diff options
Diffstat (limited to 'include/linux/clk.h')
| -rw-r--r-- | include/linux/clk.h | 347 |
1 files changed, 297 insertions, 50 deletions
diff --git a/include/linux/clk.h b/include/linux/clk.h index 7fd6a1febcf4..b607482ca77e 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -92,7 +92,7 @@ struct clk_bulk_data { #ifdef CONFIG_COMMON_CLK /** - * clk_notifier_register: register a clock rate-change notifier callback + * clk_notifier_register - register a clock rate-change notifier callback * @clk: clock whose rate we are interested in * @nb: notifier block with callback function pointer * @@ -103,13 +103,24 @@ struct clk_bulk_data { int clk_notifier_register(struct clk *clk, struct notifier_block *nb); /** - * clk_notifier_unregister: unregister a clock rate-change notifier callback + * clk_notifier_unregister - unregister a clock rate-change notifier callback * @clk: clock whose rate we are no longer interested in * @nb: notifier block which will be unregistered */ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb); /** + * devm_clk_notifier_register - register a managed rate-change notifier callback + * @dev: device for clock "consumer" + * @clk: clock whose rate we are interested in + * @nb: notifier block with callback function pointer + * + * Returns 0 on success, -EERROR otherwise + */ +int devm_clk_notifier_register(struct device *dev, struct clk *clk, + struct notifier_block *nb); + +/** * clk_get_accuracy - obtain the clock accuracy in ppb (parts per billion) * for a clock source. * @clk: clock source @@ -150,7 +161,7 @@ int clk_get_phase(struct clk *clk); int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den); /** - * clk_get_duty_cycle - return the duty cycle ratio of a clock signal + * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal * @clk: clock signal source * @scale: scaling factor to be applied to represent the ratio as an integer * @@ -172,6 +183,51 @@ int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale); */ bool clk_is_match(const struct clk *p, const struct clk *q); +/** + * clk_rate_exclusive_get - get exclusivity over the rate control of a + * producer + * @clk: clock source + * + * This function allows drivers to get exclusive control over the rate of a + * provider. It prevents any other consumer to execute, even indirectly, + * opereation which could alter the rate of the provider or cause glitches + * + * If exlusivity is claimed more than once on clock, even by the same driver, + * the rate effectively gets locked as exclusivity can't be preempted. + * + * Must not be called from within atomic context. + * + * Returns success (0) or negative errno. + */ +int clk_rate_exclusive_get(struct clk *clk); + +/** + * devm_clk_rate_exclusive_get - devm variant of clk_rate_exclusive_get + * @dev: device the exclusivity is bound to + * @clk: clock source + * + * Calls clk_rate_exclusive_get() on @clk and registers a devm cleanup handler + * on @dev to call clk_rate_exclusive_put(). + * + * Must not be called from within atomic context. + */ +int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk); + +/** + * clk_rate_exclusive_put - release exclusivity over the rate control of a + * producer + * @clk: clock source + * + * This function allows drivers to release the exclusivity it previously got + * from clk_rate_exclusive_get() + * + * The caller must balance the number of clk_rate_exclusive_get() and + * clk_rate_exclusive_put() calls. + * + * Must not be called from within atomic context. + */ +void clk_rate_exclusive_put(struct clk *clk); + #else static inline int clk_notifier_register(struct clk *clk, @@ -186,6 +242,13 @@ static inline int clk_notifier_unregister(struct clk *clk, return -ENOTSUPP; } +static inline int devm_clk_notifier_register(struct device *dev, + struct clk *clk, + struct notifier_block *nb) +{ + return -ENOTSUPP; +} + static inline long clk_get_accuracy(struct clk *clk) { return -ENOTSUPP; @@ -218,8 +281,21 @@ static inline bool clk_is_match(const struct clk *p, const struct clk *q) return p == q; } +static inline int clk_rate_exclusive_get(struct clk *clk) +{ + return 0; +} + +static inline int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk) +{ + return 0; +} + +static inline void clk_rate_exclusive_put(struct clk *clk) {} + #endif +#ifdef CONFIG_HAVE_CLK_PREPARE /** * clk_prepare - prepare a clock source * @clk: clock source @@ -228,10 +304,26 @@ static inline bool clk_is_match(const struct clk *p, const struct clk *q) * * Must not be called from within atomic context. */ -#ifdef CONFIG_HAVE_CLK_PREPARE int clk_prepare(struct clk *clk); int __must_check clk_bulk_prepare(int num_clks, const struct clk_bulk_data *clks); + +/** + * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it. + * @clk: clock source + * + * Returns true if clk_prepare() implicitly enables the clock, effectively + * making clk_enable()/clk_disable() no-ops, false otherwise. + * + * This is of interest mainly to the power management code where actually + * disabling the clock also requires unpreparing it to have any material + * effect. + * + * Regardless of the value returned here, the caller must always invoke + * clk_enable() or clk_prepare_enable() and counterparts for usage counts + * to be right. + */ +bool clk_is_enabled_when_prepared(struct clk *clk); #else static inline int clk_prepare(struct clk *clk) { @@ -245,6 +337,11 @@ clk_bulk_prepare(int num_clks, const struct clk_bulk_data *clks) might_sleep(); return 0; } + +static inline bool clk_is_enabled_when_prepared(struct clk *clk) +{ + return false; +} #endif /** @@ -399,19 +496,38 @@ int __must_check devm_clk_bulk_get_all(struct device *dev, struct clk_bulk_data **clks); /** + * devm_clk_bulk_get_all_enabled - Get and enable all clocks of the consumer (managed) + * @dev: device for clock "consumer" + * @clks: pointer to the clk_bulk_data table of consumer + * + * Returns a positive value for the number of clocks obtained while the + * clock references are stored in the clk_bulk_data table in @clks field. + * Returns 0 if there're none and a negative value if something failed. + * + * This helper function allows drivers to get all clocks of the + * consumer and enables them in one operation with management. + * The clks will automatically be disabled and freed when the device + * is unbound. + */ + +int __must_check devm_clk_bulk_get_all_enabled(struct device *dev, + struct clk_bulk_data **clks); + +/** * devm_clk_get - lookup and obtain a managed reference to a clock producer. * @dev: device for clock "consumer" * @id: clock consumer ID * - * Returns a struct clk corresponding to the clock producer, or + * Context: May sleep. + * + * Return: 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.) * - * Drivers must assume that the clock source is not enabled. - * - * devm_clk_get should not be called from within interrupt context. + * Drivers must assume that the clock source is neither prepared nor + * enabled. * * The clock will automatically be freed when the device is unbound * from the bus. @@ -419,64 +535,155 @@ 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_prepared - devm_clk_get() + clk_prepare() + * @dev: device for clock "consumer" + * @id: clock consumer ID + * + * Context: May sleep. + * + * Return: 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.) + * + * The returned clk (if valid) is prepared. Drivers must however assume + * that the clock is not enabled. + * + * The clock will automatically be unprepared and freed when the device + * is unbound from the bus. + */ +struct clk *devm_clk_get_prepared(struct device *dev, const char *id); + +/** + * devm_clk_get_enabled - devm_clk_get() + clk_prepare_enable() + * @dev: device for clock "consumer" + * @id: clock consumer ID + * + * Context: May sleep. + * + * Return: 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.) + * + * The returned clk (if valid) is prepared and enabled. + * + * The clock will automatically be disabled, unprepared and freed + * when the device is unbound from the bus. + */ +struct clk *devm_clk_get_enabled(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. + * Context: May sleep. + * + * Return: 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. If no such clk is found, it returns NULL + * which serves as a dummy clk. That's the only difference compared + * to devm_clk_get(). + * + * Drivers must assume that the clock source is neither prepared nor + * enabled. + * + * The clock will automatically be freed when the device is unbound + * from the bus. */ 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. + * devm_clk_get_optional_prepared - devm_clk_get_optional() + clk_prepare() * @dev: device for clock "consumer" - * @np: pointer to clock consumer node - * @con_id: clock consumer ID + * @id: clock consumer ID * - * This function parses the clocks, and uses them to look up the - * struct clk from the registered list of clock providers by using - * @np and @con_id + * Context: May sleep. * - * The clock will automatically be freed when the device is unbound - * from the bus. + * Return: 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. If no such clk is found, it returns NULL + * which serves as a dummy clk. That's the only difference compared + * to devm_clk_get_prepared(). + * + * The returned clk (if valid) is prepared. Drivers must however + * assume that the clock is not enabled. + * + * The clock will automatically be unprepared and freed when the + * device is unbound from the bus. */ -struct clk *devm_get_clk_from_child(struct device *dev, - struct device_node *np, const char *con_id); +struct clk *devm_clk_get_optional_prepared(struct device *dev, const char *id); + /** - * clk_rate_exclusive_get - get exclusivity over the rate control of a - * producer - * @clk: clock source + * devm_clk_get_optional_enabled - devm_clk_get_optional() + + * clk_prepare_enable() + * @dev: device for clock "consumer" + * @id: clock consumer ID * - * This function allows drivers to get exclusive control over the rate of a - * provider. It prevents any other consumer to execute, even indirectly, - * opereation which could alter the rate of the provider or cause glitches + * Context: May sleep. * - * If exlusivity is claimed more than once on clock, even by the same driver, - * the rate effectively gets locked as exclusivity can't be preempted. + * Return: 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. If no such clk is found, it returns NULL + * which serves as a dummy clk. That's the only difference compared + * to devm_clk_get_enabled(). * - * Must not be called from within atomic context. + * The returned clk (if valid) is prepared and enabled. * - * Returns success (0) or negative errno. + * The clock will automatically be disabled, unprepared and freed + * when the device is unbound from the bus. */ -int clk_rate_exclusive_get(struct clk *clk); +struct clk *devm_clk_get_optional_enabled(struct device *dev, const char *id); /** - * clk_rate_exclusive_put - release exclusivity over the rate control of a - * producer - * @clk: clock source + * devm_clk_get_optional_enabled_with_rate - devm_clk_get_optional() + + * clk_set_rate() + + * clk_prepare_enable() + * @dev: device for clock "consumer" + * @id: clock consumer ID + * @rate: new clock rate * - * This function allows drivers to release the exclusivity it previously got - * from clk_rate_exclusive_get() + * Context: May sleep. * - * The caller must balance the number of clk_rate_exclusive_get() and - * clk_rate_exclusive_put() calls. + * Return: 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. If no such clk is found, it returns NULL + * which serves as a dummy clk. That's the only difference compared + * to devm_clk_get_enabled(). * - * Must not be called from within atomic context. + * The returned clk (if valid) is prepared and enabled and rate was set. + * + * The clock will automatically be disabled, unprepared and freed + * when the device is unbound from the bus. */ -void clk_rate_exclusive_put(struct clk *clk); +struct clk *devm_clk_get_optional_enabled_with_rate(struct device *dev, + const char *id, + unsigned long rate); + +/** + * devm_get_clk_from_child - lookup and obtain a managed reference to a + * clock producer from child node. + * @dev: device for clock "consumer" + * @np: pointer to clock consumer node + * @con_id: clock consumer ID + * + * This function parses the clocks, and uses them to look up the + * struct clk from the registered list of clock providers by using + * @np and @con_id + * + * The clock will automatically be freed when the device is unbound + * from the bus. + */ +struct clk *devm_get_clk_from_child(struct device *dev, + struct device_node *np, const char *con_id); /** * clk_enable - inform the system when the clock source should be running. @@ -661,7 +868,7 @@ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate); * * Returns true if @parent is a possible parent for @clk, false otherwise. */ -bool clk_has_parent(struct clk *clk, struct clk *parent); +bool clk_has_parent(const struct clk *clk, const struct clk *parent); /** * clk_set_rate_range - set a rate range for a clock source @@ -773,12 +980,43 @@ static inline struct clk *devm_clk_get(struct device *dev, const char *id) return NULL; } +static inline struct clk *devm_clk_get_prepared(struct device *dev, + const char *id) +{ + return NULL; +} + +static inline struct clk *devm_clk_get_enabled(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 struct clk *devm_clk_get_optional_prepared(struct device *dev, + const char *id) +{ + return NULL; +} + +static inline struct clk *devm_clk_get_optional_enabled(struct device *dev, + const char *id) +{ + return NULL; +} + +static inline struct clk * +devm_clk_get_optional_enabled_with_rate(struct device *dev, const char *id, + unsigned long rate) +{ + return NULL; +} + static inline int __must_check devm_clk_bulk_get(struct device *dev, int num_clks, struct clk_bulk_data *clks) { @@ -798,6 +1036,12 @@ static inline int __must_check devm_clk_bulk_get_all(struct device *dev, return 0; } +static inline int __must_check devm_clk_bulk_get_all_enabled(struct device *dev, + struct clk_bulk_data **clks) +{ + return 0; +} + static inline struct clk *devm_get_clk_from_child(struct device *dev, struct device_node *np, const char *con_id) { @@ -812,14 +1056,6 @@ static inline void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks) {} static inline void devm_clk_put(struct device *dev, struct clk *clk) {} - -static inline int clk_rate_exclusive_get(struct clk *clk) -{ - return 0; -} - -static inline void clk_rate_exclusive_put(struct clk *clk) {} - static inline int clk_enable(struct clk *clk) { return 0; @@ -947,6 +1183,17 @@ static inline void clk_bulk_disable_unprepare(int num_clks, } /** + * clk_drop_range - Reset any range set on that clock + * @clk: clock source + * + * Returns success (0) or negative errno. + */ +static inline int clk_drop_range(struct clk *clk) +{ + return clk_set_rate_range(clk, 0, ULONG_MAX); +} + +/** * clk_get_optional - lookup and obtain a reference to an optional clock * producer. * @dev: device for clock "consumer" |