Re: [PATCH v3 2/3] dt-bindings: soc: qcom: apr: Add protection domain bindings

[Sibi Sankar]

Hey Rob,
Thanks for the review!

On 1/31/20 8:04 PM, Rob Herring wrote:
> On Mon, Dec 30, 2019 at 10:30:07AM +0530, Sibi Sankar wrote:
> > Add optional "qcom,protection-domain" bindings for APR services. This
> > helps to capture the dependencies between APR services and the PD on
> > which each apr service run.
>
> This is meaningless to me...

Qualcomm SoCs (starting with MSM8998) allow for multiple protection
domains (PDs) to run on the same Q6 sub-system. This allows for
services like AVS AUDIO to have their own separate address space and
crash/recover without disrupting the other PDs running on the same Q6
ADSP. Add "qcom,protection-domain" bindings to capture the dependencies
between the APR service and the PD on which the apr service runs.

Is ^^ better?

> > Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> > Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> > Signed-off-by: Sibi Sankar <sibis@xxxxxxxxxxxxxx>
> > ---
> >   .../devicetree/bindings/soc/qcom/qcom,apr.txt | 59 +++++++++++++++++++
> >   1 file changed, 59 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,apr.txt b/Documentation/devicetree/bindings/soc/qcom/qcom,apr.txt
> > index db501269f47b8..f87c0b2a48de4 100644
> > --- a/Documentation/devicetree/bindings/soc/qcom/qcom,apr.txt
> > +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,apr.txt
> > @@ -45,6 +45,12 @@ by the individual bindings for the specific service
> >   			12 - Ultrasound stream manager.
> >   			13 - Listen stream manager.
> >   
> > +- qcom,protection-domain
> > +	Usage: optional
> > +	Value type: <stringlist>
> > +	Definition: Must list the protection domain service name and path
> > +		    that the particular apr service has a dependency on.
>
> How many strings can there be and can you enumerate the possible
> strings?

https://lore.kernel.org/lkml/a19623d4-ab33-d87e-5925-d0411d7479dd@xxxxxxxxxxxxxx/

Like I explained in ^^ avs/audio is the only service
that the apr device depends on and is known to run only
in "msm/adsp/audio_pd" service path.

However there are other service:service_path pairs
which will get documented when I add support for more
clients like fastrpc and ath10k.

> > +
> >   = EXAMPLE
> >   The following example represents a QDSP based sound card on a MSM8996 device
> >   which uses apr as communication between Apps and QDSP.
> > @@ -82,3 +88,56 @@ which uses apr as communication between Apps and QDSP.
> >   			...
> >   		};
> >   	};
> > +
> > += EXAMPLE 2
> > +The following example represents a QDSP based sound card on SDM845 device.
> > +Here the apr services are dependent on "avs/audio" service running on AUDIO
> > +Protection Domain hosted on ADSP remote processor.
> > +
> > +	apr {
> > +		compatible = "qcom,apr-v2";
> > +		qcom,glink-channels = "apr_audio_svc";
> > +		qcom,apr-domain = <APR_DOMAIN_ADSP>;
> > +
> > +		q6core {
> > +			compatible = "qcom,q6core";
> > +			reg = <APR_SVC_ADSP_CORE>;
> > +			qcom,protection-domain = "avs/audio", "msm/adsp/audio_pd";
> > +		};
> > +
> > +		q6afe: q6afe {
> > +			compatible = "qcom,q6afe";
> > +			reg = <APR_SVC_AFE>;
> > +			qcom,protection-domain = "avs/audio", "msm/adsp/audio_pd";
> > +			q6afedai: dais {
> > +				compatible = "qcom,q6afe-dais";
> > +				#sound-dai-cells = <1>;
> > +
> > +				qi2s@22 {
> > +					reg = <22>;
> > +					qcom,sd-lines = <3>;
> > +				};
> > +			};
> > +		};
> > +
> > +		q6asm: q6asm {
> > +			compatible = "qcom,q6asm";
> > +			reg = <APR_SVC_ASM>;
> > +			qcom,protection-domain = "avs/audio", "msm/adsp/audio_pd";
> > +			q6asmdai: dais {
> > +				compatible = "qcom,q6asm-dais";
> > +				#sound-dai-cells = <1>;
> > +				iommus = <&apps_smmu 0x1821 0x0>;
> > +			};
> > +		};
> > +
> > +		q6adm: q6adm {
> > +			compatible = "qcom,q6adm";
> > +			reg = <APR_SVC_ADM>;
> > +			qcom,protection-domain = "avs/audio", "msm/adsp/audio_pd";
>
> Perhaps an example where not everything is the same. The example shows
> me this isn't needed in DT.

yes will update the example.

> > +			q6routing: routing {
> > +				compatible = "qcom,q6adm-routing";
> > +				#sound-dai-cells = <0>;
> > +			};
> > +		};
> > +	};
> > --
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> > a Linux Foundation Collaborative Project

--
Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc, is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project