linux-imx

/*

 * Copyright (c) 2006-2008 Simtec Electronics

 *  http://armlinux.simtec.co.uk/

 *  Ben Dooks <ben@simtec.co.uk>

 *

 * S3C24XX CPU Frequency scaling

 *

 * 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.

*/

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/init.h>

#include <linux/module.h>

#include <linux/interrupt.h>

#include <linux/ioport.h>

#include <linux/cpufreq.h>

#include <linux/cpu.h>

#include <linux/clk.h>

#include <linux/err.h>

#include <linux/io.h>

#include <linux/device.h>

#include <linux/sysfs.h>

#include <linux/slab.h>

​

#include <asm/mach/arch.h>

#include <asm/mach/map.h>

​

#include <plat/cpu.h>

#include <plat/cpu-freq-core.h>

​

#include <mach/regs-clock.h>

​

/* note, cpufreq support deals in kHz, no Hz */

​

static struct cpufreq_driver s3c24xx_driver;

static struct s3c_cpufreq_config cpu_cur;

static struct s3c_iotimings s3c24xx_iotiming;

static struct cpufreq_frequency_table *pll_reg;

static unsigned int last_target = ~0;

static unsigned int ftab_size;

static struct cpufreq_frequency_table *ftab;

​

static struct clk *_clk_mpll;

static struct clk *_clk_xtal;

static struct clk *clk_fclk;

static struct clk *clk_hclk;

static struct clk *clk_pclk;

static struct clk *clk_arm;

​

#ifdef CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS

struct s3c_cpufreq_config *s3c_cpufreq_getconfig(void)

{

    return &cpu_cur;

}

​

struct s3c_iotimings *s3c_cpufreq_getiotimings(void)

{

    return &s3c24xx_iotiming;

}

#endif /* CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS */

​

static void s3c_cpufreq_getcur(struct s3c_cpufreq_config *cfg)

{

    unsigned long fclk, pclk, hclk, armclk;

​

    cfg->freq.fclk = fclk = clk_get_rate(clk_fclk);

    cfg->freq.hclk = hclk = clk_get_rate(clk_hclk);

    cfg->freq.pclk = pclk = clk_get_rate(clk_pclk);

    cfg->freq.armclk = armclk = clk_get_rate(clk_arm);

​

    cfg->pll.driver_data = __raw_readl(S3C2410_MPLLCON);

    cfg->pll.frequency = fclk;

​

    cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);

​

    cfg->divs.h_divisor = fclk / hclk;

    cfg->divs.p_divisor = fclk / pclk;

}

​

static inline void s3c_cpufreq_calc(struct s3c_cpufreq_config *cfg)

{

    unsigned long pll = cfg->pll.frequency;

​

    cfg->freq.fclk = pll;

    cfg->freq.hclk = pll / cfg->divs.h_divisor;

    cfg->freq.pclk = pll / cfg->divs.p_divisor;

​

    /* convert hclk into 10ths of nanoseconds for io calcs */

    cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);