Re: [PATCH 1/3] dt-bindings: spi: Add realtek,rtl9300-snand

[Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>]

On 8/10/24 08:58, Chris Packham wrote:
> On 7/10/24 19:40, Krzysztof Kozlowski wrote:
> > On Mon, Oct 07, 2024 at 12:33:45PM +1300, Chris Packham wrote:
> > > Add a dtschema for the SPI-NAND controller on the RTL9300 SoCs. The
> > > controller supports
> > >   * Serial/Dual/Quad data with
> > >   * PIO and DMA data read/write operation
> > >   * Configurable flash access timing
> > >
> > > Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> > > ---
> > >   .../bindings/spi/realtek,rtl9300-snand.yaml   | 58 
> > > +++++++++++++++++++
> > >   1 file changed, 58 insertions(+)
> > >   create mode 100644 
> > > Documentation/devicetree/bindings/spi/realtek,rtl9300-snand.yaml
> > >
> > > diff --git 
> > > a/Documentation/devicetree/bindings/spi/realtek,rtl9300-snand.yaml 
> > > b/Documentation/devicetree/bindings/spi/realtek,rtl9300-snand.yaml
> > > new file mode 100644
> > > index 000000000000..c66aea24cb35
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/spi/realtek,rtl9300-snand.yaml
> > > @@ -0,0 +1,58 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/spi/realtek,rtl9300-snand.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: SPI-NAND Flash Controller for Realtek RTL9300 SoCs
> > > +
> > > +maintainers:
> > > +  - Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> > > +
> > > +description:
> > > +  The Realtek RTL9300 SoCs have a built in SPI-NAND controller. It 
> > > supports
> > > +  typical SPI-NAND page cache operations in single, dual or quad IO 
> > > mode.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    items:
> > Why 9300 cannot be alone? What does 9300 mean even? Wildcards and family
> > models are not allowed in general.
>
> The main thing about the RTL9300 is that that is what all the Realtek 
> documents use to refer to these chips and the specific numbers are 
> akin to the manufacturing part number that you'd actually order (maybe 
> that's a bit of a stretch).
>
> The SoC/CPU block probably does exist as a separate silicon die that 
> they connect to the different switch blocks in the chips that they 
> sell but I don't think you can get "just" the SoC. There is every 
> chance that we'll see that same SoC/CPU block pop up in new chips (I 
> see references to a RTL9302D in some documents). I'd like to be able 
> to support these chips using "rtl9300" but if that's violating the 
> wildcard rule I can drop it.
Maybe it's helpful to think of the RTL9300 as the IP block that is 
integrated into the RTL9301, RTL9302B, etc.

> > > +      - enum:
> > > +          - realtek,rtl9301-snand
> > > +          - realtek,rtl9302b-snand
> > > +          - realtek,rtl9302c-snand
> > > +          - realtek,rtl9303-snand
> > > +      - const: realtek,rtl9300-snand
> > > +
> > > +  reg:
> > > +    items:
> > > +      - description: SPI NAND controller registers address and size
> > Also: why no clocks? Binding is supposed to be complete. If it cannot,
> > you should explain it in the commit msg.
>
> I didn't add it because I had no need for it in my driver. But as 
> you've said previously the binding shouldn't care what the driver does.
>
> I do have the clocking info from the datasheets. I'll add it in v2.
>
> > Best regards,
> > Krzysztof