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1/* SPDX-License-Identifier: MIT */
2/******************************************************************************
3 * sndif.h
4 *
5 * Unified sound-device I/O interface for Xen guest OSes.
6 *
7 * Copyright (C) 2013-2015 GlobalLogic Inc.
8 * Copyright (C) 2016-2017 EPAM Systems Inc.
9 *
10 * Authors: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
11 * Oleksandr Grytsov <oleksandr_grytsov@epam.com>
12 * Oleksandr Dmytryshyn <oleksandr.dmytryshyn@globallogic.com>
13 * Iurii Konovalenko <iurii.konovalenko@globallogic.com>
14 */
15
16#ifndef __XEN_PUBLIC_IO_SNDIF_H__
17#define __XEN_PUBLIC_IO_SNDIF_H__
18
19#include "ring.h"
20#include "../grant_table.h"
21
22/*
23 ******************************************************************************
24 * Protocol version
25 ******************************************************************************
26 */
27#define XENSND_PROTOCOL_VERSION 2
28
29/*
30 ******************************************************************************
31 * Feature and Parameter Negotiation
32 ******************************************************************************
33 *
34 * Front->back notifications: when enqueuing a new request, sending a
35 * notification can be made conditional on xensnd_req (i.e., the generic
36 * hold-off mechanism provided by the ring macros). Backends must set
37 * xensnd_req appropriately (e.g., using RING_FINAL_CHECK_FOR_REQUESTS()).
38 *
39 * Back->front notifications: when enqueuing a new response, sending a
40 * notification can be made conditional on xensnd_resp (i.e., the generic
41 * hold-off mechanism provided by the ring macros). Frontends must set
42 * xensnd_resp appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()).
43 *
44 * The two halves of a para-virtual sound card driver utilize nodes within
45 * XenStore to communicate capabilities and to negotiate operating parameters.
46 * This section enumerates these nodes which reside in the respective front and
47 * backend portions of XenStore, following the XenBus convention.
48 *
49 * All data in XenStore is stored as strings. Nodes specifying numeric
50 * values are encoded in decimal. Integer value ranges listed below are
51 * expressed as fixed sized integer types capable of storing the conversion
52 * of a properly formated node string, without loss of information.
53 *
54 ******************************************************************************
55 * Example configuration
56 ******************************************************************************
57 *
58 * Note: depending on the use-case backend can expose more sound cards and
59 * PCM devices/streams than the underlying HW physically has by employing
60 * SW mixers, configuring virtual sound streams, channels etc.
61 *
62 * This is an example of backend and frontend configuration:
63 *
64 *--------------------------------- Backend -----------------------------------
65 *
66 * /local/domain/0/backend/vsnd/1/0/frontend-id = "1"
67 * /local/domain/0/backend/vsnd/1/0/frontend = "/local/domain/1/device/vsnd/0"
68 * /local/domain/0/backend/vsnd/1/0/state = "4"
69 * /local/domain/0/backend/vsnd/1/0/versions = "1,2"
70 *
71 *--------------------------------- Frontend ----------------------------------
72 *
73 * /local/domain/1/device/vsnd/0/backend-id = "0"
74 * /local/domain/1/device/vsnd/0/backend = "/local/domain/0/backend/vsnd/1/0"
75 * /local/domain/1/device/vsnd/0/state = "4"
76 * /local/domain/1/device/vsnd/0/version = "1"
77 *
78 *----------------------------- Card configuration ----------------------------
79 *
80 * /local/domain/1/device/vsnd/0/short-name = "Card short name"
81 * /local/domain/1/device/vsnd/0/long-name = "Card long name"
82 * /local/domain/1/device/vsnd/0/sample-rates = "8000,32000,44100,48000,96000"
83 * /local/domain/1/device/vsnd/0/sample-formats = "s8,u8,s16_le,s16_be"
84 * /local/domain/1/device/vsnd/0/buffer-size = "262144"
85 *
86 *------------------------------- PCM device 0 --------------------------------
87 *
88 * /local/domain/1/device/vsnd/0/0/name = "General analog"
89 * /local/domain/1/device/vsnd/0/0/channels-max = "5"
90 *
91 *----------------------------- Stream 0, playback ----------------------------
92 *
93 * /local/domain/1/device/vsnd/0/0/0/type = "p"
94 * /local/domain/1/device/vsnd/0/0/0/sample-formats = "s8,u8"
95 * /local/domain/1/device/vsnd/0/0/0/unique-id = "0"
96 *
97 * /local/domain/1/device/vsnd/0/0/0/ring-ref = "386"
98 * /local/domain/1/device/vsnd/0/0/0/event-channel = "15"
99 * /local/domain/1/device/vsnd/0/0/0/evt-ring-ref = "1386"
100 * /local/domain/1/device/vsnd/0/0/0/evt-event-channel = "215"
101 *
102 *------------------------------ Stream 1, capture ----------------------------
103 *
104 * /local/domain/1/device/vsnd/0/0/1/type = "c"
105 * /local/domain/1/device/vsnd/0/0/1/channels-max = "2"
106 * /local/domain/1/device/vsnd/0/0/1/unique-id = "1"
107 *
108 * /local/domain/1/device/vsnd/0/0/1/ring-ref = "384"
109 * /local/domain/1/device/vsnd/0/0/1/event-channel = "13"
110 * /local/domain/1/device/vsnd/0/0/1/evt-ring-ref = "1384"
111 * /local/domain/1/device/vsnd/0/0/1/evt-event-channel = "213"
112 *
113 *------------------------------- PCM device 1 --------------------------------
114 *
115 * /local/domain/1/device/vsnd/0/1/name = "HDMI-0"
116 * /local/domain/1/device/vsnd/0/1/sample-rates = "8000,32000,44100"
117 *
118 *------------------------------ Stream 0, capture ----------------------------
119 *
120 * /local/domain/1/device/vsnd/0/1/0/type = "c"
121 * /local/domain/1/device/vsnd/0/1/0/unique-id = "2"
122 *
123 * /local/domain/1/device/vsnd/0/1/0/ring-ref = "387"
124 * /local/domain/1/device/vsnd/0/1/0/event-channel = "151"
125 * /local/domain/1/device/vsnd/0/1/0/evt-ring-ref = "1387"
126 * /local/domain/1/device/vsnd/0/1/0/evt-event-channel = "351"
127 *
128 *------------------------------- PCM device 2 --------------------------------
129 *
130 * /local/domain/1/device/vsnd/0/2/name = "SPDIF"
131 *
132 *----------------------------- Stream 0, playback ----------------------------
133 *
134 * /local/domain/1/device/vsnd/0/2/0/type = "p"
135 * /local/domain/1/device/vsnd/0/2/0/unique-id = "3"
136 *
137 * /local/domain/1/device/vsnd/0/2/0/ring-ref = "389"
138 * /local/domain/1/device/vsnd/0/2/0/event-channel = "152"
139 * /local/domain/1/device/vsnd/0/2/0/evt-ring-ref = "1389"
140 * /local/domain/1/device/vsnd/0/2/0/evt-event-channel = "452"
141 *
142 ******************************************************************************
143 * Backend XenBus Nodes
144 ******************************************************************************
145 *
146 *----------------------------- Protocol version ------------------------------
147 *
148 * versions
149 * Values: <string>
150 *
151 * List of XENSND_LIST_SEPARATOR separated protocol versions supported
152 * by the backend. For example "1,2,3".
153 *
154 ******************************************************************************
155 * Frontend XenBus Nodes
156 ******************************************************************************
157 *
158 *-------------------------------- Addressing ---------------------------------
159 *
160 * dom-id
161 * Values: <uint16_t>
162 *
163 * Domain identifier.
164 *
165 * dev-id
166 * Values: <uint16_t>
167 *
168 * Device identifier.
169 *
170 * pcm-dev-idx
171 * Values: <uint8_t>
172 *
173 * Zero based contigous index of the PCM device.
174 *
175 * stream-idx
176 * Values: <uint8_t>
177 *
178 * Zero based contigous index of the stream of the PCM device.
179 *
180 * The following pattern is used for addressing:
181 * /local/domain/<dom-id>/device/vsnd/<dev-id>/<pcm-dev-idx>/<stream-idx>/...
182 *
183 *----------------------------- Protocol version ------------------------------
184 *
185 * version
186 * Values: <string>
187 *
188 * Protocol version, chosen among the ones supported by the backend.
189 *
190 *------------------------------- PCM settings --------------------------------
191 *
192 * Every virtualized sound frontend has a set of PCM devices and streams, each
193 * could be individually configured. Part of the PCM configuration can be
194 * defined at higher level of the hierarchy and be fully or partially re-used
195 * by the underlying layers. These configuration values are:
196 * o number of channels (min/max)
197 * o supported sample rates
198 * o supported sample formats.
199 * E.g. one can define these values for the whole card, device or stream.
200 * Every underlying layer in turn can re-define some or all of them to better
201 * fit its needs. For example, card may define number of channels to be
202 * in [1; 8] range, and some particular stream may be limited to [1; 2] only.
203 * The rule is that the underlying layer must be a subset of the upper layer
204 * range.
205 *
206 * channels-min
207 * Values: <uint8_t>
208 *
209 * The minimum amount of channels that is supported, [1; channels-max].
210 * Optional, if not set or omitted a value of 1 is used.
211 *
212 * channels-max
213 * Values: <uint8_t>
214 *
215 * The maximum amount of channels that is supported.
216 * Must be at least <channels-min>.
217 *
218 * sample-rates
219 * Values: <list of uint32_t>
220 *
221 * List of supported sample rates separated by XENSND_LIST_SEPARATOR.
222 * Sample rates are expressed as a list of decimal values w/o any
223 * ordering requirement.
224 *
225 * sample-formats
226 * Values: <list of XENSND_PCM_FORMAT_XXX_STR>
227 *
228 * List of supported sample formats separated by XENSND_LIST_SEPARATOR.
229 * Items must not exceed XENSND_SAMPLE_FORMAT_MAX_LEN length.
230 *
231 * buffer-size
232 * Values: <uint32_t>
233 *
234 * The maximum size in octets of the buffer to allocate per stream.
235 *
236 *----------------------- Virtual sound card settings -------------------------
237 * short-name
238 * Values: <char[32]>
239 *
240 * Short name of the virtual sound card. Optional.
241 *
242 * long-name
243 * Values: <char[80]>
244 *
245 * Long name of the virtual sound card. Optional.
246 *
247 *----------------------------- Device settings -------------------------------
248 * name
249 * Values: <char[80]>
250 *
251 * Name of the sound device within the virtual sound card. Optional.
252 *
253 *----------------------------- Stream settings -------------------------------
254 *
255 * type
256 * Values: "p", "c"
257 *
258 * Stream type: "p" - playback stream, "c" - capture stream
259 *
260 * If both capture and playback are needed then two streams need to be
261 * defined under the same device.
