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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 | ||
27b8d5f7 PDS |
39 | static struct hlist_head *all_lists[] = { |
40 | &clk_root_list, | |
41 | &clk_orphan_list, | |
42 | NULL, | |
43 | }; | |
44 | ||
45 | static struct hlist_head *orphan_list[] = { | |
46 | &clk_orphan_list, | |
47 | NULL, | |
48 | }; | |
49 | ||
eab89f69 MT |
50 | /*** locking ***/ |
51 | static void clk_prepare_lock(void) | |
52 | { | |
533ddeb1 MT |
53 | if (!mutex_trylock(&prepare_lock)) { |
54 | if (prepare_owner == current) { | |
55 | prepare_refcnt++; | |
56 | return; | |
57 | } | |
58 | mutex_lock(&prepare_lock); | |
59 | } | |
60 | WARN_ON_ONCE(prepare_owner != NULL); | |
61 | WARN_ON_ONCE(prepare_refcnt != 0); | |
62 | prepare_owner = current; | |
63 | prepare_refcnt = 1; | |
eab89f69 MT |
64 | } |
65 | ||
66 | static void clk_prepare_unlock(void) | |
67 | { | |
533ddeb1 MT |
68 | WARN_ON_ONCE(prepare_owner != current); |
69 | WARN_ON_ONCE(prepare_refcnt == 0); | |
70 | ||
71 | if (--prepare_refcnt) | |
72 | return; | |
73 | prepare_owner = NULL; | |
eab89f69 MT |
74 | mutex_unlock(&prepare_lock); |
75 | } | |
76 | ||
77 | static unsigned long clk_enable_lock(void) | |
78 | { | |
79 | unsigned long flags; | |
533ddeb1 MT |
80 | |
81 | if (!spin_trylock_irqsave(&enable_lock, flags)) { | |
82 | if (enable_owner == current) { | |
83 | enable_refcnt++; | |
84 | return flags; | |
85 | } | |
86 | spin_lock_irqsave(&enable_lock, flags); | |
87 | } | |
88 | WARN_ON_ONCE(enable_owner != NULL); | |
89 | WARN_ON_ONCE(enable_refcnt != 0); | |
90 | enable_owner = current; | |
91 | enable_refcnt = 1; | |
eab89f69 MT |
92 | return flags; |
93 | } | |
94 | ||
95 | static void clk_enable_unlock(unsigned long flags) | |
96 | { | |
533ddeb1 MT |
97 | WARN_ON_ONCE(enable_owner != current); |
98 | WARN_ON_ONCE(enable_refcnt == 0); | |
99 | ||
100 | if (--enable_refcnt) | |
101 | return; | |
102 | enable_owner = NULL; | |
eab89f69 MT |
103 | spin_unlock_irqrestore(&enable_lock, flags); |
104 | } | |
105 | ||
b2476490 MT |
106 | /*** debugfs support ***/ |
107 | ||
ea72dc2c | 108 | #ifdef CONFIG_DEBUG_FS |
b2476490 MT |
109 | #include <linux/debugfs.h> |
110 | ||
111 | static struct dentry *rootdir; | |
b2476490 MT |
112 | static int inited = 0; |
113 | ||
1af599df PG |
114 | static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level) |
115 | { | |
116 | if (!c) | |
117 | return; | |
118 | ||
fb8abb7a | 119 | seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu\n", |
1af599df PG |
120 | level * 3 + 1, "", |
121 | 30 - level * 3, c->name, | |
5279fc40 BB |
122 | c->enable_count, c->prepare_count, clk_get_rate(c), |
123 | clk_get_accuracy(c)); | |
1af599df PG |
124 | } |
125 | ||
126 | static void clk_summary_show_subtree(struct seq_file *s, struct clk *c, | |
127 | int level) | |
128 | { | |
129 | struct clk *child; | |
1af599df PG |
130 | |
131 | if (!c) | |
132 | return; | |
133 | ||
134 | clk_summary_show_one(s, c, level); | |
135 | ||
b67bfe0d | 136 | hlist_for_each_entry(child, &c->children, child_node) |
1af599df PG |
137 | clk_summary_show_subtree(s, child, level + 1); |
138 | } | |
139 | ||
140 | static int clk_summary_show(struct seq_file *s, void *data) | |
141 | { | |
142 | struct clk *c; | |
27b8d5f7 | 143 | struct hlist_head **lists = (struct hlist_head **)s->private; |
1af599df | 144 | |
fb8abb7a GU |
145 | seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy\n"); |
146 | seq_puts(s, "--------------------------------------------------------------------------------\n"); | |
1af599df | 147 | |
eab89f69 | 148 | clk_prepare_lock(); |
1af599df | 149 | |
27b8d5f7 PDS |
150 | for (; *lists; lists++) |
151 | hlist_for_each_entry(c, *lists, child_node) | |
152 | clk_summary_show_subtree(s, c, 0); | |
1af599df | 153 | |
eab89f69 | 154 | clk_prepare_unlock(); |
1af599df PG |
155 | |
156 | return 0; | |
157 | } | |
158 | ||
159 | ||
160 | static int clk_summary_open(struct inode *inode, struct file *file) | |
161 | { | |
162 | return single_open(file, clk_summary_show, inode->i_private); | |
163 | } | |
164 | ||
165 | static const struct file_operations clk_summary_fops = { | |
166 | .open = clk_summary_open, | |
167 | .read = seq_read, | |
168 | .llseek = seq_lseek, | |
169 | .release = single_release, | |
170 | }; | |
171 | ||
bddca894 PG |
172 | static void clk_dump_one(struct seq_file *s, struct clk *c, int level) |
173 | { | |
174 | if (!c) | |
175 | return; | |
176 | ||
177 | seq_printf(s, "\"%s\": { ", c->name); | |
178 | seq_printf(s, "\"enable_count\": %d,", c->enable_count); | |
179 | seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); | |
670decdd | 180 | seq_printf(s, "\"rate\": %lu", clk_get_rate(c)); |
5279fc40 | 181 | seq_printf(s, "\"accuracy\": %lu", clk_get_accuracy(c)); |
bddca894 PG |
182 | } |
183 | ||
184 | static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) | |
185 | { | |
186 | struct clk *child; | |
bddca894 PG |
187 | |
188 | if (!c) | |
189 | return; | |
190 | ||
191 | clk_dump_one(s, c, level); | |
192 | ||
b67bfe0d | 193 | hlist_for_each_entry(child, &c->children, child_node) { |
bddca894 PG |
194 | seq_printf(s, ","); |
195 | clk_dump_subtree(s, child, level + 1); | |
196 | } | |
197 | ||
198 | seq_printf(s, "}"); | |
199 | } | |
200 | ||
201 | static int clk_dump(struct seq_file *s, void *data) | |
202 | { | |
203 | struct clk *c; | |
bddca894 | 204 | bool first_node = true; |
27b8d5f7 | 205 | struct hlist_head **lists = (struct hlist_head **)s->private; |
bddca894 PG |
206 | |
207 | seq_printf(s, "{"); | |
208 | ||
eab89f69 | 209 | clk_prepare_lock(); |
bddca894 | 210 | |
27b8d5f7 PDS |
211 | for (; *lists; lists++) { |
212 | hlist_for_each_entry(c, *lists, child_node) { | |
213 | if (!first_node) | |
214 | seq_puts(s, ","); | |
215 | first_node = false; | |
216 | clk_dump_subtree(s, c, 0); | |
217 | } | |
bddca894 PG |
218 | } |
219 | ||
eab89f69 | 220 | clk_prepare_unlock(); |
bddca894 PG |
221 | |
222 | seq_printf(s, "}"); | |
223 | return 0; | |
224 | } | |
225 | ||
226 | ||
227 | static int clk_dump_open(struct inode *inode, struct file *file) | |
228 | { | |
229 | return single_open(file, clk_dump, inode->i_private); | |
230 | } | |
231 | ||
232 | static const struct file_operations clk_dump_fops = { | |
233 | .open = clk_dump_open, | |
234 | .read = seq_read, | |
235 | .llseek = seq_lseek, | |
236 | .release = single_release, | |
237 | }; | |
238 | ||
b2476490 MT |
239 | /* caller must hold prepare_lock */ |
240 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) | |
241 | { | |
242 | struct dentry *d; | |
243 | int ret = -ENOMEM; | |
244 | ||
245 | if (!clk || !pdentry) { | |
246 | ret = -EINVAL; | |
247 | goto out; | |
248 | } | |
249 | ||
250 | d = debugfs_create_dir(clk->name, pdentry); | |
251 | if (!d) | |
252 | goto out; | |
253 | ||
254 | clk->dentry = d; | |
255 | ||
256 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, | |
257 | (u32 *)&clk->rate); | |
258 | if (!d) | |
259 | goto err_out; | |
260 | ||
5279fc40 BB |
261 | d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry, |
262 | (u32 *)&clk->accuracy); | |
263 | if (!d) | |
264 | goto err_out; | |
265 | ||
b2476490 MT |
266 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, |
267 | (u32 *)&clk->flags); | |
268 | if (!d) | |
269 | goto err_out; | |
270 | ||
271 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, | |
272 | (u32 *)&clk->prepare_count); | |
273 | if (!d) | |
274 | goto err_out; | |
275 | ||
276 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, | |
277 | (u32 *)&clk->enable_count); | |
278 | if (!d) | |
279 | goto err_out; | |
280 | ||
281 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, | |
282 | (u32 *)&clk->notifier_count); | |
283 | if (!d) | |
284 | goto err_out; | |
285 | ||
c646cbf1 AE |
286 | if (clk->ops->debug_init) |
287 | if (clk->ops->debug_init(clk->hw, clk->dentry)) | |
288 | goto err_out; | |
289 | ||
b2476490 MT |
290 | ret = 0; |
291 | goto out; | |
292 | ||
293 | err_out: | |
b5f98e65 AE |
294 | debugfs_remove_recursive(clk->dentry); |
295 | clk->dentry = NULL; | |
b2476490 MT |
296 | out: |
297 | return ret; | |
298 | } | |
299 | ||
300 | /* caller must hold prepare_lock */ | |
301 | static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry) | |
302 | { | |
303 | struct clk *child; | |
b2476490 MT |
304 | int ret = -EINVAL;; |
305 | ||
306 | if (!clk || !pdentry) | |
307 | goto out; | |
308 | ||
309 | ret = clk_debug_create_one(clk, pdentry); | |
310 | ||
311 | if (ret) | |
312 | goto out; | |
313 | ||
b67bfe0d | 314 | hlist_for_each_entry(child, &clk->children, child_node) |
27b8d5f7 | 315 | clk_debug_create_subtree(child, pdentry); |
b2476490 MT |
316 | |
317 | ret = 0; | |
318 | out: | |
319 | return ret; | |
320 | } | |
321 | ||
322 | /** | |
323 | * clk_debug_register - add a clk node to the debugfs clk tree | |
324 | * @clk: the clk being added to the debugfs clk tree | |
325 | * | |
326 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been | |
327 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
328 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
329 | * | |
330 | * Caller must hold prepare_lock. Only clk_init calls this function (so | |
331 | * far) so this is taken care. | |
332 | */ | |
333 | static int clk_debug_register(struct clk *clk) | |
334 | { | |
b2476490 MT |
335 | int ret = 0; |
336 | ||
337 | if (!inited) | |
338 | goto out; | |
339 | ||
27b8d5f7 | 340 | ret = clk_debug_create_subtree(clk, rootdir); |
b2476490 MT |
341 | |
342 | out: | |
343 | return ret; | |
344 | } | |
345 | ||
fcb0ee6a SN |
346 | /** |
347 | * clk_debug_unregister - remove a clk node from the debugfs clk tree | |
348 | * @clk: the clk being removed from the debugfs clk tree | |
349 | * | |
350 | * Dynamically removes a clk and all it's children clk nodes from the | |
351 | * debugfs clk tree if clk->dentry points to debugfs created by | |
352 | * clk_debug_register in __clk_init. | |
353 | * | |
354 | * Caller must hold prepare_lock. | |
355 | */ | |
356 | static void clk_debug_unregister(struct clk *clk) | |
357 | { | |
358 | debugfs_remove_recursive(clk->dentry); | |
359 | } | |
360 | ||
b2476490 MT |
361 | /** |
362 | * clk_debug_init - lazily create the debugfs clk tree visualization | |
363 | * | |
364 | * clks are often initialized very early during boot before memory can | |
365 | * be dynamically allocated and well before debugfs is setup. | |
366 | * clk_debug_init walks the clk tree hierarchy while holding | |
367 | * prepare_lock and creates the topology as part of a late_initcall, | |
368 | * thus insuring that clks initialized very early will still be | |
369 | * represented in the debugfs clk tree. This function should only be | |
370 | * called once at boot-time, and all other clks added dynamically will | |
371 | * be done so with clk_debug_register. | |
372 | */ | |
373 | static int __init clk_debug_init(void) | |
374 | { | |
375 | struct clk *clk; | |
