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

[Rob Herring <robh@kernel.org>]

On Sat, Jun 21, 2025 at 12:37:27AM +0200, Danilo Krummrich wrote:
> On Tue, Jun 17, 2025 at 08:01:08AM -0500, Rob Herring wrote:
> > On Mon, Jun 16, 2025 at 10:45 AM Remo Senekowitsch <remo@buenzli.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@buenzli.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.
> 
> Adding child nodes here creates the following dt-test failues.
> 
> 	[    1.031239] ### dt-test ### FAIL of_unittest_platform_populate():1862 Could not create device for node 'child'
> 	[    1.031647] ### dt-test ### FAIL of_unittest_platform_populate():1862 Could not create device for node 'child'
> 
> @Rob: What do you suggest?

This should fix it:

index eeb370e0f507..e3503ec20f6c 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -1856,6 +1856,8 @@ static void __init of_unittest_platform_populate(void)
        of_platform_populate(np, match, NULL, &test_bus->dev);
        for_each_child_of_node(np, child) {
                for_each_child_of_node(child, grandchild) {
+                       if (!of_property_present(grandchild, "compatible"))
+                               continue;
                        pdev = of_find_device_by_node(grandchild);
                        unittest(pdev,
                                 "Could not create device for node '%pOFn'\n",