The HPGK touchpad that is found on the XO driver has historically
exhibitted eratic behaviour in various environments (very dry,
very humid, etc) that can be worked around via some delays. This
patch turns those delays into module parameters to make testing
simpler.
Signed-off-by: NPaul Fox <pgf@laptop.org>
Signed-off-by: NDeepak Saxena <dsaxena@laptop.org>
Acked-By: NAndres Salomon <dilinger@debian.org>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

The validate_byte check logic was backwards; it should return true for
an *invalid* packet.  Thanks to Jeremy Katz for spotting this one.
Signed-off-by: NAndres Salomon <dilinger@debian.org>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

This adds support for OLPC's touchpad.  It has lots of neat features,
none of which are enabled because the hardware is too buggy.  Instead,
we use it like a normal touchpad, but with a number of workarounds in
place to deal with the frequent hardware spasms.  Humidity changes,
sweat, tinfoil underwear, plugging in AC, drinks, evil felines.. All
tend to cause the touchpad to freak out.
Signed-off-by: NAndres Salomon <dilinger@debian.org>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>