Commit 1df4046a authored by Stephen Boyd's avatar Stephen Boyd
Browse files

clk: Combine __clk_get() and __clk_create_clk() 



The __clk_get() function is practically a private clk implementation
detail now. No architecture defines it, and given that new code should
be using the common clk framework there isn't a need for it to keep
existing just to serve clkdev purposes. Let's fold it into the
__clk_create_clk() function and make that a little more generic by
renaming it to clk_hw_create_clk(). This will allow the framework to
create a struct clk handle to a particular clk_hw pointer and link it up
as a consumer wherever that's needed.

Doing this also lets us get rid of the __clk_free_clk() API that had to
be kept in sync with __clk_put(). Splitting that API up into the "link
and unlink from consumer list" phase and "free the clk pointer" phase
allows us to reuse that logic in a couple places, simplifying the code.

Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Jeffrey Hugo <jhugo@codeaurora.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent d1393711

drivers/clk/clk.c

+94 −46
Original line number Diff line number Diff line
@@ -3209,42 +3209,103 @@ unlock: 
	return ret;

}



struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,

/**

 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core

 * @core: clk to add consumer to

 * @clk: consumer to link to a clk

 */

static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)

{

	clk_prepare_lock();

	hlist_add_head(&clk->clks_node, &core->clks);

	clk_prepare_unlock();

}



/**

 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core

 * @clk: consumer to unlink

 */

static void clk_core_unlink_consumer(struct clk *clk)

{

	lockdep_assert_held(&prepare_lock);

	hlist_del(&clk->clks_node);

}



/**

 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core

 * @core: clk to allocate a consumer for

 * @dev_id: string describing device name

 * @con_id: connection ID string on device

 *

 * Returns: clk consumer left unlinked from the consumer list

 */

static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,

			     const char *con_id)

{

	struct clk *clk;



	/* This is to allow this function to be chained to others */

	if (IS_ERR_OR_NULL(hw))

		return ERR_CAST(hw);



	clk = kzalloc(sizeof(*clk), GFP_KERNEL);

	if (!clk)

		return ERR_PTR(-ENOMEM);



	clk->core = hw->core;

	clk->core = core;

	clk->dev_id = dev_id;

	clk->con_id = kstrdup_const(con_id, GFP_KERNEL);

	clk->max_rate = ULONG_MAX;



	clk_prepare_lock();

	hlist_add_head(&clk->clks_node, &hw->core->clks);

	clk_prepare_unlock();



	return clk;

}



/* keep in sync with __clk_put */

void __clk_free_clk(struct clk *clk)

/**

 * free_clk - Free a clk consumer

 * @clk: clk consumer to free

 *

 * Note, this assumes the clk has been unlinked from the clk_core consumer

 * list.

 */

static void free_clk(struct clk *clk)

{

	clk_prepare_lock();

	hlist_del(&clk->clks_node);

	clk_prepare_unlock();



	kfree_const(clk->con_id);

	kfree(clk);

}



/**

 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given

 * a clk_hw

 * @hw: clk_hw associated with the clk being consumed

 * @dev_id: string describing device name

 * @con_id: connection ID string on device

 *

 * This is the main function used to create a clk pointer for use by clk

 * consumers. It connects a consumer to the clk_core and clk_hw structures

 * used by the framework and clk provider respectively.

 */

struct clk *clk_hw_create_clk(struct clk_hw *hw,

			      const char *dev_id, const char *con_id)

{

	struct clk *clk;

	struct clk_core *core;



	/* This is to allow this function to be chained to others */

	if (IS_ERR_OR_NULL(hw))

		return ERR_CAST(hw);



	core = hw->core;

	clk = alloc_clk(core, dev_id, con_id);

	if (IS_ERR(clk))

		return clk;



	if (!try_module_get(core->owner)) {

		free_clk(clk);

		return ERR_PTR(-ENOENT);

	}



	kref_get(&core->ref);

	clk_core_link_consumer(core, clk);



	return clk;

}



/**

 * clk_register - allocate a new clock, register it and return an opaque cookie

 * @dev: device that is registering this clock
@@ -3320,17 +3381,27 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) 


	INIT_HLIST_HEAD(&core->clks);



	hw->clk = __clk_create_clk(hw, NULL, NULL);

	/*

	 * Don't call clk_hw_create_clk() here because that would pin the

	 * provider module to itself and prevent it from ever being removed.

	 */

	hw->clk = alloc_clk(core, NULL, NULL);

	if (IS_ERR(hw->clk)) {

		ret = PTR_ERR(hw->clk);

		goto fail_parents;

	}



	clk_core_link_consumer(hw->core, hw->clk);



	ret = __clk_core_init(core);

	if (!ret)

		return hw->clk;



	__clk_free_clk(hw->clk);

	clk_prepare_lock();

	clk_core_unlink_consumer(hw->clk);

	clk_prepare_unlock();



	free_clk(hw->clk);

	hw->clk = NULL;



fail_parents:
@@ -3601,20 +3672,7 @@ EXPORT_SYMBOL_GPL(devm_clk_hw_unregister); 
/*

 * clkdev helpers

 */

int __clk_get(struct clk *clk)

{

	struct clk_core *core = !clk ? NULL : clk->core;



	if (core) {

		if (!try_module_get(core->owner))

			return 0;



		kref_get(&core->ref);

	}

	return 1;

}



/* keep in sync with __clk_free_clk */

void __clk_put(struct clk *clk)

{

	struct module *owner;
@@ -3648,8 +3706,7 @@ void __clk_put(struct clk *clk) 


	module_put(owner);



	kfree_const(clk->con_id);

	kfree(clk);

	free_clk(clk);

}



/***        clk rate change notifiers        ***/
@@ -4025,8 +4082,7 @@ struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec, 
				       const char *dev_id, const char *con_id)

{

	struct of_clk_provider *provider;

	struct clk *clk = ERR_PTR(-EPROBE_DEFER);

	struct clk_hw *hw;

	struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);



	if (!clkspec)

		return ERR_PTR(-EINVAL);
@@ -4036,21 +4092,13 @@ struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec, 
	list_for_each_entry(provider, &of_clk_providers, link) {

		if (provider->node == clkspec->np) {

			hw = __of_clk_get_hw_from_provider(provider, clkspec);

			clk = __clk_create_clk(hw, dev_id, con_id);

		}



		if (!IS_ERR(clk)) {

			if (!__clk_get(clk)) {

				__clk_free_clk(clk);

				clk = ERR_PTR(-ENOENT);

			}



			if (!IS_ERR(hw))

				break;

		}

	}

	mutex_unlock(&of_clk_mutex);



	return clk;

	return clk_hw_create_clk(hw, dev_id, con_id);

}



/**

drivers/clk/clk.h

+3 −7
Original line number Diff line number Diff line
@@ -12,24 +12,20 @@ struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec, 
#endif



#ifdef CONFIG_COMMON_CLK

struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,

			     const char *con_id);

void __clk_free_clk(struct clk *clk);

int __clk_get(struct clk *clk);

struct clk *clk_hw_create_clk(struct clk_hw *hw,

			      const char *dev_id, const char *con_id);

void __clk_put(struct clk *clk);

#else

/* All these casts to avoid ifdefs in clkdev... */

static inline struct clk *

__clk_create_clk(struct clk_hw *hw, const char *dev_id, const char *con_id)

clk_hw_create_clk(struct clk_hw *hw, const char *dev_id, const char *con_id)

{

	return (struct clk *)hw;

}

static inline void __clk_free_clk(struct clk *clk) { }

static struct clk_hw *__clk_get_hw(struct clk *clk)

{

	return (struct clk_hw *)clk;

}

static inline int __clk_get(struct clk *clk) { return 1; }

static inline void __clk_put(struct clk *clk) { }



#endif

drivers/clk/clkdev.c

+1 −8
Original line number Diff line number Diff line
@@ -174,16 +174,9 @@ struct clk *clk_get_sys(const char *dev_id, const char *con_id) 
	if (!cl)

		goto out;



	clk = __clk_create_clk(cl->clk_hw, dev_id, con_id);

	clk = clk_hw_create_clk(cl->clk_hw, dev_id, con_id);

	if (IS_ERR(clk))

		goto out;



	if (!__clk_get(clk)) {

		__clk_free_clk(clk);

		cl = NULL;

		goto out;

	}



out:

	mutex_unlock(&clocks_mutex);

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