STM32MP151 - How to activate MCO ?

[CharlesBlanchard]

Hello, 

I'm trying to leverage the MCO capability of the STM32MP1, but I don't success. I want to have LSE on MCO1 and HSE on MCO2. 

I'm using TFA -> uboot -> linux and I can build with Yocto or Buildroot.

Which steps should be done during TFA, uboot and on Linux ? 

I have tried different combination but there is no behaviour.

Also, I'm only doing device tree configuration, maybe I'm missing something elsewhere.

I have seen following resource and I'm confused on the way to proceed because of the warning on MCO pins :

https://community.st.com/s/article/FAQ-STM32MP1-bring-up-troubleshooting-guide

Thanks for your input,

Best regards,

Charles B

[Olivier GALLIEN · Accepted solution]

Hi @Community member​ ,

Wiith Ecosystem version DV3.x and earlier, CubeMX not handle properly MCO configuration in Uboot and kernel DTS, which lead to a deadlock.

This is what is mentionned as a classical pitfall in https://community.st.com/s/article/FAQ-STM32MP1-bring-up-troubleshooting-guide

From DV4.0 this configuration is properly manage and MCO configuration is done in OPTEE.

If you want to remains in DV3.x or earlier version the w/a consist in using a dummy driver to manage MCO config as per already describe in this post

https://community.st.com/s/question/0D50X0000BDox5VSQR/clock-output-on-mco1-pin-stm32mp157

Hope it help

Olivier

[CharlesBlanchard]

Thanks for your answer. I will check what is the preferred solution in our case.

Regards,

Charles