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Merge branch 'clk-exynos-cpu-clk' into clk-next
[uclinux-h8/linux.git] / drivers / clk / clk.c
index 0c0124c..059e5d2 100644 (file)
@@ -21,6 +21,7 @@
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/clkdev.h>
 
 #include "clk.h"
 
@@ -37,13 +38,6 @@ static HLIST_HEAD(clk_root_list);
 static HLIST_HEAD(clk_orphan_list);
 static LIST_HEAD(clk_notifier_list);
 
-static long clk_core_get_accuracy(struct clk_core *clk);
-static unsigned long clk_core_get_rate(struct clk_core *clk);
-static int clk_core_get_phase(struct clk_core *clk);
-static bool clk_core_is_prepared(struct clk_core *clk);
-static bool clk_core_is_enabled(struct clk_core *clk);
-static struct clk_core *clk_core_lookup(const char *name);
-
 /***    private data structures    ***/
 
 struct clk_core {
@@ -68,11 +62,11 @@ struct clk_core {
        int                     phase;
        struct hlist_head       children;
        struct hlist_node       child_node;
-       struct hlist_node       debug_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;
 };
@@ -145,516 +139,248 @@ static void clk_enable_unlock(unsigned long flags)
        spin_unlock_irqrestore(&enable_lock, flags);
 }
 
-/***        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 *all_lists[] = {
-       &clk_root_list,
-       &clk_orphan_list,
-       NULL,
-};
+static bool clk_core_is_prepared(struct clk_core *core)
+{
+       /*
+        * .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;
 
-static struct hlist_head *orphan_list[] = {
-       &clk_orphan_list,
-       NULL,
-};
+       return core->ops->is_prepared(core->hw);
+}
 
-static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
-                                int level)
+static bool clk_core_is_enabled(struct clk_core *core)
 {
-       if (!c)
-               return;
+       /*
+        * .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;
 
-       seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
-                  level * 3 + 1, "",
-                  30 - level * 3, c->name,
-                  c->enable_count, c->prepare_count, clk_core_get_rate(c),
-                  clk_core_get_accuracy(c), clk_core_get_phase(c));
+       return core->ops->is_enabled(core->hw);
 }
 
-static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
-                                    int level)
+static void clk_unprepare_unused_subtree(struct clk_core *core)
 {
        struct clk_core *child;
 
-       if (!c)
+       lockdep_assert_held(&prepare_lock);
+
+       hlist_for_each_entry(child, &core->children, child_node)
+               clk_unprepare_unused_subtree(child);
+
+       if (core->prepare_count)
                return;
 
-       clk_summary_show_one(s, c, level);
+       if (core->flags & CLK_IGNORE_UNUSED)
+               return;
 
-       hlist_for_each_entry(child, &c->children, child_node)
-               clk_summary_show_subtree(s, child, level + 1);
+       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);
+       }
 }
 
-static int clk_summary_show(struct seq_file *s, void *data)
+static void clk_disable_unused_subtree(struct clk_core *core)
 {
-       struct clk_core *c;
-       struct hlist_head **lists = (struct hlist_head **)s->private;
+       struct clk_core *child;
+       unsigned long flags;
 
-       seq_puts(s, "   clock                         enable_cnt  prepare_cnt        rate   accuracy   phase\n");
-       seq_puts(s, "----------------------------------------------------------------------------------------\n");
+       lockdep_assert_held(&prepare_lock);
 
-       clk_prepare_lock();
+       hlist_for_each_entry(child, &core->children, child_node)
+               clk_disable_unused_subtree(child);
 
-       for (; *lists; lists++)
-               hlist_for_each_entry(c, *lists, child_node)
-                       clk_summary_show_subtree(s, c, 0);
+       flags = clk_enable_lock();
 
-       clk_prepare_unlock();
+       if (core->enable_count)
+               goto unlock_out;
 
-       return 0;
-}
+       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);
+       }
 
-static int clk_summary_open(struct inode *inode, struct file *file)
-{
-       return single_open(file, clk_summary_show, inode->i_private);
+unlock_out:
+       clk_enable_unlock(flags);
 }
 
-static const struct file_operations clk_summary_fops = {
-       .open           = clk_summary_open,
-       .read           = seq_read,
-       .llseek         = seq_lseek,
-       .release        = single_release,
-};
-
-static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
+static bool clk_ignore_unused;
+static int __init clk_ignore_unused_setup(char *__unused)
 {
-       if (!c)
-               return;
-
-       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, "\"rate\": %lu", clk_core_get_rate(c));
-       seq_printf(s, "\"accuracy\": %lu", clk_core_get_accuracy(c));
-       seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
+       clk_ignore_unused = true;
+       return 1;
 }
+__setup("clk_ignore_unused", clk_ignore_unused_setup);
 
-static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
+static int clk_disable_unused(void)
 {
-       struct clk_core *child;
-
-       if (!c)
-               return;
-
-       clk_dump_one(s, c, level);
+       struct clk_core *core;
 
-       hlist_for_each_entry(child, &c->children, child_node) {
-               seq_printf(s, ",");
-               clk_dump_subtree(s, child, level + 1);
+       if (clk_ignore_unused) {
+               pr_warn("clk: Not disabling unused clocks\n");
+               return 0;
        }
 
-       seq_printf(s, "}");
-}
+       clk_prepare_lock();
 
-static int clk_dump(struct seq_file *s, void *data)
-{
-       struct clk_core *c;
-       bool first_node = true;
-       struct hlist_head **lists = (struct hlist_head **)s->private;
+       hlist_for_each_entry(core, &clk_root_list, child_node)
+               clk_disable_unused_subtree(core);
 
-       seq_printf(s, "{");
+       hlist_for_each_entry(core, &clk_orphan_list, child_node)
+               clk_disable_unused_subtree(core);
 
-       clk_prepare_lock();
+       hlist_for_each_entry(core, &clk_root_list, child_node)
+               clk_unprepare_unused_subtree(core);
 
-       for (; *lists; lists++) {
-               hlist_for_each_entry(c, *lists, child_node) {
-                       if (!first_node)
-                               seq_puts(s, ",");
-                       first_node = false;
-                       clk_dump_subtree(s, c, 0);
-               }
-       }
+       hlist_for_each_entry(core, &clk_orphan_list, child_node)
+               clk_unprepare_unused_subtree(core);
 
        clk_prepare_unlock();
 
-       seq_printf(s, "}");
        return 0;
 }
+late_initcall_sync(clk_disable_unused);
 
+/***    helper functions   ***/
 
-static int clk_dump_open(struct inode *inode, struct file *file)
+const char *__clk_get_name(struct clk *clk)
 {
-       return single_open(file, clk_dump, inode->i_private);
+       return !clk ? NULL : clk->core->name;
 }
+EXPORT_SYMBOL_GPL(__clk_get_name);
 
-static const struct file_operations clk_dump_fops = {
-       .open           = clk_dump_open,
-       .read           = seq_read,
-       .llseek         = seq_lseek,
-       .release        = single_release,
-};
-
-static int clk_debug_create_one(struct clk_core *clk, struct dentry *pdentry)
+struct clk_hw *__clk_get_hw(struct clk *clk)
 {
-       struct dentry *d;
-       int ret = -ENOMEM;
-
-       if (!clk || !pdentry) {
-               ret = -EINVAL;
-               goto out;
-       }
+       return !clk ? NULL : clk->core->hw;
+}
+EXPORT_SYMBOL_GPL(__clk_get_hw);
 
-       d = debugfs_create_dir(clk->name, pdentry);
-       if (!d)
-               goto out;
+u8 __clk_get_num_parents(struct clk *clk)
+{
+       return !clk ? 0 : clk->core->num_parents;
+}
+EXPORT_SYMBOL_GPL(__clk_get_num_parents);
 
-       clk->dentry = d;
+struct clk *__clk_get_parent(struct clk *clk)
+{
+       if (!clk)
+               return NULL;
 
-       d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry,
-                       (u32 *)&clk->rate);
-       if (!d)
-               goto err_out;
+       /* TODO: Create a per-user clk and change callers to call clk_put */
+       return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
+}
+EXPORT_SYMBOL_GPL(__clk_get_parent);
 
-       d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry,
-                       (u32 *)&clk->accuracy);
-       if (!d)
-               goto err_out;
+static struct clk_core *__clk_lookup_subtree(const char *name,
+                                            struct clk_core *core)
+{
+       struct clk_core *child;
+       struct clk_core *ret;
 
-       d = debugfs_create_u32("clk_phase", S_IRUGO, clk->dentry,
-                       (u32 *)&clk->phase);
-       if (!d)
-               goto err_out;
+       if (!strcmp(core->name, name))
+               return core;
 
-       d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry,
-                       (u32 *)&clk->flags);
-       if (!d)
-               goto err_out;
+       hlist_for_each_entry(child, &core->children, child_node) {
+               ret = __clk_lookup_subtree(name, child);
+               if (ret)
+                       return ret;
+       }
 
-       d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry,
-                       (u32 *)&clk->prepare_count);
-       if (!d)
-               goto err_out;
+       return NULL;
+}
 
-       d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry,
-                       (u32 *)&clk->enable_count);
-       if (!d)
-               goto err_out;
+static struct clk_core *clk_core_lookup(const char *name)
+{
+       struct clk_core *root_clk;
+       struct clk_core *ret;
 
-       d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry,
-                       (u32 *)&clk->notifier_count);
-       if (!d)
-               goto err_out;
+       if (!name)
+               return NULL;
 
-       if (clk->ops->debug_init) {
-               ret = clk->ops->debug_init(clk->hw, clk->dentry);
+       /* 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)
-                       goto err_out;
+                       return ret;
        }
 
-       ret = 0;
-       goto out;
+       /* 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;
+       }
 
-err_out:
-       debugfs_remove_recursive(clk->dentry);
-       clk->dentry = NULL;
-out:
-       return ret;
+       return NULL;
 }
 
-/**
- * clk_debug_register - add a clk node to the debugfs clk tree
- * @clk: the clk being added to the debugfs clk tree
- *
- * Dynamically adds a clk to the debugfs clk tree if debugfs has been
- * initialized.  Otherwise it bails out early since the debugfs clk tree
- * will be created lazily by clk_debug_init as part of a late_initcall.
- */
-static int clk_debug_register(struct clk_core *clk)
+static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
+                                                        u8 index)
 {
-       int ret = 0;
+       if (!core || index >= core->num_parents)
+               return NULL;
+       else if (!core->parents)
+               return clk_core_lookup(core->parent_names[index]);
+       else if (!core->parents[index])
+               return core->parents[index] =
+                       clk_core_lookup(core->parent_names[index]);
+       else
+               return core->parents[index];
+}
 
-       mutex_lock(&clk_debug_lock);
-       hlist_add_head(&clk->debug_node, &clk_debug_list);
+struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
+{
+       struct clk_core *parent;
 
-       if (!inited)
-               goto unlock;
+       if (!clk)
+               return NULL;
 
-       ret = clk_debug_create_one(clk, rootdir);
-unlock:
-       mutex_unlock(&clk_debug_lock);
+       parent = clk_core_get_parent_by_index(clk->core, index);
 
-       return ret;
+       return !parent ? NULL : parent->hw->clk;
 }
+EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
 
- /**
- * clk_debug_unregister - remove a clk node from the debugfs clk tree
- * @clk: the clk being removed from the debugfs clk tree
- *
- * Dynamically removes a clk and all it's children clk nodes from the
- * debugfs clk tree if clk->dentry points to debugfs created by
- * clk_debug_register in __clk_init.
- */
-static void clk_debug_unregister(struct clk_core *clk)
+unsigned int __clk_get_enable_count(struct clk *clk)
 {
-       mutex_lock(&clk_debug_lock);
-       hlist_del_init(&clk->debug_node);
-       debugfs_remove_recursive(clk->dentry);
-       clk->dentry = NULL;
-       mutex_unlock(&clk_debug_lock);
+       return !clk ? 0 : clk->core->enable_count;
 }
 
-struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
-                               void *data, const struct file_operations *fops)
-{
-       struct dentry *d = NULL;
-
-       if (hw->core->dentry)
-               d = debugfs_create_file(name, mode, hw->core->dentry, data,
-                                       fops);
-
-       return d;
-}
-EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
-
-/**
- * clk_debug_init - lazily create the debugfs clk tree visualization
- *
- * clks are often initialized very early during boot before memory can
- * be dynamically allocated and well before debugfs is setup.
- * clk_debug_init walks the clk tree hierarchy while holding
- * prepare_lock and creates the topology as part of a late_initcall,
- * thus insuring that clks initialized very early will still be
- * represented in the debugfs clk tree.  This function should only be
- * called once at boot-time, and all other clks added dynamically will
- * be done so with clk_debug_register.
- */
-static int __init clk_debug_init(void)
-{
-       struct clk_core *clk;
-       struct dentry *d;
-
-       rootdir = debugfs_create_dir("clk", NULL);
-
-       if (!rootdir)
-               return -ENOMEM;
-
-       d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
-                               &clk_summary_fops);
-       if (!d)
-               return -ENOMEM;
-
-       d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
-                               &clk_dump_fops);
-       if (!d)
-               return -ENOMEM;
-
-       d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
-                               &orphan_list, &clk_summary_fops);
-       if (!d)
-               return -ENOMEM;
-
-       d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
-                               &orphan_list, &clk_dump_fops);
-       if (!d)
-               return -ENOMEM;
-
-       mutex_lock(&clk_debug_lock);
-       hlist_for_each_entry(clk, &clk_debug_list, debug_node)
-               clk_debug_create_one(clk, rootdir);
-
-       inited = 1;
-       mutex_unlock(&clk_debug_lock);
-
-       return 0;
-}
-late_initcall(clk_debug_init);
-#else
-static inline int clk_debug_register(struct clk_core *clk) { return 0; }
-static inline void clk_debug_reparent(struct clk_core *clk,
-                                     struct clk_core *new_parent)
-{
-}
-static inline void clk_debug_unregister(struct clk_core *clk)
-{
-}
-#endif
-
-/* caller must hold prepare_lock */
-static void clk_unprepare_unused_subtree(struct clk_core *clk)
-{
-       struct clk_core *child;
-
-       lockdep_assert_held(&prepare_lock);
-
-       hlist_for_each_entry(child, &clk->children, child_node)
-               clk_unprepare_unused_subtree(child);
-
-       if (clk->prepare_count)
-               return;
-
-       if (clk->flags & CLK_IGNORE_UNUSED)
-               return;
-
-       if (clk_core_is_prepared(clk)) {
-               trace_clk_unprepare(clk);
-               if (clk->ops->unprepare_unused)
-                       clk->ops->unprepare_unused(clk->hw);
-               else if (clk->ops->unprepare)
-                       clk->ops->unprepare(clk->hw);
-               trace_clk_unprepare_complete(clk);
-       }
-}
-
-/* caller must hold prepare_lock */
-static void clk_disable_unused_subtree(struct clk_core *clk)
-{
-       struct clk_core *child;
-       unsigned long flags;
-
-       lockdep_assert_held(&prepare_lock);
-
-       hlist_for_each_entry(child, &clk->children, child_node)
-               clk_disable_unused_subtree(child);
-
-       flags = clk_enable_lock();
-
-       if (clk->enable_count)
-               goto unlock_out;
-
-       if (clk->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(clk)) {
-               trace_clk_disable(clk);
-               if (clk->ops->disable_unused)
-                       clk->ops->disable_unused(clk->hw);
-               else if (clk->ops->disable)
-                       clk->ops->disable(clk->hw);
-               trace_clk_disable_complete(clk);
-       }
-
-unlock_out:
-       clk_enable_unlock(flags);
-}
-
-static bool clk_ignore_unused;
-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 clk_disable_unused(void)
-{
-       struct clk_core *clk;
-
-       if (clk_ignore_unused) {
-               pr_warn("clk: Not disabling unused clocks\n");
-               return 0;
-       }
-
-       clk_prepare_lock();
-
-       hlist_for_each_entry(clk, &clk_root_list, child_node)
-               clk_disable_unused_subtree(clk);
-
-       hlist_for_each_entry(clk, &clk_orphan_list, child_node)
-               clk_disable_unused_subtree(clk);
-
-       hlist_for_each_entry(clk, &clk_root_list, child_node)
-               clk_unprepare_unused_subtree(clk);
-
-       hlist_for_each_entry(clk, &clk_orphan_list, child_node)
-               clk_unprepare_unused_subtree(clk);
-
-       clk_prepare_unlock();
-
-       return 0;
-}
-late_initcall_sync(clk_disable_unused);
-
-/***    helper functions   ***/
-
-const char *__clk_get_name(struct clk *clk)
-{
-       return !clk ? NULL : clk->core->name;
-}
-EXPORT_SYMBOL_GPL(__clk_get_name);
-
-struct clk_hw *__clk_get_hw(struct clk *clk)
-{
-       return !clk ? NULL : clk->core->hw;
-}
-EXPORT_SYMBOL_GPL(__clk_get_hw);
-
-u8 __clk_get_num_parents(struct clk *clk)
-{
-       return !clk ? 0 : clk->core->num_parents;
-}
-EXPORT_SYMBOL_GPL(__clk_get_num_parents);
-
-struct clk *__clk_get_parent(struct clk *clk)
-{
-       if (!clk)
-               return NULL;
-
-       /* TODO: Create a per-user clk and change callers to call clk_put */
-       return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
-}
-EXPORT_SYMBOL_GPL(__clk_get_parent);
-
-static struct clk_core *clk_core_get_parent_by_index(struct clk_core *clk,
-                                                        u8 index)
-{
-       if (!clk || index >= clk->num_parents)
-               return NULL;
-       else if (!clk->parents)
-               return clk_core_lookup(clk->parent_names[index]);
-       else if (!clk->parents[index])
-               return clk->parents[index] =
-                       clk_core_lookup(clk->parent_names[index]);
-       else
-               return clk->parents[index];
-}
-
-struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
-{
-       struct clk_core *parent;
-
-       if (!clk)
-               return NULL;
-
-       parent = clk_core_get_parent_by_index(clk->core, index);
-
-       return !parent ? NULL : parent->hw->clk;
-}
-EXPORT_SYMBOL_GPL(clk_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 *clk)
+static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
 {
        unsigned long ret;
 
-       if (!clk) {
+       if (!core) {
                ret = 0;
                goto out;
        }
 
-       ret = clk->rate;
+       ret = core->rate;
 
-       if (clk->flags & CLK_IS_ROOT)
+       if (core->flags & CLK_IS_ROOT)
                goto out;
 
-       if (!clk->parent)
+       if (!core->parent)
                ret = 0;
 
 out:
@@ -670,12 +396,12 @@ unsigned long __clk_get_rate(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(__clk_get_rate);
 
-static unsigned long __clk_get_accuracy(struct clk_core *clk)
+static unsigned long __clk_get_accuracy(struct clk_core *core)
 {
-       if (!clk)
+       if (!core)
                return 0;
 
-       return clk->accuracy;
+       return core->accuracy;
 }
 
 unsigned long __clk_get_flags(struct clk *clk)
@@ -684,27 +410,6 @@ unsigned long __clk_get_flags(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(__clk_get_flags);
 
