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

[Changhuang Liang]

Hi, Rob, Krzysztof, Conor

> On Mon, Aug 17, 2026 at 02:45:22PM +0200, Linus Walleij wrote:
> > On Fri, Aug 14, 2026 at 1:22 PM Changhuang Liang
> > <changhuang.liang@xxxxxxxxxxxxxxxx> wrote:
> >
> > > > 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_kcJKn5hwvwz9zx
> > > adMRedyvRhw@xxxxxxxxxxxxxx/
> >
> > Just copy this explanation into the commit so it is clear why you need
> > three cells for this.
> 
> "Can use gpiolib" is not really justification. Neither is avoiding a shift and/or
> mask. I suppose there's some h/w attribute here to justify it?

I'll go ahead and send out a new version per Linus's suggestion. In the meantime, 
if anyone has any additional thoughts or further feedback, I'd be more than happy 
to incorporate them. Please don't hesitate to let me know!

Best Regards,
Changhuang