Add set/get_lpmode APIs for sff8436 and sff8636 optics (sonic-net#353)

* Add lpmode APIs for sff8436 and sff8636

* Update comments

* Simplify set_lpmode logic

* Update docstring

* Update docstring to lpmode on/off

sonic_platform_base/sonic_xcvr/api/public/sff8436.py

@@ -308,3 +308,35 @@ def get_lpmode_support(self):
 
     def get_power_override_support(self):
         return not self.is_copper()
+
+    def set_lpmode(self, lpmode):
+        '''
+        This function sets LPMode for the module.
+
+        Args:
+            lpmode (bool): False means LPMode Off, True means LPMode On
+
+        Returns:
+            bool: True if the provision succeeds, False if it fails
+        '''
+        if not self.get_lpmode_support() or not self.get_power_override_support():
+            return False
+
+        return self.set_power_override(True, lpmode)
+
+    def get_lpmode(self):
+        '''
+        Retrieves low power mode status
+
+        Returns:
+            bool: True if module in low power else returns False.
+        '''
+        if not self.get_lpmode_support() or not self.get_power_override_support():
+            return False
+
+        power_set = self.get_power_set()
+        power_override = self.get_power_override()
+
+        # Since typically optics come up by default set to high power, in this case,
+        # power_override not being set, function will return high power mode.
+        return power_set and power_override

sonic_platform_base/sonic_xcvr/api/public/sff8636.py

@@ -360,3 +360,35 @@ def get_lpmode_support(self):
 
     def get_power_override_support(self):
         return not self.is_copper()
+
+    def set_lpmode(self, lpmode):
+        '''
+        This function sets LPMode for the module.
+
+        Args:
+            lpmode (bool): False means LPMode Off, True means LPMode On
+
+        Returns:
+            bool: True if the provision succeeds, False if it fails
+        '''
+        if not self.get_lpmode_support() or not self.get_power_override_support():
+            return False
+
+        return self.set_power_override(True, lpmode)
+
+    def get_lpmode(self):
+        '''
+        Retrieves low power mode status
+
+        Returns:
+            bool: True if module in low power else returns False.
+        '''
+        if not self.get_lpmode_support() or not self.get_power_override_support():
+            return False
+
+        power_set = self.get_power_set()
+        power_override = self.get_power_override()
+
+        # Since typically optics come up by default set to high power, in this case,
+        # power_override not being set, function will return high power mode.
+        return power_set and power_override

tests/sonic_xcvr/test_sff8436.py

@@ -54,6 +54,8 @@ def test_api(self):
         self.api.get_transceiver_thresholds_support()
         self.api.get_lpmode_support()
         self.api.get_power_override_support()
+        self.api.set_lpmode(True)
+        self.api.get_lpmode()
 
     @pytest.mark.parametrize("mock_response, expected", [
         (bytearray([0x0]), "Power Class 1 Module (1.5W max. Power consumption)"),
@@ -104,3 +106,32 @@ def test_simulate_copper(self):
             assert not self.api.get_temperature_support()
             assert not self.api.get_voltage_support()
 
+    def test_get_lpmode(self):
+        self.api.get_lpmode_support = MagicMock()
+        self.api.get_lpmode_support.return_value = True
+        self.api.get_power_override_support = MagicMock()
+        self.api.get_power_override_support.return_value = True
+        self.api.get_power_set = MagicMock()
+        self.api.get_power_set.return_value = True
+        self.api.get_power_override = MagicMock()
+        self.api.get_power_override.return_value = True
+        assert self.api.get_lpmode()
+        self.api.get_power_set.return_value = False
+        self.api.get_power_override.return_value = True
+        assert not self.api.get_lpmode()
+        self.api.get_lpmode_support.return_value = False
+        self.api.get_power_override_support.return_value = False
+        assert not self.api.get_lpmode()
+
+    def test_set_lpmode(self):
+        self.api.get_lpmode_support = MagicMock()
+        self.api.get_lpmode_support.return_value = True
+        self.api.get_power_override_support = MagicMock()
+        self.api.get_power_override_support.return_value = True
+        self.api.set_power_override = MagicMock()
+        self.api.set_power_override.return_value = True
+        assert self.api.set_lpmode(True)
+        assert self.api.set_lpmode(False)
+        self.api.get_lpmode_support.return_value = False
+        self.api.get_power_override_support.return_value = False
+        assert not self.api.set_lpmode(True)

tests/sonic_xcvr/test_sff8636.py

@@ -54,6 +54,8 @@ def test_api(self):
         self.api.get_transceiver_thresholds_support()
         self.api.get_lpmode_support()
         self.api.get_power_override_support()
+        self.api.set_lpmode(True)
+        self.api.get_lpmode()
 
     @pytest.mark.parametrize("mock_response, expected", [
         (bytearray([0x0]), "Power Class 1 Module (1.5W max.)"),
@@ -105,3 +107,33 @@ def test_simulate_copper(self):
             assert not self.api.get_temperature_support()
             assert not self.api.get_voltage_support()
 
+    def test_get_lpmode(self):
+        self.api.get_lpmode_support = MagicMock()
+        self.api.get_lpmode_support.return_value = True
+        self.api.get_power_override_support = MagicMock()
+        self.api.get_power_override_support.return_value = True
+        self.api.get_power_set = MagicMock()
+        self.api.get_power_set.return_value = True
+        self.api.get_power_override = MagicMock()
+        self.api.get_power_override.return_value = True
+        assert self.api.get_lpmode()
+        self.api.get_power_set.return_value = False
+        self.api.get_power_override.return_value = True
+        assert not self.api.get_lpmode()
+        self.api.get_lpmode_support.return_value = False
+        self.api.get_power_override_support.return_value = False
+        assert not self.api.get_lpmode()
+
+    def test_set_lpmode(self):
+        self.api.get_lpmode_support = MagicMock()
+        self.api.get_lpmode_support.return_value = True
+        self.api.get_power_override_support = MagicMock()
+        self.api.get_power_override_support.return_value = True
+        self.api.set_power_override = MagicMock()
+        self.api.set_power_override.return_value = True
+        assert self.api.set_lpmode(True)
+        assert self.api.set_lpmode(False)
+        self.api.get_lpmode_support.return_value = False
+        self.api.get_power_override_support.return_value = False
+        assert not self.api.set_lpmode(True)
+