Re: [PATCH v2 1/3] dt-bindings: ath10k: Add wifi-firmware subnode for wifi node

[Rob Herring]

On Wed, Mar 25, 2020 at 04:31:38PM +0530, Rakesh Pillai wrote:
> Add a wifi-firmware subnode for the wifi node.
> This wifi-firmware subnode is needed for the
> targets which do not support TrustZone.
> 
> Signed-off-by: Rakesh Pillai <pillair@xxxxxxxxxxxxxx>
> ---
>  .../devicetree/bindings/net/wireless/qcom,ath10k.txt       | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/net/wireless/qcom,ath10k.txt b/Documentation/devicetree/bindings/net/wireless/qcom,ath10k.txt
> index 71bf91f..65ee68e 100644
> --- a/Documentation/devicetree/bindings/net/wireless/qcom,ath10k.txt
> +++ b/Documentation/devicetree/bindings/net/wireless/qcom,ath10k.txt
> @@ -96,6 +96,17 @@ Optional properties:
>  - qcom,coexist-gpio-pin : gpio pin number  information to support coex
>  			  which will be used by wifi firmware.
>  
> +* Subnodes
> +The ath10k wifi node can contain one optional firmware subnode.
> +Firmware subnode is needed when the platform does not have TustZone.
> +The firmware subnode must have:
> +
> +- iommus:
> +	Usage: required
> +	Value type: <prop-encoded-array>
> +	Definition: A list of phandle and IOMMU specifier pairs.
> +
> +
>  Example (to supply PCI based wifi block details):
>  
>  In this example, the node is defined as child node of the PCI controller.
> @@ -196,4 +207,7 @@ wifi@18000000 {
>  		memory-region = <&wifi_msa_mem>;
>  		iommus = <&apps_smmu 0x0040 0x1>;
>  		qcom,msa-fixed-perm;
> +		wifi-firmware {
> +			iommus = <&apps_iommu 0xc22 0x1>;

Why can't you just add a 2nd entry to the existing 'iommus' property? 

A driver doing of_dma_configure() is generally not the right thing to 
do.

Rob