/* linux/arch/arm/plat-s3c24xx/clock.c
 *
 * Copyright 2004-2005 Simtec Electronics
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * S3C24XX Core clock control support
 *
 * Based on, and code from linux/arch/arm/mach-versatile/clock.c
 **
 **  Copyright (C) 2004 ARM Limited.
 **  Written by Deep Blue Solutions Limited.
 *
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/clk.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#if defined(CONFIG_DEBUG_FS)
#include <linux/debugfs.h>
#endif

#include <mach/hardware.h>
#include <asm/irq.h>

#include <plat/cpu-freq.h>

#include <plat/clock.h>
#include <plat/cpu.h>

#include <linux/serial_core.h>
#include <plat/regs-serial.h> /* for s3c24xx_uart_devs */

/* clock information */

static LIST_HEAD(clocks);

/* We originally used an mutex here, but some contexts (see resume)
 * are calling functions such as clk_set_parent() with IRQs disabled
 * causing an BUG to be triggered.
 */
DEFINE_SPINLOCK(clocks_lock);

/* Global watchdog clock used by arch_wtd_reset() callback */
struct clk *s3c2410_wdtclk;
static int __init s3c_wdt_reset_init(void)
{
	s3c2410_wdtclk = clk_get(NULL, "watchdog");
	if (IS_ERR(s3c2410_wdtclk))
		printk(KERN_WARNING "%s: warning: cannot get watchdog clock\n", __func__);
	return 0;
}
arch_initcall(s3c_wdt_reset_init);

/* enable and disable calls for use with the clk struct */

static int clk_null_enable(struct clk *clk, int enable)
{
	return 0;
}

int clk_enable(struct clk *clk)
{
	unsigned long flags;

	if (IS_ERR(clk) || clk == NULL)
		return -EINVAL;

	clk_enable(clk->parent);

	spin_lock_irqsave(&clocks_lock, flags);

	if ((clk->usage++) == 0)
		(clk->enable)(clk, 1);

	spin_unlock_irqrestore(&clocks_lock, flags);
	return 0;
}

void clk_disable(struct clk *clk)
{
	unsigned long flags;

	if (IS_ERR(clk) || clk == NULL)
		return;

	spin_lock_irqsave(&clocks_lock, flags);

	if ((--clk->usage) == 0)
		(clk->enable)(clk, 0);

	spin_unlock_irqrestore(&clocks_lock, flags);
	clk_disable(clk->parent);
}


unsigned long clk_get_rate(struct clk *clk)
{
	if (IS_ERR_OR_NULL(clk))
		return 0;

	if (clk->rate != 0)
		return clk->rate;

	if (clk->ops != NULL && clk->ops->get_rate != NULL)
		return (clk->ops->get_rate)(clk);

	if (clk->parent != NULL)
		return clk_get_rate(clk->parent);

	return clk->rate;
}

long clk_round_rate(struct clk *clk, unsigned long rate)
{
	if (!IS_ERR_OR_NULL(clk) && clk->ops && clk->ops->round_rate)
		return (clk->ops->round_rate)(clk, rate);

	return rate;
}

int clk_set_rate(struct clk *clk, unsigned long rate)
{
	unsigned long flags;
	int ret;

	if (IS_ERR_OR_NULL(clk))
		return -EINVAL;

	/* We do not default just do a clk->rate = rate as
	 * the clock may have been made this way by choice.
	 */