Re: [PATCH v5 2/3] dt-bindings: mtd: qcom_nandc: document qcom,boot-partitions binding

From: Ansuel Smith <ansuelsmth@gmail.com>
To: Manivannan Sadhasivam <mani@kernel.org>
Cc: Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	linux-mtd@lists.infradead.org, linux-arm-msm@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 2/3] dt-bindings: mtd: qcom_nandc: document qcom,boot-partitions binding
Date: Thu, 9 Jun 2022 12:25:27 +0200	[thread overview]
Message-ID: <62a1ca9a.1c69fb81.3b355.0b02@mx.google.com> (raw)
In-Reply-To: <20220609072029.GA2758@thinkpad>

On Thu, Jun 09, 2022 at 12:50:29PM +0530, Manivannan Sadhasivam wrote:
> On Wed, Jun 08, 2022 at 02:10:29AM +0200, Ansuel Smith wrote:
> > Document new qcom,boot-partition binding used to apply special
> > read/write layout to boot partitions.
> > 
> > QCOM apply a special layout where spare data is not protected
> > by ECC for some special pages (used for boot partition). Add
> > Documentation on how to declare these special pages.
> > 
> > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> > ---
> >  .../devicetree/bindings/mtd/qcom,nandc.yaml   | 26 +++++++++++++++++++
> >  1 file changed, 26 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml
> > index 84ad7ff30121..a0914ccb95b0 100644
> > --- a/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml
> > +++ b/Documentation/devicetree/bindings/mtd/qcom,nandc.yaml
> > @@ -102,6 +102,30 @@ allOf:
> >              - const: rx
> >              - const: cmd
> >  
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - qcom,ipq806x-nand
> > +
> > +    then:
> > +      properties:
> > +        qcom,boot-partitions:
> > +          $ref: /schemas/types.yaml#/definitions/uint32-matrix
> 
> Wondering if u32 is enough for covering all ranges? Other than this,
> 
> Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
> 
> Thanks,
> Mani
>

I mean they are offset and sizes... Considering it's an old SoC and max
nand mounted is 1g we should be safe with u32.

> > +          items:
> > +            items:
> > +              - description: offset
> > +              - description: size
> > +          description:
> > +            Boot partition use a different layout where the 4 bytes of spare
> > +            data are not protected by ECC. Use this to declare these special
> > +            partitions by defining first the offset and then the size.
> > +
> > +            It's in the form of <offset1 size1 offset2 size2 offset3 ...>
> > +
> > +            Refer to the ipq8064 example on how to use this special binding.
> > +
> >  required:
> >    - compatible
> >    - reg
> > @@ -135,6 +159,8 @@ examples:
> >          nand-ecc-strength = <4>;
> >          nand-bus-width = <8>;
> >  
> > +        qcom,boot-partitions = <0x0 0x58a0000>;
> > +
> >          partitions {
> >            compatible = "fixed-partitions";
> >            #address-cells = <1>;
> > -- 
> > 2.36.1
> > 
> 
> -- 
> மணிவண்ணன் சதாசிவம்

-- 
	Ansuel