Request for STM32L5 FDCAN Support in Zephyr

sbadiga · ‎2025-06-09

Hello ST Community,

I noticed that STM32L5 series (e.g., STM32L552) does not currently have official FDCAN support in Zephyr. The stm32l5.dtsi does not define an fdcan node, and there are no corresponding bindings or support in the driver layer for this series.

I’ve attempted to adapt the FDCAN configuration using references from STM32G4 and STM32U5 series. While I was able to build the device tree by manually adding a node with compatible = "st,stm32-fdcan", the runtime initialization fails—likely due to differences in clock setup or message RAM layout.

I would really appreciate guidance on the following:

Is there a plan to add STM32L5 FDCAN support officially in Zephyr?
What would be the correct fdcan node configuration in the .dtsi or overlay?
What values should be used for bosch,mram-cfg and what memory region is reserved for message RAM on STM32L552?
Are there any working examples or patches that can help enable FDCAN on STM32L5?

Any help or direction would be greatly appreciated.

Thanks!

Sai

Andrew Neil · ‎2025-06-09

Zephyr's feature request/tracking process:

https://docs.zephyrproject.org/latest/project/proposals.html

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.