2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Standard functionality for the common clock API. See Documentation/clk.txt
12 #include <linux/clk-provider.h>
13 #include <linux/clk/clk-conf.h>
14 #include <linux/module.h>
15 #include <linux/mutex.h>
16 #include <linux/spinlock.h>
17 #include <linux/err.h>
18 #include <linux/list.h>
19 #include <linux/slab.h>
21 #include <linux/device.h>
22 #include <linux/init.h>
23 #include <linux/sched.h>
27 static DEFINE_SPINLOCK(enable_lock);
28 static DEFINE_MUTEX(prepare_lock);
30 static struct task_struct *prepare_owner;
31 static struct task_struct *enable_owner;
33 static int prepare_refcnt;
34 static int enable_refcnt;
36 static HLIST_HEAD(clk_root_list);
37 static HLIST_HEAD(clk_orphan_list);
38 static LIST_HEAD(clk_notifier_list);
40 static long clk_core_get_accuracy(struct clk_core *clk);
41 static unsigned long clk_core_get_rate(struct clk_core *clk);
42 static int clk_core_get_phase(struct clk_core *clk);
43 static bool clk_core_is_prepared(struct clk_core *clk);
44 static bool clk_core_is_enabled(struct clk_core *clk);
45 static struct clk_core *clk_core_lookup(const char *name);
47 /*** private data structures ***/
51 const struct clk_ops *ops;
54 struct clk_core *parent;
55 const char **parent_names;
56 struct clk_core **parents;
60 unsigned long req_rate;
61 unsigned long new_rate;
62 struct clk_core *new_parent;
63 struct clk_core *new_child;
65 unsigned int enable_count;
66 unsigned int prepare_count;
67 unsigned long accuracy;
69 struct hlist_head children;
70 struct hlist_node child_node;
71 struct hlist_node debug_node;
72 struct hlist_head clks;
73 unsigned int notifier_count;
74 #ifdef CONFIG_DEBUG_FS
75 struct dentry *dentry;
80 #define CREATE_TRACE_POINTS
81 #include <trace/events/clk.h>
84 struct clk_core *core;
87 unsigned long min_rate;
88 unsigned long max_rate;
89 struct hlist_node clks_node;
93 static void clk_prepare_lock(void)
95 if (!mutex_trylock(&prepare_lock)) {
96 if (prepare_owner == current) {
100 mutex_lock(&prepare_lock);
102 WARN_ON_ONCE(prepare_owner != NULL);
103 WARN_ON_ONCE(prepare_refcnt != 0);
104 prepare_owner = current;
108 static void clk_prepare_unlock(void)
110 WARN_ON_ONCE(prepare_owner != current);
111 WARN_ON_ONCE(prepare_refcnt == 0);
113 if (--prepare_refcnt)
115 prepare_owner = NULL;
116 mutex_unlock(&prepare_lock);
119 static unsigned long clk_enable_lock(void)
123 if (!spin_trylock_irqsave(&enable_lock, flags)) {
124 if (enable_owner == current) {
128 spin_lock_irqsave(&enable_lock, flags);
130 WARN_ON_ONCE(enable_owner != NULL);
131 WARN_ON_ONCE(enable_refcnt != 0);
132 enable_owner = current;
137 static void clk_enable_unlock(unsigned long flags)
139 WARN_ON_ONCE(enable_owner != current);
140 WARN_ON_ONCE(enable_refcnt == 0);
145 spin_unlock_irqrestore(&enable_lock, flags);
148 /*** debugfs support ***/
150 #ifdef CONFIG_DEBUG_FS
151 #include <linux/debugfs.h>
153 static struct dentry *rootdir;
154 static int inited = 0;
155 static DEFINE_MUTEX(clk_debug_lock);
156 static HLIST_HEAD(clk_debug_list);
158 static struct hlist_head *all_lists[] = {
164 static struct hlist_head *orphan_list[] = {
169 static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
175 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
177 30 - level * 3, c->name,
178 c->enable_count, c->prepare_count, clk_core_get_rate(c),
179 clk_core_get_accuracy(c), clk_core_get_phase(c));
182 static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
185 struct clk_core *child;
190 clk_summary_show_one(s, c, level);
192 hlist_for_each_entry(child, &c->children, child_node)
193 clk_summary_show_subtree(s, child, level + 1);
196 static int clk_summary_show(struct seq_file *s, void *data)
199 struct hlist_head **lists = (struct hlist_head **)s->private;
201 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
202 seq_puts(s, "----------------------------------------------------------------------------------------\n");
206 for (; *lists; lists++)
207 hlist_for_each_entry(c, *lists, child_node)
208 clk_summary_show_subtree(s, c, 0);
210 clk_prepare_unlock();
216 static int clk_summary_open(struct inode *inode, struct file *file)
218 return single_open(file, clk_summary_show, inode->i_private);
221 static const struct file_operations clk_summary_fops = {
222 .open = clk_summary_open,
225 .release = single_release,
228 static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
233 /* This should be JSON format, i.e. elements separated with a comma */
234 seq_printf(s, "\"%s\": { ", c->name);
235 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
236 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
237 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
238 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
239 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
242 static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
244 struct clk_core *child;
249 clk_dump_one(s, c, level);
251 hlist_for_each_entry(child, &c->children, child_node) {
253 clk_dump_subtree(s, child, level + 1);
259 static int clk_dump(struct seq_file *s, void *data)
262 bool first_node = true;
263 struct hlist_head **lists = (struct hlist_head **)s->private;
269 for (; *lists; lists++) {
270 hlist_for_each_entry(c, *lists, child_node) {
274 clk_dump_subtree(s, c, 0);
278 clk_prepare_unlock();
285 static int clk_dump_open(struct inode *inode, struct file *file)
287 return single_open(file, clk_dump, inode->i_private);
290 static const struct file_operations clk_dump_fops = {
291 .open = clk_dump_open,
294 .release = single_release,
297 static int clk_debug_create_one(struct clk_core *clk, struct dentry *pdentry)
302 if (!clk || !pdentry) {
307 d = debugfs_create_dir(clk->name, pdentry);
313 d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry,
318 d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry,
319 (u32 *)&clk->accuracy);
323 d = debugfs_create_u32("clk_phase", S_IRUGO, clk->dentry,
328 d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry,
333 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry,
334 (u32 *)&clk->prepare_count);
338 d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry,
339 (u32 *)&clk->enable_count);
343 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry,
344 (u32 *)&clk->notifier_count);
348 if (clk->ops->debug_init) {
349 ret = clk->ops->debug_init(clk->hw, clk->dentry);
358 debugfs_remove_recursive(clk->dentry);
365 * clk_debug_register - add a clk node to the debugfs clk tree
366 * @clk: the clk being added to the debugfs clk tree
368 * Dynamically adds a clk to the debugfs clk tree if debugfs has been
369 * initialized. Otherwise it bails out early since the debugfs clk tree
370 * will be created lazily by clk_debug_init as part of a late_initcall.
372 static int clk_debug_register(struct clk_core *clk)
376 mutex_lock(&clk_debug_lock);
377 hlist_add_head(&clk->debug_node, &clk_debug_list);
382 ret = clk_debug_create_one(clk, rootdir);
384 mutex_unlock(&clk_debug_lock);
390 * clk_debug_unregister - remove a clk node from the debugfs clk tree
391 * @clk: the clk being removed from the debugfs clk tree
393 * Dynamically removes a clk and all it's children clk nodes from the
394 * debugfs clk tree if clk->dentry points to debugfs created by
395 * clk_debug_register in __clk_init.
397 static void clk_debug_unregister(struct clk_core *clk)
399 mutex_lock(&clk_debug_lock);
400 hlist_del_init(&clk->debug_node);
401 debugfs_remove_recursive(clk->dentry);
403 mutex_unlock(&clk_debug_lock);
406 struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
407 void *data, const struct file_operations *fops)
409 struct dentry *d = NULL;
411 if (hw->core->dentry)
412 d = debugfs_create_file(name, mode, hw->core->dentry, data,
417 EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
420 * clk_debug_init - lazily create the debugfs clk tree visualization
422 * clks are often initialized very early during boot before memory can
423 * be dynamically allocated and well before debugfs is setup.
424 * clk_debug_init walks the clk tree hierarchy while holding
425 * prepare_lock and creates the topology as part of a late_initcall,
426 * thus insuring that clks initialized very early will still be
427 * represented in the debugfs clk tree. This function should only be
428 * called once at boot-time, and all other clks added dynamically will
429 * be done so with clk_debug_register.
431 static int __init clk_debug_init(void)
433 struct clk_core *clk;
436 rootdir = debugfs_create_dir("clk", NULL);
441 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
446 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
451 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
452 &orphan_list, &clk_summary_fops);
456 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
457 &orphan_list, &clk_dump_fops);
461 mutex_lock(&clk_debug_lock);
462 hlist_for_each_entry(clk, &clk_debug_list, debug_node)
463 clk_debug_create_one(clk, rootdir);
466 mutex_unlock(&clk_debug_lock);
470 late_initcall(clk_debug_init);
472 static inline int clk_debug_register(struct clk_core *clk) { return 0; }
473 static inline void clk_debug_reparent(struct clk_core *clk,
474 struct clk_core *new_parent)
477 static inline void clk_debug_unregister(struct clk_core *clk)
482 /* caller must hold prepare_lock */
483 static void clk_unprepare_unused_subtree(struct clk_core *clk)
485 struct clk_core *child;
487 lockdep_assert_held(&prepare_lock);
489 hlist_for_each_entry(child, &clk->children, child_node)
490 clk_unprepare_unused_subtree(child);
492 if (clk->prepare_count)
495 if (clk->flags & CLK_IGNORE_UNUSED)
498 if (clk_core_is_prepared(clk)) {
499 trace_clk_unprepare(clk);
500 if (clk->ops->unprepare_unused)
501 clk->ops->unprepare_unused(clk->hw);
502 else if (clk->ops->unprepare)
503 clk->ops->unprepare(clk->hw);
504 trace_clk_unprepare_complete(clk);
508 /* caller must hold prepare_lock */
509 static void clk_disable_unused_subtree(struct clk_core *clk)
511 struct clk_core *child;
514 lockdep_assert_held(&prepare_lock);
516 hlist_for_each_entry(child, &clk->children, child_node)
517 clk_disable_unused_subtree(child);
519 flags = clk_enable_lock();
521 if (clk->enable_count)
524 if (clk->flags & CLK_IGNORE_UNUSED)
528 * some gate clocks have special needs during the disable-unused
529 * sequence. call .disable_unused if available, otherwise fall
532 if (clk_core_is_enabled(clk)) {
533 trace_clk_disable(clk);
534 if (clk->ops->disable_unused)
535 clk->ops->disable_unused(clk->hw);
536 else if (clk->ops->disable)
537 clk->ops->disable(clk->hw);
538 trace_clk_disable_complete(clk);
542 clk_enable_unlock(flags);
545 static bool clk_ignore_unused;
546 static int __init clk_ignore_unused_setup(char *__unused)
548 clk_ignore_unused = true;
551 __setup("clk_ignore_unused", clk_ignore_unused_setup);
553 static int clk_disable_unused(void)
555 struct clk_core *clk;
557 if (clk_ignore_unused) {
558 pr_warn("clk: Not disabling unused clocks\n");
564 hlist_for_each_entry(clk, &clk_root_list, child_node)
565 clk_disable_unused_subtree(clk);
567 hlist_for_each_entry(clk, &clk_orphan_list, child_node)
568 clk_disable_unused_subtree(clk);
570 hlist_for_each_entry(clk, &clk_root_list, child_node)
571 clk_unprepare_unused_subtree(clk);
573 hlist_for_each_entry(clk, &clk_orphan_list, child_node)
574 clk_unprepare_unused_subtree(clk);
576 clk_prepare_unlock();
580 late_initcall_sync(clk_disable_unused);
582 /*** helper functions ***/
584 const char *__clk_get_name(struct clk *clk)
586 return !clk ? NULL : clk->core->name;
588 EXPORT_SYMBOL_GPL(__clk_get_name);
590 struct clk_hw *__clk_get_hw(struct clk *clk)
592 return !clk ? NULL : clk->core->hw;
594 EXPORT_SYMBOL_GPL(__clk_get_hw);
596 u8 __clk_get_num_parents(struct clk *clk)
598 return !clk ? 0 : clk->core->num_parents;
600 EXPORT_SYMBOL_GPL(__clk_get_num_parents);
602 struct clk *__clk_get_parent(struct clk *clk)
607 /* TODO: Create a per-user clk and change callers to call clk_put */
608 return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
610 EXPORT_SYMBOL_GPL(__clk_get_parent);
612 static struct clk_core *clk_core_get_parent_by_index(struct clk_core *clk,
615 if (!clk || index >= clk->num_parents)
617 else if (!clk->parents)
618 return clk_core_lookup(clk->parent_names[index]);
619 else if (!clk->parents[index])
620 return clk->parents[index] =
621 clk_core_lookup(clk->parent_names[index]);
623 return clk->parents[index];
626 struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
628 struct clk_core *parent;
633 parent = clk_core_get_parent_by_index(clk->core, index);
635 return !parent ? NULL : parent->hw->clk;
637 EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
639 unsigned int __clk_get_enable_count(struct clk *clk)
641 return !clk ? 0 : clk->core->enable_count;
644 static unsigned long clk_core_get_rate_nolock(struct clk_core *clk)
655 if (clk->flags & CLK_IS_ROOT)
665 unsigned long __clk_get_rate(struct clk *clk)
670 return clk_core_get_rate_nolock(clk->core);
672 EXPORT_SYMBOL_GPL(__clk_get_rate);
674 static unsigned long __clk_get_accuracy(struct clk_core *clk)
679 return clk->accuracy;
682 unsigned long __clk_get_flags(struct clk *clk)
684 return !clk ? 0 : clk->core->flags;
686 EXPORT_SYMBOL_GPL(__clk_get_flags);
688 static bool clk_core_is_prepared(struct clk_core *clk)
696 * .is_prepared is optional for clocks that can prepare
697 * fall back to software usage counter if it is missing
699 if (!clk->ops->is_prepared) {
700 ret = clk->prepare_count ? 1 : 0;
704 ret = clk->ops->is_prepared(clk->hw);
709 bool __clk_is_prepared(struct clk *clk)
714 return clk_core_is_prepared(clk->core);
717 static bool clk_core_is_enabled(struct clk_core *clk)
725 * .is_enabled is only mandatory for clocks that gate
726 * fall back to software usage counter if .is_enabled is missing
728 if (!clk->ops->is_enabled) {
729 ret = clk->enable_count ? 1 : 0;
733 ret = clk->ops->is_enabled(clk->hw);
738 bool __clk_is_enabled(struct clk *clk)
743 return clk_core_is_enabled(clk->core);
745 EXPORT_SYMBOL_GPL(__clk_is_enabled);
747 static struct clk_core *__clk_lookup_subtree(const char *name,
748 struct clk_core *clk)
750 struct clk_core *child;
751 struct clk_core *ret;
753 if (!strcmp(clk->name, name))
756 hlist_for_each_entry(child, &clk->children, child_node) {
757 ret = __clk_lookup_subtree(name, child);
765 static struct clk_core *clk_core_lookup(const char *name)
767 struct clk_core *root_clk;
768 struct clk_core *ret;
773 /* search the 'proper' clk tree first */
774 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
775 ret = __clk_lookup_subtree(name, root_clk);
780 /* if not found, then search the orphan tree */
781 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
782 ret = __clk_lookup_subtree(name, root_clk);
790 static bool mux_is_better_rate(unsigned long rate, unsigned long now,
791 unsigned long best, unsigned long flags)
793 if (flags & CLK_MUX_ROUND_CLOSEST)
794 return abs(now - rate) < abs(best - rate);
796 return now <= rate && now > best;
800 clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
801 unsigned long min_rate,
802 unsigned long max_rate,
803 unsigned long *best_parent_rate,
804 struct clk_hw **best_parent_p,
807 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
809 unsigned long parent_rate, best = 0;
811 /* if NO_REPARENT flag set, pass through to current parent */
812 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
813 parent = core->parent;
814 if (core->flags & CLK_SET_RATE_PARENT)
815 best = __clk_determine_rate(parent ? parent->hw : NULL,
816 rate, min_rate, max_rate);
818 best = clk_core_get_rate_nolock(parent);
820 best = clk_core_get_rate_nolock(core);
824 /* find the parent that can provide the fastest rate <= rate */
825 num_parents = core->num_parents;
826 for (i = 0; i < num_parents; i++) {
827 parent = clk_core_get_parent_by_index(core, i);
830 if (core->flags & CLK_SET_RATE_PARENT)
831 parent_rate = __clk_determine_rate(parent->hw, rate,
835 parent_rate = clk_core_get_rate_nolock(parent);
836 if (mux_is_better_rate(rate, parent_rate, best, flags)) {
837 best_parent = parent;
844 *best_parent_p = best_parent->hw;
845 *best_parent_rate = best;
850 struct clk *__clk_lookup(const char *name)
852 struct clk_core *core = clk_core_lookup(name);
854 return !core ? NULL : core->hw->clk;
857 static void clk_core_get_boundaries(struct clk_core *clk,
858 unsigned long *min_rate,
859 unsigned long *max_rate)
861 struct clk *clk_user;
864 *max_rate = ULONG_MAX;
866 hlist_for_each_entry(clk_user, &clk->clks, clks_node)
867 *min_rate = max(*min_rate, clk_user->min_rate);
869 hlist_for_each_entry(clk_user, &clk->clks, clks_node)
870 *max_rate = min(*max_rate, clk_user->max_rate);
874 * Helper for finding best parent to provide a given frequency. This can be used
875 * directly as a determine_rate callback (e.g. for a mux), or from a more
876 * complex clock that may combine a mux with other operations.
878 long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
879 unsigned long min_rate,
880 unsigned long max_rate,
881 unsigned long *best_parent_rate,
882 struct clk_hw **best_parent_p)
884 return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
888 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
890 long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
891 unsigned long min_rate,
892 unsigned long max_rate,
893 unsigned long *best_parent_rate,
894 struct clk_hw **best_parent_p)
896 return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
899 CLK_MUX_ROUND_CLOSEST);
901 EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
905 static void clk_core_unprepare(struct clk_core *clk)
910 if (WARN_ON(clk->prepare_count == 0))
913 if (--clk->prepare_count > 0)
916 WARN_ON(clk->enable_count > 0);
918 trace_clk_unprepare(clk);
920 if (clk->ops->unprepare)
921 clk->ops->unprepare(clk->hw);
923 trace_clk_unprepare_complete(clk);
924 clk_core_unprepare(clk->parent);
928 * clk_unprepare - undo preparation of a clock source
929 * @clk: the clk being unprepared
931 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
932 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
933 * if the operation may sleep. One example is a clk which is accessed over
934 * I2c. In the complex case a clk gate operation may require a fast and a slow
935 * part. It is this reason that clk_unprepare and clk_disable are not mutually
936 * exclusive. In fact clk_disable must be called before clk_unprepare.
938 void clk_unprepare(struct clk *clk)
940 if (IS_ERR_OR_NULL(clk))
944 clk_core_unprepare(clk->core);
945 clk_prepare_unlock();
947 EXPORT_SYMBOL_GPL(clk_unprepare);
949 static int clk_core_prepare(struct clk_core *clk)
956 if (clk->prepare_count == 0) {
957 ret = clk_core_prepare(clk->parent);
961 trace_clk_prepare(clk);
963 if (clk->ops->prepare)
964 ret = clk->ops->prepare(clk->hw);
966 trace_clk_prepare_complete(clk);
969 clk_core_unprepare(clk->parent);
974 clk->prepare_count++;
980 * clk_prepare - prepare a clock source
981 * @clk: the clk being prepared
983 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
984 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
985 * operation may sleep. One example is a clk which is accessed over I2c. In
986 * the complex case a clk ungate operation may require a fast and a slow part.
987 * It is this reason that clk_prepare and clk_enable are not mutually
988 * exclusive. In fact clk_prepare must be called before clk_enable.
989 * Returns 0 on success, -EERROR otherwise.
991 int clk_prepare(struct clk *clk)
999 ret = clk_core_prepare(clk->core);
1000 clk_prepare_unlock();
1004 EXPORT_SYMBOL_GPL(clk_prepare);
1006 static void clk_core_disable(struct clk_core *clk)
1011 if (WARN_ON(clk->enable_count == 0))
1014 if (--clk->enable_count > 0)
1017 trace_clk_disable(clk);
1019 if (clk->ops->disable)
1020 clk->ops->disable(clk->hw);
1022 trace_clk_disable_complete(clk);
1024 clk_core_disable(clk->parent);
1027 static void __clk_disable(struct clk *clk)
1032 clk_core_disable(clk->core);
1036 * clk_disable - gate a clock
1037 * @clk: the clk being gated
1039 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
1040 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1041 * clk if the operation is fast and will never sleep. One example is a
1042 * SoC-internal clk which is controlled via simple register writes. In the
1043 * complex case a clk gate operation may require a fast and a slow part. It is
1044 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1045 * In fact clk_disable must be called before clk_unprepare.
1047 void clk_disable(struct clk *clk)
1049 unsigned long flags;
1051 if (IS_ERR_OR_NULL(clk))
1054 flags = clk_enable_lock();
1056 clk_enable_unlock(flags);
1058 EXPORT_SYMBOL_GPL(clk_disable);
1060 static int clk_core_enable(struct clk_core *clk)
1067 if (WARN_ON(clk->prepare_count == 0))
1070 if (clk->enable_count == 0) {
1071 ret = clk_core_enable(clk->parent);
1076 trace_clk_enable(clk);
1078 if (clk->ops->enable)
1079 ret = clk->ops->enable(clk->hw);
1081 trace_clk_enable_complete(clk);
1084 clk_core_disable(clk->parent);
1089 clk->enable_count++;
1093 static int __clk_enable(struct clk *clk)
1098 return clk_core_enable(clk->core);
1102 * clk_enable - ungate a clock
1103 * @clk: the clk being ungated
1105 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1106 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1107 * if the operation will never sleep. One example is a SoC-internal clk which
1108 * is controlled via simple register writes. In the complex case a clk ungate
1109 * operation may require a fast and a slow part. It is this reason that
1110 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1111 * must be called before clk_enable. Returns 0 on success, -EERROR
1114 int clk_enable(struct clk *clk)
1116 unsigned long flags;
1119 flags = clk_enable_lock();
1120 ret = __clk_enable(clk);
1121 clk_enable_unlock(flags);
1125 EXPORT_SYMBOL_GPL(clk_enable);
1127 static unsigned long clk_core_round_rate_nolock(struct clk_core *clk,
1129 unsigned long min_rate,
1130 unsigned long max_rate)
1132 unsigned long parent_rate = 0;
1133 struct clk_core *parent;
1134 struct clk_hw *parent_hw;
1136 lockdep_assert_held(&prepare_lock);
1141 parent = clk->parent;
1143 parent_rate = parent->rate;
1145 if (clk->ops->determine_rate) {
1146 parent_hw = parent ? parent->hw : NULL;
1147 return clk->ops->determine_rate(clk->hw, rate,
1149 &parent_rate, &parent_hw);
1150 } else if (clk->ops->round_rate)
1151 return clk->ops->round_rate(clk->hw, rate, &parent_rate);
1152 else if (clk->flags & CLK_SET_RATE_PARENT)
1153 return clk_core_round_rate_nolock(clk->parent, rate, min_rate,
1160 * __clk_determine_rate - get the closest rate actually supported by a clock
1161 * @hw: determine the rate of this clock
1162 * @rate: target rate
1163 * @min_rate: returned rate must be greater than this rate
1164 * @max_rate: returned rate must be less than this rate
1166 * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate and
1169 unsigned long __clk_determine_rate(struct clk_hw *hw,
1171 unsigned long min_rate,
1172 unsigned long max_rate)
1177 return clk_core_round_rate_nolock(hw->core, rate, min_rate, max_rate);
1179 EXPORT_SYMBOL_GPL(__clk_determine_rate);
1182 * __clk_round_rate - round the given rate for a clk
1183 * @clk: round the rate of this clock
1184 * @rate: the rate which is to be rounded
1186 * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate
1188 unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
1190 unsigned long min_rate;
1191 unsigned long max_rate;
1196 clk_core_get_boundaries(clk->core, &min_rate, &max_rate);
1198 return clk_core_round_rate_nolock(clk->core, rate, min_rate, max_rate);
1200 EXPORT_SYMBOL_GPL(__clk_round_rate);
1203 * clk_round_rate - round the given rate for a clk
1204 * @clk: the clk for which we are rounding a rate
1205 * @rate: the rate which is to be rounded
1207 * Takes in a rate as input and rounds it to a rate that the clk can actually
1208 * use which is then returned. If clk doesn't support round_rate operation
1209 * then the parent rate is returned.
1211 long clk_round_rate(struct clk *clk, unsigned long rate)
1219 ret = __clk_round_rate(clk, rate);
1220 clk_prepare_unlock();
1224 EXPORT_SYMBOL_GPL(clk_round_rate);
1227 * __clk_notify - call clk notifier chain
1228 * @clk: struct clk * that is changing rate
1229 * @msg: clk notifier type (see include/linux/clk.h)
1230 * @old_rate: old clk rate
1231 * @new_rate: new clk rate
1233 * Triggers a notifier call chain on the clk rate-change notification
1234 * for 'clk'. Passes a pointer to the struct clk and the previous
1235 * and current rates to the notifier callback. Intended to be called by
1236 * internal clock code only. Returns NOTIFY_DONE from the last driver
1237 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1238 * a driver returns that.
1240 static int __clk_notify(struct clk_core *clk, unsigned long msg,
1241 unsigned long old_rate, unsigned long new_rate)
1243 struct clk_notifier *cn;
1244 struct clk_notifier_data cnd;
1245 int ret = NOTIFY_DONE;
1247 cnd.old_rate = old_rate;
1248 cnd.new_rate = new_rate;
1250 list_for_each_entry(cn, &clk_notifier_list, node) {
1251 if (cn->clk->core == clk) {
1253 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1262 * __clk_recalc_accuracies
1263 * @clk: first clk in the subtree
1265 * Walks the subtree of clks starting with clk and recalculates accuracies as
1266 * it goes. Note that if a clk does not implement the .recalc_accuracy
1267 * callback then it is assumed that the clock will take on the accuracy of it's
1270 * Caller must hold prepare_lock.
1272 static void __clk_recalc_accuracies(struct clk_core *clk)
1274 unsigned long parent_accuracy = 0;
1275 struct clk_core *child;
1277 lockdep_assert_held(&prepare_lock);
1280 parent_accuracy = clk->parent->accuracy;
1282 if (clk->ops->recalc_accuracy)
1283 clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
1286 clk->accuracy = parent_accuracy;
1288 hlist_for_each_entry(child, &clk->children, child_node)
1289 __clk_recalc_accuracies(child);
1292 static long clk_core_get_accuracy(struct clk_core *clk)
1294 unsigned long accuracy;
1297 if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE))
1298 __clk_recalc_accuracies(clk);
1300 accuracy = __clk_get_accuracy(clk);
1301 clk_prepare_unlock();
1307 * clk_get_accuracy - return the accuracy of clk
1308 * @clk: the clk whose accuracy is being returned
1310 * Simply returns the cached accuracy of the clk, unless
1311 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1313 * If clk is NULL then returns 0.
1315 long clk_get_accuracy(struct clk *clk)
1320 return clk_core_get_accuracy(clk->core);
1322 EXPORT_SYMBOL_GPL(clk_get_accuracy);
1324 static unsigned long clk_recalc(struct clk_core *clk,
1325 unsigned long parent_rate)
1327 if (clk->ops->recalc_rate)
1328 return clk->ops->recalc_rate(clk->hw, parent_rate);
1333 * __clk_recalc_rates
1334 * @clk: first clk in the subtree
1335 * @msg: notification type (see include/linux/clk.h)
1337 * Walks the subtree of clks starting with clk and recalculates rates as it
1338 * goes. Note that if a clk does not implement the .recalc_rate callback then
1339 * it is assumed that the clock will take on the rate of its parent.
1341 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1344 * Caller must hold prepare_lock.
1346 static void __clk_recalc_rates(struct clk_core *clk, unsigned long msg)
1348 unsigned long old_rate;
1349 unsigned long parent_rate = 0;
1350 struct clk_core *child;
1352 lockdep_assert_held(&prepare_lock);
1354 old_rate = clk->rate;
1357 parent_rate = clk->parent->rate;
1359 clk->rate = clk_recalc(clk, parent_rate);
1362 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1363 * & ABORT_RATE_CHANGE notifiers
1365 if (clk->notifier_count && msg)
1366 __clk_notify(clk, msg, old_rate, clk->rate);
1368 hlist_for_each_entry(child, &clk->children, child_node)
1369 __clk_recalc_rates(child, msg);
1372 static unsigned long clk_core_get_rate(struct clk_core *clk)
1378 if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
1379 __clk_recalc_rates(clk, 0);
1381 rate = clk_core_get_rate_nolock(clk);
1382 clk_prepare_unlock();
1388 * clk_get_rate - return the rate of clk
1389 * @clk: the clk whose rate is being returned
1391 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1392 * is set, which means a recalc_rate will be issued.
1393 * If clk is NULL then returns 0.
1395 unsigned long clk_get_rate(struct clk *clk)
1400 return clk_core_get_rate(clk->core);
1402 EXPORT_SYMBOL_GPL(clk_get_rate);
1404 static int clk_fetch_parent_index(struct clk_core *clk,
1405 struct clk_core *parent)
1409 if (!clk->parents) {
1410 clk->parents = kcalloc(clk->num_parents,
1411 sizeof(struct clk *), GFP_KERNEL);
1417 * find index of new parent clock using cached parent ptrs,
1418 * or if not yet cached, use string name comparison and cache
1419 * them now to avoid future calls to clk_core_lookup.
1421 for (i = 0; i < clk->num_parents; i++) {
1422 if (clk->parents[i] == parent)
1425 if (clk->parents[i])
1428 if (!strcmp(clk->parent_names[i], parent->name)) {
1429 clk->parents[i] = clk_core_lookup(parent->name);
1437 static void clk_reparent(struct clk_core *clk, struct clk_core *new_parent)
1439 hlist_del(&clk->child_node);
1442 /* avoid duplicate POST_RATE_CHANGE notifications */
1443 if (new_parent->new_child == clk)
1444 new_parent->new_child = NULL;
1446 hlist_add_head(&clk->child_node, &new_parent->children);
1448 hlist_add_head(&clk->child_node, &clk_orphan_list);
1451 clk->parent = new_parent;
1454 static struct clk_core *__clk_set_parent_before(struct clk_core *clk,
1455 struct clk_core *parent)
1457 unsigned long flags;
1458 struct clk_core *old_parent = clk->parent;
1461 * Migrate prepare state between parents and prevent race with
1464 * If the clock is not prepared, then a race with
1465 * clk_enable/disable() is impossible since we already have the
1466 * prepare lock (future calls to clk_enable() need to be preceded by
1469 * If the clock is prepared, migrate the prepared state to the new
1470 * parent and also protect against a race with clk_enable() by
1471 * forcing the clock and the new parent on. This ensures that all
1472 * future calls to clk_enable() are practically NOPs with respect to
1473 * hardware and software states.
1475 * See also: Comment for clk_set_parent() below.
1477 if (clk->prepare_count) {
1478 clk_core_prepare(parent);
1479 flags = clk_enable_lock();
1480 clk_core_enable(parent);
1481 clk_core_enable(clk);
1482 clk_enable_unlock(flags);
1485 /* update the clk tree topology */
1486 flags = clk_enable_lock();
1487 clk_reparent(clk, parent);
1488 clk_enable_unlock(flags);
1493 static void __clk_set_parent_after(struct clk_core *core,
1494 struct clk_core *parent,
1495 struct clk_core *old_parent)
1497 unsigned long flags;
1500 * Finish the migration of prepare state and undo the changes done
1501 * for preventing a race with clk_enable().
1503 if (core->prepare_count) {
1504 flags = clk_enable_lock();
1505 clk_core_disable(core);
1506 clk_core_disable(old_parent);
1507 clk_enable_unlock(flags);
1508 clk_core_unprepare(old_parent);
1512 static int __clk_set_parent(struct clk_core *clk, struct clk_core *parent,
1515 unsigned long flags;
1517 struct clk_core *old_parent;
1519 old_parent = __clk_set_parent_before(clk, parent);
1521 trace_clk_set_parent(clk, parent);
1523 /* change clock input source */
1524 if (parent && clk->ops->set_parent)
1525 ret = clk->ops->set_parent(clk->hw, p_index);
1527 trace_clk_set_parent_complete(clk, parent);
1530 flags = clk_enable_lock();
1531 clk_reparent(clk, old_parent);
1532 clk_enable_unlock(flags);
1534 if (clk->prepare_count) {
1535 flags = clk_enable_lock();
1536 clk_core_disable(clk);
1537 clk_core_disable(parent);
1538 clk_enable_unlock(flags);
1539 clk_core_unprepare(parent);
1544 __clk_set_parent_after(clk, parent, old_parent);
1550 * __clk_speculate_rates
1551 * @clk: first clk in the subtree
1552 * @parent_rate: the "future" rate of clk's parent
1554 * Walks the subtree of clks starting with clk, speculating rates as it
1555 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1557 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1558 * pre-rate change notifications and returns early if no clks in the
1559 * subtree have subscribed to the notifications. Note that if a clk does not
1560 * implement the .recalc_rate callback then it is assumed that the clock will
1561 * take on the rate of its parent.
1563 * Caller must hold prepare_lock.
