Commit e4a604cb authored Jan 19, 2019 by Sam Ravnborg Committed by Alexandre Belloni Jan 22, 2019

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>

parent 8c12af15

Documentation/devicetree/bindings/rtc/nxp,pcf85063.txt

0 → 100644

+18 −0

Original line number	Diff line number	Diff line
		* 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>;
		};

Documentation/devicetree/bindings/rtc/rtc.txt

+0 −1

Original line number	Diff line number	Diff line
		@@ -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

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