diff --git a/hal/Android.mk b/hal/Android.mk
index 38873cf..4e1364b 100644
--- a/hal/Android.mk
+++ b/hal/Android.mk
@@ -190,6 +190,11 @@
     LOCAL_CFLAGS += -DHDMI_PASSTHROUGH_ENABLED
 endif
 
+ifeq ($(strip $(AUDIO_FEATURE_ENABLED_SOURCE_TRACKING)),true)
+    LOCAL_CFLAGS += -DSOURCE_TRACKING_ENABLED
+    LOCAL_SRC_FILES += audio_extn/source_track.c
+endif
+
 LOCAL_SHARED_LIBRARIES := \
 	liblog \
 	libcutils \
diff --git a/hal/audio_extn/audio_extn.c b/hal/audio_extn/audio_extn.c
index ff485e5..fad793d 100644
--- a/hal/audio_extn/audio_extn.c
+++ b/hal/audio_extn/audio_extn.c
@@ -91,6 +91,17 @@
                                            struct str_parms *parms);
 #endif
 
+#ifndef SOURCE_TRACKING_ENABLED
+#define audio_extn_source_track_set_parameters(adev, parms) (0)
+#define audio_extn_source_track_get_parameters(adev, query, reply) (0)
+#else
+void audio_extn_source_track_set_parameters(struct audio_device *adev,
+                                            struct str_parms *parms);
+void audio_extn_source_track_get_parameters(struct audio_device *adev,
+                                            struct str_parms *query,
+                                            struct str_parms *reply);
+#endif
+
 #ifndef CUSTOM_STEREO_ENABLED
 #define audio_extn_customstereo_set_parameters(adev, parms)         (0)
 #else
@@ -535,6 +546,7 @@
    audio_extn_customstereo_set_parameters(adev, parms);
    audio_extn_hpx_set_parameters(adev, parms);
    audio_extn_pm_set_parameters(parms);
+   audio_extn_source_track_set_parameters(adev, parms);
 }
 
 void audio_extn_get_parameters(const struct audio_device *adev,
@@ -547,6 +559,7 @@
     get_active_offload_usecases(adev, query, reply);
     audio_extn_dts_eagle_get_parameters(adev, query, reply);
     audio_extn_hpx_get_parameters(query, reply);
+    audio_extn_source_track_get_parameters(adev, query, reply);
 
     kv_pairs = str_parms_to_str(reply);
     ALOGD_IF(kv_pairs != NULL, "%s: returns %s", __func__, kv_pairs);
diff --git a/hal/audio_extn/source_track.c b/hal/audio_extn/source_track.c
new file mode 100644
index 0000000..316e52d
--- /dev/null
+++ b/hal/audio_extn/source_track.c
@@ -0,0 +1,640 @@
+/*
+ * Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *   * Neither the name of The Linux Foundation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#define LOG_TAG "source_track"
+/*#define LOG_NDEBUG 0*/
+#define LOG_NDDEBUG 0
+
+#include <errno.h>
+#include <math.h>
+#include <cutils/log.h>
+
+#include "audio_hw.h"
+#include "platform.h"
+#include "platform_api.h"
+#include "voice_extn.h"
+#include <stdlib.h>
+#include <cutils/str_parms.h>
+
+#ifdef SOURCE_TRACKING_ENABLED
+/* Audio Paramater Key to identify the list of start angles.
+ * Starting angle (in degrees) defines the boundary starting angle for each sector.
+ */
+#define AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES        "SoundFocus.start_angles"
+/* Audio Paramater Key to identify the list of enable flags corresponding to each sector.
+ */
+#define AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS      "SoundFocus.enable_sectors"
+/* Audio Paramater Key to identify the gain step value to be applied to all enabled sectors.
+ */
+#define AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP           "SoundFocus.gain_step"
+/* Audio Paramater Key to identify the list of voice activity detector outputs corresponding
+ * to each sector.
+ */
+#define AUDIO_PARAMETER_KEY_SOURCE_TRACK_VAD                "SourceTrack.vad"
+/* Audio Paramater Key to identify the direction (in degrees) of arrival for desired talker
+ * (dominant source of speech).
+ */
+#define AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_SPEECH         "SourceTrack.doa_speech"
+/* Audio Paramater Key to identify the list of directions (in degrees) of arrival for
+ * interferers (interfering noise sources).
+ */
+#define AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_NOISE          "SourceTrack.doa_noise"
+/* Audio Paramater Key to identify the list of sound strength indicators at each degree
+ * of the horizontal plane referred to by a full circle (360 degrees).
