diff options
Diffstat (limited to 'include/linux/clk.h')
| -rw-r--r-- | include/linux/clk.h | 218 |
1 files changed, 160 insertions, 58 deletions
diff --git a/include/linux/clk.h b/include/linux/clk.h index b0252726df61..b3ac22d0fc1f 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -12,6 +12,7 @@ #ifndef __LINUX_CLK_H #define __LINUX_CLK_H +#include <linux/err.h> #include <linux/kernel.h> #include <linux/notifier.h> @@ -81,12 +82,49 @@ int clk_notifier_register(struct clk *clk, struct notifier_block *nb); int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb); -#endif /* !CONFIG_COMMON_CLK */ +#endif + +/** + * clk_prepare - prepare a clock source + * @clk: clock source + * + * This prepares the clock source for use. + * + * Must not be called from within atomic context. + */ +#ifdef CONFIG_HAVE_CLK_PREPARE +int clk_prepare(struct clk *clk); +#else +static inline int clk_prepare(struct clk *clk) +{ + might_sleep(); + return 0; +} +#endif + +/** + * clk_unprepare - undo preparation of a clock source + * @clk: clock source + * + * This undoes a previously prepared clock. The caller must balance + * the number of prepare and unprepare calls. + * + * Must not be called from within atomic context. + */ +#ifdef CONFIG_HAVE_CLK_PREPARE +void clk_unprepare(struct clk *clk); +#else +static inline void clk_unprepare(struct clk *clk) +{ + might_sleep(); +} +#endif +#ifdef CONFIG_HAVE_CLK /** * clk_get - lookup and obtain a reference to a clock producer. * @dev: device for clock "consumer" - * @id: clock comsumer ID + * @id: clock consumer ID * * Returns a struct clk corresponding to the clock producer, or * valid IS_ERR() condition containing errno. The implementation @@ -101,22 +139,24 @@ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb); struct clk *clk_get(struct device *dev, const char *id); /** - * clk_prepare - prepare a clock source - * @clk: clock source + * devm_clk_get - lookup and obtain a managed reference to a clock producer. + * @dev: device for clock "consumer" + * @id: clock consumer ID * - * This prepares the clock source for use. + * Returns a struct clk corresponding to the clock producer, or + * valid IS_ERR() condition containing errno. The implementation + * uses @dev and @id to determine the clock consumer, and thereby + * the clock producer. (IOW, @id may be identical strings, but + * clk_get may return different clock producers depending on @dev.) * - * Must not be called from within atomic context. + * Drivers must assume that the clock source is not enabled. + * + * devm_clk_get should not be called from within interrupt context. + * + * The clock will automatically be freed when the device is unbound + * from the bus. */ -#ifdef CONFIG_HAVE_CLK_PREPARE -int clk_prepare(struct clk *clk); -#else -static inline int clk_prepare(struct clk *clk) -{ - might_sleep(); - return 0; -} -#endif +struct clk *devm_clk_get(struct device *dev, const char *id); /** * clk_enable - inform the system when the clock source should be running. @@ -146,47 +186,6 @@ int clk_enable(struct clk *clk); */ void clk_disable(struct clk *clk); - -/** - * clk_unprepare - undo preparation of a clock source - * @clk: clock source - * - * This undoes a previously prepared clock. The caller must balance - * the number of prepare and unprepare calls. - * - * Must not be called from within atomic context. - */ -#ifdef CONFIG_HAVE_CLK_PREPARE -void clk_unprepare(struct clk *clk); -#else -static inline void clk_unprepare(struct clk *clk) -{ - might_sleep(); -} -#endif - -/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */ -static inline int clk_prepare_enable(struct clk *clk) -{ - int ret; - - ret = clk_prepare(clk); - if (ret) - return ret; - ret = clk_enable(clk); - if (ret) - clk_unprepare(clk); - - return ret; -} - -/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */ -static inline void clk_disable_unprepare(struct clk *clk) -{ - clk_disable(clk); - clk_unprepare(clk); -} - /** * clk_get_rate - obtain the current clock rate (in Hz) for a clock source. * This is only valid once the clock source has been enabled. @@ -206,6 +205,18 @@ unsigned long clk_get_rate(struct clk *clk); */ void clk_put(struct clk *clk); +/** + * devm_clk_put - "free" a managed clock source + * @dev: device used to acuqire the clock + * @clk: clock source acquired with devm_clk_get() + * + * Note: drivers must ensure that all clk_enable calls made on this + * clock source are balanced by clk_disable calls prior to calling + * this function. + * + * clk_put should not be called from within interrupt context. + */ +void devm_clk_put(struct device *dev, struct clk *clk); /* * The remaining APIs are optional for machine class support. @@ -220,7 +231,7 @@ void clk_put(struct clk *clk); * Returns rounded clock rate in Hz, or negative errno. */ long clk_round_rate(struct clk *clk, unsigned long rate); - + /** * clk_set_rate - set the clock rate for a clock source * @clk: clock source @@ -229,7 +240,7 @@ long clk_round_rate(struct clk *clk, unsigned long rate); * Returns success (0) or negative errno. */ int clk_set_rate(struct clk *clk, unsigned long rate); - + /** * clk_set_parent - set the parent clock source for this clock * @clk: clock source @@ -265,6 +276,78 @@ struct clk *clk_get_parent(struct clk *clk); */ struct clk *clk_get_sys(const char *dev_id, const char *con_id); +#else /* !CONFIG_HAVE_CLK */ + +static inline struct clk *clk_get(struct device *dev, const char *id) +{ + return NULL; +} + +static inline struct clk *devm_clk_get(struct device *dev, const char *id) +{ + return NULL; +} + +static inline void clk_put(struct clk *clk) {} + +static inline void devm_clk_put(struct device *dev, struct clk *clk) {} + +static inline int clk_enable(struct clk *clk) +{ + return 0; +} + +static inline void clk_disable(struct clk *clk) {} + +static inline unsigned long clk_get_rate(struct clk *clk) +{ + return 0; +} + +static inline int clk_set_rate(struct clk *clk, unsigned long rate) +{ + return 0; +} + +static inline long clk_round_rate(struct clk *clk, unsigned long rate) +{ + return 0; +} + +static inline int clk_set_parent(struct clk *clk, struct clk *parent) +{ + return 0; +} + +static inline struct clk *clk_get_parent(struct clk *clk) +{ + return NULL; +} + +#endif + +/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */ +static inline int clk_prepare_enable(struct clk *clk) +{ + int ret; + + ret = clk_prepare(clk); + if (ret) + return ret; + ret = clk_enable(clk); + if (ret) + clk_unprepare(clk); + + return ret; +} + +/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */ +static inline void clk_disable_unprepare(struct clk *clk) +{ + clk_disable(clk); + clk_unprepare(clk); +} + /** * clk_add_alias - add a new clock alias * @alias: name for clock alias @@ -278,4 +361,23 @@ struct clk *clk_get_sys(const char *dev_id, const char *con_id); int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, struct device *dev); +struct device_node; +struct of_phandle_args; + +#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); +struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec); +#else +static inline struct clk *of_clk_get(struct device_node *np, int index) +{ + return ERR_PTR(-ENOENT); +} +static inline struct clk *of_clk_get_by_name(struct device_node *np, + const char *name) +{ + return ERR_PTR(-ENOENT); +} +#endif + #endif |