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Date:   Fri, 9 Dec 2022 10:14:43 +0100
From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc:     Xiangsheng Hou <xiangsheng.hou@mediatek.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Chuanhong Guo <gch981213@gmail.com>,
        linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-spi@vger.kernel.org, benliang.zhao@mediatek.com,
        bin.zhang@mediatek.com
Subject: Re: [PATCH v3 7/9] dt-bindings: mtd: Split ECC engine with rawnand
 controller
Message-ID: <20221209101443.77fbbe49@xps-13>
In-Reply-To: <f3e3a3d0-6d21-c782-38a2-c8b2c36242c3@linaro.org>
References: <20221208062955.2546-1-xiangsheng.hou@mediatek.com>
        <20221208062955.2546-8-xiangsheng.hou@mediatek.com>
        <fe70d964-229a-8bda-a414-e009dd955e5e@linaro.org>
        <20221208110035.5649a051@xps-13>
        <f3e3a3d0-6d21-c782-38a2-c8b2c36242c3@linaro.org>
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Hi Krzysztof,

krzysztof.kozlowski@linaro.org wrote on Thu, 8 Dec 2022 11:27:27 +0100:

> On 08/12/2022 11:00, Miquel Raynal wrote:
> > Hi Krzysztof,
> >=20
> > krzysztof.kozlowski@linaro.org wrote on Thu, 8 Dec 2022 10:44:17 +0100:
> >  =20
> >> On 08/12/2022 07:29, Xiangsheng Hou wrote: =20
> >>> Split MediaTek ECC engine with rawnand controller and convert to
> >>> YAML schema.
> >>>
> >>> Signed-off-by: Xiangsheng Hou <xiangsheng.hou@mediatek.com>
> >>> ---
> >>>  .../bindings/mtd/mediatek,mtk-nfc.yaml        | 154 +++++++++++++++
> >>>  .../mtd/mediatek,nand-ecc-engine.yaml         |  62 ++++++
> >>>  .../devicetree/bindings/mtd/mtk-nand.txt      | 176 ----------------=
--
> >>>  3 files changed, 216 insertions(+), 176 deletions(-)
> >>>  create mode 100644 Documentation/devicetree/bindings/mtd/mediatek,mt=
k-nfc.yaml
> >>>  create mode 100644 Documentation/devicetree/bindings/mtd/mediatek,na=
nd-ecc-engine.yaml
> >>>  delete mode 100644 Documentation/devicetree/bindings/mtd/mtk-nand.txt
> >>>
> >>> diff --git a/Documentation/devicetree/bindings/mtd/mediatek,mtk-nfc.y=
aml b/Documentation/devicetree/bindings/mtd/mediatek,mtk-nfc.yaml
> >>> new file mode 100644
> >>> index 000000000000..eb1a44c7ae4e
> >>> --- /dev/null
> >>> +++ b/Documentation/devicetree/bindings/mtd/mediatek,mtk-nfc.yaml
> >>> @@ -0,0 +1,154 @@
> >>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> >>> +%YAML 1.2
> >>> +---
> >>> +$id: http://devicetree.org/schemas/mtd/mediatek,mtk-nfc.yaml#
> >>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> >>> +
> >>> +title: MediaTek(MTK) SoCs raw NAND FLASH controller (NFC)
> >>> +
> >>> +maintainers:
> >>> +  - Xiangsheng Hou <xiangsheng.hou@mediatek.com>
> >>> +
> >>> +properties:
> >>> +  compatible:
> >>> +    enum:
> >>> +      - mediatek,mt2701-nfc
> >>> +      - mediatek,mt2712-nfc
> >>> +      - mediatek,mt7622-nfc
> >>> +
> >>> +  reg:
> >>> +    items:
> >>> +      - description: Base physical address and size of NFI.
> >>> +
> >>> +  interrupts:
> >>> +    items:
> >>> +      - description: NFI interrupt
> >>> +
> >>> +  clocks:
> >>> +    items:
> >>> +      - description: clock used for the controller
> >>> +      - description: clock used for the pad
> >>> +
> >>> +  clock-names:
> >>> +    items:
> >>> +      - const: nfi_clk
> >>> +      - const: pad_clk
> >>> +
> >>> +  ecc-engine:
> >>> +    description: device-tree node of the required ECC engine.
> >>> +    $ref: /schemas/types.yaml#/definitions/phandle
> >>> +
> >>> +patternProperties:
> >>> +  "^nand@[a-f0-9]$":
> >>> +    type: object   =20
> >>
> >> This should be instead:
> >>     $ref: nand-chip.yaml#
> >>     unevaluatedProperties: false
> >>
> >> and then properties below (due to current dtschema limitations) should
> >> list properties from nand-controller.yaml:
> >>
> >>       nand-on-flash-bbt: true
> >>
> >> Optionally, we could create additional schema - nand-controller-chip,
> >> which would be referenced directly by nand-controller and itself would
> >> ref nand-chip. =20
> >=20
> > Isn't this enough? (in linux-next)
> > https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git/tree/Docu=
mentation/devicetree/bindings/mtd/nand-controller.yaml?h=3Dmtd/next#n54 =20
>=20
> No, I tested it and it does not work as intended. In this particular
> case. I think this is a limitation of dtschema, because binding itself
> looks fine. The problem is that you have:
> 1. mtk-nfc having nand@ children. mtk-nfc references nand-controller
> which brings these children.
> 2. However nand-controller while bringing these children does two things:
> a. ref: nand-chip
> b. add more propeties
>=20
> 3. The mtk-nfc must further extend the nand@ child.
> 4. If you add "unevaluatedProperties: false" you notice warnings of
> unevaluated propertie from nand-controller children.

Thanks for the details. Any chances this can eventually be fixed at
dt-schema level?

Thanks,
Miqu=C3=A8l