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 */ 619 620 struct 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 */ 659 660 struct 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 */ 698 699 struct 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 */ 811 812 struct 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 */ 875 876 struct 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 */ 992 993 struct xensnd_cur_pos_evt { 994 uint64_t position; 995 }; 996 997 struct 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 1010 struct 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 1021 struct 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 1031 DEFINE_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 1049 struct 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__ */ 1065