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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
4 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
5 *
6 * Standard functionality for the common clock API. See Documentation/driver-api/clk.rst
7 */
8
9#include <linux/clk.h>
10#include <linux/clk-provider.h>
11#include <linux/clk/clk-conf.h>
12#include <linux/module.h>
13#include <linux/mutex.h>
14#include <linux/spinlock.h>
15#include <linux/err.h>
16#include <linux/list.h>
17#include <linux/slab.h>
18#include <linux/of.h>
19#include <linux/device.h>
20#include <linux/init.h>
21#include <linux/pm_runtime.h>
22#include <linux/sched.h>
23#include <linux/clkdev.h>
24
25#include "clk.h"
26
27static DEFINE_SPINLOCK(enable_lock);
28static DEFINE_MUTEX(prepare_lock);
29
30static struct task_struct *prepare_owner;
31static struct task_struct *enable_owner;
32
33static int prepare_refcnt;
34static int enable_refcnt;
35
36static HLIST_HEAD(clk_root_list);
37static HLIST_HEAD(clk_orphan_list);
38static LIST_HEAD(clk_notifier_list);
39
40static const struct hlist_head *all_lists[] = {
41 &clk_root_list,
42 &clk_orphan_list,
43 NULL,
44};
45
46/*** private data structures ***/
47
48struct clk_parent_map {
49 const struct clk_hw *hw;
50 struct clk_core *core;
51 const char *fw_name;
52 const char *name;
53 int index;
54};
55
56struct clk_core {
57 const char *name;
58 const struct clk_ops *ops;
59 struct clk_hw *hw;
60 struct module *owner;
61 struct device *dev;
62 struct device_node *of_node;
63 struct clk_core *parent;
64 struct clk_parent_map *parents;
65 u8 num_parents;
66 u8 new_parent_index;
67 unsigned long rate;
68 unsigned long req_rate;
69 unsigned long new_rate;
70 struct clk_core *new_parent;
71 struct clk_core *new_child;
72 unsigned long flags;
73 bool orphan;
74 bool rpm_enabled;
75 unsigned int enable_count;
76 unsigned int prepare_count;
77 unsigned int protect_count;
78 unsigned long min_rate;
79 unsigned long max_rate;
80 unsigned long accuracy;
81 int phase;
82 struct clk_duty duty;
83 struct hlist_head children;
84 struct hlist_node child_node;
85 struct hlist_head clks;
86 unsigned int notifier_count;
87#ifdef CONFIG_DEBUG_FS
88 struct dentry *dentry;
89 struct hlist_node debug_node;
90#endif
91 struct kref ref;
92};
93
94#define CREATE_TRACE_POINTS
95#include <trace/events/clk.h>
96
97struct clk {
98 struct clk_core *core;
99 struct device *dev;
100 const char *dev_id;
101 const char *con_id;
102 unsigned long min_rate;
103 unsigned long max_rate;
104 unsigned int exclusive_count;
105 struct hlist_node clks_node;
106};
107
108/*** runtime pm ***/
109static int clk_pm_runtime_get(struct clk_core *core)
110{
111 if (!core->rpm_enabled)
112 return 0;
113
114 return pm_runtime_resume_and_get(core->dev);
115}
116
117static void clk_pm_runtime_put(struct clk_core *core)
118{
119 if (!core->rpm_enabled)
120 return;
121
122 pm_runtime_put_sync(core->dev);
123}
124
125/*** locking ***/
126static void clk_prepare_lock(void)
127{
128 if (!mutex_trylock(&prepare_lock)) {
129 if (prepare_owner == current) {
130 prepare_refcnt++;
131 return;
132 }
133 mutex_lock(&prepare_lock);
134 }
135 WARN_ON_ONCE(prepare_owner != NULL);
136 WARN_ON_ONCE(prepare_refcnt != 0);
137 prepare_owner = current;
138 prepare_refcnt = 1;
139}
140
141static void clk_prepare_unlock(void)
142{
143 WARN_ON_ONCE(prepare_owner != current);
144 WARN_ON_ONCE(prepare_refcnt == 0);
145
146 if (--prepare_refcnt)
147 return;
148 prepare_owner = NULL;
149 mutex_unlock(&prepare_lock);
150}
151
152static unsigned long clk_enable_lock(void)
153 __acquires(enable_lock)
154{
155 unsigned long flags;
156
157 /*
158 * On UP systems, spin_trylock_irqsave() always returns true, even if
159 * we already hold the lock. So, in that case, we rely only on
160 * reference counting.
161 */
162 if (!IS_ENABLED(CONFIG_SMP) ||
163 !spin_trylock_irqsave(&enable_lock, flags)) {
164 if (enable_owner == current) {
165 enable_refcnt++;
166 __acquire(enable_lock);
167 if (!IS_ENABLED(CONFIG_SMP))
168 local_save_flags(flags);
169 return flags;
170 }
171 spin_lock_irqsave(&enable_lock, flags);
172 }
173 WARN_ON_ONCE(enable_owner != NULL);
174 WARN_ON_ONCE(enable_refcnt != 0);
175 enable_owner = current;
176 enable_refcnt = 1;
177 return flags;
178}
179
180static void clk_enable_unlock(unsigned long flags)
181 __releases(enable_lock)
182{
183 WARN_ON_ONCE(enable_owner != current);
184 WARN_ON_ONCE(enable_refcnt == 0);
185
186 if (--enable_refcnt) {
187 __release(enable_lock);
188 return;
189 }
190 enable_owner = NULL;
191 spin_unlock_irqrestore(&enable_lock, flags);
192}
193
194static bool clk_core_rate_is_protected(struct clk_core *core)
195{
196 return core->protect_count;
197}
198
199static bool clk_core_is_prepared(struct clk_core *core)
200{
201 bool ret = false;
202
203 /*
204 * .is_prepared is optional for clocks that can prepare
205 * fall back to software usage counter if it is missing
206 */
207 if (!core->ops->is_prepared)
208 return core->prepare_count;
209
210 if (!clk_pm_runtime_get(core)) {
211 ret = core->ops->is_prepared(core->hw);
212 clk_pm_runtime_put(core);
213 }
214
215 return ret;
216}
217
218static bool clk_core_is_enabled(struct clk_core *core)
219{
220 bool ret = false;
221
222 /*
223 * .is_enabled is only mandatory for clocks that gate
224 * fall back to software usage counter if .is_enabled is missing
225 */
226 if (!core->ops->is_enabled)
227 return core->enable_count;
228
229 /*
230 * Check if clock controller's device is runtime active before
231 * calling .is_enabled callback. If not, assume that clock is
232 * disabled, because we might be called from atomic context, from
233 * which pm_runtime_get() is not allowed.
234 * This function is called mainly from clk_disable_unused_subtree,
235 * which ensures proper runtime pm activation of controller before
236 * taking enable spinlock, but the below check is needed if one tries
237 * to call it from other places.
238 */
239 if (core->rpm_enabled) {
240 pm_runtime_get_noresume(core->dev);
241 if (!pm_runtime_active(core->dev)) {
242 ret = false;
243 goto done;
244 }
245 }
246
247 /*
248 * This could be called with the enable lock held, or from atomic
249 * context. If the parent isn't enabled already, we can't do
250 * anything here. We can also assume this clock isn't enabled.
251 */
252 if ((core->flags & CLK_OPS_PARENT_ENABLE) && core->parent)
253 if (!clk_core_is_enabled(core->parent)) {
254 ret = false;
255 goto done;
256 }
257
258 ret = core->ops->is_enabled(core->hw);
259done:
260 if (core->rpm_enabled)
261 pm_runtime_put(core->dev);
262
263 return ret;
264}
265
266/*** helper functions ***/
267
268const char *__clk_get_name(const struct clk *clk)
269{
270 return !clk ? NULL : clk->core->name;
271}
272EXPORT_SYMBOL_GPL(__clk_get_name);
273
274const char *clk_hw_get_name(const struct clk_hw *hw)
275{
276 return hw->core->name;
277}
278EXPORT_SYMBOL_GPL(clk_hw_get_name);
279
280struct clk_hw *__clk_get_hw(struct clk *clk)
281{
282 return !clk ? NULL : clk->core->hw;
283}
284EXPORT_SYMBOL_GPL(__clk_get_hw);
285
286unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
287{
288 return hw->core->num_parents;
289}
290EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
291
292struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
293{
294 return hw->core->parent ? hw->core->parent->hw : NULL;
295}
296EXPORT_SYMBOL_GPL(clk_hw_get_parent);
297
298static struct clk_core *__clk_lookup_subtree(const char *name,
299 struct clk_core *core)
300{
301 struct clk_core *child;
302 struct clk_core *ret;
303
304 if (!strcmp(core->name, name))
305 return core;
306
307 hlist_for_each_entry(child, &core->children, child_node) {
308 ret = __clk_lookup_subtree(name, child);
309 if (ret)
310 return ret;
311 }
312
313 return NULL;
314}
315
316static struct clk_core *clk_core_lookup(const char *name)
317{
318 struct clk_core *root_clk;
319 struct clk_core *ret;
320
321 if (!name)
322 return NULL;
323
324 /* search the 'proper' clk tree first */
325 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
326 ret = __clk_lookup_subtree(name, root_clk);
327 if (ret)
328 return ret;
329 }
330
331 /* if not found, then search the orphan tree */
332 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
333 ret = __clk_lookup_subtree(name, root_clk);
334 if (ret)
335 return ret;
336 }
337
338 return NULL;
339}
340
341#ifdef CONFIG_OF
342static int of_parse_clkspec(const struct device_node *np, int index,
343 const char *name, struct of_phandle_args *out_args);
344static struct clk_hw *
345of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
346#else
347static inline int of_parse_clkspec(const struct device_node *np, int index,
348 const char *name,
349 struct of_phandle_args *out_args)
350{
351 return -ENOENT;
352}
353static inline struct clk_hw *
354of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
355{
356 return ERR_PTR(-ENOENT);
357}
358#endif
359
360/**
361 * clk_core_get - Find the clk_core parent of a clk
362 * @core: clk to find parent of
363 * @p_index: parent index to search for
364 *
365 * This is the preferred method for clk providers to find the parent of a
366 * clk when that parent is external to the clk controller. The parent_names
367 * array is indexed and treated as a local name matching a string in the device
368 * node's 'clock-names' property or as the 'con_id' matching the device's
369 * dev_name() in a clk_lookup. This allows clk providers to use their own
370 * namespace instead of looking for a globally unique parent string.
371 *
372 * For example the following DT snippet would allow a clock registered by the
373 * clock-controller@c001 that has a clk_init_data::parent_data array
374 * with 'xtal' in the 'name' member to find the clock provided by the
375 * clock-controller@f00abcd without needing to get the globally unique name of
376 * the xtal clk.
377 *
378 * parent: clock-controller@f00abcd {
379 * reg = <0xf00abcd 0xabcd>;
380 * #clock-cells = <0>;
381 * };
382 *
383 * clock-controller@c001 {
384 * reg = <0xc001 0xf00d>;
385 * clocks = <&parent>;
386 * clock-names = "xtal";
387 * #clock-cells = <1>;
388 * };
389 *
390 * Returns: -ENOENT when the provider can't be found or the clk doesn't
391 * exist in the provider or the name can't be found in the DT node or
392 * in a clkdev lookup. NULL when the provider knows about the clk but it
393 * isn't provided on this system.
394 * A valid clk_core pointer when the clk can be found in the provider.
395 */
396static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
397{
398 const char *name = core->parents[p_index].fw_name;
399 int index = core->parents[p_index].index;
400 struct clk_hw *hw = ERR_PTR(-ENOENT);
401 struct device *dev = core->dev;
402 const char *dev_id = dev ? dev_name(dev) : NULL;
403 struct device_node *np = core->of_node;
404 struct of_phandle_args clkspec;
405
406 if (np && (name || index >= 0) &&
407 !of_parse_clkspec(np, index, name, &clkspec)) {
408 hw = of_clk_get_hw_from_clkspec(&clkspec);
409 of_node_put(clkspec.np);
410 } else if (name) {
411 /*
412 * If the DT search above couldn't find the provider fallback to
413 * looking up via clkdev based clk_lookups.
414 */
415 hw = clk_find_hw(dev_id, name);
416 }
417
418 if (IS_ERR(hw))
419 return ERR_CAST(hw);
420
421 return hw->core;
422}
423
424static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
425{
426 struct clk_parent_map *entry = &core->parents[index];
427 struct clk_core *parent;
428
429 if (entry->hw) {
430 parent = entry->hw->core;
431 } else {
432 parent = clk_core_get(core, index);
433 if (PTR_ERR(parent) == -ENOENT && entry->name)
434 parent = clk_core_lookup(entry->name);
435 }
436
437 /*
438 * We have a direct reference but it isn't registered yet?
439 * Orphan it and let clk_reparent() update the orphan status
440 * when the parent is registered.
441 */
442 if (!parent)
443 parent = ERR_PTR(-EPROBE_DEFER);
444
445 /* Only cache it if it's not an error */
446 if (!IS_ERR(parent))
447 entry->core = parent;
448}
449
450static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
451 u8 index)
452{
453 if (!core || index >= core->num_parents || !core->parents)
454 return NULL;
455
456 if (!core->parents[index].core)
457 clk_core_fill_parent_index(core, index);
458
459 return core->parents[index].core;
460}
461
462struct clk_hw *
463clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
464{
465 struct clk_core *parent;
466
467 parent = clk_core_get_parent_by_index(hw->core, index);
468
469 return !parent ? NULL : parent->hw;
470}
471EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
472
473unsigned int __clk_get_enable_count(struct clk *clk)
474{
475 return !clk ? 0 : clk->core->enable_count;
476}
477
478static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
479{
480 if (!core)
481 return 0;
482
483 if (!core->num_parents || core->parent)
484 return core->rate;
485
486 /*
487 * Clk must have a parent because num_parents > 0 but the parent isn't
488 * known yet. Best to return 0 as the rate of this clk until we can
489 * properly recalc the rate based on the parent's rate.
490 */
491 return 0;
492}
493
494unsigned long clk_hw_get_rate(const struct clk_hw *hw)
495{
496 return clk_core_get_rate_nolock(hw->core);
497}
498EXPORT_SYMBOL_GPL(clk_hw_get_rate);
499
500static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
501{
502 if (!core)
503 return 0;
504
505 return core->accuracy;
506}
507
508unsigned long clk_hw_get_flags(const struct clk_hw *hw)
509{
510 return hw->core->flags;
511}
512EXPORT_SYMBOL_GPL(clk_hw_get_flags);
513
514bool clk_hw_is_prepared(const struct clk_hw *hw)
515{
516 return clk_core_is_prepared(hw->core);
517}
518EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
519
520bool clk_hw_rate_is_protected(const struct clk_hw *hw)
521{
522 return clk_core_rate_is_protected(hw->core);
523}
524EXPORT_SYMBOL_GPL(clk_hw_rate_is_protected);
525
526bool clk_hw_is_enabled(const struct clk_hw *hw)
527{
528 return clk_core_is_enabled(hw->core);
529}
530EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
531
532bool __clk_is_enabled(struct clk *clk)
533{
534 if (!clk)
535 return false;
536
537 return clk_core_is_enabled(clk->core);
538}
539EXPORT_SYMBOL_GPL(__clk_is_enabled);
540
541static bool mux_is_better_rate(unsigned long rate, unsigned long now,
542 unsigned long best, unsigned long flags)
543{
544 if (flags & CLK_MUX_ROUND_CLOSEST)
545 return abs(now - rate) < abs(best - rate);
546
547 return now <= rate && now > best;
548}
549
550static void clk_core_init_rate_req(struct clk_core * const core,
551 struct clk_rate_request *req,
552 unsigned long rate);
553
554static int clk_core_round_rate_nolock(struct clk_core *core,
555 struct clk_rate_request *req);
556
557static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
558{
559 struct clk_core *tmp;
560 unsigned int i;
561
562 /* Optimize for the case where the parent is already the parent. */
563 if (core->parent == parent)
564 return true;
565
566 for (i = 0; i < core->num_parents; i++) {
567 tmp = clk_core_get_parent_by_index(core, i);
568 if (!tmp)
569 continue;
570
571 if (tmp == parent)
572 return true;
573 }
574
575 return false;
576}
577
578static void
579clk_core_forward_rate_req(struct clk_core *core,
580 const struct clk_rate_request *old_req,
581 struct clk_core *parent,
582 struct clk_rate_request *req,
583 unsigned long parent_rate)
584{
585 if (WARN_ON(!clk_core_has_parent(core, parent)))
586 return;
587
588 clk_core_init_rate_req(parent, req, parent_rate);
589
590 if (req->min_rate < old_req->min_rate)
591 req->min_rate = old_req->min_rate;
592
593 if (req->max_rate > old_req->max_rate)
594 req->max_rate = old_req->max_rate;
595}
596
597static int
598clk_core_determine_rate_no_reparent(struct clk_hw *hw,
599 struct clk_rate_request *req)
600{
601 struct clk_core *core = hw->core;
602 struct clk_core *parent = core->parent;
603 unsigned long best;
604 int ret;
605
606 if (core->flags & CLK_SET_RATE_PARENT) {
607 struct clk_rate_request parent_req;
608
609 if (!parent) {
610 req->rate = 0;
611 return 0;
612 }
613
614 clk_core_forward_rate_req(core, req, parent, &parent_req,
615 req->rate);
616
617 trace_clk_rate_request_start(&parent_req);
618
619 ret = clk_core_round_rate_nolock(parent, &parent_req);
620 if (ret)
621 return ret;
622
623 trace_clk_rate_request_done(&parent_req);
624
625 best = parent_req.rate;
626 } else if (parent) {
627 best = clk_core_get_rate_nolock(parent);
628 } else {
629 best = clk_core_get_rate_nolock(core);
630 }
631
632 req->best_parent_rate = best;
633 req->rate = best;
634
635 return 0;
636}
637
638int clk_mux_determine_rate_flags(struct clk_hw *hw,
639 struct clk_rate_request *req,
640 unsigned long flags)
641{
642 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
643 int i, num_parents, ret;
644 unsigned long best = 0;
645
646 /* if NO_REPARENT flag set, pass through to current parent */
647 if (core->flags & CLK_SET_RATE_NO_REPARENT)
648 return clk_core_determine_rate_no_reparent(hw, req);
649
650 /* find the parent that can provide the fastest rate <= rate */
651 num_parents = core->num_parents;
652 for (i = 0; i < num_parents; i++) {
653 unsigned long parent_rate;
654
655 parent = clk_core_get_parent_by_index(core, i);
656 if (!parent)
657 continue;
658
659 if (core->flags & CLK_SET_RATE_PARENT) {
660 struct clk_rate_request parent_req;
661
662 clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
663
664 trace_clk_rate_request_start(&parent_req);
665
666 ret = clk_core_round_rate_nolock(parent, &parent_req);
667 if (ret)
668 continue;
669
670 trace_clk_rate_request_done(&parent_req);
671
672 parent_rate = parent_req.rate;
673 } else {
674 parent_rate = clk_core_get_rate_nolock(parent);
675 }
676
677 if (mux_is_better_rate(req->rate, parent_rate,
678 best, flags)) {
679 best_parent = parent;
680 best = parent_rate;
681 }
682 }
683
684 if (!best_parent)
685 return -EINVAL;
686
687 req->best_parent_hw = best_parent->hw;
688 req->best_parent_rate = best;
689 req->rate = best;
690
691 return 0;
692}
693EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
694
695struct clk *__clk_lookup(const char *name)
696{
697 struct clk_core *core = clk_core_lookup(name);
698
699 return !core ? NULL : core->hw->clk;
700}
701
702static void clk_core_get_boundaries(struct clk_core *core,
703 unsigned long *min_rate,
704 unsigned long *max_rate)
705{
706 struct clk *clk_user;
707
708 lockdep_assert_held(&prepare_lock);
709
710 *min_rate = core->min_rate;
711 *max_rate = core->max_rate;
712
713 hlist_for_each_entry(clk_user, &core->clks, clks_node)
714 *min_rate = max(*min_rate, clk_user->min_rate);
715
716 hlist_for_each_entry(clk_user, &core->clks, clks_node)
717 *max_rate = min(*max_rate, clk_user->max_rate);
718}
719
720/*
721 * clk_hw_get_rate_range() - returns the clock rate range for a hw clk
722 * @hw: the hw clk we want to get the range from
723 * @min_rate: pointer to the variable that will hold the minimum
724 * @max_rate: pointer to the variable that will hold the maximum
725 *
726 * Fills the @min_rate and @max_rate variables with the minimum and
727 * maximum that clock can reach.
728 */
729void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
730 unsigned long *max_rate)
731{
732 clk_core_get_boundaries(hw->core, min_rate, max_rate);
733}
734EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
735
736static bool clk_core_check_boundaries(struct clk_core *core,
737 unsigned long min_rate,
738 unsigned long max_rate)
739{
740 struct clk *user;
741
742 lockdep_assert_held(&prepare_lock);
743
744 if (min_rate > core->max_rate || max_rate < core->min_rate)
745 return false;
746
747 hlist_for_each_entry(user, &core->clks, clks_node)
748 if (min_rate > user->max_rate || max_rate < user->min_rate)
749 return false;
750
751 return true;
752}
753
754void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
755 unsigned long max_rate)
756{
757 hw->core->min_rate = min_rate;
758 hw->core->max_rate = max_rate;
759}
760EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
761
762/*
763 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
764 * @hw: mux type clk to determine rate on
765 * @req: rate request, also used to return preferred parent and frequencies
766 *
767 * Helper for finding best parent to provide a given frequency. This can be used
768 * directly as a determine_rate callback (e.g. for a mux), or from a more
769 * complex clock that may combine a mux with other operations.
770 *
771 * Returns: 0 on success, -EERROR value on error
772 */
773int __clk_mux_determine_rate(struct clk_hw *hw,
774 struct clk_rate_request *req)
775{
776 return clk_mux_determine_rate_flags(hw, req, 0);
777}
778EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
779
780int __clk_mux_determine_rate_closest(struct clk_hw *hw,
781 struct clk_rate_request *req)
782{
783 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
784}
785EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
786
787/*
788 * clk_hw_determine_rate_no_reparent - clk_ops::determine_rate implementation for a clk that doesn't reparent
789 * @hw: mux type clk to determine rate on
790 * @req: rate request, also used to return preferred frequency
791 *
792 * Helper for finding best parent rate to provide a given frequency.
793 * This can be used directly as a determine_rate callback (e.g. for a
794 * mux), or from a more complex clock that may combine a mux with other
795 * operations.
796 *
797 * Returns: 0 on success, -EERROR value on error
798 */
799int clk_hw_determine_rate_no_reparent(struct clk_hw *hw,
800 struct clk_rate_request *req)
801{
802 return clk_core_determine_rate_no_reparent(hw, req);
803}
804EXPORT_SYMBOL_GPL(clk_hw_determine_rate_no_reparent);
805
806/*** clk api ***/
807
808static void clk_core_rate_unprotect(struct clk_core *core)
809{
810 lockdep_assert_held(&prepare_lock);
811
812 if (!core)
813 return;
814
815 if (WARN(core->protect_count == 0,
816 "%s already unprotected\n", core->name))
817 return;
818
819 if (--core->protect_count > 0)
820 return;
821
822 clk_core_rate_unprotect(core->parent);
823}
824
825static int clk_core_rate_nuke_protect(struct clk_core *core)
826{
827 int ret;
828
829 lockdep_assert_held(&prepare_lock);
830
831 if (!core)
832 return -EINVAL;
833
834 if (core->protect_count == 0)
835 return 0;
836
837 ret = core->protect_count;
838 core->protect_count = 1;
839 clk_core_rate_unprotect(core);
840
841 return ret;
842}
843
844/**
845 * clk_rate_exclusive_put - release exclusivity over clock rate control
846 * @clk: the clk over which the exclusivity is released
847 *
848 * clk_rate_exclusive_put() completes a critical section during which a clock
849 * consumer cannot tolerate any other consumer making any operation on the
850 * clock which could result in a rate change or rate glitch. Exclusive clocks
851 * cannot have their rate changed, either directly or indirectly due to changes
852 * further up the parent chain of clocks. As a result, clocks up parent chain
853 * also get under exclusive control of the calling consumer.
854 *
855 * If exlusivity is claimed more than once on clock, even by the same consumer,
856 * the rate effectively gets locked as exclusivity can't be preempted.
857 *
858 * Calls to clk_rate_exclusive_put() must be balanced with calls to
859 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
860 * error status.
861 */
862void clk_rate_exclusive_put(struct clk *clk)
863{
864 if (!clk)
865 return;
866
867 clk_prepare_lock();
868
869 /*
870 * if there is something wrong with this consumer protect count, stop
871 * here before messing with the provider
872 */
873 if (WARN_ON(clk->exclusive_count <= 0))
874 goto out;
875
876 clk_core_rate_unprotect(clk->core);
877 clk->exclusive_count--;
878out:
879 clk_prepare_unlock();
880}
881EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
882
883static void clk_core_rate_protect(struct clk_core *core)
884{
885 lockdep_assert_held(&prepare_lock);
886
887 if (!core)
888 return;
889
890 if (core->protect_count == 0)
891 clk_core_rate_protect(core->parent);
892
893 core->protect_count++;
894}
895
896static void clk_core_rate_restore_protect(struct clk_core *core, int count)
897{
898 lockdep_assert_held(&prepare_lock);
899
900 if (!core)
901 return;
902
903 if (count == 0)
904 return;
905
906 clk_core_rate_protect(core);
907 core->protect_count = count;
908}
909
910/**
911 * clk_rate_exclusive_get - get exclusivity over the clk rate control
912 * @clk: the clk over which the exclusity of rate control is requested
913 *
914 * clk_rate_exclusive_get() begins a critical section during which a clock
915 * consumer cannot tolerate any other consumer making any operation on the
916 * clock which could result in a rate change or rate glitch. Exclusive clocks
917 * cannot have their rate changed, either directly or indirectly due to changes
918 * further up the parent chain of clocks. As a result, clocks up parent chain
919 * also get under exclusive control of the calling consumer.
920 *
921 * If exlusivity is claimed more than once on clock, even by the same consumer,
922 * the rate effectively gets locked as exclusivity can't be preempted.
923 *
924 * Calls to clk_rate_exclusive_get() should be balanced with calls to
925 * clk_rate_exclusive_put(). Calls to this function may sleep.
926 * Returns 0 on success, -EERROR otherwise
927 */
928int clk_rate_exclusive_get(struct clk *clk)
929{
930 if (!clk)
931 return 0;
932
933 clk_prepare_lock();
934 clk_core_rate_protect(clk->core);
935 clk->exclusive_count++;
936 clk_prepare_unlock();
937
938 return 0;
939}
940EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
941
942static void clk_core_unprepare(struct clk_core *core)
943{
944 lockdep_assert_held(&prepare_lock);
945
946 if (!core)
947 return;
948
949 if (WARN(core->prepare_count == 0,
950 "%s already unprepared\n", core->name))
951 return;
952
953 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
954 "Unpreparing critical %s\n", core->name))
955 return;
956
957 if (core->flags & CLK_SET_RATE_GATE)
958 clk_core_rate_unprotect(core);
959
960 if (--core->prepare_count > 0)
961 return;
962
963 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
964
965 trace_clk_unprepare(core);
966
967 if (core->ops->unprepare)
968 core->ops->unprepare(core->hw);
969
970 trace_clk_unprepare_complete(core);
971 clk_core_unprepare(core->parent);
972 clk_pm_runtime_put(core);
973}
974
975static void clk_core_unprepare_lock(struct clk_core *core)
976{
977 clk_prepare_lock();
978 clk_core_unprepare(core);
979 clk_prepare_unlock();
980}
981
982/**
983 * clk_unprepare - undo preparation of a clock source
984 * @clk: the clk being unprepared
985 *
986 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
987 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
988 * if the operation may sleep. One example is a clk which is accessed over
989 * I2c. In the complex case a clk gate operation may require a fast and a slow
990 * part. It is this reason that clk_unprepare and clk_disable are not mutually
991 * exclusive. In fact clk_disable must be called before clk_unprepare.
992 */
993void clk_unprepare(struct clk *clk)
994{
995 if (IS_ERR_OR_NULL(clk))
996 return;
997
998 clk_core_unprepare_lock(clk->core);
999}
1000EXPORT_SYMBOL_GPL(clk_unprepare);
1001
1002static int clk_core_prepare(struct clk_core *core)
1003{
1004 int ret = 0;
1005
1006 lockdep_assert_held(&prepare_lock);
1007
1008 if (!core)
1009 return 0;
1010
1011 if (core->prepare_count == 0) {
1012 ret = clk_pm_runtime_get(core);
1013 if (ret)
1014 return ret;
1015
1016 ret = clk_core_prepare(core->parent);
1017 if (ret)
1018 goto runtime_put;
1019
1020 trace_clk_prepare(core);
1021
1022 if (core->ops->prepare)
1023 ret = core->ops->prepare(core->hw);
1024
1025 trace_clk_prepare_complete(core);
1026
1027 if (ret)
1028 goto unprepare;
1029 }
1030
1031 core->prepare_count++;
1032
1033 /*
1034 * CLK_SET_RATE_GATE is a special case of clock protection
1035 * Instead of a consumer claiming exclusive rate control, it is
1036 * actually the provider which prevents any consumer from making any
1037 * operation which could result in a rate change or rate glitch while
1038 * the clock is prepared.
1039 */
1040 if (core->flags & CLK_SET_RATE_GATE)
1041 clk_core_rate_protect(core);
1042
1043 return 0;
1044unprepare:
1045 clk_core_unprepare(core->parent);
1046runtime_put:
1047 clk_pm_runtime_put(core);
1048 return ret;
1049}
1050
1051static int clk_core_prepare_lock(struct clk_core *core)
1052{
1053 int ret;
1054
1055 clk_prepare_lock();
1056 ret = clk_core_prepare(core);
1057 clk_prepare_unlock();
1058
1059 return ret;
1060}
1061
1062/**
1063 * clk_prepare - prepare a clock source
1064 * @clk: the clk being prepared
1065 *
1066 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
1067 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
1068 * operation may sleep. One example is a clk which is accessed over I2c. In
1069 * the complex case a clk ungate operation may require a fast and a slow part.
1070 * It is this reason that clk_prepare and clk_enable are not mutually
1071 * exclusive. In fact clk_prepare must be called before clk_enable.
1072 * Returns 0 on success, -EERROR otherwise.
1073 */
1074int clk_prepare(struct clk *clk)
1075{
1076 if (!clk)
1077 return 0;
1078
1079 return clk_core_prepare_lock(clk->core);
1080}
1081EXPORT_SYMBOL_GPL(clk_prepare);
1082
1083static void clk_core_disable(struct clk_core *core)
1084{
1085 lockdep_assert_held(&enable_lock);
1086
1087 if (!core)
1088 return;
1089
1090 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
1091 return;
1092
1093 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
1094 "Disabling critical %s\n", core->name))
1095 return;
1096
1097 if (--core->enable_count > 0)
1098 return;
1099
1100 trace_clk_disable(core);
1101
1102 if (core->ops->disable)
1103 core->ops->disable(core->hw);
1104
1105 trace_clk_disable_complete(core);
1106
1107 clk_core_disable(core->parent);
1108}
1109
1110static void clk_core_disable_lock(struct clk_core *core)
1111{
1112 unsigned long flags;
1113
1114 flags = clk_enable_lock();
1115 clk_core_disable(core);
1116 clk_enable_unlock(flags);
1117}
1118
1119/**
1120 * clk_disable - gate a clock
1121 * @clk: the clk being gated
1122 *
1123 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
1124 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1125 * clk if the operation is fast and will never sleep. One example is a
1126 * SoC-internal clk which is controlled via simple register writes. In the
1127 * complex case a clk gate operation may require a fast and a slow part. It is
1128 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1129 * In fact clk_disable must be called before clk_unprepare.
1130 */
1131void clk_disable(struct clk *clk)
1132{
1133 if (IS_ERR_OR_NULL(clk))
1134 return;
1135
1136 clk_core_disable_lock(clk->core);
1137}
1138EXPORT_SYMBOL_GPL(clk_disable);
1139
1140static int clk_core_enable(struct clk_core *core)
1141{
1142 int ret = 0;
1143
1144 lockdep_assert_held(&enable_lock);
1145
1146 if (!core)
1147 return 0;
1148
1149 if (WARN(core->prepare_count == 0,
1150 "Enabling unprepared %s\n", core->name))
1151 return -ESHUTDOWN;
1152
1153 if (core->enable_count == 0) {
1154 ret = clk_core_enable(core->parent);
1155
1156 if (ret)
1157 return ret;
1158
1159 trace_clk_enable(core);
1160
1161 if (core->ops->enable)
1162 ret = core->ops->enable(core->hw);
1163
1164 trace_clk_enable_complete(core);
1165
1166 if (ret) {
1167 clk_core_disable(core->parent);
1168 return ret;
1169 }
1170 }
1171
1172 core->enable_count++;
1173 return 0;
1174}
1175
1176static int clk_core_enable_lock(struct clk_core *core)
1177{
1178 unsigned long flags;
1179 int ret;
1180
1181 flags = clk_enable_lock();
1182 ret = clk_core_enable(core);
1183 clk_enable_unlock(flags);
1184
1185 return ret;
1186}
1187
1188/**
1189 * clk_gate_restore_context - restore context for poweroff
1190 * @hw: the clk_hw pointer of clock whose state is to be restored
1191 *
1192 * The clock gate restore context function enables or disables
1193 * the gate clocks based on the enable_count. This is done in cases
1194 * where the clock context is lost and based on the enable_count
1195 * the clock either needs to be enabled/disabled. This
1196 * helps restore the state of gate clocks.
1197 */
1198void clk_gate_restore_context(struct clk_hw *hw)
1199{
1200 struct clk_core *core = hw->core;
1201
1202 if (core->enable_count)
1203 core->ops->enable(hw);
1204 else
1205 core->ops->disable(hw);
1206}
1207EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1208
1209static int clk_core_save_context(struct clk_core *core)
1210{
1211 struct clk_core *child;
1212 int ret = 0;
1213
1214 hlist_for_each_entry(child, &core->children, child_node) {
1215 ret = clk_core_save_context(child);
1216 if (ret < 0)
1217 return ret;
1218 }
1219
1220 if (core->ops && core->ops->save_context)
1221 ret = core->ops->save_context(core->hw);
1222
1223 return ret;
1224}
1225
1226static void clk_core_restore_context(struct clk_core *core)
1227{
1228 struct clk_core *child;
1229
1230 if (core->ops && core->ops->restore_context)
1231 core->ops->restore_context(core->hw);
1232
1233 hlist_for_each_entry(child, &core->children, child_node)
1234 clk_core_restore_context(child);
1235}
1236
1237/**
1238 * clk_save_context - save clock context for poweroff
1239 *
1240 * Saves the context of the clock register for powerstates in which the
1241 * contents of the registers will be lost. Occurs deep within the suspend
1242 * code. Returns 0 on success.
1243 */
1244int clk_save_context(void)
1245{
1246 struct clk_core *clk;
1247 int ret;
1248
1249 hlist_for_each_entry(clk, &clk_root_list, child_node) {
1250 ret = clk_core_save_context(clk);
1251 if (ret < 0)
1252 return ret;
1253 }
1254
1255 hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1256 ret = clk_core_save_context(clk);
1257 if (ret < 0)
1258 return ret;
1259 }
1260
1261 return 0;
1262}
1263EXPORT_SYMBOL_GPL(clk_save_context);
1264
1265/**
1266 * clk_restore_context - restore clock context after poweroff
1267 *
1268 * Restore the saved clock context upon resume.
1269 *
1270 */
1271void clk_restore_context(void)
1272{
1273 struct clk_core *core;
1274
1275 hlist_for_each_entry(core, &clk_root_list, child_node)
1276 clk_core_restore_context(core);
1277
1278 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1279 clk_core_restore_context(core);
1280}
1281EXPORT_SYMBOL_GPL(clk_restore_context);
1282
1283/**
1284 * clk_enable - ungate a clock
1285 * @clk: the clk being ungated
1286 *
1287 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1288 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1289 * if the operation will never sleep. One example is a SoC-internal clk which
1290 * is controlled via simple register writes. In the complex case a clk ungate
1291 * operation may require a fast and a slow part. It is this reason that
1292 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1293 * must be called before clk_enable. Returns 0 on success, -EERROR
1294 * otherwise.
1295 */
1296int clk_enable(struct clk *clk)
1297{
1298 if (!clk)
1299 return 0;
1300
1301 return clk_core_enable_lock(clk->core);
1302}
1303EXPORT_SYMBOL_GPL(clk_enable);
1304
1305/**
1306 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1307 * @clk: clock source
1308 *
1309 * Returns true if clk_prepare() implicitly enables the clock, effectively
1310 * making clk_enable()/clk_disable() no-ops, false otherwise.
1311 *
1312 * This is of interest mainly to power management code where actually
1313 * disabling the clock also requires unpreparing it to have any material
1314 * effect.
1315 *
1316 * Regardless of the value returned here, the caller must always invoke
1317 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
1318 * to be right.
1319 */
1320bool clk_is_enabled_when_prepared(struct clk *clk)
1321{
1322 return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1323}
1324EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1325
1326static int clk_core_prepare_enable(struct clk_core *core)
1327{
1328 int ret;
1329
1330 ret = clk_core_prepare_lock(core);
1331 if (ret)
1332 return ret;
1333
1334 ret = clk_core_enable_lock(core);
1335 if (ret)
1336 clk_core_unprepare_lock(core);
1337
1338 return ret;
1339}
1340
1341static void clk_core_disable_unprepare(struct clk_core *core)
1342{
1343 clk_core_disable_lock(core);
1344 clk_core_unprepare_lock(core);
1345}
1346
1347static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1348{
1349 struct clk_core *child;
1350
1351 lockdep_assert_held(&prepare_lock);
1352
1353 hlist_for_each_entry(child, &core->children, child_node)
1354 clk_unprepare_unused_subtree(child);
1355
1356 if (core->prepare_count)
1357 return;
1358
1359 if (core->flags & CLK_IGNORE_UNUSED)
1360 return;
1361
1362 if (clk_pm_runtime_get(core))
1363 return;
1364
1365 if (clk_core_is_prepared(core)) {
1366 trace_clk_unprepare(core);
1367 if (core->ops->unprepare_unused)
1368 core->ops->unprepare_unused(core->hw);
1369 else if (core->ops->unprepare)
1370 core->ops->unprepare(core->hw);
1371 trace_clk_unprepare_complete(core);
1372 }
1373
1374 clk_pm_runtime_put(core);
1375}
1376
1377static void __init clk_disable_unused_subtree(struct clk_core *core)
1378{
1379 struct clk_core *child;
1380 unsigned long flags;
1381
1382 lockdep_assert_held(&prepare_lock);
1383
1384 hlist_for_each_entry(child, &core->children, child_node)
1385 clk_disable_unused_subtree(child);
1386
1387 if (core->flags & CLK_OPS_PARENT_ENABLE)
1388 clk_core_prepare_enable(core->parent);
1389
1390 if (clk_pm_runtime_get(core))
1391 goto unprepare_out;
1392
1393 flags = clk_enable_lock();
1394
1395 if (core->enable_count)
1396 goto unlock_out;
1397
1398 if (core->flags & CLK_IGNORE_UNUSED)
1399 goto unlock_out;
1400
1401 /*
1402 * some gate clocks have special needs during the disable-unused
1403 * sequence. call .disable_unused if available, otherwise fall
1404 * back to .disable
1405 */
1406 if (clk_core_is_enabled(core)) {
1407 trace_clk_disable(core);
1408 if (core->ops->disable_unused)
1409 core->ops->disable_unused(core->hw);
1410 else if (core->ops->disable)
1411 core->ops->disable(core->hw);
1412 trace_clk_disable_complete(core);
1413 }
1414
1415unlock_out:
1416 clk_enable_unlock(flags);
1417 clk_pm_runtime_put(core);
1418unprepare_out:
1419 if (core->flags & CLK_OPS_PARENT_ENABLE)
1420 clk_core_disable_unprepare(core->parent);
1421}
1422
1423static bool clk_ignore_unused __initdata;
1424static int __init clk_ignore_unused_setup(char *__unused)
1425{
1426 clk_ignore_unused = true;
1427 return 1;
1428}
1429__setup("clk_ignore_unused", clk_ignore_unused_setup);
1430
1431static int __init clk_disable_unused(void)
1432{
1433 struct clk_core *core;
1434
1435 if (clk_ignore_unused) {
1436 pr_warn("clk: Not disabling unused clocks\n");
1437 return 0;
1438 }
1439
1440 pr_info("clk: Disabling unused clocks\n");
1441
1442 clk_prepare_lock();
1443
1444 hlist_for_each_entry(core, &clk_root_list, child_node)
1445 clk_disable_unused_subtree(core);
1446
1447 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1448 clk_disable_unused_subtree(core);
1449
1450 hlist_for_each_entry(core, &clk_root_list, child_node)
1451 clk_unprepare_unused_subtree(core);
1452
1453 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1454 clk_unprepare_unused_subtree(core);
1455
1456 clk_prepare_unlock();
1457
1458 return 0;
1459}
1460late_initcall_sync(clk_disable_unused);
1461
1462static int clk_core_determine_round_nolock(struct clk_core *core,
1463 struct clk_rate_request *req)
1464{
1465 long rate;
1466
1467 lockdep_assert_held(&prepare_lock);
1468
1469 if (!core)
1470 return 0;
1471
1472 /*
1473 * Some clock providers hand-craft their clk_rate_requests and
1474 * might not fill min_rate and max_rate.
1475 *
1476 * If it's the case, clamping the rate is equivalent to setting
1477 * the rate to 0 which is bad. Skip the clamping but complain so
1478 * that it gets fixed, hopefully.
1479 */
1480 if (!req->min_rate && !req->max_rate)
1481 pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
1482 __func__, core->name);
1483 else
1484 req->rate = clamp(req->rate, req->min_rate, req->max_rate);
1485
1486 /*
1487 * At this point, core protection will be disabled
1488 * - if the provider is not protected at all
1489 * - if the calling consumer is the only one which has exclusivity
1490 * over the provider
1491 */
1492 if (clk_core_rate_is_protected(core)) {
1493 req->rate = core->rate;
1494 } else if (core->ops->determine_rate) {
1495 return core->ops->determine_rate(core->hw, req);
1496 } else if (core->ops->round_rate) {
1497 rate = core->ops->round_rate(core->hw, req->rate,
1498 &req->best_parent_rate);
1499 if (rate < 0)
1500 return rate;
1501
1502 req->rate = rate;
1503 } else {
1504 return -EINVAL;
1505 }
1506
1507 return 0;
1508}
1509
1510static void clk_core_init_rate_req(struct clk_core * const core,
1511 struct clk_rate_request *req,
1512 unsigned long rate)
1513{
1514 struct clk_core *parent;
1515
1516 if (WARN_ON(!req))
1517 return;
1518
1519 memset(req, 0, sizeof(*req));
1520 req->max_rate = ULONG_MAX;
1521
1522 if (!core)
1523 return;
1524
1525 req->core = core;
1526 req->rate = rate;
1527 clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
1528
1529 parent = core->parent;
1530 if (parent) {
1531 req->best_parent_hw = parent->hw;
1532 req->best_parent_rate = parent->rate;
1533 } else {
1534 req->best_parent_hw = NULL;
1535 req->best_parent_rate = 0;
1536 }
1537}
1538
1539/**
1540 * clk_hw_init_rate_request - Initializes a clk_rate_request
1541 * @hw: the clk for which we want to submit a rate request
1542 * @req: the clk_rate_request structure we want to initialise
1543 * @rate: the rate which is to be requested
1544 *
1545 * Initializes a clk_rate_request structure to submit to
1546 * __clk_determine_rate() or similar functions.
1547 */
1548void clk_hw_init_rate_request(const struct clk_hw *hw,
1549 struct clk_rate_request *req,
1550 unsigned long rate)
1551{
1552 if (WARN_ON(!hw || !req))
1553 return;
1554
1555 clk_core_init_rate_req(hw->core, req, rate);
1556}
1557EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
1558
1559/**
1560 * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
1561 * @hw: the original clock that got the rate request
1562 * @old_req: the original clk_rate_request structure we want to forward
1563 * @parent: the clk we want to forward @old_req to
1564 * @req: the clk_rate_request structure we want to initialise
1565 * @parent_rate: The rate which is to be requested to @parent
1566 *
1567 * Initializes a clk_rate_request structure to submit to a clock parent
1568 * in __clk_determine_rate() or similar functions.
1569 */
1570void clk_hw_forward_rate_request(const struct clk_hw *hw,
1571 const struct clk_rate_request *old_req,
1572 const struct clk_hw *parent,
1573 struct clk_rate_request *req,
1574 unsigned long parent_rate)
1575{
1576 if (WARN_ON(!hw || !old_req || !parent || !req))
1577 return;
1578
1579 clk_core_forward_rate_req(hw->core, old_req,
1580 parent->core, req,
1581 parent_rate);
1582}
1583EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);
1584
1585static bool clk_core_can_round(struct clk_core * const core)
1586{
1587 return core->ops->determine_rate || core->ops->round_rate;
1588}
1589
1590static int clk_core_round_rate_nolock(struct clk_core *core,
1591 struct clk_rate_request *req)
1592{
1593 int ret;
1594
1595 lockdep_assert_held(&prepare_lock);
1596
1597 if (!core) {
1598 req->rate = 0;
1599 return 0;
1600 }
1601
1602 if (clk_core_can_round(core))
1603 return clk_core_determine_round_nolock(core, req);
1604
1605 if (core->flags & CLK_SET_RATE_PARENT) {
1606 struct clk_rate_request parent_req;
1607
1608 clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
1609
1610 trace_clk_rate_request_start(&parent_req);
1611
1612 ret = clk_core_round_rate_nolock(core->parent, &parent_req);
1613 if (ret)
1614 return ret;
1615
1616 trace_clk_rate_request_done(&parent_req);
1617
1618 req->best_parent_rate = parent_req.rate;
1619 req->rate = parent_req.rate;
1620
1621 return 0;
1622 }
1623
1624 req->rate = core->rate;
1625 return 0;
1626}
1627
1628/**
1629 * __clk_determine_rate - get the closest rate actually supported by a clock
1630 * @hw: determine the rate of this clock
1631 * @req: target rate request
1632 *
1633 * Useful for clk_ops such as .set_rate and .determine_rate.
1634 */
1635int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1636{
1637 if (!hw) {
1638 req->rate = 0;
1639 return 0;
1640 }
1641
1642 return clk_core_round_rate_nolock(hw->core, req);
1643}
1644EXPORT_SYMBOL_GPL(__clk_determine_rate);
1645
1646/**
1647 * clk_hw_round_rate() - round the given rate for a hw clk
1648 * @hw: the hw clk for which we are rounding a rate
1649 * @rate: the rate which is to be rounded
1650 *
1651 * Takes in a rate as input and rounds it to a rate that the clk can actually
1652 * use.
1653 *
1654 * Context: prepare_lock must be held.
1655 * For clk providers to call from within clk_ops such as .round_rate,
1656 * .determine_rate.
1657 *
1658 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1659 * else returns the parent rate.
1660 */
1661unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1662{
1663 int ret;
1664 struct clk_rate_request req;
1665
1666 clk_core_init_rate_req(hw->core, &req, rate);
1667
1668 trace_clk_rate_request_start(&req);
1669
1670 ret = clk_core_round_rate_nolock(hw->core, &req);
1671 if (ret)
1672 return 0;
1673
1674 trace_clk_rate_request_done(&req);
1675
1676 return req.rate;
1677}
1678EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1679
1680/**
1681 * clk_round_rate - round the given rate for a clk
1682 * @clk: the clk for which we are rounding a rate
1683 * @rate: the rate which is to be rounded
1684 *
1685 * Takes in a rate as input and rounds it to a rate that the clk can actually
1686 * use which is then returned. If clk doesn't support round_rate operation
1687 * then the parent rate is returned.
1688 */
1689long clk_round_rate(struct clk *clk, unsigned long rate)
1690{
1691 struct clk_rate_request req;
1692 int ret;
1693
1694 if (!clk)
1695 return 0;
1696
1697 clk_prepare_lock();
1698
1699 if (clk->exclusive_count)
1700 clk_core_rate_unprotect(clk->core);
1701
1702 clk_core_init_rate_req(clk->core, &req, rate);
1703
1704 trace_clk_rate_request_start(&req);
1705
1706 ret = clk_core_round_rate_nolock(clk->core, &req);
1707
1708 trace_clk_rate_request_done(&req);
1709
1710 if (clk->exclusive_count)
1711 clk_core_rate_protect(clk->core);
1712
1713 clk_prepare_unlock();
1714
1715 if (ret)
1716 return ret;
1717
1718 return req.rate;
1719}
1720EXPORT_SYMBOL_GPL(clk_round_rate);
1721
1722/**
1723 * __clk_notify - call clk notifier chain
1724 * @core: clk that is changing rate
1725 * @msg: clk notifier type (see include/linux/clk.h)
1726 * @old_rate: old clk rate
1727 * @new_rate: new clk rate
1728 *
1729 * Triggers a notifier call chain on the clk rate-change notification
1730 * for 'clk'. Passes a pointer to the struct clk and the previous
1731 * and current rates to the notifier callback. Intended to be called by
1732 * internal clock code only. Returns NOTIFY_DONE from the last driver
1733 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1734 * a driver returns that.
1735 */
1736static int __clk_notify(struct clk_core *core, unsigned long msg,
1737 unsigned long old_rate, unsigned long new_rate)
1738{
1739 struct clk_notifier *cn;
1740 struct clk_notifier_data cnd;
1741 int ret = NOTIFY_DONE;
1742
1743 cnd.old_rate = old_rate;
1744 cnd.new_rate = new_rate;
1745
1746 list_for_each_entry(cn, &clk_notifier_list, node) {
1747 if (cn->clk->core == core) {
1748 cnd.clk = cn->clk;
1749 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1750 &cnd);
1751 if (ret & NOTIFY_STOP_MASK)
1752 return ret;
1753 }
1754 }
1755
1756 return ret;
1757}
1758
1759/**
1760 * __clk_recalc_accuracies
1761 * @core: first clk in the subtree
1762 *
1763 * Walks the subtree of clks starting with clk and recalculates accuracies as
1764 * it goes. Note that if a clk does not implement the .recalc_accuracy
1765 * callback then it is assumed that the clock will take on the accuracy of its
1766 * parent.
1767 */
1768static void __clk_recalc_accuracies(struct clk_core *core)
1769{
1770 unsigned long parent_accuracy = 0;
1771 struct clk_core *child;
1772
1773 lockdep_assert_held(&prepare_lock);
1774
1775 if (core->parent)
1776 parent_accuracy = core->parent->accuracy;
1777
1778 if (core->ops->recalc_accuracy)
1779 core->accuracy = core->ops->recalc_accuracy(core->hw,
1780 parent_accuracy);
1781 else
1782 core->accuracy = parent_accuracy;
1783
1784 hlist_for_each_entry(child, &core->children, child_node)
1785 __clk_recalc_accuracies(child);
1786}
1787
1788static long clk_core_get_accuracy_recalc(struct clk_core *core)
1789{
1790 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1791 __clk_recalc_accuracies(core);
1792
1793 return clk_core_get_accuracy_no_lock(core);
1794}
1795
1796/**
1797 * clk_get_accuracy - return the accuracy of clk
1798 * @clk: the clk whose accuracy is being returned
1799 *
1800 * Simply returns the cached accuracy of the clk, unless
1801 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1802 * issued.
1803 * If clk is NULL then returns 0.
1804 */
1805long clk_get_accuracy(struct clk *clk)
1806{
1807 long accuracy;
1808
1809 if (!clk)
1810 return 0;
1811
1812 clk_prepare_lock();
1813 accuracy = clk_core_get_accuracy_recalc(clk->core);
1814 clk_prepare_unlock();
1815
1816 return accuracy;
1817}
1818EXPORT_SYMBOL_GPL(clk_get_accuracy);
1819
1820static unsigned long clk_recalc(struct clk_core *core,
1821 unsigned long parent_rate)
1822{
1823 unsigned long rate = parent_rate;
1824
1825 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1826 rate = core->ops->recalc_rate(core->hw, parent_rate);
1827 clk_pm_runtime_put(core);
1828 }
1829 return rate;
1830}
1831
1832/**
1833 * __clk_recalc_rates
1834 * @core: first clk in the subtree
1835 * @update_req: Whether req_rate should be updated with the new rate
1836 * @msg: notification type (see include/linux/clk.h)
1837 *
1838 * Walks the subtree of clks starting with clk and recalculates rates as it
1839 * goes. Note that if a clk does not implement the .recalc_rate callback then
1840 * it is assumed that the clock will take on the rate of its parent.
1841 *
1842 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1843 * if necessary.
1844 */
1845static void __clk_recalc_rates(struct clk_core *core, bool update_req,
1846 unsigned long msg)
1847{
1848 unsigned long old_rate;
1849 unsigned long parent_rate = 0;
1850 struct clk_core *child;
1851
1852 lockdep_assert_held(&prepare_lock);
1853
1854 old_rate = core->rate;
1855
1856 if (core->parent)
1857 parent_rate = core->parent->rate;
1858
1859 core->rate = clk_recalc(core, parent_rate);
1860 if (update_req)
1861 core->req_rate = core->rate;
1862
1863 /*
1864 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1865 * & ABORT_RATE_CHANGE notifiers
1866 */
1867 if (core->notifier_count && msg)
1868 __clk_notify(core, msg, old_rate, core->rate);
1869
1870 hlist_for_each_entry(child, &core->children, child_node)
1871 __clk_recalc_rates(child, update_req, msg);
1872}
1873
1874static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1875{
1876 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1877 __clk_recalc_rates(core, false, 0);
1878
1879 return clk_core_get_rate_nolock(core);
1880}
1881
1882/**
1883 * clk_get_rate - return the rate of clk
1884 * @clk: the clk whose rate is being returned
1885 *
1886 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1887 * is set, which means a recalc_rate will be issued. Can be called regardless of
1888 * the clock enabledness. If clk is NULL, or if an error occurred, then returns
1889 * 0.
1890 */
1891unsigned long clk_get_rate(struct clk *clk)
1892{
1893 unsigned long rate;
1894
1895 if (!clk)
1896 return 0;
1897
1898 clk_prepare_lock();
1899 rate = clk_core_get_rate_recalc(clk->core);
1900 clk_prepare_unlock();
1901
1902 return rate;
1903}
1904EXPORT_SYMBOL_GPL(clk_get_rate);
1905
1906static int clk_fetch_parent_index(struct clk_core *core,
1907 struct clk_core *parent)
1908{
1909 int i;
1910
1911 if (!parent)
1912 return -EINVAL;
1913
1914 for (i = 0; i < core->num_parents; i++) {
1915 /* Found it first try! */
1916 if (core->parents[i].core == parent)
1917 return i;
1918
1919 /* Something else is here, so keep looking */
1920 if (core->parents[i].core)
1921 continue;
1922
1923 /* Maybe core hasn't been cached but the hw is all we know? */
1924 if (core->parents[i].hw) {
1925 if (core->parents[i].hw == parent->hw)
1926 break;
1927
1928 /* Didn't match, but we're expecting a clk_hw */
1929 continue;
1930 }
1931
1932 /* Maybe it hasn't been cached (clk_set_parent() path) */
1933 if (parent == clk_core_get(core, i))
1934 break;
1935
1936 /* Fallback to comparing globally unique names */
1937 if (core->parents[i].name &&
1938 !strcmp(parent->name, core->parents[i].name))
1939 break;
1940 }
1941
1942 if (i == core->num_parents)
1943 return -EINVAL;
1944
1945 core->parents[i].core = parent;
1946 return i;
1947}
1948
1949/**
1950 * clk_hw_get_parent_index - return the index of the parent clock
1951 * @hw: clk_hw associated with the clk being consumed
1952 *
1953 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
1954 * clock does not have a current parent.
1955 */
1956int clk_hw_get_parent_index(struct clk_hw *hw)
1957{
1958 struct clk_hw *parent = clk_hw_get_parent(hw);
1959
1960 if (WARN_ON(parent == NULL))
1961 return -EINVAL;
1962
1963 return clk_fetch_parent_index(hw->core, parent->core);
1964}
1965EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
1966
1967/*
1968 * Update the orphan status of @core and all its children.
1969 */
1970static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1971{
1972 struct clk_core *child;
1973
1974 core->orphan = is_orphan;
1975
1976 hlist_for_each_entry(child, &core->children, child_node)
1977 clk_core_update_orphan_status(child, is_orphan);
1978}
1979
1980static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1981{
1982 bool was_orphan = core->orphan;
1983
1984 hlist_del(&core->child_node);
1985
1986 if (new_parent) {
1987 bool becomes_orphan = new_parent->orphan;
1988
1989 /* avoid duplicate POST_RATE_CHANGE notifications */
1990 if (new_parent->new_child == core)
1991 new_parent->new_child = NULL;
1992
1993 hlist_add_head(&core->child_node, &new_parent->children);
1994
1995 if (was_orphan != becomes_orphan)
1996 clk_core_update_orphan_status(core, becomes_orphan);
1997 } else {
1998 hlist_add_head(&core->child_node, &clk_orphan_list);
1999 if (!was_orphan)
2000 clk_core_update_orphan_status(core, true);
2001 }
2002
2003 core->parent = new_parent;
2004}
2005
2006static struct clk_core *__clk_set_parent_before(struct clk_core *core,
2007 struct clk_core *parent)
2008{
2009 unsigned long flags;
2010 struct clk_core *old_parent = core->parent;
2011
2012 /*
2013 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
2014 *
2015 * 2. Migrate prepare state between parents and prevent race with
2016 * clk_enable().
2017 *
2018 * If the clock is not prepared, then a race with
2019 * clk_enable/disable() is impossible since we already have the
2020 * prepare lock (future calls to clk_enable() need to be preceded by
2021 * a clk_prepare()).
2022 *
2023 * If the clock is prepared, migrate the prepared state to the new
2024 * parent and also protect against a race with clk_enable() by
2025 * forcing the clock and the new parent on. This ensures that all
2026 * future calls to clk_enable() are practically NOPs with respect to
2027 * hardware and software states.
2028 *
2029 * See also: Comment for clk_set_parent() below.
2030 */
2031
2032 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
2033 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2034 clk_core_prepare_enable(old_parent);
2035 clk_core_prepare_enable(parent);
2036 }
2037
2038 /* migrate prepare count if > 0 */
2039 if (core->prepare_count) {
2040 clk_core_prepare_enable(parent);
2041 clk_core_enable_lock(core);
2042 }
2043
2044 /* update the clk tree topology */
2045 flags = clk_enable_lock();
2046 clk_reparent(core, parent);
2047 clk_enable_unlock(flags);
2048
2049 return old_parent;
2050}
2051
2052static void __clk_set_parent_after(struct clk_core *core,
2053 struct clk_core *parent,
2054 struct clk_core *old_parent)
2055{
2056 /*
2057 * Finish the migration of prepare state and undo the changes done
2058 * for preventing a race with clk_enable().
2059 */
2060 if (core->prepare_count) {
2061 clk_core_disable_lock(core);
2062 clk_core_disable_unprepare(old_parent);
2063 }
2064
2065 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
2066 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2067 clk_core_disable_unprepare(parent);
2068 clk_core_disable_unprepare(old_parent);
2069 }
2070}
2071
2072static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
2073 u8 p_index)
2074{
2075 unsigned long flags;
2076 int ret = 0;
2077 struct clk_core *old_parent;
2078
2079 old_parent = __clk_set_parent_before(core, parent);
2080
2081 trace_clk_set_parent(core, parent);
2082
2083 /* change clock input source */
2084 if (parent && core->ops->set_parent)
2085 ret = core->ops->set_parent(core->hw, p_index);
2086
2087 trace_clk_set_parent_complete(core, parent);
2088
2089 if (ret) {
2090 flags = clk_enable_lock();
2091 clk_reparent(core, old_parent);
2092 clk_enable_unlock(flags);
2093
2094 __clk_set_parent_after(core, old_parent, parent);
2095
2096 return ret;
2097 }
2098
2099 __clk_set_parent_after(core, parent, old_parent);
2100
2101 return 0;
2102}
2103
2104/**
2105 * __clk_speculate_rates
2106 * @core: first clk in the subtree
2107 * @parent_rate: the "future" rate of clk's parent
2108 *
2109 * Walks the subtree of clks starting with clk, speculating rates as it
2110 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
2111 *
2112 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
2113 * pre-rate change notifications and returns early if no clks in the
2114 * subtree have subscribed to the notifications. Note that if a clk does not
2115 * implement the .recalc_rate callback then it is assumed that the clock will
2116 * take on the rate of its parent.
2117 */
2118static int __clk_speculate_rates(struct clk_core *core,
2119 unsigned long parent_rate)
2120{
2121 struct clk_core *child;
2122 unsigned long new_rate;
2123 int ret = NOTIFY_DONE;
2124
2125 lockdep_assert_held(&prepare_lock);
2126
2127 new_rate = clk_recalc(core, parent_rate);
2128
2129 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
2130 if (core->notifier_count)
2131 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
2132
2133 if (ret & NOTIFY_STOP_MASK) {
2134 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
2135 __func__, core->name, ret);
2136 goto out;
2137 }
2138
2139 hlist_for_each_entry(child, &core->children, child_node) {
2140 ret = __clk_speculate_rates(child, new_rate);
2141 if (ret & NOTIFY_STOP_MASK)
2142 break;
2143 }
2144
2145out:
2146 return ret;
2147}
2148
2149static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
2150 struct clk_core *new_parent, u8 p_index)
2151{
2152 struct clk_core *child;
2153
2154 core->new_rate = new_rate;
2155 core->new_parent = new_parent;
2156 core->new_parent_index = p_index;
2157 /* include clk in new parent's PRE_RATE_CHANGE notifications */
2158 core->new_child = NULL;
2159 if (new_parent && new_parent != core->parent)
2160 new_parent->new_child = core;
2161
2162 hlist_for_each_entry(child, &core->children, child_node) {
2163 child->new_rate = clk_recalc(child, new_rate);
2164 clk_calc_subtree(child, child->new_rate, NULL, 0);
2165 }
2166}
2167
2168/*
2169 * calculate the new rates returning the topmost clock that has to be
2170 * changed.
2171 */
2172static struct clk_core *clk_calc_new_rates(struct clk_core *core,
2173 unsigned long rate)
2174{
2175 struct clk_core *top = core;
2176 struct clk_core *old_parent, *parent;
2177 unsigned long best_parent_rate = 0;
2178 unsigned long new_rate;
2179 unsigned long min_rate;
2180 unsigned long max_rate;
2181 int p_index = 0;
2182 long ret;
2183
2184 /* sanity */
2185 if (IS_ERR_OR_NULL(core))
2186 return NULL;
2187
2188 /* save parent rate, if it exists */
2189 parent = old_parent = core->parent;
2190 if (parent)
2191 best_parent_rate = parent->rate;
2192
2193 clk_core_get_boundaries(core, &min_rate, &max_rate);
2194
2195 /* find the closest rate and parent clk/rate */
2196 if (clk_core_can_round(core)) {
2197 struct clk_rate_request req;
2198
2199 clk_core_init_rate_req(core, &req, rate);
2200
2201 trace_clk_rate_request_start(&req);
2202
2203 ret = clk_core_determine_round_nolock(core, &req);
2204 if (ret < 0)
2205 return NULL;
2206
2207 trace_clk_rate_request_done(&req);
2208
2209 best_parent_rate = req.best_parent_rate;
2210 new_rate = req.rate;
2211 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
2212
2213 if (new_rate < min_rate || new_rate > max_rate)
2214 return NULL;
2215 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
2216 /* pass-through clock without adjustable parent */
2217 core->new_rate = core->rate;
2218 return NULL;
2219 } else {
2220 /* pass-through clock with adjustable parent */
2221 top = clk_calc_new_rates(parent, rate);
2222 new_rate = parent->new_rate;
2223 goto out;
2224 }
2225
2226 /* some clocks must be gated to change parent */
2227 if (parent != old_parent &&
2228 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
2229 pr_debug("%s: %s not gated but wants to reparent\n",
2230 __func__, core->name);
2231 return NULL;
2232 }
2233
2234 /* try finding the new parent index */
2235 if (parent && core->num_parents > 1) {
2236 p_index = clk_fetch_parent_index(core, parent);
2237 if (p_index < 0) {
2238 pr_debug("%s: clk %s can not be parent of clk %s\n",
2239 __func__, parent->name, core->name);
2240 return NULL;
2241 }
2242 }
2243
2244 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2245 best_parent_rate != parent->rate)
2246 top = clk_calc_new_rates(parent, best_parent_rate);
2247
2248out:
2249 clk_calc_subtree(core, new_rate, parent, p_index);
2250
2251 return top;
2252}
2253
2254/*
2255 * Notify about rate changes in a subtree. Always walk down the whole tree
2256 * so that in case of an error we can walk down the whole tree again and
2257 * abort the change.
2258 */
2259static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2260 unsigned long event)
2261{
2262 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2263 int ret = NOTIFY_DONE;
2264
2265 if (core->rate == core->new_rate)
2266 return NULL;
2267
2268 if (core->notifier_count) {
2269 ret = __clk_notify(core, event, core->rate, core->new_rate);
2270 if (ret & NOTIFY_STOP_MASK)
2271 fail_clk = core;
2272 }
2273
2274 hlist_for_each_entry(child, &core->children, child_node) {
2275 /* Skip children who will be reparented to another clock */
2276 if (child->new_parent && child->new_parent != core)
2277 continue;
2278 tmp_clk = clk_propagate_rate_change(child, event);
2279 if (tmp_clk)
2280 fail_clk = tmp_clk;
2281 }
2282
2283 /* handle the new child who might not be in core->children yet */
2284 if (core->new_child) {
2285 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2286 if (tmp_clk)
2287 fail_clk = tmp_clk;
2288 }
2289
2290 return fail_clk;
2291}
2292
2293/*
2294 * walk down a subtree and set the new rates notifying the rate
2295 * change on the way
2296 */
2297static void clk_change_rate(struct clk_core *core)
2298{
2299 struct clk_core *child;
2300 struct hlist_node *tmp;
2301 unsigned long old_rate;
2302 unsigned long best_parent_rate = 0;
2303 bool skip_set_rate = false;
2304 struct clk_core *old_parent;
2305 struct clk_core *parent = NULL;
2306
2307 old_rate = core->rate;
2308
2309 if (core->new_parent) {
2310 parent = core->new_parent;
2311 best_parent_rate = core->new_parent->rate;
2312 } else if (core->parent) {
2313 parent = core->parent;
2314 best_parent_rate = core->parent->rate;
2315 }
2316
2317 if (clk_pm_runtime_get(core))
2318 return;
2319
2320 if (core->flags & CLK_SET_RATE_UNGATE) {
2321 clk_core_prepare(core);
2322 clk_core_enable_lock(core);
2323 }
2324
2325 if (core->new_parent && core->new_parent != core->parent) {
2326 old_parent = __clk_set_parent_before(core, core->new_parent);
2327 trace_clk_set_parent(core, core->new_parent);
2328
2329 if (core->ops->set_rate_and_parent) {
2330 skip_set_rate = true;
2331 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2332 best_parent_rate,
2333 core->new_parent_index);
2334 } else if (core->ops->set_parent) {
2335 core->ops->set_parent(core->hw, core->new_parent_index);
2336 }
2337
2338 trace_clk_set_parent_complete(core, core->new_parent);
2339 __clk_set_parent_after(core, core->new_parent, old_parent);
2340 }
2341
2342 if (core->flags & CLK_OPS_PARENT_ENABLE)
2343 clk_core_prepare_enable(parent);
2344
2345 trace_clk_set_rate(core, core->new_rate);
2346
2347 if (!skip_set_rate && core->ops->set_rate)
2348 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2349
2350 trace_clk_set_rate_complete(core, core->new_rate);
2351
2352 core->rate = clk_recalc(core, best_parent_rate);
2353
2354 if (core->flags & CLK_SET_RATE_UNGATE) {
2355 clk_core_disable_lock(core);
2356 clk_core_unprepare(core);
2357 }
2358
2359 if (core->flags & CLK_OPS_PARENT_ENABLE)
2360 clk_core_disable_unprepare(parent);
2361
2362 if (core->notifier_count && old_rate != core->rate)
2363 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2364
2365 if (core->flags & CLK_RECALC_NEW_RATES)
2366 (void)clk_calc_new_rates(core, core->new_rate);
2367
2368 /*
2369 * Use safe iteration, as change_rate can actually swap parents
2370 * for certain clock types.
2371 */
2372 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2373 /* Skip children who will be reparented to another clock */
2374 if (child->new_parent && child->new_parent != core)
2375 continue;
2376 clk_change_rate(child);
2377 }
2378
2379 /* handle the new child who might not be in core->children yet */
2380 if (core->new_child)
2381 clk_change_rate(core->new_child);
2382
2383 clk_pm_runtime_put(core);
2384}
2385
2386static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2387 unsigned long req_rate)
2388{
2389 int ret, cnt;
2390 struct clk_rate_request req;
2391
2392 lockdep_assert_held(&prepare_lock);
2393
2394 if (!core)
2395 return 0;
2396
2397 /* simulate what the rate would be if it could be freely set */
2398 cnt = clk_core_rate_nuke_protect(core);
2399 if (cnt < 0)
2400 return cnt;
2401
2402 clk_core_init_rate_req(core, &req, req_rate);
2403
2404 trace_clk_rate_request_start(&req);
2405
2406 ret = clk_core_round_rate_nolock(core, &req);
2407
2408 trace_clk_rate_request_done(&req);
2409
2410 /* restore the protection */
2411 clk_core_rate_restore_protect(core, cnt);
2412
2413 return ret ? 0 : req.rate;
2414}
2415
2416static int clk_core_set_rate_nolock(struct clk_core *core,
2417 unsigned long req_rate)
2418{
2419 struct clk_core *top, *fail_clk;
2420 unsigned long rate;
2421 int ret;
2422
2423 if (!core)
2424 return 0;
2425
2426 rate = clk_core_req_round_rate_nolock(core, req_rate);
2427
2428 /* bail early if nothing to do */
2429 if (rate == clk_core_get_rate_nolock(core))
2430 return 0;
2431
2432 /* fail on a direct rate set of a protected provider */
2433 if (clk_core_rate_is_protected(core))
2434 return -EBUSY;
2435
2436 /* calculate new rates and get the topmost changed clock */
2437 top = clk_calc_new_rates(core, req_rate);
2438 if (!top)
2439 return -EINVAL;
2440
2441 ret = clk_pm_runtime_get(core);
2442 if (ret)
2443 return ret;
2444
2445 /* notify that we are about to change rates */
2446 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2447 if (fail_clk) {
2448 pr_debug("%s: failed to set %s rate\n", __func__,
2449 fail_clk->name);
2450 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2451 ret = -EBUSY;
2452 goto err;
2453 }
2454
2455 /* change the rates */
2456 clk_change_rate(top);
2457
2458 core->req_rate = req_rate;
2459err:
2460 clk_pm_runtime_put(core);
2461
2462 return ret;
2463}
2464
2465/**
2466 * clk_set_rate - specify a new rate for clk
2467 * @clk: the clk whose rate is being changed
2468 * @rate: the new rate for clk
2469 *
2470 * In the simplest case clk_set_rate will only adjust the rate of clk.
2471 *
2472 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2473 * propagate up to clk's parent; whether or not this happens depends on the
2474 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2475 * after calling .round_rate then upstream parent propagation is ignored. If
2476 * *parent_rate comes back with a new rate for clk's parent then we propagate
2477 * up to clk's parent and set its rate. Upward propagation will continue
2478 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2479 * .round_rate stops requesting changes to clk's parent_rate.
2480 *
2481 * Rate changes are accomplished via tree traversal that also recalculates the
2482 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2483 *
2484 * Returns 0 on success, -EERROR otherwise.
2485 */
2486int clk_set_rate(struct clk *clk, unsigned long rate)
2487{
2488 int ret;
2489
2490 if (!clk)
2491 return 0;
2492
2493 /* prevent racing with updates to the clock topology */
2494 clk_prepare_lock();
2495
2496 if (clk->exclusive_count)
2497 clk_core_rate_unprotect(clk->core);
2498
2499 ret = clk_core_set_rate_nolock(clk->core, rate);
2500
2501 if (clk->exclusive_count)
2502 clk_core_rate_protect(clk->core);
2503
2504 clk_prepare_unlock();
2505
2506 return ret;
2507}
2508EXPORT_SYMBOL_GPL(clk_set_rate);
2509
2510/**
2511 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2512 * @clk: the clk whose rate is being changed
2513 * @rate: the new rate for clk
2514 *
2515 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2516 * within a critical section
2517 *
2518 * This can be used initially to ensure that at least 1 consumer is
2519 * satisfied when several consumers are competing for exclusivity over the
2520 * same clock provider.
2521 *
2522 * The exclusivity is not applied if setting the rate failed.
2523 *
2524 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2525 * clk_rate_exclusive_put().
2526 *
2527 * Returns 0 on success, -EERROR otherwise.
2528 */
2529int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2530{
2531 int ret;
2532
2533 if (!clk)
2534 return 0;
2535
2536 /* prevent racing with updates to the clock topology */
2537 clk_prepare_lock();
2538
2539 /*
2540 * The temporary protection removal is not here, on purpose
2541 * This function is meant to be used instead of clk_rate_protect,
2542 * so before the consumer code path protect the clock provider
2543 */
2544
2545 ret = clk_core_set_rate_nolock(clk->core, rate);
2546 if (!ret) {
2547 clk_core_rate_protect(clk->core);
2548 clk->exclusive_count++;
2549 }
2550
2551 clk_prepare_unlock();
2552
2553 return ret;
2554}
2555EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2556
2557static int clk_set_rate_range_nolock(struct clk *clk,
2558 unsigned long min,
2559 unsigned long max)
2560{
2561 int ret = 0;
2562 unsigned long old_min, old_max, rate;
2563
2564 lockdep_assert_held(&prepare_lock);
2565
2566 if (!clk)
2567 return 0;
2568
2569 trace_clk_set_rate_range(clk->core, min, max);
2570
2571 if (min > max) {
2572 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2573 __func__, clk->core->name, clk->dev_id, clk->con_id,
2574 min, max);
2575 return -EINVAL;
2576 }
2577
2578 if (clk->exclusive_count)
2579 clk_core_rate_unprotect(clk->core);
2580
2581 /* Save the current values in case we need to rollback the change */
2582 old_min = clk->min_rate;
2583 old_max = clk->max_rate;
2584 clk->min_rate = min;
2585 clk->max_rate = max;
2586
2587 if (!clk_core_check_boundaries(clk->core, min, max)) {
2588 ret = -EINVAL;
2589 goto out;
2590 }
2591
2592 rate = clk->core->req_rate;
2593 if (clk->core->flags & CLK_GET_RATE_NOCACHE)
2594 rate = clk_core_get_rate_recalc(clk->core);
2595
2596 /*
2597 * Since the boundaries have been changed, let's give the
2598 * opportunity to the provider to adjust the clock rate based on
2599 * the new boundaries.
2600 *
2601 * We also need to handle the case where the clock is currently
2602 * outside of the boundaries. Clamping the last requested rate
2603 * to the current minimum and maximum will also handle this.
2604 *
2605 * FIXME:
2606 * There is a catch. It may fail for the usual reason (clock
2607 * broken, clock protected, etc) but also because:
2608 * - round_rate() was not favorable and fell on the wrong
2609 * side of the boundary
2610 * - the determine_rate() callback does not really check for
2611 * this corner case when determining the rate
2612 */
2613 rate = clamp(rate, min, max);
2614 ret = clk_core_set_rate_nolock(clk->core, rate);
2615 if (ret) {
2616 /* rollback the changes */
2617 clk->min_rate = old_min;
2618 clk->max_rate = old_max;
2619 }
2620
2621out:
2622 if (clk->exclusive_count)
2623 clk_core_rate_protect(clk->core);
2624
2625 return ret;
2626}
2627
2628/**
2629 * clk_set_rate_range - set a rate range for a clock source
2630 * @clk: clock source
2631 * @min: desired minimum clock rate in Hz, inclusive
2632 * @max: desired maximum clock rate in Hz, inclusive
2633 *
2634 * Return: 0 for success or negative errno on failure.
2635 */
2636int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2637{
2638 int ret;
2639
2640 if (!clk)
2641 return 0;
2642
2643 clk_prepare_lock();
2644
2645 ret = clk_set_rate_range_nolock(clk, min, max);
2646
2647 clk_prepare_unlock();
2648
2649 return ret;
2650}
2651EXPORT_SYMBOL_GPL(clk_set_rate_range);
2652
2653/**
2654 * clk_set_min_rate - set a minimum clock rate for a clock source
2655 * @clk: clock source
2656 * @rate: desired minimum clock rate in Hz, inclusive
2657 *
2658 * Returns success (0) or negative errno.
2659 */
2660int clk_set_min_rate(struct clk *clk, unsigned long rate)
2661{
2662 if (!clk)
2663 return 0;
2664
2665 trace_clk_set_min_rate(clk->core, rate);
2666
2667 return clk_set_rate_range(clk, rate, clk->max_rate);
2668}
2669EXPORT_SYMBOL_GPL(clk_set_min_rate);
2670
2671/**
2672 * clk_set_max_rate - set a maximum clock rate for a clock source
2673 * @clk: clock source
2674 * @rate: desired maximum clock rate in Hz, inclusive
2675 *
2676 * Returns success (0) or negative errno.
2677 */
2678int clk_set_max_rate(struct clk *clk, unsigned long rate)
2679{
2680 if (!clk)
2681 return 0;
2682
2683 trace_clk_set_max_rate(clk->core, rate);
2684
2685 return clk_set_rate_range(clk, clk->min_rate, rate);
2686}
2687EXPORT_SYMBOL_GPL(clk_set_max_rate);
2688
2689/**
2690 * clk_get_parent - return the parent of a clk
2691 * @clk: the clk whose parent gets returned
2692 *
2693 * Simply returns clk->parent. Returns NULL if clk is NULL.
2694 */
2695struct clk *clk_get_parent(struct clk *clk)
2696{
2697 struct clk *parent;
2698
2699 if (!clk)
2700 return NULL;
2701
2702 clk_prepare_lock();
2703 /* TODO: Create a per-user clk and change callers to call clk_put */
2704 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2705 clk_prepare_unlock();
2706
2707 return parent;
2708}
2709EXPORT_SYMBOL_GPL(clk_get_parent);
2710
2711static struct clk_core *__clk_init_parent(struct clk_core *core)
2712{
2713 u8 index = 0;
2714
2715 if (core->num_parents > 1 && core->ops->get_parent)
2716 index = core->ops->get_parent(core->hw);
2717
2718 return clk_core_get_parent_by_index(core, index);
2719}
2720
2721static void clk_core_reparent(struct clk_core *core,
2722 struct clk_core *new_parent)
2723{
2724 clk_reparent(core, new_parent);
2725 __clk_recalc_accuracies(core);
2726 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2727}
2728
2729void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2730{
2731 if (!hw)
2732 return;
2733
2734 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2735}
2736
2737/**
2738 * clk_has_parent - check if a clock is a possible parent for another
2739 * @clk: clock source
2740 * @parent: parent clock source
2741 *
2742 * This function can be used in drivers that need to check that a clock can be
2743 * the parent of another without actually changing the parent.
2744 *
2745 * Returns true if @parent is a possible parent for @clk, false otherwise.
2746 */
2747bool clk_has_parent(const struct clk *clk, const struct clk *parent)
2748{
2749 /* NULL clocks should be nops, so return success if either is NULL. */
2750 if (!clk || !parent)
2751 return true;
2752
2753 return clk_core_has_parent(clk->core, parent->core);
2754}
2755EXPORT_SYMBOL_GPL(clk_has_parent);
2756
2757static int clk_core_set_parent_nolock(struct clk_core *core,
2758 struct clk_core *parent)
2759{
2760 int ret = 0;
2761 int p_index = 0;
2762 unsigned long p_rate = 0;
2763
2764 lockdep_assert_held(&prepare_lock);
2765
2766 if (!core)
2767 return 0;
2768
2769 if (core->parent == parent)
2770 return 0;
2771
2772 /* verify ops for multi-parent clks */
2773 if (core->num_parents > 1 && !core->ops->set_parent)
2774 return -EPERM;
2775
2776 /* check that we are allowed to re-parent if the clock is in use */
2777 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2778 return -EBUSY;
2779
2780 if (clk_core_rate_is_protected(core))
2781 return -EBUSY;
2782
2783 /* try finding the new parent index */
2784 if (parent) {
2785 p_index = clk_fetch_parent_index(core, parent);
2786 if (p_index < 0) {
2787 pr_debug("%s: clk %s can not be parent of clk %s\n",
2788 __func__, parent->name, core->name);
2789 return p_index;
2790 }
2791 p_rate = parent->rate;
2792 }
2793
2794 ret = clk_pm_runtime_get(core);
2795 if (ret)
2796 return ret;
2797
2798 /* propagate PRE_RATE_CHANGE notifications */
2799 ret = __clk_speculate_rates(core, p_rate);
2800
2801 /* abort if a driver objects */
2802 if (ret & NOTIFY_STOP_MASK)
2803 goto runtime_put;
2804
2805 /* do the re-parent */
2806 ret = __clk_set_parent(core, parent, p_index);
2807
2808 /* propagate rate an accuracy recalculation accordingly */
2809 if (ret) {
2810 __clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
2811 } else {
2812 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2813 __clk_recalc_accuracies(core);
2814 }
2815
2816runtime_put:
2817 clk_pm_runtime_put(core);
2818
2819 return ret;
2820}
2821
2822int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2823{
2824 return clk_core_set_parent_nolock(hw->core, parent->core);
2825}
2826EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2827
2828/**
2829 * clk_set_parent - switch the parent of a mux clk
2830 * @clk: the mux clk whose input we are switching
2831 * @parent: the new input to clk
2832 *
2833 * Re-parent clk to use parent as its new input source. If clk is in
2834 * prepared state, the clk will get enabled for the duration of this call. If
2835 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2836 * that, the reparenting is glitchy in hardware, etc), use the
2837 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2838 *
2839 * After successfully changing clk's parent clk_set_parent will update the
2840 * clk topology, sysfs topology and propagate rate recalculation via
2841 * __clk_recalc_rates.
2842 *
2843 * Returns 0 on success, -EERROR otherwise.
2844 */
2845int clk_set_parent(struct clk *clk, struct clk *parent)
2846{
2847 int ret;
2848
2849 if (!clk)
2850 return 0;
2851
2852 clk_prepare_lock();
2853
2854 if (clk->exclusive_count)
2855 clk_core_rate_unprotect(clk->core);
2856
2857 ret = clk_core_set_parent_nolock(clk->core,
2858 parent ? parent->core : NULL);
2859
2860 if (clk->exclusive_count)
2861 clk_core_rate_protect(clk->core);
2862
2863 clk_prepare_unlock();
2864
2865 return ret;
2866}
2867EXPORT_SYMBOL_GPL(clk_set_parent);
2868
2869static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2870{
2871 int ret = -EINVAL;
2872
2873 lockdep_assert_held(&prepare_lock);
2874
2875 if (!core)
2876 return 0;
2877
2878 if (clk_core_rate_is_protected(core))
2879 return -EBUSY;
2880
2881 trace_clk_set_phase(core, degrees);
2882
2883 if (core->ops->set_phase) {
2884 ret = core->ops->set_phase(core->hw, degrees);
2885 if (!ret)
2886 core->phase = degrees;
2887 }
2888
2889 trace_clk_set_phase_complete(core, degrees);
2890
2891 return ret;
2892}
2893
2894/**
2895 * clk_set_phase - adjust the phase shift of a clock signal
2896 * @clk: clock signal source
2897 * @degrees: number of degrees the signal is shifted
2898 *
2899 * Shifts the phase of a clock signal by the specified
2900 * degrees. Returns 0 on success, -EERROR otherwise.
2901 *
2902 * This function makes no distinction about the input or reference
2903 * signal that we adjust the clock signal phase against. For example
2904 * phase locked-loop clock signal generators we may shift phase with
2905 * respect to feedback clock signal input, but for other cases the
2906 * clock phase may be shifted with respect to some other, unspecified
2907 * signal.
2908 *
2909 * Additionally the concept of phase shift does not propagate through
2910 * the clock tree hierarchy, which sets it apart from clock rates and
2911 * clock accuracy. A parent clock phase attribute does not have an
2912 * impact on the phase attribute of a child clock.
2913 */
2914int clk_set_phase(struct clk *clk, int degrees)
2915{
2916 int ret;
2917
2918 if (!clk)
2919 return 0;
2920
2921 /* sanity check degrees */
2922 degrees %= 360;
2923 if (degrees < 0)
2924 degrees += 360;
2925
2926 clk_prepare_lock();
2927
2928 if (clk->exclusive_count)
2929 clk_core_rate_unprotect(clk->core);
2930
2931 ret = clk_core_set_phase_nolock(clk->core, degrees);
2932
2933 if (clk->exclusive_count)
2934 clk_core_rate_protect(clk->core);
2935
2936 clk_prepare_unlock();
2937
2938 return ret;
2939}
2940EXPORT_SYMBOL_GPL(clk_set_phase);
2941
2942static int clk_core_get_phase(struct clk_core *core)
2943{
2944 int ret;
2945
2946 lockdep_assert_held(&prepare_lock);
2947 if (!core->ops->get_phase)
2948 return 0;
2949
2950 /* Always try to update cached phase if possible */
2951 ret = core->ops->get_phase(core->hw);
2952 if (ret >= 0)
2953 core->phase = ret;
2954
2955 return ret;
2956}
2957
2958/**
2959 * clk_get_phase - return the phase shift of a clock signal
2960 * @clk: clock signal source
2961 *
2962 * Returns the phase shift of a clock node in degrees, otherwise returns
2963 * -EERROR.
2964 */
2965int clk_get_phase(struct clk *clk)
2966{
2967 int ret;
2968
2969 if (!clk)
2970 return 0;
2971
2972 clk_prepare_lock();
2973 ret = clk_core_get_phase(clk->core);
2974 clk_prepare_unlock();
2975
2976 return ret;
2977}
2978EXPORT_SYMBOL_GPL(clk_get_phase);
2979
2980static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
2981{
2982 /* Assume a default value of 50% */
2983 core->duty.num = 1;
2984 core->duty.den = 2;
2985}
2986
2987static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
2988
2989static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
2990{
2991 struct clk_duty *duty = &core->duty;
2992 int ret = 0;
2993
2994 if (!core->ops->get_duty_cycle)
2995 return clk_core_update_duty_cycle_parent_nolock(core);
2996
2997 ret = core->ops->get_duty_cycle(core->hw, duty);
2998 if (ret)
2999 goto reset;
3000
3001 /* Don't trust the clock provider too much */
3002 if (duty->den == 0 || duty->num > duty->den) {
3003 ret = -EINVAL;
3004 goto reset;
3005 }
3006
3007 return 0;
3008
3009reset:
3010 clk_core_reset_duty_cycle_nolock(core);
3011 return ret;
3012}
3013
3014static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
3015{
3016 int ret = 0;
3017
3018 if (core->parent &&
3019 core->flags & CLK_DUTY_CYCLE_PARENT) {
3020 ret = clk_core_update_duty_cycle_nolock(core->parent);
3021 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3022 } else {
3023 clk_core_reset_duty_cycle_nolock(core);
3024 }
3025
3026 return ret;
3027}
3028
3029static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3030 struct clk_duty *duty);
3031
3032static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
3033 struct clk_duty *duty)
3034{
3035 int ret;
3036
3037 lockdep_assert_held(&prepare_lock);
3038
3039 if (clk_core_rate_is_protected(core))
3040 return -EBUSY;
3041
3042 trace_clk_set_duty_cycle(core, duty);
3043
3044 if (!core->ops->set_duty_cycle)
3045 return clk_core_set_duty_cycle_parent_nolock(core, duty);
3046
3047 ret = core->ops->set_duty_cycle(core->hw, duty);
3048 if (!ret)
3049 memcpy(&core->duty, duty, sizeof(*duty));
3050
3051 trace_clk_set_duty_cycle_complete(core, duty);
3052
3053 return ret;
3054}
3055
3056static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3057 struct clk_duty *duty)
3058{
3059 int ret = 0;
3060
3061 if (core->parent &&
3062 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
3063 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
3064 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3065 }
3066
3067 return ret;
3068}
3069
3070/**
3071 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
3072 * @clk: clock signal source
3073 * @num: numerator of the duty cycle ratio to be applied
3074 * @den: denominator of the duty cycle ratio to be applied
3075 *
3076 * Apply the duty cycle ratio if the ratio is valid and the clock can
3077 * perform this operation
3078 *
3079 * Returns (0) on success, a negative errno otherwise.
3080 */
3081int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
3082{
3083 int ret;
3084 struct clk_duty duty;
3085
3086 if (!clk)
3087 return 0;
3088
3089 /* sanity check the ratio */
3090 if (den == 0 || num > den)
3091 return -EINVAL;
3092
3093 duty.num = num;
3094 duty.den = den;
3095
3096 clk_prepare_lock();
3097
3098 if (clk->exclusive_count)
3099 clk_core_rate_unprotect(clk->core);
3100
3101 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
3102
3103 if (clk->exclusive_count)
3104 clk_core_rate_protect(clk->core);
3105
3106 clk_prepare_unlock();
3107
3108 return ret;
3109}
3110EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
3111
3112static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
3113 unsigned int scale)
3114{
3115 struct clk_duty *duty = &core->duty;
3116 int ret;
3117
3118 clk_prepare_lock();
3119
3120 ret = clk_core_update_duty_cycle_nolock(core);
3121 if (!ret)
3122 ret = mult_frac(scale, duty->num, duty->den);
3123
3124 clk_prepare_unlock();
3125
3126 return ret;
3127}
3128
3129/**
3130 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
3131 * @clk: clock signal source
3132 * @scale: scaling factor to be applied to represent the ratio as an integer
3133 *
3134 * Returns the duty cycle ratio of a clock node multiplied by the provided
3135 * scaling factor, or negative errno on error.
3136 */
3137int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
3138{
3139 if (!clk)
3140 return 0;
3141
3142 return clk_core_get_scaled_duty_cycle(clk->core, scale);
3143}
3144EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
3145
3146/**
3147 * clk_is_match - check if two clk's point to the same hardware clock
3148 * @p: clk compared against q
3149 * @q: clk compared against p
3150 *
3151 * Returns true if the two struct clk pointers both point to the same hardware
3152 * clock node. Put differently, returns true if struct clk *p and struct clk *q
3153 * share the same struct clk_core object.
3154 *
3155 * Returns false otherwise. Note that two NULL clks are treated as matching.
3156 */
3157bool clk_is_match(const struct clk *p, const struct clk *q)
3158{
3159 /* trivial case: identical struct clk's or both NULL */
3160 if (p == q)
3161 return true;
3162
3163 /* true if clk->core pointers match. Avoid dereferencing garbage */
3164 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
3165 if (p->core == q->core)
3166 return true;
3167
3168 return false;
3169}
3170EXPORT_SYMBOL_GPL(clk_is_match);
3171
3172/*** debugfs support ***/
3173
3174#ifdef CONFIG_DEBUG_FS
3175#include <linux/debugfs.h>
3176
3177static struct dentry *rootdir;
3178static int inited = 0;
3179static DEFINE_MUTEX(clk_debug_lock);
3180static HLIST_HEAD(clk_debug_list);
3181
3182static struct hlist_head *orphan_list[] = {
3183 &clk_orphan_list,
3184 NULL,
3185};
3186
3187static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
3188 int level)
3189{
3190 int phase;
3191 struct clk *clk_user;
3192 int multi_node = 0;
3193
3194 seq_printf(s, "%*s%-*s %-7d %-8d %-8d %-11lu %-10lu ",
3195 level * 3 + 1, "",
3196 35 - level * 3, c->name,
3197 c->enable_count, c->prepare_count, c->protect_count,
3198 clk_core_get_rate_recalc(c),
3199 clk_core_get_accuracy_recalc(c));
3200
3201 phase = clk_core_get_phase(c);
3202 if (phase >= 0)
3203 seq_printf(s, "%-5d", phase);
3204 else
3205 seq_puts(s, "-----");
3206
3207 seq_printf(s, " %-6d", clk_core_get_scaled_duty_cycle(c, 100000));
3208
3209 if (c->ops->is_enabled)
3210 seq_printf(s, " %5c ", clk_core_is_enabled(c) ? 'Y' : 'N');
3211 else if (!c->ops->enable)
3212 seq_printf(s, " %5c ", 'Y');
3213 else
3214 seq_printf(s, " %5c ", '?');
3215
3216 hlist_for_each_entry(clk_user, &c->clks, clks_node) {
3217 seq_printf(s, "%*s%-*s %-25s\n",
3218 level * 3 + 2 + 105 * multi_node, "",
3219 30,
3220 clk_user->dev_id ? clk_user->dev_id : "deviceless",
3221 clk_user->con_id ? clk_user->con_id : "no_connection_id");
3222
3223 multi_node = 1;
3224 }
3225
3226}
3227
3228static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
3229 int level)
3230{
3231 struct clk_core *child;
3232
3233 clk_pm_runtime_get(c);
3234 clk_summary_show_one(s, c, level);
3235 clk_pm_runtime_put(c);
3236
3237 hlist_for_each_entry(child, &c->children, child_node)
3238 clk_summary_show_subtree(s, child, level + 1);
3239}
3240
3241static int clk_summary_show(struct seq_file *s, void *data)
3242{
3243 struct clk_core *c;
3244 struct hlist_head **lists = s->private;
3245
3246 seq_puts(s, " enable prepare protect duty hardware connection\n");
3247 seq_puts(s, " clock count count count rate accuracy phase cycle enable consumer id\n");
3248 seq_puts(s, "---------------------------------------------------------------------------------------------------------------------------------------------\n");
3249
3250
3251 clk_prepare_lock();
3252
3253 for (; *lists; lists++)
3254 hlist_for_each_entry(c, *lists, child_node)
3255 clk_summary_show_subtree(s, c, 0);
3256
3257 clk_prepare_unlock();
3258
3259 return 0;
3260}
3261DEFINE_SHOW_ATTRIBUTE(clk_summary);
3262
3263static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
3264{
3265 int phase;
3266 unsigned long min_rate, max_rate;
3267
3268 clk_core_get_boundaries(c, &min_rate, &max_rate);
3269
3270 /* This should be JSON format, i.e. elements separated with a comma */
3271 seq_printf(s, "\"%s\": { ", c->name);
3272 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3273 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3274 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3275 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3276 seq_printf(s, "\"min_rate\": %lu,", min_rate);
3277 seq_printf(s, "\"max_rate\": %lu,", max_rate);
3278 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3279 phase = clk_core_get_phase(c);
3280 if (phase >= 0)
3281 seq_printf(s, "\"phase\": %d,", phase);
3282 seq_printf(s, "\"duty_cycle\": %u",
3283 clk_core_get_scaled_duty_cycle(c, 100000));
3284}
3285
3286static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3287{
3288 struct clk_core *child;
3289
3290 clk_dump_one(s, c, level);
3291
3292 hlist_for_each_entry(child, &c->children, child_node) {
3293 seq_putc(s, ',');
3294 clk_dump_subtree(s, child, level + 1);
3295 }
3296
3297 seq_putc(s, '}');
3298}
3299
3300static int clk_dump_show(struct seq_file *s, void *data)
3301{
3302 struct clk_core *c;
3303 bool first_node = true;
3304 struct hlist_head **lists = s->private;
3305
3306 seq_putc(s, '{');
3307 clk_prepare_lock();
3308
3309 for (; *lists; lists++) {
3310 hlist_for_each_entry(c, *lists, child_node) {
3311 if (!first_node)
3312 seq_putc(s, ',');
3313 first_node = false;
3314 clk_dump_subtree(s, c, 0);
3315 }
3316 }
3317
3318 clk_prepare_unlock();
3319
3320 seq_puts(s, "}\n");
3321 return 0;
3322}
3323DEFINE_SHOW_ATTRIBUTE(clk_dump);
3324
3325#undef CLOCK_ALLOW_WRITE_DEBUGFS
3326#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3327/*
3328 * This can be dangerous, therefore don't provide any real compile time
3329 * configuration option for this feature.
3330 * People who want to use this will need to modify the source code directly.
