sdk/fidl/fuchsia.hardware.audio/stream_config.fidl

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.hardware.audio;

using fuchsia.hardware.audio.signalprocessing;

/// Gain state requested by the client or returned by the driver.
type GainState = table {
    /// Current mute state. If not included, the state is unmuted.
    ///
    /// Optional.
    1: muted bool;

    /// Current Automatic Gain Control (AGC) state. If not included, AGC is disabled.
    ///
    /// Optional.
    2: agc_enabled bool;

    /// Current gain in decibels.
    ///
    /// Required.
    3: gain_db float32;
};

type StreamProperties = table {
    /// A unique identifier. If not included, there is no unique id for the StreamConfig.
    /// `unique_id` arrays starting with 0x42, 0x54, ... (or `BT` in ASCII) are
    /// reserved for drivers implementing Bluetooth technologies.
    /// `unique_id` arrays starting with 0x55, 0x53, 0x42, ... (or `USB` in ASCII) are
    /// reserved for drivers implementing USB technologies.
    /// Note that even though the above values map to readable ASCII characters, array
    /// values can span the entire uint8 range (0-255).
    ///
    /// Optional.
    1: unique_id array<uint8, UNIQUE_ID_SIZE>;

    /// Driver type is input (true) or output (false)
    ///
    /// Required.
    2: is_input bool;

    /// Gain mute capability. If not included, the StreamConfig can't mute.
    ///
    /// Optional.
    3: can_mute bool;

    /// Automatic Gain Control (AGC) capability. If not included, the StreamConfig can't AGC.
    ///
    /// Optional.
    4: can_agc bool;

    /// Minimum gain in decibels.
    ///
    /// Required.
    5: min_gain_db float32;

    /// Maximum gain in decibels.
    ///
    /// Required.
    6: max_gain_db float32;

    /// Gain step in decibels, this value must not be negative, but may be zero to convey an
    /// effectively continuous range of values. Must not exceed `max_gain_db` - `min_gain_db`.
    ///
    /// Required.
    7: gain_step_db float32;

    /// Plug Detect Capabilities.
    ///
    /// Required.
    8: plug_detect_capabilities PlugDetectCapabilities;

    /// UI string for the manufacturer name. If not included, the manufacturer is unspecified.
    ///
    /// Optional.
    9: manufacturer string:MAX_UI_STRING_SIZE;

    /// UI string for the product name. If not included, the product name is unspecified.
    ///
    /// Optional.
    10: product string:MAX_UI_STRING_SIZE;

    /// An identifier for the clock domain in which this hardware operates. If
    /// two hardware devices have the same clock domain, their clock rates are
    /// identical and perfectly synchronized. Although these two clocks have the
    /// same rate, the clock positions may be offset from each other by an
    /// arbitrary (but fixed) amount. The clock_domain typically comes from a
    /// system wide entity, such as a platform bus or global clock tree.
    ///
    /// There are two special values:
    ///
    /// *  `CLOCK_DOMAIN_MONOTONIC` means the hardware is operating at the same
    ///    rate as the system montonic clock.
    ///
    /// *  `CLOCK_DOMAIN_EXTERNAL` means the hardware is operating at an unknown
    ///    rate and is not synchronized with any known clock, not even with
    ///    other clocks in domain `CLOCK_DOMAIN_EXTERNAL`.
    ///
    /// If the domain is not `CLOCK_DOMAIN_MONOTONIC`, client must use position
    /// notification updates to recover the hardware's clock.
    ///
    /// Required.
    11: clock_domain ClockDomain;
};

/// For an overview see
/// [Audio Driver Streaming Interface](https://fuchsia.dev/fuchsia-src/concepts/drivers/driver_architectures/audio_drivers/audio_streaming)
/// # Deprecation
///
/// Not supported anymore, instead use an
/// [Audio Composite](https://fuchsia.dev/fuchsia-src/development/audio/drivers/composite)
/// with one Ring Buffer, see
/// [Audio Drivers Architecture](https://fuchsia.dev/fuchsia-src/development/audio/drivers/architecture)
@available(deprecated=20)
closed protocol StreamConfig {
    /// Allows providing driver health state.
    compose Health;

    /// Allows providing signal processing capabilities.
    compose fuchsia.hardware.audio.signalprocessing.Connector;

    /// Retrieves top level static properties.
    strict GetProperties() -> (struct {
        properties StreamProperties;
    });

    /// Gets formats supported by a given driver. When not all combinations supported by the
    /// driver can be described with one `SupportedFormats`, the driver returns more than one
    /// `SupportedFormats` in the returned vector. For example, if one `SupportedFormats` allows
    /// for 32 bits samples at 48KHz, and 16 bits samples at 96KHz, but not 32 bits samples at
    /// 96KHz, then the driver replies with 2 `SupportedFormats`: <<32bits>,<48KHz>> and
    /// <<16bits>,<96KHz>>. For simplicity, this example ignores parameters other than rate and
    /// bits per sample. In the case where the driver supports either 16 or 32 bits samples at
    /// either 48 or 96KHz, the driver would reply with 1 `SupportedFormats`:
    /// <<16bits,32bits>,<48KHz,96KHz>>.
    strict GetSupportedFormats() -> (struct {
        supported_formats vector<SupportedFormats>:MAX_COUNT_FORMATS;
    });

    /// `CreateRingBuffer` is sent by clients to select a stream format based on information that
    /// the driver provides in `GetSupportedFormats` what is supported by the client, and any other
    /// requirement. The `ring_buffer` channel is used to control the audio buffer, if a previous
    /// ring buffer channel had been established and was still active, the driver must close that
    /// (ring buffer) channel and make every attempt to gracefully quiesce any on-going streaming
    /// operations in the process.
    strict CreateRingBuffer(resource struct {
        format Format;
        ring_buffer server_end:RingBuffer;
    });

    /// Get the gain state via a hanging get. The driver will reply to the first `WatchGainState`
    /// sent by the client and this reply must include a `gain_db` set to 0dB or lower. The driver
    /// will not respond to subsequent client `WatchGainState` calls until the gain state changes
    /// from what was most recently reported.
    /// If `WatchGainState` is called for a second time before the first call has completed, then
    /// the protocol channel must be closed with the error `ZX_ERR_BAD_STATE`.
    strict WatchGainState() -> (struct {
        gain_state GainState;
    });

    /// Client update of the gain state.
    strict SetGain(struct {
        target_state GainState;
    });

    /// Get the plug detect state via a hanging get. The driver will reply to the first
    /// `WatchPlugState` sent by the client. The driver will not respond to subsequent client
    /// `WatchPlugState` calls until the plug state changes from what was most recently reported.
    /// If `WatchPlugState` is called for a second time before the first call has completed, then
    /// the protocol channel must be closed with the error `ZX_ERR_BAD_STATE`.
    strict WatchPlugState() -> (struct {
        plug_state PlugState;
    });
};

/// # Deprecation
///
/// Not supported anymore, instead use an
/// [Audio Composite](https://fuchsia.dev/fuchsia-src/development/audio/drivers/composite)
/// with one Ring Buffer, see
/// [Audio Drivers Architecture](https://fuchsia.dev/fuchsia-src/development/audio/drivers/architecture)
@available(deprecated=20)
service StreamConfigService {
    stream_config client_end:StreamConfig;
};