linux/arch/arm/mach-pxa/clock.c
Ian Molton 5fedd0afd6 [ARM] clocklib: Allow dynamic alias creation
This patch allows dynamic creation of clock aliases in order to
make it possible to have platform independent clock names for use in
device drivers.

Signed-off-by: Ian Molton <spyro@f2s.com>
2008-08-12 12:54:30 +01:00

153 lines
2.7 KiB
C

/*
* linux/arch/arm/mach-sa1100/clock.c
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/clk.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <mach/pxa2xx-regs.h>
#include <mach/pxa2xx-gpio.h>
#include <mach/hardware.h>
#include "devices.h"
#include "generic.h"
#include "clock.h"
static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
static DEFINE_SPINLOCK(clocks_lock);
static struct clk *clk_lookup(struct device *dev, const char *id)
{
struct clk *p;
list_for_each_entry(p, &clocks, node)
if (strcmp(id, p->name) == 0 && p->dev == dev)
return p;
return NULL;
}
struct clk *clk_get(struct device *dev, const char *id)
{
struct clk *p, *clk = ERR_PTR(-ENOENT);
mutex_lock(&clocks_mutex);
p = clk_lookup(dev, id);
if (!p)
p = clk_lookup(NULL, id);
if (p)
clk = p;
mutex_unlock(&clocks_mutex);
if (!IS_ERR(clk) && clk->ops == NULL)
clk = clk->other;
return clk;
}
EXPORT_SYMBOL(clk_get);
void clk_put(struct clk *clk)
{
}
EXPORT_SYMBOL(clk_put);
int clk_enable(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clocks_lock, flags);
if (clk->enabled++ == 0)
clk->ops->enable(clk);
spin_unlock_irqrestore(&clocks_lock, flags);
if (clk->delay)
udelay(clk->delay);
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
unsigned long flags;
WARN_ON(clk->enabled == 0);
spin_lock_irqsave(&clocks_lock, flags);
if (--clk->enabled == 0)
clk->ops->disable(clk);
spin_unlock_irqrestore(&clocks_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
unsigned long rate;
rate = clk->rate;
if (clk->ops->getrate)
rate = clk->ops->getrate(clk);
return rate;
}
EXPORT_SYMBOL(clk_get_rate);
void clk_cken_enable(struct clk *clk)
{
CKEN |= 1 << clk->cken;
}
void clk_cken_disable(struct clk *clk)
{
CKEN &= ~(1 << clk->cken);
}
const struct clkops clk_cken_ops = {
.enable = clk_cken_enable,
.disable = clk_cken_disable,
};
void clks_register(struct clk *clks, size_t num)
{
int i;
mutex_lock(&clocks_mutex);
for (i = 0; i < num; i++)
list_add(&clks[i].node, &clocks);
mutex_unlock(&clocks_mutex);
}
int clk_add_alias(char *alias, struct device *alias_dev, char *id,
struct device *dev)
{
struct clk *r = clk_lookup(dev, id);
struct clk *new;
if (!r)
return -ENODEV;
new = kzalloc(sizeof(struct clk), GFP_KERNEL);
if (!new)
return -ENOMEM;
new->name = alias;
new->dev = alias_dev;
new->other = r;
mutex_lock(&clocks_mutex);
list_add(&new->node, &clocks);
mutex_unlock(&clocks_mutex);
return 0;
}