Re: [PATCH v5 2/2] dt-bindings: mtd: davinci: convert to yaml

From: Marcus Folkesson
Date: Mon Oct 14 2024 - 08:04:35 EST



Krzysztof,

I'm sorry for all these iterations, it wouldn't have been necessary if I had
done my homework better. I'm not too familiar with writing these and I do
often find the descriptions unclear and not obvious.
Anyway, thank you for your patience, reviews and help.


On Tue, Oct 08, 2024 at 03:28:33PM +0200, Krzysztof Kozlowski wrote:
> On Tue, Oct 08, 2024 at 09:02:45AM +0200, Marcus Folkesson wrote:
> > Convert the bindings to yaml format.
> >
> > Signed-off-by: Marcus Folkesson <marcus.folkesson@xxxxxxxxx>
> > ---
> > .../devicetree/bindings/mtd/davinci-nand.txt | 94 -----------------
> > .../devicetree/bindings/mtd/ti,davinci-nand.yaml | 115 +++++++++++++++++++++
> > 2 files changed, 115 insertions(+), 94 deletions(-)
> >
>
>
> > diff --git a/Documentation/devicetree/bindings/mtd/ti,davinci-nand.yaml b/Documentation/devicetree/bindings/mtd/ti,davinci-nand.yaml
> > new file mode 100644
> > index 0000000000000000000000000000000000000000..1263616593532e8483d556b4242b004a16620ddf
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/ti,davinci-nand.yaml
> > @@ -0,0 +1,115 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/mtd/ti,davinci-nand.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: TI DaVinci NAND controller
> > +
> > +maintainers:
> > + - Marcus Folkesson <marcus.folkesson@xxxxxxxxx>
> > +
> > +allOf:
> > + - $ref: nand-controller.yaml#
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - ti,davinci-nand
> > + - ti,keystone-nand
> > +
> > + reg:
> > + maxItems: 1
>
> This was different in original binding and commit msg does not explain
> changes. Be sure any change from pure conversion is explained in the
> commit msg.

Hm. Another misinterpretation from my side.
Should I use items instead? E.g.

reg:
items:
- description: |
Contains 2 offset/length values:
- offset and length for the access window.
- offset and length for accessing the AEMIF
control registers.

>
> > +
> > + partitions:
> > + $ref: /schemas/mtd/partitions/partitions.yaml
> > +
> > + ti,davinci-chipselect:
> > + description:
> > + Number of chipselect. Indicate on the davinci_nand driver which
> > + chipselect is used for accessing the nand.
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + enum: [0, 1, 2, 3]
> > +
> > + ti,davinci-mask-ale:
> > + description:
> > + Mask for ALE. Needed for executing address phase. These offset will be
> > + added to the base address for the chip select space the NAND Flash
> > + device is connected to.
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + default: 0x08
> > +
> > + ti,davinci-mask-cle:
> > + description:
> > + Mask for CLE. Needed for executing command phase. These offset will be
> > + added to the base address for the chip select space the NAND Flash device
> > + is connected to.
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + default: 0x10
> > +
> > + ti,davinci-mask-chipsel:
> > + description:
> > + Mask for chipselect address. Needed to mask addresses for given
> > + chipselect.
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + default: 0
> > +
> > + ti,davinci-ecc-bits:
> > + description: Used ECC bits.
> > + enum: [1, 4]
> > +
> > + ti,davinci-ecc-mode:
> > + description: Operation mode of the NAND ECC mode.
> > + $ref: /schemas/types.yaml#/definitions/string
> > + enum: [none, soft, hw, on-die]
> > + deprecated: true
> > +
> > + ti,davinci-nand-buswidth:
> > + description: Bus width to the NAND chip
> > + $ref: /schemas/types.yaml#/definitions/uint32
> > + enum: [8, 16]
> > + default: 8
> > + deprecated: true
> > +
> > + ti,davinci-nand-use-bbt:
> > + type: boolean
> > + description:
> > + Use flash based bad block table support. OOB identifier is saved in OOB
> > + area.
> > + deprecated: true
> > +
> > +required:
> > + - compatible
> > + - reg
> > + - ti,davinci-chipselect
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > + - |
> > + nand-controller@2000000 {
> > + compatible = "ti,davinci-nand";
> > + #address-cells = <1>;
> > + #size-cells = <0>;
>
> I did not notice it last time.... but what is this? How could you have
> no sizes?
>
> > +
> > + reg = <0 0x02000000>;
>
> This is odd. Address is not 0... and size should be 0.
>
> I don't get how it even works. For sure it is not correct.

Outch. It slipped through when I was laborating.

This was the example I wanted to get working:


```
examples:
- |
nand-controller@2000000,0 {
compatible = "ti,davinci-nand";
#address-cells = <1>;
#size-cells = <1>;
reg = <0 0x02000000 0x02000000
1 0x00000000 0x00008000>;

ti,davinci-chipselect = <1>;
ti,davinci-mask-ale = <0>;
ti,davinci-mask-cle = <0>;
ti,davinci-mask-chipsel = <0>;

ti,davinci-nand-buswidth = <16>;
ti,davinci-ecc-mode = "hw";
ti,davinci-ecc-bits = <4>;
ti,davinci-nand-use-bbt;

partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;

partition@0 {
label = "u-boot env";
reg = <0 0x020000>;
};
};
};
```


But I'm getting the following errors:

```
.../ti,davinci-nand.example.dtb: nand-controller@2000000,0: #size-cells: 0 was expected
from schema $id: http://devicetree.org/schemas/mtd/ti,davinci-nand.yaml#
.../ti,davinci-nand.example.dtb: nand-controller@2000000,0: reg: [[0, 33554432], [33554432, 1], [0, 32768]] is too long
from schema $id: http://devicetree.org/schemas/mtd/ti,davinci-nand.yaml#
.../ti,davinci-nand.example.dtb: nand-controller@2000000,0: Unevaluated properties are not allowed ('reg' was unexpected)
from schema $id: http://devicetree.org/schemas/mtd/ti,davinci-nand.yaml#
```

The resuling 'ti,davinci-nand.example.dts' contains the following:

```
example-0 {
#address-cells = <1>;
#size-cells = <1>;

nand-controller@2000000,0 {
compatible = "ti,davinci-nand";
#address-cells = <1>;
#size-cells = <1>;
reg = <0 0x02000000 0x02000000
1 0x00000000 0x00008000>;
```


How do I set #address-cells in example-0 to 2?
I guess that is the problem.
>
> Best regards,
> Krzysztof

Thanks,
Marcus

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