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+--- Thread: SOQuartz Model A baseboard Real-Time Clock (/showthread.php?tid=18876)
SOQuartz Model A baseboard Real-Time Clock - stormwyrm - 11-17-2023
There appears to be some kind of real-time clock on the SOQuartz Model A Baseboard, maybe even two, but I can't seem to get them to work. I bodged together a CR2032 holder and a JST-PH 2mm header which fits the connector on the board that is labelled "RTC". Verified with a multimeter that the battery has 3V across the terminals so it seems like it's plugged in properly, but I'm still getting "rtc rtc0: Power loss detected, invalid time, rtc-pcf85063 1-0051: hctosys unable to read the hardware clock" in dmesg. There seems to also be a /dev/rtc1 (rk808-rtc) that seems responsive to hwclock but on every reboot it reverts to August 5, 2017 09:00 UTC for some reason.
Anyone know the correct way to provide power to the RTC?
RE: SOQuartz Model A baseboard Real-Time Clock - stormwyrm - 11-19-2023
I'm beginning to strongly suspect that I may have a bad oscillator or something on my board. Is anyone else experiencing similar trouble with their RTCs? I had a look at the kernel driver for the PCF85063 and what it does is check the OS flag (bit 7) on the seconds register (0x04) and if it is set it issues the power loss detected warning. According to the datasheet, if this bit is set that means: "clock integrity is not guaranteed; oscillator has stopped or has been interrupted". I'm pretty sure that there's power to the chip: I even used a multimeter to measure the voltage between pins 8 (VDD) and pin 4 (VSS) on the PCF85063 on the board and it is indeed at 3.2v or so.
Anyone else have the same board and are you also seeing the same kernel warning about power loss detected from rtc0? With the way it is wired up, with board power and battery power all being routed through a Schottky barrier diode (D3 on page 8 of the schematics) we should never be getting the message at all even without a battery I should think.