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b2476490 MT |
1 | /* |
2 | * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com> | |
3 | * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * Standard functionality for the common clock API. See Documentation/clk.txt | |
10 | */ | |
11 | ||
12 | #include <linux/clk-private.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/mutex.h> | |
15 | #include <linux/spinlock.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/list.h> | |
18 | #include <linux/slab.h> | |
766e6a4e | 19 | #include <linux/of.h> |
46c8773a | 20 | #include <linux/device.h> |
f2f6c255 | 21 | #include <linux/init.h> |
b2476490 MT |
22 | |
23 | static DEFINE_SPINLOCK(enable_lock); | |
24 | static DEFINE_MUTEX(prepare_lock); | |
25 | ||
26 | static HLIST_HEAD(clk_root_list); | |
27 | static HLIST_HEAD(clk_orphan_list); | |
28 | static LIST_HEAD(clk_notifier_list); | |
29 | ||
30 | /*** debugfs support ***/ | |
31 | ||
32 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
33 | #include <linux/debugfs.h> | |
34 | ||
35 | static struct dentry *rootdir; | |
36 | static struct dentry *orphandir; | |
37 | static int inited = 0; | |
38 | ||
1af599df PG |
39 | static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level) |
40 | { | |
41 | if (!c) | |
42 | return; | |
43 | ||
44 | seq_printf(s, "%*s%-*s %-11d %-12d %-10lu", | |
45 | level * 3 + 1, "", | |
46 | 30 - level * 3, c->name, | |
47 | c->enable_count, c->prepare_count, c->rate); | |
48 | seq_printf(s, "\n"); | |
49 | } | |
50 | ||
51 | static void clk_summary_show_subtree(struct seq_file *s, struct clk *c, | |
52 | int level) | |
53 | { | |
54 | struct clk *child; | |
55 | struct hlist_node *tmp; | |
56 | ||
57 | if (!c) | |
58 | return; | |
59 | ||
60 | clk_summary_show_one(s, c, level); | |
61 | ||
62 | hlist_for_each_entry(child, tmp, &c->children, child_node) | |
63 | clk_summary_show_subtree(s, child, level + 1); | |
64 | } | |
65 | ||
66 | static int clk_summary_show(struct seq_file *s, void *data) | |
67 | { | |
68 | struct clk *c; | |
69 | struct hlist_node *tmp; | |
70 | ||
71 | seq_printf(s, " clock enable_cnt prepare_cnt rate\n"); | |
72 | seq_printf(s, "---------------------------------------------------------------------\n"); | |
73 | ||
74 | mutex_lock(&prepare_lock); | |
75 | ||
76 | hlist_for_each_entry(c, tmp, &clk_root_list, child_node) | |
77 | clk_summary_show_subtree(s, c, 0); | |
78 | ||
79 | hlist_for_each_entry(c, tmp, &clk_orphan_list, child_node) | |
80 | clk_summary_show_subtree(s, c, 0); | |
81 | ||
82 | mutex_unlock(&prepare_lock); | |
83 | ||
84 | return 0; | |
85 | } | |
86 | ||
87 | ||
88 | static int clk_summary_open(struct inode *inode, struct file *file) | |
89 | { | |
90 | return single_open(file, clk_summary_show, inode->i_private); | |
91 | } | |
92 | ||
93 | static const struct file_operations clk_summary_fops = { | |
94 | .open = clk_summary_open, | |
95 | .read = seq_read, | |
96 | .llseek = seq_lseek, | |
97 | .release = single_release, | |
98 | }; | |
99 | ||
bddca894 PG |
100 | static void clk_dump_one(struct seq_file *s, struct clk *c, int level) |
101 | { | |
102 | if (!c) | |
103 | return; | |
104 | ||
105 | seq_printf(s, "\"%s\": { ", c->name); | |
106 | seq_printf(s, "\"enable_count\": %d,", c->enable_count); | |
107 | seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); | |
108 | seq_printf(s, "\"rate\": %lu", c->rate); | |
109 | } | |
110 | ||
111 | static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) | |
112 | { | |
113 | struct clk *child; | |
114 | struct hlist_node *tmp; | |
115 | ||
116 | if (!c) | |
117 | return; | |
118 | ||
119 | clk_dump_one(s, c, level); | |
120 | ||
121 | hlist_for_each_entry(child, tmp, &c->children, child_node) { | |
122 | seq_printf(s, ","); | |
123 | clk_dump_subtree(s, child, level + 1); | |
124 | } | |
125 | ||
126 | seq_printf(s, "}"); | |
127 | } | |
128 | ||
129 | static int clk_dump(struct seq_file *s, void *data) | |
130 | { | |
131 | struct clk *c; | |
132 | struct hlist_node *tmp; | |
133 | bool first_node = true; | |
134 | ||
135 | seq_printf(s, "{"); | |
136 | ||
137 | mutex_lock(&prepare_lock); | |
138 | ||
139 | hlist_for_each_entry(c, tmp, &clk_root_list, child_node) { | |
140 | if (!first_node) | |
141 | seq_printf(s, ","); | |
142 | first_node = false; | |
143 | clk_dump_subtree(s, c, 0); | |
144 | } | |
145 | ||
146 | hlist_for_each_entry(c, tmp, &clk_orphan_list, child_node) { | |
147 | seq_printf(s, ","); | |
148 | clk_dump_subtree(s, c, 0); | |
149 | } | |
150 | ||
151 | mutex_unlock(&prepare_lock); | |
152 | ||
153 | seq_printf(s, "}"); | |
154 | return 0; | |
155 | } | |
156 | ||
157 | ||
158 | static int clk_dump_open(struct inode *inode, struct file *file) | |
159 | { | |
160 | return single_open(file, clk_dump, inode->i_private); | |
161 | } | |
162 | ||
163 | static const struct file_operations clk_dump_fops = { | |
164 | .open = clk_dump_open, | |
165 | .read = seq_read, | |
166 | .llseek = seq_lseek, | |
167 | .release = single_release, | |
168 | }; | |
169 | ||
b2476490 MT |
170 | /* caller must hold prepare_lock */ |
171 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) | |
172 | { | |
173 | struct dentry *d; | |
174 | int ret = -ENOMEM; | |
175 | ||
176 | if (!clk || !pdentry) { | |
177 | ret = -EINVAL; | |
178 | goto out; | |
179 | } | |
180 | ||
181 | d = debugfs_create_dir(clk->name, pdentry); | |
182 | if (!d) | |
183 | goto out; | |
184 | ||
185 | clk->dentry = d; | |
186 | ||
187 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, | |
188 | (u32 *)&clk->rate); | |
189 | if (!d) | |
190 | goto err_out; | |
191 | ||
192 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, | |
193 | (u32 *)&clk->flags); | |
194 | if (!d) | |
195 | goto err_out; | |
196 | ||
197 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, | |
198 | (u32 *)&clk->prepare_count); | |
199 | if (!d) | |
200 | goto err_out; | |
201 | ||
202 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, | |
203 | (u32 *)&clk->enable_count); | |
204 | if (!d) | |
205 | goto err_out; | |
206 | ||
207 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, | |
208 | (u32 *)&clk->notifier_count); | |
209 | if (!d) | |
210 | goto err_out; | |
211 | ||
212 | ret = 0; | |
213 | goto out; | |
214 | ||
215 | err_out: | |
216 | debugfs_remove(clk->dentry); | |
217 | out: | |
218 | return ret; | |
219 | } | |
220 | ||
221 | /* caller must hold prepare_lock */ | |
222 | static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry) | |
223 | { | |
224 | struct clk *child; | |
225 | struct hlist_node *tmp; | |
226 | int ret = -EINVAL;; | |
227 | ||
228 | if (!clk || !pdentry) | |
229 | goto out; | |
230 | ||
231 | ret = clk_debug_create_one(clk, pdentry); | |
232 | ||
233 | if (ret) | |
234 | goto out; | |
235 | ||
236 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
237 | clk_debug_create_subtree(child, clk->dentry); | |
238 | ||
239 | ret = 0; | |
240 | out: | |
241 | return ret; | |
242 | } | |
243 | ||
244 | /** | |
245 | * clk_debug_register - add a clk node to the debugfs clk tree | |
246 | * @clk: the clk being added to the debugfs clk tree | |
247 | * | |
248 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been | |
249 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
250 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
251 | * | |
252 | * Caller must hold prepare_lock. Only clk_init calls this function (so | |
253 | * far) so this is taken care. | |
254 | */ | |
255 | static int clk_debug_register(struct clk *clk) | |
256 | { | |
257 | struct clk *parent; | |
258 | struct dentry *pdentry; | |
259 | int ret = 0; | |
260 | ||
261 | if (!inited) | |
262 | goto out; | |
263 | ||
264 | parent = clk->parent; | |
265 | ||
266 | /* | |
267 | * Check to see if a clk is a root clk. Also check that it is | |
268 | * safe to add this clk to debugfs | |
269 | */ | |
270 | if (!parent) | |
271 | if (clk->flags & CLK_IS_ROOT) | |
272 | pdentry = rootdir; | |
273 | else | |
274 | pdentry = orphandir; | |
275 | else | |
276 | if (parent->dentry) | |
