Commit | Line | Data |
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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> | |
86be408b | 13 | #include <linux/clk/clk-conf.h> |
b2476490 MT |
14 | #include <linux/module.h> |
15 | #include <linux/mutex.h> | |
16 | #include <linux/spinlock.h> | |
17 | #include <linux/err.h> | |
18 | #include <linux/list.h> | |
19 | #include <linux/slab.h> | |
766e6a4e | 20 | #include <linux/of.h> |
46c8773a | 21 | #include <linux/device.h> |
f2f6c255 | 22 | #include <linux/init.h> |
533ddeb1 | 23 | #include <linux/sched.h> |
b2476490 | 24 | |
d6782c26 SN |
25 | #include "clk.h" |
26 | ||
b2476490 MT |
27 | static DEFINE_SPINLOCK(enable_lock); |
28 | static DEFINE_MUTEX(prepare_lock); | |
29 | ||
533ddeb1 MT |
30 | static struct task_struct *prepare_owner; |
31 | static struct task_struct *enable_owner; | |
32 | ||
33 | static int prepare_refcnt; | |
34 | static int enable_refcnt; | |
35 | ||
b2476490 MT |
36 | static HLIST_HEAD(clk_root_list); |
37 | static HLIST_HEAD(clk_orphan_list); | |
38 | static LIST_HEAD(clk_notifier_list); | |
39 | ||
eab89f69 MT |
40 | /*** locking ***/ |
41 | static void clk_prepare_lock(void) | |
42 | { | |
533ddeb1 MT |
43 | if (!mutex_trylock(&prepare_lock)) { |
44 | if (prepare_owner == current) { | |
45 | prepare_refcnt++; | |
46 | return; | |
47 | } | |
48 | mutex_lock(&prepare_lock); | |
49 | } | |
50 | WARN_ON_ONCE(prepare_owner != NULL); | |
51 | WARN_ON_ONCE(prepare_refcnt != 0); | |
52 | prepare_owner = current; | |
53 | prepare_refcnt = 1; | |
eab89f69 MT |
54 | } |
55 | ||
56 | static void clk_prepare_unlock(void) | |
57 | { | |
533ddeb1 MT |
58 | WARN_ON_ONCE(prepare_owner != current); |
59 | WARN_ON_ONCE(prepare_refcnt == 0); | |
60 | ||
61 | if (--prepare_refcnt) | |
62 | return; | |
63 | prepare_owner = NULL; | |
eab89f69 MT |
64 | mutex_unlock(&prepare_lock); |
65 | } | |
66 | ||
67 | static unsigned long clk_enable_lock(void) | |
68 | { | |
69 | unsigned long flags; | |
533ddeb1 MT |
70 | |
71 | if (!spin_trylock_irqsave(&enable_lock, flags)) { | |
72 | if (enable_owner == current) { | |
73 | enable_refcnt++; | |
74 | return flags; | |
75 | } | |
76 | spin_lock_irqsave(&enable_lock, flags); | |
77 | } | |
78 | WARN_ON_ONCE(enable_owner != NULL); | |
79 | WARN_ON_ONCE(enable_refcnt != 0); | |
80 | enable_owner = current; | |
81 | enable_refcnt = 1; | |
eab89f69 MT |
82 | return flags; |
83 | } | |
84 | ||
85 | static void clk_enable_unlock(unsigned long flags) | |
86 | { | |
533ddeb1 MT |
87 | WARN_ON_ONCE(enable_owner != current); |
88 | WARN_ON_ONCE(enable_refcnt == 0); | |
89 | ||
90 | if (--enable_refcnt) | |
91 | return; | |
92 | enable_owner = NULL; | |
eab89f69 MT |
93 | spin_unlock_irqrestore(&enable_lock, flags); |
94 | } | |
95 | ||
b2476490 MT |
96 | /*** debugfs support ***/ |
97 | ||
ea72dc2c | 98 | #ifdef CONFIG_DEBUG_FS |
b2476490 MT |
99 | #include <linux/debugfs.h> |
100 | ||
101 | static struct dentry *rootdir; | |
b2476490 MT |
102 | static int inited = 0; |
103 | ||
6b44c854 SK |
104 | static struct hlist_head *all_lists[] = { |
105 | &clk_root_list, | |
106 | &clk_orphan_list, | |
107 | NULL, | |
108 | }; | |
109 | ||
110 | static struct hlist_head *orphan_list[] = { | |
111 | &clk_orphan_list, | |
112 | NULL, | |
113 | }; | |
114 | ||
1af599df PG |
115 | static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level) |
116 | { | |
117 | if (!c) | |
118 | return; | |
119 | ||
fb8abb7a | 120 | seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu\n", |
1af599df PG |
121 | level * 3 + 1, "", |
122 | 30 - level * 3, c->name, | |
5279fc40 BB |
123 | c->enable_count, c->prepare_count, clk_get_rate(c), |
124 | clk_get_accuracy(c)); | |
1af599df PG |
125 | } |
126 | ||
127 | static void clk_summary_show_subtree(struct seq_file *s, struct clk *c, | |
128 | int level) | |
129 | { | |
130 | struct clk *child; | |
1af599df PG |
131 | |
132 | if (!c) | |
133 | return; | |
134 | ||
135 | clk_summary_show_one(s, c, level); | |
136 | ||
b67bfe0d | 137 | hlist_for_each_entry(child, &c->children, child_node) |
1af599df PG |
138 | clk_summary_show_subtree(s, child, level + 1); |
139 | } | |
140 | ||
141 | static int clk_summary_show(struct seq_file *s, void *data) | |
142 | { | |
143 | struct clk *c; | |
27b8d5f7 | 144 | struct hlist_head **lists = (struct hlist_head **)s->private; |
1af599df | 145 | |
fb8abb7a GU |
146 | seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy\n"); |
147 | seq_puts(s, "--------------------------------------------------------------------------------\n"); | |
1af599df | 148 | |
eab89f69 | 149 | clk_prepare_lock(); |
1af599df | 150 | |
27b8d5f7 PDS |
151 | for (; *lists; lists++) |
152 | hlist_for_each_entry(c, *lists, child_node) | |
153 | clk_summary_show_subtree(s, c, 0); | |
1af599df | 154 | |
eab89f69 | 155 | clk_prepare_unlock(); |
1af599df PG |
156 | |
157 | return 0; | |
158 | } | |
159 | ||
160 | ||
161 | static int clk_summary_open(struct inode *inode, struct file *file) | |
162 | { | |
163 | return single_open(file, clk_summary_show, inode->i_private); | |
164 | } | |
165 | ||
166 | static const struct file_operations clk_summary_fops = { | |
167 | .open = clk_summary_open, | |
168 | .read = seq_read, | |
169 | .llseek = seq_lseek, | |
170 | .release = single_release, | |
171 | }; | |
172 | ||
bddca894 PG |
173 | static void clk_dump_one(struct seq_file *s, struct clk *c, int level) |
174 | { | |
175 | if (!c) | |
176 | return; | |
177 | ||
178 | seq_printf(s, "\"%s\": { ", c->name); | |
179 | seq_printf(s, "\"enable_count\": %d,", c->enable_count); | |
180 | seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); | |
670decdd | 181 | seq_printf(s, "\"rate\": %lu", clk_get_rate(c)); |
5279fc40 | 182 | seq_printf(s, "\"accuracy\": %lu", clk_get_accuracy(c)); |
bddca894 PG |
183 | } |
184 | ||
185 | static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) | |
186 | { | |
187 | struct clk *child; | |
bddca894 PG |
188 | |
189 | if (!c) | |
190 | return; | |
191 | ||
192 | clk_dump_one(s, c, level); | |
193 | ||
b67bfe0d | 194 | hlist_for_each_entry(child, &c->children, child_node) { |
bddca894 PG |
195 | seq_printf(s, ","); |
196 | clk_dump_subtree(s, child, level + 1); | |
197 | } | |
198 | ||
199 | seq_printf(s, "}"); | |
200 | } | |
201 | ||
202 | static int clk_dump(struct seq_file *s, void *data) | |
203 | { | |
204 | struct clk *c; | |
bddca894 | 205 | bool first_node = true; |
27b8d5f7 | 206 | struct hlist_head **lists = (struct hlist_head **)s->private; |
bddca894 PG |
207 | |
208 | seq_printf(s, "{"); | |
209 | ||
eab89f69 | 210 | clk_prepare_lock(); |
bddca894 | 211 | |
27b8d5f7 PDS |
212 | for (; *lists; lists++) { |
213 | hlist_for_each_entry(c, *lists, child_node) { | |
214 | if (!first_node) | |
215 | seq_puts(s, ","); | |
216 | first_node = false; | |
217 | clk_dump_subtree(s, c, 0); | |
218 | } | |
bddca894 PG |
219 | } |
220 | ||
eab89f69 | 221 | clk_prepare_unlock(); |
bddca894 PG |
222 | |
223 | seq_printf(s, "}"); | |
224 | return 0; | |
225 | } | |
226 | ||
227 | ||
228 | static int clk_dump_open(struct inode *inode, struct file *file) | |
229 | { | |
230 | return single_open(file, clk_dump, inode->i_private); | |
231 | } | |
232 | ||
233 | static const struct file_operations clk_dump_fops = { | |
234 | .open = clk_dump_open, | |
235 | .read = seq_read, | |
236 | .llseek = seq_lseek, | |
237 | .release = single_release, | |
238 | }; | |
239 | ||
b2476490 MT |
240 | /* caller must hold prepare_lock */ |
241 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) | |
242 | { | |
243 | struct dentry *d; | |
244 | int ret = -ENOMEM; | |
245 | ||
246 | if (!clk || !pdentry) { | |
247 | ret = -EINVAL; | |
248 | goto out; | |
249 | } | |
250 | ||
251 | d = debugfs_create_dir(clk->name, pdentry); | |
252 | if (!d) | |
253 | goto out; | |
254 | ||
255 | clk->dentry = d; | |
256 | ||
257 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, | |
258 | (u32 *)&clk->rate); | |
259 | if (!d) | |
260 | goto err_out; | |
261 | ||
5279fc40 BB |
262 | d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry, |
263 | (u32 *)&clk->accuracy); | |
264 | if (!d) | |
265 | goto err_out; | |
266 | ||
b2476490 MT |
267 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, |
268 | (u32 *)&clk->flags); | |
269 | if (!d) | |
270 | goto err_out; | |
271 | ||
272 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, | |
273 | (u32 *)&clk->prepare_count); | |
274 | if (!d) | |
275 | goto err_out; | |
276 | ||
277 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, | |
278 | (u32 *)&clk->enable_count); | |
279 | if (!d) | |
280 | goto err_out; | |
281 | ||
282 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, | |
283 | (u32 *)&clk->notifier_count); | |
284 | if (!d) | |
285 | goto err_out; | |
286 | ||
abeab450 CB |
287 | if (clk->ops->debug_init) { |
288 | ret = clk->ops->debug_init(clk->hw, clk->dentry); | |
289 | if (ret) | |
c646cbf1 | 290 | goto err_out; |
abeab450 | 291 | } |
c646cbf1 | 292 | |
b2476490 MT |
293 | ret = 0; |
294 | goto out; | |
295 | ||
296 | err_out: | |
b5f98e65 AE |
297 | debugfs_remove_recursive(clk->dentry); |
298 | clk->dentry = NULL; | |
b2476490 MT |
299 | out: |
300 | return ret; | |
301 | } | |
302 | ||
303 | /* caller must hold prepare_lock */ | |
304 | static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry) | |
305 | { | |
306 | struct clk *child; | |
b2476490 MT |
307 | int ret = -EINVAL;; |
308 | ||
309 | if (!clk || !pdentry) | |
310 | goto out; | |
311 | ||
312 | ret = clk_debug_create_one(clk, pdentry); | |
313 | ||
314 | if (ret) | |
315 | goto out; | |
316 | ||
b67bfe0d | 317 | hlist_for_each_entry(child, &clk->children, child_node) |
27b8d5f7 | 318 | clk_debug_create_subtree(child, pdentry); |
b2476490 MT |
319 | |
320 | ret = 0; | |
321 | out: | |
322 | return ret; | |
323 | } | |
324 | ||
325 | /** | |
326 | * clk_debug_register - add a clk node to the debugfs clk tree | |
327 | * @clk: the clk being added to the debugfs clk tree | |
328 | * | |
329 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been | |
330 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
331 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
332 | * | |
333 | * Caller must hold prepare_lock. Only clk_init calls this function (so | |
334 | * far) so this is taken care. | |
335 | */ | |
336 | static int clk_debug_register(struct clk *clk) | |
337 | { | |
b2476490 MT |
338 | int ret = 0; |
339 | ||
340 | if (!inited) | |
341 | goto out; | |
342 | ||
27b8d5f7 | 343 | ret = clk_debug_create_subtree(clk, rootdir); |
b2476490 MT |
344 | |
345 | out: | |
346 | return ret; | |
347 | } | |
348 | ||
fcb0ee6a SN |
349 | /** |
350 | * clk_debug_unregister - remove a clk node from the debugfs clk tree | |
351 | * @clk: the clk being removed from the debugfs clk tree | |
352 | * | |
353 | * Dynamically removes a clk and all it's children clk nodes from the | |
354 | * debugfs clk tree if clk->dentry points to debugfs created by | |
355 | * clk_debug_register in __clk_init. | |
356 | * | |
357 | * Caller must hold prepare_lock. | |
358 | */ | |
359 | static void clk_debug_unregister(struct clk *clk) | |
360 | { | |
361 | debugfs_remove_recursive(clk->dentry); | |
362 | } | |
363 | ||
fb2b3c9f PDS |
364 | struct dentry *clk_debugfs_add_file(struct clk *clk, char *name, umode_t mode, |
365 | void *data, const struct file_operations *fops) | |
366 | { | |
367 | struct dentry *d = NULL; | |
368 | ||
369 | if (clk->dentry) | |
370 | d = debugfs_create_file(name, mode, clk->dentry, data, fops); | |
371 | ||
372 | return d; | |
373 | } | |
374 | EXPORT_SYMBOL_GPL(clk_debugfs_add_file); | |
375 | ||
b2476490 MT |
376 | /** |
377 | * clk_debug_init - lazily create the debugfs clk tree visualization | |
378 | * | |
379 | * clks are often initialized very early during boot before memory can | |
380 | * be dynamically allocated and well before debugfs is setup. | |
381 | * clk_debug_init walks the clk tree hierarchy while holding | |
382 | * prepare_lock and creates the topology as part of a late_initcall, | |
383 | * thus insuring that clks initialized very early will still be | |
384 | * represented in the debugfs clk tree. This function should only be | |
385 | * called once at boot-time, and all other clks added dynamically will | |
386 | * be done so with clk_debug_register. | |
387 | */ | |
388 | static int __init clk_debug_init(void) | |
389 | { | |
390 | struct clk *clk; | |
1af599df | 391 | struct dentry *d; |
b2476490 MT |
392 | |
393 | rootdir = debugfs_create_dir("clk", NULL); | |
394 | ||
395 | if (!rootdir) | |
396 | return -ENOMEM; | |
397 | ||
27b8d5f7 | 398 | d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists, |
1af599df PG |
399 | &clk_summary_fops); |
400 | if (!d) | |
401 | return -ENOMEM; | |
402 | ||
27b8d5f7 | 403 | d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists, |
bddca894 PG |
404 | &clk_dump_fops); |
405 | if (!d) | |
406 | return -ENOMEM; | |
407 | ||
27b8d5f7 PDS |
408 | d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir, |
409 | &orphan_list, &clk_summary_fops); | |
410 | if (!d) | |
411 | return -ENOMEM; | |
b2476490 | 412 | |
27b8d5f7 PDS |
413 | d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir, |
414 | &orphan_list, &clk_dump_fops); | |
415 | if (!d) | |
b2476490 MT |
416 | return -ENOMEM; |
417 | ||
eab89f69 | 418 | clk_prepare_lock(); |
b2476490 | 419 | |
b67bfe0d | 420 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
421 | clk_debug_create_subtree(clk, rootdir); |
422 | ||
b67bfe0d | 423 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
27b8d5f7 | 424 | clk_debug_create_subtree(clk, rootdir); |
b2476490 MT |
425 | |
426 | inited = 1; | |
427 | ||
eab89f69 | 428 | clk_prepare_unlock(); |
b2476490 MT |
429 | |
430 | return 0; | |
431 | } | |
432 | late_initcall(clk_debug_init); | |
433 | #else | |
434 | static inline int clk_debug_register(struct clk *clk) { return 0; } | |
b33d212f UH |
435 | static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent) |
436 | { | |
437 | } | |
fcb0ee6a SN |
438 | static inline void clk_debug_unregister(struct clk *clk) |
439 | { | |
440 | } | |
70d347e6 | 441 | #endif |
b2476490 | 442 | |
1c155b3d UH |
443 | /* caller must hold prepare_lock */ |
444 | static void clk_unprepare_unused_subtree(struct clk *clk) | |
445 | { | |
446 | struct clk *child; | |
447 | ||
448 | if (!clk) | |
449 | return; | |
450 | ||
451 | hlist_for_each_entry(child, &clk->children, child_node) | |
452 | clk_unprepare_unused_subtree(child); | |
453 | ||
454 | if (clk->prepare_count) | |
455 | return; | |
456 | ||
457 | if (clk->flags & CLK_IGNORE_UNUSED) | |
458 | return; | |
459 | ||
3cc8247f UH |
460 | if (__clk_is_prepared(clk)) { |
461 | if (clk->ops->unprepare_unused) | |
462 | clk->ops->unprepare_unused(clk->hw); | |
463 | else if (clk->ops->unprepare) | |
1c155b3d | 464 | clk->ops->unprepare(clk->hw); |
3cc8247f | 465 | } |
1c155b3d UH |
466 | } |
467 | ||
b2476490 MT |
468 | /* caller must hold prepare_lock */ |
469 | static void clk_disable_unused_subtree(struct clk *clk) | |
470 | { | |
471 | struct clk *child; | |
b2476490 MT |
472 | unsigned long flags; |
473 | ||
474 | if (!clk) | |
475 | goto out; | |
476 | ||
b67bfe0d | 477 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
478 | clk_disable_unused_subtree(child); |
479 | ||
eab89f69 | 480 | flags = clk_enable_lock(); |
b2476490 MT |
481 | |
482 | if (clk->enable_count) | |
483 | goto unlock_out; | |
484 | ||
485 | if (clk->flags & CLK_IGNORE_UNUSED) | |
486 | goto unlock_out; | |
487 | ||
7c045a55 MT |
488 | /* |
489 | * some gate clocks have special needs during the disable-unused | |
490 | * sequence. call .disable_unused if available, otherwise fall | |
491 | * back to .disable | |
492 | */ | |
493 | if (__clk_is_enabled(clk)) { | |
494 | if (clk->ops->disable_unused) | |
495 | clk->ops->disable_unused(clk->hw); | |
496 | else if (clk->ops->disable) | |
497 | clk->ops->disable(clk->hw); | |
498 | } | |
b2476490 MT |
499 | |
500 | unlock_out: | |
eab89f69 | 501 | clk_enable_unlock(flags); |
b2476490 MT |
502 | |
503 | out: | |
504 | return; | |
505 | } | |
506 | ||
1e435256 OJ |
507 | static bool clk_ignore_unused; |
508 | static int __init clk_ignore_unused_setup(char *__unused) | |
509 | { | |
510 | clk_ignore_unused = true; | |
511 | return 1; | |
512 | } | |
513 | __setup("clk_ignore_unused", clk_ignore_unused_setup); | |
514 | ||
b2476490 MT |
515 | static int clk_disable_unused(void) |
516 | { | |
517 | struct clk *clk; | |
b2476490 | 518 | |
1e435256 OJ |
519 | if (clk_ignore_unused) { |
520 | pr_warn("clk: Not disabling unused clocks\n"); | |
521 | return 0; | |
522 | } | |
523 | ||
eab89f69 | 524 | clk_prepare_lock(); |
b2476490 | 525 | |
b67bfe0d | 526 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
527 | clk_disable_unused_subtree(clk); |
528 | ||
b67bfe0d | 529 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
b2476490 MT |
530 | clk_disable_unused_subtree(clk); |
531 | ||
1c155b3d UH |
532 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
533 | clk_unprepare_unused_subtree(clk); | |
534 | ||
535 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) | |
536 | clk_unprepare_unused_subtree(clk); | |
537 | ||
eab89f69 | 538 | clk_prepare_unlock(); |
b2476490 MT |
539 | |
540 | return 0; | |
541 | } | |
d41d5805 | 542 | late_initcall_sync(clk_disable_unused); |
b2476490 MT |
543 | |
544 | /*** helper functions ***/ | |
545 | ||
65800b2c | 546 | const char *__clk_get_name(struct clk *clk) |
b2476490 MT |
547 | { |
548 | return !clk ? NULL : clk->name; | |
549 | } | |
4895084c | 550 | EXPORT_SYMBOL_GPL(__clk_get_name); |
b2476490 | 551 | |
65800b2c | 552 | struct clk_hw *__clk_get_hw(struct clk *clk) |
b2476490 MT |
553 | { |
554 | return !clk ? NULL : clk->hw; | |
555 | } | |
0b7f04b8 | 556 | EXPORT_SYMBOL_GPL(__clk_get_hw); |
b2476490 | 557 | |
65800b2c | 558 | u8 __clk_get_num_parents(struct clk *clk) |
b2476490 | 559 | { |
2ac6b1f5 | 560 | return !clk ? 0 : clk->num_parents; |
b2476490 | 561 | } |
0b7f04b8 | 562 | EXPORT_SYMBOL_GPL(__clk_get_num_parents); |
b2476490 | 563 | |
65800b2c | 564 | struct clk *__clk_get_parent(struct clk *clk) |
b2476490 MT |
565 | { |
566 | return !clk ? NULL : clk->parent; | |
567 | } | |
0b7f04b8 | 568 | EXPORT_SYMBOL_GPL(__clk_get_parent); |
b2476490 | 569 | |
7ef3dcc8 JH |
570 | struct clk *clk_get_parent_by_index(struct clk *clk, u8 index) |
571 | { | |
572 | if (!clk || index >= clk->num_parents) | |
573 | return NULL; | |
574 | else if (!clk->parents) | |
575 | return __clk_lookup(clk->parent_names[index]); | |
576 | else if (!clk->parents[index]) | |
577 | return clk->parents[index] = | |
578 | __clk_lookup(clk->parent_names[index]); | |
579 | else | |
580 | return clk->parents[index]; | |
581 | } | |
0b7f04b8 | 582 | EXPORT_SYMBOL_GPL(clk_get_parent_by_index); |
7ef3dcc8 | 583 | |
65800b2c | 584 | unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 585 | { |
2ac6b1f5 | 586 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
587 | } |
588 | ||
65800b2c | 589 | unsigned int __clk_get_prepare_count(struct clk *clk) |
b2476490 | 590 | { |
2ac6b1f5 | 591 | return !clk ? 0 : clk->prepare_count; |
b2476490 MT |
592 | } |
593 | ||
594 | unsigned long __clk_get_rate(struct clk *clk) | |
595 | { | |
596 | unsigned long ret; | |
597 | ||
598 | if (!clk) { | |
34e44fe8 | 599 | ret = 0; |
b2476490 MT |
600 | goto out; |
601 | } | |
602 | ||
603 | ret = clk->rate; | |
604 | ||
605 | if (clk->flags & CLK_IS_ROOT) | |
606 | goto out; | |
607 | ||
608 | if (!clk->parent) | |
34e44fe8 | 609 | ret = 0; |
b2476490 MT |
610 | |
611 | out: | |
612 | return ret; | |
613 | } | |
0b7f04b8 | 614 | EXPORT_SYMBOL_GPL(__clk_get_rate); |
b2476490 | 615 | |
5279fc40 BB |
616 | unsigned long __clk_get_accuracy(struct clk *clk) |
617 | { | |
618 | if (!clk) | |
619 | return 0; | |
620 | ||
621 | return clk->accuracy; | |
622 | } | |
623 | ||
65800b2c | 624 | unsigned long __clk_get_flags(struct clk *clk) |
b2476490 | 625 | { |
2ac6b1f5 | 626 | return !clk ? 0 : clk->flags; |
b2476490 | 627 | } |
b05c6836 | 628 | EXPORT_SYMBOL_GPL(__clk_get_flags); |
b2476490 | 629 | |
3d6ee287 UH |
630 | bool __clk_is_prepared(struct clk *clk) |
631 | { | |
632 | int ret; | |
633 | ||
634 | if (!clk) | |
635 | return false; | |
636 | ||
637 | /* | |
638 | * .is_prepared is optional for clocks that can prepare | |
639 | * fall back to software usage counter if it is missing | |
640 | */ | |
641 | if (!clk->ops->is_prepared) { | |
642 | ret = clk->prepare_count ? 1 : 0; | |
643 | goto out; | |
644 | } | |
645 | ||
646 | ret = clk->ops->is_prepared(clk->hw); | |
647 | out: | |
648 | return !!ret; | |
649 | } | |
650 | ||
2ac6b1f5 | 651 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
652 | { |
653 | int ret; | |
654 | ||
655 | if (!clk) | |
2ac6b1f5 | 656 | return false; |
b2476490 MT |
657 | |
658 | /* | |
659 | * .is_enabled is only mandatory for clocks that gate | |
660 | * fall back to software usage counter if .is_enabled is missing | |
661 | */ | |
662 | if (!clk->ops->is_enabled) { | |
663 | ret = clk->enable_count ? 1 : 0; | |
664 | goto out; | |
665 | } | |
666 | ||
667 | ret = clk->ops->is_enabled(clk->hw); | |
668 | out: | |
2ac6b1f5 | 669 | return !!ret; |
b2476490 | 670 | } |
0b7f04b8 | 671 | EXPORT_SYMBOL_GPL(__clk_is_enabled); |
b2476490 MT |
672 | |
673 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
674 | { | |
675 | struct clk *child; | |
676 | struct clk *ret; | |
b2476490 MT |
677 | |
678 | if (!strcmp(clk->name, name)) | |
679 | return clk; | |
680 | ||
b67bfe0d | 681 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
682 | ret = __clk_lookup_subtree(name, child); |
683 | if (ret) | |
684 | return ret; | |
685 | } | |
686 | ||
687 | return NULL; | |
688 | } | |
689 | ||
690 | struct clk *__clk_lookup(const char *name) | |
691 | { | |
692 | struct clk *root_clk; | |
693 | struct clk *ret; | |
b2476490 MT |
694 | |
695 | if (!name) | |
696 | return NULL; | |
697 | ||
698 | /* search the 'proper' clk tree first */ | |
b67bfe0d | 699 | hlist_for_each_entry(root_clk, &clk_root_list, child_node) { |
b2476490 MT |
700 | ret = __clk_lookup_subtree(name, root_clk); |
701 | if (ret) | |
702 | return ret; | |
703 | } | |
704 | ||
705 | /* if not found, then search the orphan tree */ | |
b67bfe0d | 706 | hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { |
b2476490 MT |
707 | ret = __clk_lookup_subtree(name, root_clk); |
708 | if (ret) | |
709 | return ret; | |
710 | } | |
711 | ||
712 | return NULL; | |
713 | } | |
714 | ||
e366fdd7 JH |
715 | /* |
716 | * Helper for finding best parent to provide a given frequency. This can be used | |
717 | * directly as a determine_rate callback (e.g. for a mux), or from a more | |
