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authorSam Ravnborg <sam@ravnborg.org>2019-01-19 10:00:29 +0100
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2019-01-22 18:57:06 +0100
commite4a604cbee5470fc116ac9a4f852152070984286 (patch)
treeb454cc8fcf4743f8364b8faa84b5a8e87415a050
parent8c12af15e7340a14e2978814ef28df58962283d6 (diff)
dt-binding: pcf85063: add xtal load capacitance
The NXP pcf85063 supports two different xtal load capacitance - 7000fF (7pF) HW default, Linux driver default - 12500fF (12.5pF) Minimum power consumption To obtain a precise RTC the pcf85063 must be configured with the correct capacitance load of the xtal. Add a property to specify the xtal capacitance load. The default value matches that of the current Linux driver. With a dedicated binding remove the entry in rtc.txt Signed-off-by: Søren Andersen <san@skov.dk> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Urs Fässler <urs.fassler@bbv.ch> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
-rw-r--r--Documentation/devicetree/bindings/rtc/nxp,pcf85063.txt18
-rw-r--r--Documentation/devicetree/bindings/rtc/rtc.txt1
2 files changed, 18 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/rtc/nxp,pcf85063.txt b/Documentation/devicetree/bindings/rtc/nxp,pcf85063.txt
new file mode 100644
index 000000000000..d3e380ad712d
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/nxp,pcf85063.txt
@@ -0,0 +1,18 @@
+* NXP PCF85063 Real Time Clock
+
+Required properties:
+- compatible: Should contain "nxp,pcf85063".
+- reg: I2C address for chip.
+
+Optional property:
+- quartz-load-femtofarads: The capacitive load of the quartz(x-tal),
+ expressed in femto Farad (fF). Valid values are 7000 and 12500.
+ Default value (if no value is specified) is 7000fF.
+
+Example:
+
+pcf85063: rtc@51 {
+ compatible = "nxp,pcf85063";
+ reg = <0x51>;
+ quartz-load-femtofarads = <12500>;
+};
diff --git a/Documentation/devicetree/bindings/rtc/rtc.txt b/Documentation/devicetree/bindings/rtc/rtc.txt
index 27a7c1578f6e..d86e2850fe1c 100644
--- a/Documentation/devicetree/bindings/rtc/rtc.txt
+++ b/Documentation/devicetree/bindings/rtc/rtc.txt
@@ -57,7 +57,6 @@ microcrystal,rv8523 Real Time Clock
nxp,pcf2127 Real-time clock
nxp,pcf2129 Real-time clock
nxp,pcf8563 Real-time clock/calendar
-nxp,pcf85063 Tiny Real-Time Clock
pericom,pt7c4338 Real-time Clock Module
ricoh,r2025sd I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC
ricoh,r2221tl I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC