[PATCH 1/9] clk: Keep enable count consistent over reparent

[Sascha Hauer]

When reparenting a clock we have to make sure the new parent is enabled
when the clock was enabled on the old parent. Also we have to decrease
the old parents use counter when the clock was enabled.

Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
 drivers/clk/clk.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 1566beabd..6f3053727 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -173,14 +173,15 @@ struct clk *clk_lookup(const char *name)
 	return ERR_PTR(-ENODEV);
 }
 
-int clk_set_parent(struct clk *clk, struct clk *parent)
+int clk_set_parent(struct clk *clk, struct clk *newparent)
 {
-	int i;
+	int i, ret;
+	struct clk *curparent = clk_get_parent(clk);
 
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);
-	if (IS_ERR(parent))
-		return PTR_ERR(parent);
+	if (IS_ERR(newparent))
+		return PTR_ERR(newparent);
 
 	if (!clk->num_parents)
 		return -EINVAL;
@@ -192,14 +193,22 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
 			clk->parents[i] = clk_lookup(clk->parent_names[i]);
 
 		if (!IS_ERR_OR_NULL(clk->parents[i]))
-			if (clk->parents[i] == parent)
+			if (clk->parents[i] == newparent)
 				break;
 	}
 
 	if (i == clk->num_parents)
 		return -EINVAL;
 
-	return clk->ops->set_parent(clk, i);
+	if (clk->enable_count)
+		clk_enable(newparent);
+
+	ret = clk->ops->set_parent(clk, i);
+
+	if (clk->enable_count)
+		clk_disable(curparent);
+
+	return ret;
 }
 
 struct clk *clk_get_parent(struct clk *clk)
-- 
2.11.0