diff --git a/hal/Android.mk b/hal/Android.mk
index 2aa7f12..c344898 100644
--- a/hal/Android.mk
+++ b/hal/Android.mk
@@ -215,6 +215,11 @@
   LOCAL_CFLAGS += -DBG_CODEC_CAL
 endif
 
+ifeq ($(strip $(AUDIO_FEATURE_ENABLED_CIRRUS_SPKR_PROTECTION)),true)
+    LOCAL_CFLAGS += -DSPKR_PROT_ENABLED
+    LOCAL_SRC_FILES += audio_extn/cirrus_playback.c
+endif
+
 ifdef MULTIPLE_HW_VARIANTS_ENABLED
   LOCAL_CFLAGS += -DHW_VARIANTS_ENABLED
   LOCAL_SRC_FILES += $(AUDIO_PLATFORM)/hw_info.c
diff --git a/hal/audio_extn/cirrus_playback.c b/hal/audio_extn/cirrus_playback.c
new file mode 100644
index 0000000..c93e2e8
--- /dev/null
+++ b/hal/audio_extn/cirrus_playback.c
@@ -0,0 +1,539 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "audio_hw_cirrus_playback"
+/*#define LOG_NDEBUG 0*/
+
+#include <errno.h>
+#include <math.h>
+#include <cutils/log.h>
+#include <fcntl.h>
+#include "../audio_hw.h"
+#include "platform.h"
+#include "platform_api.h"
+#include <sys/stat.h>
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <dlfcn.h>
+#include <math.h>
+#include <time.h>
+#include <unistd.h>
+#include <cutils/properties.h>
+#include "audio_extn.h"
+
+struct cirrus_playback_session {
+    void *adev_handle;
+    pthread_mutex_t mutex_fb_prot;
+    pthread_mutex_t mutex_pcm_stream;
+    pthread_t pcm_stream_thread;
+    struct pcm *pcm_rx;
+    struct pcm *pcm_tx;
+    bool spkr_prot_enable;
+};
+
+struct crus_sp_ioctl_header {
+    uint32_t size;
+    uint32_t module_id;
+    uint32_t param_id;
+    uint32_t data_length;
+    void *data;
+};
+
+/* Payload struct for getting calibration result from DSP module */
+struct cirrus_cal_result_t {
+    int32_t status_l;
+    int32_t checksum_l;
+    int32_t z_l;
+    int32_t status_r;
+    int32_t checksum_r;
+    int32_t z_r;
+    int32_t atemp;
+};
+
+/* Payload struct for setting the RX and TX use cases */
+struct crus_rx_run_case_ctrl_t {
+    int32_t value;
+    int32_t status_l;
+    int32_t checksum_l;
+    int32_t z_l;
+    int32_t status_r;
+    int32_t checksum_r;
+    int32_t z_r;
+    int32_t atemp;
+};
+
+#define CRUS_SP_FILE "/dev/msm_cirrus_playback"
+#define CRUS_CAL_FILE "/persist/audio/audio.cal"
+#define CRUS_SP_USECASE_MIXER "Cirrus SP Usecase Config"
+#define CRUS_SP_EXT_CONFIG_MIXER "Cirrus SP EXT Config"
+
+#define CIRRUS_SP 0x10027053
+
+#define CRUS_MODULE_ID_TX 0x00000002
+#define CRUS_MODULE_ID_RX 0x00000001
+
+#define CRUS_PARAM_RX_SET_USECASE 0x00A1AF02
+#define CRUS_PARAM_TX_SET_USECASE 0x00A1BF0A
+
+#define CRUS_PARAM_RX_SET_CALIB 0x00A1AF03
+#define CRUS_PARAM_TX_SET_CALIB 0x00A1BF03
+
+#define CRUS_PARAM_RX_SET_EXT_CONFIG 0x00A1AF05
+#define CRUS_PARAM_TX_SET_EXT_CONFIG 0x00A1BF08
+
+#define CRUS_PARAM_RX_GET_TEMP 0x00A1AF07
+#define CRUS_PARAM_TX_GET_TEMP_CAL 0x00A1BF06
+// variables based on CSPL tuning file, max parameter length is 96 integers (384 bytes)
+#define CRUS_PARAM_TEMP_MAX_LENGTH 384
+
+#define CRUS_AFE_PARAM_ID_ENABLE 0x00010203
+
+#define CRUS_SP_IOCTL_MAGIC 'a'
+
+#define CRUS_SP_IOCTL_GET _IOWR(CRUS_SP_IOCTL_MAGIC, 219, void *)
+#define CRUS_SP_IOCTL_SET _IOWR(CRUS_SP_IOCTL_MAGIC, 220, void *)
+#define CRUS_SP_IOCTL_GET_CALIB _IOWR(CRUS_SP_IOCTL_MAGIC, 221, void *)
+#define CRUS_SP_IOCTL_SET_CALIB _IOWR(CRUS_SP_IOCTL_MAGIC, 222, void *)
+
+#define CRUS_SP_DEFAULT_AMBIENT_TEMP 23
+
+static struct pcm_config pcm_config_cirrus_tx = {
+    .channels = 2,
+    .rate = 48000,
+    .period_size = 320,
+    .period_count = 4,
+    .format = PCM_FORMAT_S16_LE,
+    .start_threshold = 0,
+    .stop_threshold = INT_MAX,
+    .avail_min = 0,
+};
+
+static struct pcm_config pcm_config_cirrus_rx = {
+    .channels = 2,
+    .rate = 48000,
+    .period_size = 320,
+    .period_count = 4,
+    .format = PCM_FORMAT_S16_LE,
+    .start_threshold = 0,
+    .stop_threshold = INT_MAX,
+    .avail_min = 0,
+};
+
+static struct cirrus_playback_session handle;
+
+static void *audio_extn_cirrus_run_calibration() {
+    struct audio_device *adev = handle.adev_handle;
+    struct crus_sp_ioctl_header header;
+    struct cirrus_cal_result_t result;
+    struct mixer_ctl *ctl;
+    FILE *cal_file;
+    int ret = 0, dev_file;
+    char *buffer = NULL;
+    uint32_t option = 1;
+    struct timespec timeout;
+
+    ALOGI("%s: Calibration thread", __func__);
+
+    timeout.tv_sec = 10;
+    timeout.tv_nsec = 0;
+
+    dev_file = open(CRUS_SP_FILE, O_RDWR | O_NONBLOCK);
+    if (dev_file < 0) {
+        ALOGE("%s: Failed to open Cirrus Playback IOCTL (%d)",
+              __func__, dev_file);
+        ret = -EINVAL;
+        goto exit;
+    }
+
+    buffer = calloc(1, CRUS_PARAM_TEMP_MAX_LENGTH);
+    if (!buffer) {
+        ret = -EINVAL;
+        goto exit;
+    }
+
+    cal_file = fopen(CRUS_CAL_FILE, "r");
+    if (cal_file) {
+        size_t bytes;
+        bytes = fread(&result, 1, sizeof(result), cal_file);
+        if (bytes < sizeof(result)) {
+            ALOGE("%s: Cirrus SP calibration file cannot be read (%d)",
+                  __func__, ret);
+            ret = -EINVAL;
+            fclose(cal_file);
+            goto exit;
+        }
+
+        fclose(cal_file);
+    } else {
+
+        ALOGV("%s: Calibrating...", __func__);
+
+        header.size = sizeof(header);
+        header.module_id = CRUS_MODULE_ID_RX;
+        header.param_id = CRUS_PARAM_RX_SET_CALIB;
+        header.data_length = sizeof(option);
+        header.data = &option;
+
+        ret = ioctl(dev_file, CRUS_SP_IOCTL_SET, &header);
+        if (ret < 0) {
+            ALOGE("%s: Cirrus SP calibration IOCTL failure (%d)",
+                  __func__, ret);
+            ret = -EINVAL;
+            goto exit;
+        }
+
+        header.size = sizeof(header);
+        header.module_id = CRUS_MODULE_ID_TX;
+        header.param_id = CRUS_PARAM_TX_SET_CALIB;
+        header.data_length = sizeof(option);
+        header.data = &option;
+
+        ret = ioctl(dev_file, CRUS_SP_IOCTL_SET, &header);
+        if (ret < 0) {
+            ALOGE("%s: Cirrus SP calibration IOCTL failure (%d)",
+                  __func__, ret);
+            ret = -EINVAL;
+            goto exit;
+        }
+
+        sleep(2);
+
+        header.size = sizeof(header);
+        header.module_id = CRUS_MODULE_ID_TX;
+        header.param_id = CRUS_PARAM_TX_GET_TEMP_CAL;
+        header.data_length = sizeof(result);
+        header.data = &result;
+
+        ret = ioctl(dev_file, CRUS_SP_IOCTL_GET, &header);
+        if (ret < 0) {
+            ALOGE("%s: Cirrus SP calibration IOCTL failure (%d)",
+                  __func__, ret);
+            ret = -EINVAL;
+            goto exit;
+        }
+
+        result.atemp = CRUS_SP_DEFAULT_AMBIENT_TEMP;
+
+        // TODO: Save calibrated data to file
+    }
+
+    header.size = sizeof(header);
+    header.module_id = CRUS_MODULE_ID_TX;
+    header.param_id = 0;
+    header.data_length = sizeof(result);
+    header.data = &result;
+
+    ret = ioctl(dev_file, CRUS_SP_IOCTL_SET_CALIB, &header);
+
+    if (ret < 0) {
+        ALOGE("%s: Cirrus SP calibration IOCTL failure (%d)", __func__, ret);
+        close(dev_file);
+        ret = -EINVAL;
+        goto exit;
+    }
+
+    ctl = mixer_get_ctl_by_name(adev->mixer,
+                                CRUS_SP_USECASE_MIXER);
+    if (!ctl) {
+        ALOGE("%s: Could not get ctl for mixer cmd - %s",
+              __func__, CRUS_SP_USECASE_MIXER);
+        ret = -EINVAL;
+        goto exit;
+    }
+
+    mixer_ctl_set_value(ctl, 0, 0); // Set RX external firmware config
+
+    sleep(1);
+
+    header.size = sizeof(header);
+    header.module_id = CRUS_MODULE_ID_RX;
+    header.param_id = CRUS_PARAM_RX_GET_TEMP;
+    header.data_length = sizeof(buffer);
+    header.data = buffer;
+
+    ret = ioctl(dev_file, CRUS_SP_IOCTL_GET, &header);
+    if (ret < 0) {
+        ALOGE("%s: Cirrus SP temperature IOCTL failure (%d)", __func__, ret);
+        ret = -EINVAL;
+        goto exit;
+    }
+
+    ALOGI("%s: Cirrus SP successfully calibrated", __func__);
+
+exit:
+    close(dev_file);
+    free(buffer);
+    ALOGV("%s: Exit", __func__);
+
+    return NULL;
+}
+
+
+static void *audio_extn_cirrus_pcm_stream_thread() {
+    struct audio_device *adev = handle.adev_handle;
+    struct audio_usecase *uc_info_rx = NULL;
+    int ret = 0;
+    int32_t pcm_dev_rx_id = 0;
+    uint32_t rx_use_case = USECASE_AUDIO_PLAYBACK_DEEP_BUFFER;
+    uint32_t retries = 5;
+
+    pthread_mutex_lock(&handle.mutex_pcm_stream);
+
+    ALOGI("%s: PCM Stream thread", __func__);
+
+    while (!adev->platform && retries) {
+        sleep(1);
+        ALOGI("%s: Waiting...", __func__);
+        retries--;
+    }
+
+    uc_info_rx = (struct audio_usecase *)calloc(1, sizeof(*uc_info_rx));
+    if (!uc_info_rx) {
+        ret = -EINVAL;
+        goto exit;
+    }
+
+    uc_info_rx->id = rx_use_case;
+    uc_info_rx->type = PCM_PLAYBACK;
+    uc_info_rx->in_snd_device = SND_DEVICE_NONE;
+    uc_info_rx->stream.out = adev->primary_output;
+    uc_info_rx->out_snd_device = SND_DEVICE_OUT_SPEAKER;
+    list_add_tail(&adev->usecase_list, &uc_info_rx->list);
+
+    enable_snd_device(adev, SND_DEVICE_OUT_SPEAKER);
+    enable_audio_route(adev, uc_info_rx);
+    handle.pcm_rx = pcm_open(adev->snd_card, pcm_dev_rx_id,
+                             PCM_OUT, &pcm_config_cirrus_rx);
+
+    if (!handle.pcm_rx || !pcm_is_ready(handle.pcm_rx)) {
+        ALOGE("%s: PCM device not ready: %s", __func__,
+              pcm_get_error(handle.pcm_rx ? handle.pcm_rx : 0));
+        ret = -EINVAL;
+        goto close_stream;
+    }
+
+    if (pcm_start(handle.pcm_rx) < 0) {
+        ALOGE("%s: pcm start for RX failed; error = %s", __func__,
+              pcm_get_error(handle.pcm_rx));
+        ret = -EINVAL;
+        goto close_stream;
+    }
+
+    ALOGV("%s: PCM thread streaming", __func__);
+
+    audio_extn_cirrus_run_calibration();
+
+close_stream:
+    if (handle.pcm_rx) {
+        ALOGV("%s: pcm_rx_close", __func__);
+        pcm_close(handle.pcm_rx);
+        handle.pcm_rx = NULL;
+    }
+
+    disable_audio_route(adev, uc_info_rx);
+    disable_snd_device(adev, SND_DEVICE_OUT_SPEAKER);
+    list_remove(&uc_info_rx->list);
+    free(uc_info_rx);
+
+exit:
+    pthread_mutex_unlock(&handle.mutex_pcm_stream);
+    ALOGV("%s: Exit", __func__);
+
+    pthread_exit(0);
+    return NULL;
+}
+
+void audio_extn_spkr_prot_init(void *adev) {
+    ALOGI("%s: Initialize Cirrus Logic Playback module", __func__);
+
+    struct snd_card_split *snd_split_handle = NULL;
+
+    if (!adev) {
+        ALOGE("%s: Invalid params", __func__);
+        return;
+    }
+
+    memset(&handle, 0, sizeof(handle));
+
+    snd_split_handle = audio_extn_get_snd_card_split();
+
+    /* FIXME: REMOVE THIS AFTER B1C1 P1.0 SUPPORT */
+    if (!strcmp(snd_split_handle->form_factor, "tdm")) {
+        handle.spkr_prot_enable = true;
+    } else {
+        handle.spkr_prot_enable = false;
+    }
+
+    handle.adev_handle = adev;
+
+    pthread_mutex_init(&handle.mutex_fb_prot, NULL);
+    pthread_mutex_init(&handle.mutex_pcm_stream, NULL);
+
+    (void)pthread_create(&handle.pcm_stream_thread,
+                         (const pthread_attr_t *) NULL,
+                         audio_extn_cirrus_pcm_stream_thread, &handle);
+}
+
+int audio_extn_spkr_prot_start_processing(snd_device_t snd_device) {
+    struct audio_usecase *uc_info_tx;
+    struct audio_device *adev = handle.adev_handle;
+    int32_t pcm_dev_tx_id = -1, ret = 0;
+
+    ALOGV("%s: Entry", __func__);
+
+    if (!adev) {
+        ALOGE("%s: Invalid params", __func__);
+        return -EINVAL;
+    }
+
+    uc_info_tx = (struct audio_usecase *)calloc(1, sizeof(*uc_info_tx));
+    if (!uc_info_tx) {
+        return -ENOMEM;
+    }
+
+    audio_route_apply_and_update_path(adev->audio_route,
+                                      platform_get_snd_device_name(snd_device));
+
+    pthread_mutex_lock(&handle.mutex_fb_prot);
+    uc_info_tx->id = USECASE_AUDIO_SPKR_CALIB_TX;
+    uc_info_tx->type = PCM_CAPTURE;
+    uc_info_tx->in_snd_device = SND_DEVICE_IN_CAPTURE_VI_FEEDBACK;
+    uc_info_tx->out_snd_device = SND_DEVICE_NONE;
+    handle.pcm_tx = NULL;
+
+    list_add_tail(&adev->usecase_list, &uc_info_tx->list);
+
+    enable_snd_device(adev, SND_DEVICE_IN_CAPTURE_VI_FEEDBACK);
+    enable_audio_route(adev, uc_info_tx);
+
+    pcm_dev_tx_id = platform_get_pcm_device_id(uc_info_tx->id, PCM_CAPTURE);
+
+    if (pcm_dev_tx_id < 0) {
+        ALOGE("%s: Invalid pcm device for usecase (%d)",
+              __func__, uc_info_tx->id);
+        ret = -ENODEV;
+        goto exit;
+    }
+
+    handle.pcm_tx = pcm_open(adev->snd_card,
