diff --git a/audio/aidl/default/Android.bp b/audio/aidl/default/Android.bp
index 78b59d4..19b2397 100644
--- a/audio/aidl/default/Android.bp
+++ b/audio/aidl/default/Android.bp
@@ -73,18 +73,23 @@
         "Configuration.cpp",
         "EngineConfigXmlConverter.cpp",
         "Module.cpp",
+        "ModulePrimary.cpp",
         "SoundDose.cpp",
         "Stream.cpp",
-        "StreamStub.cpp",
         "Telephony.cpp",
+        "alsa/Mixer.cpp",
+        "alsa/ModuleAlsa.cpp",
+        "alsa/StreamAlsa.cpp",
+        "alsa/Utils.cpp",
         "r_submix/ModuleRemoteSubmix.cpp",
         "r_submix/RemoteSubmixUtils.cpp",
         "r_submix/SubmixRoute.cpp",
         "r_submix/StreamRemoteSubmix.cpp",
+        "stub/ModuleStub.cpp",
+        "stub/StreamStub.cpp",
         "usb/ModuleUsb.cpp",
         "usb/StreamUsb.cpp",
         "usb/UsbAlsaMixerControl.cpp",
-        "usb/UsbAlsaUtils.cpp",
     ],
     generated_sources: [
         "audio_policy_configuration_aidl_default",
diff --git a/audio/aidl/default/Configuration.cpp b/audio/aidl/default/Configuration.cpp
index d41ea67..a71c6ea 100644
--- a/audio/aidl/default/Configuration.cpp
+++ b/audio/aidl/default/Configuration.cpp
@@ -144,10 +144,6 @@
 //    - no profiles specified
 //  * "FM Tuner", IN_FM_TUNER
 //    - no profiles specified
-//  * "USB Out", OUT_DEVICE, CONNECTION_USB
-//    - no profiles specified
-//  * "USB In", IN_DEVICE, CONNECTION_USB
-//    - no profiles specified
 //
 // Mix ports:
 //  * "primary output", PRIMARY, 1 max open, 1 max active stream
@@ -172,8 +168,7 @@
 //
 // Routes:
 //  "primary out", "compressed offload" -> "Speaker"
-//  "primary out", "compressed offload" -> "USB Out"
-//  "Built-in Mic", "USB In" -> "primary input"
+//  "Built-in Mic" -> "primary input"
 //  "telephony_tx" -> "Telephony Tx"
 //  "Telephony Rx" -> "telephony_rx"
 //  "FM Tuner" -> "fm_tuner"
@@ -185,14 +180,6 @@
 //  * "Telephony Rx" device port: PCM 24-bit; MONO; 48000
 //  * "FM Tuner" device port: PCM 24-bit; STEREO; 48000
 //
-// Profiles for device port connected state:
-//  * USB Out":
-//    - profile PCM 16-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
-//    - profile PCM 24-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
-//  * USB In":
-//    - profile PCM 16-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
-//    - profile PCM 24-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
-//
 std::unique_ptr<Configuration> getPrimaryConfiguration() {
     static const Configuration configuration = []() {
         const std::vector<AudioProfile> standardPcmAudioProfiles = {
@@ -252,19 +239,6 @@
                                  AudioChannelLayout::LAYOUT_STEREO, 48000, 0, true,
                                  createDeviceExt(AudioDeviceType::IN_FM_TUNER, 0)));
 
-        AudioPort usbOutDevice =
-                createPort(c.nextPortId++, "USB Out", 0, false,
-                           createDeviceExt(AudioDeviceType::OUT_DEVICE, 0,
-                                           AudioDeviceDescription::CONNECTION_USB));
-        c.ports.push_back(usbOutDevice);
-        c.connectedProfiles[usbOutDevice.id] = standardPcmAudioProfiles;
-
-        AudioPort usbInDevice = createPort(c.nextPortId++, "USB In", 0, true,
-                                           createDeviceExt(AudioDeviceType::IN_DEVICE, 0,
-                                                           AudioDeviceDescription::CONNECTION_USB));
-        c.ports.push_back(usbInDevice);
-        c.connectedProfiles[usbInDevice.id] = standardPcmAudioProfiles;
-
         // Mix ports
 
         AudioPort primaryOutMix = createPort(c.nextPortId++, "primary output",
@@ -323,8 +297,7 @@
         c.ports.push_back(fmTunerInMix);
 
         c.routes.push_back(createRoute({primaryOutMix, compressedOffloadOutMix}, speakerOutDevice));
-        c.routes.push_back(createRoute({primaryOutMix, compressedOffloadOutMix}, usbOutDevice));
-        c.routes.push_back(createRoute({micInDevice, usbInDevice}, primaryInMix));
+        c.routes.push_back(createRoute({micInDevice}, primaryInMix));
         c.routes.push_back(createRoute({telephonyTxOutMix}, telephonyTxOutDevice));
         c.routes.push_back(createRoute({telephonyRxInDevice}, telephonyRxInMix));
         c.routes.push_back(createRoute({fmTunerInDevice}, fmTunerInMix));
@@ -406,22 +379,31 @@
 // Usb configuration:
 //
 // Device ports:
+//  * "USB Device Out", OUT_DEVICE, CONNECTION_USB
+//    - no profiles specified
 //  * "USB Headset Out", OUT_HEADSET, CONNECTION_USB
 //    - no profiles specified
+//  * "USB Device In", IN_DEVICE, CONNECTION_USB
+//    - no profiles specified
 //  * "USB Headset In", IN_HEADSET, CONNECTION_USB
 //    - no profiles specified
 //
 // Mix ports:
-//  * "usb_headset output", 1 max open, 1 max active stream
+//  * "usb_device output", 1 max open, 1 max active stream
 //    - no profiles specified
-//  * "usb_headset input", 1 max open, 1 max active stream
+//  * "usb_device input", 1 max open, 1 max active stream
 //    - no profiles specified
 //
+// Routes:
+//  * "usb_device output" -> "USB Device Out"
+//  * "usb_device output" -> "USB Headset Out"
+//  * "USB Device In", "USB Headset In" -> "usb_device input"
+//
 // Profiles for device port connected state:
-//  * USB Headset Out":
+//  * "USB Device Out", "USB Headset Out":
 //    - profile PCM 16-bit; MONO, STEREO, INDEX_MASK_1, INDEX_MASK_2; 44100, 48000
 //    - profile PCM 24-bit; MONO, STEREO, INDEX_MASK_1, INDEX_MASK_2; 44100, 48000
-//  * USB Headset In":
+//  * "USB Device In", "USB Headset In":
 //    - profile PCM 16-bit; MONO, STEREO, INDEX_MASK_1, INDEX_MASK_2; 44100, 48000
 //    - profile PCM 24-bit; MONO, STEREO, INDEX_MASK_1, INDEX_MASK_2; 44100, 48000
 //
@@ -440,6 +422,13 @@
 
         // Device ports
 
+        AudioPort usbOutDevice =
+                createPort(c.nextPortId++, "USB Device Out", 0, false,
+                           createDeviceExt(AudioDeviceType::OUT_DEVICE, 0,
+                                           AudioDeviceDescription::CONNECTION_USB));
+        c.ports.push_back(usbOutDevice);
+        c.connectedProfiles[usbOutDevice.id] = standardPcmAudioProfiles;
+
         AudioPort usbOutHeadset =
                 createPort(c.nextPortId++, "USB Headset Out", 0, false,
                            createDeviceExt(AudioDeviceType::OUT_HEADSET, 0,
@@ -447,6 +436,12 @@
         c.ports.push_back(usbOutHeadset);
         c.connectedProfiles[usbOutHeadset.id] = standardPcmAudioProfiles;
 
+        AudioPort usbInDevice = createPort(c.nextPortId++, "USB Device In", 0, true,
+                                           createDeviceExt(AudioDeviceType::IN_DEVICE, 0,
+                                                           AudioDeviceDescription::CONNECTION_USB));
+        c.ports.push_back(usbInDevice);
+        c.connectedProfiles[usbInDevice.id] = standardPcmAudioProfiles;
+
         AudioPort usbInHeadset =
                 createPort(c.nextPortId++, "USB Headset In", 0, true,
                            createDeviceExt(AudioDeviceType::IN_HEADSET, 0,
@@ -456,16 +451,110 @@
 
         // Mix ports
 
-        AudioPort usbHeadsetOutMix =
-                createPort(c.nextPortId++, "usb_headset output", 0, false, createPortMixExt(1, 1));
-        c.ports.push_back(usbHeadsetOutMix);
+        AudioPort usbDeviceOutMix =
+                createPort(c.nextPortId++, "usb_device output", 0, false, createPortMixExt(1, 1));
+        c.ports.push_back(usbDeviceOutMix);
 
-        AudioPort usbHeadsetInMix =
-                createPort(c.nextPortId++, "usb_headset input", 0, true, createPortMixExt(1, 1));
-        c.ports.push_back(usbHeadsetInMix);
+        AudioPort usbDeviceInMix =
+                createPort(c.nextPortId++, "usb_device input", 0, true, createPortMixExt(1, 1));
+        c.ports.push_back(usbDeviceInMix);
 
-        c.routes.push_back(createRoute({usbHeadsetOutMix}, usbOutHeadset));
-        c.routes.push_back(createRoute({usbInHeadset}, usbHeadsetInMix));
+        c.routes.push_back(createRoute({usbDeviceOutMix}, usbOutDevice));
+        c.routes.push_back(createRoute({usbDeviceOutMix}, usbOutHeadset));
+        c.routes.push_back(createRoute({usbInDevice, usbInHeadset}, usbDeviceInMix));
+
+        return c;
+    }();
+    return std::make_unique<Configuration>(configuration);
+}
+
+// Stub configuration:
+//
+// Device ports:
+//  * "Test Out", OUT_AFE_PROXY
+//    - no profiles specified
+//  * "Test In", IN_AFE_PROXY
+//    - no profiles specified
+//
+// Mix ports:
+//  * "test output", 1 max open, 1 max active stream
+//    - profile PCM 24-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
+//  * "compressed offload", DIRECT|COMPRESS_OFFLOAD|NON_BLOCKING, 1 max open, 1 max active stream
+//    - profile MP3; MONO, STEREO; 44100, 48000
+//  * "test input", 2 max open, 2 max active streams
+//    - profile PCM 24-bit; MONO, STEREO, FRONT_BACK;
+//        8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000
+//
+// Routes:
+//  "test output", "compressed offload" -> "Test Out"
+//  "Test In" -> "test input"
+//
+// Initial port configs:
+//  * "Test Out" device port: PCM 24-bit; STEREO; 48000
+//  * "Test In" device port: PCM 24-bit; MONO; 48000
+//
+std::unique_ptr<Configuration> getStubConfiguration() {
+    static const Configuration configuration = []() {
+        Configuration c;
+
+        // Device ports
+
+        AudioPort testOutDevice = createPort(c.nextPortId++, "Test Out", 0, false,
+                                             createDeviceExt(AudioDeviceType::OUT_AFE_PROXY, 0));
+        c.ports.push_back(testOutDevice);
+        c.initialConfigs.push_back(
+                createPortConfig(testOutDevice.id, testOutDevice.id, PcmType::INT_24_BIT,
+                                 AudioChannelLayout::LAYOUT_STEREO, 48000, 0, false,
+                                 createDeviceExt(AudioDeviceType::OUT_AFE_PROXY, 0)));
+
+        AudioPort testInDevice = createPort(c.nextPortId++, "Test In", 0, true,
+                                            createDeviceExt(AudioDeviceType::IN_AFE_PROXY, 0));
+        c.ports.push_back(testInDevice);
+        c.initialConfigs.push_back(
+                createPortConfig(testInDevice.id, testInDevice.id, PcmType::INT_24_BIT,
+                                 AudioChannelLayout::LAYOUT_MONO, 48000, 0, true,
+                                 createDeviceExt(AudioDeviceType::IN_AFE_PROXY, 0)));
+
+        // Mix ports
+
+        AudioPort testOutMix =
+                createPort(c.nextPortId++, "test output", 0, false, createPortMixExt(1, 1));
+        testOutMix.profiles.push_back(
+                createProfile(PcmType::INT_24_BIT,
+                              {AudioChannelLayout::LAYOUT_MONO, AudioChannelLayout::LAYOUT_STEREO},
+                              {8000, 11025, 16000, 32000, 44100, 48000}));
+        c.ports.push_back(testOutMix);
+
+        AudioPort compressedOffloadOutMix =
+                createPort(c.nextPortId++, "compressed offload",
+                           makeBitPositionFlagMask({AudioOutputFlags::DIRECT,
+                                                    AudioOutputFlags::COMPRESS_OFFLOAD,
+                                                    AudioOutputFlags::NON_BLOCKING}),
+                           false, createPortMixExt(1, 1));
+        compressedOffloadOutMix.profiles.push_back(
+                createProfile(::android::MEDIA_MIMETYPE_AUDIO_MPEG,
+                              {AudioChannelLayout::LAYOUT_MONO, AudioChannelLayout::LAYOUT_STEREO},
+                              {44100, 48000}));
+        c.ports.push_back(compressedOffloadOutMix);
+
+        AudioPort testInMIx =
+                createPort(c.nextPortId++, "test input", 0, true, createPortMixExt(2, 2));
+        testInMIx.profiles.push_back(
+                createProfile(PcmType::INT_16_BIT,
+                              {AudioChannelLayout::LAYOUT_MONO, AudioChannelLayout::LAYOUT_STEREO,
+                               AudioChannelLayout::LAYOUT_FRONT_BACK},
+                              {8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000}));
+        testInMIx.profiles.push_back(
+                createProfile(PcmType::INT_24_BIT,
+                              {AudioChannelLayout::LAYOUT_MONO, AudioChannelLayout::LAYOUT_STEREO,
+                               AudioChannelLayout::LAYOUT_FRONT_BACK},
+                              {8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000}));
+        c.ports.push_back(testInMIx);
+
+        c.routes.push_back(createRoute({testOutMix, compressedOffloadOutMix}, testOutDevice));
+        c.routes.push_back(createRoute({testInDevice}, testInMIx));
+
+        c.portConfigs.insert(c.portConfigs.end(), c.initialConfigs.begin(), c.initialConfigs.end());
 
         return c;
     }();
diff --git a/audio/aidl/default/Module.cpp b/audio/aidl/default/Module.cpp
index 48d1458..12bbbb0 100644
--- a/audio/aidl/default/Module.cpp
+++ b/audio/aidl/default/Module.cpp
@@ -25,13 +25,12 @@
 #include <android/binder_ibinder_platform.h>
 #include <error/expected_utils.h>
 
-#include "core-impl/Bluetooth.h"
 #include "core-impl/Module.h"
+#include "core-impl/ModulePrimary.h"
 #include "core-impl/ModuleRemoteSubmix.h"
+#include "core-impl/ModuleStub.h"
 #include "core-impl/ModuleUsb.h"
 #include "core-impl/SoundDose.h"
-#include "core-impl/StreamStub.h"
-#include "core-impl/Telephony.h"
 #include "core-impl/utils.h"
 
 using aidl::android::hardware::audio::common::getFrameSizeInBytes;
@@ -110,13 +109,14 @@
 // static
 std::shared_ptr<Module> Module::createInstance(Type type) {
     switch (type) {
-        case Module::Type::USB:
-            return ndk::SharedRefBase::make<ModuleUsb>(type);
-        case Type::R_SUBMIX:
-            return ndk::SharedRefBase::make<ModuleRemoteSubmix>(type);
         case Type::DEFAULT:
-        default:
-            return ndk::SharedRefBase::make<Module>(type);
+            return ndk::SharedRefBase::make<ModulePrimary>();
+        case Type::R_SUBMIX:
+            return ndk::SharedRefBase::make<ModuleRemoteSubmix>();
+        case Type::STUB:
+            return ndk::SharedRefBase::make<ModuleStub>();
+        case Type::USB:
+            return ndk::SharedRefBase::make<ModuleUsb>();
     }
 }
 
@@ -128,6 +128,9 @@
         case Module::Type::R_SUBMIX:
             os << "r_submix";
             break;
+        case Module::Type::STUB:
+            os << "stub";
+            break;
         case Module::Type::USB:
             os << "usb";
             break;
@@ -292,6 +295,9 @@
             case Type::R_SUBMIX:
                 mConfig = std::move(internal::getRSubmixConfiguration());
                 break;
+            case Type::STUB:
+                mConfig = std::move(internal::getStubConfiguration());
+                break;
             case Type::USB:
                 mConfig = std::move(internal::getUsbConfiguration());
                 break;
@@ -395,38 +401,26 @@
 }
 
 ndk::ScopedAStatus Module::getTelephony(std::shared_ptr<ITelephony>* _aidl_return) {
-    if (!mTelephony) {
-        mTelephony = ndk::SharedRefBase::make<Telephony>();
-    }
-    *_aidl_return = mTelephony.getPtr();
-    LOG(DEBUG) << __func__ << ": returning instance of ITelephony: " << _aidl_return->get();
+    *_aidl_return = nullptr;
+    LOG(DEBUG) << __func__ << ": returning null";
     return ndk::ScopedAStatus::ok();
 }
 
 ndk::ScopedAStatus Module::getBluetooth(std::shared_ptr<IBluetooth>* _aidl_return) {
-    if (!mBluetooth) {
-        mBluetooth = ndk::SharedRefBase::make<Bluetooth>();
-    }
-    *_aidl_return = mBluetooth.getPtr();
-    LOG(DEBUG) << __func__ << ": returning instance of IBluetooth: " << _aidl_return->get();
+    *_aidl_return = nullptr;
+    LOG(DEBUG) << __func__ << ": returning null";
     return ndk::ScopedAStatus::ok();
 }
 
 ndk::ScopedAStatus Module::getBluetoothA2dp(std::shared_ptr<IBluetoothA2dp>* _aidl_return) {
-    if (!mBluetoothA2dp) {
-        mBluetoothA2dp = ndk::SharedRefBase::make<BluetoothA2dp>();
-    }
-    *_aidl_return = mBluetoothA2dp.getPtr();
-    LOG(DEBUG) << __func__ << ": returning instance of IBluetoothA2dp: " << _aidl_return->get();
+    *_aidl_return = nullptr;
+    LOG(DEBUG) << __func__ << ": returning null";
     return ndk::ScopedAStatus::ok();
 }
 
 ndk::ScopedAStatus Module::getBluetoothLe(std::shared_ptr<IBluetoothLe>* _aidl_return) {
-    if (!mBluetoothLe) {
-        mBluetoothLe = ndk::SharedRefBase::make<BluetoothLe>();
-    }
-    *_aidl_return = mBluetoothLe.getPtr();
-    LOG(DEBUG) << __func__ << ": returning instance of IBluetoothLe: " << _aidl_return->get();
+    *_aidl_return = nullptr;
+    LOG(DEBUG) << __func__ << ": returning null";
     return ndk::ScopedAStatus::ok();
 }
 
@@ -1334,22 +1328,6 @@
     return mIsMmapSupported.value();
 }
 
-ndk::ScopedAStatus Module::createInputStream(const SinkMetadata& sinkMetadata,
-                                             StreamContext&& context,
-                                             const std::vector<MicrophoneInfo>& microphones,
-                                             std::shared_ptr<StreamIn>* result) {
-    return createStreamInstance<StreamInStub>(result, sinkMetadata, std::move(context),
-                                              microphones);
-}
-
-ndk::ScopedAStatus Module::createOutputStream(const SourceMetadata& sourceMetadata,
-                                              StreamContext&& context,
-                                              const std::optional<AudioOffloadInfo>& offloadInfo,
-                                              std::shared_ptr<StreamOut>* result) {
-    return createStreamInstance<StreamOutStub>(result, sourceMetadata, std::move(context),
-                                               offloadInfo);
-}
-
 ndk::ScopedAStatus Module::populateConnectedDevicePort(AudioPort* audioPort __unused) {
     LOG(VERBOSE) << __func__ << ": do nothing and return ok";
     return ndk::ScopedAStatus::ok();
diff --git a/audio/aidl/default/ModulePrimary.cpp b/audio/aidl/default/ModulePrimary.cpp
new file mode 100644
index 0000000..cbb6730
--- /dev/null
+++ b/audio/aidl/default/ModulePrimary.cpp
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#include <vector>
+
+#define LOG_TAG "AHAL_ModulePrimary"
+#include <Utils.h>
+#include <android-base/logging.h>
+
+#include "core-impl/ModulePrimary.h"
+#include "core-impl/StreamStub.h"
+#include "core-impl/Telephony.h"
+
+using aidl::android::hardware::audio::common::SinkMetadata;
+using aidl::android::hardware::audio::common::SourceMetadata;
+using aidl::android::media::audio::common::AudioOffloadInfo;
+using aidl::android::media::audio::common::AudioPort;
+using aidl::android::media::audio::common::AudioPortConfig;
+using aidl::android::media::audio::common::MicrophoneInfo;
+
+namespace aidl::android::hardware::audio::core {
+
+ndk::ScopedAStatus ModulePrimary::getTelephony(std::shared_ptr<ITelephony>* _aidl_return) {
+    if (!mTelephony) {
+        mTelephony = ndk::SharedRefBase::make<Telephony>();
+    }
+    *_aidl_return = mTelephony.getPtr();
+    LOG(DEBUG) << __func__ << ": returning instance of ITelephony: " << _aidl_return->get();
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ModulePrimary::createInputStream(const SinkMetadata& sinkMetadata,
+                                                    StreamContext&& context,
+                                                    const std::vector<MicrophoneInfo>& microphones,
+                                                    std::shared_ptr<StreamIn>* result) {
+    return createStreamInstance<StreamInStub>(result, sinkMetadata, std::move(context),
+                                              microphones);
+}
+
+ndk::ScopedAStatus ModulePrimary::createOutputStream(
+        const SourceMetadata& sourceMetadata, StreamContext&& context,
+        const std::optional<AudioOffloadInfo>& offloadInfo, std::shared_ptr<StreamOut>* result) {
+    return createStreamInstance<StreamOutStub>(result, sourceMetadata, std::move(context),
+                                               offloadInfo);
+}
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/Stream.cpp b/audio/aidl/default/Stream.cpp
index 251dea0..215de94 100644
--- a/audio/aidl/default/Stream.cpp
+++ b/audio/aidl/default/Stream.cpp
@@ -110,10 +110,12 @@
     if (isConnected) {
         reply->observable.frames = mFrameCount;
         reply->observable.timeNs = ::android::elapsedRealtimeNano();
-    } else {
-        reply->observable.frames = StreamDescriptor::Position::UNKNOWN;
-        reply->observable.timeNs = StreamDescriptor::Position::UNKNOWN;
+        if (auto status = mDriver->getPosition(&reply->observable); status == ::android::OK) {
+            return;
+        }
     }
+    reply->observable.frames = StreamDescriptor::Position::UNKNOWN;
+    reply->observable.timeNs = StreamDescriptor::Position::UNKNOWN;
 }
 
 void StreamWorkerCommonLogic::populateReplyWrongState(
diff --git a/audio/aidl/default/alsa/Mixer.cpp b/audio/aidl/default/alsa/Mixer.cpp
new file mode 100644
index 0000000..f0393e3
--- /dev/null
+++ b/audio/aidl/default/alsa/Mixer.cpp
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#define LOG_TAG "AHAL_AlsaMixer"
+#include <android-base/logging.h>
+
+#include <cmath>
+
+#include <android/binder_status.h>
+
+#include "Mixer.h"
+
+namespace aidl::android::hardware::audio::core::alsa {
+
+//-----------------------------------------------------------------------------
+
+MixerControl::MixerControl(struct mixer_ctl* ctl)
+    : mCtl(ctl),
+      mNumValues(mixer_ctl_get_num_values(ctl)),
+      mMinValue(mixer_ctl_get_range_min(ctl)),
+      mMaxValue(mixer_ctl_get_range_max(ctl)) {}
+
+unsigned int MixerControl::getNumValues() const {
+    return mNumValues;
+}
+
+int MixerControl::getMaxValue() const {
+    return mMaxValue;
+}
+
+int MixerControl::getMinValue() const {
+    return mMinValue;
+}
+
+int MixerControl::setArray(const void* array, size_t count) {
+    const std::lock_guard guard(mLock);
+    return mixer_ctl_set_array(mCtl, array, count);
+}
+
+//-----------------------------------------------------------------------------
+
+// static
+const std::map<Mixer::Control, std::vector<Mixer::ControlNamesAndExpectedCtlType>>
+        Mixer::kPossibleControls = {
+                {Mixer::MASTER_SWITCH, {{"Master Playback Switch", MIXER_CTL_TYPE_BOOL}}},
+                {Mixer::MASTER_VOLUME, {{"Master Playback Volume", MIXER_CTL_TYPE_INT}}},
+                {Mixer::HW_VOLUME,
+                 {{"Headphone Playback Volume", MIXER_CTL_TYPE_INT},
+                  {"Headset Playback Volume", MIXER_CTL_TYPE_INT},
+                  {"PCM Playback Volume", MIXER_CTL_TYPE_INT}}}};
+
+// static
+std::map<Mixer::Control, std::shared_ptr<MixerControl>> Mixer::initializeMixerControls(
+        struct mixer* mixer) {
+    std::map<Mixer::Control, std::shared_ptr<MixerControl>> mixerControls;
+    std::string mixerCtlNames;
+    for (const auto& [control, possibleCtls] : kPossibleControls) {
+        for (const auto& [ctlName, expectedCtlType] : possibleCtls) {
+            struct mixer_ctl* ctl = mixer_get_ctl_by_name(mixer, ctlName.c_str());
+            if (ctl != nullptr && mixer_ctl_get_type(ctl) == expectedCtlType) {
+                mixerControls.emplace(control, std::make_unique<MixerControl>(ctl));
+                if (!mixerCtlNames.empty()) {
+                    mixerCtlNames += ",";
+                }
+                mixerCtlNames += ctlName;
+                break;
+            }
+        }
+    }
+    LOG(DEBUG) << __func__ << ": available mixer control names=[" << mixerCtlNames << "]";
+    return mixerControls;
+}
+
+Mixer::Mixer(struct mixer* mixer)
+    : mMixer(mixer), mMixerControls(initializeMixerControls(mMixer)) {}
+
+Mixer::~Mixer() {
+    mixer_close(mMixer);
+}
+
+namespace {
+
+int volumeFloatToInteger(float fValue, int maxValue, int minValue) {
+    return minValue + std::ceil((maxValue - minValue) * fValue);
+}
+
+}  // namespace
+
+ndk::ScopedAStatus Mixer::setMasterMute(bool muted) {
+    auto it = mMixerControls.find(Mixer::MASTER_SWITCH);
+    if (it == mMixerControls.end()) {
+        return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+    }
+    const int numValues = it->second->getNumValues();
+    std::vector<int> values(numValues, muted ? 0 : 1);
+    if (int err = it->second->setArray(values.data(), numValues); err != 0) {
+        LOG(ERROR) << __func__ << ": failed to set master mute, err=" << err;
+        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
+    }
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus Mixer::setMasterVolume(float volume) {
+    auto it = mMixerControls.find(Mixer::MASTER_VOLUME);
+    if (it == mMixerControls.end()) {
+        return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+    }
+    const int numValues = it->second->getNumValues();
+    std::vector<int> values(numValues, volumeFloatToInteger(volume, it->second->getMaxValue(),
+                                                            it->second->getMinValue()));
+    if (int err = it->second->setArray(values.data(), numValues); err != 0) {
+        LOG(ERROR) << __func__ << ": failed to set master volume, err=" << err;
+        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
+    }
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus Mixer::setVolumes(const std::vector<float>& volumes) {
+    auto it = mMixerControls.find(Mixer::HW_VOLUME);
+    if (it == mMixerControls.end()) {
+        return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+    }
+    const int numValues = it->second->getNumValues();
+    if (numValues < 0) {
+        LOG(FATAL) << __func__ << ": negative number of values: " << numValues;
+    }
+    const int maxValue = it->second->getMaxValue();
+    const int minValue = it->second->getMinValue();
+    std::vector<int> values;
+    size_t i = 0;
+    for (; i < static_cast<size_t>(numValues) && i < values.size(); ++i) {
+        values.emplace_back(volumeFloatToInteger(volumes[i], maxValue, minValue));
+    }
+    if (int err = it->second->setArray(values.data(), values.size()); err != 0) {
+        LOG(ERROR) << __func__ << ": failed to set volume, err=" << err;
+        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
+    }
+    return ndk::ScopedAStatus::ok();
+}
+
+}  // namespace aidl::android::hardware::audio::core::alsa
diff --git a/audio/aidl/default/alsa/Mixer.h b/audio/aidl/default/alsa/Mixer.h
new file mode 100644
index 0000000..de9e6f4
--- /dev/null
+++ b/audio/aidl/default/alsa/Mixer.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#pragma once
+
+#include <map>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <vector>
+
+#include <android-base/thread_annotations.h>
+#include <android/binder_auto_utils.h>
+
+extern "C" {
+#include <tinyalsa/mixer.h>
+}
+
+namespace aidl::android::hardware::audio::core::alsa {
+
+class MixerControl {
+  public:
+    explicit MixerControl(struct mixer_ctl* ctl);
+
+    unsigned int getNumValues() const;
+    int getMaxValue() const;
+    int getMinValue() const;
+    int setArray(const void* array, size_t count);
+
+  private:
+    std::mutex mLock;
+    // The mixer_ctl object is owned by ALSA and will be released when the mixer is closed.
+    struct mixer_ctl* mCtl GUARDED_BY(mLock);
+    const unsigned int mNumValues;
+    const int mMinValue;
+    const int mMaxValue;
+};
+
+class Mixer {
+  public:
+    explicit Mixer(struct mixer* mixer);
+
+    ~Mixer();
+
+    bool isValid() const { return mMixer != nullptr; }
+
+    ndk::ScopedAStatus setMasterMute(bool muted);
+    ndk::ScopedAStatus setMasterVolume(float volume);
+    ndk::ScopedAStatus setVolumes(const std::vector<float>& volumes);
+
+  private:
+    enum Control {
+        MASTER_SWITCH,
+        MASTER_VOLUME,
+        HW_VOLUME,
+    };
+    using ControlNamesAndExpectedCtlType = std::pair<std::string, enum mixer_ctl_type>;
+    static const std::map<Control, std::vector<ControlNamesAndExpectedCtlType>> kPossibleControls;
+    static std::map<Control, std::shared_ptr<MixerControl>> initializeMixerControls(
+            struct mixer* mixer);
+
+    // The mixer object is owned by ALSA and will be released when the mixer is closed.
+    struct mixer* mMixer;
+    // `mMixerControls` will only be initialized in constructor. After that, it wil only be
+    // read but not be modified.
+    const std::map<Control, std::shared_ptr<MixerControl>> mMixerControls;
+};
+
+}  // namespace aidl::android::hardware::audio::core::alsa
diff --git a/audio/aidl/default/alsa/ModuleAlsa.cpp b/audio/aidl/default/alsa/ModuleAlsa.cpp
new file mode 100644
index 0000000..8e75d56
--- /dev/null
+++ b/audio/aidl/default/alsa/ModuleAlsa.cpp
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#define LOG_TAG "AHAL_ModuleAlsa"
+
+#include <vector>
+
+#include <android-base/logging.h>
+
+#include "Utils.h"
+#include "core-impl/ModuleAlsa.h"
+
+extern "C" {
+#include "alsa_device_profile.h"
+}
+
+using aidl::android::media::audio::common::AudioChannelLayout;
+using aidl::android::media::audio::common::AudioFormatType;
+using aidl::android::media::audio::common::AudioPort;
+using aidl::android::media::audio::common::AudioProfile;
+
+namespace aidl::android::hardware::audio::core {
+
+ndk::ScopedAStatus ModuleAlsa::populateConnectedDevicePort(AudioPort* audioPort) {
+    auto deviceProfile = alsa::getDeviceProfile(*audioPort);
+    if (!deviceProfile.has_value()) {
+        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+    auto profile = alsa::readAlsaDeviceInfo(*deviceProfile);
+    if (!profile.has_value()) {
+        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
+    }
+
+    std::vector<AudioChannelLayout> channels = alsa::getChannelMasksFromProfile(&profile.value());
+    std::vector<int> sampleRates = alsa::getSampleRatesFromProfile(&profile.value());
+
+    for (size_t i = 0; i < std::min(MAX_PROFILE_FORMATS, AUDIO_PORT_MAX_AUDIO_PROFILES) &&
+                       profile->formats[i] != PCM_FORMAT_INVALID;
+         ++i) {
+        auto audioFormatDescription =
+                alsa::c2aidl_pcm_format_AudioFormatDescription(profile->formats[i]);
+        if (audioFormatDescription.type == AudioFormatType::DEFAULT) {
+            LOG(WARNING) << __func__ << ": unknown pcm type=" << profile->formats[i];
+            continue;
+        }
+        AudioProfile audioProfile = {.format = audioFormatDescription,
+                                     .channelMasks = channels,
+                                     .sampleRates = sampleRates};
+        audioPort->profiles.push_back(std::move(audioProfile));
+    }
+    return ndk::ScopedAStatus::ok();
+}
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/alsa/StreamAlsa.cpp b/audio/aidl/default/alsa/StreamAlsa.cpp
new file mode 100644
index 0000000..17c7feb
--- /dev/null
+++ b/audio/aidl/default/alsa/StreamAlsa.cpp
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#include <limits>
+
+#define LOG_TAG "AHAL_StreamAlsa"
+#include <android-base/logging.h>
+
+#include <Utils.h>
+#include <audio_utils/clock.h>
+#include <error/expected_utils.h>
+
+#include "core-impl/StreamAlsa.h"
+
+namespace aidl::android::hardware::audio::core {
+
+StreamAlsa::StreamAlsa(const Metadata& metadata, StreamContext&& context)
+    : StreamCommonImpl(metadata, std::move(context)),
+      mFrameSizeBytes(getContext().getFrameSize()),
+      mIsInput(isInput(metadata)),
+      mConfig(alsa::getPcmConfig(getContext(), mIsInput)) {}
+
+::android::status_t StreamAlsa::init() {
+    return mConfig.has_value() ? ::android::OK : ::android::NO_INIT;
+}
+
+::android::status_t StreamAlsa::standby() {
+    mAlsaDeviceProxies.clear();
+    return ::android::OK;
+}
+
+::android::status_t StreamAlsa::start() {
+    decltype(mAlsaDeviceProxies) alsaDeviceProxies;
+    for (const auto& device : getDeviceProfiles()) {
+        auto profile = alsa::readAlsaDeviceInfo(device);
+        if (!profile.has_value()) {
+            LOG(ERROR) << __func__ << ": unable to read device info, device address=" << device;
+            return ::android::UNKNOWN_ERROR;
+        }
+
+        auto proxy = alsa::makeDeviceProxy();
+        // Always ask for alsa configure as required since the configuration should be supported
+        // by the connected device. That is guaranteed by `setAudioPortConfig` and `setAudioPatch`.
+        if (int err = proxy_prepare(proxy.get(), &profile.value(),
+                                    const_cast<struct pcm_config*>(&mConfig.value()),
+                                    true /*require_exact_match*/);
+            err != 0) {
+            LOG(ERROR) << __func__ << ": fail to prepare for device address=" << device
+                       << " error=" << err;
+            return ::android::UNKNOWN_ERROR;
+        }
+        if (int err = proxy_open(proxy.get()); err != 0) {
+            LOG(ERROR) << __func__ << ": failed to open device, address=" << device
+                       << " error=" << err;
+            return ::android::UNKNOWN_ERROR;
+        }
+        alsaDeviceProxies.push_back(std::move(proxy));
+    }
+    mAlsaDeviceProxies = std::move(alsaDeviceProxies);
+    return ::android::OK;
+}
+
+::android::status_t StreamAlsa::transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
+                                         int32_t* latencyMs) {
+    const size_t bytesToTransfer = frameCount * mFrameSizeBytes;
+    unsigned maxLatency = 0;
+    if (mIsInput) {
+        if (mAlsaDeviceProxies.empty()) {
+            LOG(FATAL) << __func__ << ": no input devices";
+            return ::android::NO_INIT;
+        }
+        // For input case, only support single device.
+        proxy_read(mAlsaDeviceProxies[0].get(), buffer, bytesToTransfer);
+        maxLatency = proxy_get_latency(mAlsaDeviceProxies[0].get());
+    } else {
+        for (auto& proxy : mAlsaDeviceProxies) {
+            proxy_write(proxy.get(), buffer, bytesToTransfer);
+            maxLatency = std::max(maxLatency, proxy_get_latency(proxy.get()));
+        }
+    }
+    *actualFrameCount = frameCount;
+    maxLatency = std::min(maxLatency, static_cast<unsigned>(std::numeric_limits<int32_t>::max()));
+    *latencyMs = maxLatency;
+    return ::android::OK;
+}
+
+::android::status_t StreamAlsa::getPosition(StreamDescriptor::Position* position) {
+    if (mAlsaDeviceProxies.empty()) {
+        LOG(FATAL) << __func__ << ": no input devices";
+        return ::android::NO_INIT;
+    }
+    if (mIsInput) {
+        if (int ret = proxy_get_capture_position(mAlsaDeviceProxies[0].get(), &position->frames,
+                                                 &position->timeNs);
+            ret != 0) {
+            LOG(WARNING) << __func__ << ": failed to retrieve capture position: " << ret;
+            return ::android::INVALID_OPERATION;
+        }
+    } else {
+        uint64_t hwFrames;
+        struct timespec timestamp;
+        if (int ret = proxy_get_presentation_position(mAlsaDeviceProxies[0].get(), &hwFrames,
+                                                      &timestamp);
+            ret == 0) {
+            if (hwFrames > std::numeric_limits<int64_t>::max()) {
+                hwFrames -= std::numeric_limits<int64_t>::max();
+            }
+            position->frames = static_cast<int64_t>(hwFrames);
+            position->timeNs = audio_utils_ns_from_timespec(&timestamp);
+        } else {
+            LOG(WARNING) << __func__ << ": failed to retrieve presentation position: " << ret;
+            return ::android::INVALID_OPERATION;
+        }
+    }
+    return ::android::OK;
+}
+
+void StreamAlsa::shutdown() {
+    mAlsaDeviceProxies.clear();
+}
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/alsa/Utils.cpp b/audio/aidl/default/alsa/Utils.cpp
new file mode 100644
index 0000000..162f852
--- /dev/null
+++ b/audio/aidl/default/alsa/Utils.cpp
@@ -0,0 +1,293 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#include <map>
+#include <set>
+
+#define LOG_TAG "AHAL_AlsaUtils"
+#include <Utils.h>
+#include <aidl/android/media/audio/common/AudioFormatType.h>
+#include <aidl/android/media/audio/common/PcmType.h>
+#include <android-base/logging.h>
+
+#include "Utils.h"
+#include "core-impl/utils.h"
+
+using aidl::android::hardware::audio::common::getChannelCount;
+using aidl::android::media::audio::common::AudioChannelLayout;
+using aidl::android::media::audio::common::AudioDeviceAddress;
+using aidl::android::media::audio::common::AudioFormatDescription;
+using aidl::android::media::audio::common::AudioFormatType;
+using aidl::android::media::audio::common::AudioIoFlags;
+using aidl::android::media::audio::common::AudioPortExt;
+using aidl::android::media::audio::common::PcmType;
+
+namespace aidl::android::hardware::audio::core::alsa {
+
+namespace {
+
+using AudioChannelCountToMaskMap = std::map<unsigned int, AudioChannelLayout>;
+using AudioFormatDescToPcmFormatMap = std::map<AudioFormatDescription, enum pcm_format>;
+using PcmFormatToAudioFormatDescMap = std::map<enum pcm_format, AudioFormatDescription>;
+
+AudioChannelLayout getInvalidChannelLayout() {
+    static const AudioChannelLayout invalidChannelLayout =
+            AudioChannelLayout::make<AudioChannelLayout::Tag::invalid>(0);
+    return invalidChannelLayout;
+}
+
+static AudioChannelCountToMaskMap make_ChannelCountToMaskMap(
+        const std::set<AudioChannelLayout>& channelMasks) {
+    AudioChannelCountToMaskMap channelMaskToCountMap;
+    for (const auto& channelMask : channelMasks) {
+        channelMaskToCountMap.emplace(getChannelCount(channelMask), channelMask);
+    }
+    return channelMaskToCountMap;
+}
+
+#define DEFINE_CHANNEL_LAYOUT_MASK(n) \
+    AudioChannelLayout::make<AudioChannelLayout::Tag::layoutMask>(AudioChannelLayout::LAYOUT_##n)
+
+const AudioChannelCountToMaskMap& getSupportedChannelOutLayoutMap() {
+    static const std::set<AudioChannelLayout> supportedOutChannelLayouts = {
+            DEFINE_CHANNEL_LAYOUT_MASK(MONO),          DEFINE_CHANNEL_LAYOUT_MASK(STEREO),
+            DEFINE_CHANNEL_LAYOUT_MASK(2POINT1),       DEFINE_CHANNEL_LAYOUT_MASK(QUAD),
+            DEFINE_CHANNEL_LAYOUT_MASK(PENTA),         DEFINE_CHANNEL_LAYOUT_MASK(5POINT1),
+            DEFINE_CHANNEL_LAYOUT_MASK(6POINT1),       DEFINE_CHANNEL_LAYOUT_MASK(7POINT1),
+            DEFINE_CHANNEL_LAYOUT_MASK(7POINT1POINT4), DEFINE_CHANNEL_LAYOUT_MASK(22POINT2),
+    };
+    static const AudioChannelCountToMaskMap outLayouts =
+            make_ChannelCountToMaskMap(supportedOutChannelLayouts);
+    return outLayouts;
+}
+
+const AudioChannelCountToMaskMap& getSupportedChannelInLayoutMap() {
+    static const std::set<AudioChannelLayout> supportedInChannelLayouts = {
+            DEFINE_CHANNEL_LAYOUT_MASK(MONO),
+            DEFINE_CHANNEL_LAYOUT_MASK(STEREO),
+    };
+    static const AudioChannelCountToMaskMap inLayouts =
+            make_ChannelCountToMaskMap(supportedInChannelLayouts);
+    return inLayouts;
+}
+
+#undef DEFINE_CHANNEL_LAYOUT_MASK
+#define DEFINE_CHANNEL_INDEX_MASK(n) \
+    AudioChannelLayout::make<AudioChannelLayout::Tag::indexMask>(AudioChannelLayout::INDEX_MASK_##n)
+
+const AudioChannelCountToMaskMap& getSupportedChannelIndexLayoutMap() {
+    static const std::set<AudioChannelLayout> supportedIndexChannelLayouts = {
+            DEFINE_CHANNEL_INDEX_MASK(1),  DEFINE_CHANNEL_INDEX_MASK(2),
+            DEFINE_CHANNEL_INDEX_MASK(3),  DEFINE_CHANNEL_INDEX_MASK(4),
+            DEFINE_CHANNEL_INDEX_MASK(5),  DEFINE_CHANNEL_INDEX_MASK(6),
+            DEFINE_CHANNEL_INDEX_MASK(7),  DEFINE_CHANNEL_INDEX_MASK(8),
+            DEFINE_CHANNEL_INDEX_MASK(9),  DEFINE_CHANNEL_INDEX_MASK(10),
+            DEFINE_CHANNEL_INDEX_MASK(11), DEFINE_CHANNEL_INDEX_MASK(12),
+            DEFINE_CHANNEL_INDEX_MASK(13), DEFINE_CHANNEL_INDEX_MASK(14),
+            DEFINE_CHANNEL_INDEX_MASK(15), DEFINE_CHANNEL_INDEX_MASK(16),
+            DEFINE_CHANNEL_INDEX_MASK(17), DEFINE_CHANNEL_INDEX_MASK(18),
+            DEFINE_CHANNEL_INDEX_MASK(19), DEFINE_CHANNEL_INDEX_MASK(20),
+            DEFINE_CHANNEL_INDEX_MASK(21), DEFINE_CHANNEL_INDEX_MASK(22),
+            DEFINE_CHANNEL_INDEX_MASK(23), DEFINE_CHANNEL_INDEX_MASK(24),
+    };
+    static const AudioChannelCountToMaskMap indexLayouts =
+            make_ChannelCountToMaskMap(supportedIndexChannelLayouts);
+    return indexLayouts;
+}
+
+#undef DEFINE_CHANNEL_INDEX_MASK
+
+AudioFormatDescription make_AudioFormatDescription(AudioFormatType type) {
+    AudioFormatDescription result;
+    result.type = type;
+    return result;
+}
+
+AudioFormatDescription make_AudioFormatDescription(PcmType pcm) {
+    auto result = make_AudioFormatDescription(AudioFormatType::PCM);
+    result.pcm = pcm;
+    return result;
+}
+
+const AudioFormatDescToPcmFormatMap& getAudioFormatDescriptorToPcmFormatMap() {
+    static const AudioFormatDescToPcmFormatMap formatDescToPcmFormatMap = {
+            {make_AudioFormatDescription(PcmType::UINT_8_BIT), PCM_FORMAT_S8},
+            {make_AudioFormatDescription(PcmType::INT_16_BIT), PCM_FORMAT_S16_LE},
+            {make_AudioFormatDescription(PcmType::FIXED_Q_8_24), PCM_FORMAT_S24_LE},
+            {make_AudioFormatDescription(PcmType::INT_24_BIT), PCM_FORMAT_S24_3LE},
+            {make_AudioFormatDescription(PcmType::INT_32_BIT), PCM_FORMAT_S32_LE},
+            {make_AudioFormatDescription(PcmType::FLOAT_32_BIT), PCM_FORMAT_FLOAT_LE},
+    };
+    return formatDescToPcmFormatMap;
+}
+
+static PcmFormatToAudioFormatDescMap make_PcmFormatToAudioFormatDescMap(
+        const AudioFormatDescToPcmFormatMap& formatDescToPcmFormatMap) {
+    PcmFormatToAudioFormatDescMap result;
+    for (const auto& formatPair : formatDescToPcmFormatMap) {
+        result.emplace(formatPair.second, formatPair.first);
+    }
+    return result;
+}
+
+const PcmFormatToAudioFormatDescMap& getPcmFormatToAudioFormatDescMap() {
+    static const PcmFormatToAudioFormatDescMap pcmFormatToFormatDescMap =
+            make_PcmFormatToAudioFormatDescMap(getAudioFormatDescriptorToPcmFormatMap());
+    return pcmFormatToFormatDescMap;
+}
+
+}  // namespace
+
+std::ostream& operator<<(std::ostream& os, const DeviceProfile& device) {
+    return os << "<" << device.card << "," << device.device << ">";
+}
+
+AudioChannelLayout getChannelLayoutMaskFromChannelCount(unsigned int channelCount, int isInput) {
+    return findValueOrDefault(
+            isInput ? getSupportedChannelInLayoutMap() : getSupportedChannelOutLayoutMap(),
+            channelCount, getInvalidChannelLayout());
+}
+
+AudioChannelLayout getChannelIndexMaskFromChannelCount(unsigned int channelCount) {
+    return findValueOrDefault(getSupportedChannelIndexLayoutMap(), channelCount,
+                              getInvalidChannelLayout());
+}
+
+unsigned int getChannelCountFromChannelMask(const AudioChannelLayout& channelMask, bool isInput) {
+    switch (channelMask.getTag()) {
+        case AudioChannelLayout::Tag::layoutMask: {
+            return findKeyOrDefault(
+                    isInput ? getSupportedChannelInLayoutMap() : getSupportedChannelOutLayoutMap(),
+                    static_cast<unsigned>(getChannelCount(channelMask)), 0u /*defaultValue*/);
+        }
+        case AudioChannelLayout::Tag::indexMask: {
+            return findKeyOrDefault(getSupportedChannelIndexLayoutMap(),
+                                    static_cast<unsigned>(getChannelCount(channelMask)),
+                                    0u /*defaultValue*/);
+        }
+        case AudioChannelLayout::Tag::none:
+        case AudioChannelLayout::Tag::invalid:
+        case AudioChannelLayout::Tag::voiceMask:
+        default:
+            return 0;
+    }
+}
+
+std::vector<AudioChannelLayout> getChannelMasksFromProfile(const alsa_device_profile* profile) {
+    const bool isInput = profile->direction == PCM_IN;
+    std::vector<AudioChannelLayout> channels;
+    for (size_t i = 0; i < AUDIO_PORT_MAX_CHANNEL_MASKS && profile->channel_counts[i] != 0; ++i) {
+        auto layoutMask =
+                alsa::getChannelLayoutMaskFromChannelCount(profile->channel_counts[i], isInput);
+        if (layoutMask.getTag() == AudioChannelLayout::Tag::layoutMask) {
+            channels.push_back(layoutMask);
+        }
+        auto indexMask = alsa::getChannelIndexMaskFromChannelCount(profile->channel_counts[i]);
+        if (indexMask.getTag() == AudioChannelLayout::Tag::indexMask) {
+            channels.push_back(indexMask);
+        }
+    }
+    return channels;
+}
+
+std::optional<DeviceProfile> getDeviceProfile(
+        const ::aidl::android::media::audio::common::AudioDevice& audioDevice, bool isInput) {
+    if (audioDevice.address.getTag() != AudioDeviceAddress::Tag::alsa) {
+        LOG(ERROR) << __func__ << ": not alsa address: " << audioDevice.toString();
+        return std::nullopt;
+    }
+    auto& alsaAddress = audioDevice.address.get<AudioDeviceAddress::Tag::alsa>();
+    if (alsaAddress.size() != 2 || alsaAddress[0] < 0 || alsaAddress[1] < 0) {
+        LOG(ERROR) << __func__
+                   << ": malformed alsa address: " << ::android::internal::ToString(alsaAddress);
+        return std::nullopt;
+    }
+    return DeviceProfile{.card = alsaAddress[0],
+                         .device = alsaAddress[1],
+                         .direction = isInput ? PCM_IN : PCM_OUT};
+}
+
+std::optional<DeviceProfile> getDeviceProfile(
+        const ::aidl::android::media::audio::common::AudioPort& audioPort) {
+    if (audioPort.ext.getTag() != AudioPortExt::Tag::device) {
+        LOG(ERROR) << __func__ << ": port id " << audioPort.id << " is not a device port";
+        return std::nullopt;
+    }
+    auto& devicePort = audioPort.ext.get<AudioPortExt::Tag::device>();
+    return getDeviceProfile(devicePort.device, audioPort.flags.getTag() == AudioIoFlags::input);
+}
+
+std::optional<struct pcm_config> getPcmConfig(const StreamContext& context, bool isInput) {
+    struct pcm_config config;
+    config.channels = alsa::getChannelCountFromChannelMask(context.getChannelLayout(), isInput);
+    if (config.channels == 0) {
+        LOG(ERROR) << __func__ << ": invalid channel=" << context.getChannelLayout().toString();
+        return std::nullopt;
+    }
+    config.format = alsa::aidl2c_AudioFormatDescription_pcm_format(context.getFormat());
+    if (config.format == PCM_FORMAT_INVALID) {
+        LOG(ERROR) << __func__ << ": invalid format=" << context.getFormat().toString();
+        return std::nullopt;
+    }
+    config.rate = context.getSampleRate();
+    if (config.rate == 0) {
+        LOG(ERROR) << __func__ << ": invalid sample rate=" << config.rate;
+        return std::nullopt;
+    }
+    return config;
+}
+
+std::vector<int> getSampleRatesFromProfile(const alsa_device_profile* profile) {
+    std::vector<int> sampleRates;
+    for (int i = 0; i < std::min(MAX_PROFILE_SAMPLE_RATES, AUDIO_PORT_MAX_SAMPLING_RATES) &&
+                    profile->sample_rates[i] != 0;
+         i++) {
+        sampleRates.push_back(profile->sample_rates[i]);
+    }
+    return sampleRates;
+}
+
+DeviceProxy makeDeviceProxy() {
+    return DeviceProxy(new alsa_device_proxy, [](alsa_device_proxy* proxy) {
+        if (proxy != nullptr) {
+            proxy_close(proxy);
+            delete proxy;
+        }
+    });
+}
+
+std::optional<alsa_device_profile> readAlsaDeviceInfo(const DeviceProfile& deviceProfile) {
+    alsa_device_profile profile;
+    profile_init(&profile, deviceProfile.direction);
+    profile.card = deviceProfile.card;
+    profile.device = deviceProfile.device;
+    if (!profile_read_device_info(&profile)) {
+        LOG(ERROR) << __func__ << ": failed to read device info, card=" << profile.card
+                   << ", device=" << profile.device;
+        return std::nullopt;
+    }
+    return profile;
+}
+
+AudioFormatDescription c2aidl_pcm_format_AudioFormatDescription(enum pcm_format legacy) {
+    return findValueOrDefault(getPcmFormatToAudioFormatDescMap(), legacy, AudioFormatDescription());
+}
+
+pcm_format aidl2c_AudioFormatDescription_pcm_format(const AudioFormatDescription& aidl) {
+    return findValueOrDefault(getAudioFormatDescriptorToPcmFormatMap(), aidl, PCM_FORMAT_INVALID);
+}
+
+}  // namespace aidl::android::hardware::audio::core::alsa
diff --git a/audio/aidl/default/alsa/Utils.h b/audio/aidl/default/alsa/Utils.h
new file mode 100644
index 0000000..c1b9b38
--- /dev/null
+++ b/audio/aidl/default/alsa/Utils.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#pragma once
+
+#include <functional>
+#include <iostream>
+#include <memory>
+#include <optional>
+#include <vector>
+
+#include <aidl/android/media/audio/common/AudioChannelLayout.h>
+#include <aidl/android/media/audio/common/AudioFormatDescription.h>
+#include <aidl/android/media/audio/common/AudioPort.h>
+
+#include "core-impl/Stream.h"
+
+extern "C" {
+#include <tinyalsa/pcm.h>
+#include "alsa_device_profile.h"
+#include "alsa_device_proxy.h"
+}
+
+namespace aidl::android::hardware::audio::core::alsa {
+
+struct DeviceProfile {
+    int card;
+    int device;
+    int direction; /* PCM_OUT or PCM_IN */
+};
+std::ostream& operator<<(std::ostream& os, const DeviceProfile& device);
+using DeviceProxyDeleter = std::function<void(alsa_device_proxy*)>;
+using DeviceProxy = std::unique_ptr<alsa_device_proxy, DeviceProxyDeleter>;
+
+::aidl::android::media::audio::common::AudioChannelLayout getChannelLayoutMaskFromChannelCount(
+        unsigned int channelCount, int isInput);
+::aidl::android::media::audio::common::AudioChannelLayout getChannelIndexMaskFromChannelCount(
+        unsigned int channelCount);
+unsigned int getChannelCountFromChannelMask(
+        const ::aidl::android::media::audio::common::AudioChannelLayout& channelMask, bool isInput);
+std::vector<::aidl::android::media::audio::common::AudioChannelLayout> getChannelMasksFromProfile(
+        const alsa_device_profile* profile);
+std::optional<DeviceProfile> getDeviceProfile(
+        const ::aidl::android::media::audio::common::AudioDevice& audioDevice, bool isInput);
+std::optional<DeviceProfile> getDeviceProfile(
+        const ::aidl::android::media::audio::common::AudioPort& audioPort);
+std::optional<struct pcm_config> getPcmConfig(const StreamContext& context, bool isInput);
+std::vector<int> getSampleRatesFromProfile(const alsa_device_profile* profile);
+DeviceProxy makeDeviceProxy();
+std::optional<alsa_device_profile> readAlsaDeviceInfo(const DeviceProfile& deviceProfile);
+
+::aidl::android::media::audio::common::AudioFormatDescription
+c2aidl_pcm_format_AudioFormatDescription(enum pcm_format legacy);
+pcm_format aidl2c_AudioFormatDescription_pcm_format(
+        const ::aidl::android::media::audio::common::AudioFormatDescription& aidl);
+
+}  // namespace aidl::android::hardware::audio::core::alsa
diff --git a/audio/aidl/default/android.hardware.audio.service-aidl.xml b/audio/aidl/default/android.hardware.audio.service-aidl.xml
index 9636a58..c9d6314 100644
--- a/audio/aidl/default/android.hardware.audio.service-aidl.xml
+++ b/audio/aidl/default/android.hardware.audio.service-aidl.xml
@@ -12,6 +12,11 @@
   <hal format="aidl">
     <name>android.hardware.audio.core</name>
     <version>1</version>
+    <fqname>IModule/stub</fqname>
+  </hal>
+  <hal format="aidl">
+    <name>android.hardware.audio.core</name>
+    <version>1</version>
     <fqname>IModule/usb</fqname>
   </hal>
   <hal format="aidl">
diff --git a/audio/aidl/default/include/core-impl/ChildInterface.h b/audio/aidl/default/include/core-impl/ChildInterface.h
new file mode 100644
index 0000000..1b31691
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/ChildInterface.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#pragma once
+
+#include <memory>
+#include <utility>
+
+#include <android/binder_auto_utils.h>
+#include <android/binder_ibinder_platform.h>
+#include <system/thread_defs.h>
+
+namespace aidl::android::hardware::audio::core {
+
+// Helper used for interfaces that require a persistent instance. We hold them via a strong
+// pointer. The binder token is retained for a call to 'setMinSchedulerPolicy'.
+template <class C>
+struct ChildInterface : private std::pair<std::shared_ptr<C>, ndk::SpAIBinder> {
+    ChildInterface() = default;
+    ChildInterface& operator=(const std::shared_ptr<C>& c) {
+        return operator=(std::shared_ptr<C>(c));
+    }
+    ChildInterface& operator=(std::shared_ptr<C>&& c) {
+        this->first = std::move(c);
+        this->second = this->first->asBinder();
+        AIBinder_setMinSchedulerPolicy(this->second.get(), SCHED_NORMAL, ANDROID_PRIORITY_AUDIO);
+        return *this;
+    }
+    explicit operator bool() const { return !!this->first; }
+    C& operator*() const { return *(this->first); }
+    C* operator->() const { return this->first; }
+    std::shared_ptr<C> getPtr() const { return this->first; }
+};
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/Configuration.h b/audio/aidl/default/include/core-impl/Configuration.h
index 70320e4..25bf7af 100644
--- a/audio/aidl/default/include/core-impl/Configuration.h
+++ b/audio/aidl/default/include/core-impl/Configuration.h
@@ -45,6 +45,7 @@
 
