Re: [PATCH v2 4/4] samples: rust: add Rust manual I2C device creation sample

[Danilo Krummrich <dakr@kernel.org>]

On Fri, Jul 04, 2025 at 04:43:41PM +0100, Igor Korotin wrote:
> +struct SampleDriver {
> +    _owned: i2c::DeviceOwned<Core>,
> +}
> +
> +const BOARD_INFO: i2c::I2cBoardInfo = i2c::I2cBoardInfo::new(c_str!("rust_driver_i2c"), 0x30);
> +
> +impl kernel::Module for SampleDriver {
> +    fn init(_module: &'static ThisModule) -> Result<Self> {
> +        pr_debug!("Probe Rust I2C device sample.\n");
> +
> +        let adapter = i2c::I2cAdapterRef::get(0).ok_or(EINVAL)?;
> +
> +        let device = i2c::DeviceOwned::<Core>::new(&adapter, &BOARD_INFO).ok_or(EINVAL)?;

This can't be device::Core, since the scope of device is not limited to I2C bus
callback. Also, device::Core dereferences to device::Bound, and device is also
not limited to scope where it can be guaranteed that the device is actually
bound.

It could be device::Normal, but as mentioned in the other thread, you're
thinking this too complicated. You really want t simple i2c::Registration type,
just like auxiliary::Registration. Please take a look at that instead.

> +        Ok(Self { _owned: device })
> +    }
> +}