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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
  * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
  *
  * 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;
     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;
 }
 
 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;
     struct clk_rate_request parent_req = *req;
 
     /* 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) {
             ret = __clk_determine_rate(parent ? parent->hw : NULL,
                            &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++) {
         parent = clk_core_get_parent_by_index(core, i);
         if (!parent)
             continue;
 
         if (core->flags & CLK_SET_RATE_PARENT) {
             parent_req = *req;
             ret = __clk_determine_rate(parent->hw, &parent_req);
             if (ret)
                 continue;
         } else {
             parent_req.rate = clk_core_get_rate_nolock(parent);
         }
 
         if (mux_is_better_rate(req->rate, parent_req.rate,
                        best, flags)) {
             best_parent = parent;
             best = parent_req.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);
 }
 
 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 (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 (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 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;
 
     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)
 {
     struct clk_core *parent;
 
     if (WARN_ON(!core || !req))
         return;
 
     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;
     }
 }
 
 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)
 {
     lockdep_assert_held(&prepare_lock);
 
     if (!core) {
         req->rate = 0;
         return 0;
     }
 
     clk_core_init_rate_req(core, req);
 
     if (clk_core_can_round(core))
         return clk_core_determine_round_nolock(core, req);
     else if (core->flags & CLK_SET_RATE_PARENT)
         return clk_core_round_rate_nolock(core->parent, req);
 
     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_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
     req.rate = 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_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
     req.rate = 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
  * @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, 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);
 
     /*
      * 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, 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, 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.
  * If clk is NULL 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);
 
 /*
  * 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;
 
         req.rate = rate;
         req.min_rate = min_rate;
         req.max_rate = max_rate;
 
         clk_core_init_rate_req(core, &req);
 
         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;
     }
 
     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);
 
     /*
      * 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_get_boundaries(core, &req.min_rate, &req.max_rate);
     req.rate = 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 = 0;
 
     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);
 
 /**
  * clk_set_rate_range - set a rate range for a clock source
  * @clk: clock source
  * @min: desired minimum clock rate in Hz, inclusive
  * @max: desired maximum clock rate in Hz, inclusive
  *
  * Returns success (0) or negative errno.
  */
 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
 {
     int ret = 0;
     unsigned long old_min, old_max, rate;
 
     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;
     }
 
     clk_prepare_lock();
 
     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;
     }
 
     /*
      * 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(clk->core->req_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);
 
     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, 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(struct clk *clk, struct clk *parent)
 {
     struct clk_core *core, *parent_core;
     int i;
 
     /* NULL clocks should be nops, so return success if either is NULL. */
     if (!clk || !parent)
         return true;
 
     core = clk->core;
     parent_core = parent->core;
 
     /* Optimize for the case where the parent is already the parent. */
     if (core->parent == parent_core)
         return true;
 
     for (i = 0; i < core->num_parents; i++)
         if (!strcmp(core->parents[i].name, parent_core->name))
             return true;
 
     return false;
 }
 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, ABORT_RATE_CHANGE);
     } else {
         __clk_recalc_rates(core, 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);
 
 #undef CLOCK_ALLOW_WRITE_DEBUGFS
 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
 /*
  * This can be dangerous, therefore don't provide any real compile time
  * configuration option for this feature.
  * People who want to use this will need to modify the source code directly.
  */
 static int clk_rate_set(void *data, u64 val)
 {
     struct clk_core *core = data;
     int ret;
 
     clk_prepare_lock();
     ret = clk_core_set_rate_nolock(core, val);
     clk_prepare_unlock();
 
     return ret;
 }
 
 #define clk_rate_mode   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;
 
     /*
      * 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)
         seq_puts(s,
              of_clk_get_parent_name(core->of_node,
                         core->parents[i].index));
     else
         seq_puts(s, "(missing)");
 
     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,
                     &current_parent_rw_fops);
     else
 #endif
     if (core->num_parents > 0)
         debugfs_create_file("clk_parent", 0444, root, core,
                     &current_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;
 
 #ifdef CLOCK_ALLOW_WRITE_DEBUGFS
     pr_warn("\n");
     pr_warn("********************************************************************\n");
     pr_warn("**     NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE           **\n");
     pr_warn("**                                                                **\n");
     pr_warn("**  WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
     pr_warn("**                                                                **\n");
     pr_warn("** This means that this kernel is built to expose clk operations  **\n");
     pr_warn("** such as parent or rate setting, enabling, disabling, etc.      **\n");
     pr_warn("** to userspace, which may compromise security on your system.    **\n");
     pr_warn("**                                                                **\n");
     pr_warn("** If you see this message and you are not debugging the          **\n");
     pr_warn("** kernel, report this immediately to your vendor!                **\n");
     pr_warn("**                                                                **\n");
     pr_warn("**     NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE           **\n");
     pr_warn("********************************************************************\n");
 #endif
 
     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
          * 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, 0);
 
             /*
              * __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;
 
     /*
      * 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_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 (clk->min_rate > clk->core->req_rate ||
         clk->max_rate < clk->core->req_rate)
         clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
 
     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;
     } 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);
 
 static int devm_clk_provider_match(struct device *dev, void *res, void *data)
 {
     struct device_node **np = res;
 
     if (WARN_ON(!np || !*np))
         return 0;
 
     return *np == data;
 }
 
 /**
  * devm_of_clk_del_provider() - Remove clock provider registered using devm
  * @dev: Device to whose lifetime the clock provider was bound
  */
 void devm_of_clk_del_provider(struct device *dev)
 {
     int ret;
     struct device_node *np = get_clk_provider_node(dev);
 
     ret = devres_release(dev, devm_of_clk_release_provider,
                  devm_clk_provider_match, np);
 
     WARN_ON(ret);
 }
 EXPORT_SYMBOL(devm_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