Commit | Line | Data |
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b2476490 MT |
1 | /* |
2 | * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com> | |
3 | * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * Standard functionality for the common clock API. See Documentation/clk.txt | |
10 | */ | |
11 | ||
12 | #include <linux/clk-private.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/mutex.h> | |
15 | #include <linux/spinlock.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/list.h> | |
18 | #include <linux/slab.h> | |
766e6a4e | 19 | #include <linux/of.h> |
46c8773a | 20 | #include <linux/device.h> |
f2f6c255 | 21 | #include <linux/init.h> |
533ddeb1 | 22 | #include <linux/sched.h> |
b2476490 | 23 | |
d6782c26 SN |
24 | #include "clk.h" |
25 | ||
b2476490 MT |
26 | static DEFINE_SPINLOCK(enable_lock); |
27 | static DEFINE_MUTEX(prepare_lock); | |
28 | ||
533ddeb1 MT |
29 | static struct task_struct *prepare_owner; |
30 | static struct task_struct *enable_owner; | |
31 | ||
32 | static int prepare_refcnt; | |
33 | static int enable_refcnt; | |
34 | ||
b2476490 MT |
35 | static HLIST_HEAD(clk_root_list); |
36 | static HLIST_HEAD(clk_orphan_list); | |
37 | static LIST_HEAD(clk_notifier_list); | |
38 | ||
eab89f69 MT |
39 | /*** locking ***/ |
40 | static void clk_prepare_lock(void) | |
41 | { | |
533ddeb1 MT |
42 | if (!mutex_trylock(&prepare_lock)) { |
43 | if (prepare_owner == current) { | |
44 | prepare_refcnt++; | |
45 | return; | |
46 | } | |
47 | mutex_lock(&prepare_lock); | |
48 | } | |
49 | WARN_ON_ONCE(prepare_owner != NULL); | |
50 | WARN_ON_ONCE(prepare_refcnt != 0); | |
51 | prepare_owner = current; | |
52 | prepare_refcnt = 1; | |
eab89f69 MT |
53 | } |
54 | ||
55 | static void clk_prepare_unlock(void) | |
56 | { | |
533ddeb1 MT |
57 | WARN_ON_ONCE(prepare_owner != current); |
58 | WARN_ON_ONCE(prepare_refcnt == 0); | |
59 | ||
60 | if (--prepare_refcnt) | |
61 | return; | |
62 | prepare_owner = NULL; | |
eab89f69 MT |
63 | mutex_unlock(&prepare_lock); |
64 | } | |
65 | ||
66 | static unsigned long clk_enable_lock(void) | |
67 | { | |
68 | unsigned long flags; | |
533ddeb1 MT |
69 | |
70 | if (!spin_trylock_irqsave(&enable_lock, flags)) { | |
71 | if (enable_owner == current) { | |
72 | enable_refcnt++; | |
73 | return flags; | |
74 | } | |
75 | spin_lock_irqsave(&enable_lock, flags); | |
76 | } | |
77 | WARN_ON_ONCE(enable_owner != NULL); | |
78 | WARN_ON_ONCE(enable_refcnt != 0); | |
79 | enable_owner = current; | |
80 | enable_refcnt = 1; | |
eab89f69 MT |
81 | return flags; |
82 | } | |
83 | ||
84 | static void clk_enable_unlock(unsigned long flags) | |
85 | { | |
533ddeb1 MT |
86 | WARN_ON_ONCE(enable_owner != current); |
87 | WARN_ON_ONCE(enable_refcnt == 0); | |
88 | ||
89 | if (--enable_refcnt) | |
90 | return; | |
91 | enable_owner = NULL; | |
eab89f69 MT |
92 | spin_unlock_irqrestore(&enable_lock, flags); |
93 | } | |
94 | ||
b2476490 MT |
95 | /*** debugfs support ***/ |
96 | ||
ea72dc2c | 97 | #ifdef CONFIG_DEBUG_FS |
b2476490 MT |
98 | #include <linux/debugfs.h> |
99 | ||
100 | static struct dentry *rootdir; | |
b2476490 MT |
101 | static int inited = 0; |
102 | ||
6b44c854 SK |
103 | static struct hlist_head *all_lists[] = { |
104 | &clk_root_list, | |
105 | &clk_orphan_list, | |
106 | NULL, | |
107 | }; | |
108 | ||
109 | static struct hlist_head *orphan_list[] = { | |
110 | &clk_orphan_list, | |
111 | NULL, | |
112 | }; | |
113 | ||
1af599df PG |
114 | static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level) |
115 | { | |
116 | if (!c) | |
117 | return; | |
118 | ||
fb8abb7a | 119 | seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu\n", |
1af599df PG |
120 | level * 3 + 1, "", |
121 | 30 - level * 3, c->name, | |
5279fc40 BB |
122 | c->enable_count, c->prepare_count, clk_get_rate(c), |
123 | clk_get_accuracy(c)); | |
1af599df PG |
124 | } |
125 | ||
126 | static void clk_summary_show_subtree(struct seq_file *s, struct clk *c, | |
127 | int level) | |
128 | { | |
129 | struct clk *child; | |
1af599df PG |
130 | |
131 | if (!c) | |
132 | return; | |
133 | ||
134 | clk_summary_show_one(s, c, level); | |
135 | ||
b67bfe0d | 136 | hlist_for_each_entry(child, &c->children, child_node) |
1af599df PG |
137 | clk_summary_show_subtree(s, child, level + 1); |
138 | } | |
139 | ||
140 | static int clk_summary_show(struct seq_file *s, void *data) | |
141 | { | |
142 | struct clk *c; | |
27b8d5f7 | 143 | struct hlist_head **lists = (struct hlist_head **)s->private; |
1af599df | 144 | |
fb8abb7a GU |
145 | seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy\n"); |
146 | seq_puts(s, "--------------------------------------------------------------------------------\n"); | |
1af599df | 147 | |
eab89f69 | 148 | clk_prepare_lock(); |
1af599df | 149 | |
27b8d5f7 PDS |
150 | for (; *lists; lists++) |
151 | hlist_for_each_entry(c, *lists, child_node) | |
152 | clk_summary_show_subtree(s, c, 0); | |
1af599df | 153 | |
eab89f69 | 154 | clk_prepare_unlock(); |
1af599df PG |
155 | |
156 | return 0; | |
157 | } | |
158 | ||
159 | ||
160 | static int clk_summary_open(struct inode *inode, struct file *file) | |
161 | { | |
162 | return single_open(file, clk_summary_show, inode->i_private); | |
163 | } | |
164 | ||
165 | static const struct file_operations clk_summary_fops = { | |
166 | .open = clk_summary_open, | |
167 | .read = seq_read, | |
168 | .llseek = seq_lseek, | |
169 | .release = single_release, | |
170 | }; | |
171 | ||
bddca894 PG |
172 | static void clk_dump_one(struct seq_file *s, struct clk *c, int level) |
173 | { | |
174 | if (!c) | |
175 | return; | |
176 | ||
177 | seq_printf(s, "\"%s\": { ", c->name); | |
178 | seq_printf(s, "\"enable_count\": %d,", c->enable_count); | |
179 | seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); | |
670decdd | 180 | seq_printf(s, "\"rate\": %lu", clk_get_rate(c)); |
5279fc40 | 181 | seq_printf(s, "\"accuracy\": %lu", clk_get_accuracy(c)); |
bddca894 PG |
182 | } |
183 | ||
184 | static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) | |
185 | { | |
186 | struct clk *child; | |
bddca894 PG |
187 | |
188 | if (!c) | |
189 | return; | |
190 | ||
191 | clk_dump_one(s, c, level); | |
192 | ||
b67bfe0d | 193 | hlist_for_each_entry(child, &c->children, child_node) { |
bddca894 PG |
194 | seq_printf(s, ","); |
195 | clk_dump_subtree(s, child, level + 1); | |
196 | } | |
197 | ||
198 | seq_printf(s, "}"); | |
199 | } | |
200 | ||
201 | static int clk_dump(struct seq_file *s, void *data) | |
202 | { | |
203 | struct clk *c; | |
bddca894 | 204 | bool first_node = true; |
27b8d5f7 | 205 | struct hlist_head **lists = (struct hlist_head **)s->private; |
bddca894 PG |
206 | |
207 | seq_printf(s, "{"); | |
208 | ||
eab89f69 | 209 | clk_prepare_lock(); |
bddca894 | 210 | |
27b8d5f7 PDS |
211 | for (; *lists; lists++) { |
212 | hlist_for_each_entry(c, *lists, child_node) { | |
213 | if (!first_node) | |
214 | seq_puts(s, ","); | |
215 | first_node = false; | |
216 | clk_dump_subtree(s, c, 0); | |
217 | } | |
bddca894 PG |
218 | } |
219 | ||
eab89f69 | 220 | clk_prepare_unlock(); |
bddca894 PG |
221 | |
222 | seq_printf(s, "}"); | |
223 | return 0; | |
224 | } | |
225 | ||
226 | ||
227 | static int clk_dump_open(struct inode *inode, struct file *file) | |
228 | { | |
229 | return single_open(file, clk_dump, inode->i_private); | |
230 | } | |
231 | ||
232 | static const struct file_operations clk_dump_fops = { | |
233 | .open = clk_dump_open, | |
234 | .read = seq_read, | |
235 | .llseek = seq_lseek, | |
236 | .release = single_release, | |
237 | }; | |
238 | ||
b2476490 MT |
239 | /* caller must hold prepare_lock */ |
240 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) | |
241 | { | |
242 | struct dentry *d; | |
243 | int ret = -ENOMEM; | |
244 | ||
245 | if (!clk || !pdentry) { | |
246 | ret = -EINVAL; | |
247 | goto out; | |
248 | } | |
249 | ||
250 | d = debugfs_create_dir(clk->name, pdentry); | |
251 | if (!d) | |
252 | goto out; | |
253 | ||
254 | clk->dentry = d; | |
255 | ||
256 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, | |
257 | (u32 *)&clk->rate); | |
258 | if (!d) | |
259 | goto err_out; | |
260 | ||
5279fc40 BB |
261 | d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry, |
262 | (u32 *)&clk->accuracy); | |
263 | if (!d) | |
264 | goto err_out; | |
265 | ||
b2476490 MT |
266 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, |
267 | (u32 *)&clk->flags); | |
268 | if (!d) | |
269 | goto err_out; | |
270 | ||
271 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, | |
272 | (u32 *)&clk->prepare_count); | |
273 | if (!d) | |
274 | goto err_out; | |
275 | ||
276 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, | |
277 | (u32 *)&clk->enable_count); | |
278 | if (!d) | |
279 | goto err_out; | |
280 | ||
281 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, | |
282 | (u32 *)&clk->notifier_count); | |
283 | if (!d) | |
284 | goto err_out; | |
285 | ||
c646cbf1 AE |
286 | if (clk->ops->debug_init) |
287 | if (clk->ops->debug_init(clk->hw, clk->dentry)) | |
288 | goto err_out; | |
289 | ||
b2476490 MT |
290 | ret = 0; |
291 | goto out; | |
292 | ||
293 | err_out: | |
b5f98e65 AE |
294 | debugfs_remove_recursive(clk->dentry); |
295 | clk->dentry = NULL; | |
b2476490 MT |
296 | out: |
297 | return ret; | |
298 | } | |
299 | ||
300 | /* caller must hold prepare_lock */ | |
301 | static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry) | |
302 | { | |
303 | struct clk *child; | |
b2476490 MT |
304 | int ret = -EINVAL;; |
305 | ||
306 | if (!clk || !pdentry) | |
307 | goto out; | |
308 | ||
309 | ret = clk_debug_create_one(clk, pdentry); | |
310 | ||
311 | if (ret) | |
312 | goto out; | |
313 | ||
b67bfe0d | 314 | hlist_for_each_entry(child, &clk->children, child_node) |
27b8d5f7 | 315 | clk_debug_create_subtree(child, pdentry); |
b2476490 MT |
316 | |
317 | ret = 0; | |
318 | out: | |
319 | return ret; | |
320 | } | |
321 | ||
322 | /** | |
323 | * clk_debug_register - add a clk node to the debugfs clk tree | |
324 | * @clk: the clk being added to the debugfs clk tree | |
325 | * | |
326 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been | |
327 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
328 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
329 | * | |
330 | * Caller must hold prepare_lock. Only clk_init calls this function (so | |
331 | * far) so this is taken care. | |
332 | */ | |
333 | static int clk_debug_register(struct clk *clk) | |
334 | { | |
b2476490 MT |
335 | int ret = 0; |
336 | ||
337 | if (!inited) | |
338 | goto out; | |
339 | ||
27b8d5f7 | 340 | ret = clk_debug_create_subtree(clk, rootdir); |
b2476490 MT |
341 | |
342 | out: | |
343 | return ret; | |
344 | } | |
345 | ||
fcb0ee6a SN |
346 | /** |
347 | * clk_debug_unregister - remove a clk node from the debugfs clk tree | |
348 | * @clk: the clk being removed from the debugfs clk tree | |
349 | * | |
350 | * Dynamically removes a clk and all it's children clk nodes from the | |
351 | * debugfs clk tree if clk->dentry points to debugfs created by | |
352 | * clk_debug_register in __clk_init. | |
353 | * | |
354 | * Caller must hold prepare_lock. | |
355 | */ | |
356 | static void clk_debug_unregister(struct clk *clk) | |
357 | { | |
358 | debugfs_remove_recursive(clk->dentry); | |
359 | } | |
360 | ||
