Re: [PATCH net-next 1/5] dt-bindings: net: qcom,ipa: deprecate modem-init

[Krzysztof Kozlowski]

On 12/11/2022 21:07, Alex Elder wrote:
> GSI firmware for IPA must be loaded during initialization, either by
> the AP or by the modem.  The loader is currently specified based on
> whether the Boolean modem-init property is present.
> 
> Instead, use a new property with an enumerated value to indicate
> explicitly how GSI firmware gets loaded.  With this in place, a
> third approach can be added in an upcoming patch.
> 
> The new qcom,gsi-loader property has two defined values:
>   - self:   The AP loads GSI firmware
>   - modem:  The modem loads GSI firmware
> The modem-init property must still be supported, but is now marked
> deprecated.
> 
> Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
> ---
>  .../devicetree/bindings/net/qcom,ipa.yaml     | 59 +++++++++++++++----
>  1 file changed, 46 insertions(+), 13 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/qcom,ipa.yaml b/Documentation/devicetree/bindings/net/qcom,ipa.yaml
> index e752b76192df0..0dfd6c721e045 100644
> --- a/Documentation/devicetree/bindings/net/qcom,ipa.yaml
> +++ b/Documentation/devicetree/bindings/net/qcom,ipa.yaml
> @@ -124,12 +124,22 @@ properties:
>        - const: ipa-clock-enabled-valid
>        - const: ipa-clock-enabled
>  
> +  qcom,gsi-loader:
> +    enum:
> +      - self
> +      - modem
> +    description:
> +      This indicates how GSI firmware should be loaded.  If the AP loads

s/This indicates/Indicate/
(or any other grammar without describing DT syntax but hardware/system)

> +      and validates GSI firmware, this property has value "self".  If the
> +      modem does this, this property has value "modem".
> +
>    modem-init:
> +    deprecated: true
>      type: boolean
>      description:
> -      If present, it indicates that the modem is responsible for
> -      performing early IPA initialization, including loading and
> -      validating firwmare used by the GSI.
> +      This is the older (deprecated) way of indicating how GSI firmware
> +      should be loaded.  If present, the modem loads GSI firmware; if
> +      absent, the AP loads GSI firmware.
>  
>    memory-region:
>      maxItems: 1
> @@ -155,15 +165,36 @@ required:
>    - interconnects
>    - qcom,smem-states
>  
> -# If modem-init is not present, the AP loads GSI firmware, and
> -# memory-region must be specified
> -if:
> -  not:
> -    required:
> -      - modem-init
> -then:
> -  required:
> -    - memory-region
> +allOf:
> +  # If qcom,gsi-loader is present, modem-init must not be present
> +  - if:
> +      required:
> +        - qcom,gsi-loader
> +    then:
> +      properties:
> +        modem-init: false

This is ok, but will not allow you to keep deprecated property in DTS
for the transition period. We talked about this that you need to keep
both or wait few cycles before applying DTS cleanups.

> +
> +      # If qcom,gsi-loader is "self", the AP loads GSI firmware, and
> +      # memory-region must be specified
> +      if:
> +        properties:
> +          qcom,gsi-loader:
> +            contains:
> +              const: self
> +      then:
> +        required:
> +          - memory-region
> +    else:
> +      # If qcom,gsi-loader is not present, we use deprecated behavior.
> +      # If modem-init is not present, the AP loads GSI firmware, and
> +      # memory-region must be specified.
> +      if:
> +        not:
> +          required:
> +            - modem-init
> +      then:
> +        required:
> +          - memory-region
>  
>  additionalProperties: false
>  
> @@ -196,7 +227,9 @@ examples:
>          ipa@1e40000 {
>                  compatible = "qcom,sdm845-ipa";
>  
> -                modem-init;
> +                qcom,gsi-loader = "self";
> +                memory-region = <&ipa_fw_mem>;
> +                firmware-name = "qcom/sc7180-trogdor/modem-nolte/mba.mbn";

Isn't this example based on sdm845?

>  
>                  iommus = <&apps_smmu 0x720 0x3>;
>                  reg = <0x1e40000 0x7000>,

Best regards,
Krzysztof