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  */
  26 struct 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  */
  47 struct 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  */
  65 struct 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  */
  92 struct 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)
 101 extern int devfreq_event_enable_edev(struct devfreq_event_dev *edev);
 102 extern int devfreq_event_disable_edev(struct devfreq_event_dev *edev);
 103 extern bool devfreq_event_is_enabled(struct devfreq_event_dev *edev);
 104 extern int devfreq_event_set_event(struct devfreq_event_dev *edev);
 105 extern int devfreq_event_get_event(struct devfreq_event_dev *edev,
 106                                 struct devfreq_event_data *edata);
 107 extern int devfreq_event_reset_event(struct devfreq_event_dev *edev);
 108 extern struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(
 109                                 struct device *dev, int index);
 110 extern int devfreq_event_get_edev_count(struct device *dev);
 111 extern struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
 112                                 struct devfreq_event_desc *desc);
 113 extern int devfreq_event_remove_edev(struct devfreq_event_dev *edev);
 114 extern struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
 115                                 struct devfreq_event_desc *desc);
 116 extern void devm_devfreq_event_remove_edev(struct device *dev,
 117                                 struct devfreq_event_dev *edev);
 118 static inline void *devfreq_event_get_drvdata(struct devfreq_event_dev *edev)
 119 {
 120         return edev->desc->driver_data;
 121 }
 122 #else
 123 static inline int devfreq_event_enable_edev(struct devfreq_event_dev *edev)
 124 {
 125         return -EINVAL;
 126 }
 127
 128 static inline int devfreq_event_disable_edev(struct devfreq_event_dev *edev)
 129 {
 130         return -EINVAL;
 131 }
 132
 133 static inline bool devfreq_event_is_enabled(struct devfreq_event_dev *edev)
 134 {
 135         return false;
 136 }
 137
 138 static inline int devfreq_event_set_event(struct devfreq_event_dev *edev)
 139 {
 140         return -EINVAL;
 141 }
 142
 143 static inline int devfreq_event_get_event(struct devfreq_event_dev *edev,
 144                                         struct devfreq_event_data *edata)
 145 {
 146         return -EINVAL;
 147 }
 148
 149 static inline int devfreq_event_reset_event(struct devfreq_event_dev *edev)
 150 {
 151         return -EINVAL;
 152 }
 153
 154 static 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
 160 static inline int devfreq_event_get_edev_count(struct device *dev)
 161 {
 162         return -EINVAL;
 163 }
 164
 165 static 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
 171 static inline int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
 172 {
 173         return -EINVAL;
 174 }
 175
 176 static 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
 183 static inline void devm_devfreq_event_remove_edev(struct device *dev,
 184                                         struct devfreq_event_dev *edev)
 185 {
 186 }
 187
 188 static 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__ */