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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> |
b2476490 MT |
21 | |
22 | static DEFINE_SPINLOCK(enable_lock); | |
23 | static DEFINE_MUTEX(prepare_lock); | |
24 | ||
25 | static HLIST_HEAD(clk_root_list); | |
26 | static HLIST_HEAD(clk_orphan_list); | |
27 | static LIST_HEAD(clk_notifier_list); | |
28 | ||
29 | /*** debugfs support ***/ | |
30 | ||
31 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
32 | #include <linux/debugfs.h> | |
33 | ||
34 | static struct dentry *rootdir; | |
35 | static struct dentry *orphandir; | |
36 | static int inited = 0; | |
37 | ||
38 | /* caller must hold prepare_lock */ | |
39 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) | |
40 | { | |
41 | struct dentry *d; | |
42 | int ret = -ENOMEM; | |
43 | ||
44 | if (!clk || !pdentry) { | |
45 | ret = -EINVAL; | |
46 | goto out; | |
47 | } | |
48 | ||
49 | d = debugfs_create_dir(clk->name, pdentry); | |
50 | if (!d) | |
51 | goto out; | |
52 | ||
53 | clk->dentry = d; | |
54 | ||
55 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, | |
56 | (u32 *)&clk->rate); | |
57 | if (!d) | |
58 | goto err_out; | |
59 | ||
60 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, | |
61 | (u32 *)&clk->flags); | |
62 | if (!d) | |
63 | goto err_out; | |
64 | ||
65 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, | |
66 | (u32 *)&clk->prepare_count); | |
67 | if (!d) | |
68 | goto err_out; | |
69 | ||
70 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, | |
71 | (u32 *)&clk->enable_count); | |
72 | if (!d) | |
73 | goto err_out; | |
74 | ||
75 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, | |
76 | (u32 *)&clk->notifier_count); | |
77 | if (!d) | |
78 | goto err_out; | |
79 | ||
80 | ret = 0; | |
81 | goto out; | |
82 | ||
83 | err_out: | |
84 | debugfs_remove(clk->dentry); | |
85 | out: | |
86 | return ret; | |
87 | } | |
88 | ||
89 | /* caller must hold prepare_lock */ | |
90 | static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry) | |
91 | { | |
92 | struct clk *child; | |
93 | struct hlist_node *tmp; | |
94 | int ret = -EINVAL;; | |
95 | ||
96 | if (!clk || !pdentry) | |
97 | goto out; | |
98 | ||
99 | ret = clk_debug_create_one(clk, pdentry); | |
100 | ||
101 | if (ret) | |
102 | goto out; | |
103 | ||
104 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
105 | clk_debug_create_subtree(child, clk->dentry); | |
106 | ||
107 | ret = 0; | |
108 | out: | |
109 | return ret; | |
110 | } | |
111 | ||
112 | /** | |
113 | * clk_debug_register - add a clk node to the debugfs clk tree | |
114 | * @clk: the clk being added to the debugfs clk tree | |
115 | * | |
116 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been | |
117 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
118 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
119 | * | |
120 | * Caller must hold prepare_lock. Only clk_init calls this function (so | |
121 | * far) so this is taken care. | |
122 | */ | |
123 | static int clk_debug_register(struct clk *clk) | |
124 | { | |
125 | struct clk *parent; | |
126 | struct dentry *pdentry; | |
127 | int ret = 0; | |
128 | ||
129 | if (!inited) | |
130 | goto out; | |
131 | ||
132 | parent = clk->parent; | |
133 | ||
134 | /* | |
135 | * Check to see if a clk is a root clk. Also check that it is | |
136 | * safe to add this clk to debugfs | |
137 | */ | |
138 | if (!parent) | |
139 | if (clk->flags & CLK_IS_ROOT) | |
140 | pdentry = rootdir; | |
141 | else | |
142 | pdentry = orphandir; | |
143 | else | |
144 | if (parent->dentry) | |
145 | pdentry = parent->dentry; | |
146 | else | |
147 | goto out; | |
148 | ||
149 | ret = clk_debug_create_subtree(clk, pdentry); | |
150 | ||
151 | out: | |
152 | return ret; | |
153 | } | |
154 | ||
155 | /** | |
156 | * clk_debug_init - lazily create the debugfs clk tree visualization | |
157 | * | |
158 | * clks are often initialized very early during boot before memory can | |
159 | * be dynamically allocated and well before debugfs is setup. | |
160 | * clk_debug_init walks the clk tree hierarchy while holding | |
161 | * prepare_lock and creates the topology as part of a late_initcall, | |
162 | * thus insuring that clks initialized very early will still be | |
163 | * represented in the debugfs clk tree. This function should only be | |
164 | * called once at boot-time, and all other clks added dynamically will | |
165 | * be done so with clk_debug_register. | |
166 | */ | |
167 | static int __init clk_debug_init(void) | |
168 | { | |
169 | struct clk *clk; | |
170 | struct hlist_node *tmp; | |
171 | ||
172 | rootdir = debugfs_create_dir("clk", NULL); | |
173 | ||
174 | if (!rootdir) | |
175 | return -ENOMEM; | |
176 | ||
177 | orphandir = debugfs_create_dir("orphans", rootdir); | |
178 | ||
179 | if (!orphandir) | |
180 | return -ENOMEM; | |
181 | ||
182 | mutex_lock(&prepare_lock); | |
183 | ||
184 | hlist_for_each_entry(clk, tmp, &clk_root_list, child_node) | |
185 | clk_debug_create_subtree(clk, rootdir); | |
186 | ||
187 | hlist_for_each_entry(clk, tmp, &clk_orphan_list, child_node) | |
188 | clk_debug_create_subtree(clk, orphandir); | |
189 | ||
190 | inited = 1; | |
191 | ||
192 | mutex_unlock(&prepare_lock); | |
193 | ||
194 | return 0; | |
195 | } | |
196 | late_initcall(clk_debug_init); | |
197 | #else | |
198 | static inline int clk_debug_register(struct clk *clk) { return 0; } | |
70d347e6 | 199 | #endif |
b2476490 | 200 | |
b2476490 MT |
201 | /* caller must hold prepare_lock */ |
202 | static void clk_disable_unused_subtree(struct clk *clk) | |
203 | { | |
204 | struct clk *child; | |
205 | struct hlist_node *tmp; | |
206 | unsigned long flags; | |
207 | ||
208 | if (!clk) | |
209 | goto out; | |
210 | ||
211 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
212 | clk_disable_unused_subtree(child); | |
213 | ||
214 | spin_lock_irqsave(&enable_lock, flags); | |
215 | ||
216 | if (clk->enable_count) | |
217 | goto unlock_out; | |
218 | ||
219 | if (clk->flags & CLK_IGNORE_UNUSED) | |
220 | goto unlock_out; | |
221 | ||
222 | if (__clk_is_enabled(clk) && clk->ops->disable) | |
223 | clk->ops->disable(clk->hw); | |
224 | ||
225 | unlock_out: | |
226 | spin_unlock_irqrestore(&enable_lock, flags); | |
227 | ||
228 | out: | |
229 | return; | |
230 | } | |
231 | ||
232 | static int clk_disable_unused(void) | |
233 | { | |
234 | struct clk *clk; | |
235 | struct hlist_node *tmp; | |
236 | ||
237 | mutex_lock(&prepare_lock); | |
238 | ||
239 | hlist_for_each_entry(clk, tmp, &clk_root_list, child_node) | |
240 | clk_disable_unused_subtree(clk); | |
241 | ||
242 | hlist_for_each_entry(clk, tmp, &clk_orphan_list, child_node) | |
243 | clk_disable_unused_subtree(clk); | |
244 | ||
245 | mutex_unlock(&prepare_lock); | |
246 | ||
247 | return 0; | |
248 | } | |
249 | late_initcall(clk_disable_unused); | |
b2476490 MT |
250 | |
251 | /*** helper functions ***/ | |
252 | ||
253 | inline const char *__clk_get_name(struct clk *clk) | |
254 | { | |
255 | return !clk ? NULL : clk->name; | |
256 | } | |
257 | ||
258 | inline struct clk_hw *__clk_get_hw(struct clk *clk) | |
259 | { | |
260 | return !clk ? NULL : clk->hw; | |
261 | } | |
262 | ||
263 | inline u8 __clk_get_num_parents(struct clk *clk) | |
264 | { | |
2ac6b1f5 | 265 | return !clk ? 0 : clk->num_parents; |
b2476490 MT |
266 | } |
267 | ||
268 | inline struct clk *__clk_get_parent(struct clk *clk) | |
269 | { | |
270 | return !clk ? NULL : clk->parent; | |
271 | } | |
272 | ||
2ac6b1f5 | 273 | inline unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 274 | { |
2ac6b1f5 | 275 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
276 | } |
277 | ||
2ac6b1f5 | 278 | inline unsigned int __clk_get_prepare_count(struct clk *clk) |
b2476490 | 279 | { |
2ac6b1f5 | 280 | return !clk ? 0 : clk->prepare_count; |
b2476490 MT |
281 | } |
282 | ||
283 | unsigned long __clk_get_rate(struct clk *clk) | |
284 | { | |
285 | unsigned long ret; | |
286 | ||
287 | if (!clk) { | |
34e44fe8 | 288 | ret = 0; |
b2476490 MT |
289 | goto out; |
290 | } | |
291 | ||
292 | ret = clk->rate; | |
293 | ||
294 | if (clk->flags & CLK_IS_ROOT) | |
295 | goto out; | |
296 | ||
297 | if (!clk->parent) | |
34e44fe8 | 298 | ret = 0; |
b2476490 MT |
299 | |
300 | out: | |
301 | return ret; | |
302 | } | |
303 | ||
304 | inline unsigned long __clk_get_flags(struct clk *clk) | |
305 | { | |
2ac6b1f5 | 306 | return !clk ? 0 : clk->flags; |
b2476490 MT |
307 | } |
308 | ||
2ac6b1f5 | 309 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
310 | { |
311 | int ret; | |
312 | ||
313 | if (!clk) | |
2ac6b1f5 | 314 | return false; |
b2476490 MT |
315 | |
316 | /* | |
317 | * .is_enabled is only mandatory for clocks that gate | |
318 | * fall back to software usage counter if .is_enabled is missing | |
319 | */ | |
320 | if (!clk->ops->is_enabled) { | |
321 | ret = clk->enable_count ? 1 : 0; | |
322 | goto out; | |
323 | } | |
324 | ||
325 | ret = clk->ops->is_enabled(clk->hw); | |
326 | out: | |
2ac6b1f5 | 327 | return !!ret; |
b2476490 MT |
328 | } |
329 | ||
330 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
331 | { | |
332 | struct clk *child; | |
333 | struct clk *ret; | |
334 | struct hlist_node *tmp; | |
335 | ||
336 | if (!strcmp(clk->name, name)) | |
337 | return clk; | |
338 | ||
339 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
340 | ret = __clk_lookup_subtree(name, child); | |
341 | if (ret) | |
342 | return ret; | |
343 | } | |
344 | ||
345 | return NULL; | |
346 | } | |
347 | ||
348 | struct clk *__clk_lookup(const char *name) | |
349 | { | |
350 | struct clk *root_clk; | |
351 | struct clk *ret; | |
352 | struct hlist_node *tmp; | |
353 | ||
354 | if (!name) | |
355 | return NULL; | |
356 | ||
357 | /* search the 'proper' clk tree first */ | |
358 | hlist_for_each_entry(root_clk, tmp, &clk_root_list, child_node) { | |
359 | ret = __clk_lookup_subtree(name, root_clk); | |
360 | if (ret) | |
361 | return ret; | |
362 | } | |
363 | ||
364 | /* if not found, then search the orphan tree */ | |
365 | hlist_for_each_entry(root_clk, tmp, &clk_orphan_list, child_node) { | |
366 | ret = __clk_lookup_subtree(name, root_clk); | |
367 | if (ret) | |
368 | return ret; | |
369 | } | |
370 | ||
371 | return NULL; | |
372 | } | |
373 | ||
374 | /*** clk api ***/ | |
375 | ||
376 | void __clk_unprepare(struct clk *clk) | |
377 | { | |
378 | if (!clk) | |
379 | return; | |
380 | ||
381 | if (WARN_ON(clk->prepare_count == 0)) | |
382 | return; | |
383 | ||
384 | if (--clk->prepare_count > 0) | |
385 | return; | |
386 | ||
387 | WARN_ON(clk->enable_count > 0); | |
388 | ||
389 | if (clk->ops->unprepare) | |
390 | clk->ops->unprepare(clk->hw); | |
391 | ||
392 | __clk_unprepare(clk->parent); | |
393 | } | |
394 | ||
395 | /** | |
396 | * clk_unprepare - undo preparation of a clock source | |
397 | * @clk: the clk being unprepare | |
398 | * | |
399 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
400 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
401 | * if the operation may sleep. One example is a clk which is accessed over | |
402 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
403 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
404 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
405 | */ | |
406 | void clk_unprepare(struct clk *clk) | |
407 | { | |
408 | mutex_lock(&prepare_lock); | |
409 | __clk_unprepare(clk); | |
410 | mutex_unlock(&prepare_lock); | |
411 | } | |
412 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
413 | ||
414 | int __clk_prepare(struct clk *clk) | |
415 | { | |
416 | int ret = 0; | |
417 | ||
418 | if (!clk) | |
419 | return 0; | |
420 | ||
421 | if (clk->prepare_count == 0) { | |
422 | ret = __clk_prepare(clk->parent); | |
423 | if (ret) | |
424 | return ret; | |
425 | ||
426 | if (clk->ops->prepare) { | |
427 | ret = clk->ops->prepare(clk->hw); | |
428 | if (ret) { | |
429 | __clk_unprepare(clk->parent); | |
430 | return ret; | |
431 | } | |
432 | } | |
433 | } | |
434 | ||
435 | clk->prepare_count++; | |
436 | ||
437 | return 0; | |
438 | } | |
439 | ||
440 | /** | |
441 | * clk_prepare - prepare a clock source | |
442 | * @clk: the clk being prepared | |
443 | * | |
444 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
445 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
446 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
447 | * the complex case a clk ungate operation may require a fast and a slow part. | |
448 | * It is this reason that clk_prepare and clk_enable are not mutually | |
449 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
450 | * Returns 0 on success, -EERROR otherwise. | |
451 | */ | |
452 | int clk_prepare(struct clk *clk) | |
453 | { | |
454 | int ret; | |
455 | ||
456 | mutex_lock(&prepare_lock); | |
457 | ret = __clk_prepare(clk); | |
458 | mutex_unlock(&prepare_lock); | |
459 | ||
460 | return ret; | |
461 | } | |
462 | EXPORT_SYMBOL_GPL(clk_prepare); | |
463 | ||
464 | static void __clk_disable(struct clk *clk) | |
465 | { | |
466 | if (!clk) | |
467 | return; | |
468 | ||
e47c6a34 FW |
469 | if (WARN_ON(IS_ERR(clk))) |
470 | return; | |
471 | ||
b2476490 MT |
472 | if (WARN_ON(clk->enable_count == 0)) |
473 | return; | |
474 | ||
475 | if (--clk->enable_count > 0) | |
476 | return; | |
477 | ||
478 | if (clk->ops->disable) | |
479 | clk->ops->disable(clk->hw); | |
480 | ||
481 | __clk_disable(clk->parent); | |
482 | } | |
483 | ||
484 | /** | |
485 | * clk_disable - gate a clock | |
486 | * @clk: the clk being gated | |
487 | * | |
488 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
489 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
490 | * clk if the operation is fast and will never sleep. One example is a | |
491 | * SoC-internal clk which is controlled via simple register writes. In the | |
492 | * complex case a clk gate operation may require a fast and a slow part. It is | |
493 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
494 | * In fact clk_disable must be called before clk_unprepare. | |
495 | */ | |
496 | void clk_disable(struct clk *clk) | |
497 | { | |
498 | unsigned long flags; | |
499 | ||
500 | spin_lock_irqsave(&enable_lock, flags); | |
501 | __clk_disable(clk); | |
502 | spin_unlock_irqrestore(&enable_lock, flags); | |
503 | } | |
504 | EXPORT_SYMBOL_GPL(clk_disable); | |
505 | ||
506 | static int __clk_enable(struct clk *clk) | |
507 | { | |
508 | int ret = 0; | |
509 | ||
510 | if (!clk) | |
511 | return 0; | |
512 | ||
513 | if (WARN_ON(clk->prepare_count == 0)) | |
514 | return -ESHUTDOWN; | |
515 | ||
516 | if (clk->enable_count == 0) { | |
517 | ret = __clk_enable(clk->parent); | |
518 | ||
519 | if (ret) | |
520 | return ret; | |
521 | ||
522 | if (clk->ops->enable) { | |
523 | ret = clk->ops->enable(clk->hw); | |
524 | if (ret) { | |
525 | __clk_disable(clk->parent); | |
526 | return ret; | |
527 | } | |
528 | } | |
529 | } | |
530 | ||
531 | clk->enable_count++; | |
532 | return 0; | |
533 | } | |
534 | ||
535 | /** | |
536 | * clk_enable - ungate a clock | |
537 | * @clk: the clk being ungated | |
538 | * | |
539 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
540 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
541 | * if the operation will never sleep. One example is a SoC-internal clk which | |
542 | * is controlled via simple register writes. In the complex case a clk ungate | |
543 | * operation may require a fast and a slow part. It is this reason that | |
544 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
545 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
546 | * otherwise. | |
547 | */ | |
548 | int clk_enable(struct clk *clk) | |
549 | { | |
550 | unsigned long flags; | |
551 | int ret; | |
552 | ||
553 | spin_lock_irqsave(&enable_lock, flags); | |
554 | ret = __clk_enable(clk); | |
555 | spin_unlock_irqrestore(&enable_lock, flags); | |
556 | ||
557 | return ret; | |
558 | } | |
559 | EXPORT_SYMBOL_GPL(clk_enable); | |
560 | ||
b2476490 MT |
561 | /** |
562 | * __clk_round_rate - round the given rate for a clk | |
563 | * @clk: round the rate of this clock | |
564 | * | |
565 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
566 | */ | |
567 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
568 | { | |
81536e07 | 569 | unsigned long parent_rate = 0; |
b2476490 MT |
570 | |
571 | if (!clk) | |
2ac6b1f5 | 572 | return 0; |
b2476490 | 573 | |
f4d8af2e SG |
574 | if (!clk->ops->round_rate) { |
575 | if (clk->flags & CLK_SET_RATE_PARENT) | |
576 | return __clk_round_rate(clk->parent, rate); | |
577 | else | |
578 | return clk->rate; | |
579 | } | |
b2476490 | 580 | |
81536e07 SG |
581 | if (clk->parent) |
582 | parent_rate = clk->parent->rate; | |
583 | ||
584 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); | |
b2476490 MT |
585 | } |
586 | ||
587 | /** | |
588 | * clk_round_rate - round the given rate for a clk | |
589 | * @clk: the clk for which we are rounding a rate | |
590 | * @rate: the rate which is to be rounded | |
591 | * | |
592 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
593 | * use which is then returned. If clk doesn't support round_rate operation | |
594 | * then the parent rate is returned. | |
595 | */ | |
596 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
597 | { | |
598 | unsigned long ret; | |
599 | ||
600 | mutex_lock(&prepare_lock); | |
601 | ret = __clk_round_rate(clk, rate); | |
602 | mutex_unlock(&prepare_lock); | |
603 | ||
604 | return ret; | |
605 | } | |
606 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
607 | ||
608 | /** | |
609 | * __clk_notify - call clk notifier chain | |
610 | * @clk: struct clk * that is changing rate | |
611 | * @msg: clk notifier type (see include/linux/clk.h) | |
612 | * @old_rate: old clk rate | |
613 | * @new_rate: new clk rate | |
614 | * | |
615 | * Triggers a notifier call chain on the clk rate-change notification | |
616 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
617 | * and current rates to the notifier callback. Intended to be called by | |
618 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
619 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
620 | * a driver returns that. | |
621 | */ | |
622 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
623 | unsigned long old_rate, unsigned long new_rate) | |
624 | { | |
625 | struct clk_notifier *cn; | |
626 | struct clk_notifier_data cnd; | |
627 | int ret = NOTIFY_DONE; | |
628 | ||
629 | cnd.clk = clk; | |
630 | cnd.old_rate = old_rate; | |
631 | cnd.new_rate = new_rate; | |
632 | ||
633 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
634 | if (cn->clk == clk) { | |
635 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
636 | &cnd); | |
637 | break; | |
638 | } | |
639 | } | |
640 | ||
641 | return ret; | |
642 | } | |
643 | ||
644 | /** | |
645 | * __clk_recalc_rates | |
646 | * @clk: first clk in the subtree | |
647 | * @msg: notification type (see include/linux/clk.h) | |
648 | * | |
649 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
650 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
651 | * it is assumed that the clock will take on the rate of it's parent. | |
652 | * | |
653 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
654 | * if necessary. | |
655 | * | |
656 | * Caller must hold prepare_lock. | |
657 | */ | |
658 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
659 | { | |
660 | unsigned long old_rate; | |
661 | unsigned long parent_rate = 0; | |
662 | struct hlist_node *tmp; | |
663 | struct clk *child; | |
664 | ||
665 | old_rate = clk->rate; | |
666 | ||
667 | if (clk->parent) | |
668 | parent_rate = clk->parent->rate; | |
669 | ||
670 | if (clk->ops->recalc_rate) | |
671 | clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
672 | else | |
673 | clk->rate = parent_rate; | |
674 | ||
675 | /* | |
676 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
677 | * & ABORT_RATE_CHANGE notifiers | |
678 | */ | |
679 | if (clk->notifier_count && msg) | |
680 | __clk_notify(clk, msg, old_rate, clk->rate); | |
681 | ||
682 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
683 | __clk_recalc_rates(child, msg); | |
684 | } | |
685 | ||
a093bde2 UH |
686 | /** |
687 | * clk_get_rate - return the rate of clk | |
688 | * @clk: the clk whose rate is being returned | |
689 | * | |
690 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
691 | * is set, which means a recalc_rate will be issued. | |
692 | * If clk is NULL then returns 0. | |
693 | */ | |
694 | unsigned long clk_get_rate(struct clk *clk) | |
695 | { | |
696 | unsigned long rate; | |
697 | ||
698 | mutex_lock(&prepare_lock); | |
699 | ||
700 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
701 | __clk_recalc_rates(clk, 0); | |
702 | ||
703 | rate = __clk_get_rate(clk); | |
704 | mutex_unlock(&prepare_lock); | |
705 | ||
706 | return rate; | |
707 | } | |
708 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
709 | ||
b2476490 MT |
710 | /** |
711 | * __clk_speculate_rates | |
712 | * @clk: first clk in the subtree | |
713 | * @parent_rate: the "future" rate of clk's parent | |
714 | * | |
715 | * Walks the subtree of clks starting with clk, speculating rates as it | |
716 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
717 | * | |
718 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
719 | * pre-rate change notifications and returns early if no clks in the | |
720 | * subtree have subscribed to the notifications. Note that if a clk does not | |
721 | * implement the .recalc_rate callback then it is assumed that the clock will | |
722 | * take on the rate of it's parent. | |
723 | * | |
724 | * Caller must hold prepare_lock. | |
725 | */ | |
726 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
727 | { | |
728 | struct hlist_node *tmp; | |
729 | struct clk *child; | |
730 | unsigned long new_rate; | |
731 | int ret = NOTIFY_DONE; | |
732 | ||
733 | if (clk->ops->recalc_rate) | |
734 | new_rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
735 | else | |
736 | new_rate = parent_rate; | |
737 | ||
738 | /* abort the rate change if a driver returns NOTIFY_BAD */ | |
739 | if (clk->notifier_count) | |
740 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
741 | ||
742 | if (ret == NOTIFY_BAD) | |
743 | goto out; | |
744 | ||
745 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
746 | ret = __clk_speculate_rates(child, new_rate); | |
747 | if (ret == NOTIFY_BAD) | |
748 | break; | |
749 | } | |
750 | ||
751 | out: | |
752 | return ret; | |
753 | } | |
754 | ||
755 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate) | |
756 | { | |
757 | struct clk *child; | |
758 | struct hlist_node *tmp; | |
759 | ||
760 | clk->new_rate = new_rate; | |
761 | ||
762 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
763 | if (child->ops->recalc_rate) | |
764 | child->new_rate = child->ops->recalc_rate(child->hw, new_rate); | |
765 | else | |
766 | child->new_rate = new_rate; | |
767 | clk_calc_subtree(child, child->new_rate); | |
768 | } | |
769 | } | |
770 | ||
771 | /* | |
772 | * calculate the new rates returning the topmost clock that has to be | |
773 | * changed. | |
774 | */ | |
775 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
776 | { | |
777 | struct clk *top = clk; | |
81536e07 | 778 | unsigned long best_parent_rate = 0; |
b2476490 MT |
779 | unsigned long new_rate; |
780 | ||
7452b219 MT |
781 | /* sanity */ |
782 | if (IS_ERR_OR_NULL(clk)) | |
783 | return NULL; | |
784 | ||
63f5c3b2 MT |
785 | /* save parent rate, if it exists */ |
786 | if (clk->parent) | |
787 | best_parent_rate = clk->parent->rate; | |
788 | ||
7452b219 MT |
789 | /* never propagate up to the parent */ |
790 | if (!(clk->flags & CLK_SET_RATE_PARENT)) { | |
791 | if (!clk->ops->round_rate) { | |
792 | clk->new_rate = clk->rate; | |
793 | return NULL; | |
7452b219 | 794 | } |
63f5c3b2 MT |
795 | new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); |
796 | goto out; | |
7452b219 MT |
797 | } |
798 | ||
799 | /* need clk->parent from here on out */ | |
800 | if (!clk->parent) { | |
801 | pr_debug("%s: %s has NULL parent\n", __func__, clk->name); | |
b2476490 MT |
802 | return NULL; |
803 | } | |
804 | ||
7452b219 | 805 | if (!clk->ops->round_rate) { |
b2476490 | 806 | top = clk_calc_new_rates(clk->parent, rate); |
1b2f9903 | 807 | new_rate = clk->parent->new_rate; |
b2476490 MT |
808 | |
809 | goto out; | |
810 | } | |
811 | ||
7452b219 | 812 | new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); |
b2476490 MT |
813 | |
814 | if (best_parent_rate != clk->parent->rate) { | |
815 | top = clk_calc_new_rates(clk->parent, best_parent_rate); | |
816 | ||
817 | goto out; | |
818 | } | |
819 | ||
820 | out: | |
821 | clk_calc_subtree(clk, new_rate); | |
822 | ||
823 | return top; | |
824 | } | |
825 | ||
826 | /* | |
827 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
828 | * so that in case of an error we can walk down the whole tree again and | |
829 | * abort the change. | |
830 | */ | |
831 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
832 | { | |
833 | struct hlist_node *tmp; | |
834 | struct clk *child, *fail_clk = NULL; | |
835 | int ret = NOTIFY_DONE; | |
836 | ||
837 | if (clk->rate == clk->new_rate) | |
838 | return 0; | |
839 | ||
840 | if (clk->notifier_count) { | |
841 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
842 | if (ret == NOTIFY_BAD) | |
843 | fail_clk = clk; | |
844 | } | |
845 | ||
846 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
847 | clk = clk_propagate_rate_change(child, event); | |
848 | if (clk) | |
849 | fail_clk = clk; | |
850 | } | |
851 | ||
852 | return fail_clk; | |
853 | } | |
854 | ||
855 | /* | |
856 | * walk down a subtree and set the new rates notifying the rate | |
857 | * change on the way | |
858 | */ | |
859 | static void clk_change_rate(struct clk *clk) | |
860 | { | |
861 | struct clk *child; | |
862 | unsigned long old_rate; | |
bf47b4fd | 863 | unsigned long best_parent_rate = 0; |
b2476490 MT |
864 | struct hlist_node *tmp; |
865 | ||
866 | old_rate = clk->rate; | |
867 | ||
bf47b4fd PM |
868 | if (clk->parent) |
869 | best_parent_rate = clk->parent->rate; | |
870 | ||
b2476490 | 871 | if (clk->ops->set_rate) |
bf47b4fd | 872 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 MT |
873 | |
874 | if (clk->ops->recalc_rate) | |
bf47b4fd | 875 | clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate); |
b2476490 | 876 | else |
bf47b4fd | 877 | clk->rate = best_parent_rate; |
b2476490 MT |
878 | |
879 | if (clk->notifier_count && old_rate != clk->rate) | |
880 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
881 | ||
882 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
883 | clk_change_rate(child); | |
884 | } | |
885 | ||
886 | /** | |
887 | * clk_set_rate - specify a new rate for clk | |
888 | * @clk: the clk whose rate is being changed | |
889 | * @rate: the new rate for clk | |
890 | * | |
5654dc94 | 891 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 892 | * |
5654dc94 MT |
893 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
894 | * propagate up to clk's parent; whether or not this happens depends on the | |
895 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
896 | * after calling .round_rate then upstream parent propagation is ignored. If | |
897 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
898 | * up to clk's parent and set it's rate. Upward propagation will continue | |
899 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or | |
900 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 901 | * |
5654dc94 MT |
902 | * Rate changes are accomplished via tree traversal that also recalculates the |
903 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
904 | * |
905 | * Returns 0 on success, -EERROR otherwise. | |
906 | */ | |
907 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
908 | { | |
909 | struct clk *top, *fail_clk; | |
910 | int ret = 0; | |
911 | ||
912 | /* prevent racing with updates to the clock topology */ | |
913 | mutex_lock(&prepare_lock); | |
914 | ||
915 | /* bail early if nothing to do */ | |
916 | if (rate == clk->rate) | |
917 | goto out; | |
918 | ||
7e0fa1b5 | 919 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
920 | ret = -EBUSY; |
921 | goto out; | |
922 | } | |
923 | ||
b2476490 MT |
924 | /* calculate new rates and get the topmost changed clock */ |
925 | top = clk_calc_new_rates(clk, rate); | |
926 | if (!top) { | |
927 | ret = -EINVAL; | |
928 | goto out; | |
929 | } | |
930 | ||
931 | /* notify that we are about to change rates */ | |
932 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
933 | if (fail_clk) { | |
934 | pr_warn("%s: failed to set %s rate\n", __func__, | |
935 | fail_clk->name); | |
936 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
937 | ret = -EBUSY; | |
938 | goto out; | |
939 | } | |
940 | ||
941 | /* change the rates */ | |
942 | clk_change_rate(top); | |
943 | ||
944 | mutex_unlock(&prepare_lock); | |
945 | ||
946 | return 0; | |
947 | out: | |
948 | mutex_unlock(&prepare_lock); | |
949 | ||
950 | return ret; | |
951 | } | |
952 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
953 | ||
954 | /** | |
955 | * clk_get_parent - return the parent of a clk | |
956 | * @clk: the clk whose parent gets returned | |
957 | * | |
958 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
959 | */ | |
