2 * linux/arch/arm/plat-omap/clock.c
4 * Copyright (C) 2004 - 2008 Nokia corporation
5 * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
7 * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
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.
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>
25 #include <plat/clock.h>
27 static LIST_HEAD(clocks);
28 static DEFINE_MUTEX(clocks_mutex);
29 static DEFINE_SPINLOCK(clockfw_lock);
31 static struct clk_functions *arch_clock;
34 * Standard clock functions defined in include/linux/clk.h
37 int clk_enable(struct clk *clk)
42 if (clk == NULL || IS_ERR(clk))
45 if (!arch_clock || !arch_clock->clk_enable)
48 spin_lock_irqsave(&clockfw_lock, flags);
49 ret = arch_clock->clk_enable(clk);
50 spin_unlock_irqrestore(&clockfw_lock, flags);
54 EXPORT_SYMBOL(clk_enable);
56 void clk_disable(struct clk *clk)
60 if (clk == NULL || IS_ERR(clk))
63 if (!arch_clock || !arch_clock->clk_disable)
66 spin_lock_irqsave(&clockfw_lock, flags);
67 if (clk->usecount == 0) {
68 pr_err("Trying disable clock %s with 0 usecount\n",
74 arch_clock->clk_disable(clk);
77 spin_unlock_irqrestore(&clockfw_lock, flags);
79 EXPORT_SYMBOL(clk_disable);
81 unsigned long clk_get_rate(struct clk *clk)
86 if (clk == NULL || IS_ERR(clk))
89 spin_lock_irqsave(&clockfw_lock, flags);
91 spin_unlock_irqrestore(&clockfw_lock, flags);
95 EXPORT_SYMBOL(clk_get_rate);
98 * Optional clock functions defined in include/linux/clk.h
101 long clk_round_rate(struct clk *clk, unsigned long rate)
106 if (clk == NULL || IS_ERR(clk))
109 if (!arch_clock || !arch_clock->clk_round_rate)
112 spin_lock_irqsave(&clockfw_lock, flags);
113 ret = arch_clock->clk_round_rate(clk, rate);
114 spin_unlock_irqrestore(&clockfw_lock, flags);
118 EXPORT_SYMBOL(clk_round_rate);
120 int clk_set_rate(struct clk *clk, unsigned long rate)
125 if (clk == NULL || IS_ERR(clk))
128 if (!arch_clock || !arch_clock->clk_set_rate)
131 spin_lock_irqsave(&clockfw_lock, flags);
132 ret = arch_clock->clk_set_rate(clk, rate);
135 spin_unlock_irqrestore(&clockfw_lock, flags);
139 EXPORT_SYMBOL(clk_set_rate);
141 int clk_set_parent(struct clk *clk, struct clk *parent)
146 if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
149 if (!arch_clock || !arch_clock->clk_set_parent)
152 spin_lock_irqsave(&clockfw_lock, flags);
153 if (clk->usecount == 0) {
154 ret = arch_clock->clk_set_parent(clk, parent);
159 spin_unlock_irqrestore(&clockfw_lock, flags);
163 EXPORT_SYMBOL(clk_set_parent);
165 struct clk *clk_get_parent(struct clk *clk)
169 EXPORT_SYMBOL(clk_get_parent);
172 * OMAP specific clock functions shared between omap1 and omap2
175 int __initdata mpurate;
178 * By default we use the rate set by the bootloader.
179 * You can override this with mpurate= cmdline option.
181 static int __init omap_clk_setup(char *str)
183 get_option(&str, &mpurate);
193 __setup("mpurate=", omap_clk_setup);
195 /* Used for clocks that always have same value as the parent clock */
196 unsigned long followparent_recalc(struct clk *clk)
198 return clk->parent->rate;
202 * Used for clocks that have the same value as the parent clock,
203 * divided by some factor
205 unsigned long omap_fixed_divisor_recalc(struct clk *clk)
207 WARN_ON(!clk->fixed_div);
209 return clk->parent->rate / clk->fixed_div;
212 void clk_reparent(struct clk *child, struct clk *parent)
214 list_del_init(&child->sibling);
216 list_add(&child->sibling, &parent->children);
217 child->parent = parent;
219 /* now do the debugfs renaming to reattach the child
220 to the proper parent */
223 /* Propagate rate to children */
224 void propagate_rate(struct clk *tclk)
228 list_for_each_entry(clkp, &tclk->children, sibling) {
230 clkp->rate = clkp->recalc(clkp);
231 propagate_rate(clkp);
235 static LIST_HEAD(root_clks);
238 * recalculate_root_clocks - recalculate and propagate all root clocks
240 * Recalculates all root clocks (clocks with no parent), which if the
241 * clock's .recalc is set correctly, should also propagate their rates.
244 void recalculate_root_clocks(void)
248 list_for_each_entry(clkp, &root_clks, sibling) {
250 clkp->rate = clkp->recalc(clkp);
251 propagate_rate(clkp);
256 * clk_preinit - initialize any fields in the struct clk before clk init
257 * @clk: struct clk * to initialize
259 * Initialize any struct clk fields needed before normal clk initialization
260 * can run. No return value.
262 void clk_preinit(struct clk *clk)
264 INIT_LIST_HEAD(&clk->children);
267 int clk_register(struct clk *clk)
269 if (clk == NULL || IS_ERR(clk))
273 * trap out already registered clocks
275 if (clk->node.next || clk->node.prev)
278 mutex_lock(&clocks_mutex);
280 list_add(&clk->sibling, &clk->parent->children);
282 list_add(&clk->sibling, &root_clks);
284 list_add(&clk->node, &clocks);
287 mutex_unlock(&clocks_mutex);
291 EXPORT_SYMBOL(clk_register);
293 void clk_unregister(struct clk *clk)
295 if (clk == NULL || IS_ERR(clk))
298 mutex_lock(&clocks_mutex);
299 list_del(&clk->sibling);
300 list_del(&clk->node);
301 mutex_unlock(&clocks_mutex);
303 EXPORT_SYMBOL(clk_unregister);
305 void clk_enable_init_clocks(void)
309 list_for_each_entry(clkp, &clocks, node) {
310 if (clkp->flags & ENABLE_ON_INIT)
316 * omap_clk_get_by_name - locate OMAP struct clk by its name
317 * @name: name of the struct clk to locate
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.
323 struct clk *omap_clk_get_by_name(const char *name)
326 struct clk *ret = NULL;
328 mutex_lock(&clocks_mutex);
330 list_for_each_entry(c, &clocks, node) {
331 if (!strcmp(c->name, name)) {
337 mutex_unlock(&clocks_mutex);
342 int omap_clk_enable_autoidle_all(void)
347 spin_lock_irqsave(&clockfw_lock, flags);
349 list_for_each_entry(c, &clocks, node)
350 if (c->ops->allow_idle)
351 c->ops->allow_idle(c);
353 spin_unlock_irqrestore(&clockfw_lock, flags);
358 int omap_clk_disable_autoidle_all(void)
363 spin_lock_irqsave(&clockfw_lock, flags);
365 list_for_each_entry(c, &clocks, node)
366 if (c->ops->deny_idle)
367 c->ops->deny_idle(c);
369 spin_unlock_irqrestore(&clockfw_lock, flags);
377 static int clkll_enable_null(struct clk *clk)
382 static void clkll_disable_null(struct clk *clk)
386 const struct clkops clkops_null = {
387 .enable = clkll_enable_null,
388 .disable = clkll_disable_null,
394 * Used for clock aliases that are needed on some OMAPs, but not others
396 struct clk dummy_ck = {
401 #ifdef CONFIG_CPU_FREQ
402 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
406 if (!arch_clock || !arch_clock->clk_init_cpufreq_table)
409 spin_lock_irqsave(&clockfw_lock, flags);
410 arch_clock->clk_init_cpufreq_table(table);
411 spin_unlock_irqrestore(&clockfw_lock, flags);
414 void clk_exit_cpufreq_table(struct cpufreq_frequency_table **table)
418 if (!arch_clock || !arch_clock->clk_exit_cpufreq_table)
421 spin_lock_irqsave(&clockfw_lock, flags);
422 arch_clock->clk_exit_cpufreq_table(table);
423 spin_unlock_irqrestore(&clockfw_lock, flags);
431 #ifdef CONFIG_OMAP_RESET_CLOCKS
433 * Disable any unused clocks left on by the bootloader
435 static int __init clk_disable_unused(void)
440 if (!arch_clock || !arch_clock->clk_disable_unused)
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)
448 if (ck->usecount > 0 || !ck->enable_reg)
451 spin_lock_irqsave(&clockfw_lock, flags);
452 arch_clock->clk_disable_unused(ck);
453 spin_unlock_irqrestore(&clockfw_lock, flags);
458 late_initcall(clk_disable_unused);
459 late_initcall(omap_clk_enable_autoidle_all);
462 int __init clk_init(struct clk_functions * custom_clocks)
464 if (!custom_clocks) {
465 pr_err("No custom clock functions registered\n");
469 arch_clock = custom_clocks;
474 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
476 * debugfs support to trace clock tree hierarchy and attributes
479 #include <linux/debugfs.h>
480 #include <linux/seq_file.h>
482 static struct dentry *clk_debugfs_root;
484 static int clk_dbg_show_summary(struct seq_file *s, void *unused)
489 seq_printf(s, "%-30s %-30s %-10s %s\n",
490 "clock-name", "parent-name", "rate", "use-count");
492 list_for_each_entry(c, &clocks, node) {
494 seq_printf(s, "%-30s %-30s %-10lu %d\n",
495 c->name, pa ? pa->name : "none", c->rate, c->usecount);
501 static int clk_dbg_open(struct inode *inode, struct file *file)
503 return single_open(file, clk_dbg_show_summary, inode->i_private);
506 static const struct file_operations debug_clock_fops = {
507 .open = clk_dbg_open,
510 .release = single_release,
513 static int clk_debugfs_register_one(struct clk *c)
517 struct clk *pa = c->parent;
519 d = debugfs_create_dir(c->name, pa ? pa->dent : clk_debugfs_root);
524 d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
529 d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
534 d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
542 debugfs_remove_recursive(c->dent);
546 static int clk_debugfs_register(struct clk *c)
549 struct clk *pa = c->parent;
551 if (pa && !pa->dent) {
552 err = clk_debugfs_register(pa);
558 err = clk_debugfs_register_one(c);
565 static int __init clk_debugfs_init(void)
571 d = debugfs_create_dir("clock", NULL);
574 clk_debugfs_root = d;
576 list_for_each_entry(c, &clocks, node) {
577 err = clk_debugfs_register(c);
582 d = debugfs_create_file("summary", S_IRUGO,
583 d, NULL, &debug_clock_fops);
589 debugfs_remove_recursive(clk_debugfs_root);
592 late_initcall(clk_debugfs_init);
594 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */