sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

evdev: Add parentheses around '-' expression in operand of '&'.

This fixes a -Wparentheses error with GCC 9.

Reviewed by: wulf
Differential Revision: https://reviews.freebsd.org/D31947

evdev: Do not export multitouch functions which are unused outside evdev

evdev: Add support for automatic MT protocol type A to type B conversion.

MFC after: 2 weeks

evdev: Add implicit mode for touch tracking.

In implicit mode assignment of slot number and tracking id is performed
automatically on each synchronization requested by device driver.

This is done with creation of intermediate buffer for multitouch events.
This buffer holds untracked events until synchronization is requested by
device driver. It is needed as touch assigment requires
knowledges of all touch positions pushed in current and previous reports.

MFC after: 2 weeks

evdev: Import support for touch-tracking.

Touch tracking is a process of assignment of unique trackingID to each
initiated contact on the surface. Keeping the trackingIDs persistent
across multitouch reports requires solving of so called Euclidian
Bipartite Matching problem.

This commit imports EBM-solver implementation based on Dinitz-Kronrod
algorithm to find minimum cost matching between contacts listed in two
consecutive reports.

Obtained from: OpenBSD
MFC after: 2 weeks

evdev: Make MT tracking IDs monotonically increasing sequence.

MFC after: 2 weeks

evdev: Give short aliases to items of evdev_mt_slot array

with using of unioned anonymous structure.

Access to the same data by using different members of union generally
works despite it is not supported by C specs.

Also add helper function to report entire slot state.

MFC after: 2 weeks

evdev: Normalize width and pressure of single touch compat events

to match Synaptics touchpad reporting range.

MFC after: 2 weeks

evdev: force no fuzz for autogenerated single touch compat events.

As fuzz has already been applied on multitouch event processing.
This allows to remove existing workaround for double fuzz procesing.

MFC after: 2 weeks

evdev: Send first active rather than 0-th slot state as ST report

MFC after: 2 weeks

evdev: Use bitsets to track active touches and slots changed in current report

Obtained from: OpenBSD

MFC after: 2 weeks

evdev: Multitouch code style changes.

1. Move touch count reporting helpers to utils. They are not multitouch.
2. Use evdev_mt prefix for private multitouch support routines.
3. Use int instead of int32_t where fixed size is not required.
4. Export some internal functions.

This change should be no-op.

MFC after: 2 weeks

evdev: Remove useless "initial value" parameter from evdev_support_abs()

It can not be used for setting of state of multitouch events.
If necessary, use evdev_push_event() instead of it.

Change my email address to wulf@FreeBSD.org in copyright headers.

Approved by: gonzo (mentor)
MFC after: 2 weeks

evdev: Macroize common locking sequences

Reviewed by: gonzo
Approved by: gonzo (mentor)
MFC after: 2 weeks

evdev: style(9), sort headers alphabetically

Pointed out by: bde
Reviewed by: gonzo
Approved by: gonzo (mentor)
MFC after: 2 weeks

Implement EVDEV_FLAG_MT_AUTOREL flag (autorelease touchpoints)

Automaticaly release (send ABS_MT_TRACKING_ID = -1) MT-slots
that has not been listed in current MT protocol type B report.

Slot is counted as listed if corresponding ABS_MT_SLOT event
has been sent regardless of other MT events.

Events are sent on SYN_REPORT event.

Submitted by: Vladimir Kondratiev <wulf@cicgroup.ru>

Allow using of driver's mutex instead internal one for evdev locking.

Add new API call: evdev_register_mtx which takes lock argument that
should be used instead of internal one for evdev locking. Useful for
cases if evdev_push_event() is always called with driver's lock taken
and reduces amount of lock aquisitions. This allows to avoid LOR
between ev_open/ev_close invocations and evdev_push_event() Such LOR
can happen when ev_open/ev_close methods acquire driver lock and
evdev_push_event() is called with this lock taken.

Submitted by: Vladimir Kondratiev <wulf@cicgroup.ru>

Add evdev protocol implementation

evdev is a generic input event interface compatible with Linux
evdev API at ioctl level. It allows using unmodified (apart from
header name) input evdev drivers in Xorg, Wayland, Qt.

This commit has only generic kernel API. evdev support for individual
hardware drivers like ukbd, ums, atkbd, etc. will be committed later.

Project was started by Jakub Klama as part of GSoC 2014. Jakub's
evdev implementation was later used as a base, updated and finished
by Vladimir Kondratiev.

Submitted by: Vladimir Kondratiev <wulf@cicgroup.ru>
Reviewed by: adrian, hans
Differential Revision: https://reviews.freebsd.org/D6998