TI AM62X supports splash screen in upstream u-boot

EARLY SPLASH SCREEN FOR TI's AM62X

Almost every product that has a screen for user interface expects a very early (< 1 second) display of "product logo" also known as early splash screen when turned ON.

The early splash of logo on screen requires display drivers to be integrated in boot loader, for Linux OS we use u-boot as standard boot loader and even before u-boot it's the SPL that comes up first and initializes the DDR and loads the Linux and file system images. The driver should be enabled in both u-boot and SPL to get an early experience of Splash Screen.

My team at Texas Instruments has introduced the support for AM62x display in u-boot and has successfully up-streamed it.  

• Sources : on master branch of u-boot https://source.denx.de/u-boot/u-boot 
• Tags : tags-2023.04 
• TIDSS driver folder : drivers/video/tidss.

This feature will be available in our next release of TI Linux SDK, but our partners and customers can get this feature ported now by upgrading to u-boot version 2023.04 or by back porting these patches to the version of u-boot they are using currently.

The patch series can be found here

Apart from porting the driver, there are few additional steps that need to be implemented to get the feature enabled for your platform.

1. add support for TIDSS in dts file: arm: dts: k3-am62-main: Add device tree node for TIDSS
2. enable pin controls :  arm: dts: k3-am625-sk: Add pin control for TIDSS and add panel device tree node 
3. enable pre-ram flags : arch: arm: dts: k3-am625-sk: add bootph-pre-ram flags 

An example of these dts changes can be found here

NOTE: The video file in the link above demonstrates the splash screen with in 1 sec of turning ON of the board, the first logo is from SPL and then there is a blank screen and the logo appears for the second time and this time it's from u-boot. It's up to our customers to utilize these features as applicable to final product.

The patches for SPL are still under review and not available upstream yet, the patch series can be pulled from the links given below:

• Patch series to introduce splash framework in SPL 
• Patch series to enable SPL splash for AM62x 

Credits:  Nikhil Jain - for the content and upstreaming this feature in u-boot opensource projects.