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..ecb3c78
--- /dev/null
+++ b/audio/aidl/default/alsa/StreamAlsa.cpp
@@ -0,0 +1,103 @@
+/*
+ * 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 <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;
+}
+
+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