Fix Javadoc warnings

Change-Id: Icf8b6b6f77ea80d3975aa975226a178145067adf
diff --git a/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OduCltPortHelper.java b/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OduCltPortHelper.java
index 380b8fe..b3d2905 100644
--- a/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OduCltPortHelper.java
+++ b/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OduCltPortHelper.java
@@ -55,6 +55,7 @@
      * @param number        port number
      * @param isEnabled     port enabled state
      * @param signalType    ODU client signal type
+     * @return              port description
      */
     public static PortDescription oduCltPortDescription(PortNumber number,
                                         boolean isEnabled,
@@ -69,6 +70,7 @@
      * @param isEnabled     port enabled state
      * @param signalType    ODU client signal type
      * @param annotations   key/value annotations map
+     * @return              port description
      */
     public static PortDescription oduCltPortDescription(PortNumber number,
                                                         boolean isEnabled,
@@ -93,6 +95,7 @@
      * @param base          PortDescription to get basic information from
      * @param signalType    ODU client signal type
      * @param annotations   key/value annotations map
+     * @return              port description
      */
     public static PortDescription oduCltPortDescription(PortDescription base,
                                                         CltSignalType signalType,
diff --git a/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OmsPortHelper.java b/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OmsPortHelper.java
index f0d878d..2d83aa2 100644
--- a/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OmsPortHelper.java
+++ b/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OmsPortHelper.java
@@ -66,6 +66,7 @@
      * @param maxFrequency  maximum frequency
      * @param grid          grid spacing frequency
      * @param annotations   key/value annotations map
+     * @return              port description
      */
     public static PortDescription omsPortDescription(PortNumber number,
                                               boolean isEnabled,
@@ -93,6 +94,7 @@
      * @param minFrequency  minimum frequency
      * @param maxFrequency  maximum frequency
      * @param grid          grid spacing frequency
+     * @return              port description
      */
     public static PortDescription omsPortDescription(PortNumber number,
                                               boolean isEnabled,
@@ -110,6 +112,7 @@
      * @param maxFrequency  maximum frequency
      * @param grid          grid spacing frequency
      * @param annotations   key/value annotations map
+     * @return              port description
      */
     public static PortDescription omsPortDescription(PortDescription base,
                                               Frequency minFrequency,
diff --git a/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OtuPortHelper.java b/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OtuPortHelper.java
index 968dd6b..80263d4 100644
--- a/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OtuPortHelper.java
+++ b/apps/optical-model/src/main/java/org/onosproject/net/optical/device/OtuPortHelper.java
@@ -55,6 +55,7 @@
      * @param number        port number
      * @param isEnabled     port enabled state
      * @param signalType    OTU client signal type
+     * @return              port description
      */
     public static PortDescription otuPortDescription(PortNumber number,
                                                      boolean isEnabled,
@@ -69,6 +70,7 @@
      * @param isEnabled     port enabled state
      * @param signalType    OTU client signal type
      * @param annotations   key/value annotations map
+     * @return              port description
      */
     public static PortDescription otuPortDescription(PortNumber number,
                                                      boolean isEnabled,
@@ -93,6 +95,7 @@
      * @param base          PortDescription to get basic information from
      * @param signalType    OTU client signal type
      * @param annotations   key/value annotations map
+     * @return              port description
      */
     public static PortDescription otuPortDescription(PortDescription base,
                                                      OtuSignalType signalType,
diff --git a/apps/optical-model/src/main/java/org/onosproject/net/optical/device/port/PortMapper.java b/apps/optical-model/src/main/java/org/onosproject/net/optical/device/port/PortMapper.java
index 90da7ae..f2a15781 100644
--- a/apps/optical-model/src/main/java/org/onosproject/net/optical/device/port/PortMapper.java
+++ b/apps/optical-model/src/main/java/org/onosproject/net/optical/device/port/PortMapper.java
@@ -32,6 +32,9 @@
 
     /**
      * Returns true if this port is capable of being projected as {@code <P>}.
+     *
+     * @param port port
+     * @return true if this port can be projected as the given type
      */
     boolean is(Port port);
 
diff --git a/apps/optical-model/src/main/java/org/onosproject/net/optical/json/OchSignalCodec.java b/apps/optical-model/src/main/java/org/onosproject/net/optical/json/OchSignalCodec.java
index 0fba4fa..08d4155 100644
--- a/apps/optical-model/src/main/java/org/onosproject/net/optical/json/OchSignalCodec.java
+++ b/apps/optical-model/src/main/java/org/onosproject/net/optical/json/OchSignalCodec.java
@@ -76,6 +76,7 @@
     /**
      * Returns a JSON Object representation of this instance.
      *
+     * @param j Och signal object
      * @return JSON Object representing OchSignal
      */
     public static ObjectNode encode(OchSignal j) {