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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/export.h>
18#include <linux/err.h>
19#include <linux/string.h>
20#include <linux/clk.h>
21#include <linux/mutex.h>
22#include <linux/cpufreq.h>
23#include <linux/io.h>
24
25#include <plat/clock.h>
26
27static LIST_HEAD(clocks);
28static DEFINE_MUTEX(clocks_mutex);
29static DEFINE_SPINLOCK(clockfw_lock);
30
31static struct clk_functions *arch_clock;
32
33/*
34 * Standard clock functions defined in include/linux/clk.h
35 */
36
37int 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}
54EXPORT_SYMBOL(clk_enable);
55
56void 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
76out:
77 spin_unlock_irqrestore(&clockfw_lock, flags);
78}
79EXPORT_SYMBOL(clk_disable);
80
81unsigned 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}
95EXPORT_SYMBOL(clk_get_rate);
96
97/*
98 * Optional clock functions defined in include/linux/clk.h
99 */
100
101long 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}
118EXPORT_SYMBOL(clk_round_rate);
119
120int 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}
139EXPORT_SYMBOL(clk_set_rate);
140
141int 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}
163EXPORT_SYMBOL(clk_set_parent);
164
165struct clk *clk_get_parent(struct clk *clk)
166{
167 return clk->parent;
168}
169EXPORT_SYMBOL(clk_get_parent);
170
171/*
172 * OMAP specific clock functions shared between omap1 and omap2
173 */
174
175int __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 */
181static 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 */
196unsigned 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 */
205unsigned 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
212void 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 */
224void 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
235static 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 */
244void 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 */
262void clk_preinit(struct clk *clk)
263{
264 INIT_LIST_HEAD(&clk->children);
265}
266
267int 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}
291EXPORT_SYMBOL(clk_register);
292
293void 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}
303EXPORT_SYMBOL(clk_unregister);
304
305void 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 */
323struct 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
342int 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
358int 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 */
377static int clkll_enable_null(struct clk *clk)
378{
379 return 0;
380}
381
382static void clkll_disable_null(struct clk *clk)
383{
384}
385
386const 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 */
396struct clk dummy_ck = {
397 .name = "dummy",
398 .ops = &clkops_null,
399};
400
401/*
402 *
403 */
404
405#ifdef CONFIG_OMAP_RESET_CLOCKS
406/*
407 * Disable any unused clocks left on by the bootloader
408 */
409static int __init clk_disable_unused(void)
410{
411 struct clk *ck;
412 unsigned long flags;
413
414 if (!arch_clock || !arch_clock->clk_disable_unused)
415 return 0;
416
417 pr_info("clock: disabling unused clocks to save power\n");
418
419 spin_lock_irqsave(&clockfw_lock, flags);
420 list_for_each_entry(ck, &clocks, node) {
421 if (ck->ops == &clkops_null)
422 continue;
423
424 if (ck->usecount > 0 || !ck->enable_reg)
425 continue;
426
427 arch_clock->clk_disable_unused(ck);
428 }
429 spin_unlock_irqrestore(&clockfw_lock, flags);
430
431 return 0;
432}
433late_initcall(clk_disable_unused);
434late_initcall(omap_clk_enable_autoidle_all);
435#endif
436
437int __init clk_init(struct clk_functions * custom_clocks)
438{
439 if (!custom_clocks) {
440 pr_err("No custom clock functions registered\n");
441 BUG();
442 }
443
444 arch_clock = custom_clocks;
445
446 return 0;
447}
448
449#if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
450/*
451 * debugfs support to trace clock tree hierarchy and attributes
452 */
453
454#include <linux/debugfs.h>
455#include <linux/seq_file.h>
456
457static struct dentry *clk_debugfs_root;
458
459static int clk_dbg_show_summary(struct seq_file *s, void *unused)
460{
461 struct clk *c;
462 struct clk *pa;
463
464 mutex_lock(&clocks_mutex);
465 seq_printf(s, "%-30s %-30s %-10s %s\n",
466 "clock-name", "parent-name", "rate", "use-count");
467
468 list_for_each_entry(c, &clocks, node) {
469 pa = c->parent;
470 seq_printf(s, "%-30s %-30s %-10lu %d\n",
471 c->name, pa ? pa->name : "none", c->rate, c->usecount);
472 }
473 mutex_unlock(&clocks_mutex);
474
475 return 0;
476}
477
478static int clk_dbg_open(struct inode *inode, struct file *file)
479{
480 return single_open(file, clk_dbg_show_summary, inode->i_private);
481}
482
483static const struct file_operations debug_clock_fops = {
484 .open = clk_dbg_open,
485 .read = seq_read,
486 .llseek = seq_lseek,
487 .release = single_release,
488};
489
490static int clk_debugfs_register_one(struct clk *c)
491{
492 int err;
493 struct dentry *d;
494 struct clk *pa = c->parent;
495
496 d = debugfs_create_dir(c->name, pa ? pa->dent : clk_debugfs_root);
497 if (!d)
498 return -ENOMEM;
499 c->dent = d;
500
501 d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
502 if (!d) {
503 err = -ENOMEM;
504 goto err_out;
505 }
506 d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
507 if (!d) {
508 err = -ENOMEM;
509 goto err_out;
510 }
511 d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
512 if (!d) {
513 err = -ENOMEM;
514 goto err_out;
515 }
516 return 0;
517
518err_out:
519 debugfs_remove_recursive(c->dent);
520 return err;
521}
522
523static int clk_debugfs_register(struct clk *c)
524{
525 int err;
526 struct clk *pa = c->parent;
527
528 if (pa && !pa->dent) {
529 err = clk_debugfs_register(pa);
530 if (err)
531 return err;
532 }
533
534 if (!c->dent) {
535 err = clk_debugfs_register_one(c);
536 if (err)
537 return err;
538 }
539 return 0;
540}
541
542static int __init clk_debugfs_init(void)
543{
544 struct clk *c;
545 struct dentry *d;
546 int err;
547
548 d = debugfs_create_dir("clock", NULL);
549 if (!d)
550 return -ENOMEM;
551 clk_debugfs_root = d;
552
553 list_for_each_entry(c, &clocks, node) {
554 err = clk_debugfs_register(c);
555 if (err)
556 goto err_out;
557 }
558
559 d = debugfs_create_file("summary", S_IRUGO,
560 d, NULL, &debug_clock_fops);
561 if (!d)
562 return -ENOMEM;
563
564 return 0;
565err_out:
566 debugfs_remove_recursive(clk_debugfs_root);
567 return err;
568}
569late_initcall(clk_debugfs_init);
570
571#endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */