diff --git a/services/soundtrigger/Android.mk b/services/soundtrigger/Android.mk
index c55ac7f..f719dc9 100644
--- a/services/soundtrigger/Android.mk
+++ b/services/soundtrigger/Android.mk
@@ -16,7 +16,6 @@
 
 include $(CLEAR_VARS)
 
-
 ifeq ($(SOUND_TRIGGER_USE_STUB_MODULE), 1)
     LOCAL_CFLAGS += -DSOUND_TRIGGER_USE_STUB_MODULE
 endif
@@ -35,12 +34,32 @@
     libmedia \
     libserviceutility
 
+
+ifeq ($(ENABLE_TREBLE),true)
+# Treble configuration
+LOCAL_CFLAGS += -DENABLE_TREBLE
+LOCAL_SRC_FILES +=               \
+    SoundTriggerHalHidl.cpp
+
+LOCAL_SHARED_LIBRARIES += \
+		libhwbinder \
+		libhidl \
+		libbase \
+		android.hardware.soundtrigger@2.0 \
+		android.hardware.audio.common@2.0
+else
+# libhardware configuration
+LOCAL_SRC_FILES +=               \
+    SoundTriggerHalLegacy.cpp
+endif
+
+
 LOCAL_C_INCLUDES += \
     $(TOPDIR)frameworks/av/services/audioflinger
 
 LOCAL_MULTILIB := $(AUDIOSERVER_MULTILIB)
 
-LOCAL_CFLAGS := -Wall -Werror
+LOCAL_CFLAGS += -Wall -Werror
 
 LOCAL_MODULE:= libsoundtriggerservice
 
diff --git a/services/soundtrigger/SoundTriggerHalHidl.cpp b/services/soundtrigger/SoundTriggerHalHidl.cpp
new file mode 100644
index 0000000..6fe719e
--- /dev/null
+++ b/services/soundtrigger/SoundTriggerHalHidl.cpp
@@ -0,0 +1,628 @@
+/*
+ * Copyright (C) 2016 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 "SoundTriggerHalHidl"
+//#define LOG_NDEBUG 0
+
+#include <utils/Log.h>
+#include "SoundTriggerHalHidl.h"
+#include <hidl/IServiceManager.h>
+#include <hwbinder/IPCThreadState.h>
+#include <hwbinder/ProcessState.h>
+
+namespace android {
+
+using android::hardware::Return;
+using android::hardware::ProcessState;
+using android::hardware::audio::common::V2_0::AudioDevice;
+
+pthread_once_t SoundTriggerHalHidl::sOnceControl = PTHREAD_ONCE_INIT;
+
+void SoundTriggerHalHidl::sOnceInit()
+{
+    ProcessState::self()->setThreadPoolMaxThreadCount(1);
+    ProcessState::self()->startThreadPool();
+}
+
+/* static */
+sp<SoundTriggerHalInterface> SoundTriggerHalInterface::connectModule(const char *moduleName)
+{
+    return new SoundTriggerHalHidl(moduleName);
+}
+
+int SoundTriggerHalHidl::getProperties(struct sound_trigger_properties *properties)
+{
+    sp<ISoundTriggerHw> soundtrigger = getService();
+    if (soundtrigger == 0) {
+        return -ENODEV;
+    }
+
+    ISoundTriggerHw::Properties halProperties;
+    Return<void> hidlReturn;
+    int32_t halReturn;
+    {
+        AutoMutex lock(mHalLock);
+        hidlReturn = soundtrigger->getProperties([&](int rc, auto res) {
+            halReturn = rc;
+            halProperties = res;
+            ALOGI("getProperties res implementor %s", res.implementor.c_str());
+        });
+    }
+
+    int ret = 0;
+    if (hidlReturn.getStatus().isOk()) {
+        convertPropertiesFromHal(properties, &halProperties);
+    } else {
+        ret = (int)hidlReturn.getStatus().transactionError();
+        if (ret == -EPIPE) {
+            clearService();
+        }
+    }
+
+    return ret;
+}
+
+int SoundTriggerHalHidl::loadSoundModel(struct sound_trigger_sound_model *sound_model,
+                        sound_model_callback_t callback,
+                        void *cookie,
+                        sound_model_handle_t *handle)
+{
+    if (handle == NULL) {
+        return -EINVAL;
+    }
+
+    sp<ISoundTriggerHw> soundtrigger = getService();
+    if (soundtrigger == 0) {
+        return -ENODEV;
+    }
+
+    uint32_t modelId;
+    {
+        AutoMutex lock(mLock);
+        do {
+            modelId = nextUniqueId();
+            ALOGI("loadSoundModel modelId %u", modelId);
+            sp<SoundModel> model = mSoundModels.valueFor(modelId);
+            ALOGI("loadSoundModel model %p", model.get());
+        } while (mSoundModels.valueFor(modelId) != 0 && modelId != 0);
+    }
+    LOG_ALWAYS_FATAL_IF(modelId == 0,
+                        "loadSoundModel(): wrap around in sound model IDs, num loaded models %zd",
+                        mSoundModels.size());
+
+    ISoundTriggerHw::SoundModel *halSoundModel =
+            convertSoundModelToHal(sound_model);
+    if (halSoundModel == NULL) {
+        return -EINVAL;
+    }
+
+    Return<void> hidlReturn;
+    int32_t halReturn;
+    SoundModelHandle halHandle;
+    {
+        AutoMutex lock(mHalLock);
+        if (sound_model->type == SOUND_MODEL_TYPE_KEYPHRASE) {
+            hidlReturn = soundtrigger->loadPhraseSoundModel(
+                    *(const ISoundTriggerHw::PhraseSoundModel *)halSoundModel,
+                    this, modelId, [&](int32_t retval, auto res) {
+                halReturn = retval;
+                halHandle = res;
+            });
+
+        } else {
+            hidlReturn = soundtrigger->loadSoundModel(*halSoundModel,
+                    this, modelId, [&](int32_t retval, auto res) {
+                halReturn = retval;
+                halHandle = res;
+            });
+        }
+    }
+
+    delete halSoundModel;
+
+    int ret = 0;
+    if (hidlReturn.getStatus().isOk()) {
+        AutoMutex lock(mLock);
+        *handle = (sound_model_handle_t)modelId;
+        sp<SoundModel> model = new SoundModel(*handle, callback, cookie, halHandle);
+        mSoundModels.add(*handle, model);
+    } else {
+        ret = (int)hidlReturn.getStatus().transactionError();
+        ALOGE("loadSoundModel error %d", ret);
+        if (ret == -EPIPE) {
+            clearService();
+        }
+    }
+
+
+    return ret;
+}
+
+int SoundTriggerHalHidl::unloadSoundModel(sound_model_handle_t handle)
+{
+    sp<ISoundTriggerHw> soundtrigger = getService();
+    if (soundtrigger == 0) {
+        return -ENODEV;
+    }
+
+    sp<SoundModel> model = removeModel(handle);
+    if (model == 0) {
+        ALOGE("unloadSoundModel model not found for handle %u", handle);
+        return -EINVAL;
+    }
+
+    Return<int32_t> halReturn(0);
+    {
+        AutoMutex lock(mHalLock);
+        halReturn = soundtrigger->unloadSoundModel(model->mHalHandle);
+    }
+
+    int ret = (int)halReturn.getStatus().transactionError();
+    ALOGE_IF(ret != 0, "unloadSoundModel error %d", ret);
+    if (ret == -EPIPE) {
+        clearService();
+    }
+
+    return ret;
+}
+
+int SoundTriggerHalHidl::startRecognition(sound_model_handle_t handle,
+                         const struct sound_trigger_recognition_config *config,
+                         recognition_callback_t callback,
+                         void *cookie)
+{
+    sp<ISoundTriggerHw> soundtrigger = getService();
+    if (soundtrigger == 0) {
+        return -ENODEV;
+    }
+
+    sp<SoundModel> model = getModel(handle);
+    if (model == 0) {
+        ALOGE("startRecognition model not found for handle %u", handle);
+        return -EINVAL;
+    }
+
+    model->mRecognitionCallback = callback;
+    model->mRecognitionCookie = cookie;
+
+    ISoundTriggerHw::RecognitionConfig *halConfig =
+            convertRecognitionConfigToHal(config);
+
+    Return<int32_t> halReturn(0);
+    {
+        AutoMutex lock(mHalLock);
+        halReturn = soundtrigger->startRecognition(model->mHalHandle, *halConfig, this, handle);
+    }
+
+    delete halConfig;
+
+    int ret = (int)halReturn.getStatus().transactionError();
+    ALOGE_IF(ret != 0, "startRecognition error %d", ret);
+    if (ret == -EPIPE) {
+        clearService();
+    }
+    return ret;
+}
+
+int SoundTriggerHalHidl::stopRecognition(sound_model_handle_t handle)
+{
+    sp<ISoundTriggerHw> soundtrigger = getService();
+    if (soundtrigger == 0) {
+        return -ENODEV;
+    }
+
+    sp<SoundModel> model = getModel(handle);
+    if (model == 0) {
+        ALOGE("stopRecognition model not found for handle %u", handle);
+        return -EINVAL;
+    }
+
+    Return<int32_t> halReturn(0);
+    {
+        AutoMutex lock(mHalLock);
+        halReturn = soundtrigger->stopRecognition(model->mHalHandle);
+    }
+
+    int ret = (int)halReturn.getStatus().transactionError();
+    ALOGE_IF(ret != 0, "stopRecognition error %d", ret);
+    if (ret == -EPIPE) {
+        clearService();
+    }
+    return ret;
+}
+
+int SoundTriggerHalHidl::stopAllRecognitions()
+{
+    sp<ISoundTriggerHw> soundtrigger = getService();
+    if (soundtrigger == 0) {
+        return -ENODEV;
+    }
+
+    Return<int32_t> halReturn(0);
+    {
+        AutoMutex lock(mHalLock);
+        Return<int32_t> halReturn = soundtrigger->stopAllRecognitions();
+    }
+
+    int ret = (int)halReturn.getStatus().transactionError();
+    ALOGE_IF(ret != 0, "stopAllRecognitions error %d", ret);
+    if (ret == -EPIPE) {
+        clearService();
+    }
+    return ret;
+}
+
+SoundTriggerHalHidl::SoundTriggerHalHidl(const char *moduleName)
+    : mModuleName(moduleName), mNextUniqueId(1)
+{
+}
+
+void SoundTriggerHalHidl::onFirstRef()
+{
