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 *-------------------------------------------------------------------------*/
39 /* This functions is moved to arch/arm/common/clkdev.c. For OMAP4 since
40 * clock framework is not up , it is defined here to avoid rework in
41 * every driver. Also dummy prcm reset function is added */
43 /* Dummy hooks only for OMAP4.For rest OMAPs, common clkdev is used */
44 #if defined(CONFIG_ARCH_OMAP4)
45 struct clk *clk_get(struct device *dev, const char *id)
49 EXPORT_SYMBOL(clk_get);
51 void clk_put(struct clk *clk)
54 EXPORT_SYMBOL(clk_put);
56 void omap2_clk_prepare_for_reboot(void)
59 EXPORT_SYMBOL(omap2_clk_prepare_for_reboot);
61 void omap_prcm_arch_reset(char mode)
64 EXPORT_SYMBOL(omap_prcm_arch_reset);
66 int clk_enable(struct clk *clk)
70 if (cpu_is_omap44xx())
71 /* OMAP4 clk framework not supported yet */
74 if (clk == NULL || IS_ERR(clk))
77 spin_lock_irqsave(&clockfw_lock, flags);
78 if (arch_clock->clk_enable)
79 ret = arch_clock->clk_enable(clk);
80 spin_unlock_irqrestore(&clockfw_lock, flags);
84 EXPORT_SYMBOL(clk_enable);
86 void clk_disable(struct clk *clk)
90 if (clk == NULL || IS_ERR(clk))
93 spin_lock_irqsave(&clockfw_lock, flags);
94 if (clk->usecount == 0) {
95 printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
101 if (arch_clock->clk_disable)
102 arch_clock->clk_disable(clk);
105 spin_unlock_irqrestore(&clockfw_lock, flags);
107 EXPORT_SYMBOL(clk_disable);
109 unsigned long clk_get_rate(struct clk *clk)
112 unsigned long ret = 0;
114 if (clk == NULL || IS_ERR(clk))
117 spin_lock_irqsave(&clockfw_lock, flags);
119 spin_unlock_irqrestore(&clockfw_lock, flags);
123 EXPORT_SYMBOL(clk_get_rate);
125 /*-------------------------------------------------------------------------
126 * Optional clock functions defined in include/linux/clk.h
127 *-------------------------------------------------------------------------*/
129 long clk_round_rate(struct clk *clk, unsigned long rate)
134 if (clk == NULL || IS_ERR(clk))
137 spin_lock_irqsave(&clockfw_lock, flags);
138 if (arch_clock->clk_round_rate)
139 ret = arch_clock->clk_round_rate(clk, rate);
140 spin_unlock_irqrestore(&clockfw_lock, flags);
144 EXPORT_SYMBOL(clk_round_rate);
146 int clk_set_rate(struct clk *clk, unsigned long rate)
151 if (clk == NULL || IS_ERR(clk))
154 spin_lock_irqsave(&clockfw_lock, flags);
155 if (arch_clock->clk_set_rate)
156 ret = arch_clock->clk_set_rate(clk, rate);
159 clk->rate = clk->recalc(clk);
162 spin_unlock_irqrestore(&clockfw_lock, flags);
166 EXPORT_SYMBOL(clk_set_rate);
168 int clk_set_parent(struct clk *clk, struct clk *parent)
173 if (cpu_is_omap44xx())
174 /* OMAP4 clk framework not supported yet */
176 if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
179 spin_lock_irqsave(&clockfw_lock, flags);
180 if (clk->usecount == 0) {
181 if (arch_clock->clk_set_parent)
182 ret = arch_clock->clk_set_parent(clk, parent);
185 clk->rate = clk->recalc(clk);
190 spin_unlock_irqrestore(&clockfw_lock, flags);
194 EXPORT_SYMBOL(clk_set_parent);
196 struct clk *clk_get_parent(struct clk *clk)
200 EXPORT_SYMBOL(clk_get_parent);
202 /*-------------------------------------------------------------------------
203 * OMAP specific clock functions shared between omap1 and omap2
204 *-------------------------------------------------------------------------*/
206 unsigned int __initdata mpurate;
209 * By default we use the rate set by the bootloader.
210 * You can override this with mpurate= cmdline option.
212 static int __init omap_clk_setup(char *str)
214 get_option(&str, &mpurate);
224 __setup("mpurate=", omap_clk_setup);
226 /* Used for clocks that always have same value as the parent clock */
227 unsigned long followparent_recalc(struct clk *clk)
229 return clk->parent->rate;
232 void clk_reparent(struct clk *child, struct clk *parent)
234 list_del_init(&child->sibling);
236 list_add(&child->sibling, &parent->children);
237 child->parent = parent;
239 /* now do the debugfs renaming to reattach the child
240 to the proper parent */
243 /* Propagate rate to children */
244 void propagate_rate(struct clk * tclk)
248 list_for_each_entry(clkp, &tclk->children, sibling) {
250 clkp->rate = clkp->recalc(clkp);
251 propagate_rate(clkp);
255 static LIST_HEAD(root_clks);
258 * recalculate_root_clocks - recalculate and propagate all root clocks
260 * Recalculates all root clocks (clocks with no parent), which if the
261 * clock's .recalc is set correctly, should also propagate their rates.
264 void recalculate_root_clocks(void)
268 list_for_each_entry(clkp, &root_clks, sibling) {
270 clkp->rate = clkp->recalc(clkp);
271 propagate_rate(clkp);
276 * clk_preinit - initialize any fields in the struct clk before clk init
277 * @clk: struct clk * to initialize
279 * Initialize any struct clk fields needed before normal clk initialization
280 * can run. No return value.
282 void clk_preinit(struct clk *clk)
284 INIT_LIST_HEAD(&clk->children);
287 int clk_register(struct clk *clk)
289 if (clk == NULL || IS_ERR(clk))
293 * trap out already registered clocks
295 if (clk->node.next || clk->node.prev)
298 mutex_lock(&clocks_mutex);
300 list_add(&clk->sibling, &clk->parent->children);
302 list_add(&clk->sibling, &root_clks);
304 list_add(&clk->node, &clocks);
307 mutex_unlock(&clocks_mutex);
311 EXPORT_SYMBOL(clk_register);
313 void clk_unregister(struct clk *clk)
315 if (clk == NULL || IS_ERR(clk))
318 mutex_lock(&clocks_mutex);
319 list_del(&clk->sibling);
320 list_del(&clk->node);
321 mutex_unlock(&clocks_mutex);
323 EXPORT_SYMBOL(clk_unregister);
325 void clk_enable_init_clocks(void)
329 list_for_each_entry(clkp, &clocks, node) {
330 if (clkp->flags & ENABLE_ON_INIT)
334 EXPORT_SYMBOL(clk_enable_init_clocks);
339 static int clkll_enable_null(struct clk *clk)
344 static void clkll_disable_null(struct clk *clk)
348 const struct clkops clkops_null = {
349 .enable = clkll_enable_null,
350 .disable = clkll_disable_null,
353 #ifdef CONFIG_CPU_FREQ
354 void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
358 spin_lock_irqsave(&clockfw_lock, flags);
359 if (arch_clock->clk_init_cpufreq_table)
360 arch_clock->clk_init_cpufreq_table(table);
361 spin_unlock_irqrestore(&clockfw_lock, flags);
363 EXPORT_SYMBOL(clk_init_cpufreq_table);
366 /*-------------------------------------------------------------------------*/
368 #ifdef CONFIG_OMAP_RESET_CLOCKS
370 * Disable any unused clocks left on by the bootloader
372 static int __init clk_disable_unused(void)
377 list_for_each_entry(ck, &clocks, node) {
378 if (ck->ops == &clkops_null)
381 if (ck->usecount > 0 || ck->enable_reg == 0)
384 spin_lock_irqsave(&clockfw_lock, flags);
385 if (arch_clock->clk_disable_unused)
386 arch_clock->clk_disable_unused(ck);
387 spin_unlock_irqrestore(&clockfw_lock, flags);
392 late_initcall(clk_disable_unused);
395 int __init clk_init(struct clk_functions * custom_clocks)
397 if (!custom_clocks) {
398 printk(KERN_ERR "No custom clock functions registered\n");
402 arch_clock = custom_clocks;
407 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
409 * debugfs support to trace clock tree hierarchy and attributes
411 static struct dentry *clk_debugfs_root;
413 static int clk_debugfs_register_one(struct clk *c)
416 struct dentry *d, *child;
417 struct clk *pa = c->parent;
421 p += sprintf(p, "%s", c->name);
423 sprintf(p, ":%d", c->id);
424 d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
429 d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
434 d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
439 d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
448 list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
449 debugfs_remove(child);
450 debugfs_remove(c->dent);
454 static int clk_debugfs_register(struct clk *c)
457 struct clk *pa = c->parent;
459 if (pa && !pa->dent) {
460 err = clk_debugfs_register(pa);
466 err = clk_debugfs_register_one(c);
473 static int __init clk_debugfs_init(void)
479 d = debugfs_create_dir("clock", NULL);
482 clk_debugfs_root = d;
484 list_for_each_entry(c, &clocks, node) {
485 err = clk_debugfs_register(c);
491 debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
494 late_initcall(clk_debugfs_init);
496 #endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */