Enhance new platform API (sonic-net#19)

* Changes of SONiC new platform API based on latest design

* Moved get_change_event from DeviceBase to ChassisBase and ModuleBase

* chassis_base.py : added get_change_event
device_base.py : fixed typo
fan_base.py : defined DEVICE_TYPE
module_base.py : defined DEVICE_TYPE, fixed typo
psu_base.py : defined DEVICE_TYPE
sfp_base.py : defined DEVICE_TYPE, fixed typo, modified descriptions of set_power_override
thermal_base.py : defined DEVICE_TYPE

* module_base.py : modified get_change_event to return devices in nested dict

* Added dom related status support for SFP, including temperature, voltage, TX bias, TX power and RX power

* 1. Per channel return for TX bias, TX power and RX power in sfp_base.py.
2. Support system EEPROM and serial number in chassis_base.py.

* 1. Added SYS EEPROM functions to module_base.py.  2. Fixed typos.  3. Merge get_watchdog to return self._watchdog in chassis_base

* 1. Fixed various typos.  2. Changed get_ampere to get_current, get_watt to get_power in psu_base.py

* Changed get_system_eeprom return to use type code defined in ONIE TlvInfo EEPROM as the keys

sonic_platform_base/chassis_base.py

@@ -13,6 +13,8 @@ class ChassisBase(device_base.DeviceBase):
     """
     Base class for interfacing with a platform chassis
     """
+    # Device type definition. Note, this is a constant.
+    DEVICE_TYPE = "chassis"
 
     # Possible reboot causes
     REBOOT_CAUSE_POWER_LOSS = "power_loss"
@@ -36,6 +38,14 @@ class ChassisBase(device_base.DeviceBase):
     # available on the chassis
     _psu_list = []
 
+    # List of ThermalBase-derived objects representing all thermals
+    # available on the chassis
+    _thermal_list = []
+
+    # List of SfpBase-derived objects representing all sfps
+    # available on the chassis
+    _sfp_list = []
+
     # Object derived from WatchdogBase for interacting with hardware watchdog
     _watchdog = None
 
@@ -49,6 +59,29 @@ def get_base_mac(self):
         """
         raise NotImplementedError
 
+    def get_serial_number(self):
+        """
+        Retrieves the hardware serial number for the chassis
+
+        Returns:
+            A string containing the hardware serial number for this chassis.
+        """
+        raise NotImplementedError
+
+    def get_system_eeprom_info(self):
+        """
+        Retrieves the full content of system EEPROM information for the chassis
+
+        Returns:
+            A dictionary where keys are the type code defined in
+            OCP ONIE TlvInfo EEPROM format and values are their corresponding
+            values.
+            Ex. { ‘0x21’:’AG9064’, ‘0x22’:’V1.0’, ‘0x23’:’AG9064-0109867821’,
+                  ‘0x24’:’001c0f000fcd0a’, ‘0x25’:’02/03/2018 16:22:00’,
+                  ‘0x26’:’01’, ‘0x27’:’REV01’, ‘0x28’:’AG9064-C2358-16G’}
+        """
+        raise NotImplementedError
+
     def get_reboot_cause(self):
         """
         Retrieves the cause of the previous reboot
@@ -208,6 +241,93 @@ def get_psu(self, index):
 
         return psu
 
+    ##############################################
+    # THERMAL methods
+    ##############################################
+
+    def get_num_thermals(self):
+        """
+        Retrieves the number of thermals available on this chassis
+
+        Returns:
+            An integer, the number of thermals available on this chassis
+        """
+        return len(self._thermal_list)
+
+    def get_all_thermals(self):
+        """
+        Retrieves all thermals available on this chassis
+
+        Returns:
+            A list of objects derived from ThermalBase representing all thermals
+            available on this chassis
+        """
+        return self._thermal_list
+
+    def get_thermal(self, index):
+        """
+        Retrieves thermal unit represented by (0-based) index <index>
+
+        Args:
+            index: An integer, the index (0-based) of the thermal to
+            retrieve
+
+        Returns:
+            An object dervied from ThermalBase representing the specified thermal
+        """
+        thermal = None
+
+        try:
+            thermal = self._thermal_list[index]
+        except IndexError:
+            sys.stderr.write("THERMAL index {} out of range (0-{})\n".format(
+                             index, len(self._thermal_list)-1))
+
+        return thermal
+
+    ##############################################
+    # SFP methods
+    ##############################################
+
+    def get_num_sfps(self):
+        """
+        Retrieves the number of sfps available on this chassis
+
+        Returns:
+            An integer, the number of sfps available on this chassis
+        """
+        return len(self._sfp_list)
+
+    def get_all_sfps(self):
+        """
+        Retrieves all sfps available on this chassis
+
+        Returns:
+            A list of objects derived from SfpBase representing all sfps 
+            available on this chassis
+        """
+        return self._sfp_list
+
+    def get_sfp(self, index):
+        """
+        Retrieves sfp represented by (0-based) index <index>
+
+        Args:
+            index: An integer, the index (0-based) of the sfp to retrieve
+
+        Returns:
+            An object dervied from SfpBase representing the specified sfp
+        """
+        sfp = None
+
+        try:
+            sfp = self._sfp_list[index]
+        except IndexError:
+            sys.stderr.write("SFP index {} out of range (0-{})\n".format(
+                             index, len(self._sfp_list)-1))
+
+        return sfp
+
     ##############################################
     # Other methods
     ##############################################
@@ -221,3 +341,29 @@ def get_watchdog(self):
             watchdog device
         """
         return self._watchdog
+
+    def get_change_event(self, timeout=0):
+        """
+        Returns a nested dictionary containing all devices which have
+        experienced a change at chassis level
+
+        Args:
+            timeout: Timeout in milliseconds (optional). If timeout == 0,
+                this method will block until a change is detected.
+
+        Returns:
+            (bool, dict):
+                - True if call successful, False if not;
+                - A nested dictionary where key is a device type,
+                  value is a dictionary with key:value pairs in the format of
+                  {'device_id':'device_event'}, 
+                  where device_id is the device ID for this device and
+                        device_event,
+                             status='1' represents device inserted,
+                             status='0' represents device removed.
+                  Ex. {'fan':{'0':'0', '2':'1'}, 'sfp':{'11':'0'}}
+                      indicates that fan 0 has been removed, fan 2
+                      has been inserted and sfp 11 has been removed.
+        """
+        raise NotImplementedError
+

sonic_platform_base/device_base.py

@@ -11,6 +11,14 @@ class DeviceBase(object):
     peripheral device
     """
 
+    def get_name(self):
+        """
+        Retrieves the name of the device
+
+        Returns:
+            string: The name of the device
+        """
+
     def get_presence(self):
         """
         Retrieves the presence of the device
@@ -46,21 +54,3 @@ def get_status(self):
             A boolean value, True if device is operating properly, False if not
         """
         raise NotImplementedError
-
-    def get_change_event(self, timeout=0):
-        """
-        Returns a dictionary containing all devices which have experienced a
-        change
-
-        Args:
-            timeout: Timeout in milliseconds (optional). If timeout == 0,
-                this method will block until a change is detected.
-
-        Returns:
-            (bool, dict):
-                - True if call successful, False if not;
-                - Dict where key is device ID and value is device event,
-                  status='1' represents device inserted,
-                  status='0' represents device removed. Ex. {'0': '1', '1': '0'}
-        """
-        raise NotImplementedError

sonic_platform_base/fan_base.py

@@ -12,6 +12,8 @@ class FanBase(device_base.DeviceBase):
     """
     Abstract base class for interfacing with a fan module
     """
+    # Device type definition. Note, this is a constant.
+    DEVICE_TYPE = "fan"
 
     # Possible fan directions (relative to port-side of device)
     FAN_DIRECTION_INTAKE = "intake"