[PATCH v6 22/28] clk: Introduce clk_core_has_parent()

Maxime Ripard
2022-07-11T15:25:12Z

We will need to know if a clk_core pointer has a given parent in other
functions, so let's create a clk_core_has_parent() function that
clk_has_parent() will call into.

For good measure, let's add some unit tests as well to make sure it
works properly.

Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> # imx8mp
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> # exynos4210, meson g12b
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
drivers/clk/clk.c | 36 ++++++++++++++++++++---------------
drivers/clk/clk_test.c | 43 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 64 insertions(+), 15 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index ad851afcfdd2..7fc6347e66c6 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -539,6 +539,26 @@ static bool mux_is_better_rate(unsigned long rate, unsigned long now,
static int clk_core_round_rate_nolock(struct clk_core *core,
struct clk_rate_request *req);

+static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
+{
+ unsigned int i;
+
+ /* Optimize for the case where the parent is already the parent. */
+ if (core == parent)
+ return true;
+
+ for (i = 0; i < core->num_parents; i++) {
+ struct clk_core *tmp = clk_core_get_parent_by_index(core, i);
+ if (!tmp)
+ continue;
+
+ if (tmp == parent)
+ return true;
+ }
+
+ return false;
+}
+
int clk_mux_determine_rate_flags(struct clk_hw *hw,
struct clk_rate_request *req,
unsigned long flags)
@@ -2570,25 +2590,11 @@ void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
*/
bool clk_has_parent(struct clk *clk, struct clk *parent)
{
- struct clk_core *core, *parent_core;
- int i;
-
/* NULL clocks should be nops, so return success if either is NULL. */
if (!clk || !parent)
return true;

- core = clk->core;
- parent_core = parent->core;
-
- /* Optimize for the case where the parent is already the parent. */
- if (core->parent == parent_core)
- return true;
-
- for (i = 0; i < core->num_parents; i++)
- if (!strcmp(core->parents[i].name, parent_core->name))
- return true;
-
- return false;
+ return clk_core_has_parent(clk->core, parent->core);
}
EXPORT_SYMBOL_GPL(clk_has_parent);

diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c
index d1b1372f7aaa..7068517428e2 100644
--- a/drivers/clk/clk_test.c
+++ b/drivers/clk/clk_test.c
@@ -491,8 +491,32 @@ clk_test_multiple_parents_mux_get_parent(struct kunit *test)
clk_put(clk);
}

+/*
+ * Test that for a clock with a multiple parents, clk_has_parent()
+ * actually reports all of them as parents.
+ */
+static void
+clk_test_multiple_parents_mux_has_parent(struct kunit *test)
+{
+ struct clk_multiple_parent_ctx *ctx = test->priv;
+ struct clk_hw *hw = &ctx->hw;
+ struct clk *clk = clk_hw_get_clk(hw, NULL);
+ struct clk *parent;
+
+ parent = clk_hw_get_clk(&ctx->parents_ctx[0].hw, NULL);
+ KUNIT_EXPECT_TRUE(test, clk_has_parent(clk, parent));
+ clk_put(parent);
+
+ parent = clk_hw_get_clk(&ctx->parents_ctx[1].hw, NULL);
+ KUNIT_EXPECT_TRUE(test, clk_has_parent(clk, parent));
+ clk_put(parent);
+
+ clk_put(clk);
+}
+
static struct kunit_case clk_multiple_parents_mux_test_cases[] = {
KUNIT_CASE(clk_test_multiple_parents_mux_get_parent),
+ KUNIT_CASE(clk_test_multiple_parents_mux_has_parent),
{}
};

@@ -918,6 +942,24 @@ clk_test_single_parent_mux_get_parent(struct kunit *test)
clk_put(clk);
}

+/*
+ * Test that for a clock with a single parent, clk_has_parent() actually
+ * reports it as a parent.
+ */
+static void
+clk_test_single_parent_mux_has_parent(struct kunit *test)
+{
+ struct clk_single_parent_ctx *ctx = test->priv;
+ struct clk_hw *hw = &ctx->hw;
+ struct clk *clk = clk_hw_get_clk(hw, NULL);
+ struct clk *parent = clk_hw_get_clk(&ctx->parent_ctx.hw, NULL);
+
+ KUNIT_EXPECT_TRUE(test, clk_has_parent(clk, parent));
+
+ clk_put(parent);
+ clk_put(clk);
+}
+
/*
* Test that for a clock that can't modify its rate and with a single
* parent, if we set disjoints range on the parent and then the child,
@@ -1022,6 +1064,7 @@ clk_test_single_parent_mux_set_range_round_rate_child_smaller(struct kunit *test

static struct kunit_case clk_single_parent_mux_test_cases[] = {
KUNIT_CASE(clk_test_single_parent_mux_get_parent),
+ KUNIT_CASE(clk_test_single_parent_mux_has_parent),
KUNIT_CASE(clk_test_single_parent_mux_set_range_disjoint_child_last),
KUNIT_CASE(clk_test_single_parent_mux_set_range_disjoint_parent_last),
KUNIT_CASE(clk_test_single_parent_mux_set_range_round_rate_child_smaller),
--
2.36.1