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

 > 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 that the RTC driver could obtain
the existing rpi_firmware instance.

Based on your comment, I think it would be more appropriate to model
the RTC as a child device of rpi-firmware. The driver could then obtain
the firmware interface from its parent, rather than adding a phandle
solely for driver plumbing.

This would also mean moving the binding to
arm/bcm/raspberrypi,bcm2835-firmware.yaml.

Best regards,
Sander

On 9/9/26 17:54, Krzysztof Kozlowski wrote:

On 09/09/2026 17:47, Krzysztof Kozlowski wrote:

quoted

On 09/09/2026 16:12, Sander Speetjens wrote:

quoted

+
+  firmware:

There is no such generic property. You need vendor prefix. Wasn't this
already discussed for Rpi? I feel like every time contributors send
downstream DTS ignoring what was discussed upstream.

quoted

+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Phandle to the Raspberry Pi firmware device.

You said nothing more than property name and type. Explain what for.

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).

Best regards,
Krzysztof