[PATCH RFC v4 06/12] clk: test: introduce test suite for sibling rate changes on a gate

[Brian Masney <bmasney@redhat.com>]

Introduce a test suite that creates a parent with two children: a
divider and a gate. Ensure that changing the rate of one child does
not affect the rate of the gate.

Some of the tests are disabled until the relevant issue(s) are fixed in
the clk core. This is also implemented as a parameterized kunit test
since additional test variations will be added.

Signed-off-by: Brian Masney <bmasney@redhat.com>
---
 drivers/clk/clk_test.c | 155 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 155 insertions(+)

diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c
index e798ee0591b5db6a7728eda20dcab167245a9834..5fb908a8c764f3c3d2c744022bd61e6307c890c2 100644
--- a/drivers/clk/clk_test.c
+++ b/drivers/clk/clk_test.c
@@ -831,6 +831,160 @@ static struct kunit_suite clk_rate_change_sibling_div_div_test_suite = {
 	.test_cases = clk_rate_change_sibling_div_div_cases,
 };
 
+struct clk_test_rate_change_sibling_clk_ctx {
+	struct clk *parent_clk, *child1_clk, *child2_clk;
+};
+
+static void
+clk_test_rate_change_sibling_clk_ctx_put(struct clk_test_rate_change_sibling_clk_ctx *clk_ctx)
+{
+	clk_put(clk_ctx->parent_clk);
+	clk_put(clk_ctx->child1_clk);
+	clk_put(clk_ctx->child2_clk);
+}
+
+struct clk_rate_change_sibling_div_gate_sibling_context {
+	struct clk_dummy_context parent;
+	struct clk_dummy_div child1;
+	struct clk_dummy_gate child2;
+	struct clk_test_rate_change_sibling_clk_ctx clk_ctx;
+};
+
+static struct clk_test_rate_change_sibling_clk_ctx *
+clk_rate_change_sibling_div_gate_test_init(struct kunit *test)
+{
+	struct clk_rate_change_sibling_div_gate_sibling_context *ctx;
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return ERR_PTR(-ENOMEM);
+	test->priv = ctx;
+
+	ctx->parent.hw.init = CLK_HW_INIT_NO_PARENT("parent", &clk_dummy_rate_ops, 0);
+	ctx->parent.rate = 24 * HZ_PER_MHZ;
+	ret = clk_hw_register_kunit(test, NULL, &ctx->parent.hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ctx->child1.hw.init = CLK_HW_INIT_HW("child1", &ctx->parent.hw, &clk_dummy_div_ops,
+					     CLK_SET_RATE_PARENT);
+	ctx->child1.div = 1;
+	ret = clk_hw_register_kunit(test, NULL, &ctx->child1.hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ctx->child2.hw.init = CLK_HW_INIT_HW("child2", &ctx->parent.hw, &clk_dummy_gate_ops,
+					     CLK_SET_RATE_PARENT);
+	ret = clk_hw_register_kunit(test, NULL, &ctx->child2.hw);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ctx->clk_ctx.parent_clk = clk_hw_get_clk(&ctx->parent.hw, NULL);
+	ctx->clk_ctx.child1_clk = clk_hw_get_clk(&ctx->child1.hw, NULL);
+	ctx->clk_ctx.child2_clk = clk_hw_get_clk(&ctx->child2.hw, NULL);
+
+	KUNIT_EXPECT_EQ(test, clk_get_rate(ctx->clk_ctx.parent_clk), 24 * HZ_PER_MHZ);
+
+	return &ctx->clk_ctx;
+}
+
+struct clk_test_rate_change_sibling_test_case {
+	const char *desc;
+	struct clk_test_rate_change_sibling_clk_ctx *(*init)(struct kunit *test);
+};
+
+static struct clk_test_rate_change_sibling_test_case clk_test_rate_change_sibling_test_cases[] = {
+	{
+		.desc = "div_gate",
+		.init = clk_rate_change_sibling_div_gate_test_init,
+	},
+};
+
+KUNIT_ARRAY_PARAM_DESC(clk_test_rate_change_sibling_test_case,
+		       clk_test_rate_change_sibling_test_cases, desc);
+
+/*
