Re: [PATCH 1/4] dt-bindings: rtc: qcom-pm8xxx: add uefi-variable offset
From: Rob Herring (Arm)
Date: Fri May 09 2025 - 13:08:13 EST
On Wed, 23 Apr 2025 09:51:40 +0200, Johan Hovold wrote:
> On many Qualcomm platforms the PMIC RTC control and time registers are
> read-only so that the RTC time can not be updated. Instead an offset
> needs be stored in some machine-specific non-volatile memory, which a
> driver can take into account.
>
> On platforms where the offset is stored in a Qualcomm specific UEFI
> variable the variables are also accessed in a non-standard way, which
> means that the OS cannot assume that the variable service is available
> by the time the RTC driver probes.
>
> Add a 'qcom,uefi-rtc-info' boolean flag to indicate that the RTC offset
> is stored in a Qualcomm specific UEFI variable so that the OS can
> determine whether to wait for it to become available.
>
> The UEFI variable is
>
> 882f8c2b-9646-435f-8de5-f208ff80c1bd-RTCInfo
>
> and holds a 12-byte structure where the first four bytes is a GPS time
> offset in little-endian byte order.
>
> Link: https://lore.kernel.org/all/aAecIkgmTTlThKEZ@xxxxxxxxxxxxxxxxxxxx/
> Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml | 6 ++++++
> 1 file changed, 6 insertions(+)
>
Acked-by: Rob Herring (Arm) <robh@xxxxxxxxxx>