include/linux/thermal.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  thermal.h  ($Revision: 0 $)
 *
 *  Copyright (C) 2008  Intel Corp
 *  Copyright (C) 2008  Zhang Rui <rui.zhang@intel.com>
 *  Copyright (C) 2008  Sujith Thomas <sujith.thomas@intel.com>
 */

#ifndef __THERMAL_H__
#define __THERMAL_H__

#include <linux/of.h>
#include <linux/idr.h>
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/workqueue.h>
#include <uapi/linux/thermal.h>

#define THERMAL_TRIPS_NONE (-1)
#define THERMAL_MAX_TRIPS 12

/* invalid cooling state */
#define THERMAL_CSTATE_INVALID (-1UL)

/* No upper/lower limit requirement */
#define THERMAL_NO_LIMIT ((u32)~0)

/* Default weight of a bound cooling device */
#define THERMAL_WEIGHT_DEFAULT 0

/* use value, which < 0K, to indicate an invalid/uninitialized temperature */
#define THERMAL_TEMP_INVALID (-274000)

struct thermal_zone_device;
struct thermal_cooling_device;
struct thermal_instance;
struct thermal_attr;

enum thermal_trend {
    THERMAL_TREND_STABLE,     /* temperature is stable */
    THERMAL_TREND_RAISING,    /* temperature is raising */
    THERMAL_TREND_DROPPING,   /* temperature is dropping */
    THERMAL_TREND_RAISE_FULL, /* apply highest cooling action */
    THERMAL_TREND_DROP_FULL,  /* apply lowest cooling action */
};

/* Thermal notification reason */
enum thermal_notify_event {
    THERMAL_EVENT_UNSPECIFIED,               /* Unspecified event */
    THERMAL_EVENT_TEMP_SAMPLE,               /* New Temperature sample */
    THERMAL_TRIP_VIOLATED,                   /* TRIP Point violation */
    THERMAL_TRIP_CHANGED,                    /* TRIP Point temperature changed */
    THERMAL_DEVICE_DOWN,                     /* Thermal device is down */
    THERMAL_DEVICE_UP,                       /* Thermal device is up after a down event */
    THERMAL_DEVICE_POWER_CAPABILITY_CHANGED, /* power capability changed */
    THERMAL_TABLE_CHANGED,                   /* Thermal table(s) changed */
    THERMAL_EVENT_KEEP_ALIVE,                /* Request for user space handler to respond */
};

struct thermal_zone_device_ops {
    int (*bind)(struct thermal_zone_device *, struct thermal_cooling_device *);
    int (*unbind)(struct thermal_zone_device *, struct thermal_cooling_device *);
    int (*get_temp)(struct thermal_zone_device *, int *);
    int (*set_trips)(struct thermal_zone_device *, int, int);
    int (*change_mode)(struct thermal_zone_device *, enum thermal_device_mode);
    int (*get_trip_type)(struct thermal_zone_device *, int, enum thermal_trip_type *);
    int (*get_trip_temp)(struct thermal_zone_device *, int, int *);
    int (*set_trip_temp)(struct thermal_zone_device *, int, int);
    int (*get_trip_hyst)(struct thermal_zone_device *, int, int *);
    int (*set_trip_hyst)(struct thermal_zone_device *, int, int);
    int (*get_crit_temp)(struct thermal_zone_device *, int *);
    int (*set_emul_temp)(struct thermal_zone_device *, int);
    int (*get_trend)(struct thermal_zone_device *, int, enum thermal_trend *);
    int (*notify)(struct thermal_zone_device *, int, enum thermal_trip_type);
};

struct thermal_cooling_device_ops {
    int (*get_max_state)(struct thermal_cooling_device *, unsigned long *);
    int (*get_cur_state)(struct thermal_cooling_device *, unsigned long *);
    int (*set_cur_state)(struct thermal_cooling_device *, unsigned long);
    int (*get_requested_power)(struct thermal_cooling_device *, u32 *);
    int (*state2power)(struct thermal_cooling_device *, unsigned long, u32 *);
    int (*power2state)(struct thermal_cooling_device *, u32, unsigned long *);
};

struct thermal_cooling_device {
    int id;
    char *type;
    struct device device;
    struct device_node *np;
    void *devdata;
    void *stats;
    const struct thermal_cooling_device_ops *ops;
    bool updated;      /* true if the cooling device does not need update */
    struct mutex lock; /* protect thermal_instances list */
    struct list_head thermal_instances;
    struct list_head node;
};

/**
 * struct thermal_zone_device - structure for a thermal zone
 * @id:        unique id number for each thermal zone
 * @type:    the thermal zone device type
 * @device:    &struct device for this thermal zone
 * @trip_temp_attrs:    attributes for trip points for sysfs: trip temperature
 * @trip_type_attrs:    attributes for trip points for sysfs: trip type
 * @trip_hyst_attrs:    attributes for trip points for sysfs: trip hysteresis
 * @mode:        current mode of this thermal zone
 * @devdata:    private pointer for device private data
 * @trips:    number of trip points the thermal zone supports
 * @trips_disabled;    bitmap for disabled trips
 * @passive_delay:    number of milliseconds to wait between polls when
 *            performing passive cooling.
 * @polling_delay:    number of milliseconds to wait between polls when
 *            checking whether trip points have been crossed (0 for
 *            interrupt driven systems)
 * @temperature:    current temperature.  This is only for core code,
 *            drivers should use thermal_zone_get_temp() to get the
 *            current temperature
 * @last_temperature:    previous temperature read
 * @emul_temperature:    emulated temperature when using CONFIG_THERMAL_EMULATION
 * @passive:        1 if you've crossed a passive trip point, 0 otherwise.
 * @prev_low_trip:    the low current temperature if you've crossed a passive
            trip point.
 * @prev_high_trip:    the above current temperature if you've crossed a
            passive trip point.
 * @forced_passive:    If > 0, temperature at which to switch on all ACPI
 *            processor cooling devices.  Currently only used by the
 *            step-wise governor.
 * @need_update:    if equals 1, thermal_zone_device_update needs to be invoked.
 * @ops:    operations this &thermal_zone_device supports
 * @tzp:    thermal zone parameters
 * @governor:    pointer to the governor for this thermal zone
 * @governor_data:    private pointer for governor data
 * @thermal_instances:    list of &struct thermal_instance of this thermal zone
 * @ida:    &struct ida to generate unique id for this zone's cooling
 *        devices
 * @lock:    lock to protect thermal_instances list
 * @node:    node in thermal_tz_list (in thermal_core.c)
 * @poll_queue:    delayed work for polling
 * @notify_event: Last notification event
 */
struct thermal_zone_device {
    int id;
    char type[THERMAL_NAME_LENGTH];
    struct device device;
    struct attribute_group trips_attribute_group;
    struct thermal_attr *trip_temp_attrs;
    struct thermal_attr *trip_type_attrs;
    struct thermal_attr *trip_hyst_attrs;
    enum thermal_device_mode mode;
    void *devdata;
    int trips;
    unsigned long trips_disabled; /* bitmap for disabled trips */
    int passive_delay;
    int polling_delay;
    int temperature;
    int last_temperature;
    int emul_temperature;
    int passive;
    int prev_low_trip;
    int prev_high_trip;
    unsigned int forced_passive;
    atomic_t need_update;
    struct thermal_zone_device_ops *ops;
    struct thermal_zone_params *tzp;
    struct thermal_governor *governor;
    void *governor_data;
    struct list_head thermal_instances;
    struct ida ida;
    struct mutex lock;
    struct list_head node;
    struct delayed_work poll_queue;
    enum thermal_notify_event notify_event;
};

/**
 * struct thermal_governor - structure that holds thermal governor information
 * @name:    name of the governor
 * @bind_to_tz: callback called when binding to a thermal zone.  If it
 *        returns 0, the governor is bound to the thermal zone,
 *        otherwise it fails.
 * @unbind_from_tz:    callback called when a governor is unbound from a
 *            thermal zone.
 * @throttle:    callback called for every trip point even if temperature is
 *        below the trip point temperature
 * @governor_list:    node in thermal_governor_list (in thermal_core.c)
 */
struct thermal_governor {
    char name[THERMAL_NAME_LENGTH];
    int (*bind_to_tz)(struct thermal_zone_device *tz);
    void (*unbind_from_tz)(struct thermal_zone_device *tz);
    int (*throttle)(struct thermal_zone_device *tz, int trip);
    struct list_head governor_list;
};

/* Structure that holds binding parameters for a zone */
struct thermal_bind_params {
    struct thermal_cooling_device *cdev;

    /*
     * This is a measure of 'how effectively these devices can
     * cool 'this' thermal zone. It shall be determined by
     * platform characterization. This value is relative to the
     * rest of the weights so a cooling device whose weight is
     * double that of another cooling device is twice as
     * effective. See Documentation/driver-api/thermal/sysfs-api.rst for more
     * information.
     */
    int weight;

    /*
     * This is a bit mask that gives the binding relation between this
     * thermal zone and cdev, for a particular trip point.
     * See Documentation/driver-api/thermal/sysfs-api.rst for more information.
     */
    int trip_mask;

    /*
     * This is an array of cooling state limits. Must have exactly
     * 2 * thermal_zone.number_of_trip_points. It is an array consisting
     * of tuples <lower-state upper-state> of state limits. Each trip
     * will be associated with one state limit tuple when binding.
     * A NULL pointer means <THERMAL_NO_LIMITS THERMAL_NO_LIMITS>
     * on all trips.
     */
    unsigned long *binding_limits;
    int (*match)(struct thermal_zone_device *tz, struct thermal_cooling_device *cdev);
};

/* Structure to define Thermal Zone parameters */
struct thermal_zone_params {
    char governor_name[THERMAL_NAME_LENGTH];

    /*
     * a boolean to indicate if the thermal to hwmon sysfs interface
     * is required. when no_hwmon == false, a hwmon sysfs interface
     * will be created. when no_hwmon == true, nothing will be done
     */
    bool no_hwmon;

    int num_tbps; /* Number of tbp entries */
    struct thermal_bind_params *tbp;

    /*
     * Sustainable power (heat) that this thermal zone can dissipate in
     * mW
     */
    u32 sustainable_power;

    /*
     * Proportional parameter of the PID controller when
     * overshooting (i.e., when temperature is below the target)
     */
    s32 k_po;

    /*
     * Proportional parameter of the PID controller when
     * undershooting
     */
    s32 k_pu;

    /* Integral parameter of the PID controller */
    s32 k_i;

    /* Derivative parameter of the PID controller */
    s32 k_d;

    /* threshold below which the error is no longer accumulated */
    s32 integral_cutoff;

    /*
     * @slope:    slope of a linear temperature adjustment curve.
     *         Used by thermal zone drivers.
     */
    int slope;
    /*
     * @offset:    offset of a linear temperature adjustment curve.
     *         Used by thermal zone drivers (default 0).
     */
    int offset;
};

/**
 * struct thermal_zone_of_device_ops - scallbacks for handling DT based zones
 *
 * Mandatory:
 * @get_temp: a pointer to a function that reads the sensor temperature.
 *
 * Optional:
 * @get_trend: a pointer to a function that reads the sensor temperature trend.
 * @set_trips: a pointer to a function that sets a temperature window. When
 *           this window is left the driver must inform the thermal core via
 *           thermal_zone_device_update.
 * @set_emul_temp: a pointer to a function that sets sensor emulated
 *           temperature.
 * @set_trip_temp: a pointer to a function that sets the trip temperature on
 *           hardware.
 */
struct thermal_zone_of_device_ops {
    int (*get_temp)(void *, int *);
    int (*get_trend)(void *, int, enum thermal_trend *);
    int (*set_trips)(void *, int, int);
    int (*set_emul_temp)(void *, int);
    int (*set_trip_temp)(void *, int, int);
};

/* Function declarations */
#ifdef CONFIG_THERMAL_OF
int thermal_zone_of_get_sensor_id(struct device_node *tz_np, struct device_node *sensor_np, u32 *id);
struct thermal_zone_device *thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
                                                            const struct thermal_zone_of_device_ops *ops);
void thermal_zone_of_sensor_unregister(struct device *dev, struct thermal_zone_device *tz);
struct thermal_zone_device *devm_thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
                                                                 const struct thermal_zone_of_device_ops *ops);
void devm_thermal_zone_of_sensor_unregister(struct device *dev, struct thermal_zone_device *tz);
#else

static inline int thermal_zone_of_get_sensor_id(struct device_node *tz_np, struct device_node *sensor_np, u32 *id)
{
    return -ENOENT;
}
static inline struct thermal_zone_device *thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
                                                                          const struct thermal_zone_of_device_ops *ops)
{
    return ERR_PTR(-ENODEV);
}

static inline void thermal_zone_of_sensor_unregister(struct device *dev, struct thermal_zone_device *tz)
{
}

static inline struct thermal_zone_device *
devm_thermal_zone_of_sensor_register(struct device *dev, int id, void *data,
                                     const struct thermal_zone_of_device_ops *ops)
{
    return ERR_PTR(-ENODEV);
}

static inline void devm_thermal_zone_of_sensor_unregister(struct device *dev, struct thermal_zone_device *tz)
{
}