277 | pdentry = parent->dentry; | |
278 | else | |
279 | goto out; | |
280 | ||
281 | ret = clk_debug_create_subtree(clk, pdentry); | |
282 | ||
283 | out: | |
284 | return ret; | |
285 | } | |
286 | ||
287 | /** | |
288 | * clk_debug_init - lazily create the debugfs clk tree visualization | |
289 | * | |
290 | * clks are often initialized very early during boot before memory can | |
291 | * be dynamically allocated and well before debugfs is setup. | |
292 | * clk_debug_init walks the clk tree hierarchy while holding | |
293 | * prepare_lock and creates the topology as part of a late_initcall, | |
294 | * thus insuring that clks initialized very early will still be | |
295 | * represented in the debugfs clk tree. This function should only be | |
296 | * called once at boot-time, and all other clks added dynamically will | |
297 | * be done so with clk_debug_register. | |
298 | */ | |
299 | static int __init clk_debug_init(void) | |
300 | { | |
301 | struct clk *clk; | |
302 | struct hlist_node *tmp; | |
1af599df | 303 | struct dentry *d; |
b2476490 MT |
304 | |
305 | rootdir = debugfs_create_dir("clk", NULL); | |
306 | ||
307 | if (!rootdir) | |
308 | return -ENOMEM; | |
309 | ||
1af599df PG |
310 | d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, NULL, |
311 | &clk_summary_fops); | |
312 | if (!d) | |
313 | return -ENOMEM; | |
314 | ||
bddca894 PG |
315 | d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, NULL, |
316 | &clk_dump_fops); | |
317 | if (!d) | |
318 | return -ENOMEM; | |
319 | ||
b2476490 MT |
320 | orphandir = debugfs_create_dir("orphans", rootdir); |
321 | ||
322 | if (!orphandir) | |
323 | return -ENOMEM; | |
324 | ||
325 | mutex_lock(&prepare_lock); | |
326 | ||
327 | hlist_for_each_entry(clk, tmp, &clk_root_list, child_node) | |
328 | clk_debug_create_subtree(clk, rootdir); | |
329 | ||
330 | hlist_for_each_entry(clk, tmp, &clk_orphan_list, child_node) | |
331 | clk_debug_create_subtree(clk, orphandir); | |
332 | ||
333 | inited = 1; | |
334 | ||
335 | mutex_unlock(&prepare_lock); | |
336 | ||
337 | return 0; | |
338 | } | |
339 | late_initcall(clk_debug_init); | |
340 | #else | |
341 | static inline int clk_debug_register(struct clk *clk) { return 0; } | |
70d347e6 | 342 | #endif |
b2476490 | 343 | |
b2476490 MT |
344 | /* caller must hold prepare_lock */ |
345 | static void clk_disable_unused_subtree(struct clk *clk) | |
346 | { | |
347 | struct clk *child; | |
348 | struct hlist_node *tmp; | |
349 | unsigned long flags; | |
350 | ||
351 | if (!clk) | |
352 | goto out; | |
353 | ||
354 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
355 | clk_disable_unused_subtree(child); | |
356 | ||
357 | spin_lock_irqsave(&enable_lock, flags); | |
358 | ||
359 | if (clk->enable_count) | |
360 | goto unlock_out; | |
361 | ||
362 | if (clk->flags & CLK_IGNORE_UNUSED) | |
363 | goto unlock_out; | |
364 | ||
7c045a55 MT |
365 | /* |
366 | * some gate clocks have special needs during the disable-unused | |
367 | * sequence. call .disable_unused if available, otherwise fall | |
368 | * back to .disable | |
369 | */ | |
370 | if (__clk_is_enabled(clk)) { | |
371 | if (clk->ops->disable_unused) | |
372 | clk->ops->disable_unused(clk->hw); | |
373 | else if (clk->ops->disable) | |
374 | clk->ops->disable(clk->hw); | |
375 | } | |
b2476490 MT |
376 | |
377 | unlock_out: | |
378 | spin_unlock_irqrestore(&enable_lock, flags); | |
379 | ||
380 | out: | |
381 | return; | |
382 | } | |
383 | ||
384 | static int clk_disable_unused(void) | |
385 | { | |
386 | struct clk *clk; | |
387 | struct hlist_node *tmp; | |
388 | ||
389 | mutex_lock(&prepare_lock); | |
390 | ||
391 | hlist_for_each_entry(clk, tmp, &clk_root_list, child_node) | |
392 | clk_disable_unused_subtree(clk); | |
393 | ||
394 | hlist_for_each_entry(clk, tmp, &clk_orphan_list, child_node) | |
395 | clk_disable_unused_subtree(clk); | |
396 | ||
397 | mutex_unlock(&prepare_lock); | |
398 | ||
399 | return 0; | |
400 | } | |
401 | late_initcall(clk_disable_unused); | |
b2476490 MT |
402 | |
403 | /*** helper functions ***/ | |
404 | ||
65800b2c | 405 | const char *__clk_get_name(struct clk *clk) |
b2476490 MT |
406 | { |
407 | return !clk ? NULL : clk->name; | |
408 | } | |
4895084c | 409 | EXPORT_SYMBOL_GPL(__clk_get_name); |
b2476490 | 410 | |
65800b2c | 411 | struct clk_hw *__clk_get_hw(struct clk *clk) |
b2476490 MT |
412 | { |
413 | return !clk ? NULL : clk->hw; | |
414 | } | |
415 | ||
65800b2c | 416 | u8 __clk_get_num_parents(struct clk *clk) |
b2476490 | 417 | { |
2ac6b1f5 | 418 | return !clk ? 0 : clk->num_parents; |
b2476490 MT |
419 | } |
420 | ||
65800b2c | 421 | struct clk *__clk_get_parent(struct clk *clk) |
b2476490 MT |
422 | { |
423 | return !clk ? NULL : clk->parent; | |
424 | } | |
425 | ||
65800b2c | 426 | unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 427 | { |
2ac6b1f5 | 428 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
429 | } |
430 | ||
65800b2c | 431 | unsigned int __clk_get_prepare_count(struct clk *clk) |
b2476490 | 432 | { |
2ac6b1f5 | 433 | return !clk ? 0 : clk->prepare_count; |
b2476490 MT |
434 | } |
435 | ||
436 | unsigned long __clk_get_rate(struct clk *clk) | |
437 | { | |
438 | unsigned long ret; | |
439 | ||
440 | if (!clk) { | |
34e44fe8 | 441 | ret = 0; |
b2476490 MT |
442 | goto out; |
443 | } | |
444 | ||
445 | ret = clk->rate; | |
446 | ||
447 | if (clk->flags & CLK_IS_ROOT) | |
448 | goto out; | |
449 | ||
450 | if (!clk->parent) | |
34e44fe8 | 451 | ret = 0; |
b2476490 MT |
452 | |
453 | out: | |
454 | return ret; | |
455 | } | |
456 | ||
65800b2c | 457 | unsigned long __clk_get_flags(struct clk *clk) |
b2476490 | 458 | { |
2ac6b1f5 | 459 | return !clk ? 0 : clk->flags; |
b2476490 MT |
460 | } |
461 | ||
2ac6b1f5 | 462 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
463 | { |
464 | int ret; | |
465 | ||
466 | if (!clk) | |
2ac6b1f5 | 467 | return false; |
b2476490 MT |
468 | |
469 | /* | |
470 | * .is_enabled is only mandatory for clocks that gate | |
471 | * fall back to software usage counter if .is_enabled is missing | |
472 | */ | |
473 | if (!clk->ops->is_enabled) { | |
474 | ret = clk->enable_count ? 1 : 0; | |
475 | goto out; | |
476 | } | |
477 | ||
478 | ret = clk->ops->is_enabled(clk->hw); | |
479 | out: | |
2ac6b1f5 | 480 | return !!ret; |
b2476490 MT |
481 | } |
482 | ||
483 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
484 | { | |
485 | struct clk *child; | |
486 | struct clk *ret; | |
487 | struct hlist_node *tmp; | |
488 | ||
489 | if (!strcmp(clk->name, name)) | |
490 | return clk; | |
491 | ||
492 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
493 | ret = __clk_lookup_subtree(name, child); | |
494 | if (ret) | |
495 | return ret; | |
496 | } | |
497 | ||
498 | return NULL; | |
499 | } | |
500 | ||
501 | struct clk *__clk_lookup(const char *name) | |
502 | { | |
503 | struct clk *root_clk; | |
504 | struct clk *ret; | |
505 | struct hlist_node *tmp; | |
506 | ||
507 | if (!name) | |
508 | return NULL; | |
509 | ||
510 | /* search the 'proper' clk tree first */ | |
511 | hlist_for_each_entry(root_clk, tmp, &clk_root_list, child_node) { | |
512 | ret = __clk_lookup_subtree(name, root_clk); | |
513 | if (ret) | |
514 | return ret; | |
515 | } | |
516 | ||
517 | /* if not found, then search the orphan tree */ | |
518 | hlist_for_each_entry(root_clk, tmp, &clk_orphan_list, child_node) { | |
519 | ret = __clk_lookup_subtree(name, root_clk); | |
520 | if (ret) | |
521 | return ret; | |
522 | } | |
523 | ||
524 | return NULL; | |
525 | } | |
526 | ||
527 | /*** clk api ***/ | |
528 | ||
529 | void __clk_unprepare(struct clk *clk) | |
530 | { | |
531 | if (!clk) | |
532 | return; | |
533 | ||
534 | if (WARN_ON(clk->prepare_count == 0)) | |
535 | return; | |
536 | ||
537 | if (--clk->prepare_count > 0) | |
538 | return; | |
539 | ||
540 | WARN_ON(clk->enable_count > 0); | |
541 | ||
542 | if (clk->ops->unprepare) | |
543 | clk->ops->unprepare(clk->hw); | |
544 | ||
545 | __clk_unprepare(clk->parent); | |
546 | } | |
547 | ||
548 | /** | |
549 | * clk_unprepare - undo preparation of a clock source | |
550 | * @clk: the clk being unprepare | |
551 | * | |
552 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
553 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
554 | * if the operation may sleep. One example is a clk which is accessed over | |
555 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
556 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
557 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
558 | */ | |
559 | void clk_unprepare(struct clk *clk) | |
560 | { | |
561 | mutex_lock(&prepare_lock); | |
562 | __clk_unprepare(clk); | |
563 | mutex_unlock(&prepare_lock); | |
564 | } | |
565 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
566 | ||
567 | int __clk_prepare(struct clk *clk) | |
568 | { | |
569 | int ret = 0; | |
570 | ||
571 | if (!clk) | |
572 | return 0; | |
573 | ||
574 | if (clk->prepare_count == 0) { | |
575 | ret = __clk_prepare(clk->parent); | |
576 | if (ret) | |
577 | return ret; | |
578 | ||
579 | if (clk->ops->prepare) { | |
580 | ret = clk->ops->prepare(clk->hw); | |
581 | if (ret) { | |
582 | __clk_unprepare(clk->parent); | |
583 | return ret; | |
584 | } | |
585 | } | |
586 | } | |
587 | ||
588 | clk->prepare_count++; | |
589 | ||
590 | return 0; | |
591 | } | |
592 | ||
593 | /** | |
594 | * clk_prepare - prepare a clock source | |
595 | * @clk: the clk being prepared | |
596 | * | |
597 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
598 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
599 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
600 | * the complex case a clk ungate operation may require a fast and a slow part. | |
601 | * It is this reason that clk_prepare and clk_enable are not mutually | |
602 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
603 | * Returns 0 on success, -EERROR otherwise. | |
604 | */ | |
605 | int clk_prepare(struct clk *clk) | |
606 | { | |
607 | int ret; | |
608 | ||
609 | mutex_lock(&prepare_lock); | |
610 | ret = __clk_prepare(clk); | |
611 | mutex_unlock(&prepare_lock); | |
612 | ||
613 | return ret; | |
614 | } | |
615 | EXPORT_SYMBOL_GPL(clk_prepare); | |
616 | ||
617 | static void __clk_disable(struct clk *clk) | |
618 | { | |
619 | if (!clk) | |
620 | return; | |
621 | ||
e47c6a34 FW |
622 | if (WARN_ON(IS_ERR(clk))) |
623 | return; | |
624 | ||
b2476490 MT |
625 | if (WARN_ON(clk->enable_count == 0)) |
626 | return; | |
627 | ||
628 | if (--clk->enable_count > 0) | |
629 | return; | |
630 | ||
631 | if (clk->ops->disable) | |
632 | clk->ops->disable(clk->hw); | |
633 | ||
634 | __clk_disable(clk->parent); | |
635 | } | |
636 | ||
637 | /** | |
638 | * clk_disable - gate a clock | |
639 | * @clk: the clk being gated | |
640 | * | |
641 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
642 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
643 | * clk if the operation is fast and will never sleep. One example is a | |
644 | * SoC-internal clk which is controlled via simple register writes. In the | |
645 | * complex case a clk gate operation may require a fast and a slow part. It is | |
646 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
647 | * In fact clk_disable must be called before clk_unprepare. | |
648 | */ | |
649 | void clk_disable(struct clk *clk) | |
650 | { | |
651 | unsigned long flags; | |
652 | ||
653 | spin_lock_irqsave(&enable_lock, flags); | |
654 | __clk_disable(clk); | |
655 | spin_unlock_irqrestore(&enable_lock, flags); | |
656 | } | |
657 | EXPORT_SYMBOL_GPL(clk_disable); | |
658 | ||
659 | static int __clk_enable(struct clk *clk) | |
660 | { | |
661 | int ret = 0; | |
662 | ||
663 | if (!clk) | |
664 | return 0; | |
665 | ||
666 | if (WARN_ON(clk->prepare_count == 0)) | |
667 | return -ESHUTDOWN; | |
668 | ||
669 | if (clk->enable_count == 0) { | |
670 | ret = __clk_enable(clk->parent); | |
671 | ||
672 | if (ret) | |
673 | return ret; | |
674 | ||
675 | if (clk->ops->enable) { | |
676 | ret = clk->ops->enable(clk->hw); | |
677 | if (ret) { | |
678 | __clk_disable(clk->parent); | |
679 | return ret; | |
680 | } | |
681 | } | |
682 | } | |
683 | ||
684 | clk->enable_count++; | |
685 | return 0; | |
686 | } | |
687 | ||
688 | /** | |
689 | * clk_enable - ungate a clock | |
690 | * @clk: the clk being ungated | |
691 | * | |
692 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
693 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
694 | * if the operation will never sleep. One example is a SoC-internal clk which | |
695 | * is controlled via simple register writes. In the complex case a clk ungate | |
696 | * operation may require a fast and a slow part. It is this reason that | |
697 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
698 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
699 | * otherwise. | |
700 | */ | |
701 | int clk_enable(struct clk *clk) | |
702 | { | |
703 | unsigned long flags; | |
704 | int ret; | |
705 | ||
706 | spin_lock_irqsave(&enable_lock, flags); | |
707 | ret = __clk_enable(clk); | |
708 | spin_unlock_irqrestore(&enable_lock, flags); | |
709 | ||
710 | return ret; | |
711 | } | |
712 | EXPORT_SYMBOL_GPL(clk_enable); | |
713 | ||
b2476490 MT |
714 | /** |
715 | * __clk_round_rate - round the given rate for a clk | |
716 | * @clk: round the rate of this clock | |
717 | * | |
718 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
719 | */ | |
720 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
721 | { | |
81536e07 | 722 | unsigned long parent_rate = 0; |
b2476490 MT |
723 | |
724 | if (!clk) | |
2ac6b1f5 | 725 | return 0; |
b2476490 | 726 | |
f4d8af2e SG |
727 | if (!clk->ops->round_rate) { |
728 | if (clk->flags & CLK_SET_RATE_PARENT) | |
729 | return __clk_round_rate(clk->parent, rate); | |
730 | else | |
731 | return clk->rate; | |
732 | } | |
b2476490 | 733 | |
81536e07 SG |
734 | if (clk->parent) |
735 | parent_rate = clk->parent->rate; | |
736 | ||
737 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); | |
b2476490 MT |
738 | } |
739 | ||
740 | /** | |
741 | * clk_round_rate - round the given rate for a clk | |
742 | * @clk: the clk for which we are rounding a rate | |
743 | * @rate: the rate which is to be rounded | |
744 | * | |
745 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
746 | * use which is then returned. If clk doesn't support round_rate operation | |
747 | * then the parent rate is returned. | |
748 | */ | |
749 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
750 | { | |
751 | unsigned long ret; | |
752 | ||
753 | mutex_lock(&prepare_lock); | |
754 | ret = __clk_round_rate(clk, rate); | |
755 | mutex_unlock(&prepare_lock); | |
756 | ||
757 | return ret; | |
758 | } | |
759 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
760 | ||
761 | /** | |
762 | * __clk_notify - call clk notifier chain | |
763 | * @clk: struct clk * that is changing rate | |
764 | * @msg: clk notifier type (see include/linux/clk.h) | |
765 | * @old_rate: old clk rate | |
766 | * @new_rate: new clk rate | |
767 | * | |
768 | * Triggers a notifier call chain on the clk rate-change notification | |
769 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
770 | * and current rates to the notifier callback. Intended to be called by | |
771 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
772 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
773 | * a driver returns that. | |
774 | */ | |
775 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
776 | unsigned long old_rate, unsigned long new_rate) | |
777 | { | |
778 | struct clk_notifier *cn; | |
779 | struct clk_notifier_data cnd; | |
780 | int ret = NOTIFY_DONE; | |
781 | ||
782 | cnd.clk = clk; | |
783 | cnd.old_rate = old_rate; | |
784 | cnd.new_rate = new_rate; | |
785 | ||
786 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
787 | if (cn->clk == clk) { | |
788 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
789 | &cnd); | |
790 | break; | |
791 | } | |
792 | } | |
793 | ||
794 | return ret; | |
795 | } | |
796 | ||
797 | /** | |
798 | * __clk_recalc_rates | |
799 | * @clk: first clk in the subtree | |
800 | * @msg: notification type (see include/linux/clk.h) | |
801 | * | |
802 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
803 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
804 | * it is assumed that the clock will take on the rate of it's parent. | |
805 | * | |
806 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
807 | * if necessary. | |
808 | * | |
809 | * Caller must hold prepare_lock. | |
810 | */ | |
811 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
812 | { | |
813 | unsigned long old_rate; | |
814 | unsigned long parent_rate = 0; | |
815 | struct hlist_node *tmp; | |
816 | struct clk *child; | |
817 | ||
818 | old_rate = clk->rate; | |
819 | ||
820 | if (clk->parent) | |
821 | parent_rate = clk->parent->rate; | |
822 | ||
823 | if (clk->ops->recalc_rate) | |
824 | clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
825 | else | |
826 | clk->rate = parent_rate; | |
827 | ||
828 | /* | |
829 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
830 | * & ABORT_RATE_CHANGE notifiers | |
831 | */ | |
832 | if (clk->notifier_count && msg) | |
833 | __clk_notify(clk, msg, old_rate, clk->rate); | |
834 | ||
835 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
836 | __clk_recalc_rates(child, msg); | |
837 | } | |
838 | ||
a093bde2 UH |
839 | /** |
840 | * clk_get_rate - return the rate of clk | |
841 | * @clk: the clk whose rate is being returned | |
842 | * | |
843 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
844 | * is set, which means a recalc_rate will be issued. | |
845 | * If clk is NULL then returns 0. | |
846 | */ | |
847 | unsigned long clk_get_rate(struct clk *clk) | |
848 | { | |
849 | unsigned long rate; | |
850 | ||
851 | mutex_lock(&prepare_lock); | |
852 | ||
853 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
854 | __clk_recalc_rates(clk, 0); | |
855 | ||
856 | rate = __clk_get_rate(clk); | |
857 | mutex_unlock(&prepare_lock); | |
858 | ||
859 | return rate; | |
860 | } | |
861 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
862 | ||
b2476490 MT |
863 | /** |
864 | * __clk_speculate_rates | |
865 | * @clk: first clk in the subtree | |
866 | * @parent_rate: the "future" rate of clk's parent | |
867 | * | |
868 | * Walks the subtree of clks starting with clk, speculating rates as it | |
869 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
870 | * | |
871 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
872 | * pre-rate change notifications and returns early if no clks in the | |
873 | * subtree have subscribed to the notifications. Note that if a clk does not | |
874 | * implement the .recalc_rate callback then it is assumed that the clock will | |
875 | * take on the rate of it's parent. | |
876 | * | |
877 | * Caller must hold prepare_lock. | |
878 | */ | |
879 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
880 | { | |
881 | struct hlist_node *tmp; | |
882 | struct clk *child; | |
883 | unsigned long new_rate; | |
884 | int ret = NOTIFY_DONE; | |
885 | ||
886 | if (clk->ops->recalc_rate) | |
887 | new_rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
888 | else | |
889 | new_rate = parent_rate; | |
890 | ||
891 | /* abort the rate change if a driver returns NOTIFY_BAD */ | |
892 | if (clk->notifier_count) | |
893 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
894 | ||
895 | if (ret == NOTIFY_BAD) | |
896 | goto out; | |
897 | ||
898 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
899 | ret = __clk_speculate_rates(child, new_rate); | |
900 | if (ret == NOTIFY_BAD) | |
901 | break; | |
902 | } | |
903 | ||
904 | out: | |
905 | return ret; | |
906 | } | |
907 | ||
908 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate) | |
909 | { | |
910 | struct clk *child; | |
911 | struct hlist_node *tmp; | |
912 | ||
913 | clk->new_rate = new_rate; | |
914 | ||
915 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
916 | if (child->ops->recalc_rate) | |
917 | child->new_rate = child->ops->recalc_rate(child->hw, new_rate); | |
918 | else | |
919 | child->new_rate = new_rate; | |
920 | clk_calc_subtree(child, child->new_rate); | |
921 | } | |
922 | } | |
923 | ||
924 | /* | |
925 | * calculate the new rates returning the topmost clock that has to be | |
926 | * changed. | |
927 | */ | |
928 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
929 | { | |
930 | struct clk *top = clk; | |
81536e07 | 931 | unsigned long best_parent_rate = 0; |
b2476490 MT |
932 | unsigned long new_rate; |
933 | ||
7452b219 MT |
934 | /* sanity */ |
935 | if (IS_ERR_OR_NULL(clk)) | |
936 | return NULL; | |
937 | ||
63f5c3b2 MT |
938 | /* save parent rate, if it exists */ |
939 | if (clk->parent) | |
940 | best_parent_rate = clk->parent->rate; | |
941 | ||
7452b219 MT |
942 | /* never propagate up to the parent */ |
943 | if (!(clk->flags & CLK_SET_RATE_PARENT)) { | |
944 | if (!clk->ops->round_rate) { | |
945 | clk->new_rate = clk->rate; | |
946 | return NULL; | |
7452b219 | 947 | } |
63f5c3b2 MT |
948 | new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); |
949 | goto out; | |
7452b219 MT |
950 | } |
951 | ||
952 | /* need clk->parent from here on out */ | |
953 | if (!clk->parent) { | |
954 | pr_debug("%s: %s has NULL parent\n", __func__, clk->name); | |
b2476490 MT |
955 | return NULL; |
956 | } | |
957 | ||
7452b219 | 958 | if (!clk->ops->round_rate) { |
b2476490 | 959 | top = clk_calc_new_rates(clk->parent, rate); |
1b2f9903 | 960 | new_rate = clk->parent->new_rate; |
b2476490 MT |
961 | |
962 | goto out; | |
963 | } | |
964 | ||
7452b219 | 965 | new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); |
b2476490 MT |
966 | |
967 | if (best_parent_rate != clk->parent->rate) { | |
968 | top = clk_calc_new_rates(clk->parent, best_parent_rate); | |
969 | ||
970 | goto out; | |
971 | } | |
972 | ||
973 | out: | |
974 | clk_calc_subtree(clk, new_rate); | |
975 | ||
976 | return top; | |
977 | } | |
978 | ||
979 | /* | |
980 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
981 | * so that in case of an error we can walk down the whole tree again and | |
982 | * abort the change. | |
983 | */ | |
984 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
985 | { | |
986 | struct hlist_node *tmp; | |
987 | struct clk *child, *fail_clk = NULL; | |
988 | int ret = NOTIFY_DONE; | |
989 | ||
990 | if (clk->rate == clk->new_rate) | |
991 | return 0; | |
992 | ||
993 | if (clk->notifier_count) { | |
994 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
995 | if (ret == NOTIFY_BAD) | |
996 | fail_clk = clk; | |
997 | } | |
998 | ||
999 | hlist_for_each_entry(child, tmp, &clk->children, child_node) { | |
1000 | clk = clk_propagate_rate_change(child, event); | |
1001 | if (clk) | |
1002 | fail_clk = clk; | |
1003 | } | |
1004 | ||
1005 | return fail_clk; | |
1006 | } | |
1007 | ||
1008 | /* | |
1009 | * walk down a subtree and set the new rates notifying the rate | |
1010 | * change on the way | |
1011 | */ | |
1012 | static void clk_change_rate(struct clk *clk) | |
1013 | { | |
1014 | struct clk *child; | |
1015 | unsigned long old_rate; | |
bf47b4fd | 1016 | unsigned long best_parent_rate = 0; |
b2476490 MT |
1017 | struct hlist_node *tmp; |
1018 | ||
1019 | old_rate = clk->rate; | |
1020 | ||
bf47b4fd PM |
1021 | if (clk->parent) |
1022 | best_parent_rate = clk->parent->rate; | |
1023 | ||
b2476490 | 1024 | if (clk->ops->set_rate) |
bf47b4fd | 1025 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 MT |
1026 | |
1027 | if (clk->ops->recalc_rate) | |
bf47b4fd | 1028 | clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate); |
b2476490 | 1029 | else |
bf47b4fd | 1030 | clk->rate = best_parent_rate; |
b2476490 MT |
1031 | |
1032 | if (clk->notifier_count && old_rate != clk->rate) | |
1033 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
1034 | ||
1035 | hlist_for_each_entry(child, tmp, &clk->children, child_node) | |
1036 | clk_change_rate(child); | |
1037 | } | |
1038 | ||
1039 | /** | |
1040 | * clk_set_rate - specify a new rate for clk | |
1041 | * @clk: the clk whose rate is being changed | |
1042 | * @rate: the new rate for clk | |
1043 | * | |
5654dc94 | 1044 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 1045 | * |
5654dc94 MT |
1046 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
1047 | * propagate up to clk's parent; whether or not this happens depends on the | |
1048 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
1049 | * after calling .round_rate then upstream parent propagation is ignored. If | |
1050 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
1051 | * up to clk's parent and set it's rate. Upward propagation will continue | |
1052 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or | |
1053 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 1054 | * |
5654dc94 MT |
1055 | * Rate changes are accomplished via tree traversal that also recalculates the |
1056 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
1057 | * |
1058 | * Returns 0 on success, -EERROR otherwise. | |
1059 | */ | |
1060 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
1061 | { | |
1062 | struct clk *top, *fail_clk; | |
1063 | int ret = 0; | |
1064 | ||
1065 | /* prevent racing with updates to the clock topology */ | |
1066 | mutex_lock(&prepare_lock); | |
1067 | ||
1068 | /* bail early if nothing to do */ | |
1069 | if (rate == clk->rate) | |
1070 | goto out; | |
1071 | ||
7e0fa1b5 | 1072 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
1073 | ret = -EBUSY; |
1074 | goto out; | |
1075 | } | |
1076 | ||
b2476490 MT |
1077 | /* calculate new rates and get the topmost changed clock */ |
1078 | top = clk_calc_new_rates(clk, rate); | |
1079 | if (!top) { | |
1080 | ret = -EINVAL; | |
1081 | goto out; | |
1082 | } | |
1083 | ||
1084 | /* notify that we are about to change rates */ | |
1085 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
1086 | if (fail_clk) { | |
1087 | pr_warn("%s: failed to set %s rate\n", __func__, | |
1088 | fail_clk->name); | |
1089 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
1090 | ret = -EBUSY; | |
1091 | goto out; | |
1092 | } | |
1093 | ||
1094 | /* change the rates */ | |
1095 | clk_change_rate(top); | |
1096 | ||
b2476490 MT |
1097 | out: |
1098 | mutex_unlock(&prepare_lock); | |
1099 | ||
1100 | return ret; | |
1101 | } | |
1102 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
1103 | ||
1104 | /** | |
1105 | * clk_get_parent - return the parent of a clk | |
1106 | * @clk: the clk whose parent gets returned | |
1107 | * | |
1108 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
1109 | */ | |
1110 | struct clk *clk_get_parent(struct clk *clk) | |
1111 | { | |
1112 | struct clk *parent; | |
1113 | ||
1114 | mutex_lock(&prepare_lock); | |
1115 | parent = __clk_get_parent(clk); | |
1116 | mutex_unlock(&prepare_lock); | |
1117 | ||
1118 | return parent; | |
1119 | } | |
1120 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
1121 | ||
1122 | /* | |
1123 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
1124 | * optional for single-parent clocks. Always call .get_parent if it is | |
1125 | * available and WARN if it is missing for multi-parent clocks. | |
1126 | * | |
1127 | * For single-parent clocks without .get_parent, first check to see if the | |
1128 | * .parents array exists, and if so use it to avoid an expensive tree | |
1129 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
1130 | */ | |
1131 | static struct clk *__clk_init_parent(struct clk *clk) | |
1132 | { | |
1133 | struct clk *ret = NULL; | |
1134 | u8 index; | |
1135 | ||
1136 | /* handle the trivial cases */ | |
1137 | ||
1138 | if (!clk->num_parents) | |
1139 | goto out; | |
1140 | ||
1141 | if (clk->num_parents == 1) { | |
1142 | if (IS_ERR_OR_NULL(clk->parent)) | |
1143 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); | |
1144 | ret = clk->parent; | |
1145 | goto out; | |
1146 | } | |
1147 | ||
1148 | if (!clk->ops->get_parent) { | |
1149 | WARN(!clk->ops->get_parent, | |
1150 | "%s: multi-parent clocks must implement .get_parent\n", | |
1151 | __func__); | |
1152 | goto out; | |
1153 | }; | |
1154 | ||
1155 | /* | |
1156 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1157 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1158 | * clk->parent here; that is done by the calling function | |
1159 | */ | |
1160 | ||
1161 | index = clk->ops->get_parent(clk->hw); | |
1162 | ||
1163 | if (!clk->parents) | |
1164 | clk->parents = | |
7975059d | 1165 | kzalloc((sizeof(struct clk*) * clk->num_parents), |
b2476490 MT |
1166 | GFP_KERNEL); |
1167 | ||
1168 | if (!clk->parents) | |
1169 | ret = __clk_lookup(clk->parent_names[index]); | |
1170 | else if (!clk->parents[index]) | |
1171 | ret = clk->parents[index] = | |
1172 | __clk_lookup(clk->parent_names[index]); | |
1173 | else | |
1174 | ret = clk->parents[index]; | |
1175 | ||
1176 | out: | |
1177 | return ret; | |
1178 | } | |
1179 | ||
1180 | void __clk_reparent(struct clk *clk, struct clk *new_parent) | |
1181 | { | |
1182 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
1183 | struct dentry *d; | |
1184 | struct dentry *new_parent_d; | |
1185 | #endif | |
1186 | ||
1187 | if (!clk || !new_parent) | |
1188 | return; | |
1189 | ||
1190 | hlist_del(&clk->child_node); | |
1191 | ||
1192 | if (new_parent) | |
1193 | hlist_add_head(&clk->child_node, &new_parent->children); | |
1194 | else | |
1195 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1196 | ||
1197 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
1198 | if (!inited) | |
1199 | goto out; | |
1200 | ||
1201 | if (new_parent) | |
1202 | new_parent_d = new_parent->dentry; | |
1203 | else | |
1204 | new_parent_d = orphandir; | |
1205 | ||
1206 | d = debugfs_rename(clk->dentry->d_parent, clk->dentry, | |
1207 | new_parent_d, clk->name); | |
1208 | if (d) | |
1209 | clk->dentry = d; | |
1210 | else | |
1211 | pr_debug("%s: failed to rename debugfs entry for %s\n", | |
1212 | __func__, clk->name); | |
1213 | out: | |
1214 | #endif | |
1215 | ||
1216 | clk->parent = new_parent; | |
1217 | ||
1218 | __clk_recalc_rates(clk, POST_RATE_CHANGE); | |
1219 | } | |
1220 | ||
1221 | static int __clk_set_parent(struct clk *clk, struct clk *parent) | |
1222 | { | |
1223 | struct clk *old_parent; | |
1224 | unsigned long flags; | |
1225 | int ret = -EINVAL; | |
1226 | u8 i; | |
1227 | ||
1228 | old_parent = clk->parent; | |
1229 | ||
863b1327 | 1230 | if (!clk->parents) |
7975059d RN |
1231 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), |
1232 | GFP_KERNEL); | |
b2476490 MT |
1233 | |
1234 | /* | |
863b1327 RN |
1235 | * find index of new parent clock using cached parent ptrs, |
1236 | * or if not yet cached, use string name comparison and cache | |
1237 | * them now to avoid future calls to __clk_lookup. | |
b2476490 | 1238 | */ |
863b1327 RN |
1239 | for (i = 0; i < clk->num_parents; i++) { |
1240 | if (clk->parents && clk->parents[i] == parent) | |
1241 | break; | |
1242 | else if (!strcmp(clk->parent_names[i], parent->name)) { | |
1243 | if (clk->parents) | |
1244 | clk->parents[i] = __clk_lookup(parent->name); | |
1245 | break; | |
1246 | } | |
1247 | } | |
b2476490 MT |
1248 | |
1249 | if (i == clk->num_parents) { | |
1250 | pr_debug("%s: clock %s is not a possible parent of clock %s\n", | |
1251 | __func__, parent->name, clk->name); | |
1252 | goto out; | |
1253 | } | |
1254 | ||
1255 | /* migrate prepare and enable */ | |
1256 | if (clk->prepare_count) | |
1257 | __clk_prepare(parent); | |
1258 | ||
1259 | /* FIXME replace with clk_is_enabled(clk) someday */ | |
1260 | spin_lock_irqsave(&enable_lock, flags); | |
1261 | if (clk->enable_count) | |
1262 | __clk_enable(parent); | |
1263 | spin_unlock_irqrestore(&enable_lock, flags); | |
1264 | ||
1265 | /* change clock input source */ | |
1266 | ret = clk->ops->set_parent(clk->hw, i); | |
1267 | ||
1268 | /* clean up old prepare and enable */ | |
1269 | spin_lock_irqsave(&enable_lock, flags); | |
1270 | if (clk->enable_count) | |
1271 | __clk_disable(old_parent); | |
1272 | spin_unlock_irqrestore(&enable_lock, flags); | |
1273 | ||
1274 | if (clk->prepare_count) | |
1275 | __clk_unprepare(old_parent); | |
1276 | ||
1277 | out: | |
1278 | return ret; | |
1279 | } | |
1280 | ||
1281 | /** | |
1282 | * clk_set_parent - switch the parent of a mux clk | |
1283 | * @clk: the mux clk whose input we are switching | |
1284 | * @parent: the new input to clk | |
1285 | * | |
1286 | * Re-parent clk to use parent as it's new input source. If clk has the | |
1287 | * CLK_SET_PARENT_GATE flag set then clk must be gated for this | |
1288 | * operation to succeed. After successfully changing clk's parent | |
1289 | * clk_set_parent will update the clk topology, sysfs topology and | |
1290 | * propagate rate recalculation via __clk_recalc_rates. Returns 0 on | |
1291 | * success, -EERROR otherwise. | |
1292 | */ | |
1293 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
1294 | { | |
1295 | int ret = 0; | |
1296 | ||
1297 | if (!clk || !clk->ops) | |
1298 | return -EINVAL; | |
1299 | ||
1300 | if (!clk->ops->set_parent) | |
1301 | return -ENOSYS; | |
1302 | ||
1303 | /* prevent racing with updates to the clock topology */ | |
1304 | mutex_lock(&prepare_lock); | |
1305 | ||
1306 | if (clk->parent == parent) | |
1307 | goto out; | |
1308 | ||
1309 | /* propagate PRE_RATE_CHANGE notifications */ | |
1310 | if (clk->notifier_count) | |
1311 | ret = __clk_speculate_rates(clk, parent->rate); | |
1312 | ||
1313 | /* abort if a driver objects */ | |
1314 | if (ret == NOTIFY_STOP) | |
1315 | goto out; | |
1316 | ||
1317 | /* only re-parent if the clock is not in use */ | |
1318 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) | |
1319 | ret = -EBUSY; | |
1320 | else | |
1321 | ret = __clk_set_parent(clk, parent); | |
1322 | ||
1323 | /* propagate ABORT_RATE_CHANGE if .set_parent failed */ | |
1324 | if (ret) { | |
1325 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); | |
1326 | goto out; | |
1327 | } | |
1328 | ||
1329 | /* propagate rate recalculation downstream */ | |
1330 | __clk_reparent(clk, parent); | |
1331 | ||
1332 | out: | |
1333 | mutex_unlock(&prepare_lock); | |
1334 | ||
1335 | return ret; | |
1336 | } | |
1337 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1338 | ||
1339 | /** | |
1340 | * __clk_init - initialize the data structures in a struct clk | |
1341 | * @dev: device initializing this clk, placeholder for now | |
1342 | * @clk: clk being initialized | |
1343 | * | |
1344 | * Initializes the lists in struct clk, queries the hardware for the | |
1345 | * parent and rate and sets them both. | |
b2476490 | 1346 | */ |
d1302a36 | 1347 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1348 | { |
d1302a36 | 1349 | int i, ret = 0; |
b2476490 MT |
1350 | struct clk *orphan; |
1351 | struct hlist_node *tmp, *tmp2; | |
1352 | ||
1353 | if (!clk) | |
d1302a36 | 1354 | return -EINVAL; |
b2476490 MT |
1355 | |
1356 | mutex_lock(&prepare_lock); | |
1357 | ||
1358 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1359 | if (__clk_lookup(clk->name)) { |
1360 | pr_debug("%s: clk %s already initialized\n", | |
1361 | __func__, clk->name); | |
1362 | ret = -EEXIST; | |
b2476490 | 1363 | goto out; |
d1302a36 | 1364 | } |
b2476490 | 1365 | |
d4d7e3dd MT |
1366 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1367 | if (clk->ops->set_rate && | |
1368 | !(clk->ops->round_rate && clk->ops->recalc_rate)) { | |
1369 | pr_warning("%s: %s must implement .round_rate & .recalc_rate\n", | |
1370 | __func__, clk->name); | |
d1302a36 | 1371 | ret = -EINVAL; |
d4d7e3dd MT |
1372 | goto out; |
1373 | } | |
1374 | ||
1375 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1376 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1377 | __func__, clk->name); | |
d1302a36 | 1378 | ret = -EINVAL; |
d4d7e3dd MT |
1379 | goto out; |
1380 | } | |
1381 | ||
b2476490 MT |
1382 | /* throw a WARN if any entries in parent_names are NULL */ |
1383 | for (i = 0; i < clk->num_parents; i++) | |
1384 | WARN(!clk->parent_names[i], | |
1385 | "%s: invalid NULL in %s's .parent_names\n", | |
1386 | __func__, clk->name); | |
1387 | ||
1388 | /* | |
1389 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1390 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1391 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1392 | * must always check for a NULL pointer and try to populate it if | |
1393 | * necessary. | |
1394 | * | |
1395 | * If clk->parents is not NULL we skip this entire block. This allows | |
1396 | * for clock drivers to statically initialize clk->parents. | |
1397 | */ | |
9ca1c5a4 RN |
1398 | if (clk->num_parents > 1 && !clk->parents) { |
1399 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), | |
b2476490 MT |
1400 | GFP_KERNEL); |
1401 | /* | |
1402 | * __clk_lookup returns NULL for parents that have not been | |
1403 | * clk_init'd; thus any access to clk->parents[] must check | |
1404 | * for a NULL pointer. We can always perform lazy lookups for | |
1405 | * missing parents later on. | |
1406 | */ | |
1407 | if (clk->parents) | |
1408 | for (i = 0; i < clk->num_parents; i++) | |
1409 | clk->parents[i] = | |
1410 | __clk_lookup(clk->parent_names[i]); | |
1411 | } | |
1412 | ||
1413 | clk->parent = __clk_init_parent(clk); | |
1414 | ||
1415 | /* | |
1416 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1417 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1418 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1419 | * clk list. | |
1420 | * | |
1421 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1422 | * clocks and re-parent any that are children of the clock currently | |
1423 | * being clk_init'd. | |
1424 | */ | |
1425 | if (clk->parent) | |
1426 | hlist_add_head(&clk->child_node, | |
1427 | &clk->parent->children); | |
1428 | else if (clk->flags & CLK_IS_ROOT) | |
1429 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1430 | else | |
1431 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1432 | ||
1433 | /* | |
1434 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1435 | * simple clocks and lazy developers the default fallback is to use the | |
1436 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1437 | * then rate is set to zero. | |
1438 | */ | |
1439 | if (clk->ops->recalc_rate) | |
1440 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1441 | __clk_get_rate(clk->parent)); | |
1442 | else if (clk->parent) | |
1443 | clk->rate = clk->parent->rate; | |
1444 | else | |
1445 | clk->rate = 0; | |
1446 | ||
1447 | /* | |
1448 | * walk the list of orphan clocks and reparent any that are children of | |
1449 | * this clock | |
1450 | */ | |
1f61e5f1 MF |
1451 | hlist_for_each_entry_safe(orphan, tmp, tmp2, &clk_orphan_list, child_node) { |
1452 | if (orphan->ops->get_parent) { | |
1453 | i = orphan->ops->get_parent(orphan->hw); | |
1454 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1455 | __clk_reparent(orphan, clk); | |
1456 | continue; | |
1457 | } | |
1458 | ||
b2476490 MT |
1459 | for (i = 0; i < orphan->num_parents; i++) |
1460 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1461 | __clk_reparent(orphan, clk); | |
1462 | break; | |
1463 | } | |
1f61e5f1 | 1464 | } |
b2476490 MT |
1465 | |
1466 | /* | |
1467 | * optional platform-specific magic | |
1468 | * | |
1469 | * The .init callback is not used by any of the basic clock types, but | |
1470 | * exists for weird hardware that must perform initialization magic. | |
1471 | * Please consider other ways of solving initialization problems before | |
1472 | * using this callback, as it's use is discouraged. | |
1473 | */ | |
1474 | if (clk->ops->init) | |
1475 | clk->ops->init(clk->hw); | |
1476 | ||
1477 | clk_debug_register(clk); | |
1478 | ||
1479 | out: | |
1480 | mutex_unlock(&prepare_lock); | |
1481 | ||
d1302a36 | 1482 | return ret; |
b2476490 MT |
1483 | } |
1484 | ||
0197b3ea SK |
1485 | /** |
1486 | * __clk_register - register a clock and return a cookie. | |
1487 | * | |
1488 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1489 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1490 | * of the struct clk need to be initialized. | |
1491 | * | |
1492 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1493 | * data. | |
1494 | * | |
1495 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1496 | * very large numbers of clocks that need to be statically initialized. It is | |
1497 | * a layering violation to include clk-private.h from any code which implements | |
1498 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
1499 | * separate C file from the logic that implements it's operations. Returns 0 | |
1500 | * on success, otherwise an error code. | |
1501 | */ | |
1502 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
1503 | { | |
1504 | int ret; | |
1505 | struct clk *clk; | |
1506 | ||
1507 | clk = hw->clk; | |
1508 | clk->name = hw->init->name; | |
1509 | clk->ops = hw->init->ops; | |
1510 | clk->hw = hw; | |
1511 | clk->flags = hw->init->flags; | |
1512 | clk->parent_names = hw->init->parent_names; | |
1513 | clk->num_parents = hw->init->num_parents; | |
1514 | ||
1515 | ret = __clk_init(dev, clk); | |
1516 | if (ret) | |
1517 | return ERR_PTR(ret); | |
1518 | ||
1519 | return clk; | |
1520 | } | |
1521 | EXPORT_SYMBOL_GPL(__clk_register); | |
1522 | ||
46c8773a | 1523 | static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk) |
b2476490 | 1524 | { |
d1302a36 | 1525 | int i, ret; |
b2476490 | 1526 | |
0197b3ea SK |
1527 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
1528 | if (!clk->name) { | |
1529 | pr_err("%s: could not allocate clk->name\n", __func__); | |
1530 | ret = -ENOMEM; | |
1531 | goto fail_name; | |
1532 | } | |
1533 | clk->ops = hw->init->ops; | |
b2476490 | 1534 | clk->hw = hw; |
0197b3ea SK |
1535 | clk->flags = hw->init->flags; |
1536 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
1537 | hw->clk = clk; |
1538 | ||
d1302a36 | 1539 | /* allocate local copy in case parent_names is __initdata */ |
0197b3ea | 1540 | clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents), |
d1302a36 MT |
1541 | GFP_KERNEL); |
1542 | ||
1543 | if (!clk->parent_names) { | |
1544 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
1545 | ret = -ENOMEM; | |
1546 | goto fail_parent_names; | |
1547 | } | |
1548 | ||
1549 | ||
1550 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea SK |
1551 | for (i = 0; i < clk->num_parents; i++) { |
1552 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], | |
1553 | GFP_KERNEL); | |
d1302a36 MT |
1554 | if (!clk->parent_names[i]) { |
1555 | pr_err("%s: could not copy parent_names\n", __func__); | |
1556 | ret = -ENOMEM; | |
1557 | goto fail_parent_names_copy; | |
1558 | } | |
1559 | } | |
1560 | ||
1561 | ret = __clk_init(dev, clk); | |
1562 | if (!ret) | |
46c8773a | 1563 | return 0; |
b2476490 | 1564 | |
d1302a36 MT |
1565 | fail_parent_names_copy: |
1566 | while (--i >= 0) | |
1567 | kfree(clk->parent_names[i]); | |
1568 | kfree(clk->parent_names); | |
1569 | fail_parent_names: | |
0197b3ea SK |
1570 | kfree(clk->name); |
1571 | fail_name: | |
46c8773a SB |
1572 | return ret; |
1573 | } | |
1574 | ||
1575 | /** | |
1576 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
1577 | * @dev: device that is registering this clock | |
1578 | * @hw: link to hardware-specific clock data | |
1579 | * | |
1580 | * clk_register is the primary interface for populating the clock tree with new | |
1581 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
1582 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
1583 | * rest of the clock API. In the event of an error clk_register will return an | |
1584 | * error code; drivers must test for an error code after calling clk_register. | |
1585 | */ | |
1586 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
1587 | { | |
1588 | int ret; | |
1589 | struct clk *clk; | |
1590 | ||
1591 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
1592 | if (!clk) { | |
1593 | pr_err("%s: could not allocate clk\n", __func__); | |
1594 | ret = -ENOMEM; | |
1595 | goto fail_out; | |
1596 | } | |
1597 | ||
1598 | ret = _clk_register(dev, hw, clk); | |
1599 | if (!ret) | |
1600 | return clk; | |
1601 | ||
d1302a36 MT |
1602 | kfree(clk); |
1603 | fail_out: | |
1604 | return ERR_PTR(ret); | |
b2476490 MT |
1605 | } |
1606 | EXPORT_SYMBOL_GPL(clk_register); | |
1607 | ||
1df5c939 MB |
1608 | /** |
1609 | * clk_unregister - unregister a currently registered clock | |
1610 | * @clk: clock to unregister | |
1611 | * | |
1612 | * Currently unimplemented. | |
1613 | */ | |
1614 | void clk_unregister(struct clk *clk) {} | |
1615 | EXPORT_SYMBOL_GPL(clk_unregister); | |
1616 | ||
46c8773a SB |
1617 | static void devm_clk_release(struct device *dev, void *res) |
1618 | { | |
1619 | clk_unregister(res); | |
1620 | } | |
1621 | ||
1622 | /** | |
1623 | * devm_clk_register - resource managed clk_register() | |
1624 | * @dev: device that is registering this clock | |
1625 | * @hw: link to hardware-specific clock data | |
1626 | * | |
1627 | * Managed clk_register(). Clocks returned from this function are | |
1628 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
1629 | * more information. | |
1630 | */ | |
1631 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
1632 | { | |
1633 | struct clk *clk; | |
1634 | int ret; | |
1635 | ||
1636 | clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL); | |
1637 | if (!clk) | |
1638 | return ERR_PTR(-ENOMEM); | |
1639 | ||
1640 | ret = _clk_register(dev, hw, clk); | |
1641 | if (!ret) { | |
1642 | devres_add(dev, clk); | |
1643 | } else { | |
1644 | devres_free(clk); | |
1645 | clk = ERR_PTR(ret); | |
1646 | } | |
1647 | ||
1648 | return clk; | |
1649 | } | |
1650 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
1651 | ||
1652 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
1653 | { | |
1654 | struct clk *c = res; | |
1655 | if (WARN_ON(!c)) | |
1656 | return 0; | |
1657 | return c == data; | |
1658 | } | |
1659 | ||
1660 | /** | |
1661 | * devm_clk_unregister - resource managed clk_unregister() | |
1662 | * @clk: clock to unregister | |
1663 | * | |
1664 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
1665 | * this function will not need to be called and the resource management | |
1666 | * code will ensure that the resource is freed. | |
1667 | */ | |
1668 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
1669 | { | |
1670 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
1671 | } | |
1672 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
1673 | ||
b2476490 MT |
1674 | /*** clk rate change notifiers ***/ |
1675 | ||
1676 | /** | |
1677 | * clk_notifier_register - add a clk rate change notifier | |
1678 | * @clk: struct clk * to watch | |
1679 | * @nb: struct notifier_block * with callback info | |
1680 | * | |
1681 | * Request notification when clk's rate changes. This uses an SRCU | |
1682 | * notifier because we want it to block and notifier unregistrations are | |
1683 | * uncommon. The callbacks associated with the notifier must not | |
1684 | * re-enter into the clk framework by calling any top-level clk APIs; | |
1685 | * this will cause a nested prepare_lock mutex. | |
1686 | * | |
1687 | * Pre-change notifier callbacks will be passed the current, pre-change | |
1688 | * rate of the clk via struct clk_notifier_data.old_rate. The new, | |
1689 | * post-change rate of the clk is passed via struct | |
1690 | * clk_notifier_data.new_rate. | |
1691 | * | |
1692 | * Post-change notifiers will pass the now-current, post-change rate of | |
1693 | * the clk in both struct clk_notifier_data.old_rate and struct | |
1694 | * clk_notifier_data.new_rate. | |
1695 | * | |
1696 | * Abort-change notifiers are effectively the opposite of pre-change | |
1697 | * notifiers: the original pre-change clk rate is passed in via struct | |
1698 | * clk_notifier_data.new_rate and the failed post-change rate is passed | |
1699 | * in via struct clk_notifier_data.old_rate. | |
1700 | * | |
1701 | * clk_notifier_register() must be called from non-atomic context. | |
1702 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
1703 | * allocation failure; otherwise, passes along the return value of | |
1704 | * srcu_notifier_chain_register(). | |
1705 | */ | |
1706 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
1707 | { | |
1708 | struct clk_notifier *cn; | |
1709 | int ret = -ENOMEM; | |
1710 | ||
1711 | if (!clk || !nb) | |
1712 | return -EINVAL; | |
1713 | ||
1714 | mutex_lock(&prepare_lock); | |
1715 | ||
1716 | /* search the list of notifiers for this clk */ | |
1717 | list_for_each_entry(cn, &clk_notifier_list, node) | |
1718 | if (cn->clk == clk) | |
1719 | break; | |
1720 | ||
1721 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
1722 | if (cn->clk != clk) { | |
1723 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
1724 | if (!cn) | |
1725 | goto out; | |
1726 | ||
1727 | cn->clk = clk; | |
1728 | srcu_init_notifier_head(&cn->notifier_head); | |
1729 | ||
1730 | list_add(&cn->node, &clk_notifier_list); | |
1731 | } | |
1732 | ||
1733 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
1734 | ||
1735 | clk->notifier_count++; | |
1736 | ||
1737 | out: | |
1738 | mutex_unlock(&prepare_lock); | |
1739 | ||
1740 | return ret; | |
1741 | } | |
1742 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
1743 | ||
1744 | /** | |
1745 | * clk_notifier_unregister - remove a clk rate change notifier | |
1746 | * @clk: struct clk * | |
1747 | * @nb: struct notifier_block * with callback info | |
1748 | * | |
1749 | * Request no further notification for changes to 'clk' and frees memory | |
1750 | * allocated in clk_notifier_register. | |
1751 | * | |
1752 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
1753 | * along the return value of srcu_notifier_chain_unregister(). | |
1754 | */ | |
1755 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
1756 | { | |
1757 | struct clk_notifier *cn = NULL; | |
1758 | int ret = -EINVAL; | |
1759 | ||
1760 | if (!clk || !nb) | |
1761 | return -EINVAL; | |
1762 | ||
1763 | mutex_lock(&prepare_lock); | |
1764 | ||
1765 | list_for_each_entry(cn, &clk_notifier_list, node) | |
1766 | if (cn->clk == clk) | |
1767 | break; | |
1768 | ||
1769 | if (cn->clk == clk) { | |
1770 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
1771 | ||
1772 | clk->notifier_count--; | |
1773 | ||
1774 | /* XXX the notifier code should handle this better */ | |
1775 | if (!cn->notifier_head.head) { | |
1776 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
1777 | kfree(cn); | |
1778 | } | |
1779 | ||
1780 | } else { | |
1781 | ret = -ENOENT; | |
1782 | } | |
1783 | ||
1784 | mutex_unlock(&prepare_lock); | |
1785 | ||
1786 | return ret; | |
1787 | } | |
1788 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
1789 | |
1790 | #ifdef CONFIG_OF | |
1791 | /** | |
1792 | * struct of_clk_provider - Clock provider registration structure | |
1793 | * @link: Entry in global list of clock providers | |
1794 | * @node: Pointer to device tree node of clock provider | |
1795 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
1796 | * given clock specifier | |
1797 | * @data: context pointer to be passed into @get callback | |
1798 | */ | |
1799 | struct of_clk_provider { | |
1800 | struct list_head link; | |
1801 | ||
1802 | struct device_node *node; | |
1803 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
1804 | void *data; | |
1805 | }; | |
1806 | ||
f2f6c255 PG |
1807 | extern struct of_device_id __clk_of_table[]; |
1808 | ||
1809 | static const struct of_device_id __clk_of_table_sentinel | |
1810 | __used __section(__clk_of_table_end); | |
1811 | ||
766e6a4e GL |
1812 | static LIST_HEAD(of_clk_providers); |
1813 | static DEFINE_MUTEX(of_clk_lock); | |
1814 | ||
1815 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
1816 | void *data) | |
1817 | { | |
1818 | return data; | |
1819 | } | |
1820 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
1821 | ||
494bfec9 SG |
1822 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
1823 | { | |
1824 | struct clk_onecell_data *clk_data = data; | |
1825 | unsigned int idx = clkspec->args[0]; | |
1826 | ||
1827 | if (idx >= clk_data->clk_num) { | |
1828 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
1829 | return ERR_PTR(-EINVAL); | |
1830 | } | |
1831 | ||
1832 | return clk_data->clks[idx]; | |
1833 | } | |
1834 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
1835 | ||
766e6a4e GL |
1836 | /** |
1837 | * of_clk_add_provider() - Register a clock provider for a node | |
1838 | * @np: Device node pointer associated with clock provider | |
1839 | * @clk_src_get: callback for decoding clock | |
1840 | * @data: context pointer for @clk_src_get callback. | |
1841 | */ | |
1842 | int of_clk_add_provider(struct device_node *np, | |
1843 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
1844 | void *data), | |
1845 | void *data) | |
1846 | { | |
1847 | struct of_clk_provider *cp; | |
1848 | ||
1849 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
1850 | if (!cp) | |
1851 | return -ENOMEM; | |
1852 | ||
1853 | cp->node = of_node_get(np); | |
1854 | cp->data = data; | |
1855 | cp->get = clk_src_get; | |
1856 | ||
1857 | mutex_lock(&of_clk_lock); | |
1858 | list_add(&cp->link, &of_clk_providers); | |
1859 | mutex_unlock(&of_clk_lock); | |
1860 | pr_debug("Added clock from %s\n", np->full_name); | |
1861 | ||
1862 | return 0; | |
1863 | } | |
1864 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
1865 | ||
1866 | /** | |
1867 | * of_clk_del_provider() - Remove a previously registered clock provider | |
1868 | * @np: Device node pointer associated with clock provider | |
1869 | */ | |
1870 | void of_clk_del_provider(struct device_node *np) | |
1871 | { | |
1872 | struct of_clk_provider *cp; | |
1873 | ||
1874 | mutex_lock(&of_clk_lock); | |
1875 | list_for_each_entry(cp, &of_clk_providers, link) { | |
1876 | if (cp->node == np) { | |
1877 | list_del(&cp->link); | |
1878 | of_node_put(cp->node); | |
1879 | kfree(cp); | |
1880 | break; | |
1881 | } | |
1882 | } | |
1883 | mutex_unlock(&of_clk_lock); | |
1884 | } | |
1885 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
1886 | ||
1887 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
1888 | { | |
1889 | struct of_clk_provider *provider; | |
1890 | struct clk *clk = ERR_PTR(-ENOENT); | |
1891 | ||
1892 | /* Check if we have such a provider in our array */ | |
1893 | mutex_lock(&of_clk_lock); | |
1894 | list_for_each_entry(provider, &of_clk_providers, link) { | |
1895 | if (provider->node == clkspec->np) | |
1896 | clk = provider->get(clkspec, provider->data); | |
1897 | if (!IS_ERR(clk)) | |
1898 | break; | |
1899 | } | |
1900 | mutex_unlock(&of_clk_lock); | |
1901 | ||
1902 | return clk; | |
1903 | } | |
1904 | ||
1905 | const char *of_clk_get_parent_name(struct device_node *np, int index) | |
1906 | { | |
1907 | struct of_phandle_args clkspec; | |
1908 | const char *clk_name; | |
1909 | int rc; | |
1910 | ||
1911 | if (index < 0) | |
1912 | return NULL; | |
1913 | ||
1914 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
1915 | &clkspec); | |
1916 | if (rc) | |
1917 | return NULL; | |
1918 | ||
1919 | if (of_property_read_string_index(clkspec.np, "clock-output-names", | |
1920 | clkspec.args_count ? clkspec.args[0] : 0, | |
1921 | &clk_name) < 0) | |
1922 | clk_name = clkspec.np->name; | |
1923 | ||
1924 | of_node_put(clkspec.np); | |
1925 | return clk_name; | |
1926 | } | |
1927 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
1928 | ||
1929 | /** | |
1930 | * of_clk_init() - Scan and init clock providers from the DT | |
1931 | * @matches: array of compatible values and init functions for providers. | |
1932 | * | |
1933 | * This function scans the device tree for matching clock providers and | |
1934 | * calls their initialization functions | |
1935 | */ | |
1936 | void __init of_clk_init(const struct of_device_id *matches) | |
1937 | { | |
1938 | struct device_node *np; | |
1939 | ||
f2f6c255 PG |
1940 | if (!matches) |
1941 | matches = __clk_of_table; | |
1942 | ||
766e6a4e GL |
1943 | for_each_matching_node(np, matches) { |
1944 | const struct of_device_id *match = of_match_node(matches, np); | |
1945 | of_clk_init_cb_t clk_init_cb = match->data; | |
1946 | clk_init_cb(np); | |
1947 | } | |
1948 | } | |
1949 | #endif |