On Wed, Mar 22, 2023 at 07:57:10PM +0100, Greg Kroah-Hartman wrote:
> > > > +/**
> > > > + * test_kunit_helper_alloc_device - Allocate a mock device for a KUnit test
> > > > + * @test: The test context object
> > > > + *
> > > > + * This allocates a fake struct &device to create a mock for a KUnit
> > > > + * test. The device will also be bound to a fake driver. It will thus be
> > > > + * able to leverage the usual infrastructure and most notably the
> > > > + * device-managed resources just like a "real" device.
> > > 
> > > What specific "usual infrastructure" are you wanting to access here?
> > > 
> > > And again, if you want a fake device, make a virtual one, by just
> > > calling device_create().
> > > 
> > > Or are you wanting to do "more" with that device pointer than
> > > device_create() can give you?
> > 
> > Personally, I was (am) only interested in devm_ unwinding. I guess the
> > device_create(), device_add(), device_remove()... (didn't study this
> > sequence in details so sorry if there is errors) could've been sufficient
> > for me. I haven't looked how much of the code that there is for 'platform
> > devices' should be duplicated to support that sequence for testability
> > purposes.
> 
> Any device can access devm_ code, there's no need for it to be a
> platform device at all.

Sure but the resources are only released if the device is part of a bus,
so it can't be a root_device (or bare device) either

Maxime