linux-imx

/*

 *  This file was based upon code in Powertweak Linux (http://powertweak.sf.net)

 *  (C) 2000-2003  Dave Jones, Arjan van de Ven, Janne Pänkälä,

 *                 Dominik Brodowski.

 *

 *  Licensed under the terms of the GNU GPL License version 2.

 *

 *  BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/cpufreq.h>

#include <linux/ioport.h>

#include <linux/timex.h>

#include <linux/io.h>

​

#include <asm/cpu_device_id.h>

#include <asm/msr.h>

​

#define POWERNOW_IOPORT 0xfff0          /* it doesn't matter where, as long

                       as it is unused */

​

static unsigned int                     busfreq;   /* FSB, in 10 kHz */

static unsigned int                     max_multiplier;

​

static unsigned int         param_busfreq = 0;

static unsigned int         param_max_multiplier = 0;

​

module_param_named(max_multiplier, param_max_multiplier, uint, S_IRUGO);

MODULE_PARM_DESC(max_multiplier, "Maximum multiplier (allowed values: 20 30 35 40 45 50 55 60)");

​

module_param_named(bus_frequency, param_busfreq, uint, S_IRUGO);

MODULE_PARM_DESC(bus_frequency, "Bus frequency in kHz");

​

/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */

static struct cpufreq_frequency_table clock_ratio[] = {

    {0, 60,  /* 110 -> 6.0x */ 0},

    {0, 55,  /* 011 -> 5.5x */ 0},

    {0, 50,  /* 001 -> 5.0x */ 0},

    {0, 45,  /* 000 -> 4.5x */ 0},

    {0, 40,  /* 010 -> 4.0x */ 0},

    {0, 35,  /* 111 -> 3.5x */ 0},

    {0, 30,  /* 101 -> 3.0x */ 0},

    {0, 20,  /* 100 -> 2.0x */ 0},

    {0, 0, CPUFREQ_TABLE_END}

};

​

static const u8 index_to_register[8] = { 6, 3, 1, 0, 2, 7, 5, 4 };

static const u8 register_to_index[8] = { 3, 2, 4, 1, 7, 6, 0, 5 };

​

static const struct {

    unsigned freq;

    unsigned mult;

} usual_frequency_table[] = {

    { 350000, 35 }, // 100   * 3.5

    { 400000, 40 }, // 100   * 4

    { 450000, 45 }, // 100   * 4.5

    { 475000, 50 }, //  95   * 5

    { 500000, 50 }, // 100   * 5

    { 506250, 45 }, // 112.5 * 4.5

    { 533500, 55 }, //  97   * 5.5

    { 550000, 55 }, // 100   * 5.5

    { 562500, 50 }, // 112.5 * 5

    { 570000, 60 }, //  95   * 6

    { 600000, 60 }, // 100   * 6

    { 618750, 55 }, // 112.5 * 5.5

    { 660000, 55 }, // 120   * 5.5

    { 675000, 60 }, // 112.5 * 6

    { 720000, 60 }, // 120   * 6

};

​

#define FREQ_RANGE      3000

​

/**

 * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier

 *

 * Returns the current setting of the frequency multiplier. Core clock

 * speed is frequency of the Front-Side Bus multiplied with this value.

 */

static int powernow_k6_get_cpu_multiplier(void)

{

    unsigned long invalue = 0;

    u32 msrval;

​

    local_irq_disable();

​

    msrval = POWERNOW_IOPORT + 0x1;

    wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */