swh:1:snp:c2847dfd741eae21606027cf29250d1ebcd63fb4
Tip revision: f7160c7573615ec82c691e294cf80d920b5d588d authored by Linus Torvalds on 10 November 2008, 00:36:15 UTC
Linux 2.6.28-rc4
Linux 2.6.28-rc4
Tip revision: f7160c7
clock.c
/*
* linux/arch/arm/plat-omap/clock.c
*
* Copyright (C) 2004 - 2008 Nokia corporation
* Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
*
* Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/clk.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/cpufreq.h>
#include <linux/debugfs.h>
#include <linux/io.h>
#include <mach/clock.h>
static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
static DEFINE_SPINLOCK(clockfw_lock);
static struct clk_functions *arch_clock;
/*-------------------------------------------------------------------------
* Standard clock functions defined in include/linux/clk.h
*-------------------------------------------------------------------------*/
/*
* Returns a clock. Note that we first try to use device id on the bus
* and clock name. If this fails, we try to use clock name only.
*/
struct clk * clk_get(struct device *dev, const char *id)
{
struct clk *p, *clk = ERR_PTR(-ENOENT);
int idno;
if (dev == NULL || dev->bus != &platform_bus_type)
idno = -1;
else
idno = to_platform_device(dev)->id;
mutex_lock(&clocks_mutex);
list_for_each_entry(p, &clocks, node) {
if (p->id == idno &&
strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
clk = p;
goto found;
}
}
list_for_each_entry(p, &clocks, node) {
if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
clk = p;
break;
}
}
found:
mutex_unlock(&clocks_mutex);
return clk;
}
EXPORT_SYMBOL(clk_get);
int clk_enable(struct clk *clk)
{
unsigned long flags;
int ret = 0;
if (clk == NULL || IS_ERR(clk))
return -EINVAL;
spin_lock_irqsave(&clockfw_lock, flags);
if (arch_clock->clk_enable)
ret = arch_clock->clk_enable(clk);
spin_unlock_irqrestore(&clockfw_lock, flags);
return ret;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
unsigned long flags;
if (clk == NULL || IS_ERR(clk))
return;
spin_lock_irqsave(&clockfw_lock, flags);
if (clk->usecount == 0) {
printk(KERN_ERR "Trying disable clock %s with 0 usecount\n",
clk->name);
WARN_ON(1);
goto out;
}
if (arch_clock->clk_disable)
arch_clock->clk_disable(clk);
out:
spin_unlock_irqrestore(&clockfw_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
int clk_get_usecount(struct clk *clk)
{
unsigned long flags;
int ret = 0;
if (clk == NULL || IS_ERR(clk))
return 0;
spin_lock_irqsave(&clockfw_lock, flags);
ret = clk->usecount;
spin_unlock_irqrestore(&clockfw_lock, flags);
return ret;
}
EXPORT_SYMBOL(clk_get_usecount);
unsigned long clk_get_rate(struct clk *clk)
{
unsigned long flags;
unsigned long ret = 0;
if (clk == NULL || IS_ERR(clk))
return 0;
spin_lock_irqsave(&clockfw_lock, flags);
ret = clk->rate;
spin_unlock_irqrestore(&clockfw_lock, flags);
return ret;
}
EXPORT_SYMBOL(clk_get_rate);
void clk_put(struct clk *clk)
{
if (clk && !IS_ERR(clk))
module_put(clk->owner);
}
EXPORT_SYMBOL(clk_put);
/*-------------------------------------------------------------------------
* Optional clock functions defined in include/linux/clk.h
*-------------------------------------------------------------------------*/
long clk_round_rate(struct clk *clk, unsigned long rate)
{
unsigned long flags;
long ret = 0;
if (clk == NULL || IS_ERR(clk))
return ret;
spin_lock_irqsave(&clockfw_lock, flags);
if (arch_clock->clk_round_rate)
ret = arch_clock->clk_round_rate(clk, rate);
spin_unlock_irqrestore(&clockfw_lock, flags);
return ret;
}
EXPORT_SYMBOL(clk_round_rate);
int clk_set_rate(struct clk *clk, unsigned long rate)
{
unsigned long flags;
int ret = -EINVAL;
if (clk == NULL || IS_ERR(clk))
return ret;
spin_lock_irqsave(&clockfw_lock, flags);
if (arch_clock->clk_set_rate)
ret = arch_clock->clk_set_rate(clk, rate);
spin_unlock_irqrestore(&clockfw_lock, flags);
return ret;
}
EXPORT_SYMBOL(clk_set_rate);
int clk_set_parent(struct clk *clk, struct clk *parent)
{
unsigned long flags;
int ret = -EINVAL;
if (clk == NULL || IS_ERR(clk) || parent == NULL || IS_ERR(parent))
return ret;
spin_lock_irqsave(&clockfw_lock, flags);
if (arch_clock->clk_set_parent)
ret = arch_clock->clk_set_parent(clk, parent);
spin_unlock_irqrestore(&clockfw_lock, flags);
return ret;
}
EXPORT_SYMBOL(clk_set_parent);
struct clk *clk_get_parent(struct clk *clk)
{
unsigned long flags;
struct clk * ret = NULL;
if (clk == NULL || IS_ERR(clk))
return ret;
spin_lock_irqsave(&clockfw_lock, flags);
if (arch_clock->clk_get_parent)
ret = arch_clock->clk_get_parent(clk);
spin_unlock_irqrestore(&clockfw_lock, flags);
return ret;
}
EXPORT_SYMBOL(clk_get_parent);
/*-------------------------------------------------------------------------
* OMAP specific clock functions shared between omap1 and omap2
*-------------------------------------------------------------------------*/
unsigned int __initdata mpurate;
/*
* By default we use the rate set by the bootloader.
* You can override this with mpurate= cmdline option.
*/
static int __init omap_clk_setup(char *str)
{
get_option(&str, &mpurate);
if (!mpurate)
return 1;
if (mpurate < 1000)
mpurate *= 1000000;
return 1;
}
__setup("mpurate=", omap_clk_setup);
/* Used for clocks that always have same value as the parent clock */
void followparent_recalc(struct clk *clk)
{
if (clk == NULL || IS_ERR(clk))
return;
clk->rate = clk->parent->rate;
if (unlikely(clk->flags & RATE_PROPAGATES))
propagate_rate(clk);
}
/* Propagate rate to children */
void propagate_rate(struct clk * tclk)
{
struct clk *clkp;
if (tclk == NULL || IS_ERR(tclk))
return;
list_for_each_entry(clkp, &clocks, node) {
if (likely(clkp->parent != tclk))
continue;
if (likely((u32)clkp->recalc))
clkp->recalc(clkp);
}
}
/**
* recalculate_root_clocks - recalculate and propagate all root clocks
*
* Recalculates all root clocks (clocks with no parent), which if the
* clock's .recalc is set correctly, should also propagate their rates.
* Called at init.
*/
void recalculate_root_clocks(void)
{
struct clk *clkp;
list_for_each_entry(clkp, &clocks, node) {
if (unlikely(!clkp->parent) && likely((u32)clkp->recalc))
clkp->recalc(clkp);
}
}
int clk_register(struct clk *clk)
{
if (clk == NULL || IS_ERR(clk))
return -EINVAL;
mutex_lock(&clocks_mutex);
list_add(&clk->node, &clocks);
if (clk->init)
clk->init(clk);
mutex_unlock(&clocks_mutex);
return 0;
}
EXPORT_SYMBOL(clk_register);
void clk_unregister(struct clk *clk)
{
if (clk == NULL || IS_ERR(clk))
return;
mutex_lock(&clocks_mutex);
list_del(&clk->node);
mutex_unlock(&clocks_mutex);
}
EXPORT_SYMBOL(clk_unregister);
void clk_deny_idle(struct clk *clk)
{
unsigned long flags;
if (clk == NULL || IS_ERR(clk))
return;
spin_lock_irqsave(&clockfw_lock, flags);
if (arch_clock->clk_deny_idle)
arch_clock->clk_deny_idle(clk);
spin_unlock_irqrestore(&clockfw_lock, flags);
}
EXPORT_SYMBOL(clk_deny_idle);
void clk_allow_idle(struct clk *clk)
{
unsigned long flags;
if (clk == NULL || IS_ERR(clk))
return;
spin_lock_irqsave(&clockfw_lock, flags);
if (arch_clock->clk_allow_idle)
arch_clock->clk_allow_idle(clk);
spin_unlock_irqrestore(&clockfw_lock, flags);
}
EXPORT_SYMBOL(clk_allow_idle);
void clk_enable_init_clocks(void)
{
struct clk *clkp;
list_for_each_entry(clkp, &clocks, node) {
if (clkp->flags & ENABLE_ON_INIT)
clk_enable(clkp);
}
}
EXPORT_SYMBOL(clk_enable_init_clocks);
#ifdef CONFIG_CPU_FREQ
void clk_init_cpufreq_table(struct cpufreq_frequency_table **table)
{
unsigned long flags;
spin_lock_irqsave(&clockfw_lock, flags);
if (arch_clock->clk_init_cpufreq_table)
arch_clock->clk_init_cpufreq_table(table);
spin_unlock_irqrestore(&clockfw_lock, flags);
}
EXPORT_SYMBOL(clk_init_cpufreq_table);
#endif
/*-------------------------------------------------------------------------*/
#ifdef CONFIG_OMAP_RESET_CLOCKS
/*
* Disable any unused clocks left on by the bootloader
*/
static int __init clk_disable_unused(void)
{
struct clk *ck;
unsigned long flags;
list_for_each_entry(ck, &clocks, node) {
if (ck->usecount > 0 || (ck->flags & ALWAYS_ENABLED) ||
ck->enable_reg == 0)
continue;
spin_lock_irqsave(&clockfw_lock, flags);
if (arch_clock->clk_disable_unused)
arch_clock->clk_disable_unused(ck);
spin_unlock_irqrestore(&clockfw_lock, flags);
}
return 0;
}
late_initcall(clk_disable_unused);
#endif
int __init clk_init(struct clk_functions * custom_clocks)
{
if (!custom_clocks) {
printk(KERN_ERR "No custom clock functions registered\n");
BUG();
}
arch_clock = custom_clocks;
return 0;
}
#if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
/*
* debugfs support to trace clock tree hierarchy and attributes
*/
static struct dentry *clk_debugfs_root;
static int clk_debugfs_register_one(struct clk *c)
{
int err;
struct dentry *d, *child;
struct clk *pa = c->parent;
char s[255];
char *p = s;
p += sprintf(p, "%s", c->name);
if (c->id != 0)
sprintf(p, ":%d", c->id);
d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
if (!d)
return -ENOMEM;
c->dent = d;
d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8 *)&c->usecount);
if (!d) {
err = -ENOMEM;
goto err_out;
}
d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32 *)&c->rate);
if (!d) {
err = -ENOMEM;
goto err_out;
}
d = debugfs_create_x32("flags", S_IRUGO, c->dent, (u32 *)&c->flags);
if (!d) {
err = -ENOMEM;
goto err_out;
}
return 0;
err_out:
d = c->dent;
list_for_each_entry(child, &d->d_subdirs, d_u.d_child)
debugfs_remove(child);
debugfs_remove(c->dent);
return err;
}
static int clk_debugfs_register(struct clk *c)
{
int err;
struct clk *pa = c->parent;
if (pa && !pa->dent) {
err = clk_debugfs_register(pa);
if (err)
return err;
}
if (!c->dent) {
err = clk_debugfs_register_one(c);
if (err)
return err;
}
return 0;
}
static int __init clk_debugfs_init(void)
{
struct clk *c;
struct dentry *d;
int err;
d = debugfs_create_dir("clock", NULL);
if (!d)
return -ENOMEM;
clk_debugfs_root = d;
list_for_each_entry(c, &clocks, node) {
err = clk_debugfs_register(c);
if (err)
goto err_out;
}
return 0;
err_out:
debugfs_remove(clk_debugfs_root); /* REVISIT: Cleanup correctly */
return err;
}
late_initcall(clk_debugfs_init);
#endif /* defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS) */