xref: /openbmc/qemu/hw/usb/dev-audio.c (revision d38ea87a)
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/osdep.h"
33 #include "qemu-common.h"
34 #include "hw/usb.h"
35 #include "hw/usb/desc.h"
36 #include "hw/hw.h"
37 #include "audio/audio.h"
38 
39 #define USBAUDIO_VENDOR_NUM     0x46f4 /* CRC16() of "QEMU" */
40 #define USBAUDIO_PRODUCT_NUM    0x0002
41 
42 #define DEV_CONFIG_VALUE        1 /* The one and only */
43 
44 /* Descriptor subtypes for AC interfaces */
45 #define DST_AC_HEADER           1
46 #define DST_AC_INPUT_TERMINAL   2
47 #define DST_AC_OUTPUT_TERMINAL  3
48 #define DST_AC_FEATURE_UNIT     6
49 /* Descriptor subtypes for AS interfaces */
50 #define DST_AS_GENERAL          1
51 #define DST_AS_FORMAT_TYPE      2
52 /* Descriptor subtypes for endpoints */
53 #define DST_EP_GENERAL          1
54 
55 enum usb_audio_strings {
56     STRING_NULL,
57     STRING_MANUFACTURER,
58     STRING_PRODUCT,
59     STRING_SERIALNUMBER,
60     STRING_CONFIG,
61     STRING_USBAUDIO_CONTROL,
62     STRING_INPUT_TERMINAL,
63     STRING_FEATURE_UNIT,
64     STRING_OUTPUT_TERMINAL,
65     STRING_NULL_STREAM,
66     STRING_REAL_STREAM,
67 };
68 
69 static const USBDescStrings usb_audio_stringtable = {
70     [STRING_MANUFACTURER]       = "QEMU",
71     [STRING_PRODUCT]            = "QEMU USB Audio",
72     [STRING_SERIALNUMBER]       = "1",
73     [STRING_CONFIG]             = "Audio Configuration",
74     [STRING_USBAUDIO_CONTROL]   = "Audio Device",
75     [STRING_INPUT_TERMINAL]     = "Audio Output Pipe",
76     [STRING_FEATURE_UNIT]       = "Audio Output Volume Control",
77     [STRING_OUTPUT_TERMINAL]    = "Audio Output Terminal",
78     [STRING_NULL_STREAM]        = "Audio Output - Disabled",
79     [STRING_REAL_STREAM]        = "Audio Output - 48 kHz Stereo",
80 };
81 
82 #define U16(x) ((x) & 0xff), (((x) >> 8) & 0xff)
83 #define U24(x) U16(x), (((x) >> 16) & 0xff)
84 #define U32(x) U24(x), (((x) >> 24) & 0xff)
85 
86 /*
87  * A Basic Audio Device uses these specific values
88  */
89 #define USBAUDIO_PACKET_SIZE     192
90 #define USBAUDIO_SAMPLE_RATE     48000
91 #define USBAUDIO_PACKET_INTERVAL 1
92 
93 static const USBDescIface desc_iface[] = {
94     {
95         .bInterfaceNumber              = 0,
96         .bNumEndpoints                 = 0,
97         .bInterfaceClass               = USB_CLASS_AUDIO,
98         .bInterfaceSubClass            = USB_SUBCLASS_AUDIO_CONTROL,
99         .bInterfaceProtocol            = 0x04,
100         .iInterface                    = STRING_USBAUDIO_CONTROL,
101         .ndesc                         = 4,
102         .descs = (USBDescOther[]) {
103             {
104                 /* Headphone Class-Specific AC Interface Header Descriptor */
105                 .data = (uint8_t[]) {
106                     0x09,                       /*  u8  bLength */
107                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
108                     DST_AC_HEADER,              /*  u8  bDescriptorSubtype */
109                     U16(0x0100),                /* u16  bcdADC */
110                     U16(0x2b),                  /* u16  wTotalLength */
111                     0x01,                       /*  u8  bInCollection */
112                     0x01,                       /*  u8  baInterfaceNr */
113                 }
114             },{
115                 /* Generic Stereo Input Terminal ID1 Descriptor */
116                 .data = (uint8_t[]) {
117                     0x0c,                       /*  u8  bLength */
118                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
119                     DST_AC_INPUT_TERMINAL,      /*  u8  bDescriptorSubtype */
120                     0x01,                       /*  u8  bTerminalID */
121                     U16(0x0101),                /* u16  wTerminalType */
122                     0x00,                       /*  u8  bAssocTerminal */
123                     0x02,                       /* u16  bNrChannels */
124                     U16(0x0003),                /* u16  wChannelConfig */
125                     0x00,                       /*  u8  iChannelNames */
126                     STRING_INPUT_TERMINAL,      /*  u8  iTerminal */
127                 }
128             },{
129                 /* Generic Stereo Feature Unit ID2 Descriptor */
130                 .data = (uint8_t[]) {
131                     0x0d,                       /*  u8  bLength */
132                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
133                     DST_AC_FEATURE_UNIT,        /*  u8  bDescriptorSubtype */
134                     0x02,                       /*  u8  bUnitID */
135                     0x01,                       /*  u8  bSourceID */
136                     0x02,                       /*  u8  bControlSize */
137                     U16(0x0001),                /* u16  bmaControls(0) */
138                     U16(0x0002),                /* u16  bmaControls(1) */
139                     U16(0x0002),                /* u16  bmaControls(2) */
140                     STRING_FEATURE_UNIT,        /*  u8  iFeature */
141                 }
142             },{
143                 /* Headphone Ouptut Terminal ID3 Descriptor */
144                 .data = (uint8_t[]) {
145                     0x09,                       /*  u8  bLength */
146                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
147                     DST_AC_OUTPUT_TERMINAL,     /*  u8  bDescriptorSubtype */
148                     0x03,                       /*  u8  bUnitID */
149                     U16(0x0301),                /* u16  wTerminalType (SPK) */
150                     0x00,                       /*  u8  bAssocTerminal */
151                     0x02,                       /*  u8  bSourceID */
152                     STRING_OUTPUT_TERMINAL,     /*  u8  iTerminal */
153                 }
154             }
155         },
156     },{
157         .bInterfaceNumber              = 1,
158         .bAlternateSetting             = 0,
159         .bNumEndpoints                 = 0,
160         .bInterfaceClass               = USB_CLASS_AUDIO,
161         .bInterfaceSubClass            = USB_SUBCLASS_AUDIO_STREAMING,
162         .iInterface                    = STRING_NULL_STREAM,
163     },{
164         .bInterfaceNumber              = 1,
165         .bAlternateSetting             = 1,
166         .bNumEndpoints                 = 1,
167         .bInterfaceClass               = USB_CLASS_AUDIO,
168         .bInterfaceSubClass            = USB_SUBCLASS_AUDIO_STREAMING,
169         .iInterface                    = STRING_REAL_STREAM,
170         .ndesc                         = 2,
171         .descs = (USBDescOther[]) {
172             {
173                 /* Headphone Class-specific AS General Interface Descriptor */
174                 .data = (uint8_t[]) {
175                     0x07,                       /*  u8  bLength */
176                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
177                     DST_AS_GENERAL,             /*  u8  bDescriptorSubtype */
178                     0x01,                       /*  u8  bTerminalLink */
179                     0x00,                       /*  u8  bDelay */
180                     0x01, 0x00,                 /* u16  wFormatTag */
181                 }
182             },{
183                 /* Headphone Type I Format Type Descriptor */
184                 .data = (uint8_t[]) {
185                     0x0b,                       /*  u8  bLength */
186                     USB_DT_CS_INTERFACE,        /*  u8  bDescriptorType */
187                     DST_AS_FORMAT_TYPE,         /*  u8  bDescriptorSubtype */
188                     0x01,                       /*  u8  bFormatType */
189                     0x02,                       /*  u8  bNrChannels */
190                     0x02,                       /*  u8  bSubFrameSize */
191                     0x10,                       /*  u8  bBitResolution */
192                     0x01,                       /*  u8  bSamFreqType */
193                     U24(USBAUDIO_SAMPLE_RATE),  /* u24  tSamFreq */
194                 }
195             }
196         },
197         .eps = (USBDescEndpoint[]) {
198             {
199                 .bEndpointAddress      = USB_DIR_OUT | 0x01,
200                 .bmAttributes          = 0x0d,
201                 .wMaxPacketSize        = USBAUDIO_PACKET_SIZE,
202                 .bInterval             = 1,
203                 .is_audio              = 1,
204                 /* Stereo Headphone Class-specific
205                    AS Audio Data Endpoint Descriptor */
206                 .extra = (uint8_t[]) {
207                     0x07,                       /*  u8  bLength */
208                     USB_DT_CS_ENDPOINT,         /*  u8  bDescriptorType */
209                     DST_EP_GENERAL,             /*  u8  bDescriptorSubtype */
210                     0x00,                       /*  u8  bmAttributes */
211                     0x00,                       /*  u8  bLockDelayUnits */
212                     U16(0x0000),                /* u16  wLockDelay */
213                 },
214             },
215         }
216     }
217 };
218 
219 static const USBDescDevice desc_device = {
220     .bcdUSB                        = 0x0100,
221     .bMaxPacketSize0               = 64,
222     .bNumConfigurations            = 1,
223     .confs = (USBDescConfig[]) {
224         {
225             .bNumInterfaces        = 2,
226             .bConfigurationValue   = DEV_CONFIG_VALUE,
227             .iConfiguration        = STRING_CONFIG,
228             .bmAttributes          = USB_CFG_ATT_ONE | USB_CFG_ATT_SELFPOWER,
229             .bMaxPower             = 0x32,
230             .nif = ARRAY_SIZE(desc_iface),
231             .ifs = desc_iface,
232         },
233     },
234 };
235 
236 static const USBDesc desc_audio = {
237     .id = {
238         .idVendor          = USBAUDIO_VENDOR_NUM,
239         .idProduct         = USBAUDIO_PRODUCT_NUM,
240         .bcdDevice         = 0,
241         .iManufacturer     = STRING_MANUFACTURER,
242         .iProduct          = STRING_PRODUCT,
243         .iSerialNumber     = STRING_SERIALNUMBER,
244     },
245     .full = &desc_device,
246     .str  = usb_audio_stringtable,
247 };
248 
249 /*
250  * A USB audio device supports an arbitrary number of alternate
251  * interface settings for each interface.  Each corresponds to a block
252  * diagram of parameterized blocks.  This can thus refer to things like
253  * number of channels, data rates, or in fact completely different
254  * block diagrams.  Alternative setting 0 is always the null block diagram,
255  * which is used by a disabled device.
256  */
257 enum usb_audio_altset {
258     ALTSET_OFF  = 0x00,         /* No endpoint */
259     ALTSET_ON   = 0x01,         /* Single endpoint */
260 };
261 
262 /*
263  * Class-specific control requests
264  */
265 #define CR_SET_CUR      0x01
266 #define CR_GET_CUR      0x81
267 #define CR_SET_MIN      0x02
268 #define CR_GET_MIN      0x82
269 #define CR_SET_MAX      0x03
270 #define CR_GET_MAX      0x83
271 #define CR_SET_RES      0x04
272 #define CR_GET_RES      0x84
273 #define CR_SET_MEM      0x05
274 #define CR_GET_MEM      0x85
275 #define CR_GET_STAT     0xff
276 
277 /*
278  * Feature Unit Control Selectors
279  */
280 #define MUTE_CONTROL                    0x01
281 #define VOLUME_CONTROL                  0x02
282 #define BASS_CONTROL                    0x03
283 #define MID_CONTROL                     0x04
284 #define TREBLE_CONTROL                  0x05
285 #define GRAPHIC_EQUALIZER_CONTROL       0x06
286 #define AUTOMATIC_GAIN_CONTROL          0x07
287 #define DELAY_CONTROL                   0x08
288 #define BASS_BOOST_CONTROL              0x09
289 #define LOUDNESS_CONTROL                0x0a
290 
291 /*
292  * buffering
293  */
294 
295 struct streambuf {
296     uint8_t *data;
297     uint32_t size;
298     uint32_t prod;
299     uint32_t cons;
300 };
301 
302 static void streambuf_init(struct streambuf *buf, uint32_t size)
303 {
304     g_free(buf->data);
305     buf->size = size - (size % USBAUDIO_PACKET_SIZE);
306     buf->data = g_malloc(buf->size);
307     buf->prod = 0;
308     buf->cons = 0;
309 }
310 
311 static void streambuf_fini(struct streambuf *buf)
312 {
313     g_free(buf->data);
