API visibility of location data

hi there, i’ve set up geomashup to enable a custom post type to have location data assigned, and i’m able to show maps on the front end, all good.
one thing – we’re also trying to pump the location data to a mobile app via the REST API. i’ve got various other fields working to the API (including some other plug-in specific fields and custom fields), but am drawing a blank as to how to make the location information visible via the API. any ideas/suggestions? we ideally want LONG and LAT (which i can see in post editor).

i’m using https://wordpress.org/plugins/wp-rest-api-controller/ to give me a UI for controlling which fields are made available to the API, but could equally add something to the functions.php file to specifically show the location field/long/lat etc from geomashup.

thanks!