718 | * complex clock that may combine a mux with other operations. | |
719 | */ | |
720 | long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, | |
721 | unsigned long *best_parent_rate, | |
722 | struct clk **best_parent_p) | |
723 | { | |
724 | struct clk *clk = hw->clk, *parent, *best_parent = NULL; | |
725 | int i, num_parents; | |
726 | unsigned long parent_rate, best = 0; | |
727 | ||
728 | /* if NO_REPARENT flag set, pass through to current parent */ | |
729 | if (clk->flags & CLK_SET_RATE_NO_REPARENT) { | |
730 | parent = clk->parent; | |
731 | if (clk->flags & CLK_SET_RATE_PARENT) | |
732 | best = __clk_round_rate(parent, rate); | |
733 | else if (parent) | |
734 | best = __clk_get_rate(parent); | |
735 | else | |
736 | best = __clk_get_rate(clk); | |
737 | goto out; | |
738 | } | |
739 | ||
740 | /* find the parent that can provide the fastest rate <= rate */ | |
741 | num_parents = clk->num_parents; | |
742 | for (i = 0; i < num_parents; i++) { | |
743 | parent = clk_get_parent_by_index(clk, i); | |
744 | if (!parent) | |
745 | continue; | |
746 | if (clk->flags & CLK_SET_RATE_PARENT) | |
747 | parent_rate = __clk_round_rate(parent, rate); | |
748 | else | |
749 | parent_rate = __clk_get_rate(parent); | |
750 | if (parent_rate <= rate && parent_rate > best) { | |
751 | best_parent = parent; | |
752 | best = parent_rate; | |
753 | } | |
754 | } | |
755 | ||
756 | out: | |
757 | if (best_parent) | |
758 | *best_parent_p = best_parent; | |
759 | *best_parent_rate = best; | |
760 | ||
761 | return best; | |
762 | } | |
0b7f04b8 | 763 | EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); |
e366fdd7 | 764 | |
b2476490 MT |
765 | /*** clk api ***/ |
766 | ||
767 | void __clk_unprepare(struct clk *clk) | |
768 | { | |
769 | if (!clk) | |
770 | return; | |
771 | ||
772 | if (WARN_ON(clk->prepare_count == 0)) | |
773 | return; | |
774 | ||
775 | if (--clk->prepare_count > 0) | |
776 | return; | |
777 | ||
778 | WARN_ON(clk->enable_count > 0); | |
779 | ||
780 | if (clk->ops->unprepare) | |
781 | clk->ops->unprepare(clk->hw); | |
782 | ||
783 | __clk_unprepare(clk->parent); | |
784 | } | |
785 | ||
786 | /** | |
787 | * clk_unprepare - undo preparation of a clock source | |
24ee1a08 | 788 | * @clk: the clk being unprepared |
b2476490 MT |
789 | * |
790 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
791 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
792 | * if the operation may sleep. One example is a clk which is accessed over | |
793 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
794 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
795 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
796 | */ | |
797 | void clk_unprepare(struct clk *clk) | |
798 | { | |
63589e92 SB |
799 | if (IS_ERR_OR_NULL(clk)) |
800 | return; | |
801 | ||
eab89f69 | 802 | clk_prepare_lock(); |
b2476490 | 803 | __clk_unprepare(clk); |
eab89f69 | 804 | clk_prepare_unlock(); |
b2476490 MT |
805 | } |
806 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
807 | ||
808 | int __clk_prepare(struct clk *clk) | |
809 | { | |
810 | int ret = 0; | |
811 | ||
812 | if (!clk) | |
813 | return 0; | |
814 | ||
815 | if (clk->prepare_count == 0) { | |
816 | ret = __clk_prepare(clk->parent); | |
817 | if (ret) | |
818 | return ret; | |
819 | ||
820 | if (clk->ops->prepare) { | |
821 | ret = clk->ops->prepare(clk->hw); | |
822 | if (ret) { | |
823 | __clk_unprepare(clk->parent); | |
824 | return ret; | |
825 | } | |
826 | } | |
827 | } | |
828 | ||
829 | clk->prepare_count++; | |
830 | ||
831 | return 0; | |
832 | } | |
833 | ||
834 | /** | |
835 | * clk_prepare - prepare a clock source | |
836 | * @clk: the clk being prepared | |
837 | * | |
838 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
839 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
840 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
841 | * the complex case a clk ungate operation may require a fast and a slow part. | |
842 | * It is this reason that clk_prepare and clk_enable are not mutually | |
843 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
844 | * Returns 0 on success, -EERROR otherwise. | |
845 | */ | |
846 | int clk_prepare(struct clk *clk) | |
847 | { | |
848 | int ret; | |
849 | ||
eab89f69 | 850 | clk_prepare_lock(); |
b2476490 | 851 | ret = __clk_prepare(clk); |
eab89f69 | 852 | clk_prepare_unlock(); |
b2476490 MT |
853 | |
854 | return ret; | |
855 | } | |
856 | EXPORT_SYMBOL_GPL(clk_prepare); | |
857 | ||
858 | static void __clk_disable(struct clk *clk) | |
859 | { | |
860 | if (!clk) | |
861 | return; | |
862 | ||
863 | if (WARN_ON(clk->enable_count == 0)) | |
864 | return; | |
865 | ||
866 | if (--clk->enable_count > 0) | |
867 | return; | |
868 | ||
869 | if (clk->ops->disable) | |
870 | clk->ops->disable(clk->hw); | |
871 | ||
872 | __clk_disable(clk->parent); | |
873 | } | |
874 | ||
875 | /** | |
876 | * clk_disable - gate a clock | |
877 | * @clk: the clk being gated | |
878 | * | |
879 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
880 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
881 | * clk if the operation is fast and will never sleep. One example is a | |
882 | * SoC-internal clk which is controlled via simple register writes. In the | |
883 | * complex case a clk gate operation may require a fast and a slow part. It is | |
884 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
885 | * In fact clk_disable must be called before clk_unprepare. | |
886 | */ | |
887 | void clk_disable(struct clk *clk) | |
888 | { | |
889 | unsigned long flags; | |
890 | ||
63589e92 SB |
891 | if (IS_ERR_OR_NULL(clk)) |
892 | return; | |
893 | ||
eab89f69 | 894 | flags = clk_enable_lock(); |
b2476490 | 895 | __clk_disable(clk); |
eab89f69 | 896 | clk_enable_unlock(flags); |
b2476490 MT |
897 | } |
898 | EXPORT_SYMBOL_GPL(clk_disable); | |
899 | ||
900 | static int __clk_enable(struct clk *clk) | |
901 | { | |
902 | int ret = 0; | |
903 | ||
904 | if (!clk) | |
905 | return 0; | |
906 | ||
907 | if (WARN_ON(clk->prepare_count == 0)) | |
908 | return -ESHUTDOWN; | |
909 | ||
910 | if (clk->enable_count == 0) { | |
911 | ret = __clk_enable(clk->parent); | |
912 | ||
913 | if (ret) | |
914 | return ret; | |
915 | ||
916 | if (clk->ops->enable) { | |
917 | ret = clk->ops->enable(clk->hw); | |
918 | if (ret) { | |
919 | __clk_disable(clk->parent); | |
920 | return ret; | |
921 | } | |
922 | } | |
923 | } | |
924 | ||
925 | clk->enable_count++; | |
926 | return 0; | |
927 | } | |
928 | ||
929 | /** | |
930 | * clk_enable - ungate a clock | |
931 | * @clk: the clk being ungated | |
932 | * | |
933 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
934 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
935 | * if the operation will never sleep. One example is a SoC-internal clk which | |
936 | * is controlled via simple register writes. In the complex case a clk ungate | |
937 | * operation may require a fast and a slow part. It is this reason that | |
938 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
939 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
940 | * otherwise. | |
941 | */ | |
942 | int clk_enable(struct clk *clk) | |
943 | { | |
944 | unsigned long flags; | |
945 | int ret; | |
946 | ||
eab89f69 | 947 | flags = clk_enable_lock(); |
b2476490 | 948 | ret = __clk_enable(clk); |
eab89f69 | 949 | clk_enable_unlock(flags); |
b2476490 MT |
950 | |
951 | return ret; | |
952 | } | |
953 | EXPORT_SYMBOL_GPL(clk_enable); | |
954 | ||
b2476490 MT |
955 | /** |
956 | * __clk_round_rate - round the given rate for a clk | |
957 | * @clk: round the rate of this clock | |
24ee1a08 | 958 | * @rate: the rate which is to be rounded |
b2476490 MT |
959 | * |
960 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
961 | */ | |
962 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
963 | { | |
81536e07 | 964 | unsigned long parent_rate = 0; |
71472c0c | 965 | struct clk *parent; |
b2476490 MT |
966 | |
967 | if (!clk) | |
2ac6b1f5 | 968 | return 0; |
b2476490 | 969 | |
71472c0c JH |
970 | parent = clk->parent; |
971 | if (parent) | |
972 | parent_rate = parent->rate; | |
973 | ||
974 | if (clk->ops->determine_rate) | |
975 | return clk->ops->determine_rate(clk->hw, rate, &parent_rate, | |
976 | &parent); | |
977 | else if (clk->ops->round_rate) | |
978 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); | |
979 | else if (clk->flags & CLK_SET_RATE_PARENT) | |
980 | return __clk_round_rate(clk->parent, rate); | |
981 | else | |
982 | return clk->rate; | |
b2476490 | 983 | } |
1cdf8ee2 | 984 | EXPORT_SYMBOL_GPL(__clk_round_rate); |
b2476490 MT |
985 | |
986 | /** | |
987 | * clk_round_rate - round the given rate for a clk | |
988 | * @clk: the clk for which we are rounding a rate | |
989 | * @rate: the rate which is to be rounded | |
990 | * | |
991 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
992 | * use which is then returned. If clk doesn't support round_rate operation | |
993 | * then the parent rate is returned. | |
994 | */ | |
995 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
996 | { | |
997 | unsigned long ret; | |
998 | ||
eab89f69 | 999 | clk_prepare_lock(); |
b2476490 | 1000 | ret = __clk_round_rate(clk, rate); |
eab89f69 | 1001 | clk_prepare_unlock(); |
b2476490 MT |
1002 | |
1003 | return ret; | |
1004 | } | |
1005 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
1006 | ||
1007 | /** | |
1008 | * __clk_notify - call clk notifier chain | |
1009 | * @clk: struct clk * that is changing rate | |
1010 | * @msg: clk notifier type (see include/linux/clk.h) | |
1011 | * @old_rate: old clk rate | |
1012 | * @new_rate: new clk rate | |
1013 | * | |
1014 | * Triggers a notifier call chain on the clk rate-change notification | |
1015 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
1016 | * and current rates to the notifier callback. Intended to be called by | |
1017 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
1018 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
1019 | * a driver returns that. | |
1020 | */ | |
1021 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
1022 | unsigned long old_rate, unsigned long new_rate) | |
1023 | { | |
1024 | struct clk_notifier *cn; | |
1025 | struct clk_notifier_data cnd; | |
1026 | int ret = NOTIFY_DONE; | |
1027 | ||
1028 | cnd.clk = clk; | |
1029 | cnd.old_rate = old_rate; | |
1030 | cnd.new_rate = new_rate; | |
1031 | ||
1032 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
1033 | if (cn->clk == clk) { | |
1034 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
1035 | &cnd); | |
1036 | break; | |
1037 | } | |
1038 | } | |
1039 | ||
1040 | return ret; | |
1041 | } | |
1042 | ||
5279fc40 BB |
1043 | /** |
1044 | * __clk_recalc_accuracies | |
1045 | * @clk: first clk in the subtree | |
1046 | * | |
1047 | * Walks the subtree of clks starting with clk and recalculates accuracies as | |
1048 | * it goes. Note that if a clk does not implement the .recalc_accuracy | |
1049 | * callback then it is assumed that the clock will take on the accuracy of it's | |
1050 | * parent. | |
1051 | * | |
1052 | * Caller must hold prepare_lock. | |
1053 | */ | |
1054 | static void __clk_recalc_accuracies(struct clk *clk) | |
1055 | { | |
1056 | unsigned long parent_accuracy = 0; | |
1057 | struct clk *child; | |
1058 | ||
1059 | if (clk->parent) | |
1060 | parent_accuracy = clk->parent->accuracy; | |
1061 | ||
1062 | if (clk->ops->recalc_accuracy) | |
1063 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1064 | parent_accuracy); | |
1065 | else | |
1066 | clk->accuracy = parent_accuracy; | |
1067 | ||
1068 | hlist_for_each_entry(child, &clk->children, child_node) | |
1069 | __clk_recalc_accuracies(child); | |
1070 | } | |
1071 | ||
1072 | /** | |
1073 | * clk_get_accuracy - return the accuracy of clk | |
1074 | * @clk: the clk whose accuracy is being returned | |
1075 | * | |
1076 | * Simply returns the cached accuracy of the clk, unless | |
1077 | * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be | |
1078 | * issued. | |
1079 | * If clk is NULL then returns 0. | |
1080 | */ | |
1081 | long clk_get_accuracy(struct clk *clk) | |
1082 | { | |
1083 | unsigned long accuracy; | |
1084 | ||
1085 | clk_prepare_lock(); | |
1086 | if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE)) | |
1087 | __clk_recalc_accuracies(clk); | |
1088 | ||
1089 | accuracy = __clk_get_accuracy(clk); | |
1090 | clk_prepare_unlock(); | |
1091 | ||
1092 | return accuracy; | |
1093 | } | |
1094 | EXPORT_SYMBOL_GPL(clk_get_accuracy); | |
1095 | ||
8f2c2db1 SB |
1096 | static unsigned long clk_recalc(struct clk *clk, unsigned long parent_rate) |
1097 | { | |
1098 | if (clk->ops->recalc_rate) | |
1099 | return clk->ops->recalc_rate(clk->hw, parent_rate); | |
1100 | return parent_rate; | |
1101 | } | |
1102 | ||
b2476490 MT |
1103 | /** |
1104 | * __clk_recalc_rates | |
1105 | * @clk: first clk in the subtree | |
1106 | * @msg: notification type (see include/linux/clk.h) | |
1107 | * | |
1108 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
1109 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
24ee1a08 | 1110 | * it is assumed that the clock will take on the rate of its parent. |
b2476490 MT |
1111 | * |
1112 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
1113 | * if necessary. | |
1114 | * | |
1115 | * Caller must hold prepare_lock. | |
1116 | */ | |
1117 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
1118 | { | |
1119 | unsigned long old_rate; | |
1120 | unsigned long parent_rate = 0; | |
b2476490 MT |
1121 | struct clk *child; |
1122 | ||
1123 | old_rate = clk->rate; | |
1124 | ||
1125 | if (clk->parent) | |
1126 | parent_rate = clk->parent->rate; | |
1127 | ||
8f2c2db1 | 1128 | clk->rate = clk_recalc(clk, parent_rate); |
b2476490 MT |
1129 | |
1130 | /* | |
1131 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
1132 | * & ABORT_RATE_CHANGE notifiers | |
1133 | */ | |
1134 | if (clk->notifier_count && msg) | |
1135 | __clk_notify(clk, msg, old_rate, clk->rate); | |
1136 | ||
b67bfe0d | 1137 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
1138 | __clk_recalc_rates(child, msg); |
1139 | } | |
1140 | ||
a093bde2 UH |
1141 | /** |
1142 | * clk_get_rate - return the rate of clk | |
1143 | * @clk: the clk whose rate is being returned | |
1144 | * | |
1145 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
1146 | * is set, which means a recalc_rate will be issued. | |
1147 | * If clk is NULL then returns 0. | |
1148 | */ | |
1149 | unsigned long clk_get_rate(struct clk *clk) | |
1150 | { | |
1151 | unsigned long rate; | |
1152 | ||
eab89f69 | 1153 | clk_prepare_lock(); |
a093bde2 UH |
1154 | |
1155 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
1156 | __clk_recalc_rates(clk, 0); | |
1157 | ||
1158 | rate = __clk_get_rate(clk); | |
eab89f69 | 1159 | clk_prepare_unlock(); |
a093bde2 UH |
1160 | |
1161 | return rate; | |
1162 | } | |
1163 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
1164 | ||
f1c8b2ed | 1165 | static int clk_fetch_parent_index(struct clk *clk, struct clk *parent) |
4935b22c | 1166 | { |
f1c8b2ed | 1167 | int i; |
4935b22c | 1168 | |
f1c8b2ed | 1169 | if (!clk->parents) { |
96a7ed90 TF |
1170 | clk->parents = kcalloc(clk->num_parents, |
1171 | sizeof(struct clk *), GFP_KERNEL); | |
f1c8b2ed TF |
1172 | if (!clk->parents) |
1173 | return -ENOMEM; | |
1174 | } | |
4935b22c JH |
1175 | |
1176 | /* | |
1177 | * find index of new parent clock using cached parent ptrs, | |
1178 | * or if not yet cached, use string name comparison and cache | |
1179 | * them now to avoid future calls to __clk_lookup. | |
1180 | */ | |
1181 | for (i = 0; i < clk->num_parents; i++) { | |
da0f0b2c | 1182 | if (clk->parents[i] == parent) |
f1c8b2ed | 1183 | return i; |
da0f0b2c TF |
1184 | |
1185 | if (clk->parents[i]) | |
1186 | continue; | |
1187 | ||
1188 | if (!strcmp(clk->parent_names[i], parent->name)) { | |
1189 | clk->parents[i] = __clk_lookup(parent->name); | |
f1c8b2ed | 1190 | return i; |
4935b22c JH |
1191 | } |
1192 | } | |
1193 | ||
f1c8b2ed | 1194 | return -EINVAL; |
4935b22c JH |
1195 | } |
1196 | ||
1197 | static void clk_reparent(struct clk *clk, struct clk *new_parent) | |
1198 | { | |
1199 | hlist_del(&clk->child_node); | |
1200 | ||
903efc55 JH |
1201 | if (new_parent) { |
1202 | /* avoid duplicate POST_RATE_CHANGE notifications */ | |
1203 | if (new_parent->new_child == clk) | |
1204 | new_parent->new_child = NULL; | |
1205 | ||
4935b22c | 1206 | hlist_add_head(&clk->child_node, &new_parent->children); |
903efc55 | 1207 | } else { |
4935b22c | 1208 | hlist_add_head(&clk->child_node, &clk_orphan_list); |
903efc55 | 1209 | } |
4935b22c JH |
1210 | |
1211 | clk->parent = new_parent; | |
1212 | } | |
1213 | ||
3fa2252b | 1214 | static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent) |
4935b22c JH |
1215 | { |
1216 | unsigned long flags; | |
4935b22c JH |
1217 | struct clk *old_parent = clk->parent; |
1218 | ||
1219 | /* | |
1220 | * Migrate prepare state between parents and prevent race with | |
1221 | * clk_enable(). | |
1222 | * | |
1223 | * If the clock is not prepared, then a race with | |
1224 | * clk_enable/disable() is impossible since we already have the | |
1225 | * prepare lock (future calls to clk_enable() need to be preceded by | |
1226 | * a clk_prepare()). | |
1227 | * | |
1228 | * If the clock is prepared, migrate the prepared state to the new | |
1229 | * parent and also protect against a race with clk_enable() by | |
1230 | * forcing the clock and the new parent on. This ensures that all | |
1231 | * future calls to clk_enable() are practically NOPs with respect to | |
1232 | * hardware and software states. | |
1233 | * | |
1234 | * See also: Comment for clk_set_parent() below. | |
1235 | */ | |
1236 | if (clk->prepare_count) { | |
1237 | __clk_prepare(parent); | |
1238 | clk_enable(parent); | |
1239 | clk_enable(clk); | |
1240 | } | |
1241 | ||
1242 | /* update the clk tree topology */ | |
1243 | flags = clk_enable_lock(); | |
1244 | clk_reparent(clk, parent); | |
1245 | clk_enable_unlock(flags); | |
1246 | ||
3fa2252b SB |
1247 | return old_parent; |
1248 | } | |
1249 | ||
1250 | static void __clk_set_parent_after(struct clk *clk, struct clk *parent, | |
1251 | struct clk *old_parent) | |
1252 | { | |
1253 | /* | |
1254 | * Finish the migration of prepare state and undo the changes done | |
1255 | * for preventing a race with clk_enable(). | |
1256 | */ | |
1257 | if (clk->prepare_count) { | |
1258 | clk_disable(clk); | |
1259 | clk_disable(old_parent); | |
1260 | __clk_unprepare(old_parent); | |
1261 | } | |
3fa2252b SB |
1262 | } |
1263 | ||
1264 | static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) | |
1265 | { | |
1266 | unsigned long flags; | |
1267 | int ret = 0; | |
1268 | struct clk *old_parent; | |
1269 | ||
1270 | old_parent = __clk_set_parent_before(clk, parent); | |
1271 | ||
4935b22c JH |
1272 | /* change clock input source */ |
1273 | if (parent && clk->ops->set_parent) | |
1274 | ret = clk->ops->set_parent(clk->hw, p_index); | |
1275 | ||
1276 | if (ret) { | |
1277 | flags = clk_enable_lock(); | |
1278 | clk_reparent(clk, old_parent); | |
1279 | clk_enable_unlock(flags); | |
1280 | ||
1281 | if (clk->prepare_count) { | |
1282 | clk_disable(clk); | |
1283 | clk_disable(parent); | |
1284 | __clk_unprepare(parent); | |
1285 | } | |
1286 | return ret; | |
1287 | } | |
1288 | ||
3fa2252b | 1289 | __clk_set_parent_after(clk, parent, old_parent); |
4935b22c | 1290 | |
4935b22c JH |
1291 | return 0; |
1292 | } | |
1293 | ||
b2476490 MT |
1294 | /** |
1295 | * __clk_speculate_rates | |
1296 | * @clk: first clk in the subtree | |
1297 | * @parent_rate: the "future" rate of clk's parent | |
1298 | * | |
1299 | * Walks the subtree of clks starting with clk, speculating rates as it | |
1300 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
1301 | * | |
1302 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
1303 | * pre-rate change notifications and returns early if no clks in the | |
1304 | * subtree have subscribed to the notifications. Note that if a clk does not | |
1305 | * implement the .recalc_rate callback then it is assumed that the clock will | |
24ee1a08 | 1306 | * take on the rate of its parent. |
b2476490 MT |
1307 | * |
1308 | * Caller must hold prepare_lock. | |
1309 | */ | |
1310 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
1311 | { | |
b2476490 MT |
1312 | struct clk *child; |
1313 | unsigned long new_rate; | |
1314 | int ret = NOTIFY_DONE; | |
1315 | ||
8f2c2db1 | 1316 | new_rate = clk_recalc(clk, parent_rate); |
b2476490 | 1317 | |
fb72a059 | 1318 | /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ |
b2476490 MT |
1319 | if (clk->notifier_count) |
1320 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
1321 | ||
86bcfa2e MT |
1322 | if (ret & NOTIFY_STOP_MASK) { |
1323 | pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n", | |
1324 | __func__, clk->name, ret); | |
b2476490 | 1325 | goto out; |
86bcfa2e | 1326 | } |
b2476490 | 1327 | |
b67bfe0d | 1328 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 | 1329 | ret = __clk_speculate_rates(child, new_rate); |
fb72a059 | 1330 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1331 | break; |
1332 | } | |
1333 | ||
1334 | out: | |
1335 | return ret; | |
1336 | } | |
1337 | ||
71472c0c JH |
1338 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate, |
1339 | struct clk *new_parent, u8 p_index) | |
b2476490 MT |
1340 | { |
1341 | struct clk *child; | |
b2476490 MT |
1342 | |
1343 | clk->new_rate = new_rate; | |
71472c0c JH |
1344 | clk->new_parent = new_parent; |
1345 | clk->new_parent_index = p_index; | |
1346 | /* include clk in new parent's PRE_RATE_CHANGE notifications */ | |
1347 | clk->new_child = NULL; | |
1348 | if (new_parent && new_parent != clk->parent) | |
1349 | new_parent->new_child = clk; | |
b2476490 | 1350 | |
b67bfe0d | 1351 | hlist_for_each_entry(child, &clk->children, child_node) { |
8f2c2db1 | 1352 | child->new_rate = clk_recalc(child, new_rate); |
71472c0c | 1353 | clk_calc_subtree(child, child->new_rate, NULL, 0); |
b2476490 MT |
1354 | } |
1355 | } | |
1356 | ||
1357 | /* | |
1358 | * calculate the new rates returning the topmost clock that has to be | |
1359 | * changed. | |
1360 | */ | |
1361 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
1362 | { | |
1363 | struct clk *top = clk; | |
71472c0c | 1364 | struct clk *old_parent, *parent; |
81536e07 | 1365 | unsigned long best_parent_rate = 0; |
b2476490 | 1366 | unsigned long new_rate; |
f1c8b2ed | 1367 | int p_index = 0; |
b2476490 | 1368 | |
7452b219 MT |
1369 | /* sanity */ |
1370 | if (IS_ERR_OR_NULL(clk)) | |
1371 | return NULL; | |
1372 | ||
63f5c3b2 | 1373 | /* save parent rate, if it exists */ |