3331 */
3332static int clk_rate_set(void *data, u64 val)
3333{
3334 struct clk_core *core = data;
3335 int ret;
3336
3337 clk_prepare_lock();
3338 ret = clk_core_set_rate_nolock(core, val);
3339 clk_prepare_unlock();
3340
3341 return ret;
3342}
3343
3344#define clk_rate_mode 0644
3345
3346static int clk_phase_set(void *data, u64 val)
3347{
3348 struct clk_core *core = data;
3349 int degrees = do_div(val, 360);
3350 int ret;
3351
3352 clk_prepare_lock();
3353 ret = clk_core_set_phase_nolock(core, degrees);
3354 clk_prepare_unlock();
3355
3356 return ret;
3357}
3358
3359#define clk_phase_mode 0644
3360
3361static int clk_prepare_enable_set(void *data, u64 val)
3362{
3363 struct clk_core *core = data;
3364 int ret = 0;
3365
3366 if (val)
3367 ret = clk_prepare_enable(core->hw->clk);
3368 else
3369 clk_disable_unprepare(core->hw->clk);
3370
3371 return ret;
3372}
3373
3374static int clk_prepare_enable_get(void *data, u64 *val)
3375{
3376 struct clk_core *core = data;
3377
3378 *val = core->enable_count && core->prepare_count;
3379 return 0;
3380}
3381
3382DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3383 clk_prepare_enable_set, "%llu\n");
3384
3385#else
3386#define clk_rate_set NULL
3387#define clk_rate_mode 0444
3388
3389#define clk_phase_set NULL
3390#define clk_phase_mode 0644
3391#endif
3392
3393static int clk_rate_get(void *data, u64 *val)
3394{
3395 struct clk_core *core = data;
3396
3397 clk_prepare_lock();
3398 *val = clk_core_get_rate_recalc(core);
3399 clk_prepare_unlock();
3400
3401 return 0;
3402}
3403
3404DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3405
3406static int clk_phase_get(void *data, u64 *val)
3407{
3408 struct clk_core *core = data;
3409
3410 *val = core->phase;
3411 return 0;
3412}
3413
3414DEFINE_DEBUGFS_ATTRIBUTE(clk_phase_fops, clk_phase_get, clk_phase_set, "%llu\n");
3415
3416static const struct {
3417 unsigned long flag;
3418 const char *name;
3419} clk_flags[] = {
3420#define ENTRY(f) { f, #f }
3421 ENTRY(CLK_SET_RATE_GATE),
3422 ENTRY(CLK_SET_PARENT_GATE),
3423 ENTRY(CLK_SET_RATE_PARENT),
3424 ENTRY(CLK_IGNORE_UNUSED),
3425 ENTRY(CLK_GET_RATE_NOCACHE),
3426 ENTRY(CLK_SET_RATE_NO_REPARENT),
3427 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3428 ENTRY(CLK_RECALC_NEW_RATES),
3429 ENTRY(CLK_SET_RATE_UNGATE),
3430 ENTRY(CLK_IS_CRITICAL),
3431 ENTRY(CLK_OPS_PARENT_ENABLE),
3432 ENTRY(CLK_DUTY_CYCLE_PARENT),
3433#undef ENTRY
3434};
3435
3436static int clk_flags_show(struct seq_file *s, void *data)
3437{
3438 struct clk_core *core = s->private;
3439 unsigned long flags = core->flags;
3440 unsigned int i;
3441
3442 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3443 if (flags & clk_flags[i].flag) {
3444 seq_printf(s, "%s\n", clk_flags[i].name);
3445 flags &= ~clk_flags[i].flag;
3446 }
3447 }
3448 if (flags) {
3449 /* Unknown flags */
3450 seq_printf(s, "0x%lx\n", flags);
3451 }
3452
3453 return 0;
3454}
3455DEFINE_SHOW_ATTRIBUTE(clk_flags);
3456
3457static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3458 unsigned int i, char terminator)
3459{
3460 struct clk_core *parent;
3461 const char *name = NULL;
3462
3463 /*
3464 * Go through the following options to fetch a parent's name.
3465 *
3466 * 1. Fetch the registered parent clock and use its name
3467 * 2. Use the global (fallback) name if specified
3468 * 3. Use the local fw_name if provided
3469 * 4. Fetch parent clock's clock-output-name if DT index was set
3470 *
3471 * This may still fail in some cases, such as when the parent is
3472 * specified directly via a struct clk_hw pointer, but it isn't
3473 * registered (yet).
3474 */
3475 parent = clk_core_get_parent_by_index(core, i);
3476 if (parent) {
3477 seq_puts(s, parent->name);
3478 } else if (core->parents[i].name) {
3479 seq_puts(s, core->parents[i].name);
3480 } else if (core->parents[i].fw_name) {
3481 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3482 } else {
3483 if (core->parents[i].index >= 0)
3484 name = of_clk_get_parent_name(core->of_node, core->parents[i].index);
3485 if (!name)
3486 name = "(missing)";
3487
3488 seq_puts(s, name);
3489 }
3490
3491 seq_putc(s, terminator);
3492}
3493
3494static int possible_parents_show(struct seq_file *s, void *data)
3495{
3496 struct clk_core *core = s->private;
3497 int i;
3498
3499 for (i = 0; i < core->num_parents - 1; i++)
3500 possible_parent_show(s, core, i, ' ');
3501
3502 possible_parent_show(s, core, i, '\n');
3503
3504 return 0;
3505}
3506DEFINE_SHOW_ATTRIBUTE(possible_parents);
3507
3508static int current_parent_show(struct seq_file *s, void *data)
3509{
3510 struct clk_core *core = s->private;
3511
3512 if (core->parent)
3513 seq_printf(s, "%s\n", core->parent->name);
3514
3515 return 0;
3516}
3517DEFINE_SHOW_ATTRIBUTE(current_parent);
3518
3519#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3520static ssize_t current_parent_write(struct file *file, const char __user *ubuf,
3521 size_t count, loff_t *ppos)
3522{
3523 struct seq_file *s = file->private_data;
3524 struct clk_core *core = s->private;
3525 struct clk_core *parent;
3526 u8 idx;
3527 int err;
3528
3529 err = kstrtou8_from_user(ubuf, count, 0, &idx);
3530 if (err < 0)
3531 return err;
3532
3533 parent = clk_core_get_parent_by_index(core, idx);
3534 if (!parent)
3535 return -ENOENT;
3536
3537 clk_prepare_lock();
3538 err = clk_core_set_parent_nolock(core, parent);
3539 clk_prepare_unlock();
3540 if (err)
3541 return err;
3542
3543 return count;
3544}
3545
3546static const struct file_operations current_parent_rw_fops = {
3547 .open = current_parent_open,
3548 .write = current_parent_write,
3549 .read = seq_read,
3550 .llseek = seq_lseek,
3551 .release = single_release,
3552};
3553#endif
3554
3555static int clk_duty_cycle_show(struct seq_file *s, void *data)
3556{
3557 struct clk_core *core = s->private;
3558 struct clk_duty *duty = &core->duty;
3559
3560 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3561
3562 return 0;
3563}
3564DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3565
3566static int clk_min_rate_show(struct seq_file *s, void *data)
3567{
3568 struct clk_core *core = s->private;
3569 unsigned long min_rate, max_rate;
3570
3571 clk_prepare_lock();
3572 clk_core_get_boundaries(core, &min_rate, &max_rate);
3573 clk_prepare_unlock();
3574 seq_printf(s, "%lu\n", min_rate);
3575
3576 return 0;
3577}
3578DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3579
3580static int clk_max_rate_show(struct seq_file *s, void *data)
3581{
3582 struct clk_core *core = s->private;
3583 unsigned long min_rate, max_rate;
3584
3585 clk_prepare_lock();
3586 clk_core_get_boundaries(core, &min_rate, &max_rate);
3587 clk_prepare_unlock();
3588 seq_printf(s, "%lu\n", max_rate);
3589
3590 return 0;
3591}
3592DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3593
3594static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3595{
3596 struct dentry *root;
3597
3598 if (!core || !pdentry)
3599 return;
3600
3601 root = debugfs_create_dir(core->name, pdentry);
3602 core->dentry = root;
3603
3604 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3605 &clk_rate_fops);
3606 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3607 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3608 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3609 debugfs_create_file("clk_phase", clk_phase_mode, root, core,
3610 &clk_phase_fops);
3611 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3612 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3613 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3614 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3615 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3616 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3617 &clk_duty_cycle_fops);
3618#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3619 debugfs_create_file("clk_prepare_enable", 0644, root, core,
3620 &clk_prepare_enable_fops);
3621
3622 if (core->num_parents > 1)
3623 debugfs_create_file("clk_parent", 0644, root, core,
3624 ¤t_parent_rw_fops);
3625 else
3626#endif
3627 if (core->num_parents > 0)
3628 debugfs_create_file("clk_parent", 0444, root, core,
3629 ¤t_parent_fops);
3630
3631 if (core->num_parents > 1)
3632 debugfs_create_file("clk_possible_parents", 0444, root, core,
3633 &possible_parents_fops);
3634
3635 if (core->ops->debug_init)
3636 core->ops->debug_init(core->hw, core->dentry);
3637}
3638
3639/**
3640 * clk_debug_register - add a clk node to the debugfs clk directory
3641 * @core: the clk being added to the debugfs clk directory
3642 *
3643 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3644 * initialized. Otherwise it bails out early since the debugfs clk directory
3645 * will be created lazily by clk_debug_init as part of a late_initcall.
3646 */
3647static void clk_debug_register(struct clk_core *core)
3648{
3649 mutex_lock(&clk_debug_lock);
3650 hlist_add_head(&core->debug_node, &clk_debug_list);
3651 if (inited)
3652 clk_debug_create_one(core, rootdir);
3653 mutex_unlock(&clk_debug_lock);
3654}
3655
3656 /**
3657 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3658 * @core: the clk being removed from the debugfs clk directory
3659 *
3660 * Dynamically removes a clk and all its child nodes from the
3661 * debugfs clk directory if clk->dentry points to debugfs created by
3662 * clk_debug_register in __clk_core_init.
3663 */
3664static void clk_debug_unregister(struct clk_core *core)
3665{
3666 mutex_lock(&clk_debug_lock);
3667 hlist_del_init(&core->debug_node);
3668 debugfs_remove_recursive(core->dentry);
3669 core->dentry = NULL;
3670 mutex_unlock(&clk_debug_lock);
3671}
3672
3673/**
3674 * clk_debug_init - lazily populate the debugfs clk directory
3675 *
3676 * clks are often initialized very early during boot before memory can be
3677 * dynamically allocated and well before debugfs is setup. This function
3678 * populates the debugfs clk directory once at boot-time when we know that
3679 * debugfs is setup. It should only be called once at boot-time, all other clks
3680 * added dynamically will be done so with clk_debug_register.
3681 */
3682static int __init clk_debug_init(void)
3683{
3684 struct clk_core *core;
3685
3686#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3687 pr_warn("\n");
3688 pr_warn("********************************************************************\n");
3689 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3690 pr_warn("** **\n");
3691 pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
3692 pr_warn("** **\n");
3693 pr_warn("** This means that this kernel is built to expose clk operations **\n");
3694 pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n");
3695 pr_warn("** to userspace, which may compromise security on your system. **\n");
3696 pr_warn("** **\n");
3697 pr_warn("** If you see this message and you are not debugging the **\n");
3698 pr_warn("** kernel, report this immediately to your vendor! **\n");
3699 pr_warn("** **\n");
3700 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3701 pr_warn("********************************************************************\n");
3702#endif
3703
3704 rootdir = debugfs_create_dir("clk", NULL);
3705
3706 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3707 &clk_summary_fops);
3708 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3709 &clk_dump_fops);
3710 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3711 &clk_summary_fops);
3712 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3713 &clk_dump_fops);
3714
3715 mutex_lock(&clk_debug_lock);
3716 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3717 clk_debug_create_one(core, rootdir);
3718
3719 inited = 1;
3720 mutex_unlock(&clk_debug_lock);
3721
3722 return 0;
3723}
3724late_initcall(clk_debug_init);
3725#else
3726static inline void clk_debug_register(struct clk_core *core) { }
3727static inline void clk_debug_unregister(struct clk_core *core)
3728{
3729}
3730#endif
3731
3732static void clk_core_reparent_orphans_nolock(void)
3733{
3734 struct clk_core *orphan;
3735 struct hlist_node *tmp2;
3736
3737 /*
3738 * walk the list of orphan clocks and reparent any that newly finds a
3739 * parent.
3740 */
3741 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3742 struct clk_core *parent = __clk_init_parent(orphan);
3743
3744 /*
3745 * We need to use __clk_set_parent_before() and _after() to
3746 * properly migrate any prepare/enable count of the orphan
3747 * clock. This is important for CLK_IS_CRITICAL clocks, which
3748 * are enabled during init but might not have a parent yet.
3749 */
3750 if (parent) {
3751 /* update the clk tree topology */
3752 __clk_set_parent_before(orphan, parent);
3753 __clk_set_parent_after(orphan, parent, NULL);
3754 __clk_recalc_accuracies(orphan);
3755 __clk_recalc_rates(orphan, true, 0);
3756
3757 /*
3758 * __clk_init_parent() will set the initial req_rate to
3759 * 0 if the clock doesn't have clk_ops::recalc_rate and
3760 * is an orphan when it's registered.
3761 *
3762 * 'req_rate' is used by clk_set_rate_range() and
3763 * clk_put() to trigger a clk_set_rate() call whenever
3764 * the boundaries are modified. Let's make sure
3765 * 'req_rate' is set to something non-zero so that
3766 * clk_set_rate_range() doesn't drop the frequency.
3767 */
3768 orphan->req_rate = orphan->rate;
3769 }
3770 }
3771}
3772
3773/**
3774 * __clk_core_init - initialize the data structures in a struct clk_core
3775 * @core: clk_core being initialized
3776 *
3777 * Initializes the lists in struct clk_core, queries the hardware for the
3778 * parent and rate and sets them both.
3779 */
3780static int __clk_core_init(struct clk_core *core)
3781{
3782 int ret;
3783 struct clk_core *parent;
3784 unsigned long rate;
3785 int phase;
3786
3787 clk_prepare_lock();
3788
3789 /*
3790 * Set hw->core after grabbing the prepare_lock to synchronize with
3791 * callers of clk_core_fill_parent_index() where we treat hw->core
3792 * being NULL as the clk not being registered yet. This is crucial so
3793 * that clks aren't parented until their parent is fully registered.
3794 */
3795 core->hw->core = core;
3796
3797 ret = clk_pm_runtime_get(core);
3798 if (ret)
3799 goto unlock;
3800
3801 /* check to see if a clock with this name is already registered */
3802 if (clk_core_lookup(core->name)) {
3803 pr_debug("%s: clk %s already initialized\n",
3804 __func__, core->name);
3805 ret = -EEXIST;
3806 goto out;
3807 }
3808
3809 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3810 if (core->ops->set_rate &&
3811 !((core->ops->round_rate || core->ops->determine_rate) &&
3812 core->ops->recalc_rate)) {
3813 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3814 __func__, core->name);
3815 ret = -EINVAL;
3816 goto out;
3817 }
3818
3819 if (core->ops->set_parent && !core->ops->get_parent) {
3820 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3821 __func__, core->name);
3822 ret = -EINVAL;
3823 goto out;
3824 }
3825
3826 if (core->ops->set_parent && !core->ops->determine_rate) {
3827 pr_err("%s: %s must implement .set_parent & .determine_rate\n",
3828 __func__, core->name);
3829 ret = -EINVAL;
3830 goto out;
3831 }
3832
3833 if (core->num_parents > 1 && !core->ops->get_parent) {
3834 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3835 __func__, core->name);
3836 ret = -EINVAL;
3837 goto out;
3838 }
3839
3840 if (core->ops->set_rate_and_parent &&
3841 !(core->ops->set_parent && core->ops->set_rate)) {
3842 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3843 __func__, core->name);
3844 ret = -EINVAL;
3845 goto out;
3846 }
3847
3848 /*
3849 * optional platform-specific magic
3850 *
3851 * The .init callback is not used by any of the basic clock types, but
3852 * exists for weird hardware that must perform initialization magic for
3853 * CCF to get an accurate view of clock for any other callbacks. It may
3854 * also be used needs to perform dynamic allocations. Such allocation
3855 * must be freed in the terminate() callback.
3856 * This callback shall not be used to initialize the parameters state,
3857 * such as rate, parent, etc ...
3858 *
3859 * If it exist, this callback should called before any other callback of
3860 * the clock
3861 */
3862 if (core->ops->init) {
3863 ret = core->ops->init(core->hw);
3864 if (ret)
3865 goto out;
3866 }
3867
3868 parent = core->parent = __clk_init_parent(core);
3869
3870 /*
3871 * Populate core->parent if parent has already been clk_core_init'd. If
3872 * parent has not yet been clk_core_init'd then place clk in the orphan
3873 * list. If clk doesn't have any parents then place it in the root
3874 * clk list.
3875 *
3876 * Every time a new clk is clk_init'd then we walk the list of orphan
3877 * clocks and re-parent any that are children of the clock currently
3878 * being clk_init'd.
3879 */
3880 if (parent) {
3881 hlist_add_head(&core->child_node, &parent->children);
3882 core->orphan = parent->orphan;
3883 } else if (!core->num_parents) {
3884 hlist_add_head(&core->child_node, &clk_root_list);
3885 core->orphan = false;
3886 } else {
3887 hlist_add_head(&core->child_node, &clk_orphan_list);
3888 core->orphan = true;
3889 }
3890
3891 /*
3892 * Set clk's accuracy. The preferred method is to use
3893 * .recalc_accuracy. For simple clocks and lazy developers the default
3894 * fallback is to use the parent's accuracy. If a clock doesn't have a
3895 * parent (or is orphaned) then accuracy is set to zero (perfect
3896 * clock).
3897 */
3898 if (core->ops->recalc_accuracy)
3899 core->accuracy = core->ops->recalc_accuracy(core->hw,
3900 clk_core_get_accuracy_no_lock(parent));
3901 else if (parent)
3902 core->accuracy = parent->accuracy;
3903 else
3904 core->accuracy = 0;
3905
3906 /*
3907 * Set clk's phase by clk_core_get_phase() caching the phase.
3908 * Since a phase is by definition relative to its parent, just
3909 * query the current clock phase, or just assume it's in phase.
3910 */
3911 phase = clk_core_get_phase(core);
3912 if (phase < 0) {
3913 ret = phase;
3914 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
3915 core->name);
3916 goto out;
3917 }
3918
3919 /*
3920 * Set clk's duty cycle.
3921 */
3922 clk_core_update_duty_cycle_nolock(core);
3923
3924 /*
3925 * Set clk's rate. The preferred method is to use .recalc_rate. For
3926 * simple clocks and lazy developers the default fallback is to use the
3927 * parent's rate. If a clock doesn't have a parent (or is orphaned)
3928 * then rate is set to zero.
3929 */
3930 if (core->ops->recalc_rate)
3931 rate = core->ops->recalc_rate(core->hw,
3932 clk_core_get_rate_nolock(parent));
3933 else if (parent)
3934 rate = parent->rate;
3935 else
3936 rate = 0;
3937 core->rate = core->req_rate = rate;
3938
3939 /*
3940 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
3941 * don't get accidentally disabled when walking the orphan tree and
3942 * reparenting clocks
3943 */
3944 if (core->flags & CLK_IS_CRITICAL) {
3945 ret = clk_core_prepare(core);
3946 if (ret) {
3947 pr_warn("%s: critical clk '%s' failed to prepare\n",
3948 __func__, core->name);
3949 goto out;
3950 }
3951
3952 ret = clk_core_enable_lock(core);
3953 if (ret) {
3954 pr_warn("%s: critical clk '%s' failed to enable\n",
3955 __func__, core->name);
3956 clk_core_unprepare(core);
3957 goto out;
3958 }
3959 }
3960
3961 clk_core_reparent_orphans_nolock();
3962
3963 kref_init(&core->ref);
3964out:
3965 clk_pm_runtime_put(core);
3966unlock:
3967 if (ret) {
3968 hlist_del_init(&core->child_node);
3969 core->hw->core = NULL;
3970 }
3971
3972 clk_prepare_unlock();
3973
3974 if (!ret)
3975 clk_debug_register(core);
3976
3977 return ret;
3978}
3979
3980/**
3981 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
3982 * @core: clk to add consumer to
3983 * @clk: consumer to link to a clk
3984 */
3985static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
3986{
3987 clk_prepare_lock();
3988 hlist_add_head(&clk->clks_node, &core->clks);
3989 clk_prepare_unlock();
3990}
3991
3992/**
3993 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
3994 * @clk: consumer to unlink
3995 */
3996static void clk_core_unlink_consumer(struct clk *clk)
3997{
3998 lockdep_assert_held(&prepare_lock);
3999 hlist_del(&clk->clks_node);
4000}
4001
4002/**
4003 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
4004 * @core: clk to allocate a consumer for
4005 * @dev_id: string describing device name
4006 * @con_id: connection ID string on device
4007 *
4008 * Returns: clk consumer left unlinked from the consumer list
4009 */
4010static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
4011 const char *con_id)
4012{
4013 struct clk *clk;
4014
4015 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
4016 if (!clk)
4017 return ERR_PTR(-ENOMEM);
4018
4019 clk->core = core;
4020 clk->dev_id = dev_id;
4021 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
4022 clk->max_rate = ULONG_MAX;
4023
4024 return clk;
4025}
4026
4027/**
4028 * free_clk - Free a clk consumer
4029 * @clk: clk consumer to free
4030 *
4031 * Note, this assumes the clk has been unlinked from the clk_core consumer
4032 * list.
4033 */
4034static void free_clk(struct clk *clk)
4035{
4036 kfree_const(clk->con_id);
4037 kfree(clk);
4038}
4039
4040/**
4041 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
4042 * a clk_hw
4043 * @dev: clk consumer device
4044 * @hw: clk_hw associated with the clk being consumed
4045 * @dev_id: string describing device name
4046 * @con_id: connection ID string on device
4047 *
4048 * This is the main function used to create a clk pointer for use by clk
4049 * consumers. It connects a consumer to the clk_core and clk_hw structures
4050 * used by the framework and clk provider respectively.
4051 */
4052struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
4053 const char *dev_id, const char *con_id)
4054{
4055 struct clk *clk;
4056 struct clk_core *core;
4057
4058 /* This is to allow this function to be chained to others */
4059 if (IS_ERR_OR_NULL(hw))
4060 return ERR_CAST(hw);
4061
4062 core = hw->core;
4063 clk = alloc_clk(core, dev_id, con_id);
4064 if (IS_ERR(clk))
4065 return clk;
4066 clk->dev = dev;
4067
4068 if (!try_module_get(core->owner)) {
4069 free_clk(clk);
4070 return ERR_PTR(-ENOENT);
4071 }
4072
4073 kref_get(&core->ref);
4074 clk_core_link_consumer(core, clk);
4075
4076 return clk;
4077}
4078
4079/**
4080 * clk_hw_get_clk - get clk consumer given an clk_hw
4081 * @hw: clk_hw associated with the clk being consumed
4082 * @con_id: connection ID string on device
4083 *
4084 * Returns: new clk consumer
4085 * This is the function to be used by providers which need
4086 * to get a consumer clk and act on the clock element
4087 * Calls to this function must be balanced with calls clk_put()
4088 */
4089struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
4090{
4091 struct device *dev = hw->core->dev;
4092 const char *name = dev ? dev_name(dev) : NULL;
4093
4094 return clk_hw_create_clk(dev, hw, name, con_id);
4095}
4096EXPORT_SYMBOL(clk_hw_get_clk);
4097
4098static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
4099{
4100 const char *dst;
4101
4102 if (!src) {
4103 if (must_exist)
4104 return -EINVAL;
4105 return 0;
4106 }
4107
4108 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
4109 if (!dst)
4110 return -ENOMEM;
4111
4112 return 0;
4113}
4114
4115static int clk_core_populate_parent_map(struct clk_core *core,
4116 const struct clk_init_data *init)
4117{
4118 u8 num_parents = init->num_parents;
4119 const char * const *parent_names = init->parent_names;
4120 const struct clk_hw **parent_hws = init->parent_hws;
4121 const struct clk_parent_data *parent_data = init->parent_data;
4122 int i, ret = 0;
4123 struct clk_parent_map *parents, *parent;
4124
4125 if (!num_parents)
4126 return 0;
4127
4128 /*
4129 * Avoid unnecessary string look-ups of clk_core's possible parents by
4130 * having a cache of names/clk_hw pointers to clk_core pointers.
4131 */
4132 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
4133 core->parents = parents;
4134 if (!parents)
4135 return -ENOMEM;
4136
4137 /* Copy everything over because it might be __initdata */
4138 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
4139 parent->index = -1;
4140 if (parent_names) {
4141 /* throw a WARN if any entries are NULL */
4142 WARN(!parent_names[i],
4143 "%s: invalid NULL in %s's .parent_names\n",
4144 __func__, core->name);
4145 ret = clk_cpy_name(&parent->name, parent_names[i],
4146 true);
4147 } else if (parent_data) {
4148 parent->hw = parent_data[i].hw;
4149 parent->index = parent_data[i].index;
4150 ret = clk_cpy_name(&parent->fw_name,
4151 parent_data[i].fw_name, false);
4152 if (!ret)
4153 ret = clk_cpy_name(&parent->name,
4154 parent_data[i].name,
4155 false);
4156 } else if (parent_hws) {
4157 parent->hw = parent_hws[i];
4158 } else {
4159 ret = -EINVAL;
4160 WARN(1, "Must specify parents if num_parents > 0\n");
4161 }
4162
4163 if (ret) {
4164 do {
4165 kfree_const(parents[i].name);
4166 kfree_const(parents[i].fw_name);
4167 } while (--i >= 0);
4168 kfree(parents);
4169
4170 return ret;
4171 }
4172 }
4173
4174 return 0;
4175}
4176
4177static void clk_core_free_parent_map(struct clk_core *core)
4178{
4179 int i = core->num_parents;
4180
4181 if (!core->num_parents)
4182 return;
4183
4184 while (--i >= 0) {
4185 kfree_const(core->parents[i].name);
4186 kfree_const(core->parents[i].fw_name);
4187 }
4188
4189 kfree(core->parents);
4190}
4191
4192static struct clk *
4193__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
4194{
4195 int ret;
4196 struct clk_core *core;
4197 const struct clk_init_data *init = hw->init;
4198
4199 /*
4200 * The init data is not supposed to be used outside of registration path.
4201 * Set it to NULL so that provider drivers can't use it either and so that
4202 * we catch use of hw->init early on in the core.
4203 */
4204 hw->init = NULL;
4205
4206 core = kzalloc(sizeof(*core), GFP_KERNEL);
4207 if (!core) {
4208 ret = -ENOMEM;
4209 goto fail_out;
4210 }
4211
4212 core->name = kstrdup_const(init->name, GFP_KERNEL);
4213 if (!core->name) {
4214 ret = -ENOMEM;
4215 goto fail_name;
4216 }
4217
4218 if (WARN_ON(!init->ops)) {
4219 ret = -EINVAL;
4220 goto fail_ops;
4221 }
4222 core->ops = init->ops;
4223
4224 if (dev && pm_runtime_enabled(dev))
4225 core->rpm_enabled = true;
4226 core->dev = dev;
4227 core->of_node = np;
4228 if (dev && dev->driver)
4229 core->owner = dev->driver->owner;
4230 core->hw = hw;
4231 core->flags = init->flags;
4232 core->num_parents = init->num_parents;
4233 core->min_rate = 0;
4234 core->max_rate = ULONG_MAX;
4235
4236 ret = clk_core_populate_parent_map(core, init);
4237 if (ret)
4238 goto fail_parents;
4239
4240 INIT_HLIST_HEAD(&core->clks);
4241
4242 /*
4243 * Don't call clk_hw_create_clk() here because that would pin the
4244 * provider module to itself and prevent it from ever being removed.
4245 */
4246 hw->clk = alloc_clk(core, NULL, NULL);
4247 if (IS_ERR(hw->clk)) {
4248 ret = PTR_ERR(hw->clk);
4249 goto fail_create_clk;
4250 }
4251
4252 clk_core_link_consumer(core, hw->clk);
4253
4254 ret = __clk_core_init(core);
4255 if (!ret)
4256 return hw->clk;
4257
4258 clk_prepare_lock();
4259 clk_core_unlink_consumer(hw->clk);
4260 clk_prepare_unlock();
4261
4262 free_clk(hw->clk);
4263 hw->clk = NULL;
4264
4265fail_create_clk:
4266 clk_core_free_parent_map(core);
4267fail_parents:
4268fail_ops:
4269 kfree_const(core->name);
4270fail_name:
4271 kfree(core);
4272fail_out:
4273 return ERR_PTR(ret);
4274}
4275
4276/**
4277 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
4278 * @dev: Device to get device node of
4279 *
4280 * Return: device node pointer of @dev, or the device node pointer of
4281 * @dev->parent if dev doesn't have a device node, or NULL if neither
4282 * @dev or @dev->parent have a device node.
4283 */
4284static struct device_node *dev_or_parent_of_node(struct device *dev)
4285{
4286 struct device_node *np;
4287
4288 if (!dev)
4289 return NULL;
4290
4291 np = dev_of_node(dev);
4292 if (!np)
4293 np = dev_of_node(dev->parent);
4294
4295 return np;
4296}
4297
4298/**
4299 * clk_register - allocate a new clock, register it and return an opaque cookie
4300 * @dev: device that is registering this clock
4301 * @hw: link to hardware-specific clock data
4302 *
4303 * clk_register is the *deprecated* interface for populating the clock tree with
4304 * new clock nodes. Use clk_hw_register() instead.
4305 *
4306 * Returns: a pointer to the newly allocated struct clk which
4307 * cannot be dereferenced by driver code but may be used in conjunction with the
4308 * rest of the clock API. In the event of an error clk_register will return an
4309 * error code; drivers must test for an error code after calling clk_register.
4310 */
4311struct clk *clk_register(struct device *dev, struct clk_hw *hw)
4312{
4313 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
4314}
4315EXPORT_SYMBOL_GPL(clk_register);
4316
4317/**
4318 * clk_hw_register - register a clk_hw and return an error code
4319 * @dev: device that is registering this clock
4320 * @hw: link to hardware-specific clock data
4321 *
4322 * clk_hw_register is the primary interface for populating the clock tree with
4323 * new clock nodes. It returns an integer equal to zero indicating success or
4324 * less than zero indicating failure. Drivers must test for an error code after
4325 * calling clk_hw_register().
4326 */
4327int clk_hw_register(struct device *dev, struct clk_hw *hw)
4328{
4329 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
4330 hw));
4331}
4332EXPORT_SYMBOL_GPL(clk_hw_register);
4333
4334/*
4335 * of_clk_hw_register - register a clk_hw and return an error code
4336 * @node: device_node of device that is registering this clock
4337 * @hw: link to hardware-specific clock data
4338 *
4339 * of_clk_hw_register() is the primary interface for populating the clock tree
4340 * with new clock nodes when a struct device is not available, but a struct
4341 * device_node is. It returns an integer equal to zero indicating success or
4342 * less than zero indicating failure. Drivers must test for an error code after
4343 * calling of_clk_hw_register().
4344 */
4345int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
4346{
4347 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
4348}
4349EXPORT_SYMBOL_GPL(of_clk_hw_register);
4350
4351/* Free memory allocated for a clock. */
4352static void __clk_release(struct kref *ref)
4353{
4354 struct clk_core *core = container_of(ref, struct clk_core, ref);
4355
4356 lockdep_assert_held(&prepare_lock);
4357
4358 clk_core_free_parent_map(core);
4359 kfree_const(core->name);
4360 kfree(core);
4361}
4362
4363/*
4364 * Empty clk_ops for unregistered clocks. These are used temporarily
4365 * after clk_unregister() was called on a clock and until last clock
4366 * consumer calls clk_put() and the struct clk object is freed.
