Re: [PATCH 02/13] ARM: dts: broadcom: bcm2835-rpi: Move non simple-bus nodes to root level

[Marek Szyprowski <m.szyprowski@samsung.com>]

On 07.01.2026 03:09, Rob Herring (Arm) wrote:
> The 'gpu' and 'firmware' nodes are not MMIO devices, so they should not be
> under a 'simple-bus'. Additionally, the "raspberrypi,bcm2835-power" node
> is part of the firmware, so move it under the /firmware node.
>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

This breaks operation of all drivers under the firmware node. I'm not 
exactly sure why, but they are not properly instantiated. It must be 
something specific to "firmware" name, but I didn't dig enough to find 
exactly where and why.

After changing the "/firmware" node name "xfirmware" everything works again:


diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi.dtsi 
b/arch/arm/boot/dts/broadcom/bcm2835-rpi.dtsi
index 9ab70b519a63..464f032ccb71 100644
--- a/arch/arm/boot/dts/broadcom/bcm2835-rpi.dtsi
+++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi.dtsi
@@ -1,7 +1,7 @@
  #include <dt-bindings/power/raspberrypi-power.h>

  / {
-       firmware: firmware {
+       firmware: xfirmware {
                 compatible = "raspberrypi,bcm2835-firmware", "simple-mfd";
                 mboxes = <&mailbox>;


Same issue occurs with bcm2712 change (patch 3/13).


> ---
>   arch/arm/boot/dts/broadcom/bcm2835-common.dtsi |  7 ++++---
>   arch/arm/boot/dts/broadcom/bcm2835-rpi.dtsi    | 16 ++++++++--------
>   2 files changed, 12 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi b/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi
> index 9261b67dbee1..1e76b290510d 100644
> --- a/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi
> +++ b/arch/arm/boot/dts/broadcom/bcm2835-common.dtsi
> @@ -141,9 +141,10 @@ v3d: v3d@7ec00000 {
>   			interrupts = <1 10>;
>   		};
>   
> -		vc4: gpu {
> -			compatible = "brcm,bcm2835-vc4";
> -		};
> +	};
> +
> +	vc4: gpu {
> +		compatible = "brcm,bcm2835-vc4";
>   	};
>   };
>   
> diff --git a/arch/arm/boot/dts/broadcom/bcm2835-rpi.dtsi b/arch/arm/boot/dts/broadcom/bcm2835-rpi.dtsi
> index e9bf41b9f5c1..9ab70b519a63 100644
> --- a/arch/arm/boot/dts/broadcom/bcm2835-rpi.dtsi
> +++ b/arch/arm/boot/dts/broadcom/bcm2835-rpi.dtsi
> @@ -1,15 +1,13 @@
>   #include <dt-bindings/power/raspberrypi-power.h>
>   
>   / {
> -	soc {
> -		firmware: firmware {
> -			compatible = "raspberrypi,bcm2835-firmware", "simple-mfd";
> -			mboxes = <&mailbox>;
> +	firmware: firmware {
> +		compatible = "raspberrypi,bcm2835-firmware", "simple-mfd";
> +		mboxes = <&mailbox>;
>   
> -			firmware_clocks: clocks {
> -				compatible = "raspberrypi,firmware-clocks";
> -				#clock-cells = <1>;
> -			};
> +		firmware_clocks: clocks {
> +			compatible = "raspberrypi,firmware-clocks";
> +			#clock-cells = <1>;
>   		};
>   
>   		power: power {
> @@ -17,7 +15,9 @@ power: power {
>   			firmware = <&firmware>;
>   			#power-domain-cells = <1>;
>   		};
> +	};
>   
> +	soc {
>   		vchiq: mailbox@7e00b840 {
>   			compatible = "brcm,bcm2835-vchiq";
>   			reg = <0x7e00b840 0x3c>;
>
Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland