clk: Introduce clk_has_parent() (4e88f3de) · Commits · 戴 / test

drivers/clk/clk.c

+30 −0

Original line number	Diff line number	Diff line
		@@ -1651,6 +1651,36 @@ void __clk_reparent(struct clk clk, struct clk new_parent)
		__clk_recalc_rates(clk, POST_RATE_CHANGE);
		}

		/**
		* clk_has_parent - check if a clock is a possible parent for another
		* @clk: clock source
		* @parent: parent clock source
		*
		* This function can be used in drivers that need to check that a clock can be
		* the parent of another without actually changing the parent.
		*
		* Returns true if @parent is a possible parent for @clk, false otherwise.
		*/
		bool clk_has_parent(struct clk clk, struct clk parent)
		{
		unsigned int i;

		/* NULL clocks should be nops, so return success if either is NULL. */
		if (!clk \|\| !parent)
		return true;

		/* Optimize for the case where the parent is already the parent. */
		if (clk->parent == parent)
		return true;

		for (i = 0; i < clk->num_parents; i++)
		if (strcmp(clk->parent_names[i], parent->name) == 0)
		return true;

		return false;
		}
		EXPORT_SYMBOL_GPL(clk_has_parent);

		/**
		* clk_set_parent - switch the parent of a mux clk
		* @clk: the mux clk whose input we are switching

+17 −0

Original line number	Diff line number	Diff line
		@@ -301,6 +301,18 @@ long clk_round_rate(struct clk *clk, unsigned long rate);
		*/
		int clk_set_rate(struct clk *clk, unsigned long rate);

		/**
		* clk_has_parent - check if a clock is a possible parent for another
		* @clk: clock source
		* @parent: parent clock source
		*
		* This function can be used in drivers that need to check that a clock can be
		* the parent of another without actually changing the parent.
		*
		* Returns true if @parent is a possible parent for @clk, false otherwise.
		*/
		bool clk_has_parent(struct clk clk, struct clk parent);

		/**
		* clk_set_parent - set the parent clock source for this clock
		* @clk: clock source
		@@ -374,6 +386,11 @@ static inline long clk_round_rate(struct clk *clk, unsigned long rate)
		return 0;
		}

		static inline bool clk_has_parent(struct clk clk, struct clk parent)
		{
		return true;
		}

		static inline int clk_set_parent(struct clk clk, struct clk parent)
		{
		return 0;