Linux DRM driver for Noritake GU-D series displays

• Touchscreen
• Brightness
• GPU accelerated rendering

The following installation instructions is intended for Raspberry Pi 4 and Raspbian OS 32 and 64 bit.

Get Driver Source

cd ~
git clone https://github.com/v-kiniv/noritake-gud-drm.git
cd ~/noritake-gud-drm

Install build tools and Linux headers

sudo apt install build-essential raspberrypi-kernel-headers

Build

make -j4

Install Overlay

sudo dtc -@ -I dts -O dtb -o /boot/overlays/noritake-gud-drm.dtbo ./gud.dts

Test

sudo dtoverlay noritake-gud-drm
sudo insmod ./gud.ko

If it's working, proceed with Install Driver and Configure sections to load driver on boot.

Install Driver

sudo make install

Configure

Driver can be enabled and configured using dtoverlay in /boot/config.txt.

Enable overlay with default configuration:

dtoverlay=noritake-gud-drm

Enable overlay with custom configuration(optional):

dtoverlay=noritake-gud-drm,speed=400000,busy-gpios=27,dithering=0

Set fixed clock for the GPU to avoid SPI clock exceeding maximum throughput of the display bus:

gpu_freq=250

Reboot

And, finally, reboot device to load the driver:

sudo reboot

Mesa

To enable GPU accelerated rendering, you will also need to build Mesa adapter driver: Adapter driver act as a bridge between Mesa and display driver.

UPD: as of kernel 6.6 and Mesa 23 this is not required, but when you run an OpenGL application, MESA will complain about missing gud_dri.so.

# make sure you have uncommented deb-src in /etc/apt/sources.list before running apt-get build-dep
sudo apt-get build-dep mesa
wget https://archive.mesa3d.org/mesa-20.0.0.tar.xz
tar xf mesa-20.0.0.tar.xz

You should be able to compile adapter driver for any version of Mesa, here we are compiling for 20.0.0

1. Add the following line after #if defined(GALLIUM_KMSRO) in file mesa-20.0.0/src/gallium/targets/dri/target.c

DEFINE_LOADER_DRM_ENTRYPOINT(gud)

2. Add the following line after foreach d : [[with_gallium_kmsro, [ in file mesa-20.0.0/src/gallium/targets/dri/meson.build:

'gud_dri.so',

3. Build:

cd mesa-20.0.0/
meson --prefix="${PWD}/build/install" build/
ninja -j4 -C build/
ninja -C build/ install

4. Install adapter driver

For 32bit OS run:

sudo cp build/install/lib/arm-linux-gnueabihf/dri/gud_dri.so /lib/arm-linux-gnueabihf/dri/

For 64bit OS run:

sudo cp build/install/lib/aarch64-linux-gnu/dri/gud_dri.so /lib/aarch64-linux-gnu/dri/

5. Test

sudo apt install kmscube
kmscube -D /dev/dri/card1

Console Blank

Add consoleblank=600 to /boot/cmdline.txt so it looks something like this:

console=serial0,115200 console=tty1 consoleblank=600 root=PARTUUID=a5507f56-02 rootfstype=ext4 fsck.repair=yes rootwait

Configure Console Font

sudo dpkg-reconfigure console-setup

Proceed with wizard and select Termius->6x12 (framebuffer only) font

Backlight / Display Power

Create udev rules to be able to change display brightness and power without sudo

echo 'SUBSYSTEM=="backlight",RUN+="/bin/chmod 666 /sys/class/backlight/%k/brightness /sys/class/backlight/%k/bl_power"' | sudo tee -a /etc/udev/rules.d/backlight-permissions.rules

Now you can control brightness by writing to the /brightness. Valid values are are 1 through 8.

# min brightness
echo 1 > /sys/class/backlight/gud/brightness

# max brightness
echo 8 > /sys/class/backlight/gud/brightness

And power by writing to the /bl_power

# power OFF
echo 4 > /sys/class/backlight/gud/bl_power

# power ON
echo 0 > /sys/class/backlight/gud/bl_power