IMX8MP Command mode support in LCDIFv3

[persandberg]

Hi,

The LCDIF interface in IMX8mm/mn support self_refresh_aware feature for displays that have a internal memory framebuffer. But the LCDIFv3 for IMX8MP seems not. My goal is to use command mode to lower the refresh rate to the panel which is a Startek KD055FHOIN031 with a CH13721C display controller that includes a internal fram buffer.

It is decribed in the reference manual of the IMX8MP how to configure the MIPI DSC driver to use command mode but I can not find a Linux driver that has implement that.

[Bio_TICFSL]

Hello,

The LCDIFv3 in IMX8MP does not have the same self_refresh_aware feature that's available in IMX8MM/MN. Your goal to use command mode to lower the refresh rate for your Startek KD055FHOIN031 display with CH13721C controller (which has an internal framebuffer) is technically feasible, but requires custom implementation.

While the IMX8MP reference manual describes how to configure the MIPI DSC driver for command mode, there isn't a Linux driver that has implemented this functionality out of the box. You would need to develop a custom implementation based on the reference manual guidelines.

For panels with internal framebuffers, the typical approach is to:

1. Create a custom panel driver that extends the existing MIPI DSI framework
2. Implement the command mode operations specific to your CH13721C controller
3. Add refresh rate control via the command mode interface

This implementation would require modifying the display driver to utilize the command mode capabilities described in the IMX8MP reference manual and to properly communicate with your display controller's internal framebuffer features.

If you need specific implementation assistance, NXP Professional Services could provide more detailed support for this custom development work.

Regards