+ */
+#define AUDIO_PARAMETER_KEY_SOURCE_TRACK_POLAR_ACTIVITY     "SourceTrack.polar_activity"
+
+#define BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES        0x1
+#define BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS      0x2
+#define BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP           0x4
+#define BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_VAD                0x8
+#define BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_SPEECH         0x10
+#define BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_NOISE          0x20
+#define BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_POLAR_ACTIVITY     0x40
+
+#define BITMASK_AUDIO_PARAMETER_KEYS_SOUND_FOCUS \
+     (BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES |\
+      BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS |\
+      BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP)
+
+#define BITMASK_AUDIO_PARAMETER_KEYS_SOURCE_TRACKING \
+     (BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_VAD |\
+      BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_SPEECH |\
+      BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_NOISE |\
+      BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_POLAR_ACTIVITY)
+
+#define MAX_SECTORS                                         8
+#define MAX_STR_SIZE                                       2048
+
+struct audio_device_to_audio_interface audio_device_to_interface_table[];
+int audio_device_to_interface_table_len;
+
+struct sound_focus_param {
+    uint16_t start_angle[MAX_SECTORS];
+    uint8_t enable[MAX_SECTORS];
+    uint16_t gain_step;
+};
+
+struct source_tracking_param {
+    uint8_t vad[MAX_SECTORS];
+    uint16_t doa_speech;
+    uint16_t doa_noise[3];
+    uint8_t polar_activity[360];
+};
+
+static int add_audio_intf_name_to_mixer_ctl(audio_devices_t device, char *mixer_ctl_name,
+                                struct audio_device_to_audio_interface *table, int len)
+{
+    int ret = 0;
+    int i;
+
+    if (table == NULL) {
+        ALOGE("%s: table is NULL", __func__);
+
+        ret = -EINVAL;
+        goto done;
+    }
+
+    if (mixer_ctl_name == NULL) {
+        ret = -EINVAL;
+        goto done;
+    }
+
+    for (i=0; i < len; i++) {
+        if (device == table[i].device) {
+             strlcat(mixer_ctl_name, " ", MIXER_PATH_MAX_LENGTH);
+             strlcat(mixer_ctl_name, table[i].interface_name, MIXER_PATH_MAX_LENGTH);
+             break;
+        }
+    }
+
+    if (i == len) {
+        ALOGE("%s: Audio Device not found in the table", __func__);
+
+        ret = -EINVAL;
+    }
+done:
+    return ret;
+}
+
+static bool is_stt_supported_snd_device(snd_device_t snd_device)
+{
+    bool ret = false;
+
+    switch (snd_device) {
+    case SND_DEVICE_IN_HANDSET_DMIC:
+    case SND_DEVICE_IN_HANDSET_DMIC_AEC:
+    case SND_DEVICE_IN_HANDSET_DMIC_NS:
+    case SND_DEVICE_IN_HANDSET_DMIC_AEC_NS:
+    case SND_DEVICE_IN_HANDSET_STEREO_DMIC:
+    case SND_DEVICE_IN_HANDSET_QMIC:
+    case SND_DEVICE_IN_VOICE_DMIC:
+    case SND_DEVICE_IN_VOICE_REC_DMIC_FLUENCE:
+    case SND_DEVICE_IN_HEADSET_MIC_FLUENCE:
+    case SND_DEVICE_IN_SPEAKER_DMIC:
+    case SND_DEVICE_IN_SPEAKER_DMIC_AEC:
+    case SND_DEVICE_IN_SPEAKER_DMIC_NS:
+    case SND_DEVICE_IN_SPEAKER_DMIC_AEC_NS:
+    case SND_DEVICE_IN_SPEAKER_DMIC_AEC_NS_BROADSIDE:
+    case SND_DEVICE_IN_SPEAKER_DMIC_AEC_BROADSIDE:
+    case SND_DEVICE_IN_SPEAKER_DMIC_NS_BROADSIDE:
+    case SND_DEVICE_IN_SPEAKER_QMIC_AEC:
+    case SND_DEVICE_IN_SPEAKER_QMIC_NS:
+    case SND_DEVICE_IN_SPEAKER_QMIC_AEC_NS:
+    case SND_DEVICE_IN_VOICE_SPEAKER_DMIC:
+    case SND_DEVICE_IN_VOICE_SPEAKER_DMIC_BROADSIDE:
+    case SND_DEVICE_IN_VOICE_SPEAKER_QMIC:
+        ret = true;
+        break;
+    default:
+        break;
+    }
+
+    return ret;
+}
+
+audio_devices_t get_input_audio_device(audio_devices_t device)
+{
+    audio_devices_t in_device = device;
+
+    switch (device) {
+    case AUDIO_DEVICE_OUT_EARPIECE:
+    case AUDIO_DEVICE_OUT_WIRED_HEADPHONE:
+        in_device = AUDIO_DEVICE_IN_BUILTIN_MIC;
+        break;
+    case AUDIO_DEVICE_OUT_SPEAKER:
+        in_device = AUDIO_DEVICE_IN_BACK_MIC;
+        break;
+    case AUDIO_DEVICE_OUT_WIRED_HEADSET:
+        in_device = AUDIO_DEVICE_IN_WIRED_HEADSET;
+        break;
+    case AUDIO_DEVICE_OUT_BLUETOOTH_SCO_HEADSET:
+        in_device = AUDIO_DEVICE_IN_BLUETOOTH_SCO_HEADSET;
+        break;
+    default:
+        break;
+    }
+
+    return in_device;
+}
+
+static int derive_mixer_ctl_from_usecase_intf(struct audio_device *adev,
+                                              char *mixer_ctl_name) {
+    struct audio_usecase *usecase = NULL;
+    audio_devices_t in_device;
+    int ret = 0;
+
+    if (mixer_ctl_name == NULL) {
+        ALOGE("%s: mixer_ctl_name is NULL", __func__);
+
+        ret = -EINVAL;
+        goto done;
+    }
+
+    if (voice_is_in_call(adev)) {
+        strlcat(mixer_ctl_name, " ", MIXER_PATH_MAX_LENGTH);
+        strlcat(mixer_ctl_name, "Voice Tx", MIXER_PATH_MAX_LENGTH);
+        usecase = get_usecase_from_list(adev,
+                                        get_usecase_id_from_usecase_type(adev, VOICE_CALL));
+    } else if (voice_extn_compress_voip_is_active(adev)) {
+        strlcat(mixer_ctl_name, " ", MIXER_PATH_MAX_LENGTH);
+        strlcat(mixer_ctl_name, "Voice Tx", MIXER_PATH_MAX_LENGTH);
+        usecase = get_usecase_from_list(adev, USECASE_COMPRESS_VOIP_CALL);
+    } else {
+        strlcat(mixer_ctl_name, " ", MIXER_PATH_MAX_LENGTH);
+        strlcat(mixer_ctl_name, "Audio Tx", MIXER_PATH_MAX_LENGTH);
+        usecase = get_usecase_from_list(adev, get_usecase_id_from_usecase_type(adev, PCM_CAPTURE));
+    }
+
+    if (usecase && (usecase->id != USECASE_AUDIO_SPKR_CALIB_TX)) {
+        if (is_stt_supported_snd_device(usecase->in_snd_device)) {
+             in_device = get_input_audio_device(usecase->devices);
+             ret = add_audio_intf_name_to_mixer_ctl(in_device, mixer_ctl_name,
+                audio_device_to_interface_table, audio_device_to_interface_table_len);
+        } else {
+            ALOGE("%s: Sound Focus/Source Tracking not supported on the input sound device (%s)",
+                    __func__, platform_get_snd_device_name(usecase->in_snd_device));
+
+            ret = -EINVAL;
+        }
+    } else {
+        ALOGE("%s: No use case is active which supports Sound Focus/Source Tracking",
+               __func__);
+
+        ret = -EINVAL;
+    }
+
+done:
+    return ret;
+}
+
+static int parse_soundfocus_sourcetracking_keys(struct str_parms *parms)
+{
+    char *str;
+    char *value = NULL;
+    int val, len;
+    int ret = 0, err;
+    char *kv_pairs = str_parms_to_str(parms);
+
+    ALOGV_IF(kv_pairs != NULL, "%s: enter: %s", __func__, kv_pairs);
+
+    len = strlen(kv_pairs);
+    value = (char*)calloc(len, sizeof(char));
+    if(value == NULL) {
+        ret = -ENOMEM;
+        ALOGE("%s: failed to allocate memory", __func__);
+
+        goto done;
+    }
+
+    err = str_parms_get_str(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES,
+                            value, len);
+    if (err >= 0) {
+        str_parms_del(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES);
+        ret = ret | BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES;
+    }
+
+    err = str_parms_get_str(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS,
+                            value, len);
+    if (err >= 0) {
+        str_parms_del(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS);
+        ret = ret | BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS;
+    }
+
+    err = str_parms_get_str(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP,
+                            value, len);
+    if (err >= 0) {
+        str_parms_del(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP);
+        ret = ret | BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP;
+    }
+
+    err = str_parms_get_str(parms, AUDIO_PARAMETER_KEY_SOURCE_TRACK_VAD,
+                            value, len);
+    if (err >= 0) {
+        str_parms_del(parms, AUDIO_PARAMETER_KEY_SOURCE_TRACK_VAD);
+        ret = ret | BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_VAD;
+    }
+
+    err = str_parms_get_str(parms, AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_SPEECH,
+                            value, len);
+    if (err >= 0) {
+        str_parms_del(parms, AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_SPEECH);
+        ret = ret | BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_SPEECH;
+    }
+
+    err = str_parms_get_str(parms, AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_NOISE,
+                            value, len);
+    if (err >= 0) {
+        str_parms_del(parms, AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_NOISE);
+        ret = ret | BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_NOISE;
+    }
+
+    err = str_parms_get_str(parms, AUDIO_PARAMETER_KEY_SOURCE_TRACK_POLAR_ACTIVITY,
+                            value, len);
+    if (err >= 0) {
+        str_parms_del(parms, AUDIO_PARAMETER_KEY_SOURCE_TRACK_POLAR_ACTIVITY);
+        ret = ret | BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_POLAR_ACTIVITY;
+    }
+
+done:
+    free(kv_pairs);
+    if(value != NULL)
+        free(value);
