thermal-hal: Re-arch thermal HAL implementation

Re-design thermal HAL server side implementation
to accomodate below features.
-Use sensor names and get thermal zone ids on the fly
 using sensor names.
-Generalize APIs implementation and remove repeated
 code implementation in target specific files.
-Minimize target specific configuration and avoid
 target specific file going forward.

Change-Id: Ib61c591d60d17aaeac0eb84ec9b3a4775173a416

5 files changed, 572 insertions, 318 deletions

diff --git a/Android.mk b/Android.mk
index c8725dd..797e5b2 100644
--- a/Android.mk
+++ b/Android.mk
@@ -23,12 +23,14 @@ LOCAL_PROPRIETARY_MODULE := true
 ifeq ($(call is-board-platform-in-list,msm8998), true)
 LOCAL_SRC_FILES := thermal.c
 LOCAL_SRC_FILES += thermal-8998.c
+LOCAL_SRC_FILES += thermal_common.c
 SUPPORT_THERMAL_HAL:=1
 endif
 
 ifeq ($(call is-board-platform-in-list,sdm845), true)
 LOCAL_SRC_FILES := thermal.c
 LOCAL_SRC_FILES += thermal-845.c
+LOCAL_SRC_FILES += thermal_common.c
 SUPPORT_THERMAL_HAL:=1
 endif
 
diff --git a/thermal-845.c b/thermal-845.c
index a6a9e3e..59925b5 100644
--- a/thermal-845.c
+++ b/thermal-845.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017-2018 The Linux Foundation. All rights reserved.
  * Not a contribution
  * Copyright (C) 2016 The Android Open Source Project
  *
@@ -16,177 +16,85 @@
  * limitations under the License.
  */
 
-#include <ctype.h>
-#include <errno.h>
-#include <inttypes.h>
-#include <stdlib.h>
-#include <string.h>
 