71472c0c JH |
1374 | parent = old_parent = clk->parent; |
1375 | if (parent) | |
1376 | best_parent_rate = parent->rate; | |
1377 | ||
1378 | /* find the closest rate and parent clk/rate */ | |
1379 | if (clk->ops->determine_rate) { | |
1380 | new_rate = clk->ops->determine_rate(clk->hw, rate, | |
1381 | &best_parent_rate, | |
1382 | &parent); | |
1383 | } else if (clk->ops->round_rate) { | |
1384 | new_rate = clk->ops->round_rate(clk->hw, rate, | |
1385 | &best_parent_rate); | |
1386 | } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) { | |
1387 | /* pass-through clock without adjustable parent */ | |
1388 | clk->new_rate = clk->rate; | |
1389 | return NULL; | |
1390 | } else { | |
1391 | /* pass-through clock with adjustable parent */ | |
1392 | top = clk_calc_new_rates(parent, rate); | |
1393 | new_rate = parent->new_rate; | |
63f5c3b2 | 1394 | goto out; |
7452b219 MT |
1395 | } |
1396 | ||
71472c0c JH |
1397 | /* some clocks must be gated to change parent */ |
1398 | if (parent != old_parent && | |
1399 | (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1400 | pr_debug("%s: %s not gated but wants to reparent\n", | |
1401 | __func__, clk->name); | |
b2476490 MT |
1402 | return NULL; |
1403 | } | |
1404 | ||
71472c0c JH |
1405 | /* try finding the new parent index */ |
1406 | if (parent) { | |
1407 | p_index = clk_fetch_parent_index(clk, parent); | |
f1c8b2ed | 1408 | if (p_index < 0) { |
71472c0c JH |
1409 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1410 | __func__, parent->name, clk->name); | |
1411 | return NULL; | |
1412 | } | |
b2476490 MT |
1413 | } |
1414 | ||
71472c0c JH |
1415 | if ((clk->flags & CLK_SET_RATE_PARENT) && parent && |
1416 | best_parent_rate != parent->rate) | |
1417 | top = clk_calc_new_rates(parent, best_parent_rate); | |
b2476490 MT |
1418 | |
1419 | out: | |
71472c0c | 1420 | clk_calc_subtree(clk, new_rate, parent, p_index); |
b2476490 MT |
1421 | |
1422 | return top; | |
1423 | } | |
1424 | ||
1425 | /* | |
1426 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
1427 | * so that in case of an error we can walk down the whole tree again and | |
1428 | * abort the change. | |
1429 | */ | |
1430 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
1431 | { | |
71472c0c | 1432 | struct clk *child, *tmp_clk, *fail_clk = NULL; |
b2476490 MT |
1433 | int ret = NOTIFY_DONE; |
1434 | ||
1435 | if (clk->rate == clk->new_rate) | |
5fda6858 | 1436 | return NULL; |
b2476490 MT |
1437 | |
1438 | if (clk->notifier_count) { | |
1439 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
fb72a059 | 1440 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1441 | fail_clk = clk; |
1442 | } | |
1443 | ||
b67bfe0d | 1444 | hlist_for_each_entry(child, &clk->children, child_node) { |
71472c0c JH |
1445 | /* Skip children who will be reparented to another clock */ |
1446 | if (child->new_parent && child->new_parent != clk) | |
1447 | continue; | |
1448 | tmp_clk = clk_propagate_rate_change(child, event); | |
1449 | if (tmp_clk) | |
1450 | fail_clk = tmp_clk; | |
1451 | } | |
1452 | ||
1453 | /* handle the new child who might not be in clk->children yet */ | |
1454 | if (clk->new_child) { | |
1455 | tmp_clk = clk_propagate_rate_change(clk->new_child, event); | |
1456 | if (tmp_clk) | |
1457 | fail_clk = tmp_clk; | |
b2476490 MT |
1458 | } |
1459 | ||
1460 | return fail_clk; | |
1461 | } | |
1462 | ||
1463 | /* | |
1464 | * walk down a subtree and set the new rates notifying the rate | |
1465 | * change on the way | |
1466 | */ | |
1467 | static void clk_change_rate(struct clk *clk) | |
1468 | { | |
1469 | struct clk *child; | |
067bb174 | 1470 | struct hlist_node *tmp; |
b2476490 | 1471 | unsigned long old_rate; |
bf47b4fd | 1472 | unsigned long best_parent_rate = 0; |
3fa2252b SB |
1473 | bool skip_set_rate = false; |
1474 | struct clk *old_parent; | |
b2476490 MT |
1475 | |
1476 | old_rate = clk->rate; | |
1477 | ||
3fa2252b SB |
1478 | if (clk->new_parent) |
1479 | best_parent_rate = clk->new_parent->rate; | |
1480 | else if (clk->parent) | |
bf47b4fd PM |
1481 | best_parent_rate = clk->parent->rate; |
1482 | ||
3fa2252b SB |
1483 | if (clk->new_parent && clk->new_parent != clk->parent) { |
1484 | old_parent = __clk_set_parent_before(clk, clk->new_parent); | |
1485 | ||
1486 | if (clk->ops->set_rate_and_parent) { | |
1487 | skip_set_rate = true; | |
1488 | clk->ops->set_rate_and_parent(clk->hw, clk->new_rate, | |
1489 | best_parent_rate, | |
1490 | clk->new_parent_index); | |
1491 | } else if (clk->ops->set_parent) { | |
1492 | clk->ops->set_parent(clk->hw, clk->new_parent_index); | |
1493 | } | |
1494 | ||
1495 | __clk_set_parent_after(clk, clk->new_parent, old_parent); | |
1496 | } | |
1497 | ||
1498 | if (!skip_set_rate && clk->ops->set_rate) | |
bf47b4fd | 1499 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 | 1500 | |
8f2c2db1 | 1501 | clk->rate = clk_recalc(clk, best_parent_rate); |
b2476490 MT |
1502 | |
1503 | if (clk->notifier_count && old_rate != clk->rate) | |
1504 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
1505 | ||
067bb174 TK |
1506 | /* |
1507 | * Use safe iteration, as change_rate can actually swap parents | |
1508 | * for certain clock types. | |
1509 | */ | |
1510 | hlist_for_each_entry_safe(child, tmp, &clk->children, child_node) { | |
71472c0c JH |
1511 | /* Skip children who will be reparented to another clock */ |
1512 | if (child->new_parent && child->new_parent != clk) | |
1513 | continue; | |
b2476490 | 1514 | clk_change_rate(child); |
71472c0c JH |
1515 | } |
1516 | ||
1517 | /* handle the new child who might not be in clk->children yet */ | |
1518 | if (clk->new_child) | |
1519 | clk_change_rate(clk->new_child); | |
b2476490 MT |
1520 | } |
1521 | ||
1522 | /** | |
1523 | * clk_set_rate - specify a new rate for clk | |
1524 | * @clk: the clk whose rate is being changed | |
1525 | * @rate: the new rate for clk | |
1526 | * | |
5654dc94 | 1527 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 1528 | * |
5654dc94 MT |
1529 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
1530 | * propagate up to clk's parent; whether or not this happens depends on the | |
1531 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
1532 | * after calling .round_rate then upstream parent propagation is ignored. If | |
1533 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
24ee1a08 | 1534 | * up to clk's parent and set its rate. Upward propagation will continue |
5654dc94 MT |
1535 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or |
1536 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 1537 | * |
5654dc94 MT |
1538 | * Rate changes are accomplished via tree traversal that also recalculates the |
1539 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
1540 | * |
1541 | * Returns 0 on success, -EERROR otherwise. | |
1542 | */ | |
1543 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
1544 | { | |
1545 | struct clk *top, *fail_clk; | |
1546 | int ret = 0; | |
1547 | ||
89ac8d7a MT |
1548 | if (!clk) |
1549 | return 0; | |
1550 | ||
b2476490 | 1551 | /* prevent racing with updates to the clock topology */ |
eab89f69 | 1552 | clk_prepare_lock(); |
b2476490 MT |
1553 | |
1554 | /* bail early if nothing to do */ | |
34e452a1 | 1555 | if (rate == clk_get_rate(clk)) |
b2476490 MT |
1556 | goto out; |
1557 | ||
7e0fa1b5 | 1558 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
1559 | ret = -EBUSY; |
1560 | goto out; | |
1561 | } | |
1562 | ||
b2476490 MT |
1563 | /* calculate new rates and get the topmost changed clock */ |
1564 | top = clk_calc_new_rates(clk, rate); | |
1565 | if (!top) { | |
1566 | ret = -EINVAL; | |
1567 | goto out; | |
1568 | } | |
1569 | ||
1570 | /* notify that we are about to change rates */ | |
1571 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
1572 | if (fail_clk) { | |
f7363861 | 1573 | pr_debug("%s: failed to set %s rate\n", __func__, |
b2476490 MT |
1574 | fail_clk->name); |
1575 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
1576 | ret = -EBUSY; | |
1577 | goto out; | |
1578 | } | |
1579 | ||
1580 | /* change the rates */ | |
1581 | clk_change_rate(top); | |
1582 | ||
b2476490 | 1583 | out: |
eab89f69 | 1584 | clk_prepare_unlock(); |
b2476490 MT |
1585 | |
1586 | return ret; | |
1587 | } | |
1588 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
1589 | ||
1590 | /** | |
1591 | * clk_get_parent - return the parent of a clk | |
1592 | * @clk: the clk whose parent gets returned | |
1593 | * | |
1594 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
1595 | */ | |
1596 | struct clk *clk_get_parent(struct clk *clk) | |
1597 | { | |
1598 | struct clk *parent; | |
1599 | ||
eab89f69 | 1600 | clk_prepare_lock(); |
b2476490 | 1601 | parent = __clk_get_parent(clk); |
eab89f69 | 1602 | clk_prepare_unlock(); |
b2476490 MT |
1603 | |
1604 | return parent; | |
1605 | } | |
1606 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
1607 | ||
1608 | /* | |
1609 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
1610 | * optional for single-parent clocks. Always call .get_parent if it is | |
1611 | * available and WARN if it is missing for multi-parent clocks. | |
1612 | * | |
1613 | * For single-parent clocks without .get_parent, first check to see if the | |
1614 | * .parents array exists, and if so use it to avoid an expensive tree | |
1615 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
1616 | */ | |
1617 | static struct clk *__clk_init_parent(struct clk *clk) | |
1618 | { | |
1619 | struct clk *ret = NULL; | |
1620 | u8 index; | |
1621 | ||
1622 | /* handle the trivial cases */ | |
1623 | ||
1624 | if (!clk->num_parents) | |
1625 | goto out; | |
1626 | ||
1627 | if (clk->num_parents == 1) { | |
1628 | if (IS_ERR_OR_NULL(clk->parent)) | |
1629 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); | |
1630 | ret = clk->parent; | |
1631 | goto out; | |
1632 | } | |
1633 | ||
1634 | if (!clk->ops->get_parent) { | |
1635 | WARN(!clk->ops->get_parent, | |
1636 | "%s: multi-parent clocks must implement .get_parent\n", | |
1637 | __func__); | |
1638 | goto out; | |
1639 | }; | |
1640 | ||
1641 | /* | |
1642 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1643 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1644 | * clk->parent here; that is done by the calling function | |
1645 | */ | |
1646 | ||
1647 | index = clk->ops->get_parent(clk->hw); | |
1648 | ||
1649 | if (!clk->parents) | |
1650 | clk->parents = | |
96a7ed90 | 1651 | kcalloc(clk->num_parents, sizeof(struct clk *), |
b2476490 MT |
1652 | GFP_KERNEL); |
1653 | ||
7ef3dcc8 | 1654 | ret = clk_get_parent_by_index(clk, index); |
b2476490 MT |
1655 | |
1656 | out: | |
1657 | return ret; | |
1658 | } | |
1659 | ||
b33d212f UH |
1660 | void __clk_reparent(struct clk *clk, struct clk *new_parent) |
1661 | { | |
1662 | clk_reparent(clk, new_parent); | |
5279fc40 | 1663 | __clk_recalc_accuracies(clk); |
b2476490 MT |
1664 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
1665 | } | |
1666 | ||
b2476490 MT |
1667 | /** |
1668 | * clk_set_parent - switch the parent of a mux clk | |
1669 | * @clk: the mux clk whose input we are switching | |
1670 | * @parent: the new input to clk | |
1671 | * | |
f8aa0bd5 SK |
1672 | * Re-parent clk to use parent as its new input source. If clk is in |
1673 | * prepared state, the clk will get enabled for the duration of this call. If | |
1674 | * that's not acceptable for a specific clk (Eg: the consumer can't handle | |
1675 | * that, the reparenting is glitchy in hardware, etc), use the | |
1676 | * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. | |
1677 | * | |
1678 | * After successfully changing clk's parent clk_set_parent will update the | |
1679 | * clk topology, sysfs topology and propagate rate recalculation via | |
1680 | * __clk_recalc_rates. | |
1681 | * | |
1682 | * Returns 0 on success, -EERROR otherwise. | |
b2476490 MT |
1683 | */ |
1684 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
1685 | { | |
1686 | int ret = 0; | |
f1c8b2ed | 1687 | int p_index = 0; |
031dcc9b | 1688 | unsigned long p_rate = 0; |
b2476490 | 1689 | |
89ac8d7a MT |
1690 | if (!clk) |
1691 | return 0; | |
1692 | ||
031dcc9b UH |
1693 | /* verify ops for for multi-parent clks */ |
1694 | if ((clk->num_parents > 1) && (!clk->ops->set_parent)) | |
b2476490 MT |
1695 | return -ENOSYS; |
1696 | ||
1697 | /* prevent racing with updates to the clock topology */ | |
eab89f69 | 1698 | clk_prepare_lock(); |
b2476490 MT |
1699 | |
1700 | if (clk->parent == parent) | |
1701 | goto out; | |
1702 | ||
031dcc9b UH |
1703 | /* check that we are allowed to re-parent if the clock is in use */ |
1704 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1705 | ret = -EBUSY; | |
1706 | goto out; | |
1707 | } | |
1708 | ||
1709 | /* try finding the new parent index */ | |
1710 | if (parent) { | |
1711 | p_index = clk_fetch_parent_index(clk, parent); | |
1712 | p_rate = parent->rate; | |
f1c8b2ed | 1713 | if (p_index < 0) { |
031dcc9b UH |
1714 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1715 | __func__, parent->name, clk->name); | |
f1c8b2ed | 1716 | ret = p_index; |
031dcc9b UH |
1717 | goto out; |
1718 | } | |
1719 | } | |
1720 | ||
b2476490 | 1721 | /* propagate PRE_RATE_CHANGE notifications */ |
f3aab5d6 | 1722 | ret = __clk_speculate_rates(clk, p_rate); |
b2476490 MT |
1723 | |
1724 | /* abort if a driver objects */ | |
fb72a059 | 1725 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1726 | goto out; |
1727 | ||
031dcc9b UH |
1728 | /* do the re-parent */ |
1729 | ret = __clk_set_parent(clk, parent, p_index); | |
b2476490 | 1730 | |
5279fc40 BB |
1731 | /* propagate rate an accuracy recalculation accordingly */ |
1732 | if (ret) { | |
b2476490 | 1733 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); |
5279fc40 | 1734 | } else { |
a68de8e4 | 1735 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
5279fc40 BB |
1736 | __clk_recalc_accuracies(clk); |
1737 | } | |
b2476490 MT |
1738 | |
1739 | out: | |
eab89f69 | 1740 | clk_prepare_unlock(); |
b2476490 MT |
1741 | |
1742 | return ret; | |
1743 | } | |
1744 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1745 | ||
1746 | /** | |
1747 | * __clk_init - initialize the data structures in a struct clk | |
1748 | * @dev: device initializing this clk, placeholder for now | |
1749 | * @clk: clk being initialized | |
1750 | * | |
1751 | * Initializes the lists in struct clk, queries the hardware for the | |
1752 | * parent and rate and sets them both. | |
b2476490 | 1753 | */ |
d1302a36 | 1754 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1755 | { |
d1302a36 | 1756 | int i, ret = 0; |
b2476490 | 1757 | struct clk *orphan; |
b67bfe0d | 1758 | struct hlist_node *tmp2; |
b2476490 MT |
1759 | |
1760 | if (!clk) | |
d1302a36 | 1761 | return -EINVAL; |
b2476490 | 1762 | |
eab89f69 | 1763 | clk_prepare_lock(); |
b2476490 MT |
1764 | |
1765 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1766 | if (__clk_lookup(clk->name)) { |
1767 | pr_debug("%s: clk %s already initialized\n", | |
1768 | __func__, clk->name); | |
1769 | ret = -EEXIST; | |
b2476490 | 1770 | goto out; |
d1302a36 | 1771 | } |
b2476490 | 1772 | |
d4d7e3dd MT |
1773 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1774 | if (clk->ops->set_rate && | |
71472c0c JH |
1775 | !((clk->ops->round_rate || clk->ops->determine_rate) && |
1776 | clk->ops->recalc_rate)) { | |
1777 | pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", | |
d4d7e3dd | 1778 | __func__, clk->name); |
d1302a36 | 1779 | ret = -EINVAL; |
d4d7e3dd MT |
1780 | goto out; |
1781 | } | |
1782 | ||
1783 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1784 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1785 | __func__, clk->name); | |
d1302a36 | 1786 | ret = -EINVAL; |
d4d7e3dd MT |
1787 | goto out; |
1788 | } | |
1789 | ||
3fa2252b SB |
1790 | if (clk->ops->set_rate_and_parent && |
1791 | !(clk->ops->set_parent && clk->ops->set_rate)) { | |
1792 | pr_warn("%s: %s must implement .set_parent & .set_rate\n", | |
1793 | __func__, clk->name); | |
1794 | ret = -EINVAL; | |
1795 | goto out; | |
1796 | } | |
1797 | ||
b2476490 MT |
1798 | /* throw a WARN if any entries in parent_names are NULL */ |
1799 | for (i = 0; i < clk->num_parents; i++) | |
1800 | WARN(!clk->parent_names[i], | |
1801 | "%s: invalid NULL in %s's .parent_names\n", | |
1802 | __func__, clk->name); | |
1803 | ||
1804 | /* | |
1805 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1806 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1807 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1808 | * must always check for a NULL pointer and try to populate it if | |
1809 | * necessary. | |
1810 | * | |
1811 | * If clk->parents is not NULL we skip this entire block. This allows | |
1812 | * for clock drivers to statically initialize clk->parents. | |
1813 | */ | |
9ca1c5a4 | 1814 | if (clk->num_parents > 1 && !clk->parents) { |
96a7ed90 TF |
1815 | clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *), |
1816 | GFP_KERNEL); | |
b2476490 MT |
1817 | /* |
1818 | * __clk_lookup returns NULL for parents that have not been | |
1819 | * clk_init'd; thus any access to clk->parents[] must check | |
1820 | * for a NULL pointer. We can always perform lazy lookups for | |
1821 | * missing parents later on. | |
1822 | */ | |
1823 | if (clk->parents) | |
1824 | for (i = 0; i < clk->num_parents; i++) | |
1825 | clk->parents[i] = | |
1826 | __clk_lookup(clk->parent_names[i]); | |
1827 | } | |
1828 | ||
1829 | clk->parent = __clk_init_parent(clk); | |
1830 | ||
1831 | /* | |
1832 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1833 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1834 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1835 | * clk list. | |
1836 | * | |
1837 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1838 | * clocks and re-parent any that are children of the clock currently | |
1839 | * being clk_init'd. | |
1840 | */ | |
1841 | if (clk->parent) | |
1842 | hlist_add_head(&clk->child_node, | |
1843 | &clk->parent->children); | |
1844 | else if (clk->flags & CLK_IS_ROOT) | |
1845 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1846 | else | |
1847 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1848 | ||
5279fc40 BB |
1849 | /* |
1850 | * Set clk's accuracy. The preferred method is to use | |
1851 | * .recalc_accuracy. For simple clocks and lazy developers the default | |
1852 | * fallback is to use the parent's accuracy. If a clock doesn't have a | |
1853 | * parent (or is orphaned) then accuracy is set to zero (perfect | |
1854 | * clock). | |
1855 | */ | |
1856 | if (clk->ops->recalc_accuracy) | |
1857 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1858 | __clk_get_accuracy(clk->parent)); | |
1859 | else if (clk->parent) | |
1860 | clk->accuracy = clk->parent->accuracy; | |
1861 | else | |
1862 | clk->accuracy = 0; | |
1863 | ||
b2476490 MT |
1864 | /* |
1865 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1866 | * simple clocks and lazy developers the default fallback is to use the | |
1867 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1868 | * then rate is set to zero. | |
1869 | */ | |
1870 | if (clk->ops->recalc_rate) | |
1871 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1872 | __clk_get_rate(clk->parent)); | |
1873 | else if (clk->parent) | |
1874 | clk->rate = clk->parent->rate; | |
1875 | else | |
1876 | clk->rate = 0; | |
1877 | ||
3a5aec24 | 1878 | clk_debug_register(clk); |
b2476490 MT |
1879 | /* |
1880 | * walk the list of orphan clocks and reparent any that are children of | |
1881 | * this clock | |
1882 | */ | |
b67bfe0d | 1883 | hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { |
12d29886 | 1884 | if (orphan->num_parents && orphan->ops->get_parent) { |
1f61e5f1 MF |
1885 | i = orphan->ops->get_parent(orphan->hw); |
1886 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1887 | __clk_reparent(orphan, clk); | |
1888 | continue; | |
1889 | } | |
1890 | ||
b2476490 MT |
1891 | for (i = 0; i < orphan->num_parents; i++) |
1892 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1893 | __clk_reparent(orphan, clk); | |
1894 | break; | |
1895 | } | |
1f61e5f1 | 1896 | } |
b2476490 MT |
1897 | |
1898 | /* | |
1899 | * optional platform-specific magic | |
1900 | * | |
1901 | * The .init callback is not used by any of the basic clock types, but | |
1902 | * exists for weird hardware that must perform initialization magic. | |
1903 | * Please consider other ways of solving initialization problems before | |
24ee1a08 | 1904 | * using this callback, as its use is discouraged. |
b2476490 MT |
1905 | */ |
1906 | if (clk->ops->init) | |
1907 | clk->ops->init(clk->hw); | |
1908 | ||
fcb0ee6a | 1909 | kref_init(&clk->ref); |
b2476490 | 1910 | out: |
eab89f69 | 1911 | clk_prepare_unlock(); |
b2476490 | 1912 | |
d1302a36 | 1913 | return ret; |
b2476490 MT |
1914 | } |
1915 | ||
0197b3ea SK |
1916 | /** |
1917 | * __clk_register - register a clock and return a cookie. | |
1918 | * | |
1919 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1920 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1921 | * of the struct clk need to be initialized. | |
1922 | * | |
1923 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1924 | * data. | |
1925 | * | |
1926 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1927 | * very large numbers of clocks that need to be statically initialized. It is | |
1928 | * a layering violation to include clk-private.h from any code which implements | |
1929 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
24ee1a08 | 1930 | * separate C file from the logic that implements its operations. Returns 0 |
0197b3ea SK |
1931 | * on success, otherwise an error code. |
1932 | */ | |
1933 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
1934 | { | |
1935 | int ret; | |
1936 | struct clk *clk; | |
1937 | ||
1938 | clk = hw->clk; | |
1939 | clk->name = hw->init->name; | |
1940 | clk->ops = hw->init->ops; | |
1941 | clk->hw = hw; | |
1942 | clk->flags = hw->init->flags; | |
1943 | clk->parent_names = hw->init->parent_names; | |
1944 | clk->num_parents = hw->init->num_parents; | |
ac2df527 SN |
1945 | if (dev && dev->driver) |
1946 | clk->owner = dev->driver->owner; | |
1947 | else | |
1948 | clk->owner = NULL; | |
0197b3ea SK |
1949 | |
1950 | ret = __clk_init(dev, clk); | |
1951 | if (ret) | |
1952 | return ERR_PTR(ret); | |
1953 | ||
1954 | return clk; | |
1955 | } | |
1956 | EXPORT_SYMBOL_GPL(__clk_register); | |
1957 | ||
293ba3b4 SB |
1958 | /** |
1959 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
1960 | * @dev: device that is registering this clock | |
1961 | * @hw: link to hardware-specific clock data | |
1962 | * | |
1963 | * clk_register is the primary interface for populating the clock tree with new | |
