[PATCH 3/3] arm64: dts: broadcom: Add RTC to Raspberry Pi 5 B

Krzysztof Kozlowski krzk at kernel.org
Wed Sep 9 08:47:31 PDT 2026


On 09/09/2026 16:13, Sander Speetjens wrote:
> The Raspberry Pi 5 contains a RTC on a custom DA9091 PMIC that is accesed trought the firware mailbox.
> This so we have a battery backed RTC, so the OS does not need network to get the time.
> 
> Signed-off-by: Sander Speetjens <sander.speetjens at gmail.com>
> ---
>  arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi b/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi
> index b7a6bc34ae1a..5a82dd585f32 100644
> --- a/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi
> +++ b/arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b-base.dtsi
> @@ -102,6 +102,13 @@ wl_on_reg: wl-on-reg {
>  		startup-delay-us = <150000>;
>  		enable-active-high;
>  	};
> +
> +	rpi_rtc: rpi-rtc {

Node names should be generic. See also an explanation and list of
examples (not exhaustive) in DT specification:
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
If you cannot find a name matching your device, please check in kernel
sources for similar cases or you can grow the spec (via pull request to
DT spec repo).

> +		compatible = "raspberrypi,rpi-rtc";
> +		firmware = <&firmware>;
> +		status = "okay";

Why?


Best regards,
Krzysztof



More information about the linux-arm-kernel mailing list