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| author | Johan Hovold <johan+linaro@kernel.org> | 2025-04-23 09:51:40 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2025-05-24 23:39:41 +0200 |
| commit | b23b91d56863d280af81c9ca11594484782ceea5 (patch) | |
| tree | 66644709193e204a7adbaff4b79e7562b6cb5816 | |
| parent | 7498dca1d0d17c16a21f0e27fbb6414cf2645289 (diff) | |
dt-bindings: rtc: qcom-pm8xxx: add uefi-variable offset
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@hovoldconsulting.com/
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250423075143.11157-2-johan+linaro@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml b/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml index 68ef3208c886..7497dc3ac5b2 100644 --- a/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml +++ b/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml @@ -55,6 +55,12 @@ properties: description: RTC alarm is not owned by the OS + qcom,uefi-rtc-info: + type: boolean + description: + RTC offset is stored as a four-byte GPS time offset in a 12-byte UEFI + variable 882f8c2b-9646-435f-8de5-f208ff80c1bd-RTCInfo + wakeup-source: true required: |