fb2b3c9f PDS |
361 | struct dentry *clk_debugfs_add_file(struct clk *clk, char *name, umode_t mode, |
362 | void *data, const struct file_operations *fops) | |
363 | { | |
364 | struct dentry *d = NULL; | |
365 | ||
366 | if (clk->dentry) | |
367 | d = debugfs_create_file(name, mode, clk->dentry, data, fops); | |
368 | ||
369 | return d; | |
370 | } | |
371 | EXPORT_SYMBOL_GPL(clk_debugfs_add_file); | |
372 | ||
b2476490 MT |
373 | /** |
374 | * clk_debug_init - lazily create the debugfs clk tree visualization | |
375 | * | |
376 | * clks are often initialized very early during boot before memory can | |
377 | * be dynamically allocated and well before debugfs is setup. | |
378 | * clk_debug_init walks the clk tree hierarchy while holding | |
379 | * prepare_lock and creates the topology as part of a late_initcall, | |
380 | * thus insuring that clks initialized very early will still be | |
381 | * represented in the debugfs clk tree. This function should only be | |
382 | * called once at boot-time, and all other clks added dynamically will | |
383 | * be done so with clk_debug_register. | |
384 | */ | |
385 | static int __init clk_debug_init(void) | |
386 | { | |
387 | struct clk *clk; | |
1af599df | 388 | struct dentry *d; |
b2476490 MT |
389 | |
390 | rootdir = debugfs_create_dir("clk", NULL); | |
391 | ||
392 | if (!rootdir) | |
393 | return -ENOMEM; | |
394 | ||
27b8d5f7 | 395 | d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists, |
1af599df PG |
396 | &clk_summary_fops); |
397 | if (!d) | |
398 | return -ENOMEM; | |
399 | ||
27b8d5f7 | 400 | d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists, |
bddca894 PG |
401 | &clk_dump_fops); |
402 | if (!d) | |
403 | return -ENOMEM; | |
404 | ||
27b8d5f7 PDS |
405 | d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir, |
406 | &orphan_list, &clk_summary_fops); | |
407 | if (!d) | |
408 | return -ENOMEM; | |
b2476490 | 409 | |
27b8d5f7 PDS |
410 | d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir, |
411 | &orphan_list, &clk_dump_fops); | |
412 | if (!d) | |
b2476490 MT |
413 | return -ENOMEM; |
414 | ||
eab89f69 | 415 | clk_prepare_lock(); |
b2476490 | 416 | |
b67bfe0d | 417 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
418 | clk_debug_create_subtree(clk, rootdir); |
419 | ||
b67bfe0d | 420 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
27b8d5f7 | 421 | clk_debug_create_subtree(clk, rootdir); |
b2476490 MT |
422 | |
423 | inited = 1; | |
424 | ||
eab89f69 | 425 | clk_prepare_unlock(); |
b2476490 MT |
426 | |
427 | return 0; | |
428 | } | |
429 | late_initcall(clk_debug_init); | |
430 | #else | |
431 | static inline int clk_debug_register(struct clk *clk) { return 0; } | |
b33d212f UH |
432 | static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent) |
433 | { | |
434 | } | |
fcb0ee6a SN |
435 | static inline void clk_debug_unregister(struct clk *clk) |
436 | { | |
437 | } | |
70d347e6 | 438 | #endif |
b2476490 | 439 | |
1c155b3d UH |
440 | /* caller must hold prepare_lock */ |
441 | static void clk_unprepare_unused_subtree(struct clk *clk) | |
442 | { | |
443 | struct clk *child; | |
444 | ||
445 | if (!clk) | |
446 | return; | |
447 | ||
448 | hlist_for_each_entry(child, &clk->children, child_node) | |
449 | clk_unprepare_unused_subtree(child); | |
450 | ||
451 | if (clk->prepare_count) | |
452 | return; | |
453 | ||
454 | if (clk->flags & CLK_IGNORE_UNUSED) | |
455 | return; | |
456 | ||
3cc8247f UH |
457 | if (__clk_is_prepared(clk)) { |
458 | if (clk->ops->unprepare_unused) | |
459 | clk->ops->unprepare_unused(clk->hw); | |
460 | else if (clk->ops->unprepare) | |
1c155b3d | 461 | clk->ops->unprepare(clk->hw); |
3cc8247f | 462 | } |
1c155b3d UH |
463 | } |
464 | ||
b2476490 MT |
465 | /* caller must hold prepare_lock */ |
466 | static void clk_disable_unused_subtree(struct clk *clk) | |
467 | { | |
468 | struct clk *child; | |
b2476490 MT |
469 | unsigned long flags; |
470 | ||
471 | if (!clk) | |
472 | goto out; | |
473 | ||
b67bfe0d | 474 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
475 | clk_disable_unused_subtree(child); |
476 | ||
eab89f69 | 477 | flags = clk_enable_lock(); |
b2476490 MT |
478 | |
479 | if (clk->enable_count) | |
480 | goto unlock_out; | |
481 | ||
482 | if (clk->flags & CLK_IGNORE_UNUSED) | |
483 | goto unlock_out; | |
484 | ||
7c045a55 MT |
485 | /* |
486 | * some gate clocks have special needs during the disable-unused | |
487 | * sequence. call .disable_unused if available, otherwise fall | |
488 | * back to .disable | |
489 | */ | |
490 | if (__clk_is_enabled(clk)) { | |
491 | if (clk->ops->disable_unused) | |
492 | clk->ops->disable_unused(clk->hw); | |
493 | else if (clk->ops->disable) | |
494 | clk->ops->disable(clk->hw); | |
495 | } | |
b2476490 MT |
496 | |
497 | unlock_out: | |
eab89f69 | 498 | clk_enable_unlock(flags); |
b2476490 MT |
499 | |
500 | out: | |
501 | return; | |
502 | } | |
503 | ||
1e435256 OJ |
504 | static bool clk_ignore_unused; |
505 | static int __init clk_ignore_unused_setup(char *__unused) | |
506 | { | |
507 | clk_ignore_unused = true; | |
508 | return 1; | |
509 | } | |
510 | __setup("clk_ignore_unused", clk_ignore_unused_setup); | |
511 | ||
b2476490 MT |
512 | static int clk_disable_unused(void) |
513 | { | |
514 | struct clk *clk; | |
b2476490 | 515 | |
1e435256 OJ |
516 | if (clk_ignore_unused) { |
517 | pr_warn("clk: Not disabling unused clocks\n"); | |
518 | return 0; | |
519 | } | |
520 | ||
eab89f69 | 521 | clk_prepare_lock(); |
b2476490 | 522 | |
b67bfe0d | 523 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
524 | clk_disable_unused_subtree(clk); |
525 | ||
b67bfe0d | 526 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
b2476490 MT |
527 | clk_disable_unused_subtree(clk); |
528 | ||
1c155b3d UH |
529 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
530 | clk_unprepare_unused_subtree(clk); | |
531 | ||
532 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) | |
533 | clk_unprepare_unused_subtree(clk); | |
534 | ||
eab89f69 | 535 | clk_prepare_unlock(); |
b2476490 MT |
536 | |
537 | return 0; | |
538 | } | |
d41d5805 | 539 | late_initcall_sync(clk_disable_unused); |
b2476490 MT |
540 | |
541 | /*** helper functions ***/ | |
542 | ||
65800b2c | 543 | const char *__clk_get_name(struct clk *clk) |
b2476490 MT |
544 | { |
545 | return !clk ? NULL : clk->name; | |
546 | } | |
4895084c | 547 | EXPORT_SYMBOL_GPL(__clk_get_name); |
b2476490 | 548 | |
65800b2c | 549 | struct clk_hw *__clk_get_hw(struct clk *clk) |
b2476490 MT |
550 | { |
551 | return !clk ? NULL : clk->hw; | |
552 | } | |
0b7f04b8 | 553 | EXPORT_SYMBOL_GPL(__clk_get_hw); |
b2476490 | 554 | |
65800b2c | 555 | u8 __clk_get_num_parents(struct clk *clk) |
b2476490 | 556 | { |
2ac6b1f5 | 557 | return !clk ? 0 : clk->num_parents; |
b2476490 | 558 | } |
0b7f04b8 | 559 | EXPORT_SYMBOL_GPL(__clk_get_num_parents); |
b2476490 | 560 | |
65800b2c | 561 | struct clk *__clk_get_parent(struct clk *clk) |
b2476490 MT |
562 | { |
563 | return !clk ? NULL : clk->parent; | |
564 | } | |
0b7f04b8 | 565 | EXPORT_SYMBOL_GPL(__clk_get_parent); |
b2476490 | 566 | |
7ef3dcc8 JH |
567 | struct clk *clk_get_parent_by_index(struct clk *clk, u8 index) |
568 | { | |
569 | if (!clk || index >= clk->num_parents) | |
570 | return NULL; | |
571 | else if (!clk->parents) | |
572 | return __clk_lookup(clk->parent_names[index]); | |
573 | else if (!clk->parents[index]) | |
574 | return clk->parents[index] = | |
575 | __clk_lookup(clk->parent_names[index]); | |
576 | else | |
577 | return clk->parents[index]; | |
578 | } | |
0b7f04b8 | 579 | EXPORT_SYMBOL_GPL(clk_get_parent_by_index); |
7ef3dcc8 | 580 | |
65800b2c | 581 | unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 582 | { |
2ac6b1f5 | 583 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
584 | } |
585 | ||
65800b2c | 586 | unsigned int __clk_get_prepare_count(struct clk *clk) |
b2476490 | 587 | { |
2ac6b1f5 | 588 | return !clk ? 0 : clk->prepare_count; |
b2476490 MT |
589 | } |
590 | ||
591 | unsigned long __clk_get_rate(struct clk *clk) | |
592 | { | |
593 | unsigned long ret; | |
594 | ||
595 | if (!clk) { | |
34e44fe8 | 596 | ret = 0; |
b2476490 MT |
597 | goto out; |
598 | } | |
599 | ||
600 | ret = clk->rate; | |
601 | ||
602 | if (clk->flags & CLK_IS_ROOT) | |
603 | goto out; | |
604 | ||
605 | if (!clk->parent) | |
34e44fe8 | 606 | ret = 0; |
b2476490 MT |
607 | |
608 | out: | |
609 | return ret; | |
610 | } | |
0b7f04b8 | 611 | EXPORT_SYMBOL_GPL(__clk_get_rate); |
b2476490 | 612 | |
5279fc40 BB |
613 | unsigned long __clk_get_accuracy(struct clk *clk) |
614 | { | |
615 | if (!clk) | |
616 | return 0; | |
617 | ||
618 | return clk->accuracy; | |
619 | } | |
620 | ||
65800b2c | 621 | unsigned long __clk_get_flags(struct clk *clk) |
b2476490 | 622 | { |
2ac6b1f5 | 623 | return !clk ? 0 : clk->flags; |
b2476490 | 624 | } |
b05c6836 | 625 | EXPORT_SYMBOL_GPL(__clk_get_flags); |
b2476490 | 626 | |
3d6ee287 UH |
627 | bool __clk_is_prepared(struct clk *clk) |
628 | { | |
629 | int ret; | |
630 | ||
631 | if (!clk) | |
632 | return false; | |
633 | ||
634 | /* | |
635 | * .is_prepared is optional for clocks that can prepare | |
636 | * fall back to software usage counter if it is missing | |
637 | */ | |
638 | if (!clk->ops->is_prepared) { | |
639 | ret = clk->prepare_count ? 1 : 0; | |
640 | goto out; | |
641 | } | |
642 | ||
643 | ret = clk->ops->is_prepared(clk->hw); | |
644 | out: | |
645 | return !!ret; | |
646 | } | |
647 | ||
2ac6b1f5 | 648 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
649 | { |
650 | int ret; | |
651 | ||
652 | if (!clk) | |
2ac6b1f5 | 653 | return false; |
b2476490 MT |
654 | |
655 | /* | |
656 | * .is_enabled is only mandatory for clocks that gate | |
657 | * fall back to software usage counter if .is_enabled is missing | |
658 | */ | |
659 | if (!clk->ops->is_enabled) { | |
660 | ret = clk->enable_count ? 1 : 0; | |
661 | goto out; | |
662 | } | |
663 | ||
664 | ret = clk->ops->is_enabled(clk->hw); | |
665 | out: | |
2ac6b1f5 | 666 | return !!ret; |
b2476490 | 667 | } |
0b7f04b8 | 668 | EXPORT_SYMBOL_GPL(__clk_is_enabled); |
b2476490 MT |
669 | |
670 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
671 | { | |
672 | struct clk *child; | |
673 | struct clk *ret; | |
b2476490 MT |
674 | |
675 | if (!strcmp(clk->name, name)) | |
676 | return clk; | |
677 | ||
b67bfe0d | 678 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
679 | ret = __clk_lookup_subtree(name, child); |
680 | if (ret) | |
681 | return ret; | |
682 | } | |
683 | ||
684 | return NULL; | |
685 | } | |
686 | ||
687 | struct clk *__clk_lookup(const char *name) | |
688 | { | |
689 | struct clk *root_clk; | |
690 | struct clk *ret; | |
b2476490 MT |
691 | |
692 | if (!name) | |
693 | return NULL; | |
694 | ||
695 | /* search the 'proper' clk tree first */ | |
b67bfe0d | 696 | hlist_for_each_entry(root_clk, &clk_root_list, child_node) { |
b2476490 MT |
697 | ret = __clk_lookup_subtree(name, root_clk); |
698 | if (ret) | |
699 | return ret; | |
700 | } | |
701 | ||
702 | /* if not found, then search the orphan tree */ | |
b67bfe0d | 703 | hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { |
b2476490 MT |
704 | ret = __clk_lookup_subtree(name, root_clk); |
705 | if (ret) | |
706 | return ret; | |
707 | } | |
708 | ||
709 | return NULL; | |
710 | } | |
711 | ||
e366fdd7 JH |
712 | /* |
713 | * Helper for finding best parent to provide a given frequency. This can be used | |
714 | * directly as a determine_rate callback (e.g. for a mux), or from a more | |
715 | * complex clock that may combine a mux with other operations. | |
716 | */ | |
717 | long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, | |
718 | unsigned long *best_parent_rate, | |
719 | struct clk **best_parent_p) | |
720 | { | |
721 | struct clk *clk = hw->clk, *parent, *best_parent = NULL; | |
722 | int i, num_parents; | |
723 | unsigned long parent_rate, best = 0; | |
724 | ||
725 | /* if NO_REPARENT flag set, pass through to current parent */ | |
726 | if (clk->flags & CLK_SET_RATE_NO_REPARENT) { | |
727 | parent = clk->parent; | |
728 | if (clk->flags & CLK_SET_RATE_PARENT) | |
729 | best = __clk_round_rate(parent, rate); | |
730 | else if (parent) | |
731 | best = __clk_get_rate(parent); | |
732 | else | |
733 | best = __clk_get_rate(clk); | |
734 | goto out; | |
735 | } | |
736 | ||
737 | /* find the parent that can provide the fastest rate <= rate */ | |
738 | num_parents = clk->num_parents; | |
739 | for (i = 0; i < num_parents; i++) { | |
740 | parent = clk_get_parent_by_index(clk, i); | |
741 | if (!parent) | |
742 | continue; | |
743 | if (clk->flags & CLK_SET_RATE_PARENT) | |
744 | parent_rate = __clk_round_rate(parent, rate); | |
745 | else | |
746 | parent_rate = __clk_get_rate(parent); | |
747 | if (parent_rate <= rate && parent_rate > best) { | |
748 | best_parent = parent; | |
749 | best = parent_rate; | |
750 | } | |
751 | } | |
752 | ||
753 | out: | |
754 | if (best_parent) | |
755 | *best_parent_p = best_parent; | |
756 | *best_parent_rate = best; | |
757 | ||
758 | return best; | |
759 | } | |
0b7f04b8 | 760 | EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); |
e366fdd7 | 761 | |
b2476490 MT |
762 | /*** clk api ***/ |
763 | ||
764 | void __clk_unprepare(struct clk *clk) | |
765 | { | |
766 | if (!clk) | |
767 | return; | |
768 | ||
769 | if (WARN_ON(clk->prepare_count == 0)) | |
770 | return; | |
771 | ||
772 | if (--clk->prepare_count > 0) | |
773 | return; | |
774 | ||
775 | WARN_ON(clk->enable_count > 0); | |
776 | ||
777 | if (clk->ops->unprepare) | |
778 | clk->ops->unprepare(clk->hw); | |
779 | ||
780 | __clk_unprepare(clk->parent); | |
781 | } | |
782 | ||
783 | /** | |
784 | * clk_unprepare - undo preparation of a clock source | |
24ee1a08 | 785 | * @clk: the clk being unprepared |
b2476490 MT |
786 | * |
787 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
788 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
789 | * if the operation may sleep. One example is a clk which is accessed over | |
790 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
791 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
792 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
793 | */ | |
794 | void clk_unprepare(struct clk *clk) | |
795 | { | |
63589e92 SB |
796 | if (IS_ERR_OR_NULL(clk)) |
797 | return; | |
798 | ||
eab89f69 | 799 | clk_prepare_lock(); |
b2476490 | 800 | __clk_unprepare(clk); |
eab89f69 | 801 | clk_prepare_unlock(); |
b2476490 MT |
802 | } |
803 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
804 | ||
805 | int __clk_prepare(struct clk *clk) | |
806 | { | |
807 | int ret = 0; | |
808 | ||
809 | if (!clk) | |
810 | return 0; | |
811 | ||
812 | if (clk->prepare_count == 0) { | |
813 | ret = __clk_prepare(clk->parent); | |
814 | if (ret) | |
815 | return ret; | |
816 | ||
817 | if (clk->ops->prepare) { | |
818 | ret = clk->ops->prepare(clk->hw); | |
819 | if (ret) { | |
820 | __clk_unprepare(clk->parent); | |
821 | return ret; | |
822 | } | |
823 | } | |
824 | } | |
825 | ||
826 | clk->prepare_count++; | |
827 | ||
828 | return 0; | |
829 | } | |
830 | ||
831 | /** | |
832 | * clk_prepare - prepare a clock source | |
833 | * @clk: the clk being prepared | |
834 | * | |
835 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
836 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
837 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
838 | * the complex case a clk ungate operation may require a fast and a slow part. | |
839 | * It is this reason that clk_prepare and clk_enable are not mutually | |
840 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
841 | * Returns 0 on success, -EERROR otherwise. | |
842 | */ | |
843 | int clk_prepare(struct clk *clk) | |
844 | { | |
845 | int ret; | |
846 | ||
eab89f69 | 847 | clk_prepare_lock(); |
b2476490 | 848 | ret = __clk_prepare(clk); |
eab89f69 | 849 | clk_prepare_unlock(); |
b2476490 MT |
850 | |
851 | return ret; | |
852 | } | |
853 | EXPORT_SYMBOL_GPL(clk_prepare); | |
854 | ||
855 | static void __clk_disable(struct clk *clk) | |
856 | { | |
857 | if (!clk) | |
858 | return; | |
859 | ||
860 | if (WARN_ON(clk->enable_count == 0)) | |
861 | return; | |
862 | ||
863 | if (--clk->enable_count > 0) | |
864 | return; | |
865 | ||
866 | if (clk->ops->disable) | |
867 | clk->ops->disable(clk->hw); | |
868 | ||
869 | __clk_disable(clk->parent); | |
870 | } | |
871 | ||
872 | /** | |
873 | * clk_disable - gate a clock | |
874 | * @clk: the clk being gated | |
875 | * | |
876 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
877 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
878 | * clk if the operation is fast and will never sleep. One example is a | |
879 | * SoC-internal clk which is controlled via simple register writes. In the | |
880 | * complex case a clk gate operation may require a fast and a slow part. It is | |
881 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
882 | * In fact clk_disable must be called before clk_unprepare. | |
883 | */ | |
884 | void clk_disable(struct clk *clk) | |
885 | { | |
886 | unsigned long flags; | |
887 | ||
63589e92 SB |
888 | if (IS_ERR_OR_NULL(clk)) |
889 | return; | |
890 | ||
eab89f69 | 891 | flags = clk_enable_lock(); |
b2476490 | 892 | __clk_disable(clk); |
eab89f69 | 893 | clk_enable_unlock(flags); |
b2476490 MT |
894 | } |
895 | EXPORT_SYMBOL_GPL(clk_disable); | |
896 | ||
897 | static int __clk_enable(struct clk *clk) | |
898 | { | |
899 | int ret = 0; | |
900 | ||
901 | if (!clk) | |
902 | return 0; | |
903 | ||
904 | if (WARN_ON(clk->prepare_count == 0)) | |
905 | return -ESHUTDOWN; | |
906 | ||
907 | if (clk->enable_count == 0) { | |
908 | ret = __clk_enable(clk->parent); | |
909 | ||
910 | if (ret) | |
911 | return ret; | |
912 | ||
913 | if (clk->ops->enable) { | |
914 | ret = clk->ops->enable(clk->hw); | |
915 | if (ret) { | |
916 | __clk_disable(clk->parent); | |
917 | return ret; | |
918 | } | |
919 | } | |
920 | } | |
921 | ||
922 | clk->enable_count++; | |
923 | return 0; | |
924 | } | |
925 | ||
926 | /** | |
927 | * clk_enable - ungate a clock | |
928 | * @clk: the clk being ungated | |
929 | * | |
930 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
931 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
932 | * if the operation will never sleep. One example is a SoC-internal clk which | |
933 | * is controlled via simple register writes. In the complex case a clk ungate | |
934 | * operation may require a fast and a slow part. It is this reason that | |
935 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
936 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
937 | * otherwise. | |
938 | */ | |
939 | int clk_enable(struct clk *clk) | |
940 | { | |
941 | unsigned long flags; | |
942 | int ret; | |
943 | ||
eab89f69 | 944 | flags = clk_enable_lock(); |
b2476490 | 945 | ret = __clk_enable(clk); |
eab89f69 | 946 | clk_enable_unlock(flags); |
b2476490 MT |
947 | |
948 | return ret; | |
949 | } | |
950 | EXPORT_SYMBOL_GPL(clk_enable); | |
951 | ||
b2476490 MT |
952 | /** |
953 | * __clk_round_rate - round the given rate for a clk | |
954 | * @clk: round the rate of this clock | |
24ee1a08 | 955 | * @rate: the rate which is to be rounded |
b2476490 MT |
956 | * |
957 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
958 | */ | |
959 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
960 | { | |
81536e07 | 961 | unsigned long parent_rate = 0; |
71472c0c | 962 | struct clk *parent; |
b2476490 MT |
963 | |
964 | if (!clk) | |
2ac6b1f5 | 965 | return 0; |
b2476490 | 966 | |
71472c0c JH |
967 | parent = clk->parent; |
968 | if (parent) | |
969 | parent_rate = parent->rate; | |
970 | ||
971 | if (clk->ops->determine_rate) | |
972 | return clk->ops->determine_rate(clk->hw, rate, &parent_rate, | |
973 | &parent); | |
974 | else if (clk->ops->round_rate) | |
975 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); | |
976 | else if (clk->flags & CLK_SET_RATE_PARENT) | |
977 | return __clk_round_rate(clk->parent, rate); | |
978 | else | |
979 | return clk->rate; | |
b2476490 | 980 | } |
1cdf8ee2 | 981 | EXPORT_SYMBOL_GPL(__clk_round_rate); |
b2476490 MT |
982 | |
983 | /** | |
984 | * clk_round_rate - round the given rate for a clk | |
985 | * @clk: the clk for which we are rounding a rate | |
986 | * @rate: the rate which is to be rounded | |
987 | * | |
988 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
989 | * use which is then returned. If clk doesn't support round_rate operation | |
990 | * then the parent rate is returned. | |
991 | */ | |
992 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
993 | { | |
994 | unsigned long ret; | |
995 | ||
eab89f69 | 996 | clk_prepare_lock(); |
b2476490 | 997 | ret = __clk_round_rate(clk, rate); |
eab89f69 | 998 | clk_prepare_unlock(); |
b2476490 MT |
999 | |
1000 | return ret; | |
1001 | } | |
1002 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
1003 | ||
1004 | /** | |
1005 | * __clk_notify - call clk notifier chain | |
1006 | * @clk: struct clk * that is changing rate | |
1007 | * @msg: clk notifier type (see include/linux/clk.h) | |
1008 | * @old_rate: old clk rate | |
1009 | * @new_rate: new clk rate | |
1010 | * | |
1011 | * Triggers a notifier call chain on the clk rate-change notification | |
1012 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
1013 | * and current rates to the notifier callback. Intended to be called by | |
1014 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
1015 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
1016 | * a driver returns that. | |
1017 | */ | |
1018 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
1019 | unsigned long old_rate, unsigned long new_rate) | |
1020 | { | |
1021 | struct clk_notifier *cn; | |
1022 | struct clk_notifier_data cnd; | |
1023 | int ret = NOTIFY_DONE; | |
1024 | ||
1025 | cnd.clk = clk; | |
1026 | cnd.old_rate = old_rate; | |
1027 | cnd.new_rate = new_rate; | |
1028 | ||
1029 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
1030 | if (cn->clk == clk) { | |
1031 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
1032 | &cnd); | |
1033 | break; | |
1034 | } | |
1035 | } | |
1036 | ||
1037 | return ret; | |
1038 | } | |
1039 | ||
5279fc40 BB |
1040 | /** |
1041 | * __clk_recalc_accuracies | |
1042 | * @clk: first clk in the subtree | |
1043 | * | |
1044 | * Walks the subtree of clks starting with clk and recalculates accuracies as | |
1045 | * it goes. Note that if a clk does not implement the .recalc_accuracy | |
1046 | * callback then it is assumed that the clock will take on the accuracy of it's | |
1047 | * parent. | |
1048 | * | |
1049 | * Caller must hold prepare_lock. | |
