drm/tests: helpers: Create the device in another function

We'll need in some tests to control when the device needs to be added
and removed, so let's split the device creation from the DRM device
creation function.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-7-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

1 files changed, 33 insertions, 23 deletions

diff --git a/drivers/gpu/drm/tests/drm_kunit_helpers.c b/drivers/gpu/drm/tests/drm_kunit_helpers.c
index ec33fcbd092d..4bf98bd0a8c6 100644
--- a/drivers/gpu/drm/tests/drm_kunit_helpers.c
+++ b/drivers/gpu/drm/tests/drm_kunit_helpers.c
@@ -17,36 +17,51 @@ struct kunit_dev {
 static const struct drm_mode_config_funcs drm_mode_config_funcs = {
 };
 
-static int dev_init(struct kunit_resource *res, void *ptr)
+/**
+ * drm_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.
+ *
+ * Callers need to make sure drm_kunit_helper_free_device() on the
+ * device when done.
+ *
+ * Returns:
+ * A pointer to the new device, or an ERR_PTR() otherwise.
+ */
+struct device *drm_kunit_helper_alloc_device(struct kunit *test)
 {
-	char *name = ptr;
-	struct device *dev;
-
-	dev = root_device_register(name);
-	if (IS_ERR(dev))
-		return PTR_ERR(dev);
-
-	res->data = dev;
-	return 0;
+	return root_device_register(KUNIT_DEVICE_NAME);
 }
+EXPORT_SYMBOL_GPL(drm_kunit_helper_alloc_device);
 
-static void dev_free(struct kunit_resource *res)
+/**
+ * drm_kunit_helper_free_device - Frees a mock device
+ * @test: The test context object
+ * @dev: The device to free
+ *
+ * Frees a device allocated with drm_kunit_helper_alloc_device().
+ */
+void drm_kunit_helper_free_device(struct kunit *test, struct device *dev)
 {
-	struct device *dev = res->data;
-
 	root_device_unregister(dev);
 }
+EXPORT_SYMBOL_GPL(drm_kunit_helper_free_device);
 
 /**
  * drm_kunit_helper_alloc_drm_device - Allocates a mock DRM device for KUnit tests
  * @test: The test context object
+ * @dev: The parent device object
  * @features: Mocked DRM device driver features
  *
- * This function allocates a new struct &device, creates a struct
- * &drm_driver and will create a struct &drm_device using both.
+ * This function creates a struct &drm_driver and will create a struct
+ * &drm_device from @dev and that driver.
+ *
+ * @dev should be allocated using drm_kunit_helper_alloc_device().
  *
- * The device and driver are tied to the @test context and will get
- * cleaned at the end of the test. The drm_device is allocated through
+ * The driver is tied to the @test context and will get cleaned at the
+ * end of the test. The drm_device is allocated through
  * devm_drm_dev_alloc() and will thus be freed through a device-managed
  * resource.
  *
@@ -54,19 +69,14 @@ static void dev_free(struct kunit_resource *res)
  * A pointer to the new drm_device, or an ERR_PTR() otherwise.
  */
 struct drm_device *
-drm_kunit_helper_alloc_drm_device(struct kunit *test,
+drm_kunit_helper_alloc_drm_device(struct kunit *test, struct device *dev,
 				  u32 features)
 {
 	struct kunit_dev *kdev;
 	struct drm_device *drm;
 	struct drm_driver *driver;
-	struct device *dev;
 	int ret;
 
-	dev = kunit_alloc_resource(test, dev_init, dev_free, GFP_KERNEL, KUNIT_DEVICE_NAME);
-	if (!dev)
-		return ERR_PTR(-ENOMEM);
-
 	driver = kunit_kzalloc(test, sizeof(*driver), GFP_KERNEL);
 	if (!driver)
 		return ERR_PTR(-ENOMEM);