linux/arch/arm/plat-omap/clock.c

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/*
* linux/arch/arm/plat-omap/clock.c
*
* Copyright (C) 2004 - 2005 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/version.h>
#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 <asm/io.h>
#include <asm/semaphore.h>
#include <asm/arch/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);
BUG_ON(clk->usecount == 0);
if (arch_clock->clk_disable)
arch_clock->clk_disable(clk);
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;
}
/* 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);
}
}
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);
/*-------------------------------------------------------------------------*/
#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;
}