// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2010-2011 Canonical Ltd <[email protected]> * Copyright (C) 2011-2012 Linaro Ltd <[email protected]> * * Standard functionality for the common clock API. See Documentation/driver-api/clk.rst */ #include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/clk/clk-conf.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/spinlock.h> #include <linux/err.h> #include <linux/list.h> #include <linux/slab.h> #include <linux/of.h> #include <linux/device.h> #include <linux/init.h> #include <linux/pm_runtime.h> #include <linux/sched.h> #include <linux/clkdev.h> #include "clk.h" static DEFINE_SPINLOCK(enable_lock); static DEFINE_MUTEX(prepare_lock); static struct task_struct *prepare_owner; static struct task_struct *enable_owner; static int prepare_refcnt; static int enable_refcnt; static HLIST_HEAD(clk_root_list); static HLIST_HEAD(clk_orphan_list); static LIST_HEAD(clk_notifier_list); /* List of registered clks that use runtime PM */ static HLIST_HEAD(clk_rpm_list); static DEFINE_MUTEX(clk_rpm_list_lock); static const struct hlist_head *all_lists[] = …; /*** private data structures ***/ struct clk_parent_map { … }; struct clk_core { … }; #define CREATE_TRACE_POINTS #include <trace/events/clk.h> struct clk { … }; /*** runtime pm ***/ static int clk_pm_runtime_get(struct clk_core *core) { … } static void clk_pm_runtime_put(struct clk_core *core) { … } /** * clk_pm_runtime_get_all() - Runtime "get" all clk provider devices * * Call clk_pm_runtime_get() on all runtime PM enabled clks in the clk tree so * that disabling unused clks avoids a deadlock where a device is runtime PM * resuming/suspending and the runtime PM callback is trying to grab the * prepare_lock for something like clk_prepare_enable() while * clk_disable_unused_subtree() holds the prepare_lock and is trying to runtime * PM resume/suspend the device as well. * * Context: Acquires the 'clk_rpm_list_lock' and returns with the lock held on * success. Otherwise the lock is released on failure. * * Return: 0 on success, negative errno otherwise. */ static int clk_pm_runtime_get_all(void) { … } /** * clk_pm_runtime_put_all() - Runtime "put" all clk provider devices * * Put the runtime PM references taken in clk_pm_runtime_get_all() and release * the 'clk_rpm_list_lock'. */ static void clk_pm_runtime_put_all(void) { … } static void clk_pm_runtime_init(struct clk_core *core) { … } /*** locking ***/ static void clk_prepare_lock(void) { … } static void clk_prepare_unlock(void) { … } static unsigned long clk_enable_lock(void) __acquires(enable_lock) { … } static void clk_enable_unlock(unsigned long flags) __releases(enable_lock) { … } static bool clk_core_rate_is_protected(struct clk_core *core) { … } static bool clk_core_is_prepared(struct clk_core *core) { … } static bool clk_core_is_enabled(struct clk_core *core) { … } /*** helper functions ***/ const char *__clk_get_name(const struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); const char *clk_hw_get_name(const struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); struct clk_hw *__clk_get_hw(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); unsigned int clk_hw_get_num_parents(const struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); static struct clk_core *__clk_lookup_subtree(const char *name, struct clk_core *core) { … } static struct clk_core *clk_core_lookup(const char *name) { … } #ifdef CONFIG_OF static int of_parse_clkspec(const struct device_node *np, int index, const char *name, struct of_phandle_args *out_args); static struct clk_hw * of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec); #else static inline int of_parse_clkspec(const struct device_node *np, int index, const char *name, struct of_phandle_args *out_args) { return -ENOENT; } static inline struct clk_hw * of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec) { return ERR_PTR(-ENOENT); } #endif /** * clk_core_get - Find the clk_core parent of a clk * @core: clk to find parent of * @p_index: parent index to search for * * This is the preferred method for clk providers to find the parent of a * clk when that parent is external to the clk controller. The parent_names * array is indexed and treated as a local name matching a string in the device * node's 'clock-names' property or as the 'con_id' matching the device's * dev_name() in a clk_lookup. This allows clk providers to use their own * namespace instead of looking for a globally unique parent string. * * For example the following DT snippet would allow a clock registered by the * clock-controller@c001 that has a clk_init_data::parent_data array * with 'xtal' in the 'name' member to find the clock provided by the * clock-controller@f00abcd without needing to get the globally unique name of * the xtal clk. * * parent: clock-controller@f00abcd { * reg = <0xf00abcd 0xabcd>; * #clock-cells = <0>; * }; * * clock-controller@c001 { * reg = <0xc001 0xf00d>; * clocks = <&parent>; * clock-names = "xtal"; * #clock-cells = <1>; * }; * * Returns: -ENOENT when the provider can't be found or the clk doesn't * exist in the provider or the name can't be found in the DT node or * in a clkdev lookup. NULL when the provider knows about the clk but it * isn't provided on this system. * A valid clk_core pointer when the clk can be found in the provider. */ static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index) { … } static void clk_core_fill_parent_index(struct clk_core *core, u8 index) { … } static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core, u8 index) { … } struct clk_hw * clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index) { … } EXPORT_SYMBOL_GPL(…); unsigned int __clk_get_enable_count(struct clk *clk) { … } static unsigned long clk_core_get_rate_nolock(struct clk_core *core) { … } unsigned long clk_hw_get_rate(const struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core) { … } unsigned long clk_hw_get_flags(const struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); bool clk_hw_is_prepared(const struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); bool clk_hw_rate_is_protected(const struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); bool clk_hw_is_enabled(const struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); bool __clk_is_enabled(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static bool mux_is_better_rate(unsigned long rate, unsigned long now, unsigned long best, unsigned long flags) { … } static void clk_core_init_rate_req(struct clk_core * const core, struct clk_rate_request *req, unsigned long rate); static