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| author | Sam Ravnborg <sam@ravnborg.org> | 2019-01-19 12:00:28 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2019-01-22 20:56:52 +0300 |
| commit | 8c12af15e7340a14e2978814ef28df58962283d6 (patch) | |
| tree | da68280cb8c57bec9ae4f055ba5ac28d83c8fa58 /Documentation/devicetree/bindings/rtc | |
| parent | d08fd7c1b9bd78b10345d2f9b115c5fd362b75cd (diff) | |
| download | linux-8c12af15e7340a14e2978814ef28df58962283d6.tar.xz | |
dt-binding: pcf8523: add xtal load capacitance
The NXP pcf8523 supports two different xtal load capacitance
- 7000fF (7pF) HW default
- 12500fF (12.5pF) Minimum power consumption, driver default
To obtain a precise RTC the pcf8523 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>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'Documentation/devicetree/bindings/rtc')
| -rw-r--r-- | Documentation/devicetree/bindings/rtc/nxp,pcf8523.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,pcf8523.txt b/Documentation/devicetree/bindings/rtc/nxp,pcf8523.txt new file mode 100644 index 000000000000..0b1080c60f63 --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/nxp,pcf8523.txt @@ -0,0 +1,18 @@ +* NXP PCF8523 Real Time Clock + +Required properties: +- compatible: Should contain "nxp,pcf8523". +- 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 12500fF. + +Example: + +pcf8523: rtc@68 { + compatible = "nxp,pcf8523"; + reg = <0x68>; + quartz-load-femtofarads = <7000>; +}; diff --git a/Documentation/devicetree/bindings/rtc/rtc.txt b/Documentation/devicetree/bindings/rtc/rtc.txt index 0cacbc0edd20..27a7c1578f6e 100644 --- a/Documentation/devicetree/bindings/rtc/rtc.txt +++ b/Documentation/devicetree/bindings/rtc/rtc.txt @@ -56,7 +56,6 @@ microcrystal,rv3029 Real Time Clock Module with I2C-Bus microcrystal,rv8523 Real Time Clock nxp,pcf2127 Real-time clock nxp,pcf2129 Real-time clock -nxp,pcf8523 Real-time Clock nxp,pcf8563 Real-time clock/calendar nxp,pcf85063 Tiny Real-Time Clock pericom,pt7c4338 Real-time Clock Module |