 std::unique_ptr<Configuration> getPrimaryConfiguration();
 std::unique_ptr<Configuration> getRSubmixConfiguration();
+std::unique_ptr<Configuration> getStubConfiguration();
 std::unique_ptr<Configuration> getUsbConfiguration();
 
 }  // namespace aidl::android::hardware::audio::core::internal
diff --git a/audio/aidl/default/include/core-impl/Module.h b/audio/aidl/default/include/core-impl/Module.h
index 4a23637..ee0458b 100644
--- a/audio/aidl/default/include/core-impl/Module.h
+++ b/audio/aidl/default/include/core-impl/Module.h
@@ -16,12 +16,14 @@
 
 #pragma once
 
+#include <iostream>
 #include <map>
 #include <memory>
 #include <set>
 
 #include <aidl/android/hardware/audio/core/BnModule.h>
 
+#include "core-impl/ChildInterface.h"
 #include "core-impl/Configuration.h"
 #include "core-impl/Stream.h"
 
@@ -31,7 +33,7 @@
   public:
     // This value is used for all AudioPatches and reported by all streams.
     static constexpr int32_t kLatencyMs = 10;
-    enum Type : int { DEFAULT, R_SUBMIX, USB };
+    enum Type : int { DEFAULT, R_SUBMIX, STUB, USB };
 
     static std::shared_ptr<Module> createInstance(Type type);
 
@@ -132,26 +134,6 @@
         bool forceTransientBurst = false;
         bool forceSynchronousDrain = false;
     };
-    // Helper used for interfaces that require a persistent instance. We hold them via a strong
-    // pointer. The binder token is retained for a call to 'setMinSchedulerPolicy'.
-    template <class C>
-    struct ChildInterface : private std::pair<std::shared_ptr<C>, ndk::SpAIBinder> {
-        ChildInterface() {}
-        ChildInterface& operator=(const std::shared_ptr<C>& c) {
-            return operator=(std::shared_ptr<C>(c));
-        }
-        ChildInterface& operator=(std::shared_ptr<C>&& c) {
-            this->first = std::move(c);
-            this->second = this->first->asBinder();
-            AIBinder_setMinSchedulerPolicy(this->second.get(), SCHED_NORMAL,
-                                           ANDROID_PRIORITY_AUDIO);
-            return *this;
-        }
-        explicit operator bool() const { return !!this->first; }
-        C& operator*() const { return *(this->first); }
-        C* operator->() const { return this->first; }
-        std::shared_ptr<C> getPtr() const { return this->first; }
-    };
     // ids of device ports created at runtime via 'connectExternalDevice'.
     // Also stores a list of ids of mix ports with dynamic profiles that were populated from
     // the connected port. This list can be empty, thus an int->int multimap can't be used.
@@ -164,10 +146,6 @@
     std::unique_ptr<internal::Configuration> mConfig;
     ModuleDebug mDebug;
     VendorDebug mVendorDebug;
-    ChildInterface<ITelephony> mTelephony;
-    ChildInterface<IBluetooth> mBluetooth;
-    ChildInterface<IBluetoothA2dp> mBluetoothA2dp;
-    ChildInterface<IBluetoothLe> mBluetoothLe;
     ConnectedDevicePorts mConnectedDevicePorts;
     Streams mStreams;
     Patches mPatches;
@@ -184,13 +162,13 @@
             const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
             StreamContext&& context,
             const std::vector<::aidl::android::media::audio::common::MicrophoneInfo>& microphones,
-            std::shared_ptr<StreamIn>* result);
+            std::shared_ptr<StreamIn>* result) = 0;
     virtual ndk::ScopedAStatus createOutputStream(
             const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
             StreamContext&& context,
             const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
                     offloadInfo,
-            std::shared_ptr<StreamOut>* result);
+            std::shared_ptr<StreamOut>* result) = 0;
     // If the module is unable to populate the connected device port correctly, the returned error
     // code must correspond to the errors of `IModule.connectedExternalDevice` method.
     virtual ndk::ScopedAStatus populateConnectedDevicePort(
@@ -232,4 +210,6 @@
                                                    const AudioPatch& newPatch);
 };
 
+std::ostream& operator<<(std::ostream& os, Module::Type t);
+
 }  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/ModuleAlsa.h b/audio/aidl/default/include/core-impl/ModuleAlsa.h
new file mode 100644
index 0000000..5815961
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/ModuleAlsa.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#pragma once
+
+#include "core-impl/Module.h"
+
+namespace aidl::android::hardware::audio::core {
+
+// This class is intended to be used as a base class for implementations
+// that use TinyAlsa. This can be either a primary module or a USB Audio
+// module. This class does not define a complete module implementation,
+// and should never be used on its own. Derived classes are expected to
+// provide necessary overrides for all interface methods omitted here.
+class ModuleAlsa : public Module {
+  public:
+    explicit ModuleAlsa(Module::Type type) : Module(type) {}
+
+  protected:
+    // Extension methods of 'Module'.
+    ndk::ScopedAStatus populateConnectedDevicePort(
+            ::aidl::android::media::audio::common::AudioPort* audioPort) override;
+};
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/ModulePrimary.h b/audio/aidl/default/include/core-impl/ModulePrimary.h
new file mode 100644
index 0000000..bc808ab
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/ModulePrimary.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#pragma once
+
+#include "core-impl/Module.h"
+
+namespace aidl::android::hardware::audio::core {
+
+class ModulePrimary final : public Module {
+  public:
+    ModulePrimary() : Module(Type::DEFAULT) {}
+
+  protected:
+    ndk::ScopedAStatus getTelephony(std::shared_ptr<ITelephony>* _aidl_return) override;
+
+    ndk::ScopedAStatus createInputStream(
+            const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
+            StreamContext&& context,
+            const std::vector<::aidl::android::media::audio::common::MicrophoneInfo>& microphones,
+            std::shared_ptr<StreamIn>* result) override;
+    ndk::ScopedAStatus createOutputStream(
+            const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
+            StreamContext&& context,
+            const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
+                    offloadInfo,
+            std::shared_ptr<StreamOut>* result) override;
+
+  private:
+    ChildInterface<ITelephony> mTelephony;
+};
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/ModuleRemoteSubmix.h b/audio/aidl/default/include/core-impl/ModuleRemoteSubmix.h
index 7b1d375..ccfcdd9 100644
--- a/audio/aidl/default/include/core-impl/ModuleRemoteSubmix.h
+++ b/audio/aidl/default/include/core-impl/ModuleRemoteSubmix.h
@@ -22,7 +22,7 @@
 
 class ModuleRemoteSubmix : public Module {
   public:
-    explicit ModuleRemoteSubmix(Module::Type type) : Module(type) {}
+    ModuleRemoteSubmix() : Module(Type::R_SUBMIX) {}
 
   private:
     // IModule interfaces
diff --git a/audio/aidl/default/include/core-impl/ModuleStub.h b/audio/aidl/default/include/core-impl/ModuleStub.h
new file mode 100644
index 0000000..59c343f
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/ModuleStub.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#pragma once
+
+#include "core-impl/Module.h"
+
+namespace aidl::android::hardware::audio::core {
+
+class ModuleStub final : public Module {
+  public:
+    ModuleStub() : Module(Type::STUB) {}
+
+  protected:
+    ndk::ScopedAStatus getBluetooth(std::shared_ptr<IBluetooth>* _aidl_return) override;
+    ndk::ScopedAStatus getBluetoothA2dp(std::shared_ptr<IBluetoothA2dp>* _aidl_return) override;
+    ndk::ScopedAStatus getBluetoothLe(std::shared_ptr<IBluetoothLe>* _aidl_return) override;
+
+    ndk::ScopedAStatus createInputStream(
+            const ::aidl::android::hardware::audio::common::SinkMetadata& sinkMetadata,
+            StreamContext&& context,
+            const std::vector<::aidl::android::media::audio::common::MicrophoneInfo>& microphones,
+            std::shared_ptr<StreamIn>* result) override;
+    ndk::ScopedAStatus createOutputStream(
+            const ::aidl::android::hardware::audio::common::SourceMetadata& sourceMetadata,
+            StreamContext&& context,
+            const std::optional<::aidl::android::media::audio::common::AudioOffloadInfo>&
+                    offloadInfo,
+            std::shared_ptr<StreamOut>* result) override;
+
+  private:
+    ChildInterface<IBluetooth> mBluetooth;
+    ChildInterface<IBluetoothA2dp> mBluetoothA2dp;
+    ChildInterface<IBluetoothLe> mBluetoothLe;
+};
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/ModuleUsb.h b/audio/aidl/default/include/core-impl/ModuleUsb.h
index 5a5429d..e6b3e66 100644
--- a/audio/aidl/default/include/core-impl/ModuleUsb.h
+++ b/audio/aidl/default/include/core-impl/ModuleUsb.h
@@ -16,13 +16,13 @@
 
 #pragma once
 
-#include "core-impl/Module.h"
+#include "core-impl/ModuleAlsa.h"
 
 namespace aidl::android::hardware::audio::core {
 
-class ModuleUsb : public Module {
+class ModuleUsb final : public ModuleAlsa {
   public:
-    explicit ModuleUsb(Module::Type type) : Module(type) {}
+    ModuleUsb() : ModuleAlsa(Type::USB) {}
 
   private:
     // IModule interfaces
diff --git a/audio/aidl/default/include/core-impl/Stream.h b/audio/aidl/default/include/core-impl/Stream.h
index aaf5860..e64c578 100644
--- a/audio/aidl/default/include/core-impl/Stream.h
+++ b/audio/aidl/default/include/core-impl/Stream.h
@@ -184,6 +184,12 @@
     virtual ::android::status_t start() = 0;
     virtual ::android::status_t transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
                                          int32_t* latencyMs) = 0;
+    // No need to implement 'getPosition' unless the driver can provide more precise
+    // data than just total frame count. For example, the driver may correctly account
+    // for any intermediate buffers.
+    virtual ::android::status_t getPosition(StreamDescriptor::Position* /*position*/) {
+        return ::android::OK;
+    }
     virtual void shutdown() = 0;  // This function is only called once.
 };
 
diff --git a/audio/aidl/default/include/core-impl/StreamAlsa.h b/audio/aidl/default/include/core-impl/StreamAlsa.h
new file mode 100644
index 0000000..5744d66
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/StreamAlsa.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#pragma once
+
+#include <optional>
+#include <vector>
+
+#include "Stream.h"
+#include "alsa/Utils.h"
+
+namespace aidl::android::hardware::audio::core {
+
+// This class is intended to be used as a base class for implementations
+// that use TinyAlsa.
+// This class does not define a complete stream implementation,
+// and should never be used on its own. Derived classes are expected to
+// provide necessary overrides for all interface methods omitted here.
+class StreamAlsa : public StreamCommonImpl {
+  public:
+    StreamAlsa(const Metadata& metadata, StreamContext&& context);
+    // Methods of 'DriverInterface'.
+    ::android::status_t init() override;
+    ::android::status_t standby() override;
+    ::android::status_t start() override;
+    ::android::status_t transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
+                                 int32_t* latencyMs) override;
+    ::android::status_t getPosition(StreamDescriptor::Position* position) override;
+    void shutdown() override;
+
+  protected:
+    // Called from 'start' to initialize 'mAlsaDeviceProxies', the vector must be non-empty.
+    virtual std::vector<alsa::DeviceProfile> getDeviceProfiles() = 0;
+
+    const size_t mFrameSizeBytes;
+    const bool mIsInput;
+    const std::optional<struct pcm_config> mConfig;
+    // All fields below are only used on the worker thread.
+    std::vector<alsa::DeviceProxy> mAlsaDeviceProxies;
+};
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/StreamRemoteSubmix.h b/audio/aidl/default/include/core-impl/StreamRemoteSubmix.h
index 2253ec7..1bca910 100644
--- a/audio/aidl/default/include/core-impl/StreamRemoteSubmix.h
+++ b/audio/aidl/default/include/core-impl/StreamRemoteSubmix.h
@@ -39,6 +39,7 @@
     ::android::status_t start() override;
     ::android::status_t transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
                                  int32_t* latencyMs) override;
+    ::android::status_t getPosition(StreamDescriptor::Position* position) override;
     void shutdown() override;
 
     // Overridden methods of 'StreamCommonImpl', called on a Binder thread.
diff --git a/audio/aidl/default/include/core-impl/StreamUsb.h b/audio/aidl/default/include/core-impl/StreamUsb.h
index 8c40782..44f742a 100644
--- a/audio/aidl/default/include/core-impl/StreamUsb.h
+++ b/audio/aidl/default/include/core-impl/StreamUsb.h
@@ -17,55 +17,34 @@
 #pragma once
 
 #include <atomic>
-#include <functional>
 #include <mutex>
-#include <optional>
 #include <vector>
 
 #include <aidl/android/media/audio/common/AudioChannelLayout.h>
 
-#include "core-impl/Stream.h"
-
-extern "C" {
-#include <tinyalsa/pcm.h>
-#include "alsa_device_proxy.h"
-}
+#include "StreamAlsa.h"
 
 namespace aidl::android::hardware::audio::core {
 
-class StreamUsb : public StreamCommonImpl {
+class StreamUsb : public StreamAlsa {
   public:
     StreamUsb(const Metadata& metadata, StreamContext&& context);
     // Methods of 'DriverInterface'.
-    ::android::status_t init() override;
     ::android::status_t drain(StreamDescriptor::DrainMode) override;
     ::android::status_t flush() override;
     ::android::status_t pause() override;
-    ::android::status_t standby() override;
-    ::android::status_t start() override;
     ::android::status_t transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
                                  int32_t* latencyMs) override;
-    void shutdown() override;
 
     // Overridden methods of 'StreamCommonImpl', called on a Binder thread.
-    const ConnectedDevices& getConnectedDevices() const override;
     ndk::ScopedAStatus setConnectedDevices(const ConnectedDevices& devices) override;
 
-  private:
-    using AlsaDeviceProxyDeleter = std::function<void(alsa_device_proxy*)>;
-    using AlsaDeviceProxy = std::unique_ptr<alsa_device_proxy, AlsaDeviceProxyDeleter>;
-
-    static std::optional<struct pcm_config> maybePopulateConfig(const StreamContext& context,
-                                                                bool isInput);
+  protected:
+    std::vector<alsa::DeviceProfile> getDeviceProfiles() override;
 
     mutable std::mutex mLock;
-
-    const size_t mFrameSizeBytes;
-    const bool mIsInput;
-    const std::optional<struct pcm_config> mConfig;
+    std::vector<alsa::DeviceProfile> mConnectedDeviceProfiles GUARDED_BY(mLock);
     std::atomic<bool> mConnectedDevicesUpdated = false;
-    // All fields below are only used on the worker thread.
-    std::vector<AlsaDeviceProxy> mAlsaDeviceProxies;
 };
 
 class StreamInUsb final : public StreamUsb, public StreamIn {
@@ -94,7 +73,7 @@
     ndk::ScopedAStatus getHwVolume(std::vector<float>* _aidl_return) override;
     ndk::ScopedAStatus setHwVolume(const std::vector<float>& in_channelVolumes) override;
 
-    int mChannelCount;
+    const int mChannelCount;
     std::vector<float> mHwVolumes;
 };
 
diff --git a/audio/aidl/default/main.cpp b/audio/aidl/default/main.cpp
index 12c0c4b..93fb366 100644
--- a/audio/aidl/default/main.cpp
+++ b/audio/aidl/default/main.cpp
@@ -16,20 +16,21 @@
 
 #include <cstdlib>
 #include <ctime>
+#include <sstream>
 #include <utility>
+#include <vector>
 
 #include <android-base/logging.h>
+#include <android-base/properties.h>
 #include <android/binder_ibinder_platform.h>
 #include <android/binder_manager.h>
 #include <android/binder_process.h>
 
 #include "core-impl/Config.h"
 #include "core-impl/Module.h"
-#include "core-impl/ModuleUsb.h"
 
 using aidl::android::hardware::audio::core::Config;
 using aidl::android::hardware::audio::core::Module;
-using aidl::android::hardware::audio::core::ModuleUsb;
 
 int main() {
     // Random values are used in the implementation.
@@ -52,18 +53,19 @@
     CHECK_EQ(STATUS_OK, status);
 
     // Make modules
-    auto createModule = [](Module::Type type, const std::string& instance) {
+    auto createModule = [](Module::Type type) {
         auto module = Module::createInstance(type);
         ndk::SpAIBinder moduleBinder = module->asBinder();
-        const std::string moduleName = std::string(Module::descriptor).append("/").append(instance);
+        std::stringstream moduleName;
+        moduleName << Module::descriptor << "/" << type;
         AIBinder_setMinSchedulerPolicy(moduleBinder.get(), SCHED_NORMAL, ANDROID_PRIORITY_AUDIO);
-        binder_status_t status = AServiceManager_addService(moduleBinder.get(), moduleName.c_str());
+        binder_status_t status =
+                AServiceManager_addService(moduleBinder.get(), moduleName.str().c_str());
         CHECK_EQ(STATUS_OK, status);
         return std::make_pair(module, moduleBinder);
     };
-    auto modules = {createModule(Module::Type::DEFAULT, "default"),
-                    createModule(Module::Type::R_SUBMIX, "r_submix"),
-                    createModule(Module::Type::USB, "usb")};
+    auto modules = {createModule(Module::Type::DEFAULT), createModule(Module::Type::R_SUBMIX),
+                    createModule(Module::Type::USB), createModule(Module::Type::STUB)};
     (void)modules;
 
     ABinderProcess_joinThreadPool();
diff --git a/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp b/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp
index 5af0d91..6d5185b 100644
--- a/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp
+++ b/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp
@@ -179,6 +179,27 @@
                      : outWrite(buffer, frameCount, actualFrameCount));
 }
 
+::android::status_t StreamRemoteSubmix::getPosition(StreamDescriptor::Position* position) {
+    sp<MonoPipeReader> source = mCurrentRoute->getSource();
+    if (source == nullptr) {
+        return ::android::NO_INIT;
+    }
+    const ssize_t framesInPipe = source->availableToRead();
+    if (framesInPipe < 0) {
+        return ::android::INVALID_OPERATION;
+    }
+    if (mIsInput) {
+        position->frames += framesInPipe;
+    } else {
+        if (position->frames > framesInPipe) {
+            position->frames -= framesInPipe;
+        } else {
+            position->frames = 0;
+        }
+    }
+    return ::android::OK;
+}
+
 // Calculate the maximum size of the pipe buffer in frames for the specified stream.
 size_t StreamRemoteSubmix::getStreamPipeSizeInFrames() {
     auto pipeConfig = mCurrentRoute->mPipeConfig;
diff --git a/audio/aidl/default/stub/ModuleStub.cpp b/audio/aidl/default/stub/ModuleStub.cpp
new file mode 100644
index 0000000..a600752
--- /dev/null
+++ b/audio/aidl/default/stub/ModuleStub.cpp
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2023 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.
+ */
+
+#include <vector>
+
+#define LOG_TAG "AHAL_ModuleStub"
+#include <Utils.h>
+#include <android-base/logging.h>
+
+#include "core-impl/Bluetooth.h"
+#include "core-impl/ModuleStub.h"
+#include "core-impl/StreamStub.h"
+
+using aidl::android::hardware::audio::common::SinkMetadata;
+using aidl::android::hardware::audio::common::SourceMetadata;
+using aidl::android::media::audio::common::AudioOffloadInfo;
+using aidl::android::media::audio::common::AudioPort;
+using aidl::android::media::audio::common::AudioPortConfig;
+using aidl::android::media::audio::common::MicrophoneInfo;
+
+namespace aidl::android::hardware::audio::core {
+
+ndk::ScopedAStatus ModuleStub::getBluetooth(std::shared_ptr<IBluetooth>* _aidl_return) {
+    if (!mBluetooth) {
+        mBluetooth = ndk::SharedRefBase::make<Bluetooth>();
+    }
+    *_aidl_return = mBluetooth.getPtr();
+    LOG(DEBUG) << __func__ << ": returning instance of IBluetooth: " << _aidl_return->get();
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ModuleStub::getBluetoothA2dp(std::shared_ptr<IBluetoothA2dp>* _aidl_return) {
+    if (!mBluetoothA2dp) {
+        mBluetoothA2dp = ndk::SharedRefBase::make<BluetoothA2dp>();
+    }
+    *_aidl_return = mBluetoothA2dp.getPtr();
+    LOG(DEBUG) << __func__ << ": returning instance of IBluetoothA2dp: " << _aidl_return->get();
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ModuleStub::getBluetoothLe(std::shared_ptr<IBluetoothLe>* _aidl_return) {
+    if (!mBluetoothLe) {
+        mBluetoothLe = ndk::SharedRefBase::make<BluetoothLe>();
+    }
+    *_aidl_return = mBluetoothLe.getPtr();
+    LOG(DEBUG) << __func__ << ": returning instance of IBluetoothLe: " << _aidl_return->get();
+    return ndk::ScopedAStatus::ok();
+}
+
+ndk::ScopedAStatus ModuleStub::createInputStream(const SinkMetadata& sinkMetadata,
+                                                 StreamContext&& context,
+                                                 const std::vector<MicrophoneInfo>& microphones,
+                                                 std::shared_ptr<StreamIn>* result) {
+    return createStreamInstance<StreamInStub>(result, sinkMetadata, std::move(context),
+                                              microphones);
+}
+
+ndk::ScopedAStatus ModuleStub::createOutputStream(
+        const SourceMetadata& sourceMetadata, StreamContext&& context,
+        const std::optional<AudioOffloadInfo>& offloadInfo, std::shared_ptr<StreamOut>* result) {
+    return createStreamInstance<StreamOutStub>(result, sourceMetadata, std::move(context),
+                                               offloadInfo);
+}
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/StreamStub.cpp b/audio/aidl/default/stub/StreamStub.cpp
similarity index 100%
rename from audio/aidl/default/StreamStub.cpp
rename to audio/aidl/default/stub/StreamStub.cpp
diff --git a/audio/aidl/default/usb/ModuleUsb.cpp b/audio/aidl/default/usb/ModuleUsb.cpp
index 5c9d477..a812e4d 100644
--- a/audio/aidl/default/usb/ModuleUsb.cpp
+++ b/audio/aidl/default/usb/ModuleUsb.cpp
@@ -14,68 +14,34 @@
  * limitations under the License.
  */
 
-#define LOG_TAG "AHAL_ModuleUsb"
-
 #include <vector>
 
+#define LOG_TAG "AHAL_ModuleUsb"
 #include <Utils.h>
 #include <android-base/logging.h>
-#include <tinyalsa/asoundlib.h>
 
 #include "UsbAlsaMixerControl.h"
-#include "UsbAlsaUtils.h"
+#include "alsa/Utils.h"
 #include "core-impl/ModuleUsb.h"
 #include "core-impl/StreamUsb.h"
 
-extern "C" {
-#include "alsa_device_profile.h"
-}
-
 using aidl::android::hardware::audio::common::SinkMetadata;
 using aidl::android::hardware::audio::common::SourceMetadata;
-using aidl::android::media::audio::common::AudioChannelLayout;
-using aidl::android::media::audio::common::AudioDeviceAddress;
 using aidl::android::media::audio::common::AudioDeviceDescription;
-using aidl::android::media::audio::common::AudioDeviceType;
-using aidl::android::media::audio::common::AudioFormatDescription;
-using aidl::android::media::audio::common::AudioFormatType;
-using aidl::android::media::audio::common::AudioIoFlags;
 using aidl::android::media::audio::common::AudioOffloadInfo;
 using aidl::android::media::audio::common::AudioPort;
 using aidl::android::media::audio::common::AudioPortConfig;
 using aidl::android::media::audio::common::AudioPortExt;
-using aidl::android::media::audio::common::AudioProfile;
 using aidl::android::media::audio::common::MicrophoneInfo;
 
 namespace aidl::android::hardware::audio::core {
 
 namespace {
 
-std::vector<AudioChannelLayout> populateChannelMasksFromProfile(const alsa_device_profile* profile,
-                                                                bool isInput) {
-    std::vector<AudioChannelLayout> channels;
-    for (size_t i = 0; i < AUDIO_PORT_MAX_CHANNEL_MASKS && profile->channel_counts[i] != 0; ++i) {
-        auto layoutMask =
-                usb::getChannelLayoutMaskFromChannelCount(profile->channel_counts[i], isInput);
-        if (layoutMask.getTag() == AudioChannelLayout::Tag::layoutMask) {
-            channels.push_back(layoutMask);
-        }
-        auto indexMask = usb::getChannelIndexMaskFromChannelCount(profile->channel_counts[i]);
-        if (indexMask.getTag() == AudioChannelLayout::Tag::indexMask) {
-            channels.push_back(indexMask);
-        }
-    }
-    return channels;
-}
-
-std::vector<int> populateSampleRatesFromProfile(const alsa_device_profile* profile) {
-    std::vector<int> sampleRates;
-    for (int i = 0; i < std::min(MAX_PROFILE_SAMPLE_RATES, AUDIO_PORT_MAX_SAMPLING_RATES) &&
-                    profile->sample_rates[i] != 0;
-         i++) {
-        sampleRates.push_back(profile->sample_rates[i]);
-    }
-    return sampleRates;
+bool isUsbDevicePort(const AudioPort& audioPort) {
+    return audioPort.ext.getTag() == AudioPortExt::Tag::device &&
+           audioPort.ext.get<AudioPortExt::Tag::device>().device.type.connection ==
+                   AudioDeviceDescription::CONNECTION_USB;
 }
 
 }  // namespace
@@ -122,55 +88,11 @@
 }
 
 ndk::ScopedAStatus ModuleUsb::populateConnectedDevicePort(AudioPort* audioPort) {
-    if (audioPort->ext.getTag() != AudioPortExt::Tag::device) {
-        LOG(ERROR) << __func__ << ": port id " << audioPort->id << " is not a device port";
-        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
-    }
-    auto& devicePort = audioPort->ext.get<AudioPortExt::Tag::device>();
-    if (devicePort.device.type.connection != AudioDeviceDescription::CONNECTION_USB) {
+    if (!isUsbDevicePort(*audioPort)) {
         LOG(ERROR) << __func__ << ": port id " << audioPort->id << " is not a usb device port";
         return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
     }
-    if (devicePort.device.address.getTag() != AudioDeviceAddress::Tag::alsa) {
-        LOG(ERROR) << __func__ << ": port id " << audioPort->id << " is not using alsa address";
-        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
-    }
-    auto& alsaAddress = devicePort.device.address.get<AudioDeviceAddress::Tag::alsa>();
-    if (alsaAddress.size() != 2 || alsaAddress[0] < 0 || alsaAddress[1] < 0) {
-        LOG(ERROR) << __func__ << ": port id " << audioPort->id << " invalid alsa address";
-        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
-    }
-
-    const bool isInput = audioPort->flags.getTag() == AudioIoFlags::input;
-    alsa_device_profile profile;
-    profile_init(&profile, isInput ? PCM_IN : PCM_OUT);
-    profile.card = alsaAddress[0];
-    profile.device = alsaAddress[1];
-    if (!profile_read_device_info(&profile)) {
-        LOG(ERROR) << __func__ << ": failed to read device info, card=" << profile.card
-                   << ", device=" << profile.device;
-        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
-    }
-
-    std::vector<AudioChannelLayout> channels = populateChannelMasksFromProfile(&profile, isInput);
-    std::vector<int> sampleRates = populateSampleRatesFromProfile(&profile);
-
-    for (size_t i = 0; i < std::min(MAX_PROFILE_FORMATS, AUDIO_PORT_MAX_AUDIO_PROFILES) &&
-                       profile.formats[i] != PCM_FORMAT_INVALID;
-         ++i) {
-        auto audioFormatDescription =
-                usb::legacy2aidl_pcm_format_AudioFormatDescription(profile.formats[i]);
-        if (audioFormatDescription.type == AudioFormatType::DEFAULT) {
-            LOG(WARNING) << __func__ << ": unknown pcm type=" << profile.formats[i];
-            continue;
-        }
-        AudioProfile audioProfile = {.format = audioFormatDescription,
-                                     .channelMasks = channels,
-                                     .sampleRates = sampleRates};
-        audioPort->profiles.push_back(std::move(audioProfile));
-    }
-
-    return ndk::ScopedAStatus::ok();
+    return ModuleAlsa::populateConnectedDevicePort(audioPort);
 }
 
 ndk::ScopedAStatus ModuleUsb::checkAudioPatchEndpointsMatch(
@@ -191,15 +113,14 @@
 
 void ModuleUsb::onExternalDeviceConnectionChanged(
         const ::aidl::android::media::audio::common::AudioPort& audioPort, bool connected) {
-    if (audioPort.ext.getTag() != AudioPortExt::Tag::device) {
+    if (!isUsbDevicePort(audioPort)) {
         return;
     }
-    const auto& address = audioPort.ext.get<AudioPortExt::Tag::device>().device.address;
-    if (address.getTag() != AudioDeviceAddress::alsa) {
+    auto profile = alsa::getDeviceProfile(audioPort);
+    if (!profile.has_value()) {
         return;
     }
-    const int card = address.get<AudioDeviceAddress::alsa>()[0];
-    usb::UsbAlsaMixerControl::getInstance().setDeviceConnectionState(card, getMasterMute(),
+    usb::UsbAlsaMixerControl::getInstance().setDeviceConnectionState(profile->card, getMasterMute(),
                                                                      getMasterVolume(), connected);
 }
 
diff --git a/audio/aidl/default/usb/StreamUsb.cpp b/audio/aidl/default/usb/StreamUsb.cpp
index 17e1ab4..da0ad11 100644
--- a/audio/aidl/default/usb/StreamUsb.cpp
+++ b/audio/aidl/default/usb/StreamUsb.cpp
@@ -23,64 +23,20 @@
 #include <error/expected_utils.h>
 
 #include "UsbAlsaMixerControl.h"
-#include "UsbAlsaUtils.h"
-#include "core-impl/Module.h"
 #include "core-impl/StreamUsb.h"
 
-extern "C" {
-#include "alsa_device_profile.h"
-}
-
 using aidl::android::hardware::audio::common::getChannelCount;
 using aidl::android::hardware::audio::common::SinkMetadata;
 using aidl::android::hardware::audio::common::SourceMetadata;
 using aidl::android::media::audio::common::AudioDevice;
-using aidl::android::media::audio::common::AudioDeviceAddress;
 using aidl::android::media::audio::common::AudioOffloadInfo;
-using aidl::android::media::audio::common::AudioPortExt;
 using aidl::android::media::audio::common::MicrophoneDynamicInfo;
 using aidl::android::media::audio::common::MicrophoneInfo;
-using android::OK;
-using android::status_t;
 
 namespace aidl::android::hardware::audio::core {
 
 StreamUsb::StreamUsb(const Metadata& metadata, StreamContext&& context)
-    : StreamCommonImpl(metadata, std::move(context)),
-      mFrameSizeBytes(getContext().getFrameSize()),
-      mIsInput(isInput(metadata)),
-      mConfig(maybePopulateConfig(getContext(), mIsInput)) {}
-
-// static
-std::optional<struct pcm_config> StreamUsb::maybePopulateConfig(const StreamContext& context,
-                                                                bool isInput) {
-    struct pcm_config config;
-    config.channels = usb::getChannelCountFromChannelMask(context.getChannelLayout(), isInput);
-    if (config.channels == 0) {
-        LOG(ERROR) << __func__ << ": invalid channel=" << context.getChannelLayout().toString();
-        return std::nullopt;
-    }
-    config.format = usb::aidl2legacy_AudioFormatDescription_pcm_format(context.getFormat());
-    if (config.format == PCM_FORMAT_INVALID) {
-        LOG(ERROR) << __func__ << ": invalid format=" << context.getFormat().toString();
-        return std::nullopt;
-    }
-    config.rate = context.getSampleRate();
-    if (config.rate == 0) {
-        LOG(ERROR) << __func__ << ": invalid sample rate=" << config.rate;
-        return std::nullopt;
-    }
-    return config;
-}
-
-::android::status_t StreamUsb::init() {
-    return mConfig.has_value() ? ::android::OK : ::android::NO_INIT;
-}
-
-const StreamCommonInterface::ConnectedDevices& StreamUsb::getConnectedDevices() const {
-    std::lock_guard guard(mLock);
-    return mConnectedDevices;
-}
+    : StreamAlsa(metadata, std::move(context)) {}
 
 ndk::ScopedAStatus StreamUsb::setConnectedDevices(
         const std::vector<AudioDevice>& connectedDevices) {
@@ -89,14 +45,19 @@
                    << ") for input stream";
         return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
     }
+    std::vector<alsa::DeviceProfile> connectedDeviceProfiles;
     for (const auto& connectedDevice : connectedDevices) {
-        if (connectedDevice.address.getTag() != AudioDeviceAddress::alsa) {
-            LOG(ERROR) << __func__ << ": bad device address" << connectedDevice.address.toString();
+        auto profile = alsa::getDeviceProfile(connectedDevice, mIsInput);
+        if (!profile.has_value()) {
+            LOG(ERROR) << __func__
+                       << ": unsupported device address=" << connectedDevice.address.toString();
             return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
         }
+        connectedDeviceProfiles.push_back(*profile);
     }
-    std::lock_guard guard(mLock);
     RETURN_STATUS_IF_ERROR(StreamCommonImpl::setConnectedDevices(connectedDevices));
+    std::lock_guard guard(mLock);
+    mConnectedDeviceProfiles = std::move(connectedDeviceProfiles);
     mConnectedDevicesUpdated.store(true, std::memory_order_release);
     return ndk::ScopedAStatus::ok();
 }
@@ -119,87 +80,22 @@
 ::android::status_t StreamUsb::transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
                                         int32_t* latencyMs) {
     if (mConnectedDevicesUpdated.load(std::memory_order_acquire)) {
-        // 'setConnectedDevices' has been called. I/O will be restarted.
+        // 'setConnectedDevices' was called. I/O will be restarted.
         *actualFrameCount = 0;
         *latencyMs = StreamDescriptor::LATENCY_UNKNOWN;
         return ::android::OK;
     }
-    const size_t bytesToTransfer = frameCount * mFrameSizeBytes;
-    unsigned maxLatency = 0;
-    if (mIsInput) {
-        if (mAlsaDeviceProxies.empty()) {
-            LOG(FATAL) << __func__ << ": no input devices";
-            return ::android::NO_INIT;
-        }
-        // For input case, only support single device.
-        proxy_read(mAlsaDeviceProxies[0].get(), buffer, bytesToTransfer);
-        maxLatency = proxy_get_latency(mAlsaDeviceProxies[0].get());
-    } else {
-        for (auto& proxy : mAlsaDeviceProxies) {
-            proxy_write(proxy.get(), buffer, bytesToTransfer);
-            maxLatency = std::max(maxLatency, proxy_get_latency(proxy.get()));
-        }
-    }
-    *actualFrameCount = frameCount;
-    maxLatency = std::min(maxLatency, static_cast<unsigned>(std::numeric_limits<int32_t>::max()));
-    *latencyMs = maxLatency;
-    return ::android::OK;
+    return StreamAlsa::transfer(buffer, frameCount, actualFrameCount, latencyMs);
 }
 
-::android::status_t StreamUsb::standby() {
-    mAlsaDeviceProxies.clear();
-    return ::android::OK;
-}
-
-void StreamUsb::shutdown() {
-    mAlsaDeviceProxies.clear();
-}
-
-::android::status_t StreamUsb::start() {
-    std::vector<AudioDeviceAddress> connectedDevices;
+std::vector<alsa::DeviceProfile> StreamUsb::getDeviceProfiles() {
+    std::vector<alsa::DeviceProfile> connectedDevices;
     {
         std::lock_guard guard(mLock);
-        std::transform(mConnectedDevices.begin(), mConnectedDevices.end(),
-                       std::back_inserter(connectedDevices),
-                       [](const auto& device) { return device.address; });
+        connectedDevices = mConnectedDeviceProfiles;
         mConnectedDevicesUpdated.store(false, std::memory_order_release);
     }
-    decltype(mAlsaDeviceProxies) alsaDeviceProxies;
-    for (const auto& device : connectedDevices) {
-        alsa_device_profile profile;
-        profile_init(&profile, mIsInput ? PCM_IN : PCM_OUT);
-        profile.card = device.get<AudioDeviceAddress::alsa>()[0];
-        profile.device = device.get<AudioDeviceAddress::alsa>()[1];
-        if (!profile_read_device_info(&profile)) {
-            LOG(ERROR) << __func__
-                       << ": unable to read device info, device address=" << device.toString();
-            return ::android::UNKNOWN_ERROR;
-        }
-
-        AlsaDeviceProxy proxy(new alsa_device_proxy, [](alsa_device_proxy* proxy) {
-            proxy_close(proxy);
-            free(proxy);
-        });
-        // Always ask for alsa configure as required since the configuration should be supported
-        // by the connected device. That is guaranteed by `setAudioPortConfig` and
-        // `setAudioPatch`.
-        if (int err = proxy_prepare(proxy.get(), &profile,
-                                    const_cast<struct pcm_config*>(&mConfig.value()),
-                                    true /*is_bit_perfect*/);
-            err != 0) {
-            LOG(ERROR) << __func__ << ": fail to prepare for device address=" << device.toString()
-                       << " error=" << err;
-            return ::android::UNKNOWN_ERROR;
-        }
-        if (int err = proxy_open(proxy.get()); err != 0) {
-            LOG(ERROR) << __func__ << ": failed to open device, address=" << device.toString()
-                       << " error=" << err;
-            return ::android::UNKNOWN_ERROR;
-        }
-        alsaDeviceProxies.push_back(std::move(proxy));
-    }
-    mAlsaDeviceProxies = std::move(alsaDeviceProxies);
-    return ::android::OK;
+    return connectedDevices;
 }
 
 StreamInUsb::StreamInUsb(const SinkMetadata& sinkMetadata, StreamContext&& context,
@@ -214,9 +110,9 @@
 
 StreamOutUsb::StreamOutUsb(const SourceMetadata& sourceMetadata, StreamContext&& context,
                            const std::optional<AudioOffloadInfo>& offloadInfo)
-    : StreamUsb(sourceMetadata, std::move(context)), StreamOut(offloadInfo) {
-    mChannelCount = getChannelCount(getContext().getChannelLayout());
-}
+    : StreamUsb(sourceMetadata, std::move(context)),
+      StreamOut(offloadInfo),
+      mChannelCount(getChannelCount(getContext().getChannelLayout())) {}
 
 ndk::ScopedAStatus StreamOutUsb::getHwVolume(std::vector<float>* _aidl_return) {
     *_aidl_return = mHwVolumes;
@@ -224,17 +120,17 @@
 }
 
 ndk::ScopedAStatus StreamOutUsb::setHwVolume(const std::vector<float>& in_channelVolumes) {
+    // Avoid using mConnectedDeviceProfiles because it requires a lock.
     for (const auto& device : getConnectedDevices()) {
-        if (device.address.getTag() != AudioDeviceAddress::alsa) {
-            LOG(DEBUG) << __func__ << ": skip as the device address is not alsa";
-            continue;
-        }
-        const int card = device.address.get<AudioDeviceAddress::alsa>()[0];
-        if (auto result =
-                    usb::UsbAlsaMixerControl::getInstance().setVolumes(card, in_channelVolumes);
-            !result.isOk()) {
-            LOG(ERROR) << __func__ << ": failed to set volume for device, card=" << card;
-            return result;
+        if (auto deviceProfile = alsa::getDeviceProfile(device, mIsInput);
+            deviceProfile.has_value()) {
+            if (auto result = usb::UsbAlsaMixerControl::getInstance().setVolumes(
+                        deviceProfile->card, in_channelVolumes);
+                !result.isOk()) {
+                LOG(ERROR) << __func__
+                           << ": failed to set volume for device address=" << *deviceProfile;
+                return result;
+            }
         }
     }
     mHwVolumes = in_channelVolumes;
diff --git a/audio/aidl/default/usb/UsbAlsaMixerControl.cpp b/audio/aidl/default/usb/UsbAlsaMixerControl.cpp
index 6c0c24b..769d739 100644
--- a/audio/aidl/default/usb/UsbAlsaMixerControl.cpp
+++ b/audio/aidl/default/usb/UsbAlsaMixerControl.cpp
@@ -17,144 +17,12 @@
 #define LOG_TAG "AHAL_UsbAlsaMixerControl"
 #include <android-base/logging.h>
 
-#include <cmath>
-#include <string>
-#include <vector>
-
 #include <android/binder_status.h>
 
 #include "UsbAlsaMixerControl.h"
 
 namespace aidl::android::hardware::audio::core::usb {
 
-//-----------------------------------------------------------------------------
-
-MixerControl::MixerControl(struct mixer_ctl* ctl)
-    : mCtl(ctl),
-      mNumValues(mixer_ctl_get_num_values(ctl)),
-      mMinValue(mixer_ctl_get_range_min(ctl)),
-      mMaxValue(mixer_ctl_get_range_max(ctl)) {}
-
-unsigned int MixerControl::getNumValues() const {
-    return mNumValues;
-}
-
-int MixerControl::getMaxValue() const {
-    return mMaxValue;
-}
-
-int MixerControl::getMinValue() const {
-    return mMinValue;
-}
-
-int MixerControl::setArray(const void* array, size_t count) {
-    const std::lock_guard guard(mLock);
-    return mixer_ctl_set_array(mCtl, array, count);
-}
-
-//-----------------------------------------------------------------------------
-
-// static
-const std::map<AlsaMixer::Control, std::vector<AlsaMixer::ControlNamesAndExpectedCtlType>>
-        AlsaMixer::kPossibleControls = {
-                {AlsaMixer::MASTER_SWITCH, {{"Master Playback Switch", MIXER_CTL_TYPE_BOOL}}},
-                {AlsaMixer::MASTER_VOLUME, {{"Master Playback Volume", MIXER_CTL_TYPE_INT}}},
-                {AlsaMixer::HW_VOLUME,
-                 {{"Headphone Playback Volume", MIXER_CTL_TYPE_INT},
-                  {"Headset Playback Volume", MIXER_CTL_TYPE_INT},
-                  {"PCM Playback Volume", MIXER_CTL_TYPE_INT}}}};
-
-// static
-std::map<AlsaMixer::Control, std::shared_ptr<MixerControl>> AlsaMixer::initializeMixerControls(
-        struct mixer* mixer) {
-    std::map<AlsaMixer::Control, std::shared_ptr<MixerControl>> mixerControls;
-    std::string mixerCtlNames;
-    for (const auto& [control, possibleCtls] : kPossibleControls) {
-        for (const auto& [ctlName, expectedCtlType] : possibleCtls) {
-            struct mixer_ctl* ctl = mixer_get_ctl_by_name(mixer, ctlName.c_str());
-            if (ctl != nullptr && mixer_ctl_get_type(ctl) == expectedCtlType) {
-                mixerControls.emplace(control, std::make_unique<MixerControl>(ctl));
-                if (!mixerCtlNames.empty()) {
-                    mixerCtlNames += ",";
-                }
-                mixerCtlNames += ctlName;
-                break;
-            }
-        }
-    }
-    LOG(DEBUG) << __func__ << ": available mixer control names=[" << mixerCtlNames << "]";
-    return mixerControls;
-}
-
-AlsaMixer::AlsaMixer(struct mixer* mixer)
-    : mMixer(mixer), mMixerControls(initializeMixerControls(mMixer)) {}
-
-AlsaMixer::~AlsaMixer() {
-    mixer_close(mMixer);
-}
-
-namespace {
-
-int volumeFloatToInteger(float fValue, int maxValue, int minValue) {
-    return minValue + std::ceil((maxValue - minValue) * fValue);
-}
-
-}  // namespace
-
-ndk::ScopedAStatus AlsaMixer::setMasterMute(bool muted) {
-    auto it = mMixerControls.find(AlsaMixer::MASTER_SWITCH);
-    if (it == mMixerControls.end()) {
-        return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
-    }
-    const int numValues = it->second->getNumValues();
-    std::vector<int> values(numValues, muted ? 0 : 1);
-    if (int err = it->second->setArray(values.data(), numValues); err != 0) {
-        LOG(ERROR) << __func__ << ": failed to set master mute, err=" << err;
-        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
-    }
-    return ndk::ScopedAStatus::ok();
-}
-
-ndk::ScopedAStatus AlsaMixer::setMasterVolume(float volume) {
-    auto it = mMixerControls.find(AlsaMixer::MASTER_VOLUME);
-    if (it == mMixerControls.end()) {
-        return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
-    }
-    const int numValues = it->second->getNumValues();
-    std::vector<int> values(numValues, volumeFloatToInteger(volume, it->second->getMaxValue(),
-                                                            it->second->getMinValue()));
-    if (int err = it->second->setArray(values.data(), numValues); err != 0) {
-        LOG(ERROR) << __func__ << ": failed to set master volume, err=" << err;
-        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
-    }
-    return ndk::ScopedAStatus::ok();
-}
-
-ndk::ScopedAStatus AlsaMixer::setVolumes(std::vector<float> volumes) {
-    auto it = mMixerControls.find(AlsaMixer::HW_VOLUME);
-    if (it == mMixerControls.end()) {
-        return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
-    }
-    const int numValues = it->second->getNumValues();
-    if (numValues < 0) {
-        LOG(FATAL) << __func__ << ": negative number of values: " << numValues;
-    }
-    const int maxValue = it->second->getMaxValue();
-    const int minValue = it->second->getMinValue();
-    std::vector<int> values;
-    size_t i = 0;
-    for (; i < static_cast<size_t>(numValues) && i < values.size(); ++i) {
-        values.emplace_back(volumeFloatToInteger(volumes[i], maxValue, minValue));
-    }
-    if (int err = it->second->setArray(values.data(), values.size()); err != 0) {
-        LOG(ERROR) << __func__ << ": failed to set volume, err=" << err;
-        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_STATE);
-    }
-    return ndk::ScopedAStatus::ok();
-}
-
-//-----------------------------------------------------------------------------
-
 // static
 UsbAlsaMixerControl& UsbAlsaMixerControl::getInstance() {
     static UsbAlsaMixerControl gInstance;
@@ -170,7 +38,7 @@
             PLOG(ERROR) << __func__ << ": failed to open mixer for card=" << card;
             return;
         }
-        auto alsaMixer = std::make_shared<AlsaMixer>(mixer);
+        auto alsaMixer = std::make_shared<alsa::Mixer>(mixer);
         alsaMixer->setMasterMute(masterMuted);
         alsaMixer->setMasterVolume(masterVolume);
         const std::lock_guard guard(mLock);
@@ -209,7 +77,7 @@
     return ndk::ScopedAStatus::ok();
 }
 
-ndk::ScopedAStatus UsbAlsaMixerControl::setVolumes(int card, std::vector<float> volumes) {
+ndk::ScopedAStatus UsbAlsaMixerControl::setVolumes(int card, const std::vector<float>& volumes) {
     auto alsaMixer = getAlsaMixer(card);
     if (alsaMixer == nullptr) {
         LOG(ERROR) << __func__ << ": no mixer control found for card=" << card;
@@ -218,13 +86,13 @@
     return alsaMixer->setVolumes(volumes);
 }
 
-std::shared_ptr<AlsaMixer> UsbAlsaMixerControl::getAlsaMixer(int card) {
+std::shared_ptr<alsa::Mixer> UsbAlsaMixerControl::getAlsaMixer(int card) {
     const std::lock_guard guard(mLock);
     const auto it = mMixerControls.find(card);
     return it == mMixerControls.end() ? nullptr : it->second;
 }
 
-std::map<int, std::shared_ptr<AlsaMixer>> UsbAlsaMixerControl::getAlsaMixers() {
+std::map<int, std::shared_ptr<alsa::Mixer>> UsbAlsaMixerControl::getAlsaMixers() {
     const std::lock_guard guard(mLock);
     return mMixerControls;
 }
diff --git a/audio/aidl/default/usb/UsbAlsaMixerControl.h b/audio/aidl/default/usb/UsbAlsaMixerControl.h
index cbcddd8..c3265f8 100644
--- a/audio/aidl/default/usb/UsbAlsaMixerControl.h
+++ b/audio/aidl/default/usb/UsbAlsaMixerControl.h
@@ -19,67 +19,15 @@
 #include <map>
 #include <memory>
 #include <mutex>
-#include <optional>
-#include <string>
 #include <vector>
 
 #include <android-base/thread_annotations.h>
 #include <android/binder_auto_utils.h>
 
-extern "C" {
-#include <tinyalsa/mixer.h>
-}
+#include "alsa/Mixer.h"
 
 namespace aidl::android::hardware::audio::core::usb {
 
-class MixerControl {
-  public:
-    explicit MixerControl(struct mixer_ctl* ctl);
-
-    unsigned int getNumValues() const;
-    int getMaxValue() const;
-    int getMinValue() const;
-    int setArray(const void* array, size_t count);
-
-  private:
-    std::mutex mLock;
-    // The mixer_ctl object is owned by ALSA and will be released when the mixer is closed.
-    struct mixer_ctl* mCtl GUARDED_BY(mLock);
-    const unsigned int mNumValues;
-    const int mMinValue;
-    const int mMaxValue;
-};
-
-class AlsaMixer {
-  public:
-    explicit AlsaMixer(struct mixer* mixer);
-
-    ~AlsaMixer();
-
-    bool isValid() const { return mMixer != nullptr; }
-
-    ndk::ScopedAStatus setMasterMute(bool muted);
-    ndk::ScopedAStatus setMasterVolume(float volume);
-    ndk::ScopedAStatus setVolumes(std::vector<float> volumes);
-
-  private:
-    enum Control {
-        MASTER_SWITCH,
-        MASTER_VOLUME,
-        HW_VOLUME,
-    };
-    using ControlNamesAndExpectedCtlType = std::pair<std::string, enum mixer_ctl_type>;
-    static const std::map<Control, std::vector<ControlNamesAndExpectedCtlType>> kPossibleControls;
-    static std::map<Control, std::shared_ptr<MixerControl>> initializeMixerControls(
-            struct mixer* mixer);
-
-    // The mixer object is owned by ALSA and will be released when the mixer is closed.
-    struct mixer* mMixer;
-    // `mMixerControls` will only be initialized in constructor. After that, it wil only be
-    // read but not be modified.
-    const std::map<Control, std::shared_ptr<MixerControl>> mMixerControls;
-};
-
 class UsbAlsaMixerControl {
   public:
     static UsbAlsaMixerControl& getInstance();
@@ -91,16 +39,16 @@
     ndk::ScopedAStatus setMasterMute(bool muted);
     ndk::ScopedAStatus setMasterVolume(float volume);
     // The volume settings can be different on sound cards. It is controlled by streams.
-    ndk::ScopedAStatus setVolumes(int card, std::vector<float> volumes);
+    ndk::ScopedAStatus setVolumes(int card, const std::vector<float>& volumes);
 
   private:
-    std::shared_ptr<AlsaMixer> getAlsaMixer(int card);
-    std::map<int, std::shared_ptr<AlsaMixer>> getAlsaMixers();
+    std::shared_ptr<alsa::Mixer> getAlsaMixer(int card);
+    std::map<int, std::shared_ptr<alsa::Mixer>> getAlsaMixers();
 
     std::mutex mLock;
     // A map whose key is the card number and value is a shared pointer to corresponding
     // AlsaMixer object.
-    std::map<int, std::shared_ptr<AlsaMixer>> mMixerControls GUARDED_BY(mLock);
+    std::map<int, std::shared_ptr<alsa::Mixer>> mMixerControls GUARDED_BY(mLock);
 };
 
 }  // namespace aidl::android::hardware::audio::core::usb
diff --git a/audio/aidl/default/usb/UsbAlsaUtils.cpp b/audio/aidl/default/usb/UsbAlsaUtils.cpp
deleted file mode 100644
index 74d9c28..0000000
--- a/audio/aidl/default/usb/UsbAlsaUtils.cpp
+++ /dev/null
@@ -1,181 +0,0 @@
-/*
- * Copyright (C) 2023 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.
- */
-
-#include <map>
-#include <set>
-
-#include <Utils.h>
-#include <aidl/android/media/audio/common/AudioFormatType.h>
-#include <aidl/android/media/audio/common/PcmType.h>
-
-#include "UsbAlsaUtils.h"
-#include "core-impl/utils.h"
-
-using aidl::android::hardware::audio::common::getChannelCount;
-using aidl::android::media::audio::common::AudioChannelLayout;
-using aidl::android::media::audio::common::AudioFormatDescription;
-using aidl::android::media::audio::common::AudioFormatType;
-using aidl::android::media::audio::common::PcmType;
-
-namespace aidl::android::hardware::audio::core::usb {
-
-namespace {
-
-using AudioChannelCountToMaskMap = std::map<unsigned int, AudioChannelLayout>;
-using AudioFormatDescToPcmFormatMap = std::map<AudioFormatDescription, enum pcm_format>;
-using PcmFormatToAudioFormatDescMap = std::map<enum pcm_format, AudioFormatDescription>;
-
-static const AudioChannelLayout INVALID_CHANNEL_LAYOUT =
-        AudioChannelLayout::make<AudioChannelLayout::Tag::invalid>(0);
-
-#define DEFINE_CHANNEL_LAYOUT_MASK(n) \
-    AudioChannelLayout::make<AudioChannelLayout::Tag::layoutMask>(AudioChannelLayout::LAYOUT_##n)
-
-static const std::set<AudioChannelLayout> SUPPORTED_OUT_CHANNEL_LAYOUTS = {
-        DEFINE_CHANNEL_LAYOUT_MASK(MONO),          DEFINE_CHANNEL_LAYOUT_MASK(STEREO),
-        DEFINE_CHANNEL_LAYOUT_MASK(2POINT1),       DEFINE_CHANNEL_LAYOUT_MASK(QUAD),
-        DEFINE_CHANNEL_LAYOUT_MASK(PENTA),         DEFINE_CHANNEL_LAYOUT_MASK(5POINT1),
-        DEFINE_CHANNEL_LAYOUT_MASK(6POINT1),       DEFINE_CHANNEL_LAYOUT_MASK(7POINT1),
-        DEFINE_CHANNEL_LAYOUT_MASK(7POINT1POINT4), DEFINE_CHANNEL_LAYOUT_MASK(22POINT2),
-};
-
-static const std::set<AudioChannelLayout> SUPPORTED_IN_CHANNEL_LAYOUTS = {
-        DEFINE_CHANNEL_LAYOUT_MASK(MONO),
-        DEFINE_CHANNEL_LAYOUT_MASK(STEREO),
-};
-
-#define DEFINE_CHANNEL_INDEX_MASK(n) \
-    AudioChannelLayout::make<AudioChannelLayout::Tag::indexMask>(AudioChannelLayout::INDEX_MASK_##n)
-
-static const std::set<AudioChannelLayout> SUPPORTED_INDEX_CHANNEL_LAYOUTS = {
-        DEFINE_CHANNEL_INDEX_MASK(1),  DEFINE_CHANNEL_INDEX_MASK(2),  DEFINE_CHANNEL_INDEX_MASK(3),
-        DEFINE_CHANNEL_INDEX_MASK(4),  DEFINE_CHANNEL_INDEX_MASK(5),  DEFINE_CHANNEL_INDEX_MASK(6),
-        DEFINE_CHANNEL_INDEX_MASK(7),  DEFINE_CHANNEL_INDEX_MASK(8),  DEFINE_CHANNEL_INDEX_MASK(9),
-        DEFINE_CHANNEL_INDEX_MASK(10), DEFINE_CHANNEL_INDEX_MASK(11), DEFINE_CHANNEL_INDEX_MASK(12),
-        DEFINE_CHANNEL_INDEX_MASK(13), DEFINE_CHANNEL_INDEX_MASK(14), DEFINE_CHANNEL_INDEX_MASK(15),
-        DEFINE_CHANNEL_INDEX_MASK(16), DEFINE_CHANNEL_INDEX_MASK(17), DEFINE_CHANNEL_INDEX_MASK(18),
-        DEFINE_CHANNEL_INDEX_MASK(19), DEFINE_CHANNEL_INDEX_MASK(20), DEFINE_CHANNEL_INDEX_MASK(21),
-        DEFINE_CHANNEL_INDEX_MASK(22), DEFINE_CHANNEL_INDEX_MASK(23), DEFINE_CHANNEL_INDEX_MASK(24),
-};
-
-static AudioChannelCountToMaskMap make_ChannelCountToMaskMap(
-        const std::set<AudioChannelLayout>& channelMasks) {
-    AudioChannelCountToMaskMap channelMaskToCountMap;
-    for (const auto& channelMask : channelMasks) {
-        channelMaskToCountMap.emplace(getChannelCount(channelMask), channelMask);
-    }
-    return channelMaskToCountMap;
-}
-
-const AudioChannelCountToMaskMap& getSupportedChannelOutLayoutMap() {
-    static const AudioChannelCountToMaskMap outLayouts =
-            make_ChannelCountToMaskMap(SUPPORTED_OUT_CHANNEL_LAYOUTS);
-    return outLayouts;
-}
-
-const AudioChannelCountToMaskMap& getSupportedChannelInLayoutMap() {
-    static const AudioChannelCountToMaskMap inLayouts =
-            make_ChannelCountToMaskMap(SUPPORTED_IN_CHANNEL_LAYOUTS);
-    return inLayouts;
-}
-
-const AudioChannelCountToMaskMap& getSupportedChannelIndexLayoutMap() {
-    static const AudioChannelCountToMaskMap indexLayouts =
-            make_ChannelCountToMaskMap(SUPPORTED_INDEX_CHANNEL_LAYOUTS);
-    return indexLayouts;
-}
-
-AudioFormatDescription make_AudioFormatDescription(AudioFormatType type) {
-    AudioFormatDescription result;
-    result.type = type;
-    return result;
-}
-
-AudioFormatDescription make_AudioFormatDescription(PcmType pcm) {
-    auto result = make_AudioFormatDescription(AudioFormatType::PCM);
-    result.pcm = pcm;
-    return result;
-}
-
-const AudioFormatDescToPcmFormatMap& getAudioFormatDescriptorToPcmFormatMap() {
-    static const AudioFormatDescToPcmFormatMap formatDescToPcmFormatMap = {
-            {make_AudioFormatDescription(PcmType::UINT_8_BIT), PCM_FORMAT_S8},
-            {make_AudioFormatDescription(PcmType::INT_16_BIT), PCM_FORMAT_S16_LE},
-            {make_AudioFormatDescription(PcmType::FIXED_Q_8_24), PCM_FORMAT_S24_LE},
-            {make_AudioFormatDescription(PcmType::INT_24_BIT), PCM_FORMAT_S24_3LE},
-            {make_AudioFormatDescription(PcmType::INT_32_BIT), PCM_FORMAT_S32_LE},
-            {make_AudioFormatDescription(PcmType::FLOAT_32_BIT), PCM_FORMAT_FLOAT_LE},
-    };
-    return formatDescToPcmFormatMap;
-}
-
-static PcmFormatToAudioFormatDescMap make_PcmFormatToAudioFormatDescMap(
-        const AudioFormatDescToPcmFormatMap& formatDescToPcmFormatMap) {
-    PcmFormatToAudioFormatDescMap result;
-    for (const auto& formatPair : formatDescToPcmFormatMap) {
-        result.emplace(formatPair.second, formatPair.first);
-    }
-    return result;
-}
-
-const PcmFormatToAudioFormatDescMap& getPcmFormatToAudioFormatDescMap() {
-    static const PcmFormatToAudioFormatDescMap pcmFormatToFormatDescMap =
-            make_PcmFormatToAudioFormatDescMap(getAudioFormatDescriptorToPcmFormatMap());
-    return pcmFormatToFormatDescMap;
-}
-
-}  // namespace
-
-AudioChannelLayout getChannelLayoutMaskFromChannelCount(unsigned int channelCount, int isInput) {
-    return findValueOrDefault(
-            isInput ? getSupportedChannelInLayoutMap() : getSupportedChannelOutLayoutMap(),
-            channelCount, INVALID_CHANNEL_LAYOUT);
-}
-
-AudioChannelLayout getChannelIndexMaskFromChannelCount(unsigned int channelCount) {
-    return findValueOrDefault(getSupportedChannelIndexLayoutMap(), channelCount,
-                              INVALID_CHANNEL_LAYOUT);
-}
-
-unsigned int getChannelCountFromChannelMask(const AudioChannelLayout& channelMask, bool isInput) {
-    switch (channelMask.getTag()) {
-        case AudioChannelLayout::Tag::layoutMask: {
-            return findKeyOrDefault(
-                    isInput ? getSupportedChannelInLayoutMap() : getSupportedChannelOutLayoutMap(),
-                    (unsigned int)getChannelCount(channelMask), 0u /*defaultValue*/);
-        }
-        case AudioChannelLayout::Tag::indexMask: {
-            return findKeyOrDefault(getSupportedChannelIndexLayoutMap(),
-                                    (unsigned int)getChannelCount(channelMask),
-                                    0u /*defaultValue*/);
-        }
-        case AudioChannelLayout::Tag::none:
-        case AudioChannelLayout::Tag::invalid:
-        case AudioChannelLayout::Tag::voiceMask:
-        default:
-            return 0;
-    }
-}
-
-AudioFormatDescription legacy2aidl_pcm_format_AudioFormatDescription(enum pcm_format legacy) {
-    return findValueOrDefault(getPcmFormatToAudioFormatDescMap(), legacy, AudioFormatDescription());
-}
-
-pcm_format aidl2legacy_AudioFormatDescription_pcm_format(const AudioFormatDescription& aidl) {
-    return findValueOrDefault(getAudioFormatDescriptorToPcmFormatMap(), aidl, PCM_FORMAT_INVALID);
-}
-
-}  // namespace aidl::android::hardware::audio::core::usb
diff --git a/audio/aidl/default/usb/UsbAlsaUtils.h b/audio/aidl/default/usb/UsbAlsaUtils.h
deleted file mode 100644
index 2d2f0f4..0000000
--- a/audio/aidl/default/usb/UsbAlsaUtils.h
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Copyright (C) 2023 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.
- */
-
-#pragma once
-
-#include <aidl/android/media/audio/common/AudioChannelLayout.h>
-#include <aidl/android/media/audio/common/AudioFormatDescription.h>
-
-extern "C" {
-#include <tinyalsa/pcm.h>
-}
-
-namespace aidl::android::hardware::audio::core::usb {
-
-::aidl::android::media::audio::common::AudioChannelLayout getChannelLayoutMaskFromChannelCount(
-        unsigned int channelCount, int isInput);
-::aidl::android::media::audio::common::AudioChannelLayout getChannelIndexMaskFromChannelCount(
-        unsigned int channelCount);
-unsigned int getChannelCountFromChannelMask(
-        const ::aidl::android::media::audio::common::AudioChannelLayout& channelMask, bool isInput);
-::aidl::android::media::audio::common::AudioFormatDescription
-legacy2aidl_pcm_format_AudioFormatDescription(enum pcm_format legacy);
-pcm_format aidl2legacy_AudioFormatDescription_pcm_format(
-        const ::aidl::android::media::audio::common::AudioFormatDescription& aidl);
-
-}  // namespace aidl::android::hardware::audio::core::usb
\ No newline at end of file