int clk_core_round_rate_nolock(struct clk_core *core, struct clk_rate_request *req); static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent) { … } static void clk_core_forward_rate_req(struct clk_core *core, const struct clk_rate_request *old_req, struct clk_core *parent, struct clk_rate_request *req, unsigned long parent_rate) { … } static int clk_core_determine_rate_no_reparent(struct clk_hw *hw, struct clk_rate_request *req) { … } int clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req, unsigned long flags) { … } EXPORT_SYMBOL_GPL(…); struct clk *__clk_lookup(const char *name) { … } static void clk_core_get_boundaries(struct clk_core *core, unsigned long *min_rate, unsigned long *max_rate) { … } /* * clk_hw_get_rate_range() - returns the clock rate range for a hw clk * @hw: the hw clk we want to get the range from * @min_rate: pointer to the variable that will hold the minimum * @max_rate: pointer to the variable that will hold the maximum * * Fills the @min_rate and @max_rate variables with the minimum and * maximum that clock can reach. */ void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate, unsigned long *max_rate) { … } EXPORT_SYMBOL_GPL(…); static bool clk_core_check_boundaries(struct clk_core *core, unsigned long min_rate, unsigned long max_rate) { … } void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate, unsigned long max_rate) { … } EXPORT_SYMBOL_GPL(…); /* * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk * @hw: mux type clk to determine rate on * @req: rate request, also used to return preferred parent and frequencies * * Helper for finding best parent to provide a given frequency. This can be used * directly as a determine_rate callback (e.g. for a mux), or from a more * complex clock that may combine a mux with other operations. * * Returns: 0 on success, -EERROR value on error */ int __clk_mux_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { … } EXPORT_SYMBOL_GPL(…); int __clk_mux_determine_rate_closest(struct clk_hw *hw, struct clk_rate_request *req) { … } EXPORT_SYMBOL_GPL(…); /* * clk_hw_determine_rate_no_reparent - clk_ops::determine_rate implementation for a clk that doesn't reparent * @hw: mux type clk to determine rate on * @req: rate request, also used to return preferred frequency * * Helper for finding best parent rate to provide a given frequency. * This can be used directly as a determine_rate callback (e.g. for a * mux), or from a more complex clock that may combine a mux with other * operations. * * Returns: 0 on success, -EERROR value on error */ int clk_hw_determine_rate_no_reparent(struct clk_hw *hw, struct clk_rate_request *req) { … } EXPORT_SYMBOL_GPL(…); /*** clk api ***/ static void clk_core_rate_unprotect(struct clk_core *core) { … } static int clk_core_rate_nuke_protect(struct clk_core *core) { … } /** * clk_rate_exclusive_put - release exclusivity over clock rate control * @clk: the clk over which the exclusivity is released * * clk_rate_exclusive_put() completes a critical section during which a clock * consumer cannot tolerate any other consumer making any operation on the * clock which could result in a rate change or rate glitch. Exclusive clocks * cannot have their rate changed, either directly or indirectly due to changes * further up the parent chain of clocks. As a result, clocks up parent chain * also get under exclusive control of the calling consumer. * * If exlusivity is claimed more than once on clock, even by the same consumer, * the rate effectively gets locked as exclusivity can't be preempted. * * Calls to clk_rate_exclusive_put() must be balanced with calls to * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return * error status. */ void clk_rate_exclusive_put(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static void clk_core_rate_protect(struct clk_core *core) { … } static void clk_core_rate_restore_protect(struct clk_core *core, int count) { … } /** * clk_rate_exclusive_get - get exclusivity over the clk rate control * @clk: the clk over which the exclusity of rate control is requested * * clk_rate_exclusive_get() begins a critical section during which a clock * consumer cannot tolerate any other consumer making any operation on the * clock which could result in a rate change or rate glitch. Exclusive clocks * cannot have their rate changed, either directly or indirectly due to changes * further up the parent chain of clocks. As a result, clocks up parent chain * also get under exclusive control of the calling consumer. * * If exlusivity is claimed more than once on clock, even by the same consumer, * the rate effectively gets locked as exclusivity can't be preempted. * * Calls to clk_rate_exclusive_get() should be balanced with calls to * clk_rate_exclusive_put(). Calls to this function may sleep. * Returns 0 on success, -EERROR otherwise */ int clk_rate_exclusive_get(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static void devm_clk_rate_exclusive_put(void *data) { … } int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static void clk_core_unprepare(struct clk_core *core) { … } static void clk_core_unprepare_lock(struct clk_core *core) { … } /** * clk_unprepare - undo preparation of a clock source * @clk: the clk being unprepared * * clk_unprepare may sleep, which differentiates it from clk_disable. In a * simple case, clk_unprepare can be used instead of clk_disable to gate a clk * if the operation may sleep. One example is a clk which is accessed over * I2c. In the complex case a clk gate operation may require a fast and a slow * part. It is this reason that clk_unprepare and clk_disable are not mutually * exclusive. In fact clk_disable must be called before clk_unprepare. */ void clk_unprepare(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static int clk_core_prepare(struct clk_core *core) { … } static int clk_core_prepare_lock(struct clk_core *core) { … } /** * clk_prepare - prepare a clock source * @clk: the clk being prepared * * clk_prepare may sleep, which differentiates it from clk_enable. In a simple * case, clk_prepare can be used instead of clk_enable to ungate a clk if the * operation may sleep. One example is a clk which is accessed over I2c. In * the complex case a clk ungate operation may require a fast and a slow part. * It is this reason that clk_prepare and clk_enable are not mutually * exclusive. In fact clk_prepare must be called before clk_enable. * Returns 0 on success, -EERROR otherwise. */ int clk_prepare(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static void clk_core_disable(struct clk_core *core) { … } static void clk_core_disable_lock(struct clk_core *core) { … } /** * clk_disable - gate a clock * @clk: the clk being gated * * clk_disable must not sleep, which differentiates it from clk_unprepare. In * a simple case, clk_disable can be used instead of clk_unprepare to gate a * clk if the operation is fast and will never sleep. One example is a * SoC-internal clk which is controlled via simple register writes. In the * complex case a clk gate operation may require a fast and a slow part. It is * this reason that clk_unprepare and clk_disable are not mutually exclusive. * In fact clk_disable must be called before clk_unprepare. */ void clk_disable(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static int clk_core_enable(struct clk_core *core) { … } static int clk_core_enable_lock(struct clk_core *core) { … } /** * clk_gate_restore_context - restore context for poweroff * @hw: the clk_hw pointer of clock whose state is to be restored * * The clock gate restore context function enables or disables * the gate clocks based on the enable_count. This is done in cases * where the clock context is lost and based on the enable_count * the clock either needs to be enabled/disabled. This * helps restore the state of gate clocks. */ void clk_gate_restore_context(struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); static int clk_core_save_context(struct clk_core *core) { … } static void clk_core_restore_context(struct clk_core *core) { … } /** * 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. Returns 0 on success. */ int clk_save_context(void) { … } EXPORT_SYMBOL_GPL(…); /** * clk_restore_context - restore clock context after poweroff * * Restore the saved clock context upon resume. * */ void clk_restore_context(void) { … } EXPORT_SYMBOL_GPL(…); /** * clk_enable - ungate a clock * @clk: the clk being ungated * * clk_enable must not sleep, which differentiates it from clk_prepare. In a * simple case, clk_enable can be used instead of clk_prepare to ungate a clk * if the operation will never sleep. One example is a SoC-internal clk which * is controlled via simple register writes. In the complex case a clk ungate * operation may require a fast and a slow part. It is this reason that * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare * must be called before clk_enable. Returns 0 on success, -EERROR * otherwise. */ int clk_enable(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); /** * 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 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) { … } EXPORT_SYMBOL_GPL(…); static int clk_core_prepare_enable(struct clk_core *core) { … } static void clk_core_disable_unprepare(struct clk_core *core) { … } static void __init clk_unprepare_unused_subtree(struct clk_core *core) { … } static void __init clk_disable_unused_subtree(struct clk_core *core) { … } static bool clk_ignore_unused __initdata; static int __init clk_ignore_unused_setup(char *__unused) { … } __setup(…); static int __init clk_disable_unused(void) { … } late_initcall_sync(clk_disable_unused); static int clk_core_determine_round_nolock(struct clk_core *core, struct clk_rate_request *req) { … } static void clk_core_init_rate_req(struct clk_core * const core, struct clk_rate_request *req, unsigned long rate) { … } /** * clk_hw_init_rate_request - Initializes a clk_rate_request * @hw: the clk for which we want to submit a rate request * @req: the clk_rate_request structure we want to initialise * @rate: the rate which is to be requested * * Initializes a clk_rate_request structure to submit to * __clk_determine_rate() or similar functions. */ void clk_hw_init_rate_request(const struct clk_hw *hw, struct clk_rate_request *req, unsigned long rate) { … } EXPORT_SYMBOL_GPL(…); /** * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent * @hw: the original clock that got the rate request * @old_req: the original clk_rate_request structure we want to forward * @parent: the clk we want to forward @old_req to * @req: the clk_rate_request structure we want to initialise * @parent_rate: The rate which is to be requested to @parent * * Initializes a clk_rate_request structure to submit to a clock parent * in __clk_determine_rate() or similar functions. */ void clk_hw_forward_rate_request(const struct clk_hw *hw, const struct clk_rate_request *old_req, const struct clk_hw *parent, struct clk_rate_request *req, unsigned long parent_rate) { … } EXPORT_SYMBOL_GPL(…); static bool clk_core_can_round(struct clk_core * const core) { … } static int clk_core_round_rate_nolock(struct clk_core *core, struct clk_rate_request *req) { … } /** * __clk_determine_rate - get the closest rate actually supported by a clock * @hw: determine the rate of this clock * @req: target rate request * * Useful for clk_ops such as .set_rate and .determine_rate. */ int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { … } EXPORT_SYMBOL_GPL(…); /** * clk_hw_round_rate() - round the given rate for a hw clk * @hw: the hw clk for which we are rounding a rate * @rate: the rate which is to be rounded * * Takes in a rate as input and rounds it to a rate that the clk can actually * use. * * Context: prepare_lock must be held. * For clk providers to call from within clk_ops such as .round_rate, * .determine_rate. * * Return: returns rounded rate of hw clk if clk supports round_rate operation * else returns the parent rate. */ unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate) { … } EXPORT_SYMBOL_GPL(…); /** * clk_round_rate - round the given rate for a clk * @clk: the clk for which we are rounding a rate * @rate: the rate which is to be rounded * * Takes in a rate as input and rounds it to a rate that the clk can actually * use which is then returned. If clk doesn't support round_rate operation * then the parent rate is returned. */ long clk_round_rate(struct clk *clk, unsigned long rate) { … } EXPORT_SYMBOL_GPL(…); /** * __clk_notify - call clk notifier chain * @core: clk that is changing rate * @msg: clk notifier type (see include/linux/clk.h) * @old_rate: old clk rate * @new_rate: new clk rate * * Triggers a notifier call chain on the clk rate-change notification * for 'clk'. Passes a pointer to the struct clk and the previous * and current rates to the notifier callback. Intended to be called by * internal clock code only. Returns NOTIFY_DONE from the last driver * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if * a driver returns that. */ static int __clk_notify(struct clk_core *core, unsigned long msg, unsigned long old_rate, unsigned long new_rate) { … } /** * __clk_recalc_accuracies * @core: first clk in the subtree * * Walks the subtree of clks starting with clk and recalculates accuracies as * it goes. Note that if a clk does not implement the .recalc_accuracy * callback then it is assumed that the clock will take on the accuracy of its * parent. */ static void __clk_recalc_accuracies(struct clk_core *core) { … } static long clk_core_get_accuracy_recalc(struct clk_core *core) { … } /** * clk_get_accuracy - return the accuracy of clk * @clk: the clk whose accuracy is being returned * * Simply returns the cached accuracy of the clk, unless * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be * issued. * If clk is NULL then returns 0. */ long clk_get_accuracy(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static unsigned long clk_recalc(struct clk_core *core, unsigned long parent_rate) { … } /** * __clk_recalc_rates * @core: first clk in the subtree * @update_req: Whether req_rate should be updated with the new rate * @msg: notification type (see include/linux/clk.h) * * Walks the subtree of clks starting with clk and recalculates rates as it * goes. Note that if a clk does not implement the .recalc_rate callback then * it is assumed that the clock will take on the rate of its parent. * * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, * if necessary. */ static void __clk_recalc_rates(struct clk_core *core, bool update_req, unsigned long msg) { … } static unsigned long clk_core_get_rate_recalc(struct clk_core *core) { … } /** * clk_get_rate - return the rate of clk * @clk: the clk whose rate is being returned * * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag * is set, which means a recalc_rate will be issued. Can be called regardless of * the clock enabledness. If clk is NULL, or if an error occurred, then returns * 0. */ unsigned long clk_get_rate(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static int clk_fetch_parent_index(struct clk_core *core, struct clk_core *parent) { … } /** * clk_hw_get_parent_index - return the index of the parent clock * @hw: clk_hw associated with the clk being consumed * * Fetches and returns the index of parent clock. Returns -EINVAL if the given * clock does not have a current parent. */ int clk_hw_get_parent_index(struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); /* * Update the orphan status of @core and all its children. */ static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan) { … } static void clk_reparent(struct clk_core *core, struct clk_core *new_parent) { … } static struct clk_core *__clk_set_parent_before(struct clk_core *core, struct clk_core *parent) { … } static void __clk_set_parent_after(struct clk_core *core, struct clk_core *parent, struct clk_core *old_parent) { … } static int __clk_set_parent(struct clk_core *core, struct clk_core *parent, u8 p_index) { … } /** * __clk_speculate_rates * @core: first clk in the subtree * @parent_rate: the "future" rate of clk's parent * * Walks the subtree of clks starting with clk, speculating rates as it * goes and firing off PRE_RATE_CHANGE notifications as necessary. * * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending * pre-rate change notifications and returns early if no clks in the * subtree have subscribed to the notifications. Note that if a clk does not * implement the .recalc_rate callback then it is assumed that the clock will * take on the rate of its parent. */ static int __clk_speculate_rates(struct clk_core *core, unsigned long parent_rate) { … } static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate, struct clk_core *new_parent, u8 p_index) { … } /* * calculate the new rates returning the topmost clock that has to be * changed. */ static struct clk_core *clk_calc_new_rates(struct clk_core *core, unsigned long rate) { … } /* * Notify about rate changes in a subtree. Always walk down the whole tree * so that in case of an error we can walk down the whole tree again and * abort the change. */ static struct clk_core *clk_propagate_rate_change(struct clk_core *core, unsigned long event) { … } /* * walk down a subtree and set the new rates notifying the rate * change on the way */ static void clk_change_rate(struct clk_core *core) { … } static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core, unsigned long req_rate) { … } static int clk_core_set_rate_nolock(struct clk_core *core, unsigned long req_rate) { … } /** * clk_set_rate - specify a new rate for clk * @clk: the clk whose rate is being changed * @rate: the new rate for clk * * In the simplest case clk_set_rate will only adjust the rate of clk. * * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to * propagate up to clk's parent; whether or not this happens depends on the * outcome of clk's .round_rate implementation. If *parent_rate is unchanged * after calling .round_rate then upstream parent propagation is ignored. If * *parent_rate comes back with a new rate for clk's parent then we propagate * up to clk's parent and set its rate. Upward propagation will continue * until either a clk does not support the CLK_SET_RATE_PARENT flag or * .round_rate stops requesting changes to clk's parent_rate. * * Rate changes are accomplished via tree traversal that also recalculates the * rates for the clocks and fires off POST_RATE_CHANGE notifiers. * * Returns 0 on success, -EERROR otherwise. */ int clk_set_rate(struct clk *clk, unsigned long rate) { … } EXPORT_SYMBOL_GPL(…); /** * clk_set_rate_exclusive - specify a new rate and get exclusive control * @clk: the clk whose rate is being changed * @rate: the new rate for clk * * This is a combination of clk_set_rate() and clk_rate_exclusive_get() * within a critical section * * This can be used initially to ensure that at least 1 consumer is * satisfied when several consumers are competing for exclusivity over the * same clock provider. * * The exclusivity is not applied if setting the rate failed. * * Calls to clk_rate_exclusive_get() should be balanced with calls to * clk_rate_exclusive_put(). * * Returns 0 on success, -EERROR otherwise. */ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate) { … } EXPORT_SYMBOL_GPL(…); static int clk_set_rate_range_nolock(struct clk *clk, unsigned long min, unsigned long max) { … } /** * 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 * * Return: 0 for success or negative errno on failure. */ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * clk_get_parent - return the parent of a clk * @clk: the clk whose parent gets returned * * Simply returns clk->parent. Returns NULL if clk is NULL. */ struct clk *clk_get_parent(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); static struct clk_core *__clk_init_parent(struct clk_core *core) { … } static void clk_core_reparent(struct clk_core *core, struct clk_core *new_parent) { … } void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); static int clk_core_set_parent_nolock(struct clk_core *core, struct clk_core *parent) { … } int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent) { … } EXPORT_SYMBOL_GPL(…); /** * clk_set_parent - switch the parent of a mux clk * @clk: the mux clk whose input we are switching * @parent: the new input to clk * * Re-parent clk to use parent as its new input source. If clk is in * prepared state, the clk will get enabled for the duration of this call. If * that's not acceptable for a specific clk (Eg: the consumer can't handle * that, the reparenting is glitchy in hardware, etc), use the * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. * * After successfully changing clk's parent clk_set_parent will update the * clk topology, sysfs topology and propagate rate recalculation via * __clk_recalc_rates. * * Returns 0 on success, -EERROR otherwise. */ int clk_set_parent(struct clk *clk, struct clk *parent) { … } EXPORT_SYMBOL_GPL(…); static int clk_core_set_phase_nolock(struct clk_core *core, int degrees) { … } /** * 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. * * This function makes no distinction about the input or reference * signal that we adjust the clock signal phase against. For example * phase locked-loop clock signal generators we may shift phase with * respect to feedback clock signal input, but for other cases the * clock phase may be shifted with respect to some other, unspecified * signal. * * Additionally the concept of phase shift does not propagate through * the clock tree hierarchy, which sets it apart from clock rates and * clock accuracy. A parent clock phase attribute does not have an * impact on the phase attribute of a child clock. */ int clk_set_phase(struct clk *clk, int degrees) { … } EXPORT_SYMBOL_GPL(…); static int clk_core_get_phase(struct clk_core *core) { … } /** * 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) { … } EXPORT_SYMBOL_GPL(…); static void clk_core_reset_duty_cycle_nolock(struct clk_core *core) { … } static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core); static int clk_core_update_duty_cycle_nolock(struct clk_core *core) { … } static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core) { … } static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core, struct clk_duty *duty); static int clk_core_set_duty_cycle_nolock(struct clk_core *core, struct clk_duty *duty) { … } static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core, struct clk_duty *duty) { … } /** * 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 * * Apply the duty cycle ratio if the ratio is valid and the clock can * perform this operation * * Returns (0) on success, a negative errno otherwise. */ int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den) { … } EXPORT_SYMBOL_GPL(…); static int clk_core_get_scaled_duty_cycle(struct clk_core *core, unsigned int scale) { … } /** * 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 of a clock node multiplied by the provided * scaling factor, or negative errno on error. */ int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale) { … } EXPORT_SYMBOL_GPL(…); /** * 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 struct clk *p and struct clk *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) { … } EXPORT_SYMBOL_GPL(…); /*** debugfs support ***/ #ifdef CONFIG_DEBUG_FS #include <linux/debugfs.h> static struct dentry *rootdir; static int inited = …; static DEFINE_MUTEX(clk_debug_lock); static HLIST_HEAD(clk_debug_list); static struct hlist_head *orphan_list[] = …; static void clk_summary_show_one(struct seq_file *s, struct clk_core *c, int level) { … } static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c, int level) { … } static int clk_summary_show(struct seq_file *s, void *data) { … } DEFINE_SHOW_ATTRIBUTE(…); static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level) { … } static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level) { … } static int clk_dump_show(struct seq_file *s, void *data) { … } DEFINE_SHOW_ATTRIBUTE(…); #undef CLOCK_ALLOW_WRITE_DEBUGFS #ifdef CLOCK_ALLOW_WRITE_DEBUGFS /* * This can be dangerous, therefore don't provide any real compile time * configuration option for this feature. * People who want to use this will need to modify the source code directly. */ static int clk_rate_set(void *data, u64 val) { struct clk_core *core = data; int ret; clk_prepare_lock(); ret = clk_core_set_rate_nolock(core, val); clk_prepare_unlock(); return ret; } #define clk_rate_mode … static int clk_phase_set(void *data, u64 val) { struct clk_core *core = data; int degrees = do_div(val, 360); int ret; clk_prepare_lock(); ret = clk_core_set_phase_nolock(core, degrees); clk_prepare_unlock(); return ret; } #define clk_phase_mode … static int clk_prepare_enable_set(void *data, u64 val) { struct clk_core *core = data; int ret = 0; if (val) ret = clk_prepare_enable(core->hw->clk); else clk_disable_unprepare(core->hw->clk); return ret; } static int clk_prepare_enable_get(void *data, u64 *val) { struct clk_core *core = data; *val = core->enable_count && core->prepare_count; return 0; } DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get, clk_prepare_enable_set, "%llu\n"); #else #define clk_rate_set … #define clk_rate_mode … #define clk_phase_set … #define clk_phase_mode … #endif static int clk_rate_get(void *data, u64 *val) { … } DEFINE_DEBUGFS_ATTRIBUTE(…); static int clk_phase_get(void *data, u64 *val) { … } DEFINE_DEBUGFS_ATTRIBUTE(…); static const struct { … } clk_flags[] = …; static int clk_flags_show(struct seq_file *s, void *data) { … } DEFINE_SHOW_ATTRIBUTE(…); static void possible_parent_show(struct seq_file *s, struct clk_core *core, unsigned int i, char terminator) { … } static int possible_parents_show(struct seq_file *s, void *data) { … } DEFINE_SHOW_ATTRIBUTE(…); static int current_parent_show(struct seq_file *s, void *data) { … } DEFINE_SHOW_ATTRIBUTE(…); #ifdef CLOCK_ALLOW_WRITE_DEBUGFS static ssize_t current_parent_write(struct file *file, const char __user *ubuf, size_t count, loff_t *ppos) { struct seq_file *s = file->private_data; struct clk_core *core = s->private; struct clk_core *parent; u8 idx; int err; err = kstrtou8_from_user(ubuf, count, 0, &idx); if (err < 0) return err; parent = clk_core_get_parent_by_index(core, idx); if (!parent) return -ENOENT; clk_prepare_lock(); err = clk_core_set_parent_nolock(core, parent); clk_prepare_unlock(); if (err) return err; return count; } static const struct file_operations current_parent_rw_fops = { .open = current_parent_open, .write = current_parent_write, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; #endif static int clk_duty_cycle_show(struct seq_file *s, void *data) { … } DEFINE_SHOW_ATTRIBUTE(…); static int clk_min_rate_show(struct seq_file *s, void *data) { … } DEFINE_SHOW_ATTRIBUTE(…); static int clk_max_rate_show(struct seq_file *s, void *data) { … } DEFINE_SHOW_ATTRIBUTE(…); static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) { … } /** * clk_debug_register - add a clk node to the debugfs clk directory * @core: the clk being added to the debugfs clk directory * * Dynamically adds a clk to the debugfs clk directory if debugfs has been * initialized. Otherwise it bails out early since the debugfs clk directory * will be created lazily by clk_debug_init as part of a late_initcall. */ static void clk_debug_register(struct clk_core *core) { … } /** * clk_debug_unregister - remove a clk node from the debugfs clk directory * @core: the clk being removed from the debugfs clk directory * * Dynamically removes a clk and all its child nodes from the * debugfs clk directory if clk->dentry points to debugfs created by * clk_debug_register in __clk_core_init. */ static void clk_debug_unregister(struct clk_core *core) { … } /** * clk_debug_init - lazily populate the debugfs clk directory * * clks are often initialized very early during boot before memory can be * dynamically allocated and well before debugfs is setup. This function * populates the debugfs clk directory once at boot-time when we know that * debugfs is setup. It should only be called once at boot-time, all other clks * added dynamically will be done so with clk_debug_register. */ static int __init clk_debug_init(void) { … } late_initcall(clk_debug_init); #else static inline void clk_debug_register(struct clk_core *core) { } static inline void clk_debug_unregister(struct clk_core *core) { } #endif static void clk_core_reparent_orphans_nolock(void) { … } /** * __clk_core_init - initialize the data structures in a struct clk_core * @core: clk_core being initialized * * Initializes the lists in struct clk_core, queries the hardware for the * parent and rate and sets them both. */ static int __clk_core_init(struct clk_core *core) { … } /** * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core * @core: clk to add consumer to * @clk: consumer to link to a clk */ static void clk_core_link_consumer(struct clk_core *core, struct clk *clk) { … } /** * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core * @clk: consumer to unlink */ static void clk_core_unlink_consumer(struct clk *clk) { … } /** * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core * @core: clk to allocate a consumer for * @dev_id: string describing device name * @con_id: connection ID string on device * * Returns: clk consumer left unlinked from the consumer list */ static struct clk *alloc_clk(struct clk_core *core, const char *dev_id, const char *con_id) { … } /** * free_clk - Free a clk consumer * @clk: clk consumer to free * * Note, this assumes the clk has been unlinked from the clk_core consumer * list. */ static void free_clk(struct clk *clk) { … } /** * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given * a clk_hw * @dev: clk consumer device * @hw: clk_hw associated with the clk being consumed * @dev_id: string describing device name * @con_id: connection ID string on device * * This is the main function used to create a clk pointer for use by clk * consumers. It connects a consumer to the clk_core and clk_hw structures * used by the framework and clk provider respectively. */ struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw, const char *dev_id, const char *con_id) { … } /** * clk_hw_get_clk - get clk consumer given an clk_hw * @hw: clk_hw associated with the clk being consumed * @con_id: connection ID string on device * * Returns: new clk consumer * This is the function to be used by providers which need * to get a consumer clk and act on the clock element * Calls to this function must be balanced with calls clk_put() */ struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id) { … } EXPORT_SYMBOL(…); static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist) { … } static int clk_core_populate_parent_map(struct clk_core *core, const struct clk_init_data *init) { … } static void clk_core_free_parent_map(struct clk_core *core) { … } /* Free memory allocated for a struct clk_core */ static void __clk_release(struct kref *ref) { … } static struct clk * __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw) { … } /** * dev_or_parent_of_node() - Get device node of @dev or @dev's parent * @dev: Device to get device node of * * Return: device node pointer of @dev, or the device node pointer of * @dev->parent if dev doesn't have a device node, or NULL if neither * @dev or @dev->parent have a device node. */ static struct device_node *dev_or_parent_of_node(struct device *dev) { … } /** * clk_register - allocate a new clock, register it and return an opaque cookie * @dev: device that is registering this clock * @hw: link to hardware-specific clock data * * clk_register is the *deprecated* interface for populating the clock tree with * new clock nodes. Use clk_hw_register() instead. * * Returns: a pointer to the newly allocated struct clk which * cannot be dereferenced by driver code but may be used in conjunction with the * rest of the clock API. In the event of an error clk_register will return an * error code; drivers must test for an error code after calling clk_register. */ struct clk *clk_register(struct device *dev, struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); /** * clk_hw_register - register a clk_hw and return an error code * @dev: device that is registering this clock * @hw: link to hardware-specific clock data * * clk_hw_register is the primary interface for populating the clock tree with * new clock nodes. It returns an integer equal to zero indicating success or * less than zero indicating failure. Drivers must test for an error code after * calling clk_hw_register(). */ int clk_hw_register(struct device *dev, struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); /* * of_clk_hw_register - register a clk_hw and return an error code * @node: device_node of device that is registering this clock * @hw: link to hardware-specific clock data * * of_clk_hw_register() is the primary interface for populating the clock tree * with new clock nodes when a struct device is not available, but a struct * device_node is. It returns an integer equal to zero indicating success or * less than zero indicating failure. Drivers must test for an error code after * calling of_clk_hw_register(). */ int of_clk_hw_register(struct device_node *node, struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); /* * Empty clk_ops for unregistered clocks. These are used temporarily * after clk_unregister() was called on a clock and until last clock * consumer calls clk_put() and the struct clk object is freed. */ static int clk_nodrv_prepare_enable(struct clk_hw *hw) { … } static void clk_nodrv_disable_unprepare(struct clk_hw *hw) { … } static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { … } static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) { … } static int clk_nodrv_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { … } static const struct clk_ops clk_nodrv_ops = …; static void clk_core_evict_parent_cache_subtree(struct clk_core *root, const struct clk_core *target) { … } /* Remove this clk from all parent caches */ static void clk_core_evict_parent_cache(struct clk_core *core) { … } /** * clk_unregister - unregister a currently registered clock * @clk: clock to unregister */ void clk_unregister(struct clk *clk) { … } EXPORT_SYMBOL_GPL(…); /** * clk_hw_unregister - unregister a currently registered clk_hw * @hw: hardware-specific clock data to unregister */ void clk_hw_unregister(struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); static void devm_clk_unregister_cb(struct device *dev, void *res) { … } static void devm_clk_hw_unregister_cb(struct device *dev, void *res) { … } /** * devm_clk_register - resource managed clk_register() * @dev: device that is registering this clock * @hw: link to hardware-specific clock data * * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead. * * Clocks returned from this function are automatically clk_unregister()ed on * driver detach. See clk_register() for more information. */ struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); /** * devm_clk_hw_register - resource managed clk_hw_register() * @dev: device that is registering this clock * @hw: link to hardware-specific clock data * * Managed clk_hw_register(). Clocks registered by this function are * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register() * for more information. */ int devm_clk_hw_register(struct device *dev, struct clk_hw *hw) { … } EXPORT_SYMBOL_GPL(…); static void devm_clk_release(struct device *dev, void *res) { … } /** * devm_clk_hw_get_clk - resource managed clk_hw_get_clk() * @dev: device that is registering this clock * @hw: clk_hw associated with the clk being consumed * @con_id: connection ID string on device * * Managed clk_hw_get_clk(). Clocks got with this function are * automatically clk_put() on driver detach. See clk_put() * for more information. */ struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw, const char *con_id) { … } EXPORT_SYMBOL_GPL(…); /* * clkdev helpers */ void __clk_put(struct clk *clk) { … } /*** clk rate change notifiers ***/ /** * clk_notifier_register - add a clk rate change notifier * @clk: struct clk * to watch * @nb: struct notifier_block * with callback info * * Request notification when clk's rate changes. This uses an SRCU * notifier because we want it to block and notifier unregistrations are * uncommon. The callbacks associated with the notifier must not * re-enter into the clk framework by calling any top-level clk APIs; * this will cause a nested prepare_lock mutex. * * In all notification cases (pre, post and abort rate change) the original * clock rate is passed to the callback via struct clk_notifier_data.old_rate * and the new frequency is passed via struct clk_notifier_data.new_rate. * * clk_notifier_register() must be called from non-atomic context. * Returns -EINVAL if called with null arguments, -ENOMEM upon * allocation failure; otherwise, passes along the return value of * srcu_notifier_chain_register(). */ int clk_notifier_register(struct clk *clk, struct notifier_block *nb) { … } EXPORT_SYMBOL_GPL(…); /** * clk_notifier_unregister - remove a clk rate change notifier * @clk: struct clk * * @nb: struct notifier_block * with callback info * * Request no further notification for changes to 'clk' and frees memory * allocated in clk_notifier_register. * * Returns -EINVAL if called with null arguments; otherwise, passes * along the return value of srcu_notifier_chain_unregister(). */ int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) { … } EXPORT_SYMBOL_GPL(…); struct clk_notifier_devres { … }; static void devm_clk_notifier_release(struct device *dev, void *res) { … } int devm_clk_notifier_register(struct device *dev, struct clk *clk, struct notifier_block *nb) { … } EXPORT_SYMBOL_GPL(…); #ifdef CONFIG_OF static void clk_core_reparent_orphans(void) { … } /** * struct of_clk_provider - Clock provider registration structure * @link: Entry in global list of clock providers * @node: Pointer to device tree node of clock provider * @get: Get clock callback. Returns NULL or a struct clk for the * given clock specifier * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a * struct clk_hw for the given clock specifier * @data: context pointer to be passed into @get callback */ struct of_clk_provider { … }; extern struct of_device_id __clk_of_table; static const struct of_device_id __clk_of_table_sentinel __used __section(…); static LIST_HEAD(of_clk_providers); static DEFINE_MUTEX(of_clk_mutex); struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, void *data) { … } EXPORT_SYMBOL_GPL(…); struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data) { … } EXPORT_SYMBOL_GPL(…); struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) { … } EXPORT_SYMBOL_GPL(…); struct clk_hw * of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data) { … } EXPORT_SYMBOL_GPL(…); /** * of_clk_add_provider() - Register a clock provider for a node * @np: Device node pointer associated with clock provider * @clk_src_get: callback for decoding clock * @data: context pointer for @clk_src_get callback. * * This function is *deprecated*. Use of_clk_add_hw_provider() instead. */ int of_clk_add_provider(struct device_node *np, struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, void *data), void *data) { … } EXPORT_SYMBOL_GPL(…); /** * of_clk_add_hw_provider() - Register a clock provider for a node * @np: Device node pointer associated with clock provider * @get: callback for decoding clk_hw * @data: context pointer for @get