314     buf->data = NULL;
315 }
316 
317 static int streambuf_put(struct streambuf *buf, USBPacket *p)
318 {
319     uint32_t free = buf->size - (buf->prod - buf->cons);
320 
321     if (!free) {
322         return 0;
323     }
324     assert(free >= USBAUDIO_PACKET_SIZE);
325     usb_packet_copy(p, buf->data + (buf->prod % buf->size),
326                     USBAUDIO_PACKET_SIZE);
327     buf->prod += USBAUDIO_PACKET_SIZE;
328     return USBAUDIO_PACKET_SIZE;
329 }
330 
331 static uint8_t *streambuf_get(struct streambuf *buf)
332 {
333     uint32_t used = buf->prod - buf->cons;
334     uint8_t *data;
335 
336     if (!used) {
337         return NULL;
338     }
339     assert(used >= USBAUDIO_PACKET_SIZE);
340     data = buf->data + (buf->cons % buf->size);
341     buf->cons += USBAUDIO_PACKET_SIZE;
342     return data;
343 }
344 
345 typedef struct USBAudioState {
346     /* qemu interfaces */
347     USBDevice dev;
348     QEMUSoundCard card;
349 
350     /* state */
351     struct {
352         enum usb_audio_altset altset;
353         struct audsettings as;
354         SWVoiceOut *voice;
355         bool mute;
356         uint8_t vol[2];
357         struct streambuf buf;
358     } out;
359 
360     /* properties */
361     uint32_t debug;
362     uint32_t buffer;
363 } USBAudioState;
364 
365 #define TYPE_USB_AUDIO "usb-audio"
366 #define USB_AUDIO(obj) OBJECT_CHECK(USBAudioState, (obj), TYPE_USB_AUDIO)
367 
368 static void output_callback(void *opaque, int avail)
369 {
370     USBAudioState *s = opaque;
371     uint8_t *data;
372 
373     for (;;) {
374         if (avail < USBAUDIO_PACKET_SIZE) {
375             return;
376         }
377         data = streambuf_get(&s->out.buf);
378         if (!data) {
379             return;
380         }
381         AUD_write(s->out.voice, data, USBAUDIO_PACKET_SIZE);
382         avail -= USBAUDIO_PACKET_SIZE;
383     }
384 }
385 
386 static int usb_audio_set_output_altset(USBAudioState *s, int altset)
387 {
388     switch (altset) {
389     case ALTSET_OFF:
390         streambuf_init(&s->out.buf, s->buffer);
391         AUD_set_active_out(s->out.voice, false);
392         break;
393     case ALTSET_ON:
394         AUD_set_active_out(s->out.voice, true);
395         break;
396     default:
397         return -1;
398     }
399 
400     if (s->debug) {
401         fprintf(stderr, "usb-audio: set interface %d\n", altset);
402     }
403     s->out.altset = altset;
404     return 0;
405 }
406 
407 /*
408  * Note: we arbitrarily map the volume control range onto -inf..+8 dB
409  */
410 #define ATTRIB_ID(cs, attrib, idif)     \
411     (((cs) << 24) | ((attrib) << 16) | (idif))
412 
413 static int usb_audio_get_control(USBAudioState *s, uint8_t attrib,
414                                  uint16_t cscn, uint16_t idif,
415                                  int length, uint8_t *data)
416 {
417     uint8_t cs = cscn >> 8;
418     uint8_t cn = cscn - 1;      /* -1 for the non-present master control */
419     uint32_t aid = ATTRIB_ID(cs, attrib, idif);
420     int ret = USB_RET_STALL;
421 
422     switch (aid) {
423     case ATTRIB_ID(MUTE_CONTROL, CR_GET_CUR, 0x0200):
424         data[0] = s->out.mute;
425         ret = 1;
426         break;
427     case ATTRIB_ID(VOLUME_CONTROL, CR_GET_CUR, 0x0200):
428         if (cn < 2) {
429             uint16_t vol = (s->out.vol[cn] * 0x8800 + 127) / 255 + 0x8000;
430             data[0] = vol;
431             data[1] = vol >> 8;
432             ret = 2;
433         }
434         break;
435     case ATTRIB_ID(VOLUME_CONTROL, CR_GET_MIN, 0x0200):
436         if (cn < 2) {
437             data[0] = 0x01;
438             data[1] = 0x80;
439             ret = 2;
440         }
441         break;
442     case ATTRIB_ID(VOLUME_CONTROL, CR_GET_MAX, 0x0200):
443         if (cn < 2) {
444             data[0] = 0x00;
445             data[1] = 0x08;
446             ret = 2;
447         }
448         break;
449     case ATTRIB_ID(VOLUME_CONTROL, CR_GET_RES, 0x0200):
450         if (cn < 2) {
451             data[0] = 0x88;
452             data[1] = 0x00;
453             ret = 2;
454         }
455         break;
456     }
457 
458     return ret;
459 }
460 static int usb_audio_set_control(USBAudioState *s, uint8_t attrib,
461                                  uint16_t cscn, uint16_t idif,
462                                  int length, uint8_t *data)
463 {
464     uint8_t cs = cscn >> 8;
465     uint8_t cn = cscn - 1;      /* -1 for the non-present master control */
466     uint32_t aid = ATTRIB_ID(cs, attrib, idif);
467     int ret = USB_RET_STALL;
468     bool set_vol = false;
469 
470     switch (aid) {
471     case ATTRIB_ID(MUTE_CONTROL, CR_SET_CUR, 0x0200):
472         s->out.mute = data[0] & 1;
473         set_vol = true;
474         ret = 0;
475         break;
476     case ATTRIB_ID(VOLUME_CONTROL, CR_SET_CUR, 0x0200):
477         if (cn < 2) {
478             uint16_t vol = data[0] + (data[1] << 8);
479 
480             if (s->debug) {
481                 fprintf(stderr, "usb-audio: vol %04x\n", (uint16_t)vol);
482             }
483 
484             vol -= 0x8000;
485             vol = (vol * 255 + 0x4400) / 0x8800;
486             if (vol > 255) {
487                 vol = 255;
488             }
489 
490             s->out.vol[cn] = vol;
491             set_vol = true;
492             ret = 0;
493         }
494         break;
495     }
496 
497     if (set_vol) {
498         if (s->debug) {
499             fprintf(stderr, "usb-audio: mute %d, lvol %3d, rvol %3d\n",
500                     s->out.mute, s->out.vol[0], s->out.vol[1]);
501         }
502         AUD_set_volume_out(s->out.voice, s->out.mute,
503                            s->out.vol[0], s->out.vol[1]);
504     }
505 
506     return ret;
507 }
508 
509 static void usb_audio_handle_control(USBDevice *dev, USBPacket *p,
510                                     int request, int value, int index,
511                                     int length, uint8_t *data)
512 {
513     USBAudioState *s = USB_AUDIO(dev);
514     int ret = 0;
515 
516     if (s->debug) {
517         fprintf(stderr, "usb-audio: control transaction: "
518                 "request 0x%04x value 0x%04x index 0x%04x length 0x%04x\n",
519                 request, value, index, length);
520     }
521 
522     ret = usb_desc_handle_control(dev, p, request, value, index, length, data);
523     if (ret >= 0) {
524         return;
525     }
526 
527     switch (request) {
528     case ClassInterfaceRequest | CR_GET_CUR:
529     case ClassInterfaceRequest | CR_GET_MIN:
530     case ClassInterfaceRequest | CR_GET_MAX:
531     case ClassInterfaceRequest | CR_GET_RES:
532         ret = usb_audio_get_control(s, request & 0xff, value, index,
533                                     length, data);
534         if (ret < 0) {
535             if (s->debug) {
536                 fprintf(stderr, "usb-audio: fail: get control\n");
537             }
538             goto fail;
539         }
540         p->actual_length = ret;
541         break;
542 
543     case ClassInterfaceOutRequest | CR_SET_CUR:
544     case ClassInterfaceOutRequest | CR_SET_MIN:
545     case ClassInterfaceOutRequest | CR_SET_MAX:
546     case ClassInterfaceOutRequest | CR_SET_RES:
547         ret = usb_audio_set_control(s, request & 0xff, value, index,
548                                     length, data);
549         if (ret < 0) {
550             if (s->debug) {
551                 fprintf(stderr, "usb-audio: fail: set control\n");
552             }
553             goto fail;
554         }
555         break;
556 
557     default:
558 fail:
559         if (s->debug) {
560             fprintf(stderr, "usb-audio: failed control transaction: "
561                     "request 0x%04x value 0x%04x index 0x%04x length 0x%04x\n",
562                     request, value, index, length);
563         }
564         p->status = USB_RET_STALL;
565         break;
566     }
567 }
568 
569 static void usb_audio_set_interface(USBDevice *dev, int iface,
570                                     int old, int value)
571 {
572     USBAudioState *s = USB_AUDIO(dev);
573 
574     if (iface == 1) {
575         usb_audio_set_output_altset(s, value);
576     }
577 }
578 
579 static void usb_audio_handle_reset(USBDevice *dev)
