Rasclock (PCF2127 ) Hardware Clock FreeBSD 12.0

[Stefan Parvu]

> 
> I'd think the nxprtc driver would be much more likely to work.


+1. Many thanks. I do not know all drivers but your advice helped me a lot.
I will need to test to see if this works with PCF2127, PCF2129AT and other variants.
I will post later the results.

Im posting here, maybe somebody else might have same issues like me:

How to enable NXP PCF2127 RTC 

1. Load the correct driver

   * Manual

     # kldload nxprtc

   * Automatic, permanent 
 
     # vi /boot/loader.conf
     add nxprtc_load=“YES" 

2. Copy the i2c-rtc file to overlays directory
 
     # cp i2c-rtc.dtbo /boot/msdos/overlays/
     Source file: https://github.com/raspberrypi/firmware/tree/master/boot/overlays <https://github.com/raspberrypi/firmware/tree/master/boot/overlays> 

3. Enable the driver under config.txt 

    # vi /boot/msdos/config.txt 
    add dtoverlay=i2c-rtc,pcf2127

4. Reboot and validate yu can see the driver attached and functional.

After reboot you should see something like this:

$ dmesg | grep nxp
nxprtc0: <NXP PCF2127 RTC> at addr 0xa2 on iicbus0
nxprtc0: WARNING: RTC battery is low
nxprtc0: registered as a time-of-day clock, resolution 0.015625s

$ sysctl -b hw.fdt.dtb | dtc -I dtb -O dts | grep pcf
			pcf2127 at 51 {
				compatible = "nxp,pcf2127";

Thanks,
Stefan