[PATCH] clk: have clk_get always return -ENOENT on missing clock

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

Currently, clk_get(dev, NULL) returns -ENOENT on missing clock, but 
clk_get(dev, "missing-named-clock") returns -EINVAL. This went by unnoticed
so far as most consumers either require a clock or don't, but with the
addition of clk_get_optional, it's important that clk_get() return value
is uniform.

Therefore align clk_get with Linux and always fall through to clk_get_sys()
if getting clock over DT is not possible. Failing clk_get_sys() returns
-ENOENT always, ensuring we can't end up with -EINVAL as before while
keeping of_clk_get_by_name return value as it is under Linux.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
Please order before commit ("clk: implement clk_get_optional helper")
currently 8b013ac8ec69 in next.
---
 drivers/clk/clkdev.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index 68c6ac36a0c8..dbe998b6af35 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -176,9 +176,9 @@ struct clk *clk_get(struct device *dev, const char *con_id)
 	if (!IS_ERR(clk))
 		return clk;
 
-	if (dev) {
+	if (dev && dev->of_node) {
 		clk = of_clk_get_by_name(dev->of_node, con_id);
-		if (!IS_ERR(clk) || PTR_ERR(clk) != -ENOENT)
+		if (!IS_ERR(clk) || PTR_ERR(clk) == -EPROBE_DEFER)
 			return clk;
 	}
 
-- 
2.39.2