Commit | Line | Data |
---|---|---|
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 | /* caller must hold prepare_lock */ |
244 | static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) | |
245 | { | |
246 | struct dentry *d; | |
247 | int ret = -ENOMEM; | |
248 | ||
249 | if (!clk || !pdentry) { | |
250 | ret = -EINVAL; | |
251 | goto out; | |
252 | } | |
253 | ||
254 | d = debugfs_create_dir(clk->name, pdentry); | |
255 | if (!d) | |
256 | goto out; | |
257 | ||
258 | clk->dentry = d; | |
259 | ||
260 | d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, | |
261 | (u32 *)&clk->rate); | |
262 | if (!d) | |
263 | goto err_out; | |
264 | ||
5279fc40 BB |
265 | d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry, |
266 | (u32 *)&clk->accuracy); | |
267 | if (!d) | |
268 | goto err_out; | |
269 | ||
e59c5371 MT |
270 | d = debugfs_create_u32("clk_phase", S_IRUGO, clk->dentry, |
271 | (u32 *)&clk->phase); | |
272 | if (!d) | |
273 | goto err_out; | |
274 | ||
b2476490 MT |
275 | d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, |
276 | (u32 *)&clk->flags); | |
277 | if (!d) | |
278 | goto err_out; | |
279 | ||
280 | d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, | |
281 | (u32 *)&clk->prepare_count); | |
282 | if (!d) | |
283 | goto err_out; | |
284 | ||
285 | d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, | |
286 | (u32 *)&clk->enable_count); | |
287 | if (!d) | |
288 | goto err_out; | |
289 | ||
290 | d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, | |
291 | (u32 *)&clk->notifier_count); | |
292 | if (!d) | |
293 | goto err_out; | |
294 | ||
abeab450 CB |
295 | if (clk->ops->debug_init) { |
296 | ret = clk->ops->debug_init(clk->hw, clk->dentry); | |
297 | if (ret) | |
c646cbf1 | 298 | goto err_out; |
abeab450 | 299 | } |
c646cbf1 | 300 | |
b2476490 MT |
301 | ret = 0; |
302 | goto out; | |
303 | ||
304 | err_out: | |
b5f98e65 AE |
305 | debugfs_remove_recursive(clk->dentry); |
306 | clk->dentry = NULL; | |
b2476490 MT |
307 | out: |
308 | return ret; | |
309 | } | |
310 | ||
b2476490 MT |
311 | /** |
312 | * clk_debug_register - add a clk node to the debugfs clk tree | |
313 | * @clk: the clk being added to the debugfs clk tree | |
314 | * | |
315 | * Dynamically adds a clk to the debugfs clk tree if debugfs has been | |
316 | * initialized. Otherwise it bails out early since the debugfs clk tree | |
317 | * will be created lazily by clk_debug_init as part of a late_initcall. | |
b2476490 MT |
318 | */ |
319 | static int clk_debug_register(struct clk *clk) | |
320 | { | |
b2476490 MT |
321 | int ret = 0; |
322 | ||
6314b679 SB |
323 | mutex_lock(&clk_debug_lock); |
324 | hlist_add_head(&clk->debug_node, &clk_debug_list); | |
325 | ||
b2476490 | 326 | if (!inited) |
6314b679 | 327 | goto unlock; |
b2476490 | 328 | |
6314b679 SB |
329 | ret = clk_debug_create_one(clk, rootdir); |
330 | unlock: | |
331 | mutex_unlock(&clk_debug_lock); | |
b2476490 | 332 | |
b2476490 MT |
333 | return ret; |
334 | } | |
335 | ||
fcb0ee6a SN |
336 | /** |
337 | * clk_debug_unregister - remove a clk node from the debugfs clk tree | |
338 | * @clk: the clk being removed from the debugfs clk tree | |
339 | * | |
340 | * Dynamically removes a clk and all it's children clk nodes from the | |
341 | * debugfs clk tree if clk->dentry points to debugfs created by | |
342 | * clk_debug_register in __clk_init. | |
fcb0ee6a SN |
343 | */ |
344 | static void clk_debug_unregister(struct clk *clk) | |
345 | { | |
6314b679 SB |
346 | mutex_lock(&clk_debug_lock); |
347 | if (!clk->dentry) | |
348 | goto out; | |
349 | ||
350 | hlist_del_init(&clk->debug_node); | |
fcb0ee6a | 351 | debugfs_remove_recursive(clk->dentry); |
6314b679 SB |
352 | clk->dentry = NULL; |
353 | out: | |
354 | mutex_unlock(&clk_debug_lock); | |
fcb0ee6a SN |
355 | } |
356 | ||
fb2b3c9f PDS |
357 | struct dentry *clk_debugfs_add_file(struct clk *clk, char *name, umode_t mode, |
358 | void *data, const struct file_operations *fops) | |
359 | { | |
360 | struct dentry *d = NULL; | |
361 | ||
362 | if (clk->dentry) | |
363 | d = debugfs_create_file(name, mode, clk->dentry, data, fops); | |
364 | ||
365 | return d; | |
366 | } | |
367 | EXPORT_SYMBOL_GPL(clk_debugfs_add_file); | |
368 | ||
b2476490 MT |
369 | /** |
370 | * clk_debug_init - lazily create the debugfs clk tree visualization | |
371 | * | |
372 | * clks are often initialized very early during boot before memory can | |
373 | * be dynamically allocated and well before debugfs is setup. | |
374 | * clk_debug_init walks the clk tree hierarchy while holding | |
375 | * prepare_lock and creates the topology as part of a late_initcall, | |
376 | * thus insuring that clks initialized very early will still be | |
377 | * represented in the debugfs clk tree. This function should only be | |
378 | * called once at boot-time, and all other clks added dynamically will | |
379 | * be done so with clk_debug_register. | |
380 | */ | |
381 | static int __init clk_debug_init(void) | |
382 | { | |
383 | struct clk *clk; | |
1af599df | 384 | struct dentry *d; |
b2476490 MT |
385 | |
386 | rootdir = debugfs_create_dir("clk", NULL); | |
387 | ||
388 | if (!rootdir) | |
389 | return -ENOMEM; | |
390 | ||
27b8d5f7 | 391 | d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists, |
1af599df PG |
392 | &clk_summary_fops); |
393 | if (!d) | |
394 | return -ENOMEM; | |
395 | ||
27b8d5f7 | 396 | d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists, |
bddca894 PG |
397 | &clk_dump_fops); |
398 | if (!d) | |
399 | return -ENOMEM; | |
400 | ||
27b8d5f7 PDS |
401 | d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir, |
402 | &orphan_list, &clk_summary_fops); | |
403 | if (!d) | |
404 | return -ENOMEM; | |
b2476490 | 405 | |
27b8d5f7 PDS |
406 | d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir, |
407 | &orphan_list, &clk_dump_fops); | |
408 | if (!d) | |
b2476490 MT |
409 | return -ENOMEM; |
410 | ||
6314b679 SB |
411 | mutex_lock(&clk_debug_lock); |
412 | hlist_for_each_entry(clk, &clk_debug_list, debug_node) | |
413 | clk_debug_create_one(clk, rootdir); | |
b2476490 MT |
414 | |
415 | inited = 1; | |
6314b679 | 416 | mutex_unlock(&clk_debug_lock); |
b2476490 MT |
417 | |
418 | return 0; | |
419 | } | |
420 | late_initcall(clk_debug_init); | |
421 | #else | |
422 | static inline int clk_debug_register(struct clk *clk) { return 0; } | |
b33d212f UH |
423 | static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent) |
424 | { | |
425 | } | |
fcb0ee6a SN |
426 | static inline void clk_debug_unregister(struct clk *clk) |
427 | { | |
428 | } | |
70d347e6 | 429 | #endif |
b2476490 | 430 | |
1c155b3d UH |
431 | /* caller must hold prepare_lock */ |
432 | static void clk_unprepare_unused_subtree(struct clk *clk) | |
433 | { | |
434 | struct clk *child; | |
435 | ||
436 | if (!clk) | |
437 | return; | |
438 | ||
439 | hlist_for_each_entry(child, &clk->children, child_node) | |
440 | clk_unprepare_unused_subtree(child); | |
441 | ||
442 | if (clk->prepare_count) | |
443 | return; | |
444 | ||
445 | if (clk->flags & CLK_IGNORE_UNUSED) | |
446 | return; | |
447 | ||
3cc8247f UH |
448 | if (__clk_is_prepared(clk)) { |
449 | if (clk->ops->unprepare_unused) | |
450 | clk->ops->unprepare_unused(clk->hw); | |
451 | else if (clk->ops->unprepare) | |
1c155b3d | 452 | clk->ops->unprepare(clk->hw); |
3cc8247f | 453 | } |
1c155b3d UH |
454 | } |
455 | ||
b2476490 MT |
456 | /* caller must hold prepare_lock */ |
457 | static void clk_disable_unused_subtree(struct clk *clk) | |
458 | { | |
459 | struct clk *child; | |
b2476490 MT |
460 | unsigned long flags; |
461 | ||
462 | if (!clk) | |
463 | goto out; | |
464 | ||
b67bfe0d | 465 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
466 | clk_disable_unused_subtree(child); |
467 | ||
eab89f69 | 468 | flags = clk_enable_lock(); |
b2476490 MT |
469 | |
470 | if (clk->enable_count) | |
471 | goto unlock_out; | |
472 | ||
473 | if (clk->flags & CLK_IGNORE_UNUSED) | |
474 | goto unlock_out; | |
475 | ||
7c045a55 MT |
476 | /* |
477 | * some gate clocks have special needs during the disable-unused | |
478 | * sequence. call .disable_unused if available, otherwise fall | |
479 | * back to .disable | |
480 | */ | |
481 | if (__clk_is_enabled(clk)) { | |
482 | if (clk->ops->disable_unused) | |
483 | clk->ops->disable_unused(clk->hw); | |
484 | else if (clk->ops->disable) | |
485 | clk->ops->disable(clk->hw); | |
486 | } | |
b2476490 MT |
487 | |
488 | unlock_out: | |
eab89f69 | 489 | clk_enable_unlock(flags); |
b2476490 MT |
490 | |
491 | out: | |
492 | return; | |
493 | } | |
494 | ||
1e435256 OJ |
495 | static bool clk_ignore_unused; |
496 | static int __init clk_ignore_unused_setup(char *__unused) | |
497 | { | |
498 | clk_ignore_unused = true; | |
499 | return 1; | |
500 | } | |
501 | __setup("clk_ignore_unused", clk_ignore_unused_setup); | |
502 | ||
b2476490 MT |
503 | static int clk_disable_unused(void) |
504 | { | |
505 | struct clk *clk; | |
b2476490 | 506 | |
1e435256 OJ |
507 | if (clk_ignore_unused) { |
508 | pr_warn("clk: Not disabling unused clocks\n"); | |
509 | return 0; | |
510 | } | |
511 | ||
eab89f69 | 512 | clk_prepare_lock(); |
b2476490 | 513 | |
b67bfe0d | 514 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
b2476490 MT |
515 | clk_disable_unused_subtree(clk); |
516 | ||
b67bfe0d | 517 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) |
b2476490 MT |
518 | clk_disable_unused_subtree(clk); |
519 | ||
1c155b3d UH |
520 | hlist_for_each_entry(clk, &clk_root_list, child_node) |
521 | clk_unprepare_unused_subtree(clk); | |
522 | ||
523 | hlist_for_each_entry(clk, &clk_orphan_list, child_node) | |
524 | clk_unprepare_unused_subtree(clk); | |
525 | ||
eab89f69 | 526 | clk_prepare_unlock(); |
b2476490 MT |
527 | |
528 | return 0; | |
529 | } | |
d41d5805 | 530 | late_initcall_sync(clk_disable_unused); |
b2476490 MT |
531 | |
532 | /*** helper functions ***/ | |
533 | ||
65800b2c | 534 | const char *__clk_get_name(struct clk *clk) |
b2476490 MT |
535 | { |
536 | return !clk ? NULL : clk->name; | |
537 | } | |
4895084c | 538 | EXPORT_SYMBOL_GPL(__clk_get_name); |
b2476490 | 539 | |
65800b2c | 540 | struct clk_hw *__clk_get_hw(struct clk *clk) |
b2476490 MT |
541 | { |
542 | return !clk ? NULL : clk->hw; | |
543 | } | |
0b7f04b8 | 544 | EXPORT_SYMBOL_GPL(__clk_get_hw); |
b2476490 | 545 | |
65800b2c | 546 | u8 __clk_get_num_parents(struct clk *clk) |
b2476490 | 547 | { |
2ac6b1f5 | 548 | return !clk ? 0 : clk->num_parents; |
b2476490 | 549 | } |
0b7f04b8 | 550 | EXPORT_SYMBOL_GPL(__clk_get_num_parents); |
b2476490 | 551 | |
65800b2c | 552 | struct clk *__clk_get_parent(struct clk *clk) |
b2476490 MT |
553 | { |
554 | return !clk ? NULL : clk->parent; | |
555 | } | |
0b7f04b8 | 556 | EXPORT_SYMBOL_GPL(__clk_get_parent); |
b2476490 | 557 | |
7ef3dcc8 JH |
558 | struct clk *clk_get_parent_by_index(struct clk *clk, u8 index) |
559 | { | |
560 | if (!clk || index >= clk->num_parents) | |
561 | return NULL; | |
562 | else if (!clk->parents) | |
