Hi,
I have a PiCAN 2 Hat https://raspberry-valley.azurewebsites.net/ref/Raspberry-Pi-PICAN2-Hat-User-Guide.pdf on my Raspberry Pi 4. It was recognized as a can0 device in my old Raspberry PI OS (HA supervised install) and I only had to adjust config.txt according to the documentation.
Since I moved to Debian (in order to be in a supported state), this is no longer working because of missing device tree overlay support of the kernel.
I did a fresh supervised install with Debian bookworm (according to this description: Installing Home Assistant Supervised on a Raspberry Pi using Debian 12 ). I then loaded the missing kernel modules (as the PiCAN comes with a SPI MCP2515):
sudo echo mcp251x | sudo tee -a /etc/modules
I also tried adding the module spi-bcm2835 but that does not change things, no can0 device is detected.
The reason is that the device tree overlay (although I copied it from the Raspbian OS version and put it into /boot/firmware/overlays) probably does not get loaded (here the line from config.txt):
dtoverlay=mcp2515-can0,oscillator=16000000,interrupt=25
Does anyone know how to activate device tree overlays on the standard Debian kernels? Probably I need to recompile my own kernel for this hardware to get recognised?
It is a bummer that supervised HA installs now require Debian and do not support Raspberry PI OS. Given that many users run their HA on Raspberry PIs especially because it is so easy to implement your own hardware solutions there, Raspberry PI OS should also be supported for supervised install. That would help a lot.
Any help on getting to a kernel with dt-overlays is appreciated.