/* 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 <[email protected]> */ #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 … #define POST_RATE_CHANGE … #define ABORT_RATE_CHANGE … /** * 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_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_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 { … }; #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); /** * 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, 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 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 * * 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_bulk_get_all_enable - 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 success (0) or negative errno. * * 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_enable(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 int __must_check devm_clk_bulk_get_all_enable(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) { … } /* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */ static inline void clk_disable_unprepare(struct clk *clk) { … } static inline int __must_check clk_bulk_prepare_enable(int num_clks, const struct clk_bulk_data *clks) { … } static inline void clk_bulk_disable_unprepare(int num_clks, const struct clk_bulk_data *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) { … } /** * 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) { … } #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
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