4367 */
4368static int clk_nodrv_prepare_enable(struct clk_hw *hw)
4369{
4370 return -ENXIO;
4371}
4372
4373static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
4374{
4375 WARN_ON_ONCE(1);
4376}
4377
4378static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
4379 unsigned long parent_rate)
4380{
4381 return -ENXIO;
4382}
4383
4384static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
4385{
4386 return -ENXIO;
4387}
4388
4389static int clk_nodrv_determine_rate(struct clk_hw *hw,
4390 struct clk_rate_request *req)
4391{
4392 return -ENXIO;
4393}
4394
4395static const struct clk_ops clk_nodrv_ops = {
4396 .enable = clk_nodrv_prepare_enable,
4397 .disable = clk_nodrv_disable_unprepare,
4398 .prepare = clk_nodrv_prepare_enable,
4399 .unprepare = clk_nodrv_disable_unprepare,
4400 .determine_rate = clk_nodrv_determine_rate,
4401 .set_rate = clk_nodrv_set_rate,
4402 .set_parent = clk_nodrv_set_parent,
4403};
4404
4405static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4406 const struct clk_core *target)
4407{
4408 int i;
4409 struct clk_core *child;
4410
4411 for (i = 0; i < root->num_parents; i++)
4412 if (root->parents[i].core == target)
4413 root->parents[i].core = NULL;
4414
4415 hlist_for_each_entry(child, &root->children, child_node)
4416 clk_core_evict_parent_cache_subtree(child, target);
4417}
4418
4419/* Remove this clk from all parent caches */
4420static void clk_core_evict_parent_cache(struct clk_core *core)
4421{
4422 const struct hlist_head **lists;
4423 struct clk_core *root;
4424
4425 lockdep_assert_held(&prepare_lock);
4426
4427 for (lists = all_lists; *lists; lists++)
4428 hlist_for_each_entry(root, *lists, child_node)
4429 clk_core_evict_parent_cache_subtree(root, core);
4430
4431}
4432
4433/**
4434 * clk_unregister - unregister a currently registered clock
4435 * @clk: clock to unregister
4436 */
4437void clk_unregister(struct clk *clk)
4438{
4439 unsigned long flags;
4440 const struct clk_ops *ops;
4441
4442 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4443 return;
4444
4445 clk_debug_unregister(clk->core);
4446
4447 clk_prepare_lock();
4448
4449 ops = clk->core->ops;
4450 if (ops == &clk_nodrv_ops) {
4451 pr_err("%s: unregistered clock: %s\n", __func__,
4452 clk->core->name);
4453 goto unlock;
4454 }
4455 /*
4456 * Assign empty clock ops for consumers that might still hold
4457 * a reference to this clock.
4458 */
4459 flags = clk_enable_lock();
4460 clk->core->ops = &clk_nodrv_ops;
4461 clk_enable_unlock(flags);
4462
4463 if (ops->terminate)
4464 ops->terminate(clk->core->hw);
4465
4466 if (!hlist_empty(&clk->core->children)) {
4467 struct clk_core *child;
4468 struct hlist_node *t;
4469
4470 /* Reparent all children to the orphan list. */
4471 hlist_for_each_entry_safe(child, t, &clk->core->children,
4472 child_node)
4473 clk_core_set_parent_nolock(child, NULL);
4474 }
4475
4476 clk_core_evict_parent_cache(clk->core);
4477
4478 hlist_del_init(&clk->core->child_node);
4479
4480 if (clk->core->prepare_count)
4481 pr_warn("%s: unregistering prepared clock: %s\n",
4482 __func__, clk->core->name);
4483
4484 if (clk->core->protect_count)
4485 pr_warn("%s: unregistering protected clock: %s\n",
4486 __func__, clk->core->name);
4487
4488 kref_put(&clk->core->ref, __clk_release);
4489 free_clk(clk);
4490unlock:
4491 clk_prepare_unlock();
4492}
4493EXPORT_SYMBOL_GPL(clk_unregister);
4494
4495/**
4496 * clk_hw_unregister - unregister a currently registered clk_hw
4497 * @hw: hardware-specific clock data to unregister
4498 */
4499void clk_hw_unregister(struct clk_hw *hw)
4500{
4501 clk_unregister(hw->clk);
4502}
4503EXPORT_SYMBOL_GPL(clk_hw_unregister);
4504
4505static void devm_clk_unregister_cb(struct device *dev, void *res)
4506{
4507 clk_unregister(*(struct clk **)res);
4508}
4509
4510static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4511{
4512 clk_hw_unregister(*(struct clk_hw **)res);
4513}
4514
4515/**
4516 * devm_clk_register - resource managed clk_register()
4517 * @dev: device that is registering this clock
4518 * @hw: link to hardware-specific clock data
4519 *
4520 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4521 *
4522 * Clocks returned from this function are automatically clk_unregister()ed on
4523 * driver detach. See clk_register() for more information.
4524 */
4525struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4526{
4527 struct clk *clk;
4528 struct clk **clkp;
4529
4530 clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4531 if (!clkp)
4532 return ERR_PTR(-ENOMEM);
4533
4534 clk = clk_register(dev, hw);
4535 if (!IS_ERR(clk)) {
4536 *clkp = clk;
4537 devres_add(dev, clkp);
4538 } else {
4539 devres_free(clkp);
4540 }
4541
4542 return clk;
4543}
4544EXPORT_SYMBOL_GPL(devm_clk_register);
4545
4546/**
4547 * devm_clk_hw_register - resource managed clk_hw_register()
4548 * @dev: device that is registering this clock
4549 * @hw: link to hardware-specific clock data
4550 *
4551 * Managed clk_hw_register(). Clocks registered by this function are
4552 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4553 * for more information.
4554 */
4555int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4556{
4557 struct clk_hw **hwp;
4558 int ret;
4559
4560 hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4561 if (!hwp)
4562 return -ENOMEM;
4563
4564 ret = clk_hw_register(dev, hw);
4565 if (!ret) {
4566 *hwp = hw;
4567 devres_add(dev, hwp);
4568 } else {
4569 devres_free(hwp);
4570 }
4571
4572 return ret;
4573}
4574EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4575
4576static void devm_clk_release(struct device *dev, void *res)
4577{
4578 clk_put(*(struct clk **)res);
4579}
4580
4581/**
4582 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4583 * @dev: device that is registering this clock
4584 * @hw: clk_hw associated with the clk being consumed
4585 * @con_id: connection ID string on device
4586 *
4587 * Managed clk_hw_get_clk(). Clocks got with this function are
4588 * automatically clk_put() on driver detach. See clk_put()
4589 * for more information.
4590 */
4591struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4592 const char *con_id)
4593{
4594 struct clk *clk;
4595 struct clk **clkp;
4596
4597 /* This should not happen because it would mean we have drivers
4598 * passing around clk_hw pointers instead of having the caller use
4599 * proper clk_get() style APIs
4600 */
4601 WARN_ON_ONCE(dev != hw->core->dev);
4602
4603 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4604 if (!clkp)
4605 return ERR_PTR(-ENOMEM);
4606
4607 clk = clk_hw_get_clk(hw, con_id);
4608 if (!IS_ERR(clk)) {
4609 *clkp = clk;
4610 devres_add(dev, clkp);
4611 } else {
4612 devres_free(clkp);
4613 }
4614
4615 return clk;
4616}
4617EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4618
4619/*
4620 * clkdev helpers
4621 */
4622
4623void __clk_put(struct clk *clk)
4624{
4625 struct module *owner;
4626
4627 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4628 return;
4629
4630 clk_prepare_lock();
4631
4632 /*
4633 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4634 * given user should be balanced with calls to clk_rate_exclusive_put()
4635 * and by that same consumer
4636 */
4637 if (WARN_ON(clk->exclusive_count)) {
4638 /* We voiced our concern, let's sanitize the situation */
4639 clk->core->protect_count -= (clk->exclusive_count - 1);
4640 clk_core_rate_unprotect(clk->core);
4641 clk->exclusive_count = 0;
4642 }
4643
4644 hlist_del(&clk->clks_node);
4645
4646 /* If we had any boundaries on that clock, let's drop them. */
4647 if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
4648 clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
4649
4650 owner = clk->core->owner;
4651 kref_put(&clk->core->ref, __clk_release);
4652
4653 clk_prepare_unlock();
4654
4655 module_put(owner);
4656
4657 free_clk(clk);
4658}
4659
4660/*** clk rate change notifiers ***/
4661
4662/**
4663 * clk_notifier_register - add a clk rate change notifier
4664 * @clk: struct clk * to watch
4665 * @nb: struct notifier_block * with callback info
4666 *
4667 * Request notification when clk's rate changes. This uses an SRCU
4668 * notifier because we want it to block and notifier unregistrations are
4669 * uncommon. The callbacks associated with the notifier must not
4670 * re-enter into the clk framework by calling any top-level clk APIs;
4671 * this will cause a nested prepare_lock mutex.
4672 *
4673 * In all notification cases (pre, post and abort rate change) the original
4674 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4675 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4676 *
4677 * clk_notifier_register() must be called from non-atomic context.
4678 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4679 * allocation failure; otherwise, passes along the return value of
4680 * srcu_notifier_chain_register().
4681 */
4682int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4683{
4684 struct clk_notifier *cn;
4685 int ret = -ENOMEM;
4686
4687 if (!clk || !nb)
4688 return -EINVAL;
4689
4690 clk_prepare_lock();
4691
4692 /* search the list of notifiers for this clk */
4693 list_for_each_entry(cn, &clk_notifier_list, node)
4694 if (cn->clk == clk)
4695 goto found;
4696
4697 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4698 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4699 if (!cn)
4700 goto out;
4701
4702 cn->clk = clk;
4703 srcu_init_notifier_head(&cn->notifier_head);
4704
4705 list_add(&cn->node, &clk_notifier_list);
4706
4707found:
4708 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4709
4710 clk->core->notifier_count++;
4711
4712out:
4713 clk_prepare_unlock();
4714
4715 return ret;
4716}
4717EXPORT_SYMBOL_GPL(clk_notifier_register);
4718
4719/**
4720 * clk_notifier_unregister - remove a clk rate change notifier
4721 * @clk: struct clk *
4722 * @nb: struct notifier_block * with callback info
4723 *
4724 * Request no further notification for changes to 'clk' and frees memory
4725 * allocated in clk_notifier_register.
4726 *
4727 * Returns -EINVAL if called with null arguments; otherwise, passes
4728 * along the return value of srcu_notifier_chain_unregister().
4729 */
4730int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4731{
4732 struct clk_notifier *cn;
4733 int ret = -ENOENT;
4734
4735 if (!clk || !nb)
4736 return -EINVAL;
4737
4738 clk_prepare_lock();
4739
4740 list_for_each_entry(cn, &clk_notifier_list, node) {
4741 if (cn->clk == clk) {
4742 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4743
4744 clk->core->notifier_count--;
4745
4746 /* XXX the notifier code should handle this better */
4747 if (!cn->notifier_head.head) {
4748 srcu_cleanup_notifier_head(&cn->notifier_head);
4749 list_del(&cn->node);
4750 kfree(cn);
4751 }
4752 break;
4753 }
4754 }
4755
4756 clk_prepare_unlock();
4757
4758 return ret;
4759}
4760EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4761
4762struct clk_notifier_devres {
4763 struct clk *clk;
4764 struct notifier_block *nb;
4765};
4766
4767static void devm_clk_notifier_release(struct device *dev, void *res)
4768{
4769 struct clk_notifier_devres *devres = res;
4770
4771 clk_notifier_unregister(devres->clk, devres->nb);
4772}
4773
4774int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4775 struct notifier_block *nb)
4776{
4777 struct clk_notifier_devres *devres;
4778 int ret;
4779
4780 devres = devres_alloc(devm_clk_notifier_release,
4781 sizeof(*devres), GFP_KERNEL);
4782
4783 if (!devres)
4784 return -ENOMEM;
4785
4786 ret = clk_notifier_register(clk, nb);
4787 if (!ret) {
4788 devres->clk = clk;
4789 devres->nb = nb;
4790 devres_add(dev, devres);
4791 } else {
4792 devres_free(devres);
4793 }
4794
4795 return ret;
4796}
4797EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4798
4799#ifdef CONFIG_OF
4800static void clk_core_reparent_orphans(void)
4801{
4802 clk_prepare_lock();
4803 clk_core_reparent_orphans_nolock();
4804 clk_prepare_unlock();
4805}
4806
4807/**
4808 * struct of_clk_provider - Clock provider registration structure
4809 * @link: Entry in global list of clock providers
4810 * @node: Pointer to device tree node of clock provider
4811 * @get: Get clock callback. Returns NULL or a struct clk for the
4812 * given clock specifier
4813 * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a
4814 * struct clk_hw for the given clock specifier
4815 * @data: context pointer to be passed into @get callback
4816 */
4817struct of_clk_provider {
4818 struct list_head link;
4819
4820 struct device_node *node;
4821 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4822 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4823 void *data;
4824};
4825
4826extern struct of_device_id __clk_of_table;
4827static const struct of_device_id __clk_of_table_sentinel
4828 __used __section("__clk_of_table_end");
4829
4830static LIST_HEAD(of_clk_providers);
4831static DEFINE_MUTEX(of_clk_mutex);
4832
4833struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4834 void *data)
4835{
4836 return data;
4837}
4838EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4839
4840struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4841{
4842 return data;
4843}
4844EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4845
4846struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4847{
4848 struct clk_onecell_data *clk_data = data;
4849 unsigned int idx = clkspec->args[0];
4850
4851 if (idx >= clk_data->clk_num) {
4852 pr_err("%s: invalid clock index %u\n", __func__, idx);
4853 return ERR_PTR(-EINVAL);
4854 }
4855
4856 return clk_data->clks[idx];
4857}
4858EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4859
4860struct clk_hw *
4861of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4862{
4863 struct clk_hw_onecell_data *hw_data = data;
4864 unsigned int idx = clkspec->args[0];
4865
4866 if (idx >= hw_data->num) {
4867 pr_err("%s: invalid index %u\n", __func__, idx);
4868 return ERR_PTR(-EINVAL);
4869 }
4870
4871 return hw_data->hws[idx];
4872}
4873EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4874
4875/**
4876 * of_clk_add_provider() - Register a clock provider for a node
4877 * @np: Device node pointer associated with clock provider
4878 * @clk_src_get: callback for decoding clock
4879 * @data: context pointer for @clk_src_get callback.
4880 *
4881 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4882 */
4883int of_clk_add_provider(struct device_node *np,
4884 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4885 void *data),
4886 void *data)
4887{
4888 struct of_clk_provider *cp;
4889 int ret;
4890
4891 if (!np)
4892 return 0;
4893
4894 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4895 if (!cp)
4896 return -ENOMEM;
4897
4898 cp->node = of_node_get(np);
4899 cp->data = data;
4900 cp->get = clk_src_get;
4901
4902 mutex_lock(&of_clk_mutex);
4903 list_add(&cp->link, &of_clk_providers);
4904 mutex_unlock(&of_clk_mutex);
4905 pr_debug("Added clock from %pOF\n", np);
4906
4907 clk_core_reparent_orphans();
4908
4909 ret = of_clk_set_defaults(np, true);
4910 if (ret < 0)
4911 of_clk_del_provider(np);
4912
4913 fwnode_dev_initialized(&np->fwnode, true);
4914
4915 return ret;
4916}
4917EXPORT_SYMBOL_GPL(of_clk_add_provider);
4918
4919/**
4920 * of_clk_add_hw_provider() - Register a clock provider for a node
4921 * @np: Device node pointer associated with clock provider
4922 * @get: callback for decoding clk_hw
4923 * @data: context pointer for @get callback.
4924 */
4925int of_clk_add_hw_provider(struct device_node *np,
4926 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
4927 void *data),
4928 void *data)
4929{
4930 struct of_clk_provider *cp;
4931 int ret;
4932
4933 if (!np)
4934 return 0;
4935
4936 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
4937 if (!cp)
4938 return -ENOMEM;
4939
4940 cp->node = of_node_get(np);
4941 cp->data = data;
4942 cp->get_hw = get;
4943
4944 mutex_lock(&of_clk_mutex);
4945 list_add(&cp->link, &of_clk_providers);
4946 mutex_unlock(&of_clk_mutex);
4947 pr_debug("Added clk_hw provider from %pOF\n", np);
4948
4949 clk_core_reparent_orphans();
4950
4951 ret = of_clk_set_defaults(np, true);
4952 if (ret < 0)
4953 of_clk_del_provider(np);
4954
4955 fwnode_dev_initialized(&np->fwnode, true);
4956
4957 return ret;
4958}
4959EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
4960
4961static void devm_of_clk_release_provider(struct device *dev, void *res)
4962{
4963 of_clk_del_provider(*(struct device_node **)res);
4964}
4965
4966/*
4967 * We allow a child device to use its parent device as the clock provider node
4968 * for cases like MFD sub-devices where the child device driver wants to use
4969 * devm_*() APIs but not list the device in DT as a sub-node.
4970 */
4971static struct device_node *get_clk_provider_node(struct device *dev)
4972{
4973 struct device_node *np, *parent_np;
4974
4975 np = dev->of_node;
4976 parent_np = dev->parent ? dev->parent->of_node : NULL;
4977
4978 if (!of_property_present(np, "#clock-cells"))
4979 if (of_property_present(parent_np, "#clock-cells"))
4980 np = parent_np;
4981
4982 return np;
4983}
4984
4985/**
4986 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
4987 * @dev: Device acting as the clock provider (used for DT node and lifetime)
4988 * @get: callback for decoding clk_hw
4989 * @data: context pointer for @get callback
4990 *
4991 * Registers clock provider for given device's node. If the device has no DT
4992 * node or if the device node lacks of clock provider information (#clock-cells)
4993 * then the parent device's node is scanned for this information. If parent node
4994 * has the #clock-cells then it is used in registration. Provider is
4995 * automatically released at device exit.
4996 *
4997 * Return: 0 on success or an errno on failure.
4998 */
4999int devm_of_clk_add_hw_provider(struct device *dev,
5000 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
5001 void *data),
5002 void *data)
5003{
5004 struct device_node **ptr, *np;
5005 int ret;
5006
5007 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
5008 GFP_KERNEL);
5009 if (!ptr)
5010 return -ENOMEM;
5011
5012 np = get_clk_provider_node(dev);
5013 ret = of_clk_add_hw_provider(np, get, data);
5014 if (!ret) {
5015 *ptr = np;
5016 devres_add(dev, ptr);
5017 } else {
5018 devres_free(ptr);
5019 }
5020
5021 return ret;
5022}
5023EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
5024
5025/**
5026 * of_clk_del_provider() - Remove a previously registered clock provider
5027 * @np: Device node pointer associated with clock provider
5028 */
5029void of_clk_del_provider(struct device_node *np)
5030{
5031 struct of_clk_provider *cp;
5032
5033 if (!np)
5034 return;
5035
5036 mutex_lock(&of_clk_mutex);
5037 list_for_each_entry(cp, &of_clk_providers, link) {
5038 if (cp->node == np) {
5039 list_del(&cp->link);
5040 fwnode_dev_initialized(&np->fwnode, false);
5041 of_node_put(cp->node);
5042 kfree(cp);
5043 break;
5044 }
5045 }
5046 mutex_unlock(&of_clk_mutex);
5047}
5048EXPORT_SYMBOL_GPL(of_clk_del_provider);
5049
5050/**
5051 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
5052 * @np: device node to parse clock specifier from
5053 * @index: index of phandle to parse clock out of. If index < 0, @name is used
5054 * @name: clock name to find and parse. If name is NULL, the index is used
5055 * @out_args: Result of parsing the clock specifier
5056 *
5057 * Parses a device node's "clocks" and "clock-names" properties to find the
5058 * phandle and cells for the index or name that is desired. The resulting clock
5059 * specifier is placed into @out_args, or an errno is returned when there's a
5060 * parsing error. The @index argument is ignored if @name is non-NULL.
5061 *
5062 * Example:
5063 *
5064 * phandle1: clock-controller@1 {
5065 * #clock-cells = <2>;
5066 * }
5067 *
5068 * phandle2: clock-controller@2 {
5069 * #clock-cells = <1>;
5070 * }
5071 *
5072 * clock-consumer@3 {
5073 * clocks = <&phandle1 1 2 &phandle2 3>;
5074 * clock-names = "name1", "name2";
5075 * }
5076 *
5077 * To get a device_node for `clock-controller@2' node you may call this
5078 * function a few different ways:
5079 *
5080 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
5081 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
5082 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
5083 *
5084 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
5085 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
5086 * the "clock-names" property of @np.
5087 */
5088static int of_parse_clkspec(const struct device_node *np, int index,
5089 const char *name, struct of_phandle_args *out_args)
5090{
5091 int ret = -ENOENT;
5092
5093 /* Walk up the tree of devices looking for a clock property that matches */
5094 while (np) {
5095 /*
5096 * For named clocks, first look up the name in the
5097 * "clock-names" property. If it cannot be found, then index
5098 * will be an error code and of_parse_phandle_with_args() will
5099 * return -EINVAL.
5100 */
5101 if (name)
5102 index = of_property_match_string(np, "clock-names", name);
5103 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
5104 index, out_args);
5105 if (!ret)
5106 break;
5107 if (name && index >= 0)
5108 break;
5109
5110 /*
5111 * No matching clock found on this node. If the parent node
5112 * has a "clock-ranges" property, then we can try one of its
5113 * clocks.
5114 */
5115 np = np->parent;
5116 if (np && !of_get_property(np, "clock-ranges", NULL))
5117 break;
5118 index = 0;
5119 }
5120
5121 return ret;
5122}
5123
5124static struct clk_hw *
5125__of_clk_get_hw_from_provider(struct of_clk_provider *provider,
5126 struct of_phandle_args *clkspec)
5127{
5128 struct clk *clk;
5129
5130 if (provider->get_hw)
5131 return provider->get_hw(clkspec, provider->data);
5132
5133 clk = provider->get(clkspec, provider->data);
5134 if (IS_ERR(clk))
5135 return ERR_CAST(clk);
5136 return __clk_get_hw(clk);
5137}
5138
5139static struct clk_hw *
5140of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
5141{
5142 struct of_clk_provider *provider;
5143 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
5144
5145 if (!clkspec)
5146 return ERR_PTR(-EINVAL);
5147
5148 mutex_lock(&of_clk_mutex);
5149 list_for_each_entry(provider, &of_clk_providers, link) {
5150 if (provider->node == clkspec->np) {
5151 hw = __of_clk_get_hw_from_provider(provider, clkspec);
5152 if (!IS_ERR(hw))
5153 break;
5154 }
5155 }
5156 mutex_unlock(&of_clk_mutex);
5157
5158 return hw;
5159}
5160
5161/**
5162 * of_clk_get_from_provider() - Lookup a clock from a clock provider
5163 * @clkspec: pointer to a clock specifier data structure
5164 *
5165 * This function looks up a struct clk from the registered list of clock
5166 * providers, an input is a clock specifier data structure as returned
5167 * from the of_parse_phandle_with_args() function call.
5168 */
5169struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
5170{
5171 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
5172
5173 return clk_hw_create_clk(NULL, hw, NULL, __func__);
5174}
5175EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
5176
5177struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
5178 const char *con_id)
5179{
5180 int ret;
5181 struct clk_hw *hw;
5182 struct of_phandle_args clkspec;
5183
5184 ret = of_parse_clkspec(np, index, con_id, &clkspec);
5185 if (ret)
5186 return ERR_PTR(ret);
5187
5188 hw = of_clk_get_hw_from_clkspec(&clkspec);
5189 of_node_put(clkspec.np);
5190
5191 return hw;
5192}
5193
5194static struct clk *__of_clk_get(struct device_node *np,
5195 int index, const char *dev_id,
5196 const char *con_id)
5197{
5198 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
5199
5200 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
5201}
5202
5203struct clk *of_clk_get(struct device_node *np, int index)
5204{
5205 return __of_clk_get(np, index, np->full_name, NULL);
5206}
5207EXPORT_SYMBOL(of_clk_get);
5208
5209/**
5210 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
5211 * @np: pointer to clock consumer node
5212 * @name: name of consumer's clock input, or NULL for the first clock reference
5213 *
5214 * This function parses the clocks and clock-names properties,
5215 * and uses them to look up the struct clk from the registered list of clock
5216 * providers.
5217 */
5218struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
5219{
5220 if (!np)
5221 return ERR_PTR(-ENOENT);
5222
5223 return __of_clk_get(np, 0, np->full_name, name);
5224}
5225EXPORT_SYMBOL(of_clk_get_by_name);
5226
5227/**
5228 * of_clk_get_parent_count() - Count the number of clocks a device node has
5229 * @np: device node to count
5230 *
5231 * Returns: The number of clocks that are possible parents of this node
5232 */
5233unsigned int of_clk_get_parent_count(const struct device_node *np)
5234{
5235 int count;
5236
5237 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
5238 if (count < 0)
5239 return 0;
5240
5241 return count;
5242}
5243EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
5244
5245const char *of_clk_get_parent_name(const struct device_node *np, int index)
5246{
5247 struct of_phandle_args clkspec;
5248 struct property *prop;
5249 const char *clk_name;
5250 const __be32 *vp;
5251 u32 pv;
5252 int rc;
5253 int count;
5254 struct clk *clk;
5255
5256 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
5257 &clkspec);
5258 if (rc)
5259 return NULL;
5260
5261 index = clkspec.args_count ? clkspec.args[0] : 0;
5262 count = 0;
5263
5264 /* if there is an indices property, use it to transfer the index
5265 * specified into an array offset for the clock-output-names property.
5266 */
5267 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
5268 if (index == pv) {
5269 index = count;
5270 break;
5271 }
5272 count++;
5273 }
5274 /* We went off the end of 'clock-indices' without finding it */
5275 if (prop && !vp)
5276 return NULL;
5277
5278 if (of_property_read_string_index(clkspec.np, "clock-output-names",
5279 index,
5280 &clk_name) < 0) {
5281 /*
5282 * Best effort to get the name if the clock has been
5283 * registered with the framework. If the clock isn't
5284 * registered, we return the node name as the name of
5285 * the clock as long as #clock-cells = 0.
5286 */
5287 clk = of_clk_get_from_provider(&clkspec);
5288 if (IS_ERR(clk)) {
5289 if (clkspec.args_count == 0)
5290 clk_name = clkspec.np->name;
5291 else
5292 clk_name = NULL;
5293 } else {
5294 clk_name = __clk_get_name(clk);
5295 clk_put(clk);
5296 }
5297 }
5298
5299
5300 of_node_put(clkspec.np);
5301 return clk_name;
5302}
5303EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
5304
5305/**
5306 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
5307 * number of parents
5308 * @np: Device node pointer associated with clock provider
5309 * @parents: pointer to char array that hold the parents' names
5310 * @size: size of the @parents array
5311 *
5312 * Return: number of parents for the clock node.
5313 */
5314int of_clk_parent_fill(struct device_node *np, const char **parents,
5315 unsigned int size)
5316{
5317 unsigned int i = 0;
5318
5319 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
5320 i++;
5321
5322 return i;
5323}
5324EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5325
5326struct clock_provider {
5327 void (*clk_init_cb)(struct device_node *);
5328 struct device_node *np;
5329 struct list_head node;
5330};
5331
5332/*
5333 * This function looks for a parent clock. If there is one, then it
5334 * checks that the provider for this parent clock was initialized, in
5335 * this case the parent clock will be ready.
5336 */
5337static int parent_ready(struct device_node *np)
5338{
5339 int i = 0;
5340
5341 while (true) {
5342 struct clk *clk = of_clk_get(np, i);
5343
5344 /* this parent is ready we can check the next one */
5345 if (!IS_ERR(clk)) {
5346 clk_put(clk);
5347 i++;
5348 continue;
5349 }
5350
5351 /* at least one parent is not ready, we exit now */
5352 if (PTR_ERR(clk) == -EPROBE_DEFER)
5353 return 0;
5354
5355 /*
5356 * Here we make assumption that the device tree is
5357 * written correctly. So an error means that there is
5358 * no more parent. As we didn't exit yet, then the
5359 * previous parent are ready. If there is no clock
5360 * parent, no need to wait for them, then we can
5361 * consider their absence as being ready
5362 */
5363 return 1;
5364 }
5365}
5366
5367/**
5368 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5369 * @np: Device node pointer associated with clock provider
5370 * @index: clock index
5371 * @flags: pointer to top-level framework flags
5372 *
5373 * Detects if the clock-critical property exists and, if so, sets the
5374 * corresponding CLK_IS_CRITICAL flag.
5375 *
5376 * Do not use this function. It exists only for legacy Device Tree
5377 * bindings, such as the one-clock-per-node style that are outdated.
5378 * Those bindings typically put all clock data into .dts and the Linux
5379 * driver has no clock data, thus making it impossible to set this flag
5380 * correctly from the driver. Only those drivers may call
5381 * of_clk_detect_critical from their setup functions.
5382 *
5383 * Return: error code or zero on success
5384 */
5385int of_clk_detect_critical(struct device_node *np, int index,
5386 unsigned long *flags)
5387{
5388 struct property *prop;
5389 const __be32 *cur;
5390 uint32_t idx;
5391
5392 if (!np || !flags)
5393 return -EINVAL;
5394
5395 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
5396 if (index == idx)
5397 *flags |= CLK_IS_CRITICAL;
5398
5399 return 0;
5400}
5401
5402/**
5403 * of_clk_init() - Scan and init clock providers from the DT
5404 * @matches: array of compatible values and init functions for providers.
5405 *
5406 * This function scans the device tree for matching clock providers
5407 * and calls their initialization functions. It also does it by trying
5408 * to follow the dependencies.
5409 */
5410void __init of_clk_init(const struct of_device_id *matches)
5411{
5412 const struct of_device_id *match;
5413 struct device_node *np;
5414 struct clock_provider *clk_provider, *next;
5415 bool is_init_done;
5416 bool force = false;
5417 LIST_HEAD(clk_provider_list);
5418
5419 if (!matches)
5420 matches = &__clk_of_table;
5421
5422 /* First prepare the list of the clocks providers */
5423 for_each_matching_node_and_match(np, matches, &match) {
5424 struct clock_provider *parent;
5425
5426 if (!of_device_is_available(np))
5427 continue;
5428
5429 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
5430 if (!parent) {
5431 list_for_each_entry_safe(clk_provider, next,
5432 &clk_provider_list, node) {
5433 list_del(&clk_provider->node);
5434 of_node_put(clk_provider->np);
5435 kfree(clk_provider);
5436 }
5437 of_node_put(np);
5438 return;
5439 }
5440
5441 parent->clk_init_cb = match->data;
5442 parent->np = of_node_get(np);
5443 list_add_tail(&parent->node, &clk_provider_list);
5444 }
5445
5446 while (!list_empty(&clk_provider_list)) {
5447 is_init_done = false;
5448 list_for_each_entry_safe(clk_provider, next,
5449 &clk_provider_list, node) {
5450 if (force || parent_ready(clk_provider->np)) {
5451
5452 /* Don't populate platform devices */
5453 of_node_set_flag(clk_provider->np,
5454 OF_POPULATED);
5455
5456 clk_provider->clk_init_cb(clk_provider->np);
5457 of_clk_set_defaults(clk_provider->np, true);
5458
5459 list_del(&clk_provider->node);
5460 of_node_put(clk_provider->np);
5461 kfree(clk_provider);
5462 is_init_done = true;
5463 }
5464 }
5465
5466 /*
5467 * We didn't manage to initialize any of the
5468 * remaining providers during the last loop, so now we
5469 * initialize all the remaining ones unconditionally
5470 * in case the clock parent was not mandatory
5471 */
5472 if (!is_init_done)
5473 force = true;
5474 }
5475}
5476#endif
1/*
2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
4 *
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.