1964 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
1965 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
1966 | * rest of the clock API. In the event of an error clk_register will return an | |
1967 | * error code; drivers must test for an error code after calling clk_register. | |
1968 | */ | |
1969 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
b2476490 | 1970 | { |
d1302a36 | 1971 | int i, ret; |
293ba3b4 SB |
1972 | struct clk *clk; |
1973 | ||
1974 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
1975 | if (!clk) { | |
1976 | pr_err("%s: could not allocate clk\n", __func__); | |
1977 | ret = -ENOMEM; | |
1978 | goto fail_out; | |
1979 | } | |
b2476490 | 1980 | |
0197b3ea SK |
1981 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
1982 | if (!clk->name) { | |
1983 | pr_err("%s: could not allocate clk->name\n", __func__); | |
1984 | ret = -ENOMEM; | |
1985 | goto fail_name; | |
1986 | } | |
1987 | clk->ops = hw->init->ops; | |
ac2df527 SN |
1988 | if (dev && dev->driver) |
1989 | clk->owner = dev->driver->owner; | |
b2476490 | 1990 | clk->hw = hw; |
0197b3ea SK |
1991 | clk->flags = hw->init->flags; |
1992 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
1993 | hw->clk = clk; |
1994 | ||
d1302a36 | 1995 | /* allocate local copy in case parent_names is __initdata */ |
96a7ed90 TF |
1996 | clk->parent_names = kcalloc(clk->num_parents, sizeof(char *), |
1997 | GFP_KERNEL); | |
d1302a36 MT |
1998 | |
1999 | if (!clk->parent_names) { | |
2000 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
2001 | ret = -ENOMEM; | |
2002 | goto fail_parent_names; | |
2003 | } | |
2004 | ||
2005 | ||
2006 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea SK |
2007 | for (i = 0; i < clk->num_parents; i++) { |
2008 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], | |
2009 | GFP_KERNEL); | |
d1302a36 MT |
2010 | if (!clk->parent_names[i]) { |
2011 | pr_err("%s: could not copy parent_names\n", __func__); | |
2012 | ret = -ENOMEM; | |
2013 | goto fail_parent_names_copy; | |
2014 | } | |
2015 | } | |
2016 | ||
2017 | ret = __clk_init(dev, clk); | |
2018 | if (!ret) | |
293ba3b4 | 2019 | return clk; |
b2476490 | 2020 | |
d1302a36 MT |
2021 | fail_parent_names_copy: |
2022 | while (--i >= 0) | |
2023 | kfree(clk->parent_names[i]); | |
2024 | kfree(clk->parent_names); | |
2025 | fail_parent_names: | |
0197b3ea SK |
2026 | kfree(clk->name); |
2027 | fail_name: | |
d1302a36 MT |
2028 | kfree(clk); |
2029 | fail_out: | |
2030 | return ERR_PTR(ret); | |
b2476490 MT |
2031 | } |
2032 | EXPORT_SYMBOL_GPL(clk_register); | |
2033 | ||
fcb0ee6a SN |
2034 | /* |
2035 | * Free memory allocated for a clock. | |
2036 | * Caller must hold prepare_lock. | |
2037 | */ | |
2038 | static void __clk_release(struct kref *ref) | |
2039 | { | |
2040 | struct clk *clk = container_of(ref, struct clk, ref); | |
2041 | int i = clk->num_parents; | |
2042 | ||
2043 | kfree(clk->parents); | |
2044 | while (--i >= 0) | |
2045 | kfree(clk->parent_names[i]); | |
2046 | ||
2047 | kfree(clk->parent_names); | |
2048 | kfree(clk->name); | |
2049 | kfree(clk); | |
2050 | } | |
2051 | ||
2052 | /* | |
2053 | * Empty clk_ops for unregistered clocks. These are used temporarily | |
2054 | * after clk_unregister() was called on a clock and until last clock | |
2055 | * consumer calls clk_put() and the struct clk object is freed. | |
2056 | */ | |
2057 | static int clk_nodrv_prepare_enable(struct clk_hw *hw) | |
2058 | { | |
2059 | return -ENXIO; | |
2060 | } | |
2061 | ||
2062 | static void clk_nodrv_disable_unprepare(struct clk_hw *hw) | |
2063 | { | |
2064 | WARN_ON_ONCE(1); | |
2065 | } | |
2066 | ||
2067 | static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, | |
2068 | unsigned long parent_rate) | |
2069 | { | |
2070 | return -ENXIO; | |
2071 | } | |
2072 | ||
2073 | static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) | |
2074 | { | |
2075 | return -ENXIO; | |
2076 | } | |
2077 | ||
2078 | static const struct clk_ops clk_nodrv_ops = { | |
2079 | .enable = clk_nodrv_prepare_enable, | |
2080 | .disable = clk_nodrv_disable_unprepare, | |
2081 | .prepare = clk_nodrv_prepare_enable, | |
2082 | .unprepare = clk_nodrv_disable_unprepare, | |
2083 | .set_rate = clk_nodrv_set_rate, | |
2084 | .set_parent = clk_nodrv_set_parent, | |
2085 | }; | |
2086 | ||
1df5c939 MB |
2087 | /** |
2088 | * clk_unregister - unregister a currently registered clock | |
2089 | * @clk: clock to unregister | |
1df5c939 | 2090 | */ |
fcb0ee6a SN |
2091 | void clk_unregister(struct clk *clk) |
2092 | { | |
2093 | unsigned long flags; | |
2094 | ||
2095 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) | |
2096 | return; | |
2097 | ||
2098 | clk_prepare_lock(); | |
2099 | ||
2100 | if (clk->ops == &clk_nodrv_ops) { | |
2101 | pr_err("%s: unregistered clock: %s\n", __func__, clk->name); | |
2102 | goto out; | |
2103 | } | |
2104 | /* | |
2105 | * Assign empty clock ops for consumers that might still hold | |
2106 | * a reference to this clock. | |
2107 | */ | |
2108 | flags = clk_enable_lock(); | |
2109 | clk->ops = &clk_nodrv_ops; | |
2110 | clk_enable_unlock(flags); | |
2111 | ||
2112 | if (!hlist_empty(&clk->children)) { | |
2113 | struct clk *child; | |
874f224c | 2114 | struct hlist_node *t; |
fcb0ee6a SN |
2115 | |
2116 | /* Reparent all children to the orphan list. */ | |
874f224c | 2117 | hlist_for_each_entry_safe(child, t, &clk->children, child_node) |
fcb0ee6a SN |
2118 | clk_set_parent(child, NULL); |
2119 | } | |
2120 | ||
2121 | clk_debug_unregister(clk); | |
2122 | ||
2123 | hlist_del_init(&clk->child_node); | |
2124 | ||
2125 | if (clk->prepare_count) | |
2126 | pr_warn("%s: unregistering prepared clock: %s\n", | |
2127 | __func__, clk->name); | |
2128 | ||
2129 | kref_put(&clk->ref, __clk_release); | |
2130 | out: | |
2131 | clk_prepare_unlock(); | |
2132 | } | |
1df5c939 MB |
2133 | EXPORT_SYMBOL_GPL(clk_unregister); |
2134 | ||
46c8773a SB |
2135 | static void devm_clk_release(struct device *dev, void *res) |
2136 | { | |
293ba3b4 | 2137 | clk_unregister(*(struct clk **)res); |
46c8773a SB |
2138 | } |
2139 | ||
2140 | /** | |
2141 | * devm_clk_register - resource managed clk_register() | |
2142 | * @dev: device that is registering this clock | |
2143 | * @hw: link to hardware-specific clock data | |
2144 | * | |
2145 | * Managed clk_register(). Clocks returned from this function are | |
2146 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
2147 | * more information. | |
2148 | */ | |
2149 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
2150 | { | |
2151 | struct clk *clk; | |
293ba3b4 | 2152 | struct clk **clkp; |
46c8773a | 2153 | |
293ba3b4 SB |
2154 | clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL); |
2155 | if (!clkp) | |
46c8773a SB |
2156 | return ERR_PTR(-ENOMEM); |
2157 | ||
293ba3b4 SB |
2158 | clk = clk_register(dev, hw); |
2159 | if (!IS_ERR(clk)) { | |
2160 | *clkp = clk; | |
2161 | devres_add(dev, clkp); | |
46c8773a | 2162 | } else { |
293ba3b4 | 2163 | devres_free(clkp); |
46c8773a SB |
2164 | } |
2165 | ||
2166 | return clk; | |
2167 | } | |
2168 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
2169 | ||
2170 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
2171 | { | |
2172 | struct clk *c = res; | |
2173 | if (WARN_ON(!c)) | |
2174 | return 0; | |
2175 | return c == data; | |
2176 | } | |
2177 | ||
2178 | /** | |
2179 | * devm_clk_unregister - resource managed clk_unregister() | |
2180 | * @clk: clock to unregister | |
2181 | * | |
2182 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
2183 | * this function will not need to be called and the resource management | |
2184 | * code will ensure that the resource is freed. | |
2185 | */ | |
2186 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
2187 | { | |
2188 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
2189 | } | |
2190 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
2191 | ||
ac2df527 SN |
2192 | /* |
2193 | * clkdev helpers | |
2194 | */ | |
2195 | int __clk_get(struct clk *clk) | |
2196 | { | |
00efcb1c SN |
2197 | if (clk) { |
2198 | if (!try_module_get(clk->owner)) | |
2199 | return 0; | |
ac2df527 | 2200 | |
00efcb1c SN |
2201 | kref_get(&clk->ref); |
2202 | } | |
ac2df527 SN |
2203 | return 1; |
2204 | } | |
2205 | ||
2206 | void __clk_put(struct clk *clk) | |
2207 | { | |
00efcb1c | 2208 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) |
ac2df527 SN |
2209 | return; |
2210 | ||
fcb0ee6a SN |
2211 | clk_prepare_lock(); |
2212 | kref_put(&clk->ref, __clk_release); | |
2213 | clk_prepare_unlock(); | |
2214 | ||
00efcb1c | 2215 | module_put(clk->owner); |
ac2df527 SN |
2216 | } |
2217 | ||
b2476490 MT |
2218 | /*** clk rate change notifiers ***/ |
2219 | ||
2220 | /** | |
2221 | * clk_notifier_register - add a clk rate change notifier | |
2222 | * @clk: struct clk * to watch | |
2223 | * @nb: struct notifier_block * with callback info | |
2224 | * | |
2225 | * Request notification when clk's rate changes. This uses an SRCU | |
2226 | * notifier because we want it to block and notifier unregistrations are | |
2227 | * uncommon. The callbacks associated with the notifier must not | |
2228 | * re-enter into the clk framework by calling any top-level clk APIs; | |
2229 | * this will cause a nested prepare_lock mutex. | |
2230 | * | |
5324fda7 SB |
2231 | * In all notification cases cases (pre, post and abort rate change) the |
2232 | * original clock rate is passed to the callback via struct | |
2233 | * clk_notifier_data.old_rate and the new frequency is passed via struct | |
b2476490 MT |
2234 | * clk_notifier_data.new_rate. |
2235 | * | |
b2476490 MT |
2236 | * clk_notifier_register() must be called from non-atomic context. |
2237 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
2238 | * allocation failure; otherwise, passes along the return value of | |
2239 | * srcu_notifier_chain_register(). | |
2240 | */ | |
2241 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
2242 | { | |
2243 | struct clk_notifier *cn; | |
2244 | int ret = -ENOMEM; | |
2245 | ||
2246 | if (!clk || !nb) | |
2247 | return -EINVAL; | |
2248 | ||
eab89f69 | 2249 | clk_prepare_lock(); |
b2476490 MT |
2250 | |
2251 | /* search the list of notifiers for this clk */ | |
2252 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2253 | if (cn->clk == clk) | |
2254 | break; | |
2255 | ||
2256 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
2257 | if (cn->clk != clk) { | |
2258 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
2259 | if (!cn) | |
2260 | goto out; | |
2261 | ||
2262 | cn->clk = clk; | |
2263 | srcu_init_notifier_head(&cn->notifier_head); | |
2264 | ||
2265 | list_add(&cn->node, &clk_notifier_list); | |
2266 | } | |
2267 | ||
2268 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
2269 | ||
2270 | clk->notifier_count++; | |
2271 | ||
2272 | out: | |
eab89f69 | 2273 | clk_prepare_unlock(); |
b2476490 MT |
2274 | |
2275 | return ret; | |
2276 | } | |
2277 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
2278 | ||
2279 | /** | |
2280 | * clk_notifier_unregister - remove a clk rate change notifier | |
2281 | * @clk: struct clk * | |
2282 | * @nb: struct notifier_block * with callback info | |
2283 | * | |
2284 | * Request no further notification for changes to 'clk' and frees memory | |
2285 | * allocated in clk_notifier_register. | |
2286 | * | |
2287 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
2288 | * along the return value of srcu_notifier_chain_unregister(). | |
2289 | */ | |
2290 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
2291 | { | |
2292 | struct clk_notifier *cn = NULL; | |
2293 | int ret = -EINVAL; | |
2294 | ||
2295 | if (!clk || !nb) | |
2296 | return -EINVAL; | |
2297 | ||
eab89f69 | 2298 | clk_prepare_lock(); |
b2476490 MT |
2299 | |
2300 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2301 | if (cn->clk == clk) | |
2302 | break; | |
2303 | ||
2304 | if (cn->clk == clk) { | |
2305 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
2306 | ||
2307 | clk->notifier_count--; | |
2308 | ||
2309 | /* XXX the notifier code should handle this better */ | |
2310 | if (!cn->notifier_head.head) { | |
2311 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
72b5322f | 2312 | list_del(&cn->node); |
b2476490 MT |
2313 | kfree(cn); |
2314 | } | |
2315 | ||
2316 | } else { | |
2317 | ret = -ENOENT; | |
2318 | } | |
2319 | ||
eab89f69 | 2320 | clk_prepare_unlock(); |
b2476490 MT |
2321 | |
2322 | return ret; | |
2323 | } | |
2324 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
2325 | |
2326 | #ifdef CONFIG_OF | |
2327 | /** | |
2328 | * struct of_clk_provider - Clock provider registration structure | |
2329 | * @link: Entry in global list of clock providers | |
2330 | * @node: Pointer to device tree node of clock provider | |
2331 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
2332 | * given clock specifier | |
2333 | * @data: context pointer to be passed into @get callback | |
2334 | */ | |
2335 | struct of_clk_provider { | |
2336 | struct list_head link; | |
2337 | ||
2338 | struct device_node *node; | |
2339 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
2340 | void *data; | |
2341 | }; | |
2342 | ||
f2f6c255 PG |
2343 | static const struct of_device_id __clk_of_table_sentinel |
2344 | __used __section(__clk_of_table_end); | |
2345 | ||
766e6a4e | 2346 | static LIST_HEAD(of_clk_providers); |
d6782c26 SN |
2347 | static DEFINE_MUTEX(of_clk_mutex); |
2348 | ||
2349 | /* of_clk_provider list locking helpers */ | |
2350 | void of_clk_lock(void) | |
2351 | { | |
2352 | mutex_lock(&of_clk_mutex); | |
2353 | } | |
2354 | ||
2355 | void of_clk_unlock(void) | |
2356 | { | |
2357 | mutex_unlock(&of_clk_mutex); | |
2358 | } | |
766e6a4e GL |
2359 | |
2360 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
2361 | void *data) | |
2362 | { | |
2363 | return data; | |
2364 | } | |
2365 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
2366 | ||
494bfec9 SG |
2367 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
2368 | { | |
2369 | struct clk_onecell_data *clk_data = data; | |
2370 | unsigned int idx = clkspec->args[0]; | |
2371 | ||
2372 | if (idx >= clk_data->clk_num) { | |
2373 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
2374 | return ERR_PTR(-EINVAL); | |
2375 | } | |
2376 | ||
2377 | return clk_data->clks[idx]; | |
2378 | } | |
2379 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
2380 | ||
766e6a4e GL |
2381 | /** |
2382 | * of_clk_add_provider() - Register a clock provider for a node | |
2383 | * @np: Device node pointer associated with clock provider | |
2384 | * @clk_src_get: callback for decoding clock | |
2385 | * @data: context pointer for @clk_src_get callback. | |
2386 | */ | |
2387 | int of_clk_add_provider(struct device_node *np, | |
2388 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
2389 | void *data), | |
2390 | void *data) | |
2391 | { | |
2392 | struct of_clk_provider *cp; | |
86be408b | 2393 | int ret; |
766e6a4e GL |
2394 | |
2395 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
2396 | if (!cp) | |
2397 | return -ENOMEM; | |
2398 | ||
2399 | cp->node = of_node_get(np); | |
2400 | cp->data = data; | |
2401 | cp->get = clk_src_get; | |
2402 | ||
d6782c26 | 2403 | mutex_lock(&of_clk_mutex); |
766e6a4e | 2404 | list_add(&cp->link, &of_clk_providers); |
d6782c26 | 2405 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2406 | pr_debug("Added clock from %s\n", np->full_name); |
2407 | ||
86be408b SN |
2408 | ret = of_clk_set_defaults(np, true); |
2409 | if (ret < 0) | |
2410 | of_clk_del_provider(np); | |
2411 | ||
2412 | return ret; | |
766e6a4e GL |
2413 | } |
2414 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
2415 | ||
2416 | /** | |
2417 | * of_clk_del_provider() - Remove a previously registered clock provider | |
2418 | * @np: Device node pointer associated with clock provider | |
2419 | */ | |
2420 | void of_clk_del_provider(struct device_node *np) | |
2421 | { | |
2422 | struct of_clk_provider *cp; | |
2423 | ||
d6782c26 | 2424 | mutex_lock(&of_clk_mutex); |
766e6a4e GL |
2425 | list_for_each_entry(cp, &of_clk_providers, link) { |
2426 | if (cp->node == np) { | |
2427 | list_del(&cp->link); | |
2428 | of_node_put(cp->node); | |
2429 | kfree(cp); | |
2430 | break; | |
2431 | } | |
2432 | } | |
d6782c26 | 2433 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2434 | } |
2435 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
2436 | ||
d6782c26 | 2437 | struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) |
766e6a4e GL |
2438 | { |
2439 | struct of_clk_provider *provider; | |
a34cd466 | 2440 | struct clk *clk = ERR_PTR(-EPROBE_DEFER); |
766e6a4e GL |
2441 | |
2442 | /* Check if we have such a provider in our array */ | |
766e6a4e GL |
2443 | list_for_each_entry(provider, &of_clk_providers, link) { |
2444 | if (provider->node == clkspec->np) | |
2445 | clk = provider->get(clkspec, provider->data); | |
2446 | if (!IS_ERR(clk)) | |
2447 | break; | |
2448 | } | |
d6782c26 SN |
2449 | |
2450 | return clk; | |
2451 | } | |
2452 | ||
2453 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
2454 | { | |
2455 | struct clk *clk; | |
2456 | ||
2457 | mutex_lock(&of_clk_mutex); | |
2458 | clk = __of_clk_get_from_provider(clkspec); | |
2459 | mutex_unlock(&of_clk_mutex); | |
766e6a4e GL |
2460 | |
2461 | return clk; | |
2462 | } | |
2463 | ||
f6102742 MT |
2464 | int of_clk_get_parent_count(struct device_node *np) |
2465 | { | |
2466 | return of_count_phandle_with_args(np, "clocks", "#clock-cells"); | |
2467 | } | |
2468 | EXPORT_SYMBOL_GPL(of_clk_get_parent_count); | |
2469 | ||
766e6a4e GL |
2470 | const char *of_clk_get_parent_name(struct device_node *np, int index) |
2471 | { | |
2472 | struct of_phandle_args clkspec; | |
7a0fc1a3 | 2473 | struct property *prop; |
766e6a4e | 2474 | const char *clk_name; |
7a0fc1a3 BD |
2475 | const __be32 *vp; |
2476 | u32 pv; | |
766e6a4e | 2477 | int rc; |
7a0fc1a3 | 2478 | int count; |
766e6a4e GL |
2479 | |
2480 | if (index < 0) | |
2481 | return NULL; | |
2482 | ||
2483 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
2484 | &clkspec); | |
2485 | if (rc) | |
2486 | return NULL; | |
2487 | ||
7a0fc1a3 BD |
2488 | index = clkspec.args_count ? clkspec.args[0] : 0; |
2489 | count = 0; | |
2490 | ||
2491 | /* if there is an indices property, use it to transfer the index | |
2492 | * specified into an array offset for the clock-output-names property. | |
2493 | */ | |
2494 | of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) { | |
2495 | if (index == pv) { | |
2496 | index = count; | |
2497 | break; | |
2498 | } | |
2499 | count++; | |
2500 | } | |
2501 | ||
766e6a4e | 2502 | if (of_property_read_string_index(clkspec.np, "clock-output-names", |
7a0fc1a3 | 2503 | index, |
766e6a4e GL |
2504 | &clk_name) < 0) |
2505 | clk_name = clkspec.np->name; | |
2506 | ||
2507 | of_node_put(clkspec.np); | |
2508 | return clk_name; | |
2509 | } | |
2510 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
2511 | ||
1771b10d GC |
2512 | struct clock_provider { |
2513 | of_clk_init_cb_t clk_init_cb; | |
2514 | struct device_node *np; | |
2515 | struct list_head node; | |
2516 | }; | |
2517 | ||
2518 | static LIST_HEAD(clk_provider_list); | |
2519 | ||
2520 | /* | |
2521 | * This function looks for a parent clock. If there is one, then it | |
2522 | * checks that the provider for this parent clock was initialized, in | |
2523 | * this case the parent clock will be ready. | |
2524 | */ | |
2525 | static int parent_ready(struct device_node *np) | |
2526 | { | |
2527 | int i = 0; | |
2528 | ||
2529 | while (true) { | |
2530 | struct clk *clk = of_clk_get(np, i); | |
2531 | ||
2532 | /* this parent is ready we can check the next one */ | |
2533 | if (!IS_ERR(clk)) { | |
2534 | clk_put(clk); | |
2535 | i++; | |
2536 | continue; | |
2537 | } | |
2538 | ||
2539 | /* at least one parent is not ready, we exit now */ | |
2540 | if (PTR_ERR(clk) == -EPROBE_DEFER) | |
2541 | return 0; | |
2542 | ||
2543 | /* | |
2544 | * Here we make assumption that the device tree is | |
2545 | * written correctly. So an error means that there is | |
2546 | * no more parent. As we didn't exit yet, then the | |
2547 | * previous parent are ready. If there is no clock | |
2548 | * parent, no need to wait for them, then we can | |
2549 | * consider their absence as being ready | |
2550 | */ | |
2551 | return 1; | |
2552 | } | |
2553 | } | |
2554 | ||
766e6a4e GL |
2555 | /** |
2556 | * of_clk_init() - Scan and init clock providers from the DT | |
2557 | * @matches: array of compatible values and init functions for providers. | |
2558 | * | |
1771b10d | 2559 | * This function scans the device tree for matching clock providers |
e5ca8fb4 | 2560 | * and calls their initialization functions. It also does it by trying |
1771b10d | 2561 | * to follow the dependencies. |
766e6a4e GL |
2562 | */ |
2563 | void __init of_clk_init(const struct of_device_id *matches) | |
2564 | { | |
7f7ed584 | 2565 | const struct of_device_id *match; |
766e6a4e | 2566 | struct device_node *np; |
1771b10d GC |
2567 | struct clock_provider *clk_provider, *next; |
2568 | bool is_init_done; | |
2569 | bool force = false; | |
766e6a4e | 2570 | |
f2f6c255 | 2571 | if (!matches) |
819b4861 | 2572 | matches = &__clk_of_table; |
f2f6c255 | 2573 | |
1771b10d | 2574 | /* First prepare the list of the clocks providers */ |
7f7ed584 | 2575 | for_each_matching_node_and_match(np, matches, &match) { |
1771b10d GC |
2576 | struct clock_provider *parent = |
2577 | kzalloc(sizeof(struct clock_provider), GFP_KERNEL); | |
2578 | ||
2579 | parent->clk_init_cb = match->data; | |
2580 | parent->np = np; | |
3f6d439f | 2581 | list_add_tail(&parent->node, &clk_provider_list); |
1771b10d GC |
2582 | } |
2583 | ||
2584 | while (!list_empty(&clk_provider_list)) { | |
2585 | is_init_done = false; | |
2586 | list_for_each_entry_safe(clk_provider, next, | |
2587 | &clk_provider_list, node) { | |
2588 | if (force || parent_ready(clk_provider->np)) { | |
86be408b | 2589 | |
1771b10d | 2590 | clk_provider->clk_init_cb(clk_provider->np); |
86be408b SN |
2591 | of_clk_set_defaults(clk_provider->np, true); |
2592 | ||
1771b10d GC |
2593 | list_del(&clk_provider->node); |
2594 | kfree(clk_provider); | |
2595 | is_init_done = true; | |
2596 | } | |
2597 | } | |
2598 | ||
2599 | /* | |
e5ca8fb4 | 2600 | * We didn't manage to initialize any of the |
1771b10d GC |
2601 | * remaining providers during the last loop, so now we |
2602 | * initialize all the remaining ones unconditionally | |
2603 | * in case the clock parent was not mandatory | |
2604 | */ | |
2605 | if (!is_init_done) | |
2606 | force = true; | |
766e6a4e GL |
2607 | } |
2608 | } | |
2609 | #endif |