wakeup_stats.c

  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 sysfs_emit(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);
 37wakeup_attr(relax_count);
 38
 39static ssize_t active_time_ms_show(struct device *dev,
 40				   struct device_attribute *attr, char *buf)
 41{
 42	struct wakeup_source *ws = dev_get_drvdata(dev);
 43	ktime_t active_time =
 44		ws->active ? ktime_sub(ktime_get(), ws->last_time) : 0;
 45
 46	return sysfs_emit(buf, "%lld\n", ktime_to_ms(active_time));
 47}
 48static DEVICE_ATTR_RO(active_time_ms);
 49
 50static ssize_t total_time_ms_show(struct device *dev,
 51				  struct device_attribute *attr, char *buf)
 52{
 53	struct wakeup_source *ws = dev_get_drvdata(dev);
 54	ktime_t active_time;
 55	ktime_t total_time = ws->total_time;
 56
 57	if (ws->active) {
 58		active_time = ktime_sub(ktime_get(), ws->last_time);
 59		total_time = ktime_add(total_time, active_time);
 60	}
 61
 62	return sysfs_emit(buf, "%lld\n", ktime_to_ms(total_time));
 63}
 64static DEVICE_ATTR_RO(total_time_ms);
 65
 66static ssize_t max_time_ms_show(struct device *dev,
 67				struct device_attribute *attr, char *buf)
 68{
 69	struct wakeup_source *ws = dev_get_drvdata(dev);
 70	ktime_t active_time;
 71	ktime_t max_time = ws->max_time;
 72
 73	if (ws->active) {
 74		active_time = ktime_sub(ktime_get(), ws->last_time);
 75		if (active_time > max_time)
 76			max_time = active_time;
 77	}
 78
 79	return sysfs_emit(buf, "%lld\n", ktime_to_ms(max_time));
 80}
 81static DEVICE_ATTR_RO(max_time_ms);
 82
 83static ssize_t last_change_ms_show(struct device *dev,
 84				   struct device_attribute *attr, char *buf)
 85{
 86	struct wakeup_source *ws = dev_get_drvdata(dev);
 87
 88	return sysfs_emit(buf, "%lld\n", ktime_to_ms(ws->last_time));
 89}
 90static DEVICE_ATTR_RO(last_change_ms);
 91
 92static ssize_t name_show(struct device *dev, struct device_attribute *attr,
 93			 char *buf)
 94{
 95	struct wakeup_source *ws = dev_get_drvdata(dev);
 96
 97	return sysfs_emit(buf, "%s\n", ws->name);
 98}
 99static DEVICE_ATTR_RO(name);
100
101static ssize_t prevent_suspend_time_ms_show(struct device *dev,
102					    struct device_attribute *attr,
103					    char *buf)
104{
105	struct wakeup_source *ws = dev_get_drvdata(dev);
106	ktime_t prevent_sleep_time = ws->prevent_sleep_time;
107
108	if (ws->active && ws->autosleep_enabled) {
109		prevent_sleep_time = ktime_add(prevent_sleep_time,
110			ktime_sub(ktime_get(), ws->start_prevent_time));
111	}
112
113	return sysfs_emit(buf, "%lld\n", ktime_to_ms(prevent_sleep_time));
114}
115static DEVICE_ATTR_RO(prevent_suspend_time_ms);
116
117static struct attribute *wakeup_source_attrs[] = {
118	&dev_attr_name.attr,
119	&dev_attr_active_count.attr,
120	&dev_attr_event_count.attr,
121	&dev_attr_wakeup_count.attr,
122	&dev_attr_expire_count.attr,
123	&dev_attr_relax_count.attr,
124	&dev_attr_active_time_ms.attr,
125	&dev_attr_total_time_ms.attr,
126	&dev_attr_max_time_ms.attr,
127	&dev_attr_last_change_ms.attr,
128	&dev_attr_prevent_suspend_time_ms.attr,
129	NULL,
130};
131ATTRIBUTE_GROUPS(wakeup_source);
132
133static void device_create_release(struct device *dev)
134{
135	kfree(dev);
136}
137
138static struct device *wakeup_source_device_create(struct device *parent,
139						  struct wakeup_source *ws)
140{
141	struct device *dev = NULL;
142	int retval;
143
144	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
145	if (!dev) {
146		retval = -ENOMEM;
147		goto error;
148	}
149
150	device_initialize(dev);
151	dev->devt = MKDEV(0, 0);
152	dev->class = wakeup_class;
153	dev->parent = parent;
154	dev->groups = wakeup_source_groups;
155	dev->release = device_create_release;
156	dev_set_drvdata(dev, ws);
157	device_set_pm_not_required(dev);
158
159	retval = dev_set_name(dev, "wakeup%d", ws->id);
160	if (retval)
161		goto error;
162
163	retval = device_add(dev);
164	if (retval)
165		goto error;
166
167	return dev;
168
169error:
170	put_device(dev);
171	return ERR_PTR(retval);
172}
173
174/**
175 * wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs.
176 * @parent: Device given wakeup source is associated with (or NULL if virtual).
177 * @ws: Wakeup source to be added in sysfs.
178 */
179int wakeup_source_sysfs_add(struct device *parent, struct wakeup_source *ws)
180{
181	struct device *dev;
182
183	dev = wakeup_source_device_create(parent, ws);
184	if (IS_ERR(dev))
185		return PTR_ERR(dev);
186	ws->dev = dev;
187
188	return 0;
189}
190
191/**
192 * pm_wakeup_source_sysfs_add - Add wakeup_source attributes to sysfs
193 * for a device if they're missing.
194 * @parent: Device given wakeup source is associated with
195 */
196int pm_wakeup_source_sysfs_add(struct device *parent)
197{
198	if (!parent->power.wakeup || parent->power.wakeup->dev)
199		return 0;
200
201	return wakeup_source_sysfs_add(parent, parent->power.wakeup);
202}
203
204/**
205 * wakeup_source_sysfs_remove - Remove wakeup_source attributes from sysfs.
206 * @ws: Wakeup source to be removed from sysfs.
207 */
208void wakeup_source_sysfs_remove(struct wakeup_source *ws)
209{
210	device_unregister(ws->dev);
211}
212
213static int __init wakeup_sources_sysfs_init(void)
214{
215	wakeup_class = class_create("wakeup");
216
217	return PTR_ERR_OR_ZERO(wakeup_class);
218}
219postcore_initcall(wakeup_sources_sysfs_init);