diff options
| author | Sam Ravnborg <sam@ravnborg.org> | 2019-01-19 10:00:29 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2019-01-22 18:57:06 +0100 |
| commit | e4a604cbee5470fc116ac9a4f852152070984286 (patch) | |
| tree | b454cc8fcf4743f8364b8faa84b5a8e87415a050 /Documentation | |
| parent | 8c12af15e7340a14e2978814ef28df58962283d6 (diff) | |
| download | linux-e4a604cbee5470fc116ac9a4f852152070984286.tar.bz2 | |
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>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/nxp,pcf85063.txt | 18 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/rtc.txt | 1 |
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 |