Android 10 and official Raspberry Pi Display

#1

I am unable to get the official Raspberry Pi display working on Android 10, that I am building from source. The image boots properly and I am able to access it via an external HDMI display, but the Pi display is black. The Pi display is working on Ubuntu and an Android 9 image downloaded from the wiki.

I am using the manifests repository here: https://github.com/radxa/manifests/tree/rockchip-android-10

Any pointers would be greatly appreciated.

[ROM][Android10][RockPI 4] Android Q Firmware Release
#2

I am an experienced sw engineer with a keen interest in Android internal, but I am new to device trees and DSI displays. I have already spent a good couple of days investigating this issue and so far I have made the following observations:
Btw, I am using a Rock Pi 4 B+.

  1. device/rockchip/rk3399/BoardConfig.mk:
    PRODUCT_KERNEL_DTS points to rk3399-sapphire-excavator-edp-avb. I have no idea how this file relates to the Rock Pi 4B+
    I modified the file to point to rk3399-rockpi-4b instead
  2. rk3399-rockpi-4b:
    line 334 points to compatible =“simple-panel-dsi”;
    As far as I can tell, this corresponds to the driver kernel/drivers/gpu/drm/panel/panel-simple.c which seems to represent a generic dsi display panel, please correct me if this wrong.
  3. The only specific reference to the raspberry pi display I can find, is the touch screen driver found at kernel/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c which does not seem to feature in any of the referenced dts/dtsi files.
  4. As I understand it, the Raspberry Pi display uses a Toshiba TC358762 bridge chip, to bridge between DSI and DPI. I cannot find find a kernel driver for this chip in the kernel referenced in the Android 10 source tree. The closest I can find is kernel/drivers/gpu/drm/bridge/tc358767.c.

Taking all of this into account it seems as if there is quite allot of work still required to get the Raspberry Pi display working.

#3

Hi,
may you help me to find the Android 9 image you used for the test and where the DSI display working?
If you may post the link here would be appreciate.
Thanks