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.
Add an 'offset' nvmem cell which can be used to store a 32-bit offset
from the Unix epoch so that the RTC time can be updated on such
platforms.
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
.../devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml b/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml
index 21c8ea08ff0a..b95a69cc9ae0 100644
--- a/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml
+++ b/Documentation/devicetree/bindings/rtc/qcom-pm8xxx-rtc.yaml
@@ -40,6 +40,16 @@ properties:
description:
Indicates that the setting of RTC time is allowed by the host CPU.
+ nvmem-cells:
+ items:
+ - description:
+ four-byte nvmem cell holding a little-endian offset from the Unix
+ epoch representing the time when the RTC timer was last reset
+
+ nvmem-cell-names:
+ items:
+ - const: offset
+
wakeup-source: true
required:
@@ -69,6 +79,8 @@ examples:
compatible = "qcom,pm8921-rtc";
reg = <0x11d>;
interrupts = <0x27 0>;
+ nvmem-cells = <&rtc_offset>;
+ nvmem-cell-names = "offset";
};
};
};
--
2.39.1