8 *
9 * Standard functionality for the common clock API. See Documentation/clk.txt
10 */
11
12#include <linux/clk.h>
13#include <linux/clk-provider.h>
14#include <linux/clk/clk-conf.h>
15#include <linux/module.h>
16#include <linux/mutex.h>
17#include <linux/spinlock.h>
18#include <linux/err.h>
19#include <linux/list.h>
20#include <linux/slab.h>
21#include <linux/of.h>
22#include <linux/device.h>
23#include <linux/init.h>
24#include <linux/sched.h>
25#include <linux/clkdev.h>
26
27#include "clk.h"
28
29static DEFINE_SPINLOCK(enable_lock);
30static DEFINE_MUTEX(prepare_lock);
31
32static struct task_struct *prepare_owner;
33static struct task_struct *enable_owner;
34
35static int prepare_refcnt;
36static int enable_refcnt;
37
38static HLIST_HEAD(clk_root_list);
39static HLIST_HEAD(clk_orphan_list);
40static LIST_HEAD(clk_notifier_list);
41
42/*** private data structures ***/
43
44struct clk_core {
45 const char *name;
46 const struct clk_ops *ops;
47 struct clk_hw *hw;
48 struct module *owner;
49 struct clk_core *parent;
50 const char **parent_names;
51 struct clk_core **parents;
52 u8 num_parents;
53 u8 new_parent_index;
54 unsigned long rate;
55 unsigned long req_rate;
56 unsigned long new_rate;
57 struct clk_core *new_parent;
58 struct clk_core *new_child;
59 unsigned long flags;
60 bool orphan;
61 unsigned int enable_count;
62 unsigned int prepare_count;
63 unsigned long min_rate;
64 unsigned long max_rate;
65 unsigned long accuracy;
66 int phase;
67 struct hlist_head children;
68 struct hlist_node child_node;
69 struct hlist_head clks;
70 unsigned int notifier_count;
71#ifdef CONFIG_DEBUG_FS
72 struct dentry *dentry;
73 struct hlist_node debug_node;
74#endif
75 struct kref ref;
76};
77
78#define CREATE_TRACE_POINTS
79#include <trace/events/clk.h>
80
81struct clk {
82 struct clk_core *core;
83 const char *dev_id;
84 const char *con_id;
85 unsigned long min_rate;
86 unsigned long max_rate;
87 struct hlist_node clks_node;
88};
89
90/*** locking ***/
91static void clk_prepare_lock(void)
92{
93 if (!mutex_trylock(&prepare_lock)) {
94 if (prepare_owner == current) {
95 prepare_refcnt++;
96 return;
97 }
98 mutex_lock(&prepare_lock);
99 }
100 WARN_ON_ONCE(prepare_owner != NULL);
101 WARN_ON_ONCE(prepare_refcnt != 0);
102 prepare_owner = current;
103 prepare_refcnt = 1;
104}
105
106static void clk_prepare_unlock(void)
107{
108 WARN_ON_ONCE(prepare_owner != current);
109 WARN_ON_ONCE(prepare_refcnt == 0);
110
111 if (--prepare_refcnt)
112 return;
113 prepare_owner = NULL;
114 mutex_unlock(&prepare_lock);
115}
116
117static unsigned long clk_enable_lock(void)
118 __acquires(enable_lock)
119{
120 unsigned long flags;
121
122 if (!spin_trylock_irqsave(&enable_lock, flags)) {
123 if (enable_owner == current) {
124 enable_refcnt++;
125 __acquire(enable_lock);
126 return flags;
127 }
128 spin_lock_irqsave(&enable_lock, flags);
129 }
130 WARN_ON_ONCE(enable_owner != NULL);
131 WARN_ON_ONCE(enable_refcnt != 0);
132 enable_owner = current;
133 enable_refcnt = 1;
134 return flags;
135}
136
137static void clk_enable_unlock(unsigned long flags)
138 __releases(enable_lock)
139{
140 WARN_ON_ONCE(enable_owner != current);
141 WARN_ON_ONCE(enable_refcnt == 0);
142
143 if (--enable_refcnt) {
144 __release(enable_lock);
145 return;
146 }
147 enable_owner = NULL;
148 spin_unlock_irqrestore(&enable_lock, flags);
149}
150
151static bool clk_core_is_prepared(struct clk_core *core)
152{
153 /*
154 * .is_prepared is optional for clocks that can prepare
155 * fall back to software usage counter if it is missing
156 */
157 if (!core->ops->is_prepared)
158 return core->prepare_count;
159
160 return core->ops->is_prepared(core->hw);
161}
162
163static bool clk_core_is_enabled(struct clk_core *core)
164{
165 /*
166 * .is_enabled is only mandatory for clocks that gate
167 * fall back to software usage counter if .is_enabled is missing
168 */
169 if (!core->ops->is_enabled)
170 return core->enable_count;
171
172 return core->ops->is_enabled(core->hw);
173}
174
175/*** helper functions ***/
176
177const char *__clk_get_name(const struct clk *clk)
178{
179 return !clk ? NULL : clk->core->name;
180}
181EXPORT_SYMBOL_GPL(__clk_get_name);
182
183const char *clk_hw_get_name(const struct clk_hw *hw)
184{
185 return hw->core->name;
186}
187EXPORT_SYMBOL_GPL(clk_hw_get_name);
188
189struct clk_hw *__clk_get_hw(struct clk *clk)
190{
191 return !clk ? NULL : clk->core->hw;
192}
193EXPORT_SYMBOL_GPL(__clk_get_hw);
194
195unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
196{
197 return hw->core->num_parents;
198}
199EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
200
201struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
202{
203 return hw->core->parent ? hw->core->parent->hw : NULL;
204}
205EXPORT_SYMBOL_GPL(clk_hw_get_parent);
206
207static struct clk_core *__clk_lookup_subtree(const char *name,
208 struct clk_core *core)
209{
210 struct clk_core *child;
211 struct clk_core *ret;
212
213 if (!strcmp(core->name, name))
214 return core;
215
216 hlist_for_each_entry(child, &core->children, child_node) {
217 ret = __clk_lookup_subtree(name, child);
218 if (ret)
219 return ret;
220 }
221
222 return NULL;
223}
224
225static struct clk_core *clk_core_lookup(const char *name)
226{
227 struct clk_core *root_clk;
228 struct clk_core *ret;
229
230 if (!name)
231 return NULL;
232
233 /* search the 'proper' clk tree first */
234 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
235 ret = __clk_lookup_subtree(name, root_clk);
236 if (ret)
237 return ret;
238 }
239
240 /* if not found, then search the orphan tree */
241 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
242 ret = __clk_lookup_subtree(name, root_clk);
243 if (ret)
244 return ret;
245 }
246
247 return NULL;
248}
249
250static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
251 u8 index)
252{
253 if (!core || index >= core->num_parents)
254 return NULL;
255
256 if (!core->parents[index])
257 core->parents[index] =
258 clk_core_lookup(core->parent_names[index]);
259
260 return core->parents[index];
261}
262
263struct clk_hw *
264clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
265{
266 struct clk_core *parent;
267
268 parent = clk_core_get_parent_by_index(hw->core, index);
269
270 return !parent ? NULL : parent->hw;
271}
272EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
273
274unsigned int __clk_get_enable_count(struct clk *clk)
275{
276 return !clk ? 0 : clk->core->enable_count;
277}
278
279static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
280{
281 unsigned long ret;
282
283 if (!core) {
284 ret = 0;
285 goto out;
286 }
287
288 ret = core->rate;
289
290 if (!core->num_parents)
291 goto out;
292
293 if (!core->parent)
294 ret = 0;
295
296out:
297 return ret;
298}
299
300unsigned long clk_hw_get_rate(const struct clk_hw *hw)
301{
302 return clk_core_get_rate_nolock(hw->core);
303}
304EXPORT_SYMBOL_GPL(clk_hw_get_rate);
305
306static unsigned long __clk_get_accuracy(struct clk_core *core)
307{
308 if (!core)
309 return 0;
310
311 return core->accuracy;
312}
313
314unsigned long __clk_get_flags(struct clk *clk)
315{
316 return !clk ? 0 : clk->core->flags;
317}
318EXPORT_SYMBOL_GPL(__clk_get_flags);
319
320unsigned long clk_hw_get_flags(const struct clk_hw *hw)
321{
322 return hw->core->flags;
323}
324EXPORT_SYMBOL_GPL(clk_hw_get_flags);
325
326bool clk_hw_is_prepared(const struct clk_hw *hw)
327{
328 return clk_core_is_prepared(hw->core);
329}
330
331bool clk_hw_is_enabled(const struct clk_hw *hw)
332{
333 return clk_core_is_enabled(hw->core);
334}
335
336bool __clk_is_enabled(struct clk *clk)
337{
338 if (!clk)
339 return false;
340
341 return clk_core_is_enabled(clk->core);
342}
343EXPORT_SYMBOL_GPL(__clk_is_enabled);
344
345static bool mux_is_better_rate(unsigned long rate, unsigned long now,
346 unsigned long best, unsigned long flags)
347{
348 if (flags & CLK_MUX_ROUND_CLOSEST)
349 return abs(now - rate) < abs(best - rate);
350
351 return now <= rate && now > best;
352}
353
354static int
355clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
356 unsigned long flags)
357{
358 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
359 int i, num_parents, ret;
360 unsigned long best = 0;
361 struct clk_rate_request parent_req = *req;
362
363 /* if NO_REPARENT flag set, pass through to current parent */
364 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
365 parent = core->parent;
366 if (core->flags & CLK_SET_RATE_PARENT) {
367 ret = __clk_determine_rate(parent ? parent->hw : NULL,
368 &parent_req);
369 if (ret)
370 return ret;
371
372 best = parent_req.rate;
373 } else if (parent) {
374 best = clk_core_get_rate_nolock(parent);
375 } else {
376 best = clk_core_get_rate_nolock(core);
377 }
378
379 goto out;
380 }
381
382 /* find the parent that can provide the fastest rate <= rate */
383 num_parents = core->num_parents;
384 for (i = 0; i < num_parents; i++) {
385 parent = clk_core_get_parent_by_index(core, i);
386 if (!parent)
387 continue;
388
389 if (core->flags & CLK_SET_RATE_PARENT) {
390 parent_req = *req;
391 ret = __clk_determine_rate(parent->hw, &parent_req);
392 if (ret)
393 continue;
394 } else {
395 parent_req.rate = clk_core_get_rate_nolock(parent);
396 }
397
398 if (mux_is_better_rate(req->rate, parent_req.rate,
399 best, flags)) {
400 best_parent = parent;
401 best = parent_req.rate;
402 }
403 }
404
405 if (!best_parent)
406 return -EINVAL;
407
408out:
409 if (best_parent)
410 req->best_parent_hw = best_parent->hw;
411 req->best_parent_rate = best;
412 req->rate = best;
413
414 return 0;
415}
416
417struct clk *__clk_lookup(const char *name)
418{
419 struct clk_core *core = clk_core_lookup(name);
420
421 return !core ? NULL : core->hw->clk;
422}
423
424static void clk_core_get_boundaries(struct clk_core *core,
425 unsigned long *min_rate,
426 unsigned long *max_rate)
427{
428 struct clk *clk_user;
429
430 *min_rate = core->min_rate;
431 *max_rate = core->max_rate;
432
433 hlist_for_each_entry(clk_user, &core->clks, clks_node)
434 *min_rate = max(*min_rate, clk_user->min_rate);
435
436 hlist_for_each_entry(clk_user, &core->clks, clks_node)
437 *max_rate = min(*max_rate, clk_user->max_rate);
438}
439
440void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
441 unsigned long max_rate)
442{
443 hw->core->min_rate = min_rate;
444 hw->core->max_rate = max_rate;
445}
446EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
447
448/*
449 * Helper for finding best parent to provide a given frequency. This can be used
450 * directly as a determine_rate callback (e.g. for a mux), or from a more
451 * complex clock that may combine a mux with other operations.
452 */
453int __clk_mux_determine_rate(struct clk_hw *hw,
454 struct clk_rate_request *req)
455{
456 return clk_mux_determine_rate_flags(hw, req, 0);
457}
458EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
459
460int __clk_mux_determine_rate_closest(struct clk_hw *hw,
461 struct clk_rate_request *req)
462{
463 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
464}
465EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
466
467/*** clk api ***/
468
469static void clk_core_unprepare(struct clk_core *core)
470{
471 lockdep_assert_held(&prepare_lock);
472
473 if (!core)
474 return;
475
476 if (WARN_ON(core->prepare_count == 0))
477 return;
478
479 if (WARN_ON(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL))
480 return;
481
482 if (--core->prepare_count > 0)
483 return;
484
485 WARN_ON(core->enable_count > 0);
486
487 trace_clk_unprepare(core);
488
489 if (core->ops->unprepare)
490 core->ops->unprepare(core->hw);
491
492 trace_clk_unprepare_complete(core);
493 clk_core_unprepare(core->parent);
494}
495
496static void clk_core_unprepare_lock(struct clk_core *core)
497{
498 clk_prepare_lock();
499 clk_core_unprepare(core);
500 clk_prepare_unlock();
501}
502
503/**
504 * clk_unprepare - undo preparation of a clock source
505 * @clk: the clk being unprepared
506 *
507 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
508 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
509 * if the operation may sleep. One example is a clk which is accessed over
510 * I2c. In the complex case a clk gate operation may require a fast and a slow
511 * part. It is this reason that clk_unprepare and clk_disable are not mutually
512 * exclusive. In fact clk_disable must be called before clk_unprepare.
513 */
514void clk_unprepare(struct clk *clk)
515{
516 if (IS_ERR_OR_NULL(clk))
517 return;
518
519 clk_core_unprepare_lock(clk->core);
520}
521EXPORT_SYMBOL_GPL(clk_unprepare);
522
523static int clk_core_prepare(struct clk_core *core)
524{
525 int ret = 0;
526
527 lockdep_assert_held(&prepare_lock);
528
529 if (!core)
530 return 0;
531
532 if (core->prepare_count == 0) {
533 ret = clk_core_prepare(core->parent);
534 if (ret)
535 return ret;
536
537 trace_clk_prepare(core);
538
539 if (core->ops->prepare)
540 ret = core->ops->prepare(core->hw);
541
542 trace_clk_prepare_complete(core);
543
544 if (ret) {
545 clk_core_unprepare(core->parent);
546 return ret;
547 }
548 }
549
550 core->prepare_count++;
551
552 return 0;
553}
554
555static int clk_core_prepare_lock(struct clk_core *core)
556{
557 int ret;
558
559 clk_prepare_lock();
560 ret = clk_core_prepare(core);
561 clk_prepare_unlock();
562
563 return ret;
564}
565
566/**
567 * clk_prepare - prepare a clock source
568 * @clk: the clk being prepared
569 *
570 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
571 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
572 * operation may sleep. One example is a clk which is accessed over I2c. In
573 * the complex case a clk ungate operation may require a fast and a slow part.
574 * It is this reason that clk_prepare and clk_enable are not mutually
575 * exclusive. In fact clk_prepare must be called before clk_enable.
576 * Returns 0 on success, -EERROR otherwise.
577 */
578int clk_prepare(struct clk *clk)
579{
580 if (!clk)
581 return 0;
582
583 return clk_core_prepare_lock(clk->core);
584}
585EXPORT_SYMBOL_GPL(clk_prepare);
586
587static void clk_core_disable(struct clk_core *core)
588{
589 lockdep_assert_held(&enable_lock);
590
591 if (!core)
592 return;
593
594 if (WARN_ON(core->enable_count == 0))
595 return;
596
597 if (WARN_ON(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL))
598 return;
599
600 if (--core->enable_count > 0)
601 return;
602
603 trace_clk_disable_rcuidle(core);
604
605 if (core->ops->disable)
606 core->ops->disable(core->hw);
607
608 trace_clk_disable_complete_rcuidle(core);
609
610 clk_core_disable(core->parent);
611}
612
613static void clk_core_disable_lock(struct clk_core *core)
614{
615 unsigned long flags;
616
617 flags = clk_enable_lock();
618 clk_core_disable(core);
619 clk_enable_unlock(flags);
620}
621
622/**
623 * clk_disable - gate a clock
624 * @clk: the clk being gated
625 *
626 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
627 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
628 * clk if the operation is fast and will never sleep. One example is a
629 * SoC-internal clk which is controlled via simple register writes. In the
630 * complex case a clk gate operation may require a fast and a slow part. It is
631 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
632 * In fact clk_disable must be called before clk_unprepare.
633 */
634void clk_disable(struct clk *clk)
635{
636 if (IS_ERR_OR_NULL(clk))
637 return;
638
639 clk_core_disable_lock(clk->core);
640}
641EXPORT_SYMBOL_GPL(clk_disable);
642
643static int clk_core_enable(struct clk_core *core)
644{
645 int ret = 0;
646
647 lockdep_assert_held(&enable_lock);
648
649 if (!core)
650 return 0;
651
652 if (WARN_ON(core->prepare_count == 0))
653 return -ESHUTDOWN;
654
655 if (core->enable_count == 0) {
656 ret = clk_core_enable(core->parent);
657
658 if (ret)
659 return ret;
660
661 trace_clk_enable_rcuidle(core);
662
663 if (core->ops->enable)
664 ret = core->ops->enable(core->hw);
665
666 trace_clk_enable_complete_rcuidle(core);
667
668 if (ret) {
669 clk_core_disable(core->parent);
670 return ret;
671 }
672 }
673
674 core->enable_count++;
675 return 0;
676}
677
678static int clk_core_enable_lock(struct clk_core *core)
679{
680 unsigned long flags;
681 int ret;
682
683 flags = clk_enable_lock();
684 ret = clk_core_enable(core);
685 clk_enable_unlock(flags);
686
687 return ret;
688}
689
690/**
691 * clk_enable - ungate a clock
692 * @clk: the clk being ungated
693 *
694 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
695 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
696 * if the operation will never sleep. One example is a SoC-internal clk which
697 * is controlled via simple register writes. In the complex case a clk ungate
698 * operation may require a fast and a slow part. It is this reason that
699 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
700 * must be called before clk_enable. Returns 0 on success, -EERROR
701 * otherwise.
702 */
703int clk_enable(struct clk *clk)
704{
705 if (!clk)
706 return 0;
707
708 return clk_core_enable_lock(clk->core);
709}
710EXPORT_SYMBOL_GPL(clk_enable);
711
712static int clk_core_prepare_enable(struct clk_core *core)
713{
714 int ret;
715
716 ret = clk_core_prepare_lock(core);
717 if (ret)
718 return ret;
719
720 ret = clk_core_enable_lock(core);
721 if (ret)
722 clk_core_unprepare_lock(core);
723
724 return ret;
725}
726
727static void clk_core_disable_unprepare(struct clk_core *core)
728{
729 clk_core_disable_lock(core);
730 clk_core_unprepare_lock(core);
731}
732
733static void clk_unprepare_unused_subtree(struct clk_core *core)
734{
735 struct clk_core *child;
736
737 lockdep_assert_held(&prepare_lock);
738
739 hlist_for_each_entry(child, &core->children, child_node)
740 clk_unprepare_unused_subtree(child);
741
742 if (core->prepare_count)
743 return;
744
745 if (core->flags & CLK_IGNORE_UNUSED)
746 return;
747
748 if (clk_core_is_prepared(core)) {
749 trace_clk_unprepare(core);
750 if (core->ops->unprepare_unused)
751 core->ops->unprepare_unused(core->hw);
752 else if (core->ops->unprepare)
753 core->ops->unprepare(core->hw);
754 trace_clk_unprepare_complete(core);
755 }
756}
757
758static void clk_disable_unused_subtree(struct clk_core *core)
759{
760 struct clk_core *child;
761 unsigned long flags;
762
763 lockdep_assert_held(&prepare_lock);
764
765 hlist_for_each_entry(child, &core->children, child_node)
766 clk_disable_unused_subtree(child);
767
768 if (core->flags & CLK_OPS_PARENT_ENABLE)
769 clk_core_prepare_enable(core->parent);
770
771 flags = clk_enable_lock();
772
773 if (core->enable_count)
774 goto unlock_out;
775
776 if (core->flags & CLK_IGNORE_UNUSED)
777 goto unlock_out;
778
779 /*
780 * some gate clocks have special needs during the disable-unused
781 * sequence. call .disable_unused if available, otherwise fall
782 * back to .disable
783 */
784 if (clk_core_is_enabled(core)) {
785 trace_clk_disable(core);
786 if (core->ops->disable_unused)
787 core->ops->disable_unused(core->hw);
788 else if (core->ops->disable)
789 core->ops->disable(core->hw);
790 trace_clk_disable_complete(core);
791 }
792
793unlock_out:
794 clk_enable_unlock(flags);
795 if (core->flags & CLK_OPS_PARENT_ENABLE)
796 clk_core_disable_unprepare(core->parent);
797}
798
799static bool clk_ignore_unused;
800static int __init clk_ignore_unused_setup(char *__unused)
801{
802 clk_ignore_unused = true;
803 return 1;
804}
805__setup("clk_ignore_unused", clk_ignore_unused_setup);
806
807static int clk_disable_unused(void)
808{
809 struct clk_core *core;
810
811 if (clk_ignore_unused) {
812 pr_warn("clk: Not disabling unused clocks\n");
813 return 0;
814 }
815
816 clk_prepare_lock();
817
818 hlist_for_each_entry(core, &clk_root_list, child_node)
819 clk_disable_unused_subtree(core);
820
821 hlist_for_each_entry(core, &clk_orphan_list, child_node)
822 clk_disable_unused_subtree(core);
823
824 hlist_for_each_entry(core, &clk_root_list, child_node)
825 clk_unprepare_unused_subtree(core);
826
827 hlist_for_each_entry(core, &clk_orphan_list, child_node)
828 clk_unprepare_unused_subtree(core);
829
830 clk_prepare_unlock();
831
832 return 0;
833}
834late_initcall_sync(clk_disable_unused);
835
836static int clk_core_round_rate_nolock(struct clk_core *core,
837 struct clk_rate_request *req)
838{
839 struct clk_core *parent;
840 long rate;
841
842 lockdep_assert_held(&prepare_lock);
843
844 if (!core)
845 return 0;
846
847 parent = core->parent;
848 if (parent) {
849 req->best_parent_hw = parent->hw;
850 req->best_parent_rate = parent->rate;
851 } else {
852 req->best_parent_hw = NULL;
853 req->best_parent_rate = 0;
854 }
855
856 if (core->ops->determine_rate) {
857 return core->ops->determine_rate(core->hw, req);
858 } else if (core->ops->round_rate) {
859 rate = core->ops->round_rate(core->hw, req->rate,
860 &req->best_parent_rate);
861 if (rate < 0)
862 return rate;
863
864 req->rate = rate;
865 } else if (core->flags & CLK_SET_RATE_PARENT) {
866 return clk_core_round_rate_nolock(parent, req);
867 } else {
868 req->rate = core->rate;
869 }
870
871 return 0;
872}
873
874/**
875 * __clk_determine_rate - get the closest rate actually supported by a clock
876 * @hw: determine the rate of this clock
877 * @req: target rate request
878 *
879 * Useful for clk_ops such as .set_rate and .determine_rate.
880 */
881int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
882{
883 if (!hw) {
884 req->rate = 0;
885 return 0;
886 }
887
888 return clk_core_round_rate_nolock(hw->core, req);
889}
890EXPORT_SYMBOL_GPL(__clk_determine_rate);
891
892unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
893{
894 int ret;
895 struct clk_rate_request req;
896
897 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
898 req.rate = rate;
899
900 ret = clk_core_round_rate_nolock(hw->core, &req);
901 if (ret)
902 return 0;
903
904 return req.rate;
905}
906EXPORT_SYMBOL_GPL(clk_hw_round_rate);
907
908/**
909 * clk_round_rate - round the given rate for a clk
910 * @clk: the clk for which we are rounding a rate
911 * @rate: the rate which is to be rounded
912 *
913 * Takes in a rate as input and rounds it to a rate that the clk can actually
914 * use which is then returned. If clk doesn't support round_rate operation
915 * then the parent rate is returned.
916 */
917long clk_round_rate(struct clk *clk, unsigned long rate)
918{
919 struct clk_rate_request req;
920 int ret;
921
922 if (!clk)
923 return 0;
924
925 clk_prepare_lock();
926
927 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
928 req.rate = rate;
929
930 ret = clk_core_round_rate_nolock(clk->core, &req);
931 clk_prepare_unlock();
932
933 if (ret)
934 return ret;
935
936 return req.rate;
937}
938EXPORT_SYMBOL_GPL(clk_round_rate);
939
940/**
941 * __clk_notify - call clk notifier chain
942 * @core: clk that is changing rate
943 * @msg: clk notifier type (see include/linux/clk.h)
944 * @old_rate: old clk rate
945 * @new_rate: new clk rate
946 *
947 * Triggers a notifier call chain on the clk rate-change notification
948 * for 'clk'. Passes a pointer to the struct clk and the previous
949 * and current rates to the notifier callback. Intended to be called by
950 * internal clock code only. Returns NOTIFY_DONE from the last driver
951 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
952 * a driver returns that.
953 */
954static int __clk_notify(struct clk_core *core, unsigned long msg,
955 unsigned long old_rate, unsigned long new_rate)
956{
957 struct clk_notifier *cn;
958 struct clk_notifier_data cnd;
959 int ret = NOTIFY_DONE;
960
961 cnd.old_rate = old_rate;
962 cnd.new_rate = new_rate;
963
964 list_for_each_entry(cn, &clk_notifier_list, node) {
965 if (cn->clk->core == core) {
966 cnd.clk = cn->clk;
967 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
968 &cnd);
969 }
970 }
971
972 return ret;
973}
974
975/**
976 * __clk_recalc_accuracies
977 * @core: first clk in the subtree
978 *
979 * Walks the subtree of clks starting with clk and recalculates accuracies as
980 * it goes. Note that if a clk does not implement the .recalc_accuracy
981 * callback then it is assumed that the clock will take on the accuracy of its
982 * parent.
983 */
984static void __clk_recalc_accuracies(struct clk_core *core)
985{
986 unsigned long parent_accuracy = 0;
987 struct clk_core *child;
988
989 lockdep_assert_held(&prepare_lock);
990
991 if (core->parent)
992 parent_accuracy = core->parent->accuracy;
993
994 if (core->ops->recalc_accuracy)
995 core->accuracy = core->ops->recalc_accuracy(core->hw,
996 parent_accuracy);
997 else
998 core->accuracy = parent_accuracy;
999
1000 hlist_for_each_entry(child, &core->children, child_node)
1001 __clk_recalc_accuracies(child);
1002}
1003
1004static long clk_core_get_accuracy(struct clk_core *core)
1005{
1006 unsigned long accuracy;
1007
1008 clk_prepare_lock();
1009 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1010 __clk_recalc_accuracies(core);
1011
1012 accuracy = __clk_get_accuracy(core);
1013 clk_prepare_unlock();
1014
1015 return accuracy;
1016}
1017
1018/**
1019 * clk_get_accuracy - return the accuracy of clk
1020 * @clk: the clk whose accuracy is being returned
1021 *
1022 * Simply returns the cached accuracy of the clk, unless
1023 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1024 * issued.
1025 * If clk is NULL then returns 0.
1026 */
1027long clk_get_accuracy(struct clk *clk)
1028{
1029 if (!clk)
1030 return 0;
1031
1032 return clk_core_get_accuracy(clk->core);
1033}
1034EXPORT_SYMBOL_GPL(clk_get_accuracy);
1035
1036static unsigned long clk_recalc(struct clk_core *core,
1037 unsigned long parent_rate)
1038{
1039 if (core->ops->recalc_rate)
1040 return core->ops->recalc_rate(core->hw, parent_rate);
1041 return parent_rate;
1042}
1043
1044/**
1045 * __clk_recalc_rates
1046 * @core: first clk in the subtree
1047 * @msg: notification type (see include/linux/clk.h)
1048 *
1049 * Walks the subtree of clks starting with clk and recalculates rates as it
1050 * goes. Note that if a clk does not implement the .recalc_rate callback then
1051 * it is assumed that the clock will take on the rate of its parent.
1052 *
1053 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1054 * if necessary.
1055 */
1056static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1057{
1058 unsigned long old_rate;
1059 unsigned long parent_rate = 0;
1060 struct clk_core *child;
1061
1062 lockdep_assert_held(&prepare_lock);
1063
1064 old_rate = core->rate;
1065
1066 if (core->parent)
1067 parent_rate = core->parent->rate;
1068
1069 core->rate = clk_recalc(core, parent_rate);
1070
1071 /*
1072 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1073 * & ABORT_RATE_CHANGE notifiers
1074 */
1075 if (core->notifier_count && msg)
1076 __clk_notify(core, msg, old_rate, core->rate);
1077
1078 hlist_for_each_entry(child, &core->children, child_node)
1079 __clk_recalc_rates(child, msg);
1080}
1081
1082static unsigned long clk_core_get_rate(struct clk_core *core)
1083{
1084 unsigned long rate;
1085
1086 clk_prepare_lock();
1087
1088 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1089 __clk_recalc_rates(core, 0);
1090
1091 rate = clk_core_get_rate_nolock(core);
1092 clk_prepare_unlock();
1093
1094 return rate;
1095}
1096
1097/**
1098 * clk_get_rate - return the rate of clk
1099 * @clk: the clk whose rate is being returned
1100 *
1101 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1102 * is set, which means a recalc_rate will be issued.
1103 * If clk is NULL then returns 0.
1104 */
1105unsigned long clk_get_rate(struct clk *clk)
1106{
1107 if (!clk)
1108 return 0;
1109
1110 return clk_core_get_rate(clk->core);
1111}
1112EXPORT_SYMBOL_GPL(clk_get_rate);
1113
1114static int clk_fetch_parent_index(struct clk_core *core,
1115 struct clk_core *parent)
1116{
1117 int i;
1118
1119 if (!parent)
1120 return -EINVAL;
1121
1122 for (i = 0; i < core->num_parents; i++)
1123 if (clk_core_get_parent_by_index(core, i) == parent)
1124 return i;
1125
1126 return -EINVAL;
1127}
1128
1129/*
1130 * Update the orphan status of @core and all its children.
1131 */
1132static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1133{
1134 struct clk_core *child;
1135
1136 core->orphan = is_orphan;
1137
1138 hlist_for_each_entry(child, &core->children, child_node)
1139 clk_core_update_orphan_status(child, is_orphan);
1140}
1141
1142static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1143{
1144 bool was_orphan = core->orphan;
1145
1146 hlist_del(&core->child_node);
1147
1148 if (new_parent) {
1149 bool becomes_orphan = new_parent->orphan;
1150
1151 /* avoid duplicate POST_RATE_CHANGE notifications */
1152 if (new_parent->new_child == core)
1153 new_parent->new_child = NULL;
1154
1155 hlist_add_head(&core->child_node, &new_parent->children);
1156
1157 if (was_orphan != becomes_orphan)
1158 clk_core_update_orphan_status(core, becomes_orphan);
1159 } else {
1160 hlist_add_head(&core->child_node, &clk_orphan_list);
1161 if (!was_orphan)
1162 clk_core_update_orphan_status(core, true);
1163 }
1164
1165 core->parent = new_parent;
1166}
1167
1168static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1169 struct clk_core *parent)
1170{
1171 unsigned long flags;
1172 struct clk_core *old_parent = core->parent;
1173
1174 /*
1175 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
1176 *
1177 * 2. Migrate prepare state between parents and prevent race with
1178 * clk_enable().
1179 *
1180 * If the clock is not prepared, then a race with
1181 * clk_enable/disable() is impossible since we already have the
1182 * prepare lock (future calls to clk_enable() need to be preceded by
1183 * a clk_prepare()).
1184 *
1185 * If the clock is prepared, migrate the prepared state to the new
1186 * parent and also protect against a race with clk_enable() by
1187 * forcing the clock and the new parent on. This ensures that all
1188 * future calls to clk_enable() are practically NOPs with respect to
1189 * hardware and software states.
1190 *
1191 * See also: Comment for clk_set_parent() below.
1192 */
1193
1194 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
1195 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1196 clk_core_prepare_enable(old_parent);
1197 clk_core_prepare_enable(parent);
1198 }
1199
1200 /* migrate prepare count if > 0 */
1201 if (core->prepare_count) {
1202 clk_core_prepare_enable(parent);
1203 clk_core_enable_lock(core);
1204 }
1205
1206 /* update the clk tree topology */
1207 flags = clk_enable_lock();
1208 clk_reparent(core, parent);
1209 clk_enable_unlock(flags);
1210
1211 return old_parent;
1212}
1213
1214static void __clk_set_parent_after(struct clk_core *core,
1215 struct clk_core *parent,
1216 struct clk_core *old_parent)
1217{
1218 /*
1219 * Finish the migration of prepare state and undo the changes done
1220 * for preventing a race with clk_enable().
1221 */
1222 if (core->prepare_count) {
1223 clk_core_disable_lock(core);
1224 clk_core_disable_unprepare(old_parent);
1225 }
1226
1227 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
1228 if (core->flags & CLK_OPS_PARENT_ENABLE) {
1229 clk_core_disable_unprepare(parent);
1230 clk_core_disable_unprepare(old_parent);
1231 }
1232}
1233
1234static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1235 u8 p_index)
1236{
1237 unsigned long flags;
1238 int ret = 0;
1239 struct clk_core *old_parent;
1240
1241 old_parent = __clk_set_parent_before(core, parent);
1242
1243 trace_clk_set_parent(core, parent);
1244
1245 /* change clock input source */
1246 if (parent && core->ops->set_parent)
1247 ret = core->ops->set_parent(core->hw, p_index);
1248
1249 trace_clk_set_parent_complete(core, parent);
1250
1251 if (ret) {
1252 flags = clk_enable_lock();
1253 clk_reparent(core, old_parent);
1254 clk_enable_unlock(flags);
1255 __clk_set_parent_after(core, old_parent, parent);
1256
1257 return ret;
1258 }
1259
1260 __clk_set_parent_after(core, parent, old_parent);
1261
1262 return 0;
1263}
1264
1265/**
1266 * __clk_speculate_rates
1267 * @core: first clk in the subtree
1268 * @parent_rate: the "future" rate of clk's parent
1269 *
1270 * Walks the subtree of clks starting with clk, speculating rates as it
1271 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1272 *
1273 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1274 * pre-rate change notifications and returns early if no clks in the
1275 * subtree have subscribed to the notifications. Note that if a clk does not
1276 * implement the .recalc_rate callback then it is assumed that the clock will
1277 * take on the rate of its parent.
