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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; | |
1af599df PG |
55 | |
56 | if (!c) | |
57 | return; | |
58 | ||
59 | clk_summary_show_one(s, c, level); | |
60 | ||
b67bfe0d | 61 | hlist_for_each_entry(child, &c->children, child_node) |
1af599df PG |
62 | clk_summary_show_subtree(s, child, level + 1); |
63 | } | |
64 | ||
65 | static int clk_summary_show(struct seq_file *s, void *data) | |
66 | { | |
67 | struct clk *c; | |
1af599df PG |
68 | |
69 | seq_printf(s, " clock enable_cnt prepare_cnt rate\n"); | |
70 | seq_printf(s, "---------------------------------------------------------------------\n"); | |
71 | ||
72 | mutex_lock(&prepare_lock); | |
73 | ||
b67bfe0d | 74 | hlist_for_each_entry(c, &clk_root_list, child_node) |
1af599df PG |
75 | clk_summary_show_subtree(s, c, 0); |
76 | ||
b67bfe0d | 77 | hlist_for_each_entry(c, &clk_orphan_list, child_node) |
1af599df PG |
78 | clk_summary_show_subtree(s, c, 0); |
79 | ||
80 | mutex_unlock(&prepare_lock); | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
85 | ||
86 | static int clk_summary_open(struct inode *inode, struct file *file) | |
87 | { | |
88 | return single_open(file, clk_summary_show, inode->i_private); | |
89 | } | |
90 | ||
91 | static const struct file_operations clk_summary_fops = { | |
92 | .open = clk_summary_open, | |
93 | .read = seq_read, | |
94 | .llseek = seq_lseek, | |
95 | .release = single_release, | |
96 | }; | |
97 | ||
bddca894 PG |
98 | static void clk_dump_one(struct seq_file *s, struct clk *c, int level) |
99 | { | |
100 | if (!c) | |
101 | return; | |
102 | ||
103 | seq_printf(s, "\"%s\": { ", c->name); | |
104 | seq_printf(s, "\"enable_count\": %d,", c->enable_count); | |
105 | seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); | |
106 | seq_printf(s, "\"rate\": %lu", c->rate); | |
107 | } | |
108 | ||
109 | static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) | |
110 | { | |
111 | struct clk *child; | |
bddca894 PG |
112 | |
113 | if (!c) | |
114 | return; | |
115 | ||
116 | clk_dump_one(s, c, level); | |
117 | ||
b67bfe0d | 118 | hlist_for_each_entry(child, &c->children, child_node) { |
bddca894 PG |
119 | seq_printf(s, ","); |
120 | clk_dump_subtree(s, child, level + 1); | |
121 | } | |
122 | ||
123 | seq_printf(s, "}"); | |
124 | } | |
125 | ||
126 | static int clk_dump(struct seq_file *s, void *data) | |
127 | { | |
128 | struct clk *c; | |
bddca894 PG |
129 | bool first_node = true; |
130 | ||
131 | seq_printf(s, "{"); | |
132 | ||
133 | mutex_lock(&prepare_lock); | |
134 | ||
b67bfe0d | 135 | hlist_for_each_entry(c, &clk_root_list, child_node) { |
bddca894 PG |
136 | if (!first_node) |
137 | seq_printf(s, ","); | |
138 | first_node = false; | |
139 | clk_dump_subtree(s, c, 0); | |
140 | } | |
141 | ||
b67bfe0d | 142 | hlist_for_each_entry(c, &clk_orphan_list, child_node) { |
bddca894 PG |
143 | seq_printf(s, ","); |
144 | clk_dump_subtree(s, c, 0); | |
145 | } | |
146 | ||
147 | mutex_unlock(&prepare_lock); | |
148 | ||
149 | seq_printf(s, "}"); | |
150 | return 0; | |
151 | } | |
152 | ||
153 | ||
154 | static int clk_dump_open(struct inode *inode, struct file *file) | |
155 | { | |
156 | return single_open(file, clk_dump, inode->i_private); | |
157 | } | |
158 | ||
159 | static const struct file_operations clk_dump_fops = { | |
160 | .open = clk_dump_open, | |
161 | .read = seq_read, | |
162 | .llseek = seq_lseek, | |
163 | .release = single_release, | |
164 | }; | |
165 | ||
b2476490 MT |
166 | /* caller must hold prepare_lock */ |
167 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) | |
168 | { | |
169 | struct dentry *d; | |
170 | int ret = -ENOMEM; | |
171 | ||
172 | if (!clk || !pdentry) { | |
173 | ret = -EINVAL; | |
174 | goto out; | |
175 | } | |
176 | ||
177 | d = debugfs_create_dir(clk->name, pdentry); | |
178 | if (!d) | |
179 | goto out; | |
180 | ||
181 | clk->dentry = d; | |
182 | ||
183 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, | |
184 | (u32 *)&clk->rate); | |
185 | if (!d) | |
186 | goto err_out; | |
187 | ||
188 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, | |
189 | (u32 *)&clk->flags); | |
190 | if (!d) | |
191 | goto err_out; | |
192 | ||
193 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, | |
194 | (u32 *)&clk->prepare_count); | |
195 | if (!d) | |
196 | goto err_out; | |
197 | ||
198 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, | |
199 | (u32 *)&clk->enable_count); | |
200 | if (!d) | |
201 | goto err_out; | |
202 | ||
203 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, | |
204 | (u32 *)&clk->notifier_count); | |
205 | if (!d) | |
206 | goto err_out; | |
207 | ||
208 | ret = 0; | |
209 | goto out; | |
210 | ||
211 | err_out: | |
212 | debugfs_remove(clk->dentry); | |
213 | out: | |
214 | return ret; | |
215 | } | |
216 | ||
217 | /* caller must hold prepare_lock */ | |
218 | static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry) | |
219 | { | |
220 | struct clk *child; | |
b2476490 MT |
221 | int ret = -EINVAL;; |
222 | ||
223 | if (!clk || !pdentry) | |
224 | goto out; | |
225 | ||
226 | ret = clk_debug_create_one(clk, pdentry); | |
227 | ||
228 | if (ret) | |
229 | goto out; | |
230 | ||
b67bfe0d | 231 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
232 | clk_debug_create_subtree(child, clk->dentry); |
233 | ||
234 | ret = 0; | |
235 | out: | |
236 | return ret; | |
237 | } | |
238 | ||
239 | /** | |
240 | * clk_debug_register - add a clk node to the debugfs clk tree | |
241 | * @clk: the clk being added to the debugfs clk tree | |
242 | * | |
243 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been | |
244 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
245 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
246 | * | |
247 | * Caller must hold prepare_lock. Only clk_init calls this function (so | |
248 | * far) so this is taken care. | |
249 | */ | |
250 | static int clk_debug_register(struct clk *clk) | |
251 | { | |
252 | struct clk *parent; | |
253 | struct dentry *pdentry; | |
254 | int ret = 0; | |
255 | ||
256 | if (!inited) | |
257 | goto out; | |
258 | ||
259 | parent = clk->parent; | |
260 | ||
261 | /* | |
262 | * Check to see if a clk is a root clk. Also check that it is | |
263 | * safe to add this clk to debugfs | |
264 | */ | |
265 | if (!parent) | |
266 | if (clk->flags & CLK_IS_ROOT) | |
267 | pdentry = rootdir; | |
268 | else | |
269 | pdentry = orphandir; | |
270 | else | |
271 | if (parent->dentry) | |
272 | pdentry = parent->dentry; | |
273 | else | |
274 | goto out; | |
275 | ||
276 | ret = clk_debug_create_subtree(clk, pdentry); | |
277 | ||
278 | out: | |
279 | return ret; | |
280 | } | |
281 | ||
282 | /** | |
283 | * clk_debug_init - lazily create the debugfs clk tree visualization | |
284 | * | |
285 | * clks are often initialized very early during boot before memory can | |
286 | * be dynamically allocated and well before debugfs is setup. | |
287 | * clk_debug_init walks the clk tree hierarchy while holding | |
288 | * prepare_lock and creates the topology as part of a late_initcall, | |
289 | * thus insuring that clks initialized very early will still be | |
290 | * represented in the debugfs clk tree. This function should only be | |
291 | * called once at boot-time, and all other clks added dynamically will | |
292 | * be done so with clk_debug_register. | |
293 | */ | |
294 | static int __init clk_debug_init(void) | |
295 | { | |
296 | struct clk *clk; | |
1af599df | 297 | struct dentry *d; |
b2476490 MT |
298 | |
299 | rootdir = debugfs_create_dir("clk", NULL); | |
300 | ||
301 | if (!rootdir) | |
302 | return -ENOMEM; | |
303 | ||
1af599df PG |
304 | d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, NULL, |
305 | &clk_summary_fops); | |
306 | if (!d) | |
307 | return -ENOMEM; | |
308 | ||
bddca894 PG |
309 | d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, NULL, |
310 | &clk_dump_fops); | |
311 | if (!d) | |
312 | return -ENOMEM; | |
313 | ||
b2476490 MT |
314 | orphandir = debugfs_create_dir("orphans", rootdir); |
315 | ||
316 | if (!orphandir) | |
317 | return -ENOMEM; | |
318 | ||
319 | mutex_lock(&prepare_lock); | |
320 | ||
b67bfe0d | 321 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
322 | clk_debug_create_subtree(clk, rootdir); |
323 | ||
b67bfe0d | 324 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
b2476490 MT |
325 | clk_debug_create_subtree(clk, orphandir); |
326 | ||
327 | inited = 1; | |
328 | ||
329 | mutex_unlock(&prepare_lock); | |
330 | ||
331 | return 0; | |
332 | } | |
333 | late_initcall(clk_debug_init); | |
334 | #else | |
335 | static inline int clk_debug_register(struct clk *clk) { return 0; } | |
70d347e6 | 336 | #endif |
b2476490 | 337 | |
1c155b3d UH |
338 | /* caller must hold prepare_lock */ |
339 | static void clk_unprepare_unused_subtree(struct clk *clk) | |
340 | { | |
341 | struct clk *child; | |
342 | ||
343 | if (!clk) | |
344 | return; | |
345 | ||
346 | hlist_for_each_entry(child, &clk->children, child_node) | |
347 | clk_unprepare_unused_subtree(child); | |
348 | ||
349 | if (clk->prepare_count) | |
350 | return; | |
351 | ||
352 | if (clk->flags & CLK_IGNORE_UNUSED) | |
353 | return; | |
354 | ||
3cc8247f UH |
355 | if (__clk_is_prepared(clk)) { |
356 | if (clk->ops->unprepare_unused) | |
357 | clk->ops->unprepare_unused(clk->hw); | |
358 | else if (clk->ops->unprepare) | |
1c155b3d | 359 | clk->ops->unprepare(clk->hw); |
3cc8247f | 360 | } |
1c155b3d UH |
361 | } |
362 | ||
b2476490 MT |
363 | /* caller must hold prepare_lock */ |
364 | static void clk_disable_unused_subtree(struct clk *clk) | |
365 | { | |
366 | struct clk *child; | |
b2476490 MT |
367 | unsigned long flags; |
368 | ||
369 | if (!clk) | |
370 | goto out; | |
371 | ||
b67bfe0d | 372 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
373 | clk_disable_unused_subtree(child); |
374 | ||
375 | spin_lock_irqsave(&enable_lock, flags); | |
376 | ||
377 | if (clk->enable_count) | |
378 | goto unlock_out; | |
379 | ||
380 | if (clk->flags & CLK_IGNORE_UNUSED) | |
381 | goto unlock_out; | |
382 | ||
7c045a55 MT |
383 | /* |
384 | * some gate clocks have special needs during the disable-unused | |
385 | * sequence. call .disable_unused if available, otherwise fall | |
386 | * back to .disable | |
387 | */ | |
388 | if (__clk_is_enabled(clk)) { | |
389 | if (clk->ops->disable_unused) | |
390 | clk->ops->disable_unused(clk->hw); | |
391 | else if (clk->ops->disable) | |
392 | clk->ops->disable(clk->hw); | |
393 | } | |
b2476490 MT |
394 | |
395 | unlock_out: | |
396 | spin_unlock_irqrestore(&enable_lock, flags); | |
397 | ||
398 | out: | |
399 | return; | |
400 | } | |
401 | ||
402 | static int clk_disable_unused(void) | |
403 | { | |
404 | struct clk *clk; | |
b2476490 MT |
405 | |
406 | mutex_lock(&prepare_lock); | |
407 | ||
b67bfe0d | 408 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
409 | clk_disable_unused_subtree(clk); |
410 | ||
b67bfe0d | 411 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
b2476490 MT |
412 | clk_disable_unused_subtree(clk); |
413 | ||
1c155b3d UH |
414 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
415 | clk_unprepare_unused_subtree(clk); | |
416 | ||
417 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) | |
418 | clk_unprepare_unused_subtree(clk); | |
419 | ||
b2476490 MT |
420 | mutex_unlock(&prepare_lock); |
421 | ||
422 | return 0; | |
423 | } | |
424 | late_initcall(clk_disable_unused); | |
b2476490 MT |
425 | |
426 | /*** helper functions ***/ | |
427 | ||
65800b2c | 428 | const char *__clk_get_name(struct clk *clk) |
b2476490 MT |
429 | { |
430 | return !clk ? NULL : clk->name; | |
431 | } | |
4895084c | 432 | EXPORT_SYMBOL_GPL(__clk_get_name); |
b2476490 | 433 | |
65800b2c | 434 | struct clk_hw *__clk_get_hw(struct clk *clk) |
b2476490 MT |
435 | { |
436 | return !clk ? NULL : clk->hw; | |
437 | } | |
438 | ||
65800b2c | 439 | u8 __clk_get_num_parents(struct clk *clk) |
b2476490 | 440 | { |
2ac6b1f5 | 441 | return !clk ? 0 : clk->num_parents; |
b2476490 MT |
442 | } |
443 | ||
65800b2c | 444 | struct clk *__clk_get_parent(struct clk *clk) |
b2476490 MT |
445 | { |
446 | return !clk ? NULL : clk->parent; | |
447 | } | |
448 | ||
65800b2c | 449 | unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 450 | { |
2ac6b1f5 | 451 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
452 | } |
453 | ||
65800b2c | 454 | unsigned int __clk_get_prepare_count(struct clk *clk) |
b2476490 | 455 | { |
2ac6b1f5 | 456 | return !clk ? 0 : clk->prepare_count; |
b2476490 MT |
457 | } |
458 | ||
459 | unsigned long __clk_get_rate(struct clk *clk) | |
460 | { | |
461 | unsigned long ret; | |
462 | ||
463 | if (!clk) { | |
34e44fe8 | 464 | ret = 0; |
b2476490 MT |
465 | goto out; |
466 | } | |
467 | ||
468 | ret = clk->rate; | |
469 | ||
470 | if (clk->flags & CLK_IS_ROOT) | |
471 | goto out; | |
472 | ||
473 | if (!clk->parent) | |
34e44fe8 | 474 | ret = 0; |
b2476490 MT |
475 | |
476 | out: | |
477 | return ret; | |
478 | } | |
479 | ||
65800b2c | 480 | unsigned long __clk_get_flags(struct clk *clk) |
b2476490 | 481 | { |
2ac6b1f5 | 482 | return !clk ? 0 : clk->flags; |
b2476490 MT |
483 | } |
484 | ||
3d6ee287 UH |
485 | bool __clk_is_prepared(struct clk *clk) |
486 | { | |
487 | int ret; | |
488 | ||
489 | if (!clk) | |
490 | return false; | |
491 | ||
492 | /* | |
493 | * .is_prepared is optional for clocks that can prepare | |
494 | * fall back to software usage counter if it is missing | |
495 | */ | |
496 | if (!clk->ops->is_prepared) { | |
497 | ret = clk->prepare_count ? 1 : 0; | |
498 | goto out; | |
499 | } | |
500 | ||
501 | ret = clk->ops->is_prepared(clk->hw); | |
502 | out: | |
503 | return !!ret; | |
504 | } | |
505 | ||
2ac6b1f5 | 506 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
507 | { |
508 | int ret; | |
509 | ||
510 | if (!clk) | |
2ac6b1f5 | 511 | return false; |
b2476490 MT |
512 | |
513 | /* | |
514 | * .is_enabled is only mandatory for clocks that gate | |
515 | * fall back to software usage counter if .is_enabled is missing | |
516 | */ | |
517 | if (!clk->ops->is_enabled) { | |
518 | ret = clk->enable_count ? 1 : 0; | |
519 | goto out; | |
520 | } | |
521 | ||
522 | ret = clk->ops->is_enabled(clk->hw); | |
523 | out: | |
2ac6b1f5 | 524 | return !!ret; |
b2476490 MT |
525 | } |
526 | ||
527 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
528 | { | |
529 | struct clk *child; | |
530 | struct clk *ret; | |
b2476490 MT |
531 | |
532 | if (!strcmp(clk->name, name)) | |
533 | return clk; | |
534 | ||
b67bfe0d | 535 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
536 | ret = __clk_lookup_subtree(name, child); |
537 | if (ret) | |
538 | return ret; | |
539 | } | |
540 | ||
541 | return NULL; | |
542 | } | |
543 | ||
544 | struct clk *__clk_lookup(const char *name) | |
545 | { | |
546 | struct clk *root_clk; | |
547 | struct clk *ret; | |
b2476490 MT |
548 | |
549 | if (!name) | |
550 | return NULL; | |
551 | ||
552 | /* search the 'proper' clk tree first */ | |
b67bfe0d | 553 | hlist_for_each_entry(root_clk, &clk_root_list, child_node) { |
b2476490 MT |
554 | ret = __clk_lookup_subtree(name, root_clk); |
555 | if (ret) | |
556 | return ret; | |
557 | } | |
558 | ||
559 | /* if not found, then search the orphan tree */ | |
b67bfe0d | 560 | hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { |
b2476490 MT |
561 | ret = __clk_lookup_subtree(name, root_clk); |
562 | if (ret) | |
563 | return ret; | |
564 | } | |
565 | ||
566 | return NULL; | |
567 | } | |
568 | ||
569 | /*** clk api ***/ | |
570 | ||
571 | void __clk_unprepare(struct clk *clk) | |
572 | { | |
573 | if (!clk) | |
574 | return; | |
575 | ||
576 | if (WARN_ON(clk->prepare_count == 0)) | |
577 | return; | |
578 | ||
579 | if (--clk->prepare_count > 0) | |
580 | return; | |
581 | ||
582 | WARN_ON(clk->enable_count > 0); | |
583 | ||
584 | if (clk->ops->unprepare) | |
585 | clk->ops->unprepare(clk->hw); | |
586 | ||
587 | __clk_unprepare(clk->parent); | |
588 | } | |
589 | ||
590 | /** | |
591 | * clk_unprepare - undo preparation of a clock source | |
592 | * @clk: the clk being unprepare | |
593 | * | |
594 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
595 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
596 | * if the operation may sleep. One example is a clk which is accessed over | |
597 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
598 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
599 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
600 | */ | |
601 | void clk_unprepare(struct clk *clk) | |
602 | { | |
603 | mutex_lock(&prepare_lock); | |
604 | __clk_unprepare(clk); | |
605 | mutex_unlock(&prepare_lock); | |
606 | } | |
607 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
608 | ||
609 | int __clk_prepare(struct clk *clk) | |
610 | { | |
611 | int ret = 0; | |
612 | ||
613 | if (!clk) | |
614 | return 0; | |
615 | ||
616 | if (clk->prepare_count == 0) { | |
617 | ret = __clk_prepare(clk->parent); | |
618 | if (ret) | |
619 | return ret; | |
620 | ||
621 | if (clk->ops->prepare) { | |
622 | ret = clk->ops->prepare(clk->hw); | |
623 | if (ret) { | |
624 | __clk_unprepare(clk->parent); | |
625 | return ret; | |
626 | } | |
627 | } | |
628 | } | |
629 | ||
630 | clk->prepare_count++; | |
631 | ||
632 | return 0; | |
633 | } | |
634 | ||
635 | /** | |
636 | * clk_prepare - prepare a clock source | |
637 | * @clk: the clk being prepared | |
638 | * | |
639 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
640 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
641 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
642 | * the complex case a clk ungate operation may require a fast and a slow part. | |
643 | * It is this reason that clk_prepare and clk_enable are not mutually | |
644 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
645 | * Returns 0 on success, -EERROR otherwise. | |
646 | */ | |
647 | int clk_prepare(struct clk *clk) | |
648 | { | |
649 | int ret; | |
650 | ||
651 | mutex_lock(&prepare_lock); | |
652 | ret = __clk_prepare(clk); | |
653 | mutex_unlock(&prepare_lock); | |
654 | ||
655 | return ret; | |
656 | } | |
657 | EXPORT_SYMBOL_GPL(clk_prepare); | |
658 | ||
659 | static void __clk_disable(struct clk *clk) | |
660 | { | |
661 | if (!clk) | |
662 | return; | |
663 | ||
e47c6a34 FW |
664 | if (WARN_ON(IS_ERR(clk))) |
665 | return; | |
666 | ||
b2476490 MT |
667 | if (WARN_ON(clk->enable_count == 0)) |
668 | return; | |
669 | ||
670 | if (--clk->enable_count > 0) | |
671 | return; | |
672 | ||
673 | if (clk->ops->disable) | |
674 | clk->ops->disable(clk->hw); | |
675 | ||
676 | __clk_disable(clk->parent); | |
677 | } | |
678 | ||
679 | /** | |
680 | * clk_disable - gate a clock | |
681 | * @clk: the clk being gated | |
682 | * | |
683 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
684 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
685 | * clk if the operation is fast and will never sleep. One example is a | |
686 | * SoC-internal clk which is controlled via simple register writes. In the | |
687 | * complex case a clk gate operation may require a fast and a slow part. It is | |
688 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
689 | * In fact clk_disable must be called before clk_unprepare. | |
690 | */ | |
691 | void clk_disable(struct clk *clk) | |
692 | { | |
693 | unsigned long flags; | |
694 | ||
695 | spin_lock_irqsave(&enable_lock, flags); | |
696 | __clk_disable(clk); | |
697 | spin_unlock_irqrestore(&enable_lock, flags); | |
698 | } | |
699 | EXPORT_SYMBOL_GPL(clk_disable); | |
700 | ||
701 | static int __clk_enable(struct clk *clk) | |
702 | { | |
703 | int ret = 0; | |
704 | ||
705 | if (!clk) | |
706 | return 0; | |
707 | ||
708 | if (WARN_ON(clk->prepare_count == 0)) | |
709 | return -ESHUTDOWN; | |
710 | ||
711 | if (clk->enable_count == 0) { | |
712 | ret = __clk_enable(clk->parent); | |
713 | ||
714 | if (ret) | |
715 | return ret; | |
716 | ||
717 | if (clk->ops->enable) { | |
718 | ret = clk->ops->enable(clk->hw); | |
719 | if (ret) { | |
720 | __clk_disable(clk->parent); | |
721 | return ret; | |
722 | } | |
723 | } | |
724 | } | |
725 | ||
726 | clk->enable_count++; | |
727 | return 0; | |
728 | } | |
729 | ||
730 | /** | |
731 | * clk_enable - ungate a clock | |
732 | * @clk: the clk being ungated | |
733 | * | |
734 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
735 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
736 | * if the operation will never sleep. One example is a SoC-internal clk which | |
737 | * is controlled via simple register writes. In the complex case a clk ungate | |
738 | * operation may require a fast and a slow part. It is this reason that | |
739 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
740 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
741 | * otherwise. | |
742 | */ | |
743 | int clk_enable(struct clk *clk) | |
744 | { | |
745 | unsigned long flags; | |
746 | int ret; | |
747 | ||
748 | spin_lock_irqsave(&enable_lock, flags); | |
749 | ret = __clk_enable(clk); | |
750 | spin_unlock_irqrestore(&enable_lock, flags); | |
751 | ||
752 | return ret; | |
753 | } | |
754 | EXPORT_SYMBOL_GPL(clk_enable); | |
755 | ||
b2476490 MT |
756 | /** |
757 | * __clk_round_rate - round the given rate for a clk | |
758 | * @clk: round the rate of this clock | |
759 | * | |
760 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
761 | */ | |
762 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
763 | { | |
81536e07 | 764 | unsigned long parent_rate = 0; |
b2476490 MT |
765 | |
766 | if (!clk) | |
2ac6b1f5 | 767 | return 0; |
b2476490 | 768 | |
f4d8af2e SG |
769 | if (!clk->ops->round_rate) { |
770 | if (clk->flags & CLK_SET_RATE_PARENT) | |
771 | return __clk_round_rate(clk->parent, rate); | |
772 | else | |
773 | return clk->rate; | |
774 | } | |
b2476490 | 775 | |
81536e07 SG |
776 | if (clk->parent) |
777 | parent_rate = clk->parent->rate; | |
778 | ||
779 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); | |
b2476490 MT |
780 | } |
781 | ||
782 | /** | |
783 | * clk_round_rate - round the given rate for a clk | |
784 | * @clk: the clk for which we are rounding a rate | |
785 | * @rate: the rate which is to be rounded | |
786 | * | |
787 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
788 | * use which is then returned. If clk doesn't support round_rate operation | |
789 | * then the parent rate is returned. | |
790 | */ | |
791 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
792 | { | |
793 | unsigned long ret; | |
794 | ||
795 | mutex_lock(&prepare_lock); | |
796 | ret = __clk_round_rate(clk, rate); | |
797 | mutex_unlock(&prepare_lock); | |
798 | ||
799 | return ret; | |
800 | } | |
801 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
802 | ||
803 | /** | |
804 | * __clk_notify - call clk notifier chain | |
805 | * @clk: struct clk * that is changing rate | |
806 | * @msg: clk notifier type (see include/linux/clk.h) | |
807 | * @old_rate: old clk rate | |
808 | * @new_rate: new clk rate | |
809 | * | |
810 | * Triggers a notifier call chain on the clk rate-change notification | |
811 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
812 | * and current rates to the notifier callback. Intended to be called by | |
813 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
814 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
815 | * a driver returns that. | |
816 | */ | |
817 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
818 | unsigned long old_rate, unsigned long new_rate) | |
819 | { | |
820 | struct clk_notifier *cn; | |
821 | struct clk_notifier_data cnd; | |
822 | int ret = NOTIFY_DONE; | |
823 | ||
824 | cnd.clk = clk; | |
825 | cnd.old_rate = old_rate; | |
826 | cnd.new_rate = new_rate; | |
827 | ||
828 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
829 | if (cn->clk == clk) { | |
830 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
831 | &cnd); | |
832 | break; | |
833 | } | |
834 | } | |
835 | ||
836 | return ret; | |
837 | } | |
838 | ||
839 | /** | |
840 | * __clk_recalc_rates | |
841 | * @clk: first clk in the subtree | |
