Re: [PATCH v3 1/3] rust: clk: use the type-state pattern

Boris Brezillon
2026-02-03T09:09:22Z

Hello Daniel,

On Mon, 2 Feb 2026 17:10:38 +0100
Boris Brezillon <boris.brezillon@collabora.com> wrote:

> > > -#[pin_data(PinnedDrop)]
> > > +#[pin_data]
> > > pub(crate) struct TyrData {
> > > pub(crate) pdev: ARef<platform::Device>,
> > >
> > > @@ -92,13 +92,9 @@ fn probe(
> > > pdev: &platform::Device<Core>,
> > > _info: Option<&Self::IdInfo>,
> > > ) -> impl PinInit<Self, Error> {
> > > - let core_clk = Clk::get(pdev.as_ref(), Some(c_str!("core")))?;
> > > - let stacks_clk = OptionalClk::get(pdev.as_ref(), Some(c_str!("stacks")))?;
> > > - let coregroup_clk = OptionalClk::get(pdev.as_ref(), Some(c_str!("coregroup")))?;
> > > -
> > > - core_clk.prepare_enable()?;
> > > - stacks_clk.prepare_enable()?;
> > > - coregroup_clk.prepare_enable()?;
> > > + let core_clk = Clk::<Enabled>::get(pdev.as_ref(), Some(c_str!("core")))?;
> >
> > Ah, more turbofish.. I'd really want to avoid them if possible.
> >
> > Any disadvantage on just ask the user to chain `.get().prepare_enable()?`? This
> > way it is also clear that some action is performed.
>
> I've just disc

Sorry, I've hit the reply button before I had finished writing my
answer. So I was about to say that I had started writing something
similar without knowing this series existed, and I feel like we'd don't
really need those prepare_enable() shortcuts that exist in C. We might
has well just go:

Clk::get(dev, Some(c_str!("core"))).prepare()?.enable()?;

and have the following variant-specofoc functions

- Clk<Unprepared>::get[_optional]() (no get on Prepared and Enabled
variants)
- Clk<Unprepared>::prepare()
- Clk<Prepared>::{enable,unprepare}()
- Clk<Enabled>::{disable}()

Regards,

Boris