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- // 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);
- static const struct hlist_head *all_lists[] = {
- &clk_root_list,
- &clk_orphan_list,
- NULL,
- };
- /*** private data structures ***/
- struct clk_parent_map {
- const struct clk_hw *hw;
- struct clk_core *core;
- const char *fw_name;
- const char *name;
- int index;
- };
- struct clk_core {
- const char *name;
- const struct clk_ops *ops;
- struct clk_hw *hw;
- struct module *owner;
- struct device *dev;
- struct device_node *of_node;
- struct clk_core *parent;
- struct clk_parent_map *parents;
- u8 num_parents;
- u8 new_parent_index;
- unsigned long rate;
- unsigned long req_rate;
- unsigned long new_rate;
- struct clk_core *new_parent;
- struct clk_core *new_child;
- unsigned long flags;
- bool orphan;
- bool rpm_enabled;
- bool need_sync;
- bool boot_enabled;
- unsigned int enable_count;
- unsigned int prepare_count;
- unsigned int protect_count;
- unsigned long min_rate;
- unsigned long max_rate;
- unsigned long accuracy;
- int phase;
- struct clk_duty duty;
- struct hlist_head children;
- struct hlist_node child_node;
- struct hlist_head clks;
- unsigned int notifier_count;
- #ifdef CONFIG_DEBUG_FS
- struct dentry *dentry;
- struct hlist_node debug_node;
- #endif
- struct kref ref;
- };
- #define CREATE_TRACE_POINTS
- #include <trace/events/clk.h>
- struct clk {
- struct clk_core *core;
- struct device *dev;
- const char *dev_id;
- const char *con_id;
- unsigned long min_rate;
- unsigned long max_rate;
- unsigned int exclusive_count;
- struct hlist_node clks_node;
- };
- /*** runtime pm ***/
- static int clk_pm_runtime_get(struct clk_core *core)
- {
- if (!core->rpm_enabled)
- return 0;
- return pm_runtime_resume_and_get(core->dev);
- }
- static void clk_pm_runtime_put(struct clk_core *core)
- {
- if (!core->rpm_enabled)
- return;
- pm_runtime_put_sync(core->dev);
- }
- /*** locking ***/
- static void clk_prepare_lock(void)
- {
- if (!mutex_trylock(&prepare_lock)) {
- if (prepare_owner == current) {
- prepare_refcnt++;
- return;
- }
- mutex_lock(&prepare_lock);
- }
- WARN_ON_ONCE(prepare_owner != NULL);
- WARN_ON_ONCE(prepare_refcnt != 0);
- prepare_owner = current;
- prepare_refcnt = 1;
- }
- static void clk_prepare_unlock(void)
- {
- WARN_ON_ONCE(prepare_owner != current);
- WARN_ON_ONCE(prepare_refcnt == 0);
- if (--prepare_refcnt)
- return;
- prepare_owner = NULL;
- mutex_unlock(&prepare_lock);
- }
- static unsigned long clk_enable_lock(void)
- __acquires(enable_lock)
- {
- unsigned long flags;
- /*
- * On UP systems, spin_trylock_irqsave() always returns true, even if
- * we already hold the lock. So, in that case, we rely only on
- * reference counting.
- */
- if (!IS_ENABLED(CONFIG_SMP) ||
- !spin_trylock_irqsave(&enable_lock, flags)) {
- if (enable_owner == current) {
- enable_refcnt++;
- __acquire(enable_lock);
- if (!IS_ENABLED(CONFIG_SMP))
- local_save_flags(flags);
- return flags;
- }
- spin_lock_irqsave(&enable_lock, flags);
- }
- WARN_ON_ONCE(enable_owner != NULL);
- WARN_ON_ONCE(enable_refcnt != 0);
- enable_owner = current;
- enable_refcnt = 1;
- return flags;
- }
- static void clk_enable_unlock(unsigned long flags)
- __releases(enable_lock)
- {
- WARN_ON_ONCE(enable_owner != current);
- WARN_ON_ONCE(enable_refcnt == 0);
- if (--enable_refcnt) {
- __release(enable_lock);
- return;
- }
- enable_owner = NULL;
- spin_unlock_irqrestore(&enable_lock, flags);
- }
- static bool clk_core_rate_is_protected(struct clk_core *core)
- {
- return core->protect_count;
- }
- static bool clk_core_is_prepared(struct clk_core *core)
- {
- bool ret = false;
- /*
- * .is_prepared is optional for clocks that can prepare
- * fall back to software usage counter if it is missing
- */
- if (!core->ops->is_prepared)
- return core->prepare_count;
- if (!clk_pm_runtime_get(core)) {
- ret = core->ops->is_prepared(core->hw);
- clk_pm_runtime_put(core);
- }
- return ret;
- }
- static bool clk_core_is_enabled(struct clk_core *core)
- {
- bool ret = false;
- /*
- * .is_enabled is only mandatory for clocks that gate
- * fall back to software usage counter if .is_enabled is missing
- */
- if (!core->ops->is_enabled)
- return core->enable_count;
- /*
- * Check if clock controller's device is runtime active before
- * calling .is_enabled callback. If not, assume that clock is
- * disabled, because we might be called from atomic context, from
- * which pm_runtime_get() is not allowed.
- * This function is called mainly from clk_disable_unused_subtree,
- * which ensures proper runtime pm activation of controller before
- * taking enable spinlock, but the below check is needed if one tries
- * to call it from other places.
- */
- if (core->rpm_enabled) {
- pm_runtime_get_noresume(core->dev);
- if (!pm_runtime_active(core->dev)) {
- ret = false;
- goto done;
- }
- }
- ret = core->ops->is_enabled(core->hw);
- done:
- if (core->rpm_enabled)
- pm_runtime_put(core->dev);
- return ret;
- }
- /*** helper functions ***/
- const char *__clk_get_name(const struct clk *clk)
- {
- return !clk ? NULL : clk->core->name;
- }
- EXPORT_SYMBOL_GPL(__clk_get_name);
- const char *clk_hw_get_name(const struct clk_hw *hw)
- {
- return hw->core->name;
- }
- EXPORT_SYMBOL_GPL(clk_hw_get_name);
- struct clk_hw *__clk_get_hw(struct clk *clk)
- {
- return !clk ? NULL : clk->core->hw;
- }
- EXPORT_SYMBOL_GPL(__clk_get_hw);
- unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
- {
- return hw->core->num_parents;
- }
- EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
- struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
- {
- return hw->core->parent ? hw->core->parent->hw : NULL;
- }
- EXPORT_SYMBOL_GPL(clk_hw_get_parent);
- static struct clk_core *__clk_lookup_subtree(const char *name,
- struct clk_core *core)
- {
- struct clk_core *child;
- struct clk_core *ret;
- if (!strcmp(core->name, name))
- return core;
- hlist_for_each_entry(child, &core->children, child_node) {
- ret = __clk_lookup_subtree(name, child);
- if (ret)
- return ret;
- }
- return NULL;
- }
- static struct clk_core *clk_core_lookup(const char *name)
- {
- struct clk_core *root_clk;
- struct clk_core *ret;
- if (!name)
- return NULL;
- /* search the 'proper' clk tree first */
- hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
- ret = __clk_lookup_subtree(name, root_clk);
- if (ret)
- return ret;
- }
- /* if not found, then search the orphan tree */
- hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
- ret = __clk_lookup_subtree(name, root_clk);
- if (ret)
- return ret;
- }
- return NULL;
- }
- #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)
- {
- const char *name = core->parents[p_index].fw_name;
- int index = core->parents[p_index].index;
- struct clk_hw *hw = ERR_PTR(-ENOENT);
- struct device *dev = core->dev;
- const char *dev_id = dev ? dev_name(dev) : NULL;
- struct device_node *np = core->of_node;
- struct of_phandle_args clkspec;
- if (np && (name || index >= 0) &&
- !of_parse_clkspec(np, index, name, &clkspec)) {
- hw = of_clk_get_hw_from_clkspec(&clkspec);
- of_node_put(clkspec.np);
- } else if (name) {
- /*
- * If the DT search above couldn't find the provider fallback to
- * looking up via clkdev based clk_lookups.
- */
- hw = clk_find_hw(dev_id, name);
- }
- if (IS_ERR(hw))
- return ERR_CAST(hw);
- return hw->core;
- }
- static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
- {
- struct clk_parent_map *entry = &core->parents[index];
- struct clk_core *parent;
- if (entry->hw) {
- parent = entry->hw->core;
- } else {
- parent = clk_core_get(core, index);
- if (PTR_ERR(parent) == -ENOENT && entry->name)
- parent = clk_core_lookup(entry->name);
- }
- /*
- * We have a direct reference but it isn't registered yet?
- * Orphan it and let clk_reparent() update the orphan status
- * when the parent is registered.
- */
- if (!parent)
- parent = ERR_PTR(-EPROBE_DEFER);
- /* Only cache it if it's not an error */
- if (!IS_ERR(parent))
- entry->core = parent;
- }
- static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
- u8 index)
- {
- if (!core || index >= core->num_parents || !core->parents)
- return NULL;
- if (!core->parents[index].core)
- clk_core_fill_parent_index(core, index);
- return core->parents[index].core;
- }
- struct clk_hw *
- clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
- {
- struct clk_core *parent;
- parent = clk_core_get_parent_by_index(hw->core, index);
- return !parent ? NULL : parent->hw;
- }
- EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
- unsigned int __clk_get_enable_count(struct clk *clk)
- {
- return !clk ? 0 : clk->core->enable_count;
- }
- static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
- {
- if (!core)
- return 0;
- if (!core->num_parents || core->parent)
- return core->rate;
- /*
- * Clk must have a parent because num_parents > 0 but the parent isn't
- * known yet. Best to return 0 as the rate of this clk until we can
- * properly recalc the rate based on the parent's rate.
