Commit 46c8773a authored by Stephen Boyd's avatar Stephen Boyd Committed by Mike Turquette
Browse files

clk: Add devm_clk_{register,unregister}() 



Some clock drivers can be simplified if devres takes care of
unregistering any registered clocks along error paths. Introduce
devm_clk_register() so that clock drivers get unregistration for
free along with simplified error paths.

Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: default avatarMike Turquette <mturquette@linaro.org>
parent 980f58a4

drivers/clk/clk.c

+90 −21
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/list.h>

#include <linux/slab.h>

#include <linux/of.h>

#include <linux/device.h>



static DEFINE_SPINLOCK(enable_lock);

static DEFINE_MUTEX(prepare_lock);
@@ -1361,28 +1362,9 @@ struct clk *__clk_register(struct device *dev, struct clk_hw *hw) 
}

EXPORT_SYMBOL_GPL(__clk_register);



/**

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

 * @dev: device that is registering this clock

 * @hw: link to hardware-specific clock data

 *

 * clk_register is the primary interface for populating the clock tree with new

 * clock nodes.  It returns a pointer to the newly allocated struct clk which

 * cannot be dereferenced by driver code but may be used in conjuction with the

 * rest of the clock API.  In the event of an error clk_register will return an

 * error code; drivers must test for an error code after calling clk_register.

 */

struct clk *clk_register(struct device *dev, struct clk_hw *hw)

static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk)

{

	int i, ret;

	struct clk *clk;



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

	if (!clk) {

		pr_err("%s: could not allocate clk\n", __func__);

		ret = -ENOMEM;

		goto fail_out;

	}



	clk->name = kstrdup(hw->init->name, GFP_KERNEL);

	if (!clk->name) {
@@ -1420,7 +1402,7 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw) 


	ret = __clk_init(dev, clk);

	if (!ret)

		return clk;

		return 0;



fail_parent_names_copy:

	while (--i >= 0)
@@ -1429,6 +1411,36 @@ fail_parent_names_copy: 
fail_parent_names:

	kfree(clk->name);

fail_name:

	return ret;

}



/**

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

 * @dev: device that is registering this clock

 * @hw: link to hardware-specific clock data

 *

 * clk_register is the primary interface for populating the clock tree with new

 * clock nodes.  It returns a pointer to the newly allocated struct clk which

 * cannot be dereferenced by driver code but may be used in conjuction with the

 * rest of the clock API.  In the event of an error clk_register will return an

 * error code; drivers must test for an error code after calling clk_register.

 */

struct clk *clk_register(struct device *dev, struct clk_hw *hw)

{

	int ret;

	struct clk *clk;



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

	if (!clk) {

		pr_err("%s: could not allocate clk\n", __func__);

		ret = -ENOMEM;

		goto fail_out;

	}



	ret = _clk_register(dev, hw, clk);

	if (!ret)

		return clk;



	kfree(clk);

fail_out:

	return ERR_PTR(ret);
@@ -1444,6 +1456,63 @@ EXPORT_SYMBOL_GPL(clk_register); 
void clk_unregister(struct clk *clk) {}

EXPORT_SYMBOL_GPL(clk_unregister);



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

{

	clk_unregister(res);

}



/**

 * devm_clk_register - resource managed clk_register()

 * @dev: device that is registering this clock

 * @hw: link to hardware-specific clock data

 *

 * Managed clk_register(). Clocks returned from this function are

 * automatically clk_unregister()ed on driver detach. See clk_register() for

 * more information.

 */

struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)

{

	struct clk *clk;

	int ret;



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

	if (!clk)

		return ERR_PTR(-ENOMEM);



	ret = _clk_register(dev, hw, clk);

	if (!ret) {

		devres_add(dev, clk);

	} else {

		devres_free(clk);

		clk = ERR_PTR(ret);

	}



	return clk;

}

EXPORT_SYMBOL_GPL(devm_clk_register);



static int devm_clk_match(struct device *dev, void *res, void *data)

{

	struct clk *c = res;

	if (WARN_ON(!c))

		return 0;

	return c == data;

}



/**

 * devm_clk_unregister - resource managed clk_unregister()

 * @clk: clock to unregister

 *

 * Deallocate a clock allocated with devm_clk_register(). Normally

 * this function will not need to be called and the resource management

 * code will ensure that the resource is freed.

 */

void devm_clk_unregister(struct device *dev, struct clk *clk)

{

	WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));

}

EXPORT_SYMBOL_GPL(devm_clk_unregister);



/***        clk rate change notifiers        ***/



/**

include/linux/clk-provider.h

+2 −0
Original line number Diff line number Diff line
@@ -331,8 +331,10 @@ struct clk *clk_register_fixed_factor(struct device *dev, const char *name, 
 * error code; drivers must test for an error code after calling clk_register.

 */

struct clk *clk_register(struct device *dev, struct clk_hw *hw);

struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw);



void clk_unregister(struct clk *clk);

void devm_clk_unregister(struct device *dev, struct clk *clk);



/* helper functions */

const char *__clk_get_name(struct clk *clk);

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