[PATCHv1 0/3] Enable RTC on Odroid N2
Neil Armstrong
narmstrong at baylibre.com
Thu Jul 16 04:20:11 EDT 2020
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.
Neil
>
> real 0m0.002s
> user 0m0.001s
> sys 0m0.002s
>
> -Anand
>
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