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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 | ||
7c045a55 MT |
222 | /* |
223 | * some gate clocks have special needs during the disable-unused | |
224 | * sequence. call .disable_unused if available, otherwise fall | |
225 | * back to .disable | |
226 | */ | |
227 | if (__clk_is_enabled(clk)) { | |
228 | if (clk->ops->disable_unused) | |
229 | clk->ops->disable_unused(clk->hw); | |
230 | else if (clk->ops->disable) | |
231 | clk->ops->disable(clk->hw); | |
232 | } | |
b2476490 MT |
233 | |
234 | unlock_out: | |
235 | spin_unlock_irqrestore(&enable_lock, flags); | |
236 | ||
237 | out: | |
238 | return; | |
239 | } | |
240 | ||
241 | static int clk_disable_unused(void) | |
242 | { | |
243 | struct clk *clk; | |
244 | struct hlist_node *tmp; | |
245 | ||
246 | mutex_lock(&prepare_lock); | |
247 | ||
248 | hlist_for_each_entry(clk, tmp, &clk_root_list, child_node) | |
249 | clk_disable_unused_subtree(clk); | |
250 | ||
251 | hlist_for_each_entry(clk, tmp, &clk_orphan_list, child_node) | |
252 | clk_disable_unused_subtree(clk); | |
253 | ||
254 | mutex_unlock(&prepare_lock); | |
255 | ||
256 | return 0; | |
257 | } | |
258 | late_initcall(clk_disable_unused); | |
b2476490 MT |
259 | |
260 | /*** helper functions ***/ | |
261 | ||
65800b2c | 262 | const char *__clk_get_name(struct clk *clk) |
b2476490 MT |
263 | { |
264 | return !clk ? NULL : clk->name; | |
265 | } | |
266 | ||
65800b2c | 267 | struct clk_hw *__clk_get_hw(struct clk *clk) |
b2476490 MT |
268 | { |
269 | return !clk ? NULL : clk->hw; | |
270 | } | |
271 | ||
65800b2c | 272 | u8 __clk_get_num_parents(struct clk *clk) |
b2476490 | 273 | { |
2ac6b1f5 | 274 | return !clk ? 0 : clk->num_parents; |
b2476490 MT |
275 | } |
276 | ||
65800b2c | 277 | struct clk *__clk_get_parent(struct clk *clk) |
b2476490 MT |
278 | { |
279 | return !clk ? NULL : clk->parent; | |
280 | } | |
281 | ||
65800b2c | 282 | unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 283 | { |
2ac6b1f5 | 284 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
285 | } |
286 | ||
65800b2c | 287 | unsigned int __clk_get_prepare_count(struct clk *clk) |
b2476490 | 288 | { |
2ac6b1f5 | 289 | return !clk ? 0 : clk->prepare_count; |
b2476490 MT |
290 | } |
291 | ||
292 | unsigned long __clk_get_rate(struct clk *clk) | |
293 | { | |
294 | unsigned long ret; | |
295 | ||
296 | if (!clk) { | |
34e44fe8 | 297 | ret = 0; |
b2476490 MT |
298 | goto out; |
299 | } | |
300 | ||
301 | ret = clk->rate; | |
302 | ||
303 | if (clk->flags & CLK_IS_ROOT) | |
304 | goto out; | |
305 | ||
306 | if (!clk->parent) | |
34e44fe8 | 307 | ret = 0; |
b2476490 MT |
308 | |
309 | out: | |
310 | return ret; | |
311 | } | |
312 | ||
65800b2c | 313 | unsigned long __clk_get_flags(struct clk *clk) |
b2476490 | 314 | { |
2ac6b1f5 | 315 | return !clk ? 0 : clk->flags; |
b2476490 MT |
316 | } |
317 | ||
2ac6b1f5 | 318 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
319 | { |
320 | int ret; | |
321 | ||
322 | if (!clk) | |
2ac6b1f5 | 323 | return false; |
b2476490 MT |
324 | |
325 | /* | |
326 | * .is_enabled is only mandatory for clocks that gate | |
327 | * fall back to software usage counter if .is_enabled is missing | |
328 | */ | |
329 | if (!clk->ops->is_enabled) { | |
330 | ret = clk->enable_count ? 1 : 0; | |
331 | goto out; | |
332 | } | |
333 | ||
334 | ret = clk->ops->is_enabled(clk->hw); | |
335 | out: | |
2ac6b1f5 | 336 | return !!ret; |
b2476490 MT |
337 | } |
338 | ||
339 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
340 | { | |
341 | struct clk *child; | |
342 | struct clk *ret; | |
343 | struct hlist_node *tmp; | |
344 | ||
345 | if (!strcmp(clk->name, name)) | |
346 | return clk; | |
347 | ||
348 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
349 | ret = __clk_lookup_subtree(name, child); | |
350 | if (ret) | |
351 | return ret; | |
352 | } | |
353 | ||
354 | return NULL; | |
355 | } | |
356 | ||
357 | struct clk *__clk_lookup(const char *name) | |
358 | { | |
359 | struct clk *root_clk; | |
360 | struct clk *ret; | |
361 | struct hlist_node *tmp; | |
362 | ||
363 | if (!name) | |
364 | return NULL; | |
365 | ||
366 | /* search the 'proper' clk tree first */ | |
367 | hlist_for_each_entry(root_clk, tmp, &clk_root_list, child_node) { | |
368 | ret = __clk_lookup_subtree(name, root_clk); | |
369 | if (ret) | |
370 | return ret; | |
371 | } | |
372 | ||
373 | /* if not found, then search the orphan tree */ | |
374 | hlist_for_each_entry(root_clk, tmp, &clk_orphan_list, child_node) { | |
375 | ret = __clk_lookup_subtree(name, root_clk); | |
376 | if (ret) | |
377 | return ret; | |
378 | } | |
379 | ||
380 | return NULL; | |
381 | } | |
382 | ||
383 | /*** clk api ***/ | |
384 | ||
385 | void __clk_unprepare(struct clk *clk) | |
386 | { | |
387 | if (!clk) | |
388 | return; | |
389 | ||
390 | if (WARN_ON(clk->prepare_count == 0)) | |
391 | return; | |
392 | ||
393 | if (--clk->prepare_count > 0) | |
394 | return; | |
395 | ||
396 | WARN_ON(clk->enable_count > 0); | |
397 | ||
398 | if (clk->ops->unprepare) | |
399 | clk->ops->unprepare(clk->hw); | |
400 | ||
401 | __clk_unprepare(clk->parent); | |
402 | } | |
403 | ||
404 | /** | |
405 | * clk_unprepare - undo preparation of a clock source | |
406 | * @clk: the clk being unprepare | |
407 | * | |
408 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
409 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
410 | * if the operation may sleep. One example is a clk which is accessed over | |
411 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
412 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
413 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
414 | */ | |
415 | void clk_unprepare(struct clk *clk) | |
416 | { | |
417 | mutex_lock(&prepare_lock); | |
418 | __clk_unprepare(clk); | |
419 | mutex_unlock(&prepare_lock); | |
420 | } | |
421 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
422 | ||
423 | int __clk_prepare(struct clk *clk) | |
424 | { | |
425 | int ret = 0; | |
426 | ||
427 | if (!clk) | |
428 | return 0; | |
429 | ||
430 | if (clk->prepare_count == 0) { | |
431 | ret = __clk_prepare(clk->parent); | |
432 | if (ret) | |
433 | return ret; | |
434 | ||
435 | if (clk->ops->prepare) { | |
436 | ret = clk->ops->prepare(clk->hw); | |
437 | if (ret) { | |
438 | __clk_unprepare(clk->parent); | |
439 | return ret; | |
440 | } | |
441 | } | |
442 | } | |
443 | ||
444 | clk->prepare_count++; | |
445 | ||
446 | return 0; | |
447 | } | |
448 | ||
449 | /** | |
450 | * clk_prepare - prepare a clock source | |
451 | * @clk: the clk being prepared | |
452 | * | |
453 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
454 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
455 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
456 | * the complex case a clk ungate operation may require a fast and a slow part. | |
457 | * It is this reason that clk_prepare and clk_enable are not mutually | |
458 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
459 | * Returns 0 on success, -EERROR otherwise. | |
460 | */ | |
461 | int clk_prepare(struct clk *clk) | |
462 | { | |
463 | int ret; | |
464 | ||
465 | mutex_lock(&prepare_lock); | |
466 | ret = __clk_prepare(clk); | |
467 | mutex_unlock(&prepare_lock); | |
468 | ||
469 | return ret; | |
470 | } | |
471 | EXPORT_SYMBOL_GPL(clk_prepare); | |
472 | ||
473 | static void __clk_disable(struct clk *clk) | |
474 | { | |
475 | if (!clk) | |
476 | return; | |
477 | ||
e47c6a34 FW |
478 | if (WARN_ON(IS_ERR(clk))) |
479 | return; | |
480 | ||
b2476490 MT |
481 | if (WARN_ON(clk->enable_count == 0)) |
482 | return; | |
483 | ||
484 | if (--clk->enable_count > 0) | |
485 | return; | |
486 | ||
487 | if (clk->ops->disable) | |
488 | clk->ops->disable(clk->hw); | |
489 | ||
490 | __clk_disable(clk->parent); | |
491 | } | |
492 | ||
493 | /** | |
494 | * clk_disable - gate a clock | |
495 | * @clk: the clk being gated | |
496 | * | |
497 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
498 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
499 | * clk if the operation is fast and will never sleep. One example is a | |
500 | * SoC-internal clk which is controlled via simple register writes. In the | |
501 | * complex case a clk gate operation may require a fast and a slow part. It is | |
502 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
503 | * In fact clk_disable must be called before clk_unprepare. | |
504 | */ | |
505 | void clk_disable(struct clk *clk) | |
506 | { | |
507 | unsigned long flags; | |
508 | ||
509 | spin_lock_irqsave(&enable_lock, flags); | |
510 | __clk_disable(clk); | |
511 | spin_unlock_irqrestore(&enable_lock, flags); | |
512 | } | |
513 | EXPORT_SYMBOL_GPL(clk_disable); | |
514 | ||
515 | static int __clk_enable(struct clk *clk) | |
516 | { | |
517 | int ret = 0; | |
518 | ||
519 | if (!clk) | |
520 | return 0; | |
521 | ||
522 | if (WARN_ON(clk->prepare_count == 0)) | |
523 | return -ESHUTDOWN; | |
524 | ||
525 | if (clk->enable_count == 0) { | |
526 | ret = __clk_enable(clk->parent); | |
527 | ||
528 | if (ret) | |
529 | return ret; | |
530 | ||
531 | if (clk->ops->enable) { | |
532 | ret = clk->ops->enable(clk->hw); | |
533 | if (ret) { | |
534 | __clk_disable(clk->parent); | |
535 | return ret; | |
536 | } | |
537 | } | |
538 | } | |
539 | ||
540 | clk->enable_count++; | |
541 | return 0; | |
542 | } | |
543 | ||
544 | /** | |
545 | * clk_enable - ungate a clock | |
546 | * @clk: the clk being ungated | |
547 | * | |
548 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
549 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
550 | * if the operation will never sleep. One example is a SoC-internal clk which | |
551 | * is controlled via simple register writes. In the complex case a clk ungate | |
552 | * operation may require a fast and a slow part. It is this reason that | |
553 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
554 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
555 | * otherwise. | |
556 | */ | |
557 | int clk_enable(struct clk *clk) | |
558 | { | |
559 | unsigned long flags; | |
560 | int ret; | |
561 | ||
562 | spin_lock_irqsave(&enable_lock, flags); | |
563 | ret = __clk_enable(clk); | |
564 | spin_unlock_irqrestore(&enable_lock, flags); | |
565 | ||
566 | return ret; | |
567 | } | |
568 | EXPORT_SYMBOL_GPL(clk_enable); | |
569 | ||
b2476490 MT |
570 | /** |
571 | * __clk_round_rate - round the given rate for a clk | |
572 | * @clk: round the rate of this clock | |
573 | * | |
574 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
575 | */ | |
576 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
577 | { | |
81536e07 | 578 | unsigned long parent_rate = 0; |
b2476490 MT |
579 | |
580 | if (!clk) | |
2ac6b1f5 | 581 | return 0; |
b2476490 | 582 | |
f4d8af2e SG |
583 | if (!clk->ops->round_rate) { |
584 | if (clk->flags & CLK_SET_RATE_PARENT) | |
585 | return __clk_round_rate(clk->parent, rate); | |
586 | else | |
587 | return clk->rate; | |
588 | } | |
b2476490 | 589 | |
81536e07 SG |
590 | if (clk->parent) |
591 | parent_rate = clk->parent->rate; | |
592 | ||
593 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); | |
b2476490 MT |
594 | } |
595 | ||
596 | /** | |
597 | * clk_round_rate - round the given rate for a clk | |
598 | * @clk: the clk for which we are rounding a rate | |
599 | * @rate: the rate which is to be rounded | |
600 | * | |
601 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
602 | * use which is then returned. If clk doesn't support round_rate operation | |
603 | * then the parent rate is returned. | |
604 | */ | |
605 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
606 | { | |
607 | unsigned long ret; | |
608 | ||
609 | mutex_lock(&prepare_lock); | |
610 | ret = __clk_round_rate(clk, rate); | |
611 | mutex_unlock(&prepare_lock); | |
612 | ||
613 | return ret; | |
614 | } | |
615 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
616 | ||
617 | /** | |
618 | * __clk_notify - call clk notifier chain | |
619 | * @clk: struct clk * that is changing rate | |
620 | * @msg: clk notifier type (see include/linux/clk.h) | |
621 | * @old_rate: old clk rate | |
622 | * @new_rate: new clk rate | |
623 | * | |
624 | * Triggers a notifier call chain on the clk rate-change notification | |
625 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
626 | * and current rates to the notifier callback. Intended to be called by | |
627 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
628 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
629 | * a driver returns that. | |
630 | */ | |
631 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
632 | unsigned long old_rate, unsigned long new_rate) | |
633 | { | |
634 | struct clk_notifier *cn; | |
635 | struct clk_notifier_data cnd; | |
636 | int ret = NOTIFY_DONE; | |
637 | ||
638 | cnd.clk = clk; | |
639 | cnd.old_rate = old_rate; | |
640 | cnd.new_rate = new_rate; | |
641 | ||
642 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
643 | if (cn->clk == clk) { | |
644 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
645 | &cnd); | |
646 | break; | |
647 | } | |
648 | } | |
649 | ||
650 | return ret; | |
651 | } | |
652 | ||
653 | /** | |
654 | * __clk_recalc_rates | |
655 | * @clk: first clk in the subtree | |
656 | * @msg: notification type (see include/linux/clk.h) | |
657 | * | |
658 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
659 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
660 | * it is assumed that the clock will take on the rate of it's parent. | |
661 | * | |
662 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
663 | * if necessary. | |
664 | * | |
665 | * Caller must hold prepare_lock. | |
666 | */ | |
667 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
668 | { | |
669 | unsigned long old_rate; | |
670 | unsigned long parent_rate = 0; | |
671 | struct hlist_node *tmp; | |
672 | struct clk *child; | |
673 | ||
674 | old_rate = clk->rate; | |
675 | ||
676 | if (clk->parent) | |
677 | parent_rate = clk->parent->rate; | |
678 | ||
679 | if (clk->ops->recalc_rate) | |
680 | clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
681 | else | |
682 | clk->rate = parent_rate; | |
683 | ||
684 | /* | |
685 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
686 | * & ABORT_RATE_CHANGE notifiers | |
687 | */ | |
688 | if (clk->notifier_count && msg) | |
689 | __clk_notify(clk, msg, old_rate, clk->rate); | |
690 | ||
691 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
692 | __clk_recalc_rates(child, msg); | |
693 | } | |
694 | ||
a093bde2 UH |
695 | /** |
696 | * clk_get_rate - return the rate of clk | |
697 | * @clk: the clk whose rate is being returned | |
698 | * | |
699 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
700 | * is set, which means a recalc_rate will be issued. | |
701 | * If clk is NULL then returns 0. | |
702 | */ | |
703 | unsigned long clk_get_rate(struct clk *clk) | |
704 | { | |
705 | unsigned long rate; | |
706 | ||
707 | mutex_lock(&prepare_lock); | |
708 | ||
709 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
710 | __clk_recalc_rates(clk, 0); | |
711 | ||
712 | rate = __clk_get_rate(clk); | |
713 | mutex_unlock(&prepare_lock); | |
714 | ||
715 | return rate; | |
716 | } | |
717 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
718 | ||
b2476490 MT |
719 | /** |
720 | * __clk_speculate_rates | |
721 | * @clk: first clk in the subtree | |
722 | * @parent_rate: the "future" rate of clk's parent | |
723 | * | |
724 | * Walks the subtree of clks starting with clk, speculating rates as it | |
725 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
726 | * | |
727 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
728 | * pre-rate change notifications and returns early if no clks in the | |
729 | * subtree have subscribed to the notifications. Note that if a clk does not | |
730 | * implement the .recalc_rate callback then it is assumed that the clock will | |
731 | * take on the rate of it's parent. | |
732 | * | |
733 | * Caller must hold prepare_lock. | |
734 | */ | |
735 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
736 | { | |
737 | struct hlist_node *tmp; | |
738 | struct clk *child; | |
739 | unsigned long new_rate; | |
740 | int ret = NOTIFY_DONE; | |
741 | ||
742 | if (clk->ops->recalc_rate) | |
743 | new_rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
744 | else | |
745 | new_rate = parent_rate; | |
746 | ||
747 | /* abort the rate change if a driver returns NOTIFY_BAD */ | |
748 | if (clk->notifier_count) | |
749 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
750 | ||
751 | if (ret == NOTIFY_BAD) | |
752 | goto out; | |
753 | ||
754 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
755 | ret = __clk_speculate_rates(child, new_rate); | |
756 | if (ret == NOTIFY_BAD) | |
757 | break; | |
758 | } | |
759 | ||
760 | out: | |
761 | return ret; | |
762 | } | |
763 | ||
764 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate) | |
765 | { | |
766 | struct clk *child; | |
767 | struct hlist_node *tmp; | |
768 | ||
769 | clk->new_rate = new_rate; | |
770 | ||
771 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
772 | if (child->ops->recalc_rate) | |
773 | child->new_rate = child->ops->recalc_rate(child->hw, new_rate); | |
774 | else | |
775 | child->new_rate = new_rate; | |
776 | clk_calc_subtree(child, child->new_rate); | |
777 | } | |
778 | } | |
779 | ||
780 | /* | |
781 | * calculate the new rates returning the topmost clock that has to be | |
782 | * changed. | |
783 | */ | |
784 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
785 | { | |
786 | struct clk *top = clk; | |
81536e07 | 787 | unsigned long best_parent_rate = 0; |
b2476490 MT |
788 | unsigned long new_rate; |
789 | ||
7452b219 MT |
790 | /* sanity */ |
791 | if (IS_ERR_OR_NULL(clk)) | |
792 | return NULL; | |
793 | ||
63f5c3b2 MT |
794 | /* save parent rate, if it exists */ |
795 | if (clk->parent) | |
796 | best_parent_rate = clk->parent->rate; | |
797 | ||
7452b219 MT |
798 | /* never propagate up to the parent */ |
799 | if (!(clk->flags & CLK_SET_RATE_PARENT)) { | |
800 | if (!clk->ops->round_rate) { | |
801 | clk->new_rate = clk->rate; | |
802 | return NULL; | |
7452b219 | 803 | } |
63f5c3b2 MT |
804 | new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); |
805 | goto out; | |
7452b219 MT |
806 | } |
807 | ||
808 | /* need clk->parent from here on out */ | |
809 | if (!clk->parent) { | |
810 | pr_debug("%s: %s has NULL parent\n", __func__, clk->name); | |
b2476490 MT |
811 | return NULL; |
812 | } | |
813 | ||
7452b219 | 814 | if (!clk->ops->round_rate) { |
b2476490 | 815 | top = clk_calc_new_rates(clk->parent, rate); |
1b2f9903 | 816 | new_rate = clk->parent->new_rate; |
b2476490 MT |
817 | |
818 | goto out; | |
819 | } | |
820 | ||
7452b219 | 821 | new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); |
b2476490 MT |
822 | |
823 | if (best_parent_rate != clk->parent->rate) { | |
824 | top = clk_calc_new_rates(clk->parent, best_parent_rate); | |
825 | ||
826 | goto out; | |
827 | } | |
828 | ||
829 | out: | |
830 | clk_calc_subtree(clk, new_rate); | |
831 | ||
832 | return top; | |
833 | } | |
834 | ||
835 | /* | |
836 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
837 | * so that in case of an error we can walk down the whole tree again and | |
838 | * abort the change. | |
839 | */ | |
840 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
841 | { | |
842 | struct hlist_node *tmp; | |
843 | struct clk *child, *fail_clk = NULL; | |
844 | int ret = NOTIFY_DONE; | |
845 | ||
846 | if (clk->rate == clk->new_rate) | |
847 | return 0; | |
848 | ||
849 | if (clk->notifier_count) { | |
850 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
851 | if (ret == NOTIFY_BAD) | |
852 | fail_clk = clk; | |
853 | } | |
854 | ||
855 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
856 | clk = clk_propagate_rate_change(child, event); | |
