linux/drivers/base/power/wakeup_stats.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Wakeup statistics in sysfs
   4 *
   5 * Copyright (c) 2019 Linux Foundation
   6 * Copyright (c) 2019 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
   7 * Copyright (c) 2019 Google Inc.
   8 */
   9
  10#include <linux/device.h>
  11#include <linux/idr.h>
  12#include <linux/init.h>
  13#include <linux/kdev_t.h>
  14#include <linux/kernel.h>
  15#include <linux/kobject.h>
  16#include <linux/slab.h>
  17#include <linux/timekeeping.h>
  18
  19#include "power.h"
  20
  21static struct class *wakeup_class;
  22
  23#define wakeup_attr(_name)                                              \
  24static ssize_t _name##_show(struct device *dev,                         \
  25                            struct device_attribute *attr, char *buf)   \
  26{                                                                       \
  27        struct wakeup_source *ws = dev_get_drvdata(dev);                \
  28                                                                        \
  29        return sprintf(buf, "%lu\n", ws->_name);                        \
  30}                                                                       \
  31static DEVICE_ATTR_RO(_name)
  32
  33wakeup_attr(active_count);
  34wakeup_attr(event_count);
  35wakeup_attr(wakeup_count);
  36wakeup_attr(expire_count);
  37
  38static ssize_t active_time_ms_show(struct device *dev,
  39                                   struct device_attribute *attr, char *buf)
  40{
  41        struct wakeup_source *ws = dev_get_drvdata(dev);
  42        ktime_t active_time =
  43                ws->active ? ktime_sub(ktime_get(), ws->last_time) : 0;
  44
  45        return sprintf(buf, "%lld\n", ktime_to_ms(active_time));
  46}
  47static DEVICE_ATTR_RO(active_time_ms);
  48
  49static ssize_t total_time_ms_show(struct device *dev,
  50                                  struct device_attribute *attr, char *buf)
  51{
  52        struct wakeup_source *ws = dev_get_drvdata(dev);
  53        ktime_t active_time;
  54        ktime_t total_time = ws->total_time;
  55
  56        if (ws->active) {
  57                active_time = ktime_sub(ktime_get(), ws->last_time);
  58                total_time = ktime_add(total_time, active_time);
  59        }
  60        return sprintf(buf, "%lld\n", ktime_to_ms(total_time));
  61}
  62static DEVICE_ATTR_RO(total_time_ms);
  63
  64static ssize_t max_time_ms_show(struct device *dev,
  65                                struct device_attribute *attr, char *buf)
  66{
  67        struct wakeup_source *ws = dev_get_drvdata(dev);
  68        ktime_t active_time;
  69        ktime_t max_time = ws->max_time;
  70
  71        if (ws->active) {
  72                active_time = ktime_sub(ktime_get(), ws->last_time);
  73                if (active_time > max_time)
  74                        max_time = active_time;
  75        }
  76        return sprintf(buf, "%lld\n", ktime_to_ms(max_time));
  77}
  78static DEVICE_ATTR_RO(max_time_ms);
  79
  80static ssize_t last_change_ms_show(struct device *dev,
  81                                   struct device_attribute *attr, char *buf)
  82{
  83        struct wakeup_source *ws = dev_get_drvdata(dev);
  84
  85        return sprintf(buf, "%lld\n", ktime_to_ms(ws->last_time));
  86}
  87static DEVICE_ATTR_RO(last_change_ms);
  88
  89static ssize_t name_show(struct device *dev, struct device_attribute *attr,
  90                         char *buf)
  91{
  92        struct wakeup_source *ws = dev_get_drvdata(dev);
  93
  94        return sprintf(buf, "%s\n", ws->name);
  95}
  96static DEVICE_ATTR_RO(name);
  97
  98static ssize_t prevent_suspend_time_ms_show(struct device *dev,