1278 */
1279static int __clk_speculate_rates(struct clk_core *core,
1280 unsigned long parent_rate)
1281{
1282 struct clk_core *child;
1283 unsigned long new_rate;
1284 int ret = NOTIFY_DONE;
1285
1286 lockdep_assert_held(&prepare_lock);
1287
1288 new_rate = clk_recalc(core, parent_rate);
1289
1290 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1291 if (core->notifier_count)
1292 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1293
1294 if (ret & NOTIFY_STOP_MASK) {
1295 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1296 __func__, core->name, ret);
1297 goto out;
1298 }
1299
1300 hlist_for_each_entry(child, &core->children, child_node) {
1301 ret = __clk_speculate_rates(child, new_rate);
1302 if (ret & NOTIFY_STOP_MASK)
1303 break;
1304 }
1305
1306out:
1307 return ret;
1308}
1309
1310static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1311 struct clk_core *new_parent, u8 p_index)
1312{
1313 struct clk_core *child;
1314
1315 core->new_rate = new_rate;
1316 core->new_parent = new_parent;
1317 core->new_parent_index = p_index;
1318 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1319 core->new_child = NULL;
1320 if (new_parent && new_parent != core->parent)
1321 new_parent->new_child = core;
1322
1323 hlist_for_each_entry(child, &core->children, child_node) {
1324 child->new_rate = clk_recalc(child, new_rate);
1325 clk_calc_subtree(child, child->new_rate, NULL, 0);
1326 }
1327}
1328
1329/*
1330 * calculate the new rates returning the topmost clock that has to be
1331 * changed.
1332 */
1333static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1334 unsigned long rate)
1335{
1336 struct clk_core *top = core;
1337 struct clk_core *old_parent, *parent;
1338 unsigned long best_parent_rate = 0;
1339 unsigned long new_rate;
1340 unsigned long min_rate;
1341 unsigned long max_rate;
1342 int p_index = 0;
1343 long ret;
1344
1345 /* sanity */
1346 if (IS_ERR_OR_NULL(core))
1347 return NULL;
1348
1349 /* save parent rate, if it exists */
1350 parent = old_parent = core->parent;
1351 if (parent)
1352 best_parent_rate = parent->rate;
1353
1354 clk_core_get_boundaries(core, &min_rate, &max_rate);
1355
1356 /* find the closest rate and parent clk/rate */
1357 if (core->ops->determine_rate) {
1358 struct clk_rate_request req;
1359
1360 req.rate = rate;
1361 req.min_rate = min_rate;
1362 req.max_rate = max_rate;
1363 if (parent) {
1364 req.best_parent_hw = parent->hw;
1365 req.best_parent_rate = parent->rate;
1366 } else {
1367 req.best_parent_hw = NULL;
1368 req.best_parent_rate = 0;
1369 }
1370
1371 ret = core->ops->determine_rate(core->hw, &req);
1372 if (ret < 0)
1373 return NULL;
1374
1375 best_parent_rate = req.best_parent_rate;
1376 new_rate = req.rate;
1377 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1378 } else if (core->ops->round_rate) {
1379 ret = core->ops->round_rate(core->hw, rate,
1380 &best_parent_rate);
1381 if (ret < 0)
1382 return NULL;
1383
1384 new_rate = ret;
1385 if (new_rate < min_rate || new_rate > max_rate)
1386 return NULL;
1387 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1388 /* pass-through clock without adjustable parent */
1389 core->new_rate = core->rate;
1390 return NULL;
1391 } else {
1392 /* pass-through clock with adjustable parent */
1393 top = clk_calc_new_rates(parent, rate);
1394 new_rate = parent->new_rate;
1395 goto out;
1396 }
1397
1398 /* some clocks must be gated to change parent */
1399 if (parent != old_parent &&
1400 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1401 pr_debug("%s: %s not gated but wants to reparent\n",
1402 __func__, core->name);
1403 return NULL;
1404 }
1405
1406 /* try finding the new parent index */
1407 if (parent && core->num_parents > 1) {
1408 p_index = clk_fetch_parent_index(core, parent);
1409 if (p_index < 0) {
1410 pr_debug("%s: clk %s can not be parent of clk %s\n",
1411 __func__, parent->name, core->name);
1412 return NULL;
1413 }
1414 }
1415
1416 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1417 best_parent_rate != parent->rate)
1418 top = clk_calc_new_rates(parent, best_parent_rate);
1419
1420out:
1421 clk_calc_subtree(core, new_rate, parent, p_index);
1422
1423 return top;
1424}
1425
1426/*
1427 * Notify about rate changes in a subtree. Always walk down the whole tree
1428 * so that in case of an error we can walk down the whole tree again and
1429 * abort the change.
1430 */
1431static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1432 unsigned long event)
1433{
1434 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1435 int ret = NOTIFY_DONE;
1436
1437 if (core->rate == core->new_rate)
1438 return NULL;
1439
1440 if (core->notifier_count) {
1441 ret = __clk_notify(core, event, core->rate, core->new_rate);
1442 if (ret & NOTIFY_STOP_MASK)
1443 fail_clk = core;
1444 }
1445
1446 hlist_for_each_entry(child, &core->children, child_node) {
1447 /* Skip children who will be reparented to another clock */
1448 if (child->new_parent && child->new_parent != core)
1449 continue;
1450 tmp_clk = clk_propagate_rate_change(child, event);
1451 if (tmp_clk)
1452 fail_clk = tmp_clk;
1453 }
1454
1455 /* handle the new child who might not be in core->children yet */
1456 if (core->new_child) {
1457 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1458 if (tmp_clk)
1459 fail_clk = tmp_clk;
1460 }
1461
1462 return fail_clk;
1463}
1464
1465/*
1466 * walk down a subtree and set the new rates notifying the rate
1467 * change on the way
1468 */
1469static void clk_change_rate(struct clk_core *core)
1470{
1471 struct clk_core *child;
1472 struct hlist_node *tmp;
1473 unsigned long old_rate;
1474 unsigned long best_parent_rate = 0;
1475 bool skip_set_rate = false;
1476 struct clk_core *old_parent;
1477 struct clk_core *parent = NULL;
1478
1479 old_rate = core->rate;
1480
1481 if (core->new_parent) {
1482 parent = core->new_parent;
1483 best_parent_rate = core->new_parent->rate;
1484 } else if (core->parent) {
1485 parent = core->parent;
1486 best_parent_rate = core->parent->rate;
1487 }
1488
1489 if (core->flags & CLK_SET_RATE_UNGATE) {
1490 unsigned long flags;
1491
1492 clk_core_prepare(core);
1493 flags = clk_enable_lock();
1494 clk_core_enable(core);
1495 clk_enable_unlock(flags);
1496 }
1497
1498 if (core->new_parent && core->new_parent != core->parent) {
1499 old_parent = __clk_set_parent_before(core, core->new_parent);
1500 trace_clk_set_parent(core, core->new_parent);
1501
1502 if (core->ops->set_rate_and_parent) {
1503 skip_set_rate = true;
1504 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1505 best_parent_rate,
1506 core->new_parent_index);
1507 } else if (core->ops->set_parent) {
1508 core->ops->set_parent(core->hw, core->new_parent_index);
1509 }
1510
1511 trace_clk_set_parent_complete(core, core->new_parent);
1512 __clk_set_parent_after(core, core->new_parent, old_parent);
1513 }
1514
1515 if (core->flags & CLK_OPS_PARENT_ENABLE)
1516 clk_core_prepare_enable(parent);
1517
1518 trace_clk_set_rate(core, core->new_rate);
1519
1520 if (!skip_set_rate && core->ops->set_rate)
1521 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1522
1523 trace_clk_set_rate_complete(core, core->new_rate);
1524
1525 core->rate = clk_recalc(core, best_parent_rate);
1526
1527 if (core->flags & CLK_SET_RATE_UNGATE) {
1528 unsigned long flags;
1529
1530 flags = clk_enable_lock();
1531 clk_core_disable(core);
1532 clk_enable_unlock(flags);
1533 clk_core_unprepare(core);
1534 }
1535
1536 if (core->flags & CLK_OPS_PARENT_ENABLE)
1537 clk_core_disable_unprepare(parent);
1538
1539 if (core->notifier_count && old_rate != core->rate)
1540 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1541
1542 if (core->flags & CLK_RECALC_NEW_RATES)
1543 (void)clk_calc_new_rates(core, core->new_rate);
1544
1545 /*
1546 * Use safe iteration, as change_rate can actually swap parents
1547 * for certain clock types.
1548 */
1549 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1550 /* Skip children who will be reparented to another clock */
1551 if (child->new_parent && child->new_parent != core)
1552 continue;
1553 clk_change_rate(child);
1554 }
1555
1556 /* handle the new child who might not be in core->children yet */
1557 if (core->new_child)
1558 clk_change_rate(core->new_child);
1559}
1560
1561static int clk_core_set_rate_nolock(struct clk_core *core,
1562 unsigned long req_rate)
1563{
1564 struct clk_core *top, *fail_clk;
1565 unsigned long rate = req_rate;
1566
1567 if (!core)
1568 return 0;
1569
1570 /* bail early if nothing to do */
1571 if (rate == clk_core_get_rate_nolock(core))
1572 return 0;
1573
1574 if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
1575 return -EBUSY;
1576
1577 /* calculate new rates and get the topmost changed clock */
1578 top = clk_calc_new_rates(core, rate);
1579 if (!top)
1580 return -EINVAL;
1581
1582 /* notify that we are about to change rates */
1583 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1584 if (fail_clk) {
1585 pr_debug("%s: failed to set %s rate\n", __func__,
1586 fail_clk->name);
1587 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1588 return -EBUSY;
1589 }
1590
1591 /* change the rates */
1592 clk_change_rate(top);
1593
1594 core->req_rate = req_rate;
1595
1596 return 0;
1597}
1598
1599/**
1600 * clk_set_rate - specify a new rate for clk
1601 * @clk: the clk whose rate is being changed
1602 * @rate: the new rate for clk
1603 *
1604 * In the simplest case clk_set_rate will only adjust the rate of clk.
1605 *
1606 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1607 * propagate up to clk's parent; whether or not this happens depends on the
1608 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1609 * after calling .round_rate then upstream parent propagation is ignored. If
1610 * *parent_rate comes back with a new rate for clk's parent then we propagate
1611 * up to clk's parent and set its rate. Upward propagation will continue
1612 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1613 * .round_rate stops requesting changes to clk's parent_rate.
1614 *
1615 * Rate changes are accomplished via tree traversal that also recalculates the
1616 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1617 *
1618 * Returns 0 on success, -EERROR otherwise.
1619 */
1620int clk_set_rate(struct clk *clk, unsigned long rate)
1621{
1622 int ret;
1623
1624 if (!clk)
1625 return 0;
1626
1627 /* prevent racing with updates to the clock topology */
1628 clk_prepare_lock();
1629
1630 ret = clk_core_set_rate_nolock(clk->core, rate);
1631
1632 clk_prepare_unlock();
1633
1634 return ret;
1635}
1636EXPORT_SYMBOL_GPL(clk_set_rate);
1637
1638/**
1639 * clk_set_rate_range - set a rate range for a clock source
1640 * @clk: clock source
1641 * @min: desired minimum clock rate in Hz, inclusive
1642 * @max: desired maximum clock rate in Hz, inclusive
1643 *
1644 * Returns success (0) or negative errno.
1645 */
1646int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1647{
1648 int ret = 0;
1649
1650 if (!clk)
1651 return 0;
1652
1653 if (min > max) {
1654 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1655 __func__, clk->core->name, clk->dev_id, clk->con_id,
1656 min, max);
1657 return -EINVAL;
1658 }
1659
1660 clk_prepare_lock();
1661
1662 if (min != clk->min_rate || max != clk->max_rate) {
1663 clk->min_rate = min;
1664 clk->max_rate = max;
1665 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1666 }
1667
1668 clk_prepare_unlock();
1669
1670 return ret;
1671}
1672EXPORT_SYMBOL_GPL(clk_set_rate_range);
1673
1674/**
1675 * clk_set_min_rate - set a minimum clock rate for a clock source
1676 * @clk: clock source
1677 * @rate: desired minimum clock rate in Hz, inclusive
1678 *
1679 * Returns success (0) or negative errno.
1680 */
1681int clk_set_min_rate(struct clk *clk, unsigned long rate)
1682{
1683 if (!clk)
1684 return 0;
1685
1686 return clk_set_rate_range(clk, rate, clk->max_rate);
1687}
1688EXPORT_SYMBOL_GPL(clk_set_min_rate);
1689
1690/**
1691 * clk_set_max_rate - set a maximum clock rate for a clock source
1692 * @clk: clock source
1693 * @rate: desired maximum clock rate in Hz, inclusive
1694 *
1695 * Returns success (0) or negative errno.
1696 */
1697int clk_set_max_rate(struct clk *clk, unsigned long rate)
1698{
1699 if (!clk)
1700 return 0;
1701
1702 return clk_set_rate_range(clk, clk->min_rate, rate);
1703}
1704EXPORT_SYMBOL_GPL(clk_set_max_rate);
1705
1706/**
1707 * clk_get_parent - return the parent of a clk
1708 * @clk: the clk whose parent gets returned
1709 *
1710 * Simply returns clk->parent. Returns NULL if clk is NULL.
1711 */
1712struct clk *clk_get_parent(struct clk *clk)
1713{
1714 struct clk *parent;
1715
1716 if (!clk)
1717 return NULL;
1718
1719 clk_prepare_lock();
1720 /* TODO: Create a per-user clk and change callers to call clk_put */
1721 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
1722 clk_prepare_unlock();
1723
1724 return parent;
1725}
1726EXPORT_SYMBOL_GPL(clk_get_parent);
1727
1728static struct clk_core *__clk_init_parent(struct clk_core *core)
1729{
1730 u8 index = 0;
1731
1732 if (core->num_parents > 1 && core->ops->get_parent)
1733 index = core->ops->get_parent(core->hw);
1734
1735 return clk_core_get_parent_by_index(core, index);
1736}
1737
1738static void clk_core_reparent(struct clk_core *core,
1739 struct clk_core *new_parent)
1740{
1741 clk_reparent(core, new_parent);
1742 __clk_recalc_accuracies(core);
1743 __clk_recalc_rates(core, POST_RATE_CHANGE);
1744}
1745
1746void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
1747{
1748 if (!hw)
1749 return;
1750
1751 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
1752}
1753
1754/**
1755 * clk_has_parent - check if a clock is a possible parent for another
1756 * @clk: clock source
1757 * @parent: parent clock source
1758 *
1759 * This function can be used in drivers that need to check that a clock can be
1760 * the parent of another without actually changing the parent.
1761 *
1762 * Returns true if @parent is a possible parent for @clk, false otherwise.
1763 */
1764bool clk_has_parent(struct clk *clk, struct clk *parent)
1765{
1766 struct clk_core *core, *parent_core;
1767 unsigned int i;
1768
1769 /* NULL clocks should be nops, so return success if either is NULL. */
1770 if (!clk || !parent)
1771 return true;
1772
1773 core = clk->core;
1774 parent_core = parent->core;
1775
1776 /* Optimize for the case where the parent is already the parent. */
1777 if (core->parent == parent_core)
1778 return true;
1779
1780 for (i = 0; i < core->num_parents; i++)
1781 if (strcmp(core->parent_names[i], parent_core->name) == 0)
1782 return true;
1783
1784 return false;
1785}
1786EXPORT_SYMBOL_GPL(clk_has_parent);
1787
1788static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
1789{
1790 int ret = 0;
1791 int p_index = 0;
1792 unsigned long p_rate = 0;
1793
1794 if (!core)
1795 return 0;
1796
1797 /* prevent racing with updates to the clock topology */
1798 clk_prepare_lock();
1799
1800 if (core->parent == parent)
1801 goto out;
1802
1803 /* verify ops for for multi-parent clks */
1804 if ((core->num_parents > 1) && (!core->ops->set_parent)) {
1805 ret = -ENOSYS;
1806 goto out;
1807 }
1808
1809 /* check that we are allowed to re-parent if the clock is in use */
1810 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1811 ret = -EBUSY;
1812 goto out;
1813 }
1814
1815 /* try finding the new parent index */
1816 if (parent) {
1817 p_index = clk_fetch_parent_index(core, parent);
1818 if (p_index < 0) {
1819 pr_debug("%s: clk %s can not be parent of clk %s\n",
1820 __func__, parent->name, core->name);
1821 ret = p_index;
1822 goto out;
1823 }
1824 p_rate = parent->rate;
1825 }
1826
1827 /* propagate PRE_RATE_CHANGE notifications */
1828 ret = __clk_speculate_rates(core, p_rate);
1829
1830 /* abort if a driver objects */
1831 if (ret & NOTIFY_STOP_MASK)
1832 goto out;
1833
1834 /* do the re-parent */
1835 ret = __clk_set_parent(core, parent, p_index);
1836
1837 /* propagate rate an accuracy recalculation accordingly */
1838 if (ret) {
1839 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
1840 } else {
1841 __clk_recalc_rates(core, POST_RATE_CHANGE);
1842 __clk_recalc_accuracies(core);
1843 }
1844
1845out:
1846 clk_prepare_unlock();
1847
1848 return ret;
1849}
1850
1851/**
1852 * clk_set_parent - switch the parent of a mux clk
1853 * @clk: the mux clk whose input we are switching
1854 * @parent: the new input to clk
1855 *
1856 * Re-parent clk to use parent as its new input source. If clk is in
1857 * prepared state, the clk will get enabled for the duration of this call. If
1858 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1859 * that, the reparenting is glitchy in hardware, etc), use the
1860 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1861 *
1862 * After successfully changing clk's parent clk_set_parent will update the
1863 * clk topology, sysfs topology and propagate rate recalculation via
1864 * __clk_recalc_rates.
1865 *
1866 * Returns 0 on success, -EERROR otherwise.
1867 */
1868int clk_set_parent(struct clk *clk, struct clk *parent)
1869{
1870 if (!clk)
1871 return 0;
1872
1873 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
1874}
1875EXPORT_SYMBOL_GPL(clk_set_parent);
1876
1877/**
1878 * clk_set_phase - adjust the phase shift of a clock signal
1879 * @clk: clock signal source
1880 * @degrees: number of degrees the signal is shifted
1881 *
1882 * Shifts the phase of a clock signal by the specified
1883 * degrees. Returns 0 on success, -EERROR otherwise.
1884 *
1885 * This function makes no distinction about the input or reference
1886 * signal that we adjust the clock signal phase against. For example
1887 * phase locked-loop clock signal generators we may shift phase with
1888 * respect to feedback clock signal input, but for other cases the
1889 * clock phase may be shifted with respect to some other, unspecified
1890 * signal.
1891 *
1892 * Additionally the concept of phase shift does not propagate through
1893 * the clock tree hierarchy, which sets it apart from clock rates and
1894 * clock accuracy. A parent clock phase attribute does not have an
1895 * impact on the phase attribute of a child clock.
1896 */
1897int clk_set_phase(struct clk *clk, int degrees)
1898{
1899 int ret = -EINVAL;
1900
1901 if (!clk)
1902 return 0;
1903
1904 /* sanity check degrees */
1905 degrees %= 360;
1906 if (degrees < 0)
1907 degrees += 360;
1908
1909 clk_prepare_lock();
1910
1911 trace_clk_set_phase(clk->core, degrees);
1912
1913 if (clk->core->ops->set_phase)
1914 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
1915
1916 trace_clk_set_phase_complete(clk->core, degrees);
1917
1918 if (!ret)
1919 clk->core->phase = degrees;
1920
1921 clk_prepare_unlock();
1922
1923 return ret;
1924}
1925EXPORT_SYMBOL_GPL(clk_set_phase);
1926
1927static int clk_core_get_phase(struct clk_core *core)
1928{
1929 int ret;
1930
1931 clk_prepare_lock();
1932 ret = core->phase;
1933 clk_prepare_unlock();
1934
1935 return ret;
1936}
1937
1938/**
1939 * clk_get_phase - return the phase shift of a clock signal
1940 * @clk: clock signal source
1941 *
1942 * Returns the phase shift of a clock node in degrees, otherwise returns
1943 * -EERROR.
1944 */
1945int clk_get_phase(struct clk *clk)
1946{
1947 if (!clk)
1948 return 0;
1949
1950 return clk_core_get_phase(clk->core);
1951}
1952EXPORT_SYMBOL_GPL(clk_get_phase);
1953
1954/**
1955 * clk_is_match - check if two clk's point to the same hardware clock
1956 * @p: clk compared against q
1957 * @q: clk compared against p
1958 *
1959 * Returns true if the two struct clk pointers both point to the same hardware
1960 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1961 * share the same struct clk_core object.
1962 *
1963 * Returns false otherwise. Note that two NULL clks are treated as matching.
1964 */
1965bool clk_is_match(const struct clk *p, const struct clk *q)
1966{
1967 /* trivial case: identical struct clk's or both NULL */
1968 if (p == q)
1969 return true;
1970
1971 /* true if clk->core pointers match. Avoid dereferencing garbage */
1972 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
1973 if (p->core == q->core)
1974 return true;
1975
1976 return false;
1977}
1978EXPORT_SYMBOL_GPL(clk_is_match);
1979
1980/*** debugfs support ***/
1981
1982#ifdef CONFIG_DEBUG_FS
1983#include <linux/debugfs.h>
1984
1985static struct dentry *rootdir;
1986static int inited = 0;
1987static DEFINE_MUTEX(clk_debug_lock);
1988static HLIST_HEAD(clk_debug_list);
1989
1990static struct hlist_head *all_lists[] = {
1991 &clk_root_list,
1992 &clk_orphan_list,
1993 NULL,
1994};
1995
1996static struct hlist_head *orphan_list[] = {
1997 &clk_orphan_list,
1998 NULL,
1999};
2000
2001static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
2002 int level)
2003{
2004 if (!c)
2005 return;
2006
2007 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
2008 level * 3 + 1, "",
2009 30 - level * 3, c->name,
2010 c->enable_count, c->prepare_count, clk_core_get_rate(c),
2011 clk_core_get_accuracy(c), clk_core_get_phase(c));
2012}
2013
2014static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
2015 int level)
2016{
2017 struct clk_core *child;
2018
2019 if (!c)
2020 return;
2021
2022 clk_summary_show_one(s, c, level);
2023
2024 hlist_for_each_entry(child, &c->children, child_node)
2025 clk_summary_show_subtree(s, child, level + 1);
2026}
2027
2028static int clk_summary_show(struct seq_file *s, void *data)
2029{
2030 struct clk_core *c;
2031 struct hlist_head **lists = (struct hlist_head **)s->private;
2032
2033 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
2034 seq_puts(s, "----------------------------------------------------------------------------------------\n");
2035
2036 clk_prepare_lock();
2037
2038 for (; *lists; lists++)
2039 hlist_for_each_entry(c, *lists, child_node)
2040 clk_summary_show_subtree(s, c, 0);
2041
2042 clk_prepare_unlock();
2043
2044 return 0;
2045}
2046
2047
2048static int clk_summary_open(struct inode *inode, struct file *file)
2049{
2050 return single_open(file, clk_summary_show, inode->i_private);
2051}
2052
2053static const struct file_operations clk_summary_fops = {
2054 .open = clk_summary_open,
2055 .read = seq_read,
2056 .llseek = seq_lseek,
2057 .release = single_release,
2058};
2059
2060static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
2061{
2062 if (!c)
2063 return;
2064
2065 /* This should be JSON format, i.e. elements separated with a comma */
2066 seq_printf(s, "\"%s\": { ", c->name);
2067 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2068 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2069 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2070 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2071 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
2072}
2073
2074static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2075{
2076 struct clk_core *child;
2077
2078 if (!c)
2079 return;
2080
2081 clk_dump_one(s, c, level);
2082
2083 hlist_for_each_entry(child, &c->children, child_node) {
2084 seq_printf(s, ",");
2085 clk_dump_subtree(s, child, level + 1);
2086 }
2087
2088 seq_printf(s, "}");
2089}
2090
2091static int clk_dump(struct seq_file *s, void *data)
2092{
2093 struct clk_core *c;
2094 bool first_node = true;
2095 struct hlist_head **lists = (struct hlist_head **)s->private;
2096
2097 seq_printf(s, "{");
2098
2099 clk_prepare_lock();
2100
2101 for (; *lists; lists++) {
2102 hlist_for_each_entry(c, *lists, child_node) {
2103 if (!first_node)
2104 seq_puts(s, ",");
2105 first_node = false;
2106 clk_dump_subtree(s, c, 0);
2107 }
2108 }
2109
2110 clk_prepare_unlock();
2111
2112 seq_puts(s, "}\n");
2113 return 0;
2114}
2115
2116
2117static int clk_dump_open(struct inode *inode, struct file *file)
2118{
2119 return single_open(file, clk_dump, inode->i_private);
2120}
2121
2122static const struct file_operations clk_dump_fops = {
2123 .open = clk_dump_open,
2124 .read = seq_read,
2125 .llseek = seq_lseek,
2126 .release = single_release,
2127};
2128
2129static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2130{
2131 struct dentry *d;
2132 int ret = -ENOMEM;
2133
2134 if (!core || !pdentry) {
2135 ret = -EINVAL;
2136 goto out;
2137 }
2138
2139 d = debugfs_create_dir(core->name, pdentry);
2140 if (!d)
2141 goto out;
2142
2143 core->dentry = d;
2144
2145 d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
2146 (u32 *)&core->rate);
2147 if (!d)
2148 goto err_out;
2149
2150 d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
2151 (u32 *)&core->accuracy);
2152 if (!d)
2153 goto err_out;
2154
2155 d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
2156 (u32 *)&core->phase);
2157 if (!d)
2158 goto err_out;
2159
2160 d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
2161 (u32 *)&core->flags);
2162 if (!d)
2163 goto err_out;
2164
2165 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
2166 (u32 *)&core->prepare_count);
2167 if (!d)
2168 goto err_out;
2169
2170 d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
2171 (u32 *)&core->enable_count);
2172 if (!d)
2173 goto err_out;
2174
2175 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
2176 (u32 *)&core->notifier_count);
2177 if (!d)
2178 goto err_out;
2179
2180 if (core->ops->debug_init) {
2181 ret = core->ops->debug_init(core->hw, core->dentry);
2182 if (ret)
2183 goto err_out;
2184 }
2185
2186 ret = 0;
2187 goto out;
2188
2189err_out:
2190 debugfs_remove_recursive(core->dentry);
2191 core->dentry = NULL;
2192out:
2193 return ret;
2194}
2195
2196/**
2197 * clk_debug_register - add a clk node to the debugfs clk directory
2198 * @core: the clk being added to the debugfs clk directory
2199 *
2200 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2201 * initialized. Otherwise it bails out early since the debugfs clk directory
2202 * will be created lazily by clk_debug_init as part of a late_initcall.
2203 */
2204static int clk_debug_register(struct clk_core *core)
2205{
2206 int ret = 0;
2207
2208 mutex_lock(&clk_debug_lock);
2209 hlist_add_head(&core->debug_node, &clk_debug_list);
2210
2211 if (!inited)
2212 goto unlock;
2213
2214 ret = clk_debug_create_one(core, rootdir);
2215unlock:
2216 mutex_unlock(&clk_debug_lock);
2217
2218 return ret;
2219}
2220
2221 /**
2222 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2223 * @core: the clk being removed from the debugfs clk directory
2224 *
2225 * Dynamically removes a clk and all its child nodes from the
2226 * debugfs clk directory if clk->dentry points to debugfs created by
2227 * clk_debug_register in __clk_core_init.
2228 */
2229static void clk_debug_unregister(struct clk_core *core)
2230{
2231 mutex_lock(&clk_debug_lock);
2232 hlist_del_init(&core->debug_node);
2233 debugfs_remove_recursive(core->dentry);
2234 core->dentry = NULL;
2235 mutex_unlock(&clk_debug_lock);
2236}
2237
2238struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
2239 void *data, const struct file_operations *fops)
2240{
2241 struct dentry *d = NULL;
2242
2243 if (hw->core->dentry)
2244 d = debugfs_create_file(name, mode, hw->core->dentry, data,
2245 fops);
2246
2247 return d;
2248}
2249EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
2250
2251/**
2252 * clk_debug_init - lazily populate the debugfs clk directory
2253 *
2254 * clks are often initialized very early during boot before memory can be
2255 * dynamically allocated and well before debugfs is setup. This function
2256 * populates the debugfs clk directory once at boot-time when we know that
2257 * debugfs is setup. It should only be called once at boot-time, all other clks
2258 * added dynamically will be done so with clk_debug_register.
2259 */
2260static int __init clk_debug_init(void)
2261{
2262 struct clk_core *core;
2263 struct dentry *d;
2264
2265 rootdir = debugfs_create_dir("clk", NULL);
2266
2267 if (!rootdir)
2268 return -ENOMEM;
2269
2270 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
2271 &clk_summary_fops);
2272 if (!d)
2273 return -ENOMEM;
2274
2275 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
2276 &clk_dump_fops);
2277 if (!d)
2278 return -ENOMEM;
2279
2280 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
2281 &orphan_list, &clk_summary_fops);
2282 if (!d)
2283 return -ENOMEM;
2284
2285 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
2286 &orphan_list, &clk_dump_fops);
2287 if (!d)
2288 return -ENOMEM;
2289
2290 mutex_lock(&clk_debug_lock);
2291 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2292 clk_debug_create_one(core, rootdir);
2293
2294 inited = 1;
2295 mutex_unlock(&clk_debug_lock);
2296
2297 return 0;
2298}
2299late_initcall(clk_debug_init);
2300#else
2301static inline int clk_debug_register(struct clk_core *core) { return 0; }
2302static inline void clk_debug_reparent(struct clk_core *core,
2303 struct clk_core *new_parent)
2304{
2305}
2306static inline void clk_debug_unregister(struct clk_core *core)
2307{
2308}
2309#endif
2310
2311/**
2312 * __clk_core_init - initialize the data structures in a struct clk_core
2313 * @core: clk_core being initialized
2314 *
2315 * Initializes the lists in struct clk_core, queries the hardware for the
2316 * parent and rate and sets them both.
2317 */
2318static int __clk_core_init(struct clk_core *core)
2319{
2320 int i, ret = 0;
2321 struct clk_core *orphan;
2322 struct hlist_node *tmp2;
2323 unsigned long rate;
2324
2325 if (!core)
2326 return -EINVAL;
2327
2328 clk_prepare_lock();
2329
2330 /* check to see if a clock with this name is already registered */
2331 if (clk_core_lookup(core->name)) {
2332 pr_debug("%s: clk %s already initialized\n",
2333 __func__, core->name);
2334 ret = -EEXIST;
2335 goto out;
2336 }
2337
2338 /* check that clk_ops are sane. See Documentation/clk.txt */
2339 if (core->ops->set_rate &&
2340 !((core->ops->round_rate || core->ops->determine_rate) &&
2341 core->ops->recalc_rate)) {
2342 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2343 __func__, core->name);
2344 ret = -EINVAL;
2345 goto out;
2346 }
2347
2348 if (core->ops->set_parent && !core->ops->get_parent) {
2349 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2350 __func__, core->name);
2351 ret = -EINVAL;
2352 goto out;
2353 }
2354
2355 if (core->num_parents > 1 && !core->ops->get_parent) {
2356 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2357 __func__, core->name);
2358 ret = -EINVAL;
2359 goto out;
2360 }
2361
2362 if (core->ops->set_rate_and_parent &&
2363 !(core->ops->set_parent && core->ops->set_rate)) {
2364 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2365 __func__, core->name);
2366 ret = -EINVAL;
2367 goto out;
2368 }
2369
2370 /* throw a WARN if any entries in parent_names are NULL */
2371 for (i = 0; i < core->num_parents; i++)
2372 WARN(!core->parent_names[i],
2373 "%s: invalid NULL in %s's .parent_names\n",
2374 __func__, core->name);
2375
2376 core->parent = __clk_init_parent(core);
2377
2378 /*
2379 * Populate core->parent if parent has already been clk_core_init'd. If
2380 * parent has not yet been clk_core_init'd then place clk in the orphan
2381 * list. If clk doesn't have any parents then place it in the root
2382 * clk list.
2383 *
2384 * Every time a new clk is clk_init'd then we walk the list of orphan
2385 * clocks and re-parent any that are children of the clock currently
2386 * being clk_init'd.
2387 */
2388 if (core->parent) {
2389 hlist_add_head(&core->child_node,
2390 &core->parent->children);
2391 core->orphan = core->parent->orphan;
2392 } else if (!core->num_parents) {
2393 hlist_add_head(&core->child_node, &clk_root_list);
2394 core->orphan = false;
2395 } else {
2396 hlist_add_head(&core->child_node, &clk_orphan_list);
2397 core->orphan = true;
2398 }
2399
2400 /*
2401 * Set clk's accuracy. The preferred method is to use
2402 * .recalc_accuracy. For simple clocks and lazy developers the default
2403 * fallback is to use the parent's accuracy. If a clock doesn't have a
2404 * parent (or is orphaned) then accuracy is set to zero (perfect
2405 * clock).
2406 */
2407 if (core->ops->recalc_accuracy)
2408 core->accuracy = core->ops->recalc_accuracy(core->hw,
2409 __clk_get_accuracy(core->parent));
2410 else if (core->parent)
2411 core->accuracy = core->parent->accuracy;
2412 else
2413 core->accuracy = 0;
2414
2415 /*
2416 * Set clk's phase.
2417 * Since a phase is by definition relative to its parent, just
2418 * query the current clock phase, or just assume it's in phase.
2419 */
2420 if (core->ops->get_phase)
2421 core->phase = core->ops->get_phase(core->hw);
2422 else
2423 core->phase = 0;
2424
2425 /*
2426 * Set clk's rate. The preferred method is to use .recalc_rate. For
2427 * simple clocks and lazy developers the default fallback is to use the
2428 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2429 * then rate is set to zero.
2430 */
2431 if (core->ops->recalc_rate)
2432 rate = core->ops->recalc_rate(core->hw,
2433 clk_core_get_rate_nolock(core->parent));
2434 else if (core->parent)
2435 rate = core->parent->rate;
2436 else
2437 rate = 0;
2438 core->rate = core->req_rate = rate;
2439
2440 /*
2441 * walk the list of orphan clocks and reparent any that newly finds a
2442 * parent.
2443 */
2444 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
2445 struct clk_core *parent = __clk_init_parent(orphan);
2446
2447 /*
2448 * we could call __clk_set_parent, but that would result in a
2449 * redundant call to the .set_rate op, if it exists
2450 */
2451 if (parent) {
2452 __clk_set_parent_before(orphan, parent);
2453 __clk_set_parent_after(orphan, parent, NULL);
2454 __clk_recalc_accuracies(orphan);
2455 __clk_recalc_rates(orphan, 0);
2456 }
2457 }
2458
2459 /*
2460 * optional platform-specific magic
2461 *
2462 * The .init callback is not used by any of the basic clock types, but
2463 * exists for weird hardware that must perform initialization magic.
2464 * Please consider other ways of solving initialization problems before
2465 * using this callback, as its use is discouraged.
2466 */
2467 if (core->ops->init)
2468 core->ops->init(core->hw);
2469
2470 if (core->flags & CLK_IS_CRITICAL) {
2471 unsigned long flags;
2472
2473 clk_core_prepare(core);
2474
2475 flags = clk_enable_lock();
2476 clk_core_enable(core);
2477 clk_enable_unlock(flags);
2478 }
2479
2480 kref_init(&core->ref);
2481out:
2482 clk_prepare_unlock();
2483
2484 if (!ret)
2485 clk_debug_register(core);
2486
2487 return ret;
2488}
2489
2490struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2491 const char *con_id)
2492{
2493 struct clk *clk;
2494
2495 /* This is to allow this function to be chained to others */
2496 if (IS_ERR_OR_NULL(hw))
2497 return ERR_CAST(hw);
2498
2499 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2500 if (!clk)
2501 return ERR_PTR(-ENOMEM);
2502
2503 clk->core = hw->core;
2504 clk->dev_id = dev_id;
2505 clk->con_id = con_id;
2506 clk->max_rate = ULONG_MAX;
2507
2508 clk_prepare_lock();
2509 hlist_add_head(&clk->clks_node, &hw->core->clks);
2510 clk_prepare_unlock();
2511
2512 return clk;
2513}
2514
2515void __clk_free_clk(struct clk *clk)
2516{
2517 clk_prepare_lock();
2518 hlist_del(&clk->clks_node);
2519 clk_prepare_unlock();
2520
2521 kfree(clk);
2522}
2523
2524/**
2525 * clk_register - allocate a new clock, register it and return an opaque cookie
2526 * @dev: device that is registering this clock
2527 * @hw: link to hardware-specific clock data
2528 *
2529 * clk_register is the primary interface for populating the clock tree with new
2530 * clock nodes. It returns a pointer to the newly allocated struct clk which
2531 * cannot be dereferenced by driver code but may be used in conjunction with the
2532 * rest of the clock API. In the event of an error clk_register will return an
2533 * error code; drivers must test for an error code after calling clk_register.
2534 */
2535struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2536{
2537 int i, ret;
2538 struct clk_core *core;
2539
2540 core = kzalloc(sizeof(*core), GFP_KERNEL);
2541 if (!core) {
2542 ret = -ENOMEM;
2543 goto fail_out;
2544 }
2545
2546 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
2547 if (!core->name) {
2548 ret = -ENOMEM;
2549 goto fail_name;
2550 }
2551 core->ops = hw->init->ops;
2552 if (dev && dev->driver)
2553 core->owner = dev->driver->owner;
2554 core->hw = hw;
2555 core->flags = hw->init->flags;
2556 core->num_parents = hw->init->num_parents;
2557 core->min_rate = 0;
2558 core->max_rate = ULONG_MAX;
2559 hw->core = core;
2560
2561 /* allocate local copy in case parent_names is __initdata */
2562 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
2563 GFP_KERNEL);
2564
2565 if (!core->parent_names) {
2566 ret = -ENOMEM;
2567 goto fail_parent_names;
2568 }
2569
2570
2571 /* copy each string name in case parent_names is __initdata */
2572 for (i = 0; i < core->num_parents; i++) {
2573 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
2574 GFP_KERNEL);
2575 if (!core->parent_names[i]) {
2576 ret = -ENOMEM;
2577 goto fail_parent_names_copy;
2578 }
2579 }
2580
2581 /* avoid unnecessary string look-ups of clk_core's possible parents. */
2582 core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
2583 GFP_KERNEL);
2584 if (!core->parents) {
2585 ret = -ENOMEM;
2586 goto fail_parents;
2587 };
2588
2589 INIT_HLIST_HEAD(&core->clks);
2590
2591 hw->clk = __clk_create_clk(hw, NULL, NULL);
2592 if (IS_ERR(hw->clk)) {
2593 ret = PTR_ERR(hw->clk);
2594 goto fail_parents;
2595 }
2596
2597 ret = __clk_core_init(core);
2598 if (!ret)
2599 return hw->clk;
2600
2601 __clk_free_clk(hw->clk);
2602 hw->clk = NULL;
2603
2604fail_parents:
2605 kfree(core->parents);
2606fail_parent_names_copy:
2607 while (--i >= 0)
2608 kfree_const(core->parent_names[i]);
2609 kfree(core->parent_names);
2610fail_parent_names:
2611 kfree_const(core->name);
2612fail_name:
2613 kfree(core);
2614fail_out:
2615 return ERR_PTR(ret);
2616}
2617EXPORT_SYMBOL_GPL(clk_register);
2618
2619/**
2620 * clk_hw_register - register a clk_hw and return an error code
2621 * @dev: device that is registering this clock
2622 * @hw: link to hardware-specific clock data
2623 *
2624 * clk_hw_register is the primary interface for populating the clock tree with
2625 * new clock nodes. It returns an integer equal to zero indicating success or
2626 * less than zero indicating failure. Drivers must test for an error code after
2627 * calling clk_hw_register().
2628 */
2629int clk_hw_register(struct device *dev, struct clk_hw *hw)
2630{
2631 return PTR_ERR_OR_ZERO(clk_register(dev, hw));
2632}
2633EXPORT_SYMBOL_GPL(clk_hw_register);
2634
2635/* Free memory allocated for a clock. */
2636static void __clk_release(struct kref *ref)
2637{
2638 struct clk_core *core = container_of(ref, struct clk_core, ref);
2639 int i = core->num_parents;
2640
2641 lockdep_assert_held(&prepare_lock);
2642
2643 kfree(core->parents);
2644 while (--i >= 0)
2645 kfree_const(core->parent_names[i]);
2646
2647 kfree(core->parent_names);
2648 kfree_const(core->name);
2649 kfree(core);
2650}
2651
2652/*
2653 * Empty clk_ops for unregistered clocks. These are used temporarily
2654 * after clk_unregister() was called on a clock and until last clock
2655 * consumer calls clk_put() and the struct clk object is freed.
2656 */
2657static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2658{
2659 return -ENXIO;
2660}
2661
2662static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2663{
2664 WARN_ON_ONCE(1);
2665}
2666
2667static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2668 unsigned long parent_rate)
2669{
2670 return -ENXIO;
2671}
2672
2673static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2674{
2675 return -ENXIO;
2676}
2677
2678static const struct clk_ops clk_nodrv_ops = {
2679 .enable = clk_nodrv_prepare_enable,
2680 .disable = clk_nodrv_disable_unprepare,
2681 .prepare = clk_nodrv_prepare_enable,
2682 .unprepare = clk_nodrv_disable_unprepare,
2683 .set_rate = clk_nodrv_set_rate,
2684 .set_parent = clk_nodrv_set_parent,
2685};
2686
2687/**
2688 * clk_unregister - unregister a currently registered clock
2689 * @clk: clock to unregister
2690 */
2691void clk_unregister(struct clk *clk)
2692{
2693 unsigned long flags;
2694
2695 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2696 return;
2697
2698 clk_debug_unregister(clk->core);
2699
2700 clk_prepare_lock();
2701
2702 if (clk->core->ops == &clk_nodrv_ops) {
2703 pr_err("%s: unregistered clock: %s\n", __func__,
2704 clk->core->name);
2705 goto unlock;
2706 }
2707 /*
2708 * Assign empty clock ops for consumers that might still hold
2709 * a reference to this clock.
2710 */
2711 flags = clk_enable_lock();
2712 clk->core->ops = &clk_nodrv_ops;
2713 clk_enable_unlock(flags);
2714
2715 if (!hlist_empty(&clk->core->children)) {
2716 struct clk_core *child;
2717 struct hlist_node *t;
2718
2719 /* Reparent all children to the orphan list. */
2720 hlist_for_each_entry_safe(child, t, &clk->core->children,
2721 child_node)
2722 clk_core_set_parent(child, NULL);
2723 }
2724
2725 hlist_del_init(&clk->core->child_node);
2726
2727 if (clk->core->prepare_count)
2728 pr_warn("%s: unregistering prepared clock: %s\n",
2729 __func__, clk->core->name);
2730 kref_put(&clk->core->ref, __clk_release);
2731unlock:
2732 clk_prepare_unlock();
2733}
2734EXPORT_SYMBOL_GPL(clk_unregister);
2735
2736/**
2737 * clk_hw_unregister - unregister a currently registered clk_hw
2738 * @hw: hardware-specific clock data to unregister
2739 */
2740void clk_hw_unregister(struct clk_hw *hw)
2741{
2742 clk_unregister(hw->clk);
2743}
2744EXPORT_SYMBOL_GPL(clk_hw_unregister);
2745
2746static void devm_clk_release(struct device *dev, void *res)
2747{
2748 clk_unregister(*(struct clk **)res);
2749}
2750
2751static void devm_clk_hw_release(struct device *dev, void *res)
2752{
2753 clk_hw_unregister(*(struct clk_hw **)res);
2754}
2755
2756/**
2757 * devm_clk_register - resource managed clk_register()
2758 * @dev: device that is registering this clock
2759 * @hw: link to hardware-specific clock data
2760 *
2761 * Managed clk_register(). Clocks returned from this function are
2762 * automatically clk_unregister()ed on driver detach. See clk_register() for
2763 * more information.
2764 */
2765struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2766{
2767 struct clk *clk;
2768 struct clk **clkp;
2769
2770 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2771 if (!clkp)
2772 return ERR_PTR(-ENOMEM);
2773
2774 clk = clk_register(dev, hw);
2775 if (!IS_ERR(clk)) {
2776 *clkp = clk;
2777 devres_add(dev, clkp);
2778 } else {
2779 devres_free(clkp);
2780 }
2781
2782 return clk;
2783}
2784EXPORT_SYMBOL_GPL(devm_clk_register);
2785
2786/**
2787 * devm_clk_hw_register - resource managed clk_hw_register()
2788 * @dev: device that is registering this clock
2789 * @hw: link to hardware-specific clock data
2790 *
2791 * Managed clk_hw_register(). Clocks registered by this function are
2792 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
2793 * for more information.
2794 */
2795int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
2796{
2797 struct clk_hw **hwp;
2798 int ret;
2799
2800 hwp = devres_alloc(devm_clk_hw_release, sizeof(*hwp), GFP_KERNEL);
2801 if (!hwp)
2802 return -ENOMEM;
2803
2804 ret = clk_hw_register(dev, hw);
2805 if (!ret) {
2806 *hwp = hw;
2807 devres_add(dev, hwp);
2808 } else {
2809 devres_free(hwp);
2810 }
2811
2812 return ret;
2813}
2814EXPORT_SYMBOL_GPL(devm_clk_hw_register);
2815
2816static int devm_clk_match(struct device *dev, void *res, void *data)
2817{
2818 struct clk *c = res;
2819 if (WARN_ON(!c))
2820 return 0;
2821 return c == data;
2822}
2823
2824static int devm_clk_hw_match(struct device *dev, void *res, void *data)
2825{
2826 struct clk_hw *hw = res;
2827
2828 if (WARN_ON(!hw))
2829 return 0;
2830 return hw == data;
2831}
2832
2833/**
2834 * devm_clk_unregister - resource managed clk_unregister()
2835 * @clk: clock to unregister
2836 *
2837 * Deallocate a clock allocated with devm_clk_register(). Normally
2838 * this function will not need to be called and the resource management
2839 * code will ensure that the resource is freed.
2840 */
2841void devm_clk_unregister(struct device *dev, struct clk *clk)
2842{
2843 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2844}
2845EXPORT_SYMBOL_GPL(devm_clk_unregister);
2846
2847/**
2848 * devm_clk_hw_unregister - resource managed clk_hw_unregister()
2849 * @dev: device that is unregistering the hardware-specific clock data
2850 * @hw: link to hardware-specific clock data
2851 *
2852 * Unregister a clk_hw registered with devm_clk_hw_register(). Normally
2853 * this function will not need to be called and the resource management
2854 * code will ensure that the resource is freed.
2855 */
2856void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw)
2857{
2858 WARN_ON(devres_release(dev, devm_clk_hw_release, devm_clk_hw_match,
2859 hw));
2860}
2861EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
2862
2863/*
2864 * clkdev helpers
2865 */
2866int __clk_get(struct clk *clk)
2867{
2868 struct clk_core *core = !clk ? NULL : clk->core;
2869
2870 if (core) {
2871 if (!try_module_get(core->owner))
2872 return 0;
2873
2874 kref_get(&core->ref);
2875 }
2876 return 1;
2877}
2878
2879void __clk_put(struct clk *clk)
2880{
2881 struct module *owner;
2882
2883 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2884 return;
2885
2886 clk_prepare_lock();
2887
2888 hlist_del(&clk->clks_node);
2889 if (clk->min_rate > clk->core->req_rate ||
2890 clk->max_rate < clk->core->req_rate)
2891 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2892
2893 owner = clk->core->owner;
2894 kref_put(&clk->core->ref, __clk_release);
2895
2896 clk_prepare_unlock();
2897
2898 module_put(owner);
2899
2900 kfree(clk);
2901}
2902
2903/*** clk rate change notifiers ***/
2904
2905/**
2906 * clk_notifier_register - add a clk rate change notifier
2907 * @clk: struct clk * to watch
2908 * @nb: struct notifier_block * with callback info
2909 *
2910 * Request notification when clk's rate changes. This uses an SRCU
2911 * notifier because we want it to block and notifier unregistrations are
2912 * uncommon. The callbacks associated with the notifier must not
2913 * re-enter into the clk framework by calling any top-level clk APIs;
2914 * this will cause a nested prepare_lock mutex.
2915 *
2916 * In all notification cases (pre, post and abort rate change) the original
2917 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
2918 * and the new frequency is passed via struct clk_notifier_data.new_rate.
2919 *
2920 * clk_notifier_register() must be called from non-atomic context.
2921 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2922 * allocation failure; otherwise, passes along the return value of
2923 * srcu_notifier_chain_register().
2924 */
2925int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2926{
2927 struct clk_notifier *cn;
2928 int ret = -ENOMEM;
2929
2930 if (!clk || !nb)
2931 return -EINVAL;
2932
2933 clk_prepare_lock();
2934
2935 /* search the list of notifiers for this clk */
2936 list_for_each_entry(cn, &clk_notifier_list, node)
2937 if (cn->clk == clk)
2938 break;
2939
2940 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2941 if (cn->clk != clk) {
2942 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2943 if (!cn)
2944 goto out;
2945
2946 cn->clk = clk;
2947 srcu_init_notifier_head(&cn->notifier_head);
2948
2949 list_add(&cn->node, &clk_notifier_list);
2950 }
2951
2952 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2953
2954 clk->core->notifier_count++;
2955
2956out:
2957 clk_prepare_unlock();
2958
2959 return ret;
2960}
2961EXPORT_SYMBOL_GPL(clk_notifier_register);
2962
2963/**
2964 * clk_notifier_unregister - remove a clk rate change notifier
2965 * @clk: struct clk *
2966 * @nb: struct notifier_block * with callback info
2967 *
2968 * Request no further notification for changes to 'clk' and frees memory
2969 * allocated in clk_notifier_register.
2970 *
2971 * Returns -EINVAL if called with null arguments; otherwise, passes
2972 * along the return value of srcu_notifier_chain_unregister().
2973 */
2974int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2975{
2976 struct clk_notifier *cn = NULL;
2977 int ret = -EINVAL;
2978
2979 if (!clk || !nb)
2980 return -EINVAL;
2981
2982 clk_prepare_lock();
2983
2984 list_for_each_entry(cn, &clk_notifier_list, node)
2985 if (cn->clk == clk)
2986 break;
2987
2988 if (cn->clk == clk) {
2989 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2990
2991 clk->core->notifier_count--;
2992
2993 /* XXX the notifier code should handle this better */
2994 if (!cn->notifier_head.head) {
2995 srcu_cleanup_notifier_head(&cn->notifier_head);
2996 list_del(&cn->node);
2997 kfree(cn);
2998 }
2999
3000 } else {
3001 ret = -ENOENT;
3002 }
3003
3004 clk_prepare_unlock();
3005
3006 return ret;
3007}
3008EXPORT_SYMBOL_GPL(clk_notifier_unregister);
3009
3010#ifdef CONFIG_OF
3011/**
3012 * struct of_clk_provider - Clock provider registration structure
3013 * @link: Entry in global list of clock providers
3014 * @node: Pointer to device tree node of clock provider
3015 * @get: Get clock callback. Returns NULL or a struct clk for the
3016 * given clock specifier
3017 * @data: context pointer to be passed into @get callback
3018 */
3019struct of_clk_provider {
3020 struct list_head link;
3021
3022 struct device_node *node;
3023 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
3024 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
3025 void *data;
3026};
3027
3028static const struct of_device_id __clk_of_table_sentinel
3029 __used __section(__clk_of_table_end);
3030
3031static LIST_HEAD(of_clk_providers);
3032static DEFINE_MUTEX(of_clk_mutex);
3033
3034struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
3035 void *data)
3036{
3037 return data;
3038}
3039EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
3040
3041struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
3042{
3043 return data;
3044}
3045EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
3046
3047struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
3048{
3049 struct clk_onecell_data *clk_data = data;
3050 unsigned int idx = clkspec->args[0];
3051
3052 if (idx >= clk_data->clk_num) {
3053 pr_err("%s: invalid clock index %u\n", __func__, idx);
3054 return ERR_PTR(-EINVAL);
3055 }
3056
3057 return clk_data->clks[idx];
3058}
3059EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
3060
3061struct clk_hw *
3062of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
3063{
3064 struct clk_hw_onecell_data *hw_data = data;
3065 unsigned int idx = clkspec->args[0];
3066
3067 if (idx >= hw_data->num) {
3068 pr_err("%s: invalid index %u\n", __func__, idx);
3069 return ERR_PTR(-EINVAL);
3070 }
3071
3072 return hw_data->hws[idx];
3073}
3074EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
3075
3076/**
3077 * of_clk_add_provider() - Register a clock provider for a node
3078 * @np: Device node pointer associated with clock provider
3079 * @clk_src_get: callback for decoding clock
3080 * @data: context pointer for @clk_src_get callback.
3081 */
3082int of_clk_add_provider(struct device_node *np,
3083 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
3084 void *data),
3085 void *data)
3086{
3087 struct of_clk_provider *cp;
3088 int ret;
3089
3090 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
3091 if (!cp)
3092 return -ENOMEM;
3093
3094 cp->node = of_node_get(np);
3095 cp->data = data;
3096 cp->get = clk_src_get;
3097
3098 mutex_lock(&of_clk_mutex);
3099 list_add(&cp->link, &of_clk_providers);
3100 mutex_unlock(&of_clk_mutex);
3101 pr_debug("Added clock from %s\n", np->full_name);
3102
3103 ret = of_clk_set_defaults(np, true);
3104 if (ret < 0)
3105 of_clk_del_provider(np);
3106
3107 return ret;
3108}
3109EXPORT_SYMBOL_GPL(of_clk_add_provider);
3110
3111/**
3112 * of_clk_add_hw_provider() - Register a clock provider for a node
3113 * @np: Device node pointer associated with clock provider
3114 * @get: callback for decoding clk_hw
3115 * @data: context pointer for @get callback.
3116 */
3117int of_clk_add_hw_provider(struct device_node *np,
3118 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
3119 void *data),
3120 void *data)
3121{
3122 struct of_clk_provider *cp;
3123 int ret;
3124
3125 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
3126 if (!cp)
3127 return -ENOMEM;
3128
3129 cp->node = of_node_get(np);
3130 cp->data = data;
3131 cp->get_hw = get;
3132
3133 mutex_lock(&of_clk_mutex);
3134 list_add(&cp->link, &of_clk_providers);
3135 mutex_unlock(&of_clk_mutex);
3136 pr_debug("Added clk_hw provider from %s\n", np->full_name);
3137
3138 ret = of_clk_set_defaults(np, true);
3139 if (ret < 0)
3140 of_clk_del_provider(np);
3141
3142 return ret;
3143}
3144EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
3145
3146/**
3147 * of_clk_del_provider() - Remove a previously registered clock provider
3148 * @np: Device node pointer associated with clock provider
3149 */
3150void of_clk_del_provider(struct device_node *np)
3151{
3152 struct of_clk_provider *cp;
3153
3154 mutex_lock(&of_clk_mutex);
3155 list_for_each_entry(cp, &of_clk_providers, link) {
3156 if (cp->node == np) {
3157 list_del(&cp->link);
3158 of_node_put(cp->node);
3159 kfree(cp);
3160 break;
3161 }
3162 }
3163 mutex_unlock(&of_clk_mutex);
3164}
3165EXPORT_SYMBOL_GPL(of_clk_del_provider);
3166
3167static struct clk_hw *
3168__of_clk_get_hw_from_provider(struct of_clk_provider *provider,
3169 struct of_phandle_args *clkspec)
3170{
3171 struct clk *clk;
3172
3173 if (provider->get_hw)
3174 return provider->get_hw(clkspec, provider->data);
3175
3176 clk = provider->get(clkspec, provider->data);
3177 if (IS_ERR(clk))
3178 return ERR_CAST(clk);
3179 return __clk_get_hw(clk);
3180}
3181
3182struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
3183 const char *dev_id, const char *con_id)
3184{
3185 struct of_clk_provider *provider;
3186 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
3187 struct clk_hw *hw;
3188
3189 if (!clkspec)
3190 return ERR_PTR(-EINVAL);
3191
3192 /* Check if we have such a provider in our array */
3193 mutex_lock(&of_clk_mutex);
3194 list_for_each_entry(provider, &of_clk_providers, link) {
3195 if (provider->node == clkspec->np) {
3196 hw = __of_clk_get_hw_from_provider(provider, clkspec);
3197 clk = __clk_create_clk(hw, dev_id, con_id);
3198 }
3199
3200 if (!IS_ERR(clk)) {
3201 if (!__clk_get(clk)) {
3202 __clk_free_clk(clk);
3203 clk = ERR_PTR(-ENOENT);
3204 }
3205
3206 break;
3207 }
3208 }
3209 mutex_unlock(&of_clk_mutex);
3210
3211 return clk;
3212}
3213
3214/**
3215 * of_clk_get_from_provider() - Lookup a clock from a clock provider
3216 * @clkspec: pointer to a clock specifier data structure
3217 *
3218 * This function looks up a struct clk from the registered list of clock
3219 * providers, an input is a clock specifier data structure as returned
3220 * from the of_parse_phandle_with_args() function call.
3221 */
3222struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
3223{
3224 return __of_clk_get_from_provider(clkspec, NULL, __func__);
3225}
3226EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
3227
3228/**
3229 * of_clk_get_parent_count() - Count the number of clocks a device node has
3230 * @np: device node to count
3231 *
3232 * Returns: The number of clocks that are possible parents of this node
3233 */
3234unsigned int of_clk_get_parent_count(struct device_node *np)
3235{
3236 int count;
3237
3238 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
3239 if (count < 0)
3240 return 0;
3241
3242 return count;
3243}
3244EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3245
3246const char *of_clk_get_parent_name(struct device_node *np, int index)
3247{
3248 struct of_phandle_args clkspec;
3249 struct property *prop;
3250 const char *clk_name;
3251 const __be32 *vp;
3252 u32 pv;
3253 int rc;
3254 int count;
3255 struct clk *clk;
3256
3257 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3258 &clkspec);
3259 if (rc)
3260 return NULL;
3261
3262 index = clkspec.args_count ? clkspec.args[0] : 0;
3263 count = 0;
3264
3265 /* if there is an indices property, use it to transfer the index
3266 * specified into an array offset for the clock-output-names property.
3267 */
3268 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3269 if (index == pv) {
3270 index = count;
3271 break;
3272 }
3273 count++;
3274 }
3275 /* We went off the end of 'clock-indices' without finding it */
3276 if (prop && !vp)
3277 return NULL;
3278
3279 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3280 index,
3281 &clk_name) < 0) {
3282 /*
3283 * Best effort to get the name if the clock has been
3284 * registered with the framework. If the clock isn't
3285 * registered, we return the node name as the name of
3286 * the clock as long as #clock-cells = 0.
3287 */
3288 clk = of_clk_get_from_provider(&clkspec);
3289 if (IS_ERR(clk)) {
3290 if (clkspec.args_count == 0)
3291 clk_name = clkspec.np->name;
3292 else
3293 clk_name = NULL;
3294 } else {
3295 clk_name = __clk_get_name(clk);
3296 clk_put(clk);
3297 }
3298 }
3299
3300
3301 of_node_put(clkspec.np);
3302 return clk_name;
3303}
3304EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3305
3306/**
3307 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3308 * number of parents
3309 * @np: Device node pointer associated with clock provider
3310 * @parents: pointer to char array that hold the parents' names
3311 * @size: size of the @parents array
3312 *
3313 * Return: number of parents for the clock node.
3314 */
3315int of_clk_parent_fill(struct device_node *np, const char **parents,
3316 unsigned int size)
3317{
3318 unsigned int i = 0;
3319
3320 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
3321 i++;
3322
3323 return i;
3324}
3325EXPORT_SYMBOL_GPL(of_clk_parent_fill);
3326
3327struct clock_provider {
3328 of_clk_init_cb_t clk_init_cb;
3329 struct device_node *np;
3330 struct list_head node;
3331};
3332
3333/*
3334 * This function looks for a parent clock. If there is one, then it
3335 * checks that the provider for this parent clock was initialized, in
3336 * this case the parent clock will be ready.
3337 */
3338static int parent_ready(struct device_node *np)
3339{
3340 int i = 0;
3341
3342 while (true) {
3343 struct clk *clk = of_clk_get(np, i);
3344
3345 /* this parent is ready we can check the next one */
3346 if (!IS_ERR(clk)) {
3347 clk_put(clk);
3348 i++;
3349 continue;
3350 }
3351
3352 /* at least one parent is not ready, we exit now */
3353 if (PTR_ERR(clk) == -EPROBE_DEFER)
3354 return 0;
3355
3356 /*
3357 * Here we make assumption that the device tree is
3358 * written correctly. So an error means that there is
3359 * no more parent. As we didn't exit yet, then the
3360 * previous parent are ready. If there is no clock
3361 * parent, no need to wait for them, then we can
3362 * consider their absence as being ready
3363 */
3364 return 1;
3365 }
3366}
3367
3368/**
3369 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
3370 * @np: Device node pointer associated with clock provider
3371 * @index: clock index
3372 * @flags: pointer to clk_core->flags
3373 *
3374 * Detects if the clock-critical property exists and, if so, sets the
3375 * corresponding CLK_IS_CRITICAL flag.
3376 *
3377 * Do not use this function. It exists only for legacy Device Tree
3378 * bindings, such as the one-clock-per-node style that are outdated.
3379 * Those bindings typically put all clock data into .dts and the Linux
3380 * driver has no clock data, thus making it impossible to set this flag
3381 * correctly from the driver. Only those drivers may call
3382 * of_clk_detect_critical from their setup functions.
3383 *
3384 * Return: error code or zero on success
3385 */
3386int of_clk_detect_critical(struct device_node *np,
3387 int index, unsigned long *flags)
3388{
3389 struct property *prop;
3390 const __be32 *cur;
3391 uint32_t idx;
3392
3393 if (!np || !flags)
3394 return -EINVAL;
3395
3396 of_property_for_each_u32(np, "clock-critical", prop, cur, idx)
3397 if (index == idx)
3398 *flags |= CLK_IS_CRITICAL;
3399
3400 return 0;
3401}
3402
3403/**
3404 * of_clk_init() - Scan and init clock providers from the DT
3405 * @matches: array of compatible values and init functions for providers.
3406 *
3407 * This function scans the device tree for matching clock providers
3408 * and calls their initialization functions. It also does it by trying
3409 * to follow the dependencies.
3410 */
3411void __init of_clk_init(const struct of_device_id *matches)
3412{
3413 const struct of_device_id *match;
3414 struct device_node *np;
3415 struct clock_provider *clk_provider, *next;
3416 bool is_init_done;
3417 bool force = false;
3418 LIST_HEAD(clk_provider_list);
3419
3420 if (!matches)
3421 matches = &__clk_of_table;
3422
3423 /* First prepare the list of the clocks providers */
3424 for_each_matching_node_and_match(np, matches, &match) {
3425 struct clock_provider *parent;
3426
3427 if (!of_device_is_available(np))
3428 continue;
3429
3430 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
3431 if (!parent) {
3432 list_for_each_entry_safe(clk_provider, next,
3433 &clk_provider_list, node) {
3434 list_del(&clk_provider->node);
3435 of_node_put(clk_provider->np);
3436 kfree(clk_provider);
3437 }
3438 of_node_put(np);
3439 return;
3440 }
3441
3442 parent->clk_init_cb = match->data;
3443 parent->np = of_node_get(np);
3444 list_add_tail(&parent->node, &clk_provider_list);
3445 }
3446
3447 while (!list_empty(&clk_provider_list)) {
3448 is_init_done = false;
3449 list_for_each_entry_safe(clk_provider, next,
3450 &clk_provider_list, node) {
3451 if (force || parent_ready(clk_provider->np)) {
3452
3453 /* Don't populate platform devices */
3454 of_node_set_flag(clk_provider->np,
3455 OF_POPULATED);
3456
3457 clk_provider->clk_init_cb(clk_provider->np);
3458 of_clk_set_defaults(clk_provider->np, true);
3459
3460 list_del(&clk_provider->node);
3461 of_node_put(clk_provider->np);
3462 kfree(clk_provider);
3463 is_init_done = true;
3464 }
3465 }
3466
3467 /*
3468 * We didn't manage to initialize any of the
3469 * remaining providers during the last loop, so now we
3470 * initialize all the remaining ones unconditionally
3471 * in case the clock parent was not mandatory
3472 */
3473 if (!is_init_done)
3474 force = true;
3475 }
3476}
3477#endif