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Commit f8f35358 authored by Phil Edworthy's avatar Phil Edworthy Committed by Greg Kroah-Hartman
Browse files

clk: Add (devm_)clk_get_optional() functions 



[ Upstream commit 60b8f0ddf1a927ef02141a6610fd52575134f821 ]

This adds clk_get_optional() and devm_clk_get_optional() functions to get
optional clocks.

They behave the same as (devm_)clk_get() except where there is no clock
producer. In this case, instead of returning -ENOENT, the function
returns NULL. This makes error checking simpler and allows
clk_prepare_enable, etc to be called on the returned reference
without additional checks.

Signed-off-by: default avatarPhil Edworthy <phil.edworthy@renesas.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Russell King <linux@armlinux.org.uk>
[sboyd@kernel.org: Document in devres.txt]
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
Stable-dep-of: a6191a3d1811 ("gpio: aspeed: Use devm_clk api to manage clock source")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 8c4d52b8

Documentation/driver-model/devres.txt

+1 −0
Original line number Diff line number Diff line
@@ -235,6 +235,7 @@ certainly invest a bit more effort into libata core layer). 


CLOCK

  devm_clk_get()

  devm_clk_get_optional()

  devm_clk_put()

  devm_clk_hw_register()

  devm_of_clk_add_hw_provider()

drivers/clk/clk-devres.c

+11 −0
Original line number Diff line number Diff line
@@ -34,6 +34,17 @@ struct clk *devm_clk_get(struct device *dev, const char *id) 
}

EXPORT_SYMBOL(devm_clk_get);



struct clk *devm_clk_get_optional(struct device *dev, const char *id)

{

	struct clk *clk = devm_clk_get(dev, id);



	if (clk == ERR_PTR(-ENOENT))

		return NULL;



	return clk;

}

EXPORT_SYMBOL(devm_clk_get_optional);



struct clk_bulk_devres {

	struct clk_bulk_data *clks;

	int num_clks;

include/linux/clk.h

+36 −0
Original line number Diff line number Diff line
@@ -388,6 +388,17 @@ int __must_check devm_clk_bulk_get(struct device *dev, int num_clks, 
 */

struct clk *devm_clk_get(struct device *dev, const char *id);



/**

 * devm_clk_get_optional - lookup and obtain a managed reference to an optional

 *			   clock producer.

 * @dev: device for clock "consumer"

 * @id: clock consumer ID

 *

 * Behaves the same as devm_clk_get() except where there is no clock producer.

 * In this case, instead of returning -ENOENT, the function returns NULL.

 */

struct clk *devm_clk_get_optional(struct device *dev, const char *id);



/**

 * devm_get_clk_from_child - lookup and obtain a managed reference to a

 *			     clock producer from child node.
@@ -655,6 +666,12 @@ static inline struct clk *devm_clk_get(struct device *dev, const char *id) 
	return NULL;

}



static inline struct clk *devm_clk_get_optional(struct device *dev,

						const char *id)

{

	return NULL;

}



static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks,

						 struct clk_bulk_data *clks)

{
@@ -774,6 +791,25 @@ static inline void clk_bulk_disable_unprepare(int num_clks, 
	clk_bulk_unprepare(num_clks, clks);

}



/**

 * clk_get_optional - lookup and obtain a reference to an optional clock

 *		      producer.

 * @dev: device for clock "consumer"

 * @id: clock consumer ID

 *

 * Behaves the same as clk_get() except where there is no clock producer. In

 * this case, instead of returning -ENOENT, the function returns NULL.

 */

static inline struct clk *clk_get_optional(struct device *dev, const char *id)

{

	struct clk *clk = clk_get(dev, id);



	if (clk == ERR_PTR(-ENOENT))

		return NULL;



	return clk;

}



#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)

struct clk *of_clk_get(struct device_node *np, int index);

struct clk *of_clk_get_by_name(struct device_node *np, const char *name);