 #define LOG_TAG "ThermalHAL-845"
 #include <utils/Log.h>
 
 #include <hardware/hardware.h>
 #include <hardware/thermal.h>
-
-#define MAX_LENGTH                    50
-
-#define TEMPERATURE_FILE_FORMAT       "/sys/class/thermal/thermal_zone%d/temp"
-
-#define BATTERY_SENSOR_NUM            60
-#define GPU_SENSOR_NUM                11
-#define SKIN_SENSOR_NUM               56
-
-const int CPU_SENSORS[] = {1, 2, 3, 4, 7, 8, 9,10};
-
-#define CPU_NUM                       (sizeof(CPU_SENSORS) / sizeof(int))
-// Sum of CPU_NUM + 3 for GPU, BATTERY, and SKIN.
-#define TEMPERATURE_NUM               (CPU_NUM + 3)
-
-//therm-reset-temp
-#define CPU_SHUTDOWN_THRESHOLD        115
-//limit-temp
-#define CPU_THROTTLING_THRESHOLD      60
-#define BATTERY_SHUTDOWN_THRESHOLD    60
-//must match thermal-engine.conf
-#define SKIN_THROTTLING_THRESHOLD     44
-#define SKIN_SHUTDOWN_THRESHOLD       70
-#define VR_THROTTLED_BELOW_MIN        58
-
-#define GPU_LABEL                     "GPU"
-#define BATTERY_LABEL                 "battery"
-#define SKIN_LABEL                    "skin"
-
-const char *CPU_LABEL[] = {"CPU0", "CPU1", "CPU2", "CPU3", "CPU4", "CPU5", "CPU6", "CPU7"};
-
-const char *get_cpu_label(unsigned int cpu_num) {
-    ALOGD("Entering %s",__func__);
-    if(cpu_num >= CPU_NUM)
-        return NULL;
-
-    return CPU_LABEL[cpu_num];
-}
-
-size_t get_num_cpus() {
-    ALOGD("Entering %s",__func__);
-    return CPU_NUM;
-}
-
-/**
- * Reads device temperature.
- *
- * @param sensor_num Number of sensor file with temperature.
- * @param type Device temperature type.
- * @param name Device temperature name.
- * @param mult Multiplier used to translate temperature to Celsius.
- * @param throttling_threshold Throttling threshold for the temperature.
- * @param shutdown_threshold Shutdown threshold for the temperature.
- * @param out Pointer to temperature_t structure that will be filled with current
- *     values.
- *
- * @return 0 on success or negative value -errno on error.
- */
-static ssize_t read_temperature(int sensor_num, int type, const char *name, float mult,
-        float throttling_threshold, float shutdown_threshold, float vr_throttling_threshold,
-        temperature_t *out) {
-    ALOGD("Entering %s",__func__);
-    FILE *file;
-    char file_name[MAX_LENGTH];
-    float temp;
-
-    snprintf(file_name, sizeof(file_name), TEMPERATURE_FILE_FORMAT, sensor_num);
-    file = fopen(file_name, "r");
-    if (file == NULL) {
-        ALOGE("%s: failed to open: %s", __func__, strerror(errno));
-        return -errno;
+#include "thermal_common.h"
+
+static char *cpu_sensors_845[] =
+{
+    "cpu0-silver-usr",
+    "cpu1-silver-usr",
+    "cpu2-silver-usr",
+    "cpu3-silver-usr",
+    "cpu0-gold-usr",
+    "cpu1-gold-usr",
+    "cpu2-gold-usr",
+    "cpu3-gold-usr",
+};
+
+static char *misc_sensors_845[] =
+{
+    "gpu0-usr",
+    "battery",
+    "xo-therm-adc"
+};
+
+static struct target_therm_cfg sensor_cfg_845[] = {
+    {
+        .type = DEVICE_TEMPERATURE_CPU,
+        .sensor_list = cpu_sensors_845,
+        .sens_cnt = ARRAY_SIZE(cpu_sensors_845),
+        .mult = 0.001,
+        .throt_thresh = 60,
+        .shutdwn_thresh = 115,
+    },
+    {
+        .type = DEVICE_TEMPERATURE_GPU,
+        .sensor_list = &misc_sensors_845[0],
+        .sens_cnt = 1,
+        .mult = 0.001,
+        .label = "GPU",
+    },
+    {
+        .type = DEVICE_TEMPERATURE_BATTERY,
+        .sensor_list = &misc_sensors_845[1],
+        .sens_cnt = 1,
+        .mult = 0.001,
+        .shutdwn_thresh = 60,
+        .label = "battery",
+    },
+    {
+        .type = DEVICE_TEMPERATURE_SKIN,
+        .sensor_list = &misc_sensors_845[2],
+        .sens_cnt = 1,
+        .mult = 0.001,
+        .throt_thresh = 44,
+        .shutdwn_thresh = 70,
+        .vr_thresh = 58,
+        .label = "skin",
     }
-    if (1 != fscanf(file, "%f", &temp)) {
-        fclose(file);
-        ALOGE("%s: failed to read a float: %s", __func__, strerror(errno));
-        return errno ? -errno : -EIO;
-    }
-
-    fclose(file);
-
-    (*out) = (temperature_t) {
-        .type = type,
-        .name = name,
-        .current_value = temp * mult,
-        .throttling_threshold = throttling_threshold,
-        .shutdown_threshold = shutdown_threshold,
-        .vr_throttling_threshold = vr_throttling_threshold
-    };
-
-    return 0;
-}
-
-static ssize_t get_cpu_temperatures(temperature_t *list, size_t size) {
-    ALOGD("Entering %s",__func__);
-    size_t cpu;
-    for (cpu = 0; cpu < CPU_NUM; cpu++) {
-        if (cpu >= size) {
-            break;
-        }
-        // tsens_tz_sensor[4,6,9,11]: temperature in decidegrees Celsius.
-        ssize_t result = read_temperature(CPU_SENSORS[cpu], DEVICE_TEMPERATURE_CPU, CPU_LABEL[cpu],
-                0.001, CPU_THROTTLING_THRESHOLD, CPU_SHUTDOWN_THRESHOLD, UNKNOWN_TEMPERATURE,
-                &list[cpu]);
-        if (result != 0) {
-            return result;
-        }
-    }
-
-    return cpu;
-}
+};
 
 ssize_t get_temperatures(thermal_module_t *module, temperature_t *list, size_t size) {
     ALOGD("Entering %s",__func__);
-    ssize_t result = 0;
-    size_t current_index = 0;
-
-    if (list == NULL) {
-        return TEMPERATURE_NUM;
-    }
-
-    result = get_cpu_temperatures(list, size);
-    if (result < 0) {
-        return result;
-    }
-    current_index += result;
-
-    // GPU temperature.
-    if (current_index < size) {
-        // tsens_tz_sensor14: temperature in millidegrees Celsius.
-        result = read_temperature(GPU_SENSOR_NUM, DEVICE_TEMPERATURE_GPU, GPU_LABEL, 0.001,
-                UNKNOWN_TEMPERATURE, UNKNOWN_TEMPERATURE, UNKNOWN_TEMPERATURE,
-                &list[current_index]);
-        if (result < 0) {
-            return result;
+    static int thermal_sens_size;
+
+    if (!thermal_sens_size) {
+	thermal_sens_size = thermal_zone_init(sensor_cfg_845,
+                                ARRAY_SIZE(sensor_cfg_845));
+        if (thermal_sens_size <= 0) {
+            ALOGE("thermal sensor initialization is failed\n");
+            thermal_sens_size = 0;
+            return 0;
         }
-        current_index++;
     }
 
-    // Battery temperature.
-    if (current_index < size) {
-        // tsens_tz_sensor29: battery: temperature in millidegrees Celsius.
-        result = read_temperature(BATTERY_SENSOR_NUM, DEVICE_TEMPERATURE_BATTERY, BATTERY_LABEL,
-                0.001, UNKNOWN_TEMPERATURE, BATTERY_SHUTDOWN_THRESHOLD, UNKNOWN_TEMPERATURE,
-                &list[current_index]);
-        if (result < 0) {
-            return result;
-        }
-        current_index++;
-    }
+    if (list == NULL)
+        return thermal_sens_size;
 
-    // Skin temperature.
-    if (current_index < size) {
-        // tsens_tz_sensor24: temperature in millidegrees Celsius.
-        result = read_temperature(SKIN_SENSOR_NUM, DEVICE_TEMPERATURE_SKIN, SKIN_LABEL, .001,
-                SKIN_THROTTLING_THRESHOLD, SKIN_SHUTDOWN_THRESHOLD, VR_THROTTLED_BELOW_MIN,
-                &list[current_index]);
-        if (result < 0) {
-            return result;
-        }
-        current_index++;
-    }
-    return TEMPERATURE_NUM;
+    return get_temperature_for_all(list, size);
 }
diff --git a/thermal-8998.c b/thermal-8998.c
index a43159b..94bf375 100644
--- a/thermal-8998.c
+++ b/thermal-8998.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017-2018 The Linux Foundation. All rights reserved.
  * Not a contribution
  * Copyright (C) 2016 The Android Open Source Project
  *
@@ -16,178 +16,85 @@
  * limitations under the License.
  */
 
-#include <ctype.h>
-#include <errno.h>
-#include <inttypes.h>
-#include <stdlib.h>
-#include <string.h>
 
 #define LOG_TAG "ThermalHAL-8998"
 #include <utils/Log.h>
 
 #include <hardware/hardware.h>
 #include <hardware/thermal.h>
+#include "thermal_common.h"
 
