clk: Don't check for missing ops in clk_set_parent()
[deliverable/linux.git] / drivers / clk / clk.c
CommitLineData
b2476490
MT
1/*
2 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
3 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Standard functionality for the common clock API. See Documentation/clk.txt
10 */
11
12#include <linux/clk-private.h>
13#include <linux/module.h>
14#include <linux/mutex.h>
15#include <linux/spinlock.h>
16#include <linux/err.h>
17#include <linux/list.h>
18#include <linux/slab.h>
766e6a4e 19#include <linux/of.h>
46c8773a 20#include <linux/device.h>
f2f6c255 21#include <linux/init.h>
533ddeb1 22#include <linux/sched.h>
b2476490 23
d6782c26
SN
24#include "clk.h"
25
b2476490
MT
26static DEFINE_SPINLOCK(enable_lock);
27static DEFINE_MUTEX(prepare_lock);
28
533ddeb1
MT
29static struct task_struct *prepare_owner;
30static struct task_struct *enable_owner;
31
32static int prepare_refcnt;
33static int enable_refcnt;
34
b2476490
MT
35static HLIST_HEAD(clk_root_list);
36static HLIST_HEAD(clk_orphan_list);
37static LIST_HEAD(clk_notifier_list);
38
eab89f69
MT
39/*** locking ***/
40static void clk_prepare_lock(void)
41{
533ddeb1
MT
42 if (!mutex_trylock(&prepare_lock)) {
43 if (prepare_owner == current) {
44 prepare_refcnt++;
45 return;
46 }
47 mutex_lock(&prepare_lock);
48 }
49 WARN_ON_ONCE(prepare_owner != NULL);
50 WARN_ON_ONCE(prepare_refcnt != 0);
51 prepare_owner = current;
52 prepare_refcnt = 1;
eab89f69
MT
53}
54
55static void clk_prepare_unlock(void)
56{
533ddeb1
MT
57 WARN_ON_ONCE(prepare_owner != current);
58 WARN_ON_ONCE(prepare_refcnt == 0);
59
60 if (--prepare_refcnt)
61 return;
62 prepare_owner = NULL;
eab89f69
MT
63 mutex_unlock(&prepare_lock);
64}
65
66static unsigned long clk_enable_lock(void)
67{
68 unsigned long flags;
533ddeb1
MT
69
70 if (!spin_trylock_irqsave(&enable_lock, flags)) {
71 if (enable_owner == current) {
72 enable_refcnt++;
73 return flags;
74 }
75 spin_lock_irqsave(&enable_lock, flags);
76 }
77 WARN_ON_ONCE(enable_owner != NULL);
78 WARN_ON_ONCE(enable_refcnt != 0);
79 enable_owner = current;
80 enable_refcnt = 1;
eab89f69
MT
81 return flags;
82}
83
84static void clk_enable_unlock(unsigned long flags)
85{
533ddeb1
MT
86 WARN_ON_ONCE(enable_owner != current);
87 WARN_ON_ONCE(enable_refcnt == 0);
88
89 if (--enable_refcnt)
90 return;
91 enable_owner = NULL;
eab89f69
MT
92 spin_unlock_irqrestore(&enable_lock, flags);
93}
94
b2476490
MT
95/*** debugfs support ***/
96
ea72dc2c 97#ifdef CONFIG_DEBUG_FS
b2476490
MT
98#include <linux/debugfs.h>
99
100static struct dentry *rootdir;
101static struct dentry *orphandir;
102static int inited = 0;
103
1af599df
PG
104static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level)
105{
106 if (!c)
107 return;
108
5279fc40 109 seq_printf(s, "%*s%-*s %-11d %-12d %-10lu %-11lu",
1af599df
PG
110 level * 3 + 1, "",
111 30 - level * 3, c->name,
5279fc40
BB
112 c->enable_count, c->prepare_count, clk_get_rate(c),
113 clk_get_accuracy(c));
1af599df
PG
114 seq_printf(s, "\n");
115}
116
117static void clk_summary_show_subtree(struct seq_file *s, struct clk *c,
118 int level)
119{
120 struct clk *child;
1af599df
PG
121
122 if (!c)
123 return;
124
125 clk_summary_show_one(s, c, level);
126
b67bfe0d 127 hlist_for_each_entry(child, &c->children, child_node)
1af599df
PG
128 clk_summary_show_subtree(s, child, level + 1);
129}
130
131static int clk_summary_show(struct seq_file *s, void *data)
132{
133 struct clk *c;
1af599df 134
5279fc40
BB
135 seq_printf(s, " clock enable_cnt prepare_cnt rate accuracy\n");
136 seq_printf(s, "---------------------------------------------------------------------------------\n");
1af599df 137
eab89f69 138 clk_prepare_lock();
1af599df 139
b67bfe0d 140 hlist_for_each_entry(c, &clk_root_list, child_node)
1af599df
PG
141 clk_summary_show_subtree(s, c, 0);
142
b67bfe0d 143 hlist_for_each_entry(c, &clk_orphan_list, child_node)
1af599df
PG
144 clk_summary_show_subtree(s, c, 0);
145
eab89f69 146 clk_prepare_unlock();
1af599df
PG
147
148 return 0;
149}
150
151
152static int clk_summary_open(struct inode *inode, struct file *file)
153{
154 return single_open(file, clk_summary_show, inode->i_private);
155}
156
157static const struct file_operations clk_summary_fops = {
158 .open = clk_summary_open,
159 .read = seq_read,
160 .llseek = seq_lseek,
161 .release = single_release,
162};
163
bddca894
PG
164static void clk_dump_one(struct seq_file *s, struct clk *c, int level)
165{
166 if (!c)
167 return;
168
169 seq_printf(s, "\"%s\": { ", c->name);
170 seq_printf(s, "\"enable_count\": %d,", c->enable_count);
171 seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
670decdd 172 seq_printf(s, "\"rate\": %lu", clk_get_rate(c));
5279fc40 173 seq_printf(s, "\"accuracy\": %lu", clk_get_accuracy(c));
bddca894
PG
174}
175
176static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level)
177{
178 struct clk *child;
bddca894
PG
179
180 if (!c)
181 return;
182
183 clk_dump_one(s, c, level);
184
b67bfe0d 185 hlist_for_each_entry(child, &c->children, child_node) {
bddca894
PG
186 seq_printf(s, ",");
187 clk_dump_subtree(s, child, level + 1);
188 }
189
190 seq_printf(s, "}");
191}
192
193static int clk_dump(struct seq_file *s, void *data)
194{
195 struct clk *c;
bddca894
PG
196 bool first_node = true;
197
198 seq_printf(s, "{");
199
eab89f69 200 clk_prepare_lock();
bddca894 201
b67bfe0d 202 hlist_for_each_entry(c, &clk_root_list, child_node) {
bddca894
PG
203 if (!first_node)
204 seq_printf(s, ",");
205 first_node = false;
206 clk_dump_subtree(s, c, 0);
207 }
208
b67bfe0d 209 hlist_for_each_entry(c, &clk_orphan_list, child_node) {
bddca894
PG
210 seq_printf(s, ",");
211 clk_dump_subtree(s, c, 0);
212 }
213
eab89f69 214 clk_prepare_unlock();
bddca894
PG
215
216 seq_printf(s, "}");
217 return 0;
218}
219
220
221static int clk_dump_open(struct inode *inode, struct file *file)
222{
223 return single_open(file, clk_dump, inode->i_private);
224}
225
226static const struct file_operations clk_dump_fops = {
227 .open = clk_dump_open,
228 .read = seq_read,
229 .llseek = seq_lseek,
230 .release = single_release,
231};
232
b2476490
MT
233/* caller must hold prepare_lock */
234static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry)
235{
236 struct dentry *d;
237 int ret = -ENOMEM;
238
239 if (!clk || !pdentry) {
240 ret = -EINVAL;
241 goto out;
242 }
243
244 d = debugfs_create_dir(clk->name, pdentry);
245 if (!d)
246 goto out;
247
248 clk->dentry = d;
249
250 d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry,
251 (u32 *)&clk->rate);
252 if (!d)
253 goto err_out;
254
5279fc40
BB
255 d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry,
256 (u32 *)&clk->accuracy);
257 if (!d)
258 goto err_out;
259
b2476490
MT
260 d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry,
261 (u32 *)&clk->flags);
262 if (!d)
263 goto err_out;
264
265 d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry,
266 (u32 *)&clk->prepare_count);
267 if (!d)
268 goto err_out;
269
270 d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry,
271 (u32 *)&clk->enable_count);
272 if (!d)
273 goto err_out;
274
275 d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry,
276 (u32 *)&clk->notifier_count);
277 if (!d)
278 goto err_out;
279
c646cbf1
AE
280 if (clk->ops->debug_init)
281 if (clk->ops->debug_init(clk->hw, clk->dentry))
282 goto err_out;
283
b2476490
MT
284 ret = 0;
285 goto out;
286
287err_out:
b5f98e65
AE
288 debugfs_remove_recursive(clk->dentry);
289 clk->dentry = NULL;
b2476490
MT
290out:
291 return ret;
292}
293
294/* caller must hold prepare_lock */
295static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry)
296{
297 struct clk *child;
b2476490
MT
298 int ret = -EINVAL;;
299
300 if (!clk || !pdentry)
301 goto out;
302
303 ret = clk_debug_create_one(clk, pdentry);
304
305 if (ret)
306 goto out;
307
b67bfe0d 308 hlist_for_each_entry(child, &clk->children, child_node)
b2476490
MT
309 clk_debug_create_subtree(child, clk->dentry);
310
311 ret = 0;
312out:
313 return ret;
314}
315
316/**
317 * clk_debug_register - add a clk node to the debugfs clk tree
318 * @clk: the clk being added to the debugfs clk tree
319 *
320 * Dynamically adds a clk to the debugfs clk tree if debugfs has been
321 * initialized. Otherwise it bails out early since the debugfs clk tree
322 * will be created lazily by clk_debug_init as part of a late_initcall.
323 *
324 * Caller must hold prepare_lock. Only clk_init calls this function (so
325 * far) so this is taken care.
326 */
327static int clk_debug_register(struct clk *clk)
328{
329 struct clk *parent;
330 struct dentry *pdentry;
331 int ret = 0;
332
333 if (!inited)
334 goto out;
335
336 parent = clk->parent;
337
338 /*
339 * Check to see if a clk is a root clk. Also check that it is
340 * safe to add this clk to debugfs
341 */
342 if (!parent)
343 if (clk->flags & CLK_IS_ROOT)
344 pdentry = rootdir;
345 else
346 pdentry = orphandir;
347 else
348 if (parent->dentry)
349 pdentry = parent->dentry;
350 else
351 goto out;
352
353 ret = clk_debug_create_subtree(clk, pdentry);
354
355out:
356 return ret;
357}
358
fcb0ee6a
SN
359 /**
360 * clk_debug_unregister - remove a clk node from the debugfs clk tree
361 * @clk: the clk being removed from the debugfs clk tree
362 *
363 * Dynamically removes a clk and all it's children clk nodes from the
364 * debugfs clk tree if clk->dentry points to debugfs created by
365 * clk_debug_register in __clk_init.
366 *
367 * Caller must hold prepare_lock.
368 */
369static void clk_debug_unregister(struct clk *clk)
370{
371 debugfs_remove_recursive(clk->dentry);
372}
373
b33d212f
UH
374/**
375 * clk_debug_reparent - reparent clk node in the debugfs clk tree
376 * @clk: the clk being reparented
377 * @new_parent: the new clk parent, may be NULL
378 *
379 * Rename clk entry in the debugfs clk tree if debugfs has been
380 * initialized. Otherwise it bails out early since the debugfs clk tree
381 * will be created lazily by clk_debug_init as part of a late_initcall.
382 *
383 * Caller must hold prepare_lock.
384 */
385static void clk_debug_reparent(struct clk *clk, struct clk *new_parent)
386{
387 struct dentry *d;
388 struct dentry *new_parent_d;
389
390 if (!inited)
391 return;
392
393 if (new_parent)
394 new_parent_d = new_parent->dentry;
395 else
396 new_parent_d = orphandir;
397
398 d = debugfs_rename(clk->dentry->d_parent, clk->dentry,
399 new_parent_d, clk->name);
400 if (d)
401 clk->dentry = d;
402 else
403 pr_debug("%s: failed to rename debugfs entry for %s\n",
404 __func__, clk->name);
405}
406
b2476490
MT
407/**
408 * clk_debug_init - lazily create the debugfs clk tree visualization
409 *
410 * clks are often initialized very early during boot before memory can
411 * be dynamically allocated and well before debugfs is setup.
412 * clk_debug_init walks the clk tree hierarchy while holding
413 * prepare_lock and creates the topology as part of a late_initcall,
414 * thus insuring that clks initialized very early will still be
415 * represented in the debugfs clk tree. This function should only be
416 * called once at boot-time, and all other clks added dynamically will
417 * be done so with clk_debug_register.
418 */
419static int __init clk_debug_init(void)
420{
421 struct clk *clk;
1af599df 422 struct dentry *d;
b2476490
MT
423
424 rootdir = debugfs_create_dir("clk", NULL);
425
426 if (!rootdir)
427 return -ENOMEM;
428
1af599df
PG
429 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, NULL,
430 &clk_summary_fops);
431 if (!d)
432 return -ENOMEM;
433
bddca894
PG
434 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, NULL,
435 &clk_dump_fops);
436 if (!d)
437 return -ENOMEM;
438
b2476490
MT
439 orphandir = debugfs_create_dir("orphans", rootdir);
440
441 if (!orphandir)
442 return -ENOMEM;
443
eab89f69 444 clk_prepare_lock();
b2476490 445
b67bfe0d 446 hlist_for_each_entry(clk, &clk_root_list, child_node)
b2476490
MT
447 clk_debug_create_subtree(clk, rootdir);
448
b67bfe0d 449 hlist_for_each_entry(clk, &clk_orphan_list, child_node)
b2476490
MT
450 clk_debug_create_subtree(clk, orphandir);
451
452 inited = 1;
453
eab89f69 454 clk_prepare_unlock();
b2476490
MT
455
456 return 0;
457}
458late_initcall(clk_debug_init);
459#else
460static inline int clk_debug_register(struct clk *clk) { return 0; }
b33d212f
UH
461static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent)
462{
463}
fcb0ee6a
SN
464static inline void clk_debug_unregister(struct clk *clk)
465{
466}
70d347e6 467#endif
b2476490 468
1c155b3d
UH
469/* caller must hold prepare_lock */
470static void clk_unprepare_unused_subtree(struct clk *clk)
471{
472 struct clk *child;
473
474 if (!clk)
475 return;
476
477 hlist_for_each_entry(child, &clk->children, child_node)
478 clk_unprepare_unused_subtree(child);
479
480 if (clk->prepare_count)
481 return;
482
483 if (clk->flags & CLK_IGNORE_UNUSED)
484 return;
485
3cc8247f
UH
486 if (__clk_is_prepared(clk)) {
487 if (clk->ops->unprepare_unused)
488 clk->ops->unprepare_unused(clk->hw);
489 else if (clk->ops->unprepare)
1c155b3d 490 clk->ops->unprepare(clk->hw);
3cc8247f 491 }
1c155b3d
UH
492}
493
b2476490
MT
494/* caller must hold prepare_lock */
495static void clk_disable_unused_subtree(struct clk *clk)
496{
497 struct clk *child;
b2476490
MT
498 unsigned long flags;
499
500 if (!clk)
501 goto out;
502
b67bfe0d 503 hlist_for_each_entry(child, &clk->children, child_node)
b2476490
MT
504 clk_disable_unused_subtree(child);
505
eab89f69 506 flags = clk_enable_lock();
b2476490
MT
507
508 if (clk->enable_count)
509 goto unlock_out;
510
511 if (clk->flags & CLK_IGNORE_UNUSED)
512 goto unlock_out;
513
7c045a55
MT
514 /*
515 * some gate clocks have special needs during the disable-unused
516 * sequence. call .disable_unused if available, otherwise fall
517 * back to .disable
518 */
519 if (__clk_is_enabled(clk)) {
520 if (clk->ops->disable_unused)
521 clk->ops->disable_unused(clk->hw);
522 else if (clk->ops->disable)
523 clk->ops->disable(clk->hw);
524 }
b2476490
MT
525
526unlock_out:
eab89f69 527 clk_enable_unlock(flags);
b2476490
MT
528
529out:
530 return;
531}
532
1e435256
OJ
533static bool clk_ignore_unused;
534static int __init clk_ignore_unused_setup(char *__unused)
535{
536 clk_ignore_unused = true;
537 return 1;
538}
539__setup("clk_ignore_unused", clk_ignore_unused_setup);
540
b2476490
MT
541static int clk_disable_unused(void)
542{
543 struct clk *clk;
b2476490 544
1e435256
OJ
545 if (clk_ignore_unused) {
546 pr_warn("clk: Not disabling unused clocks\n");
547 return 0;
548 }
549
eab89f69 550 clk_prepare_lock();
b2476490 551
b67bfe0d 552 hlist_for_each_entry(clk, &clk_root_list, child_node)
b2476490
MT
553 clk_disable_unused_subtree(clk);
554
b67bfe0d 555 hlist_for_each_entry(clk, &clk_orphan_list, child_node)
b2476490
MT
556 clk_disable_unused_subtree(clk);
557
1c155b3d
UH
558 hlist_for_each_entry(clk, &clk_root_list, child_node)
559 clk_unprepare_unused_subtree(clk);
560
561 hlist_for_each_entry(clk, &clk_orphan_list, child_node)
562 clk_unprepare_unused_subtree(clk);
563
eab89f69 564 clk_prepare_unlock();
b2476490
MT
565
566 return 0;
567}
d41d5805 568late_initcall_sync(clk_disable_unused);
b2476490
MT
569
570/*** helper functions ***/
571
65800b2c 572const char *__clk_get_name(struct clk *clk)
b2476490
MT
573{
574 return !clk ? NULL : clk->name;
575}
4895084c 576EXPORT_SYMBOL_GPL(__clk_get_name);
b2476490 577
65800b2c 578struct clk_hw *__clk_get_hw(struct clk *clk)
b2476490
MT
579{
580 return !clk ? NULL : clk->hw;
581}
0b7f04b8 582EXPORT_SYMBOL_GPL(__clk_get_hw);
b2476490 583
65800b2c 584u8 __clk_get_num_parents(struct clk *clk)
b2476490 585{
2ac6b1f5 586 return !clk ? 0 : clk->num_parents;
b2476490 587}
0b7f04b8 588EXPORT_SYMBOL_GPL(__clk_get_num_parents);
b2476490 589
65800b2c 590struct clk *__clk_get_parent(struct clk *clk)
b2476490
MT
591{
592 return !clk ? NULL : clk->parent;
593}
0b7f04b8 594EXPORT_SYMBOL_GPL(__clk_get_parent);
b2476490 595
7ef3dcc8
JH
596struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
597{
598 if (!clk || index >= clk->num_parents)
599 return NULL;
600 else if (!clk->parents)
601 return __clk_lookup(clk->parent_names[index]);
602 else if (!clk->parents[index])
603 return clk->parents[index] =
604 __clk_lookup(clk->parent_names[index]);
605 else
606 return clk->parents[index];
607}
0b7f04b8 608EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
7ef3dcc8 609
65800b2c 610unsigned int __clk_get_enable_count(struct clk *clk)
b2476490 611{
2ac6b1f5 612 return !clk ? 0 : clk->enable_count;
b2476490
MT
613}
614
65800b2c 615unsigned int __clk_get_prepare_count(struct clk *clk)
b2476490 616{
2ac6b1f5 617 return !clk ? 0 : clk->prepare_count;
b2476490
MT
618}
619
620unsigned long __clk_get_rate(struct clk *clk)
621{
622 unsigned long ret;
623
624 if (!clk) {
34e44fe8 625 ret = 0;
b2476490
MT
626 goto out;
627 }
628
629 ret = clk->rate;
630
631 if (clk->flags & CLK_IS_ROOT)
632 goto out;
633
634 if (!clk->parent)
34e44fe8 635 ret = 0;
b2476490
MT
636
637out:
638 return ret;
639}
0b7f04b8 640EXPORT_SYMBOL_GPL(__clk_get_rate);
b2476490 641
5279fc40
BB
642unsigned long __clk_get_accuracy(struct clk *clk)
643{
644 if (!clk)
645 return 0;
646
647 return clk->accuracy;
648}
649
65800b2c 650unsigned long __clk_get_flags(struct clk *clk)
b2476490 651{
2ac6b1f5 652 return !clk ? 0 : clk->flags;
b2476490 653}
b05c6836 654EXPORT_SYMBOL_GPL(__clk_get_flags);
b2476490 655
3d6ee287
UH
656bool __clk_is_prepared(struct clk *clk)
657{
658 int ret;
659
660 if (!clk)
661 return false;
662
663 /*
664 * .is_prepared is optional for clocks that can prepare
665 * fall back to software usage counter if it is missing
666 */
667 if (!clk->ops->is_prepared) {
668 ret = clk->prepare_count ? 1 : 0;
669 goto out;
670 }
671
672 ret = clk->ops->is_prepared(clk->hw);
673out:
674 return !!ret;
675}
676
2ac6b1f5 677bool __clk_is_enabled(struct clk *clk)
b2476490
MT
678{
679 int ret;
680
681 if (!clk)
2ac6b1f5 682 return false;
b2476490
MT
683
684 /*
685 * .is_enabled is only mandatory for clocks that gate
686 * fall back to software usage counter if .is_enabled is missing
687 */
688 if (!clk->ops->is_enabled) {
689 ret = clk->enable_count ? 1 : 0;
690 goto out;
691 }
692
693 ret = clk->ops->is_enabled(clk->hw);
694out:
2ac6b1f5 695 return !!ret;
b2476490 696}
0b7f04b8 697EXPORT_SYMBOL_GPL(__clk_is_enabled);
b2476490
MT
698
699static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk)
700{
701 struct clk *child;
702 struct clk *ret;
b2476490
MT
703
704 if (!strcmp(clk->name, name))
705 return clk;
706
b67bfe0d 707 hlist_for_each_entry(child, &clk->children, child_node) {
b2476490
MT
708 ret = __clk_lookup_subtree(name, child);
709 if (ret)
710 return ret;
711 }
712
713 return NULL;
714}
715
716struct clk *__clk_lookup(const char *name)
717{
718 struct clk *root_clk;
719 struct clk *ret;
b2476490
MT
720
721 if (!name)
722 return NULL;
723
724 /* search the 'proper' clk tree first */
b67bfe0d 725 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
b2476490
MT
726 ret = __clk_lookup_subtree(name, root_clk);
727 if (ret)
728 return ret;
729 }
730
731 /* if not found, then search the orphan tree */
b67bfe0d 732 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
b2476490
MT
733 ret = __clk_lookup_subtree(name, root_clk);
734 if (ret)
735 return ret;
736 }
737
738 return NULL;
739}
740
e366fdd7
JH
741/*
742 * Helper for finding best parent to provide a given frequency. This can be used
743 * directly as a determine_rate callback (e.g. for a mux), or from a more
744 * complex clock that may combine a mux with other operations.
