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linux/include/xen/interface/io/sndif.h
Oleksandr Andrushchenko 2843531fb6 xen/sndif: add sound-device ABI 
Add ABI for the two halves of a para-virtualized
sound driver to communicate with each other.

The ABI allows implementing audio playback and capture as
well as volume control and possibility to mute/unmute
audio sources.

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. Thus, allowing fine tunned configurations per
frontend.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Oleksandr Grytsov <oleksandr_grytsov@epam.com>
Signed-off-by: Oleksandr Dmytryshyn <oleksandr.dmytryshyn@globallogic.com>
Signed-off-by: Iurii Konovalenko <iurii.konovalenko@globallogic.com>
Acked-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
2017-05-02 11:13:03 +02:00

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/******************************************************************************
* 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"
/*
******************************************************************************
* 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"
*
*------------------------------ 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"
*
*------------------------------- 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"
*
*------------------------------- 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"
*
******************************************************************************
* 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.
*
******************************************************************************
* 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
/*
******************************************************************************
* 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_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 (32 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
* +----------------+----------------+----------------+----------------+
* | reserved | 28
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 32
* +----------------+----------------+----------------+----------------+
*
* 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
* 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;
};
/*
* 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 | 32
* +----------------+----------------+----------------+----------------+
*
* 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 | 32
* +----------------+----------------+----------------+----------------+
*
* 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 | 32
* +----------------+----------------+----------------+----------------+
*
* 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 | 32
* +----------------+----------------+----------------+----------------+
*
* 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.
*/
/*
*---------------------------------- Responses --------------------------------
*
* All response packets have the same length (32 octets)
*
* Response for all requests:
* 0 1 2 3 octet
* +----------------+----------------+----------------+----------------+
* | id | operation | reserved | 4
* +----------------+----------------+----------------+----------------+
* | status | 8
* +----------------+----------------+----------------+----------------+
* | reserved | 12
* +----------------+----------------+----------------+----------------+
* |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
* +----------------+----------------+----------------+----------------+
* | reserved | 32
* +----------------+----------------+----------------+----------------+
*
* 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
*/
struct xensnd_req {
uint16_t id;
uint8_t operation;
uint8_t reserved[5];
union {
struct xensnd_open_req open;
struct xensnd_rw_req rw;
uint8_t reserved[24];
} op;
};
struct xensnd_resp {
uint16_t id;
uint8_t operation;
uint8_t reserved;
int32_t status;
uint8_t reserved1[24];
};
DEFINE_RING_TYPES(xen_sndif, struct xensnd_req, struct xensnd_resp);
#endif /* __XEN_PUBLIC_IO_SNDIF_H__ */
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