Sensor Monitor support (#393)

New base class is introduced for defining voltage and current sensors.
Chassis and Module base classes are enhanced with APIs to retrieve voltage and current sensor data from platform.

sonic_platform_base/__init__.py

@@ -8,4 +8,5 @@
 from . import psu_base
 from . import sfp_base
 from . import thermal_base
+from . import sensor_base
 from . import watchdog_base

sonic_platform_base/chassis_base.py

@@ -54,6 +54,8 @@ def __init__(self):
         # List of ThermalBase-derived objects representing all thermals
         # available on the chassis
         self._thermal_list = []
+        self._voltage_sensor_list = []
+        self._current_sensor_list = []
 
         # List of SfpBase-derived objects representing all sfps
         # available on the chassis
@@ -451,6 +453,95 @@ def get_thermal_manager(self):
         """
         raise NotImplementedError
 
+    ##############################################
+    # Voltage Sensor Methods
+    ##############################################
+
+    def get_num_voltage_sensors(self):
+        """
+        Retrieves the number of voltage sensors available on this chassis
+
+        Returns:
+            An integer, the number of voltage sensors available on this chassis
+        """
+        return len(self._voltage_sensor_list)
+
+    def get_all_voltage_sensors(self):
+        """
+        Retrieves all voltage sensors available on this chassis
+
+        Returns:
+            A list of objects derived from VoltageSensorBase representing all voltage 
+            sensors available on this chassis
+        """
+        return self._voltage_sensor_list
+
+    def get_voltage_sensor(self, index):
+        """
+        Retrieves voltage sensor unit represented by (0-based) index <index>
+
+        Args:
+            index: An integer, the index (0-based) of the voltage sensor to
+            retrieve
+
+        Returns:
+            An object derived from VoltageSensorBase representing the specified voltage sensor
+        """
+        voltage_sensor = None
+
+        try:
+            voltage_sensor = self._voltage_sensor_list[index]
+        except IndexError:
+            sys.stderr.write("Voltage sensor index {} out of range (0-{})\n".format(
+                             index, len(self._voltage_sensor_list)-1))
+
+        return voltage_sensor
+
+    ##############################################
+    # Current Sensor Methods
+    ##############################################
+
+    def get_num_current_sensors(self):
+        """
+        Retrieves the number of current sensors available on this chassis
+
+        Returns:
+            An integer, the number of current sensors available on this chassis
+        """
+        return len(self._current_sensor_list)
+
+    def get_all_current_sensors(self):
+        """
+        Retrieves all current sensors available on this chassis
+
+        Returns:
+            A list of objects derived from CurrentSensorBase representing all current
+            sensors available on this chassis
+        """
+        return self._current_sensor_list
+
+    def get_current_sensor(self, index):
+        """
+        Retrieves current sensor object represented by (0-based) index <index>
+
+        Args:
+            index: An integer, the index (0-based) of the current sensor to
+            retrieve
+
+        Returns:
+            An object derived from CurrentSensorBase representing the specified current 
+            sensor
+        """
+        current_sensor = None
+
+        try:
+            current_sensor = self._current_sensor_list[index]
+        except IndexError:
+            sys.stderr.write("Current sensor index {} out of range (0-{})\n".format(
+                             index, len(self._current_sensor_list)-1))
+
+        return current_sensor
+
     ##############################################
     # SFP methods
     ##############################################

sonic_platform_base/module_base.py

@@ -66,6 +66,8 @@ def __init__(self):
         # List of ThermalBase-derived objects representing all thermals
         # available on the module
         self._thermal_list = []
+        self._voltage_sensor_list = []
+        self._current_sensor_list = []
 
         # List of SfpBase-derived objects representing all sfps
         # available on the module
@@ -372,6 +374,95 @@ def get_thermal(self, index):
 
         return thermal
 
+    ##############################################
+    # Voltage Sensor methods
+    ##############################################
+
+    def get_num_voltage_sensors(self):
+        """
+        Retrieves the number of voltage sensors available on this module
+
+        Returns:
+            An integer, the number of voltage sensors available on this module
+        """
+        return len(self._voltage_sensor_list)
+
+    def get_all_voltage_sensors(self):
+        """
+        Retrieves all voltage sensors available on this module
+
+        Returns:
+            A list of objects derived from VoltageSensorBase representing all voltage
+            sensors available on this module
+        """
+        return self._voltage_sensor_list
+
+    def get_voltage_sensor(self, index):
+        """
+        Retrieves voltage sensor unit represented by (0-based) index <index>
+
+        Args:
+            index: An integer, the index (0-based) of the voltage sensor to
+            retrieve
+
+        Returns:
+            An object derived from VoltageSensorBase representing the specified voltage
+            sensor
+        """
+        voltage_sensor = None
+
+        try:
+            voltage_sensor = self._voltage_sensor_list[index]
+        except IndexError:
+            sys.stderr.write("Voltage sensor index {} out of range (0-{})\n".format(
+                             index, len(self._voltage_sensor_list)-1))
+
+        return voltage_sensor
+
+    ##############################################
+    # Current sensor methods
+    ##############################################
+
+    def get_num_current_sensors(self):
+        """
+        Retrieves the number of current sensors available on this module
+
+        Returns:
+            An integer, the number of current sensors available on this module
+        """
+        return len(self._current_sensor_list)
+
+    def get_all_current_sensors(self):
+        """
+        Retrieves all current sensors available on this module
+
+        Returns:
+            A list of objects derived from CurrentSensorBase representing all current
+            sensors available on this module
+        """
+        return self._current_sensor_list
+
+    def get_current_sensor(self, index):
+        """
+        Retrieves current sensor object represented by (0-based) index <index>
+
+        Args:
+            index: An integer, the index (0-based) of the current sensor to
+            retrieve
+
+        Returns:
+            An object derived from CurrentSensorBase representing the specified current_sensor
+        """
+        current_sensor = None
+
+        try:
+            current_sensor = self._current_sensor_list[index]
+        except IndexError:
+            sys.stderr.write("Current sensor index {} out of range (0-{})\n".format(
+                             index, len(self._current_sensor_list)-1))
+
+        return current_sensor
+
     ##############################################
     # SFP methods
     ##############################################

sonic_platform_base/sensor_base.py

@@ -0,0 +1,173 @@
+"""
+    sensor_base.py
+
+    Abstract base class for implementing a platform-specific class with which
+    to interact with a sensor module in SONiC
+"""
+
+from . import device_base
+
+class SensorBase(device_base.DeviceBase):
+    """
+    Abstract base class for interfacing with a sensor module
+    """
+
+    @classmethod
+    def get_type(cls):
+        """
+        Specifies the type of the sensor such as current/voltage etc.
+
+        Returns:
+            Sensor type
+        """
+        raise NotImplementedError
+
+    def get_value(self):
+        """
+        Retrieves measurement reported by sensor
+
+        Returns:
+            Sensor measurement
+        """
+        raise NotImplementedError
+
+    @classmethod
+    def get_unit(cls):
+        """
+        Retrieves unit of measurement reported by sensor
+
+        Returns:
+            Sensor measurement unit
+        """
+        raise NotImplementedError
+
+    def get_high_threshold(self):
+        """
+        Retrieves the high threshold of sensor
+
+        Returns:
+            High threshold 
+        """
+        raise NotImplementedError
+
+    def get_low_threshold(self):
+        """
+        Retrieves the low threshold 
+
+        Returns:
+            Low threshold 
+        """
+        raise NotImplementedError
+
+    def set_high_threshold(self, value):
+        """
+        Sets the high threshold value of sensor
+
+        Args:
+            value: High threshold value to set
+
+        Returns:
+            A boolean, True if threshold is set successfully, False if not
+        """
+        raise NotImplementedError
+
+    def set_low_threshold(self, value):
+        """
+        Sets the low threshold value of sensor
+
+        Args:
+            value: Value 
+
+        Returns:
+            A boolean, True if threshold is set successfully, False if not
+        """
+        raise NotImplementedError
+
+    def get_high_critical_threshold(self):
+        """
+        Retrieves the high critical threshold value of sensor
+
+        Returns:
+            The high critical threshold value of sensor 
+        """
+        raise NotImplementedError
+
+    def get_low_critical_threshold(self):
+        """
+        Retrieves the low critical threshold value of sensor
+
+        Returns:
+            The low critical threshold value of sensor 
+        """
+        raise NotImplementedError
+
+    def set_high_critical_threshold(self, value):
+        """
+        Sets the critical high threshold value of sensor
+
+        Args:
+            value: Critical high threshold Value 
+
+        Returns:
+            A boolean, True if threshold is set successfully, False if not
+        """
+        raise NotImplementedError
+
+    def set_low_critical_threshold(self, value):
+        """
+        Sets the critical low threshold value of sensor
+
+        Args:
+            value: Critial low threshold Value 
+
+        Returns:
+            A boolean, True if threshold is set successfully, False if not
+        """
+        raise NotImplementedError
+
+    def get_minimum_recorded(self):
+        """
+        Retrieves the minimum recorded value of sensor
+
+        Returns:
+            The minimum recorded value of sensor 
+        """
+        raise NotImplementedError
+
+    def get_maximum_recorded(self):
+        """
+        Retrieves the maximum recorded value of sensor
+
+        Returns:
+            The maximum recorded value of sensor 
+        """
+        raise NotImplementedError
+
+
+
+class VoltageSensorBase(SensorBase):
+    """
+    Abstract base class for interfacing with a voltage sensor module
+    """
+
+    @classmethod
+    def get_type(cls):
+        return "SENSOR_TYPE_VOLTAGE"
+
+    @classmethod
+    def get_unit(cls):
+        return "mV"
+
+
+class CurrentSensorBase(SensorBase):
+    """
+    Abstract base class for interfacing with a current sensor module
+    """
+
+    @classmethod
+    def get_type(cls):
+        return "SENSOR_TYPE_CURRENT"
+
+    @classmethod
+    def get_unit(cls):
+        return "mA"