+    ALOGV("%s: returning bitmask = %d", __func__, ret);
+
+    return ret;
+}
+
+static int get_soundfocus_sourcetracking_data(struct audio_device *adev,
+                                        const int bitmask,
+                                        struct sound_focus_param *sound_focus_data,
+                                        struct source_tracking_param *source_tracking_data)
+{
+    struct mixer_ctl *ctl;
+    char sound_focus_mixer_ctl_name[MIXER_PATH_MAX_LENGTH] = "Sound Focus";
+    char source_tracking_mixer_ctl_name[MIXER_PATH_MAX_LENGTH] = "Source Tracking";
+    int ret = -EINVAL;
+    int i, count;
+
+    if (bitmask & BITMASK_AUDIO_PARAMETER_KEYS_SOUND_FOCUS) {
+        /* Derive the mixer control name based on the use case and the audio interface
+         * for the corresponding audio device
+         */
+        ret = derive_mixer_ctl_from_usecase_intf(adev, sound_focus_mixer_ctl_name);
+        if (ret != 0) {
+            ALOGE("%s: Could not get Sound Focus Params", __func__);
+
+            goto done;
+        } else {
+            ALOGV("%s: Mixer Ctl name: %s", __func__, sound_focus_mixer_ctl_name);
+        }
+
+        ctl = mixer_get_ctl_by_name(adev->mixer, sound_focus_mixer_ctl_name);
+        if (!ctl) {
+            ALOGE("%s: Could not get ctl for mixer cmd - %s",
+                  __func__, sound_focus_mixer_ctl_name);
+
+            ret = -EINVAL;
+            goto done;
+        } else {
+            ALOGV("%s: Getting Sound Focus Params", __func__);
+
+            mixer_ctl_update(ctl);
+            count = mixer_ctl_get_num_values(ctl);
+            if (count != sizeof(struct sound_focus_param)) {
+                ALOGE("%s: mixer_ctl_get_num_values() invalid sound focus data size", __func__);
+
+                ret = -EINVAL;
+                goto done;
+            }
+
+            ret = mixer_ctl_get_array(ctl, (void *)sound_focus_data, count);
+            if (ret != 0) {
+                ALOGE("%s: mixer_ctl_get_array() failed to get Sound Focus Params", __func__);
+
+                ret = -EINVAL;
+                goto done;
+            }
+        }
+    }
+
+    if (bitmask & BITMASK_AUDIO_PARAMETER_KEYS_SOURCE_TRACKING) {
+        /* Derive the mixer control name based on the use case and the audio interface
+         * for the corresponding audio device
+         */
+        ret = derive_mixer_ctl_from_usecase_intf(adev, source_tracking_mixer_ctl_name);
+        if (ret != 0) {
+            ALOGE("%s: Could not get Source Tracking Params", __func__);
+
+            goto done;
+        } else {
+            ALOGV("%s: Mixer Ctl name: %s", __func__, source_tracking_mixer_ctl_name);
+        }
+
+        ctl = mixer_get_ctl_by_name(adev->mixer, source_tracking_mixer_ctl_name);
+        if (!ctl) {
+            ALOGE("%s: Could not get ctl for mixer cmd - %s",
+                  __func__, source_tracking_mixer_ctl_name);
+
+            ret = -EINVAL;
+            goto done;
+        } else {
+            ALOGV("%s: Getting Source Tracking Params", __func__);
+
+            mixer_ctl_update(ctl);
+            count = mixer_ctl_get_num_values(ctl);
+            if (count != sizeof(struct source_tracking_param)) {
+                ALOGE("%s: mixer_ctl_get_num_values() invalid source tracking data size", __func__);
+
+                ret = -EINVAL;
+                goto done;
+            }
+
+            ret = mixer_ctl_get_array(ctl, (void *)source_tracking_data, count);
+            if (ret != 0) {
+                ALOGE("%s: mixer_ctl_get_array() failed to get Source Tracking Params", __func__);
+
+                ret = -EINVAL;
+                goto done;
+            }
+        }
+    }
+
+done:
+    return ret;
+}
+
+static void send_soundfocus_sourcetracking_params(struct str_parms *reply,
+                                                const int bitmask,
+                                                const struct sound_focus_param sound_focus_data,
+                                                const struct source_tracking_param source_tracking_data)
+{
+    int i = 0, len = 0;
+    char value[MAX_STR_SIZE] = "";
+
+    if (bitmask & BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES) {
+        for (i = 0; i < MAX_SECTORS; i++) {
+            if ((i >=4) && (sound_focus_data.start_angle[i] == 0xFFFF))
+                continue;
+            if (i)
+                snprintf(value + strlen(value), MAX_STR_SIZE, ",");
+            snprintf(value + strlen(value), MAX_STR_SIZE, "%d", sound_focus_data.start_angle[i]);
+        }
+        str_parms_add_str(reply, AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES, value);
+    }
+
+    strlcpy(value, "", sizeof(""));
+    if (bitmask & BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS) {
+        for (i = 0; i < MAX_SECTORS; i++) {
+            if ((i >=4) && (sound_focus_data.enable[i] == 0xFF))
+                continue;
+            if (i)
+                snprintf(value + strlen(value), MAX_STR_SIZE, ",");
+            snprintf(value + strlen(value), MAX_STR_SIZE, "%d", sound_focus_data.enable[i]);
+        }
+        str_parms_add_str(reply, AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS, value);
+    }
+
+    if (bitmask & BITMASK_AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP)
+        str_parms_add_int(reply, AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP, sound_focus_data.gain_step);
+
+    strlcpy(value, "", sizeof(""));
+    if (bitmask & BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_VAD) {
+        for (i = 0; i < MAX_SECTORS; i++) {
+            if ((i >=4) && (source_tracking_data.vad[i] == 0xFF))
+                continue;
+            if (i)
+                snprintf(value + strlen(value), MAX_STR_SIZE, ",");
+            snprintf(value + strlen(value), MAX_STR_SIZE, "%d", source_tracking_data.vad[i]);
+        }
+        str_parms_add_str(reply, AUDIO_PARAMETER_KEY_SOURCE_TRACK_VAD, value);
+    }
+
+    if (bitmask & BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_SPEECH)
+        str_parms_add_int(reply, AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_SPEECH, source_tracking_data.doa_speech);
+
+    strlcpy(value, "", sizeof(""));
+    if (bitmask & BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_NOISE) {
+        snprintf(value, MAX_STR_SIZE,
+                     "%d,%d,%d", source_tracking_data.doa_noise[0], source_tracking_data.doa_noise[1], source_tracking_data.doa_noise[2]);
+        str_parms_add_str(reply, AUDIO_PARAMETER_KEY_SOURCE_TRACK_DOA_NOISE, value);
+    }
+
+    strlcpy(value, "", sizeof(""));
+    if (bitmask & BITMASK_AUDIO_PARAMETER_KEY_SOURCE_TRACK_POLAR_ACTIVITY) {
+        for (i = 0; i < 360; i++) {
+            if (i)
+                snprintf(value + strlen(value), MAX_STR_SIZE, ",");
+            snprintf(value + strlen(value), MAX_STR_SIZE, "%d", source_tracking_data.polar_activity[i]);
+        }
+        str_parms_add_str(reply, AUDIO_PARAMETER_KEY_SOURCE_TRACK_POLAR_ACTIVITY, value);
+    }
+}
+
+void audio_extn_source_track_get_parameters(struct audio_device *adev,
+                                            struct str_parms *query,
+                                            struct str_parms *reply)
+{
+    int bitmask = 0, ret = 0;
+    struct sound_focus_param sound_focus_data;
+    struct source_tracking_param source_tracking_data;
+
+    memset(&sound_focus_data, 0xFF, sizeof(struct sound_focus_param));
+    memset(&source_tracking_data, 0xFF, sizeof(struct source_tracking_param));
+
+    // Parse the input parameters string for Source Tracking keys
+    bitmask = parse_soundfocus_sourcetracking_keys(query);
+    if (bitmask) {
+        // Get the parameter values from the backend
+        ret = get_soundfocus_sourcetracking_data(adev, bitmask, &sound_focus_data, &source_tracking_data);
+        if (ret == 0) {
+            // Construct the return string with key, value pairs
+            send_soundfocus_sourcetracking_params(reply, bitmask, sound_focus_data, source_tracking_data);
+        }
+    }
+}
+
+void audio_extn_source_track_set_parameters(struct audio_device *adev,
+                                            struct str_parms *parms)
+{
+    int len, ret, count;;
+    struct mixer_ctl *ctl;
+    char sound_focus_mixer_ctl_name[MIXER_PATH_MAX_LENGTH] = "Sound Focus";
+    char *value = NULL;
+    char *kv_pairs = str_parms_to_str(parms);
+
+    len = strlen(kv_pairs);
+    value = (char*)calloc(len, sizeof(char));
+    if(value == NULL) {
+        ret = -ENOMEM;
+        ALOGE("%s: failed to allocate memory", __func__);
+
+        goto done;
+    }
+
+    // Parse the input parameter string for Source Tracking key, value pairs
+    ret = str_parms_get_str(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES,
+                            value, len);
+    if (ret >= 0) {
+        char *saveptr, *tok;
+        int i = 0, val;
+        struct sound_focus_param sound_focus_param;
+
+        memset(&sound_focus_param, 0xFF, sizeof(struct sound_focus_param));
+
+        str_parms_del(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_START_ANGLES);
+        tok = strtok_r(value, ",", &saveptr);
+        while ((i < MAX_SECTORS) && (tok != NULL)) {
+            if (sscanf(tok, "%d", &val) == 1) {
+                sound_focus_param.start_angle[i++] = (uint16_t)val;
+            }
+            tok = strtok_r(NULL, ",", &saveptr);
+        }
+
+        ret = str_parms_get_str(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS,
+                                value, len);
+        if (ret >= 0) {
+            str_parms_del(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_ENABLE_SECTORS);
+            tok = strtok_r(value, ",", &saveptr);
+            i = 0;
+            while ((i < MAX_SECTORS) && (tok != NULL)) {
+                if (sscanf(tok, "%d", &val) == 1) {
+                    sound_focus_param.enable[i++] = (uint8_t)val;
+                }
+                tok = strtok_r(NULL, ",", &saveptr);
+            }
+        } else {
+            ALOGE("%s: SoundFocus.enable_sectors key not found", __func__);
+
+            goto done;
+        }
+
+        ret = str_parms_get_int(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP, &val);
+        if (ret >= 0) {
+            str_parms_del(parms, AUDIO_PARAMETER_KEY_SOUND_FOCUS_GAIN_STEP);
+            sound_focus_param.gain_step = (uint16_t)val;
+        } else {
+            ALOGE("%s: SoundFocus.gain_step key not found", __func__);
+
+            goto done;
+        }
+
+        /* Derive the mixer control name based on the use case and the audio h/w
+         * interface name for the corresponding audio device
+         */
+        ret = derive_mixer_ctl_from_usecase_intf(adev, sound_focus_mixer_ctl_name);
+        if (ret != 0) {
+            ALOGE("%s: Could not set Sound Focus Params", __func__);
+
+            goto done;
+        } else {
+            ALOGV("%s: Mixer Ctl name: %s", __func__, sound_focus_mixer_ctl_name);
+        }
+
+        ctl = mixer_get_ctl_by_name(adev->mixer, sound_focus_mixer_ctl_name);
+        if (!ctl) {
+            ALOGE("%s: Could not get ctl for mixer cmd - %s",
+                  __func__, sound_focus_mixer_ctl_name);
+
+            goto done;
+        } else {
+            ALOGV("%s: Setting Sound Focus Params", __func__);
+
+            for (i = 0; i < MAX_SECTORS;i++) {
+                ALOGV("%s: start_angles[%d] = %d", __func__, i, sound_focus_param.start_angle[i]);
+            }
+            for (i = 0; i < MAX_SECTORS;i++) {
+                ALOGV("%s: enable_sectors[%d] = %d", __func__, i, sound_focus_param.enable[i]);
+            }
+            ALOGV("%s: gain_step = %d", __func__, sound_focus_param.gain_step);
+
+            mixer_ctl_update(ctl);
+            count = mixer_ctl_get_num_values(ctl);
+            if (count != sizeof(struct sound_focus_param)) {
+                ALOGE("%s: mixer_ctl_get_num_values() invalid data size", __func__);
+
+                goto done;
+            }
+
+            // Set the parameters on the mixer control derived above
+            ret = mixer_ctl_set_array(ctl, (void *)&sound_focus_param, count);
+            if (ret != 0) {
+                ALOGE("%s: mixer_ctl_set_array() failed to set Sound Focus Params", __func__);
+
+                goto done;
+            }
+       }
+    }
+
+done:
+    free(kv_pairs);
+    if(value != NULL)
+        free(value);
+    return;
+}
+#endif /* SOURCE_TRACKING_ENABLED end */
diff --git a/hal/audio_hw.c b/hal/audio_hw.c
index 038c8e7..24852b6 100644
--- a/hal/audio_hw.c
+++ b/hal/audio_hw.c
@@ -731,14 +731,15 @@
     return ret;
 }
 
-static audio_usecase_t get_voice_usecase_id_from_list(struct audio_device *adev)
+audio_usecase_t get_usecase_id_from_usecase_type(struct audio_device *adev,
+                                                 usecase_type_t type)
 {
     struct audio_usecase *usecase;
     struct listnode *node;
 
     list_for_each(node, &adev->usecase_list) {
         usecase = node_to_item(node, struct audio_usecase, list);
-        if (usecase->type == VOICE_CALL) {
+        if (usecase->type == type) {
             ALOGV("%s: usecase id %d", __func__, usecase->id);
             return usecase->id;
         }
@@ -795,7 +796,7 @@
          */
         if (voice_is_in_call(adev) && adev->mode == AUDIO_MODE_IN_CALL) {
             vc_usecase = get_usecase_from_list(adev,
-                                               get_voice_usecase_id_from_list(adev));
+                                               get_usecase_id_from_usecase_type(adev, VOICE_CALL));
             if ((vc_usecase) && ((vc_usecase->devices & AUDIO_DEVICE_OUT_ALL_CODEC_BACKEND) ||
                 (usecase->devices == AUDIO_DEVICE_IN_VOICE_CALL))) {
                 in_snd_device = vc_usecase->in_snd_device;
diff --git a/hal/audio_hw.h b/hal/audio_hw.h
index d0e01e5..2c55755 100644
--- a/hal/audio_hw.h
+++ b/hal/audio_hw.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
  * Not a contribution.
