On Wed, Mar 22, 2023 at 11:05:55AM +0200, Matti Vaittinen wrote: > --- /dev/null > +++ b/drivers/base/test/test_kunit_device.c > @@ -0,0 +1,83 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * These helpers have been extracted from drm test code at > + * drm_kunit_helpers.c which was authored by > + * Maxime Ripard <maxime@xxxxxxxxxx> > + */ > + > +#include <linux/device.h> > +#include <linux/platform_device.h> > + > +#include <kunit/platform_device.h> > + > +#define KUNIT_DEVICE_NAME "test-kunit-mock-device" > + > +static int fake_probe(struct platform_device *pdev) Please do not abuse platform devices and drivers for things that are not actually platform devices and drivers. > +{ > + return 0; > +} > + > +static int fake_remove(struct platform_device *pdev) > +{ > + return 0; > +} > + > +static struct platform_driver fake_platform_driver = { > + .probe = fake_probe, > + .remove = fake_remove, > + .driver = { > + .name = KUNIT_DEVICE_NAME, > + }, > +}; Why do you need this fake platform driver at all? Why not just use a virtual device? > + > +/** > + * 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? Again, please do not abuse the platform device infrastructure for things it was never ment to do (i.e. create fake devices that are not really a platform device.) thanks, greg k-h