Data available for download in various formats on the HSL website

From the dataset abstract

A location-based summary of stops by line, compiled from HSL's GTFS data. The data describes the stops in HSL's operating area by line as points, with each individual stop appearing exactly as many times as there are lines that pass through it.

Data attributes and preview in HSL's website.

Data is available in the following formats:

• CSV
• Esri Shapefile (SHP)
• GeoJSON
• KML
• File geodatabase
• Excel
• GeoPackage
• SQLite Geodatabase

Source: Helsingin Seudun Liikenteen (HSL) pysäkit linjoittain