From mboxrd@z Thu Jan 1 00:00:00 1970 From: greg@kroah.com (Greg KH) Date: Wed, 15 Mar 2017 07:46:24 +0800 Subject: Merging device drivers to LK tree In-Reply-To: <30912.1489526052@turing-police.cc.vt.edu> References: <20170313214530.GB5539@kroah.com> <08d65c16-e9cc-11a3-a312-6d88cd2dd71b@gmail.com> <27519.1489523822@turing-police.cc.vt.edu> <871stzh8wn.fsf@miraculix.mork.no> <30912.1489526052@turing-police.cc.vt.edu> Message-ID: <20170314234624.GC19475@kroah.com> To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org On Tue, Mar 14, 2017 at 05:14:12PM -0400, valdis.kletnieks at vt.edu wrote: > On Tue, 14 Mar 2017 21:59:20 +0100, Bj?rn Mork said: > > > And another one: > > > > 5.) vendor independent class drivers > > > > > > IMHO perfect for the independent developer since there will be > > documentation available. The USB class specs are freely available for > > example. > > Hmm... /sys/class has a bunch of stuff already. /sys/class has nothing to do with a USB class specification :) > How many class drivers > are missing from there? And more importantly, class drivers for a hardware > class that's actually available (i.e. neither extinct or not shipping yet)? A USB "class" is a set of devices that follow a published specification. Like a USB HID device (keyboard/mouse/etc.) These are all published on the usb.org website. I think there still are a few class specs that are not yet implemented on Linux, usually because no one actually made any devices for them, or not enough that anyone really cares. A /sys/class/ entry is a kernel subsystem that describes a set of devices that interact with userspace in a defined way. Like an "input" class. That is how userspace interacts with _all_ keyboards, be they USB or PS/2 or i2c or whatever. Hope this helps, greg k-h