Re: [PATCH v2 10/14] arm64: dts: rp1: Add support for RaspberryPi's RP1 device

[Herve Codina]

Hi Andrea,

On Mon,  7 Oct 2024 14:39:53 +0200
Andrea della Porta <andrea.porta@xxxxxxxx> wrote:

> RaspberryPi RP1 is a multi function PCI endpoint device that
> exposes several subperipherals via PCI BAR.
> Add a dtb overlay that will be compiled into a binary blob
> and linked in the RP1 driver.
> This overlay offers just minimal support to represent the
> RP1 device itself, the sub-peripherals will be added by
> future patches.
> 
> Signed-off-by: Andrea della Porta <andrea.porta@xxxxxxxx>
> ---

...
> +/ {
> +	fragment@0 {
> +		target-path="";
> +		__overlay__ {
> +			compatible = "pci1de4,1";

The compatible is not needed here. Indeed, it will be added by the PCI core
when it scans the bus and adds the missing nodes.
  https://elixir.bootlin.com/linux/v6.12-rc2/source/drivers/pci/of_property.c#L383

> +			#address-cells = <3>;
> +			#size-cells = <2>;
> +
> +			pci_ep_bus: pci-ep-bus@1 {
> +				compatible = "simple-bus";
> +				ranges = <0xc0 0x40000000
> +					  0x01 0x00 0x00000000
> +					  0x00 0x00400000>;
> +				dma-ranges = <0x10 0x00000000
> +					      0x43000000 0x10 0x00000000
> +					      0x10 0x00000000>;
> +				#address-cells = <2>;
> +				#size-cells = <2>;
> +				interrupt-controller;
> +				interrupt-parent = <&pci_ep_bus>;
> +				#interrupt-cells = <2>;

Not sure this node should be an interrupt controller.
The interrupt controller is the PCI device itself (i.e.the node
where the overlay is applied).

Best regards,
Hervé