Re: [PATCH v5 2/7] dt-bindings: PCI: ti,am65: Extend for use with PVU

[Krzysztof Kozlowski]

On Sun, Sep 08, 2024 at 07:32:28PM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> 
> 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 optional unless the PVU shall be used for PCIe.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
> ---
> CC: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
> CC: "Krzysztof Wilczyński" <kw@xxxxxxxxx>
> CC: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> CC: linux-pci@xxxxxxxxxxxxxxx
> ---
>  .../bindings/pci/ti,am65-pci-host.yaml        | 29 +++++++++++++++++--
>  1 file changed, 26 insertions(+), 3 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..0c297d12173c 100644
> --- a/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
> +++ b/Documentation/devicetree/bindings/pci/ti,am65-pci-host.yaml
> @@ -20,14 +20,18 @@ properties:
>        - ti,keystone-pcie
>  
>    reg:
> -    maxItems: 4
> +    minItems: 4
> +    maxItems: 6
>  
>    reg-names:
> +    minItems: 4
>      items:
>        - const: app
>        - const: dbics
>        - const: config
>        - const: atu
> +      - const: vmap_lp
> +      - const: vmap_hp
>  
>    interrupts:
>      maxItems: 1
> @@ -83,13 +87,30 @@ if:
>      compatible:
>        enum:
>          - ti,am654-pcie-rc
> +
>  then:
> +  properties:
> +    memory-region:

I think I said it two times already. You must define properties in
top-level. That's how we expect, that's how dtschema works (even if it
works fine otherwise, it's not always that case), that's how almost all
bindings are written.

> +      maxItems: 1
> +      description: |
> +        phandle to a restricted DMA pool to be used for all devices behind
> +        this controller. The regions should be defined according to
> +        reserved-memory/shared-dma-pool.yaml.

Best regards,
Krzysztof