Re: Polymorphic devices

On Fri, 5 Jan 2024, Brad Spencer wrote:

> I see a few options for doing this, such as simply matching all of the
> possible children and using sysctl to enable the one you want.  Probably
> followed by a rescan call.  That seems ugly, however.  The use of
> 'drvctl -r -a <attribute>' seemed to hold promise.  It seems like a
> better idea to require the detachment of whatever followed by the rescan
> with the attribute indicating which sort of thing you wanted to attach
> (detach ucom in favor of i2c, for example).  But I do not completely
> understand if this sort of thing is possible.

I don't see why it shouldn't be.. you attach your main driver as a bus, 
then send it a message as to what configuration you need, then it 
essentially rescans and finds and attaches or detaches sub-drivers as 
appropriate.

I did this sort of thing in software with bthub(4)

iain