+    pthread_once(&sOnceControl, &sOnceInit);
+}
+
+SoundTriggerHalHidl::~SoundTriggerHalHidl()
+{
+}
+
+sp<ISoundTriggerHw> SoundTriggerHalHidl::getService()
+{
+    AutoMutex lock(mLock);
+    if (mISoundTrigger == 0) {
+        if (mModuleName == NULL) {
+            mModuleName = "primary";
+        }
+        std::string serviceName = "sound_trigger.";
+        serviceName.append(mModuleName);
+        mISoundTrigger = ISoundTriggerHw::getService(serviceName);
+    }
+    return mISoundTrigger;
+}
+
+void SoundTriggerHalHidl::clearService()
+{
+    AutoMutex lock(mLock);
+    mISoundTrigger = 0;
+}
+
+sp<SoundTriggerHalHidl::SoundModel> SoundTriggerHalHidl::getModel(sound_model_handle_t handle)
+{
+    AutoMutex lock(mLock);
+    return mSoundModels.valueFor(handle);
+}
+
+sp<SoundTriggerHalHidl::SoundModel> SoundTriggerHalHidl::removeModel(sound_model_handle_t handle)
+{
+    AutoMutex lock(mLock);
+    sp<SoundModel> model = mSoundModels.valueFor(handle);
+    mSoundModels.removeItem(handle);
+    return model;
+}
+
+uint32_t SoundTriggerHalHidl::nextUniqueId()
+{
+    return (uint32_t) atomic_fetch_add_explicit(&mNextUniqueId,
+                (uint_fast32_t) 1, memory_order_acq_rel);
+}
+
+void SoundTriggerHalHidl::convertUuidToHal(Uuid *halUuid,
+                                           const struct sound_trigger_uuid_s *uuid)
+{
+    halUuid->timeLow = uuid->timeLow;
+    halUuid->timeMid = uuid->timeMid;
+    halUuid->versionAndTimeHigh = uuid->timeHiAndVersion;
+    halUuid->variantAndClockSeqHigh = uuid->clockSeq;
+    memcpy(halUuid->node.data(), &uuid->node[0], sizeof(uuid->node));
+}
+
+void SoundTriggerHalHidl::convertUuidFromHal(struct sound_trigger_uuid_s *uuid,
+                                             const Uuid *halUuid)
+{
+    uuid->timeLow = halUuid->timeLow;
+    uuid->timeMid = halUuid->timeMid;
+    uuid->timeHiAndVersion = halUuid->versionAndTimeHigh;
+    uuid->clockSeq = halUuid->variantAndClockSeqHigh;
+    memcpy(&uuid->node[0], halUuid->node.data(), sizeof(uuid->node));
+}
+
+void SoundTriggerHalHidl::convertPropertiesFromHal(
+        struct sound_trigger_properties *properties,
+        const ISoundTriggerHw::Properties *halProperties)
+{
+    strlcpy(properties->implementor,
+            halProperties->implementor.c_str(), SOUND_TRIGGER_MAX_STRING_LEN);
+    strlcpy(properties->description,
+            halProperties->description.c_str(), SOUND_TRIGGER_MAX_STRING_LEN);
+    properties->version = halProperties->version;
+    convertUuidFromHal(&properties->uuid, &halProperties->uuid);
+    properties->max_sound_models = halProperties->maxSoundModels;
+    properties->max_key_phrases = halProperties->maxKeyPhrases;
+    properties->max_users = halProperties->maxUsers;
+    properties->recognition_modes = halProperties->recognitionModes;
+    properties->capture_transition = (bool)halProperties->captureTransition;
+    properties->max_buffer_ms = halProperties->maxBufferMs;
+    properties->concurrent_capture = (bool)halProperties->concurrentCapture;
+    properties->trigger_in_event = (bool)halProperties->triggerInEvent;
+    properties->power_consumption_mw = halProperties->powerConsumptionMw;
+}
+
+void SoundTriggerHalHidl::convertTriggerPhraseToHal(
+        ISoundTriggerHw::Phrase *halTriggerPhrase,
+        const struct sound_trigger_phrase *triggerPhrase)
+{
+    halTriggerPhrase->id = triggerPhrase->id;
+    halTriggerPhrase->recognitionModes = triggerPhrase->recognition_mode;
+    halTriggerPhrase->users.setToExternal((uint32_t *)&triggerPhrase->users[0], triggerPhrase->num_users);
+    halTriggerPhrase->locale = triggerPhrase->locale;
+    halTriggerPhrase->text = triggerPhrase->text;
+}
+
+ISoundTriggerHw::SoundModel *SoundTriggerHalHidl::convertSoundModelToHal(
+        const struct sound_trigger_sound_model *soundModel)
+{
+    ISoundTriggerHw::SoundModel *halModel = NULL;
+    if (soundModel->type == SOUND_MODEL_TYPE_KEYPHRASE) {
+        ISoundTriggerHw::PhraseSoundModel *halKeyPhraseModel =
+                new ISoundTriggerHw::PhraseSoundModel();
+        struct sound_trigger_phrase_sound_model *keyPhraseModel =
+                (struct sound_trigger_phrase_sound_model *)soundModel;
+        ISoundTriggerHw::Phrase *halPhrases =
+                new ISoundTriggerHw::Phrase[keyPhraseModel->num_phrases];
+
+
+        for (unsigned int i = 0; i < keyPhraseModel->num_phrases; i++) {
+            convertTriggerPhraseToHal(&halPhrases[i],
+                                      &keyPhraseModel->phrases[i]);
+        }
+        halKeyPhraseModel->phrases.setToExternal(halPhrases, keyPhraseModel->num_phrases);
+        // FIXME: transfer buffer ownership. should have a method for that in hidl_vec
+        halKeyPhraseModel->phrases.resize(keyPhraseModel->num_phrases);
+
+        delete[] halPhrases;
+
+        halModel = (ISoundTriggerHw::SoundModel *)halKeyPhraseModel;
+    } else {
+        halModel = new ISoundTriggerHw::SoundModel();
+    }
+    halModel->type = (SoundModelType)soundModel->type;
+    convertUuidToHal(&halModel->uuid, &soundModel->uuid);
+    convertUuidToHal(&halModel->vendorUuid, &soundModel->vendor_uuid);
+    halModel->data.setToExternal((uint8_t *)soundModel + soundModel->data_offset, soundModel->data_size);
+    halModel->data.resize(soundModel->data_size);
+
+    return halModel;
+}
+
+void SoundTriggerHalHidl::convertPhraseRecognitionExtraToHal(
+        PhraseRecognitionExtra *halExtra,
+        const struct sound_trigger_phrase_recognition_extra *extra)
+{
+    halExtra->id = extra->id;
+    halExtra->recognitionModes = extra->recognition_modes;
+    halExtra->confidenceLevel = extra->confidence_level;
+    ConfidenceLevel *halLevels =
+            new ConfidenceLevel[extra->num_levels];
+    for (unsigned int i = 0; i < extra->num_levels; i++) {
+        halLevels[i].userId = extra->levels[i].user_id;
+        halLevels[i].levelPercent = extra->levels[i].level;
+    }
+    halExtra->levels.setToExternal(halLevels, extra->num_levels);
+    // FIXME: transfer buffer ownership. should have a method for that in hidl_vec
+    halExtra->levels.resize(extra->num_levels);
+
+    delete[] halLevels;
+}
+
+
+ISoundTriggerHw::RecognitionConfig *SoundTriggerHalHidl::convertRecognitionConfigToHal(
+        const struct sound_trigger_recognition_config *config)
+{
+    ISoundTriggerHw::RecognitionConfig *halConfig =
+            new ISoundTriggerHw::RecognitionConfig();
+
+    halConfig->captureHandle = config->capture_handle;
+    halConfig->captureDevice = (AudioDevice)config->capture_device;
+    halConfig->captureRequested = (uint32_t)config->capture_requested;
+
+    PhraseRecognitionExtra *halExtras =
+            new PhraseRecognitionExtra[config->num_phrases];
+
+    for (unsigned int i = 0; i < config->num_phrases; i++) {
+        convertPhraseRecognitionExtraToHal(&halExtras[i],
+                                  &config->phrases[i]);
+    }
+    halConfig->phrases.setToExternal(halExtras, config->num_phrases);
+    // FIXME: transfer buffer ownership. should have a method for that in hidl_vec
+    halConfig->phrases.resize(config->num_phrases);
+
+    delete[] halExtras;
+
+    halConfig->data.setToExternal((uint8_t *)config + config->data_offset, config->data_size);
+
+    return halConfig;
+}
+
+
+// ISoundTriggerHwCallback
+::android::hardware::Return<void> SoundTriggerHalHidl::recognitionCallback(
+        const ISoundTriggerHwCallback::RecognitionEvent& halEvent,
+        CallbackCookie cookie)
+{
+    sp<SoundModel> model;
+    {
+        AutoMutex lock(mLock);
+        model = mSoundModels.valueFor((SoundModelHandle)cookie);
+        if (model == 0) {
+            return Return<void>();
+        }
+    }
+    struct sound_trigger_recognition_event *event = convertRecognitionEventFromHal(&halEvent);
+    if (event == NULL) {
+        return Return<void>();
+    }
+    event->model = model->mHandle;
+    model->mRecognitionCallback(event, model->mRecognitionCookie);
+
+    free(event);
+
+    return Return<void>();
+}
+
+::android::hardware::Return<void> SoundTriggerHalHidl::phraseRecognitionCallback(
+        const ISoundTriggerHwCallback::PhraseRecognitionEvent& halEvent,
+        CallbackCookie cookie)
+{
+    sp<SoundModel> model;
+    {
+        AutoMutex lock(mLock);
+        model = mSoundModels.valueFor((SoundModelHandle)cookie);
+        if (model == 0) {
+            return Return<void>();
+        }
+    }
+
+    struct sound_trigger_recognition_event *event = convertRecognitionEventFromHal(
+                                   (const ISoundTriggerHwCallback::RecognitionEvent *)&halEvent);
+    if (event == NULL) {
+        return Return<void>();
+    }
+
+    event->model = model->mHandle;
+    model->mRecognitionCallback(event, model->mRecognitionCookie);
+
+    free(event);
+
+    return Return<void>();
+}
+
+::android::hardware::Return<void> SoundTriggerHalHidl::soundModelCallback(
+        const ISoundTriggerHwCallback::ModelEvent& halEvent,
+        CallbackCookie cookie)
+{
+    sp<SoundModel> model;
+    {
+        AutoMutex lock(mLock);
+        model = mSoundModels.valueFor((SoundModelHandle)cookie);
+        if (model == 0) {
+            return Return<void>();
+        }
+    }
+
+    struct sound_trigger_model_event *event = convertSoundModelEventFromHal(&halEvent);
+    if (event == NULL) {
+        return Return<void>();
+    }
+
+    event->model = model->mHandle;
+    model->mSoundModelCallback(event, model->mSoundModelCookie);
+
+    free(event);
+
+    return Return<void>();
+}
+
+
+struct sound_trigger_model_event *SoundTriggerHalHidl::convertSoundModelEventFromHal(
+                                              const ISoundTriggerHwCallback::ModelEvent *halEvent)
+{
+    struct sound_trigger_model_event *event = (struct sound_trigger_model_event *)malloc(
+            sizeof(struct sound_trigger_model_event) +
+            halEvent->data.size());
+    if (event == NULL) {
+        return NULL;
+    }
+
+    event->status = (int)halEvent->status;
+    // event->model to be set by caller
+    event->data_offset = sizeof(struct sound_trigger_model_event);
+    event->data_size = halEvent->data.size();
+    uint8_t *dst = (uint8_t *)event + event->data_offset;
+    uint8_t *src = (uint8_t *)&halEvent->data[0];
+    memcpy(dst, src, halEvent->data.size());
+
+    return event;
+}
+
+void SoundTriggerHalHidl::convertPhraseRecognitionExtraFromHal(
+        struct sound_trigger_phrase_recognition_extra *extra,
+        const PhraseRecognitionExtra *halExtra)
+{
+    extra->id = halExtra->id;
+    extra->recognition_modes = halExtra->recognitionModes;
+    extra->confidence_level = halExtra->confidenceLevel;
+
+    size_t i;
+    for (i = 0; i < halExtra->levels.size() && i < SOUND_TRIGGER_MAX_USERS; i++) {
+        extra->levels[i].user_id = halExtra->levels[i].userId;
+        extra->levels[i].level = halExtra->levels[i].levelPercent;
+    }
+    extra->num_levels = (unsigned int)i;
+}
+
+
+struct sound_trigger_recognition_event *SoundTriggerHalHidl::convertRecognitionEventFromHal(
+        const ISoundTriggerHwCallback::RecognitionEvent *halEvent)
+{
+    struct sound_trigger_recognition_event *event;
+
+    if (halEvent->type == SoundModelType::KEYPHRASE) {
+        struct sound_trigger_phrase_recognition_event *phraseEvent =
+                (struct sound_trigger_phrase_recognition_event *)malloc(
+                        sizeof(struct sound_trigger_phrase_recognition_event) +
+                        halEvent->data.size());
+        if (phraseEvent == NULL) {
+            return NULL;
+        }
+        const ISoundTriggerHwCallback::PhraseRecognitionEvent *halPhraseEvent =
+                (const ISoundTriggerHwCallback::PhraseRecognitionEvent *)halEvent;
+
+        for (unsigned int i = 0; i < halPhraseEvent->phraseExtras.size(); i++) {
+            convertPhraseRecognitionExtraFromHal(&phraseEvent->phrase_extras[i],
+                                                 &halPhraseEvent->phraseExtras[i]);
+        }
+        phraseEvent->num_phrases = halPhraseEvent->phraseExtras.size();
+        event = (struct sound_trigger_recognition_event *)phraseEvent;
+        event->data_offset = sizeof(sound_trigger_phrase_recognition_event);
+    } else {
+        event = (struct sound_trigger_recognition_event *)malloc(
+                sizeof(struct sound_trigger_recognition_event) + halEvent->data.size());
+        if (event == NULL) {
+            return NULL;
+        }
+        event->data_offset = sizeof(sound_trigger_recognition_event);
+    }
+    event->status = (int)halEvent->status;
+    event->type = (sound_trigger_sound_model_type_t)halEvent->type;
+    // event->model to be set by caller
+    event->capture_available = (bool)halEvent->captureAvailable;
+    event->capture_session = halEvent->captureSession;
+    event->capture_delay_ms = halEvent->captureDelayMs;
+    event->capture_preamble_ms = halEvent->capturePreambleMs;
+    event->trigger_in_data = (bool)halEvent->triggerInData;
+    event->audio_config.sample_rate = halEvent->audioConfig.sampleRateHz;
+    event->audio_config.channel_mask = (audio_channel_mask_t)halEvent->audioConfig.channelMask;
+    event->audio_config.format = (audio_format_t)halEvent->audioConfig.format;
+
+    event->data_size = halEvent->data.size();
+    uint8_t *dst = (uint8_t *)event + event->data_offset;
+    uint8_t *src = (uint8_t *)&halEvent->data[0];
+    memcpy(dst, src, halEvent->data.size());
+
+    return event;
+}
+
+} // namespace android
diff --git a/services/soundtrigger/SoundTriggerHalHidl.h b/services/soundtrigger/SoundTriggerHalHidl.h
new file mode 100644
index 0000000..9b0d7a7
--- /dev/null
+++ b/services/soundtrigger/SoundTriggerHalHidl.h
@@ -0,0 +1,167 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef ANDROID_HARDWARE_SOUNDTRIGGER_HAL_HIDL_H
+#define ANDROID_HARDWARE_SOUNDTRIGGER_HAL_HIDL_H
+
+#include <utils/RefBase.h>
+#include <utils/KeyedVector.h>
+#include <utils/Vector.h>
+#include <utils/threads.h>
+#include "SoundTriggerHalInterface.h"
+#include <android/hardware/soundtrigger/2.0/types.h>
+#include <android/hardware/soundtrigger/2.0/ISoundTriggerHw.h>
+#include <android/hardware/soundtrigger/2.0/ISoundTriggerHwCallback.h>
+#include <android/hardware/soundtrigger/2.0/BnSoundTriggerHwCallback.h>
+
+namespace android {
+
+using android::hardware::audio::common::V2_0::Uuid;
+using android::hardware::soundtrigger::V2_0::ConfidenceLevel;
+using android::hardware::soundtrigger::V2_0::PhraseRecognitionExtra;
+using android::hardware::soundtrigger::V2_0::SoundModelType;
+using android::hardware::soundtrigger::V2_0::SoundModelHandle;
+using android::hardware::soundtrigger::V2_0::ISoundTriggerHw;
+using android::hardware::soundtrigger::V2_0::ISoundTriggerHwCallback;
+
+class SoundTriggerHalHidl : public SoundTriggerHalInterface,
+                            public virtual ISoundTriggerHwCallback
+
+{
+public:
+        virtual int getProperties(struct sound_trigger_properties *properties);
+
+        /*
+         * Load a sound model. Once loaded, recognition of this model can be started and stopped.
+         * Only one active recognition per model at a time. The SoundTrigger service will handle
+         * concurrent recognition requests by different users/applications on the same model.
+         * The implementation returns a unique handle used by other functions (unload_sound_model(),
+         * start_recognition(), etc...
+         */
+        virtual int loadSoundModel(struct sound_trigger_sound_model *sound_model,
+                                sound_model_callback_t callback,
+                                void *cookie,
+                                sound_model_handle_t *handle);
+
+        /*
+         * Unload a sound model. A sound model can be unloaded to make room for a new one to overcome
+         * implementation limitations.
+         */
+        virtual int unloadSoundModel(sound_model_handle_t handle);
+
+        /* Start recognition on a given model. Only one recognition active at a time per model.
+         * Once recognition succeeds of fails, the callback is called.
+         * TODO: group recognition configuration parameters into one struct and add key phrase options.
+         */
+        virtual int startRecognition(sound_model_handle_t handle,
+                                 const struct sound_trigger_recognition_config *config,
+                                 recognition_callback_t callback,
+                                 void *cookie);
+
+        /* Stop recognition on a given model.
+         * The implementation does not have to call the callback when stopped via this method.
+         */
+        virtual int stopRecognition(sound_model_handle_t handle);
+
+        /* Stop recognition on all models.
+         * Only supported for device api versions SOUND_TRIGGER_DEVICE_API_VERSION_1_1 or above.
+         * If no implementation is provided, stop_recognition will be called for each running model.
+         */
+        virtual int stopAllRecognitions();
+
+        // RefBase
+        virtual     void        onFirstRef();
+
+        // ISoundTriggerHwCallback
+        virtual ::android::hardware::Return<void> recognitionCallback(
+                const ISoundTriggerHwCallback::RecognitionEvent& event, CallbackCookie cookie);
+        virtual ::android::hardware::Return<void> phraseRecognitionCallback(
+                const ISoundTriggerHwCallback::PhraseRecognitionEvent& event, int32_t cookie);
+        virtual ::android::hardware::Return<void> soundModelCallback(
+                const ISoundTriggerHwCallback::ModelEvent& event, CallbackCookie cookie);
+private:
+        class SoundModel : public RefBase {
+        public:
+            SoundModel(sound_model_handle_t handle, sound_model_callback_t callback,
+                       void *cookie, android::hardware::soundtrigger::V2_0::SoundModelHandle halHandle)
+                 : mHandle(handle), mHalHandle(halHandle),
+                   mSoundModelCallback(callback), mSoundModelCookie(cookie),
+                   mRecognitionCallback(NULL), mRecognitionCookie(NULL) {}
+            ~SoundModel() {}
+
+            sound_model_handle_t   mHandle;
+            android::hardware::soundtrigger::V2_0::SoundModelHandle mHalHandle;
+            sound_model_callback_t mSoundModelCallback;
+            void *                 mSoundModelCookie;
+            recognition_callback_t mRecognitionCallback;
+            void *                 mRecognitionCookie;
+        };
+
+        friend class SoundTriggerHalInterface;
+
+        explicit SoundTriggerHalHidl(const char *moduleName = NULL);
+        virtual  ~SoundTriggerHalHidl();
+
+        void convertUuidToHal(Uuid *halUuid,
+                              const struct sound_trigger_uuid_s *uuid);
+        void convertUuidFromHal(struct sound_trigger_uuid_s *uuid,
+                                const Uuid *halUuid);
+
+        void convertPropertiesFromHal(
+                struct sound_trigger_properties *properties,
+                const ISoundTriggerHw::Properties *halProperties);
+
+        void convertTriggerPhraseToHal(
+                ISoundTriggerHw::Phrase *halTriggerPhrase,
+                const struct sound_trigger_phrase *triggerPhrase);
+        ISoundTriggerHw::SoundModel *convertSoundModelToHal(
+                const struct sound_trigger_sound_model *soundModel);
+
+        void convertPhraseRecognitionExtraToHal(
+                PhraseRecognitionExtra *halExtra,
+                const struct sound_trigger_phrase_recognition_extra *extra);
+        ISoundTriggerHw::RecognitionConfig *convertRecognitionConfigToHal(
+                const struct sound_trigger_recognition_config *config);
+
+        struct sound_trigger_model_event *convertSoundModelEventFromHal(
+                                              const ISoundTriggerHwCallback::ModelEvent *halEvent);
+        void convertPhraseRecognitionExtraFromHal(
+                struct sound_trigger_phrase_recognition_extra *extra,
+                const PhraseRecognitionExtra *halExtra);
+        struct sound_trigger_recognition_event *convertRecognitionEventFromHal(
+                const ISoundTriggerHwCallback::RecognitionEvent *halEvent);
+
+        uint32_t nextUniqueId();
+        sp<ISoundTriggerHw> getService();
+        void clearService();
+        sp<SoundModel> getModel(sound_model_handle_t handle);
+        sp<SoundModel> removeModel(sound_model_handle_t handle);
+
+        static pthread_once_t sOnceControl;
+        static void sOnceInit();
+
+        Mutex mLock;
+        Mutex mHalLock;
+        const char *mModuleName;
+        volatile atomic_uint_fast32_t  mNextUniqueId;
+        // Effect chains without a valid thread
+        DefaultKeyedVector< sound_model_handle_t , sp<SoundModel> > mSoundModels;
+        sp<::android::hardware::soundtrigger::V2_0::ISoundTriggerHw> mISoundTrigger;
+};
+
+} // namespace android
+
+#endif // ANDROID_HARDWARE_SOUNDTRIGGER_HAL_HIDL_H
diff --git a/services/soundtrigger/SoundTriggerHalInterface.h b/services/soundtrigger/SoundTriggerHalInterface.h
new file mode 100644
index 0000000..c083195
--- /dev/null
+++ b/services/soundtrigger/SoundTriggerHalInterface.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef ANDROID_HARDWARE_SOUNDTRIGGER_HAL_INTERFACE_H
+#define ANDROID_HARDWARE_SOUNDTRIGGER_HAL_INTERFACE_H
+
+#include <utils/RefBase.h>
+#include <system/sound_trigger.h>
+#include <hardware/sound_trigger.h>
+
+namespace android {
+
+class SoundTriggerHalInterface : public virtual RefBase
+{
+public:
+        /* get a sound trigger HAL instance */
+        static sp<SoundTriggerHalInterface> connectModule(const char *moduleName);
+
+        virtual     ~SoundTriggerHalInterface() {}
+
+        virtual int getProperties(struct sound_trigger_properties *properties) = 0;
+
+        /*
+         * Load a sound model. Once loaded, recognition of this model can be started and stopped.
+         * Only one active recognition per model at a time. The SoundTrigger service will handle
+         * concurrent recognition requests by different users/applications on the same model.
+         * The implementation returns a unique handle used by other functions (unload_sound_model(),
+         * start_recognition(), etc...
+         */
+        virtual int loadSoundModel(struct sound_trigger_sound_model *sound_model,
+                                sound_model_callback_t callback,
+                                void *cookie,
+                                sound_model_handle_t *handle) = 0;
+
+        /*
+         * Unload a sound model. A sound model can be unloaded to make room for a new one to overcome
+         * implementation limitations.
+         */
+        virtual int unloadSoundModel(sound_model_handle_t handle) = 0;
+
+        /* Start recognition on a given model. Only one recognition active at a time per model.
+         * Once recognition succeeds of fails, the callback is called.
+         * TODO: group recognition configuration parameters into one struct and add key phrase options.
+         */
+        virtual int startRecognition(sound_model_handle_t handle,
+                                 const struct sound_trigger_recognition_config *config,
+                                 recognition_callback_t callback,
+                                 void *cookie) = 0;
+
+        /* Stop recognition on a given model.
+         * The implementation does not have to call the callback when stopped via this method.
+         */
+        virtual int stopRecognition(sound_model_handle_t handle) = 0;
+
+        /* Stop recognition on all models.
+         * Only supported for device api versions SOUND_TRIGGER_DEVICE_API_VERSION_1_1 or above.
+         * If no implementation is provided, stop_recognition will be called for each running model.
+         */
+        virtual int stopAllRecognitions() = 0;
+
+protected:
+        SoundTriggerHalInterface() {}
+};
+
+} // namespace android
+
+#endif // ANDROID_HARDWARE_SOUNDTRIGGER_HAL_INTERFACE_H
diff --git a/services/soundtrigger/SoundTriggerHalLegacy.cpp b/services/soundtrigger/SoundTriggerHalLegacy.cpp
new file mode 100644
index 0000000..2b78818
--- /dev/null
+++ b/services/soundtrigger/SoundTriggerHalLegacy.cpp
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 2016 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 <utils/Log.h>
+#include "SoundTriggerHalLegacy.h"
+
+namespace android {
+
+/* static */
+sp<SoundTriggerHalInterface> SoundTriggerHalInterface::connectModule(const char *moduleName)
+{
+    return new SoundTriggerHalLegacy(moduleName);
+}
+
+SoundTriggerHalLegacy::SoundTriggerHalLegacy(const char *moduleName)
+    : mModuleName(moduleName), mHwDevice(NULL)
+{
+}
+
+void SoundTriggerHalLegacy::onFirstRef()
+{
+    const hw_module_t *mod;
+    int rc;
+
+    if (mModuleName == NULL) {
+        mModuleName = "primary";
+    }
+
+    rc = hw_get_module_by_class(SOUND_TRIGGER_HARDWARE_MODULE_ID, mModuleName, &mod);
+    if (rc != 0) {
+        ALOGE("couldn't load sound trigger module %s.%s (%s)",
+              SOUND_TRIGGER_HARDWARE_MODULE_ID, mModuleName, strerror(-rc));
+        return;
+    }
+    rc = sound_trigger_hw_device_open(mod, &mHwDevice);
+    if (rc != 0) {
+        ALOGE("couldn't open sound trigger hw device in %s.%s (%s)",
+              SOUND_TRIGGER_HARDWARE_MODULE_ID, mModuleName, strerror(-rc));
+        mHwDevice = NULL;
+        return;
+    }
+    if (mHwDevice->common.version < SOUND_TRIGGER_DEVICE_API_VERSION_1_0 ||
+            mHwDevice->common.version > SOUND_TRIGGER_DEVICE_API_VERSION_CURRENT) {
+        ALOGE("wrong sound trigger hw device version %04x", mHwDevice->common.version);
+        return;
+    }
+}
+
+SoundTriggerHalLegacy::~SoundTriggerHalLegacy()
+{
+    if (mHwDevice != NULL) {
+        sound_trigger_hw_device_close(mHwDevice);
+    }
+}
+
+int SoundTriggerHalLegacy::getProperties(struct sound_trigger_properties *properties)
+{
+    if (mHwDevice == NULL) {
+        return -ENODEV;
+    }
+    return mHwDevice->get_properties(mHwDevice, properties);
+}
+
+int SoundTriggerHalLegacy::loadSoundModel(struct sound_trigger_sound_model *sound_model,
+                        sound_model_callback_t callback,
+                        void *cookie,
+                        sound_model_handle_t *handle)
+{
+    if (mHwDevice == NULL) {
+        return -ENODEV;
+    }
+    return mHwDevice->load_sound_model(mHwDevice, sound_model, callback, cookie, handle);
+}
+
+int SoundTriggerHalLegacy::unloadSoundModel(sound_model_handle_t handle)
+{
+    if (mHwDevice == NULL) {
+        return -ENODEV;
+    }
+    return mHwDevice->unload_sound_model(mHwDevice, handle);
+}
+
+int SoundTriggerHalLegacy::startRecognition(sound_model_handle_t handle,
+                         const struct sound_trigger_recognition_config *config,
+                         recognition_callback_t callback,
+                         void *cookie)
+{
+    if (mHwDevice == NULL) {
+        return -ENODEV;
+    }
+    return mHwDevice->start_recognition(mHwDevice, handle, config, callback, cookie);
+}
+
+int SoundTriggerHalLegacy::stopRecognition(sound_model_handle_t handle)
+{
+    if (mHwDevice == NULL) {
+        return -ENODEV;
+    }
+    return mHwDevice->stop_recognition(mHwDevice, handle);
+}
+
+int SoundTriggerHalLegacy::stopAllRecognitions()
+{
+    if (mHwDevice == NULL) {
+        return -ENODEV;
+    }
+    if (mHwDevice->common.version >= SOUND_TRIGGER_DEVICE_API_VERSION_1_1 &&
+     mHwDevice->stop_all_recognitions) {
+        return mHwDevice->stop_all_recognitions(mHwDevice);
+    }
+    return -ENOSYS;
+}
+
+} // namespace android
diff --git a/services/soundtrigger/SoundTriggerHalLegacy.h b/services/soundtrigger/SoundTriggerHalLegacy.h
new file mode 100644
index 0000000..52488de
--- /dev/null
+++ b/services/soundtrigger/SoundTriggerHalLegacy.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef ANDROID_HARDWARE_SOUNDTRIGGER_HAL_LEGACY_H
+#define ANDROID_HARDWARE_SOUNDTRIGGER_HAL_LEGACY_H
+
+#include "SoundTriggerHalInterface.h"
+
+namespace android {
+
+class SoundTriggerHalLegacy : public SoundTriggerHalInterface
+
+{
+public:
+        virtual             ~SoundTriggerHalLegacy();
+
+        virtual int getProperties(struct sound_trigger_properties *properties);
+
+        /*
+         * Load a sound model. Once loaded, recognition of this model can be started and stopped.
+         * Only one active recognition per model at a time. The SoundTrigger service will handle
+         * concurrent recognition requests by different users/applications on the same model.
+         * The implementation returns a unique handle used by other functions (unload_sound_model(),
+         * start_recognition(), etc...
+         */
+        virtual int loadSoundModel(struct sound_trigger_sound_model *sound_model,
+                                sound_model_callback_t callback,
+                                void *cookie,
+                                sound_model_handle_t *handle);
+
+        /*
+         * Unload a sound model. A sound model can be unloaded to make room for a new one to overcome
+         * implementation limitations.
+         */
+        virtual int unloadSoundModel(sound_model_handle_t handle);
+
+        /* Start recognition on a given model. Only one recognition active at a time per model.
+         * Once recognition succeeds of fails, the callback is called.
+         * TODO: group recognition configuration parameters into one struct and add key phrase options.
+         */
+        virtual int startRecognition(sound_model_handle_t handle,
+                                 const struct sound_trigger_recognition_config *config,
+                                 recognition_callback_t callback,
+                                 void *cookie);
+
+        /* Stop recognition on a given model.
+         * The implementation does not have to call the callback when stopped via this method.
+         */
+        virtual int stopRecognition(sound_model_handle_t handle);
+
+        /* Stop recognition on all models.
+         * Only supported for device api versions SOUND_TRIGGER_DEVICE_API_VERSION_1_1 or above.
+         * If no implementation is provided, stop_recognition will be called for each running model.
+         */
+        int stopAllRecognitions();
+
+        // RefBase
+        virtual     void        onFirstRef();
+
+private:
+
+        friend class SoundTriggerHalInterface;
+
+        explicit SoundTriggerHalLegacy(const char *moduleName = NULL);
+
+        const char *mModuleName;
+        struct sound_trigger_hw_device*        mHwDevice;
+};
+
+} // namespace android
+
+#endif // ANDROID_HARDWARE_SOUNDTRIGGER_HAL_LEGACY_H
diff --git a/services/soundtrigger/SoundTriggerHwService.cpp b/services/soundtrigger/SoundTriggerHwService.cpp
index 6a52b9c..3ba7f62 100644
--- a/services/soundtrigger/SoundTriggerHwService.cpp
+++ b/services/soundtrigger/SoundTriggerHwService.cpp
@@ -32,17 +32,16 @@
 #include <binder/IServiceManager.h>
 #include <binder/MemoryBase.h>
 #include <binder/MemoryHeapBase.h>
-#include <hardware/sound_trigger.h>
+#include <system/sound_trigger.h>
 #include <ServiceUtilities.h>
 #include "SoundTriggerHwService.h"
 
-namespace android {
-
 #ifdef SOUND_TRIGGER_USE_STUB_MODULE
 #define HW_MODULE_PREFIX "stub"
 #else
 #define HW_MODULE_PREFIX "primary"
 #endif
+namespace android {
 
 SoundTriggerHwService::SoundTriggerHwService()
     : BnSoundTriggerHwService(),
@@ -54,30 +53,17 @@
 
 void SoundTriggerHwService::onFirstRef()
 {
-    const hw_module_t *mod;
     int rc;
-    sound_trigger_hw_device *dev;
 
-    rc = hw_get_module_by_class(SOUND_TRIGGER_HARDWARE_MODULE_ID, HW_MODULE_PREFIX, &mod);
-    if (rc != 0) {
-        ALOGE("couldn't load sound trigger module %s.%s (%s)",
-              SOUND_TRIGGER_HARDWARE_MODULE_ID, HW_MODULE_PREFIX, strerror(-rc));
-        return;
-    }
-    rc = sound_trigger_hw_device_open(mod, &dev);
-    if (rc != 0) {
-        ALOGE("couldn't open sound trigger hw device in %s.%s (%s)",
-              SOUND_TRIGGER_HARDWARE_MODULE_ID, HW_MODULE_PREFIX, strerror(-rc));
-        return;
-    }
-    if (dev->common.version < SOUND_TRIGGER_DEVICE_API_VERSION_1_0 ||
-        dev->common.version > SOUND_TRIGGER_DEVICE_API_VERSION_CURRENT) {
-        ALOGE("wrong sound trigger hw device version %04x", dev->common.version);
-        return;
-    }
+    sp<SoundTriggerHalInterface> halInterface =
+            SoundTriggerHalInterface::connectModule(HW_MODULE_PREFIX);
 
+    if (halInterface == 0) {
+        ALOGW("could not connect to HAL");
+        return;
+    }
     sound_trigger_module_descriptor descriptor;
-    rc = dev->get_properties(dev, &descriptor.properties);
+    rc = halInterface->getProperties(&descriptor.properties);
     if (rc != 0) {
         ALOGE("could not read implementation properties");
         return;
@@ -88,7 +74,7 @@
                                                  descriptor.handle);
 
     sp<ISoundTriggerClient> client;
-    sp<Module> module = new Module(this, dev, descriptor, client);
+    sp<Module> module = new Module(this, halInterface, descriptor, client);
     mModules.add(descriptor.handle, module);
     mCallbackThread = new CallbackThread(this);
 }
@@ -98,9 +84,6 @@
     if (mCallbackThread != 0) {
         mCallbackThread->exit();
     }
-    for (size_t i = 0; i < mModules.size(); i++) {
-        sound_trigger_hw_device_close(mModules.valueAt(i)->hwDevice());
-    }
 }
 
 status_t SoundTriggerHwService::listModules(struct sound_trigger_module_descriptor *modules,
@@ -489,10 +472,10 @@
 #define LOG_TAG "SoundTriggerHwService::Module"
 