842 | * @msg: notification type (see include/linux/clk.h) | |
843 | * | |
844 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
845 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
846 | * it is assumed that the clock will take on the rate of it's parent. | |
847 | * | |
848 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
849 | * if necessary. | |
850 | * | |
851 | * Caller must hold prepare_lock. | |
852 | */ | |
853 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
854 | { | |
855 | unsigned long old_rate; | |
856 | unsigned long parent_rate = 0; | |
b2476490 MT |
857 | struct clk *child; |
858 | ||
859 | old_rate = clk->rate; | |
860 | ||
861 | if (clk->parent) | |
862 | parent_rate = clk->parent->rate; | |
863 | ||
864 | if (clk->ops->recalc_rate) | |
865 | clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
866 | else | |
867 | clk->rate = parent_rate; | |
868 | ||
869 | /* | |
870 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
871 | * & ABORT_RATE_CHANGE notifiers | |
872 | */ | |
873 | if (clk->notifier_count && msg) | |
874 | __clk_notify(clk, msg, old_rate, clk->rate); | |
875 | ||
b67bfe0d | 876 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
877 | __clk_recalc_rates(child, msg); |
878 | } | |
879 | ||
a093bde2 UH |
880 | /** |
881 | * clk_get_rate - return the rate of clk | |
882 | * @clk: the clk whose rate is being returned | |
883 | * | |
884 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
885 | * is set, which means a recalc_rate will be issued. | |
886 | * If clk is NULL then returns 0. | |
887 | */ | |
888 | unsigned long clk_get_rate(struct clk *clk) | |
889 | { | |
890 | unsigned long rate; | |
891 | ||
892 | mutex_lock(&prepare_lock); | |
893 | ||
894 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
895 | __clk_recalc_rates(clk, 0); | |
896 | ||
897 | rate = __clk_get_rate(clk); | |
898 | mutex_unlock(&prepare_lock); | |
899 | ||
900 | return rate; | |
901 | } | |
902 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
903 | ||
b2476490 MT |
904 | /** |
905 | * __clk_speculate_rates | |
906 | * @clk: first clk in the subtree | |
907 | * @parent_rate: the "future" rate of clk's parent | |
908 | * | |
909 | * Walks the subtree of clks starting with clk, speculating rates as it | |
910 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
911 | * | |
912 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
913 | * pre-rate change notifications and returns early if no clks in the | |
914 | * subtree have subscribed to the notifications. Note that if a clk does not | |
915 | * implement the .recalc_rate callback then it is assumed that the clock will | |
916 | * take on the rate of it's parent. | |
917 | * | |
918 | * Caller must hold prepare_lock. | |
919 | */ | |
920 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
921 | { | |
b2476490 MT |
922 | struct clk *child; |
923 | unsigned long new_rate; | |
924 | int ret = NOTIFY_DONE; | |
925 | ||
926 | if (clk->ops->recalc_rate) | |
927 | new_rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
928 | else | |
929 | new_rate = parent_rate; | |
930 | ||
931 | /* abort the rate change if a driver returns NOTIFY_BAD */ | |
932 | if (clk->notifier_count) | |
933 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
934 | ||
935 | if (ret == NOTIFY_BAD) | |
936 | goto out; | |
937 | ||
b67bfe0d | 938 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
939 | ret = __clk_speculate_rates(child, new_rate); |
940 | if (ret == NOTIFY_BAD) | |
941 | break; | |
942 | } | |
943 | ||
944 | out: | |
945 | return ret; | |
946 | } | |
947 | ||
948 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate) | |
949 | { | |
950 | struct clk *child; | |
b2476490 MT |
951 | |
952 | clk->new_rate = new_rate; | |
953 | ||
b67bfe0d | 954 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
955 | if (child->ops->recalc_rate) |
956 | child->new_rate = child->ops->recalc_rate(child->hw, new_rate); | |
957 | else | |
958 | child->new_rate = new_rate; | |
959 | clk_calc_subtree(child, child->new_rate); | |
960 | } | |
961 | } | |
962 | ||
963 | /* | |
964 | * calculate the new rates returning the topmost clock that has to be | |
965 | * changed. | |
966 | */ | |
967 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
968 | { | |
969 | struct clk *top = clk; | |
81536e07 | 970 | unsigned long best_parent_rate = 0; |
b2476490 MT |
971 | unsigned long new_rate; |
972 | ||
7452b219 MT |
973 | /* sanity */ |
974 | if (IS_ERR_OR_NULL(clk)) | |
975 | return NULL; | |
976 | ||
63f5c3b2 MT |
977 | /* save parent rate, if it exists */ |
978 | if (clk->parent) | |
979 | best_parent_rate = clk->parent->rate; | |
980 | ||
7452b219 MT |
981 | /* never propagate up to the parent */ |
982 | if (!(clk->flags & CLK_SET_RATE_PARENT)) { | |
983 | if (!clk->ops->round_rate) { | |
984 | clk->new_rate = clk->rate; | |
985 | return NULL; | |
7452b219 | 986 | } |
63f5c3b2 MT |
987 | new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); |
988 | goto out; | |
7452b219 MT |
989 | } |
990 | ||
991 | /* need clk->parent from here on out */ | |
992 | if (!clk->parent) { | |
993 | pr_debug("%s: %s has NULL parent\n", __func__, clk->name); | |
b2476490 MT |
994 | return NULL; |
995 | } | |
996 | ||
7452b219 | 997 | if (!clk->ops->round_rate) { |
b2476490 | 998 | top = clk_calc_new_rates(clk->parent, rate); |
1b2f9903 | 999 | new_rate = clk->parent->new_rate; |
b2476490 MT |
1000 | |
1001 | goto out; | |
1002 | } | |
1003 | ||
7452b219 | 1004 | new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); |
b2476490 MT |
1005 | |
1006 | if (best_parent_rate != clk->parent->rate) { | |
1007 | top = clk_calc_new_rates(clk->parent, best_parent_rate); | |
1008 | ||
1009 | goto out; | |
1010 | } | |
1011 | ||
1012 | out: | |
1013 | clk_calc_subtree(clk, new_rate); | |
1014 | ||
1015 | return top; | |
1016 | } | |
1017 | ||
1018 | /* | |
1019 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
1020 | * so that in case of an error we can walk down the whole tree again and | |
1021 | * abort the change. | |
1022 | */ | |
1023 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
1024 | { | |
b2476490 MT |
1025 | struct clk *child, *fail_clk = NULL; |
1026 | int ret = NOTIFY_DONE; | |
1027 | ||
1028 | if (clk->rate == clk->new_rate) | |
5fda6858 | 1029 | return NULL; |
b2476490 MT |
1030 | |
1031 | if (clk->notifier_count) { | |
1032 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
1033 | if (ret == NOTIFY_BAD) | |
1034 | fail_clk = clk; | |
1035 | } | |
1036 | ||
b67bfe0d | 1037 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
1038 | clk = clk_propagate_rate_change(child, event); |
1039 | if (clk) | |
1040 | fail_clk = clk; | |
1041 | } | |
1042 | ||
1043 | return fail_clk; | |
1044 | } | |
1045 | ||
1046 | /* | |
1047 | * walk down a subtree and set the new rates notifying the rate | |
1048 | * change on the way | |
1049 | */ | |
1050 | static void clk_change_rate(struct clk *clk) | |
1051 | { | |
1052 | struct clk *child; | |
1053 | unsigned long old_rate; | |
bf47b4fd | 1054 | unsigned long best_parent_rate = 0; |
b2476490 MT |
1055 | |
1056 | old_rate = clk->rate; | |
1057 | ||
bf47b4fd PM |
1058 | if (clk->parent) |
1059 | best_parent_rate = clk->parent->rate; | |
1060 | ||
b2476490 | 1061 | if (clk->ops->set_rate) |
bf47b4fd | 1062 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 MT |
1063 | |
1064 | if (clk->ops->recalc_rate) | |
bf47b4fd | 1065 | clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate); |
b2476490 | 1066 | else |
bf47b4fd | 1067 | clk->rate = best_parent_rate; |
b2476490 MT |
1068 | |
1069 | if (clk->notifier_count && old_rate != clk->rate) | |
1070 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
1071 | ||
b67bfe0d | 1072 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
1073 | clk_change_rate(child); |
1074 | } | |
1075 | ||
1076 | /** | |
1077 | * clk_set_rate - specify a new rate for clk | |
1078 | * @clk: the clk whose rate is being changed | |
1079 | * @rate: the new rate for clk | |
1080 | * | |
5654dc94 | 1081 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 1082 | * |
5654dc94 MT |
1083 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
1084 | * propagate up to clk's parent; whether or not this happens depends on the | |
1085 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
1086 | * after calling .round_rate then upstream parent propagation is ignored. If | |
1087 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
1088 | * up to clk's parent and set it's rate. Upward propagation will continue | |
1089 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or | |
1090 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 1091 | * |
5654dc94 MT |
1092 | * Rate changes are accomplished via tree traversal that also recalculates the |
1093 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
1094 | * |
1095 | * Returns 0 on success, -EERROR otherwise. | |
1096 | */ | |
1097 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
1098 | { | |
1099 | struct clk *top, *fail_clk; | |
1100 | int ret = 0; | |
1101 | ||
1102 | /* prevent racing with updates to the clock topology */ | |
1103 | mutex_lock(&prepare_lock); | |
1104 | ||
1105 | /* bail early if nothing to do */ | |
1106 | if (rate == clk->rate) | |
1107 | goto out; | |
1108 | ||
7e0fa1b5 | 1109 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
1110 | ret = -EBUSY; |
1111 | goto out; | |
1112 | } | |
1113 | ||
b2476490 MT |
1114 | /* calculate new rates and get the topmost changed clock */ |
1115 | top = clk_calc_new_rates(clk, rate); | |
1116 | if (!top) { | |
1117 | ret = -EINVAL; | |
1118 | goto out; | |
1119 | } | |
1120 | ||
1121 | /* notify that we are about to change rates */ | |
1122 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
1123 | if (fail_clk) { | |
1124 | pr_warn("%s: failed to set %s rate\n", __func__, | |
1125 | fail_clk->name); | |
1126 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
1127 | ret = -EBUSY; | |
1128 | goto out; | |
1129 | } | |
1130 | ||
1131 | /* change the rates */ | |
1132 | clk_change_rate(top); | |
1133 | ||
b2476490 MT |
1134 | out: |
1135 | mutex_unlock(&prepare_lock); | |
1136 | ||
1137 | return ret; | |
1138 | } | |
1139 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
1140 | ||
1141 | /** | |
1142 | * clk_get_parent - return the parent of a clk | |
1143 | * @clk: the clk whose parent gets returned | |
1144 | * | |
1145 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
1146 | */ | |
1147 | struct clk *clk_get_parent(struct clk *clk) | |
1148 | { | |
1149 | struct clk *parent; | |
1150 | ||
1151 | mutex_lock(&prepare_lock); | |
1152 | parent = __clk_get_parent(clk); | |
1153 | mutex_unlock(&prepare_lock); | |
1154 | ||
1155 | return parent; | |
1156 | } | |
1157 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
1158 | ||
1159 | /* | |
1160 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
1161 | * optional for single-parent clocks. Always call .get_parent if it is | |
1162 | * available and WARN if it is missing for multi-parent clocks. | |
1163 | * | |
1164 | * For single-parent clocks without .get_parent, first check to see if the | |
1165 | * .parents array exists, and if so use it to avoid an expensive tree | |
1166 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
1167 | */ | |
1168 | static struct clk *__clk_init_parent(struct clk *clk) | |
1169 | { | |
1170 | struct clk *ret = NULL; | |
1171 | u8 index; | |
1172 | ||
1173 | /* handle the trivial cases */ | |
1174 | ||
1175 | if (!clk->num_parents) | |
1176 | goto out; | |
1177 | ||
1178 | if (clk->num_parents == 1) { | |
1179 | if (IS_ERR_OR_NULL(clk->parent)) | |
1180 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); | |
1181 | ret = clk->parent; | |
1182 | goto out; | |
1183 | } | |
1184 | ||
1185 | if (!clk->ops->get_parent) { | |
1186 | WARN(!clk->ops->get_parent, | |
1187 | "%s: multi-parent clocks must implement .get_parent\n", | |
1188 | __func__); | |
1189 | goto out; | |
1190 | }; | |
1191 | ||
1192 | /* | |
1193 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1194 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1195 | * clk->parent here; that is done by the calling function | |
1196 | */ | |
1197 | ||
1198 | index = clk->ops->get_parent(clk->hw); | |
1199 | ||
1200 | if (!clk->parents) | |
1201 | clk->parents = | |
7975059d | 1202 | kzalloc((sizeof(struct clk*) * clk->num_parents), |
b2476490 MT |
1203 | GFP_KERNEL); |
1204 | ||
1205 | if (!clk->parents) | |
1206 | ret = __clk_lookup(clk->parent_names[index]); | |
1207 | else if (!clk->parents[index]) | |
1208 | ret = clk->parents[index] = | |
1209 | __clk_lookup(clk->parent_names[index]); | |
1210 | else | |
1211 | ret = clk->parents[index]; | |
1212 | ||
1213 | out: | |
1214 | return ret; | |
1215 | } | |
1216 | ||
1217 | void __clk_reparent(struct clk *clk, struct clk *new_parent) | |
1218 | { | |
1219 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
1220 | struct dentry *d; | |
1221 | struct dentry *new_parent_d; | |
1222 | #endif | |
1223 | ||
1224 | if (!clk || !new_parent) | |
1225 | return; | |
1226 | ||
1227 | hlist_del(&clk->child_node); | |
1228 | ||
1229 | if (new_parent) | |
1230 | hlist_add_head(&clk->child_node, &new_parent->children); | |
1231 | else | |
1232 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1233 | ||
1234 | #ifdef CONFIG_COMMON_CLK_DEBUG | |
1235 | if (!inited) | |
1236 | goto out; | |
1237 | ||
1238 | if (new_parent) | |
1239 | new_parent_d = new_parent->dentry; | |
1240 | else | |
1241 | new_parent_d = orphandir; | |
1242 | ||
1243 | d = debugfs_rename(clk->dentry->d_parent, clk->dentry, | |
1244 | new_parent_d, clk->name); | |
1245 | if (d) | |
1246 | clk->dentry = d; | |
1247 | else | |
1248 | pr_debug("%s: failed to rename debugfs entry for %s\n", | |
1249 | __func__, clk->name); | |
1250 | out: | |
1251 | #endif | |
1252 | ||
1253 | clk->parent = new_parent; | |
1254 | ||
1255 | __clk_recalc_rates(clk, POST_RATE_CHANGE); | |
1256 | } | |
1257 | ||
1258 | static int __clk_set_parent(struct clk *clk, struct clk *parent) | |
1259 | { | |
1260 | struct clk *old_parent; | |
1261 | unsigned long flags; | |
1262 | int ret = -EINVAL; | |
1263 | u8 i; | |
1264 | ||
1265 | old_parent = clk->parent; | |
1266 | ||
863b1327 | 1267 | if (!clk->parents) |
7975059d RN |
1268 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), |
1269 | GFP_KERNEL); | |
b2476490 MT |
1270 | |
1271 | /* | |
863b1327 RN |
1272 | * find index of new parent clock using cached parent ptrs, |
1273 | * or if not yet cached, use string name comparison and cache | |
1274 | * them now to avoid future calls to __clk_lookup. | |
b2476490 | 1275 | */ |
863b1327 RN |
1276 | for (i = 0; i < clk->num_parents; i++) { |
1277 | if (clk->parents && clk->parents[i] == parent) | |
1278 | break; | |
1279 | else if (!strcmp(clk->parent_names[i], parent->name)) { | |
1280 | if (clk->parents) | |
1281 | clk->parents[i] = __clk_lookup(parent->name); | |
1282 | break; | |
1283 | } | |
1284 | } | |
b2476490 MT |
1285 | |
1286 | if (i == clk->num_parents) { | |
1287 | pr_debug("%s: clock %s is not a possible parent of clock %s\n", | |
1288 | __func__, parent->name, clk->name); | |
1289 | goto out; | |
1290 | } | |
1291 | ||
1292 | /* migrate prepare and enable */ | |
1293 | if (clk->prepare_count) | |
1294 | __clk_prepare(parent); | |
1295 | ||
1296 | /* FIXME replace with clk_is_enabled(clk) someday */ | |
1297 | spin_lock_irqsave(&enable_lock, flags); | |
1298 | if (clk->enable_count) | |
1299 | __clk_enable(parent); | |
1300 | spin_unlock_irqrestore(&enable_lock, flags); | |
1301 | ||
1302 | /* change clock input source */ | |
1303 | ret = clk->ops->set_parent(clk->hw, i); | |
1304 | ||
1305 | /* clean up old prepare and enable */ | |
1306 | spin_lock_irqsave(&enable_lock, flags); | |
1307 | if (clk->enable_count) | |
1308 | __clk_disable(old_parent); | |
1309 | spin_unlock_irqrestore(&enable_lock, flags); | |
1310 | ||
1311 | if (clk->prepare_count) | |
1312 | __clk_unprepare(old_parent); | |
1313 | ||
1314 | out: | |
1315 | return ret; | |
1316 | } | |
1317 | ||
1318 | /** | |
1319 | * clk_set_parent - switch the parent of a mux clk | |
1320 | * @clk: the mux clk whose input we are switching | |
1321 | * @parent: the new input to clk | |
1322 | * | |
1323 | * Re-parent clk to use parent as it's new input source. If clk has the | |
1324 | * CLK_SET_PARENT_GATE flag set then clk must be gated for this | |
1325 | * operation to succeed. After successfully changing clk's parent | |
1326 | * clk_set_parent will update the clk topology, sysfs topology and | |
1327 | * propagate rate recalculation via __clk_recalc_rates. Returns 0 on | |
1328 | * success, -EERROR otherwise. | |
1329 | */ | |
1330 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
1331 | { | |
1332 | int ret = 0; | |
1333 | ||
1334 | if (!clk || !clk->ops) | |
1335 | return -EINVAL; | |
1336 | ||
1337 | if (!clk->ops->set_parent) | |
1338 | return -ENOSYS; | |
1339 | ||
1340 | /* prevent racing with updates to the clock topology */ | |
1341 | mutex_lock(&prepare_lock); | |
1342 | ||
1343 | if (clk->parent == parent) | |
1344 | goto out; | |
1345 | ||
1346 | /* propagate PRE_RATE_CHANGE notifications */ | |
1347 | if (clk->notifier_count) | |
1348 | ret = __clk_speculate_rates(clk, parent->rate); | |
1349 | ||
1350 | /* abort if a driver objects */ | |
1351 | if (ret == NOTIFY_STOP) | |
1352 | goto out; | |
1353 | ||
1354 | /* only re-parent if the clock is not in use */ | |
1355 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) | |
1356 | ret = -EBUSY; | |
1357 | else | |
1358 | ret = __clk_set_parent(clk, parent); | |
1359 | ||
1360 | /* propagate ABORT_RATE_CHANGE if .set_parent failed */ | |
1361 | if (ret) { | |
1362 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); | |
1363 | goto out; | |
1364 | } | |
1365 | ||
1366 | /* propagate rate recalculation downstream */ | |
1367 | __clk_reparent(clk, parent); | |
1368 | ||
1369 | out: | |
1370 | mutex_unlock(&prepare_lock); | |
1371 | ||
1372 | return ret; | |
1373 | } | |
1374 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1375 | ||
1376 | /** | |
1377 | * __clk_init - initialize the data structures in a struct clk | |
1378 | * @dev: device initializing this clk, placeholder for now | |
1379 | * @clk: clk being initialized | |
1380 | * | |
1381 | * Initializes the lists in struct clk, queries the hardware for the | |
1382 | * parent and rate and sets them both. | |
b2476490 | 1383 | */ |
d1302a36 | 1384 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1385 | { |
d1302a36 | 1386 | int i, ret = 0; |
b2476490 | 1387 | struct clk *orphan; |
b67bfe0d | 1388 | struct hlist_node *tmp2; |
b2476490 MT |
1389 | |
1390 | if (!clk) | |
d1302a36 | 1391 | return -EINVAL; |
b2476490 MT |
1392 | |
1393 | mutex_lock(&prepare_lock); | |
1394 | ||
1395 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1396 | if (__clk_lookup(clk->name)) { |
1397 | pr_debug("%s: clk %s already initialized\n", | |
1398 | __func__, clk->name); | |
1399 | ret = -EEXIST; | |
b2476490 | 1400 | goto out; |
d1302a36 | 1401 | } |
b2476490 | 1402 | |
d4d7e3dd MT |
1403 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1404 | if (clk->ops->set_rate && | |
1405 | !(clk->ops->round_rate && clk->ops->recalc_rate)) { | |
1406 | pr_warning("%s: %s must implement .round_rate & .recalc_rate\n", | |
1407 | __func__, clk->name); | |
d1302a36 | 1408 | ret = -EINVAL; |
d4d7e3dd MT |
1409 | goto out; |
1410 | } | |
1411 | ||
1412 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1413 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1414 | __func__, clk->name); | |
d1302a36 | 1415 | ret = -EINVAL; |
d4d7e3dd MT |
1416 | goto out; |
1417 | } | |
1418 | ||
b2476490 MT |
1419 | /* throw a WARN if any entries in parent_names are NULL */ |
1420 | for (i = 0; i < clk->num_parents; i++) | |
1421 | WARN(!clk->parent_names[i], | |
1422 | "%s: invalid NULL in %s's .parent_names\n", | |
1423 | __func__, clk->name); | |
1424 | ||
1425 | /* | |
1426 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1427 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1428 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1429 | * must always check for a NULL pointer and try to populate it if | |
1430 | * necessary. | |
1431 | * | |
1432 | * If clk->parents is not NULL we skip this entire block. This allows | |
1433 | * for clock drivers to statically initialize clk->parents. | |
1434 | */ | |
9ca1c5a4 RN |
1435 | if (clk->num_parents > 1 && !clk->parents) { |
1436 | clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), | |
b2476490 MT |
1437 | GFP_KERNEL); |
1438 | /* | |
1439 | * __clk_lookup returns NULL for parents that have not been | |
1440 | * clk_init'd; thus any access to clk->parents[] must check | |
1441 | * for a NULL pointer. We can always perform lazy lookups for | |
1442 | * missing parents later on. | |
1443 | */ | |
1444 | if (clk->parents) | |
1445 | for (i = 0; i < clk->num_parents; i++) | |
1446 | clk->parents[i] = | |
1447 | __clk_lookup(clk->parent_names[i]); | |
1448 | } | |
1449 | ||
1450 | clk->parent = __clk_init_parent(clk); | |
1451 | ||
1452 | /* | |
1453 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1454 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1455 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1456 | * clk list. | |
1457 | * | |
1458 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1459 | * clocks and re-parent any that are children of the clock currently | |
1460 | * being clk_init'd. | |
1461 | */ | |
1462 | if (clk->parent) | |
1463 | hlist_add_head(&clk->child_node, | |
1464 | &clk->parent->children); | |
1465 | else if (clk->flags & CLK_IS_ROOT) | |
1466 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1467 | else | |
1468 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1469 | ||
1470 | /* | |
1471 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1472 | * simple clocks and lazy developers the default fallback is to use the | |
1473 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1474 | * then rate is set to zero. | |
1475 | */ | |
1476 | if (clk->ops->recalc_rate) | |
1477 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1478 | __clk_get_rate(clk->parent)); | |
1479 | else if (clk->parent) | |
1480 | clk->rate = clk->parent->rate; | |
1481 | else | |
1482 | clk->rate = 0; | |
1483 | ||
1484 | /* | |
1485 | * walk the list of orphan clocks and reparent any that are children of | |
1486 | * this clock | |
1487 | */ | |
b67bfe0d | 1488 | hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { |
1f61e5f1 MF |
1489 | if (orphan->ops->get_parent) { |
1490 | i = orphan->ops->get_parent(orphan->hw); | |
1491 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1492 | __clk_reparent(orphan, clk); | |
1493 | continue; | |
1494 | } | |
1495 | ||
b2476490 MT |
1496 | for (i = 0; i < orphan->num_parents; i++) |
1497 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1498 | __clk_reparent(orphan, clk); | |
1499 | break; | |
1500 | } | |
1f61e5f1 | 1501 | } |
b2476490 MT |
1502 | |
1503 | /* | |
1504 | * optional platform-specific magic | |
1505 | * | |
1506 | * The .init callback is not used by any of the basic clock types, but | |
1507 | * exists for weird hardware that must perform initialization magic. | |
1508 | * Please consider other ways of solving initialization problems before | |
1509 | * using this callback, as it's use is discouraged. | |
1510 | */ | |
1511 | if (clk->ops->init) | |
1512 | clk->ops->init(clk->hw); | |
1513 | ||
1514 | clk_debug_register(clk); | |
1515 | ||
1516 | out: | |
1517 | mutex_unlock(&prepare_lock); | |
1518 | ||
d1302a36 | 1519 | return ret; |
b2476490 MT |
1520 | } |
1521 | ||
0197b3ea SK |
1522 | /** |
1523 | * __clk_register - register a clock and return a cookie. | |
1524 | * | |
1525 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1526 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1527 | * of the struct clk need to be initialized. | |
1528 | * | |
1529 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1530 | * data. | |
1531 | * | |
1532 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1533 | * very large numbers of clocks that need to be statically initialized. It is | |
1534 | * a layering violation to include clk-private.h from any code which implements | |
1535 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
1536 | * separate C file from the logic that implements it's operations. Returns 0 | |
1537 | * on success, otherwise an error code. | |
1538 | */ | |
1539 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
1540 | { | |
1541 | int ret; | |
1542 | struct clk *clk; | |
1543 | ||
1544 | clk = hw->clk; | |
1545 | clk->name = hw->init->name; | |
1546 | clk->ops = hw->init->ops; | |
1547 | clk->hw = hw; | |
1548 | clk->flags = hw->init->flags; | |
1549 | clk->parent_names = hw->init->parent_names; | |
1550 | clk->num_parents = hw->init->num_parents; | |
1551 | ||
1552 | ret = __clk_init(dev, clk); | |
1553 | if (ret) | |
1554 | return ERR_PTR(ret); | |
1555 | ||
1556 | return clk; | |
1557 | } | |
1558 | EXPORT_SYMBOL_GPL(__clk_register); | |
1559 | ||
46c8773a | 1560 | static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk) |
b2476490 | 1561 | { |
d1302a36 | 1562 | int i, ret; |
b2476490 | 1563 | |
0197b3ea SK |
1564 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
1565 | if (!clk->name) { | |
1566 | pr_err("%s: could not allocate clk->name\n", __func__); | |
1567 | ret = -ENOMEM; | |
1568 | goto fail_name; | |
1569 | } | |
1570 | clk->ops = hw->init->ops; | |
b2476490 | 1571 | clk->hw = hw; |
0197b3ea SK |
1572 | clk->flags = hw->init->flags; |
1573 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
1574 | hw->clk = clk; |
1575 | ||
d1302a36 | 1576 | /* allocate local copy in case parent_names is __initdata */ |
0197b3ea | 1577 | clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents), |
d1302a36 MT |
1578 | GFP_KERNEL); |
1579 | ||
1580 | if (!clk->parent_names) { | |
1581 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
1582 | ret = -ENOMEM; | |
1583 | goto fail_parent_names; | |
1584 | } | |
1585 | ||
1586 | ||
1587 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea SK |
1588 | for (i = 0; i < clk->num_parents; i++) { |
1589 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], | |
1590 | GFP_KERNEL); | |
d1302a36 MT |
1591 | if (!clk->parent_names[i]) { |
1592 | pr_err("%s: could not copy parent_names\n", __func__); | |
1593 | ret = -ENOMEM; | |
1594 | goto fail_parent_names_copy; | |
1595 | } | |
1596 | } | |
1597 | ||
1598 | ret = __clk_init(dev, clk); | |
1599 | if (!ret) | |
46c8773a | 1600 | return 0; |
b2476490 | 1601 | |
d1302a36 MT |
1602 | fail_parent_names_copy: |
1603 | while (--i >= 0) | |
1604 | kfree(clk->parent_names[i]); | |
1605 | kfree(clk->parent_names); | |
1606 | fail_parent_names: | |
0197b3ea SK |
1607 | kfree(clk->name); |
1608 | fail_name: | |
46c8773a SB |
1609 | return ret; |
1610 | } | |
1611 | ||
1612 | /** | |
1613 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
1614 | * @dev: device that is registering this clock | |
1615 | * @hw: link to hardware-specific clock data | |
1616 | * | |
1617 | * clk_register is the primary interface for populating the clock tree with new | |
1618 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
1619 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
1620 | * rest of the clock API. In the event of an error clk_register will return an | |
1621 | * error code; drivers must test for an error code after calling clk_register. | |
1622 | */ | |
1623 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
1624 | { | |
1625 | int ret; | |
1626 | struct clk *clk; | |
1627 | ||
1628 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
1629 | if (!clk) { | |
1630 | pr_err("%s: could not allocate clk\n", __func__); | |
1631 | ret = -ENOMEM; | |
1632 | goto fail_out; | |
1633 | } | |
1634 | ||
1635 | ret = _clk_register(dev, hw, clk); | |
1636 | if (!ret) | |
1637 | return clk; | |
1638 | ||
d1302a36 MT |
1639 | kfree(clk); |
1640 | fail_out: | |
1641 | return ERR_PTR(ret); | |
b2476490 MT |
1642 | } |
1643 | EXPORT_SYMBOL_GPL(clk_register); | |
1644 | ||
1df5c939 MB |
1645 | /** |
1646 | * clk_unregister - unregister a currently registered clock | |
1647 | * @clk: clock to unregister | |
1648 | * | |
1649 | * Currently unimplemented. | |
1650 | */ | |
1651 | void clk_unregister(struct clk *clk) {} | |
1652 | EXPORT_SYMBOL_GPL(clk_unregister); | |
1653 | ||
46c8773a SB |
1654 | static void devm_clk_release(struct device *dev, void *res) |
1655 | { | |
1656 | clk_unregister(res); | |
1657 | } | |
1658 | ||
1659 | /** | |
1660 | * devm_clk_register - resource managed clk_register() | |
1661 | * @dev: device that is registering this clock | |
1662 | * @hw: link to hardware-specific clock data | |
1663 | * | |
1664 | * Managed clk_register(). Clocks returned from this function are | |
1665 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
1666 | * more information. | |
1667 | */ | |
1668 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
1669 | { | |
1670 | struct clk *clk; | |
1671 | int ret; | |
1672 | ||
1673 | clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL); | |
1674 | if (!clk) | |
1675 | return ERR_PTR(-ENOMEM); | |
1676 | ||
1677 | ret = _clk_register(dev, hw, clk); | |
1678 | if (!ret) { | |
1679 | devres_add(dev, clk); | |
1680 | } else { | |
1681 | devres_free(clk); | |
1682 | clk = ERR_PTR(ret); | |
1683 | } | |
1684 | ||
1685 | return clk; | |
1686 | } | |
1687 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
1688 | ||
1689 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
1690 | { | |
1691 | struct clk *c = res; | |
1692 | if (WARN_ON(!c)) | |
1693 | return 0; | |
1694 | return c == data; | |
1695 | } | |
1696 | ||
1697 | /** | |
1698 | * devm_clk_unregister - resource managed clk_unregister() | |
1699 | * @clk: clock to unregister | |
1700 | * | |
1701 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
1702 | * this function will not need to be called and the resource management | |
1703 | * code will ensure that the resource is freed. | |
1704 | */ | |
1705 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
1706 | { | |
1707 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
1708 | } | |
1709 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
1710 | ||
b2476490 MT |
1711 | /*** clk rate change notifiers ***/ |
1712 | ||
1713 | /** | |
1714 | * clk_notifier_register - add a clk rate change notifier | |
1715 | * @clk: struct clk * to watch | |
1716 | * @nb: struct notifier_block * with callback info | |
1717 | * | |
1718 | * Request notification when clk's rate changes. This uses an SRCU | |
1719 | * notifier because we want it to block and notifier unregistrations are | |
1720 | * uncommon. The callbacks associated with the notifier must not | |
1721 | * re-enter into the clk framework by calling any top-level clk APIs; | |
1722 | * this will cause a nested prepare_lock mutex. | |
1723 | * | |
1724 | * Pre-change notifier callbacks will be passed the current, pre-change | |
1725 | * rate of the clk via struct clk_notifier_data.old_rate. The new, | |
1726 | * post-change rate of the clk is passed via struct | |
1727 | * clk_notifier_data.new_rate. | |
1728 | * | |
1729 | * Post-change notifiers will pass the now-current, post-change rate of | |
1730 | * the clk in both struct clk_notifier_data.old_rate and struct | |
1731 | * clk_notifier_data.new_rate. | |
1732 | * | |
1733 | * Abort-change notifiers are effectively the opposite of pre-change | |
1734 | * notifiers: the original pre-change clk rate is passed in via struct | |
1735 | * clk_notifier_data.new_rate and the failed post-change rate is passed | |
1736 | * in via struct clk_notifier_data.old_rate. | |
1737 | * | |
1738 | * clk_notifier_register() must be called from non-atomic context. | |
1739 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
1740 | * allocation failure; otherwise, passes along the return value of | |
1741 | * srcu_notifier_chain_register(). | |
1742 | */ | |
1743 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
1744 | { | |
1745 | struct clk_notifier *cn; | |
1746 | int ret = -ENOMEM; | |
1747 | ||
1748 | if (!clk || !nb) | |
1749 | return -EINVAL; | |
1750 | ||
1751 | mutex_lock(&prepare_lock); | |
1752 | ||
1753 | /* search the list of notifiers for this clk */ | |
1754 | list_for_each_entry(cn, &clk_notifier_list, node) | |
1755 | if (cn->clk == clk) | |
1756 | break; | |
1757 | ||
1758 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
1759 | if (cn->clk != clk) { | |
1760 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
1761 | if (!cn) | |
1762 | goto out; | |
1763 | ||
1764 | cn->clk = clk; | |
1765 | srcu_init_notifier_head(&cn->notifier_head); | |
1766 | ||
1767 | list_add(&cn->node, &clk_notifier_list); | |
1768 | } | |
1769 | ||
1770 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
1771 | ||
1772 | clk->notifier_count++; | |
1773 | ||
1774 | out: | |
1775 | mutex_unlock(&prepare_lock); | |
1776 | ||
1777 | return ret; | |
1778 | } | |
1779 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
1780 | ||
1781 | /** | |
1782 | * clk_notifier_unregister - remove a clk rate change notifier | |
1783 | * @clk: struct clk * | |
1784 | * @nb: struct notifier_block * with callback info | |
1785 | * | |
1786 | * Request no further notification for changes to 'clk' and frees memory | |
1787 | * allocated in clk_notifier_register. | |
1788 | * | |
1789 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
1790 | * along the return value of srcu_notifier_chain_unregister(). | |
1791 | */ | |
1792 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
1793 | { | |
1794 | struct clk_notifier *cn = NULL; | |
1795 | int ret = -EINVAL; | |
1796 | ||
1797 | if (!clk || !nb) | |
1798 | return -EINVAL; | |
1799 | ||
1800 | mutex_lock(&prepare_lock); | |
1801 | ||
1802 | list_for_each_entry(cn, &clk_notifier_list, node) | |
1803 | if (cn->clk == clk) | |
1804 | break; | |
1805 | ||
1806 | if (cn->clk == clk) { | |
1807 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
1808 | ||
1809 | clk->notifier_count--; | |
1810 | ||
1811 | /* XXX the notifier code should handle this better */ | |
1812 | if (!cn->notifier_head.head) { | |
1813 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
1814 | kfree(cn); | |
1815 | } | |
1816 | ||
1817 | } else { | |
1818 | ret = -ENOENT; | |
1819 | } | |
1820 | ||
1821 | mutex_unlock(&prepare_lock); | |
1822 | ||
1823 | return ret; | |
1824 | } | |
1825 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
1826 | |
1827 | #ifdef CONFIG_OF | |
1828 | /** | |
1829 | * struct of_clk_provider - Clock provider registration structure | |
1830 | * @link: Entry in global list of clock providers | |
1831 | * @node: Pointer to device tree node of clock provider | |
1832 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
1833 | * given clock specifier | |
1834 | * @data: context pointer to be passed into @get callback | |
1835 | */ | |
1836 | struct of_clk_provider { | |
1837 | struct list_head link; | |
1838 | ||
1839 | struct device_node *node; | |
1840 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
1841 | void *data; | |
1842 | }; | |
1843 | ||
f2f6c255 PG |
1844 | extern struct of_device_id __clk_of_table[]; |
1845 | ||
1846 | static const struct of_device_id __clk_of_table_sentinel | |
1847 | __used __section(__clk_of_table_end); | |
1848 | ||
766e6a4e GL |
1849 | static LIST_HEAD(of_clk_providers); |
1850 | static DEFINE_MUTEX(of_clk_lock); | |
1851 | ||
1852 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
1853 | void *data) | |
1854 | { | |
1855 | return data; | |
1856 | } | |
1857 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
1858 | ||
494bfec9 SG |
1859 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
1860 | { | |
1861 | struct clk_onecell_data *clk_data = data; | |
1862 | unsigned int idx = clkspec->args[0]; | |
1863 | ||
1864 | if (idx >= clk_data->clk_num) { | |
1865 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
1866 | return ERR_PTR(-EINVAL); | |
1867 | } | |
1868 | ||
1869 | return clk_data->clks[idx]; | |
1870 | } | |
1871 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
1872 | ||
766e6a4e GL |
1873 | /** |
1874 | * of_clk_add_provider() - Register a clock provider for a node | |
1875 | * @np: Device node pointer associated with clock provider | |
1876 | * @clk_src_get: callback for decoding clock | |
1877 | * @data: context pointer for @clk_src_get callback. | |
1878 | */ | |
1879 | int of_clk_add_provider(struct device_node *np, | |
1880 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
1881 | void *data), | |
1882 | void *data) | |
1883 | { | |
1884 | struct of_clk_provider *cp; | |
1885 | ||
1886 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
1887 | if (!cp) | |
1888 | return -ENOMEM; | |
1889 | ||
1890 | cp->node = of_node_get(np); | |
1891 | cp->data = data; | |
1892 | cp->get = clk_src_get; | |
1893 | ||
1894 | mutex_lock(&of_clk_lock); | |
1895 | list_add(&cp->link, &of_clk_providers); | |
1896 | mutex_unlock(&of_clk_lock); | |
1897 | pr_debug("Added clock from %s\n", np->full_name); | |
1898 | ||
1899 | return 0; | |
1900 | } | |
1901 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
1902 | ||
1903 | /** | |
1904 | * of_clk_del_provider() - Remove a previously registered clock provider | |
1905 | * @np: Device node pointer associated with clock provider | |
1906 | */ | |
1907 | void of_clk_del_provider(struct device_node *np) | |
1908 | { | |
1909 | struct of_clk_provider *cp; | |
1910 | ||
1911 | mutex_lock(&of_clk_lock); | |
1912 | list_for_each_entry(cp, &of_clk_providers, link) { | |
1913 | if (cp->node == np) { | |
1914 | list_del(&cp->link); | |
1915 | of_node_put(cp->node); | |
1916 | kfree(cp); | |
1917 | break; | |
1918 | } | |
1919 | } | |
1920 | mutex_unlock(&of_clk_lock); | |
1921 | } | |
1922 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
1923 | ||
1924 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
1925 | { | |
1926 | struct of_clk_provider *provider; | |
1927 | struct clk *clk = ERR_PTR(-ENOENT); | |
1928 | ||
1929 | /* Check if we have such a provider in our array */ | |
1930 | mutex_lock(&of_clk_lock); | |
1931 | list_for_each_entry(provider, &of_clk_providers, link) { | |
1932 | if (provider->node == clkspec->np) | |
1933 | clk = provider->get(clkspec, provider->data); | |
1934 | if (!IS_ERR(clk)) | |
1935 | break; | |
1936 | } | |
1937 | mutex_unlock(&of_clk_lock); | |
1938 | ||
1939 | return clk; | |
1940 | } | |
1941 | ||
1942 | const char *of_clk_get_parent_name(struct device_node *np, int index) | |
1943 | { | |
1944 | struct of_phandle_args clkspec; | |
1945 | const char *clk_name; | |
1946 | int rc; | |
1947 | ||
1948 | if (index < 0) | |
1949 | return NULL; | |
1950 | ||
1951 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
1952 | &clkspec); | |
1953 | if (rc) | |
1954 | return NULL; | |
1955 | ||
1956 | if (of_property_read_string_index(clkspec.np, "clock-output-names", | |
1957 | clkspec.args_count ? clkspec.args[0] : 0, | |
1958 | &clk_name) < 0) | |
1959 | clk_name = clkspec.np->name; | |
1960 | ||
1961 | of_node_put(clkspec.np); | |
1962 | return clk_name; | |
1963 | } | |
1964 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
1965 | ||
1966 | /** | |
1967 | * of_clk_init() - Scan and init clock providers from the DT | |
1968 | * @matches: array of compatible values and init functions for providers. | |
1969 | * | |
1970 | * This function scans the device tree for matching clock providers and | |
1971 | * calls their initialization functions | |
1972 | */ | |
1973 | void __init of_clk_init(const struct of_device_id *matches) | |
1974 | { | |
1975 | struct device_node *np; | |
1976 | ||
f2f6c255 PG |
1977 | if (!matches) |
1978 | matches = __clk_of_table; | |
1979 | ||
766e6a4e GL |
1980 | for_each_matching_node(np, matches) { |
1981 | const struct of_device_id *match = of_match_node(matches, np); | |
1982 | of_clk_init_cb_t clk_init_cb = match->data; | |
1983 | clk_init_cb(np); | |
1984 | } | |
1985 | } | |
1986 | #endif |