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-private.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/spinlock.h>
16 #include <linux/err.h>
17 #include <linux/list.h>
18 #include <linux/slab.h>
20 #include <linux/device.h>
21 #include <linux/init.h>
23 static DEFINE_SPINLOCK(enable_lock
);
24 static DEFINE_MUTEX(prepare_lock
);
26 static HLIST_HEAD(clk_root_list
);
27 static HLIST_HEAD(clk_orphan_list
);
28 static LIST_HEAD(clk_notifier_list
);
31 static void clk_prepare_lock(void)
33 mutex_lock(&prepare_lock
);
36 static void clk_prepare_unlock(void)
38 mutex_unlock(&prepare_lock
);
41 static unsigned long clk_enable_lock(void)
44 spin_lock_irqsave(&enable_lock
, flags
);
48 static void clk_enable_unlock(unsigned long flags
)
50 spin_unlock_irqrestore(&enable_lock
, flags
);
53 /*** debugfs support ***/
55 #ifdef CONFIG_COMMON_CLK_DEBUG
56 #include <linux/debugfs.h>
58 static struct dentry
*rootdir
;
59 static struct dentry
*orphandir
;
60 static int inited
= 0;
62 static void clk_summary_show_one(struct seq_file
*s
, struct clk
*c
, int level
)
67 seq_printf(s
, "%*s%-*s %-11d %-12d %-10lu",
69 30 - level
* 3, c
->name
,
70 c
->enable_count
, c
->prepare_count
, c
->rate
);
74 static void clk_summary_show_subtree(struct seq_file
*s
, struct clk
*c
,
82 clk_summary_show_one(s
, c
, level
);
84 hlist_for_each_entry(child
, &c
->children
, child_node
)
85 clk_summary_show_subtree(s
, child
, level
+ 1);
88 static int clk_summary_show(struct seq_file
*s
, void *data
)
92 seq_printf(s
, " clock enable_cnt prepare_cnt rate\n");
93 seq_printf(s
, "---------------------------------------------------------------------\n");
97 hlist_for_each_entry(c
, &clk_root_list
, child_node
)
98 clk_summary_show_subtree(s
, c
, 0);
100 hlist_for_each_entry(c
, &clk_orphan_list
, child_node
)
101 clk_summary_show_subtree(s
, c
, 0);
103 clk_prepare_unlock();
109 static int clk_summary_open(struct inode
*inode
, struct file
*file
)
111 return single_open(file
, clk_summary_show
, inode
->i_private
);
114 static const struct file_operations clk_summary_fops
= {
115 .open
= clk_summary_open
,
118 .release
= single_release
,
121 static void clk_dump_one(struct seq_file
*s
, struct clk
*c
, int level
)
126 seq_printf(s
, "\"%s\": { ", c
->name
);
127 seq_printf(s
, "\"enable_count\": %d,", c
->enable_count
);
128 seq_printf(s
, "\"prepare_count\": %d,", c
->prepare_count
);
129 seq_printf(s
, "\"rate\": %lu", c
->rate
);
132 static void clk_dump_subtree(struct seq_file
*s
, struct clk
*c
, int level
)
139 clk_dump_one(s
, c
, level
);
141 hlist_for_each_entry(child
, &c
->children
, child_node
) {
143 clk_dump_subtree(s
, child
, level
+ 1);
149 static int clk_dump(struct seq_file
*s
, void *data
)
152 bool first_node
= true;
158 hlist_for_each_entry(c
, &clk_root_list
, child_node
) {
162 clk_dump_subtree(s
, c
, 0);
165 hlist_for_each_entry(c
, &clk_orphan_list
, child_node
) {
167 clk_dump_subtree(s
, c
, 0);
170 clk_prepare_unlock();
177 static int clk_dump_open(struct inode
*inode
, struct file
*file
)
179 return single_open(file
, clk_dump
, inode
->i_private
);
182 static const struct file_operations clk_dump_fops
= {
183 .open
= clk_dump_open
,
186 .release
= single_release
,
189 /* caller must hold prepare_lock */
190 static int clk_debug_create_one(struct clk
*clk
, struct dentry
*pdentry
)
195 if (!clk
|| !pdentry
) {
200 d
= debugfs_create_dir(clk
->name
, pdentry
);
206 d
= debugfs_create_u32("clk_rate", S_IRUGO
, clk
->dentry
,
211 d
= debugfs_create_x32("clk_flags", S_IRUGO
, clk
->dentry
,
216 d
= debugfs_create_u32("clk_prepare_count", S_IRUGO
, clk
->dentry
,
217 (u32
*)&clk
->prepare_count
);
221 d
= debugfs_create_u32("clk_enable_count", S_IRUGO
, clk
->dentry
,
222 (u32
*)&clk
->enable_count
);
226 d
= debugfs_create_u32("clk_notifier_count", S_IRUGO
, clk
->dentry
,
227 (u32
*)&clk
->notifier_count
);
235 debugfs_remove(clk
->dentry
);
240 /* caller must hold prepare_lock */
241 static int clk_debug_create_subtree(struct clk
*clk
, struct dentry
*pdentry
)
246 if (!clk
|| !pdentry
)
249 ret
= clk_debug_create_one(clk
, pdentry
);
254 hlist_for_each_entry(child
, &clk
->children
, child_node
)
255 clk_debug_create_subtree(child
, clk
->dentry
);
263 * clk_debug_register - add a clk node to the debugfs clk tree
264 * @clk: the clk being added to the debugfs clk tree
266 * Dynamically adds a clk to the debugfs clk tree if debugfs has been
267 * initialized. Otherwise it bails out early since the debugfs clk tree
268 * will be created lazily by clk_debug_init as part of a late_initcall.
270 * Caller must hold prepare_lock. Only clk_init calls this function (so
271 * far) so this is taken care.
273 static int clk_debug_register(struct clk
*clk
)
276 struct dentry
*pdentry
;
282 parent
= clk
->parent
;
285 * Check to see if a clk is a root clk. Also check that it is
286 * safe to add this clk to debugfs
289 if (clk
->flags
& CLK_IS_ROOT
)
295 pdentry
= parent
->dentry
;
299 ret
= clk_debug_create_subtree(clk
, pdentry
);
306 * clk_debug_init - lazily create the debugfs clk tree visualization
308 * clks are often initialized very early during boot before memory can
309 * be dynamically allocated and well before debugfs is setup.
310 * clk_debug_init walks the clk tree hierarchy while holding
311 * prepare_lock and creates the topology as part of a late_initcall,
312 * thus insuring that clks initialized very early will still be
313 * represented in the debugfs clk tree. This function should only be
314 * called once at boot-time, and all other clks added dynamically will
315 * be done so with clk_debug_register.
317 static int __init
clk_debug_init(void)
322 rootdir
= debugfs_create_dir("clk", NULL
);
327 d
= debugfs_create_file("clk_summary", S_IRUGO
, rootdir
, NULL
,
332 d
= debugfs_create_file("clk_dump", S_IRUGO
, rootdir
, NULL
,
337 orphandir
= debugfs_create_dir("orphans", rootdir
);
344 hlist_for_each_entry(clk
, &clk_root_list
, child_node
)
345 clk_debug_create_subtree(clk
, rootdir
);
347 hlist_for_each_entry(clk
, &clk_orphan_list
, child_node
)
348 clk_debug_create_subtree(clk
, orphandir
);
352 clk_prepare_unlock();
356 late_initcall(clk_debug_init
);
358 static inline int clk_debug_register(struct clk
*clk
) { return 0; }
361 /* caller must hold prepare_lock */
362 static void clk_unprepare_unused_subtree(struct clk
*clk
)
369 hlist_for_each_entry(child
, &clk
->children
, child_node
)
370 clk_unprepare_unused_subtree(child
);
372 if (clk
->prepare_count
)
375 if (clk
->flags
& CLK_IGNORE_UNUSED
)
378 if (__clk_is_prepared(clk
)) {
379 if (clk
->ops
->unprepare_unused
)
380 clk
->ops
->unprepare_unused(clk
->hw
);
381 else if (clk
->ops
->unprepare
)
382 clk
->ops
->unprepare(clk
->hw
);
386 /* caller must hold prepare_lock */
387 static void clk_disable_unused_subtree(struct clk
*clk
)
395 hlist_for_each_entry(child
, &clk
->children
, child_node
)
396 clk_disable_unused_subtree(child
);
398 flags
= clk_enable_lock();
400 if (clk
->enable_count
)
403 if (clk
->flags
& CLK_IGNORE_UNUSED
)
407 * some gate clocks have special needs during the disable-unused
408 * sequence. call .disable_unused if available, otherwise fall
411 if (__clk_is_enabled(clk
)) {
412 if (clk
->ops
->disable_unused
)
413 clk
->ops
->disable_unused(clk
->hw
);
414 else if (clk
->ops
->disable
)
415 clk
->ops
->disable(clk
->hw
);
419 clk_enable_unlock(flags
);
425 static int clk_disable_unused(void)
431 hlist_for_each_entry(clk
, &clk_root_list
, child_node
)
432 clk_disable_unused_subtree(clk
);
434 hlist_for_each_entry(clk
, &clk_orphan_list
, child_node
)
435 clk_disable_unused_subtree(clk
);
437 hlist_for_each_entry(clk
, &clk_root_list
, child_node
)
438 clk_unprepare_unused_subtree(clk
);
440 hlist_for_each_entry(clk
, &clk_orphan_list
, child_node
)
441 clk_unprepare_unused_subtree(clk
);
443 clk_prepare_unlock();
447 late_initcall(clk_disable_unused
);
449 /*** helper functions ***/
451 const char *__clk_get_name(struct clk
*clk
)
453 return !clk
? NULL
: clk
->name
;
455 EXPORT_SYMBOL_GPL(__clk_get_name
);
457 struct clk_hw
*__clk_get_hw(struct clk
*clk
)
459 return !clk
? NULL
: clk
->hw
;
462 u8
__clk_get_num_parents(struct clk
*clk
)
464 return !clk
? 0 : clk
->num_parents
;
467 struct clk
*__clk_get_parent(struct clk
*clk
)
469 return !clk
? NULL
: clk
->parent
;
472 unsigned int __clk_get_enable_count(struct clk
*clk
)
474 return !clk
? 0 : clk
->enable_count
;
477 unsigned int __clk_get_prepare_count(struct clk
*clk
)
479 return !clk
? 0 : clk
->prepare_count
;
482 unsigned long __clk_get_rate(struct clk
*clk
)
493 if (clk
->flags
& CLK_IS_ROOT
)
503 unsigned long __clk_get_flags(struct clk
*clk
)
505 return !clk
? 0 : clk
->flags
;
508 bool __clk_is_prepared(struct clk
*clk
)
516 * .is_prepared is optional for clocks that can prepare
517 * fall back to software usage counter if it is missing
519 if (!clk
->ops
->is_prepared
) {
520 ret
= clk
->prepare_count
? 1 : 0;
524 ret
= clk
->ops
->is_prepared(clk
->hw
);
529 bool __clk_is_enabled(struct clk
*clk
)
537 * .is_enabled is only mandatory for clocks that gate
538 * fall back to software usage counter if .is_enabled is missing
540 if (!clk
->ops
->is_enabled
) {
541 ret
= clk
->enable_count
? 1 : 0;
545 ret
= clk
->ops
->is_enabled(clk
->hw
);
550 static struct clk
*__clk_lookup_subtree(const char *name
, struct clk
*clk
)
555 if (!strcmp(clk
->name
, name
))
558 hlist_for_each_entry(child
, &clk
->children
, child_node
) {
559 ret
= __clk_lookup_subtree(name
, child
);
567 struct clk
*__clk_lookup(const char *name
)
569 struct clk
*root_clk
;
575 /* search the 'proper' clk tree first */
576 hlist_for_each_entry(root_clk
, &clk_root_list
, child_node
) {
577 ret
= __clk_lookup_subtree(name
, root_clk
);
582 /* if not found, then search the orphan tree */
583 hlist_for_each_entry(root_clk
, &clk_orphan_list
, child_node
) {
584 ret
= __clk_lookup_subtree(name
, root_clk
);
594 void __clk_unprepare(struct clk
*clk
)
599 if (WARN_ON(clk
->prepare_count
== 0))
602 if (--clk
->prepare_count
> 0)
605 WARN_ON(clk
->enable_count
> 0);
607 if (clk
->ops
->unprepare
)
608 clk
->ops
->unprepare(clk
->hw
);
610 __clk_unprepare(clk
->parent
);
614 * clk_unprepare - undo preparation of a clock source
615 * @clk: the clk being unprepare
617 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
618 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
619 * if the operation may sleep. One example is a clk which is accessed over
620 * I2c. In the complex case a clk gate operation may require a fast and a slow
621 * part. It is this reason that clk_unprepare and clk_disable are not mutually
622 * exclusive. In fact clk_disable must be called before clk_unprepare.
624 void clk_unprepare(struct clk
*clk
)
627 __clk_unprepare(clk
);
628 clk_prepare_unlock();
630 EXPORT_SYMBOL_GPL(clk_unprepare
);
632 int __clk_prepare(struct clk
*clk
)
639 if (clk
->prepare_count
== 0) {
640 ret
= __clk_prepare(clk
->parent
);
644 if (clk
->ops
->prepare
) {
645 ret
= clk
->ops
->prepare(clk
->hw
);
647 __clk_unprepare(clk
->parent
);
653 clk
->prepare_count
++;
659 * clk_prepare - prepare a clock source
660 * @clk: the clk being prepared
662 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
663 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
664 * operation may sleep. One example is a clk which is accessed over I2c. In
665 * the complex case a clk ungate operation may require a fast and a slow part.
666 * It is this reason that clk_prepare and clk_enable are not mutually
667 * exclusive. In fact clk_prepare must be called before clk_enable.
668 * Returns 0 on success, -EERROR otherwise.
670 int clk_prepare(struct clk
*clk
)
675 ret
= __clk_prepare(clk
);
676 clk_prepare_unlock();
680 EXPORT_SYMBOL_GPL(clk_prepare
);
682 static void __clk_disable(struct clk
*clk
)
687 if (WARN_ON(IS_ERR(clk
)))
690 if (WARN_ON(clk
->enable_count
== 0))
693 if (--clk
->enable_count
> 0)
696 if (clk
->ops
->disable
)
697 clk
->ops
->disable(clk
->hw
);
699 __clk_disable(clk
->parent
);
703 * clk_disable - gate a clock
704 * @clk: the clk being gated
706 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
707 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
708 * clk if the operation is fast and will never sleep. One example is a
709 * SoC-internal clk which is controlled via simple register writes. In the
710 * complex case a clk gate operation may require a fast and a slow part. It is
711 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
712 * In fact clk_disable must be called before clk_unprepare.
714 void clk_disable(struct clk
*clk
)
718 flags
= clk_enable_lock();
720 clk_enable_unlock(flags
);
722 EXPORT_SYMBOL_GPL(clk_disable
);
724 static int __clk_enable(struct clk
*clk
)
731 if (WARN_ON(clk
->prepare_count
== 0))
734 if (clk
->enable_count
== 0) {
735 ret
= __clk_enable(clk
->parent
);
740 if (clk
->ops
->enable
) {
741 ret
= clk
->ops
->enable(clk
->hw
);
743 __clk_disable(clk
->parent
);
754 * clk_enable - ungate a clock
755 * @clk: the clk being ungated
757 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
758 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
759 * if the operation will never sleep. One example is a SoC-internal clk which
760 * is controlled via simple register writes. In the complex case a clk ungate
761 * operation may require a fast and a slow part. It is this reason that
762 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
763 * must be called before clk_enable. Returns 0 on success, -EERROR
766 int clk_enable(struct clk
*clk
)
771 flags
= clk_enable_lock();
772 ret
= __clk_enable(clk
);
773 clk_enable_unlock(flags
);
777 EXPORT_SYMBOL_GPL(clk_enable
);
780 * __clk_round_rate - round the given rate for a clk
781 * @clk: round the rate of this clock
783 * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate
785 unsigned long __clk_round_rate(struct clk
*clk
, unsigned long rate
)
787 unsigned long parent_rate
= 0;
792 if (!clk
->ops
->round_rate
) {
793 if (clk
->flags
& CLK_SET_RATE_PARENT
)
794 return __clk_round_rate(clk
->parent
, rate
);
800 parent_rate
= clk
->parent
->rate
;
802 return clk
->ops
->round_rate(clk
->hw
, rate
, &parent_rate
);
806 * clk_round_rate - round the given rate for a clk
807 * @clk: the clk for which we are rounding a rate
808 * @rate: the rate which is to be rounded
810 * Takes in a rate as input and rounds it to a rate that the clk can actually
811 * use which is then returned. If clk doesn't support round_rate operation
812 * then the parent rate is returned.
814 long clk_round_rate(struct clk
*clk
, unsigned long rate
)
819 ret
= __clk_round_rate(clk
, rate
);
820 clk_prepare_unlock();
824 EXPORT_SYMBOL_GPL(clk_round_rate
);
827 * __clk_notify - call clk notifier chain
828 * @clk: struct clk * that is changing rate
829 * @msg: clk notifier type (see include/linux/clk.h)
830 * @old_rate: old clk rate
831 * @new_rate: new clk rate
833 * Triggers a notifier call chain on the clk rate-change notification
834 * for 'clk'. Passes a pointer to the struct clk and the previous
835 * and current rates to the notifier callback. Intended to be called by
836 * internal clock code only. Returns NOTIFY_DONE from the last driver
837 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
838 * a driver returns that.
840 static int __clk_notify(struct clk
*clk
, unsigned long msg
,
841 unsigned long old_rate
, unsigned long new_rate
)
843 struct clk_notifier
*cn
;
844 struct clk_notifier_data cnd
;
845 int ret
= NOTIFY_DONE
;
848 cnd
.old_rate
= old_rate
;
849 cnd
.new_rate
= new_rate
;
851 list_for_each_entry(cn
, &clk_notifier_list
, node
) {
852 if (cn
->clk
== clk
) {
853 ret
= srcu_notifier_call_chain(&cn
->notifier_head
, msg
,
864 * @clk: first clk in the subtree
865 * @msg: notification type (see include/linux/clk.h)
867 * Walks the subtree of clks starting with clk and recalculates rates as it
868 * goes. Note that if a clk does not implement the .recalc_rate callback then
869 * it is assumed that the clock will take on the rate of it's parent.
871 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
874 * Caller must hold prepare_lock.
876 static void __clk_recalc_rates(struct clk
*clk
, unsigned long msg
)
878 unsigned long old_rate
;
879 unsigned long parent_rate
= 0;
882 old_rate
= clk
->rate
;
885 parent_rate
= clk
->parent
->rate
;
887 if (clk
->ops
->recalc_rate
)
888 clk
->rate
= clk
->ops
->recalc_rate(clk
->hw
, parent_rate
);
890 clk
->rate
= parent_rate
;
893 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
894 * & ABORT_RATE_CHANGE notifiers
896 if (clk
->notifier_count
&& msg
)
897 __clk_notify(clk
, msg
, old_rate
, clk
->rate
);
899 hlist_for_each_entry(child
, &clk
->children
, child_node
)
900 __clk_recalc_rates(child
, msg
);
904 * clk_get_rate - return the rate of clk
905 * @clk: the clk whose rate is being returned
907 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
908 * is set, which means a recalc_rate will be issued.