745 */
746long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
747 unsigned long *best_parent_rate,
748 struct clk **best_parent_p)
749{
750 struct clk *clk = hw->clk, *parent, *best_parent = NULL;
751 int i, num_parents;
752 unsigned long parent_rate, best = 0;
753
754 /* if NO_REPARENT flag set, pass through to current parent */
755 if (clk->flags & CLK_SET_RATE_NO_REPARENT) {
756 parent = clk->parent;
757 if (clk->flags & CLK_SET_RATE_PARENT)
758 best = __clk_round_rate(parent, rate);
759 else if (parent)
760 best = __clk_get_rate(parent);
761 else
762 best = __clk_get_rate(clk);
763 goto out;
764 }
765
766 /* find the parent that can provide the fastest rate <= rate */
767 num_parents = clk->num_parents;
768 for (i = 0; i < num_parents; i++) {
769 parent = clk_get_parent_by_index(clk, i);
770 if (!parent)
771 continue;
772 if (clk->flags & CLK_SET_RATE_PARENT)
773 parent_rate = __clk_round_rate(parent, rate);
774 else
775 parent_rate = __clk_get_rate(parent);
776 if (parent_rate <= rate && parent_rate > best) {
777 best_parent = parent;
778 best = parent_rate;
779 }
780 }
781
782out:
783 if (best_parent)
784 *best_parent_p = best_parent;
785 *best_parent_rate = best;
786
787 return best;
788}
0b7f04b8 789EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
e366fdd7 790
b2476490
MT
791/*** clk api ***/
792
793void __clk_unprepare(struct clk *clk)
794{
795 if (!clk)
796 return;
797
798 if (WARN_ON(clk->prepare_count == 0))
799 return;
800
801 if (--clk->prepare_count > 0)
802 return;
803
804 WARN_ON(clk->enable_count > 0);
805
806 if (clk->ops->unprepare)
807 clk->ops->unprepare(clk->hw);
808
809 __clk_unprepare(clk->parent);
810}
811
812/**
813 * clk_unprepare - undo preparation of a clock source
24ee1a08 814 * @clk: the clk being unprepared
b2476490
MT
815 *
816 * clk_unprepare may sleep, which differentiates it from clk_disable. In a
817 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
818 * if the operation may sleep. One example is a clk which is accessed over
819 * I2c. In the complex case a clk gate operation may require a fast and a slow
820 * part. It is this reason that clk_unprepare and clk_disable are not mutually
821 * exclusive. In fact clk_disable must be called before clk_unprepare.
822 */
823void clk_unprepare(struct clk *clk)
824{
eab89f69 825 clk_prepare_lock();
b2476490 826 __clk_unprepare(clk);
eab89f69 827 clk_prepare_unlock();
b2476490
MT
828}
829EXPORT_SYMBOL_GPL(clk_unprepare);
830
831int __clk_prepare(struct clk *clk)
832{
833 int ret = 0;
834
835 if (!clk)
836 return 0;
837
838 if (clk->prepare_count == 0) {
839 ret = __clk_prepare(clk->parent);
840 if (ret)
841 return ret;
842
843 if (clk->ops->prepare) {
844 ret = clk->ops->prepare(clk->hw);
845 if (ret) {
846 __clk_unprepare(clk->parent);
847 return ret;
848 }
849 }
850 }
851
852 clk->prepare_count++;
853
854 return 0;
855}
856
857/**
858 * clk_prepare - prepare a clock source
859 * @clk: the clk being prepared
860 *
861 * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
862 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
863 * operation may sleep. One example is a clk which is accessed over I2c. In
864 * the complex case a clk ungate operation may require a fast and a slow part.
865 * It is this reason that clk_prepare and clk_enable are not mutually
866 * exclusive. In fact clk_prepare must be called before clk_enable.
867 * Returns 0 on success, -EERROR otherwise.
868 */
869int clk_prepare(struct clk *clk)
870{
871 int ret;
872
eab89f69 873 clk_prepare_lock();
b2476490 874 ret = __clk_prepare(clk);
eab89f69 875 clk_prepare_unlock();
b2476490
MT
876
877 return ret;
878}
879EXPORT_SYMBOL_GPL(clk_prepare);
880
881static void __clk_disable(struct clk *clk)
882{
883 if (!clk)
884 return;
885
e47c6a34
FW
886 if (WARN_ON(IS_ERR(clk)))
887 return;
888
b2476490
MT
889 if (WARN_ON(clk->enable_count == 0))
890 return;
891
892 if (--clk->enable_count > 0)
893 return;
894
895 if (clk->ops->disable)
896 clk->ops->disable(clk->hw);
897
898 __clk_disable(clk->parent);
899}
900
901/**
902 * clk_disable - gate a clock
903 * @clk: the clk being gated
904 *
905 * clk_disable must not sleep, which differentiates it from clk_unprepare. In
906 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
907 * clk if the operation is fast and will never sleep. One example is a
908 * SoC-internal clk which is controlled via simple register writes. In the
909 * complex case a clk gate operation may require a fast and a slow part. It is
910 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
911 * In fact clk_disable must be called before clk_unprepare.
912 */
913void clk_disable(struct clk *clk)
914{
915 unsigned long flags;
916
eab89f69 917 flags = clk_enable_lock();
b2476490 918 __clk_disable(clk);
eab89f69 919 clk_enable_unlock(flags);
b2476490
MT
920}
921EXPORT_SYMBOL_GPL(clk_disable);
922
923static int __clk_enable(struct clk *clk)
924{
925 int ret = 0;
926
927 if (!clk)
928 return 0;
929
930 if (WARN_ON(clk->prepare_count == 0))
931 return -ESHUTDOWN;
932
933 if (clk->enable_count == 0) {
934 ret = __clk_enable(clk->parent);
935
936 if (ret)
937 return ret;
938
939 if (clk->ops->enable) {
940 ret = clk->ops->enable(clk->hw);
941 if (ret) {
942 __clk_disable(clk->parent);
943 return ret;
944 }
945 }
946 }
947
948 clk->enable_count++;
949 return 0;
950}
951
952/**
953 * clk_enable - ungate a clock
954 * @clk: the clk being ungated
955 *
956 * clk_enable must not sleep, which differentiates it from clk_prepare. In a
957 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
958 * if the operation will never sleep. One example is a SoC-internal clk which
959 * is controlled via simple register writes. In the complex case a clk ungate
960 * operation may require a fast and a slow part. It is this reason that
961 * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
962 * must be called before clk_enable. Returns 0 on success, -EERROR
963 * otherwise.
964 */
965int clk_enable(struct clk *clk)
966{
967 unsigned long flags;
968 int ret;
969
eab89f69 970 flags = clk_enable_lock();
b2476490 971 ret = __clk_enable(clk);
eab89f69 972 clk_enable_unlock(flags);
b2476490
MT
973
974 return ret;
975}
976EXPORT_SYMBOL_GPL(clk_enable);
977
b2476490
MT
978/**
979 * __clk_round_rate - round the given rate for a clk
980 * @clk: round the rate of this clock
24ee1a08 981 * @rate: the rate which is to be rounded
b2476490
MT
982 *
983 * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate
984 */
985unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
986{
81536e07 987 unsigned long parent_rate = 0;
71472c0c 988 struct clk *parent;
b2476490
MT
989
990 if (!clk)
2ac6b1f5 991 return 0;
b2476490 992
71472c0c
JH
993 parent = clk->parent;
994 if (parent)
995 parent_rate = parent->rate;
996
997 if (clk->ops->determine_rate)
998 return clk->ops->determine_rate(clk->hw, rate, &parent_rate,
999 &parent);
1000 else if (clk->ops->round_rate)
1001 return clk->ops->round_rate(clk->hw, rate, &parent_rate);
1002 else if (clk->flags & CLK_SET_RATE_PARENT)
1003 return __clk_round_rate(clk->parent, rate);
1004 else
1005 return clk->rate;
b2476490
MT
1006}
1007
1008/**
1009 * clk_round_rate - round the given rate for a clk
1010 * @clk: the clk for which we are rounding a rate
1011 * @rate: the rate which is to be rounded
1012 *
1013 * Takes in a rate as input and rounds it to a rate that the clk can actually
1014 * use which is then returned. If clk doesn't support round_rate operation
1015 * then the parent rate is returned.
1016 */
1017long clk_round_rate(struct clk *clk, unsigned long rate)
1018{
1019 unsigned long ret;
1020
eab89f69 1021 clk_prepare_lock();
b2476490 1022 ret = __clk_round_rate(clk, rate);
eab89f69 1023 clk_prepare_unlock();
b2476490
MT
1024
1025 return ret;
1026}
1027EXPORT_SYMBOL_GPL(clk_round_rate);
1028
1029/**
1030 * __clk_notify - call clk notifier chain
1031 * @clk: struct clk * that is changing rate
1032 * @msg: clk notifier type (see include/linux/clk.h)
1033 * @old_rate: old clk rate
1034 * @new_rate: new clk rate
1035 *
1036 * Triggers a notifier call chain on the clk rate-change notification
1037 * for 'clk'. Passes a pointer to the struct clk and the previous
1038 * and current rates to the notifier callback. Intended to be called by
1039 * internal clock code only. Returns NOTIFY_DONE from the last driver
1040 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1041 * a driver returns that.
1042 */
1043static int __clk_notify(struct clk *clk, unsigned long msg,
1044 unsigned long old_rate, unsigned long new_rate)
1045{
1046 struct clk_notifier *cn;
1047 struct clk_notifier_data cnd;
1048 int ret = NOTIFY_DONE;
1049
1050 cnd.clk = clk;
1051 cnd.old_rate = old_rate;
1052 cnd.new_rate = new_rate;
1053
1054 list_for_each_entry(cn, &clk_notifier_list, node) {
1055 if (cn->clk == clk) {
1056 ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1057 &cnd);
1058 break;
1059 }
1060 }
1061
1062 return ret;
1063}
1064
5279fc40
BB
1065/**
1066 * __clk_recalc_accuracies
1067 * @clk: first clk in the subtree
1068 *
1069 * Walks the subtree of clks starting with clk and recalculates accuracies as
1070 * it goes. Note that if a clk does not implement the .recalc_accuracy
1071 * callback then it is assumed that the clock will take on the accuracy of it's
1072 * parent.
