Photoshop :: Establish Non-destructive Saturation (ceiling) Level?

Is there any way to put a non-destructive cap on color saturation, the way you can shelf frequencies above or below a certain level in audio engineering?
 
In other words, an adjustment layer that would limit all saturation values over X to.. well.. X.
 
Example : Let's say we set it to 80% max. Pixels with saturation levels of 80 or below remain untouched. Pixels with saturation levels over 80 are re-adjusted to 80.
 
(Simply lowering the saturation levels via an adjustment layer will lower everything, including portions that are already below the desired cap. We don't want that.)