[AS9726-32D] Add CPU coretemp to thermal.py

Signed-off-by: Sean Wu <sean_wu@edge-core.com>

device/accton/x86_64-accton_as9726_32d-r0/sonic_platform/chassis.py

@@ -78,6 +78,7 @@ def __initialize_psu(self):
 
     def __initialize_thermals(self):
         from sonic_platform.thermal import Thermal
+        self._thermal_list.append(Thermal(is_cpu=True))
         for index in range(0, NUM_THERMAL):
             thermal = Thermal(index)
             self._thermal_list.append(thermal)

device/accton/x86_64-accton_as9726_32d-r0/sonic_platform/thermal.py

@@ -43,10 +43,11 @@
     },
 }
 
-THERMAL_NAME_LIST = ["Main Board 0x48", "Main Board 0x49", "Main Board 0x4A",
-                     "CPU Board 0x4B", "OCXO 0x4C", "Main Board 0x4F"]
+THERMAL_NAME_LIST = ("Main Board 0x48", "Main Board 0x49", "Main Board 0x4A",
+                     "CPU Board 0x4B", "OCXO 0x4C", "Main Board 0x4F")
 
-PSU_THERMAL_NAME_LIST = ["PSU-1 temp sensor 1", "PSU-2 temp sensor 1"]
+PSU_THERMAL_NAME_LIST = ("PSU-1 temp sensor 1", "PSU-2 temp sensor 1")
+CPU_THERMAL_NAME = "CPU Core temp"
 
 SYSFS_PATH = "/sys/bus/i2c/devices"
 
@@ -77,10 +78,15 @@ class Thermal(ThermalBase):
     }
     _thresholds = None
 
-    def __init__(self, thermal_index=0, is_psu=False, psu_index=0):
+    def __init__(self, thermal_index=0, is_psu=False, psu_index=0, is_cpu=False):
         self.index = thermal_index
         self.is_psu = is_psu
         self.psu_index = psu_index
+        self.is_cpu = is_cpu
+
+        if self.is_cpu:
+            self.cpu_paths = glob.glob('/sys/devices/platform/coretemp.0/hwmon/hwmon*/temp*_input')
+            self.cpu_path_idx = 0
 
         if self.is_psu:
             psu_i2c_bus = PSU_HWMON_I2C_MAPPING[psu_index]["num"]
@@ -128,13 +134,38 @@ def __get_temp(self, temp_file):
         else:
             return 0        
 
+    def __get_max_temp(self, paths):
+        max_temp = -1.0
+        max_idx = 0
+        for i, path in enumerate(paths):
+            read_temp = self.__get_temp(path)
+            if(read_temp > max_temp):
+                max_temp = read_temp
+                max_idx = i
+        return max_temp, max_idx
+
+    def __get_cpu_threshold(self, type):
+        path = self.cpu_paths[self.cpu_path_idx]
+        high_warn = self.__get_temp(path.replace('_input', '_max'))
+        if type == 'high_warn':
+            return high_warn
+        high_crit = self.__get_temp(path.replace('_input', '_crit'))
+        if type == 'high_crit':
+            return high_crit
+        if type == 'high_err':
+            return (high_crit + high_warn) / 2
+        return 0 # for all low_* thresholds
+
     def _try_get_threshold(self, type):
         if self.is_psu is True:
             return None
 
         if self._thresholds is None:
             self._thresholds = self._thresholds_F2B if is_fan_dir_F2B() else self._thresholds_B2F
 
+        if self.is_cpu:
+            return self.__get_cpu_threshold(type)
+
         if self.index in self._thresholds:
             return getattr(self._thresholds[self.index], type)
         else:
@@ -148,6 +179,10 @@ def get_temperature(self):
             A float number of current temperature in Celsius up to nearest thousandth
             of one degree Celsius, e.g. 30.125
         """
+        if self.is_cpu:
+            cpu_temp, self.cpu_path_idx = self.__get_max_temp(self.cpu_paths)
+            return cpu_temp
+
         if not self.is_psu:
             temp_file = "temp{}_input".format(self.ss_index)
         else:
@@ -160,6 +195,9 @@ def get_name(self):
             Returns:
             string: The name of the thermal device
         """
+        if self.is_cpu:
+            return CPU_THERMAL_NAME
+
         if self.is_psu:
             return PSU_THERMAL_NAME_LIST[self.psu_index]
         else:
@@ -171,6 +209,9 @@ def get_presence(self):
         Returns:
             bool: True if Thermal is present, False if not
         """
+        if self.is_cpu:
+            return True
+
         if self.is_psu:
             val = self.__read_txt_file(self.cpld_path + "psu_present")
             return int(val, 10) == 1
@@ -188,6 +229,9 @@ def get_status(self):
         Returns:
             A boolean value, True if device is operating properly, False if not
         """
+        if self.is_cpu:
+            return True
+
         if self.is_psu:
             temp_file = self.psu_hwmon_path + "psu_temp_fault"
             return self.get_presence() and (not int(