How would one create a DPI LCD interface?

[PaddleStroke]

 

Hey guys,

I would like to interface a small RGB24 LCD on the H3 GPIO, similar to this on raspberry pi : 

https://www.raspberrypi.org/documentation/hardware/raspberrypi/dpi/README.md

http://blog.reasonablycorrect.com/raw-dpi-raspberry-pi

 

Is this feature already present on armbian device tree overlay? 

If no, how would one make it? Could someone help drawing the big picture so I know where to start?

 

After having a look at this section : https://docs.armbian.com/Hardware_Allwinner_overlays/

I understand that it would require writing a dt overlay (.dts file) to attribute the different functions to the GPIOs. But then how to write the functions?

I am quite familiar with the LCD datasheet and RGB pins function, the part that is still mistery for me is the driver writing: what file format? what programming language? where to drop the file?

 

Thanks!

Pierre

 

[MitchD]

This isn't a feature with the H2/H3 device trees because those CPUs don't have a DPI interface. You could try to use notro's fbtft library using the parallel option to drive your display, but I don't think he has support for RGB24. 

[zador.blood.stained]

All display interfaces require hardware support (well, except for SPI which is relatively low speed and is not a specialized display interface). H3 supports only HDMI and CVBS display outputs so it's impossible to connect a parallel RGB display without using a HDMI to RGB converter, or using a board based on a different SoC.