| /****************************************************************************** |
| * sndif.h |
| * |
| * Unified sound-device I/O interface for Xen guest OSes. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to |
| * deal in the Software without restriction, including without limitation the |
| * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or |
| * sell copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| * DEALINGS IN THE SOFTWARE. |
| * |
| * Copyright (C) 2013-2015 GlobalLogic Inc. |
| * Copyright (C) 2016-2017 EPAM Systems Inc. |
| * |
| * Authors: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> |
| * Oleksandr Grytsov <oleksandr_grytsov@epam.com> |
| * Oleksandr Dmytryshyn <oleksandr.dmytryshyn@globallogic.com> |
| * Iurii Konovalenko <iurii.konovalenko@globallogic.com> |
| */ |
| |
| #ifndef __XEN_PUBLIC_IO_SNDIF_H__ |
| #define __XEN_PUBLIC_IO_SNDIF_H__ |
| |
| #include "ring.h" |
| #include "../grant_table.h" |
| |
| /* |
| ****************************************************************************** |
| * Protocol version |
| ****************************************************************************** |
| */ |
| #define XENSND_PROTOCOL_VERSION 2 |
| |
| /* |
| ****************************************************************************** |
| * Feature and Parameter Negotiation |
| ****************************************************************************** |
| * |
| * Front->back notifications: when enqueuing a new request, sending a |
| * notification can be made conditional on xensnd_req (i.e., the generic |
| * hold-off mechanism provided by the ring macros). Backends must set |
| * xensnd_req appropriately (e.g., using RING_FINAL_CHECK_FOR_REQUESTS()). |
| * |
| * Back->front notifications: when enqueuing a new response, sending a |
| * notification can be made conditional on xensnd_resp (i.e., the generic |
| * hold-off mechanism provided by the ring macros). Frontends must set |
| * xensnd_resp appropriately (e.g., using RING_FINAL_CHECK_FOR_RESPONSES()). |
| * |
| * The two halves of a para-virtual sound card driver utilize nodes within |
| * XenStore to communicate capabilities and to negotiate operating parameters. |
| * This section enumerates these nodes which reside in the respective front and |
| * backend portions of XenStore, following the XenBus convention. |
| * |
| * All data in XenStore is stored as strings. Nodes specifying numeric |
| * values are encoded in decimal. Integer value ranges listed below are |
| * expressed as fixed sized integer types capable of storing the conversion |
| * of a properly formated node string, without loss of information. |
| * |
| ****************************************************************************** |
| * Example configuration |
| ****************************************************************************** |
| * |
| * Note: depending on the use-case backend can expose more sound cards and |
| * PCM devices/streams than the underlying HW physically has by employing |
| * SW mixers, configuring virtual sound streams, channels etc. |
| * |
| * This is an example of backend and frontend configuration: |
| * |
| *--------------------------------- Backend ----------------------------------- |
| * |
| * /local/domain/0/backend/vsnd/1/0/frontend-id = "1" |
| * /local/domain/0/backend/vsnd/1/0/frontend = "/local/domain/1/device/vsnd/0" |
| * /local/domain/0/backend/vsnd/1/0/state = "4" |
| * /local/domain/0/backend/vsnd/1/0/versions = "1,2" |
| * |
| *--------------------------------- Frontend ---------------------------------- |
| * |
| * /local/domain/1/device/vsnd/0/backend-id = "0" |
| * /local/domain/1/device/vsnd/0/backend = "/local/domain/0/backend/vsnd/1/0" |
| * /local/domain/1/device/vsnd/0/state = "4" |
| * /local/domain/1/device/vsnd/0/version = "1" |
| * |
| *----------------------------- Card configuration ---------------------------- |
| * |
| * /local/domain/1/device/vsnd/0/short-name = "Card short name" |
| * /local/domain/1/device/vsnd/0/long-name = "Card long name" |
| * /local/domain/1/device/vsnd/0/sample-rates = "8000,32000,44100,48000,96000" |
| * /local/domain/1/device/vsnd/0/sample-formats = "s8,u8,s16_le,s16_be" |
| * /local/domain/1/device/vsnd/0/buffer-size = "262144" |
| * |
| *------------------------------- PCM device 0 -------------------------------- |
| * |
| * /local/domain/1/device/vsnd/0/0/name = "General analog" |
| * /local/domain/1/device/vsnd/0/0/channels-max = "5" |
| * |
| *----------------------------- Stream 0, playback ---------------------------- |
| * |
| * /local/domain/1/device/vsnd/0/0/0/type = "p" |
| * /local/domain/1/device/vsnd/0/0/0/sample-formats = "s8,u8" |
| * /local/domain/1/device/vsnd/0/0/0/unique-id = "0" |
| * |
| * /local/domain/1/device/vsnd/0/0/0/ring-ref = "386" |
| * /local/domain/1/device/vsnd/0/0/0/event-channel = "15" |
| * /local/domain/1/device/vsnd/0/0/0/evt-ring-ref = "1386" |
| * /local/domain/1/device/vsnd/0/0/0/evt-event-channel = "215" |
| * |
| *------------------------------ Stream 1, capture ---------------------------- |
| * |
| * /local/domain/1/device/vsnd/0/0/1/type = "c" |
| * /local/domain/1/device/vsnd/0/0/1/channels-max = "2" |
| * /local/domain/1/device/vsnd/0/0/1/unique-id = "1" |
| * |
| * /local/domain/1/device/vsnd/0/0/1/ring-ref = "384" |
| * /local/domain/1/device/vsnd/0/0/1/event-channel = "13" |
| * /local/domain/1/device/vsnd/0/0/1/evt-ring-ref = "1384" |
| * /local/domain/1/device/vsnd/0/0/1/evt-event-channel = "213" |
| * |
| *------------------------------- PCM device 1 -------------------------------- |
| * |
| * /local/domain/1/device/vsnd/0/1/name = "HDMI-0" |
| * /local/domain/1/device/vsnd/0/1/sample-rates = "8000,32000,44100" |
| * |
| *------------------------------ Stream 0, capture ---------------------------- |
| * |
| * /local/domain/1/device/vsnd/0/1/0/type = "c" |
| * /local/domain/1/device/vsnd/0/1/0/unique-id = "2" |
| * |
| * /local/domain/1/device/vsnd/0/1/0/ring-ref = "387" |
| * /local/domain/1/device/vsnd/0/1/0/event-channel = "151" |
| * /local/domain/1/device/vsnd/0/1/0/evt-ring-ref = "1387" |
| * /local/domain/1/device/vsnd/0/1/0/evt-event-channel = "351" |
| * |
| *------------------------------- PCM device 2 -------------------------------- |
| * |
| * /local/domain/1/device/vsnd/0/2/name = "SPDIF" |
| * |
| *----------------------------- Stream 0, playback ---------------------------- |
| * |
| * /local/domain/1/device/vsnd/0/2/0/type = "p" |
| * /local/domain/1/device/vsnd/0/2/0/unique-id = "3" |
| * |
| * /local/domain/1/device/vsnd/0/2/0/ring-ref = "389" |
| * /local/domain/1/device/vsnd/0/2/0/event-channel = "152" |
| * /local/domain/1/device/vsnd/0/2/0/evt-ring-ref = "1389" |
| * /local/domain/1/device/vsnd/0/2/0/evt-event-channel = "452" |
| * |
| ****************************************************************************** |
| * Backend XenBus Nodes |
| ****************************************************************************** |
| * |
| *----------------------------- Protocol version ------------------------------ |
| * |
| * versions |
| * Values: <string> |
| * |
| * List of XENSND_LIST_SEPARATOR separated protocol versions supported |
| * by the backend. For example "1,2,3". |
| * |
| ****************************************************************************** |
| * Frontend XenBus Nodes |
| ****************************************************************************** |
| * |
| *-------------------------------- Addressing --------------------------------- |
| * |
| * dom-id |
| * Values: <uint16_t> |
| * |
| * Domain identifier. |
| * |
| * dev-id |
| * Values: <uint16_t> |
| * |
| * Device identifier. |
| * |
| * pcm-dev-idx |
| * Values: <uint8_t> |
| * |
| * Zero based contigous index of the PCM device. |
| * |
| * stream-idx |
| * Values: <uint8_t> |
| * |
| * Zero based contigous index of the stream of the PCM device. |
| * |
| * The following pattern is used for addressing: |
| * /local/domain/<dom-id>/device/vsnd/<dev-id>/<pcm-dev-idx>/<stream-idx>/... |
| * |
| *----------------------------- Protocol version ------------------------------ |
| * |
| * version |
| * Values: <string> |
| * |
| * Protocol version, chosen among the ones supported by the backend. |
| * |
| *------------------------------- PCM settings -------------------------------- |
| * |
| * Every virtualized sound frontend has a set of PCM devices and streams, each |
| * could be individually configured. Part of the PCM configuration can be |
| * defined at higher level of the hierarchy and be fully or partially re-used |
| * by the underlying layers. These configuration values are: |
| * o number of channels (min/max) |
| * o supported sample rates |
| * o supported sample formats. |
| * E.g. one can define these values for the whole card, device or stream. |
| * Every underlying layer in turn can re-define some or all of them to better |
| * fit its needs. For example, card may define number of channels to be |
| * in [1; 8] range, and some particular stream may be limited to [1; 2] only. |
| * The rule is that the underlying layer must be a subset of the upper layer |
| * range. |
| * |
| * channels-min |
| * Values: <uint8_t> |
| * |
| * The minimum amount of channels that is supported, [1; channels-max]. |
| * Optional, if not set or omitted a value of 1 is used. |
| * |
| * channels-max |
| * Values: <uint8_t> |
| * |
| * The maximum amount of channels that is supported. |
| * Must be at least <channels-min>. |
| * |
| * sample-rates |
| * Values: <list of uint32_t> |
| * |
| * List of supported sample rates separated by XENSND_LIST_SEPARATOR. |
| * Sample rates are expressed as a list of decimal values w/o any |
| * ordering requirement. |
| * |
| * sample-formats |
| * Values: <list of XENSND_PCM_FORMAT_XXX_STR> |
| * |
| * List of supported sample formats separated by XENSND_LIST_SEPARATOR. |
| * Items must not exceed XENSND_SAMPLE_FORMAT_MAX_LEN length. |
| * |
| * buffer-size |
| * Values: <uint32_t> |
| * |
| * The maximum size in octets of the buffer to allocate per stream. |
| * |
| *----------------------- Virtual sound card settings ------------------------- |
| * short-name |
| * Values: <char[32]> |
| * |
| * Short name of the virtual sound card. Optional. |
| * |
| * long-name |
| * Values: <char[80]> |
| * |
| * Long name of the virtual sound card. Optional. |
| * |
| *----------------------------- Device settings ------------------------------- |
| * name |
| * Values: <char[80]> |
| * |
| * Name of the sound device within the virtual sound card. Optional. |
| * |
| *----------------------------- Stream settings ------------------------------- |
| * |
| * type |
| * Values: "p", "c" |
| * |
| * Stream type: "p" - playback stream, "c" - capture stream |
| * |
| * If both capture and playback are needed then two streams need to be |
| * defined under the same device. |
| * |
| * unique-id |
| * Values: <uint32_t> |
| * |
| * After stream initialization it is assigned a unique ID (within the front |
| * driver), so every stream of the frontend can be identified by the |
| * backend by this ID. This is not equal to stream-idx as the later is |
| * zero based within the device, but this index is contigous within the |
| * driver. |
| * |
| *-------------------- Stream Request Transport Parameters -------------------- |
| * |
| * event-channel |
| * Values: <uint32_t> |
| * |
| * The identifier of the Xen event channel used to signal activity |
| * in the ring buffer. |
| * |
| * ring-ref |
| * Values: <uint32_t> |
| * |
| * The Xen grant reference granting permission for the backend to map |
| * a sole page in a single page sized ring buffer. |
| * |
| *--------------------- Stream Event Transport Parameters --------------------- |
| * |
| * This communication path is used to deliver asynchronous events from backend |
| * to frontend, set up per stream. |
| * |
| * evt-event-channel |
| * Values: <uint32_t> |
| * |
| * The identifier of the Xen event channel used to signal activity |
| * in the ring buffer. |
| * |
| * evt-ring-ref |
| * Values: <uint32_t> |
| * |
| * The Xen grant reference granting permission for the backend to map |
| * a sole page in a single page sized ring buffer. |
| * |
| ****************************************************************************** |
| * STATE DIAGRAMS |
| ****************************************************************************** |
| * |
| * Tool stack creates front and back state nodes with initial state |
| * XenbusStateInitialising. |
| * Tool stack creates and sets up frontend sound configuration nodes per domain. |
| * |
| * Front Back |
| * ================================= ===================================== |
| * XenbusStateInitialising XenbusStateInitialising |
| * o Query backend device identification |
| * data. |
| * o Open and validate backend device. |
| * | |
| * | |
| * V |
| * XenbusStateInitWait |
| * |
| * o Query frontend configuration |
| * o Allocate and initialize |
| * event channels per configured |
| * playback/capture stream. |
| * o Publish transport parameters |
| * that will be in effect during |
| * this connection. |
| * | |
| * | |
| * V |
| * XenbusStateInitialised |
| * |
| * o Query frontend transport parameters. |
| * o Connect to the event channels. |
| * | |
| * | |
| * V |
| * XenbusStateConnected |
| * |
| * o Create and initialize OS |
| * virtual sound device instances |
| * as per configuration. |
| * | |
| * | |
| * V |
| * XenbusStateConnected |
| * |
| * XenbusStateUnknown |
| * XenbusStateClosed |
| * XenbusStateClosing |
| * o Remove virtual sound device |
| * o Remove event channels |
| * | |
| * | |
| * V |
| * XenbusStateClosed |
| * |
| *------------------------------- Recovery flow ------------------------------- |
| * |
| * In case of frontend unrecoverable errors backend handles that as |
| * if frontend goes into the XenbusStateClosed state. |
| * |
| * In case of backend unrecoverable errors frontend tries removing |
| * the virtualized device. If this is possible at the moment of error, |
| * then frontend goes into the XenbusStateInitialising state and is ready for |
| * new connection with backend. If the virtualized device is still in use and |
| * cannot be removed, then frontend goes into the XenbusStateReconfiguring state |
| * until either the virtualized device removed or backend initiates a new |
| * connection. On the virtualized device removal frontend goes into the |
| * XenbusStateInitialising state. |
| * |
| * Note on XenbusStateReconfiguring state of the frontend: if backend has |
| * unrecoverable errors then frontend cannot send requests to the backend |
| * and thus cannot provide functionality of the virtualized device anymore. |
| * After backend is back to normal the virtualized device may still hold some |
| * state: configuration in use, allocated buffers, client application state etc. |
| * So, in most cases, this will require frontend to implement complex recovery |
| * reconnect logic. Instead, by going into XenbusStateReconfiguring state, |
| * frontend will make sure no new clients of the virtualized device are |
| * accepted, allow existing client(s) to exit gracefully by signaling error |
| * state etc. |
| * Once all the clients are gone frontend can reinitialize the virtualized |
| * device and get into XenbusStateInitialising state again signaling the |
| * backend that a new connection can be made. |
| * |
| * There are multiple conditions possible under which frontend will go from |
| * XenbusStateReconfiguring into XenbusStateInitialising, some of them are OS |
| * specific. For example: |
| * 1. The underlying OS framework may provide callbacks to signal that the last |
| * client of the virtualized device has gone and the device can be removed |
| * 2. Frontend can schedule a deferred work (timer/tasklet/workqueue) |
| * to periodically check if this is the right time to re-try removal of |
| * the virtualized device. |
| * 3. By any other means. |
| * |
| ****************************************************************************** |
| * PCM FORMATS |
| ****************************************************************************** |
| * |
| * XENSND_PCM_FORMAT_<format>[_<endian>] |
| * |
| * format: <S/U/F><bits> or <name> |
| * S - signed, U - unsigned, F - float |
| * bits - 8, 16, 24, 32 |
| * name - MU_LAW, GSM, etc. |
| * |
| * endian: <LE/BE>, may be absent |
| * LE - Little endian, BE - Big endian |
| */ |
| #define XENSND_PCM_FORMAT_S8 0 |
| #define XENSND_PCM_FORMAT_U8 1 |
| #define XENSND_PCM_FORMAT_S16_LE 2 |
| #define XENSND_PCM_FORMAT_S16_BE 3 |
| #define XENSND_PCM_FORMAT_U16_LE 4 |
| #define XENSND_PCM_FORMAT_U16_BE 5 |
| #define XENSND_PCM_FORMAT_S24_LE 6 |
| #define XENSND_PCM_FORMAT_S24_BE 7 |
| #define XENSND_PCM_FORMAT_U24_LE 8 |
| #define XENSND_PCM_FORMAT_U24_BE 9 |
| #define XENSND_PCM_FORMAT_S32_LE 10 |
| #define XENSND_PCM_FORMAT_S32_BE 11 |
| #define XENSND_PCM_FORMAT_U32_LE 12 |
| #define XENSND_PCM_FORMAT_U32_BE 13 |
| #define XENSND_PCM_FORMAT_F32_LE 14 /* 4-byte float, IEEE-754 32-bit, */ |
| #define XENSND_PCM_FORMAT_F32_BE 15 /* range -1.0 to 1.0 */ |
| #define XENSND_PCM_FORMAT_F64_LE 16 /* 8-byte float, IEEE-754 64-bit, */ |
| #define XENSND_PCM_FORMAT_F64_BE 17 /* range -1.0 to 1.0 */ |
| #define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE 18 |
| #define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE 19 |
| #define XENSND_PCM_FORMAT_MU_LAW 20 |
| #define XENSND_PCM_FORMAT_A_LAW 21 |
| #define XENSND_PCM_FORMAT_IMA_ADPCM 22 |
| #define XENSND_PCM_FORMAT_MPEG 23 |
| #define XENSND_PCM_FORMAT_GSM 24 |
| |
| /* |
| ****************************************************************************** |
| * REQUEST CODES |
| ****************************************************************************** |
| */ |
| #define XENSND_OP_OPEN 0 |
| #define XENSND_OP_CLOSE 1 |
| #define XENSND_OP_READ 2 |
| #define XENSND_OP_WRITE 3 |
| #define XENSND_OP_SET_VOLUME 4 |
| #define XENSND_OP_GET_VOLUME 5 |
| #define XENSND_OP_MUTE 6 |
| #define XENSND_OP_UNMUTE 7 |
| #define XENSND_OP_TRIGGER 8 |
| #define XENSND_OP_HW_PARAM_QUERY 9 |
| |
| #define XENSND_OP_TRIGGER_START 0 |
| #define XENSND_OP_TRIGGER_PAUSE 1 |
| #define XENSND_OP_TRIGGER_STOP 2 |
| #define XENSND_OP_TRIGGER_RESUME 3 |
| |
| /* |
| ****************************************************************************** |
| * EVENT CODES |
| ****************************************************************************** |
| */ |
| #define XENSND_EVT_CUR_POS 0 |
| |
| /* |
| ****************************************************************************** |
| * XENSTORE FIELD AND PATH NAME STRINGS, HELPERS |
| ****************************************************************************** |
| */ |
| #define XENSND_DRIVER_NAME "vsnd" |
| |
| #define XENSND_LIST_SEPARATOR "," |
| /* Field names */ |
| #define XENSND_FIELD_BE_VERSIONS "versions" |
| #define XENSND_FIELD_FE_VERSION "version" |
| #define XENSND_FIELD_VCARD_SHORT_NAME "short-name" |
| #define XENSND_FIELD_VCARD_LONG_NAME "long-name" |
| #define XENSND_FIELD_RING_REF "ring-ref" |
| #define XENSND_FIELD_EVT_CHNL "event-channel" |
| #define XENSND_FIELD_EVT_RING_REF "evt-ring-ref" |
| #define XENSND_FIELD_EVT_EVT_CHNL "evt-event-channel" |
| #define XENSND_FIELD_DEVICE_NAME "name" |
| #define XENSND_FIELD_TYPE "type" |
| #define XENSND_FIELD_STREAM_UNIQUE_ID "unique-id" |
| #define XENSND_FIELD_CHANNELS_MIN "channels-min" |
| #define XENSND_FIELD_CHANNELS_MAX "channels-max" |
| #define XENSND_FIELD_SAMPLE_RATES "sample-rates" |
| #define XENSND_FIELD_SAMPLE_FORMATS "sample-formats" |
| #define XENSND_FIELD_BUFFER_SIZE "buffer-size" |
| |
| /* Stream type field values. */ |
| #define XENSND_STREAM_TYPE_PLAYBACK "p" |
| #define XENSND_STREAM_TYPE_CAPTURE "c" |
| /* Sample rate max string length */ |
| #define XENSND_SAMPLE_RATE_MAX_LEN 11 |
| /* Sample format field values */ |
| #define XENSND_SAMPLE_FORMAT_MAX_LEN 24 |
| |
| #define XENSND_PCM_FORMAT_S8_STR "s8" |
| #define XENSND_PCM_FORMAT_U8_STR "u8" |
| #define XENSND_PCM_FORMAT_S16_LE_STR "s16_le" |
| #define XENSND_PCM_FORMAT_S16_BE_STR "s16_be" |
| #define XENSND_PCM_FORMAT_U16_LE_STR "u16_le" |
| #define XENSND_PCM_FORMAT_U16_BE_STR "u16_be" |
| #define XENSND_PCM_FORMAT_S24_LE_STR "s24_le" |
| #define XENSND_PCM_FORMAT_S24_BE_STR "s24_be" |
| #define XENSND_PCM_FORMAT_U24_LE_STR "u24_le" |
| #define XENSND_PCM_FORMAT_U24_BE_STR "u24_be" |
| #define XENSND_PCM_FORMAT_S32_LE_STR "s32_le" |
| #define XENSND_PCM_FORMAT_S32_BE_STR "s32_be" |
| #define XENSND_PCM_FORMAT_U32_LE_STR "u32_le" |
| #define XENSND_PCM_FORMAT_U32_BE_STR "u32_be" |
| #define XENSND_PCM_FORMAT_F32_LE_STR "float_le" |
| #define XENSND_PCM_FORMAT_F32_BE_STR "float_be" |
| #define XENSND_PCM_FORMAT_F64_LE_STR "float64_le" |
| #define XENSND_PCM_FORMAT_F64_BE_STR "float64_be" |
| #define XENSND_PCM_FORMAT_IEC958_SUBFRAME_LE_STR "iec958_subframe_le" |
| #define XENSND_PCM_FORMAT_IEC958_SUBFRAME_BE_STR "iec958_subframe_be" |
| #define XENSND_PCM_FORMAT_MU_LAW_STR "mu_law" |
| #define XENSND_PCM_FORMAT_A_LAW_STR "a_law" |
| #define XENSND_PCM_FORMAT_IMA_ADPCM_STR "ima_adpcm" |
| #define XENSND_PCM_FORMAT_MPEG_STR "mpeg" |
| #define XENSND_PCM_FORMAT_GSM_STR "gsm" |
| |
| |
| /* |
| ****************************************************************************** |
| * STATUS RETURN CODES |
| ****************************************************************************** |
| * |
| * Status return code is zero on success and -XEN_EXX on failure. |
| * |
| ****************************************************************************** |
| * Assumptions |
| ****************************************************************************** |
| * o usage of grant reference 0 as invalid grant reference: |
| * grant reference 0 is valid, but never exposed to a PV driver, |
| * because of the fact it is already in use/reserved by the PV console. |
| * o all references in this document to page sizes must be treated |
| * as pages of size XEN_PAGE_SIZE unless otherwise noted. |
| * |
| ****************************************************************************** |
| * Description of the protocol between frontend and backend driver |
| ****************************************************************************** |
| * |
| * The two halves of a Para-virtual sound driver communicate with |
| * each other using shared pages and event channels. |
| * Shared page contains a ring with request/response packets. |
| * |
| * Packets, used for input/output operations, e.g. read/write, set/get volume, |
| * etc., provide offset/length fields in order to allow asynchronous protocol |
| * operation with buffer space sharing: part of the buffer allocated at |
| * XENSND_OP_OPEN can be used for audio samples and part, for example, |
| * for volume control. |
| * |
| * All reserved fields in the structures below must be 0. |
| * |
| *---------------------------------- Requests --------------------------------- |
| * |
| * All request packets have the same length (64 octets) |
| * All request packets have common header: |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | operation | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * id - uint16_t, private guest value, echoed in response |
| * operation - uint8_t, operation code, XENSND_OP_??? |
| * |
| * For all packets which use offset and length: |
| * offset - uint32_t, read or write data offset within the shared buffer, |
| * passed with XENSND_OP_OPEN request, octets, |
| * [0; XENSND_OP_OPEN.buffer_sz - 1]. |
| * length - uint32_t, read or write data length, octets |
| * |
| * Request open - open a PCM stream for playback or capture: |
| * |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | XENSND_OP_OPEN | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * | pcm_rate | 12 |
| * +----------------+----------------+----------------+----------------+ |
| * | pcm_format | pcm_channels | reserved | 16 |
| * +----------------+----------------+----------------+----------------+ |
| * | buffer_sz | 20 |
| * +----------------+----------------+----------------+----------------+ |
| * | gref_directory | 24 |
| * +----------------+----------------+----------------+----------------+ |
| * | period_sz | 28 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 32 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 64 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * pcm_rate - uint32_t, stream data rate, Hz |
| * pcm_format - uint8_t, XENSND_PCM_FORMAT_XXX value |
| * pcm_channels - uint8_t, number of channels of this stream, |
| * [channels-min; channels-max] |
| * buffer_sz - uint32_t, buffer size to be allocated, octets |
| * period_sz - uint32_t, event period size, octets |
| * This is the requested value of the period at which frontend would |
| * like to receive XENSND_EVT_CUR_POS notifications from the backend when |
| * stream position advances during playback/capture. |
| * It shows how many octets are expected to be played/captured before |
| * sending such an event. |
| * If set to 0 no XENSND_EVT_CUR_POS events are sent by the backend. |
| * |
| * gref_directory - grant_ref_t, a reference to the first shared page |
| * describing shared buffer references. At least one page exists. If shared |
| * buffer size (buffer_sz) exceeds what can be addressed by this single page, |
| * then reference to the next page must be supplied (see gref_dir_next_page |
| * below) |
| */ |
| |
| struct xensnd_open_req { |
| uint32_t pcm_rate; |
| uint8_t pcm_format; |
| uint8_t pcm_channels; |
| uint16_t reserved; |
| uint32_t buffer_sz; |
| grant_ref_t gref_directory; |
| uint32_t period_sz; |
| }; |
| |
| /* |
| * Shared page for XENSND_OP_OPEN buffer descriptor (gref_directory in the |
| * request) employs a list of pages, describing all pages of the shared data |
| * buffer: |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | gref_dir_next_page | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | gref[0] | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | gref[i] | i*4+8 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | gref[N - 1] | N*4+8 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * gref_dir_next_page - grant_ref_t, reference to the next page describing |
| * page directory. Must be 0 if there are no more pages in the list. |
| * gref[i] - grant_ref_t, reference to a shared page of the buffer |
| * allocated at XENSND_OP_OPEN |
| * |
| * Number of grant_ref_t entries in the whole page directory is not |
| * passed, but instead can be calculated as: |
| * num_grefs_total = (XENSND_OP_OPEN.buffer_sz + XEN_PAGE_SIZE - 1) / |
| * XEN_PAGE_SIZE |
| */ |
| |
| struct xensnd_page_directory { |
| grant_ref_t gref_dir_next_page; |
| grant_ref_t gref[1]; /* Variable length */ |
| }; |
| |
| /* |
| * Request close - close an opened pcm stream: |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | XENSND_OP_CLOSE| reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 64 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * Request read/write - used for read (for capture) or write (for playback): |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | operation | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * | offset | 12 |
| * +----------------+----------------+----------------+----------------+ |
| * | length | 16 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 20 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 64 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * operation - XENSND_OP_READ for read or XENSND_OP_WRITE for write |
| */ |
| |
| struct xensnd_rw_req { |
| uint32_t offset; |
| uint32_t length; |
| }; |
| |
| /* |
| * Request set/get volume - set/get channels' volume of the stream given: |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | operation | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * | offset | 12 |
| * +----------------+----------------+----------------+----------------+ |
| * | length | 16 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 20 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 64 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * operation - XENSND_OP_SET_VOLUME for volume set |
| * or XENSND_OP_GET_VOLUME for volume get |
| * Buffer passed with XENSND_OP_OPEN is used to exchange volume |
| * values: |
| * |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | channel[0] | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | channel[i] | i*4 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | channel[N - 1] | (N-1)*4 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * N = XENSND_OP_OPEN.pcm_channels |
| * i - uint8_t, index of a channel |
| * channel[i] - sint32_t, volume of i-th channel |
| * Volume is expressed as a signed value in steps of 0.001 dB, |
| * while 0 being 0 dB. |
| * |
| * Request mute/unmute - mute/unmute stream: |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | operation | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * | offset | 12 |
| * +----------------+----------------+----------------+----------------+ |
| * | length | 16 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 20 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 64 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * operation - XENSND_OP_MUTE for mute or XENSND_OP_UNMUTE for unmute |
| * Buffer passed with XENSND_OP_OPEN is used to exchange mute/unmute |
| * values: |
| * |
| * 0 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | channel[0] | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | channel[i] | i*4 |
| * +----------------+----------------+----------------+----------------+ |
| * +/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | channel[N - 1] | (N-1)*4 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * N = XENSND_OP_OPEN.pcm_channels |
| * i - uint8_t, index of a channel |
| * channel[i] - uint8_t, non-zero if i-th channel needs to be muted/unmuted |
| * |
| *------------------------------------ N.B. ----------------------------------- |
| * |
| * The 'struct xensnd_rw_req' is also used for XENSND_OP_SET_VOLUME, |
| * XENSND_OP_GET_VOLUME, XENSND_OP_MUTE, XENSND_OP_UNMUTE. |
| * |
| * Request stream running state change - trigger PCM stream running state |
| * to start, stop, pause or resume: |
| * |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | _OP_TRIGGER | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * | type | reserved | 12 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 16 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 64 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * type - uint8_t, XENSND_OP_TRIGGER_XXX value |
| */ |
| |
| struct xensnd_trigger_req { |
| uint8_t type; |
| }; |
| |
| /* |
| * Request stream parameter ranges: request intervals and |
| * masks of supported ranges for stream configuration values. |
| * |
| * Sound device configuration for a particular stream is a limited subset |
| * of the multidimensional configuration available on XenStore, e.g. |
| * once the frame rate has been selected there is a limited supported range |
| * for sample rates becomes available (which might be the same set configured |
| * on XenStore or less). For example, selecting 96kHz sample rate may limit |
| * number of channels available for such configuration from 4 to 2, etc. |
| * Thus, each call to XENSND_OP_HW_PARAM_QUERY may reduce configuration |
| * space making it possible to iteratively get the final stream configuration, |
| * used in XENSND_OP_OPEN request. |
| * |
| * See response format for this request. |
| * |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | _HW_PARAM_QUERY| reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * | formats mask low 32-bit | 12 |
| * +----------------+----------------+----------------+----------------+ |
| * | formats mask high 32-bit | 16 |
| * +----------------+----------------+----------------+----------------+ |
| * | min rate | 20 |
| * +----------------+----------------+----------------+----------------+ |
| * | max rate | 24 |
| * +----------------+----------------+----------------+----------------+ |
| * | min channels | 28 |
| * +----------------+----------------+----------------+----------------+ |
| * | max channels | 32 |
| * +----------------+----------------+----------------+----------------+ |
| * | min buffer frames | 36 |
| * +----------------+----------------+----------------+----------------+ |
| * | max buffer frames | 40 |
| * +----------------+----------------+----------------+----------------+ |
| * | min period frames | 44 |
| * +----------------+----------------+----------------+----------------+ |
| * | max period frames | 48 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 52 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 64 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * formats - uint64_t, bit mask representing values of the parameter |
| * made as bitwise OR of (1 << XENSND_PCM_FORMAT_XXX) values |
| * |
| * For interval parameters: |
| * min - uint32_t, minimum value of the parameter |
| * max - uint32_t, maximum value of the parameter |
| * |
| * Frame is defined as a product of the number of channels by the |
| * number of octets per one sample. |
| */ |
| |
| struct xensnd_query_hw_param { |
| uint64_t formats; |
| struct { |
| uint32_t min; |
| uint32_t max; |
| } rates; |
| struct { |
| uint32_t min; |
| uint32_t max; |
| } channels; |
| struct { |
| uint32_t min; |
| uint32_t max; |
| } buffer; |
| struct { |
| uint32_t min; |
| uint32_t max; |
| } period; |
| }; |
| |
| /* |
| *---------------------------------- Responses -------------------------------- |
| * |
| * All response packets have the same length (64 octets) |
| * |
| * All response packets have common header: |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | operation | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | status | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * id - uint16_t, copied from the request |
| * operation - uint8_t, XENSND_OP_* - copied from request |
| * status - int32_t, response status, zero on success and -XEN_EXX on failure |
| * |
| * |
| * HW parameter query response - response for XENSND_OP_HW_PARAM_QUERY: |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | operation | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | status | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * | formats mask low 32-bit | 12 |
| * +----------------+----------------+----------------+----------------+ |
| * | formats mask high 32-bit | 16 |
| * +----------------+----------------+----------------+----------------+ |
| * | min rate | 20 |
| * +----------------+----------------+----------------+----------------+ |
| * | max rate | 24 |
| * +----------------+----------------+----------------+----------------+ |
| * | min channels | 28 |
| * +----------------+----------------+----------------+----------------+ |
| * | max channels | 32 |
| * +----------------+----------------+----------------+----------------+ |
| * | min buffer frames | 36 |
| * +----------------+----------------+----------------+----------------+ |
| * | max buffer frames | 40 |
| * +----------------+----------------+----------------+----------------+ |
| * | min period frames | 44 |
| * +----------------+----------------+----------------+----------------+ |
| * | max period frames | 48 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 52 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 64 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * Meaning of the values in this response is the same as for |
| * XENSND_OP_HW_PARAM_QUERY request. |
| */ |
| |
| /* |
| *----------------------------------- Events ---------------------------------- |
| * |
| * Events are sent via shared page allocated by the front and propagated by |
| * evt-event-channel/evt-ring-ref XenStore entries |
| * All event packets have the same length (64 octets) |
| * All event packets have common header: |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | type | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * id - uint16_t, event id, may be used by front |
| * type - uint8_t, type of the event |
| * |
| * |
| * Current stream position - event from back to front when stream's |
| * playback/capture position has advanced: |
| * 0 1 2 3 octet |
| * +----------------+----------------+----------------+----------------+ |
| * | id | _EVT_CUR_POS | reserved | 4 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 8 |
| * +----------------+----------------+----------------+----------------+ |
| * | position low 32-bit | 12 |
| * +----------------+----------------+----------------+----------------+ |
| * | position high 32-bit | 16 |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 20 |
| * +----------------+----------------+----------------+----------------+ |
| * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/| |
| * +----------------+----------------+----------------+----------------+ |
| * | reserved | 64 |
| * +----------------+----------------+----------------+----------------+ |
| * |
| * position - current value of stream's playback/capture position, octets |
| * |
| */ |
| |
| struct xensnd_cur_pos_evt { |
| uint64_t position; |
| }; |
| |
| struct xensnd_req { |
| uint16_t id; |
| uint8_t operation; |
| uint8_t reserved[5]; |
| union { |
| struct xensnd_open_req open; |
| struct xensnd_rw_req rw; |
| struct xensnd_trigger_req trigger; |
| struct xensnd_query_hw_param hw_param; |
| uint8_t reserved[56]; |
| } op; |
| }; |
| |
| struct xensnd_resp { |
| uint16_t id; |
| uint8_t operation; |
| uint8_t reserved; |
| int32_t status; |
| union { |
| struct xensnd_query_hw_param hw_param; |
| uint8_t reserved1[56]; |
| } resp; |
| }; |
| |
| struct xensnd_evt { |
| uint16_t id; |
| uint8_t type; |
| uint8_t reserved[5]; |
| union { |
| struct xensnd_cur_pos_evt cur_pos; |
| uint8_t reserved[56]; |
| } op; |
| }; |
| |
| DEFINE_RING_TYPES(xen_sndif, struct xensnd_req, struct xensnd_resp); |
| |
| /* |
| ****************************************************************************** |
| * Back to front events delivery |
| ****************************************************************************** |
| * In order to deliver asynchronous events from back to front a shared page is |
| * allocated by front and its granted reference propagated to back via |
| * XenStore entries (evt-ring-ref/evt-event-channel). |
| * This page has a common header used by both front and back to synchronize |
| * access and control event's ring buffer, while back being a producer of the |
| * events and front being a consumer. The rest of the page after the header |
| * is used for event packets. |
| * |
| * Upon reception of an event(s) front may confirm its reception |
| * for either each event, group of events or none. |
| */ |
| |
| struct xensnd_event_page { |
| uint32_t in_cons; |
| uint32_t in_prod; |
| uint8_t reserved[56]; |
| }; |
| |
| #define XENSND_EVENT_PAGE_SIZE XEN_PAGE_SIZE |
| #define XENSND_IN_RING_OFFS (sizeof(struct xensnd_event_page)) |
| #define XENSND_IN_RING_SIZE (XENSND_EVENT_PAGE_SIZE - XENSND_IN_RING_OFFS) |
| #define XENSND_IN_RING_LEN (XENSND_IN_RING_SIZE / sizeof(struct xensnd_evt)) |
| #define XENSND_IN_RING(page) \ |
| ((struct xensnd_evt *)((char *)(page) + XENSND_IN_RING_OFFS)) |
| #define XENSND_IN_RING_REF(page, idx) \ |
| (XENSND_IN_RING((page))[(idx) % XENSND_IN_RING_LEN]) |
| |
| #endif /* __XEN_PUBLIC_IO_SNDIF_H__ */ |
