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/module.h>
16 #include <linux/list.h>
17 #include <linux/errno.h>
18 #include <linux/err.h>
19 #include <linux/string.h>
20 #include <linux/clk.h>
21 #include <linux/mutex.h>
22 #include <linux/platform_device.h>
23 #include <linux/cpufreq.h>
24 #include <linux/debugfs.h>
26 #include <linux/bootmem.h>
27 #include <linux/slab.h>
29 #include <mach/clock.h>
31 static LIST_HEAD(clocks);
32 static DEFINE_MUTEX(clocks_mutex);
33 static DEFINE_SPINLOCK(clockfw_lock);
35 static struct clk_functions *arch_clock;
38 * omap_clk_for_each_child - call callback on each child clock of clk
39 * @clk: struct clk * to use as the "parent"
40 * @parent_rate: rate of the parent of @clk to pass along
41 * @rate_storage: flag indicating whether current or temporary rates are used
42 * @cb: pointer to a callback function
44 * For each child clock of @clk, call the callback function @cb, passing
45 * along the contents of @parent_rate and @rate_storage. If the callback
46 * function returns non-zero, terminate the function and pass along the
49 static int omap_clk_for_each_child(struct clk *clk, unsigned long parent_rate,
51 int (*cb)(struct clk *clk,
52 unsigned long parent_rate,
55 struct clk_child *child;
58 list_for_each_entry(child, &clk->children, node) {
59 ret = (*cb)(child->clk, parent_rate, rate_storage);
68 * omap_clk_has_children - does clk @clk have any child clocks?
69 * @clk: struct clk * to test for child clocks
71 * If clock @clk has any child clocks, return 1; otherwise, return 0.
73 static int omap_clk_has_children(struct clk *clk)
75 return (list_empty(&clk->children)) ? 0 : 1;
79 * _do_propagate_rate - callback function for rate propagation
80 * @clk: struct clk * to recalc and propagate from
81 * @parent_rate: rate of the parent of @clk, to use in recalculation
82 * @rate_storage: flag indicating whether current or temporary rates are used
84 * If @clk has a recalc function, call it. If @clk has any children,
85 * propagate @clk's rate. Returns 0.
87 static int _do_propagate_rate(struct clk *clk, unsigned long parent_rate,
91 clk->recalc(clk, parent_rate, rate_storage);
92 if (omap_clk_has_children(clk))
93 propagate_rate(clk, rate_storage);
98 * omap_clk_add_child - add a child clock @clk2 to @clk
99 * @clk: parent struct clk *
100 * @clk2: new child struct clk *
102 * Add a child clock @clk2 to the list of children of parent clock
103 * @clk. Will potentially allocate memory from bootmem or, if
104 * available, from slab. Must only be called with the clock framework
105 * spinlock held. No return value.
107 void omap_clk_add_child(struct clk *clk, struct clk *clk2)
109 struct clk_child *child;
112 if (!clk->children.next)
113 INIT_LIST_HEAD(&clk->children);
115 list_for_each_entry(child, &clk->children, node) {
116 if (child->flags & CLK_CHILD_DELETED) {
118 child->flags &= ~CLK_CHILD_DELETED;
124 if (slab_is_available())
125 child = kmalloc(sizeof(struct clk_child), GFP_ATOMIC);
127 child = alloc_bootmem(sizeof(struct clk_child));
134 memset(child, 0, sizeof(struct clk_child));
136 if (slab_is_available())
137 child->flags |= CLK_CHILD_SLAB_ALLOC;
142 list_add_tail(&child->node, &clk->children);
146 * omap_clk_del_child - add a child clock @clk2 to @clk
147 * @clk: parent struct clk *
148 * @clk2: former child struct clk *
150 * Remove a child clock @clk2 from the list of children of parent
151 * clock @clk. Must only be called with the clock framework spinlock
152 * held. No return value.
154 void omap_clk_del_child(struct clk *clk, struct clk *clk2)
156 struct clk_child *child, *tmp;
158 /* Loop over all existing clk_childs, when found, deallocate */
159 list_for_each_entry_safe(child, tmp, &clk->children, node) {
160 if (child->clk == clk2) {
161 list_del(&child->node);
162 if (child->flags & CLK_CHILD_SLAB_ALLOC) {
166 child->flags |= CLK_CHILD_DELETED;
173 /*-------------------------------------------------------------------------
174 * Standard clock functions defined in include/linux/clk.h
175 *-------------------------------------------------------------------------*/
178 * Returns a clock. Note that we first try to use device id on the bus
179 * and clock name. If this fails, we try to use clock name only.
181 struct clk * clk_get(struct device *dev, const char *id)
183 struct clk *p, *clk = ERR_PTR(-ENOENT);
186 if (dev == NULL || dev->bus != &platform_bus_type)
189 idno = to_platform_device(dev)->id;
191 mutex_lock(&clocks_mutex);
193 list_for_each_entry(p, &clocks, node) {
194 if (p->id == idno && strcmp(id, p->name) == 0) {
200 list_for_each_entry(p, &clocks, node) {
201 if (strcmp(id, p->name) == 0) {
208 mutex_unlock(&clocks_mutex);
212 EXPORT_SYMBOL(clk_get);
214 int clk_enable(struct clk *clk)
219 if (clk == NULL || IS_ERR(clk))
222 spin_lock_irqsave(&clockfw_lock, flags);
223 if (arch_clock->clk_enable) {
224 ret = arch_clock->clk_enable(clk);
225 if (ret == 0 && clk->flags & RECALC_ON_ENABLE)
226 _do_propagate_rate(clk, clk->parent->rate,
230 spin_unlock_irqrestore(&clockfw_lock, flags);
234 EXPORT_SYMBOL(clk_enable);
236 void clk_disable(struct clk *clk)
240 if (clk == NULL || IS_ERR(clk))
243 spin_lock_irqsave(&clockfw_lock, flags);
244 if (clk->usecount == 0) {
245 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
251 if (arch_clock->clk_disable) {
252 arch_clock->clk_disable(clk);
253 if (clk->flags & RECALC_ON_ENABLE)
254 _do_propagate_rate(clk, clk->parent->rate,
259 spin_unlock_irqrestore(&clockfw_lock, flags);
261 EXPORT_SYMBOL(clk_disable);
263 int clk_get_usecount(struct clk *clk)
268 if (clk == NULL || IS_ERR(clk))
271 spin_lock_irqsave(&clockfw_lock, flags);
273 spin_unlock_irqrestore(&clockfw_lock, flags);
277 EXPORT_SYMBOL(clk_get_usecount);
279 unsigned long clk_get_rate(struct clk *clk)
282 unsigned long ret = 0;
284 if (clk == NULL || IS_ERR(clk))
287 spin_lock_irqsave(&clockfw_lock, flags);
289 spin_unlock_irqrestore(&clockfw_lock, flags);
293 EXPORT_SYMBOL(clk_get_rate);
295 void clk_put(struct clk *clk)
298 EXPORT_SYMBOL(clk_put);
300 /*-------------------------------------------------------------------------
301 * Optional clock functions defined in include/linux/clk.h
302 *-------------------------------------------------------------------------*/
304 long clk_round_rate(struct clk *clk, unsigned long rate)
309 if (clk == NULL || IS_ERR(clk))
312 spin_lock_irqsave(&clockfw_lock, flags);
313 if (arch_clock->clk_round_rate)
314 ret = arch_clock->clk_round_rate(clk, rate);
315 spin_unlock_irqrestore(&clockfw_lock, flags);
319 EXPORT_SYMBOL(clk_round_rate);
321 int clk_set_rate(struct clk *clk, unsigned long rate)
326 if (clk == NULL || IS_ERR(clk))
329 spin_lock_irqsave(&clockfw_lock, flags);
331 if (arch_clock->clk_set_rate) {
332 ret = arch_clock->clk_set_rate(clk, rate);
334 _do_propagate_rate(clk, clk->parent->rate,
338 spin_unlock_irqrestore(&clockfw_lock, flags);
342 EXPORT_SYMBOL(clk_set_rate);
344 int clk_set_parent(struct clk *clk, struct clk *parent)
347 struct clk *prev_parent;
350 if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
353 spin_lock_irqsave(&clockfw_lock, flags);
355 if (arch_clock->clk_set_parent) {
356 prev_parent = clk->parent;
357 ret = arch_clock->clk_set_parent(clk, parent);
359 omap_clk_del_child(prev_parent, clk);
360 omap_clk_add_child(parent, clk);
361 _do_propagate_rate(clk, clk->parent->rate,
366 spin_unlock_irqrestore(&clockfw_lock, flags);
370 EXPORT_SYMBOL(clk_set_parent);
372 struct clk *clk_get_parent(struct clk *clk)
375 struct clk * ret = NULL;
377 if (clk == NULL || IS_ERR(clk))
380 spin_lock_irqsave(&clockfw_lock, flags);
381 if (arch_clock->clk_get_parent)
382 ret = arch_clock->clk_get_parent(clk);
383 spin_unlock_irqrestore(&clockfw_lock, flags);
387 EXPORT_SYMBOL(clk_get_parent);
389 /*-------------------------------------------------------------------------
390 * OMAP specific clock functions shared between omap1 and omap2
391 *-------------------------------------------------------------------------*/
393 unsigned int __initdata mpurate;
396 * By default we use the rate set by the bootloader.
397 * You can override this with mpurate= cmdline option.
399 static int __init omap_clk_setup(char *str)
401 get_option(&str, &mpurate);
411 __setup("mpurate=", omap_clk_setup);
413 /* Used for clocks that always have same value as the parent clock */
414 void followparent_recalc(struct clk *clk, unsigned long new_parent_rate,
417 if (rate_storage == CURRENT_RATE)
418 clk->rate = new_parent_rate;
419 else if (rate_storage == TEMP_RATE)
420 clk->temp_rate = new_parent_rate;
423 /* Propagate rate to children */
424 void propagate_rate(struct clk *tclk, u8 rate_storage)
426 unsigned long parent_rate = 0;
428 if (tclk == NULL || IS_ERR(tclk))
431 if (rate_storage == CURRENT_RATE)
432 parent_rate = tclk->rate;
433 else if (rate_storage == TEMP_RATE)
434 parent_rate = tclk->temp_rate;
436 omap_clk_for_each_child(tclk, parent_rate, rate_storage,
441 * recalculate_root_clocks - recalculate and propagate all root clocks
443 * Recalculates all root clocks (clocks with no parent), which if the
444 * clock's .recalc is set correctly, should also propagate their rates.
447 void recalculate_root_clocks(void)
451 list_for_each_entry(clkp, &clocks, node)
452 if (unlikely(!clkp->parent))
453 _do_propagate_rate(clkp, 0, CURRENT_RATE);
456 int clk_register(struct clk *clk)
458 if (clk == NULL || IS_ERR(clk))
461 mutex_lock(&clocks_mutex);
462 list_add(&clk->node, &clocks);
463 if (!clk->children.next)
464 INIT_LIST_HEAD(&clk->children);
466 omap_clk_add_child(clk->parent, clk);
469 mutex_unlock(&clocks_mutex);
473 EXPORT_SYMBOL(clk_register);
475 void clk_unregister(struct clk *clk)
477 struct clk_child *child, *tmp;
479 if (clk == NULL || IS_ERR(clk))
482 mutex_lock(&clocks_mutex);
483 list_del(&clk->node);
485 omap_clk_del_child(clk->parent, clk);
486 list_for_each_entry_safe(child, tmp, &clk->children, node)
487 if (child->flags & CLK_CHILD_SLAB_ALLOC)
489 mutex_unlock(&clocks_mutex);
491 EXPORT_SYMBOL(clk_unregister);
493 void clk_deny_idle(struct clk *clk)
497 if (clk == NULL || IS_ERR(clk))
500 spin_lock_irqsave(&clockfw_lock, flags);
501 if (arch_clock->clk_deny_idle)
502 arch_clock->clk_deny_idle(clk);
503 spin_unlock_irqrestore(&clockfw_lock, flags);
505 EXPORT_SYMBOL(clk_deny_idle);
507 void clk_allow_idle(struct clk *clk)
511 if (clk == NULL || IS_ERR(clk))
514 spin_lock_irqsave(&clockfw_lock, flags);
515 if (arch_clock->clk_allow_idle)
516 arch_clock->clk_allow_idle(clk);
517 spin_unlock_irqrestore(&clockfw_lock, flags);
519 EXPORT_SYMBOL(clk_allow_idle);
521 void clk_enable_init_clocks(void)
525 list_for_each_entry(clkp, &clocks, node) {
526 if (clkp->flags & ENABLE_ON_INIT)
530 EXPORT_SYMBOL(clk_enable_init_clocks);
532 #ifdef CONFIG_CPU_FREQ
533 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
537 spin_lock_irqsave(&clockfw_lock, flags);
538 if (arch_clock->clk_init_cpufreq_table)
539 arch_clock->clk_init_cpufreq_table(table);
540 spin_unlock_irqrestore(&clockfw_lock, flags);
542 EXPORT_SYMBOL(clk_init_cpufreq_table);
545 /*-------------------------------------------------------------------------*/
547 #ifdef CONFIG_OMAP_RESET_CLOCKS
549 * Disable any unused clocks left on by the bootloader
551 static int __init clk_disable_unused(void)
556 list_for_each_entry(ck, &clocks, node) {
557 if (ck->usecount > 0 ||
558 (ck->flags & (ALWAYS_ENABLED | PARENT_CONTROLS_CLOCK)))
561 if (cpu_class_is_omap1() && ck->enable_reg == 0)
564 spin_lock_irqsave(&clockfw_lock, flags);
565 if (arch_clock->clk_disable_unused)
566 arch_clock->clk_disable_unused(ck);
567 spin_unlock_irqrestore(&clockfw_lock, flags);
572 late_initcall(clk_disable_unused);
575 int __init clk_init(struct clk_functions * custom_clocks)
577 if (!custom_clocks) {
578 printk(KERN_ERR "No custom clock functions registered\n");
582 arch_clock = custom_clocks;
587 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
589 * debugfs support to trace clock tree hierarchy and attributes
591 static struct dentry *clk_debugfs_root;
593 static int clk_debugfs_register_one(struct clk *c)
596 struct dentry *d, *child;
597 struct clk *pa = c->parent;
601 p += sprintf(p, "%s", c->name);
603 sprintf(p, ":%d", c->id);
604 d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
609 d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
614 d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
619 d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
628 list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
629 debugfs_remove(child);
630 debugfs_remove(c->dent);
634 static int clk_debugfs_register(struct clk *c)
637 struct clk *pa = c->parent;
639 if (pa && !pa->dent) {
640 err = clk_debugfs_register(pa);
646 err = clk_debugfs_register_one(c);
653 static int __init clk_debugfs_init(void)
659 d = debugfs_create_dir("clock", NULL);
662 clk_debugfs_root = d;
664 list_for_each_entry(c, &clocks, node) {
665 err = clk_debugfs_register(c);
671 debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
674 late_initcall(clk_debugfs_init);
676 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */