[xcvrd] support for integrating Credo Y cable Ports initialization an…

…d status updates with xcvrd. (sonic-net#105)

* [xcvrd] support for integrating y cable within xcvrd

This PR provides the necessary infrastructure to initialize the Y cable Ports inside SONIC with xcvrd as the platform daemon.
Particularly there are two parts of integration:

While xcvrd initializes , there is within config_db for Y cable presence. This is done by checking the key-value pairs for
presence of mux_cable identifier as a key. Once a Y cable is found to be attached to a port, State DB is updated with
the corresponding data for the Y cable Port.

Once the init process is done, and a Y cable presence is established, A thread is run to periodically monitor changes
to APPL DB MUX_CABLE_COMMAND table for updates, and also one that periodically checks for a change events,  If an update is found, the corresponding changes are done on MUX using
sonic_y_cable package and corresponding changes are updated in STATE_DB

What is the motivation for this PR?
To add the necessary infrastructure for Credo Y cable integration within SONIC

How did you do it?
Added the necessary changes and a new xcvrd_utilities sub directory for utilities of y_cable code.
Reorganized the setup.py and sonix-xcvrd code to this form

sonic-xcvrd/setup.py
sonic-xcvrd/src/init.py
sonic-xcvrd/scripts/xcvrd → sonic-xcvrd/src/xcvrd.py
sonic-xcvrd/src/xcvrd_utilities/init.py
sonic-xcvrd/src/xcvrd_utilities/y_cable_helper.py

Signed-off-by: vaibhav-dahiya <vdahiya@microsoft.com>

sonic-xcvrd/setup.py

@@ -10,9 +10,11 @@
     url = 'https://github.com/Azure/sonic-platform-daemons',
     maintainer = 'Kebo Liu',
     maintainer_email = 'kebol@mellanox.com',
-    scripts = [
-        'scripts/xcvrd',
-    ],
+    entry_points = {
+        'console_scripts': [
+            'xcvrd = src.xcvrd:main',
+        ]
+    },
     install_requires = [
         # NOTE: This package also requires swsscommon, but it is not currently installed as a wheel
         'enum34; python_version < "3.4"',

sonic-xcvrd/scripts/xcvrd → sonic-xcvrd/src/xcvrd.py

@@ -20,6 +20,8 @@
     from sonic_py_common import daemon_base, device_info, logger
     from sonic_py_common import multi_asic
     from swsscommon import swsscommon
+
+    from .xcvrd_utilities import y_cable_helper
 except ImportError, e:
     raise ImportError (str(e) + " - required module not found")
 
@@ -854,7 +856,7 @@ def _mapping_event_from_change_event(self, status, port_dict):
         helper_logger.log_debug("mapping from {} {} to {}".format(status, port_dict, event))
         return event
 
-    def task_worker(self, stopping_event, sfp_error_event):
+    def task_worker(self, stopping_event, sfp_error_event, y_cable_presence):
         helper_logger.log_info("Start SFP monitoring loop")
 
         transceiver_dict = {}
@@ -1042,6 +1044,9 @@ def task_worker(self, stopping_event, sfp_error_event):
                                 # SFP return unkown event, just ignore for now.
                                 helper_logger.log_warning("Got unknown event {}, ignored".format(value))
                                 continue
+
+                    # Since ports could be connected to a mux cable, if there is a change event process the change for being on a Y cable Port
+                    y_cable_helper.change_ports_status_for_y_cable_change_event(port_dict, y_cable_presence, stopping_event)      
                 else:
                     next_state = STATE_EXIT
             elif event == SYSTEM_FAIL:
@@ -1079,11 +1084,11 @@ def task_worker(self, stopping_event, sfp_error_event):
 
         helper_logger.log_info("Stop SFP monitoring loop")
 
-    def task_run(self, sfp_error_event):
+    def task_run(self, sfp_error_event, y_cable_presence):
         if self.task_stopping_event.is_set():
             return
 
-        self.task_process = multiprocessing.Process(target=self.task_worker,args=(self.task_stopping_event, sfp_error_event))
+        self.task_process = multiprocessing.Process(target=self.task_worker,args=(self.task_stopping_event, sfp_error_event, y_cable_presence))
         self.task_process.start()
 
     def task_stop(self):
@@ -1102,6 +1107,7 @@ def __init__(self, log_identifier):
         self.num_asics = multi_asic.get_num_asics()
         self.stop_event = threading.Event()
         self.sfp_error_event = multiprocessing.Event()
+        self.y_cable_presence = [False]
 
     # Signal handler
     def signal_handler(self, sig, frame):
@@ -1231,6 +1237,9 @@ def init(self):
         self.log_info("Init port sfp status table")
         init_port_sfp_status_tbl(self.stop_event)
 
+        # Init port y_cable status table
+        y_cable_helper.init_ports_status_for_y_cable(platform_sfputil, platform_chassis, self.y_cable_presence, self.stop_event)
+
     # Deinitialize daemon
     def deinit(self):
         self.log_info("Start daemon deinit...")
@@ -1247,6 +1256,10 @@ def deinit(self):
             del_port_sfp_dom_info_from_db(logical_port_name, self.int_tbl[asic_index], self.dom_tbl[asic_index])
             delete_port_from_status_table(logical_port_name, self.status_tbl[asic_index])
 
+        if self.y_cable_presence[0] is True:
+            y_cable_helper.delete_ports_status_for_y_cable()
+
+
     # Run daemon
     def run(self):
         self.log_info("Starting up...")
@@ -1260,7 +1273,13 @@ def run(self):
 
         # Start the sfp state info update process
         sfp_state_update = SfpStateUpdateTask()
-        sfp_state_update.task_run(self.sfp_error_event)
+        sfp_state_update.task_run(self.sfp_error_event, self.y_cable_presence)
+
+        # Start the Y-cable state info update process if Y cable presence established
+        y_cable_state_update = None
+        if self.y_cable_presence[0] is True:
+            y_cable_state_update = y_cable_helper.YCableTableUpdateTask()
+            y_cable_state_update.task_run()
 
         # Start main loop
         self.log_info("Start daemon main loop")
@@ -1277,6 +1296,10 @@ def run(self):
         # Stop the sfp state info update process
         sfp_state_update.task_stop()
 
+        # Stop the Y-cable state info update process
+        if self.y_cable_presence[0] is True:
+            y_cable_state_update.task_stop()
+
         # Start daemon deinitialization sequence
         self.deinit()
 
@@ -1289,6 +1312,7 @@ def run(self):
 # Main =========================================================================
 #
 
+# This is our main entry point for xcvrd script
 def main():
     xcvrd = DaemonXcvrd(SYSLOG_IDENTIFIER)
     xcvrd.run()