909 * If clk is NULL then returns 0.
911 unsigned long clk_get_rate(struct clk
*clk
)
917 if (clk
&& (clk
->flags
& CLK_GET_RATE_NOCACHE
))
918 __clk_recalc_rates(clk
, 0);
920 rate
= __clk_get_rate(clk
);
921 clk_prepare_unlock();
925 EXPORT_SYMBOL_GPL(clk_get_rate
);
928 * __clk_speculate_rates
929 * @clk: first clk in the subtree
930 * @parent_rate: the "future" rate of clk's parent
932 * Walks the subtree of clks starting with clk, speculating rates as it
933 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
935 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
936 * pre-rate change notifications and returns early if no clks in the
937 * subtree have subscribed to the notifications. Note that if a clk does not
938 * implement the .recalc_rate callback then it is assumed that the clock will
939 * take on the rate of it's parent.
941 * Caller must hold prepare_lock.
943 static int __clk_speculate_rates(struct clk
*clk
, unsigned long parent_rate
)
946 unsigned long new_rate
;
947 int ret
= NOTIFY_DONE
;
949 if (clk
->ops
->recalc_rate
)
950 new_rate
= clk
->ops
->recalc_rate(clk
->hw
, parent_rate
);
952 new_rate
= parent_rate
;
954 /* abort the rate change if a driver returns NOTIFY_BAD */
955 if (clk
->notifier_count
)
956 ret
= __clk_notify(clk
, PRE_RATE_CHANGE
, clk
->rate
, new_rate
);
958 if (ret
== NOTIFY_BAD
)
961 hlist_for_each_entry(child
, &clk
->children
, child_node
) {
962 ret
= __clk_speculate_rates(child
, new_rate
);
963 if (ret
== NOTIFY_BAD
)
971 static void clk_calc_subtree(struct clk
*clk
, unsigned long new_rate
)
975 clk
->new_rate
= new_rate
;
977 hlist_for_each_entry(child
, &clk
->children
, child_node
) {
978 if (child
->ops
->recalc_rate
)
979 child
->new_rate
= child
->ops
->recalc_rate(child
->hw
, new_rate
);
981 child
->new_rate
= new_rate
;
982 clk_calc_subtree(child
, child
->new_rate
);
987 * calculate the new rates returning the topmost clock that has to be
990 static struct clk
*clk_calc_new_rates(struct clk
*clk
, unsigned long rate
)
992 struct clk
*top
= clk
;
993 unsigned long best_parent_rate
= 0;
994 unsigned long new_rate
;
997 if (IS_ERR_OR_NULL(clk
))
1000 /* save parent rate, if it exists */
1002 best_parent_rate
= clk
->parent
->rate
;
1004 /* never propagate up to the parent */
1005 if (!(clk
->flags
& CLK_SET_RATE_PARENT
)) {
1006 if (!clk
->ops
->round_rate
) {
1007 clk
->new_rate
= clk
->rate
;
1010 new_rate
= clk
->ops
->round_rate(clk
->hw
, rate
, &best_parent_rate
);
1014 /* need clk->parent from here on out */
1016 pr_debug("%s: %s has NULL parent\n", __func__
, clk
->name
);
1020 if (!clk
->ops
->round_rate
) {
1021 top
= clk_calc_new_rates(clk
->parent
, rate
);
1022 new_rate
= clk
->parent
->new_rate
;
1027 new_rate
= clk
->ops
->round_rate(clk
->hw
, rate
, &best_parent_rate
);
1029 if (best_parent_rate
!= clk
->parent
->rate
) {
1030 top
= clk_calc_new_rates(clk
->parent
, best_parent_rate
);
1036 clk_calc_subtree(clk
, new_rate
);
1042 * Notify about rate changes in a subtree. Always walk down the whole tree
1043 * so that in case of an error we can walk down the whole tree again and
1046 static struct clk
*clk_propagate_rate_change(struct clk
*clk
, unsigned long event
)
1048 struct clk
*child
, *fail_clk
= NULL
;
1049 int ret
= NOTIFY_DONE
;
1051 if (clk
->rate
== clk
->new_rate
)
1054 if (clk
->notifier_count
) {
1055 ret
= __clk_notify(clk
, event
, clk
->rate
, clk
->new_rate
);
1056 if (ret
== NOTIFY_BAD
)
1060 hlist_for_each_entry(child
, &clk
->children
, child_node
) {
1061 clk
= clk_propagate_rate_change(child
, event
);
1070 * walk down a subtree and set the new rates notifying the rate
1073 static void clk_change_rate(struct clk
*clk
)
1076 unsigned long old_rate
;
1077 unsigned long best_parent_rate
= 0;
1079 old_rate
= clk
->rate
;
1082 best_parent_rate
= clk
->parent
->rate
;
1084 if (clk
->ops
->set_rate
)
1085 clk
->ops
->set_rate(clk
->hw
, clk
->new_rate
, best_parent_rate
);
1087 if (clk
->ops
->recalc_rate
)
1088 clk
->rate
= clk
->ops
->recalc_rate(clk
->hw
, best_parent_rate
);
1090 clk
->rate
= best_parent_rate
;
1092 if (clk
->notifier_count
&& old_rate
!= clk
->rate
)
1093 __clk_notify(clk
, POST_RATE_CHANGE
, old_rate
, clk
->rate
);
1095 hlist_for_each_entry(child
, &clk
->children
, child_node
)
1096 clk_change_rate(child
);
1100 * clk_set_rate - specify a new rate for clk
1101 * @clk: the clk whose rate is being changed
1102 * @rate: the new rate for clk
1104 * In the simplest case clk_set_rate will only adjust the rate of clk.
1106 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1107 * propagate up to clk's parent; whether or not this happens depends on the
1108 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1109 * after calling .round_rate then upstream parent propagation is ignored. If
1110 * *parent_rate comes back with a new rate for clk's parent then we propagate
1111 * up to clk's parent and set it's rate. Upward propagation will continue
1112 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1113 * .round_rate stops requesting changes to clk's parent_rate.
1115 * Rate changes are accomplished via tree traversal that also recalculates the
1116 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1118 * Returns 0 on success, -EERROR otherwise.
1120 int clk_set_rate(struct clk
*clk
, unsigned long rate
)
1122 struct clk
*top
, *fail_clk
;
1125 /* prevent racing with updates to the clock topology */
1128 /* bail early if nothing to do */
1129 if (rate
== clk
->rate
)
1132 if ((clk
->flags
& CLK_SET_RATE_GATE
) && clk
->prepare_count
) {
1137 /* calculate new rates and get the topmost changed clock */
1138 top
= clk_calc_new_rates(clk
, rate
);
1144 /* notify that we are about to change rates */
1145 fail_clk
= clk_propagate_rate_change(top
, PRE_RATE_CHANGE
);
1147 pr_warn("%s: failed to set %s rate\n", __func__
,
1149 clk_propagate_rate_change(top
, ABORT_RATE_CHANGE
);
1154 /* change the rates */
1155 clk_change_rate(top
);
1158 clk_prepare_unlock();
1162 EXPORT_SYMBOL_GPL(clk_set_rate
);
1165 * clk_get_parent - return the parent of a clk
1166 * @clk: the clk whose parent gets returned
1168 * Simply returns clk->parent. Returns NULL if clk is NULL.
1170 struct clk
*clk_get_parent(struct clk
*clk
)
1175 parent
= __clk_get_parent(clk
);
1176 clk_prepare_unlock();
1180 EXPORT_SYMBOL_GPL(clk_get_parent
);
1183 * .get_parent is mandatory for clocks with multiple possible parents. It is
1184 * optional for single-parent clocks. Always call .get_parent if it is
1185 * available and WARN if it is missing for multi-parent clocks.
1187 * For single-parent clocks without .get_parent, first check to see if the
1188 * .parents array exists, and if so use it to avoid an expensive tree
1189 * traversal. If .parents does not exist then walk the tree with __clk_lookup.
1191 static struct clk
*__clk_init_parent(struct clk
*clk
)
1193 struct clk
*ret
= NULL
;
1196 /* handle the trivial cases */
1198 if (!clk
->num_parents
)
1201 if (clk
->num_parents
== 1) {
1202 if (IS_ERR_OR_NULL(clk
->parent
))
1203 ret
= clk
->parent
= __clk_lookup(clk
->parent_names
[0]);
1208 if (!clk
->ops
->get_parent
) {
1209 WARN(!clk
->ops
->get_parent
,
1210 "%s: multi-parent clocks must implement .get_parent\n",
1216 * Do our best to cache parent clocks in clk->parents. This prevents
1217 * unnecessary and expensive calls to __clk_lookup. We don't set
1218 * clk->parent here; that is done by the calling function
1221 index
= clk
->ops
->get_parent(clk
->hw
);
1225 kzalloc((sizeof(struct clk
*) * clk
->num_parents
),
1229 ret
= __clk_lookup(clk
->parent_names
[index
]);
1230 else if (!clk
->parents
[index
])
1231 ret
= clk
->parents
[index
] =
1232 __clk_lookup(clk
->parent_names
[index
]);
1234 ret
= clk
->parents
[index
];
1240 void __clk_reparent(struct clk
*clk
, struct clk
*new_parent
)
1242 #ifdef CONFIG_COMMON_CLK_DEBUG
1244 struct dentry
*new_parent_d
;
1247 if (!clk
|| !new_parent
)
1250 hlist_del(&clk
->child_node
);
1253 hlist_add_head(&clk
->child_node
, &new_parent
->children
);
1255 hlist_add_head(&clk
->child_node
, &clk_orphan_list
);
1257 #ifdef CONFIG_COMMON_CLK_DEBUG
1262 new_parent_d
= new_parent
->dentry
;
1264 new_parent_d
= orphandir
;
1266 d
= debugfs_rename(clk
->dentry
->d_parent
, clk
->dentry
,
1267 new_parent_d
, clk
->name
);
1271 pr_debug("%s: failed to rename debugfs entry for %s\n",
1272 __func__
, clk
->name
);
1276 clk
->parent
= new_parent
;
1278 __clk_recalc_rates(clk
, POST_RATE_CHANGE
);
1281 static int __clk_set_parent(struct clk
*clk
, struct clk
*parent
)
1283 struct clk
*old_parent
;
1284 unsigned long flags
;
1288 old_parent
= clk
->parent
;
1291 clk
->parents
= kzalloc((sizeof(struct clk
*) * clk
->num_parents
),
1295 * find index of new parent clock using cached parent ptrs,
1296 * or if not yet cached, use string name comparison and cache
1297 * them now to avoid future calls to __clk_lookup.
1299 for (i
= 0; i
< clk
->num_parents
; i
++) {
1300 if (clk
->parents
&& clk
->parents
[i
] == parent
)
1302 else if (!strcmp(clk
->parent_names
[i
], parent
->name
)) {
1304 clk
->parents
[i
] = __clk_lookup(parent
->name
);
1309 if (i
== clk
->num_parents
) {
1310 pr_debug("%s: clock %s is not a possible parent of clock %s\n",
1311 __func__
, parent
->name
, clk
->name
);
1315 /* migrate prepare and enable */
1316 if (clk
->prepare_count
)
1317 __clk_prepare(parent
);
1319 /* FIXME replace with clk_is_enabled(clk) someday */
1320 flags
= clk_enable_lock();
1321 if (clk
->enable_count
)
1322 __clk_enable(parent
);
1323 clk_enable_unlock(flags
);
1325 /* change clock input source */
1326 ret
= clk
->ops
->set_parent(clk
->hw
, i
);
1328 /* clean up old prepare and enable */
1329 flags
= clk_enable_lock();
1330 if (clk
->enable_count
)
1331 __clk_disable(old_parent
);
1332 clk_enable_unlock(flags
);
1334 if (clk
->prepare_count
)
1335 __clk_unprepare(old_parent
);
1342 * clk_set_parent - switch the parent of a mux clk
1343 * @clk: the mux clk whose input we are switching
1344 * @parent: the new input to clk
1346 * Re-parent clk to use parent as it's new input source. If clk has the
1347 * CLK_SET_PARENT_GATE flag set then clk must be gated for this
1348 * operation to succeed. After successfully changing clk's parent
1349 * clk_set_parent will update the clk topology, sysfs topology and
1350 * propagate rate recalculation via __clk_recalc_rates. Returns 0 on
1351 * success, -EERROR otherwise.
1353 int clk_set_parent(struct clk
*clk
, struct clk
*parent
)
1357 if (!clk
|| !clk
->ops
)
1360 if (!clk
->ops
->set_parent
)
1363 /* prevent racing with updates to the clock topology */
1366 if (clk
->parent
== parent
)
1369 /* propagate PRE_RATE_CHANGE notifications */
1370 if (clk
->notifier_count
)
1371 ret
= __clk_speculate_rates(clk
, parent
->rate
);
1373 /* abort if a driver objects */
1374 if (ret
== NOTIFY_STOP
)
1377 /* only re-parent if the clock is not in use */
1378 if ((clk
->flags
& CLK_SET_PARENT_GATE
) && clk
->prepare_count
)
1381 ret
= __clk_set_parent(clk
, parent
);
1383 /* propagate ABORT_RATE_CHANGE if .set_parent failed */
1385 __clk_recalc_rates(clk
, ABORT_RATE_CHANGE
);
1389 /* propagate rate recalculation downstream */
1390 __clk_reparent(clk
, parent
);
1393 clk_prepare_unlock();
1397 EXPORT_SYMBOL_GPL(clk_set_parent
);
1400 * __clk_init - initialize the data structures in a struct clk
1401 * @dev: device initializing this clk, placeholder for now
1402 * @clk: clk being initialized
1404 * Initializes the lists in struct clk, queries the hardware for the
1405 * parent and rate and sets them both.
1407 int __clk_init(struct device
*dev
, struct clk
*clk
)
1411 struct hlist_node
*tmp2
;
1418 /* check to see if a clock with this name is already registered */
1419 if (__clk_lookup(clk
->name
)) {
1420 pr_debug("%s: clk %s already initialized\n",
1421 __func__
, clk
->name
);
1426 /* check that clk_ops are sane. See Documentation/clk.txt */
1427 if (clk
->ops
->set_rate
&&
1428 !(clk
->ops
->round_rate
&& clk
->ops
->recalc_rate
)) {
1429 pr_warning("%s: %s must implement .round_rate & .recalc_rate\n",
1430 __func__
, clk
->name
);
1435 if (clk
->ops
->set_parent
&& !clk
->ops
->get_parent
) {
1436 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
1437 __func__
, clk
->name
);
1442 /* throw a WARN if any entries in parent_names are NULL */
1443 for (i
= 0; i
< clk
->num_parents
; i
++)
1444 WARN(!clk
->parent_names
[i
],
1445 "%s: invalid NULL in %s's .parent_names\n",
1446 __func__
, clk
->name
);
1449 * Allocate an array of struct clk *'s to avoid unnecessary string
1450 * look-ups of clk's possible parents. This can fail for clocks passed
1451 * in to clk_init during early boot; thus any access to clk->parents[]
1452 * must always check for a NULL pointer and try to populate it if
1455 * If clk->parents is not NULL we skip this entire block. This allows
1456 * for clock drivers to statically initialize clk->parents.
1458 if (clk
->num_parents
> 1 && !clk
->parents
) {
1459 clk
->parents
= kzalloc((sizeof(struct clk
*) * clk
->num_parents
),
1462 * __clk_lookup returns NULL for parents that have not been
1463 * clk_init'd; thus any access to clk->parents[] must check
1464 * for a NULL pointer. We can always perform lazy lookups for
1465 * missing parents later on.
1468 for (i
= 0; i
< clk
->num_parents
; i
++)
1470 __clk_lookup(clk
->parent_names
[i
]);
1473 clk
->parent
= __clk_init_parent(clk
);
1476 * Populate clk->parent if parent has already been __clk_init'd. If
1477 * parent has not yet been __clk_init'd then place clk in the orphan
1478 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
1481 * Every time a new clk is clk_init'd then we walk the list of orphan
1482 * clocks and re-parent any that are children of the clock currently
1486 hlist_add_head(&clk
->child_node
,
1487 &clk
->parent
->children
);
1488 else if (clk
->flags
& CLK_IS_ROOT
)
1489 hlist_add_head(&clk
->child_node
, &clk_root_list
);
1491 hlist_add_head(&clk
->child_node
, &clk_orphan_list
);
1494 * Set clk's rate. The preferred method is to use .recalc_rate. For
1495 * simple clocks and lazy developers the default fallback is to use the
1496 * parent's rate. If a clock doesn't have a parent (or is orphaned)
1497 * then rate is set to zero.
1499 if (clk
->ops
->recalc_rate
)
1500 clk
->rate
= clk
->ops
->recalc_rate(clk
->hw
,
1501 __clk_get_rate(clk
->parent
));
1502 else if (clk
->parent
)
1503 clk
->rate
= clk
->parent
->rate
;
1508 * walk the list of orphan clocks and reparent any that are children of
1511 hlist_for_each_entry_safe(orphan
, tmp2
, &clk_orphan_list
, child_node
) {
1512 if (orphan
->ops
->get_parent
) {
1513 i
= orphan
->ops
->get_parent(orphan
->hw
);
1514 if (!strcmp(clk
->name
, orphan
->parent_names
[i
]))
1515 __clk_reparent(orphan
, clk
);
1519 for (i
= 0; i
< orphan
->num_parents
; i
++)
1520 if (!strcmp(clk
->name
, orphan
->parent_names
[i
])) {
1521 __clk_reparent(orphan
, clk
);
1527 * optional platform-specific magic
1529 * The .init callback is not used by any of the basic clock types, but
1530 * exists for weird hardware that must perform initialization magic.
1531 * Please consider other ways of solving initialization problems before
1532 * using this callback, as it's use is discouraged.
1535 clk
->ops
->init(clk
->hw
);
1537 clk_debug_register(clk
);
1540 clk_prepare_unlock();
1546 * __clk_register - register a clock and return a cookie.
1548 * Same as clk_register, except that the .clk field inside hw shall point to a
1549 * preallocated (generally statically allocated) struct clk. None of the fields
1550 * of the struct clk need to be initialized.
1552 * The data pointed to by .init and .clk field shall NOT be marked as init
1555 * __clk_register is only exposed via clk-private.h and is intended for use with
1556 * very large numbers of clocks that need to be statically initialized. It is
1557 * a layering violation to include clk-private.h from any code which implements
1558 * a clock's .ops; as such any statically initialized clock data MUST be in a
1559 * separate C file from the logic that implements it's operations. Returns 0
1560 * on success, otherwise an error code.
