[PATCH v2 02/41] drm/tests: Add Kunit Helpers

[Maxime Ripard]

As the number of kunit tests in KMS grows further, we start to have
multiple test suites that, for example, need to register a mock DRM
driver to interact with the KMS function they are supposed to test.

Let's add a file meant to provide those kind of helpers to avoid
duplication.

Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/tests/Makefile b/drivers/gpu/drm/tests/Makefile
index 2d9f49b62ecb..b29ef1085cad 100644
--- a/drivers/gpu/drm/tests/Makefile
+++ b/drivers/gpu/drm/tests/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_DRM_KUNIT_TEST) += \
 	drm_format_helper_test.o \
 	drm_format_test.o \
 	drm_framebuffer_test.o \
+	drm_kunit_helpers.o \
 	drm_mm_test.o \
 	drm_plane_helper_test.o \
 	drm_rect_test.o
diff --git a/drivers/gpu/drm/tests/drm_kunit_helpers.c b/drivers/gpu/drm/tests/drm_kunit_helpers.c
new file mode 100644
index 000000000000..7ebd620481c1
--- /dev/null
+++ b/drivers/gpu/drm/tests/drm_kunit_helpers.c
@@ -0,0 +1,54 @@
+#include <drm/drm_drv.h>
+#include <drm/drm_managed.h>
+
+#include <linux/device.h>
+
+static const struct drm_mode_config_funcs drm_mode_config_funcs = {
+};
+
+static const struct drm_driver drm_mode_driver = {
+};
+
+static void drm_kunit_free_device(struct drm_device *drm, void *ptr)
+{
+	struct device *dev = ptr;
+
+	root_device_unregister(dev);
+}
+
+struct drm_device *drm_kunit_device_init(const char *name)
+{
+	struct drm_device *drm;
+	struct device *dev;
+	int ret;
+
+	dev = root_device_register(name);
+	if (IS_ERR(dev))
+		return ERR_CAST(dev);
+
+	drm = drm_dev_alloc(&drm_mode_driver, dev);
+	if (IS_ERR(drm)) {
+		root_device_unregister(dev);
+		return ERR_CAST(drm);
+	}
+	drm->mode_config.funcs = &drm_mode_config_funcs;
+
+	ret = drmm_add_action_or_reset(drm, drm_kunit_free_device, dev);
+	if (ret)
+		goto err_put_device;
+
+	ret = drmm_mode_config_init(drm);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return drm;
+
+err_put_device:
+	drm_dev_put(drm);
+	return ERR_PTR(ret);
+}
+
+void drm_kunit_device_exit(struct drm_device *drm)
+{
+	drm_dev_put(drm);
+}
diff --git a/drivers/gpu/drm/tests/drm_kunit_helpers.h b/drivers/gpu/drm/tests/drm_kunit_helpers.h
new file mode 100644
index 000000000000..5015a327a8c1
--- /dev/null
+++ b/drivers/gpu/drm/tests/drm_kunit_helpers.h
@@ -0,0 +1,9 @@
+#ifndef DRM_KUNIT_HELPERS_H_
+#define DRM_KUNIT_HELPERS_H_
+
+struct drm_device;
+
+struct drm_device *drm_kunit_device_init(const char *name);
+void drm_kunit_device_exit(struct drm_device *drm);
+
+#endif // DRM_KUNIT_HELPERS_H_

-- 
b4 0.10.0-dev-65ba7