arch/arm/plat-s3c24xx/clock.c - kernel/msm-4.9 - Gitiles

 /* linux/arch/arm/plat-s3c24xx/clock.c
  *
  * Copyright (c) 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/sysdev.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/clk.h>
 #include <linux/mutex.h>
 #include <linux/delay.h>

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

 #include <asm/arch/regs-clock.h>
 #include <asm/arch/regs-gpio.h>

 #include <asm/plat-s3c24xx/clock.h>
 #include <asm/plat-s3c24xx/cpu.h>

 /* clock information */

 static LIST_HEAD(clocks);

 DEFINE_MUTEX(clocks_mutex);

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

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

 /* Clock API calls */

 struct clk *clk_get(struct device *dev, const char *id)
 {
 	struct clk *p;
 	struct clk *clk = ERR_PTR(-ENOENT);
 	int idno;

 	if (dev == NULL || dev->bus != &platform_bus_type)
 		idno = -1;
 	else
 		idno = to_platform_device(dev)->id;

 	mutex_lock(&clocks_mutex);

 	list_for_each_entry(p, &clocks, list) {
 		if (p->id == idno &&
 		    strcmp(id, p->name) == 0 &&
 		    try_module_get(p->owner)) {
 			clk = p;
 			break;
 		}
 	}

 	/* check for the case where a device was supplied, but the
 	 * clock that was being searched for is not device specific */

 	if (IS_ERR(clk)) {
 		list_for_each_entry(p, &clocks, list) {
 			if (p->id == -1 && strcmp(id, p->name) == 0 &&
 			    try_module_get(p->owner)) {
 				clk = p;
 				break;
 			}
 		}
 	}

 	mutex_unlock(&clocks_mutex);
 	return clk;
 }

 void clk_put(struct clk *clk)
 {
 	module_put(clk->owner);
 }

 int clk_enable(struct clk *clk)
 {
 	if (IS_ERR(clk) || clk == NULL)
 		return -EINVAL;

 	clk_enable(clk->parent);

 	mutex_lock(&clocks_mutex);

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

 	mutex_unlock(&clocks_mutex);
 	return 0;
 }

 void clk_disable(struct clk *clk)
 {
 	if (IS_ERR(clk) || clk == NULL)
 		return;

 	mutex_lock(&clocks_mutex);

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

 	mutex_unlock(&clocks_mutex);
 	clk_disable(clk->parent);
 }


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

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

 	if (clk->get_rate != NULL)
 		return (clk->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(clk) && clk->round_rate)
 		return (clk->round_rate)(clk, rate);

 	return rate;
 }

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

 	if (IS_ERR(clk))
 		return -EINVAL;

 	mutex_lock(&clocks_mutex);
 	ret = (clk->set_rate)(clk, rate);
 	mutex_unlock(&clocks_mutex);

 	return ret;
 }

 struct clk *clk_get_parent(struct clk *clk)
 {
 	return clk->parent;
 }

 int clk_set_parent(struct clk *clk, struct clk *parent)
 {
 	int ret = 0;

 	if (IS_ERR(clk))
 		return -EINVAL;

 	mutex_lock(&clocks_mutex);

 	if (clk->set_parent)
 		ret = (clk->set_parent)(clk, parent);

 	mutex_unlock(&clocks_mutex);

 	return ret;
 }

 EXPORT_SYMBOL(clk_get);
 EXPORT_SYMBOL(clk_put);
 EXPORT_SYMBOL(clk_enable);
 EXPORT_SYMBOL(clk_disable);
 EXPORT_SYMBOL(clk_get_rate);
 EXPORT_SYMBOL(clk_round_rate);
 EXPORT_SYMBOL(clk_set_rate);
 EXPORT_SYMBOL(clk_get_parent);
 EXPORT_SYMBOL(clk_set_parent);

 /* base clocks */

 struct clk clk_xtal = {
 	.name		= "xtal",
 	.id		= -1,
 	.rate		= 0,
 	.parent		= NULL,
 	.ctrlbit	= 0,
 };

 struct clk clk_mpll = {
 	.name		= "mpll",
 	.id		= -1,
 };

 struct clk clk_upll = {
 	.name		= "upll",
 	.id		= -1,
 	.parent		= NULL,
 	.ctrlbit	= 0,
 };

 struct clk clk_f = {
 	.name		= "fclk",
 	.id		= -1,
 	.rate		= 0,
 	.parent		= &clk_mpll,
 	.ctrlbit	= 0,
 };

 struct clk clk_h = {
 	.name		= "hclk",
 	.id		= -1,
 	.rate		= 0,
 	.parent		= NULL,
 	.ctrlbit	= 0,
 };

 struct clk clk_p = {
 	.name		= "pclk",
 	.id		= -1,
 	.rate		= 0,
 	.parent		= NULL,
 	.ctrlbit	= 0,
 };

 struct clk clk_usb_bus = {
 	.name		= "usb-bus",
 	.id		= -1,
 	.rate		= 0,
 	.parent		= &clk_upll,
 };

 /* clocks that could be registered by external code */

 static int s3c24xx_dclk_enable(struct clk *clk, int enable)
 {
 	unsigned long dclkcon = __raw_readl(S3C24XX_DCLKCON);

 	if (enable)
 		dclkcon |= clk->ctrlbit;
 	else
 		dclkcon &= ~clk->ctrlbit;

 	__raw_writel(dclkcon, S3C24XX_DCLKCON);

 	return 0;
 }

 static int s3c24xx_dclk_setparent(struct clk *clk, struct clk *parent)
 {
 	unsigned long dclkcon;
 	unsigned int uclk;

 	if (parent == &clk_upll)
 		uclk = 1;
 	else if (parent == &clk_p)
 		uclk = 0;
 	else
 		return -EINVAL;

 	clk->parent = parent;

 	dclkcon = __raw_readl(S3C24XX_DCLKCON);

 	if (clk->ctrlbit == S3C2410_DCLKCON_DCLK0EN) {
 		if (uclk)
 			dclkcon |= S3C2410_DCLKCON_DCLK0_UCLK;
 		else
 			dclkcon &= ~S3C2410_DCLKCON_DCLK0_UCLK;
 	} else {
 		if (uclk)
 			dclkcon |= S3C2410_DCLKCON_DCLK1_UCLK;
 		else
 			dclkcon &= ~S3C2410_DCLKCON_DCLK1_UCLK;
 	}

 	__raw_writel(dclkcon, S3C24XX_DCLKCON);

 	return 0;
 }


 static int s3c24xx_clkout_setparent(struct clk *clk, struct clk *parent)
 {
 	unsigned long mask;
 	unsigned long source;

 	/* calculate the MISCCR setting for the clock */

 	if (parent == &clk_xtal)
 		source = S3C2410_MISCCR_CLK0_MPLL;
 	else if (parent == &clk_upll)
 		source = S3C2410_MISCCR_CLK0_UPLL;
 	else if (parent == &clk_f)
 		source = S3C2410_MISCCR_CLK0_FCLK;
 	else if (parent == &clk_h)
 		source = S3C2410_MISCCR_CLK0_HCLK;
 	else if (parent == &clk_p)
 		source = S3C2410_MISCCR_CLK0_PCLK;
 	else if (clk == &s3c24xx_clkout0 && parent == &s3c24xx_dclk0)
 		source = S3C2410_MISCCR_CLK0_DCLK0;
 	else if (clk == &s3c24xx_clkout1 && parent == &s3c24xx_dclk1)
 		source = S3C2410_MISCCR_CLK0_DCLK0;
 	else
 		return -EINVAL;

 	clk->parent = parent;

 	if (clk == &s3c24xx_dclk0)
 		mask = S3C2410_MISCCR_CLK0_MASK;
 	else {
 		source <<= 4;
 		mask = S3C2410_MISCCR_CLK1_MASK;
 	}

 	s3c2410_modify_misccr(mask, source);
 	return 0;
 }

 /* external clock definitions */

 struct clk s3c24xx_dclk0 = {
 	.name		= "dclk0",
 	.id		= -1,
 	.ctrlbit	= S3C2410_DCLKCON_DCLK0EN,
 	.enable	        = s3c24xx_dclk_enable,
 	.set_parent	= s3c24xx_dclk_setparent,
 };

 struct clk s3c24xx_dclk1 = {
 	.name		= "dclk1",
 	.id		= -1,
 	.ctrlbit	= S3C2410_DCLKCON_DCLK0EN,
 	.enable		= s3c24xx_dclk_enable,
 	.set_parent	= s3c24xx_dclk_setparent,
 };

 struct clk s3c24xx_clkout0 = {
 	.name		= "clkout0",
 	.id		= -1,
 	.set_parent	= s3c24xx_clkout_setparent,
 };

 struct clk s3c24xx_clkout1 = {
 	.name		= "clkout1",
 	.id		= -1,
 	.set_parent	= s3c24xx_clkout_setparent,
 };

 struct clk s3c24xx_uclk = {
 	.name		= "uclk",
 	.id		= -1,
 };

 /* initialise the clock system */

 int s3c24xx_register_clock(struct clk *clk)
 {
 	clk->owner = THIS_MODULE;

 	if (clk->enable == NULL)
 		clk->enable = clk_null_enable;

 	/* add to the list of available clocks */

 	mutex_lock(&clocks_mutex);
 	list_add(&clk->list, &clocks);
 	mutex_unlock(&clocks_mutex);

 	return 0;
 }

 int s3c24xx_register_clocks(struct clk **clks, int nr_clks)
 {
 	int fails = 0;

 	for (; nr_clks > 0; nr_clks--, clks++) {
 		if (s3c24xx_register_clock(*clks) < 0)
 			fails++;
 	}

 	return fails;
 }

 /* initalise all the clocks */

 int __init s3c24xx_setup_clocks(unsigned long xtal,
 				unsigned long fclk,
 				unsigned long hclk,
 				unsigned long pclk)
 {
 	printk(KERN_INFO "S3C24XX Clocks, (c) 2004 Simtec Electronics\n");

 	/* initialise the main system clocks */

 	clk_xtal.rate = xtal;
 	clk_upll.rate = s3c2410_get_pll(__raw_readl(S3C2410_UPLLCON), xtal);

 	clk_mpll.rate = fclk;
 	clk_h.rate = hclk;
 	clk_p.rate = pclk;
 	clk_f.rate = fclk;

 	/* assume uart clocks are correctly setup */

 	/* register our clocks */

 	if (s3c24xx_register_clock(&clk_xtal) < 0)
 		printk(KERN_ERR "failed to register master xtal\n");

 	if (s3c24xx_register_clock(&clk_mpll) < 0)
 		printk(KERN_ERR "failed to register mpll clock\n");

 	if (s3c24xx_register_clock(&clk_upll) < 0)
 		printk(KERN_ERR "failed to register upll clock\n");

 	if (s3c24xx_register_clock(&clk_f) < 0)
 		printk(KERN_ERR "failed to register cpu fclk\n");

 	if (s3c24xx_register_clock(&clk_h) < 0)
 		printk(KERN_ERR "failed to register cpu hclk\n");

 	if (s3c24xx_register_clock(&clk_p) < 0)
 		printk(KERN_ERR "failed to register cpu pclk\n");

 	return 0;
 }
	/* linux/arch/arm/plat-s3c24xx/clock.c
	*
	* Copyright (c) 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/sysdev.h>
	#include <linux/interrupt.h>
	#include <linux/ioport.h>
	#include <linux/clk.h>
	#include <linux/mutex.h>
	#include <linux/delay.h>

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

	#include <asm/arch/regs-clock.h>
	#include <asm/arch/regs-gpio.h>

	#include <asm/plat-s3c24xx/clock.h>
	#include <asm/plat-s3c24xx/cpu.h>

	/* clock information */

	static LIST_HEAD(clocks);

	DEFINE_MUTEX(clocks_mutex);

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

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

	/* Clock API calls */

	struct clk clk_get(struct device dev, const char *id)
	{
	struct clk *p;
	struct clk *clk = ERR_PTR(-ENOENT);
	int idno;

	if (dev == NULL \|\| dev->bus != &platform_bus_type)
	idno = -1;
	else
	idno = to_platform_device(dev)->id;

	mutex_lock(&clocks_mutex);

	list_for_each_entry(p, &clocks, list) {
	if (p->id == idno &&
	strcmp(id, p->name) == 0 &&
	try_module_get(p->owner)) {
	clk = p;
	break;
	}
	}

	/* check for the case where a device was supplied, but the
	* clock that was being searched for is not device specific */

	if (IS_ERR(clk)) {
	list_for_each_entry(p, &clocks, list) {
	if (p->id == -1 && strcmp(id, p->name) == 0 &&
	try_module_get(p->owner)) {
	clk = p;
	break;
	}
	}
	}

	mutex_unlock(&clocks_mutex);
	return clk;
	}

	void clk_put(struct clk *clk)
	{
	module_put(clk->owner);
	}

	int clk_enable(struct clk *clk)
	{
	if (IS_ERR(clk) \|\| clk == NULL)
	return -EINVAL;

	clk_enable(clk->parent);

	mutex_lock(&clocks_mutex);

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

	mutex_unlock(&clocks_mutex);
	return 0;
	}

	void clk_disable(struct clk *clk)
	{
	if (IS_ERR(clk) \|\| clk == NULL)
	return;

	mutex_lock(&clocks_mutex);

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

	mutex_unlock(&clocks_mutex);
	clk_disable(clk->parent);
	}


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

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

	if (clk->get_rate != NULL)
	return (clk->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(clk) && clk->round_rate)
	return (clk->round_rate)(clk, rate);

	return rate;
	}

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

	if (IS_ERR(clk))
	return -EINVAL;

	mutex_lock(&clocks_mutex);
	ret = (clk->set_rate)(clk, rate);
	mutex_unlock(&clocks_mutex);

	return ret;
	}

	struct clk clk_get_parent(struct clk clk)
	{
	return clk->parent;
	}

	int clk_set_parent(struct clk clk, struct clk parent)
	{
	int ret = 0;

	if (IS_ERR(clk))
	return -EINVAL;

	mutex_lock(&clocks_mutex);

	if (clk->set_parent)
	ret = (clk->set_parent)(clk, parent);

	mutex_unlock(&clocks_mutex);

	return ret;
	}

	EXPORT_SYMBOL(clk_get);
	EXPORT_SYMBOL(clk_put);
	EXPORT_SYMBOL(clk_enable);
	EXPORT_SYMBOL(clk_disable);
	EXPORT_SYMBOL(clk_get_rate);
	EXPORT_SYMBOL(clk_round_rate);
	EXPORT_SYMBOL(clk_set_rate);
	EXPORT_SYMBOL(clk_get_parent);
	EXPORT_SYMBOL(clk_set_parent);

	/* base clocks */

	struct clk clk_xtal = {
	.name = "xtal",
	.id = -1,
	.rate = 0,
	.parent = NULL,
	.ctrlbit = 0,
	};

	struct clk clk_mpll = {
	.name = "mpll",
	.id = -1,
	};

	struct clk clk_upll = {
	.name = "upll",
	.id = -1,
	.parent = NULL,
	.ctrlbit = 0,
	};

	struct clk clk_f = {
	.name = "fclk",
	.id = -1,
	.rate = 0,
	.parent = &clk_mpll,
	.ctrlbit = 0,
	};

	struct clk clk_h = {
	.name = "hclk",
	.id = -1,
	.rate = 0,
	.parent = NULL,
	.ctrlbit = 0,
	};

	struct clk clk_p = {
	.name = "pclk",
	.id = -1,
	.rate = 0,
	.parent = NULL,
	.ctrlbit = 0,
	};

	struct clk clk_usb_bus = {
	.name = "usb-bus",
	.id = -1,
	.rate = 0,
	.parent = &clk_upll,
	};

	/* clocks that could be registered by external code */

	static int s3c24xx_dclk_enable(struct clk *clk, int enable)
	{
	unsigned long dclkcon = __raw_readl(S3C24XX_DCLKCON);

	if (enable)
	dclkcon \|= clk->ctrlbit;
	else
	dclkcon &= ~clk->ctrlbit;

	__raw_writel(dclkcon, S3C24XX_DCLKCON);

	return 0;
	}

	static int s3c24xx_dclk_setparent(struct clk clk, struct clk parent)
	{
	unsigned long dclkcon;
	unsigned int uclk;

	if (parent == &clk_upll)
	uclk = 1;
	else if (parent == &clk_p)
	uclk = 0;
	else
	return -EINVAL;

	clk->parent = parent;

	dclkcon = __raw_readl(S3C24XX_DCLKCON);

	if (clk->ctrlbit == S3C2410_DCLKCON_DCLK0EN) {
	if (uclk)
	dclkcon \|= S3C2410_DCLKCON_DCLK0_UCLK;
	else
	dclkcon &= ~S3C2410_DCLKCON_DCLK0_UCLK;
	} else {
	if (uclk)
	dclkcon \|= S3C2410_DCLKCON_DCLK1_UCLK;
	else
	dclkcon &= ~S3C2410_DCLKCON_DCLK1_UCLK;
	}

	__raw_writel(dclkcon, S3C24XX_DCLKCON);

	return 0;
	}


	static int s3c24xx_clkout_setparent(struct clk clk, struct clk parent)
	{
	unsigned long mask;
	unsigned long source;

	/* calculate the MISCCR setting for the clock */

	if (parent == &clk_xtal)
	source = S3C2410_MISCCR_CLK0_MPLL;
	else if (parent == &clk_upll)
	source = S3C2410_MISCCR_CLK0_UPLL;
	else if (parent == &clk_f)
	source = S3C2410_MISCCR_CLK0_FCLK;
	else if (parent == &clk_h)
	source = S3C2410_MISCCR_CLK0_HCLK;
	else if (parent == &clk_p)
	source = S3C2410_MISCCR_CLK0_PCLK;
	else if (clk == &s3c24xx_clkout0 && parent == &s3c24xx_dclk0)
	source = S3C2410_MISCCR_CLK0_DCLK0;
	else if (clk == &s3c24xx_clkout1 && parent == &s3c24xx_dclk1)
	source = S3C2410_MISCCR_CLK0_DCLK0;
	else
	return -EINVAL;

	clk->parent = parent;

	if (clk == &s3c24xx_dclk0)
	mask = S3C2410_MISCCR_CLK0_MASK;
	else {
	source <<= 4;
	mask = S3C2410_MISCCR_CLK1_MASK;
	}

	s3c2410_modify_misccr(mask, source);
	return 0;
	}

	/* external clock definitions */

	struct clk s3c24xx_dclk0 = {
	.name = "dclk0",
	.id = -1,
	.ctrlbit = S3C2410_DCLKCON_DCLK0EN,
	.enable = s3c24xx_dclk_enable,
	.set_parent = s3c24xx_dclk_setparent,
	};

	struct clk s3c24xx_dclk1 = {
	.name = "dclk1",
	.id = -1,
	.ctrlbit = S3C2410_DCLKCON_DCLK0EN,
	.enable = s3c24xx_dclk_enable,
	.set_parent = s3c24xx_dclk_setparent,
	};

	struct clk s3c24xx_clkout0 = {
	.name = "clkout0",
	.id = -1,
	.set_parent = s3c24xx_clkout_setparent,
	};

	struct clk s3c24xx_clkout1 = {
	.name = "clkout1",
	.id = -1,
	.set_parent = s3c24xx_clkout_setparent,
	};

	struct clk s3c24xx_uclk = {
	.name = "uclk",
	.id = -1,
	};

	/* initialise the clock system */

	int s3c24xx_register_clock(struct clk *clk)
	{
	clk->owner = THIS_MODULE;

	if (clk->enable == NULL)
	clk->enable = clk_null_enable;

	/* add to the list of available clocks */

	mutex_lock(&clocks_mutex);
	list_add(&clk->list, &clocks);
	mutex_unlock(&clocks_mutex);

	return 0;
	}

	int s3c24xx_register_clocks(struct clk **clks, int nr_clks)
	{
	int fails = 0;

	for (; nr_clks > 0; nr_clks--, clks++) {
	if (s3c24xx_register_clock(*clks) < 0)
	fails++;
	}

	return fails;
	}

	/* initalise all the clocks */

	int __init s3c24xx_setup_clocks(unsigned long xtal,
	unsigned long fclk,
	unsigned long hclk,
	unsigned long pclk)
	{
	printk(KERN_INFO "S3C24XX Clocks, (c) 2004 Simtec Electronics\n");

	/* initialise the main system clocks */

	clk_xtal.rate = xtal;
	clk_upll.rate = s3c2410_get_pll(__raw_readl(S3C2410_UPLLCON), xtal);

	clk_mpll.rate = fclk;
	clk_h.rate = hclk;
	clk_p.rate = pclk;
	clk_f.rate = fclk;

	/* assume uart clocks are correctly setup */

	/* register our clocks */

	if (s3c24xx_register_clock(&clk_xtal) < 0)
	printk(KERN_ERR "failed to register master xtal\n");

	if (s3c24xx_register_clock(&clk_mpll) < 0)
	printk(KERN_ERR "failed to register mpll clock\n");

	if (s3c24xx_register_clock(&clk_upll) < 0)
	printk(KERN_ERR "failed to register upll clock\n");

	if (s3c24xx_register_clock(&clk_f) < 0)
	printk(KERN_ERR "failed to register cpu fclk\n");

	if (s3c24xx_register_clock(&clk_h) < 0)
	printk(KERN_ERR "failed to register cpu hclk\n");

	if (s3c24xx_register_clock(&clk_p) < 0)
	printk(KERN_ERR "failed to register cpu pclk\n");

	return 0;
	}