Touchscreen Input Device with RTEMS (evdev)

[Chris Johns]

On 2020-04-06 06:17, furkan bodur wrote:
> Hello everyone,
> I am trying to make an simple HMI system . I am using LittlevGL with BSD 
> framebuffer. Thanks to Vijay, I made a lot of progress, but I can't 
> figure it out how to use touchscreen or any input devices. I followed 
> LVGL docs and tried to work with evdev drivers but it doesn't work.
> 
> I used input.h and other necessary headers from rtems-libbsd and my app 
> successfully compiled but when I run it on the Beagle Black, I am 
> getting "unable open evdev interface:: No such file or directory" error 
> in serial screen.
> 
> I checked the files in Serial screen and noticed that there is no input 
> folder in the /dev directory, as in Linux systems. I think that's the 
> reason of the error, but I don't know where I made the mistake.
> 
> Any suggestions for me to use evdev properly?

I can see there is evdev code in libbsd so at least it is present. Are 
you able to confirm the evdev code is being built and linked into your 
application?

On FreeBSD I have ...

$ ls -las /dev/input
total 1
1 dr-xr-xr-x   2 root  wheel   512 Mar 21 08:22 .
1 dr-xr-xr-x  11 root  wheel   512 Mar 21 08:22 ..
0 crw-------   1 root  wheel   0xc Mar 21 08:22 event0
0 crw-------   1 root  wheel  0x29 Mar 21 08:22 event1
0 crw-------   1 root  wheel  0x8f Mar 22 13:42 event2
0 crw-------   1 root  wheel  0xa3 Mar 21 08:23 event4

but I am not sure how they were created.

Chris