2 * linux/arch/arm/plat-omap/clock.c
4 * Copyright (C) 2004 - 2005 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/version.h>
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/list.h>
18 #include <linux/errno.h>
19 #include <linux/err.h>
20 #include <linux/string.h>
21 #include <linux/clk.h>
22 #include <linux/mutex.h>
23 #include <linux/platform_device.h>
24 #include <linux/cpufreq.h>
28 #include <asm/arch/clock.h>
30 static LIST_HEAD(clocks);
31 static DEFINE_MUTEX(clocks_mutex);
32 static DEFINE_SPINLOCK(clockfw_lock);
34 static struct clk_functions *arch_clock;
36 #ifdef CONFIG_PM_DEBUG
38 static void print_parents(struct clk *clk)
43 list_for_each_entry(p, &clocks, node) {
44 if (p->parent == clk && p->usecount) {
45 if (!clk->usecount && !printed) {
46 printk("MISMATCH: %s\n", clk->name);
49 printk("\t%-15s\n", p->name);
54 void clk_print_usecounts(void)
59 spin_lock_irqsave(&clockfw_lock, flags);
60 list_for_each_entry(p, &clocks, node) {
62 printk("%-15s: %d\n", p->name, p->usecount);
66 spin_unlock_irqrestore(&clockfw_lock, flags);
71 /*-------------------------------------------------------------------------
72 * Standard clock functions defined in include/linux/clk.h
73 *-------------------------------------------------------------------------*/
76 * Returns a clock. Note that we first try to use device id on the bus
77 * and clock name. If this fails, we try to use clock name only.
79 struct clk * clk_get(struct device *dev, const char *id)
81 struct clk *p, *clk = ERR_PTR(-ENOENT);
84 if (dev == NULL || dev->bus != &platform_bus_type)
87 idno = to_platform_device(dev)->id;
89 mutex_lock(&clocks_mutex);
91 list_for_each_entry(p, &clocks, node) {
93 strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
99 list_for_each_entry(p, &clocks, node) {
100 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
107 mutex_unlock(&clocks_mutex);
111 EXPORT_SYMBOL(clk_get);
113 int clk_enable(struct clk *clk)
118 if (clk == NULL || IS_ERR(clk))
121 spin_lock_irqsave(&clockfw_lock, flags);
122 if (arch_clock->clk_enable)
123 ret = arch_clock->clk_enable(clk);
124 spin_unlock_irqrestore(&clockfw_lock, flags);
128 EXPORT_SYMBOL(clk_enable);
130 void clk_disable(struct clk *clk)
134 if (clk == NULL || IS_ERR(clk))
137 spin_lock_irqsave(&clockfw_lock, flags);
138 if (clk->usecount == 0) {
139 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
145 if (arch_clock->clk_disable)
146 arch_clock->clk_disable(clk);
149 spin_unlock_irqrestore(&clockfw_lock, flags);
151 EXPORT_SYMBOL(clk_disable);
153 int clk_get_usecount(struct clk *clk)
158 if (clk == NULL || IS_ERR(clk))
161 spin_lock_irqsave(&clockfw_lock, flags);
163 spin_unlock_irqrestore(&clockfw_lock, flags);
167 EXPORT_SYMBOL(clk_get_usecount);
169 unsigned long clk_get_rate(struct clk *clk)
172 unsigned long ret = 0;
174 if (clk == NULL || IS_ERR(clk))
177 spin_lock_irqsave(&clockfw_lock, flags);
179 spin_unlock_irqrestore(&clockfw_lock, flags);
183 EXPORT_SYMBOL(clk_get_rate);
185 void clk_put(struct clk *clk)
187 if (clk && !IS_ERR(clk))
188 module_put(clk->owner);
190 EXPORT_SYMBOL(clk_put);
192 /*-------------------------------------------------------------------------
193 * Optional clock functions defined in include/linux/clk.h
194 *-------------------------------------------------------------------------*/
196 long clk_round_rate(struct clk *clk, unsigned long rate)
201 if (clk == NULL || IS_ERR(clk))
204 spin_lock_irqsave(&clockfw_lock, flags);
205 if (arch_clock->clk_round_rate)
206 ret = arch_clock->clk_round_rate(clk, rate);
207 spin_unlock_irqrestore(&clockfw_lock, flags);
211 EXPORT_SYMBOL(clk_round_rate);
213 int clk_set_rate(struct clk *clk, unsigned long rate)
218 if (clk == NULL || IS_ERR(clk))
221 spin_lock_irqsave(&clockfw_lock, flags);
222 if (arch_clock->clk_set_rate)
223 ret = arch_clock->clk_set_rate(clk, rate);
224 spin_unlock_irqrestore(&clockfw_lock, flags);
228 EXPORT_SYMBOL(clk_set_rate);
230 int clk_set_parent(struct clk *clk, struct clk *parent)
235 if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
238 spin_lock_irqsave(&clockfw_lock, flags);
239 if (arch_clock->clk_set_parent)
240 ret = arch_clock->clk_set_parent(clk, parent);
241 spin_unlock_irqrestore(&clockfw_lock, flags);
245 EXPORT_SYMBOL(clk_set_parent);
247 struct clk *clk_get_parent(struct clk *clk)
250 struct clk * ret = NULL;
252 if (clk == NULL || IS_ERR(clk))
255 spin_lock_irqsave(&clockfw_lock, flags);
256 if (arch_clock->clk_get_parent)
257 ret = arch_clock->clk_get_parent(clk);
258 spin_unlock_irqrestore(&clockfw_lock, flags);
262 EXPORT_SYMBOL(clk_get_parent);
264 /*-------------------------------------------------------------------------
265 * OMAP specific clock functions shared between omap1 and omap2
266 *-------------------------------------------------------------------------*/
268 unsigned int __initdata mpurate;
271 * By default we use the rate set by the bootloader.
272 * You can override this with mpurate= cmdline option.
274 static int __init omap_clk_setup(char *str)
276 get_option(&str, &mpurate);
286 __setup("mpurate=", omap_clk_setup);
288 /* Used for clocks that always have same value as the parent clock */
289 void followparent_recalc(struct clk *clk)
291 if (clk == NULL || IS_ERR(clk))
294 clk->rate = clk->parent->rate;
295 if (unlikely(clk->flags & RATE_PROPAGATES))
299 /* Propagate rate to children */
300 void propagate_rate(struct clk * tclk)
304 if (tclk == NULL || IS_ERR(tclk))
307 list_for_each_entry(clkp, &clocks, node) {
308 if (likely(clkp->parent != tclk))
310 if (likely((u32)clkp->recalc))
316 * recalculate_root_clocks - recalculate and propagate all root clocks
318 * Recalculates all root clocks (clocks with no parent), which if the
319 * clock's .recalc is set correctly, should also propagate their rates.
322 void recalculate_root_clocks(void)
326 list_for_each_entry(clkp, &clocks, node) {
327 if (unlikely(!clkp->parent) && likely((u32)clkp->recalc))
332 int clk_register(struct clk *clk)
334 if (clk == NULL || IS_ERR(clk))
337 mutex_lock(&clocks_mutex);
338 list_add(&clk->node, &clocks);
341 mutex_unlock(&clocks_mutex);
345 EXPORT_SYMBOL(clk_register);
347 void clk_unregister(struct clk *clk)
349 if (clk == NULL || IS_ERR(clk))
352 mutex_lock(&clocks_mutex);
353 list_del(&clk->node);
354 mutex_unlock(&clocks_mutex);
356 EXPORT_SYMBOL(clk_unregister);
358 void clk_deny_idle(struct clk *clk)
362 if (clk == NULL || IS_ERR(clk))
365 spin_lock_irqsave(&clockfw_lock, flags);
366 if (arch_clock->clk_deny_idle)
367 arch_clock->clk_deny_idle(clk);
368 spin_unlock_irqrestore(&clockfw_lock, flags);
370 EXPORT_SYMBOL(clk_deny_idle);
372 void clk_allow_idle(struct clk *clk)
376 if (clk == NULL || IS_ERR(clk))
379 spin_lock_irqsave(&clockfw_lock, flags);
380 if (arch_clock->clk_allow_idle)
381 arch_clock->clk_allow_idle(clk);
382 spin_unlock_irqrestore(&clockfw_lock, flags);
384 EXPORT_SYMBOL(clk_allow_idle);
386 void clk_enable_init_clocks(void)
390 list_for_each_entry(clkp, &clocks, node) {
391 if (clkp->flags & ENABLE_ON_INIT)
395 EXPORT_SYMBOL(clk_enable_init_clocks);
397 #ifdef CONFIG_CPU_FREQ
398 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
402 spin_lock_irqsave(&clockfw_lock, flags);
403 if (arch_clock->clk_init_cpufreq_table)
404 arch_clock->clk_init_cpufreq_table(table);
405 spin_unlock_irqrestore(&clockfw_lock, flags);
407 EXPORT_SYMBOL(clk_init_cpufreq_table);
410 /*-------------------------------------------------------------------------*/
412 #ifdef CONFIG_OMAP_RESET_CLOCKS
414 * Disable any unused clocks left on by the bootloader
416 static int __init clk_disable_unused(void)
421 list_for_each_entry(ck, &clocks, node) {
422 if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
426 spin_lock_irqsave(&clockfw_lock, flags);
427 if (arch_clock->clk_disable_unused)
428 arch_clock->clk_disable_unused(ck);
429 spin_unlock_irqrestore(&clockfw_lock, flags);
434 late_initcall(clk_disable_unused);
437 int __init clk_init(struct clk_functions * custom_clocks)
439 if (!custom_clocks) {
440 printk(KERN_ERR "No custom clock functions registered\n");
444 arch_clock = custom_clocks;