-static bool clk_core_is_prepared(struct clk_core *clk)
-{
-       int ret;
-
-       if (!clk)
-               return false;
-
-       /*
-        * .is_prepared is optional for clocks that can prepare
-        * fall back to software usage counter if it is missing
-        */
-       if (!clk->ops->is_prepared) {
-               ret = clk->prepare_count ? 1 : 0;
-               goto out;
-       }
-
-       ret = clk->ops->is_prepared(clk->hw);
-out:
-       return !!ret;
-}
-
 bool __clk_is_prepared(struct clk *clk)
 {
        if (!clk)
@@ -713,27 +418,6 @@ bool __clk_is_prepared(struct clk *clk)
        return clk_core_is_prepared(clk->core);
 }
 
-static bool clk_core_is_enabled(struct clk_core *clk)
-{
-       int ret;
-
-       if (!clk)
-               return false;
-
-       /*
-        * .is_enabled is only mandatory for clocks that gate
-        * fall back to software usage counter if .is_enabled is missing
-        */
-       if (!clk->ops->is_enabled) {
-               ret = clk->enable_count ? 1 : 0;
-               goto out;
-       }
-
-       ret = clk->ops->is_enabled(clk->hw);
-out:
-       return !!ret;
-}
-
 bool __clk_is_enabled(struct clk *clk)
 {
        if (!clk)
@@ -743,49 +427,6 @@ bool __clk_is_enabled(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(__clk_is_enabled);
 
-static struct clk_core *__clk_lookup_subtree(const char *name,
-                                            struct clk_core *clk)
-{
-       struct clk_core *child;
-       struct clk_core *ret;
-
-       if (!strcmp(clk->name, name))
-               return clk;
-
-       hlist_for_each_entry(child, &clk->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;
-}
-
 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
                           unsigned long best, unsigned long flags)
 {
@@ -853,7 +494,7 @@ struct clk *__clk_lookup(const char *name)
        return !core ? NULL : core->hw->clk;
 }
 
-static void clk_core_get_boundaries(struct clk_core *clk,
+static void clk_core_get_boundaries(struct clk_core *core,
                                    unsigned long *min_rate,
                                    unsigned long *max_rate)
 {
@@ -862,10 +503,10 @@ static void clk_core_get_boundaries(struct clk_core *clk,
        *min_rate = 0;
        *max_rate = ULONG_MAX;
 
-       hlist_for_each_entry(clk_user, &clk->clks, clks_node)
+       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, &clk->clks, clks_node)
+       hlist_for_each_entry(clk_user, &core->clks, clks_node)
                *max_rate = min(*max_rate, clk_user->max_rate);
 }
 
@@ -901,26 +542,28 @@ EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
 
 /***        clk api        ***/
 
-static void clk_core_unprepare(struct clk_core *clk)
+static void clk_core_unprepare(struct clk_core *core)
 {
-       if (!clk)
+       lockdep_assert_held(&prepare_lock);
+
+       if (!core)
                return;
 
-       if (WARN_ON(clk->prepare_count == 0))
+       if (WARN_ON(core->prepare_count == 0))
                return;
 
-       if (--clk->prepare_count > 0)
+       if (--core->prepare_count > 0)
                return;
 
-       WARN_ON(clk->enable_count > 0);
+       WARN_ON(core->enable_count > 0);
 
-       trace_clk_unprepare(clk);
+       trace_clk_unprepare(core);
 
-       if (clk->ops->unprepare)
-               clk->ops->unprepare(clk->hw);
+       if (core->ops->unprepare)
+               core->ops->unprepare(core->hw);
 
-       trace_clk_unprepare_complete(clk);
-       clk_core_unprepare(clk->parent);
+       trace_clk_unprepare_complete(core);
+       clk_core_unprepare(core->parent);
 }
 
 /**
@@ -945,32 +588,34 @@ void clk_unprepare(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(clk_unprepare);
 
-static int clk_core_prepare(struct clk_core *clk)
+static int clk_core_prepare(struct clk_core *core)
 {
        int ret = 0;
 
-       if (!clk)
-               return 0;
+       lockdep_assert_held(&prepare_lock);
+
+       if (!core)
+               return 0;
 
-       if (clk->prepare_count == 0) {
-               ret = clk_core_prepare(clk->parent);
+       if (core->prepare_count == 0) {
+               ret = clk_core_prepare(core->parent);
                if (ret)
                        return ret;
 
-               trace_clk_prepare(clk);
+               trace_clk_prepare(core);
 
-               if (clk->ops->prepare)
-                       ret = clk->ops->prepare(clk->hw);
+               if (core->ops->prepare)
+                       ret = core->ops->prepare(core->hw);
 
-               trace_clk_prepare_complete(clk);
+               trace_clk_prepare_complete(core);
 
                if (ret) {
-                       clk_core_unprepare(clk->parent);
+                       clk_core_unprepare(core->parent);
                        return ret;
                }
        }
 
-       clk->prepare_count++;
+       core->prepare_count++;
 
        return 0;
 }
@@ -1002,33 +647,27 @@ int clk_prepare(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(clk_prepare);
 
-static void clk_core_disable(struct clk_core *clk)
+static void clk_core_disable(struct clk_core *core)
 {
-       if (!clk)
-               return;
+       lockdep_assert_held(&enable_lock);
 
-       if (WARN_ON(clk->enable_count == 0))
+       if (!core)
                return;
 
-       if (--clk->enable_count > 0)
+       if (WARN_ON(core->enable_count == 0))
                return;
 
-       trace_clk_disable(clk);
-
-       if (clk->ops->disable)
-               clk->ops->disable(clk->hw);
+       if (--core->enable_count > 0)
+               return;
 
-       trace_clk_disable_complete(clk);
+       trace_clk_disable(core);
 
-       clk_core_disable(clk->parent);
-}
+       if (core->ops->disable)
+               core->ops->disable(core->hw);
 
-static void __clk_disable(struct clk *clk)
-{
-       if (!clk)
-               return;
+       trace_clk_disable_complete(core);
 
-       clk_core_disable(clk->core);
+       clk_core_disable(core->parent);
 }
 
 /**
@@ -1051,52 +690,46 @@ void clk_disable(struct clk *clk)
                return;
 
        flags = clk_enable_lock();
-       __clk_disable(clk);
+       clk_core_disable(clk->core);
        clk_enable_unlock(flags);
 }
 EXPORT_SYMBOL_GPL(clk_disable);
 
-static int clk_core_enable(struct clk_core *clk)
+static int clk_core_enable(struct clk_core *core)
 {
        int ret = 0;
 
-       if (!clk)
+       lockdep_assert_held(&enable_lock);
+
+       if (!core)
                return 0;
 
-       if (WARN_ON(clk->prepare_count == 0))
+       if (WARN_ON(core->prepare_count == 0))
                return -ESHUTDOWN;
 
-       if (clk->enable_count == 0) {
-               ret = clk_core_enable(clk->parent);
+       if (core->enable_count == 0) {
+               ret = clk_core_enable(core->parent);
 
                if (ret)
                        return ret;
 
-               trace_clk_enable(clk);
+               trace_clk_enable(core);
 
-               if (clk->ops->enable)
-                       ret = clk->ops->enable(clk->hw);
+               if (core->ops->enable)
+                       ret = core->ops->enable(core->hw);
 
-               trace_clk_enable_complete(clk);
+               trace_clk_enable_complete(core);
 
                if (ret) {
-                       clk_core_disable(clk->parent);
+                       clk_core_disable(core->parent);
                        return ret;
                }
        }
 
-       clk->enable_count++;
+       core->enable_count++;
        return 0;
 }
 
-static int __clk_enable(struct clk *clk)
-{
-       if (!clk)
-               return 0;
-
-       return clk_core_enable(clk->core);
-}
-
 /**
  * clk_enable - ungate a clock
  * @clk: the clk being ungated
@@ -1115,15 +748,18 @@ int clk_enable(struct clk *clk)
        unsigned long flags;
        int ret;
 
+       if (!clk)
+               return 0;
+
        flags = clk_enable_lock();
-       ret = __clk_enable(clk);
+       ret = clk_core_enable(clk->core);
        clk_enable_unlock(flags);
 
        return ret;
 }
 EXPORT_SYMBOL_GPL(clk_enable);
 
-static unsigned long clk_core_round_rate_nolock(struct clk_core *clk,
+static unsigned long clk_core_round_rate_nolock(struct clk_core *core,
                                                unsigned long rate,
                                                unsigned long min_rate,
                                                unsigned long max_rate)
@@ -1134,25 +770,25 @@ static unsigned long clk_core_round_rate_nolock(struct clk_core *clk,
 
        lockdep_assert_held(&prepare_lock);
 
-       if (!clk)
+       if (!core)
                return 0;
 
-       parent = clk->parent;
+       parent = core->parent;
        if (parent)
                parent_rate = parent->rate;
 
-       if (clk->ops->determine_rate) {
+       if (core->ops->determine_rate) {
                parent_hw = parent ? parent->hw : NULL;
-               return clk->ops->determine_rate(clk->hw, rate,
+               return core->ops->determine_rate(core->hw, rate,
                                                min_rate, max_rate,
                                                &parent_rate, &parent_hw);
-       } else if (clk->ops->round_rate)
-               return clk->ops->round_rate(clk->hw, rate, &parent_rate);
-       else if (clk->flags & CLK_SET_RATE_PARENT)
-               return clk_core_round_rate_nolock(clk->parent, rate, min_rate,
+       } else if (core->ops->round_rate)
+               return core->ops->round_rate(core->hw, rate, &parent_rate);
+       else if (core->flags & CLK_SET_RATE_PARENT)
+               return clk_core_round_rate_nolock(core->parent, rate, min_rate,
                                                  max_rate);
        else
-               return clk->rate;
+               return core->rate;
 }
 
