forked from Minki/linux
65 lines
1.7 KiB
C
65 lines
1.7 KiB
C
|
/* linux/arch/arm/plat-s3c24xx/s3c2410-cpufreq-utils.c
|
||
|
|
*
|
||
|
|
* 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);
|
||
|
|
}
|