回复: [PATCH] Pinctrl: core: export pinctrl_provide_dummies() to fix build error

[Gary Yang]

Hi Linus,

> EXTERNAL EMAIL
> 
> On Wed, Oct 29, 2025 at 4:35 AM Gary Yang <gary.yang at cixtech.com> wrote:
> 
> 
> > Generally a device may has two states: default state and sleep state. They are
> included in DTS file.
> > So DTS has two nodes, one is for default state, and the other is for
> > sleep state. When the device works, select default state, but select sleep
> state when the system enters str.
> 
> What is "str"? stand-by-retention? (Sorry for my ignorance.)
> 

Sorry, we forgot to explain it before. Str means suspend to RAM

> > There is two pinctrl controllers on CIX sky1. One is used under S0 state, and
> the other is used under S0 and S5 state.
> > When enter str, the system enter S3 state and S0 domain power off. So the
> pinctrl controller under S0 state is also off.
> > The settings for sleep state are loft and make no sense.
> >
> > But if we remove these settings, the pinctrl can't find sleep state and can't
> change state when system enter str.
> > When resume pinctrl, pinctrl core may think state is still the same as
> > before. So the settings can't be applied as expected.
> 
> Aha!
> 
> > To avoid write these unused settings in DTS file, we have to use
> pinctrl_provide_dummies() interface.
> > Do you agree our schemes? What's your opinion? Please give us some
> > suggestions. Thanks
> 
> I think it's fine to use the pinctrl dummies, I will draft a patch and send so you
> can ACK it.
> 
> It's fun to get the whole picture of how this works on CIX silicon, it's a new way
> of doing things with two different pin controllers so I haven't seen this before!
> 

Great! It's a big surprise!
Thanks for your understandings

> Yours,
> Linus Walleij