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8b5ee113 MD |
1 | /* |
2 | * drivers/sh/clk.c - SuperH clock framework | |
3 | * | |
960bc368 | 4 | * Copyright (C) 2005 - 2010 Paul Mundt |
8b5ee113 MD |
5 | * |
6 | * This clock framework is derived from the OMAP version by: | |
7 | * | |
8 | * Copyright (C) 2004 - 2008 Nokia Corporation | |
9 | * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com> | |
10 | * | |
11 | * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com> | |
12 | * | |
13 | * This file is subject to the terms and conditions of the GNU General Public | |
14 | * License. See the file "COPYING" in the main directory of this archive | |
15 | * for more details. | |
16 | */ | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/mutex.h> | |
21 | #include <linux/list.h> | |
22 | #include <linux/kobject.h> | |
23 | #include <linux/sysdev.h> | |
24 | #include <linux/seq_file.h> | |
25 | #include <linux/err.h> | |
26 | #include <linux/platform_device.h> | |
27 | #include <linux/debugfs.h> | |
28 | #include <linux/cpufreq.h> | |
29 | #include <linux/clk.h> | |
30 | #include <linux/sh_clk.h> | |
31 | ||
32 | static LIST_HEAD(clock_list); | |
33 | static DEFINE_SPINLOCK(clock_lock); | |
34 | static DEFINE_MUTEX(clock_list_sem); | |
35 | ||
36 | void clk_rate_table_build(struct clk *clk, | |
37 | struct cpufreq_frequency_table *freq_table, | |
38 | int nr_freqs, | |
39 | struct clk_div_mult_table *src_table, | |
40 | unsigned long *bitmap) | |
41 | { | |
42 | unsigned long mult, div; | |
43 | unsigned long freq; | |
44 | int i; | |
45 | ||
46 | for (i = 0; i < nr_freqs; i++) { | |
47 | div = 1; | |
48 | mult = 1; | |
49 | ||
50 | if (src_table->divisors && i < src_table->nr_divisors) | |
51 | div = src_table->divisors[i]; | |
52 | ||
53 | if (src_table->multipliers && i < src_table->nr_multipliers) | |
54 | mult = src_table->multipliers[i]; | |
55 | ||
56 | if (!div || !mult || (bitmap && !test_bit(i, bitmap))) | |
57 | freq = CPUFREQ_ENTRY_INVALID; | |
58 | else | |
59 | freq = clk->parent->rate * mult / div; | |
60 | ||
61 | freq_table[i].index = i; | |
62 | freq_table[i].frequency = freq; | |
63 | } | |
64 | ||
65 | /* Termination entry */ | |
66 | freq_table[i].index = i; | |
67 | freq_table[i].frequency = CPUFREQ_TABLE_END; | |
68 | } | |
69 | ||
70 | long clk_rate_table_round(struct clk *clk, | |
71 | struct cpufreq_frequency_table *freq_table, | |
72 | unsigned long rate) | |
73 | { | |
74 | unsigned long rate_error, rate_error_prev = ~0UL; | |
75 | unsigned long rate_best_fit = rate; | |
960bc368 | 76 | unsigned long highest, lowest; |
8b5ee113 MD |
77 | int i; |
78 | ||
960bc368 PM |
79 | highest = 0; |
80 | lowest = ~0UL; | |
81 | ||
8b5ee113 MD |
82 | for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) { |
83 | unsigned long freq = freq_table[i].frequency; | |
84 | ||
85 | if (freq == CPUFREQ_ENTRY_INVALID) | |
86 | continue; | |
87 | ||
960bc368 PM |
88 | if (freq > highest) |
89 | highest = freq; | |
90 | if (freq < lowest) | |
91 | lowest = freq; | |
92 | ||
8b5ee113 MD |
93 | rate_error = abs(freq - rate); |
94 | if (rate_error < rate_error_prev) { | |
95 | rate_best_fit = freq; | |
96 | rate_error_prev = rate_error; | |
97 | } | |
98 | ||
99 | if (rate_error == 0) | |
100 | break; | |
101 | } | |
102 | ||
960bc368 PM |
103 | if (rate >= highest) |
104 | rate_best_fit = highest; | |
105 | if (rate <= lowest) | |
106 | rate_best_fit = lowest; | |
107 | ||
8b5ee113 MD |
108 | return rate_best_fit; |
109 | } | |
110 | ||
111 | int clk_rate_table_find(struct clk *clk, | |
112 | struct cpufreq_frequency_table *freq_table, | |
113 | unsigned long rate) | |
114 | { | |
115 | int i; | |
116 | ||
117 | for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) { | |
118 | unsigned long freq = freq_table[i].frequency; | |
119 | ||
120 | if (freq == CPUFREQ_ENTRY_INVALID) | |
121 | continue; | |
122 | ||
123 | if (freq == rate) | |
124 | return i; | |
125 | } | |
126 | ||
127 | return -ENOENT; | |
128 | } | |
129 | ||
130 | /* Used for clocks that always have same value as the parent clock */ | |
131 | unsigned long followparent_recalc(struct clk *clk) | |
132 | { | |
133 | return clk->parent ? clk->parent->rate : 0; | |
134 | } | |
135 | ||
136 | int clk_reparent(struct clk *child, struct clk *parent) | |
137 | { | |
138 | list_del_init(&child->sibling); | |
139 | if (parent) | |
140 | list_add(&child->sibling, &parent->children); | |
141 | child->parent = parent; | |
142 | ||
143 | /* now do the debugfs renaming to reattach the child | |
144 | to the proper parent */ | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | /* Propagate rate to children */ | |
150 | void propagate_rate(struct clk *tclk) | |
151 | { | |
152 | struct clk *clkp; | |
153 | ||
154 | list_for_each_entry(clkp, &tclk->children, sibling) { | |
155 | if (clkp->ops && clkp->ops->recalc) | |
156 | clkp->rate = clkp->ops->recalc(clkp); | |
157 | ||
158 | propagate_rate(clkp); | |
159 | } | |
160 | } | |
161 | ||
162 | static void __clk_disable(struct clk *clk) | |
163 | { | |
69395396 MD |
164 | if (WARN(!clk->usecount, "Trying to disable clock %p with 0 usecount\n", |
165 | clk)) | |
8b5ee113 | 166 | return; |
8b5ee113 MD |
167 | |
168 | if (!(--clk->usecount)) { | |
169 | if (likely(clk->ops && clk->ops->disable)) | |
170 | clk->ops->disable(clk); | |
171 | if (likely(clk->parent)) | |
172 | __clk_disable(clk->parent); | |
173 | } | |
174 | } | |
175 | ||
176 | void clk_disable(struct clk *clk) | |
177 | { | |
178 | unsigned long flags; | |
179 | ||
180 | if (!clk) | |
181 | return; | |
182 | ||
183 | spin_lock_irqsave(&clock_lock, flags); | |
184 | __clk_disable(clk); | |
185 | spin_unlock_irqrestore(&clock_lock, flags); | |
186 | } | |
187 | EXPORT_SYMBOL_GPL(clk_disable); | |
188 | ||
189 | static int __clk_enable(struct clk *clk) | |
190 | { | |
191 | int ret = 0; | |
192 | ||
193 | if (clk->usecount++ == 0) { | |
194 | if (clk->parent) { | |
195 | ret = __clk_enable(clk->parent); | |
196 | if (unlikely(ret)) | |
197 | goto err; | |
198 | } | |
199 | ||
200 | if (clk->ops && clk->ops->enable) { | |
201 | ret = clk->ops->enable(clk); | |
202 | if (ret) { | |
203 | if (clk->parent) | |
204 | __clk_disable(clk->parent); | |
205 | goto err; | |
206 | } | |
207 | } | |
208 | } | |
209 | ||
210 | return ret; | |
211 | err: | |
212 | clk->usecount--; | |
213 | return ret; | |
214 | } | |
215 | ||
216 | int clk_enable(struct clk *clk) | |
217 | { | |
218 | unsigned long flags; | |
219 | int ret; | |
220 | ||
221 | if (!clk) | |
222 | return -EINVAL; | |
223 | ||
224 | spin_lock_irqsave(&clock_lock, flags); | |
225 | ret = __clk_enable(clk); | |
226 | spin_unlock_irqrestore(&clock_lock, flags); | |
227 | ||
228 | return ret; | |
229 | } | |
230 | EXPORT_SYMBOL_GPL(clk_enable); | |
231 | ||
232 | static LIST_HEAD(root_clks); | |
233 | ||
234 | /** | |
235 | * recalculate_root_clocks - recalculate and propagate all root clocks | |
236 | * | |
237 | * Recalculates all root clocks (clocks with no parent), which if the | |
238 | * clock's .recalc is set correctly, should also propagate their rates. | |
239 | * Called at init. | |
240 | */ | |
241 | void recalculate_root_clocks(void) | |
242 | { | |
243 | struct clk *clkp; | |
244 | ||
245 | list_for_each_entry(clkp, &root_clks, sibling) { | |
246 | if (clkp->ops && clkp->ops->recalc) | |
247 | clkp->rate = clkp->ops->recalc(clkp); | |
248 | propagate_rate(clkp); | |
249 | } | |
250 | } | |
251 | ||
252 | int clk_register(struct clk *clk) | |
253 | { | |
254 | if (clk == NULL || IS_ERR(clk)) | |
255 | return -EINVAL; | |
256 | ||
257 | /* | |
258 | * trap out already registered clocks | |
259 | */ | |
260 | if (clk->node.next || clk->node.prev) | |
261 | return 0; | |
262 | ||
263 | mutex_lock(&clock_list_sem); | |
264 | ||
265 | INIT_LIST_HEAD(&clk->children); | |
266 | clk->usecount = 0; | |
267 | ||
268 | if (clk->parent) | |
269 | list_add(&clk->sibling, &clk->parent->children); | |
270 | else | |
271 | list_add(&clk->sibling, &root_clks); | |
272 | ||
273 | list_add(&clk->node, &clock_list); | |
274 | if (clk->ops && clk->ops->init) | |
275 | clk->ops->init(clk); | |
276 | mutex_unlock(&clock_list_sem); | |
277 | ||
278 | return 0; | |
279 | } | |
280 | EXPORT_SYMBOL_GPL(clk_register); | |
281 | ||
282 | void clk_unregister(struct clk *clk) | |
283 | { | |
284 | mutex_lock(&clock_list_sem); | |
285 | list_del(&clk->sibling); | |
286 | list_del(&clk->node); | |
287 | mutex_unlock(&clock_list_sem); | |
288 | } | |
289 | EXPORT_SYMBOL_GPL(clk_unregister); | |
290 | ||
291 | void clk_enable_init_clocks(void) | |
292 | { | |
293 | struct clk *clkp; | |
294 | ||
295 | list_for_each_entry(clkp, &clock_list, node) | |
296 | if (clkp->flags & CLK_ENABLE_ON_INIT) | |
297 | clk_enable(clkp); | |
298 | } | |
299 | ||
300 | unsigned long clk_get_rate(struct clk *clk) | |
301 | { | |
302 | return clk->rate; | |
303 | } | |
304 | EXPORT_SYMBOL_GPL(clk_get_rate); | |
305 | ||
306 | int clk_set_rate(struct clk *clk, unsigned long rate) | |
307 | { | |
308 | return clk_set_rate_ex(clk, rate, 0); | |
309 | } | |
310 | EXPORT_SYMBOL_GPL(clk_set_rate); | |
311 | ||
312 | int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id) | |
313 | { | |
314 | int ret = -EOPNOTSUPP; | |
315 | unsigned long flags; | |
316 | ||
317 | spin_lock_irqsave(&clock_lock, flags); | |
318 | ||
319 | if (likely(clk->ops && clk->ops->set_rate)) { | |
320 | ret = clk->ops->set_rate(clk, rate, algo_id); | |
321 | if (ret != 0) | |
322 | goto out_unlock; | |
323 | } else { | |
324 | clk->rate = rate; | |
325 | ret = 0; | |
326 | } | |
327 | ||
328 | if (clk->ops && clk->ops->recalc) | |
329 | clk->rate = clk->ops->recalc(clk); | |
330 | ||
331 | propagate_rate(clk); | |
332 | ||
333 | out_unlock: | |
334 | spin_unlock_irqrestore(&clock_lock, flags); | |
335 | ||
336 | return ret; | |
337 | } | |
338 | EXPORT_SYMBOL_GPL(clk_set_rate_ex); | |
339 | ||
340 | int clk_set_parent(struct clk *clk, struct clk *parent) | |
341 | { | |
342 | unsigned long flags; | |
343 | int ret = -EINVAL; | |
344 | ||
345 | if (!parent || !clk) | |
346 | return ret; | |
347 | if (clk->parent == parent) | |
348 | return 0; | |
349 | ||
350 | spin_lock_irqsave(&clock_lock, flags); | |
351 | if (clk->usecount == 0) { | |
352 | if (clk->ops->set_parent) | |
353 | ret = clk->ops->set_parent(clk, parent); | |
354 | else | |
355 | ret = clk_reparent(clk, parent); | |
356 | ||
357 | if (ret == 0) { | |
8b5ee113 MD |
358 | if (clk->ops->recalc) |
359 | clk->rate = clk->ops->recalc(clk); | |
69395396 MD |
360 | pr_debug("clock: set parent of %p to %p (new rate %ld)\n", |
361 | clk, clk->parent, clk->rate); | |
8b5ee113 MD |
362 | propagate_rate(clk); |
363 | } | |
364 | } else | |
365 | ret = -EBUSY; | |
366 | spin_unlock_irqrestore(&clock_lock, flags); | |
367 | ||
368 | return ret; | |
369 | } | |
370 | EXPORT_SYMBOL_GPL(clk_set_parent); | |
371 | ||
372 | struct clk *clk_get_parent(struct clk *clk) | |
373 | { | |
374 | return clk->parent; | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(clk_get_parent); | |
377 | ||
378 | long clk_round_rate(struct clk *clk, unsigned long rate) | |
379 | { | |
380 | if (likely(clk->ops && clk->ops->round_rate)) { | |
381 | unsigned long flags, rounded; | |
382 | ||
383 | spin_lock_irqsave(&clock_lock, flags); | |
384 | rounded = clk->ops->round_rate(clk, rate); | |
385 | spin_unlock_irqrestore(&clock_lock, flags); | |
386 | ||
387 | return rounded; | |
388 | } | |
389 | ||
390 | return clk_get_rate(clk); | |
391 | } | |
392 | EXPORT_SYMBOL_GPL(clk_round_rate); | |
393 | ||
394 | #ifdef CONFIG_PM | |
395 | static int clks_sysdev_suspend(struct sys_device *dev, pm_message_t state) | |
396 | { | |
397 | static pm_message_t prev_state; | |
398 | struct clk *clkp; | |
399 | ||
400 | switch (state.event) { | |
401 | case PM_EVENT_ON: | |
402 | /* Resumeing from hibernation */ | |
403 | if (prev_state.event != PM_EVENT_FREEZE) | |
404 | break; | |
405 | ||
406 | list_for_each_entry(clkp, &clock_list, node) { | |
407 | if (likely(clkp->ops)) { | |
408 | unsigned long rate = clkp->rate; | |
409 | ||
410 | if (likely(clkp->ops->set_parent)) | |
411 | clkp->ops->set_parent(clkp, | |
412 | clkp->parent); | |
413 | if (likely(clkp->ops->set_rate)) | |
414 | clkp->ops->set_rate(clkp, | |
415 | rate, NO_CHANGE); | |
416 | else if (likely(clkp->ops->recalc)) | |
417 | clkp->rate = clkp->ops->recalc(clkp); | |
418 | } | |
419 | } | |
420 | break; | |
421 | case PM_EVENT_FREEZE: | |
422 | break; | |
423 | case PM_EVENT_SUSPEND: | |
424 | break; | |
425 | } | |
426 | ||
427 | prev_state = state; | |
428 | return 0; | |
429 | } | |
430 | ||
431 | static int clks_sysdev_resume(struct sys_device *dev) | |
432 | { | |
433 | return clks_sysdev_suspend(dev, PMSG_ON); | |
434 | } | |
435 | ||
436 | static struct sysdev_class clks_sysdev_class = { | |
437 | .name = "clks", | |
438 | }; | |
439 | ||
440 | static struct sysdev_driver clks_sysdev_driver = { | |
441 | .suspend = clks_sysdev_suspend, | |
442 | .resume = clks_sysdev_resume, | |
443 | }; | |
444 | ||
445 | static struct sys_device clks_sysdev_dev = { | |
446 | .cls = &clks_sysdev_class, | |
447 | }; | |
448 | ||
449 | static int __init clk_sysdev_init(void) | |
450 | { | |
451 | sysdev_class_register(&clks_sysdev_class); | |
452 | sysdev_driver_register(&clks_sysdev_class, &clks_sysdev_driver); | |
453 | sysdev_register(&clks_sysdev_dev); | |
454 | ||
455 | return 0; | |
456 | } | |
457 | subsys_initcall(clk_sysdev_init); | |
458 | #endif | |
459 | ||
460 | /* | |
461 | * debugfs support to trace clock tree hierarchy and attributes | |
462 | */ | |
463 | static struct dentry *clk_debugfs_root; | |
464 | ||
465 | static int clk_debugfs_register_one(struct clk *c) | |
466 | { | |
467 | int err; | |
468 | struct dentry *d, *child, *child_tmp; | |
469 | struct clk *pa = c->parent; | |
470 | char s[255]; | |
471 | char *p = s; | |
472 | ||
69395396 | 473 | p += sprintf(p, "%p", c); |
8b5ee113 MD |
474 | d = debugfs_create_dir(s, pa ? pa->dentry : clk_debugfs_root); |
475 | if (!d) | |
476 | return -ENOMEM; | |
477 | c->dentry = d; | |
478 | ||
479 | d = debugfs_create_u8("usecount", S_IRUGO, c->dentry, (u8 *)&c->usecount); | |
480 | if (!d) { | |
481 | err = -ENOMEM; | |
482 | goto err_out; | |
483 | } | |
484 | d = debugfs_create_u32("rate", S_IRUGO, c->dentry, (u32 *)&c->rate); | |
485 | if (!d) { | |
486 | err = -ENOMEM; | |
487 | goto err_out; | |
488 | } | |
489 | d = debugfs_create_x32("flags", S_IRUGO, c->dentry, (u32 *)&c->flags); | |
490 | if (!d) { | |
491 | err = -ENOMEM; | |
492 | goto err_out; | |
493 | } | |
494 | return 0; | |
495 | ||
496 | err_out: | |
497 | d = c->dentry; | |
498 | list_for_each_entry_safe(child, child_tmp, &d->d_subdirs, d_u.d_child) | |
499 | debugfs_remove(child); | |
500 | debugfs_remove(c->dentry); | |
501 | return err; | |
502 | } | |
503 | ||
504 | static int clk_debugfs_register(struct clk *c) | |
505 | { | |
506 | int err; | |
507 | struct clk *pa = c->parent; | |
508 | ||
509 | if (pa && !pa->dentry) { | |
510 | err = clk_debugfs_register(pa); | |
511 | if (err) | |
512 | return err; | |
513 | } | |
514 | ||
69395396 | 515 | if (!c->dentry) { |
8b5ee113 MD |
516 | err = clk_debugfs_register_one(c); |
517 | if (err) | |
518 | return err; | |
519 | } | |
520 | return 0; | |
521 | } | |
522 | ||
523 | static int __init clk_debugfs_init(void) | |
524 | { | |
525 | struct clk *c; | |
526 | struct dentry *d; | |
527 | int err; | |
528 | ||
529 | d = debugfs_create_dir("clock", NULL); | |
530 | if (!d) | |
531 | return -ENOMEM; | |
532 | clk_debugfs_root = d; | |
533 | ||
534 | list_for_each_entry(c, &clock_list, node) { | |
535 | err = clk_debugfs_register(c); | |
536 | if (err) | |
537 | goto err_out; | |
538 | } | |
539 | return 0; | |
540 | err_out: | |
541 | debugfs_remove_recursive(clk_debugfs_root); | |
542 | return err; | |
543 | } | |
544 | late_initcall(clk_debugfs_init); |