1073 *
1074 * Caller must hold prepare_lock.
1075 */
1076static void __clk_recalc_accuracies(struct clk *clk)
1077{
1078 unsigned long parent_accuracy = 0;
1079 struct clk *child;
1080
1081 if (clk->parent)
1082 parent_accuracy = clk->parent->accuracy;
1083
1084 if (clk->ops->recalc_accuracy)
1085 clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
1086 parent_accuracy);
1087 else
1088 clk->accuracy = parent_accuracy;
1089
1090 hlist_for_each_entry(child, &clk->children, child_node)
1091 __clk_recalc_accuracies(child);
1092}
1093
1094/**
1095 * clk_get_accuracy - return the accuracy of clk
1096 * @clk: the clk whose accuracy is being returned
1097 *
1098 * Simply returns the cached accuracy of the clk, unless
1099 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1100 * issued.
1101 * If clk is NULL then returns 0.
1102 */
1103long clk_get_accuracy(struct clk *clk)
1104{
1105 unsigned long accuracy;
1106
1107 clk_prepare_lock();
1108 if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE))
1109 __clk_recalc_accuracies(clk);
1110
1111 accuracy = __clk_get_accuracy(clk);
1112 clk_prepare_unlock();
1113
1114 return accuracy;
1115}
1116EXPORT_SYMBOL_GPL(clk_get_accuracy);
1117
b2476490
MT
1118/**
1119 * __clk_recalc_rates
1120 * @clk: first clk in the subtree
1121 * @msg: notification type (see include/linux/clk.h)
1122 *
1123 * Walks the subtree of clks starting with clk and recalculates rates as it
1124 * goes. Note that if a clk does not implement the .recalc_rate callback then
24ee1a08 1125 * it is assumed that the clock will take on the rate of its parent.
b2476490
MT
1126 *
1127 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1128 * if necessary.
1129 *
1130 * Caller must hold prepare_lock.
1131 */
1132static void __clk_recalc_rates(struct clk *clk, unsigned long msg)
1133{
1134 unsigned long old_rate;
1135 unsigned long parent_rate = 0;
b2476490
MT
1136 struct clk *child;
1137
1138 old_rate = clk->rate;
1139
1140 if (clk->parent)
1141 parent_rate = clk->parent->rate;
1142
1143 if (clk->ops->recalc_rate)
1144 clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate);
1145 else
1146 clk->rate = parent_rate;
1147
1148 /*
1149 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1150 * & ABORT_RATE_CHANGE notifiers
1151 */
1152 if (clk->notifier_count && msg)
1153 __clk_notify(clk, msg, old_rate, clk->rate);
1154
b67bfe0d 1155 hlist_for_each_entry(child, &clk->children, child_node)
b2476490
MT
1156 __clk_recalc_rates(child, msg);
1157}
1158
a093bde2
UH
1159/**
1160 * clk_get_rate - return the rate of clk
1161 * @clk: the clk whose rate is being returned
1162 *
1163 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1164 * is set, which means a recalc_rate will be issued.
1165 * If clk is NULL then returns 0.
1166 */
1167unsigned long clk_get_rate(struct clk *clk)
1168{
1169 unsigned long rate;
1170
eab89f69 1171 clk_prepare_lock();
a093bde2
UH
1172
1173 if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
1174 __clk_recalc_rates(clk, 0);
1175
1176 rate = __clk_get_rate(clk);
eab89f69 1177 clk_prepare_unlock();
a093bde2
UH
1178
1179 return rate;
1180}
1181EXPORT_SYMBOL_GPL(clk_get_rate);
1182
f1c8b2ed 1183static int clk_fetch_parent_index(struct clk *clk, struct clk *parent)
4935b22c 1184{
f1c8b2ed 1185 int i;
4935b22c 1186
f1c8b2ed 1187 if (!clk->parents) {
96a7ed90
TF
1188 clk->parents = kcalloc(clk->num_parents,
1189 sizeof(struct clk *), GFP_KERNEL);
f1c8b2ed
TF
1190 if (!clk->parents)
1191 return -ENOMEM;
1192 }
4935b22c
JH
1193
1194 /*
1195 * find index of new parent clock using cached parent ptrs,
1196 * or if not yet cached, use string name comparison and cache
1197 * them now to avoid future calls to __clk_lookup.
1198 */
1199 for (i = 0; i < clk->num_parents; i++) {
da0f0b2c 1200 if (clk->parents[i] == parent)
f1c8b2ed 1201 return i;
da0f0b2c
TF
1202
1203 if (clk->parents[i])
1204 continue;
1205
1206 if (!strcmp(clk->parent_names[i], parent->name)) {
1207 clk->parents[i] = __clk_lookup(parent->name);
f1c8b2ed 1208 return i;
4935b22c
JH
1209 }
1210 }
1211
f1c8b2ed 1212 return -EINVAL;
4935b22c
JH
1213}
1214
1215static void clk_reparent(struct clk *clk, struct clk *new_parent)
1216{
1217 hlist_del(&clk->child_node);
1218
903efc55
JH
1219 if (new_parent) {
1220 /* avoid duplicate POST_RATE_CHANGE notifications */
1221 if (new_parent->new_child == clk)
1222 new_parent->new_child = NULL;
1223
4935b22c 1224 hlist_add_head(&clk->child_node, &new_parent->children);
903efc55 1225 } else {
4935b22c 1226 hlist_add_head(&clk->child_node, &clk_orphan_list);
903efc55 1227 }
4935b22c
JH
1228
1229 clk->parent = new_parent;
1230}
1231
3fa2252b 1232static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent)
4935b22c
JH
1233{
1234 unsigned long flags;
4935b22c
JH
1235 struct clk *old_parent = clk->parent;
1236
1237 /*
1238 * Migrate prepare state between parents and prevent race with
1239 * clk_enable().
1240 *
1241 * If the clock is not prepared, then a race with
1242 * clk_enable/disable() is impossible since we already have the
1243 * prepare lock (future calls to clk_enable() need to be preceded by
1244 * a clk_prepare()).
1245 *
1246 * If the clock is prepared, migrate the prepared state to the new
1247 * parent and also protect against a race with clk_enable() by
1248 * forcing the clock and the new parent on. This ensures that all
1249 * future calls to clk_enable() are practically NOPs with respect to
1250 * hardware and software states.
1251 *
1252 * See also: Comment for clk_set_parent() below.
1253 */
1254 if (clk->prepare_count) {
1255 __clk_prepare(parent);
1256 clk_enable(parent);
1257 clk_enable(clk);
1258 }
1259
1260 /* update the clk tree topology */
1261 flags = clk_enable_lock();
1262 clk_reparent(clk, parent);
1263 clk_enable_unlock(flags);
1264
3fa2252b
SB
1265 return old_parent;
1266}
1267
1268static void __clk_set_parent_after(struct clk *clk, struct clk *parent,
1269 struct clk *old_parent)
1270{
1271 /*
1272 * Finish the migration of prepare state and undo the changes done
1273 * for preventing a race with clk_enable().
1274 */
1275 if (clk->prepare_count) {
1276 clk_disable(clk);
1277 clk_disable(old_parent);
1278 __clk_unprepare(old_parent);
1279 }
1280
1281 /* update debugfs with new clk tree topology */
1282 clk_debug_reparent(clk, parent);
1283}
1284
1285static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index)
1286{
1287 unsigned long flags;
1288 int ret = 0;
1289 struct clk *old_parent;
1290
1291 old_parent = __clk_set_parent_before(clk, parent);
1292
4935b22c
JH
1293 /* change clock input source */
1294 if (parent && clk->ops->set_parent)
1295 ret = clk->ops->set_parent(clk->hw, p_index);
1296
1297 if (ret) {
1298 flags = clk_enable_lock();
1299 clk_reparent(clk, old_parent);
1300 clk_enable_unlock(flags);
1301
1302 if (clk->prepare_count) {
1303 clk_disable(clk);
1304 clk_disable(parent);
1305 __clk_unprepare(parent);
1306 }
1307 return ret;
1308 }
1309
3fa2252b 1310 __clk_set_parent_after(clk, parent, old_parent);
4935b22c 1311
4935b22c
JH
1312 return 0;
1313}
1314
b2476490
MT
1315/**
1316 * __clk_speculate_rates
1317 * @clk: first clk in the subtree
1318 * @parent_rate: the "future" rate of clk's parent
1319 *
1320 * Walks the subtree of clks starting with clk, speculating rates as it
1321 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
1322 *
1323 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
1324 * pre-rate change notifications and returns early if no clks in the
1325 * subtree have subscribed to the notifications. Note that if a clk does not
1326 * implement the .recalc_rate callback then it is assumed that the clock will
24ee1a08 1327 * take on the rate of its parent.
b2476490
MT
1328 *
1329 * Caller must hold prepare_lock.
1330 */
1331static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate)
1332{
b2476490
MT
1333 struct clk *child;
1334 unsigned long new_rate;
1335 int ret = NOTIFY_DONE;
1336
1337 if (clk->ops->recalc_rate)
1338 new_rate = clk->ops->recalc_rate(clk->hw, parent_rate);
1339 else
1340 new_rate = parent_rate;
1341
fb72a059 1342 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
b2476490
MT
1343 if (clk->notifier_count)
1344 ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate);
1345
86bcfa2e
MT
1346 if (ret & NOTIFY_STOP_MASK) {
1347 pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
1348 __func__, clk->name, ret);
b2476490 1349 goto out;
86bcfa2e 1350 }
b2476490 1351
b67bfe0d 1352 hlist_for_each_entry(child, &clk->children, child_node) {
b2476490 1353 ret = __clk_speculate_rates(child, new_rate);
fb72a059 1354 if (ret & NOTIFY_STOP_MASK)
b2476490
MT
1355 break;
1356 }
1357
1358out:
1359 return ret;
1360}
1361
71472c0c
JH
1362static void clk_calc_subtree(struct clk *clk, unsigned long new_rate,
1363 struct clk *new_parent, u8 p_index)
b2476490
MT
1364{
1365 struct clk *child;
b2476490
MT
1366
1367 clk->new_rate = new_rate;
71472c0c
JH
1368 clk->new_parent = new_parent;
1369 clk->new_parent_index = p_index;
1370 /* include clk in new parent's PRE_RATE_CHANGE notifications */
1371 clk->new_child = NULL;
1372 if (new_parent && new_parent != clk->parent)
1373 new_parent->new_child = clk;
b2476490 1374
b67bfe0d 1375 hlist_for_each_entry(child, &clk->children, child_node) {
b2476490
MT
1376 if (child->ops->recalc_rate)
1377 child->new_rate = child->ops->recalc_rate(child->hw, new_rate);
1378 else
1379 child->new_rate = new_rate;
71472c0c 1380 clk_calc_subtree(child, child->new_rate, NULL, 0);
b2476490
MT
1381 }
1382}
1383
1384/*
1385 * calculate the new rates returning the topmost clock that has to be
1386 * changed.
