My previous question concern about LVDS integration with Linux and Yocto building, that is now working fine, I have working display but wakeup of display take about 6 seconds after hard boot.
Problem is related to time between hard reset and Linux kernel loading. Some driver functionality is needed to provide LVDS signal and DSI to LVDS bridge chip control to support signal conversion. It will take about 6 seconds before LVDS panel get initialized and during this time there is driven full white content for the panel even if the boot is halted into u-boot and this is not acceptable. I also tried to define splash screen but it was not succeeded.
I assume u-boot will use imx8mm-verdin.dtb because verdin-imx8mm.conf have this definition:
UBOOT_DTB_NAME = “imx8mm-verdin.dtb”, please confirm this.
Therefore I assume the source is imx8mm-verdin.dts. I cloned Toradex u-boot git (git clone -b toradex_imx_v2020.04_5.4.70_2.3.0 git://git.toradex.com/u-boot-toradex.git) I can find the file: \arch\arm\dts\imx8mm-verdin.dts.
I have patched this file to have support for LVDS panel timing and bridge chip, which basically mean remove of lt8912@48 node and add bridge@2c node instead just like it is working in Linux kernel side.
After Yocto build I can see from logs this patch is done without problems but I cannot find the result binary (imx8mm-verdin.dtb) anywhere from the device after image update. This led me situation I do not know if this binary is used at all by u-boot-toradex. I tried to verify this by halting u-boot run using console terminal and investigating file system after ‘ums 0 mmc 0’ is given for u-boot but all I can see is those several dtb files for the Linux kernel.
An other weird issue is the u-boot video and bridge drivers, if there is defined anything in DTB file there should also be driver for that hardware. I can not find any driver for LVDS bridge chip, but more weird I can not even find any driver for HDMI bridge chip. Does this mean Toradex u-boot does not support DSI bridge chips at all even those are products sold by Toradex ?
Therefore question is quite simple: Does Toradex reference Yocto BSP layers support display out in u-boot for Todadex Verdin LVDS adapter (Verdin DSI to LVDS Adapter - Toradex) ?
If not, is there instructions coming how to add it by customer ?