grails doc and javadoc creation

Using grails 2.1.1, I have java source code in a folder called grails-app/lcs/src/java/, required no special configuration to add this to the build. But "grails doc" generates no javadoc output in the target/docs/api folder.

Documentation on this is sparse- how do i configure this in grails?
thanks,
--michael

$ grailsw doc
| Compiling 250 source files

| Built user manual at /Users/moores/expedia/v2/www/services/hotels/datafeed/hotelsimport-service/trunk/target/docs/index.html

$ cd target/docs
$ ls
all-docs.html api css gapi guide img index.html js ref
$ ls api/
$