960 | struct clk *clk_get_parent(struct clk *clk) | |
961 | { | |
962 | struct clk *parent; | |
963 | ||
964 | mutex_lock(&prepare_lock); | |
965 | parent = __clk_get_parent(clk); | |
966 | mutex_unlock(&prepare_lock); | |
967 | ||
968 | return parent; | |
969 | } | |
970 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
971 | ||
972 | /* | |
973 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
974 | * optional for single-parent clocks. Always call .get_parent if it is | |
975 | * available and WARN if it is missing for multi-parent clocks. | |
976 | * | |
977 | * For single-parent clocks without .get_parent, first check to see if the | |
978 | * .parents array exists, and if so use it to avoid an expensive tree | |
979 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
980 | */ | |
981 | static struct clk *__clk_init_parent(struct clk *clk) | |
982 | { | |
983 | struct clk *ret = NULL; | |
984 | u8 index; | |
985 | ||
986 | /* handle the trivial cases */ | |
987 | ||
988 | if (!clk->num_parents) | |
989 | goto out; | |
990 | ||
991 | if (clk->num_parents == 1) { | |
992 | if (IS_ERR_OR_NULL(clk->parent)) | |
993 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); | |
994 | ret = clk->parent; | |
995 | goto out; | |
996 | } | |
997 | ||
998 | if (!clk->ops->get_parent) { | |
999 | WARN(!clk->ops->get_parent, | |
1000 | "%s: multi-parent clocks must implement .get_parent\n", | |
1001 | __func__); | |
1002 | goto out; | |
1003 | }; | |
1004 | ||
1005 | /* | |
1006 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1007 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1008 | * clk->parent here; that is done by the calling function | |
1009 | */ | |
1010 | ||
1011 | index = clk->ops->get_parent(clk->hw); | |
1012 | ||
1013 | if (!clk->parents) | |
1014 | clk->parents = | |
7975059d | 1015 | kzalloc((sizeof(struct clk*) * clk->num_parents), |
b2476490 MT |
1016 | GFP_KERNEL); |
1017 | ||
1018 | if (!clk->parents) | |
1019 | ret = __clk_lookup(clk->parent_names[index]); | |
1020 | else if (!clk->parents[index]) | |
1021 | ret = clk->parents[index] = | |
1022 | __clk_lookup(clk->parent_names[index]); | |
1023 | else | |
1024 | ret = clk->parents[index]; | |
1025 | ||
1026 | out: | |
1027 | return ret; | |
1028 | } | |
1029 | ||
1030 | void __clk_reparent(struct clk *clk, struct clk *new_parent) | |
1031 | { | |
1032 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
1033 | struct dentry *d; | |
1034 | struct dentry *new_parent_d; | |
1035 | #endif | |
1036 | ||
1037 | if (!clk || !new_parent) | |
1038 | return; | |
1039 | ||
1040 | hlist_del(&clk->child_node); | |
1041 | ||
1042 | if (new_parent) | |
1043 | hlist_add_head(&clk->child_node, &new_parent->children); | |
1044 | else | |
1045 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1046 | ||
1047 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
1048 | if (!inited) | |
1049 | goto out; | |
1050 | ||
1051 | if (new_parent) | |
1052 | new_parent_d = new_parent->dentry; | |
1053 | else | |
1054 | new_parent_d = orphandir; | |
1055 | ||
1056 | d = debugfs_rename(clk->dentry->d_parent, clk->dentry, | |
1057 | new_parent_d, clk->name); | |
1058 | if (d) | |
1059 | clk->dentry = d; | |
1060 | else | |
1061 | pr_debug("%s: failed to rename debugfs entry for %s\n", | |
1062 | __func__, clk->name); | |
1063 | out: | |
1064 | #endif | |
1065 | ||
1066 | clk->parent = new_parent; | |
1067 | ||
1068 | __clk_recalc_rates(clk, POST_RATE_CHANGE); | |
1069 | } | |
1070 | ||
1071 | static int __clk_set_parent(struct clk *clk, struct clk *parent) | |
1072 | { | |
1073 | struct clk *old_parent; | |
1074 | unsigned long flags; | |
1075 | int ret = -EINVAL; | |
1076 | u8 i; | |
1077 | ||
1078 | old_parent = clk->parent; | |
1079 | ||
863b1327 | 1080 | if (!clk->parents) |
7975059d RN |
1081 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), |
1082 | GFP_KERNEL); | |
b2476490 MT |
1083 | |
1084 | /* | |
863b1327 RN |
1085 | * find index of new parent clock using cached parent ptrs, |
1086 | * or if not yet cached, use string name comparison and cache | |
1087 | * them now to avoid future calls to __clk_lookup. | |
b2476490 | 1088 | */ |
863b1327 RN |
1089 | for (i = 0; i < clk->num_parents; i++) { |
1090 | if (clk->parents && clk->parents[i] == parent) | |
1091 | break; | |
1092 | else if (!strcmp(clk->parent_names[i], parent->name)) { | |
1093 | if (clk->parents) | |
1094 | clk->parents[i] = __clk_lookup(parent->name); | |
1095 | break; | |
1096 | } | |
1097 | } | |
b2476490 MT |
1098 | |
1099 | if (i == clk->num_parents) { | |
1100 | pr_debug("%s: clock %s is not a possible parent of clock %s\n", | |
1101 | __func__, parent->name, clk->name); | |
1102 | goto out; | |
1103 | } | |
1104 | ||
1105 | /* migrate prepare and enable */ | |
1106 | if (clk->prepare_count) | |
1107 | __clk_prepare(parent); | |
1108 | ||
1109 | /* FIXME replace with clk_is_enabled(clk) someday */ | |
1110 | spin_lock_irqsave(&enable_lock, flags); | |
1111 | if (clk->enable_count) | |
1112 | __clk_enable(parent); | |
1113 | spin_unlock_irqrestore(&enable_lock, flags); | |
1114 | ||
1115 | /* change clock input source */ | |
1116 | ret = clk->ops->set_parent(clk->hw, i); | |
1117 | ||
1118 | /* clean up old prepare and enable */ | |
1119 | spin_lock_irqsave(&enable_lock, flags); | |
1120 | if (clk->enable_count) | |
1121 | __clk_disable(old_parent); | |
1122 | spin_unlock_irqrestore(&enable_lock, flags); | |
1123 | ||
1124 | if (clk->prepare_count) | |
1125 | __clk_unprepare(old_parent); | |
1126 | ||
1127 | out: | |
1128 | return ret; | |
1129 | } | |
1130 | ||
1131 | /** | |
1132 | * clk_set_parent - switch the parent of a mux clk | |
1133 | * @clk: the mux clk whose input we are switching | |
1134 | * @parent: the new input to clk | |
1135 | * | |
1136 | * Re-parent clk to use parent as it's new input source. If clk has the | |
1137 | * CLK_SET_PARENT_GATE flag set then clk must be gated for this | |
1138 | * operation to succeed. After successfully changing clk's parent | |
1139 | * clk_set_parent will update the clk topology, sysfs topology and | |
1140 | * propagate rate recalculation via __clk_recalc_rates. Returns 0 on | |
1141 | * success, -EERROR otherwise. | |
1142 | */ | |
1143 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
1144 | { | |
1145 | int ret = 0; | |
1146 | ||
1147 | if (!clk || !clk->ops) | |
1148 | return -EINVAL; | |
1149 | ||
1150 | if (!clk->ops->set_parent) | |
1151 | return -ENOSYS; | |
1152 | ||
1153 | /* prevent racing with updates to the clock topology */ | |
1154 | mutex_lock(&prepare_lock); | |
1155 | ||
1156 | if (clk->parent == parent) | |
1157 | goto out; | |
1158 | ||
1159 | /* propagate PRE_RATE_CHANGE notifications */ | |
1160 | if (clk->notifier_count) | |
1161 | ret = __clk_speculate_rates(clk, parent->rate); | |
1162 | ||
1163 | /* abort if a driver objects */ | |
1164 | if (ret == NOTIFY_STOP) | |
1165 | goto out; | |
1166 | ||
1167 | /* only re-parent if the clock is not in use */ | |
1168 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) | |
1169 | ret = -EBUSY; | |
1170 | else | |
1171 | ret = __clk_set_parent(clk, parent); | |
1172 | ||
1173 | /* propagate ABORT_RATE_CHANGE if .set_parent failed */ | |
1174 | if (ret) { | |
1175 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); | |
1176 | goto out; | |
1177 | } | |
1178 | ||
