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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
40/* List of registered clks that use runtime PM */
41static HLIST_HEAD(clk_rpm_list);
42static DEFINE_MUTEX(clk_rpm_list_lock);
43
44static const struct hlist_head *all_lists[] = {
45 &clk_root_list,
46 &clk_orphan_list,
47 NULL,
48};
49
50/*** private data structures ***/
51
52struct clk_parent_map {
53 const struct clk_hw *hw;
54 struct clk_core *core;
55 const char *fw_name;
56 const char *name;
57 int index;
58};
59
60struct clk_core {
61 const char *name;
62 const struct clk_ops *ops;
63 struct clk_hw *hw;
64 struct module *owner;
65 struct device *dev;
66 struct hlist_node rpm_node;
67 struct device_node *of_node;
68 struct clk_core *parent;
69 struct clk_parent_map *parents;
70 u8 num_parents;
71 u8 new_parent_index;
72 unsigned long rate;
73 unsigned long req_rate;
74 unsigned long new_rate;
75 struct clk_core *new_parent;
76 struct clk_core *new_child;
77 unsigned long flags;
78 bool orphan;
79 bool rpm_enabled;
80 unsigned int enable_count;
81 unsigned int prepare_count;
82 unsigned int protect_count;
83 unsigned long min_rate;
84 unsigned long max_rate;
85 unsigned long accuracy;
86 int phase;
87 struct clk_duty duty;
88 struct hlist_head children;
89 struct hlist_node child_node;
90 struct hlist_head clks;
91 unsigned int notifier_count;
92#ifdef CONFIG_DEBUG_FS
93 struct dentry *dentry;
94 struct hlist_node debug_node;
95#endif
96 struct kref ref;
97};
98
99#define CREATE_TRACE_POINTS
100#include <trace/events/clk.h>
101
102struct clk {
103 struct clk_core *core;
104 struct device *dev;
105 const char *dev_id;
106 const char *con_id;
107 unsigned long min_rate;
108 unsigned long max_rate;
109 unsigned int exclusive_count;
110 struct hlist_node clks_node;
111};
112
113/*** runtime pm ***/
114static int clk_pm_runtime_get(struct clk_core *core)
115{
116 if (!core->rpm_enabled)
117 return 0;
118
119 return pm_runtime_resume_and_get(core->dev);
120}
121
122static void clk_pm_runtime_put(struct clk_core *core)
123{
124 if (!core->rpm_enabled)
125 return;
126
127 pm_runtime_put_sync(core->dev);
128}
129
130/**
131 * clk_pm_runtime_get_all() - Runtime "get" all clk provider devices
132 *
133 * Call clk_pm_runtime_get() on all runtime PM enabled clks in the clk tree so
134 * that disabling unused clks avoids a deadlock where a device is runtime PM
135 * resuming/suspending and the runtime PM callback is trying to grab the
136 * prepare_lock for something like clk_prepare_enable() while
137 * clk_disable_unused_subtree() holds the prepare_lock and is trying to runtime
138 * PM resume/suspend the device as well.
139 *
140 * Context: Acquires the 'clk_rpm_list_lock' and returns with the lock held on
141 * success. Otherwise the lock is released on failure.
142 *
143 * Return: 0 on success, negative errno otherwise.
144 */
145static int clk_pm_runtime_get_all(void)
146{
147 int ret;
148 struct clk_core *core, *failed;
149
150 /*
151 * Grab the list lock to prevent any new clks from being registered
152 * or unregistered until clk_pm_runtime_put_all().
153 */
154 mutex_lock(&clk_rpm_list_lock);
155
156 /*
157 * Runtime PM "get" all the devices that are needed for the clks
158 * currently registered. Do this without holding the prepare_lock, to
159 * avoid the deadlock.
160 */
161 hlist_for_each_entry(core, &clk_rpm_list, rpm_node) {
162 ret = clk_pm_runtime_get(core);
163 if (ret) {
164 failed = core;
165 pr_err("clk: Failed to runtime PM get '%s' for clk '%s'\n",
166 dev_name(failed->dev), failed->name);
167 goto err;
168 }
169 }
170
171 return 0;
172
173err:
174 hlist_for_each_entry(core, &clk_rpm_list, rpm_node) {
175 if (core == failed)
176 break;
177
178 clk_pm_runtime_put(core);
179 }
180 mutex_unlock(&clk_rpm_list_lock);
181
182 return ret;
183}
184
185/**
186 * clk_pm_runtime_put_all() - Runtime "put" all clk provider devices
187 *
188 * Put the runtime PM references taken in clk_pm_runtime_get_all() and release
189 * the 'clk_rpm_list_lock'.
190 */
191static void clk_pm_runtime_put_all(void)
192{
193 struct clk_core *core;
194
195 hlist_for_each_entry(core, &clk_rpm_list, rpm_node)
196 clk_pm_runtime_put(core);
197 mutex_unlock(&clk_rpm_list_lock);
198}
199
200static void clk_pm_runtime_init(struct clk_core *core)
201{
202 struct device *dev = core->dev;
203
204 if (dev && pm_runtime_enabled(dev)) {
205 core->rpm_enabled = true;
206
207 mutex_lock(&clk_rpm_list_lock);
208 hlist_add_head(&core->rpm_node, &clk_rpm_list);
209 mutex_unlock(&clk_rpm_list_lock);
210 }
211}
212
213/*** locking ***/
214static void clk_prepare_lock(void)
215{
216 if (!mutex_trylock(&prepare_lock)) {
217 if (prepare_owner == current) {
218 prepare_refcnt++;
219 return;
220 }
221 mutex_lock(&prepare_lock);
222 }
223 WARN_ON_ONCE(prepare_owner != NULL);
224 WARN_ON_ONCE(prepare_refcnt != 0);
225 prepare_owner = current;
226 prepare_refcnt = 1;
227}
228
229static void clk_prepare_unlock(void)
230{
231 WARN_ON_ONCE(prepare_owner != current);
232 WARN_ON_ONCE(prepare_refcnt == 0);
233
234 if (--prepare_refcnt)
235 return;
236 prepare_owner = NULL;
237 mutex_unlock(&prepare_lock);
238}
239
240static unsigned long clk_enable_lock(void)
241 __acquires(enable_lock)
242{
243 unsigned long flags;
244
245 /*
246 * On UP systems, spin_trylock_irqsave() always returns true, even if
247 * we already hold the lock. So, in that case, we rely only on
248 * reference counting.
249 */
250 if (!IS_ENABLED(CONFIG_SMP) ||
251 !spin_trylock_irqsave(&enable_lock, flags)) {
252 if (enable_owner == current) {
253 enable_refcnt++;
254 __acquire(enable_lock);
255 if (!IS_ENABLED(CONFIG_SMP))
256 local_save_flags(flags);
257 return flags;
258 }
259 spin_lock_irqsave(&enable_lock, flags);
260 }
261 WARN_ON_ONCE(enable_owner != NULL);
262 WARN_ON_ONCE(enable_refcnt != 0);
263 enable_owner = current;
264 enable_refcnt = 1;
265 return flags;
266}
267
268static void clk_enable_unlock(unsigned long flags)
269 __releases(enable_lock)
270{
271 WARN_ON_ONCE(enable_owner != current);
272 WARN_ON_ONCE(enable_refcnt == 0);
273
274 if (--enable_refcnt) {
275 __release(enable_lock);
276 return;
277 }
278 enable_owner = NULL;
279 spin_unlock_irqrestore(&enable_lock, flags);
280}
281
282static bool clk_core_rate_is_protected(struct clk_core *core)
283{
284 return core->protect_count;
285}
286
287static bool clk_core_is_prepared(struct clk_core *core)
288{
289 bool ret = false;
290
291 /*
292 * .is_prepared is optional for clocks that can prepare
293 * fall back to software usage counter if it is missing
294 */
295 if (!core->ops->is_prepared)
296 return core->prepare_count;
297
298 if (!clk_pm_runtime_get(core)) {
299 ret = core->ops->is_prepared(core->hw);
300 clk_pm_runtime_put(core);
301 }
302
303 return ret;
304}
305
306static bool clk_core_is_enabled(struct clk_core *core)
307{
308 bool ret = false;
309
310 /*
311 * .is_enabled is only mandatory for clocks that gate
312 * fall back to software usage counter if .is_enabled is missing
313 */
314 if (!core->ops->is_enabled)
315 return core->enable_count;
316
317 /*
318 * Check if clock controller's device is runtime active before
319 * calling .is_enabled callback. If not, assume that clock is
320 * disabled, because we might be called from atomic context, from
321 * which pm_runtime_get() is not allowed.
322 * This function is called mainly from clk_disable_unused_subtree,
323 * which ensures proper runtime pm activation of controller before
324 * taking enable spinlock, but the below check is needed if one tries
325 * to call it from other places.
326 */
327 if (core->rpm_enabled) {
328 pm_runtime_get_noresume(core->dev);
329 if (!pm_runtime_active(core->dev)) {
330 ret = false;
331 goto done;
332 }
333 }
334
335 /*
336 * This could be called with the enable lock held, or from atomic
337 * context. If the parent isn't enabled already, we can't do
338 * anything here. We can also assume this clock isn't enabled.
339 */
340 if ((core->flags & CLK_OPS_PARENT_ENABLE) && core->parent)
341 if (!clk_core_is_enabled(core->parent)) {
342 ret = false;
343 goto done;
344 }
345
346 ret = core->ops->is_enabled(core->hw);
347done:
348 if (core->rpm_enabled)
349 pm_runtime_put(core->dev);
350
351 return ret;
352}
353
354/*** helper functions ***/
355
356const char *__clk_get_name(const struct clk *clk)
357{
358 return !clk ? NULL : clk->core->name;
359}
360EXPORT_SYMBOL_GPL(__clk_get_name);
361
362const char *clk_hw_get_name(const struct clk_hw *hw)
363{
364 return hw->core->name;
365}
366EXPORT_SYMBOL_GPL(clk_hw_get_name);
367
368struct clk_hw *__clk_get_hw(struct clk *clk)
369{
370 return !clk ? NULL : clk->core->hw;
371}
372EXPORT_SYMBOL_GPL(__clk_get_hw);
373
374unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
375{
376 return hw->core->num_parents;
377}
378EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
379
380struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
381{
382 return hw->core->parent ? hw->core->parent->hw : NULL;
383}
384EXPORT_SYMBOL_GPL(clk_hw_get_parent);
385
386static struct clk_core *__clk_lookup_subtree(const char *name,
387 struct clk_core *core)
388{
389 struct clk_core *child;
390 struct clk_core *ret;
391
392 if (!strcmp(core->name, name))
393 return core;
394
395 hlist_for_each_entry(child, &core->children, child_node) {
396 ret = __clk_lookup_subtree(name, child);
397 if (ret)
398 return ret;
399 }
400
401 return NULL;
402}
403
404static struct clk_core *clk_core_lookup(const char *name)
405{
406 struct clk_core *root_clk;
407 struct clk_core *ret;
408
409 if (!name)
410 return NULL;
411
412 /* search the 'proper' clk tree first */
413 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
414 ret = __clk_lookup_subtree(name, root_clk);
415 if (ret)
416 return ret;
417 }
418
419 /* if not found, then search the orphan tree */
420 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
421 ret = __clk_lookup_subtree(name, root_clk);
422 if (ret)
423 return ret;
424 }
425
426 return NULL;
427}
428
429#ifdef CONFIG_OF
430static int of_parse_clkspec(const struct device_node *np, int index,
431 const char *name, struct of_phandle_args *out_args);
432static struct clk_hw *
433of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
434#else
435static inline int of_parse_clkspec(const struct device_node *np, int index,
436 const char *name,
437 struct of_phandle_args *out_args)
438{
439 return -ENOENT;
440}
441static inline struct clk_hw *
442of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
443{
444 return ERR_PTR(-ENOENT);
445}
446#endif
447
448/**
449 * clk_core_get - Find the clk_core parent of a clk
450 * @core: clk to find parent of
451 * @p_index: parent index to search for
452 *
453 * This is the preferred method for clk providers to find the parent of a
454 * clk when that parent is external to the clk controller. The parent_names
455 * array is indexed and treated as a local name matching a string in the device
456 * node's 'clock-names' property or as the 'con_id' matching the device's
457 * dev_name() in a clk_lookup. This allows clk providers to use their own
458 * namespace instead of looking for a globally unique parent string.
459 *
460 * For example the following DT snippet would allow a clock registered by the
461 * clock-controller@c001 that has a clk_init_data::parent_data array
462 * with 'xtal' in the 'name' member to find the clock provided by the
463 * clock-controller@f00abcd without needing to get the globally unique name of
464 * the xtal clk.
465 *
466 * parent: clock-controller@f00abcd {
467 * reg = <0xf00abcd 0xabcd>;
468 * #clock-cells = <0>;
469 * };
470 *
471 * clock-controller@c001 {
472 * reg = <0xc001 0xf00d>;
473 * clocks = <&parent>;
474 * clock-names = "xtal";
475 * #clock-cells = <1>;
476 * };
477 *
478 * Returns: -ENOENT when the provider can't be found or the clk doesn't
479 * exist in the provider or the name can't be found in the DT node or
480 * in a clkdev lookup. NULL when the provider knows about the clk but it
481 * isn't provided on this system.
482 * A valid clk_core pointer when the clk can be found in the provider.
483 */
484static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
485{
486 const char *name = core->parents[p_index].fw_name;
487 int index = core->parents[p_index].index;
488 struct clk_hw *hw = ERR_PTR(-ENOENT);
489 struct device *dev = core->dev;
490 const char *dev_id = dev ? dev_name(dev) : NULL;
491 struct device_node *np = core->of_node;
492 struct of_phandle_args clkspec;
493
494 if (np && (name || index >= 0) &&
495 !of_parse_clkspec(np, index, name, &clkspec)) {
496 hw = of_clk_get_hw_from_clkspec(&clkspec);
497 of_node_put(clkspec.np);
498 } else if (name) {
499 /*
500 * If the DT search above couldn't find the provider fallback to
501 * looking up via clkdev based clk_lookups.
502 */
503 hw = clk_find_hw(dev_id, name);
504 }
505
506 if (IS_ERR(hw))
507 return ERR_CAST(hw);
508
509 if (!hw)
510 return NULL;
511
512 return hw->core;
513}
514
515static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
516{
517 struct clk_parent_map *entry = &core->parents[index];
518 struct clk_core *parent;
519
520 if (entry->hw) {
521 parent = entry->hw->core;
522 } else {
523 parent = clk_core_get(core, index);
524 if (PTR_ERR(parent) == -ENOENT && entry->name)
525 parent = clk_core_lookup(entry->name);
526 }
527
528 /*
529 * We have a direct reference but it isn't registered yet?
530 * Orphan it and let clk_reparent() update the orphan status
531 * when the parent is registered.
532 */
533 if (!parent)
534 parent = ERR_PTR(-EPROBE_DEFER);
535
536 /* Only cache it if it's not an error */
537 if (!IS_ERR(parent))
538 entry->core = parent;
539}
540
541static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
542 u8 index)
543{
544 if (!core || index >= core->num_parents || !core->parents)
545 return NULL;
546
547 if (!core->parents[index].core)
548 clk_core_fill_parent_index(core, index);
549
550 return core->parents[index].core;
551}
552
553struct clk_hw *
554clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
555{
556 struct clk_core *parent;
557
558 parent = clk_core_get_parent_by_index(hw->core, index);
559
560 return !parent ? NULL : parent->hw;
561}
562EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
563
564unsigned int __clk_get_enable_count(struct clk *clk)
565{
566 return !clk ? 0 : clk->core->enable_count;
567}
568
569static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
570{
571 if (!core)
572 return 0;
573
574 if (!core->num_parents || core->parent)
575 return core->rate;
576
577 /*
578 * Clk must have a parent because num_parents > 0 but the parent isn't
579 * known yet. Best to return 0 as the rate of this clk until we can
580 * properly recalc the rate based on the parent's rate.
581 */
582 return 0;
583}
584
585unsigned long clk_hw_get_rate(const struct clk_hw *hw)
586{
587 return clk_core_get_rate_nolock(hw->core);
588}
589EXPORT_SYMBOL_GPL(clk_hw_get_rate);
590
591static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
592{
593 if (!core)
594 return 0;
595
596 return core->accuracy;
597}
598
599unsigned long clk_hw_get_flags(const struct clk_hw *hw)
600{
601 return hw->core->flags;
602}
603EXPORT_SYMBOL_GPL(clk_hw_get_flags);
604
605bool clk_hw_is_prepared(const struct clk_hw *hw)
606{
607 return clk_core_is_prepared(hw->core);
608}
609EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
610
611bool clk_hw_is_enabled(const struct clk_hw *hw)
612{
613 return clk_core_is_enabled(hw->core);
614}
615EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
616
617bool __clk_is_enabled(struct clk *clk)
618{
619 if (!clk)
620 return false;
621
622 return clk_core_is_enabled(clk->core);
623}
624EXPORT_SYMBOL_GPL(__clk_is_enabled);
625
626static bool mux_is_better_rate(unsigned long rate, unsigned long now,
627 unsigned long best, unsigned long flags)
628{
629 if (flags & CLK_MUX_ROUND_CLOSEST)
630 return abs(now - rate) < abs(best - rate);
631
632 return now <= rate && now > best;
633}
634
635static void clk_core_init_rate_req(struct clk_core * const core,
636 struct clk_rate_request *req,
637 unsigned long rate);
638
639static int clk_core_round_rate_nolock(struct clk_core *core,
640 struct clk_rate_request *req);
641
642static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
643{
644 struct clk_core *tmp;
645 unsigned int i;
646
647 /* Optimize for the case where the parent is already the parent. */
648 if (core->parent == parent)
649 return true;
650
651 for (i = 0; i < core->num_parents; i++) {
652 tmp = clk_core_get_parent_by_index(core, i);
653 if (!tmp)
654 continue;
655
656 if (tmp == parent)
657 return true;
658 }
659
660 return false;
661}
662
663static void
664clk_core_forward_rate_req(struct clk_core *core,
665 const struct clk_rate_request *old_req,
666 struct clk_core *parent,
667 struct clk_rate_request *req,
668 unsigned long parent_rate)
669{
670 if (WARN_ON(!clk_core_has_parent(core, parent)))
671 return;
672
673 clk_core_init_rate_req(parent, req, parent_rate);
674
675 if (req->min_rate < old_req->min_rate)
676 req->min_rate = old_req->min_rate;
677
678 if (req->max_rate > old_req->max_rate)
679 req->max_rate = old_req->max_rate;
680}
681
682static int
683clk_core_determine_rate_no_reparent(struct clk_hw *hw,
684 struct clk_rate_request *req)
685{
686 struct clk_core *core = hw->core;
687 struct clk_core *parent = core->parent;
688 unsigned long best;
689 int ret;
690
691 if (core->flags & CLK_SET_RATE_PARENT) {
692 struct clk_rate_request parent_req;
693
694 if (!parent) {
695 req->rate = 0;
696 return 0;
697 }
698
699 clk_core_forward_rate_req(core, req, parent, &parent_req,
700 req->rate);
701
702 trace_clk_rate_request_start(&parent_req);
703
704 ret = clk_core_round_rate_nolock(parent, &parent_req);
705 if (ret)
706 return ret;
707
708 trace_clk_rate_request_done(&parent_req);
709
710 best = parent_req.rate;
711 } else if (parent) {
712 best = clk_core_get_rate_nolock(parent);
713 } else {
714 best = clk_core_get_rate_nolock(core);
715 }
716
717 req->best_parent_rate = best;
718 req->rate = best;
719
720 return 0;
721}
722
723int clk_mux_determine_rate_flags(struct clk_hw *hw,
724 struct clk_rate_request *req,
725 unsigned long flags)
726{
727 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
728 int i, num_parents, ret;
729 unsigned long best = 0;
730
731 /* if NO_REPARENT flag set, pass through to current parent */
732 if (core->flags & CLK_SET_RATE_NO_REPARENT)
733 return clk_core_determine_rate_no_reparent(hw, req);
734
735 /* find the parent that can provide the fastest rate <= rate */
736 num_parents = core->num_parents;
737 for (i = 0; i < num_parents; i++) {
738 unsigned long parent_rate;
739
740 parent = clk_core_get_parent_by_index(core, i);
741 if (!parent)
742 continue;
743
744 if (core->flags & CLK_SET_RATE_PARENT) {
745 struct clk_rate_request parent_req;
746
747 clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
748
749 trace_clk_rate_request_start(&parent_req);
750
751 ret = clk_core_round_rate_nolock(parent, &parent_req);
752 if (ret)
753 continue;
754
755 trace_clk_rate_request_done(&parent_req);
756
757 parent_rate = parent_req.rate;
758 } else {
759 parent_rate = clk_core_get_rate_nolock(parent);
760 }
761
762 if (mux_is_better_rate(req->rate, parent_rate,
763 best, flags)) {
764 best_parent = parent;
765 best = parent_rate;
766 }
767 }
768
769 if (!best_parent)
770 return -EINVAL;
771
772 req->best_parent_hw = best_parent->hw;
773 req->best_parent_rate = best;
774 req->rate = best;
775
776 return 0;
777}
778EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
779
780struct clk *__clk_lookup(const char *name)
781{
782 struct clk_core *core = clk_core_lookup(name);
783
784 return !core ? NULL : core->hw->clk;
785}
786
787static void clk_core_get_boundaries(struct clk_core *core,
788 unsigned long *min_rate,
789 unsigned long *max_rate)
790{
791 struct clk *clk_user;
792
793 lockdep_assert_held(&prepare_lock);
794
795 *min_rate = core->min_rate;
796 *max_rate = core->max_rate;
797
798 hlist_for_each_entry(clk_user, &core->clks, clks_node)
799 *min_rate = max(*min_rate, clk_user->min_rate);
800
801 hlist_for_each_entry(clk_user, &core->clks, clks_node)
802 *max_rate = min(*max_rate, clk_user->max_rate);
803}
804
805/*
806 * clk_hw_get_rate_range() - returns the clock rate range for a hw clk
807 * @hw: the hw clk we want to get the range from
808 * @min_rate: pointer to the variable that will hold the minimum
809 * @max_rate: pointer to the variable that will hold the maximum
810 *
811 * Fills the @min_rate and @max_rate variables with the minimum and
812 * maximum that clock can reach.
813 */
814void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
815 unsigned long *max_rate)
816{
817 clk_core_get_boundaries(hw->core, min_rate, max_rate);
818}
819EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
820
821static bool clk_core_check_boundaries(struct clk_core *core,
822 unsigned long min_rate,
823 unsigned long max_rate)
824{
825 struct clk *user;
826
827 lockdep_assert_held(&prepare_lock);
828
829 if (min_rate > core->max_rate || max_rate < core->min_rate)
830 return false;
831
832 hlist_for_each_entry(user, &core->clks, clks_node)
833 if (min_rate > user->max_rate || max_rate < user->min_rate)
834 return false;
835
836 return true;
837}
838
839void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
840 unsigned long max_rate)
841{
842 hw->core->min_rate = min_rate;
843 hw->core->max_rate = max_rate;
844}
845EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
846
847/*
848 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
849 * @hw: mux type clk to determine rate on
850 * @req: rate request, also used to return preferred parent and frequencies
851 *
852 * Helper for finding best parent to provide a given frequency. This can be used
853 * directly as a determine_rate callback (e.g. for a mux), or from a more
854 * complex clock that may combine a mux with other operations.
855 *
856 * Returns: 0 on success, -EERROR value on error
857 */
858int __clk_mux_determine_rate(struct clk_hw *hw,
859 struct clk_rate_request *req)
860{
861 return clk_mux_determine_rate_flags(hw, req, 0);
862}
863EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
864
865int __clk_mux_determine_rate_closest(struct clk_hw *hw,
866 struct clk_rate_request *req)
867{
868 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
869}
870EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
871
872/*
873 * clk_hw_determine_rate_no_reparent - clk_ops::determine_rate implementation for a clk that doesn't reparent
874 * @hw: mux type clk to determine rate on
875 * @req: rate request, also used to return preferred frequency
876 *
877 * Helper for finding best parent rate to provide a given frequency.
878 * This can be used directly as a determine_rate callback (e.g. for a
879 * mux), or from a more complex clock that may combine a mux with other
880 * operations.
881 *
882 * Returns: 0 on success, -EERROR value on error
883 */
884int clk_hw_determine_rate_no_reparent(struct clk_hw *hw,
885 struct clk_rate_request *req)
886{
887 return clk_core_determine_rate_no_reparent(hw, req);
888}
889EXPORT_SYMBOL_GPL(clk_hw_determine_rate_no_reparent);
890
891/*** clk api ***/
892
893static void clk_core_rate_unprotect(struct clk_core *core)
894{
895 lockdep_assert_held(&prepare_lock);
896
897 if (!core)
898 return;
899
900 if (WARN(core->protect_count == 0,
901 "%s already unprotected\n", core->name))
902 return;
903
904 if (--core->protect_count > 0)
905 return;
906
907 clk_core_rate_unprotect(core->parent);
908}
909
910static int clk_core_rate_nuke_protect(struct clk_core *core)
911{
912 int ret;
913
914 lockdep_assert_held(&prepare_lock);
915
916 if (!core)
917 return -EINVAL;
918
919 if (core->protect_count == 0)
920 return 0;
921
922 ret = core->protect_count;
923 core->protect_count = 1;
924 clk_core_rate_unprotect(core);
925
926 return ret;
927}
928
929/**
930 * clk_rate_exclusive_put - release exclusivity over clock rate control
931 * @clk: the clk over which the exclusivity is released
932 *
933 * clk_rate_exclusive_put() completes a critical section during which a clock
934 * consumer cannot tolerate any other consumer making any operation on the
935 * clock which could result in a rate change or rate glitch. Exclusive clocks
936 * cannot have their rate changed, either directly or indirectly due to changes
937 * further up the parent chain of clocks. As a result, clocks up parent chain
938 * also get under exclusive control of the calling consumer.
939 *
940 * If exlusivity is claimed more than once on clock, even by the same consumer,
941 * the rate effectively gets locked as exclusivity can't be preempted.
942 *
943 * Calls to clk_rate_exclusive_put() must be balanced with calls to
944 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
945 * error status.
946 */
947void clk_rate_exclusive_put(struct clk *clk)
948{
949 if (!clk)
950 return;
951
952 clk_prepare_lock();
953
954 /*
955 * if there is something wrong with this consumer protect count, stop
956 * here before messing with the provider
957 */
958 if (WARN_ON(clk->exclusive_count <= 0))
959 goto out;
960
961 clk_core_rate_unprotect(clk->core);
962 clk->exclusive_count--;
963out:
964 clk_prepare_unlock();
965}
966EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
967
968static void clk_core_rate_protect(struct clk_core *core)
969{
970 lockdep_assert_held(&prepare_lock);
971
972 if (!core)
973 return;
974
975 if (core->protect_count == 0)
976 clk_core_rate_protect(core->parent);
977
978 core->protect_count++;
979}
980
981static void clk_core_rate_restore_protect(struct clk_core *core, int count)
982{
983 lockdep_assert_held(&prepare_lock);
984
985 if (!core)
986 return;
987
988 if (count == 0)
989 return;
990
991 clk_core_rate_protect(core);
992 core->protect_count = count;
993}
994
995/**
996 * clk_rate_exclusive_get - get exclusivity over the clk rate control
997 * @clk: the clk over which the exclusity of rate control is requested
998 *
999 * clk_rate_exclusive_get() begins a critical section during which a clock
1000 * consumer cannot tolerate any other consumer making any operation on the
1001 * clock which could result in a rate change or rate glitch. Exclusive clocks
1002 * cannot have their rate changed, either directly or indirectly due to changes
1003 * further up the parent chain of clocks. As a result, clocks up parent chain
1004 * also get under exclusive control of the calling consumer.
1005 *
1006 * If exlusivity is claimed more than once on clock, even by the same consumer,
1007 * the rate effectively gets locked as exclusivity can't be preempted.
1008 *
1009 * Calls to clk_rate_exclusive_get() should be balanced with calls to
1010 * clk_rate_exclusive_put(). Calls to this function may sleep.
1011 * Returns 0 on success, -EERROR otherwise
1012 */
1013int clk_rate_exclusive_get(struct clk *clk)
1014{
1015 if (!clk)
1016 return 0;
1017
1018 clk_prepare_lock();
1019 clk_core_rate_protect(clk->core);
1020 clk->exclusive_count++;
1021 clk_prepare_unlock();
1022
1023 return 0;
1024}
1025EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
1026
1027static void devm_clk_rate_exclusive_put(void *data)
1028{
1029 struct clk *clk = data;
1030
1031 clk_rate_exclusive_put(clk);
1032}
1033
1034int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk)
1035{
1036 int ret;
1037
1038 ret = clk_rate_exclusive_get(clk);
1039 if (ret)
1040 return ret;
1041
1042 return devm_add_action_or_reset(dev, devm_clk_rate_exclusive_put, clk);
1043}
1044EXPORT_SYMBOL_GPL(devm_clk_rate_exclusive_get);
1045
1046static void clk_core_unprepare(struct clk_core *core)
1047{
1048 lockdep_assert_held(&prepare_lock);
1049
1050 if (!core)
1051 return;
1052
1053 if (WARN(core->prepare_count == 0,
1054 "%s already unprepared\n", core->name))
1055 return;
1056
1057 if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
1058 "Unpreparing critical %s\n", core->name))
1059 return;
1060
1061 if (core->flags & CLK_SET_RATE_GATE)
1062 clk_core_rate_unprotect(core);
1063
1064 if (--core->prepare_count > 0)
1065 return;
1066
1067 WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
1068
1069 trace_clk_unprepare(core);
1070
1071 if (core->ops->unprepare)
1072 core->ops->unprepare(core->hw);
1073
1074 trace_clk_unprepare_complete(core);
1075 clk_core_unprepare(core->parent);
1076 clk_pm_runtime_put(core);
1077}
1078
1079static void clk_core_unprepare_lock(struct clk_core *core)
1080{
1081 clk_prepare_lock();
1082 clk_core_unprepare(core);
1083 clk_prepare_unlock();
1084}
1085
1086/**
1087 * clk_unprepare - undo preparation of a clock source
1088 * @clk: the clk being unprepared
1089 *
1090 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
1091 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
1092 * if the operation may sleep. One example is a clk which is accessed over
1093 * I2c. In the complex case a clk gate operation may require a fast and a slow
1094 * part. It is this reason that clk_unprepare and clk_disable are not mutually
1095 * exclusive. In fact clk_disable must be called before clk_unprepare.
1096 */
1097void clk_unprepare(struct clk *clk)
1098{
1099 if (IS_ERR_OR_NULL(clk))
1100 return;
1101
1102 clk_core_unprepare_lock(clk->core);
1103}
1104EXPORT_SYMBOL_GPL(clk_unprepare);
1105
1106static int clk_core_prepare(struct clk_core *core)
1107{
1108 int ret = 0;
1109
1110 lockdep_assert_held(&prepare_lock);
1111
1112 if (!core)
1113 return 0;
1114
1115 if (core->prepare_count == 0) {
1116 ret = clk_pm_runtime_get(core);
1117 if (ret)
1118 return ret;
1119
1120 ret = clk_core_prepare(core->parent);
1121 if (ret)
1122 goto runtime_put;
1123
1124 trace_clk_prepare(core);
1125
1126 if (core->ops->prepare)
1127 ret = core->ops->prepare(core->hw);
1128
1129 trace_clk_prepare_complete(core);
1130
1131 if (ret)
1132 goto unprepare;
1133 }
1134
1135 core->prepare_count++;
1136
1137 /*
1138 * CLK_SET_RATE_GATE is a special case of clock protection
1139 * Instead of a consumer claiming exclusive rate control, it is
1140 * actually the provider which prevents any consumer from making any
1141 * operation which could result in a rate change or rate glitch while
1142 * the clock is prepared.