262 *
263 * unique-id
264 * Values: <string>
265 *
266 * After stream initialization it is assigned a unique ID, so every
267 * stream of the frontend can be identified by the backend by this ID.
268 * This can be UUID or such.
269 *
270 *-------------------- Stream Request Transport Parameters --------------------
271 *
272 * event-channel
273 * Values: <uint32_t>
274 *
275 * The identifier of the Xen event channel used to signal activity
276 * in the ring buffer.
277 *
278 * ring-ref
279 * Values: <uint32_t>
280 *
281 * The Xen grant reference granting permission for the backend to map
282 * a sole page in a single page sized ring buffer.
283 *
284 *--------------------- Stream Event Transport Parameters ---------------------
285 *
286 * This communication path is used to deliver asynchronous events from backend
287 * to frontend, set up per stream.
288 *
289 * evt-event-channel
290 * Values: <uint32_t>
291 *
292 * The identifier of the Xen event channel used to signal activity
293 * in the ring buffer.
294 *
295 * evt-ring-ref
296 * Values: <uint32_t>
297 *
298 * The Xen grant reference granting permission for the backend to map
299 * a sole page in a single page sized ring buffer.
300 *
301 ******************************************************************************
302 * STATE DIAGRAMS
303 ******************************************************************************
304 *
305 * Tool stack creates front and back state nodes with initial state
306 * XenbusStateInitialising.
307 * Tool stack creates and sets up frontend sound configuration nodes per domain.
308 *
309 * Front Back
310 * ================================= =====================================
311 * XenbusStateInitialising XenbusStateInitialising
312 * o Query backend device identification
313 * data.
314 * o Open and validate backend device.
315 * |
316 * |
317 * V
318 * XenbusStateInitWait
319 *
320 * o Query frontend configuration
321 * o Allocate and initialize
322 * event channels per configured
323 * playback/capture stream.
324 * o Publish transport parameters
325 * that will be in effect during
326 * this connection.
327 * |
328 * |
329 * V
330 * XenbusStateInitialised
331 *
332 * o Query frontend transport parameters.
333 * o Connect to the event channels.
334 * |
335 * |
336 * V
337 * XenbusStateConnected
338 *
339 * o Create and initialize OS
340 * virtual sound device instances
341 * as per configuration.
342 * |
343 * |
344 * V
345 * XenbusStateConnected
346 *
347 * XenbusStateUnknown
348 * XenbusStateClosed
349 * XenbusStateClosing
350 * o Remove virtual sound device
351 * o Remove event channels
352 * |
353 * |
354 * V
355 * XenbusStateClosed
356 *
357 *------------------------------- Recovery flow -------------------------------
358 *
359 * In case of frontend unrecoverable errors backend handles that as
360 * if frontend goes into the XenbusStateClosed state.
361 *
362 * In case of backend unrecoverable errors frontend tries removing
363 * the virtualized device. If this is possible at the moment of error,
364 * then frontend goes into the XenbusStateInitialising state and is ready for
365 * new connection with backend. If the virtualized device is still in use and
366 * cannot be removed, then frontend goes into the XenbusStateReconfiguring state
367 * until either the virtualized device removed or backend initiates a new
368 * connection. On the virtualized device removal frontend goes into the
369 * XenbusStateInitialising state.
370 *
371 * Note on XenbusStateReconfiguring state of the frontend: if backend has
372 * unrecoverable errors then frontend cannot send requests to the backend
373 * and thus cannot provide functionality of the virtualized device anymore.
374 * After backend is back to normal the virtualized device may still hold some
375 * state: configuration in use, allocated buffers, client application state etc.
376 * So, in most cases, this will require frontend to implement complex recovery
377 * reconnect logic. Instead, by going into XenbusStateReconfiguring state,
378 * frontend will make sure no new clients of the virtualized device are
379 * accepted, allow existing client(s) to exit gracefully by signaling error
380 * state etc.
381 * Once all the clients are gone frontend can reinitialize the virtualized
382 * device and get into XenbusStateInitialising state again signaling the
383 * backend that a new connection can be made.
384 *
385 * There are multiple conditions possible under which frontend will go from
386 * XenbusStateReconfiguring into XenbusStateInitialising, some of them are OS
387 * specific. For example:
388 * 1. The underlying OS framework may provide callbacks to signal that the last
389 * client of the virtualized device has gone and the device can be removed
390 * 2. Frontend can schedule a deferred work (timer/tasklet/workqueue)
391 * to periodically check if this is the right time to re-try removal of
392 * the virtualized device.
393 * 3. By any other means.
394 *
395 ******************************************************************************
396 * PCM FORMATS
397 ******************************************************************************
398 *
399 * XENSND_PCM_FORMAT_<format>[_<endian>]
400 *
401 * format: <S/U/F><bits> or <name>
402 * S - signed, U - unsigned, F - float
403 * bits - 8, 16, 24, 32
404 * name - MU_LAW, GSM, etc.
405 *
406 * endian: <LE/BE>, may be absent
407 * LE - Little endian, BE - Big endian
408 */
409#define XENSND_PCM_FORMAT_S8 0
410#define XENSND_PCM_FORMAT_U8 1
411#define XENSND_PCM_FORMAT_S16_LE 2
412#define XENSND_PCM_FORMAT_S16_BE 3
413#define XENSND_PCM_FORMAT_U16_LE 4
414#define XENSND_PCM_FORMAT_U16_BE 5
415#define XENSND_PCM_FORMAT_S24_LE 6
416#define XENSND_PCM_FORMAT_S24_BE 7
417#define XENSND_PCM_FORMAT_U24_LE 8
418#define XENSND_PCM_FORMAT_U24_BE 9
419#define XENSND_PCM_FORMAT_S32_LE 10
420#define XENSND_PCM_FORMAT_S32_BE 11
421#define XENSND_PCM_FORMAT_U32_LE 12
422#define XENSND_PCM_FORMAT_U32_BE 13
423#define XENSND_PCM_FORMAT_F32_LE 14 /* 4-byte float, IEEE-754 32-bit, */
424#define XENSND_PCM_FORMAT_F32_BE 15 /* range -1.0 to 1.0 */
425#define XENSND_PCM_FORMAT_F64_LE 16 /* 8-byte float, IEEE-754 64-bit, */
426#define XENSND_PCM_FORMAT_F64_BE 17 /* range -1.0 to 1.0 */
427#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE 18
428#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE 19
429#define XENSND_PCM_FORMAT_MU_LAW 20
430#define XENSND_PCM_FORMAT_A_LAW 21
431#define XENSND_PCM_FORMAT_IMA_ADPCM 22
432#define XENSND_PCM_FORMAT_MPEG 23
433#define XENSND_PCM_FORMAT_GSM 24
434
435/*
436 ******************************************************************************
437 * REQUEST CODES
438 ******************************************************************************
439 */
440#define XENSND_OP_OPEN 0
441#define XENSND_OP_CLOSE 1
442#define XENSND_OP_READ 2
443#define XENSND_OP_WRITE 3
444#define XENSND_OP_SET_VOLUME 4
445#define XENSND_OP_GET_VOLUME 5
446#define XENSND_OP_MUTE 6
447#define XENSND_OP_UNMUTE 7
448#define XENSND_OP_TRIGGER 8
449#define XENSND_OP_HW_PARAM_QUERY 9
450
451#define XENSND_OP_TRIGGER_START 0
452#define XENSND_OP_TRIGGER_PAUSE 1
453#define XENSND_OP_TRIGGER_STOP 2
454#define XENSND_OP_TRIGGER_RESUME 3
455
456/*
457 ******************************************************************************
458 * EVENT CODES
459 ******************************************************************************
460 */
461#define XENSND_EVT_CUR_POS 0
462
463/*
464 ******************************************************************************
465 * XENSTORE FIELD AND PATH NAME STRINGS, HELPERS
466 ******************************************************************************
467 */
468#define XENSND_DRIVER_NAME "vsnd"
469
470#define XENSND_LIST_SEPARATOR ","
471/* Field names */
472#define XENSND_FIELD_BE_VERSIONS "versions"
473#define XENSND_FIELD_FE_VERSION "version"
474#define XENSND_FIELD_VCARD_SHORT_NAME "short-name"
475#define XENSND_FIELD_VCARD_LONG_NAME "long-name"
476#define XENSND_FIELD_RING_REF "ring-ref"
477#define XENSND_FIELD_EVT_CHNL "event-channel"
478#define XENSND_FIELD_EVT_RING_REF "evt-ring-ref"
479#define XENSND_FIELD_EVT_EVT_CHNL "evt-event-channel"
480#define XENSND_FIELD_DEVICE_NAME "name"
481#define XENSND_FIELD_TYPE "type"
482#define XENSND_FIELD_STREAM_UNIQUE_ID "unique-id"
483#define XENSND_FIELD_CHANNELS_MIN "channels-min"
484#define XENSND_FIELD_CHANNELS_MAX "channels-max"
485#define XENSND_FIELD_SAMPLE_RATES "sample-rates"
486#define XENSND_FIELD_SAMPLE_FORMATS "sample-formats"
487#define XENSND_FIELD_BUFFER_SIZE "buffer-size"
488
489/* Stream type field values. */
490#define XENSND_STREAM_TYPE_PLAYBACK "p"
491#define XENSND_STREAM_TYPE_CAPTURE "c"
492/* Sample rate max string length */
493#define XENSND_SAMPLE_RATE_MAX_LEN 11
494/* Sample format field values */
495#define XENSND_SAMPLE_FORMAT_MAX_LEN 24
496
497#define XENSND_PCM_FORMAT_S8_STR "s8"
498#define XENSND_PCM_FORMAT_U8_STR "u8"
499#define XENSND_PCM_FORMAT_S16_LE_STR "s16_le"
500#define XENSND_PCM_FORMAT_S16_BE_STR "s16_be"
501#define XENSND_PCM_FORMAT_U16_LE_STR "u16_le"
502#define XENSND_PCM_FORMAT_U16_BE_STR "u16_be"
503#define XENSND_PCM_FORMAT_S24_LE_STR "s24_le"
504#define XENSND_PCM_FORMAT_S24_BE_STR "s24_be"
505#define XENSND_PCM_FORMAT_U24_LE_STR "u24_le"
506#define XENSND_PCM_FORMAT_U24_BE_STR "u24_be"
507#define XENSND_PCM_FORMAT_S32_LE_STR "s32_le"
508#define XENSND_PCM_FORMAT_S32_BE_STR "s32_be"
509#define XENSND_PCM_FORMAT_U32_LE_STR "u32_le"
510#define XENSND_PCM_FORMAT_U32_BE_STR "u32_be"
511#define XENSND_PCM_FORMAT_F32_LE_STR "float_le"
512#define XENSND_PCM_FORMAT_F32_BE_STR "float_be"
513#define XENSND_PCM_FORMAT_F64_LE_STR "float64_le"
514#define XENSND_PCM_FORMAT_F64_BE_STR "float64_be"
515#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE_STR "iec958_subframe_le"
516#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE_STR "iec958_subframe_be"
517#define XENSND_PCM_FORMAT_MU_LAW_STR "mu_law"
518#define XENSND_PCM_FORMAT_A_LAW_STR "a_law"
519#define XENSND_PCM_FORMAT_IMA_ADPCM_STR "ima_adpcm"
520#define XENSND_PCM_FORMAT_MPEG_STR "mpeg"
521#define XENSND_PCM_FORMAT_GSM_STR "gsm"
522
523
524/*
525 ******************************************************************************
526 * STATUS RETURN CODES
527 ******************************************************************************
528 *
529 * Status return code is zero on success and -XEN_EXX on failure.
530 *
531 ******************************************************************************
532 * Assumptions
533 ******************************************************************************
534 * o usage of grant reference 0 as invalid grant reference:
535 * grant reference 0 is valid, but never exposed to a PV driver,
536 * because of the fact it is already in use/reserved by the PV console.
537 * o all references in this document to page sizes must be treated
538 * as pages of size XEN_PAGE_SIZE unless otherwise noted.
539 *
540 ******************************************************************************
541 * Description of the protocol between frontend and backend driver
542 ******************************************************************************
543 *
544 * The two halves of a Para-virtual sound driver communicate with
545 * each other using shared pages and event channels.
546 * Shared page contains a ring with request/response packets.
547 *
548 * Packets, used for input/output operations, e.g. read/write, set/get volume,
549 * etc., provide offset/length fields in order to allow asynchronous protocol
550 * operation with buffer space sharing: part of the buffer allocated at
551 * XENSND_OP_OPEN can be used for audio samples and part, for example,
552 * for volume control.
553 *
554 * All reserved fields in the structures below must be 0.
555 *
556 *---------------------------------- Requests ---------------------------------
557 *
558 * All request packets have the same length (64 octets)
559 * All request packets have common header:
560 * 0 1 2 3 octet
561 * +----------------+----------------+----------------+----------------+
562 * | id | operation | reserved | 4
563 * +----------------+----------------+----------------+----------------+
564 * | reserved | 8
565 * +----------------+----------------+----------------+----------------+
566 * id - uint16_t, private guest value, echoed in response
567 * operation - uint8_t, operation code, XENSND_OP_???
568 *
569 * For all packets which use offset and length:
570 * offset - uint32_t, read or write data offset within the shared buffer,
571 * passed with XENSND_OP_OPEN request, octets,
572 * [0; XENSND_OP_OPEN.buffer_sz - 1].
573 * length - uint32_t, read or write data length, octets
574 *
575 * Request open - open a PCM stream for playback or capture:
576 *
577 * 0 1 2 3 octet
578 * +----------------+----------------+----------------+----------------+
579 * | id | XENSND_OP_OPEN | reserved | 4
580 * +----------------+----------------+----------------+----------------+
581 * | reserved | 8
582 * +----------------+----------------+----------------+----------------+
583 * | pcm_rate | 12
584 * +----------------+----------------+----------------+----------------+
585 * | pcm_format | pcm_channels | reserved | 16
586 * +----------------+----------------+----------------+----------------+
587 * | buffer_sz | 20
588 * +----------------+----------------+----------------+----------------+
589 * | gref_directory | 24
590 * +----------------+----------------+----------------+----------------+
591 * | period_sz | 28
592 * +----------------+----------------+----------------+----------------+
593 * | reserved | 32
594 * +----------------+----------------+----------------+----------------+
595 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
596 * +----------------+----------------+----------------+----------------+
597 * | reserved | 64
598 * +----------------+----------------+----------------+----------------+
599 *
600 * pcm_rate - uint32_t, stream data rate, Hz
601 * pcm_format - uint8_t, XENSND_PCM_FORMAT_XXX value
602 * pcm_channels - uint8_t, number of channels of this stream,
603 * [channels-min; channels-max]
604 * buffer_sz - uint32_t, buffer size to be allocated, octets
605 * period_sz - uint32_t, event period size, octets
606 * This is the requested value of the period at which frontend would
607 * like to receive XENSND_EVT_CUR_POS notifications from the backend when
608 * stream position advances during playback/capture.
609 * It shows how many octets are expected to be played/captured before
610 * sending such an event.
611 * If set to 0 no XENSND_EVT_CUR_POS events are sent by the backend.
612 *
613 * gref_directory - grant_ref_t, a reference to the first shared page
614 * describing shared buffer references. At least one page exists. If shared
615 * buffer size (buffer_sz) exceeds what can be addressed by this single page,
616 * then reference to the next page must be supplied (see gref_dir_next_page
617 * below)
618 */
619
620struct xensnd_open_req {
621 uint32_t pcm_rate;
622 uint8_t pcm_format;
623 uint8_t pcm_channels;
624 uint16_t reserved;
625 uint32_t buffer_sz;
626 grant_ref_t gref_directory;
627 uint32_t period_sz;
628};
629
630/*
631 * Shared page for XENSND_OP_OPEN buffer descriptor (gref_directory in the
632 * request) employs a list of pages, describing all pages of the shared data
633 * buffer:
634 * 0 1 2 3 octet
635 * +----------------+----------------+----------------+----------------+
636 * | gref_dir_next_page | 4
637 * +----------------+----------------+----------------+----------------+
638 * | gref[0] | 8
639 * +----------------+----------------+----------------+----------------+
640 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
641 * +----------------+----------------+----------------+----------------+
642 * | gref[i] | i*4+8
643 * +----------------+----------------+----------------+----------------+
644 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
645 * +----------------+----------------+----------------+----------------+
646 * | gref[N - 1] | N*4+8
647 * +----------------+----------------+----------------+----------------+
648 *
649 * gref_dir_next_page - grant_ref_t, reference to the next page describing
650 * page directory. Must be 0 if there are no more pages in the list.
651 * gref[i] - grant_ref_t, reference to a shared page of the buffer
652 * allocated at XENSND_OP_OPEN
653 *
654 * Number of grant_ref_t entries in the whole page directory is not
655 * passed, but instead can be calculated as:
656 * num_grefs_total = (XENSND_OP_OPEN.buffer_sz + XEN_PAGE_SIZE - 1) /
657 * XEN_PAGE_SIZE
658 */
659
660struct xensnd_page_directory {
661 grant_ref_t gref_dir_next_page;
662 grant_ref_t gref[1]; /* Variable length */
663};
664
665/*
666 * Request close - close an opened pcm stream:
667 * 0 1 2 3 octet
668 * +----------------+----------------+----------------+----------------+
669 * | id | XENSND_OP_CLOSE| reserved | 4
670 * +----------------+----------------+----------------+----------------+
671 * | reserved | 8
672 * +----------------+----------------+----------------+----------------+
673 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
674 * +----------------+----------------+----------------+----------------+
675 * | reserved | 64
676 * +----------------+----------------+----------------+----------------+
677 *
678 * Request read/write - used for read (for capture) or write (for playback):
679 * 0 1 2 3 octet
680 * +----------------+----------------+----------------+----------------+
681 * | id | operation | reserved | 4
682 * +----------------+----------------+----------------+----------------+
683 * | reserved | 8
684 * +----------------+----------------+----------------+----------------+
685 * | offset | 12
686 * +----------------+----------------+----------------+----------------+
687 * | length | 16
688 * +----------------+----------------+----------------+----------------+
689 * | reserved | 20
690 * +----------------+----------------+----------------+----------------+
691 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
692 * +----------------+----------------+----------------+----------------+
693 * | reserved | 64
694 * +----------------+----------------+----------------+----------------+
695 *
696 * operation - XENSND_OP_READ for read or XENSND_OP_WRITE for write
697 */
698
699struct xensnd_rw_req {
700 uint32_t offset;
701 uint32_t length;
702};
703
704/*
705 * Request set/get volume - set/get channels' volume of the stream given:
706 * 0 1 2 3 octet
707 * +----------------+----------------+----------------+----------------+
708 * | id | operation | reserved | 4
709 * +----------------+----------------+----------------+----------------+
710 * | reserved | 8
711 * +----------------+----------------+----------------+----------------+
712 * | offset | 12
713 * +----------------+----------------+----------------+----------------+
714 * | length | 16
715 * +----------------+----------------+----------------+----------------+
716 * | reserved | 20
717 * +----------------+----------------+----------------+----------------+
718 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
719 * +----------------+----------------+----------------+----------------+
720 * | reserved | 64
721 * +----------------+----------------+----------------+----------------+
722 *
723 * operation - XENSND_OP_SET_VOLUME for volume set
724 * or XENSND_OP_GET_VOLUME for volume get
725 * Buffer passed with XENSND_OP_OPEN is used to exchange volume
726 * values:
727 *
728 * 0 1 2 3 octet
729 * +----------------+----------------+----------------+----------------+
730 * | channel[0] | 4
731 * +----------------+----------------+----------------+----------------+
732 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
733 * +----------------+----------------+----------------+----------------+
734 * | channel[i] | i*4
735 * +----------------+----------------+----------------+----------------+
736 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
737 * +----------------+----------------+----------------+----------------+
738 * | channel[N - 1] | (N-1)*4
739 * +----------------+----------------+----------------+----------------+
740 *
741 * N = XENSND_OP_OPEN.pcm_channels
742 * i - uint8_t, index of a channel
743 * channel[i] - sint32_t, volume of i-th channel
744 * Volume is expressed as a signed value in steps of 0.001 dB,
745 * while 0 being 0 dB.
746 *
747 * Request mute/unmute - mute/unmute stream:
748 * 0 1 2 3 octet
749 * +----------------+----------------+----------------+----------------+
750 * | id | operation | reserved | 4
751 * +----------------+----------------+----------------+----------------+
752 * | reserved | 8
753 * +----------------+----------------+----------------+----------------+
754 * | offset | 12
755 * +----------------+----------------+----------------+----------------+
756 * | length | 16
757 * +----------------+----------------+----------------+----------------+
758 * | reserved | 20
759 * +----------------+----------------+----------------+----------------+
760 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
761 * +----------------+----------------+----------------+----------------+
762 * | reserved | 64
763 * +----------------+----------------+----------------+----------------+
764 *
765 * operation - XENSND_OP_MUTE for mute or XENSND_OP_UNMUTE for unmute
766 * Buffer passed with XENSND_OP_OPEN is used to exchange mute/unmute
767 * values:
768 *
769 * 0 octet
770 * +----------------+----------------+----------------+----------------+
771 * | channel[0] | 4
772 * +----------------+----------------+----------------+----------------+
773 * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
774 * +----------------+----------------+----------------+----------------+
775 * | channel[i] | i*4
776 * +----------------+----------------+----------------+----------------+
777 * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
778 * +----------------+----------------+----------------+----------------+
779 * | channel[N - 1] | (N-1)*4
780 * +----------------+----------------+----------------+----------------+
781 *
782 * N = XENSND_OP_OPEN.pcm_channels
783 * i - uint8_t, index of a channel
784 * channel[i] - uint8_t, non-zero if i-th channel needs to be muted/unmuted
785 *
786 *------------------------------------ N.B. -----------------------------------
787 *
788 * The 'struct xensnd_rw_req' is also used for XENSND_OP_SET_VOLUME,
789 * XENSND_OP_GET_VOLUME, XENSND_OP_MUTE, XENSND_OP_UNMUTE.
790 *
791 * Request stream running state change - trigger PCM stream running state
792 * to start, stop, pause or resume:
793 *
794 * 0 1 2 3 octet
795 * +----------------+----------------+----------------+----------------+
796 * | id | _OP_TRIGGER | reserved | 4
797 * +----------------+----------------+----------------+----------------+
798 * | reserved | 8
799 * +----------------+----------------+----------------+----------------+
800 * | type | reserved | 12
801 * +----------------+----------------+----------------+----------------+
802 * | reserved | 16
803 * +----------------+----------------+----------------+----------------+
804 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
805 * +----------------+----------------+----------------+----------------+
806 * | reserved | 64
807 * +----------------+----------------+----------------+----------------+
808 *
809 * type - uint8_t, XENSND_OP_TRIGGER_XXX value
810 */
811
812struct xensnd_trigger_req {
813 uint8_t type;
814};
815
816/*
817 * Request stream parameter ranges: request intervals and
818 * masks of supported ranges for stream configuration values.
819 *
820 * Sound device configuration for a particular stream is a limited subset
821 * of the multidimensional configuration available on XenStore, e.g.
822 * once the frame rate has been selected there is a limited supported range
823 * for sample rates becomes available (which might be the same set configured
824 * on XenStore or less). For example, selecting 96kHz sample rate may limit
825 * number of channels available for such configuration from 4 to 2, etc.
826 * Thus, each call to XENSND_OP_HW_PARAM_QUERY may reduce configuration
827 * space making it possible to iteratively get the final stream configuration,
828 * used in XENSND_OP_OPEN request.
829 *
830 * See response format for this request.
831 *
832 * 0 1 2 3 octet
833 * +----------------+----------------+----------------+----------------+
834 * | id | _HW_PARAM_QUERY| reserved | 4
835 * +----------------+----------------+----------------+----------------+
836 * | reserved | 8
837 * +----------------+----------------+----------------+----------------+
838 * | formats mask low 32-bit | 12
839 * +----------------+----------------+----------------+----------------+
840 * | formats mask high 32-bit | 16
841 * +----------------+----------------+----------------+----------------+
842 * | min rate | 20
843 * +----------------+----------------+----------------+----------------+
844 * | max rate | 24
845 * +----------------+----------------+----------------+----------------+
846 * | min channels | 28
847 * +----------------+----------------+----------------+----------------+
848 * | max channels | 32
849 * +----------------+----------------+----------------+----------------+
850 * | min buffer frames | 36
851 * +----------------+----------------+----------------+----------------+
852 * | max buffer frames | 40
853 * +----------------+----------------+----------------+----------------+
854 * | min period frames | 44
855 * +----------------+----------------+----------------+----------------+
856 * | max period frames | 48
857 * +----------------+----------------+----------------+----------------+
858 * | reserved | 52
859 * +----------------+----------------+----------------+----------------+
860 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
861 * +----------------+----------------+----------------+----------------+
862 * | reserved | 64
863 * +----------------+----------------+----------------+----------------+
864 *
865 * formats - uint64_t, bit mask representing values of the parameter
866 * made as bitwise OR of (1 << XENSND_PCM_FORMAT_XXX) values
867 *
868 * For interval parameters:
869 * min - uint32_t, minimum value of the parameter
870 * max - uint32_t, maximum value of the parameter
871 *
872 * Frame is defined as a product of the number of channels by the
873 * number of octets per one sample.
874 */
875
876struct xensnd_query_hw_param {
877 uint64_t formats;
878 struct {
879 uint32_t min;
880 uint32_t max;
881 } rates;
882 struct {
883 uint32_t min;
884 uint32_t max;
885 } channels;
886 struct {
887 uint32_t min;
888 uint32_t max;
889 } buffer;
890 struct {
891 uint32_t min;
892 uint32_t max;
893 } period;
894};
895
896/*
897 *---------------------------------- Responses --------------------------------
898 *
899 * All response packets have the same length (64 octets)
900 *
901 * All response packets have common header:
902 * 0 1 2 3 octet
903 * +----------------+----------------+----------------+----------------+
904 * | id | operation | reserved | 4
905 * +----------------+----------------+----------------+----------------+
906 * | status | 8
907 * +----------------+----------------+----------------+----------------+
908 *
909 * id - uint16_t, copied from the request
910 * operation - uint8_t, XENSND_OP_* - copied from request
911 * status - int32_t, response status, zero on success and -XEN_EXX on failure
912 *
913 *
914 * HW parameter query response - response for XENSND_OP_HW_PARAM_QUERY:
915 * 0 1 2 3 octet
916 * +----------------+----------------+----------------+----------------+
917 * | id | operation | reserved | 4
918 * +----------------+----------------+----------------+----------------+
919 * | status | 8
920 * +----------------+----------------+----------------+----------------+
921 * | formats mask low 32-bit | 12
922 * +----------------+----------------+----------------+----------------+
923 * | formats mask high 32-bit | 16
924 * +----------------+----------------+----------------+----------------+
925 * | min rate | 20
926 * +----------------+----------------+----------------+----------------+
927 * | max rate | 24
928 * +----------------+----------------+----------------+----------------+
929 * | min channels | 28
930 * +----------------+----------------+----------------+----------------+
931 * | max channels | 32
932 * +----------------+----------------+----------------+----------------+
933 * | min buffer frames | 36
934 * +----------------+----------------+----------------+----------------+
935 * | max buffer frames | 40
936 * +----------------+----------------+----------------+----------------+
937 * | min period frames | 44
938 * +----------------+----------------+----------------+----------------+
939 * | max period frames | 48
940 * +----------------+----------------+----------------+----------------+
941 * | reserved | 52
942 * +----------------+----------------+----------------+----------------+
943 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
944 * +----------------+----------------+----------------+----------------+
945 * | reserved | 64
946 * +----------------+----------------+----------------+----------------+
947 *
948 * Meaning of the values in this response is the same as for
949 * XENSND_OP_HW_PARAM_QUERY request.
950 */
951
952/*
953 *----------------------------------- Events ----------------------------------
954 *
955 * Events are sent via shared page allocated by the front and propagated by
956 * evt-event-channel/evt-ring-ref XenStore entries
957 * All event packets have the same length (64 octets)
958 * All event packets have common header:
959 * 0 1 2 3 octet
960 * +----------------+----------------+----------------+----------------+
961 * | id | type | reserved | 4
962 * +----------------+----------------+----------------+----------------+
963 * | reserved | 8
964 * +----------------+----------------+----------------+----------------+
965 *
966 * id - uint16_t, event id, may be used by front
967 * type - uint8_t, type of the event
968 *
969 *
970 * Current stream position - event from back to front when stream's
971 * playback/capture position has advanced:
972 * 0 1 2 3 octet
973 * +----------------+----------------+----------------+----------------+
974 * | id | _EVT_CUR_POS | reserved | 4
975 * +----------------+----------------+----------------+----------------+
976 * | reserved | 8
977 * +----------------+----------------+----------------+----------------+
978 * | position low 32-bit | 12
979 * +----------------+----------------+----------------+----------------+
980 * | position high 32-bit | 16
981 * +----------------+----------------+----------------+----------------+
982 * | reserved | 20
983 * +----------------+----------------+----------------+----------------+
984 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
985 * +----------------+----------------+----------------+----------------+
986 * | reserved | 64
987 * +----------------+----------------+----------------+----------------+
988 *
989 * position - current value of stream's playback/capture position, octets
990 *
991 */
992
993struct xensnd_cur_pos_evt {
994 uint64_t position;
995};
996
997struct xensnd_req {
998 uint16_t id;
999 uint8_t operation;
1000 uint8_t reserved[5];
1001 union {
1002 struct xensnd_open_req open;
1003 struct xensnd_rw_req rw;
1004 struct xensnd_trigger_req trigger;
1005 struct xensnd_query_hw_param hw_param;
1006 uint8_t reserved[56];
1007 } op;
1008};
1009
1010struct xensnd_resp {
1011 uint16_t id;
1012 uint8_t operation;
1013 uint8_t reserved;
1014 int32_t status;
1015 union {
1016 struct xensnd_query_hw_param hw_param;
1017 uint8_t reserved1[56];
1018 } resp;
1019};
1020
1021struct xensnd_evt {
1022 uint16_t id;
1023 uint8_t type;
1024 uint8_t reserved[5];
1025 union {
1026 struct xensnd_cur_pos_evt cur_pos;
1027 uint8_t reserved[56];
1028 } op;
1029};
1030
1031DEFINE_RING_TYPES(xen_sndif, struct xensnd_req, struct xensnd_resp);
1032
1033/*
1034 ******************************************************************************
1035 * Back to front events delivery
1036 ******************************************************************************
1037 * In order to deliver asynchronous events from back to front a shared page is
1038 * allocated by front and its granted reference propagated to back via
1039 * XenStore entries (evt-ring-ref/evt-event-channel).
1040 * This page has a common header used by both front and back to synchronize
1041 * access and control event's ring buffer, while back being a producer of the
1042 * events and front being a consumer. The rest of the page after the header
1043 * is used for event packets.
1044 *
1045 * Upon reception of an event(s) front may confirm its reception
1046 * for either each event, group of events or none.
1047 */
1048
1049struct xensnd_event_page {
1050 uint32_t in_cons;
1051 uint32_t in_prod;
1052 uint8_t reserved[56];
1053};
1054
1055#define XENSND_EVENT_PAGE_SIZE XEN_PAGE_SIZE
1056#define XENSND_IN_RING_OFFS (sizeof(struct xensnd_event_page))
1057#define XENSND_IN_RING_SIZE (XENSND_EVENT_PAGE_SIZE - XENSND_IN_RING_OFFS)
1058#define XENSND_IN_RING_LEN (XENSND_IN_RING_SIZE / sizeof(struct xensnd_evt))
1059#define XENSND_IN_RING(page) \
1060 ((struct xensnd_evt *)((char *)(page) + XENSND_IN_RING_OFFS))
1061#define XENSND_IN_RING_REF(page, idx) \
1062 (XENSND_IN_RING((page))[(idx) % XENSND_IN_RING_LEN])
1063
1064#endif /* __XEN_PUBLIC_IO_SNDIF_H__ */
1/* SPDX-License-Identifier: MIT */
2/******************************************************************************
3 * sndif.h
4 *
5 * Unified sound-device I/O interface for Xen guest OSes.
6 *
7 * Copyright (C) 2013-2015 GlobalLogic Inc.
8 * Copyright (C) 2016-2017 EPAM Systems Inc.
9 *
10 * Authors: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
11 * Oleksandr Grytsov <oleksandr_grytsov@epam.com>
12 * Oleksandr Dmytryshyn <oleksandr.dmytryshyn@globallogic.com>
13 * Iurii Konovalenko <iurii.konovalenko@globallogic.com>
14 */
15
16#ifndef __XEN_PUBLIC_IO_SNDIF_H__
17#define __XEN_PUBLIC_IO_SNDIF_H__
18
19#include "ring.h"
20#include "../grant_table.h"
21
22/*
23 ******************************************************************************
24 * Protocol version
25 ******************************************************************************
26 */
27#define XENSND_PROTOCOL_VERSION 2
28
29/*
30 ******************************************************************************
31 * Feature and Parameter Negotiation
32 ******************************************************************************
33 *
34 * Front->back notifications: when enqueuing a new request, sending a
35 * notification can be made conditional on xensnd_req (i.e., the generic
36 * hold-off mechanism provided by the ring macros). Backends must set
37 * xensnd_req appropriately (e.g., using RING_FINAL_CHECK_FOR_REQUESTS()).
38 *
39 * Back->front notifications: when enqueuing a new response, sending a
40 * notification can be made conditional on xensnd_resp (i.e., the generic
41 * hold-off mechanism provided by the ring macros). Frontends must set
42 * xensnd_resp appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()).
43 *
44 * The two halves of a para-virtual sound card driver utilize nodes within
45 * XenStore to communicate capabilities and to negotiate operating parameters.
46 * This section enumerates these nodes which reside in the respective front and
47 * backend portions of XenStore, following the XenBus convention.
48 *
49 * All data in XenStore is stored as strings. Nodes specifying numeric
50 * values are encoded in decimal. Integer value ranges listed below are
51 * expressed as fixed sized integer types capable of storing the conversion
52 * of a properly formated node string, without loss of information.
53 *
54 ******************************************************************************
55 * Example configuration
56 ******************************************************************************
57 *
58 * Note: depending on the use-case backend can expose more sound cards and
59 * PCM devices/streams than the underlying HW physically has by employing
60 * SW mixers, configuring virtual sound streams, channels etc.
61 *
62 * This is an example of backend and frontend configuration:
63 *
64 *--------------------------------- Backend -----------------------------------
65 *
66 * /local/domain/0/backend/vsnd/1/0/frontend-id = "1"
67 * /local/domain/0/backend/vsnd/1/0/frontend = "/local/domain/1/device/vsnd/0"
68 * /local/domain/0/backend/vsnd/1/0/state = "4"
69 * /local/domain/0/backend/vsnd/1/0/versions = "1,2"
70 *
71 *--------------------------------- Frontend ----------------------------------
72 *
73 * /local/domain/1/device/vsnd/0/backend-id = "0"
74 * /local/domain/1/device/vsnd/0/backend = "/local/domain/0/backend/vsnd/1/0"
75 * /local/domain/1/device/vsnd/0/state = "4"
76 * /local/domain/1/device/vsnd/0/version = "1"
77 *
78 *----------------------------- Card configuration ----------------------------
79 *
80 * /local/domain/1/device/vsnd/0/short-name = "Card short name"
81 * /local/domain/1/device/vsnd/0/long-name = "Card long name"
82 * /local/domain/1/device/vsnd/0/sample-rates = "8000,32000,44100,48000,96000"
83 * /local/domain/1/device/vsnd/0/sample-formats = "s8,u8,s16_le,s16_be"
84 * /local/domain/1/device/vsnd/0/buffer-size = "262144"
85 *
86 *------------------------------- PCM device 0 --------------------------------
87 *
88 * /local/domain/1/device/vsnd/0/0/name = "General analog"
89 * /local/domain/1/device/vsnd/0/0/channels-max = "5"
90 *
91 *----------------------------- Stream 0, playback ----------------------------
92 *
93 * /local/domain/1/device/vsnd/0/0/0/type = "p"
94 * /local/domain/1/device/vsnd/0/0/0/sample-formats = "s8,u8"
95 * /local/domain/1/device/vsnd/0/0/0/unique-id = "0"
96 *
97 * /local/domain/1/device/vsnd/0/0/0/ring-ref = "386"
98 * /local/domain/1/device/vsnd/0/0/0/event-channel = "15"
99 * /local/domain/1/device/vsnd/0/0/0/evt-ring-ref = "1386"
100 * /local/domain/1/device/vsnd/0/0/0/evt-event-channel = "215"
101 *
102 *------------------------------ Stream 1, capture ----------------------------
103 *
104 * /local/domain/1/device/vsnd/0/0/1/type = "c"
105 * /local/domain/1/device/vsnd/0/0/1/channels-max = "2"
106 * /local/domain/1/device/vsnd/0/0/1/unique-id = "1"
107 *
108 * /local/domain/1/device/vsnd/0/0/1/ring-ref = "384"
109 * /local/domain/1/device/vsnd/0/0/1/event-channel = "13"
110 * /local/domain/1/device/vsnd/0/0/1/evt-ring-ref = "1384"
111 * /local/domain/1/device/vsnd/0/0/1/evt-event-channel = "213"
112 *
113 *------------------------------- PCM device 1 --------------------------------
114 *
115 * /local/domain/1/device/vsnd/0/1/name = "HDMI-0"
116 * /local/domain/1/device/vsnd/0/1/sample-rates = "8000,32000,44100"
117 *
118 *------------------------------ Stream 0, capture ----------------------------
119 *
120 * /local/domain/1/device/vsnd/0/1/0/type = "c"
121 * /local/domain/1/device/vsnd/0/1/0/unique-id = "2"
122 *
123 * /local/domain/1/device/vsnd/0/1/0/ring-ref = "387"
124 * /local/domain/1/device/vsnd/0/1/0/event-channel = "151"
125 * /local/domain/1/device/vsnd/0/1/0/evt-ring-ref = "1387"
126 * /local/domain/1/device/vsnd/0/1/0/evt-event-channel = "351"
127 *
128 *------------------------------- PCM device 2 --------------------------------
129 *
130 * /local/domain/1/device/vsnd/0/2/name = "SPDIF"
131 *
132 *----------------------------- Stream 0, playback ----------------------------
133 *
134 * /local/domain/1/device/vsnd/0/2/0/type = "p"
135 * /local/domain/1/device/vsnd/0/2/0/unique-id = "3"
136 *
137 * /local/domain/1/device/vsnd/0/2/0/ring-ref = "389"
138 * /local/domain/1/device/vsnd/0/2/0/event-channel = "152"
139 * /local/domain/1/device/vsnd/0/2/0/evt-ring-ref = "1389"
140 * /local/domain/1/device/vsnd/0/2/0/evt-event-channel = "452"
141 *
142 ******************************************************************************
143 * Backend XenBus Nodes
144 ******************************************************************************
145 *
146 *----------------------------- Protocol version ------------------------------
147 *
148 * versions
149 * Values: <string>
150 *
151 * List of XENSND_LIST_SEPARATOR separated protocol versions supported
152 * by the backend. For example "1,2,3".
153 *
154 ******************************************************************************
155 * Frontend XenBus Nodes
156 ******************************************************************************
157 *
158 *-------------------------------- Addressing ---------------------------------
159 *
160 * dom-id
161 * Values: <uint16_t>
162 *
163 * Domain identifier.
164 *
165 * dev-id
166 * Values: <uint16_t>
167 *
168 * Device identifier.
169 *
170 * pcm-dev-idx
171 * Values: <uint8_t>
172 *
173 * Zero based contigous index of the PCM device.
174 *
175 * stream-idx
176 * Values: <uint8_t>
177 *
178 * Zero based contigous index of the stream of the PCM device.
179 *
180 * The following pattern is used for addressing:
181 * /local/domain/<dom-id>/device/vsnd/<dev-id>/<pcm-dev-idx>/<stream-idx>/...
182 *
183 *----------------------------- Protocol version ------------------------------
184 *
185 * version
186 * Values: <string>
187 *
188 * Protocol version, chosen among the ones supported by the backend.
189 *
190 *------------------------------- PCM settings --------------------------------
191 *
192 * Every virtualized sound frontend has a set of PCM devices and streams, each
193 * could be individually configured. Part of the PCM configuration can be
194 * defined at higher level of the hierarchy and be fully or partially re-used
195 * by the underlying layers. These configuration values are:
196 * o number of channels (min/max)
197 * o supported sample rates
198 * o supported sample formats.
199 * E.g. one can define these values for the whole card, device or stream.
200 * Every underlying layer in turn can re-define some or all of them to better
201 * fit its needs. For example, card may define number of channels to be
202 * in [1; 8] range, and some particular stream may be limited to [1; 2] only.
203 * The rule is that the underlying layer must be a subset of the upper layer
204 * range.
205 *
206 * channels-min
207 * Values: <uint8_t>
208 *
209 * The minimum amount of channels that is supported, [1; channels-max].
210 * Optional, if not set or omitted a value of 1 is used.
211 *
212 * channels-max
213 * Values: <uint8_t>
214 *
215 * The maximum amount of channels that is supported.
216 * Must be at least <channels-min>.
217 *
218 * sample-rates
219 * Values: <list of uint32_t>
220 *
221 * List of supported sample rates separated by XENSND_LIST_SEPARATOR.
222 * Sample rates are expressed as a list of decimal values w/o any
223 * ordering requirement.
224 *
225 * sample-formats
226 * Values: <list of XENSND_PCM_FORMAT_XXX_STR>
227 *
228 * List of supported sample formats separated by XENSND_LIST_SEPARATOR.
229 * Items must not exceed XENSND_SAMPLE_FORMAT_MAX_LEN length.
230 *
231 * buffer-size
232 * Values: <uint32_t>
233 *
234 * The maximum size in octets of the buffer to allocate per stream.
235 *
236 *----------------------- Virtual sound card settings -------------------------
237 * short-name
238 * Values: <char[32]>
239 *
240 * Short name of the virtual sound card. Optional.
241 *
242 * long-name
243 * Values: <char[80]>
244 *
245 * Long name of the virtual sound card. Optional.
246 *
247 *----------------------------- Device settings -------------------------------
248 * name
249 * Values: <char[80]>
250 *
251 * Name of the sound device within the virtual sound card. Optional.
252 *
253 *----------------------------- Stream settings -------------------------------
254 *
255 * type
256 * Values: "p", "c"
257 *
258 * Stream type: "p" - playback stream, "c" - capture stream
259 *
260 * If both capture and playback are needed then two streams need to be
261 * defined under the same device.
262 *
263 * unique-id
264 * Values: <string>
265 *
266 * After stream initialization it is assigned a unique ID, so every
267 * stream of the frontend can be identified by the backend by this ID.
268 * This can be UUID or such.
269 *
270 *-------------------- Stream Request Transport Parameters --------------------
271 *
272 * event-channel
273 * Values: <uint32_t>
274 *
275 * The identifier of the Xen event channel used to signal activity
276 * in the ring buffer.
277 *
278 * ring-ref
279 * Values: <uint32_t>
280 *
281 * The Xen grant reference granting permission for the backend to map
282 * a sole page in a single page sized ring buffer.
283 *
284 *--------------------- Stream Event Transport Parameters ---------------------
285 *
286 * This communication path is used to deliver asynchronous events from backend
287 * to frontend, set up per stream.
288 *
289 * evt-event-channel
290 * Values: <uint32_t>
291 *
292 * The identifier of the Xen event channel used to signal activity
293 * in the ring buffer.
294 *
295 * evt-ring-ref
296 * Values: <uint32_t>
297 *
298 * The Xen grant reference granting permission for the backend to map
299 * a sole page in a single page sized ring buffer.
300 *
301 ******************************************************************************
302 * STATE DIAGRAMS
303 ******************************************************************************
304 *
305 * Tool stack creates front and back state nodes with initial state
306 * XenbusStateInitialising.
307 * Tool stack creates and sets up frontend sound configuration nodes per domain.
308 *
309 * Front Back
310 * ================================= =====================================
311 * XenbusStateInitialising XenbusStateInitialising
312 * o Query backend device identification
313 * data.
314 * o Open and validate backend device.
315 * |
316 * |
317 * V
318 * XenbusStateInitWait
319 *
320 * o Query frontend configuration
321 * o Allocate and initialize
322 * event channels per configured
323 * playback/capture stream.
324 * o Publish transport parameters
325 * that will be in effect during
326 * this connection.
327 * |
328 * |
329 * V
330 * XenbusStateInitialised
331 *
332 * o Query frontend transport parameters.
333 * o Connect to the event channels.
334 * |
335 * |
336 * V
337 * XenbusStateConnected
338 *
339 * o Create and initialize OS
340 * virtual sound device instances
341 * as per configuration.
342 * |
343 * |
344 * V
345 * XenbusStateConnected
346 *
347 * XenbusStateUnknown
348 * XenbusStateClosed
349 * XenbusStateClosing
350 * o Remove virtual sound device
351 * o Remove event channels
352 * |
353 * |
354 * V
355 * XenbusStateClosed
356 *
357 *------------------------------- Recovery flow -------------------------------
358 *
359 * In case of frontend unrecoverable errors backend handles that as
360 * if frontend goes into the XenbusStateClosed state.
361 *
362 * In case of backend unrecoverable errors frontend tries removing
363 * the virtualized device. If this is possible at the moment of error,
364 * then frontend goes into the XenbusStateInitialising state and is ready for
365 * new connection with backend. If the virtualized device is still in use and
366 * cannot be removed, then frontend goes into the XenbusStateReconfiguring state
367 * until either the virtualized device removed or backend initiates a new
368 * connection. On the virtualized device removal frontend goes into the
369 * XenbusStateInitialising state.
370 *
371 * Note on XenbusStateReconfiguring state of the frontend: if backend has
372 * unrecoverable errors then frontend cannot send requests to the backend
373 * and thus cannot provide functionality of the virtualized device anymore.
374 * After backend is back to normal the virtualized device may still hold some
375 * state: configuration in use, allocated buffers, client application state etc.
376 * So, in most cases, this will require frontend to implement complex recovery
377 * reconnect logic. Instead, by going into XenbusStateReconfiguring state,
378 * frontend will make sure no new clients of the virtualized device are
379 * accepted, allow existing client(s) to exit gracefully by signaling error
380 * state etc.
381 * Once all the clients are gone frontend can reinitialize the virtualized
382 * device and get into XenbusStateInitialising state again signaling the
383 * backend that a new connection can be made.
384 *
385 * There are multiple conditions possible under which frontend will go from
386 * XenbusStateReconfiguring into XenbusStateInitialising, some of them are OS
387 * specific. For example:
388 * 1. The underlying OS framework may provide callbacks to signal that the last
389 * client of the virtualized device has gone and the device can be removed
390 * 2. Frontend can schedule a deferred work (timer/tasklet/workqueue)
391 * to periodically check if this is the right time to re-try removal of
392 * the virtualized device.
393 * 3. By any other means.
394 *
395 ******************************************************************************
396 * PCM FORMATS
397 ******************************************************************************
398 *
399 * XENSND_PCM_FORMAT_<format>[_<endian>]
400 *
401 * format: <S/U/F><bits> or <name>
402 * S - signed, U - unsigned, F - float
403 * bits - 8, 16, 24, 32
404 * name - MU_LAW, GSM, etc.
405 *
406 * endian: <LE/BE>, may be absent
407 * LE - Little endian, BE - Big endian
408 */
409#define XENSND_PCM_FORMAT_S8 0
410#define XENSND_PCM_FORMAT_U8 1
411#define XENSND_PCM_FORMAT_S16_LE 2
412#define XENSND_PCM_FORMAT_S16_BE 3
413#define XENSND_PCM_FORMAT_U16_LE 4
414#define XENSND_PCM_FORMAT_U16_BE 5
415#define XENSND_PCM_FORMAT_S24_LE 6
416#define XENSND_PCM_FORMAT_S24_BE 7
417#define XENSND_PCM_FORMAT_U24_LE 8
418#define XENSND_PCM_FORMAT_U24_BE 9
419#define XENSND_PCM_FORMAT_S32_LE 10
420#define XENSND_PCM_FORMAT_S32_BE 11
421#define XENSND_PCM_FORMAT_U32_LE 12
422#define XENSND_PCM_FORMAT_U32_BE 13
423#define XENSND_PCM_FORMAT_F32_LE 14 /* 4-byte float, IEEE-754 32-bit, */
424#define XENSND_PCM_FORMAT_F32_BE 15 /* range -1.0 to 1.0 */
425#define XENSND_PCM_FORMAT_F64_LE 16 /* 8-byte float, IEEE-754 64-bit, */
426#define XENSND_PCM_FORMAT_F64_BE 17 /* range -1.0 to 1.0 */
427#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE 18
428#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE 19
429#define XENSND_PCM_FORMAT_MU_LAW 20
430#define XENSND_PCM_FORMAT_A_LAW 21
431#define XENSND_PCM_FORMAT_IMA_ADPCM 22
432#define XENSND_PCM_FORMAT_MPEG 23
433#define XENSND_PCM_FORMAT_GSM 24
434
435/*
436 ******************************************************************************
437 * REQUEST CODES
438 ******************************************************************************
439 */
440#define XENSND_OP_OPEN 0
441#define XENSND_OP_CLOSE 1
442#define XENSND_OP_READ 2
443#define XENSND_OP_WRITE 3
444#define XENSND_OP_SET_VOLUME 4
445#define XENSND_OP_GET_VOLUME 5
446#define XENSND_OP_MUTE 6
447#define XENSND_OP_UNMUTE 7
448#define XENSND_OP_TRIGGER 8
449#define XENSND_OP_HW_PARAM_QUERY 9
450
451#define XENSND_OP_TRIGGER_START 0
452#define XENSND_OP_TRIGGER_PAUSE 1
453#define XENSND_OP_TRIGGER_STOP 2
454#define XENSND_OP_TRIGGER_RESUME 3
455
456/*
457 ******************************************************************************
458 * EVENT CODES
459 ******************************************************************************
460 */
461#define XENSND_EVT_CUR_POS 0
462
463/*
464 ******************************************************************************
465 * XENSTORE FIELD AND PATH NAME STRINGS, HELPERS
466 ******************************************************************************
467 */
468#define XENSND_DRIVER_NAME "vsnd"
469
470#define XENSND_LIST_SEPARATOR ","
471/* Field names */
472#define XENSND_FIELD_BE_VERSIONS "versions"
473#define XENSND_FIELD_FE_VERSION "version"
474#define XENSND_FIELD_VCARD_SHORT_NAME "short-name"
475#define XENSND_FIELD_VCARD_LONG_NAME "long-name"
476#define XENSND_FIELD_RING_REF "ring-ref"
477#define XENSND_FIELD_EVT_CHNL "event-channel"
478#define XENSND_FIELD_EVT_RING_REF "evt-ring-ref"
479#define XENSND_FIELD_EVT_EVT_CHNL "evt-event-channel"
480#define XENSND_FIELD_DEVICE_NAME "name"
481#define XENSND_FIELD_TYPE "type"
482#define XENSND_FIELD_STREAM_UNIQUE_ID "unique-id"
483#define XENSND_FIELD_CHANNELS_MIN "channels-min"
484#define XENSND_FIELD_CHANNELS_MAX "channels-max"
485#define XENSND_FIELD_SAMPLE_RATES "sample-rates"
486#define XENSND_FIELD_SAMPLE_FORMATS "sample-formats"
487#define XENSND_FIELD_BUFFER_SIZE "buffer-size"
488
489/* Stream type field values. */
490#define XENSND_STREAM_TYPE_PLAYBACK "p"
491#define XENSND_STREAM_TYPE_CAPTURE "c"
492/* Sample rate max string length */
493#define XENSND_SAMPLE_RATE_MAX_LEN 11
494/* Sample format field values */
495#define XENSND_SAMPLE_FORMAT_MAX_LEN 24
496
497#define XENSND_PCM_FORMAT_S8_STR "s8"
498#define XENSND_PCM_FORMAT_U8_STR "u8"
499#define XENSND_PCM_FORMAT_S16_LE_STR "s16_le"
500#define XENSND_PCM_FORMAT_S16_BE_STR "s16_be"
501#define XENSND_PCM_FORMAT_U16_LE_STR "u16_le"
502#define XENSND_PCM_FORMAT_U16_BE_STR "u16_be"
503#define XENSND_PCM_FORMAT_S24_LE_STR "s24_le"
504#define XENSND_PCM_FORMAT_S24_BE_STR "s24_be"
505#define XENSND_PCM_FORMAT_U24_LE_STR "u24_le"
506#define XENSND_PCM_FORMAT_U24_BE_STR "u24_be"
507#define XENSND_PCM_FORMAT_S32_LE_STR "s32_le"
508#define XENSND_PCM_FORMAT_S32_BE_STR "s32_be"
509#define XENSND_PCM_FORMAT_U32_LE_STR "u32_le"
510#define XENSND_PCM_FORMAT_U32_BE_STR "u32_be"
511#define XENSND_PCM_FORMAT_F32_LE_STR "float_le"
512#define XENSND_PCM_FORMAT_F32_BE_STR "float_be"
513#define XENSND_PCM_FORMAT_F64_LE_STR "float64_le"
514#define XENSND_PCM_FORMAT_F64_BE_STR "float64_be"
515#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE_STR "iec958_subframe_le"
516#define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE_STR "iec958_subframe_be"
517#define XENSND_PCM_FORMAT_MU_LAW_STR "mu_law"
518#define XENSND_PCM_FORMAT_A_LAW_STR "a_law"
519#define XENSND_PCM_FORMAT_IMA_ADPCM_STR "ima_adpcm"
520#define XENSND_PCM_FORMAT_MPEG_STR "mpeg"
521#define XENSND_PCM_FORMAT_GSM_STR "gsm"
522
523
524/*
525 ******************************************************************************
526 * STATUS RETURN CODES
527 ******************************************************************************
528 *
529 * Status return code is zero on success and -XEN_EXX on failure.
