Re: [PATCH] arm64: dts: s32g: force S32G RTC as rtc0

[Andrei Botila]

On 3/10/2026 3:14 PM, Fabio Estevam wrote:
> On Tue, Mar 10, 2026 at 9:50 AM Andrei Botila <andrei.botila@xxxxxxxxxxx> wrote:
>>
>> S32G RTC is probed after the RTC on RDB (PCA85073A) so the S32G RTC
>> ends up on /dev/rtc1. This causes the suspend/resume or hwclock to use
>> the wrong RTC since it takes by default rtc0.
>> Force the S32G RTC to be assigned rtc0.
> 
> We usually prefer to use the I2C RTC as rtc0 because it is battery-backed.
> 
> What's the exact problem with using the I2C RTC as rtc0?
> 
> Is the S32G RTC battery-backed?

Hello,

S32G RTC is not battery-backed.

Regarding the I2C RTC(PCA85073A) commands like hwclock or rtcwake use by
default /dev/rtc, /dev/rtc0 so they will try to use PCA and fail.

Also from what I could find online PCA85073A is also not battery-backed.

Thank you,
Andrei