[PATCH v7 2/2] drm/tests: bridge: add a KUnit test for devm_drm_bridge_alloc()

[Luca Ceresoli <luca.ceresoli@bootlin.com>]

Add a basic KUnit test for the newly introduced drm_bridge_alloc().

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

---

Changed in v7:
 - rebase on current drm-misc-next, which now has a drm_bridge_test.c file
 - cleanup commit message

Changed in v6:
 - update to new devm_drm_bridge_alloc() API
 - remove drm_test_drm_bridge_put test, not straightforward to write with
   the new API and the current notification mechanism
 - do not allocate a drm_device: a bridge is allocated without one
 - rename some identifiers for easier code reading

This patch was added in v5.
---
 drivers/gpu/drm/tests/drm_bridge_test.c | 60 +++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_bridge_test.c b/drivers/gpu/drm/tests/drm_bridge_test.c
index ff88ec2e911c9cc9a718483f09d4c764f45f991a..87fb64744b67f0780457a546aba77ba945a0ce67 100644
--- a/drivers/gpu/drm/tests/drm_bridge_test.c
+++ b/drivers/gpu/drm/tests/drm_bridge_test.c
@@ -8,6 +8,7 @@
 #include <drm/drm_bridge_helper.h>
 #include <drm/drm_kunit_helpers.h>
 
+#include <kunit/device.h>
 #include <kunit/test.h>
 
 struct drm_bridge_init_priv {
@@ -407,11 +408,70 @@ static struct kunit_suite drm_bridge_helper_reset_crtc_test_suite = {
 	.test_cases = drm_bridge_helper_reset_crtc_tests,
 };
 
+struct drm_bridge_alloc_test_ctx {
+	struct device *dev;
+};
+
+/*
+ * Mimick the typical struct defined by a bridge driver, which embeds a
+ * bridge plus other fields.
+ */
+struct dummy_drm_bridge {
+	int dummy; // ensure we test non-zero @bridge offset
+	struct drm_bridge bridge;
+};
+
+static const struct drm_bridge_funcs drm_bridge_dummy_funcs = {
+};
+
+static int drm_test_bridge_alloc_init(struct kunit *test)
+{
+	struct drm_bridge_alloc_test_ctx *ctx;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	ctx->dev = kunit_device_register(test, "drm-bridge-dev");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->dev);
+
+	test->priv = ctx;
+
+	return 0;
+}
+
+/*
+ * Test that the allocation and initialization of a bridge works as
+ * expected and doesn't report any error.
+ */
+static void drm_test_drm_bridge_alloc(struct kunit *test)
+{
+	struct drm_bridge_alloc_test_ctx *ctx = test->priv;
+	struct dummy_drm_bridge *dummy;
+
+	dummy = devm_drm_bridge_alloc(ctx->dev, struct dummy_drm_bridge, bridge,
+				      &drm_bridge_dummy_funcs);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dummy);
+}
+
+static struct kunit_case drm_bridge_alloc_tests[] = {
+	KUNIT_CASE(drm_test_drm_bridge_alloc),
+	{ }
+};
+
+static struct kunit_suite drm_bridge_alloc_test_suite = {
+	.name = "drm_bridge_alloc",
+	.init = drm_test_bridge_alloc_init,
+	.test_cases = drm_bridge_alloc_tests,
+};
+
 kunit_test_suites(
 	&drm_bridge_get_current_state_test_suite,
 	&drm_bridge_helper_reset_crtc_test_suite,
+	&drm_bridge_alloc_test_suite,
 );
 
 MODULE_AUTHOR("Maxime Ripard <mripard@kernel.org>");
+MODULE_AUTHOR("Luca Ceresoli <luca.ceresoli@bootlin.com>");
+
 MODULE_DESCRIPTION("Kunit test for drm_bridge functions");
 MODULE_LICENSE("GPL");

-- 
2.49.0