563 | return __clk_lookup(clk->parent_names[index]); | |
564 | else if (!clk->parents[index]) | |
565 | return clk->parents[index] = | |
566 | __clk_lookup(clk->parent_names[index]); | |
567 | else | |
568 | return clk->parents[index]; | |
569 | } | |
0b7f04b8 | 570 | EXPORT_SYMBOL_GPL(clk_get_parent_by_index); |
7ef3dcc8 | 571 | |
65800b2c | 572 | unsigned int __clk_get_enable_count(struct clk *clk) |
b2476490 | 573 | { |
2ac6b1f5 | 574 | return !clk ? 0 : clk->enable_count; |
b2476490 MT |
575 | } |
576 | ||
65800b2c | 577 | unsigned int __clk_get_prepare_count(struct clk *clk) |
b2476490 | 578 | { |
2ac6b1f5 | 579 | return !clk ? 0 : clk->prepare_count; |
b2476490 MT |
580 | } |
581 | ||
582 | unsigned long __clk_get_rate(struct clk *clk) | |
583 | { | |
584 | unsigned long ret; | |
585 | ||
586 | if (!clk) { | |
34e44fe8 | 587 | ret = 0; |
b2476490 MT |
588 | goto out; |
589 | } | |
590 | ||
591 | ret = clk->rate; | |
592 | ||
593 | if (clk->flags & CLK_IS_ROOT) | |
594 | goto out; | |
595 | ||
596 | if (!clk->parent) | |
34e44fe8 | 597 | ret = 0; |
b2476490 MT |
598 | |
599 | out: | |
600 | return ret; | |
601 | } | |
0b7f04b8 | 602 | EXPORT_SYMBOL_GPL(__clk_get_rate); |
b2476490 | 603 | |
5279fc40 BB |
604 | unsigned long __clk_get_accuracy(struct clk *clk) |
605 | { | |
606 | if (!clk) | |
607 | return 0; | |
608 | ||
609 | return clk->accuracy; | |
610 | } | |
611 | ||
65800b2c | 612 | unsigned long __clk_get_flags(struct clk *clk) |
b2476490 | 613 | { |
2ac6b1f5 | 614 | return !clk ? 0 : clk->flags; |
b2476490 | 615 | } |
b05c6836 | 616 | EXPORT_SYMBOL_GPL(__clk_get_flags); |
b2476490 | 617 | |
3d6ee287 UH |
618 | bool __clk_is_prepared(struct clk *clk) |
619 | { | |
620 | int ret; | |
621 | ||
622 | if (!clk) | |
623 | return false; | |
624 | ||
625 | /* | |
626 | * .is_prepared is optional for clocks that can prepare | |
627 | * fall back to software usage counter if it is missing | |
628 | */ | |
629 | if (!clk->ops->is_prepared) { | |
630 | ret = clk->prepare_count ? 1 : 0; | |
631 | goto out; | |
632 | } | |
633 | ||
634 | ret = clk->ops->is_prepared(clk->hw); | |
635 | out: | |
636 | return !!ret; | |
637 | } | |
638 | ||
2ac6b1f5 | 639 | bool __clk_is_enabled(struct clk *clk) |
b2476490 MT |
640 | { |
641 | int ret; | |
642 | ||
643 | if (!clk) | |
2ac6b1f5 | 644 | return false; |
b2476490 MT |
645 | |
646 | /* | |
647 | * .is_enabled is only mandatory for clocks that gate | |
648 | * fall back to software usage counter if .is_enabled is missing | |
649 | */ | |
650 | if (!clk->ops->is_enabled) { | |
651 | ret = clk->enable_count ? 1 : 0; | |
652 | goto out; | |
653 | } | |
654 | ||
655 | ret = clk->ops->is_enabled(clk->hw); | |
656 | out: | |
2ac6b1f5 | 657 | return !!ret; |
b2476490 | 658 | } |
0b7f04b8 | 659 | EXPORT_SYMBOL_GPL(__clk_is_enabled); |
b2476490 MT |
660 | |
661 | static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) | |
662 | { | |
663 | struct clk *child; | |
664 | struct clk *ret; | |
b2476490 MT |
665 | |
666 | if (!strcmp(clk->name, name)) | |
667 | return clk; | |
668 | ||
b67bfe0d | 669 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 MT |
670 | ret = __clk_lookup_subtree(name, child); |
671 | if (ret) | |
672 | return ret; | |
673 | } | |
674 | ||
675 | return NULL; | |
676 | } | |
677 | ||
678 | struct clk *__clk_lookup(const char *name) | |
679 | { | |
680 | struct clk *root_clk; | |
681 | struct clk *ret; | |
b2476490 MT |
682 | |
683 | if (!name) | |
684 | return NULL; | |
685 | ||
686 | /* search the 'proper' clk tree first */ | |
b67bfe0d | 687 | hlist_for_each_entry(root_clk, &clk_root_list, child_node) { |
b2476490 MT |
688 | ret = __clk_lookup_subtree(name, root_clk); |
689 | if (ret) | |
690 | return ret; | |
691 | } | |
692 | ||
693 | /* if not found, then search the orphan tree */ | |
b67bfe0d | 694 | hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { |
b2476490 MT |
695 | ret = __clk_lookup_subtree(name, root_clk); |
696 | if (ret) | |
697 | return ret; | |
698 | } | |
699 | ||
700 | return NULL; | |
701 | } | |
702 | ||
e366fdd7 JH |
703 | /* |
704 | * Helper for finding best parent to provide a given frequency. This can be used | |
705 | * directly as a determine_rate callback (e.g. for a mux), or from a more | |
706 | * complex clock that may combine a mux with other operations. | |
707 | */ | |
708 | long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate, | |
709 | unsigned long *best_parent_rate, | |
710 | struct clk **best_parent_p) | |
711 | { | |
712 | struct clk *clk = hw->clk, *parent, *best_parent = NULL; | |
713 | int i, num_parents; | |
714 | unsigned long parent_rate, best = 0; | |
715 | ||
716 | /* if NO_REPARENT flag set, pass through to current parent */ | |
717 | if (clk->flags & CLK_SET_RATE_NO_REPARENT) { | |
718 | parent = clk->parent; | |
719 | if (clk->flags & CLK_SET_RATE_PARENT) | |
720 | best = __clk_round_rate(parent, rate); | |
721 | else if (parent) | |
722 | best = __clk_get_rate(parent); | |
723 | else | |
724 | best = __clk_get_rate(clk); | |
725 | goto out; | |
726 | } | |
727 | ||
728 | /* find the parent that can provide the fastest rate <= rate */ | |
729 | num_parents = clk->num_parents; | |
730 | for (i = 0; i < num_parents; i++) { | |
731 | parent = clk_get_parent_by_index(clk, i); | |
732 | if (!parent) | |
733 | continue; | |
734 | if (clk->flags & CLK_SET_RATE_PARENT) | |
735 | parent_rate = __clk_round_rate(parent, rate); | |
736 | else | |
737 | parent_rate = __clk_get_rate(parent); | |
738 | if (parent_rate <= rate && parent_rate > best) { | |
739 | best_parent = parent; | |
740 | best = parent_rate; | |
741 | } | |
742 | } | |
743 | ||
744 | out: | |
745 | if (best_parent) | |
746 | *best_parent_p = best_parent; | |
747 | *best_parent_rate = best; | |
748 | ||
749 | return best; | |
750 | } | |
0b7f04b8 | 751 | EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); |
e366fdd7 | 752 | |
b2476490 MT |
753 | /*** clk api ***/ |
754 | ||
755 | void __clk_unprepare(struct clk *clk) | |
756 | { | |
757 | if (!clk) | |
758 | return; | |
759 | ||
760 | if (WARN_ON(clk->prepare_count == 0)) | |
761 | return; | |
762 | ||
763 | if (--clk->prepare_count > 0) | |
764 | return; | |
765 | ||
766 | WARN_ON(clk->enable_count > 0); | |
767 | ||
768 | if (clk->ops->unprepare) | |
769 | clk->ops->unprepare(clk->hw); | |
770 | ||
771 | __clk_unprepare(clk->parent); | |
772 | } | |
773 | ||
774 | /** | |
775 | * clk_unprepare - undo preparation of a clock source | |
24ee1a08 | 776 | * @clk: the clk being unprepared |
b2476490 MT |
777 | * |
778 | * clk_unprepare may sleep, which differentiates it from clk_disable. In a | |
779 | * simple case, clk_unprepare can be used instead of clk_disable to gate a clk | |
780 | * if the operation may sleep. One example is a clk which is accessed over | |
781 | * I2c. In the complex case a clk gate operation may require a fast and a slow | |
782 | * part. It is this reason that clk_unprepare and clk_disable are not mutually | |
783 | * exclusive. In fact clk_disable must be called before clk_unprepare. | |
784 | */ | |
785 | void clk_unprepare(struct clk *clk) | |
786 | { | |
63589e92 SB |
787 | if (IS_ERR_OR_NULL(clk)) |
788 | return; | |
789 | ||
eab89f69 | 790 | clk_prepare_lock(); |
b2476490 | 791 | __clk_unprepare(clk); |
eab89f69 | 792 | clk_prepare_unlock(); |
b2476490 MT |
793 | } |
794 | EXPORT_SYMBOL_GPL(clk_unprepare); | |
795 | ||
796 | int __clk_prepare(struct clk *clk) | |
797 | { | |
798 | int ret = 0; | |
799 | ||
800 | if (!clk) | |
801 | return 0; | |
802 | ||
803 | if (clk->prepare_count == 0) { | |
804 | ret = __clk_prepare(clk->parent); | |
805 | if (ret) | |
806 | return ret; | |
807 | ||
808 | if (clk->ops->prepare) { | |
809 | ret = clk->ops->prepare(clk->hw); | |
810 | if (ret) { | |
811 | __clk_unprepare(clk->parent); | |
812 | return ret; | |
813 | } | |
814 | } | |
815 | } | |
816 | ||
817 | clk->prepare_count++; | |
818 | ||
819 | return 0; | |
820 | } | |
821 | ||
822 | /** | |
823 | * clk_prepare - prepare a clock source | |
824 | * @clk: the clk being prepared | |
825 | * | |
826 | * clk_prepare may sleep, which differentiates it from clk_enable. In a simple | |
827 | * case, clk_prepare can be used instead of clk_enable to ungate a clk if the | |
828 | * operation may sleep. One example is a clk which is accessed over I2c. In | |
829 | * the complex case a clk ungate operation may require a fast and a slow part. | |
830 | * It is this reason that clk_prepare and clk_enable are not mutually | |
831 | * exclusive. In fact clk_prepare must be called before clk_enable. | |
832 | * Returns 0 on success, -EERROR otherwise. | |
833 | */ | |
834 | int clk_prepare(struct clk *clk) | |
835 | { | |
836 | int ret; | |
837 | ||
eab89f69 | 838 | clk_prepare_lock(); |
b2476490 | 839 | ret = __clk_prepare(clk); |
eab89f69 | 840 | clk_prepare_unlock(); |
b2476490 MT |
841 | |
842 | return ret; | |
843 | } | |
844 | EXPORT_SYMBOL_GPL(clk_prepare); | |
845 | ||
846 | static void __clk_disable(struct clk *clk) | |
847 | { | |
848 | if (!clk) | |
849 | return; | |
850 | ||
851 | if (WARN_ON(clk->enable_count == 0)) | |
852 | return; | |
853 | ||
854 | if (--clk->enable_count > 0) | |
855 | return; | |
856 | ||
857 | if (clk->ops->disable) | |
858 | clk->ops->disable(clk->hw); | |
859 | ||
860 | __clk_disable(clk->parent); | |
861 | } | |
862 | ||
863 | /** | |
864 | * clk_disable - gate a clock | |
865 | * @clk: the clk being gated | |
866 | * | |
867 | * clk_disable must not sleep, which differentiates it from clk_unprepare. In | |
868 | * a simple case, clk_disable can be used instead of clk_unprepare to gate a | |
869 | * clk if the operation is fast and will never sleep. One example is a | |
870 | * SoC-internal clk which is controlled via simple register writes. In the | |
871 | * complex case a clk gate operation may require a fast and a slow part. It is | |
872 | * this reason that clk_unprepare and clk_disable are not mutually exclusive. | |
873 | * In fact clk_disable must be called before clk_unprepare. | |
874 | */ | |
875 | void clk_disable(struct clk *clk) | |
876 | { | |
877 | unsigned long flags; | |
878 | ||
63589e92 SB |
879 | if (IS_ERR_OR_NULL(clk)) |
880 | return; | |
881 | ||
eab89f69 | 882 | flags = clk_enable_lock(); |
b2476490 | 883 | __clk_disable(clk); |
eab89f69 | 884 | clk_enable_unlock(flags); |
b2476490 MT |
885 | } |
886 | EXPORT_SYMBOL_GPL(clk_disable); | |
887 | ||
888 | static int __clk_enable(struct clk *clk) | |
889 | { | |
890 | int ret = 0; | |
891 | ||
892 | if (!clk) | |
893 | return 0; | |
894 | ||
895 | if (WARN_ON(clk->prepare_count == 0)) | |
896 | return -ESHUTDOWN; | |
897 | ||
898 | if (clk->enable_count == 0) { | |
899 | ret = __clk_enable(clk->parent); | |
900 | ||
901 | if (ret) | |
902 | return ret; | |
903 | ||
904 | if (clk->ops->enable) { | |
905 | ret = clk->ops->enable(clk->hw); | |
906 | if (ret) { | |
907 | __clk_disable(clk->parent); | |
908 | return ret; | |
909 | } | |
910 | } | |
911 | } | |
912 | ||
913 | clk->enable_count++; | |
914 | return 0; | |
