switch assorted clock drivers to debugfs_remove_recursive()
[linux-2.6.git] / arch / arm / plat-omap / clock.c
1 /*
2  *  linux/arch/arm/plat-omap/clock.c
3  *
4  *  Copyright (C) 2004 - 2008 Nokia corporation
5  *  Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
6  *
7  *  Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/list.h>
16 #include <linux/errno.h>
17 #include <linux/err.h>
18 #include <linux/string.h>
19 #include <linux/clk.h>
20 #include <linux/mutex.h>
21 #include <linux/cpufreq.h>
22 #include <linux/debugfs.h>
23 #include <linux/io.h>
24
25 #include <plat/clock.h>
26
27 static LIST_HEAD(clocks);
28 static DEFINE_MUTEX(clocks_mutex);
29 static DEFINE_SPINLOCK(clockfw_lock);
30
31 static struct clk_functions *arch_clock;
32
33 /*
34  * Standard clock functions defined in include/linux/clk.h
35  */
36
37 int clk_enable(struct clk *clk)
38 {
39         unsigned long flags;
40         int ret;
41
42         if (clk == NULL || IS_ERR(clk))
43                 return -EINVAL;
44
45         if (!arch_clock || !arch_clock->clk_enable)
46                 return -EINVAL;
47
48         spin_lock_irqsave(&clockfw_lock, flags);
49         ret = arch_clock->clk_enable(clk);
50         spin_unlock_irqrestore(&clockfw_lock, flags);
51
52         return ret;
53 }
54 EXPORT_SYMBOL(clk_enable);
55
56 void clk_disable(struct clk *clk)
57 {
58         unsigned long flags;
59
60         if (clk == NULL || IS_ERR(clk))
61                 return;
62
63         if (!arch_clock || !arch_clock->clk_disable)
64                 return;
65
66         spin_lock_irqsave(&clockfw_lock, flags);
67         if (clk->usecount == 0) {
68                 pr_err("Trying disable clock %s with 0 usecount\n",
69                        clk->name);
70                 WARN_ON(1);
71                 goto out;
72         }
73
74         arch_clock->clk_disable(clk);
75
76 out:
77         spin_unlock_irqrestore(&clockfw_lock, flags);
78 }
79 EXPORT_SYMBOL(clk_disable);
80
81 unsigned long clk_get_rate(struct clk *clk)
82 {
83         unsigned long flags;
84         unsigned long ret;
85
86         if (clk == NULL || IS_ERR(clk))
87                 return 0;
88
89         spin_lock_irqsave(&clockfw_lock, flags);
90         ret = clk->rate;
91         spin_unlock_irqrestore(&clockfw_lock, flags);
92
93         return ret;
94 }
95 EXPORT_SYMBOL(clk_get_rate);
96
97 /*
98  * Optional clock functions defined in include/linux/clk.h
99  */
100
101 long clk_round_rate(struct clk *clk, unsigned long rate)
102 {
103         unsigned long flags;
104         long ret;
105
106         if (clk == NULL || IS_ERR(clk))
107                 return 0;
108
109         if (!arch_clock || !arch_clock->clk_round_rate)
110                 return 0;
111
112         spin_lock_irqsave(&clockfw_lock, flags);
113         ret = arch_clock->clk_round_rate(clk, rate);
114         spin_unlock_irqrestore(&clockfw_lock, flags);
115
116         return ret;
117 }
118 EXPORT_SYMBOL(clk_round_rate);
119
120 int clk_set_rate(struct clk *clk, unsigned long rate)
121 {
122         unsigned long flags;
123         int ret = -EINVAL;
124
125         if (clk == NULL || IS_ERR(clk))
126                 return ret;
127
128         if (!arch_clock || !arch_clock->clk_set_rate)
129                 return ret;
130
131         spin_lock_irqsave(&clockfw_lock, flags);
132         ret = arch_clock->clk_set_rate(clk, rate);
133         if (ret == 0)
134                 propagate_rate(clk);
135         spin_unlock_irqrestore(&clockfw_lock, flags);
136
