1 /* SPDX-License-Identifier: MIT */
2 /******************************************************************************
5 * Unified sound-device I/O interface for Xen guest OSes.
7 * Copyright (C) 2013-2015 GlobalLogic Inc.
8 * Copyright (C) 2016-2017 EPAM Systems Inc.
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>
16 #ifndef __XEN_PUBLIC_IO_SNDIF_H__
17 #define __XEN_PUBLIC_IO_SNDIF_H__
20 #include "../grant_table.h"
23 ******************************************************************************
25 ******************************************************************************
27 #define XENSND_PROTOCOL_VERSION 2
30 ******************************************************************************
31 * Feature and Parameter Negotiation
32 ******************************************************************************
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()).
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()).
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.
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.
54 ******************************************************************************
55 * Example configuration
56 ******************************************************************************
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.
62 * This is an example of backend and frontend configuration:
64 *--------------------------------- Backend -----------------------------------
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"
71 *--------------------------------- Frontend ----------------------------------
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"
78 *----------------------------- Card configuration ----------------------------
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"
86 *------------------------------- PCM device 0 --------------------------------
88 * /local/domain/1/device/vsnd/0/0/name = "General analog"
89 * /local/domain/1/device/vsnd/0/0/channels-max = "5"
91 *----------------------------- Stream 0, playback ----------------------------
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"
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"
102 *------------------------------ Stream 1, capture ----------------------------
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"
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"
113 *------------------------------- PCM device 1 --------------------------------
115 * /local/domain/1/device/vsnd/0/1/name = "HDMI-0"
116 * /local/domain/1/device/vsnd/0/1/sample-rates = "8000,32000,44100"
118 *------------------------------ Stream 0, capture ----------------------------
120 * /local/domain/1/device/vsnd/0/1/0/type = "c"
121 * /local/domain/1/device/vsnd/0/1/0/unique-id = "2"
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"
128 *------------------------------- PCM device 2 --------------------------------
130 * /local/domain/1/device/vsnd/0/2/name = "SPDIF"
132 *----------------------------- Stream 0, playback ----------------------------
134 * /local/domain/1/device/vsnd/0/2/0/type = "p"
135 * /local/domain/1/device/vsnd/0/2/0/unique-id = "3"
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"
142 ******************************************************************************
143 * Backend XenBus Nodes
144 ******************************************************************************
146 *----------------------------- Protocol version ------------------------------
151 * List of XENSND_LIST_SEPARATOR separated protocol versions supported
152 * by the backend. For example "1,2,3".
154 ******************************************************************************
155 * Frontend XenBus Nodes
156 ******************************************************************************
158 *-------------------------------- Addressing ---------------------------------
173 * Zero based contigous index of the PCM device.
178 * Zero based contigous index of the stream of the PCM device.
180 * The following pattern is used for addressing:
181 * /local/domain/<dom-id>/device/vsnd/<dev-id>/<pcm-dev-idx>/<stream-idx>/...
183 *----------------------------- Protocol version ------------------------------
188 * Protocol version, chosen among the ones supported by the backend.
190 *------------------------------- PCM settings --------------------------------
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
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.
215 * The maximum amount of channels that is supported.
216 * Must be at least <channels-min>.
219 * Values: <list of uint32_t>
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.
226 * Values: <list of XENSND_PCM_FORMAT_XXX_STR>
228 * List of supported sample formats separated by XENSND_LIST_SEPARATOR.
229 * Items must not exceed XENSND_SAMPLE_FORMAT_MAX_LEN length.
234 * The maximum size in octets of the buffer to allocate per stream.
236 *----------------------- Virtual sound card settings -------------------------
240 * Short name of the virtual sound card. Optional.
245 * Long name of the virtual sound card. Optional.
247 *----------------------------- Device settings -------------------------------
251 * Name of the sound device within the virtual sound card. Optional.
253 *----------------------------- Stream settings -------------------------------
258 * Stream type: "p" - playback stream, "c" - capture stream
260 * If both capture and playback are needed then two streams need to be
261 * defined under the same device.
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.
