It took me 1/2 hour to have DS18B20 working on Ubuntu following my method (removing all errors founded). Here it is a copy of my lab notebook:
sudo xzcat rockpi-4b-ubuntu-focal-server-arm64-20220801-0355-gpt.img.xz | dd of=/dev/mmcblk1 bs=1M
#url ssh: rockpi-4b.local
#login/pw: rock/rock
sudo apt-get update -y
sudo apt-get -y install rockpi4-dtbo
sudo nano /boot/hw_intfc.conf
désactiver les consoles: #intfc:dtoverlay=console-on-ttyS2 et #intfc:dtoverlay=console-on-ttyS4
sudo nano /boot/extlinux/extlinux.conf
#remove console=ttyFIQ0,1500000n8 and console=ttyS2,1500000n8
sudo reboot
############################
Removing errors messages
############################
dmesg | grep w1
[ 20.024497] rockchip-pinctrl pinctrl: unable to find group for node w1_pins
[ 20.028947] w1-gpio: probe of onewire@0 failed with error -22
sudo apt-get -y install device-tree-compiler
sudo nano new_w1-gpio.dts
#copy and paste next lines*************************************
/dts-v1/;
/plugin/;
/ {
compatible = “rockchip,rockpi”,“rockchip,rk3399”;
fragment@0 {
target-path = "/";
__overlay__ {
w1: onewire@0 {
compatible = "w1-gpio";
pinctrl-names = "default";
gpios = <&gpio4 30 0>;
status = "okay";
};
};
};
};
#end copy/paste ***********************************************
sudo mv /boot/overlays/w1-gpio4-30.dtbo /boot/overlays/w1-gpio4-30.old
sudo dtc -I dts -O dtb -o /boot/overlays/w1-gpio4-30.dtbo new_w1-gpio.dts
sudo reboot
###################
CHECKING RESULT
###################
dmesg | grep w1
[ 18.592842] w1_master_driver w1_bus_master1: Attaching one wire slave 10.000802e5e4d1 crc 3c
YEEEEEESSSSS !!!
cat /sys/bus/w1/devices/10-000802e5e4d1/w1_slave
35 00 4b 46 ff ff 07 10 98 : crc=98 YES
35 00 4b 46 ff ff 07 10 98 t=26312