2 * SuperH clock framework
4 * Copyright (C) 2005 - 2010 Paul Mundt
6 * This clock framework is derived from the OMAP version by:
8 * Copyright (C) 2004 - 2008 Nokia Corporation
9 * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
11 * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
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
17 #define pr_fmt(fmt) "clock: " fmt
19 #include <linux/kernel.h>
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/mutex.h>
23 #include <linux/list.h>
24 #include <linux/kobject.h>
25 #include <linux/sysdev.h>
26 #include <linux/seq_file.h>
27 #include <linux/err.h>
29 #include <linux/debugfs.h>
30 #include <linux/cpufreq.h>
31 #include <linux/clk.h>
32 #include <linux/sh_clk.h>
34 static LIST_HEAD(clock_list);
35 static DEFINE_SPINLOCK(clock_lock);
36 static DEFINE_MUTEX(clock_list_sem);
38 void clk_rate_table_build(struct clk *clk,
39 struct cpufreq_frequency_table *freq_table,
41 struct clk_div_mult_table *src_table,
42 unsigned long *bitmap)
44 unsigned long mult, div;
48 clk->nr_freqs = nr_freqs;
50 for (i = 0; i < nr_freqs; i++) {
54 if (src_table->divisors && i < src_table->nr_divisors)
55 div = src_table->divisors[i];
57 if (src_table->multipliers && i < src_table->nr_multipliers)
58 mult = src_table->multipliers[i];
60 if (!div || !mult || (bitmap && !test_bit(i, bitmap)))
61 freq = CPUFREQ_ENTRY_INVALID;
63 freq = clk->parent->rate * mult / div;
65 freq_table[i].index = i;
66 freq_table[i].frequency = freq;
69 /* Termination entry */
70 freq_table[i].index = i;
71 freq_table[i].frequency = CPUFREQ_TABLE_END;
74 struct clk_rate_round_data;
76 struct clk_rate_round_data {
78 unsigned int min, max;
79 long (*func)(unsigned int, struct clk_rate_round_data *);
83 #define for_each_frequency(pos, r, freq) \
84 for (pos = r->min, freq = r->func(pos, r); \
85 pos <= r->max; pos++, freq = r->func(pos, r)) \
86 if (unlikely(freq == 0)) \
90 static long clk_rate_round_helper(struct clk_rate_round_data *rounder)
92 unsigned long rate_error, rate_error_prev = ~0UL;
93 unsigned long highest, lowest, freq;
94 long rate_best_fit = -ENOENT;
100 for_each_frequency(i, rounder, freq) {
106 rate_error = abs(freq - rounder->rate);
107 if (rate_error < rate_error_prev) {
108 rate_best_fit = freq;
109 rate_error_prev = rate_error;
116 if (rounder->rate >= highest)
117 rate_best_fit = highest;
118 if (rounder->rate <= lowest)
119 rate_best_fit = lowest;
121 return rate_best_fit;
124 static long clk_rate_table_iter(unsigned int pos,
125 struct clk_rate_round_data *rounder)
127 struct cpufreq_frequency_table *freq_table = rounder->arg;
128 unsigned long freq = freq_table[pos].frequency;
130 if (freq == CPUFREQ_ENTRY_INVALID)
136 long clk_rate_table_round(struct clk *clk,
137 struct cpufreq_frequency_table *freq_table,
140 struct clk_rate_round_data table_round = {
142 .max = clk->nr_freqs - 1,
143 .func = clk_rate_table_iter,
148 if (clk->nr_freqs < 1)
151 return clk_rate_round_helper(&table_round);
154 static long clk_rate_div_range_iter(unsigned int pos,
155 struct clk_rate_round_data *rounder)
157 return clk_get_rate(rounder->arg) / pos;
160 long clk_rate_div_range_round(struct clk *clk, unsigned int div_min,
161 unsigned int div_max, unsigned long rate)
163 struct clk_rate_round_data div_range_round = {
166 .func = clk_rate_div_range_iter,
167 .arg = clk_get_parent(clk),
171 return clk_rate_round_helper(&div_range_round);
174 int clk_rate_table_find(struct clk *clk,
175 struct cpufreq_frequency_table *freq_table,
180 for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
181 unsigned long freq = freq_table[i].frequency;
183 if (freq == CPUFREQ_ENTRY_INVALID)
193 /* Used for clocks that always have same value as the parent clock */
194 unsigned long followparent_recalc(struct clk *clk)
196 return clk->parent ? clk->parent->rate : 0;
199 int clk_reparent(struct clk *child, struct clk *parent)
201 list_del_init(&child->sibling);
203 list_add(&child->sibling, &parent->children);
204 child->parent = parent;
206 /* now do the debugfs renaming to reattach the child
207 to the proper parent */
212 /* Propagate rate to children */
213 void propagate_rate(struct clk *tclk)
217 list_for_each_entry(clkp, &tclk->children, sibling) {
218 if (clkp->ops && clkp->ops->recalc)
219 clkp->rate = clkp->ops->recalc(clkp);
221 propagate_rate(clkp);
225 static void __clk_disable(struct clk *clk)
227 if (WARN(!clk->usecount, "Trying to disable clock %p with 0 usecount\n",
231 if (!(--clk->usecount)) {
232 if (likely(clk->ops && clk->ops->disable))
233 clk->ops->disable(clk);
234 if (likely(clk->parent))
235 __clk_disable(clk->parent);
239 void clk_disable(struct clk *clk)
246 spin_lock_irqsave(&clock_lock, flags);
248 spin_unlock_irqrestore(&clock_lock, flags);
250 EXPORT_SYMBOL_GPL(clk_disable);
252 static int __clk_enable(struct clk *clk)
256 if (clk->usecount++ == 0) {
258 ret = __clk_enable(clk->parent);
263 if (clk->ops && clk->ops->enable) {
264 ret = clk->ops->enable(clk);
267 __clk_disable(clk->parent);
279 int clk_enable(struct clk *clk)
287 spin_lock_irqsave(&clock_lock, flags);
288 ret = __clk_enable(clk);
289 spin_unlock_irqrestore(&clock_lock, flags);
293 EXPORT_SYMBOL_GPL(clk_enable);
295 static LIST_HEAD(root_clks);
298 * recalculate_root_clocks - recalculate and propagate all root clocks
300 * Recalculates all root clocks (clocks with no parent), which if the
301 * clock's .recalc is set correctly, should also propagate their rates.
304 void recalculate_root_clocks(void)
308 list_for_each_entry(clkp, &root_clks, sibling) {
309 if (clkp->ops && clkp->ops->recalc)
310 clkp->rate = clkp->ops->recalc(clkp);
311 propagate_rate(clkp);
315 static struct clk_mapping dummy_mapping;
317 static struct clk *lookup_root_clock(struct clk *clk)
325 static int clk_establish_mapping(struct clk *clk)
327 struct clk_mapping *mapping = clk->mapping;
330 * Propagate mappings.
336 * dummy mapping for root clocks with no specified ranges
339 clk->mapping = &dummy_mapping;
344 * If we're on a child clock and it provides no mapping of its
345 * own, inherit the mapping from its root clock.
347 clkp = lookup_root_clock(clk);
348 mapping = clkp->mapping;
353 * Establish initial mapping.
355 if (!mapping->base && mapping->phys) {
356 kref_init(&mapping->ref);
358 mapping->base = ioremap_nocache(mapping->phys, mapping->len);
359 if (unlikely(!mapping->base))
361 } else if (mapping->base) {
363 * Bump the refcount for an existing mapping
365 kref_get(&mapping->ref);
368 clk->mapping = mapping;
372 static void clk_destroy_mapping(struct kref *kref)
374 struct clk_mapping *mapping;
376 mapping = container_of(kref, struct clk_mapping, ref);
378 iounmap(mapping->base);
381 static void clk_teardown_mapping(struct clk *clk)
383 struct clk_mapping *mapping = clk->mapping;
386 if (mapping == &dummy_mapping)
389 kref_put(&mapping->ref, clk_destroy_mapping);
393 int clk_register(struct clk *clk)
397 if (clk == NULL || IS_ERR(clk))
401 * trap out already registered clocks
403 if (clk->node.next || clk->node.prev)
406 mutex_lock(&clock_list_sem);
408 INIT_LIST_HEAD(&clk->children);
411 ret = clk_establish_mapping(clk);
416 list_add(&clk->sibling, &clk->parent->children);
418 list_add(&clk->sibling, &root_clks);
420 list_add(&clk->node, &clock_list);
421 if (clk->ops && clk->ops->init)
425 mutex_unlock(&clock_list_sem);
429 EXPORT_SYMBOL_GPL(clk_register);
431 void clk_unregister(struct clk *clk)
433 mutex_lock(&clock_list_sem);
434 list_del(&clk->sibling);
435 list_del(&clk->node);
436 clk_teardown_mapping(clk);
437 mutex_unlock(&clock_list_sem);
439 EXPORT_SYMBOL_GPL(clk_unregister);
441 void clk_enable_init_clocks(void)
445 list_for_each_entry(clkp, &clock_list, node)
446 if (clkp->flags & CLK_ENABLE_ON_INIT)
450 unsigned long clk_get_rate(struct clk *clk)
454 EXPORT_SYMBOL_GPL(clk_get_rate);
456 int clk_set_rate(struct clk *clk, unsigned long rate)
458 return clk_set_rate_ex(clk, rate, 0);
460 EXPORT_SYMBOL_GPL(clk_set_rate);
462 int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id)
464 int ret = -EOPNOTSUPP;
467 spin_lock_irqsave(&clock_lock, flags);
469 if (likely(clk->ops && clk->ops->set_rate)) {
470 ret = clk->ops->set_rate(clk, rate, algo_id);
478 if (clk->ops && clk->ops->recalc)
479 clk->rate = clk->ops->recalc(clk);
484 spin_unlock_irqrestore(&clock_lock, flags);
488 EXPORT_SYMBOL_GPL(clk_set_rate_ex);
490 int clk_set_parent(struct clk *clk, struct clk *parent)
497 if (clk->parent == parent)
500 spin_lock_irqsave(&clock_lock, flags);
501 if (clk->usecount == 0) {
502 if (clk->ops->set_parent)
503 ret = clk->ops->set_parent(clk, parent);
505 ret = clk_reparent(clk, parent);
508 if (clk->ops->recalc)
509 clk->rate = clk->ops->recalc(clk);
510 pr_debug("set parent of %p to %p (new rate %ld)\n",
511 clk, clk->parent, clk->rate);
516 spin_unlock_irqrestore(&clock_lock, flags);
520 EXPORT_SYMBOL_GPL(clk_set_parent);
522 struct clk *clk_get_parent(struct clk *clk)
526 EXPORT_SYMBOL_GPL(clk_get_parent);
528 long clk_round_rate(struct clk *clk, unsigned long rate)
530 if (likely(clk->ops && clk->ops->round_rate)) {
531 unsigned long flags, rounded;
533 spin_lock_irqsave(&clock_lock, flags);
534 rounded = clk->ops->round_rate(clk, rate);
535 spin_unlock_irqrestore(&clock_lock, flags);
540 return clk_get_rate(clk);
542 EXPORT_SYMBOL_GPL(clk_round_rate);
544 long clk_round_parent(struct clk *clk, unsigned long target,
545 unsigned long *best_freq, unsigned long *parent_freq,
546 unsigned int div_min, unsigned int div_max)
548 struct cpufreq_frequency_table *freq, *best = NULL;
549 unsigned long error = ULONG_MAX, freq_high, freq_low, div;
550 struct clk *parent = clk_get_parent(clk);
554 *best_freq = clk_round_rate(clk, target);
555 return abs(target - *best_freq);
558 for (freq = parent->freq_table; freq->frequency != CPUFREQ_TABLE_END;
560 if (freq->frequency == CPUFREQ_ENTRY_INVALID)
563 if (unlikely(freq->frequency / target <= div_min - 1)) {
564 unsigned long freq_max;
566 freq_max = (freq->frequency + div_min / 2) / div_min;
567 if (error > target - freq_max) {
568 error = target - freq_max;
571 *best_freq = freq_max;
574 pr_debug("too low freq %lu, error %lu\n", freq->frequency,
583 if (unlikely(freq->frequency / target >= div_max)) {
584 unsigned long freq_min;
586 freq_min = (freq->frequency + div_max / 2) / div_max;
587 if (error > freq_min - target) {
588 error = freq_min - target;
591 *best_freq = freq_min;
594 pr_debug("too high freq %lu, error %lu\n", freq->frequency,
603 div = freq->frequency / target;
604 freq_high = freq->frequency / div;
605 freq_low = freq->frequency / (div + 1);
607 if (freq_high - target < error) {
608 error = freq_high - target;
611 *best_freq = freq_high;
614 if (target - freq_low < error) {
615 error = target - freq_low;
618 *best_freq = freq_low;
621 pr_debug("%u / %lu = %lu, / %lu = %lu, best %lu, parent %u\n",
622 freq->frequency, div, freq_high, div + 1, freq_low,
623 *best_freq, best->frequency);
630 *parent_freq = best->frequency;
634 EXPORT_SYMBOL_GPL(clk_round_parent);
637 static int clks_sysdev_suspend(struct sys_device *dev, pm_message_t state)
639 static pm_message_t prev_state;
642 switch (state.event) {
644 /* Resumeing from hibernation */
645 if (prev_state.event != PM_EVENT_FREEZE)
648 list_for_each_entry(clkp, &clock_list, node) {
649 if (likely(clkp->ops)) {
650 unsigned long rate = clkp->rate;
652 if (likely(clkp->ops->set_parent))
653 clkp->ops->set_parent(clkp,
655 if (likely(clkp->ops->set_rate))
656 clkp->ops->set_rate(clkp,
658 else if (likely(clkp->ops->recalc))
659 clkp->rate = clkp->ops->recalc(clkp);
663 case PM_EVENT_FREEZE:
665 case PM_EVENT_SUSPEND:
673 static int clks_sysdev_resume(struct sys_device *dev)
675 return clks_sysdev_suspend(dev, PMSG_ON);
678 static struct sysdev_class clks_sysdev_class = {
682 static struct sysdev_driver clks_sysdev_driver = {
683 .suspend = clks_sysdev_suspend,
684 .resume = clks_sysdev_resume,
687 static struct sys_device clks_sysdev_dev = {
688 .cls = &clks_sysdev_class,
691 static int __init clk_sysdev_init(void)
693 sysdev_class_register(&clks_sysdev_class);
694 sysdev_driver_register(&clks_sysdev_class, &clks_sysdev_driver);
695 sysdev_register(&clks_sysdev_dev);
699 subsys_initcall(clk_sysdev_init);
703 * debugfs support to trace clock tree hierarchy and attributes
705 static struct dentry *clk_debugfs_root;
707 static int clk_debugfs_register_one(struct clk *c)
710 struct dentry *d, *child, *child_tmp;
711 struct clk *pa = c->parent;
715 p += sprintf(p, "%p", c);
716 d = debugfs_create_dir(s, pa ? pa->dentry : clk_debugfs_root);
721 d = debugfs_create_u8("usecount", S_IRUGO, c->dentry, (u8 *)&c->usecount);
726 d = debugfs_create_u32("rate", S_IRUGO, c->dentry, (u32 *)&c->rate);
731 d = debugfs_create_x32("flags", S_IRUGO, c->dentry, (u32 *)&c->flags);
740 list_for_each_entry_safe(child, child_tmp, &d->d_subdirs, d_u.d_child)
741 debugfs_remove(child);
742 debugfs_remove(c->dentry);
746 static int clk_debugfs_register(struct clk *c)
749 struct clk *pa = c->parent;
751 if (pa && !pa->dentry) {
752 err = clk_debugfs_register(pa);
758 err = clk_debugfs_register_one(c);
765 static int __init clk_debugfs_init(void)
771 d = debugfs_create_dir("clock", NULL);
774 clk_debugfs_root = d;
776 list_for_each_entry(c, &clock_list, node) {
777 err = clk_debugfs_register(c);
783 debugfs_remove_recursive(clk_debugfs_root);
786 late_initcall(clk_debugfs_init);