Re: [PATCH 1/3] dt-bindings: rtc: Add Raspberry Pi 5 RTC binding

[Sander Speetjens <sander.speetjens@gmail.com>]

 >Whether device has separate node, depends on it having dedicated
 >resources. I don't see such here, so unlikely it should have a node in
 >the first place (see writing bindings or DTS101 where exactly this
 >question is asked).

I think you are right there is no extra node needed (only 
the trickle-voltage-millivolt property) and it could move directly into 
the rpi_firmware node without creating an extra node.

Kind regards
Sander

On 9/10/26 09:08, Krzysztof Kozlowski wrote:
> On 09/09/2026 22:24, Sander Speetjens wrote:
>> Thanks for your response
>>
>>> And more important, where is any interface to actually control the RTC?
>>> I see nothing, so your firmware is? Then this is not a separate device
>>> and you just added DTS for your driver, which is a no go (see writing
>>> bindings).
>> The RTC is a physical, battery-backed RTC, but the Raspberry Pi firmware
>> exposes its register interface exclusively through the firmware mailbox.
>> I initially used a firmware phandle so the RTC driver could obtain the
>> existing rpi_firmware instance.
>>
>> Based on your comment, I think it is more appropriate to model
>> the RTC as a child device of rpi-firmware,
>> referencing to the existing firmware clock/reset/power services,
>> and have the driver obtain the firmware interface from its parent
>> rather than adding a phandle solely for driver plumbing.
>> Which also means moving this to arm/bcm/raspberrypi,bcm2835-firmware.yaml
>>
> Whether device has separate node, depends on it having dedicated
> resources. I don't see such here, so unlikely it should have a node in
> the first place (see writing bindings or DTS101 where exactly this
> question is asked).
>
> Best regards,
> Krzysztof