Input: hgpk - forced recalibration for the OLPC touchpad

The OLPC XO laptop incorporates a combination touchpad/tablet device
which unfortunately requires frequent recalibration.  The driver will
force this automatically when various suspicious behaviors are
observed, and the user can recalibrate manually (with a special
keyboard sequence). There's currently no way, however, for an external
program to cause recalibration. We can not use the reconnect
capability which is already available in /sys because full reset of
the touchpad takes 1.1 - 1.2 secons which is too long.

This patch creates a new node in /sys which, when written with '1',
will force a touchpad recalibration; no other writes (or reads)
of this node are supported.

Signed-off-by: Paul Fox <[email protected]>
Acked-by: Andres Salomon <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
1 file changed