On Sun, Mar 09, 2025 at 09:52:38AM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote: > On Sun, Mar 09, 2025 at 08:40:31AM +0000, Aditya Garg wrote: > > From: Paul Pawlowski <paul@xxxxxxxx> > > > > This patch adds a driver named apple-bce, to add support for the T2 > > Security Chip found on certain Macs. > > > > The driver has 3 main components: > > > > BCE (Buffer Copy Engine) - this is what the files in the root directory > > are for. This estabilishes a basic communication channel with the T2. > > VHCI and Audio both require this component. > > So this is a new "bus" type? Or a platform resource? Or something > else? > > > VHCI - this is a virtual USB host controller; keyboard, mouse and > > other system components are provided by this component (other > > drivers use this host controller to provide more functionality). > > I don't understand, why does a security chip have a USB virtual > interface in it? What "devices" hang off of it that are found and > enumerated by the host OS? > > And what other drivers use this controller, just normal Linux drivers, > or vendor-specific ones? > > > Audio - a driver for the T2 audio interface, currently only audio > > output is supported. > > Again, is this a platform device or does it sit on the BCE "bus" you > will create here? Also, it looks like you are creating some new user/kernel apis here (i.e. a char device for a USB host controller?) So those need to be explained a lot as to what they are for and who is using them as I really don't understand their need, nor know what userspace code controls them. thanks, greg k-h
