[ycable] add definitions of some new API's for Y-Cable infrastructure (sonic-net#301)

Signed-off-by: vaibhav-dahiya vdahiya@microsoft.com
This PR adds the following API's useful for muxcable MCU's debug, these are added as base class for muxcable API's and implemented by vendor

    def queue_info(self):

        This API should dump all the meaningful data from the eeprom which can
        help vendor debug the queue info currently relevant to the MCU
        using this API the vendor could check how many txns are currently in the queue etc
        for debugging purpose
    def reset_cause(self):

        This API should return the reset cause for the NIC MCU.
        This should help ascertain whether a reset was caused by soft reboot or
        cable poweroff
    def operation_time(self):
        This API should return the time since the cable is powered on from NIC MCU side
        This should be helpful in debugging purposes as to if/when the cable has been powered on
    def mem_read(self):

        This API should return the memory contents/as well as pointers/counters for DMA or hardware 
        FIFO's which could be useful for debugging the state of the MCU

Author: vdahiya12

sonic_y_cable/y_cable_base.py

@@ -1167,3 +1167,133 @@ def debug_dump_registers(self, option=None):
         """
 
         raise NotImplementedError
+
+    def queue_info(self):
+        """
+        This API should dump all the meaningful data from the eeprom which can
+        help vendor debug the queue info for the UART stats in particular
+        currently relevant to the MCU
+        using this API the vendor could check how many txns are currently waiting to be processed,proceessed
+        in the queue etc for debugging purposes
+
+        Args:
+             None
+
+        Returns:
+            a Dictionary:
+                 with all the relevant key-value pairs for all the meaningful fields
+                 for the queue inside the MCU firmware
+                 which would help diagnose the cable for proper functioning
+        """
+
+        raise NotImplementedError
+
+    def reset_cause(self):
+        """
+        This API should return the reset cause for the NIC MCU.
+        This should help ascertain whether a reset was caused by soft reboot or
+        cable poweroff
+
+        Args:
+             None
+
+        Returns:
+            a string:
+                 the string should be self explnatory as to what was the cause of reset
+
+        """
+        raise NotImplementedError
+
+    def operation_time(self):
+        """
+        This API should return the time since the cable is powered on from NIC MCU side
+        This should be helpful in debugging purposes as to if/when the cable has been powered on
+
+        Args:
+             None
+
+        Returns:
+            a float:
+                 the float should represent how much time the mux cable is alive/powered on
+        """
+
+        raise NotImplementedError
+
+    def mem_read(self, target, addr, length):
+        """
+        This API should return the memory contents of the cable which would be useful in debug for the
+        y-cable
+
+        Args:
+             target:
+                 local (TOR) or remote (NIC) MCU
+             addr:
+                 the starting address of the MCU's memory space
+             length:
+                 length to be read, unit: byte
+
+        Returns:
+            a Bytearray:
+                 the contents of the memory inside the MCU firmware
+                 which would help diagnose the cable for proper functioning
+        """
+
+        raise NotImplementedError
+
+    def activate_target_firmware(self, target, fwfile=None, hitless=False):
+        """
+        This routine should activate the downloaded firmware on all the target
+        of the Y cable of the port for which this API is called..
+        This API is meant to be used in conjunction with download_firmware API, and
+        should be called once download_firmware API is succesful.
+        This means that the firmware which has been downloaded should be
+        activated (start being utilized by the cable) once this API is
+        successfully executed.
+        The port on which this API is called for can be referred using self.port.
+
+        Args:
+            target:
+                One of the following predefined constants, the actual target to activate the firmware on:
+                     TARGET_NIC -> NIC,
+                     TARGET_TOR_A -> TORA,
+                     TARGET_TOR_B -> TORB
+            fwfile (optional):
+                 a string, a path to the file which contains the firmware image.
+                 Note that the firmware file can be in the format of the vendor's
+                 choosing (binary, archive, etc.). But note that it should be one file
+                 which contains firmware for all components of the Y-cable. In case the
+                 vendor chooses to pass this file in activate_firmware, the API should
+                 have the logic to retreive the firmware version from this file
+                 which has to be activated on the components of the Y-Cable
+                 this API has been called for.
+                 If None is passed for fwfile, the cable should activate whatever
+                 firmware is marked to be activated next.
+                 If provided, it should retreive the firmware version(s) from this file, ensure
+                 they are downloaded on the cable, then activate them.
+
+            hitless (optional):
+                a boolean, True, Hitless upgrade: it will backup/restore the current state
+                                 (ex. variables of link status, API attributes...etc.) before
+                                 and after firmware upgrade.
+                a boolean, False, Non-hitless upgrade: it will update the firmware regardless
+                                  the current status, a link flip can be observed during the upgrade.
+        Returns:
+            One of the following predefined constants:
+                FIRMWARE_ACTIVATE_SUCCESS
+                FIRMWARE_ACTIVATE_FAILURE
+        """
+
+        raise NotImplementedError
+
+    def health_check(self):
+        """
+        This API checks the health of the cable, where it is healthy/unhealythy for RMA purposes/diagnostics.
+        The port on which this API is called for can be referred using self.port.
+
+        Args:
+
+        Returns:
+            a Boolean, True if the cable is healthy and False if it is not healthy.
+        """
+
+        raise NotImplementedError