1387 */
1388static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
1389{
1390 struct clk *top = clk;
71472c0c 1391 struct clk *old_parent, *parent;
81536e07 1392 unsigned long best_parent_rate = 0;
b2476490 1393 unsigned long new_rate;
f1c8b2ed 1394 int p_index = 0;
b2476490 1395
7452b219
MT
1396 /* sanity */
1397 if (IS_ERR_OR_NULL(clk))
1398 return NULL;
1399
63f5c3b2 1400 /* save parent rate, if it exists */
71472c0c
JH
1401 parent = old_parent = clk->parent;
1402 if (parent)
1403 best_parent_rate = parent->rate;
1404
1405 /* find the closest rate and parent clk/rate */
1406 if (clk->ops->determine_rate) {
1407 new_rate = clk->ops->determine_rate(clk->hw, rate,
1408 &best_parent_rate,
1409 &parent);
1410 } else if (clk->ops->round_rate) {
1411 new_rate = clk->ops->round_rate(clk->hw, rate,
1412 &best_parent_rate);
1413 } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) {
1414 /* pass-through clock without adjustable parent */
1415 clk->new_rate = clk->rate;
1416 return NULL;
1417 } else {
1418 /* pass-through clock with adjustable parent */
1419 top = clk_calc_new_rates(parent, rate);
1420 new_rate = parent->new_rate;
63f5c3b2 1421 goto out;
7452b219
MT
1422 }
1423
71472c0c
JH
1424 /* some clocks must be gated to change parent */
1425 if (parent != old_parent &&
1426 (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
1427 pr_debug("%s: %s not gated but wants to reparent\n",
1428 __func__, clk->name);
b2476490
MT
1429 return NULL;
1430 }
1431
71472c0c
JH
1432 /* try finding the new parent index */
1433 if (parent) {
1434 p_index = clk_fetch_parent_index(clk, parent);
f1c8b2ed 1435 if (p_index < 0) {
71472c0c
JH
1436 pr_debug("%s: clk %s can not be parent of clk %s\n",
1437 __func__, parent->name, clk->name);
1438 return NULL;
1439 }
b2476490
MT
1440 }
1441
71472c0c
JH
1442 if ((clk->flags & CLK_SET_RATE_PARENT) && parent &&
1443 best_parent_rate != parent->rate)
1444 top = clk_calc_new_rates(parent, best_parent_rate);
b2476490
MT
1445
1446out:
71472c0c 1447 clk_calc_subtree(clk, new_rate, parent, p_index);
b2476490
MT
1448
1449 return top;
1450}
1451
1452/*
1453 * Notify about rate changes in a subtree. Always walk down the whole tree
1454 * so that in case of an error we can walk down the whole tree again and
1455 * abort the change.
1456 */
1457static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event)
1458{
71472c0c 1459 struct clk *child, *tmp_clk, *fail_clk = NULL;
b2476490
MT
1460 int ret = NOTIFY_DONE;
1461
1462 if (clk->rate == clk->new_rate)
5fda6858 1463 return NULL;
b2476490
MT
1464
1465 if (clk->notifier_count) {
1466 ret = __clk_notify(clk, event, clk->rate, clk->new_rate);
fb72a059 1467 if (ret & NOTIFY_STOP_MASK)
b2476490
MT
1468 fail_clk = clk;
1469 }
1470
b67bfe0d 1471 hlist_for_each_entry(child, &clk->children, child_node) {
71472c0c
JH
1472 /* Skip children who will be reparented to another clock */
1473 if (child->new_parent && child->new_parent != clk)
1474 continue;
1475 tmp_clk = clk_propagate_rate_change(child, event);
1476 if (tmp_clk)
1477 fail_clk = tmp_clk;
1478 }
1479
1480 /* handle the new child who might not be in clk->children yet */
1481 if (clk->new_child) {
1482 tmp_clk = clk_propagate_rate_change(clk->new_child, event);
1483 if (tmp_clk)
1484 fail_clk = tmp_clk;
b2476490
MT
1485 }
1486
1487 return fail_clk;
1488}
1489
1490/*
1491 * walk down a subtree and set the new rates notifying the rate
1492 * change on the way
1493 */
1494static void clk_change_rate(struct clk *clk)
1495{
1496 struct clk *child;
1497 unsigned long old_rate;
bf47b4fd 1498 unsigned long best_parent_rate = 0;
3fa2252b
SB
1499 bool skip_set_rate = false;
1500 struct clk *old_parent;
b2476490
MT
1501
1502 old_rate = clk->rate;
1503
3fa2252b
SB
1504 if (clk->new_parent)
1505 best_parent_rate = clk->new_parent->rate;
1506 else if (clk->parent)
bf47b4fd
PM
1507 best_parent_rate = clk->parent->rate;
1508
3fa2252b
SB
1509 if (clk->new_parent && clk->new_parent != clk->parent) {
1510 old_parent = __clk_set_parent_before(clk, clk->new_parent);
1511
1512 if (clk->ops->set_rate_and_parent) {
1513 skip_set_rate = true;
1514 clk->ops->set_rate_and_parent(clk->hw, clk->new_rate,
1515 best_parent_rate,
1516 clk->new_parent_index);
1517 } else if (clk->ops->set_parent) {
1518 clk->ops->set_parent(clk->hw, clk->new_parent_index);
1519 }
1520
1521 __clk_set_parent_after(clk, clk->new_parent, old_parent);
1522 }
1523
1524 if (!skip_set_rate && clk->ops->set_rate)
bf47b4fd 1525 clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
b2476490
MT
1526
1527 if (clk->ops->recalc_rate)
bf47b4fd 1528 clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate);
b2476490 1529 else
bf47b4fd 1530 clk->rate = best_parent_rate;
b2476490
MT
1531
1532 if (clk->notifier_count && old_rate != clk->rate)
1533 __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
1534
71472c0c
JH
1535 hlist_for_each_entry(child, &clk->children, child_node) {
1536 /* Skip children who will be reparented to another clock */
1537 if (child->new_parent && child->new_parent != clk)
1538 continue;
b2476490 1539 clk_change_rate(child);
71472c0c
JH
1540 }
1541
1542 /* handle the new child who might not be in clk->children yet */
1543 if (clk->new_child)
1544 clk_change_rate(clk->new_child);
b2476490
MT
1545}
1546
1547/**
1548 * clk_set_rate - specify a new rate for clk
1549 * @clk: the clk whose rate is being changed
1550 * @rate: the new rate for clk
1551 *
5654dc94 1552 * In the simplest case clk_set_rate will only adjust the rate of clk.
b2476490 1553 *
5654dc94
MT
1554 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
1555 * propagate up to clk's parent; whether or not this happens depends on the
1556 * outcome of clk's .round_rate implementation. If *parent_rate is unchanged
1557 * after calling .round_rate then upstream parent propagation is ignored. If
1558 * *parent_rate comes back with a new rate for clk's parent then we propagate
24ee1a08 1559 * up to clk's parent and set its rate. Upward propagation will continue
5654dc94
MT
1560 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
1561 * .round_rate stops requesting changes to clk's parent_rate.
b2476490 1562 *
5654dc94
MT
1563 * Rate changes are accomplished via tree traversal that also recalculates the
1564 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
b2476490
MT
1565 *
1566 * Returns 0 on success, -EERROR otherwise.
1567 */
1568int clk_set_rate(struct clk *clk, unsigned long rate)
1569{
1570 struct clk *top, *fail_clk;
1571 int ret = 0;
1572
89ac8d7a
MT
1573 if (!clk)
1574 return 0;
1575
b2476490 1576 /* prevent racing with updates to the clock topology */
eab89f69 1577 clk_prepare_lock();
b2476490
MT
1578
1579 /* bail early if nothing to do */
34e452a1 1580 if (rate == clk_get_rate(clk))
b2476490
MT
1581 goto out;
1582
7e0fa1b5 1583 if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) {
0e1c0301
VK
1584 ret = -EBUSY;
1585 goto out;
1586 }
1587
b2476490
MT
1588 /* calculate new rates and get the topmost changed clock */
1589 top = clk_calc_new_rates(clk, rate);
1590 if (!top) {
1591 ret = -EINVAL;
1592 goto out;
1593 }
1594
1595 /* notify that we are about to change rates */
1596 fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
1597 if (fail_clk) {
f7363861 1598 pr_debug("%s: failed to set %s rate\n", __func__,
b2476490
MT
1599 fail_clk->name);
1600 clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
1601 ret = -EBUSY;
1602 goto out;
1603 }
1604
1605 /* change the rates */
1606 clk_change_rate(top);
1607
b2476490 1608out:
eab89f69 1609 clk_prepare_unlock();
b2476490
MT
1610
1611 return ret;
1612}
1613EXPORT_SYMBOL_GPL(clk_set_rate);
1614
1615/**
1616 * clk_get_parent - return the parent of a clk
1617 * @clk: the clk whose parent gets returned
1618 *
1619 * Simply returns clk->parent. Returns NULL if clk is NULL.
1620 */
1621struct clk *clk_get_parent(struct clk *clk)
1622{
1623 struct clk *parent;
1624
eab89f69 1625 clk_prepare_lock();
b2476490 1626 parent = __clk_get_parent(clk);
eab89f69 1627 clk_prepare_unlock();
b2476490
MT
1628
1629 return parent;
1630}
1631EXPORT_SYMBOL_GPL(clk_get_parent);
1632
1633/*
1634 * .get_parent is mandatory for clocks with multiple possible parents. It is
1635 * optional for single-parent clocks. Always call .get_parent if it is
1636 * available and WARN if it is missing for multi-parent clocks.
1637 *
1638 * For single-parent clocks without .get_parent, first check to see if the
1639 * .parents array exists, and if so use it to avoid an expensive tree
1640 * traversal. If .parents does not exist then walk the tree with __clk_lookup.
1641 */
1642static struct clk *__clk_init_parent(struct clk *clk)
1643{
1644 struct clk *ret = NULL;
1645 u8 index;
1646
1647 /* handle the trivial cases */
1648
1649 if (!clk->num_parents)
1650 goto out;
1651
1652 if (clk->num_parents == 1) {
1653 if (IS_ERR_OR_NULL(clk->parent))
1654 ret = clk->parent = __clk_lookup(clk->parent_names[0]);
1655 ret = clk->parent;
1656 goto out;
1657 }
1658
1659 if (!clk->ops->get_parent) {
1660 WARN(!clk->ops->get_parent,
1661 "%s: multi-parent clocks must implement .get_parent\n",
1662 __func__);
1663 goto out;
1664 };
1665
1666 /*
1667 * Do our best to cache parent clocks in clk->parents. This prevents
1668 * unnecessary and expensive calls to __clk_lookup. We don't set
1669 * clk->parent here; that is done by the calling function
1670 */
1671
1672 index = clk->ops->get_parent(clk->hw);
1673
1674 if (!clk->parents)
1675 clk->parents =
96a7ed90 1676 kcalloc(clk->num_parents, sizeof(struct clk *),
b2476490
MT
1677 GFP_KERNEL);
1678
7ef3dcc8 1679 ret = clk_get_parent_by_index(clk, index);
b2476490
MT
1680
1681out:
1682 return ret;
1683}
1684
b33d212f
UH
1685void __clk_reparent(struct clk *clk, struct clk *new_parent)
1686{
1687 clk_reparent(clk, new_parent);
1688 clk_debug_reparent(clk, new_parent);
5279fc40 1689 __clk_recalc_accuracies(clk);
b2476490
MT
1690 __clk_recalc_rates(clk, POST_RATE_CHANGE);
1691}
1692
b2476490
MT
1693/**
1694 * clk_set_parent - switch the parent of a mux clk
1695 * @clk: the mux clk whose input we are switching
1696 * @parent: the new input to clk
1697 *
f8aa0bd5
SK
1698 * Re-parent clk to use parent as its new input source. If clk is in
1699 * prepared state, the clk will get enabled for the duration of this call. If
1700 * that's not acceptable for a specific clk (Eg: the consumer can't handle
1701 * that, the reparenting is glitchy in hardware, etc), use the
1702 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
1703 *
1704 * After successfully changing clk's parent clk_set_parent will update the
1705 * clk topology, sysfs topology and propagate rate recalculation via
1706 * __clk_recalc_rates.
