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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 */