blob: 6b44022753cb799962f0fca76937c52394c628b5 [file] [log] [blame]
Mike Turquetteb24764902012-03-15 23:11:19 -07001/*
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>
Grant Likely766e6a42012-04-09 14:50:06 -050019#include <linux/of.h>
Stephen Boyd46c87732012-09-24 13:38:04 -070020#include <linux/device.h>
Prashant Gaikwadf2f6c252013-01-04 12:30:52 +053021#include <linux/init.h>
Mike Turquette533ddeb2013-03-28 13:59:02 -070022#include <linux/sched.h>
Mike Turquetteb24764902012-03-15 23:11:19 -070023
Sylwester Nawrockid6782c22013-08-23 17:03:43 +020024#include "clk.h"
25
Mike Turquetteb24764902012-03-15 23:11:19 -070026static DEFINE_SPINLOCK(enable_lock);
27static DEFINE_MUTEX(prepare_lock);
28
Mike Turquette533ddeb2013-03-28 13:59:02 -070029static struct task_struct *prepare_owner;
30static struct task_struct *enable_owner;
31
32static int prepare_refcnt;
33static int enable_refcnt;
34
Mike Turquetteb24764902012-03-15 23:11:19 -070035static HLIST_HEAD(clk_root_list);
36static HLIST_HEAD(clk_orphan_list);
37static LIST_HEAD(clk_notifier_list);
38
Mike Turquetteeab89f62013-03-28 13:59:01 -070039/*** locking ***/
40static void clk_prepare_lock(void)
41{
Mike Turquette533ddeb2013-03-28 13:59:02 -070042 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;
Mike Turquetteeab89f62013-03-28 13:59:01 -070053}
54
55static void clk_prepare_unlock(void)
56{
Mike Turquette533ddeb2013-03-28 13:59:02 -070057 WARN_ON_ONCE(prepare_owner != current);
58 WARN_ON_ONCE(prepare_refcnt == 0);
59
60 if (--prepare_refcnt)
61 return;
62 prepare_owner = NULL;
Mike Turquetteeab89f62013-03-28 13:59:01 -070063 mutex_unlock(&prepare_lock);
64}
65
66static unsigned long clk_enable_lock(void)
67{
68 unsigned long flags;
Mike Turquette533ddeb2013-03-28 13:59:02 -070069
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;
Mike Turquetteeab89f62013-03-28 13:59:01 -070081 return flags;
82}
83
84static void clk_enable_unlock(unsigned long flags)
85{
Mike Turquette533ddeb2013-03-28 13:59:02 -070086 WARN_ON_ONCE(enable_owner != current);
87 WARN_ON_ONCE(enable_refcnt == 0);
88
89 if (--enable_refcnt)
90 return;
91 enable_owner = NULL;
Mike Turquetteeab89f62013-03-28 13:59:01 -070092 spin_unlock_irqrestore(&enable_lock, flags);
93}
94
Mike Turquetteb24764902012-03-15 23:11:19 -070095/*** debugfs support ***/
96
Mike Turquetteea72dc22013-12-18 21:38:52 -080097#ifdef CONFIG_DEBUG_FS
Mike Turquetteb24764902012-03-15 23:11:19 -070098#include <linux/debugfs.h>
99
100static struct dentry *rootdir;
101static struct dentry *orphandir;
102static int inited = 0;
103
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530104static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level)
105{
106 if (!c)
107 return;
108
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100109 seq_printf(s, "%*s%-*s %-11d %-12d %-10lu %-11lu",
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530110 level * 3 + 1, "",
111 30 - level * 3, c->name,
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100112 c->enable_count, c->prepare_count, clk_get_rate(c),
113 clk_get_accuracy(c));
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530114 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;
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530121
122 if (!c)
123 return;
124
125 clk_summary_show_one(s, c, level);
126
Sasha Levinb67bfe02013-02-27 17:06:00 -0800127 hlist_for_each_entry(child, &c->children, child_node)
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530128 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;
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530134
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100135 seq_printf(s, " clock enable_cnt prepare_cnt rate accuracy\n");
136 seq_printf(s, "---------------------------------------------------------------------------------\n");
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530137
Mike Turquetteeab89f62013-03-28 13:59:01 -0700138 clk_prepare_lock();
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530139
Sasha Levinb67bfe02013-02-27 17:06:00 -0800140 hlist_for_each_entry(c, &clk_root_list, child_node)
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530141 clk_summary_show_subtree(s, c, 0);
142
Sasha Levinb67bfe02013-02-27 17:06:00 -0800143 hlist_for_each_entry(c, &clk_orphan_list, child_node)
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530144 clk_summary_show_subtree(s, c, 0);
145
Mike Turquetteeab89f62013-03-28 13:59:01 -0700146 clk_prepare_unlock();
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530147
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
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530164static 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);
Peter De Schrijver670decd2013-06-05 18:06:35 +0300172 seq_printf(s, "\"rate\": %lu", clk_get_rate(c));
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100173 seq_printf(s, "\"accuracy\": %lu", clk_get_accuracy(c));
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530174}
175
176static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level)
177{
178 struct clk *child;
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530179
180 if (!c)
181 return;
182
183 clk_dump_one(s, c, level);
184
Sasha Levinb67bfe02013-02-27 17:06:00 -0800185 hlist_for_each_entry(child, &c->children, child_node) {
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530186 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;
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530196 bool first_node = true;
197
198 seq_printf(s, "{");
199
Mike Turquetteeab89f62013-03-28 13:59:01 -0700200 clk_prepare_lock();
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530201
Sasha Levinb67bfe02013-02-27 17:06:00 -0800202 hlist_for_each_entry(c, &clk_root_list, child_node) {
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530203 if (!first_node)
204 seq_printf(s, ",");
205 first_node = false;
206 clk_dump_subtree(s, c, 0);
207 }
208
Sasha Levinb67bfe02013-02-27 17:06:00 -0800209 hlist_for_each_entry(c, &clk_orphan_list, child_node) {
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530210 seq_printf(s, ",");
211 clk_dump_subtree(s, c, 0);
212 }
213
Mike Turquetteeab89f62013-03-28 13:59:01 -0700214 clk_prepare_unlock();
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530215
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
Mike Turquetteb24764902012-03-15 23:11:19 -0700233/* 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
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100255 d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry,
256 (u32 *)&clk->accuracy);
257 if (!d)
258 goto err_out;
259
Mike Turquetteb24764902012-03-15 23:11:19 -0700260 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
Alex Elderc646cbf2014-03-21 06:43:56 -0500280 if (clk->ops->debug_init)
281 if (clk->ops->debug_init(clk->hw, clk->dentry))
282 goto err_out;
283
Mike Turquetteb24764902012-03-15 23:11:19 -0700284 ret = 0;
285 goto out;
286
287err_out:
Alex Elderb5f98e62013-11-27 09:39:49 -0600288 debugfs_remove_recursive(clk->dentry);
289 clk->dentry = NULL;
Mike Turquetteb24764902012-03-15 23:11:19 -0700290out:
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;
Mike Turquetteb24764902012-03-15 23:11:19 -0700298 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
Sasha Levinb67bfe02013-02-27 17:06:00 -0800308 hlist_for_each_entry(child, &clk->children, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -0700309 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
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +0200359 /**
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
Mike Turquetteb24764902012-03-15 23:11:19 -0700374/**
Ulf Hanssonb33d2122013-04-02 23:09:37 +0200375 * 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
407/**
Mike Turquetteb24764902012-03-15 23:11:19 -0700408 * 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;
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530422 struct dentry *d;
Mike Turquetteb24764902012-03-15 23:11:19 -0700423
424 rootdir = debugfs_create_dir("clk", NULL);
425
426 if (!rootdir)
427 return -ENOMEM;
428
Prashant Gaikwad1af599d2012-12-26 19:16:22 +0530429 d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, NULL,
430 &clk_summary_fops);
431 if (!d)
432 return -ENOMEM;
433
Prashant Gaikwadbddca892012-12-26 19:16:23 +0530434 d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, NULL,
435 &clk_dump_fops);
436 if (!d)
437 return -ENOMEM;
438
Mike Turquetteb24764902012-03-15 23:11:19 -0700439 orphandir = debugfs_create_dir("orphans", rootdir);
440
441 if (!orphandir)
442 return -ENOMEM;
443
Mike Turquetteeab89f62013-03-28 13:59:01 -0700444 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700445
Sasha Levinb67bfe02013-02-27 17:06:00 -0800446 hlist_for_each_entry(clk, &clk_root_list, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -0700447 clk_debug_create_subtree(clk, rootdir);
448
Sasha Levinb67bfe02013-02-27 17:06:00 -0800449 hlist_for_each_entry(clk, &clk_orphan_list, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -0700450 clk_debug_create_subtree(clk, orphandir);
451
452 inited = 1;
453
Mike Turquetteeab89f62013-03-28 13:59:01 -0700454 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700455
456 return 0;
457}
458late_initcall(clk_debug_init);
459#else
460static inline int clk_debug_register(struct clk *clk) { return 0; }
Ulf Hanssonb33d2122013-04-02 23:09:37 +0200461static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent)
462{
463}
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +0200464static inline void clk_debug_unregister(struct clk *clk)
465{
466}
Mike Turquette70d347e2012-03-26 11:53:47 -0700467#endif
Mike Turquetteb24764902012-03-15 23:11:19 -0700468
Mike Turquetteb24764902012-03-15 23:11:19 -0700469/* caller must hold prepare_lock */
Ulf Hansson1c155b32013-03-12 20:26:03 +0100470static 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
Ulf Hansson3cc82472013-03-12 20:26:04 +0100486 if (__clk_is_prepared(clk)) {
487 if (clk->ops->unprepare_unused)
488 clk->ops->unprepare_unused(clk->hw);
489 else if (clk->ops->unprepare)
Ulf Hansson1c155b32013-03-12 20:26:03 +0100490 clk->ops->unprepare(clk->hw);
Ulf Hansson3cc82472013-03-12 20:26:04 +0100491 }
Ulf Hansson1c155b32013-03-12 20:26:03 +0100492}
493
494/* caller must hold prepare_lock */
Mike Turquetteb24764902012-03-15 23:11:19 -0700495static void clk_disable_unused_subtree(struct clk *clk)
496{
497 struct clk *child;
Mike Turquetteb24764902012-03-15 23:11:19 -0700498 unsigned long flags;
499
500 if (!clk)
501 goto out;
502
Sasha Levinb67bfe02013-02-27 17:06:00 -0800503 hlist_for_each_entry(child, &clk->children, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -0700504 clk_disable_unused_subtree(child);
505
Mike Turquetteeab89f62013-03-28 13:59:01 -0700506 flags = clk_enable_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700507
