clk: add support for clk_is_match()

Add support for clk_is_match() which is required to
know if two clock pointers point to the same exact
physical clock.

Also add a unit test for the new API.

Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

drivers/clk/clk-uclass.c

@@ -518,6 +518,19 @@ int clk_get_by_id(ulong id, struct clk **clkp)
 	return -ENOENT;
 }
 
+bool clk_is_match(const struct clk *p, const struct clk *q)
+{
+	/* trivial case: identical struct clk's or both NULL */
+	if (p == q)
+		return true;
+
+	/* same device, id and data */
+	if (p->dev == q->dev && p->id == q->id && p->data == q->data)
+		return true;
+
+	return false;
+}
+
 UCLASS_DRIVER(clk) = {
 	.id		= UCLASS_CLK,
 	.name		= "clk",

include/clk.h

@@ -333,6 +333,18 @@ int clk_disable(struct clk *clk);
  */
 int clk_disable_bulk(struct clk_bulk *bulk);
 
+/**
+ * clk_is_match - check if two clk's point to the same hardware clock
+ * @p: clk compared against q
+ * @q: clk compared against p
+ *
+ * Returns true if the two struct clk pointers both point to the same hardware
+ * clock node.
+ *
+ * Returns false otherwise. Note that two NULL clks are treated as matching.
+ */
+bool clk_is_match(const struct clk *p, const struct clk *q);
+
 int soc_clk_dump(void);
 
 /**

test/dm/clk.c

@@ -24,6 +24,7 @@ static int dm_test_clk_base(struct unit_test_state *uts)
 	/* Get the same clk port in 2 different ways and compare */
 	ut_assertok(clk_get_by_index(dev, 1, &clk_method1));
 	ut_assertok(clk_get_by_index_nodev(dev_ofnode(dev), 1, &clk_method2));
+	ut_asserteq(clk_is_match(&clk_method1, &clk_method2), true);
 	ut_asserteq(clk_method1.id, clk_method2.id);
 
 	return 0;