[PATCH synaptics] Support the new Lenovo X1 Carbon 3rd trackpoint buttons

[Benjamin Tissoires]

On Wed, Jan 28, 2015 at 9:00 PM, Peter Hutterer
<peter.hutterer at who-t.net> wrote:
> This device has the trackpoint buttons wired up to the touchpad to send BTN_0,
> BTN_1 and BTN_2 for left, right, middle. This conflicts with previous
> touchpads that used those event codes for dedicated scroll buttons.
>
> Add an option HasTrackpointButtons that can be set via a xorg.conf.d
> snippets. This option is not intended as a user-set option, rather
> we expect distributions to ship some conglomerate of udev/hal rules with
> xorg.conf snippets that take effect.
>
> If the option is set, we look at the three affected buttons at the beginning
> of HandleState and send button events immediately for them. The HW state is
> reset to neutral and other processing continues. This saves us from having to
> synchronize these buttons with software buttons (also present on this device),
> tapping, etc.
>
> Since the buttons are physically different and (mentally) associated with the
> trackpoint device we also don't need to worry about having finger motion event
> correctly synced up with the button presses - it's acceptable to send the
> presses before the motion events.
>
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> ---

FWIW: Tested-by: Benjamin Tissoires <benjamin.tissoires at redhat.com>

Cheers,
Benjamin