The MCA implements a real-time clock (RTC) in its firmware. On the ConnectCore 8X the internal CPU RTC is disabled because the MCA implementation handles power consumption more efficiently.
To keep the date during power-off you must connect a coin cell battery to the board.
Kernel configuration
You can manage the MCA RTC driver support through the following kernel configuration option:
-
Digi ConnectCore SOMs Micro Controller Assist RTC (CONFIG_RTC_DRV_MCA)
This option is enabled as built-in on the default ConnectCore 8X kernel configuration file.
Kernel driver
The MCA GPIO driver is located at:
| File | Description |
|---|---|
MCA RTC driver |
Device tree bindings and customization
The MCA RTC device tree binding is documented at Documentation/devicetree/bindings/rtc/digi,mca-rtc.txt.
RTC inside the MCA
ConnectCore 8X device tree
mca_cc8x: mca@63 {
...
rtc {
compatible = "digi,mca-cc8x-rtc";
};
};