Ubuntu Manpage: evdev - Generic Linux input driver

Provided by: xserver-xorg-input-evdev_2.10.6-2build1_amd64

NAME

       evdev - Generic Linux input driver

SYNOPSIS

       Section "InputDevice"
         Identifier "devname"
         Driver "evdev"
         Option "Device"   "devpath"
         Option "Emulate3Buttons"     "True"
         Option "Emulate3Timeout"     "50"
         Option "GrabDevice"     "False"
         ...
       EndSection

DESCRIPTION

       evdev is an Xorg input driver for Linux´s generic event devices.  It therefore supports all input devices
       that  the  kernel  knows  about,  including most mice, keyboards, tablets and touchscreens.  evdev is the
       default driver on the major Linux distributions.

       The evdev driver can serve as both a pointer and a keyboard input  device.  Multiple  input  devices  are
       supported  by  multiple instances of this driver, with one InputDevice section of your xorg.conf for each
       input device that will use this driver.

       It is recommended  that  evdev  devices  are  configured  through  the  InputClass  directive  (refer  to
       xorg.conf(5))  instead of manual per-device configuration. Devices configured in the xorg.conf(5) are not
       hot-plug capable.

SUPPORTED HARDWARE

       In general, any input device that the kernel has a driver for can be accessed through the  evdev  driver.
       See the Linux kernel documentation for a complete list.

CONFIGURATION DETAILS

Please refer to xorg.conf(5) for general configuration details and for options that can be used with all
input drivers. This section only covers configuration details specific to this driver.

The following driver Options are supported:

Option "ButtonMapping" "string"
Sets the button mapping for this device. The mapping is a space-separated list of button mappings
that correspond in order to the physical buttons on the device (i.e. the first number is the
mapping for button 1, etc.). The default mapping is "1 2 3 ... 32". A mapping of 0 deactivates the
button. Multiple buttons can have the same mapping. For example, a left-handed mouse with
deactivated scroll-wheel would use a mapping of "3 2 1 0 0". Invalid mappings are ignored and the
default mapping is used. Buttons not specified in the user's mapping use the default mapping.

Option "Device" "string"
Specifies the device through which the device can be accessed. This will generally be of the form
"/dev/input/eventX", where X is some integer. The mapping from device node to hardware is system-
dependent. Property: "Device Node" (read-only).

Option "DragLockButtons" "L1 B2 L3 B4"
Sets "drag lock buttons" that simulate holding a button down, so that low dexterity people do not
have to hold a button down at the same time they move a mouse cursor. Button numbers occur in
pairs, with the lock button number occurring first, followed by the button number that is the
target of the lock button. Property: "Evdev Drag Lock Buttons".

Option "DragLockButtons" "M1"
Sets a "master drag lock button" that acts as a "Meta Key" indicating that the next button pressed
is to be "drag locked". Property: "Evdev Drag Lock Buttons".

Option "Emulate3Buttons" "boolean"
Enable/disable the emulation of the third (middle) mouse button for mice which only have two
physical buttons. The third button is emulated by pressing both buttons simultaneously. Default:
off. Property: "Evdev Middle Button Emulation".

Option "Emulate3Timeout" "integer"
Sets the timeout (in milliseconds) that the driver waits before deciding if two buttons where
pressed "simultaneously" when 3 button emulation is enabled. Default: 50. Property: "Evdev Middle
Button Timeout".

Option "Emulate3Button" "integer"
Specifies the physical button number to be emitted if middle button emulation is triggered.
Default: 2. Property: "Evdev Middle Button Button".

Option "EmulateWheel" "boolean"
Enable/disable "wheel" emulation. Wheel emulation means emulating button press/release events
when the mouse is moved while a specific real button is pressed. Wheel button events (typically
buttons 4 and 5) are usually used for scrolling. Wheel emulation is useful for getting wheel-like
behaviour with trackballs. It can also be useful for mice with 4 or more buttons but no wheel.
See the description of the EmulateWheelButton, EmulateWheelInertia, EmulateWheelTimeout,
XAxisMapping, and YAxisMapping options. Default: off. Property "Evdev Wheel Emulation".

Option "EmulateWheelButton" "integer"
Specifies which button must be held down to enable wheel emulation mode. While this button is
down, X and/or Y pointer movement will generate button press/release events as specified for the
XAxisMapping and YAxisMapping settings. If the button is 0 and EmulateWheel is on, any motion of
the device is converted into wheel events. Default: 4. Property: "Evdev Wheel Emulation Button".

Option "EmulateWheelInertia" "integer"
Specifies how far (in pixels) the pointer must move to generate button press/release events in
wheel emulation mode. Default: 10. Property: "Evdev Wheel Emulation Inertia".

This value must be set for any device does not resemble a standard mouse. Specifically, on
absolute devices such as tablets the value should be set to a reasonable fraction of the expected
movement to avoid excess scroll events.

WARNING: the name "inertia" is a misnomer. This option defines the distance required to generate
one scroll event similar to the VertScrollDelta and HorizScrollDelta options. It does not enable
inertia in the physical sense, scrolling stops immediately once the movement has stopped.

Option "EmulateWheelTimeout" "integer"
Specifies the time in milliseconds the EmulateWheelButton must be pressed before wheel emulation
is started. If the EmulateWheelButton is released before this timeout, the original button
press/release event is sent. Default: 200. Property: "Evdev Wheel Emulation Timeout".

Option "EmulateThirdButton" "boolean"
Enable third button emulation. Third button emulation emits a right button event (by default) by
pressing and holding the first button. The first button must be held down for the configured
timeout and must not move more than the configured threshold for the emulation to activate.
Otherwise, the first button event is posted as normal. Default: off. Property: "Evdev Third
Button Emulation".