- */
- return 0;
- }
- unsigned long clk_hw_get_rate(const struct clk_hw *hw)
- {
- return clk_core_get_rate_nolock(hw->core);
- }
- EXPORT_SYMBOL_GPL(clk_hw_get_rate);
- static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
- {
- if (!core)
- return 0;
- return core->accuracy;
- }
- unsigned long clk_hw_get_flags(const struct clk_hw *hw)
- {
- return hw->core->flags;
- }
- EXPORT_SYMBOL_GPL(clk_hw_get_flags);
- bool clk_hw_is_prepared(const struct clk_hw *hw)
- {
- return clk_core_is_prepared(hw->core);
- }
- EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
- bool clk_hw_rate_is_protected(const struct clk_hw *hw)
- {
- return clk_core_rate_is_protected(hw->core);
- }
- EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
- bool clk_hw_is_enabled(const struct clk_hw *hw)
- {
- return clk_core_is_enabled(hw->core);
- }
- EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
- bool __clk_is_enabled(struct clk *clk)
- {
- if (!clk)
- return false;
- return clk_core_is_enabled(clk->core);
- }
- EXPORT_SYMBOL_GPL(__clk_is_enabled);
- static bool mux_is_better_rate(unsigned long rate, unsigned long now,
- unsigned long best, unsigned long flags)
- {
- if (flags & CLK_MUX_ROUND_CLOSEST)
- return abs(now - rate) < abs(best - rate);
- return now <= rate && now > best;
- }
- 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)
- {
- struct clk_core *tmp;
- unsigned int i;
- /* Optimize for the case where the parent is already the parent. */
- if (core->parent == parent)
- return true;
- for (i = 0; i < core->num_parents; i++) {
- tmp = clk_core_get_parent_by_index(core, i);
- if (!tmp)
- continue;
- if (tmp == parent)
- return true;
- }
- return false;
- }
- 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)
- {
- if (WARN_ON(!clk_core_has_parent(core, parent)))
- return;
- clk_core_init_rate_req(parent, req, parent_rate);
- if (req->min_rate < old_req->min_rate)
- req->min_rate = old_req->min_rate;
- if (req->max_rate > old_req->max_rate)
- req->max_rate = old_req->max_rate;
- }
- int clk_mux_determine_rate_flags(struct clk_hw *hw,
- struct clk_rate_request *req,
- unsigned long flags)
- {
- struct clk_core *core = hw->core, *parent, *best_parent = NULL;
- int i, num_parents, ret;
- unsigned long best = 0;
- /* if NO_REPARENT flag set, pass through to current parent */
- if (core->flags & CLK_SET_RATE_NO_REPARENT) {
- parent = core->parent;
- if (core->flags & CLK_SET_RATE_PARENT) {
- struct clk_rate_request parent_req;
- if (!parent) {
- req->rate = 0;
- return 0;
- }
- clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
- ret = clk_core_round_rate_nolock(parent, &parent_req);
- if (ret)
- return ret;
- best = parent_req.rate;
- } else if (parent) {
- best = clk_core_get_rate_nolock(parent);
- } else {
- best = clk_core_get_rate_nolock(core);
- }
- goto out;
- }
- /* find the parent that can provide the fastest rate <= rate */
- num_parents = core->num_parents;
- for (i = 0; i < num_parents; i++) {
- unsigned long parent_rate;
- parent = clk_core_get_parent_by_index(core, i);
- if (!parent)
- continue;
- if (core->flags & CLK_SET_RATE_PARENT) {
- struct clk_rate_request parent_req;
- clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
- ret = clk_core_round_rate_nolock(parent, &parent_req);
- if (ret)
- continue;
- parent_rate = parent_req.rate;
- } else {
- parent_rate = clk_core_get_rate_nolock(parent);
- }
- if (mux_is_better_rate(req->rate, parent_rate,
- best, flags)) {
- best_parent = parent;
- best = parent_rate;
- }
- }
- if (!best_parent)
- return -EINVAL;
- out:
- if (best_parent)
- req->best_parent_hw = best_parent->hw;
- req->best_parent_rate = best;
- req->rate = best;
- return 0;
- }
- EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
- struct clk *__clk_lookup(const char *name)
- {
- struct clk_core *core = clk_core_lookup(name);
- return !core ? NULL : core->hw->clk;
- }
- static void clk_core_get_boundaries(struct clk_core *core,
- unsigned long *min_rate,
- unsigned long *max_rate)
- {
- struct clk *clk_user;
- lockdep_assert_held(&prepare_lock);
- *min_rate = core->min_rate;
- *max_rate = core->max_rate;
- hlist_for_each_entry(clk_user, &core->clks, clks_node)
- *min_rate = max(*min_rate, clk_user->min_rate);
- hlist_for_each_entry(clk_user, &core->clks, clks_node)
- *max_rate = min(*max_rate, clk_user->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)
- {
- clk_core_get_boundaries(hw->core, min_rate, max_rate);
- }
- EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
- static bool clk_core_check_boundaries(struct clk_core *core,
- unsigned long min_rate,
- unsigned long max_rate)
- {
- struct clk *user;
- lockdep_assert_held(&prepare_lock);
- if (min_rate > core->max_rate || max_rate < core->min_rate)
- return false;
- hlist_for_each_entry(user, &core->clks, clks_node)
- if (min_rate > user->max_rate || max_rate < user->min_rate)
- return false;
- return true;
- }
- void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
- unsigned long max_rate)
- {
- hw->core->min_rate = min_rate;
- hw->core->max_rate = max_rate;
- }
- EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
- /*
- * __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)
- {
- return clk_mux_determine_rate_flags(hw, req, 0);
- }
- EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
- int __clk_mux_determine_rate_closest(struct clk_hw *hw,
- struct clk_rate_request *req)
- {
- return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
- }
- EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
- /*** clk api ***/
- static void clk_core_rate_unprotect(struct clk_core *core)
- {
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return;
- if (WARN(core->protect_count == 0,
- "%s already unprotected\n", core->name))
- return;
- if (--core->protect_count > 0)
- return;
- clk_core_rate_unprotect(core->parent);
- }
- static int clk_core_rate_nuke_protect(struct clk_core *core)
- {
- int ret;
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return -EINVAL;
- if (core->protect_count == 0)
- return 0;
- ret = core->protect_count;
- core->protect_count = 1;
- clk_core_rate_unprotect(core);
- return ret;
- }
- /**
- * 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)
- {
- if (!clk)
- return;
- clk_prepare_lock();
- /*
- * if there is something wrong with this consumer protect count, stop
- * here before messing with the provider
- */
- if (WARN_ON(clk->exclusive_count <= 0))
- goto out;
- clk_core_rate_unprotect(clk->core);
- clk->exclusive_count--;
- out:
- clk_prepare_unlock();
- }
- EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
- static void clk_core_rate_protect(struct clk_core *core)
- {
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return;
- if (core->protect_count == 0)
- clk_core_rate_protect(core->parent);
- core->protect_count++;
- }
- static void clk_core_rate_restore_protect(struct clk_core *core, int count)
- {
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return;
- if (count == 0)
- return;
- clk_core_rate_protect(core);
- core->protect_count = 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)
- {
- if (!clk)
- return 0;
- clk_prepare_lock();
- clk_core_rate_protect(clk->core);
- clk->exclusive_count++;
- clk_prepare_unlock();
- return 0;
- }
- EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
- static void clk_core_unprepare(struct clk_core *core)
- {
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return;
- if (WARN(core->prepare_count == 0,
- "%s already unprepared\n", core->name))
- return;
- if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
- "Unpreparing critical %s\n", core->name))
- return;
- if (core->flags & CLK_SET_RATE_GATE)
- clk_core_rate_unprotect(core);
- if (--core->prepare_count > 0)
- return;
- WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
- trace_clk_unprepare(core);
- if (core->ops->unprepare)
- core->ops->unprepare(core->hw);
- trace_clk_unprepare_complete(core);
- clk_core_unprepare(core->parent);
- clk_pm_runtime_put(core);
- }
- static void clk_core_unprepare_lock(struct clk_core *core)
- {
- clk_prepare_lock();
- clk_core_unprepare(core);
- clk_prepare_unlock();
- }
- /**
- * 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)
- {
- if (IS_ERR_OR_NULL(clk))
- return;
- clk_core_unprepare_lock(clk->core);
- }
- EXPORT_SYMBOL_GPL(clk_unprepare);
- static int clk_core_prepare(struct clk_core *core)
- {
- int ret = 0;
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return 0;
- if (core->prepare_count == 0) {
- ret = clk_pm_runtime_get(core);
- if (ret)
- return ret;
- ret = clk_core_prepare(core->parent);
- if (ret)
- goto runtime_put;
- trace_clk_prepare(core);
- if (core->ops->prepare)
- ret = core->ops->prepare(core->hw);
- trace_clk_prepare_complete(core);
- if (ret)
- goto unprepare;
- }
- core->prepare_count++;
- /*
- * CLK_SET_RATE_GATE is a special case of clock protection
- * Instead of a consumer claiming exclusive rate control, it is
- * actually the provider which prevents any consumer from making any
- * operation which could result in a rate change or rate glitch while
- * the clock is prepared.
- */
- if (core->flags & CLK_SET_RATE_GATE)
- clk_core_rate_protect(core);
- return 0;
- unprepare:
- clk_core_unprepare(core->parent);
- runtime_put:
- clk_pm_runtime_put(core);
- return ret;
- }
- static int clk_core_prepare_lock(struct clk_core *core)
- {
- int ret;
- clk_prepare_lock();
- ret = clk_core_prepare(core);
- clk_prepare_unlock();
- return ret;
- }
- /**
- * 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)
- {
- if (!clk)
- return 0;
- return clk_core_prepare_lock(clk->core);
- }
- EXPORT_SYMBOL_GPL(clk_prepare);
- static void clk_core_disable(struct clk_core *core)
- {
- lockdep_assert_held(&enable_lock);
- if (!core)
- return;
- if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
- return;
- if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
- "Disabling critical %s\n", core->name))
- return;
- if (--core->enable_count > 0)
- return;
- trace_clk_disable_rcuidle(core);
- if (core->ops->disable)
- core->ops->disable(core->hw);
- trace_clk_disable_complete_rcuidle(core);
- clk_core_disable(core->parent);
- }
- static void clk_core_disable_lock(struct clk_core *core)
- {
- unsigned long flags;
- flags = clk_enable_lock();
- clk_core_disable(core);
- clk_enable_unlock(flags);
- }
- /**
- * 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)
- {
- if (IS_ERR_OR_NULL(clk))
- return;
- clk_core_disable_lock(clk->core);
- }
- EXPORT_SYMBOL_GPL(clk_disable);
- static int clk_core_enable(struct clk_core *core)
- {
- int ret = 0;
- lockdep_assert_held(&enable_lock);
- if (!core)
- return 0;
- if (WARN(core->prepare_count == 0,
- "Enabling unprepared %s\n", core->name))
- return -ESHUTDOWN;
- if (core->enable_count == 0) {
- ret = clk_core_enable(core->parent);
- if (ret)
- return ret;
- trace_clk_enable_rcuidle(core);
- if (core->ops->enable)
- ret = core->ops->enable(core->hw);
- trace_clk_enable_complete_rcuidle(core);
- if (ret) {
- clk_core_disable(core->parent);
- return ret;
- }
- }
- core->enable_count++;
- return 0;
- }
- static int clk_core_enable_lock(struct clk_core *core)
- {
- unsigned long flags;
- int ret;
- flags = clk_enable_lock();
- ret = clk_core_enable(core);
- clk_enable_unlock(flags);
- return ret;
- }
- /**
- * 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)
- {
- struct clk_core *core = hw->core;
- if (core->enable_count)
- core->ops->enable(hw);
- else
- core->ops->disable(hw);
- }
- EXPORT_SYMBOL_GPL(clk_gate_restore_context);
- static int clk_core_save_context(struct clk_core *core)
- {
- struct clk_core *child;
- int ret = 0;
- hlist_for_each_entry(child, &core->children, child_node) {
- ret = clk_core_save_context(child);
- if (ret < 0)
- return ret;
- }
- if (core->ops && core->ops->save_context)
- ret = core->ops->save_context(core->hw);
- return ret;
- }
- static void clk_core_restore_context(struct clk_core *core)
- {
- struct clk_core *child;
- if (core->ops && core->ops->restore_context)
- core->ops->restore_context(core->hw);
- hlist_for_each_entry(child, &core->children, child_node)
- clk_core_restore_context(child);
- }
- /**
- * 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)
- {
- struct clk_core *clk;
- int ret;
- hlist_for_each_entry(clk, &clk_root_list, child_node) {
- ret = clk_core_save_context(clk);
- if (ret < 0)
- return ret;
- }
- hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
- ret = clk_core_save_context(clk);
- if (ret < 0)
- return ret;
- }
- return 0;
- }
- EXPORT_SYMBOL_GPL(clk_save_context);
- /**
- * clk_restore_context - restore clock context after poweroff
- *
- * Restore the saved clock context upon resume.
- *
- */
- void clk_restore_context(void)
- {
- struct clk_core *core;
- hlist_for_each_entry(core, &clk_root_list, child_node)
- clk_core_restore_context(core);
- hlist_for_each_entry(core, &clk_orphan_list, child_node)
- clk_core_restore_context(core);
- }
- EXPORT_SYMBOL_GPL(clk_restore_context);
- /**
- * 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)
- {
- if (!clk)
- return 0;
- return clk_core_enable_lock(clk->core);
- }
- EXPORT_SYMBOL_GPL(clk_enable);
- /**
- * 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)
- {
- return clk && !(clk->core->ops->enable && clk->core->ops->disable);
- }
- EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
- static int clk_core_prepare_enable(struct clk_core *core)
- {
- int ret;
- ret = clk_core_prepare_lock(core);
- if (ret)
- return ret;
- ret = clk_core_enable_lock(core);
- if (ret)
- clk_core_unprepare_lock(core);
- return ret;
- }
- static void clk_core_disable_unprepare(struct clk_core *core)
- {
- clk_core_disable_lock(core);
- clk_core_unprepare_lock(core);
- }
- static void __init clk_unprepare_unused_subtree(struct clk_core *core)
- {
- struct clk_core *child;
- lockdep_assert_held(&prepare_lock);
- hlist_for_each_entry(child, &core->children, child_node)
- clk_unprepare_unused_subtree(child);
- if (dev_has_sync_state(core->dev) &&
- !(core->flags & CLK_DONT_HOLD_STATE))
- return;
- if (core->prepare_count)
- return;
- if (core->flags & CLK_IGNORE_UNUSED)
- return;
- if (clk_pm_runtime_get(core))
- return;
- if (clk_core_is_prepared(core)) {
- trace_clk_unprepare(core);
- if (core->ops->unprepare_unused)
- core->ops->unprepare_unused(core->hw);
- else if (core->ops->unprepare)
- core->ops->unprepare(core->hw);
- trace_clk_unprepare_complete(core);
- }
- clk_pm_runtime_put(core);
- }
- static void __init clk_disable_unused_subtree(struct clk_core *core)
- {
- struct clk_core *child;
- unsigned long flags;
- lockdep_assert_held(&prepare_lock);
- hlist_for_each_entry(child, &core->children, child_node)
- clk_disable_unused_subtree(child);
- if (dev_has_sync_state(core->dev) &&
- !(core->flags & CLK_DONT_HOLD_STATE))
- return;
- if (core->flags & CLK_OPS_PARENT_ENABLE)
- clk_core_prepare_enable(core->parent);
- if (clk_pm_runtime_get(core))
- goto unprepare_out;
- flags = clk_enable_lock();
- if (core->enable_count)
- goto unlock_out;
- if (core->flags & CLK_IGNORE_UNUSED)
- goto unlock_out;
- /*
- * some gate clocks have special needs during the disable-unused
- * sequence. call .disable_unused if available, otherwise fall
- * back to .disable
- */
- if (clk_core_is_enabled(core)) {
- trace_clk_disable(core);
- if (core->ops->disable_unused)
- core->ops->disable_unused(core->hw);
- else if (core->ops->disable)
- core->ops->disable(core->hw);
- trace_clk_disable_complete(core);
- }
- unlock_out:
- clk_enable_unlock(flags);
- clk_pm_runtime_put(core);
- unprepare_out:
- if (core->flags & CLK_OPS_PARENT_ENABLE)
- clk_core_disable_unprepare(core->parent);
- }
- static bool clk_ignore_unused __initdata;
- static int __init clk_ignore_unused_setup(char *__unused)
- {
- clk_ignore_unused = true;
- return 1;
- }
- __setup("clk_ignore_unused", clk_ignore_unused_setup);
- static int __init clk_disable_unused(void)
- {
- struct clk_core *core;
- if (clk_ignore_unused) {
- pr_warn("clk: Not disabling unused clocks\n");
- return 0;
- }
- clk_prepare_lock();
- hlist_for_each_entry(core, &clk_root_list, child_node)
- clk_disable_unused_subtree(core);
- hlist_for_each_entry(core, &clk_orphan_list, child_node)
- clk_disable_unused_subtree(core);
- hlist_for_each_entry(core, &clk_root_list, child_node)
- clk_unprepare_unused_subtree(core);
- hlist_for_each_entry(core, &clk_orphan_list, child_node)
- clk_unprepare_unused_subtree(core);
- clk_prepare_unlock();
- return 0;
- }
- late_initcall_sync(clk_disable_unused);
- static void clk_unprepare_disable_dev_subtree(struct clk_core *core,
- struct device *dev)
- {
- struct clk_core *child;
- lockdep_assert_held(&prepare_lock);
- hlist_for_each_entry(child, &core->children, child_node)
- clk_unprepare_disable_dev_subtree(child, dev);
- if (core->dev != dev || !core->need_sync)
- return;
- clk_core_disable_unprepare(core);
- }
- void clk_sync_state(struct device *dev)
- {
- struct clk_core *core;
- clk_prepare_lock();
- hlist_for_each_entry(core, &clk_root_list, child_node)
- clk_unprepare_disable_dev_subtree(core, dev);
- hlist_for_each_entry(core, &clk_orphan_list, child_node)
- clk_unprepare_disable_dev_subtree(core, dev);
- clk_prepare_unlock();
- }
- EXPORT_SYMBOL_GPL(clk_sync_state);
- static int clk_core_determine_round_nolock(struct clk_core *core,
- struct clk_rate_request *req)
- {
- long rate;
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return 0;
- /*
- * Some clock providers hand-craft their clk_rate_requests and
- * might not fill min_rate and max_rate.
