LXR linux/include/linux/devfreq-event.h

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * devfreq-event: a framework to provide raw data and events of devfreq devices
   4 *
   5 * Copyright (C) 2014 Samsung Electronics
   6 * Author: Chanwoo Choi <cw00.choi@samsung.com>
   7 */
   8
   9#ifndef __LINUX_DEVFREQ_EVENT_H__
  10#define __LINUX_DEVFREQ_EVENT_H__
  11
  12#include <linux/device.h>
  13
  14/**
  15 * struct devfreq_event_dev - the devfreq-event device
  16 *
  17 * @node        : Contain the devfreq-event device that have been registered.
  18 * @dev         : the device registered by devfreq-event class. dev.parent is
  19 *                the device using devfreq-event.
  20 * @lock        : a mutex to protect accessing devfreq-event.
  21 * @enable_count: the number of enable function have been called.
  22 * @desc        : the description for devfreq-event device.
  23 *
  24 * This structure contains devfreq-event device information.
  25 */
  26struct devfreq_event_dev {
  27        struct list_head node;
  28
  29        struct device dev;
  30        struct mutex lock;
  31        u32 enable_count;
  32
  33        const struct devfreq_event_desc *desc;
  34};
  35
  36/**
  37 * struct devfreq_event_data - the devfreq-event data
  38 *
  39 * @load_count  : load count of devfreq-event device for the given period.
  40 * @total_count : total count of devfreq-event device for the given period.
  41 *                each count may represent a clock cycle, a time unit
  42 *                (ns/us/...), or anything the device driver wants.
  43 *                Generally, utilization is load_count / total_count.
  44 *
  45 * This structure contains the data of devfreq-event device for polling period.
  46 */
  47struct devfreq_event_data {
  48        unsigned long load_count;
  49        unsigned long total_count;
  50};
  51
  52/**
  53 * struct devfreq_event_ops - the operations of devfreq-event device
  54 *
  55 * @enable      : Enable the devfreq-event device.
  56 * @disable     : Disable the devfreq-event device.
  57 * @reset       : Reset all setting of the devfreq-event device.
  58 * @set_event   : Set the specific event type for the devfreq-event device.
  59 * @get_event   : Get the result of the devfreq-event devie with specific
  60 *                event type.
  61 *
  62 * This structure contains devfreq-event device operations which can be
  63 * implemented by devfreq-event device drivers.
  64 */
  65struct devfreq_event_ops {
  66        /* Optional functions */
  67        int (*enable)(struct devfreq_event_dev *edev);
  68        int (*disable)(struct devfreq_event_dev *edev);
  69        int (*reset)(struct devfreq_event_dev *edev);
  70
  71        /* Mandatory functions */
  72        int (*set_event)(struct devfreq_event_dev *edev);
  73        int (*get_event)(struct devfreq_event_dev *edev,
  74                         struct devfreq_event_data *edata);
  75};
  76
  77/**
  78 * struct devfreq_event_desc - the descriptor of devfreq-event device
  79 *
  80 * @name        : the name of devfreq-event device.
  81 * @event_type  : the type of the event determined and used by driver
  82 * @driver_data : the private data for devfreq-event driver.
  83 * @ops         : the operation to control devfreq-event device.
  84 *
  85 * Each devfreq-event device is described with a this structure.
  86 * This structure contains the various data for devfreq-event device.
  87 * The event_type describes what is going to be counted in the register.
  88 * It might choose to count e.g. read requests, write data in bytes, etc.
  89 * The full supported list of types is present in specyfic header in:
  90 * include/dt-bindings/pmu/.
  91 */
  92struct devfreq_event_desc {
  93        const char *name;
  94        u32 event_type;
  95        void *driver_data;
  96
  97        const struct devfreq_event_ops *ops;
  98};
  99
 100#if defined(CONFIG_PM_DEVFREQ_EVENT)
 101extern int devfreq_event_enable_edev(struct devfreq_event_dev *edev);
 102extern int devfreq_event_disable_edev(struct devfreq_event_dev *edev);
 103extern bool devfreq_event_is_enabled(struct devfreq_event_dev *edev);
 104extern int devfreq_event_set_event(struct devfreq_event_dev *edev);
 105extern int devfreq_event_get_event(struct devfreq_event_dev *edev,
 106                                struct devfreq_event_data *edata);
 107extern int devfreq_event_reset_event(struct devfreq_event_dev *edev);
 108extern struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(
 109                                struct device *dev, int index);
 110extern int devfreq_event_get_edev_count(struct device *dev);
 111extern struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
 112                                struct devfreq_event_desc *desc);
 113extern int devfreq_event_remove_edev(struct devfreq_event_dev *edev);
 114extern struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
 115                                struct devfreq_event_desc *desc);
 116extern void devm_devfreq_event_remove_edev(struct device *dev,
 117                                struct devfreq_event_dev *edev);
 118static inline void *devfreq_event_get_drvdata(struct devfreq_event_dev *edev)
 119{
 120        return edev->desc->driver_data;
 121}
 122#else
 123static inline int devfreq_event_enable_edev(struct devfreq_event_dev *edev)
 124{
 125        return -EINVAL;
 126}
 127
 128static inline int devfreq_event_disable_edev(struct devfreq_event_dev *edev)
 129{
 130        return -EINVAL;
 131}
 132
 133static inline bool devfreq_event_is_enabled(struct devfreq_event_dev *edev)
 134{
 135        return false;
 136}
 137
 138static inline int devfreq_event_set_event(struct devfreq_event_dev *edev)
 139{
 140        return -EINVAL;
 141}
 142
 143static inline int devfreq_event_get_event(struct devfreq_event_dev *edev,
 144                                        struct devfreq_event_data *edata)
 145{
 146        return -EINVAL;
 147}
 148
 149static inline int devfreq_event_reset_event(struct devfreq_event_dev *edev)
 150{
 151        return -EINVAL;
 152}
 153
 154static inline struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(
 155                                        struct device *dev, int index)
 156{
 157        return ERR_PTR(-EINVAL);
 158}
 159
 160static inline int devfreq_event_get_edev_count(struct device *dev)
 161{
 162        return -EINVAL;
 163}
 164
 165static inline struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
 166                                        struct devfreq_event_desc *desc)
 167{
 168        return ERR_PTR(-EINVAL);
 169}
 170
 171static inline int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
 172{
 173        return -EINVAL;
 174}
 175
 176static inline struct devfreq_event_dev *devm_devfreq_event_add_edev(
 177                                        struct device *dev,
 178                                        struct devfreq_event_desc *desc)
 179{
 180        return ERR_PTR(-EINVAL);
 181}
 182
 183static inline void devm_devfreq_event_remove_edev(struct device *dev,
 184                                        struct devfreq_event_dev *edev)
 185{
 186}
 187
 188static inline void *devfreq_event_get_drvdata(struct devfreq_event_dev *edev)
 189{
 190        return NULL;
 191}
 192#endif /* CONFIG_PM_DEVFREQ_EVENT */
 193
 194#endif /* __LINUX_DEVFREQ_EVENT_H__ */
 195