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/*
* 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/mutex.h>
#include <asm/arch/hardware.h>
/*
* Very simple clock implementation - we only have one clock to
* deal with at the moment, so we only match using the "name".
*/
struct clk {
struct list_head node;
unsigned long rate;
const char *name;
unsigned int enabled;
void (*enable)(void);
void (*disable)(void);
};
static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
static DEFINE_SPINLOCK(clocks_lock);
struct clk *clk_get(struct device *dev, const char *id)
{
struct clk *p, *clk = ERR_PTR(-ENOENT);
mutex_lock(&clocks_mutex);
list_for_each_entry(p, &clocks, node) {
if (strcmp(id, p->name) == 0) {
clk = p;
break;
}
}
mutex_unlock(&clocks_mutex);
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->enable();
spin_unlock_irqrestore(&clocks_lock, flags);
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->disable();
spin_unlock_irqrestore(&clocks_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
static void clk_gpio27_enable(void)
{
/*
* First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111:
* (SA-1110 Developer's Manual, section 9.1.2.1)
*/
GAFR |= GPIO_32_768kHz;
GPDR |= GPIO_32_768kHz;
TUCR = TUCR_3_6864MHz;
}
static void clk_gpio27_disable(void)
{
TUCR = 0;
GPDR &= ~GPIO_32_768kHz;
GAFR &= ~GPIO_32_768kHz;
}
static struct clk clk_gpio27 = {
.name = "SA1111_CLK",
.rate = 3686400,
.enable = clk_gpio27_enable,
.disable = clk_gpio27_disable,
};
int clk_register(struct clk *clk)
{
mutex_lock(&clocks_mutex);
list_add(&clk->node, &clocks);
mutex_unlock(&clocks_mutex);
return 0;
}
EXPORT_SYMBOL(clk_register);
void clk_unregister(struct clk *clk)
{
mutex_lock(&clocks_mutex);
list_del(&clk->node);
mutex_unlock(&clocks_mutex);
}
EXPORT_SYMBOL(clk_unregister);
static int __init clk_init(void)
{
clk_register(&clk_gpio27);
return 0;
}
arch_initcall(clk_init);
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