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 | 102 | static int inited = 0; |
6314b679 SB |
103 | static DEFINE_MUTEX(clk_debug_lock); |
104 | static HLIST_HEAD(clk_debug_list); | |
b2476490 | 105 | |
6b44c854 SK |
106 | static struct hlist_head *all_lists[] = { |
107 | &clk_root_list, | |
108 | &clk_orphan_list, | |
109 | NULL, | |
110 | }; | |
111 | ||
112 | static struct hlist_head *orphan_list[] = { | |
113 | &clk_orphan_list, | |
114 | NULL, | |
115 | }; | |
116 | ||
1af599df PG |
117 | static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level) |
118 | { | |
119 | if (!c) | |
120 | return; | |
121 | ||
e59c5371 | 122 | seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n", |
1af599df PG |
123 | level * 3 + 1, "", |
124 | 30 - level * 3, c->name, | |
5279fc40 | 125 | c->enable_count, c->prepare_count, clk_get_rate(c), |
e59c5371 | 126 | clk_get_accuracy(c), clk_get_phase(c)); |
1af599df PG |
127 | } |
128 | ||
129 | static void clk_summary_show_subtree(struct seq_file *s, struct clk *c, | |
130 | int level) | |
131 | { | |
132 | struct clk *child; | |
1af599df PG |
133 | |
134 | if (!c) | |
135 | return; | |
136 | ||
137 | clk_summary_show_one(s, c, level); | |
138 | ||
b67bfe0d | 139 | hlist_for_each_entry(child, &c->children, child_node) |
1af599df PG |
140 | clk_summary_show_subtree(s, child, level + 1); |
141 | } | |
142 | ||
143 | static int clk_summary_show(struct seq_file *s, void *data) | |
144 | { | |
145 | struct clk *c; | |
27b8d5f7 | 146 | struct hlist_head **lists = (struct hlist_head **)s->private; |
1af599df | 147 | |
e59c5371 MT |
148 | seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n"); |
149 | seq_puts(s, "----------------------------------------------------------------------------------------\n"); | |
1af599df | 150 | |
eab89f69 | 151 | clk_prepare_lock(); |
1af599df | 152 | |
27b8d5f7 PDS |
153 | for (; *lists; lists++) |
154 | hlist_for_each_entry(c, *lists, child_node) | |
155 | clk_summary_show_subtree(s, c, 0); | |
1af599df | 156 | |
eab89f69 | 157 | clk_prepare_unlock(); |
1af599df PG |
158 | |
159 | return 0; | |
160 | } | |
161 | ||
162 | ||
163 | static int clk_summary_open(struct inode *inode, struct file *file) | |
164 | { | |
165 | return single_open(file, clk_summary_show, inode->i_private); | |
166 | } | |
167 | ||
168 | static const struct file_operations clk_summary_fops = { | |
169 | .open = clk_summary_open, | |
170 | .read = seq_read, | |
171 | .llseek = seq_lseek, | |
172 | .release = single_release, | |
173 | }; | |
174 | ||
bddca894 PG |
175 | static void clk_dump_one(struct seq_file *s, struct clk *c, int level) |
176 | { | |
177 | if (!c) | |
178 | return; | |
179 | ||
180 | seq_printf(s, "\"%s\": { ", c->name); | |
181 | seq_printf(s, "\"enable_count\": %d,", c->enable_count); | |
182 | seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); | |
670decdd | 183 | seq_printf(s, "\"rate\": %lu", clk_get_rate(c)); |
5279fc40 | 184 | seq_printf(s, "\"accuracy\": %lu", clk_get_accuracy(c)); |
e59c5371 | 185 | seq_printf(s, "\"phase\": %d", clk_get_phase(c)); |
bddca894 PG |
186 | } |
187 | ||
188 | static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) | |
189 | { | |
190 | struct clk *child; | |
bddca894 PG |
191 | |
192 | if (!c) | |
193 | return; | |
194 | ||
195 | clk_dump_one(s, c, level); | |
196 | ||
b67bfe0d | 197 | hlist_for_each_entry(child, &c->children, child_node) { |
bddca894 PG |
198 | seq_printf(s, ","); |
199 | clk_dump_subtree(s, child, level + 1); | |
200 | } | |
201 | ||
202 | seq_printf(s, "}"); | |
203 | } | |
204 | ||
205 | static int clk_dump(struct seq_file *s, void *data) | |
206 | { | |
207 | struct clk *c; | |
bddca894 | 208 | bool first_node = true; |
27b8d5f7 | 209 | struct hlist_head **lists = (struct hlist_head **)s->private; |
bddca894 PG |
210 | |
211 | seq_printf(s, "{"); | |
212 | ||
eab89f69 | 213 | clk_prepare_lock(); |
bddca894 | 214 | |
27b8d5f7 PDS |
215 | for (; *lists; lists++) { |
216 | hlist_for_each_entry(c, *lists, child_node) { | |
217 | if (!first_node) | |
218 | seq_puts(s, ","); | |
219 | first_node = false; | |
220 | clk_dump_subtree(s, c, 0); | |
221 | } | |
bddca894 PG |
222 | } |
223 | ||
eab89f69 | 224 | clk_prepare_unlock(); |
bddca894 PG |
225 | |
226 | seq_printf(s, "}"); | |
227 | return 0; | |
228 | } | |
229 | ||
230 | ||
231 | static int clk_dump_open(struct inode *inode, struct file *file) | |
232 | { | |
233 | return single_open(file, clk_dump, inode->i_private); | |
234 | } | |
235 | ||
236 | static const struct file_operations clk_dump_fops = { | |
237 | .open = clk_dump_open, | |
238 | .read = seq_read, | |
239 | .llseek = seq_lseek, | |
240 | .release = single_release, | |
241 | }; | |
242 | ||
b2476490 MT |
243 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) |
244 | { | |
245 | struct dentry *d; | |
246 | int ret = -ENOMEM; | |
247 | ||
248 | if (!clk || !pdentry) { | |
249 | ret = -EINVAL; | |
250 | goto out; | |
251 | } | |
252 | ||
253 | d = debugfs_create_dir(clk->name, pdentry); | |
254 | if (!d) | |
255 | goto out; | |
256 | ||
257 | clk->dentry = d; | |
258 | ||
259 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, | |
260 | (u32 *)&clk->rate); | |
261 | if (!d) | |
262 | goto err_out; | |
263 | ||
5279fc40 BB |
264 | d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry, |
265 | (u32 *)&clk->accuracy); | |
266 | if (!d) | |
267 | goto err_out; | |
268 | ||
e59c5371 MT |
269 | d = debugfs_create_u32("clk_phase", S_IRUGO, clk->dentry, |
270 | (u32 *)&clk->phase); | |
271 | if (!d) | |
272 | goto err_out; | |
273 | ||
b2476490 MT |
274 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, |
275 | (u32 *)&clk->flags); | |
276 | if (!d) | |
277 | goto err_out; | |
278 | ||
279 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, | |
280 | (u32 *)&clk->prepare_count); | |
281 | if (!d) | |
282 | goto err_out; | |
283 | ||
284 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, | |
285 | (u32 *)&clk->enable_count); | |
286 | if (!d) | |
287 | goto err_out; | |
288 | ||
289 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, | |
290 | (u32 *)&clk->notifier_count); | |
291 | if (!d) | |
292 | goto err_out; | |
293 | ||
abeab450 CB |
294 | if (clk->ops->debug_init) { |
295 | ret = clk->ops->debug_init(clk->hw, clk->dentry); | |
296 | if (ret) | |
c646cbf1 | 297 | goto err_out; |
abeab450 | 298 | } |
c646cbf1 | 299 | |
b2476490 MT |
300 | ret = 0; |
301 | goto out; | |
302 | ||
303 | err_out: | |
b5f98e65 AE |
304 | debugfs_remove_recursive(clk->dentry); |
305 | clk->dentry = NULL; | |
b2476490 MT |
306 | out: |
307 | return ret; | |
308 | } | |
309 | ||
b2476490 MT |
310 | /** |
311 | * clk_debug_register - add a clk node to the debugfs clk tree | |
312 | * @clk: the clk being added to the debugfs clk tree | |
313 | * | |
314 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been | |
315 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
316 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
b2476490 MT |
317 | */ |
318 | static int clk_debug_register(struct clk *clk) | |
319 | { | |
b2476490 MT |
320 | int ret = 0; |
321 | ||
6314b679 SB |
322 | mutex_lock(&clk_debug_lock); |
323 | hlist_add_head(&clk->debug_node, &clk_debug_list); | |
324 | ||
b2476490 | 325 | if (!inited) |
6314b679 | 326 | goto unlock; |
b2476490 | 327 | |
6314b679 SB |
328 | ret = clk_debug_create_one(clk, rootdir); |
329 | unlock: | |
330 | mutex_unlock(&clk_debug_lock); | |
b2476490 | 331 | |
b2476490 MT |
332 | return ret; |
333 | } | |
334 | ||
fcb0ee6a SN |
335 | /** |
336 | * clk_debug_unregister - remove a clk node from the debugfs clk tree | |
337 | * @clk: the clk being removed from the debugfs clk tree | |
338 | * | |
339 | * Dynamically removes a clk and all it's children clk nodes from the | |
340 | * debugfs clk tree if clk->dentry points to debugfs created by | |
341 | * clk_debug_register in __clk_init. | |
fcb0ee6a SN |
342 | */ |
343 | static void clk_debug_unregister(struct clk *clk) | |
344 | { | |
6314b679 SB |
345 | mutex_lock(&clk_debug_lock); |
346 | if (!clk->dentry) | |
347 | goto out; | |
348 | ||
349 | hlist_del_init(&clk->debug_node); | |
fcb0ee6a | 350 | debugfs_remove_recursive(clk->dentry); |
6314b679 SB |
351 | clk->dentry = NULL; |
352 | out: | |
353 | mutex_unlock(&clk_debug_lock); | |
fcb0ee6a SN |
354 | } |
355 | ||
61c7cddf | 356 | struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode, |
fb2b3c9f PDS |
357 | void *data, const struct file_operations *fops) |
358 | { | |
359 | struct dentry *d = NULL; | |
360 | ||
61c7cddf TV |
361 | if (hw->clk->dentry) |
362 | d = debugfs_create_file(name, mode, hw->clk->dentry, data, fops); | |
fb2b3c9f PDS |
363 | |
364 | return d; | |
365 | } | |
366 | EXPORT_SYMBOL_GPL(clk_debugfs_add_file); | |
367 | ||
b2476490 MT |
368 | /** |
369 | * clk_debug_init - lazily create the debugfs clk tree visualization | |
370 | * | |
371 | * clks are often initialized very early during boot before memory can | |
372 | * be dynamically allocated and well before debugfs is setup. | |
373 | * clk_debug_init walks the clk tree hierarchy while holding | |
374 | * prepare_lock and creates the topology as part of a late_initcall, | |
375 | * thus insuring that clks initialized very early will still be | |
376 | * represented in the debugfs clk tree. This function should only be | |
377 | * called once at boot-time, and all other clks added dynamically will | |
378 | * be done so with clk_debug_register. | |
379 | */ | |
380 | static int __init clk_debug_init(void) | |
381 | { | |
382 | struct clk *clk; | |
1af599df | 383 | struct dentry *d; |
b2476490 MT |
384 | |
385 | rootdir = debugfs_create_dir("clk", NULL); | |
386 | ||
387 | if (!rootdir) | |
388 | return -ENOMEM; | |
389 | ||
27b8d5f7 | 390 | d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists, |
1af599df PG |
391 | &clk_summary_fops); |
392 | if (!d) | |
393 | return -ENOMEM; | |
394 | ||
27b8d5f7 | 395 | d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists, |
bddca894 PG |
396 | &clk_dump_fops); |
397 | if (!d) | |
398 | return -ENOMEM; | |
399 | ||
27b8d5f7 PDS |
400 | d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir, |
401 | &orphan_list, &clk_summary_fops); | |
402 | if (!d) | |
403 | return -ENOMEM; | |
b2476490 | 404 | |
27b8d5f7 PDS |
405 | d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir, |
406 | &orphan_list, &clk_dump_fops); | |
407 | if (!d) | |
b2476490 MT |
408 | return -ENOMEM; |
409 | ||
6314b679 SB |
410 | mutex_lock(&clk_debug_lock); |
411 | hlist_for_each_entry(clk, &clk_debug_list, debug_node) | |
412 | clk_debug_create_one(clk, rootdir); | |
b2476490 MT |
413 | |
414 | inited = 1; | |
6314b679 | 415 | mutex_unlock(&clk_debug_lock); |
b2476490 MT |
416 | |
417 | return 0; | |
418 | } | |
419 | late_initcall(clk_debug_init); | |
420 | #else | |
421 | static inline int clk_debug_register(struct clk *clk) { return 0; } | |
b33d212f UH |
422 | static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent) |
423 | { | |
424 | } | |
fcb0ee6a SN |
425 | static inline void clk_debug_unregister(struct clk *clk) |
426 | { | |
427 | } | |
70d347e6 | 428 | #endif |
b2476490 | 429 | |
1c155b3d UH |
430 | /* caller must hold prepare_lock */ |
431 | static void clk_unprepare_unused_subtree(struct clk *clk) | |
432 | { | |
433 | struct clk *child; | |
434 | ||
435 | if (!clk) | |
436 | return; | |
437 | ||
438 | hlist_for_each_entry(child, &clk->children, child_node) | |
439 | clk_unprepare_unused_subtree(child); | |
440 | ||
441 | if (clk->prepare_count) | |
442 | return; | |
443 | ||
444 | if (clk->flags & CLK_IGNORE_UNUSED) | |
445 | return; | |
446 | ||
3cc8247f UH |
447 | if (__clk_is_prepared(clk)) { |
448 | if (clk->ops->unprepare_unused) | |
449 | clk->ops->unprepare_unused(clk->hw); | |
450 | else if (clk->ops->unprepare) | |
1c155b3d | 451 | clk->ops->unprepare(clk->hw); |
3cc8247f | 452 | } |
1c155b3d UH |
453 | } |
454 | ||
b2476490 MT |
455 | /* caller must hold prepare_lock */ |
456 | static void clk_disable_unused_subtree(struct clk *clk) | |
457 | { | |
458 | struct clk *child; | |
b2476490 MT |
459 | unsigned long flags; |
460 | ||
461 | if (!clk) | |
462 | goto out; | |
463 | ||
b67bfe0d | 464 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
465 | clk_disable_unused_subtree(child); |
466 | ||
eab89f69 | 467 | flags = clk_enable_lock(); |
b2476490 MT |
468 | |
469 | if (clk->enable_count) | |
470 | goto unlock_out; | |
471 | ||
472 | if (clk->flags & CLK_IGNORE_UNUSED) | |
473 | goto unlock_out; | |
474 | ||
7c045a55 MT |
475 | /* |
476 | * some gate clocks have special needs during the disable-unused | |
477 | * sequence. call .disable_unused if available, otherwise fall | |
478 | * back to .disable | |
479 | */ | |
480 | if (__clk_is_enabled(clk)) { | |
481 | if (clk->ops->disable_unused) | |
482 | clk->ops->disable_unused(clk->hw); | |
483 | else if (clk->ops->disable) | |
484 | clk->ops->disable(clk->hw); | |
485 | } | |
b2476490 MT |
486 | |
487 | unlock_out: | |
eab89f69 | 488 | clk_enable_unlock(flags); |
b2476490 MT |
489 | |
490 | out: | |
491 | return; | |
492 | } | |
493 | ||
1e435256 OJ |
494 | static bool clk_ignore_unused; |
495 | static int __init clk_ignore_unused_setup(char *__unused) | |
496 | { | |
497 | clk_ignore_unused = true; | |
498 | return 1; | |
499 | } | |
500 | __setup("clk_ignore_unused", clk_ignore_unused_setup); | |
501 | ||
b2476490 MT |
502 | static int clk_disable_unused(void) |
503 | { | |
504 | struct clk *clk; | |
b2476490 | 505 | |
1e435256 OJ |
506 | if (clk_ignore_unused) { |
507 | pr_warn("clk: Not disabling unused clocks\n"); | |
508 | return 0; | |
509 | } | |
510 | ||
eab89f69 | 511 | clk_prepare_lock(); |
b2476490 | 512 | |
b67bfe0d | 513 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
514 | clk_disable_unused_subtree(clk); |
515 | ||
b67bfe0d | 516 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
b2476490 MT |
517 | clk_disable_unused_subtree(clk); |
518 | ||
1c155b3d UH |
519 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
520 | clk_unprepare_unused_subtree(clk); | |
521 | ||
522 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) | |
523 | clk_unprepare_unused_subtree(clk); | |
524 | ||
eab89f69 | 525 | clk_prepare_unlock(); |
b2476490 MT |
526 | |
527 | return 0; | |
528 | } | |
d41d5805 | 529 | late_initcall_sync(clk_disable_unused); |
b2476490 MT |
530 | |
531 | /*** helper functions ***/ | |
532 | ||
65800b2c | 533 | const char *__clk_get_name(struct clk *clk) |
b2476490 MT |
534 | { |
535 | return !clk ? NULL : clk->name; | |
536 | } | |
4895084c | 537 | EXPORT_SYMBOL_GPL(__clk_get_name); |
b2476490 | 538 | |
65800b2c | 539 | struct clk_hw *__clk_get_hw(struct clk *clk) |
b2476490 MT |
540 | { |
541 | return !clk ? NULL : clk->hw; | |
542 | } | |
0b7f04b8 | 543 | EXPORT_SYMBOL_GPL(__clk_get_hw); |
b2476490 | 544 | |
65800b2c | 545 | u8 __clk_get_num_parents(struct clk *clk) |
b2476490 | 546 | { |
2ac6b1f5 | 547 | return !clk ? 0 : clk->num_parents; |
b2476490 | 548 | } |
0b7f04b8 | 549 | EXPORT_SYMBOL_GPL(__clk_get_num_parents); |
b2476490 | 550 | |
65800b2c | 551 | struct clk *__clk_get_parent(struct clk *clk) |
b2476490 MT |
552 | { |
553 | return !clk ? NULL : clk->parent; | |
554 | } | |
0b7f04b8 | 555 | EXPORT_SYMBOL_GPL(__clk_get_parent); |
b2476490 | 556 | |
7ef3dcc8 JH |
557 | struct clk *clk_get_parent_by_index(struct clk *clk, u8 index) |
558 | { | |
559 | if (!clk || index >= clk->num_parents) | |
560 | return NULL; | |
561 | else if (!clk->parents) | |
562 | return __clk_lookup(clk->parent_names[index]); | |
563 | else if (!clk->parents[index]) | |
564 | return clk->parents[index] = | |
565 | __clk_lookup(clk->parent_names[index]); | |
566 | else | |
567 | return clk->parents[index]; | |
568 | } | |
0b7f04b8 | 569 | EXPORT_SYMBOL_GPL(clk_get_parent_by_index); |
7ef3dcc8 | 570 | |
65800b2c | 571 | unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 572 | { |
2ac6b1f5 | 573 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
574 | } |
575 | ||
b2476490 MT |
576 | unsigned long __clk_get_rate(struct clk *clk) |
577 | { | |
578 | unsigned long ret; | |
579 | ||
580 | if (!clk) { | |
34e44fe8 | 581 | ret = 0; |
b2476490 MT |
582 | goto out; |
583 | } | |
584 | ||
585 | ret = clk->rate; | |
586 | ||
587 | if (clk->flags & CLK_IS_ROOT) | |
588 | goto out; | |
589 | ||
590 | if (!clk->parent) | |
34e44fe8 | 591 | ret = 0; |
b2476490 MT |
592 | |
593 | out: | |
594 | return ret; | |
595 | } | |
0b7f04b8 | 596 | EXPORT_SYMBOL_GPL(__clk_get_rate); |
b2476490 | 597 | |
920f1c74 | 598 | static unsigned long __clk_get_accuracy(struct clk *clk) |
5279fc40 BB |
599 | { |
600 | if (!clk) | |
601 | return 0; | |
602 | ||
603 | return clk->accuracy; | |
604 | } | |
605 | ||
65800b2c | 606 | unsigned long __clk_get_flags(struct clk *clk) |
b2476490 | 607 | { |
2ac6b1f5 | 608 | return !clk ? 0 : clk->flags; |
b2476490 | 609 | } |
b05c6836 | 610 | EXPORT_SYMBOL_GPL(__clk_get_flags); |
b2476490 | 611 | |
3d6ee287 UH |
612 | bool __clk_is_prepared(struct clk *clk) |
613 | { | |
614 | int ret; | |
615 | ||
616 | if (!clk) | |
617 | return false; | |
618 | ||
619 | /* | |
620 | * .is_prepared is optional for clocks that can prepare | |
621 | * fall back to software usage counter if it is missing | |
622 | */ | |
623 | if (!clk->ops->is_prepared) { | |
624 | ret = clk->prepare_count ? 1 : 0; | |
625 | goto out; | |
626 | } | |
627 | ||
628 | ret = clk->ops->is_prepared(clk->hw); | |
629 | out: | |
630 | return !!ret; | |
631 | } | |
632 | ||
2ac6b1f5 | 633 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
634 | { |
635 | int ret; | |
636 | ||
637 | if (!clk) | |
2ac6b1f5 | 638 | return false; |
b2476490 MT |
639 | |
640 | /* | |
641 | * .is_enabled is only mandatory for clocks that gate | |
642 | * fall back to software usage counter if .is_enabled is missing | |
643 | */ | |
644 | if (!clk->ops->is_enabled) { | |
645 | ret = clk->enable_count ? 1 : 0; | |
646 | goto out; | |
647 | } | |
648 | ||
649 | ret = clk->ops->is_enabled(clk->hw); | |
650 | out: | |
2ac6b1f5 | 651 | return !!ret; |
b2476490 | 652 | } |
0b7f04b8 | 653 | EXPORT_SYMBOL_GPL(__clk_is_enabled); |
b2476490 MT |
654 | |
655 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
656 | { | |
657 | struct clk *child; | |
658 | struct clk *ret; | |
b2476490 MT |
659 | |
660 | if (!strcmp(clk->name, name)) | |
661 | return clk; | |
662 | ||
b67bfe0d | 663 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
664 | ret = __clk_lookup_subtree(name, child); |
665 | if (ret) | |
666 | return ret; | |
667 | } | |
668 | ||
669 | return NULL; | |
670 | } | |
671 | ||
672 | struct clk *__clk_lookup(const char *name) | |
673 | { | |
674 | struct clk *root_clk; | |
675 | struct clk *ret; | |
b2476490 MT |
676 | |
677 | if (!name) | |
678 | return NULL; | |
679 | ||
680 | /* search the 'proper' clk tree first */ | |
b67bfe0d | 681 | hlist_for_each_entry(root_clk, &clk_root_list, child_node) { |
b2476490 MT |
682 | ret = __clk_lookup_subtree(name, root_clk); |
683 | if (ret) | |
684 | return ret; | |
685 | } | |
686 | ||
687 | /* if not found, then search the orphan tree */ | |
b67bfe0d | 688 | hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { |
b2476490 MT |
689 | ret = __clk_lookup_subtree(name, root_clk); |
690 | if (ret) | |
691 | return ret; | |
692 | } | |
693 | ||
694 | return NULL; | |
695 | } | |
696 | ||
e366fdd7 JH |
697 | /* |
698 | * Helper for finding best parent to provide a given frequency. This can be used | |
699 | * directly as a determine_rate callback (e.g. for a mux), or from a more | |
700 | * complex clock that may combine a mux with other operations. | |
701 | */ | |
702 | long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, | |
703 | unsigned long *best_parent_rate, | |
646cafc6 | 704 | struct clk_hw **best_parent_p) |
e366fdd7 JH |
705 | { |
706 | struct clk *clk = hw->clk, *parent, *best_parent = NULL; | |
707 | int i, num_parents; | |
708 | unsigned long parent_rate, best = 0; | |
709 | ||
710 | /* if NO_REPARENT flag set, pass through to current parent */ | |
711 | if (clk->flags & CLK_SET_RATE_NO_REPARENT) { | |
712 | parent = clk->parent; | |
713 | if (clk->flags & CLK_SET_RATE_PARENT) | |
714 | best = __clk_round_rate(parent, rate); | |
715 | else if (parent) | |
716 | best = __clk_get_rate(parent); | |
717 | else | |
718 | best = __clk_get_rate(clk); | |
719 | goto out; | |
720 | } | |
721 | ||
722 | /* find the parent that can provide the fastest rate <= rate */ | |
723 | num_parents = clk->num_parents; | |
724 | for (i = 0; i < num_parents; i++) { | |
725 | parent = clk_get_parent_by_index(clk, i); | |
726 | if (!parent) | |
727 | continue; | |
728 | if (clk->flags & CLK_SET_RATE_PARENT) | |
729 | parent_rate = __clk_round_rate(parent, rate); | |
730 | else | |
731 | parent_rate = __clk_get_rate(parent); | |
732 | if (parent_rate <= rate && parent_rate > best) { | |
733 | best_parent = parent; | |
734 | best = parent_rate; | |
735 | } | |
736 | } | |
737 | ||
738 | out: | |
739 | if (best_parent) | |
646cafc6 | 740 | *best_parent_p = best_parent->hw; |
e366fdd7 JH |
741 | *best_parent_rate = best; |
742 | ||
743 | return best; | |
744 | } | |
0b7f04b8 | 745 | EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); |
e366fdd7 | 746 | |
b2476490 MT |
747 | /*** clk api ***/ |
748 | ||
749 | void __clk_unprepare(struct clk *clk) | |
750 | { | |
751 | if (!clk) | |
752 | return; | |
753 | ||
754 | if (WARN_ON(clk->prepare_count == 0)) | |
755 | return; | |
756 | ||
757 | if (--clk->prepare_count > 0) | |
758 | return; | |
759 | ||
760 | WARN_ON(clk->enable_count > 0); | |
761 | ||
762 | if (clk->ops->unprepare) | |
763 | clk->ops->unprepare(clk->hw); | |
764 | ||
765 | __clk_unprepare(clk->parent); | |
766 | } | |
767 | ||
768 | /** | |
769 | * clk_unprepare - undo preparation of a clock source | |
24ee1a08 | 770 | * @clk: the clk being unprepared |
b2476490 MT |
771 | * |
772 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
773 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
774 | * if the operation may sleep. One example is a clk which is accessed over | |
775 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
776 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
777 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
778 | */ | |
779 | void clk_unprepare(struct clk *clk) | |
780 | { | |
63589e92 SB |
781 | if (IS_ERR_OR_NULL(clk)) |
782 | return; | |
783 | ||
eab89f69 | 784 | clk_prepare_lock(); |
b2476490 | 785 | __clk_unprepare(clk); |
eab89f69 | 786 | clk_prepare_unlock(); |
b2476490 MT |
787 | } |
788 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
789 | ||
790 | int __clk_prepare(struct clk *clk) | |
791 | { | |
792 | int ret = 0; | |
793 | ||
794 | if (!clk) | |
795 | return 0; | |
796 | ||
