Create is_transceiver_vdm_supported API for CMIS transceivers (#527)

* Create is_transceiver_vdm_supported API for CMIS transceivers

Signed-off-by: Mihir Patel <[email protected]>

* Increased code coverage

* Enhanced unit test in test_sfp_optoe_base.py

---------

Signed-off-by: Mihir Patel <[email protected]>

sonic_platform_base/sonic_xcvr/api/public/cmis.py

@@ -1511,6 +1511,12 @@ def set_loopback_mode(self, loopback_mode, lane_mask = 0xff, enable = False):
         logger.error('Invalid loopback mode:%s, lane_mask:%#x', loopback_mode, lane_mask)
         return False
 
+    def is_transceiver_vdm_supported(self):
+        '''
+        This function returns whether VDM is supported
+        '''
+        return self.vdm is not None and self.xcvr_eeprom.read(consts.VDM_SUPPORTED)
+
     def get_vdm(self, field_option=None):
         '''
         This function returns all the VDM items, including real time monitor value, threholds and flags

sonic_platform_base/sonic_xcvr/api/xcvr_api.py

@@ -257,6 +257,12 @@ def get_transceiver_status_flags(self):
         """
         raise NotImplementedError
 
+    def is_transceiver_vdm_supported(self):
+        """
+        Retrieves VDM support status for this xcvr (applicable for CMIS and C-CMIS)
+        """
+        raise NotImplementedError
+
     def get_transceiver_vdm_real_value(self):
         """
         Retrieves VDM real (sample) values for this xcvr (applicable for CMIS and C-CMIS)

sonic_platform_base/sonic_xcvr/sfp_optoe_base.py

@@ -55,6 +55,10 @@ def is_coherent_module(self):
         api = self.get_xcvr_api()
         return api.is_coherent_module() if api is not None else None
 
+    def is_transceiver_vdm_supported(self):
+        api = self.get_xcvr_api()
+        return api.is_transceiver_vdm_supported() if api is not None else None
+
     def get_transceiver_vdm_real_value(self):
         """
         Retrieves VDM real (sample) values for this xcvr (applicable for CMIS and C-CMIS)

tests/sonic_xcvr/test_cmis.py

@@ -1244,6 +1244,20 @@ def test_set_loopback_mode(self, input_param, mock_response, expected):
         result = self.api.set_loopback_mode(input_param[0], input_param[1])
         assert result == expected
 
+    def test_is_transceiver_vdm_supported_no_vdm(self):
+        self.api.vdm = None
+        assert self.api.is_transceiver_vdm_supported() == False
+
+    def test_is_transceiver_vdm_supported_true(self):
+        self.api.vdm = MagicMock()
+        self.api.xcvr_eeprom.read = MagicMock(return_value=1)
+        assert self.api.is_transceiver_vdm_supported() == True
+
+    def test_is_transceiver_vdm_supported_false(self):
+        self.api.vdm = MagicMock()
+        self.api.xcvr_eeprom.read = MagicMock(return_value=0)
+        assert self.api.is_transceiver_vdm_supported() == False
+
     @pytest.mark.parametrize("mock_response, expected",[
         (
             [

tests/sonic_xcvr/test_sfp_optoe_base.py

@@ -8,6 +8,7 @@
 from sonic_platform_base.sonic_xcvr.mem_maps.public.c_cmis import CCmisMemMap 
 from sonic_platform_base.sonic_xcvr.xcvr_eeprom import XcvrEeprom 
 from sonic_platform_base.sonic_xcvr.codes.public.cmis import CmisCodes 
+from sonic_platform_base.sonic_xcvr.api.public.sff8472 import Sff8472Api
 
 class TestSfpOptoeBase(object): 
 
@@ -19,7 +20,16 @@ class TestSfpOptoeBase(object):
     sfp_optoe_api = SfpOptoeBase() 
     ccmis_api = CCmisApi(eeprom) 
     cmis_api = CmisApi(eeprom) 
+    sff8472_api = Sff8472Api(eeprom)
 
+    def test_is_transceiver_vdm_supported_non_cmis(self):
+        self.sfp_optoe_api.get_xcvr_api = MagicMock(return_value=self.sff8472_api)
+        try:
+            self.sfp_optoe_api.is_transceiver_vdm_supported()
+        except NotImplementedError:
+            exception_raised = True
+        assert exception_raised
+
     @pytest.mark.parametrize("mock_response1, mock_response2, expected", [ 
         (0, cmis_api, 0), 
         (1, cmis_api, 1),