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/*
 *  linux/include/linux/cpufreq.h
 *
 *  Copyright (C) 2001 Russell King
 *            (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
 *            
 *
 * $Id: cpufreq.h,v 1.1 2004-01-28 15:25:05 giacomo Exp $
 *
 * 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.
 */

#ifndef _LINUX_CPUFREQ_H
#define _LINUX_CPUFREQ_H

#include <linux/config.h>
#include <linux/notifier.h>
#include <linux/threads.h>
#include <linux/device.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/completion.h>

#define CPUFREQ_NAME_LEN 16


/*********************************************************************
 *                     CPUFREQ NOTIFIER INTERFACE                    *
 *********************************************************************/


int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list);
int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list);

#define CPUFREQ_TRANSITION_NOTIFIER     (0)
#define CPUFREQ_POLICY_NOTIFIER         (1)


/* if (cpufreq_driver->target) exists, the ->governor decides what frequency
 * within the limits is used. If (cpufreq_driver->setpolicy> exists, these
 * two generic policies are available:
 */


#define CPUFREQ_POLICY_POWERSAVE        (1)
#define CPUFREQ_POLICY_PERFORMANCE      (2)

/* Frequency values here are CPU kHz so that hardware which doesn't run
 * with some frequencies can complain without having to guess what per
 * cent / per mille means.
 * Maximum transition latency is in microseconds - if it's unknown,
 * CPUFREQ_ETERNAL shall be used.
 */


struct cpufreq_governor;

#define CPUFREQ_ETERNAL                 (-1)
struct cpufreq_cpuinfo {
        unsigned int            max_freq;
        unsigned int            min_freq;
        unsigned int            transition_latency; /* in 10^(-9) s */
};

struct cpufreq_real_policy {
        unsigned int            min;    /* in kHz */
        unsigned int            max;    /* in kHz */
        unsigned int            policy; /* see above */
        struct cpufreq_governor *governor; /* see below */
};

struct cpufreq_policy {
        unsigned int            cpu;    /* cpu nr */
        struct cpufreq_cpuinfo  cpuinfo;/* see above */

        unsigned int            min;    /* in kHz */
        unsigned int            max;    /* in kHz */
        unsigned int            cur;    /* in kHz, only needed if cpufreq
                                         * governors are used */

        unsigned int            policy; /* see above */
        struct cpufreq_governor *governor; /* see below */

        struct semaphore        lock;   /* CPU ->setpolicy or ->target may
                                           only be called once a time */


        struct cpufreq_real_policy      user_policy;

        struct kobject          kobj;
        struct completion       kobj_unregister;
};

#define CPUFREQ_ADJUST          (0)
#define CPUFREQ_INCOMPATIBLE    (1)
#define CPUFREQ_NOTIFY          (2)


/******************** cpufreq transition notifiers *******************/

#define CPUFREQ_PRECHANGE       (0)
#define CPUFREQ_POSTCHANGE      (1)

struct cpufreq_freqs {
        unsigned int cpu;       /* cpu nr */
        unsigned int old;
        unsigned int new;
};


/**
 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch safe)
 * @old:   old value
 * @div:   divisor
 * @mult:  multiplier
 *
 * Needed for loops_per_jiffy and similar calculations.  We do it
 * this way to avoid math overflow on 32-bit machines.  This will
 * become architecture dependent once high-resolution-timer is
 * merged (or any other thing that introduces sc_math.h).
 *
 *    new = old * mult / div
 */

static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mult)
{
        unsigned long val, carry;

        mult /= 100;
        div  /= 100;
        val   = (old / div) * mult;
        carry = old % div;
        carry = carry * mult / div;

        return carry + val;
};

/*********************************************************************
 *                          CPUFREQ GOVERNORS                        *
 *********************************************************************/


#define CPUFREQ_GOV_START  1
#define CPUFREQ_GOV_STOP   2
#define CPUFREQ_GOV_LIMITS 3

struct cpufreq_governor {
        char    name[CPUFREQ_NAME_LEN];
        int     (*governor)     (struct cpufreq_policy *policy,
                                 unsigned int event);
        struct list_head        governor_list;
        struct module           *owner;
};

/* pass a target to the cpufreq driver
 */

extern int cpufreq_driver_target(struct cpufreq_policy *policy,
                                 unsigned int target_freq,
                                 unsigned int relation);
extern int __cpufreq_driver_target(struct cpufreq_policy *policy,
                                   unsigned int target_freq,
                                   unsigned int relation);


/* pass an event to the cpufreq governor */
int cpufreq_governor(unsigned int cpu, unsigned int event);

int cpufreq_register_governor(struct cpufreq_governor *governor);
void cpufreq_unregister_governor(struct cpufreq_governor *governor);


/*********************************************************************
 *                      CPUFREQ DRIVER INTERFACE                     *
 *********************************************************************/


#define CPUFREQ_RELATION_L 0  /* lowest frequency at or above target */
#define CPUFREQ_RELATION_H 1  /* highest frequency below or at target */

struct freq_attr;

struct cpufreq_driver {
        struct module           *owner;
        char                    name[CPUFREQ_NAME_LEN];

        /* needed by all drivers */
        int     (*init)         (struct cpufreq_policy *policy);
        int     (*verify)       (struct cpufreq_policy *policy);

        /* define one out of two */
        int     (*setpolicy)    (struct cpufreq_policy *policy);
        int     (*target)       (struct cpufreq_policy *policy,
                                 unsigned int target_freq,
                                 unsigned int relation);