1143 */
1144 if (core->flags & CLK_SET_RATE_GATE)
1145 clk_core_rate_protect(core);
1146
1147 return 0;
1148unprepare:
1149 clk_core_unprepare(core->parent);
1150runtime_put:
1151 clk_pm_runtime_put(core);
1152 return ret;
1153}
1154
1155static int clk_core_prepare_lock(struct clk_core *core)
1156{
1157 int ret;
1158
1159 clk_prepare_lock();
1160 ret = clk_core_prepare(core);
1161 clk_prepare_unlock();
1162
1163 return ret;
1164}
1165
1166/**
1167 * clk_prepare - prepare a clock source
1168 * @clk: the clk being prepared
1169 *
1170 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
1171 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
1172 * operation may sleep. One example is a clk which is accessed over I2c. In
1173 * the complex case a clk ungate operation may require a fast and a slow part.
1174 * It is this reason that clk_prepare and clk_enable are not mutually
1175 * exclusive. In fact clk_prepare must be called before clk_enable.
1176 * Returns 0 on success, -EERROR otherwise.
1177 */
1178int clk_prepare(struct clk *clk)
1179{
1180 if (!clk)
1181 return 0;
1182
1183 return clk_core_prepare_lock(clk->core);
1184}
1185EXPORT_SYMBOL_GPL(clk_prepare);
1186
1187static void clk_core_disable(struct clk_core *core)
1188{
1189 lockdep_assert_held(&enable_lock);
1190
1191 if (!core)
1192 return;
1193
1194 if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
1195 return;
1196
1197 if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
1198 "Disabling critical %s\n", core->name))
1199 return;
1200
1201 if (--core->enable_count > 0)
1202 return;
1203
1204 trace_clk_disable(core);
1205
1206 if (core->ops->disable)
1207 core->ops->disable(core->hw);
1208
1209 trace_clk_disable_complete(core);
1210
1211 clk_core_disable(core->parent);
1212}
1213
1214static void clk_core_disable_lock(struct clk_core *core)
1215{
1216 unsigned long flags;
1217
1218 flags = clk_enable_lock();
1219 clk_core_disable(core);
1220 clk_enable_unlock(flags);
1221}
1222
1223/**
1224 * clk_disable - gate a clock
1225 * @clk: the clk being gated
1226 *
1227 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
1228 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1229 * clk if the operation is fast and will never sleep. One example is a
1230 * SoC-internal clk which is controlled via simple register writes. In the
1231 * complex case a clk gate operation may require a fast and a slow part. It is
1232 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1233 * In fact clk_disable must be called before clk_unprepare.
1234 */
1235void clk_disable(struct clk *clk)
1236{
1237 if (IS_ERR_OR_NULL(clk))
1238 return;
1239
1240 clk_core_disable_lock(clk->core);
1241}
1242EXPORT_SYMBOL_GPL(clk_disable);
1243
1244static int clk_core_enable(struct clk_core *core)
1245{
1246 int ret = 0;
1247
1248 lockdep_assert_held(&enable_lock);
1249
1250 if (!core)
1251 return 0;
1252
1253 if (WARN(core->prepare_count == 0,
1254 "Enabling unprepared %s\n", core->name))
1255 return -ESHUTDOWN;
1256
1257 if (core->enable_count == 0) {
1258 ret = clk_core_enable(core->parent);
1259
1260 if (ret)
1261 return ret;
1262
1263 trace_clk_enable(core);
1264
1265 if (core->ops->enable)
1266 ret = core->ops->enable(core->hw);
1267
1268 trace_clk_enable_complete(core);
1269
1270 if (ret) {
1271 clk_core_disable(core->parent);
1272 return ret;
1273 }
1274 }
1275
1276 core->enable_count++;
1277 return 0;
1278}
1279
1280static int clk_core_enable_lock(struct clk_core *core)
1281{
1282 unsigned long flags;
1283 int ret;
1284
1285 flags = clk_enable_lock();
1286 ret = clk_core_enable(core);
1287 clk_enable_unlock(flags);
1288
1289 return ret;
1290}
1291
1292/**
1293 * clk_gate_restore_context - restore context for poweroff
1294 * @hw: the clk_hw pointer of clock whose state is to be restored
1295 *
1296 * The clock gate restore context function enables or disables
1297 * the gate clocks based on the enable_count. This is done in cases
1298 * where the clock context is lost and based on the enable_count
1299 * the clock either needs to be enabled/disabled. This
1300 * helps restore the state of gate clocks.
1301 */
1302void clk_gate_restore_context(struct clk_hw *hw)
1303{
1304 struct clk_core *core = hw->core;
1305
1306 if (core->enable_count)
1307 core->ops->enable(hw);
1308 else
1309 core->ops->disable(hw);
1310}
1311EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1312
1313static int clk_core_save_context(struct clk_core *core)
1314{
1315 struct clk_core *child;
1316 int ret = 0;
1317
1318 hlist_for_each_entry(child, &core->children, child_node) {
1319 ret = clk_core_save_context(child);
1320 if (ret < 0)
1321 return ret;
1322 }
1323
1324 if (core->ops && core->ops->save_context)
1325 ret = core->ops->save_context(core->hw);
1326
1327 return ret;
1328}
1329
1330static void clk_core_restore_context(struct clk_core *core)
1331{
1332 struct clk_core *child;
1333
1334 if (core->ops && core->ops->restore_context)
1335 core->ops->restore_context(core->hw);
1336
1337 hlist_for_each_entry(child, &core->children, child_node)
1338 clk_core_restore_context(child);
1339}
1340
1341/**
1342 * clk_save_context - save clock context for poweroff
1343 *
1344 * Saves the context of the clock register for powerstates in which the
1345 * contents of the registers will be lost. Occurs deep within the suspend
1346 * code. Returns 0 on success.
1347 */
1348int clk_save_context(void)
1349{
1350 struct clk_core *clk;
1351 int ret;
1352
1353 hlist_for_each_entry(clk, &clk_root_list, child_node) {
1354 ret = clk_core_save_context(clk);
1355 if (ret < 0)
1356 return ret;
1357 }
1358
1359 hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1360 ret = clk_core_save_context(clk);
1361 if (ret < 0)
1362 return ret;
1363 }
1364
1365 return 0;
1366}
1367EXPORT_SYMBOL_GPL(clk_save_context);
1368
1369/**
1370 * clk_restore_context - restore clock context after poweroff
1371 *
1372 * Restore the saved clock context upon resume.
1373 *
1374 */
1375void clk_restore_context(void)
1376{
1377 struct clk_core *core;
1378
1379 hlist_for_each_entry(core, &clk_root_list, child_node)
1380 clk_core_restore_context(core);
1381
1382 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1383 clk_core_restore_context(core);
1384}
1385EXPORT_SYMBOL_GPL(clk_restore_context);
1386
1387/**
1388 * clk_enable - ungate a clock
1389 * @clk: the clk being ungated
1390 *
1391 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
1392 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1393 * if the operation will never sleep. One example is a SoC-internal clk which
1394 * is controlled via simple register writes. In the complex case a clk ungate
1395 * operation may require a fast and a slow part. It is this reason that
1396 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
1397 * must be called before clk_enable. Returns 0 on success, -EERROR
1398 * otherwise.
1399 */
1400int clk_enable(struct clk *clk)
1401{
1402 if (!clk)
1403 return 0;
1404
1405 return clk_core_enable_lock(clk->core);
1406}
1407EXPORT_SYMBOL_GPL(clk_enable);
1408
1409/**
1410 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1411 * @clk: clock source
1412 *
1413 * Returns true if clk_prepare() implicitly enables the clock, effectively
1414 * making clk_enable()/clk_disable() no-ops, false otherwise.
1415 *
1416 * This is of interest mainly to power management code where actually
1417 * disabling the clock also requires unpreparing it to have any material
1418 * effect.
1419 *
1420 * Regardless of the value returned here, the caller must always invoke
1421 * clk_enable() or clk_prepare_enable() and counterparts for usage counts
1422 * to be right.
1423 */
1424bool clk_is_enabled_when_prepared(struct clk *clk)
1425{
1426 return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1427}
1428EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1429
1430static int clk_core_prepare_enable(struct clk_core *core)
1431{
1432 int ret;
1433
1434 ret = clk_core_prepare_lock(core);
1435 if (ret)
1436 return ret;
1437
1438 ret = clk_core_enable_lock(core);
1439 if (ret)
1440 clk_core_unprepare_lock(core);
1441
1442 return ret;
1443}
1444
1445static void clk_core_disable_unprepare(struct clk_core *core)
1446{
1447 clk_core_disable_lock(core);
1448 clk_core_unprepare_lock(core);
1449}
1450
1451static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1452{
1453 struct clk_core *child;
1454
1455 lockdep_assert_held(&prepare_lock);
1456
1457 hlist_for_each_entry(child, &core->children, child_node)
1458 clk_unprepare_unused_subtree(child);
1459
1460 if (core->prepare_count)
1461 return;
1462
1463 if (core->flags & CLK_IGNORE_UNUSED)
1464 return;
1465
1466 if (clk_core_is_prepared(core)) {
1467 trace_clk_unprepare(core);
1468 if (core->ops->unprepare_unused)
1469 core->ops->unprepare_unused(core->hw);
1470 else if (core->ops->unprepare)
1471 core->ops->unprepare(core->hw);
1472 trace_clk_unprepare_complete(core);
1473 }
1474}
1475
1476static void __init clk_disable_unused_subtree(struct clk_core *core)
1477{
1478 struct clk_core *child;
1479 unsigned long flags;
1480
1481 lockdep_assert_held(&prepare_lock);
1482
1483 hlist_for_each_entry(child, &core->children, child_node)
1484 clk_disable_unused_subtree(child);
1485
1486 if (core->flags & CLK_OPS_PARENT_ENABLE)
1487 clk_core_prepare_enable(core->parent);
1488
1489 flags = clk_enable_lock();
1490
1491 if (core->enable_count)
1492 goto unlock_out;
1493
1494 if (core->flags & CLK_IGNORE_UNUSED)
1495 goto unlock_out;
1496
1497 /*
1498 * some gate clocks have special needs during the disable-unused
1499 * sequence. call .disable_unused if available, otherwise fall
1500 * back to .disable
1501 */
1502 if (clk_core_is_enabled(core)) {
1503 trace_clk_disable(core);
1504 if (core->ops->disable_unused)
1505 core->ops->disable_unused(core->hw);
1506 else if (core->ops->disable)
1507 core->ops->disable(core->hw);
1508 trace_clk_disable_complete(core);
1509 }
1510
1511unlock_out:
1512 clk_enable_unlock(flags);
1513 if (core->flags & CLK_OPS_PARENT_ENABLE)
1514 clk_core_disable_unprepare(core->parent);
1515}
1516
1517static bool clk_ignore_unused __initdata;
1518static int __init clk_ignore_unused_setup(char *__unused)
1519{
1520 clk_ignore_unused = true;
1521 return 1;
1522}
1523__setup("clk_ignore_unused", clk_ignore_unused_setup);
1524
1525static int __init clk_disable_unused(void)
1526{
1527 struct clk_core *core;
1528 int ret;
1529
1530 if (clk_ignore_unused) {
1531 pr_warn("clk: Not disabling unused clocks\n");
1532 return 0;
1533 }
1534
1535 pr_info("clk: Disabling unused clocks\n");
1536
1537 ret = clk_pm_runtime_get_all();
1538 if (ret)
1539 return ret;
1540 /*
1541 * Grab the prepare lock to keep the clk topology stable while iterating
1542 * over clks.
1543 */
1544 clk_prepare_lock();
1545
1546 hlist_for_each_entry(core, &clk_root_list, child_node)
1547 clk_disable_unused_subtree(core);
1548
1549 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1550 clk_disable_unused_subtree(core);
1551
1552 hlist_for_each_entry(core, &clk_root_list, child_node)
1553 clk_unprepare_unused_subtree(core);
1554
1555 hlist_for_each_entry(core, &clk_orphan_list, child_node)
1556 clk_unprepare_unused_subtree(core);
1557
1558 clk_prepare_unlock();
1559
1560 clk_pm_runtime_put_all();
1561
1562 return 0;
1563}
1564late_initcall_sync(clk_disable_unused);
1565
1566static int clk_core_determine_round_nolock(struct clk_core *core,
1567 struct clk_rate_request *req)
1568{
1569 long rate;
1570
1571 lockdep_assert_held(&prepare_lock);
1572
1573 if (!core)
1574 return 0;
1575
1576 /*
1577 * Some clock providers hand-craft their clk_rate_requests and
1578 * might not fill min_rate and max_rate.
1579 *
1580 * If it's the case, clamping the rate is equivalent to setting
1581 * the rate to 0 which is bad. Skip the clamping but complain so
1582 * that it gets fixed, hopefully.
1583 */
1584 if (!req->min_rate && !req->max_rate)
1585 pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
1586 __func__, core->name);
1587 else
1588 req->rate = clamp(req->rate, req->min_rate, req->max_rate);
1589
1590 /*
1591 * At this point, core protection will be disabled
1592 * - if the provider is not protected at all
1593 * - if the calling consumer is the only one which has exclusivity
1594 * over the provider
1595 */
1596 if (clk_core_rate_is_protected(core)) {
1597 req->rate = core->rate;
1598 } else if (core->ops->determine_rate) {
1599 return core->ops->determine_rate(core->hw, req);
1600 } else if (core->ops->round_rate) {
1601 rate = core->ops->round_rate(core->hw, req->rate,
1602 &req->best_parent_rate);
1603 if (rate < 0)
1604 return rate;
1605
1606 req->rate = rate;
1607 } else {
1608 return -EINVAL;
1609 }
1610
1611 return 0;
1612}
1613
1614static void clk_core_init_rate_req(struct clk_core * const core,
1615 struct clk_rate_request *req,
1616 unsigned long rate)
1617{
1618 struct clk_core *parent;
1619
1620 if (WARN_ON(!req))
1621 return;
1622
1623 memset(req, 0, sizeof(*req));
1624 req->max_rate = ULONG_MAX;
1625
1626 if (!core)
1627 return;
1628
1629 req->core = core;
1630 req->rate = rate;
1631 clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
1632
1633 parent = core->parent;
1634 if (parent) {
1635 req->best_parent_hw = parent->hw;
1636 req->best_parent_rate = parent->rate;
1637 } else {
1638 req->best_parent_hw = NULL;
1639 req->best_parent_rate = 0;
1640 }
1641}
1642
1643/**
1644 * clk_hw_init_rate_request - Initializes a clk_rate_request
1645 * @hw: the clk for which we want to submit a rate request
1646 * @req: the clk_rate_request structure we want to initialise
1647 * @rate: the rate which is to be requested
1648 *
1649 * Initializes a clk_rate_request structure to submit to
1650 * __clk_determine_rate() or similar functions.
1651 */
1652void clk_hw_init_rate_request(const struct clk_hw *hw,
1653 struct clk_rate_request *req,
1654 unsigned long rate)
1655{
1656 if (WARN_ON(!hw || !req))
1657 return;
1658
1659 clk_core_init_rate_req(hw->core, req, rate);
1660}
1661EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
1662
1663/**
1664 * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
1665 * @hw: the original clock that got the rate request
1666 * @old_req: the original clk_rate_request structure we want to forward
1667 * @parent: the clk we want to forward @old_req to
1668 * @req: the clk_rate_request structure we want to initialise
1669 * @parent_rate: The rate which is to be requested to @parent
1670 *
1671 * Initializes a clk_rate_request structure to submit to a clock parent
1672 * in __clk_determine_rate() or similar functions.
1673 */
1674void clk_hw_forward_rate_request(const struct clk_hw *hw,
1675 const struct clk_rate_request *old_req,
1676 const struct clk_hw *parent,
1677 struct clk_rate_request *req,
1678 unsigned long parent_rate)
1679{
1680 if (WARN_ON(!hw || !old_req || !parent || !req))
1681 return;
1682
1683 clk_core_forward_rate_req(hw->core, old_req,
1684 parent->core, req,
1685 parent_rate);
1686}
1687EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);
1688
1689static bool clk_core_can_round(struct clk_core * const core)
1690{
1691 return core->ops->determine_rate || core->ops->round_rate;
1692}
1693
1694static int clk_core_round_rate_nolock(struct clk_core *core,
1695 struct clk_rate_request *req)
1696{
1697 int ret;
1698
1699 lockdep_assert_held(&prepare_lock);
1700
1701 if (!core) {
1702 req->rate = 0;
1703 return 0;
1704 }
1705
1706 if (clk_core_can_round(core))
1707 return clk_core_determine_round_nolock(core, req);
1708
1709 if (core->flags & CLK_SET_RATE_PARENT) {
1710 struct clk_rate_request parent_req;
1711
1712 clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
1713
1714 trace_clk_rate_request_start(&parent_req);
1715
1716 ret = clk_core_round_rate_nolock(core->parent, &parent_req);
1717 if (ret)
1718 return ret;
1719
1720 trace_clk_rate_request_done(&parent_req);
1721
1722 req->best_parent_rate = parent_req.rate;
1723 req->rate = parent_req.rate;
1724
1725 return 0;
1726 }
1727
1728 req->rate = core->rate;
1729 return 0;
1730}
1731
1732/**
1733 * __clk_determine_rate - get the closest rate actually supported by a clock
1734 * @hw: determine the rate of this clock
1735 * @req: target rate request
1736 *
1737 * Useful for clk_ops such as .set_rate and .determine_rate.
1738 */
1739int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1740{
1741 if (!hw) {
1742 req->rate = 0;
1743 return 0;
1744 }
1745
1746 return clk_core_round_rate_nolock(hw->core, req);
1747}
1748EXPORT_SYMBOL_GPL(__clk_determine_rate);
1749
1750/**
1751 * clk_hw_round_rate() - round the given rate for a hw clk
1752 * @hw: the hw clk for which we are rounding a rate
1753 * @rate: the rate which is to be rounded
1754 *
1755 * Takes in a rate as input and rounds it to a rate that the clk can actually
1756 * use.
1757 *
1758 * Context: prepare_lock must be held.
1759 * For clk providers to call from within clk_ops such as .round_rate,
1760 * .determine_rate.
1761 *
1762 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1763 * else returns the parent rate.
1764 */
1765unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1766{
1767 int ret;
1768 struct clk_rate_request req;
1769
1770 clk_core_init_rate_req(hw->core, &req, rate);
1771
1772 trace_clk_rate_request_start(&req);
1773
1774 ret = clk_core_round_rate_nolock(hw->core, &req);
1775 if (ret)
1776 return 0;
1777
1778 trace_clk_rate_request_done(&req);
1779
1780 return req.rate;
1781}
1782EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1783
1784/**
1785 * clk_round_rate - round the given rate for a clk
1786 * @clk: the clk for which we are rounding a rate
1787 * @rate: the rate which is to be rounded
1788 *
1789 * Takes in a rate as input and rounds it to a rate that the clk can actually
1790 * use which is then returned. If clk doesn't support round_rate operation
1791 * then the parent rate is returned.
1792 */
1793long clk_round_rate(struct clk *clk, unsigned long rate)
1794{
1795 struct clk_rate_request req;
1796 int ret;
1797
1798 if (!clk)
1799 return 0;
1800
1801 clk_prepare_lock();
1802
1803 if (clk->exclusive_count)
1804 clk_core_rate_unprotect(clk->core);
1805
1806 clk_core_init_rate_req(clk->core, &req, rate);
1807
1808 trace_clk_rate_request_start(&req);
1809
1810 ret = clk_core_round_rate_nolock(clk->core, &req);
1811
1812 trace_clk_rate_request_done(&req);
1813
1814 if (clk->exclusive_count)
1815 clk_core_rate_protect(clk->core);
1816
1817 clk_prepare_unlock();
1818
1819 if (ret)
1820 return ret;
1821
1822 return req.rate;
1823}
1824EXPORT_SYMBOL_GPL(clk_round_rate);
1825
1826/**
1827 * __clk_notify - call clk notifier chain
1828 * @core: clk that is changing rate
1829 * @msg: clk notifier type (see include/linux/clk.h)
1830 * @old_rate: old clk rate
1831 * @new_rate: new clk rate
1832 *
1833 * Triggers a notifier call chain on the clk rate-change notification
1834 * for 'clk'. Passes a pointer to the struct clk and the previous
1835 * and current rates to the notifier callback. Intended to be called by
1836 * internal clock code only. Returns NOTIFY_DONE from the last driver
1837 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1838 * a driver returns that.
1839 */
1840static int __clk_notify(struct clk_core *core, unsigned long msg,
1841 unsigned long old_rate, unsigned long new_rate)
1842{
1843 struct clk_notifier *cn;
1844 struct clk_notifier_data cnd;
1845 int ret = NOTIFY_DONE;
1846
1847 cnd.old_rate = old_rate;
1848 cnd.new_rate = new_rate;
1849
1850 list_for_each_entry(cn, &clk_notifier_list, node) {
1851 if (cn->clk->core == core) {
1852 cnd.clk = cn->clk;
1853 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1854 &cnd);
1855 if (ret & NOTIFY_STOP_MASK)
1856 return ret;
1857 }
1858 }
1859
1860 return ret;
1861}
1862
1863/**
1864 * __clk_recalc_accuracies
1865 * @core: first clk in the subtree
1866 *
1867 * Walks the subtree of clks starting with clk and recalculates accuracies as
1868 * it goes. Note that if a clk does not implement the .recalc_accuracy
1869 * callback then it is assumed that the clock will take on the accuracy of its
1870 * parent.
1871 */
1872static void __clk_recalc_accuracies(struct clk_core *core)
1873{
1874 unsigned long parent_accuracy = 0;
1875 struct clk_core *child;
1876
1877 lockdep_assert_held(&prepare_lock);
1878
1879 if (core->parent)
1880 parent_accuracy = core->parent->accuracy;
1881
1882 if (core->ops->recalc_accuracy)
1883 core->accuracy = core->ops->recalc_accuracy(core->hw,
1884 parent_accuracy);
1885 else
1886 core->accuracy = parent_accuracy;
1887
1888 hlist_for_each_entry(child, &core->children, child_node)
1889 __clk_recalc_accuracies(child);
1890}
1891
1892static long clk_core_get_accuracy_recalc(struct clk_core *core)
1893{
1894 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1895 __clk_recalc_accuracies(core);
1896
1897 return clk_core_get_accuracy_no_lock(core);
1898}
1899
1900/**
1901 * clk_get_accuracy - return the accuracy of clk
1902 * @clk: the clk whose accuracy is being returned
1903 *
1904 * Simply returns the cached accuracy of the clk, unless
1905 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1906 * issued.
1907 * If clk is NULL then returns 0.
1908 */
1909long clk_get_accuracy(struct clk *clk)
1910{
1911 long accuracy;
1912
1913 if (!clk)
1914 return 0;
1915
1916 clk_prepare_lock();
1917 accuracy = clk_core_get_accuracy_recalc(clk->core);
1918 clk_prepare_unlock();
1919
1920 return accuracy;
1921}
1922EXPORT_SYMBOL_GPL(clk_get_accuracy);
1923
1924static unsigned long clk_recalc(struct clk_core *core,
1925 unsigned long parent_rate)
1926{
1927 unsigned long rate = parent_rate;
1928
1929 if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1930 rate = core->ops->recalc_rate(core->hw, parent_rate);
1931 clk_pm_runtime_put(core);
1932 }
1933 return rate;
1934}
1935
1936/**
1937 * __clk_recalc_rates
1938 * @core: first clk in the subtree
1939 * @update_req: Whether req_rate should be updated with the new rate
1940 * @msg: notification type (see include/linux/clk.h)
1941 *
1942 * Walks the subtree of clks starting with clk and recalculates rates as it
1943 * goes. Note that if a clk does not implement the .recalc_rate callback then
1944 * it is assumed that the clock will take on the rate of its parent.
1945 *
1946 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1947 * if necessary.
1948 */
1949static void __clk_recalc_rates(struct clk_core *core, bool update_req,
1950 unsigned long msg)
1951{
1952 unsigned long old_rate;
1953 unsigned long parent_rate = 0;
1954 struct clk_core *child;
1955
1956 lockdep_assert_held(&prepare_lock);
1957
1958 old_rate = core->rate;
1959
1960 if (core->parent)
1961 parent_rate = core->parent->rate;
1962
1963 core->rate = clk_recalc(core, parent_rate);
1964 if (update_req)
1965 core->req_rate = core->rate;
1966
1967 /*
1968 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1969 * & ABORT_RATE_CHANGE notifiers
1970 */
1971 if (core->notifier_count && msg)
1972 __clk_notify(core, msg, old_rate, core->rate);
1973
1974 hlist_for_each_entry(child, &core->children, child_node)
1975 __clk_recalc_rates(child, update_req, msg);
1976}
1977
1978static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1979{
1980 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1981 __clk_recalc_rates(core, false, 0);
1982
1983 return clk_core_get_rate_nolock(core);
1984}
1985
1986/**
1987 * clk_get_rate - return the rate of clk
1988 * @clk: the clk whose rate is being returned
1989 *
1990 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1991 * is set, which means a recalc_rate will be issued. Can be called regardless of
1992 * the clock enabledness. If clk is NULL, or if an error occurred, then returns
1993 * 0.
1994 */
1995unsigned long clk_get_rate(struct clk *clk)
1996{
1997 unsigned long rate;
1998
1999 if (!clk)
2000 return 0;
2001
2002 clk_prepare_lock();
2003 rate = clk_core_get_rate_recalc(clk->core);
2004 clk_prepare_unlock();
2005
2006 return rate;
2007}
2008EXPORT_SYMBOL_GPL(clk_get_rate);
2009
2010static int clk_fetch_parent_index(struct clk_core *core,
2011 struct clk_core *parent)
2012{
2013 int i;
2014
2015 if (!parent)
2016 return -EINVAL;
2017
2018 for (i = 0; i < core->num_parents; i++) {
2019 /* Found it first try! */
2020 if (core->parents[i].core == parent)
2021 return i;
2022
2023 /* Something else is here, so keep looking */
2024 if (core->parents[i].core)
2025 continue;
2026
2027 /* Maybe core hasn't been cached but the hw is all we know? */
2028 if (core->parents[i].hw) {
2029 if (core->parents[i].hw == parent->hw)
2030 break;
2031
2032 /* Didn't match, but we're expecting a clk_hw */
2033 continue;
2034 }
2035
2036 /* Maybe it hasn't been cached (clk_set_parent() path) */
2037 if (parent == clk_core_get(core, i))
2038 break;
2039
2040 /* Fallback to comparing globally unique names */
2041 if (core->parents[i].name &&
2042 !strcmp(parent->name, core->parents[i].name))
2043 break;
2044 }
2045
2046 if (i == core->num_parents)
2047 return -EINVAL;
2048
2049 core->parents[i].core = parent;
2050 return i;
2051}
2052
2053/**
2054 * clk_hw_get_parent_index - return the index of the parent clock
2055 * @hw: clk_hw associated with the clk being consumed
2056 *
2057 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
2058 * clock does not have a current parent.
2059 */
2060int clk_hw_get_parent_index(struct clk_hw *hw)
2061{
2062 struct clk_hw *parent = clk_hw_get_parent(hw);
2063
2064 if (WARN_ON(parent == NULL))
2065 return -EINVAL;
2066
2067 return clk_fetch_parent_index(hw->core, parent->core);
2068}
2069EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
2070
2071/*
2072 * Update the orphan status of @core and all its children.
2073 */
2074static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
2075{
2076 struct clk_core *child;
2077
2078 core->orphan = is_orphan;
2079
2080 hlist_for_each_entry(child, &core->children, child_node)
2081 clk_core_update_orphan_status(child, is_orphan);
2082}
2083
2084static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
2085{
2086 bool was_orphan = core->orphan;
2087
2088 hlist_del(&core->child_node);
2089
2090 if (new_parent) {
2091 bool becomes_orphan = new_parent->orphan;
2092
2093 /* avoid duplicate POST_RATE_CHANGE notifications */
2094 if (new_parent->new_child == core)
2095 new_parent->new_child = NULL;
2096
2097 hlist_add_head(&core->child_node, &new_parent->children);
2098
2099 if (was_orphan != becomes_orphan)
2100 clk_core_update_orphan_status(core, becomes_orphan);
2101 } else {
2102 hlist_add_head(&core->child_node, &clk_orphan_list);
2103 if (!was_orphan)
2104 clk_core_update_orphan_status(core, true);
2105 }
2106
2107 core->parent = new_parent;
2108}
2109
2110static struct clk_core *__clk_set_parent_before(struct clk_core *core,
2111 struct clk_core *parent)
2112{
2113 unsigned long flags;
2114 struct clk_core *old_parent = core->parent;
2115
2116 /*
2117 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
2118 *
2119 * 2. Migrate prepare state between parents and prevent race with
2120 * clk_enable().
2121 *
2122 * If the clock is not prepared, then a race with
2123 * clk_enable/disable() is impossible since we already have the
2124 * prepare lock (future calls to clk_enable() need to be preceded by
2125 * a clk_prepare()).
2126 *
2127 * If the clock is prepared, migrate the prepared state to the new
2128 * parent and also protect against a race with clk_enable() by
2129 * forcing the clock and the new parent on. This ensures that all
2130 * future calls to clk_enable() are practically NOPs with respect to
2131 * hardware and software states.
2132 *
2133 * See also: Comment for clk_set_parent() below.
2134 */
2135
2136 /* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
2137 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2138 clk_core_prepare_enable(old_parent);
2139 clk_core_prepare_enable(parent);
2140 }
2141
2142 /* migrate prepare count if > 0 */
2143 if (core->prepare_count) {
2144 clk_core_prepare_enable(parent);
2145 clk_core_enable_lock(core);
2146 }
2147
2148 /* update the clk tree topology */
2149 flags = clk_enable_lock();
2150 clk_reparent(core, parent);
2151 clk_enable_unlock(flags);
2152
2153 return old_parent;
2154}
2155
2156static void __clk_set_parent_after(struct clk_core *core,
2157 struct clk_core *parent,
2158 struct clk_core *old_parent)
2159{
2160 /*
2161 * Finish the migration of prepare state and undo the changes done
2162 * for preventing a race with clk_enable().
2163 */
2164 if (core->prepare_count) {
2165 clk_core_disable_lock(core);
2166 clk_core_disable_unprepare(old_parent);
2167 }
2168
2169 /* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
2170 if (core->flags & CLK_OPS_PARENT_ENABLE) {
2171 clk_core_disable_unprepare(parent);
2172 clk_core_disable_unprepare(old_parent);
2173 }
2174}
2175
2176static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
2177 u8 p_index)
2178{
2179 unsigned long flags;
2180 int ret = 0;
2181 struct clk_core *old_parent;
2182
2183 old_parent = __clk_set_parent_before(core, parent);
2184
2185 trace_clk_set_parent(core, parent);
2186
2187 /* change clock input source */
2188 if (parent && core->ops->set_parent)
2189 ret = core->ops->set_parent(core->hw, p_index);
2190
2191 trace_clk_set_parent_complete(core, parent);
2192
2193 if (ret) {
2194 flags = clk_enable_lock();
2195 clk_reparent(core, old_parent);
2196 clk_enable_unlock(flags);
2197
2198 __clk_set_parent_after(core, old_parent, parent);
2199
2200 return ret;
2201 }
2202
2203 __clk_set_parent_after(core, parent, old_parent);
2204
2205 return 0;
2206}
2207
2208/**
2209 * __clk_speculate_rates
2210 * @core: first clk in the subtree
2211 * @parent_rate: the "future" rate of clk's parent
2212 *
2213 * Walks the subtree of clks starting with clk, speculating rates as it
2214 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
2215 *
2216 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
2217 * pre-rate change notifications and returns early if no clks in the
2218 * subtree have subscribed to the notifications. Note that if a clk does not
2219 * implement the .recalc_rate callback then it is assumed that the clock will
2220 * take on the rate of its parent.
