[PATCHv1 0/3] Enable RTC on Odroid N2

[Neil Armstrong]

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.

Neil

> 
> Neil
> 
>>
>> real    0m0.002s
>> user    0m0.001s
>> sys     0m0.002s
>>
>> -Anand
>>
>