270 *-------------------- Stream Request Transport Parameters --------------------
275 * The identifier of the Xen event channel used to signal activity
276 * in the ring buffer.
281 * The Xen grant reference granting permission for the backend to map
282 * a sole page in a single page sized ring buffer.
284 *--------------------- Stream Event Transport Parameters ---------------------
286 * This communication path is used to deliver asynchronous events from backend
287 * to frontend, set up per stream.
292 * The identifier of the Xen event channel used to signal activity
293 * in the ring buffer.
298 * The Xen grant reference granting permission for the backend to map
299 * a sole page in a single page sized ring buffer.
301 ******************************************************************************
303 ******************************************************************************
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.
310 * ================================= =====================================
311 * XenbusStateInitialising XenbusStateInitialising
312 * o Query backend device identification
314 * o Open and validate backend device.
318 * XenbusStateInitWait
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
330 * XenbusStateInitialised
332 * o Query frontend transport parameters.
333 * o Connect to the event channels.
337 * XenbusStateConnected
339 * o Create and initialize OS
340 * virtual sound device instances
341 * as per configuration.
345 * XenbusStateConnected
350 * o Remove virtual sound device
351 * o Remove event channels
357 *------------------------------- Recovery flow -------------------------------
359 * In case of frontend unrecoverable errors backend handles that as
360 * if frontend goes into the XenbusStateClosed state.
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.
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
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.
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.
395 ******************************************************************************
397 ******************************************************************************
399 * XENSND_PCM_FORMAT_<format>[_<endian>]
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.
406 * endian: <LE/BE>, may be absent
407 * LE - Little endian, BE - Big endian
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
436 ******************************************************************************
438 ******************************************************************************
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
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
457 ******************************************************************************
459 ******************************************************************************
461 #define XENSND_EVT_CUR_POS 0
464 ******************************************************************************
465 * XENSTORE FIELD AND PATH NAME STRINGS, HELPERS
466 ******************************************************************************
468 #define XENSND_DRIVER_NAME "vsnd"
470 #define XENSND_LIST_SEPARATOR ","
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"
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
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"
525 ******************************************************************************
526 * STATUS RETURN CODES
527 ******************************************************************************
529 * Status return code is zero on success and -XEN_EXX on failure.
531 ******************************************************************************
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.
540 ******************************************************************************
541 * Description of the protocol between frontend and backend driver
542 ******************************************************************************
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.
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.
554 * All reserved fields in the structures below must be 0.
556 *---------------------------------- Requests ---------------------------------
558 * All request packets have the same length (64 octets)
559 * All request packets have common header:
561 * +----------------+----------------+----------------+----------------+
562 * | id | operation | reserved | 4
563 * +----------------+----------------+----------------+----------------+
565 * +----------------+----------------+----------------+----------------+
566 * id - uint16_t, private guest value, echoed in response
567 * operation - uint8_t, operation code, XENSND_OP_???
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
575 * Request open - open a PCM stream for playback or capture:
578 * +----------------+----------------+----------------+----------------+
579 * | id | XENSND_OP_OPEN | reserved | 4
580 * +----------------+----------------+----------------+----------------+
582 * +----------------+----------------+----------------+----------------+
584 * +----------------+----------------+----------------+----------------+
585 * | pcm_format | pcm_channels | reserved | 16
586 * +----------------+----------------+----------------+----------------+
588 * +----------------+----------------+----------------+----------------+
589 * | gref_directory | 24
590 * +----------------+----------------+----------------+----------------+
592 * +----------------+----------------+----------------+----------------+
594 * +----------------+----------------+----------------+----------------+
595 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
596 * +----------------+----------------+----------------+----------------+
598 * +----------------+----------------+----------------+----------------+
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.