1707 *
1708 * Returns 0 on success, -EERROR otherwise.
b2476490
MT
1709 */
1710int clk_set_parent(struct clk *clk, struct clk *parent)
1711{
1712 int ret = 0;
f1c8b2ed 1713 int p_index = 0;
031dcc9b 1714 unsigned long p_rate = 0;
b2476490 1715
89ac8d7a
MT
1716 if (!clk)
1717 return 0;
1718
031dcc9b
UH
1719 /* verify ops for for multi-parent clks */
1720 if ((clk->num_parents > 1) && (!clk->ops->set_parent))
b2476490
MT
1721 return -ENOSYS;
1722
1723 /* prevent racing with updates to the clock topology */
eab89f69 1724 clk_prepare_lock();
b2476490
MT
1725
1726 if (clk->parent == parent)
1727 goto out;
1728
031dcc9b
UH
1729 /* check that we are allowed to re-parent if the clock is in use */
1730 if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
1731 ret = -EBUSY;
1732 goto out;
1733 }
1734
1735 /* try finding the new parent index */
1736 if (parent) {
1737 p_index = clk_fetch_parent_index(clk, parent);
1738 p_rate = parent->rate;
f1c8b2ed 1739 if (p_index < 0) {
031dcc9b
UH
1740 pr_debug("%s: clk %s can not be parent of clk %s\n",
1741 __func__, parent->name, clk->name);
f1c8b2ed 1742 ret = p_index;
031dcc9b
UH
1743 goto out;
1744 }
1745 }
1746
b2476490 1747 /* propagate PRE_RATE_CHANGE notifications */
f3aab5d6 1748 ret = __clk_speculate_rates(clk, p_rate);
b2476490
MT
1749
1750 /* abort if a driver objects */
fb72a059 1751 if (ret & NOTIFY_STOP_MASK)
b2476490
MT
1752 goto out;
1753
031dcc9b
UH
1754 /* do the re-parent */
1755 ret = __clk_set_parent(clk, parent, p_index);
b2476490 1756
5279fc40
BB
1757 /* propagate rate an accuracy recalculation accordingly */
1758 if (ret) {
b2476490 1759 __clk_recalc_rates(clk, ABORT_RATE_CHANGE);
5279fc40 1760 } else {
a68de8e4 1761 __clk_recalc_rates(clk, POST_RATE_CHANGE);
5279fc40
BB
1762 __clk_recalc_accuracies(clk);
1763 }
b2476490
MT
1764
1765out:
eab89f69 1766 clk_prepare_unlock();
b2476490
MT
1767
1768 return ret;
1769}
1770EXPORT_SYMBOL_GPL(clk_set_parent);
1771
1772/**
1773 * __clk_init - initialize the data structures in a struct clk
1774 * @dev: device initializing this clk, placeholder for now
1775 * @clk: clk being initialized
1776 *
1777 * Initializes the lists in struct clk, queries the hardware for the
1778 * parent and rate and sets them both.
b2476490 1779 */
d1302a36 1780int __clk_init(struct device *dev, struct clk *clk)
b2476490 1781{
d1302a36 1782 int i, ret = 0;
b2476490 1783 struct clk *orphan;
b67bfe0d 1784 struct hlist_node *tmp2;
b2476490
MT
1785
1786 if (!clk)
d1302a36 1787 return -EINVAL;
b2476490 1788
eab89f69 1789 clk_prepare_lock();
b2476490
MT
1790
1791 /* check to see if a clock with this name is already registered */
d1302a36
MT
1792 if (__clk_lookup(clk->name)) {
1793 pr_debug("%s: clk %s already initialized\n",
1794 __func__, clk->name);
1795 ret = -EEXIST;
b2476490 1796 goto out;
d1302a36 1797 }
b2476490 1798
d4d7e3dd
MT
1799 /* check that clk_ops are sane. See Documentation/clk.txt */
1800 if (clk->ops->set_rate &&
71472c0c
JH
1801 !((clk->ops->round_rate || clk->ops->determine_rate) &&
1802 clk->ops->recalc_rate)) {
1803 pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
d4d7e3dd 1804 __func__, clk->name);
d1302a36 1805 ret = -EINVAL;
d4d7e3dd
MT
1806 goto out;
1807 }
1808
1809 if (clk->ops->set_parent && !clk->ops->get_parent) {
1810 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
1811 __func__, clk->name);
d1302a36 1812 ret = -EINVAL;
d4d7e3dd
MT
1813 goto out;
1814 }
1815
3fa2252b
SB
1816 if (clk->ops->set_rate_and_parent &&
1817 !(clk->ops->set_parent && clk->ops->set_rate)) {
1818 pr_warn("%s: %s must implement .set_parent & .set_rate\n",
1819 __func__, clk->name);
1820 ret = -EINVAL;
1821 goto out;
1822 }
1823
b2476490
MT
1824 /* throw a WARN if any entries in parent_names are NULL */
1825 for (i = 0; i < clk->num_parents; i++)
1826 WARN(!clk->parent_names[i],
1827 "%s: invalid NULL in %s's .parent_names\n",
1828 __func__, clk->name);
1829
1830 /*
1831 * Allocate an array of struct clk *'s to avoid unnecessary string
1832 * look-ups of clk's possible parents. This can fail for clocks passed
1833 * in to clk_init during early boot; thus any access to clk->parents[]
1834 * must always check for a NULL pointer and try to populate it if
1835 * necessary.
1836 *
1837 * If clk->parents is not NULL we skip this entire block. This allows
1838 * for clock drivers to statically initialize clk->parents.
1839 */
9ca1c5a4 1840 if (clk->num_parents > 1 && !clk->parents) {
96a7ed90
TF
1841 clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *),
1842 GFP_KERNEL);
b2476490
MT
1843 /*
1844 * __clk_lookup returns NULL for parents that have not been
1845 * clk_init'd; thus any access to clk->parents[] must check
1846 * for a NULL pointer. We can always perform lazy lookups for
1847 * missing parents later on.
1848 */
1849 if (clk->parents)
1850 for (i = 0; i < clk->num_parents; i++)
1851 clk->parents[i] =
1852 __clk_lookup(clk->parent_names[i]);
1853 }
1854
1855 clk->parent = __clk_init_parent(clk);
1856
1857 /*
1858 * Populate clk->parent if parent has already been __clk_init'd. If
1859 * parent has not yet been __clk_init'd then place clk in the orphan
1860 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
1861 * clk list.
1862 *
1863 * Every time a new clk is clk_init'd then we walk the list of orphan
1864 * clocks and re-parent any that are children of the clock currently
1865 * being clk_init'd.
1866 */
1867 if (clk->parent)
1868 hlist_add_head(&clk->child_node,
1869 &clk->parent->children);
1870 else if (clk->flags & CLK_IS_ROOT)
1871 hlist_add_head(&clk->child_node, &clk_root_list);
1872 else
1873 hlist_add_head(&clk->child_node, &clk_orphan_list);
1874
5279fc40
BB
1875 /*
1876 * Set clk's accuracy. The preferred method is to use
1877 * .recalc_accuracy. For simple clocks and lazy developers the default
1878 * fallback is to use the parent's accuracy. If a clock doesn't have a
1879 * parent (or is orphaned) then accuracy is set to zero (perfect
1880 * clock).
1881 */
1882 if (clk->ops->recalc_accuracy)
1883 clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
1884 __clk_get_accuracy(clk->parent));
1885 else if (clk->parent)
1886 clk->accuracy = clk->parent->accuracy;
1887 else
1888 clk->accuracy = 0;
1889
b2476490
MT
1890 /*
1891 * Set clk's rate. The preferred method is to use .recalc_rate. For
1892 * simple clocks and lazy developers the default fallback is to use the
1893 * parent's rate. If a clock doesn't have a parent (or is orphaned)
1894 * then rate is set to zero.
1895 */
1896 if (clk->ops->recalc_rate)
1897 clk->rate = clk->ops->recalc_rate(clk->hw,
1898 __clk_get_rate(clk->parent));
1899 else if (clk->parent)
1900 clk->rate = clk->parent->rate;
1901 else
1902 clk->rate = 0;
1903
3a5aec24 1904 clk_debug_register(clk);
b2476490
MT
1905 /*
1906 * walk the list of orphan clocks and reparent any that are children of
1907 * this clock
1908 */
b67bfe0d 1909 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
12d29886 1910 if (orphan->num_parents && orphan->ops->get_parent) {
1f61e5f1
MF
1911 i = orphan->ops->get_parent(orphan->hw);
1912 if (!strcmp(clk->name, orphan->parent_names[i]))
1913 __clk_reparent(orphan, clk);
1914 continue;
1915 }
1916
b2476490
MT
1917 for (i = 0; i < orphan->num_parents; i++)
1918 if (!strcmp(clk->name, orphan->parent_names[i])) {
1919 __clk_reparent(orphan, clk);
1920 break;
1921 }
1f61e5f1 1922 }
b2476490
MT
1923
1924 /*
1925 * optional platform-specific magic
1926 *
1927 * The .init callback is not used by any of the basic clock types, but
1928 * exists for weird hardware that must perform initialization magic.
1929 * Please consider other ways of solving initialization problems before
24ee1a08 1930 * using this callback, as its use is discouraged.
b2476490
MT
1931 */
1932 if (clk->ops->init)
1933 clk->ops->init(clk->hw);
1934
fcb0ee6a 1935 kref_init(&clk->ref);
b2476490 1936out:
eab89f69 1937 clk_prepare_unlock();
b2476490 1938
d1302a36 1939 return ret;
b2476490
MT
1940}
1941
0197b3ea
SK
1942/**
1943 * __clk_register - register a clock and return a cookie.
1944 *
1945 * Same as clk_register, except that the .clk field inside hw shall point to a
1946 * preallocated (generally statically allocated) struct clk. None of the fields
1947 * of the struct clk need to be initialized.
1948 *
1949 * The data pointed to by .init and .clk field shall NOT be marked as init
1950 * data.
1951 *
1952 * __clk_register is only exposed via clk-private.h and is intended for use with
1953 * very large numbers of clocks that need to be statically initialized. It is
1954 * a layering violation to include clk-private.h from any code which implements
1955 * a clock's .ops; as such any statically initialized clock data MUST be in a
24ee1a08 1956 * separate C file from the logic that implements its operations. Returns 0
0197b3ea
SK
1957 * on success, otherwise an error code.