508 if (clk->enable_count)
509 goto unlock_out;
510
511 if (clk->flags & CLK_IGNORE_UNUSED)
512 goto unlock_out;
513
Mike Turquette7c045a52012-12-04 11:00:35 -0800514 /*
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 }
Mike Turquetteb24764902012-03-15 23:11:19 -0700525
526unlock_out:
Mike Turquetteeab89f62013-03-28 13:59:01 -0700527 clk_enable_unlock(flags);
Mike Turquetteb24764902012-03-15 23:11:19 -0700528
529out:
530 return;
531}
532
Olof Johansson1e435252013-04-27 14:10:18 -0700533static 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
Mike Turquetteb24764902012-03-15 23:11:19 -0700541static int clk_disable_unused(void)
542{
543 struct clk *clk;
Mike Turquetteb24764902012-03-15 23:11:19 -0700544
Olof Johansson1e435252013-04-27 14:10:18 -0700545 if (clk_ignore_unused) {
546 pr_warn("clk: Not disabling unused clocks\n");
547 return 0;
548 }
549
Mike Turquetteeab89f62013-03-28 13:59:01 -0700550 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700551
Sasha Levinb67bfe02013-02-27 17:06:00 -0800552 hlist_for_each_entry(clk, &clk_root_list, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -0700553 clk_disable_unused_subtree(clk);
554
Sasha Levinb67bfe02013-02-27 17:06:00 -0800555 hlist_for_each_entry(clk, &clk_orphan_list, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -0700556 clk_disable_unused_subtree(clk);
557
Ulf Hansson1c155b32013-03-12 20:26:03 +0100558 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
Mike Turquetteeab89f62013-03-28 13:59:01 -0700564 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700565
566 return 0;
567}
Saravana Kannand41d5802013-05-09 11:35:01 -0700568late_initcall_sync(clk_disable_unused);
Mike Turquetteb24764902012-03-15 23:11:19 -0700569
570/*** helper functions ***/
571
Russ Dill65800b22012-11-26 11:20:09 -0800572const char *__clk_get_name(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700573{
574 return !clk ? NULL : clk->name;
575}
Niels de Vos48950842012-12-13 13:12:25 +0100576EXPORT_SYMBOL_GPL(__clk_get_name);
Mike Turquetteb24764902012-03-15 23:11:19 -0700577
Russ Dill65800b22012-11-26 11:20:09 -0800578struct clk_hw *__clk_get_hw(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700579{
580 return !clk ? NULL : clk->hw;
581}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800582EXPORT_SYMBOL_GPL(__clk_get_hw);
Mike Turquetteb24764902012-03-15 23:11:19 -0700583
Russ Dill65800b22012-11-26 11:20:09 -0800584u8 __clk_get_num_parents(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700585{
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700586 return !clk ? 0 : clk->num_parents;
Mike Turquetteb24764902012-03-15 23:11:19 -0700587}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800588EXPORT_SYMBOL_GPL(__clk_get_num_parents);
Mike Turquetteb24764902012-03-15 23:11:19 -0700589
Russ Dill65800b22012-11-26 11:20:09 -0800590struct clk *__clk_get_parent(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700591{
592 return !clk ? NULL : clk->parent;
593}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800594EXPORT_SYMBOL_GPL(__clk_get_parent);
Mike Turquetteb24764902012-03-15 23:11:19 -0700595
James Hogan7ef3dcc2013-07-29 12:24:58 +0100596struct 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}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800608EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
James Hogan7ef3dcc2013-07-29 12:24:58 +0100609
Russ Dill65800b22012-11-26 11:20:09 -0800610unsigned int __clk_get_enable_count(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700611{
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700612 return !clk ? 0 : clk->enable_count;
Mike Turquetteb24764902012-03-15 23:11:19 -0700613}
614
Russ Dill65800b22012-11-26 11:20:09 -0800615unsigned int __clk_get_prepare_count(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700616{
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700617 return !clk ? 0 : clk->prepare_count;
Mike Turquetteb24764902012-03-15 23:11:19 -0700618}
619
620unsigned long __clk_get_rate(struct clk *clk)
621{
622 unsigned long ret;
623
624 if (!clk) {
Rajendra Nayak34e44fe2012-03-26 19:01:48 +0530625 ret = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -0700626 goto out;
627 }
628
629 ret = clk->rate;
630
631 if (clk->flags & CLK_IS_ROOT)
632 goto out;
633
634 if (!clk->parent)
Rajendra Nayak34e44fe2012-03-26 19:01:48 +0530635 ret = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -0700636
637out:
638 return ret;
639}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800640EXPORT_SYMBOL_GPL(__clk_get_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -0700641
Boris BREZILLON5279fc42013-12-21 10:34:47 +0100642unsigned long __clk_get_accuracy(struct clk *clk)
643{
644 if (!clk)
645 return 0;
646
647 return clk->accuracy;
648}
649
Russ Dill65800b22012-11-26 11:20:09 -0800650unsigned long __clk_get_flags(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700651{
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700652 return !clk ? 0 : clk->flags;
Mike Turquetteb24764902012-03-15 23:11:19 -0700653}
Thierry Redingb05c6832013-09-03 09:43:51 +0200654EXPORT_SYMBOL_GPL(__clk_get_flags);
Mike Turquetteb24764902012-03-15 23:11:19 -0700655
Ulf Hansson3d6ee282013-03-12 20:26:02 +0100656bool __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
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700677bool __clk_is_enabled(struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -0700678{
679 int ret;
680
681 if (!clk)
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700682 return false;
Mike Turquetteb24764902012-03-15 23:11:19 -0700683
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:
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700695 return !!ret;
Mike Turquetteb24764902012-03-15 23:11:19 -0700696}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800697EXPORT_SYMBOL_GPL(__clk_is_enabled);
Mike Turquetteb24764902012-03-15 23:11:19 -0700698
699static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk)
700{
701 struct clk *child;
702 struct clk *ret;
Mike Turquetteb24764902012-03-15 23:11:19 -0700703
704 if (!strcmp(clk->name, name))
705 return clk;
706
Sasha Levinb67bfe02013-02-27 17:06:00 -0800707 hlist_for_each_entry(child, &clk->children, child_node) {
Mike Turquetteb24764902012-03-15 23:11:19 -0700708 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;
Mike Turquetteb24764902012-03-15 23:11:19 -0700720
721 if (!name)
722 return NULL;
723
724 /* search the 'proper' clk tree first */
Sasha Levinb67bfe02013-02-27 17:06:00 -0800725 hlist_for_each_entry(root_clk, &clk_root_list, child_node) {
Mike Turquetteb24764902012-03-15 23:11:19 -0700726 ret = __clk_lookup_subtree(name, root_clk);
727 if (ret)
728 return ret;
729 }
730
731 /* if not found, then search the orphan tree */
Sasha Levinb67bfe02013-02-27 17:06:00 -0800732 hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) {
Mike Turquetteb24764902012-03-15 23:11:19 -0700733 ret = __clk_lookup_subtree(name, root_clk);
734 if (ret)
735 return ret;
736 }
737
738 return NULL;
739}
740
James Hogane366fdd2013-07-29 12:25:02 +0100741/*
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}
Stephen Boyd0b7f04b2014-01-17 19:47:17 -0800789EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
James Hogane366fdd2013-07-29 12:25:02 +0100790
Mike Turquetteb24764902012-03-15 23:11:19 -0700791/*** 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
Peter Meerwald24ee1a02013-06-29 15:14:19 +0200814 * @clk: the clk being unprepared
Mike Turquetteb24764902012-03-15 23:11:19 -0700815 *
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{
Mike Turquetteeab89f62013-03-28 13:59:01 -0700825 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700826 __clk_unprepare(clk);
Mike Turquetteeab89f62013-03-28 13:59:01 -0700827 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700828}
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
Mike Turquetteeab89f62013-03-28 13:59:01 -0700873 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700874 ret = __clk_prepare(clk);
Mike Turquetteeab89f62013-03-28 13:59:01 -0700875 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700876
877 return ret;
878}
879EXPORT_SYMBOL_GPL(clk_prepare);
880
881static void __clk_disable(struct clk *clk)
882{
883 if (!clk)
884 return;
885
Fengguang Wue47c6a32012-07-30 14:39:54 -0700886 if (WARN_ON(IS_ERR(clk)))
887 return;
888
Mike Turquetteb24764902012-03-15 23:11:19 -0700889 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
Mike Turquetteeab89f62013-03-28 13:59:01 -0700917 flags = clk_enable_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700918 __clk_disable(clk);
Mike Turquetteeab89f62013-03-28 13:59:01 -0700919 clk_enable_unlock(flags);
Mike Turquetteb24764902012-03-15 23:11:19 -0700920}
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
Mike Turquetteeab89f62013-03-28 13:59:01 -0700970 flags = clk_enable_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -0700971 ret = __clk_enable(clk);
Mike Turquetteeab89f62013-03-28 13:59:01 -0700972 clk_enable_unlock(flags);
Mike Turquetteb24764902012-03-15 23:11:19 -0700973
974 return ret;
975}
976EXPORT_SYMBOL_GPL(clk_enable);
977
978/**
Mike Turquetteb24764902012-03-15 23:11:19 -0700979 * __clk_round_rate - round the given rate for a clk
980 * @clk: round the rate of this clock
Peter Meerwald24ee1a02013-06-29 15:14:19 +0200981 * @rate: the rate which is to be rounded
Mike Turquetteb24764902012-03-15 23:11:19 -0700982 *
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{
Shawn Guo81536e02012-04-12 20:50:17 +0800987 unsigned long parent_rate = 0;
James Hogan71472c02013-07-29 12:25:00 +0100988 struct clk *parent;
Mike Turquetteb24764902012-03-15 23:11:19 -0700989
990 if (!clk)
Stephen Boyd2ac6b1f2012-10-03 23:38:55 -0700991 return 0;
Mike Turquetteb24764902012-03-15 23:11:19 -0700992
James Hogan71472c02013-07-29 12:25:00 +0100993 parent = clk->parent;
994 if (parent)
995 parent_rate = parent->rate;
Mike Turquetteb24764902012-03-15 23:11:19 -0700996
James Hogan71472c02013-07-29 12:25:00 +0100997 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;
Mike Turquetteb24764902012-03-15 23:11:19 -07001006}
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
Mike Turquetteeab89f62013-03-28 13:59:01 -07001021 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001022 ret = __clk_round_rate(clk, rate);
Mike Turquetteeab89f62013-03-28 13:59:01 -07001023 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001024
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
1065/**
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001066 * __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
1118/**
Mike Turquetteb24764902012-03-15 23:11:19 -07001119 * __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
Peter Meerwald24ee1a02013-06-29 15:14:19 +02001125 * it is assumed that the clock will take on the rate of its parent.
Mike Turquetteb24764902012-03-15 23:11:19 -07001126 *
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;
Mike Turquetteb24764902012-03-15 23:11:19 -07001136 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
Sasha Levinb67bfe02013-02-27 17:06:00 -08001155 hlist_for_each_entry(child, &clk->children, child_node)
Mike Turquetteb24764902012-03-15 23:11:19 -07001156 __clk_recalc_rates(child, msg);
1157}
1158
1159/**
Ulf Hanssona093bde2012-08-31 14:21:28 +02001160 * 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
Mike Turquetteeab89f62013-03-28 13:59:01 -07001171 clk_prepare_lock();
Ulf Hanssona093bde2012-08-31 14:21:28 +02001172
1173 if (clk && (clk->flags & CLK_GET_RATE_NOCACHE))
1174 __clk_recalc_rates(clk, 0);
1175
1176 rate = __clk_get_rate(clk);
Mike Turquetteeab89f62013-03-28 13:59:01 -07001177 clk_prepare_unlock();
Ulf Hanssona093bde2012-08-31 14:21:28 +02001178
1179 return rate;
1180}
1181EXPORT_SYMBOL_GPL(clk_get_rate);
1182
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001183static int clk_fetch_parent_index(struct clk *clk, struct clk *parent)
James Hogan4935b222013-07-29 12:24:59 +01001184{
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001185 int i;
James Hogan4935b222013-07-29 12:24:59 +01001186
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001187 if (!clk->parents) {
Tomasz Figa96a7ed92013-09-29 02:37:15 +02001188 clk->parents = kcalloc(clk->num_parents,
1189 sizeof(struct clk *), GFP_KERNEL);
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001190 if (!clk->parents)
1191 return -ENOMEM;
1192 }
James Hogan4935b222013-07-29 12:24:59 +01001193
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++) {
Tomasz Figada0f0b22013-09-29 02:37:16 +02001200 if (clk->parents[i] == parent)
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001201 return i;
Tomasz Figada0f0b22013-09-29 02:37:16 +02001202
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);
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001208 return i;
James Hogan4935b222013-07-29 12:24:59 +01001209 }
1210 }
1211
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001212 return -EINVAL;
James Hogan4935b222013-07-29 12:24:59 +01001213}
1214
1215static void clk_reparent(struct clk *clk, struct clk *new_parent)
1216{
1217 hlist_del(&clk->child_node);
1218
James Hogan903efc52013-08-29 12:10:51 +01001219 if (new_parent) {
1220 /* avoid duplicate POST_RATE_CHANGE notifications */
1221 if (new_parent->new_child == clk)
1222 new_parent->new_child = NULL;
1223
James Hogan4935b222013-07-29 12:24:59 +01001224 hlist_add_head(&clk->child_node, &new_parent->children);
James Hogan903efc52013-08-29 12:10:51 +01001225 } else {
James Hogan4935b222013-07-29 12:24:59 +01001226 hlist_add_head(&clk->child_node, &clk_orphan_list);
James Hogan903efc52013-08-29 12:10:51 +01001227 }
James Hogan4935b222013-07-29 12:24:59 +01001228
1229 clk->parent = new_parent;
1230}
1231
Stephen Boyd3fa22522014-01-15 10:47:22 -08001232static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent)
James Hogan4935b222013-07-29 12:24:59 +01001233{
1234 unsigned long flags;
James Hogan4935b222013-07-29 12:24:59 +01001235 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
Stephen Boyd3fa22522014-01-15 10:47:22 -08001265 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
James Hogan4935b222013-07-29 12:24:59 +01001293 /* 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
Stephen Boyd3fa22522014-01-15 10:47:22 -08001310 __clk_set_parent_after(clk, parent, old_parent);
James Hogan4935b222013-07-29 12:24:59 +01001311
James Hogan4935b222013-07-29 12:24:59 +01001312 return 0;
1313}
1314
Ulf Hanssona093bde2012-08-31 14:21:28 +02001315/**
Mike Turquetteb24764902012-03-15 23:11:19 -07001316 * __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
Peter Meerwald24ee1a02013-06-29 15:14:19 +02001327 * take on the rate of its parent.
Mike Turquetteb24764902012-03-15 23:11:19 -07001328 *
1329 * Caller must hold prepare_lock.
