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Date: Mon, 22 Apr 2024 13:40:00 -0700 (PDT)
From: matthew.gerlach@linux.intel.com
To: Rob Herring <robh@kernel.org>
cc: bhelgaas@google.com, lpieralisi@kernel.org, kw@linux.com, 
    krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, 
    linux-pci@vger.kernel.org, devicetree@vger.kernel.org, 
    linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4] dt-bindings: PCI: altera: Convert to YAML
In-Reply-To: <20240422145855.GA1242711-robh@kernel.org>
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References: <20240420145342.118643-1-matthew.gerlach@linux.intel.com> <20240422145855.GA1242711-robh@kernel.org>
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On Mon, 22 Apr 2024, Rob Herring wrote:

> On Sat, Apr 20, 2024 at 09:53:42AM -0500, matthew.gerlach@linux.intel.com wrote:
>> From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>>
>> Convert the device tree bindings for the Altera Root Port PCIe controller
>> from text to YAML.
>>
>> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>> ---
>> v4:
>>  - reorder reg-names to match original binding
>>  - move reg and reg-names to top level with limits.
>>
>> v3:
>>  - Added years to copyright
>>  - Correct order in file of allOf and unevaluatedProperties
>>  - remove items: in compatible field
>>  - fix reg and reg-names constraints
>>  - replace deprecated pci-bus.yaml with pci-host-bridge.yaml
>>  - fix entries in ranges property
>>  - remove device_type from required
>>
>> v2:
>>  - Move allOf: to bottom of file, just like example-schema is showing
>>  - add constraint for reg and reg-names
>>  - remove unneeded device_type
>>  - drop #address-cells and #size-cells
>>  - change minItems to maxItems for interrupts:
>>  - change msi-parent to just "msi-parent: true"
>>  - cleaned up required:
>>  - make subject consistent with other commits coverting to YAML
>>  - s/overt/onvert/g
>> ---
>>  .../devicetree/bindings/pci/altera-pcie.txt   | 50 -----------
>>  .../bindings/pci/altr,pcie-root-port.yaml     | 88 +++++++++++++++++++
>>  2 files changed, 88 insertions(+), 50 deletions(-)
>>  delete mode 100644 Documentation/devicetree/bindings/pci/altera-pcie.txt
>>  create mode 100644 Documentation/devicetree/bindings/pci/altr,pcie-root-port.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/pci/altera-pcie.txt b/Documentation/devicetree/bindings/pci/altera-pcie.txt
>> deleted file mode 100644
>> index 816b244a221e..000000000000
>> --- a/Documentation/devicetree/bindings/pci/altera-pcie.txt
>> +++ /dev/null
>> @@ -1,50 +0,0 @@
>> -* Altera PCIe controller
>> -
>> -Required properties:
>> -- compatible :	should contain "altr,pcie-root-port-1.0" or "altr,pcie-root-port-2.0"
>> -- reg:		a list of physical base address and length for TXS and CRA.
>> -		For "altr,pcie-root-port-2.0", additional HIP base address and length.
>> -- reg-names:	must include the following entries:
>> -		"Txs": TX slave port region
>> -		"Cra": Control register access region
>> -		"Hip": Hard IP region (if "altr,pcie-root-port-2.0")
>> -- interrupts:	specifies the interrupt source of the parent interrupt
>> -		controller.  The format of the interrupt specifier depends
>> -		on the parent interrupt controller.
>> -- device_type:	must be "pci"
>> -- #address-cells:	set to <3>
>> -- #size-cells:		set to <2>
>> -- #interrupt-cells:	set to <1>
>> -- ranges:	describes the translation of addresses for root ports and
>> -		standard PCI regions.
>> -- interrupt-map-mask and interrupt-map: standard PCI properties to define the
>> -		mapping of the PCIe interface to interrupt numbers.
>> -
>> -Optional properties:
>> -- msi-parent:	Link to the hardware entity that serves as the MSI controller
>> -		for this PCIe controller.
>> -- bus-range:	PCI bus numbers covered
>> -
>> -Example
>> -	pcie_0: pcie@c00000000 {
>> -		compatible = "altr,pcie-root-port-1.0";
>> -		reg = <0xc0000000 0x20000000>,
>> -			<0xff220000 0x00004000>;
>> -		reg-names = "Txs", "Cra";
>> -		interrupt-parent = <&hps_0_arm_gic_0>;
>> -		interrupts = <0 40 4>;
>> -		interrupt-controller;
>
> What happened to this? It is clearly needed since the interrupt-map
> below points back to this node. Note that that didn't work at one point
> in time, but I think we fixed it.

I think the DTs I was using test were created during the point in time 
when this did not work. The interrupt-controller boolean and 
#interrupt-cells property were in a sub node, and the interrupt-map 
pointed to the sub-node. Keeping everything in the base node maintains 
compatiblity. I will fix this for v5.

>
> It doesn't seem you are testing the binding against an actual DT.
> Please do that.

I need to fix the DTs I'm using for test :)

Thanks for the feedback,

Matthew Gerlach

>
> Rob
>
>> -		#interrupt-cells = <1>;
>> -		bus-range = <0x0 0xFF>;
>> -		device_type = "pci";
>> -		msi-parent = <&msi_to_gic_gen_0>;
>> -		#address-cells = <3>;
>> -		#size-cells = <2>;
>> -		interrupt-map-mask = <0 0 0 7>;
>> -		interrupt-map = <0 0 0 1 &pcie_0 1>,
>> -			            <0 0 0 2 &pcie_0 2>,
>> -			            <0 0 0 3 &pcie_0 3>,
>> -			            <0 0 0 4 &pcie_0 4>;
>> -		ranges = <0x82000000 0x00000000 0x00000000 0xc0000000 0x00000000 0x10000000
>> -			  0x82000000 0x00000000 0x10000000 0xd0000000 0x00000000 0x10000000>;
>> -	};
>