clock.c
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/*
* linux/arch/arm/mach-sa1100/clock.c
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.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 <linux/io.h>
#include <linux/clkdev.h>
#include <mach/hardware.h>
struct clkops {
void (*enable)(struct clk *);
void (*disable)(struct clk *);
};
struct clk {
const struct clkops *ops;
unsigned int enabled;
};
#define DEFINE_CLK(_name, _ops) \
struct clk clk_##_name = { \
.ops = _ops, \
}
static DEFINE_SPINLOCK(clocks_lock);
/* Dummy clk routine to build generic kernel parts that may be using them */
unsigned long clk_get_rate(struct clk *clk)
{
return 0;
}
EXPORT_SYMBOL(clk_get_rate);
static void clk_gpio27_enable(struct clk *clk)
{
/*
* 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(struct clk *clk)
{
TUCR = 0;
GPDR &= ~GPIO_32_768kHz;
GAFR &= ~GPIO_32_768kHz;
}
int clk_enable(struct clk *clk)
{
unsigned long flags;
if (clk) {
spin_lock_irqsave(&clocks_lock, flags);
if (clk->enabled++ == 0)
clk->ops->enable(clk);
spin_unlock_irqrestore(&clocks_lock, flags);
}
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
unsigned long flags;
if (clk) {
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);
const struct clkops clk_gpio27_ops = {
.enable = clk_gpio27_enable,
.disable = clk_gpio27_disable,
};
static DEFINE_CLK(gpio27, &clk_gpio27_ops);
static struct clk_lookup sa11xx_clkregs[] = {
CLKDEV_INIT("sa1111.0", NULL, &clk_gpio27),
CLKDEV_INIT("sa1100-rtc", NULL, NULL),
};
static int __init sa11xx_clk_init(void)
{
clkdev_add_table(sa11xx_clkregs, ARRAY_SIZE(sa11xx_clkregs));
return 0;
}
core_initcall(sa11xx_clk_init);