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/*
* Copyright (c) 2009 Simtec Electronics
* http://armlinux.simtec.co.uk/
* Ben Dooks <ben@simtec.co.uk>
*
* S3C24XX CPU Frequency scaling - utils for S3C2410/S3C2440/S3C2442
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/cpufreq.h>
#include <linux/io.h>
#include <mach/map.h>
#include <mach/regs-mem.h>
#include <mach/regs-clock.h>
#include <plat/cpu-freq-core.h>
/**
* s3c2410_cpufreq_setrefresh - set SDRAM refresh value
* @cfg: The frequency configuration
*
* Set the SDRAM refresh value appropriately for the configured
* frequency.
*/
void s3c2410_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
{
struct s3c_cpufreq_board *board = cfg->board;
unsigned long refresh;
unsigned long refval;
/* Reduce both the refresh time (in ns) and the frequency (in MHz)
* down to ensure that we do not overflow 32 bit numbers.
*
* This should work for HCLK up to 133MHz and refresh period up
* to 30usec.
*/
refresh = (cfg->freq.hclk / 100) * (board->refresh / 10);
refresh = DIV_ROUND_UP(refresh, (1000 * 1000)); /* apply scale */
refresh = (1 << 11) + 1 - refresh;
s3c_freq_dbg("%s: refresh value %lu\n", __func__, refresh);
refval = __raw_readl(S3C2410_REFRESH);
refval &= ~((1 << 12) - 1);
refval |= refresh;
__raw_writel(refval, S3C2410_REFRESH);
}
/**
* s3c2410_set_fvco - set the PLL value
* @cfg: The frequency configuration
*/
void s3c2410_set_fvco(struct s3c_cpufreq_config *cfg)
{
__raw_writel(cfg->pll.index, S3C2410_MPLLCON);
}
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