>> There would be spare register but i think it should be in sync with hardware team. let me check with them and update back if any bit can be repurposed for this feature. I agree, if any register is available, it can programmed prior to kernel. >>> It would need to be reserved on all SoCs though (future and >>> past), to make sure the contract is always held up, but I >>> think finding a persistent bit that has never been used >>> shouldn't be impossible. >>> >> Yes, let me check it with hardware and firmware team and update back. Does this mean, there can't be a such software sharing mechanism (purely software decision) based on DTSI flag ? > > I suppose that depends on our needs. If we can set that bit > before Linux starts (i.e. in UEFI), we can avoid touching > the pinctrl state regardless of whether the other entities > have started up yet to avoid overcomplicating it. > > If we need Linux to set that bit, we would still need some > mechanism like a dt property. But I really think that the > bootloader should be burdened with this instead, given it > has a better understanding of the hardware due to it being > well, the bootloader). > > Krzysztof, I'm assuming that sounds sane from your > perspective too? Yes, sound okay. Best regards, Krzysztof