915 | } | |
916 | ||
917 | /** | |
918 | * clk_enable - ungate a clock | |
919 | * @clk: the clk being ungated | |
920 | * | |
921 | * clk_enable must not sleep, which differentiates it from clk_prepare. In a | |
922 | * simple case, clk_enable can be used instead of clk_prepare to ungate a clk | |
923 | * if the operation will never sleep. One example is a SoC-internal clk which | |
924 | * is controlled via simple register writes. In the complex case a clk ungate | |
925 | * operation may require a fast and a slow part. It is this reason that | |
926 | * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare | |
927 | * must be called before clk_enable. Returns 0 on success, -EERROR | |
928 | * otherwise. | |
929 | */ | |
930 | int clk_enable(struct clk *clk) | |
931 | { | |
932 | unsigned long flags; | |
933 | int ret; | |
934 | ||
eab89f69 | 935 | flags = clk_enable_lock(); |
b2476490 | 936 | ret = __clk_enable(clk); |
eab89f69 | 937 | clk_enable_unlock(flags); |
b2476490 MT |
938 | |
939 | return ret; | |
940 | } | |
941 | EXPORT_SYMBOL_GPL(clk_enable); | |
942 | ||
b2476490 MT |
943 | /** |
944 | * __clk_round_rate - round the given rate for a clk | |
945 | * @clk: round the rate of this clock | |
24ee1a08 | 946 | * @rate: the rate which is to be rounded |
b2476490 MT |
947 | * |
948 | * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate | |
949 | */ | |
950 | unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) | |
951 | { | |
81536e07 | 952 | unsigned long parent_rate = 0; |
71472c0c | 953 | struct clk *parent; |
b2476490 MT |
954 | |
955 | if (!clk) | |
2ac6b1f5 | 956 | return 0; |
b2476490 | 957 | |
71472c0c JH |
958 | parent = clk->parent; |
959 | if (parent) | |
960 | parent_rate = parent->rate; | |
961 | ||
962 | if (clk->ops->determine_rate) | |
963 | return clk->ops->determine_rate(clk->hw, rate, &parent_rate, | |
964 | &parent); | |
965 | else if (clk->ops->round_rate) | |
966 | return clk->ops->round_rate(clk->hw, rate, &parent_rate); | |
967 | else if (clk->flags & CLK_SET_RATE_PARENT) | |
968 | return __clk_round_rate(clk->parent, rate); | |
969 | else | |
970 | return clk->rate; | |
b2476490 | 971 | } |
1cdf8ee2 | 972 | EXPORT_SYMBOL_GPL(__clk_round_rate); |
b2476490 MT |
973 | |
974 | /** | |
975 | * clk_round_rate - round the given rate for a clk | |
976 | * @clk: the clk for which we are rounding a rate | |
977 | * @rate: the rate which is to be rounded | |
978 | * | |
979 | * Takes in a rate as input and rounds it to a rate that the clk can actually | |
980 | * use which is then returned. If clk doesn't support round_rate operation | |
981 | * then the parent rate is returned. | |
982 | */ | |
983 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
984 | { | |
985 | unsigned long ret; | |
986 | ||
eab89f69 | 987 | clk_prepare_lock(); |
b2476490 | 988 | ret = __clk_round_rate(clk, rate); |
eab89f69 | 989 | clk_prepare_unlock(); |
b2476490 MT |
990 | |
991 | return ret; | |
992 | } | |
993 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
994 | ||
995 | /** | |
996 | * __clk_notify - call clk notifier chain | |
997 | * @clk: struct clk * that is changing rate | |
998 | * @msg: clk notifier type (see include/linux/clk.h) | |
999 | * @old_rate: old clk rate | |
1000 | * @new_rate: new clk rate | |
1001 | * | |
1002 | * Triggers a notifier call chain on the clk rate-change notification | |
1003 | * for 'clk'. Passes a pointer to the struct clk and the previous | |
1004 | * and current rates to the notifier callback. Intended to be called by | |
1005 | * internal clock code only. Returns NOTIFY_DONE from the last driver | |
1006 | * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if | |
1007 | * a driver returns that. | |
1008 | */ | |
1009 | static int __clk_notify(struct clk *clk, unsigned long msg, | |
1010 | unsigned long old_rate, unsigned long new_rate) | |
1011 | { | |
1012 | struct clk_notifier *cn; | |
1013 | struct clk_notifier_data cnd; | |
1014 | int ret = NOTIFY_DONE; | |
1015 | ||
1016 | cnd.clk = clk; | |
1017 | cnd.old_rate = old_rate; | |
1018 | cnd.new_rate = new_rate; | |
1019 | ||
1020 | list_for_each_entry(cn, &clk_notifier_list, node) { | |
1021 | if (cn->clk == clk) { | |
1022 | ret = srcu_notifier_call_chain(&cn->notifier_head, msg, | |
1023 | &cnd); | |
1024 | break; | |
1025 | } | |
1026 | } | |
1027 | ||
1028 | return ret; | |
1029 | } | |
1030 | ||
5279fc40 BB |
1031 | /** |
1032 | * __clk_recalc_accuracies | |
1033 | * @clk: first clk in the subtree | |
1034 | * | |
1035 | * Walks the subtree of clks starting with clk and recalculates accuracies as | |
1036 | * it goes. Note that if a clk does not implement the .recalc_accuracy | |
1037 | * callback then it is assumed that the clock will take on the accuracy of it's | |
1038 | * parent. | |
1039 | * | |
1040 | * Caller must hold prepare_lock. | |
1041 | */ | |
1042 | static void __clk_recalc_accuracies(struct clk *clk) | |
1043 | { | |
1044 | unsigned long parent_accuracy = 0; | |
1045 | struct clk *child; | |
1046 | ||
1047 | if (clk->parent) | |
1048 | parent_accuracy = clk->parent->accuracy; | |
1049 | ||
1050 | if (clk->ops->recalc_accuracy) | |
1051 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1052 | parent_accuracy); | |
1053 | else | |
1054 | clk->accuracy = parent_accuracy; | |
1055 | ||
1056 | hlist_for_each_entry(child, &clk->children, child_node) | |
1057 | __clk_recalc_accuracies(child); | |
1058 | } | |
1059 | ||
1060 | /** | |
1061 | * clk_get_accuracy - return the accuracy of clk | |
1062 | * @clk: the clk whose accuracy is being returned | |
1063 | * | |
1064 | * Simply returns the cached accuracy of the clk, unless | |
1065 | * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be | |
1066 | * issued. | |
1067 | * If clk is NULL then returns 0. | |
1068 | */ | |
1069 | long clk_get_accuracy(struct clk *clk) | |
1070 | { | |
1071 | unsigned long accuracy; | |
1072 | ||
1073 | clk_prepare_lock(); | |
1074 | if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE)) | |
1075 | __clk_recalc_accuracies(clk); | |
1076 | ||
1077 | accuracy = __clk_get_accuracy(clk); | |
1078 | clk_prepare_unlock(); | |
1079 | ||
1080 | return accuracy; | |
1081 | } | |
1082 | EXPORT_SYMBOL_GPL(clk_get_accuracy); | |
1083 | ||
8f2c2db1 SB |
1084 | static unsigned long clk_recalc(struct clk *clk, unsigned long parent_rate) |
1085 | { | |
1086 | if (clk->ops->recalc_rate) | |
1087 | return clk->ops->recalc_rate(clk->hw, parent_rate); | |
1088 | return parent_rate; | |
1089 | } | |
1090 | ||
b2476490 MT |
1091 | /** |
1092 | * __clk_recalc_rates | |
1093 | * @clk: first clk in the subtree | |
1094 | * @msg: notification type (see include/linux/clk.h) | |
1095 | * | |
1096 | * Walks the subtree of clks starting with clk and recalculates rates as it | |
1097 | * goes. Note that if a clk does not implement the .recalc_rate callback then | |
24ee1a08 | 1098 | * it is assumed that the clock will take on the rate of its parent. |
b2476490 MT |
1099 | * |
1100 | * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, | |
1101 | * if necessary. | |
1102 | * | |
1103 | * Caller must hold prepare_lock. | |
1104 | */ | |
1105 | static void __clk_recalc_rates(struct clk *clk, unsigned long msg) | |
1106 | { | |
1107 | unsigned long old_rate; | |
1108 | unsigned long parent_rate = 0; | |
b2476490 MT |
1109 | struct clk *child; |
1110 | ||
1111 | old_rate = clk->rate; | |
1112 | ||
1113 | if (clk->parent) | |
1114 | parent_rate = clk->parent->rate; | |
1115 | ||
8f2c2db1 | 1116 | clk->rate = clk_recalc(clk, parent_rate); |
b2476490 MT |
1117 | |
1118 | /* | |
1119 | * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE | |
1120 | * & ABORT_RATE_CHANGE notifiers | |
1121 | */ | |
1122 | if (clk->notifier_count && msg) | |
1123 | __clk_notify(clk, msg, old_rate, clk->rate); | |
1124 | ||
b67bfe0d | 1125 | hlist_for_each_entry(child, &clk->children, child_node) |
b2476490 MT |
1126 | __clk_recalc_rates(child, msg); |
1127 | } | |
1128 | ||
a093bde2 UH |
1129 | /** |
1130 | * clk_get_rate - return the rate of clk | |
1131 | * @clk: the clk whose rate is being returned | |
1132 | * | |
1133 | * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag | |
1134 | * is set, which means a recalc_rate will be issued. | |
1135 | * If clk is NULL then returns 0. | |
1136 | */ | |
1137 | unsigned long clk_get_rate(struct clk *clk) | |
1138 | { | |
1139 | unsigned long rate; | |
1140 | ||
eab89f69 | 1141 | clk_prepare_lock(); |
a093bde2 UH |
1142 | |
1143 | if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) | |
1144 | __clk_recalc_rates(clk, 0); | |
1145 | ||
1146 | rate = __clk_get_rate(clk); | |
eab89f69 | 1147 | clk_prepare_unlock(); |
a093bde2 UH |
1148 | |
1149 | return rate; | |
1150 | } | |
1151 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
1152 | ||
f1c8b2ed | 1153 | static int clk_fetch_parent_index(struct clk *clk, struct clk *parent) |
4935b22c | 1154 | { |
f1c8b2ed | 1155 | int i; |
4935b22c | 1156 | |
f1c8b2ed | 1157 | if (!clk->parents) { |
96a7ed90 TF |
1158 | clk->parents = kcalloc(clk->num_parents, |
1159 | sizeof(struct clk *), GFP_KERNEL); | |
f1c8b2ed TF |
1160 | if (!clk->parents) |
1161 | return -ENOMEM; | |
1162 | } | |
4935b22c JH |
1163 | |
1164 | /* | |
1165 | * find index of new parent clock using cached parent ptrs, | |
1166 | * or if not yet cached, use string name comparison and cache | |
1167 | * them now to avoid future calls to __clk_lookup. | |
1168 | */ | |
1169 | for (i = 0; i < clk->num_parents; i++) { | |
da0f0b2c | 1170 | if (clk->parents[i] == parent) |
f1c8b2ed | 1171 | return i; |
da0f0b2c TF |
1172 | |
1173 | if (clk->parents[i]) | |
1174 | continue; | |
1175 | ||
1176 | if (!strcmp(clk->parent_names[i], parent->name)) { | |
1177 | clk->parents[i] = __clk_lookup(parent->name); | |
f1c8b2ed | 1178 | return i; |
4935b22c JH |
1179 | } |
1180 | } | |
1181 | ||
f1c8b2ed | 1182 | return -EINVAL; |
4935b22c JH |
1183 | } |
1184 | ||
1185 | static void clk_reparent(struct clk *clk, struct clk *new_parent) | |
1186 | { | |
1187 | hlist_del(&clk->child_node); | |
1188 | ||
903efc55 JH |
1189 | if (new_parent) { |
1190 | /* avoid duplicate POST_RATE_CHANGE notifications */ | |
1191 | if (new_parent->new_child == clk) | |
1192 | new_parent->new_child = NULL; | |
1193 | ||
4935b22c | 1194 | hlist_add_head(&clk->child_node, &new_parent->children); |
903efc55 | 1195 | } else { |
4935b22c | 1196 | hlist_add_head(&clk->child_node, &clk_orphan_list); |
903efc55 | 1197 | } |
4935b22c JH |
1198 | |
1199 | clk->parent = new_parent; | |
1200 | } | |
1201 | ||
3fa2252b | 1202 | static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent) |
4935b22c JH |
1203 | { |
1204 | unsigned long flags; | |
4935b22c JH |
1205 | struct clk *old_parent = clk->parent; |
1206 | ||
1207 | /* | |
1208 | * Migrate prepare state between parents and prevent race with | |
1209 | * clk_enable(). | |
1210 | * | |
1211 | * If the clock is not prepared, then a race with | |
1212 | * clk_enable/disable() is impossible since we already have the | |
1213 | * prepare lock (future calls to clk_enable() need to be preceded by | |
1214 | * a clk_prepare()). | |
1215 | * | |
1216 | * If the clock is prepared, migrate the prepared state to the new | |
1217 | * parent and also protect against a race with clk_enable() by | |
1218 | * forcing the clock and the new parent on. This ensures that all | |
1219 | * future calls to clk_enable() are practically NOPs with respect to | |
1220 | * hardware and software states. | |
1221 | * | |
1222 | * See also: Comment for clk_set_parent() below. | |
1223 | */ | |
1224 | if (clk->prepare_count) { | |
1225 | __clk_prepare(parent); | |
1226 | clk_enable(parent); | |
1227 | clk_enable(clk); | |
1228 | } | |
1229 | ||
1230 | /* update the clk tree topology */ | |
1231 | flags = clk_enable_lock(); | |
1232 | clk_reparent(clk, parent); | |
1233 | clk_enable_unlock(flags); | |
1234 | ||
3fa2252b SB |
1235 | return old_parent; |
1236 | } | |
1237 | ||
1238 | static void __clk_set_parent_after(struct clk *clk, struct clk *parent, | |
1239 | struct clk *old_parent) | |
1240 | { | |
1241 | /* | |
1242 | * Finish the migration of prepare state and undo the changes done | |
1243 | * for preventing a race with clk_enable(). | |
1244 | */ | |
1245 | if (clk->prepare_count) { | |
1246 | clk_disable(clk); | |
1247 | clk_disable(old_parent); | |
1248 | __clk_unprepare(old_parent); | |
1249 | } | |
3fa2252b SB |
1250 | } |
1251 | ||
1252 | static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) | |
1253 | { | |
1254 | unsigned long flags; | |
1255 | int ret = 0; | |
1256 | struct clk *old_parent; | |
1257 | ||
1258 | old_parent = __clk_set_parent_before(clk, parent); | |
1259 | ||
4935b22c JH |
1260 | /* change clock input source */ |
1261 | if (parent && clk->ops->set_parent) | |
1262 | ret = clk->ops->set_parent(clk->hw, p_index); | |
1263 | ||
1264 | if (ret) { | |
1265 | flags = clk_enable_lock(); | |
1266 | clk_reparent(clk, old_parent); | |
1267 | clk_enable_unlock(flags); | |
1268 | ||
1269 | if (clk->prepare_count) { | |
1270 | clk_disable(clk); | |
1271 | clk_disable(parent); | |
1272 | __clk_unprepare(parent); | |
1273 | } | |
1274 | return ret; | |
1275 | } | |
1276 | ||
3fa2252b | 1277 | __clk_set_parent_after(clk, parent, old_parent); |
4935b22c | 1278 | |
4935b22c JH |
1279 | return 0; |
1280 | } | |
1281 | ||
b2476490 MT |
1282 | /** |
1283 | * __clk_speculate_rates | |
1284 | * @clk: first clk in the subtree | |
1285 | * @parent_rate: the "future" rate of clk's parent | |
1286 | * | |
1287 | * Walks the subtree of clks starting with clk, speculating rates as it | |
1288 | * goes and firing off PRE_RATE_CHANGE notifications as necessary. | |
1289 | * | |
1290 | * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending | |
1291 | * pre-rate change notifications and returns early if no clks in the | |
1292 | * subtree have subscribed to the notifications. Note that if a clk does not | |
1293 | * implement the .recalc_rate callback then it is assumed that the clock will | |
24ee1a08 | 1294 | * take on the rate of its parent. |
b2476490 MT |
1295 | * |
1296 | * Caller must hold prepare_lock. | |
1297 | */ | |
1298 | static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) | |
1299 | { | |
b2476490 MT |
1300 | struct clk *child; |
1301 | unsigned long new_rate; | |
1302 | int ret = NOTIFY_DONE; | |
1303 | ||
8f2c2db1 | 1304 | new_rate = clk_recalc(clk, parent_rate); |
b2476490 | 1305 | |
fb72a059 | 1306 | /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ |
b2476490 MT |
1307 | if (clk->notifier_count) |
1308 | ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); | |
1309 | ||
86bcfa2e MT |
1310 | if (ret & NOTIFY_STOP_MASK) { |
1311 | pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n", | |
1312 | __func__, clk->name, ret); | |
b2476490 | 1313 | goto out; |
86bcfa2e | 1314 | } |
b2476490 | 1315 | |
b67bfe0d | 1316 | hlist_for_each_entry(child, &clk->children, child_node) { |
b2476490 | 1317 | ret = __clk_speculate_rates(child, new_rate); |
fb72a059 | 1318 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1319 | break; |
1320 | } | |
1321 | ||
1322 | out: | |
1323 | return ret; | |
1324 | } | |
1325 | ||
71472c0c JH |
1326 | static void clk_calc_subtree(struct clk *clk, unsigned long new_rate, |
1327 | struct clk *new_parent, u8 p_index) | |
b2476490 MT |
1328 | { |
1329 | struct clk *child; | |
b2476490 MT |
1330 | |
1331 | clk->new_rate = new_rate; | |
71472c0c JH |
1332 | clk->new_parent = new_parent; |
1333 | clk->new_parent_index = p_index; | |
1334 | /* include clk in new parent's PRE_RATE_CHANGE notifications */ | |
1335 | clk->new_child = NULL; | |
1336 | if (new_parent && new_parent != clk->parent) | |
1337 | new_parent->new_child = clk; | |
b2476490 | 1338 | |
b67bfe0d | 1339 | hlist_for_each_entry(child, &clk->children, child_node) { |
8f2c2db1 | 1340 | child->new_rate = clk_recalc(child, new_rate); |
71472c0c | 1341 | clk_calc_subtree(child, child->new_rate, NULL, 0); |
b2476490 MT |
1342 | } |
1343 | } | |
1344 | ||
1345 | /* | |
1346 | * calculate the new rates returning the topmost clock that has to be | |
1347 | * changed. | |
1348 | */ | |
1349 | static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) | |
1350 | { | |
1351 | struct clk *top = clk; | |
71472c0c | 1352 | struct clk *old_parent, *parent; |
81536e07 | 1353 | unsigned long best_parent_rate = 0; |
b2476490 | 1354 | unsigned long new_rate; |
f1c8b2ed | 1355 | int p_index = 0; |
b2476490 | 1356 | |
7452b219 MT |
1357 | /* sanity */ |
1358 | if (IS_ERR_OR_NULL(clk)) | |
1359 | return NULL; | |
1360 | ||
63f5c3b2 | 1361 | /* save parent rate, if it exists */ |
71472c0c JH |
1362 | parent = old_parent = clk->parent; |
1363 | if (parent) | |
1364 | best_parent_rate = parent->rate; | |
1365 | ||
1366 | /* find the closest rate and parent clk/rate */ | |
1367 | if (clk->ops->determine_rate) { | |
1368 | new_rate = clk->ops->determine_rate(clk->hw, rate, | |
1369 | &best_parent_rate, | |
1370 | &parent); | |
1371 | } else if (clk->ops->round_rate) { | |
1372 | new_rate = clk->ops->round_rate(clk->hw, rate, | |
1373 | &best_parent_rate); | |
1374 | } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) { | |
1375 | /* pass-through clock without adjustable parent */ | |
1376 | clk->new_rate = clk->rate; | |
1377 | return NULL; | |
1378 | } else { | |
1379 | /* pass-through clock with adjustable parent */ | |
1380 | top = clk_calc_new_rates(parent, rate); | |
1381 | new_rate = parent->new_rate; | |
63f5c3b2 | 1382 | goto out; |
7452b219 MT |
1383 | } |
1384 | ||
71472c0c JH |
1385 | /* some clocks must be gated to change parent */ |
1386 | if (parent != old_parent && | |
1387 | (clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1388 | pr_debug("%s: %s not gated but wants to reparent\n", | |
1389 | __func__, clk->name); | |
b2476490 MT |
1390 | return NULL; |
1391 | } | |
1392 | ||
71472c0c JH |
1393 | /* try finding the new parent index */ |
1394 | if (parent) { | |
1395 | p_index = clk_fetch_parent_index(clk, parent); | |
f1c8b2ed | 1396 | if (p_index < 0) { |
71472c0c JH |
1397 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1398 | __func__, parent->name, clk->name); | |
1399 | return NULL; | |
1400 | } | |
b2476490 MT |
1401 | } |
1402 | ||
71472c0c JH |
1403 | if ((clk->flags & CLK_SET_RATE_PARENT) && parent && |
1404 | best_parent_rate != parent->rate) | |
1405 | top = clk_calc_new_rates(parent, best_parent_rate); | |
b2476490 MT |
1406 | |
1407 | out: | |
71472c0c | 1408 | clk_calc_subtree(clk, new_rate, parent, p_index); |
b2476490 MT |
1409 | |
1410 | return top; | |
1411 | } | |
1412 | ||
1413 | /* | |
1414 | * Notify about rate changes in a subtree. Always walk down the whole tree | |
1415 | * so that in case of an error we can walk down the whole tree again and | |
1416 | * abort the change. | |
1417 | */ | |
1418 | static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) | |
1419 | { | |
71472c0c | 1420 | struct clk *child, *tmp_clk, *fail_clk = NULL; |
b2476490 MT |
1421 | int ret = NOTIFY_DONE; |
1422 | ||
1423 | if (clk->rate == clk->new_rate) | |
5fda6858 | 1424 | return NULL; |
b2476490 MT |
1425 | |
1426 | if (clk->notifier_count) { | |
1427 | ret = __clk_notify(clk, event, clk->rate, clk->new_rate); | |
fb72a059 | 1428 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1429 | fail_clk = clk; |
1430 | } | |
1431 | ||
b67bfe0d | 1432 | hlist_for_each_entry(child, &clk->children, child_node) { |
71472c0c JH |
1433 | /* Skip children who will be reparented to another clock */ |
1434 | if (child->new_parent && child->new_parent != clk) | |
1435 | continue; | |
1436 | tmp_clk = clk_propagate_rate_change(child, event); | |
1437 | if (tmp_clk) | |
1438 | fail_clk = tmp_clk; | |
1439 | } | |
1440 | ||
1441 | /* handle the new child who might not be in clk->children yet */ | |
1442 | if (clk->new_child) { | |
1443 | tmp_clk = clk_propagate_rate_change(clk->new_child, event); | |
1444 | if (tmp_clk) | |
1445 | fail_clk = tmp_clk; | |
b2476490 MT |
1446 | } |
1447 | ||
1448 | return fail_clk; | |
1449 | } | |
1450 | ||
1451 | /* | |
1452 | * walk down a subtree and set the new rates notifying the rate | |
1453 | * change on the way | |
1454 | */ | |
1455 | static void clk_change_rate(struct clk *clk) | |
1456 | { | |
1457 | struct clk *child; | |
067bb174 | 1458 | struct hlist_node *tmp; |
b2476490 | 1459 | unsigned long old_rate; |
bf47b4fd | 1460 | unsigned long best_parent_rate = 0; |
3fa2252b SB |
1461 | bool skip_set_rate = false; |
1462 | struct clk *old_parent; | |
b2476490 MT |
1463 | |
1464 | old_rate = clk->rate; | |
1465 | ||
3fa2252b SB |
1466 | if (clk->new_parent) |
1467 | best_parent_rate = clk->new_parent->rate; | |
1468 | else if (clk->parent) | |
bf47b4fd PM |
1469 | best_parent_rate = clk->parent->rate; |
1470 | ||
3fa2252b SB |
1471 | if (clk->new_parent && clk->new_parent != clk->parent) { |
1472 | old_parent = __clk_set_parent_before(clk, clk->new_parent); | |
1473 | ||
1474 | if (clk->ops->set_rate_and_parent) { | |
1475 | skip_set_rate = true; | |
1476 | clk->ops->set_rate_and_parent(clk->hw, clk->new_rate, | |
1477 | best_parent_rate, | |
1478 | clk->new_parent_index); | |
1479 | } else if (clk->ops->set_parent) { | |
1480 | clk->ops->set_parent(clk->hw, clk->new_parent_index); | |
1481 | } | |
1482 | ||
1483 | __clk_set_parent_after(clk, clk->new_parent, old_parent); | |
1484 | } | |
1485 | ||
1486 | if (!skip_set_rate && clk->ops->set_rate) | |
bf47b4fd | 1487 | clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); |
b2476490 | 1488 | |
8f2c2db1 | 1489 | clk->rate = clk_recalc(clk, best_parent_rate); |
b2476490 MT |
1490 | |
1491 | if (clk->notifier_count && old_rate != clk->rate) | |
1492 | __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); | |
1493 | ||
067bb174 TK |
1494 | /* |
1495 | * Use safe iteration, as change_rate can actually swap parents | |
1496 | * for certain clock types. | |
1497 | */ | |
1498 | hlist_for_each_entry_safe(child, tmp, &clk->children, child_node) { | |
71472c0c JH |
1499 | /* Skip children who will be reparented to another clock */ |
1500 | if (child->new_parent && child->new_parent != clk) | |
1501 | continue; | |
b2476490 | 1502 | clk_change_rate(child); |
71472c0c JH |
1503 | } |
1504 | ||
1505 | /* handle the new child who might not be in clk->children yet */ | |
1506 | if (clk->new_child) | |
1507 | clk_change_rate(clk->new_child); | |
b2476490 MT |
1508 | } |
1509 | ||
1510 | /** | |
1511 | * clk_set_rate - specify a new rate for clk | |
1512 | * @clk: the clk whose rate is being changed | |
1513 | * @rate: the new rate for clk | |
1514 | * | |
5654dc94 | 1515 | * In the simplest case clk_set_rate will only adjust the rate of clk. |
b2476490 | 1516 | * |
5654dc94 MT |
1517 | * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to |
1518 | * propagate up to clk's parent; whether or not this happens depends on the | |
1519 | * outcome of clk's .round_rate implementation. If *parent_rate is unchanged | |
1520 | * after calling .round_rate then upstream parent propagation is ignored. If | |
1521 | * *parent_rate comes back with a new rate for clk's parent then we propagate | |
24ee1a08 | 1522 | * up to clk's parent and set its rate. Upward propagation will continue |
5654dc94 MT |
1523 | * until either a clk does not support the CLK_SET_RATE_PARENT flag or |
1524 | * .round_rate stops requesting changes to clk's parent_rate. | |
b2476490 | 1525 | * |
5654dc94 MT |
1526 | * Rate changes are accomplished via tree traversal that also recalculates the |
1527 | * rates for the clocks and fires off POST_RATE_CHANGE notifiers. | |
b2476490 MT |
1528 | * |
1529 | * Returns 0 on success, -EERROR otherwise. | |
1530 | */ | |
1531 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
1532 | { | |
1533 | struct clk *top, *fail_clk; | |
1534 | int ret = 0; | |
1535 | ||
89ac8d7a MT |
1536 | if (!clk) |
1537 | return 0; | |
1538 | ||
b2476490 | 1539 | /* prevent racing with updates to the clock topology */ |
eab89f69 | 1540 | clk_prepare_lock(); |
b2476490 MT |
1541 | |
1542 | /* bail early if nothing to do */ | |
34e452a1 | 1543 | if (rate == clk_get_rate(clk)) |
b2476490 MT |
1544 | goto out; |
1545 | ||
7e0fa1b5 | 1546 | if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { |
0e1c0301 VK |
1547 | ret = -EBUSY; |
1548 | goto out; | |
1549 | } | |
1550 | ||
b2476490 MT |
1551 | /* calculate new rates and get the topmost changed clock */ |
1552 | top = clk_calc_new_rates(clk, rate); | |
1553 | if (!top) { | |
1554 | ret = -EINVAL; | |
1555 | goto out; | |
1556 | } | |
1557 | ||
1558 | /* notify that we are about to change rates */ | |
1559 | fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); | |
1560 | if (fail_clk) { | |
f7363861 | 1561 | pr_debug("%s: failed to set %s rate\n", __func__, |
b2476490 MT |
1562 | fail_clk->name); |
1563 | clk_propagate_rate_change(top, ABORT_RATE_CHANGE); | |
1564 | ret = -EBUSY; | |
1565 | goto out; | |
1566 | } | |
1567 | ||
1568 | /* change the rates */ | |
1569 | clk_change_rate(top); | |
1570 | ||
b2476490 | 1571 | out: |
eab89f69 | 1572 | clk_prepare_unlock(); |
b2476490 MT |
1573 | |
1574 | return ret; | |
1575 | } | |
1576 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
1577 | ||
1578 | /** | |
1579 | * clk_get_parent - return the parent of a clk | |
1580 | * @clk: the clk whose parent gets returned | |
1581 | * | |
1582 | * Simply returns clk->parent. Returns NULL if clk is NULL. | |
1583 | */ | |
1584 | struct clk *clk_get_parent(struct clk *clk) | |
1585 | { | |
1586 | struct clk *parent; | |
1587 | ||
eab89f69 | 1588 | clk_prepare_lock(); |
b2476490 | 1589 | parent = __clk_get_parent(clk); |
eab89f69 | 1590 | clk_prepare_unlock(); |
b2476490 MT |
1591 | |
1592 | return parent; | |
1593 | } | |
1594 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
1595 | ||
1596 | /* | |
1597 | * .get_parent is mandatory for clocks with multiple possible parents. It is | |
1598 | * optional for single-parent clocks. Always call .get_parent if it is | |
1599 | * available and WARN if it is missing for multi-parent clocks. | |
1600 | * | |
1601 | * For single-parent clocks without .get_parent, first check to see if the | |
1602 | * .parents array exists, and if so use it to avoid an expensive tree | |
1603 | * traversal. If .parents does not exist then walk the tree with __clk_lookup. | |
1604 | */ | |
1605 | static struct clk *__clk_init_parent(struct clk *clk) | |
1606 | { | |
1607 | struct clk *ret = NULL; | |
1608 | u8 index; | |
1609 | ||
1610 | /* handle the trivial cases */ | |
1611 | ||
1612 | if (!clk->num_parents) | |
1613 | goto out; | |
1614 | ||
1615 | if (clk->num_parents == 1) { | |
1616 | if (IS_ERR_OR_NULL(clk->parent)) | |
1617 | ret = clk->parent = __clk_lookup(clk->parent_names[0]); | |
1618 | ret = clk->parent; | |
1619 | goto out; | |
1620 | } | |
1621 | ||
1622 | if (!clk->ops->get_parent) { | |
1623 | WARN(!clk->ops->get_parent, | |
1624 | "%s: multi-parent clocks must implement .get_parent\n", | |
1625 | __func__); | |
1626 | goto out; | |
1627 | }; | |
1628 | ||
1629 | /* | |
1630 | * Do our best to cache parent clocks in clk->parents. This prevents | |
1631 | * unnecessary and expensive calls to __clk_lookup. We don't set | |
1632 | * clk->parent here; that is done by the calling function | |
1633 | */ | |
1634 | ||
1635 | index = clk->ops->get_parent(clk->hw); | |
1636 | ||
1637 | if (!clk->parents) | |
1638 | clk->parents = | |
96a7ed90 | 1639 | kcalloc(clk->num_parents, sizeof(struct clk *), |
b2476490 MT |
1640 | GFP_KERNEL); |
1641 | ||
7ef3dcc8 | 1642 | ret = clk_get_parent_by_index(clk, index); |
b2476490 MT |
1643 | |
1644 | out: | |
1645 | return ret; | |
1646 | } | |
1647 | ||
b33d212f UH |
1648 | void __clk_reparent(struct clk *clk, struct clk *new_parent) |
1649 | { | |
1650 | clk_reparent(clk, new_parent); | |
5279fc40 | 1651 | __clk_recalc_accuracies(clk); |
b2476490 MT |
1652 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
1653 | } | |
1654 | ||
b2476490 MT |
1655 | /** |
1656 | * clk_set_parent - switch the parent of a mux clk | |
1657 | * @clk: the mux clk whose input we are switching | |
1658 | * @parent: the new input to clk | |
1659 | * | |
f8aa0bd5 SK |
1660 | * Re-parent clk to use parent as its new input source. If clk is in |
1661 | * prepared state, the clk will get enabled for the duration of this call. If | |
1662 | * that's not acceptable for a specific clk (Eg: the consumer can't handle | |
1663 | * that, the reparenting is glitchy in hardware, etc), use the | |
1664 | * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. | |
1665 | * | |
1666 | * After successfully changing clk's parent clk_set_parent will update the | |
1667 | * clk topology, sysfs topology and propagate rate recalculation via | |
1668 | * __clk_recalc_rates. | |
1669 | * | |
1670 | * Returns 0 on success, -EERROR otherwise. | |
b2476490 MT |
1671 | */ |
1672 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
1673 | { | |
1674 | int ret = 0; | |
f1c8b2ed | 1675 | int p_index = 0; |
031dcc9b | 1676 | unsigned long p_rate = 0; |
b2476490 | 1677 | |
89ac8d7a MT |
1678 | if (!clk) |
1679 | return 0; | |
1680 | ||
031dcc9b UH |
1681 | /* verify ops for for multi-parent clks */ |
1682 | if ((clk->num_parents > 1) && (!clk->ops->set_parent)) | |
b2476490 MT |
1683 | return -ENOSYS; |
1684 | ||
1685 | /* prevent racing with updates to the clock topology */ | |
eab89f69 | 1686 | clk_prepare_lock(); |
b2476490 MT |
1687 | |
1688 | if (clk->parent == parent) | |
1689 | goto out; | |
1690 | ||
031dcc9b UH |
1691 | /* check that we are allowed to re-parent if the clock is in use */ |
1692 | if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { | |
1693 | ret = -EBUSY; | |
1694 | goto out; | |
1695 | } | |
1696 | ||
1697 | /* try finding the new parent index */ | |
1698 | if (parent) { | |
1699 | p_index = clk_fetch_parent_index(clk, parent); | |
1700 | p_rate = parent->rate; | |
f1c8b2ed | 1701 | if (p_index < 0) { |
031dcc9b UH |
1702 | pr_debug("%s: clk %s can not be parent of clk %s\n", |
1703 | __func__, parent->name, clk->name); | |
f1c8b2ed | 1704 | ret = p_index; |
031dcc9b UH |
1705 | goto out; |
1706 | } | |
1707 | } | |
1708 | ||
b2476490 | 1709 | /* propagate PRE_RATE_CHANGE notifications */ |
f3aab5d6 | 1710 | ret = __clk_speculate_rates(clk, p_rate); |
b2476490 MT |
1711 | |
1712 | /* abort if a driver objects */ | |
fb72a059 | 1713 | if (ret & NOTIFY_STOP_MASK) |
b2476490 MT |
1714 | goto out; |
1715 | ||
031dcc9b UH |
1716 | /* do the re-parent */ |
1717 | ret = __clk_set_parent(clk, parent, p_index); | |
b2476490 | 1718 | |
5279fc40 BB |
1719 | /* propagate rate an accuracy recalculation accordingly */ |
1720 | if (ret) { | |
b2476490 | 1721 | __clk_recalc_rates(clk, ABORT_RATE_CHANGE); |
5279fc40 | 1722 | } else { |
a68de8e4 | 1723 | __clk_recalc_rates(clk, POST_RATE_CHANGE); |
5279fc40 BB |
1724 | __clk_recalc_accuracies(clk); |
1725 | } | |
b2476490 MT |
1726 | |
1727 | out: | |
eab89f69 | 1728 | clk_prepare_unlock(); |
b2476490 MT |
1729 | |
1730 | return ret; | |
1731 | } | |
1732 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
1733 | ||
e59c5371 MT |
1734 | /** |
1735 | * clk_set_phase - adjust the phase shift of a clock signal | |
1736 | * @clk: clock signal source | |
1737 | * @degrees: number of degrees the signal is shifted | |
1738 | * | |
1739 | * Shifts the phase of a clock signal by the specified | |
1740 | * degrees. Returns 0 on success, -EERROR otherwise. | |
1741 | * | |
1742 | * This function makes no distinction about the input or reference | |
1743 | * signal that we adjust the clock signal phase against. For example | |
1744 | * phase locked-loop clock signal generators we may shift phase with | |
1745 | * respect to feedback clock signal input, but for other cases the | |
1746 | * clock phase may be shifted with respect to some other, unspecified | |
1747 | * signal. | |
1748 | * | |
1749 | * Additionally the concept of phase shift does not propagate through | |
1750 | * the clock tree hierarchy, which sets it apart from clock rates and | |
1751 | * clock accuracy. A parent clock phase attribute does not have an | |
1752 | * impact on the phase attribute of a child clock. | |
1753 | */ | |
1754 | int clk_set_phase(struct clk *clk, int degrees) | |
1755 | { | |
1756 | int ret = 0; | |
1757 | ||
1758 | if (!clk) | |
1759 | goto out; | |
1760 | ||
1761 | /* sanity check degrees */ | |
1762 | degrees %= 360; | |
1763 | if (degrees < 0) | |
1764 | degrees += 360; | |
1765 | ||
1766 | clk_prepare_lock(); | |
1767 | ||
1768 | if (!clk->ops->set_phase) | |
1769 | goto out_unlock; | |
1770 | ||
1771 | ret = clk->ops->set_phase(clk->hw, degrees); | |
1772 | ||
1773 | if (!ret) | |
1774 | clk->phase = degrees; | |
1775 | ||
1776 | out_unlock: | |
1777 | clk_prepare_unlock(); | |
1778 | ||
1779 | out: | |
1780 | return ret; | |
1781 | } | |
1782 | ||
1783 | /** | |
1784 | * clk_get_phase - return the phase shift of a clock signal | |
1785 | * @clk: clock signal source | |
1786 | * | |
1787 | * Returns the phase shift of a clock node in degrees, otherwise returns | |
1788 | * -EERROR. | |
1789 | */ | |
1790 | int clk_get_phase(struct clk *clk) | |
1791 | { | |
1792 | int ret = 0; | |
1793 | ||
1794 | if (!clk) | |
1795 | goto out; | |
1796 | ||
1797 | clk_prepare_lock(); | |
1798 | ret = clk->phase; | |
1799 | clk_prepare_unlock(); | |
1800 | ||
1801 | out: | |
1802 | return ret; | |
1803 | } | |
1804 | ||
b2476490 MT |
1805 | /** |
1806 | * __clk_init - initialize the data structures in a struct clk | |
1807 | * @dev: device initializing this clk, placeholder for now | |
1808 | * @clk: clk being initialized | |
1809 | * | |
1810 | * Initializes the lists in struct clk, queries the hardware for the | |
1811 | * parent and rate and sets them both. | |
b2476490 | 1812 | */ |
d1302a36 | 1813 | int __clk_init(struct device *dev, struct clk *clk) |
b2476490 | 1814 | { |
d1302a36 | 1815 | int i, ret = 0; |
b2476490 | 1816 | struct clk *orphan; |
b67bfe0d | 1817 | struct hlist_node *tmp2; |
b2476490 MT |
1818 | |
1819 | if (!clk) | |
d1302a36 | 1820 | return -EINVAL; |
b2476490 | 1821 | |
eab89f69 | 1822 | clk_prepare_lock(); |
b2476490 MT |
1823 | |
1824 | /* check to see if a clock with this name is already registered */ | |
d1302a36 MT |
1825 | if (__clk_lookup(clk->name)) { |
1826 | pr_debug("%s: clk %s already initialized\n", | |
1827 | __func__, clk->name); | |
1828 | ret = -EEXIST; | |
b2476490 | 1829 | goto out; |
d1302a36 | 1830 | } |
b2476490 | 1831 | |
d4d7e3dd MT |
1832 | /* check that clk_ops are sane. See Documentation/clk.txt */ |
1833 | if (clk->ops->set_rate && | |
71472c0c JH |
1834 | !((clk->ops->round_rate || clk->ops->determine_rate) && |
1835 | clk->ops->recalc_rate)) { | |
1836 | pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", | |
d4d7e3dd | 1837 | __func__, clk->name); |
d1302a36 | 1838 | ret = -EINVAL; |
d4d7e3dd MT |
1839 | goto out; |
1840 | } | |
1841 | ||
1842 | if (clk->ops->set_parent && !clk->ops->get_parent) { | |
1843 | pr_warning("%s: %s must implement .get_parent & .set_parent\n", | |
1844 | __func__, clk->name); | |
d1302a36 | 1845 | ret = -EINVAL; |
d4d7e3dd MT |
1846 | goto out; |
1847 | } | |
1848 | ||
3fa2252b SB |
1849 | if (clk->ops->set_rate_and_parent && |
1850 | !(clk->ops->set_parent && clk->ops->set_rate)) { | |
1851 | pr_warn("%s: %s must implement .set_parent & .set_rate\n", | |
1852 | __func__, clk->name); | |
1853 | ret = -EINVAL; | |
1854 | goto out; | |
1855 | } | |
1856 | ||
b2476490 MT |
1857 | /* throw a WARN if any entries in parent_names are NULL */ |
1858 | for (i = 0; i < clk->num_parents; i++) | |
1859 | WARN(!clk->parent_names[i], | |
1860 | "%s: invalid NULL in %s's .parent_names\n", | |
1861 | __func__, clk->name); | |
1862 | ||
1863 | /* | |
1864 | * Allocate an array of struct clk *'s to avoid unnecessary string | |
1865 | * look-ups of clk's possible parents. This can fail for clocks passed | |
1866 | * in to clk_init during early boot; thus any access to clk->parents[] | |
1867 | * must always check for a NULL pointer and try to populate it if | |
1868 | * necessary. | |
1869 | * | |
1870 | * If clk->parents is not NULL we skip this entire block. This allows | |
1871 | * for clock drivers to statically initialize clk->parents. | |
1872 | */ | |
9ca1c5a4 | 1873 | if (clk->num_parents > 1 && !clk->parents) { |
96a7ed90 TF |
1874 | clk->parents = kcalloc(clk->num_parents, sizeof(struct clk *), |
1875 | GFP_KERNEL); | |
b2476490 MT |
1876 | /* |
1877 | * __clk_lookup returns NULL for parents that have not been | |
1878 | * clk_init'd; thus any access to clk->parents[] must check | |
1879 | * for a NULL pointer. We can always perform lazy lookups for | |
1880 | * missing parents later on. | |
1881 | */ | |
1882 | if (clk->parents) | |
1883 | for (i = 0; i < clk->num_parents; i++) | |
1884 | clk->parents[i] = | |
1885 | __clk_lookup(clk->parent_names[i]); | |
1886 | } | |
1887 | ||
1888 | clk->parent = __clk_init_parent(clk); | |
1889 | ||
1890 | /* | |
1891 | * Populate clk->parent if parent has already been __clk_init'd. If | |
1892 | * parent has not yet been __clk_init'd then place clk in the orphan | |
1893 | * list. If clk has set the CLK_IS_ROOT flag then place it in the root | |
1894 | * clk list. | |
1895 | * | |
1896 | * Every time a new clk is clk_init'd then we walk the list of orphan | |
1897 | * clocks and re-parent any that are children of the clock currently | |
1898 | * being clk_init'd. | |
1899 | */ | |
1900 | if (clk->parent) | |
1901 | hlist_add_head(&clk->child_node, | |
1902 | &clk->parent->children); | |
1903 | else if (clk->flags & CLK_IS_ROOT) | |
1904 | hlist_add_head(&clk->child_node, &clk_root_list); | |
1905 | else | |
1906 | hlist_add_head(&clk->child_node, &clk_orphan_list); | |
1907 | ||
5279fc40 BB |
1908 | /* |
1909 | * Set clk's accuracy. The preferred method is to use | |
1910 | * .recalc_accuracy. For simple clocks and lazy developers the default | |
1911 | * fallback is to use the parent's accuracy. If a clock doesn't have a | |
1912 | * parent (or is orphaned) then accuracy is set to zero (perfect | |
1913 | * clock). | |
1914 | */ | |
1915 | if (clk->ops->recalc_accuracy) | |
1916 | clk->accuracy = clk->ops->recalc_accuracy(clk->hw, | |
1917 | __clk_get_accuracy(clk->parent)); | |
1918 | else if (clk->parent) | |
1919 | clk->accuracy = clk->parent->accuracy; | |
1920 | else | |
1921 | clk->accuracy = 0; | |
1922 | ||
9824cf73 MR |
1923 | /* |
1924 | * Set clk's phase. | |
1925 | * Since a phase is by definition relative to its parent, just | |
1926 | * query the current clock phase, or just assume it's in phase. | |
1927 | */ | |
1928 | if (clk->ops->get_phase) | |
1929 | clk->phase = clk->ops->get_phase(clk->hw); | |
1930 | else | |
1931 | clk->phase = 0; | |
1932 | ||
b2476490 MT |
1933 | /* |
1934 | * Set clk's rate. The preferred method is to use .recalc_rate. For | |
1935 | * simple clocks and lazy developers the default fallback is to use the | |
1936 | * parent's rate. If a clock doesn't have a parent (or is orphaned) | |
1937 | * then rate is set to zero. | |
1938 | */ | |
1939 | if (clk->ops->recalc_rate) | |
1940 | clk->rate = clk->ops->recalc_rate(clk->hw, | |
1941 | __clk_get_rate(clk->parent)); | |
1942 | else if (clk->parent) | |
1943 | clk->rate = clk->parent->rate; | |
1944 | else | |
1945 | clk->rate = 0; | |
1946 | ||
3a5aec24 | 1947 | clk_debug_register(clk); |
b2476490 MT |
1948 | /* |
1949 | * walk the list of orphan clocks and reparent any that are children of | |
1950 | * this clock | |
1951 | */ | |
b67bfe0d | 1952 | hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { |
12d29886 | 1953 | if (orphan->num_parents && orphan->ops->get_parent) { |
1f61e5f1 MF |
1954 | i = orphan->ops->get_parent(orphan->hw); |
1955 | if (!strcmp(clk->name, orphan->parent_names[i])) | |
1956 | __clk_reparent(orphan, clk); | |
1957 | continue; | |
1958 | } | |
1959 | ||
b2476490 MT |
1960 | for (i = 0; i < orphan->num_parents; i++) |
1961 | if (!strcmp(clk->name, orphan->parent_names[i])) { | |
1962 | __clk_reparent(orphan, clk); | |
1963 | break; | |
1964 | } | |
1f61e5f1 | 1965 | } |
b2476490 MT |
1966 | |
1967 | /* | |
1968 | * optional platform-specific magic | |
1969 | * | |
1970 | * The .init callback is not used by any of the basic clock types, but | |
1971 | * exists for weird hardware that must perform initialization magic. | |
1972 | * Please consider other ways of solving initialization problems before | |
24ee1a08 | 1973 | * using this callback, as its use is discouraged. |
b2476490 MT |
1974 | */ |
1975 | if (clk->ops->init) | |
1976 | clk->ops->init(clk->hw); | |
1977 | ||
fcb0ee6a | 1978 | kref_init(&clk->ref); |
b2476490 | 1979 | out: |
eab89f69 | 1980 | clk_prepare_unlock(); |
b2476490 | 1981 | |
d1302a36 | 1982 | return ret; |
b2476490 MT |
1983 | } |
1984 | ||
0197b3ea SK |
1985 | /** |
1986 | * __clk_register - register a clock and return a cookie. | |
1987 | * | |
1988 | * Same as clk_register, except that the .clk field inside hw shall point to a | |
1989 | * preallocated (generally statically allocated) struct clk. None of the fields | |
1990 | * of the struct clk need to be initialized. | |
1991 | * | |
1992 | * The data pointed to by .init and .clk field shall NOT be marked as init | |
1993 | * data. | |
1994 | * | |
1995 | * __clk_register is only exposed via clk-private.h and is intended for use with | |
1996 | * very large numbers of clocks that need to be statically initialized. It is | |
1997 | * a layering violation to include clk-private.h from any code which implements | |
1998 | * a clock's .ops; as such any statically initialized clock data MUST be in a | |
24ee1a08 | 1999 | * separate C file from the logic that implements its operations. Returns 0 |
0197b3ea SK |
2000 | * on success, otherwise an error code. |
2001 | */ | |
2002 | struct clk *__clk_register(struct device *dev, struct clk_hw *hw) | |
2003 | { | |
2004 | int ret; | |
2005 | struct clk *clk; | |
2006 | ||
2007 | clk = hw->clk; | |
2008 | clk->name = hw->init->name; | |
2009 | clk->ops = hw->init->ops; | |
2010 | clk->hw = hw; | |
2011 | clk->flags = hw->init->flags; | |
2012 | clk->parent_names = hw->init->parent_names; | |
2013 | clk->num_parents = hw->init->num_parents; | |
ac2df527 SN |
2014 | if (dev && dev->driver) |
2015 | clk->owner = dev->driver->owner; | |
2016 | else | |
2017 | clk->owner = NULL; | |
0197b3ea SK |
2018 | |
2019 | ret = __clk_init(dev, clk); | |
2020 | if (ret) | |
2021 | return ERR_PTR(ret); | |
2022 | ||
2023 | return clk; | |
2024 | } | |
2025 | EXPORT_SYMBOL_GPL(__clk_register); | |
2026 | ||
293ba3b4 SB |
2027 | /** |
2028 | * clk_register - allocate a new clock, register it and return an opaque cookie | |
2029 | * @dev: device that is registering this clock | |
2030 | * @hw: link to hardware-specific clock data | |
2031 | * | |
2032 | * clk_register is the primary interface for populating the clock tree with new | |
2033 | * clock nodes. It returns a pointer to the newly allocated struct clk which | |
2034 | * cannot be dereferenced by driver code but may be used in conjuction with the | |
2035 | * rest of the clock API. In the event of an error clk_register will return an | |
2036 | * error code; drivers must test for an error code after calling clk_register. | |
2037 | */ | |
2038 | struct clk *clk_register(struct device *dev, struct clk_hw *hw) | |
b2476490 | 2039 | { |
d1302a36 | 2040 | int i, ret; |
293ba3b4 SB |
2041 | struct clk *clk; |
2042 | ||
2043 | clk = kzalloc(sizeof(*clk), GFP_KERNEL); | |
2044 | if (!clk) { | |
2045 | pr_err("%s: could not allocate clk\n", __func__); | |
2046 | ret = -ENOMEM; | |
2047 | goto fail_out; | |
2048 | } | |
b2476490 | 2049 | |
0197b3ea SK |
2050 | clk->name = kstrdup(hw->init->name, GFP_KERNEL); |
2051 | if (!clk->name) { | |
2052 | pr_err("%s: could not allocate clk->name\n", __func__); | |
2053 | ret = -ENOMEM; | |
2054 | goto fail_name; | |
2055 | } | |
2056 | clk->ops = hw->init->ops; | |
ac2df527 SN |
2057 | if (dev && dev->driver) |
2058 | clk->owner = dev->driver->owner; | |
b2476490 | 2059 | clk->hw = hw; |
0197b3ea SK |
2060 | clk->flags = hw->init->flags; |
2061 | clk->num_parents = hw->init->num_parents; | |
b2476490 MT |
2062 | hw->clk = clk; |
2063 | ||
d1302a36 | 2064 | /* allocate local copy in case parent_names is __initdata */ |
96a7ed90 TF |
2065 | clk->parent_names = kcalloc(clk->num_parents, sizeof(char *), |
2066 | GFP_KERNEL); | |
d1302a36 MT |
2067 | |
2068 | if (!clk->parent_names) { | |
2069 | pr_err("%s: could not allocate clk->parent_names\n", __func__); | |
2070 | ret = -ENOMEM; | |
2071 | goto fail_parent_names; | |
2072 | } | |
2073 | ||
2074 | ||
2075 | /* copy each string name in case parent_names is __initdata */ | |
0197b3ea SK |
2076 | for (i = 0; i < clk->num_parents; i++) { |
2077 | clk->parent_names[i] = kstrdup(hw->init->parent_names[i], | |
2078 | GFP_KERNEL); | |
d1302a36 MT |
2079 | if (!clk->parent_names[i]) { |
2080 | pr_err("%s: could not copy parent_names\n", __func__); | |
2081 | ret = -ENOMEM; | |
2082 | goto fail_parent_names_copy; | |
2083 | } | |
2084 | } | |
2085 | ||
2086 | ret = __clk_init(dev, clk); | |
2087 | if (!ret) | |
293ba3b4 | 2088 | return clk; |
b2476490 | 2089 | |
d1302a36 MT |
2090 | fail_parent_names_copy: |
2091 | while (--i >= 0) | |
2092 | kfree(clk->parent_names[i]); | |
2093 | kfree(clk->parent_names); | |
2094 | fail_parent_names: | |
0197b3ea SK |
2095 | kfree(clk->name); |
2096 | fail_name: | |
d1302a36 MT |
2097 | kfree(clk); |
2098 | fail_out: | |
2099 | return ERR_PTR(ret); | |
b2476490 MT |
2100 | } |
2101 | EXPORT_SYMBOL_GPL(clk_register); | |
2102 | ||
fcb0ee6a SN |
2103 | /* |
2104 | * Free memory allocated for a clock. | |
2105 | * Caller must hold prepare_lock. | |
2106 | */ | |
2107 | static void __clk_release(struct kref *ref) | |
2108 | { | |
2109 | struct clk *clk = container_of(ref, struct clk, ref); | |
2110 | int i = clk->num_parents; | |
2111 | ||
2112 | kfree(clk->parents); | |
2113 | while (--i >= 0) | |
2114 | kfree(clk->parent_names[i]); | |
2115 | ||
2116 | kfree(clk->parent_names); | |
2117 | kfree(clk->name); | |
2118 | kfree(clk); | |
2119 | } | |
2120 | ||
2121 | /* | |
2122 | * Empty clk_ops for unregistered clocks. These are used temporarily | |
2123 | * after clk_unregister() was called on a clock and until last clock | |
2124 | * consumer calls clk_put() and the struct clk object is freed. | |
2125 | */ | |
2126 | static int clk_nodrv_prepare_enable(struct clk_hw *hw) | |
2127 | { | |
2128 | return -ENXIO; | |
2129 | } | |
2130 | ||
2131 | static void clk_nodrv_disable_unprepare(struct clk_hw *hw) | |
2132 | { | |
2133 | WARN_ON_ONCE(1); | |
2134 | } | |
2135 | ||
2136 | static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, | |
2137 | unsigned long parent_rate) | |
2138 | { | |
2139 | return -ENXIO; | |
2140 | } | |
2141 | ||
2142 | static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) | |
2143 | { | |
2144 | return -ENXIO; | |
2145 | } | |
2146 | ||
2147 | static const struct clk_ops clk_nodrv_ops = { | |
2148 | .enable = clk_nodrv_prepare_enable, | |
2149 | .disable = clk_nodrv_disable_unprepare, | |
2150 | .prepare = clk_nodrv_prepare_enable, | |
2151 | .unprepare = clk_nodrv_disable_unprepare, | |
2152 | .set_rate = clk_nodrv_set_rate, | |
2153 | .set_parent = clk_nodrv_set_parent, | |
2154 | }; | |
2155 | ||
1df5c939 MB |
2156 | /** |
2157 | * clk_unregister - unregister a currently registered clock | |
2158 | * @clk: clock to unregister | |
1df5c939 | 2159 | */ |
fcb0ee6a SN |
2160 | void clk_unregister(struct clk *clk) |
2161 | { | |
2162 | unsigned long flags; | |
2163 | ||
6314b679 SB |
2164 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) |
2165 | return; | |
2166 | ||
2167 | clk_debug_unregister(clk); | |
fcb0ee6a SN |
2168 | |
2169 | clk_prepare_lock(); | |
2170 | ||
2171 | if (clk->ops == &clk_nodrv_ops) { | |
2172 | pr_err("%s: unregistered clock: %s\n", __func__, clk->name); | |
6314b679 | 2173 | return; |
fcb0ee6a SN |
2174 | } |
2175 | /* | |
2176 | * Assign empty clock ops for consumers that might still hold | |
2177 | * a reference to this clock. | |
2178 | */ | |
2179 | flags = clk_enable_lock(); | |
2180 | clk->ops = &clk_nodrv_ops; | |
2181 | clk_enable_unlock(flags); | |
2182 | ||
2183 | if (!hlist_empty(&clk->children)) { | |
2184 | struct clk *child; | |
874f224c | 2185 | struct hlist_node *t; |
fcb0ee6a SN |
2186 | |
2187 | /* Reparent all children to the orphan list. */ | |
874f224c | 2188 | hlist_for_each_entry_safe(child, t, &clk->children, child_node) |
fcb0ee6a SN |
2189 | clk_set_parent(child, NULL); |
2190 | } | |
2191 | ||
fcb0ee6a SN |
2192 | hlist_del_init(&clk->child_node); |
2193 | ||
2194 | if (clk->prepare_count) | |
2195 | pr_warn("%s: unregistering prepared clock: %s\n", | |
2196 | __func__, clk->name); | |
fcb0ee6a | 2197 | kref_put(&clk->ref, __clk_release); |
6314b679 | 2198 | |
fcb0ee6a SN |
2199 | clk_prepare_unlock(); |
2200 | } | |
1df5c939 MB |
2201 | EXPORT_SYMBOL_GPL(clk_unregister); |
2202 | ||
46c8773a SB |
2203 | static void devm_clk_release(struct device *dev, void *res) |
2204 | { | |
293ba3b4 | 2205 | clk_unregister(*(struct clk **)res); |
46c8773a SB |
2206 | } |
2207 | ||
2208 | /** | |
2209 | * devm_clk_register - resource managed clk_register() | |
2210 | * @dev: device that is registering this clock | |
2211 | * @hw: link to hardware-specific clock data | |
2212 | * | |
2213 | * Managed clk_register(). Clocks returned from this function are | |
2214 | * automatically clk_unregister()ed on driver detach. See clk_register() for | |
2215 | * more information. | |
2216 | */ | |
2217 | struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) | |
2218 | { | |
2219 | struct clk *clk; | |
293ba3b4 | 2220 | struct clk **clkp; |
46c8773a | 2221 | |
293ba3b4 SB |
2222 | clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL); |
2223 | if (!clkp) | |
46c8773a SB |
2224 | return ERR_PTR(-ENOMEM); |
2225 | ||
293ba3b4 SB |
2226 | clk = clk_register(dev, hw); |
2227 | if (!IS_ERR(clk)) { | |
2228 | *clkp = clk; | |
2229 | devres_add(dev, clkp); | |
46c8773a | 2230 | } else { |
293ba3b4 | 2231 | devres_free(clkp); |
46c8773a SB |
2232 | } |
2233 | ||
2234 | return clk; | |
2235 | } | |
2236 | EXPORT_SYMBOL_GPL(devm_clk_register); | |
2237 | ||
2238 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
2239 | { | |
2240 | struct clk *c = res; | |
2241 | if (WARN_ON(!c)) | |
2242 | return 0; | |
2243 | return c == data; | |
2244 | } | |
2245 | ||
2246 | /** | |
2247 | * devm_clk_unregister - resource managed clk_unregister() | |
2248 | * @clk: clock to unregister | |
2249 | * | |
2250 | * Deallocate a clock allocated with devm_clk_register(). Normally | |
2251 | * this function will not need to be called and the resource management | |
2252 | * code will ensure that the resource is freed. | |
2253 | */ | |
2254 | void devm_clk_unregister(struct device *dev, struct clk *clk) | |
2255 | { | |
2256 | WARN_ON(devres_release(dev, devm_clk_release, devm_clk_match, clk)); | |
2257 | } | |
2258 | EXPORT_SYMBOL_GPL(devm_clk_unregister); | |
2259 | ||
ac2df527 SN |
2260 | /* |
2261 | * clkdev helpers | |
2262 | */ | |
2263 | int __clk_get(struct clk *clk) | |
2264 | { | |
00efcb1c SN |
2265 | if (clk) { |
2266 | if (!try_module_get(clk->owner)) | |
2267 | return 0; | |
ac2df527 | 2268 | |
00efcb1c SN |
2269 | kref_get(&clk->ref); |
2270 | } | |
ac2df527 SN |
2271 | return 1; |
2272 | } | |
2273 | ||
2274 | void __clk_put(struct clk *clk) | |
2275 | { | |
00efcb1c | 2276 | if (!clk || WARN_ON_ONCE(IS_ERR(clk))) |
ac2df527 SN |
2277 | return; |
2278 | ||
fcb0ee6a SN |
2279 | clk_prepare_lock(); |
2280 | kref_put(&clk->ref, __clk_release); | |
2281 | clk_prepare_unlock(); | |
2282 | ||
00efcb1c | 2283 | module_put(clk->owner); |
ac2df527 SN |
2284 | } |
2285 | ||
b2476490 MT |
2286 | /*** clk rate change notifiers ***/ |
2287 | ||
2288 | /** | |
2289 | * clk_notifier_register - add a clk rate change notifier | |
2290 | * @clk: struct clk * to watch | |
2291 | * @nb: struct notifier_block * with callback info | |
2292 | * | |
2293 | * Request notification when clk's rate changes. This uses an SRCU | |
2294 | * notifier because we want it to block and notifier unregistrations are | |
2295 | * uncommon. The callbacks associated with the notifier must not | |
2296 | * re-enter into the clk framework by calling any top-level clk APIs; | |
2297 | * this will cause a nested prepare_lock mutex. | |
2298 | * | |
5324fda7 SB |
2299 | * In all notification cases cases (pre, post and abort rate change) the |
2300 | * original clock rate is passed to the callback via struct | |
2301 | * clk_notifier_data.old_rate and the new frequency is passed via struct | |
b2476490 MT |
2302 | * clk_notifier_data.new_rate. |
2303 | * | |
b2476490 MT |
2304 | * clk_notifier_register() must be called from non-atomic context. |
2305 | * Returns -EINVAL if called with null arguments, -ENOMEM upon | |
2306 | * allocation failure; otherwise, passes along the return value of | |
2307 | * srcu_notifier_chain_register(). | |
2308 | */ | |
2309 | int clk_notifier_register(struct clk *clk, struct notifier_block *nb) | |
2310 | { | |
2311 | struct clk_notifier *cn; | |
2312 | int ret = -ENOMEM; | |
2313 | ||
2314 | if (!clk || !nb) | |
2315 | return -EINVAL; | |
2316 | ||
eab89f69 | 2317 | clk_prepare_lock(); |
b2476490 MT |
2318 | |
2319 | /* search the list of notifiers for this clk */ | |
2320 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2321 | if (cn->clk == clk) | |
2322 | break; | |
2323 | ||
2324 | /* if clk wasn't in the notifier list, allocate new clk_notifier */ | |
2325 | if (cn->clk != clk) { | |
2326 | cn = kzalloc(sizeof(struct clk_notifier), GFP_KERNEL); | |
2327 | if (!cn) | |
2328 | goto out; | |
2329 | ||
2330 | cn->clk = clk; | |
2331 | srcu_init_notifier_head(&cn->notifier_head); | |
2332 | ||
2333 | list_add(&cn->node, &clk_notifier_list); | |
2334 | } | |
2335 | ||
2336 | ret = srcu_notifier_chain_register(&cn->notifier_head, nb); | |
2337 | ||
2338 | clk->notifier_count++; | |
2339 | ||
2340 | out: | |
eab89f69 | 2341 | clk_prepare_unlock(); |
b2476490 MT |
2342 | |
2343 | return ret; | |
2344 | } | |
2345 | EXPORT_SYMBOL_GPL(clk_notifier_register); | |
2346 | ||
2347 | /** | |
2348 | * clk_notifier_unregister - remove a clk rate change notifier | |
2349 | * @clk: struct clk * | |
2350 | * @nb: struct notifier_block * with callback info | |
2351 | * | |
2352 | * Request no further notification for changes to 'clk' and frees memory | |
2353 | * allocated in clk_notifier_register. | |
2354 | * | |
2355 | * Returns -EINVAL if called with null arguments; otherwise, passes | |
2356 | * along the return value of srcu_notifier_chain_unregister(). | |
2357 | */ | |
2358 | int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb) | |
2359 | { | |
2360 | struct clk_notifier *cn = NULL; | |
2361 | int ret = -EINVAL; | |
2362 | ||
2363 | if (!clk || !nb) | |
2364 | return -EINVAL; | |
2365 | ||
eab89f69 | 2366 | clk_prepare_lock(); |
b2476490 MT |
2367 | |
2368 | list_for_each_entry(cn, &clk_notifier_list, node) | |
2369 | if (cn->clk == clk) | |
2370 | break; | |
2371 | ||
2372 | if (cn->clk == clk) { | |
2373 | ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); | |
2374 | ||
2375 | clk->notifier_count--; | |
2376 | ||
2377 | /* XXX the notifier code should handle this better */ | |
2378 | if (!cn->notifier_head.head) { | |
2379 | srcu_cleanup_notifier_head(&cn->notifier_head); | |
72b5322f | 2380 | list_del(&cn->node); |
b2476490 MT |
2381 | kfree(cn); |
2382 | } | |
2383 | ||
2384 | } else { | |
2385 | ret = -ENOENT; | |
2386 | } | |
2387 | ||
eab89f69 | 2388 | clk_prepare_unlock(); |
b2476490 MT |
2389 | |
2390 | return ret; | |
2391 | } | |
2392 | EXPORT_SYMBOL_GPL(clk_notifier_unregister); | |
766e6a4e GL |
2393 | |
2394 | #ifdef CONFIG_OF | |
2395 | /** | |
2396 | * struct of_clk_provider - Clock provider registration structure | |
2397 | * @link: Entry in global list of clock providers | |
2398 | * @node: Pointer to device tree node of clock provider | |
2399 | * @get: Get clock callback. Returns NULL or a struct clk for the | |
2400 | * given clock specifier | |
2401 | * @data: context pointer to be passed into @get callback | |
2402 | */ | |
2403 | struct of_clk_provider { | |
2404 | struct list_head link; | |
2405 | ||
2406 | struct device_node *node; | |
2407 | struct clk *(*get)(struct of_phandle_args *clkspec, void *data); | |
2408 | void *data; | |
2409 | }; | |
2410 | ||
f2f6c255 PG |
2411 | static const struct of_device_id __clk_of_table_sentinel |
2412 | __used __section(__clk_of_table_end); | |
2413 | ||
766e6a4e | 2414 | static LIST_HEAD(of_clk_providers); |
d6782c26 SN |
2415 | static DEFINE_MUTEX(of_clk_mutex); |
2416 | ||
2417 | /* of_clk_provider list locking helpers */ | |
2418 | void of_clk_lock(void) | |
2419 | { | |
2420 | mutex_lock(&of_clk_mutex); | |
2421 | } | |
2422 | ||
2423 | void of_clk_unlock(void) | |
2424 | { | |
2425 | mutex_unlock(&of_clk_mutex); | |
2426 | } | |
766e6a4e GL |
2427 | |
2428 | struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, | |
2429 | void *data) | |
2430 | { | |
2431 | return data; | |
2432 | } | |
2433 | EXPORT_SYMBOL_GPL(of_clk_src_simple_get); | |
2434 | ||
494bfec9 SG |
2435 | struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data) |
2436 | { | |
2437 | struct clk_onecell_data *clk_data = data; | |
2438 | unsigned int idx = clkspec->args[0]; | |
2439 | ||
2440 | if (idx >= clk_data->clk_num) { | |
2441 | pr_err("%s: invalid clock index %d\n", __func__, idx); | |
2442 | return ERR_PTR(-EINVAL); | |
2443 | } | |
2444 | ||
2445 | return clk_data->clks[idx]; | |
2446 | } | |
2447 | EXPORT_SYMBOL_GPL(of_clk_src_onecell_get); | |
2448 | ||
766e6a4e GL |
2449 | /** |
2450 | * of_clk_add_provider() - Register a clock provider for a node | |
2451 | * @np: Device node pointer associated with clock provider | |
2452 | * @clk_src_get: callback for decoding clock | |
2453 | * @data: context pointer for @clk_src_get callback. | |
2454 | */ | |
2455 | int of_clk_add_provider(struct device_node *np, | |
2456 | struct clk *(*clk_src_get)(struct of_phandle_args *clkspec, | |
2457 | void *data), | |
2458 | void *data) | |
2459 | { | |
2460 | struct of_clk_provider *cp; | |
86be408b | 2461 | int ret; |
766e6a4e GL |
2462 | |
2463 | cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); | |
2464 | if (!cp) | |
2465 | return -ENOMEM; | |
2466 | ||
2467 | cp->node = of_node_get(np); | |
2468 | cp->data = data; | |
2469 | cp->get = clk_src_get; | |
2470 | ||
d6782c26 | 2471 | mutex_lock(&of_clk_mutex); |
766e6a4e | 2472 | list_add(&cp->link, &of_clk_providers); |
d6782c26 | 2473 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2474 | pr_debug("Added clock from %s\n", np->full_name); |
2475 | ||
86be408b SN |
2476 | ret = of_clk_set_defaults(np, true); |
2477 | if (ret < 0) | |
2478 | of_clk_del_provider(np); | |
2479 | ||
2480 | return ret; | |
766e6a4e GL |
2481 | } |
2482 | EXPORT_SYMBOL_GPL(of_clk_add_provider); | |
2483 | ||
2484 | /** | |
2485 | * of_clk_del_provider() - Remove a previously registered clock provider | |
2486 | * @np: Device node pointer associated with clock provider | |
2487 | */ | |
2488 | void of_clk_del_provider(struct device_node *np) | |
2489 | { | |
2490 | struct of_clk_provider *cp; | |
2491 | ||
d6782c26 | 2492 | mutex_lock(&of_clk_mutex); |
766e6a4e GL |
2493 | list_for_each_entry(cp, &of_clk_providers, link) { |
2494 | if (cp->node == np) { | |
2495 | list_del(&cp->link); | |
2496 | of_node_put(cp->node); | |
2497 | kfree(cp); | |
2498 | break; | |
2499 | } | |
2500 | } | |
d6782c26 | 2501 | mutex_unlock(&of_clk_mutex); |
766e6a4e GL |
2502 | } |
2503 | EXPORT_SYMBOL_GPL(of_clk_del_provider); | |
2504 | ||
d6782c26 | 2505 | struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) |
766e6a4e GL |
2506 | { |
2507 | struct of_clk_provider *provider; | |
a34cd466 | 2508 | struct clk *clk = ERR_PTR(-EPROBE_DEFER); |
766e6a4e GL |
2509 | |
2510 | /* Check if we have such a provider in our array */ | |
766e6a4e GL |
2511 | list_for_each_entry(provider, &of_clk_providers, link) { |
2512 | if (provider->node == clkspec->np) | |
2513 | clk = provider->get(clkspec, provider->data); | |
2514 | if (!IS_ERR(clk)) | |
2515 | break; | |
2516 | } | |
d6782c26 SN |
2517 | |
2518 | return clk; | |
2519 | } | |
2520 | ||
2521 | struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) | |
2522 | { | |
2523 | struct clk *clk; | |
2524 | ||
2525 | mutex_lock(&of_clk_mutex); | |
2526 | clk = __of_clk_get_from_provider(clkspec); | |
2527 | mutex_unlock(&of_clk_mutex); | |
766e6a4e GL |
2528 | |
2529 | return clk; | |
2530 | } | |
2531 | ||
f6102742 MT |
2532 | int of_clk_get_parent_count(struct device_node *np) |
2533 | { | |
2534 | return of_count_phandle_with_args(np, "clocks", "#clock-cells"); | |
2535 | } | |
2536 | EXPORT_SYMBOL_GPL(of_clk_get_parent_count); | |
2537 | ||
766e6a4e GL |
2538 | const char *of_clk_get_parent_name(struct device_node *np, int index) |
2539 | { | |
2540 | struct of_phandle_args clkspec; | |
7a0fc1a3 | 2541 | struct property *prop; |
766e6a4e | 2542 | const char *clk_name; |
7a0fc1a3 BD |
2543 | const __be32 *vp; |
2544 | u32 pv; | |
766e6a4e | 2545 | int rc; |
7a0fc1a3 | 2546 | int count; |
766e6a4e GL |
2547 | |
2548 | if (index < 0) | |
2549 | return NULL; | |
2550 | ||
2551 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
2552 | &clkspec); | |
2553 | if (rc) | |
2554 | return NULL; | |
2555 | ||
7a0fc1a3 BD |
2556 | index = clkspec.args_count ? clkspec.args[0] : 0; |
2557 | count = 0; | |
2558 | ||
2559 | /* if there is an indices property, use it to transfer the index | |
2560 | * specified into an array offset for the clock-output-names property. | |
2561 | */ | |
2562 | of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) { | |
2563 | if (index == pv) { | |
2564 | index = count; | |
2565 | break; | |
2566 | } | |
2567 | count++; | |
2568 | } | |
2569 | ||
766e6a4e | 2570 | if (of_property_read_string_index(clkspec.np, "clock-output-names", |
7a0fc1a3 | 2571 | index, |
766e6a4e GL |
2572 | &clk_name) < 0) |
2573 | clk_name = clkspec.np->name; | |
2574 | ||
2575 | of_node_put(clkspec.np); | |
2576 | return clk_name; | |
2577 | } | |
2578 | EXPORT_SYMBOL_GPL(of_clk_get_parent_name); | |
2579 | ||
1771b10d GC |
2580 | struct clock_provider { |
2581 | of_clk_init_cb_t clk_init_cb; | |
2582 | struct device_node *np; | |
2583 | struct list_head node; | |
2584 | }; | |
2585 | ||
2586 | static LIST_HEAD(clk_provider_list); | |
2587 | ||
2588 | /* | |
2589 | * This function looks for a parent clock. If there is one, then it | |
2590 | * checks that the provider for this parent clock was initialized, in | |
2591 | * this case the parent clock will be ready. | |
2592 | */ | |
2593 | static int parent_ready(struct device_node *np) | |
2594 | { | |
2595 | int i = 0; | |
2596 | ||
2597 | while (true) { | |
2598 | struct clk *clk = of_clk_get(np, i); | |
2599 | ||
2600 | /* this parent is ready we can check the next one */ | |
2601 | if (!IS_ERR(clk)) { | |
2602 | clk_put(clk); | |
2603 | i++; | |
2604 | continue; | |
2605 | } | |
2606 | ||
2607 | /* at least one parent is not ready, we exit now */ | |
2608 | if (PTR_ERR(clk) == -EPROBE_DEFER) | |
2609 | return 0; | |
2610 | ||
2611 | /* | |
2612 | * Here we make assumption that the device tree is | |
2613 | * written correctly. So an error means that there is | |
2614 | * no more parent. As we didn't exit yet, then the | |
2615 | * previous parent are ready. If there is no clock | |
2616 | * parent, no need to wait for them, then we can | |
2617 | * consider their absence as being ready | |
2618 | */ | |
2619 | return 1; | |
2620 | } | |
2621 | } | |
2622 | ||
766e6a4e GL |
2623 | /** |
2624 | * of_clk_init() - Scan and init clock providers from the DT | |
2625 | * @matches: array of compatible values and init functions for providers. | |
2626 | * | |
1771b10d | 2627 | * This function scans the device tree for matching clock providers |
e5ca8fb4 | 2628 | * and calls their initialization functions. It also does it by trying |
1771b10d | 2629 | * to follow the dependencies. |
766e6a4e GL |
2630 | */ |
2631 | void __init of_clk_init(const struct of_device_id *matches) | |
2632 | { | |
7f7ed584 | 2633 | const struct of_device_id *match; |
766e6a4e | 2634 | struct device_node *np; |
1771b10d GC |
2635 | struct clock_provider *clk_provider, *next; |
2636 | bool is_init_done; | |
2637 | bool force = false; | |
766e6a4e | 2638 | |
f2f6c255 | 2639 | if (!matches) |
819b4861 | 2640 | matches = &__clk_of_table; |
f2f6c255 | 2641 | |
1771b10d | 2642 | /* First prepare the list of the clocks providers */ |
7f7ed584 | 2643 | for_each_matching_node_and_match(np, matches, &match) { |
1771b10d GC |
2644 | struct clock_provider *parent = |
2645 | kzalloc(sizeof(struct clock_provider), GFP_KERNEL); | |
2646 | ||
2647 | parent->clk_init_cb = match->data; | |
2648 | parent->np = np; | |
3f6d439f | 2649 | list_add_tail(&parent->node, &clk_provider_list); |
1771b10d GC |
2650 | } |
2651 | ||
2652 | while (!list_empty(&clk_provider_list)) { | |
2653 | is_init_done = false; | |
2654 | list_for_each_entry_safe(clk_provider, next, | |
2655 | &clk_provider_list, node) { | |
2656 | if (force || parent_ready(clk_provider->np)) { | |
86be408b | 2657 | |
1771b10d | 2658 | clk_provider->clk_init_cb(clk_provider->np); |
86be408b SN |
2659 | of_clk_set_defaults(clk_provider->np, true); |
2660 | ||
1771b10d GC |
2661 | list_del(&clk_provider->node); |
2662 | kfree(clk_provider); | |
2663 | is_init_done = true; | |
2664 | } | |
2665 | } | |
2666 | ||
2667 | /* | |
e5ca8fb4 | 2668 | * We didn't manage to initialize any of the |
1771b10d GC |
2669 | * remaining providers during the last loop, so now we |
2670 | * initialize all the remaining ones unconditionally | |
2671 | * in case the clock parent was not mandatory | |
2672 | */ | |
2673 | if (!is_init_done) | |
2674 | force = true; | |
766e6a4e GL |
2675 | } |
2676 | } | |
2677 | #endif |