The PS5 DualSense now has official support on Steam

Steam reported that the control of the PlayStation 5, the DualSense, already has official support from the platform to be used without any problem. Thanks to the arrival of support for this controller, PS5 users who also have the Valve platform on their PCs will be able to use it although they will not be able to experience the technology that exists in it, such as haptic controls and adaptive triggers, although It lends itself as a second option, aside from DualShock 4, to play the once-exclusive PS4 titles that are now on Steam, such as Horizon: Zero Dawn.

In that sense, the official Steam site refers to the following regarding support for DualSense:

Flawless player experience with the correct glyphs for all devices, including any remapping
Support for advanced features such as motion controls, touch panels, or additional buttons
The updates just work. When new features and / or devices are added to the API, they “just work” with the games that use them, without requiring additional work from the developers.