797 | if (clk->prepare_count == 0) { | |
798 | ret = __clk_prepare(clk->parent); | |
799 | if (ret) | |
800 | return ret; | |
801 | ||
802 | if (clk->ops->prepare) { | |
803 | ret = clk->ops->prepare(clk->hw); | |
804 | if (ret) { | |
805 | __clk_unprepare(clk->parent); | |
806 | return ret; | |
807 | } | |
808 | } | |
809 | } | |
810 | ||
811 | clk->prepare_count++; | |
812 | ||
813 | return 0; | |
814 | } | |
815 | ||
816 | /** | |
817 | * clk_prepare - prepare a clock source | |
818 | * @clk: the clk being prepared | |
819 | * | |
820 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
821 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
822 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
823 | * the complex case a clk ungate operation may require a fast and a slow part. | |
824 | * It is this reason that clk_prepare and clk_enable are not mutually | |
825 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
826 | * Returns 0 on success, -EERROR otherwise. | |
827 | */ | |
828 | int clk_prepare(struct clk *clk) | |
829 | { | |
830 | int ret; | |
831 | ||
eab89f69 | 832 | clk_prepare_lock(); |
b2476490 | 833 | ret = __clk_prepare(clk); |
eab89f69 | 834 | clk_prepare_unlock(); |
b2476490 MT |
835 | |
836 | return ret; | |
837 | } | |
838 | EXPORT_SYMBOL_GPL(clk_prepare); | |
839 | ||
840 | static void __clk_disable(struct clk *clk) | |
841 | { | |
842 | if (!clk) | |
843 | return; | |
844 | ||
845 | if (WARN_ON(clk->enable_count == 0)) | |
846 | return; | |
847 | ||
848 | if (--clk->enable_count > 0) | |
849 | return; | |
850 | ||
851 | if (clk->ops->disable) | |
852 | clk->ops->disable(clk->hw); | |
853 | ||
854 | __clk_disable(clk->parent); | |
855 | } | |
856 | ||
857 | /** | |
858 | * clk_disable - gate a clock | |
859 | * @clk: the clk being gated | |
860 | * | |
861 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
862 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
863 | * clk if the operation is fast and will never sleep. One example is a | |
864 | * SoC-internal clk which is controlled via simple register writes. In the | |
865 | * complex case a clk gate operation may require a fast and a slow part. It is | |
866 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
867 | * In fact clk_disable must be called before clk_unprepare. | |
868 | */ | |
869 | void clk_disable(struct clk *clk) | |
870 | { | |
871 | unsigned long flags; | |
872 | ||
63589e92 SB |
873 | if (IS_ERR_OR_NULL(clk)) |
874 | return; | |
875 | ||
eab89f69 | 876 | flags = clk_enable_lock(); |
b2476490 | 877 | __clk_disable(clk); |
eab89f69 | 878 | clk_enable_unlock(flags); |
b2476490 MT |
879 | } |
880 | EXPORT_SYMBOL_GPL(clk_disable); | |
881 | ||
882 | static int __clk_enable(struct clk *clk) | |
883 | { | |
884 | int ret = 0; | |
885 | ||
886 | if (!clk) | |
887 | return 0; | |
888 | ||
889 | if (WARN_ON(clk->prepare_count == 0)) | |
890 | return -ESHUTDOWN; | |
891 | ||
892 | if (clk->enable_count == 0) { | |
893 | ret = __clk_enable(clk->parent); | |
894 | ||
895 | if (ret) | |
896 | return ret; | |
897 | ||
898 | if (clk->ops->enable) { | |
899 | ret = clk->ops->enable(clk->hw); | |
900 | if (ret) { | |
901 | __clk_disable(clk->parent); | |
902 | return ret; | |
903 | } | |
904 | } | |
905 | } | |
906 | ||
907 | clk->enable_count++; | |
908 | return 0; | |
909 | } | |
910 | ||
911 | /** | |
912 | * clk_enable - ungate a clock | |
913 | * @clk: the clk being ungated | |
914 | * | |
915 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
916 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
917 | * if the operation will never sleep. One example is a SoC-internal clk which | |
918 | * is controlled via simple register writes. In the complex case a clk ungate | |
919 | * operation may require a fast and a slow part. It is this reason that | |
920 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
921 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
922 | * otherwise. | |
923 | */ | |
924 | int clk_enable(struct clk *clk) | |
925 | { | |
926 | unsigned long flags; | |
927 | int ret; | |
928 | ||
eab89f69 | 929 | flags = clk_enable_lock(); |
b2476490 | 930 | ret = __clk_enable(clk); |
eab89f69 | 931 | clk_enable_unlock(flags); |
b2476490 MT |
932 | |
933 | return ret; | |
934 | } | |
935 | EXPORT_SYMBOL_GPL(clk_enable); | |
936 | ||
b2476490 MT |
937 | /** |
938 | * __clk_round_rate - round the given rate for a clk | |
939 | * @clk: round the rate of this clock | |
24ee1a08 | 940 | * @rate: the rate which is to be rounded |
b2476490 MT |
941 | * |
942 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
943 | */ | |
944 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
945 | { | |
81536e07 | 946 | unsigned long parent_rate = 0; |
71472c0c | 947 | struct clk *parent; |
646cafc6 | 948 | struct clk_hw *parent_hw; |
b2476490 MT |
949 | |
950 | if (!clk) | |
2ac6b1f5 | 951 | return 0; |
b2476490 | 952 | |
71472c0c JH |
953 | parent = clk->parent; |
954 | if (parent) | |
955 | parent_rate = parent->rate; | |
956 | ||
646cafc6 TV |
957 | if (clk->ops->determine_rate) { |
958 | parent_hw = parent ? parent->hw : NULL; | |
71472c0c | 959 | return clk->ops->determine_rate(clk->hw, rate, &parent_rate, |
646cafc6 TV |
960 | &parent_hw); |
961 | } else if (clk->ops->round_rate) | |
71472c0c JH |
962 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); |
963 | else if (clk->flags & CLK_SET_RATE_PARENT) | |
964 | return __clk_round_rate(clk->parent, rate); | |
965 | else | |
966 | return clk->rate; | |
b2476490 | 967 | } |
1cdf8ee2 | 968 | EXPORT_SYMBOL_GPL(__clk_round_rate); |
b2476490 MT |
969 | |
970 | /** | |
971 | * clk_round_rate - round the given rate for a clk | |
972 | * @clk: the clk for which we are rounding a rate | |
973 | * @rate: the rate which is to be rounded | |
974 | * | |
975 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
976 | * use which is then returned. If clk doesn't support round_rate operation | |
977 | * then the parent rate is returned. | |
978 | */ | |
979 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
980 | { | |
981 | unsigned long ret; | |
982 | ||
eab89f69 | 983 | clk_prepare_lock(); |
b2476490 | 984 | ret = __clk_round_rate(clk, rate); |
eab89f69 | 985 | clk_prepare_unlock(); |
b2476490 MT |
986 | |
987 | return ret; | |
988 | } | |
989 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
990 | ||
991 | /** | |
992 | * __clk_notify - call clk notifier chain | |
993 | * @clk: struct clk * that is changing rate | |
994 | * @msg: clk notifier type (see include/linux/clk.h) | |
995 | * @old_rate: old clk rate | |
996 | * @new_rate: new clk rate | |
997 | * | |
998 | * Triggers a notifier call chain on the clk rate-change notification | |
999 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
1000 | * and current rates to the notifier callback. Intended to be called by | |
1001 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
1002 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
1003 | * a driver returns that. | |
1004 | */ | |
1005 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
1006 | unsigned long old_rate, unsigned long new_rate) | |
1007 | { | |
1008 | struct clk_notifier *cn; | |
1009 | struct clk_notifier_data cnd; | |
1010 | int ret = NOTIFY_DONE; | |
1011 | ||
1012 | cnd.clk = clk; | |
1013 | cnd.old_rate = old_rate; | |
1014 | cnd.new_rate = new_rate; | |
1015 | ||
1016 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
1017 | if (cn->clk == clk) { | |
1018 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
1019 | &cnd); | |
1020 | break; | |
1021 | } | |
1022 | } | |
1023 | ||
1024 | return ret; | |
1025 | } | |
1026 | ||
5279fc40 BB |
1027 | /** |
1028 | * __clk_recalc_accuracies | |
1029 | * @clk: first clk in the subtree | |
1030 | * | |
1031 | * Walks the subtree of clks starting with clk and recalculates accuracies as | |
1032 | * it goes. Note that if a clk does not implement the .recalc_accuracy | |
1033 | * callback then it is assumed that the clock will take on the accuracy of it's | |
1034 | * parent. | |
1035 | * | |
1036 | * Caller must hold prepare_lock. | |
1037 | */ | |
1038 | static void __clk_recalc_accuracies(struct clk *clk) | |
1039 | { | |
1040 | unsigned long parent_accuracy = 0; | |
1041 | struct clk *child; | |
1042 | ||
1043 | if (clk->parent) | |
1044 | parent_accuracy = clk->parent->accuracy; | |
1045 | ||
1046 | if (clk->ops->recalc_accuracy) | |
1047 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1048 | parent_accuracy); | |
1049 | else | |
1050 | clk->accuracy = parent_accuracy; | |
1051 | ||
1052 | hlist_for_each_entry(child, &clk->children, child_node) | |
1053 | __clk_recalc_accuracies(child); | |
1054 | } | |
1055 | ||
1056 | /** | |
1057 | * clk_get_accuracy - return the accuracy of clk | |
1058 | * @clk: the clk whose accuracy is being returned | |
1059 | * | |
1060 | * Simply returns the cached accuracy of the clk, unless | |
1061 | * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be | |
1062 | * issued. | |
1063 | * If clk is NULL then returns 0. | |
1064 | */ | |
1065 | long clk_get_accuracy(struct clk *clk) | |
1066 | { | |
1067 | unsigned long accuracy; | |
1068 | ||
1069 | clk_prepare_lock(); | |
1070 | if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE)) | |
1071 | __clk_recalc_accuracies(clk); | |
1072 | ||
1073 | accuracy = __clk_get_accuracy(clk); | |
1074 | clk_prepare_unlock(); | |
1075 | ||
1076 | return accuracy; | |
1077 | } | |
1078 | EXPORT_SYMBOL_GPL(clk_get_accuracy); | |
1079 | ||
8f2c2db1 SB |
1080 | static unsigned long clk_recalc(struct clk *clk, unsigned long parent_rate) |
1081 | { | |
1082 | if (clk->ops->recalc_rate) | |
1083 | return clk->ops->recalc_rate(clk->hw, parent_rate); | |
1084 | return parent_rate; | |
1085 | } | |
1086 | ||
b2476490 MT |
1087 | /** |
1088 | * __clk_recalc_rates | |
1089 | * @clk: first clk in the subtree | |
1090 | * @msg: notification type (see include/linux/clk.h) | |
1091 | * | |
1092 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
1093 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
24ee1a08 | 1094 | * it is assumed that the clock will take on the rate of its parent. |
b2476490 MT |
1095 | * |
1096 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
1097 | * if necessary. | |
1098 | * | |
1099 | * Caller must hold prepare_lock. | |
1100 | */ | |
1101 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
1102 | { | |
1103 | unsigned long old_rate; | |
1104 | unsigned long parent_rate = 0; | |
b2476490 MT |
1105 | struct clk *child; |
1106 | ||
1107 | old_rate = clk->rate; | |
1108 | ||
1109 | if (clk->parent) | |
1110 | parent_rate = clk->parent->rate; | |
1111 | ||
8f2c2db1 | 1112 | clk->rate = clk_recalc(clk, parent_rate); |
b2476490 MT |
1113 | |
1114 | /* | |
1115 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
1116 | * & ABORT_RATE_CHANGE notifiers | |
1117 | */ | |
1118 | if (clk->notifier_count && msg) | |
1119 | __clk_notify(clk, msg, old_rate, clk->rate); | |
1120 | ||
b67bfe0d | 1121 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
1122 | __clk_recalc_rates(child, msg); |
1123 | } | |
1124 | ||
a093bde2 UH |
1125 | /** |
1126 | * clk_get_rate - return the rate of clk | |
1127 | * @clk: the clk whose rate is being returned | |
1128 | * | |
1129 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
1130 | * is set, which means a recalc_rate will be issued. | |
1131 | * If clk is NULL then returns 0. | |
1132 | */ | |
1133 | unsigned long clk_get_rate(struct clk *clk) | |
1134 | { | |
1135 | unsigned long rate; | |
1136 | ||
eab89f69 | 1137 | clk_prepare_lock(); |
a093bde2 UH |
1138 | |
1139 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
1140 | __clk_recalc_rates(clk, 0); | |
1141 | ||
1142 | rate = __clk_get_rate(clk); | |
eab89f69 | 1143 | clk_prepare_unlock(); |
a093bde2 UH |
1144 | |
1145 | return rate; | |
1146 | } | |
1147 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
1148 | ||
f1c8b2ed | 1149 | static int clk_fetch_parent_index(struct clk *clk, struct clk *parent) |
4935b22c | 1150 | { |
f1c8b2ed | 1151 | int i; |
4935b22c | 1152 | |
f1c8b2ed | 1153 | if (!clk->parents) { |
96a7ed90 TF |
1154 | clk->parents = kcalloc(clk->num_parents, |
1155 | sizeof(struct clk *), GFP_KERNEL); | |
f1c8b2ed TF |
1156 | if (!clk->parents) |
1157 | return -ENOMEM; | |
1158 | } | |
4935b22c JH |
1159 | |
1160 | /* | |
1161 | * find index of new parent clock using cached parent ptrs, | |
1162 | * or if not yet cached, use string name comparison and cache | |
1163 | * them now to avoid future calls to __clk_lookup. | |
1164 | */ | |
1165 | for (i = 0; i < clk->num_parents; i++) { | |
da0f0b2c | 1166 | if (clk->parents[i] == parent) |
f1c8b2ed | 1167 | return i; |
da0f0b2c TF |
1168 | |
1169 | if (clk->parents[i]) | |
1170 | continue; | |
1171 | ||
1172 | if (!strcmp(clk->parent_names[i], parent->name)) { | |
1173 | clk->parents[i] = __clk_lookup(parent->name); | |
f1c8b2ed | 1174 | return i; |
4935b22c JH |
1175 | } |
1176 | } | |
1177 | ||
f1c8b2ed | 1178 | return -EINVAL; |
4935b22c JH |
1179 | } |
1180 | ||
1181 | static void clk_reparent(struct clk *clk, struct clk *new_parent) | |
1182 | { | |
1183 | hlist_del(&clk->child_node); | |
1184 | ||
903efc55 JH |
1185 | if (new_parent) { |
1186 | /* avoid duplicate POST_RATE_CHANGE notifications */ | |
1187 | if (new_parent->new_child == clk) | |
1188 | new_parent->new_child = NULL; | |
1189 | ||
4935b22c | 1190 | hlist_add_head(&clk->child_node, &new_parent->children); |
903efc55 | 1191 | } else { |
4935b22c | 1192 | hlist_add_head(&clk->child_node, &clk_orphan_list); |
903efc55 | 1193 | } |
4935b22c JH |
1194 | |
1195 | clk->parent = new_parent; | |
1196 | } | |
1197 | ||
3fa2252b | 1198 | static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent) |
4935b22c JH |
1199 | { |
1200 | unsigned long flags; | |
4935b22c JH |
1201 | struct clk *old_parent = clk->parent; |
1202 | ||
1203 | /* | |
1204 | * Migrate prepare state between parents and prevent race with | |
1205 | * clk_enable(). | |
1206 | * | |
1207 | * If the clock is not prepared, then a race with | |
1208 | * clk_enable/disable() is impossible since we already have the | |
1209 | * prepare lock (future calls to clk_enable() need to be preceded by | |
1210 | * a clk_prepare()). | |
1211 | * | |
1212 | * If the clock is prepared, migrate the prepared state to the new | |
1213 | * parent and also protect against a race with clk_enable() by | |
1214 | * forcing the clock and the new parent on. This ensures that all | |
1215 | * future calls to clk_enable() are practically NOPs with respect to | |
1216 | * hardware and software states. | |
1217 | * | |
1218 | * See also: Comment for clk_set_parent() below. | |
1219 | */ | |
1220 | if (clk->prepare_count) { | |
1221 | __clk_prepare(parent); | |
1222 | clk_enable(parent); | |
1223 | clk_enable(clk); | |
1224 | } | |
1225 | ||
1226 | /* update the clk tree topology */ | |
1227 | flags = clk_enable_lock(); | |
1228 | clk_reparent(clk, parent); | |
1229 | clk_enable_unlock(flags); | |
1230 | ||
3fa2252b SB |
1231 | return old_parent; |
1232 | } | |
1233 | ||
1234 | static void __clk_set_parent_after(struct clk *clk, struct clk *parent, | |
1235 | struct clk *old_parent) | |
1236 | { | |
1237 | /* | |
1238 | * Finish the migration of prepare state and undo the changes done | |
1239 | * for preventing a race with clk_enable(). | |
1240 | */ | |
1241 | if (clk->prepare_count) { | |
1242 | clk_disable(clk); | |
1243 | clk_disable(old_parent); | |
1244 | __clk_unprepare(old_parent); | |
1245 | } | |
3fa2252b SB |
1246 | } |
1247 | ||
1248 | static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) | |
1249 | { | |
1250 | unsigned long flags; | |
1251 | int ret = 0; | |
1252 | struct clk *old_parent; | |
1253 | ||
1254 | old_parent = __clk_set_parent_before(clk, parent); | |
1255 | ||
4935b22c JH |
1256 | /* change clock input source */ |
1257 | if (parent && clk->ops->set_parent) | |
1258 | ret = clk->ops->set_parent(clk->hw, p_index); | |
1259 | ||
1260 | if (ret) { | |
1261 | flags = clk_enable_lock(); | |
1262 | clk_reparent(clk, old_parent); | |
1263 | clk_enable_unlock(flags); | |
1264 | ||
1265 | if (clk->prepare_count) { | |
1266 | clk_disable(clk); | |
1267 | clk_disable(parent); | |
1268 | __clk_unprepare(parent); | |
1269 | } | |
1270 | return ret; | |
1271 | } | |
1272 | ||
3fa2252b | 1273 | __clk_set_parent_after(clk, parent, old_parent); |
4935b22c | 1274 | |
4935b22c JH |
1275 | return 0; |
1276 | } | |
1277 | ||
b2476490 MT |
1278 | /** |
1279 | * __clk_speculate_rates | |
1280 | * @clk: first clk in the subtree | |
1281 | * @parent_rate: the "future" rate of clk's parent | |
1282 | * | |
1283 | * Walks the subtree of clks starting with clk, speculating rates as it | |
1284 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
1285 | * | |
1286 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
1287 | * pre-rate change notifications and returns early if no clks in the | |
1288 | * subtree have subscribed to the notifications. Note that if a clk does not | |
1289 | * implement the .recalc_rate callback then it is assumed that the clock will | |
24ee1a08 | 1290 | * take on the rate of its parent. |
b2476490 MT |
1291 | * |
1292 | * Caller must hold prepare_lock. | |
1293 | */ | |
1294 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
1295 | { | |
b2476490 MT |
1296 | struct clk *child; |
1297 | unsigned long new_rate; | |
1298 | int ret = NOTIFY_DONE; | |
1299 | ||
8f2c2db1 | 1300 | new_rate = clk_recalc(clk, parent_rate); |
b2476490 | 1301 | |
fb72a059 | 1302 | /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ |
b2476490 MT |
1303 | if (clk->notifier_count) |
1304 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
1305 | ||
86bcfa2e MT |
1306 | if (ret & NOTIFY_STOP_MASK) { |
1307 | pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n", | |
1308 | __func__, clk->name, ret); | |
b2476490 | 1309 | goto out; |
86bcfa2e | 1310 | } |
b2476490 | 1311 | |
b67bfe0d | 1312 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 | 1313 | ret = __clk_speculate_rates(child, new_rate); |
fb72a059 | 1314 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1315 | break; |
1316 | } | |
1317 | ||
1318 | out: | |
1319 | return ret; | |
1320 | } | |
1321 | ||
71472c0c JH |
1322 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate, |
1323 | struct clk *new_parent, u8 p_index) | |
b2476490 MT |
1324 | { |
1325 | struct clk *child; | |
b2476490 MT |
1326 | |
1327 | clk->new_rate = new_rate; | |
71472c0c JH |
1328 | clk->new_parent = new_parent; |
1329 | clk->new_parent_index = p_index; | |
1330 | /* include clk in new parent's PRE_RATE_CHANGE notifications */ | |
1331 | clk->new_child = NULL; | |
1332 | if (new_parent && new_parent != clk->parent) | |
1333 | new_parent->new_child = clk; | |
b2476490 | 1334 | |
b67bfe0d | 1335 | hlist_for_each_entry(child, &clk->children, child_node) { |
8f2c2db1 | 1336 | child->new_rate = clk_recalc(child, new_rate); |
71472c0c | 1337 | clk_calc_subtree(child, child->new_rate, NULL, 0); |
b2476490 MT |
1338 | } |
1339 | } | |
1340 | ||
1341 | /* | |
1342 | * calculate the new rates returning the topmost clock that has to be | |
1343 | * changed. | |
1344 | */ | |
1345 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
1346 | { | |
1347 | struct clk *top = clk; | |
71472c0c | 1348 | struct clk *old_parent, *parent; |
646cafc6 | 1349 | struct clk_hw *parent_hw; |
81536e07 | 1350 | unsigned long best_parent_rate = 0; |
b2476490 | 1351 | unsigned long new_rate; |
f1c8b2ed | 1352 | int p_index = 0; |
b2476490 | 1353 | |
7452b219 MT |
1354 | /* sanity */ |
1355 | if (IS_ERR_OR_NULL(clk)) | |
1356 | return NULL; | |
1357 | ||
63f5c3b2 | 1358 | /* save parent rate, if it exists */ |
71472c0c JH |
1359 | parent = old_parent = clk->parent; |
1360 | if (parent) | |
1361 | best_parent_rate = parent->rate; | |
1362 | ||
1363 | /* find the closest rate and parent clk/rate */ | |
1364 | if (clk->ops->determine_rate) { | |
646cafc6 | 1365 | parent_hw = parent ? parent->hw : NULL; |
71472c0c JH |
1366 | new_rate = clk->ops->determine_rate(clk->hw, rate, |
1367 | &best_parent_rate, | |
646cafc6 | 1368 | &parent_hw); |
c7662fc5 | 1369 | parent = parent_hw ? parent_hw->clk : NULL; |
71472c0c JH |
1370 | } else if (clk->ops->round_rate) { |
1371 | new_rate = clk->ops->round_rate(clk->hw, rate, | |
1372 | &best_parent_rate); | |
1373 | } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) { | |
1374 | /* pass-through clock without adjustable parent */ | |
1375 | clk->new_rate = clk->rate; | |
1376 | return NULL; | |
1377 | } else { | |
1378 | /* pass-through clock with adjustable parent */ | |
1379 | top = clk_calc_new_rates(parent, rate); | |
1380 | new_rate = parent->new_rate; | |
63f5c3b2 | 1381 | goto out; |
7452b219 MT |
1382 | } |
1383 | ||
71472c0c JH |
1384 | /* some clocks must be gated to change parent */ |
1385 | if (parent != old_parent && | |
1386 | (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1387 | pr_debug("%s: %s not gated but wants to reparent\n", | |
1388 | __func__, clk->name); | |
b2476490 MT |
1389 | return NULL; |
1390 | } | |
1391 | ||
71472c0c JH |
1392 | /* try finding the new parent index */ |
1393 | if (parent) { | |
1394 | p_index = clk_fetch_parent_index(clk, parent); | |
f1c8b2ed | 1395 | if (p_index < 0) { |
71472c0c JH |
1396 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1397 | __func__, parent->name, clk->name); | |
1398 | return NULL; | |
1399 | } | |
b2476490 MT |
1400 | } |
1401 | ||
71472c0c JH |
1402 | if ((clk->flags & CLK_SET_RATE_PARENT) && parent && |
1403 | best_parent_rate != parent->rate) | |
1404 | top = clk_calc_new_rates(parent, best_parent_rate); | |
b2476490 MT |
1405 | |
1406 | out: | |
71472c0c | 1407 | clk_calc_subtree(clk, new_rate, parent, p_index); |
b2476490 MT |
1408 | |
1409 | return top; | |
1410 | } | |
1411 | ||
1412 | /* | |
1413 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
1414 | * so that in case of an error we can walk down the whole tree again and | |
1415 | * abort the change. | |
1416 | */ | |
1417 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
1418 | { | |
71472c0c | 1419 | struct clk *child, *tmp_clk, *fail_clk = NULL; |
b2476490 MT |
1420 | int ret = NOTIFY_DONE; |
1421 | ||
1422 | if (clk->rate == clk->new_rate) | |
5fda6858 | 1423 | return NULL; |
b2476490 MT |
1424 | |
1425 | if (clk->notifier_count) { | |
1426 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
fb72a059 | 1427 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1428 | fail_clk = clk; |
1429 | } | |
1430 | ||
b67bfe0d | 1431 | hlist_for_each_entry(child, &clk->children, child_node) { |
71472c0c JH |
1432 | /* Skip children who will be reparented to another clock */ |
1433 | if (child->new_parent && child->new_parent != clk) | |
1434 | continue; | |
1435 | tmp_clk = clk_propagate_rate_change(child, event); | |
1436 | if (tmp_clk) | |
1437 | fail_clk = tmp_clk; | |
1438 | } | |
1439 | ||
1440 | /* handle the new child who might not be in clk->children yet */ | |
1441 | if (clk->new_child) { | |
1442 | tmp_clk = clk_propagate_rate_change(clk->new_child, event); | |
1443 | if (tmp_clk) | |
1444 | fail_clk = tmp_clk; | |
b2476490 MT |
1445 | } |
1446 | ||
1447 | return fail_clk; | |
1448 | } | |
1449 | ||
1450 | /* | |
1451 | * walk down a subtree and set the new rates notifying the rate | |
1452 | * change on the way | |
1453 | */ | |
1454 | static void clk_change_rate(struct clk *clk) | |
1455 | { | |
1456 | struct clk *child; | |
067bb174 | 1457 | struct hlist_node *tmp; |
b2476490 | 1458 | unsigned long old_rate; |
bf47b4fd | 1459 | unsigned long best_parent_rate = 0; |
3fa2252b SB |
1460 | bool skip_set_rate = false; |
1461 | struct clk *old_parent; | |
b2476490 MT |
1462 | |
1463 | old_rate = clk->rate; | |
1464 | ||
3fa2252b SB |
1465 | if (clk->new_parent) |
1466 | best_parent_rate = clk->new_parent->rate; | |
1467 | else if (clk->parent) | |
bf47b4fd PM |
1468 | best_parent_rate = clk->parent->rate; |
1469 | ||
3fa2252b SB |
1470 | if (clk->new_parent && clk->new_parent != clk->parent) { |
1471 | old_parent = __clk_set_parent_before(clk, clk->new_parent); | |
1472 | ||
1473 | if (clk->ops->set_rate_and_parent) { | |
1474 | skip_set_rate = true; | |
1475 | clk->ops->set_rate_and_parent(clk->hw, clk->new_rate, | |
1476 | best_parent_rate, | |
1477 | clk->new_parent_index); | |
1478 | } else if (clk->ops->set_parent) { | |
1479 | clk->ops->set_parent(clk->hw, clk->new_parent_index); | |
1480 | } | |
1481 | ||
1482 | __clk_set_parent_after(clk, clk->new_parent, old_parent); | |
1483 | } | |
1484 | ||
1485 | if (!skip_set_rate && clk->ops->set_rate) | |
bf47b4fd | 1486 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 | 1487 | |
8f2c2db1 | 1488 | clk->rate = clk_recalc(clk, best_parent_rate); |
b2476490 MT |
1489 | |
1490 | if (clk->notifier_count && old_rate != clk->rate) | |
1491 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
1492 | ||
067bb174 TK |
1493 | /* |
1494 | * Use safe iteration, as change_rate can actually swap parents | |
1495 | * for certain clock types. | |
1496 | */ | |
1497 | hlist_for_each_entry_safe(child, tmp, &clk->children, child_node) { | |
71472c0c JH |
1498 | /* Skip children who will be reparented to another clock */ |
1499 | if (child->new_parent && child->new_parent != clk) | |
1500 | continue; | |
b2476490 | 1501 | clk_change_rate(child); |
71472c0c JH |
1502 | } |
1503 | ||
1504 | /* handle the new child who might not be in clk->children yet */ | |
1505 | if (clk->new_child) | |
1506 | clk_change_rate(clk->new_child); | |
b2476490 MT |
1507 | } |
1508 | ||
1509 | /** | |
1510 | * clk_set_rate - specify a new rate for clk | |
1511 | * @clk: the clk whose rate is being changed | |
1512 | * @rate: the new rate for clk | |
1513 | * | |
5654dc94 | 1514 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 1515 | * |
5654dc94 MT |
1516 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
1517 | * propagate up to clk's parent; whether or not this happens depends on the | |
1518 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
1519 | * after calling .round_rate then upstream parent propagation is ignored. If | |
1520 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
24ee1a08 | 1521 | * up to clk's parent and set its rate. Upward propagation will continue |
5654dc94 MT |
1522 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or |
1523 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 1524 | * |
5654dc94 MT |
1525 | * Rate changes are accomplished via tree traversal that also recalculates the |
1526 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
1527 | * |
1528 | * Returns 0 on success, -EERROR otherwise. | |
1529 | */ | |
1530 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
1531 | { | |
1532 | struct clk *top, *fail_clk; | |
1533 | int ret = 0; | |
1534 | ||
89ac8d7a MT |
1535 | if (!clk) |
1536 | return 0; | |
1537 | ||
b2476490 | 1538 | /* prevent racing with updates to the clock topology */ |
eab89f69 | 1539 | clk_prepare_lock(); |
b2476490 MT |
1540 | |
1541 | /* bail early if nothing to do */ | |
34e452a1 | 1542 | if (rate == clk_get_rate(clk)) |
b2476490 MT |
1543 | goto out; |
1544 | ||
7e0fa1b5 | 1545 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
1546 | ret = -EBUSY; |
1547 | goto out; | |
1548 | } | |
1549 | ||
b2476490 MT |
1550 | /* calculate new rates and get the topmost changed clock */ |
1551 | top = clk_calc_new_rates(clk, rate); | |
1552 | if (!top) { | |
1553 | ret = -EINVAL; | |
1554 | goto out; | |
1555 | } | |
1556 | ||
1557 | /* notify that we are about to change rates */ | |
1558 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
1559 | if (fail_clk) { | |
f7363861 | 1560 | pr_debug("%s: failed to set %s rate\n", __func__, |
b2476490 MT |
1561 | fail_clk->name); |
1562 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
1563 | ret = -EBUSY; | |
1564 | goto out; | |
1565 | } | |
1566 | ||
1567 | /* change the rates */ | |
1568 | clk_change_rate(top); | |
1569 | ||
b2476490 | 1570 | out: |
eab89f69 | 1571 | clk_prepare_unlock(); |
b2476490 MT |
1572 | |
1573 | return ret; | |
1574 | } | |
1575 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
1576 | ||
1577 | /** | |
1578 | * clk_get_parent - return the parent of a clk | |
1579 | * @clk: the clk whose parent gets returned | |
1580 | * | |
1581 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
1582 | */ | |
1583 | struct clk *clk_get_parent(struct clk *clk) | |
1584 | { | |
1585 | struct clk *parent; | |
1586 | ||
eab89f69 | 1587 | clk_prepare_lock(); |
b2476490 | 1588 | parent = __clk_get_parent(clk); |
eab89f69 | 1589 | clk_prepare_unlock(); |
b2476490 MT |
1590 | |
1591 | return parent; | |
1592 | } | |
1593 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
1594 | ||
1595 | /* | |
1596 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
1597 | * optional for single-parent clocks. Always call .get_parent if it is | |
1598 | * available and WARN if it is missing for multi-parent clocks. | |
1599 | * | |
1600 | * For single-parent clocks without .get_parent, first check to see if the | |
1601 | * .parents array exists, and if so use it to avoid an expensive tree | |
1602 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
1603 | */ | |
1604 | static struct clk *__clk_init_parent(struct clk *clk) | |
1605 | { | |
1606 | struct clk *ret = NULL; | |
1607 | u8 index; | |
1608 | ||
1609 | /* handle the trivial cases */ | |
1610 | ||
1611 | if (!clk->num_parents) | |
1612 | goto out; | |
1613 | ||
1614 | if (clk->num_parents == 1) { | |
1615 | if (IS_ERR_OR_NULL(clk->parent)) | |
40ba3f0f | 1616 | clk->parent = __clk_lookup(clk->parent_names[0]); |
b2476490 MT |
1617 | ret = clk->parent; |
1618 | goto out; | |
1619 | } | |
1620 | ||
1621 | if (!clk->ops->get_parent) { | |
1622 | WARN(!clk->ops->get_parent, | |
1623 | "%s: multi-parent clocks must implement .get_parent\n", | |
1624 | __func__); | |
1625 | goto out; | |
1626 | }; | |
1627 | ||
1628 | /* | |
1629 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1630 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1631 | * clk->parent here; that is done by the calling function | |
1632 | */ | |
1633 | ||
1634 | index = clk->ops->get_parent(clk->hw); | |
1635 | ||
1636 | if (!clk->parents) | |
1637 | clk->parents = | |
96a7ed90 | 1638 | kcalloc(clk->num_parents, sizeof(struct clk *), |
b2476490 MT |
1639 | GFP_KERNEL); |
1640 | ||
7ef3dcc8 | 1641 | ret = clk_get_parent_by_index(clk, index); |
b2476490 MT |
1642 | |
1643 | out: | |
1644 | return ret; | |
1645 | } | |
1646 | ||
b33d212f UH |
1647 | void __clk_reparent(struct clk *clk, struct clk *new_parent) |
1648 | { | |
1649 | clk_reparent(clk, new_parent); | |
5279fc40 | 1650 | __clk_recalc_accuracies(clk); |
b2476490 MT |
1651 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
1652 | } | |
1653 | ||
b2476490 MT |
1654 | /** |
1655 | * clk_set_parent - switch the parent of a mux clk | |
1656 | * @clk: the mux clk whose input we are switching | |
1657 | * @parent: the new input to clk | |
1658 | * | |
f8aa0bd5 SK |
1659 | * Re-parent clk to use parent as its new input source. If clk is in |
1660 | * prepared state, the clk will get enabled for the duration of this call. If | |
1661 | * that's not acceptable for a specific clk (Eg: the consumer can't handle | |
1662 | * that, the reparenting is glitchy in hardware, etc), use the | |
1663 | * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. | |
1664 | * | |
1665 | * After successfully changing clk's parent clk_set_parent will update the | |
1666 | * clk topology, sysfs topology and propagate rate recalculation via | |
1667 | * __clk_recalc_rates. | |
1668 | * | |
1669 | * Returns 0 on success, -EERROR otherwise. | |
b2476490 MT |
1670 | */ |
1671 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
1672 | { | |
1673 | int ret = 0; | |
f1c8b2ed | 1674 | int p_index = 0; |
031dcc9b | 1675 | unsigned long p_rate = 0; |
b2476490 | 1676 | |
89ac8d7a MT |
1677 | if (!clk) |
1678 | return 0; | |
1679 | ||
031dcc9b UH |
1680 | /* verify ops for for multi-parent clks */ |
1681 | if ((clk->num_parents > 1) && (!clk->ops->set_parent)) | |
b2476490 MT |
1682 | return -ENOSYS; |
1683 | ||
1684 | /* prevent racing with updates to the clock topology */ | |
eab89f69 | 1685 | clk_prepare_lock(); |
b2476490 MT |
1686 | |
1687 | if (clk->parent == parent) | |
1688 | goto out; | |
1689 | ||
031dcc9b UH |
1690 | /* check that we are allowed to re-parent if the clock is in use */ |
1691 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1692 | ret = -EBUSY; | |
1693 | goto out; | |
1694 | } | |
1695 | ||
1696 | /* try finding the new parent index */ | |
1697 | if (parent) { | |
1698 | p_index = clk_fetch_parent_index(clk, parent); | |
1699 | p_rate = parent->rate; | |
f1c8b2ed | 1700 | if (p_index < 0) { |
031dcc9b UH |
1701 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1702 | __func__, parent->name, clk->name); | |
f1c8b2ed | 1703 | ret = p_index; |
031dcc9b UH |
1704 | goto out; |
1705 | } | |
1706 | } | |
1707 | ||
b2476490 | 1708 | /* propagate PRE_RATE_CHANGE notifications */ |
f3aab5d6 | 1709 | ret = __clk_speculate_rates(clk, p_rate); |
b2476490 MT |
1710 | |
1711 | /* abort if a driver objects */ | |
fb72a059 | 1712 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1713 | goto out; |
1714 | ||
031dcc9b UH |
1715 | /* do the re-parent */ |
1716 | ret = __clk_set_parent(clk, parent, p_index); | |
b2476490 | 1717 | |
5279fc40 BB |
1718 | /* propagate rate an accuracy recalculation accordingly */ |
1719 | if (ret) { | |
b2476490 | 1720 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); |
5279fc40 | 1721 | } else { |
a68de8e4 | 1722 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
5279fc40 BB |
1723 | __clk_recalc_accuracies(clk); |
1724 | } | |
b2476490 MT |
1725 | |
1726 | out: | |
eab89f69 | 1727 | clk_prepare_unlock(); |
b2476490 MT |
1728 | |
1729 | return ret; | |
1730 | } | |
1731 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1732 | ||
e59c5371 MT |
1733 | /** |
1734 | * clk_set_phase - adjust the phase shift of a clock signal | |
1735 | * @clk: clock signal source | |
1736 | * @degrees: number of degrees the signal is shifted | |
1737 | * | |
1738 | * Shifts the phase of a clock signal by the specified | |
1739 | * degrees. Returns 0 on success, -EERROR otherwise. | |
1740 | * | |
1741 | * This function makes no distinction about the input or reference | |
1742 | * signal that we adjust the clock signal phase against. For example | |
1743 | * phase locked-loop clock signal generators we may shift phase with | |
1744 | * respect to feedback clock signal input, but for other cases the | |
1745 | * clock phase may be shifted with respect to some other, unspecified | |
1746 | * signal. | |
1747 | * | |
1748 | * Additionally the concept of phase shift does not propagate through | |
1749 | * the clock tree hierarchy, which sets it apart from clock rates and | |
1750 | * clock accuracy. A parent clock phase attribute does not have an | |
1751 | * impact on the phase attribute of a child clock. | |
1752 | */ | |
1753 | int clk_set_phase(struct clk *clk, int degrees) | |
1754 | { | |
1755 | int ret = 0; | |
1756 | ||
1757 | if (!clk) | |
1758 | goto out; | |
1759 | ||
1760 | /* sanity check degrees */ | |
1761 | degrees %= 360; | |
1762 | if (degrees < 0) | |
1763 | degrees += 360; | |
1764 | ||
1765 | clk_prepare_lock(); | |
1766 | ||
1767 | if (!clk->ops->set_phase) | |
1768 | goto out_unlock; | |
1769 | ||
1770 | ret = clk->ops->set_phase(clk->hw, degrees); | |
1771 | ||
1772 | if (!ret) | |
1773 | clk->phase = degrees; | |
1774 | ||
1775 | out_unlock: | |
1776 | clk_prepare_unlock(); | |
1777 | ||
1778 | out: | |
1779 | return ret; | |
1780 | } | |
1781 | ||
1782 | /** | |
1783 | * clk_get_phase - return the phase shift of a clock signal | |
1784 | * @clk: clock signal source | |
1785 | * | |
1786 | * Returns the phase shift of a clock node in degrees, otherwise returns | |
1787 | * -EERROR. | |
1788 | */ | |
1789 | int clk_get_phase(struct clk *clk) | |
1790 | { | |
1791 | int ret = 0; | |
1792 | ||
1793 | if (!clk) | |
1794 | goto out; | |
1795 | ||
1796 | clk_prepare_lock(); | |
1797 | ret = clk->phase; | |
1798 | clk_prepare_unlock(); | |
1799 | ||
1800 | out: | |
1801 | return ret; | |
1802 | } | |
1803 | ||
b2476490 MT |
1804 | /** |
1805 | * __clk_init - initialize the data structures in a struct clk | |
1806 | * @dev: device initializing this clk, placeholder for now | |
1807 | * @clk: clk being initialized | |
1808 | * | |
1809 | * Initializes the lists in struct clk, queries the hardware for the | |
1810 | * parent and rate and sets them both. | |
b2476490 | 1811 | */ |
d1302a36 | 1812 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1813 | { |
d1302a36 | 1814 | int i, ret = 0; |
b2476490 | 1815 | struct clk *orphan; |
b67bfe0d | 1816 | struct hlist_node *tmp2; |
b2476490 MT |
1817 | |
1818 | if (!clk) | |
d1302a36 | 1819 | return -EINVAL; |
b2476490 | 1820 | |
eab89f69 | 1821 | clk_prepare_lock(); |
b2476490 MT |
1822 | |
1823 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1824 | if (__clk_lookup(clk->name)) { |
1825 | pr_debug("%s: clk %s already initialized\n", | |
1826 | __func__, clk->name); | |
1827 | ret = -EEXIST; | |
b2476490 | 1828 | goto out; |
d1302a36 | 1829 | } |
b2476490 | 1830 | |
d4d7e3dd MT |
1831 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1832 | if (clk->ops->set_rate && | |
71472c0c JH |
1833 | !((clk->ops->round_rate || clk->ops->determine_rate) && |
1834 | clk->ops->recalc_rate)) { | |
1835 | pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", | |
d4d7e3dd | 1836 | __func__, clk->name); |
d1302a36 | 1837 | ret = -EINVAL; |
d4d7e3dd MT |
1838 | goto out; |
1839 | } | |
1840 | ||
1841 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1842 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1843 | __func__, clk->name); | |
d1302a36 | 1844 | ret = -EINVAL; |
d4d7e3dd MT |
1845 | goto out; |
1846 | } | |
1847 | ||
3fa2252b SB |
1848 | if (clk->ops->set_rate_and_parent && |
1849 | !(clk->ops->set_parent && clk->ops->set_rate)) { | |
1850 | pr_warn("%s: %s must implement .set_parent & .set_rate\n", | |
1851 | __func__, clk->name); | |
1852 | ret = -EINVAL; | |
1853 | goto out; | |
1854 | } | |
1855 | ||
b2476490 MT |
1856 | /* throw a WARN if any entries in parent_names are NULL */ |
1857 | for (i = 0; i < clk->num_parents; i++) | |
1858 | WARN(!clk->parent_names[i], | |
1859 | "%s: invalid NULL in %s's .parent_names\n", | |
1860 | __func__, clk->name); | |
1861 | ||
1862 | /* | |
1863 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1864 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1865 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1866 | * must always check for a NULL pointer and try to populate it if | |
1867 | * necessary. | |
1868 | * | |
1869 | * If clk->parents is not NULL we skip this entire block. This allows | |
1870 | * for clock drivers to statically initialize clk->parents. | |
1871 | */ | |
9ca1c5a4 | 1872 | if (clk->num_parents > 1 && !clk->parents) { |
96a7ed90 TF |
1873 | clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *), |
1874 | GFP_KERNEL); | |
b2476490 MT |
1875 | /* |
1876 | * __clk_lookup returns NULL for parents that have not been | |
1877 | * clk_init'd; thus any access to clk->parents[] must check | |
1878 | * for a NULL pointer. We can always perform lazy lookups for | |
1879 | * missing parents later on. | |
1880 | */ | |
1881 | if (clk->parents) | |
1882 | for (i = 0; i < clk->num_parents; i++) | |
1883 | clk->parents[i] = | |
1884 | __clk_lookup(clk->parent_names[i]); | |
1885 | } | |
1886 | ||
1887 | clk->parent = __clk_init_parent(clk); | |
1888 | ||
1889 | /* | |
1890 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1891 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1892 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1893 | * clk list. | |
1894 | * | |
1895 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1896 | * clocks and re-parent any that are children of the clock currently | |
1897 | * being clk_init'd. | |
1898 | */ | |
1899 | if (clk->parent) | |
1900 | hlist_add_head(&clk->child_node, | |
1901 | &clk->parent->children); | |
1902 | else if (clk->flags & CLK_IS_ROOT) | |
1903 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1904 | else | |
1905 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1906 | ||
5279fc40 BB |
1907 | /* |
1908 | * Set clk's accuracy. The preferred method is to use | |
1909 | * .recalc_accuracy. For simple clocks and lazy developers the default | |
1910 | * fallback is to use the parent's accuracy. If a clock doesn't have a | |
1911 | * parent (or is orphaned) then accuracy is set to zero (perfect | |
1912 | * clock). | |
1913 | */ | |
1914 | if (clk->ops->recalc_accuracy) | |
1915 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1916 | __clk_get_accuracy(clk->parent)); | |
1917 | else if (clk->parent) | |
1918 | clk->accuracy = clk->parent->accuracy; | |
1919 | else | |
1920 | clk->accuracy = 0; | |
1921 | ||
9824cf73 MR |
1922 | /* |
1923 | * Set clk's phase. | |
1924 | * Since a phase is by definition relative to its parent, just | |
1925 | * query the current clock phase, or just assume it's in phase. | |
1926 | */ | |
1927 | if (clk->ops->get_phase) | |
1928 | clk->phase = clk->ops->get_phase(clk->hw); | |
1929 | else | |
1930 | clk->phase = 0; | |
1931 | ||
b2476490 MT |
1932 | /* |
1933 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1934 | * simple clocks and lazy developers the default fallback is to use the | |
1935 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1936 | * then rate is set to zero. | |
1937 | */ | |
1938 | if (clk->ops->recalc_rate) | |
1939 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1940 | __clk_get_rate(clk->parent)); | |
1941 | else if (clk->parent) | |
1942 | clk->rate = clk->parent->rate; | |
1943 | else | |
1944 | clk->rate = 0; | |
1945 | ||
1946 | /* | |
1947 | * walk the list of orphan clocks and reparent any that are children of | |
1948 | * this clock | |
1949 | */ | |
b67bfe0d | 1950 | hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { |
12d29886 | 1951 | if (orphan->num_parents && orphan->ops->get_parent) { |
1f61e5f1 MF |
1952 | i = orphan->ops->get_parent(orphan->hw); |
1953 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1954 | __clk_reparent(orphan, clk); | |
1955 | continue; | |
1956 | } | |
1957 | ||
b2476490 MT |
1958 | for (i = 0; i < orphan->num_parents; i++) |
1959 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1960 | __clk_reparent(orphan, clk); | |
1961 | break; | |
1962 | } | |
1f61e5f1 | 1963 | } |
b2476490 MT |
1964 | |
1965 | /* | |
1966 | * optional platform-specific magic | |
1967 | * | |
1968 | * The .init callback is not used by any of the basic clock types, but | |
1969 | * exists for weird hardware that must perform initialization magic. | |
1970 | * Please consider other ways of solving initialization problems before | |
24ee1a08 | 1971 | * using this callback, as its use is discouraged. |
b2476490 MT |
1972 | */ |
1973 | if (clk->ops->init) | |
1974 | clk->ops->init(clk->hw); | |
1975 | ||
fcb0ee6a | 1976 | kref_init(&clk->ref); |
b2476490 | 1977 | out: |
eab89f69 | 1978 | clk_prepare_unlock(); |
b2476490 | 1979 | |
89f7e9de SB |
1980 | if (!ret) |
1981 | clk_debug_register(clk); | |
1982 | ||
d1302a36 | 1983 | return ret; |
b2476490 MT |
1984 | } |
1985 | ||
0197b3ea SK |
1986 | /** |
1987 | * __clk_register - register a clock and return a cookie. | |
1988 | * | |
1989 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1990 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1991 | * of the struct clk need to be initialized. | |
1992 | * | |
1993 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1994 | * data. | |
1995 | * | |
1996 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1997 | * very large numbers of clocks that need to be statically initialized. It is | |
1998 | * a layering violation to include clk-private.h from any code which implements | |
1999 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
24ee1a08 | 2000 | * separate C file from the logic that implements its operations. Returns 0 |
0197b3ea SK |
2001 | * on success, otherwise an error code. |
2002 | */ | |
2003 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
2004 | { | |
2005 | int ret; | |
2006 | struct clk *clk; | |
2007 | ||
2008 | clk = hw->clk; | |
2009 | clk->name = hw->init->name; | |
2010 | clk->ops = hw->init->ops; | |
2011 | clk->hw = hw; | |
2012 | clk->flags = hw->init->flags; | |
2013 | clk->parent_names = hw->init->parent_names; | |
2014 | clk->num_parents = hw->init->num_parents; | |
ac2df527 SN |
2015 | if (dev && dev->driver) |
2016 | clk->owner = dev->driver->owner; | |
2017 | else | |
2018 | clk->owner = NULL; | |
0197b3ea SK |
2019 | |
2020 | ret = __clk_init(dev, clk); | |
2021 | if (ret) | |
2022 | return ERR_PTR(ret); | |
2023 | ||
2024 | return clk; | |
2025 | } | |
2026 | EXPORT_SYMBOL_GPL(__clk_register); | |
2027 | ||
293ba3b4 SB |
2028 | /** |
2029 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
2030 | * @dev: device that is registering this clock | |
2031 | * @hw: link to hardware-specific clock data | |
2032 | * | |
2033 | * clk_register is the primary interface for populating the clock tree with new | |
2034 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
2035 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
2036 | * rest of the clock API. In the event of an error clk_register will return an | |
2037 | * error code; drivers must test for an error code after calling clk_register. | |
2038 | */ | |
2039 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
b2476490 | 2040 | { |
d1302a36 | 2041 | int i, ret; |
293ba3b4 SB |
2042 | struct clk *clk; |
2043 | ||
2044 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
2045 | if (!clk) { | |
2046 | pr_err("%s: could not allocate clk\n", __func__); | |
2047 | ret = -ENOMEM; | |
2048 | goto fail_out; | |
2049 | } | |
b2476490 | 2050 | |
612936f2 | 2051 | clk->name = kstrdup_const(hw->init->name, GFP_KERNEL); |
0197b3ea SK |
2052 | if (!clk->name) { |
2053 | pr_err("%s: could not allocate clk->name\n", __func__); | |
2054 | ret = -ENOMEM; | |
2055 | goto fail_name; | |
2056 | } | |
2057 | clk->ops = hw->init->ops; | |
ac2df527 SN |
2058 | if (dev && dev->driver) |
2059 | clk->owner = dev->driver->owner; | |
b2476490 | 2060 | clk->hw = hw; |
0197b3ea SK |
2061 | clk->flags = hw->init->flags; |
2062 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
2063 | hw->clk = clk; |
2064 | ||
d1302a36 | 2065 | /* allocate local copy in case parent_names is __initdata */ |
96a7ed90 TF |
2066 | clk->parent_names = kcalloc(clk->num_parents, sizeof(char *), |
2067 | GFP_KERNEL); | |
d1302a36 MT |
2068 | |
2069 | if (!clk->parent_names) { | |
2070 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
2071 | ret = -ENOMEM; | |
2072 | goto fail_parent_names; | |
2073 | } | |
2074 | ||
2075 | ||
2076 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea | 2077 | for (i = 0; i < clk->num_parents; i++) { |
612936f2 | 2078 | clk->parent_names[i] = kstrdup_const(hw->init->parent_names[i], |
0197b3ea | 2079 | GFP_KERNEL); |
d1302a36 MT |
2080 | if (!clk->parent_names[i]) { |
2081 | pr_err("%s: could not copy parent_names\n", __func__); | |
2082 | ret = -ENOMEM; | |
2083 | goto fail_parent_names_copy; | |
2084 | } | |
2085 | } | |
2086 | ||
2087 | ret = __clk_init(dev, clk); | |
2088 | if (!ret) | |
293ba3b4 | 2089 | return clk; |
b2476490 | 2090 | |
d1302a36 MT |
2091 | fail_parent_names_copy: |
2092 | while (--i >= 0) | |
612936f2 | 2093 | kfree_const(clk->parent_names[i]); |
d1302a36 MT |
2094 | kfree(clk->parent_names); |
2095 | fail_parent_names: | |
612936f2 | 2096 | kfree_const(clk->name); |
0197b3ea | 2097 | fail_name: |
d1302a36 MT |
2098 | kfree(clk); |
2099 | fail_out: | |
2100 | return ERR_PTR(ret); | |
b2476490 MT |
2101 | } |
2102 | EXPORT_SYMBOL_GPL(clk_register); | |
2103 | ||
fcb0ee6a SN |
2104 | /* |
2105 | * Free memory allocated for a clock. | |
2106 | * Caller must hold prepare_lock. | |
2107 | */ | |
2108 | static void __clk_release(struct kref *ref) | |
2109 | { | |
2110 | struct clk *clk = container_of(ref, struct clk, ref); | |
2111 | int i = clk->num_parents; | |
2112 | ||
2113 | kfree(clk->parents); | |
2114 | while (--i >= 0) | |
612936f2 | 2115 | kfree_const(clk->parent_names[i]); |
fcb0ee6a SN |
2116 | |
2117 | kfree(clk->parent_names); | |
612936f2 | 2118 | kfree_const(clk->name); |
fcb0ee6a SN |
2119 | kfree(clk); |
2120 | } | |
2121 | ||
2122 | /* | |
2123 | * Empty clk_ops for unregistered clocks. These are used temporarily | |
2124 | * after clk_unregister() was called on a clock and until last clock | |
2125 | * consumer calls clk_put() and the struct clk object is freed. | |
2126 | */ | |
2127 | static int clk_nodrv_prepare_enable(struct clk_hw *hw) | |
2128 | { | |
2129 | return -ENXIO; | |
2130 | } | |
2131 | ||
2132 | static void clk_nodrv_disable_unprepare(struct clk_hw *hw) | |
2133 | { | |
2134 | WARN_ON_ONCE(1); | |
2135 | } | |
2136 | ||
2137 | static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, | |
2138 | unsigned long parent_rate) | |
2139 | { | |
2140 | return -ENXIO; | |
2141 | } | |
2142 | ||
2143 | static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) | |
2144 | { | |
2145 | return -ENXIO; | |
2146 | } | |
2147 | ||
2148 | static const struct clk_ops clk_nodrv_ops = { | |
2149 | .enable = clk_nodrv_prepare_enable, | |
2150 | .disable = clk_nodrv_disable_unprepare, | |
2151 | .prepare = clk_nodrv_prepare_enable, | |
2152 | .unprepare = clk_nodrv_disable_unprepare, | |
2153 | .set_rate = clk_nodrv_set_rate, | |
2154 | .set_parent = clk_nodrv_set_parent, | |
2155 | }; | |
2156 | ||
1df5c939 MB |
2157 | /** |
2158 | * clk_unregister - unregister a currently registered clock | |
2159 | * @clk: clock to unregister | |
1df5c939 | 2160 | */ |
fcb0ee6a SN |
2161 | void clk_unregister(struct clk *clk) |
2162 | { | |
2163 | unsigned long flags; | |
2164 | ||
6314b679 SB |
2165 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) |
2166 | return; | |
2167 | ||
2168 | clk_debug_unregister(clk); | |
fcb0ee6a SN |
2169 | |
2170 | clk_prepare_lock(); | |
2171 | ||
2172 | if (clk->ops == &clk_nodrv_ops) { | |
2173 | pr_err("%s: unregistered clock: %s\n", __func__, clk->name); | |
6314b679 | 2174 | return; |
fcb0ee6a SN |
2175 | } |
2176 | /* | |
2177 | * Assign empty clock ops for consumers that might still hold | |
2178 | * a reference to this clock. | |
2179 | */ | |
2180 | flags = clk_enable_lock(); | |
2181 | clk->ops = &clk_nodrv_ops; | |
2182 | clk_enable_unlock(flags); | |
2183 | ||
2184 | if (!hlist_empty(&clk->children)) { | |
2185 | struct clk *child; | |
874f224c | 2186 | struct hlist_node *t; |
fcb0ee6a SN |
2187 | |
2188 | /* Reparent all children to the orphan list. */ | |
874f224c | 2189 | hlist_for_each_entry_safe(child, t, &clk->children, child_node) |
fcb0ee6a SN |
2190 | clk_set_parent(child, NULL); |
2191 | } | |
2192 | ||
fcb0ee6a SN |
2193 | hlist_del_init(&clk->child_node); |
2194 | ||
2195 | if (clk->prepare_count) | |
2196 | pr_warn("%s: unregistering prepared clock: %s\n", | |
2197 | __func__, clk->name); | |
fcb0ee6a | 2198 | kref_put(&clk->ref, __clk_release); |
6314b679 | 2199 | |
fcb0ee6a SN |
2200 | clk_prepare_unlock(); |
2201 | } | |
1df5c939 MB |
2202 | EXPORT_SYMBOL_GPL(clk_unregister); |
2203 | ||
46c8773a SB |
2204 | static void devm_clk_release(struct device *dev, void *res) |
2205 | { | |
293ba3b4 | 2206 | clk_unregister(*(struct clk **)res); |
46c8773a SB |
2207 | } |
2208 | ||
2209 | /** | |
2210 | * devm_clk_register - resource managed clk_register() | |
2211 | * @dev: device that is registering this clock | |
2212 | * @hw: link to hardware-specific clock data | |
2213 | * | |
2214 | * Managed clk_register(). Clocks returned from this function are | |
2215 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
2216 | * more information. | |
2217 | */ | |
2218 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
2219 | { | |
2220 | struct clk *clk; | |
293ba3b4 | 2221 | struct clk **clkp; |
46c8773a | 2222 | |
293ba3b4 SB |
2223 | clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL); |
2224 | if (!clkp) | |
46c8773a SB |
2225 | return ERR_PTR(-ENOMEM); |
2226 | ||
293ba3b4 SB |
2227 | clk = clk_register(dev, hw); |
2228 | if (!IS_ERR(clk)) { | |
2229 | *clkp = clk; | |
2230 | devres_add(dev, clkp); | |
46c8773a | 2231 | } else { |
293ba3b4 | 2232 | devres_free(clkp); |
46c8773a SB |
2233 | } |
2234 | ||
2235 | return clk; | |
2236 | } | |
2237 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
2238 | ||
2239 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
2240 | { | |
2241 | struct clk *c = res; | |
2242 | if (WARN_ON(!c)) | |
2243 | return 0; | |
2244 | return c == data; | |
2245 | } | |
2246 | ||
2247 | /** | |
2248 | * devm_clk_unregister - resource managed clk_unregister() | |
2249 | * @clk: clock to unregister | |
2250 | * | |
2251 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
2252 | * this function will not need to be called and the resource management | |
2253 | * code will ensure that the resource is freed. | |
2254 | */ | |
2255 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
2256 | { | |
2257 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
2258 | } | |
2259 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
2260 | ||
ac2df527 SN |
2261 | /* |
2262 | * clkdev helpers | |
2263 | */ | |
2264 | int __clk_get(struct clk *clk) | |
2265 | { | |
00efcb1c SN |
2266 | if (clk) { |
2267 | if (!try_module_get(clk->owner)) | |
2268 | return 0; | |
ac2df527 | 2269 | |
00efcb1c SN |
2270 | kref_get(&clk->ref); |
2271 | } | |
ac2df527 SN |
2272 | return 1; |
2273 | } | |
2274 | ||
2275 | void __clk_put(struct clk *clk) | |
2276 | { | |
10cdfe54 TV |
2277 | struct module *owner; |
2278 | ||
00efcb1c | 2279 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) |
ac2df527 SN |
2280 | return; |
2281 | ||
fcb0ee6a | 2282 | clk_prepare_lock(); |
10cdfe54 | 2283 | owner = clk->owner; |
fcb0ee6a SN |
2284 | kref_put(&clk->ref, __clk_release); |
2285 | clk_prepare_unlock(); | |
2286 | ||
10cdfe54 | 2287 | module_put(owner); |
ac2df527 SN |
2288 | } |
2289 | ||
b2476490 MT |
2290 | /*** clk rate change notifiers ***/ |
2291 | ||
2292 | /** | |
2293 | * clk_notifier_register - add a clk rate change notifier | |
2294 | * @clk: struct clk * to watch | |
2295 | * @nb: struct notifier_block * with callback info | |
2296 | * | |
2297 | * Request notification when clk's rate changes. This uses an SRCU | |
2298 | * notifier because we want it to block and notifier unregistrations are | |
2299 | * uncommon. The callbacks associated with the notifier must not | |
2300 | * re-enter into the clk framework by calling any top-level clk APIs; | |
2301 | * this will cause a nested prepare_lock mutex. | |
2302 | * | |
5324fda7 SB |
2303 | * In all notification cases cases (pre, post and abort rate change) the |
2304 | * original clock rate is passed to the callback via struct | |
2305 | * clk_notifier_data.old_rate and the new frequency is passed via struct | |
b2476490 MT |
2306 | * clk_notifier_data.new_rate. |
2307 | * | |
b2476490 MT |
2308 | * clk_notifier_register() must be called from non-atomic context. |
2309 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
2310 | * allocation failure; otherwise, passes along the return value of | |
2311 | * srcu_notifier_chain_register(). | |
2312 | */ | |
2313 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
2314 | { | |
2315 | struct clk_notifier *cn; | |
2316 | int ret = -ENOMEM; | |
2317 | ||
2318 | if (!clk || !nb) | |
2319 | return -EINVAL; | |
2320 | ||
eab89f69 | 2321 | clk_prepare_lock(); |
b2476490 MT |
2322 | |
2323 | /* search the list of notifiers for this clk */ | |
2324 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2325 | if (cn->clk == clk) | |
2326 | break; | |
2327 | ||
2328 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
2329 | if (cn->clk != clk) { | |
2330 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
2331 | if (!cn) | |
2332 | goto out; | |
2333 | ||
2334 | cn->clk = clk; | |
2335 | srcu_init_notifier_head(&cn->notifier_head); | |
2336 | ||
2337 | list_add(&cn->node, &clk_notifier_list); | |
2338 | } | |
2339 | ||
2340 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
2341 | ||
2342 | clk->notifier_count++; | |
2343 | ||
2344 | out: | |
eab89f69 | 2345 | clk_prepare_unlock(); |
b2476490 MT |
2346 | |
2347 | return ret; | |
2348 | } | |
2349 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
2350 | ||
2351 | /** | |
2352 | * clk_notifier_unregister - remove a clk rate change notifier | |
2353 | * @clk: struct clk * | |
2354 | * @nb: struct notifier_block * with callback info | |
2355 | * | |
2356 | * Request no further notification for changes to 'clk' and frees memory | |
2357 | * allocated in clk_notifier_register. | |
2358 | * | |
2359 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
2360 | * along the return value of srcu_notifier_chain_unregister(). | |
2361 | */ | |
2362 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
2363 | { | |
2364 | struct clk_notifier *cn = NULL; | |
2365 | int ret = -EINVAL; | |
2366 | ||
2367 | if (!clk || !nb) | |
2368 | return -EINVAL; | |
2369 | ||
eab89f69 | 2370 | clk_prepare_lock(); |
b2476490 MT |
2371 | |
2372 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2373 | if (cn->clk == clk) | |
2374 | break; | |
2375 | ||
2376 | if (cn->clk == clk) { | |
2377 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
2378 | ||
2379 | clk->notifier_count--; | |
2380 | ||
2381 | /* XXX the notifier code should handle this better */ | |
2382 | if (!cn->notifier_head.head) { | |
2383 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
72b5322f | 2384 | list_del(&cn->node); |
b2476490 MT |
2385 | kfree(cn); |
2386 | } | |
2387 | ||
2388 | } else { | |
2389 | ret = -ENOENT; | |
2390 | } | |
2391 | ||
eab89f69 | 2392 | clk_prepare_unlock(); |
b2476490 MT |
2393 | |
2394 | return ret; | |
2395 | } | |
2396 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
2397 | |
2398 | #ifdef CONFIG_OF | |
2399 | /** | |
2400 | * struct of_clk_provider - Clock provider registration structure | |
2401 | * @link: Entry in global list of clock providers | |
2402 | * @node: Pointer to device tree node of clock provider | |
2403 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
2404 | * given clock specifier | |
2405 | * @data: context pointer to be passed into @get callback | |
2406 | */ | |
2407 | struct of_clk_provider { | |
2408 | struct list_head link; | |
2409 | ||
2410 | struct device_node *node; | |
2411 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
2412 | void *data; | |
2413 | }; | |
2414 | ||
f2f6c255 PG |
2415 | static const struct of_device_id __clk_of_table_sentinel |
2416 | __used __section(__clk_of_table_end); | |
2417 | ||
766e6a4e | 2418 | static LIST_HEAD(of_clk_providers); |
d6782c26 SN |
2419 | static DEFINE_MUTEX(of_clk_mutex); |
2420 | ||
2421 | /* of_clk_provider list locking helpers */ | |
2422 | void of_clk_lock(void) | |
2423 | { | |
2424 | mutex_lock(&of_clk_mutex); | |
2425 | } | |
2426 | ||
2427 | void of_clk_unlock(void) | |
2428 | { | |
2429 | mutex_unlock(&of_clk_mutex); | |
2430 | } | |
766e6a4e GL |
2431 | |
2432 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
2433 | void *data) | |
2434 | { | |
2435 | return data; | |
2436 | } | |
2437 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
2438 | ||
494bfec9 SG |
2439 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
2440 | { | |
2441 | struct clk_onecell_data *clk_data = data; | |
2442 | unsigned int idx = clkspec->args[0]; | |
2443 | ||
2444 | if (idx >= clk_data->clk_num) { | |
2445 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
2446 | return ERR_PTR(-EINVAL); | |
2447 | } | |
2448 | ||
2449 | return clk_data->clks[idx]; | |
2450 | } | |
2451 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
2452 | ||
766e6a4e GL |
2453 | /** |
2454 | * of_clk_add_provider() - Register a clock provider for a node | |
2455 | * @np: Device node pointer associated with clock provider | |
2456 | * @clk_src_get: callback for decoding clock | |
2457 | * @data: context pointer for @clk_src_get callback. | |
2458 | */ | |
2459 | int of_clk_add_provider(struct device_node *np, | |
2460 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
2461 | void *data), | |
2462 | void *data) | |
2463 | { | |
2464 | struct of_clk_provider *cp; | |
86be408b | 2465 | int ret; |
766e6a4e GL |
2466 | |
2467 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
2468 | if (!cp) | |
2469 | return -ENOMEM; | |
2470 | ||
2471 | cp->node = of_node_get(np); | |
2472 | cp->data = data; | |
2473 | cp->get = clk_src_get; | |
2474 | ||
d6782c26 | 2475 | mutex_lock(&of_clk_mutex); |
766e6a4e | 2476 | list_add(&cp->link, &of_clk_providers); |
d6782c26 | 2477 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2478 | pr_debug("Added clock from %s\n", np->full_name); |
2479 | ||
86be408b SN |
2480 | ret = of_clk_set_defaults(np, true); |
2481 | if (ret < 0) | |
2482 | of_clk_del_provider(np); | |
2483 | ||
2484 | return ret; | |
766e6a4e GL |
2485 | } |
2486 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
2487 | ||
2488 | /** | |
2489 | * of_clk_del_provider() - Remove a previously registered clock provider | |
2490 | * @np: Device node pointer associated with clock provider | |
2491 | */ | |
2492 | void of_clk_del_provider(struct device_node *np) | |
2493 | { | |
2494 | struct of_clk_provider *cp; | |
2495 | ||
d6782c26 | 2496 | mutex_lock(&of_clk_mutex); |
766e6a4e GL |
2497 | list_for_each_entry(cp, &of_clk_providers, link) { |
2498 | if (cp->node == np) { | |
2499 | list_del(&cp->link); | |
2500 | of_node_put(cp->node); | |
2501 | kfree(cp); | |
2502 | break; | |
2503 | } | |
2504 | } | |
d6782c26 | 2505 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2506 | } |
2507 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
2508 | ||
d6782c26 | 2509 | struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) |
766e6a4e GL |
2510 | { |
2511 | struct of_clk_provider *provider; | |
a34cd466 | 2512 | struct clk *clk = ERR_PTR(-EPROBE_DEFER); |
766e6a4e GL |
2513 | |
2514 | /* Check if we have such a provider in our array */ | |
766e6a4e GL |
2515 | list_for_each_entry(provider, &of_clk_providers, link) { |
2516 | if (provider->node == clkspec->np) | |
2517 | clk = provider->get(clkspec, provider->data); | |
2518 | if (!IS_ERR(clk)) | |
2519 | break; | |
2520 | } | |
d6782c26 SN |
2521 | |
2522 | return clk; | |
2523 | } | |
2524 | ||
2525 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
2526 | { | |
2527 | struct clk *clk; | |
2528 | ||
2529 | mutex_lock(&of_clk_mutex); | |
2530 | clk = __of_clk_get_from_provider(clkspec); | |
2531 | mutex_unlock(&of_clk_mutex); | |
766e6a4e GL |
2532 | |
2533 | return clk; | |
2534 | } | |
2535 | ||
f6102742 MT |
2536 | int of_clk_get_parent_count(struct device_node *np) |
2537 | { | |
2538 | return of_count_phandle_with_args(np, "clocks", "#clock-cells"); | |
2539 | } | |
2540 | EXPORT_SYMBOL_GPL(of_clk_get_parent_count); | |
2541 | ||
766e6a4e GL |
2542 | const char *of_clk_get_parent_name(struct device_node *np, int index) |
2543 | { | |
2544 | struct of_phandle_args clkspec; | |
7a0fc1a3 | 2545 | struct property *prop; |
766e6a4e | 2546 | const char *clk_name; |
7a0fc1a3 BD |
2547 | const __be32 *vp; |
2548 | u32 pv; | |
766e6a4e | 2549 | int rc; |
7a0fc1a3 | 2550 | int count; |
766e6a4e GL |
2551 | |
2552 | if (index < 0) | |
2553 | return NULL; | |
2554 | ||
2555 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
2556 | &clkspec); | |
2557 | if (rc) | |
2558 | return NULL; | |
2559 | ||
7a0fc1a3 BD |
2560 | index = clkspec.args_count ? clkspec.args[0] : 0; |
2561 | count = 0; | |
2562 | ||
2563 | /* if there is an indices property, use it to transfer the index | |
2564 | * specified into an array offset for the clock-output-names property. | |
2565 | */ | |
2566 | of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) { | |
2567 | if (index == pv) { | |
2568 | index = count; | |
2569 | break; | |
2570 | } | |
2571 | count++; | |
2572 | } | |
2573 | ||
766e6a4e | 2574 | if (of_property_read_string_index(clkspec.np, "clock-output-names", |
7a0fc1a3 | 2575 | index, |
766e6a4e GL |
2576 | &clk_name) < 0) |
2577 | clk_name = clkspec.np->name; | |
2578 | ||
2579 | of_node_put(clkspec.np); | |
2580 | return clk_name; | |
2581 | } | |
2582 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
2583 | ||
1771b10d GC |
2584 | struct clock_provider { |
2585 | of_clk_init_cb_t clk_init_cb; | |
2586 | struct device_node *np; | |
2587 | struct list_head node; | |
2588 | }; | |
2589 | ||
2590 | static LIST_HEAD(clk_provider_list); | |
2591 | ||
2592 | /* | |
2593 | * This function looks for a parent clock. If there is one, then it | |
2594 | * checks that the provider for this parent clock was initialized, in | |
2595 | * this case the parent clock will be ready. | |
2596 | */ | |
2597 | static int parent_ready(struct device_node *np) | |
2598 | { | |
2599 | int i = 0; | |
2600 | ||
2601 | while (true) { | |
2602 | struct clk *clk = of_clk_get(np, i); | |
2603 | ||
2604 | /* this parent is ready we can check the next one */ | |
2605 | if (!IS_ERR(clk)) { | |
2606 | clk_put(clk); | |
2607 | i++; | |
2608 | continue; | |
2609 | } | |
2610 | ||
2611 | /* at least one parent is not ready, we exit now */ | |
2612 | if (PTR_ERR(clk) == -EPROBE_DEFER) | |
2613 | return 0; | |
2614 | ||
2615 | /* | |
2616 | * Here we make assumption that the device tree is | |
2617 | * written correctly. So an error means that there is | |
2618 | * no more parent. As we didn't exit yet, then the | |
2619 | * previous parent are ready. If there is no clock | |
2620 | * parent, no need to wait for them, then we can | |
2621 | * consider their absence as being ready | |
2622 | */ | |
2623 | return 1; | |
2624 | } | |
2625 | } | |
2626 | ||
766e6a4e GL |
2627 | /** |
2628 | * of_clk_init() - Scan and init clock providers from the DT | |
2629 | * @matches: array of compatible values and init functions for providers. | |
2630 | * | |
1771b10d | 2631 | * This function scans the device tree for matching clock providers |
e5ca8fb4 | 2632 | * and calls their initialization functions. It also does it by trying |
1771b10d | 2633 | * to follow the dependencies. |
766e6a4e GL |
2634 | */ |
2635 | void __init of_clk_init(const struct of_device_id *matches) | |
2636 | { | |
7f7ed584 | 2637 | const struct of_device_id *match; |
766e6a4e | 2638 | struct device_node *np; |
1771b10d GC |
2639 | struct clock_provider *clk_provider, *next; |
2640 | bool is_init_done; | |
2641 | bool force = false; | |
766e6a4e | 2642 | |
f2f6c255 | 2643 | if (!matches) |
819b4861 | 2644 | matches = &__clk_of_table; |
f2f6c255 | 2645 | |
1771b10d | 2646 | /* First prepare the list of the clocks providers */ |
7f7ed584 | 2647 | for_each_matching_node_and_match(np, matches, &match) { |
1771b10d GC |
2648 | struct clock_provider *parent = |
2649 | kzalloc(sizeof(struct clock_provider), GFP_KERNEL); | |
2650 | ||
2651 | parent->clk_init_cb = match->data; | |
2652 | parent->np = np; | |
3f6d439f | 2653 | list_add_tail(&parent->node, &clk_provider_list); |
1771b10d GC |
2654 | } |
2655 | ||
2656 | while (!list_empty(&clk_provider_list)) { | |
2657 | is_init_done = false; | |
2658 | list_for_each_entry_safe(clk_provider, next, | |
2659 | &clk_provider_list, node) { | |
2660 | if (force || parent_ready(clk_provider->np)) { | |
86be408b | 2661 | |
1771b10d | 2662 | clk_provider->clk_init_cb(clk_provider->np); |
86be408b SN |
2663 | of_clk_set_defaults(clk_provider->np, true); |
2664 | ||
1771b10d GC |
2665 | list_del(&clk_provider->node); |
2666 | kfree(clk_provider); | |
2667 | is_init_done = true; | |
2668 | } | |
2669 | } | |
2670 | ||
2671 | /* | |
e5ca8fb4 | 2672 | * We didn't manage to initialize any of the |
1771b10d GC |
2673 | * remaining providers during the last loop, so now we |
2674 | * initialize all the remaining ones unconditionally | |
2675 | * in case the clock parent was not mandatory | |
2676 | */ | |
2677 | if (!is_init_done) | |
2678 | force = true; | |
766e6a4e GL |
2679 | } |
2680 | } | |
2681 | #endif |