About libinput and evdev

[Peter Hutterer]

On Fri, Aug 30, 2024 at 03:34:11PM +0800, starcold14 wrote:
> Hi，Xorg，
> I am a newbie of xorg. I am very confused about libinput,
> x86-input-libinput, xf86-input-synaptics, evdev:

> 1.x86-input-libinput uses libinput, does xf86-input-synaptics use libinput too?

xf86-input-synaptics does not use libinput

> 2.what is the relationship of x86-input-libinput and xf86-input-synaptics, are they two have conflicts ?

They're independent drivers, synaptics is just for touchpads, libinput
is for any (non-joystick) device. Only one driver can handle any one
device at a time but there are no conflicts otherwise.

> 3.dose libinput or xf86-input-synaptics or xorg use evdev directly?

all X input drivers on Linux use the evdev kernel API/protocol.
Exception are xf86-input-mouse and -keyboard which are used on other
platforms too. xf86-input-synaptics has non-evdev backends that are
used on other platforms but not Linux.

> 4.is there any graph or document discribe these things's relationship？

some "pretty" pictures are here:
https://wayland.freedesktop.org/libinput/doc/latest/what-is-libinput.html

Cheers,
  Peter