satip-axe/kernel/arch/arm/mach-sa1100/clock.c
2015-03-26 17:24:57 +01:00

89 lines
1.7 KiB
C

/*
* 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 <mach/hardware.h>
/*
* Very simple clock implementation - we only have one clock to deal with.
*/
struct clk {
unsigned int enabled;
};
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;
static DEFINE_SPINLOCK(clocks_lock);
struct clk *clk_get(struct device *dev, const char *id)
{
const char *devname = dev_name(dev);
return strcmp(devname, "sa1111.0") ? ERR_PTR(-ENOENT) : &clk_gpio27;
}
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_gpio27_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_gpio27_disable();
spin_unlock_irqrestore(&clocks_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
return 3686400;
}
EXPORT_SYMBOL(clk_get_rate);