include/linux/devfreq-event.h

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