2221 */
2222static int __clk_speculate_rates(struct clk_core *core,
2223 unsigned long parent_rate)
2224{
2225 struct clk_core *child;
2226 unsigned long new_rate;
2227 int ret = NOTIFY_DONE;
2228
2229 lockdep_assert_held(&prepare_lock);
2230
2231 new_rate = clk_recalc(core, parent_rate);
2232
2233 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
2234 if (core->notifier_count)
2235 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
2236
2237 if (ret & NOTIFY_STOP_MASK) {
2238 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
2239 __func__, core->name, ret);
2240 goto out;
2241 }
2242
2243 hlist_for_each_entry(child, &core->children, child_node) {
2244 ret = __clk_speculate_rates(child, new_rate);
2245 if (ret & NOTIFY_STOP_MASK)
2246 break;
2247 }
2248
2249out:
2250 return ret;
2251}
2252
2253static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
2254 struct clk_core *new_parent, u8 p_index)
2255{
2256 struct clk_core *child;
2257
2258 core->new_rate = new_rate;
2259 core->new_parent = new_parent;
2260 core->new_parent_index = p_index;
2261 /* include clk in new parent's PRE_RATE_CHANGE notifications */
2262 core->new_child = NULL;
2263 if (new_parent && new_parent != core->parent)
2264 new_parent->new_child = core;
2265
2266 hlist_for_each_entry(child, &core->children, child_node) {
2267 child->new_rate = clk_recalc(child, new_rate);
2268 clk_calc_subtree(child, child->new_rate, NULL, 0);
2269 }
2270}
2271
2272/*
2273 * calculate the new rates returning the topmost clock that has to be
2274 * changed.
2275 */
2276static struct clk_core *clk_calc_new_rates(struct clk_core *core,
2277 unsigned long rate)
2278{
2279 struct clk_core *top = core;
2280 struct clk_core *old_parent, *parent;
2281 unsigned long best_parent_rate = 0;
2282 unsigned long new_rate;
2283 unsigned long min_rate;
2284 unsigned long max_rate;
2285 int p_index = 0;
2286 long ret;
2287
2288 /* sanity */
2289 if (IS_ERR_OR_NULL(core))
2290 return NULL;
2291
2292 /* save parent rate, if it exists */
2293 parent = old_parent = core->parent;
2294 if (parent)
2295 best_parent_rate = parent->rate;
2296
2297 clk_core_get_boundaries(core, &min_rate, &max_rate);
2298
2299 /* find the closest rate and parent clk/rate */
2300 if (clk_core_can_round(core)) {
2301 struct clk_rate_request req;
2302
2303 clk_core_init_rate_req(core, &req, rate);
2304
2305 trace_clk_rate_request_start(&req);
2306
2307 ret = clk_core_determine_round_nolock(core, &req);
2308 if (ret < 0)
2309 return NULL;
2310
2311 trace_clk_rate_request_done(&req);
2312
2313 best_parent_rate = req.best_parent_rate;
2314 new_rate = req.rate;
2315 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
2316
2317 if (new_rate < min_rate || new_rate > max_rate)
2318 return NULL;
2319 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
2320 /* pass-through clock without adjustable parent */
2321 core->new_rate = core->rate;
2322 return NULL;
2323 } else {
2324 /* pass-through clock with adjustable parent */
2325 top = clk_calc_new_rates(parent, rate);
2326 new_rate = parent->new_rate;
2327 goto out;
2328 }
2329
2330 /* some clocks must be gated to change parent */
2331 if (parent != old_parent &&
2332 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
2333 pr_debug("%s: %s not gated but wants to reparent\n",
2334 __func__, core->name);
2335 return NULL;
2336 }
2337
2338 /* try finding the new parent index */
2339 if (parent && core->num_parents > 1) {
2340 p_index = clk_fetch_parent_index(core, parent);
2341 if (p_index < 0) {
2342 pr_debug("%s: clk %s can not be parent of clk %s\n",
2343 __func__, parent->name, core->name);
2344 return NULL;
2345 }
2346 }
2347
2348 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2349 best_parent_rate != parent->rate)
2350 top = clk_calc_new_rates(parent, best_parent_rate);
2351
2352out:
2353 clk_calc_subtree(core, new_rate, parent, p_index);
2354
2355 return top;
2356}
2357
2358/*
2359 * Notify about rate changes in a subtree. Always walk down the whole tree
2360 * so that in case of an error we can walk down the whole tree again and
2361 * abort the change.
2362 */
2363static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2364 unsigned long event)
2365{
2366 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2367 int ret = NOTIFY_DONE;
2368
2369 if (core->rate == core->new_rate)
2370 return NULL;
2371
2372 if (core->notifier_count) {
2373 ret = __clk_notify(core, event, core->rate, core->new_rate);
2374 if (ret & NOTIFY_STOP_MASK)
2375 fail_clk = core;
2376 }
2377
2378 hlist_for_each_entry(child, &core->children, child_node) {
2379 /* Skip children who will be reparented to another clock */
2380 if (child->new_parent && child->new_parent != core)
2381 continue;
2382 tmp_clk = clk_propagate_rate_change(child, event);
2383 if (tmp_clk)
2384 fail_clk = tmp_clk;
2385 }
2386
2387 /* handle the new child who might not be in core->children yet */
2388 if (core->new_child) {
2389 tmp_clk = clk_propagate_rate_change(core->new_child, event);
2390 if (tmp_clk)
2391 fail_clk = tmp_clk;
2392 }
2393
2394 return fail_clk;
2395}
2396
2397/*
2398 * walk down a subtree and set the new rates notifying the rate
2399 * change on the way
2400 */
2401static void clk_change_rate(struct clk_core *core)
2402{
2403 struct clk_core *child;
2404 struct hlist_node *tmp;
2405 unsigned long old_rate;
2406 unsigned long best_parent_rate = 0;
2407 bool skip_set_rate = false;
2408 struct clk_core *old_parent;
2409 struct clk_core *parent = NULL;
2410
2411 old_rate = core->rate;
2412
2413 if (core->new_parent) {
2414 parent = core->new_parent;
2415 best_parent_rate = core->new_parent->rate;
2416 } else if (core->parent) {
2417 parent = core->parent;
2418 best_parent_rate = core->parent->rate;
2419 }
2420
2421 if (clk_pm_runtime_get(core))
2422 return;
2423
2424 if (core->flags & CLK_SET_RATE_UNGATE) {
2425 clk_core_prepare(core);
2426 clk_core_enable_lock(core);
2427 }
2428
2429 if (core->new_parent && core->new_parent != core->parent) {
2430 old_parent = __clk_set_parent_before(core, core->new_parent);
2431 trace_clk_set_parent(core, core->new_parent);
2432
2433 if (core->ops->set_rate_and_parent) {
2434 skip_set_rate = true;
2435 core->ops->set_rate_and_parent(core->hw, core->new_rate,
2436 best_parent_rate,
2437 core->new_parent_index);
2438 } else if (core->ops->set_parent) {
2439 core->ops->set_parent(core->hw, core->new_parent_index);
2440 }
2441
2442 trace_clk_set_parent_complete(core, core->new_parent);
2443 __clk_set_parent_after(core, core->new_parent, old_parent);
2444 }
2445
2446 if (core->flags & CLK_OPS_PARENT_ENABLE)
2447 clk_core_prepare_enable(parent);
2448
2449 trace_clk_set_rate(core, core->new_rate);
2450
2451 if (!skip_set_rate && core->ops->set_rate)
2452 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2453
2454 trace_clk_set_rate_complete(core, core->new_rate);
2455
2456 core->rate = clk_recalc(core, best_parent_rate);
2457
2458 if (core->flags & CLK_SET_RATE_UNGATE) {
2459 clk_core_disable_lock(core);
2460 clk_core_unprepare(core);
2461 }
2462
2463 if (core->flags & CLK_OPS_PARENT_ENABLE)
2464 clk_core_disable_unprepare(parent);
2465
2466 if (core->notifier_count && old_rate != core->rate)
2467 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2468
2469 if (core->flags & CLK_RECALC_NEW_RATES)
2470 (void)clk_calc_new_rates(core, core->new_rate);
2471
2472 /*
2473 * Use safe iteration, as change_rate can actually swap parents
2474 * for certain clock types.
2475 */
2476 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2477 /* Skip children who will be reparented to another clock */
2478 if (child->new_parent && child->new_parent != core)
2479 continue;
2480 clk_change_rate(child);
2481 }
2482
2483 /* handle the new child who might not be in core->children yet */
2484 if (core->new_child)
2485 clk_change_rate(core->new_child);
2486
2487 clk_pm_runtime_put(core);
2488}
2489
2490static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2491 unsigned long req_rate)
2492{
2493 int ret, cnt;
2494 struct clk_rate_request req;
2495
2496 lockdep_assert_held(&prepare_lock);
2497
2498 if (!core)
2499 return 0;
2500
2501 /* simulate what the rate would be if it could be freely set */
2502 cnt = clk_core_rate_nuke_protect(core);
2503 if (cnt < 0)
2504 return cnt;
2505
2506 clk_core_init_rate_req(core, &req, req_rate);
2507
2508 trace_clk_rate_request_start(&req);
2509
2510 ret = clk_core_round_rate_nolock(core, &req);
2511
2512 trace_clk_rate_request_done(&req);
2513
2514 /* restore the protection */
2515 clk_core_rate_restore_protect(core, cnt);
2516
2517 return ret ? 0 : req.rate;
2518}
2519
2520static int clk_core_set_rate_nolock(struct clk_core *core,
2521 unsigned long req_rate)
2522{
2523 struct clk_core *top, *fail_clk;
2524 unsigned long rate;
2525 int ret;
2526
2527 if (!core)
2528 return 0;
2529
2530 rate = clk_core_req_round_rate_nolock(core, req_rate);
2531
2532 /* bail early if nothing to do */
2533 if (rate == clk_core_get_rate_nolock(core))
2534 return 0;
2535
2536 /* fail on a direct rate set of a protected provider */
2537 if (clk_core_rate_is_protected(core))
2538 return -EBUSY;
2539
2540 /* calculate new rates and get the topmost changed clock */
2541 top = clk_calc_new_rates(core, req_rate);
2542 if (!top)
2543 return -EINVAL;
2544
2545 ret = clk_pm_runtime_get(core);
2546 if (ret)
2547 return ret;
2548
2549 /* notify that we are about to change rates */
2550 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2551 if (fail_clk) {
2552 pr_debug("%s: failed to set %s rate\n", __func__,
2553 fail_clk->name);
2554 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2555 ret = -EBUSY;
2556 goto err;
2557 }
2558
2559 /* change the rates */
2560 clk_change_rate(top);
2561
2562 core->req_rate = req_rate;
2563err:
2564 clk_pm_runtime_put(core);
2565
2566 return ret;
2567}
2568
2569/**
2570 * clk_set_rate - specify a new rate for clk
2571 * @clk: the clk whose rate is being changed
2572 * @rate: the new rate for clk
2573 *
2574 * In the simplest case clk_set_rate will only adjust the rate of clk.
2575 *
2576 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2577 * propagate up to clk's parent; whether or not this happens depends on the
2578 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
2579 * after calling .round_rate then upstream parent propagation is ignored. If
2580 * *parent_rate comes back with a new rate for clk's parent then we propagate
2581 * up to clk's parent and set its rate. Upward propagation will continue
2582 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2583 * .round_rate stops requesting changes to clk's parent_rate.
2584 *
2585 * Rate changes are accomplished via tree traversal that also recalculates the
2586 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2587 *
2588 * Returns 0 on success, -EERROR otherwise.
2589 */
2590int clk_set_rate(struct clk *clk, unsigned long rate)
2591{
2592 int ret;
2593
2594 if (!clk)
2595 return 0;
2596
2597 /* prevent racing with updates to the clock topology */
2598 clk_prepare_lock();
2599
2600 if (clk->exclusive_count)
2601 clk_core_rate_unprotect(clk->core);
2602
2603 ret = clk_core_set_rate_nolock(clk->core, rate);
2604
2605 if (clk->exclusive_count)
2606 clk_core_rate_protect(clk->core);
2607
2608 clk_prepare_unlock();
2609
2610 return ret;
2611}
2612EXPORT_SYMBOL_GPL(clk_set_rate);
2613
2614/**
2615 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2616 * @clk: the clk whose rate is being changed
2617 * @rate: the new rate for clk
2618 *
2619 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2620 * within a critical section
2621 *
2622 * This can be used initially to ensure that at least 1 consumer is
2623 * satisfied when several consumers are competing for exclusivity over the
2624 * same clock provider.
2625 *
2626 * The exclusivity is not applied if setting the rate failed.
2627 *
2628 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2629 * clk_rate_exclusive_put().
2630 *
2631 * Returns 0 on success, -EERROR otherwise.
2632 */
2633int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2634{
2635 int ret;
2636
2637 if (!clk)
2638 return 0;
2639
2640 /* prevent racing with updates to the clock topology */
2641 clk_prepare_lock();
2642
2643 /*
2644 * The temporary protection removal is not here, on purpose
2645 * This function is meant to be used instead of clk_rate_protect,
2646 * so before the consumer code path protect the clock provider
2647 */
2648
2649 ret = clk_core_set_rate_nolock(clk->core, rate);
2650 if (!ret) {
2651 clk_core_rate_protect(clk->core);
2652 clk->exclusive_count++;
2653 }
2654
2655 clk_prepare_unlock();
2656
2657 return ret;
2658}
2659EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2660
2661static int clk_set_rate_range_nolock(struct clk *clk,
2662 unsigned long min,
2663 unsigned long max)
2664{
2665 int ret = 0;
2666 unsigned long old_min, old_max, rate;
2667
2668 lockdep_assert_held(&prepare_lock);
2669
2670 if (!clk)
2671 return 0;
2672
2673 trace_clk_set_rate_range(clk->core, min, max);
2674
2675 if (min > max) {
2676 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2677 __func__, clk->core->name, clk->dev_id, clk->con_id,
2678 min, max);
2679 return -EINVAL;
2680 }
2681
2682 if (clk->exclusive_count)
2683 clk_core_rate_unprotect(clk->core);
2684
2685 /* Save the current values in case we need to rollback the change */
2686 old_min = clk->min_rate;
2687 old_max = clk->max_rate;
2688 clk->min_rate = min;
2689 clk->max_rate = max;
2690
2691 if (!clk_core_check_boundaries(clk->core, min, max)) {
2692 ret = -EINVAL;
2693 goto out;
2694 }
2695
2696 rate = clk->core->req_rate;
2697 if (clk->core->flags & CLK_GET_RATE_NOCACHE)
2698 rate = clk_core_get_rate_recalc(clk->core);
2699
2700 /*
2701 * Since the boundaries have been changed, let's give the
2702 * opportunity to the provider to adjust the clock rate based on
2703 * the new boundaries.
2704 *
2705 * We also need to handle the case where the clock is currently
2706 * outside of the boundaries. Clamping the last requested rate
2707 * to the current minimum and maximum will also handle this.
2708 *
2709 * FIXME:
2710 * There is a catch. It may fail for the usual reason (clock
2711 * broken, clock protected, etc) but also because:
2712 * - round_rate() was not favorable and fell on the wrong
2713 * side of the boundary
2714 * - the determine_rate() callback does not really check for
2715 * this corner case when determining the rate
2716 */
2717 rate = clamp(rate, min, max);
2718 ret = clk_core_set_rate_nolock(clk->core, rate);
2719 if (ret) {
2720 /* rollback the changes */
2721 clk->min_rate = old_min;
2722 clk->max_rate = old_max;
2723 }
2724
2725out:
2726 if (clk->exclusive_count)
2727 clk_core_rate_protect(clk->core);
2728
2729 return ret;
2730}
2731
2732/**
2733 * clk_set_rate_range - set a rate range for a clock source
2734 * @clk: clock source
2735 * @min: desired minimum clock rate in Hz, inclusive
2736 * @max: desired maximum clock rate in Hz, inclusive
2737 *
2738 * Return: 0 for success or negative errno on failure.
2739 */
2740int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2741{
2742 int ret;
2743
2744 if (!clk)
2745 return 0;
2746
2747 clk_prepare_lock();
2748
2749 ret = clk_set_rate_range_nolock(clk, min, max);
2750
2751 clk_prepare_unlock();
2752
2753 return ret;
2754}
2755EXPORT_SYMBOL_GPL(clk_set_rate_range);
2756
2757/**
2758 * clk_set_min_rate - set a minimum clock rate for a clock source
2759 * @clk: clock source
2760 * @rate: desired minimum clock rate in Hz, inclusive
2761 *
2762 * Returns success (0) or negative errno.
2763 */
2764int clk_set_min_rate(struct clk *clk, unsigned long rate)
2765{
2766 if (!clk)
2767 return 0;
2768
2769 trace_clk_set_min_rate(clk->core, rate);
2770
2771 return clk_set_rate_range(clk, rate, clk->max_rate);
2772}
2773EXPORT_SYMBOL_GPL(clk_set_min_rate);
2774
2775/**
2776 * clk_set_max_rate - set a maximum clock rate for a clock source
2777 * @clk: clock source
2778 * @rate: desired maximum clock rate in Hz, inclusive
2779 *
2780 * Returns success (0) or negative errno.
2781 */
2782int clk_set_max_rate(struct clk *clk, unsigned long rate)
2783{
2784 if (!clk)
2785 return 0;
2786
2787 trace_clk_set_max_rate(clk->core, rate);
2788
2789 return clk_set_rate_range(clk, clk->min_rate, rate);
2790}
2791EXPORT_SYMBOL_GPL(clk_set_max_rate);
2792
2793/**
2794 * clk_get_parent - return the parent of a clk
2795 * @clk: the clk whose parent gets returned
2796 *
2797 * Simply returns clk->parent. Returns NULL if clk is NULL.
2798 */
2799struct clk *clk_get_parent(struct clk *clk)
2800{
2801 struct clk *parent;
2802
2803 if (!clk)
2804 return NULL;
2805
2806 clk_prepare_lock();
2807 /* TODO: Create a per-user clk and change callers to call clk_put */
2808 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2809 clk_prepare_unlock();
2810
2811 return parent;
2812}
2813EXPORT_SYMBOL_GPL(clk_get_parent);
2814
2815static struct clk_core *__clk_init_parent(struct clk_core *core)
2816{
2817 u8 index = 0;
2818
2819 if (core->num_parents > 1 && core->ops->get_parent)
2820 index = core->ops->get_parent(core->hw);
2821
2822 return clk_core_get_parent_by_index(core, index);
2823}
2824
2825static void clk_core_reparent(struct clk_core *core,
2826 struct clk_core *new_parent)
2827{
2828 clk_reparent(core, new_parent);
2829 __clk_recalc_accuracies(core);
2830 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2831}
2832
2833void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2834{
2835 if (!hw)
2836 return;
2837
2838 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2839}
2840
2841/**
2842 * clk_has_parent - check if a clock is a possible parent for another
2843 * @clk: clock source
2844 * @parent: parent clock source
2845 *
2846 * This function can be used in drivers that need to check that a clock can be
2847 * the parent of another without actually changing the parent.
2848 *
2849 * Returns true if @parent is a possible parent for @clk, false otherwise.
2850 */
2851bool clk_has_parent(const struct clk *clk, const struct clk *parent)
2852{
2853 /* NULL clocks should be nops, so return success if either is NULL. */
2854 if (!clk || !parent)
2855 return true;
2856
2857 return clk_core_has_parent(clk->core, parent->core);
2858}
2859EXPORT_SYMBOL_GPL(clk_has_parent);
2860
2861static int clk_core_set_parent_nolock(struct clk_core *core,
2862 struct clk_core *parent)
2863{
2864 int ret = 0;
2865 int p_index = 0;
2866 unsigned long p_rate = 0;
2867
2868 lockdep_assert_held(&prepare_lock);
2869
2870 if (!core)
2871 return 0;
2872
2873 if (core->parent == parent)
2874 return 0;
2875
2876 /* verify ops for multi-parent clks */
2877 if (core->num_parents > 1 && !core->ops->set_parent)
2878 return -EPERM;
2879
2880 /* check that we are allowed to re-parent if the clock is in use */
2881 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2882 return -EBUSY;
2883
2884 if (clk_core_rate_is_protected(core))
2885 return -EBUSY;
2886
2887 /* try finding the new parent index */
2888 if (parent) {
2889 p_index = clk_fetch_parent_index(core, parent);
2890 if (p_index < 0) {
2891 pr_debug("%s: clk %s can not be parent of clk %s\n",
2892 __func__, parent->name, core->name);
2893 return p_index;
2894 }
2895 p_rate = parent->rate;
2896 }
2897
2898 ret = clk_pm_runtime_get(core);
2899 if (ret)
2900 return ret;
2901
2902 /* propagate PRE_RATE_CHANGE notifications */
2903 ret = __clk_speculate_rates(core, p_rate);
2904
2905 /* abort if a driver objects */
2906 if (ret & NOTIFY_STOP_MASK)
2907 goto runtime_put;
2908
2909 /* do the re-parent */
2910 ret = __clk_set_parent(core, parent, p_index);
2911
2912 /* propagate rate an accuracy recalculation accordingly */
2913 if (ret) {
2914 __clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
2915 } else {
2916 __clk_recalc_rates(core, true, POST_RATE_CHANGE);
2917 __clk_recalc_accuracies(core);
2918 }
2919
2920runtime_put:
2921 clk_pm_runtime_put(core);
2922
2923 return ret;
2924}
2925
2926int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2927{
2928 return clk_core_set_parent_nolock(hw->core, parent->core);
2929}
2930EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2931
2932/**
2933 * clk_set_parent - switch the parent of a mux clk
2934 * @clk: the mux clk whose input we are switching
2935 * @parent: the new input to clk
2936 *
2937 * Re-parent clk to use parent as its new input source. If clk is in
2938 * prepared state, the clk will get enabled for the duration of this call. If
2939 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2940 * that, the reparenting is glitchy in hardware, etc), use the
2941 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2942 *
2943 * After successfully changing clk's parent clk_set_parent will update the
2944 * clk topology, sysfs topology and propagate rate recalculation via
2945 * __clk_recalc_rates.
2946 *
2947 * Returns 0 on success, -EERROR otherwise.
2948 */
2949int clk_set_parent(struct clk *clk, struct clk *parent)
2950{
2951 int ret;
2952
2953 if (!clk)
2954 return 0;
2955
2956 clk_prepare_lock();
2957
2958 if (clk->exclusive_count)
2959 clk_core_rate_unprotect(clk->core);
2960
2961 ret = clk_core_set_parent_nolock(clk->core,
2962 parent ? parent->core : NULL);
2963
2964 if (clk->exclusive_count)
2965 clk_core_rate_protect(clk->core);
2966
2967 clk_prepare_unlock();
2968
2969 return ret;
2970}
2971EXPORT_SYMBOL_GPL(clk_set_parent);
2972
2973static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2974{
2975 int ret = -EINVAL;
2976
2977 lockdep_assert_held(&prepare_lock);
2978
2979 if (!core)
2980 return 0;
2981
2982 if (clk_core_rate_is_protected(core))
2983 return -EBUSY;
2984
2985 trace_clk_set_phase(core, degrees);
2986
2987 if (core->ops->set_phase) {
2988 ret = core->ops->set_phase(core->hw, degrees);
2989 if (!ret)
2990 core->phase = degrees;
2991 }
2992
2993 trace_clk_set_phase_complete(core, degrees);
2994
2995 return ret;
2996}
2997
2998/**
2999 * clk_set_phase - adjust the phase shift of a clock signal
3000 * @clk: clock signal source
3001 * @degrees: number of degrees the signal is shifted
3002 *
3003 * Shifts the phase of a clock signal by the specified
3004 * degrees. Returns 0 on success, -EERROR otherwise.
3005 *
3006 * This function makes no distinction about the input or reference
3007 * signal that we adjust the clock signal phase against. For example
3008 * phase locked-loop clock signal generators we may shift phase with
3009 * respect to feedback clock signal input, but for other cases the
3010 * clock phase may be shifted with respect to some other, unspecified
3011 * signal.
3012 *
3013 * Additionally the concept of phase shift does not propagate through
3014 * the clock tree hierarchy, which sets it apart from clock rates and
3015 * clock accuracy. A parent clock phase attribute does not have an
3016 * impact on the phase attribute of a child clock.
3017 */
3018int clk_set_phase(struct clk *clk, int degrees)
3019{
3020 int ret;
3021
3022 if (!clk)
3023 return 0;
3024
3025 /* sanity check degrees */
3026 degrees %= 360;
3027 if (degrees < 0)
3028 degrees += 360;
3029
3030 clk_prepare_lock();
3031
3032 if (clk->exclusive_count)
3033 clk_core_rate_unprotect(clk->core);
3034
3035 ret = clk_core_set_phase_nolock(clk->core, degrees);
3036
3037 if (clk->exclusive_count)
3038 clk_core_rate_protect(clk->core);
3039
3040 clk_prepare_unlock();
3041
3042 return ret;
3043}
3044EXPORT_SYMBOL_GPL(clk_set_phase);
3045
3046static int clk_core_get_phase(struct clk_core *core)
3047{
3048 int ret;
3049
3050 lockdep_assert_held(&prepare_lock);
3051 if (!core->ops->get_phase)
3052 return 0;
3053
3054 /* Always try to update cached phase if possible */
3055 ret = core->ops->get_phase(core->hw);
3056 if (ret >= 0)
3057 core->phase = ret;
3058
3059 return ret;
3060}
3061
3062/**
3063 * clk_get_phase - return the phase shift of a clock signal
3064 * @clk: clock signal source
3065 *
3066 * Returns the phase shift of a clock node in degrees, otherwise returns
3067 * -EERROR.
3068 */
3069int clk_get_phase(struct clk *clk)
3070{
3071 int ret;
3072
3073 if (!clk)
3074 return 0;
3075
3076 clk_prepare_lock();
3077 ret = clk_core_get_phase(clk->core);
3078 clk_prepare_unlock();
3079
3080 return ret;
3081}
3082EXPORT_SYMBOL_GPL(clk_get_phase);
3083
3084static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
3085{
3086 /* Assume a default value of 50% */
3087 core->duty.num = 1;
3088 core->duty.den = 2;
3089}
3090
3091static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
3092
3093static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
3094{
3095 struct clk_duty *duty = &core->duty;
3096 int ret = 0;
3097
3098 if (!core->ops->get_duty_cycle)
3099 return clk_core_update_duty_cycle_parent_nolock(core);
3100
3101 ret = core->ops->get_duty_cycle(core->hw, duty);
3102 if (ret)
3103 goto reset;
3104
3105 /* Don't trust the clock provider too much */
3106 if (duty->den == 0 || duty->num > duty->den) {
3107 ret = -EINVAL;
3108 goto reset;
3109 }
3110
3111 return 0;
3112
3113reset:
3114 clk_core_reset_duty_cycle_nolock(core);
3115 return ret;
3116}
3117
3118static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
3119{
3120 int ret = 0;
3121
3122 if (core->parent &&
3123 core->flags & CLK_DUTY_CYCLE_PARENT) {
3124 ret = clk_core_update_duty_cycle_nolock(core->parent);
3125 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3126 } else {
3127 clk_core_reset_duty_cycle_nolock(core);
3128 }
3129
3130 return ret;
3131}
3132
3133static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3134 struct clk_duty *duty);
3135
3136static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
3137 struct clk_duty *duty)
3138{
3139 int ret;
3140
3141 lockdep_assert_held(&prepare_lock);
3142
3143 if (clk_core_rate_is_protected(core))
3144 return -EBUSY;
3145
3146 trace_clk_set_duty_cycle(core, duty);
3147
3148 if (!core->ops->set_duty_cycle)
3149 return clk_core_set_duty_cycle_parent_nolock(core, duty);
3150
3151 ret = core->ops->set_duty_cycle(core->hw, duty);
3152 if (!ret)
3153 memcpy(&core->duty, duty, sizeof(*duty));
3154
3155 trace_clk_set_duty_cycle_complete(core, duty);
3156
3157 return ret;
3158}
3159
3160static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3161 struct clk_duty *duty)
3162{
3163 int ret = 0;
3164
3165 if (core->parent &&
3166 core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
3167 ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
3168 memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3169 }
3170
3171 return ret;
3172}
3173
3174/**
3175 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
3176 * @clk: clock signal source
3177 * @num: numerator of the duty cycle ratio to be applied
3178 * @den: denominator of the duty cycle ratio to be applied
3179 *
3180 * Apply the duty cycle ratio if the ratio is valid and the clock can
3181 * perform this operation
3182 *
3183 * Returns (0) on success, a negative errno otherwise.
3184 */
3185int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
3186{
3187 int ret;
3188 struct clk_duty duty;
3189
3190 if (!clk)
3191 return 0;
3192
3193 /* sanity check the ratio */
3194 if (den == 0 || num > den)
3195 return -EINVAL;
3196
3197 duty.num = num;
3198 duty.den = den;
3199
3200 clk_prepare_lock();
3201
3202 if (clk->exclusive_count)
3203 clk_core_rate_unprotect(clk->core);
3204
3205 ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
3206
3207 if (clk->exclusive_count)
3208 clk_core_rate_protect(clk->core);
3209
3210 clk_prepare_unlock();
3211
3212 return ret;
3213}
3214EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
3215
3216static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
3217 unsigned int scale)
3218{
3219 struct clk_duty *duty = &core->duty;
3220 int ret;
3221
3222 clk_prepare_lock();
3223
3224 ret = clk_core_update_duty_cycle_nolock(core);
3225 if (!ret)
3226 ret = mult_frac(scale, duty->num, duty->den);
3227
3228 clk_prepare_unlock();
3229
3230 return ret;
3231}
3232
3233/**
3234 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
3235 * @clk: clock signal source
3236 * @scale: scaling factor to be applied to represent the ratio as an integer
3237 *
3238 * Returns the duty cycle ratio of a clock node multiplied by the provided
3239 * scaling factor, or negative errno on error.
3240 */
3241int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
3242{
3243 if (!clk)
3244 return 0;
3245
3246 return clk_core_get_scaled_duty_cycle(clk->core, scale);
3247}
3248EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
3249
3250/**
3251 * clk_is_match - check if two clk's point to the same hardware clock
3252 * @p: clk compared against q
3253 * @q: clk compared against p
3254 *
3255 * Returns true if the two struct clk pointers both point to the same hardware
3256 * clock node. Put differently, returns true if struct clk *p and struct clk *q
3257 * share the same struct clk_core object.
3258 *
3259 * Returns false otherwise. Note that two NULL clks are treated as matching.
