Use M7 core to control display on iMX8MN

[terry_lv]

This demo will demonstrate how to use M7 core to control display on i.MX8MN.

In this demo, generally, we'll add a MIPI-DSI and LCD driver to M7 SDK code and Linux kernel will pass display request to M7 core by rpmsg.

Function:

1. Linux kernel on A core will not handle mipi-dsi and it will send display request to M7 core by RPMSG.

2. M7 core will control MIPI-DSI, LCD and handle display request.

3. When kernel enter sleep, M7 core will show a 1 sec clock (from 0 - 7, updated every second) on screen. (See video for details.)

4. Please read readme.txt and other readme files in patch packages.

[gnulux]

Hi, 

Instead the clock i would like to display an image (bitmap) from the M7 when A53 is in supend mode. 

Do you think it is possible? 

In normal mode the A53 will display UI from weston. Does the M7 can manage that ? 

my hardware is IMX8MP  5.10 kernel

Regards

[terry_lv]

Hi,

  See reply below.

1. Instead the clock i would like to display an image (bitmap) from the M7 when A53 is in supend mode.
   Do you think it is possible?
   [Ty] It is possible, but it also depends on image size and DDR retention status in suspend.
   If the image size is small enough to fit TCM, it is possible to store the image in TCM.
   Otherwise, the DDR can't be put to retention when A53 in suspend.
   In this demo, due to TCM size limitation, we only display a 184x300 image on the LCD.
2. In normal mode the A53 will display UI from weston. Does the M7 can manage that ?
   [Ty] Yes. M7 should be able to manage it.

  Thanks!

Regards

Terry

[hfranco]

Hi @terry_lv,

Does this also work with iMX8M Plus? Kernel downstream 5.15? Or at least it's possible to make it work?

Best Regards,
Hiago.

[terry_lv]

Hi,

  This demo can be ported to work on i.MX8MP.

  But I'm not sure about the changes.

  This demo is created a long time ago and kernel, as well as SDK have changed a lot since then.

  Thanks!

Regards

Terry