DTS file modification BPI-R64, LCD TFT Setting up

Greetings to everyone,

Firts I want to apologize if this question is something newbie, I' m really new in Linux.
My doubt is:

I'm trying to use a 2.8 SPI LCD TFT 240X320 V1.2 with Banana PI - R64 (BPI-R64) I was searching and searching about how to do, in this page (https://forum.banana-pi.org/t/banana-pi-bpi-r64-spi-touch-panel-test-with-openwrt/10009/2) says I have to modify dts file and add modules to kernel, I used https://git.openwrt.org/openwrt/openwrt.git repo to build a new system following this steps https://openwrt.org/docs/guide-developer/toolchain/use-buildsystem#defconfig, now I can create a new image and sysupgrade with new packages, but I was searching how to modify DTS file and I found in the forum that dts file is located in : /target/linux/mediatek/files-x.xx/arch/ but I can't find arch directory.

Could someone say me how to modify dts file? or if I'm wrong about how to set up LCD please someone can explain to me how to use TFT LCD in BPI-R64 with Openwrt? I'm really grateful if someone can explain to me step by step.
Thanks a lot.

Thanks for your reply.
Right there is a folder there but it doesn't have dts for BananaPi R64, I don't know if those dts works to Banana Pi R64, could you explain how to do?.
Thanks a lot.

Thanks for your reply,
Sorry , I'm not understand yet, means that could I create a dts file using the name mt7622-bananapi-bpi-r64 and saved in the directory target/linux/mediatek/dts, and when a do the make to compile the new image this image Wil have dts configuration ? Sorry I'm really new in this, I apologize.
Thanks for all.

DEVICE_DTS := does indeed specify the DTS file name.

It's a bit weird since @slh 's link to the git tree doesn't show the R64 DTS while that Makefile uses it. Something's amiss there. Same in the official git repo.

Edit: looks like the DTS comes with the kernel tarball, so you should extract that and check the DTS there. There are a few patches in the OpenWrt tree that modify that DTS.

Thanks for your reply,

So means that should I install the generated build image in the system BPI-R64 and then modify DTS?
Could you specify what means "patches in the OpenWrt tree that modify that DTS."
Thanks a lot.

Check the tree:


Bottom two modify the DTS. This has useful info as well: