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clock.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;
}

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