-#define MAX_LENGTH                    50
-
-#define TEMPERATURE_FILE_FORMAT       "/sys/class/thermal/thermal_zone%d/temp"
-
-#define BATTERY_SENSOR_NUM            0
-#define GPU_SENSOR_NUM                17
-#define SKIN_SENSOR_NUM               5
-
-const int CPU_SENSORS[] = {8, 9, 10, 11, 12, 13, 14,15};
-
-#define CPU_NUM                       (sizeof(CPU_SENSORS) / sizeof(int))
-// Sum of CPU_NUM + 3 for GPU, BATTERY, and SKIN.
-#define TEMPERATURE_NUM               (CPU_NUM + 3)
-
-//therm-reset-temp
-#define CPU_SHUTDOWN_THRESHOLD        115
-//limit-temp
-#define CPU_THROTTLING_THRESHOLD      60
-#define BATTERY_SHUTDOWN_THRESHOLD    60
-//must match thermal-engine.conf
-#define SKIN_THROTTLING_THRESHOLD     44
-#define SKIN_SHUTDOWN_THRESHOLD       70
-#define VR_THROTTLED_BELOW_MIN        58
-
-#define GPU_LABEL                     "GPU"
-#define BATTERY_LABEL                 "battery"
-#define SKIN_LABEL                    "skin"
-
-const char *CPU_LABEL[] = {"CPU0", "CPU1", "CPU2", "CPU3", "CPU4", "CPU5", "CPU6", "CPU7"};
-
-const char *get_cpu_label(unsigned int cpu_num) {
-
-    if(cpu_num >= CPU_NUM)
-        return NULL;
-
-    return CPU_LABEL[cpu_num];
-}
-
-size_t get_num_cpus() {
-    return CPU_NUM;
-}
-
-/**
- * Reads device temperature.
- *
- * @param sensor_num Number of sensor file with temperature.
- * @param type Device temperature type.
- * @param name Device temperature name.
- * @param mult Multiplier used to translate temperature to Celsius.
- * @param throttling_threshold Throttling threshold for the temperature.
- * @param shutdown_threshold Shutdown threshold for the temperature.
- * @param out Pointer to temperature_t structure that will be filled with current
- *     values.
- *
- * @return 0 on success or negative value -errno on error.
- */
-static ssize_t read_temperature(int sensor_num, int type, const char *name, float mult,
-        float throttling_threshold, float shutdown_threshold, float vr_throttling_threshold,
-        temperature_t *out) 
+static char *cpu_sensors_8998[] =
 {
-    ALOGD("Entering %s",__func__);
-    FILE *file;
-    char file_name[MAX_LENGTH];
-    float temp;
-
-    snprintf(file_name, sizeof(file_name), TEMPERATURE_FILE_FORMAT, sensor_num);
-    file = fopen(file_name, "r");
-    if (file == NULL) {
-        ALOGE("%s: failed to open: %s", __func__, strerror(errno));
-        return -errno;
-    }
-    if (1 != fscanf(file, "%f", &temp)) {
-        fclose(file);
-        ALOGE("%s: failed to read a float: %s", __func__, strerror(errno));
-        return errno ? -errno : -EIO;
-    }
-
-    fclose(file);
-
-    (*out) = (temperature_t) {
-        .type = type,
-        .name = name,
-        .current_value = temp * mult,
-        .throttling_threshold = throttling_threshold,
-        .shutdown_threshold = shutdown_threshold,
-        .vr_throttling_threshold = vr_throttling_threshold
-    };
-
-    return 0;
-}
-
-static ssize_t get_cpu_temperatures(temperature_t *list, size_t size) 
+    "tsens_tz_sensor1",
+    "tsens_tz_sensor2",
+    "tsens_tz_sensor3",
+    "tsens_tz_sensor4",
+    "tsens_tz_sensor7",
+    "tsens_tz_sensor8",
+    "tsens_tz_sensor9",
+    "tsens_tz_sensor10",
+};
+
+static char *misc_sensors_8998[] =
 {
-    ALOGD("Entering %s",__func__);
-    size_t cpu;
-    for (cpu = 0; cpu < CPU_NUM; cpu++) {
-        if (cpu >= size) {
-            break;
-        }
-        // tsens_tz_sensor[4,6,9,11]: temperature in decidegrees Celsius.
-        ssize_t result = read_temperature(CPU_SENSORS[cpu], DEVICE_TEMPERATURE_CPU, CPU_LABEL[cpu],
-                0.1, CPU_THROTTLING_THRESHOLD, CPU_SHUTDOWN_THRESHOLD, UNKNOWN_TEMPERATURE,
-                &list[cpu]);
-        if (result != 0) {
-            return result;
-        }
+    "tsens_tz_sensor12",
+    "battery",
+    "quiet_therm"
+};
+
+static struct target_therm_cfg sensor_cfg_8998[] = {
+    {
+        .type = DEVICE_TEMPERATURE_CPU,
+        .sensor_list = cpu_sensors_8998,
+        .sens_cnt = ARRAY_SIZE(cpu_sensors_8998),
+        .mult = 0.1,
+        .throt_thresh = 60,
+        .shutdwn_thresh = 115,
+    },
+    {
+        .type = DEVICE_TEMPERATURE_GPU,
+        .sensor_list = &misc_sensors_8998[0],
+        .sens_cnt = 1,
+        .mult = 0.1,
+        .label = "GPU",
+    },
+    {
+        .type = DEVICE_TEMPERATURE_BATTERY,
+        .sensor_list = &misc_sensors_8998[1],
+        .sens_cnt = 1,
+        .mult = 0.001,
+        .shutdwn_thresh = 60,
+        .label = "battery",
+    },
+    {
+        .type = DEVICE_TEMPERATURE_SKIN,
+        .sensor_list = &misc_sensors_8998[2],
+        .sens_cnt = 1,
+        .mult = 1.0,
+        .throt_thresh = 44,
+        .shutdwn_thresh = 70,
+        .vr_thresh = 58,
+        .label = "skin",
     }
-
-    return cpu;
-}
+};
 
 ssize_t get_temperatures(thermal_module_t *module, temperature_t *list, size_t size) {
     ALOGD("Entering %s",__func__);
-    ssize_t result = 0;
-    size_t current_index = 0;
-
-    if (list == NULL) {
-        return TEMPERATURE_NUM;
-    }
-
-    result = get_cpu_temperatures(list, size);
-    if (result < 0) {
-        return result;
-    }
-    current_index += result;
-
-    // GPU temperature.
-    if (current_index < size) {
-        // tsens_tz_sensor14: temperature in decidegrees Celsius.
-        result = read_temperature(GPU_SENSOR_NUM, DEVICE_TEMPERATURE_GPU, GPU_LABEL, 0.1,
-                UNKNOWN_TEMPERATURE, UNKNOWN_TEMPERATURE, UNKNOWN_TEMPERATURE,
-                &list[current_index]);
-        if (result < 0) {
-            return result;
+    static int thermal_sens_size;
+
+    if (!thermal_sens_size) {
+        thermal_sens_size = thermal_zone_init(sensor_cfg_8998,
+                                ARRAY_SIZE(sensor_cfg_8998));
+        if (thermal_sens_size <= 0) {
+            ALOGE("thermal sensor initialization is failed\n");
+            thermal_sens_size = 0;
+            return 0;
         }
-        current_index++;
     }
 
-    // Battery temperature.
-    if (current_index < size) {
-        // tsens_tz_sensor29: battery: temperature in millidegrees Celsius.
-        result = read_temperature(BATTERY_SENSOR_NUM, DEVICE_TEMPERATURE_BATTERY, BATTERY_LABEL,
-                0.001, UNKNOWN_TEMPERATURE, BATTERY_SHUTDOWN_THRESHOLD, UNKNOWN_TEMPERATURE,
-                &list[current_index]);
-        if (result < 0) {
-            return result;
-        }
-        current_index++;
-    }
+    if (list == NULL)
+        return thermal_sens_size;
 
