Re: [PATCH v3 2/7] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Jan Kiszka <jan.kiszka@siemens.com>]

On 29.08.24 08:14, Krzysztof Kozlowski wrote:
> On Wed, Aug 28, 2024 at 08:01:15PM +0200, Jan Kiszka wrote:
>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>
>> The PVU on the AM65 SoC is capable of restricting DMA from PCIe devices
>> to specific regions of host memory. Add the optional property
>> "memory-regions" to point to such regions of memory when PVU is used.
>>
>> Since the PVU deals with system physical addresses, utilizing the PVU
>> with PCIe devices also requires setting up the VMAP registers to map the
>> Requester ID of the PCIe device to the CBA Virtual ID, which in turn is
>> mapped to the system physical address. Hence, describe the VMAP
>> registers which are optionally unless the PVU shall used for PCIe.
>>
>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>> ---
>> CC: Lorenzo Pieralisi <lpieralisi@kernel.org>
>> CC: "Krzysztof Wilczyński" <kw@linux.com>
>> CC: Bjorn Helgaas <bhelgaas@google.com>
>> CC: linux-pci@vger.kernel.org
>> ---
>>  .../bindings/pci/ti,am65-pci-host.yaml        | 52 ++++++++++++++-----
>>  1 file changed, 40 insertions(+), 12 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> index 0a9d10532cc8..d8182bad92de 100644
>> --- a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> +++ b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
>> @@ -19,16 +19,6 @@ properties:
>>        - ti,am654-pcie-rc
>>        - ti,keystone-pcie
>>  
>> -  reg:
>> -    maxItems: 4
>> -
>> -  reg-names:
>> -    items:
>> -      - const: app
>> -      - const: dbics
>> -      - const: config
>> -      - const: atu
>> -
> 
> Properties must be defined in top-level.
> 
> https://elixir.bootlin.com/linux/v6.8/source/Documentation/devicetree/bindings/ufs/qcom,ufs.yaml
> 

Tried that already, moving the else: part to top-level, but dtschema
(2024.5) checks fail then. Could you explain why?

>>    interrupts:
>>      maxItems: 1
>>  
>> @@ -84,12 +74,48 @@ if:
>>        enum:
>>          - ti,am654-pcie-rc
>>  then:
>> +  properties:
>> +    reg:
>> +      minItems: 4
>> +      maxItems: 6
>> +
>> +    reg-names:
>> +      minItems: 4
>> +      items:
>> +        - const: app
>> +        - const: dbics
>> +        - const: config
>> +        - const: atu
>> +        - const: vmap_lp
>> +        - const: vmap_hp
> 
> This as well goes to the top.
> 
>> +
>> +    memory-region:
>> +      minItems: 1
> 
> Missing maxItems and this must be defined in top-level.
> 

As explained (and documented), there is no maximum. And this does not
apply to ti,keystone-pcie because only the AM65 supports the PVU.

Jan

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