[VOL-1460]

- Imported protobuf definitions from pyvoltha at
  https://gerrit.opencord.org/gitweb?p=pyvoltha.git, commit hash:
  944aee71301b8ddb211b6e51d685f56d5c4a911b

- Imported upstream Google API protos from
  https://github.com/googleapis/googleapis, commit hash:
  5a90fbea68ce4a6e87c20d2df10df5ecd88299ff

- Fixed `import` paths and directory heirarchy in protobuf definitions
  to be compatible with both python 2 and 3.

- Created Makefile scaffold to generate language-specific bindings for
  python and go

Change-Id: Idd6b6b985a5eae4c38d40dd07ae78744c09e37f5
diff --git a/protos/voltha_protos/common.proto b/protos/voltha_protos/common.proto
new file mode 100644
index 0000000..e3b6211
--- /dev/null
+++ b/protos/voltha_protos/common.proto
@@ -0,0 +1,122 @@
+syntax = "proto3";
+
+option go_package = "github.com/opencord/voltha-go/protos/common";
+
+package voltha;
+
+import "voltha_protos/yang_options.proto";
+
+// Convey a resource identifier
+message ID {
+    string id = 1;
+}
+
+// Represents a list of IDs
+message IDs {
+    repeated ID items = 1;
+}
+
+enum TestModeKeys {
+    api_test=0;
+}
+
+message LogLevel {
+    option (yang_child_rule) = MOVE_TO_PARENT_LEVEL;
+
+    // Logging verbosity level
+    enum LogLevel {
+        DEBUG = 0;
+        INFO = 1;
+        WARNING = 2;
+        ERROR = 3;
+        CRITICAL = 4;
+        FATAL = 5;
+    }
+}
+
+message AdminState {
+    option (yang_child_rule) = MOVE_TO_PARENT_LEVEL;
+
+    // Administrative State
+    enum AdminState {
+
+        // The administrative state of the device is unknown
+        UNKNOWN = 0;
+
+        // The device is pre-provisioned into Voltha, but not contacted by it
+        PREPROVISIONED = 1;
+
+        // The device is enabled for activation and operation
+        ENABLED = 2;
+
+        // The device is disabled and shall not perform its intended forwarding
+        // functions other than being available for re-activation.
+        DISABLED = 3;
+
+        // The device is in the state of image download
+        DOWNLOADING_IMAGE = 4;
+
+        // The device is marked to be deleted
+        DELETED = 5;
+    }
+}
+
+message OperStatus {
+    option (yang_child_rule) = MOVE_TO_PARENT_LEVEL;
+
+    // Operational Status
+    enum OperStatus {
+
+        // The status of the device is unknown at this point
+        UNKNOWN = 0;
+
+        // The device has been discovered, but not yet activated
+        DISCOVERED = 1;
+
+        // The device is being activated (booted, rebooted, upgraded, etc.)
+        ACTIVATING = 2;
+
+        // Service impacting tests are being conducted
+        TESTING = 3;
+
+        // The device is up and active
+        ACTIVE = 4;
+
+        // The device has failed and cannot fulfill its intended role
+        FAILED = 5;
+    }
+}
+
+message ConnectStatus {
+    option (yang_child_rule) = MOVE_TO_PARENT_LEVEL;
+
+    // Connectivity Status
+    enum ConnectStatus {
+
+        // The device connectivity status is unknown
+        UNKNOWN = 0;
+
+        // The device cannot be reached by Voltha
+        UNREACHABLE = 1;
+
+        // There is live communication between device and Voltha
+        REACHABLE = 2;
+    }
+}
+
+message OperationResp {
+    option (yang_child_rule) = MOVE_TO_PARENT_LEVEL;
+
+    enum OperationReturnCode {
+        OPERATION_SUCCESS = 0;
+        OPERATION_FAILURE = 1;
+        OPERATION_UNSUPPORTED = 2;
+    }
+    // Return code
+    OperationReturnCode code = 1;
+
+    // Additional Info
+    string additional_info = 2;
+}
+
+