1565 static int __clk_speculate_rates(struct clk_core *clk,
1566 unsigned long parent_rate)
1568 struct clk_core *child;
1569 unsigned long new_rate;
1570 int ret = NOTIFY_DONE;
1572 lockdep_assert_held(&prepare_lock);
1574 new_rate = clk_recalc(clk, parent_rate);
1576 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1577 if (clk->notifier_count)
1578 ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate);
1580 if (ret & NOTIFY_STOP_MASK) {
1581 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1582 __func__, clk->name, ret);
1586 hlist_for_each_entry(child, &clk->children, child_node) {
1587 ret = __clk_speculate_rates(child, new_rate);
1588 if (ret & NOTIFY_STOP_MASK)
1596 static void clk_calc_subtree(struct clk_core *clk, unsigned long new_rate,
1597 struct clk_core *new_parent, u8 p_index)
1599 struct clk_core *child;
1601 clk->new_rate = new_rate;
1602 clk->new_parent = new_parent;
1603 clk->new_parent_index = p_index;
1604 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1605 clk->new_child = NULL;
1606 if (new_parent && new_parent != clk->parent)
1607 new_parent->new_child = clk;
1609 hlist_for_each_entry(child, &clk->children, child_node) {
1610 child->new_rate = clk_recalc(child, new_rate);
1611 clk_calc_subtree(child, child->new_rate, NULL, 0);
1616 * calculate the new rates returning the topmost clock that has to be
1619 static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
1622 struct clk_core *top = clk;
1623 struct clk_core *old_parent, *parent;
1624 struct clk_hw *parent_hw;
1625 unsigned long best_parent_rate = 0;
1626 unsigned long new_rate;
1627 unsigned long min_rate;
1628 unsigned long max_rate;
1633 if (IS_ERR_OR_NULL(clk))
1636 /* save parent rate, if it exists */
1637 parent = old_parent = clk->parent;
1639 best_parent_rate = parent->rate;
1641 clk_core_get_boundaries(clk, &min_rate, &max_rate);
1643 /* find the closest rate and parent clk/rate */
1644 if (clk->ops->determine_rate) {
1645 parent_hw = parent ? parent->hw : NULL;
1646 ret = clk->ops->determine_rate(clk->hw, rate,
1655 parent = parent_hw ? parent_hw->core : NULL;
1656 } else if (clk->ops->round_rate) {
1657 ret = clk->ops->round_rate(clk->hw, rate,
1663 if (new_rate < min_rate || new_rate > max_rate)
1665 } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) {
1666 /* pass-through clock without adjustable parent */
1667 clk->new_rate = clk->rate;
1670 /* pass-through clock with adjustable parent */
1671 top = clk_calc_new_rates(parent, rate);
1672 new_rate = parent->new_rate;
1676 /* some clocks must be gated to change parent */
1677 if (parent != old_parent &&
1678 (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
1679 pr_debug("%s: %s not gated but wants to reparent\n",
1680 __func__, clk->name);
1684 /* try finding the new parent index */
1685 if (parent && clk->num_parents > 1) {
1686 p_index = clk_fetch_parent_index(clk, parent);
1688 pr_debug("%s: clk %s can not be parent of clk %s\n",
1689 __func__, parent->name, clk->name);
1694 if ((clk->flags & CLK_SET_RATE_PARENT) && parent &&
1695 best_parent_rate != parent->rate)
1696 top = clk_calc_new_rates(parent, best_parent_rate);
1699 clk_calc_subtree(clk, new_rate, parent, p_index);
1705 * Notify about rate changes in a subtree. Always walk down the whole tree
1706 * so that in case of an error we can walk down the whole tree again and
1709 static struct clk_core *clk_propagate_rate_change(struct clk_core *clk,
1710 unsigned long event)
1712 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1713 int ret = NOTIFY_DONE;
1715 if (clk->rate == clk->new_rate)
1718 if (clk->notifier_count) {
1719 ret = __clk_notify(clk, event, clk->rate, clk->new_rate);
1720 if (ret & NOTIFY_STOP_MASK)
1724 hlist_for_each_entry(child, &clk->children, child_node) {
1725 /* Skip children who will be reparented to another clock */
1726 if (child->new_parent && child->new_parent != clk)
1728 tmp_clk = clk_propagate_rate_change(child, event);
1733 /* handle the new child who might not be in clk->children yet */
1734 if (clk->new_child) {
1735 tmp_clk = clk_propagate_rate_change(clk->new_child, event);
1744 * walk down a subtree and set the new rates notifying the rate
1747 static void clk_change_rate(struct clk_core *clk)
1749 struct clk_core *child;
1750 struct hlist_node *tmp;
1751 unsigned long old_rate;
1752 unsigned long best_parent_rate = 0;
1753 bool skip_set_rate = false;
1754 struct clk_core *old_parent;
1756 old_rate = clk->rate;
1758 if (clk->new_parent)
1759 best_parent_rate = clk->new_parent->rate;
1760 else if (clk->parent)
1761 best_parent_rate = clk->parent->rate;
1763 if (clk->new_parent && clk->new_parent != clk->parent) {
1764 old_parent = __clk_set_parent_before(clk, clk->new_parent);
1765 trace_clk_set_parent(clk, clk->new_parent);
1767 if (clk->ops->set_rate_and_parent) {
1768 skip_set_rate = true;
1769 clk->ops->set_rate_and_parent(clk->hw, clk->new_rate,
1771 clk->new_parent_index);
1772 } else if (clk->ops->set_parent) {
1773 clk->ops->set_parent(clk->hw, clk->new_parent_index);
1776 trace_clk_set_parent_complete(clk, clk->new_parent);
1777 __clk_set_parent_after(clk, clk->new_parent, old_parent);
1780 trace_clk_set_rate(clk, clk->new_rate);
1782 if (!skip_set_rate && clk->ops->set_rate)
1783 clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
1785 trace_clk_set_rate_complete(clk, clk->new_rate);
1787 clk->rate = clk_recalc(clk, best_parent_rate);
1789 if (clk->notifier_count && old_rate != clk->rate)
1790 __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
1793 * Use safe iteration, as change_rate can actually swap parents
1794 * for certain clock types.
1796 hlist_for_each_entry_safe(child, tmp, &clk->children, child_node) {
1797 /* Skip children who will be reparented to another clock */
1798 if (child->new_parent && child->new_parent != clk)
1800 clk_change_rate(child);
1803 /* handle the new child who might not be in clk->children yet */
1805 clk_change_rate(clk->new_child);
1808 static int clk_core_set_rate_nolock(struct clk_core *clk,
1809 unsigned long req_rate)
1811 struct clk_core *top, *fail_clk;
1812 unsigned long rate = req_rate;
1818 /* bail early if nothing to do */
1819 if (rate == clk_core_get_rate_nolock(clk))
1822 if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count)
1825 /* calculate new rates and get the topmost changed clock */
1826 top = clk_calc_new_rates(clk, rate);
1830 /* notify that we are about to change rates */
1831 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1833 pr_debug("%s: failed to set %s rate\n", __func__,
1835 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1839 /* change the rates */
1840 clk_change_rate(top);
1842 clk->req_rate = req_rate;
1848 * clk_set_rate - specify a new rate for clk
1849 * @clk: the clk whose rate is being changed
1850 * @rate: the new rate for clk
1852 * In the simplest case clk_set_rate will only adjust the rate of clk.
1854 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1855 * propagate up to clk's parent; whether or not this happens depends on the
1856 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1857 * after calling .round_rate then upstream parent propagation is ignored. If
1858 * *parent_rate comes back with a new rate for clk's parent then we propagate
1859 * up to clk's parent and set its rate. Upward propagation will continue
1860 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1861 * .round_rate stops requesting changes to clk's parent_rate.
1863 * Rate changes are accomplished via tree traversal that also recalculates the
1864 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1866 * Returns 0 on success, -EERROR otherwise.
1868 int clk_set_rate(struct clk *clk, unsigned long rate)
1875 /* prevent racing with updates to the clock topology */
1878 ret = clk_core_set_rate_nolock(clk->core, rate);
1880 clk_prepare_unlock();
1884 EXPORT_SYMBOL_GPL(clk_set_rate);
1887 * clk_set_rate_range - set a rate range for a clock source
1888 * @clk: clock source
1889 * @min: desired minimum clock rate in Hz, inclusive
1890 * @max: desired maximum clock rate in Hz, inclusive
1892 * Returns success (0) or negative errno.
1894 int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1902 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1903 __func__, clk->core->name, clk->dev_id, clk->con_id,
1910 if (min != clk->min_rate || max != clk->max_rate) {
1911 clk->min_rate = min;
1912 clk->max_rate = max;
1913 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1916 clk_prepare_unlock();
1920 EXPORT_SYMBOL_GPL(clk_set_rate_range);
1923 * clk_set_min_rate - set a minimum clock rate for a clock source
1924 * @clk: clock source
1925 * @rate: desired minimum clock rate in Hz, inclusive
1927 * Returns success (0) or negative errno.
1929 int clk_set_min_rate(struct clk *clk, unsigned long rate)
1934 return clk_set_rate_range(clk, rate, clk->max_rate);
1936 EXPORT_SYMBOL_GPL(clk_set_min_rate);
1939 * clk_set_max_rate - set a maximum clock rate for a clock source
1940 * @clk: clock source
1941 * @rate: desired maximum clock rate in Hz, inclusive
1943 * Returns success (0) or negative errno.
1945 int clk_set_max_rate(struct clk *clk, unsigned long rate)
1950 return clk_set_rate_range(clk, clk->min_rate, rate);
1952 EXPORT_SYMBOL_GPL(clk_set_max_rate);
1955 * clk_get_parent - return the parent of a clk
1956 * @clk: the clk whose parent gets returned
1958 * Simply returns clk->parent. Returns NULL if clk is NULL.
1960 struct clk *clk_get_parent(struct clk *clk)
1965 parent = __clk_get_parent(clk);
1966 clk_prepare_unlock();
1970 EXPORT_SYMBOL_GPL(clk_get_parent);
1973 * .get_parent is mandatory for clocks with multiple possible parents. It is
1974 * optional for single-parent clocks. Always call .get_parent if it is
1975 * available and WARN if it is missing for multi-parent clocks.
1977 * For single-parent clocks without .get_parent, first check to see if the
1978 * .parents array exists, and if so use it to avoid an expensive tree
1979 * traversal. If .parents does not exist then walk the tree.
1981 static struct clk_core *__clk_init_parent(struct clk_core *clk)
1983 struct clk_core *ret = NULL;
1986 /* handle the trivial cases */
1988 if (!clk->num_parents)
1991 if (clk->num_parents == 1) {
1992 if (IS_ERR_OR_NULL(clk->parent))
1993 clk->parent = clk_core_lookup(clk->parent_names[0]);
1998 if (!clk->ops->get_parent) {
1999 WARN(!clk->ops->get_parent,
2000 "%s: multi-parent clocks must implement .get_parent\n",
2006 * Do our best to cache parent clocks in clk->parents. This prevents
2007 * unnecessary and expensive lookups. We don't set clk->parent here;
2008 * that is done by the calling function.
2011 index = clk->ops->get_parent(clk->hw);
2015 kcalloc(clk->num_parents, sizeof(struct clk *),
2018 ret = clk_core_get_parent_by_index(clk, index);
2024 static void clk_core_reparent(struct clk_core *clk,
2025 struct clk_core *new_parent)
2027 clk_reparent(clk, new_parent);
2028 __clk_recalc_accuracies(clk);
2029 __clk_recalc_rates(clk, POST_RATE_CHANGE);
2033 * clk_has_parent - check if a clock is a possible parent for another
2034 * @clk: clock source
2035 * @parent: parent clock source
2037 * This function can be used in drivers that need to check that a clock can be
2038 * the parent of another without actually changing the parent.
2040 * Returns true if @parent is a possible parent for @clk, false otherwise.
2042 bool clk_has_parent(struct clk *clk, struct clk *parent)
2044 struct clk_core *core, *parent_core;
2047 /* NULL clocks should be nops, so return success if either is NULL. */
2048 if (!clk || !parent)
2052 parent_core = parent->core;
2054 /* Optimize for the case where the parent is already the parent. */
2055 if (core->parent == parent_core)
2058 for (i = 0; i < core->num_parents; i++)
2059 if (strcmp(core->parent_names[i], parent_core->name) == 0)
2064 EXPORT_SYMBOL_GPL(clk_has_parent);
2066 static int clk_core_set_parent(struct clk_core *clk, struct clk_core *parent)
2070 unsigned long p_rate = 0;
2075 /* prevent racing with updates to the clock topology */
2078 if (clk->parent == parent)
2081 /* verify ops for for multi-parent clks */
2082 if ((clk->num_parents > 1) && (!clk->ops->set_parent)) {
2087 /* check that we are allowed to re-parent if the clock is in use */
2088 if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
2093 /* try finding the new parent index */
2095 p_index = clk_fetch_parent_index(clk, parent);
2096 p_rate = parent->rate;
2098 pr_debug("%s: clk %s can not be parent of clk %s\n",
2099 __func__, parent->name, clk->name);
2105 /* propagate PRE_RATE_CHANGE notifications */
2106 ret = __clk_speculate_rates(clk, p_rate);
2108 /* abort if a driver objects */
2109 if (ret & NOTIFY_STOP_MASK)
2112 /* do the re-parent */
2113 ret = __clk_set_parent(clk, parent, p_index);
2115 /* propagate rate an accuracy recalculation accordingly */
2117 __clk_recalc_rates(clk, ABORT_RATE_CHANGE);
2119 __clk_recalc_rates(clk, POST_RATE_CHANGE);
2120 __clk_recalc_accuracies(clk);
2124 clk_prepare_unlock();
2130 * clk_set_parent - switch the parent of a mux clk
2131 * @clk: the mux clk whose input we are switching
2132 * @parent: the new input to clk
2134 * Re-parent clk to use parent as its new input source. If clk is in
2135 * prepared state, the clk will get enabled for the duration of this call. If
2136 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2137 * that, the reparenting is glitchy in hardware, etc), use the
2138 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2140 * After successfully changing clk's parent clk_set_parent will update the
2141 * clk topology, sysfs topology and propagate rate recalculation via
2142 * __clk_recalc_rates.
2144 * Returns 0 on success, -EERROR otherwise.
2146 int clk_set_parent(struct clk *clk, struct clk *parent)
2151 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
2153 EXPORT_SYMBOL_GPL(clk_set_parent);
2156 * clk_set_phase - adjust the phase shift of a clock signal
2157 * @clk: clock signal source
2158 * @degrees: number of degrees the signal is shifted
2160 * Shifts the phase of a clock signal by the specified
2161 * degrees. Returns 0 on success, -EERROR otherwise.
2163 * This function makes no distinction about the input or reference
2164 * signal that we adjust the clock signal phase against. For example
2165 * phase locked-loop clock signal generators we may shift phase with
2166 * respect to feedback clock signal input, but for other cases the
2167 * clock phase may be shifted with respect to some other, unspecified
2170 * Additionally the concept of phase shift does not propagate through
2171 * the clock tree hierarchy, which sets it apart from clock rates and
2172 * clock accuracy. A parent clock phase attribute does not have an
2173 * impact on the phase attribute of a child clock.
2175 int clk_set_phase(struct clk *clk, int degrees)
2182 /* sanity check degrees */
2189 trace_clk_set_phase(clk->core, degrees);
2191 if (clk->core->ops->set_phase)
2192 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
2194 trace_clk_set_phase_complete(clk->core, degrees);
2197 clk->core->phase = degrees;
2199 clk_prepare_unlock();
2203 EXPORT_SYMBOL_GPL(clk_set_phase);
2205 static int clk_core_get_phase(struct clk_core *clk)
2214 clk_prepare_unlock();
2219 EXPORT_SYMBOL_GPL(clk_get_phase);
2222 * clk_get_phase - return the phase shift of a clock signal
2223 * @clk: clock signal source
2225 * Returns the phase shift of a clock node in degrees, otherwise returns
2228 int clk_get_phase(struct clk *clk)
2233 return clk_core_get_phase(clk->core);
2237 * clk_is_match - check if two clk's point to the same hardware clock
2238 * @p: clk compared against q
2239 * @q: clk compared against p
2241 * Returns true if the two struct clk pointers both point to the same hardware
2242 * clock node. Put differently, returns true if struct clk *p and struct clk *q
2243 * share the same struct clk_core object.
2245 * Returns false otherwise. Note that two NULL clks are treated as matching.
2247 bool clk_is_match(const struct clk *p, const struct clk *q)
2249 /* trivial case: identical struct clk's or both NULL */
2253 /* true if clk->core pointers match. Avoid derefing garbage */
2254 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
2255 if (p->core == q->core)
2260 EXPORT_SYMBOL_GPL(clk_is_match);
2263 * __clk_init - initialize the data structures in a struct clk
2264 * @dev: device initializing this clk, placeholder for now
2265 * @clk: clk being initialized
2267 * Initializes the lists in struct clk_core, queries the hardware for the
2268 * parent and rate and sets them both.
2270 static int __clk_init(struct device *dev, struct clk *clk_user)
2273 struct clk_core *orphan;
2274 struct hlist_node *tmp2;
2275 struct clk_core *clk;
2281 clk = clk_user->core;
2285 /* check to see if a clock with this name is already registered */
2286 if (clk_core_lookup(clk->name)) {
2287 pr_debug("%s: clk %s already initialized\n",
2288 __func__, clk->name);
2293 /* check that clk_ops are sane. See Documentation/clk.txt */
2294 if (clk->ops->set_rate &&
2295 !((clk->ops->round_rate || clk->ops->determine_rate) &&
2296 clk->ops->recalc_rate)) {
2297 pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2298 __func__, clk->name);
2303 if (clk->ops->set_parent && !clk->ops->get_parent) {
2304 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
2305 __func__, clk->name);
2310 if (clk->ops->set_rate_and_parent &&
2311 !(clk->ops->set_parent && clk->ops->set_rate)) {
2312 pr_warn("%s: %s must implement .set_parent & .set_rate\n",
2313 __func__, clk->name);
2318 /* throw a WARN if any entries in parent_names are NULL */
2319 for (i = 0; i < clk->num_parents; i++)
2320 WARN(!clk->parent_names[i],
2321 "%s: invalid NULL in %s's .parent_names\n",
2322 __func__, clk->name);
2325 * Allocate an array of struct clk *'s to avoid unnecessary string
2326 * look-ups of clk's possible parents. This can fail for clocks passed
2327 * in to clk_init during early boot; thus any access to clk->parents[]
2328 * must always check for a NULL pointer and try to populate it if
2331 * If clk->parents is not NULL we skip this entire block. This allows
2332 * for clock drivers to statically initialize clk->parents.
2334 if (clk->num_parents > 1 && !clk->parents) {
2335 clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *),
2338 * clk_core_lookup returns NULL for parents that have not been
2339 * clk_init'd; thus any access to clk->parents[] must check
2340 * for a NULL pointer. We can always perform lazy lookups for
2341 * missing parents later on.
2344 for (i = 0; i < clk->num_parents; i++)
2346 clk_core_lookup(clk->parent_names[i]);
2349 clk->parent = __clk_init_parent(clk);
2352 * Populate clk->parent if parent has already been __clk_init'd. If
2353 * parent has not yet been __clk_init'd then place clk in the orphan
2354 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
2357 * Every time a new clk is clk_init'd then we walk the list of orphan
2358 * clocks and re-parent any that are children of the clock currently
2362 hlist_add_head(&clk->child_node,
2363 &clk->parent->children);
2364 else if (clk->flags & CLK_IS_ROOT)
2365 hlist_add_head(&clk->child_node, &clk_root_list);
2367 hlist_add_head(&clk->child_node, &clk_orphan_list);
2370 * Set clk's accuracy. The preferred method is to use
2371 * .recalc_accuracy. For simple clocks and lazy developers the default
2372 * fallback is to use the parent's accuracy. If a clock doesn't have a
2373 * parent (or is orphaned) then accuracy is set to zero (perfect
2376 if (clk->ops->recalc_accuracy)
2377 clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
2378 __clk_get_accuracy(clk->parent));
2379 else if (clk->parent)
2380 clk->accuracy = clk->parent->accuracy;
2386 * Since a phase is by definition relative to its parent, just
2387 * query the current clock phase, or just assume it's in phase.
2389 if (clk->ops->get_phase)
2390 clk->phase = clk->ops->get_phase(clk->hw);
2395 * Set clk's rate. The preferred method is to use .recalc_rate. For
2396 * simple clocks and lazy developers the default fallback is to use the
2397 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2398 * then rate is set to zero.
2400 if (clk->ops->recalc_rate)
2401 rate = clk->ops->recalc_rate(clk->hw,
2402 clk_core_get_rate_nolock(clk->parent));
2403 else if (clk->parent)
2404 rate = clk->parent->rate;
2407 clk->rate = clk->req_rate = rate;
2410 * walk the list of orphan clocks and reparent any that are children of
2413 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
2414 if (orphan->num_parents && orphan->ops->get_parent) {
2415 i = orphan->ops->get_parent(orphan->hw);
2416 if (!strcmp(clk->name, orphan->parent_names[i]))
2417 clk_core_reparent(orphan, clk);
2421 for (i = 0; i < orphan->num_parents; i++)
2422 if (!strcmp(clk->name, orphan->parent_names[i])) {
2423 clk_core_reparent(orphan, clk);
2429 * optional platform-specific magic
2431 * The .init callback is not used by any of the basic clock types, but
2432 * exists for weird hardware that must perform initialization magic.
2433 * Please consider other ways of solving initialization problems before
2434 * using this callback, as its use is discouraged.
2437 clk->ops->init(clk->hw);
2439 kref_init(&clk->ref);
2441 clk_prepare_unlock();
2444 clk_debug_register(clk);
2449 struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2454 /* This is to allow this function to be chained to others */
2455 if (!hw || IS_ERR(hw))
2456 return (struct clk *) hw;
2458 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2460 return ERR_PTR(-ENOMEM);
2462 clk->core = hw->core;
2463 clk->dev_id = dev_id;
2464 clk->con_id = con_id;
2465 clk->max_rate = ULONG_MAX;
2468 hlist_add_head(&clk->clks_node, &hw->core->clks);
2469 clk_prepare_unlock();
2474 void __clk_free_clk(struct clk *clk)
2477 hlist_del(&clk->clks_node);
2478 clk_prepare_unlock();
2484 * clk_register - allocate a new clock, register it and return an opaque cookie
2485 * @dev: device that is registering this clock
2486 * @hw: link to hardware-specific clock data
2488 * clk_register is the primary interface for populating the clock tree with new
2489 * clock nodes. It returns a pointer to the newly allocated struct clk which
2490 * cannot be dereferenced by driver code but may be used in conjuction with the
2491 * rest of the clock API. In the event of an error clk_register will return an
2492 * error code; drivers must test for an error code after calling clk_register.
2494 struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2497 struct clk_core *clk;
2499 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2501 pr_err("%s: could not allocate clk\n", __func__);
2506 clk->name = kstrdup_const(hw->init->name, GFP_KERNEL);
2508 pr_err("%s: could not allocate clk->name\n", __func__);
2512 clk->ops = hw->init->ops;
2513 if (dev && dev->driver)
2514 clk->owner = dev->driver->owner;
2516 clk->flags = hw->init->flags;
2517 clk->num_parents = hw->init->num_parents;
2520 /* allocate local copy in case parent_names is __initdata */
2521 clk->parent_names = kcalloc(clk->num_parents, sizeof(char *),
2524 if (!clk->parent_names) {
2525 pr_err("%s: could not allocate clk->parent_names\n", __func__);
2527 goto fail_parent_names;
2531 /* copy each string name in case parent_names is __initdata */
2532 for (i = 0; i < clk->num_parents; i++) {
2533 clk->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
2535 if (!clk->parent_names[i]) {
2536 pr_err("%s: could not copy parent_names\n", __func__);
2538 goto fail_parent_names_copy;
2542 INIT_HLIST_HEAD(&clk->clks);
2544 hw->clk = __clk_create_clk(hw, NULL, NULL);
2545 if (IS_ERR(hw->clk)) {
2546 pr_err("%s: could not allocate per-user clk\n", __func__);
2547 ret = PTR_ERR(hw->clk);
2548 goto fail_parent_names_copy;
2551 ret = __clk_init(dev, hw->clk);
2555 __clk_free_clk(hw->clk);
2558 fail_parent_names_copy:
2560 kfree_const(clk->parent_names[i]);
2561 kfree(clk->parent_names);
2563 kfree_const(clk->name);
2567 return ERR_PTR(ret);
2569 EXPORT_SYMBOL_GPL(clk_register);
2572 * Free memory allocated for a clock.
2573 * Caller must hold prepare_lock.
2575 static void __clk_release(struct kref *ref)
2577 struct clk_core *clk = container_of(ref, struct clk_core, ref);
2578 int i = clk->num_parents;
2580 lockdep_assert_held(&prepare_lock);
2582 kfree(clk->parents);
2584 kfree_const(clk->parent_names[i]);
2586 kfree(clk->parent_names);
2587 kfree_const(clk->name);
2592 * Empty clk_ops for unregistered clocks. These are used temporarily
2593 * after clk_unregister() was called on a clock and until last clock
2594 * consumer calls clk_put() and the struct clk object is freed.
2596 static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2601 static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2606 static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2607 unsigned long parent_rate)
2612 static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2617 static const struct clk_ops clk_nodrv_ops = {
2618 .enable = clk_nodrv_prepare_enable,
2619 .disable = clk_nodrv_disable_unprepare,
2620 .prepare = clk_nodrv_prepare_enable,
2621 .unprepare = clk_nodrv_disable_unprepare,
2622 .set_rate = clk_nodrv_set_rate,
2623 .set_parent = clk_nodrv_set_parent,
2627 * clk_unregister - unregister a currently registered clock
2628 * @clk: clock to unregister
2630 void clk_unregister(struct clk *clk)
2632 unsigned long flags;
2634 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2637 clk_debug_unregister(clk->core);
2641 if (clk->core->ops == &clk_nodrv_ops) {
2642 pr_err("%s: unregistered clock: %s\n", __func__,
2647 * Assign empty clock ops for consumers that might still hold
2648 * a reference to this clock.
2650 flags = clk_enable_lock();
2651 clk->core->ops = &clk_nodrv_ops;
2652 clk_enable_unlock(flags);
2654 if (!hlist_empty(&clk->core->children)) {
2655 struct clk_core *child;
2656 struct hlist_node *t;
2658 /* Reparent all children to the orphan list. */
2659 hlist_for_each_entry_safe(child, t, &clk->core->children,
2661 clk_core_set_parent(child, NULL);
2664 hlist_del_init(&clk->core->child_node);
2666 if (clk->core->prepare_count)
2667 pr_warn("%s: unregistering prepared clock: %s\n",
2668 __func__, clk->core->name);
2669 kref_put(&clk->core->ref, __clk_release);
2671 clk_prepare_unlock();
2673 EXPORT_SYMBOL_GPL(clk_unregister);
2675 static void devm_clk_release(struct device *dev, void *res)
2677 clk_unregister(*(struct clk **)res);
2681 * devm_clk_register - resource managed clk_register()
2682 * @dev: device that is registering this clock
2683 * @hw: link to hardware-specific clock data
2685 * Managed clk_register(). Clocks returned from this function are
2686 * automatically clk_unregister()ed on driver detach. See clk_register() for
2689 struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2694 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2696 return ERR_PTR(-ENOMEM);
2698 clk = clk_register(dev, hw);
2701 devres_add(dev, clkp);
2708 EXPORT_SYMBOL_GPL(devm_clk_register);
2710 static int devm_clk_match(struct device *dev, void *res, void *data)
2712 struct clk *c = res;
2719 * devm_clk_unregister - resource managed clk_unregister()
2720 * @clk: clock to unregister
2722 * Deallocate a clock allocated with devm_clk_register(). Normally
2723 * this function will not need to be called and the resource management
2724 * code will ensure that the resource is freed.
2726 void devm_clk_unregister(struct device *dev, struct clk *clk)
2728 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2730 EXPORT_SYMBOL_GPL(devm_clk_unregister);
2735 int __clk_get(struct clk *clk)
2737 struct clk_core *core = !clk ? NULL : clk->core;
2740 if (!try_module_get(core->owner))
2743 kref_get(&core->ref);
2748 void __clk_put(struct clk *clk)
2750 struct module *owner;
2752 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2757 hlist_del(&clk->clks_node);
2758 if (clk->min_rate > clk->core->req_rate ||
2759 clk->max_rate < clk->core->req_rate)
2760 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2762 owner = clk->core->owner;
2763 kref_put(&clk->core->ref, __clk_release);
2765 clk_prepare_unlock();
2772 /*** clk rate change notifiers ***/
2775 * clk_notifier_register - add a clk rate change notifier
2776 * @clk: struct clk * to watch
2777 * @nb: struct notifier_block * with callback info
2779 * Request notification when clk's rate changes. This uses an SRCU
2780 * notifier because we want it to block and notifier unregistrations are
2781 * uncommon. The callbacks associated with the notifier must not
2782 * re-enter into the clk framework by calling any top-level clk APIs;
2783 * this will cause a nested prepare_lock mutex.
2785 * In all notification cases cases (pre, post and abort rate change) the
2786 * original clock rate is passed to the callback via struct
2787 * clk_notifier_data.old_rate and the new frequency is passed via struct
2788 * clk_notifier_data.new_rate.
2790 * clk_notifier_register() must be called from non-atomic context.
2791 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2792 * allocation failure; otherwise, passes along the return value of
2793 * srcu_notifier_chain_register().
2795 int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2797 struct clk_notifier *cn;
2805 /* search the list of notifiers for this clk */
2806 list_for_each_entry(cn, &clk_notifier_list, node)
2810 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2811 if (cn->clk != clk) {
2812 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2817 srcu_init_notifier_head(&cn->notifier_head);
2819 list_add(&cn->node, &clk_notifier_list);
2822 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2824 clk->core->notifier_count++;
2827 clk_prepare_unlock();
2831 EXPORT_SYMBOL_GPL(clk_notifier_register);
2834 * clk_notifier_unregister - remove a clk rate change notifier
2835 * @clk: struct clk *
2836 * @nb: struct notifier_block * with callback info
2838 * Request no further notification for changes to 'clk' and frees memory
2839 * allocated in clk_notifier_register.
2841 * Returns -EINVAL if called with null arguments; otherwise, passes
2842 * along the return value of srcu_notifier_chain_unregister().
2844 int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2846 struct clk_notifier *cn = NULL;
2854 list_for_each_entry(cn, &clk_notifier_list, node)
2858 if (cn->clk == clk) {
2859 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2861 clk->core->notifier_count--;
2863 /* XXX the notifier code should handle this better */
2864 if (!cn->notifier_head.head) {
2865 srcu_cleanup_notifier_head(&cn->notifier_head);
2866 list_del(&cn->node);
2874 clk_prepare_unlock();
2878 EXPORT_SYMBOL_GPL(clk_notifier_unregister);
2882 * struct of_clk_provider - Clock provider registration structure
2883 * @link: Entry in global list of clock providers
2884 * @node: Pointer to device tree node of clock provider
2885 * @get: Get clock callback. Returns NULL or a struct clk for the
2886 * given clock specifier
2887 * @data: context pointer to be passed into @get callback
2889 struct of_clk_provider {
2890 struct list_head link;
2892 struct device_node *node;
2893 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2897 static const struct of_device_id __clk_of_table_sentinel
2898 __used __section(__clk_of_table_end);
2900 static LIST_HEAD(of_clk_providers);
2901 static DEFINE_MUTEX(of_clk_mutex);
2903 struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2908 EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2910 struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2912 struct clk_onecell_data *clk_data = data;
2913 unsigned int idx = clkspec->args[0];
2915 if (idx >= clk_data->clk_num) {
2916 pr_err("%s: invalid clock index %d\n", __func__, idx);
2917 return ERR_PTR(-EINVAL);
2920 return clk_data->clks[idx];
2922 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2925 * of_clk_add_provider() - Register a clock provider for a node
2926 * @np: Device node pointer associated with clock provider
2927 * @clk_src_get: callback for decoding clock
2928 * @data: context pointer for @clk_src_get callback.
2930 int of_clk_add_provider(struct device_node *np,
2931 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2935 struct of_clk_provider *cp;
2938 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2942 cp->node = of_node_get(np);
2944 cp->get = clk_src_get;
2946 mutex_lock(&of_clk_mutex);
2947 list_add(&cp->link, &of_clk_providers);
2948 mutex_unlock(&of_clk_mutex);
2949 pr_debug("Added clock from %s\n", np->full_name);
2951 ret = of_clk_set_defaults(np, true);
2953 of_clk_del_provider(np);
2957 EXPORT_SYMBOL_GPL(of_clk_add_provider);
2960 * of_clk_del_provider() - Remove a previously registered clock provider
2961 * @np: Device node pointer associated with clock provider
2963 void of_clk_del_provider(struct device_node *np)
2965 struct of_clk_provider *cp;
2967 mutex_lock(&of_clk_mutex);
2968 list_for_each_entry(cp, &of_clk_providers, link) {
2969 if (cp->node == np) {
2970 list_del(&cp->link);
2971 of_node_put(cp->node);
2976 mutex_unlock(&of_clk_mutex);
2978 EXPORT_SYMBOL_GPL(of_clk_del_provider);
2980 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
2981 const char *dev_id, const char *con_id)
2983 struct of_clk_provider *provider;
2984 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
2987 return ERR_PTR(-EINVAL);
2989 /* Check if we have such a provider in our array */
2990 mutex_lock(&of_clk_mutex);
2991 list_for_each_entry(provider, &of_clk_providers, link) {
2992 if (provider->node == clkspec->np)
2993 clk = provider->get(clkspec, provider->data);
2995 clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
2998 if (!IS_ERR(clk) && !__clk_get(clk)) {
2999 __clk_free_clk(clk);
3000 clk = ERR_PTR(-ENOENT);
3006 mutex_unlock(&of_clk_mutex);
3012 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3013 * @clkspec: pointer to a clock specifier data structure
3015 * This function looks up a struct clk from the registered list of clock
3016 * providers, an input is a clock specifier data structure as returned
3017 * from the of_parse_phandle_with_args() function call.
3019 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3021 return __of_clk_get_from_provider(clkspec, NULL, __func__);
3024 int of_clk_get_parent_count(struct device_node *np)
3026 return of_count_phandle_with_args(np, "clocks", "#clock-cells");
3028 EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3030 const char *of_clk_get_parent_name(struct device_node *np, int index)
3032 struct of_phandle_args clkspec;
3033 struct property *prop;
3034 const char *clk_name;
3043 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3048 index = clkspec.args_count ? clkspec.args[0] : 0;
3051 /* if there is an indices property, use it to transfer the index
3052 * specified into an array offset for the clock-output-names property.
3054 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3062 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3065 clk_name = clkspec.np->name;
3067 of_node_put(clkspec.np);
3070 EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3072 struct clock_provider {
3073 of_clk_init_cb_t clk_init_cb;
3074 struct device_node *np;
3075 struct list_head node;
3078 static LIST_HEAD(clk_provider_list);
3081 * This function looks for a parent clock. If there is one, then it
3082 * checks that the provider for this parent clock was initialized, in
3083 * this case the parent clock will be ready.
3085 static int parent_ready(struct device_node *np)
3090 struct clk *clk = of_clk_get(np, i);
3092 /* this parent is ready we can check the next one */
3099 /* at least one parent is not ready, we exit now */
3100 if (PTR_ERR(clk) == -EPROBE_DEFER)
3104 * Here we make assumption that the device tree is
3105 * written correctly. So an error means that there is
3106 * no more parent. As we didn't exit yet, then the
3107 * previous parent are ready. If there is no clock
3108 * parent, no need to wait for them, then we can
3109 * consider their absence as being ready
3116 * of_clk_init() - Scan and init clock providers from the DT
3117 * @matches: array of compatible values and init functions for providers.
3119 * This function scans the device tree for matching clock providers
3120 * and calls their initialization functions. It also does it by trying
3121 * to follow the dependencies.
3123 void __init of_clk_init(const struct of_device_id *matches)
3125 const struct of_device_id *match;
3126 struct device_node *np;
3127 struct clock_provider *clk_provider, *next;
3132 matches = &__clk_of_table;
3134 /* First prepare the list of the clocks providers */
3135 for_each_matching_node_and_match(np, matches, &match) {
3136 struct clock_provider *parent =
3137 kzalloc(sizeof(struct clock_provider), GFP_KERNEL);
3139 parent->clk_init_cb = match->data;
3141 list_add_tail(&parent->node, &clk_provider_list);
3144 while (!list_empty(&clk_provider_list)) {
3145 is_init_done = false;
3146 list_for_each_entry_safe(clk_provider, next,
3147 &clk_provider_list, node) {
3148 if (force || parent_ready(clk_provider->np)) {
3150 clk_provider->clk_init_cb(clk_provider->np);
3151 of_clk_set_defaults(clk_provider->np, true);
3153 list_del(&clk_provider->node);
3154 kfree(clk_provider);
3155 is_init_done = true;
3160 * We didn't manage to initialize any of the
3161 * remaining providers during the last loop, so now we
3162 * initialize all the remaining ones unconditionally
3163 * in case the clock parent was not mandatory