        /* optional */
        int     (*exit)         (struct cpufreq_policy *policy);
        int     (*resume)       (struct cpufreq_policy *policy);
        struct freq_attr        **attr;
};

int cpufreq_register_driver(struct cpufreq_driver *driver_data);
int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);


void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state);


static inline void cpufreq_verify_within_limits(struct cpufreq_policy *policy, unsigned int min, unsigned int max)
{
        if (policy->min < min)
                policy->min = min;
        if (policy->max < min)
                policy->max = min;
        if (policy->min > max)
                policy->min = max;
        if (policy->max > max)
                policy->max = max;
        if (policy->min > policy->max)
                policy->min = policy->max;
        return;
}

struct freq_attr {
        struct attribute attr;
        ssize_t (*show)(struct cpufreq_policy *, char *);
        ssize_t (*store)(struct cpufreq_policy *, const char *, size_t count);
};


/*********************************************************************
 *                        CPUFREQ 2.6. INTERFACE                     *
 *********************************************************************/

int cpufreq_set_policy(struct cpufreq_policy *policy);
int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
int cpufreq_update_policy(unsigned int cpu);

/* the proc_intf.c needs this */
int cpufreq_parse_governor (char *str_governor, unsigned int *policy, struct cpufreq_governor **governor);

#if defined(CONFIG_CPU_FREQ_GOV_USERSPACE) || defined(CONFIG_CPU_FREQ_GOV_USERSPACE_MODULE)
/*********************************************************************
 *                      CPUFREQ USERSPACE GOVERNOR                   *
 *********************************************************************/

int cpufreq_gov_userspace_init(void);

int cpufreq_setmax(unsigned int cpu);
int cpufreq_set(unsigned int kHz, unsigned int cpu);
unsigned int cpufreq_get(unsigned int cpu);

#ifdef CONFIG_CPU_FREQ_24_API

/* /proc/sys/cpu */
enum {
        CPU_NR   = 1,           /* compatibilty reasons */
        CPU_NR_0 = 1,
        CPU_NR_1 = 2,
        CPU_NR_2 = 3,
        CPU_NR_3 = 4,
        CPU_NR_4 = 5,
        CPU_NR_5 = 6,
        CPU_NR_6 = 7,
        CPU_NR_7 = 8,
        CPU_NR_8 = 9,
        CPU_NR_9 = 10,
        CPU_NR_10 = 11,
        CPU_NR_11 = 12,
        CPU_NR_12 = 13,
        CPU_NR_13 = 14,
        CPU_NR_14 = 15,
        CPU_NR_15 = 16,
        CPU_NR_16 = 17,
        CPU_NR_17 = 18,
        CPU_NR_18 = 19,
        CPU_NR_19 = 20,
        CPU_NR_20 = 21,
        CPU_NR_21 = 22,
        CPU_NR_22 = 23,
        CPU_NR_23 = 24,
        CPU_NR_24 = 25,
        CPU_NR_25 = 26,
        CPU_NR_26 = 27,
        CPU_NR_27 = 28,
        CPU_NR_28 = 29,
        CPU_NR_29 = 30,
        CPU_NR_30 = 31,
        CPU_NR_31 = 32,
};

/* /proc/sys/cpu/{0,1,...,(NR_CPUS-1)} */
enum {
        CPU_NR_FREQ_MAX = 1,
        CPU_NR_FREQ_MIN = 2,
        CPU_NR_FREQ = 3,
};

#endif /* CONFIG_CPU_FREQ_24_API */

#endif /* CONFIG_CPU_FREQ_GOV_USERSPACE */


/*********************************************************************
 *                       CPUFREQ DEFAULT GOVERNOR                    *
 *********************************************************************/



#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
extern struct cpufreq_governor cpufreq_gov_performance;
#define CPUFREQ_DEFAULT_GOVERNOR        &cpufreq_gov_performance
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
extern struct cpufreq_governor cpufreq_gov_userspace;
#define CPUFREQ_DEFAULT_GOVERNOR        &cpufreq_gov_userspace
#endif

/*********************************************************************
 *                     FREQUENCY TABLE HELPERS                       *
 *********************************************************************/


#define CPUFREQ_ENTRY_INVALID ~0
#define CPUFREQ_TABLE_END     ~1

struct cpufreq_frequency_table {
        unsigned int    index;     /* any */
        unsigned int    frequency; /* kHz - doesn't need to be in ascending
                                    * order */

};

#if defined(CONFIG_CPU_FREQ_TABLE) || defined(CONFIG_CPU_FREQ_TABLE_MODULE)
int cpufreq_frequency_table_cpuinfo(struct cpufreq_policy *policy,
                                    struct cpufreq_frequency_table *table);

int cpufreq_frequency_table_verify(struct cpufreq_policy *policy,
                                   struct cpufreq_frequency_table *table);

int cpufreq_frequency_table_target(struct cpufreq_policy *policy,
                                   struct cpufreq_frequency_table *table,
                                   unsigned int target_freq,
                                   unsigned int relation,
                                   unsigned int *index);

/* the following are really really optional */
extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;

void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table,
                                      unsigned int cpu);

void cpufreq_frequency_table_put_attr(unsigned int cpu);


#endif /* CONFIG_CPU_FREQ_TABLE */
#endif /* _LINUX_CPUFREQ_H */