drm/tests: Add test cases for drm_rect_calc_vscale()

Insert parameterized test for the drm_rect_calc_vscale() to ensure
correctness and prevent future regressions. Besides the test for the
usual case, tests the exceptions.

It uses the same struct from drm_rect_calc_hscale().
Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Maíra Canal <mairacanal@riseup.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20230418230146.461129-4-arthurgrillo@riseup.net

drivers/gpu/drm/tests/drm_rect_test.c

@@ -414,6 +414,17 @@ static void drm_test_rect_calc_hscale(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor);
 }
 
+static void drm_test_rect_calc_vscale(struct kunit *test)
+{
+	const struct drm_rect_scale_case *params = test->param_value;
+	int scaling_factor;
+
+	scaling_factor = drm_rect_calc_vscale(&params->src, &params->dst,
+					      params->min_range, params->max_range);
+
+	KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor);
+}
+
 static struct kunit_case drm_rect_tests[] = {
 	KUNIT_CASE(drm_test_rect_clip_scaled_div_by_zero),
 	KUNIT_CASE(drm_test_rect_clip_scaled_not_clipped),
@@ -421,6 +432,7 @@ static struct kunit_case drm_rect_tests[] = {
 	KUNIT_CASE(drm_test_rect_clip_scaled_signed_vs_unsigned),
 	KUNIT_CASE_PARAM(drm_test_rect_intersect, drm_rect_intersect_gen_params),
 	KUNIT_CASE_PARAM(drm_test_rect_calc_hscale, drm_rect_scale_gen_params),
+	KUNIT_CASE_PARAM(drm_test_rect_calc_vscale, drm_rect_scale_gen_params),
 	{ }
 };