 /**
@@ -1162,8 +798,7 @@ static unsigned long clk_core_round_rate_nolock(struct clk_core *clk,
  * @min_rate: returned rate must be greater than this rate
  * @max_rate: returned rate must be less than this rate
  *
- * Caller must hold prepare_lock.  Useful for clk_ops such as .set_rate and
- * .determine_rate.
+ * Useful for clk_ops such as .set_rate and .determine_rate.
  */
 unsigned long __clk_determine_rate(struct clk_hw *hw,
                                   unsigned long rate,
@@ -1182,7 +817,7 @@ EXPORT_SYMBOL_GPL(__clk_determine_rate);
  * @clk: round the rate of this clock
  * @rate: the rate which is to be rounded
  *
- * Caller must hold prepare_lock.  Useful for clk_ops such as .set_rate
+ * Useful for clk_ops such as .set_rate
  */
 unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
 {
@@ -1224,7 +859,7 @@ EXPORT_SYMBOL_GPL(clk_round_rate);
 
 /**
  * __clk_notify - call clk notifier chain
- * @clk: struct clk * that is changing rate
+ * @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
@@ -1236,7 +871,7 @@ EXPORT_SYMBOL_GPL(clk_round_rate);
  * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
  * a driver returns that.
  */
-static int __clk_notify(struct clk_core *clk, unsigned long msg,
+static int __clk_notify(struct clk_core *core, unsigned long msg,
                unsigned long old_rate, unsigned long new_rate)
 {
        struct clk_notifier *cn;
@@ -1247,7 +882,7 @@ static int __clk_notify(struct clk_core *clk, unsigned long msg,
        cnd.new_rate = new_rate;
 
        list_for_each_entry(cn, &clk_notifier_list, node) {
-               if (cn->clk->core == clk) {
+               if (cn->clk->core == core) {
                        cnd.clk = cn->clk;
                        ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
                                        &cnd);
@@ -1259,44 +894,42 @@ static int __clk_notify(struct clk_core *clk, unsigned long msg,
 
 /**
  * __clk_recalc_accuracies
- * @clk: first clk in the subtree
+ * @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 it's
+ * callback then it is assumed that the clock will take on the accuracy of its
  * parent.
- *
- * Caller must hold prepare_lock.
  */
-static void __clk_recalc_accuracies(struct clk_core *clk)
+static void __clk_recalc_accuracies(struct clk_core *core)
 {
        unsigned long parent_accuracy = 0;
        struct clk_core *child;
 
        lockdep_assert_held(&prepare_lock);
 
-       if (clk->parent)
-               parent_accuracy = clk->parent->accuracy;
+       if (core->parent)
+               parent_accuracy = core->parent->accuracy;
 
-       if (clk->ops->recalc_accuracy)
-               clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
+       if (core->ops->recalc_accuracy)
+               core->accuracy = core->ops->recalc_accuracy(core->hw,
                                                          parent_accuracy);
        else
-               clk->accuracy = parent_accuracy;
+               core->accuracy = parent_accuracy;
 
-       hlist_for_each_entry(child, &clk->children, child_node)
+       hlist_for_each_entry(child, &core->children, child_node)
                __clk_recalc_accuracies(child);
 }
 
-static long clk_core_get_accuracy(struct clk_core *clk)
+static long clk_core_get_accuracy(struct clk_core *core)
 {
        unsigned long accuracy;
 
        clk_prepare_lock();
-       if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE))
-               __clk_recalc_accuracies(clk);
+       if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
+               __clk_recalc_accuracies(core);
 
-       accuracy = __clk_get_accuracy(clk);
+       accuracy = __clk_get_accuracy(core);
        clk_prepare_unlock();
 
        return accuracy;
@@ -1320,17 +953,17 @@ long clk_get_accuracy(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(clk_get_accuracy);
 
-static unsigned long clk_recalc(struct clk_core *clk,
+static unsigned long clk_recalc(struct clk_core *core,
                                unsigned long parent_rate)
 {
-       if (clk->ops->recalc_rate)
-               return clk->ops->recalc_rate(clk->hw, parent_rate);
+       if (core->ops->recalc_rate)
+               return core->ops->recalc_rate(core->hw, parent_rate);
        return parent_rate;
 }
 
 /**
  * __clk_recalc_rates
- * @clk: first clk in the subtree
+ * @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
@@ -1339,10 +972,8 @@ static unsigned long clk_recalc(struct clk_core *clk,
  *
  * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
  * if necessary.
- *
- * Caller must hold prepare_lock.
  */
-static void __clk_recalc_rates(struct clk_core *clk, unsigned long msg)
+static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
 {
        unsigned long old_rate;
        unsigned long parent_rate = 0;
@@ -1350,34 +981,34 @@ static void __clk_recalc_rates(struct clk_core *clk, unsigned long msg)
 
        lockdep_assert_held(&prepare_lock);
 
-       old_rate = clk->rate;
+       old_rate = core->rate;
 
-       if (clk->parent)
-               parent_rate = clk->parent->rate;
+       if (core->parent)
+               parent_rate = core->parent->rate;
 
-       clk->rate = clk_recalc(clk, 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 (clk->notifier_count && msg)
-               __clk_notify(clk, msg, old_rate, clk->rate);
+       if (core->notifier_count && msg)
+               __clk_notify(core, msg, old_rate, core->rate);
 
-       hlist_for_each_entry(child, &clk->children, child_node)
+       hlist_for_each_entry(child, &core->children, child_node)
                __clk_recalc_rates(child, msg);
 }
 
-static unsigned long clk_core_get_rate(struct clk_core *clk)
+static unsigned long clk_core_get_rate(struct clk_core *core)
 {
        unsigned long rate;
 
        clk_prepare_lock();
 
-       if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
-               __clk_recalc_rates(clk, 0);
+       if (core && (core->flags & CLK_GET_RATE_NOCACHE))
+               __clk_recalc_rates(core, 0);
 
-       rate = clk_core_get_rate_nolock(clk);
+       rate = clk_core_get_rate_nolock(core);
        clk_prepare_unlock();
 
        return rate;
@@ -1400,15 +1031,15 @@ unsigned long clk_get_rate(struct clk *clk)
 }
 EXPORT_SYMBOL_GPL(clk_get_rate);
 
-static int clk_fetch_parent_index(struct clk_core *clk,
+static int clk_fetch_parent_index(struct clk_core *core,
                                  struct clk_core *parent)
 {
        int i;
 
-       if (!clk->parents) {
-               clk->parents = kcalloc(clk->num_parents,
+       if (!core->parents) {
+               core->parents = kcalloc(core->num_parents,
                                        sizeof(struct clk *), GFP_KERNEL);
-               if (!clk->parents)
+               if (!core->parents)
                        return -ENOMEM;
        }
 
@@ -1417,15 +1048,15 @@ static int clk_fetch_parent_index(struct clk_core *clk,
         * or if not yet cached, use string name comparison and cache
         * them now to avoid future calls to clk_core_lookup.
         */
-       for (i = 0; i < clk->num_parents; i++) {
-               if (clk->parents[i] == parent)
+       for (i = 0; i < core->num_parents; i++) {
+               if (core->parents[i] == parent)
                        return i;
 
-               if (clk->parents[i])
+               if (core->parents[i])
                        continue;
 
-               if (!strcmp(clk->parent_names[i], parent->name)) {
-                       clk->parents[i] = clk_core_lookup(parent->name);
+               if (!strcmp(core->parent_names[i], parent->name)) {
+                       core->parents[i] = clk_core_lookup(parent->name);
                        return i;
                }
        }
@@ -1433,28 +1064,28 @@ static int clk_fetch_parent_index(struct clk_core *clk,
        return -EINVAL;
 }
 
-static void clk_reparent(struct clk_core *clk, struct clk_core *new_parent)
+static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
 {
-       hlist_del(&clk->child_node);
+       hlist_del(&core->child_node);
 
        if (new_parent) {
                /* avoid duplicate POST_RATE_CHANGE notifications */
-               if (new_parent->new_child == clk)
+               if (new_parent->new_child == core)
                        new_parent->new_child = NULL;
 
-               hlist_add_head(&clk->child_node, &new_parent->children);
+               hlist_add_head(&core->child_node, &new_parent->children);
        } else {
-               hlist_add_head(&clk->child_node, &clk_orphan_list);
+               hlist_add_head(&core->child_node, &clk_orphan_list);
        }
 
-       clk->parent = new_parent;
+       core->parent = new_parent;
 }
 
-static struct clk_core *__clk_set_parent_before(struct clk_core *clk,
+static struct clk_core *__clk_set_parent_before(struct clk_core *core,
                                           struct clk_core *parent)
 {
        unsigned long flags;
-       struct clk_core *old_parent = clk->parent;
+       struct clk_core *old_parent = core->parent;
 
        /*
         * Migrate prepare state between parents and prevent race with
@@ -1473,17 +1104,17 @@ static struct clk_core *__clk_set_parent_before(struct clk_core *clk,
         *
         * See also: Comment for clk_set_parent() below.
         */
-       if (clk->prepare_count) {
+       if (core->prepare_count) {
                clk_core_prepare(parent);
                flags = clk_enable_lock();
                clk_core_enable(parent);
-               clk_core_enable(clk);
+               clk_core_enable(core);
                clk_enable_unlock(flags);
        }
 
        /* update the clk tree topology */
        flags = clk_enable_lock();
-       clk_reparent(clk, parent);
+       clk_reparent(core, parent);
        clk_enable_unlock(flags);
 
        return old_parent;
@@ -1508,31 +1139,31 @@ static void __clk_set_parent_after(struct clk_core *core,
        }
 }
 
-static int __clk_set_parent(struct clk_core *clk, struct clk_core *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(clk, parent);
+       old_parent = __clk_set_parent_before(core, parent);
 
-       trace_clk_set_parent(clk, parent);
+       trace_clk_set_parent(core, parent);
 
        /* change clock input source */
-       if (parent && clk->ops->set_parent)
-               ret = clk->ops->set_parent(clk->hw, p_index);
+       if (parent && core->ops->set_parent)
+               ret = core->ops->set_parent(core->hw, p_index);
 
-       trace_clk_set_parent_complete(clk, parent);
+       trace_clk_set_parent_complete(core, parent);
 
        if (ret) {
                flags = clk_enable_lock();
-               clk_reparent(clk, old_parent);
+               clk_reparent(core, old_parent);
                clk_enable_unlock(flags);
 
-               if (clk->prepare_count) {
+               if (core->prepare_count) {
                        flags = clk_enable_lock();
-                       clk_core_disable(clk);
+                       clk_core_disable(core);
                        clk_core_disable(parent);
                        clk_enable_unlock(flags);
                        clk_core_unprepare(parent);
@@ -1540,14 +1171,14 @@ static int __clk_set_parent(struct clk_core *clk, struct clk_core *parent,
                return ret;
        }
 
-       __clk_set_parent_after(clk, parent, old_parent);
+       __clk_set_parent_after(core, parent, old_parent);
 
        return 0;
 }
 
 /**
  * __clk_speculate_rates
- * @clk: first clk in the subtree
+ * @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
@@ -1558,10 +1189,8 @@ static int __clk_set_parent(struct clk_core *clk, struct clk_core *parent,
  * 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.
- *
- * Caller must hold prepare_lock.
  */
-static int __clk_speculate_rates(struct clk_core *clk,
+static int __clk_speculate_rates(struct clk_core *core,
                                 unsigned long parent_rate)
 {
        struct clk_core *child;
@@ -1570,19 +1199,19 @@ static int __clk_speculate_rates(struct clk_core *clk,
 
        lockdep_assert_held(&prepare_lock);
 
-       new_rate = clk_recalc(clk, parent_rate);
+       new_rate = clk_recalc(core, parent_rate);
 
        /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
-       if (clk->notifier_count)
-               ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate);
+       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__, clk->name, ret);
+                               __func__, core->name, ret);
                goto out;
        }
 
-       hlist_for_each_entry(child, &clk->children, child_node) {
+       hlist_for_each_entry(child, &core->children, child_node) {
                ret = __clk_speculate_rates(child, new_rate);
                if (ret & NOTIFY_STOP_MASK)
                        break;
@@ -1592,20 +1221,20 @@ out:
        return ret;
 }
 
-static void clk_calc_subtree(struct clk_core *clk, unsigned long new_rate,
+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;
 
-       clk->new_rate = new_rate;
-       clk->new_parent = new_parent;
-       clk->new_parent_index = p_index;
+       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 */
-       clk->new_child = NULL;
-       if (new_parent && new_parent != clk->parent)
-               new_parent->new_child = clk;
+       core->new_child = NULL;
+       if (new_parent && new_parent != core->parent)
+               new_parent->new_child = core;
 
-       hlist_for_each_entry(child, &clk->children, child_node) {
+       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);
        }
@@ -1615,10 +1244,10 @@ static void clk_calc_subtree(struct clk_core *clk, unsigned long new_rate,
  * calculate the new rates returning the topmost clock that has to be
  * changed.
  */
-static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
+static struct clk_core *clk_calc_new_rates(struct clk_core *core,
                                           unsigned long rate)
 {
-       struct clk_core *top = clk;
+       struct clk_core *top = core;
        struct clk_core *old_parent, *parent;
        struct clk_hw *parent_hw;
        unsigned long best_parent_rate = 0;
@@ -1629,20 +1258,20 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
        long ret;
 
        /* sanity */
-       if (IS_ERR_OR_NULL(clk))
+       if (IS_ERR_OR_NULL(core))
                return NULL;
 
        /* save parent rate, if it exists */
-       parent = old_parent = clk->parent;
+       parent = old_parent = core->parent;
        if (parent)
                best_parent_rate = parent->rate;
 
-       clk_core_get_boundaries(clk, &min_rate, &max_rate);
+       clk_core_get_boundaries(core, &min_rate, &max_rate);
 
        /* find the closest rate and parent clk/rate */
-       if (clk->ops->determine_rate) {
+       if (core->ops->determine_rate) {
                parent_hw = parent ? parent->hw : NULL;
-               ret = clk->ops->determine_rate(clk->hw, rate,
+               ret = core->ops->determine_rate(core->hw, rate,
                                               min_rate,
                                               max_rate,
                                               &best_parent_rate,
@@ -1652,8 +1281,8 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
 
                new_rate = ret;
                parent = parent_hw ? parent_hw->core : NULL;
-       } else if (clk->ops->round_rate) {
-               ret = clk->ops->round_rate(clk->hw, rate,
+       } else if (core->ops->round_rate) {
+               ret = core->ops->round_rate(core->hw, rate,
                                           &best_parent_rate);
                if (ret < 0)
                        return NULL;
@@ -1661,9 +1290,9 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
                new_rate = ret;
                if (new_rate < min_rate || new_rate > max_rate)
                        return NULL;
-       } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) {
+       } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
                /* pass-through clock without adjustable parent */
-               clk->new_rate = clk->rate;
+               core->new_rate = core->rate;
                return NULL;
        } else {
                /* pass-through clock with adjustable parent */
@@ -1674,28 +1303,28 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
 
        /* some clocks must be gated to change parent */
        if (parent != old_parent &&
-           (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
+           (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
                pr_debug("%s: %s not gated but wants to reparent\n",
-                        __func__, clk->name);
+                        __func__, core->name);
                return NULL;
        }
 
        /* try finding the new parent index */
-       if (parent && clk->num_parents > 1) {
-               p_index = clk_fetch_parent_index(clk, parent);
+       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, clk->name);
+                                __func__, parent->name, core->name);
                        return NULL;
                }
        }
 
-       if ((clk->flags & CLK_SET_RATE_PARENT) && parent &&
+       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(clk, new_rate, parent, p_index);
+       clk_calc_subtree(core, new_rate, parent, p_index);
 
        return top;
 }
@@ -1705,33 +1334,33 @@ out:
  * 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 *clk,
+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 (clk->rate == clk->new_rate)
+       if (core->rate == core->new_rate)
                return NULL;
 
-       if (clk->notifier_count) {
-               ret = __clk_notify(clk, event, clk->rate, clk->new_rate);
+       if (core->notifier_count) {
+               ret = __clk_notify(core, event, core->rate, core->new_rate);
                if (ret & NOTIFY_STOP_MASK)
-                       fail_clk = clk;
+                       fail_clk = core;
        }
 
-       hlist_for_each_entry(child, &clk->children, child_node) {
+       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 != clk)
+               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 clk->children yet */
-       if (clk->new_child) {
-               tmp_clk = clk_propagate_rate_change(clk->new_child, event);
+       /* 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;
        }
@@ -1743,7 +1372,7 @@ static struct clk_core *clk_propagate_rate_change(struct clk_core *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 *clk)
+static void clk_change_rate(struct clk_core *core)
 {
        struct clk_core *child;
        struct hlist_node *tmp;
@@ -1752,80 +1381,80 @@ static void clk_change_rate(struct clk_core *clk)
        bool skip_set_rate = false;
        struct clk_core *old_parent;
 
-       old_rate = clk->rate;
+       old_rate = core->rate;
 
-       if (clk->new_parent)
-               best_parent_rate = clk->new_parent->rate;
-       else if (clk->parent)
-               best_parent_rate = clk->parent->rate;
+       if (core->new_parent)
+               best_parent_rate = core->new_parent->rate;
+       else if (core->parent)
+               best_parent_rate = core->parent->rate;
 
-       if (clk->new_parent && clk->new_parent != clk->parent) {
-               old_parent = __clk_set_parent_before(clk, clk->new_parent);
-               trace_clk_set_parent(clk, clk->new_parent);
+       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 (clk->ops->set_rate_and_parent) {
+               if (core->ops->set_rate_and_parent) {
                        skip_set_rate = true;
-                       clk->ops->set_rate_and_parent(clk->hw, clk->new_rate,
+                       core->ops->set_rate_and_parent(core->hw, core->new_rate,
                                        best_parent_rate,
-                                       clk->new_parent_index);
-               } else if (clk->ops->set_parent) {
-                       clk->ops->set_parent(clk->hw, clk->new_parent_index);
+                                       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(clk, clk->new_parent);
-               __clk_set_parent_after(clk, clk->new_parent, old_parent);
+               trace_clk_set_parent_complete(core, core->new_parent);
+               __clk_set_parent_after(core, core->new_parent, old_parent);
        }
 
-       trace_clk_set_rate(clk, clk->new_rate);
+       trace_clk_set_rate(core, core->new_rate);
 
-       if (!skip_set_rate && clk->ops->set_rate)
-               clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_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(clk, clk->new_rate);
+       trace_clk_set_rate_complete(core, core->new_rate);
 
-       clk->rate = clk_recalc(clk, best_parent_rate);
+       core->rate = clk_recalc(core, best_parent_rate);
 
-       if (clk->notifier_count && old_rate != clk->rate)
-               __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
+       if (core->notifier_count && old_rate != core->rate)
+               __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
 
-       if (clk->flags & CLK_RECALC_NEW_RATES)
-               (void)clk_calc_new_rates(clk, clk->new_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, &clk->children, child_node) {
+       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 != clk)
+               if (child->new_parent && child->new_parent != core)
                        continue;
                clk_change_rate(child);
        }
 
-       /* handle the new child who might not be in clk->children yet */
-       if (clk->new_child)
-               clk_change_rate(clk->new_child);
+       /* handle the new child who might not be in core->children yet */
+       if (core->new_child)
+               clk_change_rate(core->new_child);
 }
 
-static int clk_core_set_rate_nolock(struct clk_core *clk,
+static int clk_core_set_rate_nolock(struct clk_core *core,
                                    unsigned long req_rate)
 {
        struct clk_core *top, *fail_clk;
        unsigned long rate = req_rate;
        int ret = 0;
 
-       if (!clk)
+       if (!core)
                return 0;
 
        /* bail early if nothing to do */
-       if (rate == clk_core_get_rate_nolock(clk))
+       if (rate == clk_core_get_rate_nolock(core))
                return 0;
 
-       if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count)
+       if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
                return -EBUSY;
 
        /* calculate new rates and get the topmost changed clock */
-       top = clk_calc_new_rates(clk, rate);
+       top = clk_calc_new_rates(core, rate);
        if (!top)
                return -EINVAL;
 
@@ -1841,7 +1470,7 @@ static int clk_core_set_rate_nolock(struct clk_core *clk,
        /* change the rates */
        clk_change_rate(top);
 
-       clk->req_rate = req_rate;
+       core->req_rate = req_rate;
 
        return ret;
 }
@@ -1980,55 +1609,55 @@ EXPORT_SYMBOL_GPL(clk_get_parent);
  * .parents array exists, and if so use it to avoid an expensive tree
  * traversal.  If .parents does not exist then walk the tree.
  */
-static struct clk_core *__clk_init_parent(struct clk_core *clk)
+static struct clk_core *__clk_init_parent(struct clk_core *core)
 {
        struct clk_core *ret = NULL;
        u8 index;
 
        /* handle the trivial cases */
 
-       if (!clk->num_parents)
+       if (!core->num_parents)
                goto out;
 
-       if (clk->num_parents == 1) {
-               if (IS_ERR_OR_NULL(clk->parent))
-                       clk->parent = clk_core_lookup(clk->parent_names[0]);
-               ret = clk->parent;
+       if (core->num_parents == 1) {
+               if (IS_ERR_OR_NULL(core->parent))
+                       core->parent = clk_core_lookup(core->parent_names[0]);
+               ret = core->parent;
                goto out;
        }
 
-       if (!clk->ops->get_parent) {
-               WARN(!clk->ops->get_parent,
+       if (!core->ops->get_parent) {
+               WARN(!core->ops->get_parent,
                        "%s: multi-parent clocks must implement .get_parent\n",
                        __func__);
                goto out;
        };
 
        /*
-        * Do our best to cache parent clocks in clk->parents.  This prevents
-        * unnecessary and expensive lookups.  We don't set clk->parent here;
+        * Do our best to cache parent clocks in core->parents.  This prevents
+        * unnecessary and expensive lookups.  We don't set core->parent here;
         * that is done by the calling function.
         */
 
-       index = clk->ops->get_parent(clk->hw);
+       index = core->ops->get_parent(core->hw);
 
-       if (!clk->parents)
-               clk->parents =
-                       kcalloc(clk->num_parents, sizeof(struct clk *),
+       if (!core->parents)
+               core->parents =
+                       kcalloc(core->num_parents, sizeof(struct clk *),
                                        GFP_KERNEL);
 
-       ret = clk_core_get_parent_by_index(clk, index);
+       ret = clk_core_get_parent_by_index(core, index);
 
 out:
        return ret;
 }
 
-static void clk_core_reparent(struct clk_core *clk,
+static void clk_core_reparent(struct clk_core *core,
                                  struct clk_core *new_parent)
 {
-       clk_reparent(clk, new_parent);
-       __clk_recalc_accuracies(clk);
-       __clk_recalc_rates(clk, POST_RATE_CHANGE);
+       clk_reparent(core, new_parent);
+       __clk_recalc_accuracies(core);
+       __clk_recalc_rates(core, POST_RATE_CHANGE);
 }
 
 /**
@@ -2057,209 +1686,536 @@ bool clk_has_parent(struct clk *clk, struct clk *parent)
        if (core->parent == parent_core)
                return true;
 
-       for (i = 0; i < core->num_parents; i++)
-               if (strcmp(core->parent_names[i], parent_core->name) == 0)
-                       return true;
+       for (i = 0; i < core->num_parents; i++)
+               if (strcmp(core->parent_names[i], parent_core->name) == 0)
+                       return true;
+
+       return false;
+}
+EXPORT_SYMBOL_GPL(clk_has_parent);
+
+static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
+{
+       int ret = 0;
+       int p_index = 0;
+       unsigned long p_rate = 0;
+
+       if (!core)
+               return 0;
+
+       /* prevent racing with updates to the clock topology */
+       clk_prepare_lock();
+
+       if (core->parent == parent)
+               goto out;
+
+       /* verify ops for for multi-parent clks */
+       if ((core->num_parents > 1) && (!core->ops->set_parent)) {
+               ret = -ENOSYS;
+               goto out;
+       }
+
+       /* check that we are allowed to re-parent if the clock is in use */
+       if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
+               ret = -EBUSY;
+               goto out;
+       }
+
+       /* try finding the new parent index */
+       if (parent) {
+               p_index = clk_fetch_parent_index(core, parent);
+               p_rate = parent->rate;
+               if (p_index < 0) {
+                       pr_debug("%s: clk %s can not be parent of clk %s\n",
+                                       __func__, parent->name, core->name);
+                       ret = p_index;
+                       goto out;
+               }
+       }
+
+       /* propagate PRE_RATE_CHANGE notifications */
+       ret = __clk_speculate_rates(core, p_rate);
+
+       /* abort if a driver objects */
+       if (ret & NOTIFY_STOP_MASK)
+               goto out;
+
+       /* 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);
+       }
+
+out:
+       clk_prepare_unlock();
+
+       return ret;
+}
+
+/**
+ * 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)
+{
+       if (!clk)
+               return 0;
+
+       return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
+}
+EXPORT_SYMBOL_GPL(clk_set_parent);
+
+/**
+ * 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 = -EINVAL;
+
+       if (!clk)
+               return 0;
+
+       /* sanity check degrees */
+       degrees %= 360;
+       if (degrees < 0)
+               degrees += 360;
+
+       clk_prepare_lock();
+
+       trace_clk_set_phase(clk->core, degrees);
+
+       if (clk->core->ops->set_phase)
+               ret = clk->core->ops->set_phase(clk->core->hw, degrees);
+
+       trace_clk_set_phase_complete(clk->core, degrees);
+
+       if (!ret)
+               clk->core->phase = degrees;
+
+       clk_prepare_unlock();
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(clk_set_phase);
+
+static int clk_core_get_phase(struct clk_core *core)
+{
+       int ret;
+
+       clk_prepare_lock();
+       ret = core->phase;
+       clk_prepare_unlock();
+
+       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)
+{
+       if (!clk)
+               return 0;
+
+       return clk_core_get_phase(clk->core);
+}
+EXPORT_SYMBOL_GPL(clk_get_phase);
+
+/**
+ * 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 derefing 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 *all_lists[] = {
+       &clk_root_list,
+       &clk_orphan_list,
+       NULL,
+};
+
+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)
+{
+       if (!c)
+               return;
+
+       seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
+                  level * 3 + 1, "",
+                  30 - level * 3, c->name,
+                  c->enable_count, c->prepare_count, clk_core_get_rate(c),
+                  clk_core_get_accuracy(c), clk_core_get_phase(c));
+}
+
+static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
+                                    int level)
+{
+       struct clk_core *child;
+
+       if (!c)
+               return;
+
+       clk_summary_show_one(s, c, level);
+
+       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, "   clock                         enable_cnt  prepare_cnt        rate   accuracy   phase\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;
+}
+
+
+static int clk_summary_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, clk_summary_show, inode->i_private);
+}
+
+static const struct file_operations clk_summary_fops = {
+       .open           = clk_summary_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
+
+static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
+{
+       if (!c)
+               return;
+
+       /* 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, "\"rate\": %lu,", clk_core_get_rate(c));
+       seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
+       seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
+}
+
+static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
+{
+       struct clk_core *child;
+
+       if (!c)
+               return;
+
+       clk_dump_one(s, c, level);
+
+       hlist_for_each_entry(child, &c->children, child_node) {
+               seq_printf(s, ",");
+               clk_dump_subtree(s, child, level + 1);
+       }
+
+       seq_printf(s, "}");
+}
+
+static int clk_dump(struct seq_file *s, void *data)
+{
+       struct clk_core *c;
+       bool first_node = true;
+       struct hlist_head **lists = (struct hlist_head **)s->private;
+
+       seq_printf(s, "{");
+
+       clk_prepare_lock();
+
+       for (; *lists; lists++) {
+               hlist_for_each_entry(c, *lists, child_node) {
+                       if (!first_node)
+                               seq_puts(s, ",");
+                       first_node = false;
+                       clk_dump_subtree(s, c, 0);
+               }
+       }
+
+       clk_prepare_unlock();
 
-       return false;
+       seq_puts(s, "}\n");
+       return 0;
 }
-EXPORT_SYMBOL_GPL(clk_has_parent);
 
-static int clk_core_set_parent(struct clk_core *clk, struct clk_core *parent)
-{
-       int ret = 0;
-       int p_index = 0;
-       unsigned long p_rate = 0;
 
-       if (!clk)
-               return 0;
+static int clk_dump_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, clk_dump, inode->i_private);
+}
 
-       /* prevent racing with updates to the clock topology */
-       clk_prepare_lock();
+static const struct file_operations clk_dump_fops = {
+       .open           = clk_dump_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = single_release,
+};
 
-       if (clk->parent == parent)
-               goto out;
+static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
+{
+       struct dentry *d;
+       int ret = -ENOMEM;
 
-       /* verify ops for for multi-parent clks */
-       if ((clk->num_parents > 1) && (!clk->ops->set_parent)) {
-               ret = -ENOSYS;
+       if (!core || !pdentry) {
+               ret = -EINVAL;
                goto out;
        }
 
-       /* check that we are allowed to re-parent if the clock is in use */
-       if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
-               ret = -EBUSY;
+       d = debugfs_create_dir(core->name, pdentry);
+       if (!d)
                goto out;
-       }
 
-       /* try finding the new parent index */
-       if (parent) {
-               p_index = clk_fetch_parent_index(clk, parent);
-               p_rate = parent->rate;
-               if (p_index < 0) {
-                       pr_debug("%s: clk %s can not be parent of clk %s\n",
-                                       __func__, parent->name, clk->name);
-                       ret = p_index;
-                       goto out;
-               }
-       }
+       core->dentry = d;
 
-       /* propagate PRE_RATE_CHANGE notifications */
-       ret = __clk_speculate_rates(clk, p_rate);
+       d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
+                       (u32 *)&core->rate);
+       if (!d)
+               goto err_out;
 
-       /* abort if a driver objects */
-       if (ret & NOTIFY_STOP_MASK)
-               goto out;
+       d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
+                       (u32 *)&core->accuracy);
+       if (!d)
+               goto err_out;
 
-       /* do the re-parent */
-       ret = __clk_set_parent(clk, parent, p_index);
+       d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
+                       (u32 *)&core->phase);
+       if (!d)
+               goto err_out;
 
-       /* propagate rate an accuracy recalculation accordingly */
-       if (ret) {
-               __clk_recalc_rates(clk, ABORT_RATE_CHANGE);
-       } else {
-               __clk_recalc_rates(clk, POST_RATE_CHANGE);
-               __clk_recalc_accuracies(clk);
+       d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
+                       (u32 *)&core->flags);
+       if (!d)
+               goto err_out;
+
+       d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
+                       (u32 *)&core->prepare_count);
+       if (!d)
+               goto err_out;
+
+       d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
+                       (u32 *)&core->enable_count);
+       if (!d)
+               goto err_out;
+
+       d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
+                       (u32 *)&core->notifier_count);
+       if (!d)
+               goto err_out;
+
+       if (core->ops->debug_init) {
+               ret = core->ops->debug_init(core->hw, core->dentry);
+               if (ret)
+                       goto err_out;
        }
 
-out:
-       clk_prepare_unlock();
+       ret = 0;
+       goto out;
 
+err_out:
+       debugfs_remove_recursive(core->dentry);
+       core->dentry = NULL;
+out:
        return ret;
 }
 
 /**
- * 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.
+ * clk_debug_register - add a clk node to the debugfs clk directory
+ * @core: the clk being added to the debugfs clk directory
  *
- * Returns 0 on success, -EERROR otherwise.
+ * 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.
  */
-int clk_set_parent(struct clk *clk, struct clk *parent)
+static int clk_debug_register(struct clk_core *core)
 {
-       if (!clk)
-               return 0;
+       int ret = 0;
 
-       return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
+       mutex_lock(&clk_debug_lock);
+       hlist_add_head(&core->debug_node, &clk_debug_list);
+
+       if (!inited)
+               goto unlock;
+
+       ret = clk_debug_create_one(core, rootdir);
+unlock:
+       mutex_unlock(&clk_debug_lock);
+
+       return ret;
 }
-EXPORT_SYMBOL_GPL(clk_set_parent);
 
-/**
- * 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.
+ /**
+ * clk_debug_unregister - remove a clk node from the debugfs clk directory
+ * @core: the clk being removed from the debugfs clk directory
  *
- * 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.
+ * 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_init.
  */
-int clk_set_phase(struct clk *clk, int degrees)
+static void clk_debug_unregister(struct clk_core *core)
 {
-       int ret = -EINVAL;
+       mutex_lock(&clk_debug_lock);
+       hlist_del_init(&core->debug_node);
+       debugfs_remove_recursive(core->dentry);
+       core->dentry = NULL;
+       mutex_unlock(&clk_debug_lock);
+}
 
-       if (!clk)
-               return 0;
+struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
+                               void *data, const struct file_operations *fops)
+{
+       struct dentry *d = NULL;
 
-       /* sanity check degrees */
-       degrees %= 360;
-       if (degrees < 0)
-               degrees += 360;
+       if (hw->core->dentry)
+               d = debugfs_create_file(name, mode, hw->core->dentry, data,
+                                       fops);
 
-       clk_prepare_lock();
+       return d;
+}
+EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
 
-       trace_clk_set_phase(clk->core, degrees);
+/**
+ * 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;
+       struct dentry *d;
 
-       if (clk->core->ops->set_phase)
-               ret = clk->core->ops->set_phase(clk->core->hw, degrees);
+       rootdir = debugfs_create_dir("clk", NULL);
 
-       trace_clk_set_phase_complete(clk->core, degrees);
+       if (!rootdir)
+               return -ENOMEM;
 
-       if (!ret)
-               clk->core->phase = degrees;
+       d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
+                               &clk_summary_fops);
+       if (!d)
+               return -ENOMEM;
 
-       clk_prepare_unlock();
+       d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
+                               &clk_dump_fops);
+       if (!d)
+               return -ENOMEM;
 
-       return ret;
-}
-EXPORT_SYMBOL_GPL(clk_set_phase);
+       d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
+                               &orphan_list, &clk_summary_fops);
+       if (!d)
+               return -ENOMEM;
 
-static int clk_core_get_phase(struct clk_core *clk)
-{
-       int ret = 0;
+       d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
+                               &orphan_list, &clk_dump_fops);
+       if (!d)
+               return -ENOMEM;
 
-       if (!clk)
-               goto out;
+       mutex_lock(&clk_debug_lock);
+       hlist_for_each_entry(core, &clk_debug_list, debug_node)
+               clk_debug_create_one(core, rootdir);
 
-       clk_prepare_lock();
-       ret = clk->phase;
-       clk_prepare_unlock();
+       inited = 1;
+       mutex_unlock(&clk_debug_lock);
 
-out:
-       return ret;
+       return 0;
 }
-EXPORT_SYMBOL_GPL(clk_get_phase);
-
-/**
- * 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)
+late_initcall(clk_debug_init);
+#else
+static inline int clk_debug_register(struct clk_core *core) { return 0; }
+static inline void clk_debug_reparent(struct clk_core *core,
+                                     struct clk_core *new_parent)
 {
-       if (!clk)
-               return 0;
-
-       return clk_core_get_phase(clk->core);
 }
-
-/**
- * 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)
+static inline void clk_debug_unregister(struct clk_core *core)
 {
-       /* trivial case: identical struct clk's or both NULL */
-       if (p == q)
-               return true;
-
-       /* true if clk->core pointers match. Avoid derefing 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);
+#endif
 
 /**
  * __clk_init - initialize the data structures in a struct clk
@@ -2274,67 +2230,67 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
        int i, ret = 0;
        struct clk_core *orphan;
        struct hlist_node *tmp2;
-       struct clk_core *clk;
+       struct clk_core *core;
        unsigned long rate;
 
        if (!clk_user)
                return -EINVAL;
 
-       clk = clk_user->core;
+       core = clk_user->core;
 
        clk_prepare_lock();
 
        /* check to see if a clock with this name is already registered */
-       if (clk_core_lookup(clk->name)) {
+       if (clk_core_lookup(core->name)) {
                pr_debug("%s: clk %s already initialized\n",
-                               __func__, clk->name);
+                               __func__, core->name);
                ret = -EEXIST;
                goto out;
        }
 
        /* check that clk_ops are sane.  See Documentation/clk.txt */
-       if (clk->ops->set_rate &&
-           !((clk->ops->round_rate || clk->ops->determine_rate) &&
-             clk->ops->recalc_rate)) {
+       if (core->ops->set_rate &&
+           !((core->ops->round_rate || core->ops->determine_rate) &&
+             core->ops->recalc_rate)) {
                pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
-                               __func__, clk->name);
+                               __func__, core->name);
                ret = -EINVAL;
                goto out;
        }
 
-       if (clk->ops->set_parent && !clk->ops->get_parent) {
+       if (core->ops->set_parent && !core->ops->get_parent) {
                pr_warning("%s: %s must implement .get_parent & .set_parent\n",
-                               __func__, clk->name);
+                               __func__, core->name);
                ret = -EINVAL;
                goto out;
        }
 
-       if (clk->ops->set_rate_and_parent &&
-                       !(clk->ops->set_parent && clk->ops->set_rate)) {
+       if (core->ops->set_rate_and_parent &&
+                       !(core->ops->set_parent && core->ops->set_rate)) {
                pr_warn("%s: %s must implement .set_parent & .set_rate\n",
-                               __func__, clk->name);
+                               __func__, core->name);
                ret = -EINVAL;
                goto out;
        }
 
        /* throw a WARN if any entries in parent_names are NULL */
-       for (i = 0; i < clk->num_parents; i++)
-               WARN(!clk->parent_names[i],
+       for (i = 0; i < core->num_parents; i++)
+               WARN(!core->parent_names[i],
                                "%s: invalid NULL in %s's .parent_names\n",
-                               __func__, clk->name);
+                               __func__, core->name);
 