1330 */
1331static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate)
1332{
Mike Turquetteb24764902012-03-15 23:11:19 -07001333 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
Soren Brinkmannfb72a052013-04-03 12:17:12 -07001342 /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
Mike Turquetteb24764902012-03-15 23:11:19 -07001343 if (clk->notifier_count)
1344 ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate);
1345
Mike Turquette86bcfa22014-02-24 16:08:41 -08001346 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);
Mike Turquetteb24764902012-03-15 23:11:19 -07001349 goto out;
Mike Turquette86bcfa22014-02-24 16:08:41 -08001350 }
Mike Turquetteb24764902012-03-15 23:11:19 -07001351
Sasha Levinb67bfe02013-02-27 17:06:00 -08001352 hlist_for_each_entry(child, &clk->children, child_node) {
Mike Turquetteb24764902012-03-15 23:11:19 -07001353 ret = __clk_speculate_rates(child, new_rate);
Soren Brinkmannfb72a052013-04-03 12:17:12 -07001354 if (ret & NOTIFY_STOP_MASK)
Mike Turquetteb24764902012-03-15 23:11:19 -07001355 break;
1356 }
1357
1358out:
1359 return ret;
1360}
1361
James Hogan71472c02013-07-29 12:25:00 +01001362static void clk_calc_subtree(struct clk *clk, unsigned long new_rate,
1363 struct clk *new_parent, u8 p_index)
Mike Turquetteb24764902012-03-15 23:11:19 -07001364{
1365 struct clk *child;
Mike Turquetteb24764902012-03-15 23:11:19 -07001366
1367 clk->new_rate = new_rate;
James Hogan71472c02013-07-29 12:25:00 +01001368 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;
Mike Turquetteb24764902012-03-15 23:11:19 -07001374
Sasha Levinb67bfe02013-02-27 17:06:00 -08001375 hlist_for_each_entry(child, &clk->children, child_node) {
Mike Turquetteb24764902012-03-15 23:11:19 -07001376 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;
James Hogan71472c02013-07-29 12:25:00 +01001380 clk_calc_subtree(child, child->new_rate, NULL, 0);
Mike Turquetteb24764902012-03-15 23:11:19 -07001381 }
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;
James Hogan71472c02013-07-29 12:25:00 +01001391 struct clk *old_parent, *parent;
Shawn Guo81536e02012-04-12 20:50:17 +08001392 unsigned long best_parent_rate = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -07001393 unsigned long new_rate;
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001394 int p_index = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -07001395
Mike Turquette7452b212012-03-26 14:45:36 -07001396 /* sanity */
1397 if (IS_ERR_OR_NULL(clk))
1398 return NULL;
1399
Mike Turquette63f5c3b2012-05-02 16:23:43 -07001400 /* save parent rate, if it exists */
James Hogan71472c02013-07-29 12:25:00 +01001401 parent = old_parent = clk->parent;
1402 if (parent)
1403 best_parent_rate = parent->rate;
Mike Turquette63f5c3b2012-05-02 16:23:43 -07001404
James Hogan71472c02013-07-29 12:25:00 +01001405 /* 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;
Mike Turquette63f5c3b2012-05-02 16:23:43 -07001421 goto out;
Mike Turquette7452b212012-03-26 14:45:36 -07001422 }
1423
James Hogan71472c02013-07-29 12:25:00 +01001424 /* 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);
Mike Turquetteb24764902012-03-15 23:11:19 -07001429 return NULL;
1430 }
1431
James Hogan71472c02013-07-29 12:25:00 +01001432 /* try finding the new parent index */
1433 if (parent) {
1434 p_index = clk_fetch_parent_index(clk, parent);
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001435 if (p_index < 0) {
James Hogan71472c02013-07-29 12:25:00 +01001436 pr_debug("%s: clk %s can not be parent of clk %s\n",
1437 __func__, parent->name, clk->name);
1438 return NULL;
1439 }
Mike Turquetteb24764902012-03-15 23:11:19 -07001440 }
1441
James Hogan71472c02013-07-29 12:25:00 +01001442 if ((clk->flags & CLK_SET_RATE_PARENT) && parent &&
1443 best_parent_rate != parent->rate)
1444 top = clk_calc_new_rates(parent, best_parent_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001445
1446out:
James Hogan71472c02013-07-29 12:25:00 +01001447 clk_calc_subtree(clk, new_rate, parent, p_index);
Mike Turquetteb24764902012-03-15 23:11:19 -07001448
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{
James Hogan71472c02013-07-29 12:25:00 +01001459 struct clk *child, *tmp_clk, *fail_clk = NULL;
Mike Turquetteb24764902012-03-15 23:11:19 -07001460 int ret = NOTIFY_DONE;
1461
1462 if (clk->rate == clk->new_rate)
Sachin Kamat5fda6852013-03-13 15:17:49 +05301463 return NULL;
Mike Turquetteb24764902012-03-15 23:11:19 -07001464
1465 if (clk->notifier_count) {
1466 ret = __clk_notify(clk, event, clk->rate, clk->new_rate);
Soren Brinkmannfb72a052013-04-03 12:17:12 -07001467 if (ret & NOTIFY_STOP_MASK)
Mike Turquetteb24764902012-03-15 23:11:19 -07001468 fail_clk = clk;
1469 }
1470
Sasha Levinb67bfe02013-02-27 17:06:00 -08001471 hlist_for_each_entry(child, &clk->children, child_node) {
James Hogan71472c02013-07-29 12:25:00 +01001472 /* 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;
Mike Turquetteb24764902012-03-15 23:11:19 -07001485 }
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;
Pawel Mollbf47b4f2012-06-08 14:04:06 +01001498 unsigned long best_parent_rate = 0;
Stephen Boyd3fa22522014-01-15 10:47:22 -08001499 bool skip_set_rate = false;
1500 struct clk *old_parent;
Mike Turquetteb24764902012-03-15 23:11:19 -07001501
1502 old_rate = clk->rate;
1503
Stephen Boyd3fa22522014-01-15 10:47:22 -08001504 if (clk->new_parent)
1505 best_parent_rate = clk->new_parent->rate;
1506 else if (clk->parent)
Pawel Mollbf47b4f2012-06-08 14:04:06 +01001507 best_parent_rate = clk->parent->rate;
1508
Stephen Boyd3fa22522014-01-15 10:47:22 -08001509 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)
Pawel Mollbf47b4f2012-06-08 14:04:06 +01001525 clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001526
1527 if (clk->ops->recalc_rate)
Pawel Mollbf47b4f2012-06-08 14:04:06 +01001528 clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001529 else
Pawel Mollbf47b4f2012-06-08 14:04:06 +01001530 clk->rate = best_parent_rate;
Mike Turquetteb24764902012-03-15 23:11:19 -07001531
1532 if (clk->notifier_count && old_rate != clk->rate)
1533 __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
1534
James Hogan71472c02013-07-29 12:25:00 +01001535 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;
Mike Turquetteb24764902012-03-15 23:11:19 -07001539 clk_change_rate(child);
James Hogan71472c02013-07-29 12:25:00 +01001540 }
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);
Mike Turquetteb24764902012-03-15 23:11:19 -07001545}
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 *
Mike Turquette5654dc92012-03-26 11:51:34 -07001552 * In the simplest case clk_set_rate will only adjust the rate of clk.
Mike Turquetteb24764902012-03-15 23:11:19 -07001553 *
Mike Turquette5654dc92012-03-26 11:51:34 -07001554 * 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
Peter Meerwald24ee1a02013-06-29 15:14:19 +02001559 * up to clk's parent and set its rate. Upward propagation will continue
Mike Turquette5654dc92012-03-26 11:51:34 -07001560 * 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.
Mike Turquetteb24764902012-03-15 23:11:19 -07001562 *
Mike Turquette5654dc92012-03-26 11:51:34 -07001563 * Rate changes are accomplished via tree traversal that also recalculates the
1564 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
Mike Turquetteb24764902012-03-15 23:11:19 -07001565 *
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
Mike Turquette89ac8d72013-08-21 23:58:09 -07001573 if (!clk)
1574 return 0;
1575
Mike Turquetteb24764902012-03-15 23:11:19 -07001576 /* prevent racing with updates to the clock topology */
Mike Turquetteeab89f62013-03-28 13:59:01 -07001577 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001578
1579 /* bail early if nothing to do */
Peter De Schrijver34e452a2013-06-05 18:06:36 +03001580 if (rate == clk_get_rate(clk))
Mike Turquetteb24764902012-03-15 23:11:19 -07001581 goto out;
1582
Saravana Kannan7e0fa1b2012-05-15 13:43:42 -07001583 if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) {
Viresh Kumar0e1c0302012-04-11 16:03:42 +05301584 ret = -EBUSY;
1585 goto out;
1586 }
1587
Mike Turquetteb24764902012-03-15 23:11:19 -07001588 /* 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) {
Sascha Hauerf7363862014-01-16 16:12:55 +01001598 pr_debug("%s: failed to set %s rate\n", __func__,
Mike Turquetteb24764902012-03-15 23:11:19 -07001599 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
Mike Turquetteb24764902012-03-15 23:11:19 -07001608out:
Mike Turquetteeab89f62013-03-28 13:59:01 -07001609 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001610
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
Mike Turquetteeab89f62013-03-28 13:59:01 -07001625 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001626 parent = __clk_get_parent(clk);
Mike Turquetteeab89f62013-03-28 13:59:01 -07001627 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001628
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 =
Tomasz Figa96a7ed92013-09-29 02:37:15 +02001676 kcalloc(clk->num_parents, sizeof(struct clk *),
Mike Turquetteb24764902012-03-15 23:11:19 -07001677 GFP_KERNEL);
1678
James Hogan7ef3dcc2013-07-29 12:24:58 +01001679 ret = clk_get_parent_by_index(clk, index);
Mike Turquetteb24764902012-03-15 23:11:19 -07001680
1681out:
1682 return ret;
1683}
1684
Ulf Hanssonb33d2122013-04-02 23:09:37 +02001685void __clk_reparent(struct clk *clk, struct clk *new_parent)
1686{
1687 clk_reparent(clk, new_parent);
1688 clk_debug_reparent(clk, new_parent);
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001689 __clk_recalc_accuracies(clk);
Mike Turquetteb24764902012-03-15 23:11:19 -07001690 __clk_recalc_rates(clk, POST_RATE_CHANGE);
1691}
1692
Mike Turquetteb24764902012-03-15 23:11:19 -07001693/**
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 *
Saravana Kannanf8aa0bd2013-05-15 21:07:24 -07001698 * 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.
Mike Turquetteb24764902012-03-15 23:11:19 -07001709 */
1710int clk_set_parent(struct clk *clk, struct clk *parent)
1711{
1712 int ret = 0;
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001713 int p_index = 0;
Ulf Hansson031dcc92013-04-02 23:09:38 +02001714 unsigned long p_rate = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -07001715
Mike Turquette89ac8d72013-08-21 23:58:09 -07001716 if (!clk)
1717 return 0;
1718
1719 if (!clk->ops)
Mike Turquetteb24764902012-03-15 23:11:19 -07001720 return -EINVAL;
1721
Ulf Hansson031dcc92013-04-02 23:09:38 +02001722 /* verify ops for for multi-parent clks */
1723 if ((clk->num_parents > 1) && (!clk->ops->set_parent))
Mike Turquetteb24764902012-03-15 23:11:19 -07001724 return -ENOSYS;
1725
1726 /* prevent racing with updates to the clock topology */
Mike Turquetteeab89f62013-03-28 13:59:01 -07001727 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001728
1729 if (clk->parent == parent)
1730 goto out;
1731
Ulf Hansson031dcc92013-04-02 23:09:38 +02001732 /* check that we are allowed to re-parent if the clock is in use */
1733 if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
1734 ret = -EBUSY;
1735 goto out;
1736 }
1737
1738 /* try finding the new parent index */
1739 if (parent) {
1740 p_index = clk_fetch_parent_index(clk, parent);
1741 p_rate = parent->rate;
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001742 if (p_index < 0) {
Ulf Hansson031dcc92013-04-02 23:09:38 +02001743 pr_debug("%s: clk %s can not be parent of clk %s\n",
1744 __func__, parent->name, clk->name);
Tomasz Figaf1c8b2e2013-09-29 02:37:14 +02001745 ret = p_index;
Ulf Hansson031dcc92013-04-02 23:09:38 +02001746 goto out;
1747 }
1748 }
1749
Mike Turquetteb24764902012-03-15 23:11:19 -07001750 /* propagate PRE_RATE_CHANGE notifications */
Soren Brinkmannf3aab5d2013-04-16 10:06:50 -07001751 ret = __clk_speculate_rates(clk, p_rate);
Mike Turquetteb24764902012-03-15 23:11:19 -07001752
1753 /* abort if a driver objects */
Soren Brinkmannfb72a052013-04-03 12:17:12 -07001754 if (ret & NOTIFY_STOP_MASK)
Mike Turquetteb24764902012-03-15 23:11:19 -07001755 goto out;
1756
Ulf Hansson031dcc92013-04-02 23:09:38 +02001757 /* do the re-parent */
1758 ret = __clk_set_parent(clk, parent, p_index);
Mike Turquetteb24764902012-03-15 23:11:19 -07001759
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001760 /* propagate rate an accuracy recalculation accordingly */
1761 if (ret) {
Mike Turquetteb24764902012-03-15 23:11:19 -07001762 __clk_recalc_rates(clk, ABORT_RATE_CHANGE);
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001763 } else {
Ulf Hanssona68de8e2013-04-02 23:09:39 +02001764 __clk_recalc_rates(clk, POST_RATE_CHANGE);
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001765 __clk_recalc_accuracies(clk);
1766 }
Mike Turquetteb24764902012-03-15 23:11:19 -07001767
1768out:
Mike Turquetteeab89f62013-03-28 13:59:01 -07001769 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001770
1771 return ret;
1772}
1773EXPORT_SYMBOL_GPL(clk_set_parent);
1774
1775/**
1776 * __clk_init - initialize the data structures in a struct clk
1777 * @dev: device initializing this clk, placeholder for now
1778 * @clk: clk being initialized
1779 *
1780 * Initializes the lists in struct clk, queries the hardware for the
1781 * parent and rate and sets them both.
Mike Turquetteb24764902012-03-15 23:11:19 -07001782 */
Mike Turquetted1302a32012-03-29 14:30:40 -07001783int __clk_init(struct device *dev, struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -07001784{
Mike Turquetted1302a32012-03-29 14:30:40 -07001785 int i, ret = 0;
Mike Turquetteb24764902012-03-15 23:11:19 -07001786 struct clk *orphan;
Sasha Levinb67bfe02013-02-27 17:06:00 -08001787 struct hlist_node *tmp2;
Mike Turquetteb24764902012-03-15 23:11:19 -07001788
1789 if (!clk)
Mike Turquetted1302a32012-03-29 14:30:40 -07001790 return -EINVAL;
Mike Turquetteb24764902012-03-15 23:11:19 -07001791
Mike Turquetteeab89f62013-03-28 13:59:01 -07001792 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001793
1794 /* check to see if a clock with this name is already registered */
Mike Turquetted1302a32012-03-29 14:30:40 -07001795 if (__clk_lookup(clk->name)) {
1796 pr_debug("%s: clk %s already initialized\n",
1797 __func__, clk->name);
1798 ret = -EEXIST;
Mike Turquetteb24764902012-03-15 23:11:19 -07001799 goto out;
Mike Turquetted1302a32012-03-29 14:30:40 -07001800 }
Mike Turquetteb24764902012-03-15 23:11:19 -07001801
Mike Turquetted4d7e3d2012-03-26 16:15:52 -07001802 /* check that clk_ops are sane. See Documentation/clk.txt */
1803 if (clk->ops->set_rate &&
James Hogan71472c02013-07-29 12:25:00 +01001804 !((clk->ops->round_rate || clk->ops->determine_rate) &&
1805 clk->ops->recalc_rate)) {
1806 pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
Mike Turquetted4d7e3d2012-03-26 16:15:52 -07001807 __func__, clk->name);
Mike Turquetted1302a32012-03-29 14:30:40 -07001808 ret = -EINVAL;
Mike Turquetted4d7e3d2012-03-26 16:15:52 -07001809 goto out;
1810 }
1811
1812 if (clk->ops->set_parent && !clk->ops->get_parent) {
1813 pr_warning("%s: %s must implement .get_parent & .set_parent\n",
1814 __func__, clk->name);
Mike Turquetted1302a32012-03-29 14:30:40 -07001815 ret = -EINVAL;
Mike Turquetted4d7e3d2012-03-26 16:15:52 -07001816 goto out;
1817 }
1818
Stephen Boyd3fa22522014-01-15 10:47:22 -08001819 if (clk->ops->set_rate_and_parent &&
1820 !(clk->ops->set_parent && clk->ops->set_rate)) {
1821 pr_warn("%s: %s must implement .set_parent & .set_rate\n",
1822 __func__, clk->name);
1823 ret = -EINVAL;
1824 goto out;
1825 }
1826
Mike Turquetteb24764902012-03-15 23:11:19 -07001827 /* throw a WARN if any entries in parent_names are NULL */
1828 for (i = 0; i < clk->num_parents; i++)
1829 WARN(!clk->parent_names[i],
1830 "%s: invalid NULL in %s's .parent_names\n",
1831 __func__, clk->name);
1832
1833 /*
1834 * Allocate an array of struct clk *'s to avoid unnecessary string
1835 * look-ups of clk's possible parents. This can fail for clocks passed
1836 * in to clk_init during early boot; thus any access to clk->parents[]
1837 * must always check for a NULL pointer and try to populate it if
1838 * necessary.
1839 *
1840 * If clk->parents is not NULL we skip this entire block. This allows
1841 * for clock drivers to statically initialize clk->parents.
1842 */
Rajendra Nayak9ca1c5a2012-06-06 14:41:30 +05301843 if (clk->num_parents > 1 && !clk->parents) {
Tomasz Figa96a7ed92013-09-29 02:37:15 +02001844 clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *),
1845 GFP_KERNEL);
Mike Turquetteb24764902012-03-15 23:11:19 -07001846 /*
1847 * __clk_lookup returns NULL for parents that have not been
1848 * clk_init'd; thus any access to clk->parents[] must check
1849 * for a NULL pointer. We can always perform lazy lookups for
1850 * missing parents later on.
1851 */
1852 if (clk->parents)
1853 for (i = 0; i < clk->num_parents; i++)
1854 clk->parents[i] =
1855 __clk_lookup(clk->parent_names[i]);
1856 }
1857
1858 clk->parent = __clk_init_parent(clk);
1859
1860 /*
1861 * Populate clk->parent if parent has already been __clk_init'd. If
1862 * parent has not yet been __clk_init'd then place clk in the orphan
1863 * list. If clk has set the CLK_IS_ROOT flag then place it in the root
1864 * clk list.
1865 *
1866 * Every time a new clk is clk_init'd then we walk the list of orphan
1867 * clocks and re-parent any that are children of the clock currently
1868 * being clk_init'd.
1869 */
1870 if (clk->parent)
1871 hlist_add_head(&clk->child_node,
1872 &clk->parent->children);
1873 else if (clk->flags & CLK_IS_ROOT)
1874 hlist_add_head(&clk->child_node, &clk_root_list);
1875 else
1876 hlist_add_head(&clk->child_node, &clk_orphan_list);
1877
1878 /*
Boris BREZILLON5279fc42013-12-21 10:34:47 +01001879 * Set clk's accuracy. The preferred method is to use
1880 * .recalc_accuracy. For simple clocks and lazy developers the default
1881 * fallback is to use the parent's accuracy. If a clock doesn't have a
1882 * parent (or is orphaned) then accuracy is set to zero (perfect
1883 * clock).
1884 */
1885 if (clk->ops->recalc_accuracy)
1886 clk->accuracy = clk->ops->recalc_accuracy(clk->hw,
1887 __clk_get_accuracy(clk->parent));
1888 else if (clk->parent)
1889 clk->accuracy = clk->parent->accuracy;
1890 else
1891 clk->accuracy = 0;
1892
1893 /*
Mike Turquetteb24764902012-03-15 23:11:19 -07001894 * Set clk's rate. The preferred method is to use .recalc_rate. For
1895 * simple clocks and lazy developers the default fallback is to use the
1896 * parent's rate. If a clock doesn't have a parent (or is orphaned)
1897 * then rate is set to zero.
1898 */
1899 if (clk->ops->recalc_rate)
1900 clk->rate = clk->ops->recalc_rate(clk->hw,
1901 __clk_get_rate(clk->parent));
1902 else if (clk->parent)
1903 clk->rate = clk->parent->rate;
1904 else
1905 clk->rate = 0;
1906
Stephen Boyd3a5aec22013-10-16 00:40:03 -07001907 clk_debug_register(clk);
Mike Turquetteb24764902012-03-15 23:11:19 -07001908 /*
1909 * walk the list of orphan clocks and reparent any that are children of
1910 * this clock
1911 */
Sasha Levinb67bfe02013-02-27 17:06:00 -08001912 hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
Alex Elder12d298862013-09-05 08:33:24 -05001913 if (orphan->num_parents && orphan->ops->get_parent) {
Martin Fuzzey1f61e5f2012-11-22 20:15:05 +01001914 i = orphan->ops->get_parent(orphan->hw);
1915 if (!strcmp(clk->name, orphan->parent_names[i]))
1916 __clk_reparent(orphan, clk);
1917 continue;
1918 }
1919
Mike Turquetteb24764902012-03-15 23:11:19 -07001920 for (i = 0; i < orphan->num_parents; i++)
1921 if (!strcmp(clk->name, orphan->parent_names[i])) {
1922 __clk_reparent(orphan, clk);
1923 break;
1924 }
Martin Fuzzey1f61e5f2012-11-22 20:15:05 +01001925 }
Mike Turquetteb24764902012-03-15 23:11:19 -07001926
1927 /*
1928 * optional platform-specific magic
1929 *
1930 * The .init callback is not used by any of the basic clock types, but
1931 * exists for weird hardware that must perform initialization magic.
1932 * Please consider other ways of solving initialization problems before
Peter Meerwald24ee1a02013-06-29 15:14:19 +02001933 * using this callback, as its use is discouraged.
Mike Turquetteb24764902012-03-15 23:11:19 -07001934 */
1935 if (clk->ops->init)
1936 clk->ops->init(clk->hw);
1937
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02001938 kref_init(&clk->ref);
Mike Turquetteb24764902012-03-15 23:11:19 -07001939out:
Mike Turquetteeab89f62013-03-28 13:59:01 -07001940 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07001941
Mike Turquetted1302a32012-03-29 14:30:40 -07001942 return ret;
Mike Turquetteb24764902012-03-15 23:11:19 -07001943}
1944
1945/**
Saravana Kannan0197b3e2012-04-25 22:58:56 -07001946 * __clk_register - register a clock and return a cookie.
1947 *
1948 * Same as clk_register, except that the .clk field inside hw shall point to a
1949 * preallocated (generally statically allocated) struct clk. None of the fields
1950 * of the struct clk need to be initialized.
1951 *
1952 * The data pointed to by .init and .clk field shall NOT be marked as init
1953 * data.
1954 *
1955 * __clk_register is only exposed via clk-private.h and is intended for use with
1956 * very large numbers of clocks that need to be statically initialized. It is
1957 * a layering violation to include clk-private.h from any code which implements
1958 * a clock's .ops; as such any statically initialized clock data MUST be in a
Peter Meerwald24ee1a02013-06-29 15:14:19 +02001959 * separate C file from the logic that implements its operations. Returns 0
Saravana Kannan0197b3e2012-04-25 22:58:56 -07001960 * on success, otherwise an error code.
1961 */
1962struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
1963{
1964 int ret;
1965 struct clk *clk;
1966
1967 clk = hw->clk;
1968 clk->name = hw->init->name;
1969 clk->ops = hw->init->ops;
1970 clk->hw = hw;
1971 clk->flags = hw->init->flags;
1972 clk->parent_names = hw->init->parent_names;
1973 clk->num_parents = hw->init->num_parents;
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02001974 if (dev && dev->driver)
1975 clk->owner = dev->driver->owner;
1976 else
1977 clk->owner = NULL;
Saravana Kannan0197b3e2012-04-25 22:58:56 -07001978
1979 ret = __clk_init(dev, clk);
1980 if (ret)
1981 return ERR_PTR(ret);
1982
1983 return clk;
1984}
1985EXPORT_SYMBOL_GPL(__clk_register);
1986
Stephen Boyd46c87732012-09-24 13:38:04 -07001987static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk)
Mike Turquetteb24764902012-03-15 23:11:19 -07001988{
Mike Turquetted1302a32012-03-29 14:30:40 -07001989 int i, ret;
Mike Turquetteb24764902012-03-15 23:11:19 -07001990
Saravana Kannan0197b3e2012-04-25 22:58:56 -07001991 clk->name = kstrdup(hw->init->name, GFP_KERNEL);
1992 if (!clk->name) {
1993 pr_err("%s: could not allocate clk->name\n", __func__);
1994 ret = -ENOMEM;
1995 goto fail_name;
1996 }
1997 clk->ops = hw->init->ops;
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02001998 if (dev && dev->driver)
1999 clk->owner = dev->driver->owner;
Mike Turquetteb24764902012-03-15 23:11:19 -07002000 clk->hw = hw;
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002001 clk->flags = hw->init->flags;
2002 clk->num_parents = hw->init->num_parents;
Mike Turquetteb24764902012-03-15 23:11:19 -07002003 hw->clk = clk;
2004
Mike Turquetted1302a32012-03-29 14:30:40 -07002005 /* allocate local copy in case parent_names is __initdata */
Tomasz Figa96a7ed92013-09-29 02:37:15 +02002006 clk->parent_names = kcalloc(clk->num_parents, sizeof(char *),
2007 GFP_KERNEL);
Mike Turquetteb24764902012-03-15 23:11:19 -07002008
Mike Turquetted1302a32012-03-29 14:30:40 -07002009 if (!clk->parent_names) {
2010 pr_err("%s: could not allocate clk->parent_names\n", __func__);
2011 ret = -ENOMEM;
2012 goto fail_parent_names;
2013 }
2014
2015
2016 /* copy each string name in case parent_names is __initdata */
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002017 for (i = 0; i < clk->num_parents; i++) {
2018 clk->parent_names[i] = kstrdup(hw->init->parent_names[i],
2019 GFP_KERNEL);
Mike Turquetted1302a32012-03-29 14:30:40 -07002020 if (!clk->parent_names[i]) {
2021 pr_err("%s: could not copy parent_names\n", __func__);
2022 ret = -ENOMEM;
2023 goto fail_parent_names_copy;
2024 }
2025 }
2026
2027 ret = __clk_init(dev, clk);
2028 if (!ret)
Stephen Boyd46c87732012-09-24 13:38:04 -07002029 return 0;
Mike Turquetted1302a32012-03-29 14:30:40 -07002030
2031fail_parent_names_copy:
2032 while (--i >= 0)
2033 kfree(clk->parent_names[i]);
2034 kfree(clk->parent_names);
2035fail_parent_names:
Saravana Kannan0197b3e2012-04-25 22:58:56 -07002036 kfree(clk->name);
2037fail_name:
Stephen Boyd46c87732012-09-24 13:38:04 -07002038 return ret;
2039}
2040
2041/**
2042 * clk_register - allocate a new clock, register it and return an opaque cookie
2043 * @dev: device that is registering this clock
2044 * @hw: link to hardware-specific clock data
2045 *
2046 * clk_register is the primary interface for populating the clock tree with new
2047 * clock nodes. It returns a pointer to the newly allocated struct clk which
2048 * cannot be dereferenced by driver code but may be used in conjuction with the
2049 * rest of the clock API. In the event of an error clk_register will return an
2050 * error code; drivers must test for an error code after calling clk_register.
2051 */
2052struct clk *clk_register(struct device *dev, struct clk_hw *hw)
2053{
2054 int ret;
2055 struct clk *clk;
2056
2057 clk = kzalloc(sizeof(*clk), GFP_KERNEL);
2058 if (!clk) {
2059 pr_err("%s: could not allocate clk\n", __func__);
2060 ret = -ENOMEM;
2061 goto fail_out;
2062 }
2063
2064 ret = _clk_register(dev, hw, clk);
2065 if (!ret)
2066 return clk;
2067
Mike Turquetted1302a32012-03-29 14:30:40 -07002068 kfree(clk);
2069fail_out:
2070 return ERR_PTR(ret);
Mike Turquetteb24764902012-03-15 23:11:19 -07002071}
2072EXPORT_SYMBOL_GPL(clk_register);
2073
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002074/*
2075 * Free memory allocated for a clock.
2076 * Caller must hold prepare_lock.
2077 */
2078static void __clk_release(struct kref *ref)
2079{
2080 struct clk *clk = container_of(ref, struct clk, ref);
2081 int i = clk->num_parents;
2082
2083 kfree(clk->parents);
2084 while (--i >= 0)
2085 kfree(clk->parent_names[i]);
2086
2087 kfree(clk->parent_names);
2088 kfree(clk->name);
2089 kfree(clk);
2090}
2091
2092/*
2093 * Empty clk_ops for unregistered clocks. These are used temporarily
2094 * after clk_unregister() was called on a clock and until last clock
2095 * consumer calls clk_put() and the struct clk object is freed.
2096 */
2097static int clk_nodrv_prepare_enable(struct clk_hw *hw)
2098{
2099 return -ENXIO;
2100}
2101
2102static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
2103{
2104 WARN_ON_ONCE(1);
2105}
2106
2107static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
2108 unsigned long parent_rate)
2109{
2110 return -ENXIO;
2111}
2112
2113static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
2114{
2115 return -ENXIO;
2116}
2117
2118static const struct clk_ops clk_nodrv_ops = {
2119 .enable = clk_nodrv_prepare_enable,
2120 .disable = clk_nodrv_disable_unprepare,
2121 .prepare = clk_nodrv_prepare_enable,
2122 .unprepare = clk_nodrv_disable_unprepare,
2123 .set_rate = clk_nodrv_set_rate,
2124 .set_parent = clk_nodrv_set_parent,
2125};
2126
Mark Brown1df5c932012-04-18 09:07:12 +01002127/**
2128 * clk_unregister - unregister a currently registered clock
2129 * @clk: clock to unregister
Mark Brown1df5c932012-04-18 09:07:12 +01002130 */
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002131void clk_unregister(struct clk *clk)
2132{
2133 unsigned long flags;
2134
2135 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
2136 return;
2137
2138 clk_prepare_lock();
2139
2140 if (clk->ops == &clk_nodrv_ops) {
2141 pr_err("%s: unregistered clock: %s\n", __func__, clk->name);
2142 goto out;
2143 }
2144 /*
2145 * Assign empty clock ops for consumers that might still hold
2146 * a reference to this clock.
2147 */
2148 flags = clk_enable_lock();
2149 clk->ops = &clk_nodrv_ops;
2150 clk_enable_unlock(flags);
2151
2152 if (!hlist_empty(&clk->children)) {
2153 struct clk *child;
2154
2155 /* Reparent all children to the orphan list. */
2156 hlist_for_each_entry(child, &clk->children, child_node)
2157 clk_set_parent(child, NULL);
2158 }
2159
2160 clk_debug_unregister(clk);
2161
2162 hlist_del_init(&clk->child_node);
2163
2164 if (clk->prepare_count)
2165 pr_warn("%s: unregistering prepared clock: %s\n",
2166 __func__, clk->name);
2167
2168 kref_put(&clk->ref, __clk_release);
2169out:
2170 clk_prepare_unlock();
2171}
Mark Brown1df5c932012-04-18 09:07:12 +01002172EXPORT_SYMBOL_GPL(clk_unregister);
2173
Stephen Boyd46c87732012-09-24 13:38:04 -07002174static void devm_clk_release(struct device *dev, void *res)
2175{
2176 clk_unregister(res);
2177}
2178
2179/**
2180 * devm_clk_register - resource managed clk_register()
2181 * @dev: device that is registering this clock
2182 * @hw: link to hardware-specific clock data
2183 *
2184 * Managed clk_register(). Clocks returned from this function are
2185 * automatically clk_unregister()ed on driver detach. See clk_register() for
2186 * more information.
2187 */
2188struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
2189{
2190 struct clk *clk;
2191 int ret;
2192
2193 clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL);
2194 if (!clk)
2195 return ERR_PTR(-ENOMEM);
2196
2197 ret = _clk_register(dev, hw, clk);
2198 if (!ret) {
2199 devres_add(dev, clk);
2200 } else {
2201 devres_free(clk);
2202 clk = ERR_PTR(ret);
2203 }
2204
2205 return clk;
2206}
2207EXPORT_SYMBOL_GPL(devm_clk_register);
2208
2209static int devm_clk_match(struct device *dev, void *res, void *data)
2210{
2211 struct clk *c = res;
2212 if (WARN_ON(!c))
2213 return 0;
2214 return c == data;
2215}
2216
2217/**
2218 * devm_clk_unregister - resource managed clk_unregister()
2219 * @clk: clock to unregister
2220 *
2221 * Deallocate a clock allocated with devm_clk_register(). Normally
2222 * this function will not need to be called and the resource management
2223 * code will ensure that the resource is freed.
2224 */
2225void devm_clk_unregister(struct device *dev, struct clk *clk)
2226{
2227 WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk));
2228}
2229EXPORT_SYMBOL_GPL(devm_clk_unregister);
2230
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002231/*
2232 * clkdev helpers
2233 */
2234int __clk_get(struct clk *clk)
2235{
Sylwester Nawrocki00efcb12014-01-07 13:03:43 +01002236 if (clk) {
2237 if (!try_module_get(clk->owner))
2238 return 0;
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002239
Sylwester Nawrocki00efcb12014-01-07 13:03:43 +01002240 kref_get(&clk->ref);
2241 }
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002242 return 1;
2243}
2244
2245void __clk_put(struct clk *clk)
2246{
Sylwester Nawrocki00efcb12014-01-07 13:03:43 +01002247 if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002248 return;
2249
Sylwester Nawrockifcb0ee62013-08-24 15:00:10 +02002250 clk_prepare_lock();
2251 kref_put(&clk->ref, __clk_release);
2252 clk_prepare_unlock();
2253
Sylwester Nawrocki00efcb12014-01-07 13:03:43 +01002254 module_put(clk->owner);
Sylwester Nawrockiac2df522013-08-24 20:10:41 +02002255}
2256
Mike Turquetteb24764902012-03-15 23:11:19 -07002257/*** clk rate change notifiers ***/
2258
2259/**
2260 * clk_notifier_register - add a clk rate change notifier
2261 * @clk: struct clk * to watch
2262 * @nb: struct notifier_block * with callback info
2263 *
2264 * Request notification when clk's rate changes. This uses an SRCU
2265 * notifier because we want it to block and notifier unregistrations are
2266 * uncommon. The callbacks associated with the notifier must not
2267 * re-enter into the clk framework by calling any top-level clk APIs;
2268 * this will cause a nested prepare_lock mutex.
2269 *
Soren Brinkmann5324fda2014-01-22 11:48:37 -08002270 * In all notification cases cases (pre, post and abort rate change) the
2271 * original clock rate is passed to the callback via struct
2272 * clk_notifier_data.old_rate and the new frequency is passed via struct
Mike Turquetteb24764902012-03-15 23:11:19 -07002273 * clk_notifier_data.new_rate.
2274 *
Mike Turquetteb24764902012-03-15 23:11:19 -07002275 * clk_notifier_register() must be called from non-atomic context.
2276 * Returns -EINVAL if called with null arguments, -ENOMEM upon
2277 * allocation failure; otherwise, passes along the return value of
2278 * srcu_notifier_chain_register().
2279 */
2280int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
2281{
2282 struct clk_notifier *cn;
2283 int ret = -ENOMEM;
2284
2285 if (!clk || !nb)
2286 return -EINVAL;
2287
Mike Turquetteeab89f62013-03-28 13:59:01 -07002288 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002289
2290 /* search the list of notifiers for this clk */
2291 list_for_each_entry(cn, &clk_notifier_list, node)
2292 if (cn->clk == clk)
2293 break;
2294
2295 /* if clk wasn't in the notifier list, allocate new clk_notifier */
2296 if (cn->clk != clk) {
2297 cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL);
2298 if (!cn)
2299 goto out;
2300
2301 cn->clk = clk;
2302 srcu_init_notifier_head(&cn->notifier_head);
2303
2304 list_add(&cn->node, &clk_notifier_list);
2305 }
2306
2307 ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
2308
2309 clk->notifier_count++;
2310
2311out:
Mike Turquetteeab89f62013-03-28 13:59:01 -07002312 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002313
2314 return ret;
2315}
2316EXPORT_SYMBOL_GPL(clk_notifier_register);
2317
2318/**
2319 * clk_notifier_unregister - remove a clk rate change notifier
2320 * @clk: struct clk *
2321 * @nb: struct notifier_block * with callback info
2322 *
2323 * Request no further notification for changes to 'clk' and frees memory
2324 * allocated in clk_notifier_register.
2325 *
2326 * Returns -EINVAL if called with null arguments; otherwise, passes
2327 * along the return value of srcu_notifier_chain_unregister().
2328 */
2329int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
2330{
2331 struct clk_notifier *cn = NULL;
2332 int ret = -EINVAL;
2333
2334 if (!clk || !nb)
2335 return -EINVAL;
2336
Mike Turquetteeab89f62013-03-28 13:59:01 -07002337 clk_prepare_lock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002338
2339 list_for_each_entry(cn, &clk_notifier_list, node)
2340 if (cn->clk == clk)
2341 break;
2342
2343 if (cn->clk == clk) {
2344 ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
2345
2346 clk->notifier_count--;
2347
2348 /* XXX the notifier code should handle this better */
2349 if (!cn->notifier_head.head) {
2350 srcu_cleanup_notifier_head(&cn->notifier_head);
Lai Jiangshan72b53222013-06-03 17:17:15 +08002351 list_del(&cn->node);
Mike Turquetteb24764902012-03-15 23:11:19 -07002352 kfree(cn);
2353 }
2354
2355 } else {
2356 ret = -ENOENT;
2357 }
2358
Mike Turquetteeab89f62013-03-28 13:59:01 -07002359 clk_prepare_unlock();
Mike Turquetteb24764902012-03-15 23:11:19 -07002360
2361 return ret;
2362}
2363EXPORT_SYMBOL_GPL(clk_notifier_unregister);
Grant Likely766e6a42012-04-09 14:50:06 -05002364
2365#ifdef CONFIG_OF
2366/**
2367 * struct of_clk_provider - Clock provider registration structure
2368 * @link: Entry in global list of clock providers
2369 * @node: Pointer to device tree node of clock provider
2370 * @get: Get clock callback. Returns NULL or a struct clk for the
2371 * given clock specifier
2372 * @data: context pointer to be passed into @get callback
2373 */
2374struct of_clk_provider {
2375 struct list_head link;
2376
2377 struct device_node *node;
2378 struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
2379 void *data;
2380};
2381
Prashant Gaikwadf2f6c252013-01-04 12:30:52 +05302382static const struct of_device_id __clk_of_table_sentinel
2383 __used __section(__clk_of_table_end);
2384
Grant Likely766e6a42012-04-09 14:50:06 -05002385static LIST_HEAD(of_clk_providers);
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002386static DEFINE_MUTEX(of_clk_mutex);
2387
2388/* of_clk_provider list locking helpers */
2389void of_clk_lock(void)
2390{
2391 mutex_lock(&of_clk_mutex);
2392}
2393
2394void of_clk_unlock(void)
2395{
2396 mutex_unlock(&of_clk_mutex);
2397}
Grant Likely766e6a42012-04-09 14:50:06 -05002398
2399struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
2400 void *data)
2401{
2402 return data;
2403}
2404EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
2405
Shawn Guo494bfec2012-08-22 21:36:27 +08002406struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
2407{
2408 struct clk_onecell_data *clk_data = data;
2409 unsigned int idx = clkspec->args[0];
2410
2411 if (idx >= clk_data->clk_num) {
2412 pr_err("%s: invalid clock index %d\n", __func__, idx);
2413 return ERR_PTR(-EINVAL);
2414 }
2415
2416 return clk_data->clks[idx];
2417}
2418EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
2419
Grant Likely766e6a42012-04-09 14:50:06 -05002420/**
2421 * of_clk_add_provider() - Register a clock provider for a node
2422 * @np: Device node pointer associated with clock provider
2423 * @clk_src_get: callback for decoding clock
2424 * @data: context pointer for @clk_src_get callback.
2425 */
2426int of_clk_add_provider(struct device_node *np,
2427 struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
2428 void *data),
2429 void *data)
2430{
2431 struct of_clk_provider *cp;
2432
2433 cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL);
2434 if (!cp)
2435 return -ENOMEM;
2436
2437 cp->node = of_node_get(np);
2438 cp->data = data;
2439 cp->get = clk_src_get;
2440
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002441 mutex_lock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002442 list_add(&cp->link, &of_clk_providers);
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002443 mutex_unlock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002444 pr_debug("Added clock from %s\n", np->full_name);
2445
2446 return 0;
2447}
2448EXPORT_SYMBOL_GPL(of_clk_add_provider);
2449
2450/**
2451 * of_clk_del_provider() - Remove a previously registered clock provider
2452 * @np: Device node pointer associated with clock provider
2453 */
2454void of_clk_del_provider(struct device_node *np)
2455{
2456 struct of_clk_provider *cp;
2457
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002458 mutex_lock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002459 list_for_each_entry(cp, &of_clk_providers, link) {
2460 if (cp->node == np) {
2461 list_del(&cp->link);
2462 of_node_put(cp->node);
2463 kfree(cp);
2464 break;
2465 }
2466 }
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002467 mutex_unlock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002468}
2469EXPORT_SYMBOL_GPL(of_clk_del_provider);
2470
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002471struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec)
Grant Likely766e6a42012-04-09 14:50:06 -05002472{
2473 struct of_clk_provider *provider;
Jean-Francois Moinea34cd462013-11-25 19:47:04 +01002474 struct clk *clk = ERR_PTR(-EPROBE_DEFER);
Grant Likely766e6a42012-04-09 14:50:06 -05002475
2476 /* Check if we have such a provider in our array */
Grant Likely766e6a42012-04-09 14:50:06 -05002477 list_for_each_entry(provider, &of_clk_providers, link) {
2478 if (provider->node == clkspec->np)
2479 clk = provider->get(clkspec, provider->data);
2480 if (!IS_ERR(clk))
2481 break;
2482 }
Sylwester Nawrockid6782c22013-08-23 17:03:43 +02002483
2484 return clk;
2485}
2486
2487struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
2488{
2489 struct clk *clk;
2490
2491 mutex_lock(&of_clk_mutex);
2492 clk = __of_clk_get_from_provider(clkspec);
2493 mutex_unlock(&of_clk_mutex);
Grant Likely766e6a42012-04-09 14:50:06 -05002494
2495 return clk;
2496}
2497
Mike Turquettef6102742013-10-07 23:12:13 -07002498int of_clk_get_parent_count(struct device_node *np)
2499{
2500 return of_count_phandle_with_args(np, "clocks", "#clock-cells");
2501}
2502EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
2503
Grant Likely766e6a42012-04-09 14:50:06 -05002504const char *of_clk_get_parent_name(struct device_node *np, int index)
2505{
2506 struct of_phandle_args clkspec;
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00002507 struct property *prop;
Grant Likely766e6a42012-04-09 14:50:06 -05002508 const char *clk_name;
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00002509 const __be32 *vp;
2510 u32 pv;
Grant Likely766e6a42012-04-09 14:50:06 -05002511 int rc;
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00002512 int count;
Grant Likely766e6a42012-04-09 14:50:06 -05002513
2514 if (index < 0)
2515 return NULL;
2516
2517 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
2518 &clkspec);
2519 if (rc)
2520 return NULL;
2521
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00002522 index = clkspec.args_count ? clkspec.args[0] : 0;
2523 count = 0;
2524
2525 /* if there is an indices property, use it to transfer the index
2526 * specified into an array offset for the clock-output-names property.
2527 */
2528 of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) {
2529 if (index == pv) {
2530 index = count;
2531 break;
2532 }
2533 count++;
2534 }
2535
Grant Likely766e6a42012-04-09 14:50:06 -05002536 if (of_property_read_string_index(clkspec.np, "clock-output-names",
Ben Dooks7a0fc1a2014-02-13 18:02:49 +00002537 index,
Grant Likely766e6a42012-04-09 14:50:06 -05002538 &clk_name) < 0)
2539 clk_name = clkspec.np->name;
2540
2541 of_node_put(clkspec.np);
2542 return clk_name;
2543}
2544EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
2545
Gregory CLEMENT1771b102014-02-24 19:10:13 +01002546struct clock_provider {
2547 of_clk_init_cb_t clk_init_cb;
2548 struct device_node *np;
2549 struct list_head node;
2550};
2551
2552static LIST_HEAD(clk_provider_list);
2553
2554/*
2555 * This function looks for a parent clock. If there is one, then it
2556 * checks that the provider for this parent clock was initialized, in
2557 * this case the parent clock will be ready.
2558 */
2559static int parent_ready(struct device_node *np)
2560{
2561 int i = 0;
2562
2563 while (true) {
2564 struct clk *clk = of_clk_get(np, i);
2565
2566 /* this parent is ready we can check the next one */
2567 if (!IS_ERR(clk)) {
2568 clk_put(clk);
2569 i++;
2570 continue;
2571 }
2572
2573 /* at least one parent is not ready, we exit now */
2574 if (PTR_ERR(clk) == -EPROBE_DEFER)
2575 return 0;
2576
2577 /*
2578 * Here we make assumption that the device tree is
2579 * written correctly. So an error means that there is
2580 * no more parent. As we didn't exit yet, then the
2581 * previous parent are ready. If there is no clock
2582 * parent, no need to wait for them, then we can
2583 * consider their absence as being ready
2584 */
2585 return 1;
2586 }
2587}
2588
Grant Likely766e6a42012-04-09 14:50:06 -05002589/**
2590 * of_clk_init() - Scan and init clock providers from the DT
2591 * @matches: array of compatible values and init functions for providers.
2592 *
Gregory CLEMENT1771b102014-02-24 19:10:13 +01002593 * This function scans the device tree for matching clock providers
2594 * and calls their initialization functions. It also do it by trying
2595 * to follow the dependencies.
Grant Likely766e6a42012-04-09 14:50:06 -05002596 */
2597void __init of_clk_init(const struct of_device_id *matches)
2598{
Alex Elder7f7ed582013-08-22 11:31:31 -05002599 const struct of_device_id *match;
Grant Likely766e6a42012-04-09 14:50:06 -05002600 struct device_node *np;
Gregory CLEMENT1771b102014-02-24 19:10:13 +01002601 struct clock_provider *clk_provider, *next;
2602 bool is_init_done;
2603 bool force = false;
Grant Likely766e6a42012-04-09 14:50:06 -05002604
Prashant Gaikwadf2f6c252013-01-04 12:30:52 +05302605 if (!matches)
Tero Kristo819b4862013-10-22 11:39:36 +03002606 matches = &__clk_of_table;
Prashant Gaikwadf2f6c252013-01-04 12:30:52 +05302607
Gregory CLEMENT1771b102014-02-24 19:10:13 +01002608 /* First prepare the list of the clocks providers */
Alex Elder7f7ed582013-08-22 11:31:31 -05002609 for_each_matching_node_and_match(np, matches, &match) {
Gregory CLEMENT1771b102014-02-24 19:10:13 +01002610 struct clock_provider *parent =
2611 kzalloc(sizeof(struct clock_provider), GFP_KERNEL);
2612
2613 parent->clk_init_cb = match->data;
2614 parent->np = np;
Sylwester Nawrocki3f6d4392014-03-27 11:43:32 +01002615 list_add_tail(&parent->node, &clk_provider_list);
Gregory CLEMENT1771b102014-02-24 19:10:13 +01002616 }
2617
2618 while (!list_empty(&clk_provider_list)) {
2619 is_init_done = false;
2620 list_for_each_entry_safe(clk_provider, next,
2621 &clk_provider_list, node) {
2622 if (force || parent_ready(clk_provider->np)) {
2623 clk_provider->clk_init_cb(clk_provider->np);
2624 list_del(&clk_provider->node);
2625 kfree(clk_provider);
2626 is_init_done = true;
2627 }
2628 }
2629
2630 /*
2631 * We didn't managed to initialize any of the
2632 * remaining providers during the last loop, so now we
2633 * initialize all the remaining ones unconditionally
2634 * in case the clock parent was not mandatory
2635 */
2636 if (!is_init_done)
2637 force = true;
2638
Grant Likely766e6a42012-04-09 14:50:06 -05002639 }
2640}
2641#endif