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