#endif

#ifdef CONFIG_THERMAL
struct thermal_zone_device *thermal_zone_device_register(const char *, int, int, void *,
                                                         struct thermal_zone_device_ops *, struct thermal_zone_params *,
                                                         int, int);
void thermal_zone_device_unregister(struct thermal_zone_device *);

int thermal_zone_bind_cooling_device(struct thermal_zone_device *, int, struct thermal_cooling_device *, unsigned long,
                                     unsigned long, unsigned int);
int thermal_zone_unbind_cooling_device(struct thermal_zone_device *, int, struct thermal_cooling_device *);
void thermal_zone_device_update(struct thermal_zone_device *, enum thermal_notify_event);

struct thermal_cooling_device *thermal_cooling_device_register(const char *, void *,
                                                               const struct thermal_cooling_device_ops *);
struct thermal_cooling_device *thermal_of_cooling_device_register(struct device_node *np, const char *, void *,
                                                                  const struct thermal_cooling_device_ops *);
struct thermal_cooling_device *devm_thermal_of_cooling_device_register(struct device *dev, struct device_node *np,
                                                                       char *type, void *devdata,
                                                                       const struct thermal_cooling_device_ops *ops);
void thermal_cooling_device_unregister(struct thermal_cooling_device *);
struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name);
int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp);
int thermal_zone_get_slope(struct thermal_zone_device *tz);
int thermal_zone_get_offset(struct thermal_zone_device *tz);

void thermal_cdev_update(struct thermal_cooling_device *);
void thermal_notify_framework(struct thermal_zone_device *, int);
int thermal_zone_device_enable(struct thermal_zone_device *tz);
int thermal_zone_device_disable(struct thermal_zone_device *tz);
int thermal_zone_device_is_enabled(struct thermal_zone_device *tz);
#else
static inline struct thermal_zone_device *
thermal_zone_device_register(const char *type, int trips, int mask, void *devdata, struct thermal_zone_device_ops *ops,
                             struct thermal_zone_params *tzp, int passive_delay, int polling_delay)
{
    return ERR_PTR(-ENODEV);
}
static inline void thermal_zone_device_unregister(struct thermal_zone_device *tz)
{
}
static inline struct thermal_cooling_device *
thermal_cooling_device_register(const char *type, void *devdata, const struct thermal_cooling_device_ops *ops)
{
    return ERR_PTR(-ENODEV);
}
static inline struct thermal_cooling_device *
thermal_of_cooling_device_register(struct device_node *np, const char *type, void *devdata,
                                   const struct thermal_cooling_device_ops *ops)
{
    return ERR_PTR(-ENODEV);
}
static inline struct thermal_cooling_device *
devm_thermal_of_cooling_device_register(struct device *dev, struct device_node *np, char *type, void *devdata,
                                        const struct thermal_cooling_device_ops *ops)
{
    return ERR_PTR(-ENODEV);
}
static inline void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
{
}
static inline struct thermal_zone_device *thermal_zone_get_zone_by_name(const char *name)
{
    return ERR_PTR(-ENODEV);
}
static inline int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
{
    return -ENODEV;
}
static inline int thermal_zone_get_slope(struct thermal_zone_device *tz)
{
    return -ENODEV;
}
static inline int thermal_zone_get_offset(struct thermal_zone_device *tz)
{
    return -ENODEV;
}

static inline void thermal_cdev_update(struct thermal_cooling_device *cdev)
{
}
static inline void thermal_notify_framework(struct thermal_zone_device *tz, int trip)
{
}

static inline int thermal_zone_device_enable(struct thermal_zone_device *tz)
{
    return -ENODEV;
}

static inline int thermal_zone_device_disable(struct thermal_zone_device *tz)
{
    return -ENODEV;
}

static inline int thermal_zone_device_is_enabled(struct thermal_zone_device *tz)
{
    return -ENODEV;
}
#endif /* CONFIG_THERMAL */

#endif /* __THERMAL_H__ */