137         return ret;
138 }
139 EXPORT_SYMBOL(clk_set_rate);
140
141 int clk_set_parent(struct clk *clk, struct clk *parent)
142 {
143         unsigned long flags;
144         int ret = -EINVAL;
145
146         if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
147                 return ret;
148
149         if (!arch_clock || !arch_clock->clk_set_parent)
150                 return ret;
151
152         spin_lock_irqsave(&clockfw_lock, flags);
153         if (clk->usecount == 0) {
154                 ret = arch_clock->clk_set_parent(clk, parent);
155                 if (ret == 0)
156                         propagate_rate(clk);
157         } else
158                 ret = -EBUSY;
159         spin_unlock_irqrestore(&clockfw_lock, flags);
160
161         return ret;
162 }
163 EXPORT_SYMBOL(clk_set_parent);
164
165 struct clk *clk_get_parent(struct clk *clk)
166 {
167         return clk->parent;
168 }
169 EXPORT_SYMBOL(clk_get_parent);
170
171 /*
172  * OMAP specific clock functions shared between omap1 and omap2
173  */
174
175 int __initdata mpurate;
176
177 /*
178  * By default we use the rate set by the bootloader.
179  * You can override this with mpurate= cmdline option.
180  */
181 static int __init omap_clk_setup(char *str)
182 {
183         get_option(&str, &mpurate);
184
185         if (!mpurate)
186                 return 1;
187
188         if (mpurate < 1000)
189                 mpurate *= 1000000;
190
191         return 1;
192 }
193 __setup("mpurate=", omap_clk_setup);
194
195 /* Used for clocks that always have same value as the parent clock */
196 unsigned long followparent_recalc(struct clk *clk)
197 {
198         return clk->parent->rate;
199 }
200
201 /*
202  * Used for clocks that have the same value as the parent clock,
203  * divided by some factor
204  */
205 unsigned long omap_fixed_divisor_recalc(struct clk *clk)
206 {
207         WARN_ON(!clk->fixed_div);
208
209         return clk->parent->rate / clk->fixed_div;
210 }
211
212 void clk_reparent(struct clk *child, struct clk *parent)
213 {
214         list_del_init(&child->sibling);
215         if (parent)
216                 list_add(&child->sibling, &parent->children);
217         child->parent = parent;
218
219         /* now do the debugfs renaming to reattach the child
220            to the proper parent */
221 }
222
223 /* Propagate rate to children */
224 void propagate_rate(struct clk *tclk)
225 {
226         struct clk *clkp;
227
228         list_for_each_entry(clkp, &tclk->children, sibling) {
229                 if (clkp->recalc)
230                         clkp->rate = clkp->recalc(clkp);
231                 propagate_rate(clkp);
232         }
233 }
234
235 static LIST_HEAD(root_clks);
236
237 /**
238  * recalculate_root_clocks - recalculate and propagate all root clocks
239  *
240  * Recalculates all root clocks (clocks with no parent), which if the
241  * clock's .recalc is set correctly, should also propagate their rates.
242  * Called at init.
243  */
244 void recalculate_root_clocks(void)
245 {
246         struct clk *clkp;
247
248         list_for_each_entry(clkp, &root_clks, sibling) {
249                 if (clkp->recalc)
250                         clkp->rate = clkp->recalc(clkp);
251                 propagate_rate(clkp);
252         }
253 }
254
255 /**
256  * clk_preinit - initialize any fields in the struct clk before clk init
257  * @clk: struct clk * to initialize
258  *
259  * Initialize any struct clk fields needed before normal clk initialization
260  * can run.  No return value.
261  */
262 void clk_preinit(struct clk *clk)
263 {
264         INIT_LIST_HEAD(&clk->children);
265 }
266
267 int clk_register(struct clk *clk)
268 {
269         if (clk == NULL || IS_ERR(clk))
270                 return -EINVAL;
271
272         /*
273          * trap out already registered clocks
274          */
275         if (clk->node.next || clk->node.prev)
276                 return 0;
277
278         mutex_lock(&clocks_mutex);
279         if (clk->parent)
280                 list_add(&clk->sibling, &clk->parent->children);
281         else
282                 list_add(&clk->sibling, &root_clks);
283
284         list_add(&clk->node, &clocks);
285         if (clk->init)
286                 clk->init(clk);
287         mutex_unlock(&clocks_mutex);
288
289         return 0;
290 }
291 EXPORT_SYMBOL(clk_register);
292
293 void clk_unregister(struct clk *clk)
294 {
295         if (clk == NULL || IS_ERR(clk))
296                 return;
297
298         mutex_lock(&clocks_mutex);
299         list_del(&clk->sibling);
300         list_del(&clk->node);
301         mutex_unlock(&clocks_mutex);
302 }
303 EXPORT_SYMBOL(clk_unregister);
304
305 void clk_enable_init_clocks(void)
306 {
307         struct clk *clkp;
308
309         list_for_each_entry(clkp, &clocks, node) {
310                 if (clkp->flags & ENABLE_ON_INIT)
311                         clk_enable(clkp);
312         }
313 }
314
315 /**
316  * omap_clk_get_by_name - locate OMAP struct clk by its name
317  * @name: name of the struct clk to locate
318  *
319  * Locate an OMAP struct clk by its name.  Assumes that struct clk
320  * names are unique.  Returns NULL if not found or a pointer to the
321  * struct clk if found.
322  */
323 struct clk *omap_clk_get_by_name(const char *name)
324 {
325         struct clk *c;
326         struct clk *ret = NULL;
327
328         mutex_lock(&clocks_mutex);
329
330         list_for_each_entry(c, &clocks, node) {
331                 if (!strcmp(c->name, name)) {
332                         ret = c;
333                         break;
334                 }
335         }
336
337         mutex_unlock(&clocks_mutex);
338
339         return ret;
340 }
341
342 int omap_clk_enable_autoidle_all(void)
343 {
344         struct clk *c;
345         unsigned long flags;
346
347         spin_lock_irqsave(&clockfw_lock, flags);
348
349         list_for_each_entry(c, &clocks, node)
350                 if (c->ops->allow_idle)
351                         c->ops->allow_idle(c);
352
353         spin_unlock_irqrestore(&clockfw_lock, flags);
354
355         return 0;
356 }
357
358 int omap_clk_disable_autoidle_all(void)
359 {
360         struct clk *c;
361         unsigned long flags;
362
363         spin_lock_irqsave(&clockfw_lock, flags);
364
365         list_for_each_entry(c, &clocks, node)
366                 if (c->ops->deny_idle)
367                         c->ops->deny_idle(c);
368
369         spin_unlock_irqrestore(&clockfw_lock, flags);
370
371         return 0;
372 }
373
374 /*
375  * Low level helpers
376  */
377 static int clkll_enable_null(struct clk *clk)
378 {
379         return 0;
380 }
381
382 static void clkll_disable_null(struct clk *clk)
383 {
384 }
385
386 const struct clkops clkops_null = {
387         .enable         = clkll_enable_null,
388         .disable        = clkll_disable_null,
389 };
390
391 /*
392  * Dummy clock
393  *
394  * Used for clock aliases that are needed on some OMAPs, but not others
395  */
396 struct clk dummy_ck = {
397         .name   = "dummy",
398         .ops    = &clkops_null,
399 };
400
401 #ifdef CONFIG_CPU_FREQ
402 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
403 {
404         unsigned long flags;
405
406         if (!arch_clock || !arch_clock->clk_init_cpufreq_table)
407                 return;
408
409         spin_lock_irqsave(&clockfw_lock, flags);
410         arch_clock->clk_init_cpufreq_table(table);
411         spin_unlock_irqrestore(&clockfw_lock, flags);
412 }
413
414 void clk_exit_cpufreq_table(struct cpufreq_frequency_table **table)
415 {
416         unsigned long flags;
417
418         if (!arch_clock || !arch_clock->clk_exit_cpufreq_table)
419                 return;
420
421         spin_lock_irqsave(&clockfw_lock, flags);
422         arch_clock->clk_exit_cpufreq_table(table);
423         spin_unlock_irqrestore(&clockfw_lock, flags);
424 }
425 #endif
426
427 /*
428  *
429  */
430
431 #ifdef CONFIG_OMAP_RESET_CLOCKS
432 /*
433  * Disable any unused clocks left on by the bootloader
434  */
435 static int __init clk_disable_unused(void)
436 {
437         struct clk *ck;
438         unsigned long flags;
439
440         if (!arch_clock || !arch_clock->clk_disable_unused)
441                 return 0;
442
443         pr_info("clock: disabling unused clocks to save power\n");
444         list_for_each_entry(ck, &clocks, node) {
445                 if (ck->ops == &clkops_null)
446                         continue;
447
448                 if (ck->usecount > 0 || !ck->enable_reg)
449                         continue;
450
451                 spin_lock_irqsave(&clockfw_lock, flags);
452                 arch_clock->clk_disable_unused(ck);
453                 spin_unlock_irqrestore(&clockfw_lock, flags);
454         }
455
456         return 0;
457 }
458 late_initcall(clk_disable_unused);
459 late_initcall(omap_clk_enable_autoidle_all);
460 #endif
461
462 int __init clk_init(struct clk_functions * custom_clocks)
463 {
464         if (!custom_clocks) {
465                 pr_err("No custom clock functions registered\n");
466                 BUG();
467         }
468
469         arch_clock = custom_clocks;
470
471         return 0;
472 }
473
474 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
475 /*
476  *      debugfs support to trace clock tree hierarchy and attributes
477  */
478 static struct dentry *clk_debugfs_root;
479
480 static int clk_debugfs_register_one(struct clk *c)
481 {
482         int err;
483         struct dentry *d;
484         struct clk *pa = c->parent;
485         char s[255];
486         char *p = s;
487
488         p += sprintf(p, "%s", c->name);
489         d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
490         if (!d)
491                 return -ENOMEM;
492         c->dent = d;
493
494         d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
495         if (!d) {
496                 err = -ENOMEM;
497                 goto err_out;
498         }
499         d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
500         if (!d) {
501                 err = -ENOMEM;
502                 goto err_out;
503         }
504         d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
505         if (!d) {
506                 err = -ENOMEM;
507                 goto err_out;
508         }
509         return 0;
510
511 err_out:
512         d = c->dent;
513         debugfs_remove_recursive(c->dent);
514         return err;
515 }
516
517 static int clk_debugfs_register(struct clk *c)
518 {
519         int err;
520         struct clk *pa = c->parent;
521
522         if (pa && !pa->dent) {
523                 err = clk_debugfs_register(pa);
524                 if (err)
525                         return err;
526         }
527
528         if (!c->dent) {
529                 err = clk_debugfs_register_one(c);
530                 if (err)
531                         return err;
532         }
533         return 0;
534 }
535
536 static int __init clk_debugfs_init(void)
537 {
538         struct clk *c;
539         struct dentry *d;
540         int err;
541
542         d = debugfs_create_dir("clock", NULL);
543         if (!d)
544                 return -ENOMEM;
545         clk_debugfs_root = d;
546
547         list_for_each_entry(c, &clocks, node) {
548                 err = clk_debugfs_register(c);
549                 if (err)
550                         goto err_out;
551         }
552         return 0;
553 err_out:
554         debugfs_remove_recursive(clk_debugfs_root);
555         return err;
556 }
557 late_initcall(clk_debugfs_init);
558
559 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */