Re: [PATCH v2 5/5] samples: rust: add ACPI match table example to platform driver

[Danilo Krummrich <dakr@kernel.org>]

On Thu, Jun 05, 2025 at 05:52:31PM +0100, Igor Korotin wrote:
> Extend the Rust sample platform driver to probe using device/driver name
> matching, OF ID table matching, or ACPI ID table matching.
> 
> Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com>
> ---
>  samples/rust/rust_driver_platform.rs | 40 +++++++++++++++++++++++++++-
>  1 file changed, 39 insertions(+), 1 deletion(-)
> 
> diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
> index e3992e7a71e9..ee0780c1d6ae 100644
> --- a/samples/rust/rust_driver_platform.rs
> +++ b/samples/rust/rust_driver_platform.rs
> @@ -17,10 +17,48 @@ struct SampleDriver {
>      [(of::DeviceId::new(c_str!("test,rust-device")), Info(42))]
>  );
>  
> +kernel::acpi_device_table!(
> +    ACPI_TABLE,
> +    MODULE_ACPI_TABLE,
> +    <SampleDriver as platform::Driver>::IdInfo,
> +    [(acpi::DeviceId::new(c_str!("TEST4321")), Info(0))]

Can you please explain add a comment explaining how to make this probe? In the
cover letter you mention:

"Tested using QEMU with a custom SSDT that creates an ACPI device matching the
sample Rust platform driver."

> +);
> +
> +/// OF/ACPI match tables for Platform Driver implementation
> +///
> +/// The platform::Driver requires declaration of both OF_ID_TABLE and
> +/// ACPI_ID_TABLE, but if driver is not going to use either of them
> +/// it can implement one of them or both as None.
> +///
> +/// # Example:
> +///
> +///```
> +/// impl platform::Driver for SampleDriver {
> +///     type IdInfo = Info;
> +///     const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None;
> +///     const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = None;
> +///
> +///     fn probe(
> +///         pdev: &platform::Device<Core>,
> +///         info: Option<&Self::IdInfo>,
> +///     ) -> Result<Pin<KBox<Self>>> {
> +///         dev_dbg!(pdev.as_ref(), "Probe Rust Platform driver sample.\n");
> +///
> +///         if let Some(info) = info {
> +///             dev_info!(pdev.as_ref(), "Probed with info: '{}'.\n", info.0);
> +///         }
> +///
> +///         let drvdata = KBox::new(Self { pdev: pdev.into() }, GFP_KERNEL)?;
> +///
> +///         Ok(drvdata.into())
> +///     }
> +/// }
> +///```

I assume you want to make clear that both the ACPI and OF table are optional;
not sure of that's required given their type is Option<...>. But I'm fine having
this additional comment and example.

Please make sure that it compiles though and remove everything unnecessary from
probe() please.

> +
>  impl platform::Driver for SampleDriver {
>      type IdInfo = Info;
>      const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
> -    const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = None;
> +    const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
>  
>      fn probe(
>          pdev: &platform::Device<Core>,
> -- 
> 2.43.0
>