[PATCHv1 0/3] Enable RTC on Odroid N2

[Anand Moon]

hi Neil,

On Thu, 16 Jul 2020 at 14:05, Neil Armstrong <narmstrong at baylibre.com> wrote:
>
> Hi,
>
> On 16/07/2020 10:20, Neil Armstrong wrote:
> > Hi,
> >
> > On 16/07/2020 10:14, Anand Moon wrote:
> >> Hi Neil,
> >>
> >> Thanks for your review comments.
> >>
> >> On Thu, 16 Jul 2020 at 12:35, Neil Armstrong <narmstrong at baylibre.com> wrote:
> >>>
> >>> Hi Anand,
> >>>
> >>> Only the vrtc is able to wakeup the device from suspend,
> >>> the external RTC is not capable.
> >>>
> >>> Neil
> >>
> >> Now I have two RTC driver registered
> >>
> >> $ dmesg | grep rtc
> >> [    4.737315] rtc-pcf8563 0-0051: registered as rtc0
> >> [    4.738763] rtc-pcf8563 0-0051: setting system clock to
> >> 2020-07-16T08:00:46 UTC (1594886446)
> >> [    4.790206] meson-vrtc ff8000a8.rtc: registered as rtc1
> >>
> >> And there are two nodes
> >> # ls /dev/rtc*
> >> /dev/rtc  /dev/rtc0  /dev/rtc1
> >>
> >> So it seames an issue that /dev/rtc0 is not able to handle wakeup events.
> >> How can we resolve this issue?
> >>
> >> # time rtcwake -s 30 -m mem
> >> rtcwake: /dev/rtc0 not enabled for wakeup events
> >
> > rtcwake -d /dev/rtc1 -s 30 -m mem
> >
> > As Christian reported off-list, it may be necessary to keep the vrtc as rtc0,
> > so you should add aliases in the odroid-n2 DT to have vrtc as rtc0 and the on-board
> > rtc as rtc1, but it may break the hwclock tools, so the reverse may be better
> > but you'll need to specify rtc1 to rtcwake.
>
> While looking closer to the Odroid-N2 schematics and U-Boot/SCP Firmware, the external on-board
> RTC can wake the device with the GPIO_AO 7, and wakeup is enabled in:
> https://github.com/hardkernel/u-boot/blob/odroidn2-v2015.01/board/hardkernel/odroidn2/firmware/scp_task/pwr_ctrl.c#L143
>
> So, something must be missing.
>
Ok I have missed this setting.
But I could not find any more information on this configuration
in S922X_Public_Datasheet_V0.2-Hardkernel,

But HK uses the same set up as we do.
https://github.com/hardkernel/linux/blob/odroidn2-4.9.y/arch/arm64/boot/dts/amlogic/mesong12_odroid_common.dtsi#L322-L333
I could not gather much input from this configration.

Does VIM3 support VRTC or do they prefer rtc wakeup via RTC ?

-Anand