audio/4.0/IDevicesFactory.hal

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.hardware.audio@4.0;

import android.hardware.audio.common@4.0;
import IDevice;
import IPrimaryDevice;

/** This factory allows a HAL implementation to be split in multiple independent
 *  devices (called module in the pre-treble API).
 *  Note that this division is arbitrary and implementation are free
 *  to only have a Primary.
 *  The framework will query the devices according to audio_policy_configuration.xml
 *
 *  Each device name is arbitrary, provided by the vendor's audio_policy_configuration.xml
 *  and only used to identify a device in this factory.
 *  The framework must not interpret the name, treating it as a vendor opaque data
 *  with the following exception:
 *  - the "r_submix" device that must be present to support policyMixes (Eg: Android projected).
 *    Note that this Device is included by default in a build derived from AOSP.
 *
 *  Note that on AOSP Oreo (including MR1) the "a2dp" module is not using this API
 *  but is loaded directly from the system partition using the legacy API
 *  due to limitations with the Bluetooth framework.
 */
interface IDevicesFactory {

    /**
     * Opens an audio device. To close the device, it is necessary to release
     * references to the returned device object.
     *
     * @param device device name.
     * @return retval operation completion status. Returns INVALID_ARGUMENTS
     *         if there is no corresponding hardware module found,
     *         NOT_INITIALIZED if an error occured while opening the hardware
     *         module.
     * @return result the interface for the created device.
     */
    openDevice(string device) generates (Result retval, IDevice result);

    /**
     * Opens the Primary audio device that must be present.
     * This function is not optional and must return successfully the primary device.
     *
     * This device must have the name "primary".
     *
     * The telephony stack uses this device to control the audio during a voice call.
     *
     * @return retval operation completion status. Must be SUCCESS.
     *         For debuging, return INVALID_ARGUMENTS if there is no corresponding
     *         hardware module found, NOT_INITIALIZED if an error occurred
     *         while opening the hardware module.
     * @return result the interface for the created device.
     */
    openPrimaryDevice() generates (Result retval, IPrimaryDevice result);
};