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