Hi Bartosz, Alexandre,

Thank you for your advice.

> >> The best approach I think is a combination of a Rust consumer driver and
> >> a C kunit module dedicated to testing the consumer driver. This is
> >> almost the same as `drivers/gpio/gpiolib-kunit.c`, except that instead
> >> of directly exercising the GPIO consumer APIs, the module I'm suggesting
> >> exercises them indirectly, through the Rust consumer driver.
> >>
> >
> > Can't you just call a C function registering the platform device from unsafe
> > rust?
> 
> You should be able to. It's a but laborious, but better than not having
> tests at all, and acceptable as a temporary solution IMHO.
> 
> Of course an even better solution would be to provide a safe abstraction
> for registering platform devices. :) I don't know exactly how much work
> that would be, but there is already a `platform` module, so supposedly
> we wouldn't be starting from absolute scratch.

Sure. I'll explore the Rust kunit approach by directly calling C
functions to register `platform_device` and `software_node` from unsafe
Rust. I'll also drop the sample driver. I'll let you know if I face
problems.

Best regards,
Kohei Ito