sonic-port.yang: add link training support (#10025)

This is part of HLD  Azure/SONiC#925

#### Why I did it
Add link-training support

#### How I did it
Update SONiC YANG for port link-training support

#### Description for the changelog
Add "link_training" to sonic-port.yang

#### Link to config_db schema for YANG module changes

https://github.com/sonic-net/SONiC/wiki/Configuration#port

src/sonic-yang-models/doc/Configuration.md

@@ -1167,7 +1167,8 @@ optional attributes.
             "description": "fortyGigE1/1/1",
             "mtu": "9100",
             "alias": "fortyGigE1/1/1",
-            "speed": "40000"
+            "speed": "40000",
+            "link_training": "off"
         },
         "Ethernet1": {
             "index": "1",
@@ -1176,7 +1177,8 @@ optional attributes.
             "mtu": "9100",
             "alias": "fortyGigE1/1/2",
             "admin_status": "up",
-            "speed": "40000"
+            "speed": "40000",
+            "link_training": "on"
         },
         "Ethernet63": {
             "index": "63",

src/sonic-yang-models/tests/files/sample_config_db.json

@@ -438,7 +438,8 @@
                 "index": "0",
                 "asic_port_name": "Eth0-ASIC1",
                 "role": "Ext",
-                "macsec": "test"
+                "macsec": "test",
+                "link_training": "off"
             },
             "Ethernet1": {
                 "alias": "Eth1/2",
@@ -449,7 +450,8 @@
                 "admin_status": "up",
                 "autoneg": "on",
                 "adv_speeds": "100000,50000",
-                "adv_interface_types": "CR,CR4"
+                "adv_interface_types": "CR,CR4",
+                "link_training": "on"
             },
             "Ethernet2": {
                 "alias": "Eth1/3",

src/sonic-yang-models/tests/yang_model_tests/tests/port.json

@@ -69,6 +69,17 @@
         "desc": "PORT_INVALID_ADVTYPES_TEST_2 must condition failure.",
         "eStrKey" : "Must"
     },
+    "PORT_VALID_LINK_TRAINING_TEST_1": {
+        "desc": "PORT_VALID_LINK_TRAINING_TEST_1 no failure."
+    },
+    "PORT_VALID_LINK_TRAINING_TEST_2": {
+        "desc": "PORT_VALID_LINK_TRAINING_TEST_2 no failure."
+    },
+    "PORT_INVALID_LINK_TRAINING_TEST": {
+        "desc": "PORT_INVALID_LINK_TRAINING_TEST must condition failure.",
+        "eStrKey" : "Pattern",
+        "eStr": ["on|off"]
+    },
     "PORT_INVALID_TPID_TEST": {
         "desc": "PORT_INVALID_TPID_TEST invalid tpid value failure.",
         "eStrKey" : "Pattern",

src/sonic-yang-models/tests/yang_model_tests/tests_config/port.json

@@ -311,6 +311,57 @@
         }
     },
 
+    "PORT_VALID_LINK_TRAINING_TEST_1": {
+        "sonic-port:sonic-port": {
+            "sonic-port:PORT": {
+                "PORT_LIST": [
+                    {
+                        "name": "Ethernet8",
+                        "alias": "eth8",
+                        "lanes": "65",
+                        "speed": 25000,
+                        "tpid": "0x8100",
+                        "link_training": "on"
+                    }
+                ]
+            }
+        }
+    },
+
+    "PORT_VALID_LINK_TRAINING_TEST_2": {
+        "sonic-port:sonic-port": {
+            "sonic-port:PORT": {
+                "PORT_LIST": [
+                    {
+                        "name": "Ethernet8",
+                        "alias": "eth8",
+                        "lanes": "65",
+                        "speed": 25000,
+                        "tpid": "0x8100",
+                        "link_training": "off"
+                    }
+                ]
+            }
+        }
+    },
+
+    "PORT_INVALID_LINK_TRAINING_TEST": {
+        "sonic-port:sonic-port": {
+            "sonic-port:PORT": {
+                "PORT_LIST": [
+                    {
+                        "name": "Ethernet8",
+                        "alias": "eth8",
+                        "lanes": "65",
+                        "speed": 25000,
+                        "tpid": "0x8100",
+                        "link_training": 0
+                    }
+                ]
+            }
+        }
+    },
+
     "PORT_INVALID_TPID_TEST": {
         "sonic-port:sonic-port": {
             "sonic-port:PORT": {

src/sonic-yang-models/yang-models/sonic-port.yang

@@ -65,6 +65,14 @@ module sonic-port{
 					}
 				}
 
+				leaf link_training {
+					description "Port link training mode";
+
+					type string {
+						pattern "on|off";
+					}
+				}
+
 				leaf autoneg {
 					description "Port auto negotiation mode";