The driver is configured in a Linux system as follows:
Driver startup method
There are three popular methods used to launch user space processes, systemd, upstart and system V and we have implemented support for systemd and upstart. The installer tries to detect if systemd or upstart is active and invokes the driver using the appropriate method.
Interface
The driver posts touch data into the system via Xtest or uinput interfaces. The active system interface is described here.
The Xtest interface, which is an X11 extension, offers mouse button presses and mouse movement functionality, allowing for mouse emulation via touch.
Uinput offers a user mode bridge to the Linux input subsystem and allows for the posting of both single and multi touch data events. This interface requires uinput support being part of the Linux kernel and should be available for most modern distributions.
Both interfaces allow for a right click to be generated if required.
Default is uinput unless Xtest is specifically defined as the active system interface. For uinput, the driver creates either a single touch or multi-touch virtual device (default) and a separate virtual device to pass right click requests. Using the primary virtual touch device to post both touch data and right clicks caused issues in some distributions which were not seen when using separate devices.
Using the lsinput command you can view the UPDD virtual input device(s). Depending on the distribution in use LSinput may need to be installed. Run ‘sudo lsinput’ to list the devices:
Virtual device for posting single touch events
|
Virtual device for posting multi-touch events |
Virtual device for posting right click events |
/dev/input/eventnn
bustype : BUS_VIRTUAL
vendor : 0x1
product : 0x1
version : 1
name : "updd single touch"
bits ev : EV_SYN EV_KEY EV_ABS
|
/dev/input/eventnn
bustype : BUS_VIRTUAL
vendor : 0x1
product : 0x1
version : 1
name : "updd multi touch"
bits ev : EV_SYN EV_KEY EV_ABS
|
/dev/input/eventnn
bustype : BUS_VIRTUAL
vendor : 0x1
product : 0x1
version : 1
name : "updd right mouse button"
bits ev : EV_SYN EV_KEY EV_ABS
|
Processes
The ps (process status) command is used to provide information about the currently running processes, including their process identification numbers (PIDs).
Running this command on a default driver installation results is the following listing:
Start / stopping the driver
Should you need to stop / start the driver, say to activate a setting update that is only activated at driver load, you can of course reboot the system or run the commands:
sudo systemctl stop updd
sudo systemctl start updd