libinput/doc/device-configuration-via-udev.dox

/**
@page udev_config Static device configuration via udev

libinput supports some static configuration through udev properties.
These propertiesare read when the device is initially added
to libinput's device list, i.e. before the @ref
LIBINPUT_EVENT_DEVICE_ADDED event is generated.

The following udev properties are supported:
<dl>
<dt>LIBINPUT_CALIBRATION_MATRIX</dt>
<dd>Sets the calibration matrix, see
libinput_device_config_calibration_get_default_matrix(). If unset,
defaults to the identity matrix.</dd>
<dt>LIBINPUT_DEVICE_GROUP</dt>
<dd>A string identifying the @ref libinput_device_group for this device. Two
devices with the same property value are grouped into the same device group,
the value itself is irrelevant otherwise.
</dd>
<dt>ID_SEAT</dt>
<dd>Assigns the physical seat for this device. See
libinput_seat_get_physical_name(). Defaults to "seat0".</dd>
<dt>WL_SEAT</dt>
<dd>Assigns the logical seat for this device. See
libinput_seat_get_logical_name()
context. Defaults to "default".</dd>
<dt>MOUSE_DPI</dt>
<dd>HW resolution and sampling frequency of a relative pointer device.
See @ref motion_normalization for details.
</dd>
<dt>MOUSE_WHEEL_CLICK_ANGLE</dt>
<dd>The angle in degrees for each click on a mouse wheel. See
libinput_pointer_get_axis_source() for details.
</dd>
</dl>

Below is an example udev rule to assign "seat1" to a device from vendor
0x012a with the model ID of 0x034b.
@code
ACTION=="add|change", KERNEL=="event[0-9]*", ENV{ID_VENDOR_ID}=="012a", \
ENV{ID_MODEL_ID}=="034b", ENV{ID_SEAT}="seat1"
@endcode

*/