I am trying to find out whether it is possible to change the display on Nexus 4(WXGA) to 400x400 for designing application for wearables of any similar resolution.
Till now I have tried changing the video panel coordinates from 768x1280 to 400x400 in display driver file: mipi_lgit_video_wxga_pt.c. But only the display is changing to 400x400. Touchscreen is still mapped to the original resolution.
I am starting to doubt that whether this is possible or not with the display driver of Nexus 4.
Any help will be really appreciated.
I think this is not possible as MIPI displays use microcontroller with data lanes that work at a very specific frequency and data BW. As from the interface you don't have control on how the data you send is being drawn to LCD.
You can however 'fool' the driver by sending black pixels as filler, but you probably need to patch the display HAL and framework which is not easy and I'm not sure it will give you trustworthy testing tool
As an alternative, you can try buying some R-PI or similar and using HDMI connection to get the resolution you want.