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>
--- /dev/null
+* 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>;
+};
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