- *
- * If it's the case, clamping the rate is equivalent to setting
- * the rate to 0 which is bad. Skip the clamping but complain so
- * that it gets fixed, hopefully.
- */
- if (!req->min_rate && !req->max_rate)
- pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
- __func__, core->name);
- else
- req->rate = clamp(req->rate, req->min_rate, req->max_rate);
- /*
- * At this point, core protection will be disabled
- * - if the provider is not protected at all
- * - if the calling consumer is the only one which has exclusivity
- * over the provider
- */
- if (clk_core_rate_is_protected(core)) {
- req->rate = core->rate;
- } else if (core->ops->determine_rate) {
- return core->ops->determine_rate(core->hw, req);
- } else if (core->ops->round_rate) {
- rate = core->ops->round_rate(core->hw, req->rate,
- &req->best_parent_rate);
- if (rate < 0)
- return rate;
- req->rate = rate;
- } else {
- return -EINVAL;
- }
- return 0;
- }
- static void clk_core_init_rate_req(struct clk_core * const core,
- struct clk_rate_request *req,
- unsigned long rate)
- {
- struct clk_core *parent;
- if (WARN_ON(!req))
- return;
- memset(req, 0, sizeof(*req));
- req->max_rate = ULONG_MAX;
- if (!core)
- return;
- req->rate = rate;
- clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
- parent = core->parent;
- if (parent) {
- req->best_parent_hw = parent->hw;
- req->best_parent_rate = parent->rate;
- } else {
- req->best_parent_hw = NULL;
- req->best_parent_rate = 0;
- }
- }
- /**
- * 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)
- {
- if (WARN_ON(!hw || !req))
- return;
- clk_core_init_rate_req(hw->core, req, rate);
- }
- EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
- /**
- * 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)
- {
- if (WARN_ON(!hw || !old_req || !parent || !req))
- return;
- clk_core_forward_rate_req(hw->core, old_req,
- parent->core, req,
- parent_rate);
- }
- EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);
- static bool clk_core_can_round(struct clk_core * const core)
- {
- return core->ops->determine_rate || core->ops->round_rate;
- }
- static int clk_core_round_rate_nolock(struct clk_core *core,
- struct clk_rate_request *req)
- {
- int ret;
- lockdep_assert_held(&prepare_lock);
- if (!core) {
- req->rate = 0;
- return 0;
- }
- if (clk_core_can_round(core))
- return clk_core_determine_round_nolock(core, req);
- if (core->flags & CLK_SET_RATE_PARENT) {
- struct clk_rate_request parent_req;
- clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
- ret = clk_core_round_rate_nolock(core->parent, &parent_req);
- if (ret)
- return ret;
- req->best_parent_rate = parent_req.rate;
- req->rate = parent_req.rate;
- return 0;
- }
- req->rate = core->rate;
- return 0;
- }
- /**
- * __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)
- {
- if (!hw) {
- req->rate = 0;
- return 0;
- }
- return clk_core_round_rate_nolock(hw->core, req);
- }
- EXPORT_SYMBOL_GPL(__clk_determine_rate);
- /**
- * 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)
- {
- int ret;
- struct clk_rate_request req;
- clk_core_init_rate_req(hw->core, &req, rate);
- ret = clk_core_round_rate_nolock(hw->core, &req);
- if (ret)
- return 0;
- return req.rate;
- }
- EXPORT_SYMBOL_GPL(clk_hw_round_rate);
- /**
- * 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)
- {
- struct clk_rate_request req;
- int ret;
- if (!clk)
- return 0;
- clk_prepare_lock();
- if (clk->exclusive_count)
- clk_core_rate_unprotect(clk->core);
- clk_core_init_rate_req(clk->core, &req, rate);
- ret = clk_core_round_rate_nolock(clk->core, &req);
- if (clk->exclusive_count)
- clk_core_rate_protect(clk->core);
- clk_prepare_unlock();
- if (ret)
- return ret;
- return req.rate;
- }
- EXPORT_SYMBOL_GPL(clk_round_rate);
- /**
- * __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)
- {
- struct clk_notifier *cn;
- struct clk_notifier_data cnd;
- int ret = NOTIFY_DONE;
- cnd.old_rate = old_rate;
- cnd.new_rate = new_rate;
- list_for_each_entry(cn, &clk_notifier_list, node) {
- if (cn->clk->core == core) {
- cnd.clk = cn->clk;
- ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
- &cnd);
- if (ret & NOTIFY_STOP_MASK)
- return ret;
- }
- }
- return ret;
- }
- /**
- * __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)
- {
- unsigned long parent_accuracy = 0;
- struct clk_core *child;
- lockdep_assert_held(&prepare_lock);
- if (core->parent)
- parent_accuracy = core->parent->accuracy;
- if (core->ops->recalc_accuracy)
- core->accuracy = core->ops->recalc_accuracy(core->hw,
- parent_accuracy);
- else
- core->accuracy = parent_accuracy;
- hlist_for_each_entry(child, &core->children, child_node)
- __clk_recalc_accuracies(child);
- }
- static long clk_core_get_accuracy_recalc(struct clk_core *core)
- {
- if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
- __clk_recalc_accuracies(core);
- return clk_core_get_accuracy_no_lock(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)
- {
- long accuracy;
- if (!clk)
- return 0;
- clk_prepare_lock();
- accuracy = clk_core_get_accuracy_recalc(clk->core);
- clk_prepare_unlock();
- return accuracy;
- }
- EXPORT_SYMBOL_GPL(clk_get_accuracy);
- static unsigned long clk_recalc(struct clk_core *core,
- unsigned long parent_rate)
- {
- unsigned long rate = parent_rate;
- if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
- rate = core->ops->recalc_rate(core->hw, parent_rate);
- clk_pm_runtime_put(core);
- }
- return 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)
- {
- unsigned long old_rate;
- unsigned long parent_rate = 0;
- struct clk_core *child;
- lockdep_assert_held(&prepare_lock);
- old_rate = core->rate;
- if (core->parent)
- parent_rate = core->parent->rate;
- core->rate = clk_recalc(core, parent_rate);
- if (update_req)
- core->req_rate = core->rate;
- /*
- * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
- * & ABORT_RATE_CHANGE notifiers
- */
- if (core->notifier_count && msg)
- __clk_notify(core, msg, old_rate, core->rate);
- hlist_for_each_entry(child, &core->children, child_node)
- __clk_recalc_rates(child, update_req, msg);
- }
- static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
- {
- if (core && (core->flags & CLK_GET_RATE_NOCACHE))
- __clk_recalc_rates(core, false, 0);
- return clk_core_get_rate_nolock(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)
- {
- unsigned long rate;
- if (!clk)
- return 0;
- clk_prepare_lock();
- rate = clk_core_get_rate_recalc(clk->core);
- clk_prepare_unlock();
- return rate;
- }
- EXPORT_SYMBOL_GPL(clk_get_rate);
- static int clk_fetch_parent_index(struct clk_core *core,
- struct clk_core *parent)
- {
- int i;
- if (!parent)
- return -EINVAL;
- for (i = 0; i < core->num_parents; i++) {
- /* Found it first try! */
- if (core->parents[i].core == parent)
- return i;
- /* Something else is here, so keep looking */
- if (core->parents[i].core)
- continue;
- /* Maybe core hasn't been cached but the hw is all we know? */
- if (core->parents[i].hw) {
- if (core->parents[i].hw == parent->hw)
- break;
- /* Didn't match, but we're expecting a clk_hw */
- continue;
- }
- /* Maybe it hasn't been cached (clk_set_parent() path) */
- if (parent == clk_core_get(core, i))
- break;
- /* Fallback to comparing globally unique names */
- if (core->parents[i].name &&
- !strcmp(parent->name, core->parents[i].name))
- break;
- }
- if (i == core->num_parents)
- return -EINVAL;
- core->parents[i].core = parent;
- return i;
- }
- /**
- * 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)
- {
- struct clk_hw *parent = clk_hw_get_parent(hw);
- if (WARN_ON(parent == NULL))
- return -EINVAL;
- return clk_fetch_parent_index(hw->core, parent->core);
- }
- EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
- static void clk_core_hold_state(struct clk_core *core)
- {
- if (core->need_sync || !core->boot_enabled)
- return;
- if (core->orphan || !dev_has_sync_state(core->dev))
- return;
- if (core->flags & CLK_DONT_HOLD_STATE)
- return;
- core->need_sync = !clk_core_prepare_enable(core);
- }
- static void __clk_core_update_orphan_hold_state(struct clk_core *core)
- {
- struct clk_core *child;
- if (core->orphan)
- return;
- clk_core_hold_state(core);
- hlist_for_each_entry(child, &core->children, child_node)
- __clk_core_update_orphan_hold_state(child);
- }
- /*
- * Update the orphan status of @core and all its children.
- */
- static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
- {
- struct clk_core *child;
- core->orphan = is_orphan;
- hlist_for_each_entry(child, &core->children, child_node)
- clk_core_update_orphan_status(child, is_orphan);
- }
- static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
- {
- bool was_orphan = core->orphan;
- hlist_del(&core->child_node);
- if (new_parent) {
- bool becomes_orphan = new_parent->orphan;
- /* avoid duplicate POST_RATE_CHANGE notifications */
- if (new_parent->new_child == core)
- new_parent->new_child = NULL;
- hlist_add_head(&core->child_node, &new_parent->children);
- if (was_orphan != becomes_orphan)
- clk_core_update_orphan_status(core, becomes_orphan);
- } else {
- hlist_add_head(&core->child_node, &clk_orphan_list);
- if (!was_orphan)
- clk_core_update_orphan_status(core, true);
- }
- core->parent = new_parent;
- }
- static struct clk_core *__clk_set_parent_before(struct clk_core *core,
- struct clk_core *parent)
- {
- unsigned long flags;
- struct clk_core *old_parent = core->parent;
- /*
- * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
- *
- * 2. Migrate prepare state between parents and prevent race with
- * clk_enable().
- *
- * If the clock is not prepared, then a race with
- * clk_enable/disable() is impossible since we already have the
- * prepare lock (future calls to clk_enable() need to be preceded by
- * a clk_prepare()).
- *
- * If the clock is prepared, migrate the prepared state to the new
- * parent and also protect against a race with clk_enable() by
- * forcing the clock and the new parent on. This ensures that all
- * future calls to clk_enable() are practically NOPs with respect to
- * hardware and software states.
- *
- * See also: Comment for clk_set_parent() below.
- */
- /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
- if (core->flags & CLK_OPS_PARENT_ENABLE) {
- clk_core_prepare_enable(old_parent);
- clk_core_prepare_enable(parent);
- }
- /* migrate prepare count if > 0 */
- if (core->prepare_count) {
- clk_core_prepare_enable(parent);
- clk_core_enable_lock(core);
- }
- /* update the clk tree topology */
- flags = clk_enable_lock();
- clk_reparent(core, parent);
- clk_enable_unlock(flags);
- return old_parent;
- }
- static void __clk_set_parent_after(struct clk_core *core,
- struct clk_core *parent,
- struct clk_core *old_parent)
- {
- /*
- * Finish the migration of prepare state and undo the changes done
- * for preventing a race with clk_enable().
- */
- if (core->prepare_count) {
- clk_core_disable_lock(core);
- clk_core_disable_unprepare(old_parent);
- }
- /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
- if (core->flags & CLK_OPS_PARENT_ENABLE) {
- clk_core_disable_unprepare(parent);
- clk_core_disable_unprepare(old_parent);
- }
- }
- static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
- u8 p_index)
- {
- unsigned long flags;
- int ret = 0;
- struct clk_core *old_parent;
- old_parent = __clk_set_parent_before(core, parent);
- trace_clk_set_parent(core, parent);
- /* change clock input source */
- if (parent && core->ops->set_parent)
- ret = core->ops->set_parent(core->hw, p_index);
- trace_clk_set_parent_complete(core, parent);
- if (ret) {
- flags = clk_enable_lock();
- clk_reparent(core, old_parent);
- clk_enable_unlock(flags);
- __clk_set_parent_after(core, old_parent, parent);
- return ret;
- }
- __clk_set_parent_after(core, parent, old_parent);
- return 0;
- }
- /**
- * __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)
- {
- struct clk_core *child;
- unsigned long new_rate;
- int ret = NOTIFY_DONE;
- lockdep_assert_held(&prepare_lock);
- new_rate = clk_recalc(core, parent_rate);
- /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
- if (core->notifier_count)
- ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
- if (ret & NOTIFY_STOP_MASK) {
- pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
- __func__, core->name, ret);
- goto out;
- }
- hlist_for_each_entry(child, &core->children, child_node) {
- ret = __clk_speculate_rates(child, new_rate);
- if (ret & NOTIFY_STOP_MASK)
- break;
- }
- out:
- return ret;
- }
- static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
- struct clk_core *new_parent, u8 p_index)
- {
- struct clk_core *child;
- core->new_rate = new_rate;
- core->new_parent = new_parent;
- core->new_parent_index = p_index;
- /* include clk in new parent's PRE_RATE_CHANGE notifications */
- core->new_child = NULL;
- if (new_parent && new_parent != core->parent)
- new_parent->new_child = core;
- hlist_for_each_entry(child, &core->children, child_node) {
- child->new_rate = clk_recalc(child, new_rate);
- clk_calc_subtree(child, child->new_rate, NULL, 0);
- }
- }
- /*
- * 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)
- {
- struct clk_core *top = core;
- struct clk_core *old_parent, *parent;
- unsigned long best_parent_rate = 0;
- unsigned long new_rate;
- unsigned long min_rate;
- unsigned long max_rate;
- int p_index = 0;
- long ret;
- /* sanity */
- if (IS_ERR_OR_NULL(core))
- return NULL;
- /* save parent rate, if it exists */
- parent = old_parent = core->parent;
- if (parent)
- best_parent_rate = parent->rate;
- clk_core_get_boundaries(core, &min_rate, &max_rate);
- /* find the closest rate and parent clk/rate */
- if (clk_core_can_round(core)) {
- struct clk_rate_request req;
- clk_core_init_rate_req(core, &req, rate);
- ret = clk_core_determine_round_nolock(core, &req);
- if (ret < 0)
- return NULL;
- best_parent_rate = req.best_parent_rate;
- new_rate = req.rate;
- parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
- if (new_rate < min_rate || new_rate > max_rate)
- return NULL;
- } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
- /* pass-through clock without adjustable parent */
- core->new_rate = core->rate;
- return NULL;
- } else {
- /* pass-through clock with adjustable parent */
- top = clk_calc_new_rates(parent, rate);
- new_rate = parent->new_rate;
- goto out;
- }
- /* some clocks must be gated to change parent */
- if (parent != old_parent &&
- (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
- pr_debug("%s: %s not gated but wants to reparent\n",
- __func__, core->name);
- return NULL;
- }
- /* try finding the new parent index */
- if (parent && core->num_parents > 1) {
- p_index = clk_fetch_parent_index(core, parent);
- if (p_index < 0) {
- pr_debug("%s: clk %s can not be parent of clk %s\n",
- __func__, parent->name, core->name);
- return NULL;
- }
- }
- if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
- best_parent_rate != parent->rate)
- top = clk_calc_new_rates(parent, best_parent_rate);
- out:
- clk_calc_subtree(core, new_rate, parent, p_index);
- return top;
- }
- /*
- * 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)
- {
- struct clk_core *child, *tmp_clk, *fail_clk = NULL;
- int ret = NOTIFY_DONE;
- if (core->rate == core->new_rate)
- return NULL;
- if (core->notifier_count) {
- ret = __clk_notify(core, event, core->rate, core->new_rate);
- if (ret & NOTIFY_STOP_MASK)
- fail_clk = core;
- }
- if (core->ops->pre_rate_change) {
- ret = core->ops->pre_rate_change(core->hw, core->rate,
- core->new_rate);
- if (ret)
- fail_clk = core;
- }
- hlist_for_each_entry(child, &core->children, child_node) {
- /* Skip children who will be reparented to another clock */
- if (child->new_parent && child->new_parent != core)
- continue;
- tmp_clk = clk_propagate_rate_change(child, event);
- if (tmp_clk)
- fail_clk = tmp_clk;
- }
- /* handle the new child who might not be in core->children yet */
- if (core->new_child) {
- tmp_clk = clk_propagate_rate_change(core->new_child, event);
- if (tmp_clk)
- fail_clk = tmp_clk;
- }
- return fail_clk;
- }
- /*
- * 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)
- {
- struct clk_core *child;
- struct hlist_node *tmp;
- unsigned long old_rate;
- unsigned long best_parent_rate = 0;
- bool skip_set_rate = false;
- struct clk_core *old_parent;
- struct clk_core *parent = NULL;
- old_rate = core->rate;
- if (core->new_parent) {
- parent = core->new_parent;
- best_parent_rate = core->new_parent->rate;
- } else if (core->parent) {
- parent = core->parent;
- best_parent_rate = core->parent->rate;
- }
- if (clk_pm_runtime_get(core))
- return;
- if (core->flags & CLK_SET_RATE_UNGATE) {
- clk_core_prepare(core);
- clk_core_enable_lock(core);
- }
- if (core->new_parent && core->new_parent != core->parent) {
- old_parent = __clk_set_parent_before(core, core->new_parent);
- trace_clk_set_parent(core, core->new_parent);
- if (core->ops->set_rate_and_parent) {
- skip_set_rate = true;
- core->ops->set_rate_and_parent(core->hw, core->new_rate,
- best_parent_rate,
- core->new_parent_index);
- } else if (core->ops->set_parent) {
- core->ops->set_parent(core->hw, core->new_parent_index);
- }
- trace_clk_set_parent_complete(core, core->new_parent);
- __clk_set_parent_after(core, core->new_parent, old_parent);
- }
- if (core->flags & CLK_OPS_PARENT_ENABLE)
- clk_core_prepare_enable(parent);
- trace_clk_set_rate(core, core->new_rate);
- if (!skip_set_rate && core->ops->set_rate)
- core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
- trace_clk_set_rate_complete(core, core->new_rate);
- core->rate = clk_recalc(core, best_parent_rate);
- if (core->flags & CLK_SET_RATE_UNGATE) {
- clk_core_disable_lock(core);
- clk_core_unprepare(core);
- }
- if (core->flags & CLK_OPS_PARENT_ENABLE)
- clk_core_disable_unprepare(parent);
- if (core->notifier_count && old_rate != core->rate)
- __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
- if (core->flags & CLK_RECALC_NEW_RATES)
- (void)clk_calc_new_rates(core, core->new_rate);
- if (core->ops->post_rate_change)
- core->ops->post_rate_change(core->hw, old_rate, core->rate);
- /*
- * Use safe iteration, as change_rate can actually swap parents
- * for certain clock types.
- */
- hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
- /* Skip children who will be reparented to another clock */
- if (child->new_parent && child->new_parent != core)
- continue;
- clk_change_rate(child);
- }
- /* handle the new child who might not be in core->children yet */
- if (core->new_child)
- clk_change_rate(core->new_child);
- clk_pm_runtime_put(core);
- }
- static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
- unsigned long req_rate)
- {
- int ret, cnt;
- struct clk_rate_request req;
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return 0;
- /* simulate what the rate would be if it could be freely set */
- cnt = clk_core_rate_nuke_protect(core);
- if (cnt < 0)
- return cnt;
- clk_core_init_rate_req(core, &req, req_rate);
- ret = clk_core_round_rate_nolock(core, &req);
- /* restore the protection */
- clk_core_rate_restore_protect(core, cnt);
- return ret ? 0 : req.rate;
- }
- static int clk_core_set_rate_nolock(struct clk_core *core,
- unsigned long req_rate)
- {
- struct clk_core *top, *fail_clk;
- unsigned long rate;
- int ret;
- if (!core)
- return 0;
- rate = clk_core_req_round_rate_nolock(core, req_rate);
- /* bail early if nothing to do */
- if (rate == clk_core_get_rate_nolock(core))
- return 0;
- /* fail on a direct rate set of a protected provider */
- if (clk_core_rate_is_protected(core))
- return -EBUSY;
- /* calculate new rates and get the topmost changed clock */
- top = clk_calc_new_rates(core, req_rate);
- if (!top)
- return -EINVAL;
- ret = clk_pm_runtime_get(core);
- if (ret)
- return ret;
- /* notify that we are about to change rates */
- fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
- if (fail_clk) {
- pr_debug("%s: failed to set %s rate\n", __func__,
- fail_clk->name);
- clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
- ret = -EBUSY;
- goto err;
- }
- /* change the rates */
- clk_change_rate(top);
- core->req_rate = req_rate;
- err:
- clk_pm_runtime_put(core);
- return ret;
- }
- /**
- * 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)
- {
- int ret;
- if (!clk)
- return 0;
- /* prevent racing with updates to the clock topology */
- clk_prepare_lock();
- if (clk->exclusive_count)
- clk_core_rate_unprotect(clk->core);
- ret = clk_core_set_rate_nolock(clk->core, rate);
- if (clk->exclusive_count)
- clk_core_rate_protect(clk->core);
- clk_prepare_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(clk_set_rate);
- /**
- * 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)
- {
- int ret;
- if (!clk)
- return 0;
- /* prevent racing with updates to the clock topology */
- clk_prepare_lock();
- /*
- * The temporary protection removal is not here, on purpose
- * This function is meant to be used instead of clk_rate_protect,
- * so before the consumer code path protect the clock provider
- */
- ret = clk_core_set_rate_nolock(clk->core, rate);
- if (!ret) {
- clk_core_rate_protect(clk->core);
- clk->exclusive_count++;
- }
- clk_prepare_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
- static int clk_set_rate_range_nolock(struct clk *clk,
- unsigned long min,
- unsigned long max)
- {
- int ret = 0;
- unsigned long old_min, old_max, rate;
- lockdep_assert_held(&prepare_lock);
- if (!clk)
- return 0;
- trace_clk_set_rate_range(clk->core, min, max);
- if (min > max) {
- pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
- __func__, clk->core->name, clk->dev_id, clk->con_id,
- min, max);
- return -EINVAL;
- }
- if (clk->exclusive_count)
- clk_core_rate_unprotect(clk->core);
- /* Save the current values in case we need to rollback the change */
- old_min = clk->min_rate;
- old_max = clk->max_rate;
- clk->min_rate = min;
- clk->max_rate = max;
- if (!clk_core_check_boundaries(clk->core, min, max)) {
- ret = -EINVAL;
- goto out;
- }
- rate = clk->core->req_rate;
- if (clk->core->flags & CLK_GET_RATE_NOCACHE)
- rate = clk_core_get_rate_recalc(clk->core);
- /*
- * Since the boundaries have been changed, let's give the
- * opportunity to the provider to adjust the clock rate based on
- * the new boundaries.
- *
- * We also need to handle the case where the clock is currently
- * outside of the boundaries. Clamping the last requested rate
- * to the current minimum and maximum will also handle this.
- *
- * FIXME:
- * There is a catch. It may fail for the usual reason (clock
- * broken, clock protected, etc) but also because:
- * - round_rate() was not favorable and fell on the wrong
- * side of the boundary
- * - the determine_rate() callback does not really check for
- * this corner case when determining the rate
- */
- rate = clamp(rate, min, max);
- ret = clk_core_set_rate_nolock(clk->core, rate);
- if (ret) {
- /* rollback the changes */
- clk->min_rate = old_min;
- clk->max_rate = old_max;
- }
- out:
- if (clk->exclusive_count)
- clk_core_rate_protect(clk->core);
- return ret;
- }
- /**
- * 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)
- {
- int ret;
- if (!clk)
- return 0;
- clk_prepare_lock();
- ret = clk_set_rate_range_nolock(clk, min, max);
- clk_prepare_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(clk_set_rate_range);
- /**
- * 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)
- {
- if (!clk)
- return 0;
- trace_clk_set_min_rate(clk->core, rate);
- return clk_set_rate_range(clk, rate, clk->max_rate);
- }
- EXPORT_SYMBOL_GPL(clk_set_min_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)
- {
- if (!clk)
- return 0;
- trace_clk_set_max_rate(clk->core, rate);
- return clk_set_rate_range(clk, clk->min_rate, rate);
- }
- EXPORT_SYMBOL_GPL(clk_set_max_rate);
- /**
- * 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)
- {
- struct clk *parent;
- if (!clk)
- return NULL;
- clk_prepare_lock();
- /* TODO: Create a per-user clk and change callers to call clk_put */
- parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
- clk_prepare_unlock();
- return parent;
- }
- EXPORT_SYMBOL_GPL(clk_get_parent);
- static struct clk_core *__clk_init_parent(struct clk_core *core)
- {
- u8 index = 0;
- if (core->num_parents > 1 && core->ops->get_parent)
- index = core->ops->get_parent(core->hw);
- return clk_core_get_parent_by_index(core, index);
- }
- static void clk_core_reparent(struct clk_core *core,
- struct clk_core *new_parent)
- {
- clk_reparent(core, new_parent);
- __clk_recalc_accuracies(core);
- __clk_recalc_rates(core, true, POST_RATE_CHANGE);
- }
- void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
- {
- if (!hw)
- return;
- clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
- }
- /**
- * 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)
- {
- /* NULL clocks should be nops, so return success if either is NULL. */
- if (!clk || !parent)
- return true;
- return clk_core_has_parent(clk->core, parent->core);
- }
- EXPORT_SYMBOL_GPL(clk_has_parent);
- static int clk_core_set_parent_nolock(struct clk_core *core,
- struct clk_core *parent)
- {
- int ret = 0;
- int p_index = 0;
- unsigned long p_rate = 0;
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return 0;
- if (core->parent == parent)
- return 0;
- /* verify ops for multi-parent clks */
- if (core->num_parents > 1 && !core->ops->set_parent)
- return -EPERM;
- /* check that we are allowed to re-parent if the clock is in use */
- if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
- return -EBUSY;
- if (clk_core_rate_is_protected(core))
- return -EBUSY;
- /* try finding the new parent index */
- if (parent) {
- p_index = clk_fetch_parent_index(core, parent);
- if (p_index < 0) {
- pr_debug("%s: clk %s can not be parent of clk %s\n",
- __func__, parent->name, core->name);
- return p_index;
- }
- p_rate = parent->rate;
- }
- ret = clk_pm_runtime_get(core);
- if (ret)
- return ret;
- /* propagate PRE_RATE_CHANGE notifications */
- ret = __clk_speculate_rates(core, p_rate);
- /* abort if a driver objects */
- if (ret & NOTIFY_STOP_MASK)
- goto runtime_put;
- /* do the re-parent */
- ret = __clk_set_parent(core, parent, p_index);
- /* propagate rate an accuracy recalculation accordingly */
- if (ret) {
- __clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
- } else {
- __clk_recalc_rates(core, true, POST_RATE_CHANGE);
- __clk_recalc_accuracies(core);
- }
- runtime_put:
- clk_pm_runtime_put(core);
- return ret;
- }
- int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
- {
- return clk_core_set_parent_nolock(hw->core, parent->core);
- }
- EXPORT_SYMBOL_GPL(clk_hw_set_parent);
- /**
- * 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)
- {
- int ret;
- if (!clk)
- return 0;
- clk_prepare_lock();
- if (clk->exclusive_count)
- clk_core_rate_unprotect(clk->core);
- ret = clk_core_set_parent_nolock(clk->core,
- parent ? parent->core : NULL);
- if (clk->exclusive_count)
- clk_core_rate_protect(clk->core);
- clk_prepare_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(clk_set_parent);
- static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
- {
- int ret = -EINVAL;
- lockdep_assert_held(&prepare_lock);
- if (!core)
- return 0;
- if (clk_core_rate_is_protected(core))
- return -EBUSY;
- trace_clk_set_phase(core, degrees);
- if (core->ops->set_phase) {
- ret = core->ops->set_phase(core->hw, degrees);
- if (!ret)
- core->phase = degrees;
- }
- trace_clk_set_phase_complete(core, degrees);
- return ret;
- }
- /**
- * 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)
- {
- int ret;
- if (!clk)
- return 0;
- /* sanity check degrees */
- degrees %= 360;
- if (degrees < 0)
- degrees += 360;
- clk_prepare_lock();
- if (clk->exclusive_count)
- clk_core_rate_unprotect(clk->core);
- ret = clk_core_set_phase_nolock(clk->core, degrees);
- if (clk->exclusive_count)
- clk_core_rate_protect(clk->core);
- clk_prepare_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(clk_set_phase);
- static int clk_core_get_phase(struct clk_core *core)
- {
- int ret;
- lockdep_assert_held(&prepare_lock);
- if (!core->ops->get_phase)
- return 0;
- /* Always try to update cached phase if possible */
- ret = core->ops->get_phase(core->hw);
- if (ret >= 0)
- core->phase = ret;
- return ret;
- }
- /**
- * 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)
- {
- int ret;
- if (!clk)
- return 0;
- clk_prepare_lock();
- ret = clk_core_get_phase(clk->core);
- clk_prepare_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(clk_get_phase);
- static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
- {
- /* Assume a default value of 50% */
- core->duty.num = 1;
- core->duty.den = 2;
- }
- 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)
- {
- struct clk_duty *duty = &core->duty;
- int ret = 0;
- if (!core->ops->get_duty_cycle)
- return clk_core_update_duty_cycle_parent_nolock(core);
- ret = core->ops->get_duty_cycle(core->hw, duty);
- if (ret)
- goto reset;
- /* Don't trust the clock provider too much */
- if (duty->den == 0 || duty->num > duty->den) {
- ret = -EINVAL;
- goto reset;
- }
- return 0;
- reset:
- clk_core_reset_duty_cycle_nolock(core);
- return ret;
- }
- static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
- {
- int ret = 0;
- if (core->parent &&
- core->flags & CLK_DUTY_CYCLE_PARENT) {
- ret = clk_core_update_duty_cycle_nolock(core->parent);
- memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
- } else {
- clk_core_reset_duty_cycle_nolock(core);
- }
- return ret;
- }
- 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)
- {
- int ret;
- lockdep_assert_held(&prepare_lock);
- if (clk_core_rate_is_protected(core))
- return -EBUSY;
- trace_clk_set_duty_cycle(core, duty);
- if (!core->ops->set_duty_cycle)
- return clk_core_set_duty_cycle_parent_nolock(core, duty);
- ret = core->ops->set_duty_cycle(core->hw, duty);
- if (!ret)
- memcpy(&core->duty, duty, sizeof(*duty));
- trace_clk_set_duty_cycle_complete(core, duty);
- return ret;
- }
- static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
- struct clk_duty *duty)
- {
- int ret = 0;
- if (core->parent &&
- core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
- ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
- memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
- }
- return ret;
- }
- /**
- * 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)
- {
- int ret;
- struct clk_duty duty;
- if (!clk)
- return 0;
- /* sanity check the ratio */
- if (den == 0 || num > den)
- return -EINVAL;
- duty.num = num;
- duty.den = den;
- clk_prepare_lock();
- if (clk->exclusive_count)
- clk_core_rate_unprotect(clk->core);
- ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
- if (clk->exclusive_count)
- clk_core_rate_protect(clk->core);
- clk_prepare_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
- static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
- unsigned int scale)
- {
- struct clk_duty *duty = &core->duty;
- int ret;
- clk_prepare_lock();
- ret = clk_core_update_duty_cycle_nolock(core);
- if (!ret)
- ret = mult_frac(scale, duty->num, duty->den);
- clk_prepare_unlock();
- return ret;
- }
- /**
- * 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)
- {
- if (!clk)
- return 0;
- return clk_core_get_scaled_duty_cycle(clk->core, scale);
- }
- EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
- /**
- * 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)
- {
- /* trivial case: identical struct clk's or both NULL */
- if (p == q)
- return true;
- /* true if clk->core pointers match. Avoid dereferencing garbage */
- if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
- if (p->core == q->core)
- return true;
- return false;
- }
- EXPORT_SYMBOL_GPL(clk_is_match);
- /*** debugfs support ***/
- #ifdef CONFIG_DEBUG_FS
- #include <linux/debugfs.h>
- static struct dentry *rootdir;
- static int inited = 0;
- static DEFINE_MUTEX(clk_debug_lock);
- static HLIST_HEAD(clk_debug_list);
- static struct hlist_head *orphan_list[] = {
- &clk_orphan_list,
- NULL,
- };
- static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
- int level)
- {
- int phase;
- seq_printf(s, "%*s%-*s %7d %8d %8d %11lu %10lu ",
- level * 3 + 1, "",
- 30 - level * 3, c->name,
- c->enable_count, c->prepare_count, c->protect_count,
- clk_core_get_rate_recalc(c),
- clk_core_get_accuracy_recalc(c));
- phase = clk_core_get_phase(c);
- if (phase >= 0)
- seq_printf(s, "%5d", phase);
- else
- seq_puts(s, "-----");
- seq_printf(s, " %6d", clk_core_get_scaled_duty_cycle(c, 100000));
- if (c->ops->is_enabled)
- seq_printf(s, " %9c\n", clk_core_is_enabled(c) ? 'Y' : 'N');
- else if (!c->ops->enable)
- seq_printf(s, " %9c\n", 'Y');
- else
- seq_printf(s, " %9c\n", '?');
- }
- static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
- int level)
- {
- struct clk_core *child;
- clk_pm_runtime_get(c);
- clk_summary_show_one(s, c, level);
- clk_pm_runtime_put(c);
- hlist_for_each_entry(child, &c->children, child_node)
- clk_summary_show_subtree(s, child, level + 1);
- }
- static int clk_summary_show(struct seq_file *s, void *data)
- {
- struct clk_core *c;
- struct hlist_head **lists = (struct hlist_head **)s->private;
- seq_puts(s, " enable prepare protect duty hardware\n");
- seq_puts(s, " clock count count count rate accuracy phase cycle enable\n");
- seq_puts(s, "-------------------------------------------------------------------------------------------------------\n");
- clk_prepare_lock();
- for (; *lists; lists++)
- hlist_for_each_entry(c, *lists, child_node)
- clk_summary_show_subtree(s, c, 0);
- clk_prepare_unlock();
- return 0;
- }
- DEFINE_SHOW_ATTRIBUTE(clk_summary);
- static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
- {
- int phase;
- unsigned long min_rate, max_rate;
- clk_core_get_boundaries(c, &min_rate, &max_rate);
- /* This should be JSON format, i.e. elements separated with a comma */
- seq_printf(s, "\"%s\": { ", c->name);
- seq_printf(s, "\"enable_count\": %d,", c->enable_count);
- seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
- seq_printf(s, "\"protect_count\": %d,", c->protect_count);
- seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
- seq_printf(s, "\"min_rate\": %lu,", min_rate);
- seq_printf(s, "\"max_rate\": %lu,", max_rate);
- seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
- phase = clk_core_get_phase(c);
- if (phase >= 0)
- seq_printf(s, "\"phase\": %d,", phase);
- seq_printf(s, "\"duty_cycle\": %u",
- clk_core_get_scaled_duty_cycle(c, 100000));
- }
- static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
- {
- struct clk_core *child;
- clk_dump_one(s, c, level);
- hlist_for_each_entry(child, &c->children, child_node) {
- seq_putc(s, ',');
- clk_dump_subtree(s, child, level + 1);
- }
- seq_putc(s, '}');
- }
- static int clk_dump_show(struct seq_file *s, void *data)
- {
- struct clk_core *c;
- bool first_node = true;
- struct hlist_head **lists = (struct hlist_head **)s->private;
- seq_putc(s, '{');
- clk_prepare_lock();
- for (; *lists; lists++) {
- hlist_for_each_entry(c, *lists, child_node) {
- if (!first_node)
- seq_putc(s, ',');
- first_node = false;
- clk_dump_subtree(s, c, 0);
- }
- }
- clk_prepare_unlock();
- seq_puts(s, "}\n");
- return 0;
- }
- DEFINE_SHOW_ATTRIBUTE(clk_dump);
- #define 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 0644
- 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 NULL
- #define clk_rate_mode 0444
- #endif
- static int clk_rate_get(void *data, u64 *val)
- {
- struct clk_core *core = data;
- clk_prepare_lock();
- *val = clk_core_get_rate_recalc(core);
- clk_prepare_unlock();
- return 0;
- }
- DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
- static const struct {
- unsigned long flag;
- const char *name;
- } clk_flags[] = {
- #define ENTRY(f) { f, #f }
- ENTRY(CLK_SET_RATE_GATE),
- ENTRY(CLK_SET_PARENT_GATE),
- ENTRY(CLK_SET_RATE_PARENT),
- ENTRY(CLK_IGNORE_UNUSED),
- ENTRY(CLK_GET_RATE_NOCACHE),
- ENTRY(CLK_SET_RATE_NO_REPARENT),
- ENTRY(CLK_GET_ACCURACY_NOCACHE),
- ENTRY(CLK_RECALC_NEW_RATES),
- ENTRY(CLK_SET_RATE_UNGATE),
- ENTRY(CLK_IS_CRITICAL),
- ENTRY(CLK_OPS_PARENT_ENABLE),
- ENTRY(CLK_DUTY_CYCLE_PARENT),
- #undef ENTRY
- };
- static int clk_flags_show(struct seq_file *s, void *data)
- {
- struct clk_core *core = s->private;
- unsigned long flags = core->flags;
- unsigned int i;
- for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
- if (flags & clk_flags[i].flag) {
- seq_printf(s, "%s\n", clk_flags[i].name);
- flags &= ~clk_flags[i].flag;
- }
- }
- if (flags) {
- /* Unknown flags */
- seq_printf(s, "0x%lx\n", flags);
- }
- return 0;
- }
- DEFINE_SHOW_ATTRIBUTE(clk_flags);
- static void possible_parent_show(struct seq_file *s, struct clk_core *core,
- unsigned int i, char terminator)
- {
- struct clk_core *parent;
- const char *name = NULL;
- /*
- * Go through the following options to fetch a parent's name.
- *
- * 1. Fetch the registered parent clock and use its name
- * 2. Use the global (fallback) name if specified
- * 3. Use the local fw_name if provided
- * 4. Fetch parent clock's clock-output-name if DT index was set
- *
- * This may still fail in some cases, such as when the parent is
- * specified directly via a struct clk_hw pointer, but it isn't
- * registered (yet).
- */
- parent = clk_core_get_parent_by_index(core, i);
- if (parent) {
- seq_puts(s, parent->name);
- } else if (core->parents[i].name) {
- seq_puts(s, core->parents[i].name);
- } else if (core->parents[i].fw_name) {
- seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
- } else {
- if (core->parents[i].index >= 0)
- name = of_clk_get_parent_name(core->of_node, core->parents[i].index);
- if (!name)
- name = "(missing)";
- seq_puts(s, name);
- }
- seq_putc(s, terminator);
- }
- static int possible_parents_show(struct seq_file *s, void *data)
- {
- struct clk_core *core = s->private;
- int i;
- for (i = 0; i < core->num_parents - 1; i++)
- possible_parent_show(s, core, i, ' ');
- possible_parent_show(s, core, i, '\n');
- return 0;
- }
- DEFINE_SHOW_ATTRIBUTE(possible_parents);
- static int current_parent_show(struct seq_file *s, void *data)
- {
- struct clk_core *core = s->private;
- if (core->parent)
- seq_printf(s, "%s\n", core->parent->name);
- return 0;
- }
- DEFINE_SHOW_ATTRIBUTE(current_parent);
- #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)
- {
- struct clk_core *core = s->private;
- struct clk_duty *duty = &core->duty;
- seq_printf(s, "%u/%u\n", duty->num, duty->den);
- return 0;
- }
- DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
- static int clk_min_rate_show(struct seq_file *s, void *data)
- {
- struct clk_core *core = s->private;
- unsigned long min_rate, max_rate;
- clk_prepare_lock();
- clk_core_get_boundaries(core, &min_rate, &max_rate);
- clk_prepare_unlock();
- seq_printf(s, "%lu\n", min_rate);
- return 0;
- }
- DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
- static int clk_max_rate_show(struct seq_file *s, void *data)
- {
- struct clk_core *core = s->private;
- unsigned long min_rate, max_rate;
- clk_prepare_lock();
- clk_core_get_boundaries(core, &min_rate, &max_rate);
- clk_prepare_unlock();
- seq_printf(s, "%lu\n", max_rate);
- return 0;
- }
- DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
- static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
- {
- struct dentry *root;
- if (!core || !pdentry)
- return;
- root = debugfs_create_dir(core->name, pdentry);
- core->dentry = root;
- debugfs_create_file("clk_rate", clk_rate_mode, root, core,
- &clk_rate_fops);
- debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
- debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
- debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
- debugfs_create_u32("clk_phase", 0444, root, &core->phase);
- debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
- debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
- debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
- debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
- debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
- debugfs_create_file("clk_duty_cycle", 0444, root, core,
- &clk_duty_cycle_fops);
- #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
- debugfs_create_file("clk_prepare_enable", 0644, root, core,
- &clk_prepare_enable_fops);
- if (core->num_parents > 1)
- debugfs_create_file("clk_parent", 0644, root, core,
- ¤t_parent_rw_fops);
- else
- #endif
- if (core->num_parents > 0)
- debugfs_create_file("clk_parent", 0444, root, core,
- ¤t_parent_fops);
- if (core->num_parents > 1)
- debugfs_create_file("clk_possible_parents", 0444, root, core,
- &possible_parents_fops);
- if (core->ops->debug_init)
- core->ops->debug_init(core->hw, core->dentry);
- }
- /**
- * 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)
- {
- mutex_lock(&clk_debug_lock);
- hlist_add_head(&core->debug_node, &clk_debug_list);
- if (inited)
- clk_debug_create_one(core, rootdir);
- mutex_unlock(&clk_debug_lock);
- }
- /**
- * 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)
- {
- mutex_lock(&clk_debug_lock);
- hlist_del_init(&core->debug_node);
- debugfs_remove_recursive(core->dentry);
- core->dentry = NULL;
- mutex_unlock(&clk_debug_lock);
- }
- /**
- * 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)
- {
- struct clk_core *core;
- rootdir = debugfs_create_dir("clk", NULL);
- debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
- &clk_summary_fops);
- debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
- &clk_dump_fops);
- debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
- &clk_summary_fops);
- debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
- &clk_dump_fops);
- mutex_lock(&clk_debug_lock);
- hlist_for_each_entry(core, &clk_debug_list, debug_node)
- clk_debug_create_one(core, rootdir);
- inited = 1;
- mutex_unlock(&clk_debug_lock);
- return 0;
- }
- 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)
- {
- struct clk_core *orphan;
- struct hlist_node *tmp2;
- /*
- * walk the list of orphan clocks and reparent any that newly finds a
- * parent.
- */
- hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
- struct clk_core *parent = __clk_init_parent(orphan);
- /*
- * We need to use __clk_set_parent_before() and _after() to
- * properly migrate any prepare/enable count of the orphan
- * clock. This is important for CLK_IS_CRITICAL clocks, which
- * are enabled during init but might not have a parent yet.
- */
- if (parent) {
- /* update the clk tree topology */
- __clk_set_parent_before(orphan, parent);
- __clk_set_parent_after(orphan, parent, NULL);
- __clk_recalc_accuracies(orphan);
- __clk_recalc_rates(orphan, true, 0);
- __clk_core_update_orphan_hold_state(orphan);
- /*
- * __clk_init_parent() will set the initial req_rate to
- * 0 if the clock doesn't have clk_ops::recalc_rate and
- * is an orphan when it's registered.
- *
- * 'req_rate' is used by clk_set_rate_range() and
- * clk_put() to trigger a clk_set_rate() call whenever
- * the boundaries are modified. Let's make sure
- * 'req_rate' is set to something non-zero so that
- * clk_set_rate_range() doesn't drop the frequency.
- */
- orphan->req_rate = orphan->rate;
- }
- }
- }
- /**
- * __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)
- {
- int ret;
- struct clk_core *parent;
- unsigned long rate;
- int phase;
- clk_prepare_lock();
- /*
- * Set hw->core after grabbing the prepare_lock to synchronize with
- * callers of clk_core_fill_parent_index() where we treat hw->core
- * being NULL as the clk not being registered yet. This is crucial so
- * that clks aren't parented until their parent is fully registered.
- */
- core->hw->core = core;
- ret = clk_pm_runtime_get(core);
- if (ret)
- goto unlock;
- /* check to see if a clock with this name is already registered */
- if (clk_core_lookup(core->name)) {
- pr_debug("%s: clk %s already initialized\n",
- __func__, core->name);
- ret = -EEXIST;
- goto out;
- }
- /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
- if (core->ops->set_rate &&
- !((core->ops->round_rate || core->ops->determine_rate) &&
- core->ops->recalc_rate)) {
- pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
- __func__, core->name);
- ret = -EINVAL;
- goto out;
- }
- if (core->ops->set_parent && !core->ops->get_parent) {
- pr_err("%s: %s must implement .get_parent & .set_parent\n",
- __func__, core->name);
- ret = -EINVAL;
- goto out;
- }
- if (core->num_parents > 1 && !core->ops->get_parent) {
- pr_err("%s: %s must implement .get_parent as it has multi parents\n",
- __func__, core->name);
- ret = -EINVAL;
- goto out;
- }
- if (core->ops->set_rate_and_parent &&
- !(core->ops->set_parent && core->ops->set_rate)) {
- pr_err("%s: %s must implement .set_parent & .set_rate\n",
- __func__, core->name);
- ret = -EINVAL;
- goto out;
- }
- /*
- * optional platform-specific magic
- *
- * The .init callback is not used by any of the basic clock types, but
- * exists for weird hardware that must perform initialization magic for
- * CCF to get an accurate view of clock for any other callbacks. It may
- * also be used needs to perform dynamic allocations. Such allocation
- * must be freed in the terminate() callback.
- * This callback shall not be used to initialize the parameters state,
- * such as rate, parent, etc ...
- *
- * If it exist, this callback should called before any other callback of
- * the clock
- */
- if (core->ops->init) {
- ret = core->ops->init(core->hw);
- if (ret)
- goto out;
- }
- parent = core->parent = __clk_init_parent(core);
- /*
- * Populate core->parent if parent has already been clk_core_init'd. If
- * parent has not yet been clk_core_init'd then place clk in the orphan
- * list. If clk doesn't have any parents then place it in the root
- * clk list.
- *
- * Every time a new clk is clk_init'd then we walk the list of orphan
- * clocks and re-parent any that are children of the clock currently
- * being clk_init'd.
- */
- if (parent) {
- hlist_add_head(&core->child_node, &parent->children);
- core->orphan = parent->orphan;
- } else if (!core->num_parents) {
- hlist_add_head(&core->child_node, &clk_root_list);
- core->orphan = false;
- } else {
- hlist_add_head(&core->child_node, &clk_orphan_list);
- core->orphan = true;
- }
- /*
- * Set clk's accuracy. The preferred method is to use
- * .recalc_accuracy. For simple clocks and lazy developers the default
- * fallback is to use the parent's accuracy. If a clock doesn't have a
- * parent (or is orphaned) then accuracy is set to zero (perfect
- * clock).
- */
- if (core->ops->recalc_accuracy)
- core->accuracy = core->ops->recalc_accuracy(core->hw,
- clk_core_get_accuracy_no_lock(parent));
- else if (parent)
- core->accuracy = parent->accuracy;
- else
- core->accuracy = 0;
- /*
- * Set clk's phase by clk_core_get_phase() caching the phase.
- * Since a phase is by definition relative to its parent, just
- * query the current clock phase, or just assume it's in phase.
- */
- phase = clk_core_get_phase(core);
- if (phase < 0) {
- ret = phase;
- pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
- core->name);
- goto out;
- }
- /*
- * Set clk's duty cycle.
- */
- clk_core_update_duty_cycle_nolock(core);
- /*
- * Set clk's rate. The preferred method is to use .recalc_rate. For
- * simple clocks and lazy developers the default fallback is to use the
- * parent's rate. If a clock doesn't have a parent (or is orphaned)
- * then rate is set to zero.
- */
- if (core->ops->recalc_rate)
- rate = core->ops->recalc_rate(core->hw,
- clk_core_get_rate_nolock(parent));
- else if (parent)
- rate = parent->rate;
- else
- rate = 0;
- core->rate = core->req_rate = rate;
- core->boot_enabled = clk_core_is_enabled(core);
- /*
- * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
- * don't get accidentally disabled when walking the orphan tree and
- * reparenting clocks
- */
- if (core->flags & CLK_IS_CRITICAL) {
- ret = clk_core_prepare(core);
- if (ret) {
- pr_warn("%s: critical clk '%s' failed to prepare\n",
- __func__, core->name);
- goto out;
- }
- ret = clk_core_enable_lock(core);
- if (ret) {
- pr_warn("%s: critical clk '%s' failed to enable\n",
- __func__, core->name);
- clk_core_unprepare(core);
- goto out;
- }
- }
- clk_core_hold_state(core);
- clk_core_reparent_orphans_nolock();
- kref_init(&core->ref);
- out:
- clk_pm_runtime_put(core);
- unlock:
- if (ret) {
- hlist_del_init(&core->child_node);
- core->hw->core = NULL;
- }
- clk_prepare_unlock();
- if (!ret)
- clk_debug_register(core);
- return ret;
- }
- /**
- * 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_prepare_lock();
- hlist_add_head(&clk->clks_node, &core->clks);
- clk_prepare_unlock();
- }
- /**
- * 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)
- {
- lockdep_assert_held(&prepare_lock);
- hlist_del(&clk->clks_node);
- }
- /**
- * 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)
- {
- struct clk *clk;
- clk = kzalloc(sizeof(*clk), GFP_KERNEL);
- if (!clk)
- return ERR_PTR(-ENOMEM);
- clk->core = core;
- clk->dev_id = dev_id;
- clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
- clk->max_rate = ULONG_MAX;
- return clk;
- }
- /**
- * 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)
- {
- kfree_const(clk->con_id);
- kfree(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)
- {
- struct clk *clk;
- struct clk_core *core;
- /* This is to allow this function to be chained to others */
- if (IS_ERR_OR_NULL(hw))
- return ERR_CAST(hw);
- core = hw->core;
- clk = alloc_clk(core, dev_id, con_id);
- if (IS_ERR(clk))
- return clk;
- clk->dev = dev;
- if (!try_module_get(core->owner)) {
- free_clk(clk);
- return ERR_PTR(-ENOENT);
- }
- kref_get(&core->ref);
- clk_core_link_consumer(core, clk);
- return clk;
- }
- /**
- * 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)
- {
- struct device *dev = hw->core->dev;
- const char *name = dev ? dev_name(dev) : NULL;
- return clk_hw_create_clk(dev, hw, name, con_id);
- }
- EXPORT_SYMBOL(clk_hw_get_clk);
- static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
- {
- const char *dst;
- if (!src) {
- if (must_exist)
- return -EINVAL;
- return 0;
- }
- *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
- if (!dst)
- return -ENOMEM;
- return 0;
- }
- static int clk_core_populate_parent_map(struct clk_core *core,
- const struct clk_init_data *init)
- {
- u8 num_parents = init->num_parents;
- const char * const *parent_names = init->parent_names;
- const struct clk_hw **parent_hws = init->parent_hws;
- const struct clk_parent_data *parent_data = init->parent_data;
- int i, ret = 0;
- struct clk_parent_map *parents, *parent;
- if (!num_parents)
- return 0;
- /*
- * Avoid unnecessary string look-ups of clk_core's possible parents by
- * having a cache of names/clk_hw pointers to clk_core pointers.
- */
- parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
- core->parents = parents;
- if (!parents)
- return -ENOMEM;
- /* Copy everything over because it might be __initdata */
- for (i = 0, parent = parents; i < num_parents; i++, parent++) {
- parent->index = -1;
- if (parent_names) {
- /* throw a WARN if any entries are NULL */
- WARN(!parent_names[i],
- "%s: invalid NULL in %s's .parent_names\n",
- __func__, core->name);
- ret = clk_cpy_name(&parent->name, parent_names[i],
- true);
- } else if (parent_data) {
- parent->hw = parent_data[i].hw;
- parent->index = parent_data[i].index;
- ret = clk_cpy_name(&parent->fw_name,
- parent_data[i].fw_name, false);
- if (!ret)
- ret = clk_cpy_name(&parent->name,
- parent_data[i].name,
- false);
- } else if (parent_hws) {
- parent->hw = parent_hws[i];
- } else {
- ret = -EINVAL;
- WARN(1, "Must specify parents if num_parents > 0\n");
- }
- if (ret) {
- do {
- kfree_const(parents[i].name);
- kfree_const(parents[i].fw_name);
- } while (--i >= 0);
- kfree(parents);
- return ret;
- }
- }
- return 0;
- }
- static void clk_core_free_parent_map(struct clk_core *core)
- {
- int i = core->num_parents;
- if (!core->num_parents)
- return;
- while (--i >= 0) {
- kfree_const(core->parents[i].name);
- kfree_const(core->parents[i].fw_name);
- }
- kfree(core->parents);
- }
- static struct clk *
- __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
- {
- int ret;
- struct clk_core *core;
- const struct clk_init_data *init = hw->init;
- /*
- * The init data is not supposed to be used outside of registration path.
- * Set it to NULL so that provider drivers can't use it either and so that
- * we catch use of hw->init early on in the core.
- */
- hw->init = NULL;
- core = kzalloc(sizeof(*core), GFP_KERNEL);
- if (!core) {
- ret = -ENOMEM;
- goto fail_out;
- }
- core->name = kstrdup_const(init->name, GFP_KERNEL);
- if (!core->name) {
- ret = -ENOMEM;
- goto fail_name;
- }
- if (WARN_ON(!init->ops)) {
- ret = -EINVAL;
- goto fail_ops;
- }
- core->ops = init->ops;
- if (dev && pm_runtime_enabled(dev))
- core->rpm_enabled = true;
- core->dev = dev;
- core->of_node = np;
- if (dev && dev->driver)
- core->owner = dev->driver->owner;
- core->hw = hw;
- core->flags = init->flags;
- core->num_parents = init->num_parents;
- core->min_rate = 0;
- core->max_rate = ULONG_MAX;
- ret = clk_core_populate_parent_map(core, init);
- if (ret)
- goto fail_parents;
- INIT_HLIST_HEAD(&core->clks);
- /*
- * Don't call clk_hw_create_clk() here because that would pin the
- * provider module to itself and prevent it from ever being removed.
- */
- hw->clk = alloc_clk(core, NULL, NULL);
- if (IS_ERR(hw->clk)) {
- ret = PTR_ERR(hw->clk);
- goto fail_create_clk;
- }
- clk_core_link_consumer(core, hw->clk);
- ret = __clk_core_init(core);
- if (!ret)
- return hw->clk;
- clk_prepare_lock();
- clk_core_unlink_consumer(hw->clk);
- clk_prepare_unlock();
- free_clk(hw->clk);
- hw->clk = NULL;
- fail_create_clk:
- clk_core_free_parent_map(core);
- fail_parents:
- fail_ops:
- kfree_const(core->name);
- fail_name:
- kfree(core);
- fail_out:
- return ERR_PTR(ret);
- }
- /**
- * 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)
- {
- struct device_node *np;
- if (!dev)
- return NULL;
- np = dev_of_node(dev);
- if (!np)
- np = dev_of_node(dev->parent);
- return np;
- }
- /**
- * 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)
- {
- return __clk_register(dev, dev_or_parent_of_node(dev), hw);
- }
- EXPORT_SYMBOL_GPL(clk_register);
- /**
- * 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)
- {
- return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
- hw));
- }
- EXPORT_SYMBOL_GPL(clk_hw_register);
- /*
- * 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)
- {
- return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
- }
- EXPORT_SYMBOL_GPL(of_clk_hw_register);
- /* Free memory allocated for a clock. */
- static void __clk_release(struct kref *ref)
- {
- struct clk_core *core = container_of(ref, struct clk_core, ref);
- lockdep_assert_held(&prepare_lock);
- clk_core_free_parent_map(core);
- kfree_const(core->name);
- kfree(core);
- }
- /*
- * 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)
- {
- return -ENXIO;
- }
- static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
- {
- WARN_ON_ONCE(1);
- }
- static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long parent_rate)
- {
- return -ENXIO;
- }
- static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
- {
- return -ENXIO;
- }
- static const struct clk_ops clk_nodrv_ops = {
- .enable = clk_nodrv_prepare_enable,
- .disable = clk_nodrv_disable_unprepare,
- .prepare = clk_nodrv_prepare_enable,
- .unprepare = clk_nodrv_disable_unprepare,
- .set_rate = clk_nodrv_set_rate,
- .set_parent = clk_nodrv_set_parent,
- };
- static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
- const struct clk_core *target)
- {
- int i;
- struct clk_core *child;
- for (i = 0; i < root->num_parents; i++)
- if (root->parents[i].core == target)
- root->parents[i].core = NULL;
- hlist_for_each_entry(child, &root->children, child_node)
- clk_core_evict_parent_cache_subtree(child, target);
- }
- /* Remove this clk from all parent caches */
- static void clk_core_evict_parent_cache(struct clk_core *core)
- {
- const struct hlist_head **lists;
- struct clk_core *root;
- lockdep_assert_held(&prepare_lock);
- for (lists = all_lists; *lists; lists++)
- hlist_for_each_entry(root, *lists, child_node)
- clk_core_evict_parent_cache_subtree(root, core);
- }
- /**
- * clk_unregister - unregister a currently registered clock
- * @clk: clock to unregister
- */
- void clk_unregister(struct clk *clk)
- {
- unsigned long flags;
- const struct clk_ops *ops;
- if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
- return;
- clk_debug_unregister(clk->core);
- clk_prepare_lock();
- ops = clk->core->ops;
- if (ops == &clk_nodrv_ops) {
- pr_err("%s: unregistered clock: %s\n", __func__,
- clk->core->name);
- goto unlock;
- }
- /*
- * Assign empty clock ops for consumers that might still hold
- * a reference to this clock.
- */
- flags = clk_enable_lock();
- clk->core->ops = &clk_nodrv_ops;
- clk_enable_unlock(flags);
- if (ops->terminate)
- ops->terminate(clk->core->hw);
- if (!hlist_empty(&clk->core->children)) {
- struct clk_core *child;
- struct hlist_node *t;
- /* Reparent all children to the orphan list. */
- hlist_for_each_entry_safe(child, t, &clk->core->children,
- child_node)
- clk_core_set_parent_nolock(child, NULL);
- }
- clk_core_evict_parent_cache(clk->core);
- hlist_del_init(&clk->core->child_node);
- if (clk->core->prepare_count)
- pr_warn("%s: unregistering prepared clock: %s\n",
- __func__, clk->core->name);
- if (clk->core->protect_count)
- pr_warn("%s: unregistering protected clock: %s\n",
- __func__, clk->core->name);
- kref_put(&clk->core->ref, __clk_release);
- free_clk(clk);
- unlock:
- clk_prepare_unlock();
- }
- EXPORT_SYMBOL_GPL(clk_unregister);
- /**
- * clk_hw_unregister - unregister a currently registered clk_hw
- * @hw: hardware-specific clock data to unregister
- */
- void clk_hw_unregister(struct clk_hw *hw)
- {
- clk_unregister(hw->clk);
- }
- EXPORT_SYMBOL_GPL(clk_hw_unregister);
- static void devm_clk_unregister_cb(struct device *dev, void *res)
- {
- clk_unregister(*(struct clk **)res);
- }
- static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
- {
- clk_hw_unregister(*(struct clk_hw **)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)
- {
- struct clk *clk;
- struct clk **clkp;
- clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
- if (!clkp)
- return ERR_PTR(-ENOMEM);
- clk = clk_register(dev, hw);
- if (!IS_ERR(clk)) {
- *clkp = clk;
- devres_add(dev, clkp);
- } else {
- devres_free(clkp);
- }
- return clk;
- }
- EXPORT_SYMBOL_GPL(devm_clk_register);
- /**
- * 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)
- {
- struct clk_hw **hwp;
- int ret;
- hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
- if (!hwp)
- return -ENOMEM;
- ret = clk_hw_register(dev, hw);
- if (!ret) {
- *hwp = hw;
- devres_add(dev, hwp);
- } else {
- devres_free(hwp);
- }
- return ret;
- }
- EXPORT_SYMBOL_GPL(devm_clk_hw_register);
- static void devm_clk_release(struct device *dev, void *res)
- {
- clk_put(*(struct clk **)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)
- {
- struct clk *clk;
- struct clk **clkp;
- /* This should not happen because it would mean we have drivers
- * passing around clk_hw pointers instead of having the caller use
- * proper clk_get() style APIs
- */
- WARN_ON_ONCE(dev != hw->core->dev);
- clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
- if (!clkp)
- return ERR_PTR(-ENOMEM);
- clk = clk_hw_get_clk(hw, con_id);
- if (!IS_ERR(clk)) {
- *clkp = clk;
- devres_add(dev, clkp);
- } else {
- devres_free(clkp);
- }
- return clk;
- }
- EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
- /*
- * clkdev helpers
- */
- void __clk_put(struct clk *clk)
- {
- struct module *owner;
- if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
- return;
- clk_prepare_lock();
- /*
- * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
- * given user should be balanced with calls to clk_rate_exclusive_put()
- * and by that same consumer
- */
- if (WARN_ON(clk->exclusive_count)) {
- /* We voiced our concern, let's sanitize the situation */
- clk->core->protect_count -= (clk->exclusive_count - 1);
- clk_core_rate_unprotect(clk->core);
- clk->exclusive_count = 0;
- }
- hlist_del(&clk->clks_node);
- /* If we had any boundaries on that clock, let's drop them. */
- if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
- clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
- owner = clk->core->owner;
- kref_put(&clk->core->ref, __clk_release);
- clk_prepare_unlock();
- module_put(owner);
- free_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)
- {
- struct clk_notifier *cn;
- int ret = -ENOMEM;
- if (!clk || !nb)
- return -EINVAL;
- clk_prepare_lock();
- /* search the list of notifiers for this clk */
- list_for_each_entry(cn, &clk_notifier_list, node)
- if (cn->clk == clk)
- goto found;
- /* if clk wasn't in the notifier list, allocate new clk_notifier */
- cn = kzalloc(sizeof(*cn), GFP_KERNEL);
- if (!cn)
- goto out;
- cn->clk = clk;
- srcu_init_notifier_head(&cn->notifier_head);
- list_add(&cn->node, &clk_notifier_list);
- found:
- ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
- clk->core->notifier_count++;
- out:
- clk_prepare_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(clk_notifier_register);
- /**
- * 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)
- {
- struct clk_notifier *cn;
- int ret = -ENOENT;
- if (!clk || !nb)
- return -EINVAL;
- clk_prepare_lock();
- list_for_each_entry(cn, &clk_notifier_list, node) {
- if (cn->clk == clk) {
- ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
- clk->core->notifier_count--;
- /* XXX the notifier code should handle this better */
- if (!cn->notifier_head.head) {
- srcu_cleanup_notifier_head(&cn->notifier_head);
- list_del(&cn->node);
- kfree(cn);
- }
- break;
- }
- }
- clk_prepare_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(clk_notifier_unregister);
- struct clk_notifier_devres {
- struct clk *clk;
- struct notifier_block *nb;
- };
- static void devm_clk_notifier_release(struct device *dev, void *res)
- {
- struct clk_notifier_devres *devres = res;
- clk_notifier_unregister(devres->clk, devres->nb);
- }
- int devm_clk_notifier_register(struct device *dev, struct clk *clk,
- struct notifier_block *nb)
- {
- struct clk_notifier_devres *devres;
- int ret;
- devres = devres_alloc(devm_clk_notifier_release,
- sizeof(*devres), GFP_KERNEL);
- if (!devres)
- return -ENOMEM;
- ret = clk_notifier_register(clk, nb);
- if (!ret) {
- devres->clk = clk;
- devres->nb = nb;
- devres_add(dev, devres);
- } else {
- devres_free(devres);
- }
- return ret;
- }
- EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
- #ifdef CONFIG_OF
- static void clk_core_reparent_orphans(void)
- {
- clk_prepare_lock();
- clk_core_reparent_orphans_nolock();
- clk_prepare_unlock();
- }
- /**
- * 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 {
- struct list_head link;
- struct device_node *node;
- struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
- struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
- void *data;
- };
- extern struct of_device_id __clk_of_table;
- static const struct of_device_id __clk_of_table_sentinel
- __used __section("__clk_of_table_end");
- 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)
- {
- return data;
- }
- EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
- struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
- {
- return data;
- }
- EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
- struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
- {
- struct clk_onecell_data *clk_data = data;
- unsigned int idx = clkspec->args[0];
- if (idx >= clk_data->clk_num) {
- pr_err("%s: invalid clock index %u\n", __func__, idx);
- return ERR_PTR(-EINVAL);
- }
- return clk_data->clks[idx];
- }
- EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
- struct clk_hw *
- of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
- {
- struct clk_hw_onecell_data *hw_data = data;
- unsigned int idx = clkspec->args[0];
- if (idx >= hw_data->num) {
- pr_err("%s: invalid index %u\n", __func__, idx);
- return ERR_PTR(-EINVAL);
- }
- return hw_data->hws[idx];
- }
- EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
- /**
- * 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)
- {
- struct of_clk_provider *cp;
- int ret;
- if (!np)
- return 0;
- cp = kzalloc(sizeof(*cp), GFP_KERNEL);
- if (!cp)
- return -ENOMEM;
- cp->node = of_node_get(np);
- cp->data = data;
- cp->get = clk_src_get;
- mutex_lock(&of_clk_mutex);
- list_add(&cp->link, &of_clk_providers);
- mutex_unlock(&of_clk_mutex);
- pr_debug("Added clock from %pOF\n", np);
- clk_core_reparent_orphans();
- ret = of_clk_set_defaults(np, true);
- if (ret < 0)
- of_clk_del_provider(np);
- fwnode_dev_initialized(&np->fwnode, true);
- return ret;
- }
- EXPORT_SYMBOL_GPL(of_clk_add_provider);
- /**
- * 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)
- {
- struct of_clk_provider *cp;
- int ret;
- if (!np)
- return 0;
- cp = kzalloc(sizeof(*cp), GFP_KERNEL);
- if (!cp)
- return -ENOMEM;
- cp->node = of_node_get(np);
- cp->data = data;
- cp->get_hw = get;
- mutex_lock(&of_clk_mutex);
- list_add(&cp->link, &of_clk_providers);
- mutex_unlock(&of_clk_mutex);
- pr_debug("Added clk_hw provider from %pOF\n", np);
- clk_core_reparent_orphans();
- ret = of_clk_set_defaults(np, true);
- if (ret < 0)
- of_clk_del_provider(np);
- fwnode_dev_initialized(&np->fwnode, true);
- return ret;
- }
- EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
- static void devm_of_clk_release_provider(struct device *dev, void *res)
- {
- of_clk_del_provider(*(struct device_node **)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)
- {
- struct device_node *np, *parent_np;
- np = dev->of_node;
- parent_np = dev->parent ? dev->parent->of_node : NULL;
- if (!of_find_property(np, "#clock-cells", NULL))
- if (of_find_property(parent_np, "#clock-cells", NULL))
- np = parent_np;
- return np;
- }
- /**
- * 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)
- {
- struct device_node **ptr, *np;
- int ret;
- ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
- GFP_KERNEL);
- if (!ptr)
- return -ENOMEM;
- np = get_clk_provider_node(dev);
- ret = of_clk_add_hw_provider(np, get, data);
- if (!ret) {
- *ptr = np;
- devres_add(dev, ptr);
- } else {
- devres_free(ptr);
- }
- return ret;
- }
- EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
- /**
- * 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)
- {
- struct of_clk_provider *cp;
- if (!np)
- return;
- mutex_lock(&of_clk_mutex);
- list_for_each_entry(cp, &of_clk_providers, link) {
- if (cp->node == np) {
- list_del(&cp->link);
- fwnode_dev_initialized(&np->fwnode, false);
- of_node_put(cp->node);
- kfree(cp);
- break;
- }
- }
- mutex_unlock(&of_clk_mutex);
- }
- EXPORT_SYMBOL_GPL(of_clk_del_provider);
- /**
- * 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)
- {
- int ret = -ENOENT;
- /* Walk up the tree of devices looking for a clock property that matches */
- while (np) {
- /*
- * For named clocks, first look up the name in the
- * "clock-names" property. If it cannot be found, then index
- * will be an error code and of_parse_phandle_with_args() will
- * return -EINVAL.
- */
- if (name)
- index = of_property_match_string(np, "clock-names", name);
- ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
- index, out_args);
- if (!ret)
- break;
- if (name && index >= 0)
- break;
- /*
- * No matching clock found on this node. If the parent node
- * has a "clock-ranges" property, then we can try one of its
- * clocks.
- */
- np = np->parent;
- if (np && !of_get_property(np, "clock-ranges", NULL))
- break;
- index = 0;
- }
- return ret;
- }
- static struct clk_hw *
- __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
- struct of_phandle_args *clkspec)
- {
- struct clk *clk;
- if (provider->get_hw)
- return provider->get_hw(clkspec, provider->data);
- clk = provider->get(clkspec, provider->data);
- if (IS_ERR(clk))
- return ERR_CAST(clk);
- return __clk_get_hw(clk);
- }
- static struct clk_hw *
- of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
- {
- struct of_clk_provider *provider;
- struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
- if (!clkspec)
- return ERR_PTR(-EINVAL);
- mutex_lock(&of_clk_mutex);
- list_for_each_entry(provider, &of_clk_providers, link) {
- if (provider->node == clkspec->np) {
- hw = __of_clk_get_hw_from_provider(provider, clkspec);
- if (!IS_ERR(hw))
- break;
- }
- }
- mutex_unlock(&of_clk_mutex);
- return hw;
- }
- /**
- * 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)
- {
- struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
- return clk_hw_create_clk(NULL, hw, NULL, __func__);
- }
- EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
- struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
- const char *con_id)
- {
- int ret;
- struct clk_hw *hw;
- struct of_phandle_args clkspec;
- ret = of_parse_clkspec(np, index, con_id, &clkspec);
- if (ret)
- return ERR_PTR(ret);
- hw = of_clk_get_hw_from_clkspec(&clkspec);
- of_node_put(clkspec.np);
- return hw;
- }
- static struct clk *__of_clk_get(struct device_node *np,
- int index, const char *dev_id,
- const char *con_id)
- {
- struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
- return clk_hw_create_clk(NULL, hw, dev_id, con_id);
- }
- struct clk *of_clk_get(struct device_node *np, int index)
- {
- return __of_clk_get(np, index, np->full_name, NULL);
- }
- EXPORT_SYMBOL(of_clk_get);
- /**
- * 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)
- {
- if (!np)
- return ERR_PTR(-ENOENT);
- return __of_clk_get(np, 0, np->full_name, name);
- }
- EXPORT_SYMBOL(of_clk_get_by_name);
- /**
- * 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)
- {
- int count;
- count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
- if (count < 0)
- return 0;
- return count;
- }
- EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
- const char *of_clk_get_parent_name(const struct device_node *np, int index)
- {
- struct of_phandle_args clkspec;
- struct property *prop;
- const char *clk_name;
- const __be32 *vp;
- u32 pv;
- int rc;
- int count;
- struct clk *clk;
- rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
- &clkspec);
- if (rc)
- return NULL;
- index = clkspec.args_count ? clkspec.args[0] : 0;
- count = 0;
- /* if there is an indices property, use it to transfer the index
- * specified into an array offset for the clock-output-names property.
- */
- of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
- if (index == pv) {
- index = count;
- break;
- }
- count++;
- }
- /* We went off the end of 'clock-indices' without finding it */
- if (prop && !vp)
- return NULL;
- if (of_property_read_string_index(clkspec.np, "clock-output-names",
- index,
- &clk_name) < 0) {
- /*
- * Best effort to get the name if the clock has been
- * registered with the framework. If the clock isn't
- * registered, we return the node name as the name of
- * the clock as long as #clock-cells = 0.
- */
- clk = of_clk_get_from_provider(&clkspec);
- if (IS_ERR(clk)) {
- if (clkspec.args_count == 0)
- clk_name = clkspec.np->name;
- else
- clk_name = NULL;
- } else {
- clk_name = __clk_get_name(clk);
- clk_put(clk);
- }
- }
- of_node_put(clkspec.np);
- return clk_name;
- }
- EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
- /**
- * 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)
- {
- unsigned int i = 0;
- while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
- i++;
- return i;
- }
- EXPORT_SYMBOL_GPL(of_clk_parent_fill);
- struct clock_provider {
- void (*clk_init_cb)(struct device_node *);
- struct device_node *np;
- struct list_head node;
- };
- /*
- * 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)
- {
- int i = 0;
- while (true) {
- struct clk *clk = of_clk_get(np, i);
- /* this parent is ready we can check the next one */
- if (!IS_ERR(clk)) {
- clk_put(clk);
- i++;
- continue;
- }
- /* at least one parent is not ready, we exit now */
- if (PTR_ERR(clk) == -EPROBE_DEFER)
- return 0;
- /*
- * Here we make assumption that the device tree is
- * written correctly. So an error means that there is
- * no more parent. As we didn't exit yet, then the
- * previous parent are ready. If there is no clock
- * parent, no need to wait for them, then we can
- * consider their absence as being ready
- */
- return 1;
- }
- }
- /**
- * 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)
- {
- struct property *prop;
- const __be32 *cur;
- uint32_t idx;
- if (!np || !flags)
- return -EINVAL;
- of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
- if (index == idx)
- *flags |= CLK_IS_CRITICAL;
- return 0;
- }
- /**
- * 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)
- {
- const struct of_device_id *match;
- struct device_node *np;
- struct clock_provider *clk_provider, *next;
- bool is_init_done;
- bool force = false;
- LIST_HEAD(clk_provider_list);
- if (!matches)
- matches = &__clk_of_table;
- /* First prepare the list of the clocks providers */
- for_each_matching_node_and_match(np, matches, &match) {
- struct clock_provider *parent;
- if (!of_device_is_available(np))
- continue;
- parent = kzalloc(sizeof(*parent), GFP_KERNEL);
- if (!parent) {
- list_for_each_entry_safe(clk_provider, next,
- &clk_provider_list, node) {
- list_del(&clk_provider->node);
- of_node_put(clk_provider->np);
- kfree(clk_provider);
- }
- of_node_put(np);
- return;
- }
- parent->clk_init_cb = match->data;
- parent->np = of_node_get(np);
- list_add_tail(&parent->node, &clk_provider_list);
- }
- while (!list_empty(&clk_provider_list)) {
- is_init_done = false;
- list_for_each_entry_safe(clk_provider, next,
- &clk_provider_list, node) {
- if (force || parent_ready(clk_provider->np)) {
- /* Don't populate platform devices */
- of_node_set_flag(clk_provider->np,
- OF_POPULATED);
- clk_provider->clk_init_cb(clk_provider->np);
- of_clk_set_defaults(clk_provider->np, true);
- list_del(&clk_provider->node);
- of_node_put(clk_provider->np);
- kfree(clk_provider);
- is_init_done = true;
- }
- }
- /*
- * We didn't manage to initialize any of the
- * remaining providers during the last loop, so now we
- * initialize all the remaining ones unconditionally
- * in case the clock parent was not mandatory
- */
- if (!is_init_done)
- force = true;
- }
- }
- #endif
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