Re: [PATCH v3 16/16] samples: rust: add Rust platform sample driver

[Rob Herring <robh@kernel.org>]

On Wed, Oct 23, 2024 at 08:59:48AM +0200, Danilo Krummrich wrote:
> On Tue, Oct 22, 2024 at 07:04:08PM -0500, Rob Herring wrote:
> > On Tue, Oct 22, 2024 at 11:31:53PM +0200, Danilo Krummrich wrote:
> > > Add a sample Rust platform driver illustrating the usage of the platform
> > > bus abstractions.
> > > 
> > > This driver probes through either a match of device / driver name or a
> > > match within the OF ID table.
> > 
> > I know if rust compiles it works, but how does one actually use/test 
> > this? (I know ways, but I might be in the minority. :) )
> 
> For testing a name match I just used platform_device_register_simple() in a
> separate module.
> 
> Probing through the OF table is indeed a bit more tricky. Since I was too lazy
> to pull out a random ARM device of my cupboard I just used QEMU on x86 and did
> what drivers/of/unittest.c does. If you're smart you can also just enable those
> unit tests and change the compatible string to "unittest". :)
> 
> > 
> > The DT unittests already define test platform devices. I'd be happy to 
> > add a device node there. Then you don't have to muck with the DT on some 
> > device and it even works on x86 or UML.
> 
> Sounds good, I'll add one in there for this sample driver -- any preferences?

I gave this a spin and added the patch below in. Feel free to squash it 
into this one.

8<----------------------------------------------------------------
From: "Rob Herring (Arm)" <robh@kernel.org>
Date: Wed, 23 Oct 2024 10:29:47 -0500
Subject: [PATCH] of: unittest: Add a platform device node for rust platform
 driver sample

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

diff --git a/drivers/of/unittest-data/tests-platform.dtsi b/drivers/of/unittest-data/tests-platform.dtsi
index fa39611071b3..575ea260a877 100644
--- a/drivers/of/unittest-data/tests-platform.dtsi
+++ b/drivers/of/unittest-data/tests-platform.dtsi
@@ -33,6 +33,11 @@ dev@100 {
                                        reg = <0x100>;
                                };
                        };
+
+                       test-device@2 {
+                               compatible = "test,rust-device";
+                               reg = <0x2>;
+                       };
                };
        };
 };
diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
index 55caaaa4f216..5cf4a8f86c13 100644
--- a/samples/rust/rust_driver_platform.rs
+++ b/samples/rust/rust_driver_platform.rs
@@ -15,7 +15,7 @@ struct SampleDriver {
     MODULE_OF_TABLE,
     <SampleDriver as platform::Driver>::IdInfo,
     [(
-        of::DeviceId::new(c_str!("redhat,rust-sample-platform-driver")),
+        of::DeviceId::new(c_str!("test,rust-device")),
         Info(42)
     )]
 );