Re: 'Phys:' field for keyboards (and other input devices)

[Vojtech P. <vo...@su...>]

On Fri, Sep 27, 2002 at 01:22:39PM -0600, Brad Midgley wrote:
> > Right now i am putting together a system which (among other) uses
> > a userspace mechanism to determine the vt which it should bind
> > keyboards to. for conveniance i am useing the hotplug interface
> > and consider extending hotplug to return vt numbers. 
> 
> i wrote an app a while ago that put up "press 0" and "press 1" etc on each head and used the result to map keyboards. (it was in conjunction with a failed attempt to patch the kernel for multihead)
> 
> i looked a bit and couldn't find the source, but you get the idea.
> 
> one problem is that two usb keyboards would come up in a random order and you'd have to do this at every boot and every time keyboards were plugged/unplugged. not fun. do usb keyboards have a serial number? (dreaming i'm sure)

No, but they have the "PHYS" value readable from either /dev/input/event
devices using an ioctl, or from /proc/bus/input/devices. This reflects
which connector on the USB Hub they're connected to.

-- 
Vojtech Pavlik
SuSE Labs