857 | if (clk) | |
858 | fail_clk = clk; | |
859 | } | |
860 | ||
861 | return fail_clk; | |
862 | } | |
863 | ||
864 | /* | |
865 | * walk down a subtree and set the new rates notifying the rate | |
866 | * change on the way | |
867 | */ | |
868 | static void clk_change_rate(struct clk *clk) | |
869 | { | |
870 | struct clk *child; | |
871 | unsigned long old_rate; | |
bf47b4fd | 872 | unsigned long best_parent_rate = 0; |
b2476490 MT |
873 | struct hlist_node *tmp; |
874 | ||
875 | old_rate = clk->rate; | |
876 | ||
bf47b4fd PM |
877 | if (clk->parent) |
878 | best_parent_rate = clk->parent->rate; | |
879 | ||
b2476490 | 880 | if (clk->ops->set_rate) |
bf47b4fd | 881 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 MT |
882 | |
883 | if (clk->ops->recalc_rate) | |
bf47b4fd | 884 | clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate); |
b2476490 | 885 | else |
bf47b4fd | 886 | clk->rate = best_parent_rate; |
b2476490 MT |
887 | |
888 | if (clk->notifier_count && old_rate != clk->rate) | |
889 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
890 | ||
891 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
892 | clk_change_rate(child); | |
893 | } | |
894 | ||
895 | /** | |
896 | * clk_set_rate - specify a new rate for clk | |
897 | * @clk: the clk whose rate is being changed | |
898 | * @rate: the new rate for clk | |
899 | * | |
5654dc94 | 900 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 901 | * |
5654dc94 MT |
902 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
903 | * propagate up to clk's parent; whether or not this happens depends on the | |
904 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
905 | * after calling .round_rate then upstream parent propagation is ignored. If | |
906 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
907 | * up to clk's parent and set it's rate. Upward propagation will continue | |
908 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or | |
909 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 910 | * |
5654dc94 MT |
911 | * Rate changes are accomplished via tree traversal that also recalculates the |
912 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
913 | * |
914 | * Returns 0 on success, -EERROR otherwise. | |
915 | */ | |
916 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
917 | { | |
918 | struct clk *top, *fail_clk; | |
919 | int ret = 0; | |
920 | ||
921 | /* prevent racing with updates to the clock topology */ | |
922 | mutex_lock(&prepare_lock); | |
923 | ||
924 | /* bail early if nothing to do */ | |
925 | if (rate == clk->rate) | |
926 | goto out; | |
927 | ||
7e0fa1b5 | 928 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
929 | ret = -EBUSY; |
930 | goto out; | |
931 | } | |
932 | ||
b2476490 MT |
933 | /* calculate new rates and get the topmost changed clock */ |
934 | top = clk_calc_new_rates(clk, rate); | |
935 | if (!top) { | |
936 | ret = -EINVAL; | |
937 | goto out; | |
938 | } | |
939 | ||
940 | /* notify that we are about to change rates */ | |
941 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
942 | if (fail_clk) { | |
943 | pr_warn("%s: failed to set %s rate\n", __func__, | |
944 | fail_clk->name); | |
945 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
946 | ret = -EBUSY; | |
947 | goto out; | |
948 | } | |
949 | ||
950 | /* change the rates */ | |
951 | clk_change_rate(top); | |
952 | ||
953 | mutex_unlock(&prepare_lock); | |
954 | ||
955 | return 0; | |
956 | out: | |
957 | mutex_unlock(&prepare_lock); | |
958 | ||
959 | return ret; | |
960 | } | |
961 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
962 | ||
963 | /** | |
964 | * clk_get_parent - return the parent of a clk | |
965 | * @clk: the clk whose parent gets returned | |
966 | * | |
967 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
968 | */ | |
969 | struct clk *clk_get_parent(struct clk *clk) | |
970 | { | |
971 | struct clk *parent; | |
972 | ||
973 | mutex_lock(&prepare_lock); | |
974 | parent = __clk_get_parent(clk); | |
975 | mutex_unlock(&prepare_lock); | |
976 | ||
977 | return parent; | |
978 | } | |
979 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
980 | ||
981 | /* | |
982 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
983 | * optional for single-parent clocks. Always call .get_parent if it is | |
984 | * available and WARN if it is missing for multi-parent clocks. | |
985 | * | |
986 | * For single-parent clocks without .get_parent, first check to see if the | |
987 | * .parents array exists, and if so use it to avoid an expensive tree | |
988 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
989 | */ | |
990 | static struct clk *__clk_init_parent(struct clk *clk) | |
991 | { | |
992 | struct clk *ret = NULL; | |
993 | u8 index; | |
994 | ||
995 | /* handle the trivial cases */ | |
996 | ||
997 | if (!clk->num_parents) | |
998 | goto out; | |
999 | ||
1000 | if (clk->num_parents == 1) { | |
1001 | if (IS_ERR_OR_NULL(clk->parent)) | |
1002 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); | |
1003 | ret = clk->parent; | |
1004 | goto out; | |
1005 | } | |
1006 | ||
1007 | if (!clk->ops->get_parent) { | |
1008 | WARN(!clk->ops->get_parent, | |
1009 | "%s: multi-parent clocks must implement .get_parent\n", | |
1010 | __func__); | |
1011 | goto out; | |
1012 | }; | |
1013 | ||
1014 | /* | |
1015 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1016 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1017 | * clk->parent here; that is done by the calling function | |
1018 | */ | |
1019 | ||
1020 | index = clk->ops->get_parent(clk->hw); | |
1021 | ||
1022 | if (!clk->parents) | |
1023 | clk->parents = | |
7975059d | 1024 | kzalloc((sizeof(struct clk*) * clk->num_parents), |
b2476490 MT |
1025 | GFP_KERNEL); |
1026 | ||
1027 | if (!clk->parents) | |
1028 | ret = __clk_lookup(clk->parent_names[index]); | |
1029 | else if (!clk->parents[index]) | |
1030 | ret = clk->parents[index] = | |
1031 | __clk_lookup(clk->parent_names[index]); | |
1032 | else | |
1033 | ret = clk->parents[index]; | |
1034 | ||
1035 | out: | |
1036 | return ret; | |
1037 | } | |
1038 | ||
1039 | void __clk_reparent(struct clk *clk, struct clk *new_parent) | |
1040 | { | |
1041 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
1042 | struct dentry *d; | |
1043 | struct dentry *new_parent_d; | |
1044 | #endif | |
1045 | ||
1046 | if (!clk || !new_parent) | |
1047 | return; | |
1048 | ||
1049 | hlist_del(&clk->child_node); | |
1050 | ||
1051 | if (new_parent) | |
1052 | hlist_add_head(&clk->child_node, &new_parent->children); | |
1053 | else | |
1054 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1055 | ||
