2a513ce799
Patch from Ben Dooks Move to using an enable count for the shared clocks and protect the clock system using a mutex instead of just disabling IRQs during the clock update. Since there is little more code in the path for non-shared clocks, the enable and disable calls use the same code for each. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
471 lines
9.7 KiB
C
471 lines
9.7 KiB
C
/* linux/arch/arm/mach-s3c2410/clock.c
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*
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* Copyright (c) 2004-2005 Simtec Electronics
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* Ben Dooks <ben@simtec.co.uk>
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*
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* S3C2410 Clock control support
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*
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* Based on, and code from linux/arch/arm/mach-versatile/clock.c
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**
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** Copyright (C) 2004 ARM Limited.
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** Written by Deep Blue Solutions Limited.
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/errno.h>
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#include <linux/err.h>
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#include <linux/platform_device.h>
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#include <linux/sysdev.h>
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#include <linux/interrupt.h>
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#include <linux/ioport.h>
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#include <linux/clk.h>
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#include <linux/mutex.h>
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#include <asm/hardware.h>
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#include <asm/irq.h>
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#include <asm/io.h>
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#include <asm/arch/regs-clock.h>
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#include "clock.h"
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#include "cpu.h"
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/* clock information */
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static LIST_HEAD(clocks);
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static DEFINE_MUTEX(clocks_mutex);
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/* old functions */
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void inline s3c24xx_clk_enable(unsigned int clocks, unsigned int enable)
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{
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unsigned long clkcon;
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clkcon = __raw_readl(S3C2410_CLKCON);
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if (enable)
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clkcon |= clocks;
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else
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clkcon &= ~clocks;
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/* ensure none of the special function bits set */
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clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);
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__raw_writel(clkcon, S3C2410_CLKCON);
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}
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/* enable and disable calls for use with the clk struct */
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static int clk_null_enable(struct clk *clk, int enable)
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{
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return 0;
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}
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int s3c24xx_clkcon_enable(struct clk *clk, int enable)
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{
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s3c24xx_clk_enable(clk->ctrlbit, enable);
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return 0;
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}
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/* Clock API calls */
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struct clk *clk_get(struct device *dev, const char *id)
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{
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struct clk *p;
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struct clk *clk = ERR_PTR(-ENOENT);
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int idno;
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if (dev == NULL || dev->bus != &platform_bus_type)
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idno = -1;
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else
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idno = to_platform_device(dev)->id;
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mutex_lock(&clocks_mutex);
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list_for_each_entry(p, &clocks, list) {
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if (p->id == idno &&
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strcmp(id, p->name) == 0 &&
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try_module_get(p->owner)) {
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clk = p;
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break;
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}
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}
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/* check for the case where a device was supplied, but the
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* clock that was being searched for is not device specific */
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if (IS_ERR(clk)) {
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list_for_each_entry(p, &clocks, list) {
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if (p->id == -1 && strcmp(id, p->name) == 0 &&
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try_module_get(p->owner)) {
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clk = p;
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break;
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}
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}
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}
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mutex_unlock(&clocks_mutex);
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return clk;
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}
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void clk_put(struct clk *clk)
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{
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module_put(clk->owner);
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}
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int clk_enable(struct clk *clk)
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{
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if (IS_ERR(clk) || clk == NULL)
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return -EINVAL;
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clk_enable(clk->parent);
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mutex_lock(&clocks_mutex);
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if ((clk->usage++) == 0)
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(clk->enable)(clk, 1);
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mutex_unlock(&clocks_mutex);
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return 0;
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}
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void clk_disable(struct clk *clk)
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{
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if (IS_ERR(clk) || clk == NULL)
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return;
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mutex_lock(&clocks_mutex);
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if ((--clk->usage) == 0)
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(clk->enable)(clk, 0);
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mutex_unlock(&clocks_mutex);
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clk_disable(clk->parent);
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}
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unsigned long clk_get_rate(struct clk *clk)
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{
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if (IS_ERR(clk))
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return 0;
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if (clk->rate != 0)
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return clk->rate;
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while (clk->parent != NULL && clk->rate == 0)
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clk = clk->parent;
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return clk->rate;
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}
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long clk_round_rate(struct clk *clk, unsigned long rate)
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{
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return rate;
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}
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int clk_set_rate(struct clk *clk, unsigned long rate)
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{
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return -EINVAL;
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}
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struct clk *clk_get_parent(struct clk *clk)
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{
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return clk->parent;
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}
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EXPORT_SYMBOL(clk_get);
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EXPORT_SYMBOL(clk_put);
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EXPORT_SYMBOL(clk_enable);
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EXPORT_SYMBOL(clk_disable);
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EXPORT_SYMBOL(clk_get_rate);
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EXPORT_SYMBOL(clk_round_rate);
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EXPORT_SYMBOL(clk_set_rate);
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EXPORT_SYMBOL(clk_get_parent);
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/* base clocks */
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static struct clk clk_xtal = {
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.name = "xtal",
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.id = -1,
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.rate = 0,
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.parent = NULL,
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.ctrlbit = 0,
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};
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static struct clk clk_f = {
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.name = "fclk",
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.id = -1,
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.rate = 0,
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.parent = NULL,
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.ctrlbit = 0,
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};
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static struct clk clk_h = {
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.name = "hclk",
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.id = -1,
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.rate = 0,
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.parent = NULL,
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.ctrlbit = 0,
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};
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static struct clk clk_p = {
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.name = "pclk",
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.id = -1,
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.rate = 0,
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.parent = NULL,
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.ctrlbit = 0,
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};
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/* clocks that could be registered by external code */
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struct clk s3c24xx_dclk0 = {
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.name = "dclk0",
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.id = -1,
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};
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struct clk s3c24xx_dclk1 = {
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.name = "dclk1",
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.id = -1,
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};
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struct clk s3c24xx_clkout0 = {
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.name = "clkout0",
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.id = -1,
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};
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struct clk s3c24xx_clkout1 = {
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.name = "clkout1",
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.id = -1,
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};
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struct clk s3c24xx_uclk = {
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.name = "uclk",
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.id = -1,
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};
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/* clock definitions */
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static struct clk init_clocks[] = {
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{
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.name = "nand",
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.id = -1,
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.parent = &clk_h,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_NAND,
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}, {
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.name = "lcd",
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.id = -1,
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.parent = &clk_h,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_LCDC,
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}, {
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.name = "usb-host",
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.id = -1,
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.parent = &clk_h,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_USBH,
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}, {
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.name = "usb-device",
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.id = -1,
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.parent = &clk_h,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_USBD,
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}, {
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.name = "timers",
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.id = -1,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_PWMT,
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}, {
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.name = "sdi",
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.id = -1,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_SDI,
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}, {
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.name = "uart",
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.id = 0,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_UART0,
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}, {
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.name = "uart",
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.id = 1,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_UART1,
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}, {
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.name = "uart",
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.id = 2,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_UART2,
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}, {
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.name = "gpio",
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.id = -1,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_GPIO,
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}, {
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.name = "rtc",
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.id = -1,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_RTC,
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}, {
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.name = "adc",
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.id = -1,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_ADC,
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}, {
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.name = "i2c",
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.id = -1,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_IIC,
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}, {
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.name = "iis",
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.id = -1,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_IIS,
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}, {
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.name = "spi",
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.id = -1,
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.parent = &clk_p,
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.enable = s3c24xx_clkcon_enable,
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.ctrlbit = S3C2410_CLKCON_SPI,
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}, {
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.name = "watchdog",
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.id = -1,
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.parent = &clk_p,
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.ctrlbit = 0,
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}
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};
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/* initialise the clock system */
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int s3c24xx_register_clock(struct clk *clk)
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{
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clk->owner = THIS_MODULE;
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if (clk->enable == NULL)
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clk->enable = clk_null_enable;
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/* if this is a standard clock, set the usage state */
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if (clk->ctrlbit) {
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unsigned long clkcon = __raw_readl(S3C2410_CLKCON);
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clk->usage = (clkcon & clk->ctrlbit) ? 1 : 0;
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}
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/* add to the list of available clocks */
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mutex_lock(&clocks_mutex);
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list_add(&clk->list, &clocks);
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mutex_unlock(&clocks_mutex);
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return 0;
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}
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/* initalise all the clocks */
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int __init s3c24xx_setup_clocks(unsigned long xtal,
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unsigned long fclk,
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unsigned long hclk,
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unsigned long pclk)
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{
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unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
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struct clk *clkp = init_clocks;
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int ptr;
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int ret;
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printk(KERN_INFO "S3C2410 Clocks, (c) 2004 Simtec Electronics\n");
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/* initialise the main system clocks */
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clk_xtal.rate = xtal;
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clk_h.rate = hclk;
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clk_p.rate = pclk;
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clk_f.rate = fclk;
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/* We must be careful disabling the clocks we are not intending to
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* be using at boot time, as subsytems such as the LCD which do
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* their own DMA requests to the bus can cause the system to lockup
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* if they where in the middle of requesting bus access.
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*
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* Disabling the LCD clock if the LCD is active is very dangerous,
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* and therefore the bootloader should be careful to not enable
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* the LCD clock if it is not needed.
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*/
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mutex_lock(&clocks_mutex);
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s3c24xx_clk_enable(S3C2410_CLKCON_NAND, 0);
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s3c24xx_clk_enable(S3C2410_CLKCON_USBH, 0);
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s3c24xx_clk_enable(S3C2410_CLKCON_USBD, 0);
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s3c24xx_clk_enable(S3C2410_CLKCON_ADC, 0);
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s3c24xx_clk_enable(S3C2410_CLKCON_IIC, 0);
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s3c24xx_clk_enable(S3C2410_CLKCON_SPI, 0);
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mutex_unlock(&clocks_mutex);
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/* assume uart clocks are correctly setup */
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/* register our clocks */
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if (s3c24xx_register_clock(&clk_xtal) < 0)
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printk(KERN_ERR "failed to register master xtal\n");
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if (s3c24xx_register_clock(&clk_f) < 0)
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printk(KERN_ERR "failed to register cpu fclk\n");
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if (s3c24xx_register_clock(&clk_h) < 0)
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printk(KERN_ERR "failed to register cpu hclk\n");
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if (s3c24xx_register_clock(&clk_p) < 0)
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printk(KERN_ERR "failed to register cpu pclk\n");
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/* register clocks from clock array */
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for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
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ret = s3c24xx_register_clock(clkp);
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if (ret < 0) {
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printk(KERN_ERR "Failed to register clock %s (%d)\n",
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clkp->name, ret);
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}
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}
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/* show the clock-slow value */
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printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
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print_mhz(xtal / ( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
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(clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
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(clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
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(clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");
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return 0;
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}
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