580 {
581     USBAudioState *s = USB_AUDIO(dev);
582 
583     if (s->debug) {
584         fprintf(stderr, "usb-audio: reset\n");
585     }
586     usb_audio_set_output_altset(s, ALTSET_OFF);
587 }
588 
589 static void usb_audio_handle_dataout(USBAudioState *s, USBPacket *p)
590 {
591     if (s->out.altset == ALTSET_OFF) {
592         p->status = USB_RET_STALL;
593         return;
594     }
595 
596     streambuf_put(&s->out.buf, p);
597     if (p->actual_length < p->iov.size && s->debug > 1) {
598         fprintf(stderr, "usb-audio: output overrun (%zd bytes)\n",
599                 p->iov.size - p->actual_length);
600     }
601 }
602 
603 static void usb_audio_handle_data(USBDevice *dev, USBPacket *p)
604 {
605     USBAudioState *s = (USBAudioState *) dev;
606 
607     if (p->pid == USB_TOKEN_OUT && p->ep->nr == 1) {
608         usb_audio_handle_dataout(s, p);
609         return;
610     }
611 
612     p->status = USB_RET_STALL;
613     if (s->debug) {
614         fprintf(stderr, "usb-audio: failed data transaction: "
615                         "pid 0x%x ep 0x%x len 0x%zx\n",
616                         p->pid, p->ep->nr, p->iov.size);
617     }
618 }
619 
620 static void usb_audio_handle_destroy(USBDevice *dev)
621 {
622     USBAudioState *s = USB_AUDIO(dev);
623 
624     if (s->debug) {
625         fprintf(stderr, "usb-audio: destroy\n");
626     }
627 
628     usb_audio_set_output_altset(s, ALTSET_OFF);
629     AUD_close_out(&s->card, s->out.voice);
630     AUD_remove_card(&s->card);
631 
632     streambuf_fini(&s->out.buf);
633 }
634 
635 static void usb_audio_realize(USBDevice *dev, Error **errp)
636 {
637     USBAudioState *s = USB_AUDIO(dev);
638 
639     usb_desc_create_serial(dev);
640     usb_desc_init(dev);
641     s->dev.opaque = s;
642     AUD_register_card(TYPE_USB_AUDIO, &s->card);
643 
644     s->out.altset        = ALTSET_OFF;
645     s->out.mute          = false;
646     s->out.vol[0]        = 240; /* 0 dB */
647     s->out.vol[1]        = 240; /* 0 dB */
648     s->out.as.freq       = USBAUDIO_SAMPLE_RATE;
649     s->out.as.nchannels  = 2;
650     s->out.as.fmt        = AUD_FMT_S16;
651     s->out.as.endianness = 0;
652     streambuf_init(&s->out.buf, s->buffer);
653 
654     s->out.voice = AUD_open_out(&s->card, s->out.voice, TYPE_USB_AUDIO,
655                                 s, output_callback, &s->out.as);
656     AUD_set_volume_out(s->out.voice, s->out.mute, s->out.vol[0], s->out.vol[1]);
657     AUD_set_active_out(s->out.voice, 0);
658 }
659 
660 static const VMStateDescription vmstate_usb_audio = {
661     .name = TYPE_USB_AUDIO,
662     .unmigratable = 1,
663 };
664 
665 static Property usb_audio_properties[] = {
666     DEFINE_PROP_UINT32("debug", USBAudioState, debug, 0),
667     DEFINE_PROP_UINT32("buffer", USBAudioState, buffer,
668                        32 * USBAUDIO_PACKET_SIZE),
669     DEFINE_PROP_END_OF_LIST(),
670 };
671 
672 static void usb_audio_class_init(ObjectClass *klass, void *data)
673 {
674     DeviceClass *dc = DEVICE_CLASS(klass);
675     USBDeviceClass *k = USB_DEVICE_CLASS(klass);
676 
677     dc->vmsd          = &vmstate_usb_audio;
678     dc->props         = usb_audio_properties;
679     set_bit(DEVICE_CATEGORY_SOUND, dc->categories);
680     k->product_desc   = "QEMU USB Audio Interface";
681     k->usb_desc       = &desc_audio;
682     k->realize        = usb_audio_realize;
683     k->handle_reset   = usb_audio_handle_reset;
684     k->handle_control = usb_audio_handle_control;
685     k->handle_data    = usb_audio_handle_data;
686     k->handle_destroy = usb_audio_handle_destroy;
687     k->set_interface  = usb_audio_set_interface;
688 }
689 
690 static const TypeInfo usb_audio_info = {
691     .name          = TYPE_USB_AUDIO,
692     .parent        = TYPE_USB_DEVICE,
693     .instance_size = sizeof(USBAudioState),
694     .class_init    = usb_audio_class_init,
695 };
696 
697 static void usb_audio_register_types(void)
698 {
699     type_register_static(&usb_audio_info);
700     usb_legacy_register(TYPE_USB_AUDIO, "audio", NULL);
701 }
702 
703 type_init(usb_audio_register_types)
704