drm/vc4: tests: Add helper to add a new plane to a state

We'll start to add some tests for the plane state logic, so let's create
a helper to add a plane to an existing atomic state.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Author: mripard

drivers/gpu/drm/vc4/tests/vc4_mock.h

@@ -39,6 +39,9 @@ struct vc4_dummy_plane {
 	struct vc4_plane plane;
 };
 
+struct vc4_dummy_plane *vc4_dummy_plane(struct kunit *test,
+					struct drm_device *drm,
+					enum drm_plane_type type);
 struct drm_plane *vc4_dummy_plane(struct kunit *test, struct drm_device *drm,
 				  enum drm_plane_type type);
 

drivers/gpu/drm/vc4/tests/vc4_mock_plane.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include <drm/drm_kunit_helpers.h>
+#include <drm/drm_atomic_uapi.h>
 #include <drm/drm_plane.h>
 
 #include <kunit/test.h>
@@ -37,3 +38,24 @@ struct drm_plane *vc4_dummy_plane(struct kunit *test, struct drm_device *drm,
 
 	return plane;
 }
+
+struct drm_plane *
+vc4_mock_atomic_add_plane(struct kunit *test,
+			  struct drm_atomic_state *state,
+			  struct drm_crtc *crtc)
+{
+	struct drm_plane_state *plane_state;
+	struct drm_plane *plane;
+	int ret;
+
+	plane = vc4_mock_find_plane_for_crtc(test, crtc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, plane);
+
+	plane_state = drm_atomic_get_plane_state(state, plane);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, plane_state);
+
+	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+
+	return plane;
+}