linux-kernel - Re: [PATCH v1 3/3] samples: rust: platform: Add property child and reference args examples

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAL_JsqKXrsdGjTE5KDkqmVHUK5urMJnWSLWgEi8H1yM21gcOCA@mail.gmail.com>
Date: Tue, 17 Jun 2025 08:01:08 -0500
From: Rob Herring <robh@...nel.org>
To: Remo Senekowitsch <remo@...nzli.dev>
Cc: Saravana Kannan <saravanak@...gle.com>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
	"Rafael J. Wysocki" <rafael@...nel.org>, Danilo Krummrich <dakr@...nel.org>, Miguel Ojeda <ojeda@...nel.org>, 
	Alex Gaynor <alex.gaynor@...il.com>, Boqun Feng <boqun.feng@...il.com>, 
	Gary Guo <gary@...yguo.net>, Björn Roy Baron <bjorn3_gh@...tonmail.com>, 
	Benno Lossin <lossin@...nel.org>, Andreas Hindborg <a.hindborg@...nel.org>, 
	Alice Ryhl <aliceryhl@...gle.com>, Trevor Gross <tmgross@...ch.edu>, 
	Mark Brown <broonie@...nel.org>, Dirk Behme <dirk.behme@...bosch.com>, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org, rust-for-linux@...r.kernel.org
Subject: Re: [PATCH v1 3/3] samples: rust: platform: Add property child and
 reference args examples

On Mon, Jun 16, 2025 at 10:45 AM Remo Senekowitsch <remo@...nzli.dev> wrote:
>
> Add some example usage of the device property methods for reading
> DT/ACPI/swnode child nodes and reference args.
>
> Signed-off-by: Remo Senekowitsch <remo@...nzli.dev>
> ---
>  drivers/of/unittest-data/tests-platform.dtsi |  7 +++++++
>  samples/rust/rust_driver_platform.rs         | 13 ++++++++++++-
>  2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/unittest-data/tests-platform.dtsi b/drivers/of/unittest-data/tests-platform.dtsi
> index 50a51f38afb6..509eb614ab2b 100644
> --- a/drivers/of/unittest-data/tests-platform.dtsi
> +++ b/drivers/of/unittest-data/tests-platform.dtsi
> @@ -40,6 +40,13 @@ test-device@2 {
>
>                                 test,u32-prop = <0xdeadbeef>;
>                                 test,i16-array = /bits/ 16 <1 2 (-3) (-4)>;
> +
> +                               ref_child_0: child@0 {

child-0 or you need to add 'reg' property if you keep the unit-address.

> +                                       test,ref-arg = <&ref_child_1 0x20 0x32>;
> +                               };
> +                               ref_child_1: child@1 {
> +                                       test,ref-arg = <&ref_child_0 0x10 0x64>;
> +                               };
>                         };
>                 };
>
> diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
> index c0abf78d0683..4dcedb22a4bb 100644
> --- a/samples/rust/rust_driver_platform.rs
> +++ b/samples/rust/rust_driver_platform.rs
> @@ -4,7 +4,11 @@
>
>  use kernel::{
>      c_str,
> -    device::{self, Core},
> +    device::{
> +        self,
> +        property::{FwNodeReferenceArgs, NArgs},
> +        Core,
> +    },
>      of, platform,
>      prelude::*,
>      str::CString,
> @@ -91,6 +95,13 @@ fn properties_parse(dev: &device::Device) -> Result {
>          let prop: KVec<i16> = fwnode.property_read_array_vec(name, 4)?.required_by(dev)?;
>          dev_info!(dev, "'{name}'='{prop:?}' (KVec)\n");
>
> +        for child in fwnode.children() {
> +            let name = c_str!("test,ref-arg");
> +            let nargs = NArgs::N(2);
> +            let prop: FwNodeReferenceArgs = child.property_get_reference_args(name, nargs, 0)?;

Is there some reason we can just pass 2 in rather than nargs? Seems
overly verbose for my tastes.

> +            dev_info!(dev, "'{name}'='{prop:?}'\n");
> +        }
> +
>          Ok(())
>      }
>  }
> --
> 2.49.0
>