2 * drivers/sh/clk.c - SuperH clock framework
4 * Copyright (C) 2005 - 2009 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 #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>
32 static LIST_HEAD(clock_list);
33 static DEFINE_SPINLOCK(clock_lock);
34 static DEFINE_MUTEX(clock_list_sem);
36 void clk_rate_table_build(struct clk *clk,
37 struct cpufreq_frequency_table *freq_table,
39 struct clk_div_mult_table *src_table,
40 unsigned long *bitmap)
42 unsigned long mult, div;
46 for (i = 0; i < nr_freqs; i++) {
50 if (src_table->divisors && i < src_table->nr_divisors)
51 div = src_table->divisors[i];
53 if (src_table->multipliers && i < src_table->nr_multipliers)
54 mult = src_table->multipliers[i];
56 if (!div || !mult || (bitmap && !test_bit(i, bitmap)))
57 freq = CPUFREQ_ENTRY_INVALID;
59 freq = clk->parent->rate * mult / div;
61 freq_table[i].index = i;
62 freq_table[i].frequency = freq;
65 /* Termination entry */
66 freq_table[i].index = i;
67 freq_table[i].frequency = CPUFREQ_TABLE_END;
70 long clk_rate_table_round(struct clk *clk,
71 struct cpufreq_frequency_table *freq_table,
74 unsigned long rate_error, rate_error_prev = ~0UL;
75 unsigned long rate_best_fit = rate;
76 unsigned long highest, lowest;
81 for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
82 unsigned long freq = freq_table[i].frequency;
84 if (freq == CPUFREQ_ENTRY_INVALID)
92 rate_error = abs(freq - rate);
93 if (rate_error < rate_error_prev) {
95 rate_error_prev = rate_error;
103 rate_best_fit = highest;
105 rate_best_fit = lowest;
107 return rate_best_fit;
110 int clk_rate_table_find(struct clk *clk,
111 struct cpufreq_frequency_table *freq_table,
116 for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
117 unsigned long freq = freq_table[i].frequency;
119 if (freq == CPUFREQ_ENTRY_INVALID)
129 /* Used for clocks that always have same value as the parent clock */
130 unsigned long followparent_recalc(struct clk *clk)
132 return clk->parent ? clk->parent->rate : 0;
135 int clk_reparent(struct clk *child, struct clk *parent)
137 list_del_init(&child->sibling);
139 list_add(&child->sibling, &parent->children);
140 child->parent = parent;
142 /* now do the debugfs renaming to reattach the child
143 to the proper parent */
148 /* Propagate rate to children */
149 void propagate_rate(struct clk *tclk)
153 list_for_each_entry(clkp, &tclk->children, sibling) {
154 if (clkp->ops && clkp->ops->recalc)
155 clkp->rate = clkp->ops->recalc(clkp);
157 propagate_rate(clkp);
161 static void __clk_disable(struct clk *clk)
163 if (WARN(!clk->usecount, "Trying to disable clock %s with 0 usecount\n",
167 if (!(--clk->usecount)) {
168 if (likely(clk->ops && clk->ops->disable))
169 clk->ops->disable(clk);
170 if (likely(clk->parent))
171 __clk_disable(clk->parent);
175 void clk_disable(struct clk *clk)
182 spin_lock_irqsave(&clock_lock, flags);
184 spin_unlock_irqrestore(&clock_lock, flags);
186 EXPORT_SYMBOL_GPL(clk_disable);
188 static int __clk_enable(struct clk *clk)
192 if (clk->usecount++ == 0) {
194 ret = __clk_enable(clk->parent);
199 if (clk->ops && clk->ops->enable) {
200 ret = clk->ops->enable(clk);
203 __clk_disable(clk->parent);
215 int clk_enable(struct clk *clk)
223 spin_lock_irqsave(&clock_lock, flags);
224 ret = __clk_enable(clk);
225 spin_unlock_irqrestore(&clock_lock, flags);
229 EXPORT_SYMBOL_GPL(clk_enable);
231 static LIST_HEAD(root_clks);
234 * recalculate_root_clocks - recalculate and propagate all root clocks
236 * Recalculates all root clocks (clocks with no parent), which if the
237 * clock's .recalc is set correctly, should also propagate their rates.
240 void recalculate_root_clocks(void)
244 list_for_each_entry(clkp, &root_clks, sibling) {
245 if (clkp->ops && clkp->ops->recalc)
246 clkp->rate = clkp->ops->recalc(clkp);
247 propagate_rate(clkp);
251 int clk_register(struct clk *clk)
253 if (clk == NULL || IS_ERR(clk))
257 * trap out already registered clocks
259 if (clk->node.next || clk->node.prev)
262 mutex_lock(&clock_list_sem);
264 INIT_LIST_HEAD(&clk->children);
268 list_add(&clk->sibling, &clk->parent->children);
270 list_add(&clk->sibling, &root_clks);
272 list_add(&clk->node, &clock_list);
273 if (clk->ops && clk->ops->init)
275 mutex_unlock(&clock_list_sem);
279 EXPORT_SYMBOL_GPL(clk_register);
281 void clk_unregister(struct clk *clk)
283 mutex_lock(&clock_list_sem);
284 list_del(&clk->sibling);
285 list_del(&clk->node);
286 mutex_unlock(&clock_list_sem);
288 EXPORT_SYMBOL_GPL(clk_unregister);
290 void clk_enable_init_clocks(void)
294 list_for_each_entry(clkp, &clock_list, node)
295 if (clkp->flags & CLK_ENABLE_ON_INIT)
299 unsigned long clk_get_rate(struct clk *clk)
303 EXPORT_SYMBOL_GPL(clk_get_rate);
305 int clk_set_rate(struct clk *clk, unsigned long rate)
307 return clk_set_rate_ex(clk, rate, 0);
309 EXPORT_SYMBOL_GPL(clk_set_rate);
311 int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id)
313 int ret = -EOPNOTSUPP;
316 spin_lock_irqsave(&clock_lock, flags);
318 if (likely(clk->ops && clk->ops->set_rate)) {
319 ret = clk->ops->set_rate(clk, rate, algo_id);
327 if (clk->ops && clk->ops->recalc)
328 clk->rate = clk->ops->recalc(clk);
333 spin_unlock_irqrestore(&clock_lock, flags);
337 EXPORT_SYMBOL_GPL(clk_set_rate_ex);
339 int clk_set_parent(struct clk *clk, struct clk *parent)
346 if (clk->parent == parent)
349 spin_lock_irqsave(&clock_lock, flags);
350 if (clk->usecount == 0) {
351 if (clk->ops->set_parent)
352 ret = clk->ops->set_parent(clk, parent);
354 ret = clk_reparent(clk, parent);
357 pr_debug("clock: set parent of %s to %s (new rate %ld)\n",
358 clk->name, clk->parent->name, clk->rate);
359 if (clk->ops->recalc)
360 clk->rate = clk->ops->recalc(clk);
365 spin_unlock_irqrestore(&clock_lock, flags);
369 EXPORT_SYMBOL_GPL(clk_set_parent);
371 struct clk *clk_get_parent(struct clk *clk)
375 EXPORT_SYMBOL_GPL(clk_get_parent);
377 long clk_round_rate(struct clk *clk, unsigned long rate)
379 if (likely(clk->ops && clk->ops->round_rate)) {
380 unsigned long flags, rounded;
382 spin_lock_irqsave(&clock_lock, flags);
383 rounded = clk->ops->round_rate(clk, rate);
384 spin_unlock_irqrestore(&clock_lock, flags);
389 return clk_get_rate(clk);
391 EXPORT_SYMBOL_GPL(clk_round_rate);
394 static int clks_sysdev_suspend(struct sys_device *dev, pm_message_t state)
396 static pm_message_t prev_state;
399 switch (state.event) {
401 /* Resumeing from hibernation */
402 if (prev_state.event != PM_EVENT_FREEZE)
405 list_for_each_entry(clkp, &clock_list, node) {
406 if (likely(clkp->ops)) {
407 unsigned long rate = clkp->rate;
409 if (likely(clkp->ops->set_parent))
410 clkp->ops->set_parent(clkp,
412 if (likely(clkp->ops->set_rate))
413 clkp->ops->set_rate(clkp,
415 else if (likely(clkp->ops->recalc))
416 clkp->rate = clkp->ops->recalc(clkp);
420 case PM_EVENT_FREEZE:
422 case PM_EVENT_SUSPEND:
430 static int clks_sysdev_resume(struct sys_device *dev)
432 return clks_sysdev_suspend(dev, PMSG_ON);
435 static struct sysdev_class clks_sysdev_class = {
439 static struct sysdev_driver clks_sysdev_driver = {
440 .suspend = clks_sysdev_suspend,
441 .resume = clks_sysdev_resume,
444 static struct sys_device clks_sysdev_dev = {
445 .cls = &clks_sysdev_class,
448 static int __init clk_sysdev_init(void)
450 sysdev_class_register(&clks_sysdev_class);
451 sysdev_driver_register(&clks_sysdev_class, &clks_sysdev_driver);
452 sysdev_register(&clks_sysdev_dev);
456 subsys_initcall(clk_sysdev_init);
460 * debugfs support to trace clock tree hierarchy and attributes
462 static struct dentry *clk_debugfs_root;
464 static int clk_debugfs_register_one(struct clk *c)
467 struct dentry *d, *child, *child_tmp;
468 struct clk *pa = c->parent;
472 p += sprintf(p, "%s", c->name);
474 sprintf(p, ":%d", c->id);
475 d = debugfs_create_dir(s, pa ? pa->dentry : clk_debugfs_root);
480 d = debugfs_create_u8("usecount", S_IRUGO, c->dentry, (u8 *)&c->usecount);
485 d = debugfs_create_u32("rate", S_IRUGO, c->dentry, (u32 *)&c->rate);
490 d = debugfs_create_x32("flags", S_IRUGO, c->dentry, (u32 *)&c->flags);
499 list_for_each_entry_safe(child, child_tmp, &d->d_subdirs, d_u.d_child)
500 debugfs_remove(child);
501 debugfs_remove(c->dentry);
505 static int clk_debugfs_register(struct clk *c)
508 struct clk *pa = c->parent;
510 if (pa && !pa->dentry) {
511 err = clk_debugfs_register(pa);
516 if (!c->dentry && c->name) {
517 err = clk_debugfs_register_one(c);
524 static int __init clk_debugfs_init(void)
530 d = debugfs_create_dir("clock", NULL);
533 clk_debugfs_root = d;
535 list_for_each_entry(c, &clock_list, node) {
536 err = clk_debugfs_register(c);
542 debugfs_remove_recursive(clk_debugfs_root);
545 late_initcall(clk_debugfs_init);