Re: [PATCH v2 5/5] samples: rust: platform: Add property read examples

[Dirk Behme]

On 23/04/2025 14:39, Dirk Behme wrote:
> Hi Remo,
> 
> On 14/04/2025 17:26, Remo Senekowitsch wrote:
>> Add some example usage of the device property read methods for
>> DT/ACPI/swnode properties.
>>
>> Co-developed-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
>> Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
>> Signed-off-by: Remo Senekowitsch <remo@xxxxxxxxxxx>
>> ---
>>  drivers/of/unittest-data/tests-platform.dtsi |  3 +
>>  samples/rust/rust_driver_platform.rs         | 69 +++++++++++++++++++-
>>  2 files changed, 69 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/of/unittest-data/tests-platform.dtsi b/drivers/of/unittest-data/tests-platform.dtsi
>> index 4171f43cf..50a51f38a 100644
>> --- a/drivers/of/unittest-data/tests-platform.dtsi
>> +++ b/drivers/of/unittest-data/tests-platform.dtsi
>> @@ -37,6 +37,9 @@ dev@100 {
>>  			test-device@2 {
>>  				compatible = "test,rust-device";
>>  				reg = <0x2>;
>> +
>> +				test,u32-prop = <0xdeadbeef>;
>> +				test,i16-array = /bits/ 16 <1 2 (-3) (-4)>;
> 
> 
> Is "test,u32-required-prop" missing here? See below ...

Ah, no, sorry, "test,u32-required-prop" isn't there intentionally to
demonstrate the error handling on missing required properties. In this
case I would propose to just remove the '?' to make the sample code not
exit on this intended error:

diff --git a/samples/rust/rust_driver_platform.rs
b/samples/rust/rust_driver_platform.rs
index 01902956e1ca7..b6cbd721a8882 100644
--- a/samples/rust/rust_driver_platform.rs
+++ b/samples/rust/rust_driver_platform.rs
@@ -75,7 +75,7 @@ fn properties_parse(dev: &kernel::device::Device) ->
Result<()> {
         // Missing property without a default will print an error
         let _ = dev
             .property_read::<u32>(c_str!("test,u32-required-prop"))
-            .required()?;
+            .required();

         let prop: u32 =
dev.property_read(c_str!("test,u32-prop")).required()?;
         dev_info!(dev, "'test,u32-prop' is {:#x}\n", prop);

Best regards

Dirk