Re: [PATCH 0/4] rtc/scmi: Support multiple RTCs

Alexandre Belloni
2025-02-13T12:54:51Z

On 13/02/2025 21:35:50+0800, Peng Fan wrote:
> >Well, yes, you have your answer here, if the firmware knows RTC1 is more
> >accurate and will be your source of truth, then simply use this one.
>
> But issue is RTC1 is only readable to Linux non-safety, Linux not able
> to set alarm. Linux could only use RTC0 for alarm with current i.MX95 EVK
> firmware.
>
> If RTC1 could be exported to linux for control, we could for sure
> switch to using RTC1 without caring about RTC0. But this is not true.
>
> RTC0 is free for linux to control, RTC1 not. Switching to RTC1 will make
> us lose RTC alarm to wake up linux feature.
>

This doesn't make any sense, this limitation is on your firmware side,
either RTC1 has alarm support and the firmware can set the alarm for
linux or it doesn't and then, the firmware must set the time and alarm
on RTC0.

--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering