drivers: clk: implement clk_is_enabled()

Add clock API function clk_is_enabled(). It is not very useful at
runtime since clock state can change at any time. The API function
is useful during specific system sequences where OP-TEE core knows
is executes atomically (primary core boot, low power sequences).

Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

2 files changed, 15 insertions, 0 deletions

diff --git a/core/drivers/clk/clk.c b/core/drivers/clk/clk.c
index 56cf4d09..0d15095c 100644
--- a/core/drivers/clk/clk.c
+++ b/core/drivers/clk/clk.c
@@ -111,6 +111,11 @@ static bool clk_is_enabled_no_lock(struct clk *clk)
 	return refcount_val(&clk->enabled_count) != 0;
 }
 
+bool clk_is_enabled(struct clk *clk)
+{
+	return clk_is_enabled_no_lock(clk);
+}
+
 static void clk_disable_no_lock(struct clk *clk)
 {
 	struct clk *parent = NULL;
diff --git a/core/include/drivers/clk.h b/core/include/drivers/clk.h
index 73629a43..083a44f0 100644
--- a/core/include/drivers/clk.h
+++ b/core/include/drivers/clk.h
@@ -132,6 +132,16 @@ TEE_Result clk_enable(struct clk *clk);
 void clk_disable(struct clk *clk);
 
 /**
+ * clk_is_enabled - Informative state on the clock
+ *
+ * This function is useful during specific system sequences where core
+ * executes atomically (primary core boot, some low power sequences).
+ *
+ * @clk: Clock refernece
+ */
+bool clk_is_enabled(struct clk *clk);
+
+/**
  * clk_get_parent - Get the current clock parent
  *
  * @clk: Clock for which the parent is needed