This makes code safer and easier to read.
Signed-off-by: NPing Cheng <pingc@wacom.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

The drivers using the type B protocol all report tracking information
the same way. The contact id is semantically equivalent to
ABS_MT_SLOT, and the handling of ABS_MT_TRACKING_ID only complicates
the driver. The situation can be improved upon by providing a common
pointer emulation code, thereby removing the need for the tracking id
in the driver.  This patch moves all tracking event handling over to
the input core, simplifying both the existing drivers and the ones
currently in preparation.
Acked-by: NPing Cheng <pingc@wacom.com>
Acked-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NHenrik Rydberg <rydberg@euromail.se>

The MT slots devices all follow the same initialization pattern
of creating slots and hinting about buffer size. Let drivers call
an initialization function instead, and make sure it can be called
repeatedly without side effects.
Signed-off-by: NHenrik Rydberg <rydberg@euromail.se>

In preparation for common code to handle a larger set of MT slots
devices, move the slots handling over to a separate file.
Signed-off-by: NHenrik Rydberg <rydberg@euromail.se>

Some serial wacom devices support two-finger touch. Test for this during
init and parse the touch packets accordingly. Touch packets are
processed using Protocol B (MT Slots).

Note: there are several wacom versions that do touch but not two-finger
touch. These are not catered for here, touch events for these are simply
discarded.
Signed-off-by: NPeter Hutterer <peter.hutterer@who-t.net>
Acked-by: NHenrik Rydberg <rydberg@euromail.se>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Tablets that support touch input may report different sized packages,
depending on the touch sensor in the tablet. For now, discard the
packages until we report them as touch input proper.
Signed-off-by: NPeter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

The protocol used by the w8001 supports status fields for tip, side
switch and eraser as well as a RDY field for proximity.

The protocol has a double usage for the f2 bit in the packet. If set,
the data is either pen + side2 button or eraser. Assume eraser if the
device comes into proximity with the f2 bit set, otherwise trigger the
side2 button. If the device comes into proximity with the f2 bit and
that bit disappears afterwards, fake proximity out for the eraser and
proximity in for the pen.
Signed-off-by: NPeter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

There is no need for locking when we send query and start commands
to the touchscreen since there is no concurrency.
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

The Wacom W8001 sensor is a sensor device (uses electromagnetic
resonance) and it is interfaced via its serial microcontroller
to the host.
Signed-off-by: NJaya Kumar <jayakumar.lkml@gmail.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>