  *
  * Copyright (C) 2013 The Android Open Source Project
@@ -342,6 +342,8 @@
 int pcm_ioctl(struct pcm *pcm, int request, ...);
 
 int get_snd_card_state(struct audio_device *adev);
+audio_usecase_t get_usecase_id_from_usecase_type(struct audio_device *adev,
+                                                 usecase_type_t type);
 
 #define LITERAL_TO_STRING(x) #x
 #define CHECK(condition) LOG_ALWAYS_FATAL_IF(!(condition), "%s",\
diff --git a/hal/msm8916/platform.c b/hal/msm8916/platform.c
old mode 100755
new mode 100644
index d04513d..c23ee09
--- a/hal/msm8916/platform.c
+++ b/hal/msm8916/platform.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
  * Not a Contribution.
  *
  * Copyright (C) 2013 The Android Open Source Project
@@ -2767,3 +2767,9 @@
     strlcpy(buf, PLATFORM_IMAGE_NAME, sizeof(PLATFORM_IMAGE_NAME));
     return 0;
 }
+
+int platform_set_audio_device_interface(const char * device_name __unused,
+                                        const char *intf_name __unused)
+{
+    return -ENOSYS;
+}
diff --git a/hal/msm8960/platform.c b/hal/msm8960/platform.c
index 4c798b6..bbfa042 100644
--- a/hal/msm8960/platform.c
+++ b/hal/msm8960/platform.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
  * Not a contribution.
  *
  * Copyright (C) 2013 The Android Open Source Project
@@ -1153,3 +1153,9 @@
 {
     return 0;
 }
+
+int platform_set_audio_device_interface(const char * device_name __unused,
+                                        const char *intf_name __unused)
+{
+    return -ENOSYS;
+}
diff --git a/hal/msm8974/platform.c b/hal/msm8974/platform.c
old mode 100755
new mode 100644
index 05953fb..635bcb7
--- a/hal/msm8974/platform.c
+++ b/hal/msm8974/platform.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
  * Not a Contribution.
  *
  * Copyright (C) 2013 The Android Open Source Project
@@ -3648,3 +3648,54 @@
 end:
     return ret;
 }
+
+/*
+ * This is a lookup table to map android audio input device to audio h/w interface (backend).
+ * The table can be extended for other input devices by adding appropriate entries.
+ * Also the audio interface for a particular input device can be overriden by adding
+ * corresponding entry in audio_platform_info.xml file.
+ */
+struct audio_device_to_audio_interface audio_device_to_interface_table[] = {
+    {AUDIO_DEVICE_IN_BUILTIN_MIC, ENUM_TO_STRING(AUDIO_DEVICE_IN_BUILTIN_MIC), "SLIMBUS_0"},
+    {AUDIO_DEVICE_IN_BACK_MIC, ENUM_TO_STRING(AUDIO_DEVICE_IN_BACK_MIC), "SLIMBUS_0"},
+};
+
+int audio_device_to_interface_table_len  =
+    sizeof(audio_device_to_interface_table) / sizeof(audio_device_to_interface_table[0]);
+
+int platform_set_audio_device_interface(const char *device_name, const char *intf_name)
+{
+    int ret = 0;
+    int i;
+
+    if (device_name == NULL || intf_name == NULL) {
+        ALOGE("%s: Invalid input", __func__);
+
+        ret = -EINVAL;
+        goto done;
+    }
+
+    ALOGD("%s: Enter, device name:%s, intf name:%s", __func__, device_name, intf_name);
+
+    size_t device_name_len = strlen(device_name);
+    for (i = 0; i < audio_device_to_interface_table_len; i++) {
+        char* name = audio_device_to_interface_table[i].device_name;
+        size_t name_len = strlen(name);
+        if ((name_len == device_name_len) &&
+            (strncmp(device_name, name, name_len) == 0)) {
+            ALOGD("%s: Matched device name:%s, overwrite intf name with %s",
+                  __func__, device_name, intf_name);
+
+            strlcpy(audio_device_to_interface_table[i].interface_name, intf_name,
+                    sizeof(audio_device_to_interface_table[i].interface_name));
+            goto done;
+        }
+    }
+    ALOGE("%s: Could not find matching device name %s",
+            __func__, device_name);
+
+    ret = -EINVAL;
+
+done:
+    return ret;
+}
diff --git a/hal/msm8974/platform.h b/hal/msm8974/platform.h
index c7d7f0e..552dd41 100644
--- a/hal/msm8974/platform.h
+++ b/hal/msm8974/platform.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
  * Not a Contribution.
