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b2476490 MT |
1 | /* |
2 | * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com> | |
3 | * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * Standard functionality for the common clock API. See Documentation/clk.txt | |
10 | */ | |
11 | ||
12 | #include <linux/clk-private.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/mutex.h> | |
15 | #include <linux/spinlock.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/list.h> | |
18 | #include <linux/slab.h> | |
766e6a4e | 19 | #include <linux/of.h> |
46c8773a | 20 | #include <linux/device.h> |
f2f6c255 | 21 | #include <linux/init.h> |
533ddeb1 | 22 | #include <linux/sched.h> |
b2476490 | 23 | |
d6782c26 SN |
24 | #include "clk.h" |
25 | ||
b2476490 MT |
26 | static DEFINE_SPINLOCK(enable_lock); |
27 | static DEFINE_MUTEX(prepare_lock); | |
28 | ||
533ddeb1 MT |
29 | static struct task_struct *prepare_owner; |
30 | static struct task_struct *enable_owner; | |
31 | ||
32 | static int prepare_refcnt; | |
33 | static int enable_refcnt; | |
34 | ||
b2476490 MT |
35 | static HLIST_HEAD(clk_root_list); |
36 | static HLIST_HEAD(clk_orphan_list); | |
37 | static LIST_HEAD(clk_notifier_list); | |
38 | ||
eab89f69 MT |
39 | /*** locking ***/ |
40 | static void clk_prepare_lock(void) | |
41 | { | |
533ddeb1 MT |
42 | if (!mutex_trylock(&prepare_lock)) { |
43 | if (prepare_owner == current) { | |
44 | prepare_refcnt++; | |
45 | return; | |
46 | } | |
47 | mutex_lock(&prepare_lock); | |
48 | } | |
49 | WARN_ON_ONCE(prepare_owner != NULL); | |
50 | WARN_ON_ONCE(prepare_refcnt != 0); | |
51 | prepare_owner = current; | |
52 | prepare_refcnt = 1; | |
eab89f69 MT |
53 | } |
54 | ||
55 | static void clk_prepare_unlock(void) | |
56 | { | |
533ddeb1 MT |
57 | WARN_ON_ONCE(prepare_owner != current); |
58 | WARN_ON_ONCE(prepare_refcnt == 0); | |
59 | ||
60 | if (--prepare_refcnt) | |
61 | return; | |
62 | prepare_owner = NULL; | |
eab89f69 MT |
63 | mutex_unlock(&prepare_lock); |
64 | } | |
65 | ||
66 | static unsigned long clk_enable_lock(void) | |
67 | { | |
68 | unsigned long flags; | |
533ddeb1 MT |
69 | |
70 | if (!spin_trylock_irqsave(&enable_lock, flags)) { | |
71 | if (enable_owner == current) { | |
72 | enable_refcnt++; | |
73 | return flags; | |
74 | } | |
75 | spin_lock_irqsave(&enable_lock, flags); | |
76 | } | |
77 | WARN_ON_ONCE(enable_owner != NULL); | |
78 | WARN_ON_ONCE(enable_refcnt != 0); | |
79 | enable_owner = current; | |
80 | enable_refcnt = 1; | |
eab89f69 MT |
81 | return flags; |
82 | } | |
83 | ||
84 | static void clk_enable_unlock(unsigned long flags) | |
85 | { | |
533ddeb1 MT |
86 | WARN_ON_ONCE(enable_owner != current); |
87 | WARN_ON_ONCE(enable_refcnt == 0); | |
88 | ||
89 | if (--enable_refcnt) | |
90 | return; | |
91 | enable_owner = NULL; | |
eab89f69 MT |
92 | spin_unlock_irqrestore(&enable_lock, flags); |
93 | } | |
94 | ||
b2476490 MT |
95 | /*** debugfs support ***/ |
96 | ||
ea72dc2c | 97 | #ifdef CONFIG_DEBUG_FS |
b2476490 MT |
98 | #include <linux/debugfs.h> |
99 | ||
100 | static struct dentry *rootdir; | |
101 | static struct dentry *orphandir; | |
102 | static int inited = 0; | |
103 | ||
1af599df PG |
104 | static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level) |
105 | { | |
106 | if (!c) | |
107 | return; | |
108 | ||
5279fc40 | 109 | seq_printf(s, "%*s%-*s %-11d %-12d %-10lu %-11lu", |
1af599df PG |
110 | level * 3 + 1, "", |
111 | 30 - level * 3, c->name, | |
5279fc40 BB |
112 | c->enable_count, c->prepare_count, clk_get_rate(c), |
113 | clk_get_accuracy(c)); | |
1af599df PG |
114 | seq_printf(s, "\n"); |
115 | } | |
116 | ||
117 | static void clk_summary_show_subtree(struct seq_file *s, struct clk *c, | |
118 | int level) | |
119 | { | |
120 | struct clk *child; | |
1af599df PG |
121 | |
122 | if (!c) | |
123 | return; | |
124 | ||
125 | clk_summary_show_one(s, c, level); | |
126 | ||
b67bfe0d | 127 | hlist_for_each_entry(child, &c->children, child_node) |
1af599df PG |
128 | clk_summary_show_subtree(s, child, level + 1); |
129 | } | |
130 | ||
131 | static int clk_summary_show(struct seq_file *s, void *data) | |
132 | { | |
133 | struct clk *c; | |
1af599df | 134 | |
5279fc40 BB |
135 | seq_printf(s, " clock enable_cnt prepare_cnt rate accuracy\n"); |
136 | seq_printf(s, "---------------------------------------------------------------------------------\n"); | |
1af599df | 137 | |
eab89f69 | 138 | clk_prepare_lock(); |
1af599df | 139 | |
b67bfe0d | 140 | hlist_for_each_entry(c, &clk_root_list, child_node) |
1af599df PG |
141 | clk_summary_show_subtree(s, c, 0); |
142 | ||
b67bfe0d | 143 | hlist_for_each_entry(c, &clk_orphan_list, child_node) |
1af599df PG |
144 | clk_summary_show_subtree(s, c, 0); |
145 | ||
eab89f69 | 146 | clk_prepare_unlock(); |
1af599df PG |
147 | |
148 | return 0; | |
149 | } | |
150 | ||
151 | ||
152 | static int clk_summary_open(struct inode *inode, struct file *file) | |
153 | { | |
154 | return single_open(file, clk_summary_show, inode->i_private); | |
155 | } | |
156 | ||
157 | static const struct file_operations clk_summary_fops = { | |
158 | .open = clk_summary_open, | |
159 | .read = seq_read, | |
160 | .llseek = seq_lseek, | |
161 | .release = single_release, | |
162 | }; | |
163 | ||
bddca894 PG |
164 | static void clk_dump_one(struct seq_file *s, struct clk *c, int level) |
165 | { | |
166 | if (!c) | |
167 | return; | |
168 | ||
169 | seq_printf(s, "\"%s\": { ", c->name); | |
170 | seq_printf(s, "\"enable_count\": %d,", c->enable_count); | |
171 | seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); | |
670decdd | 172 | seq_printf(s, "\"rate\": %lu", clk_get_rate(c)); |
5279fc40 | 173 | seq_printf(s, "\"accuracy\": %lu", clk_get_accuracy(c)); |
bddca894 PG |
174 | } |
175 | ||
176 | static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) | |
177 | { | |
178 | struct clk *child; | |
bddca894 PG |
179 | |
180 | if (!c) | |
181 | return; | |
182 | ||
183 | clk_dump_one(s, c, level); | |
184 | ||
b67bfe0d | 185 | hlist_for_each_entry(child, &c->children, child_node) { |
bddca894 PG |
186 | seq_printf(s, ","); |
187 | clk_dump_subtree(s, child, level + 1); | |
188 | } | |
189 | ||
190 | seq_printf(s, "}"); | |
191 | } | |
192 | ||
193 | static int clk_dump(struct seq_file *s, void *data) | |
194 | { | |
195 | struct clk *c; | |
bddca894 PG |
196 | bool first_node = true; |
197 | ||
198 | seq_printf(s, "{"); | |
199 | ||
eab89f69 | 200 | clk_prepare_lock(); |
bddca894 | 201 | |
b67bfe0d | 202 | hlist_for_each_entry(c, &clk_root_list, child_node) { |
bddca894 PG |
203 | if (!first_node) |
204 | seq_printf(s, ","); | |
205 | first_node = false; | |
206 | clk_dump_subtree(s, c, 0); | |
207 | } | |
208 | ||
b67bfe0d | 209 | hlist_for_each_entry(c, &clk_orphan_list, child_node) { |
bddca894 PG |
210 | seq_printf(s, ","); |
211 | clk_dump_subtree(s, c, 0); | |
212 | } | |
213 | ||
eab89f69 | 214 | clk_prepare_unlock(); |
bddca894 PG |
215 | |
216 | seq_printf(s, "}"); | |
217 | return 0; | |
218 | } | |
219 | ||
220 | ||
221 | static int clk_dump_open(struct inode *inode, struct file *file) | |
222 | { | |
223 | return single_open(file, clk_dump, inode->i_private); | |
224 | } | |
225 | ||
226 | static const struct file_operations clk_dump_fops = { | |
227 | .open = clk_dump_open, | |
228 | .read = seq_read, | |
229 | .llseek = seq_lseek, | |
230 | .release = single_release, | |
231 | }; | |
232 | ||
b2476490 MT |
233 | /* caller must hold prepare_lock */ |
234 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) | |
235 | { | |
236 | struct dentry *d; | |
237 | int ret = -ENOMEM; | |
238 | ||
239 | if (!clk || !pdentry) { | |
240 | ret = -EINVAL; | |
241 | goto out; | |
242 | } | |
243 | ||
244 | d = debugfs_create_dir(clk->name, pdentry); | |
245 | if (!d) | |
246 | goto out; | |
247 | ||
248 | clk->dentry = d; | |
249 | ||
250 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, | |
251 | (u32 *)&clk->rate); | |
252 | if (!d) | |
253 | goto err_out; | |
254 | ||
5279fc40 BB |
255 | d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry, |
256 | (u32 *)&clk->accuracy); | |
257 | if (!d) | |
258 | goto err_out; | |
259 | ||
b2476490 MT |
260 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, |
261 | (u32 *)&clk->flags); | |
262 | if (!d) | |
263 | goto err_out; | |
264 | ||
265 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, | |
266 | (u32 *)&clk->prepare_count); | |
267 | if (!d) | |
268 | goto err_out; | |
269 | ||
270 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, | |
271 | (u32 *)&clk->enable_count); | |
272 | if (!d) | |
273 | goto err_out; | |
274 | ||
275 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, | |
276 | (u32 *)&clk->notifier_count); | |
277 | if (!d) | |
278 | goto err_out; | |
279 | ||
280 | ret = 0; | |
281 | goto out; | |
282 | ||
283 | err_out: | |
b5f98e65 AE |
284 | debugfs_remove_recursive(clk->dentry); |
285 | clk->dentry = NULL; | |
b2476490 MT |
286 | out: |
287 | return ret; | |
288 | } | |
289 | ||
290 | /* caller must hold prepare_lock */ | |
291 | static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry) | |
292 | { | |
293 | struct clk *child; | |
b2476490 MT |
294 | int ret = -EINVAL;; |
295 | ||
296 | if (!clk || !pdentry) | |
297 | goto out; | |
298 | ||
299 | ret = clk_debug_create_one(clk, pdentry); | |
300 | ||
301 | if (ret) | |
302 | goto out; | |
303 | ||
b67bfe0d | 304 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
305 | clk_debug_create_subtree(child, clk->dentry); |
306 | ||
307 | ret = 0; | |
308 | out: | |
309 | return ret; | |
310 | } | |
311 | ||
312 | /** | |
313 | * clk_debug_register - add a clk node to the debugfs clk tree | |
314 | * @clk: the clk being added to the debugfs clk tree | |
315 | * | |
316 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been | |
317 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
318 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
319 | * | |
320 | * Caller must hold prepare_lock. Only clk_init calls this function (so | |
321 | * far) so this is taken care. | |
322 | */ | |
323 | static int clk_debug_register(struct clk *clk) | |
324 | { | |
325 | struct clk *parent; | |
326 | struct dentry *pdentry; | |
327 | int ret = 0; | |
328 | ||
329 | if (!inited) | |
330 | goto out; | |
331 | ||
332 | parent = clk->parent; | |
333 | ||
334 | /* | |
335 | * Check to see if a clk is a root clk. Also check that it is | |
336 | * safe to add this clk to debugfs | |
337 | */ | |
338 | if (!parent) | |
339 | if (clk->flags & CLK_IS_ROOT) | |
340 | pdentry = rootdir; | |
341 | else | |
342 | pdentry = orphandir; | |
343 | else | |
344 | if (parent->dentry) | |
345 | pdentry = parent->dentry; | |
346 | else | |
347 | goto out; | |
348 | ||
349 | ret = clk_debug_create_subtree(clk, pdentry); | |
350 | ||
351 | out: | |
352 | return ret; | |
353 | } | |
354 | ||
fcb0ee6a SN |
355 | /** |
356 | * clk_debug_unregister - remove a clk node from the debugfs clk tree | |
357 | * @clk: the clk being removed from the debugfs clk tree | |
358 | * | |
359 | * Dynamically removes a clk and all it's children clk nodes from the | |
360 | * debugfs clk tree if clk->dentry points to debugfs created by | |
361 | * clk_debug_register in __clk_init. | |
362 | * | |
363 | * Caller must hold prepare_lock. | |
364 | */ | |
365 | static void clk_debug_unregister(struct clk *clk) | |
366 | { | |
367 | debugfs_remove_recursive(clk->dentry); | |
368 | } | |
369 | ||
b33d212f UH |
370 | /** |
371 | * clk_debug_reparent - reparent clk node in the debugfs clk tree | |
372 | * @clk: the clk being reparented | |
373 | * @new_parent: the new clk parent, may be NULL | |
374 | * | |
375 | * Rename clk entry in the debugfs clk tree if debugfs has been | |
376 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
377 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
378 | * | |
379 | * Caller must hold prepare_lock. | |
380 | */ | |
381 | static void clk_debug_reparent(struct clk *clk, struct clk *new_parent) | |
382 | { | |
383 | struct dentry *d; | |
384 | struct dentry *new_parent_d; | |
385 | ||
386 | if (!inited) | |
387 | return; | |
388 | ||
389 | if (new_parent) | |
390 | new_parent_d = new_parent->dentry; | |
391 | else | |
392 | new_parent_d = orphandir; | |
393 | ||
394 | d = debugfs_rename(clk->dentry->d_parent, clk->dentry, | |
395 | new_parent_d, clk->name); | |
396 | if (d) | |
397 | clk->dentry = d; | |
398 | else | |
399 | pr_debug("%s: failed to rename debugfs entry for %s\n", | |
400 | __func__, clk->name); | |
401 | } | |
402 | ||
b2476490 MT |
403 | /** |
404 | * clk_debug_init - lazily create the debugfs clk tree visualization | |
405 | * | |
406 | * clks are often initialized very early during boot before memory can | |
407 | * be dynamically allocated and well before debugfs is setup. | |
408 | * clk_debug_init walks the clk tree hierarchy while holding | |
409 | * prepare_lock and creates the topology as part of a late_initcall, | |
410 | * thus insuring that clks initialized very early will still be | |
411 | * represented in the debugfs clk tree. This function should only be | |
412 | * called once at boot-time, and all other clks added dynamically will | |
413 | * be done so with clk_debug_register. | |
414 | */ | |
415 | static int __init clk_debug_init(void) | |
416 | { | |
417 | struct clk *clk; | |
1af599df | 418 | struct dentry *d; |
b2476490 MT |
419 | |
420 | rootdir = debugfs_create_dir("clk", NULL); | |
421 | ||
422 | if (!rootdir) | |
423 | return -ENOMEM; | |
424 | ||
1af599df PG |
425 | d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, NULL, |
426 | &clk_summary_fops); | |
427 | if (!d) | |
428 | return -ENOMEM; | |
429 | ||
bddca894 PG |
430 | d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, NULL, |
431 | &clk_dump_fops); | |
432 | if (!d) | |
433 | return -ENOMEM; | |
434 | ||
b2476490 MT |
435 | orphandir = debugfs_create_dir("orphans", rootdir); |
436 | ||
437 | if (!orphandir) | |
438 | return -ENOMEM; | |
439 | ||
eab89f69 | 440 | clk_prepare_lock(); |
b2476490 | 441 | |
b67bfe0d | 442 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
443 | clk_debug_create_subtree(clk, rootdir); |
444 | ||
b67bfe0d | 445 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
b2476490 MT |
446 | clk_debug_create_subtree(clk, orphandir); |
447 | ||
448 | inited = 1; | |
449 | ||
eab89f69 | 450 | clk_prepare_unlock(); |
b2476490 MT |
451 | |
452 | return 0; | |
453 | } | |
454 | late_initcall(clk_debug_init); | |
455 | #else | |
456 | static inline int clk_debug_register(struct clk *clk) { return 0; } | |
b33d212f UH |
457 | static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent) |
458 | { | |
459 | } | |
fcb0ee6a SN |
460 | static inline void clk_debug_unregister(struct clk *clk) |
461 | { | |
462 | } | |
70d347e6 | 463 | #endif |
b2476490 | 464 | |
1c155b3d UH |
465 | /* caller must hold prepare_lock */ |
466 | static void clk_unprepare_unused_subtree(struct clk *clk) | |
467 | { | |
468 | struct clk *child; | |
469 | ||
470 | if (!clk) | |
471 | return; | |
472 | ||
473 | hlist_for_each_entry(child, &clk->children, child_node) | |
474 | clk_unprepare_unused_subtree(child); | |
475 | ||
476 | if (clk->prepare_count) | |
477 | return; | |
478 | ||
479 | if (clk->flags & CLK_IGNORE_UNUSED) | |
480 | return; | |
481 | ||
3cc8247f UH |
482 | if (__clk_is_prepared(clk)) { |
483 | if (clk->ops->unprepare_unused) | |
484 | clk->ops->unprepare_unused(clk->hw); | |
485 | else if (clk->ops->unprepare) | |
1c155b3d | 486 | clk->ops->unprepare(clk->hw); |
3cc8247f | 487 | } |
1c155b3d UH |
488 | } |
489 | ||
b2476490 MT |
490 | /* caller must hold prepare_lock */ |
491 | static void clk_disable_unused_subtree(struct clk *clk) | |
492 | { | |
493 | struct clk *child; | |
b2476490 MT |
494 | unsigned long flags; |
495 | ||
496 | if (!clk) | |
497 | goto out; | |
498 | ||
b67bfe0d | 499 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
500 | clk_disable_unused_subtree(child); |
501 | ||
eab89f69 | 502 | flags = clk_enable_lock(); |
b2476490 MT |
503 | |
504 | if (clk->enable_count) | |
505 | goto unlock_out; | |
506 | ||
507 | if (clk->flags & CLK_IGNORE_UNUSED) | |
508 | goto unlock_out; | |
509 | ||
7c045a55 MT |
510 | /* |
511 | * some gate clocks have special needs during the disable-unused | |
512 | * sequence. call .disable_unused if available, otherwise fall | |
513 | * back to .disable | |
514 | */ | |
515 | if (__clk_is_enabled(clk)) { | |
516 | if (clk->ops->disable_unused) | |
517 | clk->ops->disable_unused(clk->hw); | |
518 | else if (clk->ops->disable) | |
519 | clk->ops->disable(clk->hw); | |
520 | } | |
b2476490 MT |
521 | |
522 | unlock_out: | |
eab89f69 | 523 | clk_enable_unlock(flags); |
b2476490 MT |
524 | |
525 | out: | |
526 | return; | |
527 | } | |
528 | ||
1e435256 OJ |
529 | static bool clk_ignore_unused; |
530 | static int __init clk_ignore_unused_setup(char *__unused) | |
531 | { | |
532 | clk_ignore_unused = true; | |
533 | return 1; | |
534 | } | |
535 | __setup("clk_ignore_unused", clk_ignore_unused_setup); | |
536 | ||
b2476490 MT |
537 | static int clk_disable_unused(void) |
538 | { | |
539 | struct clk *clk; | |
b2476490 | 540 | |
1e435256 OJ |
541 | if (clk_ignore_unused) { |
542 | pr_warn("clk: Not disabling unused clocks\n"); | |
543 | return 0; | |
544 | } | |
545 | ||
eab89f69 | 546 | clk_prepare_lock(); |
b2476490 | 547 | |
b67bfe0d | 548 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
549 | clk_disable_unused_subtree(clk); |
550 | ||
b67bfe0d | 551 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
b2476490 MT |
552 | clk_disable_unused_subtree(clk); |
553 | ||
1c155b3d UH |
554 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
555 | clk_unprepare_unused_subtree(clk); | |
556 | ||
557 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) | |
558 | clk_unprepare_unused_subtree(clk); | |
559 | ||
eab89f69 | 560 | clk_prepare_unlock(); |
b2476490 MT |
561 | |
562 | return 0; | |
563 | } | |
d41d5805 | 564 | late_initcall_sync(clk_disable_unused); |
b2476490 MT |
565 | |
566 | /*** helper functions ***/ | |
567 | ||
65800b2c | 568 | const char *__clk_get_name(struct clk *clk) |
b2476490 MT |
569 | { |
570 | return !clk ? NULL : clk->name; | |
571 | } | |
4895084c | 572 | EXPORT_SYMBOL_GPL(__clk_get_name); |
b2476490 | 573 | |
65800b2c | 574 | struct clk_hw *__clk_get_hw(struct clk *clk) |
b2476490 MT |
575 | { |
576 | return !clk ? NULL : clk->hw; | |
577 | } | |
578 | ||
65800b2c | 579 | u8 __clk_get_num_parents(struct clk *clk) |
b2476490 | 580 | { |
2ac6b1f5 | 581 | return !clk ? 0 : clk->num_parents; |
b2476490 MT |
582 | } |
583 | ||
65800b2c | 584 | struct clk *__clk_get_parent(struct clk *clk) |
b2476490 MT |
585 | { |
586 | return !clk ? NULL : clk->parent; | |
587 | } | |
588 | ||
7ef3dcc8 JH |
589 | struct clk *clk_get_parent_by_index(struct clk *clk, u8 index) |
590 | { | |
591 | if (!clk || index >= clk->num_parents) | |
592 | return NULL; | |
593 | else if (!clk->parents) | |
594 | return __clk_lookup(clk->parent_names[index]); | |
595 | else if (!clk->parents[index]) | |
596 | return clk->parents[index] = | |
597 | __clk_lookup(clk->parent_names[index]); | |
598 | else | |
599 | return clk->parents[index]; | |
600 | } | |
601 | ||
65800b2c | 602 | unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 603 | { |
2ac6b1f5 | 604 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
605 | } |
606 | ||
65800b2c | 607 | unsigned int __clk_get_prepare_count(struct clk *clk) |
b2476490 | 608 | { |
2ac6b1f5 | 609 | return !clk ? 0 : clk->prepare_count; |
b2476490 MT |
610 | } |
611 | ||
612 | unsigned long __clk_get_rate(struct clk *clk) | |
613 | { | |
614 | unsigned long ret; | |
615 | ||
616 | if (!clk) { | |
34e44fe8 | 617 | ret = 0; |
b2476490 MT |
618 | goto out; |
619 | } | |
620 | ||
621 | ret = clk->rate; | |
622 | ||
623 | if (clk->flags & CLK_IS_ROOT) | |
624 | goto out; | |
625 | ||
626 | if (!clk->parent) | |
34e44fe8 | 627 | ret = 0; |
b2476490 MT |
628 | |
629 | out: | |
630 | return ret; | |
631 | } | |
632 | ||
5279fc40 BB |
633 | unsigned long __clk_get_accuracy(struct clk *clk) |
634 | { | |
635 | if (!clk) | |
636 | return 0; | |
637 | ||
638 | return clk->accuracy; | |
639 | } | |
640 | ||
65800b2c | 641 | unsigned long __clk_get_flags(struct clk *clk) |
b2476490 | 642 | { |
2ac6b1f5 | 643 | return !clk ? 0 : clk->flags; |
b2476490 | 644 | } |
b05c6836 | 645 | EXPORT_SYMBOL_GPL(__clk_get_flags); |
b2476490 | 646 | |
3d6ee287 UH |
647 | bool __clk_is_prepared(struct clk *clk) |
648 | { | |
649 | int ret; | |
650 | ||
651 | if (!clk) | |
652 | return false; | |
653 | ||
654 | /* | |
655 | * .is_prepared is optional for clocks that can prepare | |
656 | * fall back to software usage counter if it is missing | |
657 | */ | |
658 | if (!clk->ops->is_prepared) { | |
659 | ret = clk->prepare_count ? 1 : 0; | |
660 | goto out; | |
661 | } | |
662 | ||
663 | ret = clk->ops->is_prepared(clk->hw); | |
664 | out: | |
665 | return !!ret; | |
666 | } | |
667 | ||
2ac6b1f5 | 668 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
669 | { |
670 | int ret; | |
671 | ||
672 | if (!clk) | |
2ac6b1f5 | 673 | return false; |
b2476490 MT |
674 | |
675 | /* | |
676 | * .is_enabled is only mandatory for clocks that gate | |
677 | * fall back to software usage counter if .is_enabled is missing | |
678 | */ | |
679 | if (!clk->ops->is_enabled) { | |
680 | ret = clk->enable_count ? 1 : 0; | |
681 | goto out; | |
682 | } | |
683 | ||
684 | ret = clk->ops->is_enabled(clk->hw); | |
685 | out: | |
2ac6b1f5 | 686 | return !!ret; |
b2476490 MT |
687 | } |
688 | ||
689 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
690 | { | |
691 | struct clk *child; | |
692 | struct clk *ret; | |
b2476490 MT |
693 | |
694 | if (!strcmp(clk->name, name)) | |
695 | return clk; | |
696 | ||
b67bfe0d | 697 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
698 | ret = __clk_lookup_subtree(name, child); |
699 | if (ret) | |
700 | return ret; | |
701 | } | |
702 | ||
703 | return NULL; | |
704 | } | |
705 | ||
706 | struct clk *__clk_lookup(const char *name) | |
707 | { | |
708 | struct clk *root_clk; | |
709 | struct clk *ret; | |
b2476490 MT |
710 | |
711 | if (!name) | |
712 | return NULL; | |
713 | ||
714 | /* search the 'proper' clk tree first */ | |
b67bfe0d | 715 | hlist_for_each_entry(root_clk, &clk_root_list, child_node) { |
b2476490 MT |
716 | ret = __clk_lookup_subtree(name, root_clk); |
717 | if (ret) | |
718 | return ret; | |
719 | } | |
720 | ||
721 | /* if not found, then search the orphan tree */ | |
b67bfe0d | 722 | hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { |
b2476490 MT |
723 | ret = __clk_lookup_subtree(name, root_clk); |
724 | if (ret) | |
725 | return ret; | |
726 | } | |
727 | ||
728 | return NULL; | |
729 | } | |
730 | ||
e366fdd7 JH |
731 | /* |
732 | * Helper for finding best parent to provide a given frequency. This can be used | |
733 | * directly as a determine_rate callback (e.g. for a mux), or from a more | |
734 | * complex clock that may combine a mux with other operations. | |
735 | */ | |
736 | long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, | |
737 | unsigned long *best_parent_rate, | |
738 | struct clk **best_parent_p) | |
739 | { | |
740 | struct clk *clk = hw->clk, *parent, *best_parent = NULL; | |
741 | int i, num_parents; | |
742 | unsigned long parent_rate, best = 0; | |
743 | ||
744 | /* if NO_REPARENT flag set, pass through to current parent */ | |
745 | if (clk->flags & CLK_SET_RATE_NO_REPARENT) { | |
746 | parent = clk->parent; | |
747 | if (clk->flags & CLK_SET_RATE_PARENT) | |
748 | best = __clk_round_rate(parent, rate); | |
749 | else if (parent) | |
750 | best = __clk_get_rate(parent); | |
751 | else | |
752 | best = __clk_get_rate(clk); | |
753 | goto out; | |
754 | } | |
755 | ||
756 | /* find the parent that can provide the fastest rate <= rate */ | |
757 | num_parents = clk->num_parents; | |
758 | for (i = 0; i < num_parents; i++) { | |
759 | parent = clk_get_parent_by_index(clk, i); | |
760 | if (!parent) | |
761 | continue; | |
762 | if (clk->flags & CLK_SET_RATE_PARENT) | |
763 | parent_rate = __clk_round_rate(parent, rate); | |
764 | else | |
765 | parent_rate = __clk_get_rate(parent); | |
766 | if (parent_rate <= rate && parent_rate > best) { | |
767 | best_parent = parent; | |
768 | best = parent_rate; | |
769 | } | |
770 | } | |
771 | ||
772 | out: | |
773 | if (best_parent) | |
774 | *best_parent_p = best_parent; | |
775 | *best_parent_rate = best; | |
776 | ||
777 | return best; | |
778 | } | |
779 | ||
b2476490 MT |
780 | /*** clk api ***/ |
781 | ||
782 | void __clk_unprepare(struct clk *clk) | |
783 | { | |
784 | if (!clk) | |
785 | return; | |
786 | ||
787 | if (WARN_ON(clk->prepare_count == 0)) | |
788 | return; | |
789 | ||
790 | if (--clk->prepare_count > 0) | |
791 | return; | |
792 | ||
793 | WARN_ON(clk->enable_count > 0); | |
794 | ||
795 | if (clk->ops->unprepare) | |
796 | clk->ops->unprepare(clk->hw); | |
797 | ||
798 | __clk_unprepare(clk->parent); | |
799 | } | |
800 | ||
801 | /** | |
802 | * clk_unprepare - undo preparation of a clock source | |
24ee1a08 | 803 | * @clk: the clk being unprepared |
b2476490 MT |
804 | * |
805 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
806 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
807 | * if the operation may sleep. One example is a clk which is accessed over | |
808 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
809 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
810 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
811 | */ | |
812 | void clk_unprepare(struct clk *clk) | |
813 | { | |
eab89f69 | 814 | clk_prepare_lock(); |
b2476490 | 815 | __clk_unprepare(clk); |
eab89f69 | 816 | clk_prepare_unlock(); |
b2476490 MT |
817 | } |
818 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
819 | ||
820 | int __clk_prepare(struct clk *clk) | |
821 | { | |
822 | int ret = 0; | |
823 | ||
824 | if (!clk) | |
825 | return 0; | |
826 | ||
827 | if (clk->prepare_count == 0) { | |
828 | ret = __clk_prepare(clk->parent); | |
829 | if (ret) | |
830 | return ret; | |
831 | ||
832 | if (clk->ops->prepare) { | |
833 | ret = clk->ops->prepare(clk->hw); | |
834 | if (ret) { | |
835 | __clk_unprepare(clk->parent); | |
836 | return ret; | |
837 | } | |
838 | } | |
839 | } | |
840 | ||
841 | clk->prepare_count++; | |
842 | ||
843 | return 0; | |
844 | } | |
845 | ||
846 | /** | |
847 | * clk_prepare - prepare a clock source | |
848 | * @clk: the clk being prepared | |
849 | * | |
850 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
851 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
852 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
853 | * the complex case a clk ungate operation may require a fast and a slow part. | |
854 | * It is this reason that clk_prepare and clk_enable are not mutually | |
855 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
856 | * Returns 0 on success, -EERROR otherwise. | |
857 | */ | |
858 | int clk_prepare(struct clk *clk) | |
859 | { | |
860 | int ret; | |
861 | ||
eab89f69 | 862 | clk_prepare_lock(); |
b2476490 | 863 | ret = __clk_prepare(clk); |
eab89f69 | 864 | clk_prepare_unlock(); |
b2476490 MT |
865 | |
866 | return ret; | |
867 | } | |
868 | EXPORT_SYMBOL_GPL(clk_prepare); | |
869 | ||
870 | static void __clk_disable(struct clk *clk) | |
871 | { | |
872 | if (!clk) | |
873 | return; | |
874 | ||
e47c6a34 FW |
875 | if (WARN_ON(IS_ERR(clk))) |
876 | return; | |
877 | ||
b2476490 MT |
878 | if (WARN_ON(clk->enable_count == 0)) |
879 | return; | |
880 | ||
881 | if (--clk->enable_count > 0) | |
882 | return; | |
883 | ||
884 | if (clk->ops->disable) | |
885 | clk->ops->disable(clk->hw); | |
886 | ||
887 | __clk_disable(clk->parent); | |
888 | } | |
889 | ||
890 | /** | |
891 | * clk_disable - gate a clock | |
892 | * @clk: the clk being gated | |
893 | * | |
894 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
895 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
896 | * clk if the operation is fast and will never sleep. One example is a | |
897 | * SoC-internal clk which is controlled via simple register writes. In the | |
898 | * complex case a clk gate operation may require a fast and a slow part. It is | |
899 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
900 | * In fact clk_disable must be called before clk_unprepare. | |
901 | */ | |
902 | void clk_disable(struct clk *clk) | |
903 | { | |
904 | unsigned long flags; | |
905 | ||
eab89f69 | 906 | flags = clk_enable_lock(); |
b2476490 | 907 | __clk_disable(clk); |
eab89f69 | 908 | clk_enable_unlock(flags); |
b2476490 MT |
909 | } |
910 | EXPORT_SYMBOL_GPL(clk_disable); | |
911 | ||
912 | static int __clk_enable(struct clk *clk) | |
913 | { | |
914 | int ret = 0; | |
915 | ||
916 | if (!clk) | |
917 | return 0; | |
918 | ||
919 | if (WARN_ON(clk->prepare_count == 0)) | |
920 | return -ESHUTDOWN; | |
921 | ||
922 | if (clk->enable_count == 0) { | |
923 | ret = __clk_enable(clk->parent); | |
924 | ||
925 | if (ret) | |
926 | return ret; | |
927 | ||
928 | if (clk->ops->enable) { | |
929 | ret = clk->ops->enable(clk->hw); | |
930 | if (ret) { | |
931 | __clk_disable(clk->parent); | |
932 | return ret; | |
933 | } | |
934 | } | |
935 | } | |
936 | ||
937 | clk->enable_count++; | |
938 | return 0; | |
939 | } | |
940 | ||
941 | /** | |
942 | * clk_enable - ungate a clock | |
943 | * @clk: the clk being ungated | |
944 | * | |
945 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
946 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
947 | * if the operation will never sleep. One example is a SoC-internal clk which | |
948 | * is controlled via simple register writes. In the complex case a clk ungate | |
949 | * operation may require a fast and a slow part. It is this reason that | |
950 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
951 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
952 | * otherwise. | |
953 | */ | |
954 | int clk_enable(struct clk *clk) | |
955 | { | |
956 | unsigned long flags; | |
957 | int ret; | |
958 | ||
eab89f69 | 959 | flags = clk_enable_lock(); |
b2476490 | 960 | ret = __clk_enable(clk); |
eab89f69 | 961 | clk_enable_unlock(flags); |
b2476490 MT |
962 | |
963 | return ret; | |
964 | } | |
965 | EXPORT_SYMBOL_GPL(clk_enable); | |
966 | ||
b2476490 MT |
967 | /** |
968 | * __clk_round_rate - round the given rate for a clk | |
969 | * @clk: round the rate of this clock | |
24ee1a08 | 970 | * @rate: the rate which is to be rounded |
b2476490 MT |
971 | * |
972 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
973 | */ | |
974 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
975 | { | |
81536e07 | 976 | unsigned long parent_rate = 0; |
71472c0c | 977 | struct clk *parent; |
b2476490 MT |
978 | |
979 | if (!clk) | |
2ac6b1f5 | 980 | return 0; |
b2476490 | 981 | |
71472c0c JH |
982 | parent = clk->parent; |
983 | if (parent) | |
984 | parent_rate = parent->rate; | |
985 | ||
986 | if (clk->ops->determine_rate) | |
987 | return clk->ops->determine_rate(clk->hw, rate, &parent_rate, | |
988 | &parent); | |
989 | else if (clk->ops->round_rate) | |
990 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); | |
991 | else if (clk->flags & CLK_SET_RATE_PARENT) | |
992 | return __clk_round_rate(clk->parent, rate); | |
993 | else | |
994 | return clk->rate; | |
b2476490 MT |
995 | } |
996 | ||
997 | /** | |
998 | * clk_round_rate - round the given rate for a clk | |
999 | * @clk: the clk for which we are rounding a rate | |
1000 | * @rate: the rate which is to be rounded | |
1001 | * | |
1002 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
1003 | * use which is then returned. If clk doesn't support round_rate operation | |
1004 | * then the parent rate is returned. | |
1005 | */ | |
1006 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
1007 | { | |
1008 | unsigned long ret; | |
1009 | ||
eab89f69 | 1010 | clk_prepare_lock(); |
b2476490 | 1011 | ret = __clk_round_rate(clk, rate); |
eab89f69 | 1012 | clk_prepare_unlock(); |
b2476490 MT |
1013 | |
1014 | return ret; | |
1015 | } | |
1016 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
1017 | ||
1018 | /** | |
1019 | * __clk_notify - call clk notifier chain | |
1020 | * @clk: struct clk * that is changing rate | |
1021 | * @msg: clk notifier type (see include/linux/clk.h) | |
1022 | * @old_rate: old clk rate | |
1023 | * @new_rate: new clk rate | |
1024 | * | |
1025 | * Triggers a notifier call chain on the clk rate-change notification | |
1026 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
1027 | * and current rates to the notifier callback. Intended to be called by | |
1028 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
1029 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
1030 | * a driver returns that. | |
1031 | */ | |
1032 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
1033 | unsigned long old_rate, unsigned long new_rate) | |
1034 | { | |
1035 | struct clk_notifier *cn; | |
1036 | struct clk_notifier_data cnd; | |
1037 | int ret = NOTIFY_DONE; | |
1038 | ||
1039 | cnd.clk = clk; | |
1040 | cnd.old_rate = old_rate; | |
1041 | cnd.new_rate = new_rate; | |
1042 | ||
1043 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
1044 | if (cn->clk == clk) { | |
1045 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
1046 | &cnd); | |
1047 | break; | |
1048 | } | |
1049 | } | |
1050 | ||
1051 | return ret; | |
1052 | } | |
1053 | ||
5279fc40 BB |
1054 | /** |
1055 | * __clk_recalc_accuracies | |
1056 | * @clk: first clk in the subtree | |
1057 | * | |
1058 | * Walks the subtree of clks starting with clk and recalculates accuracies as | |
1059 | * it goes. Note that if a clk does not implement the .recalc_accuracy | |
1060 | * callback then it is assumed that the clock will take on the accuracy of it's | |
1061 | * parent. | |
1062 | * | |
1063 | * Caller must hold prepare_lock. | |
1064 | */ | |
1065 | static void __clk_recalc_accuracies(struct clk *clk) | |
1066 | { | |
1067 | unsigned long parent_accuracy = 0; | |
1068 | struct clk *child; | |
1069 | ||
1070 | if (clk->parent) | |
1071 | parent_accuracy = clk->parent->accuracy; | |
1072 | ||
1073 | if (clk->ops->recalc_accuracy) | |
1074 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1075 | parent_accuracy); | |
1076 | else | |
1077 | clk->accuracy = parent_accuracy; | |
1078 | ||
1079 | hlist_for_each_entry(child, &clk->children, child_node) | |
1080 | __clk_recalc_accuracies(child); | |
1081 | } | |
1082 | ||
1083 | /** | |
1084 | * clk_get_accuracy - return the accuracy of clk | |
1085 | * @clk: the clk whose accuracy is being returned | |
1086 | * | |
1087 | * Simply returns the cached accuracy of the clk, unless | |
1088 | * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be | |
1089 | * issued. | |
1090 | * If clk is NULL then returns 0. | |
1091 | */ | |
1092 | long clk_get_accuracy(struct clk *clk) | |
1093 | { | |
1094 | unsigned long accuracy; | |
1095 | ||
1096 | clk_prepare_lock(); | |
1097 | if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE)) | |
1098 | __clk_recalc_accuracies(clk); | |
1099 | ||
1100 | accuracy = __clk_get_accuracy(clk); | |
1101 | clk_prepare_unlock(); | |
1102 | ||
1103 | return accuracy; | |
1104 | } | |
1105 | EXPORT_SYMBOL_GPL(clk_get_accuracy); | |
1106 | ||
b2476490 MT |
1107 | /** |
1108 | * __clk_recalc_rates | |
1109 | * @clk: first clk in the subtree | |
1110 | * @msg: notification type (see include/linux/clk.h) | |
1111 | * | |
1112 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
1113 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
24ee1a08 | 1114 | * it is assumed that the clock will take on the rate of its parent. |
b2476490 MT |
1115 | * |
1116 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
1117 | * if necessary. | |
1118 | * | |
1119 | * Caller must hold prepare_lock. | |
1120 | */ | |
1121 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
1122 | { | |
1123 | unsigned long old_rate; | |
1124 | unsigned long parent_rate = 0; | |
b2476490 MT |
1125 | struct clk *child; |
1126 | ||
1127 | old_rate = clk->rate; | |
1128 | ||
1129 | if (clk->parent) | |
1130 | parent_rate = clk->parent->rate; | |
1131 | ||
1132 | if (clk->ops->recalc_rate) | |
1133 | clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
1134 | else | |
1135 | clk->rate = parent_rate; | |
1136 | ||
1137 | /* | |
1138 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
1139 | * & ABORT_RATE_CHANGE notifiers | |
1140 | */ | |
1141 | if (clk->notifier_count && msg) | |
1142 | __clk_notify(clk, msg, old_rate, clk->rate); | |
1143 | ||
b67bfe0d | 1144 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
1145 | __clk_recalc_rates(child, msg); |
1146 | } | |
1147 | ||
a093bde2 UH |
1148 | /** |
1149 | * clk_get_rate - return the rate of clk | |
1150 | * @clk: the clk whose rate is being returned | |
1151 | * | |
1152 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
1153 | * is set, which means a recalc_rate will be issued. | |
1154 | * If clk is NULL then returns 0. | |
1155 | */ | |
1156 | unsigned long clk_get_rate(struct clk *clk) | |
1157 | { | |
1158 | unsigned long rate; | |
1159 | ||
eab89f69 | 1160 | clk_prepare_lock(); |
a093bde2 UH |
1161 | |
1162 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
1163 | __clk_recalc_rates(clk, 0); | |
1164 | ||
1165 | rate = __clk_get_rate(clk); | |
eab89f69 | 1166 | clk_prepare_unlock(); |
a093bde2 UH |
1167 | |
1168 | return rate; | |
1169 | } | |
1170 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
1171 | ||
f1c8b2ed | 1172 | static int clk_fetch_parent_index(struct clk *clk, struct clk *parent) |
4935b22c | 1173 | { |
f1c8b2ed | 1174 | int i; |
4935b22c | 1175 | |
f1c8b2ed | 1176 | if (!clk->parents) { |
96a7ed90 TF |
1177 | clk->parents = kcalloc(clk->num_parents, |
1178 | sizeof(struct clk *), GFP_KERNEL); | |
f1c8b2ed TF |
1179 | if (!clk->parents) |
1180 | return -ENOMEM; | |
1181 | } | |
4935b22c JH |
1182 | |
1183 | /* | |
1184 | * find index of new parent clock using cached parent ptrs, | |
1185 | * or if not yet cached, use string name comparison and cache | |
1186 | * them now to avoid future calls to __clk_lookup. | |
1187 | */ | |
1188 | for (i = 0; i < clk->num_parents; i++) { | |
da0f0b2c | 1189 | if (clk->parents[i] == parent) |
f1c8b2ed | 1190 | return i; |
da0f0b2c TF |
1191 | |
1192 | if (clk->parents[i]) | |
1193 | continue; | |
1194 | ||
1195 | if (!strcmp(clk->parent_names[i], parent->name)) { | |
1196 | clk->parents[i] = __clk_lookup(parent->name); | |
f1c8b2ed | 1197 | return i; |
4935b22c JH |
1198 | } |
1199 | } | |
1200 | ||
f1c8b2ed | 1201 | return -EINVAL; |
4935b22c JH |
1202 | } |
1203 | ||
1204 | static void clk_reparent(struct clk *clk, struct clk *new_parent) | |
1205 | { | |
1206 | hlist_del(&clk->child_node); | |
1207 | ||
903efc55 JH |
1208 | if (new_parent) { |
1209 | /* avoid duplicate POST_RATE_CHANGE notifications */ | |
1210 | if (new_parent->new_child == clk) | |
1211 | new_parent->new_child = NULL; | |
1212 | ||
4935b22c | 1213 | hlist_add_head(&clk->child_node, &new_parent->children); |
903efc55 | 1214 | } else { |
4935b22c | 1215 | hlist_add_head(&clk->child_node, &clk_orphan_list); |
903efc55 | 1216 | } |
4935b22c JH |
1217 | |
1218 | clk->parent = new_parent; | |
1219 | } | |
1220 | ||
1221 | static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) | |
1222 | { | |
1223 | unsigned long flags; | |
1224 | int ret = 0; | |
1225 | struct clk *old_parent = clk->parent; | |
1226 | ||
1227 | /* | |
1228 | * Migrate prepare state between parents and prevent race with | |
1229 | * clk_enable(). | |
1230 | * | |
1231 | * If the clock is not prepared, then a race with | |
1232 | * clk_enable/disable() is impossible since we already have the | |
1233 | * prepare lock (future calls to clk_enable() need to be preceded by | |
1234 | * a clk_prepare()). | |
1235 | * | |
1236 | * If the clock is prepared, migrate the prepared state to the new | |
1237 | * parent and also protect against a race with clk_enable() by | |
1238 | * forcing the clock and the new parent on. This ensures that all | |
1239 | * future calls to clk_enable() are practically NOPs with respect to | |
1240 | * hardware and software states. | |
1241 | * | |
1242 | * See also: Comment for clk_set_parent() below. | |
1243 | */ | |
1244 | if (clk->prepare_count) { | |
1245 | __clk_prepare(parent); | |
1246 | clk_enable(parent); | |
1247 | clk_enable(clk); | |
1248 | } | |
1249 | ||
1250 | /* update the clk tree topology */ | |
1251 | flags = clk_enable_lock(); | |
1252 | clk_reparent(clk, parent); | |
1253 | clk_enable_unlock(flags); | |
1254 | ||
1255 | /* change clock input source */ | |
1256 | if (parent && clk->ops->set_parent) | |
1257 | ret = clk->ops->set_parent(clk->hw, p_index); | |
1258 | ||
1259 | if (ret) { | |
1260 | flags = clk_enable_lock(); | |
1261 | clk_reparent(clk, old_parent); | |
1262 | clk_enable_unlock(flags); | |
1263 | ||
1264 | if (clk->prepare_count) { | |
1265 | clk_disable(clk); | |
1266 | clk_disable(parent); | |
1267 | __clk_unprepare(parent); | |
1268 | } | |
1269 | return ret; | |
1270 | } | |
1271 | ||
1272 | /* | |
1273 | * Finish the migration of prepare state and undo the changes done | |
1274 | * for preventing a race with clk_enable(). | |
1275 | */ | |
1276 | if (clk->prepare_count) { | |
1277 | clk_disable(clk); | |
1278 | clk_disable(old_parent); | |
1279 | __clk_unprepare(old_parent); | |
1280 | } | |
1281 | ||
1282 | /* update debugfs with new clk tree topology */ | |
1283 | clk_debug_reparent(clk, parent); | |
1284 | return 0; | |
1285 | } | |
1286 | ||
b2476490 MT |
1287 | /** |
1288 | * __clk_speculate_rates | |
1289 | * @clk: first clk in the subtree | |
1290 | * @parent_rate: the "future" rate of clk's parent | |
1291 | * | |
1292 | * Walks the subtree of clks starting with clk, speculating rates as it | |
1293 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
1294 | * | |
1295 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
1296 | * pre-rate change notifications and returns early if no clks in the | |
1297 | * subtree have subscribed to the notifications. Note that if a clk does not | |
1298 | * implement the .recalc_rate callback then it is assumed that the clock will | |
24ee1a08 | 1299 | * take on the rate of its parent. |
b2476490 MT |
1300 | * |
1301 | * Caller must hold prepare_lock. | |
1302 | */ | |
1303 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
1304 | { | |
b2476490 MT |
1305 | struct clk *child; |
1306 | unsigned long new_rate; | |
1307 | int ret = NOTIFY_DONE; | |
1308 | ||
1309 | if (clk->ops->recalc_rate) | |
1310 | new_rate = clk->ops->recalc_rate(clk->hw, parent_rate); | |
1311 | else | |
1312 | new_rate = parent_rate; | |
1313 | ||
fb72a059 | 1314 | /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ |
b2476490 MT |
1315 | if (clk->notifier_count) |
1316 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
1317 | ||
fb72a059 | 1318 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1319 | goto out; |
1320 | ||
b67bfe0d | 1321 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 | 1322 | ret = __clk_speculate_rates(child, new_rate); |
fb72a059 | 1323 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1324 | break; |
1325 | } | |
1326 | ||
1327 | out: | |
1328 | return ret; | |
1329 | } | |
1330 | ||
71472c0c JH |
1331 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate, |
1332 | struct clk *new_parent, u8 p_index) | |
b2476490 MT |
1333 | { |
1334 | struct clk *child; | |
b2476490 MT |
1335 | |
1336 | clk->new_rate = new_rate; | |
71472c0c JH |
1337 | clk->new_parent = new_parent; |
1338 | clk->new_parent_index = p_index; | |
1339 | /* include clk in new parent's PRE_RATE_CHANGE notifications */ | |
1340 | clk->new_child = NULL; | |
1341 | if (new_parent && new_parent != clk->parent) | |
1342 | new_parent->new_child = clk; | |
b2476490 | 1343 | |
b67bfe0d | 1344 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
1345 | if (child->ops->recalc_rate) |
1346 | child->new_rate = child->ops->recalc_rate(child->hw, new_rate); | |
1347 | else | |
1348 | child->new_rate = new_rate; | |
71472c0c | 1349 | clk_calc_subtree(child, child->new_rate, NULL, 0); |
b2476490 MT |
1350 | } |
1351 | } | |
1352 | ||
1353 | /* | |
1354 | * calculate the new rates returning the topmost clock that has to be | |
1355 | * changed. | |
1356 | */ | |
1357 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
1358 | { | |
1359 | struct clk *top = clk; | |
71472c0c | 1360 | struct clk *old_parent, *parent; |
81536e07 | 1361 | unsigned long best_parent_rate = 0; |
b2476490 | 1362 | unsigned long new_rate; |
f1c8b2ed | 1363 | int p_index = 0; |
b2476490 | 1364 | |
7452b219 MT |
1365 | /* sanity */ |
1366 | if (IS_ERR_OR_NULL(clk)) | |
1367 | return NULL; | |
1368 | ||
63f5c3b2 | 1369 | /* save parent rate, if it exists */ |
71472c0c JH |
1370 | parent = old_parent = clk->parent; |
1371 | if (parent) | |
1372 | best_parent_rate = parent->rate; | |
1373 | ||
1374 | /* find the closest rate and parent clk/rate */ | |
1375 | if (clk->ops->determine_rate) { | |
1376 | new_rate = clk->ops->determine_rate(clk->hw, rate, | |
1377 | &best_parent_rate, | |
1378 | &parent); | |
1379 | } else if (clk->ops->round_rate) { | |
1380 | new_rate = clk->ops->round_rate(clk->hw, rate, | |
1381 | &best_parent_rate); | |
1382 | } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) { | |
1383 | /* pass-through clock without adjustable parent */ | |
1384 | clk->new_rate = clk->rate; | |
1385 | return NULL; | |
1386 | } else { | |
1387 | /* pass-through clock with adjustable parent */ | |
1388 | top = clk_calc_new_rates(parent, rate); | |
1389 | new_rate = parent->new_rate; | |
63f5c3b2 | 1390 | goto out; |
7452b219 MT |
1391 | } |
1392 | ||
71472c0c JH |
1393 | /* some clocks must be gated to change parent */ |
1394 | if (parent != old_parent && | |
1395 | (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1396 | pr_debug("%s: %s not gated but wants to reparent\n", | |
1397 | __func__, clk->name); | |
b2476490 MT |
1398 | return NULL; |
1399 | } | |
1400 | ||
71472c0c JH |
1401 | /* try finding the new parent index */ |
1402 | if (parent) { | |
1403 | p_index = clk_fetch_parent_index(clk, parent); | |
f1c8b2ed | 1404 | if (p_index < 0) { |
71472c0c JH |
1405 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1406 | __func__, parent->name, clk->name); | |
1407 | return NULL; | |
1408 | } | |
b2476490 MT |
1409 | } |
1410 | ||
71472c0c JH |
1411 | if ((clk->flags & CLK_SET_RATE_PARENT) && parent && |
1412 | best_parent_rate != parent->rate) | |
1413 | top = clk_calc_new_rates(parent, best_parent_rate); | |
b2476490 MT |
1414 | |
1415 | out: | |
71472c0c | 1416 | clk_calc_subtree(clk, new_rate, parent, p_index); |
b2476490 MT |
1417 | |
1418 | return top; | |
1419 | } | |
1420 | ||
1421 | /* | |
1422 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
1423 | * so that in case of an error we can walk down the whole tree again and | |
1424 | * abort the change. | |
1425 | */ | |
1426 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
1427 | { | |
71472c0c | 1428 | struct clk *child, *tmp_clk, *fail_clk = NULL; |
b2476490 MT |
1429 | int ret = NOTIFY_DONE; |
1430 | ||
1431 | if (clk->rate == clk->new_rate) | |
5fda6858 | 1432 | return NULL; |
b2476490 MT |
1433 | |
1434 | if (clk->notifier_count) { | |
1435 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
fb72a059 | 1436 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1437 | fail_clk = clk; |
1438 | } | |
1439 | ||
b67bfe0d | 1440 | hlist_for_each_entry(child, &clk->children, child_node) { |
71472c0c JH |
1441 | /* Skip children who will be reparented to another clock */ |
1442 | if (child->new_parent && child->new_parent != clk) | |
1443 | continue; | |
1444 | tmp_clk = clk_propagate_rate_change(child, event); | |
1445 | if (tmp_clk) | |
1446 | fail_clk = tmp_clk; | |
1447 | } | |
1448 | ||
1449 | /* handle the new child who might not be in clk->children yet */ | |
1450 | if (clk->new_child) { | |
1451 | tmp_clk = clk_propagate_rate_change(clk->new_child, event); | |
1452 | if (tmp_clk) | |
1453 | fail_clk = tmp_clk; | |
b2476490 MT |
1454 | } |
1455 | ||
1456 | return fail_clk; | |
1457 | } | |
1458 | ||
1459 | /* | |
1460 | * walk down a subtree and set the new rates notifying the rate | |
1461 | * change on the way | |
1462 | */ | |
1463 | static void clk_change_rate(struct clk *clk) | |
1464 | { | |
1465 | struct clk *child; | |
1466 | unsigned long old_rate; | |
bf47b4fd | 1467 | unsigned long best_parent_rate = 0; |
b2476490 MT |
1468 | |
1469 | old_rate = clk->rate; | |
1470 | ||
71472c0c JH |
1471 | /* set parent */ |
1472 | if (clk->new_parent && clk->new_parent != clk->parent) | |
1473 | __clk_set_parent(clk, clk->new_parent, clk->new_parent_index); | |
1474 | ||
bf47b4fd PM |
1475 | if (clk->parent) |
1476 | best_parent_rate = clk->parent->rate; | |
1477 | ||
b2476490 | 1478 | if (clk->ops->set_rate) |
bf47b4fd | 1479 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 MT |
1480 | |
1481 | if (clk->ops->recalc_rate) | |
bf47b4fd | 1482 | clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate); |
b2476490 | 1483 | else |
bf47b4fd | 1484 | clk->rate = best_parent_rate; |
b2476490 MT |
1485 | |
1486 | if (clk->notifier_count && old_rate != clk->rate) | |
1487 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
1488 | ||
71472c0c JH |
1489 | hlist_for_each_entry(child, &clk->children, child_node) { |
1490 | /* Skip children who will be reparented to another clock */ | |
1491 | if (child->new_parent && child->new_parent != clk) | |
1492 | continue; | |
b2476490 | 1493 | clk_change_rate(child); |
71472c0c JH |
1494 | } |
1495 | ||
1496 | /* handle the new child who might not be in clk->children yet */ | |
1497 | if (clk->new_child) | |
1498 | clk_change_rate(clk->new_child); | |
b2476490 MT |
1499 | } |
1500 | ||
1501 | /** | |
1502 | * clk_set_rate - specify a new rate for clk | |
1503 | * @clk: the clk whose rate is being changed | |
1504 | * @rate: the new rate for clk | |
1505 | * | |
5654dc94 | 1506 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 1507 | * |
5654dc94 MT |
1508 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
1509 | * propagate up to clk's parent; whether or not this happens depends on the | |
1510 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
1511 | * after calling .round_rate then upstream parent propagation is ignored. If | |
1512 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
24ee1a08 | 1513 | * up to clk's parent and set its rate. Upward propagation will continue |
5654dc94 MT |
1514 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or |
1515 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 1516 | * |
5654dc94 MT |
1517 | * Rate changes are accomplished via tree traversal that also recalculates the |
1518 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
1519 | * |
1520 | * Returns 0 on success, -EERROR otherwise. | |
1521 | */ | |
1522 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
1523 | { | |
1524 | struct clk *top, *fail_clk; | |
1525 | int ret = 0; | |
1526 | ||
89ac8d7a MT |
1527 | if (!clk) |
1528 | return 0; | |
1529 | ||
b2476490 | 1530 | /* prevent racing with updates to the clock topology */ |
eab89f69 | 1531 | clk_prepare_lock(); |
b2476490 MT |
1532 | |
1533 | /* bail early if nothing to do */ | |
34e452a1 | 1534 | if (rate == clk_get_rate(clk)) |
b2476490 MT |
1535 | goto out; |
1536 | ||
7e0fa1b5 | 1537 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
1538 | ret = -EBUSY; |
1539 | goto out; | |
1540 | } | |
1541 | ||
b2476490 MT |
1542 | /* calculate new rates and get the topmost changed clock */ |
1543 | top = clk_calc_new_rates(clk, rate); | |
1544 | if (!top) { | |
1545 | ret = -EINVAL; | |
1546 | goto out; | |
1547 | } | |
1548 | ||
1549 | /* notify that we are about to change rates */ | |
1550 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
1551 | if (fail_clk) { | |
1552 | pr_warn("%s: failed to set %s rate\n", __func__, | |
1553 | fail_clk->name); | |
1554 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
1555 | ret = -EBUSY; | |
1556 | goto out; | |
1557 | } | |
1558 | ||
1559 | /* change the rates */ | |
1560 | clk_change_rate(top); | |
1561 | ||
b2476490 | 1562 | out: |
eab89f69 | 1563 | clk_prepare_unlock(); |
b2476490 MT |
1564 | |
1565 | return ret; | |
1566 | } | |
1567 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
1568 | ||
1569 | /** | |
1570 | * clk_get_parent - return the parent of a clk | |
1571 | * @clk: the clk whose parent gets returned | |
1572 | * | |
1573 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
1574 | */ | |
1575 | struct clk *clk_get_parent(struct clk *clk) | |
1576 | { | |
1577 | struct clk *parent; | |
1578 | ||
eab89f69 | 1579 | clk_prepare_lock(); |
b2476490 | 1580 | parent = __clk_get_parent(clk); |
eab89f69 | 1581 | clk_prepare_unlock(); |
b2476490 MT |
1582 | |
1583 | return parent; | |
1584 | } | |
1585 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
1586 | ||
1587 | /* | |
1588 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
1589 | * optional for single-parent clocks. Always call .get_parent if it is | |
1590 | * available and WARN if it is missing for multi-parent clocks. | |
1591 | * | |
1592 | * For single-parent clocks without .get_parent, first check to see if the | |
1593 | * .parents array exists, and if so use it to avoid an expensive tree | |
1594 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
1595 | */ | |
1596 | static struct clk *__clk_init_parent(struct clk *clk) | |
1597 | { | |
1598 | struct clk *ret = NULL; | |
1599 | u8 index; | |
1600 | ||
1601 | /* handle the trivial cases */ | |
1602 | ||
1603 | if (!clk->num_parents) | |
1604 | goto out; | |
1605 | ||
1606 | if (clk->num_parents == 1) { | |
1607 | if (IS_ERR_OR_NULL(clk->parent)) | |
1608 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); | |
1609 | ret = clk->parent; | |
1610 | goto out; | |
1611 | } | |
1612 | ||
1613 | if (!clk->ops->get_parent) { | |
1614 | WARN(!clk->ops->get_parent, | |
1615 | "%s: multi-parent clocks must implement .get_parent\n", | |
1616 | __func__); | |
1617 | goto out; | |
1618 | }; | |
1619 | ||
1620 | /* | |
1621 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1622 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1623 | * clk->parent here; that is done by the calling function | |
1624 | */ | |
1625 | ||
1626 | index = clk->ops->get_parent(clk->hw); | |
1627 | ||
1628 | if (!clk->parents) | |
1629 | clk->parents = | |
96a7ed90 | 1630 | kcalloc(clk->num_parents, sizeof(struct clk *), |
b2476490 MT |
1631 | GFP_KERNEL); |
1632 | ||
7ef3dcc8 | 1633 | ret = clk_get_parent_by_index(clk, index); |
b2476490 MT |
1634 | |
1635 | out: | |
1636 | return ret; | |
1637 | } | |
1638 | ||
b33d212f UH |
1639 | void __clk_reparent(struct clk *clk, struct clk *new_parent) |
1640 | { | |
1641 | clk_reparent(clk, new_parent); | |
1642 | clk_debug_reparent(clk, new_parent); | |
5279fc40 | 1643 | __clk_recalc_accuracies(clk); |
b2476490 MT |
1644 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
1645 | } | |
1646 | ||
b2476490 MT |
1647 | /** |
1648 | * clk_set_parent - switch the parent of a mux clk | |
1649 | * @clk: the mux clk whose input we are switching | |
1650 | * @parent: the new input to clk | |
1651 | * | |
f8aa0bd5 SK |
1652 | * Re-parent clk to use parent as its new input source. If clk is in |
1653 | * prepared state, the clk will get enabled for the duration of this call. If | |
1654 | * that's not acceptable for a specific clk (Eg: the consumer can't handle | |
1655 | * that, the reparenting is glitchy in hardware, etc), use the | |
1656 | * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. | |
1657 | * | |
1658 | * After successfully changing clk's parent clk_set_parent will update the | |
1659 | * clk topology, sysfs topology and propagate rate recalculation via | |
1660 | * __clk_recalc_rates. | |
1661 | * | |
1662 | * Returns 0 on success, -EERROR otherwise. | |
b2476490 MT |
1663 | */ |
1664 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
1665 | { | |
1666 | int ret = 0; | |
f1c8b2ed | 1667 | int p_index = 0; |
031dcc9b | 1668 | unsigned long p_rate = 0; |
b2476490 | 1669 | |
89ac8d7a MT |
1670 | if (!clk) |
1671 | return 0; | |
1672 | ||
1673 | if (!clk->ops) | |
b2476490 MT |
1674 | return -EINVAL; |
1675 | ||
031dcc9b UH |
1676 | /* verify ops for for multi-parent clks */ |
1677 | if ((clk->num_parents > 1) && (!clk->ops->set_parent)) | |
b2476490 MT |
1678 | return -ENOSYS; |
1679 | ||
1680 | /* prevent racing with updates to the clock topology */ | |
eab89f69 | 1681 | clk_prepare_lock(); |
b2476490 MT |
1682 | |
1683 | if (clk->parent == parent) | |
1684 | goto out; | |
1685 | ||
031dcc9b UH |
1686 | /* check that we are allowed to re-parent if the clock is in use */ |
1687 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1688 | ret = -EBUSY; | |
1689 | goto out; | |
1690 | } | |
1691 | ||
1692 | /* try finding the new parent index */ | |
1693 | if (parent) { | |
1694 | p_index = clk_fetch_parent_index(clk, parent); | |
1695 | p_rate = parent->rate; | |
f1c8b2ed | 1696 | if (p_index < 0) { |
031dcc9b UH |
1697 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1698 | __func__, parent->name, clk->name); | |
f1c8b2ed | 1699 | ret = p_index; |
031dcc9b UH |
1700 | goto out; |
1701 | } | |
1702 | } | |
1703 | ||
b2476490 | 1704 | /* propagate PRE_RATE_CHANGE notifications */ |
f3aab5d6 | 1705 | ret = __clk_speculate_rates(clk, p_rate); |
b2476490 MT |
1706 | |
1707 | /* abort if a driver objects */ | |
fb72a059 | 1708 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1709 | goto out; |
1710 | ||
031dcc9b UH |
1711 | /* do the re-parent */ |
1712 | ret = __clk_set_parent(clk, parent, p_index); | |
b2476490 | 1713 | |
5279fc40 BB |
1714 | /* propagate rate an accuracy recalculation accordingly */ |
1715 | if (ret) { | |
b2476490 | 1716 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); |
5279fc40 | 1717 | } else { |
a68de8e4 | 1718 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
5279fc40 BB |
1719 | __clk_recalc_accuracies(clk); |
1720 | } | |
b2476490 MT |
1721 | |
1722 | out: | |
eab89f69 | 1723 | clk_prepare_unlock(); |
b2476490 MT |
1724 | |
1725 | return ret; | |
1726 | } | |
1727 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1728 | ||
1729 | /** | |
1730 | * __clk_init - initialize the data structures in a struct clk | |
1731 | * @dev: device initializing this clk, placeholder for now | |
1732 | * @clk: clk being initialized | |
1733 | * | |
1734 | * Initializes the lists in struct clk, queries the hardware for the | |
1735 | * parent and rate and sets them both. | |
b2476490 | 1736 | */ |
d1302a36 | 1737 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1738 | { |
d1302a36 | 1739 | int i, ret = 0; |
b2476490 | 1740 | struct clk *orphan; |
b67bfe0d | 1741 | struct hlist_node *tmp2; |
b2476490 MT |
1742 | |
1743 | if (!clk) | |
d1302a36 | 1744 | return -EINVAL; |
b2476490 | 1745 | |
eab89f69 | 1746 | clk_prepare_lock(); |
b2476490 MT |
1747 | |
1748 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1749 | if (__clk_lookup(clk->name)) { |
1750 | pr_debug("%s: clk %s already initialized\n", | |
1751 | __func__, clk->name); | |
1752 | ret = -EEXIST; | |
b2476490 | 1753 | goto out; |
d1302a36 | 1754 | } |
b2476490 | 1755 | |
d4d7e3dd MT |
1756 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1757 | if (clk->ops->set_rate && | |
71472c0c JH |
1758 | !((clk->ops->round_rate || clk->ops->determine_rate) && |
1759 | clk->ops->recalc_rate)) { | |
1760 | pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", | |
d4d7e3dd | 1761 | __func__, clk->name); |
d1302a36 | 1762 | ret = -EINVAL; |
d4d7e3dd MT |
1763 | goto out; |
1764 | } | |
1765 | ||
1766 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1767 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1768 | __func__, clk->name); | |
d1302a36 | 1769 | ret = -EINVAL; |
d4d7e3dd MT |
1770 | goto out; |
1771 | } | |
1772 | ||
b2476490 MT |
1773 | /* throw a WARN if any entries in parent_names are NULL */ |
1774 | for (i = 0; i < clk->num_parents; i++) | |
1775 | WARN(!clk->parent_names[i], | |
1776 | "%s: invalid NULL in %s's .parent_names\n", | |
1777 | __func__, clk->name); | |
1778 | ||
1779 | /* | |
1780 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1781 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1782 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1783 | * must always check for a NULL pointer and try to populate it if | |
1784 | * necessary. | |
1785 | * | |
1786 | * If clk->parents is not NULL we skip this entire block. This allows | |
1787 | * for clock drivers to statically initialize clk->parents. | |
1788 | */ | |
9ca1c5a4 | 1789 | if (clk->num_parents > 1 && !clk->parents) { |
96a7ed90 TF |
1790 | clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *), |
1791 | GFP_KERNEL); | |
b2476490 MT |
1792 | /* |
1793 | * __clk_lookup returns NULL for parents that have not been | |
1794 | * clk_init'd; thus any access to clk->parents[] must check | |
1795 | * for a NULL pointer. We can always perform lazy lookups for | |
1796 | * missing parents later on. | |
1797 | */ | |
1798 | if (clk->parents) | |
1799 | for (i = 0; i < clk->num_parents; i++) | |
1800 | clk->parents[i] = | |
1801 | __clk_lookup(clk->parent_names[i]); | |
1802 | } | |
1803 | ||
1804 | clk->parent = __clk_init_parent(clk); | |
1805 | ||
1806 | /* | |
1807 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1808 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1809 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1810 | * clk list. | |
1811 | * | |
1812 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1813 | * clocks and re-parent any that are children of the clock currently | |
1814 | * being clk_init'd. | |
1815 | */ | |
1816 | if (clk->parent) | |
1817 | hlist_add_head(&clk->child_node, | |
1818 | &clk->parent->children); | |
1819 | else if (clk->flags & CLK_IS_ROOT) | |
1820 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1821 | else | |
1822 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1823 | ||
5279fc40 BB |
1824 | /* |
1825 | * Set clk's accuracy. The preferred method is to use | |
1826 | * .recalc_accuracy. For simple clocks and lazy developers the default | |
1827 | * fallback is to use the parent's accuracy. If a clock doesn't have a | |
1828 | * parent (or is orphaned) then accuracy is set to zero (perfect | |
1829 | * clock). | |
1830 | */ | |
1831 | if (clk->ops->recalc_accuracy) | |
1832 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1833 | __clk_get_accuracy(clk->parent)); | |
1834 | else if (clk->parent) | |
1835 | clk->accuracy = clk->parent->accuracy; | |
1836 | else | |
1837 | clk->accuracy = 0; | |
1838 | ||
b2476490 MT |
1839 | /* |
1840 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1841 | * simple clocks and lazy developers the default fallback is to use the | |
1842 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1843 | * then rate is set to zero. | |
1844 | */ | |
1845 | if (clk->ops->recalc_rate) | |
1846 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1847 | __clk_get_rate(clk->parent)); | |
1848 | else if (clk->parent) | |
1849 | clk->rate = clk->parent->rate; | |
1850 | else | |
1851 | clk->rate = 0; | |
1852 | ||
3a5aec24 | 1853 | clk_debug_register(clk); |
b2476490 MT |
1854 | /* |
1855 | * walk the list of orphan clocks and reparent any that are children of | |
1856 | * this clock | |
1857 | */ | |
b67bfe0d | 1858 | hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { |
12d29886 | 1859 | if (orphan->num_parents && orphan->ops->get_parent) { |
1f61e5f1 MF |
1860 | i = orphan->ops->get_parent(orphan->hw); |
1861 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1862 | __clk_reparent(orphan, clk); | |
1863 | continue; | |
1864 | } | |
1865 | ||
b2476490 MT |
1866 | for (i = 0; i < orphan->num_parents; i++) |
1867 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1868 | __clk_reparent(orphan, clk); | |
1869 | break; | |
1870 | } | |
1f61e5f1 | 1871 | } |
b2476490 MT |
1872 | |
1873 | /* | |
1874 | * optional platform-specific magic | |
1875 | * | |
1876 | * The .init callback is not used by any of the basic clock types, but | |
1877 | * exists for weird hardware that must perform initialization magic. | |
1878 | * Please consider other ways of solving initialization problems before | |
24ee1a08 | 1879 | * using this callback, as its use is discouraged. |
b2476490 MT |
1880 | */ |
1881 | if (clk->ops->init) | |
1882 | clk->ops->init(clk->hw); | |
1883 | ||
fcb0ee6a | 1884 | kref_init(&clk->ref); |
b2476490 | 1885 | out: |
eab89f69 | 1886 | clk_prepare_unlock(); |
b2476490 | 1887 | |
d1302a36 | 1888 | return ret; |
b2476490 MT |
1889 | } |
1890 | ||
0197b3ea SK |
1891 | /** |
1892 | * __clk_register - register a clock and return a cookie. | |
1893 | * | |
1894 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1895 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1896 | * of the struct clk need to be initialized. | |
1897 | * | |
1898 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1899 | * data. | |
1900 | * | |
1901 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1902 | * very large numbers of clocks that need to be statically initialized. It is | |
1903 | * a layering violation to include clk-private.h from any code which implements | |
1904 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
24ee1a08 | 1905 | * separate C file from the logic that implements its operations. Returns 0 |
0197b3ea SK |
1906 | * on success, otherwise an error code. |
1907 | */ | |
1908 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
1909 | { | |
1910 | int ret; | |
1911 | struct clk *clk; | |
1912 | ||
1913 | clk = hw->clk; | |
1914 | clk->name = hw->init->name; | |
1915 | clk->ops = hw->init->ops; | |
1916 | clk->hw = hw; | |
1917 | clk->flags = hw->init->flags; | |
1918 | clk->parent_names = hw->init->parent_names; | |
1919 | clk->num_parents = hw->init->num_parents; | |
ac2df527 SN |
1920 | if (dev && dev->driver) |
1921 | clk->owner = dev->driver->owner; | |
1922 | else | |
1923 | clk->owner = NULL; | |
0197b3ea SK |
1924 | |
1925 | ret = __clk_init(dev, clk); | |
1926 | if (ret) | |
1927 | return ERR_PTR(ret); | |
1928 | ||
1929 | return clk; | |
1930 | } | |
1931 | EXPORT_SYMBOL_GPL(__clk_register); | |
1932 | ||
46c8773a | 1933 | static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk) |
b2476490 | 1934 | { |
d1302a36 | 1935 | int i, ret; |
b2476490 | 1936 | |
0197b3ea SK |
1937 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
1938 | if (!clk->name) { | |
1939 | pr_err("%s: could not allocate clk->name\n", __func__); | |
1940 | ret = -ENOMEM; | |
1941 | goto fail_name; | |
1942 | } | |
1943 | clk->ops = hw->init->ops; | |
ac2df527 SN |
1944 | if (dev && dev->driver) |
1945 | clk->owner = dev->driver->owner; | |
b2476490 | 1946 | clk->hw = hw; |
0197b3ea SK |
1947 | clk->flags = hw->init->flags; |
1948 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
1949 | hw->clk = clk; |
1950 | ||
d1302a36 | 1951 | /* allocate local copy in case parent_names is __initdata */ |
96a7ed90 TF |
1952 | clk->parent_names = kcalloc(clk->num_parents, sizeof(char *), |
1953 | GFP_KERNEL); | |
d1302a36 MT |
1954 | |
1955 | if (!clk->parent_names) { | |
1956 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
1957 | ret = -ENOMEM; | |
1958 | goto fail_parent_names; | |
1959 | } | |
1960 | ||
1961 | ||
1962 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea SK |
1963 | for (i = 0; i < clk->num_parents; i++) { |
1964 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], | |
1965 | GFP_KERNEL); | |
d1302a36 MT |
1966 | if (!clk->parent_names[i]) { |
1967 | pr_err("%s: could not copy parent_names\n", __func__); | |
1968 | ret = -ENOMEM; | |
1969 | goto fail_parent_names_copy; | |
1970 | } | |
1971 | } | |
1972 | ||
1973 | ret = __clk_init(dev, clk); | |
1974 | if (!ret) | |
46c8773a | 1975 | return 0; |
b2476490 | 1976 | |
d1302a36 MT |
1977 | fail_parent_names_copy: |
1978 | while (--i >= 0) | |
1979 | kfree(clk->parent_names[i]); | |
1980 | kfree(clk->parent_names); | |
1981 | fail_parent_names: | |
0197b3ea SK |
1982 | kfree(clk->name); |
1983 | fail_name: | |
46c8773a SB |
1984 | return ret; |
1985 | } | |
1986 | ||
1987 | /** | |
1988 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
1989 | * @dev: device that is registering this clock | |
1990 | * @hw: link to hardware-specific clock data | |
1991 | * | |
1992 | * clk_register is the primary interface for populating the clock tree with new | |
1993 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
1994 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
1995 | * rest of the clock API. In the event of an error clk_register will return an | |
1996 | * error code; drivers must test for an error code after calling clk_register. | |
1997 | */ | |
1998 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
1999 | { | |
2000 | int ret; | |
2001 | struct clk *clk; | |
2002 | ||
2003 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
2004 | if (!clk) { | |
2005 | pr_err("%s: could not allocate clk\n", __func__); | |
2006 | ret = -ENOMEM; | |
2007 | goto fail_out; | |
2008 | } | |
2009 | ||
2010 | ret = _clk_register(dev, hw, clk); | |
2011 | if (!ret) | |
2012 | return clk; | |
2013 | ||
d1302a36 MT |
2014 | kfree(clk); |
2015 | fail_out: | |
2016 | return ERR_PTR(ret); | |
b2476490 MT |
2017 | } |
2018 | EXPORT_SYMBOL_GPL(clk_register); | |
2019 | ||
fcb0ee6a SN |
2020 | /* |
2021 | * Free memory allocated for a clock. | |
2022 | * Caller must hold prepare_lock. | |
2023 | */ | |
2024 | static void __clk_release(struct kref *ref) | |
2025 | { | |
2026 | struct clk *clk = container_of(ref, struct clk, ref); | |
2027 | int i = clk->num_parents; | |
2028 | ||
2029 | kfree(clk->parents); | |
2030 | while (--i >= 0) | |
2031 | kfree(clk->parent_names[i]); | |
2032 | ||
2033 | kfree(clk->parent_names); | |
2034 | kfree(clk->name); | |
2035 | kfree(clk); | |
2036 | } | |
2037 | ||
2038 | /* | |
2039 | * Empty clk_ops for unregistered clocks. These are used temporarily | |
2040 | * after clk_unregister() was called on a clock and until last clock | |
2041 | * consumer calls clk_put() and the struct clk object is freed. | |
2042 | */ | |
2043 | static int clk_nodrv_prepare_enable(struct clk_hw *hw) | |
2044 | { | |
2045 | return -ENXIO; | |
2046 | } | |
2047 | ||
2048 | static void clk_nodrv_disable_unprepare(struct clk_hw *hw) | |
2049 | { | |
2050 | WARN_ON_ONCE(1); | |
2051 | } | |
2052 | ||
2053 | static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, | |
2054 | unsigned long parent_rate) | |
2055 | { | |
2056 | return -ENXIO; | |
2057 | } | |
2058 | ||
2059 | static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) | |
2060 | { | |
2061 | return -ENXIO; | |
2062 | } | |
2063 | ||
2064 | static const struct clk_ops clk_nodrv_ops = { | |
2065 | .enable = clk_nodrv_prepare_enable, | |
2066 | .disable = clk_nodrv_disable_unprepare, | |
2067 | .prepare = clk_nodrv_prepare_enable, | |
2068 | .unprepare = clk_nodrv_disable_unprepare, | |
2069 | .set_rate = clk_nodrv_set_rate, | |
2070 | .set_parent = clk_nodrv_set_parent, | |
2071 | }; | |
2072 | ||
1df5c939 MB |
2073 | /** |
2074 | * clk_unregister - unregister a currently registered clock | |
2075 | * @clk: clock to unregister | |
1df5c939 | 2076 | */ |
fcb0ee6a SN |
2077 | void clk_unregister(struct clk *clk) |
2078 | { | |
2079 | unsigned long flags; | |
2080 | ||
2081 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) | |
2082 | return; | |
2083 | ||
2084 | clk_prepare_lock(); | |
2085 | ||
2086 | if (clk->ops == &clk_nodrv_ops) { | |
2087 | pr_err("%s: unregistered clock: %s\n", __func__, clk->name); | |
2088 | goto out; | |
2089 | } | |
2090 | /* | |
2091 | * Assign empty clock ops for consumers that might still hold | |
2092 | * a reference to this clock. | |
2093 | */ | |
2094 | flags = clk_enable_lock(); | |
2095 | clk->ops = &clk_nodrv_ops; | |
2096 | clk_enable_unlock(flags); | |
2097 | ||
2098 | if (!hlist_empty(&clk->children)) { | |
2099 | struct clk *child; | |
2100 | ||
2101 | /* Reparent all children to the orphan list. */ | |
2102 | hlist_for_each_entry(child, &clk->children, child_node) | |
2103 | clk_set_parent(child, NULL); | |
2104 | } | |
2105 | ||
2106 | clk_debug_unregister(clk); | |
2107 | ||
2108 | hlist_del_init(&clk->child_node); | |
2109 | ||
2110 | if (clk->prepare_count) | |
2111 | pr_warn("%s: unregistering prepared clock: %s\n", | |
2112 | __func__, clk->name); | |
2113 | ||
2114 | kref_put(&clk->ref, __clk_release); | |
2115 | out: | |
2116 | clk_prepare_unlock(); | |
2117 | } | |
1df5c939 MB |
2118 | EXPORT_SYMBOL_GPL(clk_unregister); |
2119 | ||
46c8773a SB |
2120 | static void devm_clk_release(struct device *dev, void *res) |
2121 | { | |
2122 | clk_unregister(res); | |
2123 | } | |
2124 | ||
2125 | /** | |
2126 | * devm_clk_register - resource managed clk_register() | |
2127 | * @dev: device that is registering this clock | |
2128 | * @hw: link to hardware-specific clock data | |
2129 | * | |
2130 | * Managed clk_register(). Clocks returned from this function are | |
2131 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
2132 | * more information. | |
2133 | */ | |
2134 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
2135 | { | |
2136 | struct clk *clk; | |
2137 | int ret; | |
2138 | ||
2139 | clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL); | |
2140 | if (!clk) | |
2141 | return ERR_PTR(-ENOMEM); | |
2142 | ||
2143 | ret = _clk_register(dev, hw, clk); | |
2144 | if (!ret) { | |
2145 | devres_add(dev, clk); | |
2146 | } else { | |
2147 | devres_free(clk); | |
2148 | clk = ERR_PTR(ret); | |
2149 | } | |
2150 | ||
2151 | return clk; | |
2152 | } | |
2153 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
2154 | ||
2155 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
2156 | { | |
2157 | struct clk *c = res; | |
2158 | if (WARN_ON(!c)) | |
2159 | return 0; | |
2160 | return c == data; | |
2161 | } | |
2162 | ||
2163 | /** | |
2164 | * devm_clk_unregister - resource managed clk_unregister() | |
2165 | * @clk: clock to unregister | |
2166 | * | |
2167 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
2168 | * this function will not need to be called and the resource management | |
2169 | * code will ensure that the resource is freed. | |
2170 | */ | |
2171 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
2172 | { | |
2173 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
2174 | } | |
2175 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
2176 | ||
ac2df527 SN |
2177 | /* |
2178 | * clkdev helpers | |
2179 | */ | |
2180 | int __clk_get(struct clk *clk) | |
2181 | { | |
2182 | if (clk && !try_module_get(clk->owner)) | |
2183 | return 0; | |
2184 | ||
fcb0ee6a | 2185 | kref_get(&clk->ref); |
ac2df527 SN |
2186 | return 1; |
2187 | } | |
2188 | ||
2189 | void __clk_put(struct clk *clk) | |
2190 | { | |
2191 | if (WARN_ON_ONCE(IS_ERR(clk))) | |
2192 | return; | |
2193 | ||
fcb0ee6a SN |
2194 | clk_prepare_lock(); |
2195 | kref_put(&clk->ref, __clk_release); | |
2196 | clk_prepare_unlock(); | |
2197 | ||
ac2df527 SN |
2198 | if (clk) |
2199 | module_put(clk->owner); | |
2200 | } | |
2201 | ||
b2476490 MT |
2202 | /*** clk rate change notifiers ***/ |
2203 | ||
2204 | /** | |
2205 | * clk_notifier_register - add a clk rate change notifier | |
2206 | * @clk: struct clk * to watch | |
2207 | * @nb: struct notifier_block * with callback info | |
2208 | * | |
2209 | * Request notification when clk's rate changes. This uses an SRCU | |
2210 | * notifier because we want it to block and notifier unregistrations are | |
2211 | * uncommon. The callbacks associated with the notifier must not | |
2212 | * re-enter into the clk framework by calling any top-level clk APIs; | |
2213 | * this will cause a nested prepare_lock mutex. | |
2214 | * | |
2215 | * Pre-change notifier callbacks will be passed the current, pre-change | |
2216 | * rate of the clk via struct clk_notifier_data.old_rate. The new, | |
2217 | * post-change rate of the clk is passed via struct | |
2218 | * clk_notifier_data.new_rate. | |
2219 | * | |
2220 | * Post-change notifiers will pass the now-current, post-change rate of | |
2221 | * the clk in both struct clk_notifier_data.old_rate and struct | |
2222 | * clk_notifier_data.new_rate. | |
2223 | * | |
2224 | * Abort-change notifiers are effectively the opposite of pre-change | |
2225 | * notifiers: the original pre-change clk rate is passed in via struct | |
2226 | * clk_notifier_data.new_rate and the failed post-change rate is passed | |
2227 | * in via struct clk_notifier_data.old_rate. | |
2228 | * | |
2229 | * clk_notifier_register() must be called from non-atomic context. | |
2230 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
2231 | * allocation failure; otherwise, passes along the return value of | |
2232 | * srcu_notifier_chain_register(). | |
2233 | */ | |
2234 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
2235 | { | |
2236 | struct clk_notifier *cn; | |
2237 | int ret = -ENOMEM; | |
2238 | ||
2239 | if (!clk || !nb) | |
2240 | return -EINVAL; | |
2241 | ||
eab89f69 | 2242 | clk_prepare_lock(); |
b2476490 MT |
2243 | |
2244 | /* search the list of notifiers for this clk */ | |
2245 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2246 | if (cn->clk == clk) | |
2247 | break; | |
2248 | ||
2249 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
2250 | if (cn->clk != clk) { | |
2251 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
2252 | if (!cn) | |
2253 | goto out; | |
2254 | ||
2255 | cn->clk = clk; | |
2256 | srcu_init_notifier_head(&cn->notifier_head); | |
2257 | ||
2258 | list_add(&cn->node, &clk_notifier_list); | |
2259 | } | |
2260 | ||
2261 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
2262 | ||
2263 | clk->notifier_count++; | |
2264 | ||
2265 | out: | |
eab89f69 | 2266 | clk_prepare_unlock(); |
b2476490 MT |
2267 | |
2268 | return ret; | |
2269 | } | |
2270 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
2271 | ||
2272 | /** | |
2273 | * clk_notifier_unregister - remove a clk rate change notifier | |
2274 | * @clk: struct clk * | |
2275 | * @nb: struct notifier_block * with callback info | |
2276 | * | |
2277 | * Request no further notification for changes to 'clk' and frees memory | |
2278 | * allocated in clk_notifier_register. | |
2279 | * | |
2280 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
2281 | * along the return value of srcu_notifier_chain_unregister(). | |
2282 | */ | |
2283 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
2284 | { | |
2285 | struct clk_notifier *cn = NULL; | |
2286 | int ret = -EINVAL; | |
2287 | ||
2288 | if (!clk || !nb) | |
2289 | return -EINVAL; | |
2290 | ||
eab89f69 | 2291 | clk_prepare_lock(); |
b2476490 MT |
2292 | |
2293 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2294 | if (cn->clk == clk) | |
2295 | break; | |
2296 | ||
2297 | if (cn->clk == clk) { | |
2298 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
2299 | ||
2300 | clk->notifier_count--; | |
2301 | ||
2302 | /* XXX the notifier code should handle this better */ | |
2303 | if (!cn->notifier_head.head) { | |
2304 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
72b5322f | 2305 | list_del(&cn->node); |
b2476490 MT |
2306 | kfree(cn); |
2307 | } | |
2308 | ||
2309 | } else { | |
2310 | ret = -ENOENT; | |
2311 | } | |
2312 | ||
eab89f69 | 2313 | clk_prepare_unlock(); |
b2476490 MT |
2314 | |
2315 | return ret; | |
2316 | } | |
2317 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
2318 | |
2319 | #ifdef CONFIG_OF | |
2320 | /** | |
2321 | * struct of_clk_provider - Clock provider registration structure | |
2322 | * @link: Entry in global list of clock providers | |
2323 | * @node: Pointer to device tree node of clock provider | |
2324 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
2325 | * given clock specifier | |
2326 | * @data: context pointer to be passed into @get callback | |
2327 | */ | |
2328 | struct of_clk_provider { | |
2329 | struct list_head link; | |
2330 | ||
2331 | struct device_node *node; | |
2332 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
2333 | void *data; | |
2334 | }; | |
2335 | ||
f2f6c255 PG |
2336 | extern struct of_device_id __clk_of_table[]; |
2337 | ||
2338 | static const struct of_device_id __clk_of_table_sentinel | |
2339 | __used __section(__clk_of_table_end); | |
2340 | ||
766e6a4e | 2341 | static LIST_HEAD(of_clk_providers); |
d6782c26 SN |
2342 | static DEFINE_MUTEX(of_clk_mutex); |
2343 | ||
2344 | /* of_clk_provider list locking helpers */ | |
2345 | void of_clk_lock(void) | |
2346 | { | |
2347 | mutex_lock(&of_clk_mutex); | |
2348 | } | |
2349 | ||
2350 | void of_clk_unlock(void) | |
2351 | { | |
2352 | mutex_unlock(&of_clk_mutex); | |
2353 | } | |
766e6a4e GL |
2354 | |
2355 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
2356 | void *data) | |
2357 | { | |
2358 | return data; | |
2359 | } | |
2360 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
2361 | ||
494bfec9 SG |
2362 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
2363 | { | |
2364 | struct clk_onecell_data *clk_data = data; | |
2365 | unsigned int idx = clkspec->args[0]; | |
2366 | ||
2367 | if (idx >= clk_data->clk_num) { | |
2368 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
2369 | return ERR_PTR(-EINVAL); | |
2370 | } | |
2371 | ||
2372 | return clk_data->clks[idx]; | |
2373 | } | |
2374 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
2375 | ||
766e6a4e GL |
2376 | /** |
2377 | * of_clk_add_provider() - Register a clock provider for a node | |
2378 | * @np: Device node pointer associated with clock provider | |
2379 | * @clk_src_get: callback for decoding clock | |
2380 | * @data: context pointer for @clk_src_get callback. | |
2381 | */ | |
2382 | int of_clk_add_provider(struct device_node *np, | |
2383 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
2384 | void *data), | |
2385 | void *data) | |
2386 | { | |
2387 | struct of_clk_provider *cp; | |
2388 | ||
2389 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
2390 | if (!cp) | |
2391 | return -ENOMEM; | |
2392 | ||
2393 | cp->node = of_node_get(np); | |
2394 | cp->data = data; | |
2395 | cp->get = clk_src_get; | |
2396 | ||
d6782c26 | 2397 | mutex_lock(&of_clk_mutex); |
766e6a4e | 2398 | list_add(&cp->link, &of_clk_providers); |
d6782c26 | 2399 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2400 | pr_debug("Added clock from %s\n", np->full_name); |
2401 | ||
2402 | return 0; | |
2403 | } | |
2404 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
2405 | ||
2406 | /** | |
2407 | * of_clk_del_provider() - Remove a previously registered clock provider | |
2408 | * @np: Device node pointer associated with clock provider | |
2409 | */ | |
2410 | void of_clk_del_provider(struct device_node *np) | |
2411 | { | |
2412 | struct of_clk_provider *cp; | |
2413 | ||
d6782c26 | 2414 | mutex_lock(&of_clk_mutex); |
766e6a4e GL |
2415 | list_for_each_entry(cp, &of_clk_providers, link) { |
2416 | if (cp->node == np) { | |
2417 | list_del(&cp->link); | |
2418 | of_node_put(cp->node); | |
2419 | kfree(cp); | |
2420 | break; | |
2421 | } | |
2422 | } | |
d6782c26 | 2423 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2424 | } |
2425 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
2426 | ||
d6782c26 | 2427 | struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) |
766e6a4e GL |
2428 | { |
2429 | struct of_clk_provider *provider; | |
2430 | struct clk *clk = ERR_PTR(-ENOENT); | |
2431 | ||
2432 | /* Check if we have such a provider in our array */ | |
766e6a4e GL |
2433 | list_for_each_entry(provider, &of_clk_providers, link) { |
2434 | if (provider->node == clkspec->np) | |
2435 | clk = provider->get(clkspec, provider->data); | |
2436 | if (!IS_ERR(clk)) | |
2437 | break; | |
2438 | } | |
d6782c26 SN |
2439 | |
2440 | return clk; | |
2441 | } | |
2442 | ||
2443 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
2444 | { | |
2445 | struct clk *clk; | |
2446 | ||
2447 | mutex_lock(&of_clk_mutex); | |
2448 | clk = __of_clk_get_from_provider(clkspec); | |
2449 | mutex_unlock(&of_clk_mutex); | |
766e6a4e GL |
2450 | |
2451 | return clk; | |
2452 | } | |
2453 | ||
f6102742 MT |
2454 | int of_clk_get_parent_count(struct device_node *np) |
2455 | { | |
2456 | return of_count_phandle_with_args(np, "clocks", "#clock-cells"); | |
2457 | } | |
2458 | EXPORT_SYMBOL_GPL(of_clk_get_parent_count); | |
2459 | ||
766e6a4e GL |
2460 | const char *of_clk_get_parent_name(struct device_node *np, int index) |
2461 | { | |
2462 | struct of_phandle_args clkspec; | |
2463 | const char *clk_name; | |
2464 | int rc; | |
2465 | ||
2466 | if (index < 0) | |
2467 | return NULL; | |
2468 | ||
2469 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
2470 | &clkspec); | |
2471 | if (rc) | |
2472 | return NULL; | |
2473 | ||
2474 | if (of_property_read_string_index(clkspec.np, "clock-output-names", | |
2475 | clkspec.args_count ? clkspec.args[0] : 0, | |
2476 | &clk_name) < 0) | |
2477 | clk_name = clkspec.np->name; | |
2478 | ||
2479 | of_node_put(clkspec.np); | |
2480 | return clk_name; | |
2481 | } | |
2482 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
2483 | ||
2484 | /** | |
2485 | * of_clk_init() - Scan and init clock providers from the DT | |
2486 | * @matches: array of compatible values and init functions for providers. | |
2487 | * | |
2488 | * This function scans the device tree for matching clock providers and | |
2489 | * calls their initialization functions | |
2490 | */ | |
2491 | void __init of_clk_init(const struct of_device_id *matches) | |
2492 | { | |
7f7ed584 | 2493 | const struct of_device_id *match; |
766e6a4e GL |
2494 | struct device_node *np; |
2495 | ||
f2f6c255 PG |
2496 | if (!matches) |
2497 | matches = __clk_of_table; | |
2498 | ||
7f7ed584 | 2499 | for_each_matching_node_and_match(np, matches, &match) { |
766e6a4e GL |
2500 | of_clk_init_cb_t clk_init_cb = match->data; |
2501 | clk_init_cb(np); | |
2502 | } | |
2503 | } | |
2504 | #endif |