        /*
         * Allocate an array of struct clk *'s to avoid unnecessary string
         * look-ups of clk's possible parents.  This can fail for clocks passed
-        * in to clk_init during early boot; thus any access to clk->parents[]
+        * in to clk_init during early boot; thus any access to core->parents[]
         * must always check for a NULL pointer and try to populate it if
         * necessary.
         *
-        * If clk->parents is not NULL we skip this entire block.  This allows
-        * for clock drivers to statically initialize clk->parents.
+        * If core->parents is not NULL we skip this entire block.  This allows
+        * for clock drivers to statically initialize core->parents.
         */
-       if (clk->num_parents > 1 && !clk->parents) {
-               clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *),
+       if (core->num_parents > 1 && !core->parents) {
+               core->parents = kcalloc(core->num_parents, sizeof(struct clk *),
                                        GFP_KERNEL);
                /*
                 * clk_core_lookup returns NULL for parents that have not been
@@ -2342,16 +2298,16 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
                 * for a NULL pointer.  We can always perform lazy lookups for
                 * missing parents later on.
                 */
-               if (clk->parents)
-                       for (i = 0; i < clk->num_parents; i++)
-                               clk->parents[i] =
-                                       clk_core_lookup(clk->parent_names[i]);
+               if (core->parents)
+                       for (i = 0; i < core->num_parents; i++)
+                               core->parents[i] =
+                                       clk_core_lookup(core->parent_names[i]);
        }
 
-       clk->parent = __clk_init_parent(clk);
+       core->parent = __clk_init_parent(core);
 
        /*
-        * Populate clk->parent if parent has already been __clk_init'd.  If
+        * Populate core->parent if parent has already been __clk_init'd.  If
         * parent has not yet been __clk_init'd then place clk in the orphan
         * list.  If clk has set the CLK_IS_ROOT flag then place it in the root
         * clk list.
@@ -2360,13 +2316,13 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
         * clocks and re-parent any that are children of the clock currently
         * being clk_init'd.
         */
-       if (clk->parent)
-               hlist_add_head(&clk->child_node,
-                               &clk->parent->children);
-       else if (clk->flags & CLK_IS_ROOT)
-               hlist_add_head(&clk->child_node, &clk_root_list);
+       if (core->parent)
+               hlist_add_head(&core->child_node,
+                               &core->parent->children);
+       else if (core->flags & CLK_IS_ROOT)
+               hlist_add_head(&core->child_node, &clk_root_list);
        else
-               hlist_add_head(&clk->child_node, &clk_orphan_list);
+               hlist_add_head(&core->child_node, &clk_orphan_list);
 
        /*
         * Set clk's accuracy.  The preferred method is to use
@@ -2375,23 +2331,23 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
         * parent (or is orphaned) then accuracy is set to zero (perfect
         * clock).
         */
-       if (clk->ops->recalc_accuracy)
-               clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
-                                       __clk_get_accuracy(clk->parent));
-       else if (clk->parent)
-               clk->accuracy = clk->parent->accuracy;
+       if (core->ops->recalc_accuracy)
+               core->accuracy = core->ops->recalc_accuracy(core->hw,
+                                       __clk_get_accuracy(core->parent));
+       else if (core->parent)
+               core->accuracy = core->parent->accuracy;
        else
-               clk->accuracy = 0;
+               core->accuracy = 0;
 
        /*
         * Set clk's phase.
         * Since a phase is by definition relative to its parent, just
         * query the current clock phase, or just assume it's in phase.
         */
-       if (clk->ops->get_phase)
-               clk->phase = clk->ops->get_phase(clk->hw);
+       if (core->ops->get_phase)
+               core->phase = core->ops->get_phase(core->hw);
        else
-               clk->phase = 0;
+               core->phase = 0;
 
        /*
         * Set clk's rate.  The preferred method is to use .recalc_rate.  For
@@ -2399,14 +2355,14 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
         * parent's rate.  If a clock doesn't have a parent (or is orphaned)
         * then rate is set to zero.
         */
-       if (clk->ops->recalc_rate)
-               rate = clk->ops->recalc_rate(clk->hw,
-                               clk_core_get_rate_nolock(clk->parent));
-       else if (clk->parent)
-               rate = clk->parent->rate;
+       if (core->ops->recalc_rate)
+               rate = core->ops->recalc_rate(core->hw,
+                               clk_core_get_rate_nolock(core->parent));
+       else if (core->parent)
+               rate = core->parent->rate;
        else
                rate = 0;
-       clk->rate = clk->req_rate = rate;
+       core->rate = core->req_rate = rate;
 
        /*
         * walk the list of orphan clocks and reparent any that are children of
@@ -2415,14 +2371,14 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
        hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
                if (orphan->num_parents && orphan->ops->get_parent) {
                        i = orphan->ops->get_parent(orphan->hw);
-                       if (!strcmp(clk->name, orphan->parent_names[i]))
-                               clk_core_reparent(orphan, clk);
+                       if (!strcmp(core->name, orphan->parent_names[i]))
+                               clk_core_reparent(orphan, core);
                        continue;
                }
 
                for (i = 0; i < orphan->num_parents; i++)
-                       if (!strcmp(clk->name, orphan->parent_names[i])) {
-                               clk_core_reparent(orphan, clk);
+                       if (!strcmp(core->name, orphan->parent_names[i])) {
+                               clk_core_reparent(orphan, core);
                                break;
                        }
         }
@@ -2435,15 +2391,15 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
         * Please consider other ways of solving initialization problems before
         * using this callback, as its use is discouraged.
         */
-       if (clk->ops->init)
-               clk->ops->init(clk->hw);
+       if (core->ops->init)
+               core->ops->init(core->hw);
 
-       kref_init(&clk->ref);
+       kref_init(&core->ref);
 out:
        clk_prepare_unlock();
 
        if (!ret)
-               clk_debug_register(clk);
+               clk_debug_register(core);
 
        return ret;
 }
@@ -2489,63 +2445,58 @@ void __clk_free_clk(struct clk *clk)
  *
  * clk_register is the primary interface for populating the clock tree with new
  * clock nodes.  It returns a pointer to the newly allocated struct clk which
- * cannot be dereferenced by driver code but may be used in conjuction with the
+ * 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)
 {
        int i, ret;
-       struct clk_core *clk;
+       struct clk_core *core;
 
-       clk = kzalloc(sizeof(*clk), GFP_KERNEL);
-       if (!clk) {
-               pr_err("%s: could not allocate clk\n", __func__);
+       core = kzalloc(sizeof(*core), GFP_KERNEL);
+       if (!core) {
                ret = -ENOMEM;
                goto fail_out;
        }
 
-       clk->name = kstrdup_const(hw->init->name, GFP_KERNEL);
-       if (!clk->name) {
-               pr_err("%s: could not allocate clk->name\n", __func__);
+       core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
+       if (!core->name) {
                ret = -ENOMEM;
                goto fail_name;
        }
-       clk->ops = hw->init->ops;
+       core->ops = hw->init->ops;
        if (dev && dev->driver)
-               clk->owner = dev->driver->owner;
-       clk->hw = hw;
-       clk->flags = hw->init->flags;
-       clk->num_parents = hw->init->num_parents;
-       hw->core = clk;
+               core->owner = dev->driver->owner;
+       core->hw = hw;
+       core->flags = hw->init->flags;
+       core->num_parents = hw->init->num_parents;
+       hw->core = core;
 
        /* allocate local copy in case parent_names is __initdata */
-       clk->parent_names = kcalloc(clk->num_parents, sizeof(char *),
+       core->parent_names = kcalloc(core->num_parents, sizeof(char *),
                                        GFP_KERNEL);
 
-       if (!clk->parent_names) {
-               pr_err("%s: could not allocate clk->parent_names\n", __func__);
+       if (!core->parent_names) {
                ret = -ENOMEM;
                goto fail_parent_names;
        }
 
 
        /* copy each string name in case parent_names is __initdata */
-       for (i = 0; i < clk->num_parents; i++) {
-               clk->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
+       for (i = 0; i < core->num_parents; i++) {
+               core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
                                                GFP_KERNEL);
-               if (!clk->parent_names[i]) {
-                       pr_err("%s: could not copy parent_names\n", __func__);
+               if (!core->parent_names[i]) {
                        ret = -ENOMEM;
                        goto fail_parent_names_copy;
                }
        }
 
-       INIT_HLIST_HEAD(&clk->clks);
+       INIT_HLIST_HEAD(&core->clks);
 
        hw->clk = __clk_create_clk(hw, NULL, NULL);
        if (IS_ERR(hw->clk)) {
-               pr_err("%s: could not allocate per-user clk\n", __func__);
                ret = PTR_ERR(hw->clk);
                goto fail_parent_names_copy;
        }
@@ -2559,35 +2510,32 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
 
 fail_parent_names_copy:
        while (--i >= 0)
-               kfree_const(clk->parent_names[i]);
-       kfree(clk->parent_names);
+               kfree_const(core->parent_names[i]);
+       kfree(core->parent_names);
 fail_parent_names:
-       kfree_const(clk->name);
+       kfree_const(core->name);
 fail_name:
-       kfree(clk);
+       kfree(core);
 fail_out:
        return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(clk_register);
 
-/*
- * Free memory allocated for a clock.
- * Caller must hold prepare_lock.
- */
+/* Free memory allocated for a clock. */
 static void __clk_release(struct kref *ref)
 {
-       struct clk_core *clk = container_of(ref, struct clk_core, ref);
-       int i = clk->num_parents;
+       struct clk_core *core = container_of(ref, struct clk_core, ref);
+       int i = core->num_parents;
 
        lockdep_assert_held(&prepare_lock);
 
-       kfree(clk->parents);
+       kfree(core->parents);
        while (--i >= 0)
-               kfree_const(clk->parent_names[i]);
+               kfree_const(core->parent_names[i]);
 
-       kfree(clk->parent_names);
-       kfree_const(clk->name);
-       kfree(clk);
+       kfree(core->parent_names);
+       kfree_const(core->name);
+       kfree(core);
 }
 
 /*
@@ -3071,6 +3019,27 @@ const char *of_clk_get_parent_name(struct device_node *np, int index)
 }
 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 {
        of_clk_init_cb_t clk_init_cb;
        struct device_node *np;