Do you have your own POI, you want to import in OSM? I never found a tool to do this work. In the past I created an Excel template to import POI, in OSM database and use JOSM as a bridge.
I have done a step further, I code a php script to easily format text POI file into osm format.
Script page view
How does it work?
Format your data in a csv file (text) as per the following example:
-3.6897821,40.4874481,"Cajero La Caixa"
Choose the category and subcategory. The drop-down lists will change accordingly to the prior selection. The minimum choices is latitude, longitude and name.
The original csv file will be deleted at the end of the process. In the case the process would interrupted the csv file will be destroyed within few minutes to leave the server space free.
I always use JOSM to check my data before importing them to OSM