Please consult Unix manual and source code (for instance any of the BSD). Linux was never a reference in Unix world, it was about to mimic Unix, but was not even self-compatible. Not a good reference point. See how big mess it introduced in current drivers implementation (i.e. drm kms) and their propagation to other OS. Is this similar situation here?
Device driver should not provide any additional processing / silent rewrite of data, just provide raw data, that is then processed by the application. Driver may be configured by ioctl/sysclt, to enable additional / specific behavior (i.e. debug, buffer size, latency, etc), so the user always knows exactly what the driver does. I am pro Greg approach, so driver is always simple and generic, everything else is up to application. This is the Unix way and you will know how most things work, because they all work the same generic standardized way, as simple as possible, nothing else happens "in the background unnoticed". If a specific device needs a specific handling by a generic driver, then "quirks" may be used. That explicitly mark "specific" behavior for a given device (and only this device). -- CeDeROM, SQ7MHZ, http://www.tomek.cedro.info