+ * Test that, for a parent with two children with CLK_SET_RATE_PARENT set and
+ * one requests a rate change that requires a change to the parent rate, the
+ * sibling rates are not affected.
+ */
+static void clk_test_rate_change_sibling_1(struct kunit *test)
+{
+	struct clk_test_rate_change_sibling_test_case *testcase =
+		(struct clk_test_rate_change_sibling_test_case *) test->param_value;
+	struct clk_test_rate_change_sibling_clk_ctx *ctx;
+	int ret;
+
+	kunit_skip(test, "This needs to be fixed in the core.");
+
+	ctx = testcase->init(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	KUNIT_EXPECT_EQ(test, clk_get_rate(ctx->child2_clk), 24 * HZ_PER_MHZ);
+
+	ret = clk_set_rate(ctx->child1_clk, 48 * HZ_PER_MHZ);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_GE(test, clk_get_rate(ctx->parent_clk), 48 * HZ_PER_MHZ);
+	KUNIT_EXPECT_EQ(test, clk_get_rate(ctx->child1_clk), 48 * HZ_PER_MHZ);
+	KUNIT_EXPECT_EQ(test, clk_get_rate(ctx->child2_clk), 24 * HZ_PER_MHZ);
+
+	clk_test_rate_change_sibling_clk_ctx_put(ctx);
+}
+
+/*
+ * Test that, for a parent with two children with CLK_SET_RATE_PARENT set where
+ * one requests an exclusive rate and the other requests a rate change that
+ * requires a change to the parent rate, the sibling rates are not affected.
+ */
+static void clk_test_rate_change_sibling_2(struct kunit *test)
+{
+	struct clk_test_rate_change_sibling_test_case *testcase =
+		(struct clk_test_rate_change_sibling_test_case *)(test->param_value);
+	struct clk_test_rate_change_sibling_clk_ctx *ctx;
+	int ret;
+
+	ctx = testcase->init(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	ret = clk_rate_exclusive_get(ctx->child2_clk);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_EQ(test, clk_get_rate(ctx->child2_clk), 24 * HZ_PER_MHZ);
+
+	ret = clk_set_rate(ctx->child1_clk, 48 * HZ_PER_MHZ);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_GE(test, clk_get_rate(ctx->parent_clk), 24 * HZ_PER_MHZ);
+	/* child1 is rounded to the closest supported rate */
+	KUNIT_EXPECT_EQ(test, clk_get_rate(ctx->child1_clk), 24 * HZ_PER_MHZ);
+	KUNIT_EXPECT_EQ(test, clk_get_rate(ctx->child2_clk), 24 * HZ_PER_MHZ);
+
+	clk_rate_exclusive_put(ctx->child2_clk);
+
+	clk_test_rate_change_sibling_clk_ctx_put(ctx);
+}
+
+
+static struct kunit_case clk_rate_change_sibling_cases[] = {
+	KUNIT_CASE_PARAM(clk_test_rate_change_sibling_1,
+			 clk_test_rate_change_sibling_test_case_gen_params),
+	KUNIT_CASE_PARAM(clk_test_rate_change_sibling_2,
+			 clk_test_rate_change_sibling_test_case_gen_params),
+	{}
+};
+
+/*
+ * Test suite that creates a parent with two children, where the children can
+ * be combinations of a divider, gate, and a mux. Ensure that changing the rate
+ * of one child does affect the rate of the other child.
+ */
+static struct kunit_suite clk_rate_change_sibling_test_suite = {
+	.name = "clk-rate-change-sibling",
+	.test_cases = clk_rate_change_sibling_cases,
+};
+
 static int
 clk_orphan_transparent_multiple_parent_mux_test_init(struct kunit *test)
 {
@@ -3772,6 +3926,7 @@ kunit_test_suites(
 	&clk_test_suite,
 	&clk_multiple_parents_mux_test_suite,
 	&clk_rate_change_sibling_div_div_test_suite,
+	&clk_rate_change_sibling_test_suite,
 	&clk_mux_no_reparent_test_suite,
 	&clk_mux_notifier_test_suite,
 	&clk_orphan_transparent_multiple_parent_mux_test_suite,

-- 
2.51.0