Re: [PATCH v5 03/21] dt-bindings: pinctrl: Add starfive,jhb100-sys0-pinctrl

Hi, Krzysztof

Thanks for the feedback.

> On Fri, Aug 14, 2026 at 01:46:03AM +0000, Changhuang Liang wrote:
> > Hi, Rob, Conor, Linus
> >
> > > HI, Rob
> > >
> > > Thanks for the review.
> > >
> > > > On Mon, Aug 10, 2026 at 09:51:07AM +0000, Changhuang Liang wrote:
> > > > > Hi, Rob
> > > > >
> > > > > > On Sun, 09 Aug 2026 23:36:32 -0700, Changhuang Liang wrote:
> > > > > > > Add pinctrl bindings for StarFive JHB100 SoC System-0(sys0)
> > > > > > > pinctrl controller.
> > > > > > >
> > > > > > > Signed-off-by: Changhuang Liang
> > > > > > > <[email protected]>
> > > > > > > ---
> > > > > > >  .../pinctrl/starfive,jhb100-sys0-pinctrl.yaml | 164
> > > > ++++++++++++++++++
> > > > > > >  .../pinctrl/starfive,jhb100-pinctrl.h         |  17 ++
> > > > > > >  2 files changed, 181 insertions(+)  create mode 100644
> > > > > > > Documentation/devicetree/bindings/pinctrl/starfive,jhb100-sy
> > > > > > > s0-p
> > > > > > > in
> > > > > > > ctrl
> > > > > > > .yaml  create mode 100644
> > > > > > > include/dt-bindings/pinctrl/starfive,jhb100-pinctrl.h
> > > > > > >
> > > > > >
> > > > > > My bot found errors running 'make dt_binding_check' on your patch:
> > > > > >
> > > > > > yamllint warnings/errors:
> > > > > >
> > > > > > dtschema/dtc warnings/errors:
> > > > > > Documentation/devicetree/bindings/pinctrl/starfive,jhb100-sys0
> > > > > > -pin
> > > > > > ct
> > > > > > rl.exa
> > > > > > mple.dtb: pinctrl@13080000 (starfive,jhb100-sys0-pinctrl):
> > > > > > gpio-ranges:1: [4] is too short
> > > > > > 	from schema $id:
> http://devicetree.org/schemas/gpio/gpio.yaml
> > > > > >
> > > > > > doc reference errors (make refcheckdocs):
> > > > > >
> > > > > > See
> > > > > > https://patchwork.kernel.org/project/devicetree/patch/20260810
> > > > > > 0636
> > > > > > 50
> > > > > > .23 [email protected]
> > > > > >
> > > > > > The base for the series is generally the latest rc1. A
> > > > > > different dependency should be noted in *this* patch.
> > > > > >
> > > > > > If you already ran 'make dt_binding_check' and didn't see the
> > > > > > above error(s), then make sure 'yamllint' is installed and
> > > > > > dt-schema is up to
> > > > > > date:
> > > > > >
> > > > > > pip3 install dtschema --upgrade
> > > > > >
> > > > > > Please check and re-submit after running the above command
> yourself.
> > > > > > Note that DT_SCHEMA_FILES can be set to your schema file to
> > > > > > speed up checking your schema. However, it must be unset to
> > > > > > test all examples with your schema.
> > > > >
> > > > > Hi Rob,
> > > > >
> > > > > Regarding this link:
> > > > >
> > > >
> > >
> https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schem
> > > a
> > > > s
> > > > > /gpio/gpio.yaml#L71
> > > > >
> > > > > It seems that the configuration to support #gpio-cells = <3>;
> > > > > has not been
> > > > added here yet, is that correct?
> > > >
> > > > Shrug. Based on the description, gpio-ranges doesn't depend the # of
> cells.
> > > >
> > > > Why do you need 3 cells? You haven't described the cell content.
> > >
> > > For the pinctrl of JHB100, every 32 GPIOs correspond to one
> > > register, so it uses 3-cell #gpio-cells and 4-cell gpio-ranges, which helps
> simplify the driver code.
> > >
> > > I referred to this generic implementation:
> > > https://elixir.bootlin.com/linux/v7.2-rc6/source/drivers/gpio/gpioli
> > > b-of.c#L93
> > > 6
> > >
> > > So the content of gpio cells and gpio-ranges is as follows:
> > > gpios = <&gpio [instance] offset flags>; gpio-ranges = <&pinctrl
> > > [gpio_instance] gpio_offset pin_offset count>;
> > >
> > > I'm not sure whether this error is caused by a mismatch with the
> > > definition in
> > > schemas/gpio/gpio.yaml:
> > >
> > > gpio-ranges:
> > >   $ref: /schemas/types.yaml#/definitions/phandle-array
> > >   items:
> > >     items:
> > >       - description: pin controller phandle
> > >       - description: GPIO controller offset
> > >       - description: pin controller offset
> > >       - description: number of pins
> > >
> > > Do you have any suggestions for fixing this? Thank you very much.
> > >
> > > Best Regards,
> > > Changhuang
> >
> > For these configurations:
> > gpios = <&gpio [instance] offset flags>; gpio-ranges = <&pinctrl
> > [gpio_instance] gpio_offset pin_offset count>;
> >
> > I tried using spacemit,k1-gpio for comparison. Currently, the gpio-ranges
> configuration under K1 is as follows, and it does not report any errors:
> >
> > gpio: gpio@d4019000 {
> >     compatible = "spacemit,k1-gpio";
> >     gpio-ranges = <&pinctrl 0 0 0 32>,
> >                   <&pinctrl 1 0 32 32>,
> >                   <&pinctrl 2 0 64 32>,
> >                   <&pinctrl 3 0 96 32>; };
> >
> > Then I reduced it by removing one set of entries, changing it to:
> >
> > gpio: gpio@d4019000 {
> >     compatible = "spacemit,k1-gpio";
> >     gpio-ranges = <&pinctrl 0 0 0 32>,
> >                   <&pinctrl 1 0 32 32>,
> >                   <&pinctrl 2 0 64 32>; };
> >
> > At this point, I see a similar error:
> >
> > /linux/arch/riscv/boot/dts/spacemit/k1-bananapi-f3.dtb: gpio@d4019000
> (spacemit,k1-gpio): gpio-ranges:3: [0, 64, 32] is too short
> >         from schema $id: http://devicetree.org/schemas/gpio/gpio.yaml
> >   DTC [C] arch/riscv/boot/dts/spacemit/k1-milkv-jupiter.dtb
> >
> > My understanding is that the first configuration has 5×4 elements, but the
> dt-schema seems to treat it as 4×5 elements.
> > In that case, it still aligns with 4 elements per group, so no error
> > is reported. However, when I changed it to 5×3 elements, it no longer aligns
> with 4 elements per group, which is why the error appears.
> >
> > I'm not sure if my understanding is correct. Does anyone have any good
> > suggestions on how to fix this error? I'm currently unsure about what the
> next steps should be."
> 
> You still did not explain the cells - neither in reply nor in commit - thus start
> with that. Why do you need it? Multiple controllers have groupped pins or
> GPIOs in registers, so explanation "every 32 GPIOs correspond to one register"
> tells me nothing. Why would that matter how many GPIOs is in one register?

Since every 32 GPIOs correspond to one register, Linus suggested at the time that I could try using:
gpios = <&gpio [instance] offset flags>;
gpio-ranges = <&pinctrl [gpio_instance] gpio_offset pin_offset count>;

The advantage of using this is that in a GPIO controller with more than 32 GPIOs, every 32 GPIOs 
can be treated as one GPIO bank. This way, in the driver, converting pin_offset to gpio_offset does 
not require a large number of /32 and %32 operations.

the following is Linus's original suggestion at the time
https://lore.kernel.org/all/CAD++jL=tvDBWJHRGGJw4nnox_kcJKn5hwvwz9zxadMRedyvRhw@mail.gmail.com/

Best Regards,
Changhuang

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