18bit LVDS display

Technical Support
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1

Hi,

We are using a Verdin iMX8MP SoM with a 6.5" LCD panel that supports an 18-bit parallel RGB interface.
We attempted to modify the existing 24-bit VESA LVDS overlay to support an 18-bit JEIDA-style interface, but the display only shows a white screen.

Could you please provide a correct device tree (DTS/overlay) example for an 18-bit LVDS panel configuration?

Thank you.

2

Hi, I’m the Toradex AI Assistant.

I might make mistakes or occasionally get you wrong. Our support team will step in if needed.

I’d be glad to help! Could you let me know which OS and version you are using? Also, please run the tdx-info command to get detailed information about your setup - you can find more details about this command at tdx-info documentation.

This information will help me provide the most accurate device tree overlay configuration for your 18-bit LVDS panel on the Verdin iMX8MP.

Best regards, Toradex AI Assistant.

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3

Thank you for the response.

Detailed information are listed below:

root@verdin-imx8mp-15460338:~# tdx-info

Software summary

Bootloader: U-Boot

Kernel version: 6.6.84-7.2.0-devel #1 SMP PREEMPT Mon Mar 31 08:47:48 UTC 2025
Kernel command line: root=PARTUUID=076c4a2a-02 ro rootwait console=tty1 console=ttymxc2,115200 clk-imx8mp.mcore_booted=1
Distro name: NAME=“TDX Wayland with XWayland”
Distro version: VERSION_ID=7.2.0-devel-20250409065055-build.0
Distro variant: -
Hostname: verdin-imx8mp-15460338

Hardware info

HW model: Toradex Verdin iMX8M Plus on Verdin Development Board

Toradex version: 0063 V1.1B
Serial number: 15460338
Processor arch: aarch64

4

Thank you for providing the detailed system information! Based on your setup (Verdin iMX8MP V1.1B running Torizon OS 7.2.0-devel), I can help you configure an 18-bit LVDS panel with JEIDA format.

Understanding LVDS Interface Options

The Verdin iMX8MP supports both 18-bit and 24-bit LVDS interfaces with different color mapping standards(1). For 18-bit displays, you need to use the JEIDA format (Intel 24.0 LVDS data format), which is backward compatible and allows connecting 18-bit displays to 24-bit interfaces(1).

Available Pre-built Overlays

For Torizon OS 7.x on Verdin iMX8MP, the following LVDS overlays are available(2):

  • verdin-imx8mp_panel-cap-touch-10inch-lvds_overlay.dtbo - LVDS native, Capacitive Touch Display 10.1" LVDS
  • verdin-imx8mp_dsi-to-lvds_panel-cap-touch-10inch-lvds_overlay.dtbo - DSI to LVDS, Capacitive Touch Display 10.1" LVDS

Device Tree Configuration for 18-bit JEIDA LVDS

Based on the datasheet information, here’s how to configure your custom 18-bit LVDS overlay(1):

Key Configuration Points:

  1. Data Mapping: Set fsl,data-mapping = "jeida"
  2. Data Width: Set fsl,data-width = <18>
  3. Panel Timing: Configure according to your 6.5" panel specifications

LVDS Signal Configuration

The 18-bit JEIDA format uses the following signal mapping(1):

  • LVDS1_A_TX0+/-: Contains R5-R0, G2 signals
  • LVDS1_A_TX1+/-: Contains G5-G0, B3 signals
  • LVDS1_A_TX2+/-: Contains B5-B0, DE, VSYNC, HSYNC signals
  • LVDS1_A_TX3+/-: No output (Hi-Z) for 18-bit mode

Applying the Overlay

You can apply device tree overlays using TorizonCore Builder(3). First, clone the device tree overlays repository(3):

$ git clone -b toradex_6.6-2.1.x-imx git://git.toradex.com/device-tree-overlays.git device-trees

(3)

Then modify an existing LVDS overlay or create a custom one with the 18-bit JEIDA configuration, and deploy it using(3):

$ torizoncore-builder dto deploy --remote-host <YOUR_IP> --remote-username torizon --remote-password <PASSWORD> --force --reboot <your-custom-overlay>.dts

(3)

Troubleshooting White Screen Issues

If you’re seeing a white screen, common issues include(4):

  1. Incorrect timing parameters for your specific panel
  2. Wrong data mapping or bit depth configuration
  3. Missing or incorrect panel power/enable sequences
  4. Incompatible overlay compilation

Make sure your overlay is compiled for the correct kernel version and that all timing parameters match your 6.5" panel specifications.

Best regards, Toradex AI Assistant.

Did you like my answer? :+1: :-1:

If I answered your question, please tick the “Solution” checkbox.

For follow-up questions to me, please use @ToradexAI in your post.

5

Hi @Paras ,
I hope the issue is solved, let me know otherwise

6

Hi sahil
Thank you for the response.

The issue still persists. We have tested the JEIDA-24, SPWG, and VESA-24 configurations; however, the problem remains unresolved. The displayed image appears as shown in the attached screenshot, with an overlay also present. Additionally, the observed frame rate is approximately 114-119 FPS.

IMG20260203121051.jpg
IMG20260203121051.jpg1920×1440 414 KB

DummyOverlay.dts (2.7 KB)

Thank you

Regards,
Paras Electronics.