530 *
531 ******************************************************************************
532 * Assumptions
533 ******************************************************************************
534 * o usage of grant reference 0 as invalid grant reference:
535 * grant reference 0 is valid, but never exposed to a PV driver,
536 * because of the fact it is already in use/reserved by the PV console.
537 * o all references in this document to page sizes must be treated
538 * as pages of size XEN_PAGE_SIZE unless otherwise noted.
539 *
540 ******************************************************************************
541 * Description of the protocol between frontend and backend driver
542 ******************************************************************************
543 *
544 * The two halves of a Para-virtual sound driver communicate with
545 * each other using shared pages and event channels.
546 * Shared page contains a ring with request/response packets.
547 *
548 * Packets, used for input/output operations, e.g. read/write, set/get volume,
549 * etc., provide offset/length fields in order to allow asynchronous protocol
550 * operation with buffer space sharing: part of the buffer allocated at
551 * XENSND_OP_OPEN can be used for audio samples and part, for example,
552 * for volume control.
553 *
554 * All reserved fields in the structures below must be 0.
555 *
556 *---------------------------------- Requests ---------------------------------
557 *
558 * All request packets have the same length (64 octets)
559 * All request packets have common header:
560 * 0 1 2 3 octet
561 * +----------------+----------------+----------------+----------------+
562 * | id | operation | reserved | 4
563 * +----------------+----------------+----------------+----------------+
564 * | reserved | 8
565 * +----------------+----------------+----------------+----------------+
566 * id - uint16_t, private guest value, echoed in response
567 * operation - uint8_t, operation code, XENSND_OP_???
568 *
569 * For all packets which use offset and length:
570 * offset - uint32_t, read or write data offset within the shared buffer,
571 * passed with XENSND_OP_OPEN request, octets,
572 * [0; XENSND_OP_OPEN.buffer_sz - 1].
573 * length - uint32_t, read or write data length, octets
574 *
575 * Request open - open a PCM stream for playback or capture:
576 *
577 * 0 1 2 3 octet
578 * +----------------+----------------+----------------+----------------+
579 * | id | XENSND_OP_OPEN | reserved | 4
580 * +----------------+----------------+----------------+----------------+
581 * | reserved | 8
582 * +----------------+----------------+----------------+----------------+
583 * | pcm_rate | 12
584 * +----------------+----------------+----------------+----------------+
585 * | pcm_format | pcm_channels | reserved | 16
586 * +----------------+----------------+----------------+----------------+
587 * | buffer_sz | 20
588 * +----------------+----------------+----------------+----------------+
589 * | gref_directory | 24
590 * +----------------+----------------+----------------+----------------+
591 * | period_sz | 28
592 * +----------------+----------------+----------------+----------------+
593 * | reserved | 32
594 * +----------------+----------------+----------------+----------------+
595 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
596 * +----------------+----------------+----------------+----------------+
597 * | reserved | 64
598 * +----------------+----------------+----------------+----------------+
599 *
600 * pcm_rate - uint32_t, stream data rate, Hz
601 * pcm_format - uint8_t, XENSND_PCM_FORMAT_XXX value
602 * pcm_channels - uint8_t, number of channels of this stream,
603 * [channels-min; channels-max]
604 * buffer_sz - uint32_t, buffer size to be allocated, octets
605 * period_sz - uint32_t, event period size, octets
606 * This is the requested value of the period at which frontend would
607 * like to receive XENSND_EVT_CUR_POS notifications from the backend when
608 * stream position advances during playback/capture.
609 * It shows how many octets are expected to be played/captured before
610 * sending such an event.
611 * If set to 0 no XENSND_EVT_CUR_POS events are sent by the backend.
612 *
613 * gref_directory - grant_ref_t, a reference to the first shared page
614 * describing shared buffer references. At least one page exists. If shared
615 * buffer size (buffer_sz) exceeds what can be addressed by this single page,
616 * then reference to the next page must be supplied (see gref_dir_next_page
617 * below)
618 */
619
620struct xensnd_open_req {
621 uint32_t pcm_rate;
622 uint8_t pcm_format;
623 uint8_t pcm_channels;
624 uint16_t reserved;
625 uint32_t buffer_sz;
626 grant_ref_t gref_directory;
627 uint32_t period_sz;
628};
629
630/*
631 * Shared page for XENSND_OP_OPEN buffer descriptor (gref_directory in the
632 * request) employs a list of pages, describing all pages of the shared data
633 * buffer:
634 * 0 1 2 3 octet
635 * +----------------+----------------+----------------+----------------+
636 * | gref_dir_next_page | 4
637 * +----------------+----------------+----------------+----------------+
638 * | gref[0] | 8
639 * +----------------+----------------+----------------+----------------+
640 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
641 * +----------------+----------------+----------------+----------------+
642 * | gref[i] | i*4+8
643 * +----------------+----------------+----------------+----------------+
644 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
645 * +----------------+----------------+----------------+----------------+
646 * | gref[N - 1] | N*4+8
647 * +----------------+----------------+----------------+----------------+
648 *
649 * gref_dir_next_page - grant_ref_t, reference to the next page describing
650 * page directory. Must be 0 if there are no more pages in the list.
651 * gref[i] - grant_ref_t, reference to a shared page of the buffer
652 * allocated at XENSND_OP_OPEN
653 *
654 * Number of grant_ref_t entries in the whole page directory is not
655 * passed, but instead can be calculated as:
656 * num_grefs_total = (XENSND_OP_OPEN.buffer_sz + XEN_PAGE_SIZE - 1) /
657 * XEN_PAGE_SIZE
658 */
659
660struct xensnd_page_directory {
661 grant_ref_t gref_dir_next_page;
662 grant_ref_t gref[];
663};
664
665/*
666 * Request close - close an opened pcm stream:
667 * 0 1 2 3 octet
668 * +----------------+----------------+----------------+----------------+
669 * | id | XENSND_OP_CLOSE| reserved | 4
670 * +----------------+----------------+----------------+----------------+
671 * | reserved | 8
672 * +----------------+----------------+----------------+----------------+
673 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
674 * +----------------+----------------+----------------+----------------+
675 * | reserved | 64
676 * +----------------+----------------+----------------+----------------+
677 *
678 * Request read/write - used for read (for capture) or write (for playback):
679 * 0 1 2 3 octet
680 * +----------------+----------------+----------------+----------------+
681 * | id | operation | reserved | 4
682 * +----------------+----------------+----------------+----------------+
683 * | reserved | 8
684 * +----------------+----------------+----------------+----------------+
685 * | offset | 12
686 * +----------------+----------------+----------------+----------------+
687 * | length | 16
688 * +----------------+----------------+----------------+----------------+
689 * | reserved | 20
690 * +----------------+----------------+----------------+----------------+
691 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
692 * +----------------+----------------+----------------+----------------+
693 * | reserved | 64
694 * +----------------+----------------+----------------+----------------+
695 *
696 * operation - XENSND_OP_READ for read or XENSND_OP_WRITE for write
697 */
698
699struct xensnd_rw_req {
700 uint32_t offset;
701 uint32_t length;
702};
703
704/*
705 * Request set/get volume - set/get channels' volume of the stream given:
706 * 0 1 2 3 octet
707 * +----------------+----------------+----------------+----------------+
708 * | id | operation | reserved | 4
709 * +----------------+----------------+----------------+----------------+
710 * | reserved | 8
711 * +----------------+----------------+----------------+----------------+
712 * | offset | 12
713 * +----------------+----------------+----------------+----------------+
714 * | length | 16
715 * +----------------+----------------+----------------+----------------+
716 * | reserved | 20
717 * +----------------+----------------+----------------+----------------+
718 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
719 * +----------------+----------------+----------------+----------------+
720 * | reserved | 64
721 * +----------------+----------------+----------------+----------------+
722 *
723 * operation - XENSND_OP_SET_VOLUME for volume set
724 * or XENSND_OP_GET_VOLUME for volume get
725 * Buffer passed with XENSND_OP_OPEN is used to exchange volume
726 * values:
727 *
728 * 0 1 2 3 octet
729 * +----------------+----------------+----------------+----------------+
730 * | channel[0] | 4
731 * +----------------+----------------+----------------+----------------+
732 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
733 * +----------------+----------------+----------------+----------------+
734 * | channel[i] | i*4
735 * +----------------+----------------+----------------+----------------+
736 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
737 * +----------------+----------------+----------------+----------------+
738 * | channel[N - 1] | (N-1)*4
739 * +----------------+----------------+----------------+----------------+
740 *
741 * N = XENSND_OP_OPEN.pcm_channels
742 * i - uint8_t, index of a channel
743 * channel[i] - sint32_t, volume of i-th channel
744 * Volume is expressed as a signed value in steps of 0.001 dB,
745 * while 0 being 0 dB.
746 *
747 * Request mute/unmute - mute/unmute stream:
748 * 0 1 2 3 octet
749 * +----------------+----------------+----------------+----------------+
750 * | id | operation | reserved | 4
751 * +----------------+----------------+----------------+----------------+
752 * | reserved | 8
753 * +----------------+----------------+----------------+----------------+
754 * | offset | 12
755 * +----------------+----------------+----------------+----------------+
756 * | length | 16
757 * +----------------+----------------+----------------+----------------+
758 * | reserved | 20
759 * +----------------+----------------+----------------+----------------+
760 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
761 * +----------------+----------------+----------------+----------------+
762 * | reserved | 64
763 * +----------------+----------------+----------------+----------------+
764 *
765 * operation - XENSND_OP_MUTE for mute or XENSND_OP_UNMUTE for unmute
766 * Buffer passed with XENSND_OP_OPEN is used to exchange mute/unmute
767 * values:
768 *
769 * 0 octet
770 * +----------------+----------------+----------------+----------------+
771 * | channel[0] | 4
772 * +----------------+----------------+----------------+----------------+
773 * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
774 * +----------------+----------------+----------------+----------------+
775 * | channel[i] | i*4
776 * +----------------+----------------+----------------+----------------+
777 * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
778 * +----------------+----------------+----------------+----------------+
779 * | channel[N - 1] | (N-1)*4
780 * +----------------+----------------+----------------+----------------+
781 *
782 * N = XENSND_OP_OPEN.pcm_channels
783 * i - uint8_t, index of a channel
784 * channel[i] - uint8_t, non-zero if i-th channel needs to be muted/unmuted
785 *
786 *------------------------------------ N.B. -----------------------------------
787 *
788 * The 'struct xensnd_rw_req' is also used for XENSND_OP_SET_VOLUME,
789 * XENSND_OP_GET_VOLUME, XENSND_OP_MUTE, XENSND_OP_UNMUTE.
790 *
791 * Request stream running state change - trigger PCM stream running state
792 * to start, stop, pause or resume:
793 *
794 * 0 1 2 3 octet
795 * +----------------+----------------+----------------+----------------+
796 * | id | _OP_TRIGGER | reserved | 4
797 * +----------------+----------------+----------------+----------------+
798 * | reserved | 8
799 * +----------------+----------------+----------------+----------------+
800 * | type | reserved | 12
801 * +----------------+----------------+----------------+----------------+
802 * | reserved | 16
803 * +----------------+----------------+----------------+----------------+
804 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
805 * +----------------+----------------+----------------+----------------+
806 * | reserved | 64
807 * +----------------+----------------+----------------+----------------+
808 *
809 * type - uint8_t, XENSND_OP_TRIGGER_XXX value
810 */
811
812struct xensnd_trigger_req {
813 uint8_t type;
814};
815
816/*
817 * Request stream parameter ranges: request intervals and
818 * masks of supported ranges for stream configuration values.
819 *
820 * Sound device configuration for a particular stream is a limited subset
821 * of the multidimensional configuration available on XenStore, e.g.
822 * once the frame rate has been selected there is a limited supported range
823 * for sample rates becomes available (which might be the same set configured
824 * on XenStore or less). For example, selecting 96kHz sample rate may limit
825 * number of channels available for such configuration from 4 to 2, etc.
826 * Thus, each call to XENSND_OP_HW_PARAM_QUERY may reduce configuration
827 * space making it possible to iteratively get the final stream configuration,
828 * used in XENSND_OP_OPEN request.
829 *
830 * See response format for this request.
831 *
832 * 0 1 2 3 octet
833 * +----------------+----------------+----------------+----------------+
834 * | id | _HW_PARAM_QUERY| reserved | 4
835 * +----------------+----------------+----------------+----------------+
836 * | reserved | 8
837 * +----------------+----------------+----------------+----------------+
838 * | formats mask low 32-bit | 12
839 * +----------------+----------------+----------------+----------------+
840 * | formats mask high 32-bit | 16
841 * +----------------+----------------+----------------+----------------+
842 * | min rate | 20
843 * +----------------+----------------+----------------+----------------+
844 * | max rate | 24
845 * +----------------+----------------+----------------+----------------+
846 * | min channels | 28
847 * +----------------+----------------+----------------+----------------+
848 * | max channels | 32
849 * +----------------+----------------+----------------+----------------+
850 * | min buffer frames | 36
851 * +----------------+----------------+----------------+----------------+
852 * | max buffer frames | 40
853 * +----------------+----------------+----------------+----------------+
854 * | min period frames | 44
855 * +----------------+----------------+----------------+----------------+
856 * | max period frames | 48
857 * +----------------+----------------+----------------+----------------+
858 * | reserved | 52
859 * +----------------+----------------+----------------+----------------+
860 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
861 * +----------------+----------------+----------------+----------------+
862 * | reserved | 64
863 * +----------------+----------------+----------------+----------------+
864 *
865 * formats - uint64_t, bit mask representing values of the parameter
866 * made as bitwise OR of (1 << XENSND_PCM_FORMAT_XXX) values
867 *
868 * For interval parameters:
869 * min - uint32_t, minimum value of the parameter
870 * max - uint32_t, maximum value of the parameter
871 *
872 * Frame is defined as a product of the number of channels by the
873 * number of octets per one sample.
874 */
875
876struct xensnd_query_hw_param {
877 uint64_t formats;
878 struct {
879 uint32_t min;
880 uint32_t max;
881 } rates;
882 struct {
883 uint32_t min;
884 uint32_t max;
885 } channels;
886 struct {
887 uint32_t min;
888 uint32_t max;
889 } buffer;
890 struct {
891 uint32_t min;
892 uint32_t max;
893 } period;
894};
895
896/*
897 *---------------------------------- Responses --------------------------------
898 *
899 * All response packets have the same length (64 octets)
900 *
901 * All response packets have common header:
902 * 0 1 2 3 octet
903 * +----------------+----------------+----------------+----------------+
904 * | id | operation | reserved | 4
905 * +----------------+----------------+----------------+----------------+
906 * | status | 8
907 * +----------------+----------------+----------------+----------------+
908 *
909 * id - uint16_t, copied from the request
910 * operation - uint8_t, XENSND_OP_* - copied from request
911 * status - int32_t, response status, zero on success and -XEN_EXX on failure
912 *
913 *
914 * HW parameter query response - response for XENSND_OP_HW_PARAM_QUERY:
915 * 0 1 2 3 octet
916 * +----------------+----------------+----------------+----------------+
917 * | id | operation | reserved | 4
918 * +----------------+----------------+----------------+----------------+
919 * | status | 8
920 * +----------------+----------------+----------------+----------------+
921 * | formats mask low 32-bit | 12
922 * +----------------+----------------+----------------+----------------+
923 * | formats mask high 32-bit | 16
924 * +----------------+----------------+----------------+----------------+
925 * | min rate | 20
926 * +----------------+----------------+----------------+----------------+
927 * | max rate | 24
928 * +----------------+----------------+----------------+----------------+
929 * | min channels | 28
930 * +----------------+----------------+----------------+----------------+
931 * | max channels | 32
932 * +----------------+----------------+----------------+----------------+
933 * | min buffer frames | 36
934 * +----------------+----------------+----------------+----------------+
935 * | max buffer frames | 40
936 * +----------------+----------------+----------------+----------------+
937 * | min period frames | 44
938 * +----------------+----------------+----------------+----------------+
939 * | max period frames | 48
940 * +----------------+----------------+----------------+----------------+
941 * | reserved | 52
942 * +----------------+----------------+----------------+----------------+
943 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
944 * +----------------+----------------+----------------+----------------+
945 * | reserved | 64
946 * +----------------+----------------+----------------+----------------+
947 *
948 * Meaning of the values in this response is the same as for
949 * XENSND_OP_HW_PARAM_QUERY request.
950 */
951
952/*
953 *----------------------------------- Events ----------------------------------
954 *
955 * Events are sent via shared page allocated by the front and propagated by
956 * evt-event-channel/evt-ring-ref XenStore entries
957 * All event packets have the same length (64 octets)
958 * All event packets have common header:
959 * 0 1 2 3 octet
960 * +----------------+----------------+----------------+----------------+
961 * | id | type | reserved | 4
962 * +----------------+----------------+----------------+----------------+
963 * | reserved | 8
964 * +----------------+----------------+----------------+----------------+
965 *
966 * id - uint16_t, event id, may be used by front
967 * type - uint8_t, type of the event
968 *
969 *
970 * Current stream position - event from back to front when stream's
971 * playback/capture position has advanced:
972 * 0 1 2 3 octet
973 * +----------------+----------------+----------------+----------------+
974 * | id | _EVT_CUR_POS | reserved | 4
975 * +----------------+----------------+----------------+----------------+
976 * | reserved | 8
977 * +----------------+----------------+----------------+----------------+
978 * | position low 32-bit | 12
979 * +----------------+----------------+----------------+----------------+
980 * | position high 32-bit | 16
981 * +----------------+----------------+----------------+----------------+
982 * | reserved | 20
983 * +----------------+----------------+----------------+----------------+
984 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
985 * +----------------+----------------+----------------+----------------+
986 * | reserved | 64
987 * +----------------+----------------+----------------+----------------+
988 *
989 * position - current value of stream's playback/capture position, octets
990 *
991 */
992
993struct xensnd_cur_pos_evt {
994 uint64_t position;
995};
996
997struct xensnd_req {
998 uint16_t id;
999 uint8_t operation;
1000 uint8_t reserved[5];
1001 union {
1002 struct xensnd_open_req open;
1003 struct xensnd_rw_req rw;
1004 struct xensnd_trigger_req trigger;
1005 struct xensnd_query_hw_param hw_param;
1006 uint8_t reserved[56];
1007 } op;
1008};
1009
1010struct xensnd_resp {
1011 uint16_t id;
1012 uint8_t operation;
1013 uint8_t reserved;
1014 int32_t status;
1015 union {
1016 struct xensnd_query_hw_param hw_param;
1017 uint8_t reserved1[56];
1018 } resp;
1019};
1020
1021struct xensnd_evt {
1022 uint16_t id;
1023 uint8_t type;
1024 uint8_t reserved[5];
1025 union {
1026 struct xensnd_cur_pos_evt cur_pos;
1027 uint8_t reserved[56];
1028 } op;
1029};
1030
1031DEFINE_RING_TYPES(xen_sndif, struct xensnd_req, struct xensnd_resp);
1032
1033/*
1034 ******************************************************************************
1035 * Back to front events delivery
1036 ******************************************************************************
1037 * In order to deliver asynchronous events from back to front a shared page is
1038 * allocated by front and its granted reference propagated to back via
1039 * XenStore entries (evt-ring-ref/evt-event-channel).
1040 * This page has a common header used by both front and back to synchronize
1041 * access and control event's ring buffer, while back being a producer of the
1042 * events and front being a consumer. The rest of the page after the header
1043 * is used for event packets.
1044 *
1045 * Upon reception of an event(s) front may confirm its reception
1046 * for either each event, group of events or none.
1047 */
1048
1049struct xensnd_event_page {
1050 uint32_t in_cons;
1051 uint32_t in_prod;
1052 uint8_t reserved[56];
1053};
1054
1055#define XENSND_EVENT_PAGE_SIZE XEN_PAGE_SIZE
1056#define XENSND_IN_RING_OFFS (sizeof(struct xensnd_event_page))
1057#define XENSND_IN_RING_SIZE (XENSND_EVENT_PAGE_SIZE - XENSND_IN_RING_OFFS)
1058#define XENSND_IN_RING_LEN (XENSND_IN_RING_SIZE / sizeof(struct xensnd_evt))
1059#define XENSND_IN_RING(page) \
1060 ((struct xensnd_evt *)((char *)(page) + XENSND_IN_RING_OFFS))
1061#define XENSND_IN_RING_REF(page, idx) \
1062 (XENSND_IN_RING((page))[(idx) % XENSND_IN_RING_LEN])
1063
1064#endif /* __XEN_PUBLIC_IO_SNDIF_H__ */