/* * 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-clock.h> #include <plat/cpu-freq-core.h> #include "regs-mem.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); }