shared/config/audio_policy_configuration.xml

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<!--
/*
** Copyright 2017, 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.
*/
-->

<audioPolicyConfiguration version="1.0" xmlns:xi="http://www.w3.org/2001/XInclude">
    <!-- version section contains a “version” tag in the form “major.minor” e.g version=”1.0” -->

    <!-- Global configuration Decalaration -->
    <globalConfiguration speaker_drc_enabled="false"/>

    <modules>
        <!-- Primary Audio HAL -->
        <module name="primary" halVersion="2.0">
            <attachedDevices>
                <item>Speaker</item>
                <item>Built-In Mic</item>
            </attachedDevices>
            <defaultOutputDevice>Speaker</defaultOutputDevice>
            <mixPorts>
                <mixPort name="primary output" role="source" flags="AUDIO_OUTPUT_FLAG_PRIMARY">
                    <profile name="" format="AUDIO_FORMAT_PCM_16_BIT"
                             samplingRates="44100,48000" channelMasks="AUDIO_CHANNEL_OUT_STEREO"/>
                </mixPort>
                <mixPort name="primary input" role="sink">
                    <profile name="" format="AUDIO_FORMAT_PCM_16_BIT"
                             samplingRates="8000,11025,12000,16000,22050,24000,32000,44100,48000"
                             channelMasks="AUDIO_CHANNEL_IN_MONO,AUDIO_CHANNEL_IN_STEREO"/>
                </mixPort>
           </mixPorts>
           <devicePorts>
                <devicePort tagName="Speaker" type="AUDIO_DEVICE_OUT_SPEAKER" role="sink">
                </devicePort>

                <devicePort tagName="Built-In Mic" type="AUDIO_DEVICE_IN_BUILTIN_MIC" role="source">
                </devicePort>
            </devicePorts>
            <routes>
                <route type="mix" sink="Speaker"
                       sources="primary output"/>
                <route type="mix" sink="primary input"
                       sources="Built-In Mic"/>
            </routes>
        </module>

        <!-- Remote Submix Audio HAL -->
        <xi:include href="r_submix_audio_policy_configuration.xml"/>

    </modules>
    <!-- End of Modules section -->

    <!-- Volume section -->

    <xi:include href="audio_policy_volumes.xml"/>
    <xi:include href="default_volume_tables.xml"/>

    <!-- End of Volume section -->

</audioPolicyConfiguration>