3260 */
3261bool clk_is_match(const struct clk *p, const struct clk *q)
3262{
3263 /* trivial case: identical struct clk's or both NULL */
3264 if (p == q)
3265 return true;
3266
3267 /* true if clk->core pointers match. Avoid dereferencing garbage */
3268 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
3269 if (p->core == q->core)
3270 return true;
3271
3272 return false;
3273}
3274EXPORT_SYMBOL_GPL(clk_is_match);
3275
3276/*** debugfs support ***/
3277
3278#ifdef CONFIG_DEBUG_FS
3279#include <linux/debugfs.h>
3280
3281static struct dentry *rootdir;
3282static int inited = 0;
3283static DEFINE_MUTEX(clk_debug_lock);
3284static HLIST_HEAD(clk_debug_list);
3285
3286static struct hlist_head *orphan_list[] = {
3287 &clk_orphan_list,
3288 NULL,
3289};
3290
3291static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
3292 int level)
3293{
3294 int phase;
3295 struct clk *clk_user;
3296 int multi_node = 0;
3297
3298 seq_printf(s, "%*s%-*s %-7d %-8d %-8d %-11lu %-10lu ",
3299 level * 3 + 1, "",
3300 35 - level * 3, c->name,
3301 c->enable_count, c->prepare_count, c->protect_count,
3302 clk_core_get_rate_recalc(c),
3303 clk_core_get_accuracy_recalc(c));
3304
3305 phase = clk_core_get_phase(c);
3306 if (phase >= 0)
3307 seq_printf(s, "%-5d", phase);
3308 else
3309 seq_puts(s, "-----");
3310
3311 seq_printf(s, " %-6d", clk_core_get_scaled_duty_cycle(c, 100000));
3312
3313 if (c->ops->is_enabled)
3314 seq_printf(s, " %5c ", clk_core_is_enabled(c) ? 'Y' : 'N');
3315 else if (!c->ops->enable)
3316 seq_printf(s, " %5c ", 'Y');
3317 else
3318 seq_printf(s, " %5c ", '?');
3319
3320 hlist_for_each_entry(clk_user, &c->clks, clks_node) {
3321 seq_printf(s, "%*s%-*s %-25s\n",
3322 level * 3 + 2 + 105 * multi_node, "",
3323 30,
3324 clk_user->dev_id ? clk_user->dev_id : "deviceless",
3325 clk_user->con_id ? clk_user->con_id : "no_connection_id");
3326
3327 multi_node = 1;
3328 }
3329
3330}
3331
3332static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
3333 int level)
3334{
3335 struct clk_core *child;
3336
3337 clk_summary_show_one(s, c, level);
3338
3339 hlist_for_each_entry(child, &c->children, child_node)
3340 clk_summary_show_subtree(s, child, level + 1);
3341}
3342
3343static int clk_summary_show(struct seq_file *s, void *data)
3344{
3345 struct clk_core *c;
3346 struct hlist_head **lists = s->private;
3347 int ret;
3348
3349 seq_puts(s, " enable prepare protect duty hardware connection\n");
3350 seq_puts(s, " clock count count count rate accuracy phase cycle enable consumer id\n");
3351 seq_puts(s, "---------------------------------------------------------------------------------------------------------------------------------------------\n");
3352
3353 ret = clk_pm_runtime_get_all();
3354 if (ret)
3355 return ret;
3356
3357 clk_prepare_lock();
3358
3359 for (; *lists; lists++)
3360 hlist_for_each_entry(c, *lists, child_node)
3361 clk_summary_show_subtree(s, c, 0);
3362
3363 clk_prepare_unlock();
3364 clk_pm_runtime_put_all();
3365
3366 return 0;
3367}
3368DEFINE_SHOW_ATTRIBUTE(clk_summary);
3369
3370static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
3371{
3372 int phase;
3373 unsigned long min_rate, max_rate;
3374
3375 clk_core_get_boundaries(c, &min_rate, &max_rate);
3376
3377 /* This should be JSON format, i.e. elements separated with a comma */
3378 seq_printf(s, "\"%s\": { ", c->name);
3379 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3380 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3381 seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3382 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3383 seq_printf(s, "\"min_rate\": %lu,", min_rate);
3384 seq_printf(s, "\"max_rate\": %lu,", max_rate);
3385 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3386 phase = clk_core_get_phase(c);
3387 if (phase >= 0)
3388 seq_printf(s, "\"phase\": %d,", phase);
3389 seq_printf(s, "\"duty_cycle\": %u",
3390 clk_core_get_scaled_duty_cycle(c, 100000));
3391}
3392
3393static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3394{
3395 struct clk_core *child;
3396
3397 clk_dump_one(s, c, level);
3398
3399 hlist_for_each_entry(child, &c->children, child_node) {
3400 seq_putc(s, ',');
3401 clk_dump_subtree(s, child, level + 1);
3402 }
3403
3404 seq_putc(s, '}');
3405}
3406
3407static int clk_dump_show(struct seq_file *s, void *data)
3408{
3409 struct clk_core *c;
3410 bool first_node = true;
3411 struct hlist_head **lists = s->private;
3412 int ret;
3413
3414 ret = clk_pm_runtime_get_all();
3415 if (ret)
3416 return ret;
3417
3418 seq_putc(s, '{');
3419
3420 clk_prepare_lock();
3421
3422 for (; *lists; lists++) {
3423 hlist_for_each_entry(c, *lists, child_node) {
3424 if (!first_node)
3425 seq_putc(s, ',');
3426 first_node = false;
3427 clk_dump_subtree(s, c, 0);
3428 }
3429 }
3430
3431 clk_prepare_unlock();
3432 clk_pm_runtime_put_all();
3433
3434 seq_puts(s, "}\n");
3435 return 0;
3436}
3437DEFINE_SHOW_ATTRIBUTE(clk_dump);
3438
3439#undef CLOCK_ALLOW_WRITE_DEBUGFS
3440#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3441/*
3442 * This can be dangerous, therefore don't provide any real compile time
3443 * configuration option for this feature.
3444 * People who want to use this will need to modify the source code directly.
3445 */
3446static int clk_rate_set(void *data, u64 val)
3447{
3448 struct clk_core *core = data;
3449 int ret;
3450
3451 clk_prepare_lock();
3452 ret = clk_core_set_rate_nolock(core, val);
3453 clk_prepare_unlock();
3454
3455 return ret;
3456}
3457
3458#define clk_rate_mode 0644
3459
3460static int clk_phase_set(void *data, u64 val)
3461{
3462 struct clk_core *core = data;
3463 int degrees = do_div(val, 360);
3464 int ret;
3465
3466 clk_prepare_lock();
3467 ret = clk_core_set_phase_nolock(core, degrees);
3468 clk_prepare_unlock();
3469
3470 return ret;
3471}
3472
3473#define clk_phase_mode 0644
3474
3475static int clk_prepare_enable_set(void *data, u64 val)
3476{
3477 struct clk_core *core = data;
3478 int ret = 0;
3479
3480 if (val)
3481 ret = clk_prepare_enable(core->hw->clk);
3482 else
3483 clk_disable_unprepare(core->hw->clk);
3484
3485 return ret;
3486}
3487
3488static int clk_prepare_enable_get(void *data, u64 *val)
3489{
3490 struct clk_core *core = data;
3491
3492 *val = core->enable_count && core->prepare_count;
3493 return 0;
3494}
3495
3496DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3497 clk_prepare_enable_set, "%llu\n");
3498
3499#else
3500#define clk_rate_set NULL
3501#define clk_rate_mode 0444
3502
3503#define clk_phase_set NULL
3504#define clk_phase_mode 0644
3505#endif
3506
3507static int clk_rate_get(void *data, u64 *val)
3508{
3509 struct clk_core *core = data;
3510
3511 clk_prepare_lock();
3512 *val = clk_core_get_rate_recalc(core);
3513 clk_prepare_unlock();
3514
3515 return 0;
3516}
3517
3518DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3519
3520static int clk_phase_get(void *data, u64 *val)
3521{
3522 struct clk_core *core = data;
3523
3524 *val = core->phase;
3525 return 0;
3526}
3527
3528DEFINE_DEBUGFS_ATTRIBUTE(clk_phase_fops, clk_phase_get, clk_phase_set, "%llu\n");
3529
3530static const struct {
3531 unsigned long flag;
3532 const char *name;
3533} clk_flags[] = {
3534#define ENTRY(f) { f, #f }
3535 ENTRY(CLK_SET_RATE_GATE),
3536 ENTRY(CLK_SET_PARENT_GATE),
3537 ENTRY(CLK_SET_RATE_PARENT),
3538 ENTRY(CLK_IGNORE_UNUSED),
3539 ENTRY(CLK_GET_RATE_NOCACHE),
3540 ENTRY(CLK_SET_RATE_NO_REPARENT),
3541 ENTRY(CLK_GET_ACCURACY_NOCACHE),
3542 ENTRY(CLK_RECALC_NEW_RATES),
3543 ENTRY(CLK_SET_RATE_UNGATE),
3544 ENTRY(CLK_IS_CRITICAL),
3545 ENTRY(CLK_OPS_PARENT_ENABLE),
3546 ENTRY(CLK_DUTY_CYCLE_PARENT),
3547#undef ENTRY
3548};
3549
3550static int clk_flags_show(struct seq_file *s, void *data)
3551{
3552 struct clk_core *core = s->private;
3553 unsigned long flags = core->flags;
3554 unsigned int i;
3555
3556 for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3557 if (flags & clk_flags[i].flag) {
3558 seq_printf(s, "%s\n", clk_flags[i].name);
3559 flags &= ~clk_flags[i].flag;
3560 }
3561 }
3562 if (flags) {
3563 /* Unknown flags */
3564 seq_printf(s, "0x%lx\n", flags);
3565 }
3566
3567 return 0;
3568}
3569DEFINE_SHOW_ATTRIBUTE(clk_flags);
3570
3571static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3572 unsigned int i, char terminator)
3573{
3574 struct clk_core *parent;
3575 const char *name = NULL;
3576
3577 /*
3578 * Go through the following options to fetch a parent's name.
3579 *
3580 * 1. Fetch the registered parent clock and use its name
3581 * 2. Use the global (fallback) name if specified
3582 * 3. Use the local fw_name if provided
3583 * 4. Fetch parent clock's clock-output-name if DT index was set
3584 *
3585 * This may still fail in some cases, such as when the parent is
3586 * specified directly via a struct clk_hw pointer, but it isn't
3587 * registered (yet).
3588 */
3589 parent = clk_core_get_parent_by_index(core, i);
3590 if (parent) {
3591 seq_puts(s, parent->name);
3592 } else if (core->parents[i].name) {
3593 seq_puts(s, core->parents[i].name);
3594 } else if (core->parents[i].fw_name) {
3595 seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3596 } else {
3597 if (core->parents[i].index >= 0)
3598 name = of_clk_get_parent_name(core->of_node, core->parents[i].index);
3599 if (!name)
3600 name = "(missing)";
3601
3602 seq_puts(s, name);
3603 }
3604
3605 seq_putc(s, terminator);
3606}
3607
3608static int possible_parents_show(struct seq_file *s, void *data)
3609{
3610 struct clk_core *core = s->private;
3611 int i;
3612
3613 for (i = 0; i < core->num_parents - 1; i++)
3614 possible_parent_show(s, core, i, ' ');
3615
3616 possible_parent_show(s, core, i, '\n');
3617
3618 return 0;
3619}
3620DEFINE_SHOW_ATTRIBUTE(possible_parents);
3621
3622static int current_parent_show(struct seq_file *s, void *data)
3623{
3624 struct clk_core *core = s->private;
3625
3626 if (core->parent)
3627 seq_printf(s, "%s\n", core->parent->name);
3628
3629 return 0;
3630}
3631DEFINE_SHOW_ATTRIBUTE(current_parent);
3632
3633#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3634static ssize_t current_parent_write(struct file *file, const char __user *ubuf,
3635 size_t count, loff_t *ppos)
3636{
3637 struct seq_file *s = file->private_data;
3638 struct clk_core *core = s->private;
3639 struct clk_core *parent;
3640 u8 idx;
3641 int err;
3642
3643 err = kstrtou8_from_user(ubuf, count, 0, &idx);
3644 if (err < 0)
3645 return err;
3646
3647 parent = clk_core_get_parent_by_index(core, idx);
3648 if (!parent)
3649 return -ENOENT;
3650
3651 clk_prepare_lock();
3652 err = clk_core_set_parent_nolock(core, parent);
3653 clk_prepare_unlock();
3654 if (err)
3655 return err;
3656
3657 return count;
3658}
3659
3660static const struct file_operations current_parent_rw_fops = {
3661 .open = current_parent_open,
3662 .write = current_parent_write,
3663 .read = seq_read,
3664 .llseek = seq_lseek,
3665 .release = single_release,
3666};
3667#endif
3668
3669static int clk_duty_cycle_show(struct seq_file *s, void *data)
3670{
3671 struct clk_core *core = s->private;
3672 struct clk_duty *duty = &core->duty;
3673
3674 seq_printf(s, "%u/%u\n", duty->num, duty->den);
3675
3676 return 0;
3677}
3678DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3679
3680static int clk_min_rate_show(struct seq_file *s, void *data)
3681{
3682 struct clk_core *core = s->private;
3683 unsigned long min_rate, max_rate;
3684
3685 clk_prepare_lock();
3686 clk_core_get_boundaries(core, &min_rate, &max_rate);
3687 clk_prepare_unlock();
3688 seq_printf(s, "%lu\n", min_rate);
3689
3690 return 0;
3691}
3692DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3693
3694static int clk_max_rate_show(struct seq_file *s, void *data)
3695{
3696 struct clk_core *core = s->private;
3697 unsigned long min_rate, max_rate;
3698
3699 clk_prepare_lock();
3700 clk_core_get_boundaries(core, &min_rate, &max_rate);
3701 clk_prepare_unlock();
3702 seq_printf(s, "%lu\n", max_rate);
3703
3704 return 0;
3705}
3706DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3707
3708static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3709{
3710 struct dentry *root;
3711
3712 if (!core || !pdentry)
3713 return;
3714
3715 root = debugfs_create_dir(core->name, pdentry);
3716 core->dentry = root;
3717
3718 debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3719 &clk_rate_fops);
3720 debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3721 debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3722 debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3723 debugfs_create_file("clk_phase", clk_phase_mode, root, core,
3724 &clk_phase_fops);
3725 debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3726 debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3727 debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3728 debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3729 debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3730 debugfs_create_file("clk_duty_cycle", 0444, root, core,
3731 &clk_duty_cycle_fops);
3732#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3733 debugfs_create_file("clk_prepare_enable", 0644, root, core,
3734 &clk_prepare_enable_fops);
3735
3736 if (core->num_parents > 1)
3737 debugfs_create_file("clk_parent", 0644, root, core,
3738 ¤t_parent_rw_fops);
3739 else
3740#endif
3741 if (core->num_parents > 0)
3742 debugfs_create_file("clk_parent", 0444, root, core,
3743 ¤t_parent_fops);
3744
3745 if (core->num_parents > 1)
3746 debugfs_create_file("clk_possible_parents", 0444, root, core,
3747 &possible_parents_fops);
3748
3749 if (core->ops->debug_init)
3750 core->ops->debug_init(core->hw, core->dentry);
3751}
3752
3753/**
3754 * clk_debug_register - add a clk node to the debugfs clk directory
3755 * @core: the clk being added to the debugfs clk directory
3756 *
3757 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3758 * initialized. Otherwise it bails out early since the debugfs clk directory
3759 * will be created lazily by clk_debug_init as part of a late_initcall.
3760 */
3761static void clk_debug_register(struct clk_core *core)
3762{
3763 mutex_lock(&clk_debug_lock);
3764 hlist_add_head(&core->debug_node, &clk_debug_list);
3765 if (inited)
3766 clk_debug_create_one(core, rootdir);
3767 mutex_unlock(&clk_debug_lock);
3768}
3769
3770 /**
3771 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3772 * @core: the clk being removed from the debugfs clk directory
3773 *
3774 * Dynamically removes a clk and all its child nodes from the
3775 * debugfs clk directory if clk->dentry points to debugfs created by
3776 * clk_debug_register in __clk_core_init.
3777 */
3778static void clk_debug_unregister(struct clk_core *core)
3779{
3780 mutex_lock(&clk_debug_lock);
3781 hlist_del_init(&core->debug_node);
3782 debugfs_remove_recursive(core->dentry);
3783 core->dentry = NULL;
3784 mutex_unlock(&clk_debug_lock);
3785}
3786
3787/**
3788 * clk_debug_init - lazily populate the debugfs clk directory
3789 *
3790 * clks are often initialized very early during boot before memory can be
3791 * dynamically allocated and well before debugfs is setup. This function
3792 * populates the debugfs clk directory once at boot-time when we know that
3793 * debugfs is setup. It should only be called once at boot-time, all other clks
3794 * added dynamically will be done so with clk_debug_register.
3795 */
3796static int __init clk_debug_init(void)
3797{
3798 struct clk_core *core;
3799
3800#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3801 pr_warn("\n");
3802 pr_warn("********************************************************************\n");
3803 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3804 pr_warn("** **\n");
3805 pr_warn("** WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
3806 pr_warn("** **\n");
3807 pr_warn("** This means that this kernel is built to expose clk operations **\n");
3808 pr_warn("** such as parent or rate setting, enabling, disabling, etc. **\n");
3809 pr_warn("** to userspace, which may compromise security on your system. **\n");
3810 pr_warn("** **\n");
3811 pr_warn("** If you see this message and you are not debugging the **\n");
3812 pr_warn("** kernel, report this immediately to your vendor! **\n");
3813 pr_warn("** **\n");
3814 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
3815 pr_warn("********************************************************************\n");
3816#endif
3817
3818 rootdir = debugfs_create_dir("clk", NULL);
3819
3820 debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3821 &clk_summary_fops);
3822 debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3823 &clk_dump_fops);
3824 debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3825 &clk_summary_fops);
3826 debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3827 &clk_dump_fops);
3828
3829 mutex_lock(&clk_debug_lock);
3830 hlist_for_each_entry(core, &clk_debug_list, debug_node)
3831 clk_debug_create_one(core, rootdir);
3832
3833 inited = 1;
3834 mutex_unlock(&clk_debug_lock);
3835
3836 return 0;
3837}
3838late_initcall(clk_debug_init);
3839#else
3840static inline void clk_debug_register(struct clk_core *core) { }
3841static inline void clk_debug_unregister(struct clk_core *core)
3842{
3843}
3844#endif
3845
3846static void clk_core_reparent_orphans_nolock(void)
3847{
3848 struct clk_core *orphan;
3849 struct hlist_node *tmp2;
3850
3851 /*
3852 * walk the list of orphan clocks and reparent any that newly finds a
3853 * parent.
3854 */
3855 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3856 struct clk_core *parent = __clk_init_parent(orphan);
3857
3858 /*
3859 * We need to use __clk_set_parent_before() and _after() to
3860 * properly migrate any prepare/enable count of the orphan
3861 * clock. This is important for CLK_IS_CRITICAL clocks, which
3862 * are enabled during init but might not have a parent yet.
3863 */
3864 if (parent) {
3865 /* update the clk tree topology */
3866 __clk_set_parent_before(orphan, parent);
3867 __clk_set_parent_after(orphan, parent, NULL);
3868 __clk_recalc_accuracies(orphan);
3869 __clk_recalc_rates(orphan, true, 0);
3870
3871 /*
3872 * __clk_init_parent() will set the initial req_rate to
3873 * 0 if the clock doesn't have clk_ops::recalc_rate and
3874 * is an orphan when it's registered.
3875 *
3876 * 'req_rate' is used by clk_set_rate_range() and
3877 * clk_put() to trigger a clk_set_rate() call whenever
3878 * the boundaries are modified. Let's make sure
3879 * 'req_rate' is set to something non-zero so that
3880 * clk_set_rate_range() doesn't drop the frequency.
3881 */
3882 orphan->req_rate = orphan->rate;
3883 }
3884 }
3885}
3886
3887/**
3888 * __clk_core_init - initialize the data structures in a struct clk_core
3889 * @core: clk_core being initialized
3890 *
3891 * Initializes the lists in struct clk_core, queries the hardware for the
3892 * parent and rate and sets them both.
3893 */
3894static int __clk_core_init(struct clk_core *core)
3895{
3896 int ret;
3897 struct clk_core *parent;
3898 unsigned long rate;
3899 int phase;
3900
3901 clk_prepare_lock();
3902
3903 /*
3904 * Set hw->core after grabbing the prepare_lock to synchronize with
3905 * callers of clk_core_fill_parent_index() where we treat hw->core
3906 * being NULL as the clk not being registered yet. This is crucial so
3907 * that clks aren't parented until their parent is fully registered.
3908 */
3909 core->hw->core = core;
3910
3911 ret = clk_pm_runtime_get(core);
3912 if (ret)
3913 goto unlock;
3914
3915 /* check to see if a clock with this name is already registered */
3916 if (clk_core_lookup(core->name)) {
3917 pr_debug("%s: clk %s already initialized\n",
3918 __func__, core->name);
3919 ret = -EEXIST;
3920 goto out;
3921 }
3922
3923 /* check that clk_ops are sane. See Documentation/driver-api/clk.rst */
3924 if (core->ops->set_rate &&
3925 !((core->ops->round_rate || core->ops->determine_rate) &&
3926 core->ops->recalc_rate)) {
3927 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3928 __func__, core->name);
3929 ret = -EINVAL;
3930 goto out;
3931 }
3932
3933 if (core->ops->set_parent && !core->ops->get_parent) {
3934 pr_err("%s: %s must implement .get_parent & .set_parent\n",
3935 __func__, core->name);
3936 ret = -EINVAL;
3937 goto out;
3938 }
3939
3940 if (core->ops->set_parent && !core->ops->determine_rate) {
3941 pr_err("%s: %s must implement .set_parent & .determine_rate\n",
3942 __func__, core->name);
3943 ret = -EINVAL;
3944 goto out;
3945 }
3946
3947 if (core->num_parents > 1 && !core->ops->get_parent) {
3948 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3949 __func__, core->name);
3950 ret = -EINVAL;
3951 goto out;
3952 }
3953
3954 if (core->ops->set_rate_and_parent &&
3955 !(core->ops->set_parent && core->ops->set_rate)) {
3956 pr_err("%s: %s must implement .set_parent & .set_rate\n",
3957 __func__, core->name);
3958 ret = -EINVAL;
3959 goto out;
3960 }
3961
3962 /*
3963 * optional platform-specific magic
3964 *
3965 * The .init callback is not used by any of the basic clock types, but
3966 * exists for weird hardware that must perform initialization magic for
3967 * CCF to get an accurate view of clock for any other callbacks. It may
3968 * also be used needs to perform dynamic allocations. Such allocation
3969 * must be freed in the terminate() callback.
3970 * This callback shall not be used to initialize the parameters state,
3971 * such as rate, parent, etc ...
3972 *
3973 * If it exist, this callback should called before any other callback of
3974 * the clock
3975 */
3976 if (core->ops->init) {
3977 ret = core->ops->init(core->hw);
3978 if (ret)
3979 goto out;
3980 }
3981
3982 parent = core->parent = __clk_init_parent(core);
3983
3984 /*
3985 * Populate core->parent if parent has already been clk_core_init'd. If
3986 * parent has not yet been clk_core_init'd then place clk in the orphan
3987 * list. If clk doesn't have any parents then place it in the root
3988 * clk list.
3989 *
3990 * Every time a new clk is clk_init'd then we walk the list of orphan
3991 * clocks and re-parent any that are children of the clock currently
3992 * being clk_init'd.
3993 */
3994 if (parent) {
3995 hlist_add_head(&core->child_node, &parent->children);
3996 core->orphan = parent->orphan;
3997 } else if (!core->num_parents) {
3998 hlist_add_head(&core->child_node, &clk_root_list);
3999 core->orphan = false;
4000 } else {
4001 hlist_add_head(&core->child_node, &clk_orphan_list);
4002 core->orphan = true;
4003 }
4004
4005 /*
4006 * Set clk's accuracy. The preferred method is to use
4007 * .recalc_accuracy. For simple clocks and lazy developers the default
4008 * fallback is to use the parent's accuracy. If a clock doesn't have a
4009 * parent (or is orphaned) then accuracy is set to zero (perfect
4010 * clock).
4011 */
4012 if (core->ops->recalc_accuracy)
4013 core->accuracy = core->ops->recalc_accuracy(core->hw,
4014 clk_core_get_accuracy_no_lock(parent));
4015 else if (parent)
4016 core->accuracy = parent->accuracy;
4017 else
4018 core->accuracy = 0;
4019
4020 /*
4021 * Set clk's phase by clk_core_get_phase() caching the phase.
4022 * Since a phase is by definition relative to its parent, just
4023 * query the current clock phase, or just assume it's in phase.
4024 */
4025 phase = clk_core_get_phase(core);
4026 if (phase < 0) {
4027 ret = phase;
4028 pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
4029 core->name);
4030 goto out;
4031 }
4032
4033 /*
4034 * Set clk's duty cycle.
4035 */
4036 clk_core_update_duty_cycle_nolock(core);
4037
4038 /*
4039 * Set clk's rate. The preferred method is to use .recalc_rate. For
4040 * simple clocks and lazy developers the default fallback is to use the
4041 * parent's rate. If a clock doesn't have a parent (or is orphaned)
4042 * then rate is set to zero.
4043 */
4044 if (core->ops->recalc_rate)
4045 rate = core->ops->recalc_rate(core->hw,
4046 clk_core_get_rate_nolock(parent));
4047 else if (parent)
4048 rate = parent->rate;
4049 else
4050 rate = 0;
4051 core->rate = core->req_rate = rate;
4052
4053 /*
4054 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
4055 * don't get accidentally disabled when walking the orphan tree and
4056 * reparenting clocks
4057 */
4058 if (core->flags & CLK_IS_CRITICAL) {
4059 ret = clk_core_prepare(core);
4060 if (ret) {
4061 pr_warn("%s: critical clk '%s' failed to prepare\n",
4062 __func__, core->name);
4063 goto out;
4064 }
4065
4066 ret = clk_core_enable_lock(core);
4067 if (ret) {
4068 pr_warn("%s: critical clk '%s' failed to enable\n",
4069 __func__, core->name);
4070 clk_core_unprepare(core);
4071 goto out;
4072 }
4073 }
4074
4075 clk_core_reparent_orphans_nolock();
4076out:
4077 clk_pm_runtime_put(core);
4078unlock:
4079 if (ret) {
4080 hlist_del_init(&core->child_node);
4081 core->hw->core = NULL;
4082 }
4083
4084 clk_prepare_unlock();
4085
4086 if (!ret)
4087 clk_debug_register(core);
4088
4089 return ret;
4090}
4091
4092/**
4093 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
4094 * @core: clk to add consumer to
4095 * @clk: consumer to link to a clk
4096 */
4097static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
4098{
4099 clk_prepare_lock();
4100 hlist_add_head(&clk->clks_node, &core->clks);
4101 clk_prepare_unlock();
4102}
4103
4104/**
4105 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
4106 * @clk: consumer to unlink
4107 */
4108static void clk_core_unlink_consumer(struct clk *clk)
4109{
4110 lockdep_assert_held(&prepare_lock);
4111 hlist_del(&clk->clks_node);
4112}
4113
4114/**
4115 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
4116 * @core: clk to allocate a consumer for
4117 * @dev_id: string describing device name
4118 * @con_id: connection ID string on device
4119 *
4120 * Returns: clk consumer left unlinked from the consumer list
4121 */
4122static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
4123 const char *con_id)
4124{
4125 struct clk *clk;
4126
4127 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
4128 if (!clk)
4129 return ERR_PTR(-ENOMEM);
4130
4131 clk->core = core;
4132 clk->dev_id = dev_id;
4133 clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
4134 clk->max_rate = ULONG_MAX;
4135
4136 return clk;
4137}
4138
4139/**
4140 * free_clk - Free a clk consumer
4141 * @clk: clk consumer to free
4142 *
4143 * Note, this assumes the clk has been unlinked from the clk_core consumer
4144 * list.
4145 */
4146static void free_clk(struct clk *clk)
4147{
4148 kfree_const(clk->con_id);
4149 kfree(clk);
4150}
4151
4152/**
4153 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
4154 * a clk_hw
4155 * @dev: clk consumer device
4156 * @hw: clk_hw associated with the clk being consumed
4157 * @dev_id: string describing device name
4158 * @con_id: connection ID string on device
4159 *
4160 * This is the main function used to create a clk pointer for use by clk
4161 * consumers. It connects a consumer to the clk_core and clk_hw structures
4162 * used by the framework and clk provider respectively.
4163 */
4164struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
4165 const char *dev_id, const char *con_id)
4166{
4167 struct clk *clk;
4168 struct clk_core *core;
4169
4170 /* This is to allow this function to be chained to others */
4171 if (IS_ERR_OR_NULL(hw))
4172 return ERR_CAST(hw);
4173
4174 core = hw->core;
4175 clk = alloc_clk(core, dev_id, con_id);
4176 if (IS_ERR(clk))
4177 return clk;
4178 clk->dev = dev;
4179
4180 if (!try_module_get(core->owner)) {
4181 free_clk(clk);
4182 return ERR_PTR(-ENOENT);
4183 }
4184
4185 kref_get(&core->ref);
4186 clk_core_link_consumer(core, clk);
4187
4188 return clk;
4189}
4190
4191/**
4192 * clk_hw_get_clk - get clk consumer given an clk_hw
4193 * @hw: clk_hw associated with the clk being consumed
4194 * @con_id: connection ID string on device
4195 *
4196 * Returns: new clk consumer
4197 * This is the function to be used by providers which need
4198 * to get a consumer clk and act on the clock element
4199 * Calls to this function must be balanced with calls clk_put()
4200 */
4201struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
4202{
4203 struct device *dev = hw->core->dev;
4204 const char *name = dev ? dev_name(dev) : NULL;
4205
4206 return clk_hw_create_clk(dev, hw, name, con_id);
4207}
4208EXPORT_SYMBOL(clk_hw_get_clk);
4209
4210static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
4211{
4212 const char *dst;
4213
4214 if (!src) {
4215 if (must_exist)
4216 return -EINVAL;
4217 return 0;
4218 }
4219
4220 *dst_p = dst = kstrdup_const(src, GFP_KERNEL);
4221 if (!dst)
4222 return -ENOMEM;
4223
4224 return 0;
4225}
4226
4227static int clk_core_populate_parent_map(struct clk_core *core,
4228 const struct clk_init_data *init)
4229{
4230 u8 num_parents = init->num_parents;
4231 const char * const *parent_names = init->parent_names;
4232 const struct clk_hw **parent_hws = init->parent_hws;
4233 const struct clk_parent_data *parent_data = init->parent_data;
4234 int i, ret = 0;
4235 struct clk_parent_map *parents, *parent;
4236
4237 if (!num_parents)
4238 return 0;
4239
4240 /*
4241 * Avoid unnecessary string look-ups of clk_core's possible parents by
4242 * having a cache of names/clk_hw pointers to clk_core pointers.
4243 */
4244 parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
4245 core->parents = parents;
4246 if (!parents)
4247 return -ENOMEM;
4248
4249 /* Copy everything over because it might be __initdata */
4250 for (i = 0, parent = parents; i < num_parents; i++, parent++) {
4251 parent->index = -1;
4252 if (parent_names) {
4253 /* throw a WARN if any entries are NULL */
4254 WARN(!parent_names[i],
4255 "%s: invalid NULL in %s's .parent_names\n",
4256 __func__, core->name);
4257 ret = clk_cpy_name(&parent->name, parent_names[i],
4258 true);
4259 } else if (parent_data) {
4260 parent->hw = parent_data[i].hw;
4261 parent->index = parent_data[i].index;
4262 ret = clk_cpy_name(&parent->fw_name,
4263 parent_data[i].fw_name, false);
4264 if (!ret)
4265 ret = clk_cpy_name(&parent->name,
4266 parent_data[i].name,
4267 false);
4268 } else if (parent_hws) {
4269 parent->hw = parent_hws[i];
4270 } else {
4271 ret = -EINVAL;
4272 WARN(1, "Must specify parents if num_parents > 0\n");
4273 }
4274
4275 if (ret) {
4276 do {
4277 kfree_const(parents[i].name);
4278 kfree_const(parents[i].fw_name);
4279 } while (--i >= 0);
4280 kfree(parents);
4281
4282 return ret;
4283 }
4284 }
4285
4286 return 0;
4287}
4288
4289static void clk_core_free_parent_map(struct clk_core *core)
4290{
4291 int i = core->num_parents;
4292
4293 if (!core->num_parents)
4294 return;
4295
4296 while (--i >= 0) {
4297 kfree_const(core->parents[i].name);
4298 kfree_const(core->parents[i].fw_name);
4299 }
4300
4301 kfree(core->parents);
4302}
4303
4304/* Free memory allocated for a struct clk_core */
4305static void __clk_release(struct kref *ref)
4306{
4307 struct clk_core *core = container_of(ref, struct clk_core, ref);
4308
4309 if (core->rpm_enabled) {
4310 mutex_lock(&clk_rpm_list_lock);
4311 hlist_del(&core->rpm_node);
4312 mutex_unlock(&clk_rpm_list_lock);
4313 }
4314
4315 clk_core_free_parent_map(core);
4316 kfree_const(core->name);
4317 kfree(core);
4318}
4319
4320static struct clk *
4321__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
4322{
4323 int ret;
4324 struct clk_core *core;
4325 const struct clk_init_data *init = hw->init;
4326
4327 /*
4328 * The init data is not supposed to be used outside of registration path.
4329 * Set it to NULL so that provider drivers can't use it either and so that
4330 * we catch use of hw->init early on in the core.
4331 */
4332 hw->init = NULL;
4333
4334 core = kzalloc(sizeof(*core), GFP_KERNEL);
4335 if (!core) {
4336 ret = -ENOMEM;
4337 goto fail_out;
4338 }
4339
4340 kref_init(&core->ref);
4341
4342 core->name = kstrdup_const(init->name, GFP_KERNEL);
4343 if (!core->name) {
4344 ret = -ENOMEM;
4345 goto fail_name;
4346 }
4347
4348 if (WARN_ON(!init->ops)) {
4349 ret = -EINVAL;
4350 goto fail_ops;
4351 }
4352 core->ops = init->ops;
4353
4354 core->dev = dev;
4355 clk_pm_runtime_init(core);
4356 core->of_node = np;
4357 if (dev && dev->driver)
4358 core->owner = dev->driver->owner;
4359 core->hw = hw;
4360 core->flags = init->flags;
4361 core->num_parents = init->num_parents;
4362 core->min_rate = 0;
4363 core->max_rate = ULONG_MAX;
4364
4365 ret = clk_core_populate_parent_map(core, init);
4366 if (ret)
4367 goto fail_parents;
4368
4369 INIT_HLIST_HEAD(&core->clks);
4370
4371 /*
4372 * Don't call clk_hw_create_clk() here because that would pin the
4373 * provider module to itself and prevent it from ever being removed.
4374 */
4375 hw->clk = alloc_clk(core, NULL, NULL);
4376 if (IS_ERR(hw->clk)) {
4377 ret = PTR_ERR(hw->clk);
4378 goto fail_create_clk;
4379 }
4380
4381 clk_core_link_consumer(core, hw->clk);
4382
4383 ret = __clk_core_init(core);
4384 if (!ret)
4385 return hw->clk;
4386
4387 clk_prepare_lock();
4388 clk_core_unlink_consumer(hw->clk);
4389 clk_prepare_unlock();
4390
4391 free_clk(hw->clk);
4392 hw->clk = NULL;
4393
4394fail_create_clk:
4395fail_parents:
4396fail_ops:
4397fail_name:
4398 kref_put(&core->ref, __clk_release);
4399fail_out:
4400 return ERR_PTR(ret);
4401}
4402
4403/**
4404 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
4405 * @dev: Device to get device node of
4406 *
4407 * Return: device node pointer of @dev, or the device node pointer of
4408 * @dev->parent if dev doesn't have a device node, or NULL if neither
4409 * @dev or @dev->parent have a device node.
4410 */
4411static struct device_node *dev_or_parent_of_node(struct device *dev)
4412{
4413 struct device_node *np;
4414
4415 if (!dev)
4416 return NULL;
4417
4418 np = dev_of_node(dev);
4419 if (!np)
4420 np = dev_of_node(dev->parent);
4421
4422 return np;
4423}
4424
4425/**
4426 * clk_register - allocate a new clock, register it and return an opaque cookie
4427 * @dev: device that is registering this clock
4428 * @hw: link to hardware-specific clock data
4429 *
4430 * clk_register is the *deprecated* interface for populating the clock tree with
4431 * new clock nodes. Use clk_hw_register() instead.
4432 *
4433 * Returns: a pointer to the newly allocated struct clk which
4434 * cannot be dereferenced by driver code but may be used in conjunction with the
4435 * rest of the clock API. In the event of an error clk_register will return an
4436 * error code; drivers must test for an error code after calling clk_register.
4437 */
4438struct clk *clk_register(struct device *dev, struct clk_hw *hw)
4439{
4440 return __clk_register(dev, dev_or_parent_of_node(dev), hw);
4441}
4442EXPORT_SYMBOL_GPL(clk_register);
4443
4444/**
4445 * clk_hw_register - register a clk_hw and return an error code
4446 * @dev: device that is registering this clock
4447 * @hw: link to hardware-specific clock data
4448 *
4449 * clk_hw_register is the primary interface for populating the clock tree with
4450 * new clock nodes. It returns an integer equal to zero indicating success or
4451 * less than zero indicating failure. Drivers must test for an error code after
4452 * calling clk_hw_register().
4453 */
4454int clk_hw_register(struct device *dev, struct clk_hw *hw)
4455{
4456 return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
4457 hw));
4458}
4459EXPORT_SYMBOL_GPL(clk_hw_register);
4460
4461/*
4462 * of_clk_hw_register - register a clk_hw and return an error code
4463 * @node: device_node of device that is registering this clock
4464 * @hw: link to hardware-specific clock data
4465 *
4466 * of_clk_hw_register() is the primary interface for populating the clock tree
4467 * with new clock nodes when a struct device is not available, but a struct
4468 * device_node is. It returns an integer equal to zero indicating success or
4469 * less than zero indicating failure. Drivers must test for an error code after
4470 * calling of_clk_hw_register().
4471 */
4472int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
4473{
4474 return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
4475}
4476EXPORT_SYMBOL_GPL(of_clk_hw_register);
4477
4478/*
4479 * Empty clk_ops for unregistered clocks. These are used temporarily
4480 * after clk_unregister() was called on a clock and until last clock
4481 * consumer calls clk_put() and the struct clk object is freed.
4482 */
4483static int clk_nodrv_prepare_enable(struct clk_hw *hw)
4484{
4485 return -ENXIO;
4486}
4487
4488static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
4489{
4490 WARN_ON_ONCE(1);
4491}
4492
4493static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
4494 unsigned long parent_rate)
4495{
4496 return -ENXIO;
4497}
4498
4499static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
4500{
4501 return -ENXIO;
4502}
4503
4504static int clk_nodrv_determine_rate(struct clk_hw *hw,
4505 struct clk_rate_request *req)
4506{
4507 return -ENXIO;
4508}
4509
4510static const struct clk_ops clk_nodrv_ops = {
4511 .enable = clk_nodrv_prepare_enable,
4512 .disable = clk_nodrv_disable_unprepare,
4513 .prepare = clk_nodrv_prepare_enable,
4514 .unprepare = clk_nodrv_disable_unprepare,
4515 .determine_rate = clk_nodrv_determine_rate,
4516 .set_rate = clk_nodrv_set_rate,
4517 .set_parent = clk_nodrv_set_parent,
4518};
4519
4520static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4521 const struct clk_core *target)
4522{
4523 int i;
4524 struct clk_core *child;
4525
4526 for (i = 0; i < root->num_parents; i++)
4527 if (root->parents[i].core == target)
4528 root->parents[i].core = NULL;
4529
4530 hlist_for_each_entry(child, &root->children, child_node)
4531 clk_core_evict_parent_cache_subtree(child, target);
4532}
4533
4534/* Remove this clk from all parent caches */
4535static void clk_core_evict_parent_cache(struct clk_core *core)
4536{
4537 const struct hlist_head **lists;
4538 struct clk_core *root;
4539
4540 lockdep_assert_held(&prepare_lock);
4541
4542 for (lists = all_lists; *lists; lists++)
4543 hlist_for_each_entry(root, *lists, child_node)
4544 clk_core_evict_parent_cache_subtree(root, core);
4545
4546}
4547
4548/**
4549 * clk_unregister - unregister a currently registered clock
4550 * @clk: clock to unregister
4551 */
4552void clk_unregister(struct clk *clk)
4553{
4554 unsigned long flags;
4555 const struct clk_ops *ops;
4556
4557 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4558 return;
4559
4560 clk_debug_unregister(clk->core);
4561
4562 clk_prepare_lock();
4563
4564 ops = clk->core->ops;
4565 if (ops == &clk_nodrv_ops) {
4566 pr_err("%s: unregistered clock: %s\n", __func__,
4567 clk->core->name);
4568 clk_prepare_unlock();
4569 return;
4570 }
4571 /*
4572 * Assign empty clock ops for consumers that might still hold
4573 * a reference to this clock.
4574 */
4575 flags = clk_enable_lock();
4576 clk->core->ops = &clk_nodrv_ops;
4577 clk_enable_unlock(flags);
4578
4579 if (ops->terminate)
4580 ops->terminate(clk->core->hw);
4581
4582 if (!hlist_empty(&clk->core->children)) {
4583 struct clk_core *child;
4584 struct hlist_node *t;
4585
4586 /* Reparent all children to the orphan list. */
4587 hlist_for_each_entry_safe(child, t, &clk->core->children,
4588 child_node)
4589 clk_core_set_parent_nolock(child, NULL);
4590 }
4591
4592 clk_core_evict_parent_cache(clk->core);
4593
4594 hlist_del_init(&clk->core->child_node);
4595
4596 if (clk->core->prepare_count)
4597 pr_warn("%s: unregistering prepared clock: %s\n",
4598 __func__, clk->core->name);
4599
4600 if (clk->core->protect_count)
4601 pr_warn("%s: unregistering protected clock: %s\n",
4602 __func__, clk->core->name);
4603 clk_prepare_unlock();
4604
4605 kref_put(&clk->core->ref, __clk_release);
4606 free_clk(clk);
4607}
4608EXPORT_SYMBOL_GPL(clk_unregister);
4609
4610/**
4611 * clk_hw_unregister - unregister a currently registered clk_hw
4612 * @hw: hardware-specific clock data to unregister
4613 */
4614void clk_hw_unregister(struct clk_hw *hw)
4615{
4616 clk_unregister(hw->clk);
4617}
4618EXPORT_SYMBOL_GPL(clk_hw_unregister);
4619
4620static void devm_clk_unregister_cb(struct device *dev, void *res)
4621{
4622 clk_unregister(*(struct clk **)res);
4623}
4624
4625static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4626{
4627 clk_hw_unregister(*(struct clk_hw **)res);
4628}
4629
4630/**
4631 * devm_clk_register - resource managed clk_register()
4632 * @dev: device that is registering this clock
4633 * @hw: link to hardware-specific clock data
4634 *
4635 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4636 *
4637 * Clocks returned from this function are automatically clk_unregister()ed on
4638 * driver detach. See clk_register() for more information.
4639 */
4640struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4641{
4642 struct clk *clk;
4643 struct clk **clkp;
4644
4645 clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4646 if (!clkp)
4647 return ERR_PTR(-ENOMEM);
4648
4649 clk = clk_register(dev, hw);
4650 if (!IS_ERR(clk)) {
4651 *clkp = clk;
4652 devres_add(dev, clkp);
4653 } else {
4654 devres_free(clkp);
4655 }
4656
4657 return clk;
4658}
4659EXPORT_SYMBOL_GPL(devm_clk_register);
4660
4661/**
4662 * devm_clk_hw_register - resource managed clk_hw_register()
4663 * @dev: device that is registering this clock
4664 * @hw: link to hardware-specific clock data
4665 *
4666 * Managed clk_hw_register(). Clocks registered by this function are
4667 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4668 * for more information.
4669 */
4670int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4671{
4672 struct clk_hw **hwp;
4673 int ret;
4674
4675 hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4676 if (!hwp)
4677 return -ENOMEM;
4678
4679 ret = clk_hw_register(dev, hw);
4680 if (!ret) {
4681 *hwp = hw;
4682 devres_add(dev, hwp);
4683 } else {
4684 devres_free(hwp);
4685 }
4686
4687 return ret;
4688}
4689EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4690
4691static void devm_clk_release(struct device *dev, void *res)
4692{
4693 clk_put(*(struct clk **)res);
4694}
4695
4696/**
4697 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4698 * @dev: device that is registering this clock
4699 * @hw: clk_hw associated with the clk being consumed
4700 * @con_id: connection ID string on device
4701 *
4702 * Managed clk_hw_get_clk(). Clocks got with this function are
4703 * automatically clk_put() on driver detach. See clk_put()
4704 * for more information.
4705 */
4706struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4707 const char *con_id)
4708{
4709 struct clk *clk;
4710 struct clk **clkp;
4711
4712 /* This should not happen because it would mean we have drivers
4713 * passing around clk_hw pointers instead of having the caller use
4714 * proper clk_get() style APIs
4715 */
4716 WARN_ON_ONCE(dev != hw->core->dev);
4717
4718 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4719 if (!clkp)
4720 return ERR_PTR(-ENOMEM);
4721
4722 clk = clk_hw_get_clk(hw, con_id);
4723 if (!IS_ERR(clk)) {
4724 *clkp = clk;
4725 devres_add(dev, clkp);
4726 } else {
4727 devres_free(clkp);
4728 }
4729
4730 return clk;
4731}
4732EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4733
4734/*
4735 * clkdev helpers
4736 */
4737
4738void __clk_put(struct clk *clk)
4739{
4740 struct module *owner;
4741
4742 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4743 return;
4744
4745 clk_prepare_lock();
4746
4747 /*
4748 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4749 * given user should be balanced with calls to clk_rate_exclusive_put()
4750 * and by that same consumer
4751 */
4752 if (WARN_ON(clk->exclusive_count)) {
4753 /* We voiced our concern, let's sanitize the situation */
4754 clk->core->protect_count -= (clk->exclusive_count - 1);
4755 clk_core_rate_unprotect(clk->core);
4756 clk->exclusive_count = 0;
4757 }
4758
4759 clk_core_unlink_consumer(clk);
4760
4761 /* If we had any boundaries on that clock, let's drop them. */
4762 if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
4763 clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
4764
4765 clk_prepare_unlock();
4766
4767 owner = clk->core->owner;
4768 kref_put(&clk->core->ref, __clk_release);
4769 module_put(owner);
4770 free_clk(clk);
4771}
4772
4773/*** clk rate change notifiers ***/
4774
4775/**
4776 * clk_notifier_register - add a clk rate change notifier
4777 * @clk: struct clk * to watch
4778 * @nb: struct notifier_block * with callback info
4779 *
4780 * Request notification when clk's rate changes. This uses an SRCU
4781 * notifier because we want it to block and notifier unregistrations are
4782 * uncommon. The callbacks associated with the notifier must not
4783 * re-enter into the clk framework by calling any top-level clk APIs;
4784 * this will cause a nested prepare_lock mutex.
4785 *
4786 * In all notification cases (pre, post and abort rate change) the original
4787 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4788 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4789 *
4790 * clk_notifier_register() must be called from non-atomic context.
4791 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4792 * allocation failure; otherwise, passes along the return value of
4793 * srcu_notifier_chain_register().
4794 */
4795int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4796{
4797 struct clk_notifier *cn;
4798 int ret = -ENOMEM;
4799
4800 if (!clk || !nb)
4801 return -EINVAL;
4802
4803 clk_prepare_lock();
4804
4805 /* search the list of notifiers for this clk */
4806 list_for_each_entry(cn, &clk_notifier_list, node)
4807 if (cn->clk == clk)
4808 goto found;
4809
4810 /* if clk wasn't in the notifier list, allocate new clk_notifier */
4811 cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4812 if (!cn)
4813 goto out;
4814
4815 cn->clk = clk;
4816 srcu_init_notifier_head(&cn->notifier_head);
4817
4818 list_add(&cn->node, &clk_notifier_list);
4819
4820found:
4821 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4822
4823 clk->core->notifier_count++;
4824
4825out:
4826 clk_prepare_unlock();
4827
4828 return ret;
4829}
4830EXPORT_SYMBOL_GPL(clk_notifier_register);
4831
4832/**
4833 * clk_notifier_unregister - remove a clk rate change notifier
4834 * @clk: struct clk *
4835 * @nb: struct notifier_block * with callback info
4836 *
4837 * Request no further notification for changes to 'clk' and frees memory
4838 * allocated in clk_notifier_register.
4839 *
4840 * Returns -EINVAL if called with null arguments; otherwise, passes
4841 * along the return value of srcu_notifier_chain_unregister().
4842 */
4843int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4844{
4845 struct clk_notifier *cn;
4846 int ret = -ENOENT;
4847
4848 if (!clk || !nb)
4849 return -EINVAL;
4850
4851 clk_prepare_lock();
4852
4853 list_for_each_entry(cn, &clk_notifier_list, node) {
4854 if (cn->clk == clk) {
4855 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4856
4857 clk->core->notifier_count--;
4858
4859 /* XXX the notifier code should handle this better */
4860 if (!cn->notifier_head.head) {
4861 srcu_cleanup_notifier_head(&cn->notifier_head);
4862 list_del(&cn->node);
4863 kfree(cn);
4864 }
4865 break;
4866 }
4867 }
4868
4869 clk_prepare_unlock();
4870
4871 return ret;
4872}
4873EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4874
4875struct clk_notifier_devres {
4876 struct clk *clk;
4877 struct notifier_block *nb;
4878};
4879
4880static void devm_clk_notifier_release(struct device *dev, void *res)
4881{
4882 struct clk_notifier_devres *devres = res;
4883
4884 clk_notifier_unregister(devres->clk, devres->nb);
4885}
4886
4887int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4888 struct notifier_block *nb)
4889{
4890 struct clk_notifier_devres *devres;
4891 int ret;
4892
4893 devres = devres_alloc(devm_clk_notifier_release,
4894 sizeof(*devres), GFP_KERNEL);
4895
4896 if (!devres)
4897 return -ENOMEM;
4898
4899 ret = clk_notifier_register(clk, nb);
4900 if (!ret) {
4901 devres->clk = clk;
4902 devres->nb = nb;
4903 devres_add(dev, devres);
4904 } else {
4905 devres_free(devres);
4906 }
4907
4908 return ret;
4909}
4910EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4911
4912#ifdef CONFIG_OF
4913static void clk_core_reparent_orphans(void)
4914{
4915 clk_prepare_lock();
4916 clk_core_reparent_orphans_nolock();
4917 clk_prepare_unlock();
4918}
4919
4920/**
4921 * struct of_clk_provider - Clock provider registration structure
4922 * @link: Entry in global list of clock providers
4923 * @node: Pointer to device tree node of clock provider
4924 * @get: Get clock callback. Returns NULL or a struct clk for the
4925 * given clock specifier
4926 * @get_hw: Get clk_hw callback. Returns NULL, ERR_PTR or a
4927 * struct clk_hw for the given clock specifier
4928 * @data: context pointer to be passed into @get callback
4929 */
4930struct of_clk_provider {
4931 struct list_head link;
4932
4933 struct device_node *node;
4934 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4935 struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4936 void *data;
4937};
4938
4939extern struct of_device_id __clk_of_table;
4940static const struct of_device_id __clk_of_table_sentinel
4941 __used __section("__clk_of_table_end");
4942
4943static LIST_HEAD(of_clk_providers);
4944static DEFINE_MUTEX(of_clk_mutex);
4945
4946struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4947 void *data)
4948{
4949 return data;
4950}
4951EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4952
4953struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4954{
4955 return data;
4956}
4957EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4958
4959struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4960{
4961 struct clk_onecell_data *clk_data = data;
4962 unsigned int idx = clkspec->args[0];
4963
4964 if (idx >= clk_data->clk_num) {
4965 pr_err("%s: invalid clock index %u\n", __func__, idx);
4966 return ERR_PTR(-EINVAL);
4967 }
4968
4969 return clk_data->clks[idx];
4970}
4971EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4972
4973struct clk_hw *
4974of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4975{
4976 struct clk_hw_onecell_data *hw_data = data;
4977 unsigned int idx = clkspec->args[0];
4978
4979 if (idx >= hw_data->num) {
4980 pr_err("%s: invalid index %u\n", __func__, idx);
4981 return ERR_PTR(-EINVAL);
4982 }
4983
4984 return hw_data->hws[idx];
4985}
4986EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4987
4988/**
4989 * of_clk_add_provider() - Register a clock provider for a node
4990 * @np: Device node pointer associated with clock provider
4991 * @clk_src_get: callback for decoding clock
4992 * @data: context pointer for @clk_src_get callback.
4993 *
4994 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
4995 */
4996int of_clk_add_provider(struct device_node *np,
4997 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
4998 void *data),
4999 void *data)
5000{
5001 struct of_clk_provider *cp;
5002 int ret;
5003
5004 if (!np)
5005 return 0;
5006
5007 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
5008 if (!cp)
5009 return -ENOMEM;
5010
5011 cp->node = of_node_get(np);
5012 cp->data = data;
5013 cp->get = clk_src_get;
5014
5015 mutex_lock(&of_clk_mutex);
5016 list_add(&cp->link, &of_clk_providers);
5017 mutex_unlock(&of_clk_mutex);
5018 pr_debug("Added clock from %pOF\n", np);
5019
5020 clk_core_reparent_orphans();
5021
5022 ret = of_clk_set_defaults(np, true);
5023 if (ret < 0)
5024 of_clk_del_provider(np);
5025
5026 fwnode_dev_initialized(&np->fwnode, true);
5027
5028 return ret;
5029}
5030EXPORT_SYMBOL_GPL(of_clk_add_provider);
5031
5032/**
5033 * of_clk_add_hw_provider() - Register a clock provider for a node
5034 * @np: Device node pointer associated with clock provider
5035 * @get: callback for decoding clk_hw
5036 * @data: context pointer for @get callback.
5037 */
5038int of_clk_add_hw_provider(struct device_node *np,
5039 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
5040 void *data),
5041 void *data)
5042{
5043 struct of_clk_provider *cp;
5044 int ret;
5045
5046 if (!np)
5047 return 0;
5048
5049 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
5050 if (!cp)
5051 return -ENOMEM;
5052
5053 cp->node = of_node_get(np);
5054 cp->data = data;
5055 cp->get_hw = get;
5056
5057 mutex_lock(&of_clk_mutex);
5058 list_add(&cp->link, &of_clk_providers);
5059 mutex_unlock(&of_clk_mutex);
5060 pr_debug("Added clk_hw provider from %pOF\n", np);
5061
5062 clk_core_reparent_orphans();
5063
5064 ret = of_clk_set_defaults(np, true);
5065 if (ret < 0)
5066 of_clk_del_provider(np);
5067
5068 fwnode_dev_initialized(&np->fwnode, true);
5069
5070 return ret;
5071}
5072EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
5073
5074static void devm_of_clk_release_provider(struct device *dev, void *res)
5075{
5076 of_clk_del_provider(*(struct device_node **)res);
5077}
5078
5079/*
5080 * We allow a child device to use its parent device as the clock provider node
5081 * for cases like MFD sub-devices where the child device driver wants to use
5082 * devm_*() APIs but not list the device in DT as a sub-node.
5083 */
5084static struct device_node *get_clk_provider_node(struct device *dev)
5085{
5086 struct device_node *np, *parent_np;
5087
5088 np = dev->of_node;
5089 parent_np = dev->parent ? dev->parent->of_node : NULL;
5090
5091 if (!of_property_present(np, "#clock-cells"))
5092 if (of_property_present(parent_np, "#clock-cells"))
5093 np = parent_np;
5094
5095 return np;
5096}
5097
5098/**
5099 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
5100 * @dev: Device acting as the clock provider (used for DT node and lifetime)
5101 * @get: callback for decoding clk_hw
5102 * @data: context pointer for @get callback
5103 *
5104 * Registers clock provider for given device's node. If the device has no DT
5105 * node or if the device node lacks of clock provider information (#clock-cells)
5106 * then the parent device's node is scanned for this information. If parent node
5107 * has the #clock-cells then it is used in registration. Provider is
5108 * automatically released at device exit.
5109 *
5110 * Return: 0 on success or an errno on failure.
5111 */
5112int devm_of_clk_add_hw_provider(struct device *dev,
5113 struct clk_hw *(*get)(struct of_phandle_args *clkspec,
5114 void *data),
5115 void *data)
5116{
5117 struct device_node **ptr, *np;
5118 int ret;
5119
5120 ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
5121 GFP_KERNEL);
5122 if (!ptr)
5123 return -ENOMEM;
5124
5125 np = get_clk_provider_node(dev);
5126 ret = of_clk_add_hw_provider(np, get, data);
5127 if (!ret) {
5128 *ptr = np;
5129 devres_add(dev, ptr);
5130 } else {
5131 devres_free(ptr);
5132 }
5133
5134 return ret;
5135}
5136EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
5137
5138/**
5139 * of_clk_del_provider() - Remove a previously registered clock provider
5140 * @np: Device node pointer associated with clock provider
5141 */
5142void of_clk_del_provider(struct device_node *np)
5143{
5144 struct of_clk_provider *cp;
5145
5146 if (!np)
5147 return;
5148
5149 mutex_lock(&of_clk_mutex);
5150 list_for_each_entry(cp, &of_clk_providers, link) {
5151 if (cp->node == np) {
5152 list_del(&cp->link);
5153 fwnode_dev_initialized(&np->fwnode, false);
5154 of_node_put(cp->node);
5155 kfree(cp);
5156 break;
5157 }
5158 }
5159 mutex_unlock(&of_clk_mutex);
5160}
5161EXPORT_SYMBOL_GPL(of_clk_del_provider);
5162
5163/**
5164 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
5165 * @np: device node to parse clock specifier from
5166 * @index: index of phandle to parse clock out of. If index < 0, @name is used
5167 * @name: clock name to find and parse. If name is NULL, the index is used
5168 * @out_args: Result of parsing the clock specifier
5169 *
5170 * Parses a device node's "clocks" and "clock-names" properties to find the
5171 * phandle and cells for the index or name that is desired. The resulting clock
5172 * specifier is placed into @out_args, or an errno is returned when there's a
5173 * parsing error. The @index argument is ignored if @name is non-NULL.
5174 *
5175 * Example:
5176 *
5177 * phandle1: clock-controller@1 {
5178 * #clock-cells = <2>;
5179 * }
5180 *
5181 * phandle2: clock-controller@2 {
5182 * #clock-cells = <1>;
5183 * }
5184 *
5185 * clock-consumer@3 {
5186 * clocks = <&phandle1 1 2 &phandle2 3>;
5187 * clock-names = "name1", "name2";
5188 * }
5189 *
5190 * To get a device_node for `clock-controller@2' node you may call this
5191 * function a few different ways:
5192 *
5193 * of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
5194 * of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
5195 * of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
5196 *
5197 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
5198 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
5199 * the "clock-names" property of @np.
5200 */
5201static int of_parse_clkspec(const struct device_node *np, int index,
5202 const char *name, struct of_phandle_args *out_args)
5203{
5204 int ret = -ENOENT;
5205
5206 /* Walk up the tree of devices looking for a clock property that matches */
5207 while (np) {
5208 /*
5209 * For named clocks, first look up the name in the
5210 * "clock-names" property. If it cannot be found, then index
5211 * will be an error code and of_parse_phandle_with_args() will
5212 * return -EINVAL.
5213 */
5214 if (name)
5215 index = of_property_match_string(np, "clock-names", name);
5216 ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
5217 index, out_args);
5218 if (!ret)
5219 break;
5220 if (name && index >= 0)
5221 break;
5222
5223 /*
5224 * No matching clock found on this node. If the parent node
5225 * has a "clock-ranges" property, then we can try one of its
5226 * clocks.
5227 */
5228 np = np->parent;
5229 if (np && !of_property_present(np, "clock-ranges"))
5230 break;
5231 index = 0;
5232 }
5233
5234 return ret;
5235}
5236
5237static struct clk_hw *
5238__of_clk_get_hw_from_provider(struct of_clk_provider *provider,
5239 struct of_phandle_args *clkspec)
5240{
5241 struct clk *clk;
5242
5243 if (provider->get_hw)
5244 return provider->get_hw(clkspec, provider->data);
5245
5246 clk = provider->get(clkspec, provider->data);
5247 if (IS_ERR(clk))
5248 return ERR_CAST(clk);
5249 return __clk_get_hw(clk);
5250}
5251
5252static struct clk_hw *
5253of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
5254{
5255 struct of_clk_provider *provider;
5256 struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
5257
5258 if (!clkspec)
5259 return ERR_PTR(-EINVAL);
5260
5261 mutex_lock(&of_clk_mutex);
5262 list_for_each_entry(provider, &of_clk_providers, link) {
5263 if (provider->node == clkspec->np) {
5264 hw = __of_clk_get_hw_from_provider(provider, clkspec);
5265 if (!IS_ERR(hw))
5266 break;
5267 }
5268 }
5269 mutex_unlock(&of_clk_mutex);
5270
5271 return hw;
5272}
5273
5274/**
5275 * of_clk_get_from_provider() - Lookup a clock from a clock provider
5276 * @clkspec: pointer to a clock specifier data structure
5277 *
5278 * This function looks up a struct clk from the registered list of clock
5279 * providers, an input is a clock specifier data structure as returned
5280 * from the of_parse_phandle_with_args() function call.
5281 */
5282struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
5283{
5284 struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
5285
5286 return clk_hw_create_clk(NULL, hw, NULL, __func__);
5287}
5288EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
5289
5290struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
5291 const char *con_id)
5292{
5293 int ret;
5294 struct clk_hw *hw;
5295 struct of_phandle_args clkspec;
5296
5297 ret = of_parse_clkspec(np, index, con_id, &clkspec);
5298 if (ret)
5299 return ERR_PTR(ret);
5300
5301 hw = of_clk_get_hw_from_clkspec(&clkspec);
5302 of_node_put(clkspec.np);
5303
5304 return hw;
5305}
5306
5307static struct clk *__of_clk_get(struct device_node *np,
5308 int index, const char *dev_id,
5309 const char *con_id)
5310{
5311 struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
5312
5313 return clk_hw_create_clk(NULL, hw, dev_id, con_id);
5314}
5315
5316struct clk *of_clk_get(struct device_node *np, int index)
5317{
5318 return __of_clk_get(np, index, np->full_name, NULL);
5319}
5320EXPORT_SYMBOL(of_clk_get);
5321
5322/**
5323 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
5324 * @np: pointer to clock consumer node
5325 * @name: name of consumer's clock input, or NULL for the first clock reference
5326 *
5327 * This function parses the clocks and clock-names properties,
5328 * and uses them to look up the struct clk from the registered list of clock
5329 * providers.
5330 */
5331struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
5332{
5333 if (!np)
5334 return ERR_PTR(-ENOENT);
5335
5336 return __of_clk_get(np, 0, np->full_name, name);
5337}
5338EXPORT_SYMBOL(of_clk_get_by_name);
5339
5340/**
5341 * of_clk_get_parent_count() - Count the number of clocks a device node has
5342 * @np: device node to count
5343 *
5344 * Returns: The number of clocks that are possible parents of this node
5345 */
5346unsigned int of_clk_get_parent_count(const struct device_node *np)
5347{
5348 int count;
5349
5350 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
5351 if (count < 0)
5352 return 0;
5353
5354 return count;
5355}
5356EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
5357
5358const char *of_clk_get_parent_name(const struct device_node *np, int index)
5359{
5360 struct of_phandle_args clkspec;
5361 const char *clk_name;
5362 bool found = false;
5363 u32 pv;
5364 int rc;
5365 int count;
5366 struct clk *clk;
5367
5368 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
5369 &clkspec);
5370 if (rc)
5371 return NULL;
5372
5373 index = clkspec.args_count ? clkspec.args[0] : 0;
5374 count = 0;
5375
5376 /* if there is an indices property, use it to transfer the index
5377 * specified into an array offset for the clock-output-names property.
5378 */
5379 of_property_for_each_u32(clkspec.np, "clock-indices", pv) {
5380 if (index == pv) {
5381 index = count;
5382 found = true;
5383 break;
5384 }
5385 count++;
5386 }
5387 /* We went off the end of 'clock-indices' without finding it */
5388 if (of_property_present(clkspec.np, "clock-indices") && !found) {
5389 of_node_put(clkspec.np);
5390 return NULL;
5391 }
5392
5393 if (of_property_read_string_index(clkspec.np, "clock-output-names",
5394 index,
5395 &clk_name) < 0) {
5396 /*
5397 * Best effort to get the name if the clock has been
5398 * registered with the framework. If the clock isn't
5399 * registered, we return the node name as the name of
5400 * the clock as long as #clock-cells = 0.
5401 */
5402 clk = of_clk_get_from_provider(&clkspec);
5403 if (IS_ERR(clk)) {
5404 if (clkspec.args_count == 0)
5405 clk_name = clkspec.np->name;
5406 else
5407 clk_name = NULL;
5408 } else {
5409 clk_name = __clk_get_name(clk);
5410 clk_put(clk);
5411 }
5412 }
5413
5414
5415 of_node_put(clkspec.np);
5416 return clk_name;
5417}
5418EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
5419
5420/**
5421 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
5422 * number of parents
5423 * @np: Device node pointer associated with clock provider
5424 * @parents: pointer to char array that hold the parents' names
5425 * @size: size of the @parents array
5426 *
5427 * Return: number of parents for the clock node.
5428 */
5429int of_clk_parent_fill(struct device_node *np, const char **parents,
5430 unsigned int size)
5431{
5432 unsigned int i = 0;
5433
5434 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
5435 i++;
5436
5437 return i;
5438}
5439EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5440
5441struct clock_provider {
5442 void (*clk_init_cb)(struct device_node *);
5443 struct device_node *np;
5444 struct list_head node;
5445};
5446
5447/*
5448 * This function looks for a parent clock. If there is one, then it
5449 * checks that the provider for this parent clock was initialized, in
5450 * this case the parent clock will be ready.
5451 */
5452static int parent_ready(struct device_node *np)
5453{
5454 int i = 0;
5455
5456 while (true) {
5457 struct clk *clk = of_clk_get(np, i);
5458
5459 /* this parent is ready we can check the next one */
5460 if (!IS_ERR(clk)) {
5461 clk_put(clk);
5462 i++;
5463 continue;
5464 }
5465
5466 /* at least one parent is not ready, we exit now */
5467 if (PTR_ERR(clk) == -EPROBE_DEFER)
5468 return 0;
5469
5470 /*
5471 * Here we make assumption that the device tree is
5472 * written correctly. So an error means that there is
5473 * no more parent. As we didn't exit yet, then the
5474 * previous parent are ready. If there is no clock
5475 * parent, no need to wait for them, then we can
5476 * consider their absence as being ready
5477 */
5478 return 1;
5479 }
5480}
5481
5482/**
5483 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5484 * @np: Device node pointer associated with clock provider
5485 * @index: clock index
5486 * @flags: pointer to top-level framework flags
5487 *
5488 * Detects if the clock-critical property exists and, if so, sets the
5489 * corresponding CLK_IS_CRITICAL flag.
5490 *
5491 * Do not use this function. It exists only for legacy Device Tree
5492 * bindings, such as the one-clock-per-node style that are outdated.
5493 * Those bindings typically put all clock data into .dts and the Linux
5494 * driver has no clock data, thus making it impossible to set this flag
5495 * correctly from the driver. Only those drivers may call
5496 * of_clk_detect_critical from their setup functions.
5497 *
5498 * Return: error code or zero on success
5499 */
5500int of_clk_detect_critical(struct device_node *np, int index,
5501 unsigned long *flags)
5502{
5503 uint32_t idx;
5504
5505 if (!np || !flags)
5506 return -EINVAL;
5507
5508 of_property_for_each_u32(np, "clock-critical", idx)
5509 if (index == idx)
5510 *flags |= CLK_IS_CRITICAL;
5511
5512 return 0;
5513}
5514
5515/**
5516 * of_clk_init() - Scan and init clock providers from the DT
5517 * @matches: array of compatible values and init functions for providers.
5518 *
5519 * This function scans the device tree for matching clock providers
5520 * and calls their initialization functions. It also does it by trying
5521 * to follow the dependencies.
5522 */
5523void __init of_clk_init(const struct of_device_id *matches)
5524{
5525 const struct of_device_id *match;
5526 struct device_node *np;
5527 struct clock_provider *clk_provider, *next;
5528 bool is_init_done;
5529 bool force = false;
5530 LIST_HEAD(clk_provider_list);
5531
5532 if (!matches)
5533 matches = &__clk_of_table;
5534
5535 /* First prepare the list of the clocks providers */
5536 for_each_matching_node_and_match(np, matches, &match) {
5537 struct clock_provider *parent;
5538
5539 if (!of_device_is_available(np))
5540 continue;
5541
5542 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
5543 if (!parent) {
5544 list_for_each_entry_safe(clk_provider, next,
5545 &clk_provider_list, node) {
5546 list_del(&clk_provider->node);
5547 of_node_put(clk_provider->np);
5548 kfree(clk_provider);
5549 }
5550 of_node_put(np);
5551 return;
5552 }
5553
5554 parent->clk_init_cb = match->data;
5555 parent->np = of_node_get(np);
5556 list_add_tail(&parent->node, &clk_provider_list);
5557 }
5558
5559 while (!list_empty(&clk_provider_list)) {
5560 is_init_done = false;
5561 list_for_each_entry_safe(clk_provider, next,
5562 &clk_provider_list, node) {
5563 if (force || parent_ready(clk_provider->np)) {
5564
5565 /* Don't populate platform devices */
5566 of_node_set_flag(clk_provider->np,
5567 OF_POPULATED);
5568
5569 clk_provider->clk_init_cb(clk_provider->np);
5570 of_clk_set_defaults(clk_provider->np, true);
5571
5572 list_del(&clk_provider->node);
5573 of_node_put(clk_provider->np);
5574 kfree(clk_provider);
5575 is_init_done = true;
5576 }
5577 }
5578
5579 /*
5580 * We didn't manage to initialize any of the
5581 * remaining providers during the last loop, so now we
5582 * initialize all the remaining ones unconditionally
5583 * in case the clock parent was not mandatory
5584 */
5585 if (!is_init_done)
5586 force = true;
5587 }
5588}
5589#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
175static void clk_unprepare_unused_subtree(struct clk_core *core)
176{
177 struct clk_core *child;
178
179 lockdep_assert_held(&prepare_lock);
180
181 hlist_for_each_entry(child, &core->children, child_node)
182 clk_unprepare_unused_subtree(child);
183
184 if (core->prepare_count)
185 return;
186
187 if (core->flags & CLK_IGNORE_UNUSED)
188 return;
189
190 if (clk_core_is_prepared(core)) {
191 trace_clk_unprepare(core);
192 if (core->ops->unprepare_unused)
193 core->ops->unprepare_unused(core->hw);
194 else if (core->ops->unprepare)
195 core->ops->unprepare(core->hw);
196 trace_clk_unprepare_complete(core);
197 }
198}
199
200static void clk_disable_unused_subtree(struct clk_core *core)
201{
202 struct clk_core *child;
203 unsigned long flags;
204
205 lockdep_assert_held(&prepare_lock);
206
207 hlist_for_each_entry(child, &core->children, child_node)
208 clk_disable_unused_subtree(child);
209
210 flags = clk_enable_lock();
211
212 if (core->enable_count)
213 goto unlock_out;
214
215 if (core->flags & CLK_IGNORE_UNUSED)
216 goto unlock_out;
217
218 /*
219 * some gate clocks have special needs during the disable-unused
220 * sequence. call .disable_unused if available, otherwise fall
221 * back to .disable
222 */
223 if (clk_core_is_enabled(core)) {
224 trace_clk_disable(core);
225 if (core->ops->disable_unused)
226 core->ops->disable_unused(core->hw);
227 else if (core->ops->disable)
228 core->ops->disable(core->hw);
229 trace_clk_disable_complete(core);
230 }
231
232unlock_out:
233 clk_enable_unlock(flags);
234}
235
236static bool clk_ignore_unused;
237static int __init clk_ignore_unused_setup(char *__unused)
238{
239 clk_ignore_unused = true;
240 return 1;
241}
242__setup("clk_ignore_unused", clk_ignore_unused_setup);
243
244static int clk_disable_unused(void)
245{
246 struct clk_core *core;
247
248 if (clk_ignore_unused) {
249 pr_warn("clk: Not disabling unused clocks\n");
250 return 0;
251 }
252
253 clk_prepare_lock();
254
255 hlist_for_each_entry(core, &clk_root_list, child_node)
256 clk_disable_unused_subtree(core);
257
258 hlist_for_each_entry(core, &clk_orphan_list, child_node)
259 clk_disable_unused_subtree(core);
260
261 hlist_for_each_entry(core, &clk_root_list, child_node)
262 clk_unprepare_unused_subtree(core);
263
264 hlist_for_each_entry(core, &clk_orphan_list, child_node)
265 clk_unprepare_unused_subtree(core);
266
267 clk_prepare_unlock();
268
269 return 0;
270}
271late_initcall_sync(clk_disable_unused);
272
273/*** helper functions ***/
274
275const char *__clk_get_name(const struct clk *clk)
276{
277 return !clk ? NULL : clk->core->name;
278}
279EXPORT_SYMBOL_GPL(__clk_get_name);
280
281const char *clk_hw_get_name(const struct clk_hw *hw)
282{
283 return hw->core->name;
284}
285EXPORT_SYMBOL_GPL(clk_hw_get_name);
286
287struct clk_hw *__clk_get_hw(struct clk *clk)
288{
289 return !clk ? NULL : clk->core->hw;
290}
291EXPORT_SYMBOL_GPL(__clk_get_hw);
292
293unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
294{
295 return hw->core->num_parents;
296}
297EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
298
299struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
300{
301 return hw->core->parent ? hw->core->parent->hw : NULL;
302}
303EXPORT_SYMBOL_GPL(clk_hw_get_parent);
304
305static struct clk_core *__clk_lookup_subtree(const char *name,
306 struct clk_core *core)
307{
308 struct clk_core *child;
309 struct clk_core *ret;
310
311 if (!strcmp(core->name, name))
312 return core;
313
314 hlist_for_each_entry(child, &core->children, child_node) {
315 ret = __clk_lookup_subtree(name, child);
316 if (ret)
317 return ret;
318 }
319
320 return NULL;
321}
322
323static struct clk_core *clk_core_lookup(const char *name)
324{
325 struct clk_core *root_clk;
326 struct clk_core *ret;
327
328 if (!name)
329 return NULL;
330
331 /* search the 'proper' clk tree first */
332 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
333 ret = __clk_lookup_subtree(name, root_clk);
334 if (ret)
335 return ret;
336 }
337
338 /* if not found, then search the orphan tree */
339 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
340 ret = __clk_lookup_subtree(name, root_clk);
341 if (ret)
342 return ret;
343 }
344
345 return NULL;
346}
347
348static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
349 u8 index)
350{
351 if (!core || index >= core->num_parents)
352 return NULL;
353
354 if (!core->parents[index])
355 core->parents[index] =
356 clk_core_lookup(core->parent_names[index]);
357
358 return core->parents[index];
359}
360
361struct clk_hw *
362clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
363{
364 struct clk_core *parent;
365
366 parent = clk_core_get_parent_by_index(hw->core, index);
367
368 return !parent ? NULL : parent->hw;
369}
370EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
371
372unsigned int __clk_get_enable_count(struct clk *clk)
373{
374 return !clk ? 0 : clk->core->enable_count;
375}
376
377static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
378{
379 unsigned long ret;
380
381 if (!core) {
382 ret = 0;
383 goto out;
384 }
385
386 ret = core->rate;
387
388 if (!core->num_parents)
389 goto out;
390
391 if (!core->parent)
392 ret = 0;
393
394out:
395 return ret;
396}
397
398unsigned long clk_hw_get_rate(const struct clk_hw *hw)
399{
400 return clk_core_get_rate_nolock(hw->core);
401}
402EXPORT_SYMBOL_GPL(clk_hw_get_rate);
403
404static unsigned long __clk_get_accuracy(struct clk_core *core)
405{
406 if (!core)
407 return 0;
408
409 return core->accuracy;
410}
411
412unsigned long __clk_get_flags(struct clk *clk)
413{
414 return !clk ? 0 : clk->core->flags;
415}
416EXPORT_SYMBOL_GPL(__clk_get_flags);
417
418unsigned long clk_hw_get_flags(const struct clk_hw *hw)
419{
420 return hw->core->flags;
421}
422EXPORT_SYMBOL_GPL(clk_hw_get_flags);
423
424bool clk_hw_is_prepared(const struct clk_hw *hw)
425{
426 return clk_core_is_prepared(hw->core);
427}
428
429bool clk_hw_is_enabled(const struct clk_hw *hw)
430{
431 return clk_core_is_enabled(hw->core);
432}
433
434bool __clk_is_enabled(struct clk *clk)
435{
436 if (!clk)
437 return false;
438
439 return clk_core_is_enabled(clk->core);
440}
441EXPORT_SYMBOL_GPL(__clk_is_enabled);
442
443static bool mux_is_better_rate(unsigned long rate, unsigned long now,
444 unsigned long best, unsigned long flags)
445{
446 if (flags & CLK_MUX_ROUND_CLOSEST)
447 return abs(now - rate) < abs(best - rate);
448
449 return now <= rate && now > best;
450}
451
452static int
453clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
454 unsigned long flags)
455{
456 struct clk_core *core = hw->core, *parent, *best_parent = NULL;
457 int i, num_parents, ret;
458 unsigned long best = 0;
459 struct clk_rate_request parent_req = *req;
460
461 /* if NO_REPARENT flag set, pass through to current parent */
462 if (core->flags & CLK_SET_RATE_NO_REPARENT) {
463 parent = core->parent;
464 if (core->flags & CLK_SET_RATE_PARENT) {
465 ret = __clk_determine_rate(parent ? parent->hw : NULL,
466 &parent_req);
467 if (ret)
468 return ret;
469
470 best = parent_req.rate;
471 } else if (parent) {
472 best = clk_core_get_rate_nolock(parent);
473 } else {
474 best = clk_core_get_rate_nolock(core);
475 }
476
477 goto out;
478 }
479
480 /* find the parent that can provide the fastest rate <= rate */
481 num_parents = core->num_parents;
482 for (i = 0; i < num_parents; i++) {
483 parent = clk_core_get_parent_by_index(core, i);
484 if (!parent)
485 continue;
486
487 if (core->flags & CLK_SET_RATE_PARENT) {
488 parent_req = *req;
489 ret = __clk_determine_rate(parent->hw, &parent_req);
490 if (ret)
491 continue;
492 } else {
493 parent_req.rate = clk_core_get_rate_nolock(parent);
494 }
495
496 if (mux_is_better_rate(req->rate, parent_req.rate,
497 best, flags)) {
498 best_parent = parent;
499 best = parent_req.rate;
500 }
501 }
502
503 if (!best_parent)
504 return -EINVAL;
505
506out:
507 if (best_parent)
508 req->best_parent_hw = best_parent->hw;
509 req->best_parent_rate = best;
510 req->rate = best;
511
512 return 0;
513}
514
515struct clk *__clk_lookup(const char *name)
516{
517 struct clk_core *core = clk_core_lookup(name);
518
519 return !core ? NULL : core->hw->clk;
520}
521
522static void clk_core_get_boundaries(struct clk_core *core,
523 unsigned long *min_rate,
524 unsigned long *max_rate)
525{
526 struct clk *clk_user;
527
528 *min_rate = core->min_rate;
529 *max_rate = core->max_rate;
530
531 hlist_for_each_entry(clk_user, &core->clks, clks_node)
532 *min_rate = max(*min_rate, clk_user->min_rate);
533
534 hlist_for_each_entry(clk_user, &core->clks, clks_node)
535 *max_rate = min(*max_rate, clk_user->max_rate);
536}
537
538void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
539 unsigned long max_rate)
540{
541 hw->core->min_rate = min_rate;
542 hw->core->max_rate = max_rate;
543}
544EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
545
546/*
547 * Helper for finding best parent to provide a given frequency. This can be used
548 * directly as a determine_rate callback (e.g. for a mux), or from a more
549 * complex clock that may combine a mux with other operations.
550 */
551int __clk_mux_determine_rate(struct clk_hw *hw,
552 struct clk_rate_request *req)
553{
554 return clk_mux_determine_rate_flags(hw, req, 0);
555}
556EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
557
558int __clk_mux_determine_rate_closest(struct clk_hw *hw,
559 struct clk_rate_request *req)
560{
561 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
562}
563EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
564
565/*** clk api ***/
566
567static void clk_core_unprepare(struct clk_core *core)
568{
569 lockdep_assert_held(&prepare_lock);
570
571 if (!core)
572 return;
573
574 if (WARN_ON(core->prepare_count == 0))
575 return;
576
577 if (--core->prepare_count > 0)
578 return;
579
580 WARN_ON(core->enable_count > 0);
581
582 trace_clk_unprepare(core);
583
584 if (core->ops->unprepare)
585 core->ops->unprepare(core->hw);
586
587 trace_clk_unprepare_complete(core);
588 clk_core_unprepare(core->parent);
589}
590
591/**
592 * clk_unprepare - undo preparation of a clock source
593 * @clk: the clk being unprepared
594 *
595 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
596 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
597 * if the operation may sleep. One example is a clk which is accessed over
598 * I2c. In the complex case a clk gate operation may require a fast and a slow
599 * part. It is this reason that clk_unprepare and clk_disable are not mutually
600 * exclusive. In fact clk_disable must be called before clk_unprepare.
601 */
602void clk_unprepare(struct clk *clk)
603{
604 if (IS_ERR_OR_NULL(clk))
605 return;
606
607 clk_prepare_lock();
608 clk_core_unprepare(clk->core);
609 clk_prepare_unlock();
610}
611EXPORT_SYMBOL_GPL(clk_unprepare);
612
613static int clk_core_prepare(struct clk_core *core)
614{
615 int ret = 0;
616
617 lockdep_assert_held(&prepare_lock);
618
619 if (!core)
620 return 0;
621
622 if (core->prepare_count == 0) {
623 ret = clk_core_prepare(core->parent);
624 if (ret)
625 return ret;
626
627 trace_clk_prepare(core);
628
629 if (core->ops->prepare)
630 ret = core->ops->prepare(core->hw);
631
632 trace_clk_prepare_complete(core);
633
634 if (ret) {
635 clk_core_unprepare(core->parent);
636 return ret;
637 }
638 }
639
640 core->prepare_count++;
641
642 return 0;
643}
644
645/**
646 * clk_prepare - prepare a clock source
647 * @clk: the clk being prepared
648 *
649 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
650 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
651 * operation may sleep. One example is a clk which is accessed over I2c. In
652 * the complex case a clk ungate operation may require a fast and a slow part.
653 * It is this reason that clk_prepare and clk_enable are not mutually
654 * exclusive. In fact clk_prepare must be called before clk_enable.
655 * Returns 0 on success, -EERROR otherwise.
656 */
657int clk_prepare(struct clk *clk)
658{
659 int ret;
660
661 if (!clk)
662 return 0;
663
664 clk_prepare_lock();
665 ret = clk_core_prepare(clk->core);
666 clk_prepare_unlock();
667
668 return ret;
669}
670EXPORT_SYMBOL_GPL(clk_prepare);
671
672static void clk_core_disable(struct clk_core *core)
673{
674 lockdep_assert_held(&enable_lock);
675
676 if (!core)
677 return;
678
679 if (WARN_ON(core->enable_count == 0))
680 return;
681
682 if (--core->enable_count > 0)
683 return;
684
685 trace_clk_disable(core);
686
687 if (core->ops->disable)
688 core->ops->disable(core->hw);
689
690 trace_clk_disable_complete(core);
691
692 clk_core_disable(core->parent);
693}
694
695/**
696 * clk_disable - gate a clock
697 * @clk: the clk being gated
698 *
699 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
700 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
701 * clk if the operation is fast and will never sleep. One example is a
702 * SoC-internal clk which is controlled via simple register writes. In the
703 * complex case a clk gate operation may require a fast and a slow part. It is
704 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
705 * In fact clk_disable must be called before clk_unprepare.
706 */
707void clk_disable(struct clk *clk)
708{
709 unsigned long flags;
710
711 if (IS_ERR_OR_NULL(clk))
712 return;
713
714 flags = clk_enable_lock();
715 clk_core_disable(clk->core);
716 clk_enable_unlock(flags);
717}
718EXPORT_SYMBOL_GPL(clk_disable);
719
720static int clk_core_enable(struct clk_core *core)
721{
722 int ret = 0;
723
724 lockdep_assert_held(&enable_lock);
725
726 if (!core)
727 return 0;
728
729 if (WARN_ON(core->prepare_count == 0))
730 return -ESHUTDOWN;
731
732 if (core->enable_count == 0) {
733 ret = clk_core_enable(core->parent);
734
735 if (ret)
736 return ret;
737
738 trace_clk_enable(core);
739
740 if (core->ops->enable)
741 ret = core->ops->enable(core->hw);
742
743 trace_clk_enable_complete(core);
744
745 if (ret) {
746 clk_core_disable(core->parent);
747 return ret;
748 }
749 }
750
751 core->enable_count++;
752 return 0;
753}
754
755/**
756 * clk_enable - ungate a clock
757 * @clk: the clk being ungated
758 *
759 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
760 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
761 * if the operation will never sleep. One example is a SoC-internal clk which
762 * is controlled via simple register writes. In the complex case a clk ungate
763 * operation may require a fast and a slow part. It is this reason that
764 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
765 * must be called before clk_enable. Returns 0 on success, -EERROR
766 * otherwise.
767 */
768int clk_enable(struct clk *clk)
769{
770 unsigned long flags;
771 int ret;
772
773 if (!clk)
774 return 0;
775
776 flags = clk_enable_lock();
777 ret = clk_core_enable(clk->core);
778 clk_enable_unlock(flags);
779
780 return ret;
781}
782EXPORT_SYMBOL_GPL(clk_enable);
783
784static int clk_core_round_rate_nolock(struct clk_core *core,
785 struct clk_rate_request *req)
786{
787 struct clk_core *parent;
788 long rate;
789
790 lockdep_assert_held(&prepare_lock);
791
792 if (!core)
793 return 0;
794
795 parent = core->parent;
796 if (parent) {
797 req->best_parent_hw = parent->hw;
798 req->best_parent_rate = parent->rate;
799 } else {
800 req->best_parent_hw = NULL;
801 req->best_parent_rate = 0;
802 }
803
804 if (core->ops->determine_rate) {
805 return core->ops->determine_rate(core->hw, req);
806 } else if (core->ops->round_rate) {
807 rate = core->ops->round_rate(core->hw, req->rate,
808 &req->best_parent_rate);
809 if (rate < 0)
810 return rate;
811
812 req->rate = rate;
813 } else if (core->flags & CLK_SET_RATE_PARENT) {
814 return clk_core_round_rate_nolock(parent, req);
815 } else {
816 req->rate = core->rate;
817 }
818
819 return 0;
820}
821
822/**
823 * __clk_determine_rate - get the closest rate actually supported by a clock
824 * @hw: determine the rate of this clock
825 * @rate: target rate
826 * @min_rate: returned rate must be greater than this rate
827 * @max_rate: returned rate must be less than this rate
828 *
829 * Useful for clk_ops such as .set_rate and .determine_rate.
830 */
831int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
832{
833 if (!hw) {
834 req->rate = 0;
835 return 0;
836 }
837
838 return clk_core_round_rate_nolock(hw->core, req);
839}
840EXPORT_SYMBOL_GPL(__clk_determine_rate);
841
842unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
843{
844 int ret;
845 struct clk_rate_request req;
846
847 clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate);
848 req.rate = rate;
849
850 ret = clk_core_round_rate_nolock(hw->core, &req);
851 if (ret)
852 return 0;
853
854 return req.rate;
855}
856EXPORT_SYMBOL_GPL(clk_hw_round_rate);
857
858/**
859 * clk_round_rate - round the given rate for a clk
860 * @clk: the clk for which we are rounding a rate
861 * @rate: the rate which is to be rounded
862 *
863 * Takes in a rate as input and rounds it to a rate that the clk can actually
864 * use which is then returned. If clk doesn't support round_rate operation
865 * then the parent rate is returned.
866 */
867long clk_round_rate(struct clk *clk, unsigned long rate)
868{
869 struct clk_rate_request req;
870 int ret;
871
872 if (!clk)
873 return 0;
874
875 clk_prepare_lock();
876
877 clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate);
878 req.rate = rate;
879
880 ret = clk_core_round_rate_nolock(clk->core, &req);
881 clk_prepare_unlock();
882
883 if (ret)
884 return ret;
885
886 return req.rate;
887}
888EXPORT_SYMBOL_GPL(clk_round_rate);
889
890/**
891 * __clk_notify - call clk notifier chain
892 * @core: clk that is changing rate
893 * @msg: clk notifier type (see include/linux/clk.h)
894 * @old_rate: old clk rate
895 * @new_rate: new clk rate
896 *
897 * Triggers a notifier call chain on the clk rate-change notification
898 * for 'clk'. Passes a pointer to the struct clk and the previous
899 * and current rates to the notifier callback. Intended to be called by
900 * internal clock code only. Returns NOTIFY_DONE from the last driver
901 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
902 * a driver returns that.
903 */
904static int __clk_notify(struct clk_core *core, unsigned long msg,
905 unsigned long old_rate, unsigned long new_rate)
906{
907 struct clk_notifier *cn;
908 struct clk_notifier_data cnd;
909 int ret = NOTIFY_DONE;
910
911 cnd.old_rate = old_rate;
912 cnd.new_rate = new_rate;
913
914 list_for_each_entry(cn, &clk_notifier_list, node) {
915 if (cn->clk->core == core) {
916 cnd.clk = cn->clk;
917 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
918 &cnd);
919 }
920 }
921
922 return ret;
923}
924
925/**
926 * __clk_recalc_accuracies
927 * @core: first clk in the subtree
928 *
929 * Walks the subtree of clks starting with clk and recalculates accuracies as
930 * it goes. Note that if a clk does not implement the .recalc_accuracy
931 * callback then it is assumed that the clock will take on the accuracy of its
932 * parent.
933 */
934static void __clk_recalc_accuracies(struct clk_core *core)
935{
936 unsigned long parent_accuracy = 0;
937 struct clk_core *child;
938
939 lockdep_assert_held(&prepare_lock);
940
941 if (core->parent)
942 parent_accuracy = core->parent->accuracy;
943
944 if (core->ops->recalc_accuracy)
945 core->accuracy = core->ops->recalc_accuracy(core->hw,
946 parent_accuracy);
947 else
948 core->accuracy = parent_accuracy;
949
950 hlist_for_each_entry(child, &core->children, child_node)
951 __clk_recalc_accuracies(child);
952}
953
954static long clk_core_get_accuracy(struct clk_core *core)
955{
956 unsigned long accuracy;
957
958 clk_prepare_lock();
959 if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
960 __clk_recalc_accuracies(core);
961
962 accuracy = __clk_get_accuracy(core);
963 clk_prepare_unlock();
964
965 return accuracy;
966}
967
968/**
969 * clk_get_accuracy - return the accuracy of clk
970 * @clk: the clk whose accuracy is being returned
971 *
972 * Simply returns the cached accuracy of the clk, unless
973 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
974 * issued.
975 * If clk is NULL then returns 0.
976 */
977long clk_get_accuracy(struct clk *clk)
978{
979 if (!clk)
980 return 0;
981
982 return clk_core_get_accuracy(clk->core);
983}
984EXPORT_SYMBOL_GPL(clk_get_accuracy);
985
986static unsigned long clk_recalc(struct clk_core *core,
987 unsigned long parent_rate)
988{
989 if (core->ops->recalc_rate)
990 return core->ops->recalc_rate(core->hw, parent_rate);
991 return parent_rate;
992}
993
994/**
995 * __clk_recalc_rates
996 * @core: first clk in the subtree
997 * @msg: notification type (see include/linux/clk.h)
998 *
999 * Walks the subtree of clks starting with clk and recalculates rates as it
1000 * goes. Note that if a clk does not implement the .recalc_rate callback then
1001 * it is assumed that the clock will take on the rate of its parent.
1002 *
1003 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1004 * if necessary.
1005 */
1006static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
1007{
1008 unsigned long old_rate;
1009 unsigned long parent_rate = 0;
1010 struct clk_core *child;
1011
1012 lockdep_assert_held(&prepare_lock);
1013
1014 old_rate = core->rate;
1015
1016 if (core->parent)
1017 parent_rate = core->parent->rate;
1018
1019 core->rate = clk_recalc(core, parent_rate);
1020
1021 /*
1022 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1023 * & ABORT_RATE_CHANGE notifiers
1024 */
1025 if (core->notifier_count && msg)
1026 __clk_notify(core, msg, old_rate, core->rate);
1027
1028 hlist_for_each_entry(child, &core->children, child_node)
1029 __clk_recalc_rates(child, msg);
1030}
1031
1032static unsigned long clk_core_get_rate(struct clk_core *core)
1033{
1034 unsigned long rate;
1035
1036 clk_prepare_lock();
1037
1038 if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1039 __clk_recalc_rates(core, 0);
1040
1041 rate = clk_core_get_rate_nolock(core);
1042 clk_prepare_unlock();
1043
1044 return rate;
1045}
1046
1047/**
1048 * clk_get_rate - return the rate of clk
1049 * @clk: the clk whose rate is being returned
1050 *
1051 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1052 * is set, which means a recalc_rate will be issued.
1053 * If clk is NULL then returns 0.
1054 */
1055unsigned long clk_get_rate(struct clk *clk)
1056{
1057 if (!clk)
1058 return 0;
1059
1060 return clk_core_get_rate(clk->core);
1061}
1062EXPORT_SYMBOL_GPL(clk_get_rate);
1063
1064static int clk_fetch_parent_index(struct clk_core *core,
1065 struct clk_core *parent)
1066{
1067 int i;
1068
1069 if (!parent)
1070 return -EINVAL;
1071
1072 for (i = 0; i < core->num_parents; i++)
1073 if (clk_core_get_parent_by_index(core, i) == parent)
1074 return i;
1075
1076 return -EINVAL;
1077}
1078
1079/*
1080 * Update the orphan status of @core and all its children.
1081 */
1082static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
1083{
1084 struct clk_core *child;
1085
1086 core->orphan = is_orphan;
1087
1088 hlist_for_each_entry(child, &core->children, child_node)
1089 clk_core_update_orphan_status(child, is_orphan);
1090}
1091
1092static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
1093{
1094 bool was_orphan = core->orphan;
1095
1096 hlist_del(&core->child_node);
1097
1098 if (new_parent) {
1099 bool becomes_orphan = new_parent->orphan;
1100
1101 /* avoid duplicate POST_RATE_CHANGE notifications */
1102 if (new_parent->new_child == core)
1103 new_parent->new_child = NULL;
1104
1105 hlist_add_head(&core->child_node, &new_parent->children);
1106
1107 if (was_orphan != becomes_orphan)
1108 clk_core_update_orphan_status(core, becomes_orphan);
1109 } else {
1110 hlist_add_head(&core->child_node, &clk_orphan_list);
1111 if (!was_orphan)
1112 clk_core_update_orphan_status(core, true);
1113 }
1114
1115 core->parent = new_parent;
1116}
1117
1118static struct clk_core *__clk_set_parent_before(struct clk_core *core,
1119 struct clk_core *parent)
1120{
1121 unsigned long flags;
1122 struct clk_core *old_parent = core->parent;
1123
1124 /*
1125 * Migrate prepare state between parents and prevent race with
1126 * clk_enable().
1127 *
1128 * If the clock is not prepared, then a race with
1129 * clk_enable/disable() is impossible since we already have the
1130 * prepare lock (future calls to clk_enable() need to be preceded by
1131 * a clk_prepare()).
1132 *
1133 * If the clock is prepared, migrate the prepared state to the new
1134 * parent and also protect against a race with clk_enable() by
1135 * forcing the clock and the new parent on. This ensures that all
1136 * future calls to clk_enable() are practically NOPs with respect to
1137 * hardware and software states.
1138 *
1139 * See also: Comment for clk_set_parent() below.
1140 */
1141 if (core->prepare_count) {
1142 clk_core_prepare(parent);
1143 flags = clk_enable_lock();
1144 clk_core_enable(parent);
1145 clk_core_enable(core);
1146 clk_enable_unlock(flags);
1147 }
1148
1149 /* update the clk tree topology */
1150 flags = clk_enable_lock();
1151 clk_reparent(core, parent);
1152 clk_enable_unlock(flags);
1153
1154 return old_parent;
1155}
1156
1157static void __clk_set_parent_after(struct clk_core *core,
1158 struct clk_core *parent,
1159 struct clk_core *old_parent)
1160{
1161 unsigned long flags;
1162
1163 /*
1164 * Finish the migration of prepare state and undo the changes done
1165 * for preventing a race with clk_enable().
1166 */
1167 if (core->prepare_count) {
1168 flags = clk_enable_lock();
1169 clk_core_disable(core);
1170 clk_core_disable(old_parent);
1171 clk_enable_unlock(flags);
1172 clk_core_unprepare(old_parent);
1173 }
1174}
1175
1176static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
1177 u8 p_index)
1178{
1179 unsigned long flags;
1180 int ret = 0;
1181 struct clk_core *old_parent;
1182
1183 old_parent = __clk_set_parent_before(core, parent);
1184
1185 trace_clk_set_parent(core, parent);
1186
1187 /* change clock input source */
1188 if (parent && core->ops->set_parent)
1189 ret = core->ops->set_parent(core->hw, p_index);
1190
1191 trace_clk_set_parent_complete(core, parent);
1192
1193 if (ret) {
1194 flags = clk_enable_lock();
1195 clk_reparent(core, old_parent);
1196 clk_enable_unlock(flags);
1197 __clk_set_parent_after(core, old_parent, parent);
1198
1199 return ret;
1200 }
1201
1202 __clk_set_parent_after(core, parent, old_parent);
1203
1204 return 0;
1205}
1206
1207/**
1208 * __clk_speculate_rates
1209 * @core: first clk in the subtree
1210 * @parent_rate: the "future" rate of clk's parent
1211 *
1212 * Walks the subtree of clks starting with clk, speculating rates as it
1213 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1214 *
1215 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1216 * pre-rate change notifications and returns early if no clks in the
1217 * subtree have subscribed to the notifications. Note that if a clk does not
1218 * implement the .recalc_rate callback then it is assumed that the clock will
1219 * take on the rate of its parent.
1220 */
1221static int __clk_speculate_rates(struct clk_core *core,
1222 unsigned long parent_rate)
1223{
1224 struct clk_core *child;
1225 unsigned long new_rate;
1226 int ret = NOTIFY_DONE;
1227
1228 lockdep_assert_held(&prepare_lock);
1229
1230 new_rate = clk_recalc(core, parent_rate);
1231
1232 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
1233 if (core->notifier_count)
1234 ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
1235
1236 if (ret & NOTIFY_STOP_MASK) {
1237 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1238 __func__, core->name, ret);
1239 goto out;
1240 }
1241
1242 hlist_for_each_entry(child, &core->children, child_node) {
1243 ret = __clk_speculate_rates(child, new_rate);
1244 if (ret & NOTIFY_STOP_MASK)
1245 break;
1246 }
1247
1248out:
1249 return ret;
1250}
1251
1252static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
1253 struct clk_core *new_parent, u8 p_index)
1254{
1255 struct clk_core *child;
1256
1257 core->new_rate = new_rate;
1258 core->new_parent = new_parent;
1259 core->new_parent_index = p_index;
1260 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1261 core->new_child = NULL;
1262 if (new_parent && new_parent != core->parent)
1263 new_parent->new_child = core;
1264
1265 hlist_for_each_entry(child, &core->children, child_node) {
1266 child->new_rate = clk_recalc(child, new_rate);
1267 clk_calc_subtree(child, child->new_rate, NULL, 0);
1268 }
1269}
1270
1271/*
1272 * calculate the new rates returning the topmost clock that has to be
1273 * changed.
1274 */
1275static struct clk_core *clk_calc_new_rates(struct clk_core *core,
1276 unsigned long rate)
1277{
1278 struct clk_core *top = core;
1279 struct clk_core *old_parent, *parent;
1280 unsigned long best_parent_rate = 0;
1281 unsigned long new_rate;
1282 unsigned long min_rate;
1283 unsigned long max_rate;
1284 int p_index = 0;
1285 long ret;
1286
1287 /* sanity */
1288 if (IS_ERR_OR_NULL(core))
1289 return NULL;
1290
1291 /* save parent rate, if it exists */
1292 parent = old_parent = core->parent;
1293 if (parent)
1294 best_parent_rate = parent->rate;
1295
1296 clk_core_get_boundaries(core, &min_rate, &max_rate);
1297
1298 /* find the closest rate and parent clk/rate */
1299 if (core->ops->determine_rate) {
1300 struct clk_rate_request req;
1301
1302 req.rate = rate;
1303 req.min_rate = min_rate;
1304 req.max_rate = max_rate;
1305 if (parent) {
1306 req.best_parent_hw = parent->hw;
1307 req.best_parent_rate = parent->rate;
1308 } else {
1309 req.best_parent_hw = NULL;
1310 req.best_parent_rate = 0;
1311 }
1312
1313 ret = core->ops->determine_rate(core->hw, &req);
1314 if (ret < 0)
1315 return NULL;
1316
1317 best_parent_rate = req.best_parent_rate;
1318 new_rate = req.rate;
1319 parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
1320 } else if (core->ops->round_rate) {
1321 ret = core->ops->round_rate(core->hw, rate,
1322 &best_parent_rate);
1323 if (ret < 0)
1324 return NULL;
1325
1326 new_rate = ret;
1327 if (new_rate < min_rate || new_rate > max_rate)
1328 return NULL;
1329 } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
1330 /* pass-through clock without adjustable parent */
1331 core->new_rate = core->rate;
1332 return NULL;
1333 } else {
1334 /* pass-through clock with adjustable parent */
1335 top = clk_calc_new_rates(parent, rate);
1336 new_rate = parent->new_rate;
1337 goto out;
1338 }
1339
1340 /* some clocks must be gated to change parent */
1341 if (parent != old_parent &&
1342 (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1343 pr_debug("%s: %s not gated but wants to reparent\n",
1344 __func__, core->name);
1345 return NULL;
1346 }
1347
1348 /* try finding the new parent index */
1349 if (parent && core->num_parents > 1) {
1350 p_index = clk_fetch_parent_index(core, parent);
1351 if (p_index < 0) {
1352 pr_debug("%s: clk %s can not be parent of clk %s\n",
1353 __func__, parent->name, core->name);
1354 return NULL;
1355 }
1356 }
1357
1358 if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
1359 best_parent_rate != parent->rate)
1360 top = clk_calc_new_rates(parent, best_parent_rate);
1361
1362out:
1363 clk_calc_subtree(core, new_rate, parent, p_index);
1364
1365 return top;
1366}
1367
1368/*
1369 * Notify about rate changes in a subtree. Always walk down the whole tree
1370 * so that in case of an error we can walk down the whole tree again and
1371 * abort the change.
1372 */
1373static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
1374 unsigned long event)
1375{
1376 struct clk_core *child, *tmp_clk, *fail_clk = NULL;
1377 int ret = NOTIFY_DONE;
1378
1379 if (core->rate == core->new_rate)
1380 return NULL;
1381
1382 if (core->notifier_count) {
1383 ret = __clk_notify(core, event, core->rate, core->new_rate);
1384 if (ret & NOTIFY_STOP_MASK)
1385 fail_clk = core;
1386 }
1387
1388 hlist_for_each_entry(child, &core->children, child_node) {
1389 /* Skip children who will be reparented to another clock */
1390 if (child->new_parent && child->new_parent != core)
1391 continue;
1392 tmp_clk = clk_propagate_rate_change(child, event);
1393 if (tmp_clk)
1394 fail_clk = tmp_clk;
1395 }
1396
1397 /* handle the new child who might not be in core->children yet */
1398 if (core->new_child) {
1399 tmp_clk = clk_propagate_rate_change(core->new_child, event);
1400 if (tmp_clk)
1401 fail_clk = tmp_clk;
1402 }
1403
1404 return fail_clk;
1405}
1406
1407/*
1408 * walk down a subtree and set the new rates notifying the rate
1409 * change on the way
1410 */
1411static void clk_change_rate(struct clk_core *core)
1412{
1413 struct clk_core *child;
1414 struct hlist_node *tmp;
1415 unsigned long old_rate;
1416 unsigned long best_parent_rate = 0;
1417 bool skip_set_rate = false;
1418 struct clk_core *old_parent;
1419
1420 old_rate = core->rate;
1421
1422 if (core->new_parent)
1423 best_parent_rate = core->new_parent->rate;
1424 else if (core->parent)
1425 best_parent_rate = core->parent->rate;
1426
1427 if (core->flags & CLK_SET_RATE_UNGATE) {
1428 unsigned long flags;
1429
1430 clk_core_prepare(core);
1431 flags = clk_enable_lock();
1432 clk_core_enable(core);
1433 clk_enable_unlock(flags);
1434 }
1435
1436 if (core->new_parent && core->new_parent != core->parent) {
1437 old_parent = __clk_set_parent_before(core, core->new_parent);
1438 trace_clk_set_parent(core, core->new_parent);
1439
1440 if (core->ops->set_rate_and_parent) {
1441 skip_set_rate = true;
1442 core->ops->set_rate_and_parent(core->hw, core->new_rate,
1443 best_parent_rate,
1444 core->new_parent_index);
1445 } else if (core->ops->set_parent) {
1446 core->ops->set_parent(core->hw, core->new_parent_index);
1447 }
1448
1449 trace_clk_set_parent_complete(core, core->new_parent);
1450 __clk_set_parent_after(core, core->new_parent, old_parent);
1451 }
1452
1453 trace_clk_set_rate(core, core->new_rate);
1454
1455 if (!skip_set_rate && core->ops->set_rate)
1456 core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
1457
1458 trace_clk_set_rate_complete(core, core->new_rate);
1459
1460 core->rate = clk_recalc(core, best_parent_rate);
1461
1462 if (core->flags & CLK_SET_RATE_UNGATE) {
1463 unsigned long flags;
1464
1465 flags = clk_enable_lock();
1466 clk_core_disable(core);
1467 clk_enable_unlock(flags);
1468 clk_core_unprepare(core);
1469 }
1470
1471 if (core->notifier_count && old_rate != core->rate)
1472 __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
1473
1474 if (core->flags & CLK_RECALC_NEW_RATES)
1475 (void)clk_calc_new_rates(core, core->new_rate);
1476
1477 /*
1478 * Use safe iteration, as change_rate can actually swap parents
1479 * for certain clock types.
1480 */
1481 hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
1482 /* Skip children who will be reparented to another clock */
1483 if (child->new_parent && child->new_parent != core)
1484 continue;
1485 clk_change_rate(child);
1486 }
1487
1488 /* handle the new child who might not be in core->children yet */
1489 if (core->new_child)
1490 clk_change_rate(core->new_child);
1491}
1492
1493static int clk_core_set_rate_nolock(struct clk_core *core,
1494 unsigned long req_rate)
1495{
1496 struct clk_core *top, *fail_clk;
1497 unsigned long rate = req_rate;
1498 int ret = 0;
1499
1500 if (!core)
1501 return 0;
1502
1503 /* bail early if nothing to do */
1504 if (rate == clk_core_get_rate_nolock(core))
1505 return 0;
1506
1507 if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
1508 return -EBUSY;
1509
1510 /* calculate new rates and get the topmost changed clock */
1511 top = clk_calc_new_rates(core, rate);
1512 if (!top)
1513 return -EINVAL;
1514
1515 /* notify that we are about to change rates */
1516 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1517 if (fail_clk) {
1518 pr_debug("%s: failed to set %s rate\n", __func__,
1519 fail_clk->name);
1520 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1521 return -EBUSY;
1522 }
1523
1524 /* change the rates */
1525 clk_change_rate(top);
1526
1527 core->req_rate = req_rate;
1528
1529 return ret;
1530}
1531
1532/**
1533 * clk_set_rate - specify a new rate for clk
1534 * @clk: the clk whose rate is being changed
1535 * @rate: the new rate for clk
1536 *
1537 * In the simplest case clk_set_rate will only adjust the rate of clk.
1538 *
1539 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1540 * propagate up to clk's parent; whether or not this happens depends on the
1541 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1542 * after calling .round_rate then upstream parent propagation is ignored. If
1543 * *parent_rate comes back with a new rate for clk's parent then we propagate
1544 * up to clk's parent and set its rate. Upward propagation will continue
1545 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1546 * .round_rate stops requesting changes to clk's parent_rate.
1547 *
1548 * Rate changes are accomplished via tree traversal that also recalculates the
1549 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
1550 *
1551 * Returns 0 on success, -EERROR otherwise.
1552 */
1553int clk_set_rate(struct clk *clk, unsigned long rate)
1554{
1555 int ret;
1556
1557 if (!clk)
1558 return 0;
1559
1560 /* prevent racing with updates to the clock topology */
1561 clk_prepare_lock();
1562
1563 ret = clk_core_set_rate_nolock(clk->core, rate);
1564
1565 clk_prepare_unlock();
1566
1567 return ret;
1568}
1569EXPORT_SYMBOL_GPL(clk_set_rate);
1570
1571/**
1572 * clk_set_rate_range - set a rate range for a clock source
1573 * @clk: clock source
1574 * @min: desired minimum clock rate in Hz, inclusive
1575 * @max: desired maximum clock rate in Hz, inclusive
1576 *
1577 * Returns success (0) or negative errno.
1578 */
1579int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
1580{
1581 int ret = 0;
1582
1583 if (!clk)
1584 return 0;
1585
1586 if (min > max) {
1587 pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
1588 __func__, clk->core->name, clk->dev_id, clk->con_id,
1589 min, max);
1590 return -EINVAL;
1591 }
1592
1593 clk_prepare_lock();
1594
1595 if (min != clk->min_rate || max != clk->max_rate) {
1596 clk->min_rate = min;
1597 clk->max_rate = max;
1598 ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
1599 }
1600
1601 clk_prepare_unlock();
1602
1603 return ret;
1604}
1605EXPORT_SYMBOL_GPL(clk_set_rate_range);
1606
1607/**
1608 * clk_set_min_rate - set a minimum clock rate for a clock source
1609 * @clk: clock source
1610 * @rate: desired minimum clock rate in Hz, inclusive
1611 *
1612 * Returns success (0) or negative errno.
1613 */
1614int clk_set_min_rate(struct clk *clk, unsigned long rate)
1615{
1616 if (!clk)
1617 return 0;
1618
1619 return clk_set_rate_range(clk, rate, clk->max_rate);
1620}
1621EXPORT_SYMBOL_GPL(clk_set_min_rate);
1622
1623/**
1624 * clk_set_max_rate - set a maximum clock rate for a clock source
1625 * @clk: clock source
1626 * @rate: desired maximum clock rate in Hz, inclusive
1627 *
1628 * Returns success (0) or negative errno.
1629 */
1630int clk_set_max_rate(struct clk *clk, unsigned long rate)
1631{
1632 if (!clk)
1633 return 0;
1634
1635 return clk_set_rate_range(clk, clk->min_rate, rate);
1636}
1637EXPORT_SYMBOL_GPL(clk_set_max_rate);
1638
1639/**
1640 * clk_get_parent - return the parent of a clk
1641 * @clk: the clk whose parent gets returned
1642 *
1643 * Simply returns clk->parent. Returns NULL if clk is NULL.
1644 */
1645struct clk *clk_get_parent(struct clk *clk)
1646{
1647 struct clk *parent;
1648
1649 if (!clk)
1650 return NULL;
1651
1652 clk_prepare_lock();
1653 /* TODO: Create a per-user clk and change callers to call clk_put */
1654 parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
1655 clk_prepare_unlock();
1656
1657 return parent;
1658}
1659EXPORT_SYMBOL_GPL(clk_get_parent);
1660
1661static struct clk_core *__clk_init_parent(struct clk_core *core)
1662{
1663 u8 index = 0;
1664
1665 if (core->num_parents > 1 && core->ops->get_parent)
1666 index = core->ops->get_parent(core->hw);
1667
1668 return clk_core_get_parent_by_index(core, index);
1669}
1670
1671static void clk_core_reparent(struct clk_core *core,
1672 struct clk_core *new_parent)
1673{
1674 clk_reparent(core, new_parent);
1675 __clk_recalc_accuracies(core);
1676 __clk_recalc_rates(core, POST_RATE_CHANGE);
1677}
1678
1679void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
1680{
1681 if (!hw)
1682 return;
1683
1684 clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
1685}
1686
1687/**
1688 * clk_has_parent - check if a clock is a possible parent for another
1689 * @clk: clock source
1690 * @parent: parent clock source
1691 *
1692 * This function can be used in drivers that need to check that a clock can be
1693 * the parent of another without actually changing the parent.
1694 *
1695 * Returns true if @parent is a possible parent for @clk, false otherwise.
1696 */
1697bool clk_has_parent(struct clk *clk, struct clk *parent)
1698{
1699 struct clk_core *core, *parent_core;
1700 unsigned int i;
1701
1702 /* NULL clocks should be nops, so return success if either is NULL. */
1703 if (!clk || !parent)
1704 return true;
1705
1706 core = clk->core;
1707 parent_core = parent->core;
1708
1709 /* Optimize for the case where the parent is already the parent. */
1710 if (core->parent == parent_core)
1711 return true;
1712
1713 for (i = 0; i < core->num_parents; i++)
1714 if (strcmp(core->parent_names[i], parent_core->name) == 0)
1715 return true;
1716
1717 return false;
1718}
1719EXPORT_SYMBOL_GPL(clk_has_parent);
1720
1721static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
1722{
1723 int ret = 0;
1724 int p_index = 0;
1725 unsigned long p_rate = 0;
1726
1727 if (!core)
1728 return 0;
1729
1730 /* prevent racing with updates to the clock topology */
1731 clk_prepare_lock();
1732
1733 if (core->parent == parent)
1734 goto out;
1735
1736 /* verify ops for for multi-parent clks */
1737 if ((core->num_parents > 1) && (!core->ops->set_parent)) {
1738 ret = -ENOSYS;
1739 goto out;
1740 }
1741
1742 /* check that we are allowed to re-parent if the clock is in use */
1743 if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
1744 ret = -EBUSY;
1745 goto out;
1746 }
1747
1748 /* try finding the new parent index */
1749 if (parent) {
1750 p_index = clk_fetch_parent_index(core, parent);
1751 if (p_index < 0) {
1752 pr_debug("%s: clk %s can not be parent of clk %s\n",
1753 __func__, parent->name, core->name);
1754 ret = p_index;
1755 goto out;
1756 }
1757 p_rate = parent->rate;
1758 }
1759
1760 /* propagate PRE_RATE_CHANGE notifications */
1761 ret = __clk_speculate_rates(core, p_rate);
1762
1763 /* abort if a driver objects */
1764 if (ret & NOTIFY_STOP_MASK)
1765 goto out;
1766
1767 /* do the re-parent */
1768 ret = __clk_set_parent(core, parent, p_index);
1769
1770 /* propagate rate an accuracy recalculation accordingly */
1771 if (ret) {
1772 __clk_recalc_rates(core, ABORT_RATE_CHANGE);
1773 } else {
1774 __clk_recalc_rates(core, POST_RATE_CHANGE);
1775 __clk_recalc_accuracies(core);
1776 }
1777
1778out:
1779 clk_prepare_unlock();
1780
1781 return ret;
1782}
1783
1784/**
1785 * clk_set_parent - switch the parent of a mux clk
1786 * @clk: the mux clk whose input we are switching
1787 * @parent: the new input to clk
1788 *
1789 * Re-parent clk to use parent as its new input source. If clk is in
1790 * prepared state, the clk will get enabled for the duration of this call. If
1791 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1792 * that, the reparenting is glitchy in hardware, etc), use the
1793 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1794 *
1795 * After successfully changing clk's parent clk_set_parent will update the
1796 * clk topology, sysfs topology and propagate rate recalculation via
1797 * __clk_recalc_rates.
1798 *
1799 * Returns 0 on success, -EERROR otherwise.
1800 */
1801int clk_set_parent(struct clk *clk, struct clk *parent)
1802{
1803 if (!clk)
1804 return 0;
1805
1806 return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
1807}
1808EXPORT_SYMBOL_GPL(clk_set_parent);
1809
1810/**
1811 * clk_set_phase - adjust the phase shift of a clock signal
1812 * @clk: clock signal source
1813 * @degrees: number of degrees the signal is shifted
1814 *
1815 * Shifts the phase of a clock signal by the specified
1816 * degrees. Returns 0 on success, -EERROR otherwise.
1817 *
1818 * This function makes no distinction about the input or reference
1819 * signal that we adjust the clock signal phase against. For example
1820 * phase locked-loop clock signal generators we may shift phase with
1821 * respect to feedback clock signal input, but for other cases the
1822 * clock phase may be shifted with respect to some other, unspecified
1823 * signal.
1824 *
1825 * Additionally the concept of phase shift does not propagate through
1826 * the clock tree hierarchy, which sets it apart from clock rates and
1827 * clock accuracy. A parent clock phase attribute does not have an
1828 * impact on the phase attribute of a child clock.
1829 */
1830int clk_set_phase(struct clk *clk, int degrees)
1831{
1832 int ret = -EINVAL;
1833
1834 if (!clk)
1835 return 0;
1836
1837 /* sanity check degrees */
1838 degrees %= 360;
1839 if (degrees < 0)
1840 degrees += 360;
1841
1842 clk_prepare_lock();
1843
1844 /* bail early if nothing to do */
1845 if (degrees == clk->core->phase)
1846 goto out;
1847
1848 trace_clk_set_phase(clk->core, degrees);
1849
1850 if (clk->core->ops->set_phase)
1851 ret = clk->core->ops->set_phase(clk->core->hw, degrees);
1852
1853 trace_clk_set_phase_complete(clk->core, degrees);
1854
1855 if (!ret)
1856 clk->core->phase = degrees;
1857
1858out:
1859 clk_prepare_unlock();
1860
1861 return ret;
1862}
1863EXPORT_SYMBOL_GPL(clk_set_phase);
1864
1865static int clk_core_get_phase(struct clk_core *core)
1866{
1867 int ret;
1868
1869 clk_prepare_lock();
1870 ret = core->phase;
1871 clk_prepare_unlock();
1872
1873 return ret;
1874}
1875
1876/**
1877 * clk_get_phase - return the phase shift of a clock signal
1878 * @clk: clock signal source
1879 *
1880 * Returns the phase shift of a clock node in degrees, otherwise returns
1881 * -EERROR.
1882 */
1883int clk_get_phase(struct clk *clk)
1884{
1885 if (!clk)
1886 return 0;
1887
1888 return clk_core_get_phase(clk->core);
1889}
1890EXPORT_SYMBOL_GPL(clk_get_phase);
1891
1892/**
1893 * clk_is_match - check if two clk's point to the same hardware clock
1894 * @p: clk compared against q
1895 * @q: clk compared against p
1896 *
1897 * Returns true if the two struct clk pointers both point to the same hardware
1898 * clock node. Put differently, returns true if struct clk *p and struct clk *q
1899 * share the same struct clk_core object.
1900 *
1901 * Returns false otherwise. Note that two NULL clks are treated as matching.
1902 */
1903bool clk_is_match(const struct clk *p, const struct clk *q)
1904{
1905 /* trivial case: identical struct clk's or both NULL */
1906 if (p == q)
1907 return true;
1908
1909 /* true if clk->core pointers match. Avoid dereferencing garbage */
1910 if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
1911 if (p->core == q->core)
1912 return true;
1913
1914 return false;
1915}
1916EXPORT_SYMBOL_GPL(clk_is_match);
1917
1918/*** debugfs support ***/
1919
1920#ifdef CONFIG_DEBUG_FS
1921#include <linux/debugfs.h>
1922
1923static struct dentry *rootdir;
1924static int inited = 0;
1925static DEFINE_MUTEX(clk_debug_lock);
1926static HLIST_HEAD(clk_debug_list);
1927
1928static struct hlist_head *all_lists[] = {
1929 &clk_root_list,
1930 &clk_orphan_list,
1931 NULL,
1932};
1933
1934static struct hlist_head *orphan_list[] = {
1935 &clk_orphan_list,
1936 NULL,
1937};
1938
1939static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
1940 int level)
1941{
1942 if (!c)
1943 return;
1944
1945 seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n",
1946 level * 3 + 1, "",
1947 30 - level * 3, c->name,
1948 c->enable_count, c->prepare_count, clk_core_get_rate(c),
1949 clk_core_get_accuracy(c), clk_core_get_phase(c));
1950}
1951
1952static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
1953 int level)
1954{
1955 struct clk_core *child;
1956
1957 if (!c)
1958 return;
1959
1960 clk_summary_show_one(s, c, level);
1961
1962 hlist_for_each_entry(child, &c->children, child_node)
1963 clk_summary_show_subtree(s, child, level + 1);
1964}
1965
1966static int clk_summary_show(struct seq_file *s, void *data)
1967{
1968 struct clk_core *c;
1969 struct hlist_head **lists = (struct hlist_head **)s->private;
1970
1971 seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
1972 seq_puts(s, "----------------------------------------------------------------------------------------\n");
1973
1974 clk_prepare_lock();
1975
1976 for (; *lists; lists++)
1977 hlist_for_each_entry(c, *lists, child_node)
1978 clk_summary_show_subtree(s, c, 0);
1979
1980 clk_prepare_unlock();
1981
1982 return 0;
1983}
1984
1985
1986static int clk_summary_open(struct inode *inode, struct file *file)
1987{
1988 return single_open(file, clk_summary_show, inode->i_private);
1989}
1990
1991static const struct file_operations clk_summary_fops = {
1992 .open = clk_summary_open,
1993 .read = seq_read,
1994 .llseek = seq_lseek,
1995 .release = single_release,
1996};
1997
1998static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
1999{
2000 if (!c)
2001 return;
2002
2003 /* This should be JSON format, i.e. elements separated with a comma */
2004 seq_printf(s, "\"%s\": { ", c->name);
2005 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
2006 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
2007 seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c));
2008 seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c));
2009 seq_printf(s, "\"phase\": %d", clk_core_get_phase(c));
2010}
2011
2012static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
2013{
2014 struct clk_core *child;
2015
2016 if (!c)
2017 return;
2018
2019 clk_dump_one(s, c, level);
2020
2021 hlist_for_each_entry(child, &c->children, child_node) {
2022 seq_printf(s, ",");
2023 clk_dump_subtree(s, child, level + 1);
2024 }
2025
2026 seq_printf(s, "}");
2027}
2028
2029static int clk_dump(struct seq_file *s, void *data)
2030{
2031 struct clk_core *c;
2032 bool first_node = true;
2033 struct hlist_head **lists = (struct hlist_head **)s->private;
2034
2035 seq_printf(s, "{");
2036
2037 clk_prepare_lock();
2038
2039 for (; *lists; lists++) {
2040 hlist_for_each_entry(c, *lists, child_node) {
2041 if (!first_node)
2042 seq_puts(s, ",");
2043 first_node = false;
2044 clk_dump_subtree(s, c, 0);
2045 }
2046 }
2047
2048 clk_prepare_unlock();
2049
2050 seq_puts(s, "}\n");
2051 return 0;
2052}
2053
2054
2055static int clk_dump_open(struct inode *inode, struct file *file)
2056{
2057 return single_open(file, clk_dump, inode->i_private);
2058}
2059
2060static const struct file_operations clk_dump_fops = {
2061 .open = clk_dump_open,
2062 .read = seq_read,
2063 .llseek = seq_lseek,
2064 .release = single_release,
2065};
2066
2067static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
2068{
2069 struct dentry *d;
2070 int ret = -ENOMEM;
2071
2072 if (!core || !pdentry) {
2073 ret = -EINVAL;
2074 goto out;
2075 }
2076
2077 d = debugfs_create_dir(core->name, pdentry);
2078 if (!d)
2079 goto out;
2080
2081 core->dentry = d;
2082
2083 d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry,
2084 (u32 *)&core->rate);
2085 if (!d)
2086 goto err_out;
2087
2088 d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry,
2089 (u32 *)&core->accuracy);
2090 if (!d)
2091 goto err_out;
2092
2093 d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
2094 (u32 *)&core->phase);
2095 if (!d)
2096 goto err_out;
2097
2098 d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
2099 (u32 *)&core->flags);
2100 if (!d)
2101 goto err_out;
2102
2103 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
2104 (u32 *)&core->prepare_count);
2105 if (!d)
2106 goto err_out;
2107
2108 d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
2109 (u32 *)&core->enable_count);
2110 if (!d)
2111 goto err_out;
2112
2113 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
2114 (u32 *)&core->notifier_count);
2115 if (!d)
2116 goto err_out;
2117
2118 if (core->ops->debug_init) {
2119 ret = core->ops->debug_init(core->hw, core->dentry);
2120 if (ret)
2121 goto err_out;
2122 }
2123
2124 ret = 0;
2125 goto out;
2126
2127err_out:
2128 debugfs_remove_recursive(core->dentry);
2129 core->dentry = NULL;
2130out:
2131 return ret;
2132}
2133
2134/**
2135 * clk_debug_register - add a clk node to the debugfs clk directory
2136 * @core: the clk being added to the debugfs clk directory
2137 *
2138 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
2139 * initialized. Otherwise it bails out early since the debugfs clk directory
2140 * will be created lazily by clk_debug_init as part of a late_initcall.
