Input: deactivate MT slots when inhibiting or suspending devices

When inhibiting or suspending a device we are sending release events for
all currently held keys and buttons, however we retain active MT slot
state, which causes issues with gesture recognition when we resume or
uninhibit.

Let's fix it by introducing, in addition to input_dev_release_keys(),
nput_mt_release_slots() that will deactivate all currently active slots.

Signed-off-by: Angela Czubak <acz@semihalf.com>
Link: https://lore.kernel.org/r/20220718151715.1052842-3-acz@semihalf.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: MT - avoid comma separated statements

Use semicolons and braces.

Signed-off-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/r/02cb394f8c305473c1a783a5ea8425de79fe0ec1.1598331149.git.joe@perches.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: mt - cleanup open-coded __set_bit()

Replace open-coded __set_bit() with the function.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/cf1dda3a372896cb01033ce084a7deb9620df7aa.1594599118.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Input: do not assign new tracking ID when changing tool type

We allow changing tool type (from MT_TOOL_FINGER to MT_TOOL_PALM) so we
should not be forcing new tracking ID for the slot.

Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: make input_report_slot_state() return boolean

Let's make input_report_slot_state() return boolean representing whether
the contact is active or not. This will allow writing code like:

if (input_mt_report_slot_state(input, obj->mt_tool,
obj->type != RMI_2D_OBJECT_NONE) {

input_event(sensor->input, EV_ABS, ABS_MT_POSITION_X, obj->x);
input_event(sensor->input, EV_ABS, ABS_MT_POSITION_Y, obj->y);
...
}

instead of:

input_mt_report_slot_state(input, obj->mt_tool,
obj->type != RMI_2D_OBJECT_NONE);
if (obj->type != RMI_2D_OBJECT_NONE) {
input_event(sensor->input, EV_ABS, ABS_MT_POSITION_X, obj->x);
input_event(sensor->input, EV_ABS, ABS_MT_POSITION_Y, obj->y);
...
}

Reviewed-by: Henrik Rydberg <rydberg@bitmath.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redaht.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

treewide: Use struct_size() for kmalloc()-family

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
int stuff;
void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:

// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
// sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@

- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)

Signed-off-by: Kees Cook <keescook@chromium.org>

Input: update input_mt_report_pointer_emulation to support hovering

For devices that are incapable of reporting per-contact distance and can
only report ABS_DISTANCE, just distance is not enough for upper layers of
OS to determine whether contact is leaving the area or if it is continuing
hovering, we need BTN_TOOL_FINGER for that:

Contact State
Inactive Hovering Active
(far away) (inside hover area) (touching surface)
BTN_TOUCH 0 0 1
BTN_TOOL_FINGER 0 1 1
ABS_DISTANCE N/A 1 0

Signed-off-by: KT Liao <kt.liao@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input - mt: Fix input_mt_get_slot_by_key

The case occurred recently with a touchscreen using twice a slot during a
single EV_SYN event:

E: 0.288415 0000 0000 0000 # ------------ SYN_REPORT (0) ----------
E: 0.296207 0003 002f 0000 # EV_ABS / ABS_MT_SLOT 0
E: 0.296207 0003 0039 -001 # EV_ABS / ABS_MT_TRACKING_ID -1
E: 0.296207 0003 002f 0001 # EV_ABS / ABS_MT_SLOT 1
E: 0.296207 0003 0035 0908 # EV_ABS / ABS_MT_POSITION_X 908
E: 0.296207 0003 0036 1062 # EV_ABS / ABS_MT_POSITION_Y 1062
E: 0.296207 0003 002f 0000 # EV_ABS / ABS_MT_SLOT 0
E: 0.296207 0003 0039 8787 # EV_ABS / ABS_MT_TRACKING_ID 8787
E: 0.296207 0003 0035 1566 # EV_ABS / ABS_MT_POSITION_X 1566
E: 0.296207 0003 0036 0861 # EV_ABS / ABS_MT_POSITION_Y 861
E: 0.296207 0003 0000 0908 # EV_ABS / ABS_X 908
E: 0.296207 0003 0001 1062 # EV_ABS / ABS_Y 1062
E: 0.296207 0000 0000 0000 # ------------ SYN_REPORT (0) ----------

This occurred because while having already slots 0 and 1 assigned, the
touchscreen sent:

0.293377 Tip Switch: 0 | Contact Id: 0 | X: 539 | Y: 1960 | Contact Count: 3
0.294783 Tip Switch: 1 | Contact Id: 1 | X: 908 | Y: 1062 | Contact Count: 0
0.296187 Tip Switch: 1 | Contact Id: 2 | X: 1566 | Y: 861 | Contact Count: 0

Slot 0 is released correclty, but when we look for Contact ID 2, the slot
0 is then picked up again because it is marked as inactive (trackingID < 0).

This is wrong, and we should not reuse a slot in the same frame.
The test should also check for input_mt_is_used().

In addition, we need to initialize mt->frame to an other value than 0.
With mt->frame being 0, all slots are tags as currently used, and so
input_mt_get_slot_by_key() would return -1 for all requests.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=88903

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Input: MT - make slot assignment work for overcovered solutions

The recent inclusion of a deassignment cost in the slot assignment
algorithm did not properly account for the corner cases where the
solutions are overcovered. This change makes sure the resulting
assignment is unique, allocating new slots when necessary.

Signed-off-by: Henrik Rydberg <rydberg@bitmath.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: MT - add support for balanced slot assignment

Some devices are not fast enough to differentiate between a fast-moving
contact and a new contact. This problem cannot be fully resolved because
information is truly missing, but it is possible to safe-guard against
obvious mistakes by restricting movement with a maximum displacement.

The new problem formulation for dmax > 0 cannot benefit from the speedup
for positive definite matrices, but since the convergence is faster, the
result is about the same. For a handful of contacts, the latency difference
is truly negligible.

Suggested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Henrik Rydberg <rydberg@bitmath.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: fix used slots detection breakage

Commit f8ec894945e7d205ce62be59e55e72c4304e4739 allowed external callers
use slot dropping logic, unfortunately it also broke external users of
input_mt_is_used() as we stopped incrementing frame count unless input
device was set up to automatically drop unused slots.

Fixes: f8ec894945e7d ("Input: MT - make slot cleanup callable outside
mt_sync_frame()")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=83081

Reported-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Tested-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: MT - make slot cleanup callable outside mt_sync_frame()

Some semi-mt drivers use the slots in a manual way, but may still
want to call parts of the frame synchronization logic. This patch
makes input_mt_drop_unused callable from those drivers.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Reviewed-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: MT - handle semi-mt devices in core

Most semi-mt drivers use the slots in a manual way, but really only
need to treat the finger count manually. With this patch, a semi-mt
driver may use the input-mt core for everything else.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: MT - do not apply filtering on emulated events

The pointer emulation events are derived from contact values that
have already been filtered, so send the emulated events as is.

Reported-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: mt: add input_mt_is_used

This patch extracts the test (slot->frame == mt->frame) so that it can
be used in third party drivers.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Input: MT - document new 'flags' argument of input_mt_init_slots()

Fixes new kernel-doc warning in input-mt.c:

Warning(drivers/input/input-mt.c:38): No description found for parameter
'flags'

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: fix sparse warning in multitouch code

This fixes the following sparse warning:
drivers/input/input-mt.c:193:18: warning: Using plain integer as NULL pointer

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: MT - Allow legacy pressure computation

Some drivers like to report ABS_PRESSURE in a special way.
Allow this when ABS_MT_PRESSURE is not defined.

Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

Input: MT - Get slot by key

Some devices use an internal key for tracking which cannot be directly
mapped to slots. This patch provides a key-to-slot mapping, which can
be used by drivers of such devices.

Reviewed-and-tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

Input: MT - Add in-kernel tracking

With the INPUT_MT_TRACK flag set, the function input_mt_assign_slots()
can be used to match a new set of contacts against the currently used
slots. The algorithm used is based on Lagrange relaxation, and performs
very well in practice; slower than mtdev for a few corner cases, but
faster in most commonly occuring cases.

Tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

Input: MT - Handle frame synchronization in core

Most MT drivers perform the same actions on frame synchronization.
Some actions, like dropping unseen contacts, are also unnecessarily
complex. Collect common frame synchronization tasks in a new function,
input_mt_sync_frame(). Depending on the flags set, it drops unseen
contacts and performs pointer emulation.

With init flags and frame synchronization in place, most MT drivers
can be simplified. First out are the bcm5974 and hid-multitouch
drivers, following this patch.

Reviewed-and-tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Tested-by: Ping Cheng <pingc@wacom.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

Input: MT - Add flags to input_mt_init_slots()

Preparing to move more repeated code into the mt core, add a flags
argument to the input_mt_slots_init() function.

Reviewed-and-tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Tested-by: Ping Cheng <pingc@wacom.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

Input: Improve the events-per-packet estimate

The events-per-packet estimate has so far been used by MT devices
only. This patch adjusts the packet buffer size to also accomodate the
KEY and MSC events. Keyboards normally send one or two keys at a
time. MT devices normally send a number of button keys along with the
MT information. The buffer size chosen here covers those cases, and
matches the default buffer size in evdev. Since the input estimate is
now preferred, remove the special input-mt estimate.

Reviewed-and-tested-by: Ping Cheng <pingc@wacom.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

Input: Break out MT data

Move all MT-related things to a separate place. This saves some
bytes for non-mt input devices, and prepares for new MT features.

Reviewed-and-tested-by: Benjamin Tissoires <benjamin.tissoires@enac.fr>
Tested-by: Ping Cheng <pingc@wacom.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

Input: MT - fix null pointer warning

Fixes the following sparse warning:
drivers/input/input-mt.c:138:40: warning: Using plain integer as NULL pointer

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

drivers/input: add export.h to symbol exporting files.

These files are not modules but are exporting symbols and/or
making use of THIS_MODULE macro.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

Input: add BTN_TOOL_QUINTTAP for reporting 5 fingers on touchpad

"4-finger scroll" is a gesture supported by some applications and
operating systems.

"Resting thumb" is when a clickpad user rests a finger (e.g., a
thumb), in a "click zone" (typically the bottom of the touchpad) in
anticipation of click+move=select gestures.

Thus, "4-finger scroll + resting thumb" is a 5-finger gesture.
To allow userspace to detect this gesture, we send BTN_TOOL_QUINTTAP.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Chase Douglas <chase.douglas@canonical.com>
Acked-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

input: mt: Move tracking and pointer emulation to input-mt

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: Ping Cheng <pingc@wacom.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

input: mt: Collect slots initialization code

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: Henrik Rydberg <rydberg@euromail.se>

input: mt: Break out slots handling

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: Henrik Rydberg <rydberg@euromail.se>