XO 1.75 dual RTC synchronization

[pgf]

<smithbone> does the rtc driver work now?
<pgf> it's complicated.
<pgf> yes and no.
<cjb> smithbone: it works but it doesn't do what you think it does :-)
<pgf> there are two rtcs.
<pgf> one in the chip, and one not in the chip.
<wad> Damn Marvell
<pgf> the one inside isn't powered when the chip is off.
<pgf> so we have one outside that is.
<pgf> but the one outside doesn't have alarms.
<pgf> so if we want alarms, we have to use the one inside, while the system is running.
<pgf> so we have to sync the inner clock to the outer clock, at boot, and vice-versa on shutdown.

we'll have to explore how linux manages two RTC drivers.

[Quozl]

Triage. 1.75-software and 1.75-firmware.

[martin.langhoff]

apologies - wrong bug

[Quozl]

#10827 related.

[Quozl]

#11400 related.

[saadia]

The clock will not be synchronized. The external clock (idt1338) will be used for syncing time at startup and reboot by setting CONFIG_RTC_HCTOSYS_DEVICE to /dev/rtc1. During operation, /dev/rtc will be linked to /dev/rtc1 for hwclock's benefit. The internal SOC real time clock will be used for alarms, and will keep the time since boot.