clk: Add (devm_)clk_get_optional() functions

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: Phil Edworthy <phil.edworthy@renesas.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Russell King <linux@armlinux.org.uk>
[sboyd@kernel.org: Document in devres.txt]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
This commit is contained in:
Phil Edworthy 2018-12-03 11:13:09 +00:00 committed by Stephen Boyd
parent 5c56dfe63b
commit 60b8f0ddf1
3 changed files with 48 additions and 0 deletions

View File

@ -242,6 +242,7 @@ 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()

View File

@ -29,6 +29,17 @@ 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;

View File

@ -383,6 +383,17 @@ int __must_check devm_clk_bulk_get_all(struct device *dev,
*/
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.
@ -718,6 +729,12 @@ 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)
{
@ -862,6 +879,25 @@ 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);