we have successfully connected a S231AJ1 Innolux Display (Datasheet: link). Its resolution is officially 1920 * 256, but indeed, it is just 1920 * 158 because of a black stripe. The problem is the following:
The text on the screen is rotated and mirror-inverted. Hence, we would like to have the display rotated and mirrored, so that we have the console output (text is not mirrored any more) over the whole size of 60cm (not only 5cm). Within the datasheet, you can find on page … that this is normal for the display.
We think, ideally, we change this in the framebuffer. Maybe, we can change it in the uenv? In recherches, we detected the variable called IPU_ROTATE_90_RIGHT_VFLIP. We think, this is the right option, but we do not know how to use set it correctly and where…
Our perfect solution was to set it just for one lvds channel.
AFAIK there is no way that the current IPU driver can display the framebuffer rotated.
The enumeration you point to is AFAIK used when with camera inputs or camera inputs copied into the framebuffer to be displayed. (BTW. you look at really old kernel sources)
This NXP community thread is about patching the kernel for basic rotation support. It may or may not work for your case.
we build a YOCTO Linux Image without X11. We just use eglfs for our Aplikations. Thats why we don’t have xrandr. Many of our Applikations use QT5. There it would be possible to rotate it. But we would also like to see the console output. That’s why we would like to change it direkt in the creation of the Framebuffer.
The IPU has the ability to rotate the Framebuffer (See Here: GITHUB). The Only Problem is I’m not shure were in the Kernel I must set this parameter.
Please correct me, If I’m wrong. I think this is the LVDS framebuffer driver. Here is an option rotate. That’s why I think there is a way. I don’t have found any Information in the Kernel or in the internet how to set rotate. I have tried to echo values and test many other things but nothing happens.
In the research I found that NXP comminty thread. From there I have the Idea to patch the Kernel. Why do you think this is not possible?