1958 */
1959struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
1960{
1961 int ret;
1962 struct clk *clk;
1963
1964 clk = hw->clk;
1965 clk->name = hw->init->name;
1966 clk->ops = hw->init->ops;
1967 clk->hw = hw;
1968 clk->flags = hw->init->flags;
1969 clk->parent_names = hw->init->parent_names;
1970 clk->num_parents = hw->init->num_parents;
ac2df527
SN
1971 if (dev && dev->driver)
1972 clk->owner = dev->driver->owner;
1973 else
1974 clk->owner = NULL;
0197b3ea
SK
1975
1976 ret = __clk_init(dev, clk);
1977 if (ret)
1978 return ERR_PTR(ret);
1979
1980 return clk;
1981}
1982EXPORT_SYMBOL_GPL(__clk_register);
1983
293ba3b4
SB
1984/**
1985 * clk_register - allocate a new clock, register it and return an opaque cookie
1986 * @dev: device that is registering this clock
1987 * @hw: link to hardware-specific clock data
1988 *
1989 * clk_register is the primary interface for populating the clock tree with new
1990 * clock nodes. It returns a pointer to the newly allocated struct clk which
1991 * cannot be dereferenced by driver code but may be used in conjuction with the
1992 * rest of the clock API. In the event of an error clk_register will return an
1993 * error code; drivers must test for an error code after calling clk_register.
1994 */
1995struct clk *clk_register(struct device *dev, struct clk_hw *hw)
b2476490 1996{
d1302a36 1997 int i, ret;
293ba3b4
SB
1998 struct clk *clk;
1999
2000 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2001 if (!clk) {
2002 pr_err("%s: could not allocate clk\n", __func__);
2003 ret = -ENOMEM;
2004 goto fail_out;
2005 }
b2476490 2006
0197b3ea
SK
2007 clk->name = kstrdup(hw->init->name, GFP_KERNEL);
2008 if (!clk->name) {
2009 pr_err("%s: could not allocate clk->name\n", __func__);
2010 ret = -ENOMEM;
2011 goto fail_name;
2012 }
2013 clk->ops = hw->init->ops;
ac2df527
SN
2014 if (dev && dev->driver)
2015 clk->owner = dev->driver->owner;
b2476490 2016 clk->hw = hw;
0197b3ea
SK
2017 clk->flags = hw->init->flags;
2018 clk->num_parents = hw->init->num_parents;
b2476490
MT
2019 hw->clk = clk;
2020
d1302a36 2021 /* allocate local copy in case parent_names is __initdata */
96a7ed90
TF
2022 clk->parent_names = kcalloc(clk->num_parents, sizeof(char *),
2023 GFP_KERNEL);
d1302a36
MT
2024
2025 if (!clk->parent_names) {
2026 pr_err("%s: could not allocate clk->parent_names\n", __func__);
2027 ret = -ENOMEM;
2028 goto fail_parent_names;
2029 }
2030
2031
2032 /* copy each string name in case parent_names is __initdata */
0197b3ea
SK
2033 for (i = 0; i < clk->num_parents; i++) {
2034 clk->parent_names[i] = kstrdup(hw->init->parent_names[i],
2035 GFP_KERNEL);
d1302a36
MT
2036 if (!clk->parent_names[i]) {
2037 pr_err("%s: could not copy parent_names\n", __func__);
2038 ret = -ENOMEM;
2039 goto fail_parent_names_copy;
2040 }
2041 }
2042
2043 ret = __clk_init(dev, clk);
2044 if (!ret)
293ba3b4 2045 return clk;
b2476490 2046
d1302a36
MT
2047fail_parent_names_copy:
2048 while (--i >= 0)
2049 kfree(clk->parent_names[i]);
2050 kfree(clk->parent_names);
2051fail_parent_names:
0197b3ea
SK
2052 kfree(clk->name);
2053fail_name:
d1302a36
MT
2054 kfree(clk);
2055fail_out:
2056 return ERR_PTR(ret);
b2476490
MT
2057}
2058EXPORT_SYMBOL_GPL(clk_register);
2059
fcb0ee6a
SN
2060/*
2061 * Free memory allocated for a clock.
2062 * Caller must hold prepare_lock.
2063 */
2064static void __clk_release(struct kref *ref)
2065{
2066 struct clk *clk = container_of(ref, struct clk, ref);
2067 int i = clk->num_parents;
2068
2069 kfree(clk->parents);
2070 while (--i >= 0)
2071 kfree(clk->parent_names[i]);
2072
2073 kfree(clk->parent_names);
2074 kfree(clk->name);
2075 kfree(clk);
2076}
2077
2078/*
2079 * Empty clk_ops for unregistered clocks. These are used temporarily
2080 * after clk_unregister() was called on a clock and until last clock
2081 * consumer calls clk_put() and the struct clk object is freed.
2082 */
2083static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2084{
2085 return -ENXIO;
2086}
2087
2088static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2089{
2090 WARN_ON_ONCE(1);
2091}
2092
2093static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2094 unsigned long parent_rate)
2095{
2096 return -ENXIO;
2097}
2098
2099static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2100{
2101 return -ENXIO;
2102}
2103
2104static const struct clk_ops clk_nodrv_ops = {
2105 .enable = clk_nodrv_prepare_enable,
2106 .disable = clk_nodrv_disable_unprepare,
2107 .prepare = clk_nodrv_prepare_enable,
2108 .unprepare = clk_nodrv_disable_unprepare,
2109 .set_rate = clk_nodrv_set_rate,
2110 .set_parent = clk_nodrv_set_parent,
2111};
2112
1df5c939
MB
2113/**
2114 * clk_unregister - unregister a currently registered clock
2115 * @clk: clock to unregister
1df5c939 2116 */
fcb0ee6a
SN
2117void clk_unregister(struct clk *clk)
2118{
2119 unsigned long flags;
2120
2121 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2122 return;
2123
2124 clk_prepare_lock();
2125
2126 if (clk->ops == &clk_nodrv_ops) {
2127 pr_err("%s: unregistered clock: %s\n", __func__, clk->name);
2128 goto out;
2129 }
2130 /*
2131 * Assign empty clock ops for consumers that might still hold
2132 * a reference to this clock.
2133 */
2134 flags = clk_enable_lock();
2135 clk->ops = &clk_nodrv_ops;
2136 clk_enable_unlock(flags);
2137
2138 if (!hlist_empty(&clk->children)) {
2139 struct clk *child;
874f224c 2140 struct hlist_node *t;
fcb0ee6a
SN
2141
2142 /* Reparent all children to the orphan list. */
874f224c 2143 hlist_for_each_entry_safe(child, t, &clk->children, child_node)
fcb0ee6a
SN
2144 clk_set_parent(child, NULL);
2145 }
2146
2147 clk_debug_unregister(clk);
2148
2149 hlist_del_init(&clk->child_node);
2150
2151 if (clk->prepare_count)
2152 pr_warn("%s: unregistering prepared clock: %s\n",
2153 __func__, clk->name);
2154
2155 kref_put(&clk->ref, __clk_release);
2156out:
2157 clk_prepare_unlock();
2158}
1df5c939
MB
2159EXPORT_SYMBOL_GPL(clk_unregister);
2160
46c8773a
SB
2161static void devm_clk_release(struct device *dev, void *res)
2162{
293ba3b4 2163 clk_unregister(*(struct clk **)res);
46c8773a
SB
2164}
2165
2166/**
2167 * devm_clk_register - resource managed clk_register()
2168 * @dev: device that is registering this clock
2169 * @hw: link to hardware-specific clock data
2170 *
2171 * Managed clk_register(). Clocks returned from this function are
2172 * automatically clk_unregister()ed on driver detach. See clk_register() for
2173 * more information.
2174 */
2175struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2176{
2177 struct clk *clk;
293ba3b4 2178 struct clk **clkp;
46c8773a 2179
293ba3b4
SB
2180 clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
2181 if (!clkp)
46c8773a
SB
2182 return ERR_PTR(-ENOMEM);
2183
293ba3b4
SB
2184 clk = clk_register(dev, hw);
2185 if (!IS_ERR(clk)) {
2186 *clkp = clk;
2187 devres_add(dev, clkp);
46c8773a 2188 } else {
293ba3b4 2189 devres_free(clkp);
46c8773a
SB
2190 }
2191
2192 return clk;
2193}
2194EXPORT_SYMBOL_GPL(devm_clk_register);
2195
2196static int devm_clk_match(struct device *dev, void *res, void *data)
2197{
2198 struct clk *c = res;
2199 if (WARN_ON(!c))
2200 return 0;
2201 return c == data;
2202}
2203
2204/**
2205 * devm_clk_unregister - resource managed clk_unregister()
2206 * @clk: clock to unregister
2207 *
2208 * Deallocate a clock allocated with devm_clk_register(). Normally
2209 * this function will not need to be called and the resource management
2210 * code will ensure that the resource is freed.
2211 */
2212void devm_clk_unregister(struct device *dev, struct clk *clk)
2213{
2214 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2215}
2216EXPORT_SYMBOL_GPL(devm_clk_unregister);
2217
ac2df527
SN
2218/*
2219 * clkdev helpers
2220 */
2221int __clk_get(struct clk *clk)
2222{
00efcb1c
SN
2223 if (clk) {
2224 if (!try_module_get(clk->owner))
2225 return 0;
ac2df527 2226
00efcb1c
SN
2227 kref_get(&clk->ref);
2228 }
ac2df527
SN
2229 return 1;
2230}
2231
2232void __clk_put(struct clk *clk)
2233{
00efcb1c 2234 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
ac2df527
SN
2235 return;
2236
fcb0ee6a
SN
2237 clk_prepare_lock();
2238 kref_put(&clk->ref, __clk_release);
2239 clk_prepare_unlock();
2240
00efcb1c 2241 module_put(clk->owner);
ac2df527
SN
2242}
2243
b2476490
MT
2244/*** clk rate change notifiers ***/
2245
2246/**
2247 * clk_notifier_register - add a clk rate change notifier
2248 * @clk: struct clk * to watch
2249 * @nb: struct notifier_block * with callback info
2250 *
2251 * Request notification when clk's rate changes. This uses an SRCU
2252 * notifier because we want it to block and notifier unregistrations are
2253 * uncommon. The callbacks associated with the notifier must not
2254 * re-enter into the clk framework by calling any top-level clk APIs;
2255 * this will cause a nested prepare_lock mutex.
2256 *
5324fda7
SB
2257 * In all notification cases cases (pre, post and abort rate change) the
2258 * original clock rate is passed to the callback via struct
2259 * clk_notifier_data.old_rate and the new frequency is passed via struct
b2476490
MT
2260 * clk_notifier_data.new_rate.
2261 *
b2476490
MT
2262 * clk_notifier_register() must be called from non-atomic context.
2263 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2264 * allocation failure; otherwise, passes along the return value of
2265 * srcu_notifier_chain_register().
