sdk/fidl/fuchsia.hardware.audio/dai.fidl

// Copyright 2020 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 zx;

const uint32 MAX_DAI_UI_STRING_SIZE = 256;
const uint32 MAX_COUNT_DAI_FORMATS = 64;

struct DaiInfo {
    /// Name of the DAI interface provider manufacturer.
    string:MAX_DAI_UI_STRING_SIZE manufacturer;
    /// Product name of the DAI interface provider.
    string:MAX_DAI_UI_STRING_SIZE product_name;
};

/// For an overview see
/// [Digital Audio Interface](//docs/concepts/drivers/driver_interfaces/audio_dai.md)
protocol Dai {

    /// Resets the DAI HW. The `ring_buffer` channel obtained via `CreateRingBuffer` may be closed
    /// by the driver, in this case the client needs to obtain a new `ring_buffer`.
    /// `Reset` returns when the reset is completed. If the driver can't successfully reset the HW,
    /// it will close the DAI protocol channel, in this case the client may obtain a new DAI
    /// protocol channel and retry.
    Reset() -> ();

    /// Retrieves textual information about the DAI.
    GetInfo() -> (DaiInfo info);

    /// Retrieves the DAI formats supported by the DAI, if not available at the time the DAI
    /// may reply with an error status and the client may retry at a later time.
    /// Retrieving multiple `DaiSupportedFormats` allows for cases where exclusive combinations of
    /// the parameters in SupportedFormats may be supported.
    GetDaiFormats() -> (vector<DaiSupportedFormats>:MAX_COUNT_DAI_FORMATS dai_formats)
        error zx.status;

    /// Retrieves the ring buffer formats supported by the DAI, if not available at the time the DAI
    /// may reply with an error status and the client may retry at a later time.
    /// Retrieving multiple `SupportedFormats` allows for cases where exclusive combinations of
    /// the parameters in `SupportedFormats` may be supported.
    GetRingBufferFormats() -> (vector<SupportedFormats>:MAX_COUNT_FORMATS ring_buffer_formats)
        error zx.status;

    /// `CreateRingBuffer` is sent by clients to select both a DAI format and a ring buffer format
    /// based on information that the driver provides in `GetDaiFormats` and `GetRingBufferFormats`,
    /// 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.
    CreateRingBuffer(DaiFormat dai_format, Format ring_buffer_format,
                     request<RingBuffer> ring_buffer);
};