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>
27 #include <mach/clock.h>
29 static LIST_HEAD(clocks);
30 static DEFINE_MUTEX(clocks_mutex);
31 static DEFINE_SPINLOCK(clockfw_lock);
33 static struct clk_functions *arch_clock;
35 /*-------------------------------------------------------------------------
36 * Standard clock functions defined in include/linux/clk.h
37 *-------------------------------------------------------------------------*/
40 * Returns a clock. Note that we first try to use device id on the bus
41 * and clock name. If this fails, we try to use clock name only.
43 struct clk * clk_get(struct device *dev, const char *id)
45 struct clk *p, *clk = ERR_PTR(-ENOENT);
48 if (dev == NULL || dev->bus != &platform_bus_type)
51 idno = to_platform_device(dev)->id;
53 mutex_lock(&clocks_mutex);
55 list_for_each_entry(p, &clocks, node) {
56 if (p->id == idno && strcmp(id, p->name) == 0) {
62 list_for_each_entry(p, &clocks, node) {
63 if (strcmp(id, p->name) == 0) {
70 mutex_unlock(&clocks_mutex);
74 EXPORT_SYMBOL(clk_get);
76 int clk_enable(struct clk *clk)
81 if (clk == NULL || IS_ERR(clk))
84 spin_lock_irqsave(&clockfw_lock, flags);
85 if (arch_clock->clk_enable)
86 ret = arch_clock->clk_enable(clk);
87 spin_unlock_irqrestore(&clockfw_lock, flags);
91 EXPORT_SYMBOL(clk_enable);
93 void clk_disable(struct clk *clk)
97 if (clk == NULL || IS_ERR(clk))
100 spin_lock_irqsave(&clockfw_lock, flags);
101 if (clk->usecount == 0) {
102 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
108 if (arch_clock->clk_disable)
109 arch_clock->clk_disable(clk);
112 spin_unlock_irqrestore(&clockfw_lock, flags);
114 EXPORT_SYMBOL(clk_disable);
116 int clk_get_usecount(struct clk *clk)
121 if (clk == NULL || IS_ERR(clk))
124 spin_lock_irqsave(&clockfw_lock, flags);
126 spin_unlock_irqrestore(&clockfw_lock, flags);
130 EXPORT_SYMBOL(clk_get_usecount);
132 unsigned long clk_get_rate(struct clk *clk)
135 unsigned long ret = 0;
137 if (clk == NULL || IS_ERR(clk))
140 spin_lock_irqsave(&clockfw_lock, flags);
142 spin_unlock_irqrestore(&clockfw_lock, flags);
146 EXPORT_SYMBOL(clk_get_rate);
148 void clk_put(struct clk *clk)
151 EXPORT_SYMBOL(clk_put);
153 /*-------------------------------------------------------------------------
154 * Optional clock functions defined in include/linux/clk.h
155 *-------------------------------------------------------------------------*/
157 long clk_round_rate(struct clk *clk, unsigned long rate)
162 if (clk == NULL || IS_ERR(clk))
165 spin_lock_irqsave(&clockfw_lock, flags);
166 if (arch_clock->clk_round_rate)
167 ret = arch_clock->clk_round_rate(clk, rate);
168 spin_unlock_irqrestore(&clockfw_lock, flags);
172 EXPORT_SYMBOL(clk_round_rate);
174 int clk_set_rate(struct clk *clk, unsigned long rate)
179 if (clk == NULL || IS_ERR(clk))
182 spin_lock_irqsave(&clockfw_lock, flags);
183 if (arch_clock->clk_set_rate)
184 ret = arch_clock->clk_set_rate(clk, rate);
185 if (ret == 0 && (clk->flags & RATE_PROPAGATES))
187 spin_unlock_irqrestore(&clockfw_lock, flags);
191 EXPORT_SYMBOL(clk_set_rate);
193 int clk_set_parent(struct clk *clk, struct clk *parent)
198 if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
201 spin_lock_irqsave(&clockfw_lock, flags);
202 if (arch_clock->clk_set_parent)
203 ret = arch_clock->clk_set_parent(clk, parent);
204 if (ret == 0 && (clk->flags & RATE_PROPAGATES))
206 spin_unlock_irqrestore(&clockfw_lock, flags);
210 EXPORT_SYMBOL(clk_set_parent);
212 struct clk *clk_get_parent(struct clk *clk)
216 EXPORT_SYMBOL(clk_get_parent);
218 /*-------------------------------------------------------------------------
219 * OMAP specific clock functions shared between omap1 and omap2
220 *-------------------------------------------------------------------------*/
222 unsigned int __initdata mpurate;
225 * By default we use the rate set by the bootloader.
226 * You can override this with mpurate= cmdline option.
228 static int __init omap_clk_setup(char *str)
230 get_option(&str, &mpurate);
240 __setup("mpurate=", omap_clk_setup);
242 /* Used for clocks that always have same value as the parent clock */
243 void followparent_recalc(struct clk *clk)
245 if (clk == NULL || IS_ERR(clk))
248 clk->rate = clk->parent->rate;
251 /* Propagate rate to children */
252 void propagate_rate(struct clk * tclk)
256 if (tclk == NULL || IS_ERR(tclk))
259 list_for_each_entry(clkp, &clocks, node) {
260 if (likely(clkp->parent != tclk))
264 if (clkp->flags & RATE_PROPAGATES)
265 propagate_rate(clkp);
270 * recalculate_root_clocks - recalculate and propagate all root clocks
272 * Recalculates all root clocks (clocks with no parent), which if the
273 * clock's .recalc is set correctly, should also propagate their rates.
276 void recalculate_root_clocks(void)
280 list_for_each_entry(clkp, &clocks, node) {
284 if (clkp->flags & RATE_PROPAGATES)
285 propagate_rate(clkp);
290 int clk_register(struct clk *clk)
292 if (clk == NULL || IS_ERR(clk))
295 mutex_lock(&clocks_mutex);
296 list_add(&clk->node, &clocks);
299 mutex_unlock(&clocks_mutex);
303 EXPORT_SYMBOL(clk_register);
305 void clk_unregister(struct clk *clk)
307 if (clk == NULL || IS_ERR(clk))
310 mutex_lock(&clocks_mutex);
311 list_del(&clk->node);
312 mutex_unlock(&clocks_mutex);
314 EXPORT_SYMBOL(clk_unregister);
316 void clk_enable_init_clocks(void)
320 list_for_each_entry(clkp, &clocks, node) {
321 if (clkp->flags & ENABLE_ON_INIT)
325 EXPORT_SYMBOL(clk_enable_init_clocks);
330 static int clkll_enable_null(struct clk *clk)
335 static void clkll_disable_null(struct clk *clk)
339 const struct clkops clkops_null = {
340 .enable = clkll_enable_null,
341 .disable = clkll_disable_null,
344 #ifdef CONFIG_CPU_FREQ
345 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
349 spin_lock_irqsave(&clockfw_lock, flags);
350 if (arch_clock->clk_init_cpufreq_table)
351 arch_clock->clk_init_cpufreq_table(table);
352 spin_unlock_irqrestore(&clockfw_lock, flags);
354 EXPORT_SYMBOL(clk_init_cpufreq_table);
357 /*-------------------------------------------------------------------------*/
359 #ifdef CONFIG_OMAP_RESET_CLOCKS
361 * Disable any unused clocks left on by the bootloader
363 static int __init clk_disable_unused(void)
368 list_for_each_entry(ck, &clocks, node) {
369 if (ck->ops == &clkops_null)
372 if (ck->usecount > 0 || ck->enable_reg == 0)
375 spin_lock_irqsave(&clockfw_lock, flags);
376 if (arch_clock->clk_disable_unused)
377 arch_clock->clk_disable_unused(ck);
378 spin_unlock_irqrestore(&clockfw_lock, flags);
383 late_initcall(clk_disable_unused);
386 int __init clk_init(struct clk_functions * custom_clocks)
388 if (!custom_clocks) {
389 printk(KERN_ERR "No custom clock functions registered\n");
393 arch_clock = custom_clocks;
398 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
400 * debugfs support to trace clock tree hierarchy and attributes
402 static struct dentry *clk_debugfs_root;
404 static int clk_debugfs_register_one(struct clk *c)
407 struct dentry *d, *child;
408 struct clk *pa = c->parent;
412 p += sprintf(p, "%s", c->name);
414 sprintf(p, ":%d", c->id);
415 d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
420 d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
425 d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
430 d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
439 list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
440 debugfs_remove(child);
441 debugfs_remove(c->dent);
445 static int clk_debugfs_register(struct clk *c)
448 struct clk *pa = c->parent;
450 if (pa && !pa->dent) {
451 err = clk_debugfs_register(pa);
457 err = clk_debugfs_register_one(c);
464 static int __init clk_debugfs_init(void)
470 d = debugfs_create_dir("clock", NULL);
473 clk_debugfs_root = d;
475 list_for_each_entry(c, &clocks, node) {
476 err = clk_debugfs_register(c);
482 debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
485 late_initcall(clk_debugfs_init);
487 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */