Swagger for FTP endpoints

We are working with a number of legacy systems that still sends and receives information via FTP. We have put in place transformations to move these FTP sites and migrate them into S3 buckets in AWS. However, the FTP locations will still need to exist for the immediate future. We want to document these locations and provide information such server address, directory location, protocol, file extensions accepted, file formating, etc. My hope is to use render doc to generate Swagger files but in a way that allows the fitting of FTP instead of just REST calls. The desire is we want to keep an online documentation for the old style of FTP locations and the new style of REST endpoints together in one place. Anyway, I have searched and haven't found much out there trying to do similar. Is Swagger flexible enough to handle this similar but different type of endpoint? If so, suggestions on where to start would be great.