1050 | */ | |
1051 | static void __clk_recalc_accuracies(struct clk *clk) | |
1052 | { | |
1053 | unsigned long parent_accuracy = 0; | |
1054 | struct clk *child; | |
1055 | ||
1056 | if (clk->parent) | |
1057 | parent_accuracy = clk->parent->accuracy; | |
1058 | ||
1059 | if (clk->ops->recalc_accuracy) | |
1060 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1061 | parent_accuracy); | |
1062 | else | |
1063 | clk->accuracy = parent_accuracy; | |
1064 | ||
1065 | hlist_for_each_entry(child, &clk->children, child_node) | |
1066 | __clk_recalc_accuracies(child); | |
1067 | } | |
1068 | ||
1069 | /** | |
1070 | * clk_get_accuracy - return the accuracy of clk | |
1071 | * @clk: the clk whose accuracy is being returned | |
1072 | * | |
1073 | * Simply returns the cached accuracy of the clk, unless | |
1074 | * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be | |
1075 | * issued. | |
1076 | * If clk is NULL then returns 0. | |
1077 | */ | |
1078 | long clk_get_accuracy(struct clk *clk) | |
1079 | { | |
1080 | unsigned long accuracy; | |
1081 | ||
1082 | clk_prepare_lock(); | |
1083 | if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE)) | |
1084 | __clk_recalc_accuracies(clk); | |
1085 | ||
1086 | accuracy = __clk_get_accuracy(clk); | |
1087 | clk_prepare_unlock(); | |
1088 | ||
1089 | return accuracy; | |
1090 | } | |
1091 | EXPORT_SYMBOL_GPL(clk_get_accuracy); | |
1092 | ||
8f2c2db1 SB |
1093 | static unsigned long clk_recalc(struct clk *clk, unsigned long parent_rate) |
1094 | { | |
1095 | if (clk->ops->recalc_rate) | |
1096 | return clk->ops->recalc_rate(clk->hw, parent_rate); | |
1097 | return parent_rate; | |
1098 | } | |
1099 | ||
b2476490 MT |
1100 | /** |
1101 | * __clk_recalc_rates | |
1102 | * @clk: first clk in the subtree | |
1103 | * @msg: notification type (see include/linux/clk.h) | |
1104 | * | |
1105 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
1106 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
24ee1a08 | 1107 | * it is assumed that the clock will take on the rate of its parent. |
b2476490 MT |
1108 | * |
1109 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
1110 | * if necessary. | |
1111 | * | |
1112 | * Caller must hold prepare_lock. | |
1113 | */ | |
1114 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
1115 | { | |
1116 | unsigned long old_rate; | |
1117 | unsigned long parent_rate = 0; | |
b2476490 MT |
1118 | struct clk *child; |
1119 | ||
1120 | old_rate = clk->rate; | |
1121 | ||
1122 | if (clk->parent) | |
1123 | parent_rate = clk->parent->rate; | |
1124 | ||
8f2c2db1 | 1125 | clk->rate = clk_recalc(clk, parent_rate); |
b2476490 MT |
1126 | |
1127 | /* | |
1128 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
1129 | * & ABORT_RATE_CHANGE notifiers | |
1130 | */ | |
1131 | if (clk->notifier_count && msg) | |
1132 | __clk_notify(clk, msg, old_rate, clk->rate); | |
1133 | ||
b67bfe0d | 1134 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
1135 | __clk_recalc_rates(child, msg); |
1136 | } | |
1137 | ||
a093bde2 UH |
1138 | /** |
1139 | * clk_get_rate - return the rate of clk | |
1140 | * @clk: the clk whose rate is being returned | |
1141 | * | |
1142 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
1143 | * is set, which means a recalc_rate will be issued. | |
1144 | * If clk is NULL then returns 0. | |
1145 | */ | |
1146 | unsigned long clk_get_rate(struct clk *clk) | |
1147 | { | |
1148 | unsigned long rate; | |
1149 | ||
eab89f69 | 1150 | clk_prepare_lock(); |
a093bde2 UH |
1151 | |
1152 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
1153 | __clk_recalc_rates(clk, 0); | |
1154 | ||
1155 | rate = __clk_get_rate(clk); | |
eab89f69 | 1156 | clk_prepare_unlock(); |
a093bde2 UH |
1157 | |
1158 | return rate; | |
1159 | } | |
1160 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
1161 | ||
f1c8b2ed | 1162 | static int clk_fetch_parent_index(struct clk *clk, struct clk *parent) |
4935b22c | 1163 | { |
f1c8b2ed | 1164 | int i; |
4935b22c | 1165 | |
f1c8b2ed | 1166 | if (!clk->parents) { |
96a7ed90 TF |
1167 | clk->parents = kcalloc(clk->num_parents, |
1168 | sizeof(struct clk *), GFP_KERNEL); | |
f1c8b2ed TF |
1169 | if (!clk->parents) |
1170 | return -ENOMEM; | |
1171 | } | |
4935b22c JH |
1172 | |
1173 | /* | |
1174 | * find index of new parent clock using cached parent ptrs, | |
1175 | * or if not yet cached, use string name comparison and cache | |
1176 | * them now to avoid future calls to __clk_lookup. | |
1177 | */ | |
1178 | for (i = 0; i < clk->num_parents; i++) { | |
da0f0b2c | 1179 | if (clk->parents[i] == parent) |
f1c8b2ed | 1180 | return i; |
da0f0b2c TF |
1181 | |
1182 | if (clk->parents[i]) | |
1183 | continue; | |
1184 | ||
1185 | if (!strcmp(clk->parent_names[i], parent->name)) { | |
1186 | clk->parents[i] = __clk_lookup(parent->name); | |
f1c8b2ed | 1187 | return i; |
4935b22c JH |
1188 | } |
1189 | } | |
1190 | ||
f1c8b2ed | 1191 | return -EINVAL; |
4935b22c JH |
1192 | } |
1193 | ||
1194 | static void clk_reparent(struct clk *clk, struct clk *new_parent) | |
1195 | { | |
1196 | hlist_del(&clk->child_node); | |
1197 | ||
903efc55 JH |
1198 | if (new_parent) { |
1199 | /* avoid duplicate POST_RATE_CHANGE notifications */ | |
1200 | if (new_parent->new_child == clk) | |
1201 | new_parent->new_child = NULL; | |
1202 | ||
4935b22c | 1203 | hlist_add_head(&clk->child_node, &new_parent->children); |
903efc55 | 1204 | } else { |
4935b22c | 1205 | hlist_add_head(&clk->child_node, &clk_orphan_list); |
903efc55 | 1206 | } |
4935b22c JH |
1207 | |
1208 | clk->parent = new_parent; | |
1209 | } | |
1210 | ||
3fa2252b | 1211 | static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent) |
4935b22c JH |
1212 | { |
1213 | unsigned long flags; | |
4935b22c JH |
1214 | struct clk *old_parent = clk->parent; |
1215 | ||
1216 | /* | |
1217 | * Migrate prepare state between parents and prevent race with | |
1218 | * clk_enable(). | |
1219 | * | |
1220 | * If the clock is not prepared, then a race with | |
1221 | * clk_enable/disable() is impossible since we already have the | |
1222 | * prepare lock (future calls to clk_enable() need to be preceded by | |
1223 | * a clk_prepare()). | |
1224 | * | |
1225 | * If the clock is prepared, migrate the prepared state to the new | |
1226 | * parent and also protect against a race with clk_enable() by | |
1227 | * forcing the clock and the new parent on. This ensures that all | |
1228 | * future calls to clk_enable() are practically NOPs with respect to | |
1229 | * hardware and software states. | |
1230 | * | |
1231 | * See also: Comment for clk_set_parent() below. | |
1232 | */ | |
1233 | if (clk->prepare_count) { | |
1234 | __clk_prepare(parent); | |
1235 | clk_enable(parent); | |
1236 | clk_enable(clk); | |
1237 | } | |
1238 | ||
1239 | /* update the clk tree topology */ | |
1240 | flags = clk_enable_lock(); | |
1241 | clk_reparent(clk, parent); | |
1242 | clk_enable_unlock(flags); | |
1243 | ||
3fa2252b SB |
1244 | return old_parent; |
1245 | } | |
1246 | ||
1247 | static void __clk_set_parent_after(struct clk *clk, struct clk *parent, | |
1248 | struct clk *old_parent) | |
1249 | { | |
1250 | /* | |
1251 | * Finish the migration of prepare state and undo the changes done | |
1252 | * for preventing a race with clk_enable(). | |
1253 | */ | |
1254 | if (clk->prepare_count) { | |
1255 | clk_disable(clk); | |
1256 | clk_disable(old_parent); | |
1257 | __clk_unprepare(old_parent); | |
1258 | } | |
3fa2252b SB |
1259 | } |
1260 | ||
1261 | static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) | |
1262 | { | |
1263 | unsigned long flags; | |
1264 | int ret = 0; | |
1265 | struct clk *old_parent; | |
1266 | ||
1267 | old_parent = __clk_set_parent_before(clk, parent); | |
1268 | ||
4935b22c JH |
1269 | /* change clock input source */ |
1270 | if (parent && clk->ops->set_parent) | |
1271 | ret = clk->ops->set_parent(clk->hw, p_index); | |
1272 | ||
1273 | if (ret) { | |
1274 | flags = clk_enable_lock(); | |
1275 | clk_reparent(clk, old_parent); | |
1276 | clk_enable_unlock(flags); | |
1277 | ||
1278 | if (clk->prepare_count) { | |
1279 | clk_disable(clk); | |
1280 | clk_disable(parent); | |
1281 | __clk_unprepare(parent); | |
1282 | } | |
1283 | return ret; | |
1284 | } | |
1285 | ||
3fa2252b | 1286 | __clk_set_parent_after(clk, parent, old_parent); |
4935b22c | 1287 | |
4935b22c JH |
1288 | return 0; |
1289 | } | |
1290 | ||
b2476490 MT |
1291 | /** |
1292 | * __clk_speculate_rates | |
1293 | * @clk: first clk in the subtree | |
1294 | * @parent_rate: the "future" rate of clk's parent | |
1295 | * | |
1296 | * Walks the subtree of clks starting with clk, speculating rates as it | |
1297 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
1298 | * | |
1299 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
1300 | * pre-rate change notifications and returns early if no clks in the | |
1301 | * subtree have subscribed to the notifications. Note that if a clk does not | |
1302 | * implement the .recalc_rate callback then it is assumed that the clock will | |
24ee1a08 | 1303 | * take on the rate of its parent. |
b2476490 MT |
1304 | * |
1305 | * Caller must hold prepare_lock. | |
1306 | */ | |
1307 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
1308 | { | |
b2476490 MT |
1309 | struct clk *child; |
1310 | unsigned long new_rate; | |
1311 | int ret = NOTIFY_DONE; | |
1312 | ||
8f2c2db1 | 1313 | new_rate = clk_recalc(clk, parent_rate); |
b2476490 | 1314 | |
fb72a059 | 1315 | /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ |
b2476490 MT |
1316 | if (clk->notifier_count) |
1317 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
1318 | ||
86bcfa2e MT |
1319 | if (ret & NOTIFY_STOP_MASK) { |
1320 | pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n", | |
1321 | __func__, clk->name, ret); | |
b2476490 | 1322 | goto out; |
86bcfa2e | 1323 | } |
b2476490 | 1324 | |
b67bfe0d | 1325 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 | 1326 | ret = __clk_speculate_rates(child, new_rate); |
fb72a059 | 1327 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1328 | break; |
1329 | } | |
1330 | ||
1331 | out: | |
1332 | return ret; | |
1333 | } | |
1334 | ||
71472c0c JH |
1335 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate, |
1336 | struct clk *new_parent, u8 p_index) | |
b2476490 MT |
1337 | { |
1338 | struct clk *child; | |
b2476490 MT |
1339 | |
1340 | clk->new_rate = new_rate; | |
71472c0c JH |
1341 | clk->new_parent = new_parent; |
1342 | clk->new_parent_index = p_index; | |
1343 | /* include clk in new parent's PRE_RATE_CHANGE notifications */ | |
1344 | clk->new_child = NULL; | |
1345 | if (new_parent && new_parent != clk->parent) | |
1346 | new_parent->new_child = clk; | |
b2476490 | 1347 | |
b67bfe0d | 1348 | hlist_for_each_entry(child, &clk->children, child_node) { |
8f2c2db1 | 1349 | child->new_rate = clk_recalc(child, new_rate); |
71472c0c | 1350 | clk_calc_subtree(child, child->new_rate, NULL, 0); |
b2476490 MT |
1351 | } |
1352 | } | |
1353 | ||
1354 | /* | |
1355 | * calculate the new rates returning the topmost clock that has to be | |
1356 | * changed. | |
1357 | */ | |
1358 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
1359 | { | |
1360 | struct clk *top = clk; | |
71472c0c | 1361 | struct clk *old_parent, *parent; |
81536e07 | 1362 | unsigned long best_parent_rate = 0; |
b2476490 | 1363 | unsigned long new_rate; |
f1c8b2ed | 1364 | int p_index = 0; |
b2476490 | 1365 | |
7452b219 MT |
1366 | /* sanity */ |
1367 | if (IS_ERR_OR_NULL(clk)) | |
1368 | return NULL; | |
1369 | ||
63f5c3b2 | 1370 | /* save parent rate, if it exists */ |
71472c0c JH |
1371 | parent = old_parent = clk->parent; |
1372 | if (parent) | |
1373 | best_parent_rate = parent->rate; | |
1374 | ||
1375 | /* find the closest rate and parent clk/rate */ | |
1376 | if (clk->ops->determine_rate) { | |
1377 | new_rate = clk->ops->determine_rate(clk->hw, rate, | |
1378 | &best_parent_rate, | |
1379 | &parent); | |
1380 | } else if (clk->ops->round_rate) { | |
1381 | new_rate = clk->ops->round_rate(clk->hw, rate, | |
1382 | &best_parent_rate); | |
1383 | } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) { | |
1384 | /* pass-through clock without adjustable parent */ | |
1385 | clk->new_rate = clk->rate; | |
1386 | return NULL; | |
1387 | } else { | |
1388 | /* pass-through clock with adjustable parent */ | |
1389 | top = clk_calc_new_rates(parent, rate); | |
1390 | new_rate = parent->new_rate; | |
63f5c3b2 | 1391 | goto out; |
7452b219 MT |
1392 | } |
1393 | ||
71472c0c JH |
1394 | /* some clocks must be gated to change parent */ |
1395 | if (parent != old_parent && | |
1396 | (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1397 | pr_debug("%s: %s not gated but wants to reparent\n", | |
1398 | __func__, clk->name); | |
b2476490 MT |
1399 | return NULL; |
1400 | } | |
1401 | ||
71472c0c JH |
1402 | /* try finding the new parent index */ |
1403 | if (parent) { | |
1404 | p_index = clk_fetch_parent_index(clk, parent); | |
f1c8b2ed | 1405 | if (p_index < 0) { |
71472c0c JH |
1406 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1407 | __func__, parent->name, clk->name); | |
1408 | return NULL; | |
1409 | } | |
b2476490 MT |
1410 | } |
1411 | ||
71472c0c JH |
1412 | if ((clk->flags & CLK_SET_RATE_PARENT) && parent && |
1413 | best_parent_rate != parent->rate) | |
1414 | top = clk_calc_new_rates(parent, best_parent_rate); | |
b2476490 MT |
1415 | |
1416 | out: | |
71472c0c | 1417 | clk_calc_subtree(clk, new_rate, parent, p_index); |
b2476490 MT |
1418 | |
1419 | return top; | |
1420 | } | |
1421 | ||
1422 | /* | |
1423 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
1424 | * so that in case of an error we can walk down the whole tree again and | |
1425 | * abort the change. | |
1426 | */ | |
1427 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
1428 | { | |
71472c0c | 1429 | struct clk *child, *tmp_clk, *fail_clk = NULL; |
b2476490 MT |
1430 | int ret = NOTIFY_DONE; |
1431 | ||
1432 | if (clk->rate == clk->new_rate) | |
5fda6858 | 1433 | return NULL; |
b2476490 MT |
1434 | |
1435 | if (clk->notifier_count) { | |
1436 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
fb72a059 | 1437 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1438 | fail_clk = clk; |
1439 | } | |
1440 | ||
b67bfe0d | 1441 | hlist_for_each_entry(child, &clk->children, child_node) { |
71472c0c JH |
1442 | /* Skip children who will be reparented to another clock */ |
1443 | if (child->new_parent && child->new_parent != clk) | |
1444 | continue; | |
1445 | tmp_clk = clk_propagate_rate_change(child, event); | |
1446 | if (tmp_clk) | |
1447 | fail_clk = tmp_clk; | |
1448 | } | |
1449 | ||
1450 | /* handle the new child who might not be in clk->children yet */ | |
1451 | if (clk->new_child) { | |
1452 | tmp_clk = clk_propagate_rate_change(clk->new_child, event); | |
1453 | if (tmp_clk) | |
1454 | fail_clk = tmp_clk; | |
b2476490 MT |
1455 | } |
1456 | ||
1457 | return fail_clk; | |
1458 | } | |
1459 | ||
1460 | /* | |
1461 | * walk down a subtree and set the new rates notifying the rate | |
1462 | * change on the way | |
1463 | */ | |
1464 | static void clk_change_rate(struct clk *clk) | |
1465 | { | |
1466 | struct clk *child; | |
1467 | unsigned long old_rate; | |
bf47b4fd | 1468 | unsigned long best_parent_rate = 0; |
3fa2252b SB |
1469 | bool skip_set_rate = false; |
1470 | struct clk *old_parent; | |
b2476490 MT |
1471 | |
1472 | old_rate = clk->rate; | |
1473 | ||
3fa2252b SB |
1474 | if (clk->new_parent) |
1475 | best_parent_rate = clk->new_parent->rate; | |
1476 | else if (clk->parent) | |
bf47b4fd PM |
1477 | best_parent_rate = clk->parent->rate; |
1478 | ||
3fa2252b SB |
1479 | if (clk->new_parent && clk->new_parent != clk->parent) { |
1480 | old_parent = __clk_set_parent_before(clk, clk->new_parent); | |
1481 | ||
1482 | if (clk->ops->set_rate_and_parent) { | |
1483 | skip_set_rate = true; | |
1484 | clk->ops->set_rate_and_parent(clk->hw, clk->new_rate, | |
1485 | best_parent_rate, | |
1486 | clk->new_parent_index); | |
1487 | } else if (clk->ops->set_parent) { | |
1488 | clk->ops->set_parent(clk->hw, clk->new_parent_index); | |
1489 | } | |
1490 | ||
1491 | __clk_set_parent_after(clk, clk->new_parent, old_parent); | |
1492 | } | |
1493 | ||
1494 | if (!skip_set_rate && clk->ops->set_rate) | |
bf47b4fd | 1495 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 | 1496 | |
8f2c2db1 | 1497 | clk->rate = clk_recalc(clk, best_parent_rate); |
b2476490 MT |
1498 | |
1499 | if (clk->notifier_count && old_rate != clk->rate) | |
1500 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
1501 | ||
71472c0c JH |
1502 | hlist_for_each_entry(child, &clk->children, child_node) { |
1503 | /* Skip children who will be reparented to another clock */ | |
1504 | if (child->new_parent && child->new_parent != clk) | |
1505 | continue; | |
b2476490 | 1506 | clk_change_rate(child); |
71472c0c JH |
1507 | } |
1508 | ||
1509 | /* handle the new child who might not be in clk->children yet */ | |
1510 | if (clk->new_child) | |
1511 | clk_change_rate(clk->new_child); | |
b2476490 MT |
1512 | } |
1513 | ||
1514 | /** | |
1515 | * clk_set_rate - specify a new rate for clk | |
1516 | * @clk: the clk whose rate is being changed | |
1517 | * @rate: the new rate for clk | |
1518 | * | |
5654dc94 | 1519 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 1520 | * |
5654dc94 MT |
1521 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
1522 | * propagate up to clk's parent; whether or not this happens depends on the | |
1523 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
1524 | * after calling .round_rate then upstream parent propagation is ignored. If | |
1525 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
24ee1a08 | 1526 | * up to clk's parent and set its rate. Upward propagation will continue |
5654dc94 MT |
1527 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or |
1528 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 1529 | * |
5654dc94 MT |
1530 | * Rate changes are accomplished via tree traversal that also recalculates the |
1531 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
1532 | * |
1533 | * Returns 0 on success, -EERROR otherwise. | |
1534 | */ | |
1535 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
1536 | { | |
1537 | struct clk *top, *fail_clk; | |
1538 | int ret = 0; | |
1539 | ||
89ac8d7a MT |
1540 | if (!clk) |
1541 | return 0; | |
1542 | ||
b2476490 | 1543 | /* prevent racing with updates to the clock topology */ |
eab89f69 | 1544 | clk_prepare_lock(); |
b2476490 MT |
1545 | |
1546 | /* bail early if nothing to do */ | |
34e452a1 | 1547 | if (rate == clk_get_rate(clk)) |
b2476490 MT |
1548 | goto out; |
1549 | ||
7e0fa1b5 | 1550 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
1551 | ret = -EBUSY; |
1552 | goto out; | |
1553 | } | |
1554 | ||
b2476490 MT |
1555 | /* calculate new rates and get the topmost changed clock */ |
1556 | top = clk_calc_new_rates(clk, rate); | |
1557 | if (!top) { | |
1558 | ret = -EINVAL; | |
1559 | goto out; | |
1560 | } | |
1561 | ||
1562 | /* notify that we are about to change rates */ | |
1563 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
1564 | if (fail_clk) { | |
f7363861 | 1565 | pr_debug("%s: failed to set %s rate\n", __func__, |
b2476490 MT |
1566 | fail_clk->name); |
1567 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
1568 | ret = -EBUSY; | |
1569 | goto out; | |
1570 | } | |
1571 | ||
1572 | /* change the rates */ | |
1573 | clk_change_rate(top); | |
1574 | ||
b2476490 | 1575 | out: |
eab89f69 | 1576 | clk_prepare_unlock(); |
b2476490 MT |
1577 | |
1578 | return ret; | |
1579 | } | |
1580 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
1581 | ||
1582 | /** | |
1583 | * clk_get_parent - return the parent of a clk | |
1584 | * @clk: the clk whose parent gets returned | |
1585 | * | |
1586 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
1587 | */ | |
1588 | struct clk *clk_get_parent(struct clk *clk) | |
1589 | { | |
1590 | struct clk *parent; | |
1591 | ||
eab89f69 | 1592 | clk_prepare_lock(); |
b2476490 | 1593 | parent = __clk_get_parent(clk); |
eab89f69 | 1594 | clk_prepare_unlock(); |
b2476490 MT |
1595 | |
1596 | return parent; | |
1597 | } | |
1598 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
1599 | ||
1600 | /* | |
1601 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
1602 | * optional for single-parent clocks. Always call .get_parent if it is | |
1603 | * available and WARN if it is missing for multi-parent clocks. | |
1604 | * | |
1605 | * For single-parent clocks without .get_parent, first check to see if the | |
1606 | * .parents array exists, and if so use it to avoid an expensive tree | |
1607 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
1608 | */ | |
1609 | static struct clk *__clk_init_parent(struct clk *clk) | |
1610 | { | |
1611 | struct clk *ret = NULL; | |
1612 | u8 index; | |
1613 | ||
1614 | /* handle the trivial cases */ | |
1615 | ||
1616 | if (!clk->num_parents) | |
1617 | goto out; | |
1618 | ||
1619 | if (clk->num_parents == 1) { | |
1620 | if (IS_ERR_OR_NULL(clk->parent)) | |
1621 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); | |
1622 | ret = clk->parent; | |
1623 | goto out; | |
1624 | } | |
1625 | ||
1626 | if (!clk->ops->get_parent) { | |
1627 | WARN(!clk->ops->get_parent, | |
1628 | "%s: multi-parent clocks must implement .get_parent\n", | |
1629 | __func__); | |
1630 | goto out; | |
1631 | }; | |
1632 | ||
1633 | /* | |
1634 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1635 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1636 | * clk->parent here; that is done by the calling function | |
1637 | */ | |
1638 | ||
1639 | index = clk->ops->get_parent(clk->hw); | |
1640 | ||
1641 | if (!clk->parents) | |
1642 | clk->parents = | |
96a7ed90 | 1643 | kcalloc(clk->num_parents, sizeof(struct clk *), |
b2476490 MT |
1644 | GFP_KERNEL); |
1645 | ||
7ef3dcc8 | 1646 | ret = clk_get_parent_by_index(clk, index); |
b2476490 MT |
1647 | |
1648 | out: | |
1649 | return ret; | |
1650 | } | |
1651 | ||
b33d212f UH |
1652 | void __clk_reparent(struct clk *clk, struct clk *new_parent) |
1653 | { | |
1654 | clk_reparent(clk, new_parent); | |
5279fc40 | 1655 | __clk_recalc_accuracies(clk); |
b2476490 MT |
1656 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
1657 | } | |
1658 | ||
b2476490 MT |
1659 | /** |
1660 | * clk_set_parent - switch the parent of a mux clk | |
1661 | * @clk: the mux clk whose input we are switching | |
1662 | * @parent: the new input to clk | |
1663 | * | |
f8aa0bd5 SK |
1664 | * Re-parent clk to use parent as its new input source. If clk is in |
1665 | * prepared state, the clk will get enabled for the duration of this call. If | |
1666 | * that's not acceptable for a specific clk (Eg: the consumer can't handle | |
1667 | * that, the reparenting is glitchy in hardware, etc), use the | |
1668 | * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. | |
1669 | * | |
1670 | * After successfully changing clk's parent clk_set_parent will update the | |
1671 | * clk topology, sysfs topology and propagate rate recalculation via | |
1672 | * __clk_recalc_rates. | |
1673 | * | |
1674 | * Returns 0 on success, -EERROR otherwise. | |
b2476490 MT |
1675 | */ |
1676 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
1677 | { | |
1678 | int ret = 0; | |
f1c8b2ed | 1679 | int p_index = 0; |
031dcc9b | 1680 | unsigned long p_rate = 0; |
b2476490 | 1681 | |
89ac8d7a MT |
1682 | if (!clk) |
1683 | return 0; | |
1684 | ||
031dcc9b UH |
1685 | /* verify ops for for multi-parent clks */ |
1686 | if ((clk->num_parents > 1) && (!clk->ops->set_parent)) | |
b2476490 MT |
1687 | return -ENOSYS; |
1688 | ||
1689 | /* prevent racing with updates to the clock topology */ | |
eab89f69 | 1690 | clk_prepare_lock(); |
b2476490 MT |
1691 | |
1692 | if (clk->parent == parent) | |
1693 | goto out; | |
1694 | ||
031dcc9b UH |
1695 | /* check that we are allowed to re-parent if the clock is in use */ |
1696 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1697 | ret = -EBUSY; | |
1698 | goto out; | |
1699 | } | |
1700 | ||
1701 | /* try finding the new parent index */ | |
1702 | if (parent) { | |
1703 | p_index = clk_fetch_parent_index(clk, parent); | |
1704 | p_rate = parent->rate; | |
f1c8b2ed | 1705 | if (p_index < 0) { |
031dcc9b UH |
1706 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1707 | __func__, parent->name, clk->name); | |
f1c8b2ed | 1708 | ret = p_index; |
031dcc9b UH |
1709 | goto out; |
1710 | } | |
1711 | } | |
1712 | ||
b2476490 | 1713 | /* propagate PRE_RATE_CHANGE notifications */ |
f3aab5d6 | 1714 | ret = __clk_speculate_rates(clk, p_rate); |
b2476490 MT |
1715 | |
1716 | /* abort if a driver objects */ | |
fb72a059 | 1717 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1718 | goto out; |
1719 | ||
031dcc9b UH |
1720 | /* do the re-parent */ |
1721 | ret = __clk_set_parent(clk, parent, p_index); | |
b2476490 | 1722 | |
5279fc40 BB |
1723 | /* propagate rate an accuracy recalculation accordingly */ |
1724 | if (ret) { | |
b2476490 | 1725 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); |
5279fc40 | 1726 | } else { |
a68de8e4 | 1727 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
5279fc40 BB |
1728 | __clk_recalc_accuracies(clk); |
1729 | } | |
b2476490 MT |
1730 | |
1731 | out: | |
eab89f69 | 1732 | clk_prepare_unlock(); |
b2476490 MT |
1733 | |
1734 | return ret; | |
1735 | } | |
1736 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1737 | ||
1738 | /** | |
1739 | * __clk_init - initialize the data structures in a struct clk | |
1740 | * @dev: device initializing this clk, placeholder for now | |
1741 | * @clk: clk being initialized | |
1742 | * | |
1743 | * Initializes the lists in struct clk, queries the hardware for the | |
1744 | * parent and rate and sets them both. | |
b2476490 | 1745 | */ |
d1302a36 | 1746 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1747 | { |
d1302a36 | 1748 | int i, ret = 0; |
b2476490 | 1749 | struct clk *orphan; |
b67bfe0d | 1750 | struct hlist_node *tmp2; |
b2476490 MT |
1751 | |
1752 | if (!clk) | |
d1302a36 | 1753 | return -EINVAL; |
b2476490 | 1754 | |
eab89f69 | 1755 | clk_prepare_lock(); |
b2476490 MT |
1756 | |
1757 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1758 | if (__clk_lookup(clk->name)) { |
1759 | pr_debug("%s: clk %s already initialized\n", | |
1760 | __func__, clk->name); | |
1761 | ret = -EEXIST; | |
b2476490 | 1762 | goto out; |
d1302a36 | 1763 | } |
b2476490 | 1764 | |
d4d7e3dd MT |
1765 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1766 | if (clk->ops->set_rate && | |
71472c0c JH |
1767 | !((clk->ops->round_rate || clk->ops->determine_rate) && |
1768 | clk->ops->recalc_rate)) { | |
1769 | pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", | |
d4d7e3dd | 1770 | __func__, clk->name); |
d1302a36 | 1771 | ret = -EINVAL; |
d4d7e3dd MT |
1772 | goto out; |
1773 | } | |
1774 | ||
1775 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1776 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1777 | __func__, clk->name); | |
d1302a36 | 1778 | ret = -EINVAL; |
d4d7e3dd MT |
1779 | goto out; |
1780 | } | |
1781 | ||
3fa2252b SB |
1782 | if (clk->ops->set_rate_and_parent && |
1783 | !(clk->ops->set_parent && clk->ops->set_rate)) { | |
1784 | pr_warn("%s: %s must implement .set_parent & .set_rate\n", | |
1785 | __func__, clk->name); | |
1786 | ret = -EINVAL; | |
1787 | goto out; | |
1788 | } | |
1789 | ||
b2476490 MT |
1790 | /* throw a WARN if any entries in parent_names are NULL */ |
1791 | for (i = 0; i < clk->num_parents; i++) | |
1792 | WARN(!clk->parent_names[i], | |
1793 | "%s: invalid NULL in %s's .parent_names\n", | |
1794 | __func__, clk->name); | |
1795 | ||
1796 | /* | |
1797 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1798 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1799 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1800 | * must always check for a NULL pointer and try to populate it if | |
1801 | * necessary. | |
1802 | * | |
1803 | * If clk->parents is not NULL we skip this entire block. This allows | |
1804 | * for clock drivers to statically initialize clk->parents. | |
1805 | */ | |
9ca1c5a4 | 1806 | if (clk->num_parents > 1 && !clk->parents) { |
96a7ed90 TF |
1807 | clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *), |
1808 | GFP_KERNEL); | |
b2476490 MT |
1809 | /* |
1810 | * __clk_lookup returns NULL for parents that have not been | |
1811 | * clk_init'd; thus any access to clk->parents[] must check | |
1812 | * for a NULL pointer. We can always perform lazy lookups for | |
1813 | * missing parents later on. | |
1814 | */ | |
1815 | if (clk->parents) | |
1816 | for (i = 0; i < clk->num_parents; i++) | |
1817 | clk->parents[i] = | |
1818 | __clk_lookup(clk->parent_names[i]); | |
1819 | } | |
1820 | ||
1821 | clk->parent = __clk_init_parent(clk); | |
1822 | ||
1823 | /* | |
1824 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1825 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1826 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1827 | * clk list. | |
1828 | * | |
1829 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1830 | * clocks and re-parent any that are children of the clock currently | |
1831 | * being clk_init'd. | |
1832 | */ | |
1833 | if (clk->parent) | |
1834 | hlist_add_head(&clk->child_node, | |
1835 | &clk->parent->children); | |
1836 | else if (clk->flags & CLK_IS_ROOT) | |
1837 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1838 | else | |
1839 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1840 | ||
5279fc40 BB |
1841 | /* |
1842 | * Set clk's accuracy. The preferred method is to use | |
1843 | * .recalc_accuracy. For simple clocks and lazy developers the default | |
1844 | * fallback is to use the parent's accuracy. If a clock doesn't have a | |
1845 | * parent (or is orphaned) then accuracy is set to zero (perfect | |
1846 | * clock). | |
1847 | */ | |
1848 | if (clk->ops->recalc_accuracy) | |
1849 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1850 | __clk_get_accuracy(clk->parent)); | |
1851 | else if (clk->parent) | |
1852 | clk->accuracy = clk->parent->accuracy; | |
1853 | else | |
1854 | clk->accuracy = 0; | |
1855 | ||
b2476490 MT |
1856 | /* |
1857 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1858 | * simple clocks and lazy developers the default fallback is to use the | |
1859 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1860 | * then rate is set to zero. | |
1861 | */ | |
1862 | if (clk->ops->recalc_rate) | |
1863 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1864 | __clk_get_rate(clk->parent)); | |
1865 | else if (clk->parent) | |
1866 | clk->rate = clk->parent->rate; | |
1867 | else | |
1868 | clk->rate = 0; | |
1869 | ||
3a5aec24 | 1870 | clk_debug_register(clk); |
b2476490 MT |
1871 | /* |
1872 | * walk the list of orphan clocks and reparent any that are children of | |
1873 | * this clock | |
1874 | */ | |
b67bfe0d | 1875 | hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { |
12d29886 | 1876 | if (orphan->num_parents && orphan->ops->get_parent) { |
1f61e5f1 MF |
1877 | i = orphan->ops->get_parent(orphan->hw); |
1878 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1879 | __clk_reparent(orphan, clk); | |
1880 | continue; | |
1881 | } | |
1882 | ||
b2476490 MT |
1883 | for (i = 0; i < orphan->num_parents; i++) |
1884 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1885 | __clk_reparent(orphan, clk); | |
1886 | break; | |
1887 | } | |
1f61e5f1 | 1888 | } |
b2476490 MT |
1889 | |
1890 | /* | |
1891 | * optional platform-specific magic | |
1892 | * | |
1893 | * The .init callback is not used by any of the basic clock types, but | |
1894 | * exists for weird hardware that must perform initialization magic. | |
1895 | * Please consider other ways of solving initialization problems before | |
24ee1a08 | 1896 | * using this callback, as its use is discouraged. |
b2476490 MT |
1897 | */ |
1898 | if (clk->ops->init) | |
1899 | clk->ops->init(clk->hw); | |
1900 | ||
fcb0ee6a | 1901 | kref_init(&clk->ref); |
b2476490 | 1902 | out: |
eab89f69 | 1903 | clk_prepare_unlock(); |
b2476490 | 1904 | |
d1302a36 | 1905 | return ret; |
b2476490 MT |
1906 | } |
1907 | ||
0197b3ea SK |
1908 | /** |
1909 | * __clk_register - register a clock and return a cookie. | |
1910 | * | |
1911 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1912 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1913 | * of the struct clk need to be initialized. | |
1914 | * | |
1915 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1916 | * data. | |
1917 | * | |
1918 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1919 | * very large numbers of clocks that need to be statically initialized. It is | |
1920 | * a layering violation to include clk-private.h from any code which implements | |
1921 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
24ee1a08 | 1922 | * separate C file from the logic that implements its operations. Returns 0 |
0197b3ea SK |
1923 | * on success, otherwise an error code. |
1924 | */ | |
1925 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
1926 | { | |
1927 | int ret; | |
1928 | struct clk *clk; | |
1929 | ||
1930 | clk = hw->clk; | |
1931 | clk->name = hw->init->name; | |
1932 | clk->ops = hw->init->ops; | |
1933 | clk->hw = hw; | |
1934 | clk->flags = hw->init->flags; | |
1935 | clk->parent_names = hw->init->parent_names; | |
1936 | clk->num_parents = hw->init->num_parents; | |
ac2df527 SN |
1937 | if (dev && dev->driver) |
1938 | clk->owner = dev->driver->owner; | |
1939 | else | |
1940 | clk->owner = NULL; | |
0197b3ea SK |
1941 | |
1942 | ret = __clk_init(dev, clk); | |
1943 | if (ret) | |
1944 | return ERR_PTR(ret); | |
1945 | ||
1946 | return clk; | |
1947 | } | |
1948 | EXPORT_SYMBOL_GPL(__clk_register); | |
1949 | ||
293ba3b4 SB |
1950 | /** |
1951 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
1952 | * @dev: device that is registering this clock | |
1953 | * @hw: link to hardware-specific clock data | |
1954 | * | |
1955 | * clk_register is the primary interface for populating the clock tree with new | |
1956 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
1957 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
1958 | * rest of the clock API. In the event of an error clk_register will return an | |
1959 | * error code; drivers must test for an error code after calling clk_register. | |
1960 | */ | |
1961 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
b2476490 | 1962 | { |
d1302a36 | 1963 | int i, ret; |
293ba3b4 SB |
1964 | struct clk *clk; |
1965 | ||
1966 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
1967 | if (!clk) { | |
1968 | pr_err("%s: could not allocate clk\n", __func__); | |
1969 | ret = -ENOMEM; | |
1970 | goto fail_out; | |
1971 | } | |
b2476490 | 1972 | |
0197b3ea SK |
1973 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
1974 | if (!clk->name) { | |
1975 | pr_err("%s: could not allocate clk->name\n", __func__); | |
1976 | ret = -ENOMEM; | |
1977 | goto fail_name; | |
1978 | } | |
1979 | clk->ops = hw->init->ops; | |
ac2df527 SN |
1980 | if (dev && dev->driver) |
1981 | clk->owner = dev->driver->owner; | |
b2476490 | 1982 | clk->hw = hw; |
0197b3ea SK |
1983 | clk->flags = hw->init->flags; |
1984 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
1985 | hw->clk = clk; |
1986 | ||
d1302a36 | 1987 | /* allocate local copy in case parent_names is __initdata */ |
96a7ed90 TF |
1988 | clk->parent_names = kcalloc(clk->num_parents, sizeof(char *), |
1989 | GFP_KERNEL); | |
d1302a36 MT |
1990 | |
1991 | if (!clk->parent_names) { | |
1992 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
1993 | ret = -ENOMEM; | |
1994 | goto fail_parent_names; | |
1995 | } | |
1996 | ||
1997 | ||
1998 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea SK |
1999 | for (i = 0; i < clk->num_parents; i++) { |
2000 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], | |
2001 | GFP_KERNEL); | |
d1302a36 MT |
2002 | if (!clk->parent_names[i]) { |
2003 | pr_err("%s: could not copy parent_names\n", __func__); | |
2004 | ret = -ENOMEM; | |
2005 | goto fail_parent_names_copy; | |
2006 | } | |
2007 | } | |
2008 | ||
2009 | ret = __clk_init(dev, clk); | |
2010 | if (!ret) | |
293ba3b4 | 2011 | return clk; |
b2476490 | 2012 | |
d1302a36 MT |
2013 | fail_parent_names_copy: |
2014 | while (--i >= 0) | |
2015 | kfree(clk->parent_names[i]); | |
2016 | kfree(clk->parent_names); | |
2017 | fail_parent_names: | |
0197b3ea SK |
2018 | kfree(clk->name); |
2019 | fail_name: | |
d1302a36 MT |
2020 | kfree(clk); |
2021 | fail_out: | |
2022 | return ERR_PTR(ret); | |
b2476490 MT |
2023 | } |
2024 | EXPORT_SYMBOL_GPL(clk_register); | |
2025 | ||
fcb0ee6a SN |
2026 | /* |
2027 | * Free memory allocated for a clock. | |
2028 | * Caller must hold prepare_lock. | |
2029 | */ | |
2030 | static void __clk_release(struct kref *ref) | |
2031 | { | |
2032 | struct clk *clk = container_of(ref, struct clk, ref); | |
2033 | int i = clk->num_parents; | |
2034 | ||
2035 | kfree(clk->parents); | |
2036 | while (--i >= 0) | |
2037 | kfree(clk->parent_names[i]); | |
2038 | ||
2039 | kfree(clk->parent_names); | |
2040 | kfree(clk->name); | |
2041 | kfree(clk); | |
2042 | } | |
2043 | ||
2044 | /* | |
2045 | * Empty clk_ops for unregistered clocks. These are used temporarily | |
2046 | * after clk_unregister() was called on a clock and until last clock | |
2047 | * consumer calls clk_put() and the struct clk object is freed. | |
2048 | */ | |
2049 | static int clk_nodrv_prepare_enable(struct clk_hw *hw) | |
2050 | { | |
2051 | return -ENXIO; | |
2052 | } | |
2053 | ||
2054 | static void clk_nodrv_disable_unprepare(struct clk_hw *hw) | |
2055 | { | |
2056 | WARN_ON_ONCE(1); | |
2057 | } | |
2058 | ||
2059 | static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, | |
2060 | unsigned long parent_rate) | |
2061 | { | |
2062 | return -ENXIO; | |
2063 | } | |
2064 | ||
2065 | static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) | |
2066 | { | |
2067 | return -ENXIO; | |
2068 | } | |
2069 | ||
2070 | static const struct clk_ops clk_nodrv_ops = { | |
2071 | .enable = clk_nodrv_prepare_enable, | |
2072 | .disable = clk_nodrv_disable_unprepare, | |
2073 | .prepare = clk_nodrv_prepare_enable, | |
2074 | .unprepare = clk_nodrv_disable_unprepare, | |
2075 | .set_rate = clk_nodrv_set_rate, | |
2076 | .set_parent = clk_nodrv_set_parent, | |
2077 | }; | |
2078 | ||
1df5c939 MB |
2079 | /** |
2080 | * clk_unregister - unregister a currently registered clock | |
2081 | * @clk: clock to unregister | |
1df5c939 | 2082 | */ |
fcb0ee6a SN |
2083 | void clk_unregister(struct clk *clk) |
2084 | { | |
2085 | unsigned long flags; | |
2086 | ||
2087 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) | |
2088 | return; | |
2089 | ||
2090 | clk_prepare_lock(); | |
2091 | ||
2092 | if (clk->ops == &clk_nodrv_ops) { | |
2093 | pr_err("%s: unregistered clock: %s\n", __func__, clk->name); | |
2094 | goto out; | |
2095 | } | |
2096 | /* | |
2097 | * Assign empty clock ops for consumers that might still hold | |
2098 | * a reference to this clock. | |
2099 | */ | |
2100 | flags = clk_enable_lock(); | |
2101 | clk->ops = &clk_nodrv_ops; | |
2102 | clk_enable_unlock(flags); | |
2103 | ||
2104 | if (!hlist_empty(&clk->children)) { | |
2105 | struct clk *child; | |
874f224c | 2106 | struct hlist_node *t; |
fcb0ee6a SN |
2107 | |
2108 | /* Reparent all children to the orphan list. */ | |
874f224c | 2109 | hlist_for_each_entry_safe(child, t, &clk->children, child_node) |
fcb0ee6a SN |
2110 | clk_set_parent(child, NULL); |
2111 | } | |
2112 | ||
2113 | clk_debug_unregister(clk); | |
2114 | ||
2115 | hlist_del_init(&clk->child_node); | |
2116 | ||
2117 | if (clk->prepare_count) | |
2118 | pr_warn("%s: unregistering prepared clock: %s\n", | |
2119 | __func__, clk->name); | |
2120 | ||
2121 | kref_put(&clk->ref, __clk_release); | |
2122 | out: | |
2123 | clk_prepare_unlock(); | |
2124 | } | |
1df5c939 MB |
2125 | EXPORT_SYMBOL_GPL(clk_unregister); |
2126 | ||
46c8773a SB |
2127 | static void devm_clk_release(struct device *dev, void *res) |
2128 | { | |
293ba3b4 | 2129 | clk_unregister(*(struct clk **)res); |
46c8773a SB |
2130 | } |
2131 | ||
2132 | /** | |
2133 | * devm_clk_register - resource managed clk_register() | |
2134 | * @dev: device that is registering this clock | |
2135 | * @hw: link to hardware-specific clock data | |
2136 | * | |
2137 | * Managed clk_register(). Clocks returned from this function are | |
2138 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
2139 | * more information. | |
2140 | */ | |
2141 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
2142 | { | |
2143 | struct clk *clk; | |
293ba3b4 | 2144 | struct clk **clkp; |
46c8773a | 2145 | |
293ba3b4 SB |
2146 | clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL); |
2147 | if (!clkp) | |
46c8773a SB |
2148 | return ERR_PTR(-ENOMEM); |
2149 | ||
293ba3b4 SB |
2150 | clk = clk_register(dev, hw); |
2151 | if (!IS_ERR(clk)) { | |
2152 | *clkp = clk; | |
2153 | devres_add(dev, clkp); | |
46c8773a | 2154 | } else { |
293ba3b4 | 2155 | devres_free(clkp); |
46c8773a SB |
2156 | } |
2157 | ||
2158 | return clk; | |
2159 | } | |
2160 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
2161 | ||
2162 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
2163 | { | |
2164 | struct clk *c = res; | |
2165 | if (WARN_ON(!c)) | |
2166 | return 0; | |
2167 | return c == data; | |
2168 | } | |
2169 | ||
2170 | /** | |
2171 | * devm_clk_unregister - resource managed clk_unregister() | |
2172 | * @clk: clock to unregister | |
2173 | * | |
2174 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
2175 | * this function will not need to be called and the resource management | |
2176 | * code will ensure that the resource is freed. | |
2177 | */ | |
2178 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
2179 | { | |
2180 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
2181 | } | |
2182 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
2183 | ||
ac2df527 SN |
2184 | /* |
2185 | * clkdev helpers | |
2186 | */ | |
2187 | int __clk_get(struct clk *clk) | |
2188 | { | |
00efcb1c SN |
2189 | if (clk) { |
2190 | if (!try_module_get(clk->owner)) | |
2191 | return 0; | |
ac2df527 | 2192 | |
00efcb1c SN |
2193 | kref_get(&clk->ref); |
2194 | } | |
ac2df527 SN |
2195 | return 1; |
2196 | } | |
2197 | ||
2198 | void __clk_put(struct clk *clk) | |
2199 | { | |
00efcb1c | 2200 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) |
ac2df527 SN |
2201 | return; |
2202 | ||
fcb0ee6a SN |
2203 | clk_prepare_lock(); |
2204 | kref_put(&clk->ref, __clk_release); | |
2205 | clk_prepare_unlock(); | |
2206 | ||
00efcb1c | 2207 | module_put(clk->owner); |
ac2df527 SN |
2208 | } |
2209 | ||
b2476490 MT |
2210 | /*** clk rate change notifiers ***/ |
2211 | ||
2212 | /** | |
2213 | * clk_notifier_register - add a clk rate change notifier | |
2214 | * @clk: struct clk * to watch | |
2215 | * @nb: struct notifier_block * with callback info | |
2216 | * | |
2217 | * Request notification when clk's rate changes. This uses an SRCU | |
2218 | * notifier because we want it to block and notifier unregistrations are | |
2219 | * uncommon. The callbacks associated with the notifier must not | |
2220 | * re-enter into the clk framework by calling any top-level clk APIs; | |
2221 | * this will cause a nested prepare_lock mutex. | |
2222 | * | |
5324fda7 SB |
2223 | * In all notification cases cases (pre, post and abort rate change) the |
2224 | * original clock rate is passed to the callback via struct | |
2225 | * clk_notifier_data.old_rate and the new frequency is passed via struct | |
b2476490 MT |
2226 | * clk_notifier_data.new_rate. |
2227 | * | |
b2476490 MT |
2228 | * clk_notifier_register() must be called from non-atomic context. |
2229 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
2230 | * allocation failure; otherwise, passes along the return value of | |
2231 | * srcu_notifier_chain_register(). | |
2232 | */ | |
2233 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
2234 | { | |
2235 | struct clk_notifier *cn; | |
2236 | int ret = -ENOMEM; | |
2237 | ||
2238 | if (!clk || !nb) | |
2239 | return -EINVAL; | |
2240 | ||
eab89f69 | 2241 | clk_prepare_lock(); |
b2476490 MT |
2242 | |
2243 | /* search the list of notifiers for this clk */ | |
2244 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2245 | if (cn->clk == clk) | |
2246 | break; | |
2247 | ||
2248 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
2249 | if (cn->clk != clk) { | |
2250 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
2251 | if (!cn) | |
2252 | goto out; | |
2253 | ||
2254 | cn->clk = clk; | |
2255 | srcu_init_notifier_head(&cn->notifier_head); | |
2256 | ||
2257 | list_add(&cn->node, &clk_notifier_list); | |
2258 | } | |
2259 | ||
2260 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
2261 | ||
2262 | clk->notifier_count++; | |
2263 | ||
2264 | out: | |
eab89f69 | 2265 | clk_prepare_unlock(); |
b2476490 MT |
2266 | |
2267 | return ret; | |
2268 | } | |
2269 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
2270 | ||
2271 | /** | |
2272 | * clk_notifier_unregister - remove a clk rate change notifier | |
2273 | * @clk: struct clk * | |
2274 | * @nb: struct notifier_block * with callback info | |
2275 | * | |
2276 | * Request no further notification for changes to 'clk' and frees memory | |
2277 | * allocated in clk_notifier_register. | |
2278 | * | |
2279 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
2280 | * along the return value of srcu_notifier_chain_unregister(). | |
2281 | */ | |
2282 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
2283 | { | |
2284 | struct clk_notifier *cn = NULL; | |
2285 | int ret = -EINVAL; | |
2286 | ||
2287 | if (!clk || !nb) | |
2288 | return -EINVAL; | |
2289 | ||
eab89f69 | 2290 | clk_prepare_lock(); |
b2476490 MT |
2291 | |
2292 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2293 | if (cn->clk == clk) | |
2294 | break; | |
2295 | ||
2296 | if (cn->clk == clk) { | |
2297 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
2298 | ||
2299 | clk->notifier_count--; | |
2300 | ||
2301 | /* XXX the notifier code should handle this better */ | |
2302 | if (!cn->notifier_head.head) { | |
2303 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
72b5322f | 2304 | list_del(&cn->node); |
b2476490 MT |
2305 | kfree(cn); |
2306 | } | |
2307 | ||
2308 | } else { | |
2309 | ret = -ENOENT; | |
2310 | } | |
2311 | ||
eab89f69 | 2312 | clk_prepare_unlock(); |
b2476490 MT |
2313 | |
2314 | return ret; | |
2315 | } | |
2316 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
2317 | |
2318 | #ifdef CONFIG_OF | |
2319 | /** | |
2320 | * struct of_clk_provider - Clock provider registration structure | |
2321 | * @link: Entry in global list of clock providers | |
2322 | * @node: Pointer to device tree node of clock provider | |
2323 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
2324 | * given clock specifier | |
2325 | * @data: context pointer to be passed into @get callback | |
2326 | */ | |
2327 | struct of_clk_provider { | |
2328 | struct list_head link; | |
2329 | ||
2330 | struct device_node *node; | |
2331 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
2332 | void *data; | |
2333 | }; | |
2334 | ||
f2f6c255 PG |
2335 | static const struct of_device_id __clk_of_table_sentinel |
2336 | __used __section(__clk_of_table_end); | |
2337 | ||
766e6a4e | 2338 | static LIST_HEAD(of_clk_providers); |
d6782c26 SN |
2339 | static DEFINE_MUTEX(of_clk_mutex); |
2340 | ||
2341 | /* of_clk_provider list locking helpers */ | |
2342 | void of_clk_lock(void) | |
2343 | { | |
2344 | mutex_lock(&of_clk_mutex); | |
2345 | } | |
2346 | ||
2347 | void of_clk_unlock(void) | |
2348 | { | |
2349 | mutex_unlock(&of_clk_mutex); | |
2350 | } | |
766e6a4e GL |
2351 | |
2352 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
2353 | void *data) | |
2354 | { | |
2355 | return data; | |
2356 | } | |
2357 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
2358 | ||
494bfec9 SG |
2359 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
2360 | { | |
2361 | struct clk_onecell_data *clk_data = data; | |
2362 | unsigned int idx = clkspec->args[0]; | |
2363 | ||
2364 | if (idx >= clk_data->clk_num) { | |
2365 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
2366 | return ERR_PTR(-EINVAL); | |
2367 | } | |
2368 | ||
2369 | return clk_data->clks[idx]; | |
2370 | } | |
2371 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
2372 | ||
766e6a4e GL |
2373 | /** |
2374 | * of_clk_add_provider() - Register a clock provider for a node | |
2375 | * @np: Device node pointer associated with clock provider | |
2376 | * @clk_src_get: callback for decoding clock | |
2377 | * @data: context pointer for @clk_src_get callback. | |
2378 | */ | |
2379 | int of_clk_add_provider(struct device_node *np, | |
2380 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
2381 | void *data), | |
2382 | void *data) | |
2383 | { | |
2384 | struct of_clk_provider *cp; | |
2385 | ||
2386 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
2387 | if (!cp) | |
2388 | return -ENOMEM; | |
2389 | ||
2390 | cp->node = of_node_get(np); | |
2391 | cp->data = data; | |
2392 | cp->get = clk_src_get; | |
2393 | ||
d6782c26 | 2394 | mutex_lock(&of_clk_mutex); |
766e6a4e | 2395 | list_add(&cp->link, &of_clk_providers); |
d6782c26 | 2396 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2397 | pr_debug("Added clock from %s\n", np->full_name); |
2398 | ||
2399 | return 0; | |
2400 | } | |
2401 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
2402 | ||
2403 | /** | |
2404 | * of_clk_del_provider() - Remove a previously registered clock provider | |
2405 | * @np: Device node pointer associated with clock provider | |
2406 | */ | |
2407 | void of_clk_del_provider(struct device_node *np) | |
2408 | { | |
2409 | struct of_clk_provider *cp; | |
2410 | ||
d6782c26 | 2411 | mutex_lock(&of_clk_mutex); |
766e6a4e GL |
2412 | list_for_each_entry(cp, &of_clk_providers, link) { |
2413 | if (cp->node == np) { | |
2414 | list_del(&cp->link); | |
2415 | of_node_put(cp->node); | |
2416 | kfree(cp); | |
2417 | break; | |
2418 | } | |
2419 | } | |
d6782c26 | 2420 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2421 | } |
2422 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
2423 | ||
d6782c26 | 2424 | struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) |
766e6a4e GL |
2425 | { |
2426 | struct of_clk_provider *provider; | |
a34cd466 | 2427 | struct clk *clk = ERR_PTR(-EPROBE_DEFER); |
766e6a4e GL |
2428 | |
2429 | /* Check if we have such a provider in our array */ | |
766e6a4e GL |
2430 | list_for_each_entry(provider, &of_clk_providers, link) { |
2431 | if (provider->node == clkspec->np) | |
2432 | clk = provider->get(clkspec, provider->data); | |
2433 | if (!IS_ERR(clk)) | |
2434 | break; | |
2435 | } | |
d6782c26 SN |
2436 | |
2437 | return clk; | |
2438 | } | |
2439 | ||
2440 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
2441 | { | |
2442 | struct clk *clk; | |
2443 | ||
2444 | mutex_lock(&of_clk_mutex); | |
2445 | clk = __of_clk_get_from_provider(clkspec); | |
2446 | mutex_unlock(&of_clk_mutex); | |
766e6a4e GL |
2447 | |
2448 | return clk; | |
2449 | } | |
2450 | ||
f6102742 MT |
2451 | int of_clk_get_parent_count(struct device_node *np) |
2452 | { | |
2453 | return of_count_phandle_with_args(np, "clocks", "#clock-cells"); | |
2454 | } | |
2455 | EXPORT_SYMBOL_GPL(of_clk_get_parent_count); | |
2456 | ||
766e6a4e GL |
2457 | const char *of_clk_get_parent_name(struct device_node *np, int index) |
2458 | { | |
2459 | struct of_phandle_args clkspec; | |
7a0fc1a3 | 2460 | struct property *prop; |
766e6a4e | 2461 | const char *clk_name; |
7a0fc1a3 BD |
2462 | const __be32 *vp; |
2463 | u32 pv; | |
766e6a4e | 2464 | int rc; |
7a0fc1a3 | 2465 | int count; |
766e6a4e GL |
2466 | |
2467 | if (index < 0) | |
2468 | return NULL; | |
2469 | ||
2470 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
2471 | &clkspec); | |
2472 | if (rc) | |
2473 | return NULL; | |
2474 | ||
7a0fc1a3 BD |
2475 | index = clkspec.args_count ? clkspec.args[0] : 0; |
2476 | count = 0; | |
2477 | ||
2478 | /* if there is an indices property, use it to transfer the index | |
2479 | * specified into an array offset for the clock-output-names property. | |
2480 | */ | |
2481 | of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) { | |
2482 | if (index == pv) { | |
2483 | index = count; | |
2484 | break; | |
2485 | } | |
2486 | count++; | |
2487 | } | |
2488 | ||
766e6a4e | 2489 | if (of_property_read_string_index(clkspec.np, "clock-output-names", |
7a0fc1a3 | 2490 | index, |
766e6a4e GL |
2491 | &clk_name) < 0) |
2492 | clk_name = clkspec.np->name; | |
2493 | ||
2494 | of_node_put(clkspec.np); | |
2495 | return clk_name; | |
2496 | } | |
2497 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
2498 | ||
1771b10d GC |
2499 | struct clock_provider { |
2500 | of_clk_init_cb_t clk_init_cb; | |
2501 | struct device_node *np; | |
2502 | struct list_head node; | |
2503 | }; | |
2504 | ||
2505 | static LIST_HEAD(clk_provider_list); | |
2506 | ||
2507 | /* | |
2508 | * This function looks for a parent clock. If there is one, then it | |
2509 | * checks that the provider for this parent clock was initialized, in | |
2510 | * this case the parent clock will be ready. | |
2511 | */ | |
2512 | static int parent_ready(struct device_node *np) | |
2513 | { | |
2514 | int i = 0; | |
2515 | ||
2516 | while (true) { | |
2517 | struct clk *clk = of_clk_get(np, i); | |
2518 | ||
2519 | /* this parent is ready we can check the next one */ | |
2520 | if (!IS_ERR(clk)) { | |
2521 | clk_put(clk); | |
2522 | i++; | |
2523 | continue; | |
2524 | } | |
2525 | ||
2526 | /* at least one parent is not ready, we exit now */ | |
2527 | if (PTR_ERR(clk) == -EPROBE_DEFER) | |
2528 | return 0; | |
2529 | ||
2530 | /* | |
2531 | * Here we make assumption that the device tree is | |
2532 | * written correctly. So an error means that there is | |
2533 | * no more parent. As we didn't exit yet, then the | |
2534 | * previous parent are ready. If there is no clock | |
2535 | * parent, no need to wait for them, then we can | |
2536 | * consider their absence as being ready | |
2537 | */ | |
2538 | return 1; | |
2539 | } | |
2540 | } | |
2541 | ||
766e6a4e GL |
2542 | /** |
2543 | * of_clk_init() - Scan and init clock providers from the DT | |
2544 | * @matches: array of compatible values and init functions for providers. | |
2545 | * | |
1771b10d | 2546 | * This function scans the device tree for matching clock providers |
e5ca8fb4 | 2547 | * and calls their initialization functions. It also does it by trying |
1771b10d | 2548 | * to follow the dependencies. |
766e6a4e GL |
2549 | */ |
2550 | void __init of_clk_init(const struct of_device_id *matches) | |
2551 | { | |
7f7ed584 | 2552 | const struct of_device_id *match; |
766e6a4e | 2553 | struct device_node *np; |
1771b10d GC |
2554 | struct clock_provider *clk_provider, *next; |
2555 | bool is_init_done; | |
2556 | bool force = false; | |
766e6a4e | 2557 | |
f2f6c255 | 2558 | if (!matches) |
819b4861 | 2559 | matches = &__clk_of_table; |
f2f6c255 | 2560 | |
1771b10d | 2561 | /* First prepare the list of the clocks providers */ |
7f7ed584 | 2562 | for_each_matching_node_and_match(np, matches, &match) { |
1771b10d GC |
2563 | struct clock_provider *parent = |
2564 | kzalloc(sizeof(struct clock_provider), GFP_KERNEL); | |
2565 | ||
2566 | parent->clk_init_cb = match->data; | |
2567 | parent->np = np; | |
3f6d439f | 2568 | list_add_tail(&parent->node, &clk_provider_list); |
1771b10d GC |
2569 | } |
2570 | ||
2571 | while (!list_empty(&clk_provider_list)) { | |
2572 | is_init_done = false; | |
2573 | list_for_each_entry_safe(clk_provider, next, | |
2574 | &clk_provider_list, node) { | |
2575 | if (force || parent_ready(clk_provider->np)) { | |
2576 | clk_provider->clk_init_cb(clk_provider->np); | |
2577 | list_del(&clk_provider->node); | |
2578 | kfree(clk_provider); | |
2579 | is_init_done = true; | |
2580 | } | |
2581 | } | |
2582 | ||
2583 | /* | |
e5ca8fb4 | 2584 | * We didn't manage to initialize any of the |
1771b10d GC |
2585 | * remaining providers during the last loop, so now we |
2586 | * initialize all the remaining ones unconditionally | |
2587 | * in case the clock parent was not mandatory | |
2588 | */ | |
2589 | if (!is_init_done) | |
2590 | force = true; | |
2591 | ||
766e6a4e GL |
2592 | } |
2593 | } | |
2594 | #endif |