Re: [PATCH v2 2/4] arm64: dts: qcom: x1e80100: add bus topology for PCIe domain 3

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 4/28/25 1:16 PM, Johan Hovold wrote:
> On Sat, Apr 26, 2025 at 12:44:57PM +0200, Konrad Dybcio wrote:
>> On 4/25/25 1:55 PM, Johan Hovold wrote:
>>> On Fri, Apr 25, 2025 at 12:22:56PM +0200, Konrad Dybcio wrote:
>>>> On 4/25/25 11:29 AM, Wenbin Yao wrote:
>>>>> From: Qiang Yu <quic_qianyu@quicinc.com>
>>>>>
>>>>> Add pcie3port node to represent the PCIe bridge of PCIe3 so that PCI slot
>>>>> voltage rails can be described under this node in the board's dts.
>>>>>
>>>>> Signed-off-by: Qiang Yu <quic_qianyu@quicinc.com>
>>>>> Signed-off-by: Wenbin Yao <quic_wenbyao@quicinc.com>
>>>>> ---
>>>>>  arch/arm64/boot/dts/qcom/x1e80100.dtsi | 11 +++++++++++
>>>>>  1 file changed, 11 insertions(+)
>>>>>
>>>>> diff --git a/arch/arm64/boot/dts/qcom/x1e80100.dtsi b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
>>>>> index 46b79fce9..430f9d567 100644
>>>>> --- a/arch/arm64/boot/dts/qcom/x1e80100.dtsi
>>>>> +++ b/arch/arm64/boot/dts/qcom/x1e80100.dtsi
>>>>> @@ -3287,6 +3287,17 @@ opp-128000000 {
>>>>>  					opp-peak-kBps = <15753000 1>;
>>>>>  				};
>>>>>  			};
>>>>> +
>>>>> +			pcie3port: pcie@0 {
>>>>
>>>> @0,0 for PCIe adressing (bus,device)
>>>
>>> No, the bus number is not included in the unit address, so just the
>>> device number (0) is correct here (when the function is 0) IIUC.
>>
>> Some DTs definitely have that, but I couldn't find any documentation to
>> back the syntax up or explain it properly
> 
> It's part of the spec:
> 
> 	http://www.devicetree.org/open-firmware/bindings/pci/pci2_1.pdf
> 
> The first number is the device number and the second is the function
> which can be left out if zero.

OK thank you for clarifying

Konrad