evdev - Generic Linux input driver


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


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 and keyboards.

The evdev driver can serve as both a pointer and a keyboard input device, and may be used as both the core keyboard and the core pointer. Multiple input devices are supported by multiple instances of this driver, with one Load directive for evdev in the Module section of your xorg.conf for each input device that will use this driver.


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.


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.
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: on, until a middle mouse button event is registered. 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 "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. 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".
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 "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 "ReopenAttempts" "integer"
 Number of reopen attempts after a read error occurs on the device (e.g. after waking up from suspend). In between each attempt is a 100ms wait. Default: 10.
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".


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 run-time axis calibration. This feature is required for devices that need to scale to a different coordinate system than originally reported to the X server, such as touchscreens that require run-time 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 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.


Kristian Høgsberg.


Xorg(1), xorg.conf(5), Xserver(1), X(7), README.mouse.

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