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From: Luca Weiss <luca@z3ntu.xyz>
To: Rob Herring <robh@kernel.org>
Cc: ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org,
 Bjorn Andersson <andersson@kernel.org>,
 Konrad Dybcio <konrad.dybcio@linaro.org>,
 Krzysztof Kozlowski <krzk+dt@kernel.org>, Conor Dooley <conor+dt@kernel.org>,
 Andy Gross <agross@kernel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
 linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
 linux-kernel@vger.kernel.org
Subject:
 Re: [PATCH RFC 1/2] dt-bindings: soc: qcom,smsm: Allow specifying mboxes
 instead of qcom,ipc
Date: Wed, 15 May 2024 17:06:33 +0200
Message-ID: <2729475.mvXUDI8C0e@g550jk>
In-Reply-To: <5087455.31r3eYUQgx@g550jk>
References:
 <20240424-smsm-mbox-v1-0-555f3f442841@z3ntu.xyz>
 <20240425161715.GA2759240-robh@kernel.org> <5087455.31r3eYUQgx@g550jk>
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Hi Rob,

Any feedback on the below topic?

Regards
Luca

On Donnerstag, 25. April 2024 20:54:40 MESZ Luca Weiss wrote:
> On Donnerstag, 25. April 2024 18:17:15 MESZ Rob Herring wrote:
> > On Wed, Apr 24, 2024 at 07:21:51PM +0200, Luca Weiss wrote:
> > > The qcom,ipc-N properties are essentially providing a reference to a
> > > mailbox, so allow using the mboxes property to do the same in a more
> > > structured way.
> > 
> > Can we mark qcom,ipc-N as deprecated then?
> 
> Yes, that should be ok. Will also send a similar change to the other bindings
> that support both qcom,ipc and mboxes.
> 
> >  
> > > Since multiple SMSM hosts are supported, we need to be able to provide
> > > the correct mailbox for each host. The old qcom,ipc-N properties map to
> > > the mboxes property by index, starting at 0 since that's a valid SMSM
> > > host also.
> > > 
> > > The new example shows how an smsm node with just qcom,ipc-3 should be
> > > specified with the mboxes property.
> > > 
> > > Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
> > > ---
> > >  .../devicetree/bindings/soc/qcom/qcom,smsm.yaml    | 48 ++++++++++++++++++----
> > >  1 file changed, 40 insertions(+), 8 deletions(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> > > index db67cf043256..b12589171169 100644
> > > --- a/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> > > +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,smsm.yaml
> > > @@ -33,6 +33,13 @@ properties:
> > >        specifier of the column in the subscription matrix representing the local
> > >        processor.
> > >  
> > > +  mboxes:
> > > +    minItems: 1
> > > +    maxItems: 5
> > 
> > Need to define what each entry is.
> 
> The entry is (description from qcom,ipc-N)
> 
>   "the outgoing ipc bit used for signaling the N:th remote processor."
> 
> So you want me to add 5 times e.g.
> 
> - the IPC mailbox used for signaling the 0th remote processor
> - the IPC mailbox used for signaling the 1st remote processor
> 
> etc? I don't really have any extra knowledge on smsm to be able to write
> something better there..
> 
> Also what are your thoughts on this binding vs the alternative I wrote
> in the cover letter? I'm not really happy about how the properties are
> represented.
> 
> Regards
> Luca
> 
> 
> > 
> > > +    description:
> > > +      Reference to the mailbox representing the outgoing doorbell in APCS for
> > > +      this client.
> > > +
> > >    '#size-cells':
> > >      const: 0
> > >  
> > > @@ -98,15 +105,18 @@ required:
> > >    - '#address-cells'
> > >    - '#size-cells'
> > >  
> > > -anyOf:
> > > +oneOf:
> > >    - required:
> > > -      - qcom,ipc-1
> > > -  - required:
> > > -      - qcom,ipc-2
> > > -  - required:
> > > -      - qcom,ipc-3
> > > -  - required:
> > > -      - qcom,ipc-4
> > > +      - mboxes
> > > +  - anyOf:
> > > +      - required:
> > > +          - qcom,ipc-1
> > > +      - required:
> > > +          - qcom,ipc-2
> > > +      - required:
> > > +          - qcom,ipc-3
> > > +      - required:
> > > +          - qcom,ipc-4
> > >  
> > >  additionalProperties: false
> > >  
> > > @@ -136,3 +146,25 @@ examples:
> > >              #interrupt-cells = <2>;
> > >          };
> > >      };
> > > +  # Example using mboxes property
> > > +  - |
> > > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > > +
> > > +    shared-memory {
> > > +        compatible = "qcom,smsm";
> > > +        #address-cells = <1>;
> > > +        #size-cells = <0>;
> > > +        mboxes = <0>, <0>, <0>, <&apcs 19>;
> > > +
> > > +        apps@0 {
> > > +            reg = <0>;
> > > +            #qcom,smem-state-cells = <1>;
> > > +        };
> > > +
> > > +        wcnss@7 {
> > > +            reg = <7>;
> > > +            interrupts = <GIC_SPI 144 IRQ_TYPE_EDGE_RISING>;
> > > +            interrupt-controller;
> > > +            #interrupt-cells = <2>;
> > > +        };
> > > +    };
> > > 
> > 
> 
>