drm/tests: Add helper to create mock crtc

[ Upstream commit 51f90720381dea79208513d059e0eb426dee511e ]

We're going to need a full-blown, functional, KMS device to test more
components of the atomic modesetting infrastructure.

Let's add a new helper to create a dumb, mocked, CRTC. By default it
will create a CRTC relying only on the default helpers, but drivers are
free to deviate from that.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240222-kms-hdmi-connector-state-v7-4-8f4af575fce2@kernel.org
Stable-dep-of: 70f29ca3117a ("drm/tests: cmdline: Fix drm_display_mode memory leak")
Signed-off-by: Sasha Levin <sashal@kernel.org>

1 files changed, 62 insertions, 0 deletions

diff --git a/drivers/gpu/drm/tests/drm_kunit_helpers.c b/drivers/gpu/drm/tests/drm_kunit_helpers.c
index e0778a7ec260..ca513235b5e2 100644
--- a/drivers/gpu/drm/tests/drm_kunit_helpers.c
+++ b/drivers/gpu/drm/tests/drm_kunit_helpers.c
@@ -321,5 +321,67 @@ drm_kunit_helper_create_primary_plane(struct kunit *test,
 }
 EXPORT_SYMBOL_GPL(drm_kunit_helper_create_primary_plane);
 
+static const struct drm_crtc_helper_funcs default_crtc_helper_funcs = {
+};
+
+static const struct drm_crtc_funcs default_crtc_funcs = {
+	.atomic_destroy_state   = drm_atomic_helper_crtc_destroy_state,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.reset                  = drm_atomic_helper_crtc_reset,
+};
+
+/**
+ * drm_kunit_helper_create_crtc - Creates a mock CRTC for a KUnit test
+ * @test: The test context object
+ * @drm: The device to alloc the plane for
+ * @primary: Primary plane for CRTC
+ * @cursor: Cursor plane for CRTC. Optional.
+ * @funcs: Callbacks for the new plane. Optional.
+ * @helper_funcs: Helpers callbacks for the new plane. Optional.
+ *
+ * This allocates and initializes a mock struct &drm_crtc meant to be
+ * part of a mock device for a KUnit test.
+ *
+ * Resources will be cleaned up automatically.
+ *
+ * @funcs will default to the default helpers implementations.
+ * @helper_funcs will default to an empty implementation.
+ *
+ * Returns:
+ * A pointer to the new CRTC, or an ERR_PTR() otherwise.
+ */
+struct drm_crtc *
+drm_kunit_helper_create_crtc(struct kunit *test,
+			     struct drm_device *drm,
+			     struct drm_plane *primary,
+			     struct drm_plane *cursor,
+			     const struct drm_crtc_funcs *funcs,
+			     const struct drm_crtc_helper_funcs *helper_funcs)
+{
+	struct drm_crtc *crtc;
+	int ret;
+
+	if (!funcs)
+		funcs = &default_crtc_funcs;
+
+	if (!helper_funcs)
+		helper_funcs = &default_crtc_helper_funcs;
+
+	crtc = drmm_kzalloc(drm, sizeof(*crtc), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, crtc);
+
+	ret = drmm_crtc_init_with_planes(drm, crtc,
+					 primary,
+					 cursor,
+					 funcs,
+					 NULL);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	drm_crtc_helper_add(crtc, helper_funcs);
+
+	return crtc;
+}
+EXPORT_SYMBOL_GPL(drm_kunit_helper_create_crtc);
+
 MODULE_AUTHOR("Maxime Ripard <maxime@cerno.tech>");
 MODULE_LICENSE("GPL");