The fact that we were calling focaltech_init() even when Focaltech support
is disabled was confusing. Rearrange the code so that if support is
disabled we continue to fall through the rest of protocol probing code
until we get to full reset that Focaltech devices need to work properly.

Also, replace focaltech_init() with a stub now that it is only called when
protocol is enabled.
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NPali Rohár <pali.rohar@gmail.com>
Tested-by: NMarcin Sochacki <msochacki+kernel@gmail.com>
Tested-by: NTill <till2.schaefer@uni-dortmund.de>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Focaltech touchpads report finger width in packet[5] of absolute packet.
Range for width in raw format is 0x10 - 0x70. Second half-byte is always 0.
0xff is reported, when a large contact area is detected.
This can be handled in userspace.
Signed-off-by: NDmitry Tunin <hanipouspilot@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Apparently, the threshold for large contact area seems to be rather low on
some devices, causing the touchpad to frequently freeze during normal
usage. Because we do now know how we are supposed to use the value in
question, this commit just drops the related code completely.
Signed-off-by: NMathias Gottschlag <mgottschlag@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

These PS/2 commands make some touchpads stop responding, so this commit
adds some dummy functions to replace the generic implementation. Because
scale changes were not encapsulated in a method of struct psmouse yet, this
commit adds a method set_scale to psmouse.
Signed-off-by: NMathias Gottschlag <mgottschlag@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

We don't know whether x_max or y_max really hold the maximum possible
coordinates, and we don't know for sure whether we correctly interpret the
coordinates sent by the touchpad, so we clamp the reported values to
prevent confusion in userspace code.
Signed-off-by: NMathias Gottschlag <mgottschlag@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

The size has in most cases already been fetched from the touchpad, the
hardcoded values should have been removed.
Signed-off-by: NMathias Gottschlag <mgottschlag@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Instead of having various protocols provide <protocol>_supported()
functions, let's use IS_ENABLED() macro that works well in "if" statements.
Acked-by: NHans de Goede <hdegoede@redhat.com>
Reviewed-by: NBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

Most of the protocol for these touchpads has been reverse engineered. This
commit adds a basic multitouch-capable driver.

A lot of the protocol is still unknown. Especially, we don't know how to
identify the device yet apart from the PNP ID.

The previous workaround for these devices has been left in place in case
the driver is not compiled into the kernel or in case some other device
with the same PNP ID is not recognized by the driver yet still has the same
problems with the device probing code.
Signed-off-by: NMathias Gottschlag <mgottschlag@gmail.com>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

The Asus X450 and X550 laptops use a PS/2 touchpad from a new
manufacturer called FocalTech:

https://bugzilla.kernel.org/show_bug.cgi?id=77391
https://bugzilla.redhat.com/show_bug.cgi?id=1110011

The protocol for these devices is not known at this time, but even
without knowing the protocol they need some special handling. They get
upset by some of our other PS/2 device probing, and once upset generate
random mouse events making things unusable even with an external mouse.

This patch adds detection of these devices based on their pnp ids, and
when they are detected, treats them as a bare ps/2 mouse. Doing things
this way they at least work in their ps/2 mouse emulation mode.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>