Re: [PATCH v6 1/3] dt-bindings: mtd: Add Loongson-1 NAND Controller

[Keguang Zhang <keguang.zhang@xxxxxxxxx>]

On Thu, Mar 28, 2024 at 12:23 AM Conor Dooley <conor@xxxxxxxxxx> wrote:
>
> On Wed, Mar 27, 2024 at 06:43:59PM +0800, Keguang Zhang via B4 Relay wrote:
> > 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 v6:
> > - A newly added patch
> > ---
> >  .../devicetree/bindings/mtd/loongson,ls1x-nfc.yaml | 66 ++++++++++++++++++++++
> >  1 file changed, 66 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/mtd/loongson,ls1x-nfc.yaml b/Documentation/devicetree/bindings/mtd/loongson,ls1x-nfc.yaml
> > new file mode 100644
> > index 000000000000..2494c7b3b506
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/loongson,ls1x-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,ls1x-nfc.yaml#
>
> Please make the filename match the compatible.
>
Got it. I'll rename it to loongson,ls1-nfc.yaml and change the
compatible as follows.
  compatible:
   items:
     - enum:
         - loongson,ls1a-nfc
         - loongson,ls1b-nfc
         - loongson,ls1c-nfc
     - const: loongson,ls1-nfc

> > +$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
> > +      - items:
> > +          - enum:
> > +              - loongson,ls1a-nfc
> > +              - loongson,ls1c-nfc
> > +          - const: loongson,ls1b-nfc
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  dmas:
> > +    maxItems: 1
> > +
> > +  dma-names:
> > +    const: rxtx
>
> If you only have one dma, why do you need a dma-names entry for it?
>
Without "dma-names", the following error will come out when doing
dt_binding_check.
  nand-controller@1fe78000: 'dma-names' is a required property

In addition, loongson1_nand.c calls dma_request_chan(). Then
dma_request_chan() calls of_dma_request_slave_channel(), in which the
'dma-names' is necessary.
struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
                                             const char *name)
{
       ...
       count = of_property_count_strings(np, "dma-names");
       if (count < 0) {
               pr_err("%s: dma-names property of node '%pOF' missing
or empty\n",
                       __func__, np);
               return ERR_PTR(-ENODEV);
       }
       ...
}

Thanks for your review!

> Looks fine to me otherwise though,
> COnor.
>
> > +
> > +patternProperties:
> > +  "^nand@[0-3]$":
> > +    type: object
> > +    $ref: raw-nand-chip.yaml
> > +
> > +    unevaluatedProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - dmas
> > +  - dma-names
> > +
> > +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";
> > +
> > +        nand@0 {
> > +            reg = <0>;
> > +            nand-use-soft-ecc-engine;
> > +            nand-ecc-algo = "hamming";
> > +        };
> > +    };
> >
> > --
> > 2.40.1
> >
> >



--
Best regards,

Keguang Zhang