The issue about PCF85063 drver on linux

[arknights]

Hi,

I use linux-4.14 official driver: rtc-pcf85063.c and add it to dts.

I can operate pcf85063 register directly through i2c.

But when I use driver, it has error:

[    7.453848] rtc-pcf85063 0-0051: Power loss detected, invalid time
[    7.460208] rtc-pcf85063 0-0051: rtc core: registered rtc-pcf85063 as rtc0

Then I check drive code:

/ if the clock has lost its power it makes no sense to use its time /
if (regs[0] & PCF85063_REG_SC_OS) {
       dev_warn(&client->dev, "Power loss detected, invalid time\n");
       return -EINVAL;
}

So, what should i do?

[JozefKozon]

Hi Arknights,

please see this link for a similar issue: https://community.nxp.com/t5/i-MX-Processors/RTC-issue-pca8565/m-p/916395

Do you have used a supercapacitor or a battery as a back-up supply?

With Best Regards,

Jozef

[arknights]

Hi Jozef,

Yes, we use a supercapacitor.
After our device power off, the supercapacitor power supply for rtc, time in rtc continue run.

Add attachment is our circuit diagram.

Thanks