Comment by unleaded
10 hours ago
There are two types of generic PS2 to usb adapters, the one designed for pc (usually has two ports) and the one designed for PS3. The PS2 to PS3 controller adapters work perfectly with the right drivers (DSHidMini on Windows).
Cool, didn't know that. I thought they've got rid of pressure sensitive buttons in PS3 already, not PS4. Thanks!
So apparently, to make pressure sensitive PS2 controller work in PCSX2, you need ShanWan PS2-to-PS3 adapter (or equivalent), DSHidMini, and set input mode to SDL. Since I lack both pieces of hardware, I can't test it myself. Or skip the middleman and get a PS3 controller, which is a better option anyway for several reasons.