root/include/linux/cpufreq.h

INCLUDED FROM

DEFINITIONS

1. cpufreq_cpu_get
2. cpufreq_cpu_put
3. policy_is_shared
4. cpufreq_get
5. cpufreq_quick_get
6. cpufreq_quick_get_max
7. disable_cpufreq
8. cpufreq_verify_within_limits
9. cpufreq_verify_within_cpu_limits
10. cpufreq_suspend
11. cpufreq_resume
12. cpufreq_register_notifier
13. cpufreq_unregister_notifier
14. cpufreq_scale
15. dev_pm_opp_init_cpufreq_table
16. dev_pm_opp_free_cpufreq_table
17. cpufreq_next_valid
18. cpufreq_boost_trigger_state
19. cpufreq_boost_supported
20. cpufreq_boost_enabled

/*
 * linux/include/linux/cpufreq.h
 *
 * Copyright (C) 2001 Russell King
 *           (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
 *
 * 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/clk.h>
#include <linux/cpumask.h>
#include <linux/completion.h>
#include <linux/kobject.h>
#include <linux/notifier.h>
#include <linux/spinlock.h>
#include <linux/sysfs.h>

/*********************************************************************
 *                        CPUFREQ INTERFACE                          *
 *********************************************************************/
/*
 * Frequency values here are CPU kHz
 *
 * Maximum transition latency is in nanoseconds - if it's unknown,
 * CPUFREQ_ETERNAL shall be used.
 */

#define CPUFREQ_ETERNAL                 (-1)
#define CPUFREQ_NAME_LEN                16
/* Print length for names. Extra 1 space for accomodating '\n' in prints */
#define CPUFREQ_NAME_PLEN               (CPUFREQ_NAME_LEN + 1)

struct cpufreq_governor;

struct cpufreq_freqs {
        unsigned int cpu;       /* cpu nr */
        unsigned int old;
        unsigned int new;
        u8 flags;               /* flags of cpufreq_driver, see below. */
};

struct cpufreq_cpuinfo {
        unsigned int            max_freq;
        unsigned int            min_freq;

        /* in 10^(-9) s = nanoseconds */
        unsigned int            transition_latency;
};

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 {
        /* CPUs sharing clock, require sw coordination */
        cpumask_var_t           cpus;   /* Online CPUs only */
        cpumask_var_t           related_cpus; /* Online + Offline CPUs */

        unsigned int            shared_type; /* ACPI: ANY or ALL affected CPUs
                                                should set cpufreq */
        unsigned int            cpu;    /* cpu nr of CPU managing this policy */
        unsigned int            last_cpu; /* cpu nr of previous CPU that managed
                                           * this policy */
        struct clk              *clk;
        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            restore_freq; /* = policy->cur before transition */
        unsigned int            suspend_freq; /* freq to set during suspend */

        unsigned int            policy; /* see above */
        struct cpufreq_governor *governor; /* see below */
        void                    *governor_data;
        bool                    governor_enabled; /* governor start/stop flag */

        struct work_struct      update; /* if update_policy() needs to be
                                         * called, but you're in IRQ context */

        struct cpufreq_real_policy      user_policy;
        struct cpufreq_frequency_table  *freq_table;

        struct list_head        policy_list;
        struct kobject          kobj;
        struct completion       kobj_unregister;

        /*
         * The rules for this semaphore:
         * - Any routine that wants to read from the policy structure will
         *   do a down_read on this semaphore.
         * - Any routine that will write to the policy structure and/or may take away
         *   the policy altogether (eg. CPU hotplug), will hold this lock in write
         *   mode before doing so.
         *
         * Additional rules:
         * - Lock should not be held across
         *     __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT);
         */
        struct rw_semaphore     rwsem;

        /* Synchronization for frequency transitions */
        bool                    transition_ongoing; /* Tracks transition status */
        spinlock_t              transition_lock;
        wait_queue_head_t       transition_wait;
        struct task_struct      *transition_task; /* Task which is doing the transition */

        /* For cpufreq driver's internal use */
        void                    *driver_data;
};

/* Only for ACPI */
#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
#define CPUFREQ_SHARED_TYPE_HW   (1) /* HW does needed coordination */
#define CPUFREQ_SHARED_TYPE_ALL  (2) /* All dependent CPUs should set freq */
#define CPUFREQ_SHARED_TYPE_ANY  (3) /* Freq can be set from any dependent CPU*/

#ifdef CONFIG_CPU_FREQ
struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu);
void cpufreq_cpu_put(struct cpufreq_policy *policy);
#else
static inline struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu)
{
        return NULL;
}
static inline void cpufreq_cpu_put(struct cpufreq_policy *policy) { }
#endif

static inline bool policy_is_shared(struct cpufreq_policy *policy)
{
        return cpumask_weight(policy->cpus) > 1;
}

/* /sys/devices/system/cpu/cpufreq: entry point for global variables */
extern struct kobject *cpufreq_global_kobject;
int cpufreq_get_global_kobject(void);
void cpufreq_put_global_kobject(void);
int cpufreq_sysfs_create_file(const struct attribute *attr);
void cpufreq_sysfs_remove_file(const struct attribute *attr);

#ifdef CONFIG_CPU_FREQ
unsigned int cpufreq_get(unsigned int cpu);
unsigned int cpufreq_quick_get(unsigned int cpu);
unsigned int cpufreq_quick_get_max(unsigned int cpu);
void disable_cpufreq(void);

u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu);
int cpufreq_update_policy(unsigned int cpu);
bool have_governor_per_policy(void);
struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy);
#else
static inline unsigned int cpufreq_get(unsigned int cpu)
{
        return 0;
}
static inline unsigned int cpufreq_quick_get(unsigned int cpu)
{
        return 0;
}
static inline unsigned int cpufreq_quick_get_max(unsigned int cpu)
{
        return 0;
}
static inline void disable_cpufreq(void) { }
#endif

/*********************************************************************
 *                      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 */
#define CPUFREQ_RELATION_C 2  /* closest frequency to target */

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

#define cpufreq_freq_attr_ro(_name)             \
static struct freq_attr _name =                 \
__ATTR(_name, 0444, show_##_name, NULL)

#define cpufreq_freq_attr_ro_perm(_name, _perm) \
static struct freq_attr _name =                 \
__ATTR(_name, _perm, show_##_name, NULL)

#define cpufreq_freq_attr_rw(_name)             \
static struct freq_attr _name =                 \
__ATTR(_name, 0644, show_##_name, store_##_name)

struct global_attr {
        struct attribute attr;
        ssize_t (*show)(struct kobject *kobj,
                        struct attribute *attr, char *buf);
        ssize_t (*store)(struct kobject *a, struct attribute *b,
                         const char *c, size_t count);
};

#define define_one_global_ro(_name)             \
static struct global_attr _name =               \
__ATTR(_name, 0444, show_##_name, NULL)

#define define_one_global_rw(_name)             \
static struct global_attr _name =               \
__ATTR(_name, 0644, show_##_name, store_##_name)


struct cpufreq_driver {
        char                    name[CPUFREQ_NAME_LEN];
        u8                      flags;
        void                    *driver_data;

        /* 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);

        /*
         * On failure, should always restore frequency to policy->restore_freq
         * (i.e. old freq).
         */
        int     (*target)       (struct cpufreq_policy *policy, /* Deprecated */
                                 unsigned int target_freq,
                                 unsigned int relation);
        int     (*target_index) (struct cpufreq_policy *policy,
                                 unsigned int index);
        /*
         * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION
         * unset.
         *
         * get_intermediate should return a stable intermediate frequency
         * platform wants to switch to and target_intermediate() should set CPU
         * to to that frequency, before jumping to the frequency corresponding
         * to 'index'. Core will take care of sending notifications and driver
         * doesn't have to handle them in target_intermediate() or
         * target_index().
         *
         * Drivers can return '0' from get_intermediate() in case they don't
         * wish to switch to intermediate frequency for some target frequency.
         * In that case core will directly call ->target_index().
         */
        unsigned int (*get_intermediate)(struct cpufreq_policy *policy,
                                         unsigned int index);
        int     (*target_intermediate)(struct cpufreq_policy *policy,
                                       unsigned int index);

        /* should be defined, if possible */
        unsigned int    (*get)  (unsigned int cpu);

        /* optional */
        int     (*bios_limit)   (int cpu, unsigned int *limit);

        int     (*exit)         (struct cpufreq_policy *policy);
        void    (*stop_cpu)     (struct cpufreq_policy *policy);
        int     (*suspend)      (struct cpufreq_policy *policy);
        int     (*resume)       (struct cpufreq_policy *policy);
        struct freq_attr        **attr;

        /* platform specific boost support code */
        bool                    boost_supported;
        bool                    boost_enabled;
        int     (*set_boost)    (int state);
};

/* flags */
#define CPUFREQ_STICKY          (1 << 0)        /* driver isn't removed even if
                                                   all ->init() calls failed */
#define CPUFREQ_CONST_LOOPS     (1 << 1)        /* loops_per_jiffy or other
                                                   kernel "constants" aren't
                                                   affected by frequency
                                                   transitions */
#define CPUFREQ_PM_NO_WARN      (1 << 2)        /* don't warn on suspend/resume
                                                   speed mismatches */

/*
 * This should be set by platforms having multiple clock-domains, i.e.
 * supporting multiple policies. With this sysfs directories of governor would
 * be created in cpu/cpu<num>/cpufreq/ directory and so they can use the same
 * governor with different tunables for different clusters.
 */
#define CPUFREQ_HAVE_GOVERNOR_PER_POLICY (1 << 3)

/*
 * Driver will do POSTCHANGE notifications from outside of their ->target()
 * routine and so must set cpufreq_driver->flags with this flag, so that core
 * can handle them specially.
 */
#define CPUFREQ_ASYNC_NOTIFICATION  (1 << 4)

/*
 * Set by drivers which want cpufreq core to check if CPU is running at a
 * frequency present in freq-table exposed by the driver. For these drivers if
 * CPU is found running at an out of table freq, we will try to set it to a freq
 * from the table. And if that fails, we will stop further boot process by
 * issuing a BUG_ON().
 */
#define CPUFREQ_NEED_INITIAL_FREQ_CHECK (1 << 5)

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

const char *cpufreq_get_current_driver(void);
void *cpufreq_get_driver_data(void);

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;
}

static inline void
cpufreq_verify_within_cpu_limits(struct cpufreq_policy *policy)
{
        cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
                        policy->cpuinfo.max_freq);
}

#ifdef CONFIG_CPU_FREQ
void cpufreq_suspend(void);
void cpufreq_resume(void);
int cpufreq_generic_suspend(struct cpufreq_policy *policy);
#else
static inline void cpufreq_suspend(void) {}
static inline void cpufreq_resume(void) {}
#endif

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

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

/* Transition notifiers */
#define CPUFREQ_PRECHANGE               (0)
#define CPUFREQ_POSTCHANGE              (1)

/* Policy Notifiers  */
#define CPUFREQ_ADJUST                  (0)
#define CPUFREQ_INCOMPATIBLE            (1)
#define CPUFREQ_NOTIFY                  (2)
#define CPUFREQ_START                   (3)
#define CPUFREQ_UPDATE_POLICY_CPU       (4)
#define CPUFREQ_CREATE_POLICY           (5)
#define CPUFREQ_REMOVE_POLICY           (6)

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

void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
                struct cpufreq_freqs *freqs);
void cpufreq_freq_transition_end(struct cpufreq_policy *policy,
                struct cpufreq_freqs *freqs, int transition_failed);

#else /* CONFIG_CPU_FREQ */
static inline int cpufreq_register_notifier(struct notifier_block *nb,
                                                unsigned int list)
{
        return 0;
}
static inline int cpufreq_unregister_notifier(struct notifier_block *nb,
                                                unsigned int list)
{
        return 0;
}
#endif /* !CONFIG_CPU_FREQ */

/**
 * cpufreq_scale - "old * mult / div" calculation for large values (32-bit-arch
 * safe)
 * @old:   old value
 * @div:   divisor
 * @mult:  multiplier
 *
 *
 * new = old * mult / div
 */
static inline unsigned long cpufreq_scale(unsigned long old, u_int div,
                u_int mult)
{
#if BITS_PER_LONG == 32
        u64 result = ((u64) old) * ((u64) mult);
        do_div(result, div);
        return (unsigned long) result;

#elif BITS_PER_LONG == 64
        unsigned long result = old * ((u64) mult);
        result /= div;
        return result;
#endif
}

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

/*
 * 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)

/* Governor Events */
#define CPUFREQ_GOV_START       1
#define CPUFREQ_GOV_STOP        2
#define CPUFREQ_GOV_LIMITS      3
#define CPUFREQ_GOV_POLICY_INIT 4
#define CPUFREQ_GOV_POLICY_EXIT 5

struct cpufreq_governor {
        char    name[CPUFREQ_NAME_LEN];
        int     initialized;
        int     (*governor)     (struct cpufreq_policy *policy,
                                 unsigned int event);
        ssize_t (*show_setspeed)        (struct cpufreq_policy *policy,
                                         char *buf);
        int     (*store_setspeed)       (struct cpufreq_policy *policy,
                                         unsigned int freq);
        unsigned int max_transition_latency; /* HW must be able to switch to
                        next freq faster than this value in nano secs or we
                        will fallback to performance governor */
        struct list_head        governor_list;
        struct module           *owner;
};

/* Pass a target to the cpufreq driver */
int cpufreq_driver_target(struct cpufreq_policy *policy,
                                 unsigned int target_freq,
                                 unsigned int relation);
int __cpufreq_driver_target(struct cpufreq_policy *policy,
                                   unsigned int target_freq,
                                   unsigned int relation);
int cpufreq_register_governor(struct cpufreq_governor *governor);
void cpufreq_unregister_governor(struct cpufreq_governor *governor);

/* CPUFREQ DEFAULT GOVERNOR */
/*
 * Performance governor is fallback governor if any other gov failed to auto
 * load due latency restrictions
 */
#ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE
extern struct cpufreq_governor cpufreq_gov_performance;
#endif
#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_performance)
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_POWERSAVE)
extern struct cpufreq_governor cpufreq_gov_powersave;
#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_powersave)
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE)
extern struct cpufreq_governor cpufreq_gov_userspace;
#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_userspace)
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND)
extern struct cpufreq_governor cpufreq_gov_ondemand;
#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_ondemand)
#elif defined(CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE)
extern struct cpufreq_governor cpufreq_gov_conservative;
#define CPUFREQ_DEFAULT_GOVERNOR        (&cpufreq_gov_conservative)
#endif

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

/* Special Values of .frequency field */
#define CPUFREQ_ENTRY_INVALID   ~0u
#define CPUFREQ_TABLE_END       ~1u
/* Special Values of .flags field */
#define CPUFREQ_BOOST_FREQ      (1 << 0)

struct cpufreq_frequency_table {
        unsigned int    flags;
        unsigned int    driver_data; /* driver specific data, not used by core */
        unsigned int    frequency; /* kHz - doesn't need to be in ascending
                                    * order */
};

#if defined(CONFIG_CPU_FREQ) && defined(CONFIG_PM_OPP)
int dev_pm_opp_init_cpufreq_table(struct device *dev,
                                  struct cpufreq_frequency_table **table);
void dev_pm_opp_free_cpufreq_table(struct device *dev,
                                   struct cpufreq_frequency_table **table);
#else
static inline int dev_pm_opp_init_cpufreq_table(struct device *dev,
                                                struct cpufreq_frequency_table
                                                **table)
{
        return -EINVAL;
}

static inline void dev_pm_opp_free_cpufreq_table(struct device *dev,
                                                 struct cpufreq_frequency_table
                                                 **table)
{
}
#endif

static inline bool cpufreq_next_valid(struct cpufreq_frequency_table **pos)
{
        while ((*pos)->frequency != CPUFREQ_TABLE_END)
                if ((*pos)->frequency != CPUFREQ_ENTRY_INVALID)
                        return true;
                else
                        (*pos)++;
        return false;
}

/*
 * cpufreq_for_each_entry -     iterate over a cpufreq_frequency_table
 * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 * @table:      the cpufreq_frequency_table * to iterate over.
 */

#define cpufreq_for_each_entry(pos, table)      \
        for (pos = table; pos->frequency != CPUFREQ_TABLE_END; pos++)

/*
 * cpufreq_for_each_valid_entry -     iterate over a cpufreq_frequency_table
 *      excluding CPUFREQ_ENTRY_INVALID frequencies.
 * @pos:        the cpufreq_frequency_table * to use as a loop cursor.
 * @table:      the cpufreq_frequency_table * to iterate over.
 */

#define cpufreq_for_each_valid_entry(pos, table)        \
        for (pos = table; cpufreq_next_valid(&pos); pos++)

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_generic_frequency_table_verify(struct cpufreq_policy *policy);

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

ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf);

#ifdef CONFIG_CPU_FREQ
int cpufreq_boost_trigger_state(int state);
int cpufreq_boost_supported(void);
int cpufreq_boost_enabled(void);
#else
static inline int cpufreq_boost_trigger_state(int state)
{
        return 0;
}
static inline int cpufreq_boost_supported(void)
{
        return 0;
}
static inline int cpufreq_boost_enabled(void)
{
        return 0;
}
#endif
/* the following funtion is for cpufreq core use only */
struct cpufreq_frequency_table *cpufreq_frequency_get_table(unsigned int cpu);

/* the following are really really optional */
extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;
extern struct freq_attr *cpufreq_generic_attr[];
int cpufreq_table_validate_and_show(struct cpufreq_policy *policy,
                                      struct cpufreq_frequency_table *table);

unsigned int cpufreq_generic_get(unsigned int cpu);
int cpufreq_generic_init(struct cpufreq_policy *policy,
                struct cpufreq_frequency_table *table,
                unsigned int transition_latency);
#endif /* _LINUX_CPUFREQ_H */