+                             pcm_dev_tx_id,
+                             PCM_IN, &pcm_config_cirrus_tx);
+
+    if (!handle.pcm_tx || !pcm_is_ready(handle.pcm_tx)) {
+        ALOGD("%s: PCM device not ready: %s", __func__,
+              pcm_get_error(handle.pcm_tx ? handle.pcm_tx : 0));
+        ret = -EIO;
+        goto exit;
+    }
+
+    if (pcm_start(handle.pcm_tx) < 0) {
+        ALOGI("%s: retrying pcm_start...", __func__);
+	usleep(500 * 1000);
+        if (pcm_start(handle.pcm_tx) < 0) {
+            ALOGI("%s: pcm start for TX failed; error = %s", __func__,
+                  pcm_get_error(handle.pcm_tx));
+            ret = -EINVAL;
+        }
+    }
+
+exit:
+    if (ret) {
+        ALOGI("%s: Disable and bail out", __func__);
+        if (handle.pcm_tx) {
+            ALOGI("%s: pcm_tx_close", __func__);
+            pcm_close(handle.pcm_tx);
+            handle.pcm_tx = NULL;
+        }
+
+        disable_audio_route(adev, uc_info_tx);
+        disable_snd_device(adev, SND_DEVICE_IN_CAPTURE_VI_FEEDBACK);
+        list_remove(&uc_info_tx->list);
+        free(uc_info_tx);
+    }
+
+    pthread_mutex_unlock(&handle.mutex_fb_prot);
+    ALOGV("%s: Exit", __func__);
+    return ret;
+}
+
+void audio_extn_spkr_prot_stop_processing(snd_device_t snd_device) {
+    struct audio_usecase *uc_info_tx;
+    struct audio_device *adev = handle.adev_handle;
+
+    ALOGV("%s: Entry", __func__);
+
+    pthread_mutex_lock(&handle.mutex_fb_prot);
+
+    uc_info_tx = get_usecase_from_list(adev, USECASE_AUDIO_SPKR_CALIB_TX);
+
+    if (uc_info_tx) {
+        if (handle.pcm_tx) {
+            ALOGI("%s: pcm_tx_close", __func__);
+            pcm_close(handle.pcm_tx);
+            handle.pcm_tx = NULL;
+        }
+
+        disable_audio_route(adev, uc_info_tx);
+        disable_snd_device(adev, SND_DEVICE_IN_CAPTURE_VI_FEEDBACK);
+        list_remove(&uc_info_tx->list);
+        free(uc_info_tx);
+
+        audio_route_reset_path(adev->audio_route,
+                               platform_get_snd_device_name(snd_device));
+    }
+
+    pthread_mutex_unlock(&handle.mutex_fb_prot);
+
+    ALOGV("%s: Exit", __func__);
+}
+
+bool audio_extn_spkr_prot_is_enabled() {
+    return handle.spkr_prot_enable;
+}
+
+int audio_extn_spkr_prot_get_acdb_id(snd_device_t snd_device) {
+    int acdb_id;
+
+    switch (snd_device) {
+    case SND_DEVICE_OUT_SPEAKER:
+        acdb_id = platform_get_snd_device_acdb_id(SND_DEVICE_OUT_SPEAKER_PROTECTED);
+        break;
+    case SND_DEVICE_OUT_VOICE_SPEAKER:
+        acdb_id = platform_get_snd_device_acdb_id(SND_DEVICE_OUT_VOICE_SPEAKER_PROTECTED);
+        break;
+    default:
+        acdb_id = -EINVAL;
+        break;
+    }
+    return acdb_id;
+}
+
+int audio_extn_get_spkr_prot_snd_device(snd_device_t snd_device) {
+    switch(snd_device) {
+    case SND_DEVICE_OUT_SPEAKER:
+        return SND_DEVICE_OUT_SPEAKER_PROTECTED;
+    case SND_DEVICE_OUT_VOICE_SPEAKER:
+        return SND_DEVICE_OUT_VOICE_SPEAKER_PROTECTED;
+    default:
+        return snd_device;
+    }
+}
+
+void audio_extn_spkr_prot_calib_cancel(__unused void *adev) {
+    // FIXME: wait or cancel audio_extn_cirrus_run_calibration
+}