 SoundTriggerHwService::Module::Module(const sp<SoundTriggerHwService>& service,
-                                      sound_trigger_hw_device* hwDevice,
+                                      const sp<SoundTriggerHalInterface>& halInterface,
                                       sound_trigger_module_descriptor descriptor,
                                       const sp<ISoundTriggerClient>& client)
- : mService(service), mHwDevice(hwDevice), mDescriptor(descriptor),
+ : mService(service), mHalInterface(halInterface), mDescriptor(descriptor),
    mClient(client), mServiceState(SOUND_TRIGGER_STATE_NO_INIT)
 {
 }
@@ -510,10 +493,12 @@
         for (size_t i = 0; i < mModels.size(); i++) {
             sp<Model> model = mModels.valueAt(i);
             ALOGV("detach() unloading model %d", model->mHandle);
-            if (model->mState == Model::STATE_ACTIVE) {
-                mHwDevice->stop_recognition(mHwDevice, model->mHandle);
+            if (mHalInterface != 0) {
+                if (model->mState == Model::STATE_ACTIVE) {
+                    mHalInterface->stopRecognition(model->mHandle);
+                }
+                mHalInterface->unloadSoundModel(model->mHandle);
             }
-            mHwDevice->unload_sound_model(mHwDevice, model->mHandle);
         }
         mModels.clear();
     }
@@ -531,10 +516,12 @@
                                 sound_model_handle_t *handle)
 {
     ALOGV("loadSoundModel() handle");
+    if (mHalInterface == 0) {
+        return NO_INIT;
+    }
     if (!captureHotwordAllowed()) {
         return PERMISSION_DENIED;
     }
-
     if (modelMemory == 0 || modelMemory->pointer() == NULL) {
         ALOGE("loadSoundModel() modelMemory is 0 or has NULL pointer()");
         return BAD_VALUE;
@@ -566,7 +553,7 @@
         return INVALID_OPERATION;
     }
 
-    status_t status = mHwDevice->load_sound_model(mHwDevice, sound_model,
+    status_t status = mHalInterface->loadSoundModel(sound_model,
                                                   SoundTriggerHwService::soundModelCallback,
                                                   this, handle);
 
@@ -601,6 +588,9 @@
 
 status_t SoundTriggerHwService::Module::unloadSoundModel_l(sound_model_handle_t handle)
 {
+    if (mHalInterface == 0) {
+        return NO_INIT;
+    }
     ssize_t index = mModels.indexOfKey(handle);
     if (index < 0) {
         return BAD_VALUE;
@@ -608,17 +598,20 @@
     sp<Model> model = mModels.valueAt(index);
     mModels.removeItem(handle);
     if (model->mState == Model::STATE_ACTIVE) {
-        mHwDevice->stop_recognition(mHwDevice, model->mHandle);
+        mHalInterface->stopRecognition(model->mHandle);
         model->mState = Model::STATE_IDLE;
     }
     AudioSystem::releaseSoundTriggerSession(model->mCaptureSession);
-    return mHwDevice->unload_sound_model(mHwDevice, handle);
+    return mHalInterface->unloadSoundModel(handle);
 }
 
 status_t SoundTriggerHwService::Module::startRecognition(sound_model_handle_t handle,
                                  const sp<IMemory>& dataMemory)
 {
     ALOGV("startRecognition() model handle %d", handle);
+    if (mHalInterface == 0) {
+        return NO_INIT;
+    }
     if (!captureHotwordAllowed()) {
         return PERMISSION_DENIED;
     }
@@ -657,7 +650,7 @@
     //TODO: get capture handle and device from audio policy service
     config->capture_handle = model->mCaptureIOHandle;
     config->capture_device = model->mCaptureDevice;
-    status_t status = mHwDevice->start_recognition(mHwDevice, handle, config,
+    status_t status = mHalInterface->startRecognition(handle, config,
                                         SoundTriggerHwService::recognitionCallback,
                                         this);
 
@@ -672,6 +665,9 @@
 status_t SoundTriggerHwService::Module::stopRecognition(sound_model_handle_t handle)
 {
     ALOGV("stopRecognition() model handle %d", handle);
+    if (mHalInterface == 0) {
+        return NO_INIT;
+    }
     if (!captureHotwordAllowed()) {
         return PERMISSION_DENIED;
     }
@@ -685,7 +681,7 @@
     if (model->mState != Model::STATE_ACTIVE) {
         return INVALID_OPERATION;
     }
-    mHwDevice->stop_recognition(mHwDevice, handle);
+    mHalInterface->stopRecognition(handle);
     model->mState = Model::STATE_IDLE;
     return NO_ERROR;
 }
@@ -808,18 +804,13 @@
         }
 
         const bool supports_stop_all =
-            (mHwDevice->common.version >= SOUND_TRIGGER_DEVICE_API_VERSION_1_1 &&
-             mHwDevice->stop_all_recognitions);
-
-        if (supports_stop_all) {
-            mHwDevice->stop_all_recognitions(mHwDevice);
-        }
+                (mHalInterface != 0) && (mHalInterface->stopAllRecognitions() == ENOSYS);
 
         for (size_t i = 0; i < mModels.size(); i++) {
             sp<Model> model = mModels.valueAt(i);
             if (model->mState == Model::STATE_ACTIVE) {
-                if (!supports_stop_all) {
-                    mHwDevice->stop_recognition(mHwDevice, model->mHandle);
+                if (mHalInterface != 0 && !supports_stop_all) {
+                    mHalInterface->stopRecognition(model->mHandle);
                 }
                 // keep model in ACTIVE state so that event is processed by onCallbackEvent()
                 if (model->mType == SOUND_MODEL_TYPE_KEYPHRASE) {
diff --git a/services/soundtrigger/SoundTriggerHwService.h b/services/soundtrigger/SoundTriggerHwService.h
index 13a577a..7f7d0cc 100644
--- a/services/soundtrigger/SoundTriggerHwService.h
+++ b/services/soundtrigger/SoundTriggerHwService.h
@@ -26,7 +26,7 @@
 #include <soundtrigger/ISoundTrigger.h>
 #include <soundtrigger/ISoundTriggerClient.h>
 #include <system/sound_trigger.h>
-#include <hardware/sound_trigger.h>
+#include "SoundTriggerHalInterface.h"
 
 namespace android {
 
@@ -103,7 +103,7 @@
     public:
 
        Module(const sp<SoundTriggerHwService>& service,
-              sound_trigger_hw_device* hwDevice,
+              const sp<SoundTriggerHalInterface>& halInterface,
               sound_trigger_module_descriptor descriptor,
               const sp<ISoundTriggerClient>& client);
 
@@ -123,7 +123,6 @@
        virtual status_t dump(int fd, const Vector<String16>& args);
 
 
-       sound_trigger_hw_device *hwDevice() const { return mHwDevice; }
        struct sound_trigger_module_descriptor descriptor() { return mDescriptor; }
        void setClient(const sp<ISoundTriggerClient>& client) { mClient = client; }
        void clearClient() { mClient.clear(); }
@@ -146,7 +145,7 @@
 
         Mutex                                  mLock;
         wp<SoundTriggerHwService>              mService;
-        struct sound_trigger_hw_device*        mHwDevice;
+        sp<SoundTriggerHalInterface>           mHalInterface;
         struct sound_trigger_module_descriptor mDescriptor;
         sp<ISoundTriggerClient>                mClient;
         DefaultKeyedVector< sound_model_handle_t, sp<Model> >     mModels;