1056 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
1057 | if (!inited) | |
1058 | goto out; | |
1059 | ||
1060 | if (new_parent) | |
1061 | new_parent_d = new_parent->dentry; | |
1062 | else | |
1063 | new_parent_d = orphandir; | |
1064 | ||
1065 | d = debugfs_rename(clk->dentry->d_parent, clk->dentry, | |
1066 | new_parent_d, clk->name); | |
1067 | if (d) | |
1068 | clk->dentry = d; | |
1069 | else | |
1070 | pr_debug("%s: failed to rename debugfs entry for %s\n", | |
1071 | __func__, clk->name); | |
1072 | out: | |
1073 | #endif | |
1074 | ||
1075 | clk->parent = new_parent; | |
1076 | ||
1077 | __clk_recalc_rates(clk, POST_RATE_CHANGE); | |
1078 | } | |
1079 | ||
1080 | static int __clk_set_parent(struct clk *clk, struct clk *parent) | |
1081 | { | |
1082 | struct clk *old_parent; | |
1083 | unsigned long flags; | |
1084 | int ret = -EINVAL; | |
1085 | u8 i; | |
1086 | ||
1087 | old_parent = clk->parent; | |
1088 | ||
863b1327 | 1089 | if (!clk->parents) |
7975059d RN |
1090 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), |
1091 | GFP_KERNEL); | |
b2476490 MT |
1092 | |
1093 | /* | |
863b1327 RN |
1094 | * find index of new parent clock using cached parent ptrs, |
1095 | * or if not yet cached, use string name comparison and cache | |
1096 | * them now to avoid future calls to __clk_lookup. | |
b2476490 | 1097 | */ |
863b1327 RN |
1098 | for (i = 0; i < clk->num_parents; i++) { |
1099 | if (clk->parents && clk->parents[i] == parent) | |
1100 | break; | |
1101 | else if (!strcmp(clk->parent_names[i], parent->name)) { | |
1102 | if (clk->parents) | |
1103 | clk->parents[i] = __clk_lookup(parent->name); | |
1104 | break; | |
1105 | } | |
1106 | } | |
b2476490 MT |
1107 | |
1108 | if (i == clk->num_parents) { | |
1109 | pr_debug("%s: clock %s is not a possible parent of clock %s\n", | |
1110 | __func__, parent->name, clk->name); | |
1111 | goto out; | |
1112 | } | |
1113 | ||
1114 | /* migrate prepare and enable */ | |
1115 | if (clk->prepare_count) | |
1116 | __clk_prepare(parent); | |
1117 | ||
1118 | /* FIXME replace with clk_is_enabled(clk) someday */ | |
1119 | spin_lock_irqsave(&enable_lock, flags); | |
1120 | if (clk->enable_count) | |
1121 | __clk_enable(parent); | |
1122 | spin_unlock_irqrestore(&enable_lock, flags); | |
1123 | ||
1124 | /* change clock input source */ | |
1125 | ret = clk->ops->set_parent(clk->hw, i); | |
1126 | ||
1127 | /* clean up old prepare and enable */ | |
1128 | spin_lock_irqsave(&enable_lock, flags); | |
1129 | if (clk->enable_count) | |
1130 | __clk_disable(old_parent); | |
1131 | spin_unlock_irqrestore(&enable_lock, flags); | |
1132 | ||
1133 | if (clk->prepare_count) | |
1134 | __clk_unprepare(old_parent); | |
1135 | ||
1136 | out: | |
1137 | return ret; | |
1138 | } | |
1139 | ||
1140 | /** | |
1141 | * clk_set_parent - switch the parent of a mux clk | |
1142 | * @clk: the mux clk whose input we are switching | |
1143 | * @parent: the new input to clk | |
1144 | * | |
1145 | * Re-parent clk to use parent as it's new input source. If clk has the | |
1146 | * CLK_SET_PARENT_GATE flag set then clk must be gated for this | |
1147 | * operation to succeed. After successfully changing clk's parent | |
1148 | * clk_set_parent will update the clk topology, sysfs topology and | |
1149 | * propagate rate recalculation via __clk_recalc_rates. Returns 0 on | |
1150 | * success, -EERROR otherwise. | |
1151 | */ | |
1152 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
1153 | { | |
1154 | int ret = 0; | |
1155 | ||
1156 | if (!clk || !clk->ops) | |
1157 | return -EINVAL; | |
1158 | ||
1159 | if (!clk->ops->set_parent) | |
1160 | return -ENOSYS; | |
1161 | ||
1162 | /* prevent racing with updates to the clock topology */ | |
1163 | mutex_lock(&prepare_lock); | |
1164 | ||
1165 | if (clk->parent == parent) | |
1166 | goto out; | |
1167 | ||
1168 | /* propagate PRE_RATE_CHANGE notifications */ | |
1169 | if (clk->notifier_count) | |
1170 | ret = __clk_speculate_rates(clk, parent->rate); | |
1171 | ||
1172 | /* abort if a driver objects */ | |
1173 | if (ret == NOTIFY_STOP) | |
1174 | goto out; | |
1175 | ||
1176 | /* only re-parent if the clock is not in use */ | |
1177 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) | |
1178 | ret = -EBUSY; | |
1179 | else | |
1180 | ret = __clk_set_parent(clk, parent); | |
1181 | ||
1182 | /* propagate ABORT_RATE_CHANGE if .set_parent failed */ | |
1183 | if (ret) { | |
1184 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); | |
1185 | goto out; | |
1186 | } | |
1187 | ||
1188 | /* propagate rate recalculation downstream */ | |
1189 | __clk_reparent(clk, parent); | |
1190 | ||
1191 | out: | |
1192 | mutex_unlock(&prepare_lock); | |
1193 | ||
1194 | return ret; | |
1195 | } | |
1196 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1197 | ||
1198 | /** | |
1199 | * __clk_init - initialize the data structures in a struct clk | |
1200 | * @dev: device initializing this clk, placeholder for now | |
1201 | * @clk: clk being initialized | |
1202 | * | |
1203 | * Initializes the lists in struct clk, queries the hardware for the | |
1204 | * parent and rate and sets them both. | |
b2476490 | 1205 | */ |
d1302a36 | 1206 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1207 | { |
d1302a36 | 1208 | int i, ret = 0; |
b2476490 MT |
1209 | struct clk *orphan; |
1210 | struct hlist_node *tmp, *tmp2; | |
1211 | ||
1212 | if (!clk) | |
d1302a36 | 1213 | return -EINVAL; |
b2476490 MT |
1214 | |
1215 | mutex_lock(&prepare_lock); | |
1216 | ||
1217 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1218 | if (__clk_lookup(clk->name)) { |
1219 | pr_debug("%s: clk %s already initialized\n", | |
1220 | __func__, clk->name); | |
1221 | ret = -EEXIST; | |
b2476490 | 1222 | goto out; |
d1302a36 | 1223 | } |
b2476490 | 1224 | |
d4d7e3dd MT |
1225 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1226 | if (clk->ops->set_rate && | |
1227 | !(clk->ops->round_rate && clk->ops->recalc_rate)) { | |
1228 | pr_warning("%s: %s must implement .round_rate & .recalc_rate\n", | |
1229 | __func__, clk->name); | |
d1302a36 | 1230 | ret = -EINVAL; |
d4d7e3dd MT |
1231 | goto out; |
1232 | } | |
1233 | ||
1234 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1235 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1236 | __func__, clk->name); | |
d1302a36 | 1237 | ret = -EINVAL; |
d4d7e3dd MT |
1238 | goto out; |
1239 | } | |
1240 | ||
b2476490 MT |
1241 | /* throw a WARN if any entries in parent_names are NULL */ |
1242 | for (i = 0; i < clk->num_parents; i++) | |
1243 | WARN(!clk->parent_names[i], | |
1244 | "%s: invalid NULL in %s's .parent_names\n", | |
1245 | __func__, clk->name); | |
1246 | ||
1247 | /* | |
1248 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1249 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1250 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1251 | * must always check for a NULL pointer and try to populate it if | |
1252 | * necessary. | |
1253 | * | |
1254 | * If clk->parents is not NULL we skip this entire block. This allows | |
1255 | * for clock drivers to statically initialize clk->parents. | |
1256 | */ | |
9ca1c5a4 RN |
1257 | if (clk->num_parents > 1 && !clk->parents) { |
1258 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), | |
b2476490 MT |
1259 | GFP_KERNEL); |
1260 | /* | |
1261 | * __clk_lookup returns NULL for parents that have not been | |
1262 | * clk_init'd; thus any access to clk->parents[] must check | |
1263 | * for a NULL pointer. We can always perform lazy lookups for | |
1264 | * missing parents later on. | |
1265 | */ | |
1266 | if (clk->parents) | |
1267 | for (i = 0; i < clk->num_parents; i++) | |
1268 | clk->parents[i] = | |
1269 | __clk_lookup(clk->parent_names[i]); | |
1270 | } | |
1271 | ||
1272 | clk->parent = __clk_init_parent(clk); | |
1273 | ||
1274 | /* | |
1275 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1276 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1277 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1278 | * clk list. | |
1279 | * | |
1280 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1281 | * clocks and re-parent any that are children of the clock currently | |
1282 | * being clk_init'd. | |
1283 | */ | |
1284 | if (clk->parent) | |
1285 | hlist_add_head(&clk->child_node, | |
1286 | &clk->parent->children); | |
1287 | else if (clk->flags & CLK_IS_ROOT) | |
1288 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1289 | else | |
1290 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1291 | ||
1292 | /* | |
1293 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1294 | * simple clocks and lazy developers the default fallback is to use the | |
1295 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1296 | * then rate is set to zero. | |
1297 | */ | |
1298 | if (clk->ops->recalc_rate) | |
1299 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1300 | __clk_get_rate(clk->parent)); | |
1301 | else if (clk->parent) | |
1302 | clk->rate = clk->parent->rate; | |
1303 | else | |
1304 | clk->rate = 0; | |
1305 | ||
1306 | /* | |
1307 | * walk the list of orphan clocks and reparent any that are children of | |
1308 | * this clock | |
1309 | */ | |
1f61e5f1 MF |
1310 | hlist_for_each_entry_safe(orphan, tmp, tmp2, &clk_orphan_list, child_node) { |
1311 | if (orphan->ops->get_parent) { | |
1312 | i = orphan->ops->get_parent(orphan->hw); | |
1313 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1314 | __clk_reparent(orphan, clk); | |
1315 | continue; | |
1316 | } | |
1317 | ||
b2476490 MT |
1318 | for (i = 0; i < orphan->num_parents; i++) |
1319 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1320 | __clk_reparent(orphan, clk); | |
1321 | break; | |
1322 | } | |
1f61e5f1 | 1323 | } |
b2476490 MT |
1324 | |
1325 | /* | |
1326 | * optional platform-specific magic | |
1327 | * | |
1328 | * The .init callback is not used by any of the basic clock types, but | |
1329 | * exists for weird hardware that must perform initialization magic. | |
1330 | * Please consider other ways of solving initialization problems before | |
1331 | * using this callback, as it's use is discouraged. | |
1332 | */ | |
1333 | if (clk->ops->init) | |
1334 | clk->ops->init(clk->hw); | |
1335 | ||
1336 | clk_debug_register(clk); | |
1337 | ||
1338 | out: | |
1339 | mutex_unlock(&prepare_lock); | |
1340 | ||
d1302a36 | 1341 | return ret; |
b2476490 MT |
1342 | } |
1343 | ||
0197b3ea SK |
1344 | /** |
1345 | * __clk_register - register a clock and return a cookie. | |
1346 | * | |
1347 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1348 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1349 | * of the struct clk need to be initialized. | |
1350 | * | |
1351 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1352 | * data. | |
1353 | * | |
1354 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1355 | * very large numbers of clocks that need to be statically initialized. It is | |
1356 | * a layering violation to include clk-private.h from any code which implements | |
1357 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
1358 | * separate C file from the logic that implements it's operations. Returns 0 | |
1359 | * on success, otherwise an error code. | |
1360 | */ | |
1361 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
1362 | { | |
1363 | int ret; | |
1364 | struct clk *clk; | |
1365 | ||
1366 | clk = hw->clk; | |
1367 | clk->name = hw->init->name; | |
1368 | clk->ops = hw->init->ops; | |
1369 | clk->hw = hw; | |
1370 | clk->flags = hw->init->flags; | |
1371 | clk->parent_names = hw->init->parent_names; | |
1372 | clk->num_parents = hw->init->num_parents; | |
1373 | ||
1374 | ret = __clk_init(dev, clk); | |
1375 | if (ret) | |
1376 | return ERR_PTR(ret); | |
1377 | ||
1378 | return clk; | |
1379 | } | |
1380 | EXPORT_SYMBOL_GPL(__clk_register); | |
1381 | ||
46c8773a | 1382 | static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk) |
b2476490 | 1383 | { |
d1302a36 | 1384 | int i, ret; |
b2476490 | 1385 | |
0197b3ea SK |
1386 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
1387 | if (!clk->name) { | |
1388 | pr_err("%s: could not allocate clk->name\n", __func__); | |
1389 | ret = -ENOMEM; | |
1390 | goto fail_name; | |
1391 | } | |
1392 | clk->ops = hw->init->ops; | |
b2476490 | 1393 | clk->hw = hw; |
0197b3ea SK |
1394 | clk->flags = hw->init->flags; |
1395 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
1396 | hw->clk = clk; |
1397 | ||
d1302a36 | 1398 | /* allocate local copy in case parent_names is __initdata */ |
0197b3ea | 1399 | clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents), |
d1302a36 MT |
1400 | GFP_KERNEL); |
1401 | ||
1402 | if (!clk->parent_names) { | |
1403 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
1404 | ret = -ENOMEM; | |
1405 | goto fail_parent_names; | |
1406 | } | |
1407 | ||
1408 | ||
1409 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea SK |
1410 | for (i = 0; i < clk->num_parents; i++) { |
1411 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], | |
1412 | GFP_KERNEL); | |
d1302a36 MT |
1413 | if (!clk->parent_names[i]) { |
1414 | pr_err("%s: could not copy parent_names\n", __func__); | |
1415 | ret = -ENOMEM; | |
1416 | goto fail_parent_names_copy; | |
1417 | } | |
1418 | } | |
1419 | ||
1420 | ret = __clk_init(dev, clk); | |
1421 | if (!ret) | |
46c8773a | 1422 | return 0; |
b2476490 | 1423 | |
d1302a36 MT |
1424 | fail_parent_names_copy: |
1425 | while (--i >= 0) | |
1426 | kfree(clk->parent_names[i]); | |
1427 | kfree(clk->parent_names); | |
1428 | fail_parent_names: | |
0197b3ea SK |
1429 | kfree(clk->name); |
1430 | fail_name: | |
46c8773a SB |
1431 | return ret; |
1432 | } | |
1433 | ||
1434 | /** | |
1435 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
1436 | * @dev: device that is registering this clock | |
1437 | * @hw: link to hardware-specific clock data | |
1438 | * | |
1439 | * clk_register is the primary interface for populating the clock tree with new | |
1440 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
1441 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
1442 | * rest of the clock API. In the event of an error clk_register will return an | |
1443 | * error code; drivers must test for an error code after calling clk_register. | |
1444 | */ | |
1445 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
1446 | { | |
1447 | int ret; | |
1448 | struct clk *clk; | |
1449 | ||
1450 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
1451 | if (!clk) { | |
1452 | pr_err("%s: could not allocate clk\n", __func__); | |
1453 | ret = -ENOMEM; | |
1454 | goto fail_out; | |
1455 | } | |
1456 | ||
1457 | ret = _clk_register(dev, hw, clk); | |
1458 | if (!ret) | |
1459 | return clk; | |
1460 | ||
d1302a36 MT |
1461 | kfree(clk); |
1462 | fail_out: | |
1463 | return ERR_PTR(ret); | |
b2476490 MT |
1464 | } |
1465 | EXPORT_SYMBOL_GPL(clk_register); | |
1466 | ||
1df5c939 MB |
1467 | /** |
1468 | * clk_unregister - unregister a currently registered clock | |
1469 | * @clk: clock to unregister | |
1470 | * | |
1471 | * Currently unimplemented. | |
1472 | */ | |
1473 | void clk_unregister(struct clk *clk) {} | |
1474 | EXPORT_SYMBOL_GPL(clk_unregister); | |
1475 | ||
46c8773a SB |
1476 | static void devm_clk_release(struct device *dev, void *res) |
1477 | { | |
1478 | clk_unregister(res); | |
1479 | } | |
1480 | ||
1481 | /** | |
1482 | * devm_clk_register - resource managed clk_register() | |
1483 | * @dev: device that is registering this clock | |
1484 | * @hw: link to hardware-specific clock data | |
1485 | * | |
1486 | * Managed clk_register(). Clocks returned from this function are | |
1487 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
1488 | * more information. | |
1489 | */ | |
1490 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
1491 | { | |
1492 | struct clk *clk; | |
1493 | int ret; | |
1494 | ||
1495 | clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL); | |
1496 | if (!clk) | |
1497 | return ERR_PTR(-ENOMEM); | |
1498 | ||
1499 | ret = _clk_register(dev, hw, clk); | |
1500 | if (!ret) { | |
1501 | devres_add(dev, clk); | |
1502 | } else { | |
1503 | devres_free(clk); | |
1504 | clk = ERR_PTR(ret); | |
1505 | } | |
1506 | ||
1507 | return clk; | |
1508 | } | |
1509 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
1510 | ||
1511 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
1512 | { | |
1513 | struct clk *c = res; | |
1514 | if (WARN_ON(!c)) | |
1515 | return 0; | |
1516 | return c == data; | |
1517 | } | |
1518 | ||
1519 | /** | |
1520 | * devm_clk_unregister - resource managed clk_unregister() | |
1521 | * @clk: clock to unregister | |
1522 | * | |
1523 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
1524 | * this function will not need to be called and the resource management | |
1525 | * code will ensure that the resource is freed. | |
1526 | */ | |
1527 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
1528 | { | |
1529 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
1530 | } | |
1531 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
1532 | ||
b2476490 MT |
1533 | /*** clk rate change notifiers ***/ |
1534 | ||
1535 | /** | |
1536 | * clk_notifier_register - add a clk rate change notifier | |
1537 | * @clk: struct clk * to watch | |
1538 | * @nb: struct notifier_block * with callback info | |
1539 | * | |
1540 | * Request notification when clk's rate changes. This uses an SRCU | |
1541 | * notifier because we want it to block and notifier unregistrations are | |
1542 | * uncommon. The callbacks associated with the notifier must not | |
1543 | * re-enter into the clk framework by calling any top-level clk APIs; | |
1544 | * this will cause a nested prepare_lock mutex. | |
1545 | * | |
1546 | * Pre-change notifier callbacks will be passed the current, pre-change | |
1547 | * rate of the clk via struct clk_notifier_data.old_rate. The new, | |
1548 | * post-change rate of the clk is passed via struct | |
1549 | * clk_notifier_data.new_rate. | |
1550 | * | |
1551 | * Post-change notifiers will pass the now-current, post-change rate of | |
1552 | * the clk in both struct clk_notifier_data.old_rate and struct | |
1553 | * clk_notifier_data.new_rate. | |
1554 | * | |
1555 | * Abort-change notifiers are effectively the opposite of pre-change | |
1556 | * notifiers: the original pre-change clk rate is passed in via struct | |
1557 | * clk_notifier_data.new_rate and the failed post-change rate is passed | |
1558 | * in via struct clk_notifier_data.old_rate. | |
1559 | * | |
1560 | * clk_notifier_register() must be called from non-atomic context. | |
1561 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
1562 | * allocation failure; otherwise, passes along the return value of | |
1563 | * srcu_notifier_chain_register(). | |
1564 | */ | |
1565 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
1566 | { | |
1567 | struct clk_notifier *cn; | |
1568 | int ret = -ENOMEM; | |
1569 | ||
1570 | if (!clk || !nb) | |
1571 | return -EINVAL; | |
1572 | ||
1573 | mutex_lock(&prepare_lock); | |
1574 | ||
1575 | /* search the list of notifiers for this clk */ | |
1576 | list_for_each_entry(cn, &clk_notifier_list, node) | |
1577 | if (cn->clk == clk) | |
1578 | break; | |
1579 | ||
1580 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
1581 | if (cn->clk != clk) { | |
1582 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
1583 | if (!cn) | |
1584 | goto out; | |
1585 | ||
1586 | cn->clk = clk; | |
1587 | srcu_init_notifier_head(&cn->notifier_head); | |
1588 | ||
1589 | list_add(&cn->node, &clk_notifier_list); | |
1590 | } | |
1591 | ||
1592 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
1593 | ||
1594 | clk->notifier_count++; | |
1595 | ||
1596 | out: | |
1597 | mutex_unlock(&prepare_lock); | |
1598 | ||
1599 | return ret; | |
1600 | } | |
1601 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
1602 | ||
1603 | /** | |
1604 | * clk_notifier_unregister - remove a clk rate change notifier | |
1605 | * @clk: struct clk * | |
1606 | * @nb: struct notifier_block * with callback info | |
1607 | * | |
1608 | * Request no further notification for changes to 'clk' and frees memory | |
1609 | * allocated in clk_notifier_register. | |
1610 | * | |
1611 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
1612 | * along the return value of srcu_notifier_chain_unregister(). | |
1613 | */ | |
1614 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
1615 | { | |
1616 | struct clk_notifier *cn = NULL; | |
1617 | int ret = -EINVAL; | |
1618 | ||
1619 | if (!clk || !nb) | |
1620 | return -EINVAL; | |
1621 | ||
1622 | mutex_lock(&prepare_lock); | |
1623 | ||
1624 | list_for_each_entry(cn, &clk_notifier_list, node) | |
1625 | if (cn->clk == clk) | |
1626 | break; | |
1627 | ||
1628 | if (cn->clk == clk) { | |
1629 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
1630 | ||
1631 | clk->notifier_count--; | |
1632 | ||
1633 | /* XXX the notifier code should handle this better */ | |
1634 | if (!cn->notifier_head.head) { | |
1635 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
1636 | kfree(cn); | |
1637 | } | |
1638 | ||
1639 | } else { | |
1640 | ret = -ENOENT; | |
1641 | } | |
1642 | ||
1643 | mutex_unlock(&prepare_lock); | |
1644 | ||
1645 | return ret; | |
1646 | } | |
1647 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
1648 | |
1649 | #ifdef CONFIG_OF | |
1650 | /** | |
1651 | * struct of_clk_provider - Clock provider registration structure | |
1652 | * @link: Entry in global list of clock providers | |
1653 | * @node: Pointer to device tree node of clock provider | |
1654 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
1655 | * given clock specifier | |
1656 | * @data: context pointer to be passed into @get callback | |
1657 | */ | |
1658 | struct of_clk_provider { | |
1659 | struct list_head link; | |
1660 | ||
1661 | struct device_node *node; | |
1662 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
1663 | void *data; | |
1664 | }; | |
1665 | ||
1666 | static LIST_HEAD(of_clk_providers); | |
1667 | static DEFINE_MUTEX(of_clk_lock); | |
1668 | ||
1669 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
1670 | void *data) | |
1671 | { | |
1672 | return data; | |
1673 | } | |
1674 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
1675 | ||
494bfec9 SG |
1676 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
1677 | { | |
1678 | struct clk_onecell_data *clk_data = data; | |
1679 | unsigned int idx = clkspec->args[0]; | |
1680 | ||
1681 | if (idx >= clk_data->clk_num) { | |
1682 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
1683 | return ERR_PTR(-EINVAL); | |
1684 | } | |
1685 | ||
1686 | return clk_data->clks[idx]; | |
1687 | } | |
1688 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
1689 | ||
766e6a4e GL |
1690 | /** |
1691 | * of_clk_add_provider() - Register a clock provider for a node | |
1692 | * @np: Device node pointer associated with clock provider | |
1693 | * @clk_src_get: callback for decoding clock | |
1694 | * @data: context pointer for @clk_src_get callback. | |
1695 | */ | |
1696 | int of_clk_add_provider(struct device_node *np, | |
1697 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
1698 | void *data), | |
1699 | void *data) | |
1700 | { | |
1701 | struct of_clk_provider *cp; | |
1702 | ||
1703 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
1704 | if (!cp) | |
1705 | return -ENOMEM; | |
1706 | ||
1707 | cp->node = of_node_get(np); | |
1708 | cp->data = data; | |
1709 | cp->get = clk_src_get; | |
1710 | ||
1711 | mutex_lock(&of_clk_lock); | |
1712 | list_add(&cp->link, &of_clk_providers); | |
1713 | mutex_unlock(&of_clk_lock); | |
1714 | pr_debug("Added clock from %s\n", np->full_name); | |
1715 | ||
1716 | return 0; | |
1717 | } | |
1718 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
1719 | ||
1720 | /** | |
1721 | * of_clk_del_provider() - Remove a previously registered clock provider | |
1722 | * @np: Device node pointer associated with clock provider | |
1723 | */ | |
1724 | void of_clk_del_provider(struct device_node *np) | |
1725 | { | |
1726 | struct of_clk_provider *cp; | |
1727 | ||
1728 | mutex_lock(&of_clk_lock); | |
1729 | list_for_each_entry(cp, &of_clk_providers, link) { | |
1730 | if (cp->node == np) { | |
1731 | list_del(&cp->link); | |
1732 | of_node_put(cp->node); | |
1733 | kfree(cp); | |
1734 | break; | |
1735 | } | |
1736 | } | |
1737 | mutex_unlock(&of_clk_lock); | |
1738 | } | |
1739 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
1740 | ||
1741 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
1742 | { | |
1743 | struct of_clk_provider *provider; | |
1744 | struct clk *clk = ERR_PTR(-ENOENT); | |
1745 | ||
1746 | /* Check if we have such a provider in our array */ | |
1747 | mutex_lock(&of_clk_lock); | |
1748 | list_for_each_entry(provider, &of_clk_providers, link) { | |
1749 | if (provider->node == clkspec->np) | |
1750 | clk = provider->get(clkspec, provider->data); | |
1751 | if (!IS_ERR(clk)) | |
1752 | break; | |
1753 | } | |
1754 | mutex_unlock(&of_clk_lock); | |
1755 | ||
1756 | return clk; | |
1757 | } | |
1758 | ||
1759 | const char *of_clk_get_parent_name(struct device_node *np, int index) | |
1760 | { | |
1761 | struct of_phandle_args clkspec; | |
1762 | const char *clk_name; | |
1763 | int rc; | |
1764 | ||
1765 | if (index < 0) | |
1766 | return NULL; | |
1767 | ||
1768 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
1769 | &clkspec); | |
1770 | if (rc) | |
1771 | return NULL; | |
1772 | ||
1773 | if (of_property_read_string_index(clkspec.np, "clock-output-names", | |
1774 | clkspec.args_count ? clkspec.args[0] : 0, | |
1775 | &clk_name) < 0) | |
1776 | clk_name = clkspec.np->name; | |
1777 | ||
1778 | of_node_put(clkspec.np); | |
1779 | return clk_name; | |
1780 | } | |
1781 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
1782 | ||
1783 | /** | |
1784 | * of_clk_init() - Scan and init clock providers from the DT | |
1785 | * @matches: array of compatible values and init functions for providers. | |
1786 | * | |
1787 | * This function scans the device tree for matching clock providers and | |
1788 | * calls their initialization functions | |
1789 | */ | |
1790 | void __init of_clk_init(const struct of_device_id *matches) | |
1791 | { | |
1792 | struct device_node *np; | |
1793 | ||
1794 | for_each_matching_node(np, matches) { | |
1795 | const struct of_device_id *match = of_match_node(matches, np); | |
1796 | of_clk_init_cb_t clk_init_cb = match->data; | |
1797 | clk_init_cb(np); | |
1798 | } | |
1799 | } | |
1800 | #endif |