2266 */
2267int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2268{
2269 struct clk_notifier *cn;
2270 int ret = -ENOMEM;
2271
2272 if (!clk || !nb)
2273 return -EINVAL;
2274
eab89f69 2275 clk_prepare_lock();
b2476490
MT
2276
2277 /* search the list of notifiers for this clk */
2278 list_for_each_entry(cn, &clk_notifier_list, node)
2279 if (cn->clk == clk)
2280 break;
2281
2282 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2283 if (cn->clk != clk) {
2284 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2285 if (!cn)
2286 goto out;
2287
2288 cn->clk = clk;
2289 srcu_init_notifier_head(&cn->notifier_head);
2290
2291 list_add(&cn->node, &clk_notifier_list);
2292 }
2293
2294 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2295
2296 clk->notifier_count++;
2297
2298out:
eab89f69 2299 clk_prepare_unlock();
b2476490
MT
2300
2301 return ret;
2302}
2303EXPORT_SYMBOL_GPL(clk_notifier_register);
2304
2305/**
2306 * clk_notifier_unregister - remove a clk rate change notifier
2307 * @clk: struct clk *
2308 * @nb: struct notifier_block * with callback info
2309 *
2310 * Request no further notification for changes to 'clk' and frees memory
2311 * allocated in clk_notifier_register.
2312 *
2313 * Returns -EINVAL if called with null arguments; otherwise, passes
2314 * along the return value of srcu_notifier_chain_unregister().
2315 */
2316int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2317{
2318 struct clk_notifier *cn = NULL;
2319 int ret = -EINVAL;
2320
2321 if (!clk || !nb)
2322 return -EINVAL;
2323
eab89f69 2324 clk_prepare_lock();
b2476490
MT
2325
2326 list_for_each_entry(cn, &clk_notifier_list, node)
2327 if (cn->clk == clk)
2328 break;
2329
2330 if (cn->clk == clk) {
2331 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2332
2333 clk->notifier_count--;
2334
2335 /* XXX the notifier code should handle this better */
2336 if (!cn->notifier_head.head) {
2337 srcu_cleanup_notifier_head(&cn->notifier_head);
72b5322f 2338 list_del(&cn->node);
b2476490
MT
2339 kfree(cn);
2340 }
2341
2342 } else {
2343 ret = -ENOENT;
2344 }
2345
eab89f69 2346 clk_prepare_unlock();
b2476490
MT
2347
2348 return ret;
2349}
2350EXPORT_SYMBOL_GPL(clk_notifier_unregister);
766e6a4e
GL
2351
2352#ifdef CONFIG_OF
2353/**
2354 * struct of_clk_provider - Clock provider registration structure
2355 * @link: Entry in global list of clock providers
2356 * @node: Pointer to device tree node of clock provider
2357 * @get: Get clock callback. Returns NULL or a struct clk for the
2358 * given clock specifier
2359 * @data: context pointer to be passed into @get callback
2360 */
2361struct of_clk_provider {
2362 struct list_head link;
2363
2364 struct device_node *node;
2365 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2366 void *data;
2367};
2368
f2f6c255
PG
2369static const struct of_device_id __clk_of_table_sentinel
2370 __used __section(__clk_of_table_end);
2371
766e6a4e 2372static LIST_HEAD(of_clk_providers);
d6782c26
SN
2373static DEFINE_MUTEX(of_clk_mutex);
2374
2375/* of_clk_provider list locking helpers */
2376void of_clk_lock(void)
2377{
2378 mutex_lock(&of_clk_mutex);
2379}
2380
2381void of_clk_unlock(void)
2382{
2383 mutex_unlock(&of_clk_mutex);
2384}
766e6a4e
GL
2385
2386struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2387 void *data)
2388{
2389 return data;
2390}
2391EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2392
494bfec9
SG
2393struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2394{
2395 struct clk_onecell_data *clk_data = data;
2396 unsigned int idx = clkspec->args[0];
2397
2398 if (idx >= clk_data->clk_num) {
2399 pr_err("%s: invalid clock index %d\n", __func__, idx);
2400 return ERR_PTR(-EINVAL);
2401 }
2402
2403 return clk_data->clks[idx];
2404}
2405EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2406
766e6a4e
GL
2407/**
2408 * of_clk_add_provider() - Register a clock provider for a node
2409 * @np: Device node pointer associated with clock provider
2410 * @clk_src_get: callback for decoding clock
2411 * @data: context pointer for @clk_src_get callback.
2412 */
2413int of_clk_add_provider(struct device_node *np,
2414 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2415 void *data),
2416 void *data)
2417{
2418 struct of_clk_provider *cp;
2419
2420 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2421 if (!cp)
2422 return -ENOMEM;
2423
2424 cp->node = of_node_get(np);
2425 cp->data = data;
2426 cp->get = clk_src_get;
2427
d6782c26 2428 mutex_lock(&of_clk_mutex);
766e6a4e 2429 list_add(&cp->link, &of_clk_providers);
d6782c26 2430 mutex_unlock(&of_clk_mutex);
766e6a4e
GL
2431 pr_debug("Added clock from %s\n", np->full_name);
2432
2433 return 0;
2434}
2435EXPORT_SYMBOL_GPL(of_clk_add_provider);
2436
2437/**
2438 * of_clk_del_provider() - Remove a previously registered clock provider
2439 * @np: Device node pointer associated with clock provider
2440 */
2441void of_clk_del_provider(struct device_node *np)
2442{
2443 struct of_clk_provider *cp;
2444
d6782c26 2445 mutex_lock(&of_clk_mutex);
766e6a4e
GL
2446 list_for_each_entry(cp, &of_clk_providers, link) {
2447 if (cp->node == np) {
2448 list_del(&cp->link);
2449 of_node_put(cp->node);
2450 kfree(cp);
2451 break;
2452 }
2453 }
d6782c26 2454 mutex_unlock(&of_clk_mutex);
766e6a4e
GL
2455}
2456EXPORT_SYMBOL_GPL(of_clk_del_provider);
2457
d6782c26 2458struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec)
766e6a4e
GL
2459{
2460 struct of_clk_provider *provider;
a34cd466 2461 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
766e6a4e
GL
2462
2463 /* Check if we have such a provider in our array */
766e6a4e
GL
2464 list_for_each_entry(provider, &of_clk_providers, link) {
2465 if (provider->node == clkspec->np)
2466 clk = provider->get(clkspec, provider->data);
2467 if (!IS_ERR(clk))
2468 break;
2469 }
d6782c26
SN
2470
2471 return clk;
2472}
2473
2474struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
2475{
2476 struct clk *clk;
2477
2478 mutex_lock(&of_clk_mutex);
2479 clk = __of_clk_get_from_provider(clkspec);
2480 mutex_unlock(&of_clk_mutex);
766e6a4e
GL
2481
2482 return clk;
2483}
2484
f6102742
MT
2485int of_clk_get_parent_count(struct device_node *np)
2486{
2487 return of_count_phandle_with_args(np, "clocks", "#clock-cells");
2488}
2489EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
2490
766e6a4e
GL
2491const char *of_clk_get_parent_name(struct device_node *np, int index)
2492{
2493 struct of_phandle_args clkspec;
7a0fc1a3 2494 struct property *prop;
766e6a4e 2495 const char *clk_name;
7a0fc1a3
BD
2496 const __be32 *vp;
2497 u32 pv;
766e6a4e 2498 int rc;
7a0fc1a3 2499 int count;
766e6a4e
GL
2500
2501 if (index < 0)
2502 return NULL;
2503
2504 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
2505 &clkspec);
2506 if (rc)
2507 return NULL;
2508
7a0fc1a3
BD
2509 index = clkspec.args_count ? clkspec.args[0] : 0;
2510 count = 0;
2511
2512 /* if there is an indices property, use it to transfer the index
2513 * specified into an array offset for the clock-output-names property.
2514 */
2515 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
2516 if (index == pv) {
2517 index = count;
2518 break;
2519 }
2520 count++;
2521 }
2522
766e6a4e 2523 if (of_property_read_string_index(clkspec.np, "clock-output-names",
7a0fc1a3 2524 index,
766e6a4e
GL
2525 &clk_name) < 0)
2526 clk_name = clkspec.np->name;
2527
2528 of_node_put(clkspec.np);
2529 return clk_name;
2530}
2531EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
2532
1771b10d
GC
2533struct clock_provider {
2534 of_clk_init_cb_t clk_init_cb;
2535 struct device_node *np;
2536 struct list_head node;
2537};
2538
2539static LIST_HEAD(clk_provider_list);
2540
2541/*
2542 * This function looks for a parent clock. If there is one, then it
2543 * checks that the provider for this parent clock was initialized, in
2544 * this case the parent clock will be ready.
2545 */
2546static int parent_ready(struct device_node *np)
2547{
2548 int i = 0;
2549
2550 while (true) {
2551 struct clk *clk = of_clk_get(np, i);
2552
2553 /* this parent is ready we can check the next one */
2554 if (!IS_ERR(clk)) {
2555 clk_put(clk);
2556 i++;
2557 continue;
2558 }
2559
2560 /* at least one parent is not ready, we exit now */
2561 if (PTR_ERR(clk) == -EPROBE_DEFER)
2562 return 0;
2563
2564 /*
2565 * Here we make assumption that the device tree is
2566 * written correctly. So an error means that there is
2567 * no more parent. As we didn't exit yet, then the
2568 * previous parent are ready. If there is no clock
2569 * parent, no need to wait for them, then we can
2570 * consider their absence as being ready
2571 */
2572 return 1;
2573 }
2574}
2575
766e6a4e
GL
2576/**
2577 * of_clk_init() - Scan and init clock providers from the DT
2578 * @matches: array of compatible values and init functions for providers.
2579 *
1771b10d 2580 * This function scans the device tree for matching clock providers
e5ca8fb4 2581 * and calls their initialization functions. It also does it by trying
1771b10d 2582 * to follow the dependencies.
766e6a4e
GL
2583 */
2584void __init of_clk_init(const struct of_device_id *matches)
2585{
7f7ed584 2586 const struct of_device_id *match;
766e6a4e 2587 struct device_node *np;
1771b10d
GC
2588 struct clock_provider *clk_provider, *next;
2589 bool is_init_done;
2590 bool force = false;
766e6a4e 2591
f2f6c255 2592 if (!matches)
819b4861 2593 matches = &__clk_of_table;
f2f6c255 2594
1771b10d 2595 /* First prepare the list of the clocks providers */
7f7ed584 2596 for_each_matching_node_and_match(np, matches, &match) {
1771b10d
GC
2597 struct clock_provider *parent =
2598 kzalloc(sizeof(struct clock_provider), GFP_KERNEL);
2599
2600 parent->clk_init_cb = match->data;
2601 parent->np = np;
3f6d439f 2602 list_add_tail(&parent->node, &clk_provider_list);
1771b10d
GC
2603 }
2604
2605 while (!list_empty(&clk_provider_list)) {
2606 is_init_done = false;
2607 list_for_each_entry_safe(clk_provider, next,
2608 &clk_provider_list, node) {
2609 if (force || parent_ready(clk_provider->np)) {
2610 clk_provider->clk_init_cb(clk_provider->np);
2611 list_del(&clk_provider->node);
2612 kfree(clk_provider);
2613 is_init_done = true;
2614 }
2615 }
2616
2617 /*
e5ca8fb4 2618 * We didn't manage to initialize any of the
1771b10d
GC
2619 * remaining providers during the last loop, so now we
2620 * initialize all the remaining ones unconditionally
2621 * in case the clock parent was not mandatory
2622 */
2623 if (!is_init_done)
2624 force = true;
2625
766e6a4e
GL
2626 }
2627}
2628#endif
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