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From: Johan Hovold <johan+linaro@kernel.org>
To: Alexandre Belloni <alexandre.belloni@bootlin.com>,
	Bjorn Andersson <andersson@kernel.org>
Cc: Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Konrad Dybcio <konradybcio@kernel.org>,
	linux-arm-msm@vger.kernel.org, linux-rtc@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	Johan Hovold <johan+linaro@kernel.org>
Subject: [PATCH 3/4] arm64: dts: qcom: sc8280xp-x13s: describe uefi rtc offset
Date: Wed, 23 Apr 2025 09:51:42 +0200	[thread overview]
Message-ID: <20250423075143.11157-4-johan+linaro@kernel.org> (raw)
In-Reply-To: <20250423075143.11157-1-johan+linaro@kernel.org>

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.

Use the new 'qcom,uefi-rtc-info' property to indicate that the offset is
stored in a UEFI variable so that the OS can determine whether to wait
for it to become available.

Fixes: 409803681a55 ("arm64: dts: qcom: sc8280xp-x13s: switch to uefi rtc offset")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
index 8000254f4db5..66c39765225f 100644
--- a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
+++ b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
@@ -1090,6 +1090,8 @@ &pmk8280_pon_resin {
 };
 
 &pmk8280_rtc {
+	qcom,uefi-rtc-info;
+
 	status = "okay";
 };
 
-- 
2.49.0


  parent reply	other threads:[~2025-04-23  7:54 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-23  7:51 [PATCH 0/4] rtc: pm8xxx: fix uefi offset lookup Johan Hovold
2025-04-23  7:51 ` [PATCH 1/4] dt-bindings: rtc: qcom-pm8xxx: add uefi-variable offset Johan Hovold
2025-05-09 17:08   ` Rob Herring (Arm)
2025-04-23  7:51 ` [PATCH 2/4] rtc: pm8xxx: fix uefi offset lookup Johan Hovold
2025-04-23  7:51 ` Johan Hovold [this message]
2025-04-23  7:51 ` [PATCH 4/4] arm64: dts: qcom: x1e80100: describe uefi rtc offset Johan Hovold
2025-05-07  7:54 ` [PATCH 0/4] rtc: pm8xxx: fix uefi offset lookup Johan Hovold
2025-05-20  7:41   ` Johan Hovold
2025-05-24 21:57 ` (subset) " Alexandre Belloni
2025-06-12  4:00 ` Bjorn Andersson

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