Subject: Re: [PATCH net-next v2 1/4] dt-bindings: net: add IPA iommus property

From: Bjorn Andersson <[email-masked]>
Date: Mon, 4 May 2020 11:30:10 -0700

On Mon 04 May 10:58 PDT 2020, Alex Elder wrote:

> The IPA accesses "IMEM" and main system memory through an SMMU, so
> its DT node requires an iommus property to define range of stream IDs
> it uses.
> 
> Signed-off-by: Alex Elder <[email-masked]>
> ---
>  Documentation/devicetree/bindings/net/qcom,ipa.yaml | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/qcom,ipa.yaml b/Documentation/devicetree/bindings/net/qcom,ipa.yaml
> index 140f15245654..7b749fc04c32 100644
> --- a/Documentation/devicetree/bindings/net/qcom,ipa.yaml
> +++ b/Documentation/devicetree/bindings/net/qcom,ipa.yaml
> @@ -20,7 +20,10 @@ description:
>    The GSI is an integral part of the IPA, but it is logically isolated
>    and has a distinct interrupt and a separately-defined address space.
>  
> -  See also soc/qcom/qcom,smp2p.txt and interconnect/interconnect.txt.
> +  See also soc/qcom/qcom,smp2p.txt and interconnect/interconnect.txt.  See
> +  iommu/iommu.txt and iommu/arm,smmu.yaml for more information about SMMU
> +  bindings.
> +
>  
>    - |
>      --------             ---------
> @@ -54,6 +57,9 @@ properties:
>        - const: ipa-shared
>        - const: gsi
>  
> +  iommus:
> +    maxItems: 1
> +
>    clocks:
>      maxItems: 1
>  
> @@ -126,6 +132,7 @@ properties:
>  
>  required:
>    - compatible
> +  - iommus

This technically "breaks" backwards compatibility, but the binding is
rather new and in limited use, so I think we should do this.

Reviewed-by: Bjorn Andersson <[email-masked]>

Regards,
Bjorn

>    - reg
>    - clocks
>    - interrupts
> @@ -164,6 +171,7 @@ examples:
>                  modem-init;
>                  modem-remoteproc = <&mss_pil>;
>  
> +                iommus = <&apps_smmu 0x720 0x3>;
>                  reg = <0 0x1e40000 0 0x7000>,
>                          <0 0x1e47000 0 0x2000>,
>                          <0 0x1e04000 0 0x2c000>;
> -- 
> 2.20.1
>