From 0a4807c2f9a4a1afc2163089176abdc7ee4a361a Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Wed, 14 Oct 2015 14:03:07 -0700 Subject: [PATCH] clk: Make of_clk_get_parent_name() robust with #clock-cells = 1 If a clock provider has #clock-cells = 1 and we call of_clk_get_parent_name() on it we may end up returning the name of the provider node if the provider doesn't have a clock-output-names property. This doesn't make sense, especially when you consider that calling of_clk_get_parent_name() on such a node with different indices will return the same name each time. Let's try getting the clock from the framework via of_clk_get() instead, and only fallback to the node name if we have a provider with #clock-cells = 0. This way, we can't hand out the same name for different clocks when we don't actually know their names. Cc: Thomas Petazzoni Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index b005f666e3a1..a0fe9ca1f0af 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -3055,6 +3055,7 @@ const char *of_clk_get_parent_name(struct device_node *np, int index) u32 pv; int rc; int count; + struct clk *clk; if (index < 0) return NULL; @@ -3080,8 +3081,25 @@ const char *of_clk_get_parent_name(struct device_node *np, int index) if (of_property_read_string_index(clkspec.np, "clock-output-names", index, - &clk_name) < 0) - clk_name = clkspec.np->name; + &clk_name) < 0) { + /* + * Best effort to get the name if the clock has been + * registered with the framework. If the clock isn't + * registered, we return the node name as the name of + * the clock as long as #clock-cells = 0. + */ + clk = of_clk_get_from_provider(&clkspec); + if (IS_ERR(clk)) { + if (clkspec.args_count == 0) + clk_name = clkspec.np->name; + else + clk_name = NULL; + } else { + clk_name = __clk_get_name(clk); + clk_put(clk); + } + } + of_node_put(clkspec.np); return clk_name; -- 2.20.1