clkdev: Move clk creation outside of 'clocks_mutex'

We don't need to hold the 'clocks_mutex' here when we're creating a clk
pointer from a clk_lookup structure. Instead, we just need to make sure
that the lookup doesn't go away while we dereference the lookup pointer
to extract the clk_hw pointer out of it. Let's move things around
slightly so that we have a new function to get the clk_hw out of the
lookup with the right locking and then chain the two together for what
used to be __clk_get_sys().

Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Jeffrey Hugo <jhugo@codeaurora.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Tested-by: Jeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/clkdev.c

@@ -72,25 +72,26 @@ static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
 	return cl;
 }
 
-static struct clk *__clk_get_sys(struct device *dev, const char *dev_id,
-				 const char *con_id)
+static struct clk_hw *clk_find_hw(const char *dev_id, const char *con_id)
 {
 	struct clk_lookup *cl;
-	struct clk *clk = NULL;
+	struct clk_hw *hw = ERR_PTR(-ENOENT);
 
 	mutex_lock(&clocks_mutex);
-
 	cl = clk_find(dev_id, con_id);
-	if (!cl)
-		goto out;
-
-	clk = clk_hw_create_clk(dev, cl->clk_hw, dev_id, con_id);
-	if (IS_ERR(clk))
-		cl = NULL;
-out:
+	if (cl)
+		hw = cl->clk_hw;
 	mutex_unlock(&clocks_mutex);
 
-	return cl ? clk : ERR_PTR(-ENOENT);
+	return hw;
+}
+
+static struct clk *__clk_get_sys(struct device *dev, const char *dev_id,
+				 const char *con_id)
+{
+	struct clk_hw *hw = clk_find_hw(dev_id, con_id);
+
+	return clk_hw_create_clk(dev, hw, dev_id, con_id);
 }
 
 struct clk *clk_get_sys(const char *dev_id, const char *con_id)