ds3231 suddenly failing

[Jukka Ukkonen]

Hello all,

Previously my RPI2 had no problems with ds3231 RTC.
Now 11.0-CURRENT r295206 shows these during boot...

ds32310: <Maxim DS3231 RTC> at addr 0x1a0 on iicbus1
ds32310: cannot read from RTC.

Trying sysctl dev.ds3231 gives me this...

dev.ds3231.0.%parent: iicbus1
dev.ds3231.0.%pnpinfo: name=rtc compat=maxim,ds3231
dev.ds3231.0.%location: addr=0x1a0
dev.ds3231.0.%driver: ds3231
dev.ds3231.0.%desc: Maxim DS3231 RTC
dev.ds3231.%parent:

Trying "i2c -s" does not show anything on either
/dev/iic0 or /dev/iic1.

AFAIK I have not changed anything in the build.

Checking the contents of rpi2.dtb says this about
the clock chip...

                        rtc {
                                compatible = "maxim,ds3231";
                                reg = <0xd0>;
                        };

I guess that the alert "cannot read from RTC." is
due to the fact that "addr 0x1a0" does not match
"reg = <0xd0>;" in the DTB. It just does not dawn
to me where the kernel found the alternate value.
Any ideas?

--jau