I'm using a HAT that among other things has a PCF8563 real-time clock on it (fed by a supercap when the Pi is off.)
I can use i2cdetect to see the device on bus 1, but the rtc-pcf8563 module does not see it, and the i2c-rtc dtoverlay does not use it.
pi@crunch:~ $ sudo modprobe rtc-pcf8563
pi@crunch:~ $ lsmod | grep rtc
rtc_pcf8563 7056 0
pi@crunch:~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- 51 -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
pi@crunch:~ $ ls /dev/rtc
ls: cannot access /dev/rtc: No such file or directory
pi@crunch:~ $ grep i2c-rtc /boot/config.txt
dtoverlay=i2c-rtc,param=pcf8563
pi@crunch:~ $
I've tried the AdaFruit walkthrough and a few other web searches. From what I can tell, what I'm doing should recognize the chip, and turn it to "UU" (as in, reserved by driver) However, I can't get /dev/rtc to show up.
dmesg | grep 8563
is empty, as is
dmesg | grep -i rtc