1562 struct clk
*__clk_register(struct device
*dev
, struct clk_hw
*hw
)
1568 clk
->name
= hw
->init
->name
;
1569 clk
->ops
= hw
->init
->ops
;
1571 clk
->flags
= hw
->init
->flags
;
1572 clk
->parent_names
= hw
->init
->parent_names
;
1573 clk
->num_parents
= hw
->init
->num_parents
;
1575 ret
= __clk_init(dev
, clk
);
1577 return ERR_PTR(ret
);
1581 EXPORT_SYMBOL_GPL(__clk_register
);
1583 static int _clk_register(struct device
*dev
, struct clk_hw
*hw
, struct clk
*clk
)
1587 clk
->name
= kstrdup(hw
->init
->name
, GFP_KERNEL
);
1589 pr_err("%s: could not allocate clk->name\n", __func__
);
1593 clk
->ops
= hw
->init
->ops
;
1595 clk
->flags
= hw
->init
->flags
;
1596 clk
->num_parents
= hw
->init
->num_parents
;
1599 /* allocate local copy in case parent_names is __initdata */
1600 clk
->parent_names
= kzalloc((sizeof(char*) * clk
->num_parents
),
1603 if (!clk
->parent_names
) {
1604 pr_err("%s: could not allocate clk->parent_names\n", __func__
);
1606 goto fail_parent_names
;
1610 /* copy each string name in case parent_names is __initdata */
1611 for (i
= 0; i
< clk
->num_parents
; i
++) {
1612 clk
->parent_names
[i
] = kstrdup(hw
->init
->parent_names
[i
],
1614 if (!clk
->parent_names
[i
]) {
1615 pr_err("%s: could not copy parent_names\n", __func__
);
1617 goto fail_parent_names_copy
;
1621 ret
= __clk_init(dev
, clk
);
1625 fail_parent_names_copy
:
1627 kfree(clk
->parent_names
[i
]);
1628 kfree(clk
->parent_names
);
1636 * clk_register - allocate a new clock, register it and return an opaque cookie
1637 * @dev: device that is registering this clock
1638 * @hw: link to hardware-specific clock data
1640 * clk_register is the primary interface for populating the clock tree with new
1641 * clock nodes. It returns a pointer to the newly allocated struct clk which
1642 * cannot be dereferenced by driver code but may be used in conjuction with the
1643 * rest of the clock API. In the event of an error clk_register will return an
1644 * error code; drivers must test for an error code after calling clk_register.
1646 struct clk
*clk_register(struct device
*dev
, struct clk_hw
*hw
)
1651 clk
= kzalloc(sizeof(*clk
), GFP_KERNEL
);
1653 pr_err("%s: could not allocate clk\n", __func__
);
1658 ret
= _clk_register(dev
, hw
, clk
);
1664 return ERR_PTR(ret
);
1666 EXPORT_SYMBOL_GPL(clk_register
);
1669 * clk_unregister - unregister a currently registered clock
1670 * @clk: clock to unregister
1672 * Currently unimplemented.
1674 void clk_unregister(struct clk
*clk
) {}
1675 EXPORT_SYMBOL_GPL(clk_unregister
);
1677 static void devm_clk_release(struct device
*dev
, void *res
)
1679 clk_unregister(res
);
1683 * devm_clk_register - resource managed clk_register()
1684 * @dev: device that is registering this clock
1685 * @hw: link to hardware-specific clock data
1687 * Managed clk_register(). Clocks returned from this function are
1688 * automatically clk_unregister()ed on driver detach. See clk_register() for
1691 struct clk
*devm_clk_register(struct device
*dev
, struct clk_hw
*hw
)
1696 clk
= devres_alloc(devm_clk_release
, sizeof(*clk
), GFP_KERNEL
);
1698 return ERR_PTR(-ENOMEM
);
1700 ret
= _clk_register(dev
, hw
, clk
);
1702 devres_add(dev
, clk
);
1710 EXPORT_SYMBOL_GPL(devm_clk_register
);
1712 static int devm_clk_match(struct device
*dev
, void *res
, void *data
)
1714 struct clk
*c
= res
;
1721 * devm_clk_unregister - resource managed clk_unregister()
1722 * @clk: clock to unregister
1724 * Deallocate a clock allocated with devm_clk_register(). Normally
1725 * this function will not need to be called and the resource management
1726 * code will ensure that the resource is freed.
1728 void devm_clk_unregister(struct device
*dev
, struct clk
*clk
)
1730 WARN_ON(devres_release(dev
, devm_clk_release
, devm_clk_match
, clk
));
1732 EXPORT_SYMBOL_GPL(devm_clk_unregister
);
1734 /*** clk rate change notifiers ***/
1737 * clk_notifier_register - add a clk rate change notifier
1738 * @clk: struct clk * to watch
1739 * @nb: struct notifier_block * with callback info
1741 * Request notification when clk's rate changes. This uses an SRCU
1742 * notifier because we want it to block and notifier unregistrations are
1743 * uncommon. The callbacks associated with the notifier must not
1744 * re-enter into the clk framework by calling any top-level clk APIs;
1745 * this will cause a nested prepare_lock mutex.
1747 * Pre-change notifier callbacks will be passed the current, pre-change
1748 * rate of the clk via struct clk_notifier_data.old_rate. The new,
1749 * post-change rate of the clk is passed via struct
1750 * clk_notifier_data.new_rate.
1752 * Post-change notifiers will pass the now-current, post-change rate of
1753 * the clk in both struct clk_notifier_data.old_rate and struct
1754 * clk_notifier_data.new_rate.
1756 * Abort-change notifiers are effectively the opposite of pre-change
1757 * notifiers: the original pre-change clk rate is passed in via struct
1758 * clk_notifier_data.new_rate and the failed post-change rate is passed
1759 * in via struct clk_notifier_data.old_rate.
1761 * clk_notifier_register() must be called from non-atomic context.
1762 * Returns -EINVAL if called with null arguments, -ENOMEM upon
1763 * allocation failure; otherwise, passes along the return value of
1764 * srcu_notifier_chain_register().
