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

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

drivers/clk/clk.c

+20 −2
Original line number Diff line number Diff line
@@ -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) < 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;