On Wed, Dec 05, 2018 at 05:32:19PM -0500, Sven Van Asbroeck wrote: > Thanks :) > > On Wed, Dec 5, 2018 at 2:17 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > Great, then call it a 'fieldbus' class, not "fieldbus_dev' class. > > Small nit: > > Hardware connected to a fieldbus comes in two distinct flavours: > - clients (e.g. thermometer, robotic arm) called "fieldbus devices" > - servers (e.g. a PLC) called "fieldbus controllers" > > Their userspace APIs will probably differ quite a lot. But servers are going to be much more rare, and odds are userspace is not going to need to control anything with them, right? > The userspace API created by the patch is only for clients a.k.a. > "fieldbus devices". That's why I'm writing 'fieldbus_dev' all over the place. > > For simplicity, we could change that to just 'fieldbus'. But would this get > us in trouble when, at some point, we want to add a userspace API for > servers a.k.a. "fieldbus controllers" ? Ick, yeah, I guess so, but planning for future events is not something we do well at all. Are you sure you will need fieldbus controllers as a class? And as these are really devices, why not make them a "device" and a bus? What type of topology do you have on these busses? Are everything "flat" and connected directly to a PCI/USB/platform device? Or are there multiple devices attached to a single controller? It really feels like you want to use 'struct device' and a bus_type and not a class here to me... thanks, greg k-h
