[sonic_platform/sfp_base] Add common definition for get SFP error sta…

…tus (sonic-net#194)

Add common definitions for getting SFP error status

- Platform API definition: `get_sfp_status`
- Related constant definitions

Signed-off-by: Stephen Sun <stephens@nvidia.com>

sonic_platform_base/sfp_base.py

@@ -16,6 +16,41 @@ class SfpBase(device_base.DeviceBase):
     # Device type definition. Note, this is a constant.
     DEVICE_TYPE = "sfp"
 
+    # Generic error types definition
+    SFP_STATUS_INITIALIZING                         = 'Initializing'
+    SFP_STATUS_OK                                   = 'OK'
+    SFP_STATUS_UNPLUGGED                            = 'Unplugged'
+    SFP_STATUS_DISABLED                             = 'Disabled'
+    SFP_ERROR_DESCRIPTION_BLOCKING                  = 'Blocking EEPROM from being read'
+    SFP_ERROR_DESCRIPTION_POWER_BUDGET_EXCEEDED     = 'Power budget exceeded'
+    SFP_ERROR_DESCRIPTION_I2C_STUCK                 = 'Bus stuck (I2C data or clock shorted)'
+    SFP_ERROR_DESCRIPTION_BAD_EEPROM                = 'Bad or unsupported EEPROM'
+    SFP_ERROR_DESCRIPTION_UNSUPPORTED_CABLE         = 'Unsupported cable'
+    SFP_ERROR_DESCRIPTION_HIGH_TEMP                 = 'High temperature'
+    SFP_ERROR_DESCRIPTION_BAD_CABLE                 = 'Bad cable (module/cable is shorted)'
+
+    # SFP status
+    SFP_STATUS_BIT_REMOVED                = 0x00000000
+    SFP_STATUS_BIT_INSERTED               = 0x00000001
+    # SFP error status
+    SFP_ERROR_BIT_BLOCKING                = 0x00000002
+    SFP_ERROR_BIT_POWER_BUDGET_EXCEEDED   = 0x00000004
+    SFP_ERROR_BIT_I2C_STUCK               = 0x00000008
+    SFP_ERROR_BIT_BAD_EEPROM              = 0x00000010
+    SFP_ERROR_BIT_UNSUPPORTED_CABLE       = 0x00000020
+    SFP_ERROR_BIT_HIGH_TEMP               = 0x00000040
+    SFP_ERROR_BIT_BAD_CABLE               = 0x00000080
+
+    SFP_ERROR_BIT_TO_DESCRIPTION_DICT = {
+        SFP_ERROR_BIT_BLOCKING:                SFP_ERROR_DESCRIPTION_BLOCKING,
+        SFP_ERROR_BIT_POWER_BUDGET_EXCEEDED:   SFP_ERROR_DESCRIPTION_POWER_BUDGET_EXCEEDED,
+        SFP_ERROR_BIT_I2C_STUCK:               SFP_ERROR_DESCRIPTION_I2C_STUCK,
+        SFP_ERROR_BIT_BAD_EEPROM:              SFP_ERROR_DESCRIPTION_BAD_EEPROM,
+        SFP_ERROR_BIT_UNSUPPORTED_CABLE:       SFP_ERROR_DESCRIPTION_UNSUPPORTED_CABLE,
+        SFP_ERROR_BIT_HIGH_TEMP:               SFP_ERROR_DESCRIPTION_HIGH_TEMP,
+        SFP_ERROR_BIT_BAD_CABLE:               SFP_ERROR_DESCRIPTION_BAD_CABLE
+    }
+
     def __init__(self):
         # List of ThermalBase-derived objects representing all thermals
         # available on the SFP
@@ -384,4 +419,13 @@ def write_eeprom(self, offset, num_bytes, write_buffer):
         """
         raise NotImplementedError
 
+    def get_error_description(self):
+        """
+        Retrives the error descriptions of the SFP module
 
+        Returns:
+            String that represents the current error descriptions of vendor specific errors
+            In case there are multiple errors, they should be joined by '|',
+            like: "Bad EEPROM|Unsupported cable"
+        """
+        raise NotImplementedError