2141 */
2142static int clk_debug_register(struct clk_core *core)
2143{
2144 int ret = 0;
2145
2146 mutex_lock(&clk_debug_lock);
2147 hlist_add_head(&core->debug_node, &clk_debug_list);
2148
2149 if (!inited)
2150 goto unlock;
2151
2152 ret = clk_debug_create_one(core, rootdir);
2153unlock:
2154 mutex_unlock(&clk_debug_lock);
2155
2156 return ret;
2157}
2158
2159 /**
2160 * clk_debug_unregister - remove a clk node from the debugfs clk directory
2161 * @core: the clk being removed from the debugfs clk directory
2162 *
2163 * Dynamically removes a clk and all its child nodes from the
2164 * debugfs clk directory if clk->dentry points to debugfs created by
2165 * clk_debug_register in __clk_core_init.
2166 */
2167static void clk_debug_unregister(struct clk_core *core)
2168{
2169 mutex_lock(&clk_debug_lock);
2170 hlist_del_init(&core->debug_node);
2171 debugfs_remove_recursive(core->dentry);
2172 core->dentry = NULL;
2173 mutex_unlock(&clk_debug_lock);
2174}
2175
2176struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
2177 void *data, const struct file_operations *fops)
2178{
2179 struct dentry *d = NULL;
2180
2181 if (hw->core->dentry)
2182 d = debugfs_create_file(name, mode, hw->core->dentry, data,
2183 fops);
2184
2185 return d;
2186}
2187EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
2188
2189/**
2190 * clk_debug_init - lazily populate the debugfs clk directory
2191 *
2192 * clks are often initialized very early during boot before memory can be
2193 * dynamically allocated and well before debugfs is setup. This function
2194 * populates the debugfs clk directory once at boot-time when we know that
2195 * debugfs is setup. It should only be called once at boot-time, all other clks
2196 * added dynamically will be done so with clk_debug_register.
2197 */
2198static int __init clk_debug_init(void)
2199{
2200 struct clk_core *core;
2201 struct dentry *d;
2202
2203 rootdir = debugfs_create_dir("clk", NULL);
2204
2205 if (!rootdir)
2206 return -ENOMEM;
2207
2208 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
2209 &clk_summary_fops);
2210 if (!d)
2211 return -ENOMEM;
2212
2213 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
2214 &clk_dump_fops);
2215 if (!d)
2216 return -ENOMEM;
2217
2218 d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
2219 &orphan_list, &clk_summary_fops);
2220 if (!d)
2221 return -ENOMEM;
2222
2223 d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
2224 &orphan_list, &clk_dump_fops);
2225 if (!d)
2226 return -ENOMEM;
2227
2228 mutex_lock(&clk_debug_lock);
2229 hlist_for_each_entry(core, &clk_debug_list, debug_node)
2230 clk_debug_create_one(core, rootdir);
2231
2232 inited = 1;
2233 mutex_unlock(&clk_debug_lock);
2234
2235 return 0;
2236}
2237late_initcall(clk_debug_init);
2238#else
2239static inline int clk_debug_register(struct clk_core *core) { return 0; }
2240static inline void clk_debug_reparent(struct clk_core *core,
2241 struct clk_core *new_parent)
2242{
2243}
2244static inline void clk_debug_unregister(struct clk_core *core)
2245{
2246}
2247#endif
2248
2249/**
2250 * __clk_core_init - initialize the data structures in a struct clk_core
2251 * @core: clk_core being initialized
2252 *
2253 * Initializes the lists in struct clk_core, queries the hardware for the
2254 * parent and rate and sets them both.
2255 */
2256static int __clk_core_init(struct clk_core *core)
2257{
2258 int i, ret = 0;
2259 struct clk_core *orphan;
2260 struct hlist_node *tmp2;
2261 unsigned long rate;
2262
2263 if (!core)
2264 return -EINVAL;
2265
2266 clk_prepare_lock();
2267
2268 /* check to see if a clock with this name is already registered */
2269 if (clk_core_lookup(core->name)) {
2270 pr_debug("%s: clk %s already initialized\n",
2271 __func__, core->name);
2272 ret = -EEXIST;
2273 goto out;
2274 }
2275
2276 /* check that clk_ops are sane. See Documentation/clk.txt */
2277 if (core->ops->set_rate &&
2278 !((core->ops->round_rate || core->ops->determine_rate) &&
2279 core->ops->recalc_rate)) {
2280 pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
2281 __func__, core->name);
2282 ret = -EINVAL;
2283 goto out;
2284 }
2285
2286 if (core->ops->set_parent && !core->ops->get_parent) {
2287 pr_err("%s: %s must implement .get_parent & .set_parent\n",
2288 __func__, core->name);
2289 ret = -EINVAL;
2290 goto out;
2291 }
2292
2293 if (core->num_parents > 1 && !core->ops->get_parent) {
2294 pr_err("%s: %s must implement .get_parent as it has multi parents\n",
2295 __func__, core->name);
2296 ret = -EINVAL;
2297 goto out;
2298 }
2299
2300 if (core->ops->set_rate_and_parent &&
2301 !(core->ops->set_parent && core->ops->set_rate)) {
2302 pr_err("%s: %s must implement .set_parent & .set_rate\n",
2303 __func__, core->name);
2304 ret = -EINVAL;
2305 goto out;
2306 }
2307
2308 /* throw a WARN if any entries in parent_names are NULL */
2309 for (i = 0; i < core->num_parents; i++)
2310 WARN(!core->parent_names[i],
2311 "%s: invalid NULL in %s's .parent_names\n",
2312 __func__, core->name);
2313
2314 core->parent = __clk_init_parent(core);
2315
2316 /*
2317 * Populate core->parent if parent has already been clk_core_init'd. If
2318 * parent has not yet been clk_core_init'd then place clk in the orphan
2319 * list. If clk doesn't have any parents then place it in the root
2320 * clk list.
2321 *
2322 * Every time a new clk is clk_init'd then we walk the list of orphan
2323 * clocks and re-parent any that are children of the clock currently
2324 * being clk_init'd.
2325 */
2326 if (core->parent) {
2327 hlist_add_head(&core->child_node,
2328 &core->parent->children);
2329 core->orphan = core->parent->orphan;
2330 } else if (!core->num_parents) {
2331 hlist_add_head(&core->child_node, &clk_root_list);
2332 core->orphan = false;
2333 } else {
2334 hlist_add_head(&core->child_node, &clk_orphan_list);
2335 core->orphan = true;
2336 }
2337
2338 /*
2339 * Set clk's accuracy. The preferred method is to use
2340 * .recalc_accuracy. For simple clocks and lazy developers the default
2341 * fallback is to use the parent's accuracy. If a clock doesn't have a
2342 * parent (or is orphaned) then accuracy is set to zero (perfect
2343 * clock).
2344 */
2345 if (core->ops->recalc_accuracy)
2346 core->accuracy = core->ops->recalc_accuracy(core->hw,
2347 __clk_get_accuracy(core->parent));
2348 else if (core->parent)
2349 core->accuracy = core->parent->accuracy;
2350 else
2351 core->accuracy = 0;
2352
2353 /*
2354 * Set clk's phase.
2355 * Since a phase is by definition relative to its parent, just
2356 * query the current clock phase, or just assume it's in phase.
2357 */
2358 if (core->ops->get_phase)
2359 core->phase = core->ops->get_phase(core->hw);
2360 else
2361 core->phase = 0;
2362
2363 /*
2364 * Set clk's rate. The preferred method is to use .recalc_rate. For
2365 * simple clocks and lazy developers the default fallback is to use the
2366 * parent's rate. If a clock doesn't have a parent (or is orphaned)
2367 * then rate is set to zero.
2368 */
2369 if (core->ops->recalc_rate)
2370 rate = core->ops->recalc_rate(core->hw,
2371 clk_core_get_rate_nolock(core->parent));
2372 else if (core->parent)
2373 rate = core->parent->rate;
2374 else
2375 rate = 0;
2376 core->rate = core->req_rate = rate;
2377
2378 /*
2379 * walk the list of orphan clocks and reparent any that newly finds a
2380 * parent.
2381 */
2382 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
2383 struct clk_core *parent = __clk_init_parent(orphan);
2384
2385 if (parent)
2386 clk_core_reparent(orphan, parent);
2387 }
2388
2389 /*
2390 * optional platform-specific magic
2391 *
2392 * The .init callback is not used by any of the basic clock types, but
2393 * exists for weird hardware that must perform initialization magic.
2394 * Please consider other ways of solving initialization problems before
2395 * using this callback, as its use is discouraged.
2396 */
2397 if (core->ops->init)
2398 core->ops->init(core->hw);
2399
2400 kref_init(&core->ref);
2401out:
2402 clk_prepare_unlock();
2403
2404 if (!ret)
2405 clk_debug_register(core);
2406
2407 return ret;
2408}
2409
2410struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
2411 const char *con_id)
2412{
2413 struct clk *clk;
2414
2415 /* This is to allow this function to be chained to others */
2416 if (IS_ERR_OR_NULL(hw))
2417 return (struct clk *) hw;
2418
2419 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2420 if (!clk)
2421 return ERR_PTR(-ENOMEM);
2422
2423 clk->core = hw->core;
2424 clk->dev_id = dev_id;
2425 clk->con_id = con_id;
2426 clk->max_rate = ULONG_MAX;
2427
2428 clk_prepare_lock();
2429 hlist_add_head(&clk->clks_node, &hw->core->clks);
2430 clk_prepare_unlock();
2431
2432 return clk;
2433}
2434
2435void __clk_free_clk(struct clk *clk)
2436{
2437 clk_prepare_lock();
2438 hlist_del(&clk->clks_node);
2439 clk_prepare_unlock();
2440
2441 kfree(clk);
2442}
2443
2444/**
2445 * clk_register - allocate a new clock, register it and return an opaque cookie
2446 * @dev: device that is registering this clock
2447 * @hw: link to hardware-specific clock data
2448 *
2449 * clk_register is the primary interface for populating the clock tree with new
2450 * clock nodes. It returns a pointer to the newly allocated struct clk which
2451 * cannot be dereferenced by driver code but may be used in conjunction with the
2452 * rest of the clock API. In the event of an error clk_register will return an
2453 * error code; drivers must test for an error code after calling clk_register.
2454 */
2455struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2456{
2457 int i, ret;
2458 struct clk_core *core;
2459
2460 core = kzalloc(sizeof(*core), GFP_KERNEL);
2461 if (!core) {
2462 ret = -ENOMEM;
2463 goto fail_out;
2464 }
2465
2466 core->name = kstrdup_const(hw->init->name, GFP_KERNEL);
2467 if (!core->name) {
2468 ret = -ENOMEM;
2469 goto fail_name;
2470 }
2471 core->ops = hw->init->ops;
2472 if (dev && dev->driver)
2473 core->owner = dev->driver->owner;
2474 core->hw = hw;
2475 core->flags = hw->init->flags;
2476 core->num_parents = hw->init->num_parents;
2477 core->min_rate = 0;
2478 core->max_rate = ULONG_MAX;
2479 hw->core = core;
2480
2481 /* allocate local copy in case parent_names is __initdata */
2482 core->parent_names = kcalloc(core->num_parents, sizeof(char *),
2483 GFP_KERNEL);
2484
2485 if (!core->parent_names) {
2486 ret = -ENOMEM;
2487 goto fail_parent_names;
2488 }
2489
2490
2491 /* copy each string name in case parent_names is __initdata */
2492 for (i = 0; i < core->num_parents; i++) {
2493 core->parent_names[i] = kstrdup_const(hw->init->parent_names[i],
2494 GFP_KERNEL);
2495 if (!core->parent_names[i]) {
2496 ret = -ENOMEM;
2497 goto fail_parent_names_copy;
2498 }
2499 }
2500
2501 /* avoid unnecessary string look-ups of clk_core's possible parents. */
2502 core->parents = kcalloc(core->num_parents, sizeof(*core->parents),
2503 GFP_KERNEL);
2504 if (!core->parents) {
2505 ret = -ENOMEM;
2506 goto fail_parents;
2507 };
2508
2509 INIT_HLIST_HEAD(&core->clks);
2510
2511 hw->clk = __clk_create_clk(hw, NULL, NULL);
2512 if (IS_ERR(hw->clk)) {
2513 ret = PTR_ERR(hw->clk);
2514 goto fail_parents;
2515 }
2516
2517 ret = __clk_core_init(core);
2518 if (!ret)
2519 return hw->clk;
2520
2521 __clk_free_clk(hw->clk);
2522 hw->clk = NULL;
2523
2524fail_parents:
2525 kfree(core->parents);
2526fail_parent_names_copy:
2527 while (--i >= 0)
2528 kfree_const(core->parent_names[i]);
2529 kfree(core->parent_names);
2530fail_parent_names:
2531 kfree_const(core->name);
2532fail_name:
2533 kfree(core);
2534fail_out:
2535 return ERR_PTR(ret);
2536}
2537EXPORT_SYMBOL_GPL(clk_register);
2538
2539/* Free memory allocated for a clock. */
2540static void __clk_release(struct kref *ref)
2541{
2542 struct clk_core *core = container_of(ref, struct clk_core, ref);
2543 int i = core->num_parents;
2544
2545 lockdep_assert_held(&prepare_lock);
2546
2547 kfree(core->parents);
2548 while (--i >= 0)
2549 kfree_const(core->parent_names[i]);
2550
2551 kfree(core->parent_names);
2552 kfree_const(core->name);
2553 kfree(core);
2554}
2555
2556/*
2557 * Empty clk_ops for unregistered clocks. These are used temporarily
2558 * after clk_unregister() was called on a clock and until last clock
2559 * consumer calls clk_put() and the struct clk object is freed.
2560 */
2561static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2562{
2563 return -ENXIO;
2564}
2565
2566static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2567{
2568 WARN_ON_ONCE(1);
2569}
2570
2571static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2572 unsigned long parent_rate)
2573{
2574 return -ENXIO;
2575}
2576
2577static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2578{
2579 return -ENXIO;
2580}
2581
2582static const struct clk_ops clk_nodrv_ops = {
2583 .enable = clk_nodrv_prepare_enable,
2584 .disable = clk_nodrv_disable_unprepare,
2585 .prepare = clk_nodrv_prepare_enable,
2586 .unprepare = clk_nodrv_disable_unprepare,
2587 .set_rate = clk_nodrv_set_rate,
2588 .set_parent = clk_nodrv_set_parent,
2589};
2590
2591/**
2592 * clk_unregister - unregister a currently registered clock
2593 * @clk: clock to unregister
2594 */
2595void clk_unregister(struct clk *clk)
2596{
2597 unsigned long flags;
2598
2599 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2600 return;
2601
2602 clk_debug_unregister(clk->core);
2603
2604 clk_prepare_lock();
2605
2606 if (clk->core->ops == &clk_nodrv_ops) {
2607 pr_err("%s: unregistered clock: %s\n", __func__,
2608 clk->core->name);
2609 goto unlock;
2610 }
2611 /*
2612 * Assign empty clock ops for consumers that might still hold
2613 * a reference to this clock.
2614 */
2615 flags = clk_enable_lock();
2616 clk->core->ops = &clk_nodrv_ops;
2617 clk_enable_unlock(flags);
2618
2619 if (!hlist_empty(&clk->core->children)) {
2620 struct clk_core *child;
2621 struct hlist_node *t;
2622
2623 /* Reparent all children to the orphan list. */
2624 hlist_for_each_entry_safe(child, t, &clk->core->children,
2625 child_node)
2626 clk_core_set_parent(child, NULL);
2627 }
2628
2629 hlist_del_init(&clk->core->child_node);
2630
2631 if (clk->core->prepare_count)
2632 pr_warn("%s: unregistering prepared clock: %s\n",
2633 __func__, clk->core->name);
2634 kref_put(&clk->core->ref, __clk_release);
2635unlock:
2636 clk_prepare_unlock();
2637}
2638EXPORT_SYMBOL_GPL(clk_unregister);
2639
2640static void devm_clk_release(struct device *dev, void *res)
2641{
2642 clk_unregister(*(struct clk **)res);
2643}
2644
2645/**
2646 * devm_clk_register - resource managed clk_register()
2647 * @dev: device that is registering this clock
2648 * @hw: link to hardware-specific clock data
2649 *
2650 * Managed clk_register(). Clocks returned from this function are
2651 * automatically clk_unregister()ed on driver detach. See clk_register() for
2652 * more information.
2653 */
2654struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2655{
2656 struct clk *clk;
2657 struct clk **clkp;
2658
2659 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2660 if (!clkp)
2661 return ERR_PTR(-ENOMEM);
2662
2663 clk = clk_register(dev, hw);
2664 if (!IS_ERR(clk)) {
2665 *clkp = clk;
2666 devres_add(dev, clkp);
2667 } else {
2668 devres_free(clkp);
2669 }
2670
2671 return clk;
2672}
2673EXPORT_SYMBOL_GPL(devm_clk_register);
2674
2675static int devm_clk_match(struct device *dev, void *res, void *data)
2676{
2677 struct clk *c = res;
2678 if (WARN_ON(!c))
2679 return 0;
2680 return c == data;
2681}
2682
2683/**
2684 * devm_clk_unregister - resource managed clk_unregister()
2685 * @clk: clock to unregister
2686 *
2687 * Deallocate a clock allocated with devm_clk_register(). Normally
2688 * this function will not need to be called and the resource management
2689 * code will ensure that the resource is freed.
2690 */
2691void devm_clk_unregister(struct device *dev, struct clk *clk)
2692{
2693 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2694}
2695EXPORT_SYMBOL_GPL(devm_clk_unregister);
2696
2697/*
2698 * clkdev helpers
2699 */
2700int __clk_get(struct clk *clk)
2701{
2702 struct clk_core *core = !clk ? NULL : clk->core;
2703
2704 if (core) {
2705 if (!try_module_get(core->owner))
2706 return 0;
2707
2708 kref_get(&core->ref);
2709 }
2710 return 1;
2711}
2712
2713void __clk_put(struct clk *clk)
2714{
2715 struct module *owner;
2716
2717 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2718 return;
2719
2720 clk_prepare_lock();
2721
2722 hlist_del(&clk->clks_node);
2723 if (clk->min_rate > clk->core->req_rate ||
2724 clk->max_rate < clk->core->req_rate)
2725 clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
2726
2727 owner = clk->core->owner;
2728 kref_put(&clk->core->ref, __clk_release);
2729
2730 clk_prepare_unlock();
2731
2732 module_put(owner);
2733
2734 kfree(clk);
2735}
2736
2737/*** clk rate change notifiers ***/
2738
2739/**
2740 * clk_notifier_register - add a clk rate change notifier
2741 * @clk: struct clk * to watch
2742 * @nb: struct notifier_block * with callback info
2743 *
2744 * Request notification when clk's rate changes. This uses an SRCU
2745 * notifier because we want it to block and notifier unregistrations are
2746 * uncommon. The callbacks associated with the notifier must not
2747 * re-enter into the clk framework by calling any top-level clk APIs;
2748 * this will cause a nested prepare_lock mutex.
2749 *
2750 * In all notification cases (pre, post and abort rate change) the original
2751 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
2752 * and the new frequency is passed via struct clk_notifier_data.new_rate.
2753 *
2754 * clk_notifier_register() must be called from non-atomic context.
2755 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2756 * allocation failure; otherwise, passes along the return value of
2757 * srcu_notifier_chain_register().
2758 */
2759int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2760{
2761 struct clk_notifier *cn;
2762 int ret = -ENOMEM;
2763
2764 if (!clk || !nb)
2765 return -EINVAL;
2766
2767 clk_prepare_lock();
2768
2769 /* search the list of notifiers for this clk */
2770 list_for_each_entry(cn, &clk_notifier_list, node)
2771 if (cn->clk == clk)
2772 break;
2773
2774 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2775 if (cn->clk != clk) {
2776 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2777 if (!cn)
2778 goto out;
2779
2780 cn->clk = clk;
2781 srcu_init_notifier_head(&cn->notifier_head);
2782
2783 list_add(&cn->node, &clk_notifier_list);
2784 }
2785
2786 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2787
2788 clk->core->notifier_count++;
2789
2790out:
2791 clk_prepare_unlock();
2792
2793 return ret;
2794}
2795EXPORT_SYMBOL_GPL(clk_notifier_register);
2796
2797/**
2798 * clk_notifier_unregister - remove a clk rate change notifier
2799 * @clk: struct clk *
2800 * @nb: struct notifier_block * with callback info
2801 *
2802 * Request no further notification for changes to 'clk' and frees memory
2803 * allocated in clk_notifier_register.
2804 *
2805 * Returns -EINVAL if called with null arguments; otherwise, passes
2806 * along the return value of srcu_notifier_chain_unregister().
2807 */
2808int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2809{
2810 struct clk_notifier *cn = NULL;
2811 int ret = -EINVAL;
2812
2813 if (!clk || !nb)
2814 return -EINVAL;
2815
2816 clk_prepare_lock();
2817
2818 list_for_each_entry(cn, &clk_notifier_list, node)
2819 if (cn->clk == clk)
2820 break;
2821
2822 if (cn->clk == clk) {
2823 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2824
2825 clk->core->notifier_count--;
2826
2827 /* XXX the notifier code should handle this better */
2828 if (!cn->notifier_head.head) {
2829 srcu_cleanup_notifier_head(&cn->notifier_head);
2830 list_del(&cn->node);
2831 kfree(cn);
2832 }
2833
2834 } else {
2835 ret = -ENOENT;
2836 }
2837
2838 clk_prepare_unlock();
2839
2840 return ret;
2841}
2842EXPORT_SYMBOL_GPL(clk_notifier_unregister);
2843
2844#ifdef CONFIG_OF
2845/**
2846 * struct of_clk_provider - Clock provider registration structure
2847 * @link: Entry in global list of clock providers
2848 * @node: Pointer to device tree node of clock provider
2849 * @get: Get clock callback. Returns NULL or a struct clk for the
2850 * given clock specifier
2851 * @data: context pointer to be passed into @get callback
2852 */
2853struct of_clk_provider {
2854 struct list_head link;
2855
2856 struct device_node *node;
2857 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2858 void *data;
2859};
2860
2861static const struct of_device_id __clk_of_table_sentinel
2862 __used __section(__clk_of_table_end);
2863
2864static LIST_HEAD(of_clk_providers);
2865static DEFINE_MUTEX(of_clk_mutex);
2866
2867struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2868 void *data)
2869{
2870 return data;
2871}
2872EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2873
2874struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2875{
2876 struct clk_onecell_data *clk_data = data;
2877 unsigned int idx = clkspec->args[0];
2878
2879 if (idx >= clk_data->clk_num) {
2880 pr_err("%s: invalid clock index %u\n", __func__, idx);
2881 return ERR_PTR(-EINVAL);
2882 }
2883
2884 return clk_data->clks[idx];
2885}
2886EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2887
2888/**
2889 * of_clk_add_provider() - Register a clock provider for a node
2890 * @np: Device node pointer associated with clock provider
2891 * @clk_src_get: callback for decoding clock
2892 * @data: context pointer for @clk_src_get callback.
2893 */
2894int of_clk_add_provider(struct device_node *np,
2895 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2896 void *data),
2897 void *data)
2898{
2899 struct of_clk_provider *cp;
2900 int ret;
2901
2902 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2903 if (!cp)
2904 return -ENOMEM;
2905
2906 cp->node = of_node_get(np);
2907 cp->data = data;
2908 cp->get = clk_src_get;
2909
2910 mutex_lock(&of_clk_mutex);
2911 list_add(&cp->link, &of_clk_providers);
2912 mutex_unlock(&of_clk_mutex);
2913 pr_debug("Added clock from %s\n", np->full_name);
2914
2915 ret = of_clk_set_defaults(np, true);
2916 if (ret < 0)
2917 of_clk_del_provider(np);
2918
2919 return ret;
2920}
2921EXPORT_SYMBOL_GPL(of_clk_add_provider);
2922
2923/**
2924 * of_clk_del_provider() - Remove a previously registered clock provider
2925 * @np: Device node pointer associated with clock provider
2926 */
2927void of_clk_del_provider(struct device_node *np)
2928{
2929 struct of_clk_provider *cp;
2930
2931 mutex_lock(&of_clk_mutex);
2932 list_for_each_entry(cp, &of_clk_providers, link) {
2933 if (cp->node == np) {
2934 list_del(&cp->link);
2935 of_node_put(cp->node);
2936 kfree(cp);
2937 break;
2938 }
2939 }
2940 mutex_unlock(&of_clk_mutex);
2941}
2942EXPORT_SYMBOL_GPL(of_clk_del_provider);
2943
2944struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
2945 const char *dev_id, const char *con_id)
2946{
2947 struct of_clk_provider *provider;
2948 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
2949
2950 if (!clkspec)
2951 return ERR_PTR(-EINVAL);
2952
2953 /* Check if we have such a provider in our array */
2954 mutex_lock(&of_clk_mutex);
2955 list_for_each_entry(provider, &of_clk_providers, link) {
2956 if (provider->node == clkspec->np)
2957 clk = provider->get(clkspec, provider->data);
2958 if (!IS_ERR(clk)) {
2959 clk = __clk_create_clk(__clk_get_hw(clk), dev_id,
2960 con_id);
2961
2962 if (!IS_ERR(clk) && !__clk_get(clk)) {
2963 __clk_free_clk(clk);
2964 clk = ERR_PTR(-ENOENT);
2965 }
2966
2967 break;
2968 }
2969 }
2970 mutex_unlock(&of_clk_mutex);
2971
2972 return clk;
2973}
2974
2975/**
2976 * of_clk_get_from_provider() - Lookup a clock from a clock provider
2977 * @clkspec: pointer to a clock specifier data structure
2978 *
2979 * This function looks up a struct clk from the registered list of clock
2980 * providers, an input is a clock specifier data structure as returned
2981 * from the of_parse_phandle_with_args() function call.
2982 */
2983struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
2984{
2985 return __of_clk_get_from_provider(clkspec, NULL, __func__);
2986}
2987EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
2988
2989/**
2990 * of_clk_get_parent_count() - Count the number of clocks a device node has
2991 * @np: device node to count
2992 *
2993 * Returns: The number of clocks that are possible parents of this node
2994 */
2995unsigned int of_clk_get_parent_count(struct device_node *np)
2996{
2997 int count;
2998
2999 count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
3000 if (count < 0)
3001 return 0;
3002
3003 return count;
3004}
3005EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
3006
3007const char *of_clk_get_parent_name(struct device_node *np, int index)
3008{
3009 struct of_phandle_args clkspec;
3010 struct property *prop;
3011 const char *clk_name;
3012 const __be32 *vp;
3013 u32 pv;
3014 int rc;
3015 int count;
3016 struct clk *clk;
3017
3018 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
3019 &clkspec);
3020 if (rc)
3021 return NULL;
3022
3023 index = clkspec.args_count ? clkspec.args[0] : 0;
3024 count = 0;
3025
3026 /* if there is an indices property, use it to transfer the index
3027 * specified into an array offset for the clock-output-names property.
3028 */
3029 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
3030 if (index == pv) {
3031 index = count;
3032 break;
3033 }
3034 count++;
3035 }
3036 /* We went off the end of 'clock-indices' without finding it */
3037 if (prop && !vp)
3038 return NULL;
3039
3040 if (of_property_read_string_index(clkspec.np, "clock-output-names",
3041 index,
3042 &clk_name) < 0) {
3043 /*
3044 * Best effort to get the name if the clock has been
3045 * registered with the framework. If the clock isn't
3046 * registered, we return the node name as the name of
3047 * the clock as long as #clock-cells = 0.
3048 */
3049 clk = of_clk_get_from_provider(&clkspec);
3050 if (IS_ERR(clk)) {
3051 if (clkspec.args_count == 0)
3052 clk_name = clkspec.np->name;
3053 else
3054 clk_name = NULL;
3055 } else {
3056 clk_name = __clk_get_name(clk);
3057 clk_put(clk);
3058 }
3059 }
3060
3061
3062 of_node_put(clkspec.np);
3063 return clk_name;
3064}
3065EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
3066
3067/**
3068 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
3069 * number of parents
3070 * @np: Device node pointer associated with clock provider
3071 * @parents: pointer to char array that hold the parents' names
3072 * @size: size of the @parents array
3073 *
3074 * Return: number of parents for the clock node.
3075 */
3076int of_clk_parent_fill(struct device_node *np, const char **parents,
3077 unsigned int size)
3078{
3079 unsigned int i = 0;
3080
3081 while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
3082 i++;
3083
3084 return i;
3085}
3086EXPORT_SYMBOL_GPL(of_clk_parent_fill);
3087
3088struct clock_provider {
3089 of_clk_init_cb_t clk_init_cb;
3090 struct device_node *np;
3091 struct list_head node;
3092};
3093
3094/*
3095 * This function looks for a parent clock. If there is one, then it
3096 * checks that the provider for this parent clock was initialized, in
3097 * this case the parent clock will be ready.
3098 */
3099static int parent_ready(struct device_node *np)
3100{
3101 int i = 0;
3102
3103 while (true) {
3104 struct clk *clk = of_clk_get(np, i);
3105
3106 /* this parent is ready we can check the next one */
3107 if (!IS_ERR(clk)) {
3108 clk_put(clk);
3109 i++;
3110 continue;
3111 }
3112
3113 /* at least one parent is not ready, we exit now */
3114 if (PTR_ERR(clk) == -EPROBE_DEFER)
3115 return 0;
3116
3117 /*
3118 * Here we make assumption that the device tree is
3119 * written correctly. So an error means that there is
3120 * no more parent. As we didn't exit yet, then the
3121 * previous parent are ready. If there is no clock
3122 * parent, no need to wait for them, then we can
3123 * consider their absence as being ready
3124 */
3125 return 1;
3126 }
3127}
3128
3129/**
3130 * of_clk_init() - Scan and init clock providers from the DT
3131 * @matches: array of compatible values and init functions for providers.
3132 *
3133 * This function scans the device tree for matching clock providers
3134 * and calls their initialization functions. It also does it by trying
3135 * to follow the dependencies.
3136 */
3137void __init of_clk_init(const struct of_device_id *matches)
3138{
3139 const struct of_device_id *match;
3140 struct device_node *np;
3141 struct clock_provider *clk_provider, *next;
3142 bool is_init_done;
3143 bool force = false;
3144 LIST_HEAD(clk_provider_list);
3145
3146 if (!matches)
3147 matches = &__clk_of_table;
3148
3149 /* First prepare the list of the clocks providers */
3150 for_each_matching_node_and_match(np, matches, &match) {
3151 struct clock_provider *parent;
3152
3153 if (!of_device_is_available(np))
3154 continue;
3155
3156 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
3157 if (!parent) {
3158 list_for_each_entry_safe(clk_provider, next,
3159 &clk_provider_list, node) {
3160 list_del(&clk_provider->node);
3161 of_node_put(clk_provider->np);
3162 kfree(clk_provider);
3163 }
3164 of_node_put(np);
3165 return;
3166 }
3167
3168 parent->clk_init_cb = match->data;
3169 parent->np = of_node_get(np);
3170 list_add_tail(&parent->node, &clk_provider_list);
3171 }
3172
3173 while (!list_empty(&clk_provider_list)) {
3174 is_init_done = false;
3175 list_for_each_entry_safe(clk_provider, next,
3176 &clk_provider_list, node) {
3177 if (force || parent_ready(clk_provider->np)) {
3178
3179 clk_provider->clk_init_cb(clk_provider->np);
3180 of_clk_set_defaults(clk_provider->np, true);
3181
3182 list_del(&clk_provider->node);
3183 of_node_put(clk_provider->np);
3184 kfree(clk_provider);
3185 is_init_done = true;
3186 }
3187 }
3188
3189 /*
3190 * We didn't manage to initialize any of the
3191 * remaining providers during the last loop, so now we
3192 * initialize all the remaining ones unconditionally
3193 * in case the clock parent was not mandatory
3194 */
3195 if (!is_init_done)
3196 force = true;
3197 }
3198}
3199#endif