Commit 30d6f8c1 authored by Jerome Brunet's avatar Jerome Brunet Committed by Stephen Boyd
Browse files

clk: add api to get clk consumer from clk_hw 



clk_register() is deprecated. Using 'clk' member of struct clk_hw is
discouraged. With this constraint, it is difficult for driver to
register clocks using the clk_hw API and then use the clock with
the consumer API

This adds a simple helper, clk_hw_get_clk(), to get a struct clk from
a struct clk_hw. Like other clk_get() variant, each call to this helper
must be balanced with a call to clk_put(). To make life easier on the
consumers, a memory managed version is provided as well.

Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: default avatarJerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20201021162147.563655-3-jbrunet@baylibre.com


Tested-by: default avatarKevin Hilman <khilman@baylibre.com>
[sboyd@kernel.org: Fix kernel-doc]
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent e5a4b9b9

drivers/clk/clk.c

+61 −0
Original line number Diff line number Diff line
@@ -3667,6 +3667,24 @@ struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw, 
	return clk;

}



/**

 * clk_hw_get_clk - get clk consumer given an clk_hw

 * @hw: clk_hw associated with the clk being consumed

 * @con_id: connection ID string on device

 *

 * Returns: new clk consumer

 * This is the function to be used by providers which need

 * to get a consumer clk and act on the clock element

 * Calls to this function must be balanced with calls clk_put()

 */

struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)

{

	struct device *dev = hw->core->dev;



	return clk_hw_create_clk(dev, hw, dev_name(dev), con_id);

}

EXPORT_SYMBOL(clk_hw_get_clk);



static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)

{

	const char *dst;
@@ -4187,6 +4205,49 @@ void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw) 
}

EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);



static void devm_clk_release(struct device *dev, void *res)

{

	clk_put(*(struct clk **)res);

}



/**

 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()

 * @dev: device that is registering this clock

 * @hw: clk_hw associated with the clk being consumed

 * @con_id: connection ID string on device

 *

 * Managed clk_hw_get_clk(). Clocks got with this function are

 * automatically clk_put() on driver detach. See clk_put()

 * for more information.

 */

struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,

				const char *con_id)

{

	struct clk *clk;

	struct clk **clkp;



	/* This should not happen because it would mean we have drivers

	 * passing around clk_hw pointers instead of having the caller use

	 * proper clk_get() style APIs

	 */

	WARN_ON_ONCE(dev != hw->core->dev);



	clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);

	if (!clkp)

		return ERR_PTR(-ENOMEM);



	clk = clk_hw_get_clk(hw, con_id);

	if (!IS_ERR(clk)) {

		*clkp = clk;

		devres_add(dev, clkp);

	} else {

		devres_free(clkp);

	}



	return clk;

}

EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);



/*

 * clkdev helpers

 */

include/linux/clk-provider.h

+5 −0
Original line number Diff line number Diff line
@@ -1088,6 +1088,11 @@ static inline struct clk_hw *__clk_get_hw(struct clk *clk) 
	return (struct clk_hw *)clk;

}

#endif



struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id);

struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,

				const char *con_id);



unsigned int clk_hw_get_num_parents(const struct clk_hw *hw);

struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw);

struct clk_hw *clk_hw_get_parent_by_index(const struct clk_hw *hw,