How to limit number of points that user can add through Geofield widget to Openlayers maps?
In the settings of the GeoField you'd like to limit the entry for, set Storage Options to 'Store each simple feature as a separate field.'
Then in Location field settings, you can set the limit to one.


Number 1 is important, as it will make sure that clicking on the map a second time, moves the point around, instead of creating new points.