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Diffstat (limited to 'include/linux/clk.h')
| -rw-r--r-- | include/linux/clk.h | 1161 |
1 files changed, 1161 insertions, 0 deletions
diff --git a/include/linux/clk.h b/include/linux/clk.h new file mode 100644 index 000000000..06f1b292f --- /dev/null +++ b/include/linux/clk.h @@ -0,0 +1,1161 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/include/linux/clk.h + * + * Copyright (C) 2004 ARM Limited. + * Written by Deep Blue Solutions Limited. + * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org> + */ +#ifndef __LINUX_CLK_H +#define __LINUX_CLK_H + +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/notifier.h> + +struct device; +struct clk; +struct device_node; +struct of_phandle_args; + +/** + * DOC: clk notifier callback types + * + * PRE_RATE_CHANGE - called immediately before the clk rate is changed, + * to indicate that the rate change will proceed. Drivers must + * immediately terminate any operations that will be affected by the + * rate change. Callbacks may either return NOTIFY_DONE, NOTIFY_OK, + * NOTIFY_STOP or NOTIFY_BAD. + * + * ABORT_RATE_CHANGE: called if the rate change failed for some reason + * after PRE_RATE_CHANGE. In this case, all registered notifiers on + * the clk will be called with ABORT_RATE_CHANGE. Callbacks must + * always return NOTIFY_DONE or NOTIFY_OK. + * + * POST_RATE_CHANGE - called after the clk rate change has successfully + * completed. Callbacks must always return NOTIFY_DONE or NOTIFY_OK. + * + */ +#define PRE_RATE_CHANGE BIT(0) +#define POST_RATE_CHANGE BIT(1) +#define ABORT_RATE_CHANGE BIT(2) + +/** + * struct clk_notifier - associate a clk with a notifier + * @clk: struct clk * to associate the notifier with + * @notifier_head: a blocking_notifier_head for this clk + * @node: linked list pointers + * + * A list of struct clk_notifier is maintained by the notifier code. + * An entry is created whenever code registers the first notifier on a + * particular @clk. Future notifiers on that @clk are added to the + * @notifier_head. + */ +struct clk_notifier { + struct clk *clk; + struct srcu_notifier_head notifier_head; + struct list_head node; +}; + +/** + * struct clk_notifier_data - rate data to pass to the notifier callback + * @clk: struct clk * being changed + * @old_rate: previous rate of this clk + * @new_rate: new rate of this clk + * + * For a pre-notifier, old_rate is the clk's rate before this rate + * change, and new_rate is what the rate will be in the future. For a + * post-notifier, old_rate and new_rate are both set to the clk's + * current rate (this was done to optimize the implementation). + */ +struct clk_notifier_data { + struct clk *clk; + unsigned long old_rate; + unsigned long new_rate; +}; + +/** + * struct clk_bulk_data - Data used for bulk clk operations. + * + * @id: clock consumer ID + * @clk: struct clk * to store the associated clock + * + * The CLK APIs provide a series of clk_bulk_() API calls as + * a convenience to consumers which require multiple clks. This + * structure is used to manage data for these calls. + */ +struct clk_bulk_data { + const char *id; + struct clk *clk; +}; + +#ifdef CONFIG_COMMON_CLK + +/** + * 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 + * + * ProTip: debugging across notifier chains can be frustrating. Make sure that + * your notifier callback function prints a nice big warning in case of + * failure. + */ +int clk_notifier_register(struct clk *clk, struct notifier_block *nb); + +/** + * 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 + * + * This gets the clock source accuracy expressed in ppb. + * A perfect clock returns 0. + */ +long clk_get_accuracy(struct clk *clk); + +/** + * clk_set_phase - adjust the phase shift of a clock signal + * @clk: clock signal source + * @degrees: number of degrees the signal is shifted + * + * Shifts the phase of a clock signal by the specified degrees. Returns 0 on + * success, -EERROR otherwise. + */ +int clk_set_phase(struct clk *clk, int degrees); + +/** + * clk_get_phase - return the phase shift of a clock signal + * @clk: clock signal source + * + * Returns the phase shift of a clock node in degrees, otherwise returns + * -EERROR. + */ +int clk_get_phase(struct clk *clk); + +/** + * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal + * @clk: clock signal source + * @num: numerator of the duty cycle ratio to be applied + * @den: denominator of the duty cycle ratio to be applied + * + * Adjust the duty cycle of a clock signal by the specified ratio. Returns 0 on + * success, -EERROR otherwise. + */ +int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den); + +/** + * 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 + * + * Returns the duty cycle ratio multiplied by the scale provided, otherwise + * returns -EERROR. + */ +int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale); + +/** + * clk_is_match - check if two clk's point to the same hardware clock + * @p: clk compared against q + * @q: clk compared against p + * + * Returns true if the two struct clk pointers both point to the same hardware + * clock node. Put differently, returns true if @p and @q + * share the same &struct clk_core object. + * + * Returns false otherwise. Note that two NULL clks are treated as matching. + */ +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); + +/** + * 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, + struct notifier_block *nb) +{ + return -ENOTSUPP; +} + +static inline int clk_notifier_unregister(struct clk *clk, + struct notifier_block *nb) +{ + 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; +} + +static inline long clk_set_phase(struct clk *clk, int phase) +{ + return -ENOTSUPP; +} + +static inline long clk_get_phase(struct clk *clk) +{ + return -ENOTSUPP; +} + +static inline int clk_set_duty_cycle(struct clk *clk, unsigned int num, + unsigned int den) +{ + return -ENOTSUPP; +} + +static inline unsigned int clk_get_scaled_duty_cycle(struct clk *clk, + unsigned int scale) +{ + return 0; +} + +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 void clk_rate_exclusive_put(struct clk *clk) {} + +#endif + +#ifdef CONFIG_HAVE_CLK_PREPARE +/** + * clk_prepare - prepare a clock source + * @clk: clock source + * + * This prepares the clock source for use. + * + * Must not be called from within atomic context. + */ +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) +{ + might_sleep(); + return 0; +} + +static inline int __must_check +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 + +/** + * 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); +void clk_bulk_unprepare(int num_clks, const struct clk_bulk_data *clks); +#else +static inline void clk_unprepare(struct clk *clk) +{ + might_sleep(); +} +static inline void clk_bulk_unprepare(int num_clks, + const struct clk_bulk_data *clks) +{ + 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 consumer ID + * + * 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.) + * + * Drivers must assume that the clock source is not enabled. + * + * clk_get should not be called from within interrupt context. + */ +struct clk *clk_get(struct device *dev, const char *id); + +/** + * clk_bulk_get - lookup and obtain a number of references to clock producer. + * @dev: device for clock "consumer" + * @num_clks: the number of clk_bulk_data + * @clks: the clk_bulk_data table of consumer + * + * This helper function allows drivers to get several clk consumers in one + * operation. If any of the clk cannot be acquired then any clks + * that were obtained will be freed before returning to the caller. + * + * Returns 0 if all clocks specified in clk_bulk_data table are obtained + * successfully, or valid IS_ERR() condition containing errno. + * The implementation uses @dev and @clk_bulk_data.id to determine the + * clock consumer, and thereby the clock producer. + * The clock returned is stored in each @clk_bulk_data.clk field. + * + * Drivers must assume that the clock source is not enabled. + * + * clk_bulk_get should not be called from within interrupt context. + */ +int __must_check clk_bulk_get(struct device *dev, int num_clks, + struct clk_bulk_data *clks); +/** + * clk_bulk_get_all - lookup and obtain all available references to clock + * producer. + * @dev: device for clock "consumer" + * @clks: pointer to the clk_bulk_data table of consumer + * + * This helper function allows drivers to get all clk consumers in one + * operation. If any of the clk cannot be acquired then any clks + * that were obtained will be freed before returning to the caller. + * + * 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. + * + * Drivers must assume that the clock source is not enabled. + * + * clk_bulk_get should not be called from within interrupt context. + */ +int __must_check clk_bulk_get_all(struct device *dev, + struct clk_bulk_data **clks); + +/** + * clk_bulk_get_optional - lookup and obtain a number of references to clock producer + * @dev: device for clock "consumer" + * @num_clks: the number of clk_bulk_data + * @clks: the clk_bulk_data table of consumer + * + * Behaves the same as clk_bulk_get() except where there is no clock producer. + * In this case, instead of returning -ENOENT, the function returns 0 and + * NULL for a clk for which a clock producer could not be determined. + */ +int __must_check clk_bulk_get_optional(struct device *dev, int num_clks, + struct clk_bulk_data *clks); +/** + * devm_clk_bulk_get - managed get multiple clk consumers + * @dev: device for clock "consumer" + * @num_clks: the number of clk_bulk_data + * @clks: the clk_bulk_data table of consumer + * + * Return 0 on success, an errno on failure. + * + * This helper function allows drivers to get several clk + * consumers in one operation with management, the clks will + * automatically be freed when the device is unbound. + */ +int __must_check devm_clk_bulk_get(struct device *dev, int num_clks, + struct clk_bulk_data *clks); +/** + * devm_clk_bulk_get_optional - managed get multiple optional consumer clocks + * @dev: device for clock "consumer" + * @num_clks: the number of clk_bulk_data + * @clks: pointer to the clk_bulk_data table of consumer + * + * Behaves the same as devm_clk_bulk_get() except where there is no clock + * producer. In this case, instead of returning -ENOENT, the function returns + * NULL for given clk. It is assumed all clocks in clk_bulk_data are optional. + * + * Returns 0 if all clocks specified in clk_bulk_data table are obtained + * successfully or for any clk there was no clk provider available, otherwise + * returns valid IS_ERR() condition containing errno. + * The implementation uses @dev and @clk_bulk_data.id to determine the + * clock consumer, and thereby the clock producer. + * The clock returned is stored in each @clk_bulk_data.clk field. + * + * Drivers must assume that the clock source is not enabled. + * + * clk_bulk_get should not be called from within interrupt context. + */ +int __must_check devm_clk_bulk_get_optional(struct device *dev, int num_clks, + struct clk_bulk_data *clks); +/** + * devm_clk_bulk_get_all - managed get multiple clk consumers + * @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 several clk + * consumers in one operation with management, the clks will + * automatically be freed when the device is unbound. + */ + +int __must_check devm_clk_bulk_get_all(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 + * + * 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 neither prepared nor + * enabled. + * + * The clock will automatically be freed when the device is unbound + * from the bus. + */ +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 + * + * 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_clk_get_optional_prepared - devm_clk_get_optional() + 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. 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_clk_get_optional_prepared(struct device *dev, const char *id); + +/** + * devm_clk_get_optional_enabled - devm_clk_get_optional() + + * 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. 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(). + * + * 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_optional_enabled(struct device *dev, const char *id); + +/** + * 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. + * @clk: clock source + * + * If the clock can not be enabled/disabled, this should return success. + * + * May be called from atomic contexts. + * + * Returns success (0) or negative errno. + */ +int clk_enable(struct clk *clk); + +/** + * clk_bulk_enable - inform the system when the set of clks should be running. + * @num_clks: the number of clk_bulk_data + * @clks: the clk_bulk_data table of consumer + * + * May be called from atomic contexts. + * + * Returns success (0) or negative errno. + */ +int __must_check clk_bulk_enable(int num_clks, + const struct clk_bulk_data *clks); + +/** + * clk_disable - inform the system when the clock source is no longer required. + * @clk: clock source + * + * Inform the system that a clock source is no longer required by + * a driver and may be shut down. + * + * May be called from atomic contexts. + * + * Implementation detail: if the clock source is shared between + * multiple drivers, clk_enable() calls must be balanced by the + * same number of clk_disable() calls for the clock source to be + * disabled. + */ +void clk_disable(struct clk *clk); + +/** + * clk_bulk_disable - inform the system when the set of clks is no + * longer required. + * @num_clks: the number of clk_bulk_data + * @clks: the clk_bulk_data table of consumer + * + * Inform the system that a set of clks is no longer required by + * a driver and may be shut down. + * + * May be called from atomic contexts. + * + * Implementation detail: if the set of clks is shared between + * multiple drivers, clk_bulk_enable() calls must be balanced by the + * same number of clk_bulk_disable() calls for the clock source to be + * disabled. + */ +void clk_bulk_disable(int num_clks, const struct clk_bulk_data *clks); + +/** + * 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. + * @clk: clock source + */ +unsigned long clk_get_rate(struct clk *clk); + +/** + * clk_put - "free" the clock source + * @clk: clock source + * + * 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 clk_put(struct clk *clk); + +/** + * clk_bulk_put - "free" the clock source + * @num_clks: the number of clk_bulk_data + * @clks: the clk_bulk_data table of consumer + * + * Note: drivers must ensure that all clk_bulk_enable calls made on this + * clock source are balanced by clk_bulk_disable calls prior to calling + * this function. + * + * clk_bulk_put should not be called from within interrupt context. + */ +void clk_bulk_put(int num_clks, struct clk_bulk_data *clks); + +/** + * clk_bulk_put_all - "free" all the clock source + * @num_clks: the number of clk_bulk_data + * @clks: the clk_bulk_data table of consumer + * + * Note: drivers must ensure that all clk_bulk_enable calls made on this + * clock source are balanced by clk_bulk_disable calls prior to calling + * this function. + * + * clk_bulk_put_all should not be called from within interrupt context. + */ +void clk_bulk_put_all(int num_clks, struct clk_bulk_data *clks); + +/** + * devm_clk_put - "free" a managed clock source + * @dev: device used to acquire 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. + */ + + +/** + * clk_round_rate - adjust a rate to the exact rate a clock can provide + * @clk: clock source + * @rate: desired clock rate in Hz + * + * This answers the question "if I were to pass @rate to clk_set_rate(), + * what clock rate would I end up with?" without changing the hardware + * in any way. In other words: + * + * rate = clk_round_rate(clk, r); + * + * and: + * + * clk_set_rate(clk, r); + * rate = clk_get_rate(clk); + * + * are equivalent except the former does not modify the clock hardware + * in any way. + * + * 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 + * @rate: desired clock rate in Hz + * + * Updating the rate starts at the top-most affected clock and then + * walks the tree down to the bottom-most clock that needs updating. + * + * Returns success (0) or negative errno. + */ +int clk_set_rate(struct clk *clk, unsigned long rate); + +/** + * clk_set_rate_exclusive- set the clock rate and claim exclusivity over + * clock source + * @clk: clock source + * @rate: desired clock rate in Hz + * + * This helper function allows drivers to atomically set the rate of a producer + * and claim exclusivity over the rate control of the producer. + * + * It is essentially a combination of clk_set_rate() and + * clk_rate_exclusite_get(). Caller must balance this call with a call to + * clk_rate_exclusive_put() + * + * Returns success (0) or negative errno. + */ +int clk_set_rate_exclusive(struct clk *clk, unsigned long rate); + +/** + * clk_has_parent - check if a clock is a possible parent for another + * @clk: clock source + * @parent: parent clock source + * + * This function can be used in drivers that need to check that a clock can be + * the parent of another without actually changing the parent. + * + * Returns true if @parent is a possible parent for @clk, false otherwise. + */ +bool clk_has_parent(const struct clk *clk, const struct clk *parent); + +/** + * clk_set_rate_range - set a rate range for a clock source + * @clk: clock source + * @min: desired minimum clock rate in Hz, inclusive + * @max: desired maximum clock rate in Hz, inclusive + * + * Returns success (0) or negative errno. + */ +int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max); + +/** + * clk_set_min_rate - set a minimum clock rate for a clock source + * @clk: clock source + * @rate: desired minimum clock rate in Hz, inclusive + * + * Returns success (0) or negative errno. + */ +int clk_set_min_rate(struct clk *clk, unsigned long rate); + +/** + * clk_set_max_rate - set a maximum clock rate for a clock source + * @clk: clock source + * @rate: desired maximum clock rate in Hz, inclusive + * + * Returns success (0) or negative errno. + */ +int clk_set_max_rate(struct clk *clk, unsigned long rate); + +/** + * clk_set_parent - set the parent clock source for this clock + * @clk: clock source + * @parent: parent clock source + * + * Returns success (0) or negative errno. + */ +int clk_set_parent(struct clk *clk, struct clk *parent); + +/** + * clk_get_parent - get the parent clock source for this clock + * @clk: clock source + * + * Returns struct clk corresponding to parent clock source, or + * valid IS_ERR() condition containing errno. + */ +struct clk *clk_get_parent(struct clk *clk); + +/** + * clk_get_sys - get a clock based upon the device name + * @dev_id: device name + * @con_id: connection ID + * + * Returns a struct clk corresponding to the clock producer, or + * valid IS_ERR() condition containing errno. The implementation + * uses @dev_id and @con_id to determine the clock consumer, and + * thereby the clock producer. In contrast to clk_get() this function + * takes the device name instead of the device itself for identification. + * + * Drivers must assume that the clock source is not enabled. + * + * clk_get_sys should not be called from within interrupt context. + */ +struct clk *clk_get_sys(const char *dev_id, const char *con_id); + +/** + * clk_save_context - save clock context for poweroff + * + * Saves the context of the clock register for powerstates in which the + * contents of the registers will be lost. Occurs deep within the suspend + * code so locking is not necessary. + */ +int clk_save_context(void); + +/** + * clk_restore_context - restore clock context after poweroff + * + * This occurs with all clocks enabled. Occurs deep within the resume code + * so locking is not necessary. + */ +void clk_restore_context(void); + +#else /* !CONFIG_HAVE_CLK */ + +static inline struct clk *clk_get(struct device *dev, const char *id) +{ + return NULL; +} + +static inline int __must_check clk_bulk_get(struct device *dev, int num_clks, + struct clk_bulk_data *clks) +{ + return 0; +} + +static inline int __must_check clk_bulk_get_optional(struct device *dev, + int num_clks, struct clk_bulk_data *clks) +{ + return 0; +} + +static inline int __must_check clk_bulk_get_all(struct device *dev, + struct clk_bulk_data **clks) +{ + return 0; +} + +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 int __must_check devm_clk_bulk_get(struct device *dev, int num_clks, + struct clk_bulk_data *clks) +{ + return 0; +} + +static inline int __must_check devm_clk_bulk_get_optional(struct device *dev, + int num_clks, struct clk_bulk_data *clks) +{ + return 0; +} + +static inline int __must_check devm_clk_bulk_get_all(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) +{ + return NULL; +} + +static inline void clk_put(struct clk *clk) {} + +static inline void clk_bulk_put(int num_clks, struct clk_bulk_data *clks) {} + +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_enable(struct clk *clk) +{ + return 0; +} + +static inline int __must_check clk_bulk_enable(int num_clks, + const struct clk_bulk_data *clks) +{ + return 0; +} + +static inline void clk_disable(struct clk *clk) {} + + +static inline void clk_bulk_disable(int num_clks, + const struct clk_bulk_data *clks) {} + +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 int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) +{ + return 0; +} + +static inline long clk_round_rate(struct clk *clk, unsigned long rate) +{ + return 0; +} + +static inline bool clk_has_parent(struct clk *clk, struct clk *parent) +{ + return true; +} + +static inline int clk_set_rate_range(struct clk *clk, unsigned long min, + unsigned long max) +{ + return 0; +} + +static inline int clk_set_min_rate(struct clk *clk, unsigned long rate) +{ + return 0; +} + +static inline int clk_set_max_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; +} + +static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id) +{ + return NULL; +} + +static inline int clk_save_context(void) +{ + return 0; +} + +static inline void clk_restore_context(void) {} + +#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); +} + +static inline int __must_check +clk_bulk_prepare_enable(int num_clks, const struct clk_bulk_data *clks) +{ + int ret; + + ret = clk_bulk_prepare(num_clks, clks); + if (ret) + return ret; + ret = clk_bulk_enable(num_clks, clks); + if (ret) + clk_bulk_unprepare(num_clks, clks); + + return ret; +} + +static inline void clk_bulk_disable_unprepare(int num_clks, + const struct clk_bulk_data *clks) +{ + clk_bulk_disable(num_clks, clks); + clk_bulk_unprepare(num_clks, 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" + * @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); +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); +} +static inline struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) +{ + return ERR_PTR(-ENOENT); +} +#endif + +#endif |