Option "EmulateThirdButtonTimeout" "integer"
Specifies the timeout in milliseconds between the initial button press and the generation of the
emulated button event. Default: 1000. Property: "Evdev Third Button Emulation Timeout".

Option "EmulateThirdButtonButton" "integer"
Specifies the physical button number to be emitted if third button emulation is triggered.
Default: 3. Property: "Evdev Third Button Button".

Option "EmulateThirdButtonMoveThreshold" "integer"
Specifies the maximum move fuzz in device coordinates for third button emulation. If the device
moves by more than this threshold before the third button emulation is triggered, the emulation is
cancelled and a first button event is generated as normal. Default: 20. Property: "Evdev Third
Button Emulation Threshold".

Option "GrabDevice" "boolean"
Force a grab on the event device. Doing so will ensure that no other driver can initialise the
same device and it will also stop the device from sending events to /dev/kbd or /dev/input/mice.
Events from this device will not be sent to virtual devices (e.g. rfkill or the Macintosh mouse
button emulation). Default: disabled.

Option "InvertX" "Bool"

Option "InvertY" "Bool"
Invert the given axis. Default: off. Property: "Evdev Axis Inversion".

Option "IgnoreRelativeAxes" "Bool"

Option "IgnoreAbsoluteAxes" "Bool"
Ignore the specified type of axis. Default: unset. The X server cannot deal with devices that have
both relative and absolute axes. Evdev tries to guess wich axes to ignore given the device type
and disables absolute axes for mice and relative axes for tablets, touchscreens and touchpad.
These options allow to forcibly disable an axis type. Mouse wheel axes are exempt and will work
even if relative axes are ignored. No property, this configuration must be set in the
configuration.
If either option is set to False, the driver will not ignore the specified axes regardless of the
presence of other axes. This may trigger buggy behavior and events from this axis are always
forwarded. Users are discouraged from setting this option.

Option "Calibration" "min-x max-x min-y max-y"
Calibrates the X and Y axes for devices that need to scale to a different coordinate system than
reported to the X server. This feature is required for devices that need to scale to a different
coordinate system than originally reported by the kernel (e.g. touchscreens). The scaling to the
custom coordinate system is done in-driver and the X server is unaware of the transformation.
Property: "Evdev Axis Calibration".

Option "Mode" "Relative"|"Absolute"
Sets the mode of the device if device has absolute axes. The default value for touchpads is
relative, for other absolute. This option has no effect on devices without absolute axes.

Option "SwapAxes" "Bool"
Swap x/y axes. Default: off. Property: "Evdev Axes Swap".

Option "XAxisMapping" "N1 N2"
Specifies which buttons are mapped to motion in the X direction in wheel emulation mode. Button
number N1 is mapped to the negative X axis motion and button number N2 is mapped to the positive X
axis motion. Default: no mapping. Property: "Evdev Wheel Emulation Axes".

Option "YAxisMapping" "N1 N2"
Specifies which buttons are mapped to motion in the Y direction in wheel emulation mode. Button
number N1 is mapped to the negative Y axis motion and button number N2 is mapped to the positive Y
axis motion. Default: "4 5". Property: "Evdev Wheel Emulation Axes".

Option "TypeName" "type""
Specify the X Input 1.x type (see XListInputDevices(3)). There is rarely a need to use this
option, evdev will guess the device type based on the device's capabilities. This option is
provided for devices that need quirks.

Option "VertScrollDelta" "integer"
The amount of motion considered one unit of scrolling vertically. Default: "1". Property: "Evdev
Scrolling Distance".

Option "HorizScrollDelta" "integer"
The amount of motion considered one unit of scrolling horizontally. Default: "1". Property:
"Evdev Scrolling Distance".

Option "DialDelta" "integer"
The amount of motion considered one unit of turning the dial. Default: "1". Property: "Evdev
Scrolling Distance".

Option "Resolution" "integer"
Sets the resolution of the device in dots per inch. The resolution is used to scale relative
motion events from mouse devices to 1000 DPI resolution. This can be used to make high resolution
mice less sensitive without turning off acceleration. If set to 0 no scaling will be performed.
Default: "0".

SUPPORTED PROPERTIES

       The following properties are provided by the evdev driver.

       Evdev Axis Calibration
              4  32-bit  values,  order  min-x,  max-x,  min-y,  max-y  or  0  values  to disable in-driver axis
              calibration.

       Evdev Axis Inversion
              2 boolean values (8 bit, 0 or 1), order X, Y. 1 inverts the axis.

       Evdev Axes Swap
              1 boolean value (8 bit, 0 or 1). 1 swaps x/y axes.

       Evdev Drag Lock Buttons
              8-bit. Either 1 value or pairs of values. Value range 0-32, 0 disables a value.

       Evdev Middle Button Emulation
              1 boolean value (8 bit, 0 or 1).

       Evdev Middle Button Timeout
              1 16-bit positive value.

       Evdev Middle Button Button
              1 8-bit value, allowed range 0-32, 0 disables the button.

       Evdev Wheel Emulation
              1 boolean value (8 bit, 0 or 1).

       Evdev Wheel Emulation Axes
              4 8-bit values, order X up, X down, Y up, Y down. 0 disables a value.

       Evdev Wheel Emulation Button
              1 8-bit value, allowed range 0-32, 0 disables the button.

       Evdev Wheel Emulation Inertia
              1 16-bit positive value.

       Evdev Wheel Emulation Timeout
              1 16-bit positive value.

       Evdev Scrolling Distance
              3 32-bit values: vertical, horizontal and dial.

AUTHORS

       Kristian Høgsberg, Peter Hutterer