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
620 struct xensnd_open_req {
623 uint8_t pcm_channels;
626 grant_ref_t gref_directory;
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
635 * +----------------+----------------+----------------+----------------+
636 * | gref_dir_next_page | 4
637 * +----------------+----------------+----------------+----------------+
639 * +----------------+----------------+----------------+----------------+
640 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
641 * +----------------+----------------+----------------+----------------+
643 * +----------------+----------------+----------------+----------------+
644 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
645 * +----------------+----------------+----------------+----------------+
646 * | gref[N - 1] | N*4+8
647 * +----------------+----------------+----------------+----------------+
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
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) /
660 struct xensnd_page_directory {
661 grant_ref_t gref_dir_next_page;
662 grant_ref_t gref[1]; /* Variable length */
666 * Request close - close an opened pcm stream:
668 * +----------------+----------------+----------------+----------------+
669 * | id | XENSND_OP_CLOSE| reserved | 4
670 * +----------------+----------------+----------------+----------------+
672 * +----------------+----------------+----------------+----------------+
673 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
674 * +----------------+----------------+----------------+----------------+
676 * +----------------+----------------+----------------+----------------+
678 * Request read/write - used for read (for capture) or write (for playback):
680 * +----------------+----------------+----------------+----------------+
681 * | id | operation | reserved | 4
682 * +----------------+----------------+----------------+----------------+
684 * +----------------+----------------+----------------+----------------+
686 * +----------------+----------------+----------------+----------------+
688 * +----------------+----------------+----------------+----------------+
690 * +----------------+----------------+----------------+----------------+
691 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
692 * +----------------+----------------+----------------+----------------+
694 * +----------------+----------------+----------------+----------------+
696 * operation - XENSND_OP_READ for read or XENSND_OP_WRITE for write
699 struct xensnd_rw_req {
705 * Request set/get volume - set/get channels' volume of the stream given:
707 * +----------------+----------------+----------------+----------------+
708 * | id | operation | reserved | 4
709 * +----------------+----------------+----------------+----------------+
711 * +----------------+----------------+----------------+----------------+
713 * +----------------+----------------+----------------+----------------+
715 * +----------------+----------------+----------------+----------------+
717 * +----------------+----------------+----------------+----------------+
718 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
719 * +----------------+----------------+----------------+----------------+
721 * +----------------+----------------+----------------+----------------+
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
729 * +----------------+----------------+----------------+----------------+
731 * +----------------+----------------+----------------+----------------+
732 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
733 * +----------------+----------------+----------------+----------------+
735 * +----------------+----------------+----------------+----------------+
736 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
737 * +----------------+----------------+----------------+----------------+
738 * | channel[N - 1] | (N-1)*4
739 * +----------------+----------------+----------------+----------------+
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.
747 * Request mute/unmute - mute/unmute stream:
749 * +----------------+----------------+----------------+----------------+
750 * | id | operation | reserved | 4
751 * +----------------+----------------+----------------+----------------+
753 * +----------------+----------------+----------------+----------------+
755 * +----------------+----------------+----------------+----------------+
757 * +----------------+----------------+----------------+----------------+
759 * +----------------+----------------+----------------+----------------+
760 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
761 * +----------------+----------------+----------------+----------------+
763 * +----------------+----------------+----------------+----------------+
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
770 * +----------------+----------------+----------------+----------------+
772 * +----------------+----------------+----------------+----------------+
773 * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
774 * +----------------+----------------+----------------+----------------+
776 * +----------------+----------------+----------------+----------------+
777 * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
778 * +----------------+----------------+----------------+----------------+
779 * | channel[N - 1] | (N-1)*4
780 * +----------------+----------------+----------------+----------------+
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
786 *------------------------------------ N.B. -----------------------------------
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.
791 * Request stream running state change - trigger PCM stream running state
792 * to start, stop, pause or resume:
795 * +----------------+----------------+----------------+----------------+
796 * | id | _OP_TRIGGER | reserved | 4
797 * +----------------+----------------+----------------+----------------+
799 * +----------------+----------------+----------------+----------------+
800 * | type | reserved | 12
801 * +----------------+----------------+----------------+----------------+
803 * +----------------+----------------+----------------+----------------+
804 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
805 * +----------------+----------------+----------------+----------------+
807 * +----------------+----------------+----------------+----------------+
809 * type - uint8_t, XENSND_OP_TRIGGER_XXX value
812 struct xensnd_trigger_req {
817 * Request stream parameter ranges: request intervals and
818 * masks of supported ranges for stream configuration values.
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.
830 * See response format for this request.
833 * +----------------+----------------+----------------+----------------+
834 * | id | _HW_PARAM_QUERY| reserved | 4
835 * +----------------+----------------+----------------+----------------+
837 * +----------------+----------------+----------------+----------------+
838 * | formats mask low 32-bit | 12
839 * +----------------+----------------+----------------+----------------+
840 * | formats mask high 32-bit | 16
841 * +----------------+----------------+----------------+----------------+
843 * +----------------+----------------+----------------+----------------+
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 * +----------------+----------------+----------------+----------------+
859 * +----------------+----------------+----------------+----------------+
860 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
861 * +----------------+----------------+----------------+----------------+
863 * +----------------+----------------+----------------+----------------+
865 * formats - uint64_t, bit mask representing values of the parameter
866 * made as bitwise OR of (1 << XENSND_PCM_FORMAT_XXX) values
868 * For interval parameters:
869 * min - uint32_t, minimum value of the parameter
870 * max - uint32_t, maximum value of the parameter
872 * Frame is defined as a product of the number of channels by the
873 * number of octets per one sample.
876 struct xensnd_query_hw_param {
897 *---------------------------------- Responses --------------------------------
899 * All response packets have the same length (64 octets)
901 * All response packets have common header:
903 * +----------------+----------------+----------------+----------------+
904 * | id | operation | reserved | 4
905 * +----------------+----------------+----------------+----------------+
907 * +----------------+----------------+----------------+----------------+
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
914 * HW parameter query response - response for XENSND_OP_HW_PARAM_QUERY:
916 * +----------------+----------------+----------------+----------------+
917 * | id | operation | reserved | 4
918 * +----------------+----------------+----------------+----------------+
920 * +----------------+----------------+----------------+----------------+
921 * | formats mask low 32-bit | 12
922 * +----------------+----------------+----------------+----------------+
923 * | formats mask high 32-bit | 16
924 * +----------------+----------------+----------------+----------------+
926 * +----------------+----------------+----------------+----------------+
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 * +----------------+----------------+----------------+----------------+
942 * +----------------+----------------+----------------+----------------+
943 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
944 * +----------------+----------------+----------------+----------------+
946 * +----------------+----------------+----------------+----------------+
948 * Meaning of the values in this response is the same as for
949 * XENSND_OP_HW_PARAM_QUERY request.
953 *----------------------------------- Events ----------------------------------
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:
960 * +----------------+----------------+----------------+----------------+
961 * | id | type | reserved | 4
962 * +----------------+----------------+----------------+----------------+
964 * +----------------+----------------+----------------+----------------+
966 * id - uint16_t, event id, may be used by front
967 * type - uint8_t, type of the event
970 * Current stream position - event from back to front when stream's
971 * playback/capture position has advanced:
973 * +----------------+----------------+----------------+----------------+
974 * | id | _EVT_CUR_POS | reserved | 4
975 * +----------------+----------------+----------------+----------------+
977 * +----------------+----------------+----------------+----------------+
978 * | position low 32-bit | 12
979 * +----------------+----------------+----------------+----------------+
980 * | position high 32-bit | 16
981 * +----------------+----------------+----------------+----------------+
983 * +----------------+----------------+----------------+----------------+
984 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
985 * +----------------+----------------+----------------+----------------+
987 * +----------------+----------------+----------------+----------------+
989 * position - current value of stream's playback/capture position, octets
993 struct xensnd_cur_pos_evt {
1000 uint8_t reserved[5];
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];
1010 struct xensnd_resp {
1016 struct xensnd_query_hw_param hw_param;
1017 uint8_t reserved1[56];
1024 uint8_t reserved[5];
1026 struct xensnd_cur_pos_evt cur_pos;
1027 uint8_t reserved[56];
1031 DEFINE_RING_TYPES(xen_sndif, struct xensnd_req, struct xensnd_resp);
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.
1045 * Upon reception of an event(s) front may confirm its reception
1046 * for either each event, group of events or none.
1049 struct xensnd_event_page {
1052 uint8_t reserved[56];
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])
1064 #endif /* __XEN_PUBLIC_IO_SNDIF_H__ */