.\" $NetBSD: pms.4,v 1.32.2.2 2020/10/08 16:47:12 martin Exp $
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.\" Copyright (c) 1993 Christopher G. Demetriou
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.\" <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
.\"
.Dd October 1, 2020
.Dt PMS 4
.Os
.Sh NAME
.Nm pms
.Nd PS/2 auxiliary port mouse driver
.Sh SYNOPSIS
.Cd pckbc* at isa?
.Cd pms* at pckbc?
.Cd wsmouse* at pms?
.Pp
.Cd options PMS_DISABLE_POWERHOOK
.Cd options PMS_SYNAPTICS_TOUCHPAD
.Cd options PMS_ELANTECH_TOUCHPAD
.Cd options PMS_ALPS_TOUCHPAD
.Sh DESCRIPTION
The
.Nm
driver provides an interface to PS/2 auxiliary port mice within the
.Xr wscons 4
framework.
Parent device in terms of the autoconfiguration framework is
.Xr pckbc 4 ,
the PC keyboard controller.
.Dq pms
is a generic driver which supports mice using common variants of the PS/2
protocol, including wheel mice of the
.Dq IntelliMouse
breed.
Wheel movements are mapped to a third (z-) axis.
The driver is
believed to work with both 3-button and 5-button mice with scroll wheels.
Mice which use other protocol extensions are not currently supported, but
might be if protocol documentation could be found.
Mouse related data are accessed by
.Xr wsmouse 4
devices.
.Pp
The
.Nm
driver has been updated to attempt to renegotiate mouse protocol after seeing
suspicious or defective mouse protocol packets, or unusual delays in the
middle of a packet; this should improve the chances that a mouse will recover
after being switched away or reset (for instance, by a console switch).
.Pp
The
.Va PMS_DISABLE_POWERHOOK
kernel option disables PS/2 reset on resume.
.Pp
In addition, the
.Nm
driver supports the
.Dq Synaptics ,
.Dq Elantech
and
.Dq ALPS
touchpads in native mode, enabled with the
.Va PMS_SYNAPTICS_TOUCHPAD ,
.Va PMS_ELANTECH_TOUCHPAD
and
.Va PMS_ALPS_TOUCHPAD
kernel options.
This allows the driver to take advantage of extra
features available on Synaptics, Elantech and ALPS Touchpads.
.Pp
The following
.Xr sysctl 8
variables control behavior of Synaptics touchpads:
.Bl -tag -width 8n
.It Dv hw.synaptics.up_down_emulation
If the touchpad reports the existence of extra ("Up/Down") buttons, this
value determines what kind of mouse events they should generate.
On certain clickpads, the Up/Down buttons may be physical buttons that
can be used instead of pressing the pad down, or used as additional
buttons.
.Bl -bullet
.It
If set to 0, Up/Down events generate button 4 and 5 clicks.
.It
If set to 1, Up/Down events generate middle button clicks.
.It
If set to 2, the Up and Down buttons are used for Z-axis emulation,
which more closely resembles how mouse wheels operate.
.It
If set to 3 (default), Up/Down events generate left/right clicks.
.El
.It Dv hw.synaptics.up_down_motion_delta
When the Up/Down buttons are used for Z-axis emulation, this value specifies
the emulated delta-Z value per click.
.It Dv hw.synaptics.gesture_move
Gestures will not be recognised if the finger moves by more than this
amount between taps.
.It Dv hw.synaptics.gesture_length
Gestures will not be recognised if the number of packets (at 80 packets
per second) between taps exceeds this value.
.It Dv hw.synaptics.edge_left
.It Dv hw.synaptics.edge_right
.It Dv hw.synaptics.edge_top
.It Dv hw.synaptics.edge_bottom
These values define a border around the touchpad which will be used for
edge motion emulation during a drag gesture.
If a drag gesture is in progress and the finger moves into this border,
the driver will behave as if the finger continues to move in the same
direction beyond the edge of the touchpad.
.It Dv hw.synaptics.edge_motion_delta
This specifies the pointer speed when edge motion is in effect.
.It Dv hw.synaptics.finger_high
The driver will ignore new finger events until the reported pressure exceeds
this value.
.It Dv hw.synaptics.finger_low
The driver will assume a finger remains on the touchpad until the
reported pressure drops below this value.
.It Dv hw.synaptics.two_fingers_emulation
More recent touchpads can report the presence of more than one finger
on the pad.
This value determines how such events are used.
.Bl -bullet
.It
If set to 0 (default), two-finger events are ignored.
.It
If set to 1, two-finger events generate a right button click.
.It
If set to 2, two-finger events generate a middle button click.
.El
.It Dv hw.synaptics.scale_x
.It Dv hw.synaptics.scale_y
.It Dv hw.synaptics.scale_z
Scale factor used to divide movement deltas derived from Synaptics
coordinates (0-6143) to yield more reasonable values (default 16 for x
and y, 1 for z).
.It Dv hw.synaptics.max_speed_x
.It Dv hw.synaptics.max_speed_y
.It Dv hw.synaptics.max_speed_z
Limits pointer rate of change (after scaling) per reported movement
event (default 32 for x and y, 2 for z).
.It Dv hw.synaptics.movement_threshold
Movements of less than this value (in Synaptics coordinates) are
ignored (default 4).
.It Dv hw.synaptics.button_boundary
Sets the top edge of the button emulation region on a clickpad.
Since a clickpad only reports left clicks this region is used to emulate
two or three buttons by detecting the finger location and reporting
either a button 2 or button 3 click iff the click occurs within
the region bounded by button_boundary and the bottom of the clickpad.
.It Dv hw.synaptics.button3_edge
This defines the left hand edge of the button 3 region.
If a click occurs in the region bounded by button_boundary, button3_edge
and the right hand edge of the click pad then the click will be reported
as a button3 event.
Button 3 emulation can be disabled by setting
button3_edge to the right hand edge of the clickpad.
.It Dv hw.synaptics.button2_edge
This defines the left hand edge of the button 2 region.
The button 2 region is bounded by button2_edge, button3_edge and
button_boundary.
If a click occurs in this region then it will be reported as a button2
event.
For completeness, the region between the left hand side of the clickpad,
button2_edge and button_boundary will be reported as a button1 event
as will any clicks that occur outside the button emulation region.
.It Dv hw.synaptics.finger_scroll-min
The minimum finger width at which the driver will start reporting
vertical movements as Z axis events.
Effectively, this emulates a mouse scroll wheel by the user using two
fingers together on the click pad.
The default value is 5, this value cannot be less than 5 due to the way
the clickpad reports finger width.
.It Dv hw.synaptics.finger_scroll-max
The maximum finger width at which the driver will report finger
movement as Z axis events.
The default value is 12 and cannot be greater than 14.
.It Dv hw.synaptics.finger_scroll-hysteresis
This defines the number of packets to continue with the Z axis emulation.
Due to the nature of the clickpad maintaining constant contact can be
difficult.
This hysteresis value prevents the driver flipping between two finger
scroll and normal mouse movement erratically.
Each time a valid finger scroll width is detected the packet count is
reset.
If this variable is set too high then mouse movements will be interpreted
as Z-axis events after the two finger scoll has finished.
If the variable is set too low then there will be mouse movements observed
during the two finger scroll.
.It Dv hw.synaptics.aux_mid_button_scroll
This causes Y-axis movement on the "passthrough device" (e.g. the TrackPoint
on ThinkPads) to result in scrolling events instead of Y-axis movement when
the middle button is held.
.El
.Pp
The following
.Xr sysctl 8
variables control behavior of Elantech touchpads:
.Bl -tag -width 8n
.It Dv hw.elantech.xy_precision_shift
.It Dv hw.elantech.z_precision_shift
Increased values improve the accuracy of X, Y, and Z-axis reporting
at the expense of slower mouse movement (default 2 for xy,
and 3 for z).
.El
.Pp
For Elantech touchpads, the Z-axis is emulated using two-finger
Y-axis reporting.
.Pp
The following
.Xr sysctl 8
variables control behavior of ALPS touchpads:
.Bl -tag -width 8n
.It Dv hw.alps.touchpad_xy_precision_shift
.It Dv hw.alps.tackstick_xy_precision_shift
Decreased values improve the accuracy of X and Y-axis reporting
at the expense of slower mouse movement (default 2 for touchpad
and 1 for TrackStick).
.El
.Sh SEE ALSO
.Xr pckbc 4 ,
.Xr ums 4 ,
.Xr wsmouse 4
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was originally written by
.An Christopher G. Demetriou .
The changes to merge the
.Dq IntelliMouse
protocol in, and reset the mouse in the event of protocol problems, were
contributed by
.An Peter Seebach .
Special thanks to Ray Trent, at Synaptics, who contributed valuable
insight into how to identify bogus mouse data.
The changes to add
.Dq Synaptics
pad support were by
.An Ales Krenek ,
.An Kentaro A. Kurahone ,
and
.An Steve C. Woodford .
The changes to add
.Dq Elantech
pad support were by
.An Jared D. McNeill .
.Sh BUGS
It is possible for the driver to mistakenly negotiate the non-scroll-wheel
protocol, after which it is unlikely to recover until the device is closed
and reopened.
.Pp
The
.Dq Elantech
pad code only supports trackpads with firmware version 2.48 or above.