1766 int clk_notifier_register(struct clk
*clk
, struct notifier_block
*nb
)
1768 struct clk_notifier
*cn
;
1776 /* search the list of notifiers for this clk */
1777 list_for_each_entry(cn
, &clk_notifier_list
, node
)
1781 /* if clk wasn't in the notifier list, allocate new clk_notifier */
1782 if (cn
->clk
!= clk
) {
1783 cn
= kzalloc(sizeof(struct clk_notifier
), GFP_KERNEL
);
1788 srcu_init_notifier_head(&cn
->notifier_head
);
1790 list_add(&cn
->node
, &clk_notifier_list
);
1793 ret
= srcu_notifier_chain_register(&cn
->notifier_head
, nb
);
1795 clk
->notifier_count
++;
1798 clk_prepare_unlock();
1802 EXPORT_SYMBOL_GPL(clk_notifier_register
);
1805 * clk_notifier_unregister - remove a clk rate change notifier
1806 * @clk: struct clk *
1807 * @nb: struct notifier_block * with callback info
1809 * Request no further notification for changes to 'clk' and frees memory
1810 * allocated in clk_notifier_register.
1812 * Returns -EINVAL if called with null arguments; otherwise, passes
1813 * along the return value of srcu_notifier_chain_unregister().
1815 int clk_notifier_unregister(struct clk
*clk
, struct notifier_block
*nb
)
1817 struct clk_notifier
*cn
= NULL
;
1825 list_for_each_entry(cn
, &clk_notifier_list
, node
)
1829 if (cn
->clk
== clk
) {
1830 ret
= srcu_notifier_chain_unregister(&cn
->notifier_head
, nb
);
1832 clk
->notifier_count
--;
1834 /* XXX the notifier code should handle this better */
1835 if (!cn
->notifier_head
.head
) {
1836 srcu_cleanup_notifier_head(&cn
->notifier_head
);
1844 clk_prepare_unlock();
1848 EXPORT_SYMBOL_GPL(clk_notifier_unregister
);
1852 * struct of_clk_provider - Clock provider registration structure
1853 * @link: Entry in global list of clock providers
1854 * @node: Pointer to device tree node of clock provider
1855 * @get: Get clock callback. Returns NULL or a struct clk for the
1856 * given clock specifier
1857 * @data: context pointer to be passed into @get callback
1859 struct of_clk_provider
{
1860 struct list_head link
;
1862 struct device_node
*node
;
1863 struct clk
*(*get
)(struct of_phandle_args
*clkspec
, void *data
);
1867 extern struct of_device_id __clk_of_table
[];
1869 static const struct of_device_id __clk_of_table_sentinel
1870 __used
__section(__clk_of_table_end
);
1872 static LIST_HEAD(of_clk_providers
);
1873 static DEFINE_MUTEX(of_clk_lock
);
1875 struct clk
*of_clk_src_simple_get(struct of_phandle_args
*clkspec
,
1880 EXPORT_SYMBOL_GPL(of_clk_src_simple_get
);
1882 struct clk
*of_clk_src_onecell_get(struct of_phandle_args
*clkspec
, void *data
)
1884 struct clk_onecell_data
*clk_data
= data
;
1885 unsigned int idx
= clkspec
->args
[0];
1887 if (idx
>= clk_data
->clk_num
) {
1888 pr_err("%s: invalid clock index %d\n", __func__
, idx
);
1889 return ERR_PTR(-EINVAL
);
1892 return clk_data
->clks
[idx
];
1894 EXPORT_SYMBOL_GPL(of_clk_src_onecell_get
);
1897 * of_clk_add_provider() - Register a clock provider for a node
1898 * @np: Device node pointer associated with clock provider
1899 * @clk_src_get: callback for decoding clock
1900 * @data: context pointer for @clk_src_get callback.
1902 int of_clk_add_provider(struct device_node
*np
,
1903 struct clk
*(*clk_src_get
)(struct of_phandle_args
*clkspec
,
1907 struct of_clk_provider
*cp
;
1909 cp
= kzalloc(sizeof(struct of_clk_provider
), GFP_KERNEL
);
1913 cp
->node
= of_node_get(np
);
1915 cp
->get
= clk_src_get
;
1917 mutex_lock(&of_clk_lock
);
1918 list_add(&cp
->link
, &of_clk_providers
);
1919 mutex_unlock(&of_clk_lock
);
1920 pr_debug("Added clock from %s\n", np
->full_name
);
1924 EXPORT_SYMBOL_GPL(of_clk_add_provider
);
1927 * of_clk_del_provider() - Remove a previously registered clock provider
1928 * @np: Device node pointer associated with clock provider
1930 void of_clk_del_provider(struct device_node
*np
)
1932 struct of_clk_provider
*cp
;
1934 mutex_lock(&of_clk_lock
);
1935 list_for_each_entry(cp
, &of_clk_providers
, link
) {
1936 if (cp
->node
== np
) {
1937 list_del(&cp
->link
);
1938 of_node_put(cp
->node
);
1943 mutex_unlock(&of_clk_lock
);
1945 EXPORT_SYMBOL_GPL(of_clk_del_provider
);
1947 struct clk
*of_clk_get_from_provider(struct of_phandle_args
*clkspec
)
1949 struct of_clk_provider
*provider
;
1950 struct clk
*clk
= ERR_PTR(-ENOENT
);
1952 /* Check if we have such a provider in our array */
1953 mutex_lock(&of_clk_lock
);
1954 list_for_each_entry(provider
, &of_clk_providers
, link
) {
1955 if (provider
->node
== clkspec
->np
)
1956 clk
= provider
->get(clkspec
, provider
->data
);
1960 mutex_unlock(&of_clk_lock
);
1965 const char *of_clk_get_parent_name(struct device_node
*np
, int index
)
1967 struct of_phandle_args clkspec
;
1968 const char *clk_name
;
1974 rc
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells", index
,
1979 if (of_property_read_string_index(clkspec
.np
, "clock-output-names",
1980 clkspec
.args_count
? clkspec
.args
[0] : 0,
1982 clk_name
= clkspec
.np
->name
;
1984 of_node_put(clkspec
.np
);
1987 EXPORT_SYMBOL_GPL(of_clk_get_parent_name
);
1990 * of_clk_init() - Scan and init clock providers from the DT
1991 * @matches: array of compatible values and init functions for providers.
1993 * This function scans the device tree for matching clock providers and
1994 * calls their initialization functions
1996 void __init
of_clk_init(const struct of_device_id
*matches
)
1998 struct device_node
*np
;
2001 matches
= __clk_of_table
;
2003 for_each_matching_node(np
, matches
) {
2004 const struct of_device_id
*match
= of_match_node(matches
, np
);
2005 of_clk_init_cb_t clk_init_cb
= match
->data
;