Commit 0a4807c2 authored by Stephen Boyd's avatar Stephen Boyd

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 <thomas.petazzoni@free-electrons.com>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 087a920d
......@@ -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;
......
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