1179 | /* propagate rate recalculation downstream */ | |
1180 | __clk_reparent(clk, parent); | |
1181 | ||
1182 | out: | |
1183 | mutex_unlock(&prepare_lock); | |
1184 | ||
1185 | return ret; | |
1186 | } | |
1187 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1188 | ||
1189 | /** | |
1190 | * __clk_init - initialize the data structures in a struct clk | |
1191 | * @dev: device initializing this clk, placeholder for now | |
1192 | * @clk: clk being initialized | |
1193 | * | |
1194 | * Initializes the lists in struct clk, queries the hardware for the | |
1195 | * parent and rate and sets them both. | |
b2476490 | 1196 | */ |
d1302a36 | 1197 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1198 | { |
d1302a36 | 1199 | int i, ret = 0; |
b2476490 MT |
1200 | struct clk *orphan; |
1201 | struct hlist_node *tmp, *tmp2; | |
1202 | ||
1203 | if (!clk) | |
d1302a36 | 1204 | return -EINVAL; |
b2476490 MT |
1205 | |
1206 | mutex_lock(&prepare_lock); | |
1207 | ||
1208 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1209 | if (__clk_lookup(clk->name)) { |
1210 | pr_debug("%s: clk %s already initialized\n", | |
1211 | __func__, clk->name); | |
1212 | ret = -EEXIST; | |
b2476490 | 1213 | goto out; |
d1302a36 | 1214 | } |
b2476490 | 1215 | |
d4d7e3dd MT |
1216 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1217 | if (clk->ops->set_rate && | |
1218 | !(clk->ops->round_rate && clk->ops->recalc_rate)) { | |
1219 | pr_warning("%s: %s must implement .round_rate & .recalc_rate\n", | |
1220 | __func__, clk->name); | |
d1302a36 | 1221 | ret = -EINVAL; |
d4d7e3dd MT |
1222 | goto out; |
1223 | } | |
1224 | ||
1225 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1226 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1227 | __func__, clk->name); | |
d1302a36 | 1228 | ret = -EINVAL; |
d4d7e3dd MT |
1229 | goto out; |
1230 | } | |
1231 | ||
b2476490 MT |
1232 | /* throw a WARN if any entries in parent_names are NULL */ |
1233 | for (i = 0; i < clk->num_parents; i++) | |
1234 | WARN(!clk->parent_names[i], | |
1235 | "%s: invalid NULL in %s's .parent_names\n", | |
1236 | __func__, clk->name); | |
1237 | ||
1238 | /* | |
1239 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1240 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1241 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1242 | * must always check for a NULL pointer and try to populate it if | |
1243 | * necessary. | |
1244 | * | |
1245 | * If clk->parents is not NULL we skip this entire block. This allows | |
1246 | * for clock drivers to statically initialize clk->parents. | |
1247 | */ | |
9ca1c5a4 RN |
1248 | if (clk->num_parents > 1 && !clk->parents) { |
1249 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), | |
b2476490 MT |
1250 | GFP_KERNEL); |
1251 | /* | |
1252 | * __clk_lookup returns NULL for parents that have not been | |
1253 | * clk_init'd; thus any access to clk->parents[] must check | |
1254 | * for a NULL pointer. We can always perform lazy lookups for | |
1255 | * missing parents later on. | |
1256 | */ | |
1257 | if (clk->parents) | |
1258 | for (i = 0; i < clk->num_parents; i++) | |
1259 | clk->parents[i] = | |
1260 | __clk_lookup(clk->parent_names[i]); | |
1261 | } | |
1262 | ||
1263 | clk->parent = __clk_init_parent(clk); | |
1264 | ||
1265 | /* | |
1266 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1267 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1268 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1269 | * clk list. | |
1270 | * | |
1271 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1272 | * clocks and re-parent any that are children of the clock currently | |
1273 | * being clk_init'd. | |
1274 | */ | |
1275 | if (clk->parent) | |
1276 | hlist_add_head(&clk->child_node, | |
1277 | &clk->parent->children); | |
1278 | else if (clk->flags & CLK_IS_ROOT) | |
1279 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1280 | else | |
1281 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1282 | ||
1283 | /* | |
1284 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1285 | * simple clocks and lazy developers the default fallback is to use the | |
1286 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1287 | * then rate is set to zero. | |
1288 | */ | |
1289 | if (clk->ops->recalc_rate) | |
1290 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1291 | __clk_get_rate(clk->parent)); | |
1292 | else if (clk->parent) | |
1293 | clk->rate = clk->parent->rate; | |
1294 | else | |
1295 | clk->rate = 0; | |
1296 | ||
1297 | /* | |
1298 | * walk the list of orphan clocks and reparent any that are children of | |
1299 | * this clock | |
1300 | */ | |
1f61e5f1 MF |
1301 | hlist_for_each_entry_safe(orphan, tmp, tmp2, &clk_orphan_list, child_node) { |
1302 | if (orphan->ops->get_parent) { | |
1303 | i = orphan->ops->get_parent(orphan->hw); | |
1304 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1305 | __clk_reparent(orphan, clk); | |
1306 | continue; | |
1307 | } | |
1308 | ||
b2476490 MT |
1309 | for (i = 0; i < orphan->num_parents; i++) |
1310 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1311 | __clk_reparent(orphan, clk); | |
1312 | break; | |
1313 | } | |
1f61e5f1 | 1314 | } |
b2476490 MT |
1315 | |
1316 | /* | |
1317 | * optional platform-specific magic | |
1318 | * | |
1319 | * The .init callback is not used by any of the basic clock types, but | |
1320 | * exists for weird hardware that must perform initialization magic. | |
1321 | * Please consider other ways of solving initialization problems before | |
1322 | * using this callback, as it's use is discouraged. | |
1323 | */ | |
1324 | if (clk->ops->init) | |
1325 | clk->ops->init(clk->hw); | |
1326 | ||
1327 | clk_debug_register(clk); | |
1328 | ||
1329 | out: | |
1330 | mutex_unlock(&prepare_lock); | |
1331 | ||
d1302a36 | 1332 | return ret; |
b2476490 MT |
1333 | } |
1334 | ||
0197b3ea SK |
1335 | /** |
1336 | * __clk_register - register a clock and return a cookie. | |
1337 | * | |
1338 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1339 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1340 | * of the struct clk need to be initialized. | |
1341 | * | |
1342 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1343 | * data. | |
1344 | * | |
1345 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1346 | * very large numbers of clocks that need to be statically initialized. It is | |
1347 | * a layering violation to include clk-private.h from any code which implements | |
1348 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
1349 | * separate C file from the logic that implements it's operations. Returns 0 | |
1350 | * on success, otherwise an error code. | |
1351 | */ | |
1352 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
1353 | { | |
1354 | int ret; | |
1355 | struct clk *clk; | |
1356 | ||
1357 | clk = hw->clk; | |
1358 | clk->name = hw->init->name; | |
1359 | clk->ops = hw->init->ops; | |
1360 | clk->hw = hw; | |
1361 | clk->flags = hw->init->flags; | |
1362 | clk->parent_names = hw->init->parent_names; | |
1363 | clk->num_parents = hw->init->num_parents; | |
1364 | ||
1365 | ret = __clk_init(dev, clk); | |
1366 | if (ret) | |
1367 | return ERR_PTR(ret); | |
1368 | ||
1369 | return clk; | |
1370 | } | |
1371 | EXPORT_SYMBOL_GPL(__clk_register); | |
1372 | ||
46c8773a | 1373 | static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk) |
b2476490 | 1374 | { |
d1302a36 | 1375 | int i, ret; |
b2476490 | 1376 | |
0197b3ea SK |
1377 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
1378 | if (!clk->name) { | |
1379 | pr_err("%s: could not allocate clk->name\n", __func__); | |
1380 | ret = -ENOMEM; | |
1381 | goto fail_name; | |
1382 | } | |
1383 | clk->ops = hw->init->ops; | |
b2476490 | 1384 | clk->hw = hw; |
0197b3ea SK |
1385 | clk->flags = hw->init->flags; |
1386 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
1387 | hw->clk = clk; |
1388 | ||
d1302a36 | 1389 | /* allocate local copy in case parent_names is __initdata */ |
0197b3ea | 1390 | clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents), |
d1302a36 MT |
1391 | GFP_KERNEL); |
1392 | ||
1393 | if (!clk->parent_names) { | |
1394 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
1395 | ret = -ENOMEM; | |
1396 | goto fail_parent_names; | |
1397 | } | |
1398 | ||
1399 | ||
1400 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea SK |
1401 | for (i = 0; i < clk->num_parents; i++) { |
1402 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], | |
1403 | GFP_KERNEL); | |
d1302a36 MT |
1404 | if (!clk->parent_names[i]) { |
1405 | pr_err("%s: could not copy parent_names\n", __func__); | |
1406 | ret = -ENOMEM; | |
1407 | goto fail_parent_names_copy; | |
1408 | } | |
1409 | } | |
1410 | ||
1411 | ret = __clk_init(dev, clk); | |
1412 | if (!ret) | |
46c8773a | 1413 | return 0; |
b2476490 | 1414 | |
d1302a36 MT |
1415 | fail_parent_names_copy: |
1416 | while (--i >= 0) | |
1417 | kfree(clk->parent_names[i]); | |
1418 | kfree(clk->parent_names); | |
1419 | fail_parent_names: | |
0197b3ea SK |
1420 | kfree(clk->name); |
1421 | fail_name: | |
46c8773a SB |
1422 | return ret; |
1423 | } | |
1424 | ||
1425 | /** | |
1426 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
1427 | * @dev: device that is registering this clock | |
1428 | * @hw: link to hardware-specific clock data | |
1429 | * | |
1430 | * clk_register is the primary interface for populating the clock tree with new | |
1431 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
1432 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
1433 | * rest of the clock API. In the event of an error clk_register will return an | |
1434 | * error code; drivers must test for an error code after calling clk_register. | |
1435 | */ | |
1436 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
1437 | { | |
1438 | int ret; | |
1439 | struct clk *clk; | |
1440 | ||
1441 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
1442 | if (!clk) { | |
1443 | pr_err("%s: could not allocate clk\n", __func__); | |
1444 | ret = -ENOMEM; | |
1445 | goto fail_out; | |
1446 | } | |
1447 | ||
1448 | ret = _clk_register(dev, hw, clk); | |
1449 | if (!ret) | |
1450 | return clk; | |
1451 | ||
d1302a36 MT |
1452 | kfree(clk); |
1453 | fail_out: | |
1454 | return ERR_PTR(ret); | |
b2476490 MT |
1455 | } |
1456 | EXPORT_SYMBOL_GPL(clk_register); | |
1457 | ||
1df5c939 MB |
1458 | /** |
1459 | * clk_unregister - unregister a currently registered clock | |
1460 | * @clk: clock to unregister | |
1461 | * | |
1462 | * Currently unimplemented. | |
1463 | */ | |
1464 | void clk_unregister(struct clk *clk) {} | |
1465 | EXPORT_SYMBOL_GPL(clk_unregister); | |
1466 | ||
46c8773a SB |
1467 | static void devm_clk_release(struct device *dev, void *res) |
1468 | { | |
1469 | clk_unregister(res); | |
1470 | } | |
1471 | ||
1472 | /** | |
1473 | * devm_clk_register - resource managed clk_register() | |
1474 | * @dev: device that is registering this clock | |
1475 | * @hw: link to hardware-specific clock data | |
1476 | * | |
1477 | * Managed clk_register(). Clocks returned from this function are | |
1478 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
1479 | * more information. | |
1480 | */ | |
1481 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
1482 | { | |
1483 | struct clk *clk; | |
1484 | int ret; | |
1485 | ||
1486 | clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL); | |
1487 | if (!clk) | |
1488 | return ERR_PTR(-ENOMEM); | |
1489 | ||
1490 | ret = _clk_register(dev, hw, clk); | |
1491 | if (!ret) { | |
1492 | devres_add(dev, clk); | |
1493 | } else { | |
1494 | devres_free(clk); | |
1495 | clk = ERR_PTR(ret); | |
1496 | } | |
1497 | ||
1498 | return clk; | |
1499 | } | |
1500 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
1501 | ||
1502 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
1503 | { | |
1504 | struct clk *c = res; | |
1505 | if (WARN_ON(!c)) | |
1506 | return 0; | |
1507 | return c == data; | |
1508 | } | |
1509 | ||
1510 | /** | |
1511 | * devm_clk_unregister - resource managed clk_unregister() | |
1512 | * @clk: clock to unregister | |
1513 | * | |
1514 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
1515 | * this function will not need to be called and the resource management | |
1516 | * code will ensure that the resource is freed. | |
1517 | */ | |
1518 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
1519 | { | |
1520 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
1521 | } | |
1522 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
1523 | ||
b2476490 MT |
1524 | /*** clk rate change notifiers ***/ |
1525 | ||
1526 | /** | |
1527 | * clk_notifier_register - add a clk rate change notifier | |
1528 | * @clk: struct clk * to watch | |
1529 | * @nb: struct notifier_block * with callback info | |
1530 | * | |
1531 | * Request notification when clk's rate changes. This uses an SRCU | |
1532 | * notifier because we want it to block and notifier unregistrations are | |
1533 | * uncommon. The callbacks associated with the notifier must not | |
1534 | * re-enter into the clk framework by calling any top-level clk APIs; | |
1535 | * this will cause a nested prepare_lock mutex. | |
1536 | * | |
1537 | * Pre-change notifier callbacks will be passed the current, pre-change | |
1538 | * rate of the clk via struct clk_notifier_data.old_rate. The new, | |
1539 | * post-change rate of the clk is passed via struct | |
1540 | * clk_notifier_data.new_rate. | |
1541 | * | |
1542 | * Post-change notifiers will pass the now-current, post-change rate of | |
1543 | * the clk in both struct clk_notifier_data.old_rate and struct | |
1544 | * clk_notifier_data.new_rate. | |
1545 | * | |
1546 | * Abort-change notifiers are effectively the opposite of pre-change | |
1547 | * notifiers: the original pre-change clk rate is passed in via struct | |
1548 | * clk_notifier_data.new_rate and the failed post-change rate is passed | |
1549 | * in via struct clk_notifier_data.old_rate. | |
1550 | * | |
1551 | * clk_notifier_register() must be called from non-atomic context. | |
1552 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
1553 | * allocation failure; otherwise, passes along the return value of | |
1554 | * srcu_notifier_chain_register(). | |
1555 | */ | |
1556 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
1557 | { | |
1558 | struct clk_notifier *cn; | |
1559 | int ret = -ENOMEM; | |
1560 | ||
1561 | if (!clk || !nb) | |
1562 | return -EINVAL; | |
1563 | ||
1564 | mutex_lock(&prepare_lock); | |
1565 | ||
1566 | /* search the list of notifiers for this clk */ | |
1567 | list_for_each_entry(cn, &clk_notifier_list, node) | |
1568 | if (cn->clk == clk) | |
1569 | break; | |
1570 | ||
1571 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
1572 | if (cn->clk != clk) { | |
1573 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
1574 | if (!cn) | |
1575 | goto out; | |
1576 | ||
1577 | cn->clk = clk; | |
1578 | srcu_init_notifier_head(&cn->notifier_head); | |
1579 | ||
1580 | list_add(&cn->node, &clk_notifier_list); | |
1581 | } | |
1582 | ||
1583 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
1584 | ||
1585 | clk->notifier_count++; | |
1586 | ||
1587 | out: | |
1588 | mutex_unlock(&prepare_lock); | |
1589 | ||
1590 | return ret; | |
1591 | } | |
1592 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
1593 | ||
1594 | /** | |
1595 | * clk_notifier_unregister - remove a clk rate change notifier | |
1596 | * @clk: struct clk * | |
1597 | * @nb: struct notifier_block * with callback info | |
1598 | * | |
1599 | * Request no further notification for changes to 'clk' and frees memory | |
1600 | * allocated in clk_notifier_register. | |
1601 | * | |
1602 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
1603 | * along the return value of srcu_notifier_chain_unregister(). | |
1604 | */ | |
1605 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
1606 | { | |
1607 | struct clk_notifier *cn = NULL; | |
1608 | int ret = -EINVAL; | |
1609 | ||
1610 | if (!clk || !nb) | |
1611 | return -EINVAL; | |
1612 | ||
1613 | mutex_lock(&prepare_lock); | |
1614 | ||
1615 | list_for_each_entry(cn, &clk_notifier_list, node) | |
1616 | if (cn->clk == clk) | |
1617 | break; | |
1618 | ||
1619 | if (cn->clk == clk) { | |
1620 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
1621 | ||
1622 | clk->notifier_count--; | |
1623 | ||
1624 | /* XXX the notifier code should handle this better */ | |
1625 | if (!cn->notifier_head.head) { | |
1626 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
1627 | kfree(cn); | |
1628 | } | |
1629 | ||
1630 | } else { | |
1631 | ret = -ENOENT; | |
1632 | } | |
1633 | ||
1634 | mutex_unlock(&prepare_lock); | |
1635 | ||
1636 | return ret; | |
1637 | } | |
1638 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
1639 | |
1640 | #ifdef CONFIG_OF | |
1641 | /** | |
1642 | * struct of_clk_provider - Clock provider registration structure | |
1643 | * @link: Entry in global list of clock providers | |
1644 | * @node: Pointer to device tree node of clock provider | |
1645 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
1646 | * given clock specifier | |
1647 | * @data: context pointer to be passed into @get callback | |
1648 | */ | |
1649 | struct of_clk_provider { | |
1650 | struct list_head link; | |
1651 | ||
1652 | struct device_node *node; | |
1653 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
1654 | void *data; | |
1655 | }; | |
1656 | ||
1657 | static LIST_HEAD(of_clk_providers); | |
1658 | static DEFINE_MUTEX(of_clk_lock); | |
1659 | ||
1660 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
1661 | void *data) | |
1662 | { | |
1663 | return data; | |
1664 | } | |
1665 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
1666 | ||
494bfec9 SG |
1667 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
1668 | { | |
1669 | struct clk_onecell_data *clk_data = data; | |
1670 | unsigned int idx = clkspec->args[0]; | |
1671 | ||
1672 | if (idx >= clk_data->clk_num) { | |
1673 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
1674 | return ERR_PTR(-EINVAL); | |
1675 | } | |
1676 | ||
1677 | return clk_data->clks[idx]; | |
1678 | } | |
1679 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
1680 | ||
766e6a4e GL |
1681 | /** |
1682 | * of_clk_add_provider() - Register a clock provider for a node | |
1683 | * @np: Device node pointer associated with clock provider | |
1684 | * @clk_src_get: callback for decoding clock | |
1685 | * @data: context pointer for @clk_src_get callback. | |
1686 | */ | |
1687 | int of_clk_add_provider(struct device_node *np, | |
1688 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
1689 | void *data), | |
1690 | void *data) | |
1691 | { | |
1692 | struct of_clk_provider *cp; | |
1693 | ||
1694 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
1695 | if (!cp) | |
1696 | return -ENOMEM; | |
1697 | ||
1698 | cp->node = of_node_get(np); | |
1699 | cp->data = data; | |
1700 | cp->get = clk_src_get; | |
1701 | ||
1702 | mutex_lock(&of_clk_lock); | |
1703 | list_add(&cp->link, &of_clk_providers); | |
1704 | mutex_unlock(&of_clk_lock); | |
1705 | pr_debug("Added clock from %s\n", np->full_name); | |
1706 | ||
1707 | return 0; | |
1708 | } | |
1709 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
1710 | ||
1711 | /** | |
1712 | * of_clk_del_provider() - Remove a previously registered clock provider | |
1713 | * @np: Device node pointer associated with clock provider | |
1714 | */ | |
1715 | void of_clk_del_provider(struct device_node *np) | |
1716 | { | |
1717 | struct of_clk_provider *cp; | |
1718 | ||
1719 | mutex_lock(&of_clk_lock); | |
1720 | list_for_each_entry(cp, &of_clk_providers, link) { | |
1721 | if (cp->node == np) { | |
1722 | list_del(&cp->link); | |
1723 | of_node_put(cp->node); | |
1724 | kfree(cp); | |
1725 | break; | |
1726 | } | |
1727 | } | |
1728 | mutex_unlock(&of_clk_lock); | |
1729 | } | |
1730 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
1731 | ||
1732 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
1733 | { | |
1734 | struct of_clk_provider *provider; | |
1735 | struct clk *clk = ERR_PTR(-ENOENT); | |
1736 | ||
1737 | /* Check if we have such a provider in our array */ | |
1738 | mutex_lock(&of_clk_lock); | |
1739 | list_for_each_entry(provider, &of_clk_providers, link) { | |
1740 | if (provider->node == clkspec->np) | |
1741 | clk = provider->get(clkspec, provider->data); | |
1742 | if (!IS_ERR(clk)) | |
1743 | break; | |
1744 | } | |
1745 | mutex_unlock(&of_clk_lock); | |
1746 | ||
1747 | return clk; | |
1748 | } | |
1749 | ||
1750 | const char *of_clk_get_parent_name(struct device_node *np, int index) | |
1751 | { | |
1752 | struct of_phandle_args clkspec; | |
1753 | const char *clk_name; | |
1754 | int rc; | |
1755 | ||
1756 | if (index < 0) | |
1757 | return NULL; | |
1758 | ||
1759 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
1760 | &clkspec); | |
1761 | if (rc) | |
1762 | return NULL; | |
1763 | ||
1764 | if (of_property_read_string_index(clkspec.np, "clock-output-names", | |
1765 | clkspec.args_count ? clkspec.args[0] : 0, | |
1766 | &clk_name) < 0) | |
1767 | clk_name = clkspec.np->name; | |
1768 | ||
1769 | of_node_put(clkspec.np); | |
1770 | return clk_name; | |
1771 | } | |
1772 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
1773 | ||
1774 | /** | |
1775 | * of_clk_init() - Scan and init clock providers from the DT | |
1776 | * @matches: array of compatible values and init functions for providers. | |
1777 | * | |
1778 | * This function scans the device tree for matching clock providers and | |
1779 | * calls their initialization functions | |
1780 | */ | |
1781 | void __init of_clk_init(const struct of_device_id *matches) | |
1782 | { | |
1783 | struct device_node *np; | |
1784 | ||
1785 | for_each_matching_node(np, matches) { | |
1786 | const struct of_device_id *match = of_match_node(matches, np); | |
1787 | of_clk_init_cb_t clk_init_cb = match->data; | |
1788 | clk_init_cb(np); | |
1789 | } | |
1790 | } | |
1791 | #endif |