-    // Skin temperature.
-    if (current_index < size) {
-        // tsens_tz_sensor24: temperature in Celsius.
-        result = read_temperature(SKIN_SENSOR_NUM, DEVICE_TEMPERATURE_SKIN, SKIN_LABEL, 1.,
-                SKIN_THROTTLING_THRESHOLD, SKIN_SHUTDOWN_THRESHOLD, VR_THROTTLED_BELOW_MIN,
-                &list[current_index]);
-        if (result < 0) {
-            return result;
-        }
-        current_index++;
-    }
-    return TEMPERATURE_NUM;
+    return get_temperature_for_all(list, size);
 }
diff --git a/thermal_common.c b/thermal_common.c
new file mode 100644
index 0000000..803b0a1
--- /dev/null
+++ b/thermal_common.c
@@ -0,0 +1,385 @@
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ * Not a contribution
+ * 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 <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <dirent.h>
+
+#define LOG_TAG "ThermalHAL-UTIL"
+#include <utils/Log.h>
+
+#include <hardware/hardware.h>
+#include <hardware/thermal.h>
+#include "thermal_common.h"
+
+#define MAX_LENGTH    50
+#define MAX_PATH      (256)
+#define CPU_LABEL      "CPU%d"
+#define THERMAL_SYSFS  "/sys/devices/virtual/thermal"
+#define TZ_DIR_NAME    "thermal_zone"
+#define TZ_DIR_FMT     "thermal_zone%d"
+#define THERMAL_TYPE "/sys/devices/virtual/thermal/%s/type"
+#define TEMPERATURE_FILE_FORMAT  "/sys/class/thermal/thermal_zone%d/temp"
+
+static char **cpu_label;
+static struct vendor_temperature *sensors;
+static unsigned int sensor_cnt;
+
+/**
+ * Get number of cpus of target.
+ *
+ * @return number of cpus on success or 0 on error.
+ */
+size_t get_num_cpus() {
+    ALOGD("Entering %s",__func__);
+    static int ncpus;
+
+    if (!ncpus) {
+        ncpus = (int)sysconf(_SC_NPROCESSORS_CONF);
+        if (ncpus < 1)
+            ALOGE("%s: Error retrieving number of cores", __func__);
+    }
+    return ncpus;
+}
+
+/**
+ * Get cpu label for a given cpu.
+ *
+ * @param cpu_num: cpu number.
+ *
+ * @return cpu label string on success or NULL on error.
+ */
+const char *get_cpu_label(unsigned int cpu_num) {
+    ALOGD("Entering %s",__func__);
+    unsigned int cpu = 0;
+
+    if (cpu_label == NULL) {
+        cpu_label= (char**)calloc(get_num_cpus(), sizeof(char *));
+	if (!cpu_label)
+		return NULL;
+	for(cpu = 0; cpu < get_num_cpus(); cpu++) {
+            cpu_label[cpu] = (char *)calloc(sizeof("CPUN"), sizeof(char));
+            if(!cpu_label[cpu])
+                return NULL;
+            snprintf(cpu_label[cpu], sizeof("CPUN"), CPU_LABEL, cpu);
+	}
+    }
+    if(cpu_num >= get_num_cpus())
+        return NULL;
+
+    return cpu_label[cpu_num];
+}
+
+/**
+ * Read data from a target sysfs file.
+ *
+ * @param path: Absolute path for a file to be read.
+ * @param buf: Char buffer to store data from file.
+ * @param count: Size of data buffer.
+ *
+ * @return number of bytes read on success or negative value on error.
+ */
+static int read_line_from_file(const char *path, char *buf, size_t count)
+{
+    char * fgets_ret;
+    FILE * fd;
+    int rv;
+
+    fd = fopen(path, "r");
+    if (fd == NULL)
+        return -1;
+
+    fgets_ret = fgets(buf, (int)count, fd);
+    if (NULL != fgets_ret) {
+        rv = (int)strlen(buf);
+    } else {
+        rv = ferror(fd);
+    }
+
+    fclose(fd);
+
+    return rv;
+}
+
+/**
+ * Function to get thermal zone id from sensor name.
+ *
+ * @param sensor_name: Name of sensor.
+ *
+ * @return positive integer on success or negative value on error.
+ */
+static int get_tzn(const char *sensor_name)
+{
+    DIR *tdir = NULL;
+    struct dirent *tdirent = NULL;
+    int found = -1;
+    int tzn = 0;
+    char name[MAX_PATH] = {0};
+    char cwd[MAX_PATH] = {0};
+    int ret = 0;
+
+    if (!getcwd(cwd, sizeof(cwd)))
+        return found;
+
+    /* Change dir to read the entries. Doesnt work otherwise */
+    ret = chdir(THERMAL_SYSFS);
+    if (ret) {
+        ALOGE("Unable to change to %s\n", THERMAL_SYSFS);
+        return found;
+    }
+    tdir = opendir(THERMAL_SYSFS);
+    if (!tdir) {
+        ALOGE("Unable to open %s\n", THERMAL_SYSFS);
+        return found;
+    }
+
+    while ((tdirent = readdir(tdir))) {
+        char buf[50];
+        struct dirent *tzdirent;
+        DIR *tzdir = NULL;
+
+        if (strncmp(tdirent->d_name, TZ_DIR_NAME,
+            strlen(TZ_DIR_NAME)) != 0)
+            continue;
+
+        tzdir = opendir(tdirent->d_name);
+        if (!tzdir)
+            continue;
+        while ((tzdirent = readdir(tzdir))) {
+            if (strcmp(tzdirent->d_name, "type"))
+                continue;
+            snprintf(name, MAX_PATH, THERMAL_TYPE,
+                    tdirent->d_name);
+            ret = read_line_from_file(name, buf, sizeof(buf));
+            if (ret <= 0) {
+                ALOGE("%s: sensor name read error for tz:%s\n",
+                        __func__, tdirent->d_name);
+                break;
+            }
+            if (buf[ret - 1] == '\n')
+                buf[ret - 1] = '\0';
+            else
+                buf[ret] = '\0';
+
+            if (!strcmp(buf, sensor_name)) {
+                found = 1;
+		break;
+            }
+        }
+        closedir(tzdir);
+        if (found == 1)
+            break;
+    }
+
+    if (found == 1) {
+        sscanf(tdirent->d_name, TZ_DIR_FMT, &tzn);
+        ALOGD("Sensor %s found at tz: %d\n",
+                sensor_name, tzn);
+        found = tzn;
+    }
+
+    closedir(tdir);
+    /* Restore current working dir */
+    ret = chdir(cwd);
+
+    return found;
+}
+
+/**
+ * Helper function for sensor intialization.
+ *
+ * @param v_sen_t: pointer to a sensor static config.
+ * @param sensor: pointer to a sensor vendor_temperature structure.
+ * @param type: Type of sensor ie cpu, battery, gpu, skin etc.
+ * @param sens_idx: Index for sensor of same type.
+ *
+ * @return 0 on success or negative value -errno on error.
+ */
+static int initialize_sensor(struct target_therm_cfg *v_sen_t,
+                               struct vendor_temperature *sensor,
+                               enum temperature_type type,
+                               int sens_idx)
+{
+    if (v_sen_t == NULL || sensor == NULL ||
+        sens_idx < 0) {
+         ALOGE("%s:Invalid input, sens_idx%d\n", __func__, sens_idx);
+         return -1;
+    }
+
+    sensor->tzn = get_tzn(v_sen_t->sensor_list[sens_idx]);
+    if (sensor->tzn < 0) {
+        ALOGE("No thermal zone for sensor: %s, ret:%d\n",
+               v_sen_t->sensor_list[sens_idx], sensor->tzn);
+        return -1;
+    }
+    if (type == DEVICE_TEMPERATURE_CPU)
+        sensor->t.name = get_cpu_label(sens_idx);
+    else
+        sensor->t.name = v_sen_t->label;
+
+    sensor->t.type = v_sen_t->type;
+    sensor->mult = v_sen_t->mult;
+
+    if (v_sen_t->throt_thresh != 0)
+        sensor->t.throttling_threshold = v_sen_t->throt_thresh;
+    else
+        sensor->t.throttling_threshold = UNKNOWN_TEMPERATURE;
+
+    if (v_sen_t->shutdwn_thresh != 0)
+        sensor->t.shutdown_threshold = v_sen_t->shutdwn_thresh;
+    else
+        sensor->t.shutdown_threshold = UNKNOWN_TEMPERATURE;
+
+    if (v_sen_t->vr_thresh != 0)
+        sensor->t.vr_throttling_threshold = v_sen_t->vr_thresh;
+    else
+        sensor->t.vr_throttling_threshold = UNKNOWN_TEMPERATURE;
+
+    return 0;
+}
+
+/**
+ * Initialize all sensors.
+ *
+ * @param v_sen_t: Base pointer to array of target specific sensor configs.
+ * @param cfg_cnt: Number of set of config for a given target.
+ *
+ * @return number of sensor on success or negative value or zero on error.
+ */
+int thermal_zone_init(struct target_therm_cfg *v_sen_t, int cfg_cnt)
+{
+    unsigned int idx = 0, cpu = 0;
+    int j = 0;
+
+    if (sensors != NULL && sensor_cnt != 0)
+        return sensor_cnt;
+
+    if (v_sen_t == NULL || cfg_cnt == 0) {
+        ALOGE("%s:Invalid input\n", __func__);
+        return -1;
+    }
+    sensors = calloc(get_num_cpus() + cfg_cnt - 1,
+        sizeof(struct vendor_temperature));
+
+    for (j = 0, idx = 0; j < cfg_cnt &&
+                idx < (get_num_cpus() + cfg_cnt - 1); j++) {
+        if (v_sen_t[j].type == DEVICE_TEMPERATURE_CPU) {
+            /* Initialize cpu thermal zone id */
+            for (cpu = 0; cpu < get_num_cpus() &&
+                        idx < (get_num_cpus() + cfg_cnt - 1); cpu++, idx++) {
+                if (initialize_sensor(&v_sen_t[j], &sensors[idx],
+                      v_sen_t[j].type, cpu)) {
+                        free(sensors);
+                        return -1;
+                }
+           }
+        } else {
+            /* Initialize misc thermal zone id */
+            if (initialize_sensor(&v_sen_t[j], &sensors[idx],
+                  v_sen_t[j].type, 0)) {
+                free(sensors);
+                return -1;
+            }
+            idx++;
+       }
+    }
+    sensor_cnt = idx;
+
+    return sensor_cnt;
+}
+
+/**
+ * Reads sensor temperature.
+ *
+ * @param sensor_num: thermal zone id for the sensor to be read
+ * @param type: Device temperature type.
+ * @param name: Device temperature name.
+ * @param mult: Multiplier used to translate temperature to Celsius.
+ * @param throttling_threshold: Throttling threshold for the sensor.
+ * @param shutdown_threshold: Shutdown threshold for the sensor.
+ * @param out: Pointer to temperature_t structure that will be filled with
+ *     temperature values.
+ *
+ * @return 0 on success or negative value -errno on error.
+ */
+static ssize_t read_temperature(int sensor_num, int type, const char *name,
+        float mult, float throttling_threshold, float shutdown_threshold,
+        float vr_throttling_threshold,
+        temperature_t *out) {
+    ALOGD("Entering %s",__func__);
+    char file_name[MAX_LENGTH];
+    float temp;
+    char buf[16] = {0};
+    int ret = 0;
+
+    snprintf(file_name, sizeof(file_name), TEMPERATURE_FILE_FORMAT, sensor_num);
+    ret = read_line_from_file(file_name, buf, sizeof(buf));
+    if (ret <= 0) {
+        ALOGE("Temperature read error: %d for sensor[%d]:%s\n",
+            ret, sensor_num, name);
+	return -1;
+    }
+    temp = atof(buf);
+
+    (*out) = (temperature_t) {
+        .type = type,
+        .name = name,
+        .current_value = temp * mult,
+        .throttling_threshold = throttling_threshold,
+        .shutdown_threshold = shutdown_threshold,
+        .vr_throttling_threshold = vr_throttling_threshold
+    };
+
+    return 0;
+}
+
+/**
+ * Reads all sensor temperature.
+ *
+ * @param list: Base pointer to array of temperature_t structure that will be
+ *     filled with temperature values.
+ * @param size: Number of sensor temperature needs to be filled in list.
+ *
+ * @return number of sensor data filled on success or 0 or negative value
+ *     -errno on error.
+ */
+ssize_t get_temperature_for_all(temperature_t *list, size_t size)
+{
+    ALOGD("Entering %s",__func__);
+    size_t idx;
+
+    if (sensors == NULL) {
+        ALOGE("No sensor configured\n");
+	return 0;
+    }
+
+    for (idx = 0; idx < sensor_cnt && idx < size; idx++) {
+        ssize_t result = read_temperature(sensors[idx].tzn, sensors[idx].t.type,
+                sensors[idx].t.name, sensors[idx].mult,
+                sensors[idx].t.throttling_threshold,
+                sensors[idx].t.shutdown_threshold,
+                sensors[idx].t.vr_throttling_threshold,
+                &list[idx]);
+        if (result != 0)
+            return result;
+    }
+    return idx;
+}
+
diff --git a/thermal_common.h b/thermal_common.h
new file mode 100644
index 0000000..4137322
--- /dev/null
+++ b/thermal_common.h
@@ -0,0 +1,52 @@
+/* Copyright (c) 2018, 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.
+ */
+
+#include <hardware/thermal.h>
+#define ARRAY_SIZE(x) (int)(sizeof(x)/sizeof(x[0]))
+
+struct target_therm_cfg {
+    enum temperature_type type;
+    char **sensor_list;
+    uint8_t sens_cnt;
+    char *label;
+    float mult;
+    int throt_thresh;
+    int shutdwn_thresh;
+    int vr_thresh;
+};
+
+struct vendor_temperature {
+    int tzn;
+    float mult;
+    temperature_t t;
+};
+
+size_t get_num_cpus();
+const char *get_cpu_label(unsigned int cpu_num);
+int thermal_zone_init(struct target_therm_cfg *v_sen_t, int cfg_cnt);
+ssize_t get_temperature_for_all(temperature_t *list, size_t size);