Re: [PATCH v2 2/4] rust: nvmem: Add an abstraction for nvmem providers

Link Mauve
2026-02-05T12:48:46Z

On Wed, Feb 04, 2026 at 04:22:16PM +0100, Danilo Krummrich wrote:
> On Wed Feb 4, 2026 at 5:04 AM CET, Link Mauve wrote:
> > +impl Device {
> > + /// Register a managed nvmem provider on the given device.
> > + pub fn nvmem_register<T>(&self, mut config: NvmemConfig<T>, priv_: &T::Priv)
> > + where
> > + T: NvmemProvider + Default,
> > + {
> > + // FIXME: The last cast to mut indicates some unsoundness here.
> > + config.inner.priv_ = core::ptr::from_ref(priv_).cast::<c_void>().cast_mut();
> > + config.inner.dev = self.as_raw();
> > + config.inner.reg_read = Some(NvmemConfig::<T>::reg_read);
> > + config.inner.reg_write = Some(NvmemConfig::<T>::reg_write);
> > + // SAFETY: Both self and config can’t be null here, and should have the correct type.
> > + unsafe { bindings::devm_nvmem_register(self.as_raw(), &config.inner) };
> > + }
> > +}
>
> This should not be a method on the generic device type. Typically we use a
> Registration struct for this, i.e. this would become
> nvmem::Registration::register().

Should I also switch to the nvmem_register()/nvmem_unregister() API
instead of the devm_nvmem_register() API, so that the unregister can
happen in the Drop impl instead of being managed by the kernel?

--
Link Mauve