From e4a604cbee5470fc116ac9a4f852152070984286 Mon Sep 17 00:00:00 2001 From: Sam Ravnborg Date: Sat, 19 Jan 2019 10:00:29 +0100 Subject: [PATCH] dt-binding: pcf85063: add xtal load capacitance MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Sam Ravnborg Cc: Alessandro Zummo Cc: Alexandre Belloni Cc: Rob Herring Cc: Mark Rutland Cc: Urs Fässler Reviewed-by: Rob Herring Signed-off-by: Alexandre Belloni --- .../devicetree/bindings/rtc/nxp,pcf85063.txt | 18 ++++++++++++++++++ Documentation/devicetree/bindings/rtc/rtc.txt | 1 - 2 files changed, 18 insertions(+), 1 deletion(-) create mode 100644 Documentation/devicetree/bindings/rtc/nxp,pcf85063.txt 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