Hi, keguang.zhang@xxxxxxxxx wrote on Sat, 18 May 2024 16:01:01 +0800: > On Mon, May 6, 2024 at 3:14 PM Miquel Raynal <miquel.raynal@xxxxxxxxxxx> wrote: > > > > Hello, > > > > devnull+keguang.zhang.gmail.com@xxxxxxxxxx wrote on Tue, 30 Apr 2024 > > 19:11:10 +0800: > > > > > From: Keguang Zhang <keguang.zhang@xxxxxxxxx> > > > > > > Add devicetree binding document for Loongson-1 NAND Controller. > > > > > > Signed-off-by: Keguang Zhang <keguang.zhang@xxxxxxxxx> > > > --- > > > Changes in v7: > > > - rename the file to loongson,ls1b-nfc.yaml > > > > > > Changes in v6: > > > - A newly added patch > > > --- > > > .../devicetree/bindings/mtd/loongson,ls1b-nfc.yaml | 66 ++++++++++++++++++++++ > > > 1 file changed, 66 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/mtd/loongson,ls1b-nfc.yaml b/Documentation/devicetree/bindings/mtd/loongson,ls1b-nfc.yaml > > > new file mode 100644 > > > index 000000000000..a69f22b9fd9e > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/mtd/loongson,ls1b-nfc.yaml > > > @@ -0,0 +1,66 @@ > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > > +%YAML 1.2 > > > +--- > > > +$id: http://devicetree.org/schemas/mtd/loongson,ls1b-nfc.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: Loongson-1 NAND Controller > > > + > > > +maintainers: > > > + - Keguang Zhang <keguang.zhang@xxxxxxxxx> > > > + > > > +allOf: > > > + - $ref: nand-controller.yaml > > > + > > > +properties: > > > + compatible: > > > + oneOf: > > > + - const: loongson,ls1b-nfc > > > > What is the rationale behind this choice? Seems like the b variant has > > two possible implementations and should always be preceded by a more > > specific compatible. > > > > As there is currently no description of this controller upstream, I > > would not care too much about any out-of-tree description and directly > > go for a clean description. > > > Excuse me, should I add a description for this property? No, description is not needed. But you are allowing the "loongson,ls1b-nfc" compatible alone, which I think is not relevant, unless you convince me it is :-) > > > + - items: > > > + - enum: > > > + - loongson,ls1a-nfc > > > + - loongson,ls1c-nfc > > > + - const: loongson,ls1b-nfc > > > + > > > + reg: > > > + maxItems: 1 > > > + > > > + dmas: > > > + maxItems: 1 > > > + > > > + dma-names: > > > + const: rxtx > > > + > > > +patternProperties: > > > + "^nand@[0-3]$": > > > + type: object > > > + $ref: raw-nand-chip.yaml > > > + > > > + unevaluatedProperties: false > > > + > > > +required: > > > + - compatible > > > + - reg > > > + - dmas > > > + - dma-names > > > > Should DMA props be required? > > > Yes. This NAND controller only works with DMA, which means the DMA is necessary. Ok > > > > + > > > +unevaluatedProperties: false > > > + > > > +examples: > > > + - | > > > + nand-controller@1fe78000 { > > > + compatible = "loongson,ls1b-nfc"; > > > + reg = <0x1fe78000 0x40>; > > > + > > > + #address-cells = <1>; > > > + #size-cells = <0>; > > > + > > > + dmas = <&dma 0>; > > > + dma-names = "rxtx"; > > > > There is a preferred spacing for DT nodes, see: > > https://docs.kernel.org/devicetree/bindings/dts-coding-style.html > > > Sorry. I don't get the meaning of preferred spacing. > https://docs.kernel.org/devicetree/bindings/writing-schema.html says > "For DTS examples in the schema, preferred is four-space indentation." > Then I used four-space indentation. I'm talking about the new lines (\n) between the properties. > > > > + > > > + nand@0 { > > > + reg = <0>; > > > + nand-use-soft-ecc-engine; > > > + nand-ecc-algo = "hamming"; > > > > These two properties are not needed. Unless there is no hardware ECC > > capability on this controller and in this case you need to ensure the > > properties are present in the schema. > > Exactly. This NAND controller doesn't support hardware ECC. > 'nand-use-soft-ecc-engine' and 'nand-ecc-algo' are present in nand-chip.yaml. > Is there anything else I should do? Thry are in nand-chip.yaml, which means they are allowed, but I want them mandatory: required: - foo - bar Thanks, Miquèl