriptor */
143                 .data = (uint8_t[]) {
144                     0x09,                       /*  u8  bLength */
145                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
146                     DST_AC_OUTPUT_TERMINAL,     /*  u8  bDescriptorSubtype */
147                     0x03,                       /*  u8  bUnitID */
148                     U16(0x0301),                /* u16  wTerminalType (SPK) */
149                     0x00,                       /*  u8  bAssocTerminal */
150                     0x02,                       /*  u8  bSourceID */
151                     STRING_OUTPUT_TERMINAL,     /*  u8  iTerminal */
152                 }
153             }
154         },
155     },{
156         .bInterfaceNumber              = 1,
157         .bAlternateSetting             = 0,
158         .bNumEndpoints                 = 0,
159         .bInterfaceClass               = USB_CLASS_AUDIO,
160         .bInterfaceSubClass            = USB_SUBCLASS_AUDIO_STREAMING,
161         .iInterface                    = STRING_NULL_STREAM,
162     },{
163         .bInterfaceNumber              = 1,
164         .bAlternateSetting             = 1,
165         .bNumEndpoints                 = 1,
166         .bInterfaceClass               = USB_CLASS_AUDIO,
167         .bInterfaceSubClass            = USB_SUBCLASS_AUDIO_STREAMING,
168         .iInterface                    = STRING_REAL_STREAM,
169         .ndesc                         = 2,
170         .descs = (USBDescOther[]) {
171             {
172                 /* Headphone Class-specific AS General Interface Descriptor */
173                 .data = (uint8_t[]) {
174                     0x07,                       /*  u8  bLength */
175                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
176                     DST_AS_GENERAL,             /*  u8  bDescriptorSubtype */
177                     0x01,                       /*  u8  bTerminalLink */
178                     0x00,                       /*  u8  bDelay */
179                     0x01, 0x00,                 /* u16  wFormatTag */
180                 }
181             },{
182                 /* Headphone Type I Format Type Descriptor */
183                 .data = (uint8_t[]) {
184                     0x0b,                       /*  u8  bLength */
185                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
186                     DST_AS_FORMAT_TYPE,         /*  u8  bDescriptorSubtype */
187                     0x01,                       /*  u8  bFormatType */
188                     0x02,                       /*  u8  bNrChannels */
189                     0x02,                       /*  u8  bSubFrameSize */
190                     0x10,                       /*  u8  bBitResolution */
191                     0x01,                       /*  u8  bSamFreqType */
192                     U24(USBAUDIO_SAMPLE_RATE),  /* u24  tSamFreq */
193                 }
194             }
195         },
196         .eps = (USBDescEndpoint[]) {
197             {
198                 .bEndpointAddress      = USB_DIR_OUT | 0x01,
199                 .bmAttributes          = 0x0d,
200                 .wMaxPacketSize        = USBAUDIO_PACKET_SIZE,
201                 .bInterval             = 1,
202                 .is_audio              = 1,
203                 /* Stereo Headphone Class-specific
204                    AS Audio Data Endpoint Descriptor */
205                 .extra = (uint8_t[]) {
206                     0x07,                       /*  u8  bLength */
207                     USB_DT_CS_ENDPOINT,         /*  u8  bDescriptorType */
208                     DST_EP_GENERAL,             /*  u8  bDescriptorSubtype */
209                     0x00,                       /*  u8  bmAttributes */
210                     0x00,                       /*  u8  bLockDelayUnits */
211                     U16(0x0000),                /* u16  wLockDelay */
212                 },
213             },
214         }
215     }
216 };
217 
218 static const USBDescDevice desc_device = {
219     .bcdUSB                        = 0x0100,
220     .bMaxPacketSize0               = 64,
221     .bNumConfigurations            = 1,
222     .confs = (USBDescConfig[]) {
223         {
224             .bNumInterfaces        = 2,
225             .bConfigurationValue   = DEV_CONFIG_VALUE,
226             .iConfiguration        = STRING_CONFIG,
227             .bmAttributes          = USB_CFG_ATT_ONE | USB_CFG_ATT_SELFPOWER,
228             .bMaxPower             = 0x32,
229             .nif = ARRAY_SIZE(desc_iface),
230             .ifs = desc_iface,
231         },
232     },
233 };
234 
235 static const USBDesc desc_audio = {
236     .id = {
237         .idVendor          = USBAUDIO_VENDOR_NUM,
238         .idProduct         = USBAUDIO_PRODUCT_NUM,
239         .bcdDevice         = 0,
240         .iManufacturer     = STRING_MANUFACTURER,
241         .iProduct          = STRING_PRODUCT,
242         .iSerialNumber     = STRING_SERIALNUMBER,
243     },
244     .full = &desc_device,
245     .str  = usb_audio_stringtable,
246 };
247 
248 /*
249  * A USB audio device supports an arbitrary number of alternate
250  * interface settings for each interface.  Each corresponds to a block
251  * diagram of parameterized blocks.  This can thus refer to things like
252  * number of channels, data rates, or in fact completely different
253  * block diagrams.  Alternative setting 0 is always the null block diagram,
254  * which is used by a disabled device.
255  */
256 enum usb_audio_altset {
257     ALTSET_OFF  = 0x00,         /* No endpoint */
258     ALTSET_ON   = 0x01,         /* Single endpoint */
259 };
260 
261 /*
262  * Class-specific control requests
263  */
264 #define CR_SET_CUR      0x01
265 #define CR_GET_CUR      0x81
266 #define CR_SET_MIN      0x02
267 #define CR_GET_MIN      0x82
268 #define CR_SET_MAX      0x03
269 #define CR_GET_MAX      0x83
270 #define CR_SET_RES      0x04
271 #define CR_GET_RES      0x84
272 #define CR_SET_MEM      0x05
273 #define CR_GET_MEM      0x85
274 #define CR_GET_STAT     0xff
275 
276 /*
277  * Feature Unit Control Selectors
278  */
279 #define MUTE_CONTROL                    0x01
280 #define VOLUME_CONTROL                  0x02
281 #define BASS_CONTROL                    0x03
282 #define MID_CONTROL                     0x04
283 #define TREBLE_CONTROL                  0x05
284 #define GRAPHIC_EQUALIZER_CONTROL       0x06
285 #define AUTOMATIC_GAIN_CONTROL          0x07
286 #define DELAY_CONTROL                   0x08
287 #define BASS_BOOST_CONTROL              0x09
288 #define LOUDNESS_CONTROL                0x0a
289 
290 /*
291  * buffering
292  */
293 
294 struct streambuf {
295     uint8_t *data;
296     uint32_t size;
297     uint32_t prod;
298     uint32_t cons;
299 };
300 
301 static void streambuf_init(struct streambuf *buf, uint32_t size)
302 {
303     g_free(buf->data);
304     buf->size = size - (size % USBAUDIO_PACKET_SIZE);
305     buf->data = g_malloc(buf->size);
306     buf->prod = 0;
307     buf->cons = 0;
308 }
309 
310 static void streambuf_fini(struct streambuf *buf)
311 {
312     g_free(buf->data);
313     buf->data = NULL;
314 }
315 
316 static int streambuf_put(struct streambuf *buf, USBPacket *p)
317 {
318     uint32_t free = buf->size - (buf->prod - buf->cons);
319 
320     if (!free) {
321         return 0;
322     }
323     assert(free >= USBAUDIO_PACKET_SIZE);
324     usb_packet_copy(p, buf->data + (buf->prod % buf->size),
325                     USBAUDIO_PACKET_SIZE);
326     buf->prod += USBAUDIO_PACKET_SIZE;
327     return USBAUDIO_PACKET_SIZE;
328 }
329 
330 static uint8_t *streambuf_get(struct streambuf *buf)
331 {
332     uint32_t used = buf->prod - buf->cons;
333     uint8_t *data;
334 
335     if (!used) {
336         return NULL;
337     }
338     assert(used >= USBAUDIO_PACKET_SIZE);
339     data = buf->data + (buf->cons % buf->size);
340     buf->cons += USBAUDIO_PACKET_SIZE;
341     return data;
342 }
343 
344 typedef struct USBAudioState {
345     /* qemu interfaces */
346     USBDevice dev;
347     QEMUSoundCard card;
348 
349     /* state */
350     struct {
351         enum usb_audio_altset altset;
352         struct audsettings as;
353         SWVoiceOut *voice;
354         bool mute;
355         uint8_t vol[2];
356         struct streambuf buf;
357     } out;
358 
359     /* properties */
360     uint32_t debug;
361     uint32_t buffer;
362 } USBAudioState;
363 
364 #define TYPE_USB_AUDIO "usb-audio"
365 #define USB_AUDIO(obj) OBJECT_CHECK(USBAudioState, (obj), TYPE_USB_AUDIO)
366 
367 static void output_callback(void *opaque, int avail)
368 {
369     USBAudioState *s = opaque;
370     uint8_t *data;
371 
372     for (;;) {
373         if (avail < USBAUDIO_PACKET_SIZE) {
374             return;
375         }
376         data = streambuf_get(&s->out.buf);
377         if (!data) {
378             return;
379         }
380         AUD_write(s->out.voice, data, USBAUDIO_PACKET_SIZE);
381         avail -= USBAUDIO_PACKET_SIZE;
382     }
383 }
384 
385 static int usb_audio_set_output_altset(USBAudioState *s, int altset)
386 {
387     switch (altset) {
388     case ALTSET_OFF:
389         streambuf_init(&s->out.buf, s->buffer);
390         AUD_set_active_out(s->out.voice, false);
391         break;
392     case ALTSET_ON:
393         AUD_set_active_out(s->out.voice, true);
394         break;
395     default:
396         return -1;
397     }
398 
399     if (s->debug) {
400         fprintf(stderr, "usb-audio: set interface %d\n", altset);
401     }
402     s->out.altset = altset;
403     return 0;
404 }
405 
406 /*
407  * Note: we arbitrarily map the volume control range onto -inf..+8 dB
408  */
409 #define ATTRIB_ID(cs, attrib, idif)     \
410     (((cs) << 24) | ((attrib) << 16) | (idif))
411 
412 static int usb_audio_get_control(USBAudioState *s, uint8_t attrib,
413                                  uint16_t cscn, uint16_t idif,
414                                  int length, uint8_t *data)
415 {
416     uint8_t cs = cscn >> 8;
417     uint8_t cn = cscn - 1;      /* -1 for the non-present master control */
418     uint32_t aid = ATTRIB_ID(cs, attrib, idif);
419     int ret = USB_RET_STALL;
420 
421     switch (aid) {
422     case ATTRIB_ID(MUTE_CONTROL, CR_GET_CUR, 0x0200):
423         data[0] = s->out.mute;
424         ret = 1;
425         break;
426     case ATTRIB_ID(VOLUME_CONTROL, CR_GET_CUR, 0x0200):
427         if (cn < 2) {
428             uint16_t vol = (s->out.vol[cn] * 0x8800 + 127) / 255 + 0x8000;
429             data[0] = vol;
430             data[1] = vol >> 8;
431             ret = 2;
432         }
433         break;
434     case ATTRIB_ID(VOLUME_CONTROL, CR_GET_MIN, 0x0200):
435         if (cn < 2) {
436             data[0] = 0x01;
437             data[1] = 0x80;
438             ret = 2;
439         }
440         break;
441     case ATTRIB_ID(VOLUME_CONTROL, CR_GET_MAX, 0x0200):
442         if (cn < 2) {
443             data[0] = 0x00;
444             data[1] = 0x08;
445             ret = 2;
446         }
447         break;
448     case ATTRIB_ID(VOLUME_CONTROL, CR_GET_RES, 0x0200):
449         if (cn < 2) {
450             data[0] = 0x88;
451             data[1] = 0x00;
452             ret = 2;
453         }
454         break;
455     }
456 
457     return ret;
458 }
459 static int usb_audio_set_control(USBAudioState *s, uint8_t attrib,
460                                  uint16_t cscn, uint16_t idif,
461                                  int length, uint8_t *data)
462 {
463     uint8_t cs = cscn >> 8;
464     uint8_t cn = cscn - 1;      /* -1 for the non-present master control */
465     uint32_t aid = ATTRIB_ID(cs, attrib, idif);
466     int ret = USB_RET_STALL;
467     bool set_vol = false;
468 
469     switch (aid) {
470     case ATTRIB_ID(MUTE_CONTROL, CR_SET_CUR, 0x0200):
471         s->out.mute = data[0] & 1;
472         set_vol = true;
473         ret = 0;
474         break;
475     case ATTRIB_ID(VOLUME_CONTROL, CR_SET_CUR, 0x0200):
476         if (cn < 2) {
477             uint16_t vol = data[0] + (data[1] << 8);
478 
479             if (s->debug) {
480                 fprintf(stderr, "usb-audio: vol %04x\n", (uint16_t)vol);
481             }
482 
483             vol -= 0x8000;
484             vol = (vol * 255 + 0x4400) / 0x8800;
485             if (vol > 255) {
486                 vol = 255;
487             }
488 
489             s->out.vol[cn] = vol;
490             set_vol = true;
491             ret = 0;
492         }
493         break;
494     }
495 
496     if (set_vol) {
497         if (s->debug) {
498             fprintf(stderr, "usb-audio: mute %d, lvol %3d, rvol %3d\n",
499                     s->out.mute, s->out.vol[0], s->out.vol[1]);
500         }
501         AUD_set_volume_out(s->out.voice, s->out.mute,
502                            s->out.vol[0], s->out.vol[1]);
503     }
504 
505     return ret;
506 }
507 
508 static void usb_audio_handle_control(USBDevice *dev, USBPacket *p,
509                                     int request, int value, int index,
510                                     int length, uint8_t *data)
511 {
512     USBAudioState *s = USB_AUDIO(dev);
513     int ret = 0;
514 
515     if (s->debug) {
516         fprintf(stderr, "usb-audio: control transaction: "
517                 "request 0x%04x value 0x%04x index 0x%04x length 0x%04x\n",
518                 request, value, index, length);
519     }
520 
521     ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
522     if (ret >= 0) {
523         return;
524     }
525 
526     switch (request) {
527     case ClassInterfaceRequest | CR_GET_CUR:
528     case ClassInterfaceRequest | CR_GET_MIN:
529     case ClassInterfaceRequest | CR_GET_MAX:
530     case ClassInterfaceRequest | CR_GET_RES:
531         ret = usb_audio_get_control(s, request & 0xff, value, index,
532                                     length, data);
533         if (ret < 0) {
534             if (s->debug) {
535                 fprintf(stderr, "usb-audio: fail: get control\n");
536             }
537             goto fail;
538         }
539         p->actual_length = ret;
540         break;
541 
542     case ClassInterfaceOutRequest | CR_SET_CUR:
543     case ClassInterfaceOutRequest | CR_SET_MIN:
544     case ClassInterfaceOutRequest | CR_SET_MAX:
545     case ClassInterfaceOutRequest | CR_SET_RES:
546         ret = usb_audio_set_control(s, request & 0xff, value, index,
547                                     length, data);
548         if (ret < 0) {
549             if (s->debug) {
550                 fprintf(stderr, "usb-audio: fail: set control\n");
551             }
552             goto fail;
553         }
554         break;
555 
556     default:
557 fail:
558         if (s->debug) {
559             fprintf(stderr, "usb-audio: failed control transaction: "
560                     "request 0x%04x value 0x%04x index 0x%04x length 0x%04x\n",
561                     request, value, index, length);
562         }
563         p->status = USB_RET_STALL;
564         break;
565     }
566 }
567 
568 static void usb_audio_set_interface(USBDevice *dev, int iface,
569                                     int old, int value)
570 {
571     USBAudioState *s = USB_AUDIO(dev);
572 
573     if (iface == 1) {
574         usb_audio_set_output_altset(s, value);
575     }
576 }
577 
578 static void usb_audio_handle_reset(USBDevice *dev)
579 {
580     USBAudioState *s = USB_AUDIO(dev);
581 
582     if (s->debug) {
583         fprintf(stderr, "usb-audio: reset\n");
584     }
585     usb_audio_set_output_altset(s, ALTSET_OFF);
586 }
587 
588 static void usb_audio_handle_dataout(USBAudioState *s, USBPacket *p)
589 {
590     if (s->out.altset == ALTSET_OFF) {
591         p->status = USB_RET_STALL;
592         return;
593     }
594 
595     streambuf_put(&s->out.buf, p);
596     if (p->actual_length < p->iov.size && s->debug > 1) {
597         fprintf(stderr, "usb-audio: output overrun (%zd bytes)\n",
598                 p->iov.size - p->actual_length);
599     }
600 }
601 
602 static void usb_audio_handle_data(USBDevice *dev, USBPacket *p)
603 {
604     USBAudioState *s = (USBAudioState *) dev;
605 
606     if (p->pid == USB_TOKEN_OUT && p->ep->nr == 1) {
607         usb_audio_handle_dataout(s, p);
608         return;
609     }
610 
611     p->status = USB_RET_STALL;
612     if (s->debug) {
613         fprintf(stderr, "usb-audio: failed data transaction: "
614                         "pid 0x%x ep 0x%x len 0x%zx\n",
615                         p->pid, p->ep->nr, p->iov.size);
616     }
617 }
618 
619 static void usb_audio_handle_destroy(USBDevice *dev)
620 {
621     USBAudioState *s = USB_AUDIO(dev);
622 
623     if (s->debug) {
624         fprintf(stderr, "usb-audio: destroy\n");
625     }
626 
627     usb_audio_set_output_altset(s, ALTSET_OFF);
628     AUD_close_out(&s->card, s->out.voice);
629     AUD_remove_card(&s->card);
630 
631     streambuf_fini(&s->out.buf);
632 }
633 
634 static void usb_audio_realize(USBDevice *dev, Error **errp)
635 {
636     USBAudioState *s = USB_AUDIO(dev);
637 
638     usb_desc_create_serial(dev);
639     usb_desc_init(dev);
640     s->dev.opaque = s;
641     AUD_register_card(TYPE_USB_AUDIO, &s->card);
642 
643     s->out.altset        = ALTSET_OFF;
644     s->out.mute          = false;
645     s->out.vol[0]        = 240; /* 0 dB */
646     s->out.vol[1]        = 240; /* 0 dB */
647     s->out.as.freq       = USBAUDIO_SAMPLE_RATE;
648     s->out.as.nchannels  = 2;
649     s->out.as.fmt        = AUD_FMT_S16;
650     s->out.as.endianness = 0;
651     streambuf_init(&s->out.buf, s->buffer);
652 
653     s->out.voice = AUD_open_out(&s->card, s->out.voice, TYPE_USB_AUDIO,
654                                 s, output_callback, &s->out.as);
655     AUD_set_volume_out(s->out.voice, s->out.mute, s->out.vol[0], s->out.vol[1]);
656     AUD_set_active_out(s->out.voice, 0);
657 }
658 
659 static const VMStateDescription vmstate_usb_audio = {
660     .name = TYPE_USB_AUDIO,
661     .unmigratable = 1,
662 };
663 
664 static Property usb_audio_properties[] = {
665     DEFINE_PROP_UINT32("debug", USBAudioState, debug, 0),
666     DEFINE_PROP_UINT32("buffer", USBAudioState, buffer,
667                        32 * USBAUDIO_PACKET_SIZE),
668     DEFINE_PROP_END_OF_LIST(),
669 };
670 
671 static void usb_audio_class_init(ObjectClass *klass, void *data)
672 {
673     DeviceClass *dc = DEVICE_CLASS(klass);
674     USBDeviceClass *k = USB_DEVICE_CLASS(klass);
675 
676     dc->vmsd          = &vmstate_usb_audio;
677     dc->props         = usb_audio_properties;
678     set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
679     k->product_desc   = "QEMU USB Audio Interface";
680     k->usb_desc       = &desc_audio;
681     k->realize        = usb_audio_realize;
682     k->handle_reset   = usb_audio_handle_reset;
683     k->handle_control = usb_audio_handle_control;
684     k->handle_data    = usb_audio_handle_data;
685     k->handle_destroy = usb_audio_handle_destroy;
686     k->set_interface  = usb_audio_set_interface;
687 }
688 
689 static const TypeInfo usb_audio_info = {
690     .name          = TYPE_USB_AUDIO,
691     .parent        = TYPE_USB_DEVICE,
692     .instance_size = sizeof(USBAudioState),
693     .class_init    = usb_audio_class_init,
694 };
695 
696 static void usb_audio_register_types(void)
697 {
698     type_register_static(&usb_audio_info);
699     usb_legacy_register(TYPE_USB_AUDIO, "audio", NULL);
700 }
701 
702 type_init(usb_audio_register_types)
703