  99                                            struct device_attribute *attr,
 100                                            char *buf)
 101{
 102        struct wakeup_source *ws = dev_get_drvdata(dev);
 103        ktime_t prevent_sleep_time = ws->prevent_sleep_time;
 104
 105        if (ws->active && ws->autosleep_enabled) {
 106                prevent_sleep_time = ktime_add(prevent_sleep_time,
 107                        ktime_sub(ktime_get(), ws->start_prevent_time));
 108        }
 109        return sprintf(buf, "%lld\n", ktime_to_ms(prevent_sleep_time));
 110}
 111static DEVICE_ATTR_RO(prevent_suspend_time_ms);
 112
 113static struct attribute *wakeup_source_attrs[] = {
 114        &dev_attr_name.attr,
 115        &dev_attr_active_count.attr,
 116        &dev_attr_event_count.attr,
 117        &dev_attr_wakeup_count.attr,
 118        &dev_attr_expire_count.attr,
 119        &dev_attr_active_time_ms.attr,
 120        &dev_attr_total_time_ms.attr,
 121        &dev_attr_max_time_ms.attr,
 122        &dev_attr_last_change_ms.attr,
 123        &dev_attr_prevent_suspend_time_ms.attr,
 124        NULL,
 125};
 126ATTRIBUTE_GROUPS(wakeup_source);
 127
 128static void device_create_release(struct device *dev)
 129{
 130        kfree(dev);
 131}
 132
 133static struct device *wakeup_source_device_create(struct device *parent,
 134                                                  struct wakeup_source *ws)
 135{
 136        struct device *dev = NULL;
 137        int retval = -ENODEV;
 138
 139        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 140        if (!dev) {
 141                retval = -ENOMEM;
 142                goto error;
 143        }
 144
 145        device_initialize(dev);
 146        dev->devt = MKDEV(0, 0);
 147        dev->class = wakeup_class;
 148        dev->parent = parent;
 149        dev->groups = wakeup_source_groups;
 150        dev->release = device_create_release;
 151        dev_set_drvdata(dev, ws);
 152        device_set_pm_not_required(dev);
 153
 154        retval = kobject_set_name(&dev->kobj, "wakeup%d", ws->id);
 155        if (retval)
 156                goto error;
 157
 158        retval = device_add(dev);
 159        if (retval)
 160                goto error;
 161
 162        return dev;
 163
 164error:
 165        put_device(dev);
 166        return ERR_PTR(retval);
 167}
 168
 169/**
 170 * wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs.
 171 * @parent: Device given wakeup source is associated with (or NULL if virtual).
 172 * @ws: Wakeup source to be added in sysfs.
 173 */
 174int wakeup_source_sysfs_add(struct device *parent, struct wakeup_source *ws)
 175{
 176        struct device *dev;
 177
 178        dev = wakeup_source_device_create(parent, ws);
 179        if (IS_ERR(dev))
 180                return PTR_ERR(dev);
 181        ws->dev = dev;
 182
 183        return 0;
 184}
 185
 186/**
 187 * pm_wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs
 188 * for a device if they're missing.
 189 * @parent: Device given wakeup source is associated with
 190 */
 191int pm_wakeup_source_sysfs_add(struct device *parent)
 192{
 193        if (!parent->power.wakeup || parent->power.wakeup->dev)
 194                return 0;
 195
 196        return wakeup_source_sysfs_add(parent, parent->power.wakeup);
 197}
 198
 199/**
 200 * wakeup_source_sysfs_remove - Remove wakeup_source attributes from sysfs.
 201 * @ws: Wakeup source to be removed from sysfs.
 202 */
 203void wakeup_source_sysfs_remove(struct wakeup_source *ws)
 204{
 205        device_unregister(ws->dev);
 206}
 207
 208static int __init wakeup_sources_sysfs_init(void)
 209{
 210        wakeup_class = class_create(THIS_MODULE, "wakeup");
 211
 212        return PTR_ERR_OR_ZERO(wakeup_class);
 213}
 214postcore_initcall(wakeup_sources_sysfs_init);
 215