callback. */ int of_clk_add_hw_provider(struct device_node *np, struct clk_hw *(*get)(struct of_phandle_args *clkspec, void *data), void *data) { … } EXPORT_SYMBOL_GPL(…); static void devm_of_clk_release_provider(struct device *dev, void *res) { … } /* * We allow a child device to use its parent device as the clock provider node * for cases like MFD sub-devices where the child device driver wants to use * devm_*() APIs but not list the device in DT as a sub-node. */ static struct device_node *get_clk_provider_node(struct device *dev) { … } /** * devm_of_clk_add_hw_provider() - Managed clk provider node registration * @dev: Device acting as the clock provider (used for DT node and lifetime) * @get: callback for decoding clk_hw * @data: context pointer for @get callback * * Registers clock provider for given device's node. If the device has no DT * node or if the device node lacks of clock provider information (#clock-cells) * then the parent device's node is scanned for this information. If parent node * has the #clock-cells then it is used in registration. Provider is * automatically released at device exit. * * Return: 0 on success or an errno on failure. */ int devm_of_clk_add_hw_provider(struct device *dev, struct clk_hw *(*get)(struct of_phandle_args *clkspec, void *data), void *data) { … } EXPORT_SYMBOL_GPL(…); /** * of_clk_del_provider() - Remove a previously registered clock provider * @np: Device node pointer associated with clock provider */ void of_clk_del_provider(struct device_node *np) { … } EXPORT_SYMBOL_GPL(…); /** * of_parse_clkspec() - Parse a DT clock specifier for a given device node * @np: device node to parse clock specifier from * @index: index of phandle to parse clock out of. If index < 0, @name is used * @name: clock name to find and parse. If name is NULL, the index is used * @out_args: Result of parsing the clock specifier * * Parses a device node's "clocks" and "clock-names" properties to find the * phandle and cells for the index or name that is desired. The resulting clock * specifier is placed into @out_args, or an errno is returned when there's a * parsing error. The @index argument is ignored if @name is non-NULL. * * Example: * * phandle1: clock-controller@1 { * #clock-cells = <2>; * } * * phandle2: clock-controller@2 { * #clock-cells = <1>; * } * * clock-consumer@3 { * clocks = <&phandle1 1 2 &phandle2 3>; * clock-names = "name1", "name2"; * } * * To get a device_node for `clock-controller@2' node you may call this * function a few different ways: * * of_parse_clkspec(clock-consumer@3, -1, "name2", &args); * of_parse_clkspec(clock-consumer@3, 1, NULL, &args); * of_parse_clkspec(clock-consumer@3, 1, "name2", &args); * * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in * the "clock-names" property of @np. */ static int of_parse_clkspec(const struct device_node *np, int index, const char *name, struct of_phandle_args *out_args) { … } static struct clk_hw * __of_clk_get_hw_from_provider(struct of_clk_provider *provider, struct of_phandle_args *clkspec) { … } static struct clk_hw * of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec) { … } /** * of_clk_get_from_provider() - Lookup a clock from a clock provider * @clkspec: pointer to a clock specifier data structure * * This function looks up a struct clk from the registered list of clock * providers, an input is a clock specifier data structure as returned * from the of_parse_phandle_with_args() function call. */ struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) { … } EXPORT_SYMBOL_GPL(…); struct clk_hw *of_clk_get_hw(struct device_node *np, int index, const char *con_id) { … } static struct clk *__of_clk_get(struct device_node *np, int index, const char *dev_id, const char *con_id) { … } struct clk *of_clk_get(struct device_node *np, int index) { … } EXPORT_SYMBOL(…); /** * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node * @np: pointer to clock consumer node * @name: name of consumer's clock input, or NULL for the first clock reference * * This function parses the clocks and clock-names properties, * and uses them to look up the struct clk from the registered list of clock * providers. */ struct clk *of_clk_get_by_name(struct device_node *np, const char *name) { … } EXPORT_SYMBOL(…); /** * of_clk_get_parent_count() - Count the number of clocks a device node has * @np: device node to count * * Returns: The number of clocks that are possible parents of this node */ unsigned int of_clk_get_parent_count(const struct device_node *np) { … } EXPORT_SYMBOL_GPL(…); const char *of_clk_get_parent_name(const struct device_node *np, int index) { … } EXPORT_SYMBOL_GPL(…); /** * of_clk_parent_fill() - Fill @parents with names of @np's parents and return * number of parents * @np: Device node pointer associated with clock provider * @parents: pointer to char array that hold the parents' names * @size: size of the @parents array * * Return: number of parents for the clock node. */ int of_clk_parent_fill(struct device_node *np, const char **parents, unsigned int size) { … } EXPORT_SYMBOL_GPL(…); struct clock_provider { … }; /* * This function looks for a parent clock. If there is one, then it * checks that the provider for this parent clock was initialized, in * this case the parent clock will be ready. */ static int parent_ready(struct device_node *np) { … } /** * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree * @np: Device node pointer associated with clock provider * @index: clock index * @flags: pointer to top-level framework flags * * Detects if the clock-critical property exists and, if so, sets the * corresponding CLK_IS_CRITICAL flag. * * Do not use this function. It exists only for legacy Device Tree * bindings, such as the one-clock-per-node style that are outdated. * Those bindings typically put all clock data into .dts and the Linux * driver has no clock data, thus making it impossible to set this flag * correctly from the driver. Only those drivers may call * of_clk_detect_critical from their setup functions. * * Return: error code or zero on success */ int of_clk_detect_critical(struct device_node *np, int index, unsigned long *flags) { … } /** * of_clk_init() - Scan and init clock providers from the DT * @matches: array of compatible values and init functions for providers. * * This function scans the device tree for matching clock providers * and calls their initialization functions. It also does it by trying * to follow the dependencies. */ void __init of_clk_init(const struct of_device_id *matches) { … } #endif
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