  *
  * Copyright (C) 2013 The Android Open Source Project
@@ -360,4 +360,12 @@
  */
 #define DEVICE_PARAM_MUTE_ID    0
 #define DEVICE_PARAM_LATENCY_ID 1
+
+#define ENUM_TO_STRING(X) #X
+
+struct audio_device_to_audio_interface {
+    audio_devices_t device;
+    char device_name[100];
+    char interface_name[100];
+};
 #endif // QCOM_AUDIO_PLATFORM_H
diff --git a/hal/platform_api.h b/hal/platform_api.h
index 3e81d68..3808b14 100644
--- a/hal/platform_api.h
+++ b/hal/platform_api.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013-2015, The Linux Foundation. All rights reserved.
  * Not a contribution.
  *
  * Copyright (C) 2013 The Android Open Source Project
@@ -109,4 +109,5 @@
 void platform_invalidate_edid(void * platform);
 int platform_set_hdmi_config(struct stream_out *out);
 int platform_set_device_params(struct stream_out *out, int param, int value);
+int platform_set_audio_device_interface(const char * device_name, const char *intf_name);
 #endif // AUDIO_PLATFORM_API_H
diff --git a/hal/platform_info.c b/hal/platform_info.c
index a176177..13a314e 100644
--- a/hal/platform_info.c
+++ b/hal/platform_info.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014-2015, The Linux Foundation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ -46,6 +46,7 @@
     BITWIDTH,
     PCM_ID,
     BACKEND_NAME,
+    INTERFACE_NAME,
 } section_t;
 
 typedef void (* section_process_fn)(const XML_Char **attr);
@@ -54,6 +55,7 @@
 static void process_bit_width(const XML_Char **attr);
 static void process_pcm_id(const XML_Char **attr);
 static void process_backend_name(const XML_Char **attr);
+static void process_interface_name(const XML_Char **attr);
 static void process_root(const XML_Char **attr);
 
 static section_process_fn section_table[] = {
@@ -62,6 +64,7 @@
     [BITWIDTH] = process_bit_width,
     [PCM_ID] = process_pcm_id,
     [BACKEND_NAME] = process_backend_name,
+    [INTERFACE_NAME] = process_interface_name,
 };
 
 static section_t section;
@@ -83,6 +86,11 @@
  * ...
  * ...
  * </pcm_ids>
+ * <interface_names>
+ * <device name="Use audio device name here, not sound device name" interface="PRIMARY_I2S"/>
+ * ...
+ * ...
+ * </interface_names>
  * </audio_platform_info>
  */
 
@@ -237,6 +245,34 @@
     return;
 }
 
+static void process_interface_name(const XML_Char **attr)
+{
+    int ret;
+
+    if (strcmp(attr[0], "name") != 0) {
+        ALOGE("%s: 'name' not found, no Audio Interface set!", __func__);
+
+        goto done;
+    }
+
+    if (strcmp(attr[2], "interface") != 0) {
+        ALOGE("%s: Device %s has no Audio Interface set!",
+              __func__, attr[1]);
+
+        goto done;
+    }
+
+    ret = platform_set_audio_device_interface((char *)attr[1], (char *)attr[3]);
+    if (ret < 0) {
+        ALOGE("%s: Audio Interface not set!", __func__);
+
+        goto done;
+    }
+
+done:
+    return;
+}
+
 static void start_tag(void *userdata __unused, const XML_Char *tag_name,
                       const XML_Char **attr)
 {
@@ -252,9 +288,12 @@
         section = PCM_ID;
     } else if (strcmp(tag_name, "backend_names") == 0) {
         section = BACKEND_NAME;
+    } else if (strcmp(tag_name, "interface_names") == 0) {
+        section = INTERFACE_NAME;
     } else if (strcmp(tag_name, "device") == 0) {
-        if ((section != ACDB) && (section != BACKEND_NAME) && (section != BITWIDTH)) {
-            ALOGE("device tag only supported for acdb/backend names");
+        if ((section != ACDB) && (section != BACKEND_NAME) && (section != BITWIDTH) &&
+            (section != INTERFACE_NAME)) {
+            ALOGE("device tag only supported for acdb/backend names/bitwitdh/interface names");
             return;
         }
 
@@ -284,6 +323,8 @@
         section = ROOT;
     } else if (strcmp(tag_name, "backend_names") == 0) {
         section = ROOT;
+    } else if (strcmp(tag_name, "interface_names") == 0) {
+        section = ROOT;
     }
 }