1af599df | 376 | struct dentry *d; |
b2476490 MT |
377 | |
378 | rootdir = debugfs_create_dir("clk", NULL); | |
379 | ||
380 | if (!rootdir) | |
381 | return -ENOMEM; | |
382 | ||
27b8d5f7 | 383 | d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists, |
1af599df PG |
384 | &clk_summary_fops); |
385 | if (!d) | |
386 | return -ENOMEM; | |
387 | ||
27b8d5f7 | 388 | d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists, |
bddca894 PG |
389 | &clk_dump_fops); |
390 | if (!d) | |
391 | return -ENOMEM; | |
392 | ||
27b8d5f7 PDS |
393 | d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir, |
394 | &orphan_list, &clk_summary_fops); | |
395 | if (!d) | |
396 | return -ENOMEM; | |
b2476490 | 397 | |
27b8d5f7 PDS |
398 | d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir, |
399 | &orphan_list, &clk_dump_fops); | |
400 | if (!d) | |
b2476490 MT |
401 | return -ENOMEM; |
402 | ||
eab89f69 | 403 | clk_prepare_lock(); |
b2476490 | 404 | |
b67bfe0d | 405 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
406 | clk_debug_create_subtree(clk, rootdir); |
407 | ||
b67bfe0d | 408 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
27b8d5f7 | 409 | clk_debug_create_subtree(clk, rootdir); |
b2476490 MT |
410 | |
411 | inited = 1; | |
412 | ||
eab89f69 | 413 | clk_prepare_unlock(); |
b2476490 MT |
414 | |
415 | return 0; | |
416 | } | |
417 | late_initcall(clk_debug_init); | |
418 | #else | |
419 | static inline int clk_debug_register(struct clk *clk) { return 0; } | |
b33d212f UH |
420 | static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent) |
421 | { | |
422 | } | |
fcb0ee6a SN |
423 | static inline void clk_debug_unregister(struct clk *clk) |
424 | { | |
425 | } | |
70d347e6 | 426 | #endif |
b2476490 | 427 | |
1c155b3d UH |
428 | /* caller must hold prepare_lock */ |
429 | static void clk_unprepare_unused_subtree(struct clk *clk) | |
430 | { | |
431 | struct clk *child; | |
432 | ||
433 | if (!clk) | |
434 | return; | |
435 | ||
436 | hlist_for_each_entry(child, &clk->children, child_node) | |
437 | clk_unprepare_unused_subtree(child); | |
438 | ||
439 | if (clk->prepare_count) | |
440 | return; | |
441 | ||
442 | if (clk->flags & CLK_IGNORE_UNUSED) | |
443 | return; | |
444 | ||
3cc8247f UH |
445 | if (__clk_is_prepared(clk)) { |
446 | if (clk->ops->unprepare_unused) | |
447 | clk->ops->unprepare_unused(clk->hw); | |
448 | else if (clk->ops->unprepare) | |
1c155b3d | 449 | clk->ops->unprepare(clk->hw); |
3cc8247f | 450 | } |
1c155b3d UH |
451 | } |
452 | ||
b2476490 MT |
453 | /* caller must hold prepare_lock */ |
454 | static void clk_disable_unused_subtree(struct clk *clk) | |
455 | { | |
456 | struct clk *child; | |
b2476490 MT |
457 | unsigned long flags; |
458 | ||
459 | if (!clk) | |
460 | goto out; | |
461 | ||
b67bfe0d | 462 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
463 | clk_disable_unused_subtree(child); |
464 | ||
eab89f69 | 465 | flags = clk_enable_lock(); |
b2476490 MT |
466 | |
467 | if (clk->enable_count) | |
468 | goto unlock_out; | |
469 | ||
470 | if (clk->flags & CLK_IGNORE_UNUSED) | |
471 | goto unlock_out; | |
472 | ||
7c045a55 MT |
473 | /* |
474 | * some gate clocks have special needs during the disable-unused | |
475 | * sequence. call .disable_unused if available, otherwise fall | |
476 | * back to .disable | |
477 | */ | |
478 | if (__clk_is_enabled(clk)) { | |
479 | if (clk->ops->disable_unused) | |
480 | clk->ops->disable_unused(clk->hw); | |
481 | else if (clk->ops->disable) | |
482 | clk->ops->disable(clk->hw); | |
483 | } | |
b2476490 MT |
484 | |
485 | unlock_out: | |
eab89f69 | 486 | clk_enable_unlock(flags); |
b2476490 MT |
487 | |
488 | out: | |
489 | return; | |
490 | } | |
491 | ||
1e435256 OJ |
492 | static bool clk_ignore_unused; |
493 | static int __init clk_ignore_unused_setup(char *__unused) | |
494 | { | |
495 | clk_ignore_unused = true; | |
496 | return 1; | |
497 | } | |
498 | __setup("clk_ignore_unused", clk_ignore_unused_setup); | |
499 | ||
b2476490 MT |
500 | static int clk_disable_unused(void) |
501 | { | |
502 | struct clk *clk; | |
b2476490 | 503 | |
1e435256 OJ |
504 | if (clk_ignore_unused) { |
505 | pr_warn("clk: Not disabling unused clocks\n"); | |
506 | return 0; | |
507 | } | |
508 | ||
eab89f69 | 509 | clk_prepare_lock(); |
b2476490 | 510 | |
b67bfe0d | 511 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
512 | clk_disable_unused_subtree(clk); |
513 | ||
b67bfe0d | 514 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
b2476490 MT |
515 | clk_disable_unused_subtree(clk); |
516 | ||
1c155b3d UH |
517 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
518 | clk_unprepare_unused_subtree(clk); | |
519 | ||
520 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) | |
521 | clk_unprepare_unused_subtree(clk); | |
522 | ||
eab89f69 | 523 | clk_prepare_unlock(); |
b2476490 MT |
524 | |
525 | return 0; | |
526 | } | |
d41d5805 | 527 | late_initcall_sync(clk_disable_unused); |
b2476490 MT |
528 | |
529 | /*** helper functions ***/ | |
530 | ||
65800b2c | 531 | const char *__clk_get_name(struct clk *clk) |
b2476490 MT |
532 | { |
533 | return !clk ? NULL : clk->name; | |
534 | } | |
4895084c | 535 | EXPORT_SYMBOL_GPL(__clk_get_name); |
b2476490 | 536 | |
65800b2c | 537 | struct clk_hw *__clk_get_hw(struct clk *clk) |
b2476490 MT |
538 | { |
539 | return !clk ? NULL : clk->hw; | |
540 | } | |
0b7f04b8 | 541 | EXPORT_SYMBOL_GPL(__clk_get_hw); |
b2476490 | 542 | |
65800b2c | 543 | u8 __clk_get_num_parents(struct clk *clk) |
b2476490 | 544 | { |
2ac6b1f5 | 545 | return !clk ? 0 : clk->num_parents; |
b2476490 | 546 | } |
0b7f04b8 | 547 | EXPORT_SYMBOL_GPL(__clk_get_num_parents); |
b2476490 | 548 | |
65800b2c | 549 | struct clk *__clk_get_parent(struct clk *clk) |
b2476490 MT |
550 | { |
551 | return !clk ? NULL : clk->parent; | |
552 | } | |
0b7f04b8 | 553 | EXPORT_SYMBOL_GPL(__clk_get_parent); |
b2476490 | 554 | |
7ef3dcc8 JH |
555 | struct clk *clk_get_parent_by_index(struct clk *clk, u8 index) |
556 | { | |
557 | if (!clk || index >= clk->num_parents) | |
558 | return NULL; | |
559 | else if (!clk->parents) | |
560 | return __clk_lookup(clk->parent_names[index]); | |
561 | else if (!clk->parents[index]) | |
562 | return clk->parents[index] = | |
563 | __clk_lookup(clk->parent_names[index]); | |
564 | else | |
565 | return clk->parents[index]; | |
566 | } | |
0b7f04b8 | 567 | EXPORT_SYMBOL_GPL(clk_get_parent_by_index); |
7ef3dcc8 | 568 | |
65800b2c | 569 | unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 570 | { |
2ac6b1f5 | 571 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
572 | } |
573 | ||
65800b2c | 574 | unsigned int __clk_get_prepare_count(struct clk *clk) |
b2476490 | 575 | { |
2ac6b1f5 | 576 | return !clk ? 0 : clk->prepare_count; |
b2476490 MT |
577 | } |
578 | ||
579 | unsigned long __clk_get_rate(struct clk *clk) | |
580 | { | |
581 | unsigned long ret; | |
582 | ||
583 | if (!clk) { | |
34e44fe8 | 584 | ret = 0; |
b2476490 MT |
585 | goto out; |
586 | } | |
587 | ||
588 | ret = clk->rate; | |
589 | ||
590 | if (clk->flags & CLK_IS_ROOT) | |
591 | goto out; | |
592 | ||
593 | if (!clk->parent) | |
34e44fe8 | 594 | ret = 0; |
b2476490 MT |
595 | |
596 | out: | |
597 | return ret; | |
598 | } | |
0b7f04b8 | 599 | EXPORT_SYMBOL_GPL(__clk_get_rate); |
b2476490 | 600 | |
5279fc40 BB |
601 | unsigned long __clk_get_accuracy(struct clk *clk) |
602 | { | |
603 | if (!clk) | |
604 | return 0; | |
605 | ||
606 | return clk->accuracy; | |
607 | } | |
608 | ||
65800b2c | 609 | unsigned long __clk_get_flags(struct clk *clk) |
b2476490 | 610 | { |
2ac6b1f5 | 611 | return !clk ? 0 : clk->flags; |
b2476490 | 612 | } |
b05c6836 | 613 | EXPORT_SYMBOL_GPL(__clk_get_flags); |
b2476490 | 614 | |
3d6ee287 UH |
615 | bool __clk_is_prepared(struct clk *clk) |
616 | { | |
617 | int ret; | |
618 | ||
619 | if (!clk) | |
620 | return false; | |
621 | ||
622 | /* | |
623 | * .is_prepared is optional for clocks that can prepare | |
624 | * fall back to software usage counter if it is missing | |
625 | */ | |
626 | if (!clk->ops->is_prepared) { | |
627 | ret = clk->prepare_count ? 1 : 0; | |
628 | goto out; | |
629 | } | |
630 | ||
631 | ret = clk->ops->is_prepared(clk->hw); | |
632 | out: | |
633 | return !!ret; | |
634 | } | |
635 | ||
2ac6b1f5 | 636 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
637 | { |
638 | int ret; | |
639 | ||
640 | if (!clk) | |
2ac6b1f5 | 641 | return false; |
b2476490 MT |
642 | |
643 | /* | |
644 | * .is_enabled is only mandatory for clocks that gate | |
645 | * fall back to software usage counter if .is_enabled is missing | |
646 | */ | |
647 | if (!clk->ops->is_enabled) { | |
648 | ret = clk->enable_count ? 1 : 0; | |
649 | goto out; | |
650 | } | |
651 | ||
652 | ret = clk->ops->is_enabled(clk->hw); | |
653 | out: | |
2ac6b1f5 | 654 | return !!ret; |
b2476490 | 655 | } |
0b7f04b8 | 656 | EXPORT_SYMBOL_GPL(__clk_is_enabled); |
b2476490 MT |
657 | |
658 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
659 | { | |
660 | struct clk *child; | |
661 | struct clk *ret; | |
b2476490 MT |
662 | |
663 | if (!strcmp(clk->name, name)) | |
664 | return clk; | |
665 | ||
b67bfe0d | 666 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
667 | ret = __clk_lookup_subtree(name, child); |
668 | if (ret) | |
669 | return ret; | |
670 | } | |
671 | ||
672 | return NULL; | |
673 | } | |
674 | ||
675 | struct clk *__clk_lookup(const char *name) | |
676 | { | |
677 | struct clk *root_clk; | |
678 | struct clk *ret; | |
b2476490 MT |
679 | |
680 | if (!name) | |
681 | return NULL; | |
682 | ||
683 | /* search the 'proper' clk tree first */ | |
b67bfe0d | 684 | hlist_for_each_entry(root_clk, &clk_root_list, child_node) { |
b2476490 MT |
685 | ret = __clk_lookup_subtree(name, root_clk); |
686 | if (ret) | |
687 | return ret; | |
688 | } | |
689 | ||
690 | /* if not found, then search the orphan tree */ | |
b67bfe0d | 691 | hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { |
b2476490 MT |
692 | ret = __clk_lookup_subtree(name, root_clk); |
693 | if (ret) | |
694 | return ret; | |
695 | } | |
696 | ||
697 | return NULL; | |
698 | } | |
699 | ||
e366fdd7 JH |
700 | /* |
701 | * Helper for finding best parent to provide a given frequency. This can be used | |
702 | * directly as a determine_rate callback (e.g. for a mux), or from a more | |
703 | * complex clock that may combine a mux with other operations. | |
704 | */ | |
705 | long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, | |
706 | unsigned long *best_parent_rate, | |
707 | struct clk **best_parent_p) | |
708 | { | |
709 | struct clk *clk = hw->clk, *parent, *best_parent = NULL; | |
710 | int i, num_parents; | |
711 | unsigned long parent_rate, best = 0; | |
712 | ||
713 | /* if NO_REPARENT flag set, pass through to current parent */ | |
714 | if (clk->flags & CLK_SET_RATE_NO_REPARENT) { | |
715 | parent = clk->parent; | |
716 | if (clk->flags & CLK_SET_RATE_PARENT) | |
717 | best = __clk_round_rate(parent, rate); | |
718 | else if (parent) | |
719 | best = __clk_get_rate(parent); | |
720 | else | |
721 | best = __clk_get_rate(clk); | |
722 | goto out; | |
723 | } | |
724 | ||
725 | /* find the parent that can provide the fastest rate <= rate */ | |
726 | num_parents = clk->num_parents; | |
727 | for (i = 0; i < num_parents; i++) { | |
728 | parent = clk_get_parent_by_index(clk, i); | |
729 | if (!parent) | |
730 | continue; | |
731 | if (clk->flags & CLK_SET_RATE_PARENT) | |
732 | parent_rate = __clk_round_rate(parent, rate); | |
733 | else | |
734 | parent_rate = __clk_get_rate(parent); | |
735 | if (parent_rate <= rate && parent_rate > best) { | |
736 | best_parent = parent; | |
737 | best = parent_rate; | |
738 | } | |
739 | } | |
740 | ||
741 | out: | |
742 | if (best_parent) | |
743 | *best_parent_p = best_parent; | |
744 | *best_parent_rate = best; | |
745 | ||
746 | return best; | |
747 | } | |
0b7f04b8 | 748 | EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); |
e366fdd7 | 749 | |
b2476490 MT |
750 | /*** clk api ***/ |
751 | ||
752 | void __clk_unprepare(struct clk *clk) | |
753 | { | |
754 | if (!clk) | |
755 | return; | |
756 | ||
757 | if (WARN_ON(clk->prepare_count == 0)) | |
758 | return; | |
759 | ||
760 | if (--clk->prepare_count > 0) | |
761 | return; | |
762 | ||
763 | WARN_ON(clk->enable_count > 0); | |
764 | ||
765 | if (clk->ops->unprepare) | |
766 | clk->ops->unprepare(clk->hw); | |
767 | ||
768 | __clk_unprepare(clk->parent); | |
769 | } | |
770 | ||
771 | /** | |
772 | * clk_unprepare - undo preparation of a clock source | |
24ee1a08 | 773 | * @clk: the clk being unprepared |
b2476490 MT |
774 | * |
775 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
776 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
777 | * if the operation may sleep. One example is a clk which is accessed over | |
778 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
779 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
780 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
781 | */ | |
782 | void clk_unprepare(struct clk *clk) | |
783 | { | |
63589e92 SB |
784 | if (IS_ERR_OR_NULL(clk)) |
785 | return; | |
786 | ||
eab89f69 | 787 | clk_prepare_lock(); |
b2476490 | 788 | __clk_unprepare(clk); |
eab89f69 | 789 | clk_prepare_unlock(); |
b2476490 MT |
790 | } |
791 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
792 | ||
793 | int __clk_prepare(struct clk *clk) | |
794 | { | |
795 | int ret = 0; | |
796 | ||
797 | if (!clk) | |
798 | return 0; | |
799 | ||
800 | if (clk->prepare_count == 0) { | |
801 | ret = __clk_prepare(clk->parent); | |
802 | if (ret) | |
803 | return ret; | |
804 | ||
805 | if (clk->ops->prepare) { | |
806 | ret = clk->ops->prepare(clk->hw); | |
807 | if (ret) { | |
808 | __clk_unprepare(clk->parent); | |
809 | return ret; | |
810 | } | |
811 | } | |
812 | } | |
813 | ||
814 | clk->prepare_count++; | |
815 | ||
816 | return 0; | |
817 | } | |
818 | ||
819 | /** | |
820 | * clk_prepare - prepare a clock source | |
821 | * @clk: the clk being prepared | |
822 | * | |
823 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
824 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
825 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
826 | * the complex case a clk ungate operation may require a fast and a slow part. | |
827 | * It is this reason that clk_prepare and clk_enable are not mutually | |
828 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
829 | * Returns 0 on success, -EERROR otherwise. | |
830 | */ | |
831 | int clk_prepare(struct clk *clk) | |
832 | { | |
833 | int ret; | |
834 | ||
eab89f69 | 835 | clk_prepare_lock(); |
b2476490 | 836 | ret = __clk_prepare(clk); |
eab89f69 | 837 | clk_prepare_unlock(); |
b2476490 MT |
838 | |
839 | return ret; | |
840 | } | |
841 | EXPORT_SYMBOL_GPL(clk_prepare); | |
842 | ||
843 | static void __clk_disable(struct clk *clk) | |
844 | { | |
845 | if (!clk) | |
846 | return; | |
847 | ||
848 | if (WARN_ON(clk->enable_count == 0)) | |
849 | return; | |
850 | ||
851 | if (--clk->enable_count > 0) | |
852 | return; | |
853 | ||
854 | if (clk->ops->disable) | |
855 | clk->ops->disable(clk->hw); | |
856 | ||
857 | __clk_disable(clk->parent); | |
858 | } | |
859 | ||
860 | /** | |
861 | * clk_disable - gate a clock | |
862 | * @clk: the clk being gated | |
863 | * | |
864 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
865 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
866 | * clk if the operation is fast and will never sleep. One example is a | |
867 | * SoC-internal clk which is controlled via simple register writes. In the | |
868 | * complex case a clk gate operation may require a fast and a slow part. It is | |
869 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
870 | * In fact clk_disable must be called before clk_unprepare. | |
871 | */ | |
872 | void clk_disable(struct clk *clk) | |
873 | { | |
874 | unsigned long flags; | |
875 | ||
63589e92 SB |
876 | if (IS_ERR_OR_NULL(clk)) |
877 | return; | |
878 | ||
eab89f69 | 879 | flags = clk_enable_lock(); |
b2476490 | 880 | __clk_disable(clk); |
eab89f69 | 881 | clk_enable_unlock(flags); |
b2476490 MT |
882 | } |
883 | EXPORT_SYMBOL_GPL(clk_disable); | |
884 | ||
885 | static int __clk_enable(struct clk *clk) | |
886 | { | |
887 | int ret = 0; | |
888 | ||
889 | if (!clk) | |
890 | return 0; | |
891 | ||
892 | if (WARN_ON(clk->prepare_count == 0)) | |
893 | return -ESHUTDOWN; | |
894 | ||
895 | if (clk->enable_count == 0) { | |
896 | ret = __clk_enable(clk->parent); | |
897 | ||
898 | if (ret) | |
899 | return ret; | |
900 | ||
901 | if (clk->ops->enable) { | |
902 | ret = clk->ops->enable(clk->hw); | |
903 | if (ret) { | |
904 | __clk_disable(clk->parent); | |
905 | return ret; | |
906 | } | |
907 | } | |
908 | } | |
909 | ||
910 | clk->enable_count++; | |
911 | return 0; | |
912 | } | |
913 | ||
914 | /** | |
915 | * clk_enable - ungate a clock | |
916 | * @clk: the clk being ungated | |
917 | * | |
918 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
919 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
920 | * if the operation will never sleep. One example is a SoC-internal clk which | |
921 | * is controlled via simple register writes. In the complex case a clk ungate | |
922 | * operation may require a fast and a slow part. It is this reason that | |
923 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
924 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
925 | * otherwise. | |
926 | */ | |
927 | int clk_enable(struct clk *clk) | |
928 | { | |
929 | unsigned long flags; | |
930 | int ret; | |
931 | ||
eab89f69 | 932 | flags = clk_enable_lock(); |
b2476490 | 933 | ret = __clk_enable(clk); |
eab89f69 | 934 | clk_enable_unlock(flags); |
b2476490 MT |
935 | |
936 | return ret; | |
937 | } | |
938 | EXPORT_SYMBOL_GPL(clk_enable); | |
939 | ||
b2476490 MT |
940 | /** |
941 | * __clk_round_rate - round the given rate for a clk | |
942 | * @clk: round the rate of this clock | |
24ee1a08 | 943 | * @rate: the rate which is to be rounded |
b2476490 MT |
944 | * |
945 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
946 | */ | |
947 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
948 | { | |
81536e07 | 949 | unsigned long parent_rate = 0; |
71472c0c | 950 | struct clk *parent; |
b2476490 MT |
951 | |
952 | if (!clk) | |
2ac6b1f5 | 953 | return 0; |
b2476490 | 954 | |
71472c0c JH |
955 | parent = clk->parent; |
956 | if (parent) | |
957 | parent_rate = parent->rate; | |
958 | ||
959 | if (clk->ops->determine_rate) | |
960 | return clk->ops->determine_rate(clk->hw, rate, &parent_rate, | |
961 | &parent); | |
962 | else if (clk->ops->round_rate) | |
963 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); | |
964 | else if (clk->flags & CLK_SET_RATE_PARENT) | |
965 | return __clk_round_rate(clk->parent, rate); | |
966 | else | |
967 | return clk->rate; | |
b2476490 | 968 | } |
1cdf8ee2 | 969 | EXPORT_SYMBOL_GPL(__clk_round_rate); |
b2476490 MT |
970 | |
971 | /** | |
972 | * clk_round_rate - round the given rate for a clk | |
973 | * @clk: the clk for which we are rounding a rate | |
974 | * @rate: the rate which is to be rounded | |
975 | * | |
976 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
977 | * use which is then returned. If clk doesn't support round_rate operation | |
978 | * then the parent rate is returned. | |
979 | */ | |
980 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
981 | { | |
982 | unsigned long ret; | |
983 | ||
eab89f69 | 984 | clk_prepare_lock(); |
b2476490 | 985 | ret = __clk_round_rate(clk, rate); |
eab89f69 | 986 | clk_prepare_unlock(); |
b2476490 MT |
987 | |
988 | return ret; | |
989 | } | |
990 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
991 | ||
992 | /** | |
993 | * __clk_notify - call clk notifier chain | |
994 | * @clk: struct clk * that is changing rate | |
995 | * @msg: clk notifier type (see include/linux/clk.h) | |
996 | * @old_rate: old clk rate | |
997 | * @new_rate: new clk rate | |
998 | * | |
999 | * Triggers a notifier call chain on the clk rate-change notification | |
1000 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
1001 | * and current rates to the notifier callback. Intended to be called by | |
1002 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
1003 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
1004 | * a driver returns that. | |
1005 | */ | |
1006 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
1007 | unsigned long old_rate, unsigned long new_rate) | |
1008 | { | |
1009 | struct clk_notifier *cn; | |
1010 | struct clk_notifier_data cnd; | |
1011 | int ret = NOTIFY_DONE; | |
1012 | ||
1013 | cnd.clk = clk; | |
1014 | cnd.old_rate = old_rate; | |
1015 | cnd.new_rate = new_rate; | |
1016 | ||
1017 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
1018 | if (cn->clk == clk) { | |
1019 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
1020 | &cnd); | |
1021 | break; | |
1022 | } | |
1023 | } | |
1024 | ||
1025 | return ret; | |
1026 | } | |
1027 | ||
5279fc40 BB |
1028 | /** |
1029 | * __clk_recalc_accuracies | |
1030 | * @clk: first clk in the subtree | |
1031 | * | |
1032 | * Walks the subtree of clks starting with clk and recalculates accuracies as | |
1033 | * it goes. Note that if a clk does not implement the .recalc_accuracy | |
1034 | * callback then it is assumed that the clock will take on the accuracy of it's | |
1035 | * parent. | |
1036 | * | |
1037 | * Caller must hold prepare_lock. | |
1038 | */ | |
1039 | static void __clk_recalc_accuracies(struct clk *clk) | |
1040 | { | |
1041 | unsigned long parent_accuracy = 0; | |
1042 | struct clk *child; | |
1043 | ||
1044 | if (clk->parent) | |
1045 | parent_accuracy = clk->parent->accuracy; | |
1046 | ||
1047 | if (clk->ops->recalc_accuracy) | |
1048 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1049 | parent_accuracy); | |
1050 | else | |
1051 | clk->accuracy = parent_accuracy; | |
1052 | ||
1053 | hlist_for_each_entry(child, &clk->children, child_node) | |
1054 | __clk_recalc_accuracies(child); | |
1055 | } | |
1056 | ||
1057 | /** | |
1058 | * clk_get_accuracy - return the accuracy of clk | |
1059 | * @clk: the clk whose accuracy is being returned | |
1060 | * | |
1061 | * Simply returns the cached accuracy of the clk, unless | |
1062 | * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be | |
1063 | * issued. | |
1064 | * If clk is NULL then returns 0. | |
1065 | */ | |
1066 | long clk_get_accuracy(struct clk *clk) | |
1067 | { | |
1068 | unsigned long accuracy; | |
1069 | ||
1070 | clk_prepare_lock(); | |
1071 | if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE)) | |
1072 | __clk_recalc_accuracies(clk); | |
1073 | ||
1074 | accuracy = __clk_get_accuracy(clk); | |
1075 | clk_prepare_unlock(); | |
1076 | ||
1077 | return accuracy; | |
1078 | } | |
1079 | EXPORT_SYMBOL_GPL(clk_get_accuracy); | |
1080 | ||
8f2c2db1 SB |
1081 | static unsigned long clk_recalc(struct clk *clk, unsigned long parent_rate) |
1082 | { | |
1083 | if (clk->ops->recalc_rate) | |
1084 | return clk->ops->recalc_rate(clk->hw, parent_rate); | |
1085 | return parent_rate; | |
1086 | } | |
1087 | ||
b2476490 MT |
1088 | /** |
1089 | * __clk_recalc_rates | |
1090 | * @clk: first clk in the subtree | |
1091 | * @msg: notification type (see include/linux/clk.h) | |
1092 | * | |
1093 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
1094 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
24ee1a08 | 1095 | * it is assumed that the clock will take on the rate of its parent. |
b2476490 MT |
1096 | * |
1097 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
1098 | * if necessary. | |
1099 | * | |
1100 | * Caller must hold prepare_lock. | |
1101 | */ | |
1102 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
1103 | { | |
1104 | unsigned long old_rate; | |
1105 | unsigned long parent_rate = 0; | |
b2476490 MT |
1106 | struct clk *child; |
1107 | ||
1108 | old_rate = clk->rate; | |
1109 | ||
1110 | if (clk->parent) | |
1111 | parent_rate = clk->parent->rate; | |
1112 | ||
8f2c2db1 | 1113 | clk->rate = clk_recalc(clk, parent_rate); |
b2476490 MT |
1114 | |
1115 | /* | |
1116 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
1117 | * & ABORT_RATE_CHANGE notifiers | |
1118 | */ | |
1119 | if (clk->notifier_count && msg) | |
1120 | __clk_notify(clk, msg, old_rate, clk->rate); | |
1121 | ||
b67bfe0d | 1122 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
1123 | __clk_recalc_rates(child, msg); |
1124 | } | |
1125 | ||
a093bde2 UH |
1126 | /** |
1127 | * clk_get_rate - return the rate of clk | |
1128 | * @clk: the clk whose rate is being returned | |
1129 | * | |
1130 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
1131 | * is set, which means a recalc_rate will be issued. | |
1132 | * If clk is NULL then returns 0. | |
1133 | */ | |
1134 | unsigned long clk_get_rate(struct clk *clk) | |
1135 | { | |
1136 | unsigned long rate; | |
1137 | ||
eab89f69 | 1138 | clk_prepare_lock(); |
a093bde2 UH |
1139 | |
1140 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
1141 | __clk_recalc_rates(clk, 0); | |
1142 | ||
1143 | rate = __clk_get_rate(clk); | |
eab89f69 | 1144 | clk_prepare_unlock(); |
a093bde2 UH |
1145 | |
1146 | return rate; | |
1147 | } | |
1148 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
1149 | ||
f1c8b2ed | 1150 | static int clk_fetch_parent_index(struct clk *clk, struct clk *parent) |
4935b22c | 1151 | { |
f1c8b2ed | 1152 | int i; |
4935b22c | 1153 | |
f1c8b2ed | 1154 | if (!clk->parents) { |
96a7ed90 TF |
1155 | clk->parents = kcalloc(clk->num_parents, |
1156 | sizeof(struct clk *), GFP_KERNEL); | |
f1c8b2ed TF |
1157 | if (!clk->parents) |
1158 | return -ENOMEM; | |
1159 | } | |
4935b22c JH |
1160 | |
1161 | /* | |
1162 | * find index of new parent clock using cached parent ptrs, | |
1163 | * or if not yet cached, use string name comparison and cache | |
1164 | * them now to avoid future calls to __clk_lookup. | |
1165 | */ | |
1166 | for (i = 0; i < clk->num_parents; i++) { | |
da0f0b2c | 1167 | if (clk->parents[i] == parent) |
f1c8b2ed | 1168 | return i; |
da0f0b2c TF |
1169 | |
1170 | if (clk->parents[i]) | |
1171 | continue; | |
1172 | ||
1173 | if (!strcmp(clk->parent_names[i], parent->name)) { | |
1174 | clk->parents[i] = __clk_lookup(parent->name); | |
f1c8b2ed | 1175 | return i; |
4935b22c JH |
1176 | } |
1177 | } | |
1178 | ||
f1c8b2ed | 1179 | return -EINVAL; |
4935b22c JH |
1180 | } |
1181 | ||
1182 | static void clk_reparent(struct clk *clk, struct clk *new_parent) | |
1183 | { | |
1184 | hlist_del(&clk->child_node); | |
1185 | ||
903efc55 JH |
1186 | if (new_parent) { |
1187 | /* avoid duplicate POST_RATE_CHANGE notifications */ | |
1188 | if (new_parent->new_child == clk) | |
1189 | new_parent->new_child = NULL; | |
1190 | ||
4935b22c | 1191 | hlist_add_head(&clk->child_node, &new_parent->children); |
903efc55 | 1192 | } else { |
4935b22c | 1193 | hlist_add_head(&clk->child_node, &clk_orphan_list); |
903efc55 | 1194 | } |
4935b22c JH |
1195 | |
1196 | clk->parent = new_parent; | |
1197 | } | |
1198 | ||
3fa2252b | 1199 | static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent) |
4935b22c JH |
1200 | { |
1201 | unsigned long flags; | |
4935b22c JH |
1202 | struct clk *old_parent = clk->parent; |
1203 | ||
1204 | /* | |
1205 | * Migrate prepare state between parents and prevent race with | |
1206 | * clk_enable(). | |
1207 | * | |
1208 | * If the clock is not prepared, then a race with | |
1209 | * clk_enable/disable() is impossible since we already have the | |
1210 | * prepare lock (future calls to clk_enable() need to be preceded by | |
1211 | * a clk_prepare()). | |
1212 | * | |
1213 | * If the clock is prepared, migrate the prepared state to the new | |
1214 | * parent and also protect against a race with clk_enable() by | |
1215 | * forcing the clock and the new parent on. This ensures that all | |
1216 | * future calls to clk_enable() are practically NOPs with respect to | |
1217 | * hardware and software states. | |
1218 | * | |
1219 | * See also: Comment for clk_set_parent() below. | |
1220 | */ | |
1221 | if (clk->prepare_count) { | |
1222 | __clk_prepare(parent); | |
1223 | clk_enable(parent); | |
1224 | clk_enable(clk); | |
1225 | } | |
1226 | ||
1227 | /* update the clk tree topology */ | |
1228 | flags = clk_enable_lock(); | |
1229 | clk_reparent(clk, parent); | |
1230 | clk_enable_unlock(flags); | |
1231 | ||
3fa2252b SB |
1232 | return old_parent; |
1233 | } | |
1234 | ||
1235 | static void __clk_set_parent_after(struct clk *clk, struct clk *parent, | |
1236 | struct clk *old_parent) | |
1237 | { | |
1238 | /* | |
1239 | * Finish the migration of prepare state and undo the changes done | |
1240 | * for preventing a race with clk_enable(). | |
1241 | */ | |
1242 | if (clk->prepare_count) { | |
1243 | clk_disable(clk); | |
1244 | clk_disable(old_parent); | |
1245 | __clk_unprepare(old_parent); | |
1246 | } | |
3fa2252b SB |
1247 | } |
1248 | ||
1249 | static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) | |
1250 | { | |
1251 | unsigned long flags; | |
1252 | int ret = 0; | |
1253 | struct clk *old_parent; | |
1254 | ||
1255 | old_parent = __clk_set_parent_before(clk, parent); | |
1256 | ||
4935b22c JH |
1257 | /* change clock input source */ |
1258 | if (parent && clk->ops->set_parent) | |
1259 | ret = clk->ops->set_parent(clk->hw, p_index); | |
1260 | ||
1261 | if (ret) { | |
1262 | flags = clk_enable_lock(); | |
1263 | clk_reparent(clk, old_parent); | |
1264 | clk_enable_unlock(flags); | |
1265 | ||
1266 | if (clk->prepare_count) { | |
1267 | clk_disable(clk); | |
1268 | clk_disable(parent); | |
1269 | __clk_unprepare(parent); | |
1270 | } | |
1271 | return ret; | |
1272 | } | |
1273 | ||
3fa2252b | 1274 | __clk_set_parent_after(clk, parent, old_parent); |
4935b22c | 1275 | |
4935b22c JH |
1276 | return 0; |
1277 | } | |
1278 | ||
b2476490 MT |
1279 | /** |
1280 | * __clk_speculate_rates | |
1281 | * @clk: first clk in the subtree | |
1282 | * @parent_rate: the "future" rate of clk's parent | |
1283 | * | |
1284 | * Walks the subtree of clks starting with clk, speculating rates as it | |
1285 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
1286 | * | |
1287 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
1288 | * pre-rate change notifications and returns early if no clks in the | |
1289 | * subtree have subscribed to the notifications. Note that if a clk does not | |
1290 | * implement the .recalc_rate callback then it is assumed that the clock will | |
24ee1a08 | 1291 | * take on the rate of its parent. |
b2476490 MT |
1292 | * |
1293 | * Caller must hold prepare_lock. | |
1294 | */ | |
1295 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
1296 | { | |
b2476490 MT |
1297 | struct clk *child; |
1298 | unsigned long new_rate; | |
1299 | int ret = NOTIFY_DONE; | |
1300 | ||
8f2c2db1 | 1301 | new_rate = clk_recalc(clk, parent_rate); |
b2476490 | 1302 | |
fb72a059 | 1303 | /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ |
b2476490 MT |
1304 | if (clk->notifier_count) |
1305 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
1306 | ||
86bcfa2e MT |
1307 | if (ret & NOTIFY_STOP_MASK) { |
1308 | pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n", | |
1309 | __func__, clk->name, ret); | |
b2476490 | 1310 | goto out; |
86bcfa2e | 1311 | } |
b2476490 | 1312 | |
b67bfe0d | 1313 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 | 1314 | ret = __clk_speculate_rates(child, new_rate); |
fb72a059 | 1315 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1316 | break; |
1317 | } | |
1318 | ||
1319 | out: | |
1320 | return ret; | |
1321 | } | |
1322 | ||
71472c0c JH |
1323 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate, |
1324 | struct clk *new_parent, u8 p_index) | |
b2476490 MT |
1325 | { |
1326 | struct clk *child; | |
b2476490 MT |
1327 | |
1328 | clk->new_rate = new_rate; | |
71472c0c JH |
1329 | clk->new_parent = new_parent; |
1330 | clk->new_parent_index = p_index; | |
1331 | /* include clk in new parent's PRE_RATE_CHANGE notifications */ | |
1332 | clk->new_child = NULL; | |
1333 | if (new_parent && new_parent != clk->parent) | |
1334 | new_parent->new_child = clk; | |
b2476490 | 1335 | |
b67bfe0d | 1336 | hlist_for_each_entry(child, &clk->children, child_node) { |
8f2c2db1 | 1337 | child->new_rate = clk_recalc(child, new_rate); |
71472c0c | 1338 | clk_calc_subtree(child, child->new_rate, NULL, 0); |
b2476490 MT |
1339 | } |
1340 | } | |
1341 | ||
1342 | /* | |
1343 | * calculate the new rates returning the topmost clock that has to be | |
1344 | * changed. | |
1345 | */ | |
1346 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
1347 | { | |
1348 | struct clk *top = clk; | |
71472c0c | 1349 | struct clk *old_parent, *parent; |
81536e07 | 1350 | unsigned long best_parent_rate = 0; |
b2476490 | 1351 | unsigned long new_rate; |
f1c8b2ed | 1352 | int p_index = 0; |
b2476490 | 1353 | |
7452b219 MT |
1354 | /* sanity */ |
1355 | if (IS_ERR_OR_NULL(clk)) | |
1356 | return NULL; | |
1357 | ||
63f5c3b2 | 1358 | /* save parent rate, if it exists */ |
71472c0c JH |
1359 | parent = old_parent = clk->parent; |
1360 | if (parent) | |
1361 | best_parent_rate = parent->rate; | |
1362 | ||
1363 | /* find the closest rate and parent clk/rate */ | |
1364 | if (clk->ops->determine_rate) { | |
1365 | new_rate = clk->ops->determine_rate(clk->hw, rate, | |
1366 | &best_parent_rate, | |
1367 | &parent); | |
1368 | } else if (clk->ops->round_rate) { | |
1369 | new_rate = clk->ops->round_rate(clk->hw, rate, | |
1370 | &best_parent_rate); | |
1371 | } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) { | |
1372 | /* pass-through clock without adjustable parent */ | |
1373 | clk->new_rate = clk->rate; | |
1374 | return NULL; | |
1375 | } else { | |
1376 | /* pass-through clock with adjustable parent */ | |
1377 | top = clk_calc_new_rates(parent, rate); | |
1378 | new_rate = parent->new_rate; | |
63f5c3b2 | 1379 | goto out; |
7452b219 MT |
1380 | } |
1381 | ||
71472c0c JH |
1382 | /* some clocks must be gated to change parent */ |
1383 | if (parent != old_parent && | |
1384 | (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1385 | pr_debug("%s: %s not gated but wants to reparent\n", | |
1386 | __func__, clk->name); | |
b2476490 MT |
1387 | return NULL; |
1388 | } | |
1389 | ||
71472c0c JH |
1390 | /* try finding the new parent index */ |
1391 | if (parent) { | |
1392 | p_index = clk_fetch_parent_index(clk, parent); | |
f1c8b2ed | 1393 | if (p_index < 0) { |
71472c0c JH |
1394 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1395 | __func__, parent->name, clk->name); | |
1396 | return NULL; | |
1397 | } | |
b2476490 MT |
1398 | } |
1399 | ||
71472c0c JH |
1400 | if ((clk->flags & CLK_SET_RATE_PARENT) && parent && |
1401 | best_parent_rate != parent->rate) | |
1402 | top = clk_calc_new_rates(parent, best_parent_rate); | |
b2476490 MT |
1403 | |
1404 | out: | |
71472c0c | 1405 | clk_calc_subtree(clk, new_rate, parent, p_index); |
b2476490 MT |
1406 | |
1407 | return top; | |
1408 | } | |
1409 | ||
1410 | /* | |
1411 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
1412 | * so that in case of an error we can walk down the whole tree again and | |
1413 | * abort the change. | |
1414 | */ | |
1415 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
1416 | { | |
71472c0c | 1417 | struct clk *child, *tmp_clk, *fail_clk = NULL; |
b2476490 MT |
1418 | int ret = NOTIFY_DONE; |
1419 | ||
1420 | if (clk->rate == clk->new_rate) | |
5fda6858 | 1421 | return NULL; |
b2476490 MT |
1422 | |
1423 | if (clk->notifier_count) { | |
1424 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
fb72a059 | 1425 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1426 | fail_clk = clk; |
1427 | } | |
1428 | ||
b67bfe0d | 1429 | hlist_for_each_entry(child, &clk->children, child_node) { |
71472c0c JH |
1430 | /* Skip children who will be reparented to another clock */ |
1431 | if (child->new_parent && child->new_parent != clk) | |
1432 | continue; | |
1433 | tmp_clk = clk_propagate_rate_change(child, event); | |
1434 | if (tmp_clk) | |
1435 | fail_clk = tmp_clk; | |
1436 | } | |
1437 | ||
1438 | /* handle the new child who might not be in clk->children yet */ | |
1439 | if (clk->new_child) { | |
1440 | tmp_clk = clk_propagate_rate_change(clk->new_child, event); | |
1441 | if (tmp_clk) | |
1442 | fail_clk = tmp_clk; | |
b2476490 MT |
1443 | } |
1444 | ||
1445 | return fail_clk; | |
1446 | } | |
1447 | ||
1448 | /* | |
1449 | * walk down a subtree and set the new rates notifying the rate | |
1450 | * change on the way | |
1451 | */ | |
1452 | static void clk_change_rate(struct clk *clk) | |
1453 | { | |
1454 | struct clk *child; | |
1455 | unsigned long old_rate; | |
bf47b4fd | 1456 | unsigned long best_parent_rate = 0; |
3fa2252b SB |
1457 | bool skip_set_rate = false; |
1458 | struct clk *old_parent; | |
b2476490 MT |
1459 | |
1460 | old_rate = clk->rate; | |
1461 | ||
3fa2252b SB |
1462 | if (clk->new_parent) |
1463 | best_parent_rate = clk->new_parent->rate; | |
1464 | else if (clk->parent) | |
bf47b4fd PM |
1465 | best_parent_rate = clk->parent->rate; |
1466 | ||
3fa2252b SB |
1467 | if (clk->new_parent && clk->new_parent != clk->parent) { |
1468 | old_parent = __clk_set_parent_before(clk, clk->new_parent); | |
1469 | ||
1470 | if (clk->ops->set_rate_and_parent) { | |
1471 | skip_set_rate = true; | |
1472 | clk->ops->set_rate_and_parent(clk->hw, clk->new_rate, | |
1473 | best_parent_rate, | |
1474 | clk->new_parent_index); | |
1475 | } else if (clk->ops->set_parent) { | |
1476 | clk->ops->set_parent(clk->hw, clk->new_parent_index); | |
1477 | } | |
1478 | ||
1479 | __clk_set_parent_after(clk, clk->new_parent, old_parent); | |
1480 | } | |
1481 | ||
1482 | if (!skip_set_rate && clk->ops->set_rate) | |
bf47b4fd | 1483 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 | 1484 | |
8f2c2db1 | 1485 | clk->rate = clk_recalc(clk, best_parent_rate); |
b2476490 MT |
1486 | |
1487 | if (clk->notifier_count && old_rate != clk->rate) | |
1488 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
1489 | ||
71472c0c JH |
1490 | hlist_for_each_entry(child, &clk->children, child_node) { |
1491 | /* Skip children who will be reparented to another clock */ | |
1492 | if (child->new_parent && child->new_parent != clk) | |
1493 | continue; | |
b2476490 | 1494 | clk_change_rate(child); |
71472c0c JH |
1495 | } |
1496 | ||
1497 | /* handle the new child who might not be in clk->children yet */ | |
1498 | if (clk->new_child) | |
1499 | clk_change_rate(clk->new_child); | |
b2476490 MT |
1500 | } |
1501 | ||
1502 | /** | |
1503 | * clk_set_rate - specify a new rate for clk | |
1504 | * @clk: the clk whose rate is being changed | |
1505 | * @rate: the new rate for clk | |
1506 | * | |
5654dc94 | 1507 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 1508 | * |
5654dc94 MT |
1509 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
1510 | * propagate up to clk's parent; whether or not this happens depends on the | |
1511 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
1512 | * after calling .round_rate then upstream parent propagation is ignored. If | |
1513 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
24ee1a08 | 1514 | * up to clk's parent and set its rate. Upward propagation will continue |
5654dc94 MT |
1515 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or |
1516 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 1517 | * |
5654dc94 MT |
1518 | * Rate changes are accomplished via tree traversal that also recalculates the |
1519 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
1520 | * |
1521 | * Returns 0 on success, -EERROR otherwise. | |
1522 | */ | |
1523 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
1524 | { | |
1525 | struct clk *top, *fail_clk; | |
1526 | int ret = 0; | |
1527 | ||
89ac8d7a MT |
1528 | if (!clk) |
1529 | return 0; | |
1530 | ||
b2476490 | 1531 | /* prevent racing with updates to the clock topology */ |
eab89f69 | 1532 | clk_prepare_lock(); |
b2476490 MT |
1533 | |
1534 | /* bail early if nothing to do */ | |
34e452a1 | 1535 | if (rate == clk_get_rate(clk)) |
b2476490 MT |
1536 | goto out; |
1537 | ||
7e0fa1b5 | 1538 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
1539 | ret = -EBUSY; |
1540 | goto out; | |
1541 | } | |
1542 | ||
b2476490 MT |
1543 | /* calculate new rates and get the topmost changed clock */ |
1544 | top = clk_calc_new_rates(clk, rate); | |
1545 | if (!top) { | |
1546 | ret = -EINVAL; | |
1547 | goto out; | |
1548 | } | |
1549 | ||
1550 | /* notify that we are about to change rates */ | |
1551 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
1552 | if (fail_clk) { | |
f7363861 | 1553 | pr_debug("%s: failed to set %s rate\n", __func__, |
b2476490 MT |
1554 | fail_clk->name); |
1555 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
1556 | ret = -EBUSY; | |
1557 | goto out; | |
1558 | } | |
1559 | ||
1560 | /* change the rates */ | |
1561 | clk_change_rate(top); | |
1562 | ||
b2476490 | 1563 | out: |
eab89f69 | 1564 | clk_prepare_unlock(); |
b2476490 MT |
1565 | |
1566 | return ret; | |
1567 | } | |
1568 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
1569 | ||
1570 | /** | |
1571 | * clk_get_parent - return the parent of a clk | |
1572 | * @clk: the clk whose parent gets returned | |
1573 | * | |
1574 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
1575 | */ | |
1576 | struct clk *clk_get_parent(struct clk *clk) | |
1577 | { | |
1578 | struct clk *parent; | |
1579 | ||
eab89f69 | 1580 | clk_prepare_lock(); |
b2476490 | 1581 | parent = __clk_get_parent(clk); |
eab89f69 | 1582 | clk_prepare_unlock(); |
b2476490 MT |
1583 | |
1584 | return parent; | |
1585 | } | |
1586 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
1587 | ||
1588 | /* | |
1589 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
1590 | * optional for single-parent clocks. Always call .get_parent if it is | |
1591 | * available and WARN if it is missing for multi-parent clocks. | |
1592 | * | |
1593 | * For single-parent clocks without .get_parent, first check to see if the | |
1594 | * .parents array exists, and if so use it to avoid an expensive tree | |
1595 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
1596 | */ | |
1597 | static struct clk *__clk_init_parent(struct clk *clk) | |
1598 | { | |
1599 | struct clk *ret = NULL; | |
1600 | u8 index; | |
1601 | ||
1602 | /* handle the trivial cases */ | |
1603 | ||
1604 | if (!clk->num_parents) | |
1605 | goto out; | |
1606 | ||
1607 | if (clk->num_parents == 1) { | |
1608 | if (IS_ERR_OR_NULL(clk->parent)) | |
1609 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); | |
1610 | ret = clk->parent; | |
1611 | goto out; | |
1612 | } | |
1613 | ||
1614 | if (!clk->ops->get_parent) { | |
1615 | WARN(!clk->ops->get_parent, | |
1616 | "%s: multi-parent clocks must implement .get_parent\n", | |
1617 | __func__); | |
1618 | goto out; | |
1619 | }; | |
1620 | ||
1621 | /* | |
1622 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1623 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1624 | * clk->parent here; that is done by the calling function | |
1625 | */ | |
1626 | ||
1627 | index = clk->ops->get_parent(clk->hw); | |
1628 | ||
1629 | if (!clk->parents) | |
1630 | clk->parents = | |
96a7ed90 | 1631 | kcalloc(clk->num_parents, sizeof(struct clk *), |
b2476490 MT |
1632 | GFP_KERNEL); |
1633 | ||
7ef3dcc8 | 1634 | ret = clk_get_parent_by_index(clk, index); |
b2476490 MT |
1635 | |
1636 | out: | |
1637 | return ret; | |
1638 | } | |
1639 | ||
b33d212f UH |
1640 | void __clk_reparent(struct clk *clk, struct clk *new_parent) |
1641 | { | |
1642 | clk_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 | ||
031dcc9b UH |
1673 | /* verify ops for for multi-parent clks */ |
1674 | if ((clk->num_parents > 1) && (!clk->ops->set_parent)) | |
b2476490 MT |
1675 | return -ENOSYS; |
1676 | ||
1677 | /* prevent racing with updates to the clock topology */ | |
eab89f69 | 1678 | clk_prepare_lock(); |
b2476490 MT |
1679 | |
1680 | if (clk->parent == parent) | |
1681 | goto out; | |
1682 | ||
031dcc9b UH |
1683 | /* check that we are allowed to re-parent if the clock is in use */ |
1684 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1685 | ret = -EBUSY; | |
1686 | goto out; | |
1687 | } | |
1688 | ||
1689 | /* try finding the new parent index */ | |
1690 | if (parent) { | |
1691 | p_index = clk_fetch_parent_index(clk, parent); | |
1692 | p_rate = parent->rate; | |
f1c8b2ed | 1693 | if (p_index < 0) { |
031dcc9b UH |
1694 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1695 | __func__, parent->name, clk->name); | |
f1c8b2ed | 1696 | ret = p_index; |
031dcc9b UH |
1697 | goto out; |
1698 | } | |
1699 | } | |
1700 | ||
b2476490 | 1701 | /* propagate PRE_RATE_CHANGE notifications */ |
f3aab5d6 | 1702 | ret = __clk_speculate_rates(clk, p_rate); |
b2476490 MT |
1703 | |
1704 | /* abort if a driver objects */ | |
fb72a059 | 1705 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1706 | goto out; |
1707 | ||
031dcc9b UH |
1708 | /* do the re-parent */ |
1709 | ret = __clk_set_parent(clk, parent, p_index); | |
b2476490 | 1710 | |
5279fc40 BB |
1711 | /* propagate rate an accuracy recalculation accordingly */ |
1712 | if (ret) { | |
b2476490 | 1713 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); |
5279fc40 | 1714 | } else { |
a68de8e4 | 1715 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
5279fc40 BB |
1716 | __clk_recalc_accuracies(clk); |
1717 | } | |
b2476490 MT |
1718 | |
1719 | out: | |
eab89f69 | 1720 | clk_prepare_unlock(); |
b2476490 MT |
1721 | |
1722 | return ret; | |
1723 | } | |
1724 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1725 | ||
1726 | /** | |
1727 | * __clk_init - initialize the data structures in a struct clk | |
1728 | * @dev: device initializing this clk, placeholder for now | |
1729 | * @clk: clk being initialized | |
1730 | * | |
1731 | * Initializes the lists in struct clk, queries the hardware for the | |
1732 | * parent and rate and sets them both. | |
b2476490 | 1733 | */ |
d1302a36 | 1734 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1735 | { |
d1302a36 | 1736 | int i, ret = 0; |
b2476490 | 1737 | struct clk *orphan; |
b67bfe0d | 1738 | struct hlist_node *tmp2; |
b2476490 MT |
1739 | |
1740 | if (!clk) | |
d1302a36 | 1741 | return -EINVAL; |
b2476490 | 1742 | |
eab89f69 | 1743 | clk_prepare_lock(); |
b2476490 MT |
1744 | |
1745 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1746 | if (__clk_lookup(clk->name)) { |
1747 | pr_debug("%s: clk %s already initialized\n", | |
1748 | __func__, clk->name); | |
1749 | ret = -EEXIST; | |
b2476490 | 1750 | goto out; |
d1302a36 | 1751 | } |
b2476490 | 1752 | |
d4d7e3dd MT |
1753 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1754 | if (clk->ops->set_rate && | |
71472c0c JH |
1755 | !((clk->ops->round_rate || clk->ops->determine_rate) && |
1756 | clk->ops->recalc_rate)) { | |
1757 | pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", | |
d4d7e3dd | 1758 | __func__, clk->name); |
d1302a36 | 1759 | ret = -EINVAL; |
d4d7e3dd MT |
1760 | goto out; |
1761 | } | |
1762 | ||
1763 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1764 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1765 | __func__, clk->name); | |
d1302a36 | 1766 | ret = -EINVAL; |
d4d7e3dd MT |
1767 | goto out; |
1768 | } | |
1769 | ||
3fa2252b SB |
1770 | if (clk->ops->set_rate_and_parent && |
1771 | !(clk->ops->set_parent && clk->ops->set_rate)) { | |
1772 | pr_warn("%s: %s must implement .set_parent & .set_rate\n", | |
1773 | __func__, clk->name); | |
1774 | ret = -EINVAL; | |
1775 | goto out; | |
1776 | } | |
1777 | ||
b2476490 MT |
1778 | /* throw a WARN if any entries in parent_names are NULL */ |
1779 | for (i = 0; i < clk->num_parents; i++) | |
1780 | WARN(!clk->parent_names[i], | |
1781 | "%s: invalid NULL in %s's .parent_names\n", | |
1782 | __func__, clk->name); | |
1783 | ||
1784 | /* | |
1785 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1786 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1787 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1788 | * must always check for a NULL pointer and try to populate it if | |
1789 | * necessary. | |
1790 | * | |
1791 | * If clk->parents is not NULL we skip this entire block. This allows | |
1792 | * for clock drivers to statically initialize clk->parents. | |
1793 | */ | |
9ca1c5a4 | 1794 | if (clk->num_parents > 1 && !clk->parents) { |
96a7ed90 TF |
1795 | clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *), |
1796 | GFP_KERNEL); | |
b2476490 MT |
1797 | /* |
1798 | * __clk_lookup returns NULL for parents that have not been | |
1799 | * clk_init'd; thus any access to clk->parents[] must check | |
1800 | * for a NULL pointer. We can always perform lazy lookups for | |
1801 | * missing parents later on. | |
1802 | */ | |
1803 | if (clk->parents) | |
1804 | for (i = 0; i < clk->num_parents; i++) | |
1805 | clk->parents[i] = | |
1806 | __clk_lookup(clk->parent_names[i]); | |
1807 | } | |
1808 | ||
1809 | clk->parent = __clk_init_parent(clk); | |
1810 | ||
1811 | /* | |
1812 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1813 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1814 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1815 | * clk list. | |
1816 | * | |
1817 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1818 | * clocks and re-parent any that are children of the clock currently | |
1819 | * being clk_init'd. | |
1820 | */ | |
1821 | if (clk->parent) | |
1822 | hlist_add_head(&clk->child_node, | |
1823 | &clk->parent->children); | |
1824 | else if (clk->flags & CLK_IS_ROOT) | |
1825 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1826 | else | |
1827 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1828 | ||
5279fc40 BB |
1829 | /* |
1830 | * Set clk's accuracy. The preferred method is to use | |
1831 | * .recalc_accuracy. For simple clocks and lazy developers the default | |
1832 | * fallback is to use the parent's accuracy. If a clock doesn't have a | |
1833 | * parent (or is orphaned) then accuracy is set to zero (perfect | |
1834 | * clock). | |
1835 | */ | |
1836 | if (clk->ops->recalc_accuracy) | |
1837 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1838 | __clk_get_accuracy(clk->parent)); | |
1839 | else if (clk->parent) | |
1840 | clk->accuracy = clk->parent->accuracy; | |
1841 | else | |
1842 | clk->accuracy = 0; | |
1843 | ||
b2476490 MT |
1844 | /* |
1845 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1846 | * simple clocks and lazy developers the default fallback is to use the | |
1847 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1848 | * then rate is set to zero. | |
1849 | */ | |
1850 | if (clk->ops->recalc_rate) | |
1851 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1852 | __clk_get_rate(clk->parent)); | |
1853 | else if (clk->parent) | |
1854 | clk->rate = clk->parent->rate; | |
1855 | else | |
1856 | clk->rate = 0; | |
1857 | ||
3a5aec24 | 1858 | clk_debug_register(clk); |
b2476490 MT |
1859 | /* |
1860 | * walk the list of orphan clocks and reparent any that are children of | |
1861 | * this clock | |
1862 | */ | |
b67bfe0d | 1863 | hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { |
12d29886 | 1864 | if (orphan->num_parents && orphan->ops->get_parent) { |
1f61e5f1 MF |
1865 | i = orphan->ops->get_parent(orphan->hw); |
1866 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1867 | __clk_reparent(orphan, clk); | |
1868 | continue; | |
1869 | } | |
1870 | ||
b2476490 MT |
1871 | for (i = 0; i < orphan->num_parents; i++) |
1872 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1873 | __clk_reparent(orphan, clk); | |
1874 | break; | |
1875 | } | |
1f61e5f1 | 1876 | } |
b2476490 MT |
1877 | |
1878 | /* | |
1879 | * optional platform-specific magic | |
1880 | * | |
1881 | * The .init callback is not used by any of the basic clock types, but | |
1882 | * exists for weird hardware that must perform initialization magic. | |
1883 | * Please consider other ways of solving initialization problems before | |
24ee1a08 | 1884 | * using this callback, as its use is discouraged. |
b2476490 MT |
1885 | */ |
1886 | if (clk->ops->init) | |
1887 | clk->ops->init(clk->hw); | |
1888 | ||
fcb0ee6a | 1889 | kref_init(&clk->ref); |
b2476490 | 1890 | out: |
eab89f69 | 1891 | clk_prepare_unlock(); |
b2476490 | 1892 | |
d1302a36 | 1893 | return ret; |
b2476490 MT |
1894 | } |
1895 | ||
0197b3ea SK |
1896 | /** |
1897 | * __clk_register - register a clock and return a cookie. | |
1898 | * | |
1899 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1900 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1901 | * of the struct clk need to be initialized. | |
1902 | * | |
1903 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1904 | * data. | |
1905 | * | |
1906 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1907 | * very large numbers of clocks that need to be statically initialized. It is | |
1908 | * a layering violation to include clk-private.h from any code which implements | |
1909 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
24ee1a08 | 1910 | * separate C file from the logic that implements its operations. Returns 0 |
0197b3ea SK |
1911 | * on success, otherwise an error code. |
1912 | */ | |
1913 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
1914 | { | |
1915 | int ret; | |
1916 | struct clk *clk; | |
1917 | ||
1918 | clk = hw->clk; | |
1919 | clk->name = hw->init->name; | |
1920 | clk->ops = hw->init->ops; | |
1921 | clk->hw = hw; | |
1922 | clk->flags = hw->init->flags; | |
1923 | clk->parent_names = hw->init->parent_names; | |
1924 | clk->num_parents = hw->init->num_parents; | |
ac2df527 SN |
1925 | if (dev && dev->driver) |
1926 | clk->owner = dev->driver->owner; | |
1927 | else | |
1928 | clk->owner = NULL; | |
0197b3ea SK |
1929 | |
1930 | ret = __clk_init(dev, clk); | |
1931 | if (ret) | |
1932 | return ERR_PTR(ret); | |
1933 | ||
1934 | return clk; | |
1935 | } | |
1936 | EXPORT_SYMBOL_GPL(__clk_register); | |
1937 | ||
293ba3b4 SB |
1938 | /** |
1939 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
1940 | * @dev: device that is registering this clock | |
1941 | * @hw: link to hardware-specific clock data | |
1942 | * | |
1943 | * clk_register is the primary interface for populating the clock tree with new | |
1944 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
1945 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
1946 | * rest of the clock API. In the event of an error clk_register will return an | |
1947 | * error code; drivers must test for an error code after calling clk_register. | |
1948 | */ | |
1949 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
b2476490 | 1950 | { |
d1302a36 | 1951 | int i, ret; |
293ba3b4 SB |
1952 | struct clk *clk; |
1953 | ||
1954 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
1955 | if (!clk) { | |
1956 | pr_err("%s: could not allocate clk\n", __func__); | |
1957 | ret = -ENOMEM; | |
1958 | goto fail_out; | |
1959 | } | |
b2476490 | 1960 | |
0197b3ea SK |
1961 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
1962 | if (!clk->name) { | |
1963 | pr_err("%s: could not allocate clk->name\n", __func__); | |
1964 | ret = -ENOMEM; | |
1965 | goto fail_name; | |
1966 | } | |
1967 | clk->ops = hw->init->ops; | |
ac2df527 SN |
1968 | if (dev && dev->driver) |
1969 | clk->owner = dev->driver->owner; | |
b2476490 | 1970 | clk->hw = hw; |
0197b3ea SK |
1971 | clk->flags = hw->init->flags; |
1972 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
1973 | hw->clk = clk; |
1974 | ||
d1302a36 | 1975 | /* allocate local copy in case parent_names is __initdata */ |
96a7ed90 TF |
1976 | clk->parent_names = kcalloc(clk->num_parents, sizeof(char *), |
1977 | GFP_KERNEL); | |
d1302a36 MT |
1978 | |
1979 | if (!clk->parent_names) { | |
1980 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
1981 | ret = -ENOMEM; | |
1982 | goto fail_parent_names; | |
1983 | } | |
1984 | ||
1985 | ||
1986 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea SK |
1987 | for (i = 0; i < clk->num_parents; i++) { |
1988 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], | |
1989 | GFP_KERNEL); | |
d1302a36 MT |
1990 | if (!clk->parent_names[i]) { |
1991 | pr_err("%s: could not copy parent_names\n", __func__); | |
1992 | ret = -ENOMEM; | |
1993 | goto fail_parent_names_copy; | |
1994 | } | |
1995 | } | |
1996 | ||
1997 | ret = __clk_init(dev, clk); | |
1998 | if (!ret) | |
293ba3b4 | 1999 | return clk; |
b2476490 | 2000 | |
d1302a36 MT |
2001 | fail_parent_names_copy: |
2002 | while (--i >= 0) | |
2003 | kfree(clk->parent_names[i]); | |
2004 | kfree(clk->parent_names); | |
2005 | fail_parent_names: | |
0197b3ea SK |
2006 | kfree(clk->name); |
2007 | fail_name: | |
d1302a36 MT |
2008 | kfree(clk); |
2009 | fail_out: | |
2010 | return ERR_PTR(ret); | |
b2476490 MT |
2011 | } |
2012 | EXPORT_SYMBOL_GPL(clk_register); | |
2013 | ||
fcb0ee6a SN |
2014 | /* |
2015 | * Free memory allocated for a clock. | |
2016 | * Caller must hold prepare_lock. | |
2017 | */ | |
2018 | static void __clk_release(struct kref *ref) | |
2019 | { | |
2020 | struct clk *clk = container_of(ref, struct clk, ref); | |
2021 | int i = clk->num_parents; | |
2022 | ||
2023 | kfree(clk->parents); | |
2024 | while (--i >= 0) | |
2025 | kfree(clk->parent_names[i]); | |
2026 | ||
2027 | kfree(clk->parent_names); | |
2028 | kfree(clk->name); | |
2029 | kfree(clk); | |
2030 | } | |
2031 | ||
2032 | /* | |
2033 | * Empty clk_ops for unregistered clocks. These are used temporarily | |
2034 | * after clk_unregister() was called on a clock and until last clock | |
2035 | * consumer calls clk_put() and the struct clk object is freed. | |
2036 | */ | |
2037 | static int clk_nodrv_prepare_enable(struct clk_hw *hw) | |
2038 | { | |
2039 | return -ENXIO; | |
2040 | } | |
2041 | ||
2042 | static void clk_nodrv_disable_unprepare(struct clk_hw *hw) | |
2043 | { | |
2044 | WARN_ON_ONCE(1); | |
2045 | } | |
2046 | ||
2047 | static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, | |
2048 | unsigned long parent_rate) | |
2049 | { | |
2050 | return -ENXIO; | |
2051 | } | |
2052 | ||
2053 | static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) | |
2054 | { | |
2055 | return -ENXIO; | |
2056 | } | |
2057 | ||
2058 | static const struct clk_ops clk_nodrv_ops = { | |
2059 | .enable = clk_nodrv_prepare_enable, | |
2060 | .disable = clk_nodrv_disable_unprepare, | |
2061 | .prepare = clk_nodrv_prepare_enable, | |
2062 | .unprepare = clk_nodrv_disable_unprepare, | |
2063 | .set_rate = clk_nodrv_set_rate, | |
2064 | .set_parent = clk_nodrv_set_parent, | |
2065 | }; | |
2066 | ||
1df5c939 MB |
2067 | /** |
2068 | * clk_unregister - unregister a currently registered clock | |
2069 | * @clk: clock to unregister | |
1df5c939 | 2070 | */ |
fcb0ee6a SN |
2071 | void clk_unregister(struct clk *clk) |
2072 | { | |
2073 | unsigned long flags; | |
2074 | ||
2075 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) | |
2076 | return; | |
2077 | ||
2078 | clk_prepare_lock(); | |
2079 | ||
2080 | if (clk->ops == &clk_nodrv_ops) { | |
2081 | pr_err("%s: unregistered clock: %s\n", __func__, clk->name); | |
2082 | goto out; | |
2083 | } | |
2084 | /* | |
2085 | * Assign empty clock ops for consumers that might still hold | |
2086 | * a reference to this clock. | |
2087 | */ | |
2088 | flags = clk_enable_lock(); | |
2089 | clk->ops = &clk_nodrv_ops; | |
2090 | clk_enable_unlock(flags); | |
2091 | ||
2092 | if (!hlist_empty(&clk->children)) { | |
2093 | struct clk *child; | |
874f224c | 2094 | struct hlist_node *t; |
fcb0ee6a SN |
2095 | |
2096 | /* Reparent all children to the orphan list. */ | |
874f224c | 2097 | hlist_for_each_entry_safe(child, t, &clk->children, child_node) |
fcb0ee6a SN |
2098 | clk_set_parent(child, NULL); |
2099 | } | |
2100 | ||
2101 | clk_debug_unregister(clk); | |
2102 | ||
2103 | hlist_del_init(&clk->child_node); | |
2104 | ||
2105 | if (clk->prepare_count) | |
2106 | pr_warn("%s: unregistering prepared clock: %s\n", | |
2107 | __func__, clk->name); | |
2108 | ||
2109 | kref_put(&clk->ref, __clk_release); | |
2110 | out: | |
2111 | clk_prepare_unlock(); | |
2112 | } | |
1df5c939 MB |
2113 | EXPORT_SYMBOL_GPL(clk_unregister); |
2114 | ||
46c8773a SB |
2115 | static void devm_clk_release(struct device *dev, void *res) |
2116 | { | |
293ba3b4 | 2117 | clk_unregister(*(struct clk **)res); |
46c8773a SB |
2118 | } |
2119 | ||
2120 | /** | |
2121 | * devm_clk_register - resource managed clk_register() | |
2122 | * @dev: device that is registering this clock | |
2123 | * @hw: link to hardware-specific clock data | |
2124 | * | |
2125 | * Managed clk_register(). Clocks returned from this function are | |
2126 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
2127 | * more information. | |
2128 | */ | |
2129 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
2130 | { | |
2131 | struct clk *clk; | |
293ba3b4 | 2132 | struct clk **clkp; |
46c8773a | 2133 | |
293ba3b4 SB |
2134 | clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL); |
2135 | if (!clkp) | |
46c8773a SB |
2136 | return ERR_PTR(-ENOMEM); |
2137 | ||
293ba3b4 SB |
2138 | clk = clk_register(dev, hw); |
2139 | if (!IS_ERR(clk)) { | |
2140 | *clkp = clk; | |
2141 | devres_add(dev, clkp); | |
46c8773a | 2142 | } else { |
293ba3b4 | 2143 | devres_free(clkp); |
46c8773a SB |
2144 | } |
2145 | ||
2146 | return clk; | |
2147 | } | |
2148 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
2149 | ||
2150 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
2151 | { | |
2152 | struct clk *c = res; | |
2153 | if (WARN_ON(!c)) | |
2154 | return 0; | |
2155 | return c == data; | |
2156 | } | |
2157 | ||
2158 | /** | |
2159 | * devm_clk_unregister - resource managed clk_unregister() | |
2160 | * @clk: clock to unregister | |
2161 | * | |
2162 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
2163 | * this function will not need to be called and the resource management | |
2164 | * code will ensure that the resource is freed. | |
2165 | */ | |
2166 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
2167 | { | |
2168 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
2169 | } | |
2170 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
2171 | ||
ac2df527 SN |
2172 | /* |
2173 | * clkdev helpers | |
2174 | */ | |
2175 | int __clk_get(struct clk *clk) | |
2176 | { | |
00efcb1c SN |
2177 | if (clk) { |
2178 | if (!try_module_get(clk->owner)) | |
2179 | return 0; | |
ac2df527 | 2180 | |
00efcb1c SN |
2181 | kref_get(&clk->ref); |
2182 | } | |
ac2df527 SN |
2183 | return 1; |
2184 | } | |
2185 | ||
2186 | void __clk_put(struct clk *clk) | |
2187 | { | |
00efcb1c | 2188 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) |
ac2df527 SN |
2189 | return; |
2190 | ||
fcb0ee6a SN |
2191 | clk_prepare_lock(); |
2192 | kref_put(&clk->ref, __clk_release); | |
2193 | clk_prepare_unlock(); | |
2194 | ||
00efcb1c | 2195 | module_put(clk->owner); |
ac2df527 SN |
2196 | } |
2197 | ||
b2476490 MT |
2198 | /*** clk rate change notifiers ***/ |
2199 | ||
2200 | /** | |
2201 | * clk_notifier_register - add a clk rate change notifier | |
2202 | * @clk: struct clk * to watch | |
2203 | * @nb: struct notifier_block * with callback info | |
2204 | * | |
2205 | * Request notification when clk's rate changes. This uses an SRCU | |
2206 | * notifier because we want it to block and notifier unregistrations are | |
2207 | * uncommon. The callbacks associated with the notifier must not | |
2208 | * re-enter into the clk framework by calling any top-level clk APIs; | |
2209 | * this will cause a nested prepare_lock mutex. | |
2210 | * | |
5324fda7 SB |
2211 | * In all notification cases cases (pre, post and abort rate change) the |
2212 | * original clock rate is passed to the callback via struct | |
2213 | * clk_notifier_data.old_rate and the new frequency is passed via struct | |
b2476490 MT |
2214 | * clk_notifier_data.new_rate. |
2215 | * | |
b2476490 MT |
2216 | * clk_notifier_register() must be called from non-atomic context. |
2217 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
2218 | * allocation failure; otherwise, passes along the return value of | |
2219 | * srcu_notifier_chain_register(). | |
2220 | */ | |
2221 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
2222 | { | |
2223 | struct clk_notifier *cn; | |
2224 | int ret = -ENOMEM; | |
2225 | ||
2226 | if (!clk || !nb) | |
2227 | return -EINVAL; | |
2228 | ||
eab89f69 | 2229 | clk_prepare_lock(); |
b2476490 MT |
2230 | |
2231 | /* search the list of notifiers for this clk */ | |
2232 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2233 | if (cn->clk == clk) | |
2234 | break; | |
2235 | ||
2236 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
2237 | if (cn->clk != clk) { | |
2238 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
2239 | if (!cn) | |
2240 | goto out; | |
2241 | ||
2242 | cn->clk = clk; | |
2243 | srcu_init_notifier_head(&cn->notifier_head); | |
2244 | ||
2245 | list_add(&cn->node, &clk_notifier_list); | |
2246 | } | |
2247 | ||
2248 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
2249 | ||
2250 | clk->notifier_count++; | |
2251 | ||
2252 | out: | |
eab89f69 | 2253 | clk_prepare_unlock(); |
b2476490 MT |
2254 | |
2255 | return ret; | |
2256 | } | |
2257 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
2258 | ||
2259 | /** | |
2260 | * clk_notifier_unregister - remove a clk rate change notifier | |
2261 | * @clk: struct clk * | |
2262 | * @nb: struct notifier_block * with callback info | |
2263 | * | |
2264 | * Request no further notification for changes to 'clk' and frees memory | |
2265 | * allocated in clk_notifier_register. | |
2266 | * | |
2267 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
2268 | * along the return value of srcu_notifier_chain_unregister(). | |
2269 | */ | |
2270 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
2271 | { | |
2272 | struct clk_notifier *cn = NULL; | |
2273 | int ret = -EINVAL; | |
2274 | ||
2275 | if (!clk || !nb) | |
2276 | return -EINVAL; | |
2277 | ||
eab89f69 | 2278 | clk_prepare_lock(); |
b2476490 MT |
2279 | |
2280 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2281 | if (cn->clk == clk) | |
2282 | break; | |
2283 | ||
2284 | if (cn->clk == clk) { | |
2285 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
2286 | ||
2287 | clk->notifier_count--; | |
2288 | ||
2289 | /* XXX the notifier code should handle this better */ | |
2290 | if (!cn->notifier_head.head) { | |
2291 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
72b5322f | 2292 | list_del(&cn->node); |
b2476490 MT |
2293 | kfree(cn); |
2294 | } | |
2295 | ||
2296 | } else { | |
2297 | ret = -ENOENT; | |
2298 | } | |
2299 | ||
eab89f69 | 2300 | clk_prepare_unlock(); |
b2476490 MT |
2301 | |
2302 | return ret; | |
2303 | } | |
2304 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
2305 | |
2306 | #ifdef CONFIG_OF | |
2307 | /** | |
2308 | * struct of_clk_provider - Clock provider registration structure | |
2309 | * @link: Entry in global list of clock providers | |
2310 | * @node: Pointer to device tree node of clock provider | |
2311 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
2312 | * given clock specifier | |
2313 | * @data: context pointer to be passed into @get callback | |
2314 | */ | |
2315 | struct of_clk_provider { | |
2316 | struct list_head link; | |
2317 | ||
2318 | struct device_node *node; | |
2319 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
2320 | void *data; | |
2321 | }; | |
2322 | ||
f2f6c255 PG |
2323 | static const struct of_device_id __clk_of_table_sentinel |
2324 | __used __section(__clk_of_table_end); | |
2325 | ||
766e6a4e | 2326 | static LIST_HEAD(of_clk_providers); |
d6782c26 SN |
2327 | static DEFINE_MUTEX(of_clk_mutex); |
2328 | ||
2329 | /* of_clk_provider list locking helpers */ | |
2330 | void of_clk_lock(void) | |
2331 | { | |
2332 | mutex_lock(&of_clk_mutex); | |
2333 | } | |
2334 | ||
2335 | void of_clk_unlock(void) | |
2336 | { | |
2337 | mutex_unlock(&of_clk_mutex); | |
2338 | } | |
766e6a4e GL |
2339 | |
2340 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
2341 | void *data) | |
2342 | { | |
2343 | return data; | |
2344 | } | |
2345 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
2346 | ||
494bfec9 SG |
2347 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
2348 | { | |
2349 | struct clk_onecell_data *clk_data = data; | |
2350 | unsigned int idx = clkspec->args[0]; | |
2351 | ||
2352 | if (idx >= clk_data->clk_num) { | |
2353 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
2354 | return ERR_PTR(-EINVAL); | |
2355 | } | |
2356 | ||
2357 | return clk_data->clks[idx]; | |
2358 | } | |
2359 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
2360 | ||
766e6a4e GL |
2361 | /** |
2362 | * of_clk_add_provider() - Register a clock provider for a node | |
2363 | * @np: Device node pointer associated with clock provider | |
2364 | * @clk_src_get: callback for decoding clock | |
2365 | * @data: context pointer for @clk_src_get callback. | |
2366 | */ | |
2367 | int of_clk_add_provider(struct device_node *np, | |
2368 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
2369 | void *data), | |
2370 | void *data) | |
2371 | { | |
2372 | struct of_clk_provider *cp; | |
2373 | ||
2374 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
2375 | if (!cp) | |
2376 | return -ENOMEM; | |
2377 | ||
2378 | cp->node = of_node_get(np); | |
2379 | cp->data = data; | |
2380 | cp->get = clk_src_get; | |
2381 | ||
d6782c26 | 2382 | mutex_lock(&of_clk_mutex); |
766e6a4e | 2383 | list_add(&cp->link, &of_clk_providers); |
d6782c26 | 2384 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2385 | pr_debug("Added clock from %s\n", np->full_name); |
2386 | ||
2387 | return 0; | |
2388 | } | |
2389 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
2390 | ||
2391 | /** | |
2392 | * of_clk_del_provider() - Remove a previously registered clock provider | |
2393 | * @np: Device node pointer associated with clock provider | |
2394 | */ | |
2395 | void of_clk_del_provider(struct device_node *np) | |
2396 | { | |
2397 | struct of_clk_provider *cp; | |
2398 | ||
d6782c26 | 2399 | mutex_lock(&of_clk_mutex); |
766e6a4e GL |
2400 | list_for_each_entry(cp, &of_clk_providers, link) { |
2401 | if (cp->node == np) { | |
2402 | list_del(&cp->link); | |
2403 | of_node_put(cp->node); | |
2404 | kfree(cp); | |
2405 | break; | |
2406 | } | |
2407 | } | |
d6782c26 | 2408 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2409 | } |
2410 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
2411 | ||
d6782c26 | 2412 | struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) |
766e6a4e GL |
2413 | { |
2414 | struct of_clk_provider *provider; | |
a34cd466 | 2415 | struct clk *clk = ERR_PTR(-EPROBE_DEFER); |
766e6a4e GL |
2416 | |
2417 | /* Check if we have such a provider in our array */ | |
766e6a4e GL |
2418 | list_for_each_entry(provider, &of_clk_providers, link) { |
2419 | if (provider->node == clkspec->np) | |
2420 | clk = provider->get(clkspec, provider->data); | |
2421 | if (!IS_ERR(clk)) | |
2422 | break; | |
2423 | } | |
d6782c26 SN |
2424 | |
2425 | return clk; | |
2426 | } | |
2427 | ||
2428 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
2429 | { | |
2430 | struct clk *clk; | |
2431 | ||
2432 | mutex_lock(&of_clk_mutex); | |
2433 | clk = __of_clk_get_from_provider(clkspec); | |
2434 | mutex_unlock(&of_clk_mutex); | |
766e6a4e GL |
2435 | |
2436 | return clk; | |
2437 | } | |
2438 | ||
f6102742 MT |
2439 | int of_clk_get_parent_count(struct device_node *np) |
2440 | { | |
2441 | return of_count_phandle_with_args(np, "clocks", "#clock-cells"); | |
2442 | } | |
2443 | EXPORT_SYMBOL_GPL(of_clk_get_parent_count); | |
2444 | ||
766e6a4e GL |
2445 | const char *of_clk_get_parent_name(struct device_node *np, int index) |
2446 | { | |
2447 | struct of_phandle_args clkspec; | |
7a0fc1a3 | 2448 | struct property *prop; |
766e6a4e | 2449 | const char *clk_name; |
7a0fc1a3 BD |
2450 | const __be32 *vp; |
2451 | u32 pv; | |
766e6a4e | 2452 | int rc; |
7a0fc1a3 | 2453 | int count; |
766e6a4e GL |
2454 | |
2455 | if (index < 0) | |
2456 | return NULL; | |
2457 | ||
2458 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
2459 | &clkspec); | |
2460 | if (rc) | |
2461 | return NULL; | |
2462 | ||
7a0fc1a3 BD |
2463 | index = clkspec.args_count ? clkspec.args[0] : 0; |
2464 | count = 0; | |
2465 | ||
2466 | /* if there is an indices property, use it to transfer the index | |
2467 | * specified into an array offset for the clock-output-names property. | |
2468 | */ | |
2469 | of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) { | |
2470 | if (index == pv) { | |
2471 | index = count; | |
2472 | break; | |
2473 | } | |
2474 | count++; | |
2475 | } | |
2476 | ||
766e6a4e | 2477 | if (of_property_read_string_index(clkspec.np, "clock-output-names", |
7a0fc1a3 | 2478 | index, |
766e6a4e GL |
2479 | &clk_name) < 0) |
2480 | clk_name = clkspec.np->name; | |
2481 | ||
2482 | of_node_put(clkspec.np); | |
2483 | return clk_name; | |
2484 | } | |
2485 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
2486 | ||
1771b10d GC |
2487 | struct clock_provider { |
2488 | of_clk_init_cb_t clk_init_cb; | |
2489 | struct device_node *np; | |
2490 | struct list_head node; | |
2491 | }; | |
2492 | ||
2493 | static LIST_HEAD(clk_provider_list); | |
2494 | ||
2495 | /* | |
2496 | * This function looks for a parent clock. If there is one, then it | |
2497 | * checks that the provider for this parent clock was initialized, in | |
2498 | * this case the parent clock will be ready. | |
2499 | */ | |
2500 | static int parent_ready(struct device_node *np) | |
2501 | { | |
2502 | int i = 0; | |
2503 | ||
2504 | while (true) { | |
2505 | struct clk *clk = of_clk_get(np, i); | |
2506 | ||
2507 | /* this parent is ready we can check the next one */ | |
2508 | if (!IS_ERR(clk)) { | |
2509 | clk_put(clk); | |
2510 | i++; | |
2511 | continue; | |
2512 | } | |
2513 | ||
2514 | /* at least one parent is not ready, we exit now */ | |
2515 | if (PTR_ERR(clk) == -EPROBE_DEFER) | |
2516 | return 0; | |
2517 | ||
2518 | /* | |
2519 | * Here we make assumption that the device tree is | |
2520 | * written correctly. So an error means that there is | |
2521 | * no more parent. As we didn't exit yet, then the | |
2522 | * previous parent are ready. If there is no clock | |
2523 | * parent, no need to wait for them, then we can | |
2524 | * consider their absence as being ready | |
2525 | */ | |
2526 | return 1; | |
2527 | } | |
2528 | } | |
2529 | ||
766e6a4e GL |
2530 | /** |
2531 | * of_clk_init() - Scan and init clock providers from the DT | |
2532 | * @matches: array of compatible values and init functions for providers. | |
2533 | * | |
1771b10d | 2534 | * This function scans the device tree for matching clock providers |
e5ca8fb4 | 2535 | * and calls their initialization functions. It also does it by trying |
1771b10d | 2536 | * to follow the dependencies. |
766e6a4e GL |
2537 | */ |
2538 | void __init of_clk_init(const struct of_device_id *matches) | |
2539 | { | |
7f7ed584 | 2540 | const struct of_device_id *match; |
766e6a4e | 2541 | struct device_node *np; |
1771b10d GC |
2542 | struct clock_provider *clk_provider, *next; |
2543 | bool is_init_done; | |
2544 | bool force = false; | |
766e6a4e | 2545 | |
f2f6c255 | 2546 | if (!matches) |
819b4861 | 2547 | matches = &__clk_of_table; |
f2f6c255 | 2548 | |
1771b10d | 2549 | /* First prepare the list of the clocks providers */ |
7f7ed584 | 2550 | for_each_matching_node_and_match(np, matches, &match) { |
1771b10d GC |
2551 | struct clock_provider *parent = |
2552 | kzalloc(sizeof(struct clock_provider), GFP_KERNEL); | |
2553 | ||
2554 | parent->clk_init_cb = match->data; | |
2555 | parent->np = np; | |
3f6d439f | 2556 | list_add_tail(&parent->node, &clk_provider_list); |
1771b10d GC |
2557 | } |
2558 | ||
2559 | while (!list_empty(&clk_provider_list)) { | |
2560 | is_init_done = false; | |
2561 | list_for_each_entry_safe(clk_provider, next, | |
2562 | &clk_provider_list, node) { | |
2563 | if (force || parent_ready(clk_provider->np)) { | |
2564 | clk_provider->clk_init_cb(clk_provider->np); | |
2565 | list_del(&clk_provider->node); | |
2566 | kfree(clk_provider); | |
2567 | is_init_done = true; | |
2568 | } | |
2569 | } | |
2570 | ||
2571 | /* | |
e5ca8fb4 | 2572 | * We didn't manage to initialize any of the |
1771b10d GC |
2573 | * remaining providers during the last loop, so now we |
2574 | * initialize all the remaining ones unconditionally | |
2575 | * in case the clock parent was not mandatory | |
2576 | */ | |
2577 | if (!is_init_done) | |
